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Sample records for rapid acoustic prediction

  1. 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...

  2. Predicting and auralizing acoustics in classrooms

    DEFF Research Database (Denmark)

    Christensen, Claus Lynge

    2005-01-01

    Although classrooms have fairly simple geometries, this type of room is known to cause problems when trying to predict their acoustics using room acoustics computer modeling. Some typical features from a room acoustics point of view are: Parallel walls, low ceilings (the rooms are flat), uneven...

  3. Energy based prediction models for building acoustics

    DEFF Research Database (Denmark)

    Brunskog, Jonas

    2012-01-01

    In order to reach robust and simplified yet accurate prediction models, energy based principle are commonly used in many fields of acoustics, especially in building acoustics. This includes simple energy flow models, the framework of statistical energy analysis (SEA) as well as more elaborated...... principles as, e.g., wave intensity analysis (WIA). The European standards for building acoustic predictions, the EN 12354 series, are based on energy flow and SEA principles. In the present paper, different energy based prediction models are discussed and critically reviewed. Special attention is placed...

  4. Prediction of room acoustical parameters (A)

    DEFF Research Database (Denmark)

    Gade, Anders Christian

    1991-01-01

    During a 6-yr period, detailed room acoustical measurements have been carried out in 35 halls in Denmark and in other European countries. By subjecting these data to statistical analyses, it has been possible to confirm old and establish new relationships between design variables and the position......-averaged acoustical data. The results are presented in the form of linear, multiple regression formulas that may be used to predict the values of the newer measures of level, clarity, spaciousness, and musicians' conditions on the orchestra platform in halls with given RT and geometry....

  5. Rapid geo-acoustic characterization from a seismic survey

    Science.gov (United States)

    Heaney, Kevin D.; Sternlicht, Daniel; Teranishi, Arthur; Castille, Brett; Hamilton, Michael

    2002-05-01

    A recent transmission loss experiment was conducted in Long Beach Harbor for the THUMS Long Beach Company. The objective of the experiment was to measure the range at which the received level was 160 dB for compliance with Marine Mammal regulations. This short experiment provided the opportunity to test the rapid geo-acoustic characterization (RGC) algorithm and perform real-time geo-acoustic inversions from a seismic source. The airgun source transmitted pulses every 20 s corresponding to every 45 m. The water depth was 10-15 m and the water was assumed to be iso-velocity. The data quality was excellent, providing clear striation patterns in the broadband frequency display. The RGC algorithm matches the observed time-spread, striation slope, and TL slope to precomputed values using a normal mode algorithm and parametric geo-acoustic profiles based on Hamilton and Bachman's model. Precomputation of the acoustic observables, combined with real-time signal processing permits real time geo-acoustic characterization.

  6. Polynomial Chaos Based Acoustic Uncertainty Predictions from Ocean Forecast Ensembles

    Science.gov (United States)

    Dennis, S.

    2016-02-01

    Most significant ocean acoustic propagation occurs at tens of kilometers, at scales small compared basin and to most fine scale ocean modeling. To address the increased emphasis on uncertainty quantification, for example transmission loss (TL) probability density functions (PDF) within some radius, a polynomial chaos (PC) based method is utilized. In order to capture uncertainty in ocean modeling, Navy Coastal Ocean Model (NCOM) now includes ensembles distributed to reflect the ocean analysis statistics. Since the ensembles are included in the data assimilation for the new forecast ensembles, the acoustic modeling uses the ensemble predictions in a similar fashion for creating sound speed distribution over an acoustically relevant domain. Within an acoustic domain, singular value decomposition over the combined time-space structure of the sound speeds can be used to create Karhunen-Loève expansions of sound speed, subject to multivariate normality testing. These sound speed expansions serve as a basis for Hermite polynomial chaos expansions of derived quantities, in particular TL. The PC expansion coefficients result from so-called non-intrusive methods, involving evaluation of TL at multi-dimensional Gauss-Hermite quadrature collocation points. Traditional TL calculation from standard acoustic propagation modeling could be prohibitively time consuming at all multi-dimensional collocation points. This method employs Smolyak order and gridding methods to allow adaptive sub-sampling of the collocation points to determine only the most significant PC expansion coefficients to within a preset tolerance. Practically, the Smolyak order and grid sizes grow only polynomially in the number of Karhunen-Loève terms, alleviating the curse of dimensionality. The resulting TL PC coefficients allow the determination of TL PDF normality and its mean and standard deviation. In the non-normal case, PC Monte Carlo methods are used to rapidly establish the PDF. This work was

  7. Acoustic Liquid Handling for Rapid siRNA Transfection Optimization.

    Science.gov (United States)

    Xiao, Andrew S; Lightcap, Eric S; Bouck, David C

    2015-09-01

    Gene knockdown by small interfering RNA (siRNA) has been used extensively to investigate the function of genes in targeted and genome-wide studies. One of the primary challenges of siRNA studies of any scale is to achieve sufficient gene knockdown to produce the biological changes that lead to measurable phenotypes. Reverse, lipid-based transfection efficiency minimally requires the optimization of the following parameters: cell number, knockdown duration, siRNA oligonucleotide concentration, type/brand of transfection lipid, and transfection lipid concentration. In this study, we describe a methodology to utilize the flexibility and low-volume range of the Echo acoustic liquid handler to rapidly screen a matrix of transfection conditions. The matrix includes six different transfection lipids from three separate vendors across a broad range of concentrations. Our results validate acoustic liquid transfer for the delivery of siRNAs and transfection reagents. Finally, this methodology is applied to rapidly optimize transfection conditions across many tissue culture cell lines derived from various originating tissues. © 2015 Society for Laboratory Automation and Screening.

  8. Aero-acoustic noise of wind turbines. Noise prediction models

    Energy Technology Data Exchange (ETDEWEB)

    Maribo Pedersen, B. [ed.

    1997-12-31

    Semi-empirical and CAA (Computational AeroAcoustics) noise prediction techniques are the subject of this expert meeting. The meeting presents and discusses models and methods. The meeting may provide answers to the following questions: What Noise sources are the most important? How are the sources best modeled? What needs to be done to do better predictions? Does it boil down to correct prediction of the unsteady aerodynamics around the rotor? Or is the difficult part to convert the aerodynamics into acoustics? (LN)

  9. Acoustic and Lexical Representations for Affect Prediction in Spontaneous Conversations.

    Science.gov (United States)

    Cao, Houwei; Savran, Arman; Verma, Ragini; Nenkova, Ani

    2015-01-01

    In this article we investigate what representations of acoustics and word usage are most suitable for predicting dimensions of affect|AROUSAL, VALANCE, POWER and EXPECTANCY|in spontaneous interactions. Our experiments are based on the AVEC 2012 challenge dataset. For lexical representations, we compare corpus-independent features based on psychological word norms of emotional dimensions, as well as corpus-dependent representations. We find that corpus-dependent bag of words approach with mutual information between word and emotion dimensions is by far the best representation. For the analysis of acoustics, we zero in on the question of granularity. We confirm on our corpus that utterance-level features are more predictive than word-level features. Further, we study more detailed representations in which the utterance is divided into regions of interest (ROI), each with separate representation. We introduce two ROI representations, which significantly outperform less informed approaches. In addition we show that acoustic models of emotion can be improved considerably by taking into account annotator agreement and training the model on smaller but reliable dataset. Finally we discuss the potential for improving prediction by combining the lexical and acoustic modalities. Simple fusion methods do not lead to consistent improvements over lexical classifiers alone but improve over acoustic models.

  10. Acoustic chemometric prediction of total solids in bioslurry

    DEFF Research Database (Denmark)

    Ihunegbo, Felicia; Madsen, Michael; Esbensen, Kim

    2012-01-01

    several earlier dedicated attempts. A full-scale feasibility study based on standard addition experiments involving natural plant biomass was conducted using multivariate calibration (Partial Least Squares Regression, PLS-R) of acoustic signatures against dry matter content (total solids, TS). Prediction...

  11. Monitoring of rapid sand filters using an acoustic imaging technique

    NARCIS (Netherlands)

    Allouche, N.; Simons, D.G.; Rietveld, L.C.

    2012-01-01

    A novel instrument is developed to acoustically image sand filters used for water treatment and monitor their performance. The instrument consists of an omnidirectional transmitter that generates a chirp with a frequency range between 10 and 110 kHz, and an array of hydrophones. The instrument was

  12. Acoustic prediction of voice type in women with functional dysphonia.

    Science.gov (United States)

    Awan, Shaheen N; Roy, Nelson

    2005-06-01

    The categorization of voice into quality type (ie, normal, breathy, hoarse, rough) is often a traditional part of the voice diagnostic. The goal of this study was to assess the contributions of various time and spectral-based acoustic measures to the categorization of voice type for a diverse sample of voices collected from both functionally dysphonic (breathy, hoarse, and rough) (n=83) and normal women (n=51). Before acoustic analyses, 12 judges rated all voice samples for voice quality type. Discriminant analysis, using the modal rating of voice type as the dependent variable, produced a 5-variable model (comprising time and spectral-based measures) that correctly classified voice type with 79.9% accuracy (74.6% classification accuracy on cross-validation). Voice type classification was achieved based on two significant discriminant functions, interpreted as reflecting measures related to "Phonatory Instability" and "F(0) Characteristics." A cepstrum-based measure (CPP/EXP ratio) consistently emerged as a significant factor in predicting voice type; however, variables such as shimmer (RMS dB) and a measure of low- vs. high-frequency spectral energy (the Discrete Fourier Transformation ratio) also added substantially to the accurate profiling and prediction of voice type. The results are interpreted and discussed with respect to the key acoustic characteristics that contributed to the identification of specific voice types, and the value of identifying a subset of time and spectral-based acoustic measures that appear sensitive to a perceptually diverse set of dysphonic voices.

  13. Seabed variability and its influence on acoustic prediction uncertainty

    Science.gov (United States)

    Holland, Charles W.; Calder, Brian; Kraft, Barbara; Mayer, Larry; Goff, John; Harrison, Chris

    2005-09-01

    Kevin LePage (Naval Research Laboratory, Washington, DC), Robert I. Odom (University of Washington, Applied Physics Laboratory), Irina Overeem, James Syvitski (University of Colorado, INSTAAR, Boulder, CO) and Lincoln Pratson (Duke University, Durham, NC). The weakest link in performance prediction for naval systems operating in coastal regions is the environmental data that drive the models. In shallow-water downward refracting environments, the seabed properties and morphology often are the controlling environmental factors. In order to address the issue of uncertainty in seabed properties, we focused on two overarching goals: (1) assess and characterize seafloor variability in shelf environments, (2) determine the impact of the seafloor variability on acoustic prediction uncertainty. Our inherently multidisciplinary approach brought marine geology/geophysics and ocean acoustics together at the intersection of geoacoustic modeling. This talk will review results from a 3-year collaboration under the ONR Capturing Uncertainty DRI. [Work supported by the Office of Naval Research.

  14. Surface acoustic wave probe implant for predicting epileptic seizures

    Energy Technology Data Exchange (ETDEWEB)

    Gopalsami, Nachappa [Naperville, IL; Kulikov, Stanislav [Sarov, RU; Osorio, Ivan [Leawood, KS; Raptis, Apostolos C [Downers Grove, IL

    2012-04-24

    A system and method for predicting and avoiding a seizure in a patient. The system and method includes use of an implanted surface acoustic wave probe and coupled RF antenna to monitor temperature of the patient's brain, critical changes in the temperature characteristic of a precursor to the seizure. The system can activate an implanted cooling unit which can avoid or minimize a seizure in the patient.

  15. Hyperbaric Oxygen Therapy in Acute Acoustic Trauma: A Rapid Systematic Review

    NARCIS (Netherlands)

    van der Veen, Erwin L.; van Hulst, Rob A.; de Ru, J. Alexander

    2014-01-01

    In this rapid systematic review, we studied the clinical question, What is the effect of hyperbaric oxygen therapy on hearing thresholds in patients who suffered a recent acute acoustic trauma? After screening for eligible titles and abstracts and extracting duplicates, 6 original research papers

  16. A novel method for perceptual assessment of small room acoustics using rapid sensory analysis

    DEFF Research Database (Denmark)

    Kaplanis, Neofytos; Bech, Søren; Lokki, Tapio

    2016-01-01

    small rooms and car cabins. In-situ measurements were performed to obtain a range of possible acoustical settings, by varying physically the spaces under investigation. The measured responses were spatiallyanalyzed and synthesized to reproduce the observed fields in the laboratory. Expert listeners were...... presented with auralized sound over a loudspeaker array and followed a rapid sensory analysis protocol. The elicited attributes and ratings are analyzed and possible links to the acoustical properties of these spaces are discussed. [This study is a part of Marie Curie Network on Dereverberation...

  17. Predicting the intelligibility of deaf children's speech from acoustic measures

    Science.gov (United States)

    Uchanski, Rosalie M.; Geers, Ann E.; Brenner, Christine M.; Tobey, Emily A.

    2004-05-01

    A weighted combination of speech-acoustic measures may provide an objective assessment of speech intelligibility in deaf children that could be used to evaluate the benefits of sensory aids and rehabilitation programs. This investigation compared the accuracy of two different approaches, multiple linear regression and a simple neural net. These two methods were applied to identical sets of acoustic measures, including both segmental (e.g., voice-onset times of plosives, spectral moments of fricatives, second formant frequencies of vowels) and suprasegmental measures (e.g., sentence duration, number and frequency of intersentence pauses). These independent variables were obtained from digitized recordings of deaf children's imitations of 11 simple sentences. The dependent measure was the percentage of spoken words from the 36 McGarr Sentences understood by groups of naive listeners. The two predictive methods were trained on speech measures obtained from 123 out of 164 8- and 9-year-old deaf children who used cochlear implants. Then, predictions were obtained using speech measures from the remaining 41 children. Preliminary results indicate that multiple linear regression is a better predictor of intelligibility than the neural net, accounting for 79% as opposed to 65% of the variance in the data. [Work supported by NIH.

  18. Precoding based channel prediction for underwater acoustic OFDM

    Science.gov (United States)

    Cheng, En; Lin, Na; Sun, Hai-xin; Yan, Jia-quan; Qi, Jie

    2017-04-01

    The life duration of underwater cooperative network has been the hot topic in recent years. And the problem of node energy consuming is the key technology to maintain the energy balance among all nodes. To ensure energy efficiency of some special nodes and obtain a longer lifetime of the underwater cooperative network, this paper focuses on adopting precoding strategy to preprocess the signal at the transmitter and simplify the receiver structure. Meanwhile, it takes into account the presence of Doppler shifts and long feedback transmission delay in an underwater acoustic communication system. Precoding technique is applied based on channel prediction to realize energy saving and improve system performance. Different precoding methods are compared. Simulated results and experimental results show that the proposed scheme has a better performance, and it can provide a simple receiver and realize energy saving for some special nodes in a cooperative communication.

  19. Analytical modelling for predicting the sound field of planar acoustic metasurface

    Science.gov (United States)

    Zhou, Jie; Zhang, Xin; Fang, Yi

    2018-01-01

    An analytical model is built to predict the acoustic fields of acoustic metasurfaces. The acoustic fields are investigated for a Gaussian sound beam incident on the acoustic metasurfaces. The Gaussian sound beam is decomposed into a set of discrete elementary plane waves. The diffraction caused by the acoustic metasurfaces can be obtained using this analytical model, which is validated with the numerical simulations for the different incident angles of the Gaussian sound beam. This model overcomes the limitation of the method based on the generalised Snell's law which can only predict the direction of a specific diffracted order. Actually, this analytical model can be also used to predict the sound fields of acoustic metasurfaces under any incident sound if its Fourier transforms exist. This conclusion is demonstrated by studying the sound field for a point sound source incident on the acoustic metasurface. The acoustic admittances of acoustic metasurfaces are required in the calculation of the analytical model. Therefore, a numerical method for obtaining the effective acoustic admittances is proposed for the structurally complex metasurfaces without the analytical expressions of material properties, such as equivalent density and sound speed.

  20. Prediction of acoustic absorption performance of a perforated plate with air jets

    Science.gov (United States)

    Hamakawa, Hiromitsu; Miyazaki, Masanori; Asai, Yuta; Kurihara, Eru; Nishida, Eiichi; Hayashi, Hidechito

    2017-08-01

    The present study focuses on the prediction of acoustic absorption performance of a perforated plate with air jets by theoretical calculations. In addition, we experimentally measured the flow rate, internal pressure, acoustic pressure, and transfer function using an acoustic impedance tube. The normal incidence absorption coefficient was calculated from the measured transfer function using transfer function methods. We investigated the influences of background air space, flow velocity, thickness, aperture rate, and aperture diameter of a perforated plate on the acoustic absorption characteristics. The frequency characteristics of the acoustic absorption coefficient showed a maximum value at a local frequency. As the background air space increased, the peak frequency of acoustic absorption characteristics decreased. As the flow velocity passing through the apertures increased, the peak level of the acoustic absorption coefficient also increased. The theoretical results agreed well with the experimental ones qualitatively.

  1. Acoustic signal emission monitoring as a novel method to predict steam pops during radiofrequency ablation: preliminary observations.

    Science.gov (United States)

    Chik, William W B; Kosobrodov, Roman; Bhaskaran, Abhishek; Barry, Michael Anthony Tony; Nguyen, Doan Trang; Pouliopoulos, Jim; Byth, Karen; Sivagangabalan, Gopal; Thomas, Stuart P; Ross, David L; McEwan, Alistair; Kovoor, Pramesh; Thiagalingam, Aravinda

    2015-04-01

    Steam pop is an explosive rupture of cardiac tissue caused by tissue overheating above 100 °C, resulting in steam formation, predisposing to serious complications associated with radiofrequency (RF) ablations. However, there are currently no reliable techniques to predict the occurrence of steam pops. We propose the utility of acoustic signals emitted during RF ablation as a novel method to predict steam pop formation and potentially prevent serious complications. Radiofrequency generator parameters (power, impedance, and temperature) were temporally recorded during ablations performed in an in vitro bovine myocardial model. The acoustic system consisted of HTI-96-min hydrophone, microphone preamplifier, and sound card connected to a laptop computer. The hydrophone has the frequency range of 2 Hz to 30 kHz and nominal sensitivity in the range -240 to -165 dB. The sound was sampled at 96 kHz with 24-bit resolution. Output signal from the hydrophone was fed into the camera audio input to synchronize the video stream. An automated system was developed for the detection and analysis of acoustic events. Nine steam pops were observed. Three distinct sounds were identified as warning signals, each indicating rapid steam formation and its release from tissue. These sounds had a broad frequency range up to 6 kHz with several spectral peaks around 2-3 kHz. Subjectively, these warning signals were perceived as separate loud clicks, a quick succession of clicks, or continuous squeaking noise. Characteristic acoustic signals were identified preceding 80% of pops occurrence. Six cardiologists were able to identify 65% of acoustic signals accurately preceding the pop. An automated system identified the characteristic warning signals in 85% of cases. The mean time from the first acoustic signal to pop occurrence was 46 ± 20 seconds. The automated system had 72.7% sensitivity and 88.9% specificity for predicting pops. Easily identifiable characteristic acoustic emissions

  2. Passive acoustic methods for fine-scale tracking of harbour porpoises in tidal rapids

    DEFF Research Database (Denmark)

    Macaulay, Jamie; Gordon, Jonathan; Gillespie, Douglas

    2017-01-01

    The growing interest in generating electrical power from tidal currents using tidal turbine generators raises a number of environmental concerns, including the risk that marine mammals might be injured or killed through collision with rotating turbine blades. To understand this risk, information...... on how marine mammals use tidal rapid habitats and in particular, their underwater movements and dive behaviour is required. Porpoises, which are the most abundant small cetacean at most European tidal sites, are difficult animals to tag, and the limited size of tidal habitats means that any telemetered...... animal would be likely to spend only a small proportion of time within them. Here, an alternative approach is explored, whereby passive acoustic monitoring (PAM) is used to obtain fine scale geo-referenced tracks of harbour porpoises in tidal rapid areas. Large aperture hydrophone arrays are required...

  3. The acoustic sensor for rapid analysis of bacterial cells in the conductive suspensions.

    Science.gov (United States)

    Borodina, I A; Zaitsev, B D; Guliy, O; Teplykh, A A; Shikhabudinov, A M

    2017-11-01

    The possibility of using the acoustic sensor on the basis of a two-channel delay line for rapid analysis of bacterial cells in the conductive suspensions was investigated. The dependencies of change in phase and insertion loss of output signal of the sensor on conductivity of buffer solution with various concentrations of cells due to a specific interaction "bacterial cells - mini-antibodies" for electrically open and electrically shorted channels of delay line were measured. It has been found that these changes have the most values for the electrically open channel. It has been also shown that the sensor rapidly responds to the specific interaction and the time stabilization of the phase and insertion loss of output signal is less than 10min. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Passive acoustic methods for fine-scale tracking of harbour porpoises in tidal rapids.

    Science.gov (United States)

    Macaulay, Jamie; Gordon, Jonathan; Gillespie, Douglas; Malinka, Chloë; Northridge, Simon

    2017-02-01

    The growing interest in generating electrical power from tidal currents using tidal turbine generators raises a number of environmental concerns, including the risk that marine mammals might be injured or killed through collision with rotating turbine blades. To understand this risk, information on how marine mammals use tidal rapid habitats and in particular, their underwater movements and dive behaviour is required. Porpoises, which are the most abundant small cetacean at most European tidal sites, are difficult animals to tag, and the limited size of tidal habitats means that any telemetered animal would be likely to spend only a small proportion of time within them. Here, an alternative approach is explored, whereby passive acoustic monitoring (PAM) is used to obtain fine scale geo-referenced tracks of harbour porpoises in tidal rapid areas. Large aperture hydrophone arrays are required to obtain accurate locations of animals from PAM data and automated algorithms are necessary to process the large quantities of acoustic data collected on such systems during a typical survey. Methods to automate localisation, including a method to match porpoise detections on different hydrophones and separate different vocalising animals, and an assessment of the localisation accuracy of the large aperture hydrophone array are presented.

  5. Modeling Uncertainties in the Prediction of the Acoustic Wavefield in a Shelfbeak Environment

    National Research Council Canada - National Science Library

    Lermusiaux, P. F; Chiu, C.-S; Robinson, A. R

    2001-01-01

    The uncertainties in the predicted acoustic wavefield associated with the transmission of low-frequency sound from the continental slope, through the shelfbreak front, onto the continental shelf are examined...

  6. Acoustic Detail But Not Predictability of Task-Irrelevant Speech Disrupts Working Memory.

    Science.gov (United States)

    Wöstmann, Malte; Obleser, Jonas

    2016-01-01

    Attended speech is comprehended better not only if more acoustic detail is available, but also if it is semantically highly predictable. But can more acoustic detail or higher predictability turn into disadvantages and distract a listener if the speech signal is to be ignored? Also, does the degree of distraction increase for older listeners who typically show a decline in attentional control ability? Adopting the irrelevant-speech paradigm, we tested whether younger (age 23-33 years) and older (60-78 years) listeners' working memory for the serial order of spoken digits would be disrupted by the presentation of task-irrelevant speech varying in its acoustic detail (using noise-vocoding) and its semantic predictability (of sentence endings). More acoustic detail, but not higher predictability, of task-irrelevant speech aggravated memory interference. This pattern of results did not differ between younger and older listeners, despite generally lower performance in older listeners. Our findings suggest that the focus of attention determines how acoustics and predictability affect the processing of speech: first, as more acoustic detail is known to enhance speech comprehension and memory for speech, we here demonstrate that more acoustic detail of ignored speech enhances the degree of distraction. Second, while higher predictability of attended speech is known to also enhance speech comprehension under acoustically adverse conditions, higher predictability of ignored speech is unable to exert any distracting effect upon working memory performance in younger or older listeners. These findings suggest that features that make attended speech easier to comprehend do not necessarily enhance distraction by ignored speech.

  7. Predictive Acoustic Tracking with an Adaptive Neural Mechanism

    DEFF Research Database (Denmark)

    Shaikh, Danish; Manoonpong, Poramate

    2017-01-01

    model of the lizard peripheral auditory system to extract information regarding sound direction. This information is utilised by a neural machinery to learn the acoustic signal’s velocity through fast and unsupervised correlation-based learning adapted from differential Hebbian learning. This approach...... has previously been validated in simulation and via robotic trials to track a continuous pure tone acoustic signal with a semi-circular motion trajectory and a constant but unknown angular velocity. The neural machinery has been shown to be able to learn different target angular velocities...

  8. Lift-Off Acoustics Prediction of Clustered Rocket Engines in the Near Field

    Science.gov (United States)

    Vu, Bruce; Plotkin, Ken

    2010-01-01

    This slide presentation presents a method of predicting acoustics during lift-off of the clustered rocket engines in the near field. Included is a definition of the near field, and the use of deflectors and shielding. There is discussion about the use of PAD, a software system designed to calculate the acoustic levels from the lift of of clustered rocket enginee, including updates to extend the calculation to directivity, water suppression, and clustered nozzles.

  9. Energy- and wave-based beam-tracing prediction of room-acoustical parameters using different boundary conditions.

    Science.gov (United States)

    Yousefzadeh, Behrooz; Hodgson, Murray

    2012-09-01

    A beam-tracing model was used to study the acoustical responses of three empty, rectangular rooms with different boundary conditions. The model is wave-based (accounting for sound phase) and can be applied to rooms with extended-reaction surfaces that are made of multiple layers of solid, fluid, or poroelastic materials-the acoustical properties of these surfaces are calculated using Biot theory. Three room-acoustical parameters were studied in various room configurations: sound strength, reverberation time, and RApid Speech Transmission Index. The main objective was to investigate the effects of modeling surfaces as either local or extended reaction on predicted values of these three parameters. Moreover, the significance of modeling interference effects was investigated, including the study of sound phase-change on surface reflection. Modeling surfaces as of local or extended reaction was found to be significant for surfaces consisting of multiple layers, specifically when one of the layers is air. For multilayers of solid materials with an air-cavity, this was most significant around their mass-air-mass resonance frequencies. Accounting for interference effects made significant changes in the predicted values of all parameters. Modeling phase change on reflection, on the other hand, was found to be relatively much less significant.

  10. Why Does Rapid Naming Predict Chinese Word Reading?

    Science.gov (United States)

    Shum, Kathy Kar-man; Au, Terry Kit-fong

    2017-01-01

    Rapid automatized naming (RAN) robustly predicts early reading abilities across languages, but its underlying mechanism remains unclear. This study found that RAN associated significantly with processing speed but not with phonological awareness or orthographic knowledge in 89 Hong Kong Chinese second-graders. RAN overlaps more with processing…

  11. Leveraging LSTM for rapid intensifications prediction of tropical cyclones

    Science.gov (United States)

    Li, Y.; Yang, R.; Yang, C.; Yu, M.; Hu, F.; Jiang, Y.

    2017-10-01

    Tropical cyclones (TCs) usually cause severe damages and destructions. TC intensity forecasting helps people prepare for the extreme weather and could save lives and properties. Rapid Intensifications (RI) of TCs are the major error sources of TC intensity forecasting. A large number of factors, such as sea surface temperature and wind shear, affect the RI processes of TCs. Quite a lot of work have been done to identify the combination of conditions most favorable to RI. In this study, deep learning method is utilized to combine conditions for RI prediction of TCs. Experiments show that the long short-term memory (LSTM) network provides the ability to leverage past conditions to predict TC rapid intensifications.

  12. Ducted-Fan Engine Acoustic Predictions using a Navier-Stokes Code

    Science.gov (United States)

    Rumsey, C. L.; Biedron, R. T.; Farassat, F.; Spence, P. L.

    1998-01-01

    A Navier-Stokes computer code is used to predict one of the ducted-fan engine acoustic modes that results from rotor-wake/stator-blade interaction. A patched sliding-zone interface is employed to pass information between the moving rotor row and the stationary stator row. The code produces averaged aerodynamic results downstream of the rotor that agree well with a widely used average-passage code. The acoustic mode of interest is generated successfully by the code and is propagated well upstream of the rotor; temporal and spatial numerical resolution are fine enough such that attenuation of the signal is small. Two acoustic codes are used to find the far-field noise. Near-field propagation is computed by using Eversman's wave envelope code, which is based on a finite-element model. Propagation to the far field is accomplished by using the Kirchhoff formula for moving surfaces with the results of the wave envelope code as input data. Comparison of measured and computed far-field noise levels show fair agreement in the range of directivity angles where the peak radiation lobes from the inlet are observed. Although only a single acoustic mode is targeted in this study, the main conclusion is a proof-of-concept: Navier-Stokes codes can be used both to generate and propagate rotor/stator acoustic modes forward through an engine, where the results can be coupled to other far-field noise prediction codes.

  13. A viable method to predict acoustic streaming in presence of cavitation.

    Science.gov (United States)

    Louisnard, O

    2017-03-01

    The steady liquid flow observed under ultrasonic emitters generating acoustic cavitation can be successfully predicted by a standard turbulent flow calculation. The flow is driven by the classical averaged volumetric force density calculated from the acoustic field, but the inertial term in Navier-Stokes equations must be kept, and a turbulent solution must be sought. The acoustic field must be computed with a realistic model, properly accounting for dissipation by the cavitation bubbles [Louisnard, Ultrason. Sonochem., 19, (2012) 56-65]. Comparison with 20kHz experiments, involving the combination of acoustic streaming and a perpendicular forced flow in a duct, shows reasonably good agreement. Moreover, the persistence of the cavitation effects on the wall facing the emitter, in spite of the deflection of the streaming jet, is correctly reproduced by the model. It is also shown that predictions based either on linear acoustics with the correct turbulent solution, or with Louisnard's model with Eckart-Nyborg's theory yields unrealistic results. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Anal acoustic reflectometry predicts the outcome of percutaneous nerve evaluation for faecal incontinence

    DEFF Research Database (Denmark)

    Hornung, B R; Carlson, G L; Mitchell, P J

    2014-01-01

    variables of anal sphincter function measured by anal acoustic reflectometry (AAR) could predict the outcome of PNE for faecal incontinence. METHODS: Women with faecal incontinence undergoing PNE were recruited. AAR, followed by anal manometry, was performed on the day of surgery, immediately before PNE...

  15. Acoustic Characterization and Prediction of Representative, Small-Scale Rotary-Wing Unmanned Aircraft System Components

    Science.gov (United States)

    Zawodny, Nikolas S.; Boyd, D. Douglas, Jr.; Burley, Casey L.

    2016-01-01

    In this study, hover performance and acoustic measurements are taken on two different isolated rotors representative of small-scale rotary-wing unmanned aircraft systems (UAS) for a range of rotation rates. Each rotor system consists of two fixed-pitch blades powered by a brushless motor. For nearly the same thrust condition, significant differences in overall sound pressure level (OASPL), up to 8 dB, and directivity were observed between the two rotor systems. Differences are shown to be in part attributed to different rotor tip speeds, along with increased broadband and motor noise levels. In addition to acoustic measurements, aeroacoustic predictions were implemented in order to better understand the noise content of the rotor systems. Numerical aerodynamic predictions were computed using the unsteady Reynoldsaveraged Navier Stokes code OVERFLOW2 on one of the isolated rotors, while analytical predictions were computed using the Propeller Analysis System of the Aircraft NOise Prediction Program (ANOPP-PAS) on the two rotor configurations. Preliminary semi-empirical frequency domain broadband noise predictions were also carried out based on airfoil self-noise theory in a rotational reference frame. The prediction techniques further supported trends identified in the experimental data analysis. The brushless motors were observed to be important noise contributors and warrant further investigation. It is believed that UAS acoustic prediction capabilities must consider both rotor and motor components as part of a combined noise-generating system.

  16. On Acoustic Source Specification for Rotor-Stator Interaction Noise Prediction

    Science.gov (United States)

    Nark, Douglas M.; Envia, Edmane; Burley, Caesy L.

    2010-01-01

    This paper describes the use of measured source data to assess the effects of acoustic source specification on rotor-stator interaction noise predictions. Specifically, the acoustic propagation and radiation portions of a recently developed coupled computational approach are used to predict tonal rotor-stator interaction noise from a benchmark configuration. In addition to the use of full measured data, randomization of source mode relative phases is also considered for specification of the acoustic source within the computational approach. Comparisons with sideline noise measurements are performed to investigate the effects of various source descriptions on both inlet and exhaust predictions. The inclusion of additional modal source content is shown to have a much greater influence on the inlet results. Reasonable agreement between predicted and measured levels is achieved for the inlet, as well as the exhaust when shear layer effects are taken into account. For the number of trials considered, phase randomized predictions follow statistical distributions similar to those found in previous statistical source investigations. The shape of the predicted directivity pattern relative to measurements also improved with phase randomization, having predicted levels generally within one standard deviation of the measured levels.

  17. Comparison of Comet Enflow and VA One Acoustic-to-Structure Power Flow Predictions

    Science.gov (United States)

    Grosveld, Ferdinand W.; Schiller, Noah H.; Cabell, Randolph H.

    2010-01-01

    Comet Enflow is a commercially available, high frequency vibroacoustic analysis software based on the Energy Finite Element Analysis (EFEA). In this method the same finite element mesh used for structural and acoustic analysis can be employed for the high frequency solutions. Comet Enflow is being validated for a floor-equipped composite cylinder by comparing the EFEA vibroacoustic response predictions with Statistical Energy Analysis (SEA) results from the commercial software program VA One from ESI Group. Early in this program a number of discrepancies became apparent in the Enflow predicted response for the power flow from an acoustic space to a structural subsystem. The power flow anomalies were studied for a simple cubic, a rectangular and a cylindrical structural model connected to an acoustic cavity. The current investigation focuses on three specific discrepancies between the Comet Enflow and the VA One predictions: the Enflow power transmission coefficient relative to the VA One coupling loss factor; the importance of the accuracy of the acoustic modal density formulation used within Enflow; and the recommended use of fast solvers in Comet Enflow. The frequency region of interest for this study covers the one-third octave bands with center frequencies from 16 Hz to 4000 Hz.

  18. Last call: Passive acoustic monitoring shows continued rapid decline of critically endangered vaquita.

    Science.gov (United States)

    Thomas, Len; Jaramillo-Legorreta, Armando; Cardenas-Hinojosa, Gustavo; Nieto-Garcia, Edwyna; Rojas-Bracho, Lorenzo; Ver Hoef, Jay M; Moore, Jeffrey; Taylor, Barbara; Barlow, Jay; Tregenza, Nicholas

    2017-11-01

    The vaquita is a critically endangered species of porpoise. It produces echolocation clicks, making it a good candidate for passive acoustic monitoring. A systematic grid of sensors has been deployed for 3 months annually since 2011; results from 2016 are reported here. Statistical models (to compensate for non-uniform data loss) show an overall decline in the acoustic detection rate between 2015 and 2016 of 49% (95% credible interval 82% decline to 8% increase), and total decline between 2011 and 2016 of over 90%. Assuming the acoustic detection rate is proportional to population size, approximately 30 vaquita (95% credible interval 8-96) remained in November 2016.

  19. Prediction of ovulation in women using a rapid progesterone radioimmunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Fleming, R.; Coults, J.R.T. (Glasgow Univ. (UK))

    1982-02-01

    A rapid (3-h) radioimmunoassay of plasma progesterone has been developed and used successfully to predict the time of ovulation in women undergoing artificial insemination. The results obtained using progesterone levels to date the stage of the cycle were analysed retrospectively by (1) estimation of the length of the ensuing luteal phases and comparison of these with luteal phase lengths of a control group (2) comparison of the dating using progesterone levels with retrospective determination of LH values and (3) by analysis of the dating in cycles in which conception occurred.

  20. Prediction of the acoustic and bubble fields in insonified freeze-drying vials.

    Science.gov (United States)

    Louisnard, O; Cogné, C; Labouret, S; Montes-Quiroz, W; Peczalski, R; Baillon, F; Espitalier, F

    2015-09-01

    The acoustic field and the location of cavitation bubble are computed in vials used for freeze-drying, insonified from the bottom by a vibrating plate. The calculations rely on a nonlinear model of sound propagation in a cavitating liquid [Louisnard, Ultrason. Sonochem., 19, (2012) 56-65]. Both the vibration amplitude and the liquid level in the vial are parametrically varied. For low liquid levels, a threshold amplitude is required to form a cavitation zone at the bottom of the vial. For increasing vibration amplitudes, the bubble field slightly thickens but remains at the vial bottom, and the acoustic field saturates, which cannot be captured by linear acoustics. On the other hand, increasing the liquid level may promote the formation of a secondary bubble structure near the glass wall, a few centimeters below the free liquid surface. These predictions suggest that rather complex acoustic fields and bubble structures can arise even in such small volumes. As the acoustic and bubble fields govern ice nucleation during the freezing step, the final crystal's size distribution in the frozen product may crucially depend on the liquid level in the vial. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Music-induced emotions can be predicted from a combination of brain activity and acoustic features.

    Science.gov (United States)

    Daly, Ian; Williams, Duncan; Hallowell, James; Hwang, Faustina; Kirke, Alexis; Malik, Asad; Weaver, James; Miranda, Eduardo; Nasuto, Slawomir J

    2015-12-01

    It is widely acknowledged that music can communicate and induce a wide range of emotions in the listener. However, music is a highly-complex audio signal composed of a wide range of complex time- and frequency-varying components. Additionally, music-induced emotions are known to differ greatly between listeners. Therefore, it is not immediately clear what emotions will be induced in a given individual by a piece of music. We attempt to predict the music-induced emotional response in a listener by measuring the activity in the listeners electroencephalogram (EEG). We combine these measures with acoustic descriptors of the music, an approach that allows us to consider music as a complex set of time-varying acoustic features, independently of any specific music theory. Regression models are found which allow us to predict the music-induced emotions of our participants with a correlation between the actual and predicted responses of up to r=0.234,pmusic induced emotions can be predicted by their neural activity and the properties of the music. Given the large amount of noise, non-stationarity, and non-linearity in both EEG and music, this is an encouraging result. Additionally, the combination of measures of brain activity and acoustic features describing the music played to our participants allows us to predict music-induced emotions with significantly higher accuracies than either feature type alone (p<0.01). Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Reduced-Order Models for Acoustic Response Prediction

    Science.gov (United States)

    2011-07-01

    predicted frequencies from a FEM. The first two axial natural frequencies were measured using a pair of small piezoelectric strain actuators, one...test. Displacement and velocity relative to the shaker head were measured with a Polytec Model OVF-512 Differential Fiber Optic Vibrometer . The...The vibrometer controller processes the object and reference beams to produce differential velocity and displacement. Dynamic strains were

  3. A simple formula for insertion loss prediction of large acoustical enclosures using statistical energy analysis method

    Directory of Open Access Journals (Sweden)

    Kim Hyun-Sil

    2014-12-01

    Full Text Available Insertion loss prediction of large acoustical enclosures using Statistical Energy Analysis (SEA method is presented. The SEA model consists of three elements: sound field inside the enclosure, vibration energy of the enclosure panel, and sound field outside the enclosure. It is assumed that the space surrounding the enclosure is sufficiently large so that there is no energy flow from the outside to the wall panel or to air cavity inside the enclosure. The comparison of the predicted insertion loss to the measured data for typical large acoustical enclosures shows good agreements. It is found that if the critical frequency of the wall panel falls above the frequency region of interest, insertion loss is dominated by the sound transmission loss of the wall panel and averaged sound absorption coefficient inside the enclosure. However, if the critical frequency of the wall panel falls into the frequency region of interest, acoustic power from the sound radiation by the wall panel must be added to the acoustic power from transmission through the panel.

  4. Prediction of Equipment Failures by Acoustical Signature Analysis - Phase 1

    Science.gov (United States)

    1976-12-01

    are present. Depot MAIDS is a computerized test system used in instrumented dynamometer cells at Letterkenny Army Depot. Many pressure, temperature...and a portable dynamometer are used so that the unit is mobile. 2 -.. STEAP-MT-G SUBJECT: Final Letter Report of Phase I of Prediction of Equipment...tree structure is that of clustering. It is desirable to define the smaller subclasses (e.g. sticking valves and loose wrist pins) to be grouped together

  5. Frequency regularities of acoustic modes and multi-colour mode identification in rapidly rotating stars

    Science.gov (United States)

    Reese, D. R.; Lignières, F.; Ballot, J.; Dupret, M.-A.; Barban, C.; van't Veer-Menneret, C.; MacGregor, K. B.

    2017-05-01

    Context. Mode identification has remained a major obstacle in the interpretation of pulsation spectra in rapidly rotating stars. This has motivated recent work on calculating realistic multi-colour mode visibilities in this type of star. Aims: We would like to test mode identification methods and seismic diagnostics in rapidly rotating stars, using oscillation spectra that are based on these new theoretical predictions. Methods: We investigate the auto-correlation function and Fourier transform of theoretically calculated frequency spectra, in which modes are selected according to their visibilities. Given that intrinsic mode amplitudes are determined by non-linear saturation and cannot currently be theoretically predicted, we experimented with various ad-hoc prescriptions for setting the mode amplitudes, including using random values. Furthermore, we analyse the ratios between mode amplitudes observed in different photometric bands to see up to what extent they can identify modes. Results: When non-random intrinsic mode amplitudes are used, our results show that it is possible to extract a mean value for the large frequency separation or half its value and, sometimes, twice the rotation rate, from the auto-correlation of the frequency spectra. Furthermore, the Fourier transforms are mostly sensitive to the large frequency separation or half its value. The combination of the two methods may therefore measure and distinguish the two types of separations. When the intrinsic mode amplitudes include random factors, which seems more representative of real stars, the results are far less favourable. It is only when the large separation or half its value coincides with twice the rotation rate, that it might be possible to detect the signature of a frequency regularity. We also find that amplitude ratios are a good way of grouping together modes with similar characteristics. By analysing the frequencies of these groups, it is possible to constrain mode identification, as

  6. Rapid Salmonella detection using an acoustic wave device combined with the RCA isothermal DNA amplification method

    Directory of Open Access Journals (Sweden)

    Antonis Kordas

    2016-12-01

    Full Text Available Salmonella enterica serovar Typhimurium is a major foodborne pathogen that causes Salmonellosis, posing a serious threat for public health and economy; thus, the development of fast and sensitive methods is of paramount importance for food quality control and safety management. In the current work, we are presenting a new approach where an isothermal amplification method is combined with an acoustic wave device for the development of a label free assay for bacteria detection. Specifically, our method utilizes a Love wave biosensor based on a Surface Acoustic Wave (SAW device combined with the isothermal Rolling Circle Amplification (RCA method; various protocols were tested regarding the DNA amplification and detection, including off-chip amplification at two different temperatures (30 °C and room temperature followed by acoustic detection and on-chip amplification and detection at room temperature, with the current detection limit being as little as 100 Bacteria Cell Equivalents (BCE/sample. Our acoustic results showed that the acoustic ratio, i.e., the amplitude over phase change observed during DNA binding, provided the only sensitive means for product detection while the measurement of amplitude or phase alone could not discriminate positive from negative samples. The method's fast analysis time together with other inherent advantages i.e., portability, potential for multi-analysis, lower sample volumes and reduced power consumption, hold great promise for employing the developed assay in a Lab on Chip (LoC platform for the integrated analysis of Salmonella in food samples.

  7. Predicting vibratory stresses from aero-acoustic loads

    Science.gov (United States)

    Shaw, Matthew D.

    Sonic fatigue has been a concern of jet aircraft engineers for many years. As engines become more powerful, structures become more lightly damped and complex, and materials become lighter, stiffer, and more complicated, the need to understand and predict structural response to aeroacoustic loads becomes more important. Despite decades of research, vibration in panels caused by random pressure loads, such as those found in a supersonic jet, is still difficult to predict. The work in this research improves on current prediction methods in several ways, in particular for the structural response due to wall pressures induced by supersonic turbulent flows. First, solutions are calculated using time-domain input pressure loads that include shock cells and their interaction with turbulent flow. The solutions include both mean (static) and oscillatory components. Second, the time series of stresses are required for many fatigue assessment counting algorithms. To do this, a method is developed to compute time-dependent solutions in the frequency domain. The method is first applied to a single-degree-of-freedom system. The equations of motion are derived and solved in both the frequency domain and the time domain. The pressure input is a random (broadband) signal representative of jet flow. The method is then applied to a simply-supported beam vibrating in flexure using a line of pressure inputs computed with computational fluid dynamics (CFD). A modal summation approach is used to compute structural response. The coupling between the pressure field and the structure, through the joint acceptance, is reviewed and discussed for its application to more complicated structures. Results from the new method and from a direct time domain method are compared for method verification. Because the match is good and the new frequency domain method is faster computationally, it is chosen for use in a more complicated structure. The vibration of a two-dimensional panel loaded by jet

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

    Science.gov (United States)

    Martellotta, Francesco

    2009-09-01

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

  9. Contributions of rapid neuromuscular transmission to the fine control of acoustic parameters of birdsong.

    Science.gov (United States)

    Mencio, Caitlin; Kuberan, Balagurunathan; Goller, Franz

    2017-02-01

    Neural control of complex vocal behaviors, such as birdsong and speech, requires integration of biomechanical nonlinearities through muscular output. Although control of airflow and tension of vibrating tissues are known functions of vocal muscles, it remains unclear how specific muscle characteristics contribute to specific acoustic parameters. To address this gap, we removed heparan sulfate chains using heparitinases to perturb neuromuscular transmission subtly in the syrinx of adult male zebra finches (Taeniopygia guttata). Infusion of heparitinases into ventral syringeal muscles altered their excitation threshold and reduced neuromuscular transmission changing their ability to modulate airflow. The changes in muscle activation dynamics caused a reduction in frequency modulation rates and elimination of many high-frequency syllables but did not alter the fundamental frequency of syllables. Sound amplitude was reduced and sound onset pressure was increased, suggesting a role of muscles in the induction of self-sustained oscillations under low-airflow conditions, thus enhancing vocal efficiency. These changes were reversed to preinfusion levels by 7 days after infusion. These results illustrate complex interactions between the control of airflow and tension and further define the importance of syringeal muscle in the control of a variety of acoustic song characteristics. In summary, the findings reported here show that altering neuromuscular transmission can lead to reversible changes to the acoustic structure of song. Understanding the full extent of muscle involvement in song production is critical in decoding the motor program for the production of complex vocal behavior, including our search for parallels between birdsong and human speech motor control. It is largely unknown how fine motor control of acoustic parameters is achieved in vocal organs. Subtle manipulation of syringeal muscle function was used to test how active motor control influences acoustic

  10. The Prediction of Jet Noise Ground Effects Using an Acoustic Analogy and a Tailored Green's Function

    Science.gov (United States)

    Miller, Steven A. E.

    2013-01-01

    An assessment of an acoustic analogy for the mixing noise component of jet noise in the presence of an infinite surface is presented. The reflection of jet noise by the ground changes the distribution of acoustic energy and is characterized by constructive and destructive interference patterns. The equivalent sources are modeled based on the two-point cross- correlation of the turbulent velocity fluctuations and a steady Reynolds-Averaged Navier-Stokes (RANS) solution. Propagation effects, due to reflection by the surface and refaction by the jet shear layer, are taken into account by calculating the vector Green's function of the linearized Euler equations (LEE). The vector Green's function of the LEE is written in relation to Lilley's equation; that is, approximated with matched asymptotic solutions and the Green's function of the convective Helmholtz equation. The Green's function of the convective Helmholtz equation for an infinite flat plane with impedance is the Weyl-van der Pol equation. Predictions are compared with an unheated Mach 0.95 jet produced by a nozzle with an exit diameter of 0.3302 meters. Microphones are placed at various heights and distances from the nozzle exit in the peak jet noise direction above an acoustically hard and an asphalt surface. The predictions are shown to accurately capture jet noise ground effects that are characterized by constructive and destructive interference patterns in the mid- and far-field and capture overall trends in the near-field.

  11. Prediction of the acoustical performance of enclosures using a hybrid statistical energy analysis: image source model.

    Science.gov (United States)

    Sgard, Franck; Nelisse, Hugues; Atalla, Noureddine; Amedin, Celse Kafui; Oddo, Remy

    2010-02-01

    Enclosures are commonly used to reduce the sound exposure of workers to the noise radiated by machinery. Some acoustic predictive tools ranging from simple analytical tools to sophisticated numerical deterministic models are available to estimate the enclosure acoustical performance. However, simple analytical models are usually valid in limited frequency ranges because of underlying assumptions whereas numerical models are commonly limited to low frequencies. This paper presents a general and simple model for predicting the acoustic performance of large free-standing enclosures which is capable of taking into account the complexity of the enclosure configuration and covering a large frequency range. It is based on the statistical energy analysis (SEA) framework. The sound field inside the enclosure is calculated using the method of image sources. Sound transmission across the various elements of the enclosure is considered in the SEA formalism. The model is evaluated by comparison with existing methods and experimental results. The effect of several parameters such as enclosure geometry, panel materials, presence of noise control treatments, location of the source inside the enclosure, and presence of an opening has been investigated. The comparisons between the model and the experimental results show a good agreement for most of the tested configurations.

  12. Prediction and near-field observation of skull-guided acoustic waves

    CERN Document Server

    Estrada, Héctor; Razansky, Daniel

    2016-01-01

    Ultrasound waves propagating in water or soft biological tissue are strongly reflected when encountering the skull, which limits the use of ultrasound-based techniques in transcranial imaging and therapeutic applications. Current knowledge on the acoustic properties of the cranial bone is restricted to far-field observations, leaving its near-field properties unexplored. We report on the existence of skull-guided acoustic waves, which was herein confirmed by near-field measurements of optoacoustically-induced responses in ex-vivo murine skulls immersed in water. Dispersion of the guided waves was found to reasonably agree with the prediction of a multilayered flat plate model. It is generally anticipated that our findings may facilitate and broaden the application of ultrasound-mediated techniques in brain diagnostics and therapy.

  13. The Prediction of Metal Slopping in LD Converter on Base an Acoustic Signal

    Directory of Open Access Journals (Sweden)

    Kostúr, K.

    2006-01-01

    Full Text Available The negative influences of slopping in a BOF are pollution to the environment. They give lower yield and cause equipment damage. The prediction of these phenomena is based on information processing from the measuring microphone. The change of frequency in certain range is done by a signal for the prediction of slopping. In this paper two methods for prediction of slopping are described. The first method is based on measuring and processing of sound emitted from the vessel during the blow. The second method utilizes Fourier’s transformation for processing of acoustic signal from sonic meter. The success rate of prediction has been evaluated by help of five criterions. It is possible to forecast the slopping on selected frequency (band. It is the essence of the second method, because this method has high success (criterion K1. Note, that criterion K5 defines acknowledgment of duration slopping. This criterion has the highest value.

  14. Rapid calculation of acoustic fields from arbitrary continuous-wave sources.

    Science.gov (United States)

    Treeby, Bradley E; Budisky, Jakub; Wise, Elliott S; Jaros, Jiri; Cox, B T

    2018-01-01

    A Green's function solution is derived for calculating the acoustic field generated by phased array transducers of arbitrary shape when driven by a single frequency continuous wave excitation with spatially varying amplitude and phase. The solution is based on the Green's function for the homogeneous wave equation expressed in the spatial frequency domain or k-space. The temporal convolution integral is solved analytically, and the remaining integrals are expressed in the form of the spatial Fourier transform. This allows the acoustic pressure for all spatial positions to be calculated in a single step using two fast Fourier transforms. The model is demonstrated through several numerical examples, including single element rectangular and spherically focused bowl transducers, and multi-element linear and hemispherical arrays.

  15. Prediction of Acoustically Induced Random Vibration Response of Satellite Equipments with Proposed Asymptotic Apparent Mass

    Science.gov (United States)

    Ando, Shigemasa; Shi, Qinzhong

    Acoustically induced random vibration of satellite equipment mounted on honeycomb panels is a critical design consideration in satellite equipment development. Prediction of this random vibration is performed in the early stage of satellite design to specify the design limit value of random vibration excitation for satellite equipment. Various prediction methods for response prediction using Statistical Energy Analysis (SEA) have been developed: (i) NASA Lewis method, (ii) point-mass impedance method, and (iii) area-coupling impedance method. However, the first method has limited accuracy for heavy and concentrated equipment, the second one often overestimates, and the third one requires a detailed parameter. A new method combining the asymptotic apparent mass of specific equipment with NASA Lewis method is proposed herein. This proposed method takes the elastic behavior of satellite equipment rather than a rigid mass. The acoustic excitation experiments for nine real satellites (404 equipments in all) were conducted to compare existing methods to the proposed method statistically. Results show that the proposed method provides the most accurate prediction in the important frequency range.

  16. Prediction and near-field observation of skull-guided acoustic waves

    Science.gov (United States)

    Estrada, Héctor; Rebling, Johannes; Razansky, Daniel

    2017-06-01

    Ultrasound waves propagating in water or soft biological tissue are strongly reflected when encountering the skull, which limits the use of ultrasound-based techniques in transcranial imaging and therapeutic applications. Current knowledge on the acoustic properties of the cranial bone is restricted to far-field observations, leaving its near-field unexplored. We report on the existence of skull-guided acoustic waves, which was herein confirmed by near-field measurements of optoacoustically-induced responses in ex-vivo murine skulls immersed in water. Dispersion of the guided waves was found to reasonably agree with the prediction of a multilayered flat plate model. We observed a skull-guided wave propagation over a lateral distance of at least 3 mm, with a half-decay length in the direction perpendicular to the skull ranging from 35 to 300 μm at 6 and 0.5 MHz, respectively. Propagation losses are mostly attributed to the heterogenous acoustic properties of the skull. It is generally anticipated that our findings may facilitate and broaden the application of ultrasound-mediated techniques in brain diagnostics and therapy.

  17. Enhancing acoustic signal quality by rapidly switching between pulse-echo and through-transmission using diplexers

    Science.gov (United States)

    Valencia, Juan D.; Diaz, Aaron A.; Tucker, Brian J.

    2008-03-01

    The increase of terrorism and its global impact has made the screening of the contents of liquid-filled containers a necessity. The ability to evaluate the contents of a container rapidly and accurately is a critical tool in maintaining global safety and security. Due to the immense quantities and large variety of containers shipped worldwide, there is a need for a technology that enables rapid and effective ways of conducting non-intrusive container inspections. Such inspections can be performed utilizing "through-transmission" or "pulse-echo" acoustic techniques, in combination with multiple frequency excitation pulses or waveforms. The challenge is combining and switching between the different acoustic techniques without distorting the excitation pulse or waveform, degrading or adding noise to the receive signal; while maintaining a portable, low-power, low-cost, and easy to use system. The Pacific Northwest National Laboratory (PNNL) has developed a methodology and prototype device focused on this challenge. The prototype relies on an advanced diplexer circuit capable of rapidly switching between both "through-transmission" and "pulse-echo" detection modes. This type of detection requires the prototype to isolate the pulsing circuitry from the receiving circuitry to prevent damage and reduce noise. The results of this work demonstrate that an advanced diplexer circuit can be effective; however, some bandwidth issues exist. This paper focuses on laboratory measurements and test results acquired with the PNNL prototype device as applied to several types of liquid-filled containers. Results of work conducted in the laboratory will be presented and future measurement platform enhancements will be discussed.

  18. Prediction of acoustic foam properties by numerical simulation of polyurethane foaming process

    Directory of Open Access Journals (Sweden)

    Abdessalam Hichem

    2016-01-01

    Full Text Available This work aims to model and to simulate the polyurethane foaming process. Models taking into account the two main chemical reactions of the formation of polyurethane, the exothermic effect of these reactions as well as the thermo-rheo-kinetic coupling characterizing this process are proposed and implemented in the software NOGRID-points based on a meshless method (Finite Pointset Method. A prediction of some acoustic foam characteristics is also proposed based on the results of the numerical simulation of the foaming process and semi-phenomenological models.

  19. Prediction of thermal acoustic oscillations (TAOs) in the CLAES solid CO2/neon system

    Science.gov (United States)

    Spradley, I. E.; Yuan, S. W. K.

    1991-01-01

    Results are presented of a study initiated to investigate the possibility that the existence of thermal acoustic oscillations (TAOs) in the Cryogenic Limb Atmospheric Etalon Spectrometer (CLAES) neon plumbing system ground configuration could be the cause of higher-than-predicted heat rates measured during thermal ground testing. Tests were conducted between warm boundary temperatures ranging from 40 to 100 K, which simulated the actual test conditions of the CLAES CO2/neon system. TAOs were observed between 6 and 106 Torr, which agreed with the analytical predictions, and verified the possible existence of TAOs in the CLAES system during ground testing. The presence of TAOs was eventually confirmed in the CLAES system during a subsequent thermal test and were determined to have caused the higher heat rates measured during the prior thermal test.

