WorldWideScience

Sample records for acoustic measuring instruments

  1. Hydrothermal vent flow and turbulence measurements with acoustic scintillation instrumentation

    Science.gov (United States)

    di Iorio, D.; Xu, G.

    2009-12-01

    Acoustically derived measurements of hydrothermal vent flow and turbulence were obtained from the active black smoker Dante in the Main Endeavour vent field, using scintillation analysis from one-way transmissions. The scintillation transmitter and receiver array formed a 93 m acoustic path through the buoyant plume 20 m above the structure. The acoustic path was parallel to the valley sidewall where the M2 tidal currents are approximately aligned along ridge due to topographic steering by the valley walls and hence most of the plume displacement is expected to occur along the acoustic path. On one deployment, data were collected for 6.5 weeks and vertical velocities range from 0.1 to 0.2 m/s showing a strong dependence on the spring/neap tidal cycle. The refractive index fluctuations which can be paramaterized in terms of the root-mean-square temperature fluctuations also shows a strong tidal modulation during spring tide.

  2. Field evaluation of boat-mounted acoustic Doppler instruments used to measure streamflow

    Science.gov (United States)

    Mueller, D.S.

    2003-01-01

    The use of instruments based on the Doppler principle for measuring water velocity and computing discharge is common within the U.S. Geological Survey (USGS). The instruments and software have changed appreciably during the last 5 years; therefore, the USGS has begun field validation of the instruments used to make discharge measurements from a moving boat. Instruments manufactured by SonTek/YSI and RD Instruments, Inc. were used to collect discharge data at five different sites. One or more traditional discharge measurements were made using a Price AA current meter and standard USGS procedures concurrent with the acoustic instruments at each site. Discharges measured with the acoustic instruments were compared with discharges measured with Price AA current meters and the USGS stage-discharge rating for each site. The mean discharges measured by each acoustic instrument were within 5 percent of the Price AA-based measurement and (or) discharge from the stage-discharge rating.

  3. Complete velocity distribution in river cross-sections measured by acoustic instruments

    Science.gov (United States)

    Cheng, R.T.; Gartner, J.W.

    2003-01-01

    To fully understand the hydraulic properties of natural rivers, velocity distribution in the river cross-section should be studied in detail. The measurement task is not straightforward because there is not an instrument that can measure the velocity distribution covering the entire cross-section. Particularly, the velocities in regions near the free surface and in the bottom boundary layer are difficult to measure, and yet the velocity properties in these regions play the most significant role in characterizing the hydraulic properties. To further characterize river hydraulics, two acoustic instruments, namely, an acoustic Doppler current profiler (ADCP), and a "BoogieDopp" (BD) were used on fixed platforms to measure the detailed velocity profiles across the river. Typically, 20 to 25 stations were used to represent a river cross-section. At each station, water velocity profiles were measured independently and/or concurrently by an ADCP and a BD. The measured velocity properties were compared and used in computation of river discharge. In a tow-tank evaluation of a BD, it has been confirmed that BD is capable of measuring water velocity at about 11 cm below the free-surface. Therefore, the surface velocity distribution across the river was extracted from the BD velocity measurements and used to compute the river discharge. These detailed velocity profiles and the composite velocity distribution were used to assess the validity of the classic theories of velocity distributions, conventional river discharge measurement methods, and for estimates of channel bottom roughness.

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

    Data.gov (United States)

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

  5. Use of Acoustic Doppler Instruments for Measuring Discharge in Streams with Appreciable Sediment Transport

    Science.gov (United States)

    Mueller, D.S.

    2002-01-01

    The use of Acoustic Doppler current profilers (ADCP) for measuring discharge in streams with sediment transport was discussed. The studies show that the acoustic frequency of an ADCP in combination with the sediment transport characteristics in a river causes the ADCP bottom-tracking algorithms to detect a moving bottom. A moving bottom causes bottom-tracking-referenced water velocities and discharges to be biased low. The results also show that the use of differential global positioning system (DGPS) data allows accurate measurement of water velocities and discharges in such cases.

  6. Design and Instrumentation of a Measurement and Calibration System for an Acoustic Telemetry System

    Directory of Open Access Journals (Sweden)

    Zhiqun Deng

    2010-03-01

    Full Text Available The Juvenile Salmon Acoustic Telemetry System (JSATS is an active sensing technology developed by the U.S. Army Corps of Engineers, Portland District, for detecting and tracking small fish. It is used primarily for evaluating behavior and survival of juvenile salmonids migrating through the Federal Columbia River Power System to the Pacific Ocean. It provides critical data for salmon protection and development of more “fish-friendly” hydroelectric facilities. The objective of this study was to design and build a Measurement and Calibration System (MCS for evaluating the JSATS components, because the JSATS requires comprehensive acceptance and performance testing in a controlled environment before it is deployed in the field. The MCS consists of a reference transducer, a water test tank lined with anechoic material, a motion control unit, a reference receiver, a signal conditioner and amplifier unit, a data acquisition board, MATLAB control and analysis interface, and a computer. The fully integrated MCS has been evaluated successfully at various simulated distances and using different encoded signals at frequencies within the bandwidth of the JSATS transmitter. The MCS provides accurate acoustic mapping capability in a controlled environment and automates the process that allows real-time measurements and evaluation of the piezoelectric transducers, sensors, or the acoustic fields. The MCS has been in use since 2009 for acceptance and performance testing of, and further improvements to, the JSATS.

  7. Design and instrumentation of a measurement and calibration system for an acoustic telemetry system.

    Science.gov (United States)

    Deng, Zhiqun; Weiland, Mark; Carlson, Thomas; Eppard, M Brad

    2010-01-01

    The Juvenile Salmon Acoustic Telemetry System (JSATS) is an active sensing technology developed by the U.S. Army Corps of Engineers, Portland District, for detecting and tracking small fish. It is used primarily for evaluating behavior and survival of juvenile salmonids migrating through the Federal Columbia River Power System to the Pacific Ocean. It provides critical data for salmon protection and development of more "fish-friendly" hydroelectric facilities. The objective of this study was to design and build a Measurement and Calibration System (MCS) for evaluating the JSATS components, because the JSATS requires comprehensive acceptance and performance testing in a controlled environment before it is deployed in the field. The MCS consists of a reference transducer, a water test tank lined with anechoic material, a motion control unit, a reference receiver, a signal conditioner and amplifier unit, a data acquisition board, MATLAB control and analysis interface, and a computer. The fully integrated MCS has been evaluated successfully at various simulated distances and using different encoded signals at frequencies within the bandwidth of the JSATS transmitter. The MCS provides accurate acoustic mapping capability in a controlled environment and automates the process that allows real-time measurements and evaluation of the piezoelectric transducers, sensors, or the acoustic fields. The MCS has been in use since 2009 for acceptance and performance testing of, and further improvements to, the JSATS. PMID:22319288

  8. REMORA 3: The first instrumented fuel experiment with on-line gas composition measurement by acoustic sensor

    Energy Technology Data Exchange (ETDEWEB)

    Lambert, T.; Muller, E.; Federici, E. [CEA - Nuclear Energy Div., DEN - Fuel Research Dept. - Cadarache, F-13108 Saint-Paul-Lez-Durance (France); Rosenkrantz, E.; Ferrandis, J. Y. [CNRS - Univ. Montpellier 2, Southern Electronic Inst., UMR 5214, F-34095 Montpellier (France); Tiratay, X.; Silva, V. [CEA, Nuclear Energy Div., DEN, Nuclear Reactors and Facilities Dept., F-91191 Gif Sur Yvette (France); Machard, D. [EDF, SEPTEN, F-69628 Villeurbanne (France); Trillon, G. [AREVA-NP, F-69456 Lyon (France)

    2011-07-01

    With the aim to improve the knowledge of nuclear fuel behaviour, the development of advanced instrumentation used during in-pile experiments in Material Testing Reactor (MTR) is necessary. To obtain data on high Burn-Up MOX fuel performance under transient operating conditions, especially in order to differentiate between the kinetics of fission gas and helium releases and to acquire data on the degradation of the fuel conductivity, a highly instrumented in-pile experiment called REMORA 3 has been conducted by CEA and IES (Southern Electronic Inst. - CNRS - Montpellier 2 Univ.). A rodlet extracted from a fuel rod base irradiated for five cycles in a French EDF commercial PWR has been re-instrumented with a fuel centerline thermocouple, a pressure transducer and an advanced acoustic sensor. This latter, patented by CEA and IES, is 1 used in addition to pressure measurement to determine the composition of the gases located in the free volume and the molar fractions of fission gas and helium. This instrumented fuel rodlet has been re-irradiated in a specific rig, GRIFFONOS, located in the periphery of the OSIRIS experimental reactor core at CEA Saclay. First of all, an important design stage and test phases have been performed before the irradiation in order to optimize the response and the accuracy of the sensors: - To control the influence of the temperature on the acoustic sensor behaviour, a thermal mock-up has been built. - To determine the temperature of the gas located in the acoustic cavity as a function of the coolant temperature, and the average temperature of the gases located in the rodlet free volume as a function of the linear heat rate, thermal calculations have been achieved. The former temperature is necessary to calculate the molar fractions of the gases and the latter is used to calculate the total amount of released gas from the internal rod pressure measurements. - At the end of the instrumented rod manufacturing, specific internal free volume and

  9. Acoustic emission measurements of PWR weld material with inserted defects using advanced instrumentation

    International Nuclear Information System (INIS)

    Twenty-one steel tensile specimens containing realistic welding defects have been monitored for acoustic emission during loading to failure. A new design of broad frequency bandwidth point contact transducer was used and the resulting signal captured using a high speed transient recording system. The data was analysed using the techniques of statistical pattern recognition to separate different types of signals. The results show that it is possible to separate true acoustic emission from background noise and to distinguish between certain types of defect. (author)

  10. Acoustics, computers and measurements

    Science.gov (United States)

    Truchard, James J.

    2003-10-01

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

  11. Design and Instrumentation of a Measurement and Calibration System for an Acoustic Telemetry System

    OpenAIRE

    Zhiqun Deng; Mark Weiland; Thomas Carlson; M. Brad Eppard

    2010-01-01

    The Juvenile Salmon Acoustic Telemetry System (JSATS) is an active sensing technology developed by the U.S. Army Corps of Engineers, Portland District, for detecting and tracking small fish. It is used primarily for evaluating behavior and survival of juvenile salmonids migrating through the Federal Columbia River Power System to the Pacific Ocean. It provides critical data for salmon protection and development of more “fish-friendly” hydroelectric facilities. The objective of this study was ...

  12. Correction of Teledyne Acoustic Doppler Current Profiler (ADCP) Bottom-Track Range Measurements for Instrument Pitch and Roll

    CERN Document Server

    Woodgate, Rebecca A

    2011-01-01

    The Workhorse Acoustic Doppler Current Profiler (ADCP) manufactured by Teledyne RD Instruments (RDI) uses a "Bottom-Tracking" algorithm to yield data intended to represent distance to the bottom. However, current RDI software processing does not take into account the pitch and roll of the instrument. This technical note outlines post-deployment computations required to correct the reported Bottom-Track Ranges for instrument pitch and roll in the scenario where the ADCP is upward-looking with Bottom-Tracking being used to estimate distance to the surface.

  13. The Overtone Fiddle: an Actuated Acoustic Instrument

    DEFF Research Database (Denmark)

    Overholt, Daniel

    2011-01-01

    The Overtone Fiddle is a new violin-family instrument that incorporates electronic sensors, integrated DSP, and physical actuation of the acoustic body. An embedded tactile sound transducer creates extra vibrations in the body of the Overtone Fiddle, allowing performer control and sensation via...

  14. Instrument de mesure en acoustic

    DEFF Research Database (Denmark)

    Tarnow, Viggo; Jacobsen, Finn

    2008-01-01

    The function of measuring microphones and sound intensity measuring devices is presented for scientific personel.......The function of measuring microphones and sound intensity measuring devices is presented for scientific personel....

  15. Investigating oboe manufacturing consistency by comparing the acoustical properties of five nominally identical instruments

    OpenAIRE

    MAMOU-MANI, Adrien; Sharp, David; Meurisse, Thibaut; Ring, William

    2010-01-01

    For large-scale musical instrument makers, the ability to produce instruments with exactly the same playing characteristics is a constant aim. Modern acoustical measurement techniques (such as acoustic pulse reflectometry and input impedance measurement methods) together with psychoacoustical testing, can help this goal be reached. This paper investigates the issue of instrument manufacturing consistency by comparing the acoustical properties and the perceptual qualities of five Howarth S10 s...

  16. 声悬浮及声速测定实验仪的设计%Acoustic levitation and design of sound velocity measurement instrument

    Institute of Scientific and Technical Information of China (English)

    马国利

    2012-01-01

    《声速测定》是大学物理实验中比较普遍的一个综合性实验.在声速测定实验仪的基础上,改进了信号源,并制作了声悬浮配件,使其实现既可以用多种方式测量声速,又可演示声悬浮实验现象.声悬浮及声速测定实验仪悬浮稳定性强,声速测定准确,仪器造价低,使用方便,这样设计节省了实验室资源和空间.%The measurement of sound velocity is a commonly comprehensive experiment among university physics experiments. Our design idea is to, based on the original equipment, improve the signal source and make acoustic levitation parts so as to measure sound velocity in different ways; and demonstrate the experimental phenomena of acoustic levitation. The sound velocity measurement experiment instrument has strong levitation stability, accurate sound velocity measurement, low cost and convenient applications. This design saves laboratory resources and space.

  17. The Overtone Fiddle: an Actuated Acoustic Instrument

    OpenAIRE

    Overholt, Daniel

    2011-01-01

    The Overtone Fiddle is a new violin-family instrument that incorporates electronic sensors, integrated DSP, and physical actuation of the acoustic body. An embedded tactile sound transducer creates extra vibrations in the body of the Overtone Fiddle, allowing performer control and sensation via both traditional violin techniques, as well as extended playing techniques that incorporate shared man/machine control of the resulting sound. A magnetic pickup system is mounted to the end of the fidd...

  18. INSTRUMENTATION FOR SURVEYING ACOUSTIC SIGNALS IN NATURAL GAS TRANSMISSION LINES

    Energy Technology Data Exchange (ETDEWEB)

    John L. Loth; Gary J. Morris; George M. Palmer; Richard Guiler; Deepak Mehra

    2003-09-01

    In the U.S. natural gas is distributed through more than one million miles of high-pressure transmission pipelines. If all leaks and infringements could be detected quickly, it would enhance safety and U.S. energy security. Only low frequency acoustic waves appear to be detectable over distances up to 60 km where pipeline shut-off valves provide access to the inside of the pipeline. This paper describes a Portable Acoustic Monitoring Package (PAMP) developed to record and identify acoustic signals characteristic of: leaks, pump noise, valve and flow metering noise, third party infringement, manual pipeline water and gas blow-off, etc. This PAMP consists of a stainless steel 1/2 inch NPT plumbing tree rated for use on 1000 psi pipelines. Its instrumentation is designed to measure acoustic waves over the entire frequency range from zero to 16,000 Hz by means of four instruments: (1) microphone, (2) 3-inch water full range differential pressure transducer with 0.1% of range sensitivity, (3) a novel 3 inch to 100 inch water range amplifier, using an accumulator with needle valve and (4) a line-pressure transducer. The weight of the PAMP complete with all accessories is 36 pounds. This includes a remote control battery/switch box assembly on a 25-foot extension chord, a laptop data acquisition computer on a field table and a sun shield.

  19. Spectroelectrochemical Instrument Measures TOC

    Science.gov (United States)

    Kounaves, Sam

    2011-01-01

    A spectroelectrochemical instrument has been developed for measuring the total organic carbon (TOC) content of an aqueous solution. Measurements of TOC are frequently performed in environmental, clinical, and industrial settings. Until now, techniques for performing such measurements have included, various ly, the use of hazardous reagents, ultraviolet light, or ovens, to promote reactions in which the carbon contents are oxidized. The instrument now being developed is intended to be a safer, more economical means of oxidizing organic carbon and determining the TOC levels of aqueous solutions and for providing a low power/mass unit for use in planetary missions.

  20. Instrument Measures Ocular Counterrolling

    Science.gov (United States)

    Levitan, Barry M.; Reschke, Millard F.; Spector, Lawrence N.

    1991-01-01

    Compact, battery-powered, noninvasive unit replaces several pieces of equipment and operator. Instrument that looks like pair of goggles with small extension box measures ocular counterrotation. Called "otolith tilt-translation reinterpretation" (OTTR) goggles, used in studies of space motion sickness. Also adapted to use on Earth and determine extent of impairment in patients who have impaired otolith functions.

  1. Feedback control of acoustic musical instruments: collocated control using physical analogs.

    Science.gov (United States)

    Berdahl, Edgar; Smith, Julius O; Niemeyer, Günter

    2012-01-01

    Traditionally, the average professional musician has owned numerous acoustic musical instruments, many of them having distinctive acoustic qualities. However, a modern musician could prefer to have a single musical instrument whose acoustics are programmable by feedback control, where acoustic variables are estimated from sensor measurements in real time and then fed back in order to influence the controlled variables. In this paper, theory is presented that describes stable feedback control of an acoustic musical instrument. The presentation should be accessible to members of the musical acoustics community who may have limited or no experience with feedback control. First, the only control strategy guaranteed to be stable subject to any musical instrument mobility is described: the sensors and actuators must be collocated, and the controller must emulate a physical analog system. Next, the most fundamental feedback controllers and the corresponding physical analog systems are presented. The effects that these controllers have on acoustic musical instruments are described. Finally, practical design challenges are discussed. A proof explains why changing the resonance frequency of a musical resonance requires much more control power than changing the decay time of the resonance.

  2. Studies of a full-scale mechanical prototype line for the ANTARES neutrino telescope and tests of a prototype instrument for deep-sea acoustic measurements

    Energy Technology Data Exchange (ETDEWEB)

    Ageron, M. [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); Aguilar, J.A. [IFIC-Instituto de Fisica Corpuscular, Edificios Investigacion de Paterna, CSIC-Universitat de Valencia, Apdo. de Correos 22085, 46071 Valencia (Spain); Albert, A. [GRPHE-Groupe de Recherche en Physique des Hautes Energies, Universite de Haute Alsace, 61 Rue Albert Camus, 68093 Mulhouse Cedex (France); Ameli, F. [Dipartimento di Fisica dell' Universita ' La Sapienza' e Sezione INFN, P.le Aldo Moro 2, 00185 Roma (Italy); Anghinolfi, M. [Dipartimento di Fisica dell' Universita e Sezione INFN, Via Dodecaneso 33, 16146 Genova (Italy); Anton, G. [Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Physikalisches Institut, Erwin-Rommel-Str. 1, D-91058 Erlangen (Germany); Anvar, S.; Ardellier-Desages, F. [DSM/DAPNIA-Direction des Sciences de la Matiere, Laboratoire de Recherche sur les lois Fondamentales de l' Univers, CEA Saclay, 91191 Gif-sur-Yvette Cedex (France); Aslanides, E.; 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, Physikalisches Institut, Erwin-Rommel-Str. 1, D-91058 Erlangen (Germany); Barbarito, E. [Dipartimento Interateneo di Fisica e Sezione INFN, Via E. Orabona 4, 70126 Bari (Italy); Basa, S. [LAM-Laboratoire d' Astrophysique de Marseille, CNRS/INSU et Universite de Provence, Traverse du Siphon-Les Trois Lucs, BP 8, 13012 Marseille Cedex 12 (France); Battaglieri, M. [Dipartimento di Fisica dell' Universita e Sezione INFN, Via Dodecaneso 33, 16146 Genova (Italy); Bazzotti, M.; Becherini, Y. [Dipartimento di Fisica dell' Universita e Sezione INFN, Viale Berti Pichat 6/2, 40127 Bologna (Italy)] (and others)

    2007-11-01

    A full-scale mechanical prototype line was deployed to a depth of 2500 m to test the leak tightness of the electronics containers and the pressure-resistant properties of an electromechanical cable under evaluation for use in the ANTARES deep-sea neutrino telescope. During a month-long immersion study, line parameter data were taken using miniature autonomous data loggers and shore-based optical time domain reflectometry. Details of the mechanical prototype line, the electromechanical cable and data acquisition are presented. Data taken during the immersion study revealed deficiencies in the pressure resistance of the electromechanical cable terminations at the entry points to the electronics containers. The improvements to the termination, which have been integrated into subsequent detection lines, are discussed. The line also allowed deep-sea acoustic measurements with a prototype hydrophone system. The technical setup of this system is described, and the first results of the data analysis are presented.

  3. Measurement, instrumentation, and sensors handbook

    CERN Document Server

    Eren, Halit

    2014-01-01

    The Second Edition of the bestselling Measurement, Instrumentation, and Sensors Handbook brings together all aspects of the design and implementation of measurement, instrumentation, and sensors. Reflecting the current state of the art, it describes the use of instruments and techniques for performing practical measurements in engineering, physics, chemistry, and the life sciences and discusses processing systems, automatic data acquisition, reduction and analysis, operation characteristics, accuracy, errors, calibrations, and the incorporation of standards for control purposes. Organized acco

  4. Generation of a reference radiation pattern of string instruments using automatic excitation and acoustic centering.

    Science.gov (United States)

    Shabtai, Noam R; Behler, Gottfried; Vorländer, Michael

    2015-11-01

    Radiation patterns of musical instruments are important for the understanding of music perception in concert halls, and may be used to improve the plausibility of virtual acoustic systems. Many attempts have been performed to measure the spatial response of musical instruments using surrounding spherical microphone arrays with a limited number of microphones. This work presents a high-resolution spatial sampling of the radiation pattern of an electrically excited violin, and addresses technical problems that arise due to mechanical reasons of the excitation apparatus using acoustic centering.

  5. Explicit Mapping of Acoustic Regimes For Wind Instruments

    CERN Document Server

    Missoum, Samy; Doc, Jean-Baptiste

    2014-01-01

    This paper proposes a methodology to map the various acoustic regimes of wind instruments. The maps can be generated in a multi-dimensional space consisting of design, control parameters, and initial conditions. The bound- aries of the maps are obtained explicitly in terms of the parameters using a support vector machine (SVM) classifier as well as a dedicated adaptive sam- pling scheme. The approach is demonstrated on a simplified clarinet model for which several maps are generated based on different criteria. Examples of computation of the probability of occurrence of a specific acoustic regime are also provided. In addition, the approach is demonstrated on a design optimization example for optimal intonation.

  6. Instrument measures cloud cover

    Science.gov (United States)

    Laue, E. G.

    1981-01-01

    Eight solar sensing cells comprise inexpensive monitoring instrument. Four cells always track Sun while other four face sky and clouds. On overcast day, cloud-irradiance sensors generate as much short-circuit current as Sun sensor cells. As clouds disappear, output of cloud sensors decreases. Ratio of two sensor type outputs determines fractional cloud cover.

  7. Instrument measures dynamic pressure fluctuations

    Science.gov (United States)

    Coats, J. W.; Penko, P. E.; Reshotko, M.

    1977-01-01

    Pressure probe instrument, incorporating "infinite line" principle, can be used to remotely measure dynamic pressure fluctuations in hot high-pressure environemnts too severe for sensors. System is designed and can be utilized for measurements in core of operating turbofan engine.

  8. Instrument Measures Shift In Focus

    Science.gov (United States)

    Steimle, Lawrence J.

    1992-01-01

    Optical components tested at wavelengths from ultraviolet to infrared. Focus-shift-measuring instrument easy to use. Operated in lighted room, without having to make delicate adjustments while peering through microscope. Measures distance along which focal point of converging beam of light shifted by introduction of nominally plane parallel optical component into beam. Intended primarily for measuring focus shifts produced by windows and filters at wavelengths from 120 to 1,100 nanometers. Portable, compact, and relatively inexpensive for degree of precision.

  9. Introduction to instrumentation and measurements

    CERN Document Server

    Northrop, Robert B

    2014-01-01

    Weighing in on the growth of innovative technologies, the adoption of new standards, and the lack of educational development as it relates to current and emerging applications, the third edition of Introduction to Instrumentation and Measurements uses the authors' 40 years of teaching experience to expound on the theory, science, and art of modern instrumentation and measurements (I&M). What's New in This Edition: This edition includes material on modern integrated circuit (IC) and photonic sensors, micro-electro-mechanical (MEM) and nano-electro-mechanical (NEM) sensors, chemical and radiation sensors, signal conditioning, noise, data interfaces, and basic digital signal processing (DSP), and upgrades every chapter with the latest advancements. It contains new material on the designs of micro-electro-mechanical (MEMS) sensors, adds two new chapters on wireless instrumentation and microsensors, and incorporates extensive biomedical examples and problems. Containing 13 chapters, this third edition: Describ...

  10. USE OF SCALE MODELING FOR ARCHITECTURAL ACOUSTIC MEASUREMENTS

    OpenAIRE

    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...

  11. Mobile Instruments Measure Atmospheric Pollutants

    Science.gov (United States)

    2009-01-01

    As a part of NASA's active research of the Earth s atmosphere, which has included missions such as the Atmospheric Laboratory of Applications and Science (ATLAS, launched in 1992) and the Total Ozone Mapping Spectrometer (TOMS, launched on the Earth Probe satellite in 1996), the Agency also performs ground-based air pollution research. The ability to measure trace amounts of airborne pollutants precisely and quickly is important for determining natural patterns and human effects on global warming and air pollution, but until recent advances in field-grade spectroscopic instrumentation, this rapid, accurate data collection was limited and extremely difficult. In order to understand causes of climate change and airborne pollution, NASA has supported the development of compact, low power, rapid response instruments operating in the mid-infrared "molecular fingerprint" portion of the electromagnetic spectrum. These instruments, which measure atmospheric trace gases and airborne particles, can be deployed in mobile laboratories - customized ground vehicles, typically - to map distributions of pollutants in real time. The instruments must be rugged enough to operate rapidly and accurately, despite frequent jostling that can misalign, damage, or disconnect sensitive components. By measuring quickly while moving through an environment, a mobile laboratory can correlate data and geographic points, revealing patterns in the environment s pollutants. Rapid pollutant measurements also enable direct determination of pollutant sources and sinks (mechanisms that remove greenhouse gases and pollutants), providing information critical to understanding and managing atmospheric greenhouse gas and air pollutant concentrations.

  12. An Instrument to Measure Anomia.

    Science.gov (United States)

    Moore, Allen B.

    1980-01-01

    Four hundred and eighty-six disadvantaged adults from North Carolina were the subjects in a study that factor-analyzed three instruments designed to measure anomia, yielding a 12-item unidimensional scale. (The refined combination scale is presented as of potential usefulness for research on the effects of educational intervention on anomia.) (LRA)

  13. Measuring instruments of corporate reputation

    Directory of Open Access Journals (Sweden)

    Damir Grgić

    2008-12-01

    Full Text Available The subject of this paper is focused on the instruments for the measurement of corporate reputation. Recent research of the elements which influence the success of a company shows a growing interest in intangible values. Corporate reputation itself has been identified as one of the key intangible assets which create the company’s added value. Understanding of the importance of corporate reputation has been determined as a significant component of the company’s competitiveness, that is, of its competitive edge. Reputation is a normal part of our life and an integral part of our society. Our interest in the honesty and integrity of others is firmly established in all cultures and nowadays the focus of this interest is switching increasingly on companies. Corporate reputation can be acquired by means of strong, well-developed strategies, which are crucial for the opinion of stakeholders regarding future stability and competitive sustainability of the company. On the other hand, it should be emphasized that in order to manage it, corporate reputation has to be measured first. However, although the concept of corporate reputation is universally accepted and its significance has been recognized especially in the last two decades, the process of its measurement is still at an early stage and there is no universally accepted instrument for its measurement. Therefore, the author of this paper gives an overview of the instruments used for the measurement of corporate reputation which have gained a foothold through former practical usage.

  14. Radioisotope-applied measuring instruments

    International Nuclear Information System (INIS)

    Fuji Electric developed a new type detector for gamma thickness gauges, inner-mill housing gamma thickness gauges at hot plate mills and tube-wall thickness gauges at hot seamless tube mills. This detector attained much higher gamma counting and much lower drift than our former detectors. We plan to apply this detector to our new type thickness gauges and also renewal of now working thickness gauges at customer's site. In addition, we developed a soil mass measuring instrument for on-line measurement of cutting soil mass in a waste water tube in shield tunneling. This instrument is free from legal control and can be used in every field of civil engineering. (author)

  15. Instrumentation for atmospheric ion measurements

    CERN Document Server

    Aplin, K L

    2005-01-01

    Small ions are part of the atmospheric aerosol spectrum, and study of ion-aerosol interactions is fundamental in atmospheric physics. Air ion physics and instrumentation are reviewed, including the historical context. A miniaturised Gerdien condenser for ion measurement, operating in situ to minimise inlet errors, is described. Two operating modes using independent current and voltage decay measurements are employed. A more sophisticated self-calibrating and fully programmable ion mobility spectrometer (PIMS) based on the same principles, is also discussed. Detailed analysis of error terms and application of new technology is demonstrated to greatly improve its capability. Self-consistent experimental approaches, including ionisation and ion concentration instruments, are used for calibration. In developing and characterising the individual components of the PIMS, favourable and unfavourable operating regimes are identified: this approach can also be applied to other aspiration ion counting techniques. Use of...

  16. Measuring instruments of corporate reputation

    OpenAIRE

    Damir Grgić

    2008-01-01

    The subject of this paper is focused on the instruments for the measurement of corporate reputation. Recent research of the elements which influence the success of a company shows a growing interest in intangible values. Corporate reputation itself has been identified as one of the key intangible assets which create the company’s added value. Understanding of the importance of corporate reputation has been determined as a significant component of the company’s competitiveness, that is, of its...

  17. Compact Instruments Measure Heat Potential

    Science.gov (United States)

    2009-01-01

    Based in Huntsville, Alabama, AZ Technology Inc. is a woman- and veteran-owned business that offers expertise in electromechanical-optical design and advanced coatings. AZ Technology has received eight Small Business Innovation Research (SBIR) contracts with Marshall Space Flight Center for the development of spectral reflectometers and the measurement of surface thermal properties. The company uses a variety of measurement services and instruments, including the Spectrafire, a portable spectral emissometer it used to assist General Electric with the design of its award-winning Giraffe Warmer for neonatal intensive care units.

  18. Optical measurement of acoustic radiation pressure of the near-field acoustic levitation through transparent object

    CERN Document Server

    Nakamura, Satoshi; Sasao, Yasuhiro; Katsura, Kogure; Naoki, Kondo

    2013-01-01

    It is known that macroscopic objects can be levitated for few to several hundred micrometers by near-field acoustic field and this phenomenon is called near-field acoustic levitation (NFAL). Although there are various experiments conducted to measure integrated acoustic pressure on the object surface, up to now there was no direct method to measure pressure distribution. In this study we measured the acoustic radiation pressure of the near-field acoustic levitation via pressure-sensitive paint.

  19. Simultaneous measurements of room acoustic parameters using different measuring equipment

    DEFF Research Database (Denmark)

    Halmrast, Tor; Gade, Anders Christian; Winsvold, Bjørn

    1996-01-01

    In a cooperation between Stattsbyg, Norway, Norsonic, Norway, and Department of Acoustic Technology, a number of room acoustic parameters have been determined in Oslo Concert Hall. All measurements were carried out on the same day, using the same amplifier, microphone and loudspeaker, and the sam...

  20. Instrumentation for Structure Measurements on Highly Non-equilibrium Materials

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Richard [Argonne National Laboratory (ANL); Benmore, Chris J [Argonne National Laboratory (ANL); Neuefeind, Joerg C [ORNL; Wilding, Martin C [ORNL

    2011-01-01

    Containerless techniques (levitation) completely eliminate contact with the sample. This unique sample environment allows deep supercooling of many liquids and avoids contamination of high temperature melts. Recent experiments at the APS high energy beamline 11 ID-C used aerodynamic levitation with laser beam heating and acoustic levitation with cryogenic cooling. By using these two methods, liquids were studied over much of the temperature range from -40 to +2500 C. This paper briefly describes the instrumentation and its use with an -Si area detector that allows fast, in-situ measurements. Use of the instruments is illustrated with examples of measurements on molten oxides and aqueous materials.

  1. Techniques in audio and acoustic measurement

    Science.gov (United States)

    Kite, Thomas D.

    2003-10-01

    Measurement of acoustic devices and spaces is commonly performed with time-delay spectrometry (TDS) or maximum length sequence (MLS) analysis. Both techniques allow an impulse response to be measured with a signal-to-noise ratio (SNR) that can be traded off against the measurement time. However, TDS suffers from long measurement times because of its linear sweep, while MLS suffers from the corruption of the impulse response by distortion. Recently a logarithmic sweep-based method has been devised which offers high SNR, short measurement times, and the ability to separate the linear impulse response from the impulse responses of distortion products. The applicability of these methods to audio and acoustic measurement will be compared.

  2. Measuring Norwegian dialect distances using acoustic features

    NARCIS (Netherlands)

    Heeringa, Wilbert; Johnson, Keith; Gooskens, Charlotte

    2009-01-01

    Levenshtein distance has become a popular tool for measuring linguistic dialect distances, and has been applied to Irish Gaelic, Dutch, German and other dialect groups. The method, in the current state of the art, depends upon phonetic transcriptions, even when acoustic differences are used the numb

  3. Acoustic Measurement of Potato Cannon Velocity

    Science.gov (United States)

    Courtney, Michael; Courtney, Amy

    2007-01-01

    Potato cannon velocity can be measured with a digitized microphone signal. A microphone is attached to the potato cannon muzzle, and a potato is fired at an aluminum target about 10 m away. Flight time can be determined from the acoustic waveform by subtracting the time in the barrel and time for sound to return from the target. The potato…

  4. Acoustical measurements in ancient Roman theatres

    Science.gov (United States)

    Farnetani, Andrea; Fausti, Patrizio; Pompoli, Roberto; Prodi, Nicola

    2001-05-01

    The Greek and Roman theatres are among the most precious and spectacular items of cultural heritage in the Mediterranean countries. The theatres are famous not only for their impressive architecture, but also for the acoustic qualities. For this reason it is important to consider these theatres as an acoustical heritage and to study their sound field. Within the activities of the ERATO (identification Evaluation and Revival of the Acoustical heritage of ancient Theatres and Odea) project, acoustical measurements were taken in well-preserved ancient Roman theatres at Aspendos (Turkey) and Jerash (Jordan). Roman theatres have an impressive stage building that forms a back wall in the orchestra area, and it was found that, from the analysis of the acoustical parameters, the reverberation time (e.g., 1.7 s at middle frequencies in the theatre of Aspendos) is quite long compared not only with other open-space theatres but also with closed spaces. Contrary to modern halls the clarity is high and this fact, together with a low sound level in most of the seats, gives the sound field a unique character.

  5. The effect of time-variant acoustical properties on orchestral instrument timbres

    Science.gov (United States)

    Hajda, John Michael

    1999-06-01

    The goal of this study was to investigate the timbre of orchestral instrument tones. Kendall (1986) showed that time-variant features are important to instrument categorization. But the relative salience of specific time-variant features to each other and to other acoustical parameters is not known. As part of a convergence strategy, a battery of experiments was conducted to assess the importance of global amplitude envelope, spectral frequencies, and spectral amplitudes. An omnibus identification experiment investigated the salience of global envelope partitions (attack, steady state, and decay). Valid partitioning models should identify important boundary conditions in the evolution of a signal; therefore, these models should be based on signal characteristics. With the use of such a model for sustained continuant tones, the steady-state segment was more salient than the attack. These findings contradicted previous research, which used questionable operational definitions for signal partitioning. For the next set of experiments, instrument tones were analyzed by phase vocoder, and stimuli were created by additive synthesis. Edits and combinations of edits controlled global amplitude envelope, spectral frequencies, and relative spectral amplitudes. Perceptual measurements were made with distance estimation, Verbal Attribute Magnitude Estimation, and similarity scaling. Results indicated that the primary acoustical attribute was the long-time-average spectral centroid. Spectral centroid is a measure of the center of energy distribution for spectral frequency components. Instruments with high values of spectral centroid (bowed strings) sound nasal while instruments with low spectral centroid (flute, clarinet) sound not nasal. The secondary acoustical attribute was spectral amplitude time variance. Predictably, time variance correlated highly with subject ratings of vibrato. The control of relative spectral amplitudes was more salient than the control of global

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

    OpenAIRE

    Vauthrin, Camille

    2015-01-01

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

  7. Numerical Techniques for Acoustic Modelling and Design of Brass Wind Instruments

    OpenAIRE

    Noreland, Daniel

    2003-01-01

    Acoustic horns are used in musical instruments and loudspeakers in order to provide an impedance match between an acoustic source and the surrounding air. The aim of this study is to develop numerical tools for the analysis and optimisation of such horns, with respect to their input impedance spectra. Important effects such as visco-thermal damping and modal conversion are shown to be localised to different parts of a typical brass instrument. This makes it possible to construct hybrid method...

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

    Institute of Scientific and Technical Information of China (English)

    Zhen Luo; Feng Tian; Xiao-Ping Sun

    2007-01-01

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

  9. Acoustics of Korean percussion instruments: Pyeongyeong and pyeonjong

    Science.gov (United States)

    Yoo, Junehee

    2005-11-01

    The pyeongyeong and the pyeonjong have long been cherished as standard instruments in Korean court music. Pyeongyeong is a set of sixteen L-shaped chime stones and pyeonjong is a set of sixteen oval chime bells. To figure out the acoustical properties of the pyeongyeong and the pyeonjong, the vibrational modes are obtained by using FFT analyzers, accelerometer scanning, TV holography, and impact hammer testing. Especially to test the geometry effects on the tuning, the finite element method is introduced. The pyeongyeong covers one and one third octave from 528.6 Hz to 1262.8 Hz. The nominal frequency of the first stone, whangjong, is 528.6 Hz which is 17.6 cents higher than 523.25 Hz, the frequency of the C5 note in the A440 tempered scale. The second mode is tuned to about 1.5 times the nominal frequency, which means the second partial is tuned to be a perfect fifth above the nominal. The third mode is tuned to about 2.3 times the nominal frequency. Mode shapes of a gyeong from three different methods agree with each other. In most cases, the modes seem to be combinations of bending and torsional motion. The calculated results by using the finite element method show that the ratio frequencies of higher modes rise as the vertex angle of a gyeong changes from 90 degrees to 180 degrees. The curvatures of the baseline affect the tuning of the stone, but the effects are smaller than those of the vertex angle. The geometry of the gyeong affects the tuning of the stone. The pyeonjong covers one and one third octave from 267.95 Hz to 634.74 Hz. The nominal frequency of the first bell, whangiong , is 267.95 Hz. The second mode (i.e. (2,0)b) is tuned to about 1.09 times the nominal frequency (i.e. (2,0)a) mode. The third mode (i.e. (3,0)b) is tuned to about 2.62 times the nominal frequency. The fourth mode (3,0), is tuned 2.72 times the nominal frequency, a perfect fourth plus 39 cents above the octave. Mode shapes of the bells, determined by electronic TV holography, are

  10. Acoustic measurement of potato cannon velocity

    CERN Document Server

    Courtney, M; Courtney, Amy; Courtney, Michael

    2006-01-01

    This article describes measurement of potato cannon velocity with a digitized microphone signal. A microphone is attached to the potato cannon muzzle and a potato is fired at an aluminum target about 10 m away. The potato's flight time can be determined from the acoustic waveform by subtracting the time in the barrel and time for sound to return from the target. The potato velocity is simply the flight distance divided by the flight time.

  11. New methods of measuring normal acoustic impedance

    OpenAIRE

    Wayman, James L.

    1984-01-01

    In recent years new methods based on signal processing technical have been developed to measure the normal acoustic impedance of materials. These methods proved to be considerably faster easier to implement than the SRW method rhey replace. Mathematical, hardware and software aspects of these techniques are discussed and results obtained over a frequency range of 200-4000 Hz for several architectural materials are presented. NPS Foundation Research Program http://archive....

  12. Measuring acoustic emissions in an avalanche slope

    Science.gov (United States)

    Reiweger, Ingrid; Schweizer, Jürg

    2014-05-01

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

  13. Acoustic levitation methods for density measurements

    Science.gov (United States)

    Trinh, E. H.; Hsu, C. J.

    1986-01-01

    The capability of ultrasonic levitators operating in air to perform density measurements has been demonstrated. The remote determination of the density of ordinary liquids as well as low density solid metals can be carried out using levitated samples with size on the order of a few millimeters and at a frequency of 20 kHz. Two basic methods may be used. The first one is derived from a previously known technique developed for acoustic levitation in liquid media, and is based on the static equilibrium position of levitated samples in the earth's gravitational field. The second approach relies on the dynamic interaction between a levitated sample and the acoustic field. The first technique appears more accurate (1 percent uncertainty), but the latter method is directly applicable to a near gravity-free environment such as that found in space.

  14. An inexpensive instrument for measuring wave exposure and water velocity

    Science.gov (United States)

    Figurski, J.D.; Malone, D.; Lacy, J.R.; Denny, M.

    2011-01-01

    Ocean waves drive a wide variety of nearshore physical processes, structuring entire ecosystems through their direct and indirect effects on the settlement, behavior, and survivorship of marine organisms. However, wave exposure remains difficult and expensive to measure. Here, we report on an inexpensive and easily constructed instrument for measuring wave-induced water velocities. The underwater relative swell kinetics instrument (URSKI) is a subsurface float tethered by a short (measurements through comparison to velocities measured by an in situ acoustic Doppler velocimeter and those predicted by a standard swell model, and we evaluated how the dimensions of the devices, its buoyancy, and sampling frequency can be modified for use in a variety of environments.

  15. Acoustical study of the playing characteristics of brass wind instruments

    OpenAIRE

    Logie, Shona Mary

    2013-01-01

    When assessing the quality of a brass instrument the player must consider a number of factors, the main consideration being the playability of the chosen instrument. The playability of an instrument is a broad term used to describe how well the instrument plays; this includes how in tune the resonant modes are, how easy it is to start and move between notes, how easy it is to bend notes and the degree of spectral enrichment during a crescendo that is able to be produced. The...

  16. Measurement of acoustic attenuation in South Pole ice

    NARCIS (Netherlands)

    Abbasi, R.; Abdou, Y.; 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.B.; Beattie, K.; Beatty, J.J.; Bechet, S.; Becker, J.K.; Becker, K.H.; Benabderrahmane, M.L.; Berdermann, J.; Berghaus, P.; Berley, D.; Bernardini, E.; Bertrand, D.; Besson, D.Z.; Bissok, M.; Blaufuss, E.; Boersma, D.J.; Bohm, C.; Boser, S.; Botner, O.; Bradley, L.; Braun, J.; 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.; Clercq, C. De; Demirors, L.; Depaepe, O.; Descamps, F.; Desiati, P.; Vries-Uiterweerd, G. de; DeYoung, T.; Diaz-Velez, J.C.; Dreyer, J.; Dumm, J.P.; Duvoort, M.R.; Ehrlich, R.; Eisch, J.; Ellsworth, R.W.; Engdegard, O.; Euler, S.; Evenson, P.A.; Fadiran, O.; Fazely, A.R.; Feusels, T.; Filimonov, K.; Finley, C.; Foerster, M.M.; Fox, B.D.; Franckowiak, A.; Franke, R.; Gaisser, T.K.; Gallagher, J.; Ganugapati, R.; Geisler, M.; Gerhardt, L.; Gladstone, L.; Glusenkamp, T.; Goldschmidt, A.; Goodman, J.A.; Grant, D.; Griesel, T.; Gross, A.; Grullon, S.; Gunasingha, R.M.; Gurtner, M.; Gustafsson, L.; Ha, C.; Hallgren, A.; Halzen, F.; Han, K.; Hanson, K.; Helbing, K.; Herquet, P.; Hickford, S.; Hill, G.C.; Hoffman, K.D.; Homeier, A.; Hoshina, K.; Hubert, D.; Huelsnitz, W.; Lafebre, S.J.

    2011-01-01

    Using the South Pole Acoustic Test Setup (SPATS) and a retrievable transmitter deployed in holes drilled for the IceCube experiment, we have measured the attenuation of acoustic signals by South Pole ice at depths between 190 m and 500 m. Three data sets, using different acoustic sources, have been

  17. Outdoor synthetic aperture acoustic ground target measurements

    Science.gov (United States)

    Bishop, Steven; Ngaya, Therese-Ann; Vignola, Joe; Judge, John; Marble, Jay; Gugino, Peter; Soumekh, Mehrdad; Rosen, Erik

    2010-04-01

    A novel outdoor synthetic aperture acoustic (SAA) system consists of a microphone and loudspeaker traveling along a 6.3-meter rail system. This is an extension from a prior indoor laboratory measurement system in which selected targets were insonified while suspended in air. Here, the loudspeaker and microphone are aimed perpendicular to their direction of travel along the rail. The area next to the rail is insonified and the microphone records the reflected acoustic signal, while the travel of the transceiver along the rail creates a synthetic aperture allowing imaging of the scene. Ground surfaces consisted of weathered asphalt and short grass. Several surface-laid objects were arranged on the ground for SAA imaging. These included rocks, concrete masonry blocks, grout covered foam blocks; foliage obscured objects and several spherical canonical targets such as a bowling ball, and plastic and metal spheres. The measured data are processed and ground targets are further analyzed for characteristics and features amenable for discrimination. This paper includes a description of the measurement system, target descriptions, synthetic aperture processing approach and preliminary findings with respect to ground surface and target characteristics.

  18. Acoustic CT system for temperature distribution measurement

    Institute of Scientific and Technical Information of China (English)

    Shinji Ohyama; Toyofumi Oga; Kazuo Oshima; Junya Takayama

    2008-01-01

    In this paper,a measurement method for crosssectional temperature distribution is addressed. A novel method based on an acoustic CT technique is proposed. Specifically,the temperature distributions are estimated using the time of flight data of several ultrasonic propagation paths. The times of the flight data contain both temperature and wind effect,and the method to select only temperature component is introduced. A filtered back projection method is applied to reconstruct the temperature distributions from the time of flight data. An experimental system was designed and fabricated to realize simultaneous temperature and wind velocity distribution measurements. Through this system,the effectiveness of the proposed measurement method is confirmed.

  19. Transforming Vectors Measured By Noncoaligned Instruments

    Science.gov (United States)

    Ritter, James R.; Dahlstrom, Eric L.

    1993-01-01

    Method for computing relationships between coordinate axes of two vector-measuring instruments not aligned with each other, one need only measure two nonparallel vectors u and v simultaneously in both coordinate systems. These measurements provide all data needed to compute transformation of any vector from one coordinate system to other. Particularly useful in computing alignments and transformations between accelerometers, gyroscopes, and instruments mounted on platforms subjected to vibrations, thermal strains, and other distortions causing alignments to vary unpredictably with time.

  20. Measuring the instrument function of radiometers

    Energy Technology Data Exchange (ETDEWEB)

    Winston, R. [Univ. of Chicago, IL (United States); Littlejohn, R.G. [Univ. of California, Berkeley, CA (United States)

    1997-12-31

    The instrument function is a function of position and angle, the knowledge of which allows one to compute the response of a radiometer to an incident wave field in any state of coherence. The instrument function of a given radiometer need not be calculated; instead, it may be measured by calibration with incident plane waves.

  1. Comparison of acoustic and strain gauge techniques for crack closure measurements

    Science.gov (United States)

    Buck, O.; Inman, R. V.; Frandsen, J. D.

    1976-01-01

    A quantitative study on the systems performances of the COD gauge and the acoustic transmission techniques to elastic deformation of part-through crack and compact tension specimens has been conducted. It is shown that the two instruments measure two completely different quantities: The COD gauge yields information on the length change of the specimen whereas the acoustic technique is sensitive directly to the amount of contract area between two surfaces, interfering with the acoustic signal. In another series of experiments, compression tests on parts with specifically prepared surfaces were performed so that the surface contact area could be correlated with the transmitted acoustic signal, as well as the acoustic with the COD gauge signal. A linear relation between contact area and COD gauge signal was obtained until full contact had been established.

  2. Measurement properties of patient-specific instruments measuring physical function.

    OpenAIRE

    Barten, J.A.; Pisters, M.F.; Huisman, P.A.; Takken, T; Veenhof, C.

    2012-01-01

    Objective: To identify patient-specific self-assessment instruments, which measure physical function in patients with musculoskeletal disorders and to evaluate the descriptive properties and the psychometric qualities of these instruments. Study Design and Setting: After a systematic search, included instruments were evaluated psychometrically by the checklist “quality criteria for measurement properties of health status instruments.” Results: Twenty-three studies were included, referring to ...

  3. Free Instrument for Movement Measure

    CERN Document Server

    Peña, Norberto; Corrêa, Lorena Peixoto Nogueira Rodriguez Martinez Salles; França, Lucas Gabriel Souza; Cunha, Marcelo do Vale; de Sousa, Marcos Cavalcanti; Vieira, João Paulo Bomfim Cruz; Miranda, José Garcia Vivas

    2013-01-01

    This paper presents the validation of a computational tool that serves to obtain continuous measurements of moving objects. The software uses techniques of computer vision, pattern recognition and optical flow, to enable tracking of objects in videos, generating data trajectory, velocity, acceleration and angular movement. The program was applied to track a ball around a simple pendulum. The methodology used to validate it, taking as a basis to compare the values measured by the program, as well as the theoretical values expected according to the model of a simple pendulum. The experiment is appropriate to the method because it was built within the limits of the linear harmonic oscillator and energy losses due to friction had been minimized, making it the most ideal possible. The results indicate that the tool is sensitive and accurate. Deviations of less than a millimeter to the extent of the trajectory, ensures the applicability of the software on physics, whether in research or in teaching topics.

  4. Measurement of acoustical characteristics of mosques in Saudi Arabia

    Science.gov (United States)

    Abdou, Adel A.

    2003-03-01

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

  5. Measuring Acoustic Nonlinearity by Collinear Mixing Waves

    Science.gov (United States)

    Liu, M.; Tang, G.; Jacobs, L. J.; Qu, J.

    2011-06-01

    It is well known that the acoustic nonlinearity parameter β is correlated to fatigue damage in metallic materials. Various methods have been developed to measure β. One of the most often used methods is the harmonic generation technique, in which β is obtained by measuring the magnitude of the second order harmonic waves. An inherent weakness of this method is the difficulty in distinguishing material nonlinearity from the nonlinearity of the measurement system. In this paper, we demonstrate the possibility of using collinear mixing waves to measure β. The wave mixing method is based on the interaction between two incident waves in a nonlinear medium. Under certain conditions, such interactions generate a third wave of different frequency. This generated third wave is also called resonant wave, because its amplitude is unbounded if the medium has no attenuation. Such resonant waves are less sensitive to the nonlinearity of the measurement system, and have the potential to identify the source location of the nonlinearity. In this work, we used a longitudinal wave and a shear wave as the incident waves. The resonant shear wave is measured experimentally on samples made of aluminum and steel, respectively. Numerical simulations of the tests were also performed using a finite difference method.

  6. Instrument development for safeguards measurements

    Energy Technology Data Exchange (ETDEWEB)

    Zebarth, M.; Davidson, D.; Koskelo, M.; Gardner, G. [Canberra Nuclear Products Group, Meriden, CT (United States)

    1996-12-31

    New safeguards requirements, such as those resulting from industrial reprocessing activities, makes the faster and more accurate determination of the uranium enrichment and/or the isotopic composition of plutonium essential in measuring the fissile mass. In response to these needs, Canberra has developed several improved safeguards systems in the last few years. In this paper, we will present an overview of our newest safeguards systems and the improvements they contain. The portable systems include the U-Pu InSpector, the IMCA and the JSR-14 systems. All combine automatic control of acquisition electronics and rapid analysis with an integrated software package for ease of use. The U-Pu InSpector incorporates the MGA code used by the IAEA and Euratom for plutonium analysis. The IMCA complies with IAEA PMCN and PMCG procedures for uranium analysis. With the JSR-14, we are currently developing the procedures to provide compliance with the IAEA neutron counting procedures. In addition to portable safeguards systems, Canberra has designed and installed many installed systems such as the WDAS and PSMC systems at PNC Tokai in Japan, and the large unattended neutron/gamma systems at Cogema La Hague and the Melox reprocessing facility in France. (author)

  7. Instrument development for safeguards measurements

    International Nuclear Information System (INIS)

    New safeguards requirements, such as those resulting from industrial reprocessing activities, makes the faster and more accurate determination of the uranium enrichment and/or the isotopic composition of plutonium essential in measuring the fissile mass. In response to these needs, Canberra has developed several improved safeguards systems in the last few years. In this paper, we will present an overview of our newest safeguards systems and the improvements they contain. The portable systems include the U-Pu InSpector, the IMCA and the JSR-14 systems. All combine automatic control of acquisition electronics and rapid analysis with an integrated software package for ease of use. The U-Pu InSpector incorporates the MGA code used by the IAEA and Euratom for plutonium analysis. The IMCA complies with IAEA PMCN and PMCG procedures for uranium analysis. With the JSR-14, we are currently developing the procedures to provide compliance with the IAEA neutron counting procedures. In addition to portable safeguards systems, Canberra has designed and installed many installed systems such as the WDAS and PSMC systems at PNC Tokai in Japan, and the large unattended neutron/gamma systems at Cogema La Hague and the Melox reprocessing facility in France. (author)

  8. Pulsed electro-acoustic (PEA) measurements of embedded charge distributions

    Science.gov (United States)

    Dennison, J. R.; Pearson, Lee H.

    2013-09-01

    Knowledge of the spatial distribution and evolution of embedded charge in thin dielectric materials has important applications in semiconductor, high-power electronic device, high-voltage DC power cable insulation, high-energy and plasma physics apparatus, and spacecraft industries. Knowing how, where, and how much charge accumulates and how it redistributes and dissipates can predict destructive charging effects. Pulsed Electro-acoustic (PEA) measurements— and two closely related methods, Pressure Wave Propagation (PWP) and Laser Intensity Modulation (LIMM)— nondestructively probe such internal charge distributions. We review the instrumentation, methods, theory and signal processing of simple PEA experiments, as well as the related PPW and LIMM methods. We emphasize system improvements required to achieve high spatial resolution for in vacuo measurements of thin dielectrics charged using electron beam injection.

  9. Solar oscillations instrumentation and measurement theory

    Science.gov (United States)

    Appourchaux, T.

    1988-01-01

    Solar-oscillation instruments are reviewed. Common characteristics include detecting solar radial velocities on Fraunhofer lines with a 2-point measuring technique, high spectral resolution and stability, etc. The choice of the spectral line for getting a high signal to solar noise ratio is addressed. Velocity imaging of solar oscillations modes is detailed, including spatial sampling and span, highest observable degree. Applications of these different analyses is applied to existing or future helioseismology instruments.

  10. Locating Tests and Measurement Instruments for Assessment

    Science.gov (United States)

    Mastel, Kristen; Morris-Knower, Jim; Marsalis, Scott

    2016-01-01

    Extension educators, staff, and specialists need to use surveys and other measurement instruments to assess their programming and conduct other research. Challenges in locating tests and measurement tools, however, include lack of time and lack of familiarity with techniques that can be used to find them. This article discusses library resources…

  11. Grafting Acoustic Instruments and Signal Processing: Creative Control and Augmented Expressivity

    DEFF Research Database (Denmark)

    Overholt, Daniel; Freed, Adrian

    that can be applied to bowed-string and other acoustic instruments, in order to provide immediate creative control over the possibilities offered by DSP. The study has focused on augmenting the expressivity of the violin towards finding novel timbral possibilities, rather than a goal of simulating prior...... acoustic violins with high fidelity. The opportunity to control a virtually malleable body while playing, i.e., a model that changes reverberant resonances in response to player input, results in interesting audio effects. Other common audio effects can also be employed and simultaneously controlled via...

  12. Instrument for measuring fuel cladding strain

    International Nuclear Information System (INIS)

    Development work to provide instrumentation for the continuous measurement of strain of material specimens such as nuclear fuel cladding has shown that a microwave sensor and associated instrumentation hold promise. The cylindrical sensor body enclosing the specimen results in a coaxial resonator absorbing microwave energy at frequencies dependent upon the diameter of the specimen. Diametral changes of a microinch can be resolved with use of the instrumentation. Very reasonable values of elastic strain were measured at 750F and 10000F for an internally pressurized 20 percent C.W. 316 stainless steel specimen simulating nuclear fuel cladding. The instrument also indicated the creep strain of the same specimen pressurized at 6500 psi and at a temperature of 10000F for a period of 700 hours. Although the indicated strain appears greater than actual, the sensor/specimen unit experienced considerable oxidation even though an inert gas purge persisted throughout the test duration. By monitoring at least two modes of resonance, the measured strain was shown to be nearly independent of sensor temperature. To prevent oxidation, a second test was performed in which the specimen/sensor units were contained in an evacuated enclosure. The strain of the two prepressurized specimens as indicated by the microwave instrumentation agreed very closely with pre- and post-test measurements obtained with use of a laser interferometer

  13. Wideband Instrument for Snow Measurements (WISM)

    Science.gov (United States)

    Miranda, Felix A.; Lambert, Kevin M.; Romanofsky, Robert R.; Durham, Tim; Speed, Kerry; Lange, Robert; Olsen, Art; Smith, Brett; Taylor, Robert; Schmidt, Mark; Racette, Paul; Bonds, Quenton; Brucker, Ludovic; Koenig, Lora; Marshall, Hans-Peter; Vanhille, Ken; Borissenko, Anatoly; Tsang, Leung; Tan, Shurun

    2016-01-01

    This presentation discusses current efforts to develop a Wideband Instrument for Snow Measurements (WISM). The objective of the effort are as follows: to advance the utility of a wideband active and passive instrument (8-40 gigahertz) to support the snow science community; improve snow measurements through advanced calibration and expanded frequency of active and passive sensors; demonstrate science utility through airborne retrievals of snow water equivalent (SWE); and advance the technology readiness of broadband current sheet array (CSA) antenna technology for spaceflight applications.

  14. Assessment of wind turbine load measurement instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Morfiadakis, E.; Papadopoulos, K. [CRES (Greece); Borg, N. van der [ECN, Petten (Netherlands); Petersen, S.M. [Risoe, Roskilde (Denmark); Seifert, H. [DEWI, Wilhelmshaven (Germany)

    1999-03-01

    In the framework of Sub-Task3 `Wind turbine load measurement instrumentation` of EU-project `European Wind Turbine Testing Procedure Development`, the load measurement techniques have been assessed by laboratory, full scale and numerical tests. The existing methods have been reviewed with emphasis on the strain gage application techniques on composite materials and recommendations are provided for the optimisation of load measurement techniques. (au) EU. 14 refs.

  15. Improvements in Elimination of Loudspeaker Distortion in Acoustic Measurements

    DEFF Research Database (Denmark)

    Agerkvist, Finn T.; Torras Rosell, Antoni; McWalter, Richard Ian

    2015-01-01

    This paper investigates the influence of nonlinear components that contaminate the linear response of acoustic transducers, and presents improved methods for eliminating the influence of nonlinearities in acoustic measurements. The method is evaluated with pure sinusoidal signals as well as swept...

  16. Compact Instruments Measure Helium-Leak Rates

    Science.gov (United States)

    Stout, Stephen; Immer, Christopher

    2003-01-01

    Compact, lightweight instruments have been developed for measuring small flows of helium and/or detecting helium leaks in solenoid valves when the valves are nominally closed. These instruments do not impede the flows when the valves are nominally open. They can be integrated into newly fabricated valves or retrofitted to previously fabricated valves. Each instrument includes an upstream and a downstream thermistor separated by a heater, plus associated analog and digital heater-control, signal- conditioning, and data-processing circuits. The thermistors and heater are off-the-shelf surface mount components mounted on a circuit board in the flow path. The operation of the instrument is based on a well-established thermal mass-flow-measurement technique: Convection by the flow that one seeks to measure gives rise to transfer of heat from the heater to the downstream thermistor. The temperature difference measured by the thermistors is directly related to the rate of flow. The calibration curve from temperature gradient to helium flow is closely approximated via fifth-order polynomial. A microprocessor that is part of the electronic circuitry implements the calibration curve to compute the flow rate from the thermistor readings.

  17. Towards an Enterprise Architecture Benefits Measurement Instrument

    NARCIS (Netherlands)

    Plessius, Henk; Steenbergen, van Marlies; Slot, Raymond

    2015-01-01

    Author supplied: Based on the Enterprise Architecture Value Framework (EAVF) - a generic framework to classify benefits of Enterprise Architecture (EA) - a measurement instrument for EA benefits has been developed and tested in a survey with 287 respondents. In this paper we present the results of

  18. Pulse energy measurement at the SXR instrument

    Energy Technology Data Exchange (ETDEWEB)

    Moeller, Stefan, E-mail: smoeller@slac.stanford.edu; Brown, Garth; Dakovski, Georgi; Hill, Bruce; Holmes, Michael; Loos, Jennifer; Maida, Ricardo; Paiser, Ernesto; Schlotter, William; Turner, Joshua J.; Wallace, Alex [Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Jastrow, Ulf; Kreis, Svea [Deutsches Elektronen-Synchrotron, DESY, Notkestrasse 85, D-22603 Hamburg (Germany); Sorokin, Andrey A. [Deutsches Elektronen-Synchrotron, DESY, Notkestrasse 85, D-22603 Hamburg (Germany); Ioffe Physico-Technical Institute, Polytekhnicheskaya 26, 194021 St Petersburg (Russian Federation); Tiedtke, Kai [Deutsches Elektronen-Synchrotron, DESY, Notkestrasse 85, D-22603 Hamburg (Germany)

    2015-04-14

    A gas monitor detector was implemented and characterized at the Soft X-ray Research instrument (SXR) to measure the average, absolute and pulse-resolved photon flux of the LCLS beam in the energy range between 280 and 2000 eV. A gas monitor detector was implemented and characterized at the Soft X-ray Research (SXR) instrument to measure the average, absolute and pulse-resolved photon flux of the LCLS beam in the energy range between 280 and 2000 eV. The detector is placed after the monochromator and addresses the need to provide reliable absolute pulse energy as well as pulse-resolved measurements for the various experiments at this instrument. This detector provides a reliable non-invasive measurement for determining flux levels on the samples in the downstream experimental chamber and for optimizing signal levels of secondary detectors and for the essential need of data normalization. The design, integration into the instrument and operation are described, and examples of its performance are given.

  19. Measurement properties of patient-specific instruments measuring physical function.

    NARCIS (Netherlands)

    Barten, J.A.; Pisters, M.F.; Huisman, P.A.; Takken, T.; Veenhof, C.

    2012-01-01

    Objective: To identify patient-specific self-assessment instruments, which measure physical function in patients with musculoskeletal disorders and to evaluate the descriptive properties and the psychometric qualities of these instruments. Study Design and Setting: After a systematic search, include

  20. Comparison of outburst danger criteria of coal seams for acoustic spectral and instrumental forecast methods

    Science.gov (United States)

    Shadrin, A. V.; Bireva, Yu A.

    2016-10-01

    Outburst danger criteria for the two methods of current coal seam outburst forecast are considered: instrumental - by the initial outgassing rate and chippings outlet during test boreholes drilling, and geo-physical - by relation of high frequency and low frequency components of noise caused by cutting tool of operating equipment probing the face area taking into consideration the outburst criteria correction based on methane concentration at the face area and the coal strength. The conclusion is made on “adjustment” possibility of acoustic spectral forecast method criterion amended by control of methane concentration at the coal face and the coal strength taken from the instrumental method forecast results.

  1. Spectral Test Instrument for Color Vision Measurement

    Institute of Scientific and Technical Information of China (English)

    Balázs Vince Nagy; Gy(o)rgy (A)brahám

    2005-01-01

    Common displays such as CRT or LCD screens have limited capabilities in displaying most color spectra correctly. The main disadvantage of these devices is that they work with three primaries and the colors displayed are the mixture of these three colours. Consequently these devices can be confusing in testing human color identification, because the spectral distribution of the colors displayed is the combined spectrum of the three primaries. We have developed a new instrument for spectrally correct color vision measurement. This instrument uses light emitting diodes (LEDs) and is capable of producing all spectra of perceivable colors, thus with appropriate test methods this instrument can be a reliable and useful tool in testing human color vision and in verifying color vision correction.

  2. Nuclear instrumentation for the industrial measuring systems

    International Nuclear Information System (INIS)

    This work deals with nuclear instrumentation and its application to industry, power plant fuel reprocessing plant and finally with homeland security. The first part concerns the reactor instrumentation, in-core and ex-core measurement system. Ionization Uranium fission chamber will be introduced with their acquisition system especially Campbell mode system. Some progress have been done on regarding sensors failure foresee. The second part of this work deals with reprocessing plant and associated instrumentation for nuclear waste management. Proportional counters techniques will be discussed, especially Helium-3 counter, and new development on electronic concept for reprocessing nuclear waste plant (one electronic for multipurpose acquisition system). For nuclear safety and security for human and homeland will be introduce. First we will explain a new particular approach on operational dosimetric measurement and secondly, we will show new kind of organic scintillator material and associated electronics. Signal treatment with real time treatment is embedded, in order to make neutron gamma discrimination possible even in solid organic scintillator. Finally, the conclusion will point out future, with most trends in research and development on nuclear instrumentation for next years. (author)

  3. Force measurement in a nanomachining instrument

    Science.gov (United States)

    Gao, Wei; Hocken, Robert J.; Patten, John A.; Lovingood, John

    2000-11-01

    Two miniature, high sensitivity force transducers were employed to measure the thrust force along the in-feed direction and the cutting force along the cross-feed direction in a nanomachining instrument. The instrument was developed for conducting fundamental experiments of nanocutting especially on brittle materials. The force transducers of piezoelectric quartz type can measure machining forces ranging from 0.2 mN to 10 N. The submillinewton resolution makes it possible to measure the machining forces in the cutting experiments with depths of cut as small as the nanometer level. The stiffness and resonant frequency of the force transducers are 400 mN/nm and 300 kHz, respectively, which meet the specification of the instrument. A force transducer assembly is designed to provide a mechanism to adjust the preload on the force transducer and to decouple the measurement of forces. The assembly consists of three dual-axis circular flexures and a subframe. The axial stiffness of the flexures is designed to be greater than 6×107 N/m and the lateral stiffness of the flexures is designed to be 1×106 N/m to provide proper decoupling of forces.

  4. Relationships between subjective and objective acoustical measures in churches

    OpenAIRE

    António P. Carvalho; António E. Morgado; Luís Henrique

    1997-01-01

    This study reports on subjective and objective acoustical field measurements made in a survey of 36 Catholic churches in Portugal built in the last 14 centuries. Monaural acoustical measurements (RT, EDT, C80, D50, TS and L) were taken at several source/receiver locations in each church and a group of college students was asked to judge the subjective quality of music. The listeners in each church evaluated live music performances at similar locations in each room. Evaluation sheets were used...

  5. A photophonic instrument concept to measure atmospheric aerosol absorption. M.S. Thesis

    Science.gov (United States)

    Engle, C. D.

    1982-01-01

    A laboratory model of an instrument to measure the absorption of atmospheric aerosols was designed, built, and tested. The design was based on the photophonic phenomenon discovered by Bell and an acoustic resonator developed by Helmholtz. Experiments were done to show ways the signal amplitude could be improved and the noise reduced and to confirm the instrument was sensitive enough to be practical. The research was undertaken to develop concepts which show promise of being improvements on the instruments that are presently used to measure the absorption of the Sun's radiation by the Earth's atmospheric aerosols.

  6. Measurement instruments and policies in Africa

    OpenAIRE

    Cabane, Lydie; Tantchou, Josiane

    2016-01-01

    Measurement instruments are increasingly important in the contemporary government of African. They are central to the rise of economic performance as a tool for reforming development aid and states. This has led to the emergence of new intervention methods (including experimentation and quantification) and generated political reconfigurations. These tools mobilise specific knowledge and experts, and put states in ambiguous positions. States must respect the technical infrastructure of interna...

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

    Science.gov (United States)

    Secchi, Simone; Lauria, Antonio; Cellai, Gianfranco

    2017-01-01

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

  8. Theory and signal processing of acoustic correlation techniques for current velocity measurement

    Institute of Scientific and Technical Information of China (English)

    ZHU Weiqing; FENG Lei; WANG Changhong; WANG Yuling; QIU Wei

    2008-01-01

    A theoretical model and signal processing of acoustic correlation measurements to estimate current velocity are discussed. The sonar space-time correlation function of vol-ume reverberations within Fraunhofer zone is derived. The function, which is in exponential forms, is the theoretical model of acoustic correlation measurements. The characteristics of the correlation values around the maximum of the amplitude of the correlation function, where most information about current velocity is contained, are primarily analyzed. Localized Least Mean Squares (LLMS) criterion is put forward for velocity estimation. Sequential Quadratic Programming (SQP) method is adopted as the optimization method. So the systematic sig-nal processing method of acoustic correlation techniques for current velocity measurement is established. A prototype acoustic correlation current profiler (ACCP) underwent several sea trials, the results show that theoretical model approximately coincides with experimental re-sults. Current profiles including the speed and direction from ACCP are compared with those from acoustic Doppler current profiler (ADCP). The current profiles by both instruments agree reasonably well. Also, the standard deviation of velocity measurement by ACCP is statistically calculated and it is a little larger than predicted value.

  9. Large Area Lunar Dust Flux Measurement Instrument

    Science.gov (United States)

    Corsaro, R.; Giovane, F.; Liou, Jer-Chyi; Burchell, M.; Stansbery, Eugene; Lagakos, N.

    2009-01-01

    The instrument under development is designed to characterize the flux and size distribution of the lunar micrometeoroid and secondary ejecta environment. When deployed on the lunar surface, the data collected will benefit fundamental lunar science as well as enabling more reliable impact risk assessments for human lunar exploration activities. To perform this task, the instrument requirements are demanding. It must have as large a surface area as possible to sample the very sparse population of the larger potentially damage-inducing micrometeorites. It must also have very high sensitivity to enable it to measure the flux of small (instrument designed to meet these requirements is called FOMIS. It is a large-area thin film under tension (i.e. a drum) with multiple fiber optic displacement (FOD) sensors to monitor displacements of the film. This sensor was chosen since it can measure displacements over a wide dynamic range: 1 cm to sub-Angstrom. A prototype system was successfully demonstrated using the hypervelocity impact test facility at the University of Kent (Canterbury, UK). Based on these results, the prototype system can detect hypervelocity (approx.5 km/s) impacts by particles as small as 2 microns diameter. Additional tests using slow speeds find that it can detect secondary ejecta particles (which do not penetrate the film) with momentums as small as 15 pico-gram 100m/s, or nominally 5 microns diameter at 100 m/s.

  10. Taking advantage of acoustic inhomogeneities in photoacoustic measurements

    Science.gov (United States)

    Da Silva, Anabela; Handschin, Charles; Riedinger, Christophe; Piasecki, Julien; Mensah, Serge; Litman, Amélie; Akhouayri, Hassan

    2016-03-01

    Photoacoustic offers promising perspectives in probing and imaging subsurface optically absorbing structures in biological tissues. The optical uence absorbed is partly dissipated into heat accompanied with microdilatations that generate acoustic pressure waves, the intensity which is related to the amount of fluuence absorbed. Hence the photoacoustic signal measured offers access, at least potentially, to a local monitoring of the absorption coefficient, in 3D if tomographic measurements are considered. However, due to both the diffusing and absorbing nature of the surrounding tissues, the major part of the uence is deposited locally at the periphery of the tissue, generating an intense acoustic pressure wave that may hide relevant photoacoustic signals. Experimental strategies have been developed in order to measure exclusively the photoacoustic waves generated by the structure of interest (orthogonal illumination and detection). Temporal or more sophisticated filters (wavelets) can also be applied. However, the measurement of this primary acoustic wave carries a lot of information about the acoustically inhomogeneous nature of the medium. We propose a protocol that includes the processing of this primary intense acoustic wave, leading to the quantification of the surrounding medium sound speed, and, if appropriate to an acoustical parametric image of the heterogeneities. This information is then included as prior knowledge in the photoacoustic reconstruction scheme to improve the localization and quantification.

  11. Signal processing and field measurements for underwater acoustic communications

    OpenAIRE

    Zhang, Guosong

    2013-01-01

    The present dissertation presents new developments in the signal processing of receiver structures for high-rate underwater acoustic communications, and describes the field measurements that test the structures in real oceanic environments. The signalling methods of spectrally efficient spread spectrum are also investigated to achieve long range underwater acoustic communications. The digital signal processing is of significance in recovering distorted information, and compensating waveform d...

  12. Acoustic levitator for containerless measurements on low temperature liquids

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-01-01

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

  13. Acoustical Measurement and Biot Model for Coral Reef Detection and Quantification

    Directory of Open Access Journals (Sweden)

    Henry M. Manik

    2016-01-01

    Full Text Available Coral reefs are coastal resources and very useful for marine ecosystems. Nowadays, the existence of coral reefs is seriously threatened due to the activities of blast fishing, coral mining, marine sedimentation, pollution, and global climate change. To determine the existence of coral reefs, it is necessary to study them comprehensively. One method to study a coral reef by using a propagation of sound waves is proposed. In this research, the measurement of reflection coefficient, transmission coefficient, acoustic backscattering, hardness, and roughness of coral reefs has been conducted using acoustic instruments and numerical modeling using Biot theory. The results showed that the quantification of the acoustic backscatter can classify the type of coral reef.

  14. Field-Deployable Acoustic Digital Systems for Noise Measurement

    Science.gov (United States)

    Shams, Qamar A.; Wright, Kenneth D.; Lunsford, Charles B.; Smith, Charlie D.

    2000-01-01

    Langley Research Center (LaRC) has for years been a leader in field acoustic array measurement technique. Two field-deployable digital measurement systems have been developed to support acoustic research programs at LaRC. For several years, LaRC has used the Digital Acoustic Measurement System (DAMS) for measuring the acoustic noise levels from rotorcraft and tiltrotor aircraft. Recently, a second system called Remote Acquisition and Storage System (RASS) was developed and deployed for the first time in the field along with DAMS system for the Community Noise Flight Test using the NASA LaRC-757 aircraft during April, 2000. The test was performed at Airborne Airport in Wilmington, OH to validate predicted noise reduction benefits from alternative operational procedures. The test matrix was composed of various combinations of altitude, cutback power, and aircraft weight. The DAMS digitizes the acoustic inputs at the microphone site and can be located up to 2000 feet from the van which houses the acquisition, storage and analysis equipment. Digitized data from up to 10 microphones is recorded on a Jaz disk and is analyzed post-test by microcomputer system. The RASS digitizes and stores acoustic inputs at the microphone site that can be located up to three miles from the base station and can compose a 3 mile by 3 mile array of microphones. 16-bit digitized data from the microphones is stored on removable Jaz disk and is transferred through a high speed array to a very large high speed permanent storage device. Up to 30 microphones can be utilized in the array. System control and monitoring is accomplished via Radio Frequency (RF) link. This paper will present a detailed description of both systems, along with acoustic data analysis from both systems.

  15. 21 CFR 886.1460 - Stereopsis measuring instrument.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Stereopsis measuring instrument. 886.1460 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1460 Stereopsis measuring instrument. (a) Identification. A stereopsis measuring instrument is a device intended to measure...

  16. 21 CFR 886.1425 - Lens measuring instrument.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Lens measuring instrument. 886.1425 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Diagnostic Devices § 886.1425 Lens measuring instrument. (a) Identification. A lens measuring instrument is an AC-powered device intended to measure the power of...

  17. Acoustic measurements of models of military style supersonic nozzle jets

    NARCIS (Netherlands)

    Kuo, C.W.; Veltin, J.; McLaughlin, D.K.

    2014-01-01

    Modern military aircraft jet engines are designed with variable-geometry nozzles to provide optimal thrust in different operating conditions, depending on the flight envelope. However, acoustic measurements for such nozzles are scarce, due to the cost involved in making full-scale measurements and t

  18. Development of acoustic flow instruments for solid/gas pipe flows

    International Nuclear Information System (INIS)

    Two nonintrusive acoustic flow sensing techniques are reported. One technique, passive in nature, simply measures the bandpassed acoustic noise level produced by particle/particle and particle/wall collisions. The noise levels, given in true RMS voltages or in autocorrelations, show a linear relationship to particle velocity but increase with solid concentration. Therefore, the passive technique requires calibration and a separate measure of solid concentration before it can be used to monitor the particle velocity. The second technique is based on the active cross-correlation principle. It measures particle velocity directly by correlating flow-related signatures at two sensing stations. The velocity data obtained by this technique are compared with measurements by a radioactive-particle time-of-flight (TOF) method. A multiplier of 1.53 is required to bring the acoustic data into agreement with the radioactive TOF result. The difference may originate from the difference in flow fields where particles are detected. The radioactive method senses particles mainly in the turbulent region and essentially measures average particle velocity across the pipe, while the acoustic technique detects particles near the pipe wall, and so measures the particle velocity in the viscous sublayer. Both techniques were tested in flows of limestone and air and 1-mm glass beads and air at the Argonne National Laboratory Solid/Gas Test Facility (SGFTF). The test matrix covered solid velocities of 20 to 30 m/s in a 2-in. pipe and solid-to-gas loading ratios of 6 to 22. 37 refs., 19 figs., 4 tabs

  19. Measurement of thin films using very long acoustic wavelengths

    CERN Document Server

    Clement, G T; Adachi, H; Kamakura, T

    2013-01-01

    A procedure for measuring material thickness by means of necessarily-long acoustic wavelengths is examined. The approach utilizes a temporal phase lag caused by the impulse time of wave momentum transferred through a thin layer that is much denser than its surrounding medium. In air, it is predicted that solid or liquid layers below approximately 1/2000 of the acoustic wavelength will exhibit a phase shift with an arctangent functional dependence on thickness and layer density. The effect is verified for thin films on the scale of 10 microns using audible frequency sound (7 kHz). Soap films as thin as 100 nm are then measured using 40 kHz air ultrasound. The method's potential for imaging applications is demonstrated by combining the approach with near-field holography, resulting in reconstructions with sub-wavelength resolution in both the depth and lateral directions. Potential implications at very high and very low acoustic frequencies are discussed.

  20. Acoustic Liner Drag: Measurements on Novel Facesheet Perforate Geometries

    Science.gov (United States)

    Howerton, Brian M.; Jones, Michael G.

    2016-01-01

    Interest in characterization of the aerodynamic drag of acoustic liners has increased in the past several years. This paper details experiments in the NASA Langley Grazing Flow Impedance Tube to quantify the relative drag of several perforate-over-honeycomb liner configurations at flow speeds of centerline flow Mach number equals 0.3 and 0.5. Various perforate geometries and orientations are investigated to determine their resistance factors using a static pressure drop approach. Comparison of these resistance factors gives a relative measurement of liner drag. For these same flow conditions, acoustic measurements are performed with tonal excitation from 400 to 3000 hertz at source sound pressure levels of 140 and 150 decibels. Educed impedance and attenuation spectra are used to determine the impact of variations in perforate geometry on acoustic performance.

  1. Bimodal schwa: Evidence from acoustic measurements

    Science.gov (United States)

    Yamane-Tanaka, Noriko; Gick, Bryan; Bird, Sonya

    2001-05-01

    The question of whether schwa is targeted or targetless has been the subject of much debate (Browman et al., 1992; Browman and Goldstein, 1995; Gick, 1999, 2002). Gick (2002) found that there is a pharyngeal constriction during schwa relative to rest position, and concluded that schwa is not targetless. This experiment further showed a ``bimodal'' pattern in schwa in a nonrhotic speaker, indicating that the subject has distinct schwas in lexical words and function words. The present study examines the existence of the ``bimodal'' pattern in schwas in nonrhotic dialects through an acoustic experiment. It is predicted that there is a significant difference in formant values between lexical schwas and function schwas. Results to date indicate a significant difference in them between schwas in lexical versus function words, both between historical schwas and those derived from final /r/ reduction. Data from several additional nonrhotic subjects will be presented. Implications for intrusive r as well as for the phonological treatment of function words will be discussed. [Work funded by NSERC and SSHRC.

  2. Velocity and rotation measurements in acoustically levitated droplets

    Science.gov (United States)

    Saha, Abhishek; Basu, Saptarshi; Kumar, Ranganathan

    2012-10-01

    The velocity scale inside an acoustically levitated droplet depends on the levitator and liquid properties. Using Particle Imaging Velocimetry (PIV), detailed velocity measurements have been made in a levitated droplet of different diameters and viscosity. The maximum velocity and rotation are normalized using frequency and amplitude of acoustic levitator, and droplet viscosity. The non-dimensional data are fitted for micrometer- and millimeter-sized droplets levitated in different levitators for different viscosity fluids. It is also shown that the rotational speed of nanosilica droplets at an advanced stage of vaporization compares well with that predicted by exponentially fitted parameters.

  3. Measuring System for Interference Optical Fiber Acoustic Emission①

    Institute of Scientific and Technical Information of China (English)

    LUQizhu; ZHENGShengxuan

    1997-01-01

    A type of interference optical fiber acoustic emission sensor is described.With 10-10 m level resolution,megahertz-level frequency and response time less than 1 μs,this sensor possesses prominent measuring stability and can be used in state supervision and trouble diagnosis.

  4. Eliminating transducer distortion in acoustic measurements

    DEFF Research Database (Denmark)

    Agerkvist, Finn T.; Torras Rosell, Antoni; McWalter, Richard Ian

    2014-01-01

    to perform well even in noisy conditions. The limitations of the Total Harmonic Distortion, THD, measure is discussed and a new distortion measure, Total Distortion Ratio, TDR, which more accurately describes the amount of nonlinear power in the measured signal, is proposed....

  5. Acoustic measuring of partial discharge in power transformers

    International Nuclear Information System (INIS)

    Power transformers' reliability can be seriously affected by partial discharges. For this reason, it is necessary to implement technical methods to identify endangered equipment before catastrophic failures occur. A well-known method that can be applied either in the laboratory or in the field is the detection and localization of partial discharges, by means of the analysis of the acoustic signals they produced. An innovative partial discharge detector was developed based on the analysis of an acoustic or electrical PD signal envelope. This paper describes the architecture of the developed acoustic detector, which is composed of a set of ultrasonic sensors, signal conditioning and control modules, a graphical interface and the required software for the location of the affected area within the transformer. The conditioning and control modules perform analog to digital conversion, arrival time measurement, communication and control operations. Finally, some power transformer diagnostic testing is presented and discussed

  6. Broadband acoustic scattering measurements of underwater unexploded ordnance (UXO).

    Science.gov (United States)

    Bucaro, J A; Houston, B H; Saniga, M; Dragonette, L R; Yoder, T; Dey, S; Kraus, L; Carin, L

    2008-02-01

    In order to evaluate the potential for detection and identification of underwater unexploded ordnance (UXO) by exploiting their structural acoustic response, we carried out broadband monostatic scattering measurements over a full 360 degrees on UXO's (two mortar rounds, an artillery shell, and a rocket warhead) and false targets (a cinder block and a large rock). The measurement band, 1-140 kHz, includes a low frequency structural acoustics region in which the wavelengths are comparable to or larger than the target characteristic dimensions. In general, there are aspects that provide relatively high target strength levels ( approximately -10 to -15 dB), and from our experience the targets should be detectable in this structural acoustics band in most acoustic environments. The rigid body scattering was also calculated for one UXO in order to highlight the measured scattering features involving elastic responses. The broadband scattering data should be able to support feature-based separation of UXO versus false targets and identification of various classes of UXO as well.

  7. Calibration of solar radiation measuring instruments. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Bahm, R J; Nakos, J C

    1979-11-01

    A review of solar radiation measurement of instruments and some types of errors is given; and procedures for calibrating solar radiation measuring instruments are detailed. An appendix contains a description of various agencies who perform calibration of solar instruments and a description of the methods they used at the time this report was prepared. (WHK)

  8. Development of the emergency physician job satisfaction measurement instrument.

    Science.gov (United States)

    Lloyd, S; Streiner, D; Hahn, E; Shannon, S

    1994-01-01

    The objective of this study was to develop a valid and reliable instrument to measure the job satisfaction of physicians practicing emergency medicine. A prospective survey involving four separate stages (an item evaluation and reduction stage, a factor analysis stage, a construct validity stage, and a reliability stage) was distributed in Canada to full-time emergency physicians. Three separate survey instruments were administered (an initial draft instrument with 228 items, a pilot instrument with 142 items, and the final instrument with 79 items). Construct validity of the final instrument was tested by evaluating the correlation between physician scores on the instrument, and scores on two instruments measuring the same construct, and three measuring different but related constructs. A draft instrument with 228 items and six hypothetical domains was tested on 61 physicians. Evaluation for frequency endorsement, redundancy, and homogeneity reduced the item pool to 157. The remaining 157 items were used as a pilot instrument and tested on 223 physicians. Factor analysis eliminated 66 items from the pilot instrument, creating a final instrument with 79 items, 11 factors, and six domains. Cronbach's coefficient alpha for the final instrument domains is 0.81, and all domain-total correlations are greater than 0.4. All correlations between the final instrument and the construct validity instruments were statistically significant (P job satisfaction, which is both internally consistent and stable.

  9. Underwater Acoustic Measurements to Estimate Wind and Rainfall in the Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    Sara Pensieri

    2015-01-01

    Full Text Available Oceanic ambient noise measurements can be analyzed to obtain qualitative and quantitative information about wind and rainfall phenomena over the ocean filling the existing gap of reliable meteorological observations at sea. The Ligurian Sea Acoustic Experiment was designed to collect long-term synergistic observations from a passive acoustic recorder and surface sensors (i.e., buoy mounted rain gauge and anemometer and weather radar to support error analysis of rainfall rate and wind speed quantification techniques developed in past studies. The study period included combination of high and low wind and rainfall episodes and two storm events that caused two floods in the vicinity of La Spezia and in the city of Genoa in 2011. The availability of high resolution in situ meteorological data allows improving data processing technique to detect and especially to provide effective estimates of wind and rainfall at sea. Results show a very good correspondence between estimates provided by passive acoustic recorder algorithm and in situ observations for both rainfall and wind phenomena and demonstrate the potential of using measurements provided by passive acoustic instruments in open sea for early warning of approaching coastal storms, which for the Mediterranean coastal areas constitutes one of the main causes of recurrent floods.

  10. Measurement of acoustic attenuation in workrooms

    DEFF Research Database (Denmark)

    Rindel, Jens Holger

    1997-01-01

    Experimental work has been done in nine halls with volumes ranging from 693 to 123.978 cubic metres. The equivalent absorption area has been determined from absorption coefficients of the surfaces, calculated from reverberation time measurements and estimated from sound pressure level measurements...... in the stationary sound field produced by an omnidirectional sound source in the room. The project has shown that there is a need for a new alternative measuring method - the results based on the classical reverberation time measurements do not agree sufficiently well with the actual equivalent absorption areas...... in the rooms. But it has not been possible within the project to establish and verify an alternative method based on a simple measurement in the stationary sound field....

  11. Modeling the receptivity of an air jet to transverse acoustic disturbance with application to musical instruments.

    Science.gov (United States)

    Blanc, F; François, V; Fabre, B; de la Cuadra, P; Lagrée, P-Y

    2014-06-01

    A simple analytical model for the interaction between a plane jet issued from a flue and a transverse acoustic disturbance is developed in this paper. The model is inspired by direct flow simulation results confronted to experimental data. The interaction is expected to take place in the vicinity of the separation points of the jet. The influence of the detailed geometry of the channel end on the jet receptivity is discussed, and more specifically the chamfer geometries found in flute-like musical instruments. The simplified model explains quite well the difference between the jet response of a flue with square edges compared to a chamfered flue exit. The effect of rounded, lip-like flue exit is not well captured by the model.

  12. Volumetric measurements of a spatially growing dust acoustic wave

    Science.gov (United States)

    Williams, Jeremiah D.

    2012-11-01

    In this study, tomographic particle image velocimetry (tomo-PIV) techniques are used to make volumetric measurements of the dust acoustic wave (DAW) in a weakly coupled dusty plasma system in an argon, dc glow discharge plasma. These tomo-PIV measurements provide the first instantaneous volumetric measurement of a naturally occurring propagating DAW. These measurements reveal over the measured volume that the measured wave mode propagates in all three spatial dimensional and exhibits the same spatial growth rate and wavelength in each spatial direction.

  13. Volumetric measurements of a spatially growing dust acoustic wave

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Jeremiah D. [Physics Department, Wittenberg University, Springfield, Ohio 45504 (United States)

    2012-11-15

    In this study, tomographic particle image velocimetry (tomo-PIV) techniques are used to make volumetric measurements of the dust acoustic wave (DAW) in a weakly coupled dusty plasma system in an argon, dc glow discharge plasma. These tomo-PIV measurements provide the first instantaneous volumetric measurement of a naturally occurring propagating DAW. These measurements reveal over the measured volume that the measured wave mode propagates in all three spatial dimensional and exhibits the same spatial growth rate and wavelength in each spatial direction.

  14. Energy Based Acoustic Measurement Senors Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This research focuses on fully developing energy density sensors that will yield a significant benefit both for measurements of interest to NASA, as well as for...

  15. Instrument Relevance in Multivariate Linear Models: A Simple Measure

    OpenAIRE

    John Shea

    1996-01-01

    The correlation between instruments and explanatory variables is a key determinant of the performance of the instrumental variables estimator. The R-squared from regressing the explanatory variable on the instrument vector is a useful measure of relevance in univariate models, but can be misleading when there are multiple endogenous variables. This paper proposes a computationally simple partial R- squared measure of instrument relevance for multivariate models.

  16. Acoustic Emissions to Measure Drought-Induced Cavitation in Plants

    Directory of Open Access Journals (Sweden)

    Linus De Roo

    2016-03-01

    Full Text Available Acoustic emissions are frequently used in material sciences and engineering applications for structural health monitoring. It is known that plants also emit acoustic emissions, and their application in plant sciences is rapidly increasing, especially to investigate drought-induced plant stress. Vulnerability to drought-induced cavitation is a key trait of plant water relations, and contains valuable information about how plants may cope with drought stress. There is, however, no consensus in literature about how this is best measured. Here, we discuss detection of acoustic emissions as a measure for drought-induced cavitation. Past research and the current state of the art are reviewed. We also discuss how the acoustic emission technique can help solve some of the main issues regarding quantification of the degree of cavitation, and how it can contribute to our knowledge about plant behavior during drought stress. So far, crossbreeding in the field of material sciences proved very successful, and we therefore recommend continuing in this direction in future research.

  17. A System for Acoustic Field Measurement Employing Cartesian Robot

    Directory of Open Access Journals (Sweden)

    Szczodrak Maciej

    2016-09-01

    Full Text Available A system setup for measurements of acoustic field, together with the results of 3D visualisations of acoustic energy flow are presented in the paper. Spatial sampling of the field is performed by a Cartesian robot. Automatization of the measurement process is achieved with the use of a specialized control system. The method is based on measuring the sound pressure (scalar and particle velocity(vector quantities. The aim of the system is to collect data with a high precision and repeatability. The system is employed for measurements of acoustic energy flow in the proximity of an artificial head in an anechoic chamber. In the measurement setup an algorithm for generation of the probe movement path is included. The algorithm finds the optimum path of the robot movement, taking into account a given 3D object shape present in the measurement space. The results are presented for two cases, first without any obstacle and the other - with an artificial head in the sound field.

  18. Acoustics and the Performance of Music Manual for Acousticians, Audio Engineers, Musicians, Architects and Musical Instrument Makers

    CERN Document Server

    Meyer, Jürgen

    2009-01-01

    Acoustics and the Performance of Music connects scientific understandings of acoustics with practical applications to musical performance. Of central importance are the tonal characteristics of musical instruments and the singing voice including detailed representations of directional characteristics. Furthermore, room acoustical concerns related to concert halls and opera houses are considered. Based on this, suggestions are made for musical performance. Included are seating arrangements within the orchestra and adaptations of performance techniques to the performance environment. In the presentation we dispense with complicated mathematical connections and deliberately aim for conceptual explanations accessible to musicians, particularly for conductors. The graphical representations of the directional dependence of sound radiation by musical instruments and the singing voice are unique. Since the first edition was published in 1978, this book has been completely revised and rewritten to include current rese...

  19. INTELLIGENT VIRTUAL CONTROL:MEASURING INSTRUMENT FROM WHOLE TO PART

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A new concept called intelligent virtual control (IVC), which can be driven by measuring functions, is put forward. This small "intelligent measurement instrument unit (IMIU)", carrying with functions of instrument, consists of different types of intelligent virtual instrument (IVI) through individual components together as building blocks and can be displayed directly on the computer screen. This is a new concept of measuring instrument, and also an important breakthrough after virtual instrument (VI). Virtual control makes instrument resources obtain further exploitation. It brings about a fundamental change to the design and manufacturing mode. The instrument therefore, can not only be produced directly inside a PC, but the product is involved in the "green product" system. So far, all the present digital instruments will grow to be replaced by intelligent control with green characteristics.

  20. Optoelectronic hybrid fiber laser sensor for simultaneous acoustic and magnetic measurement.

    Science.gov (United States)

    Wang, Zhaogang; Zhang, Wentao; Huang, Wenzhu; Feng, Shengwen; Li, Fang

    2015-09-21

    An optoelectronic hybrid fiber optic acoustic and magnetic sensor (FOAMS) based on fiber laser sensing is proposed, which can measure acoustic and magnetic field simultaneously. A static magnetic field signal can be carried by an AC Lorentz force, and demodulated in frequency domain together with acoustic signals. Some experiments of acoustic pressure sensitivity, magnetic field sensitivity, and simultaneous acoustic and magnetic measurement on a fabricated FOAMS were carried out. The acoustic pressure sensitivity was about -164.7 dB (0 dB re 1 pm/μPa) and the magnetic field sensitivity was 0.6 dB (0 dB re 1 pm/ (T•A)). The experiment of simultaneous acoustic and magnetic measurement shows that the detections of acoustic and magnetic field have little effect on each other in dynamic range and simultaneously measuring acoustic and magnetic field is feasible. PMID:26406643

  1. Low-background β count and α spectrum measuring instrument

    International Nuclear Information System (INIS)

    An low-background β count and α spectrum measuring instrument which is used to ocean radiation investigation is introduced in this paper. It capable of simultaneously measure low activity β count and analyse α spectrum. Overcome by using two sets of Instrument were measured β count and α spectrum of trouble, and reduce the measurement error. (authors)

  2. EFFECT OF SOAKING PROCESS IN WATER ON THE ACOUSTICAL QUALITY OF WOOD FOR TRADITIONAL MUSICAL INSTRUMENTS

    Directory of Open Access Journals (Sweden)

    Mehran Roohnia

    2011-04-01

    Full Text Available The damping coefficient of the first mode in the longitudinal vibration of mulberry and walnut woods was characterized to find justifications for the water soaking of woods in traditional musical instrument industries in Iran. Visually clear and sound beams were prepared from Morus alba and Juglans regia, and the damping coefficient in the temporal field was evaluated before and after three continuous cycles of soaking of specimens in distilled water (24 hours, pH 7, and temperature 50 oC. Experiments were conducted with free longitudinal vibration using the free-free bar method in 360×20×20 (L×R×T dimensions. Soaking cycles homogenized and decreased the damping coefficient in both species. On the basis of such results, the suitability of water soaked specimens is discussed in traditional musical instrument industries in Iran, taking into the account the longitudinal sound velocity, modulus of elasticity, and density affecting the acoustic limits. These two series of testing specimens were suitable in resonators and xylophone bars for backs, sides, and ribs and not for top plates, unless as the outstanding piece, since they marginally meet the density, sound velocity and damping coefficient limits qualified for those applications.

  3. Experimental measurement of acoustic plasmons in polycrystalline palladium

    Science.gov (United States)

    Garrity, Patrick L.

    2013-03-01

    An experimental study of collective oscillations in Pd covering the region of very low energy and momentum transfers is reported. Through Dynamic Electron Scattering spectroscopy, structure factor spectra were measured from 80 K to 298 K on a bulk polycrystalline Pd sample. Here we report the first experimental evidence of damped acoustic plasmons and their evolution to the single-particle excitation continuum. The acoustic plasmons follow a linear dispersion and are experimentally shown to be a separate and distinct resonance mode from acoustic surface plasmons. Calculations of the dielectric function employed a model that incorporates complete mixing of two conduction bands with contributions from both interband and intraband transitions. The model was used in computational studies that focused on specific experimental results to aid the characterization and understanding of the plasmon behavior. We found that the Pd acoustic plasmon energy matched the longitudinal phonon anomaly that has sparked numerous theoretical reports on the possible energetic coupling of these modes. Further experimental evidence of plasmon and phonon dynamical processes are found in the linewidth analysis of the data. The primary decay mechanism of the plasmons is interpreted to be strong phonon-assisted interband transitions. Further spectral features and the plasmon velocity are also reported.

  4. Acoustic transmission in SGUs: Plant and laboratory measurements

    International Nuclear Information System (INIS)

    As part of the UK development work an experimental programme is in progress to measure the acoustic transmission through an actual reactor SGU and also through a model tube bundle in the laboratory. This paper gives an outline of the experimental arrangements and examples of the preliminary results. The data from the laboratory measurements in particular is being used for comparison with theoretical studies carried out at the University of Keele which are reported in a separate paper to this Specialist's Meeting. The plant measurements are being carried out on a Superheater unit of the Prototype Fast Reactor (PFR) at Dounreay. These measurements are primarily aimed at providing information for a loose parts condition monitoring system which is operated on the PFR SGU, but results obtained will make a significant contribution to the acoustic leak detection programme. The Superheater used for the experiment has six blank steam tubes for experimental purposes. An impacting device has been inserted into one of the blank tubes and acoustic signals recorded on waveguides which are attached to the SGU shell. Recordings were made during a reactor shutdown with static sodium in the superheater and with the impacting device at five axial positions in both the inner and outer legs of the 'U' tube. Results are given for signal attenuation and location of the acoustic noise source. The laboratory measurements are being made using a 721-tube model tube bundle in a water tank. The tube bundle which is approximately 0.75m diameter x 3 metres long is not modelled to a specific design but is of realistic size and construction. A piezo-electric acoustic source is mounted centrally in the tube bundle and the transmitted signal is received by underwater microphones on the periphery of the bundle. Results from the first experiments with water filled tubes are given covering a frequency range of 6KHz to 80KHz. The preliminary results of the experimental programme are encouraging and

  5. The information content of anisotropic Baryon Acoustic Oscillation scale measurements

    OpenAIRE

    Ross, Ashley J.; Percival, Will J.; Manera, Marc

    2015-01-01

    Anisotropic measurements of the Baryon Acoustic Oscillation (BAO) feature within a galaxy survey enable joint inference about the Hubble parameter $H(z)$ and angular diameter distance $D_A(z)$. These measurements are typically obtained from moments of the measured 2-point clustering statistics, with respect to the cosine of the angle to the line of sight $\\mu$. The position of the BAO features in each moment depends on a combination of $D_A(z)$ and $H(z)$, and measuring the positions in two o...

  6. Quality of life: consideration about indicators and measurement instruments

    OpenAIRE

    Alves, Everton Fernando

    2011-01-01

    International audience The measuring instruments are developed for many different purposes and directions, being held by generic scales of health status and specific scales to a given situation. This study aimed to discuss the important issues that permeate the use of measuring instruments and provide a systematic way of indicators and measuring instruments used in QL and validated in Brazil. It was conducted a study of narrative review of available knowledge in the literature, consultatio...

  7. Design and implementation of an efficient acoustically levitated drop reactor for in stillo measurements.

    Science.gov (United States)

    Field, Christopher R; Scheeline, Alexander

    2007-12-01

    We present the details necessary for building an efficient acoustic drop levitator with reduced electrical power consumption and greater drop stability compared to previous designs. The system is optimized so that the levitated drop may be used as a chemical reactor. By introducing a temperature, pressure, and relative humidity sensor for feedback control of a linear actuator for adjusting resonator length, we have built a completely automated system capable of continuous levitation for extended periods of time. The result is a system capable of portable operation and interfacing with a variety of detection instrumentation for in stillo (in drop) measurements. PMID:18163744

  8. Chemical Microsensor Instrument for UAV Airborne Atmospheric Measurements Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Makel Engineering, Inc. (MEI) proposes to develop a miniaturized Airborne Chemical Microsensor Instrument (ACMI) suitable for real-time, airborne measurements of...

  9. Compact Instrument for Measurement of Atmospheric Carbon Monoxide Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Southwest Sciences proposed the development of a rugged, compact, and automated instrument for the high sensitivity measurement of tropospheric carbon monoxide...

  10. Compact Instrument for Measurement of Atmospheric Carbon Monoxide Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Southwest Sciences proposes to continue the development of a rugged, compact, and automated instrument for the high sensitivity measurement of tropospheric carbon...

  11. Standardization of near infrared spectra measured on multi-instrument.

    Science.gov (United States)

    Liu, Yan; Cai, Wensheng; Shao, Xueguang

    2014-07-11

    Calibration model transfer is essential for practical applications of near infrared (NIR) spectroscopy because the measurements of the spectra may be performed on different instruments and the difference between the instruments must be corrected. An approach for calibration transfer based on alternating trilinear decomposition (ATLD) algorithm is proposed in this work. From the three-way spectral matrix measured on different instruments, the relative intensity of concentration, spectrum and instrument is obtained using trilinear decomposition. Because the relative intensity of instrument is a reflection of the spectral difference between instruments, the spectra measured on different instruments can be standardized by a correction of the coefficients in the relative intensity. Two NIR datasets of corn and tobacco leaf samples measured with three instruments are used to test the performance of the method. The results show that, for both the datasets, the spectra measured on one instrument can be correctly predicted using the partial least squares (PLS) models built with the spectra measured on the other instruments.

  12. Acoustic impedances of ear canals measured by impedance tube

    DEFF Research Database (Denmark)

    Ciric, Dejan; Hammershøi, Dorte

    2007-01-01

    During hearing sensitivity tests, the sound field is commonly generated by an earphone placed on a subject ear. One of the factors that can affect the sound transmission in the ear is the acoustic impedance of the ear canal. Its importance is related to the contribution of other elements involved...... locations in an impedance tube. The end of the tube representing the measurement plane is placed at the ear canal entrance. Thus, the impedance seen from the entrance inward is measured on 25 subjects. Most subjects participated in the previous measurement of the ratio between the pressures at the open...

  13. Flow velocity measurement with the nonlinear acoustic wave scattering

    Science.gov (United States)

    Didenkulov, Igor; Pronchatov-Rubtsov, Nikolay

    2015-10-01

    A problem of noninvasive measurement of liquid flow velocity arises in many practical applications. To this end the most often approach is the use of the linear Doppler technique. The Doppler frequency shift of signal scattered from the inhomogeneities distributed in a liquid relatively to the emitted frequency is proportional to the sound frequency and velocities of inhomogeneities. In the case of very slow flow one needs to use very high frequency sound. This approach fails in media with strong sound attenuation because acoustic wave attenuation increases with frequency and there is limit in increasing sound intensity, i.e. the cavitation threshold. Another approach which is considered in this paper is based on the method using the difference frequency Doppler Effect for flows with bubbles. This method is based on simultaneous action of two high-frequency primary acoustic waves with closed frequencies on bubbles and registration of the scattered by bubbles acoustic field at the difference frequency. The use of this method is interesting since the scattered difference frequency wave has much lower attenuation in a liquid. The theoretical consideration of the method is given in the paper. The experimental examples confirming the theoretical equations, as well as the ability of the method to be applied in medical diagnostics and in technical applications on measurement of flow velocities in liquids with strong sound attenuation is described. It is shown that the Doppler spectrum form depends on bubble concentration velocity distribution in the primary acoustic beams crossing zone that allows one to measure the flow velocity distribution.

  14. Flow velocity measurement with the nonlinear acoustic wave scattering

    Energy Technology Data Exchange (ETDEWEB)

    Didenkulov, Igor, E-mail: din@appl.sci-nnov.ru [Institute of Applied Physics, 46 Ulyanov str., Nizhny Novgorod, 603950 (Russian Federation); Lobachevsky State University of Nizhny Novgorod, 23 Gagarin ave., Nizhny Novgorod, 603950 (Russian Federation); Pronchatov-Rubtsov, Nikolay, E-mail: nikvas@rf.unn.ru [Lobachevsky State University of Nizhny Novgorod, 23 Gagarin ave., Nizhny Novgorod, 603950 (Russian Federation)

    2015-10-28

    A problem of noninvasive measurement of liquid flow velocity arises in many practical applications. To this end the most often approach is the use of the linear Doppler technique. The Doppler frequency shift of signal scattered from the inhomogeneities distributed in a liquid relatively to the emitted frequency is proportional to the sound frequency and velocities of inhomogeneities. In the case of very slow flow one needs to use very high frequency sound. This approach fails in media with strong sound attenuation because acoustic wave attenuation increases with frequency and there is limit in increasing sound intensity, i.e. the cavitation threshold. Another approach which is considered in this paper is based on the method using the difference frequency Doppler Effect for flows with bubbles. This method is based on simultaneous action of two high-frequency primary acoustic waves with closed frequencies on bubbles and registration of the scattered by bubbles acoustic field at the difference frequency. The use of this method is interesting since the scattered difference frequency wave has much lower attenuation in a liquid. The theoretical consideration of the method is given in the paper. The experimental examples confirming the theoretical equations, as well as the ability of the method to be applied in medical diagnostics and in technical applications on measurement of flow velocities in liquids with strong sound attenuation is described. It is shown that the Doppler spectrum form depends on bubble concentration velocity distribution in the primary acoustic beams crossing zone that allows one to measure the flow velocity distribution.

  15. Acoustic doppler methods for remote measurements of ocean flows - a review

    Digital Repository Service at National Institute of Oceanography (India)

    Joseph, A.

    The evolution of acoustic doppler methods for remote measurements of ocean flows has been briefly reviewed in historical perspective. Both Eulerian and profiling methods have been discussed. Although the first acoustic Doppler current meter has been...

  16. Nonintrusive Monitoring and Control of Metallurgical Processes by Acoustic Measurements

    Science.gov (United States)

    Yu, Hao-Ling; Khajavi, Leili Tafaghodi; Barati, Mansoor

    2011-06-01

    The feasibility of developing a new online monitoring technique based on the characteristic acoustic response of gas bubbles in a liquid has been investigated. The method is intended to monitor the chemistry of the liquid through its relation to the bubble sound frequency. A low-temperature model consisting of water and alcohol mixtures was established, and the frequency of bubbles rising under varying concentrations of methanol was measured. It was shown that the frequency of the sound created by bubble pulsation varies with the percentage of alcohol in water. The frequency drops sharply with the increase in methanol content up to 20 wt pct, after which the decreases is gradual. Surface tension seems to be a critical liquid property affecting the sound frequency through its two-fold effects on the bubble size and the pulsation domain. The dependence between the frequency and the liquid composition suggests the feasibility of developing an acoustic-based technique for process control purposes.

  17. Acoustic ship signature measurements by cross-correlation method.

    Science.gov (United States)

    Fillinger, Laurent; Sutin, Alexander; Sedunov, Alexander

    2011-02-01

    Cross-correlation methods were applied for the estimation of the power spectral density and modulation spectrum of underwater noise generated by moving vessels. The cross-correlation of the signal from two hydrophones allows the separation of vessel acoustic signatures in a busy estuary. Experimental data recorded in the Hudson River are used for demonstration that cross-correlation method measured the same ship noise and ship noise modulation spectra as conventional methods. The cross-correlation method was then applied for the separation of the acoustic signatures of two ships present simultaneously. Presented methods can be useful for ship traffic monitoring and small ship classification, even in noisy harbor environments. PMID:21361436

  18. Quantifying the information measured by neutron scattering instruments

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, M.W. [Rutherford Appleton Lab., Oxon (United Kingdom)

    1997-09-01

    The concept of the information content of a scientific measurement is introduced, and a theory is presented which enables the information that may be obtained by a neutron scattering instrument to be calculated. When combined with the time taken to perform the measurement the bandwidth of the instrument is obtained. This bandwidth is effectively a figure of merit which is of use in three respects: in the design of neutron instrumentation, the optimisation of measurements, and in the comparison of one instrument with another.

  19. RESERV: An Instrument for Measuring Real Estate Brokerage Service Quality

    OpenAIRE

    Susan Logan Nelson; Theron R. Nelson

    1995-01-01

    By applying the process utilized in the development of a generic service quality measurement instrument (SERVQUAL), an instrument to measure perceived levels of satisfaction with real estate brokerage service quality (RESERV) is developed. The RESERV instrument contains thirty-one items in seven dimensions and exhibits both high internal consistency and convergent validity. The findings, based upon a survey of home sellers, supports the notion that the real estate brokerage industry is not un...

  20. Instrumentation

    International Nuclear Information System (INIS)

    SCK-CEN's research and development programme on instrumentation involves the assessment and the development of sensitive measurement systems used within a radiation environment. Particular emphasis is on the assessment of optical fibre components and their adaptability to radiation environments. The evaluation of ageing processes of instrumentation in fission plants, the development of specific data evaluation strategies to compensate for ageing induced degradation of sensors and cable performance form part of these activities. In 2000, particular emphasis was on in-core reactor instrumentation applied to fusion, accelerator driven and water-cooled fission reactors. This involved the development of high performance instrumentation for irradiation experiments in the BR2 reactor in support of new instrumentation needs for MYRRHA, and for diagnostic systems for the ITER reactor

  1. Instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Decreton, M

    2001-04-01

    SCK-CEN's research and development programme on instrumentation involves the assessment and the development of sensitive measurement systems used within a radiation environment. Particular emphasis is on the assessment of optical fibre components and their adaptability to radiation environments. The evaluation of ageing processes of instrumentation in fission plants, the development of specific data evaluation strategies to compensate for ageing induced degradation of sensors and cable performance form part of these activities. In 2000, particular emphasis was on in-core reactor instrumentation applied to fusion, accelerator driven and water-cooled fission reactors. This involved the development of high performance instrumentation for irradiation experiments in the BR2 reactor in support of new instrumentation needs for MYRRHA, and for diagnostic systems for the ITER reactor.

  2. Simultaneous measurements of room-acoustic parameters using different measuring equipment?

    DEFF Research Database (Denmark)

    Halmrast, Tor; Gade, Anders Christian; Winsvold, Bjorn

    1998-01-01

    Often the results from different room-acoustic measurements in the same hall disagree, and the disagreement is just said to be due to different measuring equipment, or different rigging/temperature, etc. The room acoustic of the Oslo Concert Hall was measured simultaneously, using the following...... different measuring equipment: (1) MLS/MLSSA (Statsbygg), (2) Sweep-Tone (Tech. Univ. Denmark), and (3) Norsonic 840 with MLS+MatLab. For some of the measurements (4) Pistol and (5) Electrical Impulse were also used. The paper will compare the results from the different measuring equipment, for the most...... known room-acoustic parameters. For the reverberation time parameters RT and EDT, very good agreement was found between the three main measuring equipments. For Ts and C80 the agreement between these three is good/fair for the higher frequencies, but less good for the bass, especially C80. The...

  3. Determination of the elastic modulus of snow via acoustic measurements

    Science.gov (United States)

    Gerling, Bastian; van Herwijnen, Alec; Löwe, Henning

    2016-04-01

    The elastic modulus of snow is a key quantity from the viewpoint of avalanche research and forecasting, snow engineering or materials science in general. Since it is a fundamental property, many measurements have been reported in the literature. Due to differences in measurement methods, there is a lot of variation in the reported values. Especially values derived via computer tomography (CT) based numerical calculations using finite element methods are not corresponding to the results of other methods. The central issue is that CT based moduli are purely elastic whereas other methods may include viscoelastic deformation. In order to avoid this discrepancy we derived the elastic modulus of snow via wave propagation measurements and compared our results with CT based calculations. We measured the arrival times of acoustic pulses propagating through the snow samples to determine the P-wave velocity and in turn derive the elastic modulus along the direction of wave propagation. We performed a series of laboratory experiments to derive the P-wave modulus of snow in relation to density. The P-wave modulus ranged from 10 to 280 MPa for a snow density between 150 and 370 kg/m^3;. The moduli derived from the acoustic measurements correlated well with the CT-based values and both exhibited a power law trend over the entire density range. Encouraged by these results we used the acoustic method to investigate the temporal evolution of the elastic modulus. The rate of increase was very close to values mentioned in literature on the sintering rate of snow. Overall, our results are a first but important step towards a new measurement method to attain the elastic properties of snow.

  4. 27 CFR 24.36 - Instruments and measuring devices.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Instruments and measuring devices. 24.36 Section 24.36 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS WINE Administrative and Miscellaneous Provisions Authorities § 24.36 Instruments and measuring...

  5. 27 CFR 24.170 - Measuring devices and testing instruments.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Measuring devices and testing instruments. 24.170 Section 24.170 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS WINE Construction and Equipment § 24.170 Measuring devices and testing instruments....

  6. Optically Powered Temperature Measuring Instrument for Big Rotor①

    Institute of Scientific and Technical Information of China (English)

    ZHENGDezhong

    1997-01-01

    A micro-power consumption non-contact temperature measuring instrument for big rotos is introduced.As it solver very well the signal coupling under high speed rotation and power supply problem for probe,the instrument can realize persistent on-line temperature measurement for big rotor drived by the ordinary light transmitted by optical fiber under the room light.

  7. 40 CFR 1065.205 - Performance specifications for measurement instruments.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Performance specifications for... (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Measurement Instruments § 1065.205 Performance specifications for measurement instruments. Your test system as a whole must meet all the applicable...

  8. Combined surface acoustic wave and surface plasmon resonance measurement of collagen and fibrinogen layers

    CERN Document Server

    Friedt, J M; Francis, L; Zhou, C; Campitelli, A; Friedt, Jean-Michel; Denis, Frederic; Francis, Laurent; Zhou, Cheng; Campitelli, Andrew

    2003-01-01

    We use an instrument combining optical (surface plasmon resonance) and acoustic (Love mode acoustic wave device) real-time measurements on a same surface for the identification of water content in collagen and fibrinogen protein layers. After calibration of the surface acoustic wave device sensitivity by copper electrodeposition, the bound mass and its physical properties -- density and optical index -- are extracted from the complementary measurement techniques and lead to thickness and water ratio values compatible with the observed signal shifts. Such results are especially usefully for protein layers with a high water content as shown here for collagen on an hydrophobic surface. We obtain the following results: collagen layers include 70+/-20 % water and are 16+/-3 to 19+/-3 nm thick for bulk concentrations ranging from 30 to 300 ug/ml. Fibrinogen layers include 50+/-10 % water for layer thicknesses in the 6+/-1.5 to 13+/-2 nm range when the bulk concentration is in the 46 to 460 ug/ml range.

  9. Instrumentation

    International Nuclear Information System (INIS)

    SCK-CEN's R and D programme on instrumentation involves the development of advanced instrumentation systems for nuclear applications as well as the assessment of the performance of these instruments in a radiation environment. Particular emphasis is on the use of optical fibres as umbilincal links of a remote handling unit for use during maintanance of a fusion reacor, studies on the radiation hardening of plasma diagnostic systems; investigations on new instrumentation for the future MYRRHA accelerator driven system; space applications related to radiation-hardened lenses; the development of new approaches for dose, temperature and strain measurements; the assessment of radiation-hardened sensors and motors for remote handling tasks and studies of dose measurement systems including the use of optical fibres. Progress and achievements in these areas for 2001 are described

  10. 77 FR 37409 - Request for Domains, Instruments, and Measures for Development of a Standardized Instrument for...

    Science.gov (United States)

    2012-06-21

    ... 156.200(b)(5) (77 FR 18310, at 18469 (Mar. 27, 2012)) requires implementation of the enrollee... the domain, instrument or measure is publicly-available. Dated: May 15, 2012. Marilyn Tavenner, Acting... Instrument for Use in Public Reporting of Enrollee Satisfaction With Their Qualified Health Plan and...

  11. Calibration Base Lines for Electronic Distance Measuring Instruments (EDMI)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A calibration base line (CBL) is a precisely measured, straight-line course of approximately 1,400 m used to calibrate Electronic Distance Measuring Instruments...

  12. Acoustical measurements on stages of nine U.S. concert halls

    DEFF Research Database (Denmark)

    Gade, Anders Christian; Bradley, J S

    1993-01-01

    A measurement tour of nine U.S. concert halls included acoustical measurements on the stage of each hall. Two teams (from the National Research Council of Canada, and the Technical University of Denmark) made measurements of the acoustical quantities suggested by Gade: the ``support'' family of...... measures describing the acoustical conditions for the musicians on stage. This paper compares the results from the two measurement teams and discusses the influence of hall designs....

  13. Cosmological implications of baryon acoustic oscillation (BAO) measurements

    CERN Document Server

    Aubourg, Éric; Bautista, Julian E; Beutler, Florian; Bhardwaj, Vaishali; Bizyaev, Dmitry; Blanton, Michael; Blomqvist, Michael; Bolton, Adam S; Bovy, Jo; Brewington, Howard; Brinkmann, J; Brownstein, Joel R; Burden, Angela; Busca, Nicolás G; Carithers, William; Chuang, Chia-Hsun; Comparat, Johan; Cuesta, Antonio J; Dawson, Kyle S; Delubac, Timothée; Eisenstein, Daniel J; Font-Ribera, Andreu; Ge, Jian; Goff, J -M Le; Gontcho, Satya Gontcho A; Gott, J Richard; Gunn, James E; Guo, Hong; Guy, Julien; Hamilton, Jean-Christophe; Ho, Shirley; Honscheid, Klaus; Howlett, Cullan; Kirkby, David; Kitaura, Francisco S; Kneib, Jean-Paul; Lee, Khee-Gan; Long, Dan; Lupton, Robert H; Magaña, Mariana Vargas; Malanushenko, Viktor; Malanushenko, Elena; Manera, Marc; Maraston, Claudia; Margala, Daniel; McBride, Cameron K; Miralda-Escudé, Jordi; Myers, Adam D; Nichol, Robert C; Noterdaeme, Pasquier; Nuza, Sebastián E; Olmstead, Matthew D; Oravetz, Daniel; Pâris, Isabelle; Padmanabhan, Nikhil; Palanque-Delabrouille, Nathalie; Pan, Kaike; Pellejero-Ibanez, Marcos; Percival, Will J; Petitjean, Patrick; Pieri, Matthew M; Prada, Francisco; Reid, Beth; Roe, Natalie A; Ross, Ashley J; Ross, Nicholas P; Rossi, Graziano; Rubiño-Martín, Jose Alberto; Sánchez, Ariel G; Samushia, Lado; Santos, Ricardo Tanausú Génova; Scóccola, Claudia G; Schlegel, David J; Schneider, Donald P; Seo, Hee-Jong; Sheldon, Erin; Simmons, Audrey; Skibba, Ramin A; Slosar, Anže; Strauss, Michael A; Thomas, Daniel; Tinker, Jeremy L; Tojeiro, Rita; Vazquez, Jose Alberto; Viel, Matteo; Wake, David A; Weaver, Benjamin A; Weinberg, David H; Wood-Vasey, W M; Yèche, Christophe; Zehavi, Idit; Zhao, Gong-Bo

    2014-01-01

    We derive constraints on cosmological parameters and tests of dark energy models from the combination of baryon acoustic oscillation (BAO) measurements with cosmic microwave background (CMB) and Type Ia supernova (SN) data. We take advantage of high-precision BAO measurements from galaxy clustering and the Ly-alpha forest (LyaF) in the BOSS survey of SDSS-III. BAO data alone yield a high confidence detection of dark energy, and in combination with the CMB angular acoustic scale they further imply a nearly flat universe. Combining BAO and SN data into an "inverse distance ladder" yields a 1.7% measurement of $H_0=67.3 \\pm1.1$ km/s/Mpc. This measurement assumes standard pre-recombination physics but is insensitive to assumptions about dark energy or space curvature, so agreement with CMB-based estimates that assume a flat LCDM cosmology is an important corroboration of this minimal cosmological model. For open LCDM, our BAO+SN+CMB combination yields $\\Omega_m=0.301 \\pm 0.008$ and curvature $\\Omega_k=-0.003 \\pm ...

  14. Photo-acoustic tomography in a rotating measurement setting

    Science.gov (United States)

    Bal, Guillaume; Moradifam, Amir

    2016-10-01

    Photo-acoustic tomography (PAT) aims to leverage the photo-acoustic coupling between optical absorption of light sources and ultrasound (US) emission to obtain high contrast reconstructions of optical parameters with the high resolution of sonic waves. Quantitative PAT often involves a two-step procedure: first the map of sonic emission is reconstructed from US boundary measurements; and second optical properties of biological tissues are evaluated. We consider here a practical measurement setting in which such a separation does not apply. We assume that the optical source and an array of ultrasonic transducers are mounted on a rotating frame (in two or three dimensions) so that the light source rotates at the same time as the US measurements are acquired. As a consequence, we no longer have the option to reconstruct a map of sonic emission corresponding to a given optical illumination. We propose here a framework where the two steps are combined into one and an absorption map is directly reconstructed from the available US measurements.

  15. Instruments measuring blunted affect in schizophrenia: a systematic review.

    Directory of Open Access Journals (Sweden)

    Sanja Kilian

    Full Text Available Blunted affect, also referred to as emotional blunting, is a prominent symptom of schizophrenia. Patients with blunted affect have difficulty in expressing their emotions. The work of Abrams and Taylor and their development of the Rating Scale for Emotional Blunting in the late 1970's was an early indicator that blunted affect could indeed be assessed reliably. Since then, several new instruments assessing negative symptoms with subscales measuring blunted affect have been developed. In light of this, we aim to provide researchers and clinicians with a systematic review of the different instruments used to assess blunted affect by providing a comparison of the type, characteristics, administration and psychometric properties of these instruments. Studies reporting on the psychometric properties of instruments assessing blunted affect in patients with schizophrenia were included. Reviews and case studies were excluded. We reviewed 30 full-text articles and included 15 articles and 10 instruments in this systematic review. On average the instruments take 15-30 minutes to administer. We found that blunted affect items common across all instruments assess: gestures, facial expressions and vocal expressions. The CAINS Self-report Expression Subscale, had a low internal consistency score. This suggests that this sub-scale does not reliably assess patients' self-reported blunted affect symptoms and is likely due to the nature of blunted affect. Instruments correlated minimally with instruments measuring positive symptoms and more importantly with depression suggesting that the instruments distinguish between seemingly similar symptoms.

  16. Measuring Information Skills among Malaysian Youth Students: An Instrument Development

    OpenAIRE

    Aidah Abdul Karim; Parilah M. Shah; Rosseni Din; Mazalah Ahmad; Fariza Khalid

    2013-01-01

    This article described the development and testing of a research instrument, known as Information Skills Instrument which was designed to measure youth students’ abilities to search, access and use information from multiple sources in the context of academic works. The instrument was inductively developed from a literature review and tested with a sample of Malaysian school and college students. Principal Component Analysis was used to examine the dimensionality and Cronbach’s alpha was emplo...

  17. Measurement of stiffness of standing trees and felled logs using acoustics: A review.

    Science.gov (United States)

    Legg, Mathew; Bradley, Stuart

    2016-02-01

    This paper provides a review on the use of acoustics to measure stiffness of standing trees, stems, and logs. An outline is given of the properties of wood and how these are related to stiffness and acoustic velocity throughout the tree. Factors are described that influence the speed of sound in wood, including the different types of acoustic waves which propagate in tree stems and lumber. Acoustic tools and techniques that have been used to measure the stiffness of wood are reviewed. The reasons for a systematic difference between direct and acoustic measurements of stiffness for standing trees, and methods for correction, are discussed. Other techniques, which have been used in addition to acoustics to try to improve stiffness measurements, are also briefly described. Also reviewed are studies which have used acoustic tools to investigate factors that influence the stiffness of trees. These factors include different silvicultural practices, geographic and environmental conditions, and genetics.

  18. Instrument Measures Airflow Friction Without Contact

    Science.gov (United States)

    Monson, D. J.

    1983-01-01

    Dual beam laser interferometer determines airflow friction against body by measuring time-varying thickness of wind sheared oil film. Measurements yield skin friction between film and airstream. Errors from prerun oil flow, tunnel starting transients, and initial surface waves therefore eliminated.

  19. An Instrument to Measure Self-Righteousness.

    Science.gov (United States)

    Falbo, Toni; Belk, Sharyn S.

    A seven item Likert-type scale was developed to measure self-righteousness, defined as the conviction that one's beliefs and actions are correct, especially in contrast to the beliefs and actions of others. The Self Righteousness Questionnaire (SRQ) measures three components of self-righteousness: belittlement, acceptance, and uncertainty. The…

  20. Knee instruments and rating scales designed to measure outcomes

    OpenAIRE

    Rodríguez Merchán, E. Carlos

    2012-01-01

    In this article, the knee instruments and rating scales that are designed to measure outcomes are revised. Although the International Knee Documentation Committee Subjective Knee Form can be used as a general knee measure, no instrument is currently universally applicable across the spectrum of knee disorders and patient groups. Clinicians and researchers looking to use a patient-based score for measurement of outcomes must consider the specific patient population in which it has been evaluat...

  1. Advanced Measuring (Instrumentation Methods for Nuclear Installations: A Review

    Directory of Open Access Journals (Sweden)

    Wang Qiu-kuan

    2012-01-01

    Full Text Available The nuclear technology has been widely used in the world. The research of measurement in nuclear installations involves many aspects, such as nuclear reactors, nuclear fuel cycle, safety and security, nuclear accident, after action, analysis, and environmental applications. In last decades, many advanced measuring devices and techniques have been widely applied in nuclear installations. This paper mainly introduces the development of the measuring (instrumentation methods for nuclear installations and the applications of these instruments and methods.

  2. Communication quality and added value: a measurement instrument for municipalities

    OpenAIRE

    Vos, Marita

    2009-01-01

    Purpose – This study aims at a better understanding of communication quality and how it can be measured in the municipal context. A previously developed instrument for measuring communication in municipalities was tested and evaluated. Design/methodology/approach - The instrument draws on the balanced scorecard of Kaplan and Norton and quality control procedures as utilised by the European Foundation of Quality Measurement. For municipalities, communication quality can be defined as the d...

  3. Virtual Instrument for Emissions Measurement of Internal Combustion Engines

    OpenAIRE

    Armando Pérez; Rogelio Ramos; Gisela Montero; Marcos Coronado; Conrado García; Rubén Pérez

    2016-01-01

    The gases emissions measurement systems in internal combustion engines are strict and expensive nowadays. For this reason, a virtual instrument was developed to measure the combustion emissions from an internal combustion diesel engine, running with diesel-biodiesel mixtures. This software is called virtual instrument for emissions measurement (VIEM), and it was developed in the platform of LabVIEW 2010® virtual programming. VIEM works with sensors connected to a signal conditioning system, a...

  4. μDirac: an autonomous instrument for halocarbon measurements

    Directory of Open Access Journals (Sweden)

    B. Gostlow

    2009-09-01

    Full Text Available We describe a new instrument (μDirac capable of measuring halocarbons in the atmosphere. Portability, power efficiency and autonomy were critical requirements in the design, and the resulting instrument can be readily deployed unattended on a range of platforms: long duration balloon, aircraft, ship and ground based stations. The instrument is a temperature programmed gas chromatograph with electron capture detector (GC-ECD. The design requirements led to μDirac being built in-house with several novel features. It currently measures a range of halocarbons (CFCs and shorter-lived halocarbons having biogenic and anthropogenic sources with measurement precisions ranging from ∼1% sd (CCl4 to ∼9% sd (CH3I. Since the prototype instrument was first tested in 2005 the instrument has been proved in the field on technically challenging aircraft and ground based campaigns. Results from one aircraft and two ground-based deployments are described.

  5. μDirac: an autonomous instrument for halocarbon measurements

    Directory of Open Access Journals (Sweden)

    S. E. Yong

    2010-04-01

    Full Text Available We describe a new instrument (μDirac capable of measuring halocarbons in the atmosphere. Portability, power efficiency and autonomy were critical design requirements and the resulting instrument can be readily deployed unattended on a range of platforms: long duration balloon, aircraft, ship and ground-based stations. The instrument is a temperature programmed gas chromatograph with electron capture detector (GC-ECD. The design requirements led to μDirac being built in-house with several novel features. It currently measures a range of halocarbons (including short-lived tracers having biogenic and anthropogenic sources with measurement precision relative standard deviations ranging from ± 1% (CCl4 to ± 9% (CH3I. The prototype instrument was first tested in 2005 and the instrument has been proved in the field on technically challenging aircraft and ground-based campaigns. Results from an aircraft and a ground-based deployment are described.

  6. Self-contained instrument for measuring subterranean tunnel wall deflection

    Science.gov (United States)

    Rasmussen, Donald Edgar; Hof, Jr., Peter John

    1978-01-01

    The deflection of a subterranean tunnel is measured with a rod-like, self-contained instrument that is adapted to be inserted into a radially extending bore of the tunnel adjacent an end of the tunnel where the tunnel is being dug. One end of the instrument is anchored at the end of the bore remote from the tunnel wall, while the other end of the intrument is anchored adjacent the end of the wall in proximity to the tunnel wall. The two ends of the instrument are linearly displaceable relative to each other; the displacement is measured by a transducer means mounted on the instrument. Included in the instrument is a data storage means including a paper tape recorder periodically responsive to a parallel binary signal indicative of the measured displacement.

  7. Twin-tube practical acoustic thermometry: theory and measurements up to 1000 °C

    Science.gov (United States)

    Sutton, G.; Edwards, G.; Veltcheva, R.; de Podesta, M.

    2015-08-01

    We present details of a Practical Acoustic Thermometer (PAT), in which temperature is inferred from measurements of the speed of sound along acoustic waveguides. We describe both the theory of operation, and measurements on three devices at temperatures up to 1000 °C. Because the relationship between the speed of sound in a simple gas and absolute temperature is well understood, the mean temperature along a tube may be estimated from measurements of the frequency-dependent propagation constant. A PAT device made from two tubes of different lengths allows the temperature measurement region to be localised, creating an instrument functionally similar to conventional contact thermometers. Three twin-tube PAT devices were constructed and tested. PAT-A, made of silica, served to validate the technique with differences between the acoustic thermometer and a reference thermocouple of less than 2 °C at temperatures in the range from 100 °C to 1000 °C. PAT-B and PAT-C were made of Inconel-600, potentially more suitable for use in harsh environments. The Inconel devices deviated from expected behaviour in a reproducible manner, which after calibration allowed measurements with errors of less than  ±1 °C in the range to 700 °C. No drift was observed up to 700 °C. The drift observed during prolonged exposure to higher temperatures is described and its likely causes discussed. In the longer term, similar technology may provide a means for the measurement of temperature in harsh environments such as those found in the nuclear industry.

  8. LEDA beam diagnostics instrumentation: Beam current measurement

    International Nuclear Information System (INIS)

    The Low Energy Demonstration Accelerator (LEDA) facility located at Los Alamos National Laboratory (LANL) accelerates protons to an energy of 6.7 MeV and current of 100 mA operating in either a pulsed or cw mode. Two types of current measurements are used. The first is an AC or pulsed-current measurement which uses three LANL built toroids. They are placed in the beamline in such a way as to measure important transmission parameters and act as a differential current-loss machine protection system. The second system is a DC current measurement used to measure cw beam characteristics and uses toroids from Bergoz Inc. There are two of these systems, so they can also be used for transmission measurements. The AC system uses custom processing electronics whereas the DC system uses a modified Bergoz registered electronics system. Both systems feature data acquisition via a series of custom TMS320C40 Digital Signal Processing (DSP) boards. Of special interest to this paper is the operation of these systems, the calibration technique, the differential current loss measurements and fast-protection processing, current droop characteristics for the AC system, and existing system noise levels. This paper will also cover the DSP system operations and their interaction with the main accelerator control system

  9. Instrumentation, measurements, and experiments in fluids

    CERN Document Server

    Rathakrishnan, E

    2007-01-01

    NEED AND OBJECTIVE OF EXPERIMENTAL STUDY Some Fluid Mechanics MeasurementsMeasurement SystemsSome of the Important Quantities Associated with FluidFlow MeasurementsFUNDAMENTALS OF FLUID MECHANICSProperties of FluidsThermodynamic PropertiesSurface TensionAnalysis of Fluid FlowBasic and Subsidiary Laws for Continuous MediaKinematics of Fluid FlowStreamlinesPotential FlowViscous FlowsGas DynamicsWIND TUNNELSLow-Speed Wind TunnelsPower Losses in a Wind TunnelHigh-Speed Wind TunnelsHypersonic TunnelsInstrume

  10. Electrical instrument measures position and velocity of shock waves

    Science.gov (United States)

    Dannenberg, R. E.; Humphry, D. E.

    1971-01-01

    Instrument employs a sensor consisting of twin-electrode probe mounted in shock tube wall, with small dc voltage impressed across electrodes. Power supply, amplifier, and gate pulse generator complete the system. Instrument provides data for construction of wave diagrams, as well as measurement of shock velocity.

  11. An instrumentation for control and measurement of activated mineral samples

    International Nuclear Information System (INIS)

    A description is given of an instrumentation for control of a pneumatic tube system used to transport mineral samples for activation in a reactor and from there to a detector arrangement. A possible content of uranium in the samples can be seen from the radiation measured. The instrumentation includes a PDP-11 computer and a CAMAC crate

  12. Validation of an Instrument to Measure Political Attitudes.

    Science.gov (United States)

    Hepburn, Mary A.; Napier, John D.

    The Opinionnaire on Political Institutions and Participation (OPIP) was designed to measure six dimensions of the overall construct of political attitude. Three studies were undertaken to determine the validity and reliability of the instrument, and the OPIP was found to be a valid and reliable instrument for research and evaluations using…

  13. FINANCIAL ACCOUNTING MEASUREMENT: INSTRUMENTATION AND CALIBRATION

    OpenAIRE

    Salvary, Stanley C. W.

    2005-01-01

    In its Conceptual Framework (CF), the Financial Accounting Standards Board (FASB) has not identified the observable phenomena and was not able to identify a single measurement property in financial accounting. While identifying aspects of the observable phenomena in financial accounting, the FASB has indicated that there are five measurement attributes which are used in financial accounting and the result is a mixed-attributes model. Lacking a critical underlying theory, the FASB’s Conceptual...

  14. A Secure System Architecture for Measuring Instruments in Legal Metrology

    Directory of Open Access Journals (Sweden)

    Daniel Peters

    2015-03-01

    Full Text Available Embedded systems show the tendency of becoming more and more connected. This fact combined with the trend towards the Internet of Things, from which measuring instruments are not immune (e.g., smart meters, lets one assume that security in measuring instruments will inevitably play an important role soon. Additionally, measuring instruments have adopted general-purpose operating systems to offer the user a broader functionality that is not necessarily restricted towards measurement alone. In this paper, a flexible software system architecture is presented that addresses these challenges within the framework of essential requirements laid down in the Measuring Instruments Directive of the European Union. This system architecture tries to eliminate the risks general-purpose operating systems have by wrapping them, together with dedicated applications, in secure sandboxes, while supervising the communication between the essential parts and the outside world.

  15. Acoustic measurements of models of military style supersonic nozzle jets

    Institute of Scientific and Technical Information of China (English)

    Ching-Wen Kuo; Jérémy Veltin; Dennis K. McLaughlin

    2014-01-01

    Modern military aircraft jet engines are designed with variable-geometry nozzles to provide optimal thrust in different operating conditions, depending on the flight envelope. How-ever, acoustic measurements for such nozzles are scarce, due to the cost involved in making full-scale measurements and the lack of details about the exact geometries of these nozzles. Thus the present effort at Pennsylvania State University (PSU) in partnership with GE Aviation and the NASA Glenn Research Center is aiming to study and characterize the acoustic field produced by supersonic jets issuing from converging-diverging military style nozzles, and to identify and test promising noise reduction techniques. An equally important objective is to develop methodology for using data obtained from small-and moderate-scale experiments to reliably predict the full-scale engine noise. The experimental results presented show reasonable agreement between small-scale and medium-scale jets, as well as between heated jets and heat-simulated ones.

  16. Acoustic measurements of models of military style supersonic nozzle jets

    Directory of Open Access Journals (Sweden)

    Ching-Wen Kuo

    2014-02-01

    Full Text Available Modern military aircraft jet engines are designed with variable-geometry nozzles to provide optimal thrust in different operating conditions, depending on the flight envelope. However, acoustic measurements for such nozzles are scarce, due to the cost involved in making full-scale measurements and the lack of details about the exact geometries of these nozzles. Thus the present effort at Pennsylvania State University (PSU in partnership with GE Aviation and the NASA Glenn Research Center is aiming to study and characterize the acoustic field produced by supersonic jets issuing from converging-diverging military style nozzles, and to identify and test promising noise reduction techniques. An equally important objective is to develop methodology for using data obtained from small- and moderate-scale experiments to reliably predict the full-scale engine noise. The experimental results presented show reasonable agreement between small-scale and medium-scale jets, as well as between heated jets and heat-simulated ones.

  17. Classification of heart valve condition using acoustic measurements

    Energy Technology Data Exchange (ETDEWEB)

    Clark, G. [Lawrence Livermore National Lab., CA (United States)

    1994-11-15

    Prosthetic heart valves and the many great strides in valve design have been responsible for extending the life spans of many people with serious heart conditions. Even though the prosthetic valves are extremely reliable, they are eventually susceptible to long-term fatigue and structural failure effects expected from mechanical devices operating over long periods of time. The purpose of our work is to classify the condition of in vivo Bjork-Shiley Convexo-Concave (BSCC) heart valves by processing acoustic measurements of heart valve sounds. The structural failures of interest for Bscc valves is called single leg separation (SLS). SLS can occur if the outlet strut cracks and separates from the main structure of the valve. We measure acoustic opening and closing sounds (waveforms) using high sensitivity contact microphones on the patient`s thorax. For our analysis, we focus our processing and classification efforts on the opening sounds because they yield direct information about outlet strut condition with minimal distortion caused by energy radiated from the valve disc.

  18. Utilization of old vibro-acoustic measuring equipment to grasp basic concepts of vibration measurements

    DEFF Research Database (Denmark)

    Darula, Radoslav

    2013-01-01

    The aim of the paper is to show that even old vibro-acoustic (analog) equipment can be used as a very suitable teaching equipment to grasp basic principles of measurements in an era, when measurement equipments are more-or-less treated as ‘black-boxes’, i.e. the user cannot see directly how...

  19. Measurement of sexual functioning after spinal cord injury: preferred instruments

    DEFF Research Database (Denmark)

    Alexander, Marcalee Sipski; Brackett, Nancy L; Bodner, Donald;

    2009-01-01

    into male and female sexual function, male reproductive function, and female reproductive function. The instruments that have been used most frequently to measure these aspects of sexual function over the past 5 years were identified by expert consensus. Finally, these instruments were subjected to a......BACKGROUND/OBJECTIVE: To determine the utility of certain instruments to assess sexuality and fertility after SCI, an expert panel identified key areas to study and evaluated available instruments. These were rated according to certain predefined criteria. METHODS: The authors divided sexual issues...... critical review. RESULTS: The Female Sexual Function Index (FSFI), measurement of vaginal pulse amplitude (VPA), the International Index of Erectile Function (IIEF), and the measurement of ejaculatory function and semen quality were considered appropriate measures to assess sexual responses and...

  20. Novel Instrumentation for In Situ Combustion Measurements Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of the Phase I is to develop, demonstrate and test a novel instrument based on laser absorption diagnostics for fast, in situ measurements of...

  1. Astronomical Polarimetry : new concepts, new instruments, new measurements & observations

    NARCIS (Netherlands)

    Snik, F.

    2009-01-01

    All astronomical sources are polarized to some degree. Polarimetry is therefore a powerful astronomical technique. It furnishes unique diagnostics of e.g. magnetic fields and scattering media. This thesis presents new polarimetric concepts, instruments, and measurements targeting astronomical scienc

  2. Neutron measuring instruments for radiation protection

    International Nuclear Information System (INIS)

    The present report deals with selected topics from the field of neutron dosimetry for radiation protection connected with the work of the subcommittee 6802 in the Standards Committee on Radiology (NAR) of the German Standards Institute (DIN). It is a sort of material collection. The topics are: 1. Measurement of the absorbed-energy dose by a) ionization chambers in fields of mixed radiation and b) recoil-proton proportional counting tubes. 2. Measurement of the equivalent dose, neutron monitors, combination methods by a) rem-meters, b) recoil-proton counting tubes, c) recombination method, tissue-equivalent proportional counters, activation methods for high energies in fields of mixed radiation, d) personnel dosimetry by means of ionization chambers and counting tubes, e) dosimetry by means of activation methods, nuclear track films, nonphotographic nuclear track detectors and solid-state dosimeters. (orig./HP)

  3. MODERN INSTRUMENTS FOR MEASURING ORGANIZATIONAL PERFORMANCE

    OpenAIRE

    RADU CATALINA; BADEA FLORICA; GRIGORE ANA-MARIA

    2010-01-01

    Any significant management action can be assessed both in terms of success of immediate goals and as effect of the organization ability to embrace change. Market competition intensifies with the development of Romanian society and its needs. Companies that offer different products and services need to impose certain advantages and to increase their performances. The paper will present modern tools for measuring and evaluating organizational performance, namely: Balanced Scorecard, Deming mode...

  4. Metric Characteristics of One Battery of Motoric Measuring Instruments

    OpenAIRE

    Damjan Jakšić; Radenko Matić; Milan Cvetković

    2013-01-01

    The paper at hand presents the results of research, which is carried out on 161 male students of Faculty of Sport and Physical Education, University of Novi Sad, Serbia. System of 11 composite measuring instruments was applied on them and each of tests had three replications. Analysis of metric characteristics was done on two ways: in real and in Guttman’s image space. Finally, it could be concluded that battery of motor measure instruments is absolutely appropriate for this sample of partici...

  5. Correcting acoustic Doppler current profiler discharge measurement bias from moving-bed conditions without global positioning during the 2004 Glen Canyon Dam controlled flood on the Colorado River

    Science.gov (United States)

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

    2007-01-01

    Discharge measurements were made by acoustic Doppler current profiler at two locations on the Colorado River during the 2004 controlled flood from Glen Canyon Dam, Arizona. Measurement hardware and software have constantly improved from the 1980s such that discharge measurements by acoustic profiling instruments are now routinely made over a wide range of hydrologic conditions. However, measurements made with instruments deployed from moving boats require reliable boat velocity data for accurate measurements of discharge. This is normally accomplished by using special acoustic bottom track pings that sense instrument motion over bottom. While this method is suitable for most conditions, high current flows that produce downstream bed sediment movement create a condition known as moving bed that will bias velocities and discharge to lower than actual values. When this situation exists, one solution is to determine boat velocity with satellite positioning information. Another solution is to use a lower frequency instrument. Discharge measurements made during the 2004 Glen Canyon controlled flood were subject to moving-bed conditions and frequent loss of bottom track. Due to site conditions and equipment availability, the measurements were conducted without benefit of external positioning information or lower frequency instruments. This paper documents and evaluates several techniques used to correct the resulting underestimated discharge measurements. One technique produces discharge values in good agreement with estimates from numerical model and measured hydrographs during the flood. ?? 2007, by the American Society of Limnology and Oceanography, Inc.

  6. MODERN INSTRUMENTS FOR MEASURING ORGANIZATIONAL PERFORMANCE

    Directory of Open Access Journals (Sweden)

    RADU CATALINA

    2010-12-01

    Full Text Available Any significant management action can be assessed both in terms of success of immediate goals and as effect of the organization ability to embrace change. Market competition intensifies with the development of Romanian society and its needs. Companies that offer different products and services need to impose certain advantages and to increase their performances. The paper will present modern tools for measuring and evaluating organizational performance, namely: Balanced Scorecard, Deming model and Baldrige model. We also present an example for Balance Scorecard, of an organizations belonging to the cosmetics industry.

  7. A mixed method for measuring low-frequency acoustic properties of macromolecular materials

    Institute of Scientific and Technical Information of China (English)

    LIU; Hongwei; YAO; Lei; ZHAO; Hong; ZHANG; Jichuan; XUE; Zhaohong

    2006-01-01

    A mixed method for measuring low-frequency acoustic properties of macromolecular materials is presented.The dynamic mechanical parameters of materials are first measured by using Dynamic Mechanical Thermal Apparatus(DMTA) at low frequencies,usually less than 100 Hz; then based on the Principles of Time-Temperature Super position (TTS),these parameters are extended to the frequency range that acousticians are concerned about,usually from hundreds to thousands of hertz; finally the extended dynamic mechanical parameters are transformed into acoustic parameters with the help of acoustic measurement and inverse analysis.To test the feasibility and accuracy,we measure a kind of rubber sample in DMTA and acquire the basic acoustic parameters of the sample by using this method.While applying the basic parameters to calculating characteristics of the sample in acoustic pipe,a reasonable agreement of sound absorption coefficients is obtained between the calculations and measurements in the acoustic pipe.

  8. Aero-acoustic Measurement and Monitoring of Dynamic Pressure Fields Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This innovative and practical measurement and monitoring system optimally defines dynamic pressure fields, including sound fields. It is based on passive acoustic...

  9. Acoustic Environment of Admiralty Inlet: Broadband Noise Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Jinshan; Deng, Zhiqun; Martinez, Jayson J.; Carlson, Thomas J.; Myers, Joshua R.; Weiland, Mark A.; Jones, Mark E.

    2011-09-30

    Admiralty Inlet has been selected as a potential tidal energy site. It is located near shipping lanes, is a highly variable acoustic environment, and is frequented by the highly endangered southern resident killer whale (SRKW). Resolving environmental impacts is the first step to receiving approval to deploy tidal turbines at Admiralty Inlet. Of particular concern is the potential for blade strike or other negative interactions between the SRKW and the tidal turbine. A variety of technologies including passive and active monitoring systems are being considered as potential tools to determine the presence of SRKW in the vicinity of the turbines. Broadband noise level measurements are critical for the determination of design and operation specifications of all marine and hydrokinetic energy capture technologies. Acoustic environment data at the proposed site was acquired at different depths using a cabled vertical line array (VLA) with four calibrated hydrophones. The sound pressure level (SPL) power spectrum density was estimated based on the fast Fourier transform. This study describes the first broadband SPL measurements for this site at different depths with frequency ranging from 10 kHz to 480 kHz in combination with other information. To understand the SPL caused by this bedload transport, three different pressure sensors with temperature and conductivity were also assembled on the VLA to measure the conditions at the hydrophone deployment depth. The broadband SPL levels at frequency ranges of 3 kHz to 7 kHz as a function of depth were estimated. Only the hydrophone at an average depth of 40 m showed the strong dependence of SPL with distance from the bottom, which was possibly caused by the cobbles shifting on the seabed. Automatic Identification System data were also studied to understand the SPL measurements.

  10. Unsteady 2-phase flow instrumentation and measurement

    Science.gov (United States)

    Bernier, R. J.

    The performance of a transverse field electromagnetic flowmeter in a steady two phase flow was investigated analytically for a disperse and an annular flow regime. The flowmeter output voltage was found to be proportional to the mean velocity of the liquid phase. Experiments in a steady air water mixture showed good agreement with the analysis. An impedance void fraction meter was designed and built to conduct measurements of unsteady void fractions. Short electrodes excited by voltages of opposite polarity were used in combination with a highly sensitive signal processor. The steady state calibration indicated that the meter was somewhat sensitive to the void fraction distribution for the bubbly flow regime. However, the transition to a churn turbulent regime greatly affected the meer steady state response. The dynamic capability of the void fraction meter was estimated by comparison of the statistical properties of the voltage fluctuations in a nominally steady bubbly flow with those of a shot noise process.

  11. Radiometric instrumentation and measurements guide for photovoltaic performance testing

    Energy Technology Data Exchange (ETDEWEB)

    Myers, D.

    1997-04-01

    The Photovoltaic Module and Systems Performance and Engineering Project at the National Renewable Energy Laboratory performs indoor and outdoor standardization, testing, and monitoring of the performance of a wide range of photovoltaic (PV) energy conversion devices and systems. The PV Radiometric Measurements and Evaluation Team (PVSRME) within that project is responsible for measurement and characterization of natural and artificial optical radiation which stimulates the PV effect. The PV manufacturing and research and development community often approaches project members for technical information and guidance. A great area of interest is radiometric instrumentation, measurement techniques, and data analysis applied to understanding and improving PV cell, module, and system performance. At the Photovoltaic Radiometric Measurements Workshop conducted by the PVSRME team in July 1995, the need to communicate knowledge of solar and optical radiometric measurements and instrumentation, gained as a result of NREL`s long-term experiences, was identified as an activity that would promote improved measurement processes and measurement quality in the PV research and manufacturing community. The purpose of this document is to address the practical and engineering need to understand optical and solar radiometric instrument performance, selection, calibration, installation, and maintenance applicable to indoor and outdoor radiometric measurements for PV calibration, performance, and testing applications. An introductory section addresses radiometric concepts and definitions. Next, concepts essential to spectral radiometric measurements are discussed. Broadband radiometric instrumentation and measurement concepts are then discussed. Each type of measurement serves as an important component of the PV cell, module, and system performance measurement and characterization process.

  12. Acoustic measurements above a plate carrying Lamb waves

    CERN Document Server

    Talberg, Andreas Sørbrøden

    2016-01-01

    This article presents a set of acoustic measurements conducted on the Statoil funded Behind Casing Logging Set-Up, designed by SINTEF Petroleum Research to resemble an oil well casing. A set of simple simulations using COMSOL Multiphysics were also conducted and the results compared with the measurements. The experiments consists of measuring the pressure wave radiated of a set of Lamb waves propagating in a 3 mm thick steel plate, using the so called pitch-catch method. The Lamb waves were excited by a broadband piezoelectric immersion transducer with center frequency of 1 MHz. Through measurements and analysis the group velocity of the fastest mode in the plate was found to be 3138.5 m/s. Measuring the wave radiated into the water in a grid consisting of 8x33 measuring points, the spreading of the plate wave normal to the direction of propagation was investigated. Comparing the point where the amplitude had decreased 50 % relative to the amplitude measured at the axis pointing straight forward from the tran...

  13. Estimating discharge using multi-level velocity data from acoustic doppler instruments

    DEFF Research Database (Denmark)

    Poulsen, Jane Bang; Rasmussen, Keld Rømer; Ovesen, Niels Bering

    In the majority of Danish streams, weed growth affects the effective stream width and bed roughness thus imposes temporal variations on the stage-discharge relationship. Small stream-gradients and firm ecology based restrictions prevent that hydraulic structures are made at the discharge stations...... and thus remove or limit such influences. Hence, estimation of the hydrograph is based on continuous stream gauging combined with monthly control measurements of discharge and assuming linear variation of bed roughness between the monthly measurements. As a result, any non-linear drift in weed density...... been placed at the main discharge station in one of the largest Danish catchments (the Skjern). The instruments were set out in early February 2010 during the winter season and have been running since then. The long term average discharge at the station is near 14 m3/s and the cross sectional profile...

  14. Precise measurement technique for the stable acoustic cavitation bubble

    Institute of Scientific and Technical Information of China (English)

    HUANG Wei; CHEN Weizhong; LIU Yanan; GAO Xianxian; JIANG Lian; XU Junfeng; ZHU Yifei

    2005-01-01

    Based on the periodic oscillation of the stable acoustic cavitation bubble, we present a precise measurement technique for the bubble evolution. This technique comprises the lighting engineering of pulsing laser beam whose phase can be digitally shifted, and the long distance microphotographics. We used a laser, an acousto-optic modulator, a pulse generator, and a long distance microscope. The evolution of a levitated bubble can be directly shown by a series of bubble's images at different phases. Numerical simulation in the framework of the Rayleigh-Plesset bubble dynamics well supported the experimental result, and the ambient radius of the bubble, an important parameter related to the mass of the gas inside the bubble, was obtained at the same time.

  15. Thermodynamic properties of liquid gallium from picosecond acoustic velocity measurements

    International Nuclear Information System (INIS)

    Due to discrepancies in the literature data the thermodynamic properties of liquid gallium are still in debate. Accurate measurements of adiabatic sound velocities as a function of pressure and temperature have been obtained by the combination of laser picosecond acoustics and surface imaging on sample loaded in diamond anvil cell. From these results the thermodynamic parameters of gallium have been extracted by a numerical procedure up to 10 GPa and 570 K. It is demonstrated that a Murnaghan equation of state accounts well for the whole data set since the isothermal bulk modulus BT has been shown to vary linearly with pressure in the whole temperature range. No evidence for a previously reported liquid–liquid transition has been found in the whole pressure and temperature range explored. (paper)

  16. Surface Acoustic Wave Vibration Sensors for Measuring Aircraft Flutter

    Science.gov (United States)

    Wilson, William C.; Moore, Jason P.; Juarez, Peter D.

    2016-01-01

    Under NASA's Advanced Air Vehicles Program the Advanced Air Transport Technology (AATT) Project is investigating flutter effects on aeroelastic wings. To support that work a new method for measuring vibrations due to flutter has been developed. The method employs low power Surface Acoustic Wave (SAW) sensors. To demonstrate the ability of the SAW sensor to detect flutter vibrations the sensors were attached to a Carbon fiber-reinforced polymer (CFRP) composite panel which was vibrated at six frequencies from 1Hz to 50Hz. The SAW data was compared to accelerometer data and was found to resemble sine waves and match each other closely. The SAW module design and results from the tests are presented here.

  17. Measurement of the Acoustic Nonlinearity Parameter for Biological Media.

    Science.gov (United States)

    Cobb, Wesley Nelson

    In vitro measurements of the acoustic nonlinearity parameter are presented for several biological media. With these measurements it is possible to predict the distortion of a finite amplitude wave in biological tissues of current diagnostic and research interest. The measurement method is based on the finite amplitude distortion of a sine wave that is emmitted by a piston source. The growth of the second harmonic component of this wave is measured by a piston receiver which is coaxial with and has the same size as the source. The experimental measurements and theory are compared in order to determine the nonlinearity parameter. The density, sound speed, and attenuation for the medium are determined in order to make this comparison. The theory developed for this study accounts for the influence of both diffraction and attenuation on the experimental measurements. The effects of dispersion, tissue inhomogeneity and gas bubbles within the excised tissues are studied. To test the measurement method, experimental results are compared with established values for the nonlinearity parameter of distilled water, ethylene glycol and glycerol. The agreement between these values suggests that the measurement uncertainty is (+OR-) 5% for liquids and (+OR-) 10% for solid tissues. Measurements are presented for dog blood and bovine serum albumen as a function of concentration. The nonlinearity parameters for liver, kidney and spleen are reported for both human and canine tissues. The values for the fresh tissues displayed little variation (6.8 to 7.8). Measurements for fixed, normal and cirrhotic tissues indicated that the nonlinearity parameter does not depend strongly on pathology. However, the values for fixed tissues were somewhat higher than those of the fresh tissues.

  18. Measuring monetary policy expectations from financial market instruments

    OpenAIRE

    Joyce, Michael; Relleen, Jonathan; Sorensen, Steffen

    2008-01-01

    This paper reviews the main instruments and associated yield curves that can be used to measure financial market participants’ expectations of future UK monetary policy rates. We attempt to evaluate these instruments and curves in terms of their ability to forecast policy rates over the period from October 1992, when the United Kingdom first adopted an explicit inflation target, to March 2007. We also investigate several model-based methods of estimating forward term premia, in order to calcu...

  19. Developing an instrument to measure dental flossing in Iranian adolescents

    OpenAIRE

    Taymoori, Parvaneh; Fallahi, Arezoo; Berry, Tanya

    2013-01-01

    Abstract. Preventable risk factors for oral health diseases are linked to related self-efficacy, attitudes and behaviors. The purpose of this study was to develop an instrument to measure oral self-care, based on the Transtheoretical model and to report on the psychometric testing of the instrument. The findings from qualitative research from Sanandaj, Iran, was used to generate the initial items. Construct validity was tested using principal component analysis to extract factors. Results: Fa...

  20. A miniDOAS instrument optimised for ammonia field measurements

    OpenAIRE

    Sintermann, Jörg; Dietrich, Klaus; Häni, Christoph; Bell, Michael; Jocher, Markus; Neftel, Albrecht

    2016-01-01

    We present a differential optical absorption spectroscopy (DOAS) instrument, called "miniDOAS", optimised for optical open-path field-measurements of ambient ammonia (NH3) alongside nitrogen oxide (NO) and sulfur dioxide (SO2). The instrument is a further development of the miniDOAS presented by Volten et al. (2012). We use a temperature-controlled spectrometer, a deuterium light source and a modified optical arrangement. The system was set up in a robust, field-deployable, ...

  1. Direct and indirect measurement of rain drop size distributions using an acoustic water tank disdrometer

    International Nuclear Information System (INIS)

    Several rain drop size distribution (DSD) point measurement technologies exist, but all are unable to sample either short timescales or the large drop tail of the DSD due to inherent instrumental limitations. The development of an acoustic water tank disdrometer (AWTD) is described, which improves the sampling statistics by increasing the catchment area. This is achieved by distinguishing individual drops, locating them on the surface of the tank then converting the impact pressure into a drop size. Wavelet decomposition is used to distinguish the broadband, short duration impact events and a fast multilateration method is used to position the drop. Issues relating to the different types of noise are also investigated and mitigated. Also, further work on inverting the measured acoustic intensity into a DSD, by fitting sampling distributions, is presented. Six months of data were collected in the Eastern UK. The AWTD then converted the data into DSDs and the results were compared to a commercially available co-located laser precipitation monitor. The sampling errors are far lower due to the increased catchment size, and hence the large drop sized tail of the DSD is greatly improved. DSD results compare favourably to other disdrometers for drop diameters greater than 1.8 mm. Below this size individual drops become increasingly difficult to detect and are underestimated. (paper)

  2. Ultrasonic flow measurement and wall acoustic impedance effects.

    Science.gov (United States)

    Willatzen, M

    2004-03-01

    An examination of the influence of wall acoustic impedance effects on sound propagation in flowing liquids confined by cylindrical walls is presented. Special focus is given to the importance of the wall acoustic impedance value for ultrasonic flow meter performance. The mathematical model presented allows any radially-dependent axial flow profile to be examined in the linear flow acoustics regime where fluid flow speed is much smaller than the fluid sound speed everywhere in the fluid medium. PMID:14996531

  3. Instrumental developments in high-resolution neutron measurements

    International Nuclear Information System (INIS)

    Instrumental developments in high-resolution neutron measurements are discussed from the viewpoint of time-of-flight experiments with broad spectrum neutron sources. Discussions are mainly restricted to the energy range above approx.= 100 keV, where most rapid progress has been made in recent years. The presentation begins with a few typical example of neutron investigations for which high-resolution measurements are important. Experimental conditions necessary to perform high-resolution measurements are briefly summarized. The relevant instrumental developments are then discussed in detail, and further improvements currently under active development are outlined. (orig.)

  4. Thickness measurement instrument with memory storage of multiple calibrations

    International Nuclear Information System (INIS)

    An improved backscatter instrument for the nondestructive measurement of coatings on a substrate is described. A memory having selectable memory areas, each area having stored intelligence available which is determinative of the shape of a functional plot of coating thickness versus backscatter counts per minute unique for each particular combination of emitting isotope, substrate material, coating material and physical characteristics of the measuring instrument. A memory selector switch connects a selected area of memory to a microprocessor operating under program control whereby the microprocessor reads the intelligence stored at the selected area and converts the backscattered count of the coating being measured into indicia of coating thickness

  5. Quantifying and handling errors in instrumental measurements using the measurement error theory

    DEFF Research Database (Denmark)

    Andersen, Charlotte Møller; Bro, R.; Brockhoff, P.B.

    2003-01-01

    Measurement error modelling is used for investigating the influence of measurement/sampling error on univariate predictions of water content and water-holding capacity (reference measurement) from nuclear magnetic resonance (NMR) relaxations (instrumental) measured on two gadoid fish species...

  6. Measuring instruments in economics and the velocity of money

    OpenAIRE

    Morgan, Mary S.

    2006-01-01

    Economic measurements are generated by complicated systems of measurement involving economic and bureaucratic processes. Whether these measuring instruments produce reliable numbers: ‘facts’ that travel well, depends on the qualities of these systems. Ideas from metrology, and from the philosophy and sociology of science, are used to analyse various attempts to measure the velocity of money ranging from the 17th to the 20th centuries. These historical experiences suggest that numerical facts ...

  7. Toward Development of a Generalized Instrument to Measure Andragogy

    Science.gov (United States)

    Holton, Elwood F., III; Wilson, Lynda Swanson; Bates, Reid A.

    2009-01-01

    Andragogy has emerged as one of the dominant frameworks for teaching adults during the past 40 years. A major and glaring gap in andragogy research is the lack of a measurement instrument that adequately measures both andragogical principles and process design elements. As a result, no definitive empirical test of the theory has been possible. The…

  8. An Assessment Instrument to Measure Geospatial Thinking Expertise

    Science.gov (United States)

    Huynh, Niem Tu; Sharpe, Bob

    2013-01-01

    Spatial thinking is fundamental to the practice and theory of geography, however there are few valid and reliable assessment methods in geography to measure student performance in spatial thinking. This article presents the development and evaluation of a geospatial thinking assessment instrument to measure participant understanding of spatial…

  9. Acoustic measurements of F-16 aircraft operating in hush house, NSN 4920-02-070-2721

    Science.gov (United States)

    Miller, V. R.; Plzak, G. A.; Chinn, J. M.

    1981-09-01

    The purpose of this test program was to measure the acoustic environment in the hush house facility located at Kelly Air Force Base, Texas, during operation of the F-16 aircraft to ensure that aircraft structural acoustic design limits were not exceeded. The acoustic measurements showed that no sonic fatigue problems are anticipated with the F-16 aircraft aft fuselage structure during operation in the hush house. The measured acoustic levels were less than those measured in an F-16 aircraft water cooled hush house at Hill AFB, but were increased over that measured during ground run up. It was recommended that the acoustic loads measured in this program should be specified in the structural design criteria for aircraft which will be subjected to hush house operation or defining requirements for associated equipment.

  10. Outcomes Measurement in Voice Disorders: Application of an Acoustic Index of Dysphonia Severity

    Science.gov (United States)

    Awan, Shaheen N.; Roy, Nelson

    2009-01-01

    Purpose: The purpose of this experiment was to assess the ability of an acoustic model composed of both time-based and spectral-based measures to track change following voice disorder treatment and to serve as a possible treatment outcomes measure. Method: A weighted, four-factor acoustic algorithm consisting of shimmer, pitch sigma, the ratio of…

  11. Postoperative improvement in acoustic rhinometry measurements after septoplasty correlates with long-term satisfaction

    DEFF Research Database (Denmark)

    Toyserkani, N M; Frisch, Thomas; von Buchwald, Christian

    2013-01-01

    Not much is known about long-term satisfaction of septoplasty. Our goal was to compare pre- and postoperative acoustic rhinometry measurements with satisfaction 11 years after surgery.......Not much is known about long-term satisfaction of septoplasty. Our goal was to compare pre- and postoperative acoustic rhinometry measurements with satisfaction 11 years after surgery....

  12. Integrated measurements of acoustical and optical thin layers I: Vertical scales of association

    Science.gov (United States)

    Benoit-Bird, Kelly J.; Moline, Mark A.; Waluk, Chad M.; Robbins, Ian C.

    2010-01-01

    This study combined measurements from multiple platforms with acoustic instruments on moorings and on a ship and optics on a profiler and an autonomous underwater vehicle (AUV) to examine the relationships between fluorescent, bioluminescent, and acoustically scattering layers in Monterey Bay during nighttime hours in July and August of 2006 and May of 2008. We identified thin bioluminescent layers that were strongly correlated with acoustic scattering at the same depth but were part of vertically broad acoustic features, suggesting layers of unique composition inside larger biomass features. These compositional thin layers nested inside larger biomass features may be a common ecosystem component and are likely to have significant ecological impacts but are extremely difficult to identify as most approaches capable of the vertical scales of measurement necessary for the identification of sub-meter scale patterns assess bulk properties rather than specific layer composition. Measurements of multiple types of thin layers showed that the depth offset between thin phytoplankton and zooplankton layers was highly variable with some layers found at the same depth but others found up to 16 m apart. The vertical offset between phytoplankton and zooplankton thin layers was strongly predicted by the fraction of the water column fluorescence contained within a thin phytoplankton layer. Thin zooplankton layers were only vertically associated with thin phytoplankton layers when the phytoplankton in a layer accounted for more than about 18-20% of the water column chlorophyll. Trophic interactions were likely occurring between phytoplankton and zooplankton thin layers but phytoplankton thin layers were exploited by zooplankton only when they represented a large fraction of the available phytoplankton, suggesting zooplankton have some knowledge of the available food over the entire water column. The horizontal extent of phytoplankton layers, discussed in the second paper in this

  13. Comparisons of auditorium acoustics measurements as a function of location in halls (A)

    DEFF Research Database (Denmark)

    Bradley, J. S.; Gade, Anders Christian; Siebein, G W

    1993-01-01

    parallel measurements of a number of modern room acoustics quantities using different equipment and measurement procedures. These results are compared on a seat-by-seat basis and the differences are explained in terms of earlier systematic studies of the effects of measurement procedure details....... The measurement results were also used to examine the influence of different measurement equipment and measurement procedures on the within hall variations of the various acoustical quantities. [Work partially supported by the Concert Hall Research Group.]...

  14. The Acoustic Properties of Water Submerged Lodgepole Pine (Pinus contorta and Spruce (Picea spp. Wood and Their Suitability for Use as Musical Instruments

    Directory of Open Access Journals (Sweden)

    Calvin Hilde

    2014-08-01

    Full Text Available Wood is a common material used for the manufacture of many products, and submerged wood, in particular, has been used in niche markets and musical instruments. In order to examine if submerged wood in British Columbia, Canada, would be appropriate for use as musical instruments, a study was performed in 2007 on submerged wood from Ootsa Lake, British Columbia, Canada. The results of that study showed the wood was not suitable for musical instruments. In this paper, the wood samples were allowed to age untouched in a laboratory setting and were then retested under the hypothesis that physical acoustic characteristics would improve. It was shown, however, that acoustic properties became less adequate after being left to dry over time. This article describes the density, speed of sound, acoustic constant and characteristic impedance properties for submerged wood and a comparison is made for different applications for musical instruments.

  15. The measurement of instrumental ADL: content validity and construct validity

    DEFF Research Database (Denmark)

    Avlund, K; Schultz-Larsen, K; Kreiner, S

    1993-01-01

    A new measure of Instrumental Activities of Daily Living (IADL), which is able to discriminate among the large group of elderly who do not depend on help, was tested for content validity and construct validity. Most assessments of functional ability include Physical ADL (PADL) and Instrumental ADL....... The measure of Instrumental ADL included 30 activities in relation to tiredness and reduced speed. Construct validity was tested by the Rasch model for item analysis; internal validity was specifically addressed by assessing the homogeneity of items under different conditions. The Rasch item analysis of IADL...... showed that 14 items could be combined into two qualitatively different additive scales. The IADL-measure complies with demands for content validity, distinguishes between what the elderly actually do, and what they are capable of doing, and is a good discriminator among the group of elderly persons who...

  16. Comparison of nanoparticle measurement instruments for occupational health applications

    International Nuclear Information System (INIS)

    Nanoparticles are used in many applications because of their novel properties compared to bulk material. A growing number of employees are working with nanomaterials and their exposure to nanoparticles trough inhalation must be evaluated and monitored continuously. However, there is an ongoing debate in the scientific literature about what are the relevant parameters to measure to evaluate exposure to level. In this study, three types of nanoparticles (ammonium sulphate, synthesised TiO2 agglomerates and aerosolised TiO2 powder, modes in a range of 30–140 nm mobility size) were measured with commonly used aerosol measurement instruments: scanning and fast mobility particle sizers (SMPS, FMPS), electrical low pressure impactor (ELPI), condensation particle counter (CPC) together with nanoparticle surface area monitor (NSAM) to achieve information about the interrelations of the outputs of the instruments. In addition, the ease of use of these instruments was evaluated. Differences between the results of different instruments can mainly be attributed to the nature of test particles. For spherical ammonium sulphate nanoparticles, the data from the instruments were in good agreement while larger differences were observed for particles with more complex morphology, the TiO2 agglomerates and powder. For instance, the FMPS showed a smaller particle size, a higher number concentration and a narrower size distribution compared with the SMPS for TiO2 particles. Thus, the type of the nanoparticle was observed to influence the data obtained from these different instruments. Therefore, care and expertise are essential when interpreting results from aerosol measurement instruments to estimate nanoparticle concentrations and properties.

  17. A rail system for circular synthetic aperture sonar imaging and acoustic target strength measurements: design/operation/preliminary results.

    Science.gov (United States)

    Kennedy, J L; Marston, T M; Lee, K; Lopes, J L; Lim, R

    2014-01-01

    A 22 m diameter circular rail, outfitted with a mobile sonar tower trolley, was designed, fabricated, instrumented with underwater acoustic transducers, and assembled on a 1.5 m thick sand layer at the bottom of a large freshwater pool to carry out sonar design and target scattering response studies. The mobile sonar tower translates along the rail via a drive motor controlled by customized LabVIEW software. The rail system is modular and assembly consists of separately deploying eight circular arc sections, measuring a nominal center radius of 11 m and 8.64 m arc length each, and having divers connect them together in the underwater environment. The system enables full scale measurements on targets of interest with 0.1° angular resolution over a complete 360° aperture, without disrupting target setup, and affording a level of control over target environment conditions and noise sources unachievable in standard field measurements. In recent use, the mobile cart carrying an instrumented sonar tower was translated along the rail in 720 equal position increments and acoustic backscatter data were acquired at each position. In addition, this system can accommodate both broadband monostatic and bistatic scattering measurements on targets of interest, allowing capture of target signature phenomena under diverse configurations to address current scientific and technical issues encountered in mine countermeasure and unexploded ordnance applications. In the work discussed here, the circular rail apparatus is used for acoustic backscatter testing, but this system also has the capacity to facilitate the acquisition of magnetic and optical sensor data from targets of interest. A brief description of the system design and operation will be presented along with preliminary processed results for data acquired from acoustic measurements conducted at the Naval Surface Warfare Center, Panama City Division Test Pond Facility. [Work Supported by the U.S. Office of Naval Research and

  18. Acoustic emission measurements in petroleum-related rock mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Unander, Tor Erling

    2002-07-01

    Acoustic emission activity in rock has usually been studied in crystalline rock, which reflects that rock mechanics has also mostly been occupied with such rocks in relations to seismology, mining and tunneling. On the other hand, petroleum-related rock mechanics focuses on the behaviour of sedimentary rock. Thus, this thesis presents a general study of acoustic emission activity in sedimentary rock, primarily in sandstone. Chalk, limestone and shale have also been tested, but to much less degree because the AE activity in these materials is low. To simplify the study, pore fluids have not been used. The advent of the personal computer and computerized measuring equipment have made possible new methods both for measuring and analysing acoustic emissions. Consequently, a majority of this work is devoted to the development and implementation of new analysis techniques. A broad range of topics are treated: (1) Quantification of the AE activity level, assuming that the event rate best represents the activity. An algorithm for estimating the event rate and a methodology for objectively describing special changes in the activity e.g., onset determination, are presented. (2) Analysis of AE waveform data. A new method for determining the source energy of an AE event is presented, and it is shown how seismic source theory can be used to analyze even intermediate quality data. Based on these techniques, it is shown that a major part of the measured AE activity originates from a region close to the sensor, not necessarily representing the entire sample. (3) An improved procedure for estimating source locations is presented. The main benefit is a procedure that better handles arrival time data with large errors. Statistical simulations are used to quantify the uncertainties in the locations. The analysis techniques are developed with the application to sedimentary rock in mind, and in two articles, the techniques are used in the study of such materials. The work in the first

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-01-01

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

  20. Optimizing a remote sensing instrument to measure atmospheric surface pressure

    Science.gov (United States)

    Peckham, G. E.; Gatley, C.; Flower, D. A.

    1983-01-01

    Atmospheric surface pressure can be remotely sensed from a satellite by an active instrument which measures return echoes from the ocean at frequencies near the 60 GHz oxygen absorption band. The instrument is optimized by selecting its frequencies of operation, transmitter powers and antenna size through a new procedure baesd on numerical simulation which maximizes the retrieval accuracy. The predicted standard deviation error in the retrieved surface pressure is 1 mb. In addition the measurements can be used to retrieve water vapor, cloud liquid water and sea state, which is related to wind speed.

  1. Measuring parent food practices: a systematic review of existing measures and examination of instruments

    OpenAIRE

    Vaughn, Amber E; Tabak, Rachel G.; Bryant, Maria J.; Ward, Dianne S

    2013-01-01

    During the last decade, there has been a rapid increase in development of instruments to measure parent food practices. Because these instruments often measure different constructs, or define common constructs differently, an evaluation of these instruments is needed. A systematic review of the literature was conducted to identify existing measures of parent food practices and to assess the quality of their development. The initial search used terms capturing home environment, parenting behav...

  2. Health Status Measurement Instruments in Chronic Obstructive Pulmonary Disease

    Directory of Open Access Journals (Sweden)

    Yves Lacasse

    1997-01-01

    Full Text Available Chronic obstructive pulmonary disease (COPD is associated with primary respiratory impairment, disability and handicap, as well as with secondary impairments not necessarily confined to the respiratory system. Because the primary goals of managing patients with COPD include relief of dyspnea and the improvement of health-related quality of life (HRQL, a direct measurement of HRQL is important. Fourteen disease-specific and nine generic questionnaires (four health profiles and five utility measures most commonly used to measure health status in patients with COPD were reviewed. The measures were classified according to their domain of interest, and their measurement properties - specifications, validity, reliability, responsiveness and interpretability - were described. This review suggests several findings. Currently used health status instruments usually refer to the patients’ perception of performance in three major domains of HRQL - somatic sensation, physical and occupational function, and psychological state. The choice of a questionnaire must be related to its purpose, with a clear distinction being made between its evaluative and discriminative function. In their evaluative function, only a few instruments fulfilled the criteria of responsiveness, and the interpretability of most questionnaires is limited. Generic questionnaires should not be used alone in clinical trials as evaluative instruments because of their inability to detect change over time. Further validation and improved interpretability of existing instruments would be of greater benefit to clinicians and scientists than the development of new questionnaires.

  3. D-Catch instrument : development and psychometric testing of a measurement instrument for nursing documentation in hospitals

    NARCIS (Netherlands)

    Paans, Wolter; Sermeus, Walter; Nieweg, Roos M. B.; van der Schans, Cees P.

    2010-01-01

    P>Title. D-Catch instrument: development and psychometric testing of a measurement instrument for nursing documentation in hospitals. Aim. This paper is a report of the development and testing of the psychometric properties of an instrument to measure the accuracy of nursing documentation in general

  4. Optimization of Acoustic Pressure Measurements for Impedance Eduction

    Science.gov (United States)

    Jones, M. G.; Watson, W. R.; Nark, D. M.

    2007-01-01

    As noise constraints become increasingly stringent, there is continued emphasis on the development of improved acoustic liner concepts to reduce the amount of fan noise radiated to communities surrounding airports. As a result, multiple analytical prediction tools and experimental rigs have been developed by industry and academia to support liner evaluation. NASA Langley has also placed considerable effort in this area over the last three decades. More recently, a finite element code (Q3D) based on a quasi-3D implementation of the convected Helmholtz equation has been combined with measured data acquired in the Langley Grazing Incidence Tube (GIT) to reduce liner impedance in the presence of grazing flow. A new Curved Duct Test Rig (CDTR) has also been developed to allow evaluation of liners in the presence of grazing flow and controlled, higher-order modes, with straight and curved waveguides. Upgraded versions of each of these two test rigs are expected to begin operation by early 2008. The Grazing Flow Impedance Tube (GFIT) will replace the GIT, and additional capabilities will be incorporated into the CDTR. The current investigation uses the Q3D finite element code to evaluate some of the key capabilities of these two test rigs. First, the Q3D code is used to evaluate the microphone distribution designed for the GFIT. Liners ranging in length from 51 to 610 mm are investigated to determine whether acceptable impedance eduction can be achieved with microphones placed on the wall opposite the liner. This analysis indicates the best results are achieved for liner lengths of at least 203 mm. Next, the effects of moving this GFIT microphone array to the wall adjacent to the liner are evaluated, and acceptable results are achieved if the microphones are placed off the centerline. Finally, the code is used to investigate potential microphone placements in the CDTR rigid wall adjacent to the wall containing an acoustic liner, to determine if sufficient fidelity can be

  5. PROGRESS OF ACOUSTIC WAVE TECHNIQUE AND ITS APPLICATION IN UNDERGROUND PRESSURE MEASUREMENT

    Institute of Scientific and Technical Information of China (English)

    周楚良; 李新元; 张晓龙

    1994-01-01

    This paper carries out the experiment study on the correlation between full stress-strain process of rock samples and the acoustic parameter change of rock by using the measurement system of KS acoustic wave data processing device. On the spot, the stability of surrounding rock is studied by means of experiments on the relationship between the change process (from elastic to plastic failure zone) in surrounding rock of roadway and the change law of acoustic parameters of rock. These acoustic parameters include wave amplitude, spectral amplitude, spectrum area, spectral density, wave velocity and attenuation coefficient etc.

  6. An assessment of the FlowCapt acoustic sensor for measuring snowdrift in the Indian Himalayas

    Indian Academy of Sciences (India)

    R K Das; P Datt; A Acharya

    2012-12-01

    Wind caused snow drifting plays a dominant role in the redistribution of snow mass that restructures a snowpack. Strong wind activity at the mountain tops results in uneven distribution of snow with erosion on windward side and deposition on leeward areas. Such snowdrift events are responsible for the formation of cornices, increase in the loading of avalanche release zones on the leeward side and consequent increase in the level of avalanche hazard. In this paper, we present the results of snowdrift measurement using an acoustic snow-drift meter, the FlowCapt, built by IAV Engineering, which was used during winter seasons of 2007–2010 at a field research station of Snow and Avalanche Study Establishment (SASE) in the western Himalayas. The aim of the study was to evaluate the suitability of the instrument in measuring snowdrift in the Himalayan weather conditions. Results proved the utility of the instrument as a useful tool to study drifting snow in remote areas. However, in the absence of conventional snow gauges for validation, the quality of the absolute snow flux data could not be ascertained.

  7. Research on the influence and correction method of depth scanning error to the underwater acoustic image measurement

    Institute of Scientific and Technical Information of China (English)

    MEI Jidan; ZHAI Chunpin; WANGYilin; HUI Junying

    2011-01-01

    The technology of underwater acoustic image measurement was a passive locating method with high precision in near field. To improve the precision of underwater acoustic image measurement, the influence of the depth scan error was analyzed and the correcti

  8. Use of an acoustic helium analyzer for measuring lung volumes.

    Science.gov (United States)

    Krumpe, P E; MacDannald, H J; Finley, T N; Schear, H E; Hall, J; Cribbs, D

    1981-01-01

    We have evaluated the use of an acoustic gas analyzer (AGA) for the measurement of total lung capacity (TLC) by single-breath helium dilution. The AGA has a rapid response time (0-90% response = 160 ms for 10% He), is linear for helium concentration of 0.1-10%, is stable over a wide range of ambient temperatures, and is small and portable. We plotted the output of the AGA vs. expired lung volume after a vital capacity breath of 10% He. However, since the AGA is sensitive to changes in speed of sound relative to air, the AGA output signal also reports an artifact due to alveolar gases. We corrected for this artifact by replotting a single-breath expiration after a vital capacity breath of room air. Mean alveolar helium concentration (HeA) was then measured by planimetry, using this alveolar gas curve as the base line. TLC was calculated using the HeA from the corrected AGA output and compared with TLC calculated from HeA simultaneously measured using a mass spectrometer (MS). In 12 normal subjects and 9 patients with chronic obstructive pulmonary disease (COPD) TLC-AGA and TLC-MS were compared by linear regression analysis; correlation coefficient (r) was 0.973 for normals and 0.968 for COPD patients (P less than 0.001). This single-breath; estimation of TLC using the corrected signal of the AGA vs. Expired volume seems ideally suited for the measurement of subdivisions of lung volume in field studies. PMID:7204187

  9. The Belt voice: Acoustical measurements and esthetic correlates

    Science.gov (United States)

    Bounous, Barry Urban

    This dissertation explores the esthetic attributes of the Belt voice through spectral acoustical analysis. The process of understanding the nature and safe practice of Belt is just beginning, whereas the understanding of classical singing is well established. The unique nature of the Belt sound provides difficulties for voice teachers attempting to evaluate the quality and appropriateness of a particular sound or performance. This study attempts to provide answers to the question "does Belt conform to a set of measurable esthetic standards?" In answering this question, this paper expands on a previous study of the esthetic attributes of the classical baritone voice (see "Vocal Beauty", NATS Journal 51,1) which also drew some tentative conclusions about the Belt voice but which had an inadequate sample pool of subjects from which to draw. Further, this study demonstrates that it is possible to scientifically investigate the realm of musical esthetics in the singing voice. It is possible to go beyond the "a trained voice compared to an untrained voice" paradigm when evaluating quantitative vocal parameters and actually investigate what truly beautiful voices do. There are functions of sound energy (measured in dB) transference which may affect the nervous system in predictable ways and which can be measured and associated with esthetics. This study does not show consistency in measurements for absolute beauty (taste) even among belt teachers and researchers but does show some markers with varying degrees of importance which may point to a difference between our cognitive learned response to singing and our emotional, more visceral response to sounds. The markers which are significant in determining vocal beauty are: (1) Vibrancy-Characteristics of vibrato including speed, width, and consistency (low variability). (2) Spectral makeup-Ratio of partial strength above the fundamental to the fundamental. (3) Activity of the voice-The quantity of energy being produced. (4

  10. Validation of an Instrument to Measure Community College Student Satisfaction

    Science.gov (United States)

    Zhai, Lijuan

    2012-01-01

    This article reports the development and validation of a survey instrument to measure community college students' satisfaction with their educational experiences. The initial survey included 95 questions addressing community college student experiences. Data were collected from 558 community college students during spring of 2001. An exploratory…

  11. Outcome instruments to measure frailty: a systematic review

    NARCIS (Netherlands)

    Vries, N.M. de; Staal, J.B.; Ravensberg, C.D. van; Hobbelen, J.S.; Olde Rikkert, M.G.M.; Nijhuis-Van der Sanden, M.W.G.

    2011-01-01

    Frailty is one of the greatest challenges for healthcare professionals. The level of frailty depends on several interrelated factors and can change over time while different interventions seem to be able to influence the level of frailty. Therefore, an outcome instrument to measure frailty with soun

  12. AZ State Profile. Arizona: Arizona's Instrument to Measure Standards (AIMS)

    Science.gov (United States)

    Center on Education Policy, 2010

    2010-01-01

    This paper provides information about the Arizona's Instrument to Measure Standards (AIMS). The purpose of the test is to determine prospective high school graduates' mastery of the state curriculum and to meet a state mandate. [For the main report, "State High School Tests: Exit Exams and Other Assessments", see ED514155.

  13. Towards a measurement instrument for determinants of innovations

    NARCIS (Netherlands)

    Fleuren, M.A.H.; Paulussen, T.G.W.M.; van Dommelen, P.; van Buuren, S.

    2014-01-01

    Objective. To develop a short instrument to measure determinants of innovations that may affect its implementation. Design. We pooled the original data from eight empirical studies of the implementation of evidence-based innovations. The studies used a list of 60 potentially relevant determinants ba

  14. Development of a nursing workload measurement instrument in burn care

    NARCIS (Netherlands)

    Jong, A.E.; Leeman, J.; Middelkoop, E.

    2009-01-01

    Existing workload measurement instruments fail to represent specific nursing activities in a setting where patients are characterized by a diversity of cause, location, extent and depth of burns, of age and of history. They also do not include educational levels and appropriate time standards. The a

  15. Acoustic measurements of F-15 aircraft operating in hush house, NSN 4920-02-070-2721

    Science.gov (United States)

    Miller, V. R.; Plzak, G. A.; Chinn, J. M.

    1981-09-01

    The purpose of this test program was to measure the acoustic environment in the hush house facility located at Kelly Air Force Base, Texas, during operation of the F-15 aircraft to ensure that aircraft structural acoustic design limits were not exceeded. The acoustic measurements showed that no potential sonic fatigue problems are anticipated with the F-15 aircraft structure during operation in the hush house. However, since these acoustic levels were increased over those measuring during run up on a concrete pad, it is recommended that F-15 equipment qualification levels be checked. The data indicated that the noise field within the hush house is diffuse and that the acoustical energy in the hangar area is radiated from the region between the engine exhaust and the hush house muffler front edge toward the forward part of the hangar.

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

    NARCIS (Netherlands)

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

    2013-01-01

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

  17. Acoustic resonances in HID lamps: model and measurement

    Energy Technology Data Exchange (ETDEWEB)

    Hirsch, John [Philips Lighting BV, Lightlabs, Mathildelaan 1, 5600 JM Eindhoven (Netherlands); Baumann, Bernd; Wolff, Marcus [Hamburg University of Applied Sciences, Institute for Physical Sensors, Berliner Tor 21, 20099 Hamburg (Germany); Bhosle, Sounil [Universite Paul Sabatier, Toulouse (France); Valdivia Barrientos, Ricardo, E-mail: john.hirsch@philips.co [National Nuclear Research Institute, Highway Mexico-Toluca s/n, La Marquesa, Ocoyoacac, CP 52750 (Mexico)

    2010-06-16

    A finite element model including plasma simulation is used to calculate the amplitude of acoustic resonances in HID lamps in a 2D axisymmetric geometry. Simulation results are presented for different operation parameters and are compared with experimental data.

  18. Comparative Analysis of Instruments Measuring Time Varying Harmonics

    Science.gov (United States)

    Belchior, Fernando Nunes; Ribeiro, Paulo Fernando; Carvalho, Frederico Marques

    2016-08-01

    This paper aims to evaluate the performance of commercial class A and class S power quality (PQ) instruments when measuring time-varying harmonics. By using a high precision programmable voltage and current source, two meters from different manufacturers are analyzed and compared. Three-phase voltage signals are applied to PQ instruments, considering 3 situations of time-varying harmonic distortions, whose harmonic distortion values are in accordance with typical values found in power systems. This work is relevant considering that international standardization documents do not pay much attention to this aspect of harmonic distortion.

  19. Hardness and elasticity of abrasive particles measured by instrumented indentation

    OpenAIRE

    Hvizdoš, P.

    2015-01-01

    Basic mechanical properties of seven types (from seven different sites) of abrasive garnet particles used for water jet cutting were measured using the technique of instrumented indentation (also called depth sensing indentation or nanoindentation). Hardness and modulus of elasticity were evaluated and compared. All the abrasives had similar measured mechanical properties (hardness 20 – 24.16 GPa), the highest values were found for the Czech garnet.

  20. Comparing alternative instruments to measure service quality in higher education

    OpenAIRE

    Ana Oliveira-Brochado; Rui Cunha Marques

    2007-01-01

    The purpose of this work is to examine the performance of five alternative measures of service quality in the high education sector – SERVQUAL (Service Quality), Importance-weighted SERVQUAL, SERVPERF (Service Performance), Importance-weighted SERVPERF and HedPERF (Higher Education Performance). We aim at determining which instrument has the superior measurement capability. Data were collected by means of a structured questionnaire containing perception items enhanced from the SERVPERF and HE...

  1. Long range acoustic measurements of an undersea volcano.

    Science.gov (United States)

    Heaney, Kevin D; Campbell, Richard L; Snellen, Mirjam

    2013-10-01

    A seamount 8 km southeast of Sarigan Island erupted on 29 May 2010 and was visually observed. The recordings on two sets of hydrophones, operated by International Monitoring System (IMS) of the Comprehensive Test Ban Treaty Organization (CTBTO) are analyzed. Each array is a triplet of axial single hydrophones deployed as a 2 km triangle. Measurements of acoustic intensity for the path to the southern triplet are on the order of 6 dB lower than those received on the northern triplet. Temporal cross-correlation beamforming estimation is performed and the estimated arrival angles for the two arrays, 265° and 267° were consistent with the predicted geodesic arrival of 264.6° and 267.8°, respectively. Cross-correlation between single phones on the northern and southern arrays reveals a peak at 266°, with a cross-correlation of 0.1. Nx2D parabolic equation modeling predicts complete blockage due to seamount interaction along the geodesic path. Overprediction of the seamount blockage indicates that the 2D approximation is incorrect, and three-dimensional propagation must be used to explain the observations. This is demonstrated by the computation of the Adiabatic Mode Parabolic Equation Transmission Loss, which predicts a 5-10 dB lower reception at the southern site. PMID:24116524

  2. Effects of Various Architectural Parameters on Six Room Acoustical Measures in Auditoria.

    Science.gov (United States)

    Chiang, Wei-Hwa

    The effects of architectural parameters on six room acoustical measures were investigated by means of correlation analyses, factor analyses and multiple regression analyses based on data taken in twenty halls. Architectural parameters were used to estimate acoustical measures taken at individual locations within each room as well as the averages and standard deviations of all measured values in the rooms. The six acoustical measures were Early Decay Time (EDT10), Clarity Index (C80), Overall Level (G), Bass Ratio based on Early Decay Time (BR(EDT)), Treble Ratio based on Early Decay Time (TR(EDT)), and Early Inter-aural Cross Correlation (IACC80). A comprehensive method of quantifying various architectural characteristics of rooms was developed to define a large number of architectural parameters that were hypothesized to effect the acoustical measurements made in the rooms. This study quantitatively confirmed many of the principles used in the design of concert halls and auditoria. Three groups of room architectural parameters such as the parameters associated with the depth of diffusing surfaces were significantly correlated with the hall standard deviations of most of the acoustical measures. Significant differences of statistical relations among architectural parameters and receiver specific acoustical measures were found between a group of music halls and a group of lecture halls. For example, architectural parameters such as the relative distance from the receiver to the overhead ceiling increased the percentage of the variance of acoustical measures that was explained by Barron's revised theory from approximately 70% to 80% only when data were taken in the group of music halls. This study revealed the major architectural parameters which have strong relations with individual acoustical measures forming the basis for a more quantitative method for advancing the theoretical design of concert halls and other auditoria. The results of this study provide

  3. Satisfaction measurement instruments for healthcare service users: a systematic review.

    Science.gov (United States)

    Almeida, Renato Santos de; Bourliataux-Lajoinie, Stephane; Martins, Mônica

    2015-01-01

    Patient satisfaction surveys can be an interesting way to improve quality and discuss the concept of patient-centered care. This study aimed to conduct a systematic review of the validated patient satisfaction measurement instruments applied in healthcare. The systematic review searched the MEDLINE/PubMed, LILACS, SciELO, Scopus and Web of Knowledge. The search strategy used the terms: "Patient Satisfaction" AND "Patient centered care" AND "Healthcare survey OR Satisfaction questionnaire" AND "Psychometric properties". 37 studies were included and almost all studies showed that satisfaction is a multidimensional construct. In these studies, 34 different instruments were used and most surveys contained the dimension patient-healthcare professional interactions, physical environment and management process. The COSMIN score for methodological quality showed that most of them scored a good or fair average. We can conclude that there is not a gold standard instrument for patient satisfaction assessment but some dimensions are essential for this construct. PMID:25715288

  4. Satisfaction measurement instruments for healthcare service users: a systematic review

    Directory of Open Access Journals (Sweden)

    Renato Santos de Almeida

    2015-01-01

    Full Text Available Patient satisfaction surveys can be an interesting way to improve quality and discuss the concept of patient-centered care. This study aimed to conduct a systematic review of the validated patient satisfaction measurement instruments applied in healthcare. The systematic review searched the MEDLINE/PubMed, LILACS, SciELO, Scopus and Web of Knowledge. The search strategy used the terms: "Patient Satisfaction" AND "Patient centered care" AND "Healthcare survey OR Satisfaction questionnaire" AND "Psychometric properties". 37 studies were included and almost all studies showed that satisfaction is a multidimensional construct. In these studies, 34 different instruments were used and most surveys contained the dimension patient-healthcare professional interactions, physical environment and management process. The COSMIN score for methodological quality showed that most of them scored a good or fair average. We can conclude that there is not a gold standard instrument for patient satisfaction assessment but some dimensions are essential for this construct.

  5. Power Quality Monitoring and Power Measurements by Using Virtual Instrumentation

    Directory of Open Access Journals (Sweden)

    Z. Kokolanski

    2009-06-01

    Full Text Available The presented paper describes a virtual instrument used for monitoring and analysis of the relevant power quality parameters and power measurements.The metrological support block is realized in LabVIEW environment which uses advanced methods for measurement and recording of the power quality parameters in accordance with the European quality standards. In that way, a suitable hardware solution for signal conditioning and load control is proposed. The most important parameters (voltage, current, power are recorded into text files which are further used for measurement data analyses. The measurement results are obtained by using waveform simulator METREL.

  6. Smartphone measurement engineering - Innovative challenges for science & education, instrumentation & training

    Science.gov (United States)

    Hofmann, D.; Dittrich, P.-G.; Duentsch, E.

    2010-07-01

    Smartphones have an enormous conceptual and structural influence on measurement science & education, instrumentation & training. Smartphones are matured. They became convenient, reliable and affordable. In 2009 worldwide 174 million Smartphones has been delivered. Measurement with Smartphones is ready for the future. In only 10 years the German vision industry tripled its global sales volume to one Billion Euro/Year. Machine vision is used for mobile object identification, contactless industrial quality control, personalized health care, remote facility and transport management, safety critical surveillance and all tasks which are too complex for the human eye or too monotonous for the human brain. Aim of the paper is to describe selected success stories for the application of Smartphones for measurement engineering in science and education, instrumentation and training.

  7. Thickness measurement of Ni thin film using dispersion characteristics of a surface acoustic wave

    International Nuclear Information System (INIS)

    In this study, we suggest a method to measure the thickness of thin films nondestructively using the dispersion characteristics of a surface acoustic wave propagating along the thin film surface. To measure the thickness of thin films, we deposited thin films with different thicknesses on a Si (100) wafer substrate by controlling the deposit time using the E-beam evaporation method. The thickness of the thin films was measured using a scanning electron microscope. Subsequently, the surface wave velocity of the thin films with different thicknesses was measured using the V(z) curve method of scanning acoustic microscopy. The correlation between the measured thickness and surface acoustic wave velocity was verified. The wave velocity of the film decreased as the film thickness increased. Therefore, thin film thickness can be determined by measuring the dispersion characteristics of the surface acoustic wave velocity.

  8. Application of an acoustic noise removal method to aircraft-based atmospheric temperature measurements

    Science.gov (United States)

    Hugo, Ronald J.; Nowlin, Scott R.; Hahn, Ila L.; Eaton, Frank D.; McCrae, Kim A.

    2003-01-01

    An acoustic noise removal method is used to reject engine acoustical disturbances from aircraft-based atmospheric temperature measurements. Removal of engine noise from atmospheric temperature measurements allows a larger wave number range to be fit while quantifying the magnitude of atmospheric temperature turbulence. The larger wave number range was found to result in a more statistically certain spectral slope estimate, with up to a 50% reduction in the standard deviation of measured spectral slopes. The noise removal technique was found to break down under conditions of weak atmospheric temperature turbulence where the engine acoustical disturbance can be several orders of magnitude larger than atmospheric temperature turbulence.

  9. Measuring Turbulence from Moored Acoustic Doppler Velocimeters. A Manual to Quantifying Inflow at Tidal Energy Sites

    Energy Technology Data Exchange (ETDEWEB)

    Kilcher, Levi [National Renewable Energy Lab. (NREL), Golden, CO (United States); Thomson, Jim [Univ. of Washington, Seattle, WA (United States); Talbert, Joe [Univ. of Washington, Seattle, WA (United States); DeKlerk, Alex [Univ. of Washington, Seattle, WA (United States)

    2016-03-01

    This work details a methodology for measuring hub height inflow turbulence using moored acoustic Doppler velocimiters (ADVs). This approach is motivated by the shortcomings of alternatives. For example, remote velocity measurements (i.e., from acoustic Doppler profilers) lack sufficient precision for device simulation, and rigid tower-mounted measurements are very expensive and technically challenging in the tidal environment. Moorings offer a low-cost, site-adaptable and robust deployment platform, and ADVs provide the necessary precision to accurately quantify turbulence.

  10. Acoustical measurements of expression devices in pipe organs.

    Science.gov (United States)

    Braasch, Jonas

    2008-03-01

    In this investigation, three different swell systems known in pipe organs, the swell box, the crescendo wheel, and the historic wind swell were measured and compared to each other. The dynamic range of the crescendo wheel was found to be most effective, and for frequencies near 2 kHz the increase in sound pressure level could be up to 50 dB between the softest and the loudest adjustment. The maximum dynamic range for the wind swell and the swell box were found to be 10-20 dB in the same frequency range. With its step-wise crescendo procedure, the crescendo wheel simulates the type of orchestra crescendo which is reached by successively adding further musical instruments. In contrast, the swell box and the wind swell produce a crescendo effect similar to the crescendo in which individual musical instruments perform a dynamic movement. This type of crescendo requires a continuous level increase but allows a smaller dynamic range. The disappearance of the wind swell is not surprising because it offers no advantage over the swell box, while being restricted to stops with free reeds.

  11. Measurements with the new PHE neutron survey instrument

    International Nuclear Information System (INIS)

    A novel design of survey instrument has been developed to accurately estimate ambient dose equivalent from neutrons with energies in the range from thermal to 20 MeV. The device features moderating and attenuating layers to ease measurement of fast and intermediate energy neutrons, combined with guides that channel low-energy neutrons to the single, central detector. A prototype of this device has been constructed and exposed to a set of calibration fields: the resulting measured responses are presented and discussed here, and compared against Monte Carlo data. A simple simulated workplace neutron field has also been developed to test the device. Measured response data have been determined for a prototype design of neutron survey instrument, using facilities at PHE and NPL. In general, the results demonstrated good directional invariance and agreed well with data obtained by Monte Carlo modelling, raising confidence in the accuracy of the response characteristics expected for the device. A simple simulated workplace field has also been developed and characterised, and the performance of the device assessed in it: agreement between measured and modelled results suggests that the device would behave as anticipated in real workplace fields. These performances will be investigated further in the future, as the design makes the transition from a research prototype to a commercially available instrument. (authors)

  12. Virtual Instrument for Emissions Measurement of Internal Combustion Engines

    Directory of Open Access Journals (Sweden)

    Armando Pérez

    2016-01-01

    Full Text Available The gases emissions measurement systems in internal combustion engines are strict and expensive nowadays. For this reason, a virtual instrument was developed to measure the combustion emissions from an internal combustion diesel engine, running with diesel-biodiesel mixtures. This software is called virtual instrument for emissions measurement (VIEM, and it was developed in the platform of LabVIEW 2010® virtual programming. VIEM works with sensors connected to a signal conditioning system, and a data acquisition system is used as interface for a computer in order to measure and monitor in real time the emissions of O2, NO, CO, SO2, and CO2 gases. This paper shows the results of the VIEM programming, the integrated circuits diagrams used for the signal conditioning of sensors, and the sensors characterization of O2, NO, CO, SO2, and CO2. VIEM is a low-cost instrument and is simple and easy to use. Besides, it is scalable, making it flexible and defined by the user.

  13. Virtual Instrument for Emissions Measurement of Internal Combustion Engines.

    Science.gov (United States)

    Pérez, Armando; Ramos, Rogelio; Montero, Gisela; Coronado, Marcos; García, Conrado; Pérez, Rubén

    2016-01-01

    The gases emissions measurement systems in internal combustion engines are strict and expensive nowadays. For this reason, a virtual instrument was developed to measure the combustion emissions from an internal combustion diesel engine, running with diesel-biodiesel mixtures. This software is called virtual instrument for emissions measurement (VIEM), and it was developed in the platform of LabVIEW 2010® virtual programming. VIEM works with sensors connected to a signal conditioning system, and a data acquisition system is used as interface for a computer in order to measure and monitor in real time the emissions of O2, NO, CO, SO2, and CO2 gases. This paper shows the results of the VIEM programming, the integrated circuits diagrams used for the signal conditioning of sensors, and the sensors characterization of O2, NO, CO, SO2, and CO2. VIEM is a low-cost instrument and is simple and easy to use. Besides, it is scalable, making it flexible and defined by the user. PMID:27034893

  14. Collaboration between TAEA and ANASA for developing radiation measurement instruments

    International Nuclear Information System (INIS)

    Full text: Collaboration between TAEA and ANASA on the subject of 'Developing Radiation Measurement Instruments' has started by the organization of TAEA-TUDNAEM in 2002. Firstly the model NEB.300 'Dose-Rate Meter' equipped with external scintillation probe was designed and a prototype produced. Scintillation Probe of the instrument is produced by ANASA personnel, the electronics measurement circuits and other units are developed by TAEA personnel. The NEB.300 Dose-Rate Meter is a radiation meter designed to measure especially very low radiation with external scintillation probe. It has wide application range, because of its warning specification for protecting personnel working with radiation sources, and because of its measuring and monitoring specifications for surveying, evaluating and carrying the radioactive materials. Advanced micro controller technology is used to cover problems of radiation measurement. Control by micro controller enables reliable, stable measurement and display of low level dose rate fields. It makes possible the simultaneous measurement of both dose and dose rate values with scintillation detector sensitive to gamma and X-rays. Set to different dose rate or dose levels it warns audibly. Measurements are shown on the 2 1/2 digits auto range display besides other warnings

  15. Measurements Verifying the Optics of the Electron Drift Instrument

    Science.gov (United States)

    Kooi, Vanessa; Kletzing, Craig; Bounds, Scott; Sigsbee, Kristine M.

    2015-04-01

    Magnetic reconnection is the process of breaking and reconnecting of opposing magnetic field lines, and is often associated with tremendous energy transfer. The energy transferred by reconnection directly affects people through its influence on geospace weather and technological systems - such as telecommunication networks, GPS, and power grids. However, the mechanisms that cause magnetic reconnection are not well understood. The Magnetospheric Multi-Scale Mission (MMS) will use four spacecraft in a pyramid formation to make three-dimensional measurements of the structures in magnetic reconnection occurring in the Earth's magnetosphere.The spacecraft will repeatedly sample these regions for a prolonged period of time to gather data in more detail than has been previously possible. MMS is scheduled to be launched in March of 2015. The Electron Drift Instrument (EDI) will be used on MMS to measure the electric fields associated with magnetic reconnection. The EDI is a device used on spacecraft to measure electric fields by emitting an electron beam and measuring the E x B drift of the returning electrons after one gyration. This paper concentrates on measurements of the EDI’s optics system. The testing process includes measuring the optics response to a uni-directional electron beam. These measurements are used to verify the response of the EDI's optics and to allow for the optimization of the desired optics state. The measurements agree well with simulations and we are confident in the performance of the EDI instrument.

  16. The influence of thoron on instruments measuring radon activity concentration.

    Science.gov (United States)

    Michielsen, N; Bondiguel, S

    2015-11-01

    Thoron, the isotope 220 of radon, is a radionuclide whose concentration may influence the measurement of the activity concentration of (222)Rn in the air. If in the case of continuous and active sampling measuring instruments, using a pump for example, the influence of thoron on radon measurement is obvious and is taken into account in the apparatus, it is often assumed that in the case of a passive sampling, by diffusion through a filter for example, this thoron influence is negligible. This is due to the very short radioactive half-life of thoron, 55.6 s (3.82 d for (222)Rn), and the assumption that the diffusion time of thoron in the detection chamber is long enough beside that of the thoron half-life. The objective of this study is to check whether this assumption is true or not for different kinds of commercial electronic apparatus used to measure radon activity concentration from soil to dwellings. First of all, the devices were calibrated in activity concentration of radon, and then they were exposed to a controlled thoron atmosphere. The experiments concerning the thoron aimed to investigate the sensitivity to thoron in the radon measuring mode of the apparatus. Results of these experiments show that all devices have a very quick answer to thoron atmosphere, even though the sensitivities vary from one instrument to another. Results clearly show that this influence on radon measurement due to the thoron is observed also after the exposition because of the decay of (212)Pb and its progenies. In conclusion, the sensitivity to thoron in the radon measuring mode depends strongly on the type of instruments. The results of the present investigation show that for some apparatus, the influence of thoron cannot be disregarded especially when measuring radon in soil.

  17. Measuring baryon acoustic oscillations from the clustering of voids

    Science.gov (United States)

    Liang, Yu; Zhao, Cheng; Chuang, Chia-Hsun; Kitaura, Francisco-Shu; Tao, Charling

    2016-07-01

    We investigate the necessary methodology to optimally measure the baryon acoustic oscillation (BAO) signal from voids, based on galaxy redshift catalogues. To this end, we study the dependence of the BAO signal on the population of voids classified by their sizes. We find for the first time the characteristic features of the correlation function of voids including the first robust detection of BAOs in mock galaxy catalogues. These show an anti-correlation around the scale corresponding to the smallest size of voids in the sample (the void exclusion effect), and dips at both sides of the BAO peak, which can be used to determine the significance of the BAO signal without any priori model. Furthermore, our analysis demonstrates that there is a scale-dependent bias for different populations of voids depending on the radius, with the peculiar property that the void population with the largest BAO significance corresponds to tracers with approximately zero bias on the largest scales. We further investigate the methodology on an additional set of 1000 realistic mock galaxy catalogues reproducing the SDSS-III/BOSS CMASS DR11 data, to control the impact of sky mask and radial selection function. Our solution is based on generating voids from randoms including the same survey geometry and completeness, and a post-processing cleaning procedure in the holes and at the boundaries of the survey. The methodology and optimal selection of void populations validated in this work have been used to perform the first BAO detection from voids in observations, presented in a companion paper.

  18. Measurement and Calibration of Centrifugal Compressor Pressure Scanning Instrumentation

    OpenAIRE

    Rivas, Jose R; Lou, Fangyuan; Harrison, Herbert "Trey"; Key, Nicole

    2015-01-01

    The compressor is a key component of a jet engine necessary to compress air for the combustion process. Research to optimize compressor efficiency through the understanding of air flow behavior has led to increased efforts in creating modern compressor test facilities. In collaboration with Honeywell, the High Speed Compressor facility at Zucrow Laboratories has built a centrifugal compressor test cell with instrumentation to measure the temperatures and pressures of the air flow. This facili...

  19. Spectral measurements of PMCs from SBUV/2 instruments

    Science.gov (United States)

    Deland, Matthew T.; Shettle, Eric P.; Thomas, Gary E.; Olivero, John J.

    2006-01-01

    The SBUV/2 (Solar Backscattered Ultraviolet, model 2) instrument is designed to monitor ozone stratospheric profile and total column ozone using measurements of the Earth's backscattered ultraviolet albedo. We have previously demonstrated that the normal radiance measurements from SBUV/2 instruments, which sample 12 discrete wavelengths between 252 and 340 nm during each scan, can be used to identify polar mesospheric clouds (PMCs). Some SBUV/2 instruments also periodically view the earth in continuous scan mode, covering the wavelength range 160 400 nm with 0.15 nm sampling. Analysis of these data show PMC occurrence rates similar to the normal discrete scan results, although the observation technique reduces the number of daily measurements by a factor of six. PMC observed by SBUV/2 instruments show a monotonic variation in the residual spectral albedo over the wavelength range 250 300 nm, with maximum enhancements of 10 15% at 250 nm. This result is consistent with microphysical model predictions from Jensen [1989.A numerical model of polar mesospheric cloud formation and evolution, Ph. D. Thesis, University of Colorado]. We find no evidence for a systematic localized increase in PMC residual albedo for wavelengths near 260 nm, in contrast to the recently reported results from the MSX UVISI instrument [Carbary J.F., et al., 2004. Evidence for bimodal particle distribution from the spectra of polar mesospheric clouds. Geophysics Research. Letters 31, L13108]. This result is observed for three different SBUV/2 instruments in both Northern and Southern Hemisphere data over a 13-year span. Our Mie scattering calculations show that the location and magnitude of the 260 nm “hump” feature is dependent upon the specific scattering angles appropriate to the MSX measurements. Although it explains the MSX spectrum, the bimodal size distribution proposed by Carbary et al. (2004), cannot explain the lack of scattering angle dependence of the SBUV/2 spectral shapes. The

  20. 30 CFR 75.1719-3 - Methods of measurement; light measuring instruments.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Methods of measurement; light measuring... § 75.1719-3 Methods of measurement; light measuring instruments. (a) Compliance with § 75.1719-1(d... intensity measurements may be made at any time longwall or shortwall mining equipment is operated...

  1. a Study of the Acoustical Termination on Practical Gas Pulsation Measurement

    Science.gov (United States)

    LAI, P. C.-C.

    2000-06-01

    It has been well recognized in the past that an anechoic termination, which can effectively eliminate the reflective acoustic wave, is required for measurement of exhaust gas pulsation from engines or machinery. In academic environment, the acoustic termination on the exhaust line can be well controlled by appropriate treatment. However, it is not unusual in practical industrial applications that the anechoic termination is not available. Therefore, a theoretical investigation was performed in order to understand the impact on the gas pulsation measurement without an anechoic termination. A simplified model of an exhaust line with different acoustic terminations was analyzed by both analytical and experimental approaches. Both one-microphone and two-microphone measurement methods, which are commonly used, were evaluated. The results clearly demonstrate that without an anechoic termination, the variations of the measurements will be substantial due to the reflective acoustic wave, as has been argued for years in the industry.

  2. Momentum Flux Measuring Instrument for Neutral and Charged Particle Flows

    Science.gov (United States)

    Chavers, Greg; Chang-Diaz, Franklin; Schafer, Charles F. (Technical Monitor)

    2002-01-01

    An instrument to measure the momentum flux (total pressure) of plasma and neutral particle jets onto a surface has been developed. While this instrument was developed for magnetized plasmas, the concept works for non-magnetized plasmas as well. We have measured forces as small as 10(exp -4) Newtons on a surface immersed in the plasma where small forces are due to ionic and neutral particles with kinetic energies on the order of a few eV impacting the surface. This instrument, a force sensor, uses a target plate (surface) that is immersed in the plasma and connected to one end of an alumina rod while the opposite end of the alumina rod is mechanically connected to a titanium beam on which four strain gauges are mounted. The force on the target generates torque causing strain in the beam. The resulting strain measurements can be correlated to a force on the target plate. The alumina rod electrically and thermally isolates the target plate from the strain gauge beam and allows the strain gauges to be located out of the plasma flow while also serving as a moment arm of several inches to increase the strain in the beam at the strain gauge location. These force measurements correspond directly to momentum flux and may be used with known plasma conditions to place boundaries on the kinetic energies of the plasma and neutral particles. The force measurements may also be used to infer thrust produced by a plasma propulsive device. Stainless steel, titanium, molybdenum, and aluminum flat target plates have been used. Momentum flux measurements of H2, D2, He, and Ar plasmas produced in a magnetized plasma device have been performed.

  3. Underwater hybrid near-field acoustical holography based on the measurement of vector hydrophone array

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Hybrid near-field acoustical holography(NAH) is developed for reconstructing acoustic radiation from a cylindrical source in a complex underwater environment. In hybrid NAH,we combine statistically optimized near-field acoustical holography(SONAH) and broadband acoustical holography from intensity measurements(BAHIM) to reconstruct the underwater cylindrical source field. First,the BAHIM is utilized to regenerate as much acoustic pressures on the hologram surface as necessary,and then the acoustic pressures are taken as input to the formulation implemented numerically by SONAH. The main advantages of this technology are that the complex pressure on the hologram surface can be reconstructed without reference signal,and the measurement array can be smaller than the source,thus the practicability and efficiency of this technology are greatly enhanced. Numerical examples of a cylindrical source are demonstrated. Test results show that hybrid NAH can yield a more accurate reconstruction than conventional NAH. Then,an experiment has been carried out with a vector hydrophone array. The experimental results show the advantage of hybrid NAH in the reconstruction of an acoustic field and the feasibility of using a vector hydrophone array in an underwater NAH measurement,as well as the identification and localization of noise sources.

  4. Coherent Laser Instrument Would Measure Range and Velocity

    Science.gov (United States)

    Chang, Daniel; Cardell, Greg; San Martin, Alejandro; Spiers, Gary

    2005-01-01

    A proposed instrument would project a narrow laser beam that would be frequency-modulated with a pseudorandom noise (PN) code for simultaneous measurement of range and velocity along the beam. The instrument performs these functions in a low mass, power, and volume package using a novel combination of established techniques. Originally intended as a low resource- footprint guidance sensor for descent and landing of small spacecraft onto Mars or small bodies (e.g., asteroids), the basic instrument concept also lends itself well to a similar application guiding aircraft (especially, small unmanned aircraft), and to such other applications as ranging of topographical features and measuring velocities of airborne light-scattering particles as wind indicators. Several key features of the instrument s design contribute to its favorable performance and resource-consumption characteristics. A laser beam is intrinsically much narrower (for the same exit aperture telescope or antenna) than a radar beam, eliminating the need to correct for the effect of sloping terrain over the beam width, as is the case with radar. Furthermore, the use of continuous-wave (CW), erbium-doped fiber lasers with excellent spectral purity (narrow line width) permits greater velocity resolution, while reducing the laser s power requirement compared to a more typical pulsed solid-state laser. The use of CW also takes proper advantage of the increased sensitivity of coherent detection, necessary in the first place for direct measurement of velocity using the Doppler effect. However, measuring range with a CW beam requires modulation to "tag" portions of it for time-of-flight determination; typically, the modulation consists of a PN code. A novel element of the instrument s design is the use of frequency modulation (FM) to accomplish both the PN-modulation and the Doppler-bias frequency shift necessary for signed velocity measurements. This permits the use of a single low-power waveguide electrooptic

  5. Measurements and Simulation Studies of Piezoceramics for Acoustic Particle Detection

    CERN Document Server

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

    2005-01-01

    Calibration sources are an indispensable tool for all detectors. In acoustic particle detection the goal of a calibration source is to mimic neutrino signatures as expected from hadronic cascades. A simple and promising method for the emulation of neutrino signals are piezo ceramics. We will present results of measruements and simulations on these piezo ceramics.

  6. Simple discrimination method between False Acoustic Emission and Acoustic Emission revealed by piezoelectric sensors, in Gran Sasso mountain measurements (L)

    Science.gov (United States)

    Diodati, Paolo; Piazza, Stefano

    2004-07-01

    Recently it was shown, studying data acquired with in-situ measurements on the Gran Sasso mountain (Italy), for about ten years, by means of a high sensitivity transducer coupled to the free-end section of a stainless steel rod fixed by cement in a rock-drill hole 10 m high, about 2500 m above sea level, that Acoustic Emission (AE) can be affected by more than 90% False Acoustic Emission (FAE) of an electromagnetic origin. A very simple method to solve the problem of the discrimination between AE events due to elastic waves, from FAE signals, due to electromagnetic noise, both coming from the same ``reception-point,'' is presented. The reliability of the obtained separation is confirmed also by the reported amplitude and time distribution of AE events, typical of fracture dynamics and those of FAE events, similar to those of noise.

  7. Subjective evaluation of a concert hall's acoustics using a free-format-type questionnaire and comparison with objective measurements

    Science.gov (United States)

    Okano, Toshiyuki; Beranek, Leo L.

    2002-11-01

    A free-format type of audiences' judgment of the acoustical properties of a hall and music critics' writings were used as the basis for this study. These subjective responses are related to the Dai-Ichi Seimei Hall in Tokyo. This hall is an oval-shaped, one-balcony space, seating 767 persons. Its primary use is for various types of chamber music and solo-instrument performances. Eight acoustical attributes were investigated, ''reverberation,'' ''clarity,'' ''loudness,'' ''intimacy,'' ''spaciousness,'' ''balance,'' ''localization,'' and ''timbre,'' plus ''general impression.'' Subjective comments about these attributes were obtained. Objective measurements were made in the hall and are compared with those made in several similar-sized halls of two shapes. In the rear seats of two oval-shaped halls the strength factor GE (determined in the first 80 ms of the impulse response) was greater than the GE found in the rear seats of similar-sized rectangular halls. The subjective results and the objective measurements were closely correlated, especially for reverberation, clarity, and warmth (a subcomponent of timbre). It was suggested that the greater strength GE in the rear seats made the hall seem smaller and thus more intimate. The subjective comments also confirmed the hall's wide applicability, indicating that the acoustical characteristics used for its design were well chosen.

  8. A compact DOAS instrument optimised for ammonia field-measurements

    Science.gov (United States)

    Neftel, Albrecht; Sintermann, Joerg; Dietrich, Klaus; Häni, Christoph; Jocher, Markus

    2016-04-01

    Accurate, high time-resolution measurements of NH3 in ambient air are still a challenge due to the stickiness of this molecule and its interactions with inlet or instrument surfaces. Differential optical absorption spectroscopy (DOAS) with open-path arrangement offers a contact-free in-situ approach to determine ambient NH3. We present a DOAS instrument, optimised for open-path field-measurements of ambient ammonia (NH3) alongside nitrogen oxide (NO) and sulphur dioxide (SO2). This device, operating in the UV range over paths of up to 100 m, is a further development of the miniDOAS presented by Volten et al. (2012). We use a temperature-controlled spectrometer, a deuterium light source and a modified optical arrangement. The system was set up in a robust, field-deployable, temperature-regulated housing. For the evaluation of light spectra a new high-pass filter routine based upon robust baseline extraction with local regression was used. In order to fit differential absorption cross-sections to the measurements, multiple linear regression is performed including terms of an autoregressive-moving-average model. In this presentation we discuss the influence of filter and fit procedure on the precision and accuracy of the system with examples of field measurements with artificial NH3 sources. Volten, H., Bergwerff, J. B., Haaima, M., Lolkema, D. E., Berkhout, A. J. C., van der Hoff, G. R., Potma, C. J. M., Wichink Kruit, R. J., van Pul, W. A. J. and Swart, D. P. J.: Two instruments based on differential optical absorption spectroscopy (DOAS) to measure accurate ammonia concentrations in the atmosphere, Atmospheric Meas. Tech., 5(2), 413-427, doi:10.5194/amt-5-413-2012, 2012.

  9. A Monte-Carlo investigation of the uncertainty of acoustic decay measurements

    DEFF Research Database (Denmark)

    Cabo, David Pérez; Seoane, Manuel A. Sobreira; Jacobsen, Finn

    2012-01-01

    Measurement of acoustic decays can be problematic at low frequencies: short decays cannot be evaluated accurately. Several effects influencing the evaluation will be reviewed in this paper. As new contribution, the measurement uncertainty due to one-third octave band pass filters will be analysed...... been be set up: the model function is a model of the acoustic decays, where the modal density, the resonances of the system, and the amplitude and phase of the normal modes may be considered as random variables. Once the random input variables and the model function are defined, the uncertainty...... of acoustic decay measurements can be estimated. Different filters will be analysed: linear phase FIR and IIR filters both in their direct and time-reversed versions. © European Acoustics Association....

  10. LHC Beam Instrumentation: Beam Profile Measurements (2/3)

    CERN Document Server

    CERN. Geneva

    2014-01-01

    The LHC is equipped with a full suite of sophisticated beam instrumentation which has been essential for rapid commissioning, the safe increase in total stored beam power and the understanding of machine optics and accelerator physics phenomena. These lectures will introduce these systems and comment on their contributions to the various stages of beam operation. They will include details on: the beam position system and its use for real-time global orbit feedback; the beam loss system and its role in machine protection; total and bunch by bunch intensity measurements; tune measurement and feedback; diagnostics for transverse beam size measurements, abort gap monitoring and longitudinal density measurements. Issues and problems encountered along the way will also be discussed together with the prospect for future upgrades.

  11. The COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN and how to select an outcome measurement instrument

    Directory of Open Access Journals (Sweden)

    Lidwine B. Mokkink

    2016-01-01

    Full Text Available Background: COSMIN (COnsensus-based Standards for the selection of health Measurement INstruments is an initiative of an international multidisciplinary team of researchers who aim to improve the selection of outcome measurement instruments both in research and in clinical practice by developing tools for selecting the most appropriate available instrument. Method: In this paper these tools are described, i.e. the COSMIN taxonomy and definition of measurement properties; the COSMIN checklist to evaluate the methodological quality of studies on measurement properties; a search filter for finding studies on measurement properties; a protocol for systematic reviews of outcome measurement instruments; a database of systematic reviews of outcome measurement instruments; and a guideline for selecting outcome measurement instruments for Core Outcome Sets in clinical trials. Currently, we are updating the COSMIN checklist, particularly the standards for content validity studies. Also new standards for studies using Item Response Theory methods will be developed. Additionally, in the future we want to develop standards for studies on the quality of non-patient reported outcome measures, such as clinician-reported outcomes and performance-based outcomes. Conclusions: In summary, we plea for more standardization in the use of outcome measurement instruments, for conducting high quality systematic reviews on measurement instruments in which the best available outcome measurement instrument is recommended, and for stopping the use of poor outcome measurement instruments.

  12. On Mass Loading and Dissipation Measured with Acoustic Wave Sensors: A Review

    Directory of Open Access Journals (Sweden)

    Marina V. Voinova

    2009-01-01

    Full Text Available We summarize current trends in the analysis of physical properties (surface mass density, viscosity, elasticity, friction, and charge of various thin films measured with a solid-state sensor oscillating in a gaseous or liquid environment. We cover three different types of mechanically oscillating sensors: the quartz crystal microbalance with dissipation (QCM-D monitoring, surface acoustic wave (SAW, resonators and magnetoelastic sensors (MESs. The fourth class of novel acoustic wave (AW mass sensors, namely thin-film bulk acoustic resonators (TFBARs on vibrating membranes is discussed in brief. The paper contains a survey of theoretical results and practical applications of the sensors and includes a comprehensive bibliography.

  13. Atmospheric Radiation Measurement Climate Research Facility (ACRF Instrumentation Status: New, Current, and Future)

    Energy Technology Data Exchange (ETDEWEB)

    JW Voyles

    2008-01-30

    The purpose of this report is to provide a concise but comprehensive overview of Atmospheric Radiation Measurement Climate Research Facility instrumentation status. The report is divided into the following four sections: (1) new instrumentation in the process of being acquired and deployed, (2) existing instrumentation and progress on improvements or upgrades, (3) proposed future instrumentation, and (4) Small Business Innovation Research instrument development.

  14. Towards Measuring Continuous Acoustic Feature Convergence in Unconstrained Spoken Dialogues

    OpenAIRE

    Kousidis, Spyros; Dorran, David; Wang, Yi; Vaughan, Brian; Cullen, Charlie; Campbell, Dermot; McDonnell, Ciaran; Coyle, Eugene

    2008-01-01

    Acoustic/prosodic feature (a/p) convergence has been known to occur both in dialogues between humans, as well as in human-computer interactions. Understanding the form and function of convergence is desirable for developing next generation conversational agents, as this will help increase speech recognition performance and naturalness of synthesized speech. Currently, the underlying mechanisms by which continuous and bi-directional convergence occurs are not well understood. In this study, a ...

  15. Measurement of liquid surface acoustic wave amplitudes using HeNe laser homodyne techniques

    Science.gov (United States)

    Hickman, G. D.; Hsu, Y. L.; Lee, M. S.; Bourgeois, B. S.; Hsieh, S. T.

    1988-01-01

    Recent results in the measurement of small amplitude acoustic waves on the water surface are presented. The research was performed using laser homodyne techniques in a small laboratory water tank. The homodyne system consists of optical, acoustic, and data acquisition subsystems. The optical subsystem includes an HeNe laser and polarizing components. THe acoustic subsystem consists of standard low power transducers and a power amplifier. The data acquisition subsystem includes a spectrum analyzer and a personal computer. Measurements were made in the acoustic frequency range of 15 - 23 kHz and sound pressure levels of 120-180 dB re 1 micropascal. It is estimated that the homodyne technique can detect surface amplitude deformations on the order of 90 A.

  16. Automated, Miniaturized Instrument for Measuring Gene Expression in Space

    Science.gov (United States)

    Pohorille, A.; Peyvan, K.; Danley, D.; Ricco, A. J.

    2010-01-01

    To facilitate astrobiological studies on the survival and adaptation of microorganisms and mixed microbial cultures to space environment, we have been developing a fully automated, miniaturized system for measuring their gene expression on small spacecraft. This low-cost, multi-purpose instrument represents a major scientific and technological advancement in our ability to study the impact of the space environment on biological systems by providing data on cellular metabolism and regulation orders of magnitude richer than what is currently available. The system supports growth of the organism, lyse it to release the expressed RNA, label the RNA, read the expression levels of a large number of genes by microarray analysis of labeled RNA and transmit the measurements to Earth. To measure gene expression we use microarray technology developed by CombiMatrix, which is based on electrochemical reactions on arrays of electrodes on a semiconductor substrate. Since the electrical integrity of the microarray remains intact after probe synthesis, the circuitry can be employed to sense nucleic acid binding at each electrode. CombiMatrix arrays can be sectored to allow multiple samples per chip. In addition, a single array can be used for several assays. The array has been integrated into an automated microfluidic cartridge that uses flexible reagent blisters and pinch pumping to move liquid reagents between chambers. The proposed instrument will help to understand adaptation of terrestrial life to conditions beyond the planet of origin, identify deleterious effects of the space environment, develop effective countermeasures against these effects, and test our ability to sustain and grow in space organisms that can be used for life support and in situ resource utilization during long-duration space exploration. The instrument is suitable for small satellite platforms, which provide frequent, low cost access to space. It can be also used on any other platform in space

  17. A comparison of rainfall measurements from multiple instruments

    Science.gov (United States)

    Liu, X. C.; Gao, T. C.; Liu, L.

    2013-07-01

    Simultaneous observations of rainfall collected by a tipping bucket rain gauge (TBRG), a weighing rain gauge (WRG), an optical rain gauge (ORG), a present weather detector (PWD), a Joss-Waldvogel disdrometer (JWD), and a 2-D video disdrometer (2DVD) during January to October 2012 were analyzed to evaluate how accurately they measure rainfall and drop size distributions (DSDs). For the long-term observations, there were different discrepancies in rain amounts from six instruments on the order of 0% to 27.7%. The TBRG, WRG, and ORG have a good agreement, while the PWD and 2DVD record higher and the JWD lower rain rates when R > 20 mm h-1, the ORG agrees well with JWD and 2DVD, while the TBRG records higher and the WRG lower rain rates when R > 20 mm h-1. Compared with the TBRG and WRG, optical and impact instruments can measure the rain rate accurately in the light rain. The overall DSDs of JWD and 2DVD agree well with each other, except for the small raindrops (D rain rate regimes. But small raindrops might be underestimated by 2DVD when R > 15 mm h-1. The small raindrops tend to be omitted in the more large-size raindrops due to the shadow effect of light. Therefore, the measurement accuracy of small raindrops in the heavy rainfall from 2DVD should be handled carefully.

  18. A comparison of rainfall measurements from multiple instruments

    Directory of Open Access Journals (Sweden)

    X. C. Liu

    2013-07-01

    Full Text Available Simultaneous observations of rainfall collected by a tipping bucket rain gauge (TBRG, a weighing rain gauge (WRG, an optical rain gauge (ORG, a present weather detector (PWD, a Joss–Waldvogel disdrometer (JWD, and a 2-D video disdrometer (2DVD during January to October 2012 were analyzed to evaluate how accurately they measure rainfall and drop size distributions (DSDs. For the long-term observations, there were different discrepancies in rain amounts from six instruments on the order of 0% to 27.7%. The TBRG, WRG, and ORG have a good agreement, while the PWD and 2DVD record higher and the JWD lower rain rates when R > 20 mm h−1, the ORG agrees well with JWD and 2DVD, while the TBRG records higher and the WRG lower rain rates when R > 20 mm h−1. Compared with the TBRG and WRG, optical and impact instruments can measure the rain rate accurately in the light rain. The overall DSDs of JWD and 2DVD agree well with each other, except for the small raindrops (D D D R > 15 mm h−1. The small raindrops tend to be omitted in the more large-size raindrops due to the shadow effect of light. Therefore, the measurement accuracy of small raindrops in the heavy rainfall from 2DVD should be handled carefully.

  19. Solar radius measurements with the space instrument HMI (SDO)

    Science.gov (United States)

    Irbah, Abdanour; Hauchecorne, Alain; Meftah, Mustapha; Damé, Luc; Keckhut, Philippe

    2016-04-01

    The solar radius variations and its effects on the Earth climate are still a long scientific debate. The observed variations from ground experiments were not totally admitted and several space missions have had these measures as a goal. The high angular resolution of radius measurements and its long-term trend is however a challenge in space. The first attempts with MDI (Soho) then SODISM (PICARD) and HMI (SDO) revealed the difficulties of such measures due to the hostile environment which introduces thermal variations on the instruments all along the satellite orbit. These variations have non-negligible impacts on the optical properties of the onboard telescopes and therefore on the images and the parameters which are extracted such as the solar radius. We need then to make a posteriori corrections using the thermal housekeeping's recorded together with the data science. We present here how we make such correction on the solar radius obtained from the HMI images. We will then compare and discuss the results with the solar radius recorded at 607 nm with the ground-based instrument of PICARD.

  20. Solar ultraviolet irradiance measurements, instrumentation, intercomparisons and interpretations

    Energy Technology Data Exchange (ETDEWEB)

    Thorseth, Trond Morten

    2000-07-01

    The thesis reports studies of stabile instruments that are capable of detecting small alterations in ultraviolet irradiation over a long period. A central theme in the work has been to improve the measuring systems for continuous research based monitoring of natural variations in the ultraviolet irradiation from the sun. Methods for controlling the stability and continually secure the quality of the collected data. The causes of measuring errors are mapped and methods for the correction of collected data are developed. The methods and measuring systems for collecting the data have been adapted to the Norwegian climate and geography. The work has lead to an increased understanding of the natural variation in the ultraviolet radiation from the sun and what factors in the atmosphere that influences the process. The collected data and the developed methods for the quality control have increased the understanding of the ultraviolet irradiation climate in Europe.

  1. Instrumental objective measurement of veal calves carcass colour at slaughterhouse

    OpenAIRE

    Stefano Vandoni; Carlo Angelo Sgoifo Rossi

    2010-01-01

    A total of 6700 veal calves were used to compare the ability of chromameter CR300 in measuring the veal meat colour on-line at slaughterhouse and to develop a prediction equation of colour score based on relationship between instrumental and visual assessments. A total of 5000 carcasses were used to develop equation of prediction while 1700 were used to test it. The meat colour was assessed subjectively in 3 different slaughterhouses by the slaughterhouse’s judges 10h post mortem and ob...

  2. 4th Pacific Rim Underwater Acoustics Conference

    CERN Document Server

    Xu, Wen; Cheng, Qianliu; Zhao, Hangfang

    2016-01-01

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

  3. Comparison between psycho-acoustics and physio-acoustic measurement to determine optimum reverberation time of pentatonic angklung music concert hall

    Science.gov (United States)

    Sudarsono, Anugrah S.; Merthayasa, I. G. N.; Suprijanto

    2015-09-01

    This research tried to compare psycho-acoustics and Physio-acoustic measurement to find the optimum reverberation time of soundfield from angklung music. Psycho-acoustic measurement was conducted using a paired comparison method and Physio-acoustic measurement was conducted with EEG Measurement on T3, T4, FP1, and FP2 measurement points. EEG measurement was conducted with 5 persons. Pentatonic angklung music was used as a stimulus with reverberation time variation. The variation was between 0.8 s - 1.6 s with 0.2 s step. EEG signal was analysed using a Power Spectral Density method on Alpha Wave, High Alpha Wave, and Theta Wave. Psycho-acoustic measurement on 50 persons showed that reverberation time preference of pentatonic angklung music was 1.2 second. The result was similar to Theta Wave measurement on FP2 measurement point. High Alpha wave on T4 measurement gave different results, but had similar patterns with psycho-acoustic measurement

  4. Measurement of the acoustic nonlinearity parameter B/A of lossy medium in a focused field

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    An analytical description for the linear and nonlinear acoustic fields in lossy medium of a focusing source is derived. The relationship of pressure amplitudes at focus for fundamental and the second harmonic waves is discussed. At high linear focusing gain G, a new method using the insert substitution method for measuring the acoustic nonlinear parameter B /A of biological tissues is presented. Results for some biological tissues are experimentally obtained.

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

    Science.gov (United States)

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

    2016-01-01

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

  6. Comparison of acoustical and optical zooplankton measurements using an acoustic scattering model: A case study from the Arctic frontal zone

    Directory of Open Access Journals (Sweden)

    Szczucka Joanna

    2016-03-01

    Full Text Available High-frequency acoustic measurements supplemented by a modern optical method, Laser Optical Plankton Counter (LOPC, allowed us to perform a comparative analysis through the application of a mathematical model. We have studied the correspondence between measured and modelled echoes from zooplankton aggregations consisted mainly of two Calanus species. Data were collected from the upper 50 m water layer within the hydrographical frontal zone on the West Spitsbergen Shelf. The application of a “high-pass” model of sound scattering by fluid-like particles to the distribution of zooplankton sizes measured by LOPC resulted mostly in very good agreement between the measured (420 kHz BioSonics and modelled values, except for cases with very low zooplankton abundance or with occurrence of stronger scatterers (e.g. macrozooplankton, fish. An acoustic model validated for the elastic parameters of zooplankton confirmed that particles smaller than 1mmin diameter, although highly abundant, did not contribute significantly to the sound scattering process at a frequency of 420 kHz. The implementation of diverse complementary methods has great potential to obtain high spatial and temporal resolution in zooplankton distribution studies; however, their compatibility has to be tested first.

  7. A Methodology to Integrate Magnetic Resonance and Acoustic Measurements for Reservoir Characterization

    Energy Technology Data Exchange (ETDEWEB)

    Parra, Jorge O.; Hackert, Chris L.; Collier, Hughbert A.; Bennett, Michael

    2002-01-29

    The objective of this project was to develop an advanced imaging method, including pore scale imaging, to integrate NMR techniques and acoustic measurements to improve predictability of the pay zone in hydrocarbon reservoirs. This is accomplished by extracting the fluid property parameters using NMR laboratory measurements and the elastic parameters of the rock matrix from acoustic measurements to create poroelastic models of different parts of the reservoir. Laboratory measurement techniques and core imaging are being linked with a balanced petrographical analysis of the core and theoretical model.

  8. A Methodology to Integrate Magnetic Resonance and Acoustic Measurements for Reservoir Characterization

    Energy Technology Data Exchange (ETDEWEB)

    Parra, Ph.D., Jorge O.

    2002-06-10

    The objective of the project was to develop an advanced imaging method, including pore scale imaging, to integrate nuclear magnetic resonance (NMR) techniques and acoustic measurements to improve predictability of the pay zone in hydrocarbon reservoirs. This will be accomplished by extracting the fluid property parameters using NMR laboratory measurements and the elastic parameters of the rock matrix from acoustic measurements to create poroelastic models of different parts of the reservoir. Laboratory measurement techniques and core imaging were linked with a balanced petrographical analysis of cores and theoretical modeling.

  9. Instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Decreton, M

    2000-07-01

    SCK-CEN's research and development programme on instrumentation aims at evaluating the potentials of new instrumentation technologies under the severe constraints of a nuclear application. It focuses on the tolerance of sensors to high radiation doses, including optical fibre sensors, and on the related intelligent data processing needed to cope with the nuclear constraints. Main achievements in these domains in 1999 are summarised.

  10. Measurement uncertainties physical parameters and calibration of instruments

    CERN Document Server

    Gupta, S V

    2012-01-01

    This book fulfills the global need to evaluate measurement results along with the associated uncertainty. In the book, together with the details of uncertainty calculations for many physical parameters, probability distributions and their properties are discussed. Definitions of various terms are given and will help the practicing metrologists to grasp the subject. The book helps to establish international standards for the evaluation of the quality of raw data obtained from various laboratories for interpreting the results of various national metrology institutes in an international inter-comparisons. For the routine calibration of instruments, a new idea for the use of pooled variance is introduced. The uncertainty calculations are explained for (i) independent linear inputs, (ii) non-linear inputs and (iii) correlated inputs. The merits and limitations of the Guide to the Expression of Uncertainty in Measurement (GUM) are discussed. Monte Carlo methods for the derivation of the output distribution from the...

  11. Measurement of acoustic field radiated by low frequency power ultrasonic transducer with laser-interferometer

    Institute of Scientific and Technical Information of China (English)

    QIAN Menglu; GAO Wen; HU Wenxiang

    2000-01-01

    Based on the piezo-optic effect of medium, the refractive index of medium is the function of its density, and so it's also the function of acoustic pressure. Therefore, acoustic pressure in the optical path everywhere can be determined absolutely by laser-interferometric technique and relative distribution of pressure in the middle and far acoustic field, which can be obtained from theory or experiment respectively. Theory and experiment of measurement of pressure in acoustic field with laser-interferometer are introduced. Distribution of pressure radiated by a power ultrasonic transducer is determined by laser interferometric technique.The theoretical and experimental results are in good agreement. The receiving sensitivity of a PVDF (Polyvinylidene fluoride) transducer in free field is also calibrated absolutely due to above results and its sensitivity is -118.5 dB.

  12. Instrumentation for the measurement of autofluorescence in human skin

    Science.gov (United States)

    Graaff, Reindert; Meerwaldt, Robbert; Lutgers, Helen L.; Baptist, Rene; de Jong, Ed D.; Zijp, Jaap R.; Links, Thera P.; Smit, Andries J.; Rakhorst, Gerhard

    2005-04-01

    A setup to measure skin autofluorescence was developed to assess accumulation of advanced glycation endproducts (AGE) in patients noninvasively. The method applies direct blacklight tube illumination of the skin of the lower arm, and spectrometry. The setup displays skin autofluorescence (AF) as a ratio of mean intensities detected from the skin between 420-600 nm and 300-420 nm, respectively. In an early clinical application in 46 and control subjects matched for age and gender, AF was significantly increased in the patients (p = 0.015), and highly correlated with skin AGE's that were determined from skin biopsies in both groups. A large follow-up study on type 2 diabetes mellitus, ongoing since 2001 with more than 1000 subjects, aims to assess the value of the instrument in predicting chronic complications of diabetes. At baseline, a relation with age, glycemic status and with complications present was found. In a study in patients with end stage renal disease on dialysis AF was a strong and independent predictor of total and cardiovascular mortality. A commercial version of this AGE-reader is now under development and becomes available early 2005 (DiagnOptics B.V., Groningen, The Netherlands). One of the remaining questions, that will be answered by measuring so-called Exciation-Emission Matrices (EEM's) of the skin tissue in vivo, is whether a more selective choice of wavelengths is more strongly related to clinical characteristics. An experimental instrument to measure these EEM's was, therefore, developed as well. Clinical measurements are underway of EEM's in patient groups with diabetes mellitus and in healthy volunteers.

  13. Analyzing excitation forces acting on a plate based on measured acoustic pressure.

    Science.gov (United States)

    Wu, Sean F; Zhou, Pan

    2016-07-01

    This paper presents a theoretical study on "seeing" through an elastic structure to uncover the root cause of sound and vibration by using nearfield acoustical holography (NAH) and normal modes expansion. This approach is of generality because vibro-acoustic responses on the surface of a vibrating structure can always be reconstructed, exactly or approximately. With these vibro-acoustic responses, excitation forces acting on the structure can always be determined, analytically or numerically, given any set of boundary conditions. As an example, the explicit formulations for reconstructing time-harmonic excitation forces, including point, line and surface forces, and their arbitrary combinations acting on a rectangular thin plate in vacuum mounted on an infinite baffle are presented. The reason for choosing this example is that the analytic solutions to vibro-acoustic responses are available, and in-depth analyses of results are possible. Results demonstrate that this approach allows one to identify excitation forces based on measured acoustic pressures and reveal their characteristics such as locations, types and amplitudes, as if one could "see" excitation forces acting behind the plate based on acoustic pressure measured on the opposite side. This approach is extendable to general elastic structures, except that in such circumstance numerical results must be sought. PMID:27475174

  14. Results of acoustic measurements during leak simulation experiments on a sodium-heated modular steam generator

    International Nuclear Information System (INIS)

    After a short description of the experimental arrangement at the micro-modular steam generator of the BOR-60 LMFBR Power Plant the acoustic measuring chains and their main properties are introduced. Acoustic signals of the background as well as the leak-induced noise have been analysed in frequency and time domain, respectively. One essential result is that frequency analysis of acoustic signals cannot be recommended as leak detection method. On the other hand, certain signal characteristics derived from signal analysis in time domain have been shown to meet the expectation of a considerable change in magnitude, even if a small water-to-sodium leak is occurring. Besides direct sound emitted in the leak region a secondary sound initiated in the vicinity of the acoustic transducer by reaction products of the sodium-water-reaction has been measured. Both of them have been used for acoustic detection of small leaks. The acoustic response of the modular steam generator to a large leak is characterized by a sudden considerable increase in sound level. Finally, some conclusions drawn from experimental results are presented. (author)

  15. IRCM spectral signature measurements instrumentation featuring enhanced radiometric accuracy

    Science.gov (United States)

    Lantagne, Stéphane; Prel, Florent; Moreau, Louis; Roy, Claude; Willers, Cornelius J.

    2015-10-01

    Hyperspectral Infrared (IR) signature measurements are performed in military applications including aircraft- and -naval vessel stealth characterization, detection/lock-on ranges, and flares efficiency characterization. Numerous military applications require high precision measurement of infrared signature characterization. For instance, Infrared Countermeasure (IRCM) systems and Infrared Counter-Countermeasure (IRCCM) system are continuously evolving. Infrared flares defeated IR guided seekers, IR flares became defeated by intelligent IR guided seekers and Jammers defeated the intelligent IR guided seekers [7]. A precise knowledge of the target infrared signature phenomenology is crucial for the development and improvement of countermeasure and counter-countermeasure systems and so precise quantification of the infrared energy emitted from the targets requires accurate spectral signature measurements. Errors in infrared characterization measurements can lead to weakness in the safety of the countermeasure system and errors in the determination of detection/lock-on range of an aircraft. The infrared signatures are analyzed, modeled, and simulated to provide a good understanding of the signature phenomenology to improve the IRCM and IRCCM technologies efficiency [7,8,9]. There is a growing need for infrared spectral signature measurement technology in order to further improve and validate infrared-based models and simulations. The addition of imagery to Spectroradiometers is improving the measurement capability of complex targets and scenes because all elements in the scene can now be measured simultaneously. However, the limited dynamic range of the Focal Plane Array (FPA) sensors used in these instruments confines the ranges of measurable radiance intensities. This ultimately affects the radiometric accuracy of these complex signatures. We will describe and demonstrate how the ABB hyperspectral imaging spectroradiometer features enhanced the radiometric accuracy

  16. Long-term continuous acoustical suspended-sediment measurements in rivers - Theory, application, bias, and error

    Science.gov (United States)

    Topping, David J.; Wright, Scott A.

    2016-05-04

    It is commonly recognized that suspended-sediment concentrations in rivers can change rapidly in time and independently of water discharge during important sediment‑transporting events (for example, during floods); thus, suspended-sediment measurements at closely spaced time intervals are necessary to characterize suspended‑sediment loads. Because the manual collection of sufficient numbers of suspended-sediment samples required to characterize this variability is often time and cost prohibitive, several “surrogate” techniques have been developed for in situ measurements of properties related to suspended-sediment characteristics (for example, turbidity, laser-diffraction, acoustics). Herein, we present a new physically based method for the simultaneous measurement of suspended-silt-and-clay concentration, suspended-sand concentration, and suspended‑sand median grain size in rivers, using multi‑frequency arrays of single-frequency side‑looking acoustic-Doppler profilers. The method is strongly grounded in the extensive scientific literature on the incoherent scattering of sound by random suspensions of small particles. In particular, the method takes advantage of theory that relates acoustic frequency, acoustic attenuation, acoustic backscatter, suspended-sediment concentration, and suspended-sediment grain-size distribution. We develop the theory and methods, and demonstrate the application of the method at six study sites on the Colorado River and Rio Grande, where large numbers of suspended-sediment samples have been collected concurrently with acoustic attenuation and backscatter measurements over many years. The method produces acoustical measurements of suspended-silt-and-clay and suspended-sand concentration (in units of mg/L), and acoustical measurements of suspended-sand median grain size (in units of mm) that are generally in good to excellent agreement with concurrent physical measurements of these quantities in the river cross sections at

  17. Long-term continuous acoustical suspended-sediment measurements in rivers - Theory, application, bias, and error

    Science.gov (United States)

    Topping, David J.; Wright, Scott A.

    2016-01-01

    It is commonly recognized that suspended-sediment concentrations in rivers can change rapidly in time and independently of water discharge during important sediment‑transporting events (for example, during floods); thus, suspended-sediment measurements at closely spaced time intervals are necessary to characterize suspended‑sediment loads. Because the manual collection of sufficient numbers of suspended-sediment samples required to characterize this variability is often time and cost prohibitive, several “surrogate” techniques have been developed for in situ measurements of properties related to suspended-sediment characteristics (for example, turbidity, laser-diffraction, acoustics). Herein, we present a new physically based method for the simultaneous measurement of suspended-silt-and-clay concentration, suspended-sand concentration, and suspended‑sand median grain size in rivers, using multi‑frequency arrays of single-frequency side‑looking acoustic-Doppler profilers. The method is strongly grounded in the extensive scientific literature on the incoherent scattering of sound by random suspensions of small particles. In particular, the method takes advantage of theory that relates acoustic frequency, acoustic attenuation, acoustic backscatter, suspended-sediment concentration, and suspended-sediment grain-size distribution. We develop the theory and methods, and demonstrate the application of the method at six study sites on the Colorado River and Rio Grande, where large numbers of suspended-sediment samples have been collected concurrently with acoustic attenuation and backscatter measurements over many years. The method produces acoustical measurements of suspended-silt-and-clay and suspended-sand concentration (in units of mg/L), and acoustical measurements of suspended-sand median grain size (in units of mm) that are generally in good to excellent agreement with concurrent physical measurements of these quantities in the river cross sections at

  18. Acoustic P-wave velocity measurements of cataclastic effects in rock salt

    International Nuclear Information System (INIS)

    Model tests are carried out, in order to investigate the cataclastic thermo-mechanical behaviour of rock salt around a simulated repository borehole. The measurements are performed during a transient period of heating and subsequent cooling. Acoustic crosshole measurements are carried out under conditions of compression, scale 1: 41/2. The relationship between cataclastic effects and the acoustic velocity differences is described. Macrofracturing only occurred under circumstances of cooling, when a heater was switched off. One of the model tests was used in the CEC benchmark exercise ''COSA''. Acoustic measuring tubes have been developed for the in situ research on structural changes in rock salt. The tests involved the performance of so-called hole measurements in two parallel boreholes, containing the measuring tubes. The most important observations of a test in an old room in the Asse Mine are the following. A bifurcating open fissure, about 6 to 8 mm wide, prevented the propagation of the acoustic wave; this demonstrates that such cracks and fissures are easily detectable by the applied method. The microcataclasis, particularly that near the roomside wall, causes a reduction of the acoustic velocities, the more so as the angle between the measuring direction and the roomside wall increases. During the injection of a gallery wall with epoxy resins (by GSF) acoustic crosshole measurements were carried out as well. A detailed picture was obtained of the process of the closing of the fractures. By core drilling after this test confirmation was obtained that the fractures were closed. The information that has been gathered, will be used for the interpretation of the crosshole measurements in the near future; these measurements will be carried out around a heater borehole in the HAW field, a large underground test (GSF-ECN)

  19. Pseudo working-point control measurement scheme for acoustic sensitivity of interferometric fiber-optic hydrophones

    Institute of Scientific and Technical Information of China (English)

    Zefeng Wang; Yongming Hu; Zhou Meng; Ming Ni

    2008-01-01

    A novel pseudo working-point control measurement scheme for the acoustic sensitivity of interferometric fiber-optic hydrophones is described and demonstrated.The measurement principle is introduced in detail.An experimental system,which interrogates an interferometric fiber-optic hydrophone with this method,is designed.The acoustic pressure phase sensitivity of the fiber-optic hydrophone is measured over the frequency range of 20-2500Hz.The measured acoustic sensitivity is about-156.5dB re 1rad/μPa with a fluctuation lower than ±1.2dB,which is in good agreement with the results obtained by the method of phase generated carrier.The experimental results testify the validity of this new method which has the advantages of no electric elements in the sensing head,the simplicity of signal processing,and wide working bandwidth.

  20. New Instruments and Principles for the Dimensional Measurement and Measurement of Spacing of Reactor Components

    International Nuclear Information System (INIS)

    Full text: The measurement of wall thickness of austenitic and non-ferrous sheets, tubes and containers is presented. Two methods for contactless measurement are discussed: eddy- current method for measuring the thickness of non-ferrous and austenitic sheets and containers by means of transition coils; eddy-current measurement of the wall thickness of tubes by means of feed-through coils. Suitable instruments and their application are shown. Wall-thickness measurement on non-ferrous reactor assemblies by the ''magnetic ball method'' is also discussed. The principle of this new type of measurement is explained, its range of use - especially for spot- measurements - is discussed, and a practical instrument is described. Measurement of non-magnetic coatings on magnetic base materials is discussed. The measurement principles (magnetic DC and AC field methods) are explained and instruments for measurement of nonmagnetic coatings between 3-μm and 20-mm thickness are shown. The special problem of measurement of stellite deposits on ferritic walls of reactor vessels is discussed. The measurement of electrically non-conductive coatings on base materials consisting of non-ferrous metals; and the principle of measurement (eddy currents) are explained. An instrument for this purpose is shown and typical examples of measurements are given. Contactless in-line measurements of physical dimensions of metallic reactor components are given. Various methods for ferrous and non-ferrous metals are explained (magnetic DC and AC field method, eddy-current methods). Instruments and examples for remote measurements of diameter, ovality, distortion etc., of reactor components are described, and methods of measuring the spacing of such components in the ''hot'' zone of the reactor are shown. An instrument for recording the surface profile and for direct reading the roughness values (''Rauhtiefe'', ''Glättungstiefe'', CLA value and RMS value) is shown. Typical examples of the use of the

  1. A miniDOAS instrument optimised for ammonia field measurements

    Science.gov (United States)

    Sintermann, Jörg; Dietrich, Klaus; Häni, Christoph; Bell, Michael; Jocher, Markus; Neftel, Albrecht

    2016-06-01

    We present a differential optical absorption spectroscopy (DOAS) instrument, called "miniDOAS", optimised for optical open-path field-measurements of ambient ammonia (NH3) alongside nitrogen oxide (NO) and sulfur dioxide (SO2). The instrument is a further development of the miniDOAS presented by Volten et al. (2012). We use a temperature-controlled spectrometer, a deuterium light source and a modified optical arrangement. The system was set up in a robust, field-deployable, temperature-regulated housing. For the evaluation of light spectra we use a new high-pass filter routine based upon robust baseline extraction with local regression. Multiple linear regression including terms of an autoregressive-moving-average model is used to determine concentrations. For NH3 the random uncertainty is about 1.4 % of the concentration, and not better than 0.2 µg m-3. Potential biases for the slope of the calibration are given by the precision of the differential absorption cross sections (±3 %) and for the offset by the precision of the estimation of concentration offsets (cref) introduced by the reference spectrum Iref. Comparisons of miniDOAS measurements to those by NH3 acid trap devices showed good agreement. The miniDOAS can be flexibly used for a wide range of field trials, such as micrometeorological NH3 flux measurements with approaches based upon horizontal or vertical concentration differences. Results from such applications covering concentration dynamics of less than one up to several hundreds of µg m-3 are presented.

  2. An instrument for simultaneous EQCM impedance and SECM measurements.

    Science.gov (United States)

    Gollas, B; Bartlett, P N; Denuault, G

    2000-01-15

    A novel combination of an electrochemical quartz crystal microbalance (EQCM) and a scanning electrochemical microscope (SECM) has been built. Unlike conventional EQCMs, the instrument described here allows rapid in situ measurement of the modulus of the quartz crystal's transfer function. Data analysis in the complex plane for the Butterworth-Van Dyke (BVD) equivalent circuit yields the real and the imaginary components R (damping resistance) and XL (reactive inductance) of the crystal's electroacoustic impedance around its resonant frequency of 10 MHz. The influence of different tip shapes of an approaching microelectrode on the electroacoustic impedance of the quartz crystal was studied and found to be minimal for certain geometries. The capability of the EQCM/SECM instrument was tested in cyclic voltammetric plating/stripping experiments using a copper(I) chloride solution of high concentration in 1 M HCl. Four parameters, XL, R, the substrate, and the tip current, can be recorded simultaneously. Depletion layer effects were observed and could be corrected for to yield accurate current efficiencies for potentiodynamic and potentiostatic copper plating. The amperometric response of the SECM tip positioned closely to the substrate reflects the concentration changes of electroactive ions in the diffusion layer of the substrate electrode. PMID:10658330

  3. Set of instruments for measuring the characteristics of optical waveguides in a production environment

    Directory of Open Access Journals (Sweden)

    V. A. Svirid

    1986-04-01

    Full Text Available Developed a set of instruments, which includes instruments for measuring aperture characteristics of OB, OB dispersion characteristics and the loss agents. Considered applicable measurement methods, the design and specifications of the devices.

  4. Accuracy, Precision, and Resolution in Strain Measurements on Diffraction Instruments

    Science.gov (United States)

    Polvino, Sean M.

    Diffraction stress analysis is a commonly used technique to evaluate the properties and performance of different classes of materials from engineering materials, such as steels and alloys, to electronic materials like Silicon chips. Often to better understand the performance of these materials at operating conditions they are also commonly subjected to elevated temperatures and different loading conditions. The validity of any measurement under these conditions is only as good as the control of the conditions and the accuracy and precision of the instrument being used to measure the properties. What is the accuracy and precision of a typical diffraction system and what is the best way to evaluate these quantities? Is there a way to remove systematic and random errors in the data that are due to problems with the control system used? With the advent of device engineering employing internal stress as a method for increasing performance the measurement of stress from microelectronic structures has become of enhanced importance. X-ray diffraction provides an ideal method for measuring these small areas without the need for modifying the sample and possibly changing the strain state. Micro and nano diffraction experiments on Silicon-on-Insulator samples revealed changes to the material under investigation and raised significant concerns about the usefulness of these techniques. This damage process and the application of micro and nano diffraction is discussed.

  5. Does an instrumented treadmill correctly measure the ground reaction forces?

    Directory of Open Access Journals (Sweden)

    Patrick A. Willems

    2013-11-01

    Since the 1990s, treadmills have been equipped with multi-axis force transducers to measure the three components of the ground reaction forces during walking and running. These measurements are correctly performed if the whole treadmill (including the motor is mounted on the transducers. In this case, the acceleration of the treadmill centre of mass relative to the reference frame of the laboratory is nil. The external forces exerted on one side of the treadmill are thus equal in magnitude and opposite in direction to the external forces exerted on the other side. However, uncertainty exists about the accuracy of these measures: due to friction between the belt and the tread-surface, due to the motor pulling the belt, some believe that it is not possible to correctly measure the horizontal components of the forces exerted by the feet on the belt. Here, we propose a simple model of an instrumented treadmill and we demonstrate (1 that the forces exerted by the subject moving on the upper part of the treadmill are accurately transmitted to the transducers placed under it and (2 that all internal forces – including friction – between the parts of the treadmill are cancelling each other.

  6. Temperatures stabilization of a field instrument for uranium enrichment measurements

    Energy Technology Data Exchange (ETDEWEB)

    Shepard, R.; Wawrowski, S.; Charland, M. [Canberra Industries, Inc., Meriden, CT (United States)] [and others

    1996-12-31

    Enrichment measurements with sodium iodide (NaI) detectors are hampered with a number of problems related to the temperature behavior of NaI crystals and the associated electronics. This problem is of particular concern in applications requiring the use of fixed regions of interest; such applications are used by the International Atomic Energy Agency (IAEA) in Vienna. The Canberra IMCA is a new portable instrument for such applications which can use either a NaI or a Ge detector. In developing the IMCA to meet the IAEA requirements for NaI detectors, Canberra has designed a system with a new temperature stabilization method capable of maintaining the detector stability at 0.5% over a temperature range of -10 to +50{degrees}C. This paper includes a detailed description of this IMCA temperature stabilization system, as well as test results for a range of temperatures using uranium standards.

  7. Smart phone-based Chemistry Instrumentation: Digitization of Colorimetric Measurements

    International Nuclear Information System (INIS)

    This report presents a mobile instrumentation platform based on a smart phone using its built-in functions for colorimetric diagnosis. The color change as a result of detection is taken as a picture through a CCD camera built in the smart phone, and is evaluated in the form of the hue value to give the well-defined relationship between the color and the concentration. To prove the concept in the present work, proton concentration measurements were conducted on pH paper coupled with a smart phone for demonstration. This report is believed to show the possibility of adapting a smart phone to a mobile analytical transducer, and more applications for bioanalysis are expected to be developed using other built-in functions of the smart phone

  8. Broadband electrostatic acoustic transducer for ultrasonic measurements in liquids.

    Science.gov (United States)

    Cantrell, J H; Heyman, J S; Yost, W T; Torbett, M A; Breazeale, M A

    1979-01-01

    A broadband capacitive electrostatic acoustic transducer (ESAT) has been developed for use in a liquid environment at megahertz frequencies. The ESAT basically consists of a thin conductive membrane stretched over a metallic housing. The membrane functions as the ground plate of a parallel plate capacitor, the other plate being a dc biased electrode recessed approximately 10 mum from the electrically grounded membrane. An ultrasonic wave incident on the membrane varies the membrane-electrode gap spacing and generates an electrical signal proportional to the wave amplitude. The entire assembly is sealed for immersion in a liquid environment. Calibration of the ESAT with incident ultrasonic waves of constant displacement amplitude from 1 to 15 MHz reveals a decrease in signal response with increasing frequency independent of membrane tension. The use of the ESAT as a broadband ultrasonic transducer in liquids with a predictable frequency response is promising.

  9. Measurement Combination for Acoustic Source Localization in a Room Environment

    Directory of Open Access Journals (Sweden)

    Pertilä Pasi

    2008-01-01

    Full Text Available The behavior of time delay estimation (TDE is well understood and therefore attractive to apply in acoustic source localization (ASL. A time delay between microphones maps into a hyperbola. Furthermore, the likelihoods for different time delays are mapped into a set of weighted nonoverlapping hyperbolae in the spatial domain. Combining TDE functions from several microphone pairs results in a spatial likelihood function (SLF which is a combination of sets of weighted hyperbolae. Traditionally, the maximum SLF point is considered as the source location but is corrupted by reverberation and noise. Particle filters utilize past source information to improve localization performance in such environments. However, uncertainty exists on how to combine the TDE functions. Results from simulated dialogues in various conditions favor TDE combination using intersection-based methods over union. The real-data dialogue results agree with the simulations, showing a 45% RMSE reduction when choosing the intersection over union of TDE functions.

  10. Measurement of Aqueous Foam Rheology by Acoustic Levitation

    Science.gov (United States)

    McDaniel, J. Gregory; Holt, R. Glynn; Rogers, Rich (Technical Monitor)

    2000-01-01

    An experimental technique is demonstrated for acoustically levitating aqueous foam drops and exciting their spheroidal modes. This allows fundamental studies of foam-drop dynamics that provide an alternative means of estimating the viscoelastic properties of the foam. One unique advantage of the technique is the lack of interactions between the foam and container surfaces, which must be accounted for in other techniques. Results are presented in which a foam drop with gas volume fraction phi = 0.77 is levitated at 30 kHz and excited into its first quadrupole resonance at 63 +/- 3 Hz. By modeling the drop as an elastic sphere, the shear modulus of the foam was estimated at 75 +/- 3 Pa.

  11. Measuring baryon acoustic oscillations with future SKA surveys

    CERN Document Server

    Bull, Philip; Raccanelli, Alvise; Blake, Chris; Ferreira, Pedro G; Santos, Mario G; Schwarz, Dominik J

    2015-01-01

    The imprint of baryon acoustic oscillations (BAO) in large-scale structure can be used as a standard ruler for mapping out the cosmic expansion history, and hence for testing cosmological models. In this article we briefly describe the scientific background to the BAO technique, and forecast the potential of the Phase 1 and 2 SKA telescopes to perform BAO surveys using both galaxy catalogues and intensity mapping, assessing their competitiveness with current and future optical galaxy surveys. We find that a 25,000 sq. deg. intensity mapping survey on a Phase 1 array will preferentially constrain the radial BAO, providing a highly competitive 2% constraint on the expansion rate at z ~ 2. A 30,000 sq. deg. galaxy redshift survey on SKA2 will outperform all other planned experiments for z < 1.4.

  12. Methods of temperature measurement in a radio-acoustic tropospheric sounder

    Directory of Open Access Journals (Sweden)

    P. TRIVERO

    1976-06-01

    Full Text Available The temperature of the lower troposphere is inferred
    by measuring with a doppler radar the speed of a powerful acoustic wave,
    capable of periodically perturbing the index of refraction of air. Three
    methods for performing these measurements are described.

  13. Wideband Acoustic Immittance: Normative Study and Test-Retest Reliability of Tympanometric Measurements in Adults

    Science.gov (United States)

    Sun, Xiao-Ming

    2016-01-01

    Purpose: The purpose of this study was to present normative data of tympanometric measurements of wideband acoustic immittance and to characterize wideband tympanograms. Method: Data were collected in 84 young adults with strictly defined normal hearing and middle ear status. Energy absorbance (EA) was measured using clicks for 1/12-octave…

  14. Final Report. Geothermal Dual Acoustic Tool for Measurement of Rock Stress

    Energy Technology Data Exchange (ETDEWEB)

    Normann, Randy A [Perma Works LLC, Pattonville, TX (United States)

    2014-12-01

    This paper outlines the technology need for a rock formation stress measurement in future EGS wells. This paper reports on the results of work undertaken under a Phase I, DOE/SBIR on the feasibility to build an acoustic well logging tool for measuring rock formation stress.

  15. Final Report: Geothermal dual acoustic tool for measurement of rock stress

    Energy Technology Data Exchange (ETDEWEB)

    Normann, Randy A. [Perma Works LLC, Pattonville, TX (United States)

    2014-12-01

    This paper outlines the technology need for a rock formation stress measurement in future EGS wells. This paper reports on the results of work undertaken under a Phase I, DOE/SBIR on the feasibility to build an acoustic well logging tool for measuring rock formation stress.

  16. Final Report: Geothermal Dual Acoustic Tool for Measurement of Rock Stress

    Energy Technology Data Exchange (ETDEWEB)

    Normann, Randy A.

    2014-12-01

    This paper outlines the technology need for a rock formation stress measurement in future EGS wells. This paper reports on the results of work undertaken under a Phase I, DOE/SBIR on the feasibility to build an acoustic well logging tool for measuring rock formation stress.

  17. Multi-instrument comparisons of D-region plasma measurements

    Directory of Open Access Journals (Sweden)

    M. Friedrich

    2013-01-01

    Full Text Available The ECOMA (Existence and Charge state Of Meteoric dust grains in the middle Atmosphere series of sounding rocket flights consisted of nine flights with almost identical payload design and flight characteristics. All flights carried a radio wave propagation experiment together with a variety of plasma probes. Three of these measured electron densities, two ion densities. The rockets were all launched from the Andøya Rocket Range, Norway, in four campaigns between 2006 and 2010. Emphasis is on the final three flights from 2010 where the payloads were equipped with four instruments capable of measuring plasma densities in situ, among them a novel probe flown for the first time in conjunction with a wave propagation experiment. Deviation factors of all probe data relative to the wave propagation results were derived and revealed that none of the probe data were close to the wave propagation results at all heights, but – more importantly – the instruments showed very different behaviour at different altitudes. The novel multi-needle Langmuir probe exhibits the best correlation to the wave propagation data, as there is minimal influence of the payload potential, but it is still subject to aerodynamics, especially at its location at the rear of the payload. For all other probe types, the deviation factor comes closer to unity with increasing plasma density. No systematic difference of the empirical deviation factor between day and night can be found. The large negative payload potential in the last three flights may be the cause for discrepancies between electron and ion probe data below 85 km.

  18. Instruments

    Energy Technology Data Exchange (ETDEWEB)

    Buehrer, W. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1996-12-31

    The present paper mediates a basic knowledge of the most commonly used experimental techniques. We discuss the principles and concepts necessary to understand what one is doing if one performs an experiment on a certain instrument. (author) 29 figs., 1 tab., refs.

  19. Acoustic measurements of the thermodynamic temperature between the triple point of mercury and 380 K

    Science.gov (United States)

    Benedetto, G.; Gavioso, R. M.; Spagnolo, R.; Marcarino, P.; Merlone, A.

    2004-02-01

    We have measured the differences between the Kelvin thermodynamic temperature and the temperature of the International Temperature Scale of 1990 on nine isotherms between the triple point of mercury and 380 K, by means of a primary acoustic thermometer. For the present measurements the standard uncertainty of (T - T90) ranges from 0.9 mK at 234 K to 1.7 mK at 380 K. The experimental method is based on the measurement of the acoustic resonance frequencies of an argon-filled spherical cavity and the microwave resonance frequencies of the same cavity when evacuated. The present results agree within the remarkably small combined uncertainties with both NIST acoustic thermometry ([1] Moldover M R et al 1999 J. Res. Natl Inst. Stand. Technol. 104 11-46 [2] Strouse G F et al 2002 Progress in primary acoustic thermometry at NIST: 273 K to 505 K 8th Temperature Symp. (Chicago, 21-24 October 2002)) and UCL acoustic thermometry ([3] Ewing M B and Trusler J P M 2000 J. Chem. Thermodyn. 32 1229-55) in the overlapping temperature range.

  20. Acoustic power measurement of high-intensity focused ultrasound transducer using a pressure sensor.

    Science.gov (United States)

    Zhou, Yufeng

    2015-03-01

    The acoustic power of high-intensity focused ultrasound (HIFU) is an important parameter that should be measured prior to each treatment to guarantee effective and safe outcomes. A new calibration technique was developed that involves estimating the pressure distribution, calculating the acoustic power using an underwater pressure blast sensor, and compensating the contribution of harmonics to the acoustic power. The output of a clinical extracorporeal HIFU system (center frequency of ~1 MHz, p+ = 2.5-57.2 MPa, p(-) = -1.8 to -13.9 MPa, I(SPPA) = 513-22,940 W/cm(2), -6 dB size of 1.6 × 10 mm: lateral × axial) was measured using this approach and then compared with that obtained using a radiation force balance. Similarities were found between each method at acoustic power ranging from 18.2 W to 912 W with an electrical-to-acoustic conversion efficiency of ~42%. The proposed method has advantages of low weight, smaller size, high sensitivity, quick response, high signal-to-noise ratio (especially at low power output), robust performance, and easy operation of HIFU exposimetry measurement.

  1. The IMCA: A field instrument for uranium enrichment measurements

    Energy Technology Data Exchange (ETDEWEB)

    Gardner, G.H.; Koskelo, M.; Moeslinger, M. [Canberra Industries, Meriden, CT (United States); Mayer, R.L. II; McGinnis, B.R. [Lockheed Martin Utility Services, Piketon, OH (United States). Portsmouth Gaseous Diffusion Plant; Wishard, B. [International Atomic Energy Agency, Vienna (Austria)

    1996-12-31

    The IMCA (Inspection Multi-Channel Analyzer) is a portable gamma-ray spectrometer designed to measure the enrichment of uranium either in a laboratory or in the field. The IMCA consists of a Canberra InSpector Multi-Channel Analyzer, sodium iodide or a planar germanium detector, and special application software. The system possesses a high degree of automation. The IMCA uses the uranium enrichment meter principle, and is designed to meet the International Atomic Energy Agency (IAEA) requirements for the verification of enriched uranium materials. The IMCA is available with MGA plutonium isotopic analysis software or MGAU uranium analysis software as well. In this paper, the authors present a detailed description of the hardware and software of the IMCA system, as well as results from preliminary measurements testing compliance of IMCA with IAEA requirements using uranium standards and UF6 cylinders. Measurements performed on UF6 cylinders in the field under variable environmental conditions (temperatures ranging from 0 to 35 C) have shown that good results can be achieved. The enrichment of UF6 contained in the cylinder is determined by using calibration constants generated from an instrument calibration, using traceable uranium oxide standards, performed in the laboratory under controlled environmental conditions. The IMCA software is designed to make the necessary matrix and container corrections to ensure that accurate results are achieved in the field.

  2. Traveling wave tube measurements for low-frequency properties of underwater acoustic materials

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A traveling wave tube measurement technique for measuring acoustic properties of underwater acoustic materials was developed. Water temperature and pressure environments of the ocean can be simulated in a water-filled tube, and the acoustic parameters of samples of underwater acoustic materials are measured in the range of low-frequency. A tested sample is located at central position of the tube. A pair of projectors is separately located at both ends of the tube. Using an active anechoic technique, the sound wave transmitting the tested sample is hardly reflected by the surface of secondary transducer. So the traveling sound field is built up in the tube. By separately calculating the transfer functions of every pair of double hydrophones in the sound fields from the both sides of the sample, its reflection coefficients and transmission coefficients are obtained. In the measurement system, the inside diameter of the tube is Φ208 mm, the working frequency range is from 100 to 4000 Hz, the maximum pressure is 5 MPa. The reflection coefficients and transmission coefficients of a water layer and a stainless steel layer samples are measured actually and calculated theoretically. The results show that the measured values are in good agreement with the values calculated, and the measurement uncertainty is not greater than 1.5 dB.

  3. Producing of Impedance Tube for Measurement of Acoustic Absorption Coefficient of Some Sound Absorber Materials

    Directory of Open Access Journals (Sweden)

    R. Golmohammadi

    2008-04-01

    Full Text Available Introduction & Objective: Noise is one of the most important harmful agents in work environment. In spit of industrial improvements, exposure with over permissible limit of noise is counted as one of the health complication of workers. In Iran, do not exact information of the absorption coefficient of acoustic materials. Iranian manufacturer have not laboratory for measured of sound absorbance of their products, therefore using of sound absorber is limited for noise control in industrial and non industrial constructions. The goal of this study was to design an impedance tube based on pressure method for measurement of the sound absorption coefficient of acoustic materials.Materials & Methods: In this study designing of measuring system and method of calculation of sound absorption based on a available equipment and relatively easy for measurement of the sound absorption coefficient related to ISO10534-1 was performed. Measuring system consist of heavy asbestos tube, a pure tone sound generator, calibrated sound level meter for measuring of some commonly of sound absorber materials was used. Results: In this study sound absorption coefficient of 23 types of available acoustic material in Iran was tested. Reliability of results by three repeat of measurement was tested. Results showed that the standard deviation of sound absorption coefficient of study materials was smaller than .Conclusion: The present study performed a necessary technology of designing and producing of impedance tube for determining of acoustical materials absorption coefficient in Iran.

  4. Measuring Ultrasonic Acoustic Velocity in a Thin Sheet of Graphite Epoxy Composite

    Science.gov (United States)

    2008-01-01

    A method for measuring the acoustic velocity in a thin sheet of a graphite epoxy composite (GEC) material was investigated. This method uses two identical acoustic-emission (AE) sensors, one to transmit and one to receive. The delay time as a function of distance between sensors determines a bulk velocity. A lightweight fixture (balsa wood in the current implementation) provides a consistent method of positioning the sensors, thus providing multiple measurements of the time delay between sensors at different known distances. A linear fit to separation, x, versus delay time, t, will yield an estimate of the velocity from the slope of the line.

  5. Laboratory investigation of a passive acoustic method for measurement of underwater gas seep ebullition.

    Science.gov (United States)

    Greene, Chad A; Wilson, Preston S

    2012-01-01

    Passive acoustic techniques are of interest as a low-power means of quantifying underwater point-source gas ebullition. Toward the development of systems for logging natural seep activity, laboratory experiments were performed that exploited the bubble's Minnaert natural frequency for the measurement of gas flow from a model seep. Results show agreement among acoustic, optical, and gas trap ebullition measurements over the range of emission rates from 0 to 10 bubbles per second. A mathematical model is proposed to account for the real gas behavior of bubbles which cannot be approximated as ideal, such as methane at marine depths exceeding 30 m. PMID:22280731

  6. Spectrometric methods used in the calibration of radiodiagnostic measuring instruments

    Energy Technology Data Exchange (ETDEWEB)

    De Vries, W. [Rijksuniversiteit Utrecht (Netherlands)

    1995-12-01

    Recently a set of parameters for checking the quality of radiation for use in diagnostic radiology was established at the calibration facility of Nederlands Meetinstituut (NMI). The establishment of the radiation quality required re-evaluation of the correction factors for the primary air-kerma standards. Free-air ionisation chambers require several correction factors to measure air-kerma according to its definition. These correction factors were calculated for the NMi free-air chamber by Monte Carlo simulations for monoenergetic photons in the energy range from 10 keV to 320 keV. The actual correction factors follow from weighting these mono-energetic correction factors with the air-kerma spectrum of the photon beam. This paper describes the determination of the photon spectra of the X-ray qualities used for the calibration of dosimetric instruments used in radiodiagnostics. The detector used for these measurements is a planar HPGe-detector, placed in the direct beam of the X-ray machine. To convert the measured pulse height spectrum to the actual photon spectrum corrections must be made for fluorescent photon escape, single and multiple compton scattering inside the detector, and detector efficiency. From the calculated photon spectra a number of parameters of the X-ray beam can be calculated. The calculated first and second half value layer in aluminum and copper are compared with the measured values of these parameters to validate the method of spectrum reconstruction. Moreover the spectrum measurements offer the possibility to calibrate the X-ray generator in terms of maximum high voltage. The maximum photon energy in the spectrum is used as a standard for calibration of kVp-meters.

  7. Developing an instrument to measure effective factors on Clinical Learning

    Science.gov (United States)

    DADGARAN, IDEH; SHIRAZI, MANDANA; MOHAMMADI, AEEN; RAVARI, ALI

    2016-01-01

    Introduction Although nursing students spend a large part of their learning period in the clinical environment, clinical learning has not been perceived by its nature yet. To develop an instrument to measure effective factors on clinical learning in nursing students. Methods This is a mixed methods study performed in 2 steps. First, the researchers defined “clinical learning” in nursing students through qualitative content analysis and designed items of the questionnaire based on semi-structured individual interviews with nursing students. Then, as the second step, psychometric properties of the questionnaire were evaluated using the face validity, content validity, construct validity, and internal consistency evaluated on 227 students from fourth or higher semesters. All the interviews were recorded and transcribed, and then, they were analyzed using Max Qualitative Data Analysis and all of qualitative data were analyzed using SPSS 14. Results To do the study, we constructed the preliminary questionnaire containing 102 expressions. After determination of face and content validities by qualitative and quantitative approaches, the expressions of the questionnaire were reduced to 45. To determine the construct validity, exploratory factor analysis was applied. The results indicated that the maximum variance percentage (40.55%) was defined by the first 3 factors while the rest of the total variance percentage (59.45%) was determined by the other 42 factors. Results of exploratory factor analysis of this questionnaire indicated the presence of 3 instructor-staff, students, and educational related factors. Finally, 41 expressions were kept in 3 factor groups. The α-Cronbach coefficient (0.93) confirmed the high internal consistency of the questionnaire. Conclusion Results indicated that the prepared questionnaire was an efficient instrument in the study of the effective factors on clinical learning as viewed by nursing students since it involves 41 expressions and

  8. Developing an instrument to measure effective factors on clinical learning

    Directory of Open Access Journals (Sweden)

    IDEH DADGARAN

    2016-07-01

    Full Text Available Introduction: Although nursing students spend a large part of their learning period in the clinical environment, clinical learning has not been perceived by its nature yet. To develop an instrument to measure effective factors on clinical learning in nursing students. Methods: This is a mixed methods study performed in 2 steps. First, the researchers defined “clinical learning” in nursing students through qualitative content analysis and designed items of the questionnaire based on semi-structured individual interviews with nursing students. Then, as the second step, psychometric properties of the questionnaire were evaluated using the face validity, content validity, construct validity, and internal consistency evaluated on 227 students from fourth or higher semesters. All the interviews were recorded and transcribed, and then, they were analyzed using Max Qualitative Data Analysis and all of qualitative data were analyzed using SPSS 14. Results: To do the study, we constructed the preliminary questionnaire containing 102 expressions. After determination of face and content validities by qualitative and quantitative approaches, the expressions of the questionnaire were reduced to 45. To determine the construct validity, exploratory factor analysis was applied. The results indicated that the maximum variance percentage (40.55% was defined by the first 3 factors while the rest of the total variance percentage (59.45% was determined by the other 42 factors. Results of exploratory factor analysis of this questionnaire indicated the presence of 3 instructor-staff, students, and educational related factors. Finally, 41 expressions were kept in 3 factor groups. The α-Cronbach coefficient (0.93 confirmed the high internal consistency of the questionnaire. Conclusion: Results indicated that the prepared questionnaire was an efficient instrument in the study of the effective factors on clinical learning as viewed by nursing students since it

  9. Electron density measurement in gas discharge plasmas by optical and acoustic methods

    Science.gov (United States)

    Biagioni, A.; Anania, M. P.; Bellaveglia, M.; Chiadroni, E.; Cianchi, A.; Di Giovenale, D.; Di Pirro, G.; Ferrario, M.; Filippi, F.; Mostacci, A.; Pompili, R.; Shpakov, V.; Vaccarezza, C.; Villa, F.; Zigler, A.

    2016-08-01

    Plasma density represents a very important parameter for both laser wakefield and plasma wakefield acceleration, which use a gas-filled capillary plasma source. Several techniques can be used to measure the plasma density within a capillary discharge, which are mainly based on optical diagnostic methods, as for example the well-known spectroscopic method using the Stark broadening effect. In this work, we introduce a preliminary study on an alternative way to detect the plasma density, based on the shock waves produced by gas discharge in a capillary. Firstly, the measurements of the acoustic spectral content relative to the laser-induced plasmas by a solid target allowed us to understand the main properties of the acoustic waves produced during this kind of plasma generation; afterwards, we have extended such acoustic technique to the capillary plasma source in order to calibrate it by comparison with the stark broadening method.

  10. The influence of the group delay of digital filters on acoustic decay measurements

    DEFF Research Database (Denmark)

    Sobreira-Seoane, Manuel A.; Cabo, David Pérez; Jacobsen, Finn

    2012-01-01

    In this paper the error due to the phase response of digital filters on acoustic decay measurements is analyzed. There are two main sources of errors when an acoustic decay is filtered: the error due to the bandwidth of the filters related to their magnitude response, and the error due...... to their phase response. In this investigation the two components are separated and the phase error analyzed in terms of the group delay of the filters. Linear phase FIR filters and minimum phase IIR filters fulfilling the class 1 requirements of the IEC 61260 standard have been designed, and their errors...... compared. This makes it possible to explain the behavior of the phase error and develop recommendations for the use of each filtering technique. The paper is focused on the filtering techniques covered by current versions of the standards for measurement of acoustic decays and in the evaluation...

  11. Inverse estimation of the acoustic impedance of a porous woven hose from measured transmission coefficients.

    Science.gov (United States)

    Park, Chul-Min; Ih, Jeong-Guon; Nakayama, Yoshio; Takao, Hideo

    2003-01-01

    A porous tube, comprised of a resin-coated woven fabric has recently been used as an effective component for use in intake systems of internal combustion engines to reduce the intake noise. For the prediction of the acoustic performance of an engine intake system with a porous woven hose, the acoustic wall impedance of the hose must be known. However, the accurate measurement of the wall impedance of a porous woven hose is not easy because of its peculiar acoustical and structural characteristics. A new measurement technique is proposed herein, that is valid over the low to mid frequency ranges. The acoustics impedance is inversely estimated from an overdetermined set of measured pressure transmission coefficients for specimens of different lengths and the reflection coefficient of end termination. The method involves only one measurement setup, and, as a result, it is very simple. A variation of the proposed method, an inverse estimation method using one of the four-pole parameters is also proposed. An error sensitivity analysis was performed to investigate the effect of measurement error on the accuracy of the final result. The measured TL for samples with arbitrary lengths and arbitrary porous frequency are in reasonably good agreement with values predicted from curve-fitted impedance data. PMID:12558253

  12. Pupil Alignment Measuring Technique and Alignment Reference for Instruments or Optical Systems

    Science.gov (United States)

    Hagopian, John G.

    2010-01-01

    A technique was created to measure the pupil alignment of instruments in situ by measuring calibrated pupil alignment references (PARs) in instruments. The PAR can also be measured using an alignment telescope or an imaging system. PAR allows the verification of the science instrument (SI) pupil alignment at the integrated science instrument module (ISIM) level of assembly at ambient and cryogenic operating temperature. This will allow verification of the ISIM+SI alignment, and provide feedback to realign the SI if necessary.

  13. Picosecond acoustics in vegetal cells: non invasive in vitro measurements at a sub-cell scale

    Science.gov (United States)

    Audoin, Bertrand; Rossignol, Clément; Chigarev, Nikolay; Ducousso, Mathieu; Forget, Guillaume; Guillemot, Fabien; Durrieu, Marie-Christine

    2010-01-01

    A 100 fs laser pulse passes through a single transparent cell and is absorbed at the surface of a metallic substrate. Picosecond acoustic waves are generated and propagate through the cell in contact with the metal. Interaction of the high frequency acoustic pulse with a probe laser light gives rise to stimulated Brillouin oscillations. The measurements are thus made with lasers for both the opto-acoustic generation and the acousto-optic detection. The technique offers perspectives for single cell imaging. The in plane resolution is limited by the pump and probe spot sizes, i.e ˜1 μm, and the in depth resolution is provided by the acoustic frequencies, typically in the GHz range. The effect of the technique on cell safety is discussed. Experiments achieved in vegetal cells illustrate reproducibility and sensitivity of the measurements. The acoustic responses of cell organelles are significantly different. The results support the potentialities of the hypersonic non invasive technique in the fields of bio-engineering and medicine.

  14. Measurements and computational fluid dynamics predictions of the acoustic impedance of orifices

    Science.gov (United States)

    Su, J.; Rupp, J.; Garmory, A.; Carrotte, J. F.

    2015-09-01

    The response of orifices to incident acoustic waves, which is important for many engineering applications, is investigated with an approach combining both experimental measurements and numerical simulations. This paper presents experimental data on acoustic impedance of orifices, which is subsequently used for validation of a numerical technique developed for the purpose of predicting the acoustic response of a range of geometries with moderate computational cost. Measurements are conducted for orifices with length to diameter ratios, L/D, of 0.5, 5 and 10. The experimental data is obtained for a range of frequencies using a configuration in which a mean (or bias) flow passes from a duct through the test orifices before issuing into a plenum. Acoustic waves are provided by a sound generator on the upstream side of the orifices. Computational fluid dynamics (CFD) calculations of the same configuration have also been performed. These have been undertaken using an unsteady Reynolds averaged Navier-Stokes (URANS) approach with a pressure based compressible formulation with appropriate characteristic based boundary conditions to simulate the correct acoustic behaviour at the boundaries. The CFD predictions are in very good agreement with the experimental data, predicting the correct trend with both frequency and orifice L/D in a way not seen with analytical models. The CFD was also able to successfully predict a negative resistance, and hence a reflection coefficient greater than unity for the L / D = 0.5 case.

  15. Instrumental objective measurement of veal calves carcass colour at slaughterhouse

    Directory of Open Access Journals (Sweden)

    Stefano Vandoni

    2010-01-01

    Full Text Available A total of 6700 veal calves were used to compare the ability of chromameter CR300 in measuring the veal meat colour on-line at slaughterhouse and to develop a prediction equation of colour score based on relationship between instrumental and visual assessments. A total of 5000 carcasses were used to develop equation of prediction while 1700 were used to test it. The meat colour was assessed subjectively in 3 different slaughterhouses by the slaughterhouse’s judges 10h post mortem and objectively by chromameter CR300 45 post mortem on the Rectus abdominis. The prediction equation classified correctly 79% of carcasses and was characterized by an R2 of 78%. Furthermore it has to be underlined that the chroma contributes to the total R2 with a 0.21 partial R2. This data confirmed that chromameter CR300 can be used on-line to measure objectively veal meat colour at the end of the slaughter line.

  16. An Instrument to Measure Aircraft Sulfate Particle Emissions Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Aerodyne is developing a sulfate detection instrument, based on the Tunable Infrared Laser Differential Absorption Spectrophotometer (TILDAS) technology and...

  17. Acoustic measurements of F-4E aircraft operating in hush house, NSN 4920-02-070-2721

    Science.gov (United States)

    Miller, V. R.; Plzak, G. A.; Chinn, J. M.

    1981-09-01

    The primary purpose of this test program was to measure the acoustic environment in the hush house facility located at Kelly Air Force Base, Texas, during operation of the F-4E aircraft to ensure that aircraft structural acoustic design limits were not exceeded. The acoustic measurements showed that sonic fatigue problems are anticipated with the F-4E aircraft aft fuselage structure during operation in the hush house. The measured acoustic levels were less than those measured in an F-4E aircraft water cooled hush house at Hill AFB in the lower frequencies, but were increased over that measured during ground run up on some areas of the aircraft. It was recommended that the acoustic loads measured in this program should be specified in the structural design criteria for aircraft which will be subjected to hush house operation or defining requirements for associated equipment. Recommendations were also made to increase the fatigue life of the aft fuselage.

  18. Acoustic measurements of F100-PW-100 engine operating in hush house NSN 4920-02-070-2721

    Science.gov (United States)

    Miller, V. R.; Plzak, G. A.; Chinn, J. M.

    1981-09-01

    The purpose of this test program was to measure the acoustic environment in the hush house facility located at Kelly AFB Texas during operation of the F100-PW-100 engine to ensure that engine structural acoustic design limits were not exceeded. The acoustic measurements showed that no sonic fatigue problems are anticipated with the F100-PW-100 engine structure during operation in the hush house. The measured acoustic levels were less than those measured in an existing F100-PW-100 engine wet-cooled noise suppressor, but were increased over that measured during operation on an open test stand. It was recommended that the acoustic load increases measured in this program should be specified in the structural design criteria for engines which will be subjected to hush house operation or defining requirements for associated equipment.

  19. A new method and instrument for accurately measuring interval between ultrashort pulses

    Institute of Scientific and Technical Information of China (English)

    Zhonggang Ji; Yuxin Leng; Yunpei Deng; Bin Tang; Haihe Lu; Ruxin Li; Zhizhan Xu

    2005-01-01

    @@ Using second-order autocorrelation conception, a novel method and instrument for accurately measuring interval between two linearly polarized ultrashort pulses with real time were presented. The experiment demonstrated that the measuring method and instrument were simple and accurate (the measurement error < 5 fs). During measuring, there was no moving element resulting in dynamic measurement error.

  20. Direct measurement of the acoustic waves generated by femtosecond filaments in air

    CERN Document Server

    Wahlstrand, J K; Rosenthal, E W; Zahedpour, S; Milchberg, H M

    2014-01-01

    We present direct measurements of the gas acoustic dynamics following interaction of spatial single- and multi-mode 50 fs, 800 nm pulses in air at 10 Hz and 1 kHz repetition rates. Results are in excellent agreement with hydrodynamic simulations. Under no conditions for single filaments do we find on-axis enhancement of gas density; this occurs only with multi-filaments. We also investigate the propagation of probe beams in the gas density profile induced by a single extended filament. We find that light trapping in the expanding annular acoustic wave can create the impression of on-axis guiding in a limited temporal window.

  1. Functions of diffraction correction and analytical solutions in nonlinear acoustic measurement

    CERN Document Server

    Alliès, Laurent; Nadi, M

    2008-01-01

    This paper presents an analytical formulation for correcting the diffraction associated to the second harmonic of an acoustic wave, more compact than that usually used. This new formulation, resulting from an approximation of the correction applied to fundamental, makes it possible to obtain simple solutions for the second harmonic of the average acoustic pressure, but sufficiently precise for measuring the parameter of nonlinearity B/A in a finite amplitude method. Comparison with other expressions requiring numerical integration, show the solutions are precise in the nearfield.

  2. Remote sensing of temperature and wind using acoustic travel-time measurements

    Directory of Open Access Journals (Sweden)

    Manuela Barth

    2013-04-01

    Full Text Available A remote sensing technique to detect area-averaged temperature and flow properties within an area under investigation, utilizing acoustic travel-time measurements, is introduced. This technique uses the dependency of the speed of acoustic signals on the meteorological parameters temperature and wind along the propagation path. The method itself is scalable: It is applicable for investigation areas with an extent of some hundred square metres as well as for small-scale areas in the range of one square metre. Moreover, an arrangement of the acoustic transducers at several height levels makes it possible to determine profiles and gradients of the meteorological quantities. With the help of two examples the potential of this remote sensing technique for simultaneously measuring averaged temperature and flow fields is demonstrated. A comparison of time histories of temperature and wind values derived from acoustic travel-time measurements with point measurements shows a qualitative agreement whereas calculated root-mean-square errors differ for the two example applications. They amount to 1.4 K and 0.3 m/s for transducer distances of 60 m and 0.4 K and 0.2 m/s for transducer distances in the range of one metre.

  3. Numerical simulation and measurements of acoustic transmissions from Heard Island to the equatorial Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    PrasannaKumar, S.; Navelkar, G.S.; Murty, T.V.R.; Somayajulu, Y.K.; Saran, A.K.; Murty, C.S.

    of the Sub Tropical Convergence. Measured acoustic signals, received at the Indian listening station has a signal to noise ratio (SNR) of 20 dB on an average and confirmed their detectability over distances as far as 7000 km. The phase stability...

  4. Continuous measurements of discharge from a horizontal acoustic Doppler current profiler in a tidal river

    NARCIS (Netherlands)

    Hoitink, A.J.F.; Buschman, F.A.; Vermeulen, B.

    2009-01-01

    Acoustic Doppler current profilers (ADCPs) can be mounted horizontally at a river bank, yielding single-depth horizontal array observations of velocity across the river. This paper presents a semideterministic, semistochastic method to obtain continuous measurements of discharge from horizontal ADCP

  5. High accuracy acoustic relative humidity measurement in duct flow with air

    OpenAIRE

    Cees van der Geld; Twan Wernaart; Mart Grooten; Wilhelm van Schaik

    2010-01-01

    An acoustic relative humidity sensor for air-steam mixtures in duct flow is designed and tested. Theory, construction, calibration, considerations on dynamic response and results are presented. The measurement device is capable of measuring line averaged values of gas velocity, temperature and relative humidity (RH) instantaneously, by applying two ultrasonic transducers and an array of four temperature sensors. Measurement ranges are: gas velocity of 0–12 m/s with an error of ±0.13 m/s, temp...

  6. Precision Tiltmeter as a Reference for Slope Measuring Instruments

    International Nuclear Information System (INIS)

    The next generation of synchrotrons and free electron lasers require extremely high-performance x-ray optical systems for proper focusing. The necessary optics cannot be fabricated without the use of precise optical metrology instrumentation. In particular, the Long Trace Profiler (LTP) based on the pencil-beam interferometer is a valuable tool for low-spatial-frequency slope measurement with x-ray optics. The limitations of such a device are set by the amount of systematic errors and noise. A significant improvement of LTP performance was the addition of an optical reference channel, which allowed to partially account for systematic errors associated with wiggling and wobbling of the LTP carriage. However, the optical reference is affected by changing optical path length, non-homogeneous optics, and air turbulence. In the present work, we experimentally investigate the questions related to the use of a precision tiltmeter as a reference channel. Dependence of the tiltmeter performance on horizontal acceleration, temperature drift, motion regime, and kinematical scheme of the translation stage has been investigated. It is shown that at an appropriate experimental arrangement, the tiltmeter provides a slope reference for the LTP system with accuracy on the level of 0.1 (micro)rad (rms)

  7. A new instrument for high statistics measurement of photomultiplier characteristics

    Science.gov (United States)

    Mollo, C. M.; Bozza, C.; Chiarusi, T.; Costa, M.; Di Capua, F.; Kulikovskiy, V.; Mele, R.; Migliozzi, P.; Pellegrino, C.; Riccobene, G.; Vivolo, D.

    2016-08-01

    Since the early days of experimental particle physics photomultipliers (PMTs) have played an important role in the detector design. Thanks to their capability of fast photon counting, PMTs are extensively used in the new-generation of astroparticle physics experiments, such as air, ice and water Cherenkov detectors. Small size PMTs (<= 3 inches diameter) show little sensitivity to the Earth magnetic field, small transit time, stable transit time spread; the price per photocathode area is less comparing to the one for the large area PMTs, typically used so far in such applications. Together with developments and reduced price of multichannel electronics, the use of PMTs of 3-inches or smaller diameter is a promising option even for nowadays large volume detectors. In this paper we report on the design and performance of a new instrument for mass characterisation of PMTs (from 1 inch to 3 inches size), capable to calibrate hundreds of PMTs per day and provide measurements of dark counts, signal amplitude, late-, delayed-, pre- and after-pulses, transit time and transit time spread.

  8. Verifax: Biometric instruments measuring neuromuscular disorders/performance impairments

    Science.gov (United States)

    Morgenthaler, George W.; Shrairman, Ruth; Landau, Alexander

    1998-01-01

    VeriFax, founded in 1990 by Dr. Ruth Shrairman and Mr. Alex Landau, began operations with the aim of developing a biometric tool for the verification of signatures from a distance. In the course of developing this VeriFax Autograph technology, two other related applications for the technologies under development at VeriFax became apparent. The first application was in the use of biometric measurements as clinical monitoring tools for physicians investigating neuromuscular diseases (embodied in VeriFax's Neuroskill technology). The second application was to evaluate persons with critical skills (e.g., airline pilots, bus drivers) for physical and mental performance impairments caused by stress, physiological disorders, alcohol, drug abuse, etc. (represented by VeriFax's Impairoscope prototype instrument). This last application raised the possibility of using a space-qualified Impairoscope variant to evaluate astronaut performance with respect to the impacts of stress, fatigue, excessive workload, build-up of toxic chemicals within the space habitat, etc. The three applications of VeriFax's patented technology are accomplished by application-specific modifications of the customized VeriFax software. Strong commercial market potentials exist for all three VeriFax technology applications, and market progress will be presented in more detail below.

  9. Precision Tiltmeter as a Reference for Slