WorldWideScience

Sample records for acoustic chemometric monitoring

  1. Near infrared and acoustic chemometrics monitoring of volatile fatty acids and dry matter during co-digestion of manure and maize silage

    DEFF Research Database (Denmark)

    Lomborg, Carina J.; Holm-Nielsen, Jens Bo; Oleskowicz-Popiel, Piotr

    2009-01-01

    In this study, two process analytical technologies, near infrared spectroscopy and acoustic chemometrics, were investigated as means of monitoring a maize silage spiked biogas process. A reactor recirculation loop which enables sampling concomitant with on-line near infrared characterisation...

  2. 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.

  3. Fluorescence Spectroscopy and Chemometric Modeling for Bioprocess Monitoring

    Directory of Open Access Journals (Sweden)

    Saskia M. Faassen

    2015-04-01

    Full Text Available On-line sensors for the detection of crucial process parameters are desirable for the monitoring, control and automation of processes in the biotechnology, food and pharma industry. Fluorescence spectroscopy as a highly developed and non-invasive technique that enables the on-line measurements of substrate and product concentrations or the identification of characteristic process states. During a cultivation process significant changes occur in the fluorescence spectra. By means of chemometric modeling, prediction models can be calculated and applied for process supervision and control to provide increased quality and the productivity of bioprocesses. A range of applications for different microorganisms and analytes has been proposed during the last years. This contribution provides an overview of different analysis methods for the measured fluorescence spectra and the model-building chemometric methods used for various microbial cultivations. Most of these processes are observed using the BioView® Sensor, thanks to its robustness and insensitivity to adverse process conditions. Beyond that, the PLS-method is the most frequently used chemometric method for the calculation of process models and prediction of process variables.

  4. Monitoring Industrial Food Processes Using Spectroscopy & Chemometrics

    DEFF Research Database (Denmark)

    Pedersen, Dorthe Kjær; Engelsen, Søren Balling

    2001-01-01

    In the last decade rapid spectroscopic measurements have revolutionized quality control in practically all areas of primary food and feed production. Near-infrared spectroscopy (NIR & NIT) has been implemented for monitoring the quality of millions of samples of cereals, milk and meat with unprec......In the last decade rapid spectroscopic measurements have revolutionized quality control in practically all areas of primary food and feed production. Near-infrared spectroscopy (NIR & NIT) has been implemented for monitoring the quality of millions of samples of cereals, milk and meat...

  5. Bioreactor monitoring with spectroscopy and chemometrics: a review.

    Science.gov (United States)

    Lourenço, N D; Lopes, J A; Almeida, C F; Sarraguça, M C; Pinheiro, H M

    2012-09-01

    Biotechnological processes are crucial to the development of any economy striving to ensure a relevant position in future markets. The cultivation of microorganisms in bioreactors is one of the most important unit operations of biotechnological processes, and real-time monitoring of bioreactors is essential for effective bioprocess control. In this review, published material on the potential application of different spectroscopic techniques for bioreactor monitoring is critically discussed, with particular emphasis on optical fiber technology, reported for in situ bioprocess monitoring. Application examples are presented by spectroscopy type, specifically focusing on ultraviolet-visible, near-infrared, mid-infrared, Raman, and fluorescence spectroscopy. The spectra acquisition devices available and the major advantages and disadvantages of each spectroscopy are discussed. The type of information contained in the spectra and the available chemometric methods for extracting that information are also addressed, including wavelength selection, spectra pre-processing, principal component analysis, and partial least-squares. Sample handling techniques (flow and sequential injection analysis) that include transport to spectroscopic sensors for ex-situ on-line monitoring are not covered in this review.

  6. The synthesis of metoprolol monitored using Raman spectroscopy and chemometrics.

    Science.gov (United States)

    Svensson, O; Josefson, M; Langkilde, F W

    2000-08-01

    The synthesis of Metoprolol base was studied using Raman spectroscopy with a 785-nm laser, optical fibres, a holographic transmission grating, confocal optics and a charge-coupled device (CCD) detector. The reaction mixture was heated according to a temperature gradient and spectra of the reaction mixture were obtained by focusing the laser beam through ordinary reaction flasks. Because of overlapping bands, multivariate techniques such as principal components analysis (PCA) and partial least-squares projections to latent structures (PLS) were used in the evaluation of the obtained spectra. The use of PCA or PLS against time does not require any calibration samples and a quantitative calibration is not necessary in order to monitor the reaction. A method for reaction endpoint determination, based on euclidean distances in the score space, is presented. The use of multivariate batch control charts have been demonstrated and a number of problems and solutions regarding the sample presentation have been discussed. The effect of spectral pretreatment on the multivariate results is shown and discussed. The monitoring results show that the time to produce Metoprolol base could be reduced.

  7. Acoustic Monitoring for Spaceflight Vehicle Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR will develop and demonstrate acoustic sensor technology enabling real-time, remotely performed measuring and monitoring of sound pressure levels and noise...

  8. Multivariate chemometric approach to thermal solid-state FT-IR monitoring of pharmaceutical drug compound.

    Science.gov (United States)

    Tan, Wei Jian; Widjaja, Effendi

    2008-08-01

    The study of thermal-related solid-state reaction monitored by spectroscopic method needs the use of advanced multivariate chemometric approach. It is because visual inspection of spectral data on particular functional groups or spectral bands is difficult to reveal the complete physical and chemical information. The spectral contributions from various species involved in the solid-state changes are generally highly overlapping and the spectral differences between reactant and product are usually quite minute. In this article, we demonstrate the use of multivariate chemometric approach to resolve the in situ thermal-dependent Fourier-transform infrared (FT-IR) mixture spectra of lisinopril dihydrate when it was heated from 24 to 170 degrees C. The collected FT-IR mixture spectra were first subjected to singular value decomposition (SVD) to obtain the right singular vectors. The right singular vectors were rotated into a set of pure component spectral estimates based on entropy minimization and spectral dissimilarity objective functions. The resulting pure component spectral estimates were then further refined using alternating least squares (ALS). In current study, four pure component spectra, that is, lisinopril dihydrate, monohydrate, anhydrate, and diketopiperazine (DKP) were all resolved and the relative thermal-dependent contributions of each component were also obtained. These relative contributions revealed the critical temperature for each transformation and degradation. This novel approach provides better interpretation of the pathway of dehydration and intramolecular cyclization of lisinopril dihydrate in the solid state. In addition, it can be used to complement the information obtained from differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA).

  9. Acoustic Techniques for Structural Health Monitoring

    Science.gov (United States)

    Frankenstein, B.; Augustin, J.; Hentschel, D.; Schubert, F.; Köhler, B.; Meyendorf, N.

    2008-02-01

    Future safety and maintenance strategies for industrial components and vehicles are based on combinations of monitoring systems that are permanently attached to or embedded in the structure, and periodic inspections. The latter belongs to conventional nondestructive evaluation (NDE) and can be enhanced or partially replaced by structural health monitoring systems. However, the main benefit of this technology for the future will consist of systems that can be differently designed based on improved safety philosophies, including continuous monitoring. This approach will increase the efficiency of inspection procedures at reduced inspection times. The Fraunhofer IZFP Dresden Branch has developed network nodes, miniaturized transmitter and receiver systems for active and passive acoustical techniques and sensor systems that can be attached to or embedded into components or structures. These systems have been used to demonstrate intelligent sensor networks for the monitoring of aerospace structures, railway systems, wind energy generators, piping system and other components. Material discontinuities and flaws have been detected and monitored during full scale fatigue testing. This paper will discuss opportunities and future trends in nondestructive evaluation and health monitoring based on new sensor principles and advanced microelectronics. It will outline various application examples of monitoring systems based on acoustic techniques and will indicate further needs for research and development.

  10. Binding of 8-methoxypsoralen to DNA in vitro: Monitoring by spectroscopic and chemometrics approaches

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Xiaoyue; Zhang, Guowen, E-mail: gwzhang@ncu.edu.cn; Wang, Langhong

    2014-10-15

    8-Methoxypsoralen (8-MOP) is a naturally occurring furanocoumarin with a variety of biological and pharmacological activities. The binding mechanism of 8-MOP to calf thymus DNA (ctDNA) at physiological pH was investigated by multi-spectroscopic techniques including UV–vis absorption, fluorescence, circular dichroism (CD) and Fourier transform infrared (FT-IR) spectroscopy along with DNA melting studies and viscosity measurements. The multivariate curve resolution-alternating least squares (MCR-ALS) chemometrics approach was introduced to resolve the expanded UV–vis spectral data matrix, and both the pure spectra and the equilibrium concentration profiles for the components (8-MOP, ctDNA and 8-MOP-ctDNA complex) in the system were successfully obtained to monitor the 8-MOP-ctDNA interaction. The results suggested that 8-MOP could bind to ctDNA via intercalation binding as evidenced by significant increases in melting and relative viscosity of ctDNA and competitive study using acridine orange (AO) as a fluorescence probe. The positive values of enthalpy and entropy change suggested that hydrogen bonds and van der Waals forces played a predominant role in the binding process. Further, FT-IR and CD spectra analysis indicated that 8-MOP preferentially bound to A–T base pairs with no major perturbation in ctDNA double helix conformation. Moreover, molecular docking was employed to exhibit the specific binding mode of 8-MOP to ctDNA intuitively. - Highlights: • The interaction processes of 8-MOP with ctDNA was monitored by MCR-ALS approach. • The binding mode of 8-MOP to ctDNA was an intercalation. • 8-MOP most likely bound to adenine and thymine base pairs of ctDNA. • Molecular docking illustrated the specific binding.

  11. Interaction between 8-methoxypsoralen and trypsin: Monitoring by spectroscopic, chemometrics and molecular docking approaches

    Science.gov (United States)

    Liu, Yingying; Zhang, Guowen; Zeng, Ni; Hu, Song

    2017-02-01

    8-Methoxypsoralen (8-MOP) is a naturally occurring furanocoumarin with various biological activities. However, there is little information on the binding mechanism of 8-MOP with trypsin. Here, the interaction between 8-MOP and trypsin in vitro was determined by multi-spectroscopic methods combined with the multivariate curve resolution-alternating least squares (MCR-ALS) chemometrics approach. An expanded UV-vis spectral data matrix was analysed by MCR-ALS, the concentration profiles and pure spectra for the three reaction species (trypsin, 8-MOP and 8-MOP-trypsin) were obtained to monitor the interaction between 8-MOP and trypsin. The fluorescence data suggested that a static type of quenching mechanism occurred in the binding of 8-MOP to trypsin. Hydrophobic interaction dominated the formation of the 8-MOP-trypsin complex on account of the positive enthalpy and entropy changes, and trypsin had one high affinity binding site for 8-MOP with a binding constant of 3.81 × 104 L mol- 1 at 298 K. Analysis of three dimensional fluorescence, UV-vis absorption and circular dichroism spectra indicated that the addition of 8-MOP induced the rearrangement of the polypeptides carbonyl hydrogen-bonding network and the conformational changes in trypsin. The molecular docking predicted that 8-MOP interacted with the catalytic residues His57, Asp102 and Ser195 in trypsin. The binding patterns and trypsin conformational changes may result in the inhibition of trypsin activity. This study has provided insights into the binding mechanism of 8-MOP with trypsin.

  12. 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

  13. Acoustic emission monitoring of wind turbine blades

    Science.gov (United States)

    Van Dam, Jeremy; Bond, Leonard J.

    2015-03-01

    Damage to wind turbine blades can, if left uncorrected, evolve into catastrophic failures resulting in high costs and significant losses for the operator. Detection of damage, especially in real time, has the potential to mitigate the losses associated with such catastrophic failure. To address this need various forms of online monitoring are being investigated, including acoustic emission detection. In this paper, pencil lead breaks are used as a standard reference source and tests are performed on unidirectional glass-fiber-reinforced-polymer plates. The mechanical pencil break is used to simulate an acoustic emission (AE) that generates elastic waves in the plate. Piezoelectric sensors and a data acquisition system are used to detect and record the signals. The expected dispersion curves generated for Lamb waves in plates are calculated, and the Gabor wavelet transform is used to provide dispersion curves based on experimental data. AE sources using an aluminum plate are used as a reference case for the experimental system and data processing validation. The analysis of the composite material provides information concerning the wave speed, modes, and attenuation of the waveform, which can be used to estimate maximum AE event - receiver separation, in a particular geometry and materials combination. The foundational data provided in this paper help to guide improvements in online structural health monitoring of wind turbine blades using acoustic emission.

  14. Acoustic Flow Monitor System - User Manual

    Science.gov (United States)

    LaHusen, Richard

    2005-01-01

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

  15. Condition Monitoring and Management from Acoustic Emissions

    DEFF Research Database (Denmark)

    Pontoppidan, Niels Henrik Bohl

    2005-01-01

    In the following, I will use technical terms without explanation as it gives the freedom to describe the project in a shorter form for those who already know. The thesis is about condition monitoring of large diesel engines from acoustic emission signals. The experiments have been focused...... is the analysis of the angular position changes of the engine related events such as fuel injection and valve openings, caused by operational load changes. With inspiration from speech recognition and voice effects the angular timing changes have been inverted with the event alignment framework. With the event...

  16. Introducing passive acoustic filter in acoustic based condition monitoring: Motor bike piston-bore fault identification

    Science.gov (United States)

    Jena, D. P.; Panigrahi, S. N.

    2016-03-01

    Requirement of designing a sophisticated digital band-pass filter in acoustic based condition monitoring has been eliminated by introducing a passive acoustic filter in the present work. So far, no one has attempted to explore the possibility of implementing passive acoustic filters in acoustic based condition monitoring as a pre-conditioner. In order to enhance the acoustic based condition monitoring, a passive acoustic band-pass filter has been designed and deployed. Towards achieving an efficient band-pass acoustic filter, a generalized design methodology has been proposed to design and optimize the desired acoustic filter using multiple filter components in series. An appropriate objective function has been identified for genetic algorithm (GA) based optimization technique with multiple design constraints. In addition, the sturdiness of the proposed method has been demonstrated in designing a band-pass filter by using an n-branch Quincke tube, a high pass filter and multiple Helmholtz resonators. The performance of the designed acoustic band-pass filter has been shown by investigating the piston-bore defect of a motor-bike using engine noise signature. On the introducing a passive acoustic filter in acoustic based condition monitoring reveals the enhancement in machine learning based fault identification practice significantly. This is also a first attempt of its own kind.

  17. Acoustic Monitoring of the Arctic Ice Cap

    Science.gov (United States)

    Porter, D. L.; Goemmer, S. A.; Chayes, D. N.

    2012-12-01

    Introduction The monitoring of the Arctic Ice Cap is important economically, tactically, and strategically. In the scenario of ice cap retreat, new paths of commerce open, e.g. waterways from Northern Europe to the Far East. Where ship-going commerce is conducted, the U.S. Navy and U.S. Coast Guard have always stood guard and been prepared to assist from acts of nature and of man. It is imperative that in addition to measuring the ice from satellites, e.g. Icesat, that we have an ability to measure the ice extent, its thickness, and roughness. These parameters play an important part in the modeling of the ice and the processes that control its growth or shrinking and its thickness. The proposed system consists of three subsystems. The first subsystem is an acoustic source, the second is an array of geophones and the third is a system to supply energy and transmit the results back to the analysis laboratory. The subsystems are described below. We conclude with a plan on how to tackle this project and the payoff to the ice cap modeler and hence the users, i.e. commerce and defense. System Two historically tested methods to generate a large amplitude multi-frequency sound source include explosives and air guns. A new method developed and tested by the University of Texas, ARL is a combustive Sound Source [Wilson, et al., 1995]. The combustive sound source is a submerged combustion chamber that is filled with the byproducts of the electrolysis of sea water, i.e. Hydrogen and Oxygen, an explosive mixture which is ignited via a spark. Thus, no additional compressors, gases, or explosives need to be transported to the Arctic to generate an acoustic pulse capable of the sediment and the ice. The second subsystem would be geophones capable of listening in the O(10 Hz) range and transmitting that data back to the laboratory. Thus two single arrays of geophones arranged orthogonal to each other with a range of 1000's of kilometers and a combustive sound source where the two

  18. Acoustic Signature Monitoring and Management of Naval Platforms

    NARCIS (Netherlands)

    Basten, T.G.H.; Jong, C.A.F. de; Graafland, F.; Hof, J. van 't

    2015-01-01

    Acoustic signatures make naval platforms susceptible to detection by threat sensors. The variable operational conditions and lifespan of a platform cause variations in the acoustic signature. To deal with these variations, a real time signature monitoring capability is being developed, with advisory

  19. Protective behaviour monitoring on wood photo-degradation by spectroscopic techniques coupled with chemometrics

    Science.gov (United States)

    Capobianco, Giuseppe; Calienno, Luca; Pelosi, Claudia; Scacchi, Martina; Bonifazi, Giuseppe; Agresti, Giorgia; Picchio, Rodolfo; Santamaria, Ulderico; Serranti, Silvia; Monaco, Angela Lo

    2017-02-01

    This paper reports the investigation on the effect of protective materials on poplar (Populus sp.) wood modifications as consequence of artificial photo-degradation in controlled environment. The novelty of this work is to try to understand what happens to wood surface under the protective layer. Shellac, beeswax and Linfoil® were tested to compare traditional and novel products generally used for wood. The samples, uncovered and covered by these protective layers, were artificially aged. Colour and chemical modifications due to ageing were investigated at different time intervals by reflectance spectrophotometry, Fourier transform infrared spectroscopy and hyperspectral imaging. The obtained data were elaborated by statistical and chemometric tools in order to verify their significance and to assess the relationship between groups of measurements. The results highlighted that shellac, beeswax and Linfoil® materials have a very low protective effect on wood photo-degradation for long times of exposure, by little reducing the changes of wood components.

  20. Chemometric methods applied to the calibration of a Vis-NIR sensor for gas engine's condition monitoring.

    Science.gov (United States)

    Villar, Alberto; Gorritxategi, Eneko; Otaduy, Deitze; Ciria, Jose I; Fernandez, Luis A

    2011-10-31

    This paper describes the calibration process of a Visible-Near Infrared sensor for the condition monitoring of a gas engine's lubricating oil correlating transmittance oil spectra with the degradation of a gas engine's oil via a regression model. Chemometric techniques were applied to determine different parameters: Base Number (BN), Acid Number (AN), insolubles in pentane and viscosity at 40 °C. A Visible-Near Infrared (400-1100 nm) sensor developed in Tekniker research center was used to obtain the spectra of artificial and real gas engine oils. In order to improve sensor's data, different preprocessing methods such as smoothing by Saviztky-Golay, moving average with Multivariate Scatter Correction or Standard Normal Variate to eliminate the scatter effect were applied. A combination of these preprocessing methods was applied to each parameter. The regression models were developed by Partial Least Squares Regression (PLSR). In the end, it was shown that only some models were valid, fulfilling a set of quality requirements. The paper shows which models achieved the established validation requirements and which preprocessing methods perform better. A discussion follows regarding the potential improvement in the robustness of the models.

  1. A Flexible Acoustic Sensor Network for Various Monitoring Applications

    NARCIS (Netherlands)

    Basten, T.G.H.; Wessels, P.W.

    2013-01-01

    Acoustic monitoring using a sensor network is a powerful instrument to assess and manage complex noise situations. It can provide a basis to identify appropriate and cost effective measures, and to assess their effect by comparing before and after implementation. It can also be an instrument for com

  2. Acoustic monitoring of a fluidized bed coating process

    DEFF Research Database (Denmark)

    Naelapaa, Kaisa; Veski, Peep; Pedersen, Joan G.;

    2007-01-01

      The aim of the study was to investigate the potential of acoustic monitoring of a production scale fluidized bed coating process. The correlation between sensor signals and the estimated amount of film applied and percentage release, respectively, were investigated in coating potassium chloride...

  3. 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 e

  4. Advanced Technologies for Acoustic Monitoring of Bird Populations

    Science.gov (United States)

    2009-04-01

    Grasshopper Sparrow Henslow’s Sparrow Detection and classification software for songs/calls of target species The Bioacoustics Research Program has...instruments and signal detection and classification software has the potential to lead to improved monitoring of bird populations on DoD lands and elsewhere...the area surveyed. These hardware and software tools can also enable passive acoustic monitoring of nocturnally migrating birds across large

  5. Cider fermentation process monitoring by Vis-NIR sensor system and chemometrics.

    Science.gov (United States)

    Villar, Alberto; Vadillo, Julen; Santos, Jose I; Gorritxategi, Eneko; Mabe, Jon; Arnaiz, Aitor; Fernández, Luis A

    2017-04-15

    Optimization of a multivariate calibration process has been undertaken for a Visible-Near Infrared (400-1100nm) sensor system, applied in the monitoring of the fermentation process of the cider produced in the Basque Country (Spain). The main parameters that were monitored included alcoholic proof, l-lactic acid content, glucose+fructose and acetic acid content. The multivariate calibration was carried out using a combination of different variable selection techniques and the most suitable pre-processing strategies were selected based on the spectra characteristics obtained by the sensor system. The variable selection techniques studied in this work include Martens Uncertainty test, interval Partial Least Square Regression (iPLS) and Genetic Algorithm (GA). This procedure arises from the need to improve the calibration models prediction ability for cider monitoring.

  6. Acoustic emission monitoring using a multimode optical fiber sensor

    Science.gov (United States)

    Vandenplas, Steve; Papy, Jean-Michel; Wevers, Martine; Van Huffel, Sabine

    2004-07-01

    Permanent damage in various materials and constructions often causes high-energy high-frequency acoustic waves. To detect those so called `acoustic emission (AE) events', in most cases ultrasonic transducers are embedded in the structure or attached to its surface. However, for many applications where event localization is less important, an embedded low-cost multimode optical fiber sensor configured for event counting may be a better alternative due to its corrosion resistance, immunity to electromagnetic interference and light-weight. The sensing part of this intensity-modulated sensor consists of a multimode optical fiber. The sensing principle now relies on refractive index variations, microbending and mode-mode interferences by the action of the acoustic pressure wave. A photodiode is used to monitor the intensity of the optical signal and transient signal detection techniques (filtering, frame-to-frame analysis, recursive noise estimation, power detector estimator) on the photodiode output are applied to detect the events. In this work, the acoustic emission monitoring capabilities of the multimode optical fiber sensor are demonstrated with the fiber sensor embedded in the liner of a Power Data Transmission (PDT) coil to detect damage (delamination, matrix cracking and fiber breaking) while bending the coil. With the Hankel Total Least Square (HTLS) technique, it is shown that both the acoustic emission signal and optical signal can be modeled with a sum of exponentially damped complex sinusoids with common poles.

  7. Sensor combination and chemometric variable selection for online monitoring of Streptomyces coelicolor fed-batch cultivations

    DEFF Research Database (Denmark)

    Ödman, Peter; Johansen, C.L.; Olsson, L.

    2010-01-01

    Fed-batch cultivations of Streptomyces coelicolor, producing the antibiotic actinorhodin, were monitored online by multiwavelength fluorescence spectroscopy and off-gas analysis. Partial least squares (PLS), locally weighted regression, and multilinear PLS (N-PLS) models were built for prediction...

  8. Acoustic monitoring systems tests at Indian Point Unit 1. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Smith, J.R.; Rao, G.V.; Craig, J.

    1979-12-01

    This report describes the results of a program to test acoustic monitoring systems on Indian Point Unit No. 1 under actual plant operating conditions, less the reactor core. The two types of systems evaluated were the monitoring of acoustic emissions generated by growing flaws and the monitoring of acoustic signals from leaks.

  9. Urban air quality assessment using monitoring data of fractionized aerosol samples, chemometrics and meteorological conditions.

    Science.gov (United States)

    Yotova, Galina I; Tsitouridou, Roxani; Tsakovski, Stefan L; Simeonov, Vasil D

    2016-01-01

    The present article deals with assessment of urban air by using monitoring data for 10 different aerosol fractions (0.015-16 μm) collected at a typical urban site in City of Thessaloniki, Greece. The data set was subject to multivariate statistical analysis (cluster analysis and principal components analysis) and, additionally, to HYSPLIT back trajectory modeling in order to assess in a better way the impact of the weather conditions on the pollution sources identified. A specific element of the study is the effort to clarify the role of outliers in the data set. The reason for the appearance of outliers is strongly related to the atmospheric condition on the particular sampling days leading to enhanced concentration of pollutants (secondary emissions, sea sprays, road and soil dust, combustion processes) especially for ultra fine and coarse particles. It is also shown that three major sources affect the urban air quality of the location studied-sea sprays, mineral dust and anthropogenic influences (agricultural activity, combustion processes, and industrial sources). The level of impact is related to certain extent to the aerosol fraction size. The assessment of the meteorological conditions leads to defining of four downwind patterns affecting the air quality (Pelagic, Western and Central Europe, Eastern and Northeastern Europe and Africa and Southern Europe). Thus, the present study offers a complete urban air assessment taking into account the weather conditions, pollution sources and aerosol fractioning.

  10. Passive Autonomous Acoustic Monitoring of Marine Mammals with Seagliders

    Science.gov (United States)

    2012-09-30

    odontocetes recorded in the Southern California Bight: bottlenose dolphins ( Tursiops truncatus ), short- and long-beaked common dolphins (Delphinus delphis...Bell, Julie Rivers ) about deploying this acoustically-equipped Seaglider for marine mammal monitoring at sites of interest to the Navy, particularly...Haykin, S. 2002. Adaptive Filter Theory. Prentice-Hall, Upper Saddle River . Hu, Y. and Loizou, P. 2002. A subspace approach for enhancing speech

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

    Directory of Open Access Journals (Sweden)

    A. Galgaro

    2005-01-01

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

  12. An acoustic sensor for monitoring airflow in pediatric tracheostomy patients.

    Science.gov (United States)

    Ruscher, Thomas; Wicks Phd, Alexandrina; Muelenaer Md, Andre

    2012-01-01

    Without proper monitoring, patients with artificial airways in the trachea are at high risk for complications or death. Despite routine maintenance of the tube, dislodged or copious mucus can obstruct the airway. Young children ( 3yrs) have difficulty tending to their own tubes and are particularly vulnerable to blockages. They require external respiratory sensors. In a hospital environment, ventilators, end-tidal CO2 monitors, thermistors, and other auxiliary equipment provide sufficient monitoring of respiration. However, outpatient monitoring methods, such as thoracic impedance and pulse oximetry, are indirect and prone to false positives. Desensitization of caregivers to frequent false alarms has been cited in medical literature as a contributing factor in cases of child death. Ultrasonic time-of-flight (TOF) is a technique used in specialized industrial applications to non-invasively measure liquid and gas flow. Two transducers are oriented at a diagonal across a flow channel. Velocity measurement is accomplished by detecting slight variations in transit time of contra-propagating acoustic signals with a directional component parallel to air flow. Due to the symmetry of acoustic pathway between sensors, velocity measurements are immune to partial fouling in the tube from mucus, saliva, and condensation. A first generation proof of concept prototype was constructed to evaluate the ultrasonic TOF technique for medical tracheostomy monitoring. After successful performance, a second generation prototype was designed with a smaller form factor and more advanced electronics. This prototype was tested and found to measure inspired volume with a root-mean-square error < 2% during initial trials.

  13. Use of information system data of jet crushing acoustic monitoring for the process management

    Directory of Open Access Journals (Sweden)

    T.M. Bulanaya

    2012-12-01

    Full Text Available The graphic interpretation of amplitude and frequency of acoustic signals of loose material jet grinding process are resulted. Criteria of process management is determined on the basis of the acoustic monitoring data of jet mill acting.

  14. Employing Acoustic Emission for Monitoring Oil Film Regimes

    Directory of Open Access Journals (Sweden)

    David Mba

    2013-07-01

    Full Text Available The major purpose of a gear lubricant is to provide adequate oil film thickness to reduce and prevent gear tooth surface failures. Real time monitoring for gear failures is important in order to predict and prevent unexpected failures which would have a negative impact on the efficiency, performance and safety of the gearbox. This paper presents experimental results on the influence of specific oil film thickness on Acoustic Emission (AE activity for operational helical gears. Variation in film thickness during operations was achieved by spraying liquid nitrogen onto the rotating gear wheel. The experimental results demonstrated a clear relationship between the root mean square (r.m.s value of the AE signal and the specific film thickness. The findings demonstrate the potential of Acoustic Emission technology to quantify lubrication regimes on operational gears.

  15. Fracture of Human Femur Tissue Monitored by Acoustic Emission Sensors

    Directory of Open Access Journals (Sweden)

    Dimitrios. G. Aggelis

    2015-03-01

    Full Text Available The study describes the acoustic emission (AE activity during human femur tissue fracture. The specimens were fractured in a bending-torsion loading pattern with concurrent monitoring by two AE sensors. The number of recorded signals correlates well with the applied load providing the onset of micro-fracture at approximately one sixth of the maximum load. Furthermore, waveform frequency content and rise time are related to the different modes of fracture (bending of femur neck or torsion of diaphysis. The importance of the study lies mainly in two disciplines. One is that, although femurs are typically subjects of surgical repair in humans, detailed monitoring of the fracture with AE will enrich the understanding of the process in ways that cannot be achieved using only the mechanical data. Additionally, from the point of view of monitoring techniques, applying sensors used for engineering materials and interpreting the obtained data pose additional difficulties due to the uniqueness of the bone structure.

  16. Monitoring of Robot Assisted Polishing through parameters of acoustic emission

    DEFF Research Database (Denmark)

    Lazarev, Ruslan; Top, Søren; Bilberg, Arne

    , the duration of each process stage and predict the end of process in a precise and unmanned way. This paper presents and analyses the utilization of acoustic emission for generation of control signals in the stone polishing process for achieving these control objectives in an industrial set-up prototype........ The determination of the point in time to change a polishing media or stop the process is needed for computer controlled functional surface generation. During the last years, several research works have been done in order to build grinding/polishing monitoring systems to determine process characteristics...

  17. SensIs - Underwater acoustic network for ice-monitoring

    CERN Document Server

    Reinen, Tor Arne; Knudsen, Finn Tore

    2016-01-01

    Routing for low latency underwater acoustic network-communication is investigated. The application is monitoring of ice-threats to offshore operations in the Arctic - to provide warnings that enable operators to react to such threats. The scenario produces relatively high traffic load, and the network should favour low delay and adequate reliability rather than energy usage minimization. The ICRP (Information-Carrying based Routing Protocol), originally proposed by Wei Liang et al. in 2007, is chosen as basis. ICRP obtains unicast routing paths by sending data payload as broadcast packets when no route information is available. Thus, data can be delivered without the cost of reactive signalling latency. In this paper we explore the capabilities of a slightly enhanced/adapted ICRP, tailored to the ice monitoring application. By simulations and experiments at sea it is demonstrated that the protocol performs well and can manage the applications high traffic load - this provided that the point-to-point links pro...

  18. FRP/steel composite damage acoustic emission monitoring and analysis

    Science.gov (United States)

    Li, Dongsheng; Chen, Zhi

    2015-04-01

    FRP is a new material with good mechanical properties, such as high strength of extension, low density, good corrosion resistance and anti-fatigue. FRP and steel composite has gotten a wide range of applications in civil engineering because of its good performance. As the FRP/steel composite get more and more widely used, the monitor of its damage is also getting more important. To monitor this composite, acoustic emission (AE) is a good choice. In this study, we prepare four identical specimens to conduct our test. During the testing process, the AE character parameters and mechanics properties were obtained. Damaged properties of FRP/steel composite were analyzed through acoustic emission (AE) signals. By the growing trend of AE accumulated energy, the severity of the damage made on FRP/steel composite was estimated. The AE sentry function has been successfully used to study damage progression and fracture emerge release rate of composite laminates. This technique combines the cumulative AE energy with strain energy of the material rather than analyzes the AE information and mechanical separately.

  19. Tools for automated acoustic monitoring within the R package monitoR

    DEFF Research Database (Denmark)

    Katz, Jonathan; Hafner, Sasha D.; Donovan, Therese

    2016-01-01

    The R package monitoR contains tools for managing an acoustic-monitoring program including survey metadata, template creation and manipulation, automated detection and results management. These tools are scalable for use with small projects as well as larger long-term projects and those...... with expansive spatial extents. Here, we describe typical workflow when using the tools in monitoR. Typical workflow utilizes a generic sequence of functions, with the option for either binary point matching or spectrogram cross-correlation detectors....

  20. Tools for automated acoustic monitoring within the R package monitoR

    Science.gov (United States)

    Katz, Jonathan; Hafner, Sasha D.; Donovan, Therese

    2016-01-01

    The R package monitoR contains tools for managing an acoustic-monitoring program including survey metadata, template creation and manipulation, automated detection and results management. These tools are scalable for use with small projects as well as larger long-term projects and those with expansive spatial extents. Here, we describe typical workflow when using the tools in monitoR. Typical workflow utilizes a generic sequence of functions, with the option for either binary point matching or spectrogram cross-correlation detectors.

  1. Fatigue crack monitoring with coupled piezoelectric film acoustic emission sensors

    Science.gov (United States)

    Zhou, Changjiang

    Fatigue-induced cracking is a commonly seen problem in civil infrastructures reaching their original design life. A number of high-profile accidents have been reported in the past that involved fatigue damage in structures. Such incidences often happen without prior warnings due to lack of proper crack monitoring technique. In order to detect and monitor the fatigue crack, acoustic emission (AE) technique, has been receiving growing interests recently. AE can provide continuous and real-time monitoring data on damage progression in structures. Piezoelectric film AE sensor measures stress-wave induced strain in ultrasonic frequency range and its feasibility for AE signal monitoring has been demonstrated recently. However, extensive work in AE monitoring system development based on piezoelectric film AE sensor and sensor characterization on full-scale structures with fatigue cracks, have not been done. A lack of theoretical formulations for understanding the AE signals also hinders the use of piezoelectric film AE sensors. Additionally, crack detection and source localization with AE signals is a very important area yet to be explored for this new type of AE sensor. This dissertation presents the results of both analytical and experimental study on the signal characteristics of surface stress-wave induced AE strain signals measured by piezoelectric film AE sensors in near-field and an AE source localization method based on sensor couple theory. Based on moment tensor theory, generalized expression for AE strain signal is formulated. A special case involving the response of piezoelectric film AE sensor to surface load is also studied, which could potentially be used for sensor calibration of this type of sensor. A new concept of sensor couple theory based AE source localization technique is proposed and validated with both simulated and experimental data from fatigue test and field monitoring. Two series of fatigue tests were conducted to perform fatigue crack

  2. Passive Autonomous Acoustic Monitoring of Marine Mammals: System Development Using Seaglider (Trademark)

    Science.gov (United States)

    2015-01-30

    DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Passive Autonomous Acoustic Monitoring of Marine Mammals...System Development Using Seaglider Final Report 30 January 2015 Neil M. Bogue Applied Physics Laboratory University of Washington Box ...award as part of the Office of Naval Research’s (ONR) Passive Autonomous Acoustic Monitoring (PAAM) program. The initial long-term goals of the PAAM

  3. Using Acoustic Tomography to Monitor Deep Ocean Currents in the Eastern Gulf of Mexico

    Science.gov (United States)

    2010-06-01

    Toward the improved prediction and monitoring of deep-water currents and eddies in the Gulf of Mexico , the Gulf Eddy Monitoring System group (GEMS...proposes that a network of acoustic transmitter receiver pairs be deployed in the northeastern Gulf of Mexico . Acoustic travel times are inverted to

  4. Operational Performance Analysis of Passive Acoustic Monitoring for Killer Whales

    Energy Technology Data Exchange (ETDEWEB)

    Matzner, Shari; Fu, Tao; Ren, Huiying; Deng, Zhiqun; Sun, Yannan; Carlson, Thomas J.

    2011-09-30

    For the planned tidal turbine site in Puget Sound, WA, the main concern is to protect Southern Resident Killer Whales (SRKW) due to their Endangered Species Act status. A passive acoustic monitoring system is proposed because the whales emit vocalizations that can be detected by a passive system. The algorithm for detection is implemented in two stages. The first stage is an energy detector designed to detect candidate signals. The second stage is a spectral classifier that is designed to reduce false alarms. The evaluation presented here of the detection algorithm incorporates behavioral models of the species of interest, environmental models of noise levels and potential false alarm sources to provide a realistic characterization of expected operational performance.

  5. Surface Acoustic Wave (SAW Resonators for Monitoring Conditioning Film Formation

    Directory of Open Access Journals (Sweden)

    Siegfried Hohmann

    2015-05-01

    Full Text Available We propose surface acoustic wave (SAW resonators as a complementary tool for conditioning film monitoring. Conditioning films are formed by adsorption of inorganic and organic substances on a substrate the moment this substrate comes into contact with a liquid phase. In the case of implant insertion, for instance, initial protein adsorption is required to start wound healing, but it will also trigger immune reactions leading to inflammatory responses. The control of the initial protein adsorption would allow to promote the healing process and to suppress adverse immune reactions. Methods to investigate these adsorption processes are available, but it remains difficult to translate measurement results into actual protein binding events. Biosensor transducers allow user-friendly investigation of protein adsorption on different surfaces. The combination of several transduction principles leads to complementary results, allowing a more comprehensive characterization of the adsorbing layer. We introduce SAW resonators as a novel complementary tool for time-resolved conditioning film monitoring. SAW resonators were coated with polymers. The adsorption of the plasma proteins human serum albumin (HSA and fibrinogen onto the polymer-coated surfaces were monitored. Frequency results were compared with quartz crystal microbalance (QCM sensor measurements, which confirmed the suitability of the SAW resonators for this application.

  6. Surface Acoustic Wave (SAW) Resonators for Monitoring Conditioning Film Formation.

    Science.gov (United States)

    Hohmann, Siegfried; Kögel, Svea; Brunner, Yvonne; Schmieg, Barbara; Ewald, Christina; Kirschhöfer, Frank; Brenner-Weiß, Gerald; Länge, Kerstin

    2015-05-21

    We propose surface acoustic wave (SAW) resonators as a complementary tool for conditioning film monitoring. Conditioning films are formed by adsorption of inorganic and organic substances on a substrate the moment this substrate comes into contact with a liquid phase. In the case of implant insertion, for instance, initial protein adsorption is required to start wound healing, but it will also trigger immune reactions leading to inflammatory responses. The control of the initial protein adsorption would allow to promote the healing process and to suppress adverse immune reactions. Methods to investigate these adsorption processes are available, but it remains difficult to translate measurement results into actual protein binding events. Biosensor transducers allow user-friendly investigation of protein adsorption on different surfaces. The combination of several transduction principles leads to complementary results, allowing a more comprehensive characterization of the adsorbing layer. We introduce SAW resonators as a novel complementary tool for time-resolved conditioning film monitoring. SAW resonators were coated with polymers. The adsorption of the plasma proteins human serum albumin (HSA) and fibrinogen onto the polymer-coated surfaces were monitored. Frequency results were compared with quartz crystal microbalance (QCM) sensor measurements, which confirmed the suitability of the SAW resonators for this application.

  7. Progress towards Acoustic Suspended Sediment Transport Monitoring: Fraser River, BC

    Science.gov (United States)

    Attard, M. E.; Venditti, J. G.; Church, M. A.; Kostaschuk, R. A.

    2011-12-01

    Our ability to predict the timing and quantity of suspended sediment transport is limited because fine sand, silt and clay delivery are supply limited, requiring empirical modeling approaches of limited temporal stability. A solution is the development of continuous monitoring techniques capable of tracking sediment concentrations and grain-size. Here we examine sediment delivery from upstream sources to the lower Fraser River. The sediment budget of the lower Fraser River provides a long-term perspective of the net changes in the channels and in sediment delivery to Fraser Delta. The budget is based on historical sediment rating curves developed from data collected from 1965-1986 by the Water Survey of Canada. We explore the possibility of re-establishing the sediment-monitoring program using hydro-acoustics by evaluating the use of a 300 kHz side-looking acoustic Doppler current profiler (aDcp), mounted just downstream of the sand-gravel transition at Mission, for continuous measurement of suspended sediment transport. Complementary field observations include conventional bottle sampling with a P-63 sampler, vertical profiles with a downward-looking 600 kHz aDcp, and 1200 kHz aDcp discharge measurements. We have successfully completed calibration of the downward-looking aDcp with the P-63 samples; the side-looking aDcp signals remain under investigation. A comparison of several methods for obtaining total sediment flux indicates that suspended sediment concentration (SSC) closely follows discharge through the freshet and peaks in total SSC and sand SSC coincide with peak measurements of discharge. Low flows are dominated by fine sediment and grain size increases with higher flows. This research assesses several techniques for obtaining sediment flux and contributes to the understanding of sediment delivery to sand-bedded portions of the river.

  8. Monitoring polymer properties using shear horizontal surface acoustic waves.

    Science.gov (United States)

    Gallimore, Dana Y; Millard, Paul J; Pereira da Cunha, Mauricio

    2009-10-01

    Real-time, nondestructive methods for monitoring polymer film properties are increasingly important in the development and fabrication of modern polymer-containing products. Online testing of industrial polymer films during preparation and conditioning is required to minimize material and energy consumption, improve the product quality, increase the production rate, and reduce the number of product rejects. It is well-known that shear horizontal surface acoustic wave (SH-SAW) propagation is sensitive to mass changes as well as to the mechanical properties of attached materials. In this work, the SH-SAW was used to monitor polymer property changes primarily dictated by variations in the viscoelasticity. The viscoelastic properties of a negative photoresist film were monitored throughout the ultraviolet (UV) light-induced polymer cross-linking process using SH-SAW delay line devices. Changes in the polymer film mass and viscoelasticity caused by UV exposure produced variations in the phase velocity and attenuation of the SH-SAW propagating in the structure. Based on measured polymer-coated delay line scattering transmission responses (S(21)) and the measured polymer layer thickness and density, the viscoelastic constants c(44) and eta(44) were extracted. The polymer thickness was found to decrease 0.6% during UV curing, while variations in the polymer density were determined to be insignificant. Changes of 6% in c(44) and 22% in eta(44) during the cross-linking process were observed, showing the sensitivity of the SH-SAW phase velocity and attenuation to changes in the polymer film viscoelasticity. These results indicate the potential for SH-SAW devices as online monitoring sensors for polymer film processing.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-01-15

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

  10. Distributed acoustic fibre optic sensors for condition monitoring of pipelines

    Science.gov (United States)

    Hussels, Maria-Teresa; Chruscicki, Sebastian; Habib, Abdelkarim; Krebber, Katerina

    2016-05-01

    Industrial piping systems are particularly relevant to public safety and the continuous availability of infrastructure. However, condition monitoring systems based on many discrete sensors are generally not well-suited for widespread piping systems due to considerable installation effort, while use of distributed fibre-optic sensors would reduce this effort to a minimum. Specifically distributed acoustic sensing (DAS) is employed for detection of third-party threats and leaks in oil and gas pipelines in recent years and can in principle also be applied to industrial plants. Further possible detection routes amenable by DAS that could identify damage prior to emission of medium are subject of a current project at BAM, which aims at qualifying distributed fibre optic methods such as DAS as a means for spatially continuous monitoring of industrial piping systems. Here, first tests on a short pipe are presented, where optical fibres were applied directly to the surface. An artificial signal was used to define suitable parameters of the measurement system and compare different ways of applying the sensor.

  11. Structural health condition monitoring of rails using acoustic emission techniques

    Science.gov (United States)

    Yilmazer, Pinar

    In-service rails can develop several types of structural defects due to fatigue and wear caused by rolling stock passing over them. Most rail defects will develop gradually over time thus permitting inspection engineers to detect them in time before final failure occurs. In the UK, certain types of severe rail defects such as tache ovales, require the fitting of emergency clamps and the imposing of an Emergency Speed Restriction (ESR) until the defects are removed. Acoustic emission (AE) techniques can be applied for the detection and continuous monitoring of defect growth therefore removing the need of imposing strict ESRs. The work reported herewith aims to develop a sound methodology for the application of AE in order to detect and subsequently monitor damage evolution in rails. To validate the potential of the AE technique, tests have been carried out under laboratory conditions on three and four-point bending samples manufactured from 260 grade rail steel. Further tests, simulating the background noise conditions caused by passing rolling stock have been carried out using special experimental setups. The crack growth events have been simulated using a pencil tip break..

  12. Early corrosion monitoring of prestressed concrete piles using acoustic emission

    Science.gov (United States)

    Vélez, William; Matta, Fabio; Ziehl, Paul H.

    2013-04-01

    The depassivation and corrosion of bonded prestressing steel strands in concrete bridge members may lead to major damage or collapse before visual inspections uncover evident signs of damage, and well before the end of the design life. Recognizing corrosion in its early stage is desirable to plan and prioritize remediation strategies. The Acoustic Emission (AE) technique is a rational means to develop structural health monitoring and prognosis systems for the early detection and location of corrosion in concrete. Compelling features are the sensitivity to events related to micro- and macrodamage, non-intrusiveness, and suitability for remote and wireless applications. There is little understanding of the correlation between AE and the morphology and extent of early damage on the steel surface. In this paper, the evidence collected from prestressed concrete (PC) specimens that are exposed to salt water is discussed vis-à-vis AE data from continuous monitoring. The specimens consist of PC strips that are subjected to wet/dry salt water cycles, representing portions of bridge piles that are exposed to tidal action. Evidence collected from the specimens includes: (a) values of half-cell potential and linear polarization resistance to recognize active corrosion in its early stage; and (b) scanning electron microscopy micrographs of steel areas from two specimens that were decommissioned once the electrochemical measurements indicated a high probability of active corrosion. These results are used to evaluate the AE activity resulting from early corrosion.

  13. Embedded and conventional ultrasonic sensors for monitoring acoustic emission during thermal fatigue

    Science.gov (United States)

    Trujillo, Blaine; Zagrai, Andrei

    2016-04-01

    Acoustic emission is widely used for monitoring pressure vessels, pipes, critical infrastructure, as well as land, sea and air vehicles. It is one of dominant approaches to explore material degradation under fatigue and events leading to material fracture. Addressing a recent interest in structural health monitoring of space vehicles, a need has emerged to evaluate material deterioration due to thermal fatigue during spacecraft atmospheric reentry. Thermal fatigue experiments were conducted, in which aluminum plates were subjected to localized heating and acoustic emission was monitoring by embedded and conventional acoustic emission sensors positioned at various distances from a heat source. At the same time, surface temperature of aluminum plates was monitored using an IR camera. Acoustic emission counts collected by embedded sensors were compared to counts measured with conventional acoustic emission sensors. Both types of sensors show noticeable increase of acoustic emission activity as localized heating source was applied to aluminum plates. Experimental data demonstrate correlation between temperature increase on the surface of the plates and increase in measured acoustic emission activity. It is concluded that under particular conditions, embedded piezoelectric wafer active sensors can be used for acoustic emission monitoring of thermally-induced structural degradation.

  14. 2006 progress report on acoustic and visual monitoring for cetaceans along the outer Washington Coast

    OpenAIRE

    Oleson, Erin M.; Hildebrand, John A.; Calambokidis, John; Schorr, Greg; Falcone, Erin

    2007-01-01

    An acoustic and visual monitoring effort for cetaceans was initiated within the boundaries of the proposed expansion area for the Quinault Underwater Tracking Range in July 2004. Acoustic data collection consisted of recordings at a site on the continental shelf to the west of Cape Elizabeth and another in deep water within Quinault Canyon. An analysis plan for acoustic data is included. Results for 32 visual surveys are presented as tables and charts for pinnipeds, dolphins, porpoises, an...

  15. Diagnostic System of Wireless Acoustic Emission Signal Transfer for Monitoring Oil-and-Gas Facilities

    Directory of Open Access Journals (Sweden)

    Skalsky, V.R.

    2016-01-01

    Full Text Available The structure of diagnostic 8-channel system for wireless transfer of acoustic emission information during monitoring the objects of long operation is revealed. The results of the development of algorithmic software for hardware system and personal computer, which performs system control and post-processing of acoustic emission information. are presented. The basic specifications of the system are described.

  16. Acoustic Emissions (AE) Electrical Systems' Health Monitoring Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Acoustic Emissions (AE) are associated with physical events, such as thermal activity, dielectric breakdown, discharge inception, as well as crack nucleation and...

  17. Passive acoustic monitoring of Cook Inlet beluga whales (Delphinapterus leucas).

    Science.gov (United States)

    Lammers, Marc O; Castellote, Manuel; Small, Robert J; Atkinson, Shannon; Jenniges, Justin; Rosinski, Anne; Oswald, Julie N; Garner, Chris

    2013-09-01

    The endangered beluga whale (Delphinapterus leucas) population in Cook Inlet, AK faces threats from a variety of anthropogenic factors, including coastal development, oil and gas exploration, vessel traffic, and military activities. To address existing gaps in understanding about the occurrence of belugas in Cook Inlet, a project was developed to use passive acoustic monitoring to document the year-round distribution of belugas, as well as killer whales (Orcinus orca), which prey on belugas. Beginning in June 2009, ten moorings were deployed throughout the Inlet and refurbished every two to eight months. Despite challenging conditions consisting of strong tidal currents carrying debris and seasonal ice cover, 83% of mooring deployments were successfully recovered. Noise from water flow, vessel traffic, and/or industrial activities was present at several sites, potentially masking some signals. However, belugas were successfully detected at multiple locations. Detections were relatively common in the upper inlet and less common or absent at middle and lower inlet locations. Killer whale signals were also recorded. Some seasonal variability in the occurrence of both belugas and killer whales was evident.

  18. Acoustical method of whole-body hydration status monitoring

    Science.gov (United States)

    Sarvazyan, A. P.; Tsyuryupa, S. N.; Calhoun, M.; Utter, A.

    2016-07-01

    An acoustical handheld hydration monitor (HM) for assessing the water balance of the human body was developed. Dehydration is a critical public health problem. Many elderly over age of 65 are particularly vulnerable as are infants and young children. Given that dehydration is both preventable and reversible, the need for an easy-to-perform method for the detection of water imbalance is of the utmost clinical importance. The HM is based on an experimental fact that ultrasound velocity in muscle is a linear function of water content and can be referenced to the hydration status of the body. Studies on the validity of HM for the assessment of whole-body hydration status were conducted in the Appalachian State University, USA, on healthy young adults and on elderly subjects residing at an assisted living facility. The HM was able to track changes in total body water during periods of acute dehydration and rehydration in athletes and day-to-day and diurnal variability of hydration in elderly. Results of human studies indicate that HM has a potential to become an efficient tool for detecting abnormal changes in the body hydration status.

  19. Intra—Operative Facial Nerve Monitoring in Acoustic Neurinoma Surgery

    Institute of Scientific and Technical Information of China (English)

    YANGZhengming; ZHANGZhifeng; 等

    2002-01-01

    Objective To determine the method and significance of facial nerve preservation during acoustic neurinoma surgery by intra-operative facial nerve monitoring(IFNM).Methods 62 patients were randomly assigned to the IFNM or the control group.Facial nerve function(FNF)was assessed by a modified House-Brackmann grading(HB)before the operation,10 days and every two months after surgery and com,pared between the two groups. Results Ten days after surgery,26/32 patients in the IFNM group and 15/30 patients in the control group had FNF HB grade,Ⅰ-Ⅲ;FNF HB gradeⅣ-Ⅴ was prestent in 6/32 in the IFNM group and 15/30 in the control group.During follow-up,29/32 patients in the IFNM group and 20/20 patients in the control group had FNF HB gradeⅠ-Ⅲ;FNF HB gradeⅣ-Ⅴ was present in 3/32 in the IFNM group and 10/30 in the control group.All differnces were statistcally significant.Conclusion IFNM significantly improved anatomic and functional facial nerve preservation as well as the quality of life.

  20. Fetal acoustic stimulation test for early intrapartum fetal monitoring.

    Science.gov (United States)

    Goonewardene, M; Hanwellage, K

    2011-03-01

    The fetal acoustic stimulation test (FAST) is a simple cost effective screening test for antenatal fetal monitoring. The aim of the study was to evaluate the FAST as a screening test for early intrapartum fetal well being. An initial non stress test (NST) followed by a FAST using corometric model 146 was carried out in 486 participants in early labour with uncomplicated singleton pregnancies and > 32 weeks gestation. A repeat NST was recorded in the participants who had an initial non reactive NST. The results of the NST and FAST were compared with fetal outcome. Maternal perception of fetal movements after FAST, results of NST before and after FAST, and the babies' 5 minute APGAR scores were measured. Of the 486 participants 413 (85%) noticed fetal movements after FAST. Initial NST was non reactive in 203 (42%) but 149 (31%) became reactive after FAST. Compared to the NST, FAST had a better sensitivity (97% vs 62%, p fetal well being in early labour. It complements the NST and is better than the NST alone.

  1. Monitoring corrosion in prestressed concrete beams using acoustic emission technique

    Science.gov (United States)

    ElBatanouny, Mohamed K.; Mangual, Jesé; Vélez, William; Ziehl, Paul H.; Matta, Fabio; González, Miguel

    2012-04-01

    Early detection of corrosion can help reduce the cost of maintenance and extend the service life of structures. Acoustic emission (AE) sensing has proven to be a promising method for early detection of corrosion in reinforced concrete members. A test program is presented composed of four medium-scale prestressed concrete T-beams. Three of the beams have a length of 16 ft. 4 in. (4.98 m), and one is 9 ft. 8 in. (2.95 m). In order to corrode the specimens a 3% NaCl solution was prepared, which is representative of sea salt concentration. The beams were subjected to wet-dry cycles to accelerate the corrosion process. Two of the specimens were pre-cracked prior to conditioning in order to examine the effect of crack presence. AE data was recorded continuously while half-cell potential measurements and corrosion rate by Linear Polarization Resistance (LPR) were measured daily. Corrosion current was also being acquired constantly to monitor any change in the concrete resistivity. Results indicate that the onset of corrosion may be identified using AE features, and were corroborated with measurements obtained from electrochemical techniques. Corroded areas were located using source triangulation. The results indicate that cracked specimens showed corrosion activity prior to un-cracked specimens and experienced higher corrosion rates. The level of corrosion was determined using corrosion rate results. Intensity analysis was used to link the corrosion rate and level to AE data.

  2. Time Reversal Acoustic Structural Health Monitoring Using Array of Embedded Sensors Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Time Reversal Acoustic (TRA) structural health monitoring with an embedded sensor array represents a new approach to in-situ nondestructive evaluation of air-space...

  3. Acoustic Emission Based In-process Monitoring in Robot Assisted Polishing

    DEFF Research Database (Denmark)

    Pilny, Lukas; Bissacco, Giuliano; De Chiffre, Leonardo

    The applicability of acoustic emission (AE) measurements for in-process monitoring in the Robot Assisted Polishing (RAP) process was investigated. Surface roughness measurements require interruption of the process, proper surface cleaning and measurements that sometimes necessitate removal of the...

  4. Automatic classification of urban traffic noise onboard an acoustic monitoring system

    NARCIS (Netherlands)

    Wessels, P.W.; Zon, A.T. van; Basten, T.G.H.

    2013-01-01

    Recent developments in acoustic monitoring systems make it possible to measure complex noise situations, like urban traffic noise, continuously. Monitoring provides more insight in the noise situation, from which more specific and (cost) effective measures can be taken. Monitoring also allows direct

  5. Automatic classification of urban traffic noise onboard an acoustic monitoring system

    NARCIS (Netherlands)

    Wessels, P.W.; Zon, A.T. van; Basten, T.G.H.

    2013-01-01

    Recent developments in acoustic monitoring systems make it possible to measure complex noise situations, like urban traffic noise, continuously. Monitoring provides more insight in the noise situation, from which more specific and (cost) effective measures can be taken. Monitoring also allows direct

  6. Surface Acoustic Wave Monitor for Deposition and Analysis of Ultra-Thin Films

    Science.gov (United States)

    Hines, Jacqueline H. (Inventor)

    2015-01-01

    A surface acoustic wave (SAW) based thin film deposition monitor device and system for monitoring the deposition of ultra-thin films and nanomaterials and the analysis thereof is characterized by acoustic wave device embodiments that include differential delay line device designs, and which can optionally have integral reference devices fabricated on the same substrate as the sensing device, or on a separate device in thermal contact with the film monitoring/analysis device, in order to provide inherently temperature compensated measurements. These deposition monitor and analysis devices can include inherent temperature compensation, higher sensitivity to surface interactions than quartz crystal microbalance (QCM) devices, and the ability to operate at extreme temperatures.

  7. The use of acoustic emission for bearing condition monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Lees, A W; Quiney, Z [Swansea University, Singleton Park, Swansea, SA2 8PP (United Kingdom); Ganji, A; Murray, B, E-mail: a.w.lees@swansea.ac.uk, E-mail: z.quiney.294103@swansea.ac.uk, E-mail: ali.ganji@skf.com [SKF Engineering and Research Centre, Kelvinbaan 16, 3439 MT Nieuwegein (Netherlands)

    2011-07-19

    This paper reports research currently in progress at Swansea University in collaboration with SKF Engineering and Research Centre as part of a continuing investigation into high frequency Acoustic Emission. The primary concerns are experimentally producing subsurface cracks, the type of which would occur in a service failure of a ball bearing, within a steel ball and to closely monitor the properties of this AE from crack initiation to the formation of a ball on the ball surface. It is worth noting that there is evidence that the frequency content of the AE changes during this period, although this has yet to be proved consistent or even fully explained. Conclusive evidence could lead to a system which detects such cracks in a bearing operating in real life conditions, advantageous for many reasons including safety, downtime and maintenance and associated costs. The results from two experimental procedures are presented, one of which loads a single ball held stationary in a test rig to induce subsurface cracks, which are in turn detected by a pair of broadband AE sensors and recorded via a Labview based software system. This approach not only allows detailed analysis of the AE waveforms but also approximate AE source location from the time difference between two sensors. The second experimental procedure details an adaptation of a four-ball lubricant tester in an attempt to produce naturally occurring subsurface cracks from rolling contact whilst minimising the AE arising from surface wear. This thought behind this experiment is reinforced with 3D computational modelling of the rotating system.

  8. Aespoe Pillar Stability Experiment. Acoustic emission and ultrasonic monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Haycox, Jon; Pettitt, Will; Young, R. Paul [Applied Seismology Consultants Ltd., Shrewsbury (United Kingdom)

    2005-12-15

    This report describes the results from acoustic emission (AE) and ultrasonic monitoring of the Aespoe Pillar Stability Experiment (APSE) at SKB's Hard Rock Laboratory (HRL), Sweden. The APSE is being undertaken to demonstrate the current capability to predict spalling in a fractured rock mass using numerical modelling techniques, and to demonstrate the effect of backfill and confining pressure on the propagation of micro-cracks in rock adjacent to deposition holes within a repository. An ultrasonic acquisition system has provided acoustic emission and ultrasonic survey monitoring throughout the various phases of the experiment. Results from the entire data set are provided with this document so that they can be effectively compared to several numerical modelling studies, and to mechanical and thermal measurements conducted around the pillar volume, in an 'integrated analysis' performed by SKB staff. This document provides an in-depth summary of the AE and ultrasonic survey results for future reference. The pillar has been produced by excavating two 1.8 m diameter deposition holes 1 m apart. These were bored in 0.8 m steps using a Tunnel Boring Machine specially adapted for vertical drilling. The first deposition hole was drilled in December 2003. Preceding this a period of background monitoring was performed so as to obtain a datum for the results. The hole was then confined to 0.7 MPa internal over pressure using a specially designed water-filled bladder. The second deposition hole was excavated in March 2004. Heating of the pillar was performed over a two month period between ending in July 2004, when the confined deposition hole was slowly depressurised. Immediately after depressurisation the pillar was allowed to cool with cessation of monitoring occurring a month later. A total of 36,676 AE triggers were recorded over the reporting period between 13th October 2003 and 14th July 2004. Of these 15,198 have produced AE locations. The AE data set

  9. Aespoe Pillar Stability Experiment. Acoustic emission and ultrasonic monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Haycox, Jon; Pettitt, Will; Young, R. Paul [Applied Seismology Consultants Ltd., Shrewsbury (United Kingdom)

    2005-12-15

    This report describes the results from acoustic emission (AE) and ultrasonic monitoring of the Aespoe Pillar Stability Experiment (APSE) at SKB's Hard Rock Laboratory (HRL), Sweden. The APSE is being undertaken to demonstrate the current capability to predict spalling in a fractured rock mass using numerical modelling techniques, and to demonstrate the effect of backfill and confining pressure on the propagation of micro-cracks in rock adjacent to deposition holes within a repository. An ultrasonic acquisition system has provided acoustic emission and ultrasonic survey monitoring throughout the various phases of the experiment. Results from the entire data set are provided with this document so that they can be effectively compared to several numerical modelling studies, and to mechanical and thermal measurements conducted around the pillar volume, in an 'integrated analysis' performed by SKB staff. This document provides an in-depth summary of the AE and ultrasonic survey results for future reference. The pillar has been produced by excavating two 1.8 m diameter deposition holes 1 m apart. These were bored in 0.8 m steps using a Tunnel Boring Machine specially adapted for vertical drilling. The first deposition hole was drilled in December 2003. Preceding this a period of background monitoring was performed so as to obtain a datum for the results. The hole was then confined to 0.7 MPa internal over pressure using a specially designed water-filled bladder. The second deposition hole was excavated in March 2004. Heating of the pillar was performed over a two month period between ending in July 2004, when the confined deposition hole was slowly depressurised. Immediately after depressurisation the pillar was allowed to cool with cessation of monitoring occurring a month later. A total of 36,676 AE triggers were recorded over the reporting period between 13th October 2003 and 14th July 2004. Of these 15,198 have produced AE locations. The AE data set

  10. Remote acoustic monitoring of North Atlantic right whales (Eubalaena glacialis reveals seasonal and diel variations in acoustic behavior.

    Directory of Open Access Journals (Sweden)

    Leanna P Matthews

    Full Text Available Remote acoustic monitoring is a non-invasive tool that can be used to study the distribution, behavior, and habitat use of sound-producing species. The North Atlantic right whale (Eubalaena glacialis is an endangered baleen whale species that produces a variety of stereotyped acoustic signals. One of these signals, the "gunshot" sound, has only been recorded from adult male North Atlantic right whales and is thought to function for reproduction, either as reproductive advertisement for females or as an agonistic signal toward other males. This study uses remote acoustic monitoring to analyze the presence of gunshots over a two-year period at two sites on the Scotian Shelf to determine if there is evidence that North Atlantic right whales may use these locations for breeding activities. Seasonal analyses at both locations indicate that gunshot sound production is highly seasonal, with an increase in the autumn. One site, Roseway West, had significantly more gunshot sounds overall and exhibited a clear diel trend in production of these signals at night. The other site, Emerald South, also showed a seasonal increase in gunshot production during the autumn, but did not show any significant diel trend. This difference in gunshot signal production at the two sites indicates variation either in the number or the behavior of whales at each location. The timing of the observed seasonal increase in gunshot sound production is consistent with the current understanding of the right whale breeding season, and our results demonstrate that detection of gunshots with remote acoustic monitoring can be a reliable way to track shifts in distribution and changes in acoustic behavior including possible mating activities.

  11. Remote acoustic monitoring of North Atlantic right whales (Eubalaena glacialis) reveals seasonal and diel variations in acoustic behavior.

    Science.gov (United States)

    Matthews, Leanna P; McCordic, Jessica A; Parks, Susan E

    2014-01-01

    Remote acoustic monitoring is a non-invasive tool that can be used to study the distribution, behavior, and habitat use of sound-producing species. The North Atlantic right whale (Eubalaena glacialis) is an endangered baleen whale species that produces a variety of stereotyped acoustic signals. One of these signals, the "gunshot" sound, has only been recorded from adult male North Atlantic right whales and is thought to function for reproduction, either as reproductive advertisement for females or as an agonistic signal toward other males. This study uses remote acoustic monitoring to analyze the presence of gunshots over a two-year period at two sites on the Scotian Shelf to determine if there is evidence that North Atlantic right whales may use these locations for breeding activities. Seasonal analyses at both locations indicate that gunshot sound production is highly seasonal, with an increase in the autumn. One site, Roseway West, had significantly more gunshot sounds overall and exhibited a clear diel trend in production of these signals at night. The other site, Emerald South, also showed a seasonal increase in gunshot production during the autumn, but did not show any significant diel trend. This difference in gunshot signal production at the two sites indicates variation either in the number or the behavior of whales at each location. The timing of the observed seasonal increase in gunshot sound production is consistent with the current understanding of the right whale breeding season, and our results demonstrate that detection of gunshots with remote acoustic monitoring can be a reliable way to track shifts in distribution and changes in acoustic behavior including possible mating activities.

  12. Assessment of error rates in acoustic monitoring with the R package monitoR

    Science.gov (United States)

    Katz, Jonathan; Hafner, Sasha D.; Donovan, Therese

    2016-01-01

    Detecting population-scale reactions to climate change and land-use change may require monitoring many sites for many years, a process that is suited for an automated system. We developed and tested monitoR, an R package for long-term, multi-taxa acoustic monitoring programs. We tested monitoR with two northeastern songbird species: black-throated green warbler (Setophaga virens) and ovenbird (Seiurus aurocapilla). We compared detection results from monitoR in 52 10-minute surveys recorded at 10 sites in Vermont and New York, USA to a subset of songs identified by a human that were of a single song type and had visually identifiable spectrograms (e.g. a signal:noise ratio of at least 10 dB: 166 out of 439 total songs for black-throated green warbler, 502 out of 990 total songs for ovenbird). monitoR’s automated detection process uses a ‘score cutoff’, which is the minimum match needed for an unknown event to be considered a detection and results in a true positive, true negative, false positive or false negative detection. At the chosen score cut-offs, monitoR correctly identified presence for black-throated green warbler and ovenbird in 64% and 72% of the 52 surveys using binary point matching, respectively, and 73% and 72% of the 52 surveys using spectrogram cross-correlation, respectively. Of individual songs, 72% of black-throated green warbler songs and 62% of ovenbird songs were identified by binary point matching. Spectrogram cross-correlation identified 83% of black-throated green warbler songs and 66% of ovenbird songs. False positive rates were  for song event detection.

  13. Condition monitoring of industrial infrastructures using distributed fibre optic acoustic sensors

    Science.gov (United States)

    Hicke, Konstantin; Hussels, Maria-Teresa; Eisermann, René; Chruscicki, Sebastian; Krebber, Katerina

    2017-04-01

    Distributed fibre optic acoustic sensing (DAS) can serve as an excellent tool for real-time condition monitoring of a variety of industrial and civil infrastructures. In this paper, we portray a subset of our current research activities investigating the usability of DAS based on coherent optical time-domain reflectometry (C-OTDR) for innovative and demanding condition monitoring applications. Specifically, our application-oriented research presented here aims at acoustic and vibrational condition monitoring of pipelines and piping systems, of rollers in industrial heavy-duty conveyor belt systems and of extensive submarine power cable installations, respectively.

  14. Acoustic Emission Behavior of Early Age Concrete Monitored by Embedded Sensors

    Directory of Open Access Journals (Sweden)

    Lei Qin

    2014-10-01

    Full Text Available Acoustic emission (AE is capable of monitoring the cracking activities inside materials. In this study, embedded sensors were employed to monitor the AE behavior of early age concrete. Type 1–3 cement-based piezoelectric composites, which had lower mechanical quality factor and acoustic impedance, were fabricated and used to make sensors. Sensors made of the composites illustrated broadband frequency response. In a laboratory, the cracking of early age concrete was monitored to recognize different hydration stages. The sensors were also embedded in a mass concrete foundation to localize the temperature gradient cracks.

  15. Improving the Navys Passive Underwater Acoustic Monitoring of Marine Mammal Populations

    Science.gov (United States)

    2015-09-30

    Monitoring of Marine Mammal Populations Gerald L. D’Spain Marine Physical Laboratory Scripps Institution of Oceanography 291 Rosecrans Street... mammal populations. A major focus in this project is on further enhancing the ability to estimate environmentally-calibrated calling density (calls per... mammal species using passive acoustic monitoring, with application to obtaining density estimates of transiting humpback whale populations in the

  16. California Current Monitoring Using the NPS Ocean Acoustic Observatory

    Science.gov (United States)

    2016-06-07

    acoustic measurements generated by this project can be used to validate and calibrate ocean forecast model for the region. The data can also be... Innovative Coastal Observing Network (ICON). ICON studies the ocean processes in the Monterey Bay area which is influenced by the California Current

  17. Acoustic monitoring of terrorist intrusion in a drinking water network

    NARCIS (Netherlands)

    Quesson, B.A.J.; Sheldon-Robert, M.K.; Vloerbergh, I.N.; Vreeburg, J.H.G.

    2009-01-01

    In collaboration with Kiwa Water Research, TNO (Netherlands Organisation for Applied Scientific Research) has investigated the possibilities to detect and classify aberrant sounds in water networks, using acoustic sensors. Amongst the sources of such sounds are pumps, drills, mechanical impacts, whi

  18. Improvements to Passive Acoustic Tracking Methods for Marine Mammal Monitoring

    Science.gov (United States)

    2014-09-30

    in Zimmer (Eq 4.32): () = ()−2() where W(t) is an amplitude weighting function; a hanning window corresponding to the duration...Hildebrand (2004). Waveguide propagation allows range estimates for North Pacific right whales in the Bering Sea. Can. Acoust. 32:146‐ 154. Zimmer W

  19. Monitoring the fractionation of a whey protein isolate during dead-end membrane filtration using fluorescence and chemometric methods.

    Science.gov (United States)

    Elshereef, Rand; Budman, Hector; Moresoli, Christine; Legge, Raymond L

    2010-01-01

    During membrane-based separation of proteins, changes in protein concentration of the permeate and retentate streams occurs over time. The current work proposes a new approach for monitoring the changes in concentrations of proteins in both permeate and retentate by making use of data collected using fluorescence spectroscopy and intrinsic protein fluorescence analyzed by multivariate statistical techniques. Whey protein isolate consists mainly of alpha-lactalbumin (alpha-LA), beta-lactoglobulin (beta-LG), and small proportion of bovine serum albumin (BSA) and was used as a model system in this study. A fiber optic probe (FOP) was used to acquire multiwavelength fluorescence spectra for permeate and retentate streams at different times during UF-based separation of the components from a multicomponent solution. Multivariate regression models were developed for predicting the concentrations of alpha-LA, beta-LG, and BSA by establishing a calibration model between data acquired using the FOP and the corresponding protein concentration levels measured by size-exclusion chromatography. The model was validated using FOP data that were not previously used for calibration of the regression models. This comparison showed that concentrations of alpha-LA, beta-LG, and BSA could be predicted directly from FOP data within reasonable accuracy by making use of multivariate calibration tools. This approach has several attractive features including that it is nondestructive, fast, and relatively simple to perform. This technique has potential practical applications as it could offer the opportunity for in situ monitoring of membrane filtration processes by tracking individual protein transmission and selectivity of fractionation.

  20. Passive acoustic monitoring of bed load discharge in a large gravel bed river

    Science.gov (United States)

    Geay, T.; Belleudy, P.; Gervaise, C.; Habersack, H.; Aigner, J.; Kreisler, A.; Seitz, H.; Laronne, J. B.

    2017-02-01

    Surrogate technologies to monitor bed load discharge have been developed to supplement and ultimately take over traditional direct methods. Our research deals with passive acoustic monitoring of bed load flux using a hydrophone continuously deployed near a river bed. This passive acoustic technology senses any acoustic waves propagated in the river environment and particularly the sound due to interparticle collisions emitted during bed load movement. A data set has been acquired in the large Alpine gravel-bedded Drau River. Analysis of the short-term frequency response of acoustic signals allows us to determine the origin of recorded noises and to consider their frequency variations. Results are compared with ancillary field data of water depth and bed load transport inferred from the signals of a geophone array. Hydrophone and geophone signals are well correlated. Thanks to the large network of deployed geophones, analysis of the spatial resolution of hydrophone measurements shows that the sensor is sensitive to bed load motion not only locally but over distances of 5-10 m (10-20% of river width). Our results are promising in terms of the potential use of hydrophones for monitoring bed load transport in large gravel bed rivers: acoustic signals represent a large river bed area, rather than being local; hydrophones can be installed in large floods; they can be deployed at a low cost and provide continuous monitoring at high temporal resolution.

  1. Thick-film acoustic emission sensors for use in structurally integrated condition-monitoring applications.

    Science.gov (United States)

    Pickwell, Andrew J; Dorey, Robert A; Mba, David

    2011-09-01

    Monitoring the condition of complex engineering structures is an important aspect of modern engineering, eliminating unnecessary work and enabling planned maintenance, preventing failure. Acoustic emissions (AE) testing is one method of implementing continuous nondestructive structural health monitoring. A novel thick-film (17.6 μm) AE sensor is presented. Lead zirconate titanate thick films were fabricated using a powder/sol composite ink deposition technique and mechanically patterned to form a discrete thick-film piezoelectric AE sensor. The thick-film sensor was benchmarked against a commercial AE device and was found to exhibit comparable responses to simulated acoustic emissions.

  2. Common humpback whale (Megaptera novaeangliae) sound types for passive acoustic monitoring.

    Science.gov (United States)

    Stimpert, Alison K; Au, Whitlow W L; Parks, Susan E; Hurst, Thomas; Wiley, David N

    2011-01-01

    Humpback whales (Megaptera novaeangliae) are one of several baleen whale species in the Northwest Atlantic that coexist with vessel traffic and anthropogenic noise. Passive acoustic monitoring strategies can be used in conservation management, but the first step toward understanding the acoustic behavior of a species is a good description of its acoustic repertoire. Digital acoustic tags (DTAGs) were placed on humpback whales in the Stellwagen Bank National Marine Sanctuary to record and describe the non-song sounds being produced in conjunction with foraging activities. Peak frequencies of sounds were generally less than 1 kHz, but ranged as high as 6 kHz, and sounds were generally less than 1 s in duration. Cluster analysis distilled the dataset into eight groups of sounds with similar acoustic properties. The two most stereotyped and distinctive types ("wops" and "grunts") were also identified aurally as candidates for use in passive acoustic monitoring. This identification of two of the most common sound types will be useful for moving forward conservation efforts on this Northwest Atlantic feeding ground.

  3. A novel sensor for monitoring acoustic cavitation. Part II: Prototype performance evaluation.

    Science.gov (United States)

    Zeqiri, Bajram; Lee, Nigel D; Hodnett, Mark; Gélat, Pierre N

    2003-10-01

    This paper describes a series of experimental studies to evaluate the performance of newly developed sensors for monitoring broadband acoustic emissions generated by acoustic cavitation. The prototype sensors are fabricated in the form of hollow, open-ended cylinders, whose inner surface is made from a thin film of piezoelectric polymer acting as a passive acoustic receiver of bandwidth greater than 10 MHz. A 4-mm thick coating of special acoustical absorber forms the outer surface of the sensor. The layer functions as a shield to cavitation events occurring outside the hollow sensor body, allowing megahertz acoustic emissions emanating from within the liquid contained in the sensor to be monitored. Testing of the new sensor concept has been carried out within the cavitating field provided by a commercial ultrasonic cleaning vessel operating at 40 kHz whose power output is rated at 1 kW. It is demonstrated that the prototype cavitation sensors are able to record a systematic increase in the level of the high-frequency acoustic spectrum (> 1 MHz) as electrical power to the cleaning vessel is increased. Through careful control of the experimental conditions, reproducibility of the high frequency "energy" associated with the cavitation spectrum was found to be typically +25%.

  4. Acoustic method respiratory rate monitoring is useful in patients under intravenous anesthesia.

    Science.gov (United States)

    Ouchi, Kentaro; Fujiwara, Shigeki; Sugiyama, Kazuna

    2017-02-01

    Respiratory depression can occur during intravenous general anesthesia without tracheal intubation. A new acoustic method for respiratory rate monitoring, RRa(®) (Masimo Corp., Tokyo, Japan), has been reported to show good reliability in post-anesthesia care and emergency units. The purpose of this study was to investigate the reliability of the acoustic method for measurement of respiratory rate during intravenous general anesthesia, as compared with capnography. Patients with dental anxiety undergoing dental treatment under intravenous anesthesia without tracheal intubation were enrolled in this study. Respiratory rate was recorded every 30 s using the acoustic method and capnography, and detectability of respiratory rate was investigated for both methods. This study used a cohort study design. In 1953 recorded respiratory rate data points, the number of detected points by the acoustic method (1884, 96.5 %) was significantly higher than that by capnography (1682, 86.1 %) (P < 0.0001). In the intraoperative period, there was a significant difference in the LOA (95 % limits of agreement of correlation between difference and average of the two methods)/ULLOA (under the lower limit of agreement) in terms of use or non-use of a dental air turbine (P < 0.0001). In comparison between capnography, the acoustic method is useful for continuous monitoring of respiratory rate in spontaneously breathing subjects undergoing dental procedures under intravenous general anesthesia. However, the acoustic method might not accurately detect in cases in with dental air turbine.

  5. Comparison of PAM Systems for Acoustic Monitoring and Further Risk Mitigation Application.

    Science.gov (United States)

    Ludwig, Stefan; Kreimeyer, Roman; Knoll, Michaela

    2016-01-01

    We present results of the SIRENA 2011 research cruises conducted by the NATO Undersea Research Centre (NURC) and joined by the Research Department for Underwater Acoustics and Geophysics (FWG), Bundeswehr Technical Centre (WTD 71) and the Universities of Kiel and Pavia. The cruises were carried out in the Ligurian Sea. The main aim of the FWG was to test and evaluate the newly developed towed hydrophone array as a passive acoustic monitoring (PAM) tool for risk mitigation applications. The system was compared with the PAM equipment used by the other participating institutions. Recorded sounds were used to improve an automatic acoustic classifier for marine mammals, and validated acoustic detections by observers were compared with the results of the classifier.

  6. Acoustic Emission Measurement with Fiber Bragg Gratings for Structure Health Monitoring

    Science.gov (United States)

    Banks, Curtis E.; Walker, James L.; Russell, Sam; Roth, Don; Mabry, Nehemiah; Wilson, Melissa

    2010-01-01

    Structural Health monitoring (SHM) is a way of detecting and assessing damage to large scale structures. Sensors used in SHM for aerospace structures provide real time data on new and propagating damage. One type of sensor that is typically used is an acoustic emission (AE) sensor that detects the acoustic emissions given off from a material cracking or breaking. The use of fiber Bragg grating (FBG) sensors to provide acoustic emission data for damage detection is studied. In this research, FBG sensors are used to detect acoustic emissions of a material during a tensile test. FBG sensors were placed as a strain sensor (oriented parallel to applied force) and as an AE sensor (oriented perpendicular to applied force). A traditional AE transducer was used to collect AE data to compare with the FBG data. Preliminary results show that AE with FBGs can be a viable alternative to traditional AE sensors.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-02-01

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

  8. Acoustic and Visual Monitoring for Cetaceans Along the Outer Washington Coast

    Science.gov (United States)

    2009-03-01

    Clark, C.W. and P.J. Clapham. 2004. Acoustic monitoring on a humpback whale ( Megaptera novaeangliae ) feeding ground shows continual singing into late...Anne Douglas Cascadia Research Collective Olympia, WA Julie Rivers Naval Facilities Engineering Command, Pacific Pearl Harbor, HI

  9. Passive acoustic measurements of snapping shrimp from a reef monitoring feasibility test in Aruba

    NARCIS (Netherlands)

    Huntera, A.; Fillingera, L.; Clarijs, M.

    2014-01-01

    In December 2013, TNO made underwater measurements in Aruba to assess the feasibility of reef health monitoring using passive acoustics; this work was conducted in collaboration with Aruba Ports Authority, Aruba Marine Park, and Aruba Reef Care Foundation. Ambient noise recordings were made at vario

  10. A scalable acoustic sensor network for model based monitoring of urban traffic noise

    NARCIS (Netherlands)

    Basten, T.G.H.; Wessels, P.W.; Eerden, F.J.M. van der

    2012-01-01

    A good understanding of the acoustic environment due to traffic in urban areas is very important. Long term monitoring within large areas provides a clear insight in the actual noise situation. This is needed to take appropriate and cost efficient measures; to asses the effect of measures by compari

  11. Advanced Computing Methods for Knowledge Discovery and Prognosis in Acoustic Emission Monitoring

    Science.gov (United States)

    Mejia, Felipe

    2012-01-01

    Structural health monitoring (SHM) has gained significant popularity in the last decade. This growing interest, coupled with new sensing technologies, has resulted in an overwhelming amount of data in need of management and useful interpretation. Acoustic emission (AE) testing has been particularly fraught by the problem of growing data and is…

  12. Monitoring the Ocean Acoustic Environment: A Model-Based Detection Approach

    Energy Technology Data Exchange (ETDEWEB)

    Candy, J.V.; Sullivan, E.J.

    2000-03-13

    A model-based approach is applied in the development of a processor designed to passively monitor an ocean acoustic environment along with its associated variations. The technique employs an adaptive, model-based processor embedded in a sequential likelihood detection scheme. The trade-off between state-based and innovations-based monitor designs is discussed, conceptually. The underlying theory for the innovations-based design is briefly developed and applied to a simulated data set.

  13. Density can be misleading for low-density species: benefits of passive acoustic monitoring.

    Science.gov (United States)

    Rogers, Tracey L; Ciaglia, Michaela B; Klinck, Holger; Southwell, Colin

    2013-01-01

    Climate-induced changes may be more substantial within the marine environment, where following ecological change is logistically difficult, and typically expensive. As marine animals tend to produce stereotyped, long-range signals, they are ideal for repeatable surveying. In this study we illustrate the potential for calling rates to be used as a tool for determining habitat quality by using an Antarctic pack-ice seal, the leopard seal, as a model.With an understanding of the vocal behavior of a species, their seasonal and diurnal patterns, sex and age-related differences, an underwater passive-acoustic survey conducted alongside a visual survey in an arc of 4,225 km across the Davis Sea, Eastern Antarctica, showed that while acoustic and visual surveys identified similar regions as having high densities, the acoustic surveys surprisingly identified the opposite regions as being 'critical' habitats. Density surveys of species that cannot be differentiated into population classes may be misleading because overall density can be a negative indicator of habitat quality.Under special circumstances acoustics can offer enormous advantage over traditional techniques and open up monitoring to regions that are remote, difficult and expensive to work within, no longer restricting long-term community assessment to resource-wealthy communities. As climatic change affects a broad range of organisms across geographic boundaries we propose that capitalizing on the significant advances in passive acoustic technology, alongside physical acoustics and population modeling, can help in addressing ecological questions more broadly.

  14. Density can be misleading for low-density species: benefits of passive acoustic monitoring.

    Directory of Open Access Journals (Sweden)

    Tracey L Rogers

    Full Text Available Climate-induced changes may be more substantial within the marine environment, where following ecological change is logistically difficult, and typically expensive. As marine animals tend to produce stereotyped, long-range signals, they are ideal for repeatable surveying. In this study we illustrate the potential for calling rates to be used as a tool for determining habitat quality by using an Antarctic pack-ice seal, the leopard seal, as a model.With an understanding of the vocal behavior of a species, their seasonal and diurnal patterns, sex and age-related differences, an underwater passive-acoustic survey conducted alongside a visual survey in an arc of 4,225 km across the Davis Sea, Eastern Antarctica, showed that while acoustic and visual surveys identified similar regions as having high densities, the acoustic surveys surprisingly identified the opposite regions as being 'critical' habitats. Density surveys of species that cannot be differentiated into population classes may be misleading because overall density can be a negative indicator of habitat quality.Under special circumstances acoustics can offer enormous advantage over traditional techniques and open up monitoring to regions that are remote, difficult and expensive to work within, no longer restricting long-term community assessment to resource-wealthy communities. As climatic change affects a broad range of organisms across geographic boundaries we propose that capitalizing on the significant advances in passive acoustic technology, alongside physical acoustics and population modeling, can help in addressing ecological questions more broadly.

  15. Monitoring of Changes Signal Acoustic Emission Signals Using Waveguides

    Directory of Open Access Journals (Sweden)

    Jaroslav Začal

    2017-01-01

    Full Text Available This paper is focused on possibilities of acoustic emission (AE signal detection from material surface through waveguide for commonly used piezoelectric sensors. It also considers the experimental study of enhanced detection of occurrence of signal guided through waveguide corpus, its changes and deformities. Aim of this work is verification of several waveguide setup possibilities for maximization of AE signal detection in practice. For this purpose, multiple waveguide setups were manufactured from stainless steel and aluminium alloy. Hsu‑Nielson pen test was utilized for signal actuation. Results demonstrate the differences between measured AE signal with and without employment of waveguide (changes in signal course through different materials and shapes, as well as magnitude of signal dampening and amplification necessary for veritable signal interpretation. Measurements were conducted on agglomerated composite of medium density fibreboard (MDF.

  16. Towards efficient real-time submarine power cable monitoring using distributed fibre optic acoustic sensors

    Science.gov (United States)

    Hicke, Konstantin; Krebber, Katerina

    2017-04-01

    Online condition monitoring of submarine power cables helps to avert failures and damages produced by mechanical impacts. We report, to our knowledge for the first time, on investigations regarding the feasibility of distributed fiber optic acoustic sensors based on C-OTDR, with the sensor fibers being embedded in the cable, to detect vibrations due to mechanical disturbances along the cable. We present first results of sensing experiments where acoustic signals are transmitted through water to simulate the corresponding submarine conditions. Furthermore, we show results evaluating the usefulness of fibre commonly embedded in existing power cable designs for our sensing purposes.

  17. Monitoring Gold Nanoparticle Growth in Situ via the Acoustic Vibrations Probed by Four-Wave Mixing.

    Science.gov (United States)

    Wu, Jian; Xiang, Dao; Gordon, Reuven

    2017-02-21

    We monitor in situ gold nanoparticle growth in aqueous solution by probing the acoustic vibrations with four-wave mixing. We observe two acoustic vibrational modes of gold nanoparticles from the nonlinear optical response: an extensional mode with longitudinal expansion and transverse contraction and a breathing mode with radial expansion and contraction. The mode frequencies, which show an inverse dependence on the nanoparticle diameter, allow one to monitor the nanoparticle size and size distribution during synthesis. The information about the nanoparticle size and size distribution calculated on the basis of the mode frequencies agrees well with the results obtained from the electron microscopy analysis, validating the four-wave mixing technique as an accurate and effective tool for in situ monitoring of colloidal growth.

  18. Acoustic emission monitoring of hot functional testing: Watts Bar Unit 1 Nuclear Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Hutton, P.H.; Dawson, J.F.; Friesel, M.A.; Harris, J.C.; Pappas, R.A.

    1984-06-01

    Acoustic emission (AE) monitoring of selected pressure boundary areas at TVA's Watts Bar, Unit 1 Nuclear Power Plant during hot functional preservice testing is described in this report. The report deals with background, methodology, and results. The work discussed here is a major milestone in a program supported by NRC to develop and demonstrate application of AE monitoring for continuous surveillance of reactor pressure boundaries to detect and evaluate growing flaws. The subject work demonstrated that anticipated problem areas can be overcome. Work is continuing toward AE monitoring during reactor operation.

  19. The DMON2: A Commercially Available Broadband Acoustic Monitoring Instrument

    Science.gov (United States)

    2015-09-30

    the efficiency of finding animals at sea for study (e.g., for tagging or photo- identification). For the National Oceanic and Atmospheric...Administration (NOAA), such a capability would allow improved monitoring of the distribution and occurrence of vocalizing animals for improving our...mechanical drawings nearly finalized. Endcap design done and fabricated; need to finalize Transducer Head mold for encapsulation. • Schematic

  20. The Doppler Effect based acoustic source separation for a wayside train bearing monitoring system

    Science.gov (United States)

    Zhang, Haibin; Zhang, Shangbin; He, Qingbo; Kong, Fanrang

    2016-01-01

    Wayside acoustic condition monitoring and fault diagnosis for train bearings depend on acquired acoustic signals, which consist of mixed signals from different train bearings with obvious Doppler distortion as well as background noises. This study proposes a novel scheme to overcome the difficulties, especially the multi-source problem in wayside acoustic diagnosis system. In the method, a time-frequency data fusion (TFDF) strategy is applied to weaken the Heisenberg's uncertainty limit for a signal's time-frequency distribution (TFD) of high resolution. Due to the Doppler Effect, the signals from different bearings have different time centers even with the same frequency. A Doppler feature matching search (DFMS) algorithm is then put forward to locate the time centers of different bearings in the TFD spectrogram. With the determined time centers, time-frequency filters (TFF) are designed with thresholds to separate the acoustic signals in the time-frequency domain. Then the inverse STFT (ISTFT) is taken and the signals are recovered and filtered aiming at each sound source. Subsequently, a dynamical resampling method is utilized to remove the Doppler Effect. Finally, accurate diagnosis for train bearing faults can be achieved by applying conventional spectrum analysis techniques to the resampled data. The performance of the proposed method is verified by both simulated and experimental cases. It shows that it is effective to detect and diagnose multiple defective bearings even though they produce multi-source acoustic signals.

  1. Acoustic Emission Weld Monitor System. Data Acquisition and Investigation

    Science.gov (United States)

    1979-10-01

    TARADCOM-furnished armor plate yielded the results shown in Table 2a. Table 2b shows the nominal chemical compositions of three HY steels , namely HY80 ...AE signals, as compared with previous experience monitoring submerged arc welding of mild carbon steels , was correlated with a large number of...observed that the background AE level was at times significantly greater than that for submerged arc welding of mild steels . The relatively high number

  2. Large-scale semi-automated acoustic monitoring allows to detect temporal decline of bush-crickets

    Directory of Open Access Journals (Sweden)

    Alienor Jeliazkov

    2016-04-01

    To our knowledge, this paper describes the first successful attempt to calculate large-scale temporal trends of insect populations on the basis of an automatic identification process of acoustic data. We argue that acoustic monitoring along roads, coupled with the automatic recognition of species sounds, offers several advantages for assessing Orthoptera biodiversity response to global changes and environmental measures.

  3. Monitoring of Robot Assisted Polishing through parameters of acoustic emission

    DEFF Research Database (Denmark)

    Lazarev, Ruslan; Top, Søren; Bilberg, Arne

    The polishing process is essential for the surface generation of machine tooling components in advanced manufacturing. While robot assisted polishing is faster and more consistent than manual polishing, it can still consume a significant part of ma- chining time and operator presence time....... The determination of the point in time to change a polishing media or stop the process is needed for computer controlled functional surface generation. During the last years, several research works have been done in order to build grinding/polishing monitoring systems to determine process characteristics...

  4. Detection of corrosion processes and fatigue cracks by means of acoustic emission monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Jagenbrein, Andreas; Tscheliesnig, Peter [TUEV Austria Services GmbH, Vienna (Austria); Wachsmuth, Janne; Bohse, Juergen [Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin (Germany)

    2012-07-01

    Fatigue crack growth and active corrosion processes are the main causes for structural failures of transport products like road tankers, railway tank cars, and ships. Within the 7{sup th} EC framework programme the aim of project CORFAT is to develop a new monitoring technology based on acoustic emission testing (AT) of the structural integrity in terms of proceeding degradation. Differentiation of acoustic emission (AE) signals of real degradation processes by fatigue crack growth or active corrosion from operational or environmental background noise requires the signal classification using also pattern recognition. Therefore, a data base of AE signals related to the different source mechanisms was built up experimentally. In this article selected results of corrosion and fatigue tests in the laboratory as well as results of monitoring background noise during moving of a road tanker are described. (orig.)

  5. Apparatus and method for acoustic monitoring of steam quality and flow

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, Dipen N.; Pantea, Cristian

    2016-09-13

    An apparatus and method for noninvasively monitoring steam quality and flow and in pipes or conduits bearing flowing steam, are described. By measuring the acoustic vibrations generated in steam-carrying conduits by the flowing steam either by direct contact with the pipe or remotely thereto, converting the measured acoustic vibrations into a frequency spectrum characteristic of the natural resonance vibrations of the pipe, and monitoring the amplitude and/or the frequency of one or more chosen resonance frequencies, changes in the steam quality in the pipe are determined. The steam flow rate and the steam quality are inversely related, and changes in the steam flow rate are calculated from changes in the steam quality once suitable calibration curves are obtained.

  6. Simultaneous acoustic and dielectric real time curing monitoring of epoxy systems

    Science.gov (United States)

    Gkikas, G.; Saganas, Ch.; Grammatikos, S. A.; Aggelis, D. G.; Paipetis, A. S.

    2012-04-01

    The attainment of structural integrity of the reinforcing matrix in composite materials is of primary importance for the final properties of the composite structure. The detailed monitoring of the curing process on the other hand is paramount (i) in defining the optimal conditions for the impregnation of the reinforcement by the matrix (ii) in limiting the effects of the exotherm produced by the polymerization reaction which create unwanted thermal stresses and (iii) in securing optimal behavior in matrix controlled properties, such as off axis or shear properties and in general the durability of the composite. Dielectric curing monitoring is a well known technique for distinguishing between the different stages of the polymerization of a typical epoxy system. The technique successfully predicts the gelation and the vitrification of the epoxy and has been extended for the monitoring of prepregs. Recent work has shown that distinct changes in the properties of the propagated sound in the epoxy which undergoes polymerization is as well directly related to the gelation and vitrification of the resin, as well as to the attainment of the final properties of the resin system. In this work, a typical epoxy is simultaneously monitored using acoustic and dielectric methods. The system is isothermally cured in an oven to avoid effects from the polymerization exotherm. Typical broadband sensors are employed for the acoustic monitoring, while flat interdigital sensors are employed for the dielectric scans. All stages of the polymerization process were successfully monitored and the validity of both methods was cross checked and verified.

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

    Science.gov (United States)

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

    2013-12-01

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

  8. Thermometric- and Acoustic-Based Beam Power Monitor for Ultra-Bright X-Rays

    Energy Technology Data Exchange (ETDEWEB)

    Bentsen, Gregory; /Rochester U. /SLAC

    2010-08-25

    A design for an average beam power monitor for ultra-bright X-ray sources is proposed that makes simultaneous use of calorimetry and radiation acoustics. Radiation incident on a solid target will induce heating and ultrasonic vibrations, both of which may be measured to give a fairly precise value of the beam power. The monitor is intended for measuring ultra-bright Free-Electron Laser (FEL) X-ray beams, for which traditional monitoring technologies such as photo-diodes or scintillators are unsuitable. The monitor consists of a Boron Carbide (B{sub 4}C) target designed to absorb most of the incident beam's energy. Resistance temperature detectors (RTD) and piezoelectric actuators are mounted on the outward faces of the target to measure the temperature changes and ultrasonic vibrations induced by the incident beam. The design was tested using an optical pulsed beam (780 nm, 120 and 360 Hz) from a Ti:sapphire oscillator at several energies between 0.8 and 2.6 mJ. The RTDs measured an increase in temperature of about 10 K over a period of several minutes. The piezoelectric sensors recorded ringing acoustic oscillations at 580 {+-} 40 kHz. Most importantly, the amplitude of the acoustic signals was observed to scale linearly with beam power up to 2 mJ of pulse energy. Above this pulse energy, the vibrational signals became nonlinear. Several causes for this nonlinearity are discussed, including amplifier saturation and piezoelectric saturation. Despite this nonlinearity, these measurements demonstrate the feasibility of such a beam power measurement device. The advantage of two distinct measurements (acoustic and thermometric) provides a useful method of calibration that is unavailable to current LCLS diagnostics tools.

  9. Acoustic monitoring on a humpback whale (Megaptera novaeangliae) feeding ground shows continual singing into late Spring.

    OpenAIRE

    Clark, Christopher W.; Clapham, Phillip J.

    2004-01-01

    Singing by males is a major feature of the mating system of humpback whales, Megaptera novaeangliae (Borowski). Although a few songs have been opportunistically recorded on the whales' high-latitude feeding grounds, singing in these regions was thought to be only sporadic. We report results from the first continuous acoustic monitoring of a humpback whale feeding ground (off Cape Cod, MA, USA) in spring. Using autonomous sea-floor recording systems, we found singing on a daily basis over the ...

  10. Acoustic Emission Monitoring of Multicell Reinforced Concrete Box Girders Subjected to Torsion

    OpenAIRE

    Marya Bagherifaez; Arash Behnia; Abeer Aqeel Majeed; Chai Hwa Kian

    2014-01-01

    Reinforced concrete (RC) box girders are a common structural member for road bridges in modern construction. The hollow cross-section of a box girder is ideal in carrying eccentric loads or torques introduced by skew supports. This study employed acoustic emission (AE) monitoring on multicell RC box girder specimens subjected to laboratory-based torsion loading. Three multicell box girder specimens with different cross-sections were tested. The aim is to acquire AE analysis data indicative fo...

  11. Chemometrics review for chemical sensor development, task 7 report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-05-01

    This report, the seventh in a series on the evaluation of several chemical sensors for use in the U.S. Department of Energy`s (DOE`s) site characterization and monitoring programs, concentrates on the potential use of chemometrics techniques in analysis of sensor data. Chemometrics is the chemical discipline that uses mathematical, statistical, and other methods that employ formal logic to: design or select optimal measurement procedures and experiments and provide maximum relevant chemical information by analyzing chemical data. The report emphasizes the latter aspect. In a formal sense, two distinct phases are in chemometrics applications to analytical chemistry problems: (1) the exploratory data analysis phase and (2) the calibration and prediction phase. For use in real-world problems, it is wise to add a third aspect - the independent validation and verification phase. In practical applications, such as the ERWM work, and in order of decreasing difficulties, the most difficult tasks in chemometrics are: establishing the necessary infrastructure (to manage sampling records, data handling, and data storage and related aspects), exploring data analysis, and solving calibration problems, especially for nonlinear models. Chemometrics techniques are different for what are called zeroth-, first-, and second-order systems, and the details depend on the form of the assumed functional relationship between the measured response and the concentrations of components in mixtures. In general, linear relationships can be handled relatively easily, but nonlinear relationships can be difficult.

  12. Approaches to handle nonlinearities and nonnormalities in process chemometrics

    NARCIS (Netherlands)

    Thissen, Uwe Maria Johannes

    2004-01-01

    For every industrial process, it is of paramount interest to online monitor the performance of the process and to assess the quality of the products made. In order to meet these goals, the field of process control works on understanding and improving industrial processes. Process chemometrics can be

  13. Evaluating Acoustic Emission Signals as an in situ process monitoring technique for Selective Laser Melting (SLM)

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, Karl A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Candy, Jim V. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Guss, Gabe [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Mathews, M. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-10-14

    In situ real-time monitoring of the Selective Laser Melting (SLM) process has significant implications for the AM community. The ability to adjust the SLM process parameters during a build (in real-time) can save time, money and eliminate expensive material waste. Having a feedback loop in the process would allow the system to potentially ‘fix’ problem regions before a next powder layer is added. In this study we have investigated acoustic emission (AE) phenomena generated during the SLM process, and evaluated the results in terms of a single process parameter, of an in situ process monitoring technique.

  14. Acoustic emission-based in-process monitoring of surface generation in robot-assisted polishing

    DEFF Research Database (Denmark)

    Pilny, Lukas; Bissacco, Giuliano; De Chiffre, Leonardo

    2016-01-01

    The applicability of acoustic emission (AE) measurements for in-process monitoring of surface generation in the robot-assisted polishing (RAP) was investigated. Surface roughness measurements require interruption of the process, proper surface cleaning and measurements that sometimes necessitate...... removal of the part from the machine tool. In this study, stabilisation of surface roughness during polishing rotational symmetric surfaces by the RAP process was monitored by AE measurements. An AE sensor was placed on a polishing arm in direct contact with a bonded abrasive polishing tool...

  15. A Device for Fetal Monitoring by Means of Control Over Cardiovascular Parameters Based on Acoustic Data

    Science.gov (United States)

    Khokhlova, L. A.; Seleznev, A. I.; Zhdanov, D. S.; Zemlyakov, I. Yu; Kiseleva, E. Yu

    2016-01-01

    The problem of monitoring fetal health is topical at the moment taking into account a reduction in the level of fertile-age women's health and changes in the concept of perinatal medicine with reconsideration of live birth criteria. Fetal heart rate monitoring is a valuable means of assessing fetal health during pregnancy. The routine clinical measurements are usually carried out by the means of ultrasound cardiotocography. Although the cardiotocography monitoring provides valuable information on the fetal health status, the high quality ultrasound devices are expensive, they are not available for home care use. The recommended number of measurement is also limited. The passive and fully non-invasive acoustic recording provides an alternative low-cost measurement method. The article describes a device for fetal and maternal health monitoring by analyzing the frequency and periodicity of heart beats by means of acoustic signal received on the maternal abdomen. Based on the usage of this device a phonocardiographic fetal telemedicine system, which will allow to reduce the antenatal fetal mortality rate significantly due to continuous monitoring over the state of fetus regardless of mother's location, can be built.

  16. On the Application of the Raspberry Pi as an Advanced Acoustic Sensor Network for Noise Monitoring

    Directory of Open Access Journals (Sweden)

    Juan Emilio Noriega-Linares

    2016-10-01

    Full Text Available The concept of Smart Cities and the monitoring of environmental parameters is an area of research that has attracted scientific attention during the last decade. These environmental parameters are well-known as important factors in their affection towards people. Massive monitoring of this kind of parameters in cities is an expensive and complex task. Recent technologies of low-cost computing and low-power devices have opened researchers to a wide and more accessible research field, developing monitoring devices for deploying Wireless Sensor Networks. Gathering information from them, improved urban plans could be carried out and the information could help citizens. In this work, the prototyping of a low-cost acoustic sensor based on the Raspberry Pi platform for its use in the analysis of the sound field is described. The device is also connected to the cloud to share results in real time. The computation resources of the Raspberry Pi allow treating high quality audio for calculating acoustic parameters. A pilot test was carried out with the installation of two acoustic devices in the refurbishment works of a neighbourhood. In this deployment, the evaluation of these devices through long-term measurements was carried out, obtaining several acoustic parameters in real time for its broadcasting and study. This test has shown the Raspberry Pi as a powerful and affordable computing core of a low-cost device, but also the pilot test has served as a query tool for the inhabitants of the neighbourhood to be more aware about the noise in their own place of residence.

  17. An acoustic-array based structural health monitoring technique for wind turbine blades

    Science.gov (United States)

    Aizawa, Kai; Poozesh, Peyman; Niezrecki, Christopher; Baqersad, Javad; Inalpolat, Murat; Heilmann, Gunnar

    2015-04-01

    This paper proposes a non-contact measurement technique for health monitoring of wind turbine blades using acoustic beamforming techniques. The technique works by mounting an audio speaker inside a wind turbine blade and observing the sound radiated from the blade to identify damage within the structure. The main hypothesis for the structural damage detection is that the structural damage (cracks, edge splits, holes etc.) on the surface of a composite wind turbine blade results in changes in the sound radiation characteristics of the structure. Preliminary measurements were carried out on two separate test specimens, namely a composite box and a section of a wind turbine blade to validate the methodology. The rectangular shaped composite box and the turbine blade contained holes with different dimensions and line cracks. An acoustic microphone array with 62 microphones was used to measure the sound radiation from both structures when the speaker was located inside the box and also inside the blade segment. A phased array beamforming technique and CLEAN-based subtraction of point spread function from a reference (CLSPR) were employed to locate the different damage types on both the composite box and the wind turbine blade. The same experiment was repeated by using a commercially available 48-channel acoustic ring array to compare the test results. It was shown that both the acoustic beamforming and the CLSPR techniques can be used to identify the damage in the test structures with sufficiently high fidelity.

  18. Crack Propagation Analysis Using Acoustic Emission Sensors for Structural Health Monitoring Systems

    Science.gov (United States)

    Horn, Walter; Steck, James

    2013-01-01

    Aerospace systems are expected to remain in service well beyond their designed life. Consequently, maintenance is an important issue. A novel method of implementing artificial neural networks and acoustic emission sensors to form a structural health monitoring (SHM) system for aerospace inspection routines was the focus of this research. Simple structural elements, consisting of flat aluminum plates of AL 2024-T3, were subjected to increasing static tensile loading. As the loading increased, designed cracks extended in length, releasing strain waves in the process. Strain wave signals, measured by acoustic emission sensors, were further analyzed in post-processing by artificial neural networks (ANN). Several experiments were performed to determine the severity and location of the crack extensions in the structure. ANNs were trained on a portion of the data acquired by the sensors and the ANNs were then validated with the remaining data. The combination of a system of acoustic emission sensors, and an ANN could determine crack extension accurately. The difference between predicted and actual crack extensions was determined to be between 0.004 in. and 0.015 in. with 95% confidence. These ANNs, coupled with acoustic emission sensors, showed promise for the creation of an SHM system for aerospace systems. PMID:24023536

  19. Monitoring Anthropogenic Ocean Sound from Shipping Using an Acoustic Sensor Network and a Compressive Sensing Approach.

    Science.gov (United States)

    Harris, Peter; Philip, Rachel; Robinson, Stephen; Wang, Lian

    2016-03-22

    Monitoring ocean acoustic noise has been the subject of considerable recent study, motivated by the desire to assess the impact of anthropogenic noise on marine life. A combination of measuring ocean sound using an acoustic sensor network and modelling sources of sound and sound propagation has been proposed as an approach to estimating the acoustic noise map within a region of interest. However, strategies for developing a monitoring network are not well established. In this paper, considerations for designing a network are investigated using a simulated scenario based on the measurement of sound from ships in a shipping lane. Using models for the sources of the sound and for sound propagation, a noise map is calculated and measurements of the noise map by a sensor network within the region of interest are simulated. A compressive sensing algorithm, which exploits the sparsity of the representation of the noise map in terms of the sources, is used to estimate the locations and levels of the sources and thence the entire noise map within the region of interest. It is shown that although the spatial resolution to which the sound sources can be identified is generally limited, estimates of aggregated measures of the noise map can be obtained that are more reliable compared with those provided by other approaches.

  20. Strategies for rock slope failure early warning using acoustic emission monitoring

    Science.gov (United States)

    Codeglia, D.; Dixon, N.; Fowmes, G. J.; Marcato, G.

    2015-09-01

    Research over the last two decades has led to development of a system for soil slopes monitoring based on the concept of measuring Acoustic Emission (AE). A feature of the system is the use of waveguides installed within unstable soil slopes. It has been demonstrated that the AE measured through this technique are proportional to soil displacement rate. Attention has now been focused on the prospect of using the system within rock materials. The different nature of the slope material to be monitored and its setting means that different acoustic trends are measured, and development of new approaches for their interpretation are required. A total of six sensors have been installed in two pilot sites, firstly in Italy, for monitoring of a stratified limestone slope which can threaten a nationally important road, and secondly in Austria, for monitoring of a conglomerate slope that can endanger a section of the local railway. In this paper an outline of the two trial sites is given and AE data collected are compared with other physical measurements (i.e. rainfall and temperature) and traditional geotechnical instrumentation, to give an overview of recurring AE trends. These include clear AE signatures generated by stress changes linked to increased ground water levels and high energy events generated by freeze-thaw of the rock mass.

  1. Deep-water riser fatigue monitoring systems based on acoustic telemetry

    Science.gov (United States)

    Li, Baojun; Wang, Haiyan; Shen, Xiaohong; Yan, Yongsheng; Yang, Fuzhou; Hua, Fei

    2014-12-01

    Marine risers play a key role in the deep and ultra-deep water oil and gas production. The vortex-induced vibration (VIV) of marine risers constitutes an important problem in deep water oil exploration and production. VIV will result in high rates of structural failure of marine riser due to fatigue damage accumulation and diminishes the riser fatigue life. In-service monitoring or full scale testing is essential to improve our understanding of VIV response and enhance our ability to predict fatigue damage. One marine riser fatigue acoustic telemetry scheme is proposed and an engineering prototype machine has been developed to monitor deep and ultra-deep water risers' fatigue and failure that can diminish the riser fatigue life and lead to economic losses and eco-catastrophe. Many breakthroughs and innovation have been achieved in the process of developing an engineering prototype machine. Sea trials were done on the 6th generation deep-water drilling platform HYSY-981 in the South China Sea. The inclination monitoring results show that the marine riser fatigue acoustic telemetry scheme is feasible and reliable and the engineering prototype machine meets the design criterion and can match the requirements of deep and ultra-deep water riser fatigue monitoring. The rich experience and field data gained in the sea trial which provide much technical support for optimization in the engineering prototype machine in the future.

  2. Remote structural health monitoring with serially multiplexed fiber optic acoustic emission sensors

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Development and testing of a serially multiplexed fiber optic sensor system is described. The sensor differs from conventional fiber optic acoustic systems, as it is capable of sensing AE emissions at several points along the length of a single fiber. Multiplexing provides for single channel detection of cracks and their locations in large structural systems. An algorithm was developed for signal recognition and tagging of the AE waveforms for detection of crack locations. Laboratory experiments on plain concrete beams and post-tensioned FRP tendons were performed to evaluate the crack detection capability of the sensor system. The acoustic emission sensor was able to detect initiation, growth and location of the cracks in concrete as well as in the FRP tendons. The AE system is potentially suitable for applications involving health monitoring of structures following an earthquake.

  3. Monitoring of Acoustic Emissions Within Geothermal Areas in Iceland: A new Tool for Geothermal Exploration.

    Science.gov (United States)

    Brandsdóttir, B.; Gudmundsson, O.

    2007-12-01

    With increased emphasis on geothermal development new exploration methods are needed in order to improve general understanding of geothermal reservoirs, characterize their extent and assess the potential for sustainable power production. Monitoring of acoustic emissions within geothermal areas may provide a new tool to evaluate the spatial extent of geothermal fields and model rock-fluid interactions. Three-dimensional seismic data have been used to assess the spatial and temporal distribution of noise within several high-temperature geothermal fields in Iceland. Seismic noise in the 4-6 Hz range within the Svartsengi field can be attributed to steam hydraulics and pressure oscillations within the geothermal reservoirs. Seismic noise surveys compliment electrical resistivity soundings and TEM-surveys by providing information pertinent to the current geothermal activity and extent of steam fields within the uppermost crust of the geothermal reservoir. Information related to acoustic emissions can thus help define targets for future wells.

  4. Passive acoustic monitoring of toothed whales with implications for mitigation, management and biology

    DEFF Research Database (Denmark)

    Kyhn, Line Anker

    Toothed whales are vocal animals and their social life as well as successful orientation and feeding depends on emission and reception of sound. Such sounds may e.g. be clicks used for echolocation or whistles used for communication and they can be monitored in time and space by means of passive...... rate from acoustic tags being fitted to wild harbour porpoises. From the visual sighting we also estimated density within 100 m radius of each datalogger. The detection functions were successful in estimating densities of around the same level as we found for the visual observations, and more...... descriptions. A species' sounds must be well defined according to specific sound source parameters to be able to build precise filters for the acoustic dataloggers to sort the correct signals from noise. Such definitions require that the variation at the level of species is known and therefore that each focal...

  5. Acoustic emission technique for monitoring the pyrolysis of composites for process control.

    Science.gov (United States)

    Tittmann, B R; Yen, C E

    2008-11-01

    Carbonization is the first step in the heat and pressure treatment (pyrolysis) of composites in preparing carbon-carbon parts. These find many uses, including aircraft brakes, rocket nozzles and medical implants. This paper describes the acoustic emissions (AE) from various stages of the manufacturing process of carbon-carbon composites. This process involves carbonization at a high temperature and this results in both thermal expansion and volume change (due to pyrolysis in which a sacrificial polymer matrix is converted to carbon). Importantly the resultant matrix is porous and has a network of small intra-lamina cracks. The formation of these microcracks produces AE and this paper describes how this observation can be used to monitor (and eventually control) the manufacturing process. The aim is to speed up manufacture, which is currently time-consuming. The first section of the paper describes the design of unimodal waveguides to enable the AE to propagate to a cool environment where a transducer can be located. The second part of the paper describes various experimental observations of AE under a range of process conditions. In particular, this paper presents a technique based on detecting acoustic emissions and (1) uses wire waveguides to monitor parts within the autoclave to 800 degrees C, (2) monitors microcracking during pyrolysis, (3) uses a four-level threshold to distinguish between low- and high-amplitude cracking events, (4) recognizes the occurrence of harmful delaminations, and (5) guides the control of the heating rate for optimum efficiency of the pyrolysis process. In addition, supporting data are presented of in situ measurements of porosity, weight loss, cross-ply shrinkage, and mass spectroscopy of gases emitted. The process evolution is illustrated by the use of interrupted manufacturing cycle micrographs obtained by optical, scanning acoustic (SAM) and scanning electron (SEM) microscopy. The technique promotes in-process monitoring and

  6. Robust procedures in chemometrics

    DEFF Research Database (Denmark)

    Kotwa, Ewelina

    -way chemometrical methods, such as PCA and PARAFAC models for analysing spatial and depth profiles of sea water samples, defined by three data modes: depth, variables and geographical location. Emphasis was also put on predicting fluorescence values, as being a natural measure of biological activity, by applying....... applying a multivariate and multi-way data analytical frame-work in fields where less sophisticated data analysis methods are currently used, and 2. developing new, more robust alternatives to already existing multivariate tools. The first part of the study was realised by applying two- and three...... and comparing the Partial Least Squares (PLS) regression technique with its multi-way alternative, N-PLS. Results of the analysis indicated superiority of the three-way frame-work, potentially constituting a novel assessment of the sea water measurements. Particularly in the case of regression models...

  7. Acoustic Monitor for Liquid-Solid Slurries Measurements at Low Weight Fractions

    Energy Technology Data Exchange (ETDEWEB)

    Taviarides, Lawrence L.

    2005-06-01

    Our effort in this project is to develop an acoustic monitor for accurate, real-time characterization of the size and weight fractions of solids in slurries for process monitoring and to determine the optimal timing for slurry transfers. This capability will be valuable in the Savannah River Site accelerated clean-up program. Our scientific work during the first research period developed a theory, supported by experiments, to describe sound attenuation of solids in suspensions in the presence of bubbles, which permits us to determine the solid-liquid weight percent. Engineering developments during the second research period led to the design, construction, and demonstration, in our laboratories, of the Syracuse Acoustic Monitor (SAM) system that measures weight percent solids accurately in slurries of 0.5 to 8.0 weight percent on-line and in real-time. Also, we had shown the potential for these measurements in solid-gas-liquid slurries by removing the interference due to the presence of gas bubbles.

  8. Micro-electromechanical film bulk acoustic sensor for plasma and whole blood coagulation monitoring.

    Science.gov (United States)

    Chen, Da; Song, Shuren; Ma, Jilong; Zhang, Zhen; Wang, Peng; Liu, Weihui; Guo, Qiuquan

    2017-05-15

    Monitoring blood coagulation is an important issue in the surgeries and the treatment of cardiovascular diseases. In this work, we reported a novel strategy for the blood coagulation monitoring based on a micro-electromechanical film bulk acoustic resonator. The resonator was excited by a lateral electric field and operated under the shear mode with a frequency of 1.9GHz. According to the apparent step-ladder curves of the frequency response to the change of blood viscoelasticity, the coagulation time (prothrombin time) and the coagulation kinetics were measured with the sample consumption of only 1μl. The procoagulant activity of thromboplastin and the anticoagulant effect of heparin on the blood coagulation process were illustrated exemplarily. The measured prothrombin times showed a good linear correlation with R(2)=0.99969 and a consistency with the coefficient of variation less than 5% compared with the commercial coagulometer. The proposed film bulk acoustic sensor, which has the advantages of small size, light weight, low cost, simple operation and little sample consumption, is a promising device for miniaturized, online and automated analytical system for routine diagnostics of hemostatic status and personal health monitoring.

  9. Ambient Noise Surface Wave Tomography for Geotechnical Monitoring Using "Large N" Distributed Acoustic Sensing

    Science.gov (United States)

    Ajo Franklin, J. B.; Lindsey, N.; Martin, E. R.; Wagner, A. M.; Robertson, M.; Bjella, K.; Gelvin, A.; Ulrich, C.; Wu, Y.; Freifeld, B. M.; Daley, T. M.; Dou, S.

    2015-12-01

    Surface wave tomography using ambient noise sources has found broad application at the regional scale but has not been adopted fully for geotechnical applications despite the abundance of noise sources in this context. The recent development of Distributed Acoustic Sensing (DAS) provides a clear path for inexpensively recording high spatial resolution (survey as well as direct-push data on ice content. We also compare vintages of ambient noise DAS data to evaluate the short-term repeatability of the technique in the face of changing noise environments. The resulting dataset demonstrates the utility of using DAS for real-time shear-modulus monitoring in support of critical infrastructure.

  10. Damage accumulation in cyclically-loaded glass-ceramic matrix composites monitored by acoustic emission.

    Science.gov (United States)

    Aggelis, D G; Dassios, K G; Kordatos, E Z; Matikas, T E

    2013-01-01

    Barium osumilite (BMAS) ceramic matrix composites reinforced with SiC-Tyranno fibers are tested in a cyclic loading protocol. Broadband acoustic emission (AE) sensors are used for monitoring the occurrence of different possible damage mechanisms. Improved use of AE indices is proposed by excluding low-severity signals based on waveform parameters, rather than only threshold criteria. The application of such improvements enhances the accuracy of the indices as accumulated damage descriptors. RA-value, duration, and signal energy follow the extension cycles indicating moments of maximum or minimum strain, while the frequency content of the AE signals proves very sensitive to the pull-out mechanism.

  11. Damage Accumulation in Cyclically-Loaded Glass-Ceramic Matrix Composites Monitored by Acoustic Emission

    Directory of Open Access Journals (Sweden)

    D. G. Aggelis

    2013-01-01

    Full Text Available Barium osumilite (BMAS ceramic matrix composites reinforced with SiC-Tyranno fibers are tested in a cyclic loading protocol. Broadband acoustic emission (AE sensors are used for monitoring the occurrence of different possible damage mechanisms. Improved use of AE indices is proposed by excluding low-severity signals based on waveform parameters, rather than only threshold criteria. The application of such improvements enhances the accuracy of the indices as accumulated damage descriptors. RA-value, duration, and signal energy follow the extension cycles indicating moments of maximum or minimum strain, while the frequency content of the AE signals proves very sensitive to the pull-out mechanism.

  12. Mechanical degradation of cross-ply laminates monitored by acoustic emission

    Science.gov (United States)

    Paipetis, A.; Xyrafa, M.; Barkoula, N. M.; Matikas, T. E.; Aggelis, D. G.

    2011-04-01

    This study deals with the investigation of cross ply composites failure by acoustic emission (AE). Broadband AE sensors monitor the different sources of failure in coupons of this material during a tensile loading-unloading test. The cumulative number of AE activity, and other qualitative indices based on the shape of the waves, were well correlated to the sustained load. AE parameters indicate the shift of failure mechanisms within the composite as the load increases. The ultimate goal is a methodology based on NDT techniques for real time characterization of the degradation and identification of the fracture stage of advanced composite materials.

  13. Health monitoring of Ceramic Matrix Composites from waveform-based analysis of Acoustic Emission

    Directory of Open Access Journals (Sweden)

    Maillet Emmanuel

    2015-01-01

    Full Text Available Ceramic Matrix Composites (CMCs are anticipated for use in the hot section of aircraft engines. Their implementation requires the understanding of the various damage modes that are involved and their relation to life expectancy. Acoustic Emission (AE has been shown to be an efficient technique for monitoring damage evolution in CMCs. However, only a waveform-based analysis of AE can offer the possibility to validate and precisely examine the recorded AE data with a view to damage localization and identification. The present work fully integrates wave initiation, propagation and acquisition in the analysis of Acoustic Emission waveforms recorded at various sensors, therefore providing more reliable information to assess the relation between Acoustic Emission and damage modes. The procedure allows selecting AE events originating from damage, accurate determination of their location as well as the characterization of effects of propagation on the recorded waveforms. This approach was developed using AE data recorded during tensile tests on carbon/carbon composites. It was then applied to melt-infiltrated SiC/SiC composites.

  14. Effective beam pattern of the Blainville's beaked whale (Mesoplodon densirostris) and implications for passive acoustic monitoring.

    Science.gov (United States)

    Shaffer, Jessica Ward; Moretti, David; Jarvis, Susan; Tyack, Peter; Johnson, Mark

    2013-03-01

    The presence of beaked whales in mass-strandings coincident with navy maneuvers has prompted the development of methods to detect these cryptic animals. Blainville's beaked whales, Mesoplodon densirostris, produce distinctive echolocation clicks during long foraging dives making passive acoustic detection a possibility. However, performance of passive acoustic monitoring depends upon the source level, beam pattern, and clicking behavior of the whales. In this study, clicks recorded from Digital acoustic Tags (DTags) attached to four M. densirostris were linked to simultaneous recordings from an 82-hydrophone bottom-mounted array to derive the source level and beam pattern of the clicks, as steps towards estimating their detectability. The mean estimated on-axis apparent source level for the four whales was 201 dBrms97. The mean 3 dB beamwidth and directivity index, estimated from sequences of clicks directed towards the far-field hydrophones, were 13° and 23 dB, respectively. While searching for prey, Blainville's beaked whales scan their heads horizontally at a mean rate of 3.6°/s over an angular range of some +/-10°. Thus, while the DI indicates a narrow beam, the area of ensonification over a complete foraging dive is large given the combined effects of body and head movements associated with foraging.

  15. Laser ablation of absorbing liquids under transparent cover: acoustical and optical monitoring

    Science.gov (United States)

    Samokhin, A. A.; Il'ichev, N. N.; Pivovarov, P. A.; Sidorin, A. V.

    2016-06-01

    Phase transition induced with infrared (λ = 2920 nm and λ = 2940 nm) nanosecond laser pulses in strongly absorbing liquids (water, ethanol) under transparent solid cover is investigated with the help of acoustical and optical monitoring. LiNbO3 transducer is used for registration of pressure pulses generated in irradiated liquids. Optical signals due to scattering and specular reflection of probing optical beams are explored with the schemes involving total internal reflection and interference effects. Combination of these two optical diagnostic methods permits for the first time to show that irradiation of covered liquids leads to vapor cavity formation which is divided from the cover with thin (submicron) liquid film despite the fact that radiation intensity maximum is located just at the liquid-plate boundary. The cavity formation is due to explosive boiling which occurs when the superheated liquid reaches its superheating limit in near critical region. After the first acoustical signal, the second signal is observed with several hundreds microseconds time delay which is caused by the vapor cavity collapse. Some results of optical and acoustical diagnostics in the case of free liquid surface are also presented.

  16. Acoustic monitoring of laboratory faults: locating the origin of unstable slip events

    Science.gov (United States)

    Korkolis, Evangelos; Niemeijer, André; Spiers, Christopher

    2015-04-01

    Over the past several decades, much work has been done on studying the frictional properties of fault gouges at earthquake nucleation velocities. In addition, post-experiment microstructural analyses have been performed in an attempt to link microphysical mechanisms to the observed mechanical data. However, all observations are necessarily post-mortem and it is thus difficult to directly link transients to microstructural characteristics. We are developing an acoustic monitoring system to be used in sliding experiments using a ring shear apparatus. The goal is to locate acoustic emission sources in sheared granular assemblages and link them to processes that act on microstructures responsible for the frictional stability of the simulated fault gouge. The results will be used to develop and constrain microphysical models that explain the relation of these processes to empirical friction laws, such as rate- and state-dependent friction. The acoustic monitoring setup is comprised of an array of 16 piezo-electric sensors installed on the top and bottom sides of an annular sample, at 45 degree intervals. Acoustic emissions associated with slip events can be recorded at sampling rates of up to 50 MHz, in triggered mode. Initial experiments on 0.1 to 0.2 mm and 0.4 to 0.5 mm diameter glass beads, at 1 to 5 MPa normal stress and 1 to 30 um/s load point velocity, have been conducted to estimate the sensitivity of the sensor array. Preliminary results reveal that the intensity of the audible signal is not necessarily proportional to the magnitude of the associated stress drop for constant loading conditions, and that acoustic emissions precede slip events by a small amount of time, in the order of a few milliseconds. Currently, our efforts are focused on developing a suitable source location algorithm with the aim to identify differences in the mode of (unstable) sliding for different types of materials. This will help to identify the micromechanical mechanisms operating

  17. Near-real-time acoustic monitoring of beaked whales and other cetaceans using a Seaglider™.

    Directory of Open Access Journals (Sweden)

    Holger Klinck

    Full Text Available In most areas, estimating the presence and distribution of cryptic marine mammal species, such as beaked whales, is extremely difficult using traditional observational techniques such as ship-based visual line transect surveys. Because acoustic methods permit detection of animals underwater, at night, and in poor weather conditions, passive acoustic observation has been used increasingly often over the last decade to study marine mammal distribution, abundance, and movements, as well as for mitigation of potentially harmful anthropogenic effects. However, there is demand for new, cost-effective tools that allow scientists to monitor areas of interest autonomously with high temporal and spatial resolution in near-real time. Here we describe an autonomous underwater vehicle--a glider--equipped with an acoustic sensor and onboard data processing capabilities to passively scan an area for marine mammals in near-real time. The glider was tested extensively off the west coast of the Island of Hawai'i, USA. The instrument covered approximately 390 km during three weeks at sea and collected a total of 194 h of acoustic data. Detections of beaked whales were successfully reported to shore in near-real time. Manual analysis of the recorded data revealed a high number of vocalizations of delphinids and sperm whales. Furthermore, the glider collected vocalizations of unknown origin very similar to those made by known species of beaked whales. The instrument developed here can be used to cost-effectively screen areas of interest for marine mammals for several months at a time. The near-real-time detection and reporting capabilities of the glider can help to protect marine mammals during potentially harmful anthropogenic activities such as seismic exploration for sub-sea fossil fuels or naval sonar exercises. Furthermore, the glider is capable of under-ice operation, allowing investigation of otherwise inaccessible polar environments that are critical

  18. Near-real-time acoustic monitoring of beaked whales and other cetaceans using a Seaglider™.

    Science.gov (United States)

    Klinck, Holger; Mellinger, David K; Klinck, Karolin; Bogue, Neil M; Luby, James C; Jump, William A; Shilling, Geoffrey B; Litchendorf, Trina; Wood, Angela S; Schorr, Gregory S; Baird, Robin W

    2012-01-01

    In most areas, estimating the presence and distribution of cryptic marine mammal species, such as beaked whales, is extremely difficult using traditional observational techniques such as ship-based visual line transect surveys. Because acoustic methods permit detection of animals underwater, at night, and in poor weather conditions, passive acoustic observation has been used increasingly often over the last decade to study marine mammal distribution, abundance, and movements, as well as for mitigation of potentially harmful anthropogenic effects. However, there is demand for new, cost-effective tools that allow scientists to monitor areas of interest autonomously with high temporal and spatial resolution in near-real time. Here we describe an autonomous underwater vehicle--a glider--equipped with an acoustic sensor and onboard data processing capabilities to passively scan an area for marine mammals in near-real time. The glider was tested extensively off the west coast of the Island of Hawai'i, USA. The instrument covered approximately 390 km during three weeks at sea and collected a total of 194 h of acoustic data. Detections of beaked whales were successfully reported to shore in near-real time. Manual analysis of the recorded data revealed a high number of vocalizations of delphinids and sperm whales. Furthermore, the glider collected vocalizations of unknown origin very similar to those made by known species of beaked whales. The instrument developed here can be used to cost-effectively screen areas of interest for marine mammals for several months at a time. The near-real-time detection and reporting capabilities of the glider can help to protect marine mammals during potentially harmful anthropogenic activities such as seismic exploration for sub-sea fossil fuels or naval sonar exercises. Furthermore, the glider is capable of under-ice operation, allowing investigation of otherwise inaccessible polar environments that are critical habitats for many

  19. Use of Acoustic Emission to Monitor Progressive Damage Accumulation in Kevlar (R) 49 Composites

    Science.gov (United States)

    Waller, Jess M.; Saulsberry, Regor L.; Andrade, Eduardo

    2009-01-01

    Acoustic emission (AE) data acquired during intermittent load hold tensile testing of epoxy impregnated Kevlar(Registeres TradeMark) 49 (K/Ep) composite strands were analyzed to monitor progressive damage during the approach to tensile failure. Insight into the progressive damage of K/Ep strands was gained by monitoring AE event rate and energy. Source location based on energy attenuation and arrival time data was used to discern between significant AE attributable to microstructural damage and spurious AE attributable to noise. One of the significant findings was the observation of increasing violation of the Kaiser effect (Felicity ratio < 1.0) with damage accumulation. The efficacy of three different intermittent load hold stress schedules that allowed the Felicity ratio to be determined analytically is discussed.

  20. Structural Health Monitoring of Wind Turbine Blades: Acoustic Source Localization Using Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Omar Mabrok Bouzid

    2015-01-01

    Full Text Available Structural health monitoring (SHM is important for reducing the maintenance and operation cost of safety-critical components and systems in offshore wind turbines. This paper proposes an in situ wireless SHM system based on an acoustic emission (AE technique. By using this technique a number of challenges are introduced due to high sampling rate requirements, limitations in the communication bandwidth, memory space, and power resources. To overcome these challenges, this paper focused on two elements: (1 the use of an in situ wireless SHM technique in conjunction with the utilization of low sampling rates; (2 localization of acoustic sources which could emulate impact damage or audible cracks caused by different objects, such as tools, bird strikes, or strong hail, all of which represent abrupt AE events and could affect the structural health of a monitored wind turbine blade. The localization process is performed using features extracted from aliased AE signals based on a developed constraint localization model. To validate the performance of these elements, the proposed system was tested by testing the localization of the emulated AE sources acquired in the field.

  1. Preliminary studies for monitoring erosion in pipelines by the acoustic emission technique

    Energy Technology Data Exchange (ETDEWEB)

    Tiboni, G.B. [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil). Programa de Pos-graduacao em Engenharia Mecanica e de Materiais; Marquardt, T.A.S; SantaMaria, V.A.R.; Silva, C.H. [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil)

    2009-07-01

    The aim of this work is to present some applications of Acoustic Emission (AE), which is a powerful technique for nondestructive testing in Tribology, treated here as tests of friction, wear by contact fatigue, wear by slip and wear by erosion. In this work a special attention is given to solid particle erosion and hydro-abrasive erosion, problems found in almost every pipeline that lead to local loss of material and eventually rupture of the line. The technique of AE can be used as an efficient online tool when, primarily, to monitor tribological aspects such as the rate of wear of materials, as well as detect the spread of flaws in them. In wear by erosion, specifically, the parameters of RMS and acoustic energy are capable of correlation with the type of mechanism for removal of material. As a preliminary goal, erosive tests were performed with gas (air) without erosive particles, monitored by AE, varying the surface of the samples and the internal diameter the nozzle, taking the differences in signs of AE. Correlation between parameters of RMS and amplitude were noticed with the variables of the tests, such as roughness and fluid velocity. The RMS parameter showed a exponential correction with the fluid velocity, however the amplitude signals had a linear behavior. The knowledge of these parameters is essential for the development of a system that is able to quantify the wear rate of a pipeline without taking it out of operation. (author)

  2. Monitoring of martensite formation during welding by means of acoustic emission

    Energy Technology Data Exchange (ETDEWEB)

    Bohemen, S.M.C. van; Hermans, M.J.M.; Ouden, G. den [Netherlands Institute for Metals Research, Delft University of Technology, Delft (Netherlands)

    2001-11-21

    The martensitic transformation during gas tungsten arc (GTA) welding of steel 42CrMo4 has been studied using the acoustic emission (AE) monitoring technique. Welds were produced under static conditions (spot welding) and under stationary conditions (travelling arc welding). After spot welding, the root mean square (RMS) value of the continuous acoustic emission was measured, revealing a peak that reflects the evolution of martensite formation during cooling of the spot weld. The RMS value was also measured during travelling arc welding at different heat inputs and corrected for the noise of the welding process to obtain the RMS value due to martensite formation. After welding, optical metallography was carried out to quantify the amount of martensite formed during cooling of the weld. An analysis of the results shows that the squared RMS value is proportional to the volume rate of martensite formation during welding, which is consistent with theory and in good agreement with the results obtained in the case of spot welding. The obtained results suggest that AE can be applied as a real time monitoring technique for the detection of martensite formation during steel welding. (author)

  3. Acoustic emission-based condition monitoring methods: Review and application for low speed slew bearing

    Science.gov (United States)

    Caesarendra, Wahyu; Kosasih, Buyung; Tieu, Anh Kiet; Zhu, Hongtao; Moodie, Craig A. S.; Zhu, Qiang

    2016-05-01

    This paper presents an acoustic emission-based method for the condition monitoring of low speed reversible slew bearings. Several acoustic emission (AE) hit parameters as the monitoring parameters for the detection of impending failure of slew bearings are reviewed first. The review focuses on: (1) the application of AE in typical rolling element bearings running at different speed classifications, i.e. high speed (>600 rpm), low speed (10-600 rpm) and very low speed (<10 rpm); (2) the commonly used AE hit parameters in rolling element bearings and (3) AE signal processing, feature extraction and pattern recognition methods. In the experiment, impending failure of the slew bearing was detected by the AE hit parameters after the new bearing had run continuously for approximately 15 months. The slew bearing was then dismantled and the evidence of the early defect was analysed. Based on the result, we propose a feature extraction method of the AE waveform signal using the largest Lyapunov exponent (LLE) algorithm and demonstrate that the LLE feature can detect the sign of failure earlier than the AE hit parameters with improved prediction of the progressive trend of the defect.

  4. Monitoring accelerated carbonation on standard Portland cement mortar by nonlinear resonance acoustic test

    Science.gov (United States)

    Eiras, J. N.; Kundu, T.; Popovics, J. S.; Monzó, J.; Borrachero, M. V.; Payá, J.

    2015-03-01

    Carbonation is an important deleterious process for concrete structures. Carbonation begins when carbon dioxide (CO2) present in the atmosphere reacts with portlandite producing calcium carbonate (CaCO3). In severe carbonation conditions, C-S-H gel is decomposed into silica gel (SiO2.nH2O) and CaCO3. As a result, concrete pore water pH decreases (usually below 10) and eventually steel reinforcing bars become unprotected from corrosion agents. Usually, the carbonation of the cementing matrix reduces the porosity, because CaCO3 crystals (calcite and vaterite) occupy more volume than portlandite. In this study, an accelerated carbonation-ageing process is conducted on Portland cement mortar samples with water to cement ratio of 0.5. The evolution of the carbonation process on mortar is monitored at different levels of ageing until the mortar is almost fully carbonated. A nondestructive technique based on nonlinear acoustic resonance is used to monitor the variation of the constitutive properties upon carbonation. At selected levels of ageing, the compressive strength is obtained. From fractured surfaces the depth of carbonation is determined with phenolphthalein solution. An image analysis of the fractured surfaces is used to quantify the depth of carbonation. The results from resonant acoustic tests revealed a progressive increase of stiffness and a decrease of material nonlinearity.

  5. Laser tattoo removal as an ablation process monitored by acoustical and optical methods

    Science.gov (United States)

    Cencič, Boris; Gregorčič, Peter; Možina, Janez; Jezeršek, Matija

    2013-07-01

    Strength of the laser-tissue interaction varies even within a single tattoo because of the inhomogeneous distribution of the tattoo pigment embedded in the skin. A monitoring system is therefore developed for simultaneous monitoring of the laser tattoo removal process based on acoustical and optical techniques. A laser-beam-deflection probe is used for measuring the acoustical signals accompanying the breakdown, and a CCD camera captures the level and the spatial distribution of the plasma radiation. Using these methods we examine the degree of excitation-pulse absorption within the pigment and the degree of the structural changes of the skin. A Nd:YAG laser with a top-hat beam profile, designed for tattoo removal, is used as the excitation source in our experiments. Special attention is given to structural changes in the skin, which depend on the applied fluence. Tattoo removal with multiple pulses is also analyzed. Experiments are made in vitro (skin phantoms) and ex vivo (marking tattoos on the pig skin). The presented results are important for the understanding and optimization of the process used in medical therapies.

  6. Use of large-scale acoustic monitoring to assess anthropogenic pressures on Orthoptera communities.

    Science.gov (United States)

    Penone, Caterina; Le Viol, Isabelle; Pellissier, Vincent; Julien, Jean-François; Bas, Yves; Kerbiriou, Christian

    2013-10-01

    Biodiversity monitoring at large spatial and temporal scales is greatly needed in the context of global changes. Although insects are a species-rich group and are important for ecosystem functioning, they have been largely neglected in conservation studies and policies, mainly due to technical and methodological constraints. Sound detection, a nondestructive method, is easily applied within a citizen-science framework and could be an interesting solution for insect monitoring. However, it has not yet been tested at a large scale. We assessed the value of a citizen-science program in which Orthoptera species (Tettigoniidae) were monitored acoustically along roads. We used Bayesian model-averaging analyses to test whether we could detect widely known patterns of anthropogenic effects on insects, such as the negative effects of urbanization or intensive agriculture on Orthoptera populations and communities. We also examined site-abundance correlations between years and estimated the biases in species detection to evaluate and improve the protocol. Urbanization and intensive agricultural landscapes negatively affected Orthoptera species richness, diversity, and abundance. This finding is consistent with results of previous studies of Orthoptera, vertebrates, carabids, and butterflies. The average mass of communities decreased as urbanization increased. The dispersal ability of communities increased as the percentage of agricultural land and, to a lesser extent, urban area increased. Despite changes in abundances over time, we found significant correlations between yearly abundances. We identified biases linked to the protocol (e.g., car speed or temperature) that can be accounted for ease in analyses. We argue that acoustic monitoring of Orthoptera along roads offers several advantages for assessing Orthoptera biodiversity at large spatial and temporal extents, particularly in a citizen science framework. © 2013 Society for Conservation Biology.

  7. Real-time monitoring of controllable cavitation erosion in a vessel phantom with passive acoustic mapping.

    Science.gov (United States)

    Lu, Shukuan; Shi, Aiwei; Jing, Bowen; Du, Xuan; Wan, Mingxi

    2017-11-01

    Cavitation erosion in blood vessel plays an important role in ultrasound thrombolysis, drug delivery, and other clinical applications. The controllable superficial vessel erosion based on ultrasonic standing wave (USW) has been used to effectively prevent vessel ruptures and haemorrhages, and optical method is used to observe the experiments. But optical method can only work in transparent media. Compared with standard B-mode imaging, passive acoustic mapping (PAM) can monitor erosion in real time and has better sensitivity of cavitation detection. However, the conventionally used PAM has limitations in imaging resolution and artifacts. In this study, a unique PAM method that combined the robust Capon beamformer (RCB) with the sign coherence factor (SCF) was proposed to monitor the superficial vessel erosion in real time. The performance of the proposed method was validated by simulations. In vitro experiments showed that the lateral (axial) resolution of the proposed PAM was 2.31±0.51 (3.19±0.38) times higher than time exposure acoustics (TEA)-based PAM and 1.73±0.38 (1.76±0.48) times higher than RCB-based PAM, and the cavitation-to-artifact ratio (CAR) of the proposed PAM could be improved by 22.5±3.2dB and 7.1±1.2dB compared with TEA and RCB-based PAM. These results showed that the proposed PAM can precisely monitor the superficial vessel erosion and the erosion shift after USW modulation. This work may have the potential of developing a useful tool for precise spatial control and real-time monitoring of the superficial vessel erosion. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Seismic and Acoustic Array Monitoring of Signal from Tungurahua Volcano, Ecuador

    Science.gov (United States)

    Terbush, B. R.; Anthony, R. E.; Johnson, J. B.; Ruiz, M. C.

    2012-12-01

    Tungurahua Volcano is an active stratovolcano located in Ecuador's eastern Cordillera. Since its most recent cycle of eruptive activity, beginning in 1999, it has produced both strombolian-to-vulcanian eruptions, and regular vapor emissions. Tungurahua is located above the city of Baños, so volcanic activity is well-monitored by Ecuador's Instituto Geofisico Nacional with a seismic and infrasound network, and other surveillance tools. Toward better understanding of the complex seismic and acoustic signals associated with low-level Tungurahua activity, and which are often low in signal-to-noise, we deployed temporary seismo-acoustic arrays between June 9th and 20th in 2012. This deployment was part of a Field Volcano Geophysics class, a collaboration between New Mexico Institute of Mining and Technology and the Escuela Politecnica Nacional's Instituto Geofísico in Ecuador. Two six-element arrays were deployed on the flank of the volcano. A seismo-acoustic array, which consisted of combined broadband seismic and infrasound sensors, possessed 100-meter spacing, and was deployed five kilometers north of the vent in an open field at 2700 m. The second array had only acoustic sensors with 30-meter spacing, and was deployed approximately six kilometers northwest of the vent, on an old pyroclastic flow deposit. The arrays picked up signals from four distinct explosion events, a number of diverse tremor signals, local volcano tectonic and long period earthquakes, and a regional tectonic event of magnitude 4.9. Coherency of both seismic and acoustic array data was quantified using Fisher Statistics, which was effective for identifying myriad signals. For most signals Fisher Statistics were particularly high in low frequency bands, between 0.5 and 2 Hz. Array analyses helped to filter out noise induced by cultural sources and livestock signals, which were particularly pronounced in the deployment site. Volcan Tungurahua sources were considered plane wave signals and could

  9. Variation in harbour seal (Phoca vitulina L.) roar calls among recoding sites relevant for passive acoustic monitoring

    DEFF Research Database (Denmark)

    Sabinsky, Puk; Larsen, Ole Næsbye; Wahlberg, Magnus

    2017-01-01

    Male harbor seals gather around breeding sites for competitive mating displays. Here, they produce underwater vocalizations possibly to attract females and/or scare off other males. These calls offer prospects for passive acoustic monitoring. Acoustic monitoring requires a good understanding...... of natural variation in calling behavior both temporally and among geographically separate sites. Such variation in call structure and calling patterns were studied in harbor seal vocalizations recorded at three locations in Danish and Swedish waters. There was a strong seasonality in the calls from end...

  10. An effective sensor for tool wear monitoring in face milling: Acoustic emission

    Indian Academy of Sciences (India)

    M T Mathew; P Srinivasa Pai; L A Rocha

    2008-06-01

    Acoustic Emission (AE) has been widely used for monitoring manufacturing processes particularly those involving metal cutting. Monitoring the condition of the cutting tool in the machining process is very important since tool condition will affect the part size, quality and an unexpected tool failure may damage the tool, work-piece and sometimes the machine tool itself. AE can be effectively used for tool condition monitoring applications because the emissions from process changes like tool wear, chip formation i.e. plastic deformation, etc. can be directly related to the mechanics of the process. Also AE can very effectively respond to changes like tool fracture, tool chipping, etc. when compared to cutting force and since the frequency range is much higher than that of machine vibrations and environmental noises, a relatively uncontaminated signal can be obtained. AE signal analysis was applied for sensing tool wear in face milling operations. Cutting tests were carried out on a vertical milling machine. Tests were carried out for a given cutting condition, using single insert, two inserts (adjacent and opposite) and three inserts in the cutter. AE signal parameters like ring down count and rms voltage were measured and were correlated with flank wear values (VB max). The results of this investigation indicate that AE can be effectively used for monitoring tool wear in face milling operations.

  11. Research on the Monitoring System of CNC Grinding Process Based on Acoustic Emission

    Institute of Scientific and Technical Information of China (English)

    HU Zhongxiang; TENG Jiaxu; YANG Junwei; HUO Xiaojing; SHI Xiaojun

    2006-01-01

    Using on-line monitoring during the CNC grinding process, the hazard case such as the crushing of grinding wheel and various safety accidents could be avoided, and the optimum time for dressing and replacing grinding wheel could also be determined, and hence, the service life of the grinding wheel could be prolonged and grinding quality could be improved. To overcome the limitation of some traditional techniques in which some parameters including the grinding power and force, torque and so on were monitored, the acoustic emission (AE) technique, which provides high sensitivity and responding speed, were developed in the present paper. The mechanism of AE during grinding was reviewed. Moreover, a virtual AE monitoring system, which could monitor the grinding state under different working conditions during the grinding, has been developed based on the Virtual Instruments technique. Some experiments were also performed on the internal grinder. The results showed that the AE signals became stronger with increasing the main shaft speed and grinding depth or decreasing the distance between the AE sensor and grinding area.

  12. A multi path, weather independent avalanche monitoring tool using distributed acoustic fiber optic sensing

    Science.gov (United States)

    Prokop, Alexander; Wirbel, Anna

    2013-04-01

    Information on avalanche activity is a paramount parameter in avalanche forecasting. When avalanches are released spontaneously, the risk of avalanches is very high. Triggering avalanches by artificial means, such as explosives launched from helicopter or avalanche towers, can also give information on the stability of the snow pack. Hence, monitoring of avalanches released naturally or artificially, is an important quantity in avalanche forecasting. This information is also needed when deciding whether to close or not endangered ski runs, roads or railway lines. So far monitoring systems lack certain benefits. Either they monitor only large avalanches, can only be used for single avalanche tracks or are weather/sight dependant. Therefore a new tool for avalanche- monitoring, a distributed fiber optic system, is for the first time installed and adapted for the purpose of monitoring snow avalanche activity. The method is based on an optical time domain reflectometer (OTDR) system, which dates back to the 1970`s and detects seismic vibrations and acoustic signals on a fiber optic cable that can have a length of up to 30 km. An appropriate test slope for this configuration has been found in the ski area of "Lech am Arlberg". In this work a detailed description of the theoretical background, the system implementation, the field installation, realization of tests and an investigation of the recorded data is presented. We conducted 100 tests and triggered 41 avalanches so far with a runout distances ranging from a few meters to approximately 250 meters, all of which were detected by the system, as well as the 59 not successful attempts of artificial triggering. Moreover we measured properly if critical infrastructure (in our case a ski run) was reached by the avalanches or not. The spatial distributed sensing approach allowed us to relate the amplitude and spectral content of the signals to avalanche size, avalanche speed and snow properties of the avalanches. In

  13. Estimating population size of a nocturnal burrow-nesting seabird using acoustic monitoring and habitat mapping

    Directory of Open Access Journals (Sweden)

    Steffen Oppel

    2014-04-01

    Full Text Available Population size assessments for nocturnal burrow-nesting seabirds are logistically challenging because these species are active in colonies only during darkness and often nest on remote islands where manual inspections of breeding burrows are not feasible. Many seabird species are highly vocal, and recent technological innovations now make it possible to record and quantify vocal activity in seabird colonies. Here we test the hypothesis that remotely recorded vocal activity in Cory’s shearwater (Calonectris borealis breeding colonies in the North Atlantic increases with nest density, and combined this relationship with cliff habitat mapping to estimate the population size of Cory’s shearwaters on the island of Corvo (Azores. We deployed acoustic recording devices in 9 Cory’s shearwater colonies of known size to establish a relationship between vocal activity and local nest density (slope = 1.07, R2 = 0.86, p < 0.001. We used this relationship to predict the nest density in various cliff habitat types and produced a habitat map of breeding cliffs to extrapolate nest density around the island of Corvo. The mean predicted nest density on Corvo ranged from 6.6 (2.1–16.2 to 27.8 (19.5–36.4 nests/ha. Extrapolation of habitat-specific nest densities across the cliff area of Corvo resulted in an estimate of 6326 Cory’s shearwater nests (95% confidence interval: 3735–10,524. This population size estimate is similar to previous assessments, but is too imprecise to detect moderate changes in population size over time. While estimating absolute population size from acoustic recordings may not be sufficiently precise, the strong positive relationship that we found between local nest density and recorded calling rate indicates that passive acoustic monitoring may be useful to document relative changes in seabird populations over time.

  14. Final Report: Guided Acoustic Wave Monitoring of Corrosion in Recovery Boiler Tubing

    Energy Technology Data Exchange (ETDEWEB)

    Chinn, D J; Quarry, M J; Rose, J L

    2005-03-31

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

  15. Monitoring and Failure Analysis of Corroded Bridge Cables under Fatigue Loading Using Acoustic Emission Sensors

    Directory of Open Access Journals (Sweden)

    Hui Li

    2012-03-01

    Full Text Available Cables play an important role in cable-stayed systems, but are vulnerable to corrosion and fatigue damage. There is a dearth of studies on the fatigue damage evolution of corroded cable. In the present study, the acoustic emission (AE technology is adopted to monitor the fatigue damage evolution process. First, the relationship between stress and strain is determined through a tensile test for corroded and non-corroded steel wires. Results show that the mechanical performance of corroded cables is changed considerably. The AE characteristic parameters for fatigue damage are then established. AE energy cumulative parameters can accurately describe the fatigue damage evolution of corroded cables. The failure modes in each phase as well as the type of acoustic emission source are determined based on the results of scanning electron microscopy. The waveform characteristics, damage types, and frequency distribution of the corroded cable at different damage phases are collected. Finally, the number of broken wires and breakage time of the cables are determined according to the variation in the margin index.

  16. Electrical Resistance and Acoustic Emission Measurements for Monitoring the Structural Behavior of CFRP Laminate

    KAUST Repository

    Zhou, Wei

    2015-07-12

    Electrical resistance and acoustic emission (AE) measurement are jointly used to monitor the degradation in CFRP laminates subjected to tensile tests. The objective of this thesis is to perform a synergertic analysis between a passive and an active methods to better access how these perform when used for Structural Health Moni- toring (SHM). Laminates with three different stacking sequences: [0]4, [02/902]s and [+45/ − 45]2s are subjected to monotonic and cyclic tensile tests. In each laminate, we carefully investigate which mechanisms of degradation can or cannot be detect- ed by each technique. It is shown that most often, that acoustic emission signals start before any electrical detection is possible. This is is explained based on the redundance of the electrical network that makes it less sensitive to localized damages. Based on in depth study of AE signals clustering, a new classification is proposed to recognize the different damage mechanims based on only two parameters: the RA (rise time/amplitude) and the duration of the signal.

  17. Continuous wide area monitoring of fish shoaling behavior with acoustic waveguide sensing and bioclutter implications

    Science.gov (United States)

    Makris, Nicholas C.; Ratilal, Purnima; Symonds, Deanelle T.; Nero, Redwood W.

    2001-05-01

    Field measurements are used to show that the detailed behavior of fish shoals can be continuously monitored at roughly 1-min intervals over wide areas spanning hundreds of square kilometers by long range acoustic waveguide sensing. The technique was used on the New Jersey Continental Shelf to produce unprecedented video images of shoal formation, fragmentation, and migration. Simultaneous line-transect measurements show the imaged shoals to contain pelagic fish with densities of at least one individual per meter3. The technique relies upon acoustic waveguide propagation in the continental shelf. Here, trapped modes dominate propagation and suffer only cylindrical spreading loss rather than the spherical loss suffered in free-space transmission or short-range propagation in the ocean. In contrast, standard methods for fish surveyance involve line transect measurements from slow moving research vessels that significantly under-sample fish distributions in time and space, leaving an incomplete behavioral picture. The implications of this bioclutter phenomenon on the Navy's long range active sonar operations in continental shelf environments are discussed.

  18. Monitoring and failure analysis of corroded bridge cables under fatigue loading using acoustic emission sensors.

    Science.gov (United States)

    Li, Dongsheng; Ou, Jinping; Lan, Chengming; Li, Hui

    2012-01-01

    Cables play an important role in cable-stayed systems, but are vulnerable to corrosion and fatigue damage. There is a dearth of studies on the fatigue damage evolution of corroded cable. In the present study, the acoustic emission (AE) technology is adopted to monitor the fatigue damage evolution process. First, the relationship between stress and strain is determined through a tensile test for corroded and non-corroded steel wires. Results show that the mechanical performance of corroded cables is changed considerably. The AE characteristic parameters for fatigue damage are then established. AE energy cumulative parameters can accurately describe the fatigue damage evolution of corroded cables. The failure modes in each phase as well as the type of acoustic emission source are determined based on the results of scanning electron microscopy. The waveform characteristics, damage types, and frequency distribution of the corroded cable at different damage phases are collected. Finally, the number of broken wires and breakage time of the cables are determined according to the variation in the margin index.

  19. Passive wireless surface acoustic wave sensors for monitoring sequestration sites CO2 emission

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yizhong [Univ. of Pittsburgh, PA (United States); Chyu, Minking [Univ. of Pittsburgh, PA (United States); Wang, Qing-Ming [Univ. of Pittsburgh, PA (United States)

    2013-02-14

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

  20. A Methodological Review of Piezoelectric Based Acoustic Wave Generation and Detection Techniques for Structural Health Monitoring

    Directory of Open Access Journals (Sweden)

    Zhigang Sun

    2013-01-01

    Full Text Available Piezoelectric transducers have a long history of applications in nondestructive evaluation of material and structure integrity owing to their ability of transforming mechanical energy to electrical energy and vice versa. As condition based maintenance has emerged as a valuable approach to enhancing continued aircraft airworthiness while reducing the life cycle cost, its enabling structural health monitoring (SHM technologies capable of providing on-demand diagnosis of the structure without interrupting the aircraft operation are attracting increasing R&D efforts. Piezoelectric transducers play an essential role in these endeavors. This paper is set forth to review a variety of ingenious ways in which piezoelectric transducers are used in today’s SHM technologies as a means of generation and/or detection of diagnostic acoustic waves.

  1. Acoustic Monitoring of a Previously Unstudied Whale Shark Aggregation in the Red Sea

    KAUST Repository

    Cochran, Jesse

    2012-01-01

    The whale shark (Rhincodon, typus), is a large, pelagic, filter feeder for which the available information is limited. The Red Sea populations in particular are practically unstudied. An aggregation site was recently discovered off the western coast of Saudi Arabia. We report the use of passive acoustic monitoring to assess the spatial and temporal behavior patterns of whale sharks in this new site. The aggregation occurs in the spring and peaks in April/ May. Whale sharks showed a preference for a single near shore reef and even a specific area within it. There is no evidence of sexual segregation as the genders were present in roughly equal proportion and used the same habitat at similar times. This information can be used to guide future studies in the area and to inform local management. Continued study will add to the collective knowledge on Red Sea whale sharks, including the population dynamics within the region and how they interact with the global whale shark community.

  2. Simultaneous surface acoustic wave and surface plasmon resonance measurements: Electrodeposition and biological interactions monitoring

    Science.gov (United States)

    Friedt, J.-M.; Francis, L.; Reekmans, G.; De Palma, R.; Campitelli, A.; Sleytr, U. B.

    2004-02-01

    We present results from an instrument combining surface acoustic wave propagation and surface plasmon resonance measurements. The objective is to use two independent methods, the former based on adsorbed mass change measurements and the latter on surface dielectric properties variations, to identify physical properties of protein layers, and more specifically their water content. We display mass sensitivity calibration curves using electrodeposition of copper leading to a sensitivity in liquid of 150±15 cm2/g for the Love mode device used here, and the application to monitoring biological processes. The extraction of protein layer thickness and protein to water content ratio is also presented for S-layer proteins under investigation. We obtain, respectively, 4.7±0.7 nm and 75±15%.

  3. Passive acoustic monitoring of toothed whales with implications for mitigation, management and biology

    DEFF Research Database (Denmark)

    Kyhn, Line Anker

    acoustic monitoring (PAM). PAM is particularly suited to study small inconspicuous for these species. Among the small odontocetes, four produce the same special echolocation click type, the narrow band high frequency (NBHF) click that has evolved through convergent evolution. Clicks of the individual NBHF...... pertaining to possible habitat specializations of each species as is seen for Microchiropteran bats and this was the focus of chapter IV & VI. It appeared that costal cluttered habitats may be limiting for NBHF species since they produce lower source levels when recorded in cluttered habitats and clutter...... is in accordance with new molecular phylogenies. In chapter I use the information I have gathered on spectral source properties as well as on source levels and directionality and use this information to challenge the theories for the evolution of the NBHF click type. I conclude that the NBHF signals likely evolved...

  4. Acoustic Emission Monitoring and Microscopic Investigation of Cracks in ERCuNi Cladding

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A corrosion resistant CuNi cladding was deposited on SM45C (equivalent to AI5I1045) substrate by DC inverse arcwelding. During the welding process, a three channel acoustic emission (AE) monitoring system was applied to detectthe crack signals generating from both the cladding process and after cladding. Characteristics of the welding cracksignal and noise signal had been analyzed systematically. Based on the record time of the signal, the solidificationcrack and delayed crack were distinguished. By two-dimensional AE source location, the crack position was located,and then investigated by scanning electron microscopy (SEM). Results showed that the AE system could detect thewelding crack with high sensitivity and the two-dimensional source location could accurately determine the crackposition. Microstructures of the cladding and heat affected zone (HAZ) were examined. Dendrites in the claddingand coarse grains in the HAZ were found.

  5. Acoustic telemetry validates a citizen science approach for monitoring sharks on coral reefs.

    Science.gov (United States)

    Vianna, Gabriel M S; Meekan, Mark G; Bornovski, Tova H; Meeuwig, Jessica J

    2014-01-01

    Citizen science is promoted as a simple and cost-effective alternative to traditional approaches for the monitoring of populations of marine megafauna. However, the reliability of datasets collected by these initiatives often remains poorly quantified. We compared datasets of shark counts collected by professional dive guides with acoustic telemetry data from tagged sharks collected at the same coral reef sites over a period of five years. There was a strong correlation between the number of grey reef sharks (Carcharhinus amblyrhynchos) observed by dive guides and the telemetry data at both daily and monthly intervals, suggesting that variation in relative abundance of sharks was detectable in datasets collected by dive guides in a similar manner to data derived from telemetry at these time scales. There was no correlation between the number or mean depth of sharks recorded by telemetry and the presence of tourist divers, suggesting that the behaviour of sharks was not affected by the presence of divers during our study. Data recorded by dive guides showed that current strength and temperature were important drivers of the relative abundance of sharks at monitored sites. Our study validates the use of datasets of shark abundance collected by professional dive guides in frequently-visited dive sites in Palau, and supports the participation of experienced recreational divers as contributors to long-term monitoring programs of shark populations.

  6. Passive acoustic monitoring of beaked whale densities in the Gulf of Mexico.

    Science.gov (United States)

    Hildebrand, John A; Baumann-Pickering, Simone; Frasier, Kaitlin E; Trickey, Jennifer S; Merkens, Karlina P; Wiggins, Sean M; McDonald, Mark A; Garrison, Lance P; Harris, Danielle; Marques, Tiago A; Thomas, Len

    2015-11-12

    Beaked whales are deep diving elusive animals, difficult to census with conventional visual surveys. Methods are presented for the density estimation of beaked whales, using passive acoustic monitoring data collected at sites in the Gulf of Mexico (GOM) from the period during and following the Deepwater Horizon oil spill (2010-2013). Beaked whale species detected include: Gervais' (Mesoplodon europaeus), Cuvier's (Ziphius cavirostris), Blainville's (Mesoplodon densirostris) and an unknown species of Mesoplodon sp. (designated as Beaked Whale Gulf - BWG). For Gervais' and Cuvier's beaked whales, we estimated weekly animal density using two methods, one based on the number of echolocation clicks, and another based on the detection of animal groups during 5 min time-bins. Density estimates derived from these two methods were in good general agreement. At two sites in the western GOM, Gervais' beaked whales were present throughout the monitoring period, but Cuvier's beaked whales were present only seasonally, with periods of low density during the summer and higher density in the winter. At an eastern GOM site, both Gervais' and Cuvier's beaked whales had a high density throughout the monitoring period.

  7. Effect of fiber orientation in uni-directional glass epoxy laminate using acoustic emission monitoring

    Institute of Scientific and Technical Information of China (English)

    V. Arumugam; S. Barath Kumar; C. Santulli; A. Joseph Stanley

    2011-01-01

    Acoustic emission (AE) can be used for in situ structural health monitoring of the composite laminates.One of the main issues of AE is to characterize different damage mechanisms from the detected AE signals.In the present work,pure resin and GFRP composites laminates with different stacking sequences such as 0°,90°,angle ply[±45°],cross-ply [0°/90°] are used to trigger different failure mechanisms when subjected to tensile test with AE monitoring.The study of failure mechanisms is facilitated by the choice of different oriented specimens in which one or two such mechanisms predominate.Range of peak frequencies in each orientation is investigated using FFT analysis.Fast Fourier Transform (FFT) enabled calculating the frequency content of each damage mechanism.Randomly selected hits from each range of peak frequencies for the specimens with different orientations subjected to tensile test with AE monitoring are analyzed using short time FFT (STFFT) analysis.STFFT analysis is used to highlight the possible failure mechanism associated with each signal.The predominance of failure modes in each orientation is useful in the study of discrimination of failure modes in composite laminates from AE data.

  8. Seasonal migrations of North Atlantic minke whales: novel insights from large-scale passive acoustic monitoring netsworks

    NARCIS (Netherlands)

    Risch, D.; Castellote, M.; Clark, C.W.; Lucke, K.; Verdaat, J.P.

    2014-01-01

    Background - Little is known about migration patterns and seasonal distribution away from coastal summer feeding habitats of many pelagic baleen whales. Recently, large-scale passive acoustic monitoring networks have become available to explore migration patterns and identify critical habitats of

  9. Seasonal migrations of North Atlantic minke whales: novel insights from large-scale passive acoustic monitoring netsworks

    NARCIS (Netherlands)

    Risch, D.; Castellote, M.; Clark, C.W.; Lucke, K.; Verdaat, J.P.

    2014-01-01

    Background - Little is known about migration patterns and seasonal distribution away from coastal summer feeding habitats of many pelagic baleen whales. Recently, large-scale passive acoustic monitoring networks have become available to explore migration patterns and identify critical habitats of th

  10. Spectroscopic and chemometric exploration of food quality

    DEFF Research Database (Denmark)

    Pedersen, Dorthe Kjær

    2002-01-01

    The desire to develop non-invasive rapid measurements of essential quality parameters in foods is the motivation of this thesis. Due to the speed and noninvasive properties of spectroscopic techniques, they have potential as on-line or atline methods and can be employed in the food industry...... in order to control the quality of the end product and to continuously monitor the production. In this thesis, the possibilities and limitations of the application of spectroscopy and chemometrics in rapid control of food quality are discussed and demonstrated by the examples in the eight included...... publications. Different aspects of food quality are covered, but the focus is mainly on the development of multivariate calibrations for predictions of rather complex attributes such as the water-holding capacity of meat, ethical quality of the slaughtering procedure, protein content of single wheat kernels...

  11. Remote erosion and corrosion monitoring of subsea pipelines using acoustic telemetry and wet-mate connector technology

    Energy Technology Data Exchange (ETDEWEB)

    Painter, Howard; Barlow, Stewart [Teledyne ODI, Thousand Oaks, CA (United States); Clarke, Daniel [Teledyne Cormon, Thousand Oaks, CA (United States); Green, Dale [Teledyne Benthos, North Falmouth, MA (United States)

    2009-07-01

    This paper will present a novel approach for monitoring erosion and corrosion using proven sub sea technologies: intrusive erosion and corrosion monitoring, acoustic telemetry and wet-mateable connector technology. Intrusive metal loss based monitoring systems on sub sea pipelines are increasingly being used because of their ability to directly measure erosion and corrosion. These systems are integrated with the sub sea production control system or located close to the platform and hard-wired. However, locations remote from a sub sea control system or platform requires a dedicated communication system and long lengths of cable that can be cost prohibitive to procure and install. The system presented consists of an intrusive erosion or corrosion monitor with pressure and temperature transmitters, a retrievable electronics module with an acoustic modem, a data storage module, and a replaceable power module. Time-stamped erosion and corrosion data can be transmitted via an acoustic link to a surface platform, a vessel of opportunity or to a relaying modem. Acoustic signals can be transmitted up to 6 km from the monitoring location. The power module along with data module and acoustic modem are mounted on the erosion and corrosion module using wet-mateable connectors, allowing retrieval by remotely operated vehicles. The collected data can be used to assess the cumulative erosion and corrosion as well as use the real-time metal loss rate data to correlate with operational parameters. Benefits include optimization of corrosion inhibitor dosage rates, mitigation of damage caused by solids production, and increased flow assurance. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-01-01

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

  13. Monitoring rock freezing and thawing by novel geoelectrical and acoustic techniques

    Science.gov (United States)

    Murton, Julian B.; Kuras, Oliver; Krautblatter, Michael; Cane, Tim; Tschofen, Dominique; Uhlemann, Sebastian; Schober, Sandra; Watson, Phil

    2016-12-01

    Automated monitoring of freeze-thaw cycles and fracture propagation in mountain rockwalls is needed to provide early warning about rockfall hazards. Conventional geoelectrical methods such as electrical resistivity tomography (ERT) are limited by large and variable ohmic contact resistances, requiring galvanic coupling with metal electrodes inserted into holes drilled into rock, and which can be loosened by rock weathering. We report a novel experimental methodology that combined capacitive resistivity imaging (CRI), ERT, and microseismic event recording to monitor freeze-thaw of six blocks of hard and soft limestones under conditions simulating an active layer above permafrost and seasonally frozen rock in a nonpermafrost environment. Our results demonstrate that the CRI method is highly sensitive to freeze-thaw processes; it yields property information equivalent to that obtained with conventional ERT and offers a viable route for nongalvanic long-term geoelectrical monitoring, extending the benefits of the methodology to soft/hard rock environments. Contact impedances achieved with CRI are less affected by seasonal temperature changes, the aggregate state of the pore water (liquid or frozen), and the presence of low-porosity rock with high matrix resistivities than those achieved with ERT. Microseismic monitoring has the advantage over acoustic emissions that events were recorded in relevant field distances of meters to decameters from cracking events. For the first time we recorded about 1000 microcracking events and clustered them in four groups according to frequency and waveform. Compared to previous studies, mainly on ice-cracking in glaciers, the groups are attributed to single- or multiple-stage cracking events such as crack coalescence.

  14. Calibrating passive acoustic monitoring: correcting humpback whale call detections for site-specific and time-dependent environmental characteristics.

    Science.gov (United States)

    Helble, Tyler A; D'Spain, Gerald L; Campbell, Greg S; Hildebrand, John A

    2013-11-01

    This paper demonstrates the importance of accounting for environmental effects on passive underwater acoustic monitoring results. The situation considered is the reduction in shipping off the California coast between 2008-2010 due to the recession and environmental legislation. The resulting variations in ocean noise change the probability of detecting marine mammal vocalizations. An acoustic model was used to calculate the time-varying probability of detecting humpback whale vocalizations under best-guess environmental conditions and varying noise. The uncorrected call counts suggest a diel pattern and an increase in calling over a two-year period; the corrected call counts show minimal evidence of these features.

  15. Clinical Studies of Real-Time Monitoring of Lithotripter Performance Using Passive Acoustic Sensors

    Science.gov (United States)

    Leighton, T. G.; Fedele, F.; Coleman, A. J.; McCarthy, C.; Ryves, S.; Hurrell, A. M.; De Stefano, A.; White, P. R.

    2008-09-01

    This paper describes the development and clinical testing of a passive device which monitors the passive acoustic emissions generated within the patient's body during Extracorporeal Shock Wave Lithotripsy (ESWL). Designed and clinically tested so that it can be operated by a nurse, the device analyses the echoes generated in the body in response to each ESWL shock, and so gives real time shock-by-shock feedback on whether the stone was at the focus of the lithotripter, and if so whether the previous shock contributed to stone fragmentation when that shock reached the focus. A shock is defined as being `effective' if these two conditions are satisfied. Not only can the device provide real-time feedback to the operator, but the trends in shock `effectiveness' can inform treatment. In particular, at any time during the treatment (once a statistically significant number of shocks have been delivered), the percentage of shocks which were `effective' provides a treatment score TS(t) which reflects the effectiveness of the treatment up to that point. The TS(t) figure is automatically delivered by the device without user intervention. Two clinical studies of the device were conducted, the ethics guidelines permitting only use of the value of TS(t) obtained at the end of treatment (this value is termed the treatment score TS0). The acoustically-derived treatment score was compared with the treatment score CTS2 given by the consultant urologist at the three-week patient's follow-up appointment. In the first clinical study (phase 1), records could be compared for 30 out of the 118 patients originally recruited, and the results of phase 1 were used to refine the parameter values (the `rules') with which the acoustic device provides its treatment score. These rules were tested in phase 2, for which records were compared for 49 of the 85 patients recruited. Considering just the phase 2 results (since the phase 1 data were used to draw up the `rules' under which phase 2 operated

  16. Acoustic monitoring on a humpback whale (Megaptera novaeangliae) feeding ground shows continual singing into late Spring.

    Science.gov (United States)

    Clark, Christopher W; Clapham, Phillip J

    2004-05-22

    Singing by males is a major feature of the mating system of humpback whales, Megaptera novaeangliae (Borowski). Although a few songs have been opportunistically recorded on the whales' high-latitude feeding grounds, singing in these regions was thought to be only sporadic. We report results from the first continuous acoustic monitoring of a humpback whale feeding ground (off Cape Cod, MA, USA) in spring. Using autonomous sea-floor recording systems, we found singing on a daily basis over the entire 25 day monitoring period, from 14 May to 7 June 2000. For much of the period, song was recorded 24 h per day. These results, combined with evidence for aseasonal conceptions in whaling catch data, suggest that the humpback whale breeding season should no longer be considered as confined to lower-latitude regions in winter. Rather, we suggest breeding extends geographically and temporally onto feeding grounds into at least spring and early summer. Singing at these times represents either low-cost opportunistic advertising by (perhaps relatively few) males to court females that failed to conceive during the winter, and/or possibly an intrasexual display.

  17. Acoustic emission detection with fiber optical sensors for dry cask storage health monitoring

    Science.gov (United States)

    Lin, Bin; Bao, Jingjing; Yu, Lingyu; Giurgiutiu, Victor

    2016-04-01

    The increasing number, size, and complexity of nuclear facilities deployed worldwide are increasing the need to maintain readiness and develop innovative sensing materials to monitor important to safety structures (ITS). In the past two decades, an extensive sensor technology development has been used for structural health monitoring (SHM). Technologies for the diagnosis and prognosis of a nuclear system, such as dry cask storage system (DCSS), can improve verification of the health of the structure that can eventually reduce the likelihood of inadvertently failure of a component. Fiber optical sensors have emerged as one of the major SHM technologies developed particularly for temperature and strain measurements. This paper presents the development of optical equipment that is suitable for ultrasonic guided wave detection for active SHM in the MHz range. An experimental study of using fiber Bragg grating (FBG) as acoustic emission (AE) sensors was performed on steel blocks. FBG have the advantage of being durable, lightweight, and easily embeddable into composite structures as well as being immune to electromagnetic interference and optically multiplexed. The temperature effect on the FBG sensors was also studied. A multi-channel FBG system was developed and compared with piezoelectric based AE system. The paper ends with conclusions and suggestions for further work.

  18. Acoustic emission monitoring of medieval towers considered as sensitive earthquake receptors

    Directory of Open Access Journals (Sweden)

    A. Carpinteri

    2007-01-01

    Full Text Available Many ancient masonry towers are present in Italian territory. In some cases these structures are at risk on account of the intensity of the stresses they are subjected to due to the high level of regional seismicity. In order to preserve this inestimable cultural heritage, a sound safety assessment should take into account the evolution of damage phenomena. In this connection, acoustic emission (AE monitoring can be highly effective. This study concerns the structural stability of three medieval towers rising in the centre of Alba, a characteristic town in Piedmont (Italy. During the monitoring period a correlation between peaks of AE activity in the masonry of these towers and regional seismicity was found. Earthquakes always affect structural stability. Besides that, the towers behaved as sensitive earthquake receptors. Here a method to correlate bursts of AE activity in a masonry building and regional seismicity is proposed. In particular, this method permits to identify the premonitory signals that precede a catastrophic event on a structure, since, in most cases, these warning signs can be captured well in advance.

  19. Acoustic monitoring in the Ross Sea, Antarctica, using hydrophone of the Ocean Bottom Seismometer

    Science.gov (United States)

    Yun, Sukyoung; Lee, Won Sang; Kuk Hong, Jong; Yoo, Hyun Jae; Park, Yongcheol; Schmidt-Aursch, Mechita; Geissler, Wolfram H.

    2016-04-01

    Although a number of active source seismic experiments have been conducted over the last few decades to investigate the crustal structure in the Ross Sea, Antarctica, long-term observation to monitor underwater tectonic activities and changes in the cryospheric environment still remains challenging due to existence of sea ice in the study region. Korea Polar Research Institute has accomplished successful deployment of ocean bottom seismometers (OBS) in the Ross Sea collaborating with Alfred Wegener Institute during the period of 2011-2012 and 2014 by Korean icebreaker RV Araon. The OBS system manufactured by K.U.M. contains a hydrophone sensor that allow us to monitor underwater acoustics generated by tectonic and ice-related events. We present spectrograms of the continuous hydroacoustic data and various types of signals, e.g. seismic T-waves, iceequakes, and tremors. There are periodic and harmonic tremors that might be related with tidal modulation, and the seasonal variation of the background noise seems to be related with sea ice concentration.

  20. Environmental influences on the spatial ecology of juvenile smalltooth sawfish (Pristis pectinata): results from acoustic monitoring.

    Science.gov (United States)

    Simpfendorfer, Colin A; Yeiser, Beau G; Wiley, Tonya R; Poulakis, Gregg R; Stevens, Philip W; Heupel, Michelle R

    2011-01-01

    To aid recovery efforts of smalltooth sawfish (Pristis pectinata) populations in U.S. waters a research project was developed to assess how changes in environmental conditions within estuarine areas affected the presence, movements, and activity space of this endangered species. Forty juvenile P. pectinata were fitted with acoustic tags and monitored within the lower 27 km of the Caloosahatchee River estuary, Florida, between 2005 and 2007. Sawfish were monitored within the study site from 1 to 473 days, and the number of consecutive days present ranged from 1 to 125. Residency index values for individuals varied considerably, with annual means highest in 2005 (0.95) and lowest in 2007 (0.73) when several P. pectinata moved upriver beyond detection range during drier conditions. Mean daily activity space was 1.42 km of river distance. The distance between 30-minute centers of activity was typically <0.1 km, suggesting limited movement over short time scales. Salinity electivity analysis demonstrated an affinity for salinities between 18 and at least 24 psu, suggesting movements are likely made in part, to remain within this range. Thus, freshwater flow from Lake Okeechobee (and its effect on salinity) affects the location of individuals within the estuary, although it remains unclear whether or not these movements are threatening recovery.

  1. Environmental influences on the spatial ecology of juvenile smalltooth sawfish (Pristis pectinata: results from acoustic monitoring.

    Directory of Open Access Journals (Sweden)

    Colin A Simpfendorfer

    Full Text Available To aid recovery efforts of smalltooth sawfish (Pristis pectinata populations in U.S. waters a research project was developed to assess how changes in environmental conditions within estuarine areas affected the presence, movements, and activity space of this endangered species. Forty juvenile P. pectinata were fitted with acoustic tags and monitored within the lower 27 km of the Caloosahatchee River estuary, Florida, between 2005 and 2007. Sawfish were monitored within the study site from 1 to 473 days, and the number of consecutive days present ranged from 1 to 125. Residency index values for individuals varied considerably, with annual means highest in 2005 (0.95 and lowest in 2007 (0.73 when several P. pectinata moved upriver beyond detection range during drier conditions. Mean daily activity space was 1.42 km of river distance. The distance between 30-minute centers of activity was typically <0.1 km, suggesting limited movement over short time scales. Salinity electivity analysis demonstrated an affinity for salinities between 18 and at least 24 psu, suggesting movements are likely made in part, to remain within this range. Thus, freshwater flow from Lake Okeechobee (and its effect on salinity affects the location of individuals within the estuary, although it remains unclear whether or not these movements are threatening recovery.

  2. Comprehensive bearing condition monitoring algorithm for incipient fault detection using acoustic emission

    Directory of Open Access Journals (Sweden)

    Amit R. Bhende

    2014-09-01

    Full Text Available The bearing reliability plays major role in obtaining the desired performance of any machine. A continuous condition monitoring of machine is required in certain applications where failure of machine leads to loss of production, human safety and precision. Machine faults are often linked to the bearing faults. Condition monitoring of machine involves continuous watch on the performance of bearings and predicting the faults of bearing before it cause any adversity. This paper investigates an experimental study to diagnose the fault while bearing is in operation. An acoustic emission technique is used in the experimentation. An algorithm is developed to process various types of signals generated from different bearing defects. The algorithm uses time domain analysis along with combination low frequency analysis technique such as fast Fourier transform and high frequency envelope detection. Two methods have adopted for envelope detection which are Hilbert transform and order analysis. Experimental study is carried out for deep groove ball bearing cage defect. Results show the potential effectiveness of the proposed algorithm to determine presence of fault, exact location and severity of fault.

  3. Conformational Changes of Calmodulin on Calcium and Peptide Binding Monitored by Film Bulk Acoustic Resonators

    Directory of Open Access Journals (Sweden)

    Janos Vörös

    2011-12-01

    Full Text Available Film bulk acoustic resonators (FBAR are mass sensitive, label-free biosensors that allow monitoring of the interaction between biomolecules. In this paper we use the FBAR to measure the binding of calcium and the CaMKII peptide to calmodulin. Because the mass of the calcium is too small to be detected, the conformational change caused by the binding process is measured by monitoring the resonant frequency and the motional resistance of the FBAR. The resonant frequency is a measure for the amount of mass coupled to the sensor while the motional resistance is influenced by the viscoelastic properties of the adsorbent. The measured frequency shift during the calcium adsorptions was found to be strongly dependent on the surface concentration of the immobilized calmodulin, which indicates that the measured signal is significantly influenced by the amount of water inside the calmodulin layer. By plotting the measured motional resistance against the frequency shift, a mass adsorption can be distinguished from processes involving measurable conformational changes. With this method three serial processes were identified during the peptide binding. The results show that the FBAR is a promising technology for the label-free measurement of conformational changes.

  4. Application of acoustical thermometry to noninvasive monitoring of internal temperature during laser hyperthermia

    Science.gov (United States)

    Krotov, Eugene V.; Yakovlev, Ivan V.; Zhadobov, Maxim; Reyman, Alexander M.; Zharov, Vladimir P.

    2002-06-01

    This work present the results of experimental study of applicability of acoustical brightness thermometry (ABT) in monitoring of internal temperature during laser hyperthermia and interstitial therapy. In these experiments the radiation of pulse repetition Nd:YAG laser (1064 nm) and continuous diode laser (800 nm) were used as heating sources. Experiments were performed in vitro by insertion of optical fiber inside the objects - optically transparent gelatin with incorporated light absorbing heterogeneities and samples of biological tissues (e.g. liver). During laser heating, internal temperature in absorbing heterogeneity and at fiber end were monitored by means of multi-channel ABT. The independent temperature control was performed with tiny electronic thermometer incorporated in heated zones. The results of experiments demonstrated reasonable sensitivity and accuracy of ABT for real-time temperature control during different kind of laser thermal therapies. According to preliminary data, ABT allow to measure temperature in depth up to 3-5 cm (depends on tissue properties) with spatial resolution some mm. Obtained data show that ABT is a very promising tool to give quantitative measure for different types of energy deposition (laser, microwave, focused ultrasound etc) at the depth commonly encountered in tumors of vital organs. Besides, ABT could give information about diffusion effects in heated zones or optical absorption. This work was supported by Russian Foundation for Basic Research and 6th competition-expertise of young scientists of Russian Academy of Sciences.

  5. Acoustic monitoring of sodium boiling in a liquid metal fast breeder reactor from autoregressive models

    Energy Technology Data Exchange (ETDEWEB)

    Geraldo, Issa Cherif [Laboratoire d’Automatique, Génie Informatique et Signal (LAGIS UMR CNRS 8219), Université Lille 1, Sciences et technologies, Avenue Paul Langevin, BP 48, 59651 Villeneuve d’Ascq CEDEX (France); Bose, Tanmoy [Indian Institute of Technology Kharagpur, Kharagpur 721302, West Bengal (India); Pekpe, Komi Midzodzi, E-mail: midzodzi.pekpe@univ-lille1.fr [Laboratoire d’Automatique, Génie Informatique et Signal (LAGIS UMR CNRS 8219), Université Lille 1, Sciences et technologies, Avenue Paul Langevin, BP 48, 59651 Villeneuve d’Ascq CEDEX (France); Cassar, Jean-Philippe [Laboratoire d’Automatique, Génie Informatique et Signal (LAGIS UMR CNRS 8219), Université Lille 1, Sciences et technologies, Avenue Paul Langevin, BP 48, 59651 Villeneuve d’Ascq CEDEX (France); Mohanty, A.R. [Indian Institute of Technology Kharagpur, Kharagpur 721302, West Bengal (India); Paumel, Kévin [CEA, DEN, Nuclear Technology Department, F-13108 Saint-Paul-lez-Durance (France)

    2014-10-15

    Highlights: • The work deals with sodium boiling detection in a liquid metal fast breeder reactor. • The authors choose to use acoustic data instead of thermal data. • The method is designed to not to be disturbed by the environment noises. • A real time boiling detection methods are proposed in the paper. - Abstract: This paper deals with acoustic monitoring of sodium boiling in a liquid metal fast breeder reactor (LMFBR) based on auto regressive (AR) models which have low computational complexities. Some authors have used AR models for sodium boiling or sodium–water reaction detection. These works are based on the characterization of the difference between fault free condition and current functioning of the system. However, even in absence of faults, it is possible to observe a change in the AR models due to the change of operating mode of the LMFBR. This sets up the delicate problem of how to distinguish a change in operating mode in absence of faults and a change due to presence of faults. In this paper we propose a new approach for boiling detection based on the estimation of AR models on sliding windows. Afterwards, classification of the models into boiling or non-boiling models is made by comparing their coefficients by two statistical methods, multiple linear regression (LR) and support vectors machines (SVM). The proposed approach takes into account operating mode information in order to avoid false alarms. Experimental data include non-boiling background noise data collected from Phenix power plant (France) and provided by the CEA (Commissariat à l’Energie Atomique et aux énergies alternatives, France) and boiling condition data generated in laboratory. High boiling detection rates as well as low false alarms rates obtained on these experimental data show that the proposed method is efficient for boiling detection. Most importantly, it shows that the boiling phenomenon introduces a disturbance into the AR models that can be clearly detected.

  6. Mechanical Weakening during Fluid Injection in Critically Stressed Sandstones with Acoustic Monitoring

    Science.gov (United States)

    David, C.; Dautriat, J. D.; Sarout, J.; Macault, R.; Bertauld, D.

    2014-12-01

    Water weakening is a well-known phenomenon which can lead to subsidence during the production of hydrocarbon reservoirs. The example of the Ekofisk oil field in the North Sea has been well documented for years. In order to assess water weakening effects in reservoir rocks, previous studies have focused on changes in the failure envelopes derived from mechanical tests conducted on rocks saturated either with water or with inert fluids. However, little attention has been paid so far on the mechanical behaviour during the fluid injection stage, like in enhanced oil recovery operations. We studied the effect of fluid injection on the mechanical behaviour of Sherwood sandstone, a weakly-consolidated sandstone sampled at Ladram Bay in UK. In order to highlight possible weakening effects, water and inert oil have been injected into critically-loaded samples to assess their effect on strength and elastic properties and to derive the acoustic signature of the saturation front for each fluid. The specimens were instrumented with 16 ultrasonic P-wave transducers for both passive and active acoustic monitoring during fluid injection and loading. After conducting standard triaxial tests on three samples saturated with air, water and oil respectively, mechanical creep tests were conducted on dry samples loaded at 80% of the compressive strength of the dry rock. While these conditions are kept constant, a fluid is injected at the bottom end of the sample with a low back pressure (0.5 MPa) to minimize effective stress variations during injection. Both water and oil were used as the injected pore fluid in two experiments. As soon as the fluids start to flow into the samples, creep is taking place with a much higher strain rate for water injection compared to oil injection. A transition from secondary creep to tertiary creep is observed in the water injection test whereas in the oil injection test no significant creep acceleration is observed after one pore volume of oil was

  7. Acoustic emission monitoring of unstable damage growth in CFRP composites under tension

    Science.gov (United States)

    Mills-Dadson, B.; Tran, D.; Asamene, K.; Whitlow, T.; Sundaresan, M.

    2017-02-01

    Composite structural members experience extensive and complex damage that accumulate in a relatively steady pace as the structure is quasi-statically loaded. This damage progression which starts as matrix cracks, delaminations, and random fiber breaks, turns unstable when groups of adjacent fibers, ranging from four to ten fibers fail together, after about 85% of ultimate strength, as reported in the literature. Identifying this critical damage that precedes the final fracture has been difficult even in laboratory specimens. There is little consensus on successful use of AE signals to differentiate failure modes. The inability of AE patterns to identify failure modes is likely caused by the limited frequency bandwidth of available AE sensors, and the high attenuation seen in AE signals particularly in the frequency range likely to be associated with fiber fractures. As a part of this study new acoustic emission sensors capable of measuring frequencies to 2 MHz were developed. In addition, composite specimens were instrumented with sufficient number of sensors to capture high frequency signals before they are attenuated. Unidirectional, cross-ply, and quasi-isotropic carbon-epoxy composite tensile specimens were monitored while they were statically loaded to failure. Distinctly different signals corresponding to the three failure modes could be observed. High frequency acoustic emission signals with frequencies well in excess of 1MHz, mostly seen in the last 20% of the loading cycle. Signals with frequencies in the range of 300 kHz to 700 kHz and duration of the order of 50 microseconds, were observed in cross ply and quasi-isotropic specimens, and are believed to be from matrix cracks. Fewer events with frequencies below 300 kHz and duration that exceeded about 200 microseconds are believed to be from delaminations. An important observation in this study is the appearance of groups of near identical waveforms, which are believed to be from clusters of adjacent

  8. A custom acoustic emission monitoring system for harsh environments: application to freezing-induced damage in alpine rock-walls

    Directory of Open Access Journals (Sweden)

    L. Girard

    2012-06-01

    Full Text Available We present a custom acoustic emission (AE monitoring system designed to perform long-term measurements on high-alpine rock-walls. AE monitoring is a common technique for characterizing damage evolution in solid materials. The system is based on a two-channel AE sensor node (AE-node integrated into a Wireless Sensor Network (WSN customized for operation in harsh environments. This wireless architecture offers flexibility in the deployment of AE-nodes at any position of the rock-wall that needs to be monitored, within a range of a few hundred meters from a core station connected to the internet. The system achieves near real-time data delivery and allows the user to remotely control the AE detection threshold. In order to protect AE sensors and capture acoustic signals from specific depths of the rock-wall, a special casing was developed. The monitoring system is completed by two probes that measure rock temperature and liquid water content, both probes being also integrated into the WSN. We report a first deployment of the monitoring system on a rock-wall at Jungfraujoch, 3500 m a.s.l., Switzerland. While this first deployment of the monitoring system aims to support fundamental research on processes that damage rock under cold climate, the system could serve a number of other applications, including rock-fall hazard surveillance or structural monitoring of concrete structures.

  9. A custom acoustic emission monitoring system for harsh environments: application to freezing-induced damage in alpine rock walls

    Directory of Open Access Journals (Sweden)

    L. Girard

    2012-11-01

    Full Text Available We present a custom acoustic emission (AE monitoring system designed to perform long-term measurements on high-alpine rock walls. AE monitoring is a common technique for characterizing damage evolution in solid materials. The system is based on a two-channel AE sensor node (AE-node integrated into a wireless sensor network (WSN customized for operation in harsh environments. This wireless architecture offers flexibility in the deployment of AE-nodes at any position of the rock wall that needs to be monitored, within a range of a few hundred meters from a core station connected to the internet. The system achieves near real-time data delivery and allows the user to remotely control the AE detection threshold. In order to protect AE sensors and capture acoustic signals from specific depths of the rock wall, a special casing was developed. The monitoring system is completed by two probes that measure rock temperature and liquid water content, both probes being also integrated into the WSN. We report a first deployment of the monitoring system on a rock wall at Jungfraujoch, 3500 m a.s.l., Switzerland. While this first deployment of the monitoring system aims to support fundamental research on processes that damage rock under cold climate, the system could serve a number of other applications, including rock fall hazard surveillance or structural monitoring of concrete structures.

  10. Glider-based Passive Acoustic Monitoring Techniques in the Southern California Region & West Coast Naval Training Range Demonstration of Glider-based Passive Acoustic Monitoring

    Science.gov (United States)

    2012-09-30

    distribution unlimited 13. SUPPLEMENTARY NOTES The original document contains color images. 14. ABSTRACT 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION...indicate sunset to sunrise , with vertical grid lines marking midnight local time. Figure 2 above shows data obtained from a HARP passive acoustic

  11. Non-invasive acoustic-based monitoring of uranium in solution and H/D ratio

    Energy Technology Data Exchange (ETDEWEB)

    Pantea, Cristian [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Beedle, Christopher Craig [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Sinha, Dipen N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lakis, Rollin Evan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-08-01

    The primary objective of this project is to adapt existing non-invasive acoustic techniques (Swept-Frequency Acoustic Interferometry and Gaussian-pulse acoustic technique) for the purpose of demonstrating the ability to quantify U or H/D ratios in solution. Furthermore, a successful demonstration will provide an easily implemented, low cost, and non-invasive method for remote and unattended uranium mass measurements for International Atomic Energy Agency (IAEA).

  12. Bedload transport monitoring with acoustic sensors in the Swiss Albula mountain river

    Science.gov (United States)

    Rickenmann, Dieter; Antoniazza, Gilles; Wyss, Carlos R.; Fritschi, Bruno; Boss, Stefan

    2017-03-01

    Bedload transport measurements with acoustic sensors were obtained during summer 2015 in the Albula River in Switzerland. An impact plate measuring system was used with geophone and accelerometer sensors. This system provides indirect estimations of bedload transport in water courses. In April 2015, 30 impact sensors were installed in a new permanent measuring station to monitor continuously bedload transport in a mountain river with a large annual rate of sediment transport (around 90 000 m3 yr-1). Records of the first year of measurement showed that (i) the signal response in terms of geophone and accelerometer impulses is comparable for both types of sensors; (ii) there is a good correlation between discharge data and impulses recorded by both types of sensors; (iii) the critical discharge at the start of bedload transport is around 5 m3 s-1; (iv) a mean calibration factor for the geophone impulses can be estimated which is in a similar range as values determined from other sites with field calibration measurements.

  13. Acoustic emission monitoring of multicell reinforced concrete box girders subjected to torsion.

    Science.gov (United States)

    Bagherifaez, Marya; Behnia, Arash; Majeed, Abeer Aqeel; Hwa Kian, Chai

    2014-01-01

    Reinforced concrete (RC) box girders are a common structural member for road bridges in modern construction. The hollow cross-section of a box girder is ideal in carrying eccentric loads or torques introduced by skew supports. This study employed acoustic emission (AE) monitoring on multicell RC box girder specimens subjected to laboratory-based torsion loading. Three multicell box girder specimens with different cross-sections were tested. The aim is to acquire AE analysis data indicative for characterizing torsion fracture in the box girders. It was demonstrated through appropriate parametric analysis that the AE technique could be utilized to effectively classify fracture developed in the specimens for describing their mechanical behavior under torsion. AE events localization was presented to illustrate the trend of crack and damage propagation in different stages of fracture. It could be observed that spiral-like patterns of crack were captured through AE damage localization system and damage was quantified successfully in different stages of fracture by using smoothed b-value analysis.

  14. Acoustic Emission Monitoring of Multicell Reinforced Concrete Box Girders Subjected to Torsion

    Directory of Open Access Journals (Sweden)

    Marya Bagherifaez

    2014-01-01

    Full Text Available Reinforced concrete (RC box girders are a common structural member for road bridges in modern construction. The hollow cross-section of a box girder is ideal in carrying eccentric loads or torques introduced by skew supports. This study employed acoustic emission (AE monitoring on multicell RC box girder specimens subjected to laboratory-based torsion loading. Three multicell box girder specimens with different cross-sections were tested. The aim is to acquire AE analysis data indicative for characterizing torsion fracture in the box girders. It was demonstrated through appropriate parametric analysis that the AE technique could be utilized to effectively classify fracture developed in the specimens for describing their mechanical behavior under torsion. AE events localization was presented to illustrate the trend of crack and damage propagation in different stages of fracture. It could be observed that spiral-like patterns of crack were captured through AE damage localization system and damage was quantified successfully in different stages of fracture by using smoothed b-value analysis.

  15. The Contact State Monitoring for Seal End Faces Based on Acoustic Emission Detection

    Directory of Open Access Journals (Sweden)

    Xiaohui Li

    2016-01-01

    Full Text Available Monitoring the contact state of seal end faces would help the early warning of the seal failure. In the acoustic emission (AE detection for mechanical seal, the main difficulty is to reduce the background noise and to classify the dispersed features. To solve these problems and achieve higher detection rates, a new approach based on genetic particle filter with autoregression (AR-GPF and hypersphere support vector machine (HSSVM is presented. First, AR model is used to build the dynamic state space (DSS of the AE signal, and GPF is used for signal filtering. Then, multiple features are extracted, and a classification model based on HSSVM is constructed for state recognition. In this approach, AR-GPF is an excellent time-domain method for noise reduction, and HSSVM has advantage on those dispersed features. Finally experimental data shows that the proposed method can effectively detect the contact state of the seal end faces and has higher accuracy rates than some other existing methods.

  16. Influence of geometry on the fracturing behavior of textile reinforced cement monitored by acoustic emission

    Science.gov (United States)

    Aggelis, D. G.; Blom, J.; El Kadi, M.; Wastiels, J.

    2014-03-01

    In this work the flexural behavior of textile reinforced cement (TRC) laminate is examined using acoustic emission (AE). The TRC composite is a combination of inorganic phosphate cement (IPC) with randomly distributed glass fibres. IPC has been developed at the "Vrije Universiteit Brussel" and shows a neutral pH meaning that glass fibers are hardly attacked. During bending, stresses lead to the activation of damage mechanisms like matrix cracking, delaminations and fiber pull-out being in succession or overlapping in time. AE records the responses of the damage propagation events and allows the monitoring of the fracture behavior from the onset to the final stage. The effect of the span in three-point bending tests, which is varied to create different stress fields, is targeted. Parameters like duration and frequency reveal information about the mode of the damage sources in relation to the span. Results show that as the span decreases, the dominant damage mode shifts away from bending and acquires more shear characteristics by increasing the interlaminar shearing events.

  17. Real-time monitoring of human blood clotting using a lateral excited film bulk acoustic resonator

    Science.gov (United States)

    Chen, Da; Wang, Jingjng; Wang, Peng; Guo, Qiuquan; Zhang, Zhen; Ma, Jilong

    2017-04-01

    Frequent assay of hemostatic status is an essential issue for the millions of patients using anticoagulant drugs. In this paper, we presented a micro-fabricated film bulk acoustic sensor for the real-time monitoring of blood clotting and the measurement of hemostatic parameters. The device was made of an Au/ZnO/Si3N4 film stack and excited by a lateral electric field. It operated under a shear mode resonance with the frequency of 1.42 GHz and had a quality factor of 342 in human blood. During the clotting process of blood, the resonant frequency decreased along with the change of blood viscosity and showed an apparent step-ladder curve, revealing the sequential clotting stages. An important hemostatic parameter, prothrombin time, was quantitatively determined from the frequency response for different dilutions of the blood samples. The effect of a typical anticoagulant drug (heparin) on the prothrombin time was exemplarily shown. The proposed sensor displayed a good consistency and clinical comparability with the standard coagulometric methods. Thanks to the availability of direct digital signals, excellent potentials of miniaturization and integration, the proposed sensor has promising application for point-of-care coagulation technologies.

  18. Monitoring the quality consistency of Fufang Danshen Pills using micellar electrokinetic chromatography fingerprint coupled with prediction of antioxidant activity and chemometrics.

    Science.gov (United States)

    Ji, Zhengchao; Sun, Wanyang; Sun, Guoxiang; Zhang, Jin

    2016-08-01

    A fast micellar electrokinetic chromatography fingerprint method combined with quantification was developed and validated to evaluate the quality of Fufang Danshen Pills, a traditional Chinese Medicine, which has been used in the treatment of cardiovascular system diseases, in which the tetrahedron optimization method was first used to optimize the background electrolyte solution. Subsequently, the index of the fingerprint information amount of I was performed as an excellent objective indictor to investigate the experimental conditions. In addition, a systematical quantified fingerprint method was constructed for evaluating the quality consistency of 20 batches of test samples obtained from the same drug manufacturer. The fingerprint analysis combined with quantitative determination of two components showed that the quality consistency of the test samples was quite good within the same commercial brand. Furthermore, the partial least squares model analysis was used to explore the fingerprint-efficacy relationship between active components and antioxidant activity in vitro, which can be applied for the assessment of anti-oxidant activity of Fufang Danshen pills and provide valuable medicinal information for quality control. The result illustrated that the present study provided a reliable and reasonable method for monitoring the quality consistency of Fufang Danshen pills.

  19. Wear monitoring of single point cutting tool using acoustic emission techniques

    Indian Academy of Sciences (India)

    P Kulandaivelu; P Senthil Kumar; S Sundaram

    2013-04-01

    This paper examines the flank and crater wear characteristics of coated carbide tool inserts during dry turning of steel workpieces. A brief review of tool wear mechanisms is presented together with new evidence showing that wear of the TiC layer on both flank and rake faces is dominated by discrete plastic deformation, which causes the coating to be worn through to the underlying carbide substrate when machining at high cutting speeds and feed rates. Wear also occurs as a result of abrasion, as well as cracking and attrition, with the latter leading to the wearing through the coating on the rake face under low speed conditions. When moderate speeds and feeds are used, the coating remains intact throughout the duration of testing. Wear mechanism maps linking the observed wear mechanisms to machining conditions are presented for the first time. These maps demonstrate clearly that transitions from one dominant wear mechanism to another may be related to variations in measured tool wear rates. Comparisons of the present wear maps with similar maps for uncoated carbide tools show that TiC coatings dramatically expand the range of machining conditions under which acceptable rates of tool wear might be experienced. However, the extent of improvement brought about by the coatings depends strongly on the cutting conditions, with the greatest benefits being seen at higher cutting speeds and feed rates. Among these methods, tool condition monitoring using Acoustic Techniques (AET) is an emerging one. Hence, the present work was carried out to study the stability, applicability and relative sensitivity of AET in tool condition monitoring in turning.

  20. Fatigue crack growth monitoring of idealized gearbox spline component using acoustic emission

    Science.gov (United States)

    Zhang, Lu; Ozevin, Didem; Hardman, William; Kessler, Seth; Timmons, Alan

    2016-04-01

    The spline component of gearbox structure is a non-redundant element that requires early detection of flaws for preventing catastrophic failures. The acoustic emission (AE) method is a direct way of detecting active flaws; however, the method suffers from the influence of background noise and location/sensor based pattern recognition method. It is important to identify the source mechanism and adapt it to different test conditions and sensors. In this paper, the fatigue crack growth of a notched and flattened gearbox spline component is monitored using the AE method in a laboratory environment. The test sample has the major details of the spline component on a flattened geometry. The AE data is continuously collected together with strain gauges strategically positions on the structure. The fatigue test characteristics are 4 Hz frequency and 0.1 as the ratio of minimum to maximum loading in tensile regime. It is observed that there are significant amount of continuous emissions released from the notch tip due to the formation of plastic deformation and slow crack growth. The frequency spectra of continuous emissions and burst emissions are compared to understand the difference of sudden crack growth and gradual crack growth. The predicted crack growth rate is compared with the AE data using the cumulative AE events at the notch tip. The source mechanism of sudden crack growth is obtained solving the inverse mathematical problem from output signal to input signal. The spline component of gearbox structure is a non-redundant element that requires early detection of flaws for preventing catastrophic failures. In this paper, the fatigue crack growth of a notched and flattened gearbox spline component is monitored using the AE method The AE data is continuously collected together with strain gauges. There are significant amount of continuous emissions released from the notch tip due to the formation of plastic deformation and slow crack growth. The source mechanism of

  1. Detection of bond failure in the anchorage zone of reinforced concrete beams via acoustic emission monitoring

    Science.gov (United States)

    Abouhussien, Ahmed A.; Hassan, Assem A. A.

    2016-07-01

    In this study, acoustic emission (AE) monitoring was utilised to identify the onset of bond failure in reinforced concrete beams. Beam anchorage specimens were designed and tested to fail in bond in the anchorage zone. The specimens included four 250 × 250 × 1500 mm beams with four variable bonded lengths (100, 200, 300, and 400 mm). Meanwhile, an additional 250 × 250 × 2440 mm beam, with 200 mm bonded length, was tested to investigate the influence of sensor location on the identification of bond damage. All beams were tested under four-point loading setup and continuously monitored using three distributed AE sensors. These attached sensors were exploited to record AE signals resulting from both cracking and bond deterioration until failure. The variations in the number of AE hits and cumulative signal strength (CSS) versus test time were evaluated to achieve early detection of crack growth and bar slippage. In addition, AE intensity analysis was performed on signal strength of collected AE signals to develop two additional parameters: historic index (H (t)) and severity (S r). The analysis of these AE parameters enabled an early detection of both first cracks (at almost the mid-span of the beam) and bar slip in either of the anchorage zones at the beams’ end before their visual observation, regardless of sensor location. The results also demonstrated a clear correlation between the damage level in terms of crack development/measured free end bar slip and AE parameters (number of hits, CSS, H(t), and S r).

  2. Stability monitoring system using acoustic emissions. Sistema de control de la estabilidad basado en la emision acustica

    Energy Technology Data Exchange (ETDEWEB)

    Celada Tamames, B.; Varona Eraso, P.; Velasco Trivino, E. (Geocontrol, S.A., Madrid (Spain))

    1989-11-01

    In 1987, the ECSC decided to offer part funding to a research project being carried out by Geocontrol SA concerning the development of a system for monitoring stability by the use of acoustic emissions. The project focuses on predicting instability in coal pillars. The present article describes the first lines of investigation during 1988 and 1989 and the results so far. 10 refs., 5 figs.

  3. Combined passive acoustic mapping and magnetic resonance thermometry for monitoring phase-shift nanoemulsion enhanced focused ultrasound therapy

    Science.gov (United States)

    Crake, Calum; Meral, F. Can; Burgess, Mark T.; Papademetriou, Iason T.; McDannold, Nathan J.; Porter, Tyrone M.

    2017-08-01

    Focused ultrasound (FUS) has the potential to enable precise, image-guided noninvasive surgery for the treatment of cancer in which tumors are identified and destroyed in a single integrated procedure. However, success of the method in highly vascular organs has been limited due to heat losses to perfusion, requiring development of techniques to locally enhance energy absorption and heating. In addition, FUS procedures are conventionally monitored using MRI, which provides excellent anatomical images and can map temperature, but is not capable of capturing the full gamut of available data such as the acoustic emissions generated during this inherently acoustically-driven procedure. Here, we employed phase-shift nanoemulsions (PSNE) embedded in tissue phantoms to promote cavitation and hence temperature rise induced by FUS. In addition, we incorporated passive acoustic mapping (PAM) alongside simultaneous MR thermometry in order to visualize both acoustic emissions and temperature rise, within the bore of a full scale clinical MRI scanner. Focal cavitation of PSNE could be resolved using PAM and resulted in accelerated heating and increased the maximum elevated temperature measured via MR thermometry compared to experiments without nanoemulsions. Over time, the simultaneously acquired acoustic and temperature maps show translation of the focus of activity towards the FUS transducer, and the magnitude of the increase in cavitation and focal shift both increased with nanoemulsion concentration. PAM results were well correlated with MRI thermometry and demonstrated greater sensitivity, with the ability to detect cavitation before enhanced heating was observed. The results suggest that PSNE could be beneficial for enhancement of thermal focused ultrasound therapies and that PAM could be a critical tool for monitoring this process.

  4. Acoustic eyes: a novel sound source localization and monitoring technique with 3D sound probes

    NARCIS (Netherlands)

    Basten, T.G.H.; Bree, H.E. de; Sadasivan, S.

    2008-01-01

    In this paper the most recent advances are discussed on a new acoustic far field sound source localization technique using (at least) two three dimensional sound probes. The compact and broadband probes are based upon three orthogonally placed acoustic particle velocity sensors (Microflowns) and a s

  5. Systems and methods of monitoring acoustic pressure to detect a flame condition in a gas turbine

    Energy Technology Data Exchange (ETDEWEB)

    Ziminsky, Willy Steve (Simpsonville, SC); Krull, Anthony Wayne (Anderson, SC); Healy, Timothy Andrew (Simpsonville, SC), Yilmaz, Ertan (Glenville, NY)

    2011-05-17

    A method may detect a flashback condition in a fuel nozzle of a combustor. The method may include obtaining a current acoustic pressure signal from the combustor, analyzing the current acoustic pressure signal to determine current operating frequency information for the combustor, and indicating that the flashback condition exists based at least in part on the current operating frequency information.

  6. On-line structural integrity monitoring and defect diagnosis of steam generators using analysis of guided acoustic waves

    Science.gov (United States)

    Lu, Baofu

    2005-11-01

    Integrity monitoring and flaw diagnostics of flat beams and tubular structures was investigated in this research using guided acoustic signals. The primary objective was to study the feasibility of using imbedded sensors for monitoring steam generator and heat exchanger tubing. A piezo-sensor suite was deployed to activate and collect Lamb wave signals that propagate along metallic specimens. The dispersion curves of Lamb waves along plate and tubular structures were generated through numerical analysis. Several advanced techniques were explored to extract representative features from acoustic time series. Among them, the Hilbert-Huang transform (HHT) is a recently developed technique for the analysis of non-linear and transient signals. A moving window method was introduced to generate the local peak characters from acoustic time series, and a zooming window technique was developed to localize the structural flaws. The dissertation presents the background of the analysis of acoustic signals acquired from piezo-electric transducers for structural defect monitoring. A comparison of the use of time-frequency techniques, including the Hilbert-Huang transform, is presented. It also presents the theoretical study of Lamb wave propagation in flat beams and tubular structures, and the need for mode separation in order to effectively perform defect diagnosis. The results of an extensive experimental study of detection, location, and isolation of structural defects in flat aluminum beams and brass tubes are presented. The time-frequency analysis and pattern recognition techniques were combined for classifying structural defects in brass tubes. Several types of flaws in brass tubes were tested, both in the air and in water. The techniques also proved to be effective under background/process noise. A detailed theoretical analysis of Lamb wave propagation was performed and simulations were carried out using the finite element software system ABAQUS. This analytical study

  7. Real Time System for Practical Acoustic Monitoring of Global Ocean Temperature

    Science.gov (United States)

    1994-11-04

    designing the hardware and software required to collect the acoustic signals at the SOSUS stations. Marguerrite McElroy, Paul Bushong , Wendy Lawrence...equations," Survey Review, 176, Vol. XXIII, p. 88-94, (1975). 26 𔃼J.L. Spiesberger, P.J. Bushong , K. Metzger, and T.G. Birdsall, "Ocean acoustic to...mography: estimating the acoustic travel time with phase," IEEE J. Ocean. Eng. 14, 108-119 (1989). ൕJ.L. Spiesberger, P.J. Bushong , K. Metzger, and

  8. Graphic presentation of information of acoustic monitoring of stream grinding process

    Directory of Open Access Journals (Sweden)

    N.S. Pryadko

    2012-04-01

    Full Text Available The theoretical and experimental mechanisms of thin grinding the loose materials are analyzed. The relation of the density function of acoustic signal amplitudes of grinding process to the degree of loading the jets by material is established.

  9. In vivo monitoring of implant osseointegration in a rabbit model using acoustic sound analysis

    National Research Council Canada - National Science Library

    Ruther, Cathérine; Gabler, Carolin; Ewald, Hartmut; Ellenrieder, Martin; Haenle, Maximilian; Lindner, Tobias; Mittelmeier, Wolfram; Bader, Rainer; Kluess, Daniel

    2014-01-01

    Implant osseointegration can currently only be assessed reliably post mortem. A novel method that relies on the principle of acoustic sound analysis was developed to enable examination of the longitudinal progress of osseointegration...

  10. The Development of Advanced Passive Acoustic Monitoring Systems Using microMARS Technology

    Science.gov (United States)

    2015-09-30

    the recorder firmware to provide a more stable sample rate. 7. Changes to the recorder firmware to keep recording segment start times on a rigid and...acoustic recorders on the market today are suitable for marine mammal detection and classification purposes only, but do not offer a localization capability...the basis for Advanced microMARS. http://desertstar.com/product/micromars/ • The TLP series acoustic pingers, developed as part of the RangeNav

  11. Acoustic Monitoring of Beluga Whale Interactions with Cook Inlet Tidal Energy Project

    Energy Technology Data Exchange (ETDEWEB)

    Worthington, Monty [Project Director - AK

    2014-02-05

    Cook Inlet, Alaska is home to some of the greatest tidal energy resources in the U.S., as well as an endangered population of beluga whales (Delphinapterus leucas). Successfully permitting and operating a tidal power project in Cook Inlet requires a biological assessment of the potential and realized effects of the physical presence and sound footprint of tidal turbines on the distribution, relative abundance, and behavior of Cook Inlet beluga whales. ORPC Alaska, working with the Project Team—LGL Alaska Research Associates, University of Alaska Anchorage, TerraSond, and Greeneridge Science—undertook the following U.S. Department of Energy (DOE) study to characterize beluga whales in Cook Inlet – Acoustic Monitoring of Beluga Whale Interactions with the Cook Inlet Tidal Energy Project (Project). ORPC Alaska, LLC, is a wholly-owned subsidiary of Ocean Renewable Power Company, LLC, (collectively, ORPC). ORPC is a global leader in the development of hydrokinetic power systems and eco-conscious projects that harness the power of ocean and river currents to create clean, predictable renewable energy. ORPC is developing a tidal energy demonstration project in Cook Inlet at East Foreland where ORPC has a Federal Energy Regulatory Commission (FERC) preliminary permit (P-13821). The Project collected baseline data to characterize pre-deployment patterns of marine mammal distribution, relative abundance, and behavior in ORPC’s proposed deployment area at East Foreland. ORPC also completed work near Fire Island where ORPC held a FERC preliminary permit (P-12679) until March 6, 2013. Passive hydroacoustic devices (previously utilized with bowhead whales in the Beaufort Sea) were adapted for study of beluga whales to determine the relative abundance of beluga whale vocalizations within the proposed deployment areas. Hydroacoustic data collected during the Project were used to characterize the ambient acoustic environment of the project site pre-deployment to inform the

  12. ChemFlow, chemometrics using Galaxy

    OpenAIRE

    Rossard, Virginie; Boulet, Jean Claude; Gogé, Fabien; Latrille, Eric; Roger, Jean-Michel

    2016-01-01

    Infrared spectroscopy is widely used in academic research and industry as simple, fast, cheap and safe measurement tool. The infrared data are displayed as spectra, and chemometric is a science which aims at extracting informations from spectra. We are developing a comprehensive package which contains (1) a MOOC broadcasted in september 2016; (2) a chemometric tool, named ChemFlow, which is an application of Galaxy; and (3) a spectral database. We will focus on ChemFlow. The required specifi...

  13. An Ethnographic Observational Study to Evaluate and Optimize the Use of Respiratory Acoustic Monitoring in Children Receiving Postoperative Opioid Infusions.

    Science.gov (United States)

    Görges, Matthias; West, Nicholas C; Christopher, Nancy A; Koch, Jennifer L; Brodie, Sonia M; Lowlaavar, Nasim; Lauder, Gillian R; Ansermino, J Mark

    2016-04-01

    Respiratory depression in children receiving postoperative opioid infusions is a significant risk because of the interindividual variability in analgesic requirement. Detection of respiratory depression (or apnea) in these children may be improved with the introduction of automated acoustic respiratory rate (RR) monitoring. However, early detection of adverse events must be balanced with the risk of alarm fatigue. Our objective was to evaluate the use of acoustic RR monitoring in children receiving opioid infusions on a postsurgical ward and identify the causes of false alarm and optimal alarm thresholds. A video ethnographic study was performed using an observational, mixed methods approach. After surgery, an acoustic RR sensor was placed on the participant's neck and attached to a Rad87 monitor. The monitor was networked with paging for alarms. Vital signs data and paging notification logs were obtained from the central monitoring system. Webcam videos of the participant, infusion pump, and Rad87 monitor were recorded, stored on a secure server, and subsequently analyzed by 2 research nurses to identify the cause of the alarm, response, and effectiveness. Alarms occurring within a 90-second window were grouped into a single-alarm response opportunity. Data from 49 patients (30 females) with median age 14 (range, 4.4-18.8) years were analyzed. The 896 bedside vital sign threshold alarms resulted in 160 alarm response opportunities (44 low RR, 74 high RR, and 42 low SpO2). In 141 periods (88% of total), for which video was available, 65% of alarms were deemed effective (followed by an alarm-related action within 10 minutes). Nurses were the sole responders in 55% of effective alarms and the patient or parent in 20%. Episodes of desaturation (SpO2 10 bpm in 6 of 9 patients. Based on all RR samples observed, the default alarm thresholds, to serve as a starting point for each patient, would be a low RR of 6 (>10 years of age) and 10 (4-9 years of age). In this study

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

    Science.gov (United States)

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

    1997-06-01

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

  15. A Permanent Automated Real-Time Passive Acoustic Monitoring System for Bottlenose Dolphin Conservation in the Mediterranean Sea.

    Directory of Open Access Journals (Sweden)

    Marco Brunoldi

    Full Text Available Within the framework of the EU Life+ project named LIFE09 NAT/IT/000190 ARION, a permanent automated real-time passive acoustic monitoring system for the improvement of the conservation status of the transient and resident population of bottlenose dolphin (Tursiops truncatus has been implemented and installed in the Portofino Marine Protected Area (MPA, Ligurian Sea. The system is able to detect the simultaneous presence of dolphins and boats in the area and to give their position in real time. This information is used to prevent collisions by diffusing warning messages to all the categories involved (tourists, professional fishermen and so on. The system consists of two gps-synchronized acoustic units, based on a particular type of marine buoy (elastic beacon, deployed about 1 km off the Portofino headland. Each one is equipped with a four-hydrophone array and an onboard acquisition system which can record the typical social communication whistles emitted by the dolphins and the sound emitted by boat engines. Signals are pre-filtered, digitized and then broadcast to the ground station via wi-fi. The raw data are elaborated to get the direction of the acoustic target to each unit, and hence the position of dolphins and boats in real time by triangulation.

  16. IDENTIFICATION AND MONITORING OF NOISE SOURCES OF CNC MACHINE TOOLS BY ACOUSTIC HOLOGRAPHY METHODS

    Directory of Open Access Journals (Sweden)

    Jerzy Józwik

    2016-06-01

    Full Text Available The paper presents the analysis of sound field emitted by selected CNC machine tools. The identification of noise sources and level was measured by acoustic holography for the 3-axis DMC 635eco machine tool and the 5-axis vertical machining centre DMU 65 monoBlock. The acoustic holography method allows precise identification and measurement of noise sources at different bandwidths of frequency. Detection of noise sources in tested objects allows diagnosis of their technical condition, as well as choice of effective means of noise reduction, which is highly significant from the perspective of minimising noise at the CNC machine operator workstation. Test results were presented as acoustic maps in various frequency ranges. Noise sources of the machine tool itself were identified, as well as the range of noise influence and the most frequent places of reflections and their span. The results of measurements were presented in figures and diagrams.

  17. Acoustic emission monitoring of activation behavior of LaNi5 hydrogen storage alloy

    Directory of Open Access Journals (Sweden)

    Igor Maria De Rosa, Alessandro Dell'Era, Mauro Pasquali, Carlo Santulli and Fabrizio Sarasini

    2011-01-01

    Full Text Available The acoustic emission technique is proposed for assessing the irreversible phenomena occurring during hydrogen absorption/desorption cycling in LaNi5. In particular, we have studied, through a parametric analysis of in situ detected signals, the correlation between acoustic emission (AE parameters and the processes occurring during the activation of an intermetallic compound. Decreases in the number and amplitude of AE signals suggest that pulverization due to hydrogen loading involves progressively smaller volumes of material as the number of cycles increases. This conclusion is confirmed by electron microscopy observations and particle size distribution measurements.

  18. Chemometrics in Fingerprinting by Means of Thin Layer Chromatography

    Directory of Open Access Journals (Sweden)

    Łukasz Komsta

    2012-01-01

    Full Text Available The paper is written as an introductory review, presenting summary of current knowledge about chemometric fingerprinting in the context of TLC, due to a rather small interest in the literature about joining TLC and chemometrics. The paper shortly covers the most important aspects of the chemometric fingerprinting in general, creating the TLC fingerprints, denoising, baseline removal, warping/registering, and chemometric processing itself. References being good candidates as a starting point are given for each topic and processing step.

  19. Marine Mammal Acoustic Monitoring and Habitat Investigation, Southern California Offshore Region

    Science.gov (United States)

    2007-11-01

    performed with customized routines in Matlab (Mathworks, Natick, MA). An automatic click detection algorithm is run on all acoustic data to locate the...dolphin: A review. Marine Mammal Science 2: 34–63. SIROVIC, A., J. A. HILDEBRAND, S. M. WIGGINS, M. A. MCDONALD, S. E. MOORE and D. THIELE . 2004

  20. Artificial Neural Network Model for Monitoring Oil Film Regime in Spur Gear Based on Acoustic Emission Data

    Directory of Open Access Journals (Sweden)

    Yasir Hassan Ali

    2015-01-01

    Full Text Available The thickness of an oil film lubricant can contribute to less gear tooth wear and surface failure. The purpose of this research is to use artificial neural network (ANN computational modelling to correlate spur gear data from acoustic emissions, lubricant temperature, and specific film thickness (λ. The approach is using an algorithm to monitor the oil film thickness and to detect which lubrication regime the gearbox is running either hydrodynamic, elastohydrodynamic, or boundary. This monitoring can aid identification of fault development. Feed-forward and recurrent Elman neural network algorithms were used to develop ANN models, which are subjected to training, testing, and validation process. The Levenberg-Marquardt back-propagation algorithm was applied to reduce errors. Log-sigmoid and Purelin were identified as suitable transfer functions for hidden and output nodes. The methods used in this paper shows accurate predictions from ANN and the feed-forward network performance is superior to the Elman neural network.

  1. Passive acoustic monitoring to detect spawning in large-bodied catostomids

    Science.gov (United States)

    Straight, Carrie A.; Freeman, Byron J.; Freeman, Mary C.

    2014-01-01

    Documenting timing, locations, and intensity of spawning can provide valuable information for conservation and management of imperiled fishes. However, deep, turbid or turbulent water, or occurrence of spawning at night, can severely limit direct observations. We have developed and tested the use of passive acoustics to detect distinctive acoustic signatures associated with spawning events of two large-bodied catostomid species (River Redhorse Moxostoma carinatum and Robust Redhorse Moxostoma robustum) in river systems in north Georgia. We deployed a hydrophone with a recording unit at four different locations on four different dates when we could both record and observe spawning activity. Recordings captured 494 spawning events that we acoustically characterized using dominant frequency, 95% frequency, relative power, and duration. We similarly characterized 46 randomly selected ambient river noises. Dominant frequency did not differ between redhorse species and ranged from 172.3 to 14,987.1 Hz. Duration of spawning events ranged from 0.65 to 11.07 s, River Redhorse having longer durations than Robust Redhorse. Observed spawning events had significantly higher dominant and 95% frequencies than ambient river noises. We additionally tested software designed to automate acoustic detection. The automated detection configurations correctly identified 80–82% of known spawning events, and falsely indentified spawns 6–7% of the time when none occurred. These rates were combined over all recordings; rates were more variable among individual recordings. Longer spawning events were more likely to be detected. Combined with sufficient visual observations to ascertain species identities and to estimate detection error rates, passive acoustic recording provides a useful tool to study spawning frequency of large-bodied fishes that displace gravel during egg deposition, including several species of imperiled catostomids.

  2. Continuous wavelet transform analysis and modal location analysis acoustic emission source location for nuclear piping crack growth monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Mohd, Shukri [Nondestructive Testing Group, Industrial Technology Division, Malaysian Nuclear Agency, 43000, Bangi, Selangor (Malaysia); Holford, Karen M.; Pullin, Rhys [Cardiff School of Engineering, Cardiff University, Queen' s Buildings, The Parade, CARDIFF CF24 3AA (United Kingdom)

    2014-02-12

    Source location is an important feature of acoustic emission (AE) damage monitoring in nuclear piping. The ability to accurately locate sources can assist in source characterisation and early warning of failure. This paper describe the development of a novelAE source location technique termed 'Wavelet Transform analysis and Modal Location (WTML)' based on Lamb wave theory and time-frequency analysis that can be used for global monitoring of plate like steel structures. Source location was performed on a steel pipe of 1500 mm long and 220 mm outer diameter with nominal thickness of 5 mm under a planar location test setup using H-N sources. The accuracy of the new technique was compared with other AE source location methods such as the time of arrival (TOA) techniqueand DeltaTlocation. Theresults of the study show that the WTML method produces more accurate location resultscompared with TOA and triple point filtering location methods. The accuracy of the WTML approach is comparable with the deltaT location method but requires no initial acoustic calibration of the structure.

  3. Real-time structural integrity monitoring using a passive quadrature demodulated, localised Michelson optical fibre interferometer capable of simultaneous strain and acoustic emission sensing

    Science.gov (United States)

    Tapanes, Edward

    1991-12-01

    A Michelson Fiber optic sensor (MFOS) is described for in-situ strain and vibration monitoring as well as acoustic emission detection in composite material structures. The phase sensitive fiber optic sensor is localized, all-fiber, and intrinsic. The MFOS was successfully embedded in Kevlar/epoxy and graphite/epoxy thermosets as well as graphite/PEEK thermoplastic in order to perform local strain and vibration measurements at the lamina level. A technique allowing acoustic emission detection in parallel with strain and vibration monitoring is illustrated.

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

    Directory of Open Access Journals (Sweden)

    Casals-Torrens P.

    2012-04-01

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

  5. Monitoring near-shore shingle transport under waves using a passive acoustic technique.

    Science.gov (United States)

    Mason, T; Priestley, D; Reeve, D E

    2007-08-01

    Passive acoustic techniques have been used to measure shingle (gravel) sediment transport in very shallow water, near the wave breaking zone on a beach. The experiments were conducted at 1:1 scale in the Large Wave Flume, Grosse Wellen Kanal (GWK) at Hannover, Germany. The frequency spectrum induced by shingle mobilized under breaking waves can be distinguished from other ambient noise, and is found to be independent of water depth and wave conditions. The inverse relationship between centroid frequency and representative grain size is shown to remain valid in shallow water wave conditions. Individual phases of onshore and offshore transport can be identified. Analysis of the acoustic frequency spectrum provides insight into the mechanics of phase-resolved shingle transport.

  6. Seasonal migrations of North Atlantic minke whales: novel insights from large-scale passive acoustic monitoring networks.

    Science.gov (United States)

    Risch, Denise; Castellote, Manuel; Clark, Christopher W; Davis, Genevieve E; Dugan, Peter J; Hodge, Lynne Ew; Kumar, Anurag; Lucke, Klaus; Mellinger, David K; Nieukirk, Sharon L; Popescu, Cristian Marian; Ramp, Christian; Read, Andrew J; Rice, Aaron N; Silva, Monica A; Siebert, Ursula; Stafford, Kathleen M; Verdaat, Hans; Van Parijs, Sofie M

    2014-01-01

    Little is known about migration patterns and seasonal distribution away from coastal summer feeding habitats of many pelagic baleen whales. Recently, large-scale passive acoustic monitoring networks have become available to explore migration patterns and identify critical habitats of these species. North Atlantic minke whales (Balaenoptera acutorostrata) perform seasonal migrations between high latitude summer feeding and low latitude winter breeding grounds. While the distribution and abundance of the species has been studied across their summer range, data on migration and winter habitat are virtually missing. Acoustic recordings, from 16 different sites from across the North Atlantic, were analyzed to examine the seasonal and geographic variation in minke whale pulse train occurrence, infer information about migration routes and timing, and to identify possible winter habitats. Acoustic detections show that minke whales leave their winter grounds south of 30° N from March through early April. On their southward migration in autumn, minke whales leave waters north of 40° N from mid-October through early November. In the western North Atlantic spring migrants appear to track the warmer waters of the Gulf Stream along the continental shelf, while whales travel farther offshore in autumn. Abundant detections were found off the southeastern US and the Caribbean during winter. Minke whale pulse trains showed evidence of geographic variation, with longer pulse trains recorded south of 40° N. Very few pulse trains were recorded during summer in any of the datasets. This study highlights the feasibility of using acoustic monitoring networks to explore migration patterns of pelagic marine mammals. Results confirm the presence of minke whales off the southeastern US and the Caribbean during winter months. The absence of pulse train detections during summer suggests either that minke whales switch their vocal behaviour at this time of year, are absent from available

  7. Fatigue Damage Monitoring in 304L Steel Specimens by an Acoustic Emission Method

    Directory of Open Access Journals (Sweden)

    Ould-Amer Ammar

    2014-06-01

    Full Text Available The aim of this work was to clarify fatigue crack initiation and propagation mechanisms in 304L austenitic stainless steel under different total-strain-amplitudes. A complete process from crack initiation and propagation was recorded by using the acoustic emission method in one hand, and replica method in another hand. The effect of strain amplitude on fatigue crack growth was investigated and a new representation of various fatigue curves associated to various levels of fatigue damage is proposed.

  8. Feasibility study of using smart aggregates as embedded acoustic emission sensors for health monitoring of concrete structures

    Science.gov (United States)

    Li, Weijie; Kong, Qingzhao; Ho, Siu Chun Michael; Lim, Ing; Mo, Y. L.; Song, Gangbing

    2016-11-01

    Acoustic emission (AE) is a nondestructive evaluation technique that is capable of monitoring the damage evolution of concrete structures in real time. Conventionally, AE sensors are surface mounted on the host structures, however, the AE signals attenuate quickly due to the high attenuation properties of concrete structures. This study conducts a feasibility study of using smart aggregates (SAs), which are a type of embedded piezoceramic transducers, as embedded AE sensors for the health monitoring of concrete structures. A plain concrete beam with two surface mounted AE sensors and two embedded SAs was fabricated in laboratory and loaded under a designed three-point-bending test. The performance of embedded SAs were compared with the traditional surface mounted AE sensors in their ability to detect and evaluate the damage to the concrete structure. The results verified the feasibility of using smart aggregates as embedded AE sensors for monitoring structural damage in concrete. Potentially, the low cost smart aggregates could function as embedded AE sensors, providing great sensitivity and high reliability in applications for the structural health monitoring of concrete structures.

  9. Detection of explosive events by monitoring acoustically-induced geomagnetic perturbations

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, J P; Rock, D R; Shaeffer, D L; Warshaw, S I

    1999-10-07

    The Black Thunder Coal Mine (BTCM) near Gillette, Wyoming was used as a test bed to determine the feasibility of detecting explosion-induced geomagnetic disturbances with ground-based induction magnetometers. Two magnetic observatories were fielded at distances of 50 km and 64 km geomagnetically north from the northernmost edge of BTCM. Each observatory consisted of three separate but mutually orthogonal magnetometers, Global Positioning System (GPS) timing, battery and solar power, a data acquisition and storage system, and a three-axis seismometer. Explosions with yields of 1 to 3 kT of TNT equivalent occur approximately every three weeks at BTCM. We hypothesize that explosion-induced acoustic waves propagate upward and interact collisionally with the ionosphere to produce ionospheric electron density (and concomitant current density) perturbations which act as sources for geomagnetic disturbances. These disturbances propagate through an ionospheric Alfven waveguide that we postulate to be leaky (due to the imperfectly conducting lower ionospheric boundary). Consequently, wave energy may be observed on the ground. We observed transient pulses, known as Q-bursts, with pulse widths about 0.5 s and with spectral energy dominated by the Schumann resonances. These resonances appear to be excited in the earth-ionosphere cavity by Alfven solitons that may have been generated by the explosion-induced acoustic waves reaching the ionospheric E and F regions and that subsequently propagate down through the ionosphere to the atmosphere. In addition, we observe late time (> 800 s) ultra low frequency (ULF) geomagnetic perturbations that appear to originate in the upper F region ({approximately}300 km) and appear to be caused by the explosion-induced acoustic wave interacting with that part of the ionosphere. We suggest that explosion-induced Q-bursts may be discriminated from naturally occurring Q-bursts by association of the former with the late time explosion-induced ULF

  10. Chemometrics applications in biotech processes: a review.

    Science.gov (United States)

    Rathore, Anurag S; Bhushan, Nitish; Hadpe, Sandip

    2011-01-01

    Biotech unit operations are often characterized by a large number of inputs (operational parameters) and outputs (performance parameters) along with complex correlations amongst them. A typical biotech process starts with the vial of the cell bank, ends with the final product, and has anywhere from 15 to 30 such unit operations in series. The aforementioned parameters can impact process performance and product quality and also interact amongst each other. Chemometrics presents one effective approach to gather process understanding from such complex data sets. The increasing use of chemometrics is fuelled by the gradual acceptance of quality by design and process analytical technology amongst the regulators and the biotech industry, which require enhanced process and product understanding. In this article, we review the topic of chemometrics applications in biotech processes with a special focus on recent major developments. Case studies have been used to highlight some of the significant applications.

  11. Does chemometrics enhance the performance of electroanalysis?

    Science.gov (United States)

    Ni, Yongnian; Kokot, Serge

    2008-09-26

    This review explores the question whether chemometrics methods enhance the performance of electroanalytical methods. Electroanalysis has long benefited from the well-established techniques such as potentiometric titrations, polarography and voltammetry, and the more novel ones such as electronic tongues and noses, which have enlarged the scope of applications. The electroanalytical methods have been improved with the application of chemometrics for simultaneous quantitative prediction of analytes or qualitative resolution of complex overlapping responses. Typical methods include partial least squares (PLS), artificial neural networks (ANNs), and multiple curve resolution methods (MCR-ALS, N-PLS and PARAFAC). This review aims to provide the practising analyst with a broad guide to electroanalytical applications supported by chemometrics. In this context, after a general consideration of the use of a number of electroanalytical techniques with the aid of chemometrics methods, several overviews follow with each one focusing on an important field of application such as food, pharmaceuticals, pesticides and the environment. The growth of chemometrics in conjunction with electronic tongue and nose sensors is highlighted, and this is followed by an overview of the use of chemometrics for the resolution of complicated profiles for qualitative identification of analytes, especially with the use of the MCR-ALS methodology. Finally, the performance of electroanalytical methods is compared with that of some spectrophotometric procedures on the basis of figures-of-merit. This showed that electroanalytical methods can perform as well as the spectrophotometric ones. PLS-1 appears to be the method of practical choice if the %relative prediction error of approximately +/-10% is acceptable.

  12. Does chemometrics enhance the performance of electroanalysis?

    Energy Technology Data Exchange (ETDEWEB)

    Ni Yongnian [State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, Jiangxi 330047 (China); Department of Chemistry, Nanchang University, Nanchang, Jiangxi 330047 (China)], E-mail: ynni@ncu.edu.cn; Kokot, Serge [Inorganic Materials Research Program, School of Physical and Chemical Sciences, Queensland University of Technology, Brisbane, Queensland 4001 (Australia)

    2008-09-26

    This review explores the question whether chemometrics methods enhance the performance of electroanalytical methods. Electroanalysis has long benefited from the well-established techniques such as potentiometric titrations, polarography and voltammetry, and the more novel ones such as electronic tongues and noses, which have enlarged the scope of applications. The electroanalytical methods have been improved with the application of chemometrics for simultaneous quantitative prediction of analytes or qualitative resolution of complex overlapping responses. Typical methods include partial least squares (PLS), artificial neural networks (ANNs), and multiple curve resolution methods (MCR-ALS, N-PLS and PARAFAC). This review aims to provide the practising analyst with a broad guide to electroanalytical applications supported by chemometrics. In this context, after a general consideration of the use of a number of electroanalytical techniques with the aid of chemometrics methods, several overviews follow with each one focusing on an important field of application such as food, pharmaceuticals, pesticides and the environment. The growth of chemometrics in conjunction with electronic tongue and nose sensors is highlighted, and this is followed by an overview of the use of chemometrics for the resolution of complicated profiles for qualitative identification of analytes, especially with the use of the MCR-ALS methodology. Finally, the performance of electroanalytical methods is compared with that of some spectrophotometric procedures on the basis of figures-of-merit. This showed that electroanalytical methods can perform as well as the spectrophotometric ones. PLS-1 appears to be the method of practical choice if the %relative prediction error of {approx}{+-}10% is acceptable.

  13. Passive acoustic monitoring using a towed hydrophone array results in identification of a previously unknown beaked whale habitat.

    Science.gov (United States)

    Yack, Tina M; Barlow, Jay; Calambokidis, John; Southall, Brandon; Coates, Shannon

    2013-09-01

    Beaked whales are diverse and species rich taxa. They spend the vast majority of their time submerged, regularly diving to depths of hundreds to thousands of meters, typically occur in small groups, and behave inconspicuously at the surface. These factors make them extremely difficult to detect using standard visual survey methods. However, recent advancements in acoustic detection capabilities have made passive acoustic monitoring (PAM) a viable alternative. Beaked whales can be discriminated from other odontocetes by the unique characteristics of their echolocation clicks. In 2009 and 2010, PAM methods using towed hydrophone arrays were tested. These methods proved highly effective for real-time detection of beaked whales in the Southern California Bight (SCB) and were subsequently implemented in 2011 to successfully detect and track beaked whales during the ongoing Southern California Behavioral Response Study. The three year field effort has resulted in (1) the successful classification and tracking of Cuvier's (Ziphius cavirostris), Baird's (Berardius bairdii), and unidentified Mesoplodon beaked whale species and (2) the identification of areas of previously unknown beaked whale habitat use. Identification of habitat use areas will contribute to a better understanding of the complex relationship between beaked whale distribution, occurrence, and preferred habitat characteristics on a relatively small spatial scale. These findings will also provide information that can be used to promote more effective management and conservation of beaked whales in the SCB, a heavily used Naval operation and training region.

  14. Contribution of acoustic emission to monitor the effect of phosphate based inhibitor on the corrosion behavior of steel reinforcement

    Energy Technology Data Exchange (ETDEWEB)

    Nahali, Haifa [Laboratoire MATEIS CNRS UMR5511 (Equipe CorrIS), INSA-Lyon, Villeurbanne (France); Univ. de Tunis El Manar, Belvedere (Tunisia). Unite de Recherche ' ' Mecanique-Energetique' ' ; Dhouibi, Leila [Univ. de Tunis El Manar, Belvedere (Tunisia). Unite de Recherche ' ' Mecanique-Energetique' ' ; Idrissi, Hassane [Laboratoire MATEIS CNRS UMR5511 (Equipe CorrIS), INSA-Lyon, Villeurbanne (France)

    2014-11-01

    One of the most important causes of reinforced concrete structures deterioration is the corrosion of the reinforcement steel. This corrosion depends on the presence of aggressive agents such as chlorides in the surrounding medium. Numerous protection techniques have been employed to mitigate this corrosion. Among them, the use of corrosion inhibitors has been considered as one of the most effective solutions. In the present work, the influence of phosphate based inhibitor on the corrosion of reinforcing steels embedded in mortar, and immersed in sodium chloride solution, was investigated by acoustic emission technique. The monitoring of specimens shows that the phosphate based inhibitor addition in the mortar increase the threshold of chloride concentrations, causing the breakdown of steel passivation layer. Thus, the acoustic signatures of concrete fracture and of structure degradation during the corrosion of these specimens have been highlighted. Similarly, the mechanism of phosphate action in terms of preventing steel from corrosion in mortar specimens was analysed by characterization methods (SEM, XRD) of the steel-mortar interface.

  15. Analysis of Precursors Prior to Rock Burst in Granite Tunnel Using Acoustic Emission and Far Infrared Monitoring

    Directory of Open Access Journals (Sweden)

    Zhengzhao Liang

    2013-01-01

    Full Text Available To understand the physical mechanism of the anomalous behaviors observed prior to rock burst, the acoustic emission (AE and far infrared (FIR techniques were applied to monitor the progressive failure of a rock tunnel model subjected to biaxial stresses. Images of fracturing process, temperature changes of the tunnel, and spatiotemporal serials of acoustic emission were simultaneously recorded during deformation of the model. The b-value derived from the amplitude distribution data of AE was calculated to predict the tunnel rock burst. The results showed that the vertical stress enhanced the stability of the tunnel, and the tunnels with higher confining pressure demonstrated a more abrupt and strong rock burst. Abnormal temperature changes around the wall were observed prior to the rock burst of the tunnel. Analysis of the AE events showed that a sudden drop and then a quiet period could be considered as the precursors to forecast the rock burst hazard. Statistical analysis indicated that rock fragment spalling occurred earlier than the abnormal temperature changes, and the abnormal temperature occurred earlier than the descent of the AE b-value. The analysis indicated that the temperature changes were more sensitive than the AE b-value changes to predict the tunnel rock bursts.

  16. Fabrication of a high performance acoustic emission (AE) sensor to monitor and diagnose disturbances in HTS tapes and magnet systems

    Science.gov (United States)

    Kim, Ju-Hyung; Song, Jung-Bin; Jeong, Young Hun; Lee, Young-Jin; Paik, Jong-Hoo; Kim, Woo-Seok; Lee, Haigun

    2010-02-01

    An acoustic emission (AE) technique was introduced as a non-destructive method to monitor sudden deformation caused by local heat concentrations and micro-cracks within superconductors and superconducting magnets. However, the detection of AE signals in a high temperature superconductor (HTS) tape is not easy because of its low signal to noise ratio caused by the noise from boiling liquid cryogen or mechanical vibration from the cryo-cooler. Therefore, high performance piezoelectric ceramics are needed to improve the sensitivity of the AE sensor. The aim of this study was to improve the piezoelectric and dielectric properties to enhance the performance of an AE sensor. This study examined the effects of Nb2O5 addition (0.0 wt.% to 2.0 wt.%) on the properties of high performance piezoelectric ceramics, Pb(Zr0.54 Ti0.46)O3 + 0.2 wt.% Cr2O3, sintered at 1200 °C for 2 h. The performance was examined with respect to the acoustic emission response of AE sensors manufactured using the specimens with various Nb2O5 contents. Superior sensor performance was obtained for the AE sensors fabricated with the specimens containing 1.0 wt.% to 1.5 wt.% Nb2O5. The performance and characteristics of the AE sensors were in accordance with their piezoelectric and dielectric properties.

  17. Proceedings of a seminar on the potential for LMFBR boiling detection by acoustic/neutronic monitoring, Argonne, Illinois, April 8--9, 1976

    Energy Technology Data Exchange (ETDEWEB)

    Carey, W.M.; Albrecht, R.W.

    1976-06-01

    A seminar involving ten technical presentations by principal investigators was held to assess the current scope of ERDA-sponsored programs to determine the feasibility of sodium-boiling detection in LMFBRs and to establish areas in need of additional research and development. The consensus was that (1) feasibility of boiling detection by acoustic, neutronic, and acoustic/neutronic monitors has been demonstrated in U.S. and European programs; (2) additional research and development is needed in areas of reactor noise, cavitation, and the effects of noncondensible gases on sound source levels and transmission; (3) the role of acoustic/neutronic monitors from the standpoint of reactor surveillance rather than reactor safety is a viable approach to be adapted; and, in particular (4) a need exists for an operational LMFBR demonstration system. Each paper has been separately abstracted and indexed. (DG)

  18. Acoustic emission monitoring of fracture process of SiC/Al composites under cyclic loading

    Science.gov (United States)

    Lee, Joon-Hyun; Kim, Jong-Hwan; Yoon, Dong-Jin; Kwon, Oh-Yang

    Acoustic emission was used to clarify fatigue failure mechanisms of aliminum alloys reinforced with SiC particulate (SiCp/A356) or whisker (SiCw/Al2009). For this purpose, special attention was given to AE characteristics including AE event, energy and peak amplitude distribution which were associated with micro-fracture processes of metal matrix composites under the cyclic loading. The effects of form of reinforcements, heat treatment, orientation of whisker and loading condition on AE characteristics were discussed based on SEM fractographic results.

  19. Development of a Surface Acoustic Wave Sensor for In-Situ Monitoring of Volatile Organic Compounds

    Directory of Open Access Journals (Sweden)

    Jerome L. Wright

    2003-07-01

    Full Text Available This paper describes the development of a surface-acoustic-wave (SAW sensor that is designed to be operated continuously and in situ to detect volatile organic compounds. A ruggedized stainless-steel package that encases the SAW device and integrated circuit board allows the sensor to be deployed in a variety of media including air, soil, and even water. Polymers were optimized and chosen based on their response to chlorinated aliphatic hydrocarbons (e.g., trichloroethylene, which are common groundwater contaminants. Initial testing indicates that a running-average data-logging algorithm can reduce the noise and increase the sensitivity of the in-situ sensor.

  20. A methodological review of piezoelectric based acoustic wave generation and detection techniques for structural health monitoring

    National Research Council Canada - National Science Library

    Sun, Z; Rocha, B; Wu, K.-T; Mrad, N

    2013-01-01

    .... As condition based maintenance has emerged as a valuable approach to enhancing continued aircraft airworthiness while reducing the life cycle cost, its enabling structural health monitoring (SHM...

  1. Assessment of the application of acoustic emission technology for monitoring the presence of sand under multiphase flow condition

    Energy Technology Data Exchange (ETDEWEB)

    El-Alej, M., E-mail: m.elalej@cranfield.ac.uk; Mba, D., E-mail: m.elalej@cranfield.ac.uk; Yeung, H., E-mail: m.elalej@cranfield.ac.uk [School of Engineering, Cranfield University, Cranfield, Bedfordshire, MK43 OAL (United Kingdom)

    2014-04-11

    The monitoring of multiphase flow is an established process that has spanned several decades. This paper demonstrates the use of acoustic emission (AE) technology to investigate sand transport characteristic in three-phase (air-water-sand) flow in a horizontal pipe where the superficial gas velocity (VSG) had a range of between 0.2 ms{sup −1} to 2.0 ms{sup −1} and superficial liquid velocity (VSL) had a range of between 0.2 ms{sup −1} to 1.0 ms{sup −1}. The experimental findings clearly show a correlation exists between AE energy levels, sand concentration, superficial gas velocity (VSG) and superficial liquid velocity (VSL)

  2. Hydro-seismic-acoustical monitoring of submarine earthquakes preparation: observations and analysis

    Directory of Open Access Journals (Sweden)

    E. V. Sasorova

    2008-01-01

    Full Text Available The results of laboratory experiments on rock sample destruction and the observation data obtained from several series of the hydro-acoustic observations in which the researchers succeeded to register the signals in the critical stage of the earthquake (EQ preparation were compared. According to theoretical research (Alekseev et al., 2001 two distinct dilatant zones occur in the EQ preparation stage. The first one is located around the source and the second one represents the near-surface dilatant zone. Only high-frequency seismic-acoustic signals (SAS radiated from the near-surface dilatant zone do not attenuate completely on the passage through a solid medium. Parameters of the SAS such as the source depth under the ocean floor, frequency maximum and the signal power level were estimated. It was shown that the critical stage of the EQ preparation continues several tens hours and this process has a hierarchical nature. At first the micro-ruptures are formed over a large area. Then the high frequency radiation begins to decrease, the SAS emission area begins to shrink and the micro-earthquakes occur in the area surrounding the epicenter. The obtained results are in close agreement with the theoretical conception about the evolution of the SAS in the surface dilatant zone and with the results of laboratory experiments.

  3. Comparison of optical and acoustical monitoring during a crack propagation, implication for slow earthquake dynamics

    Science.gov (United States)

    Lengliné, Olivier; Schmittbuhl, Jean; Elkhoury, Jean; Toussaint, Renaud; Daniel, Guillaume; Maloy, Knut Jurgen

    2010-05-01

    Observations of aseismic transients in several tectonic context suggest that they might be linked to seismicity. However a clear observation and description of these phenomena and their interaction is lacking. This owes to the difficulty of characterizing with a sufficient resolution processes taking place at depth. Here we aim to study these interactions between aseismic and seismic slip taking advantage of an unique experimental setup. We conducted a series of mode I crack propagation experiments on transparent materials (PMMA). The crack advance is trapped in a weakness plane which is the interface between two previously sandblasted and annealed plexiglass plates. A fast video camera taking up to 500 frames per second ensures the tracking of the front rupture. The acoustic system is composed of a maximum of 44 channels continuously recording at 5 MHz for a few tens of seconds. Piezo-electric sensors are composed of a 32 elements linear array and individual sensors surrounding the crack front. An automatic detection and localization procedure allows us to obtain the position of acoustic emission (A.E.) that occurred during the crack advance. Crack front image processing reveals an intermittent opening which might be linked to the time and space clustering of the AE. An analogy between the mode I (opening) and the mode III (antiplane slip) allows us to interpret our results in term of slip on faults. Our experiment thus helps to reveal the interplay between seismic and aseismic slip on faults.

  4. A new strategy toward Internet of Things: structural health monitoring using a combined fiber optic and acoustic emission wireless sensor platform

    Science.gov (United States)

    Nguyen, A. D.; Page, C.; Wilson, C. L.

    2016-04-01

    This paper investigates a new low-power structural health monitoring (SHM) strategy where fiber Bragg grating (FBG) rosettes can be used to continuously monitor for changes in a host structure's principal strain direction, suggesting damage and thus enabling the immediate triggering of a higher power acoustic emissions (AE) sensor to provide for better characterization of the damage. Unlike traditional "always on" AE platforms, this strategy has the potential for low power, while the wireless communication between different sensor types supports the Internet of Things (IoT) approach. A combination of fiber-optic sensor rosettes for strain monitoring and a fiber-optic sensor for acoustic emissions monitoring was attached to a sample and used to monitor crack initiation. The results suggest that passive principal strain direction monitoring could be used as a damage initiation trigger for other active sensing elements such as acoustic emissions. In future work, additional AE sensors can be added to provide for damage location; and a strategy where these sensors can be powered on periodically to further establish reliability while preserving an energy efficient scheme can be incorporated.

  5. Acoustic monitoring using bamboo set net in the Southern Sea of Korea

    Science.gov (United States)

    Lee, Hyungbeen; Lee, Kyounghoon; La, Hyoung Sul; Yang, Yongsu; Kim, Pyungkwan

    2017-01-01

    High-temporal resolution profiles of acoustic backscatter were collected from a traditional bamboo set net along the coast of the Southern Sea, Korea, using sideward-looking multi-beam imaging sonar. These data were used to examine the impact of variations in tidal cycles and current speeds on the bamboo set net. The relatively high influx of fish during the nighttime compared to the low influx and high outflux of fish during the daytime suggests visual avoidance of the net by the fish during the daytime. The observed diel variation in the captured fish flux was significantly correlated with the current speed (day: r = 0.35, p = 0.002, night: r = 0.60, p bamboo set nets appears to be greatly influenced by day-night differences and current speed. The present study enhances understanding of fish behavior via utilization of a bamboo set net in the coastal zone.

  6. Effect of click-polarity on abnormality of intraoperatively monitored brainstem acoustic evoked potentials.

    Science.gov (United States)

    Mokrusch, T; Schramm, J; Hochstetter, A

    1988-01-01

    The configuration of brainstem acoustic evoked potentials (BAEP) is influenced by the type of click stimuli used and may thus affect detectability of abnormalities. In a group of 19 patients with lesions in the posterior fossa BAEP were recorded pre- and intraoperatively. Repeat recordings were performed in each patient in two alternating series with rarefaction and condensation click stimuli. The findings demonstrated that intraoperative potential changes in latency and amplitude were different between the two stimulation modes, but did not vary significantly in their incidence. It was also not possible to predict from the preoperative BAEP which click polarity would demonstrate intraoperative changes more markedly, taking latency and amplitude as parameters. Two conclusions are drawn from this study: None of the two stimulation modes is superior in detecting intraoperative changes and therefore no recommendation can be made which click polarity to use. When working with only one click polarity it is recommended to use occasional control recordings with the other click polarity.

  7. Monitoring of quality and stability characteristics and fatty acid compositions of refined olive and seed oils during repeated pan- and deep-frying using GC, FT-NIRS, and chemometrics.

    Science.gov (United States)

    Zribi, Akram; Jabeur, Hazem; Aladedunye, Felix; Rebai, Ahmed; Matthäus, Bertrand; Bouaziz, Mohamed

    2014-10-22

    Refined olive, corn, soybean, and sunflower oils were used as cooking oils for deep-frying at two different temperatures, 160 and 190 °C, and for pan-frying of potatoes at 180 °C for 10 successive sessions under the usual domestic practice. Several chemical parameters were assayed during frying operations to evaluate the status of the frying oils. Refined olive oil, as frying oil, was found to be more stable than the refined seed oils. In fact, this oil has proven the greatest resistance to oxidative deterioration, and its trans-fatty acid contents and percentages of total polar compounds were found to be lower at 160 °C during deep-frying. Finally, chemometric analysis has demonstrated that the lowest deterioration of the quality of all refined oils occurred in the refined olive oil during deep-frying at 160 °C and the highest deterioration occurred in the refined sunflower oil during pan-frying at 180 °C.

  8. Acoustic chemometric prediction of total solids in bioslurry

    DEFF Research Database (Denmark)

    Ihunegbo, Felicia; Madsen, Michael; Esbensen, Kim

    2012-01-01

    performance of the optimised process implementation was evaluated using independent test set validation, with estimates of accuracy (slope of predicted vs. reference values) and precision (squared correlation coefficient, r2) of 0.94 and 0.97 respectively, with RMSEP of 0.32% w/w (RMSEPrel = 3.86...

  9. Semi-real-time monitoring of cracking on couplings by neural network analysis of acoustic emission signals

    Science.gov (United States)

    Godinez-Azcuaga, Valery F.; Shu, Fong; Finlayson, Richard D.; O'Donnell, Bruce W.

    2004-07-01

    This paper presents the results obtained during the development of a semi-real-time monitoring methodology based on Neural Network Pattern Recognition of Acoustic Emission (AE) signals for early detection of cracks in couplings used in aircraft and engine drive systems. AE signals were collected in order to establish a baseline of a gear-testing fixture background noise and its variations due to rotational speed and torque. Also, simulated cracking signals immersed in background noise were collected. EDM notches were machined in the driving gear and the load on the gearbox was increased until damaged was induced. Using these data, a Neural Network Signal Classifier (NNSC) was implemented and tested. The testing showed that the NNSC was capable of correctly identifying six different classes of AE signals corresponding to different gearbox operation conditions. Also, a semi-real-time classification software was implemented. This software includes functions that allow the user to view and classify AE data from a dynamic process as they are recorded at programmable time intervals. The software is capable of monitoring periodic statistics of AE data, which can be used as an indicator of damage presence and severity in a dynamic system. The semi-real-time classification software was successfully tested in situations where a delay of 10 seconds between data acquisition and classification was achieved with a hit rate of 50 hits/second per channel on eight active AE channels.

  10. Characterizing Focused-Ultrasound Mediated Drug Delivery to the Heterogeneous Primate Brain In Vivo with Acoustic Monitoring

    Science.gov (United States)

    Wu, Shih-Ying; Sanchez, Carlos Sierra; Samiotaki, Gesthimani; Buch, Amanda; Ferrera, Vincent P.; Konofagou, Elisa E.

    2016-11-01

    Focused ultrasound with microbubbles has been used to noninvasively and selectively deliver pharmacological agents across the blood-brain barrier (BBB) for treating brain diseases. Acoustic cavitation monitoring could serve as an on-line tool to assess and control the treatment. While it demonstrated a strong correlation in small animals, its translation to primates remains in question due to the anatomically different and highly heterogeneous brain structures with gray and white matteras well as dense vasculature. In addition, the drug delivery efficiency and the BBB opening volume have never been shown to be predictable through cavitation monitoring in primates. This study aimed at determining how cavitation activity is correlated with the amount and concentration of gadolinium delivered through the BBB and its associated delivery efficiency as well as the BBB opening volume in non-human primates. Another important finding entails the effect of heterogeneous brain anatomy and vasculature of a primate brain, i.e., presence of large cerebral vessels, gray and white matter that will also affect the cavitation activity associated with variation of BBB opening in different tissue types, which is not typically observed in small animals. Both these new findings are critical in the primate brain and provide essential information for clinical applications.

  11. Highly sensitive monitoring of chest wall dynamics and acoustics provides diverse valuable information for evaluating ventilation and diagnosing pneumothorax.

    Science.gov (United States)

    Pesin, Jimy; Faingersh, Anna; Waisman, Dan; Landesberg, Amir

    2014-06-15

    Current practice of monitoring lung ventilation in neonatal intensive care units, utilizing endotracheal tube pressure and flow, end-tidal CO2, arterial O2 saturation from pulse oximetry, and hemodynamic indexes, fails to account for asymmetric pathologies and to allow for early detection of deteriorating ventilation. This study investigated the utility of bilateral measurements of chest wall dynamics and sounds, in providing early detection of changes in the mechanics and distribution of lung ventilation. Nine healthy New Zealand rabbits were ventilated at a constant pressure, while miniature accelerometers were attached to each side of the chest. Slowly progressing pneumothorax was induced by injecting 1 ml/min air into the pleural space on either side of the chest. The end of the experiment (tPTX) was defined when arterial O2 saturation from pulse oximetry dropped ventilation was attained for all animals. Side identification of the pneumothorax was achieved at 50% tPTX, within a 95% confidence interval. Diagnosis was, on average, 34.1 ± 18.8 min before tPTX. In conclusion, bilateral monitoring of the chest dynamics and acoustics provide novel information that is sensitive to asymmetric changes in ventilation, enabling early detection and localization of pneumothorax.

  12. Real-time electro-mechano-acoustic imaging for monitoring interactions between trypsin and different inhibitors in articular cartilage.

    Science.gov (United States)

    Zheng, Yong-Ping; Wang, Qing; Butt, Yoki Kwok Chu

    2011-03-01

    The purpose of this study was to observe the real-time interactions between trypsin and various inhibitors in articular cartilage in vitro using a novel electro-mechano-acoustic imaging method. Monitored in real-time, articular cartilage specimens from bovine patellae were first treated with trypsin to reach half proteoglycan depletion (Phase I), then the trypsin solution was replaced with (i) physiological saline buffer (PS), (ii) fetal bovine serum (FBS), (iii) protease inhibitor cocktail (PI) and (iv) 10% formalin (F), respectively, to observe their effects on residual digestion (Phase II). Ultrasound radio frequency signals from the articular cartilage were used to form a M-mode image, where the interface between trypsin digested and intact cartilage tissues could be observed with an additional echo generated. The inhibition time, the digestion depth and digestion fraction were measured for each specimen. The results showed that the dilution of trypsin using saline solution was not sufficient to stop the enzyme action instantly. Although groups FBS and PI had a similar inhibition time of approximately 1.5 h, their digestion depth was obviously different (0.25±0.03 and 0.06±0.06 mm, respectively). In contrast, formalin only took <30 min to stop the trypsin digestion with almost no further digestion. The results demonstrated that the current system was capable of monitoring the trypsin digestion and inhibition process in real time. Also, different chemicals affected the residual trypsin digestion to different degrees.

  13. Monitoring the habitat use of common Bottlenose Dolphins (Tursiops truncatus using passive acoustics in a Mediterranean marine protected area

    Directory of Open Access Journals (Sweden)

    G. LA MANNA

    2014-07-01

    Full Text Available The Mediterranean Tursiops truncatus subpopulation has been classified as Vulnerable on the IUCN Red List because of its decline. This species in coastal areas is exposed to a wide variety of threats: directed kills, bycatch, reduced prey availability caused by environmental degradation and overfishing, habitat degradation including disturbances from boat traffic and noise. Despite the increase in boat traffic in the Mediterranean Sea, the effect on T. truncatus’ habitat use has been studied in little detail and few data have been published. This study represents the first attempt to characterise spatial and temporal habitat use by T. truncatus and its relation to boat traffic in the Isole Pelagie Marine Protected Area (Italy on the basis of an originally developed passive acoustic monitoring system (PAM. The devices were deployed in 2 areas in the southern waters of Lampedusa, during 2 separate years (2006 and 2009, each time for 3 months (from July to September and in 6 time slots (3 diurnal and 3 nocturnal. Acoustic analysis showed that T. truncatus used the Southern coastal area of Lampedusa independently of the year, primarily during the early summer, a period coinciding with the peak of calving season. Dolphin occurrences appeared independent of boat traffic, with the exception of the smallest temporal scale (time slots: dolphin occurrences were more prevalent during the night when the level of boat traffic was lower. This study provides evidence on T. truncatus habitat use in the Mediterranean Sea and reveals that boat traffic could be one of the factors influencing it, thus stressing the need for further detailed investigation regarding this topic.

  14. Supervised and unsupervised condition monitoring of non-stationary acoustic emission signals

    DEFF Research Database (Denmark)

    Sigurdsson, Sigurdur; Pontoppidan, Niels Henrik; Larsen, Jan

    2005-01-01

    We are pursuing a system that monitors the engine condition under multiple load settings, i.e. under non-stationary operating conditions. The running speed when data acquired under simulated marine conditions (different load settings on the propeller curve) was in the range from approximately 70...... approaches perform well, which indicates that unsupervised models, modelled without faulty data, may be used for accurate condition monitoring....... condition changes across load changes. In this paper we approach this load interpolation problem with supervised and unsupervised learning, i.e. model with normal and fault examples and normal examples only, respectively. We apply non-linear methods for the learning of engine condition changes. Both...

  15. Breaking the sound barrier? Pitfalls and benefits of acoustic cough monitoring.

    Science.gov (United States)

    Houghton, Lesley A; Smith, Jaclyn A

    2012-12-01

    Traditionally push-button and symptom diaries have been used to document cough events, especially when examining temporal associations between cough and reflux events. More recently, acoustic devices have allowed more accurate recording of cough events, and compared with the latter traditional techniques reported 6-18 times more coughing. Whether the differences reported between these techniques represents disparities in subject groups or cough detection and quantification methods is unknown. In this issue of the American Journal of Gastroenterology, Kavitt et al. show that listeners of such recordings have a 4-fold increase in odds of recording cough events compared with patients using push-button techniques, and that even when using a 5-min window to assess temporal concordance/discordance, over 70% of coughs were not reported by the patients. These observations have potential significant implications when assessing temporal associations between cough and reflux, and thus any clinical decision making based on these data. This editorial examines both the findings of Kavitt et al. and discusses the pitfalls and benefits of validated accurate documentation of cough.

  16. Aquatic Acoustic Metrics Interface Utility for Underwater Sound Monitoring and Analysis

    Directory of Open Access Journals (Sweden)

    Thomas J. Carlson

    2012-05-01

    Full Text Available Fishes and marine mammals may suffer a range of potential effects from exposure to intense underwater sound generated by anthropogenic activities such as pile driving, shipping, sonars, and underwater blasting. Several underwater sound recording (USR devices have been built to acquire samples of the underwater sound generated by anthropogenic activities. Software becomes indispensable for processing and analyzing the audio files recorded by these USRs. In this paper, we provide a detailed description of a new software package, the Aquatic Acoustic Metrics Interface (AAMI, specifically designed for analysis of underwater sound recordings to provide data in metrics that facilitate evaluation of the potential impacts of the sound on aquatic animals. In addition to the basic functions, such as loading and editing audio files recorded by USRs and batch processing of sound files, the software utilizes recording system calibration data to compute important parameters in physical units. The software also facilitates comparison of the noise sound sample metrics with biological measures such as audiograms of the sensitivity of aquatic animals to the sound, integrating various components into a single analytical frame. The features of the AAMI software are discussed, and several case studies are presented to illustrate its functionality.

  17. Acoustic cavitation-based monitoring of the reversibility and permeability of ultrasound-induced blood-brain barrier opening

    Science.gov (United States)

    Sun, Tao; Samiotaki, Gesthimani; Wang, Shutao; Acosta, Camilo; Chen, Cherry C.; Konofagou, Elisa E.

    2015-12-01

    Cavitation events seeded by microbubbles have been previously reported to be associated with MR- or fluorescent-contrast enhancement after focused ultrasound (FUS)-induced blood-brain barrier (BBB) opening. However, it is still unknown whether bubble activity can be correlated with the reversibility (the duration of opening and the likelihood of safe reinstatement) and the permeability of opened BBB, which is critical for the clinical translation of using passive cavitation detection to monitor, predict and control the opening. In this study, the dependence of acoustic cavitation on the BBB opening duration, permeability coefficient and histological damage occurrence were thus investigated. Transcranial pulsed FUS at 1.5 MHz in the presence of systemically circulating microbubbles was applied in the mouse hippocampi (n  =  60). The stable and inertial cavitation activities were monitored during sonication. Contrast-enhanced MRI was performed immediately after sonication and every 24 h up to 6 d thereafter, to assess BBB opening, brain tissue permeability and potential edema. Histological evaluations were used to assess the occurrence of neurovascular damages. It was found that stable cavitation was well correlated with: (1) the duration of the BBB opening (r2  =  0.77) (2) the permeability of the opened BBB (r2  =  0.82) (3) the likelihood of safe opening (P  drug circulation time. In addition, avoiding adverse effects in the brain and assessing the pharmacokinetics of the compounds delivered can also be achieved by monitoring and controlling the stable cavitation emissions.

  18. Monitoring fin whale (Balaenoptera physalus) acoustic presence by means of a low frequency seismic hydrophone in Western Ionian Sea, EMSO site.

    Science.gov (United States)

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

    2015-04-01

    In 2012, the NEMO-SN1 multidisciplinary seafloor platform was deployed in the Gulf of Catania at a depth of 2100 m. By using the low bandwidth seismic hydrophone SMID DT405D (1Hz whales (Balaenoptera physalus) acoustic activity in the area. The presence of a genetically isolated population of fin whales has been confirmed in recent years in highly productive areas of the Mediterranean Sea. The species acoustic activity has also been monitored in the past within the Western Mediterranean. Despite this, still very little is known about the routes the population follows seasonally throughout the whole basin and, particularly, in the Ionian area. The most common vocalizations attributed to this population are known as "20Hz pulses" and they are grouped in two main types of calls: type "A", downsweep (17Hz whale acoustic signals, recorded for the first time in the area. Furthermore, our results show a previous unknown acoustic presence of fin whales offshore Eastern Sicily throughout all seasons of the investigated year. The new long-term multidisciplinary projects connected to "KM3NeT" and "EMSO" will give us the chance to better understand the animals' occurrence in the area and to investigate their acoustic behavior and population dynamics.

  19. Air-quality monitoring by optical and acoustic radars at Pune, India

    Science.gov (United States)

    Devara, P. C. S.; Maheskumar, R. S.; Murthy, B. S.; Vernekar, K. G.

    1997-10-01

    The co-located optical (argon-ion lidar) and acoustic (Doppler sodar) radar systems at the Indian Institute of Tropical Meteorology (IITM), Pune (0957-0233/8/10/019/img1, 0957-0233/8/10/019/img2, 559 m AMSL), India, have been employed to study the nocturnal aerosol pollution dynamics or air quality. Both the systems have been operated simultaneously in order to sample the common atmospheric volume. The results of the experiments thus conducted on some typical nights are presented in this paper. The time - height cross section of the mean, horizontal and vertical components of the wind field derived from the sodar observations indicate that the wind is either easterly or northerly with its vertical component negative (downdraft) for most of the observational period. The interesting feature is that the winds are either calm or relatively weaker in the night-time boundary layer compared with those in the region aloft. This is more evident in the north - south direction in which the lidar and sodar equipment are located. Furthermore, the regions where stable/elevated layer formation is active are found to be associated with the smallest wind gradients, leading to accumulation of aerosol particles or larger temperature structure parameters. The time evolution of the mixed-layer heights and the associated ventilation coefficients, determined from the combined lidar - aerosol and sodar - wind observations, are found to be useful to explain the transport and diffusion of pollutants across the elevated temperature inversions over the experimental station. The details of the experimental techniques are presented and their value for application in the study of regional air quality and pollution potential is discussed.

  20. Acoustic monitoring (RFM of total hip arthroplasty results of a cadaver study

    Directory of Open Access Journals (Sweden)

    Unger AC

    2009-06-01

    Full Text Available Abstract Introduction At present there are no reliable non-traumatic and non-invasive methods to analyse the healing process and loosening status after total hip replacement. Therefore early as well as late loosening of prosthesis and interface component problems are difficult to be found or diagnosed at any time. Methods In a cadaver study the potential application of Resonance Frequency Monitoring (RFM will be evaluated as a non-invasive and non-traumatic method to monitor loosening and interface problems in hip replacement. In a 65 year old female cadaver different stability scenarios for a total hip replacement (shaft, head/modular head and cup, ESKA, Luebeck, Germany are simulated in cemented and cement less prosthesis and then analysed with RFM. The types of stability vary from secure/press-fit to interface-shaft disruption. Results The RFM shows in cemented as well as cement less prosthesis significant intra-individual differences in the spectral measurements with a high dynamic (20 dB difference corresponding to the factor 100 (10000%, regarding the simulated status of stability in the prosthesis system. Conclusion The results of the study demonstrate RFM as a highly sensitive non-invasive and non-traumatic method to support the application of RFM as a hip prosthesis monitoring procedure. The data obtained shows the possibility to use RFM for osteointegration surveillance and early detection of interface problems, but will require further evaluation in clinical and experimental studies.

  1. Application of fluorescence spectroscopy and chemometrics in the evaluation of processed cheese during storage.

    Science.gov (United States)

    Christensen, J; Povlsen, V T; Sørensen, J

    2003-04-01

    Front face fluorescence spectroscopy is applied for an evaluation of the stability of processed cheese during storage. Fluorescence landscapes with excitation from 240 to 360 nm and emission in the range of 275 to 475 nm were obtained from cheese samples stored in darkness and light in up to 259 d, at 5, 20 and 37 degrees C, respectively. Parallel factor (PARAFAC) analysis of the fluorescence landscapes exhibits four fluorophores present in the cheese, all related to the storage conditions. The chemometric analysis resolves the fluorescence signal into excitation and emission profiles of the pure fluorescent compounds, which are suggested to be tryptophan, vitamin A and a compound derived from oxidation. Thus, it is concluded that fluorescence spectroscopy in combination with chemometrics has a potential as a fast method for monitoring the stability of processed cheese.

  2. Chemometrics and modernization of traditional Chinese medicine

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Development of chromatographic fingerprinting and its related chemometric methods in the research of quality control of traditional Chinese medicines(TCMs) are discussed. The quality control methods for guarantying the authentication and stability of products and semi-products of TCMs are firstly assessed. The technique based on chromatographic fingerprinting is essentially a kind of high-through put and integral tools to explore the complexity of herbal medicines. In order to further control the comprehensive quality of TCMs,confirmation and identification of their important chemical components are necessary. Some new strategies are proposed to trace the chemical changes of chromatographic fingerprints both in product processing and/or after their administration by modern chromatographic techniques and chemometrics. Combined with systems biology and bioinformatics,it seems possible for one to reveal the working mechanism of TCMs and to further control their intrinsic quality comprehensively.

  3. Functional Data Analysis Applied in Chemometrics

    DEFF Research Database (Denmark)

    Muller, Martha

    the worlds of statistics and chemometrics. We want to provide a glimpse of the essential and complex data pre-processing that is well known to chemometricians, but is generally unknown to statisticians. Pre-processing can potentially have a strong in uence on the results of consequent data analysis. Our......In this thesis we explore the use of functional data analysis as a method to analyse chemometric data, more specically spectral data in metabolomics. Functional data analysis is a vibrant eld in statistics. It has been rapidly expanding in both methodology and applications since it was made well...... known by Ramsay & Silverman's monograph in 1997. In functional data analysis, the data are curves instead of data points. Each curve is measured at discrete points along a continuum, for example, time or frequency. It is assumed that the underlying process generating the curves is smooth...

  4. Functional Data Analysis Applied in Chemometrics

    DEFF Research Database (Denmark)

    Muller, Martha

    In this thesis we explore the use of functional data analysis as a method to analyse chemometric data, more specically spectral data in metabolomics. Functional data analysis is a vibrant eld in statistics. It has been rapidly expanding in both methodology and applications since it was made well...... known by Ramsay & Silverman's monograph in 1997. In functional data analysis, the data are curves instead of data points. Each curve is measured at discrete points along a continuum, for example, time or frequency. It is assumed that the underlying process generating the curves is smooth......, but it is not assumed that the adjacent points measured along the continuum are independent. Standard chemometric methods originate from the eld of multivariate analysis, where variables are often assumed to be independent. Typically these methods do not explore the rich functional nature of spectral data. Metabolomics...

  5. Aspects of recent developments in analytical chemometrics

    Institute of Scientific and Technical Information of China (English)

    LIANG; Yizeng; WU; Hailong; SHEN; Guoli; JIANG; Jianhui; LIANG; Sheng

    2006-01-01

    Some aspects of recent developments in analytical chemometrics are discussed, in particular the developments viewed from the angle of the research efforts undertaken in authors' laboratories. The topics concerned include resolution of high-order chemical data, morphological theory and methodology for chemical signal processing, multivariate calibration and chemical pattern recognition for solving complex chemical problems, and resolution of two-way chemical data from hyphenated chromatographic instruments.

  6. Near-Real-Time Sismo-acoustic Submarine Station for offshore monitoring

    Science.gov (United States)

    D'Anna, Giuseppe; D'Alessandro, Antonino; Fertitta, Gioacchino; Fraticelli, Nicola; Calore, Daniele

    2016-04-01

    From the early 1980's, Italian seismicity is monitored by the National Seismic Network (NSN). The network has been considerably enhanced by INGV since 2005 by 24-bit digital stations equipped with broad-band sensors. The NSN is nowadays constituted by about 300 on-land seismic station able to detect and locate also small magnitude earthquake in the whole Italian peninsula. However, the lack of offshore seismic stations does not allow the accurate estimation of hypocentral and focal parameters of small magnitude earthquakes occurring in offshore areas. As in the Mediterranean area there is an intense offshore seismic activity, an extension of the seismic monitoring to the sea would be beneficial. There are two types of stations that could be used to extend the network towards the sea: the first type is connected to the coast though a cable, the second type is isolated (or stand alone) and works autonomously. Both solutions have serious limitations: the first one, for several technical and economic problems, linked to the indispensable transmission/alimentation cable, cannot be installed far from the coast; the second one, allows access to the recorded data, only after they are recovered from the seabed. It is clear that these technical solutions are not suitable for the real time monitoring of the offshore seismicity or for the realization of a tsunami warning system. For this reason, in early 2010, the OBSLab of Gibilmanna begins the design of a submarine station able to overcome the limitations of the two systems above. The station isbuilt under the project EMSO-MedIT. The two stations built have already been tested in dock and ready for installation. One of this station will be installed, in few time, in the southern Tyrrhenian Sea, near the epicentre of the Palermo 2002 main shock. The sea bottom station will be equipped with 2 very broadband 3C seismometers, a broad band hydrophone, a differential and an absolute pressure gauge. The station includes a submarine

  7. Indoor acoustic gain design

    Science.gov (United States)

    Concha-Abarca, Justo Andres

    2002-11-01

    The design of sound reinforcement systems includes many variables and usually some of these variables are discussed. There are criteria to optimize the performance of the sound reinforcement systems under indoor conditions. The equivalent acoustic distance, the necessary acoustic gain, and the potential acoustic gain are parameters which must be adjusted with respect to the loudspeaker array, electric power and directionality of loudspeakers, the room acoustics conditions, the distance and distribution of the audience, and the type of the original sources. The design and installation of front of the house and monitoring systems have individual criteria. This article is about this criteria and it proposes general considerations for the indoor acoustic gain design.

  8. Using Nano-mechanics and Surface Acoustic Wave (SAW) for Disease Monitoring and Diagnostics at a Cellular Level in Red Blood Cells

    Science.gov (United States)

    Sivanantha, Ninnuja; Ma, Charles; Collins, David J.; Sesen, Muhsincan; Brenker, Jason; Coppel, Ross L.; Neild, Adrian; Alan, Tuncay

    A popular approach to monitoring diseases and their diagnosis is through biological, pathological or immunological characterization. However, at a cellular level progression of certain diseases manifests itself through mechanical effects as well. Here, we present a method which exploits localised flow; surface acoustic wave (SAW) induced acoustic streaming in a 9 μL droplet to characterize the adhesive properties of red blood cells (healthy, gluteraldehyde treated and malaria infected) in approximately 50 seconds. Our results show a 79% difference in cell mobilization between healthy malaria infected RBCs (and a 39% difference between healthy and treated ones), indicating that the method can serve as a platform for rapid clinical diagnosis; where separation of two or more different cell populations in a mixed solution is desirable. It can also act as a key biomarker for monitoring some diseases offering quantitative measures of disease progression and response to therapy.

  9. Seafloor monitoring west of Helgoland (German Bight, North Sea) using the acoustic ground discrimination system RoxAnn

    Science.gov (United States)

    Hass, H. Christian; Mielck, Finn; Fiorentino, Dario; Papenmeier, Svenja; Holler, Peter; Bartholomä, Alexander

    2017-04-01

    Marine habitats of shelf seas are in constant dynamic change and therefore need regular assessment particularly in areas of special interest. In this study, the single-beam acoustic ground discrimination system RoxAnn served to assess seafloor hardness and roughness, and combine these parameters into one variable expressed as RGB (red green blue) color code followed by k-means fuzzy cluster analysis (FCA). The data were collected at a monitoring site west of the island of Helgoland (German Bight, SE North Sea) in the course of four surveys between September 2011 and November 2014. The study area has complex characteristics varying from outcropping bedrock to sandy and muddy sectors with mostly gradual transitions. RoxAnn data enabled to discriminate all seafloor types that were suggested by ground-truth information (seafloor samples, video). The area appears to be quite stable overall; sediment import (including fluid mud) was detected only from the NW. Although hard substrates (boulders, bedrock) are clearly identified, the signal can be modified by inclination and biocover. Manually, six RoxAnn zones were identified; for the FCA, only three classes are suggested. The latter classification based on `hard' boundaries would suffice for stakeholder issues, but the former classification based on `soft' boundaries is preferred to meet state-of-the-art scientific objectives.

  10. 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.

  11. High-Speed Edge Trimming of CFRP and Online Monitoring of Performance of Router Tools Using Acoustic Emission.

    Science.gov (United States)

    Prakash, Rangasamy; Krishnaraj, Vijayan; Zitoune, Redouane; Sheikh-Ahmad, Jamal

    2016-09-26

    Carbon fiber reinforced polymers (CFRPs) have found wide-ranging applications in numerous industrial fields such as aerospace, automotive, and shipping industries due to their excellent mechanical properties that lead to enhanced functional performance. In this paper, an experimental study on edge trimming of CFRP was done with various cutting conditions and different geometry of tools such as helical-, fluted-, and burr-type tools. The investigation involves the measurement of cutting forces for the different machining conditions and its effect on the surface quality of the trimmed edges. The modern cutting tools (router tools or burr tools) selected for machining CFRPs, have complex geometries in cutting edges and surfaces, and therefore a traditional method of direct tool wear evaluation is not applicable. An acoustic emission (AE) sensing was employed for on-line monitoring of the performance of router tools to determine the relationship between AE signal and length of machining for different kinds of geometry of tools. The investigation showed that the router tool with a flat cutting edge has better performance by generating lower cutting force and better surface finish with no delamination on trimmed edges. The mathematical modeling for the prediction of cutting forces was also done using Artificial Neural Network and Regression Analysis.

  12. Seafloor monitoring west of Helgoland (German Bight, North Sea) using the acoustic ground discrimination system RoxAnn

    Science.gov (United States)

    Hass, H. Christian; Mielck, Finn; Fiorentino, Dario; Papenmeier, Svenja; Holler, Peter; Bartholomä, Alexander

    2016-11-01

    Marine habitats of shelf seas are in constant dynamic change and therefore need regular assessment particularly in areas of special interest. In this study, the single-beam acoustic ground discrimination system RoxAnn served to assess seafloor hardness and roughness, and combine these parameters into one variable expressed as RGB (red green blue) color code followed by k-means fuzzy cluster analysis (FCA). The data were collected at a monitoring site west of the island of Helgoland (German Bight, SE North Sea) in the course of four surveys between September 2011 and November 2014. The study area has complex characteristics varying from outcropping bedrock to sandy and muddy sectors with mostly gradual transitions. RoxAnn data enabled to discriminate all seafloor types that were suggested by ground-truth information (seafloor samples, video). The area appears to be quite stable overall; sediment import (including fluid mud) was detected only from the NW. Although hard substrates (boulders, bedrock) are clearly identified, the signal can be modified by inclination and biocover. Manually, six RoxAnn zones were identified; for the FCA, only three classes are suggested. The latter classification based on `hard' boundaries would suffice for stakeholder issues, but the former classification based on `soft' boundaries is preferred to meet state-of-the-art scientific objectives.

  13. High-Speed Edge Trimming of CFRP and Online Monitoring of Performance of Router Tools Using Acoustic Emission

    Directory of Open Access Journals (Sweden)

    Rangasamy Prakash

    2016-09-01

    Full Text Available Carbon fiber reinforced polymers (CFRPs have found wide-ranging applications in numerous industrial fields such as aerospace, automotive, and shipping industries due to their excellent mechanical properties that lead to enhanced functional performance. In this paper, an experimental study on edge trimming of CFRP was done with various cutting conditions and different geometry of tools such as helical-, fluted-, and burr-type tools. The investigation involves the measurement of cutting forces for the different machining conditions and its effect on the surface quality of the trimmed edges. The modern cutting tools (router tools or burr tools selected for machining CFRPs, have complex geometries in cutting edges and surfaces, and therefore a traditional method of direct tool wear evaluation is not applicable. An acoustic emission (AE sensing was employed for on-line monitoring of the performance of router tools to determine the relationship between AE signal and length of machining for different kinds of geometry of tools. The investigation showed that the router tool with a flat cutting edge has better performance by generating lower cutting force and better surface finish with no delamination on trimmed edges. The mathematical modeling for the prediction of cutting forces was also done using Artificial Neural Network and Regression Analysis.

  14. Inspection of copper canisters for spent nuclear fuel by means of ultrasound. Ultrasonic imaging, FSW monitoring with acoustic emission

    Energy Technology Data Exchange (ETDEWEB)

    Stepinski, Tadeusz (ed.); Olofsson, Tomas; Wennerstroem, Erik [Uppsala Univ., Dept. of Technical Sciences (Sweden). Signals and Systems

    2006-12-15

    This report contains the research results concerning advanced ultrasound for the inspection of copper canisters for spent nuclear fuel obtained at Signals and Systems, Uppsala University in years 2005/2006. In the first part of the report we propose a concept of monitoring of the friction stir welding (FSW) process by means of acoustic emission (AE) technique. First, we introduce the AE technique and then we present the principle of the system for monitoring the FSW process in cylindrical symmetry specific for the SKB canisters. We propose an omnidirectional circular array of ultrasonic transducers for receiving the AE signals generated by the FSW tool and the releases of the residual stress at canister's circumference. Finally, we review the theory of uniform circular arrays. The second part of the report is concerned with synthetic aperture focusing technique (SAFT) characterized by enhanced spatial resolution. We evaluate three different approaches to perform imaging with less computational cost than that of the extended SAFT (ESAFT) method proposed in our previous reports. First, a sparse version of ESAFT is presented, which solves the reconstruction problem only for a small set of the most probable scatterers in the image. A frequency domain the {omega}-k SAFT algorithm, which relies on the far-field approximation is presented in the second part. Finally, a detailed analysis of the most computationally intense step in the ESAFT and the sparse 2D deconvolution is presented. In the final part of the report we introduce basics of the 3D ultrasonic imaging that has a great potential in the inspection of the FSW welds. We discuss in some detail the three interrelated steps involved in the 3D ultrasonic imaging: data acquisition, 3D reconstruction, and 3D visualization.

  15. Fault Slip Embedded in Creep: Insight into Tectonic Tremors and Slow Slip Events from Acoustic and Optical Monitoring of Fractures

    Science.gov (United States)

    Elkhoury, J. E.; Lengline, O.; Ampuero, J. P.; Schmittbuhl, J.

    2010-12-01

    Observations of temporal and spatial correlations between slow slip earthquakes and tectonic tremor activity suggest a physical relation between them. Early descriptions of mechanisms relating these phenomena simply attributed the relation between seismic and aseismic events to fluid mediated processes. More recent hypotheses suggest that tectonic tremors are bursts of seismic energy due to the rupturing of small asperities within slow slipping regions. Here we present laboratory results of a unique experimental setting aimed at understanding the response to transient loads of a system of small asperities embedded in creep as a model of tectonic tremor activity triggered by slow slip and modulated by tides. We performed mode I crack propagation experiments on glass bead blasted and annealed 2D interfaces of transparent material (Polymethylmethacrylate) where fracture fronts were confined to the 2D weakness plane of the heterogeneous interface. We monitored acoustic emissions (AE) with piezo-electric sensors surrounding the crack front line. We also optically monitored the rupture front line with up to 1000 frames per second. The experimental loading conditions produce quasi-static front propagation at slow average speeds. Image processing reveals de-pinning along the front that we characterize as intermittent opening during slow front propagation. AE locations strongly correlate to the spatiotemporal clustering of the de-penning events along the front. Moreover, this correlation is preserved at the time of imposed transient fluctuations in loading during front propagation. Using the analogy between mode I and modes II and III fractures, our results translate into intermittent slip on faults linked to clustering of seismic activity produced by the breakage of asperities embedded in creeping regions with no need of invoking fluid mediated processes. Thus our experiments help reveal the interplay between aseismic and seismic slip on faults. We also observe qualitative

  16. Acoustics short-term passive monitoring using sonobuoys in the Bering, Chukchi, and Western Beaufort Seas conducted by Alaska Fisheries Scientific Center, National Marine Mammal Laboratory from 2007-08-01 to 2015-09-28 (NCEI Accession 0138863)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Marine Mammal Laboratory (NMML) has conducted passive acoustic monitoring in the Bering, Chukchi, and Western Beaufort Seas to determine spatio-temporal...

  17. Project of a Near-Real-Time Sismo-acoustic Submarine Station for offshore monitoring (NRTSSS)

    Science.gov (United States)

    D'Anna, G.; Calore, D.; Mangano, G.; D'Alessandro, A.; Favali, P.

    2011-12-01

    The INGV seismic network ensures reliable and continuous monitoring of the Italian territory. However, the peculiarity of the Italian peninsula, characterised by an intense offshore geodynamic and seismic activity, requires the extension of the seismic monitoring to the sea. The aim of this project is: - to identify bottleneck is related to the construction, installation and use of underwater seismic station; - to define the most appropriate and low-cost architecture to guarantee the minimum functionality required for a seismic station. In order to obtain reliable seafloor seismic signals integrated to land-based network, the requirements to be fulfill are: - an acceptable coupling with the seabed; - the orientation of the components with respect to the magnetic North and to the verticality; - the correct time stamp of the data; - the data transfer to the land for the integration. Currently, the optimal solution for offshore seismic station is a cable connection to power and real-time data transfer, like the case of Western Ionian Sea cabled observatory, one of the operative node of the EMSO research infrastructure (European Multidisciplinary Seafloor and water column Observatory, http://emso-eu.org). But in the Mediterranean many seismic areas are located a few tens-hundreds of miles from the coast and cabled solutions are not feasible essentially for economic reasons. For this kind of installations EMSO research infrastructure foresees no-cabled solution, that requires a surface buoy deployed in the vicinity seafloor modules.This project plans to develop a surface buoy equipped with autonomous power supply system to power also the seafloor platforms and two-way communication system enabling the data transfer through latest generation of broadband radio communication or satellite link (Fig. 1). All the components of the prototype system are described.

  18. Symbiosis of chemometrics and metabolomics: Past, present, and future

    NARCIS (Netherlands)

    Greef, J. van der; Smilde, A.K.

    2005-01-01

    Metabolomics is a growing area in the field of systems biology. Metabolomics has already a long history and also the connection of metabolomics with chemometrics goes back some time. This review discusses the symbiosis of metabolomics and chemometrics with emphasis on the medical domain, puts the co

  19. Acoustic cavitation-based monitoring of the reversibility and permeability of ultrasound-induced blood-brain barrier opening.

    Science.gov (United States)

    Sun, Tao; Samiotaki, Gesthimani; Wang, Shutao; Acosta, Camilo; Chen, Cherry C; Konofagou, Elisa E

    2015-12-07

    Cavitation events seeded by microbubbles have been previously reported to be associated with MR- or fluorescent-contrast enhancement after focused ultrasound (FUS)-induced blood-brain barrier (BBB) opening. However, it is still unknown whether bubble activity can be correlated with the reversibility (the duration of opening and the likelihood of safe reinstatement) and the permeability of opened BBB, which is critical for the clinical translation of using passive cavitation detection to monitor, predict and control the opening. In this study, the dependence of acoustic cavitation on the BBB opening duration, permeability coefficient and histological damage occurrence were thus investigated. Transcranial pulsed FUS at 1.5 MHz in the presence of systemically circulating microbubbles was applied in the mouse hippocampi (n  =  60). The stable and inertial cavitation activities were monitored during sonication. Contrast-enhanced MRI was performed immediately after sonication and every 24 h up to 6 d thereafter, to assess BBB opening, brain tissue permeability and potential edema. Histological evaluations were used to assess the occurrence of neurovascular damages. It was found that stable cavitation was well correlated with: (1) the duration of the BBB opening (r(2)  =  0.77); (2) the permeability of the opened BBB (r(2)  =  0.82); (3) the likelihood of safe opening (P  cavitation dose was correlated with the resulting BBB permeability (r(2)  =  0.72). Stable cavitation was found to be more reliable than inertial cavitation at assessing the BBB opening within the pressure range used in this study. This study demonstrates that the stable cavitation response during BBB opening holds promise for predicting and controlling the restoration and pharmacokinetics of FUS-opened BBB. The stable cavitation response therefore showed great promise in predicting the BBB opening duration, enabling thus control of opening according to the drug

  20. FINAL TECHNICAL REPORT: Underwater Active Acoustic Monitoring Network For Marine And Hydrokinetic Energy Projects

    Energy Technology Data Exchange (ETDEWEB)

    Stein, Peter J. [Scientific Solutions, Inc, Nashua, NH (United States); Edson, Patrick L. [Scientific Solutions, Inc, Nashua, NH (United States)

    2013-12-20

    This project saw the completion of the design and development of a second generation, high frequency (90-120 kHz) Subsurface-Threat Detection Sonar Network (SDSN). The system was deployed, operated, and tested in Cobscook Bay, Maine near the site the Ocean Renewable Power Company TidGen™ power unit. This effort resulted in a very successful demonstration of the SDSN detection, tracking, localization, and classification capabilities in a high current, MHK environment as measured by results from the detection and tracking trials in Cobscook Bay. The new high frequency node, designed to operate outside the hearing range of a subset of marine mammals, was shown to detect and track objects of marine mammal-like target strength to ranges of approximately 500 meters. This performance range results in the SDSN system tracking objects for a significant duration - on the order of minutes - even in a tidal flow of 5-7 knots, potentially allowing time for MHK system or operator decision-making if marine mammals are present. Having demonstrated detection and tracking of synthetic targets with target strengths similar to some marine mammals, the primary hurdle to eventual automated monitoring is a dataset of actual marine mammal kinematic behavior and modifying the tracking algorithms and parameters which are currently tuned to human diver kinematics and classification.

  1. The Development of Automated Detection Techniques for Passive Acoustic Monitoring as a Tool for Studying Beaked Whale Distribution and Habitat Preferences in the California Current Ecosystem

    Science.gov (United States)

    Yack, Tina M.

    The objectives of this research were to test available automated detection methods for passive acoustic monitoring and integrate the best available method into standard marine mammal monitoring protocols for ship based surveys. The goal of the first chapter was to evaluate the performance and utility of PAMGUARD 1.0 Core software for use in automated detection of marine mammal acoustic signals during towed array surveys. Three different detector configurations of PAMGUARD were compared. These automated detection algorithms were evaluated by comparing them to the results of manual detections made by an experienced bio-acoustician (author TMY). This study provides the first detailed comparisons of PAMGUARD automated detection algorithms to manual detection methods. The results of these comparisons clearly illustrate the utility of automated detection methods for odontocete species. Results of this work showed that the majority of whistles and click events can be reliably detected using PAMGUARD software. The second chapter moves beyond automated detection to examine and test automated classification algorithms for beaked whale species. Beaked whales are notoriously elusive and difficult to study, especially using visual survey methods. The purpose of the second chapter was to test, validate, and compare algorithms for detection of beaked whales in acoustic line-transect survey data. Using data collected at sea from the PAMGUARD classifier developed in Chapter 2 it was possible to measure the clicks from visually verified Baird's beaked whale encounters and use this data to develop classifiers that could discriminate Baird's beaked whales from other beaked whale species in future work. Echolocation clicks from Baird's beaked whales, Berardius bairdii, were recorded during combined visual and acoustic shipboard surveys of cetacean populations in the California Current Ecosystem (CCE) and with autonomous, long-term recorders at four different sites in the Southern

  2. Chemometrics Methods for Specificity, Authenticity and Traceability Analysis of Olive Oils: Principles, Classifications and Applications

    Science.gov (United States)

    Messai, Habib; Farman, Muhammad; Sarraj-Laabidi, Abir; Hammami-Semmar, Asma; Semmar, Nabil

    2016-01-01

    Background. Olive oils (OOs) show high chemical variability due to several factors of genetic, environmental and anthropic types. Genetic and environmental factors are responsible for natural compositions and polymorphic diversification resulting in different varietal patterns and phenotypes. Anthropic factors, however, are at the origin of different blends’ preparation leading to normative, labelled or adulterated commercial products. Control of complex OO samples requires their (i) characterization by specific markers; (ii) authentication by fingerprint patterns; and (iii) monitoring by traceability analysis. Methods. These quality control and management aims require the use of several multivariate statistical tools: specificity highlighting requires ordination methods; authentication checking calls for classification and pattern recognition methods; traceability analysis implies the use of network-based approaches able to separate or extract mixed information and memorized signals from complex matrices. Results. This chapter presents a review of different chemometrics methods applied for the control of OO variability from metabolic and physical-chemical measured characteristics. The different chemometrics methods are illustrated by different study cases on monovarietal and blended OO originated from different countries. Conclusion. Chemometrics tools offer multiple ways for quantitative evaluations and qualitative control of complex chemical variability of OO in relation to several intrinsic and extrinsic factors. PMID:28231172

  3. Acoustic emission and ultrasonic monitoring results from deposition hole DA3545G01 in the Prototype Repository between October 2009 and March 2010

    Energy Technology Data Exchange (ETDEWEB)

    Haycox, Jon; Andrews, Jennifer [ASC, Applied Seismology Consultants, Shrewsbury, Shropshire (United Kingdom)

    2010-09-15

    This report describes results from acoustic emission (AE) and ultrasonic monitoring around a canister deposition hole (DA3545G01) in the Prototype Repository Experiment at SKB's Hard Rock Laboratory (HRL), Sweden. The monitoring aims to examine changes in the rock mass caused by an experimental repository environment, in particular due to thermal stresses induced from canister heating and changes in pore pressures induced from tunnel sealing. Monitoring of this volume has previously been performed during excavation (Pettitt et al. 1999), and during stages of canister heating and tunnel pressurisation (Haycox and Pettitt 2005a, b, 2006a, b, 2009, Zolezzi et al. 2007, 2008, Duckworth et al. 2008, 2009, Haycox and Duckworth 2009). Further information on the previous monitoring periods can be found in Appendix 1. This report covers the period between 1st October 2009 and 31st March 2010 and is the tenth 6-monthly processing and interpretation of the results from the experiment.

  4. Acoustic emission and ultrasonic monitoring results from deposition hole DA3545G01 in the Prototype Repository between April 2009 and September 2009

    Energy Technology Data Exchange (ETDEWEB)

    Haycox, Jon; Pettitt, Will [ASC, Applied Seismology Consultants, Shrewsbury, Shropshire (United Kingdom)

    2009-12-15

    This report describes results from acoustic emission (AE) and ultrasonic monitoring around a canister deposition hole (DA3545G01) in the Prototype Repository Experiment at SKB's Hard Rock Laboratory (HRL), Sweden. The monitoring aims to examine changes in the rock mass caused by an experimental repository environment, in particular due to thermal stresses induced from canister heating and changes in pore pressures induced from tunnel sealing. Monitoring of this volume has previously been performed during excavation (Pettitt et al. 1999), and during stages of canister heating and tunnel pressurisation (Haycox and Pettitt 2005a, b, 2006a, b, Zolezzi et al. 2007, 2008, Duckworth et al. 2008, 2009, Haycox and Duckworth 2009). Further information on the previous monitoring undertaken can be found in Appendix 1. This report covers the period between 1st April 2009 and 30th September 2009 and is the ninth 6-monthly processing and interpretation of the results from the experiment.

  5. Acoustic emission and ultrasonic monitoring results from deposition hole DA3545G01 in the Prototype Repository between October 2008 and March 2009

    Energy Technology Data Exchange (ETDEWEB)

    Haycox, Jon; Duckworth, Damion [ASC, Applied Seismology Consultants, Shrewsbury, Shropshire (United Kingdom)

    2009-06-15

    This report describes results from acoustic emission (AE) and ultrasonic monitoring around a canister deposition hole (DA3545G01) in the Prototype Repository Experiment at SKB's Hard Rock Laboratory (HRL), Sweden. The monitoring aims to examine changes in the rock mass caused by an experimental repository environment, in particular due to thermal stresses induced from canister heating and changes in pore pressures induced from tunnel sealing. Monitoring of this volume has previously been performed during excavation (Pettitt et al. 1999), and during stages of canister heating and tunnel pressurisation (Haycox and Pettitt 2005a, b, 2006a, b, Zolezzi et al. 2007, 2008, Duckworth et al. 2008, 2009). Further information on the previous monitoring undertaken can be found in Appendix 1. This report covers the period between 1st October 2008 and 31st March 2009 and is the eighth 6-monthly processing and interpretation of the results from the experiment.

  6. Acoustic emission and ultrasonic monitoring results from deposition hole DA3545G01 in the Prototype Repository between October 2008 and March 2009

    Energy Technology Data Exchange (ETDEWEB)

    Haycox, Jon; Duckworth, Damion [ASC, Applied Seismology Consultants, Shrewsbury, Shropshire (United Kingdom)

    2009-06-15

    This report describes results from acoustic emission (AE) and ultrasonic monitoring around a canister deposition hole (DA3545G01) in the Prototype Repository Experiment at SKB's Hard Rock Laboratory (HRL), Sweden. The monitoring aims to examine changes in the rock mass caused by an experimental repository environment, in particular due to thermal stresses induced from canister heating and changes in pore pressures induced from tunnel sealing. Monitoring of this volume has previously been performed during excavation (Pettitt et al. 1999), and during stages of canister heating and tunnel pressurisation (Haycox and Pettitt 2005a, b, 2006a, b, Zolezzi et al. 2007, 2008, Duckworth et al. 2008, 2009). Further information on the previous monitoring undertaken can be found in Appendix 1. This report covers the period between 1st October 2008 and 31st March 2009 and is the eighth 6-monthly processing and interpretation of the results from the experiment.

  7. Acoustic emission and ultrasonic monitoring results from deposition hole DA3545G01 in the Prototype Repository between April 2009 and September 2009

    Energy Technology Data Exchange (ETDEWEB)

    Haycox, Jon; Pettitt, Will [ASC, Applied Seismology Consultants, Shrewsbury, Shropshire (United Kingdom)

    2009-12-15

    This report describes results from acoustic emission (AE) and ultrasonic monitoring around a canister deposition hole (DA3545G01) in the Prototype Repository Experiment at SKB's Hard Rock Laboratory (HRL), Sweden. The monitoring aims to examine changes in the rock mass caused by an experimental repository environment, in particular due to thermal stresses induced from canister heating and changes in pore pressures induced from tunnel sealing. Monitoring of this volume has previously been performed during excavation (Pettitt et al. 1999), and during stages of canister heating and tunnel pressurisation (Haycox and Pettitt 2005a, b, 2006a, b, Zolezzi et al. 2007, 2008, Duckworth et al. 2008, 2009, Haycox and Duckworth 2009). Further information on the previous monitoring undertaken can be found in Appendix 1. This report covers the period between 1st April 2009 and 30th September 2009 and is the ninth 6-monthly processing and interpretation of the results from the experiment.

  8. Acoustic emission and ultrasonic monitoring results from deposition hole DA3545G01 in the Prototype Repository between April 2010 and September 2010

    Energy Technology Data Exchange (ETDEWEB)

    Haycox, Jon (ASC Applied Seismology Consultants (United Kingdom))

    2011-05-15

    This report describes results from acoustic emission (AE) and ultrasonic monitoring around a canister deposition hole (DA3545G01) in the Prototype Repository Experiment at SKB's Hard Rock Laboratory (HRL), Sweden. The monitoring aims to examine changes in the rock mass caused by an experimental repository environment, in particular due to thermal stresses induced from canister heating and changes in pore pressures induced from tunnel sealing. Monitoring of this volume has previously been performed during excavation (Pettitt et al. 1999), and during stages of canister heating and tunnel pressurisation (Haycox and Pettitt 2005a, b, 2006a, b, Zolezzi et al. 2007, 2008, Duckworth et al. 2008, 2009, Haycox et al. 2009a, b, 2010). Appendix I contains further information about previous monitoring periods. This report covers the period between 1st April 2010 and 30th September 2010 and is the eleventh 6-monthly processing and interpretation of the results from the experiment

  9. Chemometric applications to assess quality and critical parameters of virgin and extra-virgin olive oil. A review.

    Science.gov (United States)

    Gómez-Caravaca, Ana M; Maggio, Rubén M; Cerretani, Lorenzo

    2016-03-24

    Today virgin and extra-virgin olive oil (VOO and EVOO) are food with a large number of analytical tests planned to ensure its quality and genuineness. Almost all official methods demand high use of reagents and manpower. Because of that, analytical development in this area is continuously evolving. Therefore, this review focuses on analytical methods for EVOO/VOO which use fast and smart approaches based on chemometric techniques in order to reduce time of analysis, reagent consumption, high cost equipment and manpower. Experimental approaches of chemometrics coupled with fast analytical techniques such as UV-Vis spectroscopy, fluorescence, vibrational spectroscopies (NIR, MIR and Raman fluorescence), NMR spectroscopy, and other more complex techniques like chromatography, calorimetry and electrochemical techniques applied to EVOO/VOO production and analysis have been discussed throughout this work. The advantages and drawbacks of this association have also been highlighted. Chemometrics has been evidenced as a powerful tool for the oil industry. In fact, it has been shown how chemometrics can be implemented all along the different steps of EVOO/VOO production: raw material input control, monitoring during process and quality control of final product.

  10. Calibration models for the vinyl acetate concentration in ethylene-vinyl acetate copolymers and its on-line monitoring by near-infrared spectroscopy and chemometrics: use of band shifts associated with variations in the vinyl acetate concentration to improve the models.

    Science.gov (United States)

    Watari, Masahiro; Ozaki, Yukihiro

    2005-07-01

    The present study investigates calibration models for the vinyl acetate (VA) concentration in ethylene-vinyl acetate (EVA) copolymers and its on-line monitoring by near-infrared (NIR) spectroscopy and chemometrics. The key point in the present study is to make use of band shifts associated with concentration changes in the vinyl acetate (VA) for the improvement of the models. NIR spectra of EVA in melt and solid states were measured by a Fourier transform near-infrared (FT-NIR) on-line monitoring system and a FT-NIR laboratory system. Some of the bands in the NIR spectra for both states show significant shifts with the variations in the VA concentration. The peak shifts induced by the VA concentration changes are larger in the solid-state EVA than those in the melt-state EVA. We have developed calibration models for the VA concentration in the solid-state EVA and investigated how to improve the calibration models. The factor analysis of partial least squares (PLS) regression has suggested that the wavenumber shifts caused by the VA concentration changes affect the calibration models for the VA concentration in EVA. From the analysis, it has been proposed that the wavenumbers in the spectrum of one sample in nine EVA samples (VA concentration range: 0-41.1%) are shifted for the improvement of the calibration models, and the effects of the proposed method have been confirmed by using the PLS calibration models for the VA concentration in the solid EVA samples. As the next step, the effects of the wavenumber shift method have been explored for the calibration models for the VA concentration in the melt-state EVA. After that, the discrimination method using the score plots of PLS and the application sequence for the on-line monitoring to use the proposed wavenumber shift method were studied. The simulation results using the discrimination and wavenumber shift methods have shown that those methods are very effective to improve the predicted values of the calibration

  11. Rail-wheel interaction monitoring using Acoustic Emission: A laboratory study of normal rolling signals with natural rail defects

    Science.gov (United States)

    Thakkar, N. A.; Steel, J. A.; Reuben, R. L.

    2010-01-01

    This paper presents a laboratory study on the Acoustic Emission (AE) generated during railway wheel-rail track interaction, with a view to developing methods of in situ rail-wheel interaction monitoring using rail-mounted sensors. It is known that the physical processes of impact and wear generate AE and it was therefore expected that axle loads, speed and traction would influence the AE generated by an interaction and that the characteristics of "normal" interaction would be affected by wheel and/or track defects and/or any misalignment between rail and track. A set of laboratory experiments were carried out on a scaled test rig to characterise the continuous AE generated by a wheel rolling on a rail and, secondarily, to assess the effect on the AE characteristic of the natural defects present on the contact profile of the rail. The natural defects were of a relatively minor nature and their assessment serves as part of the calibration of background AE for experiments with more significant simulated defects. A simplified analytical model, devised for AE waves propagating from a moving source, based on "vehicle" speed and wave damping coefficients, has been developed for the test track and fitted to the measured results. As a wheel rolls towards a sensor and then away from the sensor the measured AE generally rises and falls in a predictable way. The effects of wheel and rail surface features were found to introduce deviations from this "background", and a method to identify the location of surface defects, based on identifying peaks above the background is also demonstrated.

  12. Analysis of the inversion monitoring capabilities of a monostatic acoustic radar in complex terrain. [Tennessee River Valley

    Science.gov (United States)

    Koepf, D.; Frost, W.

    1981-01-01

    A qualitative interpretation of the records from a monostatic acoustic radar is presented. This is achieved with the aid of airplane, helicopter, and rawinsonde temperature soundings. The diurnal structure of a mountain valley circulation pattern is studied with the use of two acoustic radars, one located in the valley and one on the downwind ridge. The monostatic acoustic radar was found to be sufficiently accurate in locating the heights of the inversions and the mixed layer depth to warrant use by industry even in complex terrain.

  13. Development of hydroacoustical techniques for the monitoring and classification of benthic habitats in Puck Bay: Modeling of acoustic waves scattering by seagrass

    Science.gov (United States)

    Raczkowska, A.; Gorska, N.

    2012-12-01

    Puck Bay is an area of high species biodiversity belonging to the Coastal Landscape Park of Baltic Sea Protected Areas (BSPA) and is also included in the list of the World Wide Fund for Nature (WWF) and covered by the protection program "Natura 2000". The underwater meadows of the Puck Bay are important for Europe's natural habitats due to their role in enhancing the productivity of marine ecosystems and providing shelter and optimal feeding conditions for many marine organisms. One of the dominant species comprising the underwater meadows of the Southern Baltic Sea is the seagrass Zostera marina. The spatial extent of underwater seagrass meadows is altered by pollution and eutrophication; therefore, to properly manage the area one must monitor its ecological state. Remote acoustic methods are useful tools for the monitoring of benthic habitats in many marine areas because they are non-invasive and allow researchers to obtain data from a large area in a short period of time. Currently there is a need to apply these methods in the Baltic Sea. Here we present an analysis of the mechanism of scattering of acoustic waves on seagrass in the Southern Baltic Sea based on the numerical modeling of acoustic wave scattering by the biological tissues of plants. The study was conducted by adapting a model developed on the basis of DWBA (Distorted Wave Born Approximation) developed by Stanton and Chu (2005) for fluid-like objects, including the characteristics of the Southern Baltic seagrass. Input data for the model, including the morphometry of seagrass leaves, their angle of inclination and the density plant cover, was obtained through the analysis of biological materials collected in the Puck Bay in the framework of a research project financed by the Polish Government (Development of hydroacoustic methods for studies of underwater meadows of Puck Bay, 6P04E 051 20). On the basis of the developed model, we have analyzed the dependence of the target strength of a single

  14. A case study of real-time monitoring of solid-state phase transformations in acoustically levitated particles using near infrared and Raman spectroscopy

    DEFF Research Database (Denmark)

    Rehder, Sönke; Wu, Jian-Xiong; Laackmann, Julian

    2013-01-01

    . The recrystallisation kinetic parameters were estimated from the recrystallisation profiles. While the empirical recrystallisation rate constant determined by NIR and Raman spectroscopy were comparable, the lag time for recrystallisation was significantly lower with Raman spectroscopy as compared to NIRS......The objective of this study was to monitor the amorphous-to-crystalline solid-state phase transformation kinetics of the model drug ibuprofen with spectroscopic methods during acoustic levitation. Chemical and physical information was obtained by real-time near infrared (NIRS) and Raman...... spectroscopy measurements. The recrystallisation kinetic parameters (overall recrystallisation rate constant ß and the time needed to reach 50% of the equilibrated level t(50)), were determined using a multivariate curve resolution approach. The acoustic levitation device coupled with non-invasive spectroscopy...

  15. Undersea acoustic telemetry across the North Anatolian Fault, Marmara Sea: results from the first 6 months of monitoring of the fault displacement

    Science.gov (United States)

    Royer, J. Y.; Deschamps, A.; Piete, H.; Sakic, P.; Ballu, V.; Apprioual, R.; Kopp, H.; Lange, D.; Ruffine, L.; Géli, L.

    2015-12-01

    Located in the Marmara Sea, the Istanbul-Silivri segment of the North Anatolian Fault (NAF) is known to be a seismic gap since 1766, although, in the last century, the NAF has caused major devastating earthquakes over most of its extent. This fault segment, void of seismicity, may be either creeping aseismically or blocked and accumulating enough strain to produce an earthquake of magnitude 7 or greater. This section of the NAF may thus represent a major seismic and tsunamigenic hazard for the Istanbul megalopolis, located only 40 km away. The objective of the MARSITE project, funded by the European Union and coordinated by the Observatory of the University of Kandilli (KOERI), is to determine the blocking state of the Istanbul-Silivri fault segment. In this context, an array of 10 acoustic transponders has been deployed on either sides of the fault, in the eastern part of the Kumburgaz Basin, to measure the displacements of the fault over a period of 3 to 5 years. The telemetric beacons (4 from the University of Brest and 6 from the GEOMAR Institute in Kiel) form two arrays fitted in one another. The principle of the experiment is to repeatedly measure the distance (ie two-way-travel time of acoustic pings) between pairs of beacons and thus to monitor the deformation of an array of 9 baselines, 500m to 3000m long, of which 5 cross obliquely the assumed fault trace. The French and German arrays are independent but ensure a redundancy of rangings along common baselines. Each acoustic transponder also monitors the temperature, pressure, sound-velocity and attitude (tiltmeters), every one or two hours. Data are stored in each beacon and can be downloaded from the surface using an acoustic modem. We present here the first 6 months of recording by the French array, from November 1st, 2014 to April 25, 2015. All acoustic transponders worked nominally for 6 months and appear to have remained stable on the seafloor. Recorded sea-bottom temperatures provide evidence for

  16. Fatigue crack propagation of aluminum alloy based on acoustic emission monitoring%铝合金疲劳裂纹扩展声发射监测

    Institute of Scientific and Technical Information of China (English)

    朱荣华; 刚铁

    2013-01-01

    The acoustic emission technique was used to monitor the fatigue crack propagation of 7N01 aluminum alloy single-edge notched three-point bend specimens under different stress ratio and peak load. The relationship between the crack growth rate, acoustic emission count rate and stress intensity factor range was established. The results show that most of the a-coustic emission signals were produced in the low stress cyclic loading stage because the acoustic emission activity in low-stress phase was mainly related to the plastic deformation and crack closure in crack tip, and the acoustic emission count exponentially grew with the stress intensity factor. Based on the relationship between the acoustic emission count rate and crack growth rate, the remaining life of fatigue-damaged structures could be predicted.%采用声发射(acoustic emission,AE)技术对7N01铝合金单边缺口三点弯曲试样不同应力比、不同峰值载荷下疲劳裂纹扩展过程中声发射信号进行了监测,建立了裂纹扩展速率、声发射计数(count)与应力强度因子之间的关系.结果表明,大部分的声发射信号主要产生于疲劳循环载荷的低应力阶段,这主要是低应力阶段的声发射活动主要与裂纹尖端的塑性变形和裂纹闭合现象有关,声发射计数与应力强度因子之间呈指数增长的关系.基于所建立的声发射计数率与裂纹扩展速率的关系,可以预测疲劳损伤结构的剩余寿命.

  17. Chemometrics: From classical to genetic algorithms

    Directory of Open Access Journals (Sweden)

    Leardi, Riccardo

    2002-03-01

    Full Text Available In this paper the fundamentals of Chemometrics are presented, by means of a quick overview of the most relevant techniques for data display, classification, modeling and calibration. Two emerging techniques such as Genetic Algorithms and Artificial Neural Networks will also be presented. Goal of the paper is to make people aware of the great superiority of multivariate analysis over the commonly used univariate approach. Mathematical and algorithmical details are not presented, since the paper is mainly focused on the general problems to which Chemometrics can be successfully applied in the field of Food Chemistry.En este artículo se muestran los aspectos fundamentales de la Quimiometria por medio de una revisión rápida de las técnicas más relevantes para mostrar los datos, modelar y calibrar. Se describen dos técnicas emergentes como los algoritmos genéticos y las redes neuronales. El objetivo del articulo es que la comunidad científica tome conciencia de la gran superioridad del análisis multivariante sobre el análisis univariante. No se describen los detalles matemáticos y algorítmicos porque el articulo está dirigido a problemas genéricos en los que la Quimiometría puede ser aplicada con éxito dentro del campo de la Química Analítica.

  18. Chemometric evaluation of brompheniramine-tannate complexes.

    Science.gov (United States)

    Zidan, Ahmed S; Rahman, Ziyaur; Khan, Mansoor A

    2012-04-01

    The objective of the current study was to evaluate the performance of Raman and near-infrared (NIR) techniques combined with chemometrics in characterizing the critical quality attributes of brompheniramine (BP)-tannate complexes. Seven complexes were prepared and evaluated for chemical interactions, solubilities, dissolutions, and spatial distributions by NIR chemical imaging (CI). Principal component analysis (PCA) was applied before either partial least squares regression (PLSR) or principal component regression (PCR) models were developed. Complexation was confirmed by Fourier transform IR analysis to yield complexes of lower drug solubilities and sustained-release characteristics in alkaline media. PCA results showed better discrimination ability by NIR than by Raman spectroscopy. Compared with PCR, the PLSR predictions errors, calculated from the Raman and NIR data with second-derivative pretreatment, showed lesser values of 2.68, 0.37, 1.79, and 5.60 and 0.58, 0.25, 0.93, and 0.58 for complex solubilities in acidic and alkaline media and percentages dissolved after 1 and 20 h, respectively. In addition, good correlation (>0.95) was obtained for predicting the drug concentration using PLSR score images explaining the validity of the NIR-CI model for spatial quantitation of BP within its tannate complexes. In conclusion, the chemometric analysis of NIR and/or Raman spectra represented an innovative approach to determine the tannate complexation variability. Copyright © 2011 Wiley Periodicals, Inc.

  19. Green Sturgeon Acoustic Monitoring

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This database is used to hold tracking data for green sturgeon tagged in Central California. The data collection began in late 2002 and is ongoing.

  20. Field application of a multi-frequency acoustic instrument to monitor sediment for silt erosion study in Pelton turbine in Himalayan region, India

    Science.gov (United States)

    Rai, A. K.; Kumar, A.; Hies, T.; Nguyen, H. H.

    2016-11-01

    High sediment load passing through hydropower components erodes the hydraulic components resulting in loss of efficiency, interruptions in power production and downtime for repair/maintenance, especially in Himalayan regions. The size and concentration of sediment play a major role in silt erosion. The traditional process of collecting samples manually to analyse in laboratory cannot suffice the need of monitoring temporal variation in sediment properties. In this study, a multi-frequency acoustic instrument was applied at desilting chamber to monitor sediment size and concentration entering the turbine. The sediment size and concentration entering the turbine were also measured with manual samples collected twice daily. The samples collected manually were analysed in laboratory with a laser diffraction instrument for size and concentration apart from analysis by drying and filtering methods for concentration. A conductivity probe was used to calculate total dissolved solids, which was further used in results from drying method to calculate suspended solid content of the samples. The acoustic instrument was found to provide sediment concentration values similar to drying and filtering methods. However, no good match was found between mean grain size from the acoustic method with the current status of development and laser diffraction method in the first field application presented here. The future versions of the software and significant sensitivity improvements of the ultrasonic transducers are expected to increase the accuracy in the obtained results. As the instrument is able to capture the concentration and in the future most likely more accurate mean grain size of the suspended sediments, its application for monitoring silt erosion in hydropower plant shall be highly useful.

  1. Chemometrics tools used in analytical chemistry: an overview.

    Science.gov (United States)

    Kumar, Naveen; Bansal, Ankit; Sarma, G S; Rawal, Ravindra K

    2014-06-01

    This article presents various important tools of chemometrics utilized as data evaluation tools generated by various hyphenated analytical techniques including their application since its advent to today. The work has been divided into various sections, which include various multivariate regression methods and multivariate resolution methods. Finally the last section deals with the applicability of chemometric tools in analytical chemistry. The main objective of this article is to review the chemometric methods used in analytical chemistry (qualitative/quantitative), to determine the elution sequence, classify various data sets, assess peak purity and estimate the number of chemical components. These reviewed methods further can be used for treating n-way data obtained by hyphenation of LC with multi-channel detectors. We prefer to provide a detailed view of various important methods developed with their algorithm in favor of employing and understanding them by researchers not very familiar with chemometrics.

  2. Monitoring of the production quality of fibre-reinforced pressure vessels using acoustic emission testing; Ueberwachung der Fertigungsqualitaet von Faserverbund-Druckbehaeltern mittels Schallemissionspruefung

    Energy Technology Data Exchange (ETDEWEB)

    Duffner, Eric; Gregor, Christian; Bohse, Juergen [BAM Bundesanstalt fuer Materialforschung und -pruefung, Berlin (Germany)

    2011-07-01

    The investigation aimed at the validation of a test method for ensuring the production quality of reinforced-fibre pressure vessels in real fabrication conditions. The method is based on characteristics and permissible limiting values derived from acoustic emission curves during the first pressure test. The method had already been tested successfully on reinforced-fibre pressure vessels with metal liners and had been patented. With the current investigations, the possibility of detection fabrication defects in carbon fibre / glass fibre hybrid pressure vessels with polymer liners was evaluated. For this, fibre-reinforced pressure vessels were monitored by acoustic emission measurement during the first hydraulic pressure test; this test is commonly used for quality assurance of this type of pressure vessel, although without acoustic emission testing. Acoustic emission curves were registered for pressure vessels of a serial production, and the mean characteristics and their scatter were determined as reference values. These were compared with the acoustic emission curves of selectively induced fabrication defects. Fabrication defects are defects that may occur in serial production and are difficult or impossible to detect by conventional quality assurance methods. All investigated pressure vessel were then subject to stress until failure (leakage, bursting). This made it possible to verify the real influence of fabrication defects on the burst pressure and/or the fatigue characteristics of the pressure vessels and to assess the validity of acoustic emission testing. [German] Ziel der Untersuchung ist die Validierung einer Pruefmethodik zur Sicherung der Fertigungsqualitaet von Faserverbund - Druckbehaeltern unter realen Fertigungsbedingungen. Das Verfahren basiert auf Merkmalen und zulaessigen Grenzwerten, die aus Schallemissionsverlaeufen bei der Erstdruckpruefung abgeleitet werden [1]. Die Methodik konnte zuvor bereits erfolgreich an Faserverbund - Druckbehaeltern

  3. Chemometrics: A new scenario in herbal drug standardization

    Directory of Open Access Journals (Sweden)

    Ankit Bansal

    2014-08-01

    Full Text Available Chromatography and spectroscopy techniques are the most commonly used methods in standardization of herbal medicines but the herbal system is not easy to analyze because of their complexity of chemical composition. Many cutting-edge analytical technologies have been introduced to evaluate the quality of medicinal plants and significant amount of measurement data has been produced. Chemometric techniques provide a good opportunity for mining more useful chemical information from the original data. Then, the application of chemometrics in the field of medicinal plants is spontaneous and necessary. Comprehensive methods and hyphenated techniques associated with chemometrics used for extracting useful information and supplying various methods of data processing are now more and more widely used in medicinal plants, among which chemometrics resolution methods and principal component analysis (PCA are most commonly used techniques. This review focuses on the recent various important analytical techniques, important chemometrics tools and interpretation of results by PCA, and applications of chemometrics in quality evaluation of medicinal plants in the authenticity, efficacy and consistency.

  4. Continuous Monitoring of Fish Population and Behavior by Instantaneous Continental-Shelf-Scale Imaging with Ocean-Waveguide Acoustics

    Science.gov (United States)

    2008-01-01

    Nero , Mike Jech, Olav Rune Godø, Sunwoong Lee, Purnima Ratilal, and Nicholas Makris, “Ocean Acoustic Waveguide Remote Sensing (OAWRS) of Marine...Srinivasan Jagannathan, Deanelle Symonds, Ioannis Bertsatos, Tianrun Chen, Hector Pena, Ruben Patel, Olav Rune Godø, Redwood W. 6 7 Nero , J

  5. 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

    The research built upon a prior investigation to develop a unified constitutive model for design-­by-­analysis of the intermediate heat exchanger (IHX) for a very high temperature reactor (VHTR) design of next generation nuclear plants (NGNPs). Model development requires a set of failure data from complex mechanical experiments to characterize the material behavior. Therefore uniaxial and multiaxial creep-­fatigue and creep-­ratcheting tests were conducted on the nickel-­base Alloy 617 at 850 and 950°C. The time dependence of material behavior, and the interaction of time dependent behavior (e.g., creep) with ratcheting, which is an increase in the cyclic mean strain under load-­controlled cycling, are major concerns for NGNP design. This research project aimed at characterizing the microstructure evolution mechanisms activated in Alloy 617 by mechanical loading and dwell times at elevated temperature. The acoustic harmonic generation method was researched for microstructural characterization. It is a nonlinear acoustics method with excellent potential for nondestructive evaluation, and even online continuous monitoring once high temperature sensors become available. It is unique because it has the ability to quantitatively characterize microstructural features well before macroscale defects (e.g., cracks) form. The nonlinear acoustics beta parameter was shown to correlate with microstructural evolution using a systematic approach to handle the complexity of multiaxial creep-­fatigue and creep-­ratcheting deformation. Mechanical testing was conducted to provide a full spectrum of data for: thermal aging, tensile creep, uniaxial fatigue, uniaxial creep-­fatigue, uniaxial creep-ratcheting, multiaxial creep-fatigue, and multiaxial creep-­ratcheting. Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), and Optical Microscopy were conducted to correlate the beta parameter with individual microstructure mechanisms. We researched

  6. 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...

  7. Characterization of pharmaceutically relevant materials at the solid state employing chemometrics methods.

    Science.gov (United States)

    Calvo, Natalia L; Maggio, Rubén M; Kaufman, Teodoro S

    2017-06-15

    The understanding of materials and processes is a requirement when it comes to build quality into pharmaceutical products. This can be achieved through the development of rapid, efficient and versatile analytical methods able to perform qualification or quantification tasks along the manufacturing and control process. Process monitoring, capable of providing reliable real-time insights into the processes performance during the manufacturing of solid dosage forms, are the key to improve such understanding. In response to these demands, in recent times multivariate chemometrics algorithms have been increasingly associated to different analytical techniques, mainly vibrational spectroscopies [Raman, mid-infrared (MIR), near-infrared (NIR)], but also ultraviolet-visible (UV-vis) spectroscopy, X-ray powder diffraction and other methodologies. The resulting associations have been applied to the characterization and evaluation of different aspects of pharmaceutical materials at the solid state. This review examines the different scenarios where these methodological marriages have been successful. The list of analytical problems and regulatory demands solved by chemometrics analysis of solid-state multivariate data covers the whole manufacturing and control processes of both, active pharmaceutical ingredients in bulk and in their drug products. Hence, these combinations have found use in monitoring the crystallization processes of drugs and supramolecular drug associations (co-crystals, co-amorphous and salts), to access the correct crystal morphology, particle size, solubility and dissolution properties. In addition, they have been applied to identify and quantitate specific compounds, mainly active pharmaceutical ingredients in complex solid state mixtures. This included drug stability against different stimuli, solid-state transformations, or detection of adulterated or fraudulent medicines. The use of chemometrics-assisted analytical methods as part of the modern

  8. Identification and spatial patterns of coastal water pollution sources based on GIS and chemometric approach

    Institute of Scientific and Technical Information of China (English)

    ZHOU Feng; GUO Huai-cheng; LIU Yong; HAO Ze-jia

    2007-01-01

    Comprehensive and joint applications of GIS and chemometric approach were applied in identification and spatial patterns of coastal water pollution sources with a large data set (5 years (2000-2004), 17 parameters) obtained through coastal water monitoring of Southern Water Control Zone in Hong Kong. According to cluster analysis the pollution degree was significantly different between September-next May (the 1st period) and June-August (the 2nd period). Based on these results, four potential pollution sources, such as organic/eutrophication pollution, natural pollution, mineral/anthropic pollution and fecal pollution were identified by factor analysis/principal component analysis. Then the factor scores of each monitoring site were analyzed using inverse distance weighting method, and the results indicated degree of the influence by various potential pollution sources differed among the monitoring sites. This study indicated that hybrid approach was useful and effective for identification of coastal water pollution source and spatial pattern.

  9. Real-time monitoring of focused ultrasound blood-brain barrier opening via subharmonic acoustic emission detection: implementation of confocal dual-frequency piezoelectric transducers

    Science.gov (United States)

    Tsai, Chih-Hung; Zhang, Jia-Wei; Liao, Yi-Yi; Liu, Hao-Li

    2016-04-01

    Burst-tone focused ultrasound exposure in the presence of microbubbles has been demonstrated to be effective at inducing temporal and local opening of the blood-brain barrier (BBB), which promises significant clinical potential to deliver therapeutic molecules into the central nervous system (CNS). Traditional contrast-enhanced imaging confirmation after focused ultrasound (FUS) exposure serves as a post-operative indicator of the effectiveness of FUS-BBB opening, however, an indicator that can concurrently report the BBB status and BBB-opening effectiveness is required to provide effective feedback to implement this treatment clinically. In this study, we demonstrate the use of subharmonic acoustic emission detection with implementation on a confocal dual-frequency piezoelectric ceramic structure to perform real-time monitoring of FUS-BBB opening. A confocal dual-frequency (0.55 MHz/1.1 MHz) focused ultrasound transducer was designed. The 1.1 MHz spherically-curved ceramic was employed to deliver FUS exposure to induce BBB-opening, whereas the outer-ring 0.55 MHz ceramic was employed to detect the subharmonic acoustic emissions originating from the target position. In stage-1 experiments, we employed spectral analysis and performed an energy spectrum density (ESD) calculation. An optimized 0.55 MHz ESD level change was shown to effectively discriminate the occurrence of BBB-opening. Wideband acoustic emissions received from 0.55 MHz ceramics were also analyzed to evaluate its correlations with erythrocyte extravasations. In stage-2 real-time monitoring experiments, we applied the predetermined ESD change as a detection threshold in PC-controlled algorithm to predict the FUS exposure intra-operatively. In stage-1 experiment, we showed that subharmonic ESD presents distinguishable dynamics between intact BBB and opened BBB, and therefore a threshold ESD change level (5.5 dB) can be identified for BBB-opening prediction. Using this ESD change threshold detection as a

  10. Real-time monitoring of focused ultrasound blood-brain barrier opening via subharmonic acoustic emission detection: implementation of confocal dual-frequency piezoelectric transducers.

    Science.gov (United States)

    Tsai, Chih-Hung; Zhang, Jia-Wei; Liao, Yi-Yi; Liu, Hao-Li

    2016-04-07

    Burst-tone focused ultrasound exposure in the presence of microbubbles has been demonstrated to be effective at inducing temporal and local opening of the blood-brain barrier (BBB), which promises significant clinical potential to deliver therapeutic molecules into the central nervous system (CNS). Traditional contrast-enhanced imaging confirmation after focused ultrasound (FUS) exposure serves as a post-operative indicator of the effectiveness of FUS-BBB opening, however, an indicator that can concurrently report the BBB status and BBB-opening effectiveness is required to provide effective feedback to implement this treatment clinically. In this study, we demonstrate the use of subharmonic acoustic emission detection with implementation on a confocal dual-frequency piezoelectric ceramic structure to perform real-time monitoring of FUS-BBB opening. A confocal dual-frequency (0.55 MHz/1.1 MHz) focused ultrasound transducer was designed. The 1.1 MHz spherically-curved ceramic was employed to deliver FUS exposure to induce BBB-opening, whereas the outer-ring 0.55 MHz ceramic was employed to detect the subharmonic acoustic emissions originating from the target position. In stage-1 experiments, we employed spectral analysis and performed an energy spectrum density (ESD) calculation. An optimized 0.55 MHz ESD level change was shown to effectively discriminate the occurrence of BBB-opening. Wideband acoustic emissions received from 0.55 MHz ceramics were also analyzed to evaluate its correlations with erythrocyte extravasations. In stage-2 real-time monitoring experiments, we applied the predetermined ESD change as a detection threshold in PC-controlled algorithm to predict the FUS exposure intra-operatively. In stage-1 experiment, we showed that subharmonic ESD presents distinguishable dynamics between intact BBB and opened BBB, and therefore a threshold ESD change level (5.5 dB) can be identified for BBB-opening prediction. Using this ESD change threshold detection as a

  11. Activated sludge characterization through microscopy: A review on quantitative image analysis and chemometric techniques

    Energy Technology Data Exchange (ETDEWEB)

    Mesquita, Daniela P. [IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga (Portugal); Amaral, A. Luís [IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga (Portugal); Instituto Politécnico de Coimbra, ISEC, DEQB, Rua Pedro Nunes, Quinta da Nora, 3030-199 Coimbra (Portugal); Ferreira, Eugénio C., E-mail: ecferreira@deb.uminho.pt [IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga (Portugal)

    2013-11-13

    Graphical abstract: -- Highlights: •Quantitative image analysis shows potential to monitor activated sludge systems. •Staining techniques increase the potential for detection of operational problems. •Chemometrics combined with quantitative image analysis is valuable for process monitoring. -- Abstract: In wastewater treatment processes, and particularly in activated sludge systems, efficiency is quite dependent on the operating conditions, and a number of problems may arise due to sludge structure and proliferation of specific microorganisms. In fact, bacterial communities and protozoa identification by microscopy inspection is already routinely employed in a considerable number of cases. Furthermore, quantitative image analysis techniques have been increasingly used throughout the years for the assessment of aggregates and filamentous bacteria properties. These procedures are able to provide an ever growing amount of data for wastewater treatment processes in which chemometric techniques can be a valuable tool. However, the determination of microbial communities’ properties remains a current challenge in spite of the great diversity of microscopy techniques applied. In this review, activated sludge characterization is discussed highlighting the aggregates structure and filamentous bacteria determination by image analysis on bright-field, phase-contrast, and fluorescence microscopy. An in-depth analysis is performed to summarize the many new findings that have been obtained, and future developments for these biological processes are further discussed.

  12. 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.

  13. Intensive sound speed monitoring in ocean and its impact on the GPS/acoustic seafloor geodetic measurement

    Science.gov (United States)

    Kido, Motoyuki

    2016-04-01

    GPS/acoustic (GPS/A) technique, based on GPS positioning and acoustic ranging, is now getting a popular tool to measure seafloor crustal movement. Several groups in the world have been intensively conducted campaign surveys in the region of scientifically interest. As the technology of measurement has been matured and plenty of data are accumulated, researchers are now aware of the limit of its precision mainly due to unexpected undulation of sound speed in ocean, which significantly degrades acoustic ranging. If sound speed structure keeps its figure during survey period, e.g., more than a couple of hours, it can be estimated by a moving survey to get sufficient paths from various directions to illustrate the structure. However the sound speed structure often varies quickly with in a hour due to internal gravitational wave excited by interaction of tidal current and seafloor topography. In this case one cannot separate temporal and spatial variations. We revisited our numerous sound speed profile data derived from numbers of XBT measurements, which were concurrently carried out with GPS/A survey along the Nankai Trough and Japan Trench. Among the measurements, we found notably short-period variation in sound speed profile through intensive XBT survey repeatedly cast every 6 minutes for one hour, which also appeared in residuals in traveltime of acoustic ranging. The same feature is also found in more moderate rate for semidiurnal undulation, in which vertical oscillation of the middle of the profile can be clearly seen rather than variation of absolute sound speed. This also reflects traveltime residuals in the GPS/A measurement. These typical frequencies represent dominant wavelengths of spatial sound speed variation. In the latter, local horizontal variation can be negligible in the vicinity of a point survey area and the traditional analysis can be applicable that assumes time-varying stratified sound speed structure. In the former case, on the contrary, local

  14. Online-monitoring of MO-surge arresters with passive surface acoustic wave radio sensors; Online-Temperaturmessung an MO-Ueberspannungsableitern mit funkabfragbaren Oberflaechenwellensensoren

    Energy Technology Data Exchange (ETDEWEB)

    Hinrichsen, V. [Siemens AG, Berlin (Germany). Bereich Energieuebertragung und -verteilung; Scholl, G. [Siemens AG, Muenchen (Germany). Fachzentrum Oberflaechenwellentechnik und Funksensorik

    1998-08-24

    Today no practicable and economical solutions are available for an overall online-monitoring of high-voltage metal oxide surge arresters, which should comprise a surge counter function, an energy monitor and the monitoring of electrical aging if required. A permanent measurement of the arrester temperature on high potential, which basically could provide all these functions, has not yet been realized due to the related technical problems. However, newly developed high-frequency temperature measuring systems based on wireless passive surface acoustic wave temperature sensors are now offering this possibility for the first time. They are actually being field-tested in a 420-kV-arrester and have shown a good performance so far. (orig.) [Deutsch] Zu einem geschlossenen Online-Monitoringkonzept von Hochspannungs-Metalloxid-Ableitern, das eine Ansprechzaehlerfunktion, einen Energiemonitor and gegebenenfalls eine Ueberwachung elektrischer Kennlinienalterung enthalten sollte, fehlen bis heute geeignete, wirtschaftlich vertretbare Loesungen. Eine dauernde Messung der Ableitertemperatur auf Hochspannungspotential, mit der an sich alle genannten Funktionen einfach realisiert werden koennten, scheiterte bisher an der technischen Umsetzbarkeit. Neuentwickelte funkabfragbare Oberflaechenwellen-Temperatursensoren eroeffenen nun erstmalig diese Moeglichkeit. Eingebaut in einem 420-kV-Ableiter, befinden sie sich zur Zeit in einem Feldversuch in praktischer Erprobung und erfuellen dort alle in sie gesetzten Erwartungen. (orig.)

  15. Intraoperative facial motor evoked potentials monitoring with transcranial electrical stimulation for preservation of facial nerve function in patients with large acoustic neuroma

    Institute of Scientific and Technical Information of China (English)

    LIU Bai-yun; TIAN Yong-ji; LIU Wen; LIU Shu-ling; QIAO Hui; ZHANG Jun-ting; JIA Gui-jun

    2007-01-01

    Background Although various monitoring techniques have been used routinely in the treatment of the lesions in the skull base, iatrogenic facial paresis or paralysis remains a significant clinical problem. The aim of this study was to investigate the effect of intraoperative facial motor evoked potentials monitoring with transcranial electrical stimulation on preservation of facial nerve function.Method From January to November 2005, 19 patients with large acoustic neuroma were treated using intraoperative facial motor evoked potentials monitoring with transcranial electrical stimulation (TCEMEP) for preservation of facial nerve function. The relationship between the decrease of MEP amplitude after tumor removal and the postoperative function of the facial nerve was analyzed.Results MEP amplitude decreased more than 75% in 11 patients, of which 6 presented significant facial paralysis (H-B grade 3), and 5 had mild facial paralysis (H-B grade 2). In the other 8 patients, whose MEP amplitude decreased less than 75%, 1 experienced significant facial paralysis, 5 had mild facial paralysis, and 2 were normal.Conclusions Intraoperative TCEMEP can be used to predict postoperative function of the facial nerve. The decreased MEP amplitude above 75 % is an alarm point for possible severe facial paralysis.

  16. Signal frequency distribution and natural-time analyses from acoustic emission monitoring of an arched structure in the Castle of Racconigi

    Science.gov (United States)

    Niccolini, Gianni; Manuello, Amedeo; Marchis, Elena; Carpinteri, Alberto

    2017-07-01

    The stability of an arch as a structural element in the thermal bath of King Charles Albert (Carlo Alberto) in the Royal Castle of Racconigi (on the UNESCO World Heritage List since 1997) was assessed by the acoustic emission (AE) monitoring technique with application of classical inversion methods to recorded AE data. First, damage source location by means of triangulation techniques and signal frequency analysis were carried out. Then, the recently introduced method of natural-time analysis was preliminarily applied to the AE time series in order to reveal a possible entrance point to a critical state of the monitored structural element. Finally, possible influence of the local seismic and microseismic activity on the stability of the monitored structure was investigated. The criterion for selecting relevant earthquakes was based on the estimation of the size of earthquake preparation zones. The presented results suggest the use of the AE technique as a tool for detecting both ongoing structural damage processes and microseismic activity during preparation stages of seismic events.

  17. Chemometrics applications in biotechnology processes: predicting column integrity and impurity clearance during reuse of chromatography resin.

    Science.gov (United States)

    Rathore, Anurag S; Mittal, Shachi; Lute, Scott; Brorson, Kurt

    2012-01-01

    Separation media, in particular chromatography media, is typically one of the major contributors to the cost of goods for production of a biotechnology therapeutic. To be cost-effective, it is industry practice that media be reused over several cycles before being discarded. The traditional approach for estimating the number of cycles a particular media can be reused for involves performing laboratory scale experiments that monitor column performance and carryover. This dataset is then used to predict the number of cycles the media can be used at manufacturing scale (concurrent validation). Although, well accepted and widely practiced, there are challenges associated with extrapolating the laboratory scale data to manufacturing scale due to differences that may exist across scales. Factors that may be different include: level of impurities in the feed material, lot to lot variability in feedstock impurities, design of the column housing unit with respect to cleanability, and homogeneity of the column packing. In view of these challenges, there is a need for approaches that may be able to predict column underperformance at the manufacturing scale over the product lifecycle. In case such an underperformance is predicted, the operators can unpack and repack the chromatography column beforehand and thus avoid batch loss. Chemometrics offers one such solution. In this article, we present an application of chemometrics toward the analysis of a set of chromatography profiles with the intention of predicting the various events of column underperformance including the backpressure buildup and inefficient deoxyribonucleic acid clearance.

  18. Simultaneous Determination of Amiloride and Hydrochlorothiazide in a Compound Tablet by Diffuse Reflectance Spectroscopy and Chemometrics

    Science.gov (United States)

    Tang, J.; Li, X.; Feng, Y.; Liang, B.

    2016-09-01

    This paper studies the simultaneous determination of amiloride hydrochloride (AMH) and hydrochlorothiazide (HCTZ) in amiloride hydrochloride tablets by ultraviolet-visible-shortwave near-infrared diffuse reflectance spectroscopy (UV-Vis-swNIR DRS) and chemometrics. Quantitative models for the two components were established by partial least squares (PLS) and support vector regression (SVR), respectively. For the PLS models of AMH and HCTZ, the determination coefficient R2 of the calibration set was 0.9503 and 0.9538, and the coefficient R2 of the prediction set was 0.8983 and 0.9260, respectively. The root mean square error of the calibration set (RMSEC) was 0.8 mg and 8.1 mg, while the root mean square error of the prediction set (RMSEP) was 1.0 mg and 8.7 mg, respectively. For the SVR models of AMH and HCTZ, the R2 of the calibration set was 0.9668 and 0.9609; the R2 of the prediction set was 0.9145 and 0.9446, respectively. The RMSEC was 0.7 and 7.5 mg, and the RMSEP was 0.9 and 8.9 mg, respectively. The results show that SVR modeling has a satisfactory prediction effect. The proposed method based on UV-vis-swNIR and chemometrics is efficient, nondestructive, and expected to be used for online quality monitoring in the production of drugs.

  19. Acoustic Imaging of Combustion Noise

    Science.gov (United States)

    Ramohalli, K. N.; Seshan, P. K.

    1984-01-01

    Elliposidal acoustic mirror used to measure sound emitted at discrete points in burning turbulent jets. Mirror deemphasizes sources close to target source and excludes sources far from target. At acoustic frequency of 20 kHz, mirror resolves sound from region 1.25 cm wide. Currently used by NASA for research on jet flames. Produces clearly identifiable and measurable variation of acoustic spectral intensities along length of flame. Utilized in variety of monitoring or control systems involving flames or other reacting flows.

  20. Non-Destructive Evaluation for Corrosion Monitoring in Concrete: A Review and Capability of Acoustic Emission Technique

    Directory of Open Access Journals (Sweden)

    Ahmad Zaki

    2015-08-01

    Full Text Available Corrosion of reinforced concrete (RC structures has been one of the major causes of structural failure. Early detection of the corrosion process could help limit the location and the extent of necessary repairs or replacement, as well as reduce the cost associated with rehabilitation work. Non-destructive testing (NDT methods have been found to be useful for in-situ evaluation of steel corrosion in RC, where the effect of steel corrosion and the integrity of the concrete structure can be assessed effectively. A complementary study of NDT methods for the investigation of corrosion is presented here. In this paper, acoustic emission (AE effectively detects the corrosion of concrete structures at an early stage. The capability of the AE technique to detect corrosion occurring in real-time makes it a strong candidate for serving as an efficient NDT method, giving it an advantage over other NDT methods.

  1. Non-Destructive Evaluation for Corrosion Monitoring in Concrete: A Review and Capability of Acoustic Emission Technique

    Science.gov (United States)

    Zaki, Ahmad; Chai, Hwa Kian; Aggelis, Dimitrios G.; Alver, Ninel

    2015-01-01

    Corrosion of reinforced concrete (RC) structures has been one of the major causes of structural failure. Early detection of the corrosion process could help limit the location and the extent of necessary repairs or replacement, as well as reduce the cost associated with rehabilitation work. Non-destructive testing (NDT) methods have been found to be useful for in-situ evaluation of steel corrosion in RC, where the effect of steel corrosion and the integrity of the concrete structure can be assessed effectively. A complementary study of NDT methods for the investigation of corrosion is presented here. In this paper, acoustic emission (AE) effectively detects the corrosion of concrete structures at an early stage. The capability of the AE technique to detect corrosion occurring in real-time makes it a strong candidate for serving as an efficient NDT method, giving it an advantage over other NDT methods. PMID:26251904

  2. Bat Species Occurrence and Long-Term Bat Population Monitoring on Refuges Using Acoustical Detection - 2012-2015 Summary

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Long-term trend monitoring efforts for bats on National Wildlife Refuges have been prompted by a paucity of significant population information and precipitous...

  3. LEGACY - EOP Acoustic tagging and monitorings of cultured and wild juvenile crimson jobfish (Pristipomoides filamentosus) in a nursery habitat

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Raw data from Vemco receivers that monitored the Kaneohe, Oahu nursery grounds while tagged juvenile snapper were released in 2006 (cultured) and 2007 (wild). Also...

  4. 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....

  5. Repetitive Immunoassay with a Surface Acoustic Wave Device and a Highly Stable Protein Monolayer for On-Site Monitoring of Airborne Dust Mite Allergens.

    Science.gov (United States)

    Toma, Koji; Miki, Daisuke; Kishikawa, Chisato; Yoshimura, Naoyuki; Miyajima, Kumiko; Arakawa, Takahiro; Yatsuda, Hiromi; Mitsubayashi, Kohji

    2015-10-20

    This work describes a sensor to be incorporated into the on-site monitoring system of airborne house dust mite (HDM) allergens. A surface acoustic wave (SAW) device was combined with self-assembled monolayers of a highly stable antibody capture protein on the SAW surface that have high resistance to pH change. A sandwich assay was used to measure a HDM allergen, Der f 1 derived from Dermatophagoides farinae. Capture antibodies were cross-linked to a protein G based capture layer (ORLA85) on the sensor surface, thereby only Der f 1 and detection antibodies were regenerated by changing pH, resulting in fast repetition of the measurement. The sensor was characterized through 10 repetitive measurements of Der f 1, which demonstrated high reproducibility of the sensor with the coefficient of variation of 5.6%. The limit of detection (LOD) of the sensor was 6.1 ng·mL(-1), encompassing the standard (20 ng·mL(-1)) set by the World Health Organization. Negligible sensor outputs were observed for five different major allergens including other HDM allergens which tend to have cross-reactivity to Der f 1 and their mixtures with Der f 1. Finally, the sensor lifetime was evaluated by conducting three measurements per day, and the sensor output did not substantially change for 4 days. These characteristics make the SAW immunosensor a promising candidate for incorporation into on-site allergen monitoring systems.

  6. Real-time monitoring of methanol concentration using a shear horizontal surface acoustic wave sensor for direct methanol fuel cell without reference liquid measurement

    Science.gov (United States)

    Tada, Kyosuke; Nozawa, Takuya; Kondoh, Jun

    2017-07-01

    In recent years, there has been an increasing demand for sensors that continuously measure liquid concentrations and detect abnormalities in liquid environments. In this study, a shear horizontal surface acoustic wave (SH-SAW) sensor is applied for the continuous monitoring of liquid concentrations. As the SH-SAW sensor functions using the relative measurement method, it normally needs a reference at each measurement. However, if the sensor is installed in a liquid flow cell, it is difficult to measure a reference liquid. Therefore, it is important to establish an estimation method for liquid concentrations using the SH-SAW sensor without requiring a reference measurement. In this study, the SH-SAW sensor is installed in a direct methanol fuel cell to monitor the methanol concentration. The estimated concentration is compared with a conventional density meter. Moreover, the effect of formic acid is examined. When the fuel temperature is higher than 70 °C, it is necessary to consider the influence of liquid conductivity. Here, an estimation method for these cases is also proposed.

  7. Acoustic mapping velocimetry

    Science.gov (United States)

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

    2016-05-01

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

  8. Acoustic telemetry

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — To determine movements of green turtles in the nearshore foraging areas, we deployed acoustic tags and determined their movements through active and passive acoustic...

  9. Chemometric Optimization Studies in Catalysis Employing High-Throughput Experimentation

    NARCIS (Netherlands)

    Pereira, S.R.M.

    2008-01-01

    The main topic of this thesis is the investigation of the synergies between High-Throughput Experimentation (HTE) and Chemometric Optimization methodologies in Catalysis research and of the use of such methodologies to maximize the advantages of using HTE methods. Several case studies were analysed

  10. Chemometrics in multispectral imaging for quality inspection of postharvest products

    NARCIS (Netherlands)

    Noordam, Jan Corstiaan

    2005-01-01

    This thesis describes different novel chemometric techniques applied to multispectral images for quality inspection on agricultural food products. These images do not only have a huge number of spectral bands which makes training set selection a challenging task, they also contain classes with small

  11. Principal Component Analysis: Most Favourite Tool in Chemometrics

    Indian Academy of Sciences (India)

    Keshav Kumar

    2017-08-01

    Principal component analysis (PCA) is the most commonlyused chemometric technique. It is an unsupervised patternrecognition technique. PCA has found applications in chemistry,biology, medicine and economics. The present work attemptsto understand how PCA work and how can we interpretits results.

  12. Acoustic detection and long-term monitoring of pygmy blue whales over the continental slope in southwest Australia.

    Science.gov (United States)

    Gavrilova, Alexander N; McCauley, Robert D

    2013-09-01

    A 9-yr dataset of continuous sea noise recording made at the Cape Leeuwin station of the Comprehensive Nuclear-Test-Ban Treaty hydroacoustic network in 2002-2010 was processed to detect calls from pygmy blue whales and to analyze diurnal, seasonal, and interannual variations in their vocal activity. Because the conventional spectrogram correlation method for recognizing whale calls in sea noise resulted in a too high false detection rate, alternative algorithms were tested and the most robust one applied to the multi-year dataset. The detection method was based on multivariate classification using two spectrogram features of transients in sea noise and Fisher's linear discriminant, which provided a misclassification rate of approximately 1% for missed and false detections at moderate sensitivity settings. An analysis of the detection results revealed a consistent seasonal pattern in the whale presence and considerable interannual changes with a steady increase in the number of calls detected in 2002-2006. An apparent diurnal pattern of whales' vocal activity was also observed. The acoustic detection range for pygmy blue whales was estimated to vary from about 50 km to nearly 200 km from the Cape Leeuwin station, depending on the ambient noise level, source level, and azimuth to a vocalizing whale.

  13. Acoustic habitat and shellfish mapping and monitoring in shallow coastal water - Sidescan sonar experiences in The Netherlands

    NARCIS (Netherlands)

    Overmeeren, R. van; Craeymeersch, J.; Dalfsen, J. van; Fey, F.; Heteren, S. van; Meesters, E.

    2009-01-01

    Sidescan sonar has been applied in a number of shallow water environments along the Dutch coast to map and monitor shellfish and seabed habitats. The littoral setting of these surveys may hamper data acquisition flying the towfish in zones of turbulence and waves, but also offers valuable opportunit

  14. An evaluation of acoustic seabed classification techniques for marine biotope monitoring over broad-scales (>1 km 2) and meso-scales (10 m 2-1 km 2)

    Science.gov (United States)

    van Rein, H.; Brown, C. J.; Quinn, R.; Breen, J.; Schoeman, D.

    2011-07-01

    Acoustic seabed classification is a useful tool for monitoring marine benthic habitats over broad-scales (>1 km 2) and meso-scales (10 m 2-1 km 2). Its utility in this context was evaluated using two approaches: by describing natural changes in the temporal distribution of marine biotopes across the broad-scale (4 km 2), and by attempting to detect specific experimentally-induced changes to kelp-dominated biotopes across the meso-scale (100 m 2). For the first approach, acoustic backscatter mosaics were constructed using sidescan sonar and multibeam echosounder data collected from Church Bay (Rathlin Island, Northern Ireland) in 1999, 2008 and 2009. The mosaics were manually segmented into acoustic facies, which were ground-truthed using a drop-video camera. Biotopes were classified from the video by multivariate exploratory analysis and cross-tabulated with the acoustic facies, showing a positive correlation. These results were integrated with bathymetric data to map the distribution of seven unique biotopes in Church Bay. Kappa analysis showed the biotope distribution was highly similar between the biotope maps, possibly due to the stability of bedforms shaped by the tidal regime around Rathlin Island. The greatest biotope change in this approach was represented by seasonal and annual changes in the growth of the seagrass, Zostera marina. In the second approach, sidescan sonar data were collected before and after the removal of 100 m 2 of kelp from three sites. Comparison of the data revealed no differences between the high-resolution backscatter imagery. It is concluded that acoustic seabed classification can be used to monitor change over broad- and meso-scales but not necessarily for all biotopes; its success depends on the type of acoustic system employed and the biological characteristics of the target biotope.

  15. Discriminant analyzing system for wood wastes using a visible-near-infrared chemometric imaging technique.

    Science.gov (United States)

    Kobori, Hikaru; Yonenobu, Hitoshi; Noma, Junichi; Tsuchikawa, Satoru

    2008-08-01

    A new optical system was developed and applied to automated separation of wood wastes, using a combined technique of visible-near-infrared (Vis-NIR) imaging analysis and chemometrics. Three kinds of typical wood wastes were used, i.e., non-treated, impregnated, and plastic-film overlaid wood. The classification model based on soft independent modeling of class analogy (SIMCA) was examined using the difference luminance brightness of a sample. Our newly developed system showed a good/promising performance in separation of wood wastes, with an average rate of correct separation of 89%. Hence, it is concluded that the system is efficiently feasible for online monitoring and separation of wood wastes in recycling mills.

  16. Preoperative characteristics of auditory brainstem response in acoustic neuroma with useful hearing: importance as a preliminary investigation for intraoperative monitoring.

    Science.gov (United States)

    Aihara, Noritaka; Murakami, Shingo; Takahashi, Mariko; Yamada, Kazuo

    2014-01-01

    We classified the results of preoperative auditory brainstem response (ABR) in 121 patients with useful hearing and considered the utility of preoperative ABR as a preliminary assessment for intraoperative monitoring. Wave V was confirmed in 113 patients and was not confirmed in 8 patients. Intraoperative ABR could not detect wave V in these 8 patients. The 8 patients without wave V were classified into two groups (flat and wave I only), and the reason why wave V could not be detected may have differed between the groups. Because high-frequency hearing was impaired in flat patients, an alternative to click stimulation may be more effective. Monitoring cochlear nerve action potential (CNAP) may be useful because CNAP could be detected in 4 of 5 wave I only patients. Useful hearing was preserved after surgery in 1 patient in the flat group and 2 patients in wave I only group. Among patients with wave V, the mean interaural latency difference of wave V was 0.88 ms in Class A (n = 57) and 1.26 ms in Class B (n = 56). Because the latency of wave V is already prolonged before surgery, to estimate delay in wave V latency during surgery probably underestimates cochlear nerve damage. Recording intraoperative ABR is indispensable to avoid cochlear nerve damage and to provide information for surgical decisions. Confirming the condition of ABR before surgery helps to solve certain problems, such as choosing to monitor the interaural latency difference of wave V, CNAP, or alternative sound-evoked ABR.

  17. 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.

  18. Acoustic cloaking and transformation acoustics

    Energy Technology Data Exchange (ETDEWEB)

    Chen Huanyang [School of Physical Science and Technology, Soochow University, Suzhou, Jiangsu 215006 (China); Chan, C T, E-mail: kenyon@ust.h, E-mail: phchan@ust.h [Department of Physics and the William Mong Institute of NanoScience and Technology, The Hong Kong University of Science and Technology, Clear Water Bay (Hong Kong)

    2010-03-24

    In this review, we give a brief introduction to the application of the new technique of transformation acoustics, which draws on a correspondence between coordinate transformation and material properties. The technique is formulated for both acoustic waves and linear liquid surface waves. Some interesting conceptual devices can be designed for manipulating acoustic waves. For example, we can design acoustic cloaks that make an object invisible to acoustic waves, and the cloak can either encompass or lie outside the object to be concealed. Transformation acoustics, as an analog of transformation optics, can go beyond invisibility cloaking. As an illustration for manipulating linear liquid surface waves, we show that a liquid wave rotator can be designed and fabricated to rotate the wave front. The acoustic transformation media require acoustic materials which are anisotropic and inhomogeneous. Such materials are difficult to find in nature. However, composite materials with embedded sub-wavelength resonators can in principle be made and such 'acoustic metamaterials' can exhibit nearly arbitrary values of effective density and modulus tensors to satisfy the demanding material requirements in transformation acoustics. We introduce resonant sonic materials and Helmholtz resonators as examples of acoustic metamaterials that exhibit resonant behaviour in effective density and effective modulus. (topical review)

  19. Food intake monitoring: an acoustical approach to automated food intake activity detection and classification of consumed food.

    Science.gov (United States)

    Päßler, Sebastian; Wolff, Matthias; Fischer, Wolf-Joachim

    2012-06-01

    Obesity and nutrition-related diseases are currently growing challenges for medicine. A precise and timesaving method for food intake monitoring is needed. For this purpose, an approach based on the classification of sounds produced during food intake is presented. Sounds are recorded non-invasively by miniature microphones in the outer ear canal. A database of 51 participants eating seven types of food and consuming one drink has been developed for algorithm development and model training. The database is labeled manually using a protocol with introductions for annotation. The annotation procedure is evaluated using Cohen's kappa coefficient. The food intake activity is detected by the comparison of the signal energy of in-ear sounds to environmental sounds recorded by a reference microphone. Hidden Markov models are used for the recognition of single chew or swallowing events. Intake cycles are modeled as event sequences in finite-state grammars. Classification of consumed food is realized by a finite-state grammar decoder based on the Viterbi algorithm. We achieved a detection accuracy of 83% and a food classification accuracy of 79% on a test set of 10% of all records. Our approach faces the need of monitoring the time and occurrence of eating. With differentiation of consumed food, a first step toward the goal of meal weight estimation is taken.

  20. Acoustic doppler velocity monitoring within Main Spring, Barton Springs, Austin, Texas, April-September 2004-enhancing the accuracy of springflow data

    Science.gov (United States)

    Asquith, W.H.; Gary, M.O.

    2005-01-01

    Acoustic Doppler velocity (ADV) meters are sophisticated underwater monitoring instruments that use sound waves to measure water velocity in as many as three directions. In April 2004, an ADV meter was installed inside the principal orifice and discharge point of Main Spring at Barton Springs in Austin, Texas. This instrument collects velocity data that can be used to enhance the accuracy of springflow data and identify previously unrecognized hydrologic patterns.An accurate record of springflow at Barton Springs is important for several reasons. First, Barton Springs is the only known habitat for the Barton Springs salamander (Eurycea sosorum), a federally-listed endangered species that is dependent on reliable springflow to survive. Determination of sustainable Edwards aquifer yields compatible with the survival of the species is impossible without an accurate springflow record. Second, the 3-acre swimming pool fed by Barton Springs is enjoyed by about 340,000 people per year (2003) and is an important tourist attraction. Third, Barton Springs provides a part of Austin's municipal water supply; water from Barton Springs discharges into Town Lake on the Colorado River about 0.4 mile upstream from one of Austin's three water-supply plants. Fourth, flow in Barton Springs reflects water levels in the Barton Springs segment of the Edwards aquifer, which currently (2005) is designated a sole-source aquifer by the U.S. Environmental Protection Agency. This report, prepared by the U.S. Geological Survey, briefly summarizes the results of recent ADV-based velocity and springflow data acquisition at Barton Springs and describes an application of velocity monitoring to enhance the accuracy of springflow data.

  1. Determination of tacrolimus crystalline fraction in the commercial immediate release amorphous solid dispersion products by a standardized X-ray powder diffraction method with chemometrics.

    Science.gov (United States)

    Rahman, Ziyaur; Siddiqui, Akhtar; Bykadi, Srikant; Khan, Mansoor A

    2014-11-20

    Clinical performance of an amorphous solid dispersion (ASD) drug product is related to the amorphous drug content because of the greater bioavailability of this form of the drug than its crystalline form. Therefore, it is paramount to monitor the amorphous and the crystalline fractions in the ASD products. The objective of the present investigation was to study the feasibility of using a standardized X-ray powder diffraction (XRPD) in conjunction with chemometric methods to quantitate the amorphous and crystalline fraction of the drug in several tacrolimus ASD products. Three ASD products were prepared in which drug to excipients ratios ranged from 1:19 to 1:49. The amorphous and crystalline drug products were mixed in various proportions so that amorphous/crystalline tacrolimus in the samples vary from 0 to 100%. XRPD of the samples of the drug products were collected, and PLSR and PCR chemometric methods were applied to the data. The R(2) was greater than '0.987' for all the models and bias in the models were statistically insignificant (p>0.05). RMSEP and SEP values were smaller for PLSR models than PCR models. The models prediction capabilities were good and can predict as low as 10% when drug to excipient ratio is as high as 1:49. In summary, XRPD and chemometric provide powerful analytical tools to monitor the crystalline fractions of the drug in the ASD products.

  2. Acoustic Emission Health Monitoring of Fill Purge COPV's Used in Aerospace and Automotive Applications and Designed for Long Cycle Life

    Science.gov (United States)

    Waller, Jess

    2013-01-01

    Cumulative composite damage in composite pressure vessels (CPVs) currently is not monitored on-orbit. Consequently, hazards due to catastrophic burst before leak (BBL) or compromised CPV reliability cannot be ascertained or mitigated, posing a risk to crew and mission assurance. The energy associated with CPV rupture can be significant, especially with high pressure gases are under containment, and the energy releases can be severe enough to cause injury, death, loss of assets or mission. Dual-Use Rationale: CPVs similar to those used by NASA on ISS, for example, are finding increasing use in automotive and transportation industry applications. These CPVs generally have a nonload sharing liner and are repeatedly filled over their service lifetime, typically with hydrogen or compressed natural gas (CNG). The same structural health monitoring equipment and software developed by NASA WSTF for evaluating, in real-time, the health of NASA CPVs on ISS will be used to evaluate the health of automotive CPVs, the only differences being the type and design of the CPV, and the in-service lifetime pressure histories. HSF Need(s)/Performance Characteristic(s) Supported: 1) Enable on-board vehicle systems management for mission critical functions at destinations with > 3 second time delay 2) Enable autonomous nominal operations and FDIR for crewed and un-crewed systems 3) Reduce on-board crew time to sustain and manage vehicle by factor of 2x at destinations with > 6 second time delay (see Crew Autonomy sheet) 4) Reduce earth-based mission ops "back room engineering" requirements for distant mission support delay (see Mission Autonomy sheet)

  3. 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

  4. 大型听神经瘤显微切除术中电生理监测的临床意义%Clinical significance of neurophysiological monitoring in microsurgery for large acoustic neuroma

    Institute of Scientific and Technical Information of China (English)

    戴易; 徐善水; 江晓春; 陶进; 陈建民; 王宣之; 狄广福; 夏大勇

    2012-01-01

    目的:探讨大型听神经瘤显微切除术中电生理监测对面神经功能的保护技巧及意义.方法:以2008年10月~2012年2月术中行电生理监测者为监测组(n=37),2006年1月~2008年7月术中未行电生理监测者为对照组(n=31).统计分析两组肿瘤全切除率、面神经解剖和功能保留率.结果:监测组的肿瘤全切除率、面神经解剖和功能保留率均明显高于对照组(P<0.05).结论:听神经瘤术中行电生理监测可有效保护面神经功能.%Objective: To assess the clinical significance of applying neurophysiological monitoring to preventing the facial nerve from injury during microsurgery of large acoustic neuroma. Methods: Between Oct. 2008 and Feb. 2012, 37 patients with large acoustic neuroma undergone microsurgery assisted with neurophysiological monitoring were recruited as monitored group, while another 31 undergone the similar surgery between Jan. 2006 and Jul. 2008 without monitoring were included in control group. Two groups were statistically compared regarding the total resection rate for the tumor, rates for both facial anatomical retaining and intact facial nerve function. Results: The results were significantly better in the monitored group than the control group concerning the total resection rate for the mass, retained anatomical facial nerve and facial nerve function pre-served( P < 0. 05 ). Conclusion: Applying neurophysiological monitoring to microsurgery for large acoustic neuroma may lead to preservation of facial nerve function.

  5. Speed of sound and acoustic attenuation of compounds affected during optoacoustic monitoring of thermal therapies measured in the temperature range from 5°C to 60°C

    Science.gov (United States)

    Oruganti, Tanmayi; Petrova, Elena; Oraevsky, Alexander A.; Ermilov, Sergey A.

    2015-03-01

    Optoacoustic (photoacoustic) imaging is being adopted for monitoring tissue temperature during hypothermic and hyperthermic cancer treatments. The technique's accuracy benefits from the knowledge of speed of sound (SoS) and acoustic coefficient of attenuation (AcA) as they change with temperature in biological tissues, blood, and acoustic lens of an ultrasound probe. In these studies we measured SoS and AcA of different ex vivo tissues and blood components (plasma and erythrocyte concentrates) in the temperature range from 5°C to 60°C. We used the technique based on measurements of time-delay and spectral amplitude of pressure pulses generated by wideband planar acoustic waves propagating through the interrogated medium. Water was used as a reference medium with known acoustic properties. In order to validate our experimental technique, we measured the temperature dependence of SoS and AcA for aqueous NaCl solution of known concentration and obtained the results in agreement with published data. Similar to NaCl solution and pure water, SoS in blood and plasma was monotonously increasing with temperature. However, SoS of erythrocyte concentrates displayed abnormalities at temperatures above 45°C, suggesting potential effects from hemoglobin denaturation and/or hemolysis of erythrocytes. On the contrary to aqueous solutions, the SoS in polyvinyl-chloride (plastisol) - a material frequently used for mimicking optical and acoustic properties of tissues - decreased with temperature. We also measured SoS and AcA in silicon material of an acoustic lens and did not observe temperature-related changes of SoS.

  6. Acoustic biosensors

    OpenAIRE

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

    2016-01-01

    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 ...

  7. 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.

  8. 数字化声发射技术在潜水器管道泄漏监测中的应用研究%Research on the application of digital acoustic emission technique to monitoring pipeline leakage for submersible

    Institute of Scientific and Technical Information of China (English)

    韦朋余; 岳亚霖; 张炜; 陈颖; 李盛华

    2012-01-01

    In order to study on the feasibility of digital acoustic emission technique to monitoring pipeline leakage for submersible, a combination system was constructed to simulate the acoustic emission pipeline leak detection. Acoustic emission channel acquisition parameters for pipeline leakage of submersible were proposed. The effectivity and practicability of system was verified by the experimental investigation of submersible pipeline leakage. Meanwhile, through statistical analysis and Fourier transformation of acoustic emission signal parameters, summarization of change regulation of RMS (root mean square), ASL (average signal level), energy and frequency with propagation distance and pressure was discovered. This study may provide material foundation and technical support for the acoustic emission real-time monitor to submersible in service.%为了研究数字化声发射技术在潜水器管道泄漏监测中的可行性,文章创建了管道泄漏声发射检测系统,提出了应用于潜水器管道泄漏的声发射通道采集控制参数,对潜水器管道泄漏现象进行了试验研究,验证了系统的有效性和实用性.同时通过对管道泄漏声发射信号参数的统计分析和傅里叶变换,获得了潜水器管道泄漏声发射信号的RMS、ASL、能量以及频率等幅频响应特性随传播距离和管道内部压力的变化规律,为在潜水器服役过程中进行声发射实时监测提供物质基础和技术支撑.

  9. Implementation of chemometrics in quality evaluation of food and beverages.

    Science.gov (United States)

    Efenberger-Szmechtyk, Magdalena; Nowak, Agnieszka; Kregiel, Dorota

    2017-01-27

    Conventional methods for food quality evaluation based on chemical or microbiological analysis followed by traditional univariate statistics such as ANOVA are considered insufficient for some purposes. More sophisticated instrumental methods including spectroscopy and chromatography, in combination with multivariate analysis - chemometrics, can be used to determine food authenticity, identify adulterations or mislabeling and determine food safety. The purpose of this review is to present the current state of knowledge on the use of chemometric tools for evaluating quality of food products of animal and plant origin and beverages. The article describes applications of several multivariate techniques in food and beverages research, showing their showing their role in adulteration detection, authentication, quality control, differentiation of samples and comparing their classification and prediction ability.

  10. Aespoe Hard Rock Laboratory. Prototype Repository. Acoustic emission and ultrasonic monitoring results from deposition hole DA3545G01 in the Prototype Repository between October 2007 and March 2008

    Energy Technology Data Exchange (ETDEWEB)

    Duckworth, D.; Haycox, J.; Pettitt, W.S. (Applied Seismology Consultants, Shrewsbury (United Kingdom))

    2008-12-15

    This report describes results from acoustic emission (AE) and ultrasonic monitoring around a canister deposition hole (DA3545G01) in the Prototype Repository Experiment at SKB's Hard Rock Laboratory (HRL), Sweden. The experiment has been designed to simulate a disposal tunnel in a real deep repository environment for storage of high-level radioactive waste. The test consists of a 90 m long, 5 m diameter subhorizontal tunnel excavated in dioritic granite. The monitoring aims to examine changes in the rock mass caused by an experimental repository environment, in particular due to thermal stresses induced from canister heating and pore pressures induced from tunnel sealing.

  11. 声发射技术在抽杆疲劳实验中的应用%Application of acoustic emission (AE) technique in crack monitor during fatigue test of pump rods

    Institute of Scientific and Technical Information of China (English)

    夏永发; 李海玲

    2007-01-01

    The acoustic emission(AE)real time monitoring of fatigue damage of pump rods samples during fatigue test was introduced.Under severe environmental noise caused by vibration,the real time monitoring of the fatigue crack initiation and expansion was realized successfully by using the parameters analysis method combined by AE Hits and Amplitude.The characters of the methods are simple and real time,which can provide a more accurate and impersonal basis for judging whether the fatigue test piece has been destroyed,thus can provide a scientific assistant method for accurately determining the life of pump rod.

  12. Aespoe Hard Rock Laboratory. Prototype Repository. Acoustic emission and ultrasonic monitoring results from deposition hole DA3545G01 in the Prototype Repository between October 2007 and March 2008

    Energy Technology Data Exchange (ETDEWEB)

    Duckworth, D.; Haycox, J.; Pettitt, W.S. (Applied Seismology Consultants, Shrewsbury (United Kingdom))

    2008-12-15

    This report describes results from acoustic emission (AE) and ultrasonic monitoring around a canister deposition hole (DA3545G01) in the Prototype Repository Experiment at SKB's Hard Rock Laboratory (HRL), Sweden. The experiment has been designed to simulate a disposal tunnel in a real deep repository environment for storage of high-level radioactive waste. The test consists of a 90 m long, 5 m diameter subhorizontal tunnel excavated in dioritic granite. The monitoring aims to examine changes in the rock mass caused by an experimental repository environment, in particular due to thermal stresses induced from canister heating and pore pressures induced from tunnel sealing.

  13. Solvent effect modelling of isocyanuric products synthesis by chemometric methods

    OpenAIRE

    Havet, Jean-Louis; Billiau-Loreau, Myriam; Porte, Catherine; Delacroix, Alain

    2002-01-01

    Chemometric tools were used to generate the modelling of solvent e¡ects on the N-alkylation of an isocyanuric acid salt. The method proceeded from a central composite design applied on the Carlson solvent classification using principal components analysis. The selectivity of the reaction was studied from the production of different substituted isocyanuric derivatives. Response graphs were obtained for each compound and used to devise a strategy for solvent selection. The prediction models wer...

  14. Application of chemometric methods for assessment and modelling of microbiological quality data concerning coastal bathing water in Greece

    Directory of Open Access Journals (Sweden)

    Agelos Papaioannou

    2014-12-01

    Full Text Available Background. Worldwide, the aim of managing water is to safeguard human health whilst maintaining sustainable aquatic and associated terrestrial, ecosystems. Because human enteric viruses are the most likely pathogens responsible for waterborne diseases from recreational water use, but detection methods are complex and costly for routine monitoring, it is of great interest to determine the quality of coastal bathing water with a minimum cost and maximum safety. Design and methods. This study handles the assessment and modelling of the microbiological quality data of 2149 seawater bathing areas in Greece over 10-year period (1997-2006 by chemometric methods. Results. Cluster analysis results indicated that the studied bathing beaches are classified in accordance with the seasonality in three groups. Factor analysis was applied to investigate possible determining factors in the groups resulted from the cluster analysis, and also two new parameters were created in each group; VF1 includes E. coli, faecal coliforms and total coliforms and VF2 includes faecal streptococci/enterococci. By applying the cluster analysis in each seasonal group, three new groups of coasts were generated, group A (ultraclean, group B (clean and group C (contaminated. Conclusions. The above analysis is confirmed by the application of discriminant analysis, and proves that chemometric methods are useful tools for assessment and modeling microbiological quality data of coastal bathing water on a large scale, and thus could attribute to effective and economical monitoring of the quality of coastal bathing water in a country with a big number of bathing coasts, like Greece.

  15. Chemometric analysis of metal contents in different types of chocolates

    Directory of Open Access Journals (Sweden)

    Jevrić Lidija R.

    2014-01-01

    Full Text Available The relationships between the contents of various metals (Cu, Ni, Pb and Al in 38 different milk chocolate samples were studied using a chemometric approach. The chemometric expressions were generated using a training set of 25 chocolate samples and the predictive ability of the resulting models was evaluated against a test set of 13 chocolate samples. The chemometric analysis was based on the application of multiple linear regression analysis (MLR. MLR was performed in order to select the significant models for predicting the metal contents. The MLR equations that represent the content of one metal as a function of the contents of other metals were established. High agreement between experimental and predicted values, obtained in the validation procedure, indicated the good quality of the models. It enables the researchers to establish reliable relationships between the contents of various metals which can be used for their prediction in different types of chocolate prior to their analysis. This can reduce the trial-and-error element and experimental costs in the production.[Projekat Ministarstva nauke Republike Srbije, br. 31055, br. 172012 i br. 172014

  16. A novel storage method for near infrared spectroscopy chemometric models.

    Science.gov (United States)

    Zhang, Zhi-Min; Chen, Shan; Liang, Yi-Zeng

    2010-06-04

    Chemometric Modeling Markup Language (CMML) is developed by us for containing chemometrics models within one document through converting binary data into strings by base64 encode/decode algorithms to solve the interoperability issue in sharing chemometrics models. It provides a base functionality for storage of sampling, variable selection, pretreating, outlier and modeling parameters and data. With the help of base64 algorithm, the usability of CMML is in equilibrium with size by transforming the binary data into base64 encoded string. Due to the advantages of Extensible Markup Language (XML), models stored in CMML can be easily reused in various other software and programming languages as long as the programming language has XML parsing library. One can also use the XML Path Language (XPath) query language to select desired data from the CMML file effectively. The application of this language in near infrared spectroscopy model storage is implemented as a class in C++ language and available as open source software (http://code.google.com/p/cmml), and the implementations in other languages, such as MATLAB and R are in progress.

  17. Aespoe Hard Rock Laboratory. Prototype Repository. Acoustic emission and ultrasonic monitoring results from deposition hole DA3545G01 in the Prototype Repository between April 2008 and September 2008

    Energy Technology Data Exchange (ETDEWEB)

    Duckworth, D.; Haycox, J.; Pettitt, W.S. (Applied Seismology Consultants, Shrewsbury (United Kingdom))

    2009-03-15

    This report describes results from acoustic emission (AE) and ultrasonic monitoring around a canister deposition hole (DA3545G01) in the Prototype Repository Experiment at SKB's Hard Rock Laboratory (HRL), Sweden. The monitoring aims to examine changes in the rock mass caused by an experimental repository environment, in particular due to thermal stresses induced from canister heating and pore pressures induced from tunnel sealing. Monitoring of this volume has previously been performed during excavation [Pettitt et al., 1999], and during stages of canister heating and tunnel pressurisation [Haycox et al., 2005a and 2005b; Haycox et al., 2006a and 2006b; Zolezzi et al., 2007 and Duckworth et al., 2008]. Further information on this monitoring can be found in Appendix I. This report covers the period between 1st April 2008 and 30th September 2008 and is the seventh instalment of the 6-monthly processing and interpretation of the results from the experiment.

  18. Aespoe Hard Rock Laboratory. Prototype Repository. Acoustic emission and ultrasonic monitoring results from deposition hole DA3545G01 in the Prototype Repository between April 2008 and September 2008

    Energy Technology Data Exchange (ETDEWEB)

    Duckworth, D.; Haycox, J.; Pettitt, W.S. (Applied Seismology Consultants, Shrewsbury (United Kingdom))

    2009-03-15

    This report describes results from acoustic emission (AE) and ultrasonic monitoring around a canister deposition hole (DA3545G01) in the Prototype Repository Experiment at SKB's Hard Rock Laboratory (HRL), Sweden. The monitoring aims to examine changes in the rock mass caused by an experimental repository environment, in particular due to thermal stresses induced from canister heating and pore pressures induced from tunnel sealing. Monitoring of this volume has previously been performed during excavation [Pettitt et al., 1999], and during stages of canister heating and tunnel pressurisation [Haycox et al., 2005a and 2005b; Haycox et al., 2006a and 2006b; Zolezzi et al., 2007 and Duckworth et al., 2008]. Further information on this monitoring can be found in Appendix I. This report covers the period between 1st April 2008 and 30th September 2008 and is the seventh instalment of the 6-monthly processing and interpretation of the results from the experiment.

  19. Outcomes of facial nerve reservation during acoustic neuroma surgery under neural electrophysiological monitoring%神经电生理监测在听神经瘤切除术中保留面神经的效果

    Institute of Scientific and Technical Information of China (English)

    张旸; 徐海涛; 许媛; 陆小明; 刘宁; 鲁艾林

    2015-01-01

    Objective To summarize the outcomes of facial nerve reservation during acoustic neuroma surgery under neural electrophysiological monitoring .Methods Acoustic neuroma resection under microscope was performed via suboccipital retrosigmoid approach in 161 patients .Intraoperative continuous monitoring of evoked potential of the facial nerve was carried out during operation .The facial nerve function was valuated during and after surgery .Results The results of facial nerve function after surgery in 101 cases were consistent with those monitored during operation with an accordance rate of 62.7% .Conclusion The anatomy and facial nerve reservation during acoustic neuroma resection can be improved by intraoperative continuous monitoring of evoked potential of the facial nerve .Some interference factors need to be eliminated in order to improve the accuracy of intraoperative neurophysiological monitoring .%目的:总结电生理监测对听神经瘤术中保留面神经的效果。方法听神经瘤患者161例,采用经枕下乙状窦后入路,显微镜下实施听神经瘤切除术。术中采用神经电生理技术监测面神经诱发电位;术中和术后评估面神经功能。结果术后面神经功能评估结果与术中神经电生理监测结果一致率为62.7%(101/161)。结论神经电生理监测技术应用于听神经瘤显微外科手术可提高面神经解剖和神经功能保留效果;但同时应排除干扰因素,提高电生理监测的准确性。

  20. 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.

  1. Overview of the Usage of Chemometric Methods for Remediation Techniques of Radionuclides

    Science.gov (United States)

    Yilmaz, C.; Aslani, M. A. A.

    The aim of this study is to investigate the treatment of chemometric tools on remediation techniques for removal of Cs-137, Sr-90 and Ra-226 from environmental samples. In this study; statistical data are collected from literature about applications of chemometric methods.

  2. Characterization and Classification of Crude Oils Using a Combination of Spectroscopy and Chemometrics

    NARCIS (Netherlands)

    Peinder, Peter de

    2009-01-01

    Research has been carried out to the utility of chemometric models to predict long residue (LR) and short residue (SR) properties of a crude oil directly from its absorption or magnetic resonance spectrum. Such a combined spectroscopic-chemometric approach might offer a fast alternative for the elab

  3. 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...... 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...

  4. Radiation acoustics

    CERN Document Server

    Lyamshev, Leonid M

    2004-01-01

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

  5. Monitoring microbe-induced physical property changes using high-frequency acoustic waveform data: Toward the development of a microbial megascope

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Kenneth Hurst

    2002-05-20

    A laboratory investigation was undertaken to determine the effect of microbe generated gas bubbles in controlled, saturated sediment columns utilizing a novel technique involving acoustic wave propagation. Specifically, the effect of denitrifying bacteria on saturated flow conditions was evaluated in light of the stimulated production of N{sub 2} gas and the resulting plugging of the pore throats. The propagation of high frequency acoustic waves through the sediment columns was used to locate those regions in the column where gas accumulation occurred. Over a period of six weeks, regions of gas accumulation resulted in the attenuation of acoustic wave energies with the decreases in amplitude typically greater than one order of magnitude.

  6. Assessing the performance of the photo-acoustic infrared gas monitor for measuring CO(2), N(2)O, and CH(4) fluxes in two major cereal rotations.

    Science.gov (United States)

    Tirol-Padre, Agnes; Rai, Munmun; Gathala, Mahesh; Sharma, Sheetal; Kumar, Virender; Sharma, Parbodh C; Sharma, Dinesh K; Wassmann, Reiner; Ladha, Jagdish

    2014-01-01

    Rapid, precise, and globally comparable methods for monitoring greenhouse gas (GHG) fluxes are required for accurate GHG inventories from different cropping systems and management practices. Manual gas sampling followed by gas chromatography (GC) is widely used for measuring GHG fluxes in agricultural fields, but is laborious and time-consuming. The photo-acoustic infrared gas monitoring system (PAS) with on-line gas sampling is an attractive option, although it has not been evaluated for measuring GHG fluxes in cereals in general and rice in particular. We compared N2 O, CO2 , and CH4 fluxes measured by GC and PAS from agricultural fields under the rice-wheat and maize-wheat systems during the wheat (winter), and maize/rice (monsoon) seasons in Haryana, India. All the PAS readings were corrected for baseline drifts over time and PAS-CH4 (PCH4 ) readings in flooded rice were corrected for water vapor interferences. The PCH4 readings in ambient air increased by 2.3 ppm for every 1000 mg cm(-3) increase in water vapor. The daily CO2 , N2 O, and CH4 fluxes measured by GC and PAS from the same chamber were not different in 93-98% of all the measurements made but the PAS exhibited greater precision for estimates of CO2 and N2 O fluxes in wheat and maize, and lower precision for CH4 flux in rice, than GC. The seasonal GC- and PAS-N2 O (PN2 O) fluxes in wheat and maize were not different but the PAS-CO2 (PCO2 ) flux in wheat was 14-39% higher than that of GC. In flooded rice, the seasonal PCH4 and PN2 O fluxes across N levels were higher than those of GC-CH4 and GC-N2 O fluxes by about 2- and 4fold, respectively. The PAS (i) proved to be a suitable alternative to GC for N2 O and CO2 flux measurements in wheat, and (ii) showed potential for obtaining accurate measurements of CH4 fluxes in flooded rice after making correction for changes in humidity.

  7. Study Acoustic Emissions from Composites

    Science.gov (United States)

    Walker, James; Workman,Gary

    1998-01-01

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

  8. 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....

  9. 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...

  10. 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...

  11. Room Acoustics

    Science.gov (United States)

    Kuttruff, Heinrich; Mommertz, Eckard

    The traditional task of room acoustics is to create or formulate conditions which ensure the best possible propagation of sound in a room from a sound source to a listener. Thus, objects of room acoustics are in particular assembly halls of all kinds, such as auditoria and lecture halls, conference rooms, theaters, concert halls or churches. Already at this point, it has to be pointed out that these conditions essentially depend on the question if speech or music should be transmitted; in the first case, the criterion for transmission quality is good speech intelligibility, in the other case, however, the success of room-acoustical efforts depends on other factors that cannot be quantified that easily, not least it also depends on the hearing habits of the listeners. In any case, absolutely "good acoustics" of a room do not exist.

  12. Improved design of multi-beam underwater acoustic monitoring system for fish in offshore fish cage%深水网箱多波束水声鱼群状态监测仪的改进设计

    Institute of Scientific and Technical Information of China (English)

    彭阳明; 许肖梅; 张小康

    2011-01-01

    针对离岸深水网箱养殖的鱼群安全问题,采用多波束水声技术监测鱼群状态的方法.结合信号处理技术、通用分组无线业务(GPRS)无线传输技术及串口通信技术,开发了一套多波束水声鱼群状态监测仪.监测仪完成1次网箱扫描只需5s;实现了监测数据的即采即发功能,提高了系统的实时性;改进了电路结构,降低了系统复杂度,减小了系统体积,降低了成本.试验表明,监测仪操作简便,性能稳定,能有效完成深水网箱的实时监测任务.%To the security issue of fish shoal in offshore fish cage, a monitoring method based on multi-beam underwater acoustic technique is employed. Integrating with the techniques of signal processing, GPRS wireless data communication and serial interface communication, a multi-beam underwater acoustic monitoring system for breeding fish in offshore fish cage is designed. It takes only five second to accomplish an entire cage scanning. Detecting data are delivered to the user monitoring system immediately upon acquisition, which improves the real-time property of the system. As its circuit is improved, the system structure is simplified. Both the volume and the cost of the monitor is reduced. Tests show that the monitoring system is simplified, easy placement and robust under different environmental conditions. It is well performed in real-time monitoring fish in offshore fish cage.

  13. Acoustic Bat Inventory and Monitoring

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Sheldon-Hart Mountain National Wildlife Refuge Complex (Complex) occupies close to 1 million acres in the Great Basin. In 2009 and 2010, the Complex initiated...

  14. Prediction of class membership of biodiesels using chemometrics.

    Science.gov (United States)

    Mustafa, Zylia; Milina, Rumyana; Simeonova, Pavlina A; Tsakovski, Stefan L; Simeonov, Vasil D

    2015-01-01

    Recently, serious scientific and technological attention is paid to creation of alternative energy sources, including biofuels. The assessment of the quality of the biofuels produced and of the raw materials needed for the production technology is an important scientific challenge. One of the major sources for biodiesel production is plant oils material (sunflower, rapeseed, palm, soya etc.). Since plants are complex system from the biota it is not easy to find specific chemical components responsible for their ability to serve as biodiesels. The characterization and classification of plant sources as biofuel material could be reliably estimated only by the use of multivariate statistical approaches (chemometrics). The chemometric expertise makes it possible not only to classify different biofuel sources into similarity classes but also to predict the membership of unknown by origin chemically analyzed samples to already existing classes. The present study deals with the prediction of the class membership of several unknown by origin samples, which are included in a large data set with FAME profiles of biodiesel plant sources. Using a data set from chromatographic analysis of fatty acid methyl esters profiles (FAME) of different plant biodiesel sources and applying the chemometric technique know as partial least squares-discriminant analysis (PLS - DA) a pattern recognition procedure is developed to: I. Model classes of similarity of biodiesel plant sources using their FAME profiles not taking into account the samples with unknown origin; II. Classify correctly the samples with unknown origin to the previously defined classes of biodiesel sources (palm oil, soybean oil, peanut oil, rapeseed oil, sunflower oil and maize oil). The prediction is successfully achieved for all samples with previously unknown origin. This pattern recognition approach is applied for the first time in the field of biodiesel classification and modeling tasks.

  15. Using an autonomous passive acoustic observational system to monitor the environmental impact of the Gulf of Mexico oil spill on deep-diving marine mammals

    Science.gov (United States)

    Sidorovskaia, N.; Ackleh, A.; Ma, B.; Tiemann, C.; Ioup, J. W.; Ioup, G. E.

    2012-12-01

    The Littoral Acoustic Demonstration Center (LADC) is a consortium of scientists from four universities and the U.S. Navy, which performs acoustic measurements and analysis in littoral waters. For the present work, six passive autonomous broadband acoustic sensors were deployed by LADC in the vicinity of the Deep Water Horizon oil spill site in the Northern Gulf of Mexico in fall 2010. The objective of the project is to assess long-term impact of the spill on the deep-diving residential population of marine mammals, particularly, sperm and beaked whales. Collected data were processed to detect, extract, and count acoustic signals produced by different types of marine mammals. As a next step, a statistical model which uses acoustic inputs was developed to estimate residential populations of different types of marine mammals at different distances from the spill site. The estimates were compared to population estimates from years prior to the spill, using pre-spill collected data in the area by LADC from 2001, 2002, and 2007. The results indicate different responses from sperm and beaked whales in the first months following the spill. A recently published article by our research group (Ackleh et al., J. Acoust. Soc. Am. 131, 2306-2314) provides a comparison of 2007 and 2010 estimates showing a decrease in acoustic activity and abundance of sperm whales at the 9-mile distant site, whereas acoustic activity and abundance at the 25-mile distant site has clearly increased. This may indicate that some sperm whales have relocated farther away from the spill subject to food source availability. The beaked whale population appears to return to 2007 numbers after the spill even at the closest 9-mile distant site. Several acoustically observed changes in the animals' habitat associated with the spill, such as anthropogenic noise level, prey presence, etc., can be connected with the observed population trends. Preliminary results for interpreting observed population trends will

  16. A primer to nutritional metabolomics by NMR spectroscopy and chemometrics

    DEFF Research Database (Denmark)

    Savorani, Francesco; Rasmussen, Morten Arendt; Mikkelsen, Mette Skau

    2013-01-01

    This paper outlines the advantages and disadvantages of using high throughput NMR metabolomics for nutritional studies with emphasis on the workflow and data analytical methods for generation of new knowledge. The paper describes one-by-one the major research activities in the interdisciplinary...... structures for multivariate pattern recognition methods and (3) NMR for providing a unique fingerprint of the lipoprotein status of the subject. For the first time in history, by combining NMR spectroscopy and chemometrics we are able to perform inductive nutritional research as a complement to the deductive...

  17. Monitoring microbe-induced physical property changes using high-frequency acoustic waveform data: Toward the development of a microbial megascope

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Kenneth Hurst [Univ. of California, Berkeley, CA (United States)

    2002-01-01

    A laboratory investigation was undertaken to determine the effect of microbe generated gas bubbles in controlled, saturated sediment columns utilizing a novel technique involving acoustic wave propagation. Specifically, the effect of denitrifying bacteria on saturated flow conditions was evaluated in light of the stimulated production of N2 gas and the resulting plugging of the pore throats. The propagation of high frequency acoustic waves through the sediment columns was used to locate those regions in the column where gas accumulation occurred. Over a period of six weeks, regions of gas accumulation resulted in the attenuation of acoustic wave energies with the decreases in amplitude typically greater than one order of magnitude.

  18. Analysis of acoustic emission signals of fatigue crack growth and corrosion processes. Investigation of the possibilities for continuous condition monitoring of transport containers by acoustic emission testing; Analyse der Schallemissionssignale aus Ermuedungsrisswachstum und Korrosionsprozessen. Untersuchung der Moeglichkeiten fuer die kontinuierliche Zustandsueberwachung von Transportbehaeltern mittels Schallemissionspruefung

    Energy Technology Data Exchange (ETDEWEB)

    Wachsmuth, Janne

    2016-05-01

    Fatigue crack growth and active corrosion processes are the main causes of structural failures of transport products like road tankers, railway tank cars and ships. To prevent those failures, preventive, time-based maintenance is performed. However, preventive inspections are costly and include the risk of not detecting a defect, which could lead to a failure within the next service period. An alternative is the idea of continuous monitoring of the whole structure by means of acoustic emission testing (AT). With AT, defects within the material shall be detected and repaired directly after their appearance. Acoustic emission testing is an online non-destructive testing method. Acoustic emission (AE) arises from changes within the material and is transported by elastic waves through the material. If the AE event generates enough energy, the elastic wave propagates to the boundaries of the component, produces a displacement in the picometre scale and can be detected by a piezoelectric sensor. The sensor produces an electrical signal. From this AE signal, AE features such as the maximum amplitude or the frequency can be extracted. Methods of signal analysis are used to investigate the time and frequency dependency of signal groups. The purpose of the signal analysis is to connect the AE signal with the originating AE source. If predefined damage mechanisms are identified, referencing the damage condition of the structure is possible. Acoustic emission from events of the actual crack propagation process can for example lead to the crack growth rate or the stress intensity factor, both specific values from fracture mechanics. A new development in the domain of acoustic emission testing is the pattern recognition of AE signals. Specific features are extracted from the AE signals to assign them to their damage mechanisms. In this thesis the AE signals from the damage mechanisms corrosion and fatigue crack growth are compared and analysed. The damage mechanisms were

  19. Acoustic biosensors

    Science.gov (United States)

    Fogel, Ronen; Seshia, Ashwin A.

    2016-01-01

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

  20. Chemometric techniques in oil classification from oil spill fingerprinting.

    Science.gov (United States)

    Ismail, Azimah; Toriman, Mohd Ekhwan; Juahir, Hafizan; Kassim, Azlina Md; Zain, Sharifuddin Md; Ahmad, Wan Kamaruzaman Wan; Wong, Kok Fah; Retnam, Ananthy; Zali, Munirah Abdul; Mokhtar, Mazlin; Yusri, Mohd Ayub

    2016-10-15

    Extended use of GC-FID and GC-MS in oil spill fingerprinting and matching is significantly important for oil classification from the oil spill sources collected from various areas of Peninsular Malaysia and Sabah (East Malaysia). Oil spill fingerprinting from GC-FID and GC-MS coupled with chemometric techniques (discriminant analysis and principal component analysis) is used as a diagnostic tool to classify the types of oil polluting the water. Clustering and discrimination of oil spill compounds in the water from the actual site of oil spill events are divided into four groups viz. diesel, Heavy Fuel Oil (HFO), Mixture Oil containing Light Fuel Oil (MOLFO) and Waste Oil (WO) according to the similarity of their intrinsic chemical properties. Principal component analysis (PCA) demonstrates that diesel, HFO, MOLFO and WO are types of oil or oil products from complex oil mixtures with a total variance of 85.34% and are identified with various anthropogenic activities related to either intentional releasing of oil or accidental discharge of oil into the environment. Our results show that the use of chemometric techniques is significant in providing independent validation for classifying the types of spilled oil in the investigation of oil spill pollution in Malaysia. This, in consequence would result in cost and time saving in identification of the oil spill sources.

  1. 面神经电生理监测在大型听神经瘤术中的应用%Intraoperative electrophysiologic monitoring of the facial nerve in operation of large acoustic neuromas

    Institute of Scientific and Technical Information of China (English)

    赵学明; 药天乐; 万大海; 王永红; 范益民; 郝解贺

    2011-01-01

    Objective To explore intraoperative protection of facial nerve and evaluate its function after operation in large acoustic neuromas surgery by electrophysiologic monitoring. Method A total of 42 patients'clinical data with large acoustic neuromas between Jun, 2007 and Mar, 2010 were analyzed retrospectively,who were treated microsurgically with intraoperative electrophysiological monitoring in our department. Results The facial nerve was preserved anatomically in 37 patients (88%). The function of facial nerve was kept well in 30 cases (71%). Stimulative intensity of 1 ~ 3 V at the end of operation is related to the good function of facial nerve. The proximal - to - distal amplitude ratio of facial nerve after surgery less than 0. 3 presented with a bad facial function. ConclusionsIntraoperative monitoring has significantly decreased facial nerve morbidity in large acoustic neuromas surgery. Stimulative intensity at the exit of facial nerve from brainstem is related to the facial nerve function negatively. The proximal - to - distal amplitude ratio can predict the facial nerve function positively following acoustic neuromas resection.%目的 探讨大型听神经瘤术中面神经监测对面神经保护及评估术后面神经功能的临床意义。方法回顾性分析我科2007年6月至2010年3月术中行面神经监测的42例大型听神经瘤的临床资料。结果 面神经解剖保留37例(88%),面神经功能保留30例(71%)。术末刺激强度1~3V即引起肌电反应者预后良好;而术末面神经近端与远端波幅之比<0.3者预后差。结论 大型听神经瘤术中面神经监测可显著降低术后面神经瘫痪的发生率,术末面神经脑干端的刺激强度与面神经功能呈负相关,而面神经近端与远端波幅之比与面神经功能呈正相关。

  2. Odontocete Studies on the Pacific Missile Range Facility in July/August 2013: Satellite-Tagging, Photo-Identification, and Passive Acoustic Monitoring

    Science.gov (United States)

    2014-05-02

    beaked whale vocalizations when questions arise. It has also proven useful for collecting time and frequency images and broadband cuts of selected...Applied Acoustics 67:1091-1105. Moretti, D.J, T. Marques , L. Thomas, N. DiMarzio, A. Dilley, R. Morrissey, E. McCarthy, J. Ward, and S. Jarvis. 2010

  3. The Role of Intraoperative Facial Nerve Monitoring in Acoustic Neuroma Resection%术中神经监测在听神经瘤切除术中对面神经的保护作用

    Institute of Scientific and Technical Information of China (English)

    沈上杭; 王占祥; 陈玉英; 刘希尧; 谭国伟; 郭剑锋

    2009-01-01

    BACKGROUND & OBJECTIVE: To maintain the anatomic and functional intactness of facial nerve is one of the goal of acoustic neuroma resection. In this article, we investigated the role of intraoperative facial nerve monitoring in acoustic neuroma resection. METHODS: Clinical data of 57 patients with acoustic neuroma treated in our hospital were retrospectively analyzed. Among 57 patients, tumors were removed under microscope without intranperative facial nerve monitoring in 35 cases and with intraoperative monitoring in 22 cases. Post operative facial nerve function was followed up in all patients. RESULTS: House-Brackmann system was used for evaluating the function of facial nerve 3 months after operation. Among 22 cases with intraoperative facial nerve monitoring, facial nerve intactness was observed in 18 cases, Grade Ⅰ facial paralysis in 2 cases and Grade Ⅱ facial paralysis in 2 cases, repectively. The monitoring group had 2 cases Among 35 cases without intracperative facial nerve monitoring, intact faical function was observed in 14 cases, Grade Ⅰfacial paralysis in 12 cases, Grade Ⅱ facial paralysis in 6 cases, grade Ⅲ facial paralysis in 2 cases, and Grade Ⅴ facial paralysis in 1 case, respectively.Patients with intraoperative facial nervemonitoring had better performance in facial nerve function than those without monitoring (P< 0.05). CONCLUSION: Intraoperative nerve monitoring techniques facilitates the localization and preservation of the facial nerve in acoustic neuroma resection.%背景与目的:面神经瘫痪是听神经瘤切除术中最常见的并发症,近年来随着术中神经监测技术的应用,术后面神经功能已得到较好的保护.本研究旨在探讨术中神经监测在听神经瘤手术中对面神经功能的保护作用.方法:分析本院收治手术的57例听神经瘤患者,其中直接显微镜下切除肿瘤(非监测组)35例,显微镜下切除肿瘤过程中使用术中神经监测仪对

  4. Droplets Acoustics

    CERN Document Server

    Dahan, Raphael; Carmon, Tal

    2015-01-01

    Contrary to their capillary resonances (Rayleigh, 1879) and their optical resonances (Ashkin, 1977), droplets acoustical resonances were rarely considered. Here we experimentally excite, for the first time, the acoustical resonances of a droplet that relies on sound instead of capillary waves. Droplets vibrations at 37 MHz rates and 100 quality factor are optically excited and interrogated at an optical threshold of 68 microWatt. Our vibrations span a spectral band that is 1000 times higher when compared with drops previously-studied capillary vibration.

  5. ACOUSTIC EMISSION ANALYZER

    Directory of Open Access Journals (Sweden)

    J. J. Almeida-Pérez

    2004-12-01

    Full Text Available In this paper appears a solution for acoustic emission analysis commonly known as noise. For the accomplishmentof this work a personal computer is used, besides sensors (microphones and boards designed and built for signalconditioning. These components are part of a virtual instrument used for monitoring the acoustical emission. Themain goal of this work is to develop a virtual instrument that supplies many important data as the result of ananalysis allowing to have information in an easy and friendly way. Moreover this information is very useful forstudying and resolving several situations in planning, production and testing areas.The main characteristics of the virtual instrument are: signal analysis in time, effective power measurement inDecibels (dB, average intensity taken from the principle of paired microphones, as well as the data analysis infrequency. These characteristics are included to handle two information channels.

  6. Chemometric Classification of Herb – Orthosiphon stamineus According to Its Geographical Origin Using Virtual Chemical Sensor Based Upon Fast GC

    Directory of Open Access Journals (Sweden)

    Ezrinda Mohd Zaihidee

    2003-10-01

    Full Text Available An analytical method using Electronic Nose (E-nose instrument for analysis of volatile organic compound from Orthosiphon stamineus raw samples have been developed. This instrument is a new chemical sensor based on Fast Gas Chromatography and Surface Acoustics Wave (SAW detector. Chromatographic fingerprint obtained from the headspace analysis of O. stamineus samples were used as a guideline for optimum selection of an array of sensor. Qualitative analysis was carried out based on the responses of each sensor array in order to distinguish the geographical origin of the cultivated sample. The results of the analysis showed variances of volatile chemical compound of the samples even though it is from the same species. However, similarities of main components from all five samples were observed. Usage of pattern recognition chemometric approaches such as Principal Component Analysis (PCA, Linear Discriminant Analysis (LDA and Cluster Analysis (CA for processing instrumental data provided good classification of O. stamineus samples according to its geographical origin.

  7. Chemometric classification techniques as a tool for solving problems in analytical chemistry.

    Science.gov (United States)

    Bevilacqua, Marta; Nescatelli, Riccardo; Bucci, Remo; Magrì, Andrea D; Magrì, Antonio L; Marini, Federico

    2014-01-01

    Supervised pattern recognition (classification) techniques, i.e., the family of chemometric methods whose aim is the prediction of a qualitative response on a set of samples, represent a very important assortment of tools for solving problems in several areas of applied analytical chemistry. This paper describes the theory behind the chemometric classification techniques most frequently used in analytical chemistry together with some examples of their application to real-world problems.

  8. [Prediction of Encapsulation Temperatures of Copolymer Films in Photovoltaic Cells Using Hyperspectral Imaging Techniques and Chemometrics].

    Science.gov (United States)

    Lin, Ping; Chen, Yong-ming; Yao, Zhi-lei

    2015-11-01

    A novel method of combination of the chemometrics and the hyperspectral imaging techniques was presented to detect the temperatures of Ethylene-Vinyl Acetate copolymer (EVA) films in photovoltaic cells during the thermal encapsulation process. Four varieties of the EVA films which had been heated at the temperatures of 128, 132, 142 and 148 °C during the photovoltaic cells production process were used for investigation in this paper. These copolymer encapsulation films were firstly scanned by the hyperspectral imaging equipment (Spectral Imaging Ltd. Oulu, Finland). The scanning band range of hyperspectral equipemnt was set between 904.58 and 1700.01 nm. The hyperspectral dataset of copolymer films was randomly divided into two parts for the training and test purpose. Each type of the training set and test set contained 90 and 10 instances, respectively. The obtained hyperspectral images of EVA films were dealt with by using the ENVI (Exelis Visual Information Solutions, USA) software. The size of region of interest (ROI) of each obtained hyperspectral image of EVA film was set as 150 x 150 pixels. The average of reflectance hyper spectra of all the pixels in the ROI was used as the characteristic curve to represent the instance. There kinds of chemometrics methods including partial least squares regression (PLSR), multi-class support vector machine (SVM) and large margin nearest neighbor (LMNN) were used to correlate the characteristic hyper spectra with the encapsulation temperatures of of copolymer films. The plot of weighted regression coefficients illustrated that both bands of short- and long-wave near infrared hyperspectral data contributed to enhancing the prediction accuracy of the forecast model. Because the attained reflectance hyperspectral data of EVA materials displayed the strong nonlinearity, the prediction performance of linear modeling method of PLSR declined and the prediction precision only reached to 95%. The kernel-based forecast models were

  9. Quality control of the paracetamol drug by chemometrics and imaging spectroscopy in the near infrared region

    Science.gov (United States)

    Baptistao, Mariana; Rocha, Werickson Fortunato de Carvalho; Poppi, Ronei Jesus

    2011-09-01

    In this work, it was used imaging spectroscopy and chemometric tools for the development and analysis of paracetamol and excipients in pharmaceutical formulations. It was also built concentration maps to study the distribution of the drug in the tablets surface. Multivariate models based on PLS regression were developed for paracetamol and excipients concentrations prediction. For the construction of the models it was used 31 samples in the tablet form containing the active principle in a concentration range of 30.0-90.0% (w/w) and errors below to 5% were obtained for validation samples. Finally, the study of the distribution in the drug was performed through the distribution maps of concentration of active principle and excipients. The analysis of maps showed the complementarity between the active principle and excipients in the tablets. The region with a high concentration of a constituent must have, necessarily, absence or low concentration of the other one. Thus, an alternative method for the paracetamol drug quality monitoring is presented.

  10. Chemometric expertise of the quality of groundwater sources for domestic use.

    Science.gov (United States)

    Spanos, Thomas; Ene, Antoaneta; Simeonova, Pavlina

    2015-01-01

    In the present study 49 representative sites have been selected for the collection of water samples from central water supplies with different geographical locations in the region of Kavala, Northern Greece. Ten physicochemical parameters (pH, electric conductivity, nitrate, chloride, sodium, potassium, total alkalinity, total hardness, bicarbonate and calcium) were analyzed monthly, in the period from January 2010 to December 2010. Chemometric methods were used for monitoring data mining and interpretation (cluster analysis, principal components analysis and source apportioning by principal components regression). The clustering of the chemical indicators delivers two major clusters related to the water hardness and the mineral components (impacted by sea, bedrock and acidity factors). The sampling locations are separated into three major clusters corresponding to the spatial distribution of the sites - coastal, lowland and semi-mountainous. The principal components analysis reveals two latent factors responsible for the data structures, which are also an indication for the sources determining the groundwater quality of the region (conditionally named "mineral" factor and "water hardness" factor). By the apportionment approach it is shown what the contribution is of each of the identified sources to the formation of the total concentration of each one of the chemical parameters. The mean values of the studied physicochemical parameters were found to be within the limits given in the 98/83/EC Directive. The water samples are appropriate for human consumption. The results of this study provide an overview of the hydrogeological profile of water supply system for the studied area.

  11. A comparative chemometric study for water quality expertise of the Athenian water reservoirs.

    Science.gov (United States)

    Farmaki, Eleni G; Thomaidis, Nikolaos S; Simeonov, Vasil; Efstathiou, Constantinos E

    2012-12-01

    The aim of the present study is to compare the application of unsupervised and supervised pattern recognition techniques for the quality assessment and classification of the reservoirs used as the source for the domestic and industrial water supply of the city of Athens, Greece. A new optimization strategy for sampling, monitoring, and water management is proposed. During the period of October 2006 to April 2007, 89 samples were collected from the three water reservoirs (Iliki, Mornos, and Marathon), and 13 parameters (metals and metalloids) were analytically determined. Generally, all the elements were found to fluctuate at very low levels, especially for Mornos that comprises the main water reservoir of Athens. Iliki and Marathon showed relatively elevated values, compared to Mornos, but below the legislative limits. Multivariate unsupervised statistical techniques, such as factor analysis/principal components analysis, and cluster analysis and supervised ones, like discriminant analysis and classification trees, were applied to the data set, and their classification abilities were compared. All the chemometric techniques successfully revealed the critical variables and described the similarities and dissimilarities among the sampling points, emphasizing the individual characteristics in every sample and revealing the sources of elements in the region. New data from posterior samplings (November and December 2007) were used for the validation of the supervised techniques. Finally, water management strategies were proposed concerning the sampling points and representative parameters.

  12. Odontocete Studies Off the Pacific Missile Range Facility in February 2013: Satellite-Tagging, Photo-Identification, and Passive Acoustic Monitoring for Species Verification

    Science.gov (United States)

    2013-12-16

    Megaptera novaeangliae ), calls of which were prevalent during February 2013. M3R System Passive acoustic data pass through the range’s operational signal...densirostris, Mn = Megaptera novaeangliae . 2 One tag did not transmit, thus data available from seven pilot whale tags deployed off Kaua‘i. Table 2...for GIS analyses, Alexandra Vanderzee for help with matching of rough- toothed dolphins, and Amy Van Cise, Morgan Richie, Julie Rivers and Sean Hanser

  13. Monitoring of anaerobic digestion processes: A review perspective

    DEFF Research Database (Denmark)

    Madsen, Michael; Holm-Nielsen, Jens Bo; Esbensen, Kim

    2011-01-01

    to a new level of reliability and effectiveness. It is shown, how proper involvement of process sampling understanding, Theory of Sampling (TOS), constitutes a critical success factor. We survey the more recent trends within the field of AD monitoring and the powerful PAT/TOS/chemometrics application...

  14. Acoustic transducer for acoustic microscopy

    Science.gov (United States)

    Khuri-Yakub, Butrus T.; Chou, Ching H.

    1990-01-01

    A shear acoustic transducer-lens system in which a shear polarized piezoelectric material excites shear polarized waves at one end of a buffer rod having a lens at the other end which excites longitudinal waves in a coupling medium by mode conversion at selected locations on the lens.

  15. Best conditions for biodegradation of diesel oil by chemometric tools

    Directory of Open Access Journals (Sweden)

    Ewa Kaczorek

    2014-01-01

    Full Text Available Diesel oil biodegradation by different bacteria-yeast-rhamnolipids consortia was tested. Chromatographic analysis of post-biodegradation residue was completed with chemometric tools (ANOVA, and a novel ranking procedure based on the sum of ranking differences. These tools were used in the selection of the most effective systems. The best results of aliphatic fractions of diesel oil biodegradation were observed for a yeast consortia with Aeromonas hydrophila KR4. For these systems the positive effect of rhamnolipids on hydrocarbon biodegradation was observed. However, rhamnolipids addition did not always have a positive influence on the biodegradation process (e.g. in case of yeast consortia with Stenotrophomonas maltophila KR7. Moreover, particular differences in the degradation pattern were observed for lower and higher alkanes than in the case with C22. Normally, the best conditions for "lower" alkanes are Aeromonas hydrophila KR4 + emulsifier independently from yeasts and e.g. Pseudomonas stutzeri KR7 for C24 alkane.

  16. Eliminate indeterminacies of independent component analysis for chemometrics

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    An improved method has been proposed to eliminate the indeterminacies of independent component analysis (ICA) for chemomet- rics. Following the arrangement of principal components analysis (PCA), the ICA mixing matrix is selected as signal content indexes, and ICA output are sorted and directed. After many times reputations, independent components (Ics) are paired according to the maximum correlation coefficient, and then the mean values of each IC substitutes the original Ics. This indicates that the ICA inde- terminacies are eliminated. A simulation example is tested to validate this improvement. Finally, a set of experimental LC-MS data is processed without any prior knowledge or specific limitation and the results show that the improved ICA can directly separate the mixed signals in chemometrics, and it is simpler and more reasonable than the simple to use interactive self-modeling mixture analysis (SIMPLISMA).

  17. Chemometrics approach to substrate development, case: semisyntetic cheese

    DEFF Research Database (Denmark)

    Nielsen, Per Væggemose; Hansen, Birgitte Vedel

    1998-01-01

    In several cases a well defined, robust and easy reproducible substrate that meets specific requirements is needed. This is the case in studies of fungal growth and metabolism on specific products as affected by environmental conditions or processing factors, or isolation of product specific fungi...... from food production facilities.The Chemometrics approach to substrate development is illustrated by the development of a semisyntetic cheese substrate. Growth, colour formation and mycotoxin production of 6 cheese related fungi were studied on 9 types of natural cheeses and 24 synthetic cheese...... substrates and compared using principal component analysis (PCA). The synthetic cheese substrates contained various amounts of Ca, K, Mg, Na, P, Fe, Cu, Zn, lactate, lactose and casein. In this manner a robust, well-defined and easy prepared laboratory cheese substrate was developed for Penicillium commune...

  18. Chemometric assessment of enhanced bioremediation of oil contaminated soils

    DEFF Research Database (Denmark)

    Soleimani, Mohsen; Farhoudi, Majid; Christensen, Jan H.

    2013-01-01

    steranes were used for determining the level and type of hydrocarbon contamination. The same methods were used to study oil weathering of 2 to 6 ring polycyclic aromatic compounds (PACs). Results demonstrated that bacterial enrichment and addition of nutrients were most efficient with 50% to 62% removal......Bioremediation is a promising technique for reclamation of oil polluted soils. In this study, six methods for enhancing bioremediation were tested on oil contaminated soils from three refinery areas in Iran (Isfahan, Arak, and Tehran). The methods included bacterial enrichment, planting......, and addition of nitrogen and phosphorous, molasses, hydrogen peroxide, and a surfactant (Tween 80). Total petroleum hydrocarbon (TPH) concentrations and CHEMometric analysis of Selected Ion Chromatograms (SIC) termed CHEMSIC method of petroleum biomarkers including terpanes, regular, diaromatic and triaromatic...

  19. Chemometrics approach to substrate development, case: semisyntetic cheese

    DEFF Research Database (Denmark)

    Nielsen, Per Væggemose; Hansen, Birgitte Vedel

    1998-01-01

    from food production facilities.The Chemometrics approach to substrate development is illustrated by the development of a semisyntetic cheese substrate. Growth, colour formation and mycotoxin production of 6 cheese related fungi were studied on 9 types of natural cheeses and 24 synthetic cheese......, the most frequently occurring contaminant on semi-hard cheese. Growth experiments on the substrate were repeatable and reproducible. The substrate was also suitable for the starter P. camemberti. Mineral elements in cheese were shown to have strong effect on growth, mycotoxin production and colour...... formation of fungi. For P. roqueforti, P. discolor, P. verrucosum and Aspergillus versicolor the substrate was less suitable as a model cheese substrate, which indicates great variation in nutritional demands of the fungi. Substrates suitable for studies of specific cheese types was found for P. roqueforti...

  20. IMMAN: free software for information theory-based chemometric analysis.

    Science.gov (United States)

    Urias, Ricardo W Pino; Barigye, Stephen J; Marrero-Ponce, Yovani; García-Jacas, César R; Valdes-Martiní, José R; Perez-Gimenez, Facundo

    2015-05-01

    The features and theoretical background of a new and free computational program for chemometric analysis denominated IMMAN (acronym for Information theory-based CheMoMetrics ANalysis) are presented. This is multi-platform software developed in the Java programming language, designed with a remarkably user-friendly graphical interface for the computation of a collection of information-theoretic functions adapted for rank-based unsupervised and supervised feature selection tasks. A total of 20 feature selection parameters are presented, with the unsupervised and supervised frameworks represented by 10 approaches in each case. Several information-theoretic parameters traditionally used as molecular descriptors (MDs) are adapted for use as unsupervised rank-based feature selection methods. On the other hand, a generalization scheme for the previously defined differential Shannon's entropy is discussed, as well as the introduction of Jeffreys information measure for supervised feature selection. Moreover, well-known information-theoretic feature selection parameters, such as information gain, gain ratio, and symmetrical uncertainty are incorporated to the IMMAN software ( http://mobiosd-hub.com/imman-soft/ ), following an equal-interval discretization approach. IMMAN offers data pre-processing functionalities, such as missing values processing, dataset partitioning, and browsing. Moreover, single parameter or ensemble (multi-criteria) ranking options are provided. Consequently, this software is suitable for tasks like dimensionality reduction, feature ranking, as well as comparative diversity analysis of data matrices. Simple examples of applications performed with this program are presented. A comparative study between IMMAN and WEKA feature selection tools using the Arcene dataset was performed, demonstrating similar behavior. In addition, it is revealed that the use of IMMAN unsupervised feature selection methods improves the performance of both IMMAN and WEKA

  1. Acoustic dose and acoustic dose-rate.

    Science.gov (United States)

    Duck, Francis

    2009-10-01

    Acoustic dose is defined as the energy deposited by absorption of an acoustic wave per unit mass of the medium supporting the wave. Expressions for acoustic dose and acoustic dose-rate are given for plane-wave conditions, including temporal and frequency dependencies of energy deposition. The relationship between the acoustic dose-rate and the resulting temperature increase is explored, as is the relationship between acoustic dose-rate and radiation force. Energy transfer from the wave to the medium by means of acoustic cavitation is considered, and an approach is proposed in principle that could allow cavitation to be included within the proposed definitions of acoustic dose and acoustic dose-rate.

  2. Semi-automatic long-term acoustic surveying

    DEFF Research Database (Denmark)

    Andreassen, Tórur; Surlykke, Annemarie; Hallam, John

    2014-01-01

    Increasing concern about decline in biodiversity has created a demand for population surveys. Acoustic monitoring is an efficient non-invasive method, which may be deployed for surveys of animals as diverse as insects, birds, and bats. Long-term unmanned automatic monitoring may provide unique...... to determine bat behavior and correct for the bias toward loud bats inherent in acoustic surveying....

  3. Acoustic monitoring of co-seismic changes in gas bubble rupture rate in a hydrothermal reservoir: field evaluation of a possible precursor and mechanism for remote seismic triggering

    Science.gov (United States)

    Crews, J. B.

    2015-12-01

    Remotely triggered seismicity is a phenomenon in which an earthquake at one location triggers others over distances up to thousands of kilometers. The mechanism by which low-amplitude dynamic oscillations of the confining stress can produce such an effect, often after a time delay of minutes-to-days, is unclear, but a concentration of remotely triggered seismic events in carbon-dioxide-rich volcanic and geothermal regions suggests that an increase in pore fluid pressure associated with the nucleation and growth of carbon-dioxide gas bubbles may reduce the effective stress in critically loaded geologic faults. While this hypothesis has been tested in bench-scale laboratory experiments, field detection of seismically initiated gas bubble growth in groundwater may provide further evidence for this remote triggering mechanism. In the present study, a hydrophone continuously records the acoustic power spectrum in CH-10B, a hydrothermal well located in Long Valley Caldera, California - a site that is susceptible to remotely seismic triggering. This well exhibits co-seismic changes in water level in response to near and distant earthquakes, including every magnitude-six or greater at any location on Earth. Exploiting the inverse relationship between gas bubble radius and the peak acoustic frequency emitted when a gas bubble ruptures, this investigation seeks to detect changes in the acoustic power spectrum arising from a shift in the size-distribution or count rate of rupturing gas bubbles, coincident with a distant earthquake. By resolving the timing and intensity of the onset of a change in gas bubble rupture rate after the passage of seismic wave from a distant source, it may be possible to establish the extent to which seismically initiated gas bubble growth contributes to co-seismic borehole water level response, pore fluid pressure perturbations, and the onset of remotely triggered seismicity.

  4. Acoustic Emission Health Monitoring of Fill Purge COPV's Used in Aerospace and Automotive Applications and Designed for Long Cycle Life Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Abstract Problem Description: Cumulative composite damage in composite pressure vessels (CPVs) currently is not monitored on-orbit. Consequently, hazards due to...

  5. Chemometrics quality assessment of wastewater treatment plant effluents using physicochemical parameters and UV absorption measurements.

    Science.gov (United States)

    Platikanov, S; Rodriguez-Mozaz, S; Huerta, B; Barceló, D; Cros, J; Batle, M; Poch, G; Tauler, R

    2014-07-01

    Chemometric techniques like Principal Component Analysis (PCA) and Partial Least Squares Regression (PLS) are used to explore, analyze and model relationships among different water quality parameters in wastewater treatment plants (WWTP). Different data sets generated by laboratory analysis and by an automatic multi-parametric monitoring system with a new designed optical device have been investigated for temporal variations on water quality parameters measured in the water influent and effluent of a WWTP over different time scales. The obtained results allowed the discovery of the more important relationships among the monitored parameters and of their cyclic dependence on time (daily, monthly and annual cycles) and on different plant management procedures. This study intended also the modeling and prediction of concentrations of several water components and parameters, especially relevant for water quality assessment, such as Dissolved Organic Matter (DOM), Total Organic Carbon (TOC) nitrate, detergent, and phenol concentrations. PLS models were built to correlate target concentrations of these constituents with UV spectra measured in samples collected at (1) laboratory conditions (in synthetic water mixtures); and at (2) WWTP conditions (in real water samples from the plant). Using synthetic water mixtures, specific wavelengths were selected with the aim to establish simple and reliable prediction models, which gave good relative predictions with errors of around 3-4% for nitrates, detergent and phenols concentrations and of around 15% for the DOM in external validation. In the case of nitrate and TOC concentrations modeling in real water samples from the effluent of the WWTP using the reduced spectral data set, results were also promising with low prediction errors (less than 20%).

  6. 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...... 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...

  7. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... Back Learn about acoustic neuroma AN Facts What is acoustic neuroma? Diagnosing Symptoms Side Effects Keywords Questions ... kit Treatment Options Overview Observation Radiation Surgery What is acoustic neuroma Diagnosing Symptoms Side effects Question To ...

  8. Recent development status of the quasi real-time crustal deformation monitoring based on the onshore real-time GNSS data and offshore GNSS/Acoustic measurement in Japan

    Science.gov (United States)

    Ohta, Y.; Hino, R.; Kido, M.; Imano, M.; Kawamoto, S.; Sato, Y.; Takahashi, N.

    2015-12-01

    The 2011 Tohoku-Oki earthquake and its associated tsunami clearly showed the need for an accurate tsunami early warning system. Real-time GNSS data have an advantage over the short-time seismograms because robust estimations of location and dimension of coseismic faults can be derived from spatial patterns of permanent coseismic displacement measured by real-time GNSS data. Based on these backgrounds, GSI and Tohoku University has been developed the real-time GNSS analysis system. GSI named this system as REGARD (real-time GEONET Analysis for Rapid Deformation Monitoring), which consists three subsystems: (1) Real-time GPS positioning for all of the GEONET site in every one second, (2) automated extraction of displacement fields due to the large earthquake, and (3) automated estimation of Mw by an approximated single rectangular fault or slip distribution in the assumed plated interface. In contrast, lack of the geodetic observation in the offshore region should cause the resolution degrading of the coseismic fault estimation or coseismic slip distribution. In fact, GNSS/Acoustic (GNSS/A) geodetic measurements have revealed the unexpectedly large extent of the 2011 Tohoku-Oki earthquake rupture near the Japan Trench (e.g., Kido et al. 2011). To reveal the earthquake mechanisms and occurrence, as well as co- and post-seismic behaviours, the observation of seafloor crustal deformation in the offshore region is very important. Thus, we are now developing a continuous horizontal and vertical crustal deformation and tsunami observation system based on the moored buoy by a slack cable. This system measures the horizontal and vertical coseismic displacement just after the large earthquake deduced from GNSS/Acoustic measurement and ocean bottom pressure measurement, respectively (Takahashi et al., 2014, 2015). We will introduce the current development status of the quasi real-time crustal deformation monitoring deduced from these onshore and offshore systems based on the

  9. Acoustic Localization with Infrasonic Signals

    Science.gov (United States)

    Threatt, Arnesha; Elbing, Brian

    2015-11-01

    Numerous geophysical and anthropogenic events emit infrasonic frequencies (wind turbines and tornadoes. These sounds, which cannot be heard by the human ear, can be detected from large distances (in excess of 100 miles) due to low frequency acoustic signals having a very low decay rate in the atmosphere. Thus infrasound could be used for long-range, passive monitoring and detection of these events. An array of microphones separated by known distances can be used to locate a given source, which is known as acoustic localization. However, acoustic localization with infrasound is particularly challenging due to contamination from other signals, sensitivity to wind noise and producing a trusted source for system development. The objective of the current work is to create an infrasonic source using a propane torch wand or a subwoofer and locate the source using multiple infrasonic microphones. This presentation will present preliminary results from various microphone configurations used to locate the source.

  10. Rapid detection of Listeria monocytogenes in milk using confocal micro-Raman spectroscopy and chemometric analysis.

    Science.gov (United States)

    Wang, Junping; Xie, Xinfang; Feng, Jinsong; Chen, Jessica C; Du, Xin-jun; Luo, Jiangzhao; Lu, Xiaonan; Wang, Shuo

    2015-07-02

    Listeria monocytogenes is a facultatively anaerobic, Gram-positive, rod-shape foodborne bacterium causing invasive infection, listeriosis, in susceptible populations. Rapid and high-throughput detection of this pathogen in dairy products is critical as milk and other dairy products have been implicated as food vehicles in several outbreaks. Here we evaluated confocal micro-Raman spectroscopy (785 nm laser) coupled with chemometric analysis to distinguish six closely related Listeria species, including L. monocytogenes, in both liquid media and milk. Raman spectra of different Listeria species and other bacteria (i.e., Staphylococcus aureus, Salmonella enterica and Escherichia coli) were collected to create two independent databases for detection in media and milk, respectively. Unsupervised chemometric models including principal component analysis and hierarchical cluster analysis were applied to differentiate L. monocytogenes from Listeria and other bacteria. To further evaluate the performance and reliability of unsupervised chemometric analyses, supervised chemometrics were performed, including two discriminant analyses (DA) and soft independent modeling of class analogies (SIMCA). By analyzing Raman spectra via two DA-based chemometric models, average identification accuracies of 97.78% and 98.33% for L. monocytogenes in media, and 95.28% and 96.11% in milk were obtained, respectively. SIMCA analysis also resulted in satisfied average classification accuracies (over 93% in both media and milk). This Raman spectroscopic-based detection of L. monocytogenes in media and milk can be finished within a few hours and requires no extensive sample preparation. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Chemometrics-assisted solid-state characterization of pharmaceutically relevant materials. Polymorphic substances.

    Science.gov (United States)

    Calvo, Natalia L; Maggio, Rubén M; Kaufman, Teodoro S

    2017-06-13

    Current regulations command to properly characterize pharmaceutically relevant solid systems. Chemometrics comprise a range of valuable tools, suitable to process large amounts of data and extract valuable information hidden in their structure. This review aims to detail the results of the fruitful association between analytical techniques and chemometrics methods, focusing on those which help to gain insight into the characteristics of drug polymorphism as an important aspect of the solid state of bulk drugs and drug products. Hence, the combination of Raman, terahertz, mid- and near- infrared spectroscopies, as well as instrumental signals resulting from X-ray powder diffraction, (13)C solid state nuclear magnetic resonance spectroscopy and thermal methods with quali-and quantitative chemometrics methodologies are examined. The main issues reviewed, concerning pharmaceutical drug polymorphism, include the use of chemometrics-based approaches to perform polymorph classification and assignment of polymorphic identity, as well as the determination of given polymorphs in simple mixtures and complex systems. Aspects such as the solvation/desolvation of solids, phase transformation, crystallinity and the recrystallization from the amorphous state are also discussed. A brief perspective of the field for the next future is provided, based on the developments of the last decade and the current state of the art of analytical instrumentation and chemometrics methodologies. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Clinical investigation on 22 cases of acoustic neuromas with intraoperative facial nerve function monitoring%听神经瘤术中面神经功能监测22例临床研究

    Institute of Scientific and Technical Information of China (English)

    贺宇波; 吉宏明; 赵建伟; 陈胜利; 张刚利; 李荔荣

    2011-01-01

    目的 探讨术中面神经监测对术后面神经功能保留的影响.方法 使用英国牛津公司Medelec神经生理术中监测仪,对22例听神经瘤术中进行面神经自发面肌电图及电刺激诱发面肌电图监测.结果 通过术中监测自发肌电图结合电刺激诱发肌电图可以精确判断面神经的位置;本组22例大中型听神经瘤,术后6月面神经H-B分级Ⅰ-Ⅱ级13例,Ⅲ级2例,Ⅳ级1例,Ⅴ级1例,Ⅵ级5例.结论 术中肌电图监测可以提示面神经的位置和走行,为手术时避免损伤神经提供依据;肿瘤切除后可帮助确认面神经结构是否完整;全切肿瘤后引出肌电图的最小电刺激强度与面神经预后密切相关.%Objective To explore the influence of intraoperative monitoring on postoperative facial nerve function in acoustic neuroma patients. Methods The facial nerve spontaneous and stimulated electromyography( EMG ) of 22 cases of acoustic neuromas were monitored by Oxford company Medelec intraoperative neurophysiologic monitor. Results The position of facial nerve was correctly located via intraoperative monitoring spontaneous EMG combined with stimulated EMG. According to House-Brackmann facial nerve grading system,the facial nerve was grade I - II in 13 of 22 cases after operation for 6 months,grade Ⅲ in 2 cases,grade Ⅳ in one case,grade Vin one case,and grade VI in 5 cases. Conclusion Intraoprative electromyography( EMG ) could reveal the position of facial nerve and avoid the nerve injury. EMG could help confirm the integrity of the postoperative facial nerve. The minimal stimulated intensity which can derive EMG is related with the prognosis of facial nerve function after total resection of the tumor.

  13. Acoustic behaviors of unsaturated soils

    Science.gov (United States)

    Lu, Z.

    2011-12-01

    Soils are unconsolidated granular materials, consisting of solid particles, water and air. Their mechanical and dynamic behaviors are determined by the discrete nature of the media as well as external and inter-particle forces. For unsaturated soils, two factors significantly affect soils acoustic/seismic responses: external pressure and internal water potential/matric suction. In triaxial cell tests, unsaturated soils were subjected to predefined stress paths to undergo stages of normal consolidation, unload-reload cycles, and failure. The stress deformation curve and stress-P-wave velocity were measured and compared. The study revealed that soil's dynamic response to external pressure are similar to those of the load-deformation behaviors and demonstrated that acoustic velocity can be used to monitor the state of stress of soils. In a long term field soil survey, the P-wave velocities were found to be correlated with water potential as expressed as a power-law relationship. The above phenomena can be understood by using the Terzaghi' s the principle of effective stress. The measured results were in good agreement with Brutsaert theory. The effective stress concept can also be applied to explain the observations in a soil pipe flow study in which soil internal erosion processes were monitored and interpreted by the temporal evolution of the P-wave velocity. In addition to above linear acoustic behaviors, soils, like other earth materials, exhibit astonishing non-classical nonlinear behaviors such as end-point memory, hysteresis, strain -dependent shear modulus, resonant frequency shift, and phase shift, harmonics generation, etc. A nonlinear acoustic study of a soil as a function of water content showed that the nonlinear acoustic parameter are much sensitive to the variations of soil water content than that of the acoustic velocity.

  14. Cyclic Crack Growth Testing of an A.O. Smith Multilayer Pressure Vessel with Modal Acoustic Emission Monitoring and Data Assessment

    Science.gov (United States)

    Ziola, Steven M.

    2014-01-01

    Digital Wave Corp. (DWC) was retained by Jacobs ATOM at NASA Ames Research Center to perform cyclic pressure crack growth sensitivity testing on a multilayer pressure vessel instrumented with DWC's Modal Acoustic Emission (MAE) system, with captured wave analysis to be performed using DWCs WaveExplorerTM software, which has been used at Ames since 2001. The objectives were to document the ability to detect and characterize a known growing crack in such a vessel using only MAE, to establish the sensitivity of the equipment vs. crack size and / or relevance in a realistic field environment, and to obtain fracture toughness materials properties in follow up testing to enable accurate crack growth analysis. This report contains the results of the testing.

  15. Detecting and identifying damage in sandwich polymer composite by using acoustic emission

    DEFF Research Database (Denmark)

    McGugan, M.; Sørensen, Bent F.; Østergaard, R.

    2006-01-01

    Acoustic emission is a useful monitoring tool for extracting extra information during mechanical testing of polymer composite sandwich materials. The study of fracture mechanics within test specimens extracted from wind turbine blade material ispresented. The contribution of the acoustic emission...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-04-15

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

  17. Thermally induced solid-state transformation of cimetidine. A multi-spectroscopic/chemometrics determination of the kinetics of the process and structural elucidation of one of the products as a stable N{sub 3}-enamino tautomer

    Energy Technology Data Exchange (ETDEWEB)

    Calvo, Natalia L.; Simonetti, Sebastian O.; Maggio, Rubén M.; Kaufman, Teodoro S., E-mail: kaufman@iquir-conicet.gov.ar

    2015-05-22

    Highlights: • Thermally stressed cimetidine above its melting point affords a stable N{sub 3} tautomer. • Multi-spectroscopic/chemometric approach developed to monitor tautomerization. • First combined use of NMR, UV and IR spectroscopies with chemometrics. • Solid cimetidine suffers first order degradation upon submission to dry heat. • Theoretical chemistry analysis confirmed the relative stability of cimetidine tautomer. - Abstract: Exposure of cimetidine (CIM) to dry heat (160–180 °C) afforded, upon cooling, a glassy solid containing new and hitherto unknown products. The kinetics of this process was studied by a second order chemometrics-assisted multi-spectroscopic approach. Proton and carbon-13 nuclear magnetic resonance (NMR), as well as ultraviolet and infrared spectroscopic data were jointly used, whereas multivariate curve resolution with alternating least squares (MCR-ALS) was employed as the chemometrics method to extract process information. It was established that drug degradation follows a first order kinetics. One of the products was structurally characterized by mono- and bi-dimensional NMR experiments. It was found to be the N{sub 3}-enamino tautomer (TAU) of CIM, resulting from the thermal isomerization of the double bond of the cyanoguanidine moiety of the drug, from the imine form to its N{sub 3}-enamine state. The thus generated tautomer demonstrated to be stable for months in the glassy solid and in methanolic solutions. A theoretical study of CIM and TAU revealed that the latter is less stable; however, the energy barrier for tautomer interconversion is high enough, precluding the process to proceed rapidly at room temperature.

  18. Discrimination of sugarcane according to cultivar by 1H NMR and chemometric analyses

    Energy Technology Data Exchange (ETDEWEB)

    Alves Filho, Elenilson G.; Silva, Lorena M.A.; Choze, Rafael; Liao, Luciano M. [Laboratorio de Ressonancia Magnetica Nuclear, Instituto de Quimica, Universidade Federal de Goias (UFG), Goiania, GO (Brazil); Honda, Neli K.; Alcantara, Glaucia B. [Departamento de Quimica, Universidade Federal de Mato Grosso do Sul (UFMS), Campo Grande, MS (Brazil)

    2012-07-01

    Several technologies for the development of new sugarcane cultivars have mainly focused on the increase in productivity and greater disease resistance. Sugarcane cultivars are usually identified by the organography of the leaves and stems, the analysis of peroxidase and esterase isoenzyme activities and the total soluble protein as well as soluble solid content. Nuclear magnetic resonance (NMR) associated with chemometric analysis has proven to be a valuable tool for cultivar assessment. Thus, this article describes the potential of chemometric analysis applied to 1H high resolution magic angle spinning (HRMAS) and NMR in solution for the investigation of sugarcane cultivars. For this purpose, leaves from eight different cultivars of sugarcane were investigated by {sup 1}H NMR spectroscopy in combination with chemometric analysis. The approach shows to be a useful tool for the distinction and classification of different sugarcane cultivars as well as to access the differences on its chemical composition. (author)

  19. Chromatography methods and chemometrics for determination of milk fat adulterants

    Science.gov (United States)

    Trbović, D.; Petronijević, R.; Đorđević, V.

    2017-09-01

    Milk and milk-based products are among the leading food categories according to reported cases of food adulteration. Although many authentication problems exist in all areas of the food industry, adequate control methods are required to evaluate the authenticity of milk and milk products in the dairy industry. Moreover, gas chromatography (GC) analysis of triacylglycerols (TAGs) or fatty acid (FA) profiles of milk fat (MF) in combination with multivariate statistical data processing have been used to detect adulterations of milk and dairy products with foreign fats. The adulteration of milk and butter is a major issue for the dairy industry. The major adulterants of MF are vegetable oils (soybean, sunflower, groundnut, coconut, palm and peanut oil) and animal fat (cow tallow and pork lard). Multivariate analysis enables adulterated MF to be distinguished from authentic MF, while taking into account many analytical factors. Various multivariate analysis methods have been proposed to quantitatively detect levels of adulterant non-MFs, with multiple linear regression (MLR) seemingly the most suitable. There is a need for increased use of chemometric data analyses to detect adulterated MF in foods and for their expanded use in routine quality assurance testing.

  20. Chemometrics of differentially expressed proteins from colorectal cancer patients

    Institute of Scientific and Technical Information of China (English)

    Lay-Chin Yeoh; Saravanan Dharmaraj; Boon-Hui Gooi; Manjit Singh; Lay-Harn Gam

    2011-01-01

    AIM: To evaluate the usefulness of differentially expressed proteins from colorectal cancer (CRC) tissues for differentiating cancer and normal tissues. METHODS: A Proteomic approach was used to identify the differentially expressed proteins between CRC and normal tissues. The proteins were extracted using Tris buffer and thiourea lysis buffer (TLB) for extraction of aqueous soluble and membrane-associated proteins, respectively. Chemometrics, namely principal component analysis (PCA) and linear discriminant analysis (LDA), were used to assess the usefulness of these proteins for identifying the cancerous state of tissues. RESULTS: Differentially expressed proteins identified were 37 aqueous soluble proteins in Tris extracts and 24 membrane-associated proteins in TLB extracts. Based on the protein spots intensity on 2D-gel images, PCA by applying an eigenvalue > 1 was successfully used to reduce the number of principal components (PCs) into 12 and seven PCs for Tris and TLB extracts, respectively, and subsequently six PCs, respectively from both the extracts were used for LDA. The LDA classification for Tris extract showed 82.7% of original samples were correctly classified, whereas 82.7% were correctly classified for the cross-validated samples. The LDA for TLB extract showed that 78.8% of original samples and 71.2% of the cross-validated samples were correctly classified. CONCLUSION: The classification of CRC tissues by PCA and LDA provided a promising distinction between normal and cancer types. These methods can possibly be used for identification of potential biomarkers among the differentially expressed proteins identified.

  1. Design of natural food antioxidant ingredients through a chemometric approach.

    Science.gov (United States)

    Mendiola, Jose A; Martín-Alvarez, Pedro J; Señoráns, F Javier; Reglero, Guillermo; Capodicasa, Alessandro; Nazzaro, Filomena; Sada, Alfonso; Cifuentes, Alejandro; Ibáñez, Elena

    2010-01-27

    In the present work, an environmentally friendly extraction process using subcritical conditions has been tested to obtain potential natural food ingredients from natural sources such as plants, fruits, spirulina, propolis, and tuber, with the scope of substituting synthetic antioxidants, which are subject to regulation restrictions and might be harmful for human health. A full characterization has been undertaken from the chemical and biochemical point of view to be able to understand their mechanism of action. Thus, an analytical method for profiling the compounds responsible for the antioxidant activity has been used, allowing the simultaneous determination of water-soluble vitamins, fat-soluble vitamins, phenolic compounds, carotenoids, and chlorophylls in a single run. This information has been integrated and analyzed using a chemometrical approach to correlate the bioactive compounds profile with the antioxidant activity and thus to be able to predict antioxidant activities of complex formulations. As a further step, a simplex centroid mixture design has been tested to find the optimal formulation and to calculate the effect of the interaction among individual extracts in the mixture.

  2. Application of Chemometrics in the Determination of Spirits Authenticity

    Directory of Open Access Journals (Sweden)

    Estrella Patricia Zayas Ruiz

    2013-02-01

    Full Text Available The authenticity of food and food ingredients is a major problem today for the industry and manytechnologies have been applied to detect adulteration and contamination of food. This paper presentsresults of a study conducted at University College Dublin, Ireland, about vodka and whiskey andmixtures thereof, and another study in Cuba, at the Faculty of Chemical Engineering of the HigherPolytechnic Institute «Jose Antonio Echeverria», in collaboration with the Cuban Research Institute ofSugarcane Derivatives (ICIDCA, with historical data of Cuban rums. In the first study three techniqueswere used to determine whether pure drinks could be separated from mixtures: mid-infrared spectroscopywith a Fourier transform and Attenuated Total Reflectance cell, near infrared spectroscopy and ultravioletvisiblespectroscopy. In the second historical determinations of acidity, acetaldehyde, ethyl acetate,methanol, isoamyl alcohol, isobutanol, propanol and ethanol content of different types of Cuban agedrums to establish the possibility to differentiate the aged rum Vigía from the rest of Cuban aged onesby means of that analytic information. Unscramble software was used to apply Chemometrics. PrincipalComponent Analysis and various pretreatments were applied to data acquired experimentally toreduce the dispersion thereof. Near spectroscopy, Ultraviolet visible and Mid-infrared spectroscopyhave potential for the separation of pure whiskey and vodka from mixtures thereof The Cuban agedrums differ from Vigía aged rum successfully with the use of Principal Component Analysis applied tochemical data.

  3. Chemometric approach for prediction of uranium pathways in the soil

    Energy Technology Data Exchange (ETDEWEB)

    Stojanovic, Mirjana; Nihajlovic, Marija; Petrovic, Jelena; Petrovic, Marija; Sostaric, Tanja; Milojkovic, Jelena [Inst. for Technology of Nuclear and Other Mineral Raw Materials, Belgrad (Serbia); Pezo, Lato [Univ. Belgrad (Serbia). Inst. of General and Physical Chemistry

    2014-10-01

    Understanding the effect of soil parameters (pH, Eh and organic and inorganic ligands availability) on uranium mobility under different geochemical conditions is fundamental for reliable prediction of its behaviour and fate in the environment. In this study, the impact of total and available phosphorus content, humus and acidity of Serbian agricultural soils on the content of total and available uranium were evaluated by Response Surface Methodology (RSM), second order polynomial regression models (SOPs) and artificial neural networks (ANNs). The performance of ANNs was compared with the performance of SOPs and experimental results. SOPs showed high coefficients of determination (0.785-0.956), while ANN model performed high prediction accuracy: 0.8893-0.904. According to the results, total and available uranium content in the soil were mostly affected by pH, statistically significant at p < 0.05 level. For the same responses the total phosphorus was found to be also very influential, statistically significant at p < 0.05 and p < 0.10 levels. The impact of available phosphorus and humus was much more influential on total and available uranium content, compared to total phosphorus content. Proposed chemometric approach will be very helpful in preserving the natural resources and practical application for risk assessment modeling of uranium environmental pathways.

  4. Chemometrics applications in biotech processes: assessing process comparability.

    Science.gov (United States)

    Bhushan, Nitish; Hadpe, Sandip; Rathore, Anurag S

    2012-01-01

    A typical biotech process starts with the vial of the cell bank, ends with the final product and has anywhere from 15 to 30 unit operations in series. The total number of process variables (input and output parameters) and other variables (raw materials) can add up to several hundred variables. As the manufacturing process is widely accepted to have significant impact on the quality of the product, the regulatory agencies require an assessment of process comparability across different phases of manufacturing (Phase I vs. Phase II vs. Phase III vs. Commercial) as well as other key activities during product commercialization (process scale-up, technology transfer, and process improvement). However, assessing comparability for a process with such a large number of variables is nontrivial and often companies resort to qualitative comparisons. In this article, we present a quantitative approach for assessing process comparability via use of chemometrics. To our knowledge this is the first time that such an approach has been published for biotech processing. The approach has been applied to an industrial case study involving evaluation of two processes that are being used for commercial manufacturing of a major biosimilar product. It has been demonstrated that the proposed approach is able to successfully identify the unit operations in the two processes that are operating differently. We expect this approach, which can also be applied toward assessing product comparability, to be of great use to both the regulators and the industry which otherwise struggle to assess comparability.

  5. Chemometric evaluation of trace elements in Brazilian medicinal plants

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Paulo S.C. da; Francisconi, Lucilaine S.; Goncalves, Rodolfo D.M.R., E-mail: pscsilva@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro do Reator de Pesquisas

    2013-07-01

    The growing interest in herbal medicines has required standardization in order to ensure their safe use, therapeutic efficacy and quality of the products. Despite the vast flora and the extensive use of medicinal plants by the Brazilian population, scientific studies on the subject are still insufficiency In this study, 59 medicinal plans were analyzed for the determination of As, Ba, Br, Ca, Cl, Cs, Co, Cr, Fe, Hf, K, Mg, Mn, Na, Rb, Sb, Sc, Se, Ta, Th, U, Zn and Zr by neutron activation analysis and Cu, Ni, Pb, Cd and Hg by atomic absorption. The results were analyzed by chemometric methods: correlation analysis, principal component analysis and cluster analysis, in order to verify whether or not there is similarity with respect to their mineral and trace metal contents. Results obtained permitted to classify distinct groups among the analyzed plants and extracts so that these data can be useful in future studies, concerning the therapeutic action the elements here determined may exert. (author)

  6. Chemometric Evaluation of Urinary Steroid Hormone Levels as Potential Biomarkers of Neuroendocrine Tumors

    Directory of Open Access Journals (Sweden)

    Barbara Seroczyńska

    2013-10-01

    Full Text Available Neuroendocrine tumors (NETs are uncommon tumors which can secrete specific hormone products such as peptides, biogenic amines and hormones. So far, the diagnosis of NETs has been difficult because most NET markers are not specific for a given tumor and none of the NET markers can be used to fulfil the criteria of high specificity and high sensitivity for the screening procedure. However, by combining the measurements of different NET markers, they become highly sensitive and specific diagnostic tests. The aim of the work was to identify whether urinary steroid hormones can be identified as potential new biomarkers of NETs, which could be used as prognostic and clinical course monitoring factors. Thus, a rapid and sensitive reversed-phase high-performance liquid chromatographic method (RP-HPLC with UV detection has been developed for the determination of cortisol, cortisone, corticosterone, testosterone, epitestosterone and progesterone in human urine. The method has been validated for accuracy, precision, selectivity, linearity, recovery and stability. The limits of detection and quantification were 0.5 and 1 ng mL−1 for each steroid hormone, respectively. Linearity was confirmed within a range of 1–300 ng mL−1 with a correlation coefficient greater than 0.9995 for all analytes. The described method was successfully applied for the quantification of six endogenous steroid levels in human urine. Studies were performed on 20 healthy volunteers and 19 patients with NETs. Next, for better understanding of tumor biology in NETs and for checking whether steroid hormones can be used as potential biomarkers of NETs, a chemometric analysis of urinary steroid hormone levels in both data sets was performed.

  7. Chemometric evaluation of urinary steroid hormone levels as potential biomarkers of neuroendocrine tumors.

    Science.gov (United States)

    Plenis, Alina; Miękus, Natalia; Olędzka, Ilona; Bączek, Tomasz; Lewczuk, Anna; Woźniak, Zofia; Koszałka, Patrycja; Seroczyńska, Barbara; Skokowski, Jarosław

    2013-10-16

    Neuroendocrine tumors (NETs) are uncommon tumors which can secrete specific hormone products such as peptides, biogenic amines and hormones. So far, the diagnosis of NETs has been difficult because most NET markers are not specific for a given tumor and none of the NET markers can be used to fulfil the criteria of high specificity and high sensitivity for the screening procedure. However, by combining the measurements of different NET markers, they become highly sensitive and specific diagnostic tests. The aim of the work was to identify whether urinary steroid hormones can be identified as potential new biomarkers of NETs, which could be used as prognostic and clinical course monitoring factors. Thus, a rapid and sensitive reversed-phase high-performance liquid chromatographic method (RP-HPLC) with UV detection has been developed for the determination of cortisol, cortisone, corticosterone, testosterone, epitestosterone and progesterone in human urine. The method has been validated for accuracy, precision, selectivity, linearity, recovery and stability. The limits of detection and quantification were 0.5 and 1 ng mL-1 for each steroid hormone, respectively. Linearity was confirmed within a range of 1-300 ng mL-1 with a correlation coefficient greater than 0.9995 for all analytes. The described method was successfully applied for the quantification of six endogenous steroid levels in human urine. Studies were performed on 20 healthy volunteers and 19 patients with NETs. Next, for better understanding of tumor biology in NETs and for checking whether steroid hormones can be used as potential biomarkers of NETs, a chemometric analysis of urinary steroid hormone levels in both data sets was performed.

  8. Analysis of chicken fat as adulterant in butter using fourier transform infrared spectroscopy and chemometrics

    Directory of Open Access Journals (Sweden)

    Nurrulhidayah, A. F.

    2013-09-01

    Full Text Available Butter may be adulterated with cheaper animal fats, such as chicken fat (CF. Thus, the detection and quantification of butter adulteration with CF was monitored using Fourier transform infrared (FTIR spectroscopy, combined with chemometric of partial least square (PLS at the frequency regions of 1200-1000cm–1. FTIR measurements were made on pure butter and that adulterated with varying concentrations of CF (0-100% w/w in butter. PLS calibration exhibits a good relationship between actual and FTIR predicted values of CF with a coefficient of determination (R2 of 0.981. The root means standard error of calibration (RMSEC and during cross validation (RMSECV obtained using six principal components (PCs are 2.08 and 4.33% v/v, respectively.La mantequilla puede ser adulterada con grasas animales más baratas, como la grasa de pollo (GP. Así, la detección y cuantificación de la adulteración de mantequilla con GP se controló usando transformada de Fourier infrarroja (FTIR, combinada con técnicas quimiométricas de mínimos cuadrados parciales (PLS en las regiones de frecuencia de 1200-1000cm–1. Las medidas FTIR se realizaron sobre la mantequilla pura y adulterada con diferentes concentraciones de GP (0-100% w/w en la mantequilla. La calibración de PLS presenta una buena relación entre los valores reales y los valores pronosticados de FTIR de la GP con un coeficiente de determinación (R2 de 0.981. La raíz del error estándar de calibración (RMSEC durante la validación cruzada (RMSECV obtenido utilizando seis componentes principales (PC fueron 2,08 y 4,33% v/v, respectivamente.

  9. 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.

  10. 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...

  11. Acoustic cryocooler

    Science.gov (United States)

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

    1990-01-01

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

  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. Authenticity study of Phyllanthus species by NMR and FT-IR techniques coupled with chemometric methods

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Maiara S.; Pereira-Filho, Edenir R.; Ferreira, Antonio G. [Universidade Federal de Sao Carlos (UFSCAR), SP (Brazil). Dept. de Quimica; Boffo, Elisangela F. [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Inst. de Quimica; Figueira, Glyn M., E-mail: maiarassantos@yahoo.com.br [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Centro Pluridisciplinar de Pesquisas Quimicas, Biologicas e Agricolas

    2012-07-01

    The importance of medicinal plants and their use in industrial applications is increasing worldwide, especially in Brazil. Phyllanthus species, popularly known as 'quebra-pedras' in Brazil, are used in folk medicine for treating urinary infections and renal calculus. This paper reports an authenticity study, based on herbal drugs from Phyllanthus species, involving commercial and authentic samples using spectroscopic techniques: FT-IR, {sup 1}H HR-MAS NMR and {sup 1}H NMR in solution, combined with chemometric analysis. The spectroscopic techniques evaluated, coupled with chemometric methods, have great potential in the investigation of complex matrices. Furthermore, several metabolites were identified by the NMR techniques. (author)

  14. Authenticity study of Phyllanthus species by NMR and FT-IR Techniques coupled with chemometric methods

    Directory of Open Access Journals (Sweden)

    Maiara S. Santos

    2012-01-01

    Full Text Available The importance of medicinal plants and their use in industrial applications is increasing worldwide, especially in Brazil. Phyllanthus species, popularly known as "quebra-pedras" in Brazil, are used in folk medicine for treating urinary infections and renal calculus. This paper reports an authenticity study, based on herbal drugs from Phyllanthus species, involving commercial and authentic samples using spectroscopic techniques: FT-IR, ¹H HR-MAS NMR and ¹H NMR in solution, combined with chemometric analysis. The spectroscopic techniques evaluated, coupled with chemometric methods, have great potential in the investigation of complex matrices. Furthermore, several metabolites were identified by the NMR techniques.

  15. Grape juice quality control by means of ¹H nmr spectroscopy and chemometric analyses

    Directory of Open Access Journals (Sweden)

    Caroline Werner Pereira da Silva Grandizoli

    2014-01-01

    Full Text Available This work shows the application of ¹H NMR spectroscopy and chemometrics for quality control of grape juice. A wide range of quality assurance parameters were assessed by single ¹H NMR experiments acquired directly from juice. The investigation revealed that conditions and time of storage should be revised and indicated on all labels. The sterilization process of homemade grape juices was efficient, making it possible to store them for long periods without additives. Furthermore, chemometric analysis classified the best commercial grape juices to be similar to homemade grape juices, indicating that this approach can be used to determine the authenticity after adulteration.

  16. Attempt to separate the fluorescence spectra of adrenaline and noradrenaline using chemometrics

    DEFF Research Database (Denmark)

    Nikolajsen, Rikke P; Hansen, Åse Marie; Bro, R

    2000-01-01

    An investigation was conducted on whether the fluorescence spectra of the very similar catecholamines adrenaline and noradrenaline could be separated using chemometric methods. The fluorescence landscapes (several excitation and emission spectra were measured) of two data sets with respectively 16...... regression (Unfold-PLSR) on the larger data set and parallel factor analysis (PARAFAC) of the six samples of the smaller set showed that there was no difference between the fluorescence landscapes of adrenaline and noradrenaline. It can be concluded that chemometric separation of adrenaline and noradrenaline...

  17. 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.

  18. 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

  19. Sonification of acoustic emission data

    Science.gov (United States)

    Raith, Manuel; Große, Christian

    2014-05-01

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

  20. Evaluation of damage accumulation behavior and strength anisotropy of NITE SiC/SiC composites by acoustic emission, digital image correlation and electrical resistivity monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Nozawa, Takashi, E-mail: nozawa.takashi67@jaea.go.jp [Japan Atomic Energy Agency, Rokkasho, Aomori (Japan); Ozawa, Kazumi [Japan Atomic Energy Agency, Rokkasho, Aomori (Japan); Asakura, Yuuki; Kohyama, Akira [Muroran Institute of Technology, Muroran, Hokkaido (Japan); Tanigawa, Hiroyasu [Japan Atomic Energy Agency, Rokkasho, Aomori (Japan)

    2014-12-15

    Understanding the cracking process of the composites is essential to establish the design basis for practical applications. This study aims to investigate the damage accumulation process and its anisotropy for nano-infiltration transient eutectic sintered (NITE) SiC/SiC composites by various characterization techniques such as the acoustic emission (AE), digital image correlation (DIC) and electrical resistivity (ER) measurements. Cracking behavior below the proportional limit stress (PLS) was specifically addressed. Similar to the other generic SiC/SiC composites, the 1st AE event was identified below the PLS for NITE SiC/SiC composites with a dependency of fabric orientation. The DIC results support that the primary failure mode depending on fiber orientation affected more than the other minor modes did. Detailed AE waveform analysis by wavelet shows a potential to classify the failure behavior depending on architecture. Cracking below the PLS is a potential concern in component deign but the preliminary ER measurements imply that the impact of cracking below the PLS on composite function was limited.

  1. Love Acoustic Wave-Based Devices and Molecularly-Imprinted Polymers as Versatile Sensors for Electronic Nose or Tongue for Cancer Monitoring

    Directory of Open Access Journals (Sweden)

    Corinne Dejous

    2016-06-01

    Full Text Available Cancer is a leading cause of death worldwide and actual analytical techniques are restrictive in detecting it. Thus, there is still a challenge, as well as a need, for the development of quantitative non-invasive tools for the diagnosis of cancers and the follow-up care of patients. We introduce first the overall interest of electronic nose or tongue for such application of microsensors arrays with data processing in complex media, either gas (e.g., Volatile Organic Compounds or VOCs as biomarkers in breath or liquid (e.g., modified nucleosides as urinary biomarkers. Then this is illustrated with a versatile acoustic wave transducer, functionalized with molecularly-imprinted polymers (MIP synthesized for adenosine-5′-monophosphate (AMP as a model for nucleosides. The device including the thin film coating is described, then static measurements with scanning electron microscopy (SEM and electrical characterization after each step of the sensitive MIP process (deposit, removal of AMP template, capture of AMP target demonstrate the thin film functionality. Dynamic measurements with a microfluidic setup and four targets are presented afterwards. They show a sensitivity of 5 Hz·ppm−1 of the non-optimized microsensor for AMP detection, with a specificity of three times compared to PMPA, and almost nil sensitivity to 3′AMP and CMP, in accordance with previously published results on bulk MIP.

  2. Love Acoustic Wave-Based Devices and Molecularly-Imprinted Polymers as Versatile Sensors for Electronic Nose or Tongue for Cancer Monitoring.

    Science.gov (United States)

    Dejous, Corinne; Hallil, Hamida; Raimbault, Vincent; Lachaud, Jean-Luc; Plano, Bernard; Delépée, Raphaël; Favetta, Patrick; Agrofoglio, Luigi; Rebière, Dominique

    2016-06-20

    Cancer is a leading cause of death worldwide and actual analytical techniques are restrictive in detecting it. Thus, there is still a challenge, as well as a need, for the development of quantitative non-invasive tools for the diagnosis of cancers and the follow-up care of patients. We introduce first the overall interest of electronic nose or tongue for such application of microsensors arrays with data processing in complex media, either gas (e.g., Volatile Organic Compounds or VOCs as biomarkers in breath) or liquid (e.g., modified nucleosides as urinary biomarkers). Then this is illustrated with a versatile acoustic wave transducer, functionalized with molecularly-imprinted polymers (MIP) synthesized for adenosine-5'-monophosphate (AMP) as a model for nucleosides. The device including the thin film coating is described, then static measurements with scanning electron microscopy (SEM) and electrical characterization after each step of the sensitive MIP process (deposit, removal of AMP template, capture of AMP target) demonstrate the thin film functionality. Dynamic measurements with a microfluidic setup and four targets are presented afterwards. They show a sensitivity of 5 Hz·ppm(-1) of the non-optimized microsensor for AMP detection, with a specificity of three times compared to PMPA, and almost nil sensitivity to 3'AMP and CMP, in accordance with previously published results on bulk MIP.

  3. Uncertainty analysis in acoustic investigations

    OpenAIRE

    2013-01-01

    The problem of uncertainty assessment in acoustic investigations is presented in the hereby paper. The aspect of the uncertainty asymmetry in processing of data obtained in the measuring test of sound levels, determined in decibels, was sketched. On the basis of the analysis of data obtained in the continuous monitoring of road traffic noise in Krakow typical probability distributions for a day, evening and night were determined. The method of the uncertainty assessment based on the propagati...

  4. Use of acoustic technology to monitor the time course of Rhynchophorus ferrugineus larval mortality in date palms after treatments with Beauveria bassiana

    Science.gov (United States)

    Spectral and temporal patterns of insect sound impulses were monitored daily for 23-d periods in 8, 10, or 5 small date palm trees containing larvae dipped in 0 (control), 104 (low), or 108 (high) conidia/ml doses of entomopathogenic fungus, Beauveria bassiana (Bb 203), respectively. Each tree conta...

  5. Damage Monitoring for Full-Scale Aircraft Statics Test Based on Acoustic Emission%基于声发射的全尺寸飞机静强度损伤监测

    Institute of Scientific and Technical Information of China (English)

    韩晖; 宁宁; 肖迎春; 刘国强; 李明

    2015-01-01

    More applications of Acoustic Emission (AE)have been implemented in structure health monitoring of aircraft.In this paper,the development and orientation principium of AE were introduced,then damage monitoring during static test of a full-scale aircraft was carried out.Through analyzing the parameters of AE,structural damage in some area was caught.The result shows that AE has advantages in damage monitoring for full-scale aircraft static test,it could avoid severe structural damages for expensive aircraft during statics test,and provide reference for damage tolerance design of airplanes.%声发射技术在飞机结构无损检测中的运用日益广泛,对声发射技术的发展现状、定位原理进行了介绍,并运用声发射技术完成了某型机全尺寸静强度试验的损伤监测。通过对采集的幅度、能量等信号参数进行分析,及时发现了飞机某部位结构的损伤。结果表明,声发射技术在飞机静强度试验损伤监测中可及时捕捉裂纹的形成和扩展过程,对发现金属结构损伤具有一定优势,可避免造价高昂的飞机在试验过程中发生大的结构性破坏,从而为飞机结构的损伤容限设计提供参考。

  6. Application of neurophysiological monitoring and microsurgical technique in acoustic neurinoma resection%神经电生理监测技术和显微外科技术在听神经瘤手术中应用

    Institute of Scientific and Technical Information of China (English)

    牛朝诗; 凌士营; 计颖; 丁宛海; 姜晓峰; 刘会林; 陈海宁; 魏祥品; 傅先明

    2010-01-01

    目的 研究神经电生理监测技术和显微外科技术联合应用在听神经瘤切除中的作用,探讨对面听神经功能的保护作用.方法 听神经瘤113例,经枕下,乙状窦后入路显微外科切除肿瘤,术中进行脑神经肌电图、脑干听觉诱发电位监测,并在术末行面神经电刺激判断面神经的保留情况,经随访评价术后面神经功能情况.结果 在电生理监测下经枕下,乙状窦后入路显微切除113例听神经瘤,肿瘤全切除102例(90.3%),次全切除6例(5.3%),大部切除5例(4.4%).术后1周至出院前,根据House-Brackman面神经功能分级对面神经功能进行评估:Ⅰ、Ⅱ级86例(76.1%),Ⅲ、Ⅳ级12例(10.6%),Ⅴ、Ⅵ级15例(13.3%).面神经解剖保留98例(86.7%).听神经解剖保留40例(35.4%).同时,当术末电刺激小于或等于4 mA时预示术后面听神经功能恢复尚可.结论 神经电生理监测辅助应用于听神经瘤显微外科手术中可提高肿瘤全切除率以及面神经解剖保留率和功能保留率.同时,术末电刺激可为术后神经功能恢复进行预后评估.%Objective To investigate the application of neurophysiological monitoring and microsurgi-eal technique in acoustic neurinoma resection, exploring the significance of neurophysiological monitoring in facial and auditory nerve reservation of acoustic neuronma microsurgery. Methods Accompanied with EMG and BAEP nerve monitoring, 113 patients harboring acoustic neuroma were treated surgically by the subocipi-tal retrosigmoid approach for reserving facial and auditory nerve. The facial nerve was stimulated to evaluate its function during late-operation. Postoperative facial and auditory nerve function were valuated in all the postop-erative following up. Results All of them were treated microsurgically via the suboccipitai retrosigmoid ap-proach. Total tumors resection was achieved in 102 cases (90.3%), subtotal resection in 6 cases(5.3%) and partial resection in 5 case (4

  7. Prototype Repository. Acoustic emission and ultrasonic monitoring results from deposition hole DA3545G01 in the Prototype. Repository between April 2007 and September 2007

    Energy Technology Data Exchange (ETDEWEB)

    Zolezzi, F.; Haycox, J.R.; Pettitt, W.S. (Applied Seismology Consultants, Shrewsbury (United Kingdom))

    2008-07-01

    This six-month period of ultrasonic monitoring in the Prototype Repository Experiment, has been undertaken with the following objectives; - Produce accurate source locations for AEs so as to delineate the spatial and temporal extent of any brittle microcracking within the rock mass around the deposition hole and locate any movements on pre-existing macroscopic fractures; - Conduct regular ultrasonic surveys to assess the effect of heating and other environmental changes on the velocity and amplitude of transmitted ultrasonic waves; - Investigate changes in dynamic moduli and crack density to show how the properties of the rock volume around the deposition hole change through the experiment; - Relate the AE and ultrasonic measurements to the measured in situ stress regime and other operating parameters such as temperature and fluid pressure; - Outline how the results from this reporting period relate to previous monitoring periods, and into the overall experimental aims and objectives.

  8. Prototype Repository. Acoustic emission and ultrasonic monitoring results from deposition hole DA3545G01 in the Prototype. Repository between April 2007 and September 2007

    Energy Technology Data Exchange (ETDEWEB)

    Zolezzi, F.; Haycox, J.R.; Pettitt, W.S. (Applied Seismology Consultants, Shrewsbury (United Kingdom))

    2008-07-01

    This six-month period of ultrasonic monitoring in the Prototype Repository Experiment, has been undertaken with the following objectives; - Produce accurate source locations for AEs so as to delineate the spatial and temporal extent of any brittle microcracking within the rock mass around the deposition hole and locate any movements on pre-existing macroscopic fractures; - Conduct regular ultrasonic surveys to assess the effect of heating and other environmental changes on the velocity and amplitude of transmitted ultrasonic waves; - Investigate changes in dynamic moduli and crack density to show how the properties of the rock volume around the deposition hole change through the experiment; - Relate the AE and ultrasonic measurements to the measured in situ stress regime and other operating parameters such as temperature and fluid pressure; - Outline how the results from this reporting period relate to previous monitoring periods, and into the overall experimental aims and objectives.

  9. Diel patterns and temporal trends in spawning activities of Robust Redhorse and River Redhorse in Georgia, assessed using passive acoustic monitoring

    Science.gov (United States)

    Straight, Carrie A.; Jackson, C. Rhett; Freeman, Byron J.; Freeman, Mary C.

    2015-01-01

    The conservation of imperiled species depends upon understanding threats to the species at each stage of its life history. In the case of many imperiled migratory fishes, understanding how timing and environmental influences affect reproductive behavior could provide managers with information critical for species conservation. We used passive acoustic recorders to document spawning activities for two large-bodied catostomids (Robust Redhorse Moxostoma robustum in the Savannah and Broad rivers, Georgia, and River Redhorse M. carinatum in the Coosawattee River, Georgia) in relation to time of day, water temperature, discharge variation, moonlight, and weather. Robust Redhorse spawning activities in the Savannah and Broad rivers were more frequent at night or in the early morning (0100–0400 hours and 0800–1000 hours, respectively) and less frequent near midday (1300 hours). Spawning attempts in the Savannah and Broad rivers increased over a 3–4-d period and then declined. River Redhorse spawning activities in the Coosawattee River peaked on the first day of recording and declined over four subsequent days; diel patterns were less discernible, although moon illumination was positively associated with spawning rates, which was also observed for Robust Redhorses in the Savannah River. Spawning activity in the Savannah and Broad rivers was negatively associated with water temperature, and spawning activity increased in association with cloud cover in the Savannah River. A large variation in discharge was only measured in the flow-regulated Savannah River and was not associated with spawning attempts. To our knowledge, this is the first study to show diel and multiday patterns in spawning activities for anyMoxostoma species. These patterns and relationships between the environment and spawning activities could provide important information for the management of these species downstream of hydropower facilities.

  10. 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...

  11. 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....

  12. [Discrimination of donkey meat by NIR and chemometrics].

    Science.gov (United States)

    Niu, Xiao-Ying; Shao, Li-Min; Dong, Fang; Zhao, Zhi-Lei; Zhu, Yan

    2014-10-01

    Donkey meat samples (n = 167) from different parts of donkey body (neck, costalia, rump, and tendon), beef (n = 47), pork (n = 51) and mutton (n = 32) samples were used to establish near-infrared reflectance spectroscopy (NIR) classification models in the spectra range of 4,000~12,500 cm(-1). The accuracies of classification models constructed by Mahalanobis distances analysis, soft independent modeling of class analogy (SIMCA) and least squares-support vector machine (LS-SVM), respectively combined with pretreatment of Savitzky-Golay smooth (5, 15 and 25 points) and derivative (first and second), multiplicative scatter correction and standard normal variate, were compared. The optimal models for intact samples were obtained by Mahalanobis distances analysis with the first 11 principal components (PCs) from original spectra as inputs and by LS-SVM with the first 6 PCs as inputs, and correctly classified 100% of calibration set and 98. 96% of prediction set. For minced samples of 7 mm diameter the optimal result was attained by LS-SVM with the first 5 PCs from original spectra as inputs, which gained an accuracy of 100% for calibration and 97.53% for prediction. For minced diameter of 5 mm SIMCA model with the first 8 PCs from original spectra as inputs correctly classified 100% of calibration and prediction. And for minced diameter of 3 mm Mahalanobis distances analysis and SIMCA models both achieved 100% accuracy for calibration and prediction respectively with the first 7 and 9 PCs from original spectra as inputs. And in these models, donkey meat samples were all correctly classified with 100% either in calibration or prediction. The results show that it is feasible that NIR with chemometrics methods is used to discriminate donkey meat from the else meat.

  13. Chemometric interpretation of heavy metal patterns in soils worldwide.

    Science.gov (United States)

    Skrbić, Biljana; Durisić-Mladenović, Natasa

    2010-09-01

    Principal component analysis (PCA) was applied on data sets containing levels of six heavy metals (Pb, Cu, Zn, Cd, Ni, Cr) in soils from different parts of the world in order to investigate the information captured in the global heavy metal patterns. Data used in this study consisted of the heavy metal contents determined in 23 soil samples from and around the Novi Sad city area in the Vojvodina Province, northern part of Serbia, together with those from the city of Banja Luka, the second largest city in Bosnia and Herzegovina, and the ones reported previously in the relevant literature in order to evaluate heavy metal distribution pattern in soils of different land-use types, as well as spatial and temporal differences in the patterns. The chemometric analysis was applied on the following input data sets: the overall set with all data gathered in this study containing 264 samples, and two sub sets obtained after dividing the overall set in accordance to the soil metal index, SMI, calculated here, i.e. the set of unpolluted soils having SMIs100%. Additionally, univariate descriptive statistics and the Spearman's non-parametric rank correlation coefficients were calculated for these three sets. A Box-Cox transformation was used as a data pretreatment before the statistical methods applied. According to the results, it was seen that anthropogenic and background sources had different impact on the data variability in the case of polluted and unpolluted soils. The sample discrimination regarding the land-use types was more evident for the unpolluted soils than for the polluted ones. Using linear discriminant analysis, content of Cu was determined as a variable with a major discriminant capacity. The correct classification of 73.3% was achieved for predefined land-use types. Classification of the samples in accordance to the pollution level expressed as SMI was necessary in order to avoid the "masking" effect of the polluted soil patterns over the non-polluted ones.

  14. 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.

  15. 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.

  16. 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.

  17. Chemometric study of the sinter mixtures used in sinter plants in Poland

    Directory of Open Access Journals (Sweden)

    A. Smoliński

    2015-01-01

    Full Text Available The main goal of the study was the analysis of chemical parameters of sinter mixtures used in sinter plants in Poland. For this purpose the chemometric method was used, in this case hierarchical clustering analysis. This method allowed to examine the similarities and differences between the studied sinter mixtures.

  18. Simultaneous spectrophotometric determination of paracetamol, ibuprofen and caffeine in pharmaceuticals by chemometric methods

    Science.gov (United States)

    Khoshayand, M. R.; Abdollahi, H.; Shariatpanahi, M.; Saadatfard, A.; Mohammadi, A.

    2008-08-01

    In this study, the simultaneous determination of paracetamol, ibuprofen and caffeine in pharmaceuticals by chemometric approaches using UV spectrophotometry has been reported as a simple alternative to using separate models for each component. Spectra of paracetamol, ibuprofen and caffeine were recorded at several concentrations within their linear ranges and were used to compute the calibration mixture between wavelengths 200 and 400 nm at an interval of 1 nm in methanol:0.1 HCl (3:1). Partial least squares regression (PLS), genetic algorithm coupled with PLS (GA-PLS), and principal component-artificial neural network (PC-ANN) were used for chemometric analysis of data and the parameters of the chemometric procedures were optimized. The analytical performances of these chemometric methods were characterized by relative prediction errors and recoveries (%) and were compared with each other. The GA-PLS shows superiority over other applied multivariate methods due to the wavelength selection in PLS calibration using a genetic algorithm without loss of prediction capacity. Although the components show an important degree of spectral overlap, they have been determined simultaneously and rapidly requiring no separation step. These three methods were successfully applied to pharmaceutical formulation, capsule, with no interference from excipients as indicated by the recovery study results. The proposed methods are simple and rapid and can be easily used in the quality control of drugs as alternative analysis tools.

  19. Chemometric modelling based on 2D-fluorescence spectra without a calibration measurement.

    Science.gov (United States)

    Solle, D; Geissler, D; Stärk, E; Scheper, T; Hitzmann, B

    2003-01-22

    2D fluorescence spectra provide information from intracellular compounds. Fluorophores like trytophan, tyrosine and phenylalanin as well as NADH and flavins make the corresponding measurement systems very important for bioprocess supervision and control. The evaluation is usually based on chemometric modelling using for their calibration procedure off-line measurements of the desired process variables. Due to the data driven approach lots of off-line measurements are required. Here a methodology is presented, which enables to perform a calibration procedure of chemometric models without any further measurement. The necessary information for the calibration procedure is provided by means of the a priori knowledge about the process, i.e. a mathematical model, whose model parameters are estimated during the calibration procedure, as well as the fact that the substrate should be consumed at the end of the process run. The new methodology for chemometric calibration is applied for a batch cultivation of aerobically grown S. cerevisiae on the glucose Schatzmann medium. As will be presented the chemometric models, which are determined by this method, can be used for prediction during new process runs. The MATHLAB routine is free available on request from the authors.

  20. Provenance of pottery determined by soil physicochemical and chemometric methods: A case study from Frederiksgave, Ghana

    DEFF Research Database (Denmark)

    Rasmussen, Lars Holm; Bredwa-Mensah, Y.; Borggaard, Ole K.;

    2009-01-01

    The suitability of using traditional soil chemical and mineralogical methods combined with chemometrics to trace provenance of archaeological samples was tested on potsherds from Frederiksgave, a former Danish plantation in southern Ghana, in use from 18301850. Soil and six potsherds from Frederi...

  1. Experimental Design, Near-Infrared Spectroscopy, and Multivariate Calibration: An Advanced Project in a Chemometrics Course

    Science.gov (United States)

    de Oliveira, Rodrigo R.; das Neves, Luiz S.; de Lima, Kassio M. G.

    2012-01-01

    A chemometrics course is offered to students in their fifth semester of the chemistry undergraduate program that includes an in-depth project. Students carry out the project over five weeks (three 8-h sessions per week) and conduct it in parallel to other courses or other practical work. The students conduct a literature search, carry out…

  2. [Application of chemometrics in composition-activity relationship research of traditional Chinese medicine].

    Science.gov (United States)

    Han, Sheng-Nan

    2014-07-01

    Chemometrics is a new branch of chemistry which is widely applied to various fields of analytical chemistry. Chemometrics can use theories and methods of mathematics, statistics, computer science and other related disciplines to optimize the chemical measurement process and maximize access to acquire chemical information and other information on material systems by analyzing chemical measurement data. In recent years, traditional Chinese medicine has attracted widespread attention. In the research of traditional Chinese medicine, it has been a key problem that how to interpret the relationship between various chemical components and its efficacy, which seriously restricts the modernization of Chinese medicine. As chemometrics brings the multivariate analysis methods into the chemical research, it has been applied as an effective research tool in the composition-activity relationship research of Chinese medicine. This article reviews the applications of chemometrics methods in the composition-activity relationship research in recent years. The applications of multivariate statistical analysis methods (such as regression analysis, correlation analysis, principal component analysis, etc. ) and artificial neural network (such as back propagation artificial neural network, radical basis function neural network, support vector machine, etc. ) are summarized, including the brief fundamental principles, the research contents and the advantages and disadvantages. Finally, the existing main problems and prospects of its future researches are proposed.

  3. Experimental Design, Near-Infrared Spectroscopy, and Multivariate Calibration: An Advanced Project in a Chemometrics Course

    Science.gov (United States)

    de Oliveira, Rodrigo R.; das Neves, Luiz S.; de Lima, Kassio M. G.

    2012-01-01

    A chemometrics course is offered to students in their fifth semester of the chemistry undergraduate program that includes an in-depth project. Students carry out the project over five weeks (three 8-h sessions per week) and conduct it in parallel to other courses or other practical work. The students conduct a literature search, carry out…

  4. Monitoring and characterization of yeasts behavior under fermentation processes using technometric approaches

    OpenAIRE

    2013-01-01

    Tese de doutoramento em Chemical and Biological Engineering Technometrics concerns on the development and use of statistical methods in different fields, such as biotechnological processes, in order to understand their multivariate and multidimensional complexity. Chemical changes occurring within these processes can be monitored using chemometric tools that combined with bioinformatic methodologies, can provide an enlarged overview of the process, enabling the unbiased study ...

  5. Acoustic source for generating an acoustic beam

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-05-31

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

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

    Science.gov (United States)

    Shen, Jian Qi

    2016-08-01

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

  7. Acoustic emission monitoring in Cooke 4 gold mine in South Africa -summary of the main findings of a 5-year SATREPS project-

    Science.gov (United States)

    Naoi, M.; Nakatani, M.; Moriya, H.; Otsuki, K.; Kgarume, T.; Philipp, J.; Murakami, O.; Masakale, T.; Ribeiro, L.; Yabe, Y.; Kawakata, H.; Ward, A.; Durrheim, R.; Ogasawara, H.

    2015-12-01

    We deployed a network targeting acoustic emissions (AEs) down to Mw~ -5 at 1-km depth in the Cooke 4 mine in South Africa as a part of a 5-year project called "Observational Studies in South African Mines to Mitigate Seismic Risks." This network of 30 sensors spans ~100 m, and collected waveform data for more than 4.5-million triggers in 5 years. We provide an overview of the main findings. 1) Naoi et al. (2015; Pageoph) reported that 90% of observed AEs aggregated along the advancing mining front. Their size distribution obeyed the Gutenberg-Richter law down to Mw -4, and their b-values were invariant with time from blasting, contradicting a previous study. 2) Moriya et al. (under review) showed that this AE aggregation consists of several tabular clusters, which were formed regularly as the mining front advanced. Although large earthquakes (Mw > 1) were not found, the clusters likely represent the preparation process of large shear fracture events because their geometry resembles large shear fractures, known by in-situ wall-rock observation, which formed concurrently with large seismic events. 3) Naoi et al. (2015; Tectonophysics) reported that the remaining 10% of AEs exhibit very sharp, planar distributions, with high b-values. They are likely events located on pre-existing geological faults loaded by mining-induced stresses. Such on-fault events are rare for intraplate faults, where microseismic events generally occur in the surrounding region. 4) Naoi et al. (2015; JGR) found planar clusters that newly emerged ahead of a mining front and gradually expanded to 20 m. They likely represent the evolution of a slow-slip patch on a pre-existing fault. The b-value of those AEs decreased drastically from 2.5 to 1.5, consistent with stress buildup by the approaching mining front. This project is supported by JST/JICA, SATREPS, JSPS KAKENHI Grant Numbers 21224012, 21246134, 26249137, 26887022, and MEXT's Earthquake and Volcano Hazards Observation and Research Program.

  8. Defining of the 2-D surface of the anomaly stressed magnetic hierarchical object located in the layered blocked geological medium using the data of acoustic and electromagnetic monitoring

    Science.gov (United States)

    Hachay, Olga; Khachay, Andrey

    2017-04-01

    Geological medium is an open system which is influenced by outer and inner factors that can lead it to an unstable state. Such non stability usually occurred locally in zones, which we name as dynamically active elements. They can be indicators of potential catastrophic events. These zones differ from the surrounding geological medium by their structural forms, which are often of hierarchical type. The process of their activization can be researched with use of wave fields monitoring. For that purpose we had earlier developed algorithms of modeling wave field propagation through the local objects with hierarchical structure. This paper concerns a new approach for interpretation of the distribution of wave fields for determining of the contours of these local hierarchical objects. In this work we consider an algorithm for constructing of two equations of theoretical inverse problem for 2D linear polarized transverse elastic wave and transverse electromagnetic field by excitation of the N-layered elastic and conductive medium with hierarchic elastic, anomaly stressed and magnetic inclusion located in the ν-th layer with the density and conductivity equal to the density and conductivity of the layer. An iteration process of solving the inverse problem for the case of certain configurations of hierarchical 2-D inclusions of k-th rank is elaborated. When interpreting the results of the monitoring it is needed to use the data of such systems that are configured to study the hierarchical structure of the medium. Findings. From the theory it is obviously that for such complicated medium each wave field contains its own information about the inner structure of the hierarchical inclusion. Therefore it is needed to interpret the monitoring data for each wave field apart, and not mixes the data base. Practical value/implications. These results will be the base for constructing new systems of monitoring observations of dynamical geological systems. Especially it is needed to

  9. Passive Acoustic Monitoring the Diel, Lunar, Seasonal and Tidal Patterns in the Biosonar Activity of the Indo-Pacific Humpback Dolphins (Sousa chinensis in the Pearl River Estuary, China.

    Directory of Open Access Journals (Sweden)

    Zhi-Tao Wang

    Full Text Available A growing demand for sustainable energy has led to an increase in construction of offshore windfarms. Guishan windmill farm will be constructed in the Pearl River Estuary, China, which sustains the world's largest known population of Indo-Pacific humpback dolphins (Sousa chinensis. Dolphin conservation is an urgent issue in this region. By using passive acoustic monitoring, a baseline distribution of data on this species in the Pearl River Estuary during pre-construction period had been collected. Dolphin biosonar detection and its diel, lunar, seasonal and tidal patterns were examined using a Generalized Linear Model. Significant higher echolocation detections at night than during the day, in winter-spring than in summer-autumn, at high tide than at flood tide were recognized. Significant higher echolocation detections during the new moon were recognized at night time. The diel, lunar and seasonal patterns for the echolocation encounter duration also significantly varied. These patterns could be due to the spatial-temporal variability of dolphin prey and illumination conditions. The baseline information will be useful for driving further effective action on the conservation of this species and in facilitating later assessments of the effects of the offshore windfarm on the dolphins by comparing the baseline to post construction and post mitigation efforts.

  10. Passive Acoustic Monitoring the Diel, Lunar, Seasonal and Tidal Patterns in the Biosonar Activity of the Indo-Pacific Humpback Dolphins (Sousa chinensis) in the Pearl River Estuary, China.

    Science.gov (United States)

    Wang, Zhi-Tao; Nachtigall, Paul E; Akamatsu, Tomonari; Wang, Ke-Xiong; Wu, Yu-Ping; Liu, Jian-Chang; Duan, Guo-Qin; Cao, Han-Jiang; Wang, Ding

    2015-01-01

    A growing demand for sustainable energy has led to an increase in construction of offshore windfarms. Guishan windmill farm will be constructed in the Pearl River Estuary, China, which sustains the world's largest known population of Indo-Pacific humpback dolphins (Sousa chinensis). Dolphin conservation is an urgent issue in this region. By using passive acoustic monitoring, a baseline distribution of data on this species in the Pearl River Estuary during pre-construction period had been collected. Dolphin biosonar detection and its diel, lunar, seasonal and tidal patterns were examined using a Generalized Linear Model. Significant higher echolocation detections at night than during the day, in winter-spring than in summer-autumn, at high tide than at flood tide were recognized. Significant higher echolocation detections during the new moon were recognized at night time. The diel, lunar and seasonal patterns for the echolocation encounter duration also significantly varied. These patterns could be due to the spatial-temporal variability of dolphin prey and illumination conditions. The baseline information will be useful for driving further effective action on the conservation of this species and in facilitating later assessments of the effects of the offshore windfarm on the dolphins by comparing the baseline to post construction and post mitigation efforts.

  11. ACOUSTIC EMISSION MONITORING FOR WIND TURBINE BLADE COMPOSITE MATERIAL UNDER COMPRESSIVE DAMAGE FAILURE CONDITION%风电叶片复合材料压缩损伤破坏声发射监测

    Institute of Scientific and Technical Information of China (English)

    周伟; 张晓霞; 韦子辉; 钟旸

    2011-01-01

    研究了风电叶片单向复合材料的压缩力学特性及其声发射响应特征.结果表明,复合材料的横向和纵向压缩力学性能及其声发射响应特性明显不同,纵向压缩强度、模量高,失效应变小,对应的声发射相对能量、幅度高,但撞击累积总数少.复合材料具有脆性破坏的特点,横向压缩以45°剪切失效为主,纵向压缩以层间劈裂为主.风电叶片复合材料压缩损伤破坏与声发射的相对能量、幅度、撞击等参量特征有关.%The compressive tests and acoustic emission (AE) response characteristics of wind turbine blade composite material were conducted.The results showed that transverse compressive properties and corresponding AE characteristics of composite material were different to longitudinal direction.High compressive strength, high modulus, low failure strain, high AE relative energy, high amplitude and less cumulative hits were obtained in longitudinal direction.Furthermore, composite specimens exhibited brittle characteristics.The main failure modes of transverse and longitudinal compression were 45° shear failure and layer splitting, respectively.The AE monitoring results such as energy, amplitude, hits and other parameters in compressive tests were useful for monitoring the damage development and failure of the specimen.

  12. An Energy Harvesting Underwater Acoustic Transmitter for Aquatic Animals

    Energy Technology Data Exchange (ETDEWEB)

    Li, Huidong; Tian, Chuan; Lu, Jun; Myjak, Mitchell J.; Martinez, Jayson J.; Brown, Richard S.; Deng, Zhiqun Daniel

    2016-09-20

    This paper presents a self-powered underwater acoustic transmitter using a piezoelectric beam to harvest the mechanical energy from fish swimming. This transmitter does not require a battery and is demonstrated in live fish. It transmits an acoustic waveform as the implanted fish swims. It enables long-term monitoring of aquatic animals.

  13. Acoustics aspects of technological process in the rock disintegration

    Directory of Open Access Journals (Sweden)

    Jozef Futó

    2007-04-01

    Full Text Available The paper describes some results of monitoring and aspects of the acoustic signal in the rock disintegration on the drillig stand of the Institute of Geotechnics, SAS in Košice. The registration and processing of the acoustic signal is solved as a part of the research grant task within the basic research of the rock disintegration by drilling.

  14. 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...

  15. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... acoustic neuroma resource Click to learn more... LOGIN EVENTS DONATE Home Learn Back Learn about acoustic neuroma ... support group for me? Find a Group Upcoming Events Video Library Photo Gallery One-on-One Support ...

  16. Discrimination of American ginseng and Asian ginseng using electronic nose and gas chromatography–mass spectrometry coupled with chemometrics

    Directory of Open Access Journals (Sweden)

    Shaoqing Cui

    2017-01-01

    Conclusion: Combined with advanced chemometrics, the E-nose is capable of discriminating between American and Asian ginseng in both qualitative and quantitative angles, presenting an accurate, rapid, and nondestructive reference approach.

  17. 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 pr...

  18. 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).

  19. Classification of Tempranillo wines according to geographic origin: Combination of mass spectrometry based electronic nose and chemometrics

    Energy Technology Data Exchange (ETDEWEB)

    Cynkar, Wies, E-mail: wies.cynkar@awri.com.au [Australian Wine Research Institute, PO Box 197, Glen Osmond, SA 5064 (Australia); Dambergs, Robert [Australian Wine Research Institute, Tasmanian Institute of Agricultural Research, University of Tasmania, Private Bag 98, Hobart Tasmania 7001 (Australia); Smith, Paul; Cozzolino, Daniel [Australian Wine Research Institute, PO Box 197, Glen Osmond, SA 5064 (Australia)

    2010-02-15

    Rapid methods employing instruments such as electronic noses (EN) or gas sensors are used in the food and beverage industries to monitor and assess the composition and quality of products. Similar to other food industries, the wine industry has a clear need for simple, rapid and cost effective techniques for objectively evaluating the quality of grapes, wine and spirits. In this study a mass spectrometry based electronic nose (MS-EN) instrument combined with chemometrics was used to predict the geographical origin of Tempranillo wines produced in Australia and Spain. The MS-EN data generated were analyzed using principal components analysis (PCA), partial least squares discriminant analysis (PLS-DA) and stepwise linear discriminant analysis (SLDA) with full cross validation (leave-one-out method). The SLDA classified correctly 86% of the samples while PLS-DA 85% of Tempranillo wines according to their geographical origin. The relative benefits of using MS-EN will provide capability for rapid screening of wines. However, this technique does not provide the identification and quantitative determination of individual compounds responsible for the different aroma notes in the wine.

  20. Laser-induced breakdown spectroscopy-based investigation and classification of pharmaceutical tablets using multivariate chemometric analysis.

    Science.gov (United States)

    Myakalwar, Ashwin Kumar; Sreedhar, S; Barman, Ishan; Dingari, Narahara Chari; Venugopal Rao, S; Prem Kiran, P; Tewari, Surya P; Manoj Kumar, G

    2011-12-15

    We report the effectiveness of laser-induced breakdown spectroscopy (LIBS) in probing the content of pharmaceutical tablets and also investigate its feasibility for routine classification. This method is particularly beneficial in applications where its exquisite chemical specificity and suitability for remote and on site characterization significantly improves the speed and accuracy of quality control and assurance process. Our experiments reveal that in addition to the presence of carbon, hydrogen, nitrogen and oxygen, which can be primarily attributed to the active pharmaceutical ingredients, specific inorganic atoms were also present in all the tablets. Initial attempts at classification by a ratiometric approach using oxygen (∼777 nm) to nitrogen (742.36 nm, 744.23 nm and 746.83 nm) compositional values yielded an optimal value at 746.83 nm with the least relative standard deviation but nevertheless failed to provide an acceptable classification. To overcome this bottleneck in the detection process, two chemometric algorithms, i.e. principal component analysis (PCA) and soft independent modeling of class analogy (SIMCA), were implemented to exploit the multivariate nature of the LIBS data demonstrating that LIBS has the potential to differentiate and discriminate among pharmaceutical tablets. We report excellent prospective classification accuracy using supervised classification via the SIMCA algorithm, demonstrating its potential for future applications in process analytical technology, especially for fast on-line process control monitoring applications in the pharmaceutical industry. Copyright © 2011 Elsevier B.V. All rights reserved.

  1. Chemometric model for simultaneous spectrophotometric estimation of phenobarbitone and phenytoin sodium in tablets using back-propagation neural network

    Directory of Open Access Journals (Sweden)

    Satyanarayana D

    2006-01-01

    Full Text Available A chemometric model for the simultaneous estimation of phenobarbitone and phenytoin sodium anticonvulsant tablets using the back-propagation neural network calibration has been presented. The use of calibration datasets constructed from the spectral data of pure components is proposed. The calibration sets were designed such that the concentrations were orthogonal and span the possible mixture space fairly evenly. Spectra of phenobarbitone and phenytoin sodium were recorded at several concentrations within their linear range and used to compute the calibration mixture between wavelengths 220 and 260 nm at an interval of 1 nm. The back-propagation neural network model was optimized using three different sets of calibration and monitoring data for the number of hidden sigmoid neurons. The calibration model was thoroughly evaluated at several concentration levels using spectra obtained for 95 synthetic binary mixtures prepared using orthogonal designs. The optimized model showed sufficient robustness even when the calibration sets were constructed from different sets of pure spectra of components. Although the components showed complete spectral overlap, the model could accurately estimate the drugs, with satisfactory precision and accuracy, in tablet dosage with no interference from excipients, as indicated by the recovery study results.

  2. Passive Acoustic Studies of North Atlantic Right Whales

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Passive acoustic monitoring buoys have been deployed in shallow waters between North Carolina and Northern Florida since 2003. These units are bottom mounted...

  3. Potential of acoustic emissions from three point bending tests as rock failure precursors

    Institute of Scientific and Technical Information of China (English)

    Agioutantis Z.; Kaklis K.; Mavrigiannakis S.; Verigakis M.; Vallianatos F.; Saltas V.

    2016-01-01

    Development of failure in brittle materials is associated with microcracks, which release energy in the form of elastic waves called acoustic emissions. This paper presents results from acoustic emission mea-surements obtained during three point bending tests on Nestos marble under laboratory conditions. Acoustic emission activity was monitored using piezoelectric acoustic emission sensors, and the potential for accurate prediction of rock damage based on acoustic emission data was investigated. Damage local-ization was determined based on acoustic emissions generated from the critically stressed region as scat-tered events at stresses below and close to the strength of the material.

  4. Program to develop acoustic emission-flaw relationship for inservice monitoring of nuclear pressure vessels. Annual report, July 1, 1976 - October 1, 1977

    Energy Technology Data Exchange (ETDEWEB)

    Hutton, P.H.; Kurtz, R.J.; Schwenk, E.B.; Pavloff, C.

    1978-06-01

    Laboratory mechanical tests were conducted to evaluate AE during uniaxial tensile, fracture and fatigue crack growth in A533B pressure vessel steel. The A533B steel included two heats of Class 1, one heat of Class 2 and a weldment made for the Heavy Section Steel Technology (HSST) Program. Specimen types included uniaxial tensile specimens, size 2 compact tension specimens for fatigue crack growth and fracture tests, and a single-edge notch specimen also for fatigue crack growth through material that was uniformly strained 3% prior to fatigue testing. In addition, AE monitoring was conducted on the HSST V-7B 6-inch thick pressure vessel test. AE data were partitioned into four ranges of signal amplitude and rise time. All the AE data were analyzed, with respect to mechanical behavior of A533B steel. Linear elastic fracture mechanics analysis methods were used to relate AE parameters to fracture and fatigue crack growth parameters. AE data from the V-7B vessel test were correlated with stress intensity factor and crack opening displacement. AE data from the fatigue crack growth tests were investigated using models based on fatigue crack growth rate, fatigue crack area and theoretical crack tip plastic zone size.

  5. Blue and fin whale acoustics and ecology off Antarctic Peninsula

    OpenAIRE

    2006-01-01

    Blue (Balaenoptera musculus) and fin whales (B. physalus) in the Southern Ocean were subjects of extensive whaling industry during the twentieth century. Their current population numbers remain low, making population monitoring using traditional visual surveys difficult. Both blue and fin whales produce low frequency, regularly repeated calls and are suitable for acoustic monitoring. Eight, continuously recording acoustic recorders were deployed off the Western Antarctic Peninsula (WAP) betwe...

  6. Inspection of copper canister for spent nuclear fuel by means of ultrasound. Copper characterization, FSW monitoring with acoustic emission and ultrasonic imaging

    Energy Technology Data Exchange (ETDEWEB)

    Stepinski, Tadeusz (ed.); Engholm, Marcus; Olofsson, Tomas (Uppsala Univ., Signals and Systems, Dept. of Technical Sciences, Uppsala (Sweden))

    2009-08-15

    This report contains the research results concerning advanced ultrasound for the inspection of copper canisters for spent nuclear fuel obtained at Signals and Systems, Uppsala University in 2008. The first part of the report is concerned with aspects related to ultrasonic attenuation of copper material used for canisters. We present results of attenuation measurement performed for a number of samples taken from a real canister; two from the lid and four from different parts of canister wall. Ultrasonic attenuation of the material originating from canister lid is relatively low (less that 50 dB/m) and essentially frequency independent in the frequency range up to 5 MHz. However, for the material originating from the extruded canister part considerable variations of the attenuation are observed, which can reach even 200 dB/m at 3.5 MHz. In the second part of the report we present further development of the concept of the friction stir welding process monitoring by means of multiple sensors formed into a uniform circular array (UCA). After a brief introduction into modeling Lamb waves and UCA we focus on array processing techniques that enable estimating direction of arrival of multimodal Lamb waves. We consider two new techniques, the Capon beamformer and the broadband multiple signal classification technique (MUSIC). We present simulation results illustrating their performance. In the final part we present the phase shift migration algorithm for ultrasonic imaging of layered media using synthetic aperture concept. We start from explaining theory of the phase migration concept, which is followed by the results of experiments performed on copper blocks with drilled holes. We show that the proposed algorithm performs well for immersion inspection of metal objects and yields both improved spatial resolution and suppressed grain noise

  7. 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...... and interoperability with Grasshopper 3d. The focus will be placed to the benchmarking of three different acoustic analysis tools based on raytracing. To compare the accuracy and speed of the acoustic evaluation across different tools, a homogeneous set of acoustic parameters is chosen. The room acoustics parameters...... included in the set are reverberation time (EDT, RT30), clarity (C50), loudness (G), and definition (D50). Scenarios are discussed for determining at different design stages the most suitable acoustic tool. Those scenarios are characterized, by the use of less accurate but fast evaluation tools to be used...

  8. Monitoring of pipeline hydrostatic testing with artificial flaws applying acoustic emission and ultra-sonic techniques; Monitoracao de teste hidrostatico de tubos com descontinuidades artificiais empregando as tecnicas de emissao acustica e ultra-som

    Energy Technology Data Exchange (ETDEWEB)

    Soares, Sergio Damasceno [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

    2003-07-01

    Charts and parameters used to perform and analyzing the acoustic emission data collected during the hydrostatic test in pipe samples build in API XL 60 with 20 inches of diameter and 14 millimeters of thickness are shown. These pipes had internal and external artificial flaws done by electro-erosion process with aspect ratio 1 x 20. A relationship between acoustic emission results, ultrasound and J-Integral were established using the applied pressurization sequence. Characteristics values of acoustic emission signals were shown as a criteria of field tests. (author)

  9. Detection of cow milk in donkey milk by chemometric procedures on triacylglycerol stereospecific analysis results.

    Science.gov (United States)

    Cossignani, Lina; Blasi, Francesca; Bosi, Ancilla; D'Arco, Gilda; Maurelli, Silvia; Simonetti, Maria Stella; Damiani, Pietro

    2011-08-01

    Stereospecific analysis is an important tool for the characterization of lipid fraction of food matrices, and also of milk samples. The results of a chemical-enzymatic-chromatographic analytical method were elaborated by chemometric procedures such as linear discriminant analysis (LDA) and artificial neural network (ANN). According to the total composition and intrapositional fatty acid distribution in the triacylglycerol (TAG) backbone, the obtained results were able to characterize pure milk samples and milk mixtures with 1, 3, 5% cow milk added to donkey milk. The resulting score was very satisfactory. Totally correct classified samples were obtained when the TAG stereospecific results of all the considered milk mixtures (donkey-cow) were elaborated by LDA and ANN chemometric procedures.

  10. Application of terahertz spectroscopy imaging for discrimination of transgenic rice seeds with chemometrics.

    Science.gov (United States)

    Liu, Wei; Liu, Changhong; Hu, Xiaohua; Yang, Jianbo; Zheng, Lei

    2016-11-01

    Discrimination of genetically modified organisms is increasingly demanded by legislation and consumers worldwide. The feasibility of a non-destructive discrimination of transgenic rice seeds from its non-transgenic counterparts was examined by terahertz spectroscopy imaging system combined with chemometrics. Principal component analysis (PCA), least squares support vector machines (LS-SVM), PCA-back propagation neural network (PCA-BPNN), and random forest (RF) models with the first and second derivative and standard normal variate transformation (SNV) pre-treatments were applied to classify rice seeds based on genotype. The results demonstrated that differences between non-transgenic and transgenic rice seeds did exist, and an excellent classification (accuracy was 96.67% in the prediction set) could be achieved using the RF model combined with the first derivative pre-treatment. The results indicated that THz spectroscopy imaging together with chemometrics would be a promising technique to identify transgenic rice seeds with high efficiency and without any sample preparation.

  11. Classification of traditional Chinese pork bacon based on physicochemical properties and chemometric techniques.

    Science.gov (United States)

    Guo, Xin; Huang, Feng; Zhang, Hong; Zhang, Chunjiang; Hu, Honghai; Chen, Wenbo

    2016-07-01

    Sixty-seven pork bacon samples from Hunan, Sichuan Guangdong, Jiangxi, and Yunnan Provinces in China were analyzed to understand their geographical properties. Classification was performed by determining their physicochemical properties through chemometric techniques, including variance analysis, principal component analysis (PCA), and discriminant analysis (DA). Results showed that certain differences existed in terms of nine physicochemical determinations in traditional Chinese pork bacon. PCA revealed the distinction among Hunan, Sichuan, and Guangdong style bacon. Meanwhile, seven key physicochemical determination criteria were identified in line with DA and could be reasonably applied to the classification of traditional Chinese pork bacon. Furthermore, the ratio of overall correct classification was 97.76% and that of cross-validation was 91.76%. These findings indicated that chemometric techniques, together with several physicochemical determination, were effective for the classification of traditional Chinese pork bacon with geographical features. Our study provided a theoretical reference for the classification of traditional Chinese pork bacon.

  12. NMR spectroscopy and chemometrics to evaluate different processing of coconut water.

    Science.gov (United States)

    Sucupira, N R; Alves Filho, E G; Silva, L M A; de Brito, E S; Wurlitzer, N J; Sousa, P H M

    2017-02-01

    NMR and chemometrics was applied to understand the variations in chemical composition of coconut water under different processing. Six processing treatments were applied to coconut water and analyzed: two control (with and without sulphite), and four samples thermally processed at 110°C and 136°C (with and without sulphite). Samples processed at lower temperature and without sulphite presented pink color under storage. According to chemometrics, samples processed at higher temperature exhibited lower levels of glucose and malic acid. Samples with sulphite processed at 136°C presented lower amount of sucrose, suggesting the degradation of the carbohydrates after harshest thermal treatment. Samples with sulphite and processed at lower temperature showed higher concentration of ethanol. However, no significant changes were verified in coconut water composition as a whole. Sulphite addition and the temperature processing to 136°C were effective to prevent the pinking and to maintain the levels of main organic compounds.

  13. Chemometric methods for studying the relationships between trace elements in laryngeal cancer and healthy tissues.

    Science.gov (United States)

    Dobrowolski, R; Klatka, J; Brodnjak-Voncina, D; Trojanowska, A; Myśliwiec, D; Ostrowski, J; Remer, M

    2014-06-01

    A quick and reliable method for the evaluation and classification of two types of tissues is presented. Several chemometric methods were applied to evaluate multivariate data of the tissue samples with respect to the content of trace elements. The content of Pb, Al, Zn, Cd, Cu, Ni and Co was determined in samples of healthy and cancerous tissue obtained from 26 patients. Determination was done at milligram/kilogram level with inductively coupled plasma optical emission spectrometry (ICP-OES) and atomic absorption spectroscopy (AAS) techniques. Contents of trace metals in studied tissues are not normally distributed; however, normal distribution was confirmed for log values. There is a statistically significant difference in the content of Zn, Cd, Cu and Al (pcontents of trace elements for studied tissues was positive; the highest was found between Zn and Cu. A chemometric methodology seems to be a promising tool for classifications of the tissue samples.

  14. New insights in forensic chemistry: NIR/Chemometrics analysis of toners for questioned documents examination.

    Science.gov (United States)

    Materazzi, Stefano; Risoluti, Roberta; Pinci, Sara; Saverio Romolo, Francesco

    2017-11-01

    Near-Infrared spectroscopy (NIRs) coupled to chemometrics was investigated for the first time as a new tool for the analysis of black toners to evaluate its application in forensic cases. Ten black toners from four manufacturers were included in this study and the acquired spectra were compared in order to differentiate toners. Multivariate statistical analysis based on Principal Component Analysis (PCA) was considered to develop a model of comparison of toners in questioned documents. Results demonstrated the capabilities of the approach NIR/Chemometrics to correctly identify toners when printed on different papers and to be not affected by the printing process. This study has shown that NIRs can be considered as a useful, fast, non-destructive tool providing the characterisation of toners in forensic caseworks. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. New chemometric approach MCR-ALS to unmix EPR spectroscopic data from complex mixtures

    Science.gov (United States)

    Fadel, Maya Abou; de Juan, Anna; Touati, Nadia; Vezin, Hervé; Duponchel, Ludovic

    2014-11-01

    Electron paramagnetic resonance (EPR) spectra of mixtures are often difficult to interpret due to the superposition of spectral contribution of various species present in the complex materials. It is challenging to accurately identify the number of pure compounds present and to extract their pure spectra. In this study, the powerful chemometric method, multivariate curve resolution-alternating least squares (MCR-ALS), is applied to identify different paramagnetic centers. This method is used to simultaneously extract, with no prior knowledge, the pure spectra and the corresponding concentration profiles of all the compounds in the unknown and unresolved mixtures. The goal of our work is to apply, for the first time, this new chemometrics methodology, MCR-ALS, on EPR spectroscopic data in order to characterize a series of distinct but strongly overlapping spectra of various paramagnetic species.

  16. Determination of antioxidant content and antioxidant activity in foods using infrared spectroscopy and chemometrics: a review.

    Science.gov (United States)

    Lu, Xiaonan; Rasco, Barbara A

    2012-01-01

    Developing rapid analytical methods for bioactive components and predicting both the concentration and biological availability of nutraceutical components in foods is a topic of growing interest. Here, analysis of bioactive components and total antioxidant activity in food matrices using infrared spectroscopy coupled with chemometric predictive models is described. Infrared spectroscopy offers an alternative to wet chemistry, chromatographic determination of antioxidants, and in vitro biochemical assays for assessment of antioxidant activity. Spectroscopic methods provide a technique that can be used with biological tissues without extraction, which can often lead to degradation of the antioxidant components. Sample preparation time greatly decreases and analysis time is very short once a predictive model has been developed. Spectroscopic methods can have a high degree of precision when applied to analysis of nutraceutical compound concentration and antioxidant activity in foods. This article summarizes recent advances in vibrational spectroscopy and chemometrics and applications of these methods for antioxidant detection in foods.

  17. Iron-induced oxidative stress in a macrophyte: a chemometric approach.

    Science.gov (United States)

    Sinha, Sarita; Basant, Ankita; Malik, Amrita; Singh, Kunwar P

    2009-02-01

    Iron-induced oxidative stress in plants of Bacopa monnieri L., a macrophyte with medicinal value, was investigated using the chemometric approach. Cluster analysis (CA) rendered two distinct clusters of roots and shoots. Discriminant analysis (DA) identified discriminating variables (NP-SH and APX) between the root and shoot tissues. Principal component analysis (PCA) results suggested that protein, superoxide dismutase (SOD), ascorbic acid, proline, and Fe uptake are dominant in root tissues, whereas malondialdehyde (MDA), guaiacol peroxidase (POD), cysteine, and non-protein thiol (NP-SH) in shoot of the stress plant. Discriminant partial-least squares (DPLS) results further confirmed that SOD and ascorbic acid contents dominated in root tissues, while NP-SH, cysteine, POD, ascorbate peroxidase (APX), and MDA in shoot. MDA and NP-SH were identified as most pronounced variables in plant during the highest exposure time. The chemometric approach allowed for the interpretation of the induced biochemical changes in plant tissues exposed to iron.

  18. Acoustic estimation of suspended sediment concentration

    Institute of Scientific and Technical Information of China (English)

    ZHU; Weiqing(

    2001-01-01

    [1]Morse, P. H. , Theoretical Acoustics, New York: McGraw-Hill Book Co. , 1968.[2]Skudrjuk, E., Die Grundlagen der Akustik, Wien: Springer-Verlag, 1954.[3]Olshevskii, V. V., Statistical Characteristics of Sea Reverberation, Moscow: Nauka Publisher, 1966.[4]Thorne, P. D., Hardcastl, P. J., Soulsby, R. L., Analysis of acoustic measurements of suspended sediments, J. Geop.Res. , 1993, 98: 899.[5]Guo Jijie, Ren Laifa, Li Yunwu, ln-situ calibration of acoustic measurement of suspended sedienmt, Acta Oceanologica Sini-ca, 1998, (20): 120-125.[6]Zhang Shuying, Li Yunwu, Development and application of an acoustic suspended sediemnt monitoring system, Acta Oceanologica Sinica, 1998, (20): 114-119.[7]Zhang Shuying, Li Yunwu, A theoretical analysis of acoustic suspended sediment obsvervation, Acta Acoustica, 1999, (24):267-274.[8]Zhu Weiqing, Pan Feng, Zhu Min et al. , IOA-1 Multi-function Acoustic Doppler Current Profiler (MADCP), OCEAN'2000,Rhode Island, USA.

  19. Acoustic Emission of Deformation Twinning in Magnesium

    Directory of Open Access Journals (Sweden)

    Chengyang Mo

    2016-08-01

    Full Text Available The Acoustic Emission of deformation twinning in Magnesium is investigated in this article. Single crystal testing with combined full field deformation measurements, as well as polycrystalline testing inside the scanning electron microscope with simultaneous monitoring of texture evolution and twin nucleation were compared to testing at the laboratory scale with respect to recordings of Acoustic Emission activity. Single crystal testing revealed the formation of layered twin boundaries in areas of strain localization which was accompanied by distinct changes in the acoustic data. Testing inside the microscope directly showed twin nucleation, proliferation and growth as well as associated crystallographic reorientations. A post processing approach of the Acoustic Emission activity revealed the existence of a class of signals that appears in a strain range in which twinning is profuse, as validated by the in situ and ex situ microscopy observations. Features extracted from such activity were cross-correlated both with the available mechanical and microscopy data, as well as with the Acoustic Emission activity recorded at the laboratory scale for similarly prepared specimens. The overall approach demonstrates that the method of Acoustic Emission could provide real time volumetric information related to the activation of deformation twinning in Magnesium alloys, in spite of the complexity of the propagation phenomena, the possible activation of several deformation modes and the challenges posed by the sensing approach itself when applied in this type of materials evaluation approach.

  20. Acoustical experiment of yogurt fermentation process.

    Science.gov (United States)

    Ogasawara, H; Mizutani, K; Ohbuchi, T; Nakamura, T

    2006-12-22

    One of the important factors through food manufacturing is hygienic management. Thus, food manufactures prove their hygienic activities by taking certifications like a Hazard Analysis and Critical Control Point (HACCP). This concept also applies to food monitoring. Acoustical measurements have advantage for other measurement in food monitoring because they make it possible to measure with noncontact and nondestructive. We tried to monitor lactic fermentation of yogurt by a probing sensor using a pair of acoustic transducers. Temperature of the solution changes by the reaction heat of fermentation. Consequently the sound velocity propagated through the solution also changes depending on the temperature. At the same time, the solution change its phase from liquid to gel. The transducers usage in the solution indicates the change of the temperature as the change of the phase difference between two transducers. The acoustic method has advantages of nondestructive measurement that reduces contamination of food product by measuring instrument. The sensor was inserted into milk with lactic acid bacterial stain of 19 degrees C and monitored phase retardation of propagated acoustic wave and its temperature with thermocouples in the mild. The monitoring result of fermentation from milk to Caspian Sea yogurt by the acoustic transducers with the frequency of 3.7 MHz started to show gradient change in temperature caused by reaction heat of fermentation but stop the gradient change at the end although the temperature still change. The gradient change stopped its change because of phase change from liquid to gel. The present method will be able to measure indirectly by setting transducers outside of the measuring object. This noncontact sensing method will have great advantage of reduces risk of food contamination from measuring instrument because the measurement probes are set out of fermentation reactor or food containers. Our proposed method will contribute to the