  20. Frequency-space prediction filtering for acoustic clutter and random noise attenuation in ultrasound imaging

    Science.gov (United States)

    Shin, Junseob; Huang, Lianjie

    2016-04-01

    Frequency-space prediction filtering (FXPF), also known as FX deconvolution, is a technique originally developed for random noise attenuation in seismic imaging. FXPF attempts to reduce random noise in seismic data by modeling only real signals that appear as linear or quasilinear events in the aperture domain. In medical ultrasound imaging, channel radio frequency (RF) signals from the main lobe appear as horizontal events after receive delays are applied while acoustic clutter signals from off-axis scatterers and electronic noise do not. Therefore, FXPF is suitable for preserving only the main-lobe signals and attenuating the unwanted contributions from clutter and random noise in medical ultrasound imaging. We adapt FXPF to ultrasound imaging, and evaluate its performance using simulated data sets from a point target and an anechoic cyst. Our simulation results show that using only 5 iterations of FXPF achieves contrast-to-noise ratio (CNR) improvements of 67 % in a simulated noise-free anechoic cyst and 228 % in a simulated anechoic cyst contaminated with random noise of 15 dB signal-to-noise ratio (SNR). Our findings suggest that ultrasound imaging with FXPF attenuates contributions from both acoustic clutter and random noise and therefore, FXPF has great potential to improve ultrasound image contrast for better visualization of important anatomical structures and detection of diseased conditions.

  1. High-Fidelity Prediction of Launch Vehicle Lift-off Acoustic Environment Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Launch vehicles experience extreme acoustic loads during liftoff driven by the interaction of rocket plumes and plume-generated acoustic waves with ground...

  2. Computational Appliance for Rapid Prediction of Aircraft Trajectories Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Next generation air traffic management systems will be based to a greater degree on predicted trajectories of aircraft. Due to the iterative nature of future air...

  3. Rapid persulfate oxidation predicts PAH bioavailability in soils and sediments

    NARCIS (Netherlands)

    Cuypers, M.P.; Grotenhuis, J.T.C.; Joziasse, J.; Rulkens, W.H.

    2000-01-01

    Persulfate oxidation was validated as a method to predict polycyclic aromatic hydrocarbon (PAH) bioavailability in soils and sediments. It was demonstrated for 14 field contaminated soils and sediments that residual PAH concentrations after a short (3 h) persulfate oxidation correspond well to

  4. Response variability in rapid automatized naming predicts reading comprehension.

    Science.gov (United States)

    Li, James J; Cutting, Laurie E; Ryan, Matthew; Zilioli, Monica; Denckla, Martha B; Mahone, E Mark

    2009-10-01

    A total of 37 children ages 8 to 14 years, screened for word-reading difficulties (23 with attention-deficit/hyperactivity disorder, ADHD; 14 controls) completed oral reading and rapid automatized naming (RAN) tests. RAN trials were segmented into pause and articulation time and intraindividual variability. There were no group differences on reading or RAN variables. Color- and letter-naming pause times and number-naming articulation time were significant predictors of reading fluency. In contrast, number and letter pause variability were predictors of comprehension. Results support analysis of subcomponents of RAN and add to literature emphasizing intraindividual variability as a marker for response preparation, which has relevance to reading comprehension.

  5. Correlation of FEM/BEM Vibroacoustic Prediction to System-Level Acoustic Test Results

    Science.gov (United States)

    Rodrigues, G.; Ngan, I.; Santiago-Prowald, J.

    2014-06-01

    Coupled FEM/BEM vibroacoustic analyses are employed for deriving spacecraft random vibration environments and supporting the design of low aerial density structures. They offer deterministic predictions which are very accurate at low-frequency and meaningful across all the spectrum of interest for vibroacoustic response.An assessment of the standard procedure of FEM/BEM vibroacoustic analyses was carried out by correlation to measurements from system-level tests of several spacecraft. This allowed a quantification of the typical errors committed, and concluded on the adequacy of applying the standard factor of safety +4dB to the predictions. It was observed that a major source of error is the lack of representativeness of the models of the spacecraft, which adds to the diffuse field idealization made on the acoustic environment inside the fairing and the test chambers. In particular, it was observed a clear impact from a lack of detail of the damping of the structure, and an often crude lumped representation of units and equipment as well as tanks and fixations.

  6. TU-G-210-03: Acoustic Simulations in Transcranial MRgFUS: Treatment Prediction and Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Vyas, U. [Stanford University (United States)

    2015-06-15

    Modeling can play a vital role in predicting, optimizing and analyzing the results of therapeutic ultrasound treatments. Simulating the propagating acoustic beam in various targeted regions of the body allows for the prediction of the resulting power deposition and temperature profiles. In this session we will apply various modeling approaches to breast, abdominal organ and brain treatments. Of particular interest is the effectiveness of procedures for correcting for phase aberrations caused by intervening irregular tissues, such as the skull in transcranial applications or inhomogeneous breast tissues. Also described are methods to compensate for motion in targeted abdominal organs such as the liver or kidney. Douglas Christensen – Modeling for Breast and Brain HIFU Treatment Planning Tobias Preusser – TRANS-FUSIMO - An Integrative Approach to Model-Based Treatment Planning of Liver FUS Urvi Vyas – Acoustic Simulations in Transcranial MRgFUS: Treatment Prediction and Analysis Learning Objectives: Understand the role of acoustic beam modeling for predicting the effectiveness of therapeutic ultrasound treatments. Apply acoustic modeling to specific breast, liver, kidney and transcranial anatomies. Determine how to obtain appropriate acoustic modeling parameters from clinical images. Understand the separate role of absorption and scattering in energy delivery to tissues. See how organ motion can be compensated for in ultrasound therapies. Compare simulated data with clinical temperature measurements in transcranial applications. Supported by NIH R01 HL172787 and R01 EB013433 (DC); EU Seventh Framework Programme (FP7/2007-2013) under 270186 (FUSIMO) and 611889 (TRANS-FUSIMO)(TP); and P01 CA159992, GE, FUSF and InSightec (UV)

  7. A Neural Substrate for Rapid Timbre Recognition? Neural and Behavioral Discrimination of Very Brief Acoustic Vowels.

    Science.gov (United States)

    Occelli, F; Suied, C; Pressnitzer, D; Edeline, J-M; Gourévitch, B

    2016-06-01

    The timbre of a sound plays an important role in our ability to discriminate between behaviorally relevant auditory categories, such as different vowels in speech. Here, we investigated, in the primary auditory cortex (A1) of anesthetized guinea pigs, the neural representation of vowels with impoverished timbre cues. Five different vowels were presented with durations ranging from 2 to 128 ms. A psychophysical experiment involving human listeners showed that identification performance was near ceiling for the longer durations and degraded close to chance level for the shortest durations. This was likely due to spectral splatter, which reduced the contrast between the spectral profiles of the vowels at short durations. Effects of vowel duration on cortical responses were well predicted by the linear frequency responses of A1 neurons. Using mutual information, we found that auditory cortical neurons in the guinea pig could be used to reliably identify several vowels for all durations. Information carried by each cortical site was low on average, but the population code was accurate even for durations where human behavioral performance was poor. These results suggest that a place population code is available at the level of A1 to encode spectral profile cues for even very short sounds. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  8. A rapid, small-scale sedimentation method to predict breadmaking quality of hard winter wheat

    Science.gov (United States)

    Breeders and processors are always looking for rapid and accurate methods to evaluate wheat quality. A rapid small-scale hybrid sedimentation method was developed for predicting breadmaking quality of breeders samples by combining the sodium dodecyl-sulfate (SDS) sedimentation method (AACC 56-70) an...

  9. Transmission loss patterns from acoustic harassment and deterrent devices do not always follow geometrical spreading predictions

    DEFF Research Database (Denmark)

    Shapiro, A.D.; Tougaard, J.; Jørgensen, P.B.

    2009-01-01

    Acoustic harassment and deterrent devices have become increasingly popular mitigation tools for negotiating the impacts of marine mammals on fisheries. The rationale for their variable effectiveness remains unexplained, but high variability in the surrounding acoustic field may be relevant....... In the present study, the sound fields of one acoustic harassment device and three acoustic deterrent devices were measured at three study sites along the Scandinavian coast. Superimposed onto an overall trend of decreasing sound exposure levels with increasing range were large local variations in the sound...

  10. Rapid Prediction of Configuration Aerodynamics in the ConceptualDesign Phase

    Directory of Open Access Journals (Sweden)

    C. Munro

    2001-01-01

    Full Text Available Conceptual aircraft design is characterised by the requirement to analyse a large number of configurations rapidly and cost effectively. For unusual configurations such as those typified by unmanned combat air vehicles (UCAVs adequately predicting their aerodynamic characteristics through existing empirical methods is fraught with uncertainty. By utilising rapid and low cost experimental tools such as the water tunnel and subscale flight testing it is proposed that the required aerodynamic characteristics can rapidly be acquired with sufficient fidelity for the conceptual design phase. Furthermore, the initial design predictions can to some extent be validated using flight-derived aerodynamic data from subscale flight testing.

  11. Prediction of sound insulation in buildings: a tool to improve the acoustic quality

    NARCIS (Netherlands)

    Gerretsen, E.

    2003-01-01

    Noise from neighbours is an important item in the acoustic climate in which we live and work. And yet the requirements remain essentially the same as fifty years ago, though the noise situation in and around dwellings has changed. In the past the acoustic performance of a building design could

  12. Prediction and validation of high frequency vibration repsonses of NASA Mars Pathfinder spacecraft due to acoustic launch load using statistical energy analysis

    Science.gov (United States)

    Hwang, H. J.

    2002-01-01

    Mid and high frequency structural responses of a spacecraft during the launch condition are mainly dominated by the intense acoustic pressure field over the exterior of the launch vehicle. The prediction of structural responses due to the acoustic launch load is therefore an important analysis for engineers and scientists to correctly define various dynamics specifications of the spacecraft.

  13. Beyond Phonology: Visual Processes Predict Alphanumeric and Nonalphanumeric Rapid Naming in Poor Early Readers

    Science.gov (United States)

    Kruk, Richard S.; Luther Ruban, Cassia

    2018-01-01

    Visual processes in Grade 1 were examined for their predictive influences in nonalphanumeric and alphanumeric rapid naming (RAN) in 51 poor early and 69 typical readers. In a lagged design, children were followed longitudinally from Grade 1 to Grade 3 over 5 testing occasions. RAN outcomes in early Grade 2 were predicted by speeded and nonspeeded…

  14. Validity of linear acoustics for prediction of waveforms caused by sonically moving laser beams.

    Science.gov (United States)

    Pierce, A D; Berthelot, Y H

    1988-03-01

    The question is raised as to whether the analysis of the generation of sound by a laser beam moving over a water surface at the sound speed c for an interminable time period requires consideration of nonlinear effects. A principal consideration in this regard is whether the linear acoustics theory predicts a pressure waveform that is bounded in the asymptotic limit when the laser irradiation time is arbitrarily large. It is shown that a bounded asymptotic limit exists when the upper boundary condition corresponds (as is more nearly appropriate) to that of a pressure release surface, but not when it corresponds to that of a rigid surface. The asymptotic solution to the appropriate inhomogeneous wave equation is given exactly for the former case, and it is shown that the highest asymptotic amplitudes, given specified laser power and beam radius a, occur in the limit of a very small light absorption coefficient mu. In this limit, the peak amplitude is independent of mu and occurs at a depth of 0.88/mu. An approximate solution for the pressure waveform at intermediate times establishes that the characteristic time for buildup to the asymptotic limit is of the order of 2.5/(c mu 2a). If this time is substantially shorter than the time that a plane-wave pulse with the asymptotic waveform would take to develop a shock wave, then accumulative nonlinear effects are of minor importance.

  15. Spatial Prediction Filtering of Acoustic Clutter and Random Noise in Medical Ultrasound Imaging.

    Science.gov (United States)

    Shin, Junseob; Huang, Lianjie

    2017-02-01

    One of the major challenges in array-based medical ultrasound imaging is the image quality degradation caused by sidelobes and off-axis clutter, which is an inherent limitation of the conventional delay-and-sum (DAS) beamforming operating on a finite aperture. Ultrasound image quality is further degraded in imaging applications involving strong tissue attenuation and/or low transmit power. In order to effectively suppress acoustic clutter from off-axis targets and random noise in a robust manner, we introduce in this paper a new adaptive filtering technique called frequency-space (F-X) prediction filtering or FXPF, which was first developed in seismic imaging for random noise attenuation. Seismologists developed FXPF based on the fact that linear and quasilinear events or wavefronts in the time-space (T-X) domain are manifested as a superposition of harmonics in the frequency-space (F-X) domain, which can be predicted using an auto-regressive (AR) model. We describe the FXPF technique as a spectral estimation or a direction-of-arrival problem, and explain why adaptation of this technique into medical ultrasound imaging is beneficial. We apply our new technique to simulated and tissue-mimicking phantom data. Our results demonstrate that FXPF achieves CNR improvements of 26% in simulated noise-free anechoic cyst, 109% in simulated anechoic cyst contaminated with random noise of 15 dB SNR, and 93% for experimental anechoic cyst from a custom-made tissue-mimicking phantom. Our findings suggest that FXPF is an effective technique to enhance ultrasound image contrast and has potential to improve the visualization of clinically important anatomical structures and diagnosis of diseased conditions.

  16. High-Fidelity Prediction of Launch Vehicle Liftoff Acoustic Fields Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The high-intensity level acoustic load generated by large launch vehicle lift-off propulsion is of major concern for the integrity of the launch complex and the...

  17. Specific and rapid effects of acoustic stimulation on the tonotopic distribution of Kv3.1b potassium channels in the adult rat.

    Science.gov (United States)

    Strumbos, J G; Polley, D B; Kaczmarek, L K

    2010-05-19

    Recent studies have demonstrated that total cellular levels of voltage-gated potassium channel subunits can change on a time scale of minutes in acute slices and cultured neurons, raising the possibility that rapid changes in the abundance of channel proteins contribute to experience-dependent plasticity in vivo. In order to investigate this possibility, we took advantage of the medial nucleus of the trapezoid body (MNTB) sound localization circuit, which contains neurons that precisely phase-lock their action potentials to rapid temporal fluctuations in the acoustic waveform. Previous work has demonstrated that the ability of these neurons to follow high-frequency stimuli depends critically upon whether they express adequate amounts of the potassium channel subunit Kv3.1. To test the hypothesis that net amounts of Kv3.1 protein would be rapidly upregulated when animals are exposed to sounds that require high frequency firing for accurate encoding, we briefly exposed adult rats to acoustic environments that varied according to carrier frequency and amplitude modulation (AM) rate. Using an antibody directed at the cytoplasmic C-terminus of Kv3.1b (the adult splice isoform of Kv3.1), we found that total cellular levels of Kv3.1b protein-as well as the tonotopic distribution of Kv3.1b-labeled cells-was significantly altered following 30 min of exposure to rapidly modulated (400 Hz) sounds relative to slowly modulated (0-40 Hz, 60 Hz) sounds. These results provide direct evidence that net amounts of Kv3.1b protein can change on a time scale of minutes in response to stimulus-driven synaptic activity, permitting auditory neurons to actively adapt their complement of ion channels to changes in the acoustic environment. Copyright 2010 IBRO. Published by Elsevier Ltd. All rights reserved.

  18. Prediction of nonlinear acoustic propagation effects for high-intensity aerospace noise sources in the natural far-field environment

    Science.gov (United States)

    Lundberg, Wayne Randolph

    A semi-empirical nonlinear aeroacoustic propagation theory was developed for the prediction of high-intensity flight/launch noise produced by full-scale aerospace operations. The resulting nonlinear aeroacoustic propagation model was verified by analysis of environmental noise propagation measurements on the Concorde, United States Air Force F-4C and F-16A aircraft and the Peacekeeper rocket. Propagation modeling of both aeroacoustic directivity and nonlinear attenuation effects were separately verified to be accurate. Model parameters were derived to document the extent of each physical acoustic effect. The parameters of nonlinear acoustic propagation were empirically demonstrated to be linearly related through analysis of multiple sources. These results verified the formulation of a Simplified Nonlinear Aeroacoustic Propagation (SNAP) model. Such verification supports the potential for application of SNAP to broadband aeroacoustic noise source propagation calculations.

  19. Acoustic and optical variations during rapid downward motion episodes in the deep north-western Mediterranean Sea

    CERN Document Server

    van Haren, H; Aguilar, J A; Albert, A; Anghinolfi, M; Anton, G; Anvar, S; Ardid, M; Jesus, A C Assis; Astraatmadja, T; Aubert, J -J; Auer, R; Baret, B; Basa, S; Bazzotti, M; Bertin, V; Biagi, S; Bigongiari, C; Bou-Cabof, M; Bouwhuis, M C; Brown, A; Brunner, J; Busto, J; Camarena, F; Capone, A; Carminati, G; Carr, J; Castel, D; Castorina, E; Cavasinni, V; Cecchini, S; Charvis, Ph; Chiarusi, T; Circella, M; Coniglione, R; Costantini, H; Cottini, N; Coyleh, 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; Flaminio, V; Fratini, K; Fritsch, U; Fuda, J -L; Giacomelli, G; Gómez-González, J P; Graf, K; Guillard, G; Halladjian, G; Hallewell, G; Heijboer, A J; Hello, Y; Hernández-Rey, J J; Hößl, J; de Jong, M; Kalantar-Nayestanakia, N; Kalekin, O; Kappes, A; Katz, U; Kooijman, P; Kopper, C; Kouchner, A; Kretschmer, W; Lahmann, R; Lamare, P; Lambard, G; Laros, G; Laschinsky, H; Lefèvre, D; Lelaizant, G; Lim, G; Presti, D Lo; Loehner, H; Loucatos, S; Lucarelli, F; Lyons, K; Mangano, S; Marcelin, M; Margiotta, A; Martinez-Mora, J A; Maurin, G; Mazure, A; Melissas, M; Montaruli, T; Morganti, M; Moscoso, L; Motz, H; Naumann, C; Neff, M; Ostasch, R; Palioselitis, G; Păvălaş, G E; Payre, P; Petrovic, J; Piattelli, P; Picot-Clemente, N; Picqu, C; Pillet, R; Popa, V; Pradier, T; Presani, E; Racca, C; Radu, A; Reed, C; Riccobene, G; Richardt, C; Rujoiu, M; Russo, G V; Sales, F; Schoeck, F; Schuller, J -P; Shanidze, R; Simeone, F; Spurio, M; Steijger, J J M; Stolarczyk, Th; Tamburini, C; Tasca, L; Toscano, S; Vallage, B; Van Elewyck, V; Vecchi, M; Vernin, P; Wijnker, G; de Wolf, E; Yepes, H; Zaborov, D; Zornoza, J D; Zúñiga, J

    2011-01-01

    An Acoustic Doppler Current Profiler (ADCP) was moored at the deep-sea site of the ANTARES neutrino telescope near Toulon, France, thus providing a unique opportunity to compare high-resolution acoustic and optical observations between 70 and 170 m above the sea bed at 2475 m. The ADCP measured downward vertical currents of magnitudes up to 0.03 m s-1 in late winter and early spring 2006. In the same period, observations were made of enhanced levels of acoustic reflection, interpreted as suspended particles including zooplankton, by a factor of about 10 and of horizontal currents reaching 0.35 m s-1. These observations coincided with high light levels detected by the telescope, interpreted as increased bioluminescence. During winter 2006 deep dense-water formation occurred in the Ligurian subbasin, thus providing a possible explanation for these observations. However, the 10-20 days quasi-periodic episodes of high levels of acoustic reflection, light and large vertical currents continuing into the summer are ...

  20. Interaural Difference of Wave V Predicting Postoperative Hearing in Gardner-Robertson Class II Acoustic Neuroma Patients.

    Science.gov (United States)

    Aihara, Noritaka; Murakami, Shingo; Takemura, Keiji; Yamada, Kazuo

    2013-10-01

    Patients with acoustic neuroma classified in Gardner and Robertson (GR) Class II should be considered to have useful hearing, and patients classified in Class III should be considered to have not-useful hearing. Therefore, it is important for acoustic neuroma surgery to distinguish between postoperative GR Class II and Class III patients by brainstem auditory evoked potentials (BAEPs). We evaluate which BAEP parameter is the best for predicting postoperative GR Class II or III in 36 preoperative GR Class II patients with unilateral acoustic neuroma. Delay in wave V latency, reduction ratio in wave V amplitude, and interaural difference of wave V (IT5) are evaluated by a receiver-operating characteristic (ROC) curve in this study. IT5 is the best distinguishing parameter between postoperative Class II and Class III. IT5 below 1.12 millisecond (msec) should be a good marker to preserve postoperative useful hearing. Thus, comparing the latency of wave V on both sides is important, and surgeons would be able to make more informed decisions during surgery by checking IT5 on BAEPs.

  1. Numerical prediction of combustion induced vibro-acoustical instabilities in a gas turbine combustor

    NARCIS (Netherlands)

    Pozarlik, Artur Krzysztof; Kok, Jacobus B.W.; M. Pawelczyk, D. Bismor

    2009-01-01

    Introduction of lean premixed combustion to gas turbine technology reduced the emission of harmful exhaust gas species, but due to the high sensitivity of lean flames to acoustic perturbations, the average life time of gas turbine engines was decreased significantly. Very dangerous to the integrity

  2. A Frequency-Domain Adaptive Filter (FDAF) Prediction Error Method (PEM) Framework for Double-Talk-Robust Acoustic Echo Cancellation

    DEFF Research Database (Denmark)

    Gil-Cacho, Jose M.; van Waterschoot, Toon; Moonen, Marc

    2014-01-01

    In this paper, we propose a new framework to tackle the double-talk (DT) problem in acoustic echo cancellation (AEC). It is based on a frequency-domain adaptive filter (FDAF) implementation of the so-called prediction error method adaptive filtering using row operations (PEM-AFROW) leading to the...... regularization (VR) algorithms. The FDAF-PEM-AFROW versions significantly outperform the original versions in every simulation. In terms of computational complexity, the FDAF-PEM-AFROW versions are themselves about two orders of magnitude cheaper than the original versions....

  3. Predicting the perceived reverberation in different room acoustic environments using a binaural auditory model.

    Science.gov (United States)

    Osses Vecchi, Alejandro; Kohlrausch, Armin; Lachenmayr, Winfried; Mommertz, Eckard

    2017-04-01

    In this paper a binaural auditory model was used to compute reverberance estimates in four simulated halls. For three of the halls different absorption conditions were evaluated. The model estimates (pRev) were obtained using music excerpts of an orchestra consisting of 23 instrument sections and then compared with the room acoustic parameters of reverberation time (T30) and early decay time (EDT) at mid frequencies. Although the results showed that pRev has a higher correlation with EDT rather than with T30, this relationship depends on the properties of the instruments. The simulations show that pRev depends on the presentation level and that for instruments with similar critical-band spectrum, pRev follows a similar trend across acoustic conditions. A computational framework and sound stimuli are provided to encourage the search of experimental evidence of the aspects addressed in this study.

  4. Low Mach number prediction of the acoustic signature of fractal-generated turbulence

    Energy Technology Data Exchange (ETDEWEB)

    Laizet, Sylvain, E-mail: s.laizet@imperial.ac.uk [Turbulence, Mixing and Flow Control Group, Department of Aeronautics, Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom); Fortune, Veronique, E-mail: veronique.fortune@lea.univ-poitiers.fr [Department of Fluid Flow, Heat Transfer and Combustion, Institute PPRIME, Universite de Poitiers, ENSMA, CNRS, Teleport 2 - Bd. Marie et Pierre Curie, B.P. 30179, 86962 Futuroscope Chasseneuil Cedex (France); Lamballais, Eric, E-mail: lamballais@univ-poitiers.fr [Department of Fluid Flow, Heat Transfer and Combustion, Institute PPRIME, Universite de Poitiers, ENSMA, CNRS, Teleport 2 - Bd. Marie et Pierre Curie, B.P. 30179, 86962 Futuroscope Chasseneuil Cedex (France); Vassilicos, John Christos, E-mail: j.c.vassilicos@imperial.ac.uk [Turbulence, Mixing and Flow Control Group, Department of Aeronautics, Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom)

    2012-06-15

    Highlights: Black-Right-Pointing-Pointer Acoustic properties of a fractal square grid and regular grid. Black-Right-Pointing-Pointer Hybrid approach based on Lighthill's analogy and Direct Numerical Simulation. Black-Right-Pointing-Pointer Noise reduction for the fractal square grid. Black-Right-Pointing-Pointer Well-defined peak at a Strouhal number between 0.2 and 0.3 for the fractal square grid, absent for the regular grid. - Abstract: In this work, we compare the acoustic properties of a fractal square grid with those of a regular grid by means of a hybrid approach based on Lighthill's analogy and Direct Numerical Simulation (DNS). Our results show that the sound levels corresponding to our fractal square grid of three fractal iterations are significantly reduced by comparison to a regular grid of same porosity and mesh-based Reynolds number. We also find a well-defined peak at a Strouhal number between 0.2 and 0.3 in the acoustic spectrum of our fractal square grid which is absent in the case of our regular grid. We explain this effect in terms of a new criterion for quasi-periodic vortex shedding from a regular or fractal grid.

  5. An integrated Gaussian process regression for prediction of remaining useful life of slow speed bearings based on acoustic emission

    Science.gov (United States)

    Aye, S. A.; Heyns, P. S.

    2017-02-01

    This paper proposes an optimal Gaussian process regression (GPR) for the prediction of remaining useful life (RUL) of slow speed bearings based on a novel degradation assessment index obtained from acoustic emission signal. The optimal GPR is obtained from an integration or combination of existing simple mean and covariance functions in order to capture the observed trend of the bearing degradation as well the irregularities in the data. The resulting integrated GPR model provides an excellent fit to the data and improves over the simple GPR models that are based on simple mean and covariance functions. In addition, it achieves a low percentage error prediction of the remaining useful life of slow speed bearings. These findings are robust under varying operating conditions such as loading and speed and can be applied to nonlinear and nonstationary machine response signals useful for effective preventive machine maintenance purposes.

  6. Prediction of Class II improvement after rapid maxillary expansion in early mixed dentition

    Directory of Open Access Journals (Sweden)

    Alberto Caprioglio

    2017-04-01

    Full Text Available Abstract Background The aim of this study is to identify cephalometric pretreatment parameters for prediction of Class II improvement induced by rapid maxillary expansion. Methods Lateral cephalograms of 30 patients (mean age 8.3 ± 1.6 years old showing Class II molar relationship and undergone to rapid maxillary expansion on the upper deciduous molars were traced before treatment, and molar relation changes were evaluated on dental casts before and after treatment. Overall treatment time lasted 10.2 ± 2 months. Good responders (18 subjects, 10 females and 8 males showed improvement of at least 2.50 mm, and bad responders (12 subjects, 7 females and 5 males showed no improvement, improvement less than 2.50 mm, or worsening of molar relationship after treatment. Student’s t test was used to assess significance of differences between groups, and discriminant analysis allowed identification of predictive pretreatment variables. Results Articular angle, superior gonial angle, and mandibular dimensions (Co-Gn, S-Ar, Ar-Go, Go-Me showed significant differences in the comparison between groups. Mandibular length Co-Gn and superior gonial angle were selected as significant predictive variable for discrimination. Conclusions Patients with smaller mandibular length and more acute superior gonial angle are expected to have more chances to improve molar Class II after rapid maxillary expansion.

  7. Rapid prediction of long-term rates of contaminant desorption from soils and sediments.

    Science.gov (United States)

    Johnson, M D; Weber, W J

    2001-01-15

    A method using heated and superheated (subcritical) water is described for rapid prediction of long-term desorption rates from contaminated geosorbents. Rates of contaminant release are measured at temperatures between 75 and 150 degrees C using a dynamic water desorption technique. The subcritical desorption rate data are then modeled to calculate apparent activation energies, and these activation energies are used to predict desorption behaviors at any desired ambient temperature. Predictions of long-term release rates based on this methodology were found to correlate well with experimental 25 degrees C desorption data measured over periods of up to 640 days, even though the 25 degrees C desorption rates were observed to vary by up to 2 orders of magnitude for different geosorbent types and initial solid phase contaminant loading levels. Desorption profiles measured under elevated temperature and pressure conditions closely matched those at 25 degrees C and ambient pressure, but the time scales associated with the high-temperature measurements were up to 3 orders of magnitude lower. The subcritical water technique rapidly estimates rates of desorption-resistant contaminant release as well as those for more labile substances. The practical implications of the methodology are significant because desorption observed under field conditions and ambient temperatures typically proceeds over periods of months or years, while the high temperature experiments used for prediction of such field desorption phenomena can be completed within periods of only hours or days.

  8. Predicting stem borer density in maize using RapidEye data and generalized linear models

    Science.gov (United States)

    Abdel-Rahman, Elfatih M.; Landmann, Tobias; Kyalo, Richard; Ong'amo, George; Mwalusepo, Sizah; Sulieman, Saad; Ru, Bruno Le

    2017-05-01

    Average maize yield in eastern Africa is 2.03 t ha-1 as compared to global average of 6.06 t ha-1 due to biotic and abiotic constraints. Amongst the biotic production constraints in Africa, stem borers are the most injurious. In eastern Africa, maize yield losses due to stem borers are currently estimated between 12% and 21% of the total production. The objective of the present study was to explore the possibility of RapidEye spectral data to assess stem borer larva densities in maize fields in two study sites in Kenya. RapidEye images were acquired for the Bomet (western Kenya) test site on the 9th of December 2014 and on 27th of January 2015, and for Machakos (eastern Kenya) a RapidEye image was acquired on the 3rd of January 2015. Five RapidEye spectral bands as well as 30 spectral vegetation indices (SVIs) were utilized to predict per field maize stem borer larva densities using generalized linear models (GLMs), assuming Poisson ('Po') and negative binomial ('NB') distributions. Root mean square error (RMSE) and ratio prediction to deviation (RPD) statistics were used to assess the models performance using a leave-one-out cross-validation approach. The Zero-inflated NB ('ZINB') models outperformed the 'NB' models and stem borer larva densities could only be predicted during the mid growing season in December and early January in both study sites, respectively (RMSE = 0.69-1.06 and RPD = 8.25-19.57). Overall, all models performed similar when all the 30 SVIs (non-nested) and only the significant (nested) SVIs were used. The models developed could improve decision making regarding controlling maize stem borers within integrated pest management (IPM) interventions.

  9. Disrupted rapid eye movement sleep predicts poor declarative memory performance in post-traumatic stress disorder.

    Science.gov (United States)

    Lipinska, Malgorzata; Timol, Ridwana; Kaminer, Debra; Thomas, Kevin G F

    2014-06-01

    Successful memory consolidation during sleep depends on healthy slow-wave and rapid eye movement sleep, and on successful transition across sleep stages. In post-traumatic stress disorder, sleep is disrupted and memory is impaired, but relations between these two variables in the psychiatric condition remain unexplored. We examined whether disrupted sleep, and consequent disrupted memory consolidation, is a mechanism underlying declarative memory deficits in post-traumatic stress disorder. We recruited three matched groups of participants: post-traumatic stress disorder (n = 16); trauma-exposed non-post-traumatic stress disorder (n = 15); and healthy control (n = 14). They completed memory tasks before and after 8 h of sleep. We measured sleep variables using sleep-adapted electroencephalography. Post-traumatic stress disorder-diagnosed participants experienced significantly less sleep efficiency and rapid eye movement sleep percentage, and experienced more awakenings and wake percentage in the second half of the night than did participants in the other two groups. After sleep, post-traumatic stress disorder-diagnosed participants retained significantly less information on a declarative memory task than controls. Rapid eye movement percentage, wake percentage and sleep efficiency correlated with retention of information over the night. Furthermore, lower rapid eye movement percentage predicted poorer retention in post-traumatic stress disorder-diagnosed individuals. Our results suggest that declarative memory consolidation is disrupted during sleep in post-traumatic stress disorder. These data are consistent with theories suggesting that sleep benefits memory consolidation via predictable neurobiological mechanisms, and that rapid eye movement disruption is more than a symptom of post-traumatic stress disorder. © 2014 European Sleep Research Society.

  10. HIGH-PRECISION PREDICTIONS FOR THE ACOUSTIC SCALE IN THE NONLINEAR REGIME

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Hee-Jong; Eckel, Jonathan; Eisenstein, Daniel J.; Mehta, Kushal; Metchnik, Marc; Padmanabhan, Nikhil; Pinto, Phillip; Takahashi, Ryuichi; White, Martin; Xu, Xiaoying

    2010-09-10

    We measure shifts of the acoustic scale due to nonlinear growth and redshift distortions to a high precision using a very large volume of high-force-resolution simulations. We compare results from various sets of simulations that differ in their force, volume, and mass resolution. We find a consistency within 1.5-sigma for shift values from different simulations and derive shift alpha(z) -1 = (0.300\\pm 0.015)% [D(z)/D(0)]^{2} using our fiducial set. We find a strong correlation with a non-unity slope between shifts in real space and in redshift space and a weak correlation between the initial redshift and low redshift. Density-field reconstruction not only removes the mean shifts and reduces errors on the mean, but also tightens the correlations: after reconstruction, we recover a slope of near unity for the correlation between the real and redshift space and restore a strong correlation between the low and the initial redshifts. We derive propagators and mode-coupling terms from our N-body simulations and compared with Zeldovich approximation and the shifts measured from the chi^2 fitting, respectively. We interpret the propagator and the mode-coupling term of a nonlinear density field in the context of an average and a dispersion of its complex Fourier coefficients relative to those of the linear density field; from these two terms, we derive a signal-to-noise ratio of the acoustic peak measurement. We attempt to improve our reconstruction method by implementing 2LPT and iterative operations: we obtain little improvement. The Fisher matrix estimates of uncertainty in the acoustic scale is tested using 5000 (Gpc/h)^3 of cosmological PM simulations from Takahashi et al. (2009). (abridged)

  11. A finite element model to predict the sound attenuation of earplugs in an acoustical test fixture.

    Science.gov (United States)

    Viallet, Guilhem; Sgard, Franck; Laville, Frédéric; Boutin, Jérôme

    2014-09-01

    Acoustical test fixtures (ATFs) are currently used to measure the attenuation of the earplugs. Several authors pointed out that the presence of an artificial skin layer inside the cylindrical ear canal of the ATFs strongly influenced the attenuation measurements. In this paper, this role is investigated via a 2D axisymmetric finite element model of a silicon earplug coupled to an artificial skin. The model is solved using COMSOL Multiphysics (COMSOL(®), Sweden) and validated experimentally. The model is exploited thereafter to better understand the role of each part of the earplug/ear canal system and how the energy circulates within the domains. This is investigated by calculating power balances and by representing the mechanical and acoustical fluxes in the system. The important dissipative role of the artificial skin is underlined and its contribution as a sound transmission pathway is quantified. In addition, the influence of both the earplug and the artificial skin parameters is assessed via sensitivities analyses performed on the model.

  12. Rapid Generation of Multiplexed Cell Cocultures Using Acoustic Droplet Ejection Followed by Aqueous Two-Phase Exclusion Patterning

    Science.gov (United States)

    Fang, Yu; Frampton, John P.; Raghavan, Shreya; Sabahi-Kaviani, Rahman; Luker, Gary

    2012-01-01

    The development of tools for patterning cocultures of cells is a fundamental interest among cell biologists and tissue engineers. Although a variety of systems exist for micropatterning cells, the methods used to generate cell micropatterns are often cumbersome and difficult to adapt for tissue engineering purposes. This study combines acoustic droplet ejection and aqueous two-phase system exclusion patterning to introduce a method for patterning cocultures of cells in multiplexed arrays. This new method uses focused acoustic radiation pressure to eject discrete droplets of uniform size from the surface of a dextran solution containing cells. The size of droplets is controlled by adjusting ultrasound parameters, such as pulse, duration, and amplitude. The ejected dextran droplets are captured on a cell culture substrate that is manipulated by a computer-controlled 3D positioning system according to predesigned patterns. Polyethylene glycol solution containing an additional cell type is then added to the culture dish to produce a two-phase system capable of depositing different types of cells around the initial pattern of cells. We demonstrate that our method can produce patterns of islands or lines with two or more cell types. Further, we demonstrate that patterns can be multiplexed for studies involving combinations of multiple cell types. This method offers a tool to transfer cell-containing samples in a contact-free, nozzle-less manner, avoiding sample cross-contamination. It can be used to pattern cell cocultures without complicated fabrication of culture substrates. These capabilities were used to examine the response of cancer cells to the presence of a ligand (CXCL12) secreted from surrounding cocultured cells. PMID:22356298

  13. Rapid Prediction of Moisture Content in Intact Green Coffee Beans Using Near Infrared Spectroscopy.

    Science.gov (United States)

    Adnan, Adnan; Hörsten, Dieter von; Pawelzik, Elke; Mörlein, And Daniel

    2017-05-19

    Moisture content (MC) is one of the most important quality parameters of green coffee beans. Therefore, its fast and reliable measurement is necessary. This study evaluated the feasibility of near infrared (NIR) spectroscopy and chemometrics for rapid and non-destructive prediction of MC in intact green coffee beans of both Coffea arabica (Arabica) and Coffea canephora (Robusta) species. Diffuse reflectance (log 1/R) spectra of intact beans were acquired using a bench top Fourier transform NIR instrument. MC was determined gravimetrically according to The International Organization for Standardization (ISO) 6673. Samples were split into subsets for calibration ( n = 64) and independent validation ( n = 44). A three-component partial least squares regression (PLSR) model using raw NIR spectra yielded a root mean square error of prediction (RMSEP) of 0.80% MC; a four component PLSR model using scatter corrected spectra yielded a RMSEP of 0.57% MC. A simplified PLS model using seven selected wavelengths (1155, 1212, 1340, 1409, 1724, 1908, and 2249 nm) yielded a similar accuracy (RMSEP: 0.77% MC) which opens the possibility of creating cheaper NIR instruments. In conclusion, NIR diffuse reflectance spectroscopy appears to be suitable for rapid and reliable MC prediction in intact green coffee; no separate model for Arabica and Robusta species is needed.

  14. Coral mass spawning predicted by rapid seasonal rise in ocean temperature

    KAUST Repository

    Keith, Sally A.

    2016-05-11

    Coral spawning times have been linked to multiple environmental factors; however, to what extent these factors act as generalized cues across multiple species and large spatial scales is unknown. We used a unique dataset of coral spawning from 34 reefs in the Indian and Pacific Oceans to test if month of spawning and peak spawning month in assemblages of Acropora spp. can be predicted by sea surface temperature (SST), photosynthetically available radiation, wind speed, current speed, rainfall or sunset time. Contrary to the classic view that high mean SST initiates coral spawning, we found rapid increases in SST to be the best predictor in both cases (month of spawning: R2 = 0.73, peak: R2 = 0.62). Our findings suggest that a rapid increase in SST provides the dominant proximate cue for coral mass spawning over large geographical scales. We hypothesize that coral spawning is ultimately timed to ensure optimal fertilization success.

  15. Prediction of the Strain Response of Poly-AlN/(100Si Surface Acoustic Wave Resonator and Experimental Analysis

    Directory of Open Access Journals (Sweden)

    Shuo Chen

    2016-04-01

    Full Text Available The strain sensitivity of the Aluminum Nitride (AlN/Silicon (Si surface acoustic wave resonator (SAWR is predicted based on a modeling method introduced in this work, and further compared with experimental results. The strain influence on both the period of the inter-digital transducer (IDT and the sound velocity is taken into consideration when modeling the strain response. From the modeling results, AlN and Si have opposite responses to strain; hence, for the AlN/Si-based SAWR, both a positive and a negative strain coefficient factor can be achieved by changing the thickness of the AlN layer, which is confirmed by strain response testing based on a silicon cantilever structure with two AlN configurations (1 μm and 3 μm in thickness, respectively.

  16. Prediction of the Strain Response of Poly-AlN/(100)Si Surface Acoustic Wave Resonator and Experimental Analysis.

    Science.gov (United States)

    Chen, Shuo; You, Zheng

    2016-04-27

    The strain sensitivity of the Aluminum Nitride (AlN)/Silicon (Si) surface acoustic wave resonator (SAWR) is predicted based on a modeling method introduced in this work, and further compared with experimental results. The strain influence on both the period of the inter-digital transducer (IDT) and the sound velocity is taken into consideration when modeling the strain response. From the modeling results, AlN and Si have opposite responses to strain; hence, for the AlN/Si-based SAWR, both a positive and a negative strain coefficient factor can be achieved by changing the thickness of the AlN layer, which is confirmed by strain response testing based on a silicon cantilever structure with two AlN configurations (1 μm and 3 μm in thickness, respectively).

  17. Impacts of Earth rotation parameters on GNSS ultra-rapid orbit prediction: Derivation and real-time correction

    Science.gov (United States)

    Wang, Qianxin; Hu, Chao; Xu, Tianhe; Chang, Guobin; Hernández Moraleda, Alberto

    2017-12-01

    Analysis centers (ACs) for global navigation satellite systems (GNSSs) cannot accurately obtain real-time Earth rotation parameters (ERPs). Thus, the prediction of ultra-rapid orbits in the international terrestrial reference system (ITRS) has to utilize the predicted ERPs issued by the International Earth Rotation and Reference Systems Service (IERS) or the International GNSS Service (IGS). In this study, the accuracy of ERPs predicted by IERS and IGS is analyzed. The error of the ERPs predicted for one day can reach 0.15 mas and 0.053 ms in polar motion and UT1-UTC direction, respectively. Then, the impact of ERP errors on ultra-rapid orbit prediction by GNSS is studied. The methods for orbit integration and frame transformation in orbit prediction with introduced ERP errors dominate the accuracy of the predicted orbit. Experimental results show that the transformation from the geocentric celestial references system (GCRS) to ITRS exerts the strongest effect on the accuracy of the predicted ultra-rapid orbit. To obtain the most accurate predicted ultra-rapid orbit, a corresponding real-time orbit correction method is developed. First, orbits without ERP-related errors are predicted on the basis of ITRS observed part of ultra-rapid orbit for use as reference. Then, the corresponding predicted orbit is transformed from GCRS to ITRS to adjust for the predicted ERPs. Finally, the corrected ERPs with error slopes are re-introduced to correct the predicted orbit in ITRS. To validate the proposed method, three experimental schemes are designed: function extrapolation, simulation experiments, and experiments with predicted ultra-rapid orbits and international GNSS Monitoring and Assessment System (iGMAS) products. Experimental results show that using the proposed correction method with IERS products considerably improved the accuracy of ultra-rapid orbit prediction (except the geosynchronous BeiDou orbits). The accuracy of orbit prediction is enhanced by at least 50

  18. Rapid changes in brain structure predict improvements induced by perceptual learning.

    Science.gov (United States)

    Ditye, Thomas; Kanai, Ryota; Bahrami, Bahador; Muggleton, Neil G; Rees, Geraint; Walsh, Vincent

    2013-11-01

    Practice-dependent changes in brain structure can occur in task relevant brain regions as a result of extensive training in complex motor tasks and long-term cognitive training but little is known about the impact of visual perceptual learning on brain structure. Here we studied the effect of five days of visual perceptual learning in a motion-color conjunction search task using anatomical MRI. We found rapid changes in gray matter volume in the right posterior superior temporal sulcus, an area sensitive to coherently moving stimuli, that predicted the degree to which an individual's performance improved with training. Furthermore, behavioral improvements were also predicted by volumetric changes in an extended white matter region underlying the visual cortex. These findings point towards quick and efficient plastic neural mechanisms that enable the visual brain to deal effectively with changing environmental demands. Copyright © 2013 Elsevier Inc. All rights reserved.

  19. AST Launch Vehicle Acoustics

    Science.gov (United States)

    Houston, Janice; Counter, D.; Giacomoni, D.

    2015-01-01

    The liftoff phase induces acoustic loading over a broad frequency range for a launch vehicle. These external acoustic environments are then used in the prediction of internal vibration responses of the vehicle and components which result in the qualification levels. Thus, predicting these liftoff acoustic (LOA) environments is critical to the design requirements of any launch vehicle. If there is a significant amount of uncertainty in the predictions or if acoustic mitigation options must be implemented, a subscale acoustic test is a feasible pre-launch test option to verify the LOA environments. The NASA Space Launch System (SLS) program initiated the Scale Model Acoustic Test (SMAT) to verify the predicted SLS LOA environments and to determine the acoustic reduction with an above deck water sound suppression system. The SMAT was conducted at Marshall Space Flight Center and the test article included a 5% scale SLS vehicle model, tower and Mobile Launcher. Acoustic and pressure data were measured by approximately 250 instruments. The SMAT liftoff acoustic results are presented, findings are discussed and a comparison is shown to the Ares I Scale Model Acoustic Test (ASMAT) results.

  20. Use of predictive models and rapid methods to nowcast bacteria levels at coastal beaches

    Science.gov (United States)

    Francy, Donna S.

    2009-01-01

    The need for rapid assessments of recreational water quality to better protect public health is well accepted throughout the research and regulatory communities. Rapid analytical methods, such as quantitative polymerase chain reaction (qPCR) and immunomagnetic separation/adenosine triphosphate (ATP) analysis, are being tested but are not yet ready for widespread use.Another solution is the use of predictive models, wherein variable(s) that are easily and quickly measured are surrogates for concentrations of fecal-indicator bacteria. Rainfall-based alerts, the simplest type of model, have been used by several communities for a number of years. Deterministic models use mathematical representations of the processes that affect bacteria concentrations; this type of model is being used for beach-closure decisions at one location in the USA. Multivariable statistical models are being developed and tested in many areas of the USA; however, they are only used in three areas of the Great Lakes to aid in notifications of beach advisories or closings. These “operational” statistical models can result in more accurate assessments of recreational water quality than use of the previous day's Escherichia coli (E. coli)concentration as determined by traditional culture methods. The Ohio Nowcast, at Huntington Beach, Bay Village, Ohio, is described in this paper as an example of an operational statistical model. Because predictive modeling is a dynamic process, water-resource managers continue to collect additional data to improve the predictive ability of the nowcast and expand the nowcast to other Ohio beaches and a recreational river. Although predictive models have been shown to work well at some beaches and are becoming more widely accepted, implementation in many areas is limited by funding, lack of coordinated technical leadership, and lack of supporting epidemiological data.

  1. How we learn to make decisions: rapid propagation of reinforcement learning prediction errors in humans.

    Science.gov (United States)

    Krigolson, Olav E; Hassall, Cameron D; Handy, Todd C

    2014-03-01

    Our ability to make decisions is predicated upon our knowledge of the outcomes of the actions available to us. Reinforcement learning theory posits that actions followed by a reward or punishment acquire value through the computation of prediction errors-discrepancies between the predicted and the actual reward. A multitude of neuroimaging studies have demonstrated that rewards and punishments evoke neural responses that appear to reflect reinforcement learning prediction errors [e.g., Krigolson, O. E., Pierce, L. J., Holroyd, C. B., & Tanaka, J. W. Learning to become an expert: Reinforcement learning and the acquisition of perceptual expertise. Journal of Cognitive Neuroscience, 21, 1833-1840, 2009; Bayer, H. M., & Glimcher, P. W. Midbrain dopamine neurons encode a quantitative reward prediction error signal. Neuron, 47, 129-141, 2005; O'Doherty, J. P. Reward representations and reward-related learning in the human brain: Insights from neuroimaging. Current Opinion in Neurobiology, 14, 769-776, 2004; Holroyd, C. B., & Coles, M. G. H. The neural basis of human error processing: Reinforcement learning, dopamine, and the error-related negativity. Psychological Review, 109, 679-709, 2002]. Here, we used the brain ERP technique to demonstrate that not only do rewards elicit a neural response akin to a prediction error but also that this signal rapidly diminished and propagated to the time of choice presentation with learning. Specifically, in a simple, learnable gambling task, we show that novel rewards elicited a feedback error-related negativity that rapidly decreased in amplitude with learning. Furthermore, we demonstrate the existence of a reward positivity at choice presentation, a previously unreported ERP component that has a similar timing and topography as the feedback error-related negativity that increased in amplitude with learning. The pattern of results we observed mirrored the output of a computational model that we implemented to compute reward

  2. Dynamic monitoring and prediction of Dianchi Lake cyanobacteria outbreaks in the context of rapid urbanization.

    Science.gov (United States)

    Luo, Yi; Yang, Kun; Yu, Zhenyu; Chen, Junyi; Xu, Yufei; Zhou, Xiaolu; Yang, Yang

    2017-02-01

    Water crises have been among the most serious environmental problems worldwide since the twenty-first century. A water crisis is marked by a severe shortage of water resources and deteriorating water quality. As an important component of water resources, lake water quality has deteriorated rapidly in the context of fast urbanization and climate change. This deterioration has altered the water ecosystem structure and influenced lake functionality. To curb these trends, various strategies and procedures have been used in many urban lakes. Among these procedures, accurate and responsive water environment monitoring is the basis of the forecasting and prevention of large-scale cyanobacteria outbreaks and improvement of water quality. To dynamically monitor and predict the outbreak of cyanobacteria in Dianchi Lake, in this study, wireless sensors networks (WSNs) and the geographic information system (GIS) are used to monitor water quality at the macro-scale and meso-scale. Historical, real-time water quality and weather condition data were collected, and a combination prediction model (adaptive grey model (AGM) and back propagation artificial neural network (BPANN)) was proposed. The correlation coefficient (R) of the simulation experiment reached 0.995. Moreover, we conducted an empirical experiment in Dianchi Lake, Yunnan, China using the proposed method. R was 0.93, and the predicting error was 4.77. The results of the experiment suggest that our model has good performance for water quality prediction and can forecast cyanobacteria outbreaks. This system provides responsive forewarning and data support for lake protection and pollution control.

  3. Comparison of Ultra-Rapid Orbit Prediction Strategies for GPS, GLONASS, Galileo and BeiDou.

    Science.gov (United States)

    Geng, Tao; Zhang, Peng; Wang, Wei; Xie, Xin

    2018-02-06

    Currently, ultra-rapid orbits play an important role in the high-speed development of global navigation satellite system (GNSS) real-time applications. This contribution focuses on the impact of the fitting arc length of observed orbits and solar radiation pressure (SRP) on the orbit prediction performance for GPS, GLONASS, Galileo and BeiDou. One full year's precise ephemerides during 2015 were used as fitted observed orbits and then as references to be compared with predicted orbits, together with known earth rotation parameters. The full nine-parameter Empirical Center for Orbit Determination in Europe (CODE) Orbit Model (ECOM) and its reduced version were chosen in our study. The arc lengths of observed fitted orbits that showed the smallest weighted root mean squares (WRMSs) and medians of the orbit differences after a Helmert transformation fell between 40 and 45 h for GPS and GLONASS and between 42 and 48 h for Galileo, while the WRMS values and medians become flat after a 42 h arc length for BeiDou. The stability of the Helmert transformation and SRP parameters also confirmed the similar optimal arc lengths. The range around 42-45 h is suggested to be the optimal arc length interval of the fitted observed orbits for the multi-GNSS joint solution of ultra-rapid orbits.

  4. Rapid in situ assessment for predicting soil quality using an algae-soaked disc seeding assay.

    Science.gov (United States)

    Nam, Sun-Hwa; Moon, Jongmin; Kim, Shin Woong; Kim, Hakyeong; Jeong, Seung-Woo; An, Youn-Joo

    2017-11-16

    The soil quality of remediated land is altered and this land consequently exerts unexpected biological effects on terrestrial organisms. Therefore, field evaluation of such land should be conducted using biological indicators. Algae are a promising new biological indicator since they are a food source for organisms in higher soil trophic levels and easily sampled from the soil. Field evaluation of soil characteristics is preferred to be testing in laboratory conditions because many biological effects cannot be duplicated during laboratory evaluations. Herein, we describe a convenient and rapid algae-soaked disc seeding assay for assessing soil quality in the field based on soil algae. The collection of algae is easy and rapid and the method predicts the short-term quality of contaminated, remediated, and amended farm and paddy soils. The algae-soaked disc seeding assay is yet to be extensively evaluated, and the method cannot be applied to loamy sand soil in in situ evaluations. The algae-soaked disc seeding assay is recommended for prediction of soil quality in in situ evaluations because it reflects all variations in the environment. The algae-soaked disc seeding assay will help to develop management strategies for in situ evaluation.

  5. Can acoustic radiation force impulse elastography be a substitute for liver biopsy in predicting liver fibrosis?

    Science.gov (United States)

    Jain, V; Dixit, R; Chowdhury, V; Puri, A S; Gondal, R

    2016-09-01

    To evaluate the clinical feasibility and accuracy of acoustic radiation force impulse (ARFI) elastography for the detection of liver fibrosis in patients with chronic viral hepatitis. ARFI-based ultrasound elastography was performed in 69 patients with chronic liver disease (CLD) of viral aetiology and 36 healthy volunteers. Fifty-eight patients with CLD also underwent liver biopsy. ARFI was feasible in all 36 healthy volunteers and all 69 CLD patients, while valid measurements were obtained in 65 patients (95.6%) and all healthy volunteers. The mean shear-wave velocity (SWV) in healthy volunteers was 1.12±0.2 m/s. A gradual increase in mean SWV was noted from fibrosis of Grade F0 to F6 (Ishak's score) and a high positive correlation was found between the mean SWV on ARFI and fibrosis scores at liver biopsy (rho=0.789). The difference between the mild (F1 and F2) versus significant fibrosis (F3 and F4) was also statistically significant (pliver stiffness and may help to distinguish between no/mild fibrosis and significant fibrosis and guide management decisions. Copyright © 2016 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  6. Low power underwater acoustic DPSK detection: Theoretical prediction and experimental results

    Science.gov (United States)

    Dunne, Andrew

    This thesis presents two methods of analyzing the effectiveness of a prototype differential phase-shift keying (DPSK) detection circuit. The first method is to make modifications to the existing hardware to reliably output and record the cross-correlation values of the DPSK detection process. The second method is to write a MATLAB detection algorithm which accurately simulates the detection results of the hardware system without the need of any electronics. These two systems were tested and verified with a bench test using computer generated DPSK signals. The hardware system was tested using real acoustic data from shallow and deep water at-sea tests to determine the effectiveness of the DPSK detection circuit in different ocean environments. The hydrophone signals from the tests were recorded so that the cross-correlation values could be verified using the MATLAB detector. As a result of this study, these two systems provided more insight into how well the DPSK detection prototype works and helped to identify ways of improving the detection reliability and overall performance of the prototype DPSK detection circuit.

  7. Predictive Value of Kushida Index and Acoustic Pharyngometry for the Evaluation of Upper Airway in Subjects With or Without Obstructive Sleep Apnea

    Science.gov (United States)

    Cho, Hae Young; Grunstein, Ronald R; Yee, Brendon

    2004-01-01

    Acoustic pharyngometry is a relatively new noninvasive method that quantifies geometrically complexed pharyngeal dimensions. Our study aimed to investigate the predictability and usefulness of acoustic pharyngometry in diagnosis of obstructive sleep apnea (OSA), and we developed a prospective clinical trial in 16 subjects without apnea and 54 subjects with apnea. All seventy subjects received polysomnography (PSG) to assess the sleep architecture, including breathing and the degree of apnea hypopnea index. Acoustic pharyngometry was performed in four body positions (sitting, supine, right and left lateral) while awake with tidal breathing in addition to morphometric measurements (Kushida index) of oral cavity. This study shows that the cross-sectional area and volume of the upper airway is smaller in the supine position than any other positions. As well, the oropharyngeal junction area of the supine position is the most predictive parameter to discriminate between subjects with or without OSA. Acoustic pharyngometry can be a clinically useful tool for localizing the narrowed portion of the upper airway and predicting obstructive sleep apnea. PMID:15483340

  8. 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...

  9. Incorporating Realistic Acoustic Propagation Models in Simulation of Underwater Acoustic Networks: A Statistical Approach

    National Research Council Canada - National Science Library

    Xie, Geoffrey; Gibson, John; Diaz-Gonzalez, Leopoldo

    2006-01-01

    .... The validity of the simulation results becomes questionable. There are, though, very high fidelity models developed by acoustic engineers and physicists for predicting acoustic propagation characteristics...

  10. Design of deep convolutional networks for prediction of image rapid serial visual presentation events.

    Science.gov (United States)

    Zijing Mao; Wan Xiang Yao; Yufe Huang

    2017-07-01

    We report in this paper an investigation of convolutional neural network (CNN) models for target prediction in time-locked image rapid serial visual presentation (RSVP) experiment. We investigated CNN models with 11 different designs of convolution filters in capturing spatial and temporal correlations in EEG data. We showed that for both within-subject and cross-subject predictions, the CNN models outperform the state-of-the-art algorithms: Bayesian linear discriminant analysis (BLDA) and xDAWN spatial filtering and achieved >6% improvement. Among the 11 different CNN models, the global spatial filter and our proposed region of interest (ROI) achieved best performance. We also implemented the deconvolution network to show how we can visualize from activated hidden units for target/nontarget events learned by the ROI-CNN. Our study suggests that deep learning is a powerful tool for RSVP target prediction and the proposed model is applicable for general EEG-based classifications in brain computer interaction research. The code of this project is available at https://github.com/ZijingMao/ROICNN.

