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Sample records for acoustic background installed

  1. Cosmic Microwave Background Acoustic Peak Locations

    CERN Document Server

    Pan, Zhen; Mulroe, Brigid; Narimani, Ali

    2016-01-01

    The Planck collaboration has measured the temperature and polarization of the cosmic microwave background well enough to determine the locations of eight peaks in the temperature (TT) power spectrum, five peaks in the polarization (EE) power spectrum and twelve extrema in the cross (TE) power spectrum. The relative locations of these extrema give a striking, and beautiful, demonstration of what we expect from acoustic oscillations in the plasma; e.g., that EE peaks fall half way between TT peaks. We expect this because the temperature map is predominantly sourced by temperature variations in the last scattering surface, while the polarization map is predominantly sourced by gradients in the velocity field, and the harmonic oscillations have temperature and velocity 90 degrees out of phase. However, there are large differences in expectations for extrema locations from simple analytic models vs. numerical calculations. Here we quantitatively explore the origin of these differences in gravitational potential tr...

  2. Cosmic microwave background acoustic peak locations

    Science.gov (United States)

    Pan, Z.; Knox, L.; Mulroe, B.; Narimani, A.

    2016-07-01

    The Planck collaboration has measured the temperature and polarization of the cosmic microwave background well enough to determine the locations of eight peaks in the temperature (TT) power spectrum, five peaks in the polarization (EE) power spectrum and 12 extrema in the cross (TE) power spectrum. The relative locations of these extrema give a striking, and beautiful, demonstration of what we expect from acoustic oscillations in the plasma; e.g. that EE peaks fall half way between TT peaks. We expect this because the temperature map is predominantly sourced by temperature variations in the last scattering surface, while the polarization map is predominantly sourced by gradients in the velocity field, and the harmonic oscillations have temperature and velocity 90 deg out of phase. However, there are large differences in expectations for extrema locations from simple analytic models versus numerical calculations. Here, we quantitatively explore the origin of these differences in gravitational potential transients, neutrino free-streaming, the breakdown of tight coupling, the shape of the primordial power spectrum, details of the geometric projection from three to two dimensions, and the thickness of the last scattering surface. We also compare the peak locations determined from Planck measurements to expectations under the Λ cold dark matter model. Taking into account how the peak locations were determined, we find them to be in agreement.

  3. Seismo-acoustic array installed in Vrancea seismogenic area

    Science.gov (United States)

    Ionescu, Constantin; Moldovan, Adrian-Septimiu; Moldovan, Iren-Adelina; Ghica, Daniela

    2010-05-01

    The National Institute for Earth Physics (NIEP) has installed two infrasound networks: a four-element seismo-acoustic array with an 1.2 km aperture (IPLOR) and a three-element array with a 400m aperture (IOANE). Both arrays are installed in Vrancea seismogenic area. Each array element of IPLOR consists of three sensors (a seismic 3C broad-band instrument with 1000V/m/s sensitivity, an accelerometer +/-2g EpiSensor type, and an infrasound Chaparral type sensor) and a 24-bit digitizer (Quanterra Q330). The BB sensors and accelerometers are located in 3 meters deep boreholes, while the infrasound sensors are installed in a plastic 1 mc container connected to a porous flexible pipe or plastic tube (for the central element). Inter-array communication is achieved by radio link (2.4 GHz frequency band) which transmits the data from the six-channel digitizers to the local acquisition system. Each power array element consisted of a 12 V DC source powered by the commercial power line or solar panels. The data acquisition system is based on the Seiscomp3 software; a sampling rate of 100 samples per second is applied for BB seismic instruments and accelerometers, whilst for the infrasound sensor a 20 sps rate is used. Each array element of IPLOR consists of a MBAZEL2007 microbarometer and a 24-bit digitizer. Inter-array communication is achieved by a fiber optic link. The sampling rate is 10 sps. The Vrancea seismo-acoustic array is used to identify and locate events associated with industrial blasts, to detect local and regional events, as well for the complex studies on the Vrancea seismogenic area. Moreover, the array data accelerometers are used in the early warning system for Bucharest. At NIEP, several programs are running to analyze each type of data (seismic and acoustic): for BB seismic data, a software for event detection and characterization, kindly provided by NORSAR, is applied, acceleration data recorded by the episensors are processed with a software developed

  4. Achieving acoustic cloak by using compressible background flow

    Science.gov (United States)

    Zhang, Ruo-Yang; Zhao, Qing; Ge, Mo-Lin

    2016-08-01

    We propose a scheme of acoustic spherical cloaking by means of background irrotational flow in compressible fluid. The background flow forms a virtual curved spacetime and directs the sound waves to bypass the cloaked objects. To satisfy the laws of real fluid, we show that spatially distributed mass source and momentum source are necessary to supply. The propagation of sound waves in this system is studied via both geometric acoustics approximation and full wave approach. The analytic solution of sound fields is obtained for plane wave incidence. The results reveal the effect of phase retardation (or lead) in comparison with the ordinary transformation-acoustic cloak. In addition, the ability of cloaking is also evaluated for unideal background flows by analyzing the scattering cross section. Project supported by the National Natural Science Foundation of China (Grant Nos. 11475088 and 11275024) and the Fund from the Ministry of Science and Technology of China (Grant No. 2013YQ030595-3).

  5. Achieving acoustic cloak by using compressible background flow

    CERN Document Server

    Zhang, Ruo-Yang; Ge, Mo-Lin

    2016-01-01

    We propose a scheme of acoustic spherical cloaking by means of background irrotational flow in compressible fluid. The background flow forms a virtual curved spacetime and guides the sound waves bypass the cloaked objects. To satisfy the laws of real fluid, we show that spatially distributed mass source and momentum source are necessary to supply. The propagation of sound waves in this system is studied via both geometric acoustics approximation and full wave approach. The analytic solution of sound fields is obtained for plane wave incidence. The results reveal the effect of phase retardation (or lead) in comparison with the ordinary transformation-acoustic cloak. In addition, the ability of cloaking is also evaluated for unideal background flows by analyzing the scattering cross section.

  6. Acoustic confort at home: Noise emitted by house installations. Recommendations in order to avoid such noise

    Science.gov (United States)

    Jimenez, Santiago

    2002-11-01

    The present survey consists of the analysis and the study of the solutions used at present in the installations of water supply and elevators. It has been carried out from the acoustic point of view. In order to achieve a thorough study a pilot plant was built in the Laboratory of Acoustics of the School of Industrial Engineering of Terrassa. This pilot plant reproduced different kinds of installations of the water supply in houses. And it has allowed us to systematize the measures and also to determine the optimum solutions from the acoustic perspective. In accordance with the objectives and the process of the survey, the solutions regularly employed in the facilities of water supply and elevators in houses have been analyzed, and levels of noise associated to these facilities have been also presented. A summary of the results obtained in the plant has been included, according to diverse variables. Both the conclusions of the analysis of the data obtained in the laboratory and those of the installations of the houses have been also compared, which has allowed us to describe a series of suggestions with the purpose of reducing the acoustic emission of this type of installations, and increase the acoustic comfort at home. (To be presented in Spanish.)

  7. Background studies for acoustic neutrino detection at the South Pole

    CERN Document Server

    Abbasi, R; Abu-Zayyad, T; Adams, J; Aguilar, J A; Ahlers, M; Andeen, K; Auffenberg, J; Bai, X; Baker, M; Barwick, S W; Bay, R; Alba, J L Bazo; Beattie, K; Beatty, J J; Bechet, S; Becker, J K; Becker, K -H; Benabderrahmane, M L; BenZvi, S; Berdrmann, J; Berghaus, P; Berley, D; Bernardini, E; Bertrand, D; Besson, D Z; Bindig, D; Bissok, M; Blaufuss, E; Blumenthal, J; Boersma, D J; Bohm, C; Bose, D; Böser, S; Botner, O; Braun, J; Brown, A M; Buitink, S; Carson, M; Chirkin, D; Christy, B; Clem, J; Clevermann, F; Cohen, S; Colnard, C; Cowen, D F; D'Agostino, M V; Danninger, M; Daughhetee, J; Davis, J C; De Clercq, C; Demirörs, L; Denger, T; Depaepe, O; Descamps, F; Desiati, P; de Vries-Uiterweerd, G; DeYoung, T; Diaz-Vélez, J C; Dierckxsens, M; Dreyer, J; Dumm, J P; Ehrlich, R; Eisch, J; Ellsworth, R W; Engdegård, O; Euler, S; Evenson, P A; Fadiran, O; Fazely, A R; Fedynitch, A; Feusels, T; Filimonov, K; Finley, C; Fischer-Wasels, T; Foerster, M M; Fox, B D; Franckowiak, A; Franke, R; Gaisser, T K; Gallagher, J; Geisler, M; Gerhardt, L; Gladstone, L; Glüsenkamp, T; Goldschmidt, A; Goodman, J A; Grant, D; Griesel, T; Groß, A; Grullon, S; Gurtner, M; Ha, C; Hallgren, A; Halzen, F; Han, K; Hanson, K; Heinen, D; Helbing, K; Herquet, P; Hickford, S; Hill, G C; Hoffman, K D; Homeier, A; Hoshina, K; Hubert, D; Huelsnitz, W; Hülß, J -P; Hulth, P O; Hultqvist, K; Hussain, S; Ishihara, A; Jacobsen, J; Japaridze, G S; Johansson, H; Joseph, J M; Kampert, K -H; Kappes, A; Karg, T; Karle, A; Kelley, J L; Kenny, P; Kiryluk, J; Kislat, F; Klein, S R; Köhne, J -H; Kohnen, G; Kolanoski, H; Köpke, L; Kopper, S; Koskinen, D J; Kowalski, M; Kowarik, T; Krasberg, M; Krings, T; Kroll, G; Kuehn, K; Kuwabara, T; Labare, M; Lafebre, S; Laihem, K; Landsman, H; Larson, M J; Lauer, R; Lünemann, J; Madsen, J; Majumdar, P; Marotta, A; Maruyama, R; Mase, K; Matis, H S; Meagher, K; Merck, M; Mészáros, P; Meures, T; Middell, E; Milke, N; Miller, J; Montaruli, T; Morse, R; Movit, S M; Nahnhauer, R; Nam, J W; Naumann, U; Nießen, P; Nygren, D R; Odrowski, S; Olivas, A; Olivo, M; O'Murchadha, A; Ono, M; Panknin, S; Paul, L; Heros, C Pérez de los; Petrovic, J; Piegsa, A; Pieloth, D; Porrata, R; Posselt, J; Price, P B; Prikockis, M; Przybylski, G T; Rawlins, K; Redl, P; Resconi, E; Rhode, W; Ribordy, M; Rizzo, A; Rodrigues, J P; Roth, P; Rothmaier, F; Rott, C; Ruhe, T; Rutledge, D; Ruzybayev, B; Ryckbosch, D; Sander, H -G; Santander, M; Sarkar, S; Schatto, K; Schmidt, T; Schönwald, A; Schukraft, A; Schultes, A; Schulz, O; Schunck, M; Seckel, D; Semburg, B; Seo, S H; Sestayo, Y; Seunarine, S; Silvestri, A; Slipak, A; Spiczak, G M; Spiering, C; Stamatikos, M; Stanev, T; Stephens, G; Stezelberger, T; Stokstad, R G; Stössl, A; Stoyanov, S; Strahler, E A; Straszheim, T; Stür, M; Sullivan, G W; Swillens, Q; Taavola, H; Taboada, I; Tamburro, A; Tepe, A; Ter-Antonyan, S; Tilav, S; Toale, P A; Toscano, S; Tosi, D; Turčan, D; van Eijndhoven, N; Vandenbroucke, J; Van Overloop, A; van Santen, J; Vehring, M; Voge, M; Walck, C; Waldenmaier, T; Wallraff, M; Walter, M; Weaver, Ch; Wendt, C; Westerhoff, S; Whitehorn, N; Wiebe, K; Wiebusch, C H; Williams, D R; Wischnewski, R; Wissing, H; Wolf, M; Woschnagg, K; Xu, C; Xu, X W; Yodh, G; Yoshida, S; Zarzhitsky, P

    2011-01-01

    The detection of acoustic signals from ultra-high energy neutrino interactions is a promising method to measure the tiny flux of cosmogenic neutrinos expected on Earth. The energy threshold for this process depends strongly on the absolute noise level in the target material. The South Pole Acoustic Test Setup (SPATS), deployed in the upper part of four boreholes of the IceCube Neutrino Observatory, has monitored the noise in Antarctic ice at the geographic South Pole for more than two years down to 500 m depth. The noise is very stable and Gaussian distributed. Lacking an in-situ calibration up to now, laboratory measurements have been used to estimate the absolute noise level in the 10 to 50 kHz frequency range to be smaller than 20 mPa. Using a threshold trigger, sensors of the South Pole Acoustic Test Setup registered acoustic pulse-like events in the IceCube detector volume and its vicinity. Acoustic signals from refreezing IceCube holes and from anthropogenic sources have been used to localize acoustic e...

  8. Background information to the installers guide for small scale mains connected PV

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-07-01

    This report contains background information used by BRE, EA Technology, Halcrows and Sundog when compiling guidance for the UK's New and Renewable Energy Programme on the installation of small-scale photovoltaics (PV) in buildings. The report considers: relevant standards; general safety issues; fire and safety issues, including the fire resistance of PV modules; PV module ratings such as maximum voltage and maximum current; DC cabling; the DC disconnect; the DC junction box; fault analysis; general and AC side earthing; DC earthing; lightning and surge suppression; inverters; AC modules; AC systems; getting connection; mounting options; and installation issues.

  9. Seismo-acoustic Signals Recorded at KSIAR, the Infrasound Array Installed at PS31

    Science.gov (United States)

    Kim, T. S.; Che, I. Y.; Jeon, J. S.; Chi, H. C.; Kang, I. B.

    2014-12-01

    One of International Monitoring System (IMS)'s primary seismic stations, PS31, called Korea Seismic Research Station (KSRS), was installed around Wonju, Korea in 1970s. It has been operated by US Air Force Technical Applications Center (AFTAC) for more than 40 years. KSRS is composed of 26 seismic sensors including 19 short period, 6 long period and 1 broad band seismometers. The 19 short period sensors were used to build an array with a 10-km aperture while the 6 long period sensors were used for a relatively long period array with a 40-km aperture. After KSRS was certified as an IMS station in 2006 by Comprehensive Nuclear Test Ban Treaty Organization (CTBTO), Korea Institute of Geoscience and Mineral Resources (KIGAM) which is the Korea National Data Center started to take over responsibilities on the operation and maintenance of KSRS from AFTAC. In April of 2014, KIGAM installed an infrasound array, KSIAR, on the existing four short period seismic stations of KSRS, the sites KS05, KS06, KS07 and KS16. The collocated KSIAR changed KSRS from a seismic array into a seismo-acoustic array. The aperture of KSIAR is 3.3 km. KSIAR also has a 100-m small aperture infrasound array at KS07. The infrasound data from KSIAR except that from the site KS06 is being transmitted in real time to KIGAM with VPN and internet line. An initial analysis on seismo-acoustic signals originated from local and regional distance ranges has been performed since May 2014. The analysis with the utilization of an array process called Progressive Multi-Channel Correlation (PMCC) detected seismo-acoustic signals caused by various sources including small explosions in relation to constructing local tunnels and roads. Some of them were not found in the list of automatic bulletin of KIGAM. The seismo-acoustic signals recorded by KSIAR are supplying a useful information for discriminating local and regional man-made events from natural events.

  10. Installation for determining hydrogen in metals by the method of vacuum heating with reduced hydrogen background

    International Nuclear Information System (INIS)

    Vacuum heating and vacuum melting are widely employed to determine gases, particularly hydrogen, in metals. Hydrogen in metals can be determined in the accumulation mode when the transducer is not itself pumped. The relatively low sensitivity of these transducers limits the sensitivity of the vacuum-heating method. The sensitivity can be increased when determining hydrogen by using a mass spectrometer. The authors have constructed an installation of this type in an attempt to increase the sensitivity and accuracy of the vacuum-heating method by reducing the background. They have attempted to reduce the background of hydrogen arising from the walls of the roasting chamber and the heater screens by water cooling the roasting-chamber walls, while the area of the heater parts has been kept at a minimum. The penetration of water vapor and other gases containing hydrogen is prevented by the mass-spectrometer transducer being separated from the roasting chamber by a hydrogen trap. The operational properties of the installation are also improved by changing the design of the sample-loading and heating-automation systems

  11. Background noise cancellation for improved acoustic detection of manatee vocalizations

    Science.gov (United States)

    Yan, Zheng; Niezrecki, Christopher; Beusse, Diedrich O.

    2005-06-01

    The West Indian manatee (Trichechus manatus latirostris) has become endangered partly because of an increase in the number of collisions with boats. A device to alert boaters of the presence of manatees, so that a collision can be avoided, is desired. A practical implementation of the technology is dependent on the hydrophone spacing and range of detection. These parameters are primarily dependent on the manatee vocalization strength, the decay of the signal's strength with distance, and the background noise levels. An efficient method to extend the detection range by using background noise cancellation is proposed in this paper. An adaptive line enhancer (ALE) that can detect and track narrow band signals buried in broadband noise is implemented to cancel the background noise. The results indicate that the ALE algorithm can efficiently extract the manatee calls from the background noise. The improved signal-to-noise ratio of the signal can be used to extend the range of detection of manatee vocalizations and reduce the false alarm and missing detection rate in their natural habitat. .

  12. Resource Evaluation and Energy Production Estimate for a Tidal Energy Conversion Installation using Acoustic Flow Measurements

    Science.gov (United States)

    Gagnon, Ian; Baldwin, Ken; Wosnik, Martin

    2015-11-01

    The ``Living Bridge'' project plans to install a tidal turbine at Memorial Bridge in the Piscataqua River at Portsmouth, NH. A spatio-temporal tidal energy resource assessment was performed using long term bottom-deployed Acoustic Doppler Current Profilers ADCP. Two locations were evaluated: at the planned deployment location and mid-channel. The goal was to determine the amount of available kinetic energy that can be converted into usable electrical energy on the bridge. Changes in available kinetic energy with ebb/flood and spring/neap tidal cycles and electrical energy demand were analyzed. A system model is used to calculate the net energy savings using various tidal generator and battery bank configurations. Differences in the tidal characteristics between the two measurement locations are highlighted. Different resource evaluation methodologies were also analyzed, e.g., using a representative ADCP ``bin'' vs. a more refined, turbine-geometry-specific methodology, and using static bin height vs. bin height that move w.r.t. the free surface throughout a tidal cycle (representative of a bottom-fixed or floating turbine deployment, respectively). ADCP operating frequencies and bin sizes affect the standard deviation of measurements, and measurement uncertainties are evaluated. Supported by NSF-IIP grant 1430260.

  13. An acoustically controlled tetherless underwater vehicle for installation and maintenance of neutrino detectors in the deep ocean

    CERN Document Server

    Ballou, P J

    1997-01-01

    The task of installing and servicing high energy neutrino detectors in the deep ocean from a surface support vessel is problematic using conventional tethered systems. An array of multiple detector strings rising 500 m from the ocean floor, and forming a grid with 50 m spacing between the strings, presents a substantial entanglement hazard for equipment cables deployed from the surface. Such tasks may be accomplished with fewer risks using a tetherless underwater remotely operated vehicle that has a local acoustic telemetry link to send control commands and sensor data between the vehicle and a stationary hydrophone suspended above or just outside the perimeter of the work site. The Phase I effort involves the development of an underwater acoustic telemetry link for vehicle control and sensor feedback, the evaluation of video compression methods for real-time acoustic transmission of video through the water, and the defining of local control routines on board the vehicle to allow it to perform certain basic m...

  14. An acoustically controlled tetherless underwater vehicle for installation and maintenance of neutrino detectors in the deep ocean

    Energy Technology Data Exchange (ETDEWEB)

    Ballou, Philip J.

    1997-02-01

    The task of installing and servicing high energy neutrino detectors in the deep ocean from a surface support vessel is problematic using conventional tethered systems. An array of multiple detector strings rising 500 m from the ocean floor, and forming a grid with 50 m spacing between the strings, presents a substantial entanglement hazard for equipment cables deployed from the surface. Such tasks may be accomplished with fewer risks using a tetherless underwater remotely operated vehicle that has a local acoustic telemetry link to send control commands and sensor data between the vehicle and a stationary hydrophone suspended above or just outside the perimeter of the work site. The Phase I effort involves the development of an underwater acoustic telemetry link for vehicle control and sensor feedback, the evaluation of video compression methods for real-time acoustic transmission of video through the water, and the defining of local control routines on board the vehicle to allow it to perform certain basic maneuvering tasks autonomously, or to initiate a self-rescue if the acoustic control link should be lost. In Phase II, a prototype tetherless vehicle system will be designed and constructed to demonstrate the ability to install cable interconnections within a detector array at 4 km depth. The same control technology could be used with a larger more powerful vehicle to maneuver the detector strings into desired positions as they are being lowered to the ocean floor.

  15. An acoustically controlled tetherless underwater vehicle for installation and maintenance of neutrino detectors in the deep ocean

    International Nuclear Information System (INIS)

    The task of installing and servicing high energy neutrino detectors in the deep ocean from a surface support vessel is problematic using conventional tethered systems. An array of multiple detector strings rising 500 m from the ocean floor, and forming a grid with 50 m spacing between the strings, presents a substantial entanglement hazard for equipment cables deployed from the surface. Such tasks may be accomplished with fewer risks using a tetherless underwater remotely operated vehicle that has a local acoustic telemetry link to send control commands and sensor data between the vehicle and a stationary hydrophone suspended above or just outside the perimeter of the work site. The Phase I effort involves the development of an underwater acoustic telemetry link for vehicle control and sensor feedback, the evaluation of video compression methods for real-time acoustic transmission of video through the water, and the defining of local control routines on board the vehicle to allow it to perform certain basic maneuvering tasks autonomously, or to initiate a self-rescue if the acoustic control link should be lost. In Phase II, a prototype tetherless vehicle system will be designed and constructed to demonstrate the ability to install cable interconnections within a detector array at 4 km depth. The same control technology could be used with a larger more powerful vehicle to maneuver the detector strings into desired positions as they are being lowered to the ocean floor

  16. Aharonov-Bohm effect for a fermion field in the acoustic black hole background

    CERN Document Server

    Anacleto, M A; Mohammadi, A; Passos, E

    2016-01-01

    In this paper we consider the dynamics of a massive spinor field in the background of the acoustic black hole spacetime and then compute the differential cross section through the use of the partial wave approach. We show that an effect similar to the gravitational Aharonov-Bohm effect occurs for massive fermion fields moving in this effective metric. We discuss the limiting cases and compare the results with the bosonic case.

  17. First Detection of the Acoustic Oscillation Phase Shift Expected from the Cosmic Neutrino Background.

    Science.gov (United States)

    Follin, Brent; Knox, Lloyd; Millea, Marius; Pan, Zhen

    2015-08-28

    The unimpeded relativistic propagation of cosmological neutrinos prior to recombination of the baryon-photon plasma alters gravitational potentials and therefore the details of the time-dependent gravitational driving of acoustic oscillations. We report here a first detection of the resulting shifts in the temporal phase of the oscillations, which we infer from their signature in the cosmic microwave background temperature power spectrum. PMID:26371637

  18. Acoustic resonance scattering by a system of concentrically multilayered shells: the inherent background and resonance coefficients

    CERN Document Server

    Choi, M S; Lee, S H

    1999-01-01

    The inherent background coefficients that exactly describe the background amplitudes in the scattered field have been presented for the scattering of plane acoustic waves by a system of concentrically multilayered solid and/or fluid shells submerged in a fluid. The coefficients have been obtained by replacing the mechanical surface admittance function with the zero-frequency limit of the admittance function for the analogous fluid system, where the shear wave speeds in the solid layers are set to zero. By taking advantage of the concept of incoming and outgoing waves, we find the surface admittance function for the fluid system in such a form that the analytical generalization for any number of layers and the physical interpretation are very easy. The background coefficients obtained are independent of the bulk wave speeds in the system: they depend on the mass densities and the thickness of the shells. With increasing frequency, the inherent background undergoes a transition from the soft to the rigid backgr...

  19. Long-term measurements of acoustic background noise in very deep sea

    Energy Technology Data Exchange (ETDEWEB)

    Riccobene, G. [Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Via S. Sofia 62, 95123 Catania (Italy)], E-mail: riccobene@lns.infn.it

    2009-06-01

    The NEMO (NEutrino Mediterranean Observatory) Collaboration installed, 25 km E offshore the port of Catania (Sicily) at 2000 m depth, an underwater laboratory to perform long-term tests of prototypes and new technologies for an underwater high energy neutrino km{sup 3}-scale detector in the Mediterranean Sea. In this framework the Collaboration deployed and successfully operated for about two years, starting from January 2005, an experimental apparatus for on-line monitoring of deep-sea noise. The station was equipped with four hydrophones and it is operational in the range 30 Hz-43 kHz. This interval of frequencies matches the range suitable for the proposed acoustic detection technique of high energy neutrinos. Hydrophone signals were digitized underwater at 96 kHz sampling frequency and 24 bits resolution. The stored data library, consisting of more than 2000 h of recordings, is a unique tool to model underwater acoustic noise at large depth, to characterize its variations as a function of environmental parameters, biological sources and human activities (ship traffic, etc.), and to determine the presence of cetaceans in the area.

  20. Online monitoring of Accessories for Underground Electrical Installations through Acoustics Emissions

    Directory of Open Access Journals (Sweden)

    Casals-Torrens P.

    2012-04-01

    Full Text Available The acoustic waves caused by Partial Discharges inside the dielectric materials, can be detected by acoustic emission (AE sensors and analyzed in the time domain. The experimental results presented, show the online detection capability of these sensors in the environment near a cable accessory, such as a splice or terminal. The AE sensors are immune to electromagnetic interference and constitute a detection method non-intrusive and non-destructive, which ensures a galvanic decoupling with respect to electric networks, this technique of partial discharge detection can be applied as a test method for preventive or predictive maintenance (condition-based maintenance to equipments or facilities of medium and high voltage in service and represents an alternative method to electrical detection systems, conventional or not, that continue to rely on the detection of current pulses. This paper presents characterization tests of the sensors AE through comparative tests of partial discharge on accessories for underground power cables.

  1. Sensor development and calibration for acoustic neutrino detection in ice

    OpenAIRE

    Karg, Timo; Bissok, Martin; Laihem, Karim; Semburg, Benjamin; Tosi, Delia; Collaboration, for the IceCube

    2009-01-01

    A promising approach to measure the expected low flux of cosmic neutrinos at the highest energies (E > 1 EeV) is acoustic detection. There are different in-situ test installations worldwide in water and ice to measure the acoustic properties of the medium with regard to the feasibility of acoustic neutrino detection. The parameters of interest include attenuation length, sound speed profile, background noise level and transient backgrounds. The South Pole Acoustic Test Setup (SPATS) has been ...

  2. Investigation of background acoustical effect on online surveys: A case study of a farmers' market customer survey

    Science.gov (United States)

    Tang, Xingdi

    Since the middle of 1990s, internet has become a new platform for surveys. Previous studies have discussed the visual design features of internet surveys. However, the application of acoustics as a design characteristic of online surveys has been rarely investigated. The present study aimed to fill that research gap. The purpose of the study was to assess the impact of background sound on respondents' engagement and satisfaction with online surveys. Two forms of background sound were evaluated; audio recorded in studios and audio edited with convolution reverb technique. The author recruited 80 undergraduate students for the experiment. These students were assigned to one of three groups. Each of the three groups was asked to evaluate their engagement and satisfaction with a specific online survey. The content of the online survey was the same. However, the three groups was exposed to the online survey with no background sound, with background sound recorded in studios; and with background sound edited with convolution reverb technique. The results showed no significant difference in engagement and satisfaction in the three groups of online surveys; without background sound, background sound recorded in studios, and background sound edited with convolution reverb technique. The author suggests that background sound does not contribute to online surveys in all the contexts. The industry practitioners should be careful to evaluate the survey context to decide whether the background sound should be added. Particularly, ear-piercing noise or acoustics which may link to respondents' unpleasant experience should be avoided. Moreover, although the results did not support the advantage of the revolution reverb technique in improving respondents' engagement and satisfaction, the author suggests that the potential of the revolution reverb technique in the applications of online surveys can't be totally denied, since it may be useful for some contexts which need further

  3. Measuring Acoustic Wave Transit Time in Furnace Based on Active Acoustic Source Signal

    Institute of Scientific and Technical Information of China (English)

    Zhen Luo; Feng Tian; Xiao-Ping Sun

    2007-01-01

    Accurate measurement of transit time for acoustic wave between two sensors installed on two sides of a furnace is a key to implementing the temperature field measurement technique based on acoustical method. A new method for measuring transit time of acoustic wave based on active acoustic source signal is proposed in this paper, which includes the followings: the time when the acoustic source signal arrives at the two sensors is measured first; then, the difference of two arriving time arguments is computed, thereby we get the transit time of the acoustic wave between two sensors installed on the two sides of the furnace. Avoiding the restriction on acoustic source signal and background noise, the new method can get the transit time of acoustic wave with higher precision and stronger ability of resisting noise interference.

  4. Results from an Integrated Optical/Acoustic Communication System Installed at CORK 857D: Implications for Future Seafloor Observatories

    Science.gov (United States)

    Tivey, M.; Farr, N.; Ware, J.; Pontbriand, C.

    2011-12-01

    A CORK (Circulation Obviation Retrofit Kit) borehole represents all of the basic components required for a seafloor observatory: a stable environment for long-term continuous measurements of earth and ocean phenomena, access to a unique environment below the seafloor under controlled conditions (e.g. hydrologically sealed), and a standard interface for communication. Typically, however, due to power constraints and a limited frequency of data download opportunities, data sampling has been limited to rates on the order of several minutes. For full seismic wave sampling, at least 1 Hz or better is required. While some CORK systems are now being connected to an underwater cable to provide continuous power and real-time data (cf. Neptune network in the Northeast Pacific), there will be locations where cabled observatories are not viable. Another mode of communication is required to enable both high data rate communication and access for data download via more conventional vessels and not limited to those with ROV or submersibles. We here report on technology to enable high data rate download and transfer of data and information using underwater optical communications, which can be accomplished from a surface vessel of opportunity or, in the future, by autonomous underwater vehicle. In 2010, we successfully deployed and tested an underwater optical communication system that provides high data rate communications over a range of 100 meters from a deep sea CORK borehole observatory located in the northeast Pacific at IODP Hole 857D. The CORK is instrumented with a thermistor string and pressure sensors that record downhole formation pressures and temperatures within oceanic basement and is pressure sealed from the overlying water column. The seafloor Optical Telemetry System (OTS) was plugged into the CORK's existing underwater matable connector to provide an optical and acoustic communication interface and additional data storage and battery power for the CORK to sample

  5. Effect of scanner acoustic background noise on strict resting-state fMRI

    Directory of Open Access Journals (Sweden)

    C. Rondinoni

    2013-04-01

    Full Text Available Functional MRI (fMRI resting-state experiments are aimed at identifying brain networks that support basal brain function. Although most investigators consider a ‘resting-state' fMRI experiment with no specific external stimulation, subjects are unavoidably under heavy acoustic noise produced by the equipment. In the present study, we evaluated the influence of auditory input on the resting-state networks (RSNs. Twenty-two healthy subjects were scanned using two similar echo-planar imaging sequences in the same 3T MRI scanner: a default pulse sequence and a reduced “silent” pulse sequence. Experimental sessions consisted of two consecutive 7-min runs with noise conditions (default or silent counterbalanced across subjects. A self-organizing group independent component analysis was applied to fMRI data in order to recognize the RSNs. The insula, left middle frontal gyrus and right precentral and left inferior parietal lobules showed significant differences in the voxel-wise comparison between RSNs depending on noise condition. In the presence of low-level noise, these areas Granger-cause oscillations in RSNs with cognitive implications (dorsal attention and entorhinal, while during high noise acquisition, these connectivities are reduced or inverted. Applying low noise MR acquisitions in research may allow the detection of subtle differences of the RSNs, with implications in experimental planning for resting-state studies, data analysis, and ergonomic factors.

  6. Effect of scanner acoustic background noise on strict resting-state fMRI

    Directory of Open Access Journals (Sweden)

    C. Rondinoni

    2013-12-01

    Full Text Available Functional MRI (fMRI resting-state experiments are aimed at identifying brain networks that support basal brain function. Although most investigators consider a ‘resting-state' fMRI experiment with no specific external stimulation, subjects are unavoidably under heavy acoustic noise produced by the equipment. In the present study, we evaluated the influence of auditory input on the resting-state networks (RSNs. Twenty-two healthy subjects were scanned using two similar echo-planar imaging sequences in the same 3T MRI scanner: a default pulse sequence and a reduced “silent” pulse sequence. Experimental sessions consisted of two consecutive 7-min runs with noise conditions (default or silent counterbalanced across subjects. A self-organizing group independent component analysis was applied to fMRI data in order to recognize the RSNs. The insula, left middle frontal gyrus and right precentral and left inferior parietal lobules showed significant differences in the voxel-wise comparison between RSNs depending on noise condition. In the presence of low-level noise, these areas Granger-cause oscillations in RSNs with cognitive implications (dorsal attention and entorhinal, while during high noise acquisition, these connectivities are reduced or inverted. Applying low noise MR acquisitions in research may allow the detection of subtle differences of the RSNs, with implications in experimental planning for resting-state studies, data analysis, and ergonomic factors.

  7. Investigation of methods for successful installation and operation of Juvenile Salmon Acoustic Telemetry System (JSATS) hydrophones in the Willamette River, Oregon, 2012

    Science.gov (United States)

    Rutz, Gary L.; Sholtis, Matthew D.; Adams, Noah S.; Beeman, John W.

    2014-01-01

    Acoustic telemetry equipment was installed at three sites in the Willamette River during October 2012 to test the effectiveness of using the Juvenile Salmon Acoustic Telemetry System to monitor the movements of fish in a high-flow, high-velocity riverine environment. Hydrophones installed on concrete blocks were placed on the bottom of the river, and data cables were run from the hydrophones to shore where they were attached to anchor points. Under relatively low-flow conditions (less than approximately 10,000 cubic feet per second) the monitoring system remained in place and could be used to detect tagged fish as they traveled downstream during their seaward migration. At river discharge over approximately 10,000 cubic feet per second, the hydrophones were damaged and cables were lost because of the large volume of woody debris in the river and the increase in water velocity. Damage at two of the sites was sufficient to prevent data collection. A limited amount of data was collected from the equipment at the third site. Site selection and deployment strategies were re-evaluated, and an alternate deployment methodology was designed for implementation in 2013.

  8. Development of Generic Methodology for Designing a Structural Health Monitoring Installation Based on the Acoustic Emission Technique

    NARCIS (Netherlands)

    Gagar, D.; Martinez, M.J.; Foote, P.

    2014-01-01

    The Acoustic Emission (AE) technique can be used to perform damage detection and localisation for structural health monitoring purposes. Implementation in aircraft structures however poses a significant challenge as its performance in terms of damage detection and localisation is not well understood

  9. Development of Generic Methodology for Designing a Structural Health Monitoring Installation Based on the Acoustic Emission Technique

    OpenAIRE

    Gagar, D.; Martinez, M.J.; Foote, P.

    2014-01-01

    The Acoustic Emission (AE) technique can be used to perform damage detection and localisation for structural health monitoring purposes. Implementation in aircraft structures however poses a significant challenge as its performance in terms of damage detection and localisation is not well understood when used with complex structural geometries and variable operational service environments. This paper presents initial developments towards a generic methodology for optimal design of a structura...

  10. Acoustic Emission Detection Applications in High Background Noise Environments%声发射技术在高噪声背景下的检测应用

    Institute of Scientific and Technical Information of China (English)

    田亚团; 蒋仕良; 李杰; 李东

    2013-01-01

    This article describes the acoustic emission (AE) detection technology in high background noise environments.The AE technique was used for on-line detection and analysis of the reformed parts of a gasifier and the acoustic emission test results were re-inspected by conventional NDT methods.The results showed that acoustic emission testing technology could have good correspondence with conventional NDT methods in detecting the defects,which proved the feasibility and effectiveness of acoustic emission in high background noise.The results could provide reference for AE test of similar large-scale petrochemical equipment.%介绍了在高噪声背景下,对某台气化炉改造部位进行声发射检测分析的情况,并采用常规无损检测方法对声发射检测结果进行了复验.结果表明,声发射检测技术与常规无损检测方法发现的缺陷有良好的对应关系,证明声发射检测技术在高噪声背景下的可行性和有效性,为类似大型石化设备声发射检测提供了参考.

  11. Integration of Acoustic Detection Equipment into ANTARES

    CERN Document Server

    Lahmann, R; Graf, K; Hoessl, J; Kappes, A; Karg, T; Katz, U; Naumann, C; Salomon, K

    2005-01-01

    The ANTARES group at the University of Erlangen is working towards the integration of a set of acoustic sensors into the ANTARES Neutrino Telescope. With this setup, tests of acoustic particle detection methods and background studies shall be performed. The ANTARES Neutrino Telescope, which is currently being constructed in the Mediterranean Sea, will be equipped with the infrastructure to accommodate a 3-dimensional array of photomultipliers for the detection of Cherenkov light. Within this infrastructure, the required resources for acoustic sensors are available: Bandwidth for the transmission of the acoustic data to the shore, electrical power for the off-shore electronics and physical space to install the acoustic sensors and to route the connecting cables (transmitting signals and power) into the electronics containers. It will be explained how the integration will be performed with minimal modifications of the existing ANTARES design and which setup is foreseen for the acquisition of the acoustic data.

  12. Designing acoustics for linguistically diverse classrooms: Effects of background noise, reverberation and talker foreign accent on speech comprehension by native and non-native English-speaking listeners

    Science.gov (United States)

    Peng, Zhao Ellen

    The current classroom acoustics standard (ANSI S12.60-2010) recommends core learning spaces not to exceed background noise level (BNL) of 35 dBA and reverberation time (RT) of 0.6 second, based on speech intelligibility performance mainly by the native English-speaking population. Existing literature has not correlated these recommended values well with student learning outcomes. With a growing population of non-native English speakers in American classrooms, the special needs for perceiving degraded speech among non-native listeners, either due to realistic room acoustics or talker foreign accent, have not been addressed in the current standard. This research seeks to investigate the effects of BNL and RT on the comprehension of English speech from native English and native Mandarin Chinese talkers as perceived by native and non-native English listeners, and to provide acoustic design guidelines to supplement the existing standard. This dissertation presents two studies on the effects of RT and BNL on more realistic classroom learning experiences. How do native and non-native English-speaking listeners perform on speech comprehension tasks under adverse acoustic conditions, if the English speech is produced by talkers of native English (Study 1) versus native Mandarin Chinese (Study 2)? Speech comprehension materials were played back in a listening chamber to individual listeners: native and non-native English-speaking in Study 1; native English, native Mandarin Chinese, and other non-native English-speaking in Study 2. Each listener was screened for baseline English proficiency level, and completed dual tasks simultaneously involving speech comprehension and adaptive dot-tracing under 15 acoustic conditions, comprised of three BNL conditions (RC-30, 40, and 50) and five RT scenarios (0.4 to 1.2 seconds). The results show that BNL and RT negatively affect both objective performance and subjective perception of speech comprehension, more severely for non

  13. Nonlinear acoustic landmine detection: comparison of off-target soil background and on-target soil-mine nonlinear effects

    Science.gov (United States)

    Korman, Murray S.; Sabatier, James M.; Pauls, Kathleen E.; Genis, Sean A.

    2006-05-01

    When airborne sound at two primary tones, f I, f II (closely spaced near a resonance) excites the soil surface over a buried landmine, soil wave motion interacts with the landmine generating a scattered surface profile which can be measured over the "target." Profiles at the primaries f I, f II, and nonlinearly generated combination frequencies f I-(f II-f I) and f II+(f II-f I) , 2f I-(f II-f I), f I+f II and 2f II+(f II-f I) (among others) have been measured for a VS 2.2 plastic, inert, anti-tank landmine, buried at 3.6 cm in sifted loess soil and in a gravel road bed. [M.S. Korman and J.M. Sabatier, J. Acoust. Soc. Am. 116, 3354-3369 (2004)]. It is observed that the "on target" to "off target" contrast ratio for the sum frequency component can be ~20 dB higher than for either primary. The vibration interaction between the top-plate interface of a buried plastic landmine and the soil above it appears to exhibit many characteristics of the mesoscopic/nanoscale nonlinear effects that are observed in geomaterials like sandstone. Near resonance, the bending (softening) of a family of increasing amplitude tuning curves, involving the vibration over the landmine, exhibits a linear relationship between the peak particle velocity and corresponding frequency. Tuning curve experiments are performed both on and off the mine in an effort to understand the nonlinearities in each case.

  14. The convergence fluctuation of light by clusters of galaxies - a cosmological test using the second acoustic peak of the microwave background

    CERN Document Server

    Lieu, R

    2004-01-01

    The weak lensing magnification of distant light by clusters of galaxies, assumed to be virialized systems with an NFW density profile, was calculated analytically as a statistical average over a random non-evolving distribution within $z=1$. The effect is exactly cancelled by the Dyer-Roeder beam in between clusters - this conclusion is valid also for an ensemble of spherical clumps of arbitrary density profile. An analytical expression for the variance in the mean magnification is provided, using the general formula from our previous work. The all sky fluctuation in the angular size of the microwave background second acoustic peak, due to the random placement of cluster lenses in the intervening space, is then derived to be $\\approx$ 33 %. Moreover, this standard deviation corresponds to that of a highly skewed magnification distribution, with a long tail extending towards the side of positive magnification, since any negative excursion from the mean cannot cross the hard limit imposed by the Dyer-Roeder emp...

  15. Status and recent results of the South Pole Acoustic Test Setup

    CERN Document Server

    Karg, Timo

    2010-01-01

    The South Pole Acoustic Test Setup (SPATS) has been deployed to study the feasibility of acoustic neutrino detection in Antarctic ice around the South Pole. An array of four strings equipped with acoustic receivers and transmitters, permanently installed in the upper 500 m of boreholes drilled for the IceCube neutrino observatory, and a retrievable transmitter that can be used in the water filled holes before the installation of the IceCube optical strings are used to measure the ice acoustic properties. These include the sound speed and its depth dependence, the attenuation length, the noise level, and the rate and nature of transient background sources in the relevant frequency range from 10 kHz to 100 kHz. SPATS is operating successfully since January 2007 and has been able to either measure or constrain all parameters. We present the latest results of SPATS and discuss their implications for future acoustic neutrino detection activities in Antarctica.

  16. Online monitoring of accessories for underground electrical installations through acoustics emissions; Monitoreo en linea de accesorios de instalaciones electricas subterraneas mediante emisiones acusticas

    Energy Technology Data Exchange (ETDEWEB)

    Casals-Torrens, P. [Universidad Politecnica de Cataluna, Barcelona (Espana)]. E-mail: p.casals@upc.edu; Gonzalez-Parada, A. [Universidad de Guanajuato, Guanajuato (Mexico)]. E-mail: gonzaleza@salamanca.ugto.mx; Bosch-Tous, R. [Universidad Politecnica de Cataluna, Barcelona (Espana)

    2012-04-15

    The acoustic waves caused by Partial Discharges inside the dielectric materials, can be detected by acoustic emission (AE) sensors and analyzed in the time domain. The experimental results presented, show the online detection capability of these sensors in the environment near a cable accessory, such as a splice or terminal. The AE sensors are immune to electromagnetic interference and constitute a detection method non-intrusive and non-destructive, which ensures a galvanic decoupling with respect to electric networks, this technique of partial discharge detection can be applied as a test method for preventive or predictive maintenance (condition-based maintenance) to equipment or facilities of medium and high voltage in service and represents an alternative method to electrical detection systems, conventional or not, that continue to rely on the detection of current pulses. This paper presents characterization tests of the sensors AE through comparative tests of partial discharge on accessories for underground power cables. [Spanish] Las ondas acusticas provocadas por las descargas parciales en el interior de un dielectrico pueden ser detectadas por sensores de Emisiones Acusticas (EA) y analizadas en el dominio del tiempo. Los resultados experimentales que se presentan, evidencian la capacidad de deteccion en linea de estos sensores, en el entorno proximo a un accesorio de cable, empalme o terminal. Los sensores EA son inmunes a las interferencias electromagneticas, son un metodo de deteccion no destructivo y garantizan desacople galvanico respecto a la red electrica; esta tecnica de deteccion de descargas parciales puede ser aplicada como metodo de prueba para mantenimiento preventivo o predictivo (mantenimiento basado en la condicion), en equipos o instalaciones de media y alta tension en servicio, y representa una alternativa a los sistemas electricos de deteccion, convencionales o no, que continuan basandose en la deteccion del impulsos de corriente. En el

  17. Battlefield acoustics

    CERN Document Server

    Damarla, Thyagaraju

    2015-01-01

    This book presents all aspects of situational awareness in a battlefield using acoustic signals. It starts by presenting the science behind understanding and interpretation of sound signals. The book then goes on to provide various signal processing techniques used in acoustics to find the direction of sound source, localize gunfire, track vehicles, and detect people. The necessary mathematical background and various classification and fusion techniques are presented. The book contains majority of the things one would need to process acoustic signals for all aspects of situational awareness in one location. The book also presents array theory, which is pivotal in finding the direction of arrival of acoustic signals. In addition, the book presents techniques to fuse the information from multiple homogeneous/heterogeneous sensors for better detection. MATLAB code is provided for majority of the real application, which is a valuable resource in not only understanding the theory but readers, can also use the code...

  18. Installation Art

    DEFF Research Database (Denmark)

    Petersen, Anne Ring

    . In Installation Art: Between Image and Stage, Anne Ring Petersen aims to change that. She begins by exploring how installation art developed into an interdisciplinary genre in the 1960s, and how its intertwining of the visual and the performative has acted as a catalyst for the generation of new artistic......Despite its large and growing popularity – to say nothing of its near-ubiquity in the world’s art scenes and international exhibitions of contemporary art –installation art remains a form whose artistic vocabulary and conceptual basis have rarely been subjected to thorough critical examination...... phenomena. It investigates how it became one of today’s most widely used art forms, increasingly expanding into consumer, popular and urban cultures, where installation’s often spectacular appearance ensures that it meets contemporary demands for sense-provoking and immersive cultural experiences. The main...

  19. Nuclear installations

    International Nuclear Information System (INIS)

    This document presents the fulfilling of the Brazilian obligations under the Convention on Nuclear Safety. The Chapter 2 of the document contains some details about the existing Brazilian nuclear installations. Also, safety improvements at Angra 1 and aspects of Angra 2 and 3 are reported

  20. Acoustic noise in deep ice and environmental conditions at the South Pole

    CERN Document Server

    Karg, Timo

    2008-01-01

    To study the acoustic properties of the Antarctic ice the South Pole Acoustic Test Setup (SPATS) was installed in the upper part of drill holes for the IceCube neutrino observatory. An important parameter for the design of a future acoustic neutrino telescope is the acoustic background noise in the ice and its spatial and temporal variations. We study the absolute noise level depth profile from SPATS data and discuss systematic uncertainties. The measured noise is very stable over one year of data taking, and we estimate the absolute noise level to be < 10 mPa in the frequency range from 10 kHz to 50 kHz at depths below 200 m. This noise level is of the same order of magnitude as observed by ocean based acoustic neutrino detection projects in good weather conditions.

  1. Sensor development and calibration for acoustic neutrino detection in ice

    CERN Document Server

    Karg, Timo; Laihem, Karim; Semburg, Benjamin; Tosi, Delia

    2009-01-01

    A promising approach to measure the expected low flux of cosmic neutrinos at the highest energies (E > 1 EeV) is acoustic detection. There are different in-situ test installations worldwide in water and ice to measure the acoustic properties of the medium with regard to the feasibility of acoustic neutrino detection. The parameters of interest include attenuation length, sound speed profile, background noise level and transient backgrounds. The South Pole Acoustic Test Setup (SPATS) has been deployed in the upper 500 m of drill holes for the IceCube neutrino observatory at the geographic South Pole. In-situ calibration of sensors under the combined influence of low temperature, high ambient pressure, and ice-sensor acoustic coupling is difficult. We discuss laboratory calibrations in water and ice. Two new laboratory facilities, the Aachen Acoustic Laboratory (AAL) and the Wuppertal Water Tank Test Facility, have been set up. They offer large volumes of bubble free ice (3 m^3) and water (11 m^3) for the devel...

  2. The Cosmic Microwave Background

    OpenAIRE

    Silk, Joseph

    2001-01-01

    This set of lectures provides an overview of the basic theory and phenomenology of the cosmic microwave background. Topics include a brief historical review; the physics of temperature and polarization fluctuations; acoustic oscillations of the primordial plasma; the space of inflationary cosmological models; current and potential constraints on these models from the microwave background; and constraints on inflation.

  3. Handbook of Engineering Acoustics

    CERN Document Server

    Möser, Michael

    2013-01-01

    This book examines the physical background of engineering acoustics, focusing on empirically obtained engineering experience as well as on measurement techniques and engineering methods for prognostics. Its goal is not only to describe the state of art of engineering acoustics but also to give practical help to engineers in order to solve acoustic problems. It deals with the origin, the transmission and the methods of the abating different kinds of air-borne and structure-borne sounds caused by various mechanisms – from traffic to machinery and flow-induced sound. In addition the modern aspects of room and building acoustics, as well as psychoacoustics and active noise control, are covered.

  4. Acoustic vector sensor signal processing

    Institute of Scientific and Technical Information of China (English)

    SUN Guiqing; LI Qihu; ZHANG Bin

    2006-01-01

    Acoustic vector sensor simultaneously, colocately and directly measures orthogonal components of particle velocity as well as pressure at single point in acoustic field so that is possible to improve performance of traditional underwater acoustic measurement devices or detection systems and extends new ideas for solving practical underwater acoustic engineering problems. Although acoustic vector sensor history of appearing in underwater acoustic area is no long, but with huge and potential military demands, acoustic vector sensor has strong development trend in last decade, it is evolving into a one of important underwater acoustic technology. Under this background, we try to review recent progress in study on acoustic vector sensor signal processing, such as signal detection, DOA estimation, beamforming, and so on.

  5. Background Lamb waves in the Earth's atmosphere

    Science.gov (United States)

    Nishida, K.; Kobayashi, N.; Fukao, Y.

    2013-12-01

    Lamb waves of the Earth's atmosphere in the millihertz band have been considered as transient phenomena excited only by large events [e.g. the major volcanic eruption of Krakatoa in 1833, the impact of Siberian meteorite in 1908, the testing of large nuclear tests and the huge earthquakes, Garrett1969]. In a case of the solid Earth, observation of background free oscillations in the millihertz band-now known as Earth's background free oscillations or seismic hum, has been firmly established. Above 5 mHz, their dominant excitation sources are oceanic infragravity waves. At 3.7 and 4.4 mHz an elasto-acoustic resonance between the solid Earth and the atmosphere was observed [Nishida et al., 2000]. These seismic observations show that the contribution of atmospheric disturbances to the seismic hum is dominant below 5 mHz. Such contribution implies background excitations of acoustic-gravity waves in this frequency range. For direct detection of the background acoustic-gravity waves, our group conducted observations using an array of barometers [Nishida et al. 2005]. However, the spatial scale of the array of about 10 km was too small to detect acoustic modes below 10 mHz. Since then, no direct observations of these waves have been reported. In 2011, 337 high-resolution microbarometers were installed on a continental scale at USArray Transportable Array. The large and dense array enables us to detect the background atmospheric waves. Here, we show the first evidence of background Lamb waves in the Earth's atmosphere from 0.2 to 10 mHz, based on the array analysis of microbarometer data from the USArray in 2012. The observations suggest that the excitation sources are atmospheric disturbances in the troposphere. Theoretically, their energy in the troposphere tunnels into the thermosphere at a resonant frequency via thermospheric gravity wave, where the observed amplitudes indeed take a local minimum. The energy leak through the frequency window could partly contribute to

  6. Nicotine Withdrawal Disrupts Both Foreground and Background Contextual Fear Conditioning but not Pre-Pulse Inhibition of the Acoustic Startle Response in C57BL/6 Mice

    OpenAIRE

    André, Jessica M.; Gulick, Danielle; Portugal, George S.; Gould, Thomas J.

    2008-01-01

    Nicotine withdrawal is associated with multiple symptoms such as anxiety, increased appetite, and disrupted cognition in humans. Although animal models have provided insights into the somatic and affective symptoms of nicotine withdrawal, less research has focused on the effects of nicotine withdrawal on cognition. Therefore, in this study, C57BL/6 mice were used to test the effects of withdrawal from chronic nicotine on foreground and background contextual fear conditioning, which present th...

  7. First ALICE detectors installed!

    CERN Multimedia

    2006-01-01

    Detectors to track down penetrating muon particles are the first to be placed in their final position in the ALICE cavern. The Alice muon spectrometer: in the foreground the trigger chamber is positioned in front of the muon wall, with the dipole magnet in the background. After the impressive transport of its dipole magnet, ALICE has begun to fill the spectrometer with detectors. In mid-July, the ALICE muon spectrometer team achieved important milestones with the installation of the trigger and the tracking chambers of the muon spectrometer. They are the first detectors to be installed in their final position in the cavern. All of the eight half planes of the RPCs (resistive plate chambers) have been installed in their final position behind the muon filter. The role of the trigger detector is to select events containing a muon pair coming, for instance, from the decay of J/ or Y resonances. The selection is made on the transverse momentum of the two individual muons. The internal parts of the RPCs, made o...

  8. Communication Acoustics

    DEFF Research Database (Denmark)

    Blauert, Jens

    Communication Acoustics deals with the fundamentals of those areas of acoustics which are related to modern communication technologies. Due to the advent of digital signal processing and recording in acoustics, these areas have enjoyed an enormous upswing during the last 4 decades. The book...... the book a source of valuable information for those who want to improve or refresh their knowledge in the field of communication acoustics - and to work their way deeper into it. Due to its interdisciplinary character Communication Acoustics is bound to attract readers from many different areas, such as......: acoustics, cognitive science, speech science, and communication technology....

  9. Background noise levels and correlation with ship traffic in the Gulf of Catania

    Science.gov (United States)

    Viola, Salvatore; Buscaino, Giuseppa; Caruso, Francesco; Chierici, Francesco; Embriaco, Davide; Favali, Paolo; Giovanetti, Gabriele; Grammauta, Roasario; Larosa, Giuseppina; Pavan, Gianni; Pellegrino, Carmelo; Pulvirenti, Sara; Riccobene, Giorgio; Sciacca, Virginia; Simeone, Francesco; Beranzoli, Laura; Marinaro, Giuditta

    2015-04-01

    In the last decades the growing interest in the evaluation of the underwater acoustic noise for studies in the fields of geology, biology and high-energy physics is driving the scientific community to collaborate towards a multidisciplinary approach to the topic. In June 2012 in the framework of the European project EMSO, a multidisciplinary underwater observatory, named NEMO-SN1, was installed 25 km off-shore the port of Catania, at a depth of 2100 m and operated until May 2013 by INFN (Istituto Nazionale di Fisica Nucleare) and INGV (Istituto Nazionale di Geofisica e Vulcanologia). NEMO-SN1 hosted aboard geophysical, oceanographic and acoustic sensors: among these a seismic hydrophone model SMID DT-405D(V). In this work, conducted within the activity of the SMO project, the results on the evaluation of the underwater acoustic pollution in the Gulf of Catania through SMID DT-405D(V) recordings are presented. The seismic hydrophone provided a data set of about 11 months of continuous (24/7) recordings. Underwater sounds have been continuously digitized at a sampling frequency of 2 kHz and the acquired data have been stored in 10min long files for off-line analysis. To describe one-year background noise levels, the mean integrated acoustic noise was measured every second (sampling frequency 2000, NFFT 2048) in the 1/3 octave bands with centre frequency 63 Hz and for each 10 minutes-long file the 5th, the 50th and the 98th percentiles were calculated. Measured noise was correlated with the shipping traffic in the area, thanks to the data provided by an AIS receiver installed at the INFN-Laboratori Nazionali del Sud. An acoustic noise increment was measured in coincidence with the passing of crafts in the area and it was possible to identify the characteristic spectrum of each ship. A simple model for the estimation of the acoustic noise induced by the ships passing through the area was developed. The model was applied by using AIS data acquired during the operation

  10. Acoustic Neuroma

    Science.gov (United States)

    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 ...

  11. Acoustic sniper localization system

    Science.gov (United States)

    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.

  12. Acoustic integrated extinction

    CERN Document Server

    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. [1] 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.

  13. An acoustic invisible gateway

    CERN Document Server

    Zhu, Yi-Fan; Liang, Bin; Kan, Wei-Wei; Yang, Jun; Cheng, Jian-Chun

    2015-01-01

    The recently-emerged concept of "invisible gateway" with the extraordinary capability to block the waves but allow the passage of other entities has attracted great attentions due to the general interests in illusion devices. However, the possibility to realize such a fascinating phenomenon for acoustic waves has not yet been explored, which should be of paramount significance for acoustical applications but would necessarily involve experimental difficulty. Here we design and experimentally demonstrate an acoustic invisible gateway (AIG) capable of concealing a channel under the detection of sound. Instead of "restoring" a whole block of background medium by using transformation acoustics that inevitably requires complementary or restoring media with extreme parameters, we propose an inherently distinct methodology that only aims at engineering the surface impedance at the "gate" to mimic a rigid "wall" and can be conveniently implemented by decorating meta-structures behind the channel. Such a simple yet ef...

  14. Status and Recent Results of the Acoustic Neutrino Detection Test System AMADEUS

    CERN Document Server

    ,

    2011-01-01

    The AMADEUS system is an integral part of the ANTARES neutrino telescope in the Mediterranean Sea. The project aims at the investigation of techniques for acoustic neutrino detection in the deep sea. Installed at a depth of more than 2000m, the acoustic sensors of AMADEUS are based on piezo-ceramics elements for the broad-band recording of signals with frequencies ranging up to 125kHz. AMADEUS was completed in May 2008 and comprises six "acoustic clusters", each one holding six acoustic sensors that are arranged at distances of roughly 1m from each other. The clusters are installed with inter-spacings ranging from 15m to 340m. Acoustic data are continuously acquired and processed at a computer cluster where online filter algorithms are applied to select a high-purity sample of neutrino-like signals. 1.6 TB of data were recorded in 2008 and 3.2 TB in 2009. In order to assess the background of neutrino-like signals in the deep sea, the characteristics of ambient noise and transient signals have been investigate...

  15. Nuclear Installations Act 1965

    International Nuclear Information System (INIS)

    This Act governs all activities related to nuclear installations in the United Kingdom. It provides for the licensing procedure for nuclear installations, the duties of licensees, the competent authorities and carriers of nuclear material in respect of nuclear occurrences, as well as for the system of third party liability and compensation for nuclear damage. The Act repeals the Nuclear Installations (Licensing and Insurance) Act 1959 and the Nuclear Installations (Amendment Act) 1965 except for its Section 17(2). (NEA)

  16. Underwater Acoustic Networking Techniques

    CERN Document Server

    Otnes, Roald; Casari, Paolo; Goetz, Michael; Husøy, Thor; Nissen, Ivor; Rimstad, Knut; van Walree, Paul; Zorzi, Michele

    2012-01-01

    This literature study presents an overview of underwater acoustic networking. It provides a background and describes the state of the art of all networking facets that are relevant for underwater applications. This report serves both as an introduction to the subject and as a summary of existing protocols, providing support and inspiration for the development of network architectures.

  17. Acoustical Imaging

    CERN Document Server

    Litniewski, Jerzy; Kujawska, Tamara; 31st International Symposium on Acoustical Imaging

    2012-01-01

    The International Symposium on Acoustical Imaging is a unique forum for advanced research, covering new technologies, developments, methods and theories in all areas of acoustics. This interdisciplinary Symposium has been taking place continuously since 1968. In the course of the years the proceedings volumes in the Acoustical Imaging Series have become a reference for cutting-edge research in the field. In 2011 the 31st International Symposium on Acoustical Imaging was held in Warsaw, Poland, April 10-13. Offering both a broad perspective on the state-of-the-art as well as  in-depth research contributions by the specialists in the field, this Volume 31 in the Series contains an excellent collection of papers in six major categories: Biological and Medical Imaging Physics and Mathematics of Acoustical Imaging Acoustic Microscopy Transducers and Arrays Nondestructive Evaluation and Industrial Applications Underwater Imaging

  18. Acoustic textiles

    CERN Document Server

    Nayak, Rajkishore

    2016-01-01

    This book highlights the manufacturing and applications of acoustic textiles in various industries. It also includes examples from different industries in which acoustic textiles can be used to absorb noise and help reduce the impact of noise at the workplace. Given the importance of noise reduction in the working environment in several industries, the book offers a valuable guide for companies, educators and researchers involved with acoustic materials.

  19. Radiation acoustics

    CERN Document Server

    Lyamshev, Leonid M

    2004-01-01

    Radiation acoustics is a developing field lying at the intersection of acoustics, high-energy physics, nuclear physics, and condensed matter physics. Radiation Acoustics is among the first books to address this promising field of study, and the first to collect all of the most significant results achieved since research in this area began in earnest in the 1970s.The book begins by reviewing the data on elementary particles, absorption of penetrating radiation in a substance, and the mechanisms of acoustic radiation excitation. The next seven chapters present a theoretical treatment of thermoradiation sound generation in condensed media under the action of modulated penetrating radiation and radiation pulses. The author explores particular features of the acoustic fields of moving thermoradiation sound sources, sound excitation by single high-energy particles, and the efficiency and optimal conditions of thermoradiation sound generation. Experimental results follow the theoretical discussions, and these clearl...

  20. LHC installation planning

    CERN Document Server

    Weisz, S

    2005-01-01

    installation of the general services, the installation of the cryogenic line (QRL), the installation of the machine elements and the hardware commissioning. While the installation of the general services is now almost finished (see presentation by Katy Foraz and Serge Grillot), several problems and delays with the QRL made it unavoidable to revise the installation strategy and to schedule a number tasks in parallel. A new compressed installation planning has been issued, that fulfils the strategic objectives and allows starting new activities with minimal delays in sectors 7-8 and 8-1. However, the shortcuts that are introduced increase the level of risk that we will have to face and the coordination of such a large and complex variety of simultaneous activities makes the project even more challenging. The document will describe how the input from the different equipment groups is taken into account by the master schedule planning team with respect to equipment availability and production as well as logistics...

  1. Getting Good Installation Guides

    OpenAIRE

    Karlström, Erik; Nydén, Johan

    2010-01-01

    Implementations and installations of Enterprise Resource Planning systems (ERP-systems)are often time consuming and complex processes. Technicians who workwith installations of ERP-systems require tools and utilities in order to perform theirwork in a time efficient and qualitative manner.This study is performed at the company Industrial and Financial Systems (IFS) inLinköping and has focused on the technical documentation that describes theinstallation process, "IFS Installation Guide". This...

  2. Electrical installation calculations

    CERN Document Server

    Watkins, AJ

    2006-01-01

    Designed to provide a step by step guide to successful application of the electrical installation calculations required in day to day electrical engineering practice, the Electrical Installation Calculations series has proved an invaluable reference for over forty years, for both apprentices and professional electrical installation engineers alike.Now in its seventh edition, Volume 1 has been fully updated to meet the requirements of the 2330 Level 2 Certificate in Electrotechnical Technology from City & Guilds, and will also prove a vi

  3. Influence of Abnormal Blade Installation Angle on Aerodynamic and Acoustic Characteristics of Axial Flow Fan Under Variable Working Conditions%变工况下动叶安装角异常对轴流风机气动和噪声特性的影响

    Institute of Scientific and Technical Information of China (English)

    李春曦; 尹攀; 叶学民

    2013-01-01

    基于雷诺时均方程和Realizablek-ε湍流模型,采用数值计算方法模拟了带后导叶OB-84型轴流风机在变工况下单叶片安装角偏离对风机内流场特征和运行性能的影响.结果表明:随异常叶片安装角偏离度△β增大,全压和效率总体呈降低趋势,异常叶片反向偏离时对运行性能的影响总体小于正向偏离情形;安装角偏离将引起风机流场总压和噪声分布的畸变,随△β增大,其影响区由周向相邻流道的低压区和高噪区扩展至包括周向下游多个流道的低压带和高噪带;随流量增加,不同△β下异常叶片的影响呈现明显不同的特征.%Based on Reynolds time-averaged equation and Realizable k-ε turbulent model,the internal dynamics and operating performance of an OB 84 axial flow fan with rear guide vane were numerically simulated in full flow passage by considering the effect of abnormal installation angle of single blade.Results show that the total pressure and efficiency tend to decrease with the rise of installation angle deviation △β,and the effect of cocurrent deviation is generally more remarkable than that of countercurrent deviation.The deviation of installation angle may cause deformation of total pressure and acoustic distribution,and with the rise of △β,the deformed region may be expanded from the lower pressure and higher noise region in circumferentially adjacent flow passage to the lower pressure and higher noise strips covering the circumferential downstream multi passages.With the increase of flowrate,the influence of installation angle deviation is different on the internal dynamics and operating performance of axial flow fan.

  4. Electrical installation calculations basic

    CERN Document Server

    Kitcher, Christopher

    2013-01-01

    All the essential calculations required for basic electrical installation workThe Electrical Installation Calculations series has proved an invaluable reference for over forty years, for both apprentices and professional electrical installation engineers alike. The book provides a step-by-step guide to the successful application of electrical installation calculations required in day-to-day electrical engineering practice. A step-by-step guide to everyday calculations used on the job An essential aid to the City & Guilds certificates at Levels 2 and 3Fo

  5. Electrical installations and regulations

    CERN Document Server

    Whitfield, J F

    1966-01-01

    Electrical Installations and Regulations focuses on the regulations that apply to electrical installations and the reasons for them. Topics covered range from electrical science to alternating and direct current supplies, as well as equipment for providing protection against excess current. Cables, wiring systems, and final subcircuits are also considered, along with earthing, discharge lighting, and testing and inspection.Comprised of 12 chapters, this book begins with an overview of electrical installation work, traits of a good electrician, and the regulations governing installations. The r

  6. Electrical installation calculations advanced

    CERN Document Server

    Kitcher, Christopher

    2013-01-01

    All the essential calculations required for advanced electrical installation workThe Electrical Installation Calculations series has proved an invaluable reference for over forty years, for both apprentices and professional electrical installation engineers alike. The book provides a step-by-step guide to the successful application of electrical installation calculations required in day-to-day electrical engineering practiceA step-by-step guide to everyday calculations used on the job An essential aid to the City & Guilds certificates at Levels 2 and 3For apprentices and electrical installatio

  7. Estimating SCR installation costs

    Energy Technology Data Exchange (ETDEWEB)

    Marano, M.; Sharp, G. [American Electric Power (United States)

    2006-01-15

    The EUCG surveyed 72 separate US installations of selective catalytic reduction (SCR) systems at coal-fired units totalling 41 GW of capacity to identify the systems' major cost drivers. The results, summarized in this article, provide excellent first-order estimates and guidance for utilities considering installing the downstream emissions-control technology. 4 figs., 1 tab.

  8. AMADEUS-The acoustic neutrino detection test system of the ANTARES deep-sea neutrino telescope

    International Nuclear Information System (INIS)

    The AMADEUS (ANTARES Modules for the Acoustic Detection Under the Sea) system which is described in this article aims at the investigation of techniques for acoustic detection of neutrinos in the deep sea. It is integrated into the ANTARES neutrino telescope in the Mediterranean Sea. Its acoustic sensors, installed at water depths between 2050 and 2300 m, employ piezo-electric elements for the broad-band recording of signals with frequencies ranging up to 125 kHz. The typical sensitivity of the sensors is around -145 dB re 1 V/μPa (including preamplifier). Completed in May 2008, AMADEUS consists of six 'acoustic clusters', each comprising six acoustic sensors that are arranged at distances of roughly 1 m from each other. Two vertical mechanical structures (so-called lines) of the ANTARES detector host three acoustic clusters each. Spacings between the clusters range from 14.5 to 340 m. Each cluster contains custom-designed electronics boards to amplify and digitise the acoustic signals from the sensors. An on-shore computer cluster is used to process and filter the data stream and store the selected events. The daily volume of recorded data is about 10 GB. The system is operating continuously and automatically, requiring only little human intervention. AMADEUS allows for extensive studies of both transient signals and ambient noise in the deep sea, as well as signal correlations on several length scales and localisation of acoustic point sources. Thus the system is excellently suited to assess the background conditions for the measurement of the bipolar pulses expected to originate from neutrino interactions.

  9. AMADEUS-The acoustic neutrino detection test system of the ANTARES deep-sea neutrino telescope

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar, J.A. [IFIC - Instituto de Fisica Corpuscular, Edificios Investigacion de Paterna, CSIC - Universitat de Valencia, Apdo. de Correos 22085, 46071 Valencia (Spain); Al Samarai, I. [CPPM - Centre de Physique des Particules de Marseille, CNRS/IN2P3 et Universite de la Mediterranee, 163 Avenue de Luminy, Case 902, 13288 Marseille Cedex 9 (France); Albert, A. [GRPHE - Institut Universitaire de Technologie de Colmar, 34 rue du Grillenbreit BP 50568, 68008 Colmar (France); Anghinolfi, M. [INFN - Sezione di Genova, Via Dodecaneso 33, 16146 Genova (Italy); Anton, G. [Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Erlangen Centre for Astroparticle Physics, Erwin-Rommel-Str. 1, 91058 Erlangen (Germany); Anvar, S. [Direction des Sciences de la Matiere - Institut de Recherche sur les lois fondamentales de l' Univers - Service d' Electronique des Detecteurs et d' Informatique, CEA Saclay, 91191 Gif-sur-Yvette Cedex (France); Ardid, M. [Institut d' Investigacio per a la Gestio Integrada de Zones Costaneres (IGIC) - Universitat Politecnica de Valencia. C/ Paranimf 1., 46730 Gandia (Spain); Assis Jesus, A.C.; Astraatmadja, T. [FOM Instituut voor Subatomaire Fysica Nikhef, Science Park 105, 1098 XG Amsterdam (Netherlands); Aubert, J.-J. [CPPM - Centre de Physique des Particules de Marseille, CNRS/IN2P3 et Universite de la Mediterranee, 163 Avenue de Luminy, Case 902, 13288 Marseille Cedex 9 (France); Auer, R. [Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Erlangen Centre for Astroparticle Physics, Erwin-Rommel-Str. 1, 91058 Erlangen (Germany); Barbarito, E. [INFN - Sezione di Bari, Via E. Orabona 4, 70126 Bari (Italy); Baret, B. [APC - Laboratoire AstroParticule et Cosmologie, UMR 7164 (CNRS, Universite Paris 7 Diderot, CEA, Observatoire de Paris) 10, rue Alice Domon et Leonie Duquet, 75205 Paris Cedex 13 (France); Basa, S. [LAM - Laboratoire d' Astrophysique de Marseille, Pole de l' Etoile Site de Chateau-Gombert, 13388 Marseille Cedex 13 (France)

    2011-01-21

    The AMADEUS (ANTARES Modules for the Acoustic Detection Under the Sea) system which is described in this article aims at the investigation of techniques for acoustic detection of neutrinos in the deep sea. It is integrated into the ANTARES neutrino telescope in the Mediterranean Sea. Its acoustic sensors, installed at water depths between 2050 and 2300 m, employ piezo-electric elements for the broad-band recording of signals with frequencies ranging up to 125 kHz. The typical sensitivity of the sensors is around -145 dB re 1 V/{mu}Pa (including preamplifier). Completed in May 2008, AMADEUS consists of six 'acoustic clusters', each comprising six acoustic sensors that are arranged at distances of roughly 1 m from each other. Two vertical mechanical structures (so-called lines) of the ANTARES detector host three acoustic clusters each. Spacings between the clusters range from 14.5 to 340 m. Each cluster contains custom-designed electronics boards to amplify and digitise the acoustic signals from the sensors. An on-shore computer cluster is used to process and filter the data stream and store the selected events. The daily volume of recorded data is about 10 GB. The system is operating continuously and automatically, requiring only little human intervention. AMADEUS allows for extensive studies of both transient signals and ambient noise in the deep sea, as well as signal correlations on several length scales and localisation of acoustic point sources. Thus the system is excellently suited to assess the background conditions for the measurement of the bipolar pulses expected to originate from neutrino interactions.

  10. Early-Onset Alcohol Dependence Increases the Acoustic Startle Reflex

    NARCIS (Netherlands)

    Schellekens, A.F.A.; Mulders, P.C.R.; Ellenbroek, B.A.; Jong, C.A.J. de; Buitelaar, J.K.; Cools, A.R.; Verkes, R.J.

    2012-01-01

    Background: Hyperreactivity and impaired sensory gating of the acoustic startle response in alcohol dependence has been suggested to reflect a residual effect of previous detoxifications, increasing the severity of subsequent withdrawal episodes. Previous studies on the acoustic startle only include

  11. Room Acoustics

    Science.gov (United States)

    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.

  12. Acoustical Imaging

    CERN Document Server

    Akiyama, Iwaki

    2009-01-01

    The 29th International Symposium on Acoustical Imaging was held in Shonan Village, Kanagawa, Japan, April 15-18, 2007. This interdisciplinary Symposium has been taking place every two years since 1968 and forms a unique forum for advanced research, covering new technologies, developments, methods and theories in all areas of acoustics. In the course of the years the volumes in the Acoustical Imaging Series have developed and become well-known and appreciated reference works. Offering both a broad perspective on the state-of-the-art in the field as well as an in-depth look at its leading edge research, this Volume 29 in the Series contains again an excellent collection of seventy papers presented in nine major categories: Strain Imaging Biological and Medical Applications Acoustic Microscopy Non-Destructive Evaluation and Industrial Applications Components and Systems Geophysics and Underwater Imaging Physics and Mathematics Medical Image Analysis FDTD method and Other Numerical Simulations Audience Researcher...

  13. Acoustics Research

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fisheries acoustics data are collected from more than 200 sea-days each year aboard the FRV DELAWARE II and FRV ALBATROSS IV (decommissioned) and the FSV Henry B....

  14. Berkeley Low Background Facility

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, K. J.; Norman, E. B. [Department of Nuclear Engineering, University of California-Berkeley, CA 94720 (United States); Nuclear Science Division, Lawrence Berkeley National Laboratory, CA 94720 (United States); Smith, A. R.; Poon, A. W. P.; Chan, Y. D. [Nuclear Science Division, Lawrence Berkeley National Laboratory, CA 94720 (United States); Lesko, K. T. [Physics Division, Lawrence Berkeley National Laboratory, CA 94720 (United States)

    2015-08-17

    The Berkeley Low Background Facility (BLBF) at Lawrence Berkeley National Laboratory (LBNL) in Berkeley, California provides low background gamma spectroscopy services to a wide array of experiments and projects. The analysis of samples takes place within two unique facilities; locally within a carefully-constructed, low background laboratory on the surface at LBNL and at the Sanford Underground Research Facility (SURF) in Lead, SD. These facilities provide a variety of gamma spectroscopy services to low background experiments primarily in the form of passive material screening for primordial radioisotopes (U, Th, K) or common cosmogenic/anthropogenic products; active screening via neutron activation analysis for U,Th, and K as well as a variety of stable isotopes; and neutron flux/beam characterization measurements through the use of monitors. A general overview of the facilities, services, and sensitivities will be presented. Recent activities and upgrades will also be described including an overview of the recently installed counting system at SURF (recently relocated from Oroville, CA in 2014), the installation of a second underground counting station at SURF in 2015, and future plans. The BLBF is open to any users for counting services or collaboration on a wide variety of experiments and projects.

  15. Berkeley Low Background Facility

    International Nuclear Information System (INIS)

    The Berkeley Low Background Facility (BLBF) at Lawrence Berkeley National Laboratory (LBNL) in Berkeley, California provides low background gamma spectroscopy services to a wide array of experiments and projects. The analysis of samples takes place within two unique facilities; locally within a carefully-constructed, low background laboratory on the surface at LBNL and at the Sanford Underground Research Facility (SURF) in Lead, SD. These facilities provide a variety of gamma spectroscopy services to low background experiments primarily in the form of passive material screening for primordial radioisotopes (U, Th, K) or common cosmogenic/anthropogenic products; active screening via neutron activation analysis for U,Th, and K as well as a variety of stable isotopes; and neutron flux/beam characterization measurements through the use of monitors. A general overview of the facilities, services, and sensitivities will be presented. Recent activities and upgrades will also be described including an overview of the recently installed counting system at SURF (recently relocated from Oroville, CA in 2014), the installation of a second underground counting station at SURF in 2015, and future plans. The BLBF is open to any users for counting services or collaboration on a wide variety of experiments and projects

  16. Background Material

    DEFF Research Database (Denmark)

    Zandersen, Marianne; Hyytiäinen, Kari; Saraiva, Sofia;

    2016-01-01

    This document serves as a background material to the BONUS Pilot Scenario Workshop, which aims to develop harmonised regional storylines of socio-ecological futures in the Baltic Sea region in a collaborative effort together with other BONUS projects and stakeholders.......This document serves as a background material to the BONUS Pilot Scenario Workshop, which aims to develop harmonised regional storylines of socio-ecological futures in the Baltic Sea region in a collaborative effort together with other BONUS projects and stakeholders....

  17. Construction, fabrication, and installation

    International Nuclear Information System (INIS)

    This standard specifies the construction, fabrication, and installation requirements that apply to concrete containment structures of a containment system designated as class containment components, parts and appurtenances for nuclear power plants

  18. Visiting the SPS installation

    CERN Multimedia

    1975-01-01

    ...., Guenther Loehr, Hans Horisberger walk along the SPS tunnel: here, on the right, an absorber block of 22 tons for beam dumping in the external beam lines. The chariot serves for the installation of the block.

  19. 3D Projection Installations

    DEFF Research Database (Denmark)

    Halskov, Kim; Johansen, Stine Liv; Bach Mikkelsen, Michelle

    2014-01-01

    Three-dimensional projection installations are particular kinds of augmented spaces in which a digital 3-D model is projected onto a physical three-dimensional object, thereby fusing the digital content and the physical object. Based on interaction design research and media studies, this article...... contributes to the understanding of the distinctive characteristics of such a new medium, and identifies three strategies for designing 3-D projection installations: establishing space; interplay between the digital and the physical; and transformation of materiality. The principal empirical case, From...... Fingerplan to Loop City, is a 3-D projection installation presenting the history and future of city planning for the Copenhagen area in Denmark. The installation was presented as part of the 12th Architecture Biennale in Venice in 2010....

  20. Biggest semiconductor installed

    CERN Multimedia

    2008-01-01

    Scientists and technicians at the European Laboratory for Particle Physics, commonly known by its French acronym CERN (Centre Europen pour la Recherche Nuclaire), have completed the installation of the largest semiconductor silicon detector.

  1. Organisationskultur i Virum Installation

    OpenAIRE

    Dansgaard, Peter Ulrik; Monberg, Thomas; Petersen, Kristoffer Just

    2013-01-01

    This report identifies the organizational culture in the electrician company, Virum Installation, and examines which elements of the organizational culture that contributes positively as well as negatively to the integration of new employees. The main research question is: How is the phenomenon of corporate culture constituted in Virum Installation, and witch forces and mechanisms are acting as barriers in regards to the integration of new employees? Based on Claus Nygaard's methodical approa...

  2. Installing the World

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    THE art of installation is an art about concept," explains Qing Qing Chen. The artist wants her audience to look at the development of aesthetics from a pluralistic angle on life. Unlike the expressive format of "art in the frame," the art of installation belongs to the category of "non-framed art." The choice of materials used is as important to expression as the creator’s ideas. Whereas only certain materials can be

  3. Acoustic biosensors.

    Science.gov (United States)

    Fogel, Ronen; Limson, Janice; Seshia, Ashwin A

    2016-06-30

    Resonant and acoustic wave devices have been researched for several decades for application in the gravimetric sensing of a variety of biological and chemical analytes. These devices operate by coupling the measurand (e.g. analyte adsorption) as a modulation in the physical properties of the acoustic wave (e.g. resonant frequency, acoustic velocity, dissipation) that can then be correlated with the amount of adsorbed analyte. These devices can also be miniaturized with advantages in terms of cost, size and scalability, as well as potential additional features including integration with microfluidics and electronics, scaled sensitivities associated with smaller dimensions and higher operational frequencies, the ability to multiplex detection across arrays of hundreds of devices embedded in a single chip, increased throughput and the ability to interrogate a wider range of modes including within the same device. Additionally, device fabrication is often compatible with semiconductor volume batch manufacturing techniques enabling cost scalability and a high degree of precision and reproducibility in the manufacturing process. Integration with microfluidics handling also enables suitable sample pre-processing/separation/purification/amplification steps that could improve selectivity and the overall signal-to-noise ratio. Three device types are reviewed here: (i) bulk acoustic wave sensors, (ii) surface acoustic wave sensors, and (iii) micro/nano-electromechanical system (MEMS/NEMS) sensors. PMID:27365040

  4. Acoustic emission

    International Nuclear Information System (INIS)

    This paper is related to our activities on acoustic emission (A.E.). The work is made with different materials: metals and fibre reinforced plastics. At present, acoustic emission transducers are being developed for low and high temperature. A test to detect electrical discharges in electrical transformers was performed. Our experience in industrial tests to detect cracks or failures in tanks or tubes is also described. The use of A.E. for leak detection is considered. Works on pattern recognition of A.E. signals are also being performed. (Author)

  5. Capping off installation

    CERN Multimedia

    2006-01-01

    Installation of the cathode strip chambers for the muon system on the CMS positive endcap has been completed. Technicians install one of the last muon system cathode strip chambers on the CMS positive endcap. Like successfully putting together the pieces of a giant puzzle, installation of the muon system cathode strip chambers on one of the CMS endcaps has been completed. Total installation of the cathode strip chambers (CSC) is now 91 percent complete; only one ring of chambers needs to be mounted on the remaining endcap to finish installation of the entire system. To guarantee a good fit for the 468 total endcap muon system CSCs, physicists and engineers from the collaboration spent about 10 years carefully planning the design. The endcap muon system's cables, boxes, pipes and other parts were designed and integrated using a 3D computerized model. 'It took a long time to do all the computer modelling, but in the long run it saved us an enormous amount of time because it meant that everything fit together,...

  6. A prototype device for acoustic neutrino detection in Lake Baikal

    CERN Document Server

    Budnev, N M

    2007-01-01

    In April 2006, a 4-channel acoustic antenna has been put in long-term operation on Lake Baikal. The detector was installed at a depth of about 100 m on the instrumentation string of Baikal Neutrino Telescope NT200+. This detector may be regarded as a prototype of a subunit for a future underwater acoustic neutrino telescope. We describe the design of acoustic detector and present first results obtained from data analysis.

  7. Installation of the LHC transfer lines begins

    CERN Multimedia

    Patrice Loïez

    2003-01-01

    The first of 700 magnets has been installed in one of the two transfer tunnels built to transfer the SPS beam into the LHC. The start of this first installation phase of the LHC transfer lines provides the opportunity to launch a new and highly original modular system for transporting and installing all kinds of magnets in very narrow tunnels. The system is based on very compact bogies, up to four of which can be coupled together to form a convoy. The wheels are fitted with individual motors enabling them to swivel through an angle of 90° and the convoy to move laterally. In this way the magnet is delivered directly to its installation point, but beneath the beamline. It is then raised into its final position in the beamline using air cushions, which form an integrated part of the transport system. Here we see the transport vehicle alongside the magnet supports. Visible in the background is the first magnet in place.

  8. Python Introduction and Installation

    Directory of Open Access Journals (Sweden)

    William J. Turkel

    2012-07-01

    Full Text Available This first lesson in our section on dealing with Online Sources is designed to get you and your computer set up to start programming. We will focus on installing the relevant software – all free and reputable – and finally we will help you to get your toes wet with some simple programming that provides immediate results. In this opening module you will install the Python programming language, the Beautiful Soup HTML/XML parser, and a text editor. Screencaps provided here come from Komodo Edit, but you can use any text editor capable of working with Python. Here’s a list of other options: Python Editors. Once everything is installed, you will write your first programs, “Hello World” in Python and HTML.

  9. Logistics of LEP installation

    International Nuclear Information System (INIS)

    The size of the LEP project, coupled with the tight construction schedules, calls for organized planning, logistics, monitoring and control. This is being carried out at present using tools such as ORACLE the Relational Database Management System, running on a VAX cluster for data storage and transfer, micro-computers for on-site follow-up, and PC's running Professional ORACLE, DOS and XENIX linked to a communications network to receive data feedback concerning transport and handling means. Following over 2 years of installations, this paper presents the methods used for the logistics of installation and their results

  10. Electrical installations technology

    CERN Document Server

    Whitfield, J F

    1968-01-01

    Electrical Installations Technology covers the syllabus of the City and Guilds of London Institute course No. 51, the "Electricians B Certificate”. This book is composed of 15 chapters that deal with basic electrical science and electrical installations. The introductory chapters discuss the fundamentals and basic electrical principles, including the concept of mechanics, heat, magnetic fields, electric currents, power, and energy. These chapters also explore the atomic theory of electric current and the electric circuit, conductors, and insulators. The subsequent chapter focuses on the chemis

  11. Electrical installation technology

    CERN Document Server

    Neidle, Michael

    1982-01-01

    Electrical Installation Technology, Third Edition covers the wide range of subjects that come under the headings of electrical science, installations, and regulations. The book discusses electromagnetism; inductance; static electricity; d.c. circuits; voltage drop and current rating; distribution; and wiring techniques. The text also describes o.c. motors and generators; a.c. motors, transformers; power-factor improvement; earthing and earth-leakage protection; testing; illumination; and the general principles of temperature and heat. Communication systems and equipment; electronics; and site

  12. Python Introduction and Installation

    OpenAIRE

    William J. Turkel; Adam Crymble

    2012-01-01

    This first lesson in our section on dealing with Online Sources is designed to get you and your computer set up to start programming. We will focus on installing the relevant software – all free and reputable – and finally we will help you to get your toes wet with some simple programming that provides immediate results. In this opening module you will install the Python programming language, the Beautiful Soup HTML/XML parser, and a text editor. Screencaps provided here come from Komodo ...

  13. Detection and tracking of drones using advanced acoustic cameras

    Science.gov (United States)

    Busset, Joël.; Perrodin, Florian; Wellig, Peter; Ott, Beat; Heutschi, Kurt; Rühl, Torben; Nussbaumer, Thomas

    2015-10-01

    Recent events of drones flying over city centers, official buildings and nuclear installations stressed the growing threat of uncontrolled drone proliferation and the lack of real countermeasure. Indeed, detecting and tracking them can be difficult with traditional techniques. A system to acoustically detect and track small moving objects, such as drones or ground robots, using acoustic cameras is presented. The described sensor, is completely passive, and composed of a 120-element microphone array and a video camera. The acoustic imaging algorithm determines in real-time the sound power level coming from all directions, using the phase of the sound signals. A tracking algorithm is then able to follow the sound sources. Additionally, a beamforming algorithm selectively extracts the sound coming from each tracked sound source. This extracted sound signal can be used to identify sound signatures and determine the type of object. The described techniques can detect and track any object that produces noise (engines, propellers, tires, etc). It is a good complementary approach to more traditional techniques such as (i) optical and infrared cameras, for which the object may only represent few pixels and may be hidden by the blooming of a bright background, and (ii) radar or other echo-localization techniques, suffering from the weakness of the echo signal coming back to the sensor. The distance of detection depends on the type (frequency range) and volume of the noise emitted by the object, and on the background noise of the environment. Detection range and resilience to background noise were tested in both, laboratory environments and outdoor conditions. It was determined that drones can be tracked up to 160 to 250 meters, depending on their type. Speech extraction was also experimentally investigated: the speech signal of a person being 80 to 100 meters away can be captured with acceptable speech intelligibility.

  14. CALCULATION OF ACOUSTIC EFFICIENCY OF PORTABLE ACOUSTIC SCREEN

    Directory of Open Access Journals (Sweden)

    Aleksandr Skvortsov

    2016-03-01

    Full Text Available The research of influence of life environment adverse factors on physical development and health of population is an actual problem of ecology. The aspects of the most actual problems of the modern world, namely environmental industrial noise pollution are considered in the article. Industrial facilities everywhere have noisy equipment. Noise is a significant factors of negative influenceon people and environment. Combined effects of noise and of other physical pollutions on people may cause amplification of their negative impact. If the noise pollution level from the object in a residential area exceeds the permissible levels (MPL, noise protection measures can be initiated. Today, the most common design decisions for noise protection are sound absorbing construction, noise screens and barriers, acousting housings, soundproff cabins. Many of them are popular, others are less known. The article deals with one of the most wide spread means of noise protection – a portable acoustic screen. The aim of the research is to determine the efficiency of portable acoustic screens. It is shown that the installation of such structures can reduce the average value of the sound level. The authors analyzed acoustic screens as device to reduce noise pollution. The authors offer a potable acoustic screen differing from the used easyness, mobility, minimum price and good sound protective properties. Effectiveness, a sound absorption coefficient and sound conductivity coefficient of a portable acoustic screen are evaluated. The descriptions of the algorithm calculations and the combination of technical solutions have practical originality. The results of the research demonstrate the advantages of the proposed solutions for reducing noise levels in the agro-industrial complex.

  15. Installing the ALICE detector

    CERN Multimedia

    Maximilien Brice

    2006-01-01

    The huge iron yoke in the cavern at Point 2 in the LHC tunnel is prepared for the installation of the ALICE experiment. The yoke is being reused from the previous L3 experiment that was located at the same point during the LEP project from 1989 to 2000. ALICE will be inserted piece by piece into the cradle where it will be used to study collisions between two beams of lead ions.

  16. Removing Background Noise with Phased Array Signal Processing

    Science.gov (United States)

    Podboy, Gary; Stephens, David

    2015-01-01

    Preliminary results are presented from a test conducted to determine how well microphone phased array processing software could pull an acoustic signal out of background noise. The array consisted of 24 microphones in an aerodynamic fairing designed to be mounted in-flow. The processing was conducted using Functional Beam forming software developed by Optinav combined with cross spectral matrix subtraction. The test was conducted in the free-jet of the Nozzle Acoustic Test Rig at NASA GRC. The background noise was produced by the interaction of the free-jet flow with the solid surfaces in the flow. The acoustic signals were produced by acoustic drivers. The results show that the phased array processing was able to pull the acoustic signal out of the background noise provided the signal was no more than 20 dB below the background noise level measured using a conventional single microphone equipped with an aerodynamic forebody.

  17. Decommissioning of offshore installations

    Energy Technology Data Exchange (ETDEWEB)

    Oeen, Sigrun; Iversen, Per Erik; Stokke, Reidunn; Nielsen, Frantz; Henriksen, Thor; Natvig, Henning; Dretvik, Oeystein; Martinsen, Finn; Bakke, Gunnstein

    2010-07-01

    New legislation on the handling and storage of radioactive substances came into force 1 January 2011. This version of the report is updated to reflect this new regulation and will therefore in some chapters differ from the Norwegian version (see NEI-NO--1660). The Ministry of the Environment commissioned the Climate and Pollution Agency to examine the environmental impacts associated with the decommissioning of offshore installations (demolition and recycling). This has involved an assessment of the volumes and types of waste material and of decommissioning capacity in Norway now and in the future. This report also presents proposals for measures and instruments to address environmental and other concerns that arise in connection with the decommissioning of offshore installations. At present, Norway has four decommissioning facilities for offshore installations, three of which are currently involved in decommissioning projects. Waste treatment plants of this kind are required to hold permits under the Pollution Control Act. The permit system allows the pollution control authority to tailor the requirements in a specific permit by evaluating conditions and limits for releases of pollutants on a case-to-case basis, and the Act also provides for requirements to be tightened up in line with the development of best available techniques (BAT). The environmental risks posed by decommissioning facilities are much the same as those from process industries and other waste treatment plants that are regulated by means of individual permits. Strict requirements are intended to ensure that environmental and health concerns are taken into account. The review of the four Norwegian decommissioning facilities in connection with this report shows that the degree to which requirements need to be tightened up varies from one facility to another. The permit for the Vats yard is newest and contains the strictest conditions. The Climate and Pollution Agency recommends a number of measures

  18. Nuclear installations sites safety

    International Nuclear Information System (INIS)

    This report is divided into ten parts bearing: 1 Safety analysis procedures for Basis Nuclear Installations sites (BNI) in France 2 Site safety for BNI in France 3 Industrial and transport activities risks for BNI in France 4 Demographic characteristics near BNI sites in France 5 Meteorologic characteristics of BNI sites in France 6 Geological aspects near the BNI sites in France 7 Seismic studies for BNI sites in France 8 Hydrogeological aspects near BNI sites in France 9 Hydrological aspects near BNI sites in France 10 Ecological and radioecological studies of BNI sites in France

  19. Wireless installation standard

    International Nuclear Information System (INIS)

    This is divided six parts which are radio regulation law on securing of radio resource, use of radio resource, protection of radio resource, radio regulation enforcement ordinance with securing, distribution and assignment of radio regulation, radio regulation enforcement regulation on utility of radio resource and technical qualification examination, a wireless installation regulation of technique standard and safety facility standard, radio regulation such as certification regulation of information communicative machines and regulation of radio station on compliance of signal security, radio equipment in radio station, standard frequency station and emergency communication.

  20. CNGS Reflector installed

    CERN Multimedia

    2006-01-01

    A major component that will help target the CNGS neutrino beam for its 732km journey through the earth's crust, from CERN to the Gran Sasso laboratory in Italy, has been installed in its final position. The transport of the huge magnetic horn reflector through the CNGS access gallery. A team from CNGS and TS/IC, and the contractors DBS, transported the magnetic horn reflector on 5th December, in a carefully conducted operation that took just under two hours. The reflector is 7m long, 1.6m in diameter and 1.6 tonnes in weight. With only a matter of centimetres to spare on either side, the reflector was transported through the CNGS access gallery, before being installed in the experiment's target chamber. The larger of two magnetic horns, the reflector will help refocus sprays of high energy pions and kaons emitted after a 0.5MW stream of protons from the Super Proton Synchrotron (SPS) strikes nucleons in a graphite target. The horns are toroidal magnetic lenses and work with high pulsed currents: 150 kA f...

  1. Energy-efficient photovoltaic installation

    International Nuclear Information System (INIS)

    In this paper R&D basics for photovoltaic installation development are presented. Efficiency of energy conversion process depending on the azimuth and zenith angles of the installation's rotation is investigated. Recommendations on the installations' class design are given. Technical and economic assessments of the proposed solutions are made

  2. The installation of the Gerda muon veto

    International Nuclear Information System (INIS)

    The Gerda collaboration aims to determine the half-life of the neutrinoless double beta decay (0νββ) of 76Ge. Due to the long half life of this decay (T1/2>1025y), the experimental background must be reduced at least to a level of 10-3 counts/(kg.y.keV) in the region around Qββ. Cosmic muons induce a part of this dangerous background and must be detected in order to generate a veto signal. Part of this veto system is a water Cherenkov detector surrounding the cryostat which contains the germanium crystals. The Cherenkov veto was simulated, designed and installed by the astroparticle group in Tuebingen. The veto consists of 66 photomultiplier (8 inch), a calibration and monitoring system, reflective VM2000 foil and the control electronics. In this talk the veto, its design and accomplished installation is presented.

  3. The installation of the Gerda muon veto

    Energy Technology Data Exchange (ETDEWEB)

    Freund, Kai; Dietrich, Dennis; Grabmayr, Peter; Hegai, Alexander; Jochum, Josef; Knapp, Markus; Meierhofer, Georg; Ritter, Florian [Kepler Center for Astro and Particle Physics, Eberhard Karls Universitaet Tuebingen (Germany)

    2010-07-01

    The Gerda collaboration aims to determine the half-life of the neutrinoless double beta decay (0{nu}{beta}{beta}) of {sup 76}Ge. Due to the long half life of this decay (T{sub 1/2}>10{sup 25}y), the experimental background must be reduced at least to a level of 10{sup -3} counts/(kg.y.keV) in the region around Q{sub {beta}}{sub {beta}}. Cosmic muons induce a part of this dangerous background and must be detected in order to generate a veto signal. Part of this veto system is a water Cherenkov detector surrounding the cryostat which contains the germanium crystals. The Cherenkov veto was simulated, designed and installed by the astroparticle group in Tuebingen. The veto consists of 66 photomultiplier (8 inch), a calibration and monitoring system, reflective VM2000 foil and the control electronics. In this talk the veto, its design and accomplished installation is presented.

  4. Decommissioning of offshore installations

    Energy Technology Data Exchange (ETDEWEB)

    Oeen, Sigrun; Iversen, Per Erik; Stokke, Reidunn; Nielsen, Frantz; Henriksen, Thor; Natvig, Henning; Dretvik, Oeystein; Martinsen, Finn; Bakke, Gunnstein

    2010-07-01

    New legislation on the handling and storage of radioactive substances came into force 1 January 2011. This version of the report is updated to reflect this new regulation and will therefore in some chapters differ from the Norwegian version (see NEI-NO--1660). The Ministry of the Environment commissioned the Climate and Pollution Agency to examine the environmental impacts associated with the decommissioning of offshore installations (demolition and recycling). This has involved an assessment of the volumes and types of waste material and of decommissioning capacity in Norway now and in the future. This report also presents proposals for measures and instruments to address environmental and other concerns that arise in connection with the decommissioning of offshore installations. At present, Norway has four decommissioning facilities for offshore installations, three of which are currently involved in decommissioning projects. Waste treatment plants of this kind are required to hold permits under the Pollution Control Act. The permit system allows the pollution control authority to tailor the requirements in a specific permit by evaluating conditions and limits for releases of pollutants on a case-to-case basis, and the Act also provides for requirements to be tightened up in line with the development of best available techniques (BAT). The environmental risks posed by decommissioning facilities are much the same as those from process industries and other waste treatment plants that are regulated by means of individual permits. Strict requirements are intended to ensure that environmental and health concerns are taken into account. The review of the four Norwegian decommissioning facilities in connection with this report shows that the degree to which requirements need to be tightened up varies from one facility to another. The permit for the Vats yard is newest and contains the strictest conditions. The Climate and Pollution Agency recommends a number of measures

  5. High transmission acoustic focusing by impedance-matched acoustic meta-surfaces

    KAUST Repository

    Al Jahdali, Rasha

    2016-01-19

    Impedance is an important issue in the design of acoustic lenses because mismatched impedance is detrimental to real focusing applications. Here, we report two designs of acoustic lenses that focus acoustic waves in water and air, respectively. They are tailored by acoustic meta-surfaces, which are rigid thin plates decorated with periodically distributed sub-wavelength slits. Their respective building blocks are constructed from the coiling-up spaces in water and the layered structures in air. Analytic analysis based on coupled-mode theory and transfer matrix reveals that the impedances of the lenses are matched to those of the background media. With these impedance-matched acoustic lenses, we demonstrate the acoustic focusing effect by finite-element simulations.

  6. Study on Acoustic Catheter of Boiler Tube Leakage Monitoring Systems

    Science.gov (United States)

    Lv, Yongxing; Feng, Qiang

    Boiler tube leakage is the major reason of affecting the safe operation of the unit now, there are 3 methods of the "four tube" leakage detection: Traditional method, filtering method and acoustic spectrum analysis, acoustic spectrum analysis is the common method, but this method have low sensitivity and the sensor damage easily. Therewith, designed the special acoustic catheter with acoustic resonance cavity type, proved by experiments, the acoustic catheter with acoustic resonance cavity type can enhance leakage sound, can accurately extract leakage signals, has high sensitivity, and can avoid the effect of sensor by fire and hot-gas when the furnace is in positive pressure situation, reduce the installation and maintenance costs of the boiler tube leakage monitor system.

  7. Management of the Acoustic Characteristics of Jet Streams

    Directory of Open Access Journals (Sweden)

    Bulat Pavel Viktorovich

    2014-07-01

    Full Text Available The objects of research are devices, which generate and suppress the acoustic and wave pressure oscillations. Purpose of the study is the classification of oscillations generating devices, description of the physical principles of acoustic waves generation. The schemes of the most common sound generators-whistles are discussed. The gas-jet sound generators are described separately. It is shown that a simple cylindrical head at the supersonic nozzle can both enhance the acoustic emission and serve as an effective silencer. The comparison of acoustic emission of a supersonic jet and a jet, flowing into a cylindrical head is given. The results presented in the study can be recommended by the developers of whistles, sirens, other acoustic generators, installations for thermo-acoustic hardening metals, metallurgical blast devices.

  8. Unexpectedly Large Surface Gravities for Acoustic Horizons?

    CERN Document Server

    Liberati, S; Visser, M; Liberati, Stefano; Sonego, Sebastiano; Visser, Matt

    2000-01-01

    Acoustic black holes are fluid dynamic analogs of general relativistic black holes, wherein the behaviour of sound waves in a moving fluid acts as an analog for scalar fields propagating in a gravitational background. Acoustic horizons possess many of the properties more normally associated with the event horizons of general relativity, up to and including Hawking radiation. They have received much attention because it would seem to be much easier to experimentally create an acoustic horizon than to create an event horizon. We wish to point out some potential difficulties (and opportunities) in actually setting up an experiment that possesses an acoustic horizon. We show that in zero-viscosity, stationary fluid flow with generic boundary conditions, the creation of an acoustic horizon is accompanied by a formally infinite ``surface gravity'', and a formally infinite Hawking flux. Only by applying a suitable non-constant external body force, and for very specific boundary conditions on the flow, can these quan...

  9. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available Educational Video Home What is an AN What is an Acoustic Neuroma? Identifying an AN Symptoms Acoustic Neuroma Keywords Educational Video ... for pre- and post-treatment acoustic neuroma patients. Home What is an AN What is an Acoustic ...

  10. Acoustic cryocooler

    Science.gov (United States)

    Swift, Gregory W.; Martin, Richard A.; Radenbaugh, Ray

    1990-01-01

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

  11. Acoustic telemetry.

    Energy Technology Data Exchange (ETDEWEB)

    Drumheller, Douglas Schaeffer; Kuszmaul, Scott S.

    2003-08-01

    Broadcasting messages through the earth is a daunting task. Indeed, broadcasting a normal telephone conversion through the earth by wireless means is impossible with todays technology. Most of us don't care, but some do. Industries that drill into the earth need wireless communication to broadcast navigation parameters. This allows them to steer their drill bits. They also need information about the natural formation that they are drilling. Measurements of parameters such as pressure, temperature, and gamma radiation levels can tell them if they have found a valuable resource such as a geothermal reservoir or a stratum bearing natural gas. Wireless communication methods are available to the drilling industry. Information is broadcast via either pressure waves in the drilling fluid or electromagnetic waves in the earth and well tubing. Data transmission can only travel one way at rates around a few baud. Given that normal Internet telephone modems operate near 20,000 baud, these data rates are truly very slow. Moreover, communication is often interrupted or permanently blocked by drilling conditions or natural formation properties. Here we describe a tool that communicates with stress waves traveling through the steel drill pipe and production tubing in the well. It's based on an old idea called Acoustic Telemetry. But what we present here is more than an idea. This tool exists, it's drilled several wells, and it works. Currently, it's the first and only acoustic telemetry tool that can withstand the drilling environment. It broadcasts one way over a limited range at much faster rates than existing methods, but we also know how build a system that can communicate both up and down wells of indefinite length.

  12. Development and installation of the GERDA experiment

    International Nuclear Information System (INIS)

    The progress in the development of the GERDA (GErmanium Detector Array) experiment is presented. The goal of the experiment is the search for neutrinoless double beta decay of 76Ge with considerable reduction of background in comparison with predecessor experiments. GERDA will operate bare germanium semiconductor detectors (enriched in 76Ge) submerged in high purity liquid argon supplemented by a water shield. The experimental set up is currently under construction in the underground facility of LNGS, Italy. The results of various R and D efforts and the main steps of the GERDA set up design and installation are given as well as several novel methods for background reduction are described.

  13. Use of acoustic vortices in acoustic levitation

    DEFF Research Database (Denmark)

    Cutanda Henriquez, Vicente; Santillan, Arturo Orozco; Juhl, Peter Møller

    2009-01-01

    Acoustic fields are known to exert forces on the surfaces of objects. These forces are noticeable if the sound pressure is sufficiently high. Two phenomena where acoustic forces are relevant are: i) acoustic levitation, where strong standing waves can hold small objects at certain positions......, counterbalancing their weight, and ii) acoustic vortices, spinning sound fields that can impinge angular momentum and cause rotation of objects. In this contribution, both force-creating sound fields are studied by means of numerical simulations. The Boundary Element Method is employed to this end. The simulation...... of acoustical vortices uses an efficient numerical implementation based on the superposition of two orthogonal sound fields with a delay of 90° between them. It is shown that acoustic levitation and the use of acoustic vortices can be combined to manipulate objects in an efficient and controlled manner without...

  14. Acoustic dispersive prism

    OpenAIRE

    Hussein Esfahlani; Sami Karkar; Herve Lissek; 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 ...

  15. Transmission experiment by the simulated LMFBR model and propagation analysis of acoustic signals

    International Nuclear Information System (INIS)

    Acoustic transducers to detect a boiling of sodium may be installed in the upper structure and at the upper position of reactor vessel wall under constricted conditions. A set of the experiments of transmission of acoustic vibration to various points of the vessel was performed utilizing the half scale-hydraulic flow test facility simulating reactor vessel over the frequency range 20 kHz -- 100 kHz. Acoustic signals from an installed sound source in the core were measured at each point by both hydrophones in the vessel and vibration pickups on the vessel wall. In these experiments transmission of signals to each point of detectors were clearly observed to background noise level. These data have been summarized in terms of the transmission loss and furthermore are compared with background noise level of flow to estimate the feasibility of detection of sodium boiling sound. The ratio of signal to noise was obtained to be about 13 dB by hydrophone in the upper structure, 8 dB by accelerometer and 16 dB by AE-sensor at the upper position on the vessel in experiments used the simulation model. Sound waves emanated due to sodium boiling also propagate along the wall of the vessel may be predicted theoretically. The result of analysis suggests a capability of detection at the upper position of the reactor vessel wall. Leaky Lamb waves of the first symmetric (L1) and of the antisymmetric (F1) mode and shear horizontal wave (SH) have been derived in light of the attenuation due to coupling to liquid sodium as the traveling modes over the frequency range 10 kHz -- 100 kHz up to 50 mm in thickness of the vessel wall. Leaky Lamb wave (L1) and (SH) mode have been proposed theoretically on the some assumption to be most available to detect the boiling sound of sodium propagating along the vessel wall. (author)

  16. Measurement of acoustical characteristics of mosques in Saudi Arabia

    Science.gov (United States)

    Abdou, Adel A.

    2003-03-01

    The study of mosque acoustics, with regard to acoustical characteristics, sound quality for speech intelligibility, and other applicable acoustic criteria, has been largely neglected. In this study a background as to why mosques are designed as they are and how mosque design is influenced by worship considerations is given. In the study the acoustical characteristics of typically constructed contemporary mosques in Saudi Arabia have been investigated, employing a well-known impulse response. Extensive field measurements were taken in 21 representative mosques of different sizes and architectural features in order to characterize their acoustical quality and to identify the impact of air conditioning, ceiling fans, and sound reinforcement systems on their acoustics. Objective room-acoustic indicators such as reverberation time (RT) and clarity (C50) were measured. Background noise (BN) was assessed with and without the operation of air conditioning and fans. The speech transmission index (STI) was also evaluated with and without the operation of existing sound reinforcement systems. The existence of acoustical deficiencies was confirmed and quantified. The study, in addition to describing mosque acoustics, compares design goals to results obtained in practice and suggests acoustical target values for mosque design. The results show that acoustical quality in the investigated mosques deviates from optimum conditions when unoccupied, but is much better in the occupied condition.

  17. ROS Installation and Commissioning

    CERN Multimedia

    Gorini, B

    The ATLAS Readout group (a sub-group of TDAQ) has now completed the installation and commissioning of all of the Readout System (ROS) units. Event data from ATLAS is initially handled by detector specific hardware and software, but following a Level 1 Accept the data passes from the detector specific Readout Drivers (RODs) to the ROS, the first stage of the central ATLAS DAQ. Within the final ATLAS TDAQ system the ROS stores the data and on request makes it available to the Level 2 Trigger (L2) processors and to the Event Builder (EB) as required. The ROS is implemented as a large number of PCs housing custom built cards (ROBINs) and running custom multi-threaded software. Each ROBIN card (shown below) contains buffer memories to store the data, plus a field programmable gate array ( FPGA ) and an embedded PowerPC processor for management of the memories and data requests, and is implemented as a 64-bit 66 MHz PCI card. Both the software and the ROBIN cards have been designed and developed by the Readout g...

  18. Acoustic flowmeters: Their applications in hydraulics

    Science.gov (United States)

    Nitzsche, Ulf

    Flowmeter installations for viscous and high hydrostatic pressure media are developed. Their usability is considered for characteristic measuring tasks in the field of oil hydraulics. The properties of flow sensors are evaluated by system analysis. Acoustic measuring systems are preferred. Two ultrasonic flowmeters are realized. Simulation models, installation with piezoceramic material parameters, and sound visualization support these developments. A computer aided hydraulic test stand is developed in order to detect the measuring characteristics of this system. Flowmeter applications are shown using the identification of the static and dynamic parameters of an electrohydraulic pilot valve.

  19. Integrating Conduit with Windows Installer

    OpenAIRE

    2009-01-01

    Conduit is a multi-platform distribution and deployment system originally created by Arve Knudsen. Conduit sets out to streamline the installation process of software, and assist in the installation of software that might otherwise be quite complex to install manually. The system is written in the Python programming language and consists of a generic design which is implemented on multiple operating through several Python modules. The Conduit software suit consists of Python...

  20. Installing Python Modules with pip

    OpenAIRE

    Fred Gibbs

    2013-01-01

    This lesson shows you how to download and install Python modules. There are many ways to install external modules, but for the purposes of this lesson, we’re going to use a program called pip. As of Python 2.7.9 and newer, pip is installed by default. This tutorial will be helpful for anyone using older versions of Python (which are still quite common).

  1. Responsive acoustic surfaces

    DEFF Research Database (Denmark)

    Peters, Brady; Tamke, Martin; Nielsen, Stig Anton;

    2011-01-01

    Acoustic performance is defined by the parameter of reverberation time; however, this does not capture the acoustic experience in some types of open plan spaces. As many working and learning activities now take place in open plan spaces, it is important to be able to understand and design...... for the acoustic conditions of these spaces. This paper describes an experimental research project that studied the design processes necessary to design for sound. A responsive acoustic surface was designed, fabricated and tested. This acoustic surface was designed to create specific sonic effects. The design...... was simulated using custom integrated acoustic software and also using Odeon acoustic analysis software. The research demonstrates a method for designing space- and sound-defining surfaces, defines the concept of acoustic subspace, and suggests some new parameters for defining acoustic subspaces....

  2. Springer Handbook of Acoustics

    CERN Document Server

    Rossing, Thomas D

    2007-01-01

    Acoustics, the science of sound, has developed into a broad interdisciplinary field encompassing the academic disciplines of physics, engineering, psychology, speech, audiology, music, architecture, physiology, neuroscience, and others. The Springer Handbook of Acoustics is an unparalleled modern handbook reflecting this richly interdisciplinary nature edited by one of the acknowledged masters in the field, Thomas Rossing. Researchers and students benefit from the comprehensive contents spanning: animal acoustics including infrasound and ultrasound, environmental noise control, music and human speech and singing, physiological and psychological acoustics, architectural acoustics, physical and engineering acoustics, signal processing, medical acoustics, and ocean acoustics. This handbook reviews the most important areas of acoustics, with emphasis on current research. The authors of the various chapters are all experts in their fields. Each chapter is richly illustrated with figures and tables. The latest rese...

  3. Acoustic Spatiality

    Directory of Open Access Journals (Sweden)

    Brandon LaBelle

    2012-06-01

    Full Text Available Experiences of listening can be appreciated as intensely relational, bringing us into contact with surrounding events, bodies and things. Given that sound propagates and expands outwardly, as a set of oscillations from a particular source, listening carries with it a sensual intensity, whereby auditory phenomena deliver intrusive and disruptive as well as soothing and assuring experiences. The physicality characteristic of sound suggests a deeply impressionistic, locational "knowledge structure" – that is, the ways in which listening affords processes of exchange, of being in the world, and from which we extend ourselves. Sound, as physical energy reflecting and absorbing into the materiality around us, and even one's self, provides a rich platform for understanding place and emplacement. Sound is always already a trace of location.Such features of auditory experience give suggestion for what I may call an acoustical paradigm – how sound sets in motion not only the material world but also the flows of the imagination, lending to forces of signification and social structure, and figuring us in relation to each other. The relationality of sound brings us into a steady web of interferences, each of which announces the promise or problematic of being somewhere.

  4. Acoustic Neurinomas

    Directory of Open Access Journals (Sweden)

    Mohammad Faraji Rad

    2011-01-01

    Full Text Available Acoustic neuromas (AN are schwann cell-derived tumors that commonly arise from the vestibular portion of the eighth cranial nerve also known as vestibular schwannoma(VS causes unilateral hearing loss, tinnitus, vertigo and unsteadiness. In many cases, the tumor size may remain unchanged for many years following diagnosis, which is typically made by MRI. In the majority of cases the tumor is small, leaving the clinician and patient with the options of either serial scanning or active treatment by gamma knife radiosurgery (GKR or microneurosurgery. Despite the vast number of published treatment reports, comparative studies are few. The predominant clinical endpoints of AN treatment include tumor control, facial nerve function and hearing preservation. Less focus has been put on symptom relief and health-related quality of life (QOL. It is uncertain if treating a small tumor leaves the patient with a better chance of obtaining relief from future hearing loss, vertigo or tinnitus than by observing it without treatment.   In this paper we review the literature for the natural course, the treatment alternatives and the results of AN. Finally, we present our experience with a management strategy applied for more than 30 years.

  5. Acoustic Resonance Frequency Elimination Device for Safety Relief Valves

    Energy Technology Data Exchange (ETDEWEB)

    Redmond, J.

    2014-07-01

    Industry experience has shown that Safety Relief Valves (SRVs) and Steam Dryers installed in Boiling Water Reactors (BWRs) experience vibration induced degradation and failures caused by acoustic resonance vibration of the main steam lines, resulting in decreased reliability and potential safety issues. The resonance is caused by vortex shedding from the standpipe inlet and acoustic standing waves in the standpipe, occurring when the two frequencies match. (Author)

  6. Detection of steam leaks into sodium in fast reactor steam generators by acoustic techniques - An overview of Indian programme

    International Nuclear Information System (INIS)

    Realising the potential of acoustic leak detection technique, an experimental programme was initiated a few years back at Indira Gandhi Centre for Atomic Research (IGCAR) to develop this technique. The first phase of this programme consists of experiments to measure background noise characteristics on the steam generator modules of the 40 MW (thermal) Fast Breeder Test Reactor (FBTR) at Kalpakkam and experiments to establish leak noise characteristics with the help of a leak simulation set up. By subjecting the measured data from these experiments to signal analysis techniques, a criterion for acoustic leak detection for FBTR steam generator will be evolved. Second phase of this programme will be devoted to developing an acoustic leak detection system suitable for installation in the 500 MWe Prototype Fast Breeder Reactor (PFBR). This paper discusses the first phase of the experimental programme, results obtained from measurements carried out on FBTR steam generators and results obtained from leak simulation experiments. Acoustic leak detection system being considered for PFBR is also briefly described. 4 refs, 8 figs, 1 tab

  7. Acoustic source for generating an acoustic beam

    Energy Technology Data Exchange (ETDEWEB)

    Vu, Cung Khac; Sinha, Dipen N.; Pantea, Cristian

    2016-05-31

    An acoustic source for generating an acoustic beam includes a housing; a plurality of spaced apart piezo-electric layers disposed within the housing; and a non-linear medium filling between the plurality of layers. Each of the plurality of piezoelectric layers is configured to generate an acoustic wave. The non-linear medium and the plurality of piezo-electric material layers have a matching impedance so as to enhance a transmission of the acoustic wave generated by each of plurality of layers through the remaining plurality of layers.

  8. Canonical Acoustics and Its Application to Surface Acoustic Wave on Acoustic Metamaterials

    Science.gov (United States)

    Shen, Jian Qi

    2016-08-01

    In a conventional formalism of acoustics, acoustic pressure p and velocity field u are used for characterizing acoustic waves propagating inside elastic/acoustic materials. We shall treat some fundamental problems relevant to acoustic wave propagation alternatively by using canonical acoustics (a more concise and compact formalism of acoustic dynamics), in which an acoustic scalar potential and an acoustic vector potential (Φ ,V), instead of the conventional acoustic field quantities such as acoustic pressure and velocity field (p,u) for characterizing acoustic waves, have been defined as the fundamental variables. The canonical formalism of the acoustic energy-momentum tensor is derived in terms of the acoustic potentials. Both the acoustic Hamiltonian density and the acoustic Lagrangian density have been defined, and based on this formulation, the acoustic wave quantization in a fluid is also developed. Such a formalism of acoustic potentials is employed to the problem of negative-mass-density assisted surface acoustic wave that is a highly localized surface bound state (an eigenstate of the acoustic wave equations). Since such a surface acoustic wave can be strongly confined to an interface between an acoustic metamaterial (e.g., fluid-solid composite structures with a negative dynamical mass density) and an ordinary material (with a positive mass density), it will give rise to an effect of acoustic field enhancement on the acoustic interface, and would have potential applications in acoustic device design for acoustic wave control.

  9. Integrated installation for offshore wind turbines

    Energy Technology Data Exchange (ETDEWEB)

    Way, J.; Bowerman, H.

    2003-07-01

    A project to investigate the feasibility of integrating the offshore installation of foundation, turbine and tower for offshore wind turbines into one operation is described. Three separate objectives are listed. They are: (1) Telescopic tower study - reversible process incorporating lift and lock mechanisms; (2) Transportation study - technical and economic feasibility of transporting and installing a wind turbine unit via a standard barge with minimal conversion and (3) Self-burial system study - to demonstrate the feasibility of self burial of a slab foundation via controlled jetting beneath the slab. The background to the study and the proposed concepts are discussed. The work carried out to date and the costs are reported together with the findings. Recommendations for future work are listed. The work was carried out by Corus UK Ltd and is managed by Future Energy Solutions for the DTI.

  10. LV21 Lightship collage installation

    OpenAIRE

    Bennett, Evelyn; Rutter, Christopher

    2014-01-01

    The 4th iteration of an ongoing site responsive collage installation series, which had previous incarnations in Berlin, Zurich and Herne Bay. Imagery taken from the previous location is digitally and manually manipulated and used in the new installation which gradually accretes new imagery and forms as well as geographical and historical resonances.

  11. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... ANA Annual Reports Acoustic Neuroma Legacy Society Programs & Services Join/Renew Ways to Give ANA Discussion Forum ... ANA Annual Reports Acoustic Neuroma Legacy Society Programs & Services Search ANAUSA.org Connect with us! Educational Video ...

  12. Atlantic Herring Acoustic Surveys

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC Advanced Sampling Technologies Research Group conducts annual fisheries acoustic surveys using state-of-the-art acoustic, midwater trawling, and...

  13. Cystic acoustic neuromas

    OpenAIRE

    Chitkara, Naveen; Chanda, Rakesh; Yadav, S. P. S.; N.K. Sharma

    2002-01-01

    Predominantly cystic acoustic neuromas are rare and they usually present with clinical and radiological features different from their more common solid counterparts. Two cases of cystic acoustic neuromas are reported here.

  14. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... is ANA? Mission Statement Board of Directors ANA Staff Medical Advisory Board News ANA Annual Reports Acoustic ... is ANA? Mission Statement Board of Directors ANA Staff Medical Advisory Board News ANA Annual Reports Acoustic ...

  15. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... Watch and Wait Radiation Microsurgery Acoustic Neuroma Decision Tree Questions for Your Physician Questions to Ask Yourself ... Watch and Wait Radiation Microsurgery Acoustic Neuroma Decision Tree Questions for Your Physician Questions to Ask Yourself ...

  16. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... Resources Patient Surveys Related Links Clinical Trials.gov Health Care Insurance Toolkit Additional Resources ANA Public Webinars © 2016 Acoustic Neuroma Association Acoustic Neuroma Association ® • ...

  17. Tutorial on architectural acoustics

    Science.gov (United States)

    Shaw, Neil; Talaske, Rick; Bistafa, Sylvio

    2002-11-01

    This tutorial is intended to provide an overview of current knowledge and practice in architectural acoustics. Topics covered will include basic concepts and history, acoustics of small rooms (small rooms for speech such as classrooms and meeting rooms, music studios, small critical listening spaces such as home theatres) and the acoustics of large rooms (larger assembly halls, auditoria, and performance halls).

  18. Rhythm perturbations in acoustically paced treadmill walking after stroke

    NARCIS (Netherlands)

    Roerdink, Melvyn; Lamoth, Claudine J. C.; Van Kordelaar, Joost; Elich, Peter; Konijnenbelt, Manin; Kwakkel, Gert; Beek, Peter J.

    2009-01-01

    Background. In rehabilitation, acoustic rhythms are often used to improve gait after stroke. Acoustic cueing may enhance gait coordination by creating a stable coupling between heel strikes and metronome beats and provide a means to train the adaptability of gait coordination to environmental change

  19. Open Rotor Aeroacoustic Installation Effects for Conventional and Unconventional Airframes

    Science.gov (United States)

    Czech, Michael J.; Thomas, Russell H.

    2013-01-01

    As extensive experimental campaign was performed to study the aeroacoustic installation effects of an open rotor with respect to both a conventional tube and wing type airframe and an unconventional hybrid wing body airframe. The open rotor rig had two counter rotating rows of blades each with eight blades of a design originally flight tested in the 1980s. The aeroacoustic installation effects measured in an aeroacoustic wind tunnel included those from flow effects due to inflow distortion or wake interaction and acoustic propagation effects such as shielding and reflection. The objective of the test campaign was to quantify the installation effects for a wide range of parameters and configurations derived from the two airframe types. For the conventional airframe, the open rotor was positioned in increments in front of and then over the main wing and then in positions representative of tail mounted aircraft with a conventional tail, a T-tail and a U-tail. The interaction of the wake of the open rotor as well as acoustic scattering results in an increase of about 10 dB when the rotor is positioned in front of the main wing. When positioned over the main wing a substantial amount of noise reduction is obtained and this is also observed for tail-mounted installations with a large U-tail. For the hybrid wing body airframe, the open rotor was positioned over the airframe along the centerline as well as off-center representing a twin engine location. A primary result was the documentation of the noise reduction from shielding as a function of the location of the open rotor upstream of the trailing edge of the hybrid wing body. The effects from vertical surfaces and elevon deflection were also measured. Acoustic lining was specially designed and inserted flush with the elevon and airframe surface, the result was an additional reduction in open rotor noise propagating to the far field microphones. Even with the older blade design used, the experiment provided

  20. Acoustic elliptical cylindrical cloaks

    Institute of Scientific and Technical Information of China (English)

    Ma Hua; Qu Shao-Bo; Xu Zhuo; Wang Jia-Fu

    2009-01-01

    By making a comparison between the acoustic equations and the 2-dimensional (2D) Maxwell equations, we obtain the material parameter equations (MPE) for acoustic elliptical cylindrical cloaks. Both the theoretical results and the numerical results indicate that an elliptical cylindrical cloak can realize perfect acoustic invisibility when the spatial distributions of mass density and bulk modulus are exactly configured according to the proposed equations. The present work is the meaningful exploration of designing acoustic cloaks that are neither sphere nor circular cylinder in shape, and opens up possibilities for making complex and multiplex acoustic cloaks with simple models such as spheres, circular or elliptic cylinders.

  1. DAQ INSTALLATION IN USC COMPLETED

    CERN Multimedia

    A. Racz

    After one year of work at P5 in the underground control rooms (USC55-S1&S2), the DAQ installation in USC55 is completed. The first half of 2006 was dedicated to the DAQ infrastructures installation (private cable trays, rack equipment for a very dense cabling, connection to services i.e. water, power, network). The second half has been spent to install the custom made electronics (FRLs and FMMs) and place all the inter-rack cables/fibers connecting all sub-systems to central DAQ (more details are given in the internal pages). The installation has been carried out by DAQ group members, coming from the hardware and software side as well. The pictures show the very nice team spirit !

  2. Solar Installation Labor Market Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Friedman, B.; Jordan, P.; Carrese, J.

    2011-12-01

    The potential economic benefits of the growing renewable energy sector have led to increased federal, state, and local investments in solar industries, including federal grants for expanded workforce training for U.S. solar installers. However, there remain gaps in the data required to understand the size and composition of the workforce needed to meet the demand for solar power. Through primary research on the U.S. solar installation employer base, this report seeks to address that gap, improving policymakers and other solar stakeholders understanding of both the evolving needs of these employers and the economic opportunity associated with solar market development. Included are labor market data covering current U.S. employment, expected industry growth, and employer skill preferences for solar installation-related occupations. This study offers an in-depth look at the solar installation sectors. A study published by the Solar Foundation in October 2011 provides a census of labor data across the entire solar value chain.

  3. Evaluation of a reverberation enhancement system installed in a small multi purpose hall

    DEFF Research Database (Denmark)

    Gade, Anders Christian

    1997-01-01

    After design and installation of a reverberation enhancement system in new 400 seat multi purpose hall in Vejle, Denmark. room acoustic measurements and listening tests were performed in order to reveal the objective and subjective performance and limits of such a powerful tool for altering ''room...

  4. ACOUSTICAL STANDARDS NEWS.

    Science.gov (United States)

    Stremmel, Neil; Struck, Christopher J

    2016-07-01

    American National Standards (ANSI Standards) developed by Accredited Standards Committees S1, S2, S3, S3/SC 1, and S12 in the areas of acoustics, mechanical vibration and shock, bioacoustics, animal bioacoustics, and noise, respectively, are published by the Acoustical Society of America (ASA). In addition to these standards, ASA publishes a catalog of Acoustical American National Standards. To receive a copy of the latest Standards catalog, please contact Neil Stremmel.Comments are welcomed on all material in Acoustical Standards News.This Acoustical Standards News section in JASA, as well as the National Catalog of Acoustical Standards and other information on the Standards Program of the Acoustical Society of America, are available via the ASA home page: http://acousticalsociety.org. PMID:27475185

  5. Acoustic streaming in microchannels

    DEFF Research Database (Denmark)

    Tribler, Peter Muller

    , the acoustic streaming flow, and the forces on suspended microparticles. The work is motivated by the application of particle focusing by acoustic radiation forces in medical, environmental and food sciences. Here acoustic streaming is most often unwanted, because it limits the focusability of particles...... work. Based on first- and second-order perturbation theory, assuming small acoustic amplitudes, we derived the time-dependent governing equations under adiabatic conditions. The adiabatic first- and second-order equations are solved analytically for the acoustic field between two orthogonally......-of-the-art in the field. Furthermore, the analytical solution for the acoustic streaming in rectangular channels with arbitrary large height-to-width ratios is derived. This accommodates the analytical theory of acoustic streaming to applications within acoustofluidics....

  6. Installment options close to expiry

    Directory of Open Access Journals (Sweden)

    G. Alobaidi

    2006-01-01

    Full Text Available We use an asymptotic expansion to study the behavior of installment options close to expiry. Installment options are contracts where the price is paid over the life of the option rather than as a lump sum at the time of purchase, and where the contract can be allowed to lapse at any time. Series solutions are obtained for the location of the free boundary and the price of the option.

  7. Installation of Offshore Wind Turbine

    OpenAIRE

    Torgersrud, Amund; Fossestøl, Atle

    2011-01-01

    Ingenium AS is developing a new concept for transporting and installing fixed wind turbines, mainly jacket structures. As a part of the installation the jacket is lowered down to the seabed from a free hanging configuration, supported by a hydraulic frame. This operation is analyzed by use of the computer program Orcaflex, where the structure is modeled as rigid. Two critical scenarios are identified. In Scenario 1a the jacket is 10 m above seabed. Here, the jacket may collide with the suppor...

  8. Suitcase to Audit Solar Installations

    Energy Technology Data Exchange (ETDEWEB)

    Alberdi, J.; Barcala, J.M.; Blas de, J.; Molinero, A.; Navarrete, J.J.; Yuste, C.

    2001-07-01

    The audit suitcase was proposed by BESEL to introduce in the solar energy market a new tool which can make an evaluation of solar installation efficiency. Non-invasive sensors and low power components permit both easy installation of the devices and data storage for a period as long as ten days. This project was funded by the contract JOR3-CT98-7030 of the European Union JOULE III program. (Author)

  9. Broadband manipulation of acoustic wavefronts by pentamode metasurface

    Science.gov (United States)

    Tian, Ye; Wei, Qi; Cheng, Ying; Xu, Zheng; Liu, Xiaojun

    2015-11-01

    An acoustic metasurface with a sub-wavelength thickness can manipulate acoustic wavefronts freely by the introduction of abrupt phase variation. However, the existence of a narrow bandwidth and a low transmittance limits further applications. Here, we present a broadband and highly transparent acoustic metasurface based on a frequency-independent generalized acoustic Snell's law and pentamode metamaterials. The proposal employs a gradient velocity to redirect refracted waves and pentamode metamaterials to improve impedance matching between the metasurface and the background medium. Excellent wavefront manipulation based on the metasurface is further demonstrated by anomalous refraction, generation of non-diffracting Bessel beam, and sub-wavelength flat focusing.

  10. Broadband manipulation of acoustic wavefronts by pentamode metasurface

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Ye; Wei, Qi, E-mail: weiqi@nju.edu.cn; Cheng, Ying [Key Laboratory of Modern Acoustics, Department of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China); Xu, Zheng [School of Physics Science and Engineering, Tongji University, Shanghai 200092 (China); Liu, Xiaojun, E-mail: liuxiaojun@nju.edu.cn [Key Laboratory of Modern Acoustics, Department of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China); State Key Laboratory of Acoustics, Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190 (China)

    2015-11-30

    An acoustic metasurface with a sub-wavelength thickness can manipulate acoustic wavefronts freely by the introduction of abrupt phase variation. However, the existence of a narrow bandwidth and a low transmittance limits further applications. Here, we present a broadband and highly transparent acoustic metasurface based on a frequency-independent generalized acoustic Snell's law and pentamode metamaterials. The proposal employs a gradient velocity to redirect refracted waves and pentamode metamaterials to improve impedance matching between the metasurface and the background medium. Excellent wavefront manipulation based on the metasurface is further demonstrated by anomalous refraction, generation of non-diffracting Bessel beam, and sub-wavelength flat focusing.

  11. Application-Program-Installer Builder

    Science.gov (United States)

    Wolgast, Paul; Demore, Martha; Lowik, Paul

    2007-01-01

    A computer program builds application programming interfaces (APIs) and related software components for installing and uninstalling application programs in any of a variety of computers and operating systems that support the Java programming language in its binary form. This program is partly similar in function to commercial (e.g., Install-Shield) software. This program is intended to enable satisfaction of a quasi-industry-standard set of requirements for a set of APIs that would enable such installation and uninstallation and that would avoid the pitfalls that are commonly encountered during installation of software. The requirements include the following: 1) Properly detecting prerequisites to an application program before performing the installation; 2) Properly registering component requirements; 3) Correctly measuring the required hard-disk space, including accounting for prerequisite components that have already been installed; and 4) Correctly uninstalling an application program. Correct uninstallation includes (1) detecting whether any component of the program to be removed is required by another program, (2) not removing that component, and (3) deleting references to requirements of the to-be-removed program for components of other programs so that those components can be properly removed at a later time.

  12. Mechanical and vibro-acoustic aspects of composite sandwich cylinders

    NARCIS (Netherlands)

    Yuan, C.

    2013-01-01

    Designing a fuselage involves many considerations such as strength and stability, fatigue, damage tolerance, fire and lightning resistance, thermal and acoustic insulation, production, inspection, maintenance and repair. In the background of the application of composite sandwich structures on the ai

  13. Hawking radiation from acoustic black holes in two space dimensions

    CERN Document Server

    Eskin, Gregory

    2016-01-01

    We study the Hawking radiation from rotating acoustic black hole. We follow the approach of T.Jacobson and W.Unruh, although our approach differs in details. We also treat the case of variable velocity of the background flow.

  14. Subjective evaluation of restaurant acoustics in a virtual sound environment

    DEFF Research Database (Denmark)

    Nielsen, Nicolaj Østergaard; Marschall, Marton; Santurette, Sébastien;

    2016-01-01

    surveys report that noise complaints are on par with poor service. This study investigated the relation between objective acoustic parameters and subjective evaluation of acoustic comfort at five restaurants in terms of three parameters: noise annoyance, speech intelligibility, and privacy. At each...... location, customers filled out questionnaire surveys, acoustic parameters were measured, and recordings of restaurant acoustic scenes were obtained with a 64-channel spherical array. The acoustic scenes were reproduced in a virtual sound environment (VSE) with 64 loudspeakers placed in an anechoic room......, where listeners performed subjective evaluation of noise annoyance and privacy and a speech intelligibility test for each restaurant noise background. It was found that subjective evaluations of acoustic comfort correlate with occupancy rates and measured noise levels, that survey and listening test...

  15. Ambient background measurement at PUSHEP tunnel

    International Nuclear Information System (INIS)

    In view of upcoming INO laboratory in India, a feasibility study of neutrinoless double beta decay (0υββ) in 124Sn has been initiated. The objective is to make a prototype bolometric detector of 124Sn (∼ 1 Kg equivalent) and install it in a low background area

  16. The ATALANTE installation; L'installation atalante

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-10-01

    In the Atalante installation of the CEA/Marcoule, researches on the reprocessing of irradiated fuel from nuclear reactors, are performed. In the framework of the law (30 december 1991) on the public policy concerning the radioactive wastes management, the ATALANTE project has to proposed solutions for the long-dated management of these wastes and to help the reprocessing industry. The specifications of the installation and the research programs are detailed with a special interest for the glass durability and the plutonium purifying cycle. The public policy stakes are also recalled. (A.L.B.)

  17. Hanford Site background: Part 3, Groundwater background

    International Nuclear Information System (INIS)

    This report presents and interprets groundwater background data collected from the unconfined aquifer beneath the Hanford Site, a U.S. Department of Energy complex located near Richland, Washington. Characterization of background composition is an important component of environmental characterization activities and serves as a basis for distinguishing the presence and significance of contamination. Background data can also be used to assess the levels of baseline risk to which humans or other receptors are typically exposed and to establish remediation goals. Evaluating background on a sitewide basis provides a consistent, technically defensible definition of background as opposed to determining area-specific background compositions for each waste management unit being considered for remediation across the Hanford Site

  18. Speech Recognition in Natural Background Noise

    OpenAIRE

    Julien Meyer; Laure Dentel; Fanny Meunier

    2013-01-01

    In the real world, human speech recognition nearly always involves listening in background noise. The impact of such noise on speech signals and on intelligibility performance increases with the separation of the listener from the speaker. The present behavioral experiment provides an overview of the effects of such acoustic disturbances on speech perception in conditions approaching ecologically valid contexts. We analysed the intelligibility loss in spoken word lists with increasing listene...

  19. Monitoring and Analysis of In-Pile Phenomena in Advanced Test Reactor using Acoustic Telemetry

    Energy Technology Data Exchange (ETDEWEB)

    Agarwal, Vivek [Idaho National Lab. (INL), Idaho Falls, ID (United States). Dept. of Human Factors, Controls, and Statistics; Smith, James A. [Idaho National Lab. (INL), Idaho Falls, ID (United States). Dept. of Fuel Performance and Design; Jewell, James Keith [Idaho National Lab. (INL), Idaho Falls, ID (United States). Dept. of Fuel Performance and Design

    2015-02-01

    The interior of a nuclear reactor presents a particularly harsh and challenging environment for both sensors and telemetry due to high temperatures and high fluxes of energetic and ionizing particles among the radioactive decay products. A number of research programs are developing acoustic-based sensing approach to take advantage of the acoustic transmission properties of reactor cores. Idaho National Laboratory has installed vibroacoustic receivers on and around the Advanced Test Reactor (ATR) containment vessel to take advantage of acoustically telemetered sensors such as thermoacoustic (TAC) transducers. The installation represents the first step in developing an acoustic telemetry infrastructure. This paper presents the theory of TAC, application of installed vibroacoustic receivers in monitoring the in-pile phenomena inside the ATR, and preliminary data processing results.

  20. Monitoring and Analysis of In-Pile Phenomena in Advanced Test Reactor using Acoustic Telemetry

    International Nuclear Information System (INIS)

    The interior of a nuclear reactor presents a particularly harsh and challenging environment for both sensors and telemetry due to high temperatures and high fluxes of energetic and ionizing particles among the radioactive decay products. A number of research programs are developing acoustic-based sensing approach to take advantage of the acoustic transmission properties of reactor cores. Idaho National Laboratory has installed vibroacoustic receivers on and around the Advanced Test Reactor (ATR) containment vessel to take advantage of acoustically telemetered sensors such as thermoacoustic (TAC) transducers. The installation represents the first step in developing an acoustic telemetry infrastructure. This paper presents the theory of TAC, application of installed vibroacoustic receivers in monitoring the in-pile phenomena inside the ATR, and preliminary data processing results.

  1. Offshore Wind Energy Cost Modeling Installation and Decommissioning

    CERN Document Server

    Kaiser, Mark J

    2012-01-01

    Offshore wind energy is one of the most promising and fastest growing alternative energy sources in the world. Offshore Wind Energy Cost Modeling provides a methodological framework to assess installation and decommissioning costs, and using examples from the European experience, provides a broad review of existing processes and systems used in the offshore wind industry. Offshore Wind Energy Cost Modeling provides a step-by-step guide to modeling costs over four sections. These sections cover: ·Background and introductory material, ·Installation processes and vessel requirements, ·Installation cost estimation, and ·Decommissioning methods and cost estimation.  This self-contained and detailed treatment of the key principles in offshore wind development is supported throughout by visual aids and data tables. Offshore Wind Energy Cost Modeling is a key resource for anyone interested in the offshore wind industry, particularly those interested in the technical and economic aspects of installation and decom...

  2. Acoustics in Halls for Speech and Music

    Science.gov (United States)

    Gade, Anders C.

    This chapter deals specifically with concepts, tools, and architectural variables of importance when designing auditoria for speech and music. The focus will be on cultivating the useful components of the sound in the room rather than on avoiding noise from outside or from installations, which is dealt with in Chap. 11. The chapter starts by presenting the subjective aspects of the room acoustic experience according to consensus at the time of writing. Then follows a description of their objective counterparts, the objective room acoustic parameters, among which the classical reverberation time measure is only one of many, but still of fundamental value. After explanations on how these parameters can be measured and predicted during the design phase, the remainder of the chapter deals with how the acoustic properties can be controlled by the architectural design of auditoria. This is done by presenting the influence of individual design elements as well as brief descriptions of halls designed for specific purposes, such as drama, opera, and symphonic concerts. Finally, some important aspects of loudspeaker installations in auditoria are briefly touched upon.

  3. Springer handbook of acoustics

    CERN Document Server

    2014-01-01

    Acoustics, the science of sound, has developed into a broad interdisciplinary field encompassing the academic disciplines of physics, engineering, psychology, speech, audiology, music, architecture, physiology, neuroscience, and electronics. The Springer Handbook of Acoustics is also in his 2nd edition an unparalleled modern handbook reflecting this richly interdisciplinary nature edited by one of the acknowledged masters in the field, Thomas Rossing. Researchers and students benefit from the comprehensive contents. This new edition of the Handbook features over 11 revised and expanded chapters, new illustrations, and 2 new chapters covering microphone arrays  and acoustic emission.  Updated chapters contain the latest research and applications in, e.g. sound propagation in the atmosphere, nonlinear acoustics in fluids, building and concert hall acoustics, signal processing, psychoacoustics, computer music, animal bioacousics, sound intensity, modal acoustics as well as new chapters on microphone arrays an...

  4. Vibro-acoustics

    CERN Document Server

    Nilsson, Anders

    2015-01-01

    This three-volume book gives a thorough and comprehensive presentation of vibration and acoustic theories. Different from traditional textbooks which typically deal with some aspects of either acoustic or vibration problems, it is unique of this book to combine those two correlated subjects together. Moreover, it provides fundamental analysis and mathematical descriptions for several crucial phenomena of Vibro-Acoustics which are quite useful in noise reduction, including how structures are excited, energy flows from an excitation point to a sound radiating surface, and finally how a structure radiates noise to a surrounding fluid. Many measurement results included in the text make the reading interesting and informative. Problems/questions are listed at the end of each chapter and the solutions are provided. This will help the readers to understand the topics of Vibro-Acoustics more deeply. The book should be of interest to anyone interested in sound and vibration, vehicle acoustics, ship acoustics and inter...

  5. Installation Specifications of Air-Conditioners for Household and Similar Purposes

    Institute of Scientific and Technical Information of China (English)

    Hu Zhiqiang

    2011-01-01

    Background An air-conditioner known as "30% quality and 70% installation",the quality of its installation is closely related to its service life and application effect.Although air-conditioner manufacturers attach high importance to installation,and there are often the installation requirements specified in the product manual or instructions for installation,there are still no unified,scientific and complete national standards and corresponding regulations for household air-conditioner,which results in the less standardized installation of air-conditioner and the unacceptable quality of installation,and also leaves a lot of hidden quality and safety problems.By means of extensive market survey and the after-sale information statistical analysis of air-conditioner,it is discovered that the nonstandard installation of air-conditioner may lead to the following problems and accidents.

  6. Installation of Offshore Wind Turbine

    OpenAIRE

    Torgersrud, Amund; Fossestøl, Atle

    2011-01-01

    Ingenium AS is developing a new concept for transporting and installing fixed wind turbines, mainly jacket structures. As a part of the installation the jacket is lowered down to the seabed from a free hanging configuration, supported by a hydraulic frame.This operation is analyzed by use of the computer program Orcaflex, where the structure is modeled as rigid.Two critical scenarios are identified. In Scenario 1a the jacket is 10 m above seabed. Here, the jacket may collide with the support ...

  7. Shallow Water Acoustic Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Supports experimental research where high-frequency acoustic scattering and surface vibration measurements of fluid-loaded and non-fluid-loaded structures...

  8. Low frequency acoustic microscope

    Science.gov (United States)

    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.

  9. Localized acoustic surface modes

    Science.gov (United States)

    Farhat, Mohamed; Chen, Pai-Yen; Bağcı, Hakan

    2016-04-01

    We introduce the concept of localized acoustic surface modes. We demonstrate that they are induced on a two-dimensional cylindrical rigid surface with subwavelength corrugations under excitation by an incident acoustic plane wave. Our results show that the corrugated rigid surface is acoustically equivalent to a cylindrical scatterer with uniform mass density that can be represented using a Drude-like model. This, indeed, suggests that plasmonic-like acoustic materials can be engineered with potential applications in various areas including sensing, imaging, and cloaking.

  10. Localized Acoustic Surface Modes

    KAUST Repository

    Farhat, Mohamed

    2015-08-04

    We introduce the concept of localized acoustic surface modes (ASMs). We demonstrate that they are induced on a two-dimensional cylindrical rigid surface with subwavelength corrugations under excitation by an incident acoustic plane wave. Our results show that the corrugated rigid surface is acoustically equivalent to a cylindrical scatterer with uniform mass density that can be represented using a Drude-like model. This, indeed, suggests that plasmonic-like acoustic materials can be engineered with potential applications in various areas including sensing, imaging, and cloaking.

  11. What Is an Acoustic Neuroma

    Science.gov (United States)

    ... org Connect with us! What is an Acoustic Neuroma? Each heading slides to reveal information. Important Points ... Neuroma Important Points To Know About an Acoustic Neuroma An acoustic neuroma, also called a vestibular schwannoma, ...

  12. Acoustic wayfinding: A method to measure the acoustic contrast of different paving materials for blind people.

    Science.gov (United States)

    Secchi, Simone; Lauria, Antonio; Cellai, Gianfranco

    2017-01-01

    Acoustic wayfinding involves using a variety of auditory cues to create a mental map of the surrounding environment. For blind people, these auditory cues become the primary substitute for visual information in order to understand the features of the spatial context and orient themselves. This can include creating sound waves, such as tapping a cane. This paper reports the results of a research about the "acoustic contrast" parameter between paving materials functioning as a cue and the surrounding or adjacent surface functioning as a background. A number of different materials was selected in order to create a test path and a procedure was defined for the verification of the ability of blind people to distinguish different acoustic contrasts. A method is proposed for measuring acoustic contrast generated by the impact of a cane tip on the ground to provide blind people with environmental information on spatial orientation and wayfinding in urban places. PMID:27633240

  13. Acoustic Data Processing and Transient Signal Analysis for the Hybrid Wing Body 14- by 22-Foot Subsonic Wind Tunnel Test

    Science.gov (United States)

    Bahr, Christopher J.; Brooks, Thomas F.; Humphreys, William M.; Spalt, Taylor B.; Stead, Daniel J.

    2014-01-01

    An advanced vehicle concept, the HWB N2A-EXTE aircraft design, was tested in NASA Langley's 14- by 22-Foot Subsonic Wind Tunnel to study its acoustic characteristics for var- ious propulsion system installation and airframe con gurations. A signi cant upgrade to existing data processing systems was implemented, with a focus on portability and a re- duction in turnaround time. These requirements were met by updating codes originally written for a cluster environment and transferring them to a local workstation while en- abling GPU computing. Post-test, additional processing of the time series was required to remove transient hydrodynamic gusts from some of the microphone time series. A novel automated procedure was developed to analyze and reject contaminated blocks of data, under the assumption that the desired acoustic signal of interest was a band-limited sta- tionary random process, and of lower variance than the hydrodynamic contamination. The procedure is shown to successfully identify and remove contaminated blocks of data and retain the desired acoustic signal. Additional corrections to the data, mainly background subtraction, shear layer refraction calculations, atmospheric attenuation and microphone directivity corrections, were all necessary for initial analysis and noise assessments. These were implemented for the post-processing of spectral data, and are shown to behave as expected.

  14. Horn installed in CNGS tunnel

    CERN Multimedia

    Maximilien Brice

    2005-01-01

    The horn is installed for the CERN Neutrinos to Gran Sasso (CNGS) project. Protons collide with a graphite target producing charged particles that are focussed by the magnetic field in the horn. These particles will then pass into a decay tube where they decay into neutrinos, which travel towards a detector at Gran Sasso 732 km away in Italy.

  15. Predicting Acoustics in Class Rooms

    DEFF Research Database (Denmark)

    Christensen, Claus Lynge; Rindel, Jens Holger

    2005-01-01

    Typical class rooms have fairly simple geometries, even so room acoustics in this type of room is difficult to predict using today's room acoustic computer modeling software. The reasons why acoustics of class rooms are harder to predict than acoustics of complicated concert halls might be explai......Typical class rooms have fairly simple geometries, even so room acoustics in this type of room is difficult to predict using today's room acoustic computer modeling software. The reasons why acoustics of class rooms are harder to predict than acoustics of complicated concert halls might...... with surface scattering is presented. Each of the two scattering effects is modeled as frequency dependent functions....

  16. Feature based passive acoustic detection of underwater threats

    Science.gov (United States)

    Stolkin, Rustam; Sutin, Alexander; Radhakrishnan, Sreeram; Bruno, Michael; Fullerton, Brian; Ekimov, Alexander; Raftery, Michael

    2006-05-01

    Stevens Institute of Technology is performing research aimed at determining the acoustical parameters that are necessary for detecting and classifying underwater threats. This paper specifically addresses the problems of passive acoustic detection of small targets in noisy urban river and harbor environments. We describe experiments to determine the acoustic signatures of these threats and the background acoustic noise. Based on these measurements, we present an algorithm for robustly discriminating threat presence from severe acoustic background noise. Measurements of the target's acoustic radiation signal were conducted in the Hudson River. The acoustic noise in the Hudson River was also recorded for various environmental conditions. A useful discriminating feature can be extracted from the acoustic signal of the threat, calculated by detecting packets of multi-spectral high frequency sound which occur repetitively at low frequency intervals. We use experimental data to show how the feature varies with range between the sensor and the detected underwater threat. We also estimate the effective detection range by evaluating this feature for hydrophone signals, recorded in the river both with and without threat presence.

  17. 3D acoustic imaging applied to the Baikal neutrino telescope

    International Nuclear Information System (INIS)

    A hydro-acoustic imaging system was tested in a pilot study on distant localization of elements of the Baikal underwater neutrino telescope. For this innovative approach, based on broad band acoustic echo signals and strictly avoiding any active acoustic elements on the telescope, the imaging system was temporarily installed just below the ice surface, while the telescope stayed in its standard position at 1100 m depth. The system comprised an antenna with four acoustic projectors positioned at the corners of a 50 m square; acoustic pulses were 'linear sweep-spread signals'-multiple-modulated wide-band signals (10→22 kHz) of 51.2 s duration. Three large objects (two string buoys and the central electronics module) were localized by the 3D acoustic imaging, with an accuracy of ∼0.2 m (along the beam) and ∼1.0 m (transverse). We discuss signal forms and parameters necessary for improved 3D acoustic imaging of the telescope, and suggest a layout of a possible stationary bottom based 3D imaging setup. The presented technique may be of interest for neutrino telescopes of km3-scale and beyond, as a flexible temporary or as a stationary tool to localize basic telescope elements, while these are completely passive.

  18. Acoustic levitator for containerless measurements on low temperature liquids

    Energy Technology Data Exchange (ETDEWEB)

    Benmore, Chris J [Argonne National Laboratory (ANL); Weber, Richard [Argonne National Laboratory (ANL); Neuefeind, Joerg C [ORNL; Rey, Charles A A [Charles Ray, Inc.

    2009-01-01

    A single-axis acoustic levitator was constructed and used to levitate liquid and solid drops at temperatures from -40 to +40 C. The levitator consisted of: (i) two acoustic transducers mounted on a rigid vertical support that was bolted to an optical breadboard, (ii) a acoustic power supply that controlled acoustic intensity, relative phase of the drive to the transducers, and could modulate the acoustic forces at frequencies up to 1kHz, (iii) a video camera, and (iv) a system for providing a stream of controlled temperature gas flow over the sample. The acoustic transducers were operated at their resonant frequency of ~ 22 kHz and could produce sound pressure levels up to 160 dB. The force applied by the acoustic field could be modulated using a frequency generator to excite oscillations in the sample. Sample temperature was controlled using a modified Cryostream Plus and measured using thermocouples and an infrared thermal imager. The levitator was installed at x-ray beamline 11 ID-C at the Advanced Photon Source and used to investigate the structure of supercooled liquids.

  19. 3D acoustic imaging applied to the Baikal neutrino telescope

    Energy Technology Data Exchange (ETDEWEB)

    Kebkal, K.G. [EvoLogics GmbH, Blumenstrasse 49, 10243 Berlin (Germany)], E-mail: kebkal@evologics.de; Bannasch, R.; Kebkal, O.G. [EvoLogics GmbH, Blumenstrasse 49, 10243 Berlin (Germany); Panfilov, A.I. [Institute for Nuclear Research, 60th October Anniversary pr. 7a, Moscow 117312 (Russian Federation); Wischnewski, R. [DESY, Platanenallee 6, 15735 Zeuthen (Germany)

    2009-04-11

    A hydro-acoustic imaging system was tested in a pilot study on distant localization of elements of the Baikal underwater neutrino telescope. For this innovative approach, based on broad band acoustic echo signals and strictly avoiding any active acoustic elements on the telescope, the imaging system was temporarily installed just below the ice surface, while the telescope stayed in its standard position at 1100 m depth. The system comprised an antenna with four acoustic projectors positioned at the corners of a 50 m square; acoustic pulses were 'linear sweep-spread signals'-multiple-modulated wide-band signals (10{yields}22 kHz) of 51.2 s duration. Three large objects (two string buoys and the central electronics module) were localized by the 3D acoustic imaging, with an accuracy of {approx}0.2 m (along the beam) and {approx}1.0 m (transverse). We discuss signal forms and parameters necessary for improved 3D acoustic imaging of the telescope, and suggest a layout of a possible stationary bottom based 3D imaging setup. The presented technique may be of interest for neutrino telescopes of km{sup 3}-scale and beyond, as a flexible temporary or as a stationary tool to localize basic telescope elements, while these are completely passive.

  20. 46 CFR 119.220 - Installations.

    Science.gov (United States)

    2010-10-01

    ... PASSENGERS OR WITH OVERNIGHT ACCOMMODATIONS FOR MORE THAN 49 PASSENGERS MACHINERY INSTALLATION Propulsion Machinery § 119.220 Installations. (a) The installation requirements for machinery and boilers for steam and... subchapter J (Electrical Engineering) of this chapter. (b) Installation of propulsion machinery of an...

  1. Engineering acoustics: A pioneer undergraduate program at Rio de Janeiro

    Science.gov (United States)

    Tenenbaum, Roberto A.; Zindeluk, Moyses

    2002-11-01

    Acoustics, essentially a multidisciplinary subject, still has in Brazil a small but increasing number of professionals with a solid background to deal with various aspects of this area. Since 1970 the faculty of the Acoustics and Vibration Laboratory, COPPE/UFRJ, offers graduate (M.Sc and D.Sc) programs, and some undergraduate courses in acoustics, vibration, and signal processing. In January 2000, this group launched a formal undergraduate engineering acoustics program in the Mechanical Engineering Department of the Federal University of Rio de Janeiro. After three years of mechanical engineering, with a firm foundation in physics, applied mathematics, and engineering basics, the undergraduate student may elect to take the engineering acoustics program for the remaining two years. In this program, a wide number of courses are offered, including basic acoustics, room acoustics, signal processing, musical acoustics, machine diagnosis, etc. Approximately 30 different courses may be chosen from. However, the student is not completely free, since the courses selected must fit within a subject concentration profile, e.g., noise control or musical acoustics. In this paper the programs curriculum are presented and its impact on the students is discussed. A first evaluation of the qualifications achieved by the graduate students in the area is also presented.

  2. Ocean acoustic reverberation tomography.

    Science.gov (United States)

    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., 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.

  3. Acoustic Signals and Systems

    DEFF Research Database (Denmark)

    2008-01-01

    The Handbook of Signal Processing in Acoustics will compile the techniques and applications of signal processing as they are used in the many varied areas of Acoustics. The Handbook will emphasize the interdisciplinary nature of signal processing in acoustics. Each Section of the Handbook...... will present topics on signal processing which are important in a specific area of acoustics. These will be of interest to specialists in these areas because they will be presented from their technical perspective, rather than a generic engineering approach to signal processing. Non-specialists, or specialists...... from different areas, will find the self-contained chapters accessible and will be interested in the similarities and differences between the approaches and techniques used in different areas of acoustics....

  4. Ocean acoustic hurricane classification.

    Science.gov (United States)

    Wilson, Joshua D; Makris, Nicholas C

    2006-01-01

    Theoretical and empirical evidence are combined to show that underwater acoustic sensing techniques may be valuable for measuring the wind speed and determining the destructive power of a hurricane. This is done by first developing a model for the acoustic intensity and mutual intensity in an ocean waveguide due to a hurricane and then determining the relationship between local wind speed and underwater acoustic intensity. From this it is shown that it should be feasible to accurately measure the local wind speed and classify the destructive power of a hurricane if its eye wall passes directly over a single underwater acoustic sensor. The potential advantages and disadvantages of the proposed acoustic method are weighed against those of currently employed techniques. PMID:16454274

  5. Cochlear bionic acoustic metamaterials

    Science.gov (United States)

    Ma, Fuyin; Wu, Jiu Hui; Huang, Meng; Fu, Gang; Bai, Changan

    2014-11-01

    A design of bionic acoustic metamaterial and acoustic functional devices was proposed by employing the mammalian cochlear as a prototype. First, combined with the experimental data in previous literatures, it is pointed out that the cochlear hair cells and stereocilia cluster are a kind of natural biological acoustic metamaterials with the negative stiffness characteristics. Then, to design the acoustic functional devices conveniently in engineering application, a simplified parametric helical structure was proposed to replace actual irregular cochlea for bionic design, and based on the computational results of such a bionic parametric helical structure, it is suggested that the overall cochlear is a local resonant system with the negative dynamic effective mass characteristics. There are many potential applications in the bandboard energy recovery device, cochlear implant, and acoustic black hole.

  6. Computational Ocean Acoustics

    CERN Document Server

    Jensen, Finn B; Porter, Michael B; Schmidt, Henrik

    2011-01-01

    Since the mid-1970s, the computer has played an increasingly pivotal role in the field of ocean acoustics. Faster and less expensive than actual ocean experiments, and capable of accommodating the full complexity of the acoustic problem, numerical models are now standard research tools in ocean laboratories. The progress made in computational ocean acoustics over the last thirty years is summed up in this authoritative and innovatively illustrated new text. Written by some of the field's pioneers, all Fellows of the Acoustical Society of America, Computational Ocean Acoustics presents the latest numerical techniques for solving the wave equation in heterogeneous fluid–solid media. The authors discuss various computational schemes in detail, emphasizing the importance of theoretical foundations that lead directly to numerical implementations for real ocean environments. To further clarify the presentation, the fundamental propagation features of the techniques are illustrated in color. Computational Ocean A...

  7. ONKALO POSE experiment. Phase 3: acoustic and ultrasonic monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Reyes-Montes, J.; Flynn, W.; Huang, J. [Applied Seismology Consultants, Shrewsbury (United Kingdom)

    2014-01-15

    The objectives of the third phase of the POSE experiment are to determine the in situ state of stress at Olkiluoto and the spalling strength of Olkiluoto rock, by internal heating of the experimental hole (ONK-EH3) using 8 vertically installed heaters. This report presents the results from the Acoustic and ultrasonic monitoring carried out around the third experimental hole of the POSE niche between November 2012 and May 2013. The experiment was monitored using an array of 24 transducers installed along 4 monitoring drillholes and data was automatically acquired and processed using the system installed at the niche by Applied Seismology Consultants in May 2012. Daily ultrasonic surveys were carried out between 14{sup th} November 2012 and 21{sup st} May 2013, monitoring the changes in transmission velocities of P and S-waves with an estimated error of ±2 m x s{sup -1} (ASC, 2013). Changes in transmission velocities closely follow the evolution of the temperature profile in the hole wall. An increase in both P-and S-wave transmission velocities is observed at all depth levels and surveyed raypaths during the heating phase, with the highest changes observed in raypaths skimming the hole surface and depths between 2.33 m and 3.7 m. This observation indicates the closure of in situ and excavation-induced microcracks due to thermal stress. After the heaters were switched off, P-wave velocities show a marked decrease, in all raypaths reaching values below those measured at the start of the monitoring approximately 4 weeks after the heaters were switched off. The highest decrease was observed along raypaths surveying the region skimming the hole wall. This decrease below original background values indicates the induction of rock degradation as microcracking induced through the heating-cooling cycle. Changes in P- and S-wave transmission velocity were used to calculate changes in Young's modulus and Poisson's ratio along the different raypaths and depth levels

  8. Quality assurance in nuclear installations

    International Nuclear Information System (INIS)

    It has been proven that the bad quality of products, equipment, installations, and services is not due to the lack of tests, experiments and verifications. The main causes are associated with insufficient organization of the activities that have influence on the quality. The garantee of quality is conceptualized as an appropriate instrument composed of normalized criteria initially in advanced technologies. Such as nuclear science and aerospace technology. However, with the appropriate modifications it can be applied to conventional technologies

  9. Designing compressor installations for reliability

    Energy Technology Data Exchange (ETDEWEB)

    Greenfield, S.D.; Howes, B.C.; Robinson, A.; Eckert, W.

    2000-07-01

    The best approach to the design of a new centrifugal or reciprocating compressor that will ensure reliability, performance and maintenance of the equipment involves the use of analytical tools. One must understand the sources of the potential problems and consequences along with the availability of design services. At that point risk assessment can be performed. The objective is to keep pulsations, vibration levels and dynamic stresses low, so as to minimally impact on the performance and reliability and maintain control over costs. The consideration of forcing functions, natural frequencies, mode shapes and dynamic stiffness is essential, as they apply to rotor dynamics, torsional vibration, piping vibration, skid and foundation vibration. It also applies to the interaction of the piping geometry with pressure pulsations which can produce significant forces and stresses for both reciprocating and centrifugal compressors and lead to a decrease in performance. The authors described the considerations that help determine which analytical tool is best to develop a computer model that can be used to avoid problems. Three cases were introduced to better illustrate the advantages of adequate design modeling and optimization. Each case deals with a different problem: (1) a lateral critical and a structural resonance in a centrifugal compressor installation, (2) a piping failure in a reciprocating compressor installation, and (3) a torsional failure in a reciprocating compressor installation. 1 ref., 2 tabs., 3 figs.

  10. Acoustic Flow Monitor System - User Manual

    Science.gov (United States)

    LaHusen, Richard

    2005-01-01

    INTRODUCTION The Acoustic Flow Monitor (AFM) is a portable system that was designed by the U.S. Geological Survey Cascades Volcano Observatory to detect and monitor debris flows associated with volcanoes. It has been successfully used internationally as part of real-time warning systems in valleys threatened by such flows (Brantley, 1990; Marcial and others, 1996; Lavigne and others, 2000). The AFM system has also been proven to be an effective tool for monitoring some non-volcanic debris flows. This manual is intended to serve as a basic guide for the installation, testing, and maintenance of AFM systems. An overview of how the system works, as well as instructions for installation and guidelines for testing, is included. Interpretation of data is not covered in this manual; rather, the user should refer to the references provided for published examples of AFM data.

  11. Flat acoustic lens by acoustic grating with curled slits

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Pai; Xiao, Bingmu; Wu, Ying, E-mail: ying.wu@kaust.edu.sa

    2014-10-03

    We design a flat sub-wavelength lens that can focus acoustic wave. We analytically study the transmission through an acoustic grating with curled slits, which can serve as a material with tunable impedance and refractive index for acoustic waves. The effective parameters rely on the geometry of the slits and are independent of frequency. A flat acoustic focusing lens by such acoustic grating with gradient effective refractive index is designed. The focusing effect is clearly observed in simulations and well predicted by the theory. We demonstrate that despite the large impedance mismatch between the acoustic lens and the matrix, the intensity at the focal point is still high due to Fabry–Perot resonance. - Highlights: • Expression of transmission coefficient of an acoustic grating with curled slits. • Non-dispersive and tunable effective medium parameters for the acoustic grating. • A flat acoustic focusing lens with gradient index by using the acoustic grating.

  12. Acoustic mapping velocimetry

    Science.gov (United States)

    Muste, M.; Baranya, S.; Tsubaki, R.; Kim, D.; Ho, H.; Tsai, H.; Law, D.

    2016-05-01

    Knowledge of sediment dynamics in rivers is of great importance for various practical purposes. Despite its high relevance in riverine environment processes, the monitoring of sediment rates remains a major and challenging task for both suspended and bed load estimation. While the measurement of suspended load is currently an active area of testing with nonintrusive technologies (optical and acoustic), bed load measurement does not mark a similar progress. This paper describes an innovative combination of measurement techniques and analysis protocols that establishes the proof-of-concept for a promising technique, labeled herein Acoustic Mapping Velocimetry (AMV). The technique estimates bed load rates in rivers developing bed forms using a nonintrusive measurements approach. The raw information for AMV is collected with acoustic multibeam technology that in turn provides maps of the bathymetry over longitudinal swaths. As long as the acoustic maps can be acquired relatively quickly and the repetition rate for the mapping is commensurate with the movement of the bed forms, successive acoustic maps capture the progression of the bed form movement. Two-dimensional velocity maps associated with the bed form migration are obtained by implementing algorithms typically used in particle image velocimetry to acoustic maps converted in gray-level images. Furthermore, use of the obtained acoustic and velocity maps in conjunction with analytical formulations (e.g., Exner equation) enables estimation of multidirectional bed load rates over the whole imaged area. This paper presents a validation study of the AMV technique using a set of laboratory experiments.

  13. Integration of Acoustic Neutrino Detection Methods into ANTARES

    International Nuclear Information System (INIS)

    The ANTARES Neutrino Telescope is a water Cherenkov detector currently under construction in the Mediterranean Sea. It is also designed to serve as a platform for investigations of the deep-sea environment. In this context, the ANTARES group at the University of Erlangen will integrate acoustic sensors within the infrastructure of the experiment. With this dedicated setup, tests of acoustic particle detection methods and deep-sea acoustic background studies shall be performed. The aim of this project is to evaluate the feasibility of a future acoustic neutrino telescope in the deep sea operating in the ultra-high energy regime. In these proceedings, the implementation of the project is described in the context of the premises and challenges set by the physics of acoustic particle detection and the integration into an existing infrastructure

  14. Integration of Acoustic Neutrino Detection Methods into ANTARES

    CERN Document Server

    Graf, K; Hoessl, J; Kappes, A; Katz, U F; Lahmann, R; Naumann, C; Salomon, K

    2007-01-01

    The ANTARES Neutrino Telescope is a water Cherenkov detector currently under construction in the Mediterranean Sea. It is also designed to serve as a platform for investigations of the deep-sea environment. In this context, the ANTARES group at the University of Erlangen will integrate acoustic sensors within the infrastructure of the experiment. With this dedicated setup, tests of acoustic particle detection methods and deep-sea acoustic background studies shall be performed. The aim of this project is to evaluate the feasibility of a future acoustic neutrino telescope in the deep sea operating in the ultra-high energy regime. In these proceedings, the implementation of the project is described in the context of the premises and challenges set by the physics of acoustic particle detection and the integration into an existing infrastructure.

  15. From Architectural Acoustics to Acoustical Architecture Using Computer Simulation

    OpenAIRE

    Schmidt, Anne Marie Due; KIRKEGAARD, Poul Henning

    2005-01-01

    Architectural acoustics design has in the past been based on simple design rules. However, with a growing complexity in architectural acoustics and the emergence of room acoustic simulation programmes with considerable potential, it is now possible to subjectively analyse and evaluate acoustic properties prior to the actual construction of a building. With the right tools applied, acoustic design can become an integral part of the architectural design process. The aim of this paper is to inve...

  16. Underwater Applications of Acoustical Holography

    Directory of Open Access Journals (Sweden)

    P. C. Mehta

    1984-01-01

    Full Text Available The paper describes the basic technique of acoustical holography. Requirements for recording the acoustical hologram are discussed with its ability for underwater imaging in view. Some practical systems for short-range and medium-range imaging are described. The advantages of acoustical holography over optical imaging, acoustical imaging and sonars are outlined.

  17. Opto acoustical gravitational bar detector with cryogenic mirrors

    CERN Document Server

    Kulagin, V V; Popov, S M; Rudenko, V N; Skvortsov, M N; Yudin, I S

    2016-01-01

    Enhancing of sensitivity of the opto-acoustical gravitational wave (GW) antenna OGRAN installed in the underground facilities of Baksan Neutrino Observatory is analyzed. Calculations are presented showing a sensitivity improving on two orders of value after a cooling the solid body acoustical part of the antenna to the nitrogen temperature. A possibility of keeping of the same optical scheme of the antenna at low temperature is discussed. Design of modernized construction for cryogenic version of the antenna OGRAN is described. Test experiments with cooled pilot model carrying cryogenic mirrors illuminated by the optical pump up to 0.5 W are presented.

  18. Building Background Knowledge

    Science.gov (United States)

    Neuman, Susan B.; Kaefer, Tanya; Pinkham, Ashley

    2014-01-01

    This article make a case for the importance of background knowledge in children's comprehension. It suggests that differences in background knowledge may account for differences in understanding text for low- and middle-income children. It then describes strategies for building background knowledge in the age of common core standards.

  19. Ocean acoustic reverberation tomography.

    Science.gov (United States)

    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., 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. PMID:26723303

  20. Autonomous Acoustic Receiver System

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Collects underwater acoustic data and oceanographic data. Data are recorded onboard an ocean buoy and can be telemetered to a remote ship or shore station...

  1. Thermal Acoustic Fatigue Apparatus

    Data.gov (United States)

    Federal Laboratory Consortium — The Thermal Acoustic Fatigue Apparatus (TAFA) is a progressive wave tube test facility that is used to test structures for dynamic response and sonic fatigue due to...

  2. Acoustic Igniter Project

    Data.gov (United States)

    National Aeronautics and Space Administration — An acoustic igniter eliminates the need to use electrical energy to drive spark systems to initiate combustion in liquid-propellant rockets. It does not involve the...

  3. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... treatment Summary Types Of Post-treatment Issues Resources Medical Resources Considerations When Selecting a Healthcare Professional Healthcare ... ANA? Mission Statement Board of Directors ANA Staff Medical Advisory Board News ANA Annual Reports Acoustic Neuroma ...

  4. Acoustics lecturing in Mexico

    Science.gov (United States)

    Beristain, Sergio

    2002-11-01

    Some thirty years ago acoustics lecturing started in Mexico at the National Polytechnic Institute in Mexico City, as part of the Bachelor of Science degree in Communications and Electronics Engineering curricula, including the widest program on this field in the whole country. This program has been producing acoustics specialists ever since. Nowadays many universities and superior education institutions around the country are teaching students at the B.Sc. level and postgraduate level many topics related to acoustics, such as Architectural Acoustics, Seismology, Mechanical Vibrations, Noise Control, Audio, Audiology, Music, etc. Also many institutions have started research programs in related fields, with participation of medical doctors, psychologists, musicians, engineers, etc. Details will be given on particular topics and development.

  5. Principles of musical acoustics

    CERN Document Server

    Hartmann, William M

    2013-01-01

    Principles of Musical Acoustics focuses on the basic principles in the science and technology of music. Musical examples and specific musical instruments demonstrate the principles. The book begins with a study of vibrations and waves, in that order. These topics constitute the basic physical properties of sound, one of two pillars supporting the science of musical acoustics. The second pillar is the human element, the physiological and psychological aspects of acoustical science. The perceptual topics include loudness, pitch, tone color, and localization of sound. With these two pillars in place, it is possible to go in a variety of directions. The book treats in turn, the topics of room acoustics, audio both analog and digital, broadcasting, and speech. It ends with chapters on the traditional musical instruments, organized by family. The mathematical level of this book assumes that the reader is familiar with elementary algebra. Trigonometric functions, logarithms and powers also appear in the book, but co...

  6. Helium transfer line installation details.

    CERN Multimedia

    G. Perinic

    2007-01-01

    A particularity of the 32 m long four in one helium transfer line in between the cold box in USC55 and the cavern UX5 is the fact that the transfer line passes through a hole in the crane rail support beam. In order to ensure the alignment of the suspension rail in the interconnecting tunnel with the hole in the rail support as well as the connection points at both ends required precise measurements of the given geometries as well as the installation of a temporary target for the verification of the theoretical predictions.

  7. Development of an acoustic steam generator leak detection system using delay-and-sum beamformer

    International Nuclear Information System (INIS)

    A new acoustic steam generator leak detection system using delay-and-sum beamformer is proposed. The major advantage of the delay-and-sum beamformer is it could provide information of acoustic source direction. An acoustic source of a sodium-water reaction is supposed to be localized while the background noise of the steam generator operation is uniformly distributed in the steam generator tube region. Therefore the delay-and-sum beamformer could distinguish the acoustic source of the sodium-water reaction from steam generator background noise. In this paper, results from numerical analyses are provided to show fundamental feasibility of the new method. (author)

  8. Anal acoustic reflectometry

    DEFF Research Database (Denmark)

    Mitchell, Peter J; Klarskov, Niels; Telford, Karen J;

    2011-01-01

    Anal acoustic reflectometry is a new technique of assessing anal sphincter function. Five new variables reflecting anal canal function are measured: the opening and closing pressure, the opening and closing elastance, and hysteresis.......Anal acoustic reflectometry is a new technique of assessing anal sphincter function. Five new variables reflecting anal canal function are measured: the opening and closing pressure, the opening and closing elastance, and hysteresis....

  9. Acoustic surface cavitation

    OpenAIRE

    Zijlstra, Aaldert Geert

    2011-01-01

    Merely the presence of compressible entities, known as bubbles, greatly enriches the physical phenomena encountered when introducing ultrasound in a liquid. Mediated by the response of these bubbles, the otherwise diffuse and relatively low energy density of the acoustic field can induce strong, localized liquid motion, high internal temperatures and pressures as well as secondary acoustic emissions. In turn, these effects give rise to considerable stresses exerted on nearby objects and molec...

  10. Wavefront modulation and subwavelength diffractive acoustics with an acoustic metasurface.

    Science.gov (United States)

    Xie, Yangbo; Wang, Wenqi; Chen, Huanyang; Konneker, Adam; Popa, Bogdan-Ioan; Cummer, Steven A

    2014-01-01

    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. PMID:25418084

  11. Mechanical and vibro-acoustic aspects of composite sandwich cylinders

    OpenAIRE

    Yuan, C.

    2013-01-01

    Designing a fuselage involves many considerations such as strength and stability, fatigue, damage tolerance, fire and lightning resistance, thermal and acoustic insulation, production, inspection, maintenance and repair. In the background of the application of composite sandwich structures on the aircraft fuselage, the focus of the thesis is to investigate the vibration and acoustic behaviours of sandwich structures. As a preliminary design of aircraft fuselages, a sizing work of sandwich cyl...

  12. Signal Classification for Acoustic Neutrino Detection

    CERN Document Server

    Neff, M; Enzenhöfer, A; Graf, K; Hößl, J; Katz, U; Lahmann, R; Richardt, C

    2011-01-01

    This article focuses on signal classification for deep-sea acoustic neutrino detection. In the deep sea, the background of transient signals is very diverse. Approaches like matched filtering are not sufficient to distinguish between neutrino-like signals and other transient signals with similar signature, which are forming the acoustic background for neutrino detection in the deep-sea environment. A classification system based on machine learning algorithms is analysed with the goal to find a robust and effective way to perform this task. For a well-trained model, a testing error on the level of one percent is achieved for strong classifiers like Random Forest and Boosting Trees using the extracted features of the signal as input and utilising dense clusters of sensors instead of single sensors.

  13. Installation package for a solar heating system

    Science.gov (United States)

    1978-01-01

    Installation information is given for a solar heating system installed in Concho Indian School at El Reno, Oklahoma. This package includes a system Operation and Maintenance Manual, hardware brochures, schematics, system operating modes and drawings.

  14. 46 CFR 182.310 - Installations.

    Science.gov (United States)

    2010-10-01

    ...) MACHINERY INSTALLATION Auxiliary Machinery § 182.310 Installations. (a) Auxiliary machinery of the internal combustion piston type must comply with the provisions of this part. (b) Auxiliary machinery of the steam...

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

    Science.gov (United States)

    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. PMID:23363092

  16. 46 CFR 120.354 - Battery installations.

    Science.gov (United States)

    2010-10-01

    ... PASSENGERS OR WITH OVERNIGHT ACCOMMODATIONS FOR MORE THAN 49 PASSENGERS ELECTRICAL INSTALLATION Power Sources... installation must be located in a locker, room or enclosed box solely dedicated to the storage of batteries... batteries. Each small battery installation must be located in a well ventilated space and protected...

  17. Tools For Installing Keys On A Stud

    Science.gov (United States)

    Goodoak, Robert D.

    1995-01-01

    Two tools designed to be used together to drive long locking keys axially to install them on stud. Tools are: supporter holding keys in correct relative alignment and driver having multiple prongs, each of which fits into one of holes in supporter. Tools prevent bending and breaking of keys during installation, and make possible to install all keys simultaneously, in one motion.

  18. Measuring acoustic emissions in an avalanche slope

    Science.gov (United States)

    Reiweger, Ingrid; Schweizer, Jürg

    2014-05-01

    Measurements of acoustic emissions are a common technique for monitoring damage and predicting imminent failure of a material. Within natural hazards it has already been used to successfully predict the break-off of a hanging glacier. To explore the applicability of the acoustic emission (AE) technique for avalanche prediction, we installed two acoustic sensors (with 30 kHz and 60 kHz resonance frequency) in an avalanche prone slope at the Mittelgrat in the Parsenn ski area above Davos, Switzerland. The slope is north-east facing, frequently wind loaded, and approximately 35° steep. The AE signals - in particular the event energy and waiting time distributions - were compared with slope stability. The latter was determined by observing avalanche activity. The results of two winter's measurements yielded that the exponent β of the inverse cumulative distribution of event energy showed a significant drop (from a value of 3.5 to roughly 2.5) at very unstable conditions, i.e. on the three days during our measurement periods when spontaneous avalanches released on our study slope.

  19. Acoustic Emission Analysis Applet (AEAA) Software

    Science.gov (United States)

    Nichols, Charles T.; Roth, Don J.

    2013-01-01

    NASA Glenn Research and NASA White Sands Test Facility have developed software supporting an automated pressure vessel structural health monitoring (SHM) system based on acoustic emissions (AE). The software, referred to as the Acoustic Emission Analysis Applet (AEAA), provides analysts with a tool that can interrogate data collected on Digital Wave Corp. and Physical Acoustics Corp. software using a wide spectrum of powerful filters and charts. This software can be made to work with any data once the data format is known. The applet will compute basic AE statistics, and statistics as a function of time and pressure (see figure). AEAA provides value added beyond the analysis provided by the respective vendors' analysis software. The software can handle data sets of unlimited size. A wide variety of government and commercial applications could benefit from this technology, notably requalification and usage tests for compressed gas and hydrogen-fueled vehicles. Future enhancements will add features similar to a "check engine" light on a vehicle. Once installed, the system will ultimately be used to alert International Space Station crewmembers to critical structural instabilities, but will have little impact to missions otherwise. Diagnostic information could then be transmitted to experienced technicians on the ground in a timely manner to determine whether pressure vessels have been impacted, are structurally unsound, or can be safely used to complete the mission.

  20. Marine mammal tracks from two-hydrophone acoustic recordings made with a glider

    OpenAIRE

    Küsel, Elizabeth T.; Munoz, Tessa; Siderius, Martin; Mellinger, David K.; Heimlich, Sara

    2016-01-01

    A multinational oceanographic and acoustic sea experiment was carried out in the summer of 2014 off the western coast of the island of Sardinia, Mediterranean Sea. During this experiment, an underwater glider was evaluated as a potential tool for recording marine mammal sounds for population density estimation studies. To this end, an acoustic recording system was also tested, comprising two hydrophones connected to an off-the-shelf voice recorder installed inside the glider. A...

  1. Humanitarian mine detection by acoustic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Kercel, S.W.

    1998-03-01

    The JASON Committee at MITRE Corp. was tasked by DARPA to inquire into suitable technologies for humanitarian mine detection. Acoustic resonance was one of the very few technologies that the JASONs determined might be promising for the task, but was as yet unexplored at the time that they conducted their inquiry. The objective of this Seed Money investigation into acoustic resonance was to determine if it would be feasible to use acoustic resonance to provide an improvement to present methods for humanitarian mine detection. As detailed in this report, acoustic resonance methods do not appear to be feasible for this task. Although acoustic resonant responses are relatively easy to detect when they exist, they are very difficult to excite by the non-contact means that must be used for buried objects. Despite many different attempts, this research did not discover any practical means of using sound to excite resonant responses in objects known to have strong resonances. The shaker table experiments did see an effect that might be attributable to the resonance of the object under test, but the effect was weak, and exploited the a priori knowledge of the resonant frequency of the object under test to distinguish it from the background. If experiments that used objects known to have strong acoustic resonances produced such marginal results, this does not seem to be a practical method to detect objects with weak resonances or non-existent resonances. The results of this work contribute to the ORNL countermine initiative. ORNL is exploring several unconventional mine detection technologies, and is proposed to explore others. Since this research has discovered some major pitfalls in non-metallic mine detection, this experience will add realism to other strategies proposed for mine detection technologies. The experiment provided hands-on experience with inert plastic mines under field conditions, and gives ORNL additional insight into the problems of developing practical

  2. A new fire alarm system for electrical installations

    CERN Document Server

    Pietersen, A H

    1978-01-01

    Fires in electrical installations are considered to develop in four phases - initiation, smouldering, flame formation and heat development. Cables are among the more sensitive components, with working temperatures around 50 degrees C and fire detection at 70 degrees C. Conventional alarms include smoke detectors. The new technique described uses microcapsules containing powder forming a gas of the Freon type after diffusion. A typical microcapsule loses 4% per year and has a natural life of 10 years. Fabrication methods are described. Detection is by gas concentration, with a sensitivity of 1 to 10 ppm, or by acoustic methods with microphones to pick up the sound of fractures. Pressure/temperature characteristics of various types of Freon mixtures commercially available are given in graphical form.

  3. Acoustic comfort in eating establishments

    DEFF Research Database (Denmark)

    Svensson, David; Jeong, Cheol-Ho; Brunskog, Jonas

    2014-01-01

    The subjective concept of acoustic comfort in eating establishments has been investigated in this study. The goal was to develop a predictive model for the acoustic comfort, by means of simple objective parameters, while also examining which other subjective acoustic parameters could help explain...... the feeling of acoustic comfort. Through several layers of anal ysis, acoustic comfort was found to be rather complex, and could not be explained entirely by common subjective parameters such as annoyance, intelligibility or privacy. A predictive model for the mean acoustic comfort for an eating establishment...

  4. Phononic crystals and acoustic metamaterials

    Directory of Open Access Journals (Sweden)

    Ming-Hui Lu

    2009-12-01

    Full Text Available Phononic crystals have been proposed about two decades ago and some important characteristics such as acoustic band structure and negative refraction have stimulated fundamental and practical studies in acoustic materials and devices since then. To carefully engineer a phononic crystal in an acoustic “atom” scale, acoustic metamaterials with their inherent deep subwavelength nature have triggered more exciting investigations on negative bulk modulus and/or negative mass density. Acoustic surface evanescent waves have also been recognized to play key roles to reach acoustic subwavelength imaging and enhanced transmission.

  5. Comparison of Two High Intensity Acoustic Test Facilities

    Science.gov (United States)

    Launay, A.; Tadao Sakita, M.; Kim, Youngkey K.

    2004-08-01

    In two different countries, at the same period of time, the institutes in charge of the development of space activities have decided to extend their satellite integration and test center, and to implement a reverberant acoustic chamber. In Brazil the INPE laboratory (LIT : Laboratorio de Integracao e Testes) and in South Korea the KARI laboratory (SITC : Satellite Integration and Test Center) started their projects in July 2000 for the RATF (Reverberant Acoustic Test Facility) and in May 2001 for the HIAC (High Intensity Acoustic Chamber) respectively, writing the technical specifications. The kick-off meetings took place in December 2000 and in February 2002 and the opening ceremonies in December 19, 2002 in Brazil and in August 22, 2003 in Korea. This paper compares the two projects in terms of design choices, manufacturing processes, equipment installed and technical final characteristics.

  6. Supersymmetric heterotic string backgrounds

    NARCIS (Netherlands)

    Gran, U.; Papadopoulos, G.; Roest, D.; Cvetič, M.

    2007-01-01

    We present the main features of the solution of the gravitino and dilatino Killing spinor equations derived in hep-th/0510176 and hep-th/0703143 which have led to the classification of geometric types of all type I backgrounds. We then apply these results to the supersymmetric backgrounds of the het

  7. The role of classroom acoustics on vocal intensity regulation and speakers’ comfort

    OpenAIRE

    Pelegrin Garcia, David; Brunskog, Jonas; Poulsen, Torben

    2011-01-01

    Teachers are one of the professional groups with the highest risk of suffering from voice disorders. Teachers point out classroom acoustics among the potential hazards affecting their vocal health, together with air dryness, background noise, and other environmental factors. The present project has investigated the relationships between the classroom acoustic condition and teachers’ voice, focusing on their vocal intensity, and between the classroom acoustic condition and the sensation of aco...

  8. Experimental study of the acoustic characteristics of micro-perforated functional absorbers

    Institute of Scientific and Technical Information of China (English)

    WANG Jiqing; SONG Yongmin; SHENG Shengwo

    2005-01-01

    Micro-perforated panels have been widely used as fiber-free acoustical material for decades in the form of wall or ceiling covering with some air space behind. This paper presents the test study on the acoustical characteristics of two different types of functional absorbers,panel type and tube type, constructed with micro-perforated metal or PVC (polyvinyl chloride) sheets. Acoustical measurements of such functional absorbers in reverberation chamber demonstrate the merit of good absorption as expected. They are not only cost effective in construction and installation, but also appealing esthetically for architectural interior design.

  9. Wavefront Modulation and Subwavelength Diffractive Acoustics with an Acoustic Metasurface

    OpenAIRE

    Xie, Yangbo; Wang, Wenqi; Chen, Huanyang; Konneker, Adam; Popa, Bogdan-Ioan; Cummer, Steven A.

    2014-01-01

    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 as their electromagnetic counterparts remains challenging with traditional metamaterial design approaches. Here we present a desig...

  10. ACOUSTICS IN ARCHITECTURAL DESIGN, AN ANNOTATED BIBLIOGRAPHY ON ARCHITECTURAL ACOUSTICS.

    Science.gov (United States)

    DOELLE, LESLIE L.

    THE PURPOSE OF THIS ANNOTATED BIBLIOGRAPHY ON ARCHITECTURAL ACOUSTICS WAS--(1) TO COMPILE A CLASSIFIED BIBLIOGRAPHY, INCLUDING MOST OF THOSE PUBLICATIONS ON ARCHITECTURAL ACOUSTICS, PUBLISHED IN ENGLISH, FRENCH, AND GERMAN WHICH CAN SUPPLY A USEFUL AND UP-TO-DATE SOURCE OF INFORMATION FOR THOSE ENCOUNTERING ANY ARCHITECTURAL-ACOUSTIC DESIGN…

  11. Effects of boundary conditions on vibrating mode of acoustic logging dipole transducer

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Acoustic transducer is an important part of acoustic well logging tool. In this paper,ANSYS software package is used to design acoustic dipole transducer and simulate vibrating mode of the dipole transducer in different mechanical boundary conditions. The results show that boundary conditions influence the number of vibrating mode in the same frequency band and the frequency value of the same vibrating mode. Several acoustic dipole transducers are designed according to the results of numerical simulation and laboratory measurements. The basic frequency of vibrating mode of experi-ment has good agreement with that of simulation. The numerical simulation plays a good guidance role in designing,producing and correctly installing the acoustic dipole transducer.

  12. Practical acoustic emission testing

    CERN Document Server

    2016-01-01

    This book is intended for non-destructive testing (NDT) technicians who want to learn practical acoustic emission testing based on level 1 of ISO 9712 (Non-destructive testing – Qualification and certification of personnel) criteria. The essential aspects of ISO/DIS 18436-6 (Condition monitoring and diagnostics of machines – Requirements for training and certification of personnel, Part 6: Acoustic Emission) are explained, and readers can deepen their understanding with the help of practice exercises. This work presents the guiding principles of acoustic emission measurement, signal processing, algorithms for source location, measurement devices, applicability of testing methods, and measurement cases to support not only researchers in this field but also and especially NDT technicians.

  13. Passive broadband acoustic thermometry

    Science.gov (United States)

    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.

  14. Acoustics waves and oscillations

    CERN Document Server

    Sen, S.N.

    2013-01-01

    Parameters of acoustics presented in a logical and lucid style Physical principles discussed with mathematical formulations Importance of ultrasonic waves highlighted Dispersion of ultrasonic waves in viscous liquids explained This book presents the theory of waves and oscillations and various applications of acoustics in a logical and simple form. The physical principles have been explained with necessary mathematical formulation and supported by experimental layout wherever possible. Incorporating the classical view point all aspects of acoustic waves and oscillations have been discussed together with detailed elaboration of modern technological applications of sound. A separate chapter on ultrasonics emphasizes the importance of this branch of science in fundamental and applied research. In this edition a new chapter ''Hypersonic Velocity in Viscous Liquids as revealed from Brillouin Spectra'' has been added. The book is expected to present to its readers a comprehensive presentation of the subject matter...

  15. Acoustic detection of pneumothorax

    Science.gov (United States)

    Mansy, Hansen A.; Royston, Thomas J.; Balk, Robert A.; Sandler, Richard H.

    2003-04-01

    This study aims at investigating the feasibility of using low-frequency (pneumothorax detection were tested in dogs. In the first approach, broadband acoustic signals were introduced into the trachea during end-expiration and transmitted waves were measured at the chest surface. Pneumothorax was found to consistently decrease pulmonary acoustic transmission in the 200-1200-Hz frequency band, while less change was observed at lower frequencies (ppneumothorax states (pPneumothorax was found to be associated with a preferential reduction of sound amplitude in the 200- to 700-Hz range, and a decrease of sound amplitude variation (in the 300 to 600-Hz band) during the respiration cycle (pPneumothorax changed the frequency and decay rate of percussive sounds. These results imply that certain medical conditions may be reliably detected using appropriate acoustic measurements and analysis. [Work supported by NIH/NHLBI #R44HL61108.

  16. A Century of Acoustic Metrology

    DEFF Research Database (Denmark)

    Rasmussen, Knud

    1998-01-01

    The development in acoustic measurement technique over the last century is reviewed with special emphasis on the metrological aspect.......The development in acoustic measurement technique over the last century is reviewed with special emphasis on the metrological aspect....

  17. Advanced Active Acoustics Lab (AAAL)

    Data.gov (United States)

    Federal Laboratory Consortium — The Advanced Active Acoustics Lab (AAAL) is a state-of-the-art Undersea Warfare (USW) acoustic data analysis facility capable of both active and passive underwater...

  18. Speech recognition in natural background noise.

    Directory of Open Access Journals (Sweden)

    Julien Meyer

    Full Text Available In the real world, human speech recognition nearly always involves listening in background noise. The impact of such noise on speech signals and on intelligibility performance increases with the separation of the listener from the speaker. The present behavioral experiment provides an overview of the effects of such acoustic disturbances on speech perception in conditions approaching ecologically valid contexts. We analysed the intelligibility loss in spoken word lists with increasing listener-to-speaker distance in a typical low-level natural background noise. The noise was combined with the simple spherical amplitude attenuation due to distance, basically changing the signal-to-noise ratio (SNR. Therefore, our study draws attention to some of the most basic environmental constraints that have pervaded spoken communication throughout human history. We evaluated the ability of native French participants to recognize French monosyllabic words (spoken at 65.3 dB(A, reference at 1 meter at distances between 11 to 33 meters, which corresponded to the SNRs most revealing of the progressive effect of the selected natural noise (-8.8 dB to -18.4 dB. Our results showed that in such conditions, identity of vowels is mostly preserved, with the striking peculiarity of the absence of confusion in vowels. The results also confirmed the functional role of consonants during lexical identification. The extensive analysis of recognition scores, confusion patterns and associated acoustic cues revealed that sonorant, sibilant and burst properties were the most important parameters influencing phoneme recognition. . Altogether these analyses allowed us to extract a resistance scale from consonant recognition scores. We also identified specific perceptual consonant confusion groups depending of the place in the words (onset vs. coda. Finally our data suggested that listeners may access some acoustic cues of the CV transition, opening interesting perspectives for

  19. Cosmogenic Backgrounds to 0{\

    CERN Document Server

    :,; Auty, D J; Barbeau, P S; Beck, D; Belov, V; Breidenbach, M; Brunner, T; Burenkov, A; Cao, G F; Chambers, C; Cleveland, B; Coon, M; Craycraft, A; Daniels, T; Danilov, M; Daugherty, S J; Davis, J; Delaquis, S; Der Mesrobian-Kabakian, A; DeVoe, R; Didberidze, T; Dilling, J; Dolgolenko, A; Dolinski, M J; Dunford, M; Fairbank, W; Farine, J; Feldmeier, W; Feyzbakhsh, S; Fierlinger, P; Fudenberg, D; Gornea, R; Graham, K; Gratta, G; Hall, C; Herrin, S; Hughes, M; Jewell, M J; Johnson, A; Johnson, T N; Johnston, S; Karelin, A; Kaufman, L J; Killick, R; Koffas, T; Kravitz, S; Krücken, R; Kuchenkov, A; Kumar, K S; Leonard, D S; Licciardi, C; Lin, Y H; Ling, J; MacLellan, R; Marino, M G; Mong, B; Moore, D; Njoya, O; Nelson, R; Odian, A; Ostrovskiy, I; Piepke, A; Pocar, A; Prescott, C Y; Retière, F; Rowson, P C; Russell, J J; Schubert, A; Sinclair, D; Smith, E; Stekhanov, V; Tarka, M; Tolba, T; Tsang, R; Twelker, K; Vuilleumier, J -L; Waite, A; Walton, J; Walton, T; Weber, M; Wen, L J; Wichoski, U; Wood, J; Yang, L; Yen, Y -R; Zeldovich, O Ya

    2015-01-01

    As neutrinoless double-beta decay experiments become more sensitive and intrinsic radioactivity in detector materials is reduced, previously minor contributions to the background must be understood and eliminated. With this in mind, cosmogenic backgrounds have been studied with the EXO-200 experiment. Using the EXO-200 TPC, the muon flux (through a flat horizontal surface) underground at the Waste Isolation Pilot Plant (WIPP) has been measured to be {\\Phi} = 4.07 $\\pm$ 0.14 (sys) $\\pm$ 0.03 (stat) $\\times$ $10^{-7}$cm$^{-2}$ s$^{-1}$, with a vertical intensity of $I_{v}$ = 2.97$^{+0.14}_{-0.13}$ (sys) $\\pm$ 0.02 (stat) $\\times$ $10^{-7}$cm$^{-2}$ s$^{-1}$ sr$^{-1}$. Simulations of muon-induced backgrounds identified several potential cosmogenic radionuclides, though only 137Xe is a significant background for the 136Xe 0{\

  20. Comparative environmental assessment of unconventional power installations

    Science.gov (United States)

    Sosnina, E. N.; Masleeva, O. V.; Kryukov, E. V.

    2015-08-01

    Procedure of the strategic environmental assessment of the power installations operating on the basis of renewable energy sources (RES) was developed and described. This procedure takes into account not only the operational process of the power installation but also the whole life cycles: from the production and distribution of power resources for manufacturing of the power installations to the process of their recovery. Such an approach gives an opportunity to make a more comprehensive assessment of the influence of the power installations on environments and may be used during adaptation of the current regulations and development of new regulations for application of different types of unconventional power installations with due account of the ecological factor. Application of the procedure of the integrated environmental assessment in the context of mini-HPP (Hydro Power Plant); wind, solar, and biogas power installations; and traditional power installation operating natural gas was considered. Comparison of environmental influence revealed advantages of new energy technologies compared to traditional ones. It is shown that solar energy installations hardly pollute the environment during operation, but the negative influence of the mining operations and manufacturing and utilization of the materials used for solar modules is maximum. Biogas power installations are on the second place as concerns the impact on the environment due to the considerable mass of the biogas installation and gas reciprocating engine. The minimum impact on the environment is exerted by the mini-HPP. Consumption of material and energy resources for the production of the traditional power installation is less compared to power installations on RES; however, this factor incomparably increases when taking into account the fuel extraction and transfer. The greatest impact on the environment is exerted by the operational process of the traditional power installations.

  1. Densitometry By Acoustic Levitation

    Science.gov (United States)

    Trinh, Eugene H.

    1989-01-01

    "Static" and "dynamic" methods developed for measuring mass density of acoustically levitated solid particle or liquid drop. "Static" method, unknown density of sample found by comparison with another sample of known density. "Dynamic" method practiced with or without gravitational field. Advantages over conventional density-measuring techniques: sample does not have to make contact with container or other solid surface, size and shape of samples do not affect measurement significantly, sound field does not have to be know in detail, and sample can be smaller than microliter. Detailed knowledge of acoustic field not necessary.

  2. Acoustic classification of dwellings

    DEFF Research Database (Denmark)

    Berardi, Umberto; Rasmussen, Birgit

    2014-01-01

    insulation performance, national schemes for sound classification of dwellings have been developed in several European countries. These schemes define acoustic classes according to different levels of sound insulation. Due to the lack of coordination among countries, a significant diversity in terms...... of descriptors, number of classes, and class intervals occurred between national schemes. However, a proposal “acoustic classification scheme for dwellings” has been developed recently in the European COST Action TU0901 with 32 member countries. This proposal has been accepted as an ISO work item. This paper...

  3. Strong acoustic wave action

    Science.gov (United States)

    Gokhberg, M. B.

    1983-07-01

    Experiments devoted to acoustic action on the atmosphere-magnetosphere-ionosphere system using ground based strong explosions are reviewed. The propagation of acoustic waves was observed by ground observations over 2000 km in horizontal direction and to an altitude of 200 km. Magnetic variations up to 100 nT were detected by ARIEL-3 satellite near the epicenter of the explosion connected with the formation of strong field aligned currents in the magnetosphere. The enhancement of VLF emission at 800 km altitude is observed.

  4. Structural Acoustics and Vibrations

    Science.gov (United States)

    Chaigne, Antoine

    This structural chapter is devoted to vibrations of structures and to their coupling with the acoustic field. Depending on the context, the radiated sound can be judged as desirable, as is mostly the case for musical instruments, or undesirable, like noise generated by machinery. In architectural acoustics, one main goal is to limit the transmission of sound through walls. In the automobile industry, the engineers have to control the noise generated inside and outside the passenger compartment. This can be achieved by means of passive or active damping. In general, there is a strong need for quieter products and better sound quality generated by the structures in our daily environment.

  5. Zambia Country Background Report

    DEFF Research Database (Denmark)

    Hampwaye, Godfrey; Jeppesen, Søren; Kragelund, Peter

    This paper provides background data and general information for the Zambia studies focusing on local food processing sub­‐sector; and the local suppliers to the mines as part of the SAFIC project (Successful African Firms and Institutional Change).......This paper provides background data and general information for the Zambia studies focusing on local food processing sub­‐sector; and the local suppliers to the mines as part of the SAFIC project (Successful African Firms and Institutional Change)....

  6. On Background Independence

    OpenAIRE

    Anderson, Edward

    2013-01-01

    This paper concerns what Background Independence itself is (as opposed to some particular physical theory that is background independent). The notions presented mostly arose from a layer-by-layer analysis of the facets of the Problem of Time in Quantum Gravity. Part of this coincides with two relational postulates which are thus identified as classical precursors of two of the facets of the Problem of Time. These are furthemore tied to the forms of each of the GR Hamiltonian and momentum cons...

  7. Thermodynamics of acoustic black holes in two dimensions

    CERN Document Server

    Zhang, Baocheng

    2016-01-01

    It is well-known that the thermal Hawking-like radiation can be emitted from the acoustic horizon, but the thermodynamic-like understanding for acoustic black holes was rarely made. In this paper, we will show that the kinematic connection can lead to the dynamic connection at the horizon between the fluid and gravitational models in two dimension, which implies that there exists the thermodynamic-like description for acoustic black holes. Then, we discuss the first law of thermodynamics for the acoustic black hole via an intriguing connection between the gravitational-like dynamics of the acoustic horizon and thermodynamics, as well-built in the gravity theory. We obtain a universal form for the entropy of acoustic black holes, which has an interpretation similar to the entropic gravity. We also discuss the specific heat, and find that the derivative of the velocity of background fluid can be regarded as a novel acoustic analogue of the two-dimensional dilaton potential, which interprets why the two-dimensio...

  8. Meals on Wheels? A Decade of Megafaunal Visual and Acoustic Observations from Offshore Oil & Gas Rigs and Platforms in the North and Irish Seas

    OpenAIRE

    Todd, Victoria Louise Georgia; Warley, Jane Clare; Todd, Ian Boyer

    2016-01-01

    A decade of visual and acoustic detections of marine megafauna around offshore Oil & Gas (O&G) installations in the North and Irish Seas are presented. Marine megafauna activity was monitored visually and acoustically by Joint Nature Conservation Committee (JNCC) qualified and experienced Marine Mammal Observers (MMO) and Passive Acoustic Monitoring (PAM) Operators respectively, with real-time towed PAM in combination with industry standard software, PAMGuard. Monitoring was performed during ...

  9. Variable-Position Acoustic Levitation

    Science.gov (United States)

    Barmatz, M. B.; Stoneburner, J. D.; Jacobi, N.; Wang, T. G.

    1983-01-01

    Method of acoustic levitation supports objects at positions other than acoustic nodes. Acoustic force is varied so it balances gravitational (or other) force, thereby maintaining object at any position within equilibrium range. Levitation method applicable to containerless processing. Such objects as table-tennis balls, hollow plastic spheres, and balsa-wood spheres levitated in laboratory by new method.

  10. ID Barrel installed in cryostat

    CERN Multimedia

    Apsimon, R.; Romaniouk, A.

    Wednesday 23rd August was a memorable day for the Inner Detector community as they witnessed the transport and installation of the central part of the inner detector (ID-barrel) into the ATLAS detector. Many members of the collaboration gathered to witness this moment at Point 1. After years of design, construction and commissioning, the outer two detectors (TRT and SCT) of the ID barrel were moved from the SR1 cleanroom to the ATLAS cavern. The barrel was moved across the car park from building 2175 to SX1. Although only a journey of about 100 metres, this required weeks of planning and some degree of luck as far as the weather was concerned. Accelerometers were fitted to the barrel to provide real-time monitoring and no values greater than 0.1 g were recorded, fully satisfying the transport specification for this extremely precise and fragile detector. Muriel, despite her fear of heights, bravely volunteered to keep a close eye on the detector. Swapping cranes to cross the entire parking lot, while Mur...

  11. Study of nonlinear ion- and electron-acoustic waves in multi-component space plasmas

    Directory of Open Access Journals (Sweden)

    G. S. Lakhina

    2008-11-01

    Full Text Available Large amplitude ion-acoustic and electron-acoustic waves in an unmagnetized multi-component plasma system consisting of cold background electrons and ions, a hot electron beam and a hot ion beam are studied using Sagdeev pseudo-potential technique. Three types of solitary waves, namely, slow ion-acoustic, ion-acoustic and electron-acoustic solitons are found provided the Mach numbers exceed the critical values. The slow ion-acoustic solitons have the smallest critical Mach numbers, whereas the electron-acoustic solitons have the largest critical Mach numbers. For the plasma parameters considered here, both type of ion-acoustic solitons have positive potential whereas the electron-acoustic solitons can have either positive or negative potential depending on the fractional number density of the cold electrons relative to that of the ions (or total electrons number density. For a fixed Mach number, increases in the beam speeds of either hot electrons or hot ions can lead to reduction in the amplitudes of the ion-and electron-acoustic solitons. However, the presence of hot electron and hot ion beams have no effect on the amplitudes of slow ion-acoustic modes. Possible application of this model to the electrostatic solitary waves (ESWs observed in the plasma sheet boundary layer is discussed.

  12. Design considerations and sensitivity estimates for an acoustic neutrino detector

    CERN Document Server

    Karg, T; Graf, K; Hoessl, J; Kappes, A; Katz, U; Lahmann, R; Naumann, C; Salomon, K; Karg, Timo; Anton, Gisela; Graf, Kay; Hoessl, Juergen; Kappes, Alexander; Katz, Uli; Lahmann, Robert; Naumann, Christopher; Salomon, Karsten

    2005-01-01

    We present a Monte Carlo study of an underwater neutrino telescope based on the detection of acoustic signals generated by neutrino induced cascades. This provides a promising approach to instrument large detector volumes needed to detect the small flux of cosmic neutrinos at ultra-high energies (E > 1 EeV). Acoustic signals are calculated based on the thermo-acoustic model. The signal is propagated to the sensors taking frequency dependent attenuation into account, and detected using a threshold trigger, where acoustic background is included as an effective detection threshold. A simple reconstruction algorithm allows for the determination of the cascade direction and energy. Various detector setups are compared regarding their effective volumes. Sensitivity estimates for the diffuse neutrino flux are presented.

  13. Acoustic Characteristics of Ataxic Speech in Japanese Patients with Spinocerebellar Degeneration (SCD)

    Science.gov (United States)

    Ikui, Yukiko; Tsukuda, Mamoru; Kuroiwa, Yoshiyuki; Koyano, Shigeru; Hirose, Hajime; Taguchi, Takahide

    2012-01-01

    Background: In English- and German-speaking countries, ataxic speech is often described as showing scanning based on acoustic impressions. Although the term "scanning" is generally considered to represent abnormal speech features including prosodic excess or insufficiency, any precise acoustic analysis of ataxic speech has not been performed in…

  14. From Architectural Acoustics to Acoustical Architecture Using Computer Simulation

    DEFF Research Database (Denmark)

    Schmidt, Anne Marie Due; Kirkegaard, Poul Henning

    2005-01-01

    Architectural acoustics design has in the past been based on simple design rules. However, with a growing complexity in architectural acoustics and the emergence of room acoustic simulation programmes with considerable potential, it is now possible to subjectively analyse and evaluate acoustic...... properties prior to the actual construction of a building. With the right tools applied, acoustic design can become an integral part of the architectural design process. The aim of this paper is to investigate the field of application that an acoustic simulation programme can have during an architectural...... acoustic design process and to set up a strategy to develop future programmes. The emphasis is put on the first three out of four phases in the working process of the architect and a case study is carried out in which each phase is represented by typical results ? as exemplified with reference...

  15. Modern electrical installation for craft students

    CERN Document Server

    Scaddan, Brian

    2013-01-01

    Modern Electrical Installation for Craft Students, Volume 2, Third Edition discusses several topics concerning electrical installations. The book is comprised of eight chapters that deal with craft theory, associated subjects, and electrical industries. Chapter 1 covers inductors and inductance, while Chapter 2 tackles capacitors and capacitance. Chapter 3 deals with inductance and capacitance in installation work. The book also discusses cells, batteries, and transformers. The electrical industries, control and earthing, and testing are also dealt with. The last chapter discusses the basic el

  16. Installation NR-31R for neutron radiography

    International Nuclear Information System (INIS)

    NR-31R installation, intended for neutron radiography of extended radioactive items using horizontal neutron beam from the nuclear reactor of WWER-type, is described. The installation is located directly in the reactor hall. It comprises the following main units: collimator, radiographic chamber, two containers (upper and bottom), neutron beam trap, distance and local control pannels. Obtaining neutron images of the controlled items is possible at NR-31R installation both by the method of direct exposure, and by the transfer method

  17. Installation of Shimming Bars for CYCIAE-100

    Institute of Scientific and Technical Information of China (English)

    LV; Yin-long; WANG; Zhen-hui; ZHONG; Jun-qing; LIU; Geng-shou

    2012-01-01

    <正>The 100 MeV high intensity proton cyclotron, CYCIAE-100, is the most critical equipment of the BRIF project at CIAE. The shimming bars are used to get the isochronous magnetic field. In the process of magnetic mapping and shimming, the bars should be repeated the installed and disassembly for about 10 times. Each time the installation precision must be ensured. The bars installation schedule and quality are directly related to the BRIF project progress.

  18. The year 2000 passage on nuclear installations

    International Nuclear Information System (INIS)

    The year 2000 impact on the nuclear installations must be carefully treated. Since 1998 the operating have been examine by the safety authorities and all seem ready to prevent the year 2000 risk. The three following examples are described: the EDF (Electricite De France) reactors, the fuel cycle installations, the experimental and research reactors laboratories and other installations of the Cea. (A.L.B.)

  19. An acoustical performance space in ancient India: The Rani Gumpha

    Science.gov (United States)

    Ault, C. Thomas; Manthravadi, Umashankar

    2002-11-01

    The Rani Gumpha, or Queen's Cavern, was built by artist-king of Kalinga, Kharavela (ca. 200-100 B.C.). It is a rock cut structure, carved into Udayagiri hill. As in ancient Greek and Roman theaters, the entire performance space of the Rani Gumpa is backed by a decorated facade, and it is remarkably similar to Greek theaters of the Hellenistic period, having both an upper and lower level for playing. There are acoustical chambers behind each level as well as on either side, and a special ''cantor's chamber'' stage left on the lower level. The effect on the voice is astonishing. This is a rock cut acoustical installation analogous to that described by Vitruvius in Book V, Chaps. 5 and 8, of his de Architectura, where he speaks of vessels placed in Greek and Roman theaters for the same purpose. We have created a computerized model of the Ranim Gumpha, using CATT Acoustic. We have taken acoustic measurements of the site, using Aurora Sofware package. Our results indicate that the Rani Gumpha is an acoustical performance site, sharing characteristics of the classical Greek and Roman theaters of approximately the same period.

  20. Evoked acoustic emission

    DEFF Research Database (Denmark)

    Elberling, C; Parbo, J; Johnsen, N J;

    1985-01-01

    Stimulated acoustic emissions were recorded in response to tonal stimuli at 60 dB p.e. SPL in a small group of normal-hearing adults. Power spectral analysis reveals that the evoked activity from each ear contains energy in preferential frequency bands and the change of stimulus frequency has only...

  1. Surface Acoustic Wave Devices

    DEFF Research Database (Denmark)

    Dühring, Maria Bayard

    The work of this project is concerned with the simulation of surface acoustic waves (SAW) and topology optimization of SAW devices. SAWs are elastic vibrations that propagate along a material surface and are extensively used in electromechanical filters and resonators in telecommunication. A new...

  2. Portable acoustic myography

    DEFF Research Database (Denmark)

    Harrison, Adrian Paul; Danneskiold-Samsøe, Bente; Bartels, Else Marie

    2013-01-01

    Muscle sound gives a local picture of muscles involved in a particular movement and is independent of electrical signals between nerve and muscle. Sound recording (acoustic myography) is a well-known noninvasive technique that has suffered from not being easily applicable, as well as not being ab...

  3. Unitarity and singular backgrounds

    CERN Document Server

    Brouzakis, Nikos

    2013-01-01

    We compute the graviton Kaluza-Klein spectrum on a gravity-dilaton background with a naked singularity for all possible boundary conditions at the singularity which are consistent with unitary evolution. We apply methods from non-relativistic quantum mechanics with singular Schr\\"{o}dinger potentials. In general the spectrum contains a tachyon, a sign of instability. Only for a particular boundary condition at the singularity the spectrum is free of tachyons. In this case the lowest-lying graviton mode is massless. We argue that this result will also hold for other backgrounds with similar geometry near the curvature singularity. We complete our study with a brief discussion on radion perturbations and Higgs mechanism on this singular background.

  4. Exploring String Theory Backgrounds

    CERN Document Server

    Williams, B P

    2004-01-01

    This thesis examines phenomenological and theoretical questions by exploring string theoretic backgrounds. Part I focuses on cosmology. First we propose that the induced metric along a brane moving through a curved bulk may be interpreted as the cosmology of the brane universe, providing a resolution to the apparent cosmological singularity on the brane. We then look at various decay channels of the certain meta-stable de Sitter vacua and show that there exist NS5-brane meditated decays which are much faster than decays to decompactification. Part II discusses a new class of nongeometric vacua in string theory. These backgrounds may be described locally as T2 fibrations. By enlarging the monodromy group of the fiber to include perturbative stringy duality symmetries we are able to explicitly construct nongeometric backgrounds.

  5. Simulating acoustic waves in spotted stars

    CERN Document Server

    Papini, Emanuele; Gizon, Laurent; Hanasoge, Shravan M

    2015-01-01

    Acoustic modes of oscillation are affected by stellar activity, however it is unclear how starspots contribute to these changes. Here we investigate the non-magnetic effects of starspots on global modes with angular degree $\\ell \\leq 2$ in highly active stars, and characterize the spot seismic signature on synthetic light curves. We perform 3D time-domain simulations of linear acoustic waves to study their interaction with a model starspot. We model the spot as a 3D change in the sound speed stratification with respect to a convectively stable stellar background, built from solar Model S. We perform a parametric study by considering different depths and perturbation amplitudes. Exact numerical simulations allow investigation of the wavefield-spot interaction beyond first order perturbation theory. The interaction of the axisymmetric modes with the starspot is strongly nonlinear. As mode frequency increases, the frequency shifts for radial modes exceed the value predicted by linear theory, while the shifts for...

  6. Summary: Acoustic Detection of EHE Neutrinos

    CERN Document Server

    Vandenbroucke, J

    2006-01-01

    Neutrino astronomy was initiated primarily to search for TeV to PeV neutrinos from Active Galactic Nuclei, and the optical Cherenkov technique is well suited for this energy range. Interest has grown recently in detecting EeV neutrinos, particularly the ``cosmogenic'' neutrinos produced during propagation of ultra-high-energy cosmic rays (UHECR) through the microwave background radiation. These neutrinos could be a powerful tool both to resolve the mystery of the UHECR sources and to test fundamental physics at the $\\sim$100 TeV scale. The optical technique is not cost effective at these energies and newer techniques such as radio and acoustic detection are necessary. Accelerator experiments have confirmed the production of both types of signals from high-energy showers in various media, and quantitative measurements have confirmed theoretical descriptions of the signal strength, frequency content and pulse shape. While radio experiments have set the strongest limits so far, the acoustic method could contribu...

  7. After Acoustic Peaks What's Next in CMB?

    CERN Document Server

    Cooray, A R

    2002-01-01

    The advent of high signal-to-noise cosmic microwave background (CMB) anisotropy experiments has allowed detailed studies on the power spectrum of temperature fluctuations. The existence of acoustic oscillations in the anisotropy power spectrum is now established with the detection of the first two, and possibly the third, peaks. Beyond the acoustic peak structure, we consider cosmological and astrophysical information that can be extracted by pushing anisotropy observations to fine angular scales with higher resolution instruments. At small scales, a variety of contributions allow the use of CMB photons as a probe of the large scale structure: we outline possible studies related to understanding detailed physical properties such as the distribution of dark matter, baryons and pressure, and ways to measure the peculiar, transverse and rotational velocities of virialized halos such as galaxy clusters. Beyond the temperature, we consider several useful aspects of the CMB polarization and comment on an ultimate g...

  8. Holograms for acoustics

    Science.gov (United States)

    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.

  9. Controlling sound with acoustic metamaterials

    DEFF Research Database (Denmark)

    Cummer, Steven A. ; Christensen, Johan; Alù, Andrea

    2016-01-01

    Acoustic metamaterials can manipulate and control sound waves in ways that are not possible in conventional materials. Metamaterials with zero, or even negative, refractive index for sound offer new possibilities for acoustic imaging and for the control of sound at subwavelength scales....... The combination of transformation acoustics theory and highly anisotropic acoustic metamaterials enables precise control over the deformation of sound fields, which can be used, for example, to hide or cloak objects from incident acoustic energy. Active acoustic metamaterials use external control to create......-scale metamaterial structures and converting laboratory experiments into useful devices. In this Review, we outline the designs and properties of materials with unusual acoustic parameters (for example, negative refractive index), discuss examples of extreme manipulation of sound and, finally, provide an overview...

  10. Low background screening capability in the UK

    International Nuclear Information System (INIS)

    Low background rare event searches in underground laboratories seeking observation of direct dark matter interactions or neutrino-less double beta decay have the potential to profoundly advance our understanding of the physical universe. Successful results from these experiments depend critically on construction from extremely radiologically clean materials and accurate knowledge of subsequent low levels of expected background. The experiments must conduct comprehensive screening campaigns to reduce radioactivity from detector components, and these measurements also inform detailed characterisation and quantification of background sources and their impact, necessary to assign statistical significance to any potential discovery. To provide requisite sensitivity for material screening and characterisation in the UK to support our rare event search activities, we have re-developed our infrastructure to add ultra-low background capability across a range of complementary techniques that collectively allow complete radioactivity measurements. Ultra-low background HPGe and BEGe detectors have been installed at the Boulby Underground Laboratory, itself undergoing substantial facility re-furbishment, to provide high sensitivity gamma spectroscopy in particular for measuring the uranium and thorium decay series products. Dedicated low-activity mass spectrometry instrumentation has been developed at UCL for part per trillion level contaminant identification to complement underground screening with direct U and Th measurements, and meet throughput demands. Finally, radon emanation screening at UCL measures radon background inaccessible to gamma or mass spectrometry techniques. With this new capability the UK is delivering half of the radioactivity screening for the LZ dark matter search experiment

  11. Low background screening capability in the UK

    Energy Technology Data Exchange (ETDEWEB)

    Ghag, Chamkaur [University College London, Department of Physics and Astronomy, Gower Street, London WC1E 6BT (United Kingdom)

    2015-08-17

    Low background rare event searches in underground laboratories seeking observation of direct dark matter interactions or neutrino-less double beta decay have the potential to profoundly advance our understanding of the physical universe. Successful results from these experiments depend critically on construction from extremely radiologically clean materials and accurate knowledge of subsequent low levels of expected background. The experiments must conduct comprehensive screening campaigns to reduce radioactivity from detector components, and these measurements also inform detailed characterisation and quantification of background sources and their impact, necessary to assign statistical significance to any potential discovery. To provide requisite sensitivity for material screening and characterisation in the UK to support our rare event search activities, we have re-developed our infrastructure to add ultra-low background capability across a range of complementary techniques that collectively allow complete radioactivity measurements. Ultra-low background HPGe and BEGe detectors have been installed at the Boulby Underground Laboratory, itself undergoing substantial facility re-furbishment, to provide high sensitivity gamma spectroscopy in particular for measuring the uranium and thorium decay series products. Dedicated low-activity mass spectrometry instrumentation has been developed at UCL for part per trillion level contaminant identification to complement underground screening with direct U and Th measurements, and meet throughput demands. Finally, radon emanation screening at UCL measures radon background inaccessible to gamma or mass spectrometry techniques. With this new capability the UK is delivering half of the radioactivity screening for the LZ dark matter search experiment.

  12. Low background screening capability in the UK

    Science.gov (United States)

    Ghag, Chamkaur

    2015-08-01

    Low background rare event searches in underground laboratories seeking observation of direct dark matter interactions or neutrino-less double beta decay have the potential to profoundly advance our understanding of the physical universe. Successful results from these experiments depend critically on construction from extremely radiologically clean materials and accurate knowledge of subsequent low levels of expected background. The experiments must conduct comprehensive screening campaigns to reduce radioactivity from detector components, and these measurements also inform detailed characterisation and quantification of background sources and their impact, necessary to assign statistical significance to any potential discovery. To provide requisite sensitivity for material screening and characterisation in the UK to support our rare event search activities, we have re-developed our infrastructure to add ultra-low background capability across a range of complementary techniques that collectively allow complete radioactivity measurements. Ultra-low background HPGe and BEGe detectors have been installed at the Boulby Underground Laboratory, itself undergoing substantial facility re-furbishment, to provide high sensitivity gamma spectroscopy in particular for measuring the uranium and thorium decay series products. Dedicated low-activity mass spectrometry instrumentation has been developed at UCL for part per trillion level contaminant identification to complement underground screening with direct U and Th measurements, and meet throughput demands. Finally, radon emanation screening at UCL measures radon background inaccessible to gamma or mass spectrometry techniques. With this new capability the UK is delivering half of the radioactivity screening for the LZ dark matter search experiment.

  13. Acoustic anisotropic wavefields through perturbation theory

    KAUST Repository

    Alkhalifah, Tariq Ali

    2013-09-01

    Solving the anisotropic acoustic wave equation numerically using finite-difference methods introduces many problems and media restriction requirements, and it rarely contributes to the ability to resolve the anisotropy parameters. Among these restrictions are the inability to handle media with η<0 and the presence of shear-wave artifacts in the solution. Both limitations do not exist in the solution of the elliptical anisotropic acoustic wave equation. Using perturbation theory in developing the solution of the anisotropic acoustic wave equation allows direct access to the desired limitation-free solutions, that is, solutions perturbed from the elliptical anisotropic background medium. It also provides a platform for parameter estimation because of the ability to isolate the wavefield dependency on the perturbed anisotropy parameters. As a result, I derive partial differential equations that relate changes in the wavefield to perturbations in the anisotropy parameters. The solutions of the perturbation equations represented the coefficients of a Taylor-series-type expansion of the wavefield as a function of the perturbed parameter, which is in this case η or the tilt of the symmetry axis. The expansion with respect to the symmetry axis allows use of an acoustic transversely isotropic media with a vertical symmetry axis (VTI) kernel to estimate the background wavefield and the corresponding perturbation coefficients. The VTI extrapolation kernel is about one-fourth the cost of the transversely isotropic model with a tilt in the symmetry axis kernel. Thus, for a small symmetry axis tilt, the cost of migration using a first-order expansion can be reduced. The effectiveness of the approach was demonstrated on the Marmousi model.

  14. Towards Acoustic Detection of UHE Neutrinos in the Mediterranean Sea - The AMADEUS Project in ANTARES

    CERN Document Server

    Graf, K; Hoessl, J; Kappes, A; Katz, U F; Lahmann, R; Naumann, C; Salomon, K

    2007-01-01

    The acoustic detection method is a promising option for future neutrino telescopes operating in the ultra-high energy regime. It utilises the effect that a cascade evolving from a neutrino interaction generates a sound wave, and is applicable in different target materials like water, ice and salt. Described here are the developments in and the plans for the research on acoustic particle detection in water performed by the ANTARES group at the University of Erlangen within the framework of the ANTARES experiment in the Mediterranean Sea. A set of acoustic sensors will be integrated into this optical neutrino telescope to test acoustic particle detection methods and perform background studies.

  15. Backgrounded but not peripheral

    DEFF Research Database (Denmark)

    Hovmark, Henrik

    2013-01-01

    -cultural construction of identity, and, as a matter of fact, that their role might be quite important. I argue that the DDAs are backgrounded but not peripheral, i.e. marginal or insignificant. And I introduce the notion of “contextualization cue” in this argument (Levinson, 2003a, Gumperz, 1992)....

  16. China: Background Notes Series.

    Science.gov (United States)

    Reams, Joanne Reppert

    Concise background information on the People's Republic of China is provided. The publication begins with a profile of the country, outlining the people, geography, economy, and membership in international organizations. The bulk of the document then discusses in more detail China's people, geography, history, government, education, economy, and…

  17. Local microwave background radiation

    OpenAIRE

    Soares, Domingos

    2006-01-01

    An inquiry on a possible local origin for the Microwave Background Radiation is made. Thermal MBR photons are contained in a system called {\\it magnetic bottle} which is due to Earth magnetic field and solar wind particles, mostly electrons. Observational tests are anticipated.

  18. Public perception of nuclear installations

    International Nuclear Information System (INIS)

    The key for nuclear renaissance is public acceptance. Facing energetic needs that occur around the world and lack of resources, the work of characterizing and proposing new models to represent public opinion is extremely important to all stakeholders. Even though public opinion's study on risks is relatively recent, may approaches of this subject have been suggested and presented, especially for the topic of perceptions on nuclear installations. Actual definitions on risk exist between objective and subjective models, that reflect opinions of lay public and experts. Strategies on communications with the public may be evaluated from many developed models, and its results may be registered. The use of structural models may present an exploratory character as well as confirmatory theories, as an adequate tool for the development of studies on public perception. In this work, a structural model is presented from data obtained in a previous report, and added to data collected before and after the Fukushima nuclear accident, in Japan. The effects developed from this accident offered a unique opportunity to study public opinion through the effects of a serious nuclear accident and its effects on risk communications. Aside, this work attempted to check the structural model according with obtained results, in order to sustain a constant improvement of the working tools. Yet, a comparison between data according to experts' respondents and lay public ones as well as a comparison among different students before and after a visit to nuclear station is considered. Obtained data for the structural models has been applied for on a structural model and analyzed by structural correlation matrix, latent variable structural coefficients and R2 values. Results indicate that public opinion maintains its rejection on nuclear energy and the perception of benefits, facing perceived risks before the accident, has diminished. A new model that included a latent variable for corresponding

  19. Back-reaction effects in acoustic black holes

    CERN Document Server

    Fagnocchi, S

    2006-01-01

    Acoustic black holes are very interesting non-gravitational objects which can be described by the geometrical formalism of General Relativity. These models can be useful to experimentally test effects otherwise undetectable, as for example the Hawking radiation. The back-reaction effects on the background quantities induced by the analogue Hawking radiation could be the key to indirectly observe it. We briefly show how this analogy works and derive the backreaction equations for the linearized quantum fluctuations in the background of an acoustic black hole. A first order in hbar solution is given in the near horizon region. It indicates that acoustic black holes, unlike Schwarzschild ones, get cooler as they radiate phonons. They show remarkable analogies with near-extremal Reissner-Nordstrom black holes.

  20. IMIS: Integrated Marine Installation System for offshore turbines

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    The report describes a feasibility study on the Integrated Marine Installation System for offshore wind turbines. The aspects covered are (1) Background and why the study is required; (2) Aims and objectives of the project; (3) Summary of methods adopted; (4) Design criteria according to the area for deployment; (5) Conclusions and recommendations. The ultimate goal will be to install and secure the wind turbine in position using an integrated approach to avoid using lifting vessels. To date, an initial feasibility study has been carried out where four different concepts were considered. The next phase of the project will be to address a number of possible risks and constraints before the chosen concept can be demonstrated to be viable. The work is being carried out by Setech Ltd, Armstrong Technology Associates Ltd and Smith Rea Energy Ltd for the DTI.

  1. High Voltage Installation of PS Linac 1 Preinjector

    CERN Multimedia

    1974-01-01

    The high-voltage installation of the linac 1 preinjector in its house-sized Faraday cage. Originally driven by a 520 kV Cockcroft-Walton generator, at the time of this picture the HV came from a 520 kV SAMES generator. The column in the front carries a capacitor. The cubicle in the right background is the electronics platform (see 7403120). The round structure at left houses the ion source, from where the protons (and sometimes other ions), electrostatically accelerated to 520 keV, enter the Alvarez structure of linac 1, to be accelerated to 50 MeV. Jean-Luc Vallet is busy with servicing the installation. See also 7403064X, 7403066X.

  2. Attenuation of FJ44 Turbofan Engine Noise with a Foam-Metal Liner Installed Over-the-Rotor

    Science.gov (United States)

    Sutliff, Daniel L.; Elliott, Dave M.; Jones, Michael G.; Hartley, Thomas C.

    2009-01-01

    A Williams International FJ44-3A 3000-lb thrust class turbofan engine was used as a demonstrator for a Foam-Metal Liner (FML) installed in close proximity to the fan. Two FML designs were tested and compared to the hardwall baseline. Traditional single degree-of-freedom liner designs were also evaluated to provide a comparison. Farfield acoustic levels and limited engine performance results are presented in this paper. The results show that the FML achieved up to 5 dB Acoustic Power Level (PWL) overall attenuation in the forward quadrant, equivalent to the traditional liner design. An earlier report presented the test set-up and conditions.

  3. Technologies for placing of underground installations

    OpenAIRE

    Doneva, Nikolinka; Despodov, Zoran; Mirakovski, Dejan; Hadzi-Nikolova, Marija

    2014-01-01

    In urban communities often there is a need to change existing underground installations or placing new ones. This paper will discuss two technologies for placing underground installations including: classic and contemporary technology (technology with mechanical excavation). For each of these two technologies will be given advantages and disadvantages, as well as experiences from their application.

  4. 46 CFR 119.310 - Installations.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Installations. 119.310 Section 119.310 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS CARRYING MORE THAN 150 PASSENGERS OR WITH OVERNIGHT ACCOMMODATIONS FOR MORE THAN 49 PASSENGERS MACHINERY INSTALLATION...

  5. Installation Service - Changes in opening hours

    CERN Multimedia

    GS Department

    2010-01-01

    For organizational matters, please note that, as from 15 March 2010, the Installation Service will have wen opening hours. The new schedule will be from 14:00 to 17:00 (Monday to Friday). Contact persons are: Martine Briant, Karine Robert and Claudia Bruggmann. The office address remains 73-3-014. Installation Service

  6. A Hadron Radiation Installation and Verification Method

    NARCIS (Netherlands)

    Beekman, F.J.; Bom, V.R.

    2013-01-01

    A hadron radiation installation adapted to subject a target to irradiation by a hadron radiation beam, said installation comprising: - a target support configured to support, preferably immobilize, a target: - a hadron radiation apparatus adapted to emit a hadron radiation beam along a beam axis to

  7. ATLAS semiconductor tracker installed into its barrel

    CERN Multimedia

    Maximilien Brice

    2005-01-01

    The ATLAS silicon tracker is installed in the silicon tracker barrel. Absolute precision was required in this operation to ensure that the tracker was inserted without damage through minimal clearance. The installation was performed in a clean room on the CERN site so that no impurities in the air would contaminate the tracker's systems.

  8. Diagnosing the Bottom of the Vertical Tank, a Device Based on the Phased Acoustic Gratings

    Science.gov (United States)

    Bezborodov, Yu; Selsky, A.; Lysyannikova, N.; Kravtsova, Ye; Lysyannikov, A.; Shram, V.; Kaiser, Yu; Merko, M.

    2016-06-01

    This paper presents a decision on the creation of a specialized low-frequency flaw detector operating on acoustic phased arrays. A defectoscope will solve the problem of oil leakage through diagnostics of installation or operational defects of the bottom base metal sheets that are difficult to detect by conventional methods of testing due to a large area of the object.

  9. Computer programs for forward and inverse modeling of acoustic and electromagnetic data

    Science.gov (United States)

    Ellefsen, Karl J.

    2011-01-01

    A suite of computer programs was developed by U.S. Geological Survey personnel for forward and inverse modeling of acoustic and electromagnetic data. This report describes the computer resources that are needed to execute the programs, the installation of the programs, the program designs, some tests of their accuracy, and some suggested improvements.

  10. FORSCOM installation characterization and ranking for water efficiency improvement

    Energy Technology Data Exchange (ETDEWEB)

    Fitzpatrick, Q.K.; McMordie, K.L.; Di Massa, F.V. [and others

    1995-05-01

    On March 11, 1994, President Clinton signed Executive Order 12902-Energy Efficiency and Water Conservation at Federal Facilities. Section 302 of the Executive Order calls for energy and water prioritization surveys of federal facilities to be conducted. The surveys will be used to establish priorities for conducting comprehensive facility audits. In response to the requirements of the Executive Order, the U.S. Army Forces Command (FORSCOM) has tasked Pacific Northwest Laboratory (PNL) to initiate a broad study of the water savings potential at each of its major installations. This report provides an assessment of the water, sewer, energy (for hot water production and pumping), and associated cost savings potential at ten of the major FORSCOM installations. This assessment is meant to be a {open_quotes}first pass{close_quotes} estimate of the water savings potential, to assist FORSCOM in prioritizing installations for detailed water audits and potential water efficient retrofits. In addition, the end uses (toilets, sinks, showerheads, irrigation, etc.) with the greatest water savings potential are identified at each installation. This report is organized in the following manner. Following this Introduction, Section 2 provides important background information pertaining to the water analysis. Section 3 describes the methodology employed in the analysis, and Section 4 summarizes the study results. Section 5 prioritizes the installations based on both water/sewer savings and cost associated with water, sewer, and energy savings. Section 6 provides recommendations on where to start detailed water audits, as well as other recommendations. References are listed in Section 7. The appendices provide specific information on the analysis results and methodology, along with a discussion of special issues.

  11. Arduino Tool: For Interactive Artwork Installations

    CERN Document Server

    Shaikh, Murtaza Hussain

    2012-01-01

    The emergence of the digital media and computational tools has widened the doors for creativity. The cutting edge in the digital arts and role of new technologies can be explored for the possible creativity. This gives an opportunity to involve arts with technologies to make creative works. The interactive artworks are often installed in the places where multiple people can interact with the installation, which allows the art to achieve its purpose by allowing the people to observe and involve with the installation. The level of engagement of the audience depends on the various factors such as aesthetic satisfaction, how the audience constructs meaning, pleasure and enjoyment. The method to evaluate these experiences is challenging as it depends on integration between the artificial life and real life by means of human computer interaction. This research investigates "How Adriano fits for creative and interactive artwork installations?" using an artwork installation in the campus of NTNU (Norwegian University...

  12. Development of acoustic devices for ultra-high energy neutrino detectors

    CERN Document Server

    Karg, T; Graf, K; Hoessl, J; Kappes, A; Katz, U; Lahmann, R; Naumann, C; Salomon, K; Schwemmer, S

    2005-01-01

    Acoustic neutrino detection is a promising approach to instrument the large detector volumes needed for the detection of the small neutrino fluxes expected at ultra-high energies (E > 1 EeV). We report on several studies investigating the feasibility of such an acoustic detector. High-precision lab measurements using laser and proton beams aiming at the verification of the thermo-acoustic model have been performed. Different types of acoustic sensors have been developed and characterized. An autonomous acoustic system, attached to the ANTARES prototype string "Line0", has been deployed and operated successfully at 2400 m depth, allowing for in-situ studies of the acoustic background in the Mediterranean Sea.

  13. Flat acoustic lens by acoustic grating with curled slits

    KAUST Repository

    Peng, Pai

    2014-10-01

    We design a flat sub-wavelength lens that can focus acoustic wave. We analytically study the transmission through an acoustic grating with curled slits, which can serve as a material with tunable impedance and refractive index for acoustic waves. The effective parameters rely on the geometry of the slits and are independent of frequency. A flat acoustic focusing lens by such acoustic grating with gradient effective refractive index is designed. The focusing effect is clearly observed in simulations and well predicted by the theory. We demonstrate that despite the large impedance mismatch between the acoustic lens and the matrix, the intensity at the focal point is still high due to Fabry-Perot resonance.

  14. Acoustic energy harvesting based on a planar acoustic metamaterial

    Science.gov (United States)

    Qi, Shuibao; Oudich, Mourad; Li, Yong; Assouar, Badreddine

    2016-06-01

    We theoretically report on an innovative and practical acoustic energy harvester based on a defected acoustic metamaterial (AMM) with piezoelectric material. The idea is to create suitable resonant defects in an AMM to confine the strain energy originating from an acoustic incidence. This scavenged energy is converted into electrical energy by attaching a structured piezoelectric material into the defect area of the AMM. We show an acoustic energy harvester based on a meta-structure capable of producing electrical power from an acoustic pressure. Numerical simulations are provided to analyze and elucidate the principles and the performances of the proposed system. A maximum output voltage of 1.3 V and a power density of 0.54 μW/cm3 are obtained at a frequency of 2257.5 Hz. The proposed concept should have broad applications on energy harvesting as well as on low-frequency sound isolation, since this system acts as both acoustic insulator and energy harvester.

  15. The Cosmic Microwave Background

    Directory of Open Access Journals (Sweden)

    Jones Aled

    1998-01-01

    Full Text Available We present a brief review of current theory and observations of the cosmic microwave background (CMB. New predictions for cosmological defect theories and an overview of the inflationary theory are discussed. Recent results from various observations of the anisotropies of the microwave background are described and a summary of the proposed experiments is presented. A new analysis technique based on Bayesian statistics that can be used to reconstruct the underlying sky fluctuations is summarised. Current CMB data is used to set some preliminary constraints on the values of fundamental cosmological parameters $Omega$ and $H_circ$ using the maximum likelihood technique. In addition, secondary anisotropies due to the Sunyaev-Zel'dovich effect are described.

  16. Sri Lanka; Background Papers

    OpenAIRE

    International Monetary Fund

    1995-01-01

    This Background Paper on Sri Lanka provides information on the economic developments during 1992–95. Developments in the domestic and external sectors are discussed. The deficiencies of the official consumer price index that resulted in a substantial understatement of inflation performance in 1994 and alternative estimates of underlying inflation are described. The structural rigidities in the labor market that perpetuate high unemployment and limit job growth are also described. The paper ...

  17. Background, phenomenology, and motivation

    International Nuclear Information System (INIS)

    The authors discuss the background to the kinetics of adsorption and desorption after an elementary introduction to the problem of chemisorption in two limiting cases. Other topics discussed include the thermodynamics of adsorption, reaction mechanisms outside surfaces, and a case history of catalytic hydrogenation of carbon monoxide. Figures show the potential energy barrier as a function of an appropriate reaction coordinate, and bonding of carbon monoxide to platinum metal

  18. Australia; Background Material

    OpenAIRE

    International Monetary Fund

    1995-01-01

    This paper describes the developments in the Australian labor market during the 1990s. In 1994, a number of new labor market programs were launched, directed especially at the long-term unemployed, and a further step was taken in the evolutionary reform of the industrial relations system. The paper reviews developments in employment, wages, and productivity in Australia that formed the background to these policy initiatives. It also examines the conduct of fiscal policy at the Commonwealth an...

  19. Some background about satellites

    Science.gov (United States)

    Burns, Joseph A.

    1986-01-01

    Four tables of planetary and satellite data are presented which list satellite discoveries, planetary parameters, satellite orbits, and satellite physical properties respectively. A scheme for classifying the satellites is provided and it is noted that most known moons fall into three general classes: regular satellites, collisional shards, and irregular satellites. Satellite processes are outlined with attention given to origins, dynamical and thermal evolution, surface processes, and composition and cratering. Background material is provided for each family of satellites.

  20. Acoustics Discipline Overview

    Science.gov (United States)

    Envia, Edmane; Thomas, Russell

    2007-01-01

    As part of the Fundamental Aeronautics Program Annual Review, a summary of the progress made in 2007 in acoustics research under the Subsonic Fixed Wing project is given. The presentation describes highlights from in-house and external activities including partnerships and NRA-funded research with industry and academia. Brief progress reports from all acoustics Phase 1 NRAs are also included as are outlines of the planned activities for 2008 and all Phase 2 NRAs. N+1 and N+2 technology paths outlined for Subsonic Fixed Wing noise targets. NRA Round 1 progressing with focus on prediction method advancement. NRA Round 2 initiating work focused on N+2 technology, prediction methods, and validation. Excellent partnerships in progress supporting N+1 technology targets and providing key data sets.

  1. Acoustic Tractor Beam

    Science.gov (United States)

    Démoré, Christine E. M.; Dahl, Patrick M.; Yang, Zhengyi; Glynne-Jones, Peter; Melzer, Andreas; Cochran, Sandy; MacDonald, Michael P.; Spalding, Gabriel C.

    2014-05-01

    Negative radiation forces act opposite to the direction of propagation, or net momentum, of a beam but have previously been challenging to definitively demonstrate. We report an experimental acoustic tractor beam generated by an ultrasonic array operating on macroscopic targets (>1 cm) to demonstrate the negative radiation forces and to map out regimes over which they dominate, which we compare to simulations. The result and the geometrically simple configuration show that the effect is due to nonconservative forces, produced by redirection of a momentum flux from the angled sides of a target and not by conservative forces from a potential energy gradient. Use of a simple acoustic setup provides an easily understood illustration of the negative radiation pressure concept for tractor beams and demonstrates continuous attraction towards the source, against a net momentum flux in the system.

  2. Acoustic absorption by sunspots

    Science.gov (United States)

    Braun, D. C.; Labonte, B. J.; Duvall, T. L., Jr.

    1987-01-01

    The paper presents the initial results of a series of observations designed to probe the nature of sunspots by detecting their influence on high-degree p-mode oscillations in the surrounding photosphere. The analysis decomposes the observed oscillations into radially propagating waves described by Hankel functions in a cylindrical coordinate system centered on the sunspot. From measurements of the differences in power between waves traveling outward and inward, it is demonstrated that sunspots appear to absorb as much as 50 percent of the incoming acoustic waves. It is found that for all three sunspots observed, the amount of absorption increases linearly with horizontal wavenumber. The effect is present in p-mode oscillations with wavelengths both significantly larger and smaller than the diameter of the sunspot umbrae. Actual absorption of acoustic energy of the magnitude observed may produce measurable decreases in the power and lifetimes of high-degree p-mode oscillations during periods of high solar activity.

  3. Acoustic absorption by sunspots

    Energy Technology Data Exchange (ETDEWEB)

    Braun, D.C.; Labonte, B.J.; Duvall, T.L. Jr.

    1987-08-01

    The paper presents the initial results of a series of observations designed to probe the nature of sunspots by detecting their influence on high-degree p-mode oscillations in the surrounding photosphere. The analysis decomposes the observed oscillations into radially propagating waves described by Hankel functions in a cylindrical coordinate system centered on the sunspot. From measurements of the differences in power between waves traveling outward and inward, it is demonstrated that sunspots appear to absorb as much as 50 percent of the incoming acoustic waves. It is found that for all three sunspots observed, the amount of absorption increases linearly with horizontal wavenumber. The effect is present in p-mode oscillations with wavelengths both significantly larger and smaller than the diameter of the sunspot umbrae. Actual absorption of acoustic energy of the magnitude observed may produce measurable decreases in the power and lifetimes of high-degree p-mode oscillations during periods of high solar activity. 10 references.

  4. Variation of solar acoustic emission and its relation to phase of the solar cycle

    Science.gov (United States)

    Chen, Ruizhu; Zhao, Junwei

    2016-05-01

    Solar acoustic emission is closely related to solar convection and photospheric magnetic field. Variation of acoustic emission and its relation to the phase of solar cycles are important to understand dynamics of solar cycles and excitation of acoustic waves. In this work we use 6 years of SDO/HMI Dopplergram data to study acoustic emissions of the whole sun and of the quiet-sun regions, respectively, in multiple acoustic frequency bands. We show the variation of acoustic emission from May 2010 to April 2016, covering half of the solar cycle 24, and analyze its correlation with the solar activity level indexed by daily sunspot number and total magnetic flux. Results show that the correlation between the whole-Sun acoustic emission and the solar activity level is strongly negative for low frequencies between 2.5 and 4.5 mHz, but strongly positive for high frequencies between 4.5 and 6.0 mHz. For high frequencies, the acoustic emission excess in sunspot halos overwhelms the emission deficiency in sunspot umbrae and penumbrae. The correlation between the acoustic emission in quiet regions and the solar activity level is negative for 2.5-4.0 mHz and positive for 4.0-5.5 mHz. This shows that the solar background acoustic power, with active regions excluded, also varies during a solar cycle, implying the excitation frequencies or depths are highly related to the solar magnetic field.

  5. Gait coordination after stroke: Benefits of acoustically paced treadmill walking

    NARCIS (Netherlands)

    Roerdink, Melvyn; Lamoth, Claudine J.C.; Kwakkel, Gert; Van Wieringen, Piet C.W.; Beek, Peter J.

    2007-01-01

    Background and Purpose: Gait coordination often is compromised after stroke. The purpose of this study was to evaluate the efficacy of acoustically paced treadmill walking as a method for improving gait coordination in people after stroke. Participants: Ten people after stroke volunteered for the st

  6. Gait coordination after stroke: benefits of acoustically paced treadmill walking.

    NARCIS (Netherlands)

    Roerdink, M.; Lamoth, C.J.; Kwakkel, G.; Wieringen, P.C. van; Beek, P.J.

    2007-01-01

    BACKGROUND AND PURPOSE: Gait coordination often is compromised after stroke. The purpose of this study was to evaluate the efficacy of acoustically paced treadmill walking as a method for improving gait coordination in people after stroke. PARTICIPANTS: Ten people after stroke volunteered for the st

  7. International proposal for an acoustic classification scheme for dwellings

    DEFF Research Database (Denmark)

    Rasmussen, Birgit

    2014-01-01

    countries, had as one of the main objectives preparation of a proposal for a harmonized acoustic classification scheme. The proposal developed has been approved as an ISO/TC43/SC2 work item, and a working group established. This paper describes the proposal, the background and the perspectives....

  8. The role of classroom acoustics on vocal intensity regulation and speakers’ comfort

    DEFF Research Database (Denmark)

    Pelegrin Garcia, David

    with and without self-reported voice problems reacted identically to variations in noise, whereas they reacted differently to the voice support of the classrooms where they taught, suggesting that teachers with voice problems are more sensitive to the working environment than their healthy colleagues. The acoustic......Teachers are one of the professional groups with the highest risk of suffering from voice disorders. Teachers point out classroom acoustics among the potential hazards affecting their vocal health, together with air dryness, background noise, and other environmental factors. The present project has...... investigated the relationships between the classroom acoustic condition and teachers’ voice, focusing on their vocal intensity, and between the classroom acoustic condition and the sensation of acoustic comfort for a speaker. In the presence of low background noise levels, teachers were found to adjust...

  9. Acoustic Measurements of a Large Civil Transport Main Landing Gear Model

    Science.gov (United States)

    Ravetta, Patricio A.; Khorrami, Mehdi R.; Burdisso, Ricardo A.; Wisda, David M.

    2016-01-01

    Microphone phased array acoustic measurements of a 26 percent-scale, Boeing 777-200 main landing gear model with and without noise reduction fairings installed were obtained in the anechoic configuration of the Virginia Tech Stability Tunnel. Data were acquired at Mach numbers of 0.12, 0.15, and 0.17 with the latter speed used as the nominal test condition. The fully and partially dressed gear with the truck angle set at 13 degrees toe-up landing configuration were the two most extensively tested configurations, serving as the baselines for comparison purposes. Acoustic measurements were also acquired for the same two baseline configurations with the truck angle set at 0 degrees. In addition, a previously tested noise reducing, toboggan-shaped fairing was re-evaluated extensively to address some of the lingering questions regarding the extent of acoustic benefit achievable with this device. The integrated spectra generated from the acoustic source maps reconfirm, in general terms, the previously reported noise reduction performance of the toboggan fairing as installed on an isolated gear. With the recent improvements to the Virginia Tech tunnel acoustic quality and microphone array capabilities, the present measurements provide an additional, higher quality database to the acoustic information available for this gear model.

  10. Acoustic emission source modeling

    Directory of Open Access Journals (Sweden)

    Hora P.

    2010-07-01

    Full Text Available The paper deals with the acoustic emission (AE source modeling by means of FEM system COMSOL Multiphysics. The following types of sources are used: the spatially concentrated force and the double forces (dipole. The pulse excitation is studied in both cases. As a material is used steel. The computed displacements are compared with the exact analytical solution of point sources under consideration.

  11. The acoustics of snoring.

    Science.gov (United States)

    Pevernagie, Dirk; Aarts, Ronald M; De Meyer, Micheline

    2010-04-01

    Snoring is a prevalent disorder affecting 20-40% of the general population. The mechanism of snoring is vibration of anatomical structures in the pharyngeal airway. Flutter of the soft palate accounts for the harsh aspect of the snoring sound. Natural or drug-induced sleep is required for its appearance. Snoring is subject to many influences such as body position, sleep stage, route of breathing and the presence or absence of sleep-disordered breathing. Its presentation may be variable within or between nights. While snoring is generally perceived as a social nuisance, rating of its noisiness is subjective and, therefore, inconsistent. Objective assessment of snoring is important to evaluate the effect of treatment interventions. Moreover, snoring carries information relating to the site and degree of obstruction of the upper airway. If evidence for monolevel snoring at the site of the soft palate is provided, the patient may benefit from palatal surgery. These considerations have inspired researchers to scrutinize the acoustic characteristics of snoring events. Similarly to speech, snoring is produced in the vocal tract. Because of this analogy, existing techniques for speech analysis have been applied to evaluate snoring sounds. It appears that the pitch of the snoring sound is in the low-frequency range (noise-like', and has scattered energy content in the higher spectral sub-bands (>500 Hz). To evaluate acoustic properties of snoring, sleep nasendoscopy is often performed. Recent evidence suggests that the acoustic quality of snoring is markedly different in drug-induced sleep as compared with natural sleep. Most often, palatal surgery alters sound characteristics of snoring, but is no cure for this disorder. It is uncertain whether the perceived improvement after palatal surgery, as judged by the bed partner, is due to an altered sound spectrum. Whether some acoustic aspects of snoring, such as changes in pitch, have predictive value for the presence of

  12. Recent developments of film bulk acoustic resonators

    Science.gov (United States)

    Gao, Junning; Liu, Guorong; Li, Jie; Li, Guoqiang

    2016-06-01

    Film bulk acoustic wave resonator (FBAR) experienced skyrocketing development in the past 15 years, owing to the explosive development of mobile communication. It stands out in acoustic filters mainly because of high quality factor, which enables low insertion loss and sharp roll off. Except for the massive application in wireless communication, FBARs are also promising sensors because of the high sensitivity and readily integration ability to miniaturize circuits. On the ground of summarizing FBAR’s application in wireless communication as filters and in sensors including electronic nose, bio field, and pressure sensing, this paper review the main challenges of each application faced. The number of filters installed in the mobile phone has being grown explosively, which leads to overcrowded bands and put harsh requirements on component size and power consumption control for each unit. Data flow and rate are becoming increasingly demanding as well. This paper discusses three promising technical strategies addressing these issues. Among which coupled resonator filter is given intense attention because it is able to vigorously reduce the filter size by stacking two or more resonators together, and it is a great technique to increase data flow and rate. Temperature compensation methods are discussed considering their vital influence on frequency stability. Finally, materials improvement and novel materials exploration for band width modulation, tunable band acquisition, and quality factor improvement are discussed. The authors appeal attention of the academic society to bring AlN epitaxial thin film into the FBAR fabrication and have proposed a configuration to implement this idea.

  13. Acoustically enhanced heat transport

    Energy Technology Data Exchange (ETDEWEB)

    Ang, Kar M.; Hung, Yew Mun; Tan, Ming K., E-mail: tan.ming.kwang@monash.edu [School of Engineering, Monash University Malaysia, 47500 Bandar Sunway, Selangor (Malaysia); Yeo, Leslie Y. [Micro/Nanophysics Research Laboratory, RMIT University, Melbourne, VIC 3001 (Australia); Friend, James R. [Department of Mechanical and Aerospace Engineering, University of California, San Diego, California 92093 (United States)

    2016-01-15

    We investigate the enhancement of heat transfer in the nucleate boiling regime by inducing high frequency acoustic waves (f ∼ 10{sup 6} Hz) on the heated surface. In the experiments, liquid droplets (deionized water) are dispensed directly onto a heated, vibrating substrate. At lower vibration amplitudes (ξ{sub s} ∼ 10{sup −9} m), the improved heat transfer is mainly due to the detachment of vapor bubbles from the heated surface and the induced thermal mixing. Upon increasing the vibration amplitude (ξ{sub s} ∼ 10{sup −8} m), the heat transfer becomes more substantial due to the rapid bursting of vapor bubbles happening at the liquid-air interface as a consequence of capillary waves travelling in the thin liquid film between the vapor bubble and the air. Further increases then lead to rapid atomization that continues to enhance the heat transfer. An acoustic wave displacement amplitude on the order of 10{sup −8} m with 10{sup 6} Hz order frequencies is observed to produce an improvement of up to 50% reduction in the surface temperature over the case without acoustic excitation.

  14. Acoustics, computers and measurements

    Science.gov (United States)

    Truchard, James J.

    2003-10-01

    The human ear has created a high standard for the requirements of acoustical measurements. The transient nature of most acoustical signals has limited the success of traditional volt meters. Professor Hixson's pioneering work in electroacoustical measurements at ARL and The University of Texas helped set the stage for modern computer-based measurements. The tremendous performance of modern PCs and extensive libraries of signal processing functions in virtual instrumentation application software has revolutionized the way acoustical measurements are made. Today's analog to digital converters have up to 24 bits of resolution with a dynamic range of over 120 dB and a single PC processor can process 112 channels of FFTs at 4 kHz in real time. Wavelet technology further extends the capabilities for analyzing transients. The tools available for measurements in speech, electroacoustics, noise, and vibration represent some of the most advanced measurement tools available. During the last 50 years, Professor Hixson has helped drive this revolution from simple oscilloscope measurements to the modern high performance computer-based measurements.

  15. Infrared Background and Missiles Signature Survey

    Directory of Open Access Journals (Sweden)

    D.V. Renuka

    2013-12-01

    Full Text Available The proliferation of the missile threats in the existing threat scenario for airborne platform is a serious point of consideration for any mission planning. Missile warning system is an electronic warfare support system which gives warning to the pilot when a missile is detected in the scenario. The airborne platform has to be installed with missile warning sensors to give a spherical coverage, so that the sensors can detect the IR intensity variation in the ground scenario. This IR intensity variation has to be further analysed to differentiate the raising missile intensity from the varying background clutter. In order to differentiate the threat from the background clutter, the system should have sufficient background data set for online comparison thereby having less false alarm rate. The efficiency and performance of any missile warning system is validated with respect to its probability of declaration against the false alarm rate. Hence, to realize an efficient functioning of missile warning system, building IR background data base and missile signature database are the primary task. This paper details the methodology to be adapted for the building of tactical missile IR signatures and background data.Defence Science Journal, 2013, 63(6, pp.611-615, DOI:http://dx.doi.org/10.14429/dsj.63.5762

  16. Infrared Background and Missiles Signature Survey

    Directory of Open Access Journals (Sweden)

    D.V. Renuka

    2013-11-01

    Full Text Available The proliferation of the missile threats in the existing threat scenario for airborne platform is a serious point of consideration for any mission planning. Missile warning system is an electronic warfare support system which gives warning to the pilot when a missile is detected in the scenario. The airborne platform has to be installed with missile warning sensors to give a spherical coverage, so that the sensors can detect the IR intensity variation in the ground scenario. This IR intensity variation has to be further analysed to differentiate the raising missile intensity from the varying background clutter. In order to differentiate the threat from the background clutter, the system should have sufficient background data set for online comparison thereby having less false alarm rate. The efficiency and performance of any missile warning system is validated with respect to its probability of declaration against the false alarm rate. Hence, to realize an efficient functioning of missile warning system, building IR background data base and missile signature database are the primary task. This paper details the methodology to be adapted for the building of tactical missile IR signatures and background data.

  17. Radioactive releases from nuclear installations

    International Nuclear Information System (INIS)

    This paper considers the various stages in the pathway from irradiated nuclear fuel to man as separate modules, in each of which mathematical models are derived to represent the transfer of radioactivity. It begins with the generation of the radioactive inventories within fuel, both fission products and the build-up of transuranic elements; the release from fuel is then considered for metal and oxide fuels, following which the effects of plate-out in the reactor circuit are discussed. There is then a detailed treatment of the behaviour of the effluent in the atmosphere including effective height of release, building entrainment, meteorological dispersion, mechanisms for ground deposition and the effects of the duration of release. Having specified the radioactive environment, its interaction with man is described including external exposures from γ-emitting plumes of activity and the estimation of depth doses, as well as the internal organ doses resulting from inhalation or ingestion of radioactivity. Finally, applications of the methods are described in reanalysing the 1957 Windscale accident and in the planning of procedures for reactor accident monitoring as well as in the implications of future reactor designs to assessments of accidental releases. A brief summary of the reactor siting criteria adopted in the U.K. and in the U.S.A. has also been given as a background against which to review the predictive techniques and results from the range of studies of accident considered. (author)

  18. Acoustic-structure coupling scaling laws for model test based steam dryer acoustic fatigue derivations

    International Nuclear Information System (INIS)

    Background: In recent years some reactors have experienced significant steam dryer cracking. In some cases, this cracking has necessitated unplanned outages to implement steam dryer repairs and has also resulted in de-rated operation of the affected units. Initial inspection showed it was likely that steam dryer had been damaged by high cycle fatigue due to flow-induced acoustic resonance in the main steam lines. Because of the complexity and acoustic-structure coupling effect, scale model test is adopted to research the mechanism of acoustic fatigue. Purpose: This paper describes the derivations of scaling laws observed to control the system response for phenomena considered to be significant in the real plants. Methods: Basic governing equations of elasticity and acoustics are written in non-dimensional form, non-dimensional groups are defined and derived. Results: Using the reference values in the real plants, the scaling laws and scaling relationships are derived and recognized to enable conversion of model data into real plant predictions. Conclusions: Successful model testing can be achieved if these significant parameters are preserved in the model scale. (author)

  19. Quasi-normal acoustic oscillations in the transonic Bondi flow

    Science.gov (United States)

    Chaverra, Eliana; Sarbach, Olivier

    2016-01-01

    We analyze the dynamics of nonspherical acoustic perturbations of the transonic Bondi flow, describing the steady radial accretion of a polytropic perfect fluid into a gravity center. The propagation of such perturbations can be described by a wave equation on the curved effective background geometry determined by the acoustic metric introduced by Unruh in the context of experimental black hole evaporation. We show that for the transonic Bondi flow, Unruh's acoustic metric describes an analogue black hole and that the acoustic perturbations undergo quasi-normal oscillations. The associated quasi-normal frequencies are computed and they are proven to scale like the surface gravity of the acoustic black hole. This provides an explanation for results given in an earlier work, where it was shown that the acoustic perturbations of a relativistic fluid accreted by a nonrotating black hole possess quasi-normal modes, and where it was found empirically that the associated frequencies scaled like the surface gravity of the analogue black hole in the limit where the radius of the sonic horizon is much larger than the Schwarzschild radius.

  20. Acoustical considerations for an automotive hands-free mobile terminal

    Science.gov (United States)

    Ruhala, Richard J.; Iyengar, Vasu

    2002-05-01

    The harsh acoustical environment of an automotive interior yields significant difficulty in controlling acoustic echo and noise during ``hands-free'' wireless phone calls. In addition to having multiple closely coupled reflection paths, the user (talker) is often positioned between the loudspeaker and microphone path. This can cause frequent changes in the acoustic path which necessitates fast and accurate adaptation of the acoustic echo canceller and/or non-linear controller. Further, the frequency response between the talker and the microphone is altered due to cabin resonances and modes; it is also strongly affected by their positions. Additional acoustical considerations for automotive hands-free implementations are the high levels and non-stationary statistics of background noise, high amplification, and possible resultant distortion of the received audio signal, and non-linear network echo. These impairments yield significant challenges in controlling the acoustic echo and noise in full-duplex, partial-duplex, and even half-duplex systems. In this work, impulse response, frequency response, and SNR measurements are presented and analyzed to demonstrate the critical differences between a traditional desktop speakerphone and an automotive hands-free mobile terminal.

  1. Muon-induced backgrounds in the CUORICINO experiment

    Energy Technology Data Exchange (ETDEWEB)

    Andreotti, E.; Arnaboldi, C.; Avignone III, F. T.; Balata, M.; Bandac, I.; Barucci, M.; Beeman, J. W.; Bellini, F.; Bloxham, T.; Brofferio, C.; Bryant, A.; Bucci, C.; Canonica, L.; Capelli, S.; Carbone, L.; Carrettoni, M.; Clemenza, M.; Cremonesi, O.; Creswick, R. J.; Domizio, S. Di; Dolinski, M. J.; Ejzak, L.; Faccini, R.; Farach, H. A.; Ferri, E.; Ferroni, F.; Fiorini, E.; Foggetta, L.; Giachero, A.; Gironi, L.; Giuliani, A.; Gorla, P.; Guardincerri, E.; Gutierrez, T. D.; Haller, E. E.; Kadel, R.; Kazkaz, K.; Kraft, S.; Kogler, L.; Kolomensky, Yu. G.; Maiano, C.; Maruyama, R. H.; Martinez, C.; Martinez, M.; Mizouni, L.; Morganti, S.; Nisi, S.; Nones, C.; Norman, E. B.; Nucciotti, A.; Orio, F.; Pallavicini, M.; Palmieri, V.; Pattavina, L.; Pavan, M.; Pedretti, M.; Pessina, G.; Pirro, S.; Previtali, E.; Risegari, L.; Rosenfeld, C.; Rusconi, C.; Salvioni, C.; Sangiorgio, S.; Schaeffer, D.; Scielzo, N. D.; Sisti, M.; Smith, A. R.; Tomei, C.; Ventura, G.; Vignati, M.

    2010-04-15

    To better understand the contribution of cosmic ray muons to the CUORICINO background, ten plastic scintillator detectors were installed at the CUORICINO siteand operated during the final 3 months of the experiment. From these measurements, an upper limit of 0.0021 counts/(keV.kg.yr) (95percent c.l.) was obtained on the cosmicray induced background in the neutrinoless double beta decay region of interest. The measurements were also compared to Geant4 simulations.

  2. Background reduction of a spherical gaseous detector

    Energy Technology Data Exchange (ETDEWEB)

    Fard, Ali Dastgheibi [Laboratoire Souterrain de Modane, France ali.dastgheibi-fard@lsm.in2p3.fr (France); Loaiza, Pia; Piquemal, Fabrice [Laboratoire Souterrain de Modane (France); Giomataris, Ioannis; Gray, David; Gros, Michel; Magnier, Patrick; Navick, Xavier-François [CEA Saclay - IRFU/SEDI - 91191 Gif sur Yvette (France); Savvidis, Ilias [Aristotle University of Thessaloniki (Greece)

    2015-08-17

    The Spherical gaseous detector (or Spherical Proportional Counter, SPC) is a novel type of detector. It consists of a large spherical volume filled with gas, using a single detection readout channel. The detector allows 100 % detection efficiency. SEDINE is a low background version of SPC installed at the Laboratoire Souterrain de Modane (LSM) underground laboratory (4800 m.w.e) looking for rare events at very low energy threshold, below 100 eV. This work presents the details on the chemical cleaning to reduce internal {sup 210}Pb surface contamination on the copper vessel and the external radon reduction achieved via circulation of pure air inside anti-radon tent. It will be also show the radon measurement of pure gases (Ar, N, Ne, etc) which are used in the underground laboratory for the low background experiments.

  3. A novel method for coiled tubing installation

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, Peter J. [2H Offshore, Houston, TX (United States); Tibbetts, David [Aquactic Engineering and Construction Ltd., Aberdeen (United Kingdom)

    2009-12-19

    Installation of flexible pipe for offshore developments is costly due to the physical cost of the flexible pipe, expensive day rates and the availability of suitable installation vessels. Considering the scarcity of flexible pipe in today's increasingly demanding and busy market, operators are seeking a cost effective solution for installing piping in a range of water depths using vessels which are readily on hand. This paper describes a novel approach to installing reeled coiled tubing, from 1 inch to 5 inch diameter, from the back of a small vessel in water depths from 40 m up to around 1000 m. The uniqueness of the system is the fact that the equipment design is modular and compact. This means that when disassembled, it fits into standard 40 ft shipping containers, and the size allows it to be installed on even relatively small vessels of opportunity, such as anchor handling or installation vessels, from smaller, and cheaper quay side locations. Such an approach is the ideal solution to the problem faced by operators, in that it allows the installation of cheaper, readily available coiled tubing, from cost-effective vessels, which do not need to transit to a pick up the system. (author)

  4. Fundamentals of Shallow Water Acoustics

    CERN Document Server

    Katsnelson, Boris; Lynch, James

    2012-01-01

    Shallow water acoustics (SWA), the study of how low and medium frequency sound propagates and scatters on the continental shelves of the world's oceans, has both technical interest and a large number of practical applications. Technically, shallow water poses an interesting medium for the study of acoustic scattering, inverse theory, and propagation physics in a complicated oceanic waveguide. Practically, shallow water acoustics has interest for geophysical exploration, marine mammal studies, and naval applications. Additionally, one notes the very interdisciplinary nature of shallow water acoustics, including acoustical physics, physical oceanography, marine geology, and marine biology. In this specialized volume, the authors, all of whom have extensive at-sea experience in U.S. and Russian research efforts, have tried to summarize the main experimental, theoretical, and computational results in shallow water acoustics, with an emphasis on providing physical insight into the topics presented.

  5. Latest Trends in Acoustic Sensing

    Directory of Open Access Journals (Sweden)

    Cinzia Caliendo

    2014-03-01

    Full Text Available Acoustics-based methods offer a powerful tool for sensing applications. Acoustic sensors can be applied in many fields ranging from materials characterization, structural health monitoring, acoustic imaging, defect characterization, etc., to name just a few. A proper selection of the acoustic wave frequency over a wide spectrum that extends from infrasound (<20 Hz up to ultrasound (in the GHz–band, together with a number of different propagating modes, including bulk longitudinal and shear waves, surface waves, plate modes, etc., allow acoustic tools to be successfully applied to the characterization of gaseous, solid and liquid environments. The purpose of this special issue is to provide an overview of the research trends in acoustic wave sensing through some cases that are representative of specific applications in different sensing fields.

  6. High-Frequency Seafloor Acoustics

    CERN Document Server

    Jackson, Darrell R

    2007-01-01

    High-Frequency Seafloor Acoustics is the first book in a new series sponsored by the Office of Naval Research on the latest research in underwater acoustics. This exciting new title provides ready access to experimental data, theory, and models relevant to high-frequency seafloor acoustics and will be of interest to sonar engineers and researchers working in underwater acoustics. The physical characteristics of the seafloor affecting acoustic propagation and scattering are covered, including physical and geoacoustic properties and surface roughness. Current theories for acoustic propagation in sediments are presented along with corresponding models for reflection, scattering, and seafloor penetration. The main text is backed up by an extensive bibliography and technical appendices.

  7. Acoustic characterization of historic cloisters in Portugal

    OpenAIRE

    Carvalho, A; Anabela Carvalho

    2004-01-01

    This paper presents the results of field measurements in 20 cloisters of old monasteries in Portugal (length: 15 to 55 m and height: 3.7 to 8.5 m) regarding their acoustic behavior to some objective parameters: RT, RASTI and background sound level. The individual results show, for instance, that the mean measured values in each cloister for RASTI were from 0.33 to 0.64 (with a global mean value of 0.50 for all rooms) and for the RT (1 kHz) were from 1.0 to 4.5 s (with a global mean of 2.5 s f...

  8. Instability of Bucket Foundations during Installation

    DEFF Research Database (Denmark)

    Madsen, Søren; Andersen, Lars Vabbersgaard; Ibsen, Lars Bo

    The bucket foundation is an upcoming technology for offshore wind turbines. The bucket foundation is a large cylindrical monopod foundation constructed as a thin steel shell structure. A bucket foundation does not require heavy installation equipment since it is installed by suction forces. The...... combination of a thin shell structure and suction forces leads to the fact that instability, in form of buckling, becomes a crucial issue during installation. The hydrostatic buckling pressure of the bucket foundation is addressed using three-dimensional, non-linear finite element analysis. The results of the...

  9. Installing and Testing a Server Operating System

    OpenAIRE

    Jäntschi, Lorentz

    2003-01-01

    The paper is based on the experience of the author with the FreeBSD server operating system administration on three servers in use under academicdirect.ro domain.The paper describes a set of installation, preparation, and administration aspects of a FreeBSD server.First issue of the paper is the installation procedure of FreeBSD operating system on i386 computer architecture. Discussed problems are boot disks preparation and using, hard disk partitioning and operating system installation usin...

  10. Acoustical coupling of lizard eardrums

    DEFF Research Database (Denmark)

    Christensen-Dalsgaard, Jakob; Manley, Geoffrey A

    2008-01-01

    Lizard ears are clear examples of two-input pressure-difference receivers, with up to 40-dB differences in eardrum vibration amplitude in response to ipsi- and contralateral stimulus directions. The directionality is created by acoustical coupling of the eardrums and interaction of the direct...... is caused by the acoustic interaction of the two eardrums. The results can be largely explained by a simple acoustical model based on an electrical analog circuit....

  11. Room acoustic auralization with Ambisonics

    OpenAIRE

    Polack, Jean-Dominique; Leão Figueiredo, Fábio

    2012-01-01

    International audience During the year of 2009, the room acoustics group of the LAM (Équipe Lutheries, Acoustique, Musique de l’Institut Jean Le Rond d’Alembert - Université Pierre et Marie Curie, Paris) performed a series of acoustical measurements in music halls in Paris. The halls were chosen in regarding their importance to the historic, architectural or acoustic domains. The measured ensemble of fourteen rooms includes quite different architectural designs. The measurements were carri...

  12. Simulating acoustic waves in spotted stars

    Science.gov (United States)

    Papini, Emanuele; Birch, Aaron C.; Gizon, Laurent; Hanasoge, Shravan M.

    2015-05-01

    Acoustic modes of oscillation are affected by stellar activity, however it is unclear how starspots contribute to these changes. Here we investigate the nonmagnetic effects of starspots on global modes with angular degree ℓ ≤ 2 in highly active stars, and characterize the spot seismic signature on synthetic light curves. We perform 3D time-domain simulations of linear acoustic waves to study their interaction with a model starspot. We model the spot as a 3D change in the sound speed stratification with respect to a convectively stable stellar background, built from solar Model S. We perform a parametric study by considering different depths and perturbation amplitudes. Exact numerical simulations allow the investigation of the wavefield-spot interaction beyond first order perturbation theory. The interaction of the axisymmetric modes with the starspot is strongly nonlinear. As mode frequency increases, the frequency shifts for radial modes exceed the value predicted by linear theory, while the shifts for the ℓ = 2,m = 0 modes are smaller than predicted by linear theory, with avoided-crossing-like patterns forming between the m = 0 and m = 1 mode frequencies. The nonlinear behavior increases with increasing spot amplitude and/or decreasing depth. Linear theory still reproduces the correct shifts for nonaxisymmetric modes. In the nonlinear regime the mode eigenfunctions are not pure spherical harmonics, but rather a mixture of different spherical harmonics. This mode mixing, together with the frequency changes, may lead to misidentification of the modes in the observed acoustic power spectra.

  13. Background and introduction

    DEFF Research Database (Denmark)

    Jensen, Per Anker; van der Voordt, Theo; Coenen, Christian

    2012-01-01

    Purpose: To explain the purpose and background of this book and introduce the three basic perspectives behind the research presented as well as the structure and editing process of the book. Methodology: The editors shared and discussed individual contributions to this chapter, based on their own...... in scope between FM and CREM is that CREM has its focus on real estate as physical and economical assets utilized by an organisation, while FM has a wider service focus. The difference in scope between FM and CREM on one side and B2B marketing on the other is that FM and CREM are related to organisations...

  14. Family Background and Entrepreneurship

    DEFF Research Database (Denmark)

    Lindquist, Matthew J.; Sol, Joeri; Van Praag, Mirjam;

    Vast amounts of money are currently being spent on policies aimed at promoting entrepreneurship. The success of such policies, however, rests in part on the assumption that individuals are not ‘born entrepreneurs’. In this paper, we assess the importance of family background and neighborhood...... effects as determinants of entrepreneurship. We start by estimating sibling correlations in entrepreneurship. We find that between 20 and 50 percent of the variance in different entrepreneurial outcomes is explained by factors that siblings share. The average is 28 percent. Allowing for differential...... entrepreneurship does play a large role, as do shared genes....

  15. Malaysia; Background Paper

    OpenAIRE

    International Monetary Fund

    1996-01-01

    This Background Paper on Malaysia examines developments and trends in the labor market since the mid-1980s. The paper describes the changes in the employment structure and the labor force. It reviews wages and productivity trends and their effects on unit labor cost. The paper highlights that Malaysia’s rapid growth, sustained since 1987, has had a major impact on the labor market. The paper outlines the major policy measures to address the labor constraints. It also analyzes Malaysia’s r...

  16. Structural considerations for solar installers : an approach for small, simplified solar installations or retrofits.

    Energy Technology Data Exchange (ETDEWEB)

    Richards, Elizabeth H.; Schindel, Kay (City of Madison, WI); Bosiljevac, Tom; Dwyer, Stephen F.; Lindau, William (Lindau Companies, Inc., Hudson, WI); Harper, Alan (City of Madison, WI)

    2011-12-01

    Structural Considerations for Solar Installers provides a comprehensive outline of structural considerations associated with simplified solar installations and recommends a set of best practices installers can follow when assessing such considerations. Information in the manual comes from engineering and solar experts as well as case studies. The objectives of the manual are to ensure safety and structural durability for rooftop solar installations and to potentially accelerate the permitting process by identifying and remedying structural issues prior to installation. The purpose of this document is to provide tools and guidelines for installers to help ensure that residential photovoltaic (PV) power systems are properly specified and installed with respect to the continuing structural integrity of the building.

  17. Background Noise Acceptance and Personality Factors Involved in Library Environment Choices by College Students

    Science.gov (United States)

    Gordon-Hickey, Susan; Lemley, Trey

    2012-01-01

    For decades, academic libraries made efforts to provide study environments differing in acoustic environment. The present study aimed to provide an evidence basis for this practice by comparing background noise acceptance and personality factors of two groups of college-aged students self identified as preferring quiet or background noise when…

  18. Combined Environment Acoustic Chamber (CEAC)

    Data.gov (United States)

    Federal Laboratory Consortium — Purpose: The CEAC imposes combined acoustic, thermal and mechanical loads on aerospace structures. The CEAC is employed to measure structural response and determine...

  19. The Backgrounds Data Center

    Science.gov (United States)

    Snyder, W. A.; Gursky, H.; Heckathorn, H. M.; Lucke, R. L.; Berg, S. L.; Dombrowski, E. G.; Kessel, R. A.

    1993-01-01

    The Strategic Defense Initiative Organization has created data centers for midcourse, plumes, and backgrounds phenomenologies. The Backgrounds Data Center (BDC) has been designated as the prime archive for data collected by SDIO programs. The BDC maintains a Summary Catalog that contains 'metadata,' that is, information about data, such as when the data were obtained, what the spectral range of the data is, and what region of the Earth or sky was observed. Queries to this catalog result in a listing of all data sets (from all experiments in the Summary Catalog) that satisfy the specified criteria. Thus, the user can identify different experiments that made similar observations and order them from the BDC for analysis. On-site users can use the Science Analysis Facility (SAFE for this purpose. For some programs, the BDC maintains a Program Catalog, which can classify data in as many ways as desired (rather than just by position, time, and spectral range as in the Summary Catalog). For example, data sets could be tagged with such diverse parameters as solar illumination angle, signal level, or the value of a particular spectral ratio, as long as these quantities can be read from the digital record or calculated from it by the ingest program. All unclassified catalogs and unclassified data will be remotely accessible.

  20. Prototype solar-heating system - installation manual

    Science.gov (United States)

    1978-01-01

    Manual for prototype solar-heating system gives detailed installation procedures for each of seven subsystems. Procedures for operation and maintenance are also included. It discusses architectural considerations, building construction considerations, and checkout-test procedures.

  1. Notes on LED Installations in Street Illumination

    Directory of Open Access Journals (Sweden)

    Elisabeta Spunei

    2014-09-01

    Full Text Available The paper presents a study made on choosing LED street lighting installations, such that the quality requirements for exterior artificial lighting are fulfilled. We analyze two types of LED street lighting installations from a technical point of view, together with lighting level and brightness values obtained during the measurements. Following on the field measurements, the lighting quality parameters are calculated, and, for the lighting installation with the best performance, optimal mounting suggestions are made. The optimal quality parameters are calculated by simulations using the Dialux software. The same software and the same light sources we also compute an optimal street lighting by determining the size of the installation that provides the best lighting parameter values.

  2. Structural Code Considerations for Solar Rooftop Installations.

    Energy Technology Data Exchange (ETDEWEB)

    Dwyer, Stephen F.; Dwyer, Brian P.; Sanchez, Alfred

    2014-12-01

    Residential rooftop solar panel installations are limited in part by the high cost of structural related code requirements for field installation. Permitting solar installations is difficult because there is a belief among residential permitting authorities that typical residential rooftops may be structurally inadequate to support the additional load associated with a photovoltaic (PV) solar installation. Typical engineering methods utilized to calculate stresses on a roof structure involve simplifying assumptions that render a complex non-linear structure to a basic determinate beam. This method of analysis neglects the composite action of the entire roof structure, yielding a conservative analysis based on a rafter or top chord of a truss. Consequently, the analysis can result in an overly conservative structural analysis. A literature review was conducted to gain a better understanding of the conservative nature of the regulations and codes governing residential construction and the associated structural system calculations.

  3. Subsea flexible flowline installation issues and solutions

    Institute of Scientific and Technical Information of China (English)

    Kevin Huang

    2013-01-01

    Flexible flowlines and risers have been increasingly used for deepwater and ultra-deepwater field applications,partially because of its low submerged weight and better dynamic characteristics comparing to rigid pipelines.The offshore installation of flowline may have advantages as well.However,it has special needs for the installation aids,and it is challenging to install tie-in structures due to its low bending stiffness.This paper is to present some of the challenges during a recent flexible installation project with a total of more than 100 km flexible flowlines,and 24 in-line sleds/pipeline end termination(PLET) in water depth up to 1 300 m.

  4. Culture safety in the nuclear installation

    International Nuclear Information System (INIS)

    Culture safety is aimed to empower all the personnel to contribute and responsible to the installation safety where they work in. Culture safety is important as there were so many accidents happened due to the little attention given to the safety, take as examples of what happened in Three Mille Island installation (1979) and Chernobyl (1986). These remind us that human factor gives a significant contribution to the failure of operational system which influences the safety. Therefore, as one of institutions which has nuclear installation. National Nuclear Energy Agency must apply the culture safety to guarantee the safety operation of nuclear installation to protect the personnel, community and environment from the hazard of radioactive radiation. Culture safety has two main components. The first component under the management responsibility is a framework needed in an organisation. The second component is the personnel attitude in al/ levels to respond and optimize those framework. (author)

  5. RF accelerating unit installed in the PSB

    CERN Multimedia

    1972-01-01

    RF accelerating unit installed in the PSB ring between two bending magnets. Cool air from a heat exchanger is injected into the four cavities from the central feeder and the hot air recirculated via the lateral ducts.

  6. Towards a Framework for Projection Installations

    DEFF Research Database (Denmark)

    Halskov, Kim; Falck, Hans William

    2013-01-01

    a conceptual framework that addresses three aspects of a projection installation: the contentassociated with the object, the digital content, and the relation between the two. We conclude the paper with a set of strategies commonly used in projection installations: Enhancing or emphasizing physical aspects......Projection installations are part of Spatially Augmented Reality, where the projection medium is used to enrich a fixed, bounded physical space with digital content. Projection technology enables us to turn many kinds of physical objects into displays. In this paper we develop and present......; Transforming materiality; Adding virtual objects; 3D effects; Complex content on simple objects or simple content on complex; Strong versus loose connections between the physical object and the digital content. This paper is based on four cases, two of which concern cultural heritage installations, the others...

  7. Software Management Environment (SME) installation guide

    Science.gov (United States)

    Kistler, David; Jeletic, Kellyann

    1992-01-01

    This document contains installation information for the Software Management Environment (SME), developed for the Systems Development Branch (Code 552) of the Flight Dynamics Division of Goddard Space Flight Center (GSFC). The SME provides an integrated set of management tools that can be used by software development managers in their day-to-day management and planning activities. This document provides a list of hardware and software requirements as well as detailed installation instructions and trouble-shooting information.

  8. Virtual Instrumentality : Exploring Embodiment in Artistic Installations

    OpenAIRE

    Christou, Maria; Tache, Olivier; Luciani, Annie; Barthélemy, Daniel

    2011-01-01

    Paper session : Virtual Reality, Virtual Materiality, Virtual Instrumentality - Proceedings of the conference available online only - http://isea2011.sabanciuniv.edu/paper/virtual-instrumentality-exploring-embodiment-artistic-installations International audience In this paper we study the question of interaction with digital technologies by exploring the cognitive mechanisms of embodiment in the context of multisensory artistic installations. In order to test our hypothesis we observed ...

  9. Acoustic transparency and slow sound using detuned acoustic resonators

    DEFF Research Database (Denmark)

    Santillan, Arturo Orozco; Bozhevolnyi, Sergey I.

    2011-01-01

    We demonstrate that the phenomenon of acoustic transparency and slowsound propagation can be realized with detuned acoustic resonators (DAR), mimicking thereby the effect of electromagnetically induced transparency (EIT) in atomic physics. Sound propagation in a pipe with a series of side...

  10. Installation of the LHC transfer lines begins

    CERN Multimedia

    Patrice Loïez

    2003-01-01

    The first of 700 magnets has been installed in one of the two transfer tunnels built to transfer the SPS beam into the LHC. The start of this first installation phase of the LHC transfer lines provides the opportunity to launch a new and highly original modular system for transporting and installing all kinds of magnets in very narrow tunnels. The system is based on very compact bogies, up to four of which can be coupled together to form a convoy. The wheels are fitted with individual motors enabling them to swivel through an angle of 90° and the convoy to move laterally. The first installation phase will continue until mid-April. In addition to the magnets, a beam dump facility also has to be installed. The second installation phase will take place later this year and should be completed in 2004, when the TI 8 transfer line is due to be tested. The second transfer line, in tunnel TI 2, should be ready in April 2007, once the LHC magnets have been transported through the downstream section of this tunnel.Pho...

  11. Installation of the LHC transfer lines begins

    CERN Multimedia

    Patrice Loïez

    2003-01-01

    The first of 700 magnets has been installed in one of the two transfer tunnels built to transfer the SPS beam into the LHC. The start of this first installation phase of the LHC transfer lines provides the opportunity to launch a new and highly original modular system for transporting and installing all kinds of magnets in very narrow tunnels. The system is based on very compact bogies, up to four of which can be coupled together to form a convoy. The wheels are fitted with individual motors enabling them to swivel through an angle of 90° and the convoy to move laterally. The first installation phase will continue until mid-April. In addition to the magnets, a beam dump facility also has to be installed. The second installation phase will take place later this year and should be completed in 2004, when the TI 8 transfer line is due to be tested. The second transfer line, in tunnel TI 2, should be ready in April 2007, once the LHC magnets have been transported through the downstream section of this tunnel. Th...

  12. Installation of the LHC transfer lines begins

    CERN Multimedia

    Patrice Loïez

    2003-01-01

    The first of 700 magnets has been installed in one of the two transfer tunnels built to transfer the SPS beam into the LHC. The start of this first installation phase of the LHC transfer lines provides the opportunity to launch a new and highly original modular system for transporting and installing all kinds of magnets in very narrow tunnels. The system is based on very compact bogies, up to four of which can be coupled together to form a convoy. The wheels are fitted with individual motors enabling them to swivel through an angle of 90° and the convoy to move laterally. The first installation phase will continue until mid-April. In addition to the magnets, a beam dump facility also has to be installed. The second installation phase will take place later this year and should be completed in 2004, when the TI 8 transfer line is due to be tested. The second transfer line, in tunnel TI 2, should be ready in April 2007, once the LHC magnets have been transported through the downstream section of this tunnel. We...

  13. Ultraviolet Background Radiation

    Science.gov (United States)

    Henry, R. C.; Murthy, J.

    1993-12-01

    The UVX experiment was carried on the Space Shuttle Columbia between 1986 January 12 and 19 (STS-61C). Several ultraviolet spectrometers were used to obtain measurements of the diffuse ultraviolet background at 8 locations in the sky. We have reanalysed the UVX measurements of the surface brightness of the diffuse ultraviolet background above b = 40 using the dust-scattering model of Onaka & Kodaira (1991), which explicitly takes into account the variation of the source function with galactic longitude. The range of allowed values of interstellar grain albedoJa, and scattering asymmetry parameter g, is considerably expanded over those of a previous analysis. The new chi square probability contours come close to, but do not include, the values of a and g found for the interstellar grains by Witt et al. (1992) using the Ultraviolet Imaging Telescope (UIT) on the Astro mission. If we hypothesize in additon to the dust-scattered light an extragalactic component, of 300 1 100 photons cm-2 s-1 sr-1 A-1, attenuated by a cosecant b law, the new reduction of the UVX data gives complete consistency with the Witt et al. determination of the optical parameters of the grains in the ultraviolet. This work was supported by United States Air Force Contract F19628-93-K-0004, and by National Aeronautics and Space Administration grant NASA NAG5-619. We are grateful for the encouragement of Dr. Stephan Price, and we thank Dr. L. Danly for information. Onaka, T., & Kodaira, K. 1991, ApJ, 379, 532 Witt, A. N., Petersohn, J. K., Bohlin, R. C., O'Connell, R. W., Roberts, M. S., Smith, A. M., & Stecher, T. P. 1992, ApJ, 395, L5

  14. Cosmic microwave background theory.

    Science.gov (United States)

    Bond, J R

    1998-01-01

    A long-standing goal of theorists has been to constrain cosmological parameters that define the structure formation theory from cosmic microwave background (CMB) anisotropy experiments and large-scale structure (LSS) observations. The status and future promise of this enterprise is described. Current band-powers in -space are consistent with a DeltaT flat in frequency and broadly follow inflation-based expectations. That the levels are approximately (10(-5))2 provides strong support for the gravitational instability theory, while the Far Infrared Absolute Spectrophotometer (FIRAS) constraints on energy injection rule out cosmic explosions as a dominant source of LSS. Band-powers at 100 suggest that the universe could not have re-ionized too early. To get the LSS of Cosmic Background Explorer (COBE)-normalized fluctuations right provides encouraging support that the initial fluctuation spectrum was not far off the scale invariant form that inflation models prefer: e.g., for tilted Lambda cold dark matter sequences of fixed 13-Gyr age (with the Hubble constant H0 marginalized), ns = 1.17 +/- 0.3 for Differential Microwave Radiometer (DMR) only; 1.15 +/- 0.08 for DMR plus the SK95 experiment; 1.00 +/- 0.04 for DMR plus all smaller angle experiments; 1.00 +/- 0.05 when LSS constraints are included as well. The CMB alone currently gives weak constraints on Lambda and moderate constraints on Omegatot, but theoretical forecasts of future long duration balloon and satellite experiments are shown which predict percent-level accuracy among a large fraction of the 10+ parameters characterizing the cosmic structure formation theory, at least if it is an inflation variant.

  15. Electroacoustical simulation of listening room acoustics for project ARCHIMEDES

    DEFF Research Database (Denmark)

    Bech, Søren

    1989-01-01

    influence of listening room acoustics on the timbre of reproduced sound. For simulation of the acoustics of a standard listening room, an electroacoustic setup has been built in an anechoic chamber. The setup is based on a computer model of the listening room, and it consists of a number of loudspeakers...... listening room. This paper is a presentation of the system, with special emphasis on the psychoacoustical background of the design. This will include a discussion of choice of experimental procedure, test stimuli, and test subjects as well as purpose built loudspeakers and the DSP system....

  16. Acoustic Mechanical Feedthroughs

    Science.gov (United States)

    Sherrit, Stewart; Walkemeyer, Phillip; Bao, Xiaoqi; Bar-Cohen, Yoseph; Badescu, Mircea

    2013-01-01

    Electromagnetic motors can have problems when operating in extreme environments. In addition, if one needs to do mechanical work outside a structure, electrical feedthroughs are required to transport the electric power to drive the motor. In this paper, we present designs for driving rotary and linear motors by pumping stress waves across a structure or barrier. We accomplish this by designing a piezoelectric actuator on one side of the structure and a resonance structure that is matched to the piezoelectric resonance of the actuator on the other side. Typically, piezoelectric motors can be designed with high torques and lower speeds without the need for gears. One can also use other actuation materials such as electrostrictive, or magnetostrictive materials in a benign environment and transmit the power in acoustic form as a stress wave and actuate mechanisms that are external to the benign environment. This technology removes the need to perforate a structure and allows work to be done directly on the other side of a structure without the use of electrical feedthroughs, which can weaken the structure, pipe, or vessel. Acoustic energy is pumped as a stress wave at a set frequency or range of frequencies to produce rotary or linear motion in a structure. This method of transferring useful mechanical work across solid barriers by pumping acoustic energy through a resonant structure features the ability to transfer work (rotary or linear motion) across pressure or thermal barriers, or in a sterile environment, without generating contaminants. Reflectors in the wall of barriers can be designed to enhance the efficiency of the energy/power transmission. The method features the ability to produce a bi-directional driving mechanism using higher-mode resonances. There are a variety of applications where the presence of a motor is complicated by thermal or chemical environments that would be hostile to the motor components and reduce life and, in some instances, not be

  17. Taming Acoustic Cavitation

    CERN Document Server

    Rivas, David Fernandez; Enriquez, Oscar R; Versluis, Michel; Prosperetti, Andrea; Gardeniers, Han; Lohse, Detlef

    2012-01-01

    In this fluid dynamics video we show acoustic cavitation occurring from pits etched on a silicon surface. By immersing the surface in a liquid, gas pockets are entrapped in the pits which upon ultrasonic insonation, are observed to shed cavitation bubbles. Modulating the driving pressure it is possible to induce different behaviours based on the force balance that determines the interaction among bubbles and the silicon surface. This system can be used for several applications like sonochemical water treatment, cleaning of surfaces with deposited materials such as biofilms.

  18. Lecture Notes On Acoustics

    International Nuclear Information System (INIS)

    This book mentions string vibration and wave, one-dimension wave and wave equation, characteristic impedance, governing equation of string, and wave energy from string, wave equation of wave and basic physical quantity like one-dimension wave equation, sound unit, sound intensity and energy, sound movement in a surface of discontinuity with transmission loss of sound by partition, and Snell's law, radiation, scatter and diffraction and sound in closed space with Sabine's theory, sound characteristic of closed space and duct acoustics.

  19. Dynamic acoustic tractor beams

    Energy Technology Data Exchange (ETDEWEB)

    Mitri, F. G., E-mail: F.G.Mitri@ieee.org [Chevron, Area 52 Technology – ETC, Santa Fe, New Mexico 87508 (United States)

    2015-03-07

    Pulling a sphere and vibrating it around an equilibrium position by amplitude-modulation in the near-field of a single finite circular piston transducer is theoretically demonstrated. Conditions are found where a fluid hexane sphere (with arbitrary radius) chosen as an example, centered on the axis of progressive propagating waves and submerged in non-viscous water, experiences an attractive (steady) force pulling it towards the transducer, as well as an oscillatory force forcing it to vibrate back-and-forth. Numerical predictions for the dynamic force illustrate the theory and suggest an innovative method in designing dynamic acoustical tractor beams.

  20. Dynamic acoustic tractor beams

    Science.gov (United States)

    Mitri, F. G.

    2015-03-01

    Pulling a sphere and vibrating it around an equilibrium position by amplitude-modulation in the near-field of a single finite circular piston transducer is theoretically demonstrated. Conditions are found where a fluid hexane sphere (with arbitrary radius) chosen as an example, centered on the axis of progressive propagating waves and submerged in non-viscous water, experiences an attractive (steady) force pulling it towards the transducer, as well as an oscillatory force forcing it to vibrate back-and-forth. Numerical predictions for the dynamic force illustrate the theory and suggest an innovative method in designing dynamic acoustical tractor beams.

  1. Understanding Piezo Based Sensors for Acoustic Neutrino Detection

    International Nuclear Information System (INIS)

    The ANTARES collaboration is currently installing a neutrino telescope off the French Mediterranean coast to measure diffuse fluxes and point sources of high energy cosmic neutrinos. The complete detector will consist of 900 photomultipliers on 12 detector lines, using 0.01km3 of sea water as target material. As part of the ANTARES deep-sea research infrastructure, the Erlangen group is planning to modify several ANTARES storeys by fitting them with acoustic receivers to study the feasibility of acoustic neutrino detection in the deep sea. In this paper, studies of the electromechanical properties of piezoelectric sensors are presented, based on an equivalent circuit diagram for the coupled mechanical and electrical oscillations of a piezoelectric element. A method for obtaining the system parameters as well as derivations of sensor properties like pressure sensitivity and intrinsic noise are treated and results compared to measurements. Finally, a possible application of these results for simulating system response and optimising reconstruction algorithms is discussed

  2. Installation and Operation of the SNO Neutral Current Detector Array

    Energy Technology Data Exchange (ETDEWEB)

    Heise, J. [Physics Division, Los Alamos National Laboratory, Los Alamos, NM, 87545 (United States); McGee, S. [Center for Experimental Nuclear Physics and Astrophysics, and Department of Physics, University of Washington, Seattle, WA, 98195 (United States); Rielage, K. [Center for Experimental Nuclear Physics and Astrophysics, and Department of Physics, University of Washington, Seattle, WA, 98195 (United States)

    2005-06-15

    An array of low background detectors designed to capture neutrons liberated by interactions with solar neutrinos was recently installed in the heavy water region of the SNO experiment. The neutral current detector (NCD) array consists of 36 proportional counters filled with {sup 3}He-CF{sub 4} gas and 4 proportional counters filled with {sup 4}He-CF{sub 4}. Special hardware conforming to the high radiopurity requirements in SNO was used to assemble and deploy these counters. Neutron events detected by the NCD array are distinguished from various types of backgrounds on an event-by-event basis using the NCD data acquisition system (NCDDAQ), which employs a mixture of commercial and custom-built electronics equipment. The NCDDAQ is controlled by a custom-built Object-oriented Realtime Control and Acquisition (ORCA) software program, and is fully integrated into the SNO PMT data acquisition system to provide shared trigger information and a combined data stream.

  3. An investigation of the acoustic characteristics of a compression ignition engine operating with biodiesel blends

    International Nuclear Information System (INIS)

    In this paper, an experimental investigation has been carried out on the acoustic characteristics of a compression ignition (CI) engine running with biodiesel blends under steady state operating conditions. The experiment was conducted on a four-cylinder, four-stroke, direct injection and turbocharged diesel engine which runs with biodiesel (B50 and B100) and pure diesel. The signals of acoustic, vibration and in-cylinder pressure were measured during the experiment. To correlate the combustion process and the acoustic characteristics, both phenomena have been investigated. The acoustic analysis resulted in the sound level being increased with increasing of engine loads and speeds as well as the sound characteristics being closely correlated to the combustion process. However, acoustic signals are highly sensitive to the ambient conditions and intrusive background noise. Therefore, the spectral subtraction was employed to minimize the effects of background noise in order to enhance the signal to noise ratio. In addition, the acoustic characteristics of CI engine running with different fuels (biodiesel blends and diesel) was analysed for comparison. The results show that the sound energy level of acoustic signals is slightly higher when the engine fuelled by biodiesel and its blends than that of fuelled by normal diesel. Hence, the acoustic characteristics of the CI engine will have useful information for engine condition monitoring and fuel content estimation.

  4. AMADEUS - The Acoustic Neutrino Detection Test System of the ANTARES Deep-Sea Neutrino Telescope

    CERN Document Server

    Aguilar, J A; Albert, A; Anghinolfi, M; Anton, G; Anvar, S; Ardid, M; Jesus, A C Assis; Astraatmadja, T; Aubert, J-J; Auer, R; Barbarito, E; Baret, B; Basa, S; Bazzotti, M; Bertin, V; Biagi, S; Bigongiari, C; Bou-Cabo, M; Bouwhuis, M C; Brown, A; Brunner, J; Busto, J; Camarena, F; Capone, A; Cârloganu, C; Carminati, G; Carr, J; Cassano, B; Castorina, E; Cavasinni, V; Cecchini, S; Ceres, A; Charvis, Ph; Chiarusi, T; Sen, N Chon; Circella, M; Coniglione, R; Costantini, H; Cottini, N; Coyle, P; Curtil, C; De Bonis, G; Decowski, M P; Dekeyser, I; Deschamps, A; Distefano, C; Donzaud, C; Dornic, D; Drouhin, D; Eberl, T; Emanuele, U; Ernenwein, J-P; Escoffier, S; Fehr, F; Fiorello, C; Flaminio, V; Fritsch, U; Fuda, J-L; Gay, P; Giacomelli, G; Gómez-González, J P; Graf, K; Guillard, G; Halladjian, G; Hallewell, G; van Haren, H; Heijboer, A J; Heine, E; Hello, Y; Hernández-Rey, J J; Herold, B; Hößl, J; de Jong, M; Kalantar-Nayestanaki, N; Kalekin, O; Kappes, A; Katz, U; Keller, P; Kooijman, P; Kopper, C; Kouchner, A; Kretschmer, W; Lahmann, R; Lamare, P; Lambard, G; Larosa, G; Laschinsky, H; Le Provost, H; Lefèvre, D; Lelaizant, G; Lim, G; Presti, D Lo; Loehner, H; Loucatos, S; Louis, F; Lucarelli, F; Mangano, S; Marcelin, M; Margiotta, A; Martinez-Mora, J A; Mazure, A; Mongelli, M; Montaruli, T; Morganti, M; Moscoso, L; Motz, H; Naumann, C; Neff, M; Ostasch, R; Palioselitis, D; Pavalas, G E; Payre, P; Petrovic, J; Picot-Clemente, N; Picq, C; Popa, V; Pradier, T; Presani, E; Racca, C; Radu, A; Reed, C; Riccobene, G; Richardt, C; Rujoiu, M; Ruppi, M; Russo, G V; Salesa, F; Sapienza, P; Schöck, F; Schuller, J-P; Shanidze, R; Simeone, F; Spurio, M; Steijger, J J M; Stolarczyk, Th; Taiuti, M; Tamburini, C; Tasca, L; Toscano, S; Vallage, B; Van Elewyck, V; Vannoni, G; Vecchi, M; Vernin, P; Wijnker, G; de Wolf, E; Yepes, H; Zaborov, D; Zornoza, J D; Zúñiga, J; 10.1016/j.nima.2010.09.053

    2010-01-01

    The AMADEUS (ANTARES Modules for the Acoustic Detection Under the Sea) system which is described in this article aims at the investigation of techniques for acoustic detection of neutrinos in the deep sea. It is integrated into the ANTARES neutrino telescope in the Mediterranean Sea. Its acoustic sensors, installed at water depths between 2050 and 2300 m, employ piezo-electric elements for the broad-band recording of signals with frequencies ranging up to 125 kHz. The typical sensitivity of the sensors is around -145 dB re 1V/muPa (including preamplifier). Completed in May 2008, AMADEUS consists of six "acoustic clusters", each comprising six acoustic sensors that are arranged at distances of roughly 1 m from each other. Two vertical mechanical structures (so-called lines) of the ANTARES detector host three acoustic clusters each. Spacings between the clusters range from 14.5 to 340 m. Each cluster contains custom-designed electronics boards to amplify and digitise the acoustic signals from the sensors. An on...

  5. Acoustic Similarity and Dichotic Listening.

    Science.gov (United States)

    Benson, Peter

    1978-01-01

    An experiment tests conjectures that right ear advantage (REA) has an auditory origin in competition or interference between acoustically similar stimuli and that feature-sharing effect (FSE) has its origin in assignment of features of phonetically similar stimuli. No effect on the REA for acoustic similarity, and a clear effect of acoustic…

  6. Acoustic Center or Time Origin?

    DEFF Research Database (Denmark)

    Staffeldt, Henrik

    1999-01-01

    The paper discusses the acoustic center in relation to measurements of loudspeaker polar data. Also, it presents the related concept time origin and discusses the deviation that appears between positions of the acoustic center found by wavefront based and time based measuring methods....

  7. Digital Controller For Acoustic Levitation

    Science.gov (United States)

    Tarver, D. Kent

    1989-01-01

    Acoustic driver digitally controls sound fields along three axes. Allows computerized acoustic levitation and manipulation of small objects for such purposes as containerless processing and nuclear-fusion power experiments. Also used for controlling motion of vibration-testing tables in three dimensions.

  8. Propagation of Ion Acoustic Perturbations

    DEFF Research Database (Denmark)

    Pécseli, Hans

    1975-01-01

    Equations describing the propagation of ion acoustic perturbations are considered, using the assumption that the electrons are Boltzman distributed and isothermal at all times. Quasi-neutrality is also considered.......Equations describing the propagation of ion acoustic perturbations are considered, using the assumption that the electrons are Boltzman distributed and isothermal at all times. Quasi-neutrality is also considered....

  9. Low background infrared (LBIR) facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Low background infrared (LBIR) facility was originally designed to calibrate user supplied blackbody sources and to characterize low-background IR detectors and...

  10. Acoustic emission in ITER CS model coil and CS insert coil

    International Nuclear Information System (INIS)

    Acoustic emission (AE) signals induced from the Central Solenoid Model Coil (CSMC) and the Central Solenoid Insert Coil (CSIC) of the International Thermonuclear Experimental Reactor (ITER) are described. Two kinds of AE data acquisition methods for the AE signals are adopted during series of energizing, i.e., one is the whole waveform recording, and the other is the AE envelope recording. It can be estimated that the AE signals are mainly induced by motion of a superconductor because the AE signals synchronize with the voltage spikes, especially in the virgin current region. The multi channel measurement provided us with information about the spatial distribution of disturbances by the AE sensors at each installed point in CSMC. The observation of AE with high-time resolution shows that the disturbances in CSMC decrease with the iteration number of excitation, judging from instantaneous AE levels, AE energies, and AE event count. Meanwhile, under the background field of 13 T by CSMC, charging and discharging tests of the CSIC at the rate of 5 kA/s from 0 kA to 40 kA were repeated 10,003 times. We monitored the disturbances in CSIC and in CSMC during this cyclic test by using envelope signals of an AE sensor installed near the bottom of the innermost layer of CSMC. The detected AE signals were large, in the range of 1,000 to 2,000 times and 3,000 to 4,000 times. And after that, the AE signals were very small, until 10,003 times. From 3,000 through 4,000 times, we monitored strange AE behaviours that can be attributed to the loosening of bolts. (author)

  11. Hanford Site background: Part 1, Soil background for nonradioactive analytes

    International Nuclear Information System (INIS)

    Volume two contains the following appendices: Description of soil sampling sites; sampling narrative; raw data soil background; background data analysis; sitewide background soil sampling plan; and use of soil background data for the detection of contamination at waste management unit on the Hanford Site

  12. The Swiss nuclear installations annual report 1992

    International Nuclear Information System (INIS)

    This report concerns the safety of the Swiss nuclear installations in the period of 1992. Surveillance of these installations with regard to nuclear safety, including radiation protection, is among the tasks of the Swiss Federal Nuclear Safety Inspectorate (HSK). In Switzerland five nuclear power plants are operational: Beznau I and II, Muehleberg, Goesgen and Leibstadt. Research reactors of thermal capacities below 10 MWth are operational at the Paul Scherrer Institute (PSI), at the Swiss Federal Institute of Technology Lausanne and at the University of Basle. Further subject to HSK's supervision are all activities at PSI involving nuclear fuel or ionizing radiation, the shut down experimental reactor of Lucens, the exploration in Switzerland of final disposal facilities for radwaste and the interim radwaste storage facilities. The present report first deals with the nuclear power plants and covers, in individual sections, the aspects of installation safety, radiation protection as well as personnel and organization, and the resulting overall impression from the point of view of HSK (chapters 1-4). In chapter 5, the corresponding information is given for the research installations. Chapter 6 on radwaste disposal is dedicated to the waste treatment, waste from reprocessing, interim storage and exploration by the NAGRA. In chapter 7, the status of emergency planning in the nuclear power plants' vicinity is reported. Certificates issued for the transport of radioactive materials are dealt with in chapter 8. Finally chapter 9 goes into some general questions relating to the safety of nuclear installations, and in particular covers important events in nuclear installations abroad. In all, the operation of the Swiss nuclear installations in the period of 1992 is rated safe by HSK. (author) 7 figs., 13 tabs

  13. Genetical background of intelligence.

    Science.gov (United States)

    Junkiert-Czarnecka, Anna; Haus, Olga

    2016-01-01

    Intelligence as an ability to reason, think abstractly and adapt effectively to the environment is a subject of research in the field of psychology, neurobiology, and in the last twenty years genetics as well. Genetical testing of twins carried out from XX century indicated heritebility of intelligence, therefore confirmed an influence of genetic factor on cognitive processes. Studies on genetic background of intelligence focus on dopaminergic (DRD2, DRD4, COMT, SLC6A3, DAT1, CCKAR) and adrenergic system (ADRB2, CHRM2) genes as well as, neutrofins (BDNF) and oxidative stress genes (LTF, PRNP). Positive effect of investigated gene polymorphism was indicated by variation c.957C>T DRD2 gene (if in polymorphic site is thymine), polymorphism c.472G>A COMT gene (presence of adenine) and also gene ADRB2 c.46A->G (guanine), CHRM2 (thymine in place c.1890A>T) and BDNF (guanine in place c.472G>A) Obtained results indicate that intelligence is a feature dependent not only on genetic but also an environmental factor. PMID:27333929

  14. Biological aerosol background characterization

    Science.gov (United States)

    Blatny, Janet; Fountain, Augustus W., III

    2011-05-01

    To provide useful information during military operations, or as part of other security situations, a biological aerosol detector has to respond within seconds or minutes to an attack by virulent biological agents, and with low false alarms. Within this time frame, measuring virulence of a known microorganism is extremely difficult, especially if the microorganism is of unknown antigenic or nucleic acid properties. Measuring "live" characteristics of an organism directly is not generally an option, yet only viable organisms are potentially infectious. Fluorescence based instruments have been designed to optically determine if aerosol particles have viability characteristics. Still, such commercially available biological aerosol detection equipment needs to be improved for their use in military and civil applications. Air has an endogenous population of microorganisms that may interfere with alarm software technologies. To design robust algorithms, a comprehensive knowledge of the airborne biological background content is essential. For this reason, there is a need to study ambient live bacterial populations in as many locations as possible. Doing so will permit collection of data to define diverse biological characteristics that in turn can be used to fine tune alarm algorithms. To avoid false alarms, improving software technologies for biological detectors is a crucial feature requiring considerations of various parameters that can be applied to suppress alarm triggers. This NATO Task Group will aim for developing reference methods for monitoring biological aerosol characteristics to improve alarm algorithms for biological detection. Additionally, they will focus on developing reference standard methodology for monitoring biological aerosol characteristics to reduce false alarm rates.

  15. MEMS Based Acoustic Array

    Science.gov (United States)

    Sheplak, Mark (Inventor); Nishida, Toshikaza (Inventor); Humphreys, William M. (Inventor); Arnold, David P. (Inventor)

    2006-01-01

    Embodiments of the present invention described and shown in the specification aid drawings include a combination responsive to an acoustic wave that can be utilized as a dynamic pressure sensor. In one embodiment of the present invention, the combination has a substrate having a first surface and an opposite second surface, a microphone positioned on the first surface of the substrate and having an input and a first output and a second output, wherein the input receives a biased voltage, and the microphone generates an output signal responsive to the acoustic wave between the first output and the second output. The combination further has an amplifier positioned on the first surface of the substrate and having a first input and a second input and an output, wherein the first input of the amplifier is electrically coupled to the first output of the microphone and the second input of the amplifier is electrically coupled to the second output of the microphone for receiving the output sinual from the microphone. The amplifier is spaced from the microphone with a separation smaller than 0.5 mm.

  16. Acoustics and Hearing

    CERN Document Server

    Damaske, Peter

    2008-01-01

    When one listens to music at home, one would like to have an acoustic impression close to that of being in the concert hall. Until recently this meant elaborate multi-channelled sound systems with 5 or more speakers. But head-related stereophony achieves the surround-sound effect in living rooms with only two loudspeakers. By virtue of their slight directivity as well as an electronic filter the limitations previously common to two-speaker systems can be overcome and this holds for any arbitrary two-channel recording. The book also investigates the question of how a wide and diffuse sound image can arise in concert halls and shows that the quality of concert halls decisively depends on diffuse sound images arising in the onset of reverberation. For this purpose a strong onset of reverberation is modified in an anechoic chamber by electroacoustic means. Acoustics and Hearing proposes ideas concerning signal processing in the auditory system that explain the measured results and the resultant sound effects plea...

  17. Acoustic data transmission method

    Energy Technology Data Exchange (ETDEWEB)

    Duckworth, A.

    1991-09-17

    This patent describes a method for transmitting time line data through a drillstring having drill pipe sections connected end-to-end by joints from a first location below the surface of the earth to a second location at or near the surface of the earth, the length and cross-sectional area of the drill pipe sections being different from the length and cross-sectional area of the joints. It comprises generating acoustic data signals having a single frequency content in at least one passband of the drillstring; transmitting the data signals through the drillstring from either the first location to the second location or from the second location to the first location during a time period prior to the onset of reflective interference caused by the data signals reflecting from along the length of the drillstring, the time period being equal to or less than the time for the data signals to travel three lengths of the drillstring; stopping the transmission of data signals at the onset of the reflective interference and allowing the acoustic signals to substantially attenuate; and detecting the data signals at the respective first or second location.

  18. Muon-induced backgrounds in the CUORICINO experiment

    Energy Technology Data Exchange (ETDEWEB)

    Andreotti, E; Arnaboldi, C; Avignone, F T; Balata, M; Bandac, I; Barucci, M; Beeman, J W; Bellini, F; Bloxham, T; Brofferio, C; Bryant, A; Bucci, C; Canonica, L; Capelli, S; Carbone, L; Carrettoni, M; Clemenza, M; Cremonesi, O; Creswick, R J; Domizio, S D; Dolinski, M J; Ejzak, L; Faccini, R; Farach, H A; Ferri, E; Ferroni, F; Firoini, E; Foggetta, L; Giachero, A; Gironi, L; Giuliani, A; Gorla, P; Guardincerri, E; Gutierrez, T D; Haller, E E; Kadel, R; Kazkaz, K; Kraft, S; Kogler, L; Kolomensky, Y G; Maiano, C; Maruyama, R H; Martinez, C; Martinez, M; Mizouni, L; Morganti, S; Nisi, S; Nones, C; Norman, E B; Nucciotti, A; Orio, F; Pallavicini, M; Palmieri, V; Pattavina, L; Pavan, M; Pedretti, M; Pessina, G; Pirro, S; Previtali, E; Risegari, L; Rosenfeld, C; Rusconi, C; Salvioni, C; Sangiorgio, S; Schaeffer, D; Scielzo, N D; Sisti, M; Smith, A R; Tomei, C; Ventura, G; Vignati, M

    2009-11-16

    To better understand the contribution of cosmic ray muons to the CUORICINO background, ten plastic scintillator detectors were installed at the CUORICINO site and operated during 3 months of the CUORICINO experiment. From these measurements, an upper limit of 0.0021 counts/keV {center_dot} kg {center_dot} yr (95% C.L.) was obtained on the cosmic ray induced background in the neutrinoless double beta decay region of interest. The measurements were compared to Geant4 simulations, which are similar to those that will be used to estimate the backgrounds in CUORE.

  19. Planning and installing micro-hydro systems a guide for designers, installers and engineers

    CERN Document Server

    Elliott, Chris

    2014-01-01

    An essential addition to the Earthscan Planning & Installing series, Planning and Installing Micro-Hydro Systems provides vital diagrams, pictures and tables detailing the planning and installing of a micro-hydro system, including information on the maintenance and economics once an installation is running. The book covers subjects such as measuring head and flow, ecological impacts, scheme layouts, practical advice, calculations and turbine choice. Archimedes screws are also covered in detail, as well as the main conventional choices relevant to small sites.Micro-hydro refers to hydropower sy

  20. Cloaking an acoustic sensor with single-negative materials

    International Nuclear Information System (INIS)

    In this review, a brief introduction is given to the development of acoustic superlens cloaks that allow the cloaked object to receive signals while its presence is not sensed by the surrounding, which can be regarded as “cloaking an acoustic sensor”. Remarkably, the designed cloak consists of single-negative materials with parameters independent of the background medium or the sensor system, which is proven to be a magnifying superlens. This has facilitated significantly the design and fabrication of acoustic cloaks that generally require double-negative materials with customized parameters. Such innovative design has then been simplified further as a multi-layered structure comprising of two alternately arranged complementary media with homogeneous isotropic single-negative materials. Based on this, a scattering analyses method is developed for the numerical simulation of such multi-layered cloak structures, which may serve as an efficient approach for the investigation on such devices

  1. Cloaking an acoustic sensor with single-negative materials

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Chen [Key Laboratory of Modern Acoustics, MOE, Department of Physics, Collaborative Innovation Center for Advanced Microstructures, Nanjing University, Nanjing 210093 (China); Zhu, Xue-Feng [Department of Physics, Huazhong University of Science and Technology, Wuhan 430074 (China); Xu, Tao [Key Laboratory of Modern Acoustics, MOE, Department of Physics, Collaborative Innovation Center for Advanced Microstructures, Nanjing University, Nanjing 210093 (China); Zou, Xin-Ye, E-mail: xyzou@nju.edu.cn [Key Laboratory of Modern Acoustics, MOE, Department of Physics, Collaborative Innovation Center for Advanced Microstructures, Nanjing University, Nanjing 210093 (China); Liang, Bin; Cheng, Jian-Chun [Key Laboratory of Modern Acoustics, MOE, Department of Physics, Collaborative Innovation Center for Advanced Microstructures, Nanjing University, Nanjing 210093 (China)

    2015-07-15

    In this review, a brief introduction is given to the development of acoustic superlens cloaks that allow the cloaked object to receive signals while its presence is not sensed by the surrounding, which can be regarded as “cloaking an acoustic sensor”. Remarkably, the designed cloak consists of single-negative materials with parameters independent of the background medium or the sensor system, which is proven to be a magnifying superlens. This has facilitated significantly the design and fabrication of acoustic cloaks that generally require double-negative materials with customized parameters. Such innovative design has then been simplified further as a multi-layered structure comprising of two alternately arranged complementary media with homogeneous isotropic single-negative materials. Based on this, a scattering analyses method is developed for the numerical simulation of such multi-layered cloak structures, which may serve as an efficient approach for the investigation on such devices.

  2. Installing and Testing a Server Operating System

    Directory of Open Access Journals (Sweden)

    Lorentz JÄNTSCHI

    2003-08-01

    Full Text Available The paper is based on the experience of the author with the FreeBSD server operating system administration on three servers in use under academicdirect.ro domain.The paper describes a set of installation, preparation, and administration aspects of a FreeBSD server.First issue of the paper is the installation procedure of FreeBSD operating system on i386 computer architecture. Discussed problems are boot disks preparation and using, hard disk partitioning and operating system installation using a existent network topology and a internet connection.Second issue is the optimization procedure of operating system, server services installation, and configuration. Discussed problems are kernel and services configuration, system and services optimization.The third issue is about client-server applications. Using operating system utilities calls we present an original application, which allows displaying the system information in a friendly web interface. An original program designed for molecular structure analysis was adapted for systems performance comparisons and it serves for a discussion of Pentium, Pentium II and Pentium III processors computation speed.The last issue of the paper discusses the installation and configuration aspects of dial-in service on a UNIX-based operating system. The discussion includes serial ports, ppp and pppd services configuration, ppp and tun devices using.

  3. Installation of the LHC transfer lines begins

    CERN Multimedia

    Patrice Loïez

    2003-01-01

    The first of 700 magnets has been installed in one of the two transfer tunnels built to transfer the SPS beam into the LHC. The start of this first installation phase of the LHC transfer lines provides the opportunity to launch a new and highly original modular system for transporting and installing all kinds of magnets in very narrow tunnels. The system is based on very compact bogies, up to four of which can be coupled together to form a convoy. The wheels are fitted with individual motors enabling them to swivel through an angle of 90° and the convoy to move laterally. In this way the magnet is delivered directly to its installation point, but beneath the beamline. It is then raised into its final position in the beamline using air cushions, which form an integrated part of the transport system.Photos 01, 02: Pictured with the newly installed magnet and transport system in the transfer line tunnel are LHC project leader Lyn Evans (second left, white helmet); Volker Mertens, responsible for the LHC injecti...

  4. Installation of the LHC transfer lines begins

    CERN Multimedia

    Patrice Loïez

    2003-01-01

    The first of 700 magnets has been installed in one of the two transfer tunnels built to transfer the SPS beam into the LHC. The start of this first installation phase of the LHC transfer lines provides the opportunity to launch a new and highly original modular system for transporting and installing all kinds of magnets in very narrow tunnels. The system is based on very compact bogies, up to four of which can be coupled together to form a convoy. The wheels are fitted with individual motors enabling them to swivel through an angle of 90° and the convoy to move laterally. In this way the magnet is delivered directly to its installation point, but beneath the beamline. It is then raised into its final position in the beamline using air cushions, which form an integrated part of the transport system.Photo 01: Pictured with the newly installed magnet and transport system in the transfer line tunnel are (left to right) Volker Mertens, responsible for the LHC injection and transfer lines; personnel involved in tr...

  5. Staggered-grid finite-difference acoustic modeling with the Time-Domain Atmospheric Acoustic Propagation Suite (TDAAPS).

    Energy Technology Data Exchange (ETDEWEB)

    Aldridge, David Franklin; Collier, Sandra L. (U.S. Army Research Laboratory); Marlin, David H. (U.S. Army Research Laboratory); Ostashev, Vladimir E. (NOAA/Environmental Technology Laboratory); Symons, Neill Phillip; Wilson, D. Keith (U.S. Army Cold Regions Research Engineering Lab.)

    2005-05-01

    This document is intended to serve as a users guide for the time-domain atmospheric acoustic propagation suite (TDAAPS) program developed as part of the Department of Defense High-Performance Modernization Office (HPCMP) Common High-Performance Computing Scalable Software Initiative (CHSSI). TDAAPS performs staggered-grid finite-difference modeling of the acoustic velocity-pressure system with the incorporation of spatially inhomogeneous winds. Wherever practical the control structure of the codes are written in C++ using an object oriented design. Sections of code where a large number of calculations are required are written in C or F77 in order to enable better compiler optimization of these sections. The TDAAPS program conforms to a UNIX style calling interface. Most of the actions of the codes are controlled by adding flags to the invoking command line. This document presents a large number of examples and provides new users with the necessary background to perform acoustic modeling with TDAAPS.

  6. VERA 3.5 Installation Guide

    Energy Technology Data Exchange (ETDEWEB)

    Bartlett, Roscoe A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Baird, Mark L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Berrill, Mark A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Kulesza, Joel A. [Univ. of Michigan, Ann Arbor, MI (United States); Mervin, Brenden T. [Electric Power Research Inst. (EPRI), Charlotte, NC (United States)

    2016-08-16

    This guide describes the structure and setup of the standard VERA development environment (VERA Dev Env) and standard VERA Third Party Libraries (TPLs) that need to be in place before installing many of the VERA simulation components. It describes everything from the initial setup on a new machine to the final build, testing, and installation of VERA components. The goal of this document is to describe how to create the directories and contents outlined in Standard VERA Dev Env Directory Structure and then obtain the remaining VERA source and build, test, and install any of the necessary VERA components on a given system. This document describes the process both for a development version of VERA and for a released tarball of the VERA sources.

  7. Piping installation for reactor heavy water system

    International Nuclear Information System (INIS)

    Characteristics and main installation steps for the piping of the reactor heavy water loop system were introduced in this paper. According to the system design, equipment accommodation and spot management, main issues with effect on the quality and schedule of pipeline installation were analyzed. Accordingly, some solutions were put forward, which included: work allocation should be made clear in documents; installation preparative such as design checkup and technology communication should be prepared completely; requirements of system cleaning, test items in every experiment, inspection in work and equipment maintenance should be considered in the system design; perfect documents distribution system and stock plan should be built; technology requirements and quality assurance should be claimed in contracts; quality should be controlled by way of external evidence, inspection in manufactory, exterior quality assurance examination, and test during consignment; series of management procedure should be established in detail. (authors)

  8. Experimental installation with pressurized fluidized bed boiler

    Energy Technology Data Exchange (ETDEWEB)

    Dobrzanski, W.; Szwarc, W.; Jurek, K.; Prokop, A. (Politechnika Warszawska (Poland). Instytut Techniki Cieplnej)

    1990-01-01

    Describes a test installation with a 3 MW pressurized fluidized bed boiler. The installation was commissioned at the Institute of Heat Engineering at the Technical University in Warsaw. Predesign assumptions and the lay-out of the installation are given. A schematic diagram of the pressurized (0.6 MPa) fluidized bed boiler with an inner diameter of 1.4 m and a total height of 5.45 m is shown. The fuel feeding system consists of a coal and adsorbent container, two feeders and an air jet pump for pneumatic transport. A water type boiler is integrated into the pressure vessel. Flue gas cyclones are also integrated into a separate pressure vessel. The computerized control system and instrumentation are described. Temperatures, pressures, pressure differences, rotational speeds and the chemical composition of gases are monitored.

  9. Listed installations for environmental protection in hospitals

    International Nuclear Information System (INIS)

    This work deals with the implications of different French rules and regulations concerning the environmental protection in hospitals. A special place is given to listed installations for environmental protection, because of their importance. A summary of important regulatory texts is presented concerning these installations, and also an inventory of installations or activities concerned, and the definition of the necessary procedures. Some ideas are also given about the much needed creation of an 'environmental network' inside hospitals, in order to cope with these concerns. Then, we briefly deal with more recent developments concerning the environmental protection, which will, no doubt, extend to hospitals, such as the French water law, air law, and procedures for the management of medical waste. Finally, the stakes of environmental decisions in hospitals and the chemist's place in these decisions are debated. (authors)

  10. An installation for steam conversion of gases

    Energy Technology Data Exchange (ETDEWEB)

    Tabata, K.; Matsumoto, I.

    1983-01-28

    An installation is proposed for steam conversion of a hydrocarbon gas in order to produce an inorganic gas which chiefly consists of H2 and CO in which the line for feeding the hydrocarbon gas has a steam generator which has a microcapillary structure made of sponge metal, inorganic heat resistant fibers of glass, Si02, Al203 or carbon, inorganic heat resistant fibers twisted into a fiber or a cord of multipore ceramic material; the installation is equipped with a heater which regulates the water temperature, in which the steam generator is submerged. The installation is designed for converting natural gas, C3H8, other hydrocarbon gases and vapors of liquid hydrocarbons (Uv) into H2 and CO. The design and disposition of the steam generator simplify the design of the device, eliminating the pump for feeding the steam and the device for premixing of the steam and hydrocarbon gas.

  11. Acoustic analysis in Mudejar-Gothic churches: Experimental results

    Science.gov (United States)

    Galindo, Miguel; Zamarreño, Teófilo; Girón, Sara

    2005-05-01

    This paper describes the preliminary results of research work in acoustics, conducted in a set of 12 Mudejar-Gothic churches in the city of Seville in the south of Spain. Despite common architectural style, the churches feature individual characteristics and have volumes ranging from 3947 to 10 708 m3. Acoustic parameters were measured in unoccupied churches according to the ISO-3382 standard. An extensive experimental study was carried out using impulse response analysis through a maximum length sequence measurement system in each church. It covered aspects such as reverberation (reverberation times, early decay times), distribution of sound levels (sound strength); early to late sound energy parameters derived from the impulse responses (center time, clarity for speech, clarity, definition, lateral energy fraction), and speech intelligibility (rapid speech transmission index), which all take both spectral and spatial distribution into account. Background noise was also measured to obtain the NR indices. The study describes the acoustic field inside each temple and establishes a discussion for each one of the acoustic descriptors mentioned by using the theoretical models available and the principles of architectural acoustics. Analysis of the quality of the spaces for music and speech is carried out according to the most widespread criteria for auditoria. .

  12. Acoustic analysis in Mudejar-Gothic churches: experimental results.

    Science.gov (United States)

    Galindo, Miguel; Zamarreño, Teófilo; Girón, Sara

    2005-05-01

    This paper describes the preliminary results of research work in acoustics, conducted in a set of 12 Mudejar-Gothic churches in the city of Seville in the south of Spain. Despite common architectural style, the churches feature individual characteristics and have volumes ranging from 3947 to 10 708 m3. Acoustic parameters were measured in unoccupied churches according to the ISO-3382 standard. An extensive experimental study was carried out using impulse response analysis through a maximum length sequence measurement system in each church. It covered aspects such as reverberation (reverberation times, early decay times), distribution of sound levels (sound strength); early to late sound energy parameters derived from the impulse responses (center time, clarity for speech, clarity, definition, lateral energy fraction), and speech intelligibility (rapid speech transmission index), which all take both spectral and spatial distribution into account. Background noise was also measured to obtain the NR indices. The study describes the acoustic field inside each temple and establishes a discussion for each one of the acoustic descriptors mentioned by using the theoretical models available and the principles of architectural acoustics. Analysis of the quality of the spaces for music and speech is carried out according to the most widespread criteria for auditoria. PMID:15957758

  13. Carcinomatous meningitis appearing as acoustic neuromas. Two cases

    Energy Technology Data Exchange (ETDEWEB)

    Astner, S.T.; Nieder, C.; Grosu, A.L. [Technical Univ. of Munich (Germany). Dept. of Radiation Oncology; Stock, K. [Technical Univ. of Munich (Germany). Dept. of Internal Medicine; Gaa, J. [Technical Univ. of Munich (Germany). Dept. of Radiology

    2007-05-15

    Background: For acoustic neuromas, stereotactic radiotherapy (radiosurgery or stereotactic fractionated radiotherapy) has been established as an important alternative to microsurgery. In most cases initial symptoms are slow progression of unilateral hearing loss, tinnitus or vertigo or acute hearing loss with vertigo. MRI scan shows a contrast-enhancing tumor within the inner auditory channel. If the patient undergoes primary radiotherapy, diagnosis is usually not verified histologically. Therefore, careful evaluation of the medical history is mandatory despite a typical appearance on the MRI scan. If medical history does not match with acoustic neuroma, further diagnostics are necessary to rule out infectious disease or carcinomatous meningitis. Case Report: Two patients with hearing loss, vertigo and the diagnosis of acoustic neuromas by MRI scan were referred for radiotherapy. In both cases the symptoms progressed very rapidly, not typical of acoustic neuromas, and in both patients repeated liquor puncture finally revealed carcinomatous meningitis. One patient died during therapy; in the second patient intrathecal chemotherapy and additional radiotherapy of the skull base led to partial remission continuing for several months. Conclusion: Before primary radiotherapy of small intrameatal lesions diagnosis must be reassessed carefully. This is especially true for bilateral lesions suspicious for acoustic neuromas and rapid progression and persistence of clinical symptoms where carcinomatous meningitis has to be taken into account. (orig.)

  14. Cosmic Microwave Background Data Analysis

    Science.gov (United States)

    Paykari, Paniez; Starck, Jean-Luc Starck

    2012-03-01

    About 400,000 years after the Big Bang the temperature of the Universe fell to about a few thousand degrees. As a result, the previously free electrons and protons combined and the Universe became neutral. This released a radiation which we now observe as the cosmic microwave background (CMB). The tiny fluctuations* in the temperature and polarization of the CMB carry a wealth of cosmological information. These so-called temperature anisotropies were predicted as the imprints of the initial density perturbations which gave rise to the present large-scale structures such as galaxies and clusters of galaxies. This relation between the present-day Universe and its initial conditions has made the CMB radiation one of the most preferred tools to understand the history of the Universe. The CMB radiation was discovered by radio astronomers Arno Penzias and Robert Wilson in 1965 [72] and earned them the 1978 Nobel Prize. This discovery was in support of the Big Bang theory and ruled out the only other available theory at that time - the steady-state theory. The crucial observations of the CMB radiation were made by the Far-Infrared Absolute Spectrophotometer (FIRAS) instrument on the Cosmic Background Explorer (COBE) satellite [86]- orbited in 1989-1996. COBE made the most accurate measurements of the CMB frequency spectrum and confirmed it as being a black-body to within experimental limits. This made the CMB spectrum the most precisely measured black-body spectrum in nature. The CMB has a thermal black-body spectrum at a temperature of 2.725 K: the spectrum peaks in the microwave range frequency of 160.2 GHz, corresponding to a 1.9mmwavelength. The results of COBE inspired a series of ground- and balloon-based experiments, which measured CMB anisotropies on smaller scales over the next decade. During the 1990s, the first acoustic peak of the CMB power spectrum (see Figure 5.1) was measured with increasing sensitivity and by 2000 the BOOMERanG experiment [26] reported

  15. Tolley's industrial and commercial gas installation practice

    CERN Document Server

    Hazlehurst, John

    2010-01-01

    This is the third of three essential reference volumes for those concerned with the installation and servicing of domestic and industrial gas equipment. This volume explains the basic principles underlying the practical and theoretical aspects of installing and servicing gas appliances and associated equipment, from the basics of combustion, to burners, pressure and flow, transfer of heat, controls, as well as materials and processes, electrical aspects, and metering and measuring devices. Covering both Natural Gas and Liquefied Petroleum Gas, the many illustrations and worked examples include

  16. Design, fabrication and installation of irradiation facilities

    Energy Technology Data Exchange (ETDEWEB)

    Sim, Bong Shick; Kim, Y. S.; Lee, C. Y. and others

    1999-03-01

    The principal contents of this project are to design, fabricate and install the steady-state fuel test loop in HANARO for nuclear technology development. Procurement and fabrication of main equipment, licensing and technical review for fuel test loop have been performed during 2 years(1997, 1998) for this project. Following contents are described in the report. - Procurement and fabrication of the equipment, piping for OPS - IPS manufacture - License - Technical review and evaluation of the FTL facility. As besides, as these irradiation facilities will be installed in HANARO, review of safety concern, discussion with KINS for licensing and review ofHANARO interface have been performed respectively. (author)

  17. Solar heating system installed at Troy, Ohio

    Science.gov (United States)

    1980-01-01

    The completed system was composed of three basic subsystems: the collector system consisting of 3,264 square feet of Owens Illinois evacuated glass tube collectors; the storage system which included a 5,000 gallon insulated steel tank; and the distribution and control system which included piping, pumping and heat transfer components as well as the solemoid activated valves and control logic for the efficient and safe operation of the entire system. This solar heating system was installed in an existing facility and was, therefore, a retrofit system. Extracts from the site files, specifications, drawings, installation, operation and maintenance instructions are included.

  18. Design, fabrication and installation of irradiation facilities

    International Nuclear Information System (INIS)

    The principal contents of this project are to design, fabricate and install the steady-state fuel test loop in HANARO for nuclear technology development. Procurement and fabrication of main equipment, licensing and technical review for fuel test loop have been performed during 2 years(1997, 1998) for this project. Following contents are described in the report. - Procurement and fabrication of the equipment, piping for OPS - IPS manufacture - License - Technical review and evaluation of the FTL facility. As besides, as these irradiation facilities will be installed in HANARO, review of safety concern, discussion with KINS for licensing and review of HANARO interface have been performed respectively. (author)

  19. Buckling of Bucket Foundations During Installation

    DEFF Research Database (Denmark)

    Madsen, Søren

    There is a great politically will to expand the green energy market in these times. A proven green technology is wind turbines. Wind turbines have been installed in great numbers on land over the last decades. However, the current development in wind turbine design leads to larger turbine sizes...... in order to reduce the cost of energy. This limits the on land application due to transportation limitations and unwillingness from prospect neighbours. Thus, offshore wind energy started developing over the last couple of years. Although installing the wind turbines offshore resolves the before men tioned...

  20. Acoustic Signal Feature Extraction of Vehicle Targets

    Institute of Scientific and Technical Information of China (English)

    蓝金辉; 马宝华; 李科杰

    2002-01-01

    Acoustic signal feature extraction is an important part of target recognition. The mechanisms for producing acoustic signals and their propagation are analyzed to extract the features of the radiated noise from different targets. Analysis of the acoustic spectra of typical vehicle targets acquired outdoors shows that the vehicles can be classified based on the acoustic spectra and amplitudes.

  1. Acoustic cavitation movies

    Science.gov (United States)

    Crum, Lawrence A.

    2003-04-01

    Acoustic cavitation is a phenomenon that occurs on microsecond time scales and micron length scales, yet, it has many macroscopic manifestations. Accordingly, it is often difficult, at least for the author, to form realistic physical descriptions of the specific mechanisms through which it expresses itself in our macroscopic world. For example, there are still many who believe that cavitation erosion is due to the shock wave that is emitted by bubble implosion, rather than the liquid jet created on asymmetric collapse...and they may be right. Over the years, the author has accumulated a number of movies and high-speed photographs of cavitation activity, which he uses to form his own visual references. In the time allotted, he will show a number of these movies and photographs and discuss their relevance to existing technological problems. A limited number of CDs containing the presented materials will be available to interested individuals. [Work supported in part by the NIH, USAMRMC, and the ONR.

  2. Acoustic emission testing

    CERN Document Server

    Grosse, Christian U

    2008-01-01

    Acoustic Emission (AE) techniques have been studied in civil engineering for a long time. The techniques are recently going to be more and more applied to practical applications and to be standardized in the codes. This is because the increase of aging structures and disastrous damages due to recent earthquakes urgently demand for maintenance and retrofit of civil structures in service for example. It results in the need for the development of advanced and effective inspection techniques. Thus, AE techniques draw a great attention to diagnostic applications and in material testing. The book covers all levels from the description of AE basics for AE beginners (level of a student) to sophisticated AE algorithms and applications to real large-scale structures as well as the observation of the cracking process in laboratory specimen to study fracture processes.

  3. Acoustic Propagation Modeling for Marine Hydro-Kinetic Applications

    Science.gov (United States)

    Johnson, C. N.; Johnson, E.

    2014-12-01

    The combination of riverine, tidal, and wave energy have the potential to supply over one third of the United States' annual electricity demand. However, in order to deploy and test prototypes, and commercial installations, marine hydrokinetic (MHK) devices must meet strict regulatory guidelines that determine the maximum amount of noise that can be generated and sets particular thresholds for determining disturbance and injury caused by noise. An accurate model for predicting the propagation of a MHK source in a real-life hydro-acoustic environment has been established. This model will help promote the growth and viability of marine, water, and hydrokinetic energy by confidently assuring federal regulations are meet and harmful impacts to marine fish and wildlife are minimal. Paracousti, a finite difference solution to the acoustic equations, was originally developed for sound propagation in atmospheric environments and has been successfully validated for a number of different geophysical activities. The three-dimensional numerical implementation is advantageous over other acoustic propagation techniques for a MHK application where the domains of interest have complex 3D interactions from the seabed, banks, and other shallow water effects. A number of different cases for hydro-acoustic environments have been validated by both analytical and numerical results from canonical and benchmark problems. This includes a variety of hydrodynamic and physical environments that may be present in a potential MHK application including shallow and deep water, sloping, and canyon type bottoms, with varying sound speed and density profiles. With the model successfully validated for hydro-acoustic environments more complex and realistic MHK sources from turbines and/or arrays can be modeled.

  4. Theoretical detection ranges for acoustic based manatee avoidance technology.

    Science.gov (United States)

    Phillips, Richard; Niezrecki, Christopher; Beusse, Diedrich O

    2006-07-01

    The West Indian manatee (Trichechus manatus latirostris) has become endangered partly because of watercraft collisions in Florida's coastal waterways. To reduce the number of collisions, warning systems based upon detecting manatee vocalizations have been proposed. One aspect of the feasibility of an acoustically based warning system relies upon the distance at which a manatee vocalization is detectable. Assuming a mixed spreading model, this paper presents a theoretical analysis of the system detection capabilities operating within various background and watercraft noise conditions. This study combines measured source levels of manatee vocalizations with the modeled acoustic properties of manatee habitats to develop a method for determining the detection range and hydrophone spacing requirements for acoustic based manatee avoidance technologies. In quiet environments (background noise approximately 70 dB) it was estimated that manatee vocalizations are detectable at approximately 250 m, with a 6 dB detection threshold, In louder environments (background noise approximately 100dB) the detection range drops to 2.5 m. In a habitat with 90 dB of background noise, a passing boat with a maximum noise floor of 120 dB would be the limiting factor when it is within approximately 100 m of a hydrophone. The detection range was also found to be strongly dependent on the manatee vocalization source level. PMID:16875213

  5. ACOUSTIC DETECTING AND LOCATING GAS PIPE LINE INFRINGEMENT

    Energy Technology Data Exchange (ETDEWEB)

    John L. Loth; Gary J. Morris; George M. Palmer; Richard Guiler; Patrick Browning

    2004-10-31

    The extensive network of high-pressure natural gas transmission pipelines covering the United States provides an important infrastructure for our energy independence. Early detection of pipeline leaks and infringements by construction equipment, resulting in corrosion fractures, presents an important aspect of our national security policy. The National Energy Technology Laboratory Strategic Center for Natural Gas (SCVG) is and has been funding research on various applicable techniques. The WVU research team has focused on monitoring pipeline background acoustic signals generated and transmitted by gas flowing through the gas inside the pipeline. In case of a pipeline infringement, any mechanical impact on the pipe wall, or escape of high-pressure gas, generates acoustic signals traveling both up and down stream through the gas. Sudden changes in flow noise are detectable with a Portable Acoustic Monitoring Package (PAMP), developed under this contract. It incorporates a pressure compensating microphone and a signal- recording device. Direct access to the gas inside the line is obtained by mounting such a PAMP, with a 1/2 inch NPT connection, to a pipeline pressure port found near most shut-off valves. An FFT of the recorded signal subtracted by that of the background noise recorded one-second earlier appears to sufficiently isolate the infringement signal to allow source interpretation. Using cell phones for data downloading might allow a network of such 1000-psi rated PAMP's to acoustically monitor a pipeline system and be trained by neural network software to positively identify and locate any pipeline infringement.

  6. ACOUSTIC DETECTING AND LOCATING GAS PIPE LINE INFRINGEMENT

    Energy Technology Data Exchange (ETDEWEB)

    John L. Loth; Gary J. Morris; George M. Palmer; Richard Guiler; Patrick Browning

    2004-12-01

    The extensive network of high-pressure natural gas transmission pipelines covering the United States provides an important infrastructure for our energy independence. Early detection of pipeline leaks and infringements by construction equipment, resulting in corrosion fractures, presents an important aspect of our national security policy. The National Energy Technology Laboratory Strategic Center for Natural Gas (SCVG) is and has been funding research on various applicable techniques. The WVU research team has focused on monitoring pipeline background acoustic signals generated and transmitted by gas flowing through the gas inside the pipeline. In case of a pipeline infringement, any mechanical impact on the pipe wall, or escape of high-pressure gas, generates acoustic signals traveling both up and down stream through the gas. Sudden changes in flow noise are detectable with a Portable Acoustic Monitoring Package (PAMP), developed under this contract. It incorporates a pressure compensating microphone and a signal- recording device. Direct access to the gas inside the line is obtained by mounting such a PAMP, with a 1/2 inch NPT connection, to a pipeline pressure port found near most shut-off valves. An FFT of the recorded signal subtracted by that of the background noise recorded one-second earlier appears to sufficiently isolate the infringement signal to allow source interpretation. Using cell phones for data downloading might allow a network of such 1000-psi rated PAMP's to acoustically monitor a pipeline system and be trained by neural network software to positively identify and locate any pipeline infringement.

  7. 75 FR 77017 - Nextera Energy Seabrook, LLC Seabrook Station Independent Spent Fuel Storage Installation; Exemption

    Science.gov (United States)

    2010-12-10

    ... COMMISSION Nextera Energy Seabrook, LLC Seabrook Station Independent Spent Fuel Storage Installation; Exemption 1.0 Background NextEra Energy Seabrook, LLC (NextEra, the licensee) is the holder of Facility..., subpart K, a general license is issued for the storage of spent fuel in an independent spent fuel...

  8. Inventory of chemical releases of nuclear installations in the North-Cotentin; Inventaire des rejets chimiques des installations nucleaires du Nord-Cotentin

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-05-15

    The nuclear installations concerned by this study are Cogema La Hague, the Flamanville nuclear power plant, the Manche plant and the National Navy of Cherbourg.The objective followed by the ' source term ' work group has consisted in counting and examining the whole of existing measures relative to the releases of chemical substances in the liquid and gaseous effluents. Then because of the lack of measures for the operation first years of installations, the work group has estimated the order of magnitude of these chemical releases (essentially for Cogema La Hague). This report presents a review of the literature looking at the background levels of chemicals in different environmental compartments: air, soil, plants and animals products. these values have been summarized here to be available for comparisons with concentrations input by the North Cotentin nuclear installations, calculated by the G.R.N.C. (radioecology group of Nord Cotentin)

  9. Acoustic Issues in Human Spaceflight

    Science.gov (United States)

    Clark, Jonathan B.

    2001-01-01

    NASA is concerned about acute effect of sound on crew performance on International Space Station (ISS), and is developing strategies to assess and reduce acute, chronic, and delayed effects of sound. High noise levels can cause headaches, irritation, fatigue, impaired sleep, headache, and tinnitus and have resulted in an inability to hear alarms. Speech intelligibility may be more impaired for crew understanding non-native language in a noisy environment. No hearing loss occurred, but significant effects on crew performance and communication occurred. Permanent Threshold Shifts (PTS) have not been observed in the US shuttle program. Russian specification for noise in spacecraft is 60 dBA (awake) and 50 dBA (asleep) while the U.S. noise specification on ISS is NC 50 (awake) and NC 40 (asleep) with a 85 dBA hazard limit. Background noise levels of ISS modules have measured 56-69 dBA. Treadmill exercise operations measure 77 dBA. Alarms are required to be 20 dBA above ambient. Hearing protection is recommended when noise exceeds 60 dB 24 hour Leq. Countermeasures include hearing protection and design/ engineering controls. Advanced composite materials with excellent low frequency attenuation properties could be applied as a barrier protection around noisy equipment, or used on personal protective equipment worn by the crew. Hearing protection countermeasures include foam ear inserts, passive muff headsets, and active noise reduction headsets. Oto-acoustic emissions (OAE) could be used to monitor effectiveness of hearing protection countermeasures and tailor hearing protection countermeasures to individual crewmembers. Micro-gravity, vibration, toxic fumes, air quality/composition, stress, temperature, physical exertion or some combination of the above factors may have interacted with moderate long-term noise exposure to cause significant hearing loss. Longitudinal studies will need to address what co-morbidity factors, such as radiation, toxicology, microgravity

  10. Effects of subsampling of passive acoustic recordings on acoustic metrics.

    Science.gov (United States)

    Thomisch, Karolin; Boebel, Olaf; Zitterbart, Daniel P; Samaran, Flore; Van Parijs, Sofie; Van Opzeeland, Ilse

    2015-07-01

    Passive acoustic monitoring is an important tool in marine mammal studies. However, logistics and finances frequently constrain the number and servicing schedules of acoustic recorders, requiring a trade-off between deployment periods and sampling continuity, i.e., the implementation of a subsampling scheme. Optimizing such schemes to each project's specific research questions is desirable. This study investigates the impact of subsampling on the accuracy of two common metrics, acoustic presence and call rate, for different vocalization patterns (regimes) of baleen whales: (1) variable vocal activity, (2) vocalizations organized in song bouts, and (3) vocal activity with diel patterns. To this end, above metrics are compared for continuous and subsampled data subject to different sampling strategies, covering duty cycles between 50% and 2%. The results show that a reduction of the duty cycle impacts negatively on the accuracy of both acoustic presence and call rate estimates. For a given duty cycle, frequent short listening periods improve accuracy of daily acoustic presence estimates over few long listening periods. Overall, subsampling effects are most pronounced for low and/or temporally clustered vocal activity. These findings illustrate the importance of informed decisions when applying subsampling strategies to passive acoustic recordings or analyses for a given target species. PMID:26233026

  11. Hybrid optical and acoustic force based sorting

    Science.gov (United States)

    O'Mahoney, Paul; Brodie, Graham W.; Wang, Han; Demore, Christine E. M.; Cochran, Sandy; Spalding, Gabriel C.; MacDonald, Michael P.

    2014-09-01

    We report the combined use of optical sorting and acoustic levitation to give particle sorting. Differing sizes of microparticles are sorted optically both with and without the aid of acoustic levitation, and the results compared to show that the use of acoustic trapping can increase sorting efficiency. The use of a transparent ultrasonic transducer is also shown to streamline the integration of optics and acoustics. We also demonstrate the balance of optical radiation pressure and acoustic levitation to achieve vertical sorting.

  12. First detector installed inside the ALICE solenoid...

    CERN Multimedia

    2006-01-01

    ALICE's emblematic red magnet welcomed its first detector on 23 September, when the array of seven Cherenkov detectors, named HMPID, was successfully installed. ALICE team members standing in front of the completed HMPID detector.The red magnet, viewed from its front opening. The HMPID unit, seen from the back (top right corner of photo) is placed on a frame and lifted onto a platform during the installation. After the installation of the ACORDE scintillator array and the muon trigger and tracking chambers, the ALICE collaboration fitted the first detector inside the solenoid. The HMPID, for High Momentum Particle Identification, was installed at the 2 o'clock position in the central and most external region of the space frame, just below the solenoid yoke. It will be used to extend the hadron identification capability of the ALICE experiment up to 5 GeV/c, thus complementing the reach of the other particle identification systems (ITS, TPC and TOF). The HMPID is a Ring Imaging Cherenkov (RICH) detector in a...

  13. 46 CFR 58.16-18 - Installation.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Installation. 58.16-18 Section 58.16-18 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MAIN AND AUXILIARY MACHINERY AND... ventilation consisting of a fresh air inlet pipe and an exhaust pipe both entering through the top of...

  14. Installation of the LHC transfer lines begins

    CERN Multimedia

    2003-01-01

    On 19 February, the very first magnet was installed in one of the two tunnels that will house the transfer lines leading to the LHC. This magnet, recycled from a previous facility, was transported and positioned using a novel system designed for conveying large objects through narrow tunnels.

  15. Computer systems for nuclear installation data control

    International Nuclear Information System (INIS)

    The computer programs developed by Divisao de Instalacoes Nucleares (DIN) from Brazilian CNEN for data control on nuclear installations in Brazil are presented. The following computer programs are described: control of registered companies, control of industrial sources, irradiators and monitors; control of liable person; control of industry irregularities; for elaborating credence tests; for shielding analysis; control of waste refuge

  16. Public Address Systems. Specifications - Installation - Operation.

    Science.gov (United States)

    Palmer, Fred M.

    Provisions for public address in new construction of campus buildings (specifications, installations, and operation of public address systems), are discussed in non-technical terms. Consideration is given to microphones, amplifiers, loudspeakers and the placement and operation of various different combinations. (FS)

  17. Licensing system for primary category radioactive installations

    International Nuclear Information System (INIS)

    The development of a licensing system for primary category radioactive installations is described, which aims to satisfy the needs of the Chilean Nuclear Energy Commission's Department of Nuclear and Radiological Safety, particularly the sections for Licensing Outside Radioactive Installations and Safety Control. This system involves the identification, control and inspection of the installations, their personnel and connected activities, for the purpose of protecting the population's health and the environment. Following the basic cycle methodology, a systems analysis and engineering stage was prepared, establishing the functions of the system's elements and defining the requirements, based on interviews with the users. This stage was followed by the design stage, focusing on the data structure, the software architecture and the procedural detail. The codification stage followed, which translated the design into legible machine-readable format. In the testing stage, the entries that were defined were proven to produce the expected data. Finally and operational and maintenance stage was developed, when the system was installed and put to use. All the above generated a useful system for the Licensing section of the Department of Nuclear and Radiological Safety, since it provides faster and easier access to information. A project is described that introduces new development tools in the Computer department following standards established by the C.CH.E.N. (author)

  18. Installation of first magnet at LEP

    CERN Multimedia

    1987-01-01

    Speech by French Prime Minister Jacques Chirac following the installation of the first magnet at LEP on 4 June 1987. From left to right: Herwig Schopper, CERN Director-General; Jacques Chirac; Swiss President Pierre Aubert and Wolfgang Kummer, President of the CERN Council.

  19. Installations solaires photovoltaïques

    CERN Document Server

    2014-01-01

    Cet ouvrage présente les règles de conception et de mise en œuvre des installations photovoltaïques raccordées au réseau public de distribution à basse tension. Il s’applique aux bâtiments neufs et existants et concerne non seulement les petites installations résidentielles, d’une puissance de l’ordre de quelques kWc, mais aussi celles des bâtiments collectifs, tertiaires ou agricoles. Il traite successivement : - des fondamentaux de l'énergie solaire photovoltaïque (gisement solaire, principe de la conversion, composants d'une installation...) ; - du dimensionnement de l'installation (choix des matériels, règles de conception, estimation de l'énergie récupérable...) ; - de sa mise en oeuvre (travail en hauteur, habilitation électrique, mise en service, maintenance...) ; - des démarches administratives nécessaires (aides financières, accès au réseau de distribution, vente de l'électricité produite...).

  20. Tow techniques for marine pipeline installation

    OpenAIRE

    Fernández, M. L.

    1981-01-01

    Tow techniques for marine pipelines frequently offer competitive and commercially attactive solutions over other installation methods and, on occasion, may represent the only alternative to traditional techniques. An assessment is also made of where each tow method is applicable and technically feasible.

  1. Tow techniques for marine pipeline installation

    NARCIS (Netherlands)

    Fernández, M.L.

    1981-01-01

    Tow techniques for marine pipelines frequently offer competitive and commercially attactive solutions over other installation methods and, on occasion, may represent the only alternative to traditional techniques. An assessment is also made of where each tow method is applicable and technically feas

  2. 14 CFR 171.29 - Installation requirements.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Installation requirements. 171.29 Section 171.29 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) NAVIGATIONAL FACILITIES NON-FEDERAL NAVIGATION FACILITIES Nondirectional Radio Beacon Facilities §...

  3. 14 CFR 171.209 - Installation requirements.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Installation requirements. 171.209 Section 171.209 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) NAVIGATIONAL FACILITIES NON-FEDERAL NAVIGATION FACILITIES VHF Marker Beacons § 171.209...

  4. Geodetic alignment of laser power installations

    International Nuclear Information System (INIS)

    Main problems occuring in applied geodesy under initial alignment of laser power installation optical channel are considered. Attention is paid to alignment of lens beamguide telescopic pairs and alignment quality control. Methods and means of geodetic measurements under alignment are indicated. Conclusions are made about the degree of working through certain aspects of the problem

  5. On the Modelling of Pile Installation

    NARCIS (Netherlands)

    Dijkstra, J.

    2009-01-01

    This thesis introduces two different types of physical model tests to investigate the stress and density change in the soil during installation of a jacked pile as well as two numerical modelling approaches to model the same process in a finite element code capable of large deformations.

  6. Estimating suspended sediment using acoustics in a fine-grained riverine system, Kickapoo Creek at Bloomington, Illinois

    Science.gov (United States)

    Manaster, Amanda D.; Domanski, Marian M.; Straub, Timothy D.; Boldt, Justin A.

    2016-08-18

    Acoustic technologies have the potential to be used as a surrogate for measuring suspended-sediment concentration (SSC). This potential was examined in a fine-grained (97-100 percent fines) riverine system in central Illinois by way of installation of an acoustic instrument. Acoustic data were collected continuously over the span of 5.5 years. Acoustic parameters were regressed against SSC data to determine the accuracy of using acoustic technology as a surrogate for measuring SSC in a fine-grained riverine system. The resulting regressions for SSC and sediment acoustic parameters had coefficients of determination ranging from 0.75 to 0.97 for various events and configurations. The overall Nash-Sutcliffe model-fit efficiency was 0.95 for the 132 observed and predicted SSC values determined using the sediment acoustic parameter regressions. The study of using acoustic technologies as a surrogate for measuring SSC in fine-grained riverine systems is ongoing. The results at this site are promising in the realm of surrogate technology.

  7. The Swiss nuclear installations. Annual report 1993

    International Nuclear Information System (INIS)

    Surveillance of the Swiss nuclear installations with regard to nuclear safety, including radiation protection, is among the tasks of the Swiss Federal Nuclear Safety Inspectorate (HSK). Five nuclear power plants are operational in Switzerland: the three units Beznau I and II and Muehleberg with electrical capacities in the range of 300 to 400 MWe, and the two units Goesgen and Leibstadt with capacities between 900 and 1200 MWe. These are light water reactors; at Beznau and Goesgen of the PWR type, and at Muehleberg and Leibstadt of the BWR type. Research reactors of thermal capacities below 10 MWth are operational at the Paul Scherrer Institute (PSI), at the Swiss Federal Institute of Technology Lausanne and at the University of Basel. Further subject to HSK's supervision are all activities at PSI involving nuclear fuel or ionizing radiation, the shut-down experimental reactor of Lucens, the exploration of final disposal facilities for radwaste and the interim radwaste storage facilities in Switzerland. The report first deals with the nuclear power and covers, in individual sections, the aspects of installation safety, radiation protection as well as personnel and organization, and the resulting overall impression from the point of view of HSK. In chapter 5, the corresponding information is given for research installations. Chapter 6, on radwaste disposal, is dedicated to the treatment of waste, waste from reprocessing, interim storage and exploration by NAGRA. In chapter 7, the status of emergency planning in the nuclear power plants' proximity is reported. Certificates issued for the transport of radioactive materials are dealt with in chapter 8. Finally chapter 9 goes into general questions relating to the safety of nuclear installations. All in all, the safety of operation of the Swiss nuclear installations, in the period of 1993, is judged as good by HSK. (author) 10 figs., 11 tabs

  8. The Swiss nuclear installations. Annual report 1994

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-06-01

    Surveillance of the Swiss nuclear installations with regard to nuclear safety, including radiation protection, is among the tasks of the Swiss Federal Nuclear Safety Inspectorate (HSK). Five nuclear power plants are operational in Switzerland: the three units Beznau I and II and Muehleberg with electrical capacities in the range of 300 to 400 MWe, and the two units Goesgen and Leibstadt with capacities between 900 and 1200 MWe. These are light water reactors; at Beznau and Goesgen of the PWR type, and at Muehleberg and Leibstadt of the BWR type. Research reactors of thermal capacities below 10 MWth are operational at the Paul Scherrer Institute (PSI), at the Swiss Federal Institute of Technology Lausanne and at the University of Basel. Further subject to HSK`s supervision are all activities at PSI involving nuclear fuel or ionizing radiation, the shut-down experimental reactor of Lucens, the exploration, in Switzerland, of final disposal facilities for radwaste and the interim radwaste storage facilities. The report first deals with the nuclear power and covers, in individual sections, the aspects of installation safety, radiation protection as well as personnel and organization, and the resulting overall impression from the point of view of HSK. In chapter 5, the corresponding information is given for research installations. Chapter 6, on radwaste disposal, is dedicated to the treatment of waste, waste from reprocessing, interim storage and exploration by NAGRA. In chapter 7, the status of emergency planning in the nuclear power plants` proximity is reported. Certificates issued for the transport of radioactive materials are dealt with in chapter 8. Finally chapter 9 goes into general questions relating to the safety of nuclear installations. All in all, the safety of operation of the Swiss nuclear installations, in the period of 1994, is judged as good by HSK. (author) 11 figs., 13 tabs.

  9. The Swiss nuclear installations. Annual report 1993

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-08-01

    Surveillance of the Swiss nuclear installations with regard to nuclear safety, including radiation protection, is among the tasks of the Swiss Federal Nuclear Safety Inspectorate (HSK). Five nuclear power plants are operational in Switzerland: the three units Beznau I and II and Muehleberg with electrical capacities in the range of 300 to 400 MWe, and the two units Goesgen and Leibstadt with capacities between 900 and 1200 MWe. These are light water reactors; at Beznau and Goesgen of the PWR type, and at Muehleberg and Leibstadt of the BWR type. Research reactors of thermal capacities below 10 MWth are operational at the Paul Scherrer Institute (PSI), at the Swiss Federal Institute of Technology Lausanne and at the University of Basel. Further subject to HSK`s supervision are all activities at PSI involving nuclear fuel or ionizing radiation, the shut-down experimental reactor of Lucens, the exploration of final disposal facilities for radwaste and the interim radwaste storage facilities in Switzerland. The report first deals with the nuclear power and covers, in individual sections, the aspects of installation safety, radiation protection as well as personnel and organization, and the resulting overall impression from the point of view of HSK. In chapter 5, the corresponding information is given for research installations. Chapter 6, on radwaste disposal, is dedicated to the treatment of waste, waste from reprocessing, interim storage and exploration by NAGRA. In chapter 7, the status of emergency planning in the nuclear power plants` proximity is reported. Certificates issued for the transport of radioactive materials are dealt with in chapter 8. Finally chapter 9 goes into general questions relating to the safety of nuclear installations. All in all, the safety of operation of the Swiss nuclear installations, in the period of 1993, is judged as good by HSK. (author) 10 figs., 11 tabs.

  10. Frequency Steered Acoustic Transducer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Small Business Innovation Research Phase II project is to fabricate, characterize, and verify performance of a new type of frequency steered acoustic...

  11. Frequency Steered Acoustic Transducer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Small Business Innovation Research Phase I project is to develop, fabricate, and characterize a novel frequency steered acoustic transducer (FSAT) for the...

  12. Reverberant Acoustic Test Facility (RATF)

    Data.gov (United States)

    Federal Laboratory Consortium — The very large Reverberant Acoustic Test Facility (RATF) at the NASA Glenn Research Center (GRC), Plum Brook Station, is currently under construction and is due to...

  13. Cryogenic Acoustic Suppression Testing Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed project will explore and test the feasibility and effectiveness of using a cryogenic fluid (liquid nitrogen) to facilitate acoustic suppression in a...

  14. JEM-X background models

    DEFF Research Database (Denmark)

    Huovelin, J.; Maisala, S.; Schultz, J.;

    2003-01-01

    revolution 41 of INTEGRAL. Total observing time used for the analysis was 216 502 s, with the average of 25 cps of background for each of the two JEM-X telescopes. JEM-X1 showed slightly higher average background intensity than JEM-X2. The detectors were stable during the long exposures, and weak orbital...... phase dependence in the background outside radiation belts was observed. The analysis yielded an average of 5 cps for the diffuse background, and 20 cps for the instrument background. The instrument background was found highly dependent on position, both for spectral shape and intensity. Diff use...... background was enhanced in the central area of a detector, and it decreased radially towards the edge, with a clear vignetting effect for both JEM-X units. The instrument background was weakest in the central area of a detector and showed a steep increase at the very edges of both JEM-X detectors, with...

  15. NEAR-FIELD ACOUSTIC HOLOGRAPHY FOR SEMI-FREE ACOUSTIC FIELD BASED ON WAVE SUPERPOSITION APPROACH

    Institute of Scientific and Technical Information of China (English)

    LI Weibing; CHEN Jian; YU Fei; CHEN Xinzhao

    2006-01-01

    In the semi-free acoustic field, the actual acoustic pressure at any point is composed of two parts: The direct acoustic pressure and the reflected acoustic pressure. The general acoustic holographic theories and algorithms request that there is only the direct acoustic pressure contained in the pressure at any point on the hologram surface, consequently, they cannot be used to reconstruct acoustic source and predict acoustic field directly. To take the reflected pressure into consideration, near-field acoustic holography for semi-free acoustic field based on wave superposition approach is proposed to realize the holographic reconstruction and prediction of the semi-free acoustic field, and the wave superposition approach is adopted as a holographic transform algorithm. The proposed theory and algorithm are realized and verified with a numerical example,and the drawbacks of the general theories and algorithms in the holographic reconstruction and prediction of the semi-free acoustic field are also demonstrated by this numerical example.

  16. Acoustic Rectification in Dispersive Media

    Science.gov (United States)

    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.

  17. Simplified Rotation In Acoustic Levitation

    Science.gov (United States)

    Barmatz, M. B.; Gaspar, M. S.; Trinh, E. H.

    1989-01-01

    New technique based on old discovery used to control orientation of object levitated acoustically in axisymmetric chamber. Method does not require expensive equipment like additional acoustic drivers of precisely adjustable amplitude, phase, and frequency. Reflecting object acts as second source of sound. If reflecting object large enough, close enough to levitated object, or focuses reflected sound sufficiently, Rayleigh torque exerted on levitated object by reflected sound controls orientation of object.

  18. Stable And Oscillating Acoustic Levitation

    Science.gov (United States)

    Barmatz, Martin B.; Garrett, Steven L.

    1988-01-01

    Sample stability or instability determined by levitating frequency. Degree of oscillation of acoustically levitated object along axis of levitation chamber controlled by varying frequency of acoustic driver for axis above or below frequency of corresponding chamber resonance. Stabilization/oscillation technique applied in normal Earth gravity, or in absence of gravity to bring object quickly to rest at nominal levitation position or make object oscillate in desired range about that position.

  19. Study Acoustic Emissions from Composites

    Science.gov (United States)

    Walker, James; Workman,Gary

    1998-01-01

    The purpose of this work will be to develop techniques for monitoring the acoustic emissions from carbon epoxy composite structures at cryogenic temperatures. Performance of transducers at temperatures ranging from ambient to cryogenic and the characteristics of acoustic emission from composite structures will be studied and documented. This entire effort is directed towards characterization of structures used in NASA propulsion programs such as the X-33.

  20. Acoustic diagnosis of mechanical fault feature based on reference signal frequency domain semi-blind extraction

    OpenAIRE

    Zeguang YI; Pan, Nan; Liu, Feng

    2015-01-01

    Aiming at fault diagnosis problems caused by complex machinery parts, serious background noises and the application limitations of traditional blind signal processing algorithm to the mechanical acoustic signal processing, a failure acoustic diagnosis based on reference signal frequency domain semi-blind extraction is proposed. Key technologies are introduced: Based on frequency-domain blind deconvolution algorithm, the artificial fish swarm algorithm which is good for global optimization is ...

  1. Acoustics and breathing in wind instrument during musical playing : flutes application

    OpenAIRE

    Vauthrin, Camille

    2015-01-01

    This thesis presents an acoustical study of flute-like instruments, which is developed by the analysis of flautist’s breathing. The flautist acquires during his musical background an expert control of his instrument. The control developed by the musician directly depends on the freedoms and constraints provided by the musician musical expertise, his respiratory physiology, the musical tasks and the acoustic behavior of the flute. Studying the playing techniques requires us to consider the fla...

  2. Using Simulation to Analyze Acoustic Environments

    Science.gov (United States)

    Wood, Eric J.

    2016-01-01

    One of the main projects that was worked on this semester was creating an acoustic model for the Advanced Space Suit in Comsol Multiphysics. The geometry tools built into the software were used to create an accurate model of the helmet and upper torso of the suit. After running the simulation, plots of the sound pressure level within the suit were produced, as seen below in Figure 1. These plots show significant nulls which should be avoided when placing microphones inside the suit. In the future, this model can be easily adapted to changes in the suit design to determine optimal microphone placements and other acoustic properties. Another major project was creating an acoustic diverter that will potentially be used to route audio into the Space Station's Node 1. The concept of the project was to create geometry to divert sound from a neighboring module, the US Lab, into Node 1. By doing this, no new audio equipment would need to be installed in Node 1. After creating an initial design for the diverter, analysis was performed in Comsol in order to determine how changes in geometry would affect acoustic performance, as shown in Figure 2. These results were used to produce a physical prototype diverter on a 3D printer. With the physical prototype, testing was conducted in an anechoic chamber to determine the true effectiveness of the design, as seen in Figure 3. The results from this testing have been compared to the Comsol simulation results to analyze how closely the Comsol results are to real-world performance. While the Comsol results do not seem to closely resemble the real world performance, this testing has provided valuable insight into how much trust can be placed in the results of Comsol simulations. A final project that was worked on during this tour was the Audio Interface Unit (AIU) design for the Orion program. The AIU is a small device that will be used for as an audio communication device both during launch and on-orbit. The unit will have functions

  3. Opto-acoustic cell permeation

    Energy Technology Data Exchange (ETDEWEB)

    Visuri, S R; Heredia, N

    2000-03-09

    Optically generated acoustic waves have been used to temporarily permeate biological cells. This technique may be useful for enhancing transfection of DNA into cells or enhancing the absorption of locally delivered drugs. A diode-pumped frequency-doubled Nd:YAG laser operating at kHz repetition rates was used to produce a series of acoustic pulses. An acoustic wave was formed via thermoelastic expansion by depositing laser radiation into an absorbing dye. Generated pressures were measured with a PVDF hydrophone. The acoustic waves were transmitted to cultured and plated cells. The cell media contained a selection of normally- impermeable fluorescent-labeled dextran dyes. Following treatment with the opto-acoustic technique, cellular incorporation of dyes, up to 40,000 Molecular Weight, was noted. Control cells that did not receive opto-acoustic treatment had unremarkable dye incorporation. Uptake of dye was quantified via fluorescent microscopic analysis. Trypan Blue membrane exclusion assays and fluorescent labeling assays confirmed the vitality of cells following treatment. This method of enhanced drug delivery has the potential to dramatically reduce required drug dosages and associated side effects and enable revolutionary therapies.

  4. 24 CFR 3286.105 - Requirement for installer licensing.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Requirement for installer licensing. 3286.105 Section 3286.105 Housing and Urban Development Regulations Relating to Housing and Urban...-Administered States § 3286.105 Requirement for installer licensing. (a) Installer Licensing. The installer...

  5. 46 CFR 105.25-10 - Cargo pumping installation.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Cargo pumping installation. 105.25-10 Section 105.25-10 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS... Installed Below Decks § 105.25-10 Cargo pumping installation. (a) Cargo pumps shall not be installed in...

  6. Prediction of acoustic comfort and acoustic silence in Goan Catholic churches

    OpenAIRE

    Menino A. S. M. P. Tavares; S. Rajagopalan; Satish J. Sharma; António P. O. Carvalho

    2009-01-01

    Acoustic Comfort and Acoustic Silence are determinants of tranquility in a worship space. The results presented here are part of a study that investigates the behaviour of acoustically constituted worship parameters in six Catholic churches (Goa, India). Acoustic comfort is quantified through an Acoustic Comfort Impression Index which measures the net comfort induced through the optimization of the desired subjective acoustic impressions for different types of music and different music source...

  7. Wind Turbine Acoustics

    Science.gov (United States)

    Hubbard, Harvey H.; Shepherd, Kevin P.

    2009-01-01

    Wind turbine generators, ranging in size from a few kilowatts to several megawatts, are producing electricity both singly and in wind power stations that encompass hundreds of machines. Many installations are in uninhabited areas far from established residences, and therefore there are no apparent environmental impacts in terms of noise. There is, however, the potential for situations in which the radiated noise can be heard by residents of adjacent neighborhoods, particularly those neighborhoods with low ambient noise levels. A widely publicized incident of this nature occurred with the operation of the experimental Mod-1 2-MW wind turbine, which is described in detail elsewhere. Pioneering studies which were conducted at the Mod-1 site on the causes and remedies of noise from wind turbines form the foundation of much of the technology described in this chapter.

  8. Acoustic Behaviour of Bottlenose Dolphins and Pilot Whales

    OpenAIRE

    Jensen, Frants Havmand

    2011-01-01

    Here I summarize the most important findings of my PhD thesis. My dissertation consists of 9 chapters: An introduction, 3 peer-reviewed papers (2 published, 1 accepted), 4 manuscripts prepared for submission, and a progress report of an ongoing study. The introduction serves as a broad background and review for the topics addressed in the subsequent chapters, with discussions of these chapters where appropriate. In this thesis, I have undertaken a series of acoustic studies on two species of ...

  9. Supergravity backgrounds and symmetry superalgebras

    CERN Document Server

    Ertem, Ümit

    2016-01-01

    We consider the bosonic sectors of supergravity theories in ten and eleven dimensions which correspond to the low energy limits of string theories and M-theory. The solutions of supergravity field equations are known as supergravity backgrounds and the number of preserved supersymmetries in those backgrounds are determined by Killing spinors. We provide some examples of supergravity backgrounds which preserve different fractions of supersymmetry. An important invariant for the characterization of supergravity backgrounds is their Killing superalgebras which are constructed out of Killing vectors and Killing spinors of the background. After constructing Killing superalgebras of some special supergravity backgrounds, we discuss about the possibilities of the extensions of these superalgebras to include the higher degree hidden symmetries of the background.

  10. ELABORATION OF HIGH-VOLTAGE PULSE INSTALLATIONS AND PROVIDING THEIR OPERATION PROTECTIVE MEASURES

    Directory of Open Access Journals (Sweden)

    А. М. Hashimov

    2016-01-01

    Full Text Available The article presents design engineering methods for the high-voltage pulse installations of technological purpose for disinfection of drinking water, sewage, and edible liquids by high field micro- and nanosecond pulsing exposure. Designing potentialities are considered of the principal elements of the high-voltage part and the discharge circuit of the installations towards assuring the best efficient on-load utilization of the source energy and safe operation of the high-voltage equipment. The study shows that for disinfection of drinking water and sewage it is expedient to apply microsecond pulse actions causing the electrohydraulic effect in aqueous media with associated complex of physical processes (ultraviolet emission, generation of ozone and atomic oxygen, mechanical compression waves, etc. having detrimental effect on life activity of the microorganisms. In case of disinfecting edible liquids it is recommended to use the nanosecond pulses capable of straight permeating the biological cell nucleus, inactivating it. Meanwhile, the nutritive and biological values of the foodstuffs are saved and their organoleptic properties are improved. It is noted that in elaboration process of high-frequency pulse installations special consideration should be given to issues of the operating personnel safety discipline and securing conditions for the entire installation uninterrupted performance. With this objective in view the necessary requirements should be fulfilled on shielding the high- and low-voltage installation parts against high-frequency electromagnetic emissions registered by special differential sensors. Simultaneously, the abatement measures should be applied on the high-voltage equipment operational noise level. The authors offer a technique for noise abatement to admissible levels (lower than 80 dB A by means of coating the inside surface with shielded enclosure of densely-packed abutting sheets of porous electro-acoustic insulating

  11. Information handbook on independent spent fuel storage installations

    Energy Technology Data Exchange (ETDEWEB)

    Raddatz, M.G.; Waters, M.D.

    1996-12-01

    In this information handbook, the staff of the U.S. Nuclear Regulatory Commission describes (1) background information regarding the licensing and history of independent spent fuel storage installations (ISFSIs), (2) a discussion of the licensing process, (3) a description of all currently approved or certified models of dry cask storage systems (DCSSs), and (4) a description of sites currently storing spent fuel in an ISFSI. Storage of spent fuel at ISFSIs must be in accordance with the provisions of 10 CFR Part 72. The staff has provided this handbook for information purposes only. The accuracy of any information herein is not guaranteed. For verification or for more details, the reader should refer to the respective docket files for each DCSS and ISFSI site. The information in this handbook is current as of September 1, 1996.

  12. Acoustic Characterization of Compact Jet Engine Simulator Units

    Science.gov (United States)

    Doty, Michael J.; Haskin, Henry H.

    2013-01-01

    Two dual-stream, heated jet, Compact Jet Engine Simulator (CJES) units are designed for wind tunnel acoustic experiments involving a Hybrid Wing Body (HWB) vehicle. The newly fabricated CJES units are characterized with a series of acoustic and flowfield investigations to ensure successful operation with minimal rig noise. To limit simulator size, consistent with a 5.8% HWB model, the CJES units adapt Ultra Compact Combustor (UCC) technology developed at the Air Force Research Laboratory. Stable and controllable operation of the combustor is demonstrated using passive swirl air injection and backpressuring of the combustion chamber. Combustion instability tones are eliminated using nonuniform flow conditioners in conjunction with upstream screens. Through proper flow conditioning, rig noise is reduced by more than 20 dB over a broad spectral range, but it is not completely eliminated at high frequencies. The low-noise chevron nozzle concept designed for the HWB test shows expected acoustic benefits when installed on the CJES unit, and consistency between CJES units is shown to be within 0.5 dB OASPL.

  13. Acoustic Signal based Traffic Density State Estimation using SVM

    Directory of Open Access Journals (Sweden)

    Prashant Borkar

    2013-06-01

    Full Text Available Based on the information present in cumulative acoustic signal acquired from a roadside-installed single microphone, this paper considers the problem of vehicular traffic density state estimation. The occurrence and mixture weightings of traffic noise signals (Tyre, Engine, Air Turbulence, Exhaust, and Honks etc are determined by the prevalent traffic density conditions on the road segment. In this work, we extract the short-term spectral envelope features of the cumulative acoustic signals using MFCC (Mel-Frequency Cepstral Coefficients. Support Vector Machines (SVM is used as classifier is used to model the traffic density state as Low (40 Km/h and above, Medium (20-40 Km/h, and Heavy (0-20 Km/h. For the developing geographies where the traffic is non-lane driven and chaotic, other techniques (magnetic loop detectors are inapplicable. SVM classifier with different kernels are used to classify the acoustic signal segments spanning duration of 20–40 s, which results in average classification accuracy of 96.67% for Quadratic kernel function and 98.33% for polynomial kernel function, when entire frames are considered for classification.

  14. Acoustic module of the Acquabona (Italy debris flow monitoring system

    Directory of Open Access Journals (Sweden)

    A. Galgaro

    2005-01-01

    Full Text Available Monitoring of debris flows aimed to the assessment of their physical parameters is very important both for theoretical and practical purposes. Peak discharge and total volume of debris flows are crucial for designing effective countermeasures in many populated mountain areas where losses of lives and property damage could be avoided. This study quantifies the relationship between flow depth, acoustic amplitude of debris flow induced ground vibrations and front velocity in the experimental catchment of Acquabona, Eastern Dolomites, Italy. The analysis of data brought about the results described in the following. Debris flow depth and amplitude of the flow-induced ground vibrations show a good positive correlation. Estimation of both mean front velocity and peak discharge can be simply obtained monitoring the ground vibrations, through geophones installed close to the flow channel; the total volume of debris flow can be so directly estimated from the integral of the ground vibrations using a regression line. The application of acoustic technique to debris flow monitoring seems to be of the outmost relevance in risk reduction policies and in the correct management of the territory. Moreover this estimation is possible in other catchments producing debris flows of similar characteristics by means of their acoustic characterisation through quick and simple field tests (Standard Penetration Tests and seismic refraction surveys.

  15. Acoustic module of the Acquabona (Italy) debris flow monitoring system

    Science.gov (United States)

    Galgaro, A.; Tecca, P. R.; Genevois, R.; Deganutti, A. M.

    2005-02-01

    Monitoring of debris flows aimed to the assessment of their physical parameters is very important both for theoretical and practical purposes. Peak discharge and total volume of debris flows are crucial for designing effective countermeasures in many populated mountain areas where losses of lives and property damage could be avoided. This study quantifies the relationship between flow depth, acoustic amplitude of debris flow induced ground vibrations and front velocity in the experimental catchment of Acquabona, Eastern Dolomites, Italy. The analysis of data brought about the results described in the following. Debris flow depth and amplitude of the flow-induced ground vibrations show a good positive correlation. Estimation of both mean front velocity and peak discharge can be simply obtained monitoring the ground vibrations, through geophones installed close to the flow channel; the total volume of debris flow can be so directly estimated from the integral of the ground vibrations using a regression line. The application of acoustic technique to debris flow monitoring seems to be of the outmost relevance in risk reduction policies and in the correct management of the territory. Moreover this estimation is possible in other catchments producing debris flows of similar characteristics by means of their acoustic characterisation through quick and simple field tests (Standard Penetration Tests and seismic refraction surveys).

  16. Acoustic Signal Processing

    Science.gov (United States)

    Hartmann, William M.; Candy, James V.

    Signal processing refers to the acquisition, storage, display, and generation of signals - also to the extraction of information from signals and the re-encoding of information. As such, signal processing in some form is an essential element in the practice of all aspects of acoustics. Signal processing algorithms enable acousticians to separate signals from noise, to perform automatic speech recognition, or to compress information for more efficient storage or transmission. Signal processing concepts are the building blocks used to construct models of speech and hearing. Now, in the 21st century, all signal processing is effectively digital signal processing. Widespread access to high-speed processing, massive memory, and inexpensive software make signal processing procedures of enormous sophistication and power available to anyone who wants to use them. Because advanced signal processing is now accessible to everybody, there is a need for primers that introduce basic mathematical concepts that underlie the digital algorithms. The present handbook chapter is intended to serve such a purpose.

  17. Acoustics of the Intonarumori

    Science.gov (United States)

    Serafin, Stefania

    2005-04-01

    The Intonarumori were a family of musical instruments invented by the Italian futurist composer and painter Luigi Russolo. Each Intonarumori was made of a wooden parallelepiped sound box, inside which a wheel of different sizes and materials was setting into vibration a catgut or metal string. The pitch of the string was varied by using a lever, while the speed of the wheel was controlled by the performer using a crank. At one end of the string there was a drumhead that transmitted vibrations to the speaker. Unfortunately, all the original Intonarumori were destroyed after a fire during World War II. Since then, researchers have tried to understand the sound production mechanism of such instruments, especially by consulting the patents compiled by Russolo or by reading his book ``The art of noise.'' In this paper we describe the acoustics of the Intonarumori. Based on such description, we propose physical models that simulate such instruments. The intonarumori's string is modeled using a one dimensional waveguide, which is excited either by an impact or a friction model. The body of the instrument is modeled using a 3-D rectangular mesh, while the horn is considered as an omnidirectional radiator.

  18. Software safety analysis practice in installation phase

    Energy Technology Data Exchange (ETDEWEB)

    Huang, H. W.; Chen, M. H.; Shyu, S. S., E-mail: hwhwang@iner.gov.t [Institute of Nuclear Energy Research, No. 1000 Wenhua Road, Chiaan Village, Longtan Township, 32546 Taoyuan County, Taiwan (China)

    2010-10-15

    This work performed a software safety analysis in the installation phase of the Lung men nuclear power plant in Taiwan, under the cooperation of Institute of Nuclear Energy Research and Tpc. The US Nuclear Regulatory Commission requests licensee to perform software safety analysis and software verification and validation in each phase of software development life cycle with Branch Technical Position 7-14. In this work, 37 safety grade digital instrumentation and control systems were analyzed by failure mode and effects analysis, which is suggested by IEEE standard 7-4.3.2-2003. During the installation phase, skew tests for safety grade network and point to point tests were performed. The failure mode and effects analysis showed all the single failure modes can be resolved by the redundant means. Most of the common mode failures can be resolved by operator manual actions. (Author)

  19. Idaho National Engineering Laboratory installation roadmap document

    International Nuclear Information System (INIS)

    The roadmapping process was initiated by the US Department of Energy's office of Environmental Restoration and Waste Management (EM) to improve its Five-Year Plan and budget allocation process. Roadmap documents will provide the technical baseline for this planning process and help EM develop more effective strategies and program plans for achieving its long-term goals. This document is a composite of roadmap assumptions and issues developed for the Idaho National Engineering Laboratory (INEL) by US Department of Energy Idaho Field Office and subcontractor personnel. The installation roadmap discusses activities, issues, and installation commitments that affect waste management and environmental restoration activities at the INEL. The High-Level Waste, Land Disposal Restriction, and Environmental Restoration Roadmaps are also included

  20. CosmoMC Installation and Running Guidelines

    CERN Document Server

    Li, Ming-Hua

    2014-01-01

    CosmoMC is a Fortran 95 Markov-Chain Monte-Carlo (MCMC) engine to explore the cosmological parameter space, plus a Python suite for plotting and presenting results (see http://cosmologist.info/cosmomc/). This document describes the installation of the CosmoMC on a Linux system (Ubuntu 14.04.1 LTS 64-bit version). It is written for those who want to use it in their scientific research but without much training on Linux and the program. Besides a step-by-step installation guide, we also give a brief introduction of how to run the program on both a desktop and a cluster. We share our way to generate the plots that are commonly used in the references of cosmology. For more information, one can refer to the CosmoCoffee forum (http://cosmocoffee.info/viewforum.php?f=11) or contact the authors of this document. Questions and comments would be much appreciated.

  1. Designing Software-Based Interactive Installations

    DEFF Research Database (Denmark)

    Andreasen, Troels; Juul, Niels Christian; Rosendahl, Mads

    2014-01-01

    considers the development of interactive installations for immersive experiences with emphasis on the special design challenges they present. How. The approach described includes four phases: exploration, design, construction, and exhibition. The aim of the exploration is to clarify the general behavior...... architecture as well as esthetic experience, artistic expression, and leisure aspects into focus. The approach presented here has this intended purpose. Where. Building on experience from conventional software development and with inspiration from interaction design and creative programming, this chapter...... of the installation using tools like sketching or storyboarding. The design involves a clarification of available and appropriate building blocks, as well as the linking of these blocks to provide an architectural framework comprising the intended external behavior. The construction phase takes a component...

  2. TMS installation at A-1 Test Stand

    Science.gov (United States)

    2010-01-01

    Employees at NASA's John C. Stennis Space Center complete installation of the new thrust measurement system on the A-1 Test Stand. The new TMS is a state-of-the-art upgrade from the previous system, which was installed when the testing structure was built in the 1960s. It is an advanced calibration system capable of measuring vertical and horizontal thrust loads with accuracy within 0.15 percent at 225,000 pounds. It also will allow engineers to measure thrust as they gimbal (or tilt) engines during tests. The new TMS is part of upgrades for the A-1 Test Stand in preparation for testing the next generation of American space program rocket engines.

  3. Focusing of Acoustic Waves through Acoustic Materials with Subwavelength Structures

    KAUST Repository

    Xiao, Bingmu

    2013-05-01

    In this thesis, wave propagation through acoustic materials with subwavelength slits structures is studied. Guided by the findings, acoustic wave focusing is achieved with a specific material design. By using a parameter retrieving method, an effective medium theory for a slab with periodic subwavelength cut-through slits is successfully derived. The theory is based on eigenfunction solutions to the acoustic wave equation. Numerical simulations are implemented by the finite-difference time-domain (FDTD) method for the two-dimensional acoustic wave equation. The theory provides the effective impedance and refractive index functions for the equivalent medium, which can reproduce the transmission and reflection spectral responses of the original structure. I analytically and numerically investigate both the validity and limitations of the theory, and the influences of material and geometry on the effective spectral responses are studied. Results show that large contrasts in impedance and density are conditions that validate the effective medium theory, and this approximation displays a better accuracy for a thick slab with narrow slits in it. Based on the effective medium theory developed, a design of a at slab with a snake shaped" subwavelength structure is proposed as a means of achieving acoustic focusing. The property of focusing is demonstrated by FDTD simulations. Good agreement is observed between the proposed structure and the equivalent lens pre- dicted by the theory, which leads to robust broadband focusing by a thin at slab.

  4. Solar heating system installed at Stamford, Connecticut

    Science.gov (United States)

    1979-01-01

    The solar heating system installed at the Lutz-Sotire Partnership Executive East Office Building, Stamford, Connecticut is described. The Executive East Office Building is of moderate size with 25,000 sq ft of heated space in 2 1/2 stories. The solar system was designed to provide approximately 50 percent of the heating requirements. The system components are described. Appended data includes: the system design acceptance test, the operation and maintenance manual, and as-built drawings and photographs.

  5. Installation of a Roof Mounted Photovoltaic System

    Science.gov (United States)

    Lam, M.

    2015-12-01

    In order to create a safe and comfortable environment for students to learn, a lot of electricity, which is generated from coal fired power plants, is used. Therefore, ISF Academy, a school in Hong Kong with approximately 1,500 students, will be installing a rooftop photovoltaic (PV) system with 302 solar panels. Not only will these panels be used to power a classroom, they will also serve as an educational opportunity for students to learn about the importance of renewable energy technology and its uses. There were four different options for the installation of the solar panels, and the final choice was made based on the loading capacity of the roof, considering the fact that overstressing the roof could prove to be a safety hazard. Moreover, due to consideration of the risk of typhoons in Hong Kong, the solar panel PV system will include concrete plinths as counterweights - but not so much that the roof would be severely overstressed. During and after the installation of the PV system, students involved would be able to do multiple calculations, such as determining the reduction of the school's carbon footprint. This can allow students to learn about the impact renewable energy can have on the environment. Another project students can participate in includes measuring the efficiency of the solar panels and how much power can be produced per year, which in turn can help with calculate the amount of money saved per year and when we will achieve economic parity. In short, the installation of the roof mounted PV system will not only be able to help save money for the school but also provide learning opportunities for students studying at the ISF Academy.

  6. Reconciling interiors: The screen as installation

    OpenAIRE

    Charlton, James

    2003-01-01

    In examining the failure of contemporary art to understand the relationship between the screen and the sculptural context in which it is seen,this paper critiques current notions of the screen and compares them to the spatial modalities of installation art. Firstly identifying the screen as a product of parts ? the apparatus,the image and the space ? the essay draws together arguments presented by artists and theorists and exposes the strategies and assumptions that enable the viewer to e...

  7. MICROCOSM - INSTALLATION OF THE LHC MODEL

    CERN Multimedia

    2002-01-01

    This week, installation of a 6m long section of the LHC starts in Microcosm. This full-scale model is the first part of a new exhibition highlighting the technological challenges and the exciting physics of the LHC era. Many people at CERN have helped with the preparations for the model and the Microcosm team would like to thank all those involved. An inauguration for the press will take place at the start of the next school term.

  8. CASTOR Calorimeter Installation Review at CMS

    CERN Multimedia

    CERN Video Productions

    2011-01-01

    This test is a part of CASTOR EDR process. The CASTOR phys-tech review held on 14 Jan 2011 and the subsequent EDR held on 17 Jun 2011, the CMS Management Board has endorsed a strategy in which CASTOR is removed during the 2011 Year-End Technical Stop, but is then refurbished, replacing a substantial fraction of the phototubes, so that it is ready for re-installation in the Technical Stop just before 2012 heavy-ion operation.

  9. Installing paparazzi autopilot into a model airplane

    OpenAIRE

    Ojala, Allan

    2010-01-01

    This Bachelor degree study explores the open source Autopilot “Paparazzi” that was installed into a model airplane. The aim for this was to get the model airplane to fly short flight and study what difficulties there are in a project like this. The field of UAV research is innovative and number of companies selling ready UAV products is growing, also many education institutes and amateurs are making their own implementations of UAVs. Paparazzi autopilot is a complete system of hardware a...

  10. Brief description of the Wackersdorf reprocessing installation

    International Nuclear Information System (INIS)

    This description covers the site, the techniques and experiences in the processing of nuclear fuels, structure and function of the planned installation, safety provisions for the planned plant and control of accidents, the effects of the plant and its operation on the surrounding area, measures for the removal of the radioactive waste, and measures for the final shutdown of the plant. 37 figures, 8 tables

  11. Manual UT vs Permanently Installed Sensors

    OpenAIRE

    Cegla, Frederic

    2014-01-01

    Ultrasonic NDE and inspection techniques are often strongly influenced by procedures and human factors as well as the underlying physics of the measurement technique. Automation of some of the acquisition tasks potentially eliminates some sources of error. The NDE group at Imperial College London has developed permanently installed ultrasonic thickness monitoring tools which allow frequent acquisition as well as automatic evaluation of ultrasonic wall thickness estimates. Several thousand sen...

  12. Installation of reactor vessel support ring

    International Nuclear Information System (INIS)

    Installation activities of reactor vessel support ring for Unit 1 and Unit 2 of Daya Bay Nuclear Power Plant were presented, including prerequisites, handling, assembling, positioning, second-stage concreting, inspection and documentation. In particular, the processing of non-conformances for Unit 1 as experience feedback leading to the design modification which has been applied in the support ring assembling activities for Unit 2 was introduced. (9 figs, 1 tab.)

  13. Low background techniques for the Borexino nylon vessels

    CERN Document Server

    Pocar, A

    2005-01-01

    Borexino is an organic liquid scintillator underground detector for low energy solar neutrinos. The experiment has to satisfy extremely stringent low background requirements. The thin nylon spherical scintillator containment vessel has to meet cleanliness and low radioactivity levels second only, within the detector, to the scintillator itself. Overall, the background from the vessel in the fiducial volume of the detector must be kept at the level of one event per day or better. The requirements, design choices, results from laboratory tests, and fabrication techniques that have been adopted to meet this goal are presented. Details of the precautions taken during the installation of the vessels inside the Borexino detector are also discussed.

  14. Reactor cavity cleanup system shielded filter installation

    International Nuclear Information System (INIS)

    The Seabrook Station reactor cavity cleanup system provides a flow path for refueling pool purification and drain down during plant refueling evolutions. The original system design included refueling pool surface skimmers and drains, a skimmer pump, an unshielded duplex basket type pump suction strainer and interconnecting stainless steel piping. The piping design utilized socket welded joints in small bore pipe with diaphragm values installed in the horizontal pipe runs downstream of the skimmer pump. The previously installed unshielded strainer in addition to the skimmer pump downstream piping components were determined to be inconsistent with Seabrook's proactive approach to dose reduction. To be consistent with ALARA (As Low As Reasonably Achievable) policy, a plant design change was authorized to install a lead shielded filter unit as a replacement for the existing duplex strainer. This filter unit, which utilizes multiple micron rating disposable basket type cartridges, has a threefold function of protecting the skimmer pump from large solids, providing bulk filtration of activated corrosion products from the refueling water in order to minimize CRUD buildup in downstream components, and enabling retrieval of foreign material drawn into the refueling pool drains

  15. AWAKE starts the equipment installation phase

    CERN Multimedia

    Antonella Del Rosso

    2015-01-01

    AWAKE is the proof-of-principle experiment whose aim is to use protons to generate powerful wakefields to accelerate an electron beam. With accelerator gradients hundreds of times higher than those used in current systems, this technique could revolutionise the field of particle acceleration. Installed in the tunnel previously used by the CNGS facility, AWAKE is completing the service installation phase and will receive the plasma cell in the coming months.   The AWAKE proton line with all the magnets installed. (Image: AWAKE collaboration.) AWAKE is the world’s first proton-driven plasma wakefield acceleration experiment. In AWAKE, a beam of protons from the SPS will be travelling through a plasma cell and this will generate a wakefield that, in turn, will accelerate an electron beam. A laser will ionise the gas in the plasma cell and seed the self-modulation instability that will trigger the wakefield in the plasma. The project aims to prove that the plasma wakefield can be driv...

  16. Design of the Los Alamos generator installation

    International Nuclear Information System (INIS)

    A 1430 MVA synchronous generator from a cancelled nuclear power plant is being installed at Los Alamos to be used as the pulsed power generator for the Confinement Physics Research Facility. The generator is mounted on a spring foundation to avoid dynamic forces from being transmitted to the substructure and the ground. A 6 MW load-commutated inverter drive will accelerate the machine from standstill to the maximum operating speed of 1800 rpm and from 1260 rpm to 1800 rpm between load pulses. The generator cooling method is being changed from hydrogen to air cooling. A current limiting fuse, with a fuse clearing current of 80 kA, will protect the generator output against short circuit currents. Changes in the excitation system are described. A status report of the installation and an approximate schedule for completing the installation are presented. The paper also addresses results of special studies and tests undertaken to evaluate the condition of the generator and to predict the behavior of some critical mechanical generator components under pulsed loading conditions. 1 ref., 4 figs., 2 tabs

  17. Water discharging over weir with installed boom

    Directory of Open Access Journals (Sweden)

    Kupriyanov Vladimir Pavlovich

    2014-03-01

    Full Text Available This paper considers a possibility of booms application at spillway dams in order to reduce gates size and capacity of weight lifting device without changing weir discharge capacity. The prospects of booms application at weir top were proved during hydraulic researches conducted at JSC “NIIES” (Joint Stock Company “Scientific Research Institute of Energy Structures”. Basing on the conducted researches the recommendations of booms application at spillway facilities of Yumaguzinskaya and Upper Krasnogorskaya hydropower schemes, as well as at spillway facilities of Sayano-Shushenskaya and Plyavinskaya hydropower plants have been worked out. The main factor limiting wide application of booms at weirs is lack of feasible data for designing. At first, this data has to conclude methods of defining spillway discharge capacity and elevation of boom installation, which allows to keep the same spillway discharge capacity at rated head. The equations to define optimal elevation of boom installation and weir discharge capacity without its submergence have been analytically obtained for nappe-crested weir with installed boom. At the present time it is needed to conduct methodical experimental studies to define the discharge ratio and vertical compression according to different types of booms.

  18. Characterization Of Station Quality From The CHILE RAMP Deployment - Direct Burial Sensor Installation And Its Data

    Science.gov (United States)

    Arias, E. Y.; Beaudoin, B. C.; Barstow, N.; Slad, G.

    2010-12-01

    IRIS PASSCAL supported a NSF-funded project to collect an open community dataset from a portable seismograph deployment following the magnitude 8.8 earthquake that occurred off the coast of Chile on February 27, 2010 (an experiment of the Rapid Array Mobilization Program - RAMP). In part, due to logistical constraints, the broadband sensors (Guralp CMG3T) for this deployment were buried directly in soil. Direct burial refers to installation of a broadband sensor in a small hand-dug hole, encased in plastic bags, and ideally backfilled with well tamped and dampened sand. Field conditions did not provide ideal installations in all cases. Because of the variability in actual installation practices, the Chile RAMP data provide an opportunity to examine the impact of several factors on the direct burial data quality. Using McNamara and Boaz (2005) PQLX statistical analysis software, which calculates the power spectral density (PSD) and plots the probability density function (PDF)(McNamara and Buland, 2004), we characterize the background seismic noise levels and signal quality for 58 directly buried installations at the Chile RAMP. Data return and data quality during the deployment (April -September 2010) will be evaluated considering a variety of parameters including installation technique, site characteristics, and equipment performance. Preliminary results using data from two service runs (April - June), suggest variation in the data quality and recovery due to slightly different installation practices and/or possibly environmental factors. We seek to evaluate and characterize parameters that affect the resulting data recovery and their quality; this study is an important test case for future PASSCAL and RAMP installations. If possible we would like to compare data from other local networks to identify distinctive characteristics from different installation set-ups.

  19. Experience in installing a microprocessor-based protection system on a UK nuclear power plant

    International Nuclear Information System (INIS)

    This paper describes a recently completed project to install a microprocessor-based reactor protection system on a twin reactor station in the United Kingdom. This represented the first application of digital technology as part of such a system in the UK. The background of the application and details of the chosen solution are provided. The experience gained during the installation, commissioning and early operation of the equipment is reviewed by the operators. Interactions between the utility and the regulatory body are outlined and the impact of the regulatory process on the utility's resources and the project timescales are discussed

  20. Installation for producing sealed radioactive sources; Installation de fabrication de sources radioactives scellees

    Energy Technology Data Exchange (ETDEWEB)

    Fradin, J.; Hayoun, C. [Commissariat a l' Energie Atomique, 91 - Saclay (France). Centre d' Etudes Nucleaires

    1969-07-01

    This installation has been designed and built for producing sealed sources of fission elements: caesium 137, strontium 90, promethium 147, ruthenium 106 and cerium 144 in particular. The installation consists of sealed and protected cells, each being assigned to a particular production. The safety and the operational reliability of the equipment are the principal considerations which have governed this work. The report describes the installation and, in particular, the apparatus used as well as the various control devices. In conclusion, a review as presented of six years operation. (authors) [French] Cette installation a ete concue et realisee pour effectuer des fabrications de sources scellees d'elements de fission: caesium 137 - strontium 90 - promethium 147 - ruthenium 106 - cerium 144 en particulier. L'installation est composee de cellules etanches et protegees, chacune d'elles etant affectee a une fabrication particuliere. La securite et la surete de fonctionnement de l'ensemble sont parmi les elements principaux qui ont guide l'etude. Le rapport decrit l'installation et plus particulierement l'appareillage utilise ainsi que les divers controles et commandes. Le bilan de fonctionnement apres 6 ans d'exploitation sert de conclusion. (auteurs)

  1. Acoustic communication in plant-animal interactions.

    Science.gov (United States)

    Schöner, Michael G; Simon, Ralph; Schöner, Caroline R

    2016-08-01

    Acoustic communication is widespread and well-studied in animals but has been neglected in other organisms such as plants. However, there is growing evidence for acoustic communication in plant-animal interactions. While knowledge about active acoustic signalling in plants (i.e. active sound production) is still in its infancy, research on passive acoustic signalling (i.e. reflection of animal sounds) revealed that bat-dependent plants have adapted to the bats' echolocation systems by providing acoustic reflectors to attract their animal partners. Understanding the proximate mechanisms and ultimate causes of acoustic communication will shed light on an underestimated dimension of information transfer between plants and animals. PMID:27423052

  2. Modelling of acoustic transmission through perforated layer

    Directory of Open Access Journals (Sweden)

    Lukeš V.

    2007-10-01

    Full Text Available The paper deals with modeling the acoustic transmission through a perforated interface plane separating two halfspaces occupied by the acoustic medium. We considered the two-scale homogenization limit of the standard acoustic problem imposed in the layer with the perforated periodic structure embedded inside. The homogenized transmission conditions govern the interface discontinuity of the acoustic pressure associated with the two halfspaces and the magnitude of the fictitious transversal acoustic velocity. By numerical examples we illustrate this novel approach of modeling the acoustic impedance of perforated interfaces.

  3. Geodesic Acoustic Modes Induced by Energetic Particles

    Science.gov (United States)

    Zhou, Tianchun; Berk, Herbert

    2009-11-01

    A global geodesic acoustic mode driven by energetic particles (EGAM) has been observed in JET[1, 2] and DIII D[3, 4]. The mode is to be treated fully kinetically. The descriptions of the background electrons and ions are based on standard high and low bounce frequency expansion respectively with respect to the mode frequency. However, the energetic ions must be treated without any expansion of ratio between their bounce frequency and the mode frequency since they are comparable. Under electrostatic perturbation, we construct a quadratic form for the wave amplitude, from which an integro-differential equation is derived. In the limit where the drift orbit width is small comparison with the mode width, a differential equation for perturbed electrostatic field is obtained. Solution is obtained both analytically and numerically. We find that beam counterinjection enhances the instability of the mode. Landau damping due to thermal species is investigated.

  4. Background sounds contribute to spectrotemporal plasticity in primary auditory cortex.

    Science.gov (United States)

    Moucha, Raluca; Pandya, Pritesh K; Engineer, Navzer D; Rathbun, Daniel L; Kilgard, Michael P

    2005-05-01

    The mammalian auditory system evolved to extract meaningful information from complex acoustic environments. Spectrotemporal selectivity of auditory neurons provides a potential mechanism to represent natural sounds. Experience-dependent plasticity mechanisms can remodel the spectrotemporal selectivity of neurons in primary auditory cortex (A1). Electrical stimulation of the cholinergic nucleus basalis (NB) enables plasticity in A1 that parallels natural learning and is specific to acoustic features associated with NB activity. In this study, we used NB stimulation to explore how cortical networks reorganize after experience with frequency-modulated (FM) sweeps, and how background stimuli contribute to spectrotemporal plasticity in rat auditory cortex. Pairing an 8-4 kHz FM sweep with NB stimulation 300 times per day for 20 days decreased tone thresholds, frequency selectivity, and response latency of A1 neurons in the region of the tonotopic map activated by the sound. In an attempt to modify neuronal response properties across all of A1 the same NB activation was paired in a second group of rats with five downward FM sweeps, each spanning a different octave. No changes in FM selectivity or receptive field (RF) structure were observed when the neural activation was distributed across the cortical surface. However, the addition of unpaired background sweeps of different rates or direction was sufficient to alter RF characteristics across the tonotopic map in a third group of rats. These results extend earlier observations that cortical neurons can develop stimulus specific plasticity and indicate that background conditions can strongly influence cortical plasticity.

  5. Acoustic Emission Analysis of Prestressed Concrete Structures

    Energy Technology Data Exchange (ETDEWEB)

    Elfergani, H A; Pullin, R; Holford, K M, E-mail: ElferganiH@Cardiff.ac.uk, E-mail: PullinR@cardiff.ac.uk, E-mail: holford@Cardiff.ac.uk [Cardiff School of Engineering, Cardiff University, Queen' s Building, The Parade, Cardiff, CF24 3AA, Wales (United Kingdom)

    2011-07-19

    Corrosion is a substantial problem in numerous structures and in particular corrosion is very serious in reinforced and prestressed concrete and must, in certain applications, be given special consideration because failure may result in loss of life and high financial cost. Furthermore corrosion cannot only be considered a long term problem with many studies reporting failure of bridges and concrete pipes due to corrosion within a short period after they were constructed. The concrete pipes which transport water are examples of structures that have suffered from corrosion; for example, the pipes of The Great Man-Made River Project of Libya. Five pipe failures due to corrosion have occurred since their installation. The main reason for the damage is corrosion of prestressed wires in the pipes due to the attack of chloride ions from the surrounding soil. Detection of the corrosion in initial stages has been very important to avoid other failures and the interruption of water flow. Even though most non-destructive methods which are used in the project are able to detect wire breaks, they cannot detect the presence of corrosion. Hence in areas where no excavation has been completed, areas of serious damage can go undetected. Therefore, the major problem which faces engineers is to find the best way to detect the corrosion and prevent the pipes from deteriorating. This paper reports on the use of the Acoustic Emission (AE) technique to detect the early stages of corrosion prior to deterioration of concrete structures.

  6. Acoustic Emission Analysis of Prestressed Concrete Structures

    Science.gov (United States)

    Elfergani, H. A.; Pullin, R.; Holford, K. M.

    2011-07-01

    Corrosion is a substantial problem in numerous structures and in particular corrosion is very serious in reinforced and prestressed concrete and must, in certain applications, be given special consideration because failure may result in loss of life and high financial cost. Furthermore corrosion cannot only be considered a long term problem with many studies reporting failure of bridges and concrete pipes due to corrosion within a short period after they were constructed. The concrete pipes which transport water are examples of structures that have suffered from corrosion; for example, the pipes of The Great Man-Made River Project of Libya. Five pipe failures due to corrosion have occurred since their installation. The main reason for the damage is corrosion of prestressed wires in the pipes due to the attack of chloride ions from the surrounding soil. Detection of the corrosion in initial stages has been very important to avoid other failures and the interruption of water flow. Even though most non-destructive methods which are used in the project are able to detect wire breaks, they cannot detect the presence of corrosion. Hence in areas where no excavation has been completed, areas of serious damage can go undetected. Therefore, the major problem which faces engineers is to find the best way to detect the corrosion and prevent the pipes from deteriorating. This paper reports on the use of the Acoustic Emission (AE) technique to detect the early stages of corrosion prior to deterioration of concrete structures.

  7. Acoustic noise associated with the MOD-1 wind turbine: its source, impact, and control

    Energy Technology Data Exchange (ETDEWEB)

    Kelley, N.D.; McKenna, H.E.; Hemphill, R.R.; Etter, C.L.; Garrelts, R.L.; Linn, N.C.

    1985-02-01

    This report summarizes extensive research by staff of the Solar Energy Research Institute and its subcontractors conducted to establish the origin and possible amelioration of acoustic disturbances associated with the operation of the DOE/NASA MOD-1 wind turbine installed in 1979 near Boone, North Carolina. Results have shown that the source of this acoustic annoyance was the transient, unsteady aerodynamic lift imparted to the turbine blades as they passed through the lee wakes of the large, cylindrical tower supports. Nearby residents were annoyed by the low-frequency, acoustic impulses propagated into the structures in which the complainants lived. The situation was aggravated further by a complex sound propagation process controlled by terrain and atmospheric focusing. Several techniques for reducing the abrupt, unsteady blade load transients were researched and are discussed in the report.

  8. The case for background independence

    CERN Document Server

    Smolin, L

    2005-01-01

    The aim of this paper is to explain carefully the arguments behind the assertion that the correct quantum theory of gravity must be background independent. We begin by recounting how the debate over whether quantum gravity must be background independent is a continuation of a long-standing argument in the history of physics and philosophy over whether space and time are relational or absolute. This leads to a careful statement of what physicists mean when we speak of background independence. Given this we can characterize the precise sense in which general relativity is a background independent theory. The leading background independent approaches to quantum gravity are then discussed, including causal set models, loop quantum gravity and dynamical triangulations and their main achievements are summarized along with the problems that remain open. Some first attempts to cast string/M theory into a background independent formulation are also mentioned. The relational/absolute debate has implications also for ot...

  9. Testing coupled dark energy models with their cosmological background evolution

    CERN Document Server

    van de Bruck, Carsten; Morrice, Jack

    2016-01-01

    We consider a cosmology in which dark matter and a quintessence scalar field responsible for the acceleration of the Universe are allowed to interact. Allowing for both conformal and disformal couplings, we perform a global analysis of the constraints on our model using Hubble parameter measurements, baryon acoustic oscillation distance measurements, and a Supernovae Type Ia data set. We find that the additional disformal coupling relaxes the conformal coupling constraints. Moreover we show that, at the background level, a disformal interaction within the dark sector is preferred to both $\\Lambda$CDM and uncoupled quintessence, hence favouring interacting dark energy.

  10. Sonification of acoustic emission data

    Science.gov (United States)

    Raith, Manuel; Große, Christian

    2014-05-01

    While loading different specimens, acoustic emissions appear due to micro crack formation or friction of already existing crack edges. These acoustic emissions can be recorded using suitable ultrasonic transducers and transient recorders. The analysis of acoustic emissions can be used to investigate the mechanical behavior of different specimens under load. Our working group has undertaken several experiments, monitored with acoustic emission techniques. Different materials such as natural stone, concrete, wood, steel, carbon composites and bone were investigated. Also the experimental setup has been varied. Fire-spalling experiments on ultrahigh performance concrete and pullout experiments on bonded anchors have been carried out. Furthermore uniaxial compression tests on natural stone and animal bone had been conducted. The analysis tools include not only the counting of events but the analysis of full waveforms. Powerful localization algorithms and automatic onset picking techniques (based on Akaikes Information Criterion) were established to handle the huge amount of data. Up to several thousand events were recorded during experiments of a few minutes. More sophisticated techniques like moment tensor inversion have been established on this relatively small scale as well. Problems are related to the amount of data but also to signal-to-noise quality, boundary conditions (reflections) sensor characteristics and unknown and changing Greens functions of the media. Some of the acoustic emissions recorded during these experiments had been transferred into audio range. The transformation into the audio range was done using Matlab. It is the aim of the sonification to establish a tool that is on one hand able to help controlling the experiment in-situ and probably adjust the load parameters according to the number and intensity of the acoustic emissions. On the other hand sonification can help to improve the understanding of acoustic emission techniques for training

  11. Acoustic constituents of prosodic typology

    Science.gov (United States)

    Komatsu, Masahiko

    Different languages sound different, and considerable part of it derives from the typological difference of prosody. Although such difference is often referred to as lexical accent types (stress accent, pitch accent, and tone; e.g. English, Japanese, and Chinese respectively) and rhythm types (stress-, syllable-, and mora-timed rhythms; e.g. English, Spanish, and Japanese respectively), it is unclear whether these types are determined in terms of acoustic properties, The thesis intends to provide a potential basis for the description of prosody in terms of acoustics. It argues for the hypothesis that the source component of the source-filter model (acoustic features) approximately corresponds to prosody (linguistic features) through several experimental-phonetic studies. The study consists of four parts. (1) Preliminary experiment: Perceptual language identification tests were performed using English and Japanese speech samples whose frequency spectral information (i.e. non-source component) is heavily reduced. The results indicated that humans can discriminate languages with such signals. (2) Discussion on the linguistic information that the source component contains: This part constitutes the foundation of the argument of the thesis. Perception tests of consonants with the source signal indicated that the source component carries the information on broad categories of phonemes that contributes to the creation of rhythm. (3) Acoustic analysis: The speech samples of Chinese, English, Japanese, and Spanish, differing in prosodic types, were analyzed. These languages showed difference in acoustic characteristics of the source component. (4) Perceptual experiment: A language identification test for the above four languages was performed using the source signal with its acoustic features parameterized. It revealed that humans can discriminate prosodic types solely with the source features and that the discrimination is easier as acoustic information increases. The

  12. Acoustic method for investigation of the structural defects in metals

    International Nuclear Information System (INIS)

    In this work an acoustic method is presented called, the resonant bar method, which is based on the interaction between ultrasound and the structural defects in high purity metals. By this method the internal dislocation friction (Q-1) and the propagation velocity (v) of the ultrasound in the bar is measured. Both quantities are shown to depend on the dislocation densities and the length of dislocation loop. The experimental setup is shown. It consists of the resonant bar, the excitation spool, a generator of variable frequency and amplitude, a receptor spool, a selective amplifier and the adjacent measuring and displaying apparatus. The two spools are located inside of a toroidal permanent magnet. The bar oscillations are produced by the variable electromagnetic force appearing between the whirl current induced in the sample by the generator and the field of toroidal magnet. This method is applied to nonmagnetic materials with high electric conductivity. If the bar under study consists of a insulating material then on its ends either a conducting thin layer or a metallic thin sheet is deposed. The installation allows measuring the acoustic parameters of materials (v and Q-1) by two procedures, the method of free damped oscillations and the method of forced oscillations. Also, the internal friction can be measured with this installation, either dependent on or independent of the generator amplitude. Measurements on aluminium samples resulted in the following values: Q-1(3 ppm) = 10-3 and Q-1(150 ppm) = 10-5. By means of this installation internal friction can be studied in re-baked, annealed, mechanical deformed and irradiated samples or in materials submitted to other processes

  13. Background subtraction theory and practice

    CERN Document Server

    Elgammal, Ahmed

    2014-01-01

    Background subtraction is a widely used concept for detection of moving objects in videos. In the last two decades there has been a lot of development in designing algorithms for background subtraction, as well as wide use of these algorithms in various important applications, such as visual surveillance, sports video analysis, motion capture, etc. Various statistical approaches have been proposed to model scene backgrounds. The concept of background subtraction also has been extended to detect objects from videos captured from moving cameras. This book reviews the concept and practice of back

  14. My 65 years in acoustics

    Science.gov (United States)

    Beranek, Leo L.

    2001-05-01

    My entry into acoustics began as research assistant to Professor F. V. Hunt at Harvard University. I received my doctorate in 1940 and directed the Electro-Acoustic Laboratory at Harvard from October 1940 until September 1945. In 1947, I became a tenured associate professor at MIT, and, with Richard H. Bolt, formed the consulting firm Bolt and Beranek, that later included Robert B. Newman, becoming BBN. My most significant contributions before 1970 were design of wedge-lined anechoic chambers, systemization of noise reduction in ventilation systems, design of the world's largest muffler for the testing of supersonic jet engines at NASA's Lewis Laboratory in Cleveland, speech interference level, NC noise criterion curves, heading New York Port Authority's noise study that resulted in mufflers on jet aircraft, and steep aircraft climb procedures, and publishing books titled, Acoustical Measurements, Acoustics, Noise Reduction, Noise and Vibration Control, and Music, Acoustics and Architecture. As President of BBN, I supervised the formation of the group that built and operated the ARPANET (1969), which, when split in two (using TCP/IP protocol) became the INTERNET (1984). Since then, I have written two books on Concert Halls and Opera Houses and have consulted on four concert halls and an opera house.

  15. Sperm whale assessment in the Western Ionian Sea using acoustic data from deep sea observatories

    Science.gov (United States)

    Caruso, Francesco; Bellia, Giorgio; Beranzoli, Laura; De Domenico, Emilio; Larosa, Giuseppina; Marinaro, Giuditta; Papale, Elena; Pavan, Gianni; Pellegrino, Carmelo; Pulvirenti, Sara; Riccobene, Giorgio; Scandura, Danila; Sciacca, Virginia; Viola, Salvatore

    2015-04-01

    The Italian National Institute of Nuclear Physics (INFN) operates two deep sea infrastructures: Capo Passero, Western Ionian Sea 3,600 meters of depth, and Catania Wester Ionian Sea 2,100 m depth. At the two sites, several research observatories have been run: OnDE, NEMO-SN1, SMO, KM3NeT-Italia most of them jointly operated between INFN and INGV. In all these observatories, passive acoustic sensors (hydrophones) have been installed. Passive Acoustics Monitoring (PAM) is nowadays the main tool of the bioacoustics to study marine mammals. In particular, receiving the sounds emitted by cetaceans from a multi-hydrophones array installed in a cabled seafloor observatory, a research about the ecological dynamics of the species may be performed. Data acquired with the hydrophones installed aboard the OnDE, SMO and KM3NeT-Italia observatories will be reported. Thanks to acquired data, the acoustic presence of the sperm whales was assessed and studied for several years (2005:2013). An "ad hoc" algorithm was also developed to allow the automatic identification of the "clicks" emitted by the sperm whales and measure the size of detected animals. According to the results obtained, the sperm whale population in the area is well-distributed in size, sex and sexual maturity. Although specimens more than 14 meters of length (old males) seem to be absent.

  16. Retromastoid-sub occipital: A novel approach to cerebello pontine angle in acoustic neuroma surgery-our experience in 21 cases

    OpenAIRE

    Nayak, P. K.; RVS Kumar

    2011-01-01

    Background: Acoustic neuroma surgery poses significant challenges regarding definite management and preservation of hearing and the facial nerve are of great concern. Aim: To analyze the efficacy of the retromastoid approach in acoustic neuroma surgery. Materials and Methods: Tumors operated between January 2002 and December 2008, by the authors, using the retromastoid approach, were analyzed. Twenty-one patients who presented with acoustic tumor were considered for this study. Discussion: Pr...

  17. Acoustic detection of ultra-high energy cascades in ice

    Energy Technology Data Exchange (ETDEWEB)

    Boeser, S.

    2006-12-08

    Current underwater optical neutrino telescopes are designed to detect neutrinos from astrophysical sources with energies in the TeV range. Due to the low fluxes and small cross sections, no high energy neutrinos of extraterrestrial origin have been observed so far. Only the Cherenkov neutrino detectors on the km{sup 3} scale that are currently under construction will have the necessary volume to observe these rare interactions. For the guaranteed source of neutrinos from interactions of the ultra-high energy cosmic at EeV energies rays with the ambient cosmic microwave background, event rates of only one per year are expected in these experiments. To measure the flux and verify the predicted cross sections of these cosmogenic neutrinos, an observed volume of the order of 100 km{sup 3} will be necessary, that will not be feasible with existing detection techniques. Alternative methods are required to build a detector on these scales. One promising idea is to record the acoustic waves generated in hadronic or electromagnetic cascades following the neutrino interaction. The higher amplitudes of the sonic signal and the large expected absorption length of sound favour South Polar ice instead of sea water as a medium. The prerequisites for an estimate of the potential of such a detector are suitable acoustic sensors, a verification of the model of thermo-acoustic sound generation and a determination of the acoustic properties of the ice. In a theoretical derivation the mechanism of thermo-elastic excitation of acoustic waves was shown to be equivalent for isotropic solids and liquids. Following a detailed analysis of the existing knowledge a simulation study of a hybrid optical-radio-acoustic detector has been performed. Ultrasonic sensors dedicated to in-ice application were developed and have been used to record acoustic signals from intense proton and laser beams in water and ice. With the obtained experience, the hitherto largest array of acoustic sensors and

  18. Acoustic detection of ultra-high energy cascades in ice

    International Nuclear Information System (INIS)

    Current underwater optical neutrino telescopes are designed to detect neutrinos from astrophysical sources with energies in the TeV range. Due to the low fluxes and small cross sections, no high energy neutrinos of extraterrestrial origin have been observed so far. Only the Cherenkov neutrino detectors on the km3 scale that are currently under construction will have the necessary volume to observe these rare interactions. For the guaranteed source of neutrinos from interactions of the ultra-high energy cosmic at EeV energies rays with the ambient cosmic microwave background, event rates of only one per year are expected in these experiments. To measure the flux and verify the predicted cross sections of these cosmogenic neutrinos, an observed volume of the order of 100 km3 will be necessary, that will not be feasible with existing detection techniques. Alternative methods are required to build a detector on these scales. One promising idea is to record the acoustic waves generated in hadronic or electromagnetic cascades following the neutrino interaction. The higher amplitudes of the sonic signal and the large expected absorption length of sound favour South Polar ice instead of sea water as a medium. The prerequisites for an estimate of the potential of such a detector are suitable acoustic sensors, a verification of the model of thermo-acoustic sound generation and a determination of the acoustic properties of the ice. In a theoretical derivation the mechanism of thermo-elastic excitation of acoustic waves was shown to be equivalent for isotropic solids and liquids. Following a detailed analysis of the existing knowledge a simulation study of a hybrid optical-radio-acoustic detector has been performed. Ultrasonic sensors dedicated to in-ice application were developed and have been used to record acoustic signals from intense proton and laser beams in water and ice. With the obtained experience, the hitherto largest array of acoustic sensors and transmitters was

  19. Gait instability in patients with small acoustic neuroma

    Institute of Scientific and Technical Information of China (English)

    WANG Yan; JIANG Hai-yang; GUAN Chao; JIANG Xue-jun; Ishikawa Kazuo; ZHOU Hong-wu

    2011-01-01

    Background Small acoustic neuromas seldom result in typical vestibular symptoms, despite the tumor arising from the vestibular nerve. In this study, we have shown that abnormal gait in eleven patients with small acoustic neuroma could be detected in gait analysis by the use of tactile sensor. Patients displayed no oculomotor abnormality and had tumors less than 10 mm from the porus acoustics.Methods Gait related parameters including the coefficients of variations (CV) of stance, swing, double support, area ratio of trajectories of center of force (TCOF), in addition to the foot pressure difference between both feet, were used for assessment of gait.Results The CV of swing and the area ratio of TCOF were greater in patients than those in the control group (P <0.05).The values of these two parameters became greater under an eyes closed condition compared to eyes open (P<0.05) in the patient group.Conclusion These results indicate that gait analysis may be helpful to assess vestibulospinal function of patients with small acoustic neuroma, the slight vestibular deficits of which can not be detected by visual observation.

  20. Use of acoustic monitoring system for debris flow discharge evaluation

    Science.gov (United States)

    Galgaro, A. G.; Tecca, P. R.; Genevois, R.; Deganutti, A. M.

    2003-04-01

    In 1997 an automated system for monitoring of debris flows has been installed in the Acquabona channel Dolomites, Italy. Induction geophones, with a specific frequency of 10 Hz, measure the amplitude of vertical ground vibrations generated by the passage of a flowing mass along the channel. Continuous acoustic logs and ultrasonic hydrograph recorded at the lower-channel measurement station for the debris flow of August 17, 1998, show a striking correspondence. This correspondence, already observed in different flow sites, is represented by the best fit between flow depth and flow sensor amplitude. Average front velocity for surges, calculated from the signal peak time shift and the distance between the sensors along the flow path, range between 2.00 and 7.7 m/s. As the ultrasonic sensor provides a way to measure the variation of the flow section area with the flow depth, the debris flow peak discharge may be estimated; obtained values of debris flow peak discharge range from 4 and 30 m3/s. Volumes were calculated by integrating instantaneous discharges through the hydrograph and by integrating the geophone log (acoustic flux). Volumes of 13700 m3 and 15500 m3 have been respectively obtained. The slight difference between the two values may result from the fact that acoustic records: i) are sensitive to the high frequencies, typical of the debris flow tails; ii) sum up the contributions sent by the whole flowing mass, while the ecometer detect the flow depth at every time at only one section. As a consequence the rising of the whole geophone log gives a higher value at the integration result. This only acoustic system can give a reasonably proxy for discharge and total volumes involved, which are among the most important parameters for debris flow hazard assessment and planning countermeasures. This methodology can be used in other debris flow sites if they are calibrated by the acoustic characterization of debris, obtained by both seismic surveys and SPT tests, and