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Sample records for acoustic test setup

  1. Status of the South Pole Acoustic Test Setup

    Due to the low flux of ultra-high energetic neutrinos induced in interactions of cosmic rays with the cosmic microwave background, very large instrumented volumes and new registration techniques are necessary for their detection. The south polar ice offers the unique opportunity to implement existing Cherenkov techniques as well as registration of radio and acoustic waves from the neutrino interaction. A simulation of a ∼ 120 km3 hybrid optical/radio/acoustic detector showed that event rates of ∼ 10 per year can be achieved. In this simulation the ultrasonic parameters of antarctic ice regarding absorption, scattering and environmental noise pose the key uncertainty. To evaluate the acoustic properties in-situ, the South Pole Acoustic Test Setup (SPATS) has been created. An array of custom-made ultrasonic sensors and transmitters will be deployed on three strings in the upper 400 m of the holes of the IceCube experiment. The status of the experiment and a first evaluation of its performance are presented here

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

    Karg, Timo

    2010-01-01

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

  3. Non-contact test set-up for aeroelasticity in a rotating turbomachine combining a novel acoustic excitation system with tip-timing

    Due to trends in aero-design, aeroelasticity becomes increasingly important in modern turbomachines. Design requirements of turbomachines lead to the development of high aspect ratio blades and blade integral disc designs (blisks), which are especially prone to complex modes of vibration. Therefore, experimental investigations yielding high quality data are required for improving the understanding of aeroelastic effects in turbomachines. One possibility to achieve high quality data is to excite and measure blade vibrations in turbomachines. The major requirement for blade excitation and blade vibration measurements is to minimize interference with the aeroelastic effects to be investigated. Thus in this paper, a non-contact—and thus low interference—experimental set-up for exciting and measuring blade vibrations is proposed and shown to work. A novel acoustic system excites rotor blade vibrations, which are measured with an optical tip-timing system. By performing measurements in an axial compressor, the potential of the acoustic excitation method for investigating aeroelastic effects is explored. The basic principle of this method is described and proven through the analysis of blade responses at different acoustic excitation frequencies and at different rotational speeds. To verify the accuracy of the tip-timing system, amplitudes measured by tip-timing are compared with strain gage measurements. They are found to agree well. Two approaches to vary the nodal diameter (ND) of the excited vibration mode by controlling the acoustic excitation are presented. By combining the different excitable acoustic modes with a phase-lag control, each ND of the investigated 30 blade rotor can be excited individually. This feature of the present acoustic excitation system is of great benefit to aeroelastic investigations and represents one of the main advantages over other excitation methods proposed in the past. In future studies, the acoustic excitation method will be used

  4. Setup for testing LHCb Inner Tracker ladders

    Vasquez Regueiro, P; Voss, H; Nicolas, L

    2007-01-01

    The Inner Tracker of the LHCb experiment is a silicon microstrip detector consisting of 336 detector modules with either one or two sensors. The module production is now underway and we present here the setup employed for module testing during the production. The setup is based on the same electronics that will be used in the final experiment. We perform burn-in and ageing tests with the help of a custom made Temperature Cycling Box controlled with LabVIEW under Windows. The DAQ is done in another PC running Linux. Here we integrate the different C/C++ libraries used to communicate to the LHCb Time and Fast Control system, Experiment Control System and Data Acquisition.

  5. Acoustics Noise Test Cell

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

  6. Practical acoustic emission testing

    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.

  7. Acoustic emission testing

    Grosse, Christian U

    2008-01-01

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

  8. Test Setup for Axially Loaded Piles in Sand

    Thomassen, Kristina

    The test setup for testing axially static and cyclic loaded piles in sand is described in the following. The purpose for the tests is to examine the tensile capacity of axially loaded piles in dense fully saturated sand. The pile dimensions are chosen to resemble full scale dimension of piles used...

  9. Cryogenic Acoustic Suppression Testing Project

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

  10. Reverberant Acoustic Test Facility (RATF)

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

  11. A Shack Interferometer Setup for Optical Testing in Undergraduate Courses

    Vannoni, Maurizio; Righini, Alberto; Salas, Matias; Sordini, Andrea; Vanzi, Leonardo

    2012-01-01

    The Shack interferometer is a simple and effective device to test optical surfaces in reflection and optical systems in transmission. An essential setup on a reduced scale with a minimum number of components is presented, suited to gain familiarity and practice with optical testing in a laboratory course for undergraduate students. The basic…

  12. Quick setup of test unit for accelerator control system

    Testing a single hardware unit of an accelerator control system often requires the setup of a program with graphical user interface. Developing a dedicated application for a specific hardware unit test could be time consuming and the application may become obsolete after the unit tests. This paper documents a methodology for quick design and setup of an interface focused on performing unit tests of accelerator equipment with minimum programming work. The method has three components. The first is a generic accelerator device object (ADO) manager which can be used to setup, store, and log testing controls parameters for any unit testing system. The second involves the design of a TAPE (Tool for Automated Procedure Execution) sequence file that specifies and implements all te testing and control logic. The sting third is the design of a PET (parameter editing tool) page that provides the unit tester with all the necessary control parameters required for testing. This approach has been used for testing the horizontal plane of the Stochastic Cooling Motion Control System at RHIC.

  13. Comparison of Silicon Photomultiplier Characteristics using Automated Test Setups

    Bauß, B.; Brogna, A. S.; Büscher, V.; Chau, P.; Degele, R.; Geib, K. H.; Krause, S.; Liu, Y.; Schäfer, U.; Spreckels, R.; Tapprogge, S.; Wanke, R.; Weitzel, Q.

    2016-02-01

    Silicon Photomultipliers (SiPM) are photo-sensors consisting of an array of hundreds to thousands pixels with a typical pitch of 10-100 μm. They exhibit an excellent photon counting and time resolution. Therefore applications of SiPMs are emerging in many fields. In order to characterize SiPMs, the PRISMA Detector Lab at Mainz has established three automated test setups. Setup-A is dedicated to measure the gain, the dark count rate and the optical crosstalk probability. The temperature dependencies are characterized by operating the setup in a climate chamber. Setup-B is an optical system to measure the photon detection efficiency. Setup-C addresses the most challenging aspect of comparing SiPMs which is the uniformity of the active surface. Because of the small pixel size, a micro focus lens is attached to a picosecond laser diode to collimate the beam into the sub-structures of the sensors. A three-axis micro-positioning system moves the SiPMs into the focus of the laser spot and then automatically scans the active surfaces. In this paper we present the measurements of several SiPMs and compare their performance.

  14. Cryogenic actuator testing for the SAFARI ground calibration setup

    de Jonge, C.; Eggens, M.; Nieuwenhuizen, A. C. T.; Detrain, A.; Smit, H.; Dieleman, P.

    2012-09-01

    For the on-ground calibration setup of the SAFARI instrument cryogenic mechanisms are being developed at SRON Netherlands Institute for Space Research, including a filter wheel, XYZ-scanner and a flipmirror mechanism. Due to the extremely low background radiation requirement of the SAFARI instrument, all of these mechanisms will have to perform their work at 4.5 Kelvin and low-dissipative cryogenic actuators are required to drive these mechanisms. In this paper, the performance of stepper motors, piezoelectric actuators and brushless DC-motors as cryogenic actuators are compared. We tested stepper motor mechanical performance and electrical dissipation at 4K. The actuator requirements, test setup and test results are presented. Furthermore, design considerations and early performance tests of the flipmirror mechanism are discussed. This flipmirror features a 102 x 72 mm aluminum mirror that can be rotated 45°. A Phytron stepper motor with reduction gearbox has been chosen to drive the flipmirror. Testing showed that this motor has a dissipation of 49mW at 4K with a torque of 60Nmm at 100rpm. Thermal modeling of the flipmirror mechanism predicts that with proper thermal strapping the peak temperature of the flipmirror after a single action will be within the background level requirements of the SAFARI instrument. Early tests confirm this result. For low-duty cycle operations commercial stepper motors appear suitable as actuators for test equipment in the SAFARI on ground calibration setup.

  15. A new setup for studying thermal microcracking through acoustic emission monitoring

    Griffiths, Luke; Heap, Michael; Baud, Patrick; Schmittbuhl, Jean

    2016-04-01

    Thermal stressing is common in geothermal environments and has been shown in the laboratory to induce changes in the physical and mechanical properties of rocks. These changes are generally considered to be a consequence of the generation of thermal microcracks and debilitating chemical reactions. Thermal microcracks form as a result of the build-up of internal stresses due to: (1) the thermal expansion mismatch between the different phases present in the material, (2) thermal expansion anisotropy within individual minerals, and (3) thermal gradients. The generation of cracks during thermal stressing has been monitored in previous studies using the output of acoustic emissions (AE), a common proxy for microcrack damage, and through microstructural observations. Here we present a new experimental setup which is optimised to record AE from a rock sample at high temperatures and under a servo-controlled uniaxial stress. The design is such that the AE transducer is embedded in the top of the piston, which acts as a continuous wave guide to the sample. In this way, we simplify the ray path geometry whilst minimising the number of interfaces between the microcrack and the transducer, maximising the quality of the signal. This allows for an in-depth study of waveform attributes such as energy, amplitude, counts and duration. Furthermore, the capability of this device to apply a servo-controlled load on the sample, whilst measuring strain in real time, leads to a spectrum of possible tests combining mechanical and thermal stress. It is also an essential feature to eliminate the build-up of stresses through thermal expansion of the pistons and the sample. We plan a systematic experimental study of the AE of thermally stressed rock during heating and cooling cycles. We present results from pilot tests performed on Darley Dale sandstone and Westerly granite. Understanding the effects of thermal stressing in rock is of particular interest at a geothermal site, where

  16. Test setup for the readout electronics of ALICE-PMD

    The readout of the anode signals of the honeycomb chamber with a common cathode structure is to be carried out using gassiplex chips (16 channel CMOS analogue signal processor) developed at CERN. Considering that these chips will be MANAS-16 fabricated in India a comprehensive setup for testing and assembly of chips has been developed at VECC for 3/4 chip boards and associated circuitry like level shifter, repeater and buffer boards

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

    Counter, Douglas D.; Houston, Janie D.

    2011-01-01

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

  18. Magnet Test Setup of the CMS Tracker ready for installation

    Maximilien Brice

    2006-01-01

    The pieces of the Tracker that will be operated in the forthcoming Magnet Test and Cosmic Challenge (MTCC) have been transported inside the dummy tracker support tube to the CMS experimental hall (Point 5, Cessy). The operation took place during the night of 12th May, covering the ~15km distance in about three hours. The transport was monitored for shocks, temperature and humidity with the help of the CERN TS-IC section. The Tracker setup comprises segments of the Tracker Inner Barrel (TIB), the Tracker Outer Barrel (TOB) and Tracker EndCaps (TEC) detectors. It represents roughly 1% of the final CMS Tracker. Installation into the solenoid is foreseen to take place on Wednesday 17th May.

  19. Performance tests of external moderators of a PGNAA setup

    Performance tests of external cylindrical moderators of an accelerator-based prompt gamma ray neutron activation analysis (PGNAA) setup have been carried out through thermal neutrons and prompt γ-ray yield measurements. The PGNAA setup is to be used for analysis of cement samples. This study was conducted to investigate the effects of geometry of cylindrical moderator on yield of thermal neutrons and prompt γ-rays for two different types of moderator assemblies. One of the moderators was to be used with a small sample and the other to be used with a large sample. Fast and thermal neutron yield was measured inside the sample volume as a function of the front moderator thickness as well as sample length. Neutron yield measurement was carried out at the King Fahd University of Petroleum and Minerals 350 keV pulsed beam accelerator using nuclear track detectors. The pulsed 200 keV deuteron beam with 5 ns pulse width and 31.25 kHz frequency was used to produce 2.8 MeV neutrons via D(d,n) reaction. Neutron yield measurements showed that the large sample moderator has a smaller yield of thermal neutrons as compared to the small sample moderator, which is in complete agreement with the results of Monte Carlo yield calculations of the thermal and fast neutrons from both the moderators. Finally, the prompt γ-ray yield from a Portland cement sample was measured using the two moderators and was compared with each other. As predicted by Monte Carlo simulations, in spite of a smaller yield of thermal neutrons, the large sample moderator has a higher yield of prompt γ-rays

  20. Performance tests of external moderators of a PGNAA setup

    Naqvi, A.A. E-mail: aanaqvi@kfupm.edu.sa; Fazal-ur-Rehman,; Al-Jarallah, M.I.; Abu-Jarad, F.; Maslehuddin, M

    2003-01-01

    Performance tests of external cylindrical moderators of an accelerator-based prompt gamma ray neutron activation analysis (PGNAA) setup have been carried out through thermal neutrons and prompt {gamma}-ray yield measurements. The PGNAA setup is to be used for analysis of cement samples. This study was conducted to investigate the effects of geometry of cylindrical moderator on yield of thermal neutrons and prompt {gamma}-rays for two different types of moderator assemblies. One of the moderators was to be used with a small sample and the other to be used with a large sample. Fast and thermal neutron yield was measured inside the sample volume as a function of the front moderator thickness as well as sample length. Neutron yield measurement was carried out at the King Fahd University of Petroleum and Minerals 350 keV pulsed beam accelerator using nuclear track detectors. The pulsed 200 keV deuteron beam with 5 ns pulse width and 31.25 kHz frequency was used to produce 2.8 MeV neutrons via D(d,n) reaction. Neutron yield measurements showed that the large sample moderator has a smaller yield of thermal neutrons as compared to the small sample moderator, which is in complete agreement with the results of Monte Carlo yield calculations of the thermal and fast neutrons from both the moderators. Finally, the prompt {gamma}-ray yield from a Portland cement sample was measured using the two moderators and was compared with each other. As predicted by Monte Carlo simulations, in spite of a smaller yield of thermal neutrons, the large sample moderator has a higher yield of prompt {gamma}-rays.

  1. Performance tests of external moderators of a PGNAA setup.

    Naqvi, A A; Fazal-ur-Rehman; Al-Jarallah, M I; Abu-Jarad, F; Maslehuddin, M

    2003-01-01

    Performance tests of external cylindrical moderators of an accelerator-based prompt gamma ray neutron activation analysis (PGNAA) setup have been carried out through thermal neutrons and prompt gamma-ray yield measurements. The PGNAA setup is to be used for analysis of cement samples. This study was conducted to investigate the effects of geometry of cylindrical moderator on yield of thermal neutrons and prompt gamma-rays for two different types of moderator assemblies. One of the moderators was to be used with a small sample and the other to be used with a large sample. Fast and thermal neutron yield was measured inside the sample volume as a function of the front moderator thickness as well as sample length. Neutron yield measurement was carried out at the King Fahd University of Petroleum and Minerals 350 keV pulsed beam accelerator using nuclear track detectors. The pulsed 200 keV deuteron beam with 5 ns pulse width and 31.25 kHz frequency was used to produce 2.8 MeV neutrons via D(d,n) reaction. Neutron yield measurements showed that the large sample moderator has a smaller yield of thermal neutrons as compared to the small sample moderator, which is in complete agreement with the results of Monte Carlo yield calculations of the thermal and fast neutrons from both the moderators. Finally, the prompt gamma-ray yield from a Portland cement sample was measured using the two moderators and was compared with each other. As predicted by Monte Carlo simulations, in spite of a smaller yield of thermal neutrons, the large sample moderator has a higher yield of prompt gamma-rays. PMID:12485660

  2. Validity test of design calculations of a PGNAA setup

    Naqvi, A.A. E-mail: aanaqvi@kfupm.edu.sa; Garwan, M.A

    2004-01-01

    A rectangular moderator has been designed for the prompt gamma ray neutron activation analysis (PGNAA) setup at King Fahd University of Petroleum and Minerals (KFUPM) to analyze Portland cement samples. The design of the moderator assembly was obtained using Monte Carlo calculations. The design calculations of the new rectangular moderator of the KFUPM PGNAA setup have been verified experimentally through prompt gamma ray yield measurement as a function of the front moderator thickness. In this study the yield of the 3.54 and 4.94 MeV prompt gamma rays from silicon in a soil sample was measured as a function of thickness of the front moderator of the rectangular moderator. The experimental results were compared with the results of the Monte Carlo simulations. A good agreement has been achieved between the experimental results and the results of the calculations. The experimental results have provided useful information about the PGNAA setup performance, neutron moderation, and gamma ray attenuation in the PGNAA sample.

  3. Validity test of design calculations of a PGNAA setup

    A rectangular moderator has been designed for the prompt gamma ray neutron activation analysis (PGNAA) setup at King Fahd University of Petroleum and Minerals (KFUPM) to analyze Portland cement samples. The design of the moderator assembly was obtained using Monte Carlo calculations. The design calculations of the new rectangular moderator of the KFUPM PGNAA setup have been verified experimentally through prompt gamma ray yield measurement as a function of the front moderator thickness. In this study the yield of the 3.54 and 4.94 MeV prompt gamma rays from silicon in a soil sample was measured as a function of thickness of the front moderator of the rectangular moderator. The experimental results were compared with the results of the Monte Carlo simulations. A good agreement has been achieved between the experimental results and the results of the calculations. The experimental results have provided useful information about the PGNAA setup performance, neutron moderation, and gamma ray attenuation in the PGNAA sample

  4. Acoustic Noise Levels of Dental Equipments and Its Association with Fear and Annoyance Levels among Patients Attending Different Dental Clinic Setups in Jaipur, India

    Ganta, Shravani; Nagaraj, Anup; Pareek, Sonia; Atri, Mansi; Singh, Kushpal; Sidiq, Mohsin

    2014-01-01

    Background: Noise is a source of pervasive occupational hazard for practicing dentists and the patients. The sources of dental sounds by various dental equipments can pose as a potential hazard to hearing system and add to the annoyance levels of the patients. The aim of the study was to analyze the noise levels from various equipments and evaluate the effect of acoustic noise stimulus on dental fear and annoyance levels among patients attending different dental clinic setups in Jaipur, India. Methodology: The sampling frame comprised of 180 patients, which included 90 patients attending 10 different private clinics and 90 patients attending a Dental College in Jaipur. The levels of Acoustic Noise Stimulus originating from different equipments were determined using a precision sound level meter/decibulometer. Dental fear among patients was measured using Dental Fear Scale (DFS). Results: Statistical analysis was performed using chi square test and unpaired t-test. The mean background noise levels were found to be maximum in the pre-clinical setup/ laboratory areas (69.23+2.20). Females and the patients attending dental college setup encountered more fear on seeing the drill as compared to the patients attending private clinics (p<0.001). Conclusion: The sources of dental sounds can pose as a potential hazard to hearing system. It was analyzed that the environment in the clinics can directly have an effect on the fear and annoyance levels of patients. Hence it is necessary control the noise from various dental equipments to reduce the fear of patients from visiting a dental clinic. PMID:24959512

  5. Airflow Test of Acoustic Board Samples

    Jensen, Rasmus Lund; Jensen, Lise Mellergaard

    In the laboratory of Indoor Environmental Engineering, Department of Civil Engineering, Aalborg University an airflow test on 2x10 samples of acoustic board were carried out the 2nd of June 2012. The tests were carried out for Rambøll and STO AG. The test includes connected values of volume flow...

  6. Gas diffusion electrode setup for catalyst testing in concentrated phosphoric acid at elevated temperatures

    Wiberg, Gustav Karl Henrik; Fleige, Michael; Arenz, Matthias

    2015-01-01

    We present a detailed description of the construction and testing of an electrochemical cell setup allowing the investigation of a gas diffusion electrode containing carbon supported high surface area catalysts. The setup is designed for measurements in concentrated phosphoric acid at elevated...

  7. Acoustic Test Characterization of Melamine Foam for Usage in NASA's Payload Fairing Acoustic Attenuation Systems

    Hughes, William O.; McNelis, Anne M.; McNelis, Mark E.

    2014-01-01

    The external acoustic liftoff levels predicted for NASA's future heavy lift launch vehicles are expected to be significantly higher than the environment created by today's commercial launch vehicles. This creates a need to develop an improved acoustic attenuation system for future NASA payload fairings. NASA Glenn Research Center initiated an acoustic test series to characterize the acoustic performance of melamine foam, with and without various acoustic enhancements. This testing was denoted as NEMFAT, which stands for NESC Enhanced Melamine Foam Acoustic Test, and is the subject of this paper. Both absorption and transmission loss testing of numerous foam configurations were performed at the Riverbank Acoustical Laboratory in July 2013. The NEMFAT test data provides an initial acoustic characterization and database of melamine foam for NASA. Because of its acoustic performance and lighter mass relative to fiberglass blankets, melamine foam is being strongly considered for use in the acoustic attenuation systems of NASA's future launch vehicles.

  8. Time reversal signal processing in acoustic emission testing

    Převorovský, Zdeněk; Krofta, Josef; Kober, Jan; Dvořáková, Zuzana; Chlada, Milan

    Brno: University of Technology, 2014. s. 10-11. ISBN 978-80-214-5019-6. [European Conference on Non-Destructive Testing (ECNDT 2014) /11./. 06.10.2014-10.10.2014, Praha] Institutional support: RVO:61388998 Keywords : acoustic emission (AE) * ultrasonic testing (UT) * signal processing * source location * time reversal acoustics * acoustic emission * signal processing and transfer Subject RIV: BI - Acoustics

  9. Evaluation of Reflections in a MIMO OTA Test Setup

    Barrio, Samantha Caporal Del; Franek, Ondrej; Krenz, Gunter; Pedersen, Gert Frølund

    With the commercialization of MIMO devices, accurate over-the-air testing has become a major research area in mobile communications. Several test methods are investigated in the related work. This paper discusses the anechoic chamber method and specifically deals with reflections between probes o...

  10. Validation and Simulation of ARES I Scale Model Acoustic Test -1- Pathfinder Development

    Putnam, G. C.

    2011-01-01

    The Ares I Scale Model Acoustics Test (ASMAT) is a series of live-fire tests of scaled rocket motors meant to simulate the conditions of the Ares I launch configuration. These tests have provided a well documented set of high fidelity measurements useful for validation including data taken over a range of test conditions and containing phenomena like Ignition Over-Pressure and water suppression of acoustics. To take advantage of this data, a digital representation of the ASMAT test setup has been constructed and test firings of the motor have been simulated using the Loci/CHEM computational fluid dynamics software. Within this first of a series of papers, results from ASMAT simulations with the rocket in a held down configuration and without water suppression have then been compared to acoustic data collected from similar live-fire tests to assess the accuracy of the simulations. Detailed evaluations of the mesh features, mesh length scales relative to acoustic signals, Courant-Friedrichs-Lewy numbers, and spatial residual sources have been performed to support this assessment. Results of acoustic comparisons have shown good correlation with the amplitude and temporal shape of pressure features and reasonable spectral accuracy up to approximately 1000 Hz. Major plume and acoustic features have been well captured including the plume shock structure, the igniter pulse transient, and the ignition overpressure. Finally, acoustic propagation patterns illustrated a previously unconsidered issue of tower placement inline with the high intensity overpressure propagation path.

  11. Setup, tests and results for the ATLAS TileCal Read Out Driver production

    Valero, Alberto; Castillo, V; Cuenca, C; Ferrer, A; Fullana, E; González, V; Higón, E; Munar, A; Poveda, J; Ruiz-Martínez, A; Salvachúa, B; Sanchís, E; Solans, C; Soret, J; Torres, J; Valls, J A

    2007-01-01

    In this paper we describe the performance and test results of the production of the 38 ATLAS TileCal Read Out Drivers (RODs). We first describe the basic hardware specifications and firmware functionality of the modules, the test-bench setup used for production and the test procedure to qualify the boards. We then finally show and discuss the performance results.

  12. Nonlinear acoustic nondestructive testing for concrete durability

    Wu, Hwai-Chung; Warnemuende, Kraig

    2000-06-01

    Several nondestructive testing methods can be used to determine the damage in a concrete structure. Linear ultrasonic techniques, e.g. pulse-velocity and amplitude attenuation, are very common in nondestructive evaluation. Velocity of propagation is not very sensitive to the degrees of damage unless a great deal of micro-damage having evolving into localized macro-damage. This transition typically takes place around 80% of the ultimate compressive strength. Amplitude attenuation is potentially more sensitive than pulse-velocity. However, this method depends strongly on the coupling conditions between transducers and concrete, hence unreliable. A baseline test of the linear acoustics of several mortar samples was conducted. These mortar samples have been previously damaged to different levels. Several other testing methods were also performed on the same samples to form a comparison. The focus is in comparing the sensitivity of a new testing method (Non-linear Acoustic NDE) with several more traditional testing methods. Non-linearity of the material stiffness is expressed in non-linear acoustics as the effect that damage and flaws have on the modulation of a signal as it propagates through the material. Spectral (non-linear) analysis is much more sensitive to lower damage states and less dependent on the repeatability of the coupling of the transducers.

  13. Development of a grinding-specific performance test set-up

    Olesen, C. G.; Larsen, B. H.; Andresen, E. L.;

    2015-01-01

    The aim of this study was to develop a performance test set-up for America's Cup grinders. The test set-up had to mimic the on-boat grinding activity and be capable of collecting data for analysis and evaluation of grinding performance. This study included a literature-based analysis of grinding...... an exponentially rising resistance. A custom-made grinding ergometer was developed with computer-controlled resistance and capable of collecting data during the test. The data collected can be used to find measures of grinding performance such as peak power, time to complete and the decline in...... repeated grinding performance....

  14. Acoustic emission non-destructive testing of structures using source location techniques.

    Beattie, Alan G.

    2013-09-01

    The technology of acoustic emission (AE) testing has been advanced and used at Sandia for the past 40 years. AE has been used on structures including pressure vessels, fire bottles, wind turbines, gas wells, nuclear weapons, and solar collectors. This monograph begins with background topics in acoustics and instrumentation and then focuses on current acoustic emission technology. It covers the overall design and system setups for a test, with a wind turbine blade as the object. Test analysis is discussed with an emphasis on source location. Three test examples are presented, two on experimental wind turbine blades and one on aircraft fire extinguisher bottles. Finally, the code for a FORTRAN source location program is given as an example of a working analysis program. Throughout the document, the stress is on actual testing of real structures, not on laboratory experiments.

  15. Subscale Acoustic Testing: Comparison of ALAT and ASMAT

    Houston, Janice D.; Counter, Douglas

    2014-01-01

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

  16. Time reversal signal processing in acoustic emission testing

    Převorovský, Zdeněk; Krofta, Josef; Kober, Jan; Dvořáková, Zuzana; Chlada, Milan; Dos Santos, S.

    2014-01-01

    Roč. 19, č. 12 (2014). ISSN 1435-4934. [European Conference on Non-Destructive Testing (ECNDT 2014) /11./. Praha, 06.10.2014-10.10.2014] Institutional support: RVO:61388998 Keywords : acoustic emission (AE) * ultrasonic testing (UT) * signal processing * source location * time reversal acoustics * acoustic emission * signal processing and transfer Subject RIV: BI - Acoustics http://www.ndt.net/events/ECNDT2014/app/content/Slides/637_Prevorovsky.pdf

  17. Emulating Ray-Tracing Channels in Multi-probe Anechoic Chamber Setups for Virtual Drive Testing

    Fan, Wei; Llorente, Ines Carton; Kyösti, Pekka;

    2016-01-01

    This paper discusses virtual drive testing (VDT) for multiple-input multiple-output (MIMO) capable terminals in multi-probe anechoic chamber (MPAC) setups. We propose to perform VDT, via reproducing ray tracing (RT) simulated channels with the field synthesis technique. Simulation results...

  18. Design of Testing Set-up for Nuclear Fuel Rod by Neutron Radiography at CARR

    WEI; Guo-hai; HAN; Song-bai; WANG; Hong-li; HAO; Li-jie; WU; Mei-mei; HE; Lin-feng; WANG; Yu; LIU; Yun-tao; SUN; Kai; CHEN; Dong-feng

    2012-01-01

    <正>An experimental set-up dedicated to non-destructively test a 15 cm long pressurized water reactor (PWR) nuclear fuel rod by neutron radiography (NR) is designed and fabricated. It consists of three parts: Transport container, imaging block and steel support. The design of the transport container was optimized with Monte-Carlo simulation by the MCNP code.

  19. Advanced Test Method of Solid Oxide Cells in a Plug-Flow Setup

    Jensen, Søren Højgaard; Hauch, Anne; Hendriksen, Peter Vang;

    2009-01-01

    This paper describes a case study of two electrolysis tests of solid oxide cells [Ni/yttria-stabilized zirconia (YSZ)-YSZ-lanthanum strontium manganite (LSM)/YSZ] tested in a plug-flow setup. An extensively instrumented cell test setup was used, and the tests involved measurements of the cell...... impedance at open-circuit voltage and under current load, the cell voltage, and the in-plane voltage in the electrodes. From the cell-voltage measurements it was evident that a significant passivation of the cells occurred over the first similar to 10 days. Thereafter, the cells reactivated at constant......-circuit voltage before and after electrolysis testing at various gas compositions were used to show that the Ni electrode was affected by the electrolysis operation, whereas the LSM electrode was not....

  20. Development and Test of a Neutron Imaging Setup at the PGAA Instrument at FRM II

    Söllradl, S.; Mühlbauer, M. J.; Kudejova, P.; Türler, A.

    We report on the developments of a neutron tomography setup at the instrument for prompt gamma-ray activation analysis (PGAA) at the Maier-Leibnitz Zentrum(MLZ). The recent developments are driven by the idea of combining the spatial information obtained with neutron tomography with the elemental information determined with PGAA, i.e. to further combine both techniques to an investigative technique called prompt gamma activation imaging (PGAI).At the PGAA instrument, a cold neutron flux of up to 6 x 1010 cm-2 s-1 (thermal equivalent) is available in the focus of an elliptically tapered neutron guide. In the reported experiments, the divergence of the neutron beam was investigated, the resolution of the installed detector system tested, and a proof-of-principle tomography experiment performed. In our study a formerly used camera box was upgraded with a better camera and an optical resolution of 8 line pairs/mm was achieved. The divergence of the neutron beam was measured by a systematic scan along the beam axis. Based on the acquired data, a neutron imaging setup with a L/D ratio of 200 was installed. The resolution of the setup was testedin combination with a gadolinium test target and different scintillator screens. The test target was irradiated at two positions to determine the maximum resolution and the resolution at the actual sample position. The performance of the installed tomography setup was demonstrated bya tomography experiment of an electric amplifier tube.

  1. TEST BEAM COORDINATION: The 2004 Test Beam Calorimetry set-up in H8

    Aleksa, M; Di Girolamo, B; Ferrari, C; Giugni, D; Santoni, C; Wingerter, I

    A new table has been designed, built and finally mounted to position the LAr cryostat in front of the Tilecal modules. The new table has been connected to the existing Tilecal table to be able to move the full set-up along eta values between 0 and 1.2. The table has been conceived by D. Giugni (INFN Milano and now CERN PH) and modeled by G. Braga (INFN Milano) in spring-summer 2003. The realization of the table has been done by an Italian firm (MatecImpianti, Fenegrò, Como) under the supervision of S. Coelli (INFN Milano) starting August 2003. Figure 1 shows the table assembled at the firm (left). Figure 1: The Tilecal-LAr table: in Fenegro (left) and at CERN (right). In November 2003 the table has been delivered to CERN and put in temporary storage to be assembled after the preparation of the Tilecal zone. In February 2004 two technicians from the firm and the team of technician coordinated by C. Ferrari (CERN AB/ATB), assembled, tested and commissioned the table under the supervision of S. Coelli...

  2. Benchmark test cases for evaluation of computer-based methods for detection of setup errors: realistic digitally reconstructed electronic portal images with known setup errors

    Purpose: The purpose of this investigation was to develop methods and software for computing realistic digitally reconstructed electronic portal images with known setup errors for use as benchmark test cases for evaluation and intercomparison of computer-based methods for image matching and detecting setup errors in electronic portal images. Methods and Materials: An existing software tool for computing digitally reconstructed radiographs was modified to compute simulated megavoltage images. An interface was added to allow the user to specify which setup parameter(s) will contain computer-induced random and systematic errors in a reference beam created during virtual simulation. Other software features include options for adding random and structured noise, Gaussian blurring to simulate geometric unsharpness, histogram matching with a 'typical' electronic portal image, specifying individual preferences for the appearance of the 'gold standard' image, and specifying the number of images generated. The visible male computed tomography data set from the National Library of Medicine was used as the planning image. Results: Digitally reconstructed electronic portal images with known setup errors have been generated and used to evaluate our methods for automatic image matching and error detection. Any number of different sets of test cases can be generated to investigate setup errors involving selected setup parameters and anatomic volumes. This approach has proved to be invaluable for determination of error detection sensitivity under ideal (rigid body) conditions and for guiding further development of image matching and error detection methods. Example images have been successfully exported for similar use at other sites. Conclusions: Because absolute truth is known, digitally reconstructed electronic portal images with known setup errors are well suited for evaluation of computer-aided image matching and error detection methods. High-quality planning images, such as

  3. Acoustic emission monitoring of HFIR vessel during hydrostatic testing

    This report discusses the results and conclusions reached from applying acoustic emission monitoring to surveillance of the High Flux Isotope Reactor vessel during pressure testing. The objective of the monitoring was to detect crack growth and/or fluid leakage should it occur during the pressure test. The report addresses the approach, acoustic emission instrumentation, installation, calibration, and test results

  4. Acoustic Test Results of Melamine Foam with Application to Payload Fairing Acoustic Attenuation Systems

    Hughes, William O.; McNelis, Anne M.

    2014-01-01

    A spacecraft at launch is subjected to a harsh acoustic and vibration environment resulting from the passage of acoustic energy, created during the liftoff of a launch vehicle, through the vehicle's payload fairing. In order to ensure the mission success of the spacecraft it is often necessary to reduce the resulting internal acoustic sound pressure levels through the usage of acoustic attenuation systems. Melamine foam, lining the interior walls of the payload fairing, is often utilized as the main component of such a system. In order to better understand the acoustic properties of melamine foam, with the goal of developing improved acoustic attenuation systems, NASA has recently performed panel level testing on numerous configurations of melamine foam acoustic treatments at the Riverbank Acoustical Laboratory. Parameters assessed included the foam's thickness and density, as well as the effects of a top outer cover sheet material and mass barriers embedded within the foam. This testing followed the ASTM C423 standard for absorption and the ASTM E90 standard for transmission loss. The acoustic test data obtained and subsequent conclusions are the subjects of this paper.

  5. PC based manual and safety logic card test setup for 235 MWe PHWRs

    Fuel handling controls for 235 MWe PHWR make use of Manual and Logic cards (MLCs) for providing safety interlocks. These cards consist of various type of logic blocks. By connecting these logic blocks all the safety interlocks required for fuel handling controls have been provided. Previously trouble shooting of these cards was done by means of logic probe. Since the method was manual, it was laborious and time consuming. PC based test setup has overcome this drawback and detects the fault at the component level within few seconds. It also gives printout of status of faulty MLC cards. Here motherboard has been designed having slots for insertion of MLC cards. The input/output connection of these cards are coming to two 50 pin FRC connectors. PC communicates through 144 line digital input/output card with MLC card under test. Software is user friendly and outputs suitable input patterns to the card under test and checks for output pattern. It compares this output pattern with compare pattern and detects the fault and displays the symptoms. This system is currently in use at test facility for fuelling machine for 235 MWe PHWR reactor at Refuelling Technology Division, Hall-7. This test setup has been proposed for use at NAPP and future reactors. (author). 4 figs., 1 annexure

  6. On Probe Weighting for MIMO OTA testing in Anechoic Chamber Setups

    Fan, Wei; Kyösti, Pekka; Nuutinen, Jukka-Pekka; Nielsen, Jesper Ødum; Pedersen, Gert F.

    The multi-probe anechoic chamber method is promising for OTA testing. The reason can be attributed to its potential for enabling evaluating MIMO terminals in realistic environments. The focus of the paper is on investigating how to create desired spatial channel models with the multi-probe anechoic...... chamber setups. Simulation results have shown that with the discussed methods, the number of probes and probe power weights determine to which level the spatial characteristics of the target channel models can be accurately approximated. With the optimized weights, better agreement is achieved for all...

  7. Acoustic emission generated during scratch test of various thin films

    Boháč, Petr; Tomáštík, J.; Čtvrtlík, R.; Dráb, M.; Koula, V.; Cvrk, K.; Jastrabík, Lubomír

    2014-01-01

    Roč. 19, č. 12 (2014), s. 16635. ISSN 1435-4934 R&D Projects: GA TA ČR TA03010743 Institutional support: RVO:68378271 Keywords : acoustic emission * scratch test * thin films * AE data analysis * mechanical toughness Subject RIV: BI - Acoustic s

  8. Laser-induced transient grating setup with continuously tunable period

    Vega-Flick, A. [Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Applied Physics Department, CINVESTAV-Unidad Mérida, Carretera Antigua a Progreso Km 6, Cordemex, Mérida, Yucatán 97310 Mexico (Mexico); Eliason, J. K.; Maznev, A. A.; Nelson, K. A., E-mail: kanelson@mit.edu [Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Khanolkar, A.; Abi Ghanem, M.; Boechler, N. [Department of Mechanical Engineering, University of Washington, Seattle, Washington 98195 (United States); Alvarado-Gil, J. J. [Applied Physics Department, CINVESTAV-Unidad Mérida, Carretera Antigua a Progreso Km 6, Cordemex, Mérida, Yucatán 97310 Mexico (Mexico)

    2015-12-15

    We present a modification of the laser-induced transient grating setup enabling continuous tuning of the transient grating period. The fine control of the period is accomplished by varying the angle of the diffraction grating used to split excitation and probe beams. The setup has been tested by measuring dispersion of bulk and surface acoustic waves in both transmission and reflection geometries. The presented modification is fully compatible with optical heterodyne detection and can be easily implemented in any transient grating setup.

  9. Laser-induced transient grating setup with continuously tunable period

    We present a modification of the laser-induced transient grating setup enabling continuous tuning of the transient grating period. The fine control of the period is accomplished by varying the angle of the diffraction grating used to split excitation and probe beams. The setup has been tested by measuring dispersion of bulk and surface acoustic waves in both transmission and reflection geometries. The presented modification is fully compatible with optical heterodyne detection and can be easily implemented in any transient grating setup

  10. Application of acoustic emission in pressure vessel testing

    Materials of the CrMoV and the NiCrMoV types were tested for integrity using an acoustic emission method developed by SKODA Trust. The materials are used for the production of reactor pressure vessels. The acoustic emission method is employed for determining the beginning of crack formation and crack proliferation. The objective of the tests was to obtain information necessary for evaluating acoustic emission sources in actual components. The use is discussed of a 24-channel system by Trodyne (USA) for testing the integrity of WWER type pressure vessels manufactured by SKODA. (B.S.)

  11. Multiple sample setup for testing the hydrothermal stability of adsorbents in thermal energy storage applications

    Thermal energy storage based on adsorption and desorption of water on an adsorbent can achieve high energy storage densities. Many adsorbents lose adsorption capacity when operated under unfavourable hydrothermal conditions during adsorption and desorption. The stability of an adsorbent against stressing hydrothermal conditions is a key issue for its usability in adsorption thermal energy storage. We built an experimental setup that simultaneously controls the hydrothermal conditions of 16 samples arranged in a matrix of four temperatures and four water vapour pressures. This setup allows the testing of potential adsorbents between temperatures of 50 °C and 350 °C and water vapour pressures of up to 32 kPa. A measurement procedure that allows the detection of the hydrothermal stability of an adsorbent after defined time spans has been designed. We verified the functionality of the multiple sample measurements with a microporous adsorbent, a zeolite NaMSX. The hydrothermal stability of this zeolite is tested by water uptake measurements. A standard deviation lower than 1% of the 16 samples for detecting the hydrothermal stability enables setting different conditions in each sample cell. Further, we compared the water uptake measurements by measuring their adsorption isotherms with the volumetric device BELSORP Aqua 3 from Bel Japan. (paper)

  12. High-temperature acoustic test facilities and methods

    Pearson, Jerome

    1994-09-01

    The Wright Laboratory is the Air Force center for air vehicles, responsible for developing advanced technology and incorporating it into new flight vehicles and for continuous technological improvement of operational air vehicles. Part of that responsibility is the problem of acoustic fatigue. With the advent of jet aircraft in the 1950's, acoustic fatigue of aircraft structure became a significant problem. In the 1960's the Wright Laboratory constructed the first large acoustic fatigue test facilities in the United States, and the laboratory has been a dominant factor in high-intensity acoustic testing since that time. This paper discusses some of the intense environments encountered by new and planned Air Force flight vehicles, and describes three new acoustic test facilities of the Wright Laboratory designed for testing structures in these dynamic environments. These new test facilities represent the state of the art in high-temperature, high-intensity acoustic testing and random fatigue testing. They will allow the laboratory scientists and engineers to test the new structures and materials required to withstand the severe environments of captive-carry missiles, augmented lift wings and flaps, exhaust structures of stealth aircraft, and hypersonic vehicle structures well into the twenty-first century.

  13. Design and test of a flexible electrochemical setup for measurements in aqueous electrolyte solutions at elevated temperature and pressure

    Wiberg, Gustav K. H.; Fleige, Michael J.; Arenz, Matthias

    2014-08-01

    We present a detailed description of the construction and testing of an electrochemical cell allowing measurements at elevated temperature and pressure. The cell consists of a stainless steel pressure vessel containing the electrochemical glass cell exhibiting a three electrode configuration. The design of the working electrode is inspired by conventional rotating disk electrode setups. As demonstrated, the setup can be used to investigate temperature dependent electrochemical processes on polycrystalline platinum and also high surface area type electrocatalysts.

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

    Counter, Douglas D.; Houston, Janice D.

    2012-01-01

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

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

    Counter, Douglas D.; Houston, Janice D.

    2012-01-01

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

  16. Test Setup for Anechoic Room based MIMO OTA Testing of LTE Terminals

    Carreño, Xavier; Fan, Wei; Nielsen, Jesper Ødum;

    2013-01-01

    introduced into, for example, LTE andWiMAX systems. The main purpose of this testing is to validate that the user equipment will have a good performance in real use. CTIA, 3GPP and COST are spending a big effort in standardizing the OTA testing procedure which is much more complex than similar SISO OTA...

  17. The Testing Behind The Test Facility: The Acoustic Design of the NASA Glenn Research Center's World-Class Reverberant Acoustic Test Facility

    Hozman, Aron D.; Hughes, William O.; McNelis, Mark E.; McNelis, Anne M.

    2011-01-01

    The National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) is leading the design and build of the new world-class vibroacoustic test capabilities at the NASA GRC's Plum Brook Station in Sandusky, Ohio, USA. Benham Companies, LLC is currently constructing modal, base-shake sine and reverberant acoustic test facilities to support the future testing needs of NASA's space exploration program. The large Reverberant Acoustic Test Facility (RATF) will be approximately 101,000 cu ft in volume and capable of achieving an empty chamber acoustic overall sound pressure level (OASPL) of 163 dB. This combination of size and acoustic power is unprecedented amongst the world's known active reverberant acoustic test facilities. The key to achieving the expected acoustic test spectra for a range of many NASA space flight environments in the RATF is the knowledge gained from a series of ground acoustic tests. Data was obtained from several NASA-sponsored test programs, including testing performed at the National Research Council of Canada's acoustic test facility in Ottawa, Ontario, Canada, and at the Redstone Technical Test Center acoustic test facility in Huntsville, Alabama, USA. The majority of these tests were performed to characterize the acoustic performance of the modulators (noise generators) and representative horns that would be required to meet the desired spectra, as well as to evaluate possible supplemental gas jet noise sources. The knowledge obtained in each of these test programs enabled the design of the RATF sound generation system to confidently advance to its final acoustic design and subsequent on-going construction.

  18. Very high stability systems: LMJ target alignment system and MTG imager test setup

    Compain, Eric; Maquet, Philippe; Kunc, Thierry; Marque, Julien; Lauer-Solelhac, Maxime; Delage, Laurent; Lanternier, Catherine

    2015-09-01

    Most of space instruments and research facilities require test equipment with demanding opto-mechanical stability. In some specific cases, when the stability performance directly drives the final performance of the scientific mission and when feasibility is questionable, specific methods must be implemented for the associated technical risk management. In present paper, we will present our heritage in terms of methodology, design, test and the associated results for two specific systems : the SOPAC-POS and the MOTA, generating new references for future developments. From a performance point of view, we will emphasis on following key parameters : design symmetry, thermal load management, and material and structural choices. From a method point of view the difficulties arise first during design, from the strong coupling between the thermal, mechanical and optical performance models, and then during testing, from the difficulty of conceiving test setup having appropriate performance level. We will present how these limitations have been overcome. SOPAC-POS is the target alignment system of the LMJ, Laser Mega Joule, the French inertial confinement fusion research center. Its stability has been demonstrated by tests in 2014 after 10 years of research and development activities, achieving 1μm stability @ 6m during one hour periods. MOTA is an Optical Ground Support Equipment aiming at qualifying by tests the Flexible Combined Imager (FCI). FCI is an instrument for the meteorological satellite MTG-I, a program of and funded by the European Space Agency and under prime contractorship of Thales Alenia Space. Optimized design will allow to get better than 0.2 μrad stability for one hour periods, as required for MTF measurement.

  19. Comparison of Two High Intensity Acoustic Test Facilities

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

    2004-08-01

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

  20. Acoustics

    Goodman, Jerry R.; Grosveld, Ferdinand

    2007-01-01

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

  1. Study of the Switching Errors in an RSFQ Switch by Using a Computerized Test Setup

    Kim, Se Hoon; Baek, Seung Hun; Yang, Jung Kuk; Kim, Jun Ho; Kang, Joon Hee [Incheon Univesity, Incheon (Korea, Republic of)

    2005-10-15

    The problem of fluctuation-induced digital errors in a rapid single flux quantum (RSFQ) circuit has been a very important issue. In this work, we calculated the bit error rate of an RSFQ switch used in superconductive arithmetic logic unit (ALU). RSFQ switch should have a very low error rate in the optimal bias. Theoretical estimates of the RSFQ error rate are on the order of 10{sup -50}per bit operation. In this experiment, we prepared two identical circuits placed in parallel. Each circuit was composed of 10 Josephson transmission lines (JTLs) connected in series with an RSFQ switch placed in the middle of the 10 JTLs. We used a splitter to feed the same input signal to both circuits. The outputs of the two circuits were compared with an RSFQ exclusive OR (XOR) to measure the bit error rate of the RSFQ switch. By using a computerized bit-error-rate test setup, we measured the bit error rate of 2.18 x 10{sup -12} when the bias to the RSFQ switch was 0.398 mA that was quite off from the optimum bias of 0.6 mA.

  2. Study of the Switching Errors in an RSFQ Switch by Using a Computerized Test Setup

    The problem of fluctuation-induced digital errors in a rapid single flux quantum (RSFQ) circuit has been a very important issue. In this work, we calculated the bit error rate of an RSFQ switch used in superconductive arithmetic logic unit (ALU). RSFQ switch should have a very low error rate in the optimal bias. Theoretical estimates of the RSFQ error rate are on the order of 10-50per bit operation. In this experiment, we prepared two identical circuits placed in parallel. Each circuit was composed of 10 Josephson transmission lines (JTLs) connected in series with an RSFQ switch placed in the middle of the 10 JTLs. We used a splitter to feed the same input signal to both circuits. The outputs of the two circuits were compared with an RSFQ exclusive OR (XOR) to measure the bit error rate of the RSFQ switch. By using a computerized bit-error-rate test setup, we measured the bit error rate of 2.18 x 10-12 when the bias to the RSFQ switch was 0.398 mA that was quite off from the optimum bias of 0.6 mA.

  3. Early diagnosis of acoustic neuroma by the vestibular test

    Haid, T.; Rettinger, G.; Berg, M.; Wigand, M.E.

    1981-11-01

    In a series of 390 cases with suspicion of acoustic neurinomas 78 such tumors could be diagnosed, including 12 early stage neurinomas. This relatively high detection quote of small neurinomas is due to a special diagnostical programme: Every patient with unilateral and sensoneural hearingloss, independent of vertigo anamnesis or of the result of X-rays must be further examined by a vestibular test. All 78 patients with acoustic neuroma had pathological vestibular findings. The positional test turned out to be the most sensitive examination in the early diagnosis of acoustic neuromas and yields a still higher incidence than the thermic test: 95% of the patients with a neuroma showed pathological findings in the positional test. Every patient suffering from an unidentified unilateral and sensoneural hearingloss combined with a pathological result in the positional test must be further checked by a cisternomeatography or computerized tomography using airinsufflation. Every fifth of these patients showed typical signs of an acoustic neuroma in the neuroradiological tests. 68 neuromas are operated today and verfied histologically, 10 patients are still waiting for surgical treatment.

  4. The experimental setup of a large field operational test for cooperative driving vehicles at the A270

    Broek, T.H.A. van den; Netten, B.D.; Hoedemaeker, M.; Ploeg, J.

    2010-01-01

    In this paper, a large field operational test (FOT) for cooperative driving systems, which take place on a public highway, is discussed. The experimental setup consist of a specific driver support system, which is closely related to cooperative adaptive cruise control (CACC) systems. Instead of auto

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

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

  6. An Evaluation of the Additional Acoustic Power Needed to Overcome the Effects of a Test-Article's Absorption during Reverberant Chamber Acoustic Testing of Spaceflight Hardware

    Hozman, Aron D.; Hughes, William O.

    2014-01-01

    The exposure of a customers aerospace test-article to a simulated acoustic launch environment is typically performed in a reverberant acoustic test chamber. The acoustic pre-test runs that will ensure that the sound pressure levels of this environment can indeed be met by a test facility are normally performed without a test-article dynamic simulator of representative acoustic absorption and size. If an acoustic test facilitys available acoustic power capability becomes maximized with the test-article installed during the actual test then the customers environment requirement may become compromised. In order to understand the risk of not achieving the customers in-tolerance spectrum requirement with the test-article installed, an acoustic power margin evaluation as a function of frequency may be performed by the test facility. The method for this evaluation of acoustic power will be discussed in this paper. This method was recently applied at the NASA Glenn Research Center Plum Brook Stations Reverberant Acoustic Test Facility for the SpaceX Falcon 9 Payload Fairing acoustic test program.

  7. Development of a Penning trap based set-up for precision tests of the standard model.

    Delauré, Bavo

    This work has presented the development and realization of the WITCH set-up, which is designed to measure the recoil energy spectrum of the daughter ions originating in nuclear -decay. The spectral shape reveals the angular correlation between the neutrino and the -particle, which is sensitive to the nature of the weak interaction, i.e. possible scalar or tensor type contributions. In order to allow detection of the low energy recoil ions, the set-up is equipped with a Penning trap which is in principle able to confine ions of each element in a scattering free environment. This storage device for the radioactive source is coupled to a retardation spectrometer, which performs the energy analysis of the recoil ions and has a solid angle acceptance of almost 2. The setup is installed at the ISOLDE/CERN facility. At present, the set-up installation is close to completion and commissioning of the apparatus has started. A first experiment with a radioactive beam is planned for the second half of 2004. In order to c...

  8. Benchmark test cases for evaluation of computer-based methods for detection of setup errors: realistic digitally reconstructed electronic portal images with known setup errors

    Purpose/Objective: The potential for on-line error detection using electronic portal images (EPIs) has stimulated the investigation of computer-based methods for matching portal images with reference or 'gold standard' images. The lack of absolute truth for clinical images is a major obstacle to the evaluation of these methods. The purpose of this investigation was to create a set of realistic test EPIs with known setup errors for use as a benchmark for evaluation and intercomparison of computer-based methods, including automatic and user-guided techniques, for EPI analysis. Materials and Methods: Digitally reconstructed electronic portal images (DREPIs) were computed using the visible male CT data set from the National Library of Medicine (NLM). (DREPIs are computed using high energy attenuation coefficients to simulate megavoltage images.) The NLM CT data set comprises 512x512x1 mm contiguous slices from the tip of the head to below the knees. The subject was frozen and scanned very soon after non-traumatizing death, and thus the visualized anatomy closely resembles that of a living person, but without breathing and other motion artifacts. Also since dose was not a consideration the signal-to-noise ratio is higher compared with typical 1 mm slices obtained on a living person. Because of the quality of the CT data, the quality of the DREPIs had to be degraded, and modified in other ways, to create realistic test cases. Modifications included: 1) contrast histogram matching to actual EPIs, 2) addition of structured noise by blending an 'open field' EPI image with the DREPI, 3) addition of random unstructured noise, and 4) Gaussian blurring to simulate patient motion and head scatter effects. (It is important to note that there is no standard appearance or quality for EPIs. The appearance of EPIs is quite variable, especially across EPIDs from different manufacturers. Even for a given system, EPIs are quite sensitive to system calibration and acquisition parameters

  9. Acoustic Emission Defects Localized by Means of Geodetic Iterative Procedure - Algorithms, Tests, AE Experiment

    Kůs, V.; Záveský, M.; Převorovský, Zdeněk

    Granada : University of Granada, 2012 - (Gallego, A.; Ono, K.), s. 1-12 ISBN 978-84-615-9941-7. [Europen Conference on Acoustic Emission Testing/30./ & International Conference on Acoustic Emission/7./. Granada (ES), 12.09.2012-15.09.2012] Institutional support: RVO:61388998 Keywords : acoustic emissio * geodesic * Newton -Raphson method * iterative source localization Subject RIV: BI - Acoustics

  10. Could Acoustic Emission Testing Show a Pipe Failure in Advance?

    Soares, S. D.; Teixeira, J. C. G.

    2004-02-01

    During the last 20 years PETROBRAS has been attempting to use Acoustic Emission (AE) as an inspection tool. In this period the AE concept has changed from a revolutionary method to a way of finding areas to make a complete inspection. PETROBRAS has a lot of pressure vessels inspected by AE and with other NDTs techniques to establish their relationship. In other hand, PETROBRAS R&D Center has conducted destructive hydrostatic tests in pipelines samples with artificial defects made by milling. Those tests were monitored by acoustic emission and manual ultrasonic until the complete failure of pipe sample. This article shows the results obtained and a brief proposal of analysis criteria for this environment of test.

  11. Acoustic flight tests of rotorcraft noise-abatement approaches using local differential GPS guidance

    Chen, Robert T. N.; Hindson, William S.; Mueller, Arnold W.

    1995-01-01

    This paper presents the test design, instrumentation set-up, data acquisition, and the results of an acoustic flight experiment to study how noise due to blade-vortex interaction (BVI) may be alleviated. The flight experiment was conducted using the NASA/Army Rotorcraft Aircrew Systems Concepts Airborne Laboratory (RASCAL) research helicopter. A Local Differential Global Positioning System (LDGPS) was used for precision navigation and cockpit display guidance. A laser-based rotor state measurement system on board the aircraft was used to measure the main rotor tip-path-plane angle-of-attack. Tests were performed at Crows Landing Airfield in northern California with an array of microphones similar to that used in the standard ICAO/FAA noise certification test. The methodology used in the design of a RASCAL-specific, multi-segment, decelerating approach profile for BVI noise abatement is described, and the flight data pertaining to the flight technical errors and the acoustic data for assessing the noise reduction effectiveness are reported.

  12. Development and Test of a Neutron Imaging Setup at the PGAA Instrument at FRM II

    Söllradl, S.; Mühlbauer, M. J.; Kudejova, P.; Türler, Andreas

    2015-01-01

    We report on the developments of a neutron tomography setup at the instrument for prompt gamma-ray activation analysis (PGAA) at the Maier-Leibnitz Zentrum(MLZ). The recent developments are driven by the idea of combining the spatial information obtained with neutron tomography with the elemental information determined with PGAA, i.e. to further combine both techniques to an investigative technique called prompt gamma activation imaging (PGAI).At the PGAA instrument, a cold neutron flux of up...

  13. Acoustic tests of Lorentz symmetry using Bulk Acoustic Wave quartz oscillators

    Goryachev, M; Haslinger, Ph; Mizrachi, E; Anderegg, L; Müller, H; Hohensee, M; Tobar, M E

    2016-01-01

    A new method of probing Lorentz invariance in the neutron sector is described. The method is baed on stable quartz bulk acoustic wave oscillators compared on a rotating table. Due to Lorentz-invariance violation, the resonance frequencies of acoustic wave resonators depend on the direction in space via a corresponding dependence of masses of the constituent elements of solids. This dependence is measured via observation of oscillator phase noise built around such devices. The first such experiment now shows sensitivity to violation down to the limit $\\tilde{c}^n_Q=(-1.8\\pm2.2)\\times 10^{-14}$ GeV. Methods to improve the sensitivity are described together with some other applications of the technology in tests of fundamental physics.

  14. Acoustic events during fatigue test of structural steels

    Acoustic emission sensors were applied recording noises during low cycle fatigue tests in steel materials. The test specimens were machined from the base metal (15H2MFA) and the anticorrosive cladding metal (08H18N10T) of the VVER-440/V-213 (Russian designed PWR) reactor pressure vessel. During the first period, the measurements were carried out with isothermal condition at 260 C on GLEEBLE 3800 servo-hydraulic thermal-mechanical simulator. The tests were run under uniaxial tension-compression loading with total strain control. The programmed waveform was triangular for all the fatigue tests with the frequency of 0.08 Hz. The cyclic loading was started from the compressed side. It was observed that besides rare acoustic emission events regular 10 msec Acoustic Barkhausen Noise (ABN) burst were recorded due to 50Hz AC current drive for heating and maintaining the constant temperature. The amplitude of MABN was higher under pressure than during relaxing and drawing-out by a factor of 2-5. We have carried out also thermo-mechanical fatigue experiment with the same strain-controlled mechanical cycle and simultaneous thermal cycle between 150 C and 270 C. The total number of cycles was terminated, when the force level necessary for the original elongation had been reduced to 75% of its original value. Visual examination showed always some at least surface cracks after stopping the fatigue test. ABN events registered during the beginning cycle exhibited different spectra from the middle and especially from the last cycles before the end of the test, where also double ABN bursts could be recorded. At the end of the test explicit AE events could be found by a new technique. The most interesting result is the possibility to use ABN for testing reactor materials, which could have practical application for fatigue testing.

  15. Utilization of acoustic emission in scratch test evaluation

    Tomáštík, J.; Čtvrtlík, Radim; Boháč, Petr; Dráb, M.; Koula, V.; Cvrk, K.; Jastrabík, Lubomír

    Pfafficon: Trans Tech Publications Ltd, 2015 - (Kovalčíková, A.; Lofaj, F.), s. 119-122 ISBN 978-3-03835-555-7. ISSN 1662-9795. [Conference on Local Mechanical Properties (LMP 2014) /11./. Stará Lesná (SK), 12.11.2014-14.11.2014] R&D Projects: GA TA ČR TA03010743 Institutional support: RVO:68378271 Keywords : acoustic emission * scratch test * thin films Subject RIV: JK - Corrosion ; Surface Treatment of Materials

  16. NASA Engineering and Safety Center (NESC) Enhanced Melamine (ML) Foam Acoustic Test (NEMFAT)

    McNelis, Anne M.; Hughes, William O.; McNelis, Mark E.

    2014-01-01

    The NASA Engineering and Safety Center (NESC) funded a proposal to achieve initial basic acoustic characterization of ML (melamine) foam, which could serve as a starting point for a future, more comprehensive acoustic test program for ML foam. A project plan was developed and implemented to obtain acoustic test data for both normal and enhanced ML foam. This project became known as the NESC Enhanced Melamine Foam Acoustic Test (NEMFAT). This document contains the outcome of the NEMFAT project.

  17. Acoustic interactions between an altitude test facility and jet engine plumes: Theory and experiments

    Ahuja, K. K.; Jones, R. R., III; Tam, C. K.; Massey, K. C.; Fleming, A. J.

    1992-01-01

    The overall objective of the described effort was to develop an understanding of the physical mechanisms involved in the flow/acoustic interactions experienced in full-scale altitude engine test facilities. This is done by conducting subscale experiments and through development of a theoretical model. Model cold jet experiments with an axisymmetric convergent nozzle are performed in a test setup that stimulates a supersonic jet exhausting into a cylindrical diffuser. The measured data consist of detailed flow visualization data and acoustic spectra for a free and a ducted plume. It is shown that duct resonance is most likely responsible by theoretical calculations. Theoretical calculations also indicate that the higher discrete tones observed in the measurements are related to the screech phenomena. Limited experiments on the sensitivity of a free 2-D, C-D nozzle to externally imposed sound are also presented. It is shown that a 2-D, C-D nozzle with a cutback is less excitable than a 2-D C-D nozzle with no cutback. At a pressure ratio of 1.5 unsteady separation from the diverging walls of the nozzle is noticed. This separation switches from one wall to the opposite wall thus providing an unsteady deflection of the plume. It is shown that this phenomenon is related to the venting provided by the cutback section.

  18. NASA Glenn Research Center Acoustical Testing Laboratory: Five year retrospective

    Cooper, Beth A.; Akers, James C.; Passe, Paul J.

    2005-09-01

    In the five years since the NASA Glenn Research Center Acoustical Testing Laboratory (ATL) opened its doors in September, 2000, it has developed a comprehensive array of services and products that support hearing conservation goals within NASA and industry. The ATL provides acoustic emission testing and noise control engineering services for a variety of specialized customers, particularly developers of equipment and science experiments manifested for NASA's manned space missions. The ATL aggressively supports the vision of a low-noise on-orbit environment, which facilitates mission success as well as crew health, safety, and comfort. In concert with these goals, the ATL also produces and distributes free educational resources and low-noise advocacy tools for hearing conservation education and awareness. Among these are two compact discs of auditory demonstrations (of phenomena in acoustics, hearing conservation, and communication), and presentations, software packages, and other educational materials for use by engineers, audiologists, and other hearing conservation stakeholders. This presentation will highlight ATL's construction, history, technical capabilities, and current projects and will feature demonstrations of some of the unique educational resource materials that are distributed by the ATL.

  19. Quality Testing of Gaseous Helium Pressure Vessels by Acoustic Emission

    Barranco-Luque, M; Hervé, C; Margaroli, C; Sergo, V

    1998-01-01

    The resistance of pressure equipment is currently tested, before commissioning or at periodic maintenance, by means of normal pressure tests. Defects occurring inside materials during the execution of these tests or not seen by usual non-destructive techniques can remain as undetected potential sources of failure . The acoustic emission (AE) technique can detect and monitor the evolution of such failures. Industrial-size helium cryogenic systems employ cryogens often stored in gaseous form under pressure at ambient temperature. Standard initial and periodic pressure testing imposes operational constraints which other complementary testing methods, such as AE, could significantly alleviate. Recent reception testing of 250 m3 GHe storage vessels with a design pressure of 2.2 MPa for the LEP and LHC cryogenic systems has implemented AE with the above-mentioned aims.

  20. Vibration and Acoustic Test Facility (VATF): User Test Planning Guide

    Fantasia, Peter M.

    2011-01-01

    Test process, milestones and inputs are unknowns to first-time users of the VATF. The User Test Planning Guide aids in establishing expectations for both NASA and non-NASA facility customers. The potential audience for this guide includes both internal and commercial spaceflight hardware/software developers. It is intended to assist their test engineering personnel in test planning and execution. Material covered includes a roadmap of the test process, roles and responsibilities of facility and user, major milestones, facility capabilities, and inputs required by the facility. Samples of deliverables, test article interfaces, and inputs necessary to define test scope, cost, and schedule are included as an appendix to the guide.

  1. ATLAS TileCal Sub-Module Production at UIUC - Photos of Prototype PMT Test Setup

    Errede, Steve

    2001-01-01

    Photo 1 - Entrance to the lab. Photo 2 - A shot of the center of the lab. Photo 3 - The back of the lab. The Dark Box: Photo 4 - A view of the outside of the Dark Box along with its dry nitrogen system. Photo 5 - A view of the inside of the Dark Box. Photo 6 - The LED holder, beam splitter (removed in this shot), and a pulsing circuit. Photo 7 - The PMT holder. Photo 8 - A possible design for a Stepper Motor controlled filter wheel. Photo 9 - Polishing area for the optical fibers. R&D Work on Stepper Motor/Motion Control: Photo 10 - The complete prototype of the Stepper Motor setup. Photo 11 - The prototype of the Main Stepper Motor Driver Board. Photo 12 - The prototype of the Stepper Motor Power Amplifer. Photo 13 - The prototype of the Stepper Motor LabPC + Interface Board.

  2. An Evaluation of the Additional Acoustic Power Needed to Overcome the Effects of a Test-Articles Absorption During Reverberant Chamber Acoustic Testing of Spaceflight Hardware

    Hozman, Aron D.; Hughes, William O.

    2014-01-01

    It is important to realize that some test-articles may have significant sound absorption that may challenge the acoustic power capabilities of a test facility. Therefore, to mitigate this risk of not being able to meet the customers target spectrum, it is prudent to demonstrate early-on an increased acoustic power capability which compensates for this test-article absorption. This paper describes a concise method to reduce this risk when testing aerospace test-articles which have significant absorption. This method was successfully applied during the SpaceX Falcon 9 Payload Fairing acoustic test program at the NASA Glenn Research Center Plum Brook Stations RATF.

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

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

    2009-01-01

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

  4. Application of acoustic emission to the testing pressure tubing materials

    Acoustic emission is one of the promising techniques for the detection of embrittlement. The Zr-2.5 Nb alloy used as pressure tubing material shows slightly low stress intensity factor when it absorbs hydrogen. In this paper, the relationship between acoustic emission count N and stress intensity factor K in the tensile test of edge-notched specimens is described. The K value is proportional to the square root of crack opening displacement phi in the elastic region. The double-notched specimens were cut from pressure tubes, and the single-notched specimens were cut from extruded bars. The crack opening displacement was measured with a clip gauge recommended by ASTM STP 410 Appendix, and the acoustic emission was measured with a Nortec AEMS-4 system and PZT-5 type sensors. The sensors were bonded on the surfaces of the specimens with epoxy adhesive or rubber contact. A peak of the acoustic emission count rate was observed at the yield point of each specimen similarly to many other metals. The N values and the size of plastic zone showed the theoretical relationship following 4th power law, on the other hand, the size of plastic zone depended linearly on the K values in elastic region. The slope and the intersection point of the regression curves for the total N count vs the square root of phi corresponding to the elastic field of stress-strain curves showed almost same values for the specimens of same shape. The influence of the bonding methods was not observed. (Kako, I.)

  5. Potential of acoustic emissions from three point bending tests as rock failure precursors

    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.

  6. Ball screw inspection setup

    Janusz, Rzepka; Sambor, Slawomir; Pienkowski, Janusz; Bielenin, Marcin

    2003-05-01

    In the following paper we describe arrangements of laser interferometer for investigation of screws and for inspection of ball screws. We have constructed two of them, namely: the technological setup for investigations of screw in process of production and the ball screw inspection setup. The former one is used to measure the pitch of screws. The data gathered during measurement is used to calculate the parameters for grinding machine. The later setup is used for testing parameters of complete ball screws. The software supporting this setup makes calculation of parameters of tested ball screw and creation of reports possible. Additionally, the inspection setup is the one that the torque measuring arrangements have been integrated on. Both the arrangements and the software allow for measurements of all parameters during movement of nut in full travel length of the ball screw and make charts and reports.

  7. Quality control of graphite mold by acoustic emission testing

    The brittleness of the graphite used for producing uranium tubes by gravity casting is monitored by acoustic test. Ancillary units, around a central data processing unit, also have a data processing function (micro-informatics) enabling the three following essential functions to be met: (1) control of the movement of integrating waves to five degrees of freedom, (2) control of the monitoring appliance and (3) pre-processing acquisition and presentation of the data. Mention is made of the facilities being used and of the progress of some research work

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

    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. Setup a photomultiplier tube test bench for use at LHAASO-KM2A

    Wang, Xu; Tian, Ye; Li, Changyu; Sun, Yansheng; Feng, Cunfeng

    2015-01-01

    To fulfill the requirements of testing the photomultiplier tubes of the electromagnetic detector at the Large High Altitude Air Shower Observatory (LHAASO), a multi-functional PMT test bench with a two-dimensional scanning system is developed. With this 2D scanning system, 16 PMTs are scanned simultaneously to test their uniformity and cathode transit time difference, and we can also perform PMT tests of SPE spectrum, gain vs. high voltage, linear behavior and dark noise. The programmable hardware and intelligent software of the test bench make it convenient to use and provide reliable results. The test methods are described in detail and primary results are presented.

  10. Specification of a cyclist target and test setup for the evaluation of Cyclist-AEB systems

    Montfort, S. van; Camp, O.M.G.C. op den; Fritz, M.; Wimmer, T.

    2015-01-01

    From 2018, AEB systems dedicated to avoid or mitigate car-to-cyclist collisions will be included in the safety assessment by Euro NCAP [1] & [2]. To test such systems, appropriate equipment and a test procedure are being developed in the project CATS (Cyclist-AES Testing System). Accidentology was u

  11. Setup of a photomultiplier tube test bench for use at LHAASO-KM2A

    Wang, Xu; Zhang, Zhong-Quan; Tian, Ye; Du, Yan-Yan; Zhao, Xiao; Shen, Fu-Wang; Li, Chang-Yu; Sun, Yansheng; Feng, Cunfeng

    2015-01-01

    To fulfill the requirements for testing the photomultiplier tubes (PMTs) of the electromagnetic detec- tor at the Large High Altitude Air Shower Observatory (LHAASO), a multi-functional PMT test bench with a two dimensional scanning system has been developed. With this 2D scanning system, 16 PMTs can be scanned simultaneously for characteristics tests, including uniformity, cathode transit time difference, single photo-electron spectrum, gain vs. high voltage, linear behavior and dark noise. ...

  12. Towards nondestructive testing of pre-crash systems in a HIL setup

    Ploeg, J.; Hendriks, F.M.; Schouten, N.J.

    2008-01-01

    Recently, the developments in the field of ADA systems shifted from comfort oriented systems to safety oriented systems. Consequently, the complexity of testing those systems increased. This leads to a demand for reproducible, efficient and safe testing methods for ADA systems in general, and pre-cr

  13. Test setup for long term reliability investigation of Silicon Carbide MOSFETs

    Baker, Nick; Munk-Nielsen, Stig; Beczkowski, Szymon

    2013-01-01

    Silicon Carbide MOSFETs are now widely available and have frequently been demonstrated to offer numerous advantages over Silicon based devices. However, reliability issues remain a significant concern in their realisation in commercial power electronic systems. In this paper, a test bench is...... designed that enables an accelerated power cycling test to be performed on packaged Silicon Carbide MOSFETs (TO-247) under realistic operating conditions. An accelerated power cycling test is then performed, with on-state resistance selected as the observed parameter to detect degradation. On...

  14. Acoustic and Thermal Testing of an Integrated Multilayer Insulation and Broad Area Cooling Shield System

    Wood, Jessica J.; Foster, Lee W.

    2013-01-01

    A Multilayer Insulation (MLI) and Broad Area Cooling (BAC) shield thermal control system shows promise for long-duration storage of cryogenic propellant. The NASA Cryogenic Propellant Storage and Transfer (CPST) project is investigating the thermal and structural performance of this tank-applied integrated system. The MLI/BAC Shield Acoustic and Thermal Test was performed to evaluate the MLI/BAC shield's structural performance by subjecting it to worst-case launch acoustic loads. Identical thermal tests using Liquid Nitrogen (LN2) were performed before and after the acoustic test. The data from these tests was compared to determine if any degradation occurred in the thermal performance of the system as a result of exposure to the acoustic loads. The thermal test series consisted of two primary components: a passive boil-off test to evaluate the MLI performance and an active cooling test to evaluate the integrated MLI/BAC shield system with chilled vapor circulating through the BAC shield tubes. The acoustic test used loads closely matching the worst-case envelope of all launch vehicles currently under consideration for CPST. Acoustic test results yielded reasonable responses for the given load. The thermal test matrix was completed prior to the acoustic test and successfully repeated after the acoustic test. Data was compared and yielded near identical results, indicating that the MLI/BAC shield configuration tested in this series is an option for structurally implementing this thermal control system concept.

  15. A test beam set-up for the characterization of the Geiger-mode avalanche photodiode technology for particle tracking

    Vilella, A; Trenado, J; Vila, A; Casanova, R; Vos, M; Garrido, L; Dieguez, A

    2012-01-01

    It is well known that avalanche photodiodes operated in the Geiger mode above the breakdown voltage offer a virtually infinite gain and time accuracy in the picosecond range that can be used for single photon detection. However, their performance in particle detection still remains unexplored. In this contribution, we are going to expose different steps that we have taken in order to prove the efficiency of the Geiger mode avalanche photodiodes in the aforementioned field. In particular, we will present a setup for the characterization of these sensors in a test beam. The expected results of the test beam at DESY and CERN have been simulated with Geant4 and will also be exposed.

  16. An improved method/setup for extended testing after the Cigre, Method II

    Henriksen, Mogens; Holbøll, Joachim; Rygal, Roman

    The authors describe an improved version of the Cigre Method II test techinque used for testing the resistance of insulating materials to partial discharges (PDs). The method was extended to continuous PD measurements and pulse analyses. It was sound that parameters such as selective fuse...... discussed. The application of the system showed typical behavior of the discharges and lifetimes that was strongly dependent on the filler type...

  17. Design and building of a new experimental setup for testing hydrogen storage materials

    Andreasen, A.

    2005-01-01

    For hydrogen to become the future energy carrier a suitable way of storing hydrogen is needed, especially if hydrogen is to be used in mobile applications such as cars. To test potential hydrogen storage materials with respect to capacity, kinetics andthermodynamics the Materials Research...

  18. Influence of different test parameters on in vitro drug release from topical diclofenac formulations in a vertical diffusion cell setup.

    Klein, S

    2013-07-01

    In the past decades, the vertical diffusion cell has emerged as a useful device for testing drug release of topical dosage forms. However, to date neither a general USP method nor formulation-related monographs have been published in international pharmacopoeia. The purpose of the present work was to examine the influence of different test parameters in a vertical diffusion cell setup on in vitro drug release from semi-solid preparations for cutaneous application. Diclofenac was selected as the model compound. Release experiments were performed in a 7 ml Microett vertical diffusion cell system. Various test parameters, including the media composition and pH, degassing, membrane material and pore size, stirring speed and stirrer type, were varied. Results obtained with different test parameter settings clearly indicate that both drug properties and instrumental details can have a huge impact on the outcome of in vitro diffusion/drug release studies with the vertical diffusion cell. Thus, the selection of adequate test parameters is crucial for the success of the release experiments and, as shown in the present study, optimal test parameters/conditions need to be established and validated on a case by case study. PMID:23923638

  19. ESTIMATION OF PARAMETERS IN STEP-STRESS ACCELERATED LIFE TESTS FOR THE RAYLEIGH DISTRIBUTION UNDER CENSORING SETUP

    N. Chandra

    2014-12-01

    Full Text Available In this paper, step-stress accelerated life test strategy is considered in obtaining the failure time data of the highly reliable items or units or equipment in a specified period of time. It is assumed that life time data of such items follows a Rayleigh distribution with a scale parameter (θ which is the log linear function of the stress levels. The maximum likelihood estimates (MLEs of the scale parameters ( i θ at both the stress levels (s , i = 2,1 i are obtained under a cumulative exposure model. A simulation study is performed to assess the precision of the MLEs on the basis of mean square error (MSE and relative absolute bias (RABias. The coverage probabilities of approximate and bootstrap confidence intervals for the parameters involved under both the censoring setup are numerically examined. In addition to this, asymptotic variance and covariance matrix of the estimators are also presented.

  20. Infrared Thermography Assessment of Thermal Bridges in Building Envelope: Experimental Validation in a Test Room Setup

    Francesco Bianchi

    2014-10-01

    Full Text Available Thermal infrared imaging is a valuable tool to perform non-destructive qualitative tests and to investigate buildings envelope thermal-energy behavior. The assessment of envelope thermal insulation, ventilation, air leakages, and HVAC performance can be implemented through the analysis of each thermogram corresponding to an object surface temperature. Thermography also allows the identification of thermal bridges in buildings’ envelope that, together with windows and doors, constitute one of the weakest component increasing thermal losses. A quantitative methodology was proposed in previous researches by the authors in order to evaluate the effect of such weak point on the energy balance of the whole building. In the present work, in-field experimental measurements were carried out with the purpose of evaluating the energy losses through the envelope of a test room experimental field. In-situ thermal transmittance of walls, ceiling and roof were continuously monitored and each element was characterized by its own thermal insulation capability. Infrared thermography and the proposed quantitative methodology were applied to assess the energy losses due to thermal bridges. The main results show that the procedure confirms to be a reliable tool to quantify the incidence of thermal bridges in the envelope thermal losses.

  1. Integration of Acoustic Detection Equipment into ANTARES

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

    2005-01-01

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

  2. Acoustic Performance of Drive Rig Mufflers for Model Scale Engine Testing

    Stephens, David, B.

    2013-01-01

    Aircraft engine component testing at the NASA Glenn Research Center (GRC) includes acoustic testing of scale model fans and propellers in the 9- by15-Foot Low Speed Wind Tunnel (LSWT). This testing utilizes air driven turbines to deliver power to the article being studied. These air turbines exhaust directly downstream of the model in the wind tunnel test section and have been found to produce significant unwanted noise that reduces the quality of the acoustic measurements of the engine model being tested. This report describes an acoustic test of a muffler designed to mitigate the extraneous turbine noise. The muffler was found to provide acoustic attenuation of at least 8 dB between 700 Hz and 20 kHz which significantly improves the quality of acoustic measurements in the facility.

  3. Microelectronics Radiation Hardness: Test Set-up for the ALICE Pixel Detector

    Meddi, F; CERN. Geneva; Morando, M; Scarlassara, F; Segato, G F; Soramel, F; Vannucci, Luigi; Di Liberto, S

    2000-01-01

    Two different test apparatus were set up to check the radiation hardness of the pixel detector electronic components designed for the ALICE ITS. Motivations and the mainfeatures are described as well as results we reached. Preliminary results on the OMEGA3/LHC1 chip are also presented. List of figures: Figure 1 Expected irradiation dose in ten years for the first layer (r=3.9 cm) of the pixel detectors operating in ALICE Figure 2 a) Chip digital part current (at bias of +3.5V) and b) chip analogue part current (at bias of +1.5V) as function of the cumulated dose for gamma irradiation Figure 3 Pixel efficiency as a function of the strobe delay a) and the annealing elapsed time b) after gamma irradiation Figure 4 a) Chip digital part current (at bias of +3.5V) and b) chip analogue part current (at bias of +1.5V) as function of the cumulated dose for proton irradiation. Pixel efficiency, at different time intervals after proton irradiation, as a function of the strobe delay d) and the threshold scanning c)

  4. Ultrasonic testing device for pipes with an acoustic coupling liquid

    System for the ultrasonic testing of tubes comprising: a probe consisting of an ultrasonic transducer integral with a mirror receiving the ultrasonic wave emitted by the transducer and centred according to the axis of the probe, a mechanism to move the probe inside the tube under inspection, facilities for detecting ultrasonic echoes returned by the tube. It also features facilities for introducing an acoustic coupling liquid in the capacity included between the tube, the transducer and the mirror when the probe enters the tube being tested as well as for drawing off this liquid when the probe is withdrawn from the tube. These facilities mainly include a soft bag tank filled with the liquid and located at the lower part of the probe and communicating with the capacity to be filled with the liquid. This bag becomes flat when entering the tube after the probe and thus pushes part of the liquid it contains towards this capacity. This liquid assembles again by gravity in the bag when it leaves the tube being tested and returns to its usual shape

  5. Numerical simulation of the tip aerodynamics and acoustics test

    Tejero E, F.; Doerffer, P.; Szulc, O.; Cross, J. L.

    2016-04-01

    The application of an efficient flow control system on helicopter rotor blades may lead to improved aerodynamic performance. Recently, our invention of Rod Vortex Generators (RVGs) has been analyzed for helicopter rotor blades in hover with success. As a step forward, the study has been extended to forward flight conditions. For this reason, a validation of the numerical modelling for a reference helicopter rotor (without flow control) is needed. The article presents a study of the flow-field of the AH-1G helicopter rotor in low-, medium- and high-speed forward flight. The CFD code FLOWer from DLR has proven to be a suitable tool for the aerodynamic analysis of the two-bladed rotor without any artificial wake modelling. It solves the URANS equations with LEA (Linear Explicit Algebraic stress) k-ω model using the chimera overlapping grids technique. Validation of the numerical model uses comparison with the detailed flight test data gathered by Cross J. L. and Watts M. E. during the Tip Aerodynamics and Acoustics Test (TAAT) conducted at NASA in 1981. Satisfactory agreements for all speed regimes and a presence of significant flow separation in high-speed forward flight suggest a possible benefit from the future implementation of RVGs. The numerical results based on the URANS approach are presented not only for a popular, low-speed case commonly used in rotorcraft community for CFD codes validation but preferably for medium- and high-speed test conditions that have not been published to date.

  6. Acoustic and microwave tests in a cylindrical cavity for acoustic gas thermometry at high temperature.

    Zhang, K; Feng, X J; Gillis, K; Moldover, M; Zhang, J T; Lin, H; Qu, J F; Duan, Y N

    2016-03-28

    Relative primary acoustic gas thermometry (AGT) determines the ratios of thermodynamic temperatures from measured ratios of acoustic and microwave resonance frequencies in a gas-filled metal cavity on isotherms of interest. When measured in a cavity with known dimensions, the frequencies of acoustic resonances in a gas determine the speed of sound, which is a known function of the thermodynamic temperature T. Changes in the dimensions of the cavity are measured using the frequencies of the cavity's microwave resonances. We explored techniques and materials for AGT at high temperatures using a cylindrical cavity with remote acoustic transducers. We used gas-filled ducts as acoustic waveguides to transmit sound between the cavity at high temperatures and the acoustic transducers at room temperature. We measured non-degenerate acoustic modes in a cylindrical cavity in the range 295 Kacoustic frequencies increased from 2×10(-6) at 295 K to 5×10(-6) at 797 K. In addition, we measured the frequencies of several transverse magnetic (TM) microwave resonances up to 1000 K in order to track changes in the cavity's length L and radius R. The fractional standard deviation of the values of L deduced from three TM modes increased from 3×10(-6) for T<600 K to 57 × 10(-6) at 1000 K. We observed similar inconsistencies in a previous study. PMID:26903106

  7. Development of ultrasonic testing equipment incorporating electromagnetic acoustic transducer

    This paper describes an automatic flaw detection equipment and heat-resistant ultrasonic transducer for plate thickness measurement. The automatic flaw detection equipment is used during in-service inspection. It comprises an angle-beam electromagnetic acoustic transducer (EMAT), mounted on a vehicle, for scanning the pipe surface to be inspected. The EMAT functions without direct contact with the pipe surface through a coupling liquid, the vehicle does not require a guide track installed on the pipe surface, since it is equipped with magnetic wheels that adhere to the pipe, permitting it to travel along the circumferential weld joint of a carbon steel pipe. Another heat-resistant ultrasonic transducer is a normal beam EMAT and is used during plant operation. As a result, the automatic flaw detection equipment could detect a 1 mm deep notch cut on a test piece of 25 mm thick carbon steel plate. The vehicle location accuracy on the piping was ±2 mm. The normal beam EMAT could measure the plate thickness, within ±0.3 mm accuracy for the range of plate thickness 4 mm to 12 mm at 300degC. (author)

  8. Early diagnosis of acoustic neuroma by quantitative neurootological and neuroradiological tests

    Haid, C.T.

    1983-02-01

    Every patient with unilateral and sensoneural loss of hearing, independent of vertigo anamnesis or X-rays must be further examined by a vestibular test. Between 1974 and 1980, 80 acoustic neuromas could be diagnosed, including 12 early stage neuromas. This relatively high detection quote of small neuromas is due to a special diagnostical program: All 80 patients with acoustic neuroma had a pathological vestibular result. The positional test turned out to be the most sensitive examination in the early diagnosis of acoustic neuromas and yields a still higher incidence than the caloric test: 95% of the patients with a neurinoma showed a pathological result in the positional test. So every patient suffering from an unidentified unilateral and sensoneural hearing loss combined with a pathological result in the positional test must be further examined by a cisternomeatography or computerized tomography (using air-insufflation). Every fifth of these patients showed unique hints of an acoustic neuroma in the neuroradiological test.

  9. A Laboratory Test Setup for in Situ Measurements of the Dielectric Properties of Catalyst Powder Samples under Reaction Conditions by Microwave Cavity Perturbation: Set up and Initial Tests

    Markus Dietrich

    2014-09-01

    Full Text Available The catalytic behavior of zeolite catalysts for the ammonia-based selective catalytic reduction (SCR of nitrogen oxides (NOX depends strongly on the type of zeolite material. An essential precondition for SCR is a previous ammonia gas adsorption that occurs on acidic sites of the zeolite. In order to understand and develop SCR active materials, it is crucial to know the amount of sorbed ammonia under reaction conditions. To support classical temperature-programmed desorption (TPD experiments, a correlation of the dielectric properties with the catalytic properties and the ammonia sorption under reaction conditions appears promising. In this work, a laboratory test setup, which enables direct measurements of the dielectric properties of catalytic powder samples under a defined gas atmosphere and temperature by microwave cavity perturbation, has been developed. Based on previous investigations and computational simulations, a resonator cavity and a heating system were designed, installed and characterized. The resonator cavity is designed to operate in its TM010 mode at 1.2 GHz. The first measurement of the ammonia loading of an H-ZSM-5 zeolite confirmed the operating performance of the test setup at constant temperatures of up to 300 °C. It showed how both real and imaginary parts of the relative complex permittivity are strongly correlated with the mass of stored ammonia.

  10. Is reverberation time adequate for testing the acoustical quality of unroofed auditoriums?

    Paini, Dario; Gade, Anders Christian; Rindel, Jens Holger

    2006-01-01

    Especially during summertime, public squares, stadiums and other kinds of open spaces, are frequently used for live concerts (pop, jazz, classical, etc.) - both with and without amplification. Based on the first author’s PhD thesis, this paper aims at illustrating whether reverberation time (EDT, T......30) and other acoustical parameters normally used to test the acoustical quality of closed auditoria, such as concert halls, theatres, opera houses, are suitable and sufficient for testing the acoustical quality of open performance spaces. Simulations as well as measurements were carried out to study...... the acoustics of open squares surrounded by hard, vertical, reflecting building facades. Especially when concerts are amplified, echoes or flutter echoes are often found to be the most important characteristic – and problem! Therefore, emphasis was given to finding an acoustical parameter – or a set...

  11. Validation and Simulation of Ares I Scale Model Acoustic Test - 3 - Modeling and Evaluating the Effect of Rainbird Water Deluge Inclusion

    Strutzenberg, Louise L.; Putman, Gabriel C.

    2011-01-01

    The Ares I Scale Model Acoustics Test (ASMAT) is a series of live-fire tests of scaled rocket motors meant to simulate the conditions of the Ares I launch configuration. These tests have provided a well documented set of high fidelity measurements useful for validation including data taken over a range of test conditions and containing phenomena like Ignition Over-Pressure and water suppression of acoustics. Building on dry simulations of the ASMAT tests with the vehicle at 5 ft. elevation (100 ft. real vehicle elevation), wet simulations of the ASMAT test setup have been performed using the Loci/CHEM computational fluid dynamics software to explore the effect of rainbird water suppression inclusion on the launch platform deck. Two-phase water simulation has been performed using an energy and mass coupled lagrangian particle system module where liquid phase emissions are segregated into clouds of virtual particles and gas phase mass transfer is accomplished through simple Weber number controlled breakup and boiling models. Comparisons have been performed to the dry 5 ft. elevation cases, using configurations with and without launch mounts. These cases have been used to explore the interaction between rainbird spray patterns and launch mount geometry and evaluate the acoustic sound pressure level knockdown achieved through above-deck rainbird deluge inclusion. This comparison has been anchored with validation from live-fire test data which showed a reduction in rainbird effectiveness with the presence of a launch mount.

  12. A Correlated Study of the Response of a Satellite to Acoustic Radiation Using Statistical Energy Analysis and Acoustic Test Data

    Aerospace payloads, such as satellites, are subjected to vibroacoustic excitation during launch. Sandia's MTI satellite has recently been certified to this environment using a combination of base input random vibration and reverberant acoustic noise. The initial choices for the acoustic and random vibration test specifications were obtained from the launch vehicle Interface Control Document (ICD). In order to tailor the random vibration levels for the laboratory certification testing, it was necessary to determine whether vibration energy was flowing across the launch vehicle interface from the satellite to the launch vehicle or the other direction. For frequencies below 120 Hz this issue was addressed using response limiting techniques based on results from the Coupled Loads Analysis (CLA). However, since the CLA Finite Element Analysis FEA model was only correlated for frequencies below 120 Hz, Statistical Energy Analysis (SEA) was considered to be a better choice for predicting the direction of the energy flow for frequencies above 120 Hz. The existing SEA model of the launch vehicle had been developed using the VibroAcoustic Payload Environment Prediction System (VAPEPS) computer code[1]. Therefore, the satellite would have to be modeled using VAPEPS as well. As is the case for any computational model, the confidence in its predictive capability increases if one can correlate a sample prediction against experimental data. Fortunately, Sandia had the ideal data set for correlating an SEA model of the MTI satellite--the measured response of a realistic assembly to a reverberant acoustic test that was performed during MTI's qualification test series. The first part of this paper will briefly describe the VAPEPS modeling effort and present the results of the correlation study for the VAPEPS model. The second part of this paper will present the results from a study that used a commercial SEA software package[2] to study the effects of in-plane modes and to evaluate

  13. Use of Acoustic Emission During Scratch Testing for Understanding Adhesion Behavior of Aluminum Nitride Coatings

    Choudhary, R. K.; Mishra, P.

    2016-06-01

    In this work, acoustic emission during scratch testing of the aluminum nitride coatings formed on stainless steel substrate by reactive magnetron sputtering was analyzed to assess the coating failure. The AlN coatings were formed under the variation of substrate temperature, substrate bias potential, and discharge power. The coatings deposited in the temperature range of 100 to 400 °C showed peak acoustic emission less than 1.5%, indicating ductile nature of the coating. However, for coatings formed with substrate negative bias potential of 20 to 50 V, numerous sharp acoustic bursts with maximum emission approaching 80% were observed, indicating brittle nature of the coatings with large number of defects present. The shift in the intensity of the first major acoustic peak toward higher load, with the increasing bias potential, confirmed improved adhesion of the coating. Also, the higher discharge power resulted in increased acoustic emission.

  14. Use of Acoustic Emission During Scratch Testing for Understanding Adhesion Behavior of Aluminum Nitride Coatings

    Choudhary, R. K.; Mishra, P.

    2016-04-01

    In this work, acoustic emission during scratch testing of the aluminum nitride coatings formed on stainless steel substrate by reactive magnetron sputtering was analyzed to assess the coating failure. The AlN coatings were formed under the variation of substrate temperature, substrate bias potential, and discharge power. The coatings deposited in the temperature range of 100 to 400 °C showed peak acoustic emission less than 1.5%, indicating ductile nature of the coating. However, for coatings formed with substrate negative bias potential of 20 to 50 V, numerous sharp acoustic bursts with maximum emission approaching 80% were observed, indicating brittle nature of the coatings with large number of defects present. The shift in the intensity of the first major acoustic peak toward higher load, with the increasing bias potential, confirmed improved adhesion of the coating. Also, the higher discharge power resulted in increased acoustic emission.

  15. Maneuver Acoustic Flight Test of the Bell 430 Helicopter Data Report

    Watts, Michael E.; Greenwood, Eric; Smith, Charles D.; Snider, Royce; Conner, David A.

    2014-01-01

    A cooperative ight test by NASA, Bell Helicopter and the U.S. Army to characterize the steady state acoustics and measure the maneuver noise of a Bell Helicopter 430 aircraft was accomplished. The test occurred during June/July 2011 at Eglin Air Force Base, Florida. This test gathered a total of 410 test points over 10 test days and compiled an extensive database of dynamic maneuver measurements. Three microphone arrays with up to 31 microphon. es in each were used to acquire acoustic data. Aircraft data included Differential Global Positioning System, aircraft state and rotor state information. This paper provides an overview of the test and documents the data acquired.

  16. Majorana Thermosyphon Prototype Experimental Setup

    Reid, Douglas J.; Guzman, Anthony D.; Munley, John T.

    2011-08-01

    This report presents the experimental setup of Pacific Northwest National Laboratory’s MAJORANA DEMONSTRATOR thermosyphon prototype cooling system. A nitrogen thermosyphon prototype of such a system has been built and tested at PNNL. This document presents the experimental setup of the prototype that successfully demonstrated the heat transfer performance of the system.

  17. Langasite Surface Acoustic Wave Sensors: Fabrication and Testing

    Zheng, Peng; Greve, David W.; Oppenheim, Irving J.; Chin, Tao-Lun; Malone, Vanessa

    2012-02-01

    We report on the development of harsh-environment surface acoustic wave sensors for wired and wireless operation. Surface acoustic wave devices with an interdigitated transducer emitter and multiple reflectors were fabricated on langasite substrates. Both wired and wireless temperature sensing was demonstrated using radar-mode (pulse) detection. Temperature resolution of better than ±0.5°C was achieved between 200°C and 600°C. Oxygen sensing was achieved by depositing a layer of ZnO on the propagation path. Although the ZnO layer caused additional attenuation of the surface wave, oxygen sensing was accomplished at temperatures up to 700°C. The results indicate that langasite SAW devices are a potential solution for harsh-environment gas and temperature sensing.

  18. Testing of welded clad pipelines using acoustic emission method

    Recording of signals of acoustic emission (AE) on structure loading enables not only to determine the location of defects, but also to evaluate conditions, which occur in materials in defect neighbourhood, that is to approach to evaluation of a dauger degree of one or another defect. Results of AE recording and analysis on loading of pipelines sections with welded joints on 22 K steel were considered. The behaviour of preliminarily grown fatigue cracks and natural defects of welding origin was compared

  19. Intensity modification of acoustic emission signals under thermocyclic tests of high-temperature steel EP33

    With the help of the acoustic emission (AE) method a study is made into structural and phase transformations in a heat resistant austenitic steel Kh12N22T3MR under conditions of cyclic heating up to 600 deg C and constant tensile loading. Based on the analysis of acoustic emission data the temperature dependence of AE signal intensity on thermal cycling is built and regularities of its variation are established for every test cycle

  20. Flight Acoustic Testing and For the Rotorcraft Noise Data Acquisition Model (RNM)

    Burley, Casey L.; Smith, Charles D.; Conner, David A.

    2006-01-01

    Two acoustic flight tests have been conducted on a remote test range at Eglin Air Force Base in the panhandle of Florida. The first was the "Acoustics Week" flight test conducted in September 2003. The second was the NASA Heavy Lift Rotorcraft Acoustics Flight Test conducted in October-November 2005. Benchmark acoustic databases were obtained for a number of rotorcraft and limited fixed wing vehicles for a variety of flight conditions. The databases are important for validation of acoustic prediction programs such as the Rotorcraft Noise Model (RNM), as well as for the development of low noise flight procedures and for environmental impact assessments. An overview of RNM capabilities and a detailed description of the RNM/ART (Acoustic Repropagation Technique) process are presented. The RNM/ART process is demonstrated using measured acoustic data for the MD600N. The RNM predictions for a level flyover speed sweep show the highest SEL noise levels on the flight track centerline occurred at the slowest vehicle speeds. At these slower speeds, broadband noise content is elevated compared to noise levels obtained at the higher speeds. A descent angle sweep shows that, in general, ground noise levels increased with increasing descent rates. Vehicle orientation in addition to vehicle position was found to significantly affect the RNM/ART creation of source noise semi-spheres for vehicles with highly directional noise characteristics and only mildly affect those with weak acoustic directionality. Based on these findings, modifications are proposed for RNM/ART to more accurately define vehicle and rotor orientation.

  1. Flight Acoustic Testing and Data Acquisition For the Rotor Noise Model (RNM)

    Conner, David A.; Burley, Casey L.; Smith, Charles D.

    2006-01-01

    Two acoustic flight tests have been conducted on a remote test range at Eglin Air Force Base in the panhandle of Florida. The first was the Acoustics Week flight test conducted in September 2003. The second was the NASA Heavy Lift Rotorcraft Acoustics Flight Test conducted in October-November 2005. Benchmark acoustic databases were obtained for a number of rotorcraft and limited fixed wing vehicles for a variety of flight conditions. The databases are important for validation of acoustic prediction programs such as the Rotorcraft Noise Model (RNM), as well as for the development of low noise flight procedures and for environmental impact assessments. An overview of RNM capabilities and a detailed description of the RNM/ART (Acoustic Repropagation Technique) process are presented. The RNM/ART process is demonstrated using measured acoustic data for the MD600N. The RNM predictions for a level flyover speed sweep show the highest SEL noise levels on the flight track centerline occurred at the slowest vehicle speeds. At these slower speeds, broadband noise content is elevated compared to noise levels obtained at the higher speeds. A descent angle sweep shows that, in general, ground noise levels increased with increasing descent rates. Vehicle orientation in addition to vehicle position was found to significantly affect the RNM/ART creation of source noise semi-spheres for vehicles with highly directional noise characteristics and only mildly affect those with weak acoustic directionality. Based on these findings, modifications are proposed for RNM/ART to more accurately define vehicle and rotor orientation.

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

    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.

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

    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.

  4. Acoustic Method for Testing the Quality of Sterilized Male Tsetse Flies Glossina Pallidipes

    Tsetse flies are able to emit different acoustic signals. An acoustic method to test the quality of sterilized male tsetse flies was developed. Differences in the sound characteristics between males and females, between sterilized and unsterilized males, and between males sterilized in air and nitrogen, were determined. Also, the acoustic parameters (frequency, time, sound pressure level) of the sounds that are useful as criteria for quality control were determined. It was demonstrated that only the so-called 'feeding sounds' can be used as a quality criterion. Both sexes emitted feeding sounds while feeding on a host. These sounds were also used to find sexual partners, and had an effect on male copulation success. An acoustic sound analysis programme was developed; it automatically measured sound activity (only feeding sounds) under standard conditions (random sample, relative humidity, temperature, light intensity). (author)

  5. Acoustic emission testing on an F/A-18 E/F titanium bulkhead

    Martin, Christopher A.; Van Way, Craig B.; Lockyer, Allen J.; Kudva, Jayanth N.; Ziola, Steve M.

    1995-04-01

    An important opportunity recently transpired at Northrop Grumman Corporation to instrument an F/A - 18 E/F titanium bulkhead with broad band acoustic emission sensors during a scheduled structural fatigue test. The overall intention of this effort was to investigate the potential for detecting crack propagation using acoustic transmission signals for a large structural component. Key areas of experimentation and experience included (1) acoustic noise characterization, (2) separation of crack signals from extraneous noise, (3) source location accuracy, and (4) methods of acoustic transducer attachment. Fatigue cracking was observed and monitored by strategically placed acoustic emission sensors. The outcome of the testing indicated that accurate source location still remains enigmatic for non-specialist engineering personnel especially at this level of structural complexity. However, contrary to preconceived expectations, crack events could be readily separated from extraneous noise. A further dividend from the investigation materialized in the form of close correspondence between frequency domain waveforms of the bulkhead test specimen tested and earlier work with thick plates.

  6. Aerodynamic and Acoustic Flight Test Results for the Stratospheric Observatory for Infrared Astronomy

    Cumming, Stephen B.; Cliatt, Larry James; Frederick, Michael A.; Smith, Mark S.

    2013-01-01

    As part of the Stratospheric Observatory for Infrared Astronomy (SOFIA) program, a 747SP airplane was modified to carry a 2.5 meter telescope in the aft section of the fuselage. The resulting airborne observatory allows for observations above 99 percent of the water vapor in the atmosphere. The open cavity created by the modifications had the potential to significantly affect the airplane in the areas of aerodynamics and acoustics. Several series of flight tests were conducted to clear the airplanes operating envelope for astronomical observations, planned to be performed between the altitudes of 39,000 feet and 45,000 feet. The flight tests were successfully completed. Cavity acoustics were below design limits, and the overall acoustic characteristics of the cavity were better than expected. The modification did have some effects on the stability and control of the airplane, but these effects were not significant. Airplane air data systems were not affected by the modifications. This paper describes the methods used to examine the aerodynamics and acoustic data from the flight tests and provides a discussion of the flight test results in the areas of cavity acoustics, stability and control, and air data.

  7. Aerodynamic and Acoustic Flight Test Results and Results for the Stratospheric Observatory for Infrared Astronomy

    Cumming, Stephen B.; Smith, Mark S.; Cliatt, Larry J.; Frederick, Michael A.

    2014-01-01

    As part of the Stratospheric Observatory for Infrared Astronomy program, a 747SP airplane was modified to carry a 2.5-m telescope in the aft section of the fuselage. The resulting airborne observatory allows for observations above 99 percent of the water vapor in the atmosphere. The open cavity created by the modifications had the potential to significantly affect the airplane in the areas of aerodynamics and acoustics. Several series of flight tests were conducted to clear the operating envelope of the airplane for astronomical observations, planned to be performed between the altitudes of 35,000 ft and 45,000 ft. The flight tests were successfully completed. Cavity acoustics were below design limits, and the overall acoustic characteristics of the cavity were better than expected. The modification did have some effects on the stability and control of the airplane, but these effects were not significant. Airplane air data systems were not affected by the modifications. This paper describes the methods used to examine the aerodynamics and acoustic data from the flight tests and provides a discussion of the flight-test results in the areas of cavity acoustics, stability and control, and air data.

  8. Characterization of acoustic lenses with the Foucault test by confocal laser scanning microscopy

    Ahmed Mohamed, E. T.; Abdelrahman, A.; Pluta, M.; Grill, W.

    2010-03-01

    In this work, the Foucault knife-edge test, which has traditionally been known as the classic test for optical imaging devices, is used to characterize an acoustic lens for operation at 1.2 GHz. A confocal laser scanning microscope (CLSM) was used as the illumination and detection device utilizing its pinhole instead of the classical knife edge that is normally employed in the Foucault test. Information about the geometrical characteristics, such as the half opening angle of the acoustic lens, were determined as well as the quality of the calotte of the lens used for focusing. The smallest focal spot size that could be achieved with the examined lens employed as a spherical reflector was found to be about 1 μm. By comparison to the idealized resolution a degradation of about a factor of 2 can be deduced. This limits the actual quality of the acoustic focus.

  9. The experimental setup of the Interaction in Crystals for Emission of RADiation collaboration at Mainzer Mikrotron: Design, commissioning, and tests

    Lietti, D.; Backe, H.; Bagli, E.; Bandiera, L.; Berra, A.; Carturan, S.; De Salvador, D.; Germogli, G.; Guidi, V.; Lauth, W.; Mazzolari, A.; Prest, M.; Vallazza, E.

    2015-04-01

    Silicon/germanium flat/bent crystals are thin devices able to efficiently deflect charged particle GeV-energy beams up to a few hundreds of μrad; moreover, high intensity photons can be efficiently produced in the so-called Multi-Volume Reflection (MVR) and Multiple Volume Reflections in One Crystal (MVROC) conditions. In the last years, the research interest in this field has moved to the dynamic studies of light negative leptons in the low energy range: the possibility to deflect negative particles and to produce high intensity γ sources via the coherent interactions with crystals in the sub-GeV energy range has been proved by the ICE-RAD (Interaction in Crystals for Emission of RADiation) Collaboration at the MAinzer MIkrotron (MAMI, Germany). This paper describes the setup used by the ICE-RAD experiment for the crystals characterization (both in terms of deflection and radiation emission properties): a high precision goniometer is used to align the crystals with the incoming beam, while a silicon based profilometer and an inorganic scintillator reconstruct, respectively, the particle position and the photon spectra after the samples. The crystals manufacturing process and their characterization, the silicon profilometer commissioning at the CERN PS T9 beamline, and the commissioning of the whole setup installed at MAMI are presented.

  10. Design of crude oil storage tank for acoustic emission testing

    The integrity of crude oil storage tank needs to be well managed because they can contain a large inventory of hazardous material and because of the high cost such as cleaning and waste disposal prior to disposal and maintenance. Costs involved in cleaning and inspection can be up to several hundreds thousand Malaysian Ranting. If the floor then proves to be in good condition, these costs have been wasted. Acoustic Emission (AE) is proposed to be use for monitoring the floor of the storage tank on line without doing cleaning and waste disposal. A storage tank will be fabricated for storing the crude oil and then the corrosion process will be monitor using AE method. This paper will discuss the background, material and is technical specification, design and also the difficulties faced during design and fabrication process. (Author)

  11. Acoustic Noise Test Report for the SWIFT Wind Turbine in Boulder, CO

    Roadman, J.; Huskey, A.

    2013-04-01

    This report summarizes the results of an acoustic noise test that the National Renewable Energy Laboratory (NREL) conducted on the SWIFT wind turbine. This test was conducted in accordance with the International Electrotechnical Commission's (IEC) standard, Wind Turbine Generator Systems Part 11: Acoustic Noise Measurement Techniques, IEC 61400-11 Ed.2.1, 2006-11. However, because the SWIFT is a small turbine, as defined by IEC, NREL used 10-second averages instead of 60-second averages and utilized binning by wind speed instead of regression analysis.

  12. Acoustic Noise Test Report for the Viryd CS8 Wind Turbine

    Roadman, J.; Huskey, A.

    2013-07-01

    This report summarizes the results of an acoustic noise test that the National Renewable Energy Laboratory (NREL) conducted on the Viryd CS8 wind turbine. This test was conducted in accordance with the International Electrotechnical Commission's (IEC) standard, Wind Turbine Generator Systems Part 11: Acoustic Noise Measurement Techniques, IEC 61400-11 Ed.2.1, 2006-11. However, because the Viryd CS8 is a small turbine, as defined by IEC, NREL used 10-second averages instead of 60-second averages and binning by wind speed instead of regression analysis.

  13. Application of acoustic emission testing as a non-destructive quality control of conrete

    The time dependence of texture changes in concrete is studied in short-time pressure experiments, using the method of acoustic emission testing. These investigations have been performed as a function of strength and composition of the material under study. As a result, the method of acoustic emission testing is shown to be an adequate method to evaluate the evolution and the character of the structural changes. In the case where only the time developement is of interest, a simple electronic method, the pulse-sum-method or pulse rate method can be applied. However only a signal evaluation procedure can give information on the character of the structure changes. (orig./RW)

  14. Characterization of a Setup to test the Impact of High-Amplitude Pressure Waves on Living Cells

    Schmidt, Mischa; Kahlert, Ulf; Wessolleck, Johanna; Maciaczyk, Donata; Merkt, Benjamin; Maciaczyk, Jaroslaw; Osterholz, Jens; Nikkhah, Guido; Steinhauser, Martin O.

    2014-01-01

    The impact of pressure waves on cells may provide several possible applications in biology and medicine including the direct killing of tumors, drug delivery or gene transfection. In this study we characterize the physical properties of mechanical pressure waves generated by a nanosecond laser pulse in a setup with well-defined cell culture conditions. To systematically characterize the system on the relevant length and time scales (micrometers and nanoseconds) we use photon Doppler velocimetry (PDV) and obtain velocity profiles of the cell culture vessel at the passage of the pressure wave. These profiles serve as input for numerical pressure wave simulations that help to further quantify the pressure conditions on the cellular length scale. On the biological level we demonstrate killing of glioblastoma cells and quantify experimentally the pressure threshold for cell destruction.

  15. Flow and density testing ceramic nuclear fuel by an acoustic method

    Some problems of development and application of the acoustic method for nuclear fuel pellet quality assurance and testing the technology of their fabrication are considered. Dependences of frequences of intrinsic mechanical oscillations of pellets on their geometrical sizes are determined. A nomogram is developed for calculation of the specimen spectra of pellets. The method of hydrostatic weighing in mercury and the acoustic method are stated to have practically the same accuracy of density determination, while the accuracy of the method of hydrostatic weighing in water is more than three times less. It is shown that the acoustic method permits to exercise quality assurance fuel pellets by flaw and density testing, and at the corresponding arrangement of the control only the imaginary density at the relativistic error of 0.4%

  16. Recent experiments on acoustic leak detection

    In the ASB-sodium loop a series of injection experiments with water, helium, argon and nitrogen was performed. The aim of these tests was to get: a comparison of the acoustic signals, generated by water and gas injections with regard to intensity and frequency content; an experimental basis for the design of an acoustic calibration source. The experimental set-up, the variation parameters and first results will be discussed. The principal design of an acoustic calibration source and its range of application will be given. (author)

  17. Acoustic-Modal Testing of the Ares I Launch Abort System Attitude Control Motor Valve

    Davis, R. Benjamin; Fischbach, Sean R.

    2010-01-01

    The Attitude Control Motor (ACM) is being developed for use in the Launch Abort System (LAS) of NASA's Ares I launch vehicle. The ACM consists of a small solid rocket motor and eight actuated pintle valves that directionally allocate.thrust_- 1t.has-been- predicted-that significant unsteady. pressure.fluctuations.will.exist. inside the-valves during operation. The dominant frequencies of these oscillations correspond to the lowest several acoustic natural frequencies of the individual valves. An acoustic finite element model of the fluid volume inside the valve has been critical to the prediction of these frequencies and their associated mode shapes. This work describes an effort to experimentally validate the acoustic finite model of the valve with an acoustic modal test. The modal test involved instrumenting a flight-like valve with six microphones and then exciting the enclosed air with a loudspeaker. The loudspeaker was configured to deliver broadband noise at relatively high sound pressure levels. The aquired microphone signals were post-processed and compared to results generated from the acoustic finite element model. Initial comparisons between the test data and the model results revealed that additional model refinement was necessary. Specifically, the model was updated to implement a complex impedance boundary condition at the entrance to the valve supply tube. This boundary condition models the frequency-dependent impedance that an acoustic wave will encounter as it reaches the end of the supply tube. Upon invoking this boundary condition, significantly improved agreement between the test data and the model was realized.

  18. Statistical fracture of E-glass fibres using a bundle tensile test and acoustic emission monitoring

    R'Mili, M.; Moevus, M.; Godin, N.

    2009-01-01

    Statistical fracture of E-glass fibres using a bundle tensile test and acoustic emission monitoring correspondance: Corresponding author.Tel.: +33472436127; fax: +33472438528. (R?Mili, M.) (R?Mili, M.) Universite de Lyon--> , INSA-Lyon--> , MATEIS--> , 7 Avenue Jean Capelle--> , 69621 Villeurbanne Cedex--> - FRANCE (R?Mili, M.) Universite de Lyon--> , INSA-Lyo...

  19. Analysis of acoustic data from UK sodium/water reaction test facilities

    This paper describes acoustic measurements made during a number of sodium/water reaction experiments in the UK. The tests have included water and steam injections through both realistic (fatigue crack) defects and machined orifices and have covered a range of experimental conditions including those appropriate to the inlet and outlet regions of the EFR steam generators. Injection rates were typically in the range 0.1 to 30 g/s. Where possible, gas injections were also included in the test programme for comparison, since it is anticipated that a practical SGU acoustic leak detection system would include a facility for gas injections to allow system calibration, and to confirm transmission properties within the SGU. The test sections were instrumented with accelerometers on waveguides and in some cases included an under-sodium microphone situated about 300mm above the reaction zone. Tape recordings were made during the tests and used for detailed analysis off-line, although an audible output from one of the acoustic channels was used to monitor the progress of the injections and provide information for the rig operators. A comparison of the signal amplitudes measured during the experiments with typical reactor background noise was made and an estimate of the detection sensitivity of an acoustic monitoring system was deduced. 3 refs, 5 figs, 1 tab

  20. Testing Time and Frequency Fiber-Optic Link Transfer by Hardware Emulation of Acoustic-Band Optical Noise

    Lipiński Marcin

    2016-06-01

    Full Text Available The low-frequency optical-signal phase noise induced by mechanical vibration of the base occurs in field-deployed fibers. Typical telecommunication data transfer is insensitive to this type of noise but the phenomenon may influence links dedicated to precise Time and Frequency (T&F fiber-optic transfer that exploit the idea of stabilization of phase or propagation delay of the link. To measure effectiveness of suppression of acoustic noise in such a link, a dedicated measurement setup is necessary. The setup should enable to introduce a low-frequency phase corruption to the optical signal in a controllable way. In the paper, a concept of a setup in which the mechanically induced acoustic-band optical signal phase corruption is described and its own features and measured parameters are presented. Next, the experimental measurement results of the T&F transfer TFTS-2 system’s immunity as a function of the fibre-optic length vs. the acoustic-band noise are presented. Then, the dependency of the system immunity on the location of a noise source along the link is also pointed out.

  1. Baryon Acoustic Oscillation Intensity Mapping as a Test of Dark Energy

    Chang, Tzu-Ching; Pen, Ue-Li; Peterson, Jeffrey B.; McDonald, Patrick

    2007-01-01

    The expansion of the universe appears to be accelerating, and the mysterious anti-gravity agent of this acceleration has been called ``dark energy''. To measure the dynamics of dark energy, Baryon Acoustic Oscillations (BAO) can be used. Previous discussions of the BAO dark energy test have focused on direct measurements of redshifts of as many as $10^9$ individual galaxies, by observing the 21cm line or by detecting optical emission. Here we show how the study of acoustic oscillation in the ...

  2. Characteristics of acoustic wave from atmospheric nuclear explosions conducted at the USSR Test Sites

    Sokolova, Inna

    2015-04-01

    Availability of the acoustic wave on the record of microbarograph is one of discriminate signs of atmospheric (surface layer of atmosphere) and contact explosions. Nowadays there is large number of air wave records from chemical explosions recorded by the IMS infrasound stations installed during recent decade. But there is small number of air wave records from nuclear explosions as air and contact nuclear explosions had been conducted since 1945 to 1962, before the Limited Test Ban Treaty was signed in 1963 (the treaty banning nuclear weapon tests in the atmosphere, in outer space and under water) by the Great Britain, USSR and USA. That time there was small number of installed microbarographs. First infrasound stations in the USSR appeared in 1954, and by the moment of the USSR collapse the network consisted of 25 infrasound stations, 3 of which were located on Kazakhstan territory - in Kurchatov (East Kazakhstan), in Borovoye Observatory (North Kazakhstan) and Talgar Observatory (Northern Tien Shan). The microbarograph of Talgar Observatory was installed in 1962 and recorded large number of air nuclear explosions conducted at Semipalatinsk Test Site and Novaya Zemlya Test Site. The epicentral distance to the STS was ~700 km, and to Novaya Zemlya Test Site ~3500 km. The historical analog records of the microbarograph were analyzed on the availability of the acoustic wave. The selected records were digitized, the database of acoustic signals from nuclear explosions was created. In addition, acoustic signals from atmospheric nuclear explosions conducted at the USSR Test Sites were recorded by analogue broadband seismic stations at wide range of epicentral distances, 300-3600 km. These signals coincide well by its form and spectral content with records of microbarographs and can be used for monitoring tasks and discrimination in places where infrasound observations are absent. Nuclear explosions which records contained acoustic wave were from 0.03 to 30 kt yield for

  3. Irregular Liesegang-type patterns in gas phase revisited. I. Experimental setup, data processing, and test of the spacing law

    Torres-Guzmán, José C.; Buhse, Thomas; de la Calleja, Elsa María; González-Espinoza, Alfredo; Martínez-Mekler, Gustavo; Montoya-Nava, Fernando; Ramírez-Álvarez, Elizeth; Rivera-Islas, Marco; Rodríguez-Álvarez, Aurora; Müller, Markus F.

    2016-05-01

    Since the early work on Liesegang rings in gels, they have been a reference point for the study of pattern formation in chemical physics. Here we present a variant of the Liesegang experiment in gas phase, where ammonia and hydrochloric acid react within a glass tube producing a precipitate, which deposits along the tube wall producing a spatial pattern. With this apparently simple experiment a wide range of rich phenomenon can be observed due to the presence of convective flows and irregular dynamics reminiscent of turbulent behavior, for which precise measurements are scarce. In this first part of our work, we describe in detail the experimental setup, the method of data acquisition, the image processing, and the procedure used to obtain an intensity profile, which is representative of the amount of precipitate deposited at the tube walls. Special attention is devoted to the techniques rendering a data series reliable for statistical studies and model building, which may contribute to a characterization and understanding of the pattern formation phenomenon under consideration. As a first step in this direction, based on our data, we are able to show that the observed band pattern follows, with slight deviations, the spacing law encountered in common Liesegang rings, despite that the experimental conditions are very different. A further statistical correlation analysis of the data constitutes Paper II of this research.

  4. Acoustic measurements of the boiling stability tests on THORS sodium loop

    Acoustic data of boiling stability tests on the THORS (Thermal-Hydraulic Out-of-Reactor Safety) facility were obtained using three sodium-immersible high temperature microphones. The data was analyzed in both the time and frequency domains and provides the following information: (1) the acoustic signal due to sodium boiling was clearly observed; (2) the signal level and the repetition rate of boiling pulses are directly proportional to the applied heat flux; (3) a typical boiling pulse consists of a high frequency signal due mainly to the bubble collapses and a low frequency void oscillation; (4) the frequency spectra of the boiling and background pulses can be mostly assigned to various acoustic resonance frequencies of the THORS loop

  5. Electroacoustical simulation of listening room acoustics for project ARCHIMEDES

    Bech, Søren

    1989-01-01

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

  6. Virtual Acoustic Testing of Spacecraft Over a Broad Frequency Range Using FEM, BEM and Sea

    Vansant, K.; Borello, G.; De Langhe, K.; Courjal, A.

    2012-07-01

    During launch, a spacecraft is exposed to high levels of structural and acoustical loading. Acceptance tests are carried out before actual launch mimicking these loading conditions to validate that vibration, force and stress levels, which could damage the payload and lead to mission failure, remain below the design envelopes. The acceptance tests themselves, carried out on the actual payload, imply a risk of overtesting. Simulation models make it possible to carry out these tests in the virtual world. They can be used to derive specifications for the desired shaker, loudspeaker or horn excitation signals and to upfront quantify the risk of overtesting. Simulation also allows to uncover and rectify flaws or sensitivities in the spacecraft design rather quickly and at a low cost. This paper will discuss several simulation models (FEM, BEM and SEA) which can be used to mimic an acoustic acceptance test for different frequency ranges of interest.

  7. Reliable experimental setup to test the pressure modulation of Baerveldt Implant tubes for reducing post-operative hypotony

    Ramani, Ajay

    Glaucoma encompasses a group of conditions that result in damage to the optic nerve and can cause loss of vision and blindness. The nerve is damaged due to an increase in the eye's internal (intraocular) pressure (IOP) above the nominal range of 15 -- 20 mm Hg. There are many treatments available for this group of diseases depending on the complexity and stage of nerve degradation. In extreme cases where drugs or laser surgery do not create better conditions for the patient, ophthalmologists use glaucoma drainage devices to help alleviate the IOP. Many drainage implants have been developed over the years and are in use; but two popular implants are the Baerveldt Glaucoma Implant and the Ahmed Glaucoma Valve Implant. Baerveldt Implants are non-valved and provide low initial resistance to outflow of fluid, resulting in post-operative complications such as hypotony, where the IOP drops below 5 mm of Hg. Ahmed Glaucoma Valve Implants are valved implants which initially restrict the amount of fluid flowing out of the eye. The long term success rates of Baerveldt Implants surpass those of Ahmed Valve Implants because of post-surgical issues; but Baerveldt Implants' initial effectiveness is poor without proper flow restriction. This drives the need to develop new ways to improve the initial effectiveness of Baerveldt Implants. A possible solution proposed by our research team is to place an insert in the Baerveldt Implant tube of inner diameter 305 microns. The insert must be designed to provide flow resistance for the early time frame [e.g., first 30 -- 60 post-operative days] until sufficient scar tissue has formed on the implant. After that initial stage with the insert, the scar tissue will provide the necessary flow resistance to maintain the IOP above 5 mm Hg. The main objective of this project was to develop and validate an experimental apparatus to measure pressure drop across a Baerveldt Implant tube, with and without inserts. This setup will be used in the

  8. Model Test Setup and Program for Experimental Estimation of Surface Loads of the SSG Kvitsøy Pilot Plant from Extreme Wave Conditions

    Kofoed, Jens Peter; Larsen, Brian Juul

    This report presents the preparations done prior to model tests planned for November 2005 focusing on experimental estimation of the surface loads on the wave energy convert (WEC) Seawave Slot-Cone Generator (SSG) due to extreme wave conditions. SSG is a WEC utilizing wave overtopping in multiple...... planned pilot plant site is also modeled. The tests will be carried out at Dept. of Civil Engineering, Aalborg University (AAU) in the 3D deep water wave tank....... reservoirs. In the present SSG setup three reservoirs have been used. Model tests are planned using a model (length scale 1:60) of the SSG prototype at the planned location of a pilot plant at the west coast of the island Kvitsøy near Stavanger, Norway. The properties of the coastal area surrounding the...

  9. Application of acoustic emission analysis as a non-destructive test method for production control

    The application of acoustic emission measurements with a bandpass of 50 kHz - 1,5 MHz for the detection of fatigue-crack propagation in pressure vessels and to the perception of welding cracks is investigated. The method can also be used in laboratory tests for the determination of structural transformations of metals, for examinations in connection with stress-corrosion cracking and for tests of laminated materials. Some possibilities of application and the limits of the methode are shown. (orig.)

  10. Development of a wind energy converter and investigation of its operational function. Part 4: Test setup and results of measurement

    Armbrust, S.; Molly, J. P.

    1982-12-01

    Measurements made during test operations at the MODA.10 plant as well as at a 25 years old 6 kW wind energy converter are presented. The test arrangements, measurement results of both wind energy converters, and the experience gained are described.

  11. Free jet feasibility study of a thermal acoustic shield concept for AST/VCE application-dual flow. Comprehensive data report. Volume 1: Test nozzles and acoustic data

    Janardan, B. A.; Brausch, J. F.; Price, A. O.

    1984-01-01

    Acoustic and diagnostic data that were obtained to determine the influence of selected geometric and aerodynamic flow variables of coannular nozzles with thermal acoustic shields are summarized in this comprehensive data report. A total of 136 static and simulated flight acoustic test points were conducted with 9 scale-model nozzles The tested nozzles included baseline (unshielded), 180 deg shielded, and 360 deg shielded dual flow coannular plug configurations. The baseline configurations include a high radius ratio unsuppressed coannular plug nozzle and a coanuular plug nozzle and a coannular plug nozzle with a 20-chute outer stream suppressor. The tests were conducted at nozzle temperatures and pressure typical of operating conditions of variable cycle engine.

  12. Finalizing the CCSDS Space-Data Link Layer Security Protocol: Setup and Execution of the Interoperability Testing

    Fischer, Daniel; Aguilar-Sanchez, Ignacio; Saba, Bruno; Moury, Gilles; Biggerstaff, Craig; Bailey, Brandon; Weiss, Howard; Pilgram, Martin; Richter, Dorothea

    2015-01-01

    The protection of data transmitted over the space-link is an issue of growing importance also for civilian space missions. Through the Consultative Committee for Space Data Systems (CCSDS), space agencies have reacted to this need by specifying the Space Data-Link Layer Security (SDLS) protocol which provides confidentiality and integrity services for the CCSDS Telemetry (TM), Telecommand (TC) and Advanced Orbiting Services (AOS) space data-link protocols. This paper describes the approach of the CCSDS SDLS working group to specify and execute the necessary interoperability tests. It first details the individual SDLS implementations that have been produced by ESA, NASA, and CNES and then the overall architecture that allows the interoperability tests between them. The paper reports on the results of the interoperability tests and identifies relevant aspects for the evolution of the test environment.

  13. Measurements of the acoustic field on austenitic welds: a way to higher reliability in ultrasonic tests

    In nuclear power plants many of the welds in austenitic tubes have to be inspected by means of ultrasonic techniques. If component-identical test pieces are available, they are used to qualify the ultrasonic test technology. Acoustic field measurements on such test blocks give information whether the beam of the ultrasonic transducer reaches all critical parts of the weld region and which transducer type is best suited. Acoustic fields have been measured at a bimetallic, a V-shaped and a narrow gap weld in test pieces of wall thickness 33, 25 and 17 mm, respectively. Compression wave transducers 45, 60 and 70 and 45 shear wave transducers have been included in the investigation. The results are presented: (1) as acoustic C-scans for one definite probe position, (2) as series of C-scans for the probe moving on a track perpendicular to the weld, (3) as scan along the weld and (4) as effective beam profile. The influence of the scanning electrodynamic probe is also discussed. (orig.)

  14. The Evaluation of a Test Device for Human Occupant Restraint (THOR) Under Vertical Loading Conditions: Part 1 - Experimental Setup and Results

    Littell, Justin D.; Annett, Martin S.

    2013-01-01

    A series of 16 vertical tests were conducted on a Test Device for Human Occupant Restraint (THOR) - NT 50th percentile Anthropomorphic Test Device (ATD) at NASA Langley Research Center (LaRC). The purpose of the tests conducted at NASA LaRC was threefold. The first was to add vertical response data to the growing test database for THOR-NT development and validation. Second, the THOR-NT analytical computational models currently in development must be validated for the vertical loading environment. The computational models have been calibrated for frontal crash environments with concentration on accurately replicating head/neck, thoracic, and lower extremity responses. Finally, familiarity with the THOR ATD is necessary because NASA is interested in evaluating advanced ATDs for use in future flight and research projects. The THOR was subjected to vertical loading conditions ranging between 5 and 16 g in magnitude and 40 to 120 milliseconds (msec) in duration. It was also tested under conditions identical to previous tests conducted on the Hybrid II and III ATDs to allow comparisons to be made. Variations in the test setup were also introduced, such as the addition of a footrest in an attempt to offload some of the impact load into the legs. A full data set of the THOR-NT ATD will be presented and discussed. Results from the tests show that the THOR was largely insensitive to differences in the loading conditions, perhaps due in part to their small magnitudes. THOR responses, when compared to the Hybrid II and III in the lumbar region, demonstrated that the THOR more closely resembled the straight spine Hybrid setup. In the neck region, the THOR behaved more like the Hybrid III. However in both cases, the responses were not identical, indicating that the THOR would show differences in response than the Hybrid II and III ATDs when subjected to identical impact conditions. The addition of a footrest did not significantly affect the THOR response due to the nature of how

  15. Set-up of a pre-test mock-up experiment in preparation for the HCPB Breeder Unit mock-up experimental campaign

    Highlights: ► As preparation for the HCPB-TBM Breeder Unit out-of-pile testing campaign, a pre-test experiment (PREMUX) has been prepared and described. ► A new heater system based on a wire heater matrix has been developed for imitating the neutronic volumetric heating and it is compared with the conventional plate heaters. ► The test section is described and preliminary thermal results with the available models are presented and are to be benchmarked with PREMUX. ► The PREMUX integration in the air cooling loop L-STAR/LL in the Karlsruhe Institute for Technology is shown and future steps are discussed. -- Abstract: The complexity of the experimental set-up for testing a full-scaled Breeder Unit (BU) mock-up for the European Helium Cooled Pebble Bed Test Blanket Module (HCPB-TBM) has motivated to build a pre-test mock-up experiment (PREMUX) consisting of a slice of the BU in the Li4SiO4 region. This pre-test aims at verifying the feasibility of the methods to be used for the subsequent testing of the full-scaled BU mock-up. Key parameters needed for the modeling of the breeder material is also to be determined by the Hot Wire Method (HWM). The modeling tools for the thermo-mechanics of the pebble beds and for the mock-up structure are to be calibrated and validated as well. This paper presents the setting-up of PREMUX in the L-STAR/LL facility at the Karlsruhe Institute of Technology. A key requirement of the experiments is to mimic the neutronic volumetric heating. A new heater concept is discussed and compared to several conventional heater configurations with respect to the estimated temperature distribution in the pebble beds. The design and integration of the thermocouple system in the heater matrix and pebble beds is also described, as well as other key aspects of the mock-up (dimensions, layout, cooling system, purge gas line, boundary conditions and integration in the test facility). The adequacy of these methods for the full-scaled BU mock-up is

  16. Hydrophone spatial directivity and the induced difference in HIFU acoustic field test

    Chen, T; Zhang, D [Institute of Acoustics, Nanjing University, Nanjing 210093 (China); Hu, J M; Huang, W; Zhang, W, E-mail: Chent_qxs@jsfda.gov.cn [Jiangsu Province Institute for Medical Equipment Testing, Nanjing 210012 (China)

    2011-02-01

    Hydrophone has been widely used in testing ultrasonic field distribution. But the hydrophone has a certain directivity, which may bring error in the actual acoustic field measurements. So it is necessary to meet some requirements about the directivity of hydrophone. In the measurement, the spatial directivities of needle hydrophone, membrane hydrophone and robust hydrophone is measured and a comparison about measured data of HIFU acoustic field with them is given. Experimental results indicate that the asymmetric special directivity of hydrophone is due to manufacturing processes and other reasons. As a result, it is not sufficient to test the directivity of hydrophone along one axis. It is necessary to adjust the direction of the hydrophone when characterizing the HIFU field.

  17. Hydrophone spatial directivity and the induced difference in HIFU acoustic field test

    Hydrophone has been widely used in testing ultrasonic field distribution. But the hydrophone has a certain directivity, which may bring error in the actual acoustic field measurements. So it is necessary to meet some requirements about the directivity of hydrophone. In the measurement, the spatial directivities of needle hydrophone, membrane hydrophone and robust hydrophone is measured and a comparison about measured data of HIFU acoustic field with them is given. Experimental results indicate that the asymmetric special directivity of hydrophone is due to manufacturing processes and other reasons. As a result, it is not sufficient to test the directivity of hydrophone along one axis. It is necessary to adjust the direction of the hydrophone when characterizing the HIFU field.

  18. The Alcock Paczy\\'nski test with Baryon Acoustic Oscillations: systematic effects for future surveys

    Lepori, Francesca; Di Dio, Enea; Viel, Matteo; Baccigalupi, Carlo; Durrer, Ruth

    2016-01-01

    We investigate the Alcock Paczy\\'nski (AP) test applied to the Baryon Acoustic Oscillation (BAO) feature in the galaxy correlation function. By using a general formalism that includes relativistic effects, we quantify the importance of the linear redshift space distortions and gravitational lensing corrections to the galaxy number density fluctuation. We show that redshift space distortions significantly affect the shape of the correlation function, both in radial and transverse directions, c...

  19. Points in the set-up of tests for fMRI. Toward the delineation of language-competent areas in clinical practice

    This hospital has performed fMRI of language-competent areas of the brain to identify the language-dominant hemisphere and obtain the configuration of the focus in the language-dominant side of the brain. Until now, signals have been detected in only two of fifteen patients who were diagnosed by language tests of a last-syllable word chain. In the present experiment, we tried to have subjects select the type of test. The result was that changes in signals were detected in eight of ten patients. Although the set-up of tests for fMRI is said to hold significant value, clear-cut studies to back this up have rarely been seen. Because clinical medicine treats patients who have difficulty in communication or suffer from aphasia, it is important to take into consideration individual variations and to set up a test suitable for, or achievable by, these individuals. The present method enabled us to avoid failure in examination caused by unsuccessful tests. (author)

  20. KLauS: an ASIC for silicon photomultiplier readout and its application in a setup for production testing of scintillating tiles

    Briggl, K; Hagdorn, R; Harion, T; Schultz-Coulon, H.C; Shen, W

    2014-01-01

    signals from silicon photomultipliers. Developed as an analog front-end for future calorimeters with high granularity as pursued by the AHCAL concept in the CALICE collaboration, the ASIC is designed to measure the charge signal of the sensors in a large dynamic range and with low electronic noise contributions. In order to tune the operation voltage of each sensor individually, an 8-bit DAC to tune the voltage at the input terminal within a range of 2V is implemented. Using an integrated fast comparator with low jitter, the time information can be measured with subnanosecond resolution. The low power consumption of the ASIC can be further decreased using power gating techniques. Future versions of KLauS are under development and will incorporate an ADC with a resolution of up to 12-bits and blocks for digital data transmission. The chip is used in a setup for mass testing and characterization of scintillator tiles for the AHCAL ...

  1. Structural Dynamic Assessment of the GN2 Piping System for NASA's New and Powerful Reverberant Acoustic Test Facility

    McNelis, Mark E.; Staab, Lucas D.; Akers, James C.; Hughes, WIlliam O.; Chang, Li, C.; Hozman, Aron D.; Henry, Michael W.

    2012-01-01

    The National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) has led the design and build of the new world-class vibroacoustic test capabilities at the NASA GRC's Plum Brook Station in Sandusky, Ohio, USA from 2007-2011. SAIC-Benham has completed construction of a new reverberant acoustic test facility to support the future testing needs of NASA's space exploration program and commercial customers. The large Reverberant Acoustic Test Facility (RATF) is approximately 101,000 cu ft in volume and was designed to operate at a maximum empty chamber acoustic overall sound pressure level (OASPL) of 163 dB. This combination of size and acoustic power is unprecedented amongst the world's known active reverberant acoustic test facilities. Initial checkout acoustic testing was performed on March 2011 by SAIC-Benham at test levels up to 161 dB OASPL. During testing, several branches of the gaseous nitrogen (GN2) piping system, which supply the fluid to the noise generating acoustic modulators, failed at their "t-junctions" connecting the 12 inch supply line to their respective 4 inch branch lines. The problem was initially detected when the oxygen sensors in the horn room indicated a lower than expected oxygen level from which was inferred GN2 leaks in the piping system. In subsequent follow up inspections, cracks were identified in the failed "t-junction" connections through non-destructive evaluation testing . Through structural dynamic modeling of the piping system, the root cause of the "t-junction" connection failures was determined. The structural dynamic assessment identified several possible corrective design improvements to the horn room piping system. The effectiveness of the chosen design repairs were subsequently evaluated in September 2011 during acoustic verification testing to 161 dB OASPL.

  2. Combined UHV/high-pressure catalysis setup for depth-resolved near-surface spectroscopic characterization and catalytic testing of model catalysts

    Mayr, Lukas; Rameshan, Raffael; Klötzer, Bernhard; Penner, Simon; Rameshan, Christoph

    2014-05-01

    An ultra-high vacuum (UHV) setup for "real" and "inverse" model catalyst preparation, depth-resolved near-surface spectroscopic characterization, and quantification of catalytic activity and selectivity under technologically relevant conditions is described. Due to the all-quartz reactor attached directly to the UHV-chamber, transfer of the catalyst for in situ testing without intermediate contact to the ambient is possible. The design of the UHV-compatible re-circulating batch reactor setup allows the study of reaction kinetics under close to technically relevant catalytic conditions up to 1273 K without contact to metallic surfaces except those of the catalyst itself. With the attached differentially pumped exchangeable evaporators and the quartz-microbalance thickness monitoring equipment, a reproducible, versatile, and standardised sample preparation is possible. For three-dimensional near-surface sample characterization, the system is equipped with a hemispherical analyser for X-ray photoelectron spectroscopy (XPS), electron-beam or X-ray-excited Auger-electron spectroscopy, and low-energy ion scattering measurements. Due the dedicated geometry of the X-ray gun (54.7°, "magic angle") and the rotatable sample holder, depth analysis by angle-resolved XPS measurements can be performed. Thus, by the combination of characterisation methods with different information depths, a detailed three-dimensional picture of the electronic and geometric structure of the model catalyst can be obtained. To demonstrate the capability of the described system, comparative results for depth-resolved sample characterization and catalytic testing in methanol steam reforming on PdGa and PdZn near-surface intermetallic phases are shown.

  3. A novel facility for reduced-gravity testing: A setup for studying low-velocity collisions into granular surfaces.

    Sunday, C; Murdoch, N; Cherrier, O; Morales Serrano, S; Valeria Nardi, C; Janin, T; Avila Martinez, I; Gourinat, Y; Mimoun, D

    2016-08-01

    This work presents an experimental design for studying low-velocity collisions into granular surfaces in low-gravity. In the experiment apparatus, reduced-gravity is simulated by releasing a free-falling projectile into a surface container with a downward acceleration less than that of Earth's gravity. The acceleration of the surface is controlled through the use of an Atwood machine, or a system of pulleys and counterweights. The starting height of the surface container and the initial separation distance between the projectile and surface are variable and chosen to accommodate collision velocities up to 20 cm/s and effective accelerations of ∼0.1 to 1.0 m/s(2). Accelerometers, placed on the surface container and inside the projectile, provide acceleration data, while high-speed cameras capture the collision and act as secondary data sources. The experiment is built into an existing 5.5 m drop tower frame and requires the custom design of all components, including the projectile, surface sample container, release mechanism, and deceleration system. Data from calibration tests verify the efficiency of the experiment's deceleration system and provide a quantitative understanding of the performance of the Atwood system. PMID:27587140

  4. Acoustic emission measurement in a 20MJ superconducting magnet system of the cluster test coil

    This paper describes acoustic emission (AE) results which were measured during the second major experiment on the Cluster Test Coil at JAERI. This is the largest superconducting magnet system to date on which acoustic emission measurement has been carried out. The amplitudes and the counting rates of AE are shown as functions of coil operating current on three full current excursions. The amplitude results show the on-going process of emission and reduction during successive runs. A strong tendency of the AE counting rate to increase was observed at high currents after successive runs. The phenomenon of amplitude reduction and counting rate increase is attributed to an energy release change from larger single events to numerous smaller events. (author)

  5. Force Limiting Vibration Tests Evaluated from both Ground Acoustic Tests and FEM Simulations of a Flight Like Vehicle System Assembly

    Smith, Andrew; LaVerde, Bruce; Waldon, James; Hunt, Ron

    2014-01-01

    Marshall Space Flight Center has conducted a series of ground acoustic tests with the dual goals of informing analytical judgment, and validating analytical methods when estimating vibroacoustic responses of launch vehicle subsystems. The process of repeatedly correlating finite element-simulated responses with test-measured responses has assisted in the development of best practices for modeling and post-processing. In recent work, force transducers were integrated to measure interface forces at the base of avionics box equipment. Other force data was indirectly measured using strain gauges. The combination of these direct and indirect force measurements has been used to support and illustrate the advantages of implementing the Force Limiting approach for equipment qualification tests. The comparison of force response from integrated system level tests to measurements at the same locations during component level vibration tests provides an excellent illustration. A second comparison of the measured response cases from the system level acoustic tests to finite element simulations has also produced some principles for assessing the suitability of Finite Element Models (FEMs) for making vibroacoustics estimates. The results indicate that when FEM models are employed to guide force limiting choices, they should include sufficient detail to represent the apparent mass of the system in the frequency range of interest.

  6. Acoustic emission for on-line reactor monitoring: results of intermediate vessel test monitoring and reactor hot functional testing

    The objective of the acoustic emission (AE)/flaw characterization program is to provide an experimental feasibility evaluation of using the AE method on a continuous basis (during operation and during hydrotest) to detect and analyze flaw growth in reactor pressure vessels and primary piping. This effort is based on earlier results showing that AE has potential for being a valuable addition to nondestructive evaluation (NDE) methods with the added unique capability for continuous monitoring, high sensitivity and remote flaw location. Results are reported for the ZB-1 vessel test and the Watts Bar-1 hot functional test

  7. Assessment of the Acoustic Properties of Common Tissue-mimicking Test Phantoms

    Browne, Jacinta; Ramnarine, K.; Watson, A; Hoskins, P

    2003-01-01

    Ultrasound (US) test phantoms incorporating tissue-mimicking materials (TMMs) play an important role in the quality control (QC) and performance testing of US equipment. Three commercially available TMMs (ZerdineTM from CIRS Inc.; condensed-milk-based gel from Gammex RMI; urethane-rubber-based from ATS Labs) and a noncommercial agar-based TMM, were investigated. Acoustic properties were measured over the frequency range 2.25 to 15 MHz at a range of ambient temperatures (10 to 35°C). The acous...

  8. Application of Acoustic Emission Testing for the Assessment of Wind Turbine Blade

    Lee, Sang Il; Yun, Dong Jin; Hur, Yong Jin; Kim, Dong Jin [Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of)

    2006-11-15

    The purpose of this study was to verify the applicability of acoustic emission (AE) to detect damage in wind turbine blade. Nondestructive behavior of a GFRP wind turbine blade (WTB) was evaluated using AE analysis under stepwise cyclic loading. AE hits of the blade were correspondence with strain change within 80% of the maximum load. From the analysis of AE signals, the low energy signals due to electrical/mechanical noise were well distinguished from the signals of the blade delamination with higher amplitude or energy. When the AE test is performed with full blade test, AE will play an important role as a major nondestructive technique to assess damages of the WTB.

  9. Structural damage claims resulting from acoustic environments developed during static test firing of rocket engines

    Guest, S. H.; Slone, R. M., Jr.

    1972-01-01

    During static testing of multi-million pound thrust rocket engines areas adjacent to the test site have been subjected to the noise generated by rocket engines. Structural damage claims and subjective complaints were filed by those who alleged that the noise levels were excessive. The statistical analysis of these claims and complaints which were filed during these rocket engine development programs led to the determination of a relationship between claims and overall sound pressure level. Community exposure criteria are then assessed based on what can be considered allowable acoustic environments from large rocket engines.

  10. Measurement of impulse peak insertion loss from two acoustic test fixtures and four hearing protector conditions with an acoustic shock tube

    William J Murphy

    2015-01-01

    Full Text Available Impulse peak insertion loss (IPIL was studied with two acoustic test fixtures and four hearing protector conditions at the E-A-RCAL Laboratory. IPIL is the difference between the maximum estimated pressure for the open-ear condition and the maximum pressure measured when a hearing protector is placed on an acoustic test fixture (ATF. Two models of an ATF manufactured by the French-German Research Institute of Saint-Louis (ISL were evaluated with high-level acoustic impulses created by an acoustic shock tube at levels of 134 decibels (dB, 150 dB, and 168 dB. The fixtures were identical except that the E-A-RCAL ISL fixture had ear canals that were 3 mm longer than the National Institute for Occupational Safety and Health (NIOSH ISL fixture. Four hearing protection conditions were tested: Combat Arms earplug with the valve open, ETYPlugs ® earplug, TacticalPro headset, and a dual-protector ETYPlugs earplug with TacticalPro earmuff. The IPILs measured for the E-A-RCAL fixture were 1.4 dB greater than the National Institute for Occupational Safety and Health (NIOSH ISL ATF. For the E-A-RCAL ISL ATF, the left ear IPIL was 2.0 dB greater than the right ear IPIL. For the NIOSH ATF, the right ear IPIL was 0.3 dB greater than the left ear IPIL.

  11. Experimental Setup and Commissioning of a Test Facility for Gain Evaluation of Microchannel-Plate Photomultipliers in High Magnetic Field at Jefferson Lab

    Bringley, Eric; Cao, Tongtong; Ilieva, Yordonka; Nadel-Turonski, Pawel; Park, Kijun; Zorn, Carl

    2014-09-01

    At the Thomas Jefferson National Accelerator Facility (JLab) a research and development project for a Detector of Internally-Reflected Cherenkov light for the upcoming Electron Ion Collider is underway. One goal is the development of a compact readout camera that can operate in high magnetic fields. Small-size photon sensors, such as Microchannel-Plate Photomultipliers (MCP-PMT), are key components of the readout. Here we present our work to set up and commission a dedicated test facility at JLab where MCP-PMT gain is evaluated in magnetic fields of up to 5 T, and to develop a test procedure and analysis software to determine the gain. We operate the setup in a single-photon mode, where a light-emitting diode delivers photons to the sensor's photocathode. The PMT spectrum is measured with a flash Analog-to-Digital converter (fADC). We model the spectrum as a sum of an exponential background and a convolution of Poisson and Gaussian distributions of the pedestal and multiple photoelectron peaks, respectively. We determine the PMT's gain from the position of the single-photoelectron peak obtained by fitting the fADC spectrum to the model. Our gain uncertainty is <10%. The facility is now established and will have a long-lasting value for sensor tests and beyond-nuclear-physics applications.

  12. Test method of frequency response based on diamond surface acoustic wave devices

    CHEN Xi-ming; YANG Bao-he; WU Xiao-guo; WU Yi-zhuo

    2011-01-01

    In order to reduce the noises affixed to the signals when testing high frequency devices, a single-port test mode (S11) is used to test frequency response of high frequency (GHz) and dual-port surface acoustic wave devices (SAWDs) in this paper.The feasibility of the test is proved by simulating the Fabry-Perot model. The frequency response of the high-frequency dual-port resonant-type diamond SAWD is measured by S11 and the dual-port test mode (S21), respectively. The results show that the quality factor of the device is 51.29 and the 3 dB bandwidth is 27.8 MHz by S11 -mode measurement, which is better than the S21 mode, and is consistent with the frequency response curve by simulation.

  13. Evaluation of corrosion damage of aluminum alloy using acoustic emission testing

    GENG Rongsheng; FU Gangqiang

    2004-01-01

    Current studies are aiming at monitoring corrosion damage of aircraft main structures by using acoustic emission (AE) technique and at supplying useful data for determining calendar life of the aircraft. The characteristics of AE signals produced during accelerating corrosion process are described, and methods for evaluating corrosion damages and determining remaining life of main structures of aircraft using AE testing are outlined. Experimental results have shown that AE technique can detect corrosion damage of aluminum alloy much earlier than conventional non-destructive testing means, such as ultrasonic testing and eddy current testing. Relationship between corrosion damage and AE parameters was obtained through investigating corrosion damage extent and changes of AE signals during accelerating corrosion test, and showing that AE technique can be used to detect early corrosion, investigating corrosion developing trend, and in monitoring and evaluating corrosion damages.

  14. Study of the performances of acoustic emission testing for glass fibre reinforced plastic pipes containing defects

    Glass fibre reinforced plastic pipes are more and more often used, in nuclear power plants, for building or replacement of water pipings classified 'nuclear safety'. Tests have been performed to evaluate the performances of acoustic emission testing for in service inspection of these components. The tests were focused on glass fibre reinforced polyester and vinyl-ester pipes, in as received conditions or containing impacts, and intentionally introduced defects. They have been carried out by CETIM, following the ASTM Standard E 1118 (code CARP), to a maximum pressure lever of 25 Bar The results show that the CARP procedure can be used for detection of defects and evaluation of their noxiousness towards internal pressure: most of the tubes containing low energy impacts could not be distinguished from tubes without defect; on the other hand the important noxiousness of lacks of impregnation of roving layer appeared clearly. Complementary tests have been performed on some tubes at a more important pressure lever, for which the damage of the tubes in enough to deteriorate there elastic properties. The results showed that CARP procedure give valuable informations on damage level. It would be interesting to evaluate acoustic emission on tubes containing realistic in-service degradations. (author). 11 refs., 15 figs., 6 tabs., 2 appends

  15. Tests of a Compton imaging prototype in a monoenergetic 4.44 MeV photon field—a benchmark setup for prompt gamma-ray imaging devices

    Golnik, C.; Bemmerer, D.; Enghardt, W.; Fiedler, F.; Hueso-González, F.; Pausch, G.; Römer, K.; Rohling, H.; Schöne, S.; Wagner, L.; Kormoll, T.

    2016-06-01

    The finite range of a proton beam in tissue opens new vistas for the delivery of a highly conformal dose distribution in radiotherapy. However, the actual particle range, and therefore the accurate dose deposition, is sensitive to the tissue composition in the proton path. Range uncertainties, resulting from limited knowledge of this tissue composition or positioning errors, are accounted for in the form of safety margins. Thus, the unverified particle range constrains the principle benefit of proton therapy. Detecting prompt γ-rays, a side product of proton-tissue interaction, aims at an on-line and non-invasive monitoring of the particle range, and therefore towards exploiting the potential of proton therapy. Compton imaging of the spatial prompt γ-ray emission is a promising measurement approach. Prompt γ-rays exhibit emission energies of several MeV. Hence, common radioactive sources cannot provide the energy range a prompt γ-ray imaging device must be designed for. In this work a benchmark measurement-setup for the production of a localized, monoenergetic 4.44 MeV γ-ray source is introduced. At the Tandetron accelerator at the HZDR, the proton-capture resonance reaction 15N(p,α γ4.439)12C is utilized. This reaction provides the same nuclear de-excitation (and γ-ray emission) occurrent as an intense prompt γ-ray line in proton therapy. The emission yield is quantitatively described. A two-stage Compton imaging device, dedicated for prompt γ-ray imaging, is tested at the setup exemplarily. Besides successful imaging tests, the detection efficiency of the prototype at 4.44 MeV is derived from the measured data. Combining this efficiency with the emission yield for prompt γ-rays, the number of valid Compton events, induced by γ-rays in the energy region around 4.44 MeV, is estimated for the prototype being implemented in a therapeutic treatment scenario. As a consequence, the detection efficiency turns out to be a key parameter for prompt

  16. Testing the neutrality of matter by acoustic means in a spherical resonator

    Bressi, G; Della Valle, F; Galeazzi, G; Ruoso, G; Sartori, G

    2011-01-01

    New measurements to test the neutrality of matter by acoustic means are reported. The apparatus is based on a spherical capacitor filled with gaseous SF$_6$ excited by an oscillating electric field. The apparatus has been calibrated measuring the electric polarizability. Assuming charge conservation in the $\\beta$ decay of the neutron, the experiment gives a limit of $\\epsilon_\\text{p-e}\\lesssim1\\cdot10^{-21}$ for the electron-proton charge difference, the same limit holding for the charge of the neutron. Previous measurements are critically reviewed and found incorrect: the present result is the best limit obtained with this technique.

  17. Characterisation and testing of the KM3NeT acoustic positioning system

    Viola S.

    2016-01-01

    Full Text Available In underwater neutrino telescopes, the search of point-like sources through the Cherenkov detection technique requires a precise knowledge of the positions of thousands of optical sensors, spread in a volume of a few cubic kilometres. In KM3NeT the optical sensors are hosted in 700 m high semi-rigid structures, called detection units, which move under the effects of underwater currents. These movements are continuously monitored through an underwater positioning system based on acoustic emitters and receivers. In this work, the tests performed on the key elements of the positioning system are presented.

  18. Acoustic emission monitoring of preservice testing at Watts Bar Unit 1 Nuclear Reactor

    Acoustic emission (AE) monitoring of selected pressure boundary areas at TVA's Watts Bar, Unit 1 Nuclear Plant in the US during hot functional preservice testing is described. Background, methodology, and results are included. The work discussed here is a major milestone in a program supported by the US 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 to AE monitoring during reactor operation. 3 refs., 6 figs

  19. Statistical Test of Distance-Duality Relation with Type Ia Supernovae and Baryon Acoustic Oscillations

    Ma, Cong; Corasaniti, Pier-Stefano

    2016-01-01

    We use cosmological luminosity distance ($d_L$) from the JLA Type Ia supernovae compilation and angular-diameter distance ($d_A$) based on BOSS and WiggleZ baryon acoustic oscillation measurements to test the distance-duality relation $\\eta \\equiv d_L / [ (1 + z)^2 d_A ] = 1$. The $d_L$ measurements are matched to $d_A$ redshift by a statistically-motivated compression procedure. By means of Monte Carlo methods, non-trivial and correlated distributions of $\\eta$ can be explored in a straightf...

  20. Test setup for accelerated test of high power IGBT modules with online monitoring of Vce and Vf voltage during converter operation

    de Vega, Angel Ruiz; Ghimire, Pramod; Pedersen, Kristian Bonderup;

    2014-01-01

    Several accelerated test methods exist in order to study the failures mechanisms of the high power IGBT modules like temperature cycling test or power cycles based on DC current pulses. The main drawback is that the test conditions do not represent the real performance and stress conditions of th...

  1. Cold test with a benchtop set-up for fluidized bed reactor using quartz sand to simulate gasification of coal cokes by concentrated solar radiation

    Gokon, Nobuyuki; Tanabe, Tomoaki; Shimizu, Tadaaki; Kodama, Tatsuya

    2016-05-01

    The impacts of internal circulation of a mixture of coal-coke particles and quartz sand on the fluidization state in a fluidized bed reactor are investigated by a cold test with a benchtop set-up in order to design 10-30 kWth scale prototype windowed fluidized-bed reactor. Firstly, a basic relationship between pressure loss of inlet gas and gas velocity was experimentally examined using quartz sand with different particle sizes by a small-scale quartz tube with a distributor at ambient pressure and temperature. Based on the results, an appropriate particle range of quartz sand and layer height/layer diameter ratio (L/D ratio) was determined for a design of the fluidized bed reactor. Secondly, a windowed reactor mock-up was designed and fabricated for solar coke gasification using quartz sand as a bed material. The pressure loss between the inlet and outlet gases was examined, and descending cokes and sand particles on the sidewall of the reactor was observed in the reactor mock-up. The moving velocity and distance of descending particles/sands from the top to bottom of fluidized bed were measured by the visual observation of the colored tracer particles on outside wall of the reactor.

  2. Acoustic emission for on-line reactor monitoring: results of intermediate vessel test monitoring and reactor hot functional testing

    This article discusses a program designed to develop the use of acoustic emission (AE) methods for continuous surveillance to detect and evaluate flaw growth in reactor pressure boundaries. Technology developed in the laboratory for identifying AE from crack growth and for using AE information to estimate flaw severity is now being evaluated on an intermediate vessel test and on a reactor facility. A vessel, designated ZB-1, has been tested under fatigue loadings with simulated reactor conditions at Mannheim, West Germany, in collaboration with the German Materialpruefungsanstalt (MPA), Stuttgart. Fatigue cracking from machined flaws and in a fabrication weld were both detected clearly by AE. AE data were measured on a US nuclear reactor (Watts Bar, Unit 1) during hot functional preservice testing. This demonstrated that coolant flow noise is a manageable problem and that AE can be detected under operational coolant flow and temperature conditions. (author)

  3. The Alcock Paczy\\'nski test with Baryon Acoustic Oscillations: systematic effects for future surveys

    Lepori, Francesca; Viel, Matteo; Baccigalupi, Carlo; Durrer, Ruth

    2016-01-01

    We investigate the Alcock Paczy\\'nski (AP) test applied to the Baryon Acoustic Oscillation (BAO) feature in the galaxy correlation function. By using a general formalism that includes relativistic effects, we quantify the importance of the linear redshift space distortions and gravitational lensing corrections to the galaxy number density fluctuation. We show that redshift space distortions significantly affect the shape of the correlation function, both in radial and transverse directions, causing different values of galaxy bias to induce offsets up to 1% in the AP test. On the other hand, we find that the lensing correction around the BAO scale modifies the amplitude but not the shape of the correlation function and therefore does not introduce any systematic effect. Furthermore, we investigate in details how the AP test is sensitive to redshift binning: a window function in transverse direction suppresses correlations and shifts the peak position toward smaller angular scales. We determine the correction t...

  4. Sound propagation tests for acoustic detection of simulated sodium-water reaction

    The characteristics of sound propagation in a steam generator were tested in order to investigate the feasibility of an acoustic leak detection by small leak sodium-water reactions. The test model was composed of the vessel filled with water, the inner pipe, the shroud, and two heat transfer coils. Transducers, gas leak nozzles and an underwater speaker were set up for the simulated sound source. The results indicate that the acoustic signal detected at the vessel wall has a comparable SN ratio to the guide pipe or the heat transfer tubes, and that the difference of the RMS values depend on the standing wave, rather than the attenuation by distance or diffractions, Therefore, it was estimated that the sound field in the vessel was reverberant, and the difference between one and two helical coils depends on the sound energy absorption by them. The RMS values in the high frequency range (more than 50 kHz) do not increase in proportion to the gas leak rate, more than about 200 cc/s, because of the attenuation by gas bubbles. (author)

  5. Acoustic Modifications of the Ames 40x80 Foot Wind Tunnel and Test Techniques for High-Speed Research Model Testing

    Soderman, Paul T.; Olson, Larry (Technical Monitor)

    1995-01-01

    The NFAC 40- by 80- Foot Wind Tunnel at Ames is being refurbished with a new, deep acoustic lining in the test section which will make the facility nearly anechoic over a large frequency range. The modification history, key elements, and schedule will be discussed. Design features and expected performance gains will be described. Background noise reductions will be summarized. Improvements in aeroacoustic research techniques have been developed and used recently at NFAC on several wind tunnel tests of High Speed Research models. Research on quiet inflow microphones and struts will be described. The Acoustic Survey Apparatus in the 40x80 will be illustrated. A special intensity probe was tested for source localization. Multi-channel, high speed digital data acquisition is now used for acoustics. And most important, phased microphone arrays have been developed and tested which have proven to be very powerful for source identification and increased signal-to-noise ratio. Use of these tools for the HEAT model will be illustrated. In addition, an acoustically absorbent symmetry plane was built to satisfy the HEAT semispan aerodynamic and acoustic requirements. Acoustic performance of that symmetry plane will be shown.

  6. Testing the effectiveness of an acoustic deterrent for gray whales along the Oregon coast

    Lagerquist, Barbara [Oregon State University Marine Mammal Institute; Winsor, Martha [Oregon State University Marine Mammal Institute; Mate, Bruce [Oregon State University Marine Mammal Institute

    2012-12-31

    This study was conducted to determine whether a low-powered sound source could be effective at deterring gray whales from areas that may prove harmful to them. With increased interest in the development of marine renewal energy along the Oregon coast the concern that such development may pose a collision or entanglement risk for gray whales. A successful acoustic deterrent could act as a mitigation tool to prevent harm to whales from such risks. In this study, an acoustic device was moored on the seafloor in the pathway of migrating gray whales off Yaquina Head on the central Oregon coast. Shore-based observers tracked whales with a theodolite (surveyor’s tool) to accurately locate whales as they passed the headland. Individual locations of different whales/whale groups as well as tracklines of the same whale/whale groups were obtained and compared between times with the acoustic device was transmitting and when it was off. Observations were conducted on 51 d between January 1 and April 15, 2012. A total of 143 individual whale locations were collected for a total of 243 whales, as well as 57 tracklines for a total of 142 whales. Inclement weather and equipment problems resulted in very small sample sizes, especially during experimental periods, when the device was transmitting. Because of this, the results of this study were inconclusive. We feel that another season of field testing is warranted to successfully test the effectiveness of the deterrent, but recommend increasing the zone of influence to 3 km to ensure the collection of adequate sample sizes. Steps have been taken to acquire the necessary federal research permit modification to authorize the increased zone of influence and to modify the acoustic device for the increased power. With these changes we are confident we will be able to determine whether the deterrent is effective at deflecting gray whales. A successful deterrent device may serve as a valuable mitigation tool to protect gray whales, and

  7. Test-Anchored Vibration Response Predictions for an Acoustically Energized Curved Orthogrid Panel with Mounted Components

    Frady, Gregory P.; Duvall, Lowery D.; Fulcher, Clay W. G.; Laverde, Bruce T.; Hunt, Ronald A.

    2011-01-01

    rich body of vibroacoustic test data was recently generated at Marshall Space Flight Center for component-loaded curved orthogrid panels typical of launch vehicle skin structures. The test data were used to anchor computational predictions of a variety of spatially distributed responses including acceleration, strain and component interface force. Transfer functions relating the responses to the input pressure field were generated from finite element based modal solutions and test-derived damping estimates. A diffuse acoustic field model was applied to correlate the measured input sound pressures across the energized panel. This application quantifies the ability to quickly and accurately predict a variety of responses to acoustically energized skin panels with mounted components. Favorable comparisons between the measured and predicted responses were established. The validated models were used to examine vibration response sensitivities to relevant modeling parameters such as pressure patch density, mesh density, weight of the mounted component and model form. Convergence metrics include spectral densities and cumulative root-mean squared (RMS) functions for acceleration, velocity, displacement, strain and interface force. Minimum frequencies for response convergence were established as well as recommendations for modeling techniques, particularly in the early stages of a component design when accurate structural vibration requirements are needed relatively quickly. The results were compared with long-established guidelines for modeling accuracy of component-loaded panels. A theoretical basis for the Response/Pressure Transfer Function (RPTF) approach provides insight into trends observed in the response predictions and confirmed in the test data. The software developed for the RPTF method allows easy replacement of the diffuse acoustic field with other pressure fields such as a turbulent boundary layer (TBL) model suitable for vehicle ascent. Structural responses

  8. Integration of Acoustic Neutrino Detection Methods into ANTARES

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

  9. Integration of Acoustic Neutrino Detection Methods into ANTARES

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

    2007-01-01

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

  10. HADES - Hydrophone for Acoustic Detection at South Pole

    Semburg, Benjamin

    2008-01-01

    The South Pole Acoustic Test Setup (SPATS) is located in the upper part of the optical neutrino observatory IceCube, currently under construction. SPATS consists of four strings at depths between 80 m and 500 m below the surface of the ice with seven stages per string. Each stage is equipped with an acoustic sensor and a transmitter. Three strings (string A-C) were deployed in the austral summer 2006/07. SPATS was extended by a fourth string (string D) with second generation sensors and transmitters in 2007/08. One second generation sensor type HADES (Hydrophone for Acoustic Detection at South Pole) consists of a ring-shaped piezo-electric element coated with polyurethane. The development of the sensor, optimization of acoustic transmission by acoustic impedance matching and first in-situ results will be discussed.

  11. Acoustic emission testing and estimation of the damage of wind turbine blades

    Wind turbines experience long term fluctuating variable amplitude fatigue loads with occasional large amplitude stochastic peak loads. A methodology for wind turbine blade monitoring using acoustic emission (AE) detection of damage processes in the structure has been developed by the AEGIS consortium, supported by the European Commission. Characteristic results are presented of AE activity during peak loading events and fatigue blade tests to failure in the laboratory. The results presented indicate the kind of results, which could be obtained from monitoring in-service machines. In particular, a dedicated pattern recognition software has been developed which could identify differences from turbine to turbine and help target preventative maintenance. Validation of the software from laboratory tests on blades is presented. (authors)

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

    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.

  13. Excitation and detection of shear horizontal waves with electromagnetic acoustic transducers for nondestructive testing of plates

    Ma, Qingzeng; Jiao, Jingpin; Hu, Ping; Zhong, Xi; Wu, Bin; He, Cunfu

    2014-03-01

    The fundamental shear horizontal(SH0) wave has several unique features that are attractive for long-range nondestructive testing(NDT). By a careful design of the geometric configuration, electromagnetic acoustic transducers(EMATs) have the capability to generate a wide range of guided wave modes, such as Lamb waves and shear-horizontal(SH) waves in plates. However, the performance of EMATs is influenced by their parameters. To evaluate the performance of periodic permanent magnet(PPM) EMATs, a distributed-line-source model is developed to calculate the angular acoustic field cross-section in the far-field. Numerical analysis is conducted to investigate the performance of such EMATs with different geometric parameters, such as period and number of magnet arrays, and inner and outer coil widths. Such parameters have a great influence on the directivity of the generated SH0 waves that arises mainly in the amplitude and width of both main and side lobes. According to the numerical analysis, these parameters are optimized to obtain better directivity. Optimized PPM EMATs are designed and used for NDT of strip plates. Experimental results show that the lateral boundary of the strip plate has no perceivable influence on SH0-wave propagation, thus validating their used in NDT. The proposed model predicts the radiation pattern of PPM EMATs, and can be used for their parameter optimization.

  14. Acoustic Emission and Ultrasonic Characterization of Jurassic Navajo Formation Deformation During Axisymmetric Compression Testing

    Rinehart, A. J.; Dewers, T. A.; Holcomb, D. J.; Broome, S. T.

    2011-12-01

    Linking continuum-scale and microscale brittle damage in rock remains a challenge impacting CO2 sequestration, secondary recovery, structural monitoring, and other geotechnical engineering applications. We examine if the mode of micromechanical failure scales directly up to continuum-scale damage-induced velocity anisotropy. Axisymmetric drained lab-dry compression experiments are performed on facies of moderately cemented finely laminated quartz arenite from the Jurassic Navajo Formation, a target reservoir rock for CO2 sequestration in Utah. The tests are 1 unconfined uniaxial compression test, 1 hydrostatic compression test, and 3 triaxial compression tests. Microscale damage is monitored using acoustic emissions (AE) and continuum scale damage is monitored with ultrasonic velocity scans. During the non-hydrostatic tests, three to five unload loops are performed pre-failure, with one unload loop performed post-failure. While stresses are increasing, AEs are monitored continuously using 1.6-mm diameter, 0.5-mm thick PZT-5A pins attached circumferentially around the cylindrical sample, and with 6-mm diameter, 2-mm thick PZT-5A discs at the ends of the sample. Before and after each unload loop, the test is paused and the AE transducers sequentially emit an ultrasonic pulse to measure wave speeds. The resulting elastic wave is detected by the other AE transducers. Post-test, the changing anisotropic velocity structure of the rock during compression and failure is compared to the locations, frequency, and relative moment tensors of the AEs measured between ultrasonic scans. Pre- and post-test visual and x-ray CT scan observations of the sample are compared to the acoustic metrics. These tiered observations of rock damage will further elucidate the scaling of microscale brittle failure to the continuum-scale This work was supported as part of the Center for Frontiers of Subsurface Energy Security, an Energy Frontier Research Center funded by the U.S. Department of

  15. Test-bench system for a borehole azimuthal acoustic reflection imaging logging tool

    Liu, Xianping; Ju, Xiaodong; Qiao, Wenxiao; Lu, Junqiang; Men, Baiyong; Liu, Dong

    2016-06-01

    The borehole azimuthal acoustic reflection imaging logging tool (BAAR) is a new generation of imaging logging tool, which is able to investigate stratums in a relatively larger range of space around the borehole. The BAAR is designed based on the idea of modularization with a very complex structure, so it has become urgent for us to develop a dedicated test-bench system to debug each module of the BAAR. With the help of a test-bench system introduced in this paper, test and calibration of BAAR can be easily achieved. The test-bench system is designed based on the client/server model. The hardware system mainly consists of a host computer, an embedded controlling board, a bus interface board, a data acquisition board and a telemetry communication board. The host computer serves as the human machine interface and processes the uploaded data. The software running on the host computer is designed based on VC++. The embedded controlling board uses Advanced Reduced Instruction Set Machines 7 (ARM7) as the micro controller and communicates with the host computer via Ethernet. The software for the embedded controlling board is developed based on the operating system uClinux. The bus interface board, data acquisition board and telemetry communication board are designed based on a field programmable gate array (FPGA) and provide test interfaces for the logging tool. To examine the feasibility of the test-bench system, it was set up to perform a test on BAAR. By analyzing the test results, an unqualified channel of the electronic receiving cabin was discovered. It is suggested that the test-bench system can be used to quickly determine the working condition of sub modules of BAAR and it is of great significance in improving production efficiency and accelerating industrial production of the logging tool.

  16. Statistical Test of Distance-Duality Relation with Type Ia Supernovae and Baryon Acoustic Oscillations

    Ma, Cong

    2016-01-01

    We use cosmological luminosity distance ($d_L$) from the JLA Type Ia supernovae compilation and angular-diameter distance ($d_A$) based on BOSS and WiggleZ baryon acoustic oscillation measurements to test the distance-duality relation $\\eta \\equiv d_L / [ (1 + z)^2 d_A ] = 1$. The $d_L$ measurements are matched to $d_A$ redshift by a statistically-motivated compression procedure. By means of Monte Carlo methods, non-trivial and correlated distributions of $\\eta$ can be explored in a straightforward manner without resorting to a particular evolution template $\\eta(z)$. Assuming Planck cosmological parameter uncertainty, we find 5% constraints in favor of $\\eta = 1$, consistent with the weaker 7--10% constraints obtained using WiggleZ data. These results stand in contrast to previous claims that $\\eta < 1$ has been found close to or above $1\\sigma$ level.

  17. Test charge potential in the presence of electron acoustic waves in multispecies dusty plasma

    An expression for the test charge potential is obtained in a multispecies dusty plasma, whose constituents are the Boltzmann distributed hot electrons, mobile cold electrons, immobile cold ions, and charge fluctuating isolated dust grains. The plasma response function involving the electron-acoustic waves becomes modified due to the inclusion of the dust-charge perturbations. The analytical and numerical investigations reveal that the Debye-Hueckel screening and wakefield potentials are significantly affected by the plasma parameters such as the equilibrium dust number density, the dust grain radius, and the hot electron temperature. The relevance of the results to laboratory plasma, where the two distinct groups of electrons exist besides the static ions and isolated dust grains, is discussed.

  18. Evaluation of shrinkage and cracking in concrete of ring test by acoustic emission method

    Watanabe, Takeshi; Hashimoto, Chikanori

    2015-03-01

    Drying shrinkage of concrete is one of the typical problems related to reduce durability and defilation of concrete structures. Lime stone, expansive additive and low-heat Portland cement are used to reduce drying shrinkage in Japan. Drying shrinkage is commonly evaluated by methods of measurement for length change of mortar and concrete. In these methods, there is detected strain due to drying shrinkage of free body, although visible cracking does not occur. In this study, the ring test was employed to detect strain and age cracking of concrete. The acoustic emission (AE) method was adopted to detect micro cracking due to shrinkage. It was recognized that in concrete using lime stone, expansive additive and low-heat Portland cement are effective to decrease drying shrinkage and visible cracking. Micro cracking due to shrinkage of this concrete was detected and evaluated by the AE method.

  19. 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

    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

  20. Experimental Results for Direction of Arrival Estimation with a Single Acoustic Vector Sensor in Shallow Water

    Alper Bereketli; Guldogan, Mehmet B.; Taner Kolcak; Tamer Gudu; Ahmet Levent Avsar

    2015-01-01

    We study the performances of several computationally efficient and simple techniques for estimating direction of arrival (DOA) of an underwater acoustic source using a single acoustic vector sensor (AVS) in shallow water. Underwater AVS is a compact device, which consists of one hydrophone and three accelerometers in a packaged form, measuring scalar pressure and three-dimensional acceleration simultaneously at a single position. A very controlled experimental setup is prepared to test how we...

  1. Evaluation of Acoustic Emission NDE of Composite Crew Module Service Module/Alternate Launch Abort System (CCM SM/ALAS) Test Article Failure Tests

    Horne, Michael R.; Madaras, Eric I.

    2010-01-01

    Failure tests of CCM SM/ALAS (Composite Crew Module Service Module / Alternate Launch Abort System) composite panels were conducted during July 10, 2008 and July 24, 2008 at Langley Research Center. This is a report of the analysis of the Acoustic Emission (AE) data collected during those tests.

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

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

    2011-01-01

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

  3. Resolution of Forces and Strain Measurements from an Acoustic Ground Test

    Smith, Andrew M.; LaVerde, Bruce T.; Hunt, Ronald; Waldon, James M.

    2013-01-01

    The Conservatism in Typical Vibration Tests was Demonstrated: Vibration test at component level produced conservative force reactions by approximately a factor of 4 (approx.12 dB) as compared to the integrated acoustic test in 2 out of 3 axes. Reaction Forces Estimated at the Base of Equipment Using a Finite Element Based Method were Validated: FEM based estimate of interface forces may be adequate to guide development of vibration test criteria with less conservatism. Element Forces Estimated in Secondary Structure Struts were Validated: Finite element approach provided best estimate of axial strut forces in frequency range below 200 Hz where a rigid lumped mass assumption for the entire electronics box was valid. Models with enough fidelity to represent diminishing apparent mass of equipment are better suited for estimating force reactions across the frequency range. Forward Work: Demonstrate the reduction in conservatism provided by; Current force limited approach and an FEM guided approach. Validate proposed CMS approach to estimate coupled response from uncoupled system characteristics for vibroacoustics.

  4. Can you hear me now? Range-testing a submerged passive acoustic receiver array in a Caribbean coral reef habitat

    Selby, Thomas H.; Hart, Kristen M.; Fujisaki, Ikuko; Smith, Brian J.; Pollock, Clayton J; Hillis-Star, Zandy M; Lundgren, Ian; Oli, Madan K.

    2016-01-01

    Submerged passive acoustic technology allows researchers to investigate spatial and temporal movement patterns of many marine and freshwater species. The technology uses receivers to detect and record acoustic transmissions emitted from tags attached to an individual. Acoustic signal strength naturally attenuates over distance, but numerous environmental variables also affect the probability a tag is detected. Knowledge of receiver range is crucial for designing acoustic arrays and analyzing telemetry data. Here, we present a method for testing a relatively large-scale receiver array in a dynamic Caribbean coastal environment intended for long-term monitoring of multiple species. The U.S. Geological Survey and several academic institutions in collaboration with resource management at Buck Island Reef National Monument (BIRNM), off the coast of St. Croix, recently deployed a 52 passive acoustic receiver array. We targeted 19 array-representative receivers for range-testing by submersing fixed delay interval range-testing tags at various distance intervals in each cardinal direction from a receiver for a minimum of an hour. Using a generalized linear mixed model (GLMM), we estimated the probability of detection across the array and assessed the effect of water depth, habitat, wind, temperature, and time of day on the probability of detection. The predicted probability of detection across the entire array at 100 m distance from a receiver was 58.2% (95% CI: 44.0–73.0%) and dropped to 26.0% (95% CI: 11.4–39.3%) 200 m from a receiver indicating a somewhat constrained effective detection range. Detection probability varied across habitat classes with the greatest effective detection range occurring in homogenous sand substrate and the smallest in high rugosity reef. Predicted probability of detection across BIRNM highlights potential gaps in coverage using the current array as well as limitations of passive acoustic technology within a complex coral reef

  5. Can you hear me now? Range-testing a submerged passive acoustic receiver array in a Caribbean coral reef habitat.

    Selby, Thomas H; Hart, Kristen M; Fujisaki, Ikuko; Smith, Brian J; Pollock, Clayton J; Hillis-Starr, Zandy; Lundgren, Ian; Oli, Madan K

    2016-07-01

    Submerged passive acoustic technology allows researchers to investigate spatial and temporal movement patterns of many marine and freshwater species. The technology uses receivers to detect and record acoustic transmissions emitted from tags attached to an individual. Acoustic signal strength naturally attenuates over distance, but numerous environmental variables also affect the probability a tag is detected. Knowledge of receiver range is crucial for designing acoustic arrays and analyzing telemetry data. Here, we present a method for testing a relatively large-scale receiver array in a dynamic Caribbean coastal environment intended for long-term monitoring of multiple species. The U.S. Geological Survey and several academic institutions in collaboration with resource management at Buck Island Reef National Monument (BIRNM), off the coast of St. Croix, recently deployed a 52 passive acoustic receiver array. We targeted 19 array-representative receivers for range-testing by submersing fixed delay interval range-testing tags at various distance intervals in each cardinal direction from a receiver for a minimum of an hour. Using a generalized linear mixed model (GLMM), we estimated the probability of detection across the array and assessed the effect of water depth, habitat, wind, temperature, and time of day on the probability of detection. The predicted probability of detection across the entire array at 100 m distance from a receiver was 58.2% (95% CI: 44.0-73.0%) and dropped to 26.0% (95% CI: 11.4-39.3%) 200 m from a receiver indicating a somewhat constrained effective detection range. Detection probability varied across habitat classes with the greatest effective detection range occurring in homogenous sand substrate and the smallest in high rugosity reef. Predicted probability of detection across BIRNM highlights potential gaps in coverage using the current array as well as limitations of passive acoustic technology within a complex coral reef environment

  6. The application of the acoustic emission technique to stone decay by sodium sulphate in laboratory tests

    Grossi, C. M.

    1997-03-01

    Full Text Available Acoustic emission was monitored during salt crystallisation cycles in order to study the mechanisms of rock deterioration by sodium sulphate in laboratory tests. Some porous carbonate stones used in Spanish monuments (Cathedral of Oviedo, Murcia and Seo Vella of Lérida were selected for this study. The acoustic emission detected during the different stages of the cycles (immersion, drying and cooling was interpreted to be the result of the salt behaviour inside the stone. The use of this technique has confirmed that this behaviour depends on salt characteristics (solubility, hydration state and polymorphism of anhydrous sodium sulphate and stone porosity and pore network.

    Para determinar los mecanismos de deterioro de las rocas debidos a la acción del sulfato de sodio, se ha registrado la emisión acústica durante ensayos de cristalización de sales en el laboratorio. Para ello, se han seleccionado tres piedras porosas carbonatadas utilizadas como materiales de construcción en monumentos españoles (Catedrales de Oviedo, Murcia y Seo Vella de Lérida. La emisión acústica detectada durante las diferentes etapas de los ciclos (inmersión, secado y enfriamiento se ha interpretado como debida al comportamiento de la sal en el interior de la piedra. Mediante esta técnica se ha confirmado que este comportamiento depende de las características de la sal (solubilidad, diferentes estados de hidratación y el polimorfismo del sulfato de sodio anhidro y de la porosidad y configuración del sistema poroso de las rocas.

  7. Acoustic emission monitoring of a fatigue test of an F/A-18 bulkhead

    Scala, C. M.; McCardle, J. F.; Bowles, S. J.

    This paper describes the application of acoustic emission (AE) to identify cracking in several fatigue-critical regions on the port and starboard sides of an l/A-18 aircraft bulkhead undergoing fatigue testing. AE data acquisition was carried out using an array of three sensors on each side of the bulkhead. AE features stored by each array included relative arrival times of AE events at the three sensors, event rise time at the first-hit sensor, and the load level and the position on the load cycle of event occurrence. AE data processing involved a comparison between the features of those AE events stored during the fatigue testing and predicted features for cracking in the complex-shaped bulkhead. Feature prediction was based on wave propagation characteristics obtained by Pentel-lead calibration, and the known load cycle dependence of crack-related AE events. The AE processing was completed following failure of the bulkhead, and gave the correct locations of all cracks, greater than about 1 mm in depth, present in the bulkhead during the fatigue testing. The study shows that AE associated with cracking can be distinguished, even when many extraneous sources are present, and demonstrates that AE is a promising technique for nondestructive evaluation of a complex structure such as the F/A-18 bulkhead.

  8. A mechanical experimental setup to simulate vocal folds vibrations. Preliminary results

    Ruty, Nicolas; Pelorson, Xavier; Lopez-Arteaga, Ines; Hirschberg, Avraham

    2005-01-01

    This paper contributes to the understanding of vocal folds oscillation during phonation. In order to test theoretical models of phonation, a new experimental set-up using a deformable vocal folds replica is presented. The replica is shown to be able to produce self sustained oscillations under controlled experimental conditions. Therefore different parameters, such as those related to elasticity, to acoustical coupling or to the subglottal pressure can be quantitatively studied. In this work we focused on the oscillation fundamental frequency and the upstream pressure in order to start (on-set threshold) either end (off-set threshold) oscillations in presence of a downstream acoustical resonator. As an example, it is shown how this data can be used in order to test the theoretical predictions of a simple one-mass model.

  9. Testing of containers made of glass-fiber reinforced plastic with the aid of acoustic emission analysis

    Wolitz, K.; Brockmann, W.; Fischer, T.

    1979-01-01

    Acoustic emission analysis as a quasi-nondestructive test method makes it possible to differentiate clearly, in judging the total behavior of fiber-reinforced plastic composites, between critical failure modes (in the case of unidirectional composites fiber fractures) and non-critical failure modes (delamination processes or matrix fractures). A particular advantage is that, for varying pressure demands on the composites, the emitted acoustic pulses can be analyzed with regard to their amplitude distribution. In addition, definite indications as to how the damages occurred can be obtained from the time curves of the emitted acoustic pulses as well as from the particular frequency spectrum. Distinct analogies can be drawn between the various analytical methods with respect to whether the failure modes can be classified as critical or non-critical.

  10. Sonification of acoustic emission data

    Raith, Manuel; Große, Christian

    2014-05-01

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

  11. Teaching Acoustic Properties of Materials in Secondary School: Testing Sound Insulators

    Hernandez, M. I.; Couso, D.; Pinto, R.

    2011-01-01

    Teaching the acoustic properties of materials is a good way to teach physics concepts, extending them into the technological arena related to materials science. This article describes an innovative approach for teaching sound and acoustics in combination with sound insulating materials in secondary school (15-16-year-old students). Concerning the…

  12. Application of acoustic emission as a monitoring system during hydrostatic tests of nuclear reactor components

    The paper presents the state of art for the surveillance of nuclear reactor components by acoustic emission during hydrostatic tests as obtained during several inspections made by KWU and Battelle-Frankfurt/Main. The following four points are relevant: a) Measures designed to suppress background noise, b) adapted pressure increase rate, c) extensive and practically oriented calibration measurements, d) suitable measuring technique. These necessary preconditions are discussed and results on the wave propagation, location accuracy, attenuation of AE-signals due to geometrical configurations (nozzles) and on the correlation between AE-sources and defects as detected by other NDE-methods presented. Two selected examples of AE-tests on reactor components will demonstrate the results which can be obtained at the present time. These investigations have shown till now that: 1) AE is a sensitive NDE-method, able to detect even very small flaws. The AE-sources lie for the most part in areas of seam welds, welded-on attachments, nozzles, closure studs, or other prominent areas (see rolling track). 2) Indications which were found by AE need not necessarily be detectable by other NDE-methods, e.g. ultrasound. 3) Small leaks can be identified in a short time and can be located within certain limits. An essential point however is that leaks with higher noise level must be sealed off. (orig.)

  13. Acoustic Emission Monitoring of Lightning-Damaged CFRP Laminates during Compression-after-Impact Test

    Carbon-fiber reinforced plastic(CFRP) laminates made of nano-particle-coated carbon fibers and damaged by a simulated lightning strike were tested under compression-after-impact(CAI) mode, during which the damage progress due to compressive loading has been monitored by acoustic emission(AE). The impact damage was induced not by mechanical loading but by a simulated lightning strike. Conductive nano-particles were coated directly on the fibers, from which CFRP coupons were made. The coupon were subjected to the strikes with a high voltage/current impulse of 10-40 kA within a few . The effects of nano-particle coating and the degree of damage induced by the simulated lightning strikes on AE activities were examined, and the relationship between the compressive residual strength and AE behavior has been evaluated in terms of AE event counts and the onset of AE activity with the compressive loading. The degree of impact damage was also measured in terms of damage area by using ultrasonic C-scan images. The assessment during the CAI tests of damaged CFRP showed that AE monitoring appeared to be useful to differentiate the degree of damage hence the mechanical integrity of composite structures damaged by lightning strikes.

  14. Azimuthal cement evaluation with an acoustic phased-arc array transmitter: numerical simulations and field tests

    Che, Xiao-Hua; Qiao, Wen-Xiao; Ju, Xiao-Dong; Wang, Rui-Jia

    2016-03-01

    We developed a novel cement evaluation logging tool, named the azimuthally acoustic bond tool (AABT), which uses a phased-arc array transmitter with azimuthal detection capability. We combined numerical simulations and field tests to verify the AABT tool. The numerical simulation results showed that the radiation direction of the subarray corresponding to the maximum amplitude of the first arrival matches the azimuth of the channeling when it is behind the casing. With larger channeling size in the circumferential direction, the amplitude difference of the casing wave at different azimuths becomes more evident. The test results showed that the AABT can accurately locate the casing collars and evaluate the cement bond quality with azimuthal resolution at the casing—cement interface, and can visualize the size, depth, and azimuth of channeling. In the case of good casing—cement bonding, the AABT can further evaluate the cement bond quality at the cement—formation interface with azimuthal resolution by using the amplitude map and the velocity of the formation wave.

  15. Evaluating damage potential of cryogenic concrete using acoustic emission sensors and permeability testing

    Kogbara, Reginald B.; Parsaei, Boback; Iyengar, Srinath R.; Grasley, Zachary C.; Masad, Eyad A.; Zollinger, Dan G.

    2014-04-01

    This study evaluates the damage potential of concrete of different mix designs subjected to cryogenic temperatures, using acoustic emission (AE) and permeability testing. The aim is to investigate design methodologies that might be employed to produce concrete that resists damage when cooled to cryogenic temperatures. Such concrete would be suitable for primary containment of liquefied natural gas (LNG) and could replace currently used 9% Ni steel, thereby leading to huge cost savings. In the experiments described, concrete cubes, 150 mm x 150 mm x 150 mm, were cast using four different mix designs. The four mixes employed siliceous river sand as fine aggregate. Moreover, limestone, sandstone, trap rock and lightweight aggregate were individually used as coarse aggregates in the mixes. The concrete samples were then cooled from room temperature (20°C) to cryogenic temperature (-165°C) in a temperature chamber. AE sensors were placed on the concrete cubes during the cryogenic freezing process. The damage potential was evaluated in terms of the growth of damage as determined from AE, as a function of temperature and concrete mixture design. The damage potential observed was validated with water permeability testing. Initial results demonstrate the effects of the coefficient of thermal expansion (CTE) of the aggregates on damage growth. Concrete damage (cracking) resistance generally decreased with increasing coarse aggregate CTE, and was in the order, limestone ≥ trap rock concrete due to differential CTE of its components.

  16. Comparison of vibro-acoustic stimulation and acupressure effects in nonstress test results and its parameters in pregnant women

    Mahboubeh, Valiani; Masoumeh, Pirhadi; Zahra, Shahshahan

    2013-01-01

    Background: The primary goal of antenatal testing is to identify fetuses at risk of intrauterine neurologic injury or death so that these adverse outcomes can be prevented. We want to assess nonstress test (NST) results and some parameters before and after vibro-acoustic stimulation and acupressure. We did a randomized controlled clinical trial in Shahid-Beheshti Hospital in Isfahan in 2011. Materials and Methods: A total of 64 pregnant women (32-36 weeks) in prenatal care unit were selected ...

  17. A cosmic speed-trap: a gravity-independent test of cosmic acceleration using baryon acoustic oscillations

    Sutherland, Will

    2011-01-01

    We propose a new and highly model-independent test of cosmic acceleration by comparing observations of the baryon acoustic oscillation (BAO) scale at low and intermediate redshifts: we derive a new inequality relating BAO observables at two distinct redshifts, which must be satisfied for any reasonable homogeneous non-accelerating model, but is violated by models similar to LambdaCDM, due to acceleration in the recent past. This test is fully independent of the theory of gravity (GR or otherw...

  18. Study and Application of Acoustic Emission Testing in Fault Diagnosis of Low-Speed Heavy-Duty Gears

    Peng Chen

    2011-01-01

    Full Text Available Most present studies on the acoustic emission signals of rotating machinery are experiment-oriented, while few of them involve on-spot applications. In this study, a method of redundant second generation wavelet transform based on the principle of interpolated subdivision was developed. With this method, subdivision was not needed during the decomposition. The lengths of approximation signals and detail signals were the same as those of original ones, so the data volume was twice that of original signals; besides, the data redundancy characteristic also guaranteed the excellent analysis effect of the method. The analysis of the acoustic emission data from the faults of on-spot low-speed heavy-duty gears validated the redundant second generation wavelet transform in the processing and denoising of acoustic emission signals. Furthermore, the analysis illustrated that the acoustic emission testing could be used in the fault diagnosis of on-spot low-speed heavy-duty gears and could be a significant supplement to vibration testing diagnosis.

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

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

    2010-01-01

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

  20. Application of fiber grating-based acoustic sensor in progressive failure testing of e-glass/vinylester curve composites

    Azmi, Asrul Izam; Raju, Raju; Peng, Gang-Ding

    2012-02-01

    This paper reports an application of phase shifted fiber Bragg grating (PS-FBG) intensity-type acoustic sensor in a continuous and in-situ failure testing of an E-glass/vinylester top hat stiffener (THS). The narrow transmission channel of the PS-FBG is highly sensitive to small perturbation, hence suitable to be used in an effective acoustic emission (AE) assessment technique. The progressive failure of THS was tested under transverse loading to experimentally simulate the actual loading in practice. Our experimental tests have demonstrated, in good agreement with the commercial piezoelectric sensors, that the important failures information of the THS was successfully recorded by the simple intensity-type PS-FBG sensor.

  1. Spatial Hedonic Pricing Models for Testing the Adequacy of Acoustic Areas in Madrid, Spain

    José-María Montero

    2011-01-01

    Full Text Available Road traffic noise is one of the main concerns of large cities. Most of them have classified their territory in acoustic areas and have constructed strategic noise maps. From both sources we have elaborated seven types of acoustic neighbourhoods according to both their noise gap in regard to the legal standard and the percentage of population exposed to noise. A spatial Durbin model has been selected as the strategy that best models the impact of noise on housing prices. However, results for Madrid do not confirm the hedonic theory and indicate, as one of the possibilities, that the official acoustic areas in Madrid could be incorrectly designed.

  2. Characterization of Pump-Induced Acoustics in Space Launch System Main Propulsion System Liquid Hydrogen Feedline Using Airflow Test Data

    Eberhart, C. J.; Snellgrove, L. M.; Zoladz, T. F.

    2015-01-01

    High intensity acoustic edgetones located upstream of the RS-25 Low Pressure Fuel Turbo Pump (LPFTP) were previously observed during Space Launch System (STS) airflow testing of a model Main Propulsion System (MPS) liquid hydrogen (LH2) feedline mated to a modified LPFTP. MPS hardware has been adapted to mitigate the problematic edgetones as part of the Space Launch System (SLS) program. A follow-on airflow test campaign has subjected the adapted hardware to tests mimicking STS-era airflow conditions, and this manuscript describes acoustic environment identification and characterization born from the latest test results. Fluid dynamics responsible for driving discrete excitations were well reproduced using legacy hardware. The modified design was found insensitive to high intensity edgetone-like discretes over the bandwidth of interest to SLS MPS unsteady environments. Rather, the natural acoustics of the test article were observed to respond in a narrowband-random/mixed discrete manner to broadband noise thought generated by the flow field. The intensity of these responses were several orders of magnitude reduced from those driven by edgetones.

  3. Electromagnetic Acoustic Test of the Artificial Defects for a Plate-type Nuclear Fuel

    Most research and test reactors use the nuclear fuel plates which are consisted of a fuel meat in aluminum alloy. Last year, KAERI signed a deal with the Jordan Atomic Energy Commission to build the research reactor and have to supply the plate-type nuclear fuels. For the demands of world market, KAERI started the research and development of the plate-type fuel elements and endeavored to achieve a localization of the plate-type fuel fabrication. For the inspection of plate-type fuel elements to be used in Research Reactors, an immersion pulse-echo ultrasonic technique was applied. This inspection was done under immersion condition, so a nuclear fuel was immersed to be prone to corrosion and needed to have time and cost due to an additional process. The sample that will be examined is a non-ferromagnetic material such as aluminum with a good acousto-elastic property, which requires an effective inspection of a bond quality for a nuclear fuel under a manufacturing environment. The purpose of this study is to investigate the feasibility of an Electromagnetic Acoustic Transducer (EMAT) technology for an automated inspection of a nuclear fuel without water

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

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

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

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

    2011-01-21

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

  6. A methodology to condition distorted acoustic emission signals to identify fracture timing from human cadaver spine impact tests.

    Arun, Mike W J; Yoganandan, Narayan; Stemper, Brian D; Pintar, Frank A

    2014-12-01

    While studies have used acoustic sensors to determine fracture initiation time in biomechanical studies, a systematic procedure is not established to process acoustic signals. The objective of the study was to develop a methodology to condition distorted acoustic emission data using signal processing techniques to identify fracture initiation time. The methodology was developed from testing a human cadaver lumbar spine column. Acoustic sensors were glued to all vertebrae, high-rate impact loading was applied, load-time histories were recorded (load cell), and fracture was documented using CT. Compression fracture occurred to L1 while other vertebrae were intact. FFT of raw voltage-time traces were used to determine an optimum frequency range associated with high decibel levels. Signals were bandpass filtered in this range. Bursting pattern was found in the fractured vertebra while signals from other vertebrae were silent. Bursting time was associated with time of fracture initiation. Force at fracture was determined using this time and force-time data. The methodology is independent of selecting parameters a priori such as fixing a voltage level(s), bandpass frequency and/or using force-time signal, and allows determination of force based on time identified during signal processing. The methodology can be used for different body regions in cadaver experiments. PMID:25241279

  7. Nondestructive testing: use of IR and acoustics methods in buildings pathology

    Esposti, Walter; Meroni, Italo

    1995-03-01

    In the paper the authors present some experiences made using IR and acoustics methods in a non destructive way for the evaluation of situations of degradation in building materials and components. Two studies are presented: (1) detection of the delamination of wall renderings, especially those supporting frescos, by means of IR and sonic investigation; (2) use of infrared thermography for the visualization of fracture zones of walls and steel components under cyclic loads. The possibility of detecting rendering delaminations is based on the different path of the heat diffusion in part of the wall affected by the delamination, compared to the rest of the wall. The difference is caused by the presence of small pockets containing still air. The case study showed makes reference to the analysis of adhesion conditions of a rendering dating back to the IV century, applied on the bell towers of the ancient basilica dedicated to S. Lorenzo in Milan, Italy. The use of infrared thermography for detecting the strength status of materials and components is based on the fact that the strength status of parts of building components can become evident because of heat losses which appear where the component is weaker. The IR observation was made on steel bars subject to traction testing and on lightweight concrete prismatic samples subject to compression testing. The experiences indicate that there is room for this NdT technique to provide some useful answers. Nevertheless it is sure that more experimental work is needed in order to increase the full comprehension of the phenomena which are the basis of their applications for alternative uses.

  8. Comparison between sensitivities of quality control methods using ultrasonic waves, radiography and acoustic emission for the thick welded joint testing

    The testing of the thick welded joints of the nuclear industry is carried out by radiography and ultrasonics on completion of welding. When a fault is found, its repair requires a sometimes deep cut down to the position of the fault, then filling in of the cut by hand welding with a coated electrode. This very costly operation also involves the risk of causing new defects when building up by hand. Listening to the acoustic emission during the welding has been considered in order to seek the possibility of detecting defects when they appear, or soon after. The industrial use of this method would make an instant repair of the defective areas possible at less cost and with greater reliability. The study presented concerns the comparison between the results of the various non-destructive testing methods: radiography, ultrasonics and acoustic emission, for a thick welded joint in which the defects have been brought about

  9. Responsive acoustic surfaces

    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....

  10. Deep Bleeder Acoustic Coagulation (DBAC)—part II: in vivo testing of a research prototype system

    Sekins, K. Michael; Barnes, Stephen R.; Fan, Liexiang; Hopple, Jerry D.; Hsu, Stephen J.; Kook, John; Lee, Chi-Yin; Maleke, Caroline; Zeng, Xiaozheng; Moreau-Gobard, Romain; Ahiekpor-Dravi, Alexis; Funka-Lea, Gareth; Eaton, John; Wong, Keith; Keneman, Scott

    2015-01-01

    Background Deep Bleeder Acoustic Coagulation (DBAC) is an ultrasound image-guided high-intensity focused ultrasound (HIFU) method proposed to automatically detect and localize (D&L) and treat deep, bleeding, combat wounds in the limbs of soldiers. A prototype DBAC system consisting of an applicator and control unit was developed for testing on animals. To enhance control, and thus safety, of the ultimate human DBAC autonomous product system, a thermal coagulation strategy that minimized cavit...

  11. Final developments, validation and technology transfer for AE (acoustic emission) and SAFT-UT (Synthetic Aperture Focusing of Ultrasonic Testing)

    The program for validation and technology transfer for acoustic emission (AE) and Synthetic Aperture Focusing of Ultrasonic Testing (SAFT-UT) is designed to accomplish the final step of moving research results into beneficial application. Accomplishments for FY88 in the areas of AE and SAFT-UT data under this program are discussed in this paper. the information is treated under the topics of code activities, field validation, and seminars. Projected FY89 activities will continue to focus on these three areas

  12. Acoustic emission

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

  13. High intensity acoustic testing to determine structural fatigue life and to improve reliability in nuclear reactor and aerospace structures

    The author reviews some of the techniques in which high intensity acoustic testing is used in engineering practice. (a) In the nuclear engineering field the simulation of reactor noise due to the CO2 circulator and the use of strain gauges to obtain a response spectrum in order to predict the fatigue life of gas-cooled nuclear reactor structures where a 30 year lifespan is of paramount importance is described. (b) In the satellite field the simulation of the high intensity noise due to the launching rocket motors and the testing of the integrity of the satellite structure and the behaviour of the electronic control system when affected by high intensity acoustic excitation is discussed. The use of acoustic testing to improve the reliability before the launching of the satellite is also considered. (c) In the aircraft and rocket field the generation of high intensity noise to simulate boundary layer pressure fluctuation or turbulence of a flying object or aircraft at various speeds is considered. (Auth.)

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

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

    2014-01-01

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

  15. Quantitative Measures of Anthropogenic Noise on Harbor Porpoises: Testing the Reliability of Acoustic Tag Recordings

    Wisniewska, Danuta Maria; Teilmann, Jonas; Hermannsen, Line;

    2016-01-01

    In recent years, several sound and movement recording tags have been developed to sample the acoustic fi eld experienced by cetaceans and their reactions to it. However, little is known about how tag placement and an animal’s orientation in the sound fi eld affect the reliability of on-animal rec......In recent years, several sound and movement recording tags have been developed to sample the acoustic fi eld experienced by cetaceans and their reactions to it. However, little is known about how tag placement and an animal’s orientation in the sound fi eld affect the reliability of on...

  16. Quantitative Measures of Anthropogenic Noise on Harbor Porpoises: Testing the Reliability of Acoustic Tag Recordings.

    Wisniewska, Danuta M; Teilmann, Jonas; Hermannsen, Line; Johnson, Mark; Miller, Lee A; Siebert, Ursula; Madsen, Peter Teglberg

    2016-01-01

    In recent years, several sound and movement recording tags have been developed to sample the acoustic field experienced by cetaceans and their reactions to it. However, little is known about how tag placement and an animal's orientation in the sound field affect the reliability of on-animal recordings as proxies for actual exposure. Here, we quantify sound exposure levels recorded with a DTAG-3 tag on a captive harbor porpoise exposed to vessel noise in a controlled acoustic environment. Results show that flow noise is limiting onboard noise recordings, whereas no evidence of body shading has been found for frequencies of 2-20 kHz. PMID:26611092

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

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

    2009-01-01

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

  18. 3D acoustic imaging applied to the Baikal neutrino telescope

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

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

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

    2009-04-11

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

  20. SIMONA: A multi-purpose acoustic data simulator for development and testing of sonar signal processing

    Robert, M.K.; Groen, J.; Konijnendijk, N.J.

    2005-01-01

    The development of undersea defence technologies such as sonar relies heavily on the availability of high quality acoustic data. However, data acquisition is particularly expensive as sea trials involve experienced manpower and costly high-tech equipment. Also, at sea, the environment remains unpred

  1. Screw-Machine Set-Up Operator, Jobbing (mach. shop) 604.380-028--Technical Report on Development of USTES Aptitude Test Battery.

    Manpower Administration (DOL), Washington, DC. U.S. Training and Employment Service.

    The United States Training and Employment Service General Aptitude Test Battery (GATB), first published in 1947, has been included in a continuing program of research to validate the tests against success in many different occupations. The GATB consists of 12 tests which measure nine aptitudes: General Learning Ability; Verbal Aptitude; Numerical…

  2. A Multi-Channel Setup to Study Fractures in Scintillators

    Tantot, A; Briche, R; Lefèvre, G; Manier, B; Zaïm, N; Deschanel, S; Vanel, L; Di Stefano, P C F

    2016-01-01

    To investigate fractoluminescence in scintillating crystals used for particle detection, we have developed a multi-channel setup built around samples of double-cleavage drilled compression (DCDC) geometry in a controllable atmosphere. The setup allows the continuous digitization over hours of various parameters, including the applied load, and the compressive strain of the sample, as well as the acoustic emission. Emitted visible light is recorded with nanosecond resolution, and crack propagation is monitored using infrared lighting and camera. An example of application to Bi4Ge3O12 (BGO) is provided.

  3. AMELIA CESTOL Test: Acoustic Characteristics of Circulation Control Wing with Leading- and Trailing-Edge Slot Blowing

    Horne, William C.; Burnside, Nathan J.

    2013-01-01

    The AMELIA Cruise-Efficient Short Take-off and Landing (CESTOL) configuration concept was developed to meet future requirements of reduced field length, noise, and fuel burn by researchers at Cal Poly, San Luis Obispo and Georgia Tech Research Institute under sponsorship by the NASA Fundamental Aeronautics Program (FAP), Subsonic Fixed Wing Project. The novel configuration includes leading- and trailing-edge circulation control wing (CCW), over-wing podded turbine propulsion simulation (TPS). Extensive aerodynamic measurements of forces, surfaces pressures, and wing surface skin friction measurements were recently measured over a wide range of test conditions in the Arnold Engineering Development Center(AEDC) National Full-Scale Aerodynamics Complex (NFAC) 40- by 80-Ft Wind Tunnel. Acoustic measurements of the model were also acquired for each configuration with 7 fixed microphones on a line under the left wing, and with a 48-element, 40-inch diameter phased microphone array under the right wing. This presentation will discuss acoustic characteristics of the CCW system for a variety of tunnel speeds (0 to 120 kts), model configurations (leading edge(LE) and/or trailing-edge(TE) slot blowing, and orientations (incidence and yaw) based on acoustic measurements acquired concurrently with the aerodynamic measurements. The flow coefficient, Cmu= mVSLOT/qSW varied from 0 to 0.88 at 40 kts, and from 0 to 0.15 at 120 kts. Here m is the slot mass flow rate, VSLOT is the slot exit velocity, q is dynamic pressure, and SW is wing surface area. Directivities at selected 1/3 octave bands will be compared with comparable measurements of a 2-D wing at GTRI, as will as microphone array near-field measurements of the right wing at maximum flow rate. The presentation will include discussion of acoustic sensor calibrations as well as characterization of the wind tunnel background noise environment.

  4. Acoustic Noise Test Report for the U.S. Department of Energy 1.5-Megawatt Wind Turbine

    Roadman, Jason [National Renewable Energy Lab. (NREL), Golden, CO (United States); Huskey, Arlinda [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-07-01

    A series of tests were conducted to characterize the baseline properties and performance of the U.S. Department of Energy (DOE) 1.5-megawatt wind turbine (DOE 1.5) to enable research model development and quantify the effects of future turbine research modifications. The DOE 1.5 is built on the platform of GE's 1.5-MW SLE commercial wind turbine model. It was installed in a nonstandard configuration at the NWTC with the objective of supporting DOE Wind Program research initiatives such as A2e. Therefore, the test results may not represent the performance capabilities of other GE 1.5-MW SLE turbines. The acoustic noise test documented in this report is one of a series of tests carried out to establish a performance baseline for the DOE 1.5 in the NWTC inflow environment.

  5. Scale Model Acoustic Test Validation of IOP-SS Water Prediction using Loci-STREAM-VoF

    Nielsen, Tanner; West, Jeff

    2015-01-01

    The Scale Model Acoustic Test (SMAT) is a 5% scale test of the Space Launch System (SLS), which is currently being designed at Marshall Space Flight Center (MSFC). SMAT consists of a 5% scale representation of the ignition overpressure sound-suppression system (IOP-SS) that is being tested to quantify the water flow and induced air entrainment in and around the mobile launcher exhaust hole. This data will be compared with computational fluid dynamics (CFD) simulations using the newly developed Loci-STREAM Volume of Fluid (VoF) methods. Compressible and incompressible VoF methods have been formulated, and are currently being used to simulate the water flow of SMAT IOP-SS. The test data will be used to qualitatively and quantitatively assess and validate the VoF methods.

  6. From design to flight testing : overview of rotorcraft acoustic research at onera for industrial applications.

    Delrieux, Y.

    2014-01-01

    The reduction of noise emission has become a key commercial argument for helicopter manufacturers, such as Airbus Helicopters. For years, Airbus helicopters has placed emphasis on the good acoustic behavior of its helicopters, as proven by its communication on the fenestron concept, the acceptance of its aircraft for the Grand Canyon tours and the presentation of its recent Bluecopter™ Technology. Thus, Airbus helicopters has become one of leaders in the manufacture of low noise helicopters.S...

  7. Optimising Baryon Acoustic Oscillation Surveys - I: Testing the concordance LCDM cosmology

    Parkinson, David; Blake, Chris; Kunz, Martin; Bassett, Bruce A.; Nichol, Robert C.; Glazebrook, Karl

    2007-01-01

    We optimize the design of future spectroscopic redshift surveys for constraining the dark energy via precision measurements of the baryon acoustic oscillations (BAO), with particular emphasis on the design of the Wide-Field Multi-Object Spectrograph (WFMOS). We develop a model that predicts the number density of possible target galaxies as a function of exposure time and redshift. We use this number counts model together with fitting formulae for the accuracy of the BAO measurements to determ...

  8. Testing and verification of a scale-model acoustic propagation system.

    Sagers, Jason D; Ballard, Megan S

    2015-12-01

    This paper discusses the design and operation of a measurement apparatus used to conduct scale-model underwater acoustic propagation experiments, presents experimental results for an idealized waveguide, and compares the measured results to data generated by two-dimensional (2D) and three-dimensional (3D) numerical models. The main objective of this paper is to demonstrate the capability of the apparatus for a simple waveguide that primarily exhibits 2D acoustic propagation. The apparatus contains a computer-controlled positioning system that accurately moves a receiving transducer in the water layer above a scale-model bathymetry while a stationary source transducer emits broadband pulsed waveforms. Experimental results are shown for a 2.133 m × 1.219 m bathymetric part possessing a flat-bottom bathymetry with a translationally invariant wedge of 10° slope along one edge. Beamformed results from a synthetic horizontal line array indicate the presence of strong in-plane arrivals along with weaker diffracted and horizontally refracted arrivals. A simulated annealing inversion method is applied to infer values for five waveguide parameters with the largest measurement uncertainty. The inferred values are then used in a 2D method of images model and a 3D adiabatic normal-mode model to simulate the measured acoustic data. PMID:26723314

  9. Testing Thermo-acoustic Sound Generation in Water with Proton and Laser Beams

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

    2005-01-01

    Experiments were performed at a proton accelerator and an infrared laser acility to investigate the sound generation caused by the energy deposition of pulsed particle and laser beams in water. The beams with an energy range of 1 PeV to 400 PeV per proton beam spill and up to 10 EeV for the laser pulse were dumped into a water volume and the resulting acoustic signals were recorded with pressure sensitive sensors. Measurements were performed at varying pulse energies, sensor positions, beam diameters and temperatures. The data is well described by simulations based on the thermo-acoustic model. This implies that the primary mechanism for sound generation by the energy deposition of particles propagating in water is the local heating of the media giving rise to an expansion or contraction of the medium resulting in a pressure pulse with bipolar shape. A possible application of this effect would be the acoustical detection of neutrinos with energies greater than 1 EeV.

  10. AST Launch Vehicle Acoustics

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

    2015-01-01

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

  11. PVDF-based acoustic sensors prototype for the study of the thermoacoustic model

    To measure the ultra-hight energy neutrino flux, studies on a larger IceCube neutrino observatory at the south pole have been intensively investigated in the last years. These studies have introduced a hybrid detection concept including radio and acoustic detection in addition to existing optical detection. The South Pole Acoustic Test Setup (SPATS) was built and deployed to evaluate the acoustic properties of the South Pole ice for the purpose of assessing the feasibility of an acoustic neutrino detection array. The Aachen Acoustic Laboratory (AAL) is supporting these efforts and providing infrastructures for the calibration of PZT-based acoustic sensors used in SPATS, study of a laser-based thermoacoustic model under laboratory conditions and investigating new piezoelectric materials for use in a next generation of acoustic sensors. In this talk we present the R and D status and first results of an acoustic sensor prototype based on PVDF material (Polyvinylidene Fluoride). With a flat frequency response and sensitivity the PVDF response to a thermoacoustic signal has shown the expected bipolar signal free of any superimposed resonances. The analysis of such a clean bipolar signal allow a deeper insight into understanding the thermoacoustic model and leading to a further development of optimized acoustic sensors for deployment at the South Pole.

  12. Design and setup of a testing device to investigate a reduced sized attachment system mock up for the ITER EU HCPB-TBM under different mechanical loading conditions

    Highlights: • A measurement system is developed to measure the electro-magnetic forces acting on the ITER EU HCPB TBM during operation. • A system based on the measurement of strain signals in combination with two force reconstruction methods is proposed. • Two mock ups have been designed to test and calibrate the measurement system. • A suitable testing device has been built to test the measuring system. • First results with simulated strain data are presented. - Abstract: In order to determine the forces acting on the EU-Helium Cooled Pebble Bed Test Blanket Module (HCPB-TBM) during operation, a measurement system is developed. Therefore, two force reconstruction (FR) methods using measured strain signals are selected that are suitable for the application to the TBM. The first one, the augmented Kalman filter is a combined deterministic-stochastic approach. A second FR method based on the concept of a model predictive controller is proposed in this paper, which uses an optimization algorithm. In order to test the selected methods a testing device has been built which can be used to apply different force excitations on a reduced sized TBM mock up and measure the resulting strain signals of 16 strain gages. A simple tube mock up has been designed and manufactured to test and calibrate the FR algorithms. In addition, a second TBM mock up with attachment system is described. Finally, first results of the FR of a worst-case test case from simulated strain data of the simple tube mock up are presented

  13. External quality assessment for KRAS testing is needed: setup of a European program and report of the first joined regional quality assessment rounds

    Bellon, Ellen; Ligtenberg, Marjolijn J L; Tejpar, Sabine; Cox, Karen; de Hertogh, Gert; de Stricker, Karin; Edsjö, Anders; Gorgoulis, Vassilis; Höfler, Gerald; Jung, Andreas; Kotsinas, Athanassios; Laurent-Puig, Pierre; López-Ríos, Fernando; Hansen, Tine Plato; Rouleau, Etienne; Vandenberghe, Peter; van Krieken, Johan J M; Dequeker, Elisabeth

    2011-01-01

    . In an effort to ensure optimal, uniform, and reliable community-based KRAS testing throughout Europe, a KRAS external quality assessment (EQA) scheme was set up. The first large assessment round included 59 laboratories from eight different European countries. For each country, one regional scheme...... further expand this program to more laboratories to provide a robust estimate of the quality of KRAS testing in Europe, and provide the basis for remedial measures and harmonization....

  14. Acoustic emission for on-line reactor monitoring: results of intermediate vessel test monitoring and reactor hot functional

    The objective of the acoustic emission (AE)/flaw characterization program presented is to develop use of the AE method on a continuous basis during operation and during hydrotest, to detect and analyze flow growth in reactor pressure vessels and primary piping. The program scope is described by three primary areas of effort: develop a method to identify crack growth AE signals; develop a relationship between measured AE and crack growth; demonstrate the total concept through off-reactor vessel tests; and, on-reactor monitoring. The laboratory speciments used to determine fundamental feasibility of program objectives were ASTM A533 B, Class 1 steel. The ZB-1 vessel test is described, and the results are presented. Reactor hot functional testing was done on the Watts Bar Unit 1. Evidence shows that AE from cracking in inaccessible parts of the reactor system such as the vessel beltline should be detectable

  15. 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

    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)

  16. Acoustic testing of welded joints of steam pipelines with the cast stub tube of a slide valve

    Specific task has been made, i.e. to determine whether it is possible to conduct reliable inspection of a welded joint in a rolled pipe made of 12Kh1MF steel 18-22 mm thick with a cast branch piece of the lock gate made of 20KhMFL steel 27-40 mm thick, its outer diameter being 290 mm. The lock gate is intended for service under a pressure of 9.8 MPa and temperature of the working fluid 540 deg C. It is shown that acoustic testing of welded joints in the power engineering equipment with cast elements is possible with a sensitivity corresponding to the flat-bottom reflector area of at least 7 mm2, and minimal noise resistance of 2 dB in case of non-optimal angle of the butt end boring on the joint inner surface. Methodological recommendations on acoustic testing of the above-mentioned joints are made

  17. Damping seal verification setup

    Cappel, K. L.

    1985-01-01

    The heart of the Space Shuttle Main Engine (SSME) is a set of turbopumps that propel cryogenic fluids at very high pressures and flow rates, at rotor speeds up to 37,000 rpm. Bushing seals that cause the flow in the fluid film to become turbulent, by means of a multiplicity of pockets, were shown theoretically not only to inhibit subsynchronous whirl, but to reduce leakage as well. However, experimental data that relate these two desirable characteristics to such parameters as pocket depth, Reynolds number (based on clearance and axial flow rate), and rotating speed are limited. To obtain the required data, NASA's Marshall Space Flight Center (MSFC) commissioned Wyle Laboratories to design, build and operate a test rig in which the damping efficacy and leakage reduction of typical candidate seals are to be evaluated.

  18. Design Of Mechanical Test Setup To Find The Endurance Limit Of CoilCompression SpringUsing Modified Slider-Crank Mechanism

    Harshal Vispute

    2015-08-01

    Full Text Available Abstract- A spring is an elastic or resilient body whose function is to deflect or deform when a load is applied and recover its original shape when the load is removed. The important applications of springs are in application of a force clutches brakes etc. measurement of a force spring balance storing energy clocktoy springs and absorbing shocks and vibrations springs in vehicle suspension systems. Fatigue loads are generally cyclic and fluctuating in nature and are much less in magnitude than the yield strength of materials but they tend to have unpredictable behavior due to dissimilar and brutal fracture patterns. To avoid this determining the endurance limit becomes inevitability. The present paper aims to test the endurance limit of a wide range of coiledcompression springs in the smallest possible time frame using a screw-based modified slider-crank mechanism in a mechanical system.

  19. Deformation, acoustic emission and ultrasound velocity during fatigue tests on paper

    Hæggström E.

    2010-06-01

    Full Text Available We study the evolution of mechanical properties of paper samples during cyclic experiments. The issue is to look at the sample-to-sample variation, and we try to predict the number of loading cycles to failure. We used two concurrent methods to obtain the deformation: the strain was calculated from vertical displacement measured by laser interferometer sensor, as well as, computed by digital image correlation technique from pictures taken each 2s by a camera. Acoustic emission of fracture was also recorded, and an active ultrasonic wave method using piezoelectric transducers is used to follow the viscoelastic behaviour of each sample. We found that a sharp final increase of different variables like deformation, strain rate and fluctuations, are signs of an imminent rupture of the paper. Moreover looking at the evolution of these quantities during the first cycle only is already an indicator about the lifetime of the sample.

  20. Damage Characterization of Bio and Green Polyethylene–Birch Composites under Creep and Cyclic Testing with Multivariable Acoustic Emissions

    Alencar Bravo

    2015-11-01

    Full Text Available Despite the knowledge gained in recent years regarding the use of acoustic emissions (AEs in ecologically friendly, natural fiber-reinforced composites (including certain composites with bio-sourced matrices, there is still a knowledge gap in the understanding of the difference in damage behavior between green and biocomposites. Thus, this article investigates the behavior of two comparable green and biocomposites with tests that better reflect real-life applications, i.e., load-unloading and creep testing, to determine the evolution of the damage process. Comparing the mechanical results with the AE, it can be concluded that the addition of a coupling agent (CA markedly reduced the ratio of AE damage to mechanical damage. CA had an extremely beneficial effect on green composites because the Kaiser effect was dominant during cyclic testing. During the creep tests, the use of a CA also avoided the transition to new damaging phases in both composites. The long-term applications of PE green material must be chosen carefully because bio and green composites with similar properties exhibited different damage processes in tests such as cycling and creep that could not be previously understood using only monotonic testing.

  1. Analysis of acoustic-seismic coupling behaviour for CTBT on-site inspection performance improvement

    Liebsch, Mattes; Knoop, Jan-Frederik [Technische Univ. Dortmund (Germany)

    2013-07-01

    After teleseismic detection of a big underground explosion, during on-site inspections under the Comprehensive Nuclear Test-Ban Treaty (CTBT) weak seismic signals from aftershocks are to be detected. These, however, can be masked by soil vibrations which are caused by acoustic waves which couple to the ground. To analyse the coupling behaviour between acoustic waves and soil vibrations several experiments with different acoustic sources (helicopters, firecrackers, loudspeaker) were performed. Of special interest is the influence of surface waves, excited in a larger area around the sensor, which can superpose constructively at the position of the sensor and can increase the measured seismic signal. A better understanding of the acoustic-seismic coupling can be used to develop guidelines for seismic aftershock measurements, such as a suitable sensor setup, with the goal of reducing or even preventing disturbing signals to improve the performance of on-site inspections for the CTBT.

  2. Analysis of acoustic-seismic coupling behaviour for CTBT on-site inspection performance improvement

    After teleseismic detection of a big underground explosion, during on-site inspections under the Comprehensive Nuclear Test-Ban Treaty (CTBT) weak seismic signals from aftershocks are to be detected. These, however, can be masked by soil vibrations which are caused by acoustic waves which couple to the ground. To analyse the coupling behaviour between acoustic waves and soil vibrations several experiments with different acoustic sources (helicopters, firecrackers, loudspeaker) were performed. Of special interest is the influence of surface waves, excited in a larger area around the sensor, which can superpose constructively at the position of the sensor and can increase the measured seismic signal. A better understanding of the acoustic-seismic coupling can be used to develop guidelines for seismic aftershock measurements, such as a suitable sensor setup, with the goal of reducing or even preventing disturbing signals to improve the performance of on-site inspections for the CTBT.

  3. An initial test of an Intelligent Distributed Acoustic Sensing (iDAS) in the ice in Lake Mendota

    Castongia, E.; Fratta, D.; Wang, H. F.; Mondanos, M.; Chalari, A.

    2013-12-01

    A Distributed Acoustic Sensor (DAS) was deployed to assess wave propagation detection in ice using fiber-optic cable. The acoustic field is sensed continuously along an optical fiber cable by interrogating it with pulses of light. The Sensor (iDAS manufactured by Silixa) samples the coupled medium as to the fiber, as waves travel through the medium, at several kilohertz along every meter of the cable. In March 2012 measurements were carried out along a triangular shaped array on the frozen surface of Lake Mendota. The purpose of the test was to assess the applicability of DAS to determine near surface geophysical properties from its unique way of measuring acoustic fields. We constructed an equilateral triangle array with a side length of 30 meters by freezing optical fiber cables into the sub surface layer of the ice which ranged in thickness between 15 to 20 cm. The fiber cables were frozen to a depth of about 10 cm to achieve uniform cable-ice coupling. The cable sensor was continuous and was looped about 4 times around to get multiple readings at each sampling location, and resulted in a total cable length of about 445 meters. Two different cable constructions were tested. The first type was of tight-buffered central stainless steel capillary tube and the second type of steel-reinforced central stainless steel loose tube. Seismic shots were generated using a sledge hammer and steel plate. Various shot sequences were taken along three different directions to assess the response and sensitivity of the system. A vertical geophone array was also deployed for a reference measurement every 5 meters along each of the sides of the triangle. Every 10 meters, the vertical geophones were complemented by two horizontal geophones. Analysis of the data showed that wavefronts of first arrivals were clearly visible from even the furthest shot location which enabled calculations of properties of the ice as the wavefronts traveled through it. Differences in sign in the recorded

  4. Algorithmic Pseudorandomness in Quantum Setups

    Bendersky, Ariel; de la Torre, Gonzalo; Senno, Gabriel; Figueira, Santiago; Acín, Antonio

    2016-06-01

    Many experimental setups in quantum physics use pseudorandomness in places where the theory requires randomness. In this Letter we show that the use of pseudorandomness instead of proper randomness in quantum setups has potentially observable consequences. First, we present a new loophole for Bell-like experiments: if some of the parties choose their measurements pseudorandomly, then the computational resources of the local model have to be limited in order to have a proper observation of nonlocality. Second, we show that no amount of pseudorandomness is enough to produce a mixed state by computably choosing pure states from some basis.

  5. High-temperature metallography setup

    A high-temperature metallography setup is presented. In this setup the observation of processes such as that of copper recrystallization was made possible, and the structure of metals such as uranium could be revealed. A brief historical review of part of the research works that have been done with the help of high temperature metallographical observation technique since the beginning of this century is included. Detailed description of metallographical specimen preparation technique and theoretical criteria based on the rate of evaporation of materials present on the polished surface of the specimens are given

  6. The spectral imaging facility: Setup characterization

    The SPectral IMager (SPIM) facility is a laboratory visible infrared spectrometer developed to support space borne observations of rocky bodies of the solar system. Currently, this laboratory setup is used to support the DAWN mission, which is in its journey towards the asteroid 1-Ceres, and to support the 2018 Exo-Mars mission in the spectral investigation of the Martian subsurface. The main part of this setup is an imaging spectrometer that is a spare of the DAWN visible infrared spectrometer. The spectrometer has been assembled and calibrated at Selex ES and then installed in the facility developed at the INAF-IAPS laboratory in Rome. The goal of SPIM is to collect data to build spectral libraries for the interpretation of the space borne and in situ hyperspectral measurements of planetary materials. Given its very high spatial resolution combined with the imaging capability, this instrument can also help in the detailed study of minerals and rocks. In this paper, the instrument setup is first described, and then a series of test measurements, aimed to the characterization of the main subsystems, are reported. In particular, laboratory tests have been performed concerning (i) the radiation sources, (ii) the reference targets, and (iii) linearity of detector response; the instrumental imaging artifacts have also been investigated

  7. The spectral imaging facility: Setup characterization

    De Angelis, Simone; Ammannito, Eleonora; Di Iorio, Tatiana; De Sanctis, Maria Cristina; Manzari, Paola Olga; Liberati, Fabrizio; Tarchi, Fabio; Dami, Michele; Olivieri, Monica; Pompei, Carlo; Mugnuolo, Raffaele

    2015-09-01

    The SPectral IMager (SPIM) facility is a laboratory visible infrared spectrometer developed to support space borne observations of rocky bodies of the solar system. Currently, this laboratory setup is used to support the DAWN mission, which is in its journey towards the asteroid 1-Ceres, and to support the 2018 Exo-Mars mission in the spectral investigation of the Martian subsurface. The main part of this setup is an imaging spectrometer that is a spare of the DAWN visible infrared spectrometer. The spectrometer has been assembled and calibrated at Selex ES and then installed in the facility developed at the INAF-IAPS laboratory in Rome. The goal of SPIM is to collect data to build spectral libraries for the interpretation of the space borne and in situ hyperspectral measurements of planetary materials. Given its very high spatial resolution combined with the imaging capability, this instrument can also help in the detailed study of minerals and rocks. In this paper, the instrument setup is first described, and then a series of test measurements, aimed to the characterization of the main subsystems, are reported. In particular, laboratory tests have been performed concerning (i) the radiation sources, (ii) the reference targets, and (iii) linearity of detector response; the instrumental imaging artifacts have also been investigated.

  8. The spectral imaging facility: Setup characterization

    De Angelis, Simone, E-mail: simone.deangelis@iaps.inaf.it; De Sanctis, Maria Cristina; Manzari, Paola Olga [Institute for Space Astrophysics and Planetology, INAF-IAPS, Via Fosso del Cavaliere, 100, 00133 Rome (Italy); Ammannito, Eleonora [Institute for Space Astrophysics and Planetology, INAF-IAPS, Via Fosso del Cavaliere, 100, 00133 Rome (Italy); Department of Earth, Planetary and Space Sciences, University of California, Los Angeles, Los Angeles, California 90095-1567 (United States); Di Iorio, Tatiana [ENEA, UTMEA-TER, Rome (Italy); Liberati, Fabrizio [Opto Service SrL, Campagnano di Roma (RM) (Italy); Tarchi, Fabio; Dami, Michele; Olivieri, Monica; Pompei, Carlo [Selex ES, Campi Bisenzio (Italy); Mugnuolo, Raffaele [Italian Space Agency, ASI, Spatial Geodesy Center, Matera (Italy)

    2015-09-15

    The SPectral IMager (SPIM) facility is a laboratory visible infrared spectrometer developed to support space borne observations of rocky bodies of the solar system. Currently, this laboratory setup is used to support the DAWN mission, which is in its journey towards the asteroid 1-Ceres, and to support the 2018 Exo-Mars mission in the spectral investigation of the Martian subsurface. The main part of this setup is an imaging spectrometer that is a spare of the DAWN visible infrared spectrometer. The spectrometer has been assembled and calibrated at Selex ES and then installed in the facility developed at the INAF-IAPS laboratory in Rome. The goal of SPIM is to collect data to build spectral libraries for the interpretation of the space borne and in situ hyperspectral measurements of planetary materials. Given its very high spatial resolution combined with the imaging capability, this instrument can also help in the detailed study of minerals and rocks. In this paper, the instrument setup is first described, and then a series of test measurements, aimed to the characterization of the main subsystems, are reported. In particular, laboratory tests have been performed concerning (i) the radiation sources, (ii) the reference targets, and (iii) linearity of detector response; the instrumental imaging artifacts have also been investigated.

  9. Study of quantitative assessment standard for Type 1 and Type 2 Gas cylinder using acoustic emission testing

    Acoustic emission testing (AET) of cylinders is advantageous in that it can be directly conducted on cylinders installed in a car, without needing to dissemble them on a real-time basis. Therefore, users prefer AET over other nondestructive testing methods. Owing to these advantages of AET, it has been approved by the Department of Transportation of the U.S. as a safety evaluation method for pressure containers or as an alternative to the hydroproof testing method. This paper presents a study of the quantitative evaluation criteria for a container having ultrasonic testing defects and also for Type 1 and Type 2 gas cylinders, which are defective seamless pressure containers provided by NK, a manufacturer of pressure containers. For the Type 1 cylinder, the process from crack growth to leak was observed in a repetitive fatigue test using a 113 L container according to ASTM E 1419-02. Further, for the Type 2 cylinder, integrity was evaluated using a 119 L sound container and a container damaged by hydraulic pressure, by the slow-fill method according to ASTM E 2191-02. Based on the AET results of the Type 1 and Type 2 cylinders, quantitative evaluation criteria were established for a defective and non-defective container.

  10. Thermal Acoustic Fatigue Apparatus

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

  11. Fast X-ray tomography and acoustic emission study of damage in metals during continuous tensile tests

    Model AA-2124 matrix composites with two different reinforcement sizes were pulled with a strain rate of 10-5 using a dedicated tensile rig suitable for in situ tomography. Two main novelty aspects characterize the present study. First, tomography provides a new approach towards understanding the significance of AE signals, recorded simultaneously, during image acquisition on the same sample. The number of acoustic emission events is found to be in good agreement with the number of cracks as detected by image analysis and the energy of the signals is proportional to the dimension of the cracks. Secondly, fast tomography was used to perform the first continuous in situ tensile test. The continuous procedure is compared in the paper with the standard step by step procedure

  12. Test of a virtual cylindrical acoustic resonator for determining the Boltzmann constant

    Feng, X. J.; Lin, H.; Gillis, K. A.; Moldover, M. R.; Zhang, J. T.

    2015-10-01

    We report progress toward determining the Boltzmann constant kB using the concept of a virtual acoustic resonator, a hypothetical resonator that is mathematically equivalent to a cylindrical cavity with periodic boundary conditions. We derived the virtual resonator by combining the measured frequencies of the longitudinal acoustic modes of two argon-filled, cylindrical cavity resonators in such a way to minimize the effects of the cavities’ ends, including transducers and ducts attached to the ends. The cavities had lengths of 80 mm and 160 mm and were operated in their longitudinal (ℓ,0,0) modes. We explored virtual resonators that combine modes of the two resonators that have nearly the same frequencies. The virtual resonator formed from the (2,0,0) mode of the 80 mm resonator combined with the (4,0,0) mode of the 160 mm resonator yielded a value for kB that is, fractionally, only (0.2  ±  1.5)  ×  10-6 larger than the 2010 CODATA-recommended value of kB. (The estimated uncertainty is one standard uncertainty corresponding to a 68% confidence level.) The same virtual resonator yielded values of the pressure derivatives of the speed of sound c in argon, (∂c2/∂p)T and (∂c2/∂p2)T, that differed from literature values by 1% and 2%, respectively. By comparison, when each cavity was considered separately, the values of kB, (∂c2/∂p)T, and (∂c2/∂p2)T differed from literature values by up to 7 ppm, 10%, and 5%, respectively. However, combining the results from the (3,0,0) or (4,0,0) modes of shorter resonator with the results from the (6,0,0) or (8,0,0) modes of the longer resonator yielded incorrect values of kB that varied from run-to-run. We speculate that these puzzling results originated in an unmodeled coupling, either between the two cavities (that resonated at nearly identical resonance frequencies in the same pressure vessel) or between the cavities and modes of the pressure vessel.

  13. Entanglement with restricted measurement setups

    Meznaric, Sebastian

    2010-01-01

    We consider what is the effective amount of entanglement when the measurement operators one has at their disposal are restricted. Such a scenario occurs when superselection rules are in effect or when there are imperfections in our measurement setup. Given a quantum state and the restrictions on measurements, we consider the following scenario. Imagine we have an ideal, or non-restricted, measurement setup and a state $\\rho_1$ and a non-ideal, or restricted, measurement setup and a state $\\rho_2$. Then the minimum amount of entanglement in $\\rho_1$ so that all quantum communication protocols still perform with the same fidelity as with $\\rho_2$ is effectively the entanglement with restricted measurement setup. For indistinguishable particles, we find that any quantum communication protocol that can be performed with indistinguishable particles, can thus be performed with a ``normal'' state of no more than $E_P$ of entanglement. For the imperfect measurement apparatus we find an upper bound for the effective e...

  14. Testing cosmic transparency with the latest baryon acoustic oscillations and type Ia supernovae data

    Jun Chen; Pu-Xun Wu; Hong-Wei Yu; Zheng-Xiang Li

    2013-01-01

    Observations show that Type Ia supernovae (SNe Ia) are dimmer than expected from a matter dominated Universe.It has been suggested that this observed phenomenon can also be explained using light absorption instead of dark energy.However,there is a serious degeneracy between the cosmic absorption parameter and the present matter density parameter Ωm when one tries to place constraints on the cosmic opacity using SNe Ia data.We combine the latest baryon acoustic oscillation (BAO) and Union2 SNe Ia data in order to break this degeneracy.Assuming a flat ACDM model,we find that,although an opaque Universe is favored by SNe Ia+BAO since the best fit value of the cosmic absorption parameter is larger than zero,Ωm =1 is ruled out at the 99.7% confidence level.Thus,cosmic opacity is not sufficient to account for the present observations and dark energy or modified gravity is still required.

  15. Measuring fast-temporal sediment fluxes with an analogue acoustic sensor: a wind tunnel study

    Poortinga, A.; Minnen, van, P.; Riksen, M.J.P.M.; Seeger, M.

    2010-01-01

    Research objective In this study, we test two passive traps (BEST sampler and MWAC sampler) and one acoustic device (saltiphone) in an aeolian sand wind tunnel to investigate how the experimental setup and the subsequent data processing affect the quantification of the aeolian sand flux. Type of research: Empirical research Method of data collection: Wind tunnel experiments Data comprises: - Wind velocity - Mass transport per height for different samplers - Analogue output of Saltiphone - Mas...

  16. Testing the effects of an acoustic harassment device on the behaviour of harbour porpoises (Phocoena Phocoena)

    Diederichs, Ansgar; Brandt, Miriam J.; Hoeschle, Caroline; Betke, Klaus; Nehls, Georg

    2011-07-01

    Full text: The use of monopile foundations for offshore wind farm construction goes along with considerable underwater noise emissions during pile driving, which can potentially harm marine mammals in the vicinity of the sound source. In order to avoid hearing damage in porpoises and seals the use of deterring devices is mandatory during pile driving in German waters. However, so far there is too little information to judge if the deterring effect is sufficient to prevent physical damage in these marine mammals. Using a combination of visual observations and passive acoustic monitoring (C-PODs) we investigated the spatial effects of a Lofitech seal scarer on harbour porpoises. The seal scarer emits pulses at 14 kHz at a source level of about 189dB re 1 muPa, and sound measurements at various distances where carried out. Sighting rates of porpoises significantly declined within the whole 1 km observation radius. Recordings of porpoise echolocation signals by C-PODs were significantly reduced out to a distance of 7 km, with the strongest effect at the nearest PODs and a weak effect at further distances. Minimum observed approach distance during 28 hours of seal scarer activity was 700 m. A response study revealed clear avoidance reactions by porpoises out to the maximum studied distance of 2.6 km. However, in some cases no reaction was found, and occasionally porpoises were also recorded by PODs at close distances. This shows that there may be substantial variation between individuals, different motivational states or different environmental conditions. These results show that the application of seal scarers is useful for reducing the number of harbour porpoises that may suffer hearing damage caused by pile driving. However, since complete exclusion of all animals cannot be achieved, alternative mitigation measures should be considered. (Author)

  17. Full-scale hot cell test of an acoustic sensor dedicated to measurement of the internal gas pressure and composition of a LWR nuclear fuel rod

    A full-scale hot cell test of the internal gas pressure and composition measurement by an acoustic sensor was carried out successfully between 2008 and 2010 on irradiated fuel rods in the LECA-STAR facility at Cadarache Centre. The acoustic sensor has been specially designed in order to provide a non-destructive technique to easily carry out the measurement of the internal gas pressure and gas composition (mainly Helium-Xenon mixture, with a small amount of Krypton) of a LWR nuclear fuel rod. This sensor has been achieved in 2007 and is now covered by an international patent. We performed the gas characterisation contained in irradiated fuel rods. The acoustic method accuracy is now 5 bars on the pressure measurement result and 0.3% on the evaluated gas composition. The results of the acoustic method were compared to puncture results (destructive sampling). Another significant conclusion is that the efficiency of the acoustic method is not altered by the irradiation time, and possible modification of the cladding properties. The sensor-operating characteristics have not been altered by a two-year exposure in the hot cell conditions. These results make it possible to demonstrate the feasibility of the technique on irradiated fuel rods. The transducer and the associated methodology are now operational. (authors)

  18. Extensions of cutting problems: setups

    Sebastian Henn

    2013-08-01

    Full Text Available Even though the body of literature in the area of cutting and packing is growing rapidly, research seems to focus on standard problems in the first place, while practical aspects are less frequently dealt with. This is particularly true for setup processes which arise in industrial cutting processes whenever a new cutting pattern is started (i.e. a pattern is different from its predecessor and the cutting equipment has to be prepared in order to meet the technological requirements of the new pattern. Setups involve the consumption of resources and the loss of production time capacity. Therefore, consequences of this kind must explicitly be taken into account for the planning and control of industrial cutting processes. This results in extensions to traditional models which will be reviewed here. We show how setups can be represented in such models, and we report on the algorithms which have been suggested for the determination of solutions of the respective models. We discuss the value of these approaches and finally point out potential directions of future research.

  19. Split Hopkinson Resonant Bar Test for Sonic-Frequency Acoustic Velocity and Attenuation Measurements of Small, Isotropic Geologic Samples

    Nakagawa, S.

    2011-04-01

    Mechanical properties (seismic velocities and attenuation) of geological materials are often frequency dependent, which necessitates measurements of the properties at frequencies relevant to a problem at hand. Conventional acoustic resonant bar tests allow measuring seismic properties of rocks and sediments at sonic frequencies (several kilohertz) that are close to the frequencies employed for geophysical exploration of oil and gas resources. However, the tests require a long, slender sample, which is often difficult to obtain from the deep subsurface or from weak and fractured geological formations. In this paper, an alternative measurement technique to conventional resonant bar tests is presented. This technique uses only a small, jacketed rock or sediment core sample mediating a pair of long, metal extension bars with attached seismic source and receiver - the same geometry as the split Hopkinson pressure bar test for large-strain, dynamic impact experiments. Because of the length and mass added to the sample, the resonance frequency of the entire system can be lowered significantly, compared to the sample alone. The experiment can be conducted under elevated confining pressures up to tens of MPa and temperatures above 100 C, and concurrently with x-ray CT imaging. The described Split Hopkinson Resonant Bar (SHRB) test is applied in two steps. First, extension and torsion-mode resonance frequencies and attenuation of the entire system are measured. Next, numerical inversions for the complex Young's and shear moduli of the sample are performed. One particularly important step is the correction of the inverted Young's moduli for the effect of sample-rod interfaces. Examples of the application are given for homogeneous, isotropic polymer samples and a natural rock sample.

  20. Basic test of acoustic emission sensor as a leak detector from pressure vessels and piping of nuclear power plant

    Basic tests of AE (Acoustic Emission) sensor that measures elastic wave of solid caused by leak of high pressure vessels, pipes or valves have been performed. The relation of leak flow rate and AE sensor's signal level, and the characteristics of AE signal attenuation vs. distance have been obtained experimentally as basic data. The test system consists of a pipe that can contain gas, water or steam whose maximum temperature is 275degC and maximum pressure is 6 MPa. A small scale crack is simulated by a small circular hole or a slit type rectangular shaped hole. It is observed that the AE signal level generated from leak part is proportional to the density of leaking fluid, to the fourth power of the velocity and to the cross sectional area of simulated crack. It is also observed that AE signal attenuation against distance on uniform cross section pipe is negligible small. This basic technology can be applied to detect leak from pressure vessels and piping in a nuclear power plant. (author)

  1. Acoustic Emission Monitoring of Compression-after-Impact Test of Nano-Particles-Coated CFRP Damaged by Simulated Lightning Strikes

    Nanoparticles-coated and impact-damaged carbon-fiber reinforced plastics(CFRP) laminates were tested under compression-after-impact(CAI) mode and the propagation of damage due to compressive loading has been monitored by acoustic emission(AE). The impact damage was induced not by mechanical loading but by a simulated lightning strike. CFRP laminates were made of carbon prepregs prepared by coating of conductive nano-particles directly on the fibers and the coupons were subjected to simulated lightning strikes with a high voltage/current impulse of 10∼40 kA within a few microseconds. The effects of nano-particles coating and the degree of damage induced by the simulated lightning strikes on the AE activities were examined, and the relationship between the compressive residual strength and AE behavior has been evaluated in terms of AE event counts and the onset of AE activity with the compressive loading. The degree of impact damage was also measured in terns of damage area by using ultrasonic C-scan images. From the results assessed during the CAI tests of damaged CFRP showed that AE monitoring appeared to be very useful to differentiate the degree of damage hence the mechanical integrity of composite structures damaged by lightning strikes

  2. Advanced Jet Noise Exhaust Concepts in NASA's N+2 Supersonics Validation Study and the Environmentally Responsible Aviation Project's Upcoming Hybrid Wing Body Acoustics Test

    Henderson, Brenda S.; Doty, Mike

    2012-01-01

    Acoustic and flow-field experiments were conducted on exhaust concepts for the next generation supersonic, commercial aircraft. The concepts were developed by Lockheed Martin (LM), Rolls-Royce Liberty Works (RRLW), and General Electric Global Research (GEGR) as part of an N+2 (next generation forward) aircraft system study initiated by the Supersonics Project in NASA s Fundamental Aeronautics Program. The experiments were conducted in the Aero-Acoustic Propulsion Laboratory at the NASA Glenn Research Center. The exhaust concepts presented here utilized lobed-mixers and ejectors. A powered third-stream was implemented to improve ejector acoustic performance. One concept was found to produce stagnant flow within the ejector and the other produced discrete-frequency tones (due to flow separations within the model) that degraded the acoustic performance of the exhaust concept. NASA's Environmentally Responsible Aviation (ERA) Project has been investigating a Hybrid Wing Body (HWB) aircraft as a possible configuration for meeting N+2 system level goals for noise, emissions, and fuel burn. A recently completed NRA led by Boeing Research and Technology resulted in a full-scale aircraft design and wind tunnel model. This model will be tested acoustically in NASA Langley's 14-by 22-Foot Subsonic Tunnel and will include dual jet engine simulators and broadband engine noise simulators as part of the test campaign. The objectives of the test are to characterize the system level noise, quantify the effects of shielding, and generate a valuable database for prediction method development. Further details of the test and various component preparations are described.

  3. USE OF SCALE MODELING FOR ARCHITECTURAL ACOUSTIC MEASUREMENTS

    ERÖZ, Ferhat

    2013-01-01

    In recent years, acoustic science and hearing has become important. Acoustic design used in tests of acoustic devices is crucial. Sound propagation is a complex subject, especially inside enclosed spaces. From the 19th century on, the acoustic measurements and tests were carried out using modeling techniques that are based on room acoustic measurement parameters.In this study, the effects of architectural acoustic design of modeling techniques and acoustic parameters were studied. In this con...

  4. Mechanisms of plastic instability and fracture of compressed and tensile tested Mg-Li alloys investigated using the acoustic emission method

    A. Pawełek; A. Piątkowski; W. Wajda; W. Skuza; A. Tarasek; W. Ozgowicz; B. Grzegorczyk; Z. Ranachowski; S. Kúdela; S. Kúdela, Jr.

    2016-01-01

    The results of the investigation of both mechanical and acoustic emission (AE) behaviors of Mg4Li5Al alloy subjected to compression and tensile tests at room temperature are compared with the test results obtained using the same alloy and loading scheme but at elevated temperatures. The main aim of the paper is to investigate, to determine and to explain the possible influence of factors related with enhanced internal stresses such as: segregation of precipitates along grain bound...

  5. Communication Acoustics

    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....

  6. Experimental Setup for Cyclic Lateral Loading of Monopiles in Sand

    Roesen, Hanne Ravn; Andersen, Lars Vabbersgaard; Ibsen, Lars Bo;

    2012-01-01

    influence of number of load cycles on the accumulated rotation of the monopile is investigated by means of a new 1g mechanical testing rig capable of providing more than 40,000 load cycles. The experimental setup is described and compared with previous small-scale tests and the result from one cyclic load...... test is evaluated....

  7. Characterization of textile electrodes and conductors using standardized measurement setups

    Textile electrodes and conductors are being developed and used in different monitoring scenarios, such as ECG or bioimpedance spectroscopy measurements. Compared to standard materials, conductive textile materials offer improved wearing comfort and enable long-term measurements. Unfortunately, the development and investigation of such materials often suffers from the non-reproducibility of the test scenarios. For example, the materials are generally tested on human skin which is difficult since the properties of human skin differ for each person and can change within hours. This study presents two test setups which offer reproducible measurement procedures for the systematic analysis of textile electrodes and conductors. The electrode test setup was designed with a special skin dummy which allows investigation of not only the electrical properties of textile electrodes but also the contact behavior between electrode and skin. Using both test setups, eight textile electrodes and five textile conductors were analyzed and compared

  8. Acoustic Neuroma

    An acoustic neuroma is a benign tumor that develops on the nerve that connects the ear to the brain. The tumor ... press against the brain, becoming life-threatening. Acoustic neuroma can be difficult to diagnose, because the symptoms ...

  9. Acoustic Neuroma

    An acoustic neuroma is a benign tumor that develops on the nerve that connects the ear to the brain. ... can press against the brain, becoming life-threatening. Acoustic neuroma can be difficult to diagnose, because the ...

  10. Damage Characterization of Glass/Epoxy Composite Under Three-Point Bending Test Using Acoustic Emission Technique

    Pashmforoush, Farzad; Fotouhi, Mohamad; Ahmadi, Mehdi

    2012-07-01

    Acoustic emission (AE) technique is an efficient non-destructive method for detection and identification of various damage mechanisms in composite materials. Discrimination of AE signals related to different damage modes is of great importance in the use of this technique. For this purpose, integration of k-means algorithm and genetic algorithm (GA) was used in this study to cluster AE events of glass/epoxy composite during three-point bending test. Performing clustering analysis, three clusters with separate frequency ranges were obtained, each one representing a distinct damage mechanism. Furthermore, time-frequency analysis of AE signals was performed based on wavelet packet transform (WPT). In order to find the dominant components associated with different damage mechanisms, the energy distribution criterion was used. The frequency ranges of the dominant components were then compared with k-means genetic algorithm (KGA) outputs. Finally, SEM observation was utilized to validate the results. The obtained results indicate good performance of the proposed methods in the damage characterization of composite materials.

  11. Use of 7Li(p,n) reaction as a neutron source in a PGNAA setup.

    Naqvi, A A; Nagadi, M M

    2005-03-01

    The performance of a 7Li(p,n) reaction-based Prompt Gamma Ray Neutron Activation Analysis (PGNAA) setup has been determined for analysis of Portland cement samples using Monte Carlo study. The calculations were carried out for a 7Li(p,n) reaction-based PGNAA setup with an external moderator similar to the one used in a previous 2.8 MeV neutrons-based PGNAA setup. The optimum values of geometry parameters of the 7Li(p,n) reaction-based setup are different from those of the 2.8 MeV neutrons-based setup resulting in better performance of the 7Li(p,n) reaction-based setup. The prompt gamma-ray yield from the 7Li(p,n) reaction-based setup is 60-70% higher than that from the 2.8 MeV neutrons-based setup. Although the performances of the 7Li(p,n) reaction-based setup is comparable with that of a previously studied 3H(p,n) reaction-based setup, yet performance of the 7Li(p,n) reaction-based setup is superior to that of the 3H(p,n) reaction-based setup because it has less radiation hazard due to utilization of non-radioactive neutron producing target. This study has provided a theoretical base for experimental test of a 7Li(p,n) reaction-based PGNAA setup. PMID:15607917

  12. Use of 7Li(p,n) reaction as a neutron source in a PGNAA setup

    The performance of a 7Li(p,n) reaction-based Prompt Gamma Ray Neutron Activation Analysis (PGNAA) setup has been determined for analysis of Portland cement samples using Monte Carlo study. The calculations were carried out for a 7Li(p,n) reaction-based PGNAA setup with an external moderator similar to the one used in a previous 2.8 MeV neutrons-based PGNAA setup. The optimum values of geometry parameters of the 7Li(p,n) reaction-based setup are different from those of the 2.8 MeV neutrons-based setup resulting in better performance of the 7Li(p,n) reaction-based setup. The prompt γ-ray yield from the 7Li(p,n) reaction-based setup is 60-70% higher than that from the 2.8 MeV neutrons-based setup. Although the performances of the 7Li(p,n) reaction-based setup is comparable with that of a previously studied 3H(p,n) reaction-based setup, yet performance of the 7Li(p,n) reaction-based setup is superior to that of the 3H(p,n) reaction-based setup because it has less radiation hazard due to utilization of non-radioactive neutron producing target. This study has provided a theoretical base for experimental test of a 7Li(p,n) reaction-based PGNAA setup

  13. An automated full-chip micro-piv setup for measuring microchannel acoustophoresis:

    Barnkob, Rune; Augustsson, P.; Laurell, T.;

    2011-01-01

    We present a novel μm-resolution particle-image velocimetry setup capable of automated full-chip measurements of microchannel acoustophoresis. Our system allows for fast collection of a sufficient amount of data enabling reliable determination of the influence from the forces from acoustic...

  14. Verification of nonlinear dynamic structural test results by combined image processing and acoustic analysis

    Tene, Yair; Tene, Noam; Tene, G.

    1993-08-01

    An interactive data fusion methodology of video, audio, and nonlinear structural dynamic analysis for potential application in forensic engineering is presented. The methodology was developed and successfully demonstrated in the analysis of heavy transportable bridge collapse during preparation for testing. Multiple bridge elements failures were identified after the collapse, including fracture, cracks and rupture of high performance structural materials. Videotape recording by hand held camcorder was the only source of information about the collapse sequence. The interactive data fusion methodology resulted in extracting relevant information form the videotape and from dynamic nonlinear structural analysis, leading to full account of the sequence of events during the bridge collapse.

  15. Topics in acoustics, non destructive testing, and thermo-mechanics of continua

    A small scale physical model of a granular porous medium was studied .Osmosis, filtration and fracture were considered, both experimentally and mathematically.Longitudinal ultrasonic pulse velocity was measured in slender timber and concrete bodies in order to characterized the geometric dispersion effects.A mathematical model is developed to described geometric dispersion in reinforced concrete.A sequential method for non destructive testing of structures by mechanicals vibrations is proposed and theoretically considered.Some simple examples are fully developed from a theoretical stand point

  16. Acoustic Tractor Beam

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

    2014-05-01

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

  17. Usage Autocorrelation Function in the Capacity of Indicator Shape of the Signal in Acoustic Emission Testing of Intricate Castings

    Popkov, Artem

    2016-01-01

    The article contains information about acoustic emission signals analysing using autocorrelation function. Operation factors were analysed, such as shape of signal, the origins time and carrier frequency. The purpose of work is estimating the validity of correlations methods analysing signals. Acoustic emission signal consist of different types of waves, which propagate on different trajectories in object of control. Acoustic emission signal is amplitude-, phase- and frequency-modeling signal. It was described by carrier frequency at a given point of time. Period of signal make up 12.5 microseconds and carrier frequency make up 80 kHz for analysing signal. Usage autocorrelation function like indicator the origin time of acoustic emission signal raises validity localization of emitters.

  18. Setup Analysis: Combining SMED with Other Tools

    Stadnicka Dorota

    2015-02-01

    Full Text Available The purpose of this paper is to propose the methodology for the setup analysis, which can be implemented mainly in small and medium enterprises which are not convinced to implement the setups development. The methodology was developed after the research which determined the problem. Companies still have difficulties with a long setup time. Many of them do nothing to decrease this time. A long setup is not a sufficient reason for companies to undertake any actions towards the setup time reduction. To encourage companies to implement SMED it is essential to make some analyses of changeovers in order to discover problems. The methodology proposed can really encourage the management to take a decision about the SMED implementation, and that was verified in a production company. The setup analysis methodology is made up of seven steps. Four of them concern a setups analysis in a chosen area of a company, such as a work stand which is a bottleneck with many setups. The goal is to convince the management to begin actions concerning the setups improvement. The last three steps are related to a certain setup and, there, the goal is to reduce a setup time and the risk of problems which can appear during the setup. In this paper, the tools such as SMED, Pareto analysis, statistical analysis, FMEA and other were used.

  19. Audience effects, but not environmental influences, explain variation in gorilla close distance vocalizations-A test of the acoustic adaptation hypothesis.

    Hedwig, Daniela; Mundry, Roger; Robbins, Martha M; Boesch, Christophe

    2015-12-01

    Close distance vocalizations are an integral part of primate vocal communication. They exhibit large acoustic variation which has been suggested to constitute flexible responses to the highly variable social setting of group living animals. However, a recent study suggested that acoustic variation in close distance calls of baboons may also arise from acoustic adaptations to environmental factors in order to counteract sound degradation. We tested whether the variation in calling rate and acoustic structure of gorilla close distance vocalizations may serve to counteract distorting effects of vegetation during sound propagation. Using focal animal sampling we recorded the vocal behavior of 15 adult individuals living in two groups: one group of western lowland gorillas Gorilla gorilla gorilla and one group of mountain gorillas Gorilla beringei beringei. We considered the distance between the caller and its nearest neighbor as the minimum transmission distance of calls; while vegetation density was quantified through measures of visibility. Our analysis revealed vocal plasticity in gorilla close calls in relation to changes in visibility and nearest neighbor distance. However, the observed changes in fundamental frequency and calling rate are unlikely to counteract degrading effects of vegetation, but rather seem to reflect reactions to variation in spatial and visual separation from other group members, similar to the audience effects demonstrated in a range of other species. We propose that vocal plasticity to counteract distorting environmental effects may not be prevalent across taxa and perhaps confined to species living in heterogeneous habitats with highly variable transmission conditions. PMID:26352614

  20. Feasibility of Electromagnetic Acoustic Evaluation for Quality Test of a Plate-type Nuclear Fuel

    Most research and test reactors use the nuclear fuel plates which are consisted of a fuel core in aluminum alloy. Recently KAERI signed a deal with the Jordan Atomic Energy Commission to build the research reactor and have to supply the plate-type nuclear fuels. For the demands of world market, KAERI started the research and development of the plate-type fuel elements and endeavored to achieve a localization of fuel fabrication. For the inspection of plate-type fuel elements to be used in Research Reactors, an immersion pulse-echo ultrasonic technique was applied. This inspection was done with water, so a nuclear fuel was immersed to be prone to corrosion and needed to have time and cost due to an additional process. The sample that will be examined within this paper is a non-ferromagnetic material such as aluminum which has a good acousto-elastic property, for an effective inspection of a bond quality for a nuclear fuel under a manufacturing environment. The purpose of this study is to investigate the feasibility of an EMAT technology for an automated inspection of a nuclear fuel without water

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

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

    2015-04-01

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

  2. Acoustic levitation of a large solid sphere

    Andrade, Marco A. B.; Bernassau, Anne L.; Adamowski, Julio C.

    2016-07-01

    We demonstrate that acoustic levitation can levitate spherical objects much larger than the acoustic wavelength in air. The acoustic levitation of an expanded polystyrene sphere of 50 mm in diameter, corresponding to 3.6 times the wavelength, is achieved by using three 25 kHz ultrasonic transducers arranged in a tripod fashion. In this configuration, a standing wave is created between the transducers and the sphere. The axial acoustic radiation force generated by each transducer on the sphere was modeled numerically as a function of the distance between the sphere and the transducer. The theoretical acoustic radiation force was verified experimentally in a setup consisting of an electronic scale and an ultrasonic transducer mounted on a motorized linear stage. The comparison between the numerical and experimental acoustic radiation forces presents a good agreement.

  3. Acoustic cloaking and transformation acoustics

    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)

  4. Acoustic cloaking and transformation acoustics

    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)

  5. Acoustical Imaging

    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

  6. Acoustic streaming jets: A scaling and dimensional analysis

    We present our work on acoustic streaming free jets driven by ultrasonic beams in liquids. These jets are steady flows generated far from walls by progressive acoustic waves. As can be seen on figure 1, our set-up, denominated AStrID for Acoustic Streaming Investigation Device, is made of a water tank in which a 29 mm plane source emits continuous ultrasonic waves at typically 2 MHz. Our approach combines an experimental characterization of both the acoustic pressure field (hydrophone) and the obtained acoustic streaming velocity field (PIV visualization) on one hand, with CFD using an incompressible Navier-Stokes solver on the other hand

  7. Electroacoustical simulation of listening room acoustics for project ARCHIMEDES

    Bech, Søren

    1989-01-01

    ARCHIMEDES is a psychoacoustics research project, funded under the European EUREKA scheme. Three partners share the work involved: The Acoustics Laboratory of The Technical University of Denmark; Bang and Olufsen of Denmark; and KEF Electronics of England. Its primary object is to quantify the influence of listening room acoustics on the timbre of reproduced sound. For simulation of the acoustics of a standard listening room, an electroacoustic setup has been built in an anechoic chamber. The...

  8. Estimating Discrete Power Angular Spectra in Multiprobe OTA Setups

    Fan, Wei; Nielsen, Jesper Ødum; Pedersen, Gert Frølund

    2014-01-01

    accurate direction-of-arrival estimates as well as power estimates of the impinging signals in the test zone. Simulation results match well with the target, as expected. Measurement results based on a virtual UCA in a practical 3-D multiprobe setup further support the simulation results. Possible reasons...

  9. Experimental setup for tungsten transport studies at the NSTX tokamak

    Tungsten particles have been introduced into the National Spherical Torus Experiment (NSTX) in Princeton with the purpose to investigate the effects of tungsten injection on subsequent plasma discharges. An experimental setup for the study of tungsten particle transport is described where the particles are introduced into the tokamak using a modified particle dropper, otherwise used for lithium-powder injection. An initial test employing a grazing-incidence extreme ultraviolet spectrometer demonstrates that the tungsten-transport setup could serve to infer particle transport from the edge to the hot central plasmas of NSTX.

  10. Radiation acoustics

    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...

  11. Non destructive testing by acoustic signature of damage level in 304L steel samples submitted to rolling, tensile test and thermal annealing treatments

    The aim of this work is to demonstrate the ability of acoustic signature technique to detect in a non-destructive way mechanical property variations due to damage of the internal material structure for 304L steel samples, provided by EDF company. For this purpose, the velocity and the attenuation of Rayleigh acoustic waves have been measured for rolled, drawn and thermally treated samples. Complementary information provided by echography have also been used to calculate the corresponding variations of the dynamic Young's modulus E

  12. Deep bleeder acoustic coagulation (DBAC)—Part I: development and in vitro testing of a research prototype cuff system

    Sekins, K Michael; Barnes, Stephen R.; Fan, Liexiang; Hopple, Jerry D.; Hsu, Stephen J.; Kook, John; Lee, Chi-Yin; Maleke, Caroline; Ramachandran, A R; Zeng, Xiaozheng (Jenny); Moreau-Gobard, Romain; Ahiekpor-Dravi, Alexis; Funka-Lea, Gareth; Mitchell, Stuart B.; Dunmire, Barbrina

    2015-01-01

    Background Bleeding from limb injuries is a leading cause of death on the battlefield, with deep wounds being least accessible. High-intensity focused ultrasound (HIFU) has been shown capable of coagulation of bleeding (cautery). This paper describes the development and refereed in vitro evaluation of an ultrasound (US) research prototype deep bleeder acoustic coagulation (DBAC) cuff system for evaluating the potential of DBAC in the battlefield. The device had to meet quantitative performanc...

  13. Examination of ceramic restoration adhesive coverage in cusp-replacement premolar using acoustic emission under fatigue testing

    Chang, Yen-Hsiang; Yu, Jin-Jie; Lin, Chun-Li

    2014-01-01

    Background This study investigates CAD/CAM ceramic cusp-replacing restoration resistance with and without buccal cusp replacement under static and dynamic cyclic loads, monitored using the acoustic emission (AE) technique. Method The cavity was designed in a typical MODP (mesial-occlusal-distal-palatal) restoration failure shape when the palatal cusp has been lost. Two ceramic restorations [without coverage (WOC) and with (WC) buccal cuspal coverage with 2.0 mm reduction in cuspal height] wer...

  14. Digital Set-Ups for Positron Annihilation Spectroscopy at PAS Laboratory Fei Stu Bratislava

    Current status of the digitization in Positron Lifetime and Coincidence Doppler Broadening spectroscopy set-ups at the Slovak University of Technology in Bratislava is described in this paper. In PALS set-ups two digitizer cards Acqiris DP-240 and Ztec ZT4612 with different parameters and abilities were tested. The first results from the Coincidence Doppler Broadening set-up using Adlink PCI-9820 digitizer card are presented. (author)

  15. Lightweight acoustic treatments for aerospace applications

    Naify, Christina Jeanne

    2011-12-01

    Increase in the use of composites for aerospace applications has the benefit of decreased structural weight, but at the cost of decreased acoustic performance. Stiff, lightweight structures (such as composites) are traditionally not ideal for acoustic insulation applications because of high transmission loss at low frequencies. A need has thus arisen for effective sound insulation materials for aerospace and automotive applications with low weight addition. Current approaches, such as the addition of mass law dominated materials (foams) also perform poorly when scaled to small thickness and low density. In this dissertation, methods which reduce sound transmission without adding significant weight are investigated. The methods presented are intended to be integrated into currently used lightweight structures such as honeycomb sandwich panels and to cover a wide range of frequencies. Layering gasses of differing acoustic impedances on a panel substantially reduced the amount of sound energy transmitted through the panel with respect to the panel alone or an equivalent-thickness single species gas layer. The additional transmission loss derives from successive impedance mismatches at the interfaces between gas layers and the resulting inefficient energy transfer. Attachment of additional gas layers increased the transmission loss (TL) by as much as 17 dB at high (>1 kHz) frequencies. The location and ordering of the gasses with respect to the panel were important factors in determining the magnitude of the total TL. Theoretical analysis using a transfer matrix method was used to calculate the frequency dependence of sound transmission for the different configurations tested. The method accurately predicted the relative increases in TL observed with the addition of different gas layer configurations. To address low-frequency sound insulation, membrane-type locally resonant acoustic materials (LRAM) were fabricated, characterized, and analyzed to understand their

  16. Acoustic engineering and technology '90

    Acoustic monitoring, testing and diagnosis in machines, production processes and products enhance the uptimes and profitability of machinery and plants. 18 papers discuss the current state of the art of acoustic monitoring systems including integrated factory planning as well as industrial health, and noise protection. (DG)

  17. Digital Controller For Acoustic Levitation

    Tarver, D. Kent

    1989-01-01

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

  18. Cyclic Crack Growth Testing of an A.O. Smith Multilayer Pressure Vessel with Modal Acoustic Emission Monitoring and Data Assessment

    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.

  19. Characterization of a neutron imaging setup at the INES facility

    The Italian Neutron Experimental Station (INES) located at the ISIS pulsed neutron source (Didcot, United Kingdom) provides a thermal neutron beam mainly used for diffraction analysis. A neutron transmission imaging system was also developed for beam monitoring and for aligning the sample under investigation. Although the time-of-flight neutron diffraction is a consolidated technique, the neutron imaging setup is not yet completely characterized and optimized. In this paper the performance for neutron radiography and tomography at INES of two scintillator screens read out by two different commercial CCD cameras is compared in terms of linearity, signal-to-noise ratio, effective dynamic range and spatial resolution. In addition, the results of neutron radiographies and a tomography of metal alloy test structures are presented to better characterize the INES imaging capabilities of metal artifacts in the cultural heritage field. -- Highlights: A full characterization of the present INES imaging set-up was carried out. Two CCD cameras and two scintillators (ZnS/6LiF) of different thicknesses were tested. Linearity, effective dynamic range and spatial resolution were determined. Radiographies of steep wedges were performed using the highest dynamic range setup. Tomography of a bronze cube was performed using the best spatial resolution setup

  20. An integrated optical/acoustic communication system for seafloor observatories: A field test of high data rate communications at CORK 857D

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

    2010-12-01

    We report the successful deployment and testing of an underwater optical communication system that provides high data rate communications over a range of 100 meters from a deep sea borehole observatory located in the northeast Pacific. Optical underwater communications offers many advantages over acoustic or underwater wet mateable connections (UWMC). UMWCs requires periodic visits from a submersible or ROV to plug in and download data. Typically, these vehicles cannot perform any other tasks during these download periods - their time on station is limited, restricting the amount of data that can be downloaded. To eliminate the need for UWMCs requires the use of remote communication techniques such as acoustics or optical communications. Optical communications is capable of high data rates up to 10 mega bits per sec (Mbps) compared to acoustic data rates of 57 Kbps. We have developed an integrated optical/acoustic telemetry system (OTS) that uses an acoustic command system to control a high bandwidth, low latency optical communication system. In July 2010, we used the deep submersible ALVIN to install the Optical Telemetry System (OTS) at CORK 857D. The CORK is instrumented with a thermistor string and pressure sensors that record downhole formation pressures and temperatures within oceanic basement that is pressure sealed from the overlying water column. The seafloor OTS was plugged into the CORK’s existing UWMC to provide an optical and acoustic communication interface and additional data storage and battery power for the CORK to sample at 1 Hz data-rate, an increase over the normal 15 sec data sample rate. Using a CTD-mounted OTS lowered by wire from a surface ship, we established an optical communication link at 100 meters range at rates of 1, 5 and 10 Mbps with no bit errors. Tests were also done to establish the optical range of various data rates and the optical power of the system. After a week, we repeated the CTD-OTS experiment and downloaded 20 Mbytes

  1. Battlefield acoustics

    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...

  2. Acoustical Imaging

    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...

  3. Acoustic telemetry

    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...

  4. Acoustics Research

    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....

  5. PC operated acoustic transient spectroscopy of deep levels in MIS structures

    A new version of acoustic deep-level transient spectroscopy is presented to study the traps at the insulator-semiconductor interface. The acoustic deep-level transient spectroscopy uses an acoustoelectric response signal produced by the MIS structure interface when a longitudinal acoustic wave propagates through a structure. The acoustoelectric response signal is extremely sensitive to external conditions of the structure and reflects any changes in the charge distribution, connected also with charged traps. In comparison with previous version of acoustic deep-level transient spectroscopy that closely coincides with the principle of the original deep-level transient spectroscopy technique, the present technique is based on the computer-evaluated isothermal transients and represents an improved, more efficient and time saving technique. Many tests on the software used for calculation as well as on experimental setup have been performed. The improved acoustic deep-level transient spectroscopy method has been applied for the Si(p) MIS structures. The deep-level parameters as activation energy and capture cross-section have been determined. (authors)

  6. Acoustic fault injection tool (AFIT)

    Schoess, Jeffrey N.

    1999-05-01

    On September 18, 1997, Honeywell Technology Center (HTC) successfully completed a three-week flight test of its rotor acoustic monitoring system (RAMS) at Patuxent River Flight Test Center. This flight test was the culmination of an ambitious 38-month proof-of-concept effort directed at demonstrating the feasibility of detecting crack propagation in helicopter rotor components. The program was funded as part of the U.S. Navy's Air Vehicle Diagnostic Systems (AVDS) program. Reductions in Navy maintenance budgets and available personnel have dictated the need to transition from time-based to 'condition-based' maintenance. Achieving this will require new enabling diagnostic technologies. The application of acoustic emission for the early detection of helicopter rotor head dynamic component faults has proven the feasibility of the technology. The flight-test results demonstrated that stress-wave acoustic emission technology can detect signals equivalent to small fatigue cracks in rotor head components and can do so across the rotating articulated rotor head joints and in the presence of other background acoustic noise generated during flight operation. During the RAMS flight test, 12 test flights were flown from which 25 Gbyte of digital acoustic data and about 15 hours of analog flight data recorder (FDR) data were collected from the eight on-rotor acoustic sensors. The focus of this paper is to describe the CH-46 flight-test configuration and present design details about a new innovative machinery diagnostic technology called acoustic fault injection. This technology involves the injection of acoustic sound into machinery to assess health and characterize operational status. The paper will also address the development of the Acoustic Fault Injection Tool (AFIT), which was successfully demonstrated during the CH-46 flight tests.

  7. Absorption boundary conditions for geomertical acoustics

    Jeong, Cheol-Ho

    2012-01-01

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

  8. Scintillation forward spectrometer of the SPHERE setup

    The construction of the forward spectrometer for the 4π SPHERE setup to study multiple production of particles in nucleus-nucleus interactions is described. The measured parameters of the spectrometer detectors are presented. 7 refs.; 14 figs.; 1 tab

  9. Embedded Acoustic Sensor Array for Engine Fan Noise Source Diagnostic Test: Feasibility of Noise Telemetry via Wireless Smart Sensors

    Zaman, Afroz; Bauch, Matthew; Raible, Daniel

    2011-01-01

    Aircraft engines have evolved into a highly complex system to meet ever-increasing demands. The evolution of engine technologies has primarily been driven by fuel efficiency, reliability, as well as engine noise concerns. One of the sources of engine noise is pressure fluctuations that are induced on the stator vanes. These local pressure fluctuations, once produced, propagate and coalesce with the pressure waves originating elsewhere on the stator to form a spinning pressure pattern. Depending on the duct geometry, air flow, and frequency of fluctuations, these spinning pressure patterns are self-sustaining and result in noise which eventually radiate to the far-field from engine. To investigate the nature of vane pressure fluctuations and the resulting engine noise, unsteady pressure signatures from an array of embedded acoustic sensors are recorded as a part of vane noise source diagnostics. Output time signatures from these sensors are routed to a control and data processing station adding complexity to the system and cable loss to the measured signal. "Smart" wireless sensors have data processing capability at the sensor locations which further increases the potential of wireless sensors. Smart sensors can process measured data locally and transmit only the important information through wireless communication. The aim of this wireless noise telemetry task was to demonstrate a single acoustic sensor wireless link for unsteady pressure measurement, and thus, establish the feasibility of distributed smart sensors scheme for aircraft engine vane surface unsteady pressure data transmission and characterization.

  10. Optymisation of equipment setup processes in enterprises

    Grzybowska, K.; Gajdzik, B.

    2012-01-01

    Fast equipment setup in a machine on production line is the key precondition to increase the fl exibility of the production. Methodology of SMED (Single Minute Exchange of Die) is an example which allows reducing the time of setup practically to the minimum. The article presents the theoretical bases and required rules as well as case study conducted in one of chosen enterprises. This paper also answers the question if SMED methodology is applicable in metallurgical sector, presenting the exa...

  11. PGNAA neutron source moderation setup optimization

    Zhang, Jinzhao; Tuo, Xianguo

    2013-01-01

    Monte Carlo simulations were carried out to design a prompt {\\gamma}-ray neutron activation analysis (PGNAA) thermal neutron output setup using MCNP5 computer code. In these simulations the moderator materials, reflective materials and structure of the PGNAA 252Cf neutrons of thermal neutron output setup were optimized. Results of the calcuations revealed that the thin layer paraffin and the thick layer of heavy water moderated effect is best for 252Cf neutrons spectrum. The new design compar...

  12. VSS BASED SESSION SETUP MECHANISM IN IMS

    Cao Yufei; Liao Jianxin; Qi Qi; Zhu Xiaomin

    2009-01-01

    This paper proposes a novel session setup mechanism in IMS (IP Multimedia Subsystem) by introducing the functional entity termed VSS (Visitor Subscriber Server) which is used to provide registration and location management.The new mechanism aims at improving session setup procedure by a betterment of location management in IMS.Through the use of two-tier subscriber information database constituted by the HSS (Home Subscriber Server) and the VSS,the new mechanism seperates the registration procedure and location management from the S-CSCF (Serving-Call'Session Control Function),and makes them be handled by the VSS.At the same time,the new mechanism updates the signaling procedure of registration and session setup.With VSS based location management.the cost of registeration and session setup procedure as well as the delay of session setup procedure become lower.he cost and delay functious of the new session setup mechanism as well aus the cost function of new registeration are deduced.Then,simulations and analysis verify that the performance of this new mechanism gets the benefit in cost and time.

  13. Mechanisms of plastic instability and fracture of compressed and tensile tested Mg-Li alloys investigated using the acoustic emission method

    A. Pawełek

    2016-01-01

    Full Text Available The results of the investigation of both mechanical and acoustic emission (AE behaviors of Mg4Li5Al alloy subjected to compression and tensile tests at room temperature are compared with the test results obtained using the same alloy and loading scheme but at elevated temperatures. The main aim of the paper is to investigate, to determine and to explain the possible influence of factors related with enhanced internal stresses such as: segregation of precipitates along grain boundaries or solute atoms along dislocations (Cottrell atmospheres or dislocation pile-ups at grain boundaries which create very high stress concentration leading to fracture. The results show that the plastic instabilities are related to the Portevin–Le Châtelier phenomenon (PL effect and they are correlated with the generation of AE peaks. The fractography of breaking samples was analyzed on the basis of light (optical, TEM and SEM images.

  14. Damage assessed by wavelet scale bands and b-value in dynamical tests of a reinforced concrete slab monitored with acoustic emission

    Zitto, Miguel E.; Piotrkowski, Rosa; Gallego, Antolino; Sagasta, Francisco; Benavent-Climent, Amadeo

    2015-08-01

    The complex Morlet Continuous Wavelet Transform (CWT) was applied to acoustic emission (AE) signals from dynamic tests conducted on a reinforced concrete slab with a shaking table. The steel reinforcement bars did not yield during the tests, but a severe loss of bond between reinforcement bars and surrounding concrete was detected. Comparison of the evolution of the scale position of maximum values of CWT coefficients and the histories of response acceleration obtained in different seismic simulations allowed us to identify the (45-64 kHz) frequency band corresponding to the fracture of concrete. The Cumulative Acoustic Emission Energy (CAE) obtained by reconstructing the AE signals in this scale (frequency) band was compared with the Cumulative Dissipated Energy (CDE) of the tested structure. The CDE is accepted as a good parameter for characterizing the mechanical damage in structures. A reasonably good agreement was found between the normalized histories of CAE and CDE. This made it possible to categorize the cracking of concrete as the main source of damage in the reinforced concrete slab. Conversely, the differences between the CAE and CDE curves observed for high levels of peak acceleration applied to the shaking table can be attributed to the deformation of the steel that formed the columns. The AE coming from the plastic deformation of the steel is not detected by CAE due to the threshold amplitude (45 dB) used in the AE monitoring, but the strain energy dissipated by the steel through plastic deformations is included in the CDE. Further, a study of the evolution of the b-value in the successive seismic simulations revealed that the b-value can capture the inception of severe cracking in the concrete, which the tests described in this study attributed mainly to the loss of bond between reinforcing steel and surrounding concrete.

  15. Synthesis of anisotropic swirling surface acoustic waves by inverse filter, towards integrated generators of acoustical vortices

    Riaud, Antoine; Charron, Eric; Bussonnière, Adrien; Matar, Olivier Bou

    2015-01-01

    From radio-electronics signal analysis to biological samples actuation, surface acoustic waves (SAW) are involved in a multitude of modern devices. Despite this versatility, SAW transducers developed up to date only authorize the synthesis of the most simple standing or progressive waves such as plane and focused waves. In particular, acoustical integrated sources able to generate acoustical vortices (the analogue of optical vortices) are missing. In this work, we propose a flexible tool based on inverse filter technique and arrays of SAW transducers enabling the synthesis of prescribed complex wave patterns at the surface of anisotropic media. The potential of this setup is illustrated by the synthesis of a 2D analog of 3D acoustical vortices, namely "swirling surface acoustic waves". Similarly to their 3D counterpart, they appear as concentric structures of bright rings with a phase singularity in their center resulting in a central dark spot. Swirling SAW can be useful in fragile sensors whose neighborhood...

  16. Acoustic detection of pneumothorax

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

    2003-04-01

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

  17. Procedure for the creation of reproducible acoustic coupling using the ultrasonic contact method for nondestructive testing of materials

    The transducer is pressed to the specimen, a lubricating coating being applied as an intermediate layer. By means of a vibrator belonging to the transducer there are generated vibrations, the growth rate of the amplitude of the reflected signal picked up being observed. This growth rate is monotonously decreasing. If the growth rate is abruptly decreasing or if the amplitude of the measured signal remains constant the vibrator is turned off, because now good acoustic contact is established. After a short time of waiting for the residual stress of the transducer to decay, recording of the ultrasonic parameters may then be taken up. The method can be applied to thickness measurements and inhomogeneous materials with low surface quality. (RW)

  18. Experimental setup for the measurement of induction motor cage currents

    An experimental setup for measurement of the currents flowing in the rotor bars of induction motors during synchronous no-load tests is described in the paper. The experimental verification of the high-frequency phenomena in the rotor cage is fundamental for a deep insight of the additional loss estimation by numerical methods. The attention is mainly focused on the analysis and design of the transducers developed for the cage current measurement

  19. Experimental Results for Direction of Arrival Estimation with a Single Acoustic Vector Sensor in Shallow Water

    Alper Bereketli

    2015-01-01

    Full Text Available We study the performances of several computationally efficient and simple techniques for estimating direction of arrival (DOA of an underwater acoustic source using a single acoustic vector sensor (AVS in shallow water. Underwater AVS is a compact device, which consists of one hydrophone and three accelerometers in a packaged form, measuring scalar pressure and three-dimensional acceleration simultaneously at a single position. A very controlled experimental setup is prepared to test how well-known techniques, namely, arctan-based, intensity-based, time domain beamforming, and frequency domain beamforming methods, perform in estimating DOA of a source in different circumstances. Experimental results reveal that for almost all cases beamforming techniques perform best. Moreover, arctan-based method, which is the simplest of all, provides satisfactory results for practical purposes.

  20. Generic Planning Target Margin for Rectal Cancer Treatment Setup Variation

    Purpose: To calculate the generic planning target margin (GPTM) for patients receiving radiation therapy (RT) for rectal cancer placed in a prone position with a customized cradle for small-bowel exclusion. Methods and Materials: A total of 25 consecutive rectal cancer patients were treated for 25 or 28 fractions in a prone position using a cradle to maximize small bowel exclusion. Treatment planning computed tomography (CT) scans were used to create orthogonally digitally reconstructed radiographs (DRRs) for portal image registration, which were compared with daily portal images from an electronic portal-imaging device (EPID). Translation values needed to align the DRRs and EPIDs were recorded for the superior to inferior (SI), right to left (RL), and anterior to posterior (AP) directions, and used to calculate the GPTM using the four-parameter model. Age, weight, and body mass index were tested compared with the setup variation using a Pearson correlation and a t test for significance. Gender versus setup variation was compared with a t test. Results: A total of 1,723 EPID images were reviewed. The GPTM was 10 mm superior, 8 mm inferior, 7 mm RL and 10 mm AP. Age and gender were unrelated to setup variation. Weight was significantly associated with systematic AP variation (p < 0.05). BMI was significantly associated with systematic SI (p < 0.05) and AP (p < 0.01) variation and random RL variation (p < 0.05). Conclusions: The GPTM for rectal cancer is asymmetric with a maximum of 10 mm in the superior, anterior and posterior dimensions. Body mass index may effect setup variation. Research using advanced treatment planning should include these margins in the planning target volume definition.

  1. Integrating fluorescent dye flow-curve testing and acoustic Doppler velocimetry profiling for in situ hydraulic evaluation and improvement of clarifier performance.

    Tarud, F; Aybar, M; Pizarro, G; Cienfuegos, R; Pastén, P

    2010-08-01

    Enhancing the performance of clarifiers requires a thorough understanding of their hydraulics. Fluorescence spectroscopy and acoustic doppler velocimeter (ADV) profiling generally have been used separately to evaluate secondary settlers. We propose that simultaneous use of these techniques is needed to obtain a more reliable and useful evaluation. Experiments were performed on laboratory- and full-scale clarifiers. Factors affecting Fluorescein and Rhodamine 6G properties were identified. Underestimations up to 500% in fluorescence intensities may be derived from differential fluorescence quenching by oxygen. A careful control and interpretation of fluorescent dye experiments is needed to minimize artifacts in real settings. While flow-curve tests constructed under controlled conditions provided a more accurate overall quantitative estimation of the hydraulic performance, ADV velocity and turbulence profiling provided a detailed spatial understanding of flow patterns that was used to troubleshoot and fix the causes of hydraulic short-circuits. PMID:20853746

  2. Braneworld setup and embedding in teleparallel gravity

    We construct the setup of a five-dimensional braneworld scenario in teleparallel gravity. Both cases of Minkowski and Friedmann–Robertson–Walker branes embedded in anti-de Sitter bulk are studied and the effective 4D action were studied. 4-dimensional local Lorentz invariance is found to be recovered in both cases. However, due to different junction conditions, the equations governing the 4D cosmological evolution differ from general relativistic case. Using the results of Ref. [13], we consider a simple inflationary scenario in this setup. The inflation parameters are found to be modified compared to general relativistic case

  3. Optymisation of equipment setup processes in enterprises

    K. Grzybowska

    2012-10-01

    Full Text Available Fast equipment setup in a machine on production line is the key precondition to increase the fl exibility of the production. Methodology of SMED (Single Minute Exchange of Die is an example which allows reducing the time of setup practically to the minimum. The article presents the theoretical bases and required rules as well as case study conducted in one of chosen enterprises. This paper also answers the question if SMED methodology is applicable in metallurgical sector, presenting the example of shortening the time between the production of various metallurgical products manufactured in the machine for continuous casting of steel (COS in Polish.

  4. Braneworld setup and embedding in teleparallel gravity

    A. Behboodi

    2015-01-01

    Full Text Available We construct the setup of a five-dimensional braneworld scenario in teleparallel gravity. Both cases of Minkowski and Friedmann–Robertson–Walker branes embedded in anti-de Sitter bulk are studied and the effective 4D action were studied. 4-dimensional local Lorentz invariance is found to be recovered in both cases. However, due to different junction conditions, the equations governing the 4D cosmological evolution differ from general relativistic case. Using the results of Ref. [13], we consider a simple inflationary scenario in this setup. The inflation parameters are found to be modified compared to general relativistic case.

  5. Computational modeling of magnets for electrophysical setups

    The design, construction and operation of magnetic systems of some electrophysical setups require preliminary mathematical modeling. While calculating the fields of the magnetic systems mentioned (based on solving a set of direct problems of magnetostatics), we attempted to solve the inverse problem of magnetostatics, namely, to find an optimal construction of the current elements and ferromagnetic yoke for a required distribution of the magnetic field. This work discusses the results of numerical modeling of the magnet field distribution for some modifications of the SP-94 spectrometric magnet used in some experimental setups

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

    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.

  7. Building and commissioning of a setup to study ageing phenomena in gaseous detectors

    Abuhoza, A.; Schmidt, H. R.; Biswas, S.; Frankenfeld, U.; Hehner, J.; Schmidt, C. J.

    2016-07-01

    In high-rate heavy-ion experiments, gaseous detectors encounter big challenges in terms of degradation of their performance due to a phenomenon called ageing. A setup for high precision ageing studies has been constructed and commissioned at the GSI detector laboratory. The setup as well as the gas system have been carefully optimized to reach a high sensitivity for ageing effects. Two different materials have been examined for their influence on gaseous detectors: RTV-3145 and Gerband 705. The details of the construction of the ageing test setup and the test results will be presented.

  8. 350 keV accelerator-based neutron transmission setup at KFUPM for hydrogen detection

    Naqvi, A; Maslehuddin, M; Kidwai, S; Nassar, R

    2002-01-01

    An experimental setup has been developed to determine hydrogen contents of bulk samples using fast neutron transmission technique. Neutrons with 3 MeV energy were produced via D(d, n) reaction. The neutrons transmitted through the sample were detected by a NE213 scintillation detector. Preliminary tests of the setup were carried out using soil samples with different moisture contents. In addition to experimental study, Monte Carlo simulations were carried out to generate calibration curve of the experimental setup. Finally, experimental tests results were compared with the results of Monte Carlo simulations. A good agreement has been obtained between the simulation results and experimental results.

  9. Development of an autonomous setup for evaluating self healing capability of asphalt mixtures

    Qiu, J.; Molenaar, A.A.A.; Van de Ven, M.F.C.; Wu, S.

    2012-01-01

    It is a well known fact that asphalt mixtures have self healing capabilities. Yet most of the self healing investigations are carried out using complex and time consuming fatigue tests. In order to investigate the self healing capability in a simple and efficient manner, a beam on elastic foundation test setup (BOEF) is proposed in this paper. With a notched asphalt concrete beam fully glued on a low modulus rubber foundation, the BOEF setup is able to control the self healing process autonom...

  10. Small solid angle device setup and application

    To quantize the weight of Uranium-plate accurately, the small solid angle device was redesigned. To fit the requirement of homogeneity check, the sliding base was introduced in the design. This paper presents the detailed application of small solid angle device setup and quantization of Uranium-plate and homogeneity check. (authors)

  11. Aligning the μs-ALEX Setup.

    Kapanidis, Achillefs; Majumdar, Devdoot; Heilemann, Mike; Nir, Eyal; Weiss, Shimon

    2015-11-01

    To achieve single-molecule sensitivity and thus have the ability to detect single diffusing fluorophores, careful alignment of the microsecond-alternating laser excitation (μs-Alex) setup is crucial. The following protocol describes routine alignment for 2c-ALEX (532 nm/635 nm) with spectral windows G(550-620)R(650-750). PMID:26527766

  12. Composite Inflation Setup and Glueball Inflation

    Bezrukov, Fedor; Channuie, Phongpichit; Jark Joergensen, Jakob;

    2012-01-01

    We explore the paradigm according to which inflation is driven by a four-dimensional strongly coupled dynamics coupled non-minimally to gravity. We start by introducing the general setup, both in the metric and Palatini formulation, for generic models of composite inflation. We then analyze the...

  13. Bitwise identical compiling setup: prospective for reproducibility and reliability of earth system modeling

    R. Li

    2015-11-01

    Full Text Available Reproducibility and reliability are fundamental principles of scientific research. A compiling setup that includes a specific compiler version and compiler flags is essential technical supports for Earth system modeling. With the fast development of computer software and hardware, compiling setup has to be updated frequently, which challenges the reproducibility and reliability of Earth system modeling. The existing results of a simulation using an original compiling setup may be irreproducible by a newer compiling setup because trivial round-off errors introduced by the change of compiling setup can potentially trigger significant changes in simulation results. Regarding the reliability, a compiler with millions of lines of codes may have bugs that are easily overlooked due to the uncertainties or unknowns in Earth system modeling. To address these challenges, this study shows that different compiling setups can achieve exactly the same (bitwise identical results in Earth system modeling, and a set of bitwise identical compiling setups of a model can be used across different compiler versions and different compiler flags. As a result, the original results can be more easily reproduced; for example, the original results with an older compiler version can be reproduced exactly with a newer compiler version. Moreover, this study shows that new test cases can be generated based on the differences of bitwise identical compiling setups between different models, which can help detect software bugs or risks in the codes of models and compilers and finally improve the reliability of Earth system modeling.

  14. Continuous acoustic emission monitoring of reinforced concrete under accelerated corrosion

    Di Benedetti, M.; Loreto, G.; Nanni, A.; Matta, F.; Gonzalez-Nunez, M. A.

    2011-04-01

    The development of techniques capable of evaluating deterioration of reinforced concrete (RC) structures is instrumental to the advancement of techniques for the structural health monitoring (SHM) and service life estimate for constructed facilities. One of the main causes leading to degradation of RC is the corrosion of the steel reinforcement. This process can be modeled phenomenologically, while laboratory tests aimed at studying durability responses are typically accelerated in order to provide useful results within a realistic period of time. To assess the condition of damage in RC, a number of nondestructive methods have been recently studied. Acoustic emission (AE) is emerging as a nondestructive tool to detect the onset and progression of deterioration mechanisms. In this paper, the development of accelerated corrosion and continuous AE monitoring test set-up for RC specimens are presented. Relevant information are provided with regard to the characteristics of the corrosion circuit, continuous measurement and acquisition of corrosion potential, selection of AE sensors and AE parameter setting. The effectiveness of the setup in detecting and characterizing the initiation and progression of the corrosion phenomenon is discussed on the basis of preliminary results from small-scale, pre-cracked RC specimens, which are representative of areas near the clear cover in typical RC bridge members.

  15. Effect of acoustic field parameters on arc acoustic binding during ultrasonic wave-assisted arc welding.

    Xie, Weifeng; Fan, Chenglei; Yang, Chunli; Lin, Sanbao

    2016-03-01

    As a newly developed arc welding method, power ultrasound has been successfully introduced into arc and weld pool during ultrasonic wave-assisted arc welding process. The advanced process for molten metals can be realized by utilizing additional ultrasonic field. Under the action of the acoustic wave, the plasma arc as weld heat source is regulated and its characteristics make an obvious change. Compared with the conventional arc, the ultrasonic wave-assisted arc plasma is bound significantly and becomes brighter. To reveal the dependence of the acoustic binding force on acoustic field parameters, a two-dimensional acoustic field model for ultrasonic wave-assisted arc welding device is established. The influences of the radiator height, the central pore radius, the radiator radius, and curvature radius or depth of concave radiator surface are discussed using the boundary element method. Then the authors analyze the resonant mode by this relationship curve between acoustic radiation power and radiator height. Furthermore, the best acoustic binding ability is obtained by optimizing the geometric parameters of acoustic radiator. In addition, three concave radiator surfaces including spherical cap surface, paraboloid of revolution, and rotating single curved surface are investigated systematically. Finally, both the calculation and experiment suggest that, to obtain the best acoustic binding ability, the ultrasonic wave-assisted arc welding setup should be operated under the first resonant mode using a radiator with a spherical cap surface, a small central pore, a large section radius and an appropriate curvature radius. PMID:26558995

  16. Numerical study of a confocal ultrasonic setup for creation of cavitation

    Lafond, Maxime, E-mail: maxime.lafond@inserm.fr; Chavrier, Françoise; Prieur, Fabrice [Inserm, U1032, LabTau, Lyon, F-69003 (France); Université de Lyon, Lyon, F-69003 (France); Université Lyon 1, Lyon, F-69003 (France); Mestas, Jean-Louis; Lafon, Cyril [Inserm, U1032, LabTau, Lyon, F-69003 (France); Université de Lyon, Lyon, F-69003 (France); Université Lyon 1, Lyon, F-69003 (France); Caviskills SAS, Vaulx-En-Velin, F-69120 (France)

    2015-10-28

    Acoustic cavitation is used for various therapeutic applications such as local enhancement of drug delivery, histotripsy or hyperthermia. One of the utmost important parameter for cavitation creation is the rarefaction pressure. The typical magnitude of the rarefaction pressure required to initiate cavitation from gas dissolved in tissue is beyond the range of the megapascal. Because nonlinear effects need to be taken into account, a numerical simulator based on the Westervelt equation was used to study the pressure waveform and the acoustic field generated by a setup for creation of cavitation consisting of two high intensity focused ultrasound transducers mounted confocally. At constant acoustic power, simulations with only one and both transducers from the confocal setup showed that the distortion of the pressure waveform due to the combined effects of nonlinearity and diffraction is less pronounced when both confocal transducers are used. Consequently, the confocal setup generates a greater peak negative pressure at focus which is more favorable for cavitation initiation. Comparison between the confocal setup and a single transducer with the same total emitting surface puts in evidence the role of the spatial separation of the two beams. Furthermore, it has been previously shown that the location of the peak negative pressure created by a single transducer shifts from focus towards the transducers in the presence of nonlinear effects. The simulator was used to study a configuration where the acoustical axes of transducers intersect on the peak negative pressure instead of the geometrical focus. For a representative confocal setup, namely moderate nonlinear effects, a 2% increase of the peak negative pressure and 8% decrease of the peak positive pressure resulted from this configuration. These differences tend to increase by increasing nonlinear effects. Although the optimal position of the transducers varies with the nonlinear regimen, the intersection point

  17. Numerical study of a confocal ultrasonic setup for creation of cavitation

    Acoustic cavitation is used for various therapeutic applications such as local enhancement of drug delivery, histotripsy or hyperthermia. One of the utmost important parameter for cavitation creation is the rarefaction pressure. The typical magnitude of the rarefaction pressure required to initiate cavitation from gas dissolved in tissue is beyond the range of the megapascal. Because nonlinear effects need to be taken into account, a numerical simulator based on the Westervelt equation was used to study the pressure waveform and the acoustic field generated by a setup for creation of cavitation consisting of two high intensity focused ultrasound transducers mounted confocally. At constant acoustic power, simulations with only one and both transducers from the confocal setup showed that the distortion of the pressure waveform due to the combined effects of nonlinearity and diffraction is less pronounced when both confocal transducers are used. Consequently, the confocal setup generates a greater peak negative pressure at focus which is more favorable for cavitation initiation. Comparison between the confocal setup and a single transducer with the same total emitting surface puts in evidence the role of the spatial separation of the two beams. Furthermore, it has been previously shown that the location of the peak negative pressure created by a single transducer shifts from focus towards the transducers in the presence of nonlinear effects. The simulator was used to study a configuration where the acoustical axes of transducers intersect on the peak negative pressure instead of the geometrical focus. For a representative confocal setup, namely moderate nonlinear effects, a 2% increase of the peak negative pressure and 8% decrease of the peak positive pressure resulted from this configuration. These differences tend to increase by increasing nonlinear effects. Although the optimal position of the transducers varies with the nonlinear regimen, the intersection point

  18. Acoustic lenses

    Acoustic lenses focus ultrasound to produce pencil-like beams with reduced near fields. When fitted to conventional (flat-faced) transducers, such lenses greatly improve the ability to detect and size defects. This paper describes a program developed to design acoustic lenses for use in immersion or contact inspection, using normal or angle beam mode with flat or curved targets. Lens surfaces are circular in geometry to facilitate machining. For normal beam inspection of flat plate, spherical or cylindrical lenses are used. For angle beam or curved surface inspections, a compound lens is required to correct for the extra induced aberration. Such a lens is aspherical with one radius of curvature in the plane of incidence, and a different radius of curvature in the plane perpendicular to the incident plane. The resultant beam profile (i.e., location of the acoustic focus, beam diameter, 6 dB working range) depends on the degree of focusing and the transducer used. The operating frequency and bandwidth can be affected by the instrumentation used. Theoretical and measured beam profiles are in good agreement. Various applications, from zone focusing used for defect sizing in thick plate, to line focusing for pipe weld inspection, are discussed

  19. PORTABLE ACOUSTIC MONITORING PACKAGE (PAMP)

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

    2004-07-20

    The Portable Acoustic Monitoring Package (PAMP) has been designed to record and monitor the acoustic signal in natural gas transmission lines. In particular the three acoustic signals associated with a line leak. The system is portable ({approx}30 lbs) and is designed for line pressures up to 1000 psi. It has become apparent that cataloging of the various background acoustic signals in natural gas transmission line is very important if a system to identify leak signals is to be developed. The low-pressure (0-200 psig) laboratory test phase has been completed and a number of field trials have been conducted. Before the cataloging phase could begin, a few problems identified in field trials identified had to be corrected such as: (1) Decreased microphone sensitivity at line pressures above 250 psig. (2) The inability to deal with large data sets collected when cataloging the variety of signals in a transmission line. (3) The lack of an available online acoustic calibration system. These problems have been solved and the WVU PAMP is now fully functional over the entire pressure range found in the Natural Gas transmission lines in this region. Field portability and reliability have been greatly improved. Data collection and storage have also improved to the point were the full acoustic spectrum of acoustic signals can be accurately cataloged, recorded and described.

  20. The design of a test procedure for the measurement of acoustic damping of materials at low stress.

    Heidgerken, Ricky A.

    1983-01-01

    Approved for public release; distribution is unlimited A procedure for measuring the viscous damping of relatively large plate material (up to 40 inches x 14 inches x 2 inches) was developed utilizing the Hewlett-Packard 5451C Fourier Analyzer and impulse hammer technique under very low stress conditions. Testing environment can be lab air or nondistilled water in the temperature range from 30° F to 90° F. The test procedure includes modal analysis that is expand...

  1. PGNAA neutron source moderation setup optimization

    Zhang, Jinzhao

    2013-01-01

    Monte Carlo simulations were carried out to design a prompt {\\gamma}-ray neutron activation analysis (PGNAA) thermal neutron output setup using MCNP5 computer code. In these simulations the moderator materials, reflective materials and structure of the PGNAA 252Cf neutrons of thermal neutron output setup were optimized. Results of the calcuations revealed that the thin layer paraffin and the thick layer of heavy water moderated effect is best for 252Cf neutrons spectrum. The new design compared with the conventional neutron source design, the thermal neutron flux and rate were increased by 3.02 times and 3.27 times. Results indicate that the use of this design should increase the neutron flux of prompt gamma-ray neutron activation analysis significantly.

  2. Propagation behavior of acoustic wave in wood

    Huadong Xu; Guoqi Xu; Lihai Wang; Lei Yu

    2014-01-01

    We used acoustic tests on a quarter-sawn poplar timbers to study the effects of wood anisotropy and cavity defects on acoustic wave velocity and travel path, and we investigated acoustic wave propagation behavior in wood. The timber specimens were first tested in unmodified condition and then tested after introduction of cavity defects of varying sizes to quantify the transmitting time of acoustic waves in laboratory conditions. Two-dimensional acoustic wave contour maps on the radial section of specimens were then simulated and analyzed based on the experimental data. We tested the relationship between wood grain and acoustic wave velocity as waves passed in various directions through wood. Wood anisotropy has significant effects on both velocity and travel path of acoustic waves, and the velocity of waves passing longitudinally through timbers exceeded the radial velocity. Moreover, cavity defects altered acoustic wave time contours on radial sections of timbers. Acous-tic wave transits from an excitation point to the region behind a cavity in defective wood more slowly than in intact wood.

  3. Test of the feasibility and accuracy of mass and velocity measurements of pellets in flight in a microwave set-up with a pass-hole in the transmission line

    The feasibility of mass and velocity measurements on pellets in flight without use of optical equipment has been tested. The mass is measured by a microwave system, and the velocity is measured by a time of flight in a double interaction with the microwave system. The influence of the size of the passholes in the microwave guide tube has been discussed. (orig.) With 29 figs

  4. Acoustic emission analysis in overall fatigue testing of a wind rotor blade; Schallemissionsanalyse beim Gesamtermuedungstest eines Windkraftrotorblattes

    Schulze, Eberhard; Frankenstein, Bernd; Schubert, Lars [Fraunhofer-Instiut fuer Zerstoerungsfreie Pruefverfahren (IZFP), Dresden (Germany)

    2009-07-01

    The Fraunhofer Institut fuer zerstoerungsfreie Pruefverfahren Dresden (IZFP-D, Fraunhofer Institute of Nondestructive Testing) is developing condition monitoring systems (CMS) for safety-relevant components. By permanent monitoring, e.g. of wind rotors, aircraft components or pipelines, these systems will ensure high avalability during the whole component life. Crack initiation, crack propagation or delamination can be detected and repaired at an early stage. Early repair will prolong the component life, and outage periods can be reduced. Currently, full-scale fatigue tests are made on a 40 m wind rotor blade of CFRP and GFRP materials. After a static pre-load period, 2,000,000 fatigue cycles will be applied. The contribution describes the measuring technology and the evaluation methods, in particular event identification and parametrization. Finally, the current experimental status is outlined, fatigue test results so far are presented, and development trends are indicated. (orig.)

  5. Measurements of operator performance - an experimental setup

    The human has to be considered as an important element in a process control system, even if the degree of automation is extremely high. Other elements, e.g. computer, displays, etc., can to a large extent be described and quantified. The human (operator), is difficult to describe in a precise way, and it is just as difficult to predict his thinking and acting in a control room environment. Many factors influence his performance, such as: experience, motivation, level of knowledge, training, control environment, job organization, etc. These factors have to a certain degree to be described before guidelines for design of the man-process interfaces and the control room layout can be developed. For decades, the psychological science has obtained knowledge of the human mind and behaviour. This knowledge should have the potential of a positive input on our effort to describe the factors influencing the operator performance. Even if the human is complex, a better understanding of his thinking and acting, and a more precise description of the factors influencing his performance can be obtained. At OECD Halden Reactor Project an experimental set-up for such studies has been developed and implemented in the computer laboratory. The present set-up includes elements as a computer- and display-based control room, a simulator representing a nuclear power plant, training programme for the subjects, and methods for the experiments. Set-up modules allow reconfiguration of experiments. (orig./HP)

  6. Design Aspects of an Experimental Setup for Investigating Current Ripple Effects in Lithium-ion Battery Cells

    Soares, Rudi; Bessman, Alexander; Wallmark, Oskar; Leksell, Mats; Behm, Mårten; Svens, Pontus

    2015-01-01

    This paper describes an experimental setup for investigating the effects of current ripple on lithium-ion battery cells. The experimental setup is designed so that twelve li-ion cells can be simultaneously tested in a controlled environment. The experimental setup allows for a wide range of current ripple in terms of frequency and amplitude. Additionally, the quantification of the current ripple effects such as the aging of li-ion cells implies that a precise measurement system has to be desi...

  7. Comparison of two setups for induction heating in injection molding

    Menotti, Stefano; Hansen, Hans Nørgaard; Bissacco, Giuliano;

    2015-01-01

    To eliminate defects and improve the quality of molded parts, increasing the mold temperature is one of the applicable solutions. A high mold temperature can increase the path flow of the polymer inside the cavity allowing reduction of the number of injection points, reduction of part thickness......, and moulding of smaller and more complex geometries. The last two aspects are very important in micro injection molding. In this paper, a new embedded induction heating system is proposed and validated and two different coil setups were tested and compared. An experimental investigation was performed...... based on a test geometry integrating different aspect ratios of small structures. Acrylonitrile butadiene styrene (ABS) was used as material, and different mold temperatures were tested. The replicated test objects were measured by means of an optical coordinate measuring machine (CMM). On the basis of...

  8. A simple configuration setup for compton suppression spectroscopy

    Hai, N X; Dien, N N; Tan, V H; Hoa, N D

    2013-01-01

    The fast timing, standard timing and easy timing are popular timing configurations of compton suppression spectroscopy. Such spectroscopes always use a module of coincidence or time-to-amplitude converter (TAC). A compton suppression spectroscopy with semi-timing configuration is presented in this paper. The semi-timing configuration is relatively simple and easy system setup, especially this spectroscopy does not need to use module of coincidence or TAC. The performance of spectroscopy was tested and summarized. The count rate background, full peak efficiency and the ratios of area/background of peaks in suppressed and unsuppressed modes were comparative.

  9. All-reflective femtosecond optical pump-probe setup for transient grating spectroscopy.

    Cucini, R; Bencivenga, F; Masciovecchio, C

    2011-04-01

    We developed a pump-probe setup that can be used for free electron lasers based four-wave mixing experiments in the extreme ultraviolet/soft x-ray spectral range. The main feature of the proposed optical layout is the absence of transmission optics. Test measurements on liquid and solid samples carried out using the transient grating technique in both transmission and reflection geometry demonstrate the reliability of the setup. PMID:21478973

  10. 重庆市体育高考术科考试成绩与项目设置分析%On Analysis of Score and Setup of Technical Test in College P .E .Entrance Examination in Chongqing

    杨宗友; 李振中

    2015-01-01

    采用文献资料法、专家访谈法、数理统计法对重庆市2011年-2014年体育高考各素质考试项目的测试成绩进行分析,结果显示:①从测试成绩的基本情况来看,男子项目中5米3向折返跑的平均水平最高,但成绩分布的正态性较差;100米跑项目的平均水平最低,但成绩具有相对稳定的离散程度和良好的正态性分布;前抛实心球项目成绩离散程度较大且正态性较差;女子项目中立定跳远的平均水平最高且成绩分布较好,800米跑和5米3向折返跑项目成绩分布的正态性较差.②从各素质考试项目间相关性来看,立定跳远项目和100米项目具有较大的负相关性,速度和力量素质是其它素质的基础.%By means of documentary ,expert interview and mathematical statistics ,the author has analyzed the results of all events in Chongqing's fitness testing from 2011to 2014 .Testing results basically show that three‐way 5‐meter shuttle run is the highest on average of men's events but the results distribution show a less desirable normality .The average of 100‐meter run reaches the lowest ,with a relatively stable degree of dispersion and sound normal distribution .The result of forward throwing of medicine ball show great degree of dispersion and poor normality .Standing long jump is the highest on average of women's e‐vents and the result distribution is satisfactory ,while 800‐meter run and three‐way 5‐meter shuttle run show s poor normality .In terms of the correlation among fitness testing events ,significant negative corre‐lation is found between standing long jump and 100‐meter run .Also ,speed and physical strength lay the foundation of other physical qualities .A good command of the last 4 years' results of college entrance ex‐amination of sports in Chongqing and the intensity of correlation among testing events could provide refer‐ence for its perfection as well as the choice

  11. High-resolution continuous-flow analysis setup for water isotopic measurement from ice cores using laser spectroscopy

    Emanuelsson, B. D.; Baisden, W. T.; Bertler, N. A. N.; Keller, E. D.; Gkinis, V.

    2015-07-01

    Here we present an experimental setup for water stable isotope (δ18O and δD) continuous-flow measurements and provide metrics defining the performance of the setup during a major ice core measurement campaign (Roosevelt Island Climate Evolution; RICE). We also use the metrics to compare alternate systems. Our setup is the first continuous-flow laser spectroscopy system that is using off-axis integrated cavity output spectroscopy (OA-ICOS; analyzer manufactured by Los Gatos Research, LGR) in combination with an evaporation unit to continuously analyze water samples from an ice core. A Water Vapor Isotope Standard Source (WVISS) calibration unit, manufactured by LGR, was modified to (1) enable measurements on several water standards, (2) increase the temporal resolution by reducing the response time and (3) reduce the influence from memory effects. While this setup was designed for the continuous-flow analysis (CFA) of ice cores, it can also continuously analyze other liquid or vapor sources. The custom setups provide a shorter response time (~ 54 and 18 s for 2013 and 2014 setup, respectively) compared to the original WVISS unit (~ 62 s), which is an improvement in measurement resolution. Another improvement compared to the original WVISS is that the custom setups have a reduced memory effect. Stability tests comparing the custom and WVISS setups were performed and Allan deviations (σAllan) were calculated to determine precision at different averaging times. For the custom 2013 setup the precision after integration times of 103 s is 0.060 and 0.070 ‰ for δ18O and δD, respectively. The corresponding σAllan values for the custom 2014 setup are 0.030, 0.060 and 0.043 ‰ for δ18O, δD and δ17O, respectively. For the WVISS setup the precision is 0.035, 0.070 and 0.042 ‰ after 103 s for δ18O, δD and δ17O, respectively. Both the custom setups and WVISS setup are influenced by instrumental drift with δ18O being more drift sensitive than δD. The

  12. Microfabrication of stacks of acoustic matching layers for 15 MHz ultrasonic transducers.

    Manh, Tung; Nguyen, Anh-Tuan Thai; Johansen, Tonni F; Hoff, Lars

    2014-02-01

    This paper presents a novel method used to manufacture stacks of multiple matching layers for 15 MHz piezoelectric ultrasonic transducers, using fabrication technology derived from the MEMS industry. The acoustic matching layers were made on a silicon wafer substrate using micromachining techniques, i.e., lithography and etch, to design silicon and polymer layers with the desired acoustic properties. Two matching layer configurations were tested: a double layer structure consisting of a silicon-polymer composite and polymer and a triple layer structure consisting of silicon, composite, and polymer. The composite is a biphase material of silicon and polymer in 2-2 connectivity. The matching layers were manufactured by anisotropic wet etch of a (110)-oriented Silicon-on-Insulator wafer. The wafer was etched by KOH 40 wt%, to form 83 μm deep and 4.5mm long trenches that were subsequently filled with Spurr's epoxy, which has acoustic impedance 2.4 MRayl. This resulted in a stack of three layers: The silicon substrate, a silicon-polymer composite intermediate layer, and a polymer layer on the top. The stacks were bonded to PZT disks to form acoustic transducers and the acoustic performance of the fabricated transducers was tested in a pulse-echo setup, where center frequency, -6 dB relative bandwidth and insertion loss were measured. The transducer with two matching layers was measured to have a relative bandwidth of 70%, two-way insertion loss 18.4 dB and pulse length 196 ns. The transducers with three matching layers had fractional bandwidths from 90% to 93%, two-way insertion loss ranging from 18.3 to 25.4 dB, and pulse lengths 326 and 446 ns. The long pulse lengths of the transducers with three matching layers were attributed to ripple in the passband. PMID:24041498

  13. Wireless Acoustic Measurement System

    Anderson, Paul D.; Dorland, Wade D.; Jolly, Ronald L.

    2007-01-01

    A prototype wireless acoustic measurement system (WAMS) is one of two main subsystems of the Acoustic Prediction/ Measurement Tool, which comprises software, acoustic instrumentation, and electronic hardware combined to afford integrated capabilities for predicting and measuring noise emitted by rocket and jet engines. The other main subsystem is described in the article on page 8. The WAMS includes analog acoustic measurement instrumentation and analog and digital electronic circuitry combined with computer wireless local-area networking to enable (1) measurement of sound-pressure levels at multiple locations in the sound field of an engine under test and (2) recording and processing of the measurement data. At each field location, the measurements are taken by a portable unit, denoted a field station. There are ten field stations, each of which can take two channels of measurements. Each field station is equipped with two instrumentation microphones, a micro- ATX computer, a wireless network adapter, an environmental enclosure, a directional radio antenna, and a battery power supply. The environmental enclosure shields the computer from weather and from extreme acoustically induced vibrations. The power supply is based on a marine-service lead-acid storage battery that has enough capacity to support operation for as long as 10 hours. A desktop computer serves as a control server for the WAMS. The server is connected to a wireless router for communication with the field stations via a wireless local-area network that complies with wireless-network standard 802.11b of the Institute of Electrical and Electronics Engineers. The router and the wireless network adapters are controlled by use of Linux-compatible driver software. The server runs custom Linux software for synchronizing the recording of measurement data in the field stations. The software includes a module that provides an intuitive graphical user interface through which an operator at the control server

  14. In vitro measurement of ambient pressure changes using a realistic clinical setup

    Andersen, Klaus Scheldrup; Jensen, Jørgen Arendt

    2008-01-01

    flexible offering completely arbitrary excitation and data acquisition, fast and accurate ambient pressure control, and precise timing. More importantly, it resembles a realistic clinical setup using a single array transducer for transmit and receive. The standard signal processing steps usually seen for...... 32 cycles cosine tapered pulse with a center frequency of 4 MHz and an acoustic pressure of 485 kPa was used for excitation. 64 elements were used in receive and the RF data was filtered and beamformed before further processing. To compensate for variations in bubble response and to make the...

  15. NESTOR and SADCO in the Mediterranean. Tests of modules of deep underwater optical and acoustical neutrino detectors near Pylos, Greece

    The results of the Soviet-Greek tests of the 10 PMTs deep undersea detector module for NESTOR - optical neutrino telescope near Pylos, Greece are presented. The vertical muon intensity and the angular distribution of muons at 3000-4000 m depths were measured by that module during r/v ''VITYAZ'' cruise in July-91. The effective registration area of the module for vertical muons was evaluated to be close to 400 m. The proposal to construct 10 m NESTOR by the module principle to install a few supermodules or superstrings modules (each superstring consists of 6 modules) is under consideration. (orig.)

  16. Use of {sup 7}Li(p,n) reaction as a neutron source in a PGNAA setup

    Naqvi, A.A. [Department of Physics, King Fahd University of Petroleum and Minerals, Box No. 1815, Dhahran 31261 (Saudi Arabia)]. E-mail: aanaqvi@kfupm.edu.sa; Nagadi, M.M. [Department of Physics, King Fahd University of Petroleum and Minerals, Box No. 1815, Dhahran 31261 (Saudi Arabia)

    2005-03-01

    The performance of a {sup 7}Li(p,n) reaction-based Prompt Gamma Ray Neutron Activation Analysis (PGNAA) setup has been determined for analysis of Portland cement samples using Monte Carlo study. The calculations were carried out for a {sup 7}Li(p,n) reaction-based PGNAA setup with an external moderator similar to the one used in a previous 2.8 MeV neutrons-based PGNAA setup. The optimum values of geometry parameters of the {sup 7}Li(p,n) reaction-based setup are different from those of the 2.8 MeV neutrons-based setup resulting in better performance of the {sup 7}Li(p,n) reaction-based setup. The prompt {gamma}-ray yield from the {sup 7}Li(p,n) reaction-based setup is 60-70% higher than that from the 2.8 MeV neutrons-based setup. Although the performances of the {sup 7}Li(p,n) reaction-based setup is comparable with that of a previously studied {sup 3}H(p,n) reaction-based setup, yet performance of the {sup 7}Li(p,n) reaction-based setup is superior to that of the {sup 3}H(p,n) reaction-based setup because it has less radiation hazard due to utilization of non-radioactive neutron producing target. This study has provided a theoretical base for experimental test of a {sup 7}Li(p,n) reaction-based PGNAA setup.

  17. Laser-Doppler-Velocimetry on the basis of frequency selective absorption: set-up and test of a Doppler Gloval Velocimeter; Laser-Doppler-Velocimetry auf der Basis frequenzselektiver Absorption: Aufbau und Einsatz eines Doppler Global Velocimeters

    Roehle, I.

    1999-11-01

    A Doppler Global Velocimeter was set up in the frame of a PhD thesis. This velocimeter is optimized to carry out high accuracy, three component, time averaged planar velocity measurements. The anemometer was successfully applied to wind tunnel and test rig flows, and the measurement accuracy was investigated. A volumetric data-set of the flow field inside an industrial combustion chamber was measured. This data field contained about 400.000 vectors. DGV measurements in the intake of a jet engine model were carried out applying a fibre bundle boroskope. The flow structure of the wake of a car model in a wind tunnel was investigated. The measurement accuracy of the DGV-System is {+-}0.5 m/s when operated under ideal conditions. This study can serve as a basis to evaluate the use of DGV for aerodynamic development experiments. (orig.) [German] Im Rahmen der Dissertation wurde ein auf hohe Messgenauigkeit optimiertes DGV-Geraet fuer zeitlich gemittelte Drei-Komponenten-Geschwindigkeitsmessungen entwickelt und gebaut, an Laborstroemungen, an Teststaenden und an Windkanaelen erfolgreich eingesetzt und das Potential der Messtechnik, insbesondere im Hinblick auf Messgenauigkeit, untersucht. Im Fall einer industriellen Brennkammer konnte ein Volumen-Datensatz des Stroemungsfeldes erstellt werden, dessen Umfang bei ca. 400.000 Vektoren lag. Es wurden DGV-Messungen mittels eines flexiblen Endoskops auf Basis eines Faserbuendels durchgefuehrt und damit die Stroemung in einem Flugzeugeinlauf vermessen. Es wurden DGV-Messungen im Nachlauf eines PKW-Modells in einem Windkanal durchgefuehrt. Die Messgenauigkeit des erstellten DGV-Systems betraegt unter Idealbedingungen {+-}0,5 m/s. Durch die Arbeit wurde eine Basis zur Beurteilung des Nutzens der DGV-Technik fuer aerodynamische Entwicklungsarbeiten geschaffen. (orig.)

  18. Transportable setup for amplifier phase fidelity measurements

    Tröbs, M.; Bogan, C.; Barke, S.; Kühn, G.; Reiche, J.; Heinzel, G.; Danzmann, K.

    2015-05-01

    One possible laser source for the Laser Interferometer Space Antenna (LISA) consists of an Ytterbium-doped fiber amplifier originally developed for inter-satellite communication, seeded by the laser used for the technology demonstrator mission LISA Pathfinder. LISA needs to transmit clock information between its three spacecraft to correct for phase noise between the clocks on the individual spacecraft. For this purpose phase modulation sidebands at GHz frequencies will be imprinted on the laser beams between spacecraft. Differential phase noise between the carrier and a sideband introduced within the optical chain must be very low. We report on a transportable setup to measure the phase fidelity of optical amplifiers.

  19. Laboratory setup for temperature and humidity measurements

    Eimre, Kristjan

    2015-01-01

    In active particle detectors, the temperature and humidity conditions must be under constant monitoring and control, as even small deviations from the norm cause changes to detector characteristics and result in a loss of precision. To monitor the temperature and humidity, different kinds of sensors are used, which must be calibrated beforehand to ensure their accuracy. To calibrate the large number of sensors that are needed for the particle detectors and other laboratory work, a calibration system is needed. The purpose of the current work was to develop a laboratory setup for temperature and humidity sensor measurements and calibration.

  20. Evaluation of the acoustic and non-acoustic properties of sound absorbing materials using a three-microphone impedance tube

    Doutres, Olivier; Atalla, Noureddine; Panneton, Raymond; 10.1016/j.apacoust.2010.01.007

    2010-01-01

    This paper presents a straightforward application of an indirect method based on a three-microphone impedance tube setup to determine the non-acoustic properties of a sound absorbing porous material. First, a three-microphone impedance tube technique is used to measure some acoustic properties of the material (i.e., sound absorption coefficient, sound transmission loss, effective density and effective bulk modulus) regarded here as an equivalent fluid. Second, an indirect characterization allows one to extract its non-acoustic properties (i.e., static airflow resistivity, tortuosity, viscous and thermal characteristic lengths) from the measured effective properties and the material open porosity. The procedure is applied to four different sound absorbing materials and results of the characterization are compared with existing direct and inverse methods. Predictions of the acoustic behavior using an equivalent fluid model and the found non-acoustic properties are in good agreement with impedance tube measureme...

  1. ELECTRODYNAMIC LOUDSPEAKER-DRIVEN ACOUSTIC COMPRESSOR

    Martin Šoltés; Milan Červenka

    2015-01-01

    An acoustic compressor is  built  using the acoustic resonator which shape was optimized for a maximum acoustic pressure amplitude and a low-cost compression driver.  Acoustic compressor is built  by installing  a suction port in the resonator wall where the standing wave has its pressure node and a delivery port with a valve in the resonator wall where the standing wave has its pressure anti-node. Different reeds, serving  as delivery valves, are tested and their performance is investigated....

  2. Portable acoustic myography

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

    2013-01-01

    to register at sufficient sampling speed. With modern amplifiers and digital sound recording this has changed, and such assessment during movement outside a laboratory setting may be possible. Our aim was to develop a setup for muscle-sound assessment, which could be reliably applied in any local...... with the possibility of being applied in most clinical, sports, and home settings. Muscle sound gives a representation of the work of each muscle group during a complex movement, illustrated here by a step test, which revealed both concentric and eccentric activity. The method in the presented new...

  3. A versatile and reconfigurable setup for all-terahertz time-resolved pump-probe spectroscopy

    Elezzabi, A. Y.; Maraghechi, P.

    2012-05-01

    A versatile optical setup for all-terahertz (THz) time resolved pump-probe spectroscopy was designed and tested. By utilizing a dual THz pulse generator emitter module, independent and synchronized THz radiation pump and probe pulses were produced, thus eliminating the need for THz beam splitters and the limitations associated with their implementation. The current THz setup allows for precise control of the electric fields splitting ratio between the THz radiation pump and probe pulses, as well as in-phase, out-of-phase, and polarization dependent pump-probe spectroscopy. Since the present THz pump-probe setup does not require specialized THz radiation optical components, such as phase shifters, polarization rotators, or wide bandwidth beam splitters, it can be easily implemented with minimal alterations to a conventional THz time domain spectroscopy system. The present setup is valuable for studying the time dynamics of THz coherent phenomena in solid-state, chemical, and biological systems.

  4. Recreating Riser Slugging Flow Based on an Economic Lab-sized Setup

    Hansen, Lasse; Pedersen, Simon; Yang, Zhenyu;

    2013-01-01

    As a kind of periodic phenomenon, the slugging flow in the offshore oil & gas production addresses a lot of attentions, due to its limitation of production rate, periodic overload processing facilities, and even direct cause of emergent shutdown. This work studies the emulation of the riser...... slugging flow in the offshore oil & gas production, by constructing an economical lab-sized setup in the university campus. Firstly, the construction and used components for the lab setup are illustrated; then, the constructed setup is validated by checking the consistency with some existing typical riser...... slug model, besides extensive experimental tests. The theoretical analysis and experimental results show that this simple setup can recreate the key features of slugging flow phenomenon reasonably precise, and it serves as a good platform for further slug control study....

  5. Acoustic hemostasis

    Crum, L.; Andrew, M.; Bailey, M.; Beach, K.; Brayman, A.; Curra, F.; Kaczkowski, P.; Kargl, S.; Martin, R.; Vaezy, S.

    2003-04-01

    Over the past several years, the Center for Industrial and Medical Ultrasound (CIMU) at the Applied Physics Laboratory in the University of Washington has undertaken a broad research program in the general area of High Intensity Focused Ultrasound (HIFU). Our principal emphasis has been on the use of HIFU to induce hemostasis; in particular, CIMU has sought to develop a small, lightweight, portable device that would use ultrasound for both imaging and therapy. Such a technology is needed because nearly 50% of combat casualty mortality results from exsanguinations, or uncontrolled bleeding. A similar percentage occurs for civilian death due to trauma. In this general review, a presentation of the general problem will be given, as well as our recent approaches to the development of an image-guided, transcutaneous, acoustic hemostasis device. [Work supported in part by the USAMRMC, ONR and the NIH.

  6. Acoustic resonance for nonmetallic mine detection

    Kercel, S.W.

    1998-04-01

    The feasibility of acoustic resonance for detection of plastic mines was investigated by researchers at the Oak Ridge National Laboratory`s Instrumentation and Controls Division under an internally funded program. The data reported in this paper suggest that acoustic resonance is not a practical method for mine detection. Representative small plastic anti-personnel mines were tested, and were found to not exhibit detectable acoustic resonances. Also, non-metal objects known to have strong acoustic resonances were tested with a variety of excitation techniques, and no practical non-contact method of exciting a consistently detectable resonance in a buried object was discovered. Some of the experimental data developed in this work may be useful to other researchers seeking a method to detect buried plastic mines. A number of excitation methods and their pitfalls are discussed. Excitation methods that were investigated include swept acoustic, chopped acoustic, wavelet acoustic, and mechanical shaking. Under very contrived conditions, a weak response that could be attributed to acoustic resonance was observed, but it does not appear to be practical as a mine detection feature. Transfer properties of soil were investigated. Impulse responses of several representative plastic mines were investigated. Acoustic leakage coupling, and its implications as a disruptive mechanism were investigated.

  7. Acoustic telemetry.

    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.

  8. Acoustic Neuroma Educational Video

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

  9. Use of acoustic vortices in acoustic levitation

    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......, 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...

  10. 挪威海格纳斯潜艇水声试验场测量设施分析%Analysis of Facilities of Norwegian Acoustic Testing Field in Heggemes

    刘兴章; 陈涛

    2011-01-01

    利用水声试验场对潜艇的水下辐射噪声进行测量和分析,是先进国家改善潜艇安静性的重要方法.位于挪威卑尔根附近的海格纳斯潜艇水声试验场,是德国、荷兰、丹麦、挪威等北约国家最重要的潜艇水声检测机构.本文介绍了该潜艇水声试验场的选址特点和主要测量设施,分析峡湾水域建设潜艇水声试验的利弊,分析航行试验场和静态试验场对水声试验场建设的不同作用,为我国水声试验场的建设提供参照.%Testing of underwater radiation noise of submarines using acoustic testing field is one of the important measures for improving the submarine' s silence in some developed countries. The Norwegian acoustic testing field in Heggernes is the most important testing field for measuring underwater noise of submarines of the members of NATO such as Germany, Holland, Demark, Norway and so on. In this paper, the characters of location and main facilities of the testing field are introduced. The advantages and disadvantages of the testing field construction in bay area are analyzed. Roles of the static testing field and the dynamic ranging to the testing field construction are studied. This discussion may be helpful for construction of acoustic testing field in our country.

  11. Cryogenic setup for trapped ion quantum computing

    Brandl, M F; Postler, L; Nolf, A; Lakhmanskiy, K; Paiva, R R; Möller, S; Daniilidis, N; Häffner, H; Kaushal, V; Ruster, T; Warschburger, C; Kaufmann, H; Poschinger, U G; Schmidt-Kaler, F; Schindler, P; Monz, T; Blatt, R

    2016-01-01

    We report on the design of a cryogenic setup for trapped ion quantum computing containing a segmented surface electrode trap. The heat shield of our cryostat is designed to attenuate alternating magnetic field noise, resulting in 120~dB reduction of 50~Hz noise along the magnetic field axis. We combine this efficient magnetic shielding with high optical access required for single ion addressing as well as for efficient state detection by placing two lenses each with numerical aperture 0.23 inside the inner heat shield. The cryostat design incorporates vibration isolation to avoid decoherence of optical qubits due to the motion of the cryostat. We measure vibrations of the cryostat of less than $\\pm$20~nm over 2~s. In addition to the cryogenic apparatus, we describe the setup required for an operation with $^{\\mathrm{40}}$Ca$^{\\mathrm{+}}$ and $^{\\mathrm{88}}$Sr$^{\\mathrm{+}}$ ions. The instability of the laser manipulating the optical qubits in $^{\\mathrm{40}}$Ca$^{\\mathrm{+}}$ is characterized yielding a min...

  12. Acoustic dispersive prism

    Hussein Esfahlani; Sami Karkar; Herve Lissek; Mosig, Juan R.

    2016-01-01

    The optical dispersive prism is a well-studied element, which allows separating white light into its constituent spectral colors, and stands in nature as water droplets. In analogy to this definition, the acoustic dispersive prism should be an acoustic device with capability of splitting a broadband acoustic wave into its constituent Fourier components. However, due to the acoustical nature of materials as well as the design and fabrication difficulties, there is neither any natural acoustic ...

  13. STRAIN LOCALIZATION PECULIARITIES AND DISTRIBUTION OF ACOUSTIC EMISSION SOURCES IN ROCK SAMPLES TESTED BY UNIAXIAL COMPRESSION AND EXPOSED TO ELECTRIC PULSES

    V. A. Mubassarova

    2015-09-01

    Full Text Available Results of uniaxial compression tests of rock samples in electromagnetic fields are presented. The experiments were performed in the Laboratory of Basic Physics of Strength, Institute of Continuous Media Mechanics, Ural Branch of RAS (ICMM. Deformation of samples was studied, and acoustic emission (AE signals were recorded. During the tests, loads varied by stages. Specimens of granite from the Kainda deposit in Kyrgyzstan (similar to samples tested at the Research Station of RAS, hereafter RS RAS were subject to electric pulses at specified levels of compression load. The electric pulses supply was galvanic; two graphite electrodes were fixed at opposite sides of each specimen. The multichannel Amsy-5 Vallen System was used to record AE signals in the six-channel mode, which provided for determination of spatial locations of AE sources. Strain of the specimens was studied with application of original methods of strain computation based on analyses of optical images of deformed specimen surfaces in LaVISION Strain Master System.Acoustic emission experiment data were interpreted on the basis of analyses of the AE activity in time, i.e. the number of AE events per second, and analyses of signals’ energy and AE sources’ locations, i.e. defects.The experiment was conducted at ICMM with the use of the set of equipment with advanced diagnostic capabilities (as compared to earlier experiments described in [Zakupin et al., 2006a, 2006b; Bogomolov et al., 2004]. It can provide new information on properties of acoustic emission and deformation responses of loaded rock specimens to external electric pulses.The research task also included verification of reproducibility of the effect (AE activity when fracturing rates responded to electrical pulses, which was revealed earlier in studies conducted at RS RAS. In terms of the principle of randomization, such verification is methodologically significant as new effects, i.e. physical laws, can be considered

  14. Simultaneous measurement of acoustic pressure and temperature in the HIFU fields using all-silica fiber optic Fabry-Perot hydorophone

    Wang, Dai-Hua; Zeng, Lu-Yu; Jia, Ping-Gang; Liu, Lei; Jiang, Xin-Yin

    2014-11-01

    Accurately measuring the acoustic pressure distributions and the size of the focal regions of high-intensity focused ultrasound (HIFU) fields, as well as the temperature induced by the HIFUs, are significant for ensuring the efficiency and safety of treatments. In our previous work, a tip-sensitive all-silica fiber-optic Fabry-Perot (TAFOFP) ultrasonic hydrophone for measuring HIFU fields is developed. In this paper, we explore the possibility that utilizing the TAFOFP ultrasonic hydrophone to simultaneously measure the acoustic pressure of HIFU fields and the induced temperature. The TAFOFP ultrasonic hydrophone for simultaneously measuring the acoustic pressure and temperature is developed and the experiment setup for measuring the HIFU fields based on the developed TAFOFP ultrasonic hydrophone is established. The developed TAFOFP ultrasonic hydrophone is experimentally tested in the degassed water and tissue phantom to verify the possibility of simultaneously measuring the acoustic pressure and temperature. Experimental results show that the sensing system can simultaneously measure the acoustic pressure and temperature.

  15. ALBERTA - HEC test beam set-up in June 1999

    Vinter, M.

    1999-01-01

    Photo1 - HEC 2 (rear) being set up in the "clean" room. Photo2 - HEC 2 (rear) being craned onto rotating C. Photo3 - HEC 2 (rear) being rotated. Photo4 - A now well rotated HEC 2 (rear) is being craned off the C. Photo5 - HEC 2 (rear) installed in the cryostat. Photo6 - Part of the basic frame (the frame that sits in the very bottom of the cryostat). Photo7 - Part of the basic frame (one of the two frames which the 3 calorimeter modules sit on). Photo8 - The marriage frame.

  16. Setup of IN VIVO Breast Cancer Models for Nanodrug Testing

    Schifter, Søren

    Synthetic lethality is a promising concept for future cancer treatment and using siRNAs as the synthetic lethal drug component allows for also covering the space considered as non-druggable by conventional small molecule drugs. Systemic administration of naked siRNA, however, does not result in s...

  17. Computational and experimental techniques for coupled acoustic/structure interactions.

    Sumali, Anton Hartono; Pierson, Kendall Hugh; Walsh, Timothy Francis; Dohner, Jeffrey Lynn; Reese, Garth M.; Day, David Minot

    2004-01-01

    This report documents the results obtained during a one-year Laboratory Directed Research and Development (LDRD) initiative aimed at investigating coupled structural acoustic interactions by means of algorithm development and experiment. Finite element acoustic formulations have been developed based on fluid velocity potential and fluid displacement. Domain decomposition and diagonal scaling preconditioners were investigated for parallel implementation. A formulation that includes fluid viscosity and that can simulate both pressure and shear waves in fluid was developed. An acoustic wave tube was built, tested, and shown to be an effective means of testing acoustic loading on simple test structures. The tube is capable of creating a semi-infinite acoustic field due to nonreflecting acoustic termination at one end. In addition, a micro-torsional disk was created and tested for the purposes of investigating acoustic shear wave damping in microstructures, and the slip boundary conditions that occur along the wet interface when the Knudsen number becomes sufficiently large.

  18. SU-E-J-22: A Feasibility Study On KV-Based Whole Breast Radiation Patient Setup

    Huang, Q [Rutgers Cancer Institute of New Jersey, New Brunswick, NJ (United States); Zhang, M; Yue, N; Chen, T [Rutgers University, New Brunswick, NJ (United States)

    2015-06-15

    Purpose: In room kilovoltage x-ray (kV) imaging provides higher contrast than Megavoltage (MV) imaging with faster acquisition time compared with on-board cone-beam computed tomography (CBCT), thus improving patient setup accuracy and efficiency. In this study we evaluated the clinical feasibility of utilizing kV imaging for whole breast radiation patient setup. Methods: For six breast cancer patients with whole breast treatment plans using two opposed tangential fields, MV-based patient setup was conducted by aligning patient markers with in room lasers and MV portal images. Beam-eye viewed kV images were acquired using Varian OBI system after the set up process. In house software was developed to transfer MLC blocks information overlaying onto kV images to demonstrate the field shape for verification. KV-based patient digital shift was derived by performing rigid registration between kV image and the digitally reconstructed radiography (DRR) to align the bony structure. This digital shift between kV-based and MV-based setup was defined as setup deviation. Results: Six sets of kV images were acquired for breast patients. The mean setup deviation was 2.3mm, 2.2mm and 1.8mm for anterior-posterior, superior-inferior and left-right direction respectively. The average setup deviation magnitude was 4.3±1.7mm for six patients. Patient with large breast had a larger setup deviation (4.4–6.2mm). There was no strong correlation between MV-based shift and setup deviation. Conclusion: A preliminary clinical workflow for kV-based whole breast radiation setup was established and tested. We observed setup deviation of the magnitude below than 5mm. With the benefit of providing higher contrast and MLC block overlaid on the images for treatment field verification, it is feasible to use kV imaging for breast patient setup.

  19. SU-E-J-22: A Feasibility Study On KV-Based Whole Breast Radiation Patient Setup

    Purpose: In room kilovoltage x-ray (kV) imaging provides higher contrast than Megavoltage (MV) imaging with faster acquisition time compared with on-board cone-beam computed tomography (CBCT), thus improving patient setup accuracy and efficiency. In this study we evaluated the clinical feasibility of utilizing kV imaging for whole breast radiation patient setup. Methods: For six breast cancer patients with whole breast treatment plans using two opposed tangential fields, MV-based patient setup was conducted by aligning patient markers with in room lasers and MV portal images. Beam-eye viewed kV images were acquired using Varian OBI system after the set up process. In house software was developed to transfer MLC blocks information overlaying onto kV images to demonstrate the field shape for verification. KV-based patient digital shift was derived by performing rigid registration between kV image and the digitally reconstructed radiography (DRR) to align the bony structure. This digital shift between kV-based and MV-based setup was defined as setup deviation. Results: Six sets of kV images were acquired for breast patients. The mean setup deviation was 2.3mm, 2.2mm and 1.8mm for anterior-posterior, superior-inferior and left-right direction respectively. The average setup deviation magnitude was 4.3±1.7mm for six patients. Patient with large breast had a larger setup deviation (4.4–6.2mm). There was no strong correlation between MV-based shift and setup deviation. Conclusion: A preliminary clinical workflow for kV-based whole breast radiation setup was established and tested. We observed setup deviation of the magnitude below than 5mm. With the benefit of providing higher contrast and MLC block overlaid on the images for treatment field verification, it is feasible to use kV imaging for breast patient setup

  20. Effect of Perforated Plates on the Acoustics of Annular Combustors

    Gullaud, Elsa; Nicoud, Franck

    2012-01-01

    This paper aims to show the influence of perforated plates on the acoustic modes in aeronautical gas turbine combustion chambers. The analytical model was implemented in a three-dimensional acoustic Helmholtz solver to account for the effect of perforated plates. First, an analytic test case is used to validate the coding in the acoustic solver. Then, a computation of the acoustic modes in an actual industrial chamber is conducted, taking into account the perforated liners. For both cases, a ...

  1. Three-dimensional Ultrathin Planar Lenses by Acoustic Metamaterials

    Li, Yong; Yu, Gaokun; Liang, Bin; Zou, Xinye; Li, Guangyun; Cheng, Su; Cheng, Jianchun

    2014-01-01

    Acoustic lenses find applications in various areas ranging from ultrasound imaging to nondestructive testing. A compact-size and high-efficient planar acoustic lens is crucial to achieving miniaturization and integration, and should have deep implication for the acoustic field. However its realization remains challenging due to the trade-off between high refractive-index and impedance-mismatch. Here we have designed and experimentally realized the first ultrathin planar acoustic lens capable ...

  2. Acoustic emission monitoring of tensile testing of corroded and un-corroded clad aluminum 2024-T3 and characterization of effects of corrosion on AE source events and material tensile properties

    Okafor, A. Chukwujekwu; Natarajan, Shridhar

    2014-02-01

    Corrosion damage affects structural integrity and deteriorates material properties of aluminum alloys in aircraft structures. Acoustic Emission (AE) is an effective nondestructive evaluation (NDE) technique for monitoring such damages and predicting failure in large structures of an aircraft. For successful interpretation of data from AE monitoring, sources of AE and factors affecting it need to be identified. This paper presents results of AE monitoring of tensile testing of corroded and un-corroded clad Aluminum 2024-T3 test specimens, and characterization of the effects of strain-rate and corrosion damage on material tensile properties and AE source events. Effect of corrosion was studied by inducing corrosion in the test specimens by accelerated corrosion testing in a Q-Fog accelerated corrosion chamber for 12 weeks. Eight (8) masked dog-bone shaped specimens were placed in the accelerated corrosion chamber at the beginning of the test. Two (2) dog-bone shaped specimens were removed from the corrosion chamber after exposure time of 3, 6, 9, and 12 weeks respectively, and subjected to tension testing till specimen failure along with AE monitoring, as well as two (2) reference samples not exposed to corrosion. Material tensile properties (yield strength, ultimate tensile strength, toughness, and elongation) obtained from tension test and AE parameters obtained from AE monitoring were analyzed and characterized. AE parameters increase with increase in exposure period of the specimens in the corrosive environment. Aluminum 2024-T3 is an acoustically silent material during tensile deformation without any damage. Acoustic emission events increase with increase of corrosion damage and with increase in strain rate above a certain value. Thus AE is suitable for structural health monitoring of corrosion damage. Ultimate tensile strength, toughness and elongation values decrease with increase of exposure period in corrosion chamber.

  3. Experimental Setup to Characterize Bentonite Hydration Processes

    We present an experimental setup to follow-up the hydration process of a bentonite. Clay samples, of 2 cm x 12 cm x 12 cm, were made and introduced in a Hele-Shaw cell with two PMM windows and two steel frames. In hydration experiments, a fluid enters by an orifice in the frame, located both at the top and the bottom of the cell, to perform hydration in both senses. To get a uniform hydration we place a diffuser near the orifice. Volume influxes in hydration cells are registered in time. The evolution of the developed interface was recorded on a videotape. The video cameras was fixed to a holder so that the vertical direction in the monitor was the same as the direction of the larger extension of the cell. (Author) 6 refs

  4. Improvements of the optical detection setup of COLLAPS

    Sailer, Stefan

    2015-01-01

    In Collinear Laser Spectroscopy of rare isotopes it is crucial to keep the background of the measurements low. Using photomultiplier tubes for those measurements, the dark count rate should be as low as possible and the signal gain high. Therefore, it is important to use the right type of photomultiplier tubes for the purpose of single photon detection with a low signal rate. Thus, I tested several different types of photomultiplier tubes for their dark count rates and noise to signal separation. The results have identified the most suitable type of photomultiplier tubes, but further measuring for verification might be necessary. Therefore, it is very important to keep the photomultiplier tubes shut from light. Exposing the photocathode to light implies life-long damage and increased background for several days. So far, when dismounting one of these photomultiplier tubes from the setup, a big cage around the optical detection setup was covered into black sheets to keep it as dark as possible inside. Still, th...

  5. Prediction of pile set-up in clays and sands

    Increase in pile capacity after initial driving has been well observed in clays and sands over decades. The phenomenon is referred to as pile set-up by geotechnical engineers. More economical pile design may benefit from this time-dependent increase subject to a reliable prediction. Simple empirical relations of the current capacity with the initial capacity and elapse time after driving are available in the literature with different model parameters being suggested for clays and sands, respectively. Nevertheless, appropriateness of the relations and confidence interval of the model parameters are rarely investigated and this hinders the application of these formulae. In this study, a revised single-parameter empirical relation is proposed based on the existing formulae. A comprehensive database from pile field tests data in clayey and sandy ground in the literature is compiled and Bayesian analysis is conducted on both these empirical formulae independently for clays and sands. Bayesian inference allows not only the estimation of the uncertain parameter but also the quantification of the associated uncertainty in the form of probability distribution. This study sheds lights on the confidence interval of the model parameter and it provides designers more reliable prediction of the additional capacity due to pile set-up.

  6. A Demonstration of Underwater Bubble Capture by the Fundamental Acoustic Mode in Spherical Geometry

    Umaporn KONTHARAK

    2008-01-01

    Full Text Available Nowadays, scientific demonstrations have become a crucial part of scientific learning. Acoustic waves are normally demonstrated in air via Kundt’s tube, but a physical demonstration for underwater acoustic waves is still lacking. In this paper, we address one of the aspects by demonstrating a way to acoustically-trap gas bubbles in a spherical, water-filled flask resonating at its first fundamental mode. The theory of acoustic waves in a spherical geometry, particularly the fundamental mode, is reviewed. The full description of the experimental setup is expressed both acoustically and electronically. By using this method, we show that a gas bubble can be stabilized in the middle of a flask at an acoustic frequency of 21.16 kHz, the acoustic fundamental frequency of the flask.

  7. Acoustic Neurinomas

    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.

  8. Acoustic Spatiality

    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.

  9. Springer Handbook of Acoustics

    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...

  10. Acoustically-Induced Electrical Signals

    Brown, S. R.

    2014-12-01

    We have observed electrical signals excited by and moving along with an acoustic pulse propagating in a sandstone sample. Using resonance we are now studying the characteristics of this acousto-electric signal and determining its origin and the controlling physical parameters. Four rock samples with a range of porosities, permeabilities, and mineralogies were chosen: Berea, Boise, and Colton sandstones and Austin Chalk. Pore water salinity was varied from deionized water to sea water. Ag-AgCl electrodes were attached to the sample and were interfaced to a 4-wire electrical resistivity system. Under computer control, the acoustic signals were excited and the electrical response was recorded. We see strong acoustically-induced electrical signals in all samples, with the magnitude of the effect for each rock getting stronger as we move from the 1st to the 3rd harmonics in resonance. Given a particular fluid salinity, each rock has its own distinct sensitivity in the induced electrical effect. For example at the 2nd harmonic, Berea Sandstone produces the largest electrical signal per acoustic power input even though Austin Chalk and Boise Sandstone tend to resonate with much larger amplitudes at the same harmonic. Two effects are potentially responsible for this acoustically-induced electrical response: one the co-seismic seismo-electric effect and the other a strain-induced resistivity change known as the acousto-electric effect. We have designed experimental tests to separate these mechanisms. The tests show that the seismo-electric effect is dominant in our studies. We note that these experiments are in a fluid viscosity dominated seismo-electric regime, leading to a simple interpretation of the signals where the electric potential developed is proportional to the local acceleration of the rock. Toward a test of this theory we have measured the local time-varying acoustic strain in our samples using a laser vibrometer.

  11. PORTABLE ACOUSTIC MONITORING PACKAGE (PAMP)

    John l. Loth; Gary J. Morris; George M. Palmer; Richard Guiler; Deepak Mehra

    2003-07-01

    The 1st generation acoustic monitoring package was designed to detect and analyze weak acoustic signals inside natural gas transmission lines. Besides a microphone it housed a three-inch diameter aerodynamic acoustic signal amplifier to maximize sensitivity to leak induced {Delta}p type signals. The theory and test results of this aerodynamic signal amplifier was described in the master's degree thesis of our Research Assistant Deepak Mehra who is about to graduate. To house such a large three-inch diameter sensor required the use of a steel 300-psi rated 4 inch weld neck flange, which itself weighed already 29 pounds. The completed 1st generation Acoustic Monitoring Package weighed almost 100 pounds. This was too cumbersome to mount in the field, on an access port at a pipeline shut-off valve. Therefore a 2nd generation and truly Portable Acoustic Monitor was built. It incorporated a fully self-contained {Delta}p type signal sensor, rated for line pressures up to 1000 psi with a base weight of only 6 pounds. This is the Rosemont Inc. Model 3051CD-Range 0, software driven sensor, which is believed to have industries best total performance. Its most sensitive unit was purchased with a {Delta}p range from 0 to 3 inch water. This resulted in the herein described 2nd generation: Portable Acoustic Monitoring Package (PAMP) for pipelines up to 1000 psi. Its 32-pound total weight includes an 18-volt battery. Together with a 3 pound laptop with its 4-channel data acquisition card, completes the equipment needed for field acoustic monitoring of natural gas transmission pipelines.

  12. Safety in acoustic emission testing

    The human cost of accidents - the loss of family members and friends, and the impairment of life through injuries - makes prevention a very high priority in our society. Especially in the more industrialized countries, where high levels of personal comfort and security are the norm, resources are available to develop safety-enhancing technologies, cultures and management techniques. Thus, safety programs have become a well-established part of the industrial workplace. (author)

  13. SES and Acoustics at GSFC

    Hogue, Patrick

    2008-01-01

    This paper presents air and surface cleanliness characterization of the acoustics test facility and large (SES) thermal vacuum chamber at Goddard Space flight Center in Greenbelt, MD during the New Horizons Pluto probe program. It is shown that slow back-fill of the SES chamber is necessary to prevent excessive particle redistribution.

  14. Full scale testing of wind turbine blade to failure - flapwise loading

    Jørgensen, E.R.; Borum, Kaj Kvisgaard; McGugan, Malcolm; Thomsen, C.L.; Jensen, Find Mølholt; Debel, C.P.; Sørensen, Bent F.

    2004-01-01

    A 25m wind turbine blade was tested to failure when subjected to a flapwise load. With the test setup, it was possible to test the blade to failure at three different locations. The objective of these tests is to learn about how a wind turbine bladefails when exposed to a large flapwise load and...... how failures propagate. The report shows also results from ultrasonic scan of the surface of the blade and it is seen to be very useful for the detection of defects, especially in the layer between the skinlaminate and the load carrying main spar. Acoustic emission was successfully used as sensor for...

  15. The use of adaptive radiation therapy to reduce setup error: a prospective clinical study

    Purpose: Adaptive Radiation Therapy (ART) is a closed-loop feedback process where each patients treatment is adaptively optimized according to the individual variation information measured during the course of treatment. The process aims to maximize the benefits of treatment for the individual patient. A prospective study is currently being conducted to test the feasibility and effectiveness of ART for clinical use. The present study is limited to compensating the effects of systematic setup error. Methods and Materials: The study includes 20 patients treated on a linear accelerator equipped with a computer controlled multileaf collimator (MLC) and a electronic portal imaging device (EPID). Alpha cradles are used to immobilize those patients treated for disease in the thoracic and abdominal regions, and thermal plastic masks for the head and neck. Portal images are acquired daily. Setup error of each treatment field is quantified off-line every day. As determined from an earlier retrospective study of different clinical sites, the measured setup variation from the first 4 to 9 days, are used to estimate systematic setup error and the standard deviation of random setup error for each field. Setup adjustment is made if estimated systematic setup error of the treatment field was larger than or equal to 2 mm. Instead of the conventional approach of repositioning the patient, setup correction is implemented by reshaping MLC to compensate for the estimated systematic error. The entire process from analysis of portal images to the implementation of the modified MLC field is performed via computer network. Systematic and random setup errors of the treatment after adjustment are compared with those prior to adjustment. Finally, the frequency distributions of block overlap cumulated throughout the treatment course are evaluated. Results: Sixty-seven percent of all treatment fields were reshaped to compensate for the estimated systematic errors. At the time of this writing

  16. Acoustic source for generating an acoustic beam

    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.

  17. 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

    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.

  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

    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. My 65 years in acoustics

    Beranek, Leo L.

    2001-05-01

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

  20. Acoustic clouds: standing sound waves around a black hole analogue

    Benone, Carolina L; Herdeiro, Carlos; Radu, Eugen

    2014-01-01

    Under certain conditions sound waves in fluids experience an acoustic horizon with analogue properties to those of a black hole event horizon. In particular, a draining bathtub-like model can give rise to a rotating acoustic horizon and hence a rotating black hole (acoustic) analogue. We show that sound waves, when enclosed in a cylindrical cavity, can form stationary waves around such rotating acoustic black holes. These acoustic perturbations display similar properties to the scalar clouds that have been studied around Kerr and Kerr-Newman black holes; thus they are dubbed acoustic clouds. We make the comparison between scalar clouds around Kerr black holes and acoustic clouds around the draining bathtub explicit by studying also the properties of scalar clouds around Kerr black holes enclosed in a cavity. Acoustic clouds suggest the possibility of testing, experimentally, the existence and properties of black hole clouds, using analog models.

  1. Time Reversal Processing in Acoustic Emission Monitoring

    Převorovský, Zdeněk; Krofta, Josef; Farová, Zuzana; Chlada, Milan; Dos Santos, S.

    Singapore, 2013. s. 65-65. [International Congress on ULTRASONICS. 02.05.2013-05.05.2013, Singapore] Institutional support: RVO:61388998 Keywords : time reveresal * acoustic emission * deconvolution * source identification Subject RIV: JS - Reliability ; Quality Management, Testing

  2. Neutron lifetime measurement on setups with gravitational trap

    Serebrov, A. P., E-mail: serebrov@pnpi.spb.ru; Fomin, A. K.; Kharitonov, A. G.; Varlamov, V. E.; Kolomenskiy, E. A.; Krasnoshchekova, I. A.; Chechkin, A. V. [National Research Centre “Kurchatov Institute”, Petersburg Nuclear Physics Institute (Russian Federation)

    2016-01-15

    Currently, the best accuracy of neutron lifetime measurements has been attained in the experiment with a gravitational trap for ultracold neutrons (UCNs), performed at the Petersburg Nuclear Physics Institute (PNPI); the measured lifetime was 878.5 ± 0.8 s. A new setup with a big gravitational trap has been designed to continue the methods and approaches used in the previous experiment. It is planned to reduce the measurement error to 0.2 s, i.e., improve the existing accuracy by a factor of 4. The spectrometer was designed at PNPI and installed on the PF2/MAM beam at the Institute Laue–Langevin. Test experiments have been performed.

  3. The new cold neutron tomography set-up at SINQ

    Baechler, S; Cauwels, P; Dierick, M; Jolie, J; Materna, T; Mondelaers, W

    2002-01-01

    A new cold neutron tomography set-up is operational at the neutron spallation source SINQ of the Paul Scherrer Institute (PSI) in Villigen, Switzerland. The detection system is based on a sup 6 LiF/ZnS:Ag conversion screen and a CCD camera. Several tests have been carried out to characterize the quality of the tomography system, such as homogeneity, reproducibility, L/D-ratio and spatial resolution. The high flux and the good efficiency of the detector lead to very short exposure times. Thus, a typical set of tomography scans can be performed in only 20 min. Then, 3D computed tomography objects were calculated using the filtered back-projection reconstruction method. Initial results of various samples show that cold neutron tomography can be a useful tool for industry, geology and dentistry. Furthermore, suitable applications can be found in the field of archaeology.

  4. The new cold neutron tomography set-up at SINQ

    A new cold neutron tomography set-up is operational at the neutron spallation source SINQ of the Paul Scherrer Institute (PSI) in Villigen, Switzerland. The detection system is based on a 6LiF/ZnS:Ag conversion screen and a CCD camera. Several tests have been carried out to characterize the quality of the tomography system, such as homogeneity, reproducibility, L/D-ratio and spatial resolution. The high flux and the good efficiency of the detector lead to very short exposure times. Thus, a typical set of tomography scans can be performed in only 20 min. Then, 3D computed tomography objects were calculated using the filtered back-projection reconstruction method. Initial results of various samples show that cold neutron tomography can be a useful tool for industry, geology and dentistry. Furthermore, suitable applications can be found in the field of archaeology

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

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

    2005-01-01

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

  6. Atlantic Herring Acoustic Surveys

    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...

  7. Acoustic Neuroma Educational Video

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

  8. Acoustic Neuroma Educational Video

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

  9. Acoustic Neuroma Educational Video

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

  10. Acoustic Neuroma Educational Video

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

  11. Acoustic Neuroma Educational Video

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

  12. Acoustic Neuroma Educational Video

    Full Text Available ... ANA Staff Medical Advisory Board News ANA Annual Reports Acoustic Neuroma Legacy Society Programs & Services Join/Renew ... ANA Staff Medical Advisory Board News ANA Annual Reports Acoustic Neuroma Legacy Society Programs & Services Search ANAUSA. ...

  13. Cystic acoustic neuromas

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

    2002-01-01

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

  14. Ultrafast velocity-mapping in microfluidic setups

    NMR in combination with designated rf coils has proven to be a powerful tool for the investigation of microfluidic setups, e.g. microreactors, micromixers and fluid drops, since it has the potential to reveal both spectroscopic, spatial and velocity information non-invasively. Despite the high spatial resolution NMR offers, the temporal resolution of NMR imaging and velocity mapping experiments in microfluidics has been low so far, because the application of ultrafast NMR velocity mapping methods to microfluidics has failed. These methods are based on multi-echo generation give rise to problems concerning magnetic field inhomogeneities (EPI), rf field inhomogeneities (PGSE-RARE) and velocity/acceleration limitations (EPI and PGSE-RARE). In this work, we exploit the advantages of the FLIESSEN (Flow Imaging Employing a Single Shot ENcoding) pulse sequence, a new ultrafast RARE-based imaging and velocity mapping method. An adjusted phase encoding strategy and a frequent update of velocity encoding during the multi-echo train makes FLIESSEN highly resilient to field inhomogeneities and velocity/acceleration effects. The performance of this technique is demonstrated on acetone flow in a microstructured phantom. Using FLIESSEN and a surface rf coil, high-fidelity 2D velocity maps were acquired within seconds.

  15. Compact electrically detected magnetic resonance setup

    Electrically detected magnetic resonance (EDMR) is a commonly used technique for the study of spin-dependent transport processes in semiconductor materials and electro-optical devices. Here, we present the design and implementation of a compact setup to measure EDMR, which is based on a commercially available benchtop electron paramagnetic resonance (EPR) spectrometer. The electrical detection part uses mostly off-the-shelf electrical components and is thus highly customizable. We present a characterization and calibration procedure for the instrument that allowed us to quantitatively reproduce results obtained on a silicon-based reference sample with a “large-scale” state-of-the-art instrument. This shows that EDMR can be used in novel contexts relevant for semiconductor device fabrication like clean room environments and even glove boxes. As an application example, we present data on a class of environment-sensitive objects new to EDMR, semiconducting organic microcrystals, and discuss similarities and differences to data obtained for thin-film devices of the same molecule

  16. Strength Restoration of Cracked Sandstone and Coal under a Uniaxial Compression Test and Correlated Damage Source Location Based on Acoustic Emissions

    Feng, Xiaowei; Zhang, Nong; Zheng, Xigui; Pan, Dongjiang

    2015-01-01

    Underground rock masses have shown a general trend of natural balance over billions of years of ground movement. Nonetheless, man-made underground constructions disturb this balance and cause rock stability failure. Fractured rock masses are frequently encountered in underground constructions, and this study aims to restore the strength of rock masses that have experienced considerable fracturing under uniaxial compression. Coal and sandstone from a deep-buried coal mine were chosen as experimental subjects; they were crushed by uniaxial compression and then carefully restored by a chemical adhesive called MEYCO 364 with an innovative self-made device. Finally, the restored specimens were crushed once again by uniaxial compression. Axial stress, axial strain, circumferential strain, and volumetric strain data for the entire process were fully captured and are discussed here. An acoustic emission (AE) testing system was adopted to cooperate with the uniaxial compression system to provide better definitions for crack closure thresholds, crack initiation thresholds, crack damage thresholds, and three-dimensional damage source locations in intact and restored specimens. Several remarkable findings were obtained. The restoration effects of coal are considerably better than those of sandstone because the strength recovery coefficient of the former is 1.20, whereas that of the latter is 0.33, which indicates that MEYCO 364 is particularly valid for fractured rocks whose initial intact peak stress is less than that of MEYCO 364. Secondary cracked traces of restored sandstone almost follow the cracked traces of the initial intact sandstone, and the final failure is mainly caused by decoupling between the adhesive and the rock mass. However, cracked traces of restored coal only partially follow the traces of intact coal, with the final failure of the restored coal being caused by both bonding interface decoupling and self-breakage in coal. Three-dimensional damage source

  17. Strength Restoration of Cracked Sandstone and Coal under a Uniaxial Compression Test and Correlated Damage Source Location Based on Acoustic Emissions.

    Xiaowei Feng

    Full Text Available Underground rock masses have shown a general trend of natural balance over billions of years of ground movement. Nonetheless, man-made underground constructions disturb this balance and cause rock stability failure. Fractured rock masses are frequently encountered in underground constructions, and this study aims to restore the strength of rock masses that have experienced considerable fracturing under uniaxial compression. Coal and sandstone from a deep-buried coal mine were chosen as experimental subjects; they were crushed by uniaxial compression and then carefully restored by a chemical adhesive called MEYCO 364 with an innovative self-made device. Finally, the restored specimens were crushed once again by uniaxial compression. Axial stress, axial strain, circumferential strain, and volumetric strain data for the entire process were fully captured and are discussed here. An acoustic emission (AE testing system was adopted to cooperate with the uniaxial compression system to provide better definitions for crack closure thresholds, crack initiation thresholds, crack damage thresholds, and three-dimensional damage source locations in intact and restored specimens. Several remarkable findings were obtained. The restoration effects of coal are considerably better than those of sandstone because the strength recovery coefficient of the former is 1.20, whereas that of the latter is 0.33, which indicates that MEYCO 364 is particularly valid for fractured rocks whose initial intact peak stress is less than that of MEYCO 364. Secondary cracked traces of restored sandstone almost follow the cracked traces of the initial intact sandstone, and the final failure is mainly caused by decoupling between the adhesive and the rock mass. However, cracked traces of restored coal only partially follow the traces of intact coal, with the final failure of the restored coal being caused by both bonding interface decoupling and self-breakage in coal. Three

  18. Liquid rocket combustion chamber acoustic characterization

    Cândido Magno de Souza

    2010-09-01

    Full Text Available Over the last 40 years, many solid and liquid rocket motors have experienced combustion instabilities. Among other causes, there is the interaction of acoustic modes with the combustion and/or fluid dynamic processes inside the combustion chamber. Studies have been showing that, even if less than 1% of the available energy is diverted to an acoustic mode, combustion instability can be generated. On one hand, this instability can lead to ballistic pressure changes, couple with other propulsion systems such as guidance or thrust vector control, and in the worst case, cause motor structural failure. In this case, measures, applying acoustic techniques, must be taken to correct/minimize these influences on the combustion. The combustion chamber acoustic behavior in operating conditions can be estimated by considering its behavior in room conditions. In this way, acoustic tests can be easily performed, thus identifying the cavity modes. This paper describes the procedures to characterize the acoustic behavior in the inner cavity of four different configurations of a combustion chamber. Simple analytical models are used to calculate the acoustic resonance frequencies and these results are compared with acoustic natural frequencies measured at room conditions. Some comments about the measurement procedures are done, as well as the next steps for the continuity of this research. The analytical and experimental procedures results showed good agreement. However, limitations on high frequency band as well as in the identification of specific kinds of modes indicate that numerical methods able to model the real cavity geometry and an acoustic experimental modal analysis may be necessary for a more complete analysis. Future works shall also consider the presence of passive acoustic devices such as baffles and resonators capable of introducing damping and avoiding or limiting acoustic instabilities.

  19. Acoustic Mechanical Feedthroughs

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

    2013-01-01

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

  20. VIBRO-ACOUSTIC STUDY OF LIGHTWEIGHT COMPONENTS BASED ON A NEW EXPERIMENTAL SETUP

    Vivolo, Marianna; PLUYMERS, Bert; Vandepitte, Dirk; Desmet, Wim

    2011-01-01

    In automotive, aerospace, building and many other industrial applications the increasing usage of lightweight material components pushes research towards new experimental and numerical methods to accurately determine and predict the Noise Vibration and Harshness (NVH) perform-ance of innovative lightweight solutions. The inherent high stiffness to mass ratio of lightweight structures provides huge benefits in material and energy savings, but often has a detrimental effect on the structure’s N...

  1. Direct estimation wave setup as a medium level in swash

    Díaz Sánchez, Roberto; López Gutiérrez, José Santos; Lechuga, Antonio; Negro Valdecantos, Vicente; Esteban, M. Dolores

    2013-01-01

    The extreme runup is a key parameter for a shore risk analysis in which the accurate and quantitative estimation of the upper limit reached by waves is essential. Runup can be better approximated by splitting the setup and swash semi-amplitude contributions. In an experimental study recording setup becomes difficult due to infragravity motions within the surf zone, hence, it would be desirable to measure the setup with available methodologies and devices. In this research, an analysis is made...

  2. Visualizing acoustical beats with a smartphones

    Giménez, Marcos H; Castro-Palacio, Juan C; Gómez-Tejedor, José A; Monsoriu, Juan A

    2016-01-01

    In this work, a new Physics laboratory experiment on Acoustics beats is presented. We have designed a simple experimental setup to study superposition of sound waves of slightly different frequencies (acoustic beat). The microphone of a smartphone is used to capture the sound waves emitted by two equidistant speakers from the mobile which are at the same time connected to two AC generators. The smartphone is used as a measuring instrument. By means of a simple and free AndroidTM application, the sound level (in dB) as a function of time is measured and exported to a .csv format file. Applying common graphing analysis and a fitting procedure, the frequency of the beat is obtained. The beat frequencies as obtained from the smartphone data are compared with the difference of the frequencies set at the AC generator. A very good agreement is obtained being the percentage discrepancies within 1 %.

  3. Boundary acquisition for setup of numerical simulation

    Diegert, C. [Sandia National Lab., Albuquerque, NM (United States)

    1997-12-31

    The author presents a work flow diagram that includes a path that begins with taking experimental measurements, and ends with obtaining insight from results produced by numerical simulation. Two examples illustrate this path: (1) Three-dimensional imaging measurement at micron scale, using X-ray tomography, provides information on the boundaries of irregularly-shaped alumina oxide particles held in an epoxy matrix. A subsequent numerical simulation predicts the electrical field concentrations that would occur in the observed particle configurations. (2) Three-dimensional imaging measurement at meter scale, again using X-ray tomography, provides information on the boundaries fossilized bone fragments in a Parasaurolophus crest recently discovered in New Mexico. A subsequent numerical simulation predicts acoustic response of the elaborate internal structure of nasal passageways defined by the fossil record. The author must both add value, and must change the format of the three-dimensional imaging measurements before the define the geometric boundary initial conditions for the automatic mesh generation, and subsequent numerical simulation. The author applies a variety of filters and statistical classification algorithms to estimate the extents of the structures relevant to the subsequent numerical simulation, and capture these extents as faceted geometries. The author will describe the particular combination of manual and automatic methods used in the above two examples.

  4. Acoustic Transmitters for Underwater Neutrino Telescopes

    Carlos D. Llorens

    2012-03-01

    Full Text Available In this paper acoustic transmitters that were developed for use in underwater neutrino telescopes are presented. Firstly, an acoustic transceiver has been developed as part of the acoustic positioning system of neutrino telescopes. These infrastructures are not completely rigid and require a positioning system in order to monitor the position of the optical sensors which move due to sea currents. To guarantee a reliable and versatile system, the transceiver has the requirements of reduced cost, low power consumption, high pressure withstanding (up to 500 bars, high intensity for emission, low intrinsic noise, arbitrary signals for emission and the capacity of acquiring and processing received signals. Secondly, a compact acoustic transmitter array has been developed for the calibration of acoustic neutrino detection systems. The array is able to mimic the signature of ultra-high-energy neutrino interaction in emission directivity and signal shape. The technique of parametric acoustic sources has been used to achieve the proposed aim. The developed compact array has practical features such as easy manageability and operation. The prototype designs and the results of different tests are described. The techniques applied for these two acoustic systems are so powerful and versatile that may be of interest in other marine applications using acoustic transmitters.

  5. The compact and inexpensive arrowhead setup for holographic interferometry

    Ladera, Celso L; Donoso, Guillermo, E-mail: clladera@usb.v [Departamento de Fisica, Universidad Simon BolIvar, Apdo. 89000, Caracas 1086 (Venezuela, Bolivarian Republic of)

    2011-07-15

    Hologram recording and holographic interferometry are intrinsically sensitive to phase changes, and therefore both are easily perturbed by minuscule optical path perturbations. It is therefore very convenient to bank on holographic setups with a reduced number of optical components. Here we present a compact off-axis holographic setup that requires neither a collimator nor a beam-splitter, and whose layout is reminiscent of an arrowhead. We show that this inexpensive setup is a good alternative for the study and applications of scientific holography by measuring small displacements and deformations of a body. The arrowhead setup will be found particularly useful for holography and holographic interferometry experiments and projects in teaching laboratories.

  6. Evidence of Key Tinnitus-Related Brain Regions Documented by a Unique Combination of Manganese-Enhanced MRI and Acoustic Startle Reflex Testing

    Avril Genene Holt; David Bissig; Najab Mirza; Gary Rajah; Bruce Berkowitz

    2010-01-01

    Animal models continue to improve our understanding of tinnitus pathogenesis and aid in development of new treatments. However, there are no diagnostic biomarkers for tinnitus-related pathophysiology for use in awake, freely moving animals. To address this disparity, two complementary methods were combined to examine reliable tinnitus models (rats repeatedly administered salicylate or exposed to a single noise event): inhibition of acoustic startle and manganese-enhanced MRI. Salicylate-induc...

  7. Investigation of self healing behaviour of asphalt mixes using beam on elastic foundation setup

    Qiu, J.; Molenaar, A.A.A.; Van de Ven, M.F.C.; Wu, S.; Yu, J.

    2012-01-01

    Self healing of asphalt mixes is known for more than four decades. However, it is a complex phenomenon which depends on the duration of the rest period, temperature, crack size, etc. In order to quantify the self healing behaviour of asphalt mixes, a test setup was proposed in this research using an

  8. Integration of micro milling highspeed spindle on a microEDM-milling machine set-up

    De Grave, Arnaud; Hansen, Hans Nørgaard; Andolfatto, Loic

    2009-01-01

    In order to cope with repositioning errors and to combine the fast removal rate of micro milling with the precision and small feature size achievable with micro EDM milling, a hybrid micro-milling and micro-EDM milling centre was built and tested. The aim was to build an affordable set-up, easy t...

  9. Investigation of self healing behaviour of asphalt mixes using beam on elastic foundation setup

    Qiu, J.; Molenaar, A.A.A.; Van de Ven, M.F.C.; Wu, S.; Yu, J.

    2012-01-01

    Self healing of asphalt mixes is known for more than four decades. However, it is a complex phenomenon which depends on the duration of the rest period, temperature, crack size, etc. In order to quantify the self healing behaviour of asphalt mixes, a test setup was proposed in this research using an asphalt beam on an elastic foundation. Within this setup, a notched asphalt beam was glued on a low modulus rubber foundation, and a symmetric monotonic load was applied with loading–unloading–hea...

  10. An experimental set-up to measure Light Yield of Scintillating Fibres

    Alfieri, C; Joram, C; Kenzie, M W

    2015-01-01

    In the context of the LHCb SciFi Tracker project, an experimental set up was designed and built to provide reliable and reproducible measurements of the light yield of scintillating fibres. This document describes the principle and technical realisation of the set-up. A few examples illustrate the operation and data analysis. In the first implementation of the set-up a photomultiplier tube with bialkali photocathode was used for the reading of the light from the fibres under test. In order to measure also green emitting fibres, the photomultiplier was replaced in January 2016 by a SiPM with higher sensitivity and larger spectral coverage1.

  11. Set-up on the basis of multiwire proportional and ionization chambers for radioactive beam experiments

    A large-aperture set-up designed for nuclear physics experiments on beams of radioactive nuclei is described. The set-up includes Multiwire Proportional Chamber (MWPC) for measuring the beam profile, MWPC for measuring reaction product angular distributions, a CsI (Tl)-crystal detector and a longitudinal drift ionization chamber for identifying scattered particles and measuring their energy. The results of tests of coordinate MWPCs, particle identification on photon and ion beams, and preliminary measurements of the elastic scattering and the charge exchange reaction of 170 MeV 6He on a CH2 target are presented

  12. A magnetic resonance-compatible experimental set-up for hyperthermia studies

    This study presents the development and testing of an experimental set-up for simultaneous measurements of pH (intracellular by MR and extracellular by fibre-optic pH meter) tumour bio-energetics (by MR), and core/tumour temperatures (by thermocouples) in tumour-bearing mice. Potential sources of measurement errors when using these techniques concurrently in an MR set-up are discussed. Emphasis is placed on simple practical solutions to these problems. Copyright (1999) Blackwell Science Pty Ltd

  13. Applied acoustics concepts, absorbers, and silencers for acoustical comfort and noise control alternative solutions, innovative tools, practical examples

    Fuchs, Helmut V

    2013-01-01

    The author gives a comprehensive overview of materials and components for noise control and acoustical comfort. Sound absorbers must meet acoustical and architectural requirements, which fibrous or porous material alone can meet. Basics and applications are demonstrated, with representative examples for spatial acoustics, free-field test facilities and canal linings. Acoustic engineers and construction professionals will find some new basic concepts and tools for developments in order to improve acoustical comfort. Interference absorbers, active resonators and micro-perforated absorbers of different materials and designs complete the list of applications.

  14. ACOUSTICAL STANDARDS NEWS.

    Blaeser, Susan B; Struck, Christopher J

    2016-03-01

    American National Standards (ANSI Standards) developed by Accredited Standards Committees S1, S2, S3, S3/SC 1, and S12 in the areas of acoustics, mechanical vibration and shock, bioacoustics, animal bioacoustics, and noise, respectively, are published by the Acoustical Society of America (ASA). In addition to these standards, ASA publishes a catalog of Acoustical American National Standards. To receive a copy of the latest Standards catalog, please contact Susan B. Blaeser.Comments are welcomed on all material in Acoustical Standards News.This Acoustical Standards News section in JASA, as well as the National Catalog of Acoustical Standards and other information on the Standards Program of the Acoustical Society of America, are available via the ASA home page: http://acousticalsociety.org. PMID:27036268

  15. The Acoustical Properties of Indonesian Hardwood Species

    Tarcisius Rio Mardikanto

    2012-08-01

    Full Text Available The acoustical properties of four Indonesian tropical hardwood species were evaluated in this study. The objectives of this study were to determine acoustical parameters e.g. logarithmic decrement, sound absorption, sound velocity as well as density and wood stiffness; and to evaluate the potential of those species for acoustical purposes. Sonokeling (Dalbergia latifolia, Mahoni (Swietenia mahagony, Acacia (Acacia mangium and Manii wood (Maesopsis eminii were selected in this research. Three different cutting plane patterns of sawn timber (quarter-sawn, flat-sawn, and plain-sawn were converted into small specimens. The methods for determining acoustical properties were longitudinal vibration testing and time of flight of ultrasonic wave method. The result showed no significant difference (α=0.05 of acoustical properties in logarithmic decrement, sound absorption, and ultrasonic velocity means on quarter-sawn, flat-sawn, and plain-sawn for all wood species tested. We found that Mahoni and Sonokeling had good acoustical properties of logarithmic decrement, ultrasonic wave velocity, and ratio of wood stiffness to wood density; and is preferred for crafting musical instruments. Acacia and Manii woods are recommended for developing acoustic panels in building construction because those species possess higher sound absorption values.

  16. 1 {\\Omega}-10 k{\\Omega} high precision transportable setup to calibrate multifunction electrical instruments

    Capra, P P

    2015-01-01

    A temperature controlled 1 {\\Omega}-10 k{\\Omega} standard Resistors transportable setup was developed at National Institute of Metrological Research, (INRIM) for the calibration and adjustment of multifunction electrical instruments. The two Standards consist respectively of two 10 {\\Omega} and 100 k{\\Omega} parallel connected resistors nets inserted in a temperature controlled aluminium box. Novelty of the realization is the oil insertion of the 1 {\\Omega} net with its internal connectors lowering the thermo-electromotive forces (emfs) effects. Short and mid-term stabilities of the setup Standards resulted on the order and in some cases better than other top level 1 {\\Omega} and 10 k{\\Omega} commercial Standards. The transport effect turning off the setup temperature control did not cause appreciable measurement deviations on the two Standards. The Standards uncertainties meet those requested by DMMs and MFCs manufacturers to calibrate and adjust these instruments. A test to adjust a multifunction calibrator...

  17. A compact multi-chamber setup for degradation and lifetime studies of organic solar cells

    Gevorgyan, Suren; Jørgensen, Mikkel; Krebs, Frederik C;

    2011-01-01

    chambers with temperature and atmosphere control. The four chambers are situated at close proximity in the setup thereby allowing the solar cells to be subjected to as uniform an illumination distribution as possible for the given solar simulator employed. The cell substrates serve as the front window and...... present a tight seal. Hence no illumination correction needs to be performed due to transmission and reflection losses as otherwise seen with test chambers employing a window as a seal. The solar cells in each chamber are continuously and individually electrically monitored under biased conditions by......A controlled atmosphere setup designed for long-term degradation studies of organic solar cells under illumination is presented. The setup was designed with ease-of-use and compactness in mind and allows for multiple solar cells distributed on four glass substrates to be studied in four different...

  18. Development and design of a multi-column experimental setup for Kr/Xe separation

    Garn, Troy G.; Greenhalgh, Mitchell; Watson, Tony

    2014-12-01

    As a precursor to FY-15 Kr/Xe separation testing, design modifications to an existing experimental setup are warranted. The modifications would allow for multi-column testing to facilitate a Xe separation followed by a Kr separation using engineered form sorbents prepared using an INL patented process. A new cooling apparatus capable of achieving test temperatures to -40° C and able to house a newly designed Xe column was acquired. Modifications to the existing setup are being installed to allow for multi-column testing and gas constituent analyses using evacuated sample bombs. The new modifications will allow for independent temperature control for each column enabling a plethora of test conditions to be implemented. Sample analyses will be used to evaluate the Xe/Kr selectivity of the AgZ-PAN sorbent and determine the Kr purity of the effluent stream following Kr capture using the HZ-PAN sorbent.

  19. Towards field and laboratory experiments with ocean acoustic-gravity waves

    Oliveira, Tiago; Kadri, Usama; Lin, Ying-Tsong; Morozov, Andrey

    2016-04-01

    Acoustic-gravity waves (AGWs) can be generated in the ocean by mechanical energy transfer from the Earth's crust (e.g. earthquakes or volcanoes) and by energy transfer occurring at the water surface (e.g. interaction of opposing gravity waves, ice-quakes or localized pressure changes). Recent theoretical studies shed light on the underlying physics of the generation and propagation of AGWs in the ocean. However, these theories are yet to be verified further with very challenging field experiments due to the associated low frequency signals required, and ambient disturbances involved. Here, we present a unique setup of field experiments and large scale laboratory tests to verify the main physical properties of AGWs in ocean generated by different types of sources. We also present a novel methodology to generate and measure AGWs in the ocean.

  20. Acoustic interaction with vortex structures shed by an obstacle in a closed cavity

    Biron, D.; Hebrard, P.; Pauzin, S.; Garnier, F.; Labegorre, B.; Laverdant, A.

    CERT-DERMES has created an experimental set-up for studying the interaction between acoustics and coherent structures. The set-up comprises a subsonic diffuser, a rectangular wind tunnel with a square prismatic obstacle placed at an incidence to shed vortices, and a converging-diverging nozzle. The sound waves are observed to be amplified when the acoustic triggering and vortex shedding frequencies are close to one another. A numerical simulation using an adapted version of the KIVA code developed at Los Alamos replicated experimental vortex shedding with particle dyes. The experimental and numerical Strouhal numbers for the vortex shedding behind the obstacle are in good agreement with previously published results.

  1. Insertion Loss Analysis of the Acoustic Panels with Composite Construction

    Vasile Ovidiu

    2013-09-01

    Full Text Available In order to reduce noise pollution, under European legislation in our country need to align, a special attention has the tests carried out on acoustic panels. The most eloquent attempts, defining traffic noise attenuation are tests that can determine the insertion loss of an acoustic screen. In this paper, it briefly shows the method of determining the insertion loss in octave bands and some real results in the case of acoustic panel in a composite construction.

  2. Scaling and dimensional analysis of acoustic streaming jets

    This paper focuses on acoustic streaming free jets. This is to say that progressive acoustic waves are used to generate a steady flow far from any wall. The derivation of the governing equations under the form of a nonlinear hydrodynamics problem coupled with an acoustic propagation problem is made on the basis of a time scale discrimination approach. This approach is preferred to the usually invoked amplitude perturbations expansion since it is consistent with experimental observations of acoustic streaming flows featuring hydrodynamic nonlinearities and turbulence. Experimental results obtained with a plane transducer in water are also presented together with a review of the former experimental investigations using similar configurations. A comparison of the shape of the acoustic field with the shape of the velocity field shows that diffraction is a key ingredient in the problem though it is rarely accounted for in the literature. A scaling analysis is made and leads to two scaling laws for the typical velocity level in acoustic streaming free jets; these are both observed in our setup and in former studies by other teams. We also perform a dimensional analysis of this problem: a set of seven dimensionless groups is required to describe a typical acoustic experiment. We find that a full similarity is usually not possible between two acoustic streaming experiments featuring different fluids. We then choose to relax the similarity with respect to sound attenuation and to focus on the case of a scaled water experiment representing an acoustic streaming application in liquid metals, in particular, in liquid silicon and in liquid sodium. We show that small acoustic powers can yield relatively high Reynolds numbers and velocity levels; this could be a virtue for heat and mass transfer applications, but a drawback for ultrasonic velocimetry

  3. The Setup Programmable Logical Controller (PLC) and an asynchronous engine

    Černý, David

    2013-01-01

    The aim of this Bachelor Thesis is to design a Setup using the Programmable Logic Controller (PLC). The five essential assignments were prepared using both digital and analog PLC?s inputs and outputs. The purpose of the assignments is to teach and demonstrate the functionality of the PLC Setup.

  4. The Compact and Inexpensive "Arrowhead" Setup for Holographic Interferometry

    Ladera, Celso L.; Donoso, Guillermo

    2011-01-01

    Hologram recording and holographic interferometry are intrinsically sensitive to phase changes, and therefore both are easily perturbed by minuscule optical path perturbations. It is therefore very convenient to bank on holographic setups with a reduced number of optical components. Here we present a compact off-axis holographic setup that…

  5. Modeling and simulation of LHC beam-based collimator setup

    Valentino, G; Assmann, R W; Burkart, F; Redaelli, S; Rossi, A; Lari, L

    2012-01-01

    In the 2011 Large Hadron Collider run, collimators were aligned for proton and heavy ion beams using a semiautomatic setup algorithm. The algorithm provided a reduction in the beam time required for setup, an elimination of beam dumps during setup and better reproducibility with respect to manual alignment. A collimator setup simulator was developed based on a Gaussian model of the beam distribution as well as a parametric model of the beam losses. A time-varying beam loss signal can be simulated for a given collimator movement into the beam. The simulation results and comparison to measurement data obtained during collimator setups and dedicated fills for beam halo scraping are presented. The simulator will then be used to develop a fully automatic collimator alignment algorithm.

  6. Characterizing Acoustic Sources in Pressure Vessels

    李路明; 郑鹏; 刘时风; 施克仁

    2002-01-01

    The "dream" of acoustic emission (AE) testing is to get the acoustic source characteristics from AE signals, especially when evaluating aging pressure vessels. In this paper, the wavelet transform was used to analyze different AE signals from cracks (surface and inner), pencil-lead-breakage and leakage. These acoustic sources were applied on an actual pressure vessel. While the vessel experienced hydraulic pressure, their AE signals were acquired by a digital AE testing system with a wide frequency band transducer and a high speed A/D converter. Then, the digital signals were analyzed using the wavelet transform method. Correlation coefficients of the transformed data show that the different acoustic sources can be easily identified.

  7. 声波透射法在基桩检测中影响因素的深入分析%Analysis and Discussion About the Influencing Factors in the Pile Foundation Test by Acoustic Wave Transmission Method

    赵守全; 赵常要; 朱兆荣

    2016-01-01

    This article is based on sound wave transmission method,analyzes the influence factors of pile foundation testing and points out the factors of the testing instrument,acoustic detecting tube material,temperature of testing environment, blocking pipe and tubes which are not parallel will affect the test results.Therefore,the influence degree of the influence factors on the test results and its mechanism are carried on analysis thoroughly,such as sound velocity anomaly problems caused by the acoustic detection tube is not parallel,although correction method is more,there are some limitations and shortcomings.The paper,adopts the correction method based on acoustic detecting tube space position relations,has achieved good correction effect,and consequently presents the corresponding processing methods or measures to reduce the influence degree of these factors on the test results,and finally the reliability of the testing results of sound wave transmis-sion method is improved.%本文就声波透射法在基桩检测中的影响因素这一问题进行了深入分析,指出了检测仪器、声测管材质、检测环境的温度、堵管、声测管不平行等因素都会对结果分析产生影响,并针对这些因素对检测结果的影响程度及机理进行了深入分析,如声测管不平行引起的声速异常问题,虽然修正方法较多,但都有一定的局限性和弊端,本文采用了基于声测管空间位置关系的修正方法取得了良好的修正效果,进一步给出了相应的处理方法或措施,使这些因素对检测结果的影响程度有效降低,提高了声波透射法检测结果的可信度。

  8. Fast neutrons transmission measurement setup at KFUPM

    Naqvi, A.A. [King Fahd University of Petroleum and Minerals, Center for Applied Physical Sciences, Dhahran (Saudi Arabia); Rehman Khateeb-ur; Nagadi, M.M.; Kidwai, S. [Kind Fahd University of Petroleum and Minerals, Department of Physics, Dhahran (Saudi Arabia)

    2002-08-01

    A fast neutron transmission based experimental set up has been developed to determine concentration of hydrogen in the bulk sample. The facility has been tested with transmission of 2.8 MeV neutrons through cylindrical samples. NE213 scintillation detector was used to detect transmitted fast neutrons. In preliminary tests of the facility wood and soil samples containing known amount of water were analyzed. Intensity of fast neutrons transmitted through the samples shows linear correlation with water contents of the soil sample. The facility and results of the preliminary tests will be presented. (author)

  9. First images of thunder: Acoustic imaging of triggered lightning

    Dayeh, M. A.; Evans, N. D.; Fuselier, S. A.; Trevino, J.; Ramaekers, J.; Dwyer, J. R.; Lucia, R.; Rassoul, H. K.; Kotovsky, D. A.; Jordan, D. M.; Uman, M. A.

    2015-07-01

    An acoustic camera comprising a linear microphone array is used to image the thunder signature of triggered lightning. Measurements were taken at the International Center for Lightning Research and Testing in Camp Blanding, FL, during the summer of 2014. The array was positioned in an end-fire orientation thus enabling the peak acoustic reception pattern to be steered vertically with a frequency-dependent spatial resolution. On 14 July 2014, a lightning event with nine return strokes was successfully triggered. We present the first acoustic images of individual return strokes at high frequencies (>1 kHz) and compare the acoustically inferred profile with optical images. We find (i) a strong correlation between the return stroke peak current and the radiated acoustic pressure and (ii) an acoustic signature from an M component current pulse with an unusual fast rise time. These results show that acoustic imaging enables clear identification and quantification of thunder sources as a function of lightning channel altitude.

  10. Acoustic detection of air shower cores

    Gao, X.; Liu, Y.; Du, S.

    1985-01-01

    At an altitude of 1890m, a pre-test with an Air shower (AS) core selector and a small acoustic array set up in an anechoic pool with a volume of 20x7x7 cu m was performed, beginning in Aug. 1984. In analyzing the waveforms recorded during the effective working time of 186 hrs, three acoustic signals which cannot be explained as from any source other than AS cores were obtained, and an estimation of related parameters was made.

  11. World Conference on Acoustic Emission 2013

    Wu, Zhanwen; Zhang, Junjiao

    2015-01-01

    This volume collects the papers from the 2013 World Conference on Acoustic Emission in Shanghai. The latest research and applications of Acoustic Emission (AE) are explored, with particular emphasis on detecting and processing of AE signals, development of AE instrument and testing standards, AE of materials, engineering structures and systems, including the processing of collected data and analytical techniques as well as experimental case studies.

  12. Performance comparison of an 241Am-Be neutron source-based PGNAA setup with the KFUPM PGNAA setup

    Monte Carlo calculations have been carried out to compare the performance of an 241Am-Be neutron source-based prompt gamma neutron activation analysis (PGNAA) setup with that of the 2.8 MeV neutron-based PGNAA setup at King Fahd University of Petroleum and Minerals (KFUPM) to analyze Portland cement samples. This work is a part of a wide Monte Carlo studies being conducted at KFUPM in search of a more efficient neutron source for its 2.8 MeV neutrons, from the D(d,n) reaction, based PGNAA facility. In this study an 241Am-Be neutron source-based PGNAA setup was simulated. For comparison, the diameter of a cylindrical external moderator of the 241Am-Be neutron source, based PGNAA setup, was assumed to be similar to that used in the KFUPM PGNAA setup. It was revealed that although the optimum geometry of the 241Am-Be neutron source-based setup is similar to that of the KFUPM PGNAA facility, the performance of the 241Am-Be neutron source-based setup is slightly poorer than that of the 2.8 MeV neutron-based setup. (author)

  13. Indirect calibration of a large microphone array for in-duct acoustic measurements

    Leclère, Q.; Pereira, A.; Finez, A.; Souchotte, P.

    2016-08-01

    This paper addresses the problem of in situ calibration of a pin hole-mounted microphone array for in-duct acoustic measurements. One approach is to individually measure the frequency response of each microphone, by submitting the probe to be calibrated and a reference microphone to the same pressure field. Although simple, this task may be very time consuming for large microphone arrays and eventually suffer from lack of access to microphones once they are installed on the test bench. An alternative global calibration procedure is thus proposed in this paper. The approach is based on the fact that the acoustic pressure can be expanded onto an analytically known spatial basis. A projection operator is defined allowing the projection of measurements onto the duct modal basis. The main assumption of the method is that the residual resulting from the difference between actual and projected measurements is mainly dominated by calibration errors. An iterative procedure to estimate the calibration factors of each microphone is proposed and validated through an experimental set-up. In addition, it is shown that the proposed scheme allows an optimization of physical parameters such as the sound speed and parameters associated to the test bench itself, such as the duct radius or the termination reflection coefficient.

  14. D2声学测量系统的测试功能%Testing Function of The D2 Acoustic Measurement System

    王延君

    2010-01-01

    @@ D2声学测量系统,是美国AcoustX公司专为影院的综合测试和测量而设计的一套声学测量工具,已经通过了卢卡斯的认证.其中包括如图1所示的4支话筒及支架、D2调制器、D2控制器、USBPre 数字音频接口及Win|RTA测试软件(在所附光盘上).

  15. Valveless micropump driven by acoustic streaming

    This paper describes two valveless micropumps built on a 260 µm thick PZT with 20 µm thick parylene acoustic Fresnel lenses with air cavities. The micropumps produce in-plane body force through acoustic streaming effect of high-intensity acoustic beam that is generated by acoustic wave interference. The fabricated micropumps were shown to move microspheres, which have a diameter of 70–90 µm and a density of 0.99 g cm−3, on the water surface to form U-shape streams of microspheres with a drift velocity of 7.3 cm s−1 when the micropumps were located 4 mm below the water surface and driven by 160 Vpeak-to-peak pulsed sinusoidal waves. The driven microspheres formed U-shape streaming even without any fluidic channel according to the serial connection of the pie-shaped lenses and top electrodes. A micropump with a straight-lined fluidic channel was also fabricated and tested to show a 9.2 cm s−1 microspheres' drift velocity and a 9.5 mL min−1 volume pumping rate when combined with the acrylic acoustic wave reflector. Both the Fresnel lens and top electrode were patterned in a pie-shape with its apex angle of 90° to form asymmetric acoustic pressure distribution at the focal plane of the acoustic Fresnel lenses in order to push water in one direction. (paper)

  16. Acoustic streaming in microchannels

    Tribler, Peter Muller

    , and experimental results for the streaming-induced drag force dominated motion of particles suspended in a water-filled microchannel supporting a transverse half-wavelength resonance. The experimental and theoretical results agree within a mean relative dierence of approximately 20%, a low deviation given state......This thesis presents studies of boundary-driven acoustic streaming in microfluidic channels, which is a steady flow of the fluid initiated by the interactions of an oscillating acoustic standing wave and the rigid walls of the microchannel. The studies present analysis of the acoustic resonance......, the acoustic streaming flow, and the forces on suspended microparticles. The work is motivated by the application of particle focusing by acoustic radiation forces in medical, environmental and food sciences. Here acoustic streaming is most often unwanted, because it limits the focusability of particles...

  17. Vibro-acoustics

    Nilsson, Anders

    2015-01-01

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

  18. Springer handbook of acoustics

    2014-01-01

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

  19. High-resolution continuous flow analysis setup for water isotopic measurement from ice cores using laser spectroscopy

    Emanuelsson, B. D.; Baisden, W. T.; Bertler, N. A. N.; Keller, E. D.; Gkinis, V.

    2014-12-01

    Here we present an experimental setup for water stable isotopes (δ18O and δD) continuous flow measurements. It is the first continuous flow laser spectroscopy system that is using Off-Axis Integrated Cavity Output Spectroscopy (OA-ICOS; analyzer manufactured by Los Gatos Research - LGR) in combination with an evaporation unit to continuously analyze sample from an ice core. A Water Vapor Isotopic Standard Source (WVISS) calibration unit, manufactured by LGR, was modified to: (1) increase the temporal resolution by reducing the response time (2) enable measurements on several water standards, and (3) to reduce the influence from memory effects. While this setup was designed for the Continuous Flow Analysis (CFA) of ice cores, it can also continuously analyze other liquid or vapor sources. The modified setup provides a shorter response time (~54 and 18 s for 2013 and 2014 setup, respectively) compared to the original WVISS unit (~62 s), which is an improvement in measurement resolution. Another improvement compared to the original WVISS is that the modified setup has a reduced memory effect. Stability tests comparing the modified WVISS and WVISS setups were performed and Allan deviations (σAllan) were calculated to determine precision at different averaging times. For the 2013 modified setup the precision after integration times of 103 s are 0.060 and 0.070‰ for δ18O and δD, respectively. For the WVISS setup the corresponding σAllan values are 0.030, 0.060 and 0.043‰ for δ18O, δD and δ17O, respectively. For the WVISS setup the precision is 0.035, 0.070 and 0.042‰ after 103 s for δ18O, δD and δ17O, respectively. Both the modified setups and WVISS setup are influenced by instrumental drift with δ18O being more drift sensitive than δD. The σAllan values for δ18O of 0.30 and 0.18‰ for the modified (2013) and WVISS setup, respectively after averaging times of 104 s (2.78 h). The Isotopic Water Analyzer (IWA)-modified WVISS setup used during the

  20. The dose distribution and DVH change analysis wing to effect of the patient setup error

    The setup error due to the patient and the staff from radiation treatment as the reason which is important the treatment record could be decided is a possibility of effect. The SET-UP ERROR of the patient analyzes the effect of dose distribution and DVH from radiation treatment of the patient. This test uses human phantom and when C-T scan doing, It rotated the Left direction of the human phantom and it made SET-UP ERROR, Standard plan and 3 mm, 5 mm, 7 mm, 10 mm, 15 mm, 20 mm with to distinguish, it made the C-T scan error. With the result, The SET-UP ERROR got each C-T image Using RTP equipment It used the plan which is used generally from clinical - Box plan, 3 Dimension plan( identical angle 5beam plan) Also, ( CTV+1cm margin, CTV+0.5cm margin, CTV+0.3,cm margin = PTV) it distinguished the standard plan and each set-up error plan and the plan used a dose distribution and the DVH and it analyzed. The Box 4 the plan and 3 Dimension plan which it bites it got similar an dose distribution and DVH in 3 mm, 5 mm From rotation error and Rectilinear movement (0%-2%). Rotation error and rectilinear error 7 mm, 10 mm, 15 mm, 20 mm appeared effect it will go mad to a enough change in treatment (2%-11%) The diminishes the effect of the SET-UP ERROR must reduce move with tension of the patient Also, we are important accessory development and the supply that it reducing of reproducibility and the move.

  1. Collider shot setup for Run 2 observations and suggestions

    This note is intended to provoke discussion on Collider Run II shot setup. We hope this is a start of activities that will converge on a functional description of what is needed for shot setups in Collider Run II. We will draw on observations of the present shot setup to raise questions and make suggestions for the next Collider run. It is assumed that the reader has some familiarity with the Collider operational issues. Shot setup is defined to be the time between the end of a store and the time the Main Control Room declares colliding beams. This is the time between Tevatron clock events SCE and SCB. This definition does not consider the time experiments use to turn on their detectors. This analysis was suggested by David Finley. The operational scenarios for Run II will require higher levels of reliability and speed for shot setup. See Appendix I and II. For example, we estimate that a loss of 3 pb-1/week (with 8 hour stores) will occur if shot setups take 90 minutes instead of 30 minutes. In other words: If you do 12 shots for one week and accept an added delay of one minute in each shot, you will loose more than 60 nb-1 for that week alone (based on a normal shot setup of 30 minutes). These demands should lead us to be much more pedantic about all the factors that affect shot setups. Shot setup will be viewed as a distinct process that is composed of several inter- dependent 'components': procedures, hardware, controls, and sociology. These components don't directly align with the different Accelerator Division departments, but are topical groupings of the needed accelerator functions. Defining these components, and categorizing our suggestions within them, are part of the goal of this document. Of course, some suggestions span several of these components

  2. Analysis of patient setup accuracy using electronic portal imaging device

    Radiation therapy is performed in many fractions, and accurate patient setup is very important. This is more significant nowadays because treatment planning and radiation therapy are more precisely performed. Electronic portal imaging devices and automatic image comparison algorithms let us analyze setup deviations quantitatively. With such in mind we developed a simple image comparison algorithm. Using 2459 electronic verification images (335 ports, 123 treatment sites) generated during the past three years at our institute, we evaluated the results of the algorithm, and analyzed setup deviations according to the area irradiated, use of a fixing device (shell), and arm position. Calculated setup deviation was verified visually and their fitness was classified into good, fair, bad, and incomplete. The result was 40%, 14%, 22%, 24% respectively. Using calculated deviations classified as good (994 images), we analyzed setup deviations. Overall setup deviations described in 1 SD along axes x, y, z, was 1.9 mm, 2.5 mm, 1.7 mm respectively. We classified these deviations into systematic and random components, and found that random error was predominant in our institute. The setup deviations along axis y (cranio-caudal direction) showed larger distribution when treatment was performed with the shell. Deviations along y (cranio-caudal) and z (anterior-posterior) had larger distribution when treatment occurred with the patient's arm elevated. There was a significant time-trend error, whose deviations become greater with time. Within all evaluated ports, 30% showed a time-trend error. Using an electronic portal imaging device and automatic image comparison algorithm, we are able to analyze setup deviations more precisely and improve setup method based on objective criteria. (author)

  3. Localized Acoustic Surface Modes

    Farhat, Mohamed

    2015-08-04

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

  4. Shallow Water Acoustic Laboratory

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

  5. Handbook of Engineering Acoustics

    Möser, Michael

    2013-01-01

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

  6. Acoustic dispersive prism

    Esfahlani, Hussein; Karkar, Sami; Lissek, Herve; Mosig, Juan R.

    2016-01-01

    The optical dispersive prism is a well-studied element, which allows separating white light into its constituent spectral colors, and stands in nature as water droplets. In analogy to this definition, the acoustic dispersive prism should be an acoustic device with capability of splitting a broadband acoustic wave into its constituent Fourier components. However, due to the acoustical nature of materials as well as the design and fabrication difficulties, there is neither any natural acoustic counterpart of the optical prism, nor any artificial design reported so far exhibiting an equivalent acoustic behaviour. Here, based on exotic properties of the acoustic transmission-line metamaterials and exploiting unique physical behaviour of acoustic leaky-wave radiation, we report the first acoustic dispersive prism, effective within the audible frequency range 800 Hz-1300 Hz. The dispersive nature, and consequently the frequency-dependent refractive index of the metamaterial are exploited to split the sound waves towards different and frequency-dependent directions. Meanwhile, the leaky-wave nature of the structure facilitates the sound wave radiation into the ambient medium.

  7. A simplified nitrogen laser setup operated at atmospheric pressure

    Ruangsri, Artit; Wungmool, Piyachat; Tesana, Siripong; Suwanatus, Suchat; Hormwantha, Tongchai; Chiangga, Surasak; Luengviriya, Chaiya

    2015-07-01

    A transversely excited atmospheric pressure nitrogen laser (TEA N2 Laser) is a molecular pulse gas laser, operated at atmospheric pressure, which generates an electromagnetic wave in ultraviolet wavelength of 337.1 nm. It can operate without an optical resonator. We present a TEA N2 laser setup excited by an electronic discharge circuit known as the Blumlein circuit. Our setup is composed of simple components commonly found in everyday life. The setup can be utilized in classroom to demonstrate the dependence of the laser intensity on the flow rate of nitrogen gas.

  8. Six-dimensional fixed points from Hanany-Witten setups

    We present how to construct 6d fixed point theories via Hanany-Witten setups. It is shown that consistency of the brane setup is equivalent to anomaly freedom of the gauge theory. The brane realization of the fixed point theory allows us to study deformations and phase transitions. Coupling the 6d theory as a flavor system to a 4d Hanany-Witten setup these 6d transitions lead to a chirality changing phase transition in the resulting N = 1 supersymmetric 4d theory. (author)

  9. What Is an Acoustic Neuroma

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

  10. Influence of surface acoustic waves induced acoustic streaming on the kinetics of electrochemical reactions

    Tietze, Sabrina; Schlemmer, Josefine; Lindner, Gerhard

    2013-12-01

    The kinetics of electrochemical reactions is controlled by diffusion processes of charge carriers across a boundary layer between the electrode and the electrolyte, which result in a shielding of the electric field inside the electrolyte and a concentration gradient across this boundary layer. In accumulators the diffusion rate determines the rather long time needed for charging, which is a major drawback for electric mobility. This diffusion boundary can be removed by acoustic streaming in the electrolyte induced by surface acoustic waves propagating of the electrode, which results in an increase of the charging current and thus in a reduction of the time needed for charging. For a quantitative study of the influence of acoustic streaming on the charge transport an electropolishing cell with vertically oriented copper electrodes and diluted H3PO4-Propanol electrolytes were used. Lamb waves with various excitation frequencies were exited on the anode with different piezoelectric transducers, which induced acoustic streaming in the overlaying electrolytic liquid. An increase of the polishing current of up to approximately 100 % has been obtained with such a set-up.

  11. Impact of the frequency of online verifications on the patient set-up accuracy and set-up margins

    Mohamed Adel

    2011-08-01

    Full Text Available Abstract Purpose The purpose of the study was to evaluate the patient set-up error of different anatomical sites, to estimate the effect of different frequencies of online verifications on the patient set-up accuracy, and to calculate margins to accommodate for the patient set-up error (ICRU set-up margin, SM. Methods and materials Alignment data of 148 patients treated with inversed planned intensity modulated radiotherapy (IMRT or three-dimensional conformal radiotherapy (3D-CRT of the head and neck (n = 31, chest (n = 72, abdomen (n = 15, and pelvis (n = 30 were evaluated. The patient set-up accuracy was assessed using orthogonal megavoltage electronic portal images of 2328 fractions of 173 planning target volumes (PTV. In 25 patients, two PTVs were analyzed where the PTVs were located in different anatomical sites and treated in two different radiotherapy courses. The patient set-up error and the corresponding SM were retrospectively determined assuming no online verification, online verification once a week and online verification every other day. Results The SM could be effectively reduced with increasing frequency of online verifications. However, a significant frequency of relevant set-up errors remained even after online verification every other day. For example, residual set-up errors larger than 5 mm were observed on average in 18% to 27% of all fractions of patients treated in the chest, abdomen and pelvis, and in 10% of fractions of patients treated in the head and neck after online verification every other day. Conclusion In patients where high set-up accuracy is desired, daily online verification is highly recommended.

  12. Modified matrix volatilization setup for characterization of high purity germanium.

    Meruva, Adisesha Reddy; Raparthi, Shekhar; Kumar, Sunil Jai

    2016-01-01

    Modified matrix volatilization (MV) method has been described to characterize high purity germanium material of 7 N (99.99999%) purity. Transport of both, the chlorine gas generated in-situ in this method and the argon gas (carrier) is fine controlled by means of a mass flow controller. This enabled both uniform reaction of chlorine gas with the germanium matrix and smooth removal of germanium matrix as its chloride. This resulted in improvement in the reproducibility of the analytical results. The use of quartz reaction vessel has lead to the reduction in the process blank levels. The combined effect of these modifications in the MV setup has resulted in very consistent and low process blanks and hence improved detection limits of this method. Applicability of the method has been expanded to rare earth elements and other elements after examining their recoveries. The quantification is done by using inductively coupled plasma quadrupole mass spectrometer (ICP-QMS) and continuum source graphite furnace atomic absorption spectrometry (CS-GFAAS). In the absence of certified reference materials for high pure germanium, the accuracy of the method is established by spike recovery tests. The precision of the method has been found to vary from 1 to 30% for concentrations between 1 and 30 ng g(-1). The limits of detection (LOD) for the target analytes are found to be between 18 and 0.033 ng g(-1). PMID:26695261

  13. The research of knitting needle status monitoring setup

    Liu, Lu; Liao, Xiao-qing; Zhu, Yong-kang; Yang, Wei; Zhang, Pei; Zhao, Yong-kai; Huang, Hui-jie

    2013-09-01

    In textile production, quality control and testing is the key to ensure the process and improve the efficiency. Defect of the knitting needles is the main factor affecting the quality of the appearance of textiles. Defect detection method based on machine vision and image processing technology is universal. This approach does not effectively identify the defect generated by damaged knitting needles and raise the alarm. We developed a knitting needle status monitoring setup using optical imaging, photoelectric detection and weak signal processing technology to achieve real-time monitoring of weaving needles' position. Depending on the shape of the knitting needle, we designed a kind of Glass Optical Fiber (GOF) light guides with a rectangular port used for transmission of the signal light. To be able to capture the signal of knitting needles accurately, we adopt a optical 4F system which has better imaging quality and simple structure and there is a rectangle image on the focal plane after the system. When a knitting needle passes through position of the rectangle image, the reflected light from needle surface will back to the GOF light guides along the same optical system. According to the intensity of signals, the computer control unit distinguish that the knitting needle is broken or curving. The experimental results show that this system can accurately detect the broken needles and the curving needles on the knitting machine in operating condition.

  14. Two color probing of the ultrafast photo-acoustic response in a single biological cell

    The measurement of the mechanical properties of single biological cells with a nanometer depth resolution using only coherent light is proposed. A pump-probe set-up based on an ultrafast laser (100 fs pulses) is used to excite and detect acoustic frequencies in the GHz range. Experiments are performed on single fixed mouse MC3T3 cells adhering on titanium alloy substrate. Using two different probe wavelengths, the contributions to the optical detection resulting from the cell interface displacements and from interactions between acoustic waves and the laser light are identified. Semi-analytical calculations allow the determination of acoustic celerities and thicknesses in cells thinner than 150 nm.

  15. The COMPASS Setup for Physics with Hadron Beams

    Abbon, Ph.; Akhunzyanov, R.; Alexandrov, Yu.; Alexeev, M.G.; Alexeev, G.D.; Amoroso, A.; Andrieux, V.; Anosov, V.; Austregesilo, A.; Badelek, B.; Balestra, F.; Barth, J.; Baum, G.; Beck, R.; Bedfer, Y.; Berlin, A.; Bernhard, J.; Bicker, K.; Bielert, E.R.; Bieling, J.; Birsa, R.; Bisplinghoff, J.; Bodlak, M.; Boer, M.; Bordalo, P.; Bradamante, F.; Braun, C.; Bressan, A.; Buchele, M.; Burtin, E.; Capozza, L.; Ciliberti, P.; Chiosso, M.; Chung, S.U.; Cicuttin, A.; Colantoni, M.; Cotte, D.; Crespo, M.L.; Curiel, Q.; Dafni, T.; Dalla Torre, S.; Dasgupta, S.S.; Dasgupta, S.; Denisov, O.Yu.; Desforge, D.; Dinkelbach, A.M.; Donskov, S.V.; Doshita, N.; Duic, V.; Dunnweber, W.; Durand, D.; Dziewiecki, M.; Efremov, A.; Elia, C.; Eversheim, P.D.; Eyrich, W.; Faessler, M.; Ferrero, A.; Finger, M.; M. Finger jr; Fischer, H.; Franco, C.; von Hohenesche, N. du Fresne; Friedrich, J.M.; Frolov, V.; Gatignon, L.; Gautheron, F.; Gavrichtchouk, O.P.; Gerassimov, S.; Geyer, R.; Giganon, A.; Gnesi, I.; Gobbo, B.; Goertz, S.; Gorzellik, M.; Grabmuller, S.; Grasso, A.; Gregori, M.; Grube, B.; Grussenmeyer, T.; Guskov, A.; Haas, F.; von Harrach, D.; Hahne, D.; Hashimoto, R.; Heinsius, F.H.; Herrmann, F.; Hinterberger, F.; Hoppner, Ch.; Horikawa, N.; d'Hose, N.; Huber, S.; Ishimoto, S.; Ivanov, A.; Ivanshin, Yu.; Iwata, T.; Jahn, R.; Jary, V.; Jasinski, P.; Jorg, P.; Joosten, R.; Kabuss, E.; Ketzer, B.; Khaustov, G.V.; Khokhlov, Yu. A.; Kisselev, Yu.; Klein, F.; Klimaszewski, K.; Koivuniemi, J.H.; Kolosov, V.N.; Kondo, K.; Konigsmann, K.; Konorov, I.; Konstantinov, V.F.; Kotzinian, A.M.; Kouznetsov, O.; Kramer, M.; Kroumchtein, Z.V.; Kuchinski, N.; Kuhn, R.; Kunne, F.; Kurek, K.; Kurjata, R.P.; Lednev, A.A.; Lehmann, A.; Levillain, M.; Levorato, S.; Lichtenstadt, J.; Maggiora, A.; Magnon, A.; Makke, N.; Mallot, G.K.; Marchand, C.; Marroncle, J.; Martin, A.; Marzec, J.; Matousek, J.; Matsuda, H.; Matsuda, T.; Menon, G.; Meshcheryakov, G.; Meyer, W.; Michigami, T.; Mikhailov, Yu. V.; Miyachi, Y.; Moinester, M.A.; Nagaytsev, A.; Nagel, T.; Nerling, F.; Neubert, S.; Neyret, D.; Nikolaenko, V.I.; Novy, J.; Nowak, W.D.; Nunes, Ana Sofia; Olshevsky, A.G.; Orlov, I.; Ostrick, M.; Panknin, R.; Panzieri, D.; Parsamyan, B.; Paul, S.; Pesaro, G.; Pesaro, V.; Peshekhonov, D.V.; Pires, C.; Platchkov, S.; Pochodzalla, J.; Polyakov, V.A.; Pretz, J.; Quaresma, M.; Quintans, C.; Ramos, S.; Regali, C.; Reicherz, G.; Reymond, J-M.; Rocco, E.; Rossiyskaya, N.S.; Rousse, J.Y.; Ryabchikov, D.I.; Rychter, A.; Samartsev, A.; Samoylenko, V.D.; Sandacz, A.; Sarkar, S.; Savin, I.A.; Sbrizzai, G.; Schiavon, P.; Schill, C.; Schluter, T.; Schmidt, K.; Schmieden, H.; Schonning, K.; Schopferer, S.; Schott, M.; Shevchenko, O.Yu.; Silva, L.; Sinha, L.; Sirtl, S.; Slunecka, M.; Sosio, S.; Sozzi, F.; Srnka, A.; Steiger, L.; Stolarski, M.; Sulc, M.; Sulej, R.; Suzuki, H.; Szabelski, A.; Szameitat, T.; Sznajder, P.; Takekawa, S.; Wolbeek, J. ter; Tessaro, S.; Tessarotto, F.; Thibaud, F.; Tskhay, V.; Uhl, S.; Uman, I.; Virius, M.; Wang, L.; Weisrock, T.; Weitzel, Q.; Wilfert, M.; Windmolders, R.; Wollny, H.; Zaremba, K.; Zavertyaev, M.; Zemlyanichkina, E.; Ziembicki, M.; Zink, A.

    2015-01-01

    The main characteristics of the COMPASS experimental setup for physics with hadron beams are described. This setup was designed to perform exclusive measurements of processes with several charged and/or neutral particles in the final state. Making use of a large part of the apparatus that was previously built for spin structure studies with a muon beam, it also features a new target system as well as new or upgraded detectors. The hadron setup is able to operate at the high incident hadron flux available at CERN. It is characterised by large angular and momentum coverages, large and nearly flat acceptances, and good two and three-particle mass resolutions. In 2008 and 2009 it was successfully used with positive and negative hadron beams and with liquid hydrogen and solid nuclear targets. This article describes the new and upgraded detectors and auxiliary equipment, outlines the reconstruction procedures used, and summarises the general performance of the setup.

  16. The COMPASS setup for physics with hadron beams

    Abbon, P.; Adolph, C.; Akhunzyanov, R.; Alexandrov, Yu.; Alexeev, M. G.; Alexeev, G. D.; Amoroso, A.; Andrieux, V.; Anosov, V.; Austregesilo, A.; Badełek, B.; Balestra, F.; Barth, J.; Baum, G.; Beck, R.; Bedfer, Y.; Berlin, A.; Bernhard, J.; Bicker, K.; Bielert, E. R.; Bieling, J.; Birsa, R.; Bisplinghoff, J.; Bodlak, M.; Boer, M.; Bordalo, P.; Bradamante, F.; Braun, C.; Bressan, A.; Büchele, M.; Burtin, E.; Capozza, L.; Ciliberti, P.; Chiosso, M.; Chung, S. U.; Cicuttin, A.; Colantoni, M.; Cotte, D.; Crespo, M. L.; Curiel, Q.; Dafni, T.; Dalla Torre, S.; Dasgupta, S. S.; Dasgupta, S.; Denisov, O. Yu.; Desforge, D.; Dinkelbach, A. M.; Donskov, S. V.; Doshita, N.; Duic, V.; Dünnweber, W.; Durand, D.; Dziewiecki, M.; Efremov, A.; Elia, C.; Eversheim, P. D.; Eyrich, W.; Faessler, M.; Ferrero, A.; Finger, M.; Finger, M.; Fischer, H.; Franco, C.; du Fresne von Hohenesche, N.; Friedrich, J. M.; Frolov, V.; Gatignon, L.; Gautheron, F.; Gavrichtchouk, O. P.; Gerassimov, S.; Geyer, R.; Giganon, A.; Gnesi, I.; Gobbo, B.; Goertz, S.; Gorzellik, M.; Grabmüller, S.; Grasso, A.; Gregori, M.; Grube, B.; Grussenmeyer, T.; Guskov, A.; Haas, F.; von Harrach, D.; Hahne, D.; Hashimoto, R.; Heinsius, F. H.; Herrmann, F.; Hinterberger, F.; Höppner, Ch.; Horikawa, N.; d`Hose, N.; Huber, S.; Ishimoto, S.; Ivanov, A.; Ivanshin, Yu.; Iwata, T.; Jahn, R.; Jary, V.; Jasinski, P.; Jörg, P.; Joosten, R.; Kabuß, E.; Ketzer, B.; Khaustov, G. V.; Khokhlov, Yu. A.; Kisselev, Yu.; Klein, F.; Klimaszewski, K.; Koivuniemi, J. H.; Kolosov, V. N.; Kondo, K.; Königsmann, K.; Konorov, I.; Konstantinov, V. F.; Kotzinian, A. M.; Kouznetsov, O.; Krämer, M.; Kroumchtein, Z. V.; Kuchinski, N.; Kuhn, R.; Kunne, F.; Kurek, K.; Kurjata, R. P.; Lednev, A. A.; Lehmann, A.; Levillain, M.; Levorato, S.; Lichtenstadt, J.; Maggiora, A.; Magnon, A.; Makke, N.; Mallot, G. K.; Marchand, C.; Marroncle, J.; Martin, A.; Marzec, J.; Matousek, J.; Matsuda, H.; Matsuda, T.; Menon, G.; Meshcheryakov, G.; Meyer, W.; Michigami, T.; Mikhailov, Yu. V.; Miyachi, Y.; Moinester, M. A.; Nagaytsev, A.; Nagel, T.; Nerling, F.; Neubert, S.; Neyret, D.; Nikolaenko, V. I.; Novy, J.; Nowak, W.-D.; Nunes, A. S.; Olshevsky, A. G.; Orlov, I.; Ostrick, M.; Panknin, R.; Panzieri, D.; Parsamyan, B.; Paul, S.; Pesaro, G.; Pesaro, V.; Peshekhonov, D. V.; Pires, C.; Platchkov, S.; Pochodzalla, J.; Polyakov, V. A.; Pretz, J.; Quaresma, M.; Quintans, C.; Ramos, S.; Regali, C.; Reicherz, G.; Reymond, J.-M.; Rocco, E.; Rossiyskaya, N. S.; Rousse, J.-Y.; Ryabchikov, D. I.; Rychter, A.; Samartsev, A.; Samoylenko, V. D.; Sandacz, A.; Sarkar, S.; Savin, I. A.; Sbrizzai, G.; Schiavon, P.; Schill, C.; Schlüter, T.; Schmidt, K.; Schmieden, H.; Schönning, K.; Schopferer, S.; Schott, M.; Shevchenko, O. Yu.; Silva, L.; Sinha, L.; Sirtl, S.; Slunecka, M.; Sosio, S.; Sozzi, F.; Srnka, A.; Steiger, L.; Stolarski, M.; Sulc, M.; Sulej, R.; Suzuki, H.; Szabelski, A.; Szameitat, T.; Sznajder, P.; Takekawa, S.; Terça, G.; Wolbeek, J. ter; Tessaro, S.; Tessarotto, F.; Thibaud, F.; Tskhay, V.; Uhl, S.; Uman, I.; Virius, M.; Wang, L.; Weisrock, T.; Weitzel, Q.; Wilfert, M.; Windmolders, R.; Wollny, H.; Zaremba, K.; Zavertyaev, M.; Zemlyanichkina, E.; Ziembicki, M.; Zink, A.

    2015-04-01

    The main characteristics of the COMPASS experimental setup for physics with hadron beams are described. This setup was designed to perform exclusive measurements of processes with several charged and/or neutral particles in the final state. Making use of a large part of the apparatus that was previously built for spin structure studies with a muon beam, it also features a new target system as well as new or upgraded detectors. The hadron setup is able to operate at the high incident hadron flux available at CERN. It is characterised by large angular and momentum coverages, large and nearly flat acceptances, and good two and three-particle mass resolutions. In 2008 and 2009 it was successfully used with positive and negative hadron beams and with liquid hydrogen and solid nuclear targets. This paper describes the new and upgraded detectors and auxiliary equipment, outlines the reconstruction procedures used, and summarises the general performance of the setup.

  17. The COMPASS setup for physics with hadron beams

    The main characteristics of the COMPASS experimental setup for physics with hadron beams are described. This setup was designed to perform exclusive measurements of processes with several charged and/or neutral particles in the final state. Making use of a large part of the apparatus that was previously built for spin structure studies with a muon beam, it also features a new target system as well as new or upgraded detectors. The hadron setup is able to operate at the high incident hadron flux available at CERN. It is characterised by large angular and momentum coverages, large and nearly flat acceptances, and good two and three-particle mass resolutions. In 2008 and 2009 it was successfully used with positive and negative hadron beams and with liquid hydrogen and solid nuclear targets. This paper describes the new and upgraded detectors and auxiliary equipment, outlines the reconstruction procedures used, and summarises the general performance of the setup

  18. Scaling of membrane-type locally resonant acoustic metamaterial arrays.

    Naify, Christina J; Chang, Chia-Ming; McKnight, Geoffrey; Nutt, Steven R

    2012-10-01

    Metamaterials have emerged as promising solutions for manipulation of sound waves in a variety of applications. Locally resonant acoustic materials (LRAM) decrease sound transmission by 500% over acoustic mass law predictions at peak transmission loss (TL) frequencies with minimal added mass, making them appealing for weight-critical applications such as aerospace structures. In this study, potential issues associated with scale-up of the structure are addressed. TL of single-celled and multi-celled LRAM was measured using an impedance tube setup with systematic variation in geometric parameters to understand the effects of each parameter on acoustic response. Finite element analysis was performed to predict TL as a function of frequency for structures with varying complexity, including stacked structures and multi-celled arrays. Dynamic response of the array structures under discrete frequency excitation was investigated using laser vibrometry to verify negative dynamic mass behavior. PMID:23039544

  19. Set-up for a quantitative RIA

    The diagnostic system serves for the two-stage radioimmuno assay of serum ferritin from human blood samples. The device for the quantitative assay incorporates a ferritin antibody, a grab with which to seize this body, a support for the grab, and a reaction chamber and a test tube. The grab has a handling section and a grabbing section with three attachments. The support accomodates the oblong handling section. This handle facilitates turning of the body and prevents contact with and contamination, respectively of the pathologist or laboratory technician. (DG)

  20. Setup for the Nuclotron beam time structure measurements

    Isupov, A. Yu.; Ladygin, V. P.; Reznikov, S. G.

    2015-01-01

    The setups for precise measurements of the time structure of Nuclotron internal and slowly extracted beams are described in both hardware and software aspects. The CAMAC hardware is based on the use of the standard CAMAC modules developed and manufactured at JINR. The data acquisition system software is implemented using the ngdp framework under the Unix-like operating system (OS) FreeBSD to allow the easy network distribution of the online data. It is demonstrated that the described setups a...