  11. Acoustic Log Prediction on the Basis of Kernel Extreme Learning Machine for Wells in GJH Survey, Erdos Basin

    Directory of Open Access Journals (Sweden)

    Jianhua Cao

    2017-01-01

    Full Text Available In petroleum exploration, the acoustic log (DT is popularly used as an estimator to calculate formation porosity, to carry out petrophysical studies, or to participate in geological analysis and research (e.g., to map abnormal pore-fluid pressure. But sometime it does not exist in those old wells drilled 20 years ago, either because of data loss or because of just being not recorded at that time. Thus synthesizing the DT log becomes the necessary task for the researchers. In this paper we propose using kernel extreme learning machine (KELM to predict missing sonic (DT logs when only common logs (e.g., natural gamma ray: GR, deep resistivity: REID, and bulk density: DEN are available. The common logs are set as predictors and the DT log is the target. By using KELM, a prediction model is firstly created based on the experimental data and then confirmed and validated by blind-testing the results in wells containing both the predictors and the target (DT values used in the supervised training. Finally the optimal model is set up as a predictor. A case study for wells in GJH survey from the Erdos Basin, about velocity inversion using the KELM-estimated DT values, is presented. The results are promising and encouraging.

  12. Analysis of Acoustic Modeling and Sound Propagation in Aircraft Noise Prediction

    Science.gov (United States)

    Plotkin, Kenneth J.; Shepherd, Kevin P. (Technical Monitor)

    2006-01-01

    An analysis has been performed of measured and predicted aircraft noise levels around Denver International Airport. A detailed examination was made of 90 straight-out departures that yielded good measurements on multiple monitors. Predictions were made with INM 5, INM 6 and the simulation model NMSIM. Predictions were consistently lower than measurements, less so for the simulation model than for the integrated models. Lateral directivity ("installation effect") patterns were seen which are consistent with other recent measurements. Atmospheric absorption was determined to be a significant factor in the underprediction. Calculations of atmospheric attenuation were made over a full year of upper air data at seven locations across the United States. It was found that temperature/humidity effects could cause variations of up to +/-4 dB, depending on season, for the sites examined. It was concluded that local temperature and humidity should be accounted for in aircraft noise modeling.

  13. Predicting Airport Screening Officers' Visual Search Competency With a Rapid Assessment.

    Science.gov (United States)

    Mitroff, Stephen R; Ericson, Justin M; Sharpe, Benjamin

    2017-11-01

    Objective The study's objective was to assess a new personnel selection and assessment tool for aviation security screeners. A mobile app was modified to create a tool, and the question was whether it could predict professional screeners' on-job performance. Background A variety of professions (airport security, radiology, the military, etc.) rely on visual search performance-being able to detect targets. Given the importance of such professions, it is necessary to maximize performance, and one means to do so is to select individuals who excel at visual search. A critical question is whether it is possible to predict search competency within a professional search environment. Method Professional searchers from the USA Transportation Security Administration (TSA) completed a rapid assessment on a tablet-based X-ray simulator (XRAY Screener, derived from the mobile technology app Airport Scanner; Kedlin Company). The assessment contained 72 trials that were simulated X-ray images of bags. Participants searched for prohibited items and tapped on them with their finger. Results Performance on the assessment significantly related to on-job performance measures for the TSA officers such that those who were better XRAY Screener performers were both more accurate and faster at the actual airport checkpoint. Conclusion XRAY Screener successfully predicted on-job performance for professional aviation security officers. While questions remain about the underlying cognitive mechanisms, this quick assessment was found to significantly predict on-job success for a task that relies on visual search performance. Application It may be possible to quickly assess an individual's visual search competency, which could help organizations select new hires and assess their current workforce.

  14. Rapid near infrared spectroscopy for prediction of enzymatic hydrolysis of corn bran after various pretreatments

    DEFF Research Database (Denmark)

    Baum, Andreas; Wittrup Agger, Jane; Meyer, Anne S.

    2012-01-01

    step is to increase the responsivity of the substrate to enzymatic attack and the type of pretreatment affects the enzymatic conversion efficiency. Destarched corn bran is a fibrous, heteroxylan-rich side-stream from the starch industry which may be used as a feedstock for bioethanol production...... or as a source of xylose for other purposes. In the present study we demonstrate the use of diffuse reflectance near infrared spectroscopy (NIR) as a rapid and non-destructive analytical tool for evaluation of pretreatment effects on destarched corn bran. NIR was used to achieve classification between 43...... differently pretreated corn bran samples using principal component analysis (PCA) and hierarchal clustering algorithms. Quantification of the enzymatically released monosaccharides by HPLC was used to design multivariate calibration models (biPLS) on the NIR spectra. The models could predict the enzymatic...

  15. The influence of profiled ceilings on sports hall acoustics : Ground effect predictions and scale model measurements

    NARCIS (Netherlands)

    Wattez, Y.C.M.; Tenpierik, M.J.; Nijs, L.

    2018-01-01

    Over the last few years, reverberation times and sound pressure levels have been measured in many sports halls. Most of these halls, for instance those made from stony materials, perform as predicted. However, sports halls constructed with profiled perforated steel roof panels have an unexpected

  16. A CFD Coupled Acoustics Approach for the Prediction of Coaxial Jet Noise

    Science.gov (United States)

    2003-02-01

    and Management of Gas Turbine Fleets for Extended Life and Reduced Costs [Les mecanismes vieillissants et le controle] [Symposium Partie A...a flow model for coaxial jets and extracting from these predictions the parameters required by the four source model (e.g. effective jet definition

  17. Development of nonlinear acoustic propagation analysis tool toward realization of loud noise environment prediction in aeronautics

    Energy Technology Data Exchange (ETDEWEB)

    Kanamori, Masashi, E-mail: kanamori.masashi@jaxa.jp; Takahashi, Takashi, E-mail: takahashi.takashi@jaxa.jp; Aoyama, Takashi, E-mail: aoyama.takashi@jaxa.jp [Japan Aerospace Exploration Agency, 7-44-1, Jindaijihigashi-machi, Chofu, Tokyo (Japan)

    2015-10-28

    Shown in this paper is an introduction of a prediction tool for the propagation of loud noise with the application to the aeronautics in mind. The tool, named SPnoise, is based on HOWARD approach, which can express almost exact multidimensionality of the diffraction effect at the cost of back scattering. This paper argues, in particular, the prediction of the effect of atmospheric turbulence on sonic boom as one of the important issues in aeronautics. Thanks to the simple and efficient modeling of the atmospheric turbulence, SPnoise successfully re-creates the feature of the effect, which often emerges in the region just behind the front and rear shock waves in the sonic boom signature.

  18. Data mining for rapid prediction of facility fit and debottlenecking of biomanufacturing facilities.

    Science.gov (United States)

    Yang, Yang; Farid, Suzanne S; Thornhill, Nina F

    2014-06-10

    Higher titre processes can pose facility fit challenges in legacy biopharmaceutical purification suites with capacities originally matched to lower titre processes. Bottlenecks caused by mismatches in equipment sizes, combined with process fluctuations upon scale-up, can result in discarding expensive product. This paper describes a data mining decisional tool for rapid prediction of facility fit issues and debottlenecking of biomanufacturing facilities exposed to batch-to-batch variability and higher titres. The predictive tool comprised advanced multivariate analysis techniques to interrogate Monte Carlo stochastic simulation datasets that mimicked batch fluctuations in cell culture titres, step yields and chromatography eluate volumes. A decision tree classification method, CART (classification and regression tree) was introduced to explore the impact of these process fluctuations on product mass loss and reveal the root causes of bottlenecks. The resulting pictorial decision tree determined a series of if-then rules for the critical combinations of factors that lead to different mass loss levels. Three different debottlenecking strategies were investigated involving changes to equipment sizes, using higher capacity chromatography resins and elution buffer optimisation. The analysis compared the impact of each strategy on mass output, direct cost of goods per gram and processing time, as well as consideration of extra capital investment and space requirements. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

  19. Development and validation of a combined phased acoustical radiosity and image source model for predicting sound fields in rooms

    DEFF Research Database (Denmark)

    Marbjerg, Gerd Høy; Brunskog, Jonas; Jeong, Cheol-Ho

    2015-01-01

    A model, combining acoustical radiosity and the image source method, including phase shifts on reflection, has been developed. The model is denoted Phased Acoustical Radiosity and Image Source Method (PARISM), and it has been developed in order to be able to model both specular and diffuse reflec...

  20. Analysis of predictive factors for rapid virologic response in treating patients with chronic hepatitis C

    Directory of Open Access Journals (Sweden)

    ZHANG Dandan

    2014-12-01

    Full Text Available ObjectiveTo analyze the predictive factors for rapid virologic response (RVR in patients with chronic hepatitis C (CHC who received combination therapy with pegylated interferon (PEG-IFN and ribavirin. MethodsA total of 127 CHC patients who were admitted to our department from 2010 to 2012 and received PEG-IFN combined with ribavirin were enrolled in this retrospective cohort study. The patients were divided into RVR group and non-RVR (NRVR group according to their virologic responses after 4 weeks of antiviral therapy. Demographic characteristics and the clinical features prior to treatment were compared between the two groups, and the potential factors that contributed to the acquisition of RVR were analyzed. Comparison of categorical data between groups was made by chi-square test, predictive factors were analyzed by nonparametric test for two independent samples (Mann-Whitney U test, independent predictive factors were tested by univariate and multivariate logistic regression analyses, and the continuous variables of predictive factors were analyzed using receiver operating characteristic curves. ResultsOf the 127 CHC patients, 86 were males and 41 females. There were 11 confirmed cases of liver cirrhosis. There were 100 patients (78.74% who achieved an RVR, and 27 (21.26% with NRVR. Nonparametric analysis showed that eight factors, which were age, time of infection, level of pre-treatment alanine aminotransferase, level of pre-treatment hyaluronic acid, development of hypertension, type of interferon, pathway of infection, and hepatitis C virus (HCV genotype, were significantly different between the RVR and NRVR groups (P<0.05. The logistic regression analysis identified the following factors as independent predictive factors for RVR: non-genotype 1 (OR: 0.203, 95%CI: 0.051-0.802, P<0.05, time of infection (OR: 0.925, 95%CI: 0.868-0.987, P<0.05, and absence of hypertension (OR: 0.129, 95%CI: 0.032-0.521, P<0.05. Conclusion

  1. Perceptual assimilation of French and German vowels by American English monolinguals: Acoustic similarity does not predict perceptual similarity

    Science.gov (United States)

    Strange, Winifred; Levy, Erika; Lehnholf, Robert

    2004-05-01

    Previous research in our laboratory has demonstrated that the perceived similarity of vowels across languages is not always predictable from the closeness of their target formant values in F1/F2/F3 space. In this study, perceptual similarity was established using a task in which 11 American English (AE) monolinguals were presented multiple tokens of 9 French vowels and 14 North German vowels (in separate blocks) produced in citation-form /hVb(a)/ (bi)syllables by native speakers. They selected 1 of 11 AE vowel responses to which each non-native vowel token was most similar, and rated its goodness on a 9-point Likert scale. Of special interest was the perceptual assimilation of front rounded French [y, oe] and German [y, Y, o/, oe] vowels. Acoustically, all six French and German vowels are more similar to front unrounded AE vowels. However, all six vowels were perceived to be more similar to back rounded AE vowels (range across vowels = 55% to 100%), although relatively poor exemplars. There were differences across languages in how the same vowel was assimilated (e.g., French /y/ assimilated to front AE vowels 13%, German /y/, 0% French [oe] 3%, German [oe] 45%). There were also large individual differences in listeners assimilation patterns. [Work supported by NIDCD.

  2. Predicting Where a Radiation Will Occur: Acoustic and Molecular Surveys Reveal Overlooked Diversity in Indian Ocean Island Crickets (Mogoplistinae: Ornebius.

    Directory of Open Access Journals (Sweden)

    Ben H Warren

    Full Text Available Recent theory suggests that the geographic location of island radiations (local accumulation of species diversity due to cladogenesis can be predicted based on island area and isolation. Crickets are a suitable group for testing these predictions, as they show both the ability to reach some of the most isolated islands in the world, and to speciate at small spatial scales. Despite substantial song variation between closely related species in many island cricket lineages worldwide, to date this characteristic has not received attention in the western Indian Ocean islands; existing species descriptions are based on morphology alone. Here we use a combination of acoustics and DNA sequencing to survey these islands for Ornebius crickets. We uncover a small but previously unknown radiation in the Mascarenes, constituting a three-fold increase in the Ornebius species diversity of this archipelago (from two to six species. A further new species is detected in the Comoros. Although double archipelago colonisation is the best explanation for species diversity in the Seychelles, in situ cladogenesis is the best explanation for the six species in the Mascarenes and two species of the Comoros. Whether the radiation of Mascarene Ornebius results from intra- or purely inter- island speciation cannot be determined on the basis of the phylogenetic data alone. However, the existence of genetic, song and ecological divergence at the intra-island scale is suggestive of an intra-island speciation scenario in which ecological and mating traits diverge hand-in-hand. Our results suggest that the geographic location of Ornebius radiations is partially but not fully explained by island area and isolation. A notable anomaly is Madagascar, where our surveys are consistent with existing accounts in finding no Ornebius species present. Possible explanations are discussed, invoking ecological differences between species and differences in environmental history between

  3. Rapid improvements in emotion regulation predict intensive treatment outcome for patients with bulimia nervosa and purging disorder.

    Science.gov (United States)

    MacDonald, Danielle E; Trottier, Kathryn; Olmsted, Marion P

    2017-10-01

    Rapid and substantial behavior change (RSBC) early in cognitive behavior therapy (CBT) for eating disorders is the strongest known predictor of treatment outcome. Rapid change in other clinically relevant variables may also be important. This study examined whether rapid change in emotion regulation predicted treatment outcomes, beyond the effects of RSBC. Participants were diagnosed with bulimia nervosa or purging disorder (N = 104) and completed ≥6 weeks of CBT-based intensive treatment. Hierarchical regression models were used to test whether rapid change in emotion regulation variables predicted posttreatment outcomes, defined in three ways: (a) binge/purge abstinence; (b) cognitive eating disorder psychopathology; and (c) depression symptoms. Baseline psychopathology and emotion regulation difficulties and RSBC were controlled for. After controlling for baseline variables and RSBC, rapid improvement in access to emotion regulation strategies made significant unique contributions to the prediction of posttreatment binge/purge abstinence, cognitive psychopathology of eating disorders, and depression symptoms. Individuals with eating disorders who rapidly improve their belief that they can effectively modulate negative emotions are more likely to achieve a variety of good treatment outcomes. This supports the formal inclusion of emotion regulation skills early in CBT, and encouraging patient beliefs that these strategies are helpful. © 2017 Wiley Periodicals, Inc.

  4. Using Bayesian Belief Network (BBN) modelling for rapid source term prediction. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Knochenhauer, M.; Swaling, V.H.; Dedda, F.D.; Hansson, F.; Sjoekvist, S.; Sunnegaerd, K. [Lloyd' s Register Consulting AB, Sundbyberg (Sweden)

    2013-10-15

    The project presented in this report deals with a number of complex issues related to the development of a tool for rapid source term prediction (RASTEP), based on a plant model represented as a Bayesian belief network (BBN) and a source term module which is used for assigning relevant source terms to BBN end states. Thus, RASTEP uses a BBN to model severe accident progression in a nuclear power plant in combination with pre-calculated source terms (i.e., amount, composition, timing, and release path of released radio-nuclides). The output is a set of possible source terms with associated probabilities. One major issue has been associated with the integration of probabilistic and deterministic analyses are addressed, dealing with the challenge of making the source term determination flexible enough to give reliable and valid output throughout the accident scenario. The potential for connecting RASTEP to a fast running source term prediction code has been explored, as well as alternative ways of improving the deterministic connections of the tool. As part of the investigation, a comparison of two deterministic severe accident analysis codes has been performed. A second important task has been to develop a general method where experts' beliefs can be included in a systematic way when defining the conditional probability tables (CPTs) in the BBN. The proposed method includes expert judgement in a systematic way when defining the CPTs of a BBN. Using this iterative method results in a reliable BBN even though expert judgements, with their associated uncertainties, have been used. It also simplifies verification and validation of the considerable amounts of quantitative data included in a BBN. (Author)

  5. Prediction of human iron bioavailability using rapid c-ELISAs for human plasma hepcidin.

    Science.gov (United States)

    Stoffel, Nicole U; Zeder, Christophe; Fort, Eloïse; Swinkels, Dorine W; Zimmermann, Michael B; Moretti, Diego

    2017-07-26

    Hepcidin is the central systemic regulator of iron metabolism, but its quantification in biological fluids is challenging. Rapid, accurate and user-friendly methods are needed. Our aim was to assess the ability of hepcidin as measured by three different c-ELISA assays to predict iron bioavailability in humans. The three assays used were commercially available DRG and Peninsula assays and the c-ELISA method performed at Radboud University Medical Centre, Nijmegen, The Netherlands (Hepcidinanalysis.com), validated by comparative measurements with time-of-flight mass spectrometry. We analyzed plasma samples (n=37) selected to represent a broad range of hepcidin concentrations from a subgroup of healthy, iron-depleted women in a study assessing fractional absorption from iron supplements. In single regressions, all three c-ELISA assays were predictors of fractional iron absorption: R2=0.363 (DRG), R2=0.281 (Peninsula) and R2=0.327 (Hepcidinanalysis.com). In multiple regressions, models including hepcidin measured with either DRG-, Peninsula or Hepcidinanalysis.com explained 55.7%, 44.5% and 52.5% of variance in fractional absorption, and hepcidin was a strong predictor of fractional absorption irrespective of the hepcidin assays used. However, we found significant differences in absolute values for hepcidin between different methods. Both the DRG assay's (y=0.61x+0.87; R2=0.873) and the Peninsula assay's measurements (y=1.88x+0.62; R2=0.770) were correlated with Hepcidinanalysis.com. The biological variability in plasma hepcidin, (inter-sample CV) was 5-10-fold higher for both the Peninsula and DRG assay than the analytical variably (inter-run within-sample CV) suggesting substantial discriminatory power to distinguish biological hepcidin variation. Between methods, prediction of iron bioavailability in generally healthy iron depleted subjects appears comparable.

  6. Rapid response predicts 12-month post-treatment outcomes in binge-eating disorder: theoretical and clinical implications

    Science.gov (United States)

    Grilo, C. M.; White, M. A.; Wilson, G. T.; Gueorguieva, R.; Masheb, R. M.

    2011-01-01

    Background We examined rapid response in obese patients with binge-eating disorder (BED) in a clinical trial testing cognitive behavioral therapy (CBT) and behavioral weight loss (BWL). Method Altogether, 90 participants were randomly assigned to CBT or BWL. Assessments were performed at baseline, throughout and post-treatment and at 6- and 12-month follow-ups. Rapid response, defined as ≥70% reduction in binge eating by week four, was determined by receiver operating characteristic curves and used to predict outcomes. Results Rapid response characterized 57% of participants (67% of CBT, 47% of BWL) and was unrelated to most baseline variables. Rapid response predicted greater improvements across outcomes but had different prognostic significance and distinct time courses for CBT versus BWL. Patients receiving CBT did comparably well regardless of rapid response in terms of reduced binge eating and eating disorder psychopathology but did not achieve weight loss. Among patients receiving BWL, those without rapid response failed to improve further. However, those with rapid response were significantly more likely to achieve binge-eating remission (62% v. 13%) and greater reductions in binge-eating frequency, eating disorder psychopathology and weight loss. Conclusions Rapid response to treatment in BED has prognostic significance through 12-month follow-up, provides evidence for treatment specificity and has clinical implications for stepped-care treatment models for BED. Rapid responders who receive BWL benefit in terms of both binge eating and short-term weight loss. Collectively, these findings suggest that BWL might be a candidate for initial intervention in stepped-care models with an evaluation of progress after 1 month to identify non-rapid responders who could be advised to consider a switch to a specialized treatment. PMID:21923964

  7. Hippocampal size predicts rapid learning of a cognitive map in humans.

    Science.gov (United States)

    Schinazi, Victor R; Nardi, Daniele; Newcombe, Nora S; Shipley, Thomas F; Epstein, Russell A

    2013-06-01

    The idea that humans use flexible map-like representations of their environment to guide spatial navigation has a long and controversial history. One reason for this enduring controversy might be that individuals vary considerably in their ability to form and utilize cognitive maps. Here we investigate the behavioral and neuroanatomical signatures of these individual differences. Participants learned an unfamiliar campus environment over a period of three weeks. In their first visit, they learned the position of different buildings along two routes in separate areas of the campus. During the following weeks, they learned these routes for a second and third time, along with two paths that connected both areas of the campus. Behavioral assessments after each learning session indicated that subjects formed a coherent representation of the spatial structure of the entire campus after learning a single connecting path. Volumetric analyses of structural MRI data and voxel-based morphometry (VBM) indicated that the size of the right posterior hippocampus predicted the ability to use this spatial knowledge to make inferences about the relative positions of different buildings on the campus. An inverse relationship between gray matter volume and performance was observed in the caudate. These results suggest that (i) humans can rapidly acquire cognitive maps of large-scale environments and (ii) individual differences in hippocampal anatomy may provide the neuroanatomical substrate for individual differences in the ability to learn and flexibly use these cognitive maps. © 2013 Wiley Periodicals, Inc. Copyright © 2013 Wiley Periodicals, Inc.

  8. Predictive Factors of Rapid Cognitive Decline in Patients with Alzheimer Disease

    Directory of Open Access Journals (Sweden)

    Coralie Barbe

    2016-12-01

    Full Text Available Aim: To determine predictive factors associated with rapid cognitive decline (RCD in elderly patients suffering from Alzheimer disease (AD. Methods: Patients suffering from mild to moderate AD were included. RCD was defined as the loss of at least 3 points on the Mini-Mental State Examination (MMSE over 12 months. Factors associated with RCD were identified by logistic regression. Results: Among 123 patients included, 61 were followed up until 12 months. RCD occurred in 46% of patients (n = 28. Polymedication (p < 0.0001, the fact that the caregiver was the child or spouse of the patient (p < 0.0001 and autonomy for washing (p < 0.0001 were protective factors against RCD, while the presence of caregiver burden (p < 0.0001 was shown to be a risk factor for RCD. Conclusion: Early detection of the RCD risk in AD patients could make it possible to anticipate the patient’s medical needs and adjust the care plan for caregiver burden.

  9. Rapid antibiotic-resistance predictions from genome sequence data for Staphylococcus aureus and Mycobacterium tuberculosis

    Science.gov (United States)

    Bradley, Phelim; Gordon, N. Claire; Walker, Timothy M.; Dunn, Laura; Heys, Simon; Huang, Bill; Earle, Sarah; Pankhurst, Louise J.; Anson, Luke; de Cesare, Mariateresa; Piazza, Paolo; Votintseva, Antonina A.; Golubchik, Tanya; Wilson, Daniel J.; Wyllie, David H.; Diel, Roland; Niemann, Stefan; Feuerriegel, Silke; Kohl, Thomas A.; Ismail, Nazir; Omar, Shaheed V.; Smith, E. Grace; Buck, David; McVean, Gil; Walker, A. Sarah; Peto, Tim E. A.; Crook, Derrick W.; Iqbal, Zamin

    2015-01-01

    The rise of antibiotic-resistant bacteria has led to an urgent need for rapid detection of drug resistance in clinical samples, and improvements in global surveillance. Here we show how de Bruijn graph representation of bacterial diversity can be used to identify species and resistance profiles of clinical isolates. We implement this method for Staphylococcus aureus and Mycobacterium tuberculosis in a software package (‘Mykrobe predictor') that takes raw sequence data as input, and generates a clinician-friendly report within 3 minutes on a laptop. For S. aureus, the error rates of our method are comparable to gold-standard phenotypic methods, with sensitivity/specificity of 99.1%/99.6% across 12 antibiotics (using an independent validation set, n=470). For M. tuberculosis, our method predicts resistance with sensitivity/specificity of 82.6%/98.5% (independent validation set, n=1,609); sensitivity is lower here, probably because of limited understanding of the underlying genetic mechanisms. We give evidence that minor alleles improve detection of extremely drug-resistant strains, and demonstrate feasibility of the use of emerging single-molecule nanopore sequencing techniques for these purposes. PMID:26686880

  10. On the possibility and predictability of rapid Arctic winter sea-ice loss

    Science.gov (United States)

    Bathiany, Sebastian; Notz, Dirk; Mauritsen, Thorsten; Raedel, Gaby; Brovkin, Victor; van der Bolt, Bregje; Scheffer, Marten; van Nes, Egbert; Williamson, Mark; Lenton, Tim

    2016-04-01

    We examine the transition from a seasonally ice-covered Arctic to an Arctic Ocean that is sea-ice free all year round under increasing atmospheric CO2 levels. Using two column models and nine Earth System Models, we investigate how rapid such Arctic winter sea-ice loss can be, and whether an abrupt ice loss can be predicted from observed trends in variance or autocorrelation. Such statistical indicators have been proposed as early warning signals of abrupt shifts that are caused by positive feedbacks. We show that in comprehensive climate models, the loss of winter sea-ice area is faster than the preceding loss of summer sea-ice area for the same rate of warming. In two of the models, several million km2 of winter sea ice are lost within only one decade. Their behaviour resembles the catastrophic winter ice loss in a column model where the stable ice-covered state suddenly disappears at a bifurcation point, implying an irreversible and abrupt shift to the ice-free solution. However, we argue that winter sea-ice loss in comprehensive models is reversible and not associated with the existence of multiple steady states. The large sensitivity of winter sea-ice area in complex models is caused by the asymmetry between melting and freezing: An ice-free summer requires the complete melt of even the thickest sea ice, which is why the perennial ice coverage decreases only gradually as more and more of the thinner ice melts away. In winter, however, sea-ice areal coverage remains high as long as sea ice still forms, and then drops to zero wherever the ocean warms sufficiently to no longer form ice during winter. As this mechanism occurs in every model we analyse and is independent of any specific parameterisation, it is likely to be relevant in the real world. We also find that expected trends in variance and autocorrelation of sea-ice area and thickness are not specific to the existence or the mechanism of abrupt ice loss. For example, natural fluctuations of ice volume

  11. Frequency effects on the scale and behavior of acoustic streaming.

    Science.gov (United States)

    Dentry, Michael B; Yeo, Leslie Y; Friend, James R

    2014-01-01

    Acoustic streaming underpins an exciting range of fluid manipulation phenomena of rapidly growing significance in microfluidics, where the streaming often assumes the form of a steady, laminar jet emanating from the device surface, driven by the attenuation of acoustic energy within the beam of sound propagating through the liquid. The frequencies used to drive such phenomena are often chosen ad hoc to accommodate fabrication and material issues. In this work, we seek a better understanding of the effects of sound frequency and power on acoustic streaming. We present and, using surface acoustic waves, experimentally verify a laminar jet model that is based on the turbulent jet model of Lighthill, which is appropriate for acoustic streaming seen at micro- to nanoscales, between 20 and 936 MHz and over a broad range of input power. Our model eliminates the critically problematic acoustic source singularity present in Lighthill's model, replacing it with a finite emission area and enabling determination of the streaming velocity close to the source. At high acoustic power P (and hence high jet Reynolds numbers ReJ associated with fast streaming), the laminar jet model predicts a one-half power dependence (U∼P1/2∼ ReJ) similar to the turbulent jet model. However, the laminar model may also be applied to jets produced at low powers-and hence low jet Reynolds numbers ReJ-where a linear relationship between the beam power and streaming velocity exists: U∼P∼ReJ2. The ability of the laminar jet model to predict the acoustic streaming behavior across a broad range of frequencies and power provides a useful tool in the analysis of microfluidics devices, explaining peculiar observations made by several researchers in the literature. In particular, by elucidating the effects of frequency on the scale of acoustically driven flows, we show that the choice of frequency is a vitally important consideration in the design of small-scale devices employing acoustic streaming

  12. Predicting Bird and Bat Fatality Risk at Wind Farms and Proposed Wind Farm Sites Using Acoustic-Ultrasonic Recorders

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This project has three objectives: (1) evaluate the ability of dual acoustic-ultrasonic recorders to capture nocturnal calls of birds and bats at wind power sites;...

  13. Architectural acoustics

    National Research Council Canada - National Science Library

    Long, Marshall

    2014-01-01

    .... Beginning with a brief history, it reviews the fundamentals of acoustics, human perception and reaction to sound, acoustic noise measurements, noise metrics, and environmental noise characterization...

  14. On acoustic emission for damage detection and failure prediction in fiber reinforced polymer rods using pattern recognition analysis

    Science.gov (United States)

    Shateri, Mohammadhadi; Ghaib, Maha; Svecova, Dagmar; Thomson, Douglas

    2017-06-01

    Fiber reinforced polymer (FRP) rods are used for pre-stressing and reinforcing in civil engineering applications. Damage in FRP rods can lead to sudden brittle failure, therefore, a reliable method that provides indicators of damage progression and potential failure in FRP rods is highly desirable. Acoustic emission (AE) signal analysis has been used for damage detection and monitoring of FRP materials. In this study, a new AE event detection algorithm, utilizing the root mean square envelope of AE signal, is applied to AE data to isolate each AE event separately, even when AE events are nearly coincident. A fuzzy c-means (FCM) clustering algorithm is used to classify these isolated AE events into 3 clusters. Scanning electron microscopy images of FRP rod cross-sections also show 3 types of damage. The hypothesis in this study is that each cluster represents a damage mechanism. The number of events in each cluster is monitored versus the percent of the ultimate load. The ratio of the number of AE events in one of the FCM clusters to the number of AE events in another FCM cluster was useful for providing an indication of when the stress levels have reached the point where the loads may cause the FRP rod to fail. The results of applying this parameter to four FRP rods show a significant slope change (factor of 10) in this ratio at around 40% and 60% of the ultimate load for glass FRP rods and carbon FRP rods, respectively. This method may prove useful in damage progression and failure prediction of the FRP rods in prefabricated structures where pre-stressed FRP is used and in field monitoring of FRP materials.

  15. Comparison of Acoustic Energy Meter (AEM) and Schmidt hammer 'R' for rapid assessment of rock surface hardness: a preliminary assessment from southeast Queensland, Australia

    Science.gov (United States)

    Brook, Martin; Winkler, Stefan

    2015-04-01

    This research focuses on one of the key challenges in geomorphology - quantifying rock surface hardness via in situ measurements, to provide information on rock physical properties. This has been a focus in recent years with the rapid emergence of studies that center on surface and near surface weathering impacts, and rates of material loss. Indeed, a key element to understanding how weathering and erosion processes combine to influence rock surface (and landscape) evolution is the measurement and monitoring of rock surface hardness. We provide results from a preliminary assessment of the applicability of the Acoustic Energy Meter (AEM) to subaerial rock surface hardness, in comparison with an N-Type Schmidt hammer. The AEM apparatus consists of a geophone which is in contact with the rock surface and some electronics. The AEM is held normal to the surface to be tested and the surface is struck with a small hammer (typically 0.75 kg), with the AEM quantifying the decay time of seismically-induced oscillations within the top c. 1-2 m of the rock mass. Previous work using an AEM has focused on measuring roof stability and delamination in South African underground coal, gold and platinum mines, where long AEM reverberation times correlated well with weak rock mass and dense microfracturing. However, the technique has rarely been applied to the assessment of rock surfaces in a subaerial setting. We applied the technique to a range of lithologies at five sites in southeast Queensland in the Brisbane area, each an exposure of phyllite, granite, mudstone, argillite or volcanic tuff. The aims were: (1) quantifying the response of different rock masses to the AEM technique; and (2) assessing the applicability of the AEM as a rapid in situ measure of rock hardness by comparing results with Schmidt hammer 'R' values from the same exposures. Results showed that the AEM is useful in discriminating rock hardness across rocks with different lithological properties. Second, an

  16. Towards the prediction of cohesive sediments dynamics: developing acoustic and optical measurements via in situ particle visualization.

    Science.gov (United States)

    Schindler, Rob; Bass, Sarah; Manning, Andrew

    2010-05-01

    Cohesive particles in marine and costal waters remain a significant challenge to sediment transport predictions. Given the relevance to water quality, pollution, benthic ecology and coastal engineering our ability to develop process-response models of cohesive sediments is poor. Suspended cohesive particles rarely exist in their primary state but form flocs which are aggregated, heterogeneous assemblages of mineral grains, biogenic debris, bacteria and organic material. Floc formation is thus a function of numerous variables whose inter-related processes are yet to be fully elucidated. This complexity is exacerbated by a lack of suitable data, notably in characterizing floc populations. A floc may constitute over 1 million individual particles and size can range over 4 orders of magnitude within one population. The effective densities are also highly variable, and the settling velocity can therefore span several orders of magnitude (Fennessey et al., 1994; Gibbs, 1985). The challenge is to develop data acquisition techniques that will allow accurate quantification of floc characteristics for the determination of SPM concentration and settling velocities for mass settling flux calculations. Particle size ranges and concentrations are not adequately measurable by physical sampling which break up fragile flocs. Remote methods offer the potential to greatly enhance our understanding of floc particle dynamics. However, the responses of light and sound to floc particles remain uncertain. Differences in derived mass concentrations of flocculated and non-cohesive suspensions occur because OBS measures projected area concentration not mass concentration. Laser interferometry (e.g. LISST) is only applicable in relatively low concentrations, can disturb fragile flocs and requires a smooth size distribution and near-spherical particles (e.g. Wren et al., 2000). Acoustic backscatter methods are limited by a lack of data from floc-dominated environments which has restricted the

  17. [Prediction of the side-cut product yield of atmospheric/vacuum distillation unit by NIR crude oil rapid assay].

    Science.gov (United States)

    Wang, Yan-Bin; Hu, Yu-Zhong; Li, Wen-Le; Zhang, Wei-Song; Zhou, Feng; Luo, Zhi

    2014-10-01

    In the present paper, based on the fast evaluation technique of near infrared, a method to predict the yield of atmos- pheric and vacuum line was developed, combined with H/CAMS software. Firstly, the near-infrared (NIR) spectroscopy method for rapidly determining the true boiling point of crude oil was developed. With commercially available crude oil spectroscopy da- tabase and experiments test from Guangxi Petrochemical Company, calibration model was established and a topological method was used as the calibration. The model can be employed to predict the true boiling point of crude oil. Secondly, the true boiling point based on NIR rapid assay was converted to the side-cut product yield of atmospheric/vacuum distillation unit by H/CAMS software. The predicted yield and the actual yield of distillation product for naphtha, diesel, wax and residual oil were compared in a 7-month period. The result showed that the NIR rapid crude assay can predict the side-cut product yield accurately. The near infrared analytic method for predicting yield has the advantages of fast analysis, reliable results, and being easy to online operate, and it can provide elementary data for refinery planning optimization and crude oil blending.

  18. Usefulness of a rapid faecal calprotectin test to predict relapse in Crohn's disease patients on maintenance treatment with adalimumab.

    Science.gov (United States)

    Ferreiro-Iglesias, Rocio; Barreiro-de Acosta, Manuel; Lorenzo-Gonzalez, Aurelio; Dominguez-Muñoz, Juan Enrique

    2016-01-01

    Predicting relapse in Crohn's disease (CD) patients by measuring non-invasive biomarkers could allow for early changes of treatment. Data are scarce regarding the utility of monitoring calprotectin to predict relapse. The aim of the study was to evaluate the predictive value of a rapid test of faecal calprotectin (FC) to predict for flares in CD patients on maintenance treatment with adalimumab (ADA). A prospective, observational cohort study was designed. Inclusion criteria were CD patients in clinical remission on a standard dose of ADA therapy. Fresh FC was measured using a rapid test. Thirty patients were included (median age 38 years, 56.7% female). After the 4 months follow-up, 70.0% patients remained in clinical remission and 30.0% had a relapse. FC concentration at inclusion was significantly higher in those patients who relapsed during the follow-up (625 μg/g) compared to those who stayed in remission (45 μg/g). The optimal cut-off for FC to predict relapse was 204 μg/g. The area under the receiver-operating characteristic curve was 0.968. Sensitivity, specificity, positive, and negative predictive value of FC to predict relapse were 100%, 85.7%, 74.1%, and 100%, respectively. In CD patients on ADA maintenance therapy, FC levels measured with a rapid test allow relapse over the following months to be predicted with high accuracy. Low FC levels exclude relapse within at least 4 months after testing, whereas high levels are associated with relapse in three out of every four patients.

  19. Virtual Acoustics

    Science.gov (United States)

    Lokki, Tapio; Savioja, Lauri

    The term virtual acoustics is often applied when sound signal is processed to contain features of a simulated acoustical space and sound is spatially reproduced either with binaural or with multichannel techniques. Therefore, virtual acoustics consists of spatial sound reproduction and room acoustics modeling.

  20. Rapid Response Predicts Treatment Outcomes in Binge Eating Disorder: Implications for Stepped Care

    Science.gov (United States)

    Masheb, Robin M.; Grilo, Carlos M.

    2007-01-01

    The authors examined rapid response in 75 overweight patients with binge eating disorder (BED) who participated in a randomized clinical trial of guided self-help treatments (cognitive-behavioral therapy [CBTgsh] and behavioral weight loss [BWLgsh]). Rapid response, defined as a 65% or greater reduction in binge eating by the 4th treatment week,…

  1. U-rans model for the prediction of the acoustic sound power generated in a whistling corrugated pipe

    NARCIS (Netherlands)

    Golliard, J.; González Díez, N.; Belfroid, S.P.C.; Nakiboǧlu, G.; Hirschberg, A.

    2013-01-01

    Corrugated pipes, as used in flexible risers for gas production or in domestic appliances, can whistle when a flow is imposed through the pipe. Nakiboglu et al [1, 2] have developed a method to compute the acoustic source term for axi-symmetric cavities. The method is based on the resolution of

  2. 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 chapt......: acoustics, cognitive science, speech science, and communication technology.......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...

  3. 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....

  4. Communication Acoustics

    DEFF Research Database (Denmark)

    Blauert, Jens

    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......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......: acoustics, cognitive science, speech science, and communication technology....

  5. 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......: acoustics, cognitive science, speech science, and communication technology....... 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...

  6. Comparison of streamflow prediction skills from NOAH-MP/RAPID, VIC/RAPID and SWAT toward an ensemble flood forecasting framework over large scales

    Science.gov (United States)

    Rajib, M. A.; Tavakoly, A. A.; Du, L.; Merwade, V.; Lin, P.

    2015-12-01

    Considering the differences in how individual models represent physical processes for runoff generation and streamflow routing, use of ensemble output is desirable in an operational streamflow estimation and flood forecasting framework. To enable the use of ensemble streamflow, comparison of multiple hydrologic models at finer spatial resolution over a large domain is yet to be explored. The objective of this work is to compare streamflow prediction skills from three different land surface/hydrologic modeling frameworks: NOAH-MP/RAPID, VIC/RAPID and SWAT, over the Ohio River Basin with a drainage area of 491,000 km2. For a uniform comparison, all the three modeling frameworks share the same setup with common weather inputs, spatial resolution, and gauge stations being employed in the calibration procedure. The runoff output from NOAH-MP and VIC land surface models is routed through a vector-based river routing model named RAPID, that is set up on the high resolution NHDPlus reaches and catchments. SWAT model is used with its default tightly coupled surface-subsurface hydrology and channel routing components to obtain streamflow for each NHDPlus reach. Model simulations are performed in two modes, including: (i) hindcasting/calibration mode in which the models are calibrated against USGS daily streamflow observations at multiple locations, and (ii) validation mode in which the calibrated models are executed at 3-hourly time interval for historical flood events. In order to have a relative assessment on the model-specific nature of biases during storm events as well as dry periods, time-series of surface runoff and baseflow components at the specific USGS gauging locations are extracted from corresponding observed/simulated streamflow data using a recursive digital filter. The multi-model comparison presented here provides insights toward future model improvements and also serves as the first step in implementing an operational ensemble flood forecasting framework

  7. Rapid biochemical methane potential prediction of urban organic waste with near-infrared reflectance spectroscopy

    DEFF Research Database (Denmark)

    Fitamo, Temesgen Mathewos; Triolo, Jin Mi; Boldrin, Alessio

    2017-01-01

    . The aim of the present study is to develop a fast and reliable model based on near-infrared reflectance spectroscopy (NIRS) for the BMP prediction of urban organic waste (UOW). The model comprised 87 UOW samples. Additionally, 88 plant biomass samples were included, to develop a combined model predicting...

  8. Rapid Responsiveness to Practice Predicts Longer-Term Retention of Upper Extremity Motor Skill in Non-Demented Older Adults.

    Science.gov (United States)

    Schaefer, Sydney Y; Duff, Kevin

    2015-01-01

    Skill acquisition is a form of motor learning that may provide key insights into the aging brain. Although previous work suggests that older adults learn novel motor tasks slower and to a lesser extent than younger adults, we have recently demonstrated no significant effect of chronological age on the rates and amounts of skill acquisition, nor on its long-term retention, in adults over the age of 65. To better understand predictors of skill acquisition in non-demented older adults, we now explore the relationship between early improvements in motor performance due to practice (i.e., rapid responsiveness) and longer-term retention of an upper extremity motor skill, and whether the extent of rapid responsiveness was associated with global cognitive status. Results showed significant improvements in motor performance within the first five (of 150) trials, and that this "rapid responsiveness" was predictive of skill retention 1 month later. Notably, the extent of rapid responsiveness was not dependent on global cognitive status, as measured by the Montreal Cognitive Assessment (MoCA). Thus, rapid responsiveness appears to be an important variable in longer-term neurorehabilitative efforts with older adults, regardless of their cognitive status.

  9. 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 ...

  10. Monitoring microstructural evolution of alloy 617 with non-linear acoustics for remaining useful life prediction; multiaxial creep-fatigue and creep-ratcheting

    Energy Technology Data Exchange (ETDEWEB)

    Lissenden, Cliff [Pennsylvania State Univ., State College, PA (United States); Hassan, Tasnin [North Carolina State Univ., Raleigh, NC (United States); Rangari, Vijaya [Tuskegee Univ., Tuskegee, AL (United States)

    2014-10-30

    application of the harmonic generation method to tubular mechanical test specimens and pipes for nondestructive evaluation. Tubular specimens and pipes act as waveguides, thus we applied the acoustic harmonic generation method to guided waves in both plates and shells. Magnetostrictive transducers were used to generate and receive guided wave modes in the shell sample and the received signals were processed to show the sensitivity of higher harmonic generation to microstructure evolution. Modeling was initiated to correlate higher harmonic generation with the microstructure that will lead to development of a life prediction model that is informed by the nonlinear acoustics measurements.

  11. Rapid yet accurate first principle based predictions of alkali halide crystal phases using alchemical perturbation

    CERN Document Server

    Solovyeva, Alisa

    2016-01-01

    We assess the predictive power of alchemical perturbations for estimating fundamental properties in ionic crystals. Using density functional theory we have calculated formation energies, lattice constants, and bulk moduli for all sixteen iso-valence-electronic combinations of pure pristine alkali halides involving elements $A \\in \\{$Na, K, Rb, Cs$\\}$ and $X \\in \\{$F, Cl, Br, I$\\}$. For rock salt, zincblende and cesium chloride symmetry, alchemical Hellmann-Feynman derivatives, evaluated along lattice scans of sixteen reference crystals, have been obtained for all respective 16$\\times$15 combinations of reference and predicted target crystals. Mean absolute errors (MAE) are on par with density functional theory level of accuracy for energies and bulk modulus. Predicted lattice constants are less accurate. NaCl is the best reference salt for alchemical estimates of relative energies (MAE $<$ 40 meV/atom) while alkali fluorides are the worst. By contrast, lattice constants are predicted best using NaF as a re...

  12. RADIATION ACOUSTICS

    OpenAIRE

    Lyamshev, L.

    1990-01-01

    Radiation acoustics is a new branch of acoustics. Its' fundamentals are lying in the research of acoustical effects due to the interaction of a radiation with matter. The sound excitation in liquids and solids by modulated or pulsed particle beams (electron, proton, ion beams, γ-radiation and single high-energy elementary particles) and some practical applications are discussed.

  13. Negative Affect-Associated USV Acoustic Characteristics Predict Future Excessive Alcohol Drinking and Alcohol Avoidance in Male P and NP Rats.

    Science.gov (United States)

    Reno, James M; Thakore, Neha; Cormack, Lawrence K; Schallert, Timothy; Bell, Richard L; Maddox, W Todd; Duvauchelle, Christine L

    2017-04-01

    Negative emotional status and adverse emotional events increase vulnerability to alcohol abuse. Ultrasonic vocalizations (USVs) emitted by rats are a well-established model of emotional status that can reflect positive or negative affective responses in real time. Most USV studies assess counts, yet each USV is a multidimensional data point characterized by several acoustic characteristics that may provide insight into the neurocircuitry underlying emotional response. USVs emitted from selectively bred alcohol-naïve and alcohol-experienced alcohol-preferring and nonpreferring rats (P and NP rats) were recorded during 4-hour sessions on alternating days over 4 weeks. Linear mixed modeling (LMM) and linear discriminant analysis (LDA) were applied to USV acoustic characteristics (e.g., frequency, duration, power, and bandwidth) of negative affect (22 to 28 kilohertz [kHz])- and positive (50 to 55 kHz) affect-related USVs. Hundred percent separation between alcohol-naïve P and NP rats was achieved through a linear combination (produced by LDA) of USV acoustic characteristics of 22- to 28-kHz USVs, whereas poor separation (36.5%) was observed for 50- to 55-kHz USVs. 22- to 28-kHz LDA separation was high (87%) between alcohol-experienced P and NP rats, but was poor for 50- to 55-kHz USVs (57.3%). USV mean frequency and duration were the highest weighted characteristics in both the naïve and experienced 22- to 28-kHz LDA representations suggesting that alcohol experience does not alter the representations. LMM analyses of 22- to 28-kHz USV acoustic characteristics matched the LDA results. Poor LDA separation was observed between alcohol-naïve and alcohol-experienced P rats for both 22- to 28-kHz and 50- to 55-kHz USVs. Advanced statistical analysis of negative affect-associated USV data predicts future behaviors of excessive alcohol drinking and alcohol avoidance in selectively bred rats. USV characteristics across rat lines reveal affect-related motivation to

  14. Rapid and accurate prediction and scoring of water molecules in protein binding sites.

    Directory of Open Access Journals (Sweden)

    Gregory A Ross

    Full Text Available Water plays a critical role in ligand-protein interactions. However, it is still challenging to predict accurately not only where water molecules prefer to bind, but also which of those water molecules might be displaceable. The latter is often seen as a route to optimizing affinity of potential drug candidates. Using a protocol we call WaterDock, we show that the freely available AutoDock Vina tool can be used to predict accurately the binding sites of water molecules. WaterDock was validated using data from X-ray crystallography, neutron diffraction and molecular dynamics simulations and correctly predicted 97% of the water molecules in the test set. In addition, we combined data-mining, heuristic and machine learning techniques to develop probabilistic water molecule classifiers. When applied to WaterDock predictions in the Astex Diverse Set of protein ligand complexes, we could identify whether a water molecule was conserved or displaced to an accuracy of 75%. A second model predicted whether water molecules were displaced by polar groups or by non-polar groups to an accuracy of 80%. These results should prove useful for anyone wishing to undertake rational design of new compounds where the displacement of water molecules is being considered as a route to improved affinity.

  15. Rapid in vitro test to predict ocular tissue permeability based on biopartitioning micellar chromatography.

    Science.gov (United States)

    Martín-Biosca, Y; Molero-Monfort, M; Sagrado, S; Villanueva-Camañas, R M; Medina-Hernández, M J

    2003-10-01

    The drug permeability prediction across the ocular tissues is important in the development of new drugs and drug delivery strategies. Physicochemical characteristics of drugs, mainly acid-base character, hydrophobicity and the molecular size determine both their transport across the eye tissue barriers and their retention in biopartitioning micellar chromatography (BMC). An in vitro model able to describe and predict the whole cornea drug permeability is proposed. The model uses the retention of drugs in BMC and molecular weight (MW) as predictive variables. The relationships between drug retention data in BMC and their bibliographic permeability values in stroma, epithelium-plus-stroma and endothelium-plus-stroma are also studied. The results show that BMC can be a useful tool to select drug candidates according to their whole cornea permeability at the early stage of the drug discovery process.

  16. Tool And Algorithms for Rapid Source Term Prediction (RASTEP) Based on Bayesian Belief Networks

    OpenAIRE

    Agrawal, Prerna

    2015-01-01

    In case of an accident in a nuclear power plant (NPP), the fast and cor-rect identification of the NPP state that would give a prediction of a possible radioactive release presents a major challenge to both nuclear power plants and regulators. Such prediction is important so that correct and timely decisions and measures are taken to mitigate accident consequences, such as evacuation of people from areas around the power plant. Recent research work [2][3] proposes analyzing the NPP using the ...

  17. Rapid decision tool to predict earthquake destruction in Sumatra by using first motion study

    Science.gov (United States)

    Bhakta, Shardul Sanjay

    The main idea of this project is to build an interactive and smart Geographic Information system tool which can help predict intensity of real time earthquakes in Sumatra Island of Indonesia. The tool has an underlying intelligence to predict the intensity of an earthquake depending on analysis of similar earthquakes in the past in that specific region. Whenever an earthquake takes place in Sumatra, a First Motion Study is conducted; this decides its type, depth, latitude and longitude. When the user inputs this information into the input string, the tool will try to find similar earthquakes with a similar First Motion Survey and depth. It will do a survey of similar earthquakes and predict if this real time earthquake can be disastrous or not. This tool has been developed in JAVA. I have used MOJO (Map Objects JAVA Objects) to show map of Indonesia and earthquake locations in the form of points. ESRI has created MOJO which is a set of JAVA API's. The Indonesia map, earthquake location points and its co-relation was all designed using MOJO. MOJO is a powerful tool which made it easy to design the tool. This tool is easy to use and the user has to input only a few parameters for the end result. I hope this tool justifies its use in prediction of earthquakes and help save lives in Sumatra.

  18. OrthoReD: a rapid and accurate orthology prediction tool with low computational requirement.

    Science.gov (United States)

    Battenberg, Kai; Lee, Ernest K; Chiu, Joanna C; Berry, Alison M; Potter, Daniel

    2017-06-21

    Identifying orthologous genes is an initial step required for phylogenetics, and it is also a common strategy employed in functional genetics to find candidates for functionally equivalent genes across multiple species. At the same time, in silico orthology prediction tools often require large computational resources only available on computing clusters. Here we present OrthoReD, an open-source orthology prediction tool with accuracy comparable to published tools that requires only a desktop computer. The low computational resource requirement of OrthoReD is achieved by repeating orthology searches on one gene of interest at a time, thereby generating a reduced dataset to limit the scope of orthology search for each gene of interest. The output of OrthoReD was highly similar to the outputs of two other published orthology prediction tools, OrthologID and/or OrthoDB, for the three dataset tested, which represented three phyla with different ranges of species diversity and different number of genomes included. Median CPU time for ortholog prediction per gene by OrthoReD executed on a desktop computer was <15 min even for the largest dataset tested, which included all coding sequences of 100 bacterial species. With high-throughput sequencing, unprecedented numbers of genes from non-model organisms are available with increasing need for clear information about their orthologies and/or functional equivalents in model organisms. OrthoReD is not only fast and accurate as an orthology prediction tool, but also gives researchers flexibility in the number of genes analyzed at a time, without requiring a high-performance computing cluster.

  19. Use of basic biological information for rapid prediction of the response of species to habitat loss.

    Science.gov (United States)

    Hockey, Philip A R; Curtis, Odette E

    2009-02-01

    Much research has focused on identifying traits that can act as useful indicators of how habitat loss affects the extinction risk of species, and the results are mixed. We developed 2 simple, rapid-assessment models of the susceptibility of species to habitat loss. We based both on an index of range size, but one also incorporated an index of body mass and the other an index combining habitat and dietary specialization. We applied the models to samples of birds (Accipitridae and Bucerotidae) and to the lemurs of Madagascar and compared the models' classifications of risk with the IUCN's global threat status of each species. The model derived from ecological attributes was much more robust than the one derived from body mass. Ecological attributes identified threatened birds and lemurs with an average of 80% accuracy and endangered and critically endangered species with 100% accuracy and identified some species not currently listed as threatened that almost certainly warrant conservation consideration. Appropriate analysis of even fairly crude biological information can help raise early-warning flags to the relative susceptibilities of species to habitat loss and thus provide a useful and rapid technique for highlighting potential species-level conservation issues. Advantages of this approach to classifying risk include flexibility in the specialization parameters used as well as its applicability at a range of spatial scales.

  20. Ares I Scale Model Acoustic Test Lift-Off Acoustics

    Science.gov (United States)

    Counter, Douglas D.; Houston, Janie D.

    2011-01-01

    The lift-off acoustic (LOA) environment is an important design factor for any launch vehicle. For the Ares I vehicle, the LOA environments were derived by scaling flight data from other launch vehicles. The Ares I LOA predicted environments are compared to the Ares I Scale Model Acoustic Test (ASMAT) preliminary results.

  1. Rapid prediction of particulate, humus and resistant fractions of soil organic carbon in reforested lands using infrared spectroscopy.

    Science.gov (United States)

    Madhavan, Dinesh B; Baldock, Jeff A; Read, Zoe J; Murphy, Simon C; Cunningham, Shaun C; Perring, Michael P; Herrmann, Tim; Lewis, Tom; Cavagnaro, Timothy R; England, Jacqueline R; Paul, Keryn I; Weston, Christopher J; Baker, Thomas G

    2017-05-15

    Reforestation of agricultural lands with mixed-species environmental plantings can effectively sequester C. While accurate and efficient methods for predicting soil organic C content and composition have recently been developed for soils under agricultural land uses, such methods under forested land uses are currently lacking. This study aimed to develop a method using infrared spectroscopy for accurately predicting total organic C (TOC) and its fractions (particulate, POC; humus, HOC; and resistant, ROC organic C) in soils under environmental plantings. Soils were collected from 117 paired agricultural-reforestation sites across Australia. TOC fractions were determined in a subset of 38 reforested soils using physical fractionation by automated wet-sieving and 13C nuclear magnetic resonance (NMR) spectroscopy. Mid- and near-infrared spectra (MNIRS, 6000-450 cm-1) were acquired from finely-ground soils from environmental plantings and agricultural land. Satisfactory prediction models based on MNIRS and partial least squares regression (PLSR) were developed for TOC and its fractions. Leave-one-out cross-validations of MNIRS-PLSR models indicated accurate predictions (R2 > 0.90, negligible bias, ratio of performance to deviation > 3) and fraction-specific functional group contributions to beta coefficients in the models. TOC and its fractions were predicted using the cross-validated models and soil spectra for 3109 reforested and agricultural soils. The reliability of predictions determined using k-nearest neighbour score distance indicated that >80% of predictions were within the satisfactory inlier limit. The study demonstrated the utility of infrared spectroscopy (MNIRS-PLSR) to rapidly and economically determine TOC and its fractions and thereby accurately describe the effects of land use change such as reforestation on agricultural soils. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. A hybrid approach for predicting the distribution of vibro-acoustic energy in complex built-up structures.

    Science.gov (United States)

    Maksimov, Dmitrii N; Tanner, Gregor

    2011-09-01

    Finding the distribution of vibro-acoustic energy in complex built-up structures in the mid-to-high frequency regime is a difficult task. In particular, structures with large variation of local wavelengths and/or characteristic scales pose a challenge referred to as the mid-frequency problem. Standard numerical methods such as the finite element method (FEM) scale with the local wavelength and quickly become too large even for modern computer architectures. High frequency techniques, such as statistical energy analysis (SEA), often miss important information such as dominant resonance behavior due to stiff or small scale parts of the structure. Hybrid methods circumvent this problem by coupling FEM/BEM and SEA models in a given built-up structure. In the approach adopted here, the whole system is split into a number of subsystems that are treated by either FEM or SEA depending on the local wavelength. Subsystems with relative long wavelengths are modeled using FEM. Making a diffuse field assumption for the wave fields in the short wave length components, the coupling between subsystems can be reduced to a weighted random field correlation function. The approach presented results in an SEA-like set of linear equations that can be solved for the mean energies in the short wavelength subsystems. © 2011 Acoustical Society of America

  3. Radiation dose to the tongue and velopharynx predicts acoustic-articulatory changes after chemo-IMRT treatment for advanced head and neck cancer.

    Science.gov (United States)

    Jacobi, Irene; Navran, Arash; van der Molen, Lisette; Heemsbergen, Wilma D; Hilgers, Frans J M; van den Brekel, Michiel W M

    2016-02-01

    The aim of this study was to investigate to what extent changes in speech after C-IMRT treatment are related to mean doses to the tongue and velopharynx (VP). In 34 patients with advanced hypopharyngeal, nasopharyngeal, or oropharyngeal cancer, changes in speech from pretreatment to 10 weeks and 1 year posttreatment were correlated with mean doses to the base of tongue (BOT), oral cavity (OC) and tonsillar fossa/soft palate (VP). Differences in anteroposterior tongue position, dorsoventral degree of tongue to palate or pharynx constriction, grooving, strength, nasality, and laryngeal rise, were assessed by acoustic changes in three speech sounds that depend on a (post-) alveolar closure or narrowing (/t/, /s/, /z/), three with a tongue to palate/pharyngeal narrowing (/l/, /r/, /u/), and in vowel /a/ at comfortable and highest pitch. Acoustically assessed changes in tongue positioning, shape, velopharyngeal constriction, and laryngeal elevation were significantly related to mean doses to the tongue and velopharynx. The mean dose to BOT predicted changes in anteroposterior tongue positioning from pre- to 10-weeks posttreatment. From pretreatment to 1-year, mean doses to BOT, OC, and VP were related to changes in grooving, strength, laryngeal height, nasality, palatalization, and degree of pharyngeal constriction. Changes in speech are related to mean doses to the base of tongue and velopharynx. The outcome indicates that strength, motility, and the balance between agonist and antagonist muscle forces change significantly after radiotherapy.

  4. Rapid Prediction of Bacterial Heterotrophic Fluxomics Using Machine Learning and Constraint Programming.

    Directory of Open Access Journals (Sweden)

    Stephen Gang Wu

    2016-04-01

    Full Text Available 13C metabolic flux analysis (13C-MFA has been widely used to measure in vivo enzyme reaction rates (i.e., metabolic flux in microorganisms. Mining the relationship between environmental and genetic factors and metabolic fluxes hidden in existing fluxomic data will lead to predictive models that can significantly accelerate flux quantification. In this paper, we present a web-based platform MFlux (http://mflux.org that predicts the bacterial central metabolism via machine learning, leveraging data from approximately 100 13C-MFA papers on heterotrophic bacterial metabolisms. Three machine learning methods, namely Support Vector Machine (SVM, k-Nearest Neighbors (k-NN, and Decision Tree, were employed to study the sophisticated relationship between influential factors and metabolic fluxes. We performed a grid search of the best parameter set for each algorithm and verified their performance through 10-fold cross validations. SVM yields the highest accuracy among all three algorithms. Further, we employed quadratic programming to adjust flux profiles to satisfy stoichiometric constraints. Multiple case studies have shown that MFlux can reasonably predict fluxomes as a function of bacterial species, substrate types, growth rate, oxygen conditions, and cultivation methods. Due to the interest of studying model organism under particular carbon sources, bias of fluxome in the dataset may limit the applicability of machine learning models. This problem can be resolved after more papers on 13C-MFA are published for non-model species.

  5. Rapid Prediction of Damage to Struck and Striking Vessels in a Collision Event

    DEFF Research Database (Denmark)

    Lützen, Marie; Simonsen, Bo Cerup; Pedersen, Preben Terndrup

    2000-01-01

    This paper presents theory and application examples of a mathematical model for rapid prediciton of damage to both the side structure of a struck vessel and the bow of a striking vessel in a collision event.The geometry of the bow of the striking ship is idealised such that it can be described...... by only few parameters, still covering with sufficient accuracy almost all existing ship bows with and without bulbs.The model for the internal mechanics of the struck ship side is based on a set of so-called superelements. Each super-element represents an assembly of structural components and contains...... solutions for the structural behaviour of this assembly under deep collapse. By suming up the crushing force of each super-element, it is possible to determine the total contact load between the two involved ships.A number of parameter studies are presented where the sensitivity of the damage to the loading...

  6. 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.

  7. Predicting rapid DUI recidivism using the Driver Risk Inventory on a state-wide sample of Floridian DUI offenders.

    Science.gov (United States)

    Bishop, Nicholas J

    2011-11-01

    This project examined the ability of the popular DUI/DWI offender assessment instrument, the Driver Risk Inventory (DRI; Behavior Data Systems, Ltd., 1985), to identify short-term DUI recidivists in a sample of Floridian DUI offenders who were charged with DUI between January 1st, 2008 and December 31st, 2009. The DRI provides a number of behavioral risk scales, DSM-IV substance abuse and dependence classifications, as well as measurement of demographic and criminal history characteristics. Cox proportional hazards models were used to identify the demographic, criminal history, and behavioral characteristics most closely associated with the risk of rapid DUI recidivism. Follow-up analyses including ROC curves were used to further examine the ability of the DRI to identify short-term DUI recidivists. In the final model controlling for all variables, the DRI driver risk scale was the single strongest predictor of rapid DUI recidivism. The DSM-IV substance abuse and dependence classifications were also significant predictors of DUI recidivism. A number of the DRI risk scales and the DSM-IV classifications exhibited significant predictive validity and exhibited sensitivity in identifying recidivists similar to other popular DUI offender assessment instruments. The DRI provides useful identification of DUI recidivists in a sample able to capture only the most rapid DUI recidivists. The results of this research warrant further examination of the DRI's ability to identify DUI recidivists using longer intervals of time between DUI arrests. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  8. Rapid test for lung maturity, based on spectroscopy of gastric aspirate, predicted respiratory distress syndrome with high sensitivity

    DEFF Research Database (Denmark)

    Verder, Henrik; Heiring, Christian; Clark, Howard

    2017-01-01

    AIM: Respiratory distress syndrome (RDS) is a major cause of mortality and morbidity in premature infants. By the time symptoms appear, it may already be too late to prevent a severe course, with bronchopulmonary dysplasia or mortality. We aimed to develop a rapid test of lung maturity for target......AIM: Respiratory distress syndrome (RDS) is a major cause of mortality and morbidity in premature infants. By the time symptoms appear, it may already be too late to prevent a severe course, with bronchopulmonary dysplasia or mortality. We aimed to develop a rapid test of lung maturity......: An L/S algorithm was developed based on 89 aspirates. Subsequently, gastric aspirates were sampled in 136 infants of 24-31 weeks of gestation and 61 (45%) developed RDS. The cut-off value of L/S was 2.2, sensitivity was 92%, and specificity was 73%. In 59 cases, the oropharyngeal secretions had less...... valid L/S than gastric aspirate results. CONCLUSION: Our rapid test for lung maturity, based on spectroscopy of gastric aspirate, predicted RDS with high sensitivity....

  9. 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

  10. Using Bayesian Belief Network (BBN) modelling for Rapid Source Term Prediction. RASTEP Phase 1

    Energy Technology Data Exchange (ETDEWEB)

    Knochenhauer, M.; Swaling, V.H.; Alfheim, P. [Scandpower AB, Sundbyberg (Sweden)

    2012-09-15

    The project is connected to the development of RASTEP, a computerized source term prediction tool aimed at providing a basis for improving off-site emergency management. RASTEP uses Bayesian belief networks (BBN) to model severe accident progression in a nuclear power plant in combination with pre-calculated source terms (i.e., amount, timing, and pathway of released radio-nuclides). The output is a set of possible source terms with associated probabilities. In the NKS project, a number of complex issues associated with the integration of probabilistic and deterministic analyses are addressed. This includes issues related to the method for estimating source terms, signal validation, and sensitivity analysis. One major task within Phase 1 of the project addressed the problem of how to make the source term module flexible enough to give reliable and valid output throughout the accident scenario. Of the alternatives evaluated, it is recommended that RASTEP is connected to a fast running source term prediction code, e.g., MARS, with a possibility of updating source terms based on real-time observations. (Author)

  11. 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.

  12. Presenting Symptoms and Dysphagia Screen Predict Outcome in Mild and Rapidly Improving Acute Ischemic Stroke Patients.

    Science.gov (United States)

    Gadodia, Gaurav; Rizk, Nibal; Camp, Deborah; Bryant, Katja; Zimmerman, Susan; Brasher, Cynthia; Connelly, Kerrin; Dunn, Joshua; Frankel, Michael; Ido, Moges Seymour; Lugtu, James; Nahab, Fadi

    2016-12-01

    There are limited data on which patients not treated with intravenous (IV) tissue-type plasminogen activator (tPA) due to mild and rapidly improving stroke symptoms (MaRISS) have unfavorable outcomes. Acute ischemic stroke (AIS) patients not treated with IV tPA due to MaRISS from January 1, 2009 to December 31, 2013 were identified as part of the Georgia Coverdell Acute Stroke Registry. Multivariable regression analysis was used to identify factors associated with a lower likelihood of favorable outcome, defined as discharge to home. There were 1614 AIS patients who did not receive IV tPA due to MaRISS (median National Institutes of Health stroke scale [NIHSS] 1], of which 305 (19%) did not have a favorable outcome. Factors associated with lower likelihood of favorable outcome included Medicare insurance status (odds ratio [OR]: .53, 95% confidence interval [CI]: .34-.84), arrival by emergency medical services (OR: .46, 95% CI: .29-.73), increasing NIHSS score (per unit OR: .89, 95% CI: .84-.93), weakness as the presenting symptom (OR: .50, 95% CI: .30-.84), and a failed dysphagia screen (OR: .43, 95% CI: .23-.80). During the study period, dysphagia screen identify a subgroup of patients who are more likely to have an unfavorable outcome. Whether IV tPA treatment can improve the outcome in this subgroup of patients needs to be evaluated in a randomized placebo-controlled trial. Copyright © 2016 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  13. Influence of Architectural Features and Styles on Various Acoustical Measures in Churches

    Science.gov (United States)

    Carvalho, Antonio Pedro Oliveira De.

    This work reports on acoustical field measurements made in a major survey of 41 Catholic churches in Portugal that were built in the last 14 centuries. A series of monaural and binaural acoustical measurements was taken at multiple source/receiver positions in each church using the impulse response with noise burst method. The acoustical measures were Reverberation Time (RT), Early Decay Time (EDT), Clarity (C80), Definition (D), Center Time (TS), Loudness (L), Bass Ratios based on the Reverberation Time and Loudness rm (BR_-RT and rm BR_-L), Rapid Speech Transmission Index (RASTI), and the binaural Coherence (COH). The scope of this research is to investigate how the acoustical performance of Catholic churches relates to their architectural features and to determine simple formulas to predict acoustical measures by the use of elementary architectural parameters. Prediction equations were defined among the acoustical measures to estimate values at individual locations within each room as well as the mean values in each church. Best fits with rm R^2~0.9 were not uncommon among many of the measures. Within and interchurch differences in the data for the acoustical measures were also analyzed. The variations of RT and EDT were identified as much smaller than the variations of the other measures. The churches tested were grouped in eight architectural styles, and the effect of their evolution through time on these acoustical measures was investigated. Statistically significant differences were found regarding some architectural styles that can be traced to historical changes in Church history, especially to the Reformation period. Prediction equations were defined to estimate mean acoustical measures by the use of fifteen simple architectural parameters. The use of the Sabine and Eyring reverberation time equations was tested. The effect of coupled spaces was analyzed, and a new algorithm for the application of the Sabine equation was developed, achieving an average of

  14. Firmness prediction in Prunus persica 'Calrico' peaches by visible/short-wave near infrared spectroscopy and acoustic measurements using optimised linear and non-linear chemometric models.

    Science.gov (United States)

    Lafuente, Victoria; Herrera, Luis J; Pérez, María del Mar; Val, Jesús; Negueruela, Ignacio

    2015-08-15

    In this work, near infrared spectroscopy (NIR) and an acoustic measure (AWETA) (two non-destructive methods) were applied in Prunus persica fruit 'Calrico' (n = 260) to predict Magness-Taylor (MT) firmness. Separate and combined use of these measures was evaluated and compared using partial least squares (PLS) and least squares support vector machine (LS-SVM) regression methods. Also, a mutual-information-based variable selection method, seeking to find the most significant variables to produce optimal accuracy of the regression models, was applied to a joint set of variables (NIR wavelengths and AWETA measure). The newly proposed combined NIR-AWETA model gave good values of the determination coefficient (R(2)) for PLS and LS-SVM methods (0.77 and 0.78, respectively), improving the reliability of MT firmness prediction in comparison with separate NIR and AWETA predictions. The three variables selected by the variable selection method (AWETA measure plus NIR wavelengths 675 and 697 nm) achieved R(2) values 0.76 and 0.77, PLS and LS-SVM. These results indicated that the proposed mutual-information-based variable selection algorithm was a powerful tool for the selection of the most relevant variables. © 2014 Society of Chemical Industry.

  15. Absorption boundary conditions for geomertical acoustics

    DEFF Research Database (Denmark)

    Jeong, Cheol-Ho

    2012-01-01

    Defining accurate acoustical boundary conditions is of crucial importance for room acoustic simulations. In predicting sound fields using phased geometrical acoustics methods, the absorption coefficients or surface impedances of the boundary surfaces can be used, but no guideline has been developed...... solutions. Two rectangular rooms with uniform and non-uniform absorption distributions are tested. It is concluded that the impedance and random incidence absorption boundary conditions produce reasonable results with some exceptions at low frequencies for acoustically soft materials....

  16. A smartphone app and analysis framework for rapidly characterizing and predicting shorebird habitat

    Science.gov (United States)

    Thieler, E. R.; Zeigler, S. L.; Plant, N. G.; Gutierrez, B.; Winslow, L. A.; Hines, M. K.; Read, J. S.; Walker, J. I.

    2016-12-01

    We developed a smartphone application called iPlover as a distributed data collection system to gather synoptic observations of shorebird habitat selection preferences, and a Bayesian network that exploits the data to predict habitat suitability. We tested this approach to modeling habitat suitability for the federally listed piping plover (Charadrius melodus) on coastal beaches and barrier islands along 1500 km of coast from North Carolina to Maine, USA. Using agile software development approaches, the iPlover application was conceived, developed and deployed in just a few months following Hurricane Sandy in 2012. This application supported collaborative efforts of nearly 100 stakeholders, resulting in over 2000 data points describing piping plover habitat selection patterns. The data were analyzed in a Bayesian network to evaluate the probability that a specific combination of habitat variables is associated with a nesting site. Subsequent testing shows that iPlover data are robust to variability in user classification and that the Bayesian network has a high level of predictive accuracy. Our work addresses a variety of scientific problems in understanding and managing dynamic coastal landscapes for beach-dependent species that require biological and geological data that (1) span the range of relevant environments and habitats, (2) can be updated seasonally to interannually, and (3) capture spatial detail. It is difficult to acquire such data; the data often have limited focus due to resource constraints, can be challenging to coordinate between different regions, are collected by non-specialists, or lack observational uniformity. Furthermore, associated data analysis techniques are often limited in their ability to consider new information as data are collected from additional study sites and updated. We present examples of how this approach can be used to map past, present, and future habitat suitability for sites of interest. We also describe lessons learned

  17. A hybrid predictive model for acoustic noise in urban areas based on time series analysis and artificial neural network

    Science.gov (United States)

    Guarnaccia, Claudio; Quartieri, Joseph; Tepedino, Carmine

    2017-06-01

    The dangerous effect of noise on human health is well known. Both the auditory and non-auditory effects are largely documented in literature, and represent an important hazard in human activities. Particular care is devoted to road traffic noise, since it is growing according to the growth of residential, industrial and commercial areas. For these reasons, it is important to develop effective models able to predict the noise in a certain area. In this paper, a hybrid predictive model is presented. The model is based on the mixing of two different approach: the Time Series Analysis (TSA) and the Artificial Neural Network (ANN). The TSA model is based on the evaluation of trend and seasonality in the data, while the ANN model is based on the capacity of the network to "learn" the behavior of the data. The mixed approach will consist in the evaluation of noise levels by means of TSA and, once the differences (residuals) between TSA estimations and observed data have been calculated, in the training of a ANN on the residuals. This hybrid model will exploit interesting features and results, with a significant variation related to the number of steps forward in the prediction. It will be shown that the best results, in terms of prediction, are achieved predicting one step ahead in the future. Anyway, a 7 days prediction can be performed, with a slightly greater error, but offering a larger range of prediction, with respect to the single day ahead predictive model.

  18. Underwater Acoustic Carbon Nanotube Thermophone

    Science.gov (United States)

    2016-09-23

    the generation of electrical excitation pulsed through an amplifier into an electro-acoustic material (such as a piezoelectric ceramic ...strength. This periodic heating produces temperature waves which propagate into a surrounding medium. The amplitude of the temperature wave ...decreases rapidly as the distance from the conductor increases. Based on the rapid production of these temperature waves ; the net effect is to produce a

  19. Musical Acoustics

    Science.gov (United States)

    Gough, Colin

    This chapter provides an introduction to the physical and psycho-acoustic principles underlying the production and perception of the sounds of musical instruments. The first section introduces generic aspects of musical acoustics and the perception of musical sounds, followed by separate sections on string, wind and percussion instruments.

  20. Prediction of Beck Depression Inventory (BDI-II) Score Using Acoustic Measurements in a Sample of Iium Engineering Students

    Science.gov (United States)

    Fikri Zanil, Muhamad; Nur Wahidah Nik Hashim, Nik; Azam, Huda

    2017-11-01

    Psychiatrist currently relies on questionnaires and interviews for psychological assessment. These conservative methods often miss true positives and might lead to death, especially in cases where a patient might be experiencing suicidal predisposition but was only diagnosed as major depressive disorder (MDD). With modern technology, an assessment tool might aid psychiatrist with a more accurate diagnosis and thus hope to reduce casualty. This project will explore on the relationship between speech features of spoken audio signal (reading) in Bahasa Malaysia with the Beck Depression Inventory scores. The speech features used in this project were Power Spectral Density (PSD), Mel-frequency Ceptral Coefficients (MFCC), Transition Parameter, formant and pitch. According to analysis, the optimum combination of speech features to predict BDI-II scores include PSD, MFCC and Transition Parameters. The linear regression approach with sequential forward/backward method was used to predict the BDI-II scores using reading speech. The result showed 0.4096 mean absolute error (MAE) for female reading speech. For male, the BDI-II scores successfully predicted 100% less than 1 scores difference with MAE of 0.098437. A prediction system called Depression Severity Evaluator (DSE) was developed. The DSE managed to predict one out of five subjects. Although the prediction rate was low, the system precisely predict the score within the maximum difference of 4.93 for each person. This demonstrates that the scores are not random numbers.

  1. Rapidly updated hyperspectral sounding and imaging data for severe storm prediction

    Science.gov (United States)

    Bingham, Gail; Jensen, Scott; Elwell, John; Cardon, Joel; Crain, David; Huang, Hung-Lung (Allen); Smith, William L.; Revercomb, Hank E.; Huppi, Ronald J.

    2013-09-01

    Several studies have shown that a geostationary hyperspectral imager/sounder can provide the most significant value increase in short term, regional numerical prediction weather models over a range of other options. In 1998, the Geostationary Imaging Fourier Transform Spectrometer (GIFTS) proposal was selected by NASA as the New Millennium Earth Observation 3 program over several other geostationary instrument development proposals. After the EO3 GIFTS flight demonstration program was changed to an Engineering Development Unit (EDU) due to funding limitations by one of the partners, the EDU was subjected to flight-like thermal vacuum calibration and testing and successfully validated the breakthrough technologies needed to make a successful observatory. After several government stops and starts, only EUMETSAT's Meteosat Third Generation (MTG-S) sounder is in operational development. Recently, a commercial partnership has been formed to fill the significant data gap. AsiaSat has partnered with GeoMetWatch (GMW)1 to fund the development and launch of the Sounding and Tracking Observatory for Regional Meteorology (STORMTM) sensor, a derivative of the Geosynchronous Imaging Fourier Transform Spectrometer (GIFTS) EDU that was designed, built, and tested by Utah State University (USU). STORMTM combines advanced technologies to observe surface thermal properties, atmospheric weather, and chemistry variables in four dimensions to provide high vertical resolution temperature and moisture sounding information, with the fourth dimension (time) provided by the geosynchronous satellite platform ability to measure a location as often as desired. STORMTM will enhance the polar orbiting imaging and sounding measurements by providing: (1) a direct measure of moisture flux and altitude-resolved water vapor and cloud tracer winds throughout the troposphere, (2) an observation of the time varying atmospheric thermodynamics associated with storm system development, and (3) the

  2. 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...... chapters represent review articles covering the most relevant areas of the field. They are written with the goal of providing students with comprehensive introductions. Further they offer a supply of numerous references to the relevant literature. Besides its usefulness as a textbook, this will make...... 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...

  3. Identification of a Critical Time with Acoustic Emission Monitoring during Static Fatigue Tests on Ceramic Matrix Composites: Towards Lifetime Prediction

    Directory of Open Access Journals (Sweden)

    Nathalie Godin

    2016-02-01

    Full Text Available Non-oxide fiber-reinforced ceramic-matrix composites are promising candidates for some aeronautic applications that require good thermomechanical behavior over long periods of time. This study focuses on the behavior of a SiCf/[Si-B-C] composite with a self-healing matrix at intermediate temperature under air. Static fatigue experiments were performed below 600 °C and a lifetime diagram is presented. Damage is monitored both by strain measurement and acoustic emission during the static fatigue experiments. Two methods of real-time analysis of associated energy release have been developed. They allow for the identification of a characteristic time that was found to be close to 55% of the measured rupture time. This critical time reflects a critical local energy release assessed by the applicability of the Benioff law. This critical aspect is linked to a damage phase where slow crack growth in fibers is prevailing leading to ultimate fracture of the composite.

  4. The performance of matrices in daily clinical practice to predict rapid radiologic progression in patients with early RA.

    Science.gov (United States)

    De Cock, D; Vanderschueren, G; Meyfroidt, S; Joly, J; Van der Elst, K; Westhovens, R; Verschueren, P

    2014-04-01

    To compare in daily clinical practice the reliability of matrices that forecast rapid radiologic progression (RRP) at year one, at year two, and over 2 years in patients with early rheumatoid arthritis (RA). Overall, 74 early RA patients with X-rays of hands and feet at baseline, year one, and year two were included. Initial DMARD combination therapy with steroids (ICTS) or DMARD monotherapy (IMT) was initiated according to patients' RA severity, based on rheumatologist opinion. The images were scored via the modified Sharp/van der Heijde (SvH) method. A total Sharp score progression of equal or higher than five per year was considered RRP. Six matrices were tested: ASPIRE CRP/ESR matrices, the BEST matrix, two SWEFOT matrices, and the ESPOIR matrix. Patients were placed in each of them yielding a RRP probability. The performance was tested by Area Under the Curve analysis reflecting the predictive value. Four patients developed RRP in year one, five in year two, and four over 2 years. With regard to face validity, the predicted probability did not correspond to the risk in reality: the one ICTS patient who developed RRP over 2 years was always found in the lowest RRP categories of all matrices. The ASPIRE CRP matrix yielded at least a moderate predicting value for the three time points. The other matrices showed moderate to no predicting value. The performance of all matrices was disappointing and it is impossible to fully rely on the existing matrices in daily clinical practice. © 2013 Published by Elsevier Inc.

  5. Rapid characterisation of vegetation structure to predict refugia and climate change impacts across a global biodiversity hotspot.

    Directory of Open Access Journals (Sweden)

    Antonius G T Schut

    Full Text Available Identification of refugia is an increasingly important adaptation strategy in conservation planning under rapid anthropogenic climate change. Granite outcrops (GOs provide extraordinary diversity, including a wide range of taxa, vegetation types and habitats in the Southwest Australian Floristic Region (SWAFR. However, poor characterization of GOs limits the capacity of conservation planning for refugia under climate change. A novel means for the rapid identification of potential refugia is presented, based on the assessment of local-scale environment and vegetation structure in a wider region. This approach was tested on GOs across the SWAFR. Airborne discrete return Light Detection And Ranging (LiDAR data and Red Green and Blue (RGB imagery were acquired. Vertical vegetation profiles were used to derive 54 structural classes. Structural vegetation types were described in three areas for supervised classification of a further 13 GOs across the region. Habitat descriptions based on 494 vegetation plots on and around these GOs were used to quantify relationships between environmental variables, ground cover and canopy height. The vegetation surrounding GOs is strongly related to structural vegetation types (Kappa = 0.8 and to its spatial context. Water gaining sites around GOs are characterized by taller and denser vegetation in all areas. The strong relationship between rainfall, soil-depth, and vegetation structure (R(2 of 0.8-0.9 allowed comparisons of vegetation structure between current and future climate. Significant shifts in vegetation structural types were predicted and mapped for future climates. Water gaining areas below granite outcrops were identified as important putative refugia. A reduction in rainfall may be offset by the occurrence of deeper soil elsewhere on the outcrop. However, climate change interactions with fire and water table declines may render our conclusions conservative. The LiDAR-based mapping approach presented

  6. An in vitro transport model for rapid screening and predicting the permeability of candidate compounds at blood-brain barrier.

    Science.gov (United States)

    Yang, Zhi-Hong; Sun, Xiao; Mei, Chao; Sun, Xiao-Bo; Liu, Xiao-Dong; Chang, Qi

    2011-12-01

    The aim of this study was to design and develop a simple in vitro blood-brain barrier (BBB) permeation model for elementarily and rapidly predicting the permeability of candidate compounds at BBB and further evaluating whether P-glycoprotein (P-gp) affects them across BBB. The model was mainly composed of cultured rat brain microvascular endothelial cells (rBMECs), glass contraption, and micropore membrane. First, we evaluated the model by morphological observation. Second, the restriction effects of paracellular transport were verified by measuring marker probes transport, and monitoring transendothelial electrical resistance (TEER) and leakage. Finally, protein expression and activity of P-gp were confirmed by carrying out Western blot analysis and polarized transport of rhodamine-123 (Rho123) in rBMECs. The rBMECs retained both endothelial cells and BBB features. The rBMECs model reproducibly attained approximately 130 Ω cm² on the steady-state TEER value, and displayed a barrier function to marker probes transport by decreasing the permeability. Protein band of 170 kDa manifested the existence of P-gp in the rBMECs, and the findings of cyclosporin A-sensitive decrease of Rho123 efflux confirmed the presence of P-gp activity. A simple, rapid, and convenient in vitro BBB permeation model was successfully established and applied to evaluate the BBB transport profiles of three natural flavonoids: quercetin, naringenin, and rutin.

  7. Acoustics Research of Propulsion Systems

    Science.gov (United States)

    Gao, Ximing; Houston, Janice

    2014-01-01

    The liftoff phase induces high acoustic loading over a broad frequency range for a launch vehicle. These external acoustic environments are used in the prediction of the internal vibration responses of the vehicle and components. Present liftoff vehicle acoustic environment prediction methods utilize stationary data from previously conducted hold-down tests to generate 1/3 octave band Sound Pressure Level (SPL) spectra. In an effort to update the accuracy and quality of liftoff acoustic loading predictions, non-stationary flight data from the Ares I-X were processed in PC-Signal in two flight phases: simulated hold-down and liftoff. In conjunction, the Prediction of Acoustic Vehicle Environments (PAVE) program was developed in MATLAB to allow for efficient predictions of sound pressure levels (SPLs) as a function of station number along the vehicle using semi-empirical methods. This consisted of generating the Dimensionless Spectrum Function (DSF) and Dimensionless Source Location (DSL) curves from the Ares I-X flight data. These are then used in the MATLAB program to generate the 1/3 octave band SPL spectra. Concluding results show major differences in SPLs between the hold-down test data and the processed Ares I-X flight data making the Ares I-X flight data more practical for future vehicle acoustic environment predictions.

  8. Rinometria acústica em crianças submetidas à disjunção maxilar Acoustic rhinometry in children undergoing a rapid maxillary expansion

    Directory of Open Access Journals (Sweden)

    Mario Cappellette Jr.

    2006-04-01

    Full Text Available OBJETIVO: este estudo foi realizado na Disciplina de Otorrinolaringologia Pediátrica da Escola Paulista de Medicina - UNIFESP, com o objetivo de verificar o comportamento da disjunção maxilar e sua influência na cavidade nasal em crianças de 7 a 8 anos de idade submetidas à rinometria acústica. METODOLOGIA: foram avaliadas 20 crianças respiradoras bucais, portadoras de atresia maxilar diagnosticada clinicamente e submetidas à avaliação objetiva da cavidade nasal pré-disjunção maxilar e pós-disjunção maxilar por meio de rinometria acústica, analisando-se os resultados das áreas transversais mínimas (MCA1 e MCA2 e volumes nasais (VOL1 e VOL2. RESULTADOS: os resultados de MCA1 e MCA2 pré-disjunção maxilar apresentaram-se menores que os valores de MCA1 e MCA2 pós-disjunção maxilar do lado esquerdo; à direita, a MCA1 pré-disjunção maxilar mostrou-se menor que a MCA1 pós-disjunção maxilar, aumentos estes estatisticamente significantes, já os VOL1 e VOL2 pré-disjunção foram menores que o VOL1 e VOL2 pós-disjunção maxilar em ambos os lados, ou seja, os resultados desta diferença foram estatisticamente significantes. CONCLUSÃO: a rinometria acústica é um método objetivo para avaliar a variação da cavidade nasal. A disjunção maxilar promove um aumento significante da área e volume da cavidade nasal.AIM: this research study was carried out by professionals of the Paulista School of Medicine - UNIFESP and it relates to the Pediatric Otorhinolaryngology subject. The current study aimed at checking the behaviour of the maxillary dysjunction and its influence in the nasal cavity of children between 7 and 8 years of age who underwent acoustic rhinometry. METHODS: 20 mouth-breathing subjects presenting maxillary atresia diagnosed clinically were evaluated. Subjects underwent objective evaluation of the nasal cavity before and after maxillary dysjunction by means of acoustic rhinometry. Results of the minimal

  9. Cephalometric variables used to predict the success of interceptive treatment with rapid maxillary expansion and face mask. A longitudinal study

    Directory of Open Access Journals (Sweden)

    Daniele Nóbrega Nardoni

    2015-02-01

    Full Text Available INTRODUCTION: Prognosis is the main limitation of interceptive treatment of Class III malocclusions. The interceptive procedures of rapid maxillary expansion (RME and face mask therapy performed in early mixed dentition are capable of achieving immediate overcorrection and maintenance of facial and occlusal morphology for a few years. Individuals presenting minimal acceptable faces at growth completion are potential candidates for compensatory orthodontic treatment, while those with facial involvement should be submitted to orthodontic decompensation for orthognathic surgery. OBJECTIVES: To investigate cephalometric variables that might predict the outcomes of orthopedic treatment with RME and face mask therapy (FM. METHODS: Cephalometric analysis of 26 Class III patients (mean age of 8 years and 4 months was performed at treatment onset and after a mean period of 6 years and 10 months at pubertal growth completion, including a subjective facial analysis. Patients was divided into two groups: success group (21 individuals and failure group (5 individuals. Discriminant analysis was applied to the cephalometric values at treatment onset. Two predictor variables were found by stepwise procedure. RESULTS: Orthopedic treatment of Class III malocclusion may have unfavorable prognosis at growth completion whenever initial cephalometric analysis reveals increased lower anterior facial height (LAFH combined with reduced angle between the condylar axis and the mandibular plane (CondAx.MP. CONCLUSION: The results of treatment with RME and face mask therapy at growth completion in Class III patients could be predicted with a probability of 88.5%.

  10. Chemotherapy of colorectal liver metastases induces a rapid rise in intermediate blood monocytes which predicts treatment response

    Science.gov (United States)

    Schauer, Dominic; Starlinger, Patrick; Alidzanovic, Lejla; Zajc, Philipp; Maier, Thomas; Feldman, Alexandra; Padickakudy, Robin; Buchberger, Elisabeth; Elleder, Vanessa; Spittler, Andreas; Stift, Judith; Pop, Lorand; Gruenberger, Birgit; Gruenberger, Thomas; Brostjan, Christine

    2016-01-01

    ABSTRACT We have previously reported that intermediate monocytes (CD14++/CD16+) were increased in colorectal cancer (CRC) patients, while the subset of pro-angiogenic TIE2-expressing monocytes (TEMs) was not significantly elevated. This study was designed to evaluate changes in frequency and function of intermediate monocytes and TEMs during chemotherapy and anti-angiogenic cancer treatment and their relation to treatment response. Monocyte populations were determined by flow cytometry in 60 metastasized CRC (mCRC) patients who received neoadjuvant chemotherapy with or without bevacizumab. Blood samples were taken before treatment, after two therapy cycles, at the end of neoadjuvant therapy and immediately before surgical resection of liver metastases. Neoadjuvant treatment resulted in a significant increase in circulating intermediate monocytes which was most pronounced after two cycles and positively predicted tumor response (AUC = 0.875, p = 0.005). With a cut-off value set to 1% intermediate monocytes of leukocytes, this parameter showed a predictive sensitivity and specificity of 75% and 88%. Anti-angiogenic therapy with bevacizumab had no impact on monocyte populations including TEMs. In 15 patients and six healthy controls, the gene expression profile and the migratory behavior of monocyte subsets was evaluated. The profile of intermediate monocytes suggested functions in antigen presentation, inflammatory cytokine production, chemotaxis and was remarkably stable during chemotherapy. Intermediate monocytes showed a preferential migratory response to tumor-derived signals in vitro and correlated with the level of CD14+/CD16+ monocytic infiltrates in the resected tumor tissue. In conclusion, the rapid rise of intermediate monocytes during chemotherapy may offer a simple marker for response prediction and a timely change in regimen. PMID:27471631

  11. A comparison of supervised classification methods for the prediction of substrate type using multibeam acoustic and legacy grain-size data.

    Directory of Open Access Journals (Sweden)

    David Stephens

    Full Text Available Detailed seabed substrate maps are increasingly in demand for effective planning and management of marine ecosystems and resources. It has become common to use remotely sensed multibeam echosounder data in the form of bathymetry and acoustic backscatter in conjunction with ground-truth sampling data to inform the mapping of seabed substrates. Whilst, until recently, such data sets have typically been classified by expert interpretation, it is now obvious that more objective, faster and repeatable methods of seabed classification are required. This study compares the performances of a range of supervised classification techniques for predicting substrate type from multibeam echosounder data. The study area is located in the North Sea, off the north-east coast of England. A total of 258 ground-truth samples were classified into four substrate classes. Multibeam bathymetry and backscatter data, and a range of secondary features derived from these datasets were used in this study. Six supervised classification techniques were tested: Classification Trees, Support Vector Machines, k-Nearest Neighbour, Neural Networks, Random Forest and Naive Bayes. Each classifier was trained multiple times using different input features, including i the two primary features of bathymetry and backscatter, ii a subset of the features chosen by a feature selection process and iii all of the input features. The predictive performances of the models were validated using a separate test set of ground-truth samples. The statistical significance of model performances relative to a simple baseline model (Nearest Neighbour predictions on bathymetry and backscatter were tested to assess the benefits of using more sophisticated approaches. The best performing models were tree based methods and Naive Bayes which achieved accuracies of around 0.8 and kappa coefficients of up to 0.5 on the test set. The models that used all input features didn't generally perform well

  12. 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....

  13. 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.

  14. 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...

  15. Acoustic Neuroma

    Science.gov (United States)

    ... in June 1969 at Karolinska Hospital in Stockholm, Sweden. Since then, more than 10,000 acoustic neuroma ... of neurosurgeons, radiation oncologists, medical physicists and a nursing staff. Specialists in neuroimaging join the team when ...

  16. 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...

  17. Anisotropic and Negative Acoustic Index Metamaterials

    OpenAIRE

    Fok, Lee Ren

    2010-01-01

    Microstructured materials are used in material science and engineering to attain desired material properties. Acoustic metamaterials are a rapidly growing area in this field of engineered materials that use deep subwavelength microstructures to attain exotic acoustic properties unavailable in nature. These properties, such as negative acoustic index, allow unprecedented capabilities such as sub-diffraction limit resolution, which have the potential to greatly improve existing technologies l...

  18. 4th Pacific Rim Underwater Acoustics Conference

    CERN Document Server

    Xu, Wen; Cheng, Qianliu; Zhao, Hangfang

    2016-01-01

    These proceedings are a collection of 16 selected scientific papers and reviews by distinguished international experts that were presented at the 4th Pacific Rim Underwater Acoustics Conference (PRUAC), held in Hangzhou, China in October 2013. The topics discussed at the conference include internal wave observation and prediction; environmental uncertainty and coupling to sound propagation; environmental noise and ocean dynamics; dynamic modeling in acoustic fields; acoustic tomography and ocean parameter estimation; time reversal and matched field processing; underwater acoustic localization and communication as well as measurement instrumentations and platforms. These proceedings provide insights into the latest developments in underwater acoustics, promoting the exchange of ideas for the benefit of future research.

  19. Fitting stress relaxation experiments with fractional Zener model to predict high frequency moduli of polymeric acoustic foams

    Science.gov (United States)

    Guo, Xinxin; Yan, Guqi; Benyahia, Lazhar; Sahraoui, Sohbi

    2016-11-01

    This paper presents a time domain method to determine viscoelastic properties of open-cell foams on a wide frequency range. This method is based on the adjustment of the stress-time relationship, obtained from relaxation tests on polymeric foams' samples under static compression, with the four fractional derivatives Zener model. The experimental relaxation function, well described by the Mittag-Leffler function, allows for straightforward prediction of the frequency-dependence of complex modulus of polyurethane foams. To show the feasibility of this approach, complex shear moduli of the same foams were measured in the frequency range between 0.1 and 16 Hz and at different temperatures between -20 °C and 20 °C. A curve was reconstructed on the reduced frequency range (0.1 Hz-1 MHz) using the time-temperature superposition principle. Very good agreement was obtained between experimental complex moduli values and the fractional Zener model predictions. The proposed time domain method may constitute an improved alternative to resonant and non-resonant techniques often used for dynamic characterization of polymers for the determination of viscoelastic moduli on a broad frequency range.

  20. Conventional US combined with acoustic radiation force impulse (ARFI) elastography for prediction of triple-negative breast cancer and the risk of lymphatic metastasis.

    Science.gov (United States)

    Pu, Huan; Zhao, Li-Xia; Yao, Ming-Hua; Xu, Guang; Liu, Hui; Xu, Hui-Xiong; Wu, Rong

    2017-01-01

    To evaluate the combination of conventional ultrasound (US) and acoustic radiation force impulse (ARFI) elastography in predicting triple-negative breast cancer and the likelihood of lymphatic metastasis. A total of 178 women presenting from May 2013 to September 2015 with pathologically proven triple-negative (n = 60) or hormone receptor (HR)-positive/human epidermal growth factor receptor 2 (HER2)-negative breast cancer (n = 118) were reviewed. Conventional US and ARFI imaging including Virtual touch tissue image (VTI) and Virtual Touch tissue Quantification (VTQ), were performed for each breast nodule. Parameters collected included patient age, lymph node involvement, histological grade, tumor subtype, appearance on conventional US, shear wave velocity (SWV) value, VTI score and the boundary on VTI. The ARFI findings were compared with the pathological findings. Younger age (P P P P = 0.001), larger tumor size (P = 0.008), regular shape (P = 0.032), high VTI score (P = 0.006), unclear VTI boundary (P = 0.033), SWV ≥3.51 m/s (P = 0.015) were significantly associated with triple-negative breast cancer. High VTI score (P = 0.004) and a high SWV ≥4.15 m/s (P = 0.002) were significantly associated with lymphatic metastasis. Conventional US combined with ARFI may be used to predict triple-negative breast cancer. Those cancers with higher SWV and the high VTI score have a higher likelihood of lymphatic metastasis.

  1. Reduced Order Model-Based Prediction of the Nonlinear Geometric Response of a Panel Under Thermal, Aerodynamic, and Acoustic Loads

    Science.gov (United States)

    Matney, Andrew

    This paper addresses some aspects of the development of fully coupled thermal-structural reduced order modeling of planned hypersonic vehicles. A general framework for the construction of the structural and thermal basis is presented and demonstrated on a representative panel considered in prior investigations. The thermal reduced order model is first developed using basis functions derived from appropriate conduction eigenvalue problems. The modal amplitudes are the solution of the governing equation, which is nonlinear due to the presence of radiation and temperature dependent capacitance and conductance matrices, and the predicted displacement field is validated using published data. A structural reduced order model was developed by first selecting normal modes of the system and then constructing associated dual modes for the capturing of nonlinear inplane displacements. This isothermal model was validated by comparison with full finite element results (Nastran) in static and dynamic loading environments. The coupling of this nonlinear structural reduced order model with the thermal reduced order model is next considered. Displacement-induced thermal modes are constructed in order to account for the effect that structural deflections will have on the thermal problem. This coupling also requires the enrichment of the structural basis to model the elastic deformations that may be produced consistently with the thermal reduced order model. The validation of the combined structural-thermal reduced order model is carried out with pure mechanical loads, pure thermal loads, and combined mechanical-thermal excitations. Such comparisons are performed here on static solutions with temperature increases up to 2200F and pressures up to 3 psi for which the maximum displacements are of the order of 3 thicknesses. The reduced order model predicted results agree well with the full order finite element predictions in all of these various cases. A fully coupled analysis was

  2. Flood Foresight: A near-real time flood monitoring and forecasting tool for rapid and predictive flood impact assessment

    Science.gov (United States)

    Revilla-Romero, Beatriz; Shelton, Kay; Wood, Elizabeth; Berry, Robert; Bevington, John; Hankin, Barry; Lewis, Gavin; Gubbin, Andrew; Griffiths, Samuel; Barnard, Paul; Pinnell, Marc; Huyck, Charles

    2017-04-01

    The hours and days immediately after a major flood event are often chaotic and confusing, with first responders rushing to mobilise emergency responders, provide alleviation assistance and assess loss to assets of interest (e.g., population, buildings or utilities). Preparations in advance of a forthcoming event are becoming increasingly important; early warning systems have been demonstrated to be useful tools for decision markers. The extent of damage, human casualties and economic loss estimates can vary greatly during an event, and the timely availability of an accurate flood extent allows emergency response and resources to be optimised, reduces impacts, and helps prioritise recovery. In the insurance sector, for example, insurers are under pressure to respond in a proactive manner to claims rather than waiting for policyholders to report losses. Even though there is a great demand for flood inundation extents and severity information in different sectors, generating flood footprints for large areas from hydraulic models in real time remains a challenge. While such footprints can be produced in real time using remote sensing, weather conditions and sensor availability limit their ability to capture every single flood event across the globe. In this session, we will present Flood Foresight (www.floodforesight.com), an operational tool developed to meet the universal requirement for rapid geographic information, before, during and after major riverine flood events. The tool provides spatial data with which users can measure their current or predicted impact from an event - at building, basin, national or continental scales. Within Flood Foresight, the Screening component uses global rainfall predictions to provide a regional- to continental-scale view of heavy rainfall events up to a week in advance, alerting the user to potentially hazardous situations relevant to them. The Forecasting component enhances the predictive suite of tools by providing a local

  3. Using artificial neural networks and model predictive control to optimize acoustically assisted Doxorubicin release from polymeric micelles.

    Science.gov (United States)

    Husseini, Ghaleb A; Mjalli, Farouq S; Pitt, William G; Abdel-Jabbar, Nabil M

    2009-12-01

    We have been developing a drug delivery system that uses Pluronic P105 micelles to sequester a chemotherapeutic drug--namely, Doxorubicin (Dox)--until it reaches the cancer site. Ultrasound is then applied to release the drug directly to the tumor and in the process minimize the adverse side effects of chemotherapy on non-tumor tissues. Here, we present an artificial neural network (ANN) model that attempts to model the dynamic release of Dox from P105 micelles under different ultrasonic power intensities at two frequencies. The developed ANN model is then utilized to optimize the ultrasound application to achieve a target drug release at the tumor site via an ANN-based model predictive control. The parameters of the controller are then tuned to achieve good reference signal tracking. We were successful in designing and testing a controller capable of adjusting the ultrasound frequency, intensity, and pulse length to sustain constant Dox release.

  4. Music of the 7Ts: Predicting and Decoding Multivoxel fMRI Responses with Acoustic, Schematic, and Categorical Music Features.

    Science.gov (United States)

    Casey, Michael A

    2017-01-01

    Underlying the experience of listening to music are parallel streams of auditory, categorical, and schematic qualia, whose representations and cortical organization remain largely unresolved. We collected high-field (7T) fMRI data in a music listening task, and analyzed the data using multivariate decoding and stimulus-encoding models. Twenty subjects participated in the experiment, which measured BOLD responses evoked by naturalistic listening to twenty-five music clips from five genres. Our first analysis applied machine classification to the multivoxel patterns that were evoked in temporal cortex. Results yielded above-chance levels for both stimulus identification and genre classification-cross-validated by holding out data from multiple of the stimuli during model training and then testing decoding performance on the held-out data. Genre model misclassifications were significantly correlated with those in a corresponding behavioral music categorization task, supporting the hypothesis that geometric properties of multivoxel pattern spaces underlie observed musical behavior. A second analysis employed a spherical searchlight regression analysis which predicted multivoxel pattern responses to music features representing melody and harmony across a large area of cortex. The resulting prediction-accuracy maps yielded significant clusters in the temporal, frontal, parietal, and occipital lobes, as well as in the parahippocampal gyrus and the cerebellum. These maps provide evidence in support of our hypothesis that geometric properties of music cognition are neurally encoded as multivoxel representational spaces. The maps also reveal a cortical topography that differentially encodes categorical and absolute-pitch information in distributed and overlapping networks, with smaller specialized regions that encode tonal music information in relative-pitch representations.

  5. Music of the 7Ts: Predicting and Decoding Multivoxel fMRI Responses with Acoustic, Schematic, and Categorical Music Features

    Directory of Open Access Journals (Sweden)

    Michael A. Casey

    2017-07-01

    Full Text Available Underlying the experience of listening to music are parallel streams of auditory, categorical, and schematic qualia, whose representations and cortical organization remain largely unresolved. We collected high-field (7T fMRI data in a music listening task, and analyzed the data using multivariate decoding and stimulus-encoding models. Twenty subjects participated in the experiment, which measured BOLD responses evoked by naturalistic listening to twenty-five music clips from five genres. Our first analysis applied machine classification to the multivoxel patterns that were evoked in temporal cortex. Results yielded above-chance levels for both stimulus identification and genre classification–cross-validated by holding out data from multiple of the stimuli during model training and then testing decoding performance on the held-out data. Genre model misclassifications were significantly correlated with those in a corresponding behavioral music categorization task, supporting the hypothesis that geometric properties of multivoxel pattern spaces underlie observed musical behavior. A second analysis employed a spherical searchlight regression analysis which predicted multivoxel pattern responses to music features representing melody and harmony across a large area of cortex. The resulting prediction-accuracy maps yielded significant clusters in the temporal, frontal, parietal, and occipital lobes, as well as in the parahippocampal gyrus and the cerebellum. These maps provide evidence in support of our hypothesis that geometric properties of music cognition are neurally encoded as multivoxel representational spaces. The maps also reveal a cortical topography that differentially encodes categorical and absolute-pitch information in distributed and overlapping networks, with smaller specialized regions that encode tonal music information in relative-pitch representations.

  6. 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. © 2016 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

  7. Acoustic Resonance Reaction Control Thruster (ARCTIC) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ORBITEC proposes to develop and demonstrate the innovative Acoustic Resonance Reaction Control Thruster (ARCTIC) to provide rapid and reliable in-space impulse...

  8. Near-infrared spectroscopy, a rapid method for predicting the age of male and female wild-type and Wolbachia infected Aedes aegypti

    Science.gov (United States)

    Estimating the age distribution of mosquito populations is crucial for assessing their capacity to transmit disease and for evaluating the efficacy of available vector control programs. This study reports on the capacity of near-infrared spectroscopy (NIRS) technique to rapidly predict the ages of t...

  9. Holograms for acoustics.

    Science.gov (United States)

    Melde, Kai; Mark, Andrew G; Qiu, Tian; Fischer, Peer

    2016-09-22

    Holographic techniques are fundamental to applications such as volumetric displays, high-density data storage and optical tweezers that require spatial control of intricate optical or acoustic fields within a three-dimensional volume. The basis of holography is spatial storage of the phase and/or amplitude profile of the desired wavefront in a manner that allows that wavefront to be reconstructed by interference when the hologram is illuminated with a suitable coherent source. Modern computer-generated holography skips the process of recording a hologram from a physical scene, and instead calculates the required phase profile before rendering it for reconstruction. In ultrasound applications, the phase profile is typically generated by discrete and independently driven ultrasound sources; however, these can only be used in small numbers, which limits the complexity or degrees of freedom that can be attained in the wavefront. Here we introduce monolithic acoustic holograms, which can reconstruct diffraction-limited acoustic pressure fields and thus arbitrary ultrasound beams. We use rapid fabrication to craft the holograms and achieve reconstruction degrees of freedom two orders of magnitude higher than commercial phased array sources. The technique is inexpensive, appropriate for both transmission and reflection elements, and scales well to higher information content, larger aperture size and higher power. The complex three-dimensional pressure and phase distributions produced by these acoustic holograms allow us to demonstrate new approaches to controlled ultrasonic manipulation of solids in water, and of liquids and solids in air. We expect that acoustic holograms will enable new capabilities in beam-steering and the contactless transfer of power, improve medical imaging, and drive new applications of ultrasound.

  10. A comparison of supervised classification methods for the prediction of substrate type using multibeam acoustic and legacy grain-size data

    National Research Council Canada - National Science Library

    Stephens, David; Diesing, Markus

    2014-01-01

    .... It has become common to use remotely sensed multibeam echosounder data in the form of bathymetry and acoustic backscatter in conjunction with ground-truth sampling data to inform the mapping of seabed substrates...

  11. Predicting Meaningful Outcomes to Medication and Self-Help Treatments for Binge Eating Disorder in Primary Care: The Significance of Early Rapid Response

    Science.gov (United States)

    Grilo, Carlos M.; White, Marney A.; Masheb, Robin M.; Gueorguieva, Ralitza

    2014-01-01

    Objective We examined rapid response among obese patients with binge-eating disorder (BED) in a randomized clinical trial testing anti-obesity medication and self-help cognitive-behavioral therapy (shCBT), alone and in combination, in primary-care settings. Method 104 obese patients with BED were randomly assigned to one of four treatments: sibutramine, placebo, shCBT+sibutramine, or shCBT+placebo. Treatments were delivered by generalist primary-care physicians and the medications were given double-blind. Independent assessments were performed by trained and monitored doctoral research-clinicians monthly throughout treatment, post-treatment (4 months), and at 6- and 12-month follow-ups (i.e., 16 months after randomization). Rapid response, defined as ≥65% reduction in binge-eating by the fourth treatment week, was used to predict outcomes. Results Rapid response characterized 47% of patients. Rapid response was unrelated to demographic and baseline clinical characteristics. Rapid response was significantly associated prospectively with remission from binge eating at post-treatment (51% versus 9% for non-rapid responders), 6-month (53% vs 23.6%), and 12-month (46.9% vs 23.6%) follow-ups. Mixed effects model analyses revealed rapid response was significantly associated with greater decreases in binge-eating, eating-disorder psychopathology, depression, and percent weight loss. Discussion Our findings, based on a diverse obese patient group receiving medication and self-help CBT treatments for BED in primary care settings, indicate that patients who have a rapid response achieve good clinical outcomes through 12-month follow-ups after ending treatments. Rapid response represents a strong prognostic indicator of clinically meaningful outcomes even in low intensity medication and self-help interventions. Rapid response has important clinical implications for stepped-care treatment models for BED. Clinical Trial Registration clinicaltrials.gov: NCT00537810 PMID

  12. Acoustic microscopy

    CERN Document Server

    Briggs, Andrew

    2010-01-01

    For many years 'Acoustic Microscopy' has been the definitive book on the subject. A key development since it was first published has been the development of ultrasonic force microscopy. This edition has a major new chapter on this technique and its applications.

  13. Subscale Acoustic Testing: Comparison of ALAT and ASMAT

    Science.gov (United States)

    Houston, Janice D.; Counter, Douglas

    2014-01-01

    The liftoff phase induces acoustic loading over a broad frequency range for a launch vehicle. These external acoustic environments are then used in the prediction of internal vibration responses of the vehicle and components which result in the qualification levels. Thus, predicting these liftoff acoustic environments is critical to the design requirements of any launch vehicle. If there is a significant amount of uncertainty in the predictions or if acoustic mitigation options must be implemented, a subscale acoustic test is a feasible pre-launch test option. This paper compares the acoustic measurements of two different subscale tests: the 2% Ares Liftoff Acoustic Test conducted at Stennis Space Center and the 5% Ares I Scale Model Acoustic Test conducted at Marshall Space Flight Center.

  14. Rapid characterisation of vegetation structure to predict refugia and climate change impacts across a global biodiversity hotspot

    NARCIS (Netherlands)

    Schut, A.G.T.; Wardell-Johnson, G.W.; Yates, C.J.; Keppel, G.; Baran, I.; Franklin, S.E.; Hopper, S.D.; Niel, Van K.P.; Mucina, L.; Byrne, M.

    2014-01-01

    Identification of refugia is an increasingly important adaptation strategy in conservation planning under rapid anthropogenic climate change. Granite outcrops (GOs) provide extraordinary diversity, including a wide range of taxa, vegetation types and habitats in the Southwest Australian Floristic

  15. Acoustic sorting models for improved log segregation

    Science.gov (United States)

    Xiping Wang; Steve Verrill; Eini Lowell; Robert J. Ross; Vicki L. Herian

    2013-01-01

    In this study, we examined three individual log measures (acoustic velocity, log diameter, and log vertical position in a tree) for their ability to predict average modulus of elasticity (MOE) and grade yield of structural lumber obtained from Douglas-fir (Pseudotsuga menziesii [Mirb. Franco]) logs. We found that log acoustic velocity only had a...

  16. Acoustic Territoriality

    DEFF Research Database (Denmark)

    Kreutzfeldt, Jacob

    2011-01-01

    Under the heading of "Gang i København" a number of initiatives was presented by the Lord Mayer and the Technical and Environmental Mayer of Copenhagen in May 2006. The aim of the initiative, which roughly translates to Lively Copenhagen, was both to make Copenhagen a livelier city in terms of ci...... this article outline a few approaches to a theory of acoustic territoriality....

  17. Acoustic chaos

    Energy Technology Data Exchange (ETDEWEB)

    Lauterborn, W.; Parlitz, U. [Drittes Physikalisches Institut, Universitaet Goettingen, D-37073 Goettingen (Germany); Holzfuss, J.; Billo, A. [Institut fuer Angewandte Physik, Technische Hochschule Darmstadt, D-64289 Darmstadt (Germany); Akhatov, I. [Department of Continuous Media Mechanics, Bashkir State University, Ufa 450074 (Russia)

    1996-06-01

    Acoustic cavitation, a complex, spatio-temporal dynamical system, is investigated with respect to its chaotic properties. The sound output, the {open_quote}{open_quote}noise{close_quote}{close_quote}, is subjected to time series analysis. The spatial dynamics of the bubble filaments is captured by high speed holographic cinematography and subsequent digital picture processing from the holograms. Theoretical models are put forward for describing the pattern formation. {copyright} {ital 1996 American Institute of Physics.}

  18. Treatment of early and late reflections in a hybrid computer model for room acoustics

    DEFF Research Database (Denmark)

    Naylor, Graham

    1992-01-01

    The ODEON computer model for acoustics in large rooms is intended for use both in design (by predicting room acoustical indices quickly and easily) and in research (by forming the basis of an auralization system and allowing study of various room acoustical phenomena). These conflicting demands...... preclude the use of both ``pure'' image source and ``pure'' particle tracing methods. A hybrid model has been developed, in which rays discover potential image sources up to a specified order. Thereafter, the same ray tracing process is used in a different way to rapidly generate a dense reverberant decay....... In this paper the computational model is described. Particular attention is paid to alternative methods of implementing the reverberant tail, and to the problems that arise when joining early and late parts of a reflectogram generated with different algorithms. A companion paper presents the features...

  19. Depth- and range-dependent variation in the performance of aquatic telemetry systems: understanding and predicting the susceptibility of acoustic tag–receiver pairs to close proximity detection interference

    Directory of Open Access Journals (Sweden)

    Stephen R. Scherrer

    2018-01-01

    Full Text Available Background Passive acoustic telemetry using coded transmitter tags and stationary receivers is a popular method for tracking movements of aquatic animals. Understanding the performance of these systems is important in array design and in analysis. Close proximity detection interference (CPDI is a condition where receivers fail to reliably detect tag transmissions. CPDI generally occurs when the tag and receiver are near one another in acoustically reverberant settings. Here we confirm transmission multipaths reflected off the environment arriving at a receiver with sufficient delay relative to the direct signal cause CPDI. We propose a ray-propagation based model to estimate the arrival of energy via multipaths to predict CPDI occurrence, and we show how deeper deployments are particularly susceptible. Methods A series of experiments were designed to develop and validate our model. Deep (300 m and shallow (25 m ranging experiments were conducted using Vemco V13 acoustic tags and VR2-W receivers. Probabilistic modeling of hourly detections was used to estimate the average distance a tag could be detected. A mechanistic model for predicting the arrival time of multipaths was developed using parameters from these experiments to calculate the direct and multipath path lengths. This model was retroactively applied to the previous ranging experiments to validate CPDI observations. Two additional experiments were designed to validate predictions of CPDI with respect to combinations of deployment depth and distance. Playback of recorded tags in a tank environment was used to confirm multipaths arriving after the receiver’s blanking interval cause CPDI effects. Results Analysis of empirical data estimated the average maximum detection radius (AMDR, the farthest distance at which 95% of tag transmissions went undetected by receivers, was between 840 and 846 m for the deep ranging experiment across all factor permutations. From these results, CPDI was

  20. Bone morphology of the femur and tibia captured by statistical shape modelling predicts rapid bone loss in acute spinal cord injury patients.

    Science.gov (United States)

    Varzi, Delaram; Coupaud, Sylvie A F; Purcell, Mariel; Allan, David B; Gregory, Jennifer S; Barr, Rebecca J

    2015-12-01

    After spinal cord injury (SCI), bone loss in the paralysed limbs progresses at variable rates. Decreases in bone mineral density (BMD) in the first year range from 1% (slow) to 40% (rapid). In chronic SCI, fragility fractures commonly occur around the knee, with significant associated morbidity. Osteoporosis treatments await full evaluation in SCI, but should be initiated early and targeted towards patients exhibiting rapid bone loss. The potential to predict rapid bone loss from a single bone scan within weeks of a SCI was investigated using statistical shape modelling (SSM) of bone morphology, hypothesis: baseline bone shape predicts bone loss at 12-months post-injury at fracture-prone sites. In this retrospective cohort study 25 SCI patients (median age, 33 years) were scanned at the distal femur and proximal tibia using peripheral Quantitative Computed Tomography at tibia mode 3, +1 SD) was associated with 9.4% additional 12-month tibial trabecular BMD loss. Baseline bone shape determined from a single bone scan is a valid imaging biomarker for the prediction of 12-month bone loss in SCI patients. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Acoustic Neuroma Association

    Science.gov (United States)

    ... EVENTS DONATE NEWS Home Learn Back Learn about acoustic neuroma AN Facts What is acoustic neuroma? Diagnosing ... Brain Freeze ? READ MORE Read More What is acoustic neuroma? Identifying an AN Learn More Get Info ...

  2. Analytical prediction of the interior noise for cylindrical models of aircraft fuselages for prescribed exterior noise fields. Phase 2: Models for sidewall trim, stiffened structures and cabin acoustics with floor partition

    Science.gov (United States)

    Pope, L. D.; Wilby, E. G.

    1982-04-01

    An airplane interior noise prediction model is developed to determine the important parameters associated with sound transmission into the interiors of airplanes, and to identify apropriate noise control methods. Models for stiffened structures, and cabin acoustics with floor partition are developed. Validation studies are undertaken using three test articles: a ring stringer stiffened cylinder, an unstiffened cylinder with floor partition, and ring stringer stiffened cylinder with floor partition and sidewall trim. The noise reductions of the three test articles are computed using the heoretical models and compared to measured values. A statistical analysis of the comparison data indicates that there is no bias in the predictions although a substantial random error exists so that a discrepancy of more than five or six dB can be expected for about one out of three predictions.

  3. Predicting meaningful outcomes to medication and self-help treatments for binge-eating disorder in primary care: The significance of early rapid response.

    Science.gov (United States)

    Grilo, Carlos M; White, Marney A; Masheb, Robin M; Gueorguieva, Ralitza

    2015-04-01

    We examined rapid response among obese patients with binge-eating disorder (BED) in a randomized clinical trial testing antiobesity medication and self-help cognitive-behavioral therapy (shCBT), alone and in combination, in primary-care settings. One hundred four obese patients with BED were randomly assigned to 1 of 4 treatments: sibutramine, placebo, shCBT + sibutramine, or shCBT + placebo. Treatments were delivered by generalist primary-care physicians and the medications were given double-blind. Independent assessments were performed by trained and monitored doctoral research clinicians monthly throughout treatment, posttreatment (4 months), and at 6- and 12-month follow-ups (i.e., 16 months after randomization). Rapid response, defined as ≥65% reduction in binge eating by the fourth treatment week, was used to predict outcomes. Rapid response characterized 47% of patients, was unrelated to demographic and baseline clinical characteristics, and was significantly associated, prospectively, with remission from binge eating at posttreatment (51% vs. 9% for nonrapid responders), 6-month (53% vs. 23.6%), and 12-month (46.9% vs. 23.6%) follow-ups. Mixed-effects model analyses revealed that rapid response was significantly associated with greater decreases in binge-eating or eating-disorder psychopathology, depression, and percent weight loss. Our findings, based on a diverse obese patient group receiving medication and shCBT for BED in primary-care settings, indicate that patients who have a rapid response achieve good clinical outcomes through 12-month follow-ups after ending treatment. Rapid response represents a strong prognostic indicator of clinically meaningful outcomes, even in low-intensity medication and self-help interventions. Rapid response has important clinical implications for stepped-care treatment models for BED. clinicaltrials.gov: NCT00537810 (PsycINFO Database Record (c) 2015 APA, all rights reserved).

  4. A High-precision Correction Method of Ultra-rapid Ephemeris Clock Bias Prediction for GPS Block IIR-M Satellites

    Directory of Open Access Journals (Sweden)

    CAI Chenglin

    2016-07-01

    Full Text Available A high-precision correction algorithm based on the block IIR-M satellites is proposed to improve the precision of IGS ultra-rapid predicted (IGU-P products. In order to ensure that the real-time precise point positioning (RTPPP with high positioning accuracy could come true, it is attempted to get the difference between the first prediction data and the last epoch of IGS ultra-rapid observed (IGU-O, and then to compute the value and determine the direction of accuracy revised value based on influence of the degree of residual value to difference sequence of IGU-O. The numerical examples with the data set of 19 IGU files showed that the prediction accuracy of proposed method was superior to three basic models and IGU-P within 6 hours, the rate of improved accuracy range from 3.48% to 6.13%, and average prediction accuracy of corresponding models were, in order,0.599 ns,0.570 ns and 0.531 ns.

  5. Rapid activity prediction of HIV-1 integrase inhibitors: harnessing docking energetic components for empirical scoring by chemometric and artificial neural network approaches.

    Science.gov (United States)

    Thangsunan, Patcharapong; Kittiwachana, Sila; Meepowpan, Puttinan; Kungwan, Nawee; Prangkio, Panchika; Hannongbua, Supa; Suree, Nuttee

    2016-06-01

    Improving performance of scoring functions for drug docking simulations is a challenging task in the modern discovery pipeline. Among various ways to enhance the efficiency of scoring function, tuning of energetic component approach is an attractive option that provides better predictions. Herein we present the first development of rapid and simple tuning models for predicting and scoring inhibitory activity of investigated ligands docked into catalytic core domain structures of HIV-1 integrase (IN) enzyme. We developed the models using all energetic terms obtained from flexible ligand-rigid receptor dockings by AutoDock4, followed by a data analysis using either partial least squares (PLS) or self-organizing maps (SOMs). The models were established using 66 and 64 ligands of mercaptobenzenesulfonamides for the PLS-based and the SOMs-based inhibitory activity predictions, respectively. The models were then evaluated for their predictability quality using closely related test compounds, as well as five different unrelated inhibitor test sets. Weighting constants for each energy term were also optimized, thus customizing the scoring function for this specific target protein. Root-mean-square error (RMSE) values between the predicted and the experimental inhibitory activities were determined to be <1 (i.e. within a magnitude of a single log scale of actual IC50 values). Hence, we propose that, as a pre-functional assay screening step, AutoDock4 docking in combination with these subsequent rapid weighted energy tuning methods via PLS and SOMs analyses is a viable approach to predict the potential inhibitory activity and to discriminate among small drug-like molecules to target a specific protein of interest.

  6. The Predictability of Large-Scale, Short-Period Ocean Variability in the Philippine Sea and the Influence of Such Variability on Long-Range Acoustic Propagation

    Science.gov (United States)

    2013-09-30

    Norwegian ACOBAR ( Fram Strait) collaborations in the present case. These experiments have been conducted primarily by Peter Worcester and his group at the...existing publication that shows that any such effects are of practical consequence. Tomography in Fram Strait Part of this project was redirected toward...research on acoustics and tomography within Fram Strait, with permission from the program manager. This section describes the results of research

  7. Visual Event-Related Potentials to Novel Objects Predict Rapid Word Learning Ability in 20-Month-Olds.

    Science.gov (United States)

    Borgström, Kristina; Torkildsen, Janne von Koss; Lindgren, Magnus

    In an event-related potentials (ERP) study, twenty-month-old children (n = 37) were presented with pseudowords to map to novel object referents in five presentations. Quicker attenuation of the visual Negative central component (Nc) to novel objects predicted a larger difference in N400 amplitude between congruous and incongruous presentations of pseudowords at test. Furthermore, better initial recognition of familiar objects (Nc difference between familiar and novel objects) predicted the strength of the N400 incongruity effect to the verbal labels of these real objects. This study presents novel evidence for a link between efficient visual processing of objects and word learning ability.

  8. Nondestructive quality evaluation of agro-products using acoustic vibration methods-A review.

    Science.gov (United States)

    Zhang, Wen; Lv, Zhenzhen; Xiong, Shuangli

    2017-06-14

    Quality evaluation of agro-products is quite important because it is the basis for growers, distributers, and consumers. Various novel and emerging nondestructive methods were proposed for quality evaluation of agro-products. The acoustic vibration method is one of the major nondestructive methods for agro-products in pre- and postharvest research and industrial practice. Acoustic vibration characteristics of agro-products can be used for texture evaluation, prediction of optimum eating and harvest ripeness, ripeness classification and defect detection. Generally, there are three parts in the process of acoustic vibration method, including the excitation module, signal acquisition module, and signal-processing module. The impact method and forced method are two excitation methods in the excitation module, and there are contact and noncontact sensors for vibration measurement in the signal acquisition module. Noncontact measurement can meet the requirement of rapid and nondestructive measurement, especially for the on-line detection. However, increasing demand for accurate and cost-effective measurement remains a challenge in the agro-products industry. Comparison of acoustic vibration methods and traditional destructive methods was also discussed, which helps to give a more comprehensive assessment for the acoustic vibration method.

  9. Rapid slowing of the atrial fibrillatory rate after administration of AZD7009 predicts conversion of atrial fibrillation

    DEFF Research Database (Denmark)

    Aunes, Maria; Egstrup, Kenneth; Frison, Lars

    2014-01-01

    BACKGROUND: Effects on the atrial fibrillatory rate (AFR) were studied during infusion with the combined potassium and sodium channel blocker AZD7009. METHODS AND RESULTS: Patients with persistent atrial fibrillation (AF) were randomized to AZD7009 or placebo. Thirty-five patients converted to si...... fpm (p=0.02), and at 10 min, -133 vs. -111 fpm (p=0.048). The AFR-SD and the exponential decay decreased. A small left atrial area was the only baseline predictor of conversion to SR. CONCLUSIONS: AZD7009 produced a significantly more rapid decrease of the AFR in converters than in non...

  10. Quantification of whey proteins by reversed phase-HPLC and effectiveness of mid-infrared spectroscopy for their rapid prediction in sweet whey.

    Science.gov (United States)

    Sturaro, Alba; De Marchi, Massimo; Masi, Antonio; Cassandro, Martino

    2016-01-01

    In the dairy industry, membrane filtration is used to reduce the amount of whey waste and, simultaneously, to recover whey proteins (WP). The composition of WP can strongly affect the filtration treatment of whey, and rapid determination of WP fractions would be of interest for dairy producers to monitor WP recovery. This study aimed to develop mid-infrared spectroscopy (MIRS) prediction models for the rapid quantification of protein in sweet whey, using a validated rapid reversed phase (RP)-HPLC as a reference method. Quantified WP included α-lactalbumin (α-LA), β-lactoglobulin (β-LG) A and B, bovine serum albumin, caseinomacropeptides, and proteose peptone. Validation of RP-HPLC was performed by calculating the relative standard deviation (RSD) in repeatability and reproducibility tests for WP retention time and peak areas. Samples of liquid whey (n=187) were analyzed by RP-HPLC and scanned through MIRS to collect spectral information (900 to 4,000 cm(-1)); statistical analysis was carried out through partial least squares regression and random cross-validation procedure. Retention times in RP-HPLC method were stable (RSD between 0.03 and 0.80%), whereas the RSD of peak area (from 0.25 to 8.48%) was affected by WP relative abundance. Higher coefficients of determination in validation for MIRS model were obtained for protein fractions present in whey in large amounts, such as β-LG (0.58), total identified WP (0.58), and α-LA (0.56). Results of this study suggest that MIRS is an easy method for rapid quantification of detail protein in sweet whey, even if better resolution was achieved with the method based on RP-HPLC. The prediction of WP in sweet whey by MIRS might be used for screening and for classifying sweet whey according to its total and individual WP contents. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  11. The acoustic force density acting on inhomogeneous fluids in acoustic fields

    CERN Document Server

    Karlsen, Jonas T; Bruus, Henrik

    2016-01-01

    We present a theory for the acoustic force density acting on inhomogeneous fluids in acoustic fields on time scales that are slow compared to the acoustic oscillation period. The acoustic force density depends on gradients in the density and compressibility of the fluid. For microfluidic systems, the theory predicts a relocation of the inhomogeneities into stable field-dependent configurations, which are qualitatively different from the horizontally layered configurations due to gravity. Experimental validation is obtained by confocal imaging of aqueous solutions in a glass-silicon microchip.

  12. Acoustic transducer

    Science.gov (United States)

    Drumheller, Douglas S.

    2000-01-01

    An active acoustic transducer tool for use down-hole applications. The tool includes a single cylindrical mandrel including a shoulder defining the boundary of a narrowed portion over which is placed a sandwich-style piezoelectric tranducer assembly. The piezoelectric transducer assembly is prestressed by being placed in a thermal interference fit between the shoulder of the mandrel and the base of an anvil which is likewise positioned over the narrower portion of the mandrel. In the preferred embodiment, assembly of the tool is accomplished using a hydraulic jack to stretch the mandrel prior to emplacement of the cylindrical sandwich-style piezoelectric transducer assembly and anvil. After those elements are positioned and secured, the stretched mandrel is allowed to return substantially to its original (pre-stretch) dimensions with the result that the piezoelectric transducer elements are compressed between the anvil and the shoulder of the mandrel.

  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 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.

  15. Highly Localized Acoustic Streaming and Size-Selective Submicrometer Particle Concentration Using High Frequency Microscale Focused Acoustic Fields.

    Science.gov (United States)

    Collins, David J; Ma, Zhichao; Ai, Ye

    2016-05-17

    Concentration and separation of particles and biological specimens are fundamental functions of micro/nanofluidic systems. Acoustic streaming is an effective and biocompatible way to create rapid microscale fluid motion and induce particle capture, though the >100 MHz frequencies required to directly generate acoustic body forces on the microscale have traditionally been difficult to generate and localize in a way that is amenable to efficient generation of streaming. Moreover, acoustic, hydrodynamic, and electrical forces as typically applied have difficulty manipulating specimens in the submicrometer regime. In this work, we introduce highly focused traveling surface acoustic waves (SAW) at high frequencies between 193 and 636 MHz for efficient and highly localized production of acoustic streaming vortices on microfluidic length scales. Concentration occurs via a novel mechanism, whereby the combined acoustic radiation and streaming field results in size-selective aggregation in fluid streamlines in the vicinity of a high-amplitude acoustic beam, as opposed to previous acoustic radiation induced particle concentration where objects typically migrate toward minimum pressure locations. Though the acoustic streaming is induced by a traveling wave, we are able to manipulate particles an order of magnitude smaller than possible using the traveling wave force alone. We experimentally and theoretically examine the range of particle sizes that can be captured in fluid streamlines using this technique, with rapid particle concentration demonstrated down to 300 nm diameters. We also demonstrate that locations of trapping and concentration are size-dependent, which is attributed to the combined effects of the acoustic streaming and acoustic forces.

  16. Acoustic multivariate condition monitoring - AMCM

    Energy Technology Data Exchange (ETDEWEB)

    Rosenhave, P.E. [Vestfold College, Maritime Dept., Toensberg (Norway)

    1997-12-31

    In Norway, Vestfold College, Maritime Department presents new opportunities for non-invasive, on- or off-line acoustic monitoring of rotating machinery such as off-shore pumps and diesel engines. New developments within acoustic sensor technology coupled with chemometric data analysis of complex signals now allow condition monitoring of hitherto unavailable flexibility and diagnostic specificity. Chemometrics paired with existing knowledge yields a new and powerful tool for condition monitoring. By the use of multivariate techniques and acoustics it is possible to quantify wear and tear as well as predict the performance of working components in complex machinery. This presentation describes the AMCM method and one result of a feasibility study conducted onboard the LPG/C `Norgas Mariner` owned by Norwegian Gas Carriers as (NGC), Oslo. (orig.) 6 refs.

  17. Acoustic shock injury (ASI).

    Science.gov (United States)

    Westcott, Myriam

    2006-12-01

    The potential severity and persistence of ASI symptoms has significant clinical and medico-legal implications. With the rapid growth of call centres around the world, professionals providing tinnitus and hyperacusis therapy are increasingly likely to encounter some or all of the cluster of ASI symptoms in their clients. Acoustic shock injury (ASI), occurring as a result of exposure to a sudden unexpected loud sound, has been observed to cause a specific and consistent pattern of neurophysiological and psychological symptoms. These include aural pain, tinnitus, hyperacusis/phonophobia, vertigo and other unusual symptoms such as numbness or burning sensations around the ear. A range of emotional reactions including trauma, anxiety and depression can develop. Call centre staff using a telephone headset or handset are vulnerable to ASI because of the increased likelihood of exposure, close to their ear(s), of sudden unexpected loud sounds randomly transmitted via the telephone line. This paper presents an overview of a study of 103 people exposed to 123 acoustic incidents, and of the proposed neurophysiological mechanism of ASI, in particular tonic tensor tympani syndrome (TTTS). An understanding of TTTS has the potential to provide insight into the neurophysiological and psychological development of tinnitus and hyperacusis and the association with high levels of emotional trauma and anxiety. ASI rehabilitation is discussed.

  18. Acoustic Microfluidics for Bioanalytical Application

    Science.gov (United States)

    Lopez, Gabriel

    2013-03-01

    This talk will present new methods the use of ultrasonic standing waves in microfluidic systems to manipulate microparticles for the purpose of bioassays and bioseparations. We have recently developed multi-node acoustic focusing flow cells that can position particles into many parallel flow streams and have demonstrated the potential of such flow cells in the development of high throughput, parallel flow cytometers. These experiments show the potential for the creation of high throughput flow cytometers in applications requiring high flow rates and rapid detection of rare cells. This talk will also present the development of elastomeric capture microparticles and their use in acoustophoretic separations. We have developed simple methods to form elastomeric particles that are surface functionalized with biomolecular recognition reagents. These compressible particles exhibit negative acoustic contrast in ultrasound when suspended in aqueous media, blood serum or diluted blood. These particles can be continuously separated from cells by flowing them through a microfluidic device that uses an ultrasonic standing wave to align the blood cells, which exhibit positive acoustic contrast, at a node in the acoustic pressure distribution while aligning the negative acoustic contrast elastomeric particles at the antinodes. Laminar flow of the separated particles to downstream collection ports allows for collection of the separated negative contrast particles and cells. Separated elastomeric particles were analyzed via flow cytometry to demonstrate nanomolar detection for prostate specific antigen in aqueous buffer and picomolar detection for IgG in plasma and diluted blood samples. This approach has potential applications in the development of rapid assays that detect the presence of low concentrations of biomarkers (including biomolecules and cells) in a number of biological sample types. We acknowledge support through the NSF Research Triangle MRSEC.

  19. Holographic acoustic elements for manipulation of levitated objects

    Science.gov (United States)

    Marzo, Asier; Seah, Sue Ann; Drinkwater, Bruce W.; Sahoo, Deepak Ranjan; Long, Benjamin; Subramanian, Sriram

    2015-10-01

    Sound can levitate objects of different sizes and materials through air, water and tissue. This allows us to manipulate cells, liquids, compounds or living things without touching or contaminating them. However, acoustic levitation has required the targets to be enclosed with acoustic elements or had limited manoeuvrability. Here we optimize the phases used to drive an ultrasonic phased array and show that acoustic levitation can be employed to translate, rotate and manipulate particles using even a single-sided emitter. Furthermore, we introduce the holographic acoustic elements framework that permits the rapid generation of traps and provides a bridge between optical and acoustical trapping. Acoustic structures shaped as tweezers, twisters or bottles emerge as the optimum mechanisms for tractor beams or containerless transportation. Single-beam levitation could manipulate particles inside our body for applications in targeted drug delivery or acoustically controlled micro-machines that do not interfere with magnetic resonance imaging.

  20. North Pacific Acoustic Laboratory: Analysis of Shadow Zone Arrivals and Acoustic Propagation in Numerical Ocean Models

    National Research Council Canada - National Science Library

    Dushaw, Brian

    2009-01-01

    ... depth of the receiver lies well below the depths of the predicted cusps. Several models for the temperature and salinity in the North Pacific Ocean were obtained and processed to enable simulations of acoustic propagation for comparison to the observations...

  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. Using EarthScope magnetotelluric data to improve the resilience of the US power grid: rapid predictions of geomagnetically induced currents

    Science.gov (United States)

    Schultz, A.; Bonner, L. R., IV

    2016-12-01

    Existing methods to predict Geomagnetically Induced Currents (GICs) in power grids, such as the North American Electric Reliability Corporation standard adopted by the power industry, require explicit knowledge of the electrical resistivity structure of the crust and mantle to solve for ground level electric fields along transmission lines. The current standard is to apply regional 1-D resistivity models to this problem, which facilitates rapid solution of the governing equations. The systematic mapping of continental resistivity structure from projects such as EarthScope reveals several orders of magnitude of lateral variations in resistivity on local, regional and continental scales, resulting in electric field intensifications relative to existing 1-D solutions that can impact GICs to first order. The computational burden on the ground resistivity/GIC problem of coupled 3-D solutions inhibits the prediction of GICs in a timeframe useful to protecting power grids. In this work we reduce the problem to applying a set of filters, recognizing that the magnetotelluric impedance tensors implicitly contain all known information about the resistivity structure beneath a given site, and thus provides the required relationship between electric and magnetic fields at each site. We project real-time magnetic field data from distant magnetic observatories through a robustly calculated multivariate transfer function to locations where magnetotelluric impedance tensors had previously been obtained. This provides a real-time prediction of the magnetic field at each of those points. We then project the predicted magnetic fields through the impedance tensors to obtain predictions of electric fields induced at ground level. Thus, electric field predictions can be generated in real-time for an entire array from real-time observatory data, then interpolated onto points representing a power transmission line contained within the array to produce a combined electric field prediction

  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 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.

  6. A rapid and accurate approach for prediction of interactomes from co-elution data (PrInCE).

    Science.gov (United States)

    Stacey, R Greg; Skinnider, Michael A; Scott, Nichollas E; Foster, Leonard J

    2017-10-23

    An organism's protein interactome, or complete network of protein-protein interactions, defines the protein complexes that drive cellular processes. Techniques for studying protein complexes have traditionally applied targeted strategies such as yeast two-hybrid or affinity purification-mass spectrometry to assess protein interactions. However, given the vast number of protein complexes, more scalable methods are necessary to accelerate interaction discovery and to construct whole interactomes. We recently developed a complementary technique based on the use of protein correlation profiling (PCP) and stable isotope labeling in amino acids in cell culture (SILAC) to assess chromatographic co-elution as evidence of interacting proteins. Importantly, PCP-SILAC is also capable of measuring protein interactions simultaneously under multiple biological conditions, allowing the detection of treatment-specific changes to an interactome. Given the uniqueness and high dimensionality of co-elution data, new tools are needed to compare protein elution profiles, control false discovery rates, and construct an accurate interactome. Here we describe a freely available bioinformatics pipeline, PrInCE, for the analysis of co-elution data. PrInCE is a modular, open-source library that is computationally inexpensive, able to use label and label-free data, and capable of detecting tens of thousands of protein-protein interactions. Using a machine learning approach, PrInCE offers greatly reduced run time, more predicted interactions at the same stringency, prediction of protein complexes, and greater ease of use over previous bioinformatics tools for co-elution data. PrInCE is implemented in Matlab (version R2017a). Source code and standalone executable programs for Windows and Mac OSX are available at https://github.com/fosterlab/PrInCE , where usage instructions can be found. An example dataset and output are also provided for testing purposes. PrInCE is the first fast and easy

  7. PT-Symmetric Acoustics

    Directory of Open Access Journals (Sweden)

    Xuefeng Zhu

    2014-09-01

    Full Text Available We introduce here the concept of acoustic parity-time (PT symmetry and demonstrate the extraordinary scattering characteristics of the acoustic PT medium. On the basis of exact calculations, we show how an acoustic PT-symmetric medium can become unidirectionally transparent at given frequencies. Combining such a PT-symmetric medium with transformation acoustics, we design two-dimensional symmetric acoustic cloaks that are unidirectionally invisible in a prescribed direction. Our results open new possibilities for designing functional acoustic devices with directional responses.

  8. The fumarate sensor DcuS: progress in rapid protein fold elucidation by combining protein structure prediction methods with NMR spectroscopy

    Science.gov (United States)

    Meiler, Jens; Baker, David

    2005-04-01

    We illustrate how moderate resolution protein structures can be rapidly obtained by interlinking computational prediction methodologies with un- or partially assigned NMR data. To facilitate the application of our recently described method of ranking and subsequent refining alternative structural models using unassigned NMR data [Proc. Natl. Acad. Sci. USA 100 (2003) 15404] for such "structural genomics"-type experiments it is combined with protein models from several prediction techniques, enhanced to utilize partial assignments, and applied on a protein with an unknown structure and fold. From the original NMR spectra obtained for the 140 residue fumarate sensor DcuS, 1100 1H, 13C, and 15N chemical shift signals, 3000 1H- 1H NOESY cross peak intensities, and 209 backbone residual dipolar couplings were extracted and used to rank models produced by de novo structure prediction and comparative modeling methods. The ranking proceeds in two steps: first, an optimal assignment of the NMR peaks to atoms is found for each model independently, and second, the models are ranked based on the consistency between the NMR data and the model assuming these optimal assignments. The low-resolution model selected using this ranking procedure had the correct overall fold and a global backbone RMSD of 6.0Å, and was subsequently refined to 3.7 Å RMSD. With the incorporation of a small number of NOE and residual dipolar coupling constraints available very early in the traditional spectral assignment process, a model with an RMSD of 2.8 Å could rapidly be built. The ability to generate moderate resolution models within days of NMR data collection should facilitate large scale NMR structure determination efforts.

  9. Acoustic Power Transmission Through a Ducted Fan

    Science.gov (United States)

    Envia, Ed

    2016-01-01

    For high-speed ducted fans, when the rotor flowfield is shock-free, the main contribution to the inlet radiated acoustic power comes from the portion of the rotor stator interaction sound field that is transmitted upstream through the rotor. As such, inclusion of the acoustic transmission is an essential ingredient in the prediction of the fan inlet noise when the fan tip relative speed is subsonic. This paper describes a linearized Euler based approach to computing the acoustic transmission of fan tones through the rotor. The approach is embodied in a code called LINFLUX was applied to a candidate subsonic fan called the Advanced Ducted Propulsor (ADP). The results from this study suggest that it is possible to make such prediction with sufficient fidelity to provide an indication of the acoustic transmission trends with the fan tip speed.

  10. Acoustic source for generating an acoustic beam

    Science.gov (United States)

    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.

  11. Rapid method to predict the storage stability of middle distillates; Schnelltest zur Vorhersage der Lagerstabilitaet von Mitteldestillaten

    Energy Technology Data Exchange (ETDEWEB)

    Depta, H.; Wehn, R. [RWE - Gesellschaft fuer Forschung und Entwicklung mbH, Wesseling (Germany); Kohlmeyer, U. [Deutsche Shell AG, Hamburg (Germany)

    1998-12-01

    In the literature, various quick tests to predict the ageing stability of middle distillates are described. 59 gasoil components and finished products were tested, using methods recommended by a detailed literature study DGMK-Report 484, namely: - the colorimetric/spectrophotometric method according to R.K. Solly and S.J. Marshman, - the quantification of Soluble Macromolecular Oxidatively Reactive Species (SMORS) according to M.A. Wechter and D.R. Hardy, - the determination of phenalene and phenalenone as well as non-basic nitrogenous aromatics. ASTM D 4625-92 was used as a reference test (storage at 43 C over a period of 12 weeks, with air contact). The results obtained showed that none of the methods mentioned above are suitable as a reliable quick test, because the regression analysis shows no acceptable correlation between the data obtained and the insolubles derived from the reference test. The hypothesis of Pedley et al., referring to the ageing mechanism of middle distillates, could not be confirmed. The spectrophotometric method gives the best result, considering the total nitrogen content. The accuracy of the prediction of ASTM-Test results is about 75%. The additionally carried out `Rancimat-Test` does not correlate at all with the insolubles based on ASTM D 4625-92. The insolubles as determined according to ASTM D 4625 neither do correlate with the amount of sediments which are formed after one year`s storage under genuine conditions. On the other hand, the supplementarily conducted `Shell Window Test` allows a prediction of the longterm storage behaviour with a likelihood of 78% which is expected to improve after a revision of the method with regard to reproducible test conditions. (orig.) [Deutsch] In der Literatur werden verschiedene Schnelltests zur Vorhersage der Alterungsstabilitaet von Mitteldestillaten beschrieben. An 59 Gasoel-Komponenten und -Fertigprodukten wurden die in der Literaturrecherche DGMK-Bericht 484 empfohlenen Methoden ueberprueft

  12. Unidirectional propagation of designer surface acoustic waves

    CERN Document Server

    Lu, Jiuyang; Ke, Manzhu; Liu, Zhengyou

    2014-01-01

    We propose an efficient design route to generate unidirectional propagation of the designer surface acoustic waves. The whole system consists of a periodically corrugated rigid plate combining with a pair of asymmetric narrow slits. The directionality of the structure-induced surface waves stems from the destructive interference between the evanescent waves emitted from the double slits. The theoretical prediction is validated well by simulations and experiments. Promising applications can be anticipated, such as in designing compact acoustic circuits.

  13. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... more... LOGIN CALENDAR DONATE NEWS Home Learn Back Learn about acoustic neuroma AN Facts What is acoustic ... Stories Keywords Shop ANA Discussion Forum About Back Learn more about ANA About ANA Mission, Vision & Values ...

  14. Tethys Acoustic Metadata Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Tethys database houses the metadata associated with the acoustic data collection efforts by the Passive Acoustic Group. These metadata include dates, locations...

  15. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... is acoustic neuroma? Diagnosing Symptoms Side Effects Keywords Questions to ask Choosing a healthcare provider Request a ... What is acoustic neuroma Diagnosing Symptoms Side effects Question To Ask Treatment Options Back Overview Observation Radiation ...

  16. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... Facts What is acoustic neuroma? Diagnosing Symptoms Side Effects Keywords Questions to ask Choosing a healthcare provider ... Surgery What is acoustic neuroma Diagnosing Symptoms Side effects Question To Ask Treatment Options Back Overview Observation ...

  17. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... resource Click to learn more... LOGIN CALENDAR DONATE NEWS Home Learn Back Learn about acoustic neuroma AN ... sponsors Become a Sponsor Acoustic Neuroma Association Latest News Join / Renew Login Contact Us Become a Sponsor ...

  18. 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 underwater...

  19. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... more Click to learn more... LOGIN CALENDAR DONATE NEWS Home Learn Back Learn about acoustic neuroma AN ... a Sponsor Patient Events Acoustic Neuroma Association Latest News Join / Renew Login Contact Us Become a Sponsor ...

  20. Prediction of transverse shrinkages of young-growth Sitka spruce (Picea sitchensis) and western hemlock (Tsuga heterophylla) with ultrasonic measurements

    Science.gov (United States)

    Turker Dundar; Xiping Wang; Robert J. Ross

    2013-01-01

    The objective of this study was to examine the potential of acoustic measurement as a rapid and nondestructive method to predict the dimensional stability of young-growth Sitka spruce and western hemlock. Ultrasonic velocity, peak energy, specific gravity, and radial and tangential shrinkages were measured on twenty-four 25- x

  1. 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).

  2. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available Acoustic Neuroma Association 600 Peachtree Parkway Suite 108 Cumming, GA 30041 770-205-8211 info@ANAUSA.org The world's #1 acoustic ... Shop ANA Leadership & Staff Annual Reports Acoustic Neuroma Association 600 Peachtree Parkway Suite 108 Cumming, GA 30041 ...

  3. Outcome analysis of aromatase inhibitor therapy to increase adult height in males with predicted short adult stature and/or rapid pubertal progress: a retrospective chart review.

    Science.gov (United States)

    Shams, Kim; Cameo, Tamara; Fennoy, Ilene; Hassoun, Abeer A; Lerner, Shulamit E; Aranoff, Gaya S; Sopher, Aviva B; Yang, Christine; McMahon, Donald J; Oberfield, Sharon E

    2014-07-01

    Aromatase inhibitors (AIs) have been used off-label to increase adult height in short adolescent males. Studies have shown that AIs increase the predicted adult height (PAH) while delaying bone age (BA) maturation. We sought to determine whether AI therapy increases PAH in boys with short stature or rapid pubertal progression, and to evaluate any untoward effects. The charts of 27 boys with BA ≥ 13 and short stature [height ≥ 2 standard deviation (SD) below the mean or ≥ 2 SD below mid-parental target height (MPTH)] or rapid pubertal progress, treated with anastrozole were reviewed. Outcome measures included anthropomorphic, hormonal, and metabolic data. The AI therapy averaged 21 months (range 14-30 months) for all, with Rx group 1 receiving height SDS, or BA/chronological age (CA). In Rx group 2, there was a small, nonsignificant increase in PAH, no change in height SDS, and a small decrease in BA/CA. Post-therapy PAH was different from MPTH in all and in both Rx groups 1 and 2, pheight, averaging 6.73 ± 1.40 cm less than MPTH and 1.91 ± 0.86 cm less than the pre-therapy PAH. Post-therapy, the initially decreased estradiol did not persist but mildly increased testosterone and decreased high-density lipoprotein were noted, as was an increase in hematocrit, and decrease in growth velocity. We suggest that although bone age progression may be slightly delayed with longer duration of therapy, an overall short-term AI therapy does not lead to a final height that is greater than the predicted pre-therapy height.

  4. Rapid Recovery of CD3+CD8+ T Cells on Day 90 Predicts Superior Survival after Unmanipulated Haploidentical Blood and Marrow Transplantation.

    Science.gov (United States)

    Tian, Deng-Mei; Wang, Yu; Zhang, Xiao-Hui; Liu, Kai-Yan; Huang, Xiao-Jun; Chang, Ying-Jun

    2016-01-01

    Rapid immune reconstitution after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is significantly associated with lower infection, relapse and possibly secondary malignancy rates. The aim of this study was to investigate the role of peripheral lymphocyte subsets, especially CD3+CD8+ cytotoxic T cell recovery, in predicting transplant outcomes, including the overall survival (OS) and non-relapse mortality (NRM) rates after unmanipulated haploidentical blood and marrow transplantation (HBMT). Peripheral blood samples were obtained from 214 HBMT recipients with hematological malignancies. The peripheral lymphocyte subsets (CD3+ T cells, CD3+CD4+ helper T cells, CD3+CD8+ cytotoxic T cells, and CD19+ B cells) were analyzed by flow cytometry at days 30, 60, 90, 180, 270 and 360 after HBMT. The CD3+CD8+ cytotoxic T cell recovery at day 90 (CD3+CD8+-90) was correlated with bacterial infection (P = 0.001), NRM (P = 0.001), leukemia-free survival (LFS, P = 0.005), and OS (P = 0.001) at a cutoff value of 375 cells/μL CD3+CD8+ T cells. The incidence of bacterial infection in patients with the CD3+CD8+-90 at ≥375 cells/μL was significantly lower than that of cases with the CD3+CD8+-90 at CD3+CD8+ T cells at day 90 after HBMT was strongly associated with a lower incidence of NRM (HR = 0.30; 95% CI: 0.15-0.60; P = 0.000) and superior LFS (HR = 0.51; 95% CI: 0.32-0.82; P = 0.005) and OS (HR = 0.38; 95% CI: 0.23-0.63; P = 0.000). The results suggest that the rapid recovery of CD3+CD8+ cytotoxic T cells at day 90 following HBMT could predict superior transplant outcomes.

  5. Near-Infrared Spectroscopy, a Rapid Method for Predicting the Age of Male and Female Wild-Type and Wolbachia Infected Aedes aegypti.

    Directory of Open Access Journals (Sweden)

    Maggy T Sikulu-Lord

    2016-10-01

    Full Text Available Estimating the age distribution of mosquito populations is crucial for assessing their capacity to transmit disease and for evaluating the efficacy of available vector control programs. This study reports on the capacity of the near-infrared spectroscopy (NIRS technique to rapidly predict the ages of the principal dengue and Zika vector, Aedes aegypti. The age of wild-type males and females, and males and females infected with wMel and wMelPop strains of Wolbachia pipientis were characterized using this method. Calibrations were developed using spectra collected from their heads and thoraces using partial least squares (PLS regression. A highly significant correlation was found between the true and predicted ages of mosquitoes. The coefficients of determination for wild-type females and males across all age groups were R2 = 0.84 and 0.78, respectively. The coefficients of determination for the age of wMel and wMelPop infected females were 0.71 and 0.80, respectively (P< 0.001 in both instances. The age of wild-type female Ae. aegypti could be identified as < or ≥ 8 days old with an accuracy of 91% (N = 501, whereas female Ae. aegypti infected with wMel and wMelPop were differentiated into the two age groups with an accuracy of 83% (N = 284 and 78% (N = 229, respectively. Our results also indicate NIRS can distinguish between young and old male wild-type, wMel and wMelPop infected Ae. aegypti with accuracies of 87% (N = 253, 83% (N = 277 and 78% (N = 234, respectively. We have demonstrated the potential of NIRS as a predictor of the age of female and male wild-type and Wolbachia infected Ae. aegypti mosquitoes under laboratory conditions. After field validation, the tool has the potential to offer a cheap and rapid alternative for surveillance of dengue and Zika vector control programs.

  6. Rapid profiling of polymeric phenolic acids in Salvia miltiorrhiza by hybrid data-dependent/targeted multistage mass spectrometry acquisition based on expected compounds prediction and fragment ion searching.

    Science.gov (United States)

    Shen, Yao; Feng, Zijin; Yang, Min; Zhou, Zhe; Han, Sumei; Hou, Jinjun; Li, Zhenwei; Wu, Wanying; Guo, De-An

    2018-01-15

    Phenolic acids are the major water-soluble components in Salvia miltiorrhiza (> 5%). According to previous studies, many of them contribute to the cardiovascular effects and antioxidant effects of S. miltiorrhiza. Polymeric phenolic acids can be considered as the tanshinol derived metabolites, e.g., dimmers, trimers and tetramers. A strategy combined with tanshinol-based expected compounds prediction, total ion chromatogram filtering, Fragment Ion Searching and parent list-based multistage mass spectrometry acquisition by Linear Trap Quadropole-orbitrap Velos Mass Spectrometry was proposed to rapid profile polymeric phenolic acids in S. miltiorrhiza. More than 480 potential polymeric phenolic acids could be screened out by this strategy. Based on the fragment information obtained by parent list-activated data dependent multistage mass spectrometry acquisition, 190 polymeric phenolic acids were characterized by comparing their mass information with literature data, and 18 of them were firstly detected from S. miltiorrhiza. Seven potential compounds were tentatively characterized as new polymeric phenolic acids from S. miltiorrhiza. This strategy facilitates identification of polymeric phenolic acids in complex matrix with both selectivity and sensitivity, which could be expanded for rapid discovery and identification of compounds from complex matrix. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  7. Rapid Recovery of CD3+CD8+ T Cells on Day 90 Predicts Superior Survival after Unmanipulated Haploidentical Blood and Marrow Transplantation.

    Directory of Open Access Journals (Sweden)

    Deng-Mei Tian

    Full Text Available Rapid immune reconstitution after allogeneic hematopoietic stem cell transplantation (allo-HSCT is significantly associated with lower infection, relapse and possibly secondary malignancy rates. The aim of this study was to investigate the role of peripheral lymphocyte subsets, especially CD3+CD8+ cytotoxic T cell recovery, in predicting transplant outcomes, including the overall survival (OS and non-relapse mortality (NRM rates after unmanipulated haploidentical blood and marrow transplantation (HBMT.Peripheral blood samples were obtained from 214 HBMT recipients with hematological malignancies. The peripheral lymphocyte subsets (CD3+ T cells, CD3+CD4+ helper T cells, CD3+CD8+ cytotoxic T cells, and CD19+ B cells were analyzed by flow cytometry at days 30, 60, 90, 180, 270 and 360 after HBMT.The CD3+CD8+ cytotoxic T cell recovery at day 90 (CD3+CD8+-90 was correlated with bacterial infection (P = 0.001, NRM (P = 0.001, leukemia-free survival (LFS, P = 0.005, and OS (P = 0.001 at a cutoff value of 375 cells/μL CD3+CD8+ T cells. The incidence of bacterial infection in patients with the CD3+CD8+-90 at ≥375 cells/μL was significantly lower than that of cases with the CD3+CD8+-90 at <375 cells/μL after HBMT (14.6% versus 41.6%, P<0.001. Multivariate analysis showed the rapid recovery of CD3+CD8+ T cells at day 90 after HBMT was strongly associated with a lower incidence of NRM (HR = 0.30; 95% CI: 0.15-0.60; P = 0.000 and superior LFS (HR = 0.51; 95% CI: 0.32-0.82; P = 0.005 and OS (HR = 0.38; 95% CI: 0.23-0.63; P = 0.000.The results suggest that the rapid recovery of CD3+CD8+ cytotoxic T cells at day 90 following HBMT could predict superior transplant outcomes.

  8. International Space Station Acoustics - A Status Report

    Science.gov (United States)

    Allen, Christopher S.

    2015-01-01

    It is important to control acoustic noise aboard the International Space Station (ISS) to provide a satisfactory environment for voice communications, crew productivity, alarm audibility, and restful sleep, and to minimize the risk for temporary and permanent hearing loss. Acoustic monitoring is an important part of the noise control process on ISS, providing critical data for trend analysis, noise exposure analysis, validation of acoustic analyses and predictions, and to provide strong evidence for ensuring crew health and safety, thus allowing Flight Certification. To this purpose, sound level meter (SLM) measurements and acoustic noise dosimetry are routinely performed. And since the primary noise sources on ISS include the environmental control and life support system (fans and airflow) and active thermal control system (pumps and water flow), acoustic monitoring will reveal changes in hardware noise emissions that may indicate system degradation or performance issues. This paper provides the current acoustic levels in the ISS modules and sleep stations and is an update to the status presented in 2011. Since this last status report, many payloads (science experiment hardware) have been added and a significant number of quiet ventilation fans have replaced noisier fans in the Russian Segment. Also, noise mitigation efforts are planned to reduce the noise levels of the T2 treadmill and levels in Node 3, in general. As a result, the acoustic levels on the ISS continue to improve.

  9. Prediction of difficult intubations using conventional indicators; Does rapid sequence intubation ease difficult intubations? A prospective randomised study in a tertiary care teaching hospital

    Directory of Open Access Journals (Sweden)

    Gangadharan Lakshmi

    2011-01-01

    Full Text Available Background : Endotracheal intubations performed in the Emergency Department. Aims : To assess whether conventional indicators of difficult airway can predict a difficult intubation in the Emergency Setting and to investigate the effect of rapid sequence intubation (RSI on ease of intubation. Settings and Design : A prospective randomized study was designed involving 60 patients requiring intubation, over a period of 4 months. Materials and Methods : Demographic profile, details of methods used, airway assessment, ease of intubation, and Cormack and Lehane score were recorded. Airway assessment score and ease of intubation criteria were devised and assessed. Statistical Analysis : Descriptive statistical analysis was carried out. Chi-square/2 × 2, 2 × 3, 3 × 3, Fisher Exact test have been used to find the significance of study parameters on categorical scale between two or more groups. Results : Patients with a Mallampatti score of three or four were found to have worse laryngoscopic views (Cormack-Lehane score, 3 or 4. Of all airway indicators assessed, an increased Mallampatti score was found to have significant correlation with increased difficulty in intubation. The use of RSI was associated with better laryngoscopic views, and easier intubations. Conclusions : An airway assessment using the Mallampatti score is invaluable as a tool to predict a difficult airway and should be performed routinely if possible. RSI aids intubation ease. If not otherwise contraindicated, it should be performed routinely for all intubations in the ED.

  10. Acoustic Tomography in the Canary Basin: Meddies and Tides

    Science.gov (United States)

    Dushaw, Brian D.; Gaillard, Fabienne; Terre, Thierry

    2017-11-01

    An acoustic propagation experiment over 308 km range conducted in the Canary Basin in 1997-1998 was used to assess the ability of ocean acoustic tomography to measure the flux of Mediterranean water and Meddies. Instruments on a mooring adjacent to the acoustic path measured the southwestward passage of a strong Meddy in temperature, salinity, and current. Over 9 months of transmissions, the acoustic arrival pattern was an initial broad stochastic pulse varying in duration by 250-500 ms, followed eight stable, identified-ray arrivals. Small-scale sound speed fluctuations from Mediterranean water parcels littered around the sound channel axis caused acoustic scattering. Internal waves contributed more modest acoustic scattering. Based on simulations, the main effect of a Meddy passing across the acoustic path is the formation of many early-arriving, near-axis rays, but these rays are thoroughly scattered by the small-scale Mediterranean-water fluctuations. A Meddy decreases the deep-turning ray travel times by 10-30 ms. The dominant acoustic signature of a Meddy is therefore the expansion of the width of the initial stochastic pulse. While this signature appears inseparable from the other effects of Mediterranean water in this region, the acoustic time series indicates the steady passage of Mediterranean water across the acoustic path. Tidal variations caused by the mode-1 internal tides were measured by the acoustic travel times. The observed internal tides were partly predicted using a recent global model for such tides derived from satellite altimetry.

  11. Theory and modeling of cylindrical thermo-acoustic transduction

    Energy Technology Data Exchange (ETDEWEB)

    Tong, Lihong, E-mail: lhtong@ecjtu.edu.cn [School of Civil Engineering and Architecture, East China Jiaotong University, Nanchang, Jiangxi (China); Lim, C.W. [Department of Architecture and Civil Engineering, City University of Hong Kong, Kowloon, Hong Kong SAR (China); Zhao, Xiushao; Geng, Daxing [School of Civil Engineering and Architecture, East China Jiaotong University, Nanchang, Jiangxi (China)

    2016-06-03

    Models both for solid and thinfilm-solid cylindrical thermo-acoustic transductions are proposed and the corresponding acoustic pressure solutions are obtained. The acoustic pressure for an individual carbon nanotube (CNT) as a function of input power is investigated analytically and it is verified by comparing with the published experimental data. Further numerical analysis on the acoustic pressure response and characteristics for varying input frequency and distance are also examined both for solid and thinfilm-solid cylindrical thermo-acoustic transductions. Through detailed theoretical and numerical studies on the acoustic pressure solution for thinfilm-solid cylindrical transduction, it is concluded that a solid with smaller thermal conductivity favors to improve the acoustic performance. In general, the proposed models are applicable to a variety of cylindrical thermo-acoustic devices performing in different gaseous media. - Highlights: • Theory and modeling both for solid and thinfilm-solid cylindrical thermo-acoustic transductions are proposed. • The modeling is verified by comparing with the published experimental data. • Acoustic response characteristics of cylindrical thermo-acoustic transductions are predicted by the proposed model.

  12. Acoustical characteristic predictions of a multi-layer system of a submerged vehicle hull mounted sonar simplified to an infinite planar model

    Directory of Open Access Journals (Sweden)

    Sung-Hee Kim

    2012-06-01

    Full Text Available Hull Mounted Sonar (HMS is a long range submerged vehicle's hull-mounted passive sonar system which detects low-frequency noise caused by machineries of enemy ships or submerged vehicles. The HMS needs a sound absorption /insulation multi-layer structure to shut out the self-noise from own machineries and to amplify signals from outside. Therefore, acoustic analysis of the multi-layer system should be performed when the HMS is designed. This paper simplified the HMS multi-layer system to be an infinite planar multi-layer model. Also, main excitations that influence the HMS were classified into mechanical, plane wave and turbulent flow excitation, and the investigations for each excitation were performed for various models. Stiffened multi-layer analysis for mechanical excitation and general multi-layer analysis for turbulent flow excitation were developed. The infinite planar multi-layer analysis was expected to be more useful for preliminary design stage of HMS system than the infinite cylindrical model because of short analysis time and easiness of parameter study.

  13. Use of "biokit HSV-2 Rapid Assay" to improve the positive predictive value of Focus HerpeSelect HSV-2 ELISA.

    Science.gov (United States)

    Morrow, Rhoda Ashley; Friedrich, David; Meier, Amalia; Corey, Lawrence

    2005-10-14

    Commercially available assays to detect antibodies to the herpes simplex virus type 2 (HSV-2)-specific glycoprotein gG-2 have markedly improved serologic diagnosis of HSV-2 infection. However, even tests with high specificity can have low positive predictive values in low prevalence populations. HSV-2 is a chronic, life-long viral infection that requires both medical attention and potential alterations in health care strategy. As such, the concern for false positive diagnoses is high confirmatory testing is routine for other viral serologies such as HIV and hepatitis C. We evaluated such a strategy for HSV-2 serology by using an easily performed commercial test, biokitHSV-2 rapid test ("Biokit"; Biokit USA, Lexington MA) as a confirmatory test for the widely used gG-2 specific serology ("Focus;" HerpeSelect HSV-2 ELISA; Focus Diagnostics, Cypress CA). We tested 782 sera by Focus HSV-2 ELISA, Biokit, and the current gold standard test, Western blot (WB). The positive predictive value of the Focus HSV-2 ELISA increased from 80.5% to 95.6% when Biokit testing was performed on sera that were initially positive by Focus HSV-2 ELISA. Confirmatory testing increased the specificity markedly among sera with Focus EIA values between 1.1 and 3.5: only 35% of low positive (index values 1.1-3.5) Focus HSV-2 ELISA results confirmed as positive by Biokit and WB compared with 92% of those with index values >3.5. Mathematical modeling of the data resulted in expected positive predictive values over 98% for populations with antibody prevalences typical of clinical practices in the US and Europe. Confirmatory Biokit testing of positive Focus HSV-2 ELISA results is fast, easy, and effective in reducing falsely positive HSV-2 antibody results. Patients, clinicians, and laboratories could benefit from the enhanced specificity of this simple HSV-2 serologic test combination.

  14. Use of "biokit HSV-2 Rapid Assay" to improve the positive predictive value of Focus HerpeSelect HSV-2 ELISA

    Directory of Open Access Journals (Sweden)

    Friedrich David

    2005-10-01

    Full Text Available Abstract Background Commercially available assays to detect antibodies to the herpes simplex virus type 2 (HSV-2-specific glycoprotein gG-2 have markedly improved serologic diagnosis of HSV-2 infection. However, even tests with high specificity can have low positive predictive values in low prevalence populations. HSV-2 is a chronic, life-long viral infection that requires both medical attention and potential alterations in health care strategy. As such, the concern for false positive diagnoses is high confirmatory testing is routine for other viral serologies such as HIV and hepatitis C. We evaluated such a strategy for HSV-2 serology by using an easily performed commercial test, biokitHSV-2 rapid test ("Biokit"; Biokit USA, Lexington MA as a confirmatory test for the widely used gG-2 specific serology ("Focus;" HerpeSelect HSV-2 ELISA; Focus Diagnostics, Cypress CA. Methods We tested 782 sera by Focus HSV-2 ELISA, Biokit, and the current gold standard test, Western blot (WB. Results The positive predictive value of the Focus HSV-2 ELISA increased from 80.5% to 95.6% when Biokit testing was performed on sera that were initially positive by Focus HSV-2 ELISA. Confirmatory testing increased the specificity markedly among sera with Focus EIA values between 1.1 and 3.5: only 35% of low positive (index values 1.1–3.5 Focus HSV-2 ELISA results confirmed as positive by Biokit and WB compared with 92% of those with index values >3.5. Mathematical modeling of the data resulted in expected positive predictive values over 98% for populations with antibody prevalences typical of clinical practices in the US and Europe. Conclusion Confirmatory Biokit testing of positive Focus HSV-2 ELISA results is fast, easy, and effective in reducing falsely positive HSV-2 antibody results. Patients, clinicians, and laboratories could benefit from the enhanced specificity of this simple HSV-2 serologic test combination.

  15. Etiologic predictive value of a rapid immunoassay for the detection of group A Streptococcus antigen from throat swabs in patients presenting with a sore throat.

    Science.gov (United States)

    Orda, Ulrich; Gunnarsson, Ronny; Orda, Sabine; Fitzgerald, Mark; Rofe, Geoff; Dargan, Anna

    2016-04-01

    Clinical reasoning utilizing certain symptoms and scores has not proven to be a reliable decision-making tool to determine whether or not to suspect a group A Streptococcus (GAS) infection in the patient presenting with a sore throat. Culture as the so-called 'gold standard' is impracticable because it takes 1 to 2 days (and even longer in remote locations) for a result, and thus treatment decisions will be made without the result available. Rapid diagnostic antigen tests have demonstrated sufficient sensitivities and specificities in detecting GAS antigens to identify GAS throat infections. Throat swab samples were collected from patients attending the Mount Isa Hospital emergency department for a sore throat; these samples were compared to swab samples collected from healthy controls who did not have a sore throat. Both groups were aged 3-15 years. All swab samples were analyzed with a point-of-care test (Alere Test Pack +Plus with OBC Strep A). The etiologic predictive value (EPV) of the throat swab was calculated. The 95% confidence interval for positive EPV was 88-100% and for negative EPV was 97-99%, depending on assumptions made. This study demonstrates that the point-of-care test Alere Test Pack +Plus Strep A has a high positive predictive value and is able to rule in GAS infection as long as the proportion of carriers is low. Also the negative predictive value for ruling out GAS as the etiologic agent is very high irrespective of the carrier rate. Hence, this test is always useful to rule out GAS infection. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  16. Adjustable virtual pore-size filter for automated sample preparation using acoustic radiation force

    Energy Technology Data Exchange (ETDEWEB)

    Jung, B; Fisher, K; Ness, K; Rose, K; Mariella, R

    2008-05-22

    We present a rapid and robust size-based separation method for high throughput microfluidic devices using acoustic radiation force. We developed a finite element modeling tool to predict the two-dimensional acoustic radiation force field perpendicular to the flow direction in microfluidic devices. Here we compare the results from this model with experimental parametric studies including variations of the PZT driving frequencies and voltages as well as various particle sizes and compressidensities. These experimental parametric studies also provide insight into the development of an adjustable 'virtual' pore-size filter as well as optimal operating conditions for various microparticle sizes. We demonstrated the separation of Saccharomyces cerevisiae and MS2 bacteriophage using acoustic focusing. The acoustic radiation force did not affect the MS2 viruses, and their concentration profile remained unchanged. With optimized design of our microfluidic flow system we were able to achieve yields of > 90% for the MS2 with > 80% of the S. cerevisiae being removed in this continuous-flow sample preparation device.

  17. Direction selective structural-acoustic coupled radiator

    Science.gov (United States)

    Seo, Hee-Seon; Kim, Yang-Hann

    2005-04-01

    This paper presents a method of designing a structural-acoustic coupled radiator that can emit sound in the desired direction. The structural-acoustic coupled system is consisted of acoustic spaces and wall. The wall composes two plates and an opening, and the wall separates one space that is highly reverberant and the other that is unbounded without any reflection. An equation is developed that predicts energy distribution and energy flow in the two spaces separated by the wall, and its computational examples are presented including near field acoustic characteristics. To design the directional coupled radiator, Pareto optimization method is adapted. An objective is selected to maximize radiation power on a main axis and minimize a side lobe level and a subjective is selected direction of the main axis and dimensions of the walls geometry. Pressure and intensity distribution of the designed radiator is also presented.

  18. Envelope Solitons in Acoustically Dispersive Vitreous Silica

    Science.gov (United States)

    Cantrell, John H.; Yost, William T.

    2012-01-01

    Acoustic radiation-induced static strains, displacements, and stresses are manifested as rectified or dc waveforms linked to the energy density of an acoustic wave or vibrational mode via the mode nonlinearity parameter of the material. An analytical model is developed for acoustically dispersive media that predicts the evolution of the energy density of an initial waveform into a series of energy solitons that generates a corresponding series of radiation-induced static strains (envelope solitons). The evolutionary characteristics of the envelope solitons are confirmed experimentally in Suprasil W1 vitreous silica. The value (-11.9 plus or minus 1.43) for the nonlinearity parameter, determined from displacement measurements of the envelope solitons via a capacitive transducer, is in good agreement with the value (-11.6 plus or minus 1.16) obtained independently from acoustic harmonic generation measurements. The agreement provides strong, quantitative evidence for the validity of the model.

  19. Vibro-acoustics of lightweight sandwich structures

    CERN Document Server

    Lu, Tianjian

    2014-01-01

    Vibro-Acoustics of Lightweight Sandwich Structures introduces the study of the coupled vibration and acoustic behavior of lightweight sandwich structures in response to harmonic force and sound pressure. This book focuses on the theoretical modeling and experimental investigation of lightweight sandwich structures in order to provide a predictive framework for vibro-acoustic characteristics of typical engineering structures. Furthermore, by developing solution tools, it concentrates on the influence of key systematic parameters leading to effective guidance for optimal structure design toward lightweight, high-stiffness and superior sound insulation capability. This book is intended for researchers, scientists, engineers and graduate students in mechanical engineering especially in structural mechanics, mechanics and acoustics. Fengxian Xin and Tianjian Lu both work at the School of Aerospace, Xi’an Jiaotong University.

  20. Modeling cavitation in a rapidly changing pressure field - application to a small ultrasonic horn.

    Science.gov (United States)

    Žnidarčič, Anton; Mettin, Robert; Dular, Matevž

    2015-01-01

    Ultrasonic horn transducers are frequently used in applications of acoustic cavitation in liquids. It has been observed that if the horn tip is sufficiently small and driven at high amplitude, cavitation is very strong, and the tip can be covered entirely by the gas/vapor phase for longer time intervals. A peculiar dynamics of the attached cavity can emerge with expansion and collapse at a self-generated frequency in the subharmonic range, i.e. below the acoustic driving frequency. The term "acoustic supercavitation" was proposed for this type of cavitation Žnidarčič et al. (2014) [1]. We tested several established hydrodynamic cavitation models on this problem, but none of them was able to correctly predict the flow features. As a specific characteristic of such acoustic cavitation problems lies in the rapidly changing driving pressures, we present an improved approach to cavitation modeling, which does not neglect the second derivatives in the Rayleigh-Plesset equation. Comparison with measurements of acoustic supercavitation at an ultrasonic horn of 20kHz frequency revealed a good agreement in terms of cavity dynamics, cavity volume and emitted pressure pulsations. The newly developed cavitation model is particularly suited for simulation of cavitating flow in highly fluctuating driving pressure fields. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. A viscoelastic model for the prediction of transcranial ultrasound propagation: application for the estimation of shear acoustic properties in the human skull

    Science.gov (United States)

    Pichardo, Samuel; Moreno-Hernández, Carlos; Drainville, Robert Andrew; Sin, Vivian; Curiel, Laura; Hynynen, Kullervo

    2017-09-01

    A better understanding of ultrasound transmission through the human skull is fundamental to develop optimal imaging and therapeutic applications. In this study, we present global attenuation values and functions that correlate apparent density calculated from computed tomography scans to shear speed of sound. For this purpose, we used a model for sound propagation based on the viscoelastic wave equation (VWE) assuming isotropic conditions. The model was validated using a series of measurements with plates of different plastic materials and angles of incidence of 0°, 15° and 50°. The optimal functions for transcranial ultrasound propagation were established using the VWE, scan measurements of transcranial propagation with an angle of incidence of 40° and a genetic optimization algorithm. Ten (10) locations over three (3) skulls were used for ultrasound frequencies of 270 kHz and 836 kHz. Results with plastic materials demonstrated that the viscoelastic modeling predicted both longitudinal and shear propagation with an average (±s.d.) error of 9(±7)% of the wavelength in the predicted delay and an error of 6.7(±5)% in the estimation of transmitted power. Using the new optimal functions of speed of sound and global attenuation for the human skull, the proposed model predicted the transcranial ultrasound transmission for a frequency of 270 kHz with an expected error in the predicted delay of 5(±2.7)% of the wavelength. The sound propagation model predicted accurately the sound propagation regardless of either shear or longitudinal sound transmission dominated. For 836 kHz, the model predicted accurately in average with an error in the predicted delay of 17(±16)% of the wavelength. Results indicated the importance of the specificity of the information at a voxel level to better understand ultrasound transmission through the skull. These results and new model will be very valuable tools for the future development of transcranial applications of

  2. Plasma Leucine-Rich α-2-Glycoprotein 1 Predicts Rapid eGFR Decline and Albuminuria Progression in Type 2 Diabetes Mellitus.

    Science.gov (United States)

    Liu, Jian-Jun; Pek, Sharon Li Ting; Ang, Kevin; Tavintharan, Subramaniam; Lim, Su Chi

    2017-10-01

    Abnormal angiogenesis plays an important role in pathogenesis of diabetic kidney disease (DKD). Leucine-rich α-2 glycoprotein 1 (LRG1) is a newly identified angiogenic factor. To study whether plasma LRG1 may independently predict progression of DKD in individuals with type 2 diabetes mellitus (T2DM). Prospective cohort study in a regional hospital. In total, 1226 T2DM participants were followed for a mean ± standard deviation (SD) of 3.1 ± 0.4 years. Albuminuria progression was defined as elevation in albuminuria level to a higher category. Chronic kidney disease (CKD) progression [rapid estimated glomerular filtration rate (eGFR) decline] was defined as a 40% or greater deterioration in eGFR in 3 years. Both participants with albuminuria progression and those with CKD progression had higher plasma LRG1 levels at baseline. LRG1 independently predicted albuminuria progression above traditional risk factors, including baseline eGFR and urine albumin to creatinine ratio. A 1-SD increment in LRG1 was associated with a 1.26-fold [95% confidence interval (CI), 1.04 to 1.53, P = 0.018] higher adjusted risk for albuminuria progression. The association of LRG1 with microalbuminuria to macroalbuminuria progression was stronger than its association with normoalbuminuria to microalbuminuria progression [odds ratio (OR), 1.51; 95% CI, 1.04 to 2.18, P = 0.029 vs OR, 1.09; 95% CI, 0.86 to 1.37, P = 0.486, per 1-SD LRG1 increment]. Also, LRG1 independently predicted CKD progression above traditional risk factors. A 1-SD increment in LRG1 was associated with a 1.48-fold (95% CI, 1.04 to 2.11, P = 0.032) higher adjusted risk for CKD progression. Plasma LRG1 predicts both albuminuria and CKD progression beyond traditional risk factors. It may play a role in the pathologic pathway leading to progression of DKD in T2DM.

  3. An experimental analysis of fracture mechanisms by acoustic ...

    African Journals Online (AJOL)

    Burst pressure prediction in graphite/epoxy pressure vessels using neural networks and acoustic emission amplitude data, Materials Evaluation, Vol.54(6), pp.744 ... of emission acoustic signals collected during tensile tests on unidirectional glass/polyester composite using supervised and unsupervised classifiers, NDT & E.

  4. A Novel 7-Single Nucleotide Polymorphism-Based Clonotyping Test Allows Rapid Prediction of Antimicrobial Susceptibility of Extraintestinal Escherichia coli Directly From Urine Specimens

    Science.gov (United States)

    Tchesnokova, Veronika; Avagyan, Hovhannes; Billig, Mariya; Chattopadhyay, Sujay; Aprikian, Pavel; Chan, Diana; Pseunova, Julietta; Rechkina, Elena; Riddell, Kim; Scholes, Delia; Fang, Ferric C.; Johnson, James R.; Sokurenko, Evgeni V.

    2016-01-01

    Background. Escherichia coli is a highly clonal pathogen. Extraintestinal isolates belong to a limited number of genetically related groups, which often exhibit characteristic antimicrobial resistance profiles. Methods. We developed a rapid clonotyping method for extraintestinal E coli based on detection of the presence or absence of 7 single nucleotide polymorphisms (SNPs) within 2 genes (fumC and fimH). A reference set of 2559 E coli isolates, primarily of urinary origin, was used to predict the resolving power of the 7-SNP-based typing method, and 582 representative strains from this set were used to evaluate test robustness. Results. Fifty-four unique SNP combinations (“septatypes”) were identified in the reference strains. These septatypes yielded a clonal group resolution power on par with that of traditional multilocus sequence typing. In 72% of isolates, septatype identity predicted sequence type identity with at least 90% (mean, 97%) accuracy. Most septatypes exhibited highly distinctive antimicrobial susceptibility profiles. The 7-SNP-based test could be performed with high specificity and sensitivity using single or multiplex conventional polymerase chain reaction (PCR) and quantitative PCR. In the latter format, E coli presence and septatype identity were determined directly in urine specimens within 45 minutes with bacterial loads as low as 102 colony-forming units/mL and, at clinically significant bacterial loads, with 100% sensitivity and specificity. Conclusions. 7-SNP-based typing of E coli can be used for both epidemiological studies and clinical diagnostics, which could greatly improve the empirical selection of antimicrobial therapy. PMID:26925427

  5. Verification of Ares I Liftoff Acoustic Environments via the Ares I Scale Model Acoustic Test

    Science.gov (United States)

    Counter, Douglas D.; Houston, Janice D.

    2012-01-01

    Launch environments, such as Liftoff Acoustic (LOA) and Ignition Overpressure (IOP), are important design factors for any vehicle and are dependent upon the design of both the vehicle and the ground systems. The NASA Constellation Program had several risks to the development of the Ares I vehicle linked to LOA which are used in the development of the vibro-acoustic environments. The risks included cost, schedule and technical impacts for component qualification due to high predicted vibro-acoustic environments. One solution is to mitigate the environment at the component level. However, where the environment is too severe to mitigate at the component level, reduction of the launch environments is required. The Ares I Scale Model Acoustic Test (ASMAT) program was implemented to verify the predicted Ares I launch environments and to determine the acoustic reduction for the LOA environment with an above deck water sound suppression system. The test article included a 5% scale Ares I vehicle model, tower and Mobile Launcher. Acoustic and pressure data were measured by approximately 200 instruments. The ASMAT results are compared to the Ares I LOA predictions and water suppression effectiveness results are presented.

  6. Verification of Ares I Liftoff Acoustic Environments via the Ares Scale Model Acoustic Test

    Science.gov (United States)

    Counter, Douglas D.; Houston, Janice D.

    2012-01-01

    Launch environments, such as Liftoff Acoustic (LOA) and Ignition Overpressure (IOP), are important design factors for any vehicle and are dependent upon the design of both the vehicle and the ground systems. The NASA Constellation Program had several risks to the development of the Ares I vehicle linked to LOA which are used in the development of the vibro-acoustic environments. The risks included cost, schedule and technical impacts for component qualification due to high predicted vibro-acoustic environments. One solution is to mitigate the environment at the component level. However, where the environment is too severe to mitigate at the component level, reduction of the launch environments is required. The Ares I Scale Model Acoustic Test (ASMAT) program was implemented to verify the predicted Ares I launch environments and to determine the acoustic reduction for the LOA environment with an above deck water sound suppression system. The test article included a 5% scale Ares I vehicle model, tower and Mobile Launcher. Acoustic and pressure data were measured by approximately 200 instruments. The ASMAT results are compared to the Ares I LOA predictions and water suppression effectiveness results are presented.

  7. 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...

  8. 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...

  9. Deep Water Ocean Acoustics

    Science.gov (United States)

    2016-08-03

    for including this in acoustic models . Experimental analysis is combined with model development to isolate specific physics and improve our...under- ice scattering, bathymetric diffraction and the application of the ocean acoustic Parabolic Equation to infrasound. 2. Tasks a. Task 1: Basin...of Japan received at the CTBTO HA03 station in Juan Fernandez Chile , are a treasure trove of long-range low frequency acoustic propagation. In

  10. Prediction

    CERN Document Server

    Sornette, Didier

    2010-01-01

    This chapter first presents a rather personal view of some different aspects of predictability, going in crescendo from simple linear systems to high-dimensional nonlinear systems with stochastic forcing, which exhibit emergent properties such as phase transitions and regime shifts. Then, a detailed correspondence between the phenomenology of earthquakes, financial crashes and epileptic seizures is offered. The presented statistical evidence provides the substance of a general phase diagram for understanding the many facets of the spatio-temporal organization of these systems. A key insight is to organize the evidence and mechanisms in terms of two summarizing measures: (i) amplitude of disorder or heterogeneity in the system and (ii) level of coupling or interaction strength among the system's components. On the basis of the recently identified remarkable correspondence between earthquakes and seizures, we present detailed information on a class of stochastic point processes that has been found to be particu...

  11. Rapid prediction of phenolic compounds and antioxidant activity of Sudanese honey using Raman and Fourier transform infrared (FT-IR) spectroscopy.

    Science.gov (United States)

    Tahir, Haroon Elrasheid; Xiaobo, Zou; Zhihua, Li; Jiyong, Shi; Zhai, Xiaodong; Wang, Sheng; Mariod, Abdalbasit Adam

    2017-07-01

    Fourier transform infrared with attenuated total reflectance (FTIR-ATR) and Raman spectroscopy combined with partial least square regression (PLSR) were applied for the prediction of phenolic compounds and antioxidant activity in honey. Standards of catechin, syringic, vanillic, and chlorogenic acids were used for the identification and quantification of the individual phenolic compounds in six honey varieties using HPLC-DAD. Total antioxidant activity (TAC) and ferrous chelating capacity were measured spectrophotometrically. For the establishment of PLSR model, Raman spectra with Savitzky-Golay smoothing in wavenumber region 1500-400cm-1 was used while for FTIR-ATR the wavenumber regions of 1800-700 and 3000-2800cm-1 with multiplicative scattering correction (MSC) and Savitzky-Golay smoothing were used. The determination coefficients (R2) were ranged from 0.9272 to 0.9992 for Raman while from 0.9461 to 0.9988 for FTIT-ART. The FTIR-ATR and Raman demonstrated to be simple, rapid and nondestructive methods to quantify phenolic compounds and antioxidant activities in honey. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Laboratory for Structural Acoustics

    Data.gov (United States)

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

  13. 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.

  14. 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...

  15. 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.

  16. Acoustic Technology Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — This laboratory contains an electro-magnetic worldwide data collection and field measurement capability in the area of acoustic technology. Outfitted by NASA Langley...

  17. Matrix method for acoustic levitation simulation.

    Science.gov (United States)

    Andrade, Marco A B; Perez, Nicolas; Buiochi, Flavio; Adamowski, Julio C

    2011-08-01

    A matrix method is presented for simulating acoustic levitators. A typical acoustic levitator consists of an ultrasonic transducer and a reflector. The matrix method is used to determine the potential for acoustic radiation force that acts on a small sphere in the standing wave field produced by the levitator. The method is based on the Rayleigh integral and it takes into account the multiple reflections that occur between the transducer and the reflector. The potential for acoustic radiation force obtained by the matrix method is validated by comparing the matrix method results with those obtained by the finite element method when using an axisymmetric model of a single-axis acoustic levitator. After validation, the method is applied in the simulation of a noncontact manipulation system consisting of two 37.9-kHz Langevin-type transducers and a plane reflector. The manipulation system allows control of the horizontal position of a small levitated sphere from -6 mm to 6 mm, which is done by changing the phase difference between the two transducers. The horizontal position of the sphere predicted by the matrix method agrees with the horizontal positions measured experimentally with a charge-coupled device camera. The main advantage of the matrix method is that it allows simulation of non-symmetric acoustic levitators without requiring much computational effort.

  18. Real-time system for studies of the effects of acoustic feedback on animal vocalizations.

    Directory of Open Access Journals (Sweden)

    Mike eSkocik

    2013-01-01

    Full Text Available Studies of behavioral and neural responses to distorted auditory feedback can help shed light on the neural mechanisms of animal vocalizations. We describe an apparatus for generating real-time acoustic feedback. The system can very rapidly detect acoustic features in a song and output acoustic signals if the detected features match the desired acoustic template. The system uses spectrogram-based detection of acoustic elements. It is low-cost and can be programmed for a variety of behavioral experiments requiring acoustic feedback or neural stimulation. We use the system to study the effects of acoustic feedback on birds' vocalizations and demonstrate that such an acoustic feedback can cause both immediate and long-term changes to birds’ songs.

  19. Active micromixer using surface acoustic wave streaming

    Science.gov (United States)

    Branch,; Darren W. , Meyer; Grant D. , Craighead; Harold, G [Ithaca, NY

    2011-05-17

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

  20. Clinical and acoustical variability in hypokinetic dysarthria

    Energy Technology Data Exchange (ETDEWEB)

    Metter, E.J.; Hanson, W.R.

    1986-10-01

    Ten male patients with parkinsonism secondary to Parkinson's disease or progressive supranuclear palsy had clinical neurological, speech, and acoustical speech evaluations. In addition, seven of the patients were evaluated by x-ray computed tomography (CT) and (F-18)-fluorodeoxyglucose (FDG) positron emission tomography (PET). Extensive variability of speech features, both clinical and acoustical, were found and seemed to be independent of the severity of any parkinsonian sign, CT, or FDG PET. In addition, little relationship existed between the variability across each measured speech feature. What appeared to be important for the appearance of abnormal acoustic measures was the degree of overall severity of the dysarthria. These observations suggest that a better understanding of hypokinetic dysarthria may result from more extensive examination of the variability between patients. Emphasizing a specific feature such as rapid speaking rate in characterizing hypokinetic dysarthria focuses on a single and inconstant finding in a complex speech pattern.

  1. Instrumentation Suite for Acoustic Propagation Measurements in Complex Shallow Water Environments

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Obtain at-sea measurements to test theoretical and modeling predictions of acoustic propagation in dynamic, inhomogeneous, and nonisotropic shallow water...

  2. Revealing, identifying and assessing ''non-predictable flaws'', crack type IV, by quantitative acoustic emission non-destructive inspection technology, photo-elastic and metallurgical methods

    Energy Technology Data Exchange (ETDEWEB)

    Muravin, G.; Mizrahi, I. [Margan Physical Diagnostics Ltd., Netanya (Israel); Frage, N. [Ben-Gurion Univ. of the Negev, Beer-Sheva (Israel)

    2010-11-15

    QAE NDI technology has been adapted to revealing, identifying and assessing one type of previously non-predictable failure of high energy equipment and piping, known as crack type IV. The research established the following: Cracks of type IV correspond to transverse shear crack mode II, according to the classification used in fracture mechanics and the physics of solids. The length of crack mode II jumps, the velocity of it propagation are significantly higher than in case crack mode I under the same loads. The earliest quantitative statistical Acoustic Emission (AE) indications and peculiarities necessary and sufficient to reveal cracks in specimens loaded by tension or shear loads, especially the differences in the AE power, median Energy, Average Frequency and Hit Rate of the AE signals flow. etc. Based on the findings described above have been formulated requirements and technological solutions for revealing, typifying and assessing crack IV. (Copyright copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  3. Particle filtering based structural assessment with acoustic emission sensing

    Science.gov (United States)

    Yan, Wuzhao; Abdelrahman, Marwa; Zhang, Bin; Ziehl, Paul

    2017-02-01

    Nuclear structures are designed to withstand severe loading events under various stresses. Over time, aging of structural systems constructed with concrete and steel will occur. This deterioration may reduce service life of nuclear facilities and/or lead to unnecessary or untimely repairs. Therefore, online monitoring of structures in nuclear power plants and waste storage has drawn significant attention in recent years. Of many existing non-destructive evaluation and structural monitoring approaches, acoustic emission is promising for assessment of structural damage because it is non-intrusive and is sensitive to corrosion and crack growth in reinforced concrete elements. To provide a rapid, actionable, and graphical means for interpretation Intensity Analysis plots have been developed. This approach provides a means for classification of damage. Since the acoustic emission measurement is only an indirect indicator of structural damage, potentially corrupted by non-genuine data, it is more suitable to estimate the states of corrosion and cracking in a Bayesian estimation framework. In this paper, we will utilize the accelerated corrosion data from a specimen at the University of South Carolina to develop a particle filtering-based diagnosis and prognosis algorithm. Promising features of the proposed algorithm are described in terms of corrosion state estimation and prediction of degradation over time to a predefined threshold.

  4. Real-time reverberation inversion for acoustic seabed properties

    NARCIS (Netherlands)

    Vossen, R. van; Colin, M.; Benders, F.; Ainslie, M.A.; Eidem, E.J.; Chalindar, B; Juhel, B.; Dybedal, J.; Olsen, G.K.; Ivansson, S.; Abrahamsson, L.

    2011-01-01

    Accurate environmental information is required for obtaining reliable predictions for the performance of low-frequency active sonar (LFAS) systems. This environmental information is, however, often unreliable or unavailable. For example, the acoustic seabed parameters relevant for the scattering and

  5. Investigation into the Effect of Acoustic Radiation Force and Acoustic Streaming on Particle Patterning in Acoustic Standing Wave Fields

    Science.gov (United States)

    Yang, Yanye; Ni, Zhengyang; Guo, Xiasheng; Luo, Linjiao; Tu, Juan; Zhang, Dong

    2017-01-01

    Acoustic standing waves have been widely used in trapping, patterning, and manipulating particles, whereas one barrier remains: the lack of understanding of force conditions on particles which mainly include acoustic radiation force (ARF) and acoustic streaming (AS). In this paper, force conditions on micrometer size polystyrene microspheres in acoustic standing wave fields were investigated. The COMSOL® Mutiphysics particle tracing module was used to numerically simulate force conditions on various particles as a function of time. The velocity of particle movement was experimentally measured using particle imaging velocimetry (PIV). Through experimental and numerical simulation, the functions of ARF and AS in trapping and patterning were analyzed. It is shown that ARF is dominant in trapping and patterning large particles while the impact of AS increases rapidly with decreasing particle size. The combination of using both ARF and AS for medium size particles can obtain different patterns with only using ARF. Findings of the present study will aid the design of acoustic-driven microfluidic devices to increase the diversity of particle patterning. PMID:28753955

  6. Investigation into the Effect of Acoustic Radiation Force and Acoustic Streaming on Particle Patterning in Acoustic Standing Wave Fields

    Directory of Open Access Journals (Sweden)

    Shilei Liu

    2017-07-01

    Full Text Available Acoustic standing waves have been widely used in trapping, patterning, and manipulating particles, whereas one barrier remains: the lack of understanding of force conditions on particles which mainly include acoustic radiation force (ARF and acoustic streaming (AS. In this paper, force conditions on micrometer size polystyrene microspheres in acoustic standing wave fields were investigated. The COMSOL® Mutiphysics particle tracing module was used to numerically simulate force conditions on various particles as a function of time. The velocity of particle movement was experimentally measured using particle imaging velocimetry (PIV. Through experimental and numerical simulation, the functions of ARF and AS in trapping and patterning were analyzed. It is shown that ARF is dominant in trapping and patterning large particles while the impact of AS increases rapidly with decreasing particle size. The combination of using both ARF and AS for medium size particles can obtain different patterns with only using ARF. Findings of the present study will aid the design of acoustic-driven microfluidic devices to increase the diversity of particle patterning.

  7. An Investigation into Wind Turbine Acoustic Noise Variability

    Science.gov (United States)

    Buck, Steven

    Wind turbine acoustic noise has been the subject of significant research in recent decades due to rapid growth in the wind energy industry. Available space with a reliable wind resource and that does not reside near populated areas is becoming extremely scarce, particularly in Europe. This decline in available space then results in a heightened need for wind turbine designs to be optimized for both acoustic emission and power-performance. Due to highly variable operating conditions, wind turbine acoustic noise emission may deviate from design levels, causing irritation to local residents and requiring reduced power production of the contributing turbines. The objective of this dissertation is to investigate two parameters that contribute to this variability--atmospheric turbulence in the inflow field, and aerodynamic flow separation--such that they may be more fully understood and properly accounted for in design. Results are achieved through an extensive experimental campaign on a full-scale turbine equipped with a thorough sensor network. Several novel flow characterization methods are developed, including a method of in-situ turbulence measurement using blade-mounted accelerometers. Turbulent inflow noise is shown to dominate the low frequency portion of the emitted spectrum for normal turbine operation and increases levels by as much as 6 dB for the conditions observed at the research facility. Experimental observations are typically within 2-3 dB of a commonly implemented noise prediction model. Finally, a study into the effects of high angle of attack operation shows that aerodynamic flow separation--detected using static pressure sensors along one blade of the turbine--can increase overall noise levels by more than 10 dB, thus dominating turbulent inflow noise at low frequencies. The studies of both turbulent inflow noise and flow separation noise represent the most thorough experimental observations and analysis of the respective noise mechanisms on a full

  8. Acoustic streaming of a sharp edge.

    Science.gov (United States)

    Ovchinnikov, Mikhail; Zhou, Jianbo; Yalamanchili, Satish

    2014-07-01

    Anomalous acoustic streaming is observed emanating from sharp edges of solid bodies that are vibrating in fluids. The streaming velocities can be orders of magnitude higher than expected from the Rayleigh streaming at similar amplitudes of vibration. Acoustic velocity of fluid relative to a solid body diverges at a sharp edge, giving rise to a localized time-independent body force acting on the fluid. This force results in a formation of a localized jet. Two-dimensional numerical simulations are performed to predict acoustic streaming for low amplitude vibration using two methods: (1) Steady-state solution utilizing perturbation theory and (2) direct transient solution of the Navier-Stokes equations. Both analyses agree with each other and correctly predict the streaming of a sharp-edged vibrating blade measured experimentally. The origin of the streaming can be attributed to the centrifugal force of the acoustic fluid flow around a sharp edge. The dependence of this acoustic streaming on frequency and velocity is examined using dimensional analysis. The dependence law is devised and confirmed by numerical simulations.

  9. Validation of high frequency acoustic target modeling

    NARCIS (Netherlands)

    Quesson, B.A.J.; Schippers, P.; Groen, J.; Sabel, J.C.; Driessen, F.P.G.

    2005-01-01

    The underwater acoustics group at TNO Defense, Security and Safety has developed two simulation software programs named ALMOST and SIMONA. The first is already commercially used and aims at sonar performance prediction, whereas the second one is used as a tool to generate simulated data for mine

  10. Parametric Room Acoustic Workflows

    DEFF Research Database (Denmark)

    Parigi, Dario; Svidt, Kjeld; Molin, Erik

    2017-01-01

    The paper investigates and assesses different room acoustics software and the opportunities they offer to engage in parametric acoustics workflow and to influence architectural designs. The first step consists in the testing and benchmarking of different tools on the basis of accuracy, speed...

  11. Mutual-probability prediction and higher-order correlation effects among acoustic, light and electromagnetic waves in a video display terminal environment

    Science.gov (United States)

    Ohta, Mitsuo; Ogawa, Hitoshi; Ikuta, Akira

    2005-08-01

    A probabilistic signal processing method, with which is possible to get some methodological suggestion to the measurement method of correlative and/or accumulative effects in the compound environment of sound, light and electromagnetic (EM) waves is discussed. In order to extract various types of latent interrelation characteristics among wave environmental factors leaked from an actually operating video display terminal (VDT), an extended regression system model, hierarchically reflecting not only linear correlation information but also nonlinear correlation information, is first introduced, especially from a viewpoint of 'relationism-first'. Then, through estimating each regression parameter of this model, some original evaluation methods for predicting a whole probability distribution form, from one another, are proposed. Finally, the effectiveness of the methods is experimentally confirmed, by applying them to the actual observed data leaked by a VDT with some television games. To cite this article: M. Ohta et al., C. R. Mecanique 333 (2005).

  12. 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.

  13. 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....

  14. 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.

  15. 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...

  16. A Rapid Bedside Screen to Predict Unplanned Hospitalization and Death in Outpatients With Cirrhosis: A Prospective Evaluation of the Clinical Frailty Scale.

    Science.gov (United States)

    Tandon, Puneeta; Tangri, Navdeep; Thomas, Lesley; Zenith, Laura; Shaikh, Tahira; Carbonneau, Michelle; Ma, Mang; Bailey, Robert J; Jayakumar, Saumya; Burak, Kelly W; Abraldes, Juan G; Brisebois, Amanda; Ferguson, Thomas; Majumdar, Sumit R

    2016-12-01

    Screening tools to determine which outpatients with cirrhosis are at highest risk for unplanned hospitalization are lacking. Frailty is a novel prognostic factor but conventional screening for frailty is time consuming. We evaluated the ability of a 1 min bedside screen (Clinical Frailty Scale (CFS)) to predict unplanned hospitalization or death in outpatients with cirrhosis and compared the CFS with two conventional frailty measures (Fried Frailty Criteria (FFC) and Short Physical Performance Battery (SPPB)). We prospectively enrolled consecutive outpatients from three tertiary care liver clinics. Frailty was defined by CFS >4. The primary outcome was the composite of unplanned hospitalization or death within 6 months of study entry. A total of 300 outpatients were enrolled (mean age 57 years, 35% female, 81% white, 66% hepatitis C or alcohol-related liver disease, mean Model for End-Stage Liver Disease (MELD) score 12, 28% with ascites). Overall, 54 (18%) outpatients were frail and 91 (30%) patients had an unplanned hospitalization or death within 6 months. CFS >4 was independently associated with increased rates of unplanned hospitalization or death (57% frail vs. 24% not frail, adjusted odds ratio 3.6; 95% confidence interval (CI): 1.7-7.5; P=0.0008) and there was a dose response (adjusted odds ratio 1.9 per 1-unit increase in CFS, 95% CI: 1.4-2.6; P4 had a greater discrimination (c-statistic=0.84) than models using FFC or SPPB. Frailty is strongly and independently associated with an increased risk of unplanned hospitalization or death in outpatients with cirrhosis. The CFS is a rapid screen that could be easily adopted in liver clinics to identify those at highest risk of adverse events.

  17. Acoustic communication in insect disease vectors

    Directory of Open Access Journals (Sweden)

    Felipe de Mello Vigoder

    2013-01-01

    Full Text Available Acoustic signalling has been extensively studied in insect species, which has led to a better understanding of sexual communication, sexual selection and modes of speciation. The significance of acoustic signals for a blood-sucking insect was first reported in the XIX century by Christopher Johnston, studying the hearing organs of mosquitoes, but has received relatively little attention in other disease vectors until recently. Acoustic signals are often associated with mating behaviour and sexual selection and changes in signalling can lead to rapid evolutionary divergence and may ultimately contribute to the process of speciation. Songs can also have implications for the success of novel methods of disease control such as determining the mating competitiveness of modified insects used for mass-release control programs. Species-specific sound “signatures” may help identify incipient species within species complexes that may be of epidemiological significance, e.g. of higher vectorial capacity, thereby enabling the application of more focussed control measures to optimise the reduction of pathogen transmission. Although the study of acoustic communication in insect vectors has been relatively limited, this review of research demonstrates their value as models for understanding both the functional and evolutionary significance of acoustic communication in insects.

  18. Acoustic communication in insect disease vectors.

    Science.gov (United States)

    Vigoder, Felipe de Mello; Ritchie, Michael Gordon; Gibson, Gabriella; Peixoto, Alexandre Afranio

    2013-01-01

    Acoustic signalling has been extensively studied in insect species, which has led to a better understanding of sexual communication, sexual selection and modes of speciation. The significance of acoustic signals for a blood-sucking insect was first reported in the XIX century by Christopher Johnston, studying the hearing organs of mosquitoes, but has received relatively little attention in other disease vectors until recently. Acoustic signals are often associated with mating behaviour and sexual selection and changes in signalling can lead to rapid evolutionary divergence and may ultimately contribute to the process of speciation. Songs can also have implications for the success of novel methods of disease control such as determining the mating competitiveness of modified insects used for mass-release control programs. Species-specific sound "signatures" may help identify incipient species within species complexes that may be of epidemiological significance, e.g. of higher vectorial capacity, thereby enabling the application of more focussed control measures to optimise the reduction of pathogen transmission. Although the study of acoustic communication in insect vectors has been relatively limited, this review of research demonstrates their value as models for understanding both the functional and evolutionary significance of acoustic communication in insects.

  19. Integrated acoustic-resolution and optical-resolution photoacoustic microscopy using a single multifunctional acoustic lens

    Science.gov (United States)

    Guo, Heng; Xi, Lei

    2016-10-01

    With the rapid development of photoacoustic imaging, it has been widely used in various research fields such as biology, medicine and nanotechnology. Due to the huge difference among photoacoustic imaging systems, it is hard to integrate them in one platform. To solve this problem, we propose to develop a new universal photoacoustic imaging platform that integrates acoustic-resolution photoacoustic microscopy and optical-resolution photoacoustic microscopy through a multifunctional liquid lens. This lens takes advantage of an inherently low acoustic impedance and a tunable focal length that was characterized by the infusion volume of the liquid. In this paper, the liquid lens was used to realize confocal of laser illumination and acoustic detection for both acoustic-resolution and optical-resolution photoacoustic microscopy. The home-made polyvinylidene fluoride (PVDF) acoustic transducer had a center frequency of 10MHz and -6dB frequency spectrum from 4MHz to 15MHz which yielded to an axial resolution of 70 μm. The lateral resolutions of acoustic- and optical-resolution photoacoustic microscopy were evaluated to be 180 μm and 4.8 μm, respectively. The vasculature of rat ears was carried out to evaluate the performance of optical-resolution photoacoustic microscopy.

  20. Evaluating the Acoustic Benefits of Over-the-Rotor Acoustic Treatments Installed on the Advanced Noise Control Fan

    Science.gov (United States)

    Gazella, Matthew R.; Takakura, Tamuto; Sutliff, Daniel L.; Bozak, Richard F.; Tester, Brian J.

    2017-01-01

    Over the last 15 years, over-the-rotor acoustic treatments have been evaluated by NASA with varying success. Recently, NASA has been developing the next generation of over-the-rotor acoustic treatments for fan noise reduction. The NASA Glenn Research Centers Advanced Noise Control Fan was used as a Low Technology Readiness Level test bed. A rapid prototyped in-duct array consisting of 50 microphones was employed, and used to correlate the in-duct analysis to the far-field acoustic levels and to validate an existing beam-former method. The goal of this testing was to improve the Technology Readiness Level of various over-the-rotor acoustic treatments by advancing the understanding of the physical mechanisms and projecting the far-field acoustic benefit.

  1. Acoustic Force Density Acting on Inhomogeneous Fluids in Acoustic Fields

    DEFF Research Database (Denmark)

    Karlsen, Jonas Tobias; Augustsson, Per; Bruus, Henrik

    2016-01-01

    We present a theory for the acoustic force density acting on inhomogeneous fluids in acoustic fields on time scales that are slow compared to the acoustic oscillation period. The acoustic force density depends on gradients in the density and compressibility of the fluid. For microfluidic systems...

  2. Parametric Room Acoustic workflows with real-time acoustic simulation

    DEFF Research Database (Denmark)

    Parigi, Dario

    2017-01-01

    The paper investigates and assesses the opportunities that real-time acoustic simulation offer to engage in parametric acoustics workflow and to influence architectural designs from early design stages......The paper investigates and assesses the opportunities that real-time acoustic simulation offer to engage in parametric acoustics workflow and to influence architectural designs from early design stages...

  3. Evaluation of infrared thermography body temperature and collar-mounted accelerometer and acoustic technology for predicting time of ovulation of cows in a pasture-based system.

    Science.gov (United States)

    Talukder, S; Thomson, P C; Kerrisk, K L; Clark, C E F; Celi, P

    2015-03-01

    This study was conducted to test the hypothesis that the specificity of infrared thermography (IRT) in detecting cows about to ovulate could be improved using different body parts that are less likely to be contaminated by fecal matter. In addition, the combined activity and rumination data captured by accelerometers were evaluated to provide a more accurate indication of ovulation than the activity and rumination data alone. Thermal images of 30 cows were captured for different body areas (eye, ear, muzzle, and vulva) twice daily after AM and PM milking sessions during the entire experimental period. Milk progesterone data and insemination records were used to determine the date of ovulation. Cows were fitted with SCR heat and rumination long-distance tags (SCR HR LD) for 1 month. Activity- and rumination-based estrus alerts were initially identified using default threshold values set by the manufacturer; however, a range of thresholds was also created and tested for both activity and rumination to determine the potential for higher levels of accuracy of ovulation detection. Visual assessment of mounting indicators resulted in 75% sensitivity (Se), 100% specificity (Sp), and 100% positive predictive value (PPV). Overall, IRT showed poor performance for detecting cows about to ovulate. Vulval temperature resulted in the greatest (80%) Sp but the poorest (21%) Se compared with the IRT temperatures of other body areas. The SCR HR LD tags default threshold value resulted in 78% Se, 57% Sp, and 70% PPV. Lowering the activity threshold from the default value improved the sensitivity but created a large number of false positives, which resulted in a decrease in specificity. Lowering the activity threshold to 20 resulted in a detection performance of 80% Se, 94% Sp, and 67% PPV, whereas the rumination levels achieved 35% Se, 69% Sp, and 14% PPV. The area under the curve for the activity level, rumination level, and the combined measures of activity and rumination levels

  4. Seismic resonances of acoustic cavities

    Science.gov (United States)

    Schneider, F. M.; Esterhazy, S.; Perugia, I.; Bokelmann, G.

    2016-12-01

    The goal of an On-Site Inspection (OSI) is to clarify at a possible testsite whether a member state of the Comprehensive nuclear Test Ban Treaty (CTBT)has violated its rules by conducting a underground nuclear test. Compared toatmospheric and underwater tests underground nuclear explosions are the mostdifficult to detect.One primary structural target for the field team during an OSI is the detectionof an underground cavity, created by underground nuclear explosions. Theapplication of seismic-resonances of the cavity for its detection has beenproposed in the CTBT by mentioning "resonance seismometry" as possibletechnique during OSIs. We modeled the interaction of a seismic wave-field withan underground cavity by a sphere filled with an acoustic medium surrounded byan elastic full space. For this setting the solution of the seismic wave-fieldcan be computed analytically. Using this approach the appearance of acousticresonances can be predicted in the theoretical calculations. Resonance peaksappear in the spectrum derived for the elastic domain surrounding the acousticcavity, which scale in width with the density of the acoustic medium. For lowdensities in the acoustic medium as for an gas-filled cavity, the spectralpeaks become very narrow and therefore hard to resolve. The resonancefrequencies, however can be correlated to the discrete set of eigenmodes of theacoustic cavity and can thus be predicted if the dimension of the cavity isknown. Origin of the resonance peaks are internal reverberations of wavescoupling in the acoustic domain and causing an echoing signal that couples outto the elastic domain again. In the gas-filled case the amplitudes in timedomain are very low.Beside theoretical considerations we seek to find real data examples fromsimilar settings. As example we analyze a 3D active seismic data set fromFelsőpetény, Hungary that has been conducted between 2012 and 2014 on behalf ofthe CTBTO. In the subsurface of this area a former clay mine is

  5. Translational illusion of acoustic sources by transformation acoustics.

    Science.gov (United States)

    Sun, Fei; Li, Shichao; He, Sailing

    2017-09-01

    An acoustic illusion of creating a translated acoustic source is designed by utilizing transformation acoustics. An acoustic source shifter (ASS) composed of layered acoustic metamaterials is designed to achieve such an illusion. A practical example where the ASS is made with naturally available materials is also given. Numerical simulations verify the performance of the proposed device. The designed ASS may have some applications in, e.g., anti-sonar detection.

  6. Os efeitos da expansão rápida da maxila sobre a permeabilidade nasal avaliados por rinomanometria e rinometria acústica The effects of rapid maxillary expansion on the nasal patency assessed by rhinomanometry and acoustic rhinometry

    Directory of Open Access Journals (Sweden)

    Bruno Alberto Vidotti

    2008-12-01

    Full Text Available O objetivo deste artigo foi analisar os achados da literatura acerca das repercussões da expansão rápida da maxila (ERM sobre a permeabilidade nasal, pela rinomanometria, que avalia a resistência oferecida pela cavidade nasal à passagem do fluxo aéreo, e pela rinometria acústica, que mede as áreas seccionais e os volumes de diferentes segmentos da cavidade nasal. Estudos que utilizaram a rinomanometria evidenciaram que a ERM determina uma diminuição significativa da resistência nasal, assim como o aumento da área de secção transversa mínima nasal (ASTM em parcela significativa de pacientes. Estudos com rinometria acústica mostraram que a ERM determina, adicionalmente, um aumento significativo do volume da cavidade nasal anterior. Entretanto, é consenso que a ERM não se justifica, por si, como forma de induzir um padrão nasal de respiração em respiradores bucais habituais, apesar dos benefícios trazidos pela ERM em termos de permeabilidade nasal.The aim of this review was to analyze the findings reported in the literature about the effects of rapid maxillary expansion (RME on nasal patency assessed by rhinomanometry, which measures the resistance offered by the nasal cavity to airflow, and acoustic rhinometry, which measures sectional areas and volumes of different segments of the nasal cavity. Studies using rhinomanometry have demonstrated a significant decrease of nasal resistance after RME on a significant number of patients, and also an increase in minimal nasal cross-sectional area. Studies using acoustic rhinometry have additionally shown a significant increase of anterior nasal volume. However, it is a consensus that RME is not justified only for the purpose of inducing a nasal pattern of breathing in oral breathers, despite the improvement of nasal patency caused by RME.

  7. Passive Mode Carbon Nanotube Underwater Acoustic Transducer

    Science.gov (United States)

    2016-09-20

    TECHNOLOGY PARTNERSHIP ENTERPRISE OFFICE NAVAL UNDERSEA WARFARE CENTER 1176 HOWELL ST. CODE 00T2, BLDG. 102T NEWPORT, RI 02841 Serial ...collection. (2) Description of the Prior Art [0004] The principle of thermal active acoustic transduction is that when alternating current is passed through...as the distance from the conductor increases. Based on the rapid production of these temperature waves; the net effect is to produce a periodic

  8. 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...... oscillating plates. Furthermore, under general thermodynamic conditions, we derive the time-dependent first- and second-order equations for the conservation of mass, momentum, and energy. The coupling from fluid equations to particle motion is achieved through the expressions for the streaming-induced drag...

  9. 2nd International Symposium on Shipboard Acoustics

    CERN Document Server

    1986-01-01

    The first International Symposium on Shipboard Acoustics, held in Noordwijkerhout (The Netherlands) in 1976, was a meeting of invited experts, each having considerable expertise in ship acoustics. Many of the participants were dealing with research on various ship acoustical subjects, and it proved to be a good idea to discuss future investigations and new techniques. At that time acousticians learned to use real-time signal-processing techniques and attempts were made to establish sound level prediction methods based on semi-fundamental considerations instead of the methods using empirically obtained data. Time was pressing as it was assumed that, in view of the adoption of Recommendation 141 of the International Labour Conference in 1970, authorities would soon make appropriate provisions to "protect seafarers from the ill effects of noise". This resulted in several national recommendations followed by the IMO "Code on noise levels aboard ships" which was adopted by the IMO Assembly in 1981. After that, pre...

  10. Rapid prototyping and parametric optimization of plastic acoustofluidic devices for blood-bacteria separation.

    Science.gov (United States)

    Silva, R; Dow, P; Dubay, R; Lissandrello, C; Holder, J; Densmore, D; Fiering, J

    2017-09-01

    Acoustic manipulation has emerged as a versatile method for microfluidic separation and concentration of particles and cells. Most recent demonstrations of the technology use piezoelectric actuators to excite resonant modes in silicon or glass microchannels. Here, we focus on acoustic manipulation in disposable, plastic microchannels in order to enable a low-cost processing tool for point-of-care diagnostics. Unfortunately, the performance of resonant acoustofluidic devices in plastic is hampered by a lack of a predictive model. In this paper, we build and test a plastic blood-bacteria separation device informed by a design of experiments approach, parametric rapid prototyping, and screening by image-processing. We demonstrate that the new device geometry can separate bacteria from blood while operating at 275% greater flow rate as well as reduce the power requirement by 82%, while maintaining equivalent separation performance and resolution when compared to the previously published plastic acoustofluidic separation device.

  11. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... Back Learn more about ANA About ANA Mission, Vision & Values Shop ANA Leadership & Staff Annual Reports Acoustic ... 205-8211 info@ANAUSA.org About ANA Mission, Vision & Values Leadership & Staff Annual Reports Shop ANA Home ...

  12. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... Provider List Member Portal Back Webinar Library Newsletter Library ... About Back Learn more about ANA About ANA Mission, Vision & Values Shop ANA Leadership & Staff Annual Reports Acoustic Neuroma Association 600 Peachtree ...

  13. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... a patient kit Treatment Options Overview Observation Radiation Surgery What is acoustic neuroma Diagnosing Symptoms Side effects ... To Ask Treatment Options Back Overview Observation Radiation Surgery Choosing a healthcare provider Request a patient kit ...

  14. Diagnosing Acoustic Neuroma

    Science.gov (United States)

    ... Values Leadership & Staff Annual Reports Shop ANA Home Learn Diagnosing English English Arabic Catalan Chinese (Simplified) Chinese (Traditional) Danish French German Greek Haitian Creole Hebrew Hindi Italian Japanese Korean Portuguese Romanian Spanish Diagnosing The diagnosis of an acoustic ...

  15. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... Click to learn more... LOGIN CALENDAR DONATE NEWS Home Learn Back Learn about acoustic neuroma AN Facts ... Vision & Values Leadership & Staff Annual Reports Shop ANA Home Learn Educational Video Ronson and Kerri Albany Support ...

  16. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... Click to learn more... LOGIN CALENDAR DONATE NEWS Home Learn Back Learn about acoustic neuroma AN Facts ... Vision & Values Leadership & Staff Annual Reports Shop ANA Home Learn Educational Video Howard of NJ Gloria hiking ...

  17. 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...

  18. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... Choosing a healthcare provider Request a patient kit Treatment Options Overview Observation Radiation Surgery What is acoustic neuroma Diagnosing Symptoms Side effects Question To Ask Treatment Options Back Overview Observation Radiation Surgery Choosing a ...

  19. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... Mission, Vision & Values Shop ANA Leadership & Staff Annual Reports Acoustic Neuroma Association 600 Peachtree Parkway Suite 108 ... About ANA Mission, Vision & Values Leadership & Staff Annual Reports Shop ANA Home Learn Educational Video English English ...

  20. Acoustic imaging system

    Science.gov (United States)

    Smith, Richard W.

    1979-01-01

    An acoustic imaging system for displaying an object viewed by a moving array of transducers as the array is pivoted about a fixed point within a given plane. A plurality of transducers are fixedly positioned and equally spaced within a laterally extending array and operatively directed to transmit and receive acoustic signals along substantially parallel transmission paths. The transducers are sequentially activated along the array to transmit and receive acoustic signals according to a preestablished sequence. Means are provided for generating output voltages for each reception of an acoustic signal, corresponding to the coordinate position of the object viewed as the array is pivoted. Receptions from each of the transducers are presented on the same display at coordinates corresponding to the actual position of the object viewed to form a plane view of the object scanned.

  1. Acoustics Noise Test Cell

    Data.gov (United States)

    Federal Laboratory Consortium — The Acoustic Noise Test Cell at the NASA/Caltech Jet Propulsion Laboratory (JPL) is located adjacent to the large vibration system; both are located in a class 10K...

  2. 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...

  3. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... ANA About ANA Mission, Vision & Values Shop ANA Leadership & Staff Annual Reports Acoustic Neuroma Association 600 Peachtree ... info@ANAUSA.org About ANA Mission, Vision & Values Leadership & Staff Annual Reports Shop ANA Home Learn Educational ...

  4. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... Learn more about ANA About ANA Mission, Vision & Values Shop ANA Leadership & Staff Annual Reports Acoustic Neuroma ... 8211 info@ANAUSA.org About ANA Mission, Vision & Values Leadership & Staff Annual Reports Shop ANA Home Learn ...

  5. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... Educational Video Scott at the Grand Canyon Proton Center load more hold SHIFT key to load all load all Stay Connected with ANA Newly Diagnosed Living with AN Healthcare Providers Acoustic Neuroma Association Donate Now Newly Diagnosed ...

  6. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... Click to learn more... LOGIN CALENDAR DONATE NEWS Home Learn Back Learn about acoustic neuroma AN Facts ... Vision & Values Leadership & Staff Annual Reports Shop ANA Home Learn Educational Video English English Arabic Catalan Chinese ( ...

  7. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... Click to learn more... LOGIN CALENDAR DONATE NEWS Home Learn Back Learn about acoustic neuroma AN Facts ... Vision & Values Leadership & Staff Annual Reports Shop ANA Home Learn Educational Video Keck Medicine of USC ANWarriors ...

  8. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... Suite 108 Cumming, GA 30041 770-205-8211 info@ANAUSA.org The world's #1 acoustic neuroma resource ... List Member Portal Webinar Library Newsletter Library Patient Info Booklets Member Login Research ANA Survey/Registry AN ...

  9. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... Click to learn more... LOGIN EVENTS DONATE NEWS Home Learn Back Learn about acoustic neuroma AN Facts ... Vision & Values Leadership & Staff Annual Reports Shop ANA Home Learn Educational Video Scott at the Grand Canyon ...

  10. 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...

  11. Acoustic ambient noise recorder

    Digital Repository Service at National Institute of Oceanography (India)

    Saran, A.K.; Navelkar, G.S.; Almeida, A.M.; More, S.R.; Chodankar, P.V.; Murty, C.S.

    with a robust outfit that can withstand high pressures and chemically corrosion resistant materials. Keeping these considerations in view, a CMOS micro-controller-based marine acoustic ambient noise recorder has been developed with a real time clock...

  12. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... Request a patient kit Treatment Options Overview Observation Radiation Surgery What is acoustic neuroma Diagnosing Symptoms Side ... Question To Ask Treatment Options Back Overview Observation Radiation Surgery Choosing a healthcare provider Request a patient ...

  13. 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...

  14. Acoustic MIMO signal processing

    CERN Document Server

    Huang, Yiteng; Chen, Jingdong

    2006-01-01

    A timely and important book addressing a variety of acoustic signal processing problems under multiple-input multiple-output (MIMO) scenarios. It uniquely investigates these problems within a unified framework offering a novel and penetrating analysis.

  15. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... provider Request a patient kit Treatment Options Overview Observation Radiation Surgery What is acoustic neuroma Diagnosing Symptoms ... effects Question To Ask Treatment Options Back Overview Observation Radiation Surgery Choosing a healthcare provider Request a ...

  16. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... Vision & Values Leadership & Staff Annual Reports Shop ANA ... AN Healthcare Providers Acoustic Neuroma Association Donate Now Newly Diagnosed What is AN? Request a Patient Kit Treatment Options Get Support Find a Provider Discussion Forum Contact ANA Join ...

  17. Excavation Equipment Recognition Based on Novel Acoustic Statistical Features.

    Science.gov (United States)

    Cao, Jiuwen; Wang, Wei; Wang, Jianzhong; Wang, Ruirong

    2017-12-01

    Excavation equipment recognition attracts increasing attentions in recent years due to its significance in underground pipeline network protection and civil construction management. In this paper, a novel classification algorithm based on acoustics processing is proposed for four representative excavation equipments. New acoustic statistical features, namely, the short frame energy ratio, concentration of spectrum amplitude ratio, truncated energy range, and interval of pulse are first developed to characterize acoustic signals. Then, probability density distributions of these acoustic features are analyzed and a novel classifier is presented. Experiments on real recorded acoustics of the four excavation devices are conducted to demonstrate the effectiveness of the proposed algorithm. Comparisons with two popular machine learning methods, support vector machine and extreme learning machine, combined with the popular linear prediction cepstral coefficients are provided to show the generalization capability of our method. A real surveillance system using our algorithm is developed and installed in a metro construction site for real-time recognition performance validation.

  18. 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....

  19. Deep Water Ocean Acoustics

    Science.gov (United States)

    2016-12-22

    Final Report 3. DATES COVERED (From - To) 7/1/15 to 12/22/16 4. TITLE AND SUBTITLE Deep Water Ocean Acoustics 5a. CONTRACT NUMBER...shortening of the water column); 2.) Explicitly defined the geo-acoustics so that both models had the same sponge ; 3.) Output the complete computational...chosen because this VLA was spaced at /2 at 250Hz and is therefore beamforming capable, covering the conjugate depth. An ambient noise model was

  20. Test of single degree of freedom acoustic treatment impedance models for multimodal acoustic propagation in duct with flow.

    Science.gov (United States)

    Baccouche, Ryan; Moreau, Soléne; Ben Tahar, Mabrouk

    2017-06-01

    Passive acoustic treatments, also called liners, are the main solution to noise problems. The Single Degree Of Freedom (SDOF) acoustic treatment, composed of a thin material (perforated plate) affixed to air cavities with a rigid bottom, constitutes a solution. Predicting sound level reduction by an SDOF treatment requires reliable acoustic impedance models. An experimental/numerical method has been developed for a duct with an acoustic treatment to test acoustic impedance models of SDOF treatment with a multimodal propagation in the presence of a mean flow. This method is based on the comparison of experimental results from an aeroacoustic bench composed of a circular duct with a treated area, and numerical results from an FEM-PML axisymmetric model based on Galbrun's equation. The numerical results are confronted with experimental results to test impedance models up to M0=±0.25.

  1. Flight of the bumble bee: Buzzes predict pollination services.

    Directory of Open Access Journals (Sweden)

    Nicole E Miller-Struttmann

    Full Text Available Multiple interacting factors drive recent declines in wild and managed bees, threatening their pollination services. Widespread and intensive monitoring could lead to more effective management of wild and managed bees. However, tracking their dynamic populations is costly. We tested the effectiveness of an inexpensive, noninvasive and passive acoustic survey technique for monitoring bumble bee behavior and pollination services. First, we assessed the relationship between the first harmonic of the flight buzz (characteristic frequency and pollinator functional traits that influence pollination success using flight cage experiments and a literature search. We analyzed passive acoustic survey data from three locations on Pennsylvania Mountain, Colorado to estimate bumble bee activity. We developed an algorithm based on Computational Auditory Scene Analysis that identified and quantified the number of buzzes recorded in each location. We then compared visual and acoustic estimates of bumble bee activity. Using pollinator exclusion experiments, we tested the power of buzz density to predict pollination services at the landscape scale for two bumble bee pollinated alpine forbs (Trifolium dasyphyllum and T. parryi. We found that the characteristic frequency was correlated with traits known to affect pollination efficacy, explaining 30-52% of variation in body size and tongue length. Buzz density was highly correlated with visual estimates of bumble bee density (r = 0.97, indicating that acoustic signals are predictive of bumble bee activity. Buzz density predicted seed set in two alpine forbs when bumble bees were permitted access to the flowers, but not when they were excluded from visiting. Our results indicate that acoustic signatures of flight can be deciphered to monitor bee activity and pollination services to bumble bee pollinated plants. We propose that applications of this technique could assist scientists and farmers in rapidly detecting and

  2. Flight of the bumble bee: Buzzes predict pollination services.

    Science.gov (United States)

    Miller-Struttmann, Nicole E; Heise, David; Schul, Johannes; Geib, Jennifer C; Galen, Candace

    2017-01-01

    Multiple interacting factors drive recent declines in wild and managed bees, threatening their pollination services. Widespread and intensive monitoring could lead to more effective management of wild and managed bees. However, tracking their dynamic populations is costly. We tested the effectiveness of an inexpensive, noninvasive and passive acoustic survey technique for monitoring bumble bee behavior and pollination services. First, we assessed the relationship between the first harmonic of the flight buzz (characteristic frequency) and pollinator functional traits that influence pollination success using flight cage experiments and a literature search. We analyzed passive acoustic survey data from three locations on Pennsylvania Mountain, Colorado to estimate bumble bee activity. We developed an algorithm based on Computational Auditory Scene Analysis that identified and quantified the number of buzzes recorded in each location. We then compared visual and acoustic estimates of bumble bee activity. Using pollinator exclusion experiments, we tested the power of buzz density to predict pollination services at the landscape scale for two bumble bee pollinated alpine forbs (Trifolium dasyphyllum and T. parryi). We found that the characteristic frequency was correlated with traits known to affect pollination efficacy, explaining 30-52% of variation in body size and tongue length. Buzz density was highly correlated with visual estimates of bumble bee density (r = 0.97), indicating that acoustic signals are predictive of bumble bee activity. Buzz density predicted seed set in two alpine forbs when bumble bees were permitted access to the flowers, but not when they were excluded from visiting. Our results indicate that acoustic signatures of flight can be deciphered to monitor bee activity and pollination services to bumble bee pollinated plants. We propose that applications of this technique could assist scientists and farmers in rapidly detecting and responding to bee

  3. Measuring acoustic habitats.

    Science.gov (United States)

    Merchant, Nathan D; Fristrup, Kurt M; Johnson, Mark P; Tyack, Peter L; Witt, Matthew J; Blondel, Philippe; Parks, Susan E

    2015-03-01

    1. Many organisms depend on sound for communication, predator/prey detection and navigation. The acoustic environment can therefore play an important role in ecosystem dynamics and evolution. A growing number of studies are documenting acoustic habitats and their influences on animal development, behaviour, physiology and spatial ecology, which has led to increasing demand for passive acoustic monitoring (PAM) expertise in the life sciences. However, as yet, there has been no synthesis of data processing methods for acoustic habitat monitoring, which presents an unnecessary obstacle to would-be PAM analysts. 2. Here, we review the signal processing techniques needed to produce calibrated measurements of terrestrial and aquatic acoustic habitats. We include a supplemental tutorial and template computer codes in matlab and r, which give detailed guidance on how to produce calibrated spectrograms and statistical analyses of sound levels. Key metrics and terminology for the characterisation of biotic, abiotic and anthropogenic sound are covered, and their application to relevant monitoring scenarios is illustrated through example data sets. To inform study design and hardware selection, we also include an up-to-date overview of terrestrial and aquatic PAM instruments. 3. Monitoring of acoustic habitats at large spatiotemporal scales is becoming possible through recent advances in PAM technology. This will enhance our understanding of the role of sound in the spatial ecology of acoustically sensitive species and inform spatial planning to mitigate the rising influence of anthropogenic noise in these ecosystems. As we demonstrate in this work, progress in these areas will depend upon the application of consistent and appropriate PAM methodologies.

  4. Satellite Applications to Acoustic Prediction Systems.

    Science.gov (United States)

    1982-10-01

    surface- temperatura anomaly can be studied. At the top of the thermoclina, the gradient appears strong between stations 13 and 16 (isotherms are densely...surface temperatura and mixed layer depth varied linearly with position up to station three. Sea surface temperature correlation with position along the...Technical memorandum NESS 109, 1 a avign 38. Fett and Bohan, gp. 2., p. 18-14. 39. RC4 Corporation , jjjgro-Op Handbook, pp. 83-83, 19 4. 40. FePt and Bohan

  5. Interactions in an acoustic world

    CERN Document Server

    Simaciu, Ion; Borsos, Zoltan; Bradac, Mariana

    2016-01-01

    The present paper aims to complete an earlier paper where the acoustic world was introduced. This is accomplished by analyzing the interactions which occur between the inhomogeneities of the acoustic medium, which are induced by the acoustic vibrations traveling in the medium. When a wave packet travels in a medium, the medium becomes inhomogeneous. The spherical wave packet behaves like an acoustic spherical lens for the acoustic plane waves. According to the principle of causality, there is an interaction between the wave and plane wave packet. In specific conditions the wave packet behaves as an acoustic black hole.

  6. Particle manipulation by a non-resonant acoustic levitator

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Marco A. B., E-mail: marcobrizzotti@gmail.com [Institute of Physics, University of São Paulo, CP 66318, 05314-970 São Paulo (Brazil); Pérez, Nicolás [Centro Universitario de Paysandú, Universidad de la República, Ruta 3 km 363, 60000 Paysandú (Uruguay); Adamowski, Julio C. [Department of Mechatronics and Mechanical Systems Engineering, Escola Politécnica, University of São Paulo, Av. Mello Moraes, 2231, 05508-030 São Paulo (Brazil)

    2015-01-05

    We present the analysis of a non-resonant acoustic levitator, formed by an ultrasonic transducer and a concave reflector. In contrast to traditional levitators, the geometry presented herein does not require the separation distance between the transducer and the reflector to be a multiple of half wavelength. The levitator behavior is numerically predicted by applying a numerical model to calculate the acoustic pressure distribution and the Gor'kov theory to obtain the potential of the acoustic radiation force that acts on a levitated particle. We also demonstrate that levitating particles can be manipulated by controlling the reflector position while maintaining the transducer in a fixed position.

  7. During Rapid Weight Loss in Obese Children, Reductions in TSH Predict Improvements in Insulin Sensitivity Independent of Changes in Body Weight or Fat

    NARCIS (Netherlands)

    Aeberli, I.; Jung, A.; Murer, S.B.; Wildhaber, J.; Wildhaber-Brooks, J.; Knopfli, B.H.; Zimmermann, M.B.

    2010-01-01

    Background: Although serum TSH is often elevated in obesity and may be linked to disorders of lipid and glucose metabolism, the clinical relevance of these relationships remains unclear. Subjects: Subjects were obese children and adolescents (n = 206; mean age 14 yr) undergoing rapid weight and fat

  8. Acoustic field distribution of sawtooth wave with nonlinear SBE model

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xiaozhou, E-mail: xzliu@nju.edu.cn; Zhang, Lue; Wang, Xiangda; Gong, Xiufen [Key Laboratory of Modern Acoustics, Ministry of Education, Institute of Acoustics, Nanjing University, Nanjing 210093 (China)

    2015-10-28

    For precise prediction of the acoustic field distribution of extracorporeal shock wave lithotripsy with an ellipsoid transducer, the nonlinear spheroidal beam equations (SBE) are employed to model acoustic wave propagation in medium. To solve the SBE model with frequency domain algorithm, boundary conditions are obtained for monochromatic and sawtooth waves based on the phase compensation. In numerical analysis, the influence of sinusoidal wave and sawtooth wave on axial pressure distributions are investigated.

  9. [Acoustic characteristics of classrooms].

    Science.gov (United States)

    Koszarny, Zbigniew; Chyla, Andrzej

    2003-01-01

    Quality and usefulness of school rooms for transmission of verbal information depends on the two basic parameters: form and quantity of the reverberation time, and profitable line measurements of school rooms from the acoustic point of view. An analysis of the above-mentioned parameters in 48 class rooms and two gymnasiums in schools, which were built in different periods, shows that the most important problem is connected with too long reverberation time and inappropriate acoustic proportions. In schools built in the 1970s, the length of reverberation time is mostly within a low frequency band, while in schools built contemporarily, the maximum length of disappearance time takes place in a quite wide band of 250-2000 Hz. This exceeds optimal values for that kind of rooms at least twice, and five times in the newly built school. A long reverberation time is connected with a low acoustic absorption of school rooms. Moreover, school rooms are characterised by inappropriate acoustic proportions. The classrooms, in their relation to the height, are too long and too wide. It is connected with deterioration of the transmission of verbal information. The data show that this transmission is unequal. Automatically, it leads to a speech disturbance and difficulties with understanding. There is the need for adaptation of school rooms through increase of an acoustic absorption.

  10. A study of methods to predict and measure the transmission of sound through the walls of light aircraft. Integration of certain singular boundary element integrals for applications in linear acoustics

    Science.gov (United States)

    Zimmerle, D.; Bernhard, R. J.

    1985-01-01

    An alternative method for performing singular boundary element integrals for applications in linear acoustics is discussed. The method separates the integral of the characteristic solution into a singular and nonsingular part. The singular portion is integrated with a combination of analytic and numerical techniques while the nonsingular portion is integrated with standard Gaussian quadrature. The method may be generalized to many types of subparametric elements. The integrals over elements containing the root node are considered, and the characteristic solution for linear acoustic problems are examined. The method may be generalized to most characteristic solutions.

  11. Acoustic approximations of elastic media with fast variations

    Science.gov (United States)

    Cance, P.; Capdeville, Y.

    2013-12-01

    Imaging the Earth using seismic waveforms is an intensive computational problem. Reducing numerical cost of the forward problem is therefore an important objective. At the exploration seismic imaging scale, a common practical method relies on using only P-waves information. In such case, an acoustic approximation of the elastic forward problem is often used, which reduces drastically the numerical cost, not only because the problem is smaller but mainly because the expense of correctly sampling slow S-waves is not present anymore. If this approximation is valid for slowly varying isotropic media, this is not the case in general. The present work focuses on acoustic approaches of heterogeneous elastic media with heterogeneity sizes much smaller than the propagating wavelength as well as acoustic anisotropy. A useful tool to study those rapidly varying heterogeneous media is the non periodic homogenization for waves (Capdeville et al. 2009;2010). This homogenization procedure has been adapted and applied to acoustic media. While upscaling the elastic wave equation induces elastic apparent anisotropy, we show that in the acoustic case, it is the density that becomes anisotropic. Unfortunately the induced anisotropy is not of the same nature between elastic cases and acoustic cases (in the acoustic case it proves to remain only an elliptic anisotropy) which prevent to use acoustic anisotropy to mimic elastic anisotropy. If building the acoustic media from the elastic one is obvious for slowly varying isotropic media, it is not the case anymore for rapidly varying media nor for anisotropic media. To check if these difficulties can be overcome and if at least P-waves first arrivals can be correctly reproduced we propose here two methods for building the acoustic media from the elastic one. We will refer to the first method as the 'physical method' as it tends to keep track of the physical parameters of the original medium, and to the second method as the 'mathematical

  12. Sea Turtle Acoustic Telemetry Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Acoustic transmitters attached to sea turtles captured in various fishing gear enable the animals to be passively tracked. Acoustic receivers set up in an array...

  13. 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....

  14. 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...

  15. Etiologic predictive value of a rapid immunoassay for the detection of group A Streptococcus antigen from throat swabs in patients presenting with a sore throat

    Directory of Open Access Journals (Sweden)

    Ulrich Orda

    2016-04-01

    Conclusion: This study demonstrates that the point-of-care test Alere Test Pack +Plus Strep A has a high positive predictive value and is able to rule in GAS infection as long as the proportion of carriers is low. Also the negative predictive value for ruling out GAS as the etiologic agent is very high irrespective of the carrier rate. Hence, this test is always useful to rule out GAS infection.

  16. 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.

  17. Seamount acoustic scattering

    Science.gov (United States)

    Boehlert, George W.

    The cover of the March 1 issue of Eos showed a time series of acoustic scattering above Southeast Hancock Seamount (29°48‧N, 178°05‧E) on July 17-18, 1984. In a comment on that cover Martin Hovland (Eos, August 2, p. 760) argued that gas or “other far reaching causes” may be involved in the observed acoustic signals. He favors a hypothesis that acoustic scattering observed above a seeping pockmark in the North Sea is a combination of bubbles, stable microbubbles, and pelagic organisms and infers that this may be a more general phenomenon and indeed plays a role in the attraction of organisms to seamounts

  18. 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...

  19. Ultrasonic acoustic levitation for fast frame rate X-ray protein crystallography at room temperature

    National Research Council Canada - National Science Library

    Tsujino, Soichiro; Tomizaki, Takashi

    2016-01-01

    ... of biomolecules and structure-based drug developments. Using lysozyme model crystals, we demonstrated the rapid acquisition of X-ray diffraction datasets by combining a high frame rate pixel array detector with ultrasonic acoustic levitation of protein...

  20. Acoustic Liners for Turbine Engines

    Science.gov (United States)

    Jones, Michael G (Inventor); Grady, Joseph E (Inventor); Kiser, James D. (Inventor); Miller, Christopher (Inventor); Heidmann, James D. (Inventor)

    2016-01-01

    An improved acoustic liner for turbine engines is disclosed. The acoustic liner may include a straight cell section including a plurality of cells with straight chambers. The acoustic liner may also include a bent cell section including one or more cells that are bent to extend chamber length without increasing the overall height of the acoustic liner by the entire chamber length. In some cases, holes are placed between cell chambers in addition to bending the cells, or instead of bending the cells.

  1. Good acoustics central to recovery.

    Science.gov (United States)

    Budd, Richard

    2009-04-01

    Good acoustic conditions in hospitals and other healthcare facilities are known not only to benefit patients by creating an environment that facilitates rest, sleeping, consultation and treatment, but also clinical and nursing staff. At the recent Healthcare Estates conference, Richard Budd of acoustic engineering and noise and vibration consultants Sound Research Laboratories, discussed the revised guidance on good acoustic design in a recently published Health Technical Memorandum, HTM 08-01-Acoustics.

  2. Predicting outdoor sound

    CERN Document Server

    Attenborough, Keith; Horoshenkov, Kirill

    2014-01-01

    1. Introduction  2. The Propagation of Sound Near Ground Surfaces in a Homogeneous Medium  3. Predicting the Acoustical Properties of Outdoor Ground Surfaces  4. Measurements of the Acoustical Properties of Ground Surfaces and Comparisons with Models  5. Predicting Effects of Source Characteristics on Outdoor Sound  6. Predictions, Approximations and Empirical Results for Ground Effect Excluding Meteorological Effects  7. Influence of Source Motion on Ground Effect and Diffraction  8. Predicting Effects of Mixed Impedance Ground  9. Predicting the Performance of Outdoor Noise Barriers  10. Predicting Effects of Vegetation, Trees and Turbulence  11. Analytical Approximations including Ground Effect, Refraction and Turbulence  12. Prediction Schemes  13. Predicting Sound in an Urban Environment.

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

    Science.gov (United States)

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

    2009-01-01

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

  4. 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...

  5. Terahertz Acoustics in Hot Dense Laser Plasmas

    Science.gov (United States)

    Adak, Amitava; Robinson, A. P. L.; Singh, Prashant Kumar; Chatterjee, Gourab; Lad, Amit D.; Pasley, John; Kumar, G. Ravindra

    2015-03-01

    We present a hitherto unobserved facet of hydrodynamics, namely the generation of an ultrahigh frequency acoustic disturbance in the terahertz frequency range, whose origins are purely hydrodynamic in nature. The disturbance is caused by differential flow velocities down a density gradient in a plasma created by a 30 fs, 800 nm high-intensity laser (˜5 ×1016 W /cm2 ). The picosecond scale observations enable us to capture these high frequency oscillations (1.9 ±0.6 THz ) which are generated as a consequence of the rapid heating of the medium by the laser. Adoption of two complementary techniques, namely pump-probe reflectometry and pump-probe Doppler spectrometry provides unambiguous identification of this terahertz acoustic disturbance. Hydrodynamic simulations well reproduce the observations, offering insight into this process.

  6. A Novel 7-Single Nucleotide Polymorphism-Based Clonotyping Test Allows Rapid Prediction of Antimicrobial Susceptibility of Extraintestinal Escherichia coli Directly From Urine Specimens

    OpenAIRE

    Tchesnokova, Veronika; Avagyan, Hovhannes; Billig, Mariya; Chattopadhyay, Sujay; Aprikian, Pavel; Chan, Diana; Pseunova, Julietta; Rechkina, Elena; Riddell, Kim; Scholes, Delia; Fang, Ferric C.; Johnson, James R.; Sokurenko, Evgeni V.

    2016-01-01

    Background. ?Escherichia coli is a highly clonal pathogen. Extraintestinal isolates belong to a limited number of genetically related groups, which often exhibit characteristic antimicrobial resistance profiles. Methods. ?We developed a rapid clonotyping method for extraintestinal E coli based on detection of the presence or absence of 7 single nucleotide polymorphisms (SNPs) within 2 genes (fumC and fimH). A reference set of 2559 E coli isolates, primarily of urinary origin, was used to pred...

  7. Carbon Nanotube Underwater Acoustic Thermophone

    Science.gov (United States)

    2016-09-23

    material (such as a piezoelectric ceramic , piezocomposite, or a magnetostrictive ferromagnetic compound). This electrical excitation creates a...Traditional acoustic transduction typically begins with the generation of electrical excitation pulsed through an amplifier into an electro-acoustic...mechanical vibration that is then converted into an acoustic wave to produce sound. The lower the preferred transmitting frequency (and hence a longer

  8. 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.

  9. Fundamentals of Acoustics. Psychoacoustics and Hearing. Acoustical Measurements

    Science.gov (United States)

    Begault, Durand R.; Ahumada, Al (Technical Monitor)

    1997-01-01

    These are 3 chapters that will appear in a book titled "Building Acoustical Design", edited by Charles Salter. They are designed to introduce the reader to fundamental concepts of acoustics, particularly as they relate to the built environment. "Fundamentals of Acoustics" reviews basic concepts of sound waveform frequency, pressure, and phase. "Psychoacoustics and Hearing" discusses the human interpretation sound pressure as loudness, particularly as a function of frequency. "Acoustic Measurements" gives a simple overview of the time and frequency weightings for sound pressure measurements that are used in acoustical work.

  10. Positive amplitude electron acoustic solitary waves in auroral plasma

    Science.gov (United States)

    Ghosh, S. S.; Lakhina, G. S.

    Rapidly moving positive potential pulses have been observed by FAST and POLAR satellites in downward current region of auroral plasma. They are characterized by their high velocities (> 1000 km/s) which are of the order of the electron drift velocities and are found to be associated with electron beams. Interestingly, it is observed that the width of such electron mode solitary waves increases with the amplitude [Ergun et al. (1998)]. Theoretically, they are interpreted as BGK electron phase space holes. However, Berthomier et al. (2000) have shown that a positive amplitude solitary wave may well exist for an electron acoustic mode. According to a weakly nonlinear theory, the width of such an electron acoustic solitary wave is expected to decrease with increasing amplitude which contradicts the observation. On the other hand, in our previous work, we have shown that the width of a large amplitude rarefactive ion acoustic solitary wave increases with an increasing amplitude [Ghosh et al. (2004)]. In the present work, we have extended our analysis to an electron acoustic solitary wave. A fully nonlinear solution of positive amplitude electron acoustic solitary waves (electron acoustic solitary holes) has been obtained by adopting the Sagdeev pseudopotetial technique. The plasma is assumed to be magnetized and traversed by the electron beam. The existence domain of such electron acoustic solitary holes is studied in detail. It is found that the width of electron acoustic solitary holes increases with increasing amplitude. Theoretically estimated width-amplitude variation profiles have been compared with recent satellite observations. It is proposed that a model based on electron acoustic mode may well interpret the fast moving solitary holes for an appropriate parameter space. References:Berthomier et al., Phys. Plasma, 7, 2987 (2000).Ergun et al., Phys. Rev. Lett., 81, 826, (1998).Ghosh and Lakhina,, Nonlin. Process. Geophys, (2004), (to be appeared).

  11. Material Property Measurement in Hostile Environments using Laser Acoustics

    Energy Technology Data Exchange (ETDEWEB)

    Ken L. Telschow

    2004-08-01

    Acoustic methods are well known and have been used to measure various intrinsic material properties, such as, elastic coefficients, density, crystal axis orientation, microstructural texture, and residual stress. Extrinsic properties, such as, dimensions, motion variables or temperature are also readily determined from acoustic methods. Laser acoustics, employing optical generation and detection of elastic waves, has a unique advantage over other acoustic methods—it is noncontacting, uses the sample surface itself for transduction, requires no couplant or invasive sample surface preparation and can be utilized in any hostile environment allowing optical access to the sample surface. In addition, optical generation and detection probe beams can be focused to the micron scale and/or shaped to alter the transduction process with a degree of control not possible using contact transduction methods. Laser methods are amenable to both continuous wave and pulse-echo measurements and have been used from Hz to 100’s of GHz (time scales from sec to psec) and with amplitudes sufficient to fracture materials. This paper shall review recent applications of laser acoustic methods to determining material properties in hostile environments that preclude the use of contacting transduction techniques. Example environments include high temperature (>1000C) sintering and molten metal processing, thin film deposition by plasma techniques, materials moving at high velocity during the fabrication process and nuclear high radiation regions. Recent technological advances in solid-state lasers and telecommunications have greatly aided the development and implementation of laser acoustic methods, particularly at ultra high frequencies. Consequently, laser acoustic material property measurements exhibit high precision and reproducibility today. In addition, optical techniques provide methods of imaging acoustic motion that is both quantitative and rapid. Possible future directions for

  12. Acoustic solitons: A robust tool to investigate the generation and detection of ultrafast acoustic waves

    Science.gov (United States)

    Péronne, Emmanuel; Chuecos, Nicolas; Thevenard, Laura; Perrin, Bernard

    2017-02-01

    Solitons are self-preserving traveling waves of great interest in nonlinear physics but hard to observe experimentally. In this report an experimental setup is designed to observe and characterize acoustic solitons in a GaAs(001) substrate. It is based on careful temperature control of the sample and an interferometric detection scheme. Ultrashort acoustic solitons, such as the one predicted by the Korteweg-de Vries equation, are observed and fully characterized. Their particlelike nature is clearly evidenced and their unique properties are thoroughly checked. The spatial averaging of the soliton wave front is shown to account for the differences between the theoretical and experimental soliton profile. It appears that ultrafast acoustic experiments provide a precise measurement of the soliton velocity. It allows for absolute calibration of the setup as well as the response function analysis of the detection layer. Moreover, the temporal distribution of the solitons is also analyzed with the help of the inverse scattering method. It shows how the initial acoustic pulse profile which gives birth to solitons after nonlinear propagation can be retrieved. Such investigations provide a new tool to probe transient properties of highly excited matter through the study of the emitted acoustic pulse after laser excitation.

  13. Mesh-type acoustic vector sensor

    Science.gov (United States)

    Zalalutdinov, M. K.; Photiadis, D. M.; Szymczak, W. G.; McMahon, J. W.; Bucaro, J. A.; Houston, B. H.

    2017-07-01

    Motivated by the predictions of a theoretical model developed to describe the acoustic flow force exerted on closely spaced nano-fibers in a viscous medium, we have demonstrated a novel concept for a particle velocity-based directional acoustic sensor. The central element of the concept exploits the acoustically induced normal displacement of a fine mesh as a measure of the collinear projection of the particle velocity in the sound wave. The key observations are (i) the acoustically induced flow force on an individual fiber within the mesh is nearly independent of the fiber diameter and (ii) the mesh-flow interaction can be well-described theoretically by a nearest neighbor coupling approximation. Scaling arguments based on these two observations indicate that the refinement of the mesh down to the nanoscale leads to significant improvements in performance. The combination of the two dimensional nature of the mesh together with the nanoscale dimensions provides a dramatic gain in the total length of fiber exposed to the flow, leading to a sensitivity enhancement by orders of magnitude. We describe the fabrication of a prototype mesh sensor equipped with optical readout. Preliminary measurements carried out over a considerable bandwidth together with the results of numerical simulations are in good agreement with the theory, thus providing a proof of concept.

  14. Acoustic properties of reticulated plastic foams

    Science.gov (United States)

    Cummings, A.; Beadle, S. P.

    1994-08-01

    Some general aspects of sound propagation in rigid porous media are discussed, particularly with reference to the use of a single - dimensionless - frequency parameter and the role of this, in the light of the possibility of varying gas properties, is examined. Steady flow resistance coefficients of porous media are also considered, and simple scaling relationships between these coefficients and `system parameters' are derived. The results of a series of measurements of the bulk acoustic properties of 12 geometrically similar, fully reticulated, polyurethane foams are presented, and empirical curve-fitting coefficients are found; the curve-fitting formulae are valid within the experimental range of values of the frequency parameter. Comparison is made between the measured data and an alternative, fairly recently published, semi-empirical set of formulae. Measurements of the steady flow-resistive coefficients are also given and both the acoustical and flow-resistive data are shown to be consistent with theoretical ideas. The acoustical and flow-resistive data should be of use in predicting the acoustic bulk properties of open-celled foams of types similar to those used in the experimental tests.

  15. Broadband acoustic properties of a murine skull

    Science.gov (United States)

    Estrada, Héctor; Rebling, Johannes; Turner, Jake; Razansky, Daniel

    2016-03-01

    It has been well recognized that the presence of a skull imposes harsh restrictions on the use of ultrasound and optoacoustic techniques in the study, treatment and modulation of the brain function. We propose a rigorous modeling and experimental methodology for estimating the insertion loss and the elastic constants of the skull over a wide range of frequencies and incidence angles. A point-source-like excitation of ultrawideband acoustic radiation was induced via the absorption of nanosecond duration laser pulses by a 20 μm diameter microsphere. The acoustic waves transmitted through the skull are recorded by a broadband, spherically focused ultrasound transducer. A coregistered pulse-echo ultrasound scan is subsequently performed to provide accurate skull geometry to be fed into an acoustic transmission model represented in an angular spectrum domain. The modeling predictions were validated by measurements taken from a glass cover-slip and ex vivo adult mouse skulls. The flexible semi-analytical formulation of the model allows for seamless extension to other transducer geometries and diverse experimental scenarios involving broadband acoustic transmission through locally flat solid structures. It is anticipated that accurate quantification and modeling of the skull transmission effects would ultimately allow for skull aberration correction in a broad variety of applications employing transcranial detection or transmission of high frequency ultrasound.

  16. Ultrathin Acoustic Metasurface-Based Schroeder Diffuser

    Directory of Open Access Journals (Sweden)

    Yifan Zhu

    2017-06-01

    Full Text Available “Schroeder diffuser” is a classical design, proposed over 40 years ago, for artificially creating optimal and predictable sound diffuse reflection. It has been widely adopted in architectural acoustics, and it has also shown substantial potential in noise control, ultrasound imaging, microparticle manipulation et al. The conventional Schroeder diffuser, however, has a considerable thickness on the order of one wavelength, severely impeding its applications for low-frequency sound. In this paper, a new class of ultrathin and planar Schroeder diffusers are proposed based on the concept of an acoustic metasurface. Both numerical and experimental results demonstrate satisfactory sound diffuse reflection produced from the metasurface-based Schroeder diffuser despite it being approximately 1 order of magnitude thinner than the conventional one. The proposed design not only offers promising building blocks with great potential to profoundly impact architectural acoustics and related fields, but it also constitutes a major step towards real-world applications of acoustic metasurfaces.

  17. Intra-and-Inter Species Biomass Prediction in a Plantation Forest: Testing the Utility of High Spatial Resolution Spaceborne Multispectral RapidEye Sensor and Advanced Machine Learning Algorithms

    Directory of Open Access Journals (Sweden)

    Timothy Dube

    2014-08-01

    Full Text Available The quantification of aboveground biomass using remote sensing is critical for better understanding the role of forests in carbon sequestration and for informed sustainable management. Although remote sensing techniques have been proven useful in assessing forest biomass in general, more is required to investigate their capabilities in predicting intra-and-inter species biomass which are mainly characterised by non-linear relationships. In this study, we tested two machine learning algorithms, Stochastic Gradient Boosting (SGB and Random Forest (RF regression trees to predict intra-and-inter species biomass using high resolution RapidEye reflectance bands as well as the derived vegetation indices in a commercial plantation. The results showed that the SGB algorithm yielded the best performance for intra-and-inter species biomass prediction; using all the predictor variables as well as based on the most important selected variables. For example using the most important variables the algorithm produced an R2 of 0.80 and RMSE of 16.93 t·ha−1 for E. grandis; R2 of 0.79, RMSE of 17.27 t·ha−1 for P. taeda and R2 of 0.61, RMSE of 43.39 t·ha−1 for the combined species data sets. Comparatively, RF yielded plausible results only for E. dunii (R2 of 0.79; RMSE of 7.18 t·ha−1. We demonstrated that although the two statistical methods were able to predict biomass accurately, RF produced weaker results as compared to SGB when applied to combined species dataset. The result underscores the relevance of stochastic models in predicting biomass drawn from different species and genera using the new generation high resolution RapidEye sensor with strategically positioned bands.

  18. 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...

  19. 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.

  20. Intelligent Engine Systems: Acoustics

    Science.gov (United States)

    Wojno, John; Martens, Steve; Simpson, Benjamin

    2008-01-01

    An extensive study of new fan exhaust nozzle technologies was performed. Three new uniform chevron nozzles were designed, based on extensive CFD analysis. Two new azimuthally varying variants were defined. All five were tested, along with two existing nozzles, on a representative model-scale, medium BPR exhaust nozzle. Substantial acoustic benefits were obtained from the uniform chevron nozzle designs, the best benefit being provided by an existing design. However, one of the azimuthally varying nozzle designs exhibited even better performance than any of the uniform chevron nozzles. In addition to the fan chevron nozzles, a new technology was demonstrated, using devices that enhance mixing when applied to an exhaust nozzle. The acoustic benefits from these devices applied to medium BPR nozzles were similar, and in some cases superior to, those obtained from conventional uniform chevron nozzles. However, none of the low noise technologies provided equivalent acoustic benefits on a model-scale high BPR exhaust nozzle, similar to current large commercial applications. New technologies must be identified to improve the acoustics of state-of-the-art high BPR jet engines.

  1. Deep Water Ocean Acoustics

    Science.gov (United States)

    2015-07-17

    Society of America 125 (4), 1394-1402 (2008). 2 J.W. Goodman , Introduction to Fourier Optics . (Roberts & Company, 2005). 3 George L Pickard and William...3 1. Introduction ...Report No. QSR-14C0172-Ocean Acoustics-063015 Technical Progress Report 1. Introduction The goal of this research is to increase our understanding

  2. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... Surgery What is acoustic neuroma Diagnosing Symptoms Side effects ... Groups Is a support group for me? Find a Group Upcoming Events Video Library Photo Gallery One-on-One Support ANetwork Peer Support Program Community Connections Overview Find a Meeting ...

  3. Select Internet Resources on Acoustics

    Directory of Open Access Journals (Sweden)

    Angela R. Davis

    2016-12-01

    Full Text Available Merriam-Webster (2016 defines acoustics as, “a science that deals with the production, control, transmission, reception, and effects of sounds.” According to Rossing (2014, the study of acoustics began in ancient Greece with Pythagoras’ study of vibrating strings on musical instruments. Since those early beginnings, famous scientists including Rayleigh, Alexander Graham Bell, and Thomas Edison, have helped expand the field of acoustics to include architectural, physical, engineering, structural, underwater, physiological and psychological, musical acoustics, and speech. Acoustics is a highly interdisciplinary field and researchers may need resources from physics, medicine, and engineering to understand all aspects of their research.

  4. Research activities on vibro-acoustics of satellites during rocket launch

    OpenAIRE

    Murakami, Keiichi; Inada, Yoshinobu; Aoyama, Takashi; Takahashi, Takashi; Aiso, Hideaki; 村上 桂一; 稲田 喜信; 青山 剛史; 高橋 孝; 相曽 秀昭

    2006-01-01

    A study to establish a prediction method for vibro-acoustics of satellites during rocket launch has been conducted using a multidisciplinary analysis method of fluid, acoustic, and vibration. This coupling method consists of following four elements: numerical analyses of (1) sound generation, (2) sound propagation, (3) sound permeation, and (4) vibro-acoustics of payload. In the sound generation analysis, it can be seen from FEM analysis of a simply modeled deflector that a strong resonance o...

  5. Mapping reef fish and the seascape: using acoustics and spatial modeling to guide coastal management.

    Science.gov (United States)

    Costa, Bryan; Taylor, J Christopher; Kracker, Laura; Battista, Tim; Pittman, Simon

    2014-01-01

    Reef fish distributions are patchy in time and space with some coral reef habitats supporting higher densities (i.e., aggregations) of fish than others. Identifying and quantifying fish aggregations (particularly during spawning events) are often top priorities for coastal managers. However, the rapid mapping of these aggregations using conventional survey methods (e.g., non-technical SCUBA diving and remotely operated cameras) are limited by depth, visibility and time. Acoustic sensors (i.e., splitbeam and multibeam echosounders) are not constrained by these same limitations, and were used to concurrently map and quantify the location, density and size of reef fish along with seafloor structure in two, separate locations in the U.S. Virgin Islands. Reef fish aggregations were documented along the shelf edge, an ecologically important ecotone in the region. Fish were grouped into three classes according to body size, and relationships with the benthic seascape were modeled in one area using Boosted Regression Trees. These models were validated in a second area to test their predictive performance in locations where fish have not been mapped. Models predicting the density of large fish (≥ 29 cm) performed well (i.e., AUC = 0.77). Water depth and standard deviation of depth were the most influential predictors at two spatial scales (100 and 300 m). Models of small (≤ 11 cm) and medium (12-28 cm) fish performed poorly (i.e., AUC = 0.49 to 0.68) due to the high prevalence (45-79%) of smaller fish in both locations, and the unequal prevalence of smaller fish in the training and validation areas. Integrating acoustic sensors with spatial modeling offers a new and reliable approach to rapidly identify fish aggregations and to predict the density large fish in un-surveyed locations. This integrative approach will help coastal managers to prioritize sites, and focus their limited resources on areas that may be of higher conservation value.

  6. Acoustic field modulation in regenerators

    Science.gov (United States)

    Hu, J. Y.; Wang, W.; Luo, E. C.; Chen, Y. Y.

    2016-12-01

    The regenerator is a key component that transfers energy between heat and work. The conversion efficiency is significantly influenced by the acoustic field in the regenerator. Much effort has been spent to quantitatively determine this influence, but few comprehensive experimental verifications have been performed because of difficulties in modulating and measuring the acoustic field. In this paper, a method requiring two compressors is introduced and theoretically investigated that achieves acoustic field modulation in the regenerator. One compressor outputs the acoustic power for the regenerator; the other acts as a phase shifter. A RC load dissipates the acoustic power out of both the regenerator and the latter compressor. The acoustic field can be modulated by adjusting the current in the two compressors and opening the RC load. The acoustic field is measured with pressure sensors instead of flow-field imaging equipment, thereby greatly simplifying the experiment.

  7. Controlling sound with acoustic metamaterials

    DEFF Research Database (Denmark)

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

    2016-01-01

    -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......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...

  8. Combination of acoustical radiosity and the image source method

    DEFF Research Database (Denmark)

    Koutsouris, Georgios I; Brunskog, Jonas; Jeong, Cheol-Ho

    2013-01-01

    A combined model for room acoustic predictions is developed, aiming to treat both diffuse and specular reflections in a unified way. Two established methods are incorporated: acoustical radiosity, accounting for the diffuse part, and the image source method, accounting for the specular part....... The model is based on conservation of acoustical energy. Losses are taken into account by the energy absorption coefficient, and the diffuse reflections are controlled via the scattering coefficient, which defines the portion of energy that has been diffusely reflected. The way the model is formulated...... allows for a dynamic control of the image source production, so that no fixed maximum reflection order is required. The model is optimized for energy impulse response predictions in arbitrary polyhedral rooms. The predictions are validated by comparison with published measured data for a real music...

  9. Imaging acoustic sources moving at high-speed

    Science.gov (United States)

    Bodony, Daniel; Papanicolaou, George

    2006-11-01

    In the quantification of the noise radiated by a turbulent flow the source motion is important. It is well known that moving acoustic sources radiate sound preferrentially in the direction of motion in a phenomenon termed `convective amplification.' Modern acoustic theories have utilized this behavior in their predictions. In the inverse problem the imaging of noise sources, by techniques such as beam forming, the source motion is not explicitly taken into account. In this talk we consider the imaging of acoustic sources moving at speeds on the order of the the ambient speed of sound, as typical of high-speed jets, for which the D"oppler shift approximation is not appropriate. An analysis will be presented that can be used to estimate the source motion based on the radiated acoustic field.

  10. Vibro-acoustic modeling and analysis of a coupled acoustic system comprising a partially opened cavity coupled with a flexible plate

    Science.gov (United States)

    Shi, Shuangxia; Su, Zhu; Jin, Guoyong; Liu, Zhigang

    2018-01-01

    This paper is concerned with the modeling and solution method of a three-dimensional (3D) coupled acoustic system comprising a partially opened cavity coupled with a flexible plate and an exterior field of semi-infinite size, which is ubiquitously encountered in architectural acoustics and is a reasonable representation of many engineering occasions. A general solution method is presented to predict the dynamic behaviors of the three-dimensional (3D) acoustic coupled system, in which the displacement of the plate and the sound pressure in the cavity are respectively constructed in the form of the two-dimensional and three-dimensional modified Fourier series with several auxiliary functions introduced to ensure the uniform convergence of the solution over the entire solution domain. The effect of the opening is taken into account via the work done by the sound pressure acting at the coupling aperture that is contributed from the vibration of particles on the acoustic coupling interface and on the structural-acoustic coupling interface. Both the acoustic coupling between finite cavity and exterior field and the structural-acoustic coupling between flexible plate and interior acoustic field are considered in the vibro-acoustic modeling of the three-dimensional acoustic coupled acoustic system. The dynamic responses of the coupled structural-acoustic system are obtained using the Rayleigh-Ritz procedure based on the energy expressions for the coupled system. The accuracy and effectiveness of the proposed method are validated through numerical examples and comparison with results obtained by the boundary element analysis. Furthermore, the influence of the opening and the cavity volume on the acoustic behaviors of opened cavity system is studied.

  11. Displacements prediction from 3D finite element model of maxillary protraction with and without rapid maxillary expansion in a patient with unilateral cleft palate and alveolus.

    Science.gov (United States)

    Zhang, Dan; Zheng, Li; Wang, Qiang; Lu, Li; Ma, Jia

    2015-08-19

    Both maxillary protraction and rapid expansion are recommended for patients with cleft palate and alveolus. The aim of the study is to establish a three-dimensional finite element model of the craniomaxillary complex with unilateral cleft palate and alveolus to simulate maxillary protraction with and without rapid maxillary expansion. The study also investigates the deformation of the craniomaxillary complex after applied orthopaedic forces in different directions. A three dimensional finite element model of 1,277,568 hexahedral elements (C3D8) and 1,801,945 nodes was established based upon CT scan of a patient with unilateral cleft palate and alveolus on the right side in this study. A force of 4.9 N per side was directed on the anatomic height of contour on the buccal side of the first molar. The angles between the force vector and occlusal plane were -30°, -20°, -10°, 0°, 10°, 20°, and 30°. A force of 2.45 N on each loading point was directed on the anatomic height of contour on the lingual side of the first premolar and the first molar to simulate the expansion of the palate. The craniomaxillary complex displaced forward under any of the loading conditions. The sagittal and vertical displacement of the craniomaxillary complex reached their peak at the protraction degree of -10° forward and downward to the occlusal plane. There were larger sagittal displacements when the maxilla was protracted forward with maxillary expansion. The palatal plane rotated counterclockwise under any of the loading conditions. Being protracted without expansion, the dental arch was constricted. When supplemented with maxillary expansion, the width of the dental arch increased. Transverse deformation of the dental arch on affected side was different from that on unaffected side. Protraction force alone led the craniomaxillary complex moved forward and counterclockwise, accompanied with lateral constrain on the dental arch. Additional rapid maxillary expansion resulted in a

  12. Acoustic and elastic multiple scattering and radiation from cylindrical structures

    Science.gov (United States)

    Amirkulova, Feruza Abdukadirovna

    Multiple scattering (MS) and radiation of waves by a system of scatterers is of great theoretical and practical importance and is required in a wide variety of physical contexts such as the implementation of "invisibility" cloaks, the effective parameter characterization, and the fabrication of dynamically tunable structures, etc. The dissertation develops fast, rapidly convergent iterative techniques to expedite the solution of MS problems. The formulation of MS problems reduces to a system of linear algebraic equations using Graf's theorem and separation of variables. The iterative techniques are developed using Neumann expansion and Block Toeplitz structure of the linear system; they are very general, and suitable for parallel computations and a large number of MS problems, i.e. acoustic, elastic, electromagnetic, etc., and used for the first time to solve MS problems. The theory is implemented in Matlab and FORTRAN, and the theoretical predictions are compared to computations obtained by COMSOL. To formulate the MS problem, the transition matrix is obtained by analyzing an acoustic and an elastic single scattering of incident waves by elastic isotropic and anisotropic solids. The mathematical model of wave scattering from multilayered cylindrical and spherical structures is developed by means of an exact solution of dynamic 3D elasticity theory. The recursive impedance matrix algorithm is derived for radially heterogeneous anisotropic solids. An explicit method for finding the impedance in piecewise uniform, transverse-isotropic material is proposed; the solution is compared to elasticity theory solutions involving Buchwald potentials. Furthermore, active exterior cloaking devices are modeled for acoustic and elastic media using multipole sources. A cloaking device can render an object invisible to some incident waves as seen by some external observer. The active cloak is generated by a discrete set of multipole sources that destructively interfere with an

  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. A brief review of dispensing-based rapid prototyping techniques in tissue scaffold fabrication: role of modeling on scaffold properties prediction.

    Science.gov (United States)

    Li, M G; Tian, X Y; Chen, X B

    2009-09-01

    Artificial scaffolds play vital roles in tissue engineering as they provide a supportive environment for cell attachment, proliferation and differentiation during tissue formation. Fabrication of tissue scaffolds is thus of fundamental importance for tissue engineering. Of the variety of scaffold fabrication techniques available, rapid prototyping (RP) methods have attracted a great deal of attention in recent years. This method can improve conventional scaffold fabrication by controlling scaffold microstructure, incorporating cells into scaffolds and regulating cell distribution. All of these contribute towards the ultimate goal of tissue engineering: functional tissues or organs. Dispensing is typically used in different RP techniques to implement the layer-by-layer fabrication process. This article reviews RP methods in tissue scaffold fabrication, with emphasis on dispensing-based techniques, and analyzes the effects of different process factors on fabrication performance, including flow rate, pore size and porosity, and mechanical cell damage that can occur in the bio-manufacturing process.

  15. A brief review of dispensing-based rapid prototyping techniques in tissue scaffold fabrication: role of modeling on scaffold properties prediction

    Energy Technology Data Exchange (ETDEWEB)

    Li, M G; Chen, X B [Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5A9 (Canada); Tian, X Y, E-mail: mil715@mail.usask.c [Division of Biomedical Engineering, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5A9 (Canada)

    2009-09-15

    Artificial scaffolds play vital roles in tissue engineering as they provide a supportive environment for cell attachment, proliferation and differentiation during tissue formation. Fabrication of tissue scaffolds is thus of fundamental importance for tissue engineering. Of the variety of scaffold fabrication techniques available, rapid prototyping (RP) methods have attracted a great deal of attention in recent years. This method can improve conventional scaffold fabrication by controlling scaffold microstructure, incorporating cells into scaffolds and regulating cell distribution. All of these contribute towards the ultimate goal of tissue engineering: functional tissues or organs. Dispensing is typically used in different RP techniques to implement the layer-by-layer fabrication process. This article reviews RP methods in tissue scaffold fabrication, with emphasis on dispensing-based techniques, and analyzes the effects of different process factors on fabrication performance, including flow rate, pore size and porosity, and mechanical cell damage that can occur in the bio-manufacturing process. (topical review)

  16. Acoustic levitation of an object larger than the acoustic wavelength.

    Science.gov (United States)

    Andrade, Marco A B; Okina, Fábio T A; Bernassau, Anne L; Adamowski, Julio C

    2017-06-01

    Levitation and manipulation of objects by sound waves have a wide range of applications in chemistry, biology, material sciences, and engineering. However, the current acoustic levitation techniques are mainly restricted to particles that are much smaller than the acoustic wavelength. In this work, it is shown that acoustic standing waves can be employed to stably levitate an object much larger than the acoustic wavelength in air. The levitation of a large slightly curved object weighting 2.3 g is demonstrated by using a device formed by two 25 kHz ultrasonic Langevin transducers connected to an aluminum plate. The sound wave emitted by the device provides a vertical acoustic radiation force to counteract gravity and a lateral restoring force that ensure horizontal stability to the levitated object. In order to understand the levitation stability, a numerical model based on the finite element method is used to determine the acoustic radiation force that acts on the object.

  17. Underwater acoustic signatures of glacier calving

    Science.gov (United States)

    Glowacki, O.; Deane, G. B.; Moskalik, M.; Blondel, Ph.; Tegowski, J.; Blaszczyk, M.

    2015-02-01

    Climate-driven ice-water interactions in the contact zone between marine-terminating glaciers and the ocean surface show a dynamic and complex nature. Tidewater glaciers lose volume through the poorly understood process of calving. A detailed description of the mechanisms controlling the course of calving is essential for the reliable estimation and prediction of mass loss from glaciers. Here we present the potential of hydroacoustic methods to investigate different modes of ice detachments. High-frequency underwater ambient noise recordings are combined with synchronized, high-resolution, time-lapse photography of the Hans Glacier cliff in Hornsund Fjord, Spitsbergen, to identify three types of calving events: typical subaerial, sliding subaerial, and submarine. A quantitative analysis of the data reveals a robust correlation between ice impact energy and acoustic emission at frequencies below 200 Hz for subaerial calving. We suggest that relatively inexpensive acoustic methods can be successfully used to provide quantitative descriptions of the various calving types.

  18. Ice breakup: Observations of the acoustic signal

    Science.gov (United States)

    Waddell, S. R.; Farmer, D. M.

    1988-03-01

    We describe observations of ambient sound beneath landfast ice in the Canadian Arctic Archipelago and interpret its evolution over the period June-August in terms of ice cracking and disintegration. The data were recorded on six bands between 50 and 14,500 Hz for the period April 2 to August 7, 1986, in Dolphin and Union Strait. The frequency dependence of the attenuation of sound in water allows separation of distant and local noise sources. In conjunction with satellite imagery and meteorological data, it is shown that strong signals in the acoustic time series are associated with major breakup events. The acoustic signal can provide predictive information about ice conditions and the approach of breakup.

  19. Acoustic Rapid COTS Insertion: A Case Study in Spiral Development

    National Research Council Canada - National Science Library

    Boudreau, Michael

    2006-01-01

    ...) beginning with towed-array sonar on 688 Class Submarines and later encompassing all sonar systems on all attack submarines, some surface ship sonar applications, and even aviation anti-submarine warfare...

  20. Acoustic rhinometry in children undergoing a rapid maxillary expansion

    OpenAIRE

    Mario Cappellette Jr.; Daniela Carlini; Shirley Shizue Nagata Pignatari; Oswaldo Laércio Mendonça Cruz; Luc Louis Maurice Weckx

    2006-01-01

    OBJETIVO: este estudo foi realizado na Disciplina de Otorrinolaringologia Pediátrica da Escola Paulista de Medicina - UNIFESP, com o objetivo de verificar o comportamento da disjunção maxilar e sua influência na cavidade nasal em crianças de 7 a 8 anos de idade submetidas à rinometria acústica. METODOLOGIA: foram avaliadas 20 crianças respiradoras bucais, portadoras de atresia maxilar diagnosticada clinicamente e submetidas à avaliação objetiva da cavidade nasal pré-disjunção maxilar e pós-di...

  1. Deriving content-specific measures of room acoustic perception using a binaural, nonlinear auditory model

    NARCIS (Netherlands)

    Van Dorp Schuitman, J.; De Vries, D.; Lindau, A.

    2013-01-01

    Acousticians generally assess the acoustic qualities of a concert hall or any other room using impulse response-based measures such as the reverberation time, clarity index, and others. These parameters are used to predict perceptual attributes related to the acoustic qualities of the room. Various

  2. Comparison of two acoustic analogies applied to experimental PIV data for cavity sound emission estimation

    NARCIS (Netherlands)

    Koschatzky, V.; Westerweel, J.; Boersma, B.J.

    2010-01-01

    The aim of the present study is to compare two different acoustic analogies applied to time-resolved particle image velocimetry (PIV) data for the prediction of the acoustic far-field generated by the flow over a rectangular cavity. Recent developments in laser and camera technology allow the

  3. Simulation of an Underwater Acoustic Communication Channel Characterized by Wind-Generated Surface Waves and Bubbles

    NARCIS (Netherlands)

    Dol, H.S.; Ainslie, M.A.; Colin, M.E.G.D.; Janmaat, J.

    2012-01-01

    Sea surface scattering by wind-generated waves and bubbles is regarded to be the main nonplatform-related cause of the time variability of shallow acoustic communication channels. Simulations for predicting the quality of acoustic communication links in such channels thus require adequate modelling

  4. Biodiversity sampling using a global acoustic approach: contrasting sites with microendemics in New Caledonia.

    Directory of Open Access Journals (Sweden)

    Amandine Gasc

    Full Text Available New Caledonia is a Pacific island with a unique biodiversity showing an extreme microendemism. Many species distributions observed on this island are extremely restricted, localized to mountains or rivers making biodiversity evaluation and conservation a difficult task. A rapid biodiversity assessment method based on acoustics was recently proposed. This method could help to document the unique spatial structure observed in New Caledonia. Here, this method was applied in an attempt to reveal differences among three mountain sites (Mandjélia, Koghis and Aoupinié with similar ecological features and species richness level, but with high beta diversity according to different microendemic assemblages. In each site, several local acoustic communities were sampled with audio recorders. An automatic acoustic sampling was run on these three sites for a period of 82 successive days. Acoustic properties of animal communities were analysed without any species identification. A frequency spectral complexity index (NP was used as an estimate of the level of acoustic activity and a frequency spectral dissimilarity index (Df assessed acoustic differences between pairs of recordings. As expected, the index NP did not reveal significant differences in the acoustic activity level between the three sites. However, the acoustic variability estimated by the index Df , could first be explained by changes in the acoustic communities along the 24-hour cycle and second by acoustic dissimilarities between the three sites. The results support the hypothesis that global acoustic analyses can detect acoustic differences between sites with similar species richness and similar ecological context, but with different species assemblages. This study also demonstrates that global acoustic methods applied at broad spatial and temporal scales could help to assess local biodiversity in the challenging context of microendemism. The method could be deployed over large areas, and

  5. Biodiversity sampling using a global acoustic approach: contrasting sites with microendemics in New Caledonia.

    Science.gov (United States)

    Gasc, Amandine; Sueur, Jérôme; Pavoine, Sandrine; Pellens, Roseli; Grandcolas, Philippe

    2013-01-01

    New Caledonia is a Pacific island with a unique biodiversity showing an extreme microendemism. Many species distributions observed on this island are extremely restricted, localized to mountains or rivers making biodiversity evaluation and conservation a difficult task. A rapid biodiversity assessment method based on acoustics was recently proposed. This method could help to document the unique spatial structure observed in New Caledonia. Here, this method was applied in an attempt to reveal differences among three mountain sites (Mandjélia, Koghis and Aoupinié) with similar ecological features and species richness level, but with high beta diversity according to different microendemic assemblages. In each site, several local acoustic communities were sampled with audio recorders. An automatic acoustic sampling was run on these three sites for a period of 82 successive days. Acoustic properties of animal communities were analysed without any species identification. A frequency spectral complexity index (NP) was used as an estimate of the level of acoustic activity and a frequency spectral dissimilarity index (Df ) assessed acoustic differences between pairs of recordings. As expected, the index NP did not reveal significant differences in the acoustic activity level between the three sites. However, the acoustic variability estimated by the index Df , could first be explained by changes in the acoustic communities along the 24-hour cycle and second by acoustic dissimilarities between the three sites. The results support the hypothesis that global acoustic analyses can detect acoustic differences between sites with similar species richness and similar ecological context, but with different species assemblages. This study also demonstrates that global acoustic methods applied at broad spatial and temporal scales could help to assess local biodiversity in the challenging context of microendemism. The method could be deployed over large areas, and could help to

  6. RAPID3? Aptly named!

    Science.gov (United States)

    Berthelot, J-M

    2014-01-01

    The RAPID3 score is the sum of three 0-10 patient self-report scores: pain, functional impairment on MDHAQ, and patient global estimate. It requires 5 seconds for scoring and can be used in all rheumatologic conditions, although it has mostly been used in rheumatoid arthritis where cutoffs for low disease activity (12/30) have been set. A RAPID3 score of ≤ 3/30 with 1 or 0 swollen joints (RAPID3 ≤ 3 + ≤ SJ1) provides remission criteria comparable to Boolean, SDAI, CDAI, and DAS28 remission criteria, in far less time than a formal joint count. RAPID3 performs as well as the DAS28 in separating active drugs from placebos in clinical trials. RAPID3 also predicts subsequent structural disease progression. RAPID3 can be determined at short intervals at home, allowing the determination of the area under the curve of disease activity between two visits and flare detection. However, RAPID3 should not be seen as a substitute for DAS28 and face to face visits in routine care. Monitoring patient status with only self-report information without a rheumatologist's advice (including joints and physical examination, and consideration of imaging and laboratory tests) may indeed be as undesirable for most patients than joint examination without a patient questionnaire. Conversely, combining the RAPID3 and the DAS28 may consist in faster or more sensitive confirmation that a medication is effective. Similarly, better enquiring of most important concerns of patients (pain, functional status and overall opinion on their disorder) should reinforces patients' confidence in their rheumatologist and treatments.

  7. Rapid determination of thermodynamic parameters from one-dimensional programmed-temperature gas chromatography for use in retention time prediction in comprehensive multidimensional chromatography.

    Science.gov (United States)

    McGinitie, Teague M; Ebrahimi-Najafabadi, Heshmatollah; Harynuk, James J

    2014-01-17

    A new method for estimating the thermodynamic parameters of ΔH(T0), ΔS(T0), and ΔCP for use in thermodynamic modeling of GC×GC separations has been developed. The method is an alternative to the traditional isothermal separations required to fit a three-parameter thermodynamic model to retention data. Herein, a non-linear optimization technique is used to estimate the parameters from a series of temperature-programmed separations using the Nelder-Mead simplex algorithm. With this method, the time required to obtain estimates of thermodynamic parameters a series of analytes is significantly reduced. This new method allows for precise predictions of retention time with the average error being only 0.2s for 1D separations. Predictions for GC×GC separations were also in agreement with experimental measurements; having an average relative error of 0.37% for (1)tr and 2.1% for (2)tr. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Fundamentals of Physical Acoustics

    OpenAIRE

    Leclaire, Philippe

    2001-01-01

    Book review: Fundamentals of Physical Acoustics D.T. Blackstock; Wiley & Sons Ltd, New York, 2000, 541 pages, ISBN 0-471-3197; This book is an excellent piece of work. The text is extremely clear and goes a long way towards meeting the declared pedagogical target. The author has written a comprehensive text. The proportions of equations and explanations/interpretations are particularly well balanced. Throughout the book, the context and the validity domain for any equation derived are clearly...

  9. Ion Acoustic Microscopy

    Science.gov (United States)

    1985-07-01

    Murphy and L. C. Aamodt , "Signal Enhancement in Photothermal Imaging Produced by Three Dimensional Heat Flow", Appl. Phys. Lett. 39, 519 (1981); L. C... Aamodt and J. C. Murphy, "Photothermal Measurements Using a Localized Excitation Source", J. Appl. Phys. 52, 4903 (1981) (9) R. L. Thomas, L. D. Favro...25 (23) J. C. Murphy, F. G. Satkiewicz and L. C. Aamodt , "Ion Acoustic Imaging of Buried Flaws in Aluminum", Review of Progress in Quantitative NDE

  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. Fast wideband acoustical holography.

    Science.gov (United States)

    Hald, Jørgen

    2016-04-01

    Patch near-field acoustical holography methods like statistically optimized near-field acoustical holography and equivalent source method are limited to relatively low frequencies, where the average array-element spacing is less than half of the acoustic wavelength, while beamforming provides useful resolution only at medium-to-high frequencies. With adequate array design, both methods can be used with the same array. But for holography to provide good low-frequency resolution, a small measurement distance is needed, whereas beamforming requires a larger distance to limit sidelobe issues. The wideband holography method of the present paper was developed to overcome that practical conflict. Only a single measurement is needed at a relatively short distance and a single result is obtained covering the full frequency range. The method uses the principles of compressed sensing: A sparse sound field representation is assumed with a chosen set of basis functions, a measurement is taken with an irregular array, and the inverse problem is solved with a method that enforces sparsity in the coefficient vector. Instead of using regularization based on the 1-norm of the coefficient vector, an iterative solution procedure is used that promotes sparsity. The iterative method is shown to provide very similar results in most cases and to be computationally much more efficient.

  12. Spatiotemporally resolved granular acoustics

    Science.gov (United States)

    Owens, Eli; Daniels, Karen

    2011-03-01

    Acoustic techniques provide a non-invasive method of characterizing granular material properties; however, there are many challenges in formulating accurate models of sound propagation due to the inherently heterogeneous nature of granular materials. In order to quantify acoustic responses in space and time, we perform experiments in a photoelastic granular material in which the internal stress pattern (in the form of force chains) is visible. We utilize two complementary methods, high-speed imaging and piezoelectric transduction, to provide particle-scale measurements of the amplitude of the acoustic wave. We observe that the average wave amplitude is largest within particles experiencing the largest forces. The force-dependence of this amplitude is in qualitative agreement with a simple Hertzian-like model for contact area. In addition, we investigate the power spectrum of the propagating signal using the piezoelectric sensors. For a Gaussian wave packet input, we observe a broad spectrum of transmitted frequencies below the driving frequency, and we quantify the characteristic frequencies and corresponding length scales of our material as the system pressure is varied.

  13. Application of air-coupled acoustic thermography (ACAT) for inspection of honeycomb sandwich structures

    Science.gov (United States)

    Zalameda, Joseph N.; Winfree, William P.; Pergantis, Charles G.; DeSchepper, Daniel; Flanagan, David

    2009-05-01

    The application of a noncontact air coupled acoustic heating technique is investigated for the inspection of advanced honeycomb composite structures. A weakness in the out of plane stiffness of the structure, caused by a delamination or core damage, allows for the coupling of acoustic energy and thus this area will have a higher temperature than the surrounding area. Air coupled acoustic thermography (ACAT) measurements were made on composite sandwich structures with damage and were compared to conventional flash thermography. A vibrating plate model is presented to predict the optimal acoustic source frequency. Improvements to the measurement technique are also discussed.

  14. Application of Air Coupled Acoustic Thermography (ACAT) for Inspection of Honeycomb Sandwich Structures

    Science.gov (United States)

    Winfree, William P.; Zalameda, Joseph N.; Pergantis, Charles; Flanagan, David; Deschepper, Daniel

    2009-01-01

    The application of a noncontact air coupled acoustic heating technique is investigated for the inspection of advanced honeycomb composite structures. A weakness in the out of plane stiffness of the structure, caused by a delamination or core damage, allows for the coupling of acoustic energy and thus this area will have a higher temperature than the surrounding area. Air coupled acoustic thermography (ACAT) measurements were made on composite sandwich structures with damage and were compared to conventional flash thermography. A vibrating plate model is presented to predict the optimal acoustic source frequency. Improvements to the measurement technique are also discussed.

  15. Bayesian hindcast of acoustic transmission loss in the western Pacific Ocean

    Science.gov (United States)

    Palmsten, Margaret; Paquin Fabre, J.

    2016-09-01

    A Bayesian network is developed to demonstrate the feasibility of using environmental acoustic feature vectors (EAFVs) to predict underwater acoustic transmission loss (TL) versus range at two locations for a single acoustic source depth and frequency. Features for the networks are chosen based on a sensitivity analysis. The final network design resulted in a well-trained network, with high skill, little gain error, and low bias. The capability presented here shows promise for expansion to a more generalized approach, which could be applied at varying locations, depths and frequencies to estimate acoustic performance over a highly variable oceanographic area in real-time or near-real-time.

  16. Double acoustic microresonator quartz-enhanced photoacoustic spectroscopy.

    Science.gov (United States)

    Dong, Lei; Wu, Hongpeng; Zheng, Huadan; Liu, Yanyan; Liu, Xiaoli; Jiang, Wenzhe; Zhang, Lei; Ma, Weiguang; Ren, Wei; Yin, Wangbao; Jia, Suotang; Tittel, Frank K

    2014-04-15

    Quartz-enhanced photoacoustic spectroscopy (QEPAS) based on double acoustic microresonators (AmRs) is developed and experimentally investigated. The double AmR spectrophone configuration exhibits a strong acoustic coupling between the AmR and the quartz tuning fork, which results in a ∼5  ms fast response time. Moreover, the double AmRs provide two independent detection channels that allow optical signal addition or cancellation from different optical wavelengths and facilitate rapid multigas sensing measurements, thereby avoiding laser beam combination.

  17. Phonological Awareness and Rapid Automatized Naming Predicting Early Development in Reading and Spelling: Results from a Cross-Linguistic Longitudinal Study

    Science.gov (United States)

    Furnes, Bjarte; Samuelsson, Stefan

    2010-01-01

    In this study, the relationship between latent constructs of phonological awareness (PA) and rapid automatized naming (RAN) were investigated and related to later measures of reading and spelling in children learning to read in different alphabetic writing systems (i.e., Norwegian/Swedish vs. English). 750 U.S./Australian children and 230 Scandinavian children were followed longitudinally between kindergarten and 2nd grade. PA and RAN were measured in kindergarten and Grade 1, while word recognition, phonological decoding, and spelling were measured in kindergarten, Grade 1, and Grade 2. In general, high stability was observed for the various reading and spelling measures, such that little additional variance was left open for PA and RAN. However, results demonstrated that RAN was more related to reading than spelling across orthographies, with the opposite pattern shown for PA. In addition, tests of measurement invariance show that the factor loadings of each observed indicator on the latent PA factor was the same across U.S./Australia and Scandinavia. Similar findings were obtained for RAN. In general, tests of structural invariance show that models of early literacy development are highly transferable across languages. PMID:21359098

  18. Phonological Awareness and Rapid Automatized Naming Predicting Early Development in Reading and Spelling: Results from a Cross-Linguistic Longitudinal Study.

    Science.gov (United States)

    Furnes, Bjarte; Samuelsson, Stefan

    2011-02-01

    In this study, the relationship between latent constructs of phonological awareness (PA) and rapid automatized naming (RAN) were investigated and related to later measures of reading and spelling in children learning to read in different alphabetic writing systems (i.e., Norwegian/Swedish vs. English). 750 U.S./Australian children and 230 Scandinavian children were followed longitudinally between kindergarten and 2nd grade. PA and RAN were measured in kindergarten and Grade 1, while word recognition, phonological decoding, and spelling were measured in kindergarten, Grade 1, and Grade 2. In general, high stability was observed for the various reading and spelling measures, such that little additional variance was left open for PA and RAN. However, results demonstrated that RAN was more related to reading than spelling across orthographies, with the opposite pattern shown for PA. In addition, tests of measurement invariance show that the factor loadings of each observed indicator on the latent PA factor was the same across U.S./Australia and Scandinavia. Similar findings were obtained for RAN. In general, tests of structural invariance show that models of early literacy development are highly transferable across languages.

  19. Monitoring caries risks before the window of infection and later caries increment: a caries prediction study on rapid detection of Streptococcus mutans using monoclonal antibodies.

    Science.gov (United States)

    Maki, Yoshinobu; Sakayori, Takaharu; Hirata, SoIchiro; Ishii, Takuo; Tachino, Atsushi

    2014-01-01

    A new semi-quantitative enumeration system has been developed for the detection of Streptococcus mutans in saliva. Using two kinds of species-specific monoclonal antibodies, this system can quickly detect salivary S. mutans within 30 min and classify the results into three levels. The aim of this study was to evaluate the potential of this test kit in determining risk for the development of caries. Saliva samples collected during a compulsory dental examination from 56 children aged 18-months were tested. The children were classified into 3 groups according to the level of salivary S. mutans determined. After 18 months, 36 of the children underwent a second examination to investigate whether there was a correlation between salivary S. mutans level at the first examination and subsequent increment in caries. The results showed a good correlation between the two. This indicates that salivary S. mutans level before the window of infection is an indicator of caries risk and can be quickly detected using this test kit. This rapid test should be particularly useful in assessing risk of future caries in very young children.

  20. 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.

  1. 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.

  2. 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.

  3. Propellant injection strategy for suppressing acoustic combustion instability

    Science.gov (United States)

    Diao, Qina

    Shear-coaxial injector elements are often used in liquid-propellant-rocket thrust chambers, where combustion instabilities remain a significant problem. A conventional solution to the combustion instability problem relies on passive control techniques that use empirically-developed hardware such as acoustic baffles and tuned cavities. In addition to adding weight and decreasing engine performance, these devices are designed using trial-and-error methods, which do not provide the capability to predict the overall system stability characteristics in advance. In this thesis, two novel control strategies that are based on propellant fluid dynamics were investigated for mitigating acoustic instability involving shear-coaxial injector elements. The new control strategies would use a set of controlled injectors allowing local adjustment of propellant flow patterns for each operating condition, particularly when instability could become a problem. One strategy relies on reducing the oxidizer-fuel density gradient by blending heavier methane with the main fuel, hydrogen. Another strategy utilizes modifying the equivalence ratio to affect the acoustic impedance through mixing and reaction rate changes. The potential effectiveness of these strategies was assessed by conducting unit-physics experiments. Two different model combustors, one simulating a single-element injector test and the other a double-element injector test, were designed and tested for flame-acoustic interaction. For these experiments, the Reynolds number of the central oxygen jet was kept between 4700 and 5500 making the injector flames sufficiently turbulent. A compression driver, mounted on one side of the combustor wall, provided controlled acoustic excitation to the injector flames, simulating the initial phase of flame-acoustic interaction. Acoustic excitation was applied either as band-limited white noise forcing between 100 Hz and 5000 Hz or as single-frequency, fixed-amplitude forcing at 1150 Hz

  4. Effect of rapid maxillary expansion on the dimension of the nasal cavity and on facial morphology assessed by acoustic rhinometry and rhinomanometry Efeito da expansão rápida da maxila na dimensão da cavidade nasal e morfologia facial pela rinometria acústica e rinomanometria

    Directory of Open Access Journals (Sweden)

    Carla Enoki Itikawa

    2012-08-01

    Full Text Available OBJECTIVE: To assess the effects of rapid maxillary expansion on facial morphology and on nasal cavity dimensions of mouth breathing children by acoustic rhinometry and computed rhinomanometry. METHODS: Cohort; 29 mouth breathing children with posterior crossbite were evaluated. Orthodontic and otorhinolaryngologic documentation were performed at three different times, i.e., before expansion, immediately after and 90 days following expansion. RESULTS: The expansion was accompanied by an increase of the maxillary and nasal bone transversal width. However, there were no significant differences in relation to mucosal area of the nose. Acoustic rhinometry showed no difference in the minimal cross-sectional area at the level of the valve and inferior turbinate between the periods analyzed, although rhinomanometry showed a statistically significant reduction in nasal resistance right after expansion, but were similar to pre-treatment values 90 days after expansion. CONCLUSION: The maxillary expansion increased the maxilla and nasal bony area, but was inefficient to increase the nasal mucosal area, and may lessen the nasal resistance, although there was no difference in nasal geometry. Significance: Nasal bony expansion is followed by a mucosal compensation.OBJETIVO: avaliar o efeito da expansão rápida da maxila na dimensão da cavidade nasal e na morfologia facial através da rinometria acústica e rinomanometria computadorizada. MÉTODOS: foram avaliadas 29 crianças na fase de dentição mista, portadoras de respiração bucal e mordida cruzada posterior. A documentação ortodôntica e a avaliação otorrinolaringológica foram realizadas em três tempos - antes da expansão rápida da maxila, imediatamente após e 90 dias depois. RESULTADOS: a expansão promoveu um aumento na dimensão da cavidade nasal e na maxila transversalmente. Contudo, não houve diferenças significativas na área da mucosa nasal. A rinometria acústica mostrou que n

  5. Shallow-Water Mud Acoustics

    Science.gov (United States)

    2015-09-30

    1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Shallow-Water Mud Acoustics William L. Siegmann...models and methods that explain observed material and acoustic properties of different physical types of shallow-ocean mud sediments. Other goals...are to assess prior data relating to the acoustic properties of mud and to provide guidance in the development and interpretation of experiments. A

  6. Experimental verification of theoretical equations for acoustic radiation force on compressible spherical particles in traveling waves

    Science.gov (United States)

    Johnson, Kennita A.; Vormohr, Hannah R.; Doinikov, Alexander A.; Bouakaz, Ayache; Shields, C. Wyatt; López, Gabriel P.; Dayton, Paul A.

    2016-05-01

    Acoustophoresis uses acoustic radiation force to remotely manipulate particles suspended in a host fluid for many scientific, technological, and medical applications, such as acoustic levitation, acoustic coagulation, contrast ultrasound imaging, ultrasound-assisted drug delivery, etc. To estimate the magnitude of acoustic radiation forces, equations derived for an inviscid host fluid are commonly used. However, there are theoretical predictions that, in the case of a traveling wave, viscous effects can dramatically change the magnitude of acoustic radiation forces, which make the equations obtained for an inviscid host fluid invalid for proper estimation of acoustic radiation forces. To date, experimental verification of these predictions has not been published. Experimental measurements of viscous effects on acoustic radiation forces in a traveling wave were conducted using a confocal optical and acoustic system and values were compared with available theories. Our results show that, even in a low-viscosity fluid such as water, the magnitude of acoustic radiation forces is increased manyfold by viscous effects in comparison with what follows from the equations derived for an inviscid fluid.

  7. Grade 3 ischemia on the admission electrocardiogram predicts rapid progression of necrosis over time and less myocardial salvage by primary angioplasty.

    Science.gov (United States)

    Billgren, Therese; Maynard, Charles; Christian, Timothy F; Rahman, Mohmmad A; Saeed, Mahammad; Hammill, Stephen C; Wagner, Galen S; Birnbaum, Yochai

    2005-07-01

    Among patients with ST-elevation acute myocardial infarction, those with terminal QRS distortion (grade 3 ischemia) have higher mortality and larger infarct size (IS) than patients without QRS distortion (grade 2 ischemia). We assessed the relation of baseline electrocardiographic ischemia grades to area at risk (AR) and myocardial salvage [100 (AR-IS)/AR] in 79 patients who underwent primary angioplasty for first ST-elevation acute myocardial infarction and had technetium Tc 99m sestamibi single-photon emission computed tomography before angioplasty (AR) and at predischarge (IS). Patients were classified as having grade 2 ischemia (ST elevation without terminal QRS distortion in any of the leads, n = 48), grade 2.5 ischemia (ST elevation with terminal QRS distortion in 1 lead, n = 16), or grade 3 ischemia (ST elevation with terminal QRS distortion in >2 adjacent leads, n = 15). Time to treatment was comparable among groups. AR was comparable among groups (38% +/- 20%, 33% +/- 23%, and 34% +/- 23%, respectively; P = .70). There were no differences among groups in residual myocardial perfusion (severity index 0.28 +/- 0.12, 0.29 +/- 0.16, and 0.30 +/- 0.15 in grades 2, 2.5, and 3 ischemia, respectively; P = .97). In contrast, there was a trend toward lower myocardial salvage (45% +/- 32%) in the grade 3 group than in the grade 2 (65% +/- 33%) and grade 2.5 (65% +/- 40%) groups ( P = .16). Salvage was dependent on time only in the grade 3 group. Spearman rank correlation coefficients between time to treatment and percentage salvage were 0.003 ( P = .99), -0.24 ( P = .38), and -0.63 ( P = .022) for grades 2, 2.5, and 3, respectively. Patients with grade 3 ischemia have rapid progression of necrosis over time and less myocardial salvage. This admission pattern is a predictor of myocardial salvage by primary angioplasty.

  8. 1-1-12 one-step wash-in scheme for desflurane-nitrous oxide low-flow anesthesia: rapid and predictable induction.

    Science.gov (United States)

    Sathitkarnmanee, Thepakorn; Tribuddharat, Sirirat; Suttinarakorn, Chakthip; Nonlhaopol, Duangthida; Thananun, Maneerat; Somdee, Wilawan; Theerapongpakdee, Sunchai

    2014-01-01

    We propose a 1-1-12 wash-in scheme for desflurane-nitrous oxide (N2O) low-flow anesthesia. The objective of our study was to determine the time to achieve alveolar concentration of desflurane (FAD) at 1, 2, 3, 4, 5, and 6%. We enrolled 106 patients scheduled for elective surgery under general anesthesia. After induction and intubation, wash-in was started with a fresh gas flow (FGF) of N2O : O2 1 : 1 L min(-1) and vaporizer concentration of desflurane (FD) of 12%. Ventilation was controlled to maintain PACO2 at 30-35 mmHg. The FAD rose rapidly from 0 to 4% in 2 min in a linear manner in 0.5 min increments. An FAD of 6% was achieved in 4 min in a linear fashion from FAD of 4% but in 1 min increments. An FAD of 1 to 6% occurred at 0.6, 1, 1.5, 2, 3, and 4 min. Heart rate during wash-in showed a statistically, albeit not clinically, significant pattern of increase. By contrast, blood pressure slightly decreased during this period. We developed a 1-1-12 wash-in scheme using a FGF of N2O : O2 1 : 1 L min(-1) and FD of 12% for desflurane-nitrous oxide low-flow anesthesia. A respective FAD of 1, 2, 3, 4, 5, and 6% can be expected at 0.6, 1, 1.5, 2, 3, and 4 min.

  9. 1-1-12 One-Step Wash-In Scheme for Desflurane-Nitrous Oxide Low-Flow Anesthesia: Rapid and Predictable Induction

    Directory of Open Access Journals (Sweden)

    Thepakorn Sathitkarnmanee

    2014-01-01

    Full Text Available Background. We propose a 1-1-12 wash-in scheme for desflurane-nitrous oxide (N2O low-flow anesthesia. The objective of our study was to determine the time to achieve alveolar concentration of desflurane (FAD at 1, 2, 3, 4, 5, and 6%. Methods. We enrolled 106 patients scheduled for elective surgery under general anesthesia. After induction and intubation, wash-in was started with a fresh gas flow (FGF of N2O : O2 1 : 1 L min−1 and vaporizer concentration of desflurane (FD of 12%. Ventilation was controlled to maintain PACO2 at 30–35 mmHg. Results. The FAD rose rapidly from 0 to 4% in 2 min in a linear manner in 0.5 min increments. An FAD of 6% was achieved in 4 min in a linear fashion from FAD of 4% but in 1 min increments. An FAD of 1 to 6% occurred at 0.6, 1, 1.5, 2, 3, and 4 min. Heart rate during wash-in showed a statistically, albeit not clinically, significant pattern of increase. By contrast, blood pressure slightly decreased during this period. Conclusions. We developed a 1-1-12 wash-in scheme using a FGF of N2O : O2 1 : 1 L min−1 and FD of 12% for desflurane-nitrous oxide low-flow anesthesia. A respective FAD of 1, 2, 3, 4, 5, and 6% can be expected at 0.6, 1, 1.5, 2, 3, and 4 min.

  10. Rapid Prototyping

    Science.gov (United States)

    1999-01-01

    Javelin, a Lone Peak Engineering Inc. Company has introduced the SteamRoller(TM) System as a commercial product. The system was designed by Javelin during a Phase II NASA funded small commercial product. The purpose of the invention was to allow automated-feed of flexible ceramic tapes to the Laminated Object Manufacturing rapid prototyping equipment. The ceramic material that Javelin was working with during the Phase II project is silicon nitride. This engineered ceramic material is of interest for space-based component.

  11. NDE Acoustic Microscopy Research Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The purpose is to develop advanced, more effective high-resolution micro-NDE materials characterization methods using scanning acoustic microscopy. The laboratory's...

  12. Acoustic Communications Measurement Systems (ACOMMS)

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Design and develop adaptive signal processing techniques to improve underwater acoustic communications and networking. Phase coherent and incoherent signal...

  13. 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...

  14. Fluid mechanical model of the acoustic impedance of small orifices

    Science.gov (United States)

    Hersh, A. S.; Rogers, T.

    1976-01-01

    A fluid mechanical model of the acoustic behavior of small orifices is presented which predicts orifice resistance and reactance as a function of incident sound pressure level, frequency, and orifice geometry. Agreement between predicted and measured values is excellent. The model shows the following: (1) The acoustic flow in immediate neighborhood of the orifice can be modeled as a locally spherical flow. Within this near field, the flow is, to a first approximation, unsteady and incompressible. (2) At very low sound pressure levels, the orifice viscous resistance is directly related to the effect of boundary-layer displacement along the walls containing the orifice, and the orifice reactance is directly related to the inertia of the oscillating flow in the neighborhood of the orifice. (3) For large values of the incident acoustic pressure, the impedance is dominated by nonlinear jet-like effects. (4) For low values of the pressure, the resistance and reactance are roughly equal.

  15. Predictive value of autoantibodies from anti-CCP2, anti-MCV and anti-human citrullinated fibrinogen tests, in early rheumatoid arthritis patients with rapid radiographic progression at 1 year: results from the ESPOIR cohort.

    Science.gov (United States)

    Degboé, Yannick; Constantin, Arnaud; Nigon, Delphine; Tobon, Gabriel; Cornillet, Martin; Schaeverbeke, Thierry; Chiocchia, Gilles; Nicaise-Roland, Pascale; Nogueira, Leonor; Serre, Guy; Cantagrel, Alain; Ruyssen-Witrand, Adeline

    2015-01-01

    We compared the ability of antibodies against cyclic citrullinated peptides (anti-CCP2), against mutated citrullinated vimentin (anti-MCV) and against citrullinated fibrinogen (AhFibA) to predict 1 year rapid radiographic progression (RRP; total Sharp score variation ≥5 points), in early rheumatoid arthritis (RA). We analysed 566 patients from the ESPOIR cohort with early RA fulfilling the 2010 American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) criteria at year 1. We assayed the 3 anticitrullinated peptide antibodies (ACPA) tests on baseline sera. We compared the performance of these 3 ACPA tests to predict first-year RRP, by comparing areas under the receiver operating characteristic curves (ROCs). We assessed the 1 year RRP risk by ACPA titres. We used a logistic multivariate regression to analyse RRP risk in terms either of ACPA positivity or titre: high (>3 times the N cut-off) and low (1 to 3N). 145 patients displayed RRP. Areas under the ROCs were similar (0.60) for the 3 tests. High ACPA titres were associated with 1 year RRP, whatever the test was, and with similar ORs. Low+ anti-MCV titres were not associated with 1-year RRP, whereas low+ anti-CCP2 titres (p=0.0226) and low+ AhFibA titres (p=0.0332) were significantly associated. In multivariate analysis, 1 year RRP was associated with anti-CCP2 positivity (p1), AhFibA positivity (p1) and high anti-MCV titres (p1). Anti-CCP2 antibodies and AhFibA were predictive of 1 year RRP in early RA whatever their titre was, whereas only high anti-MCV antibody titres were predictive, potentially making them more discriminant to predict 1 year RRP risk.

  16. Does training novices to criteria and does rapid acquisition of skills on laparoscopic simulators have predictive validity or are we just playing video games?

    Science.gov (United States)

    Hogle, Nancy J; Widmann, Warren D; Ude, Aku O; Hardy, Mark A; Fowler, Dennis L

    2008-01-01

    To determine whether LapSim training (version 3.0; Surgical Science Ltd, Göteborg, Sweden) to criteria for novice PGY1 surgical residents had predictive validity for improvement in the performance of laparoscopic cholecystectomy. In all, 21 PGY1 residents performed laparoscopic cholecystectomies in pigs after minimal training; their performance was evaluated by skilled laparoscopic surgeons using the validated tool GOALS (global operative assessment of laparoscopic operative skills: depth perception, bimanual dexterity, efficiency, tissue handling, and overall competence). From the group, 10 residents trained to competency on the LapSim Basic Skills Programs (camera navigation, instrument navigation, coordination, grasping, lifting and grasping, cutting, and clip applying). All 21 PGY1 residents again performed laparoscopic cholecystectomies on pigs; their performance was again evaluated by skilled laparoscopic surgeons using GOALS. Additionally, we studied the rate of learning to determine whether the slow or fast learners on the LapSim performed equivalently when performing actual cholecystectomies in pigs. Finally, 6 categorical residents were tracked, and their clinical performance on all of the laparoscopic cholecystectomies in which they were "surgeon, junior" was prospectively evaluated using the GOALS criteria. We found a statistical improvement of depth perception in the operative performance of cholecystectomies in pigs in the group trained on the LapSim. In the other 4 domains, a trend toward improvement was observed. No correlation between being a fast learner and the ultimate skill was demonstrated in the clinical performance of laparoscopic cholecystectomies. We did find that the fast learners on LapSim all were past or current video game players ("gamers"); however, that background did not translate into better clinical performance. Using current criteria, we doubt that the time and effort spent training novice PGY1 Surgical Residents on the basic

  17. Observation of terahertz radiation coherently generated by acoustic waves

    Science.gov (United States)

    Armstrong, Michael R.; Reed, Evan J.; Kim, Ki-Yong; Glownia, James H.; Howard, William M.; Piner, Edwin L.; Roberts, John C.

    2009-04-01

    Over the past decade, pioneering and innovative experiments using subpicosecond lasers have demonstrated the generation and detection of acoustic and shock waves in materials with terahertz frequencies, the highest possible frequency acoustic waves. In addition to groundbreaking demonstrations of acoustic solitons, these experiments have led to new techniques for probing the structure of thin films. Terahertz-frequency electromagnetic radiation has been used in applications as diverse as molecular and material excitations, charge transfer, imaging and plasma dynamics. However, at present, existing approaches to detect and measure the time dependence of terahertz-frequency strain waves in materials use direct optical probes-time-resolved interferometry or reflectrometry. Piezoelectric-based strain gauges have been used in acoustic shock and strain wave experiments for decades, but the time resolution of such devices is limited to ~100ps and slower, the timescale of electronic recording technology. We have recently predicted that terahertz-frequency acoustic waves can be detected by observing terahertz radiation emitted when the acoustic wave propagates past an interface between materials of differing piezoelectric coefficients. Here, we report the first experimental observation of this fundamentally new phenomenon and demonstrate that it can be used to probe structural properties of thin films.

  18. Quantitative Determination of Lateral Mode Dispersion in Film Bulk Acoustic Resonators through Laser Acoustic Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Ken Telschow; John D. Larson III

    2006-10-01

    Film Bulk Acoustic Resonators are useful for many signal processing applications. Detailed knowledge of their operation properties are needed to optimize their design for specific applications. The finite size of these resonators precludes their use in single acoustic modes; rather, multiple wave modes, such as, lateral wave modes are always excited concurrently. In order to determine the contributions of these modes, we have been using a newly developed full-field laser acoustic imaging approach to directly measure their amplitude and phase throughout the resonator. This paper describes new results comparing modeling of both elastic and piezoelectric effects in the active material with imaging measurement of all excited modes. Fourier transformation of the acoustic amplitude and phase displacement images provides a quantitative determination of excited mode amplitude and wavenumber at any frequency. Images combined at several frequencies form a direct visualization of lateral mode excitation and dispersion for the device under test allowing mode identification and comparison with predicted operational properties. Discussion and analysis are presented for modes near the first longitudinal thickness resonance (~900 MHz) in an AlN thin film resonator. Plate wave modeling, taking account of material crystalline orientation, elastic and piezoelectric properties and overlayer metallic films, will be discussed in relation to direct image measurements.

  19. Spacecraft Internal Acoustic Environment Modeling

    Science.gov (United States)

    Chu, SShao-sheng R.; Allen, Christopher S.

    2009-01-01

    Acoustic modeling can be used to identify key noise sources, determine/analyze sub-allocated requirements, keep track of the accumulation of minor noise sources, and to predict vehicle noise levels at various stages in vehicle development, first with estimates of noise sources, later with experimental data. In FY09, the physical mockup developed in FY08, with interior geometric shape similar to Orion CM (Crew Module) IML (Interior Mode Line), was used to validate SEA (Statistical Energy Analysis) acoustic model development with realistic ventilation fan sources. The sound power levels of these sources were unknown a priori, as opposed to previous studies that RSS (Reference Sound Source) with known sound power level was used. The modeling results were evaluated based on comparisons to measurements of sound pressure levels over a wide frequency range, including the frequency range where SEA gives good results. Sound intensity measurement was performed over a rectangular-shaped grid system enclosing the ventilation fan source. Sound intensities were measured at the top, front, back, right, and left surfaces of the and system. Sound intensity at the bottom surface was not measured, but sound blocking material was placed tinder the bottom surface to reflect most of the incident sound energy back to the remaining measured surfaces. Integrating measured sound intensities over measured surfaces renders estimated sound power of the source. The reverberation time T6o of the mockup interior had been modified to match reverberation levels of ISS US Lab interior for speech frequency bands, i.e., 0.5k, 1k, 2k, 4 kHz, by attaching appropriately sized Thinsulate sound absorption material to the interior wall of the mockup. Sound absorption of Thinsulate was modeled in three methods: Sabine equation with measured mockup interior reverberation time T60, layup model based on past impedance tube testing, and layup model plus air absorption correction. The evaluation/validation was

  20. IDEPI: rapid prediction of HIV-1 antibody epitopes and other phenotypic features from sequence data using a flexible machine learning platform.

    Directory of Open Access Journals (Sweden)

    N Lance Hepler

    2014-09-01

    Full Text Available Since its identification in 1983, HIV-1 has been the focus of a research effort unprecedented in scope and difficulty, whose ultimate goals--a cure and a vaccine--remain elusive. One of the fundamental challenges in accomplishing these goals is the tremendous genetic variability of the virus, with some genes differing at as many as 40% of nucleotide positions among circulating strains. Because of this, the genetic bases of many viral phenotypes, most notably the susceptibility to neutralization by a particular antibody, are difficult to identify computationally. Drawing upon open-source general-purpose machine learning algorithms and libraries, we have developed a software package IDEPI (IDentify EPItopes for learning genotype-to-phenotype predictive models from sequences with known phenotypes. IDEPI can apply learned models to classify sequences of unknown phenotypes, and also identify specific sequence features which contribute to a particular phenotype. We demonstrate that IDEPI achieves performance similar to or better than that of previously published approaches on four well-studied problems: finding the epitopes of broadly neutralizing antibodies (bNab, determining coreceptor tropism of the virus, identifying compartment-specific genetic signatures of the virus, and deducing drug-resistance associated mutations. The cross-platform Python source code (released under the GPL 3.0 license, documentation, issue tracking, and a pre-configured virtual machine for IDEPI can be found at https://github.com/veg/idepi.

  1. A matrix risk model for the prediction of rapid radiographic progression in patients with rheumatoid arthritis receiving different dynamic treatment strategies: post hoc analyses from the BeSt study.

    Science.gov (United States)

    Visser, K; Goekoop-Ruiterman, Y P M; de Vries-Bouwstra, J K; Ronday, H K; Seys, P E H; Kerstens, P J S M; Huizinga, T W J; Dijkmans, B A C; Allaart, C F

    2010-07-01

    To develop a matrix model for the prediction of rapid radiographic progression (RRP) in subpopulations of patients with recent-onset rheumatoid arthritis (RA) receiving different dynamic treatment strategies. Data from 465 patients with recent-onset RA randomised to receive initial monotherapy or combination therapy were used. Predictors for RRP (increase in Sharp-van der Heijde score > or =5 after 1 year) were identified by multivariate logistic regression analysis. For subpopulations, the estimated risk of RRP per treatment group and the number needed to treat (NNT) were visualised in a matrix. The presence of autoantibodies, baseline C-reactive protein (CRP) level, erosion score and treatment group were significant independent predictors of RRP in the matrix. Combination therapy was associated with a markedly reduced risk of RRP. The positive and negative predictive values of the matrix were 62% and 91%, respectively. The NNT with initial combination therapy to prevent one patient from RRP with monotherapy was in the range 2-3, 3-7 and 7-25 for patients with a high, intermediate and low predicted risk, respectively. The matrix model visualises the risk of RRP for subpopulations of patients with recent-onset RA if treated dynamically with initial monotherapy or combination therapy. Rheumatologists might use the matrix for weighing their initial treatment choice.

  2. 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...

  3. High frequency acoustic propagation under variable sea surfaces

    Science.gov (United States)

    Senne, Joseph

    This dissertation examines the effects of rough sea surfaces and sub-surface bubbles on high frequency acoustic transmissions. Owing to the strong attenuation of electromagnetic waves in seawater, acoustic waves are used in the underwater realm much in the same way that electromagnetic waves are used in the atmosphere. The transmission and reception of acoustic waves in the underwater environment is important for a variety of fields including navigation, ocean observation, and real-time communications. Rough sea surfaces and sub-surface bubbles alter the acoustic signals that are received not only in the near-surface water column, but also at depth. This dissertation demonstrates that surface roughness and sub-surface bubbles notably affect acoustic transmissions with frequency ranges typical of underwater communications systems (10-50 kHz). The influence of rough surfaces on acoustic transmissions is determined by modeling forward propagation subject to sea surface dynamics that vary with time scales of less than a second to tens of seconds. A time-evolving rough sea surface model is combined with a rough surface formulation of a parabolic equation model for predicting time-varying acoustic fields. Linear surface waves are generated from surface wave spectra, and evolved in time using a Runge-Kutta integration technique. This evolving, range-dependent surface information is combined with other environmental parameters and fed into the acoustic model, giving an approximation of the time-varying acoustic field. The wide-angle parabolic equation model manages the rough sea surfaces by molding them into the boundary conditions for calculations of the near-surface acoustic field. The influence of sub-surface bubbles on acoustic transmissions is determined by modeling the population of bubbles near the surface and using those populations to approximate the effective changes in sound speed and attenuation. Both range-dependent and range-independent bubble models are

  4. Acoustic Fabrication via the Assembly and Fusion of Particles.

    Science.gov (United States)

    Melde, Kai; Choi, Eunjin; Wu, Zhiguang; Palagi, Stefano; Qiu, Tian; Fischer, Peer

    2017-12-04

    Acoustic assembly promises a route toward rapid parallel fabrication of whole objects directly from solution. This study reports the contact-free and maskless assembly, and fixing of silicone particles into arbitrary 2D shapes using ultrasound fields. Ultrasound passes through an acoustic hologram to form a target image. The particles assemble from a suspension along lines of high pressure in the image due to acoustic radiation forces and are then fixed (crosslinked) in a UV-triggered reaction. For this, the particles are loaded with a photoinitiator by solvent-induced swelling. This localizes the reaction and allows the bulk suspension to be reused. The final fabricated parts are mechanically stable and self-supporting. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. From Architectural Acoustics to Acoustical Architecture Using Computer Simulation

    DEFF Research Database (Denmark)

    Schmidt, Anne Marie Due; Kirkegaard, Poul Henning

    2005-01-01

    to the design of Bagsvaerd Church by Jørn Utzon. The paper discusses the advantages and disadvantages of the programme in each phase compared to the works of architects not using acoustic simulation programmes. The conclusion of the paper points towards the need to apply the acoustic simulation programmes...... 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...

  6. Engineering acoustic lenses with help from evolution

    Science.gov (United States)

    Ha˚Kansson, Andreas; Sánchez-Dehesa, José; Sánchis, Lorenzo

    2004-05-01

    Optimization engineering through evolutionary algorithms have proven to be very efficient, especially in hard problems containing a large set of optimization parameters. Like evolution this family of algorithms is able to tackle enormous complex problems with fairly simple means. Here, a simple genetic algorithm [J. H. Holland, Adaptation in Natural and Artificial Systems (Univ. of Michigan, Ann Arbor, 1975)] is used in conjunction with the multiple scattering theory [L. Sánchis et al., Phys. Rev. B 67, 035422 (2003)] to fabricate a new generation of acoustic devices based on a discrete number of cylindrical scatterers. In particular, acoustic lenses [F. Cervera et al., Phys. Rev. Lett. 88, 023902 (2002)] with flat surfaces have been designed to focus the sound in a fixed focal point for one or multiple frequencies. Each scatterer is carefully placed using the optimization method within the preset boundary conditions, to maximize the pressure contribution in the chosen focal spot. With this method acoustic lenses with very low f-numbers of the order 0.3 and with amplifications over 12 dB have been estimated using a reduced number of scatterers (~60). Preliminary results obtained from the experimental realization of the designed devices confirm our predictions.

  7. 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.

  8. Nanofibrous Resonant Membrane for Acoustic Applications

    Directory of Open Access Journals (Sweden)

    K. Kalinová

    2011-01-01

    Full Text Available Because the absorption of lower-frequency sound is problematic with fibrous material made up of coarser fibers, highly efficient sound absorption materials must be developed. The focus of this paper is on the development of a new material with high acoustic absorption characteristics. For low-frequency absorption, structures based upon the resonance principle of nanofibrous layers are employed in which the resonance of some elements allows acoustic energy to be converted into thermal energy. A nanofibrous membrane was produced by an electrostatic spinning process from an aqueous solution of polyvinyl alcohol and the acoustic characteristics of the material measured. The resonant frequency prediction for the nanofibrous membrane is based on research into its production parameters. The distance between electrodes during the electrostatic spinning process determines the average diameter of the nanofibers, and the outlet velocity of the material determines its area density. The average diameter of nanofibers was measured using the Lucia software package directly from an electron microscope image. The resonant frequency of nanofibrous membranes was determined from the sound absorption coefficient and transmission loss measurement.

  9. Aerodynamic and acoustic effects of ventricular gap.

    Science.gov (United States)

    Alipour, Fariborz; Karnell, Michael

    2014-03-01

    Supraglottic compression is frequently observed in individuals with dysphonia. It is commonly interpreted as an indication of excessive circumlaryngeal muscular tension and ventricular medialization. The purpose of this study was to describe the aerodynamic and acoustic impact of varying ventricular medialization in a canine model. Subglottal air pressure, glottal airflow, electroglottograph, acoustic signals, and high-speed video images were recorded in seven excised canine larynges mounted in vitro for laryngeal vibratory experimentation. The degree of gap between the ventricular folds was adjusted and measured using sutures and weights. Data were recorded during phonation when the ventricular gap was narrow, neutral, and large. Glottal resistance was estimated by measures of subglottal pressure and glottal flow. Glottal resistance increased systematically as ventricular gap became smaller. Wide ventricular gaps were associated with increases in fundamental frequency and decreases in glottal resistance. Sound pressure level did not appear to be impacted by the adjustments in ventricular gap used in this research. Increases in supraglottic compression and associated reduced ventricular width may be observed in a variety of disorders that affect voice quality. Ventricular compression may interact with true vocal fold posture and vibration resulting in predictable changes in aerodynamic, physiological, acoustic, and perceptual measures of phonation. The data from this report supports the theory that narrow ventricular gaps may be associated with disordered phonation. In vitro and in vivo human data are needed to further test this association. Copyright © 2014 The Voice Foundation. Published by Mosby, Inc. All rights reserved.

  10. 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

  11. Frequency steerable acoustic transducers

    Science.gov (United States)

    Senesi, Matteo

    Structural health monitoring (SHM) is an active research area devoted to the assessment of the structural integrity of critical components of aerospace, civil and mechanical systems. Guided wave methods have been proposed for SHM of plate-like structures using permanently attached piezoelectric transducers, which generate and sense waves to evaluate the presence of damage. Effective interrogation of structural health is often facilitated by sensors and actuators with the ability to perform electronic, i.e. phased array, scanning. The objective of this research is to design an innovative directional piezoelectric transducer to be employed for the localization of broadband acoustic events, or for the generation of Lamb waves for active interrogation of structural health. The proposed Frequency Steerable Acoustic Transducers (FSATs) are characterized by a spatial arrangement of active material which leads to directional characteristics varying with frequency. Thus FSATs can be employed both for directional sensing and generation of guided waves without relying on phasing and control of a large number of channels. The analytical expression of the shape of the FSATs is obtained through a theoretical formulation for continuously distributed active material as part of a shaped piezoelectric device. The FSAT configurations analyzed in this work are a quadrilateral array and a geometry which corresponds to a spiral in the wavenumber domain. The quadrilateral array is experimentally validated, confirming the concept of frequency-dependent directionality. Its limited directivity is improved by the Wavenumber Spiral FSAT (WS-FSAT), which, instead, is characterized by a continuous frequency dependent directionality. Preliminary validations of the WS-FSAT, using a laser doppler vibrometer, are followed by the implementation of the WS-FSAT as a properly shaped piezo transducer. The prototype is first used for localization of acoustic broadband sources. Signal processing

  12. Acoustic Model Testing Chronology

    Science.gov (United States)

    Nesman, Tom

    2017-01-01

    Scale models have been used for decades to replicate liftoff environments and in particular acoustics for launch vehicles. It is assumed, and analyses supports, that the key characteristics of noise generation, propagation, and measurement can be scaled. Over time significant insight was gained not just towards understanding the effects of thruster details, pad geometry, and sound mitigation but also to the physical processes involved. An overview of a selected set of scale model tests are compiled here to illustrate the variety of configurations that have been tested and the fundamental knowledge gained. The selected scale model tests are presented chronologically.

  13. Acoustic Properties of Cellulose

    Science.gov (United States)

    Trematerra, Amelia; Lombardi, Ilaria

    2017-08-01

    Cellulose is the oldest material for thermal insulation in construction field. Thomas Jefferson was the first architect that used the cellulose in his project of the Monticello house (1800). But only after 1945 that the cellulose from newsprint was used across America and northern Europe. In the 70s with the energy crisis it Austria, Czech Republic, Switzerland and Germany began the production of cellulose derived from paper newspapers. It used for both winter and summer thermal insulation, while respecting the environment. In this paper are reported acoustic measurements carried out with the tube of Kundt, with the cellulose melted and with glue with different thicknesses.

  14. Coffee roasting acoustics.

    Science.gov (United States)

    Wilson, Preston S

    2014-06-01

    Cracking sounds emitted by coffee beans during the roasting process were recorded and analyzed to investigate the potential of using the sounds as the basis for an automated roast monitoring technique. Three parameters were found that could be exploited. Near the end of the roasting process, sounds known as "first crack" exhibit a higher acoustic amplitude than sounds emitted later, known as "second crack." First crack emits more low frequency energy than second crack. Finally, the rate of cracks appearing in the second crack chorus is higher than the rate in the first crack chorus.

  15. 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.

  16. Acoustic Sensors for Air and Surface Navigation Applications.

    Science.gov (United States)

    Kapoor, Rohan; Ramasamy, Subramanian; Gardi, Alessandro; Schyndel, Ron Van; Sabatini, Roberto

    2018-02-07

    This paper presents the state-of-the-art and reviews the state-of-research of acoustic sensors used for a variety of navigation and guidance applications on air and surface vehicles. In particular, this paper focuses on echolocation, which is widely utilized in nature by certain mammals (e.g., cetaceans and bats). Although acoustic sensors have been extensively adopted in various engineering applications, their use in navigation and guidance systems is yet to be fully exploited. This technology has clear potential for applications in air and surface navigation/guidance for Intelligent Transport Systems (ITS), especially considering air and surface operations indoors and in other environments where satellite positioning is not available. Propagation of sound in the atmosphere is discussed in detail, with all potential attenuation sources taken into account. The errors introduced in echolocation measurements due to Doppler, multipath and atmospheric effects are discussed, and an uncertainty analysis method is presented for ranging error budget prediction in acoustic navigation applications. Considering the design challenges associated with monostatic and multi-static sensor implementations and looking at the performance predictions for different possible configurations, acoustic sensors show clear promises in navigation, proximity sensing, as well as obstacle detection and tracking. The integration of acoustic sensors in multi-sensor navigation systems is also considered towards the end of the paper and a low Size, Weight and Power, and Cost (SWaP-C) sensor integration architecture is presented for possible introduction in air and surface navigation systems.

  17. Acoustic measurement of bubble size in an inkjet printhead

    NARCIS (Netherlands)

    Jeurissen, R.J.M.; van der Bos, J.A.; van der Bos, Arjan; Reinten, Hans; van den Berg, Marc; Wijshoff, Herman; Wijshoff, H.; de Jong, J.; de Jong, Jos; Versluis, Michel; Lohse, Detlef

    2009-01-01

    The volume of a bubble in a piezoinkjet printhead is measured acoustically. The method is based on a numerical model of the investigated system. The piezo not only drives the system but it is also used as a sensor by measuring the current it generates. The numerical model is used to predict this

  18. Stochastic simulation of acoustic communication in turbulent shallow water

    DEFF Research Database (Denmark)

    Bjerrum-Niese, Christian; Lutzen, R.

    2000-01-01

    This paper presents a stochastic model of a turbulent shallow-water acoustic channel. The model utilizes a Monte Carlo realization method to predict signal transmission conditions. The main output from the model are statistical descriptions of the signal-to-multipath ratio (SMR) and signal fading...

  19. Accuracy of Dynamic and Acoustic Analysis of Lightweight Panel Structures

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Dickow, Kristoffer Ahrens; Andersen, Lars Vabbersgaard

    2012-01-01

    in such buildings is important. In the lowfrequency range, prediction of sound and vibration in building structures may be achieved by finite-element analysis (FEA). The aim of this paper is to compare the two commercial codes ABAQUS and ANSYS for FEA of an acoustic-structural coupling in a timber lightweight panel...

  20. Kiwi fruit (Actinidia chinensis) quality determination based on surface acoustic wave resonator combined with electronic nose.

    Science.gov (United States)

    Wei, Liu; Guohua, Hui

    2015-01-01

    In this study, electronic nose (EN) combined with a 433 MHz surface acoustic wave resonator (SAWR) was used to determine Kiwi fruit quality under 12-day storage. EN responses to Kiwi samples were measured and analyzed by principal component analysis (PCA) and stochastic resonance (SR) methods. SAWR frequency eigen values were also measured to predict freshness. Kiwi fruit sample's weight loss index and human sensory evaluation were examined to characteristic its quality and freshness. Kiwi fruit's quality predictive models based on EN, SAWR, and EN combined with SAWR were developed, respectively. Weight loss and human sensory evaluation results demonstrated that Kiwi fruit's quality decline and overall acceptance decrease during the storage. Experiment result indicated that the PCA method could qualitatively discriminate all Kiwi fruit samples with different storage time. Both SR and SAWR frequency analysis methods could successfully discriminate samples with high regression coefficients (R = 0.98093 and R = 0.99014, respectively). The validation experiment results showed that the mixed predictive model developed using EN combined with SAWR present higher quality prediction accuracy than the model developed either by EN or by SAWR. This method exhibits some advantages including high accuracy, non-destructive, low cost, etc. It provides an effective way for fruit quality rapid analysis.

  1. Studying materials using acoustic waves

    Science.gov (United States)

    Apfel, R. E.

    1988-03-01

    This final report summarizes the activity of the contractor in meeting the objectives of the contract. A comprehensive bibliography and list of participants on the contract work are included along with a discussion including: microcavitation, microparticle characterization, interfacial characterization using acoustic levitation, measurements of the acoustic nonlinear parameter for determining the composition of mixtures.

  2. 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....

  3. 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....

  4. Giving acoustics a fairer hearing.

    Science.gov (United States)

    Marriott, Ken

    2012-05-01

    Ken Marriott, an independent acoustics consultant with Industrial Commercial & Technical Consultants (ICTC), outlines some of the key acoustics considerations for those planning new hospital build or refurbishment schemes, cautioning that, all too often, this important area is not properly considered at a sufficiently early project stage.

  5. Nonlinear Acoustic Characterization of Targets

    Science.gov (United States)

    2008-01-01

    lack of advanced measurement equipment such as piezoelectric microphones and transducers, nonlinear ul- trasonic acoustics has mostly remained a...the poor coupling between solids and air, and could be more easily measured with equipment such as a Laser Doppler Vibrometer (LDV). Acoustic

  6. Distributed acoustic sensing for pipeline monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Hill, David; McEwen-King, Magnus [OptaSense, QinetiQ Ltd., London (United Kingdom)

    2009-07-01

    Optical fibre is deployed widely across the oil and gas industry. As well as being deployed regularly to provide high bandwidth telecommunications and infrastructure for SCADA it is increasingly being used to sense pressure, temperature and strain along buried pipelines, on subsea pipelines and downhole. In this paper we present results from the latest sensing capability using standard optical fibre to detect acoustic signals along the entire length of a pipeline. In Distributed Acoustic Sensing (DAS) an optical fibre is used for both sensing and telemetry. In this paper we present results from the OptaSense{sup TM} system which has been used to detect third party intervention (TPI) along buried pipelines. In a typical deployment the system is connected to an existing standard single-mode fibre, up to 50km in length, and was used to independently listen to the acoustic / seismic activity at every 10 meter interval. We will show that through the use of advanced array processing of the independent, simultaneously sampled channels it is possible to detect and locate activity within the vicinity of the pipeline and through sophisticated acoustic signal processing to obtain the acoustic signature to classify the type of activity. By combining spare fibre capacity in existing buried fibre optic cables; processing and display techniques commonly found in sonar; and state-of-the-art in fibre-optic distributed acoustic sensing, we will describe the new monitoring capabilities that are available to the pipeline operator. Without the expense of retrofitting sensors to the pipeline, this technology can provide a high performance, rapidly deployable and cost effective method of providing gapless and persistent monitoring of a pipeline. We will show how this approach can be used to detect, classify and locate activity such as; third party interference (including activity indicative of illegal hot tapping); real time tracking of pigs; and leak detection. We will also show how an

  7. Change of nonlinear acoustics in ASME grade 122 steel welded joint during creep

    Science.gov (United States)

    Ohtani, Toshihiro; Honma, Takumi; Ishii, Yutaka; Tabuchi, Masaaki; Hongo, Hiromichi; Hirao, Masahiko

    2016-02-01

    In this paper, we described the changes of two nonlinear acoustic characterizations; resonant frequency shift and three-wave interaction, with electromagnetic acoustic resonance (EMAR) throughout the creep life in the welded joints of ASME Grade 122, one of high Cr ferritic heat resisting steels. EMAR was a combination of the resonant acoustic technique with a non-contact electromagnetic acoustic transducer (EMAT). These nonlinear acoustic parameters decreased from the start to 50% of creep life. After slightly increased, they rapidly increased from 80% of creep life to rupture. We interpreted these phenomena in terms of dislocation recovery, recrystallization, and restructuring related to the initiation and growth of creep void, with support from the SEM and TEM observation.

  8. Acoustically levitated dancing drops: Self-excited oscillation to chaotic shedding

    Science.gov (United States)

    Lin, Po-Cheng; I, Lin

    2016-02-01

    We experimentally demonstrate self-excited oscillation and shedding of millimeter-sized water drops, acoustically levitated in a single-node standing waves cavity, by decreasing the steady acoustic wave intensity below a threshold. The perturbation of the acoustic field by drop motion is a possible source for providing an effective negative damping for sustaining the growing amplitude of the self-excited motion. Its further interplay with surface tension, drop inertia, gravity and acoustic intensities, select various self-excited modes for different size of drops and acoustic intensity. The large drop exhibits quasiperiodic motion from a vertical mode and a zonal mode with growing coupling, as oscillation amplitudes grow, until falling on the floor. For small drops, chaotic oscillations constituted by several broadened sectorial modes and corresponding zonal modes are self-excited. The growing oscillation amplitude leads to droplet shedding from the edges of highly stretched lobes, where surface tension no longer holds the rapid expanding flow.

  9. Wastewater treatment with acoustic separator

    Science.gov (United States)

    Kambayashi, Takuya; Saeki, Tomonori; Buchanan, Ian

    2017-07-01

    Acoustic separation is a filter-free wastewater treatment method based on the forces generated in ultrasonic standing waves. In this report, a batch-system separator based on acoustic separation was demonstrated using a small-scale prototype acoustic separator to remove suspended solids from oil sand process-affected water (OSPW). By applying an acoustic separator to the batch use OSPW treatment, the required settling time, which was the time that the chemical oxygen demand (COD) decreased to the environmental criterion (<200 mg/L), could be shortened from 10 to 1 min. Moreover, for a 10 min settling time, the acoustic separator could reduce the FeCl3 dose as coagulant in OSPW treatment from 500 to 160 mg/L.

  10. 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. .

  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. Review of Progress in Acoustic Levitation

    Science.gov (United States)

    Andrade, Marco A. B.; Pérez, Nicolás; Adamowski, Julio C.

    2017-12-01

    Acoustic levitation uses acoustic radiation forces to counteract gravity and suspend objects in mid-air. Although acoustic levitation was first demonstrated almost a century ago, for a long time, it was limited to objects much smaller than the acoustic wavelength levitating at fixed positions in space. Recent advances in acoustic levitation now allow not only suspending but also rotating and translating objects in three dimensions. Acoustic levitation is also no longer restricted to small objects and can now be employed to levitate objects larger than the acoustic wavelength. This article reviews the progress of acoustic levitation, focusing on the working mechanism of different types of acoustic levitation devices developed to date. We start with a brief review of the theory. Then, we review the acoustic levitation methods to suspend objects at fixed positions, followed by the techniques that allow the manipulation of objects. Finally, we present a brief summary and offer some future perspectives for acoustic levitation.

  13. Homogenization scheme for acoustic metamaterials

    KAUST Repository

    Yang, Min

    2014-02-26

    We present a homogenization scheme for acoustic metamaterials that is based on reproducing the lowest orders of scattering amplitudes from a finite volume of metamaterials. This approach is noted to differ significantly from that of coherent potential approximation, which is based on adjusting the effective-medium parameters to minimize scatterings in the long-wavelength limit. With the aid of metamaterials’ eigenstates, the effective parameters, such as mass density and elastic modulus can be obtained by matching the surface responses of a metamaterial\\'s structural unit cell with a piece of homogenized material. From the Green\\'s theorem applied to the exterior domain problem, matching the surface responses is noted to be the same as reproducing the scattering amplitudes. We verify our scheme by applying it to three different examples: a layered lattice, a two-dimensional hexagonal lattice, and a decorated-membrane system. It is shown that the predicted characteristics and wave fields agree almost exactly with numerical simulations and experiments and the scheme\\'s validity is constrained by the number of dominant surface multipoles instead of the usual long-wavelength assumption. In particular, the validity extends to the full band in one dimension and to regimes near the boundaries of the Brillouin zone in two dimensions.

  14. 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...

  15. Acoustic Resonance Disruption of Microspheres and E. coli

    Science.gov (United States)

    Keady, John Patrick

    This thesis describes a method of modelling bacterial growth which uses the ratio of bacterial growth curves of a test sample to a control sample to determine variation in initial experimental conditions, variation in final nutrient levels, and ratio of live bacteria remaining in test sample compared to the control. The method of modelling bacterial growth is used to measure acoustic eradication of E. coli DH5? using targeting frequencies observed from acoustic emissions of E. coli strains W1485, MG1655, and MC1060. Eradication levels greater than 20% were achieved for frequencies of 15398.5Hz, 22250Hz, 23210Hz, and 28100Hz for exposure times of 4 minutes. Acoustic emission data was then used to derive a Young's Modulus value of E=2.213813 Pa for E. coli DH5?, which was then used in a linear elastic oscillation model to predict more accurate targeting frequencies. The model derived targeting frequencies resulted in eradication levels greater than 40% for frequencies of 15635.148Hz, 15731.808Hz, and 15856.660Hz. Host cell (Vero cells) experiments using trypan blue and MTT assay indicate that there is no apparent surface disruption or loss of Mitochondrial metabolism of acoustically exposed Vero cells at the predicted targeting frequencies. Finally, two methods of determining acoustic targeting frequencies to use in sterilizing bacteria are described. The first method involves using Acoustic Emissions to determine target frequencies, and the second method using physical properties of a pathogen in a model to derive predicted targeting frequencies. The conclusion is that a hybrid combination of the two methods is needed.

  16. Acoustic Analysis of Nasal Vowels in Monguor Language

    Science.gov (United States)

    Zhang, Hanbin

    2017-09-01

    The purpose of the study is to analyze the spectrum characteristics and acoustic features for the nasal vowels [ɑ˜] and [ɔ˜] in Monguor language. On the base of acoustic parameter database of the Monguor speech, the study finds out that there are five main zero-pole pairs appearing for the nasal vowel [ɔ˜] and two zero-pole pairs appear for the nasal vowel [ɔ˜]. The results of regression analysis demonstrate that the duration of the nasal vowel [ɔ˜] or the nasal vowel [ɔ˜] can be predicted by its F1, F2 and F3 respectively.

  17. Identifying Technical Condition of Vehicle Gearbox Using Acoustic Emission

    Science.gov (United States)

    Furch, Jan; Glos, Josef

    2017-06-01

    The article examines the technical condition of rotating parts using acoustic diagnostics. The measured object was a mechanical transmission of a field vehicle. Recently this method has been developing very quickly and is expected to be used not only for the signal analysis itself, but also for the failure occurrence prediction which is our aim in the future. In our article we observe the technical condition of a four-speed transmission and analyse the acoustic signal expressed by the root mean square of a noise level in decibels.

  18. Acoustic signal propagation characterization of conduit networks

    Science.gov (United States)

    Khan, Muhammad Safeer

    Analysis of acoustic signal propagation in conduit networks has been an important area of research in acoustics. One major aspect of analyzing conduit networks as acoustic channels is that a propagating signal suffers frequency dependent attenuation due to thermo-viscous boundary layer effects and the presence of impedance mismatches such as side branches. The signal attenuation due to side branches is strongly influenced by their numbers and dimensions such as diameter and length. Newly developed applications for condition based monitoring of underground conduit networks involve measurement of acoustic signal attenuation through tests in the field. In many cases the exact installation layout of the field measurement location may not be accessible or actual installation may differ from the documented layout. The lack of exact knowledge of numbers and lengths of side branches, therefore, introduces uncertainty in the measurements of attenuation and contributes to the random variable error between measured results and those predicted from theoretical models. There are other random processes in and around conduit networks in the field that also affect the propagation of an acoustic signal. These random processes include but are not limited to the presence of strong temperature and humidity gradients within the conduits, blockages of variable sizes and types, effects of aging such as cracks, bends, sags and holes, ambient noise variations and presence of variable layer of water. It is reasonable to consider that the random processes contributing to the error in the measured attenuation are independent and arbitrarily distributed. The error, contributed by a large number of independent sources of arbitrary probability distributions, is best described by an approximately normal probability distribution in accordance with the central limit theorem. Using an analytical approach to model the attenuating effect of each of the random variable sources can be very complex and

  19. Coupled Acoustic-Mechanical Bandgaps

    DEFF Research Database (Denmark)

    Jensen, Jakob Søndergaard; Kook, Junghwan

    2016-01-01

    In this work, we study the existence of coupled bandgaps for corrugated plate structures and acoustic channels. The study is motivated by the observation that the performance of traditional bandgap structures, such as periodic plates, may be compromised due to the coupling to a surrounding acoust...... domains into account. Additionally, the coupling is shown to introduce extra gaps in the band structure due to modal interaction and the appearance of a cut-on frequency for the fundamental acoustic mode.......In this work, we study the existence of coupled bandgaps for corrugated plate structures and acoustic channels. The study is motivated by the observation that the performance of traditional bandgap structures, such as periodic plates, may be compromised due to the coupling to a surrounding acoustic...... medium and the presence of acoustic resonances. It is demonstrated that corrugation of the plate structure can introduce bending wave bandgaps and bandgaps in the acoustic domain in overlapping and audible frequency ranges. This effect is preserved also when taking the physical coupling between the two...

  20. PORTABLE ACOUSTIC MONITORING PACKAGE (PAMP)

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-07-20

    The Portable Acoustic Monitoring Package (PAMP) has been designed to record and monitor the acoustic signal in natural gas transmission lines. In particular the three acoustic signals associated with a line leak. The system is portable ({approx}30 lbs) and is designed for line pressures up to 1000 psi. It has become apparent that cataloging of the various background acoustic signals in natural gas transmission line is very important if a system to identify leak signals is to be developed. The low-pressure (0-200 psig) laboratory test phase has been completed and a number of field trials have been conducted. Before the cataloging phase could begin, a few problems identified in field trials identified had to be corrected such as: (1) Decreased microphone sensitivity at line pressures above 250 psig. (2) The inability to deal with large data sets collected when cataloging the variety of signals in a transmission line. (3) The lack of an available online acoustic calibration system. These problems have been solved and the WVU PAMP is now fully functional over the entire pressure range found in the Natural Gas transmission lines in this region. Field portability and reliability have been greatly improved. Data collection and storage have also improved to the point were the full acoustic spectrum of acoustic signals can be accurately cataloged, recorded and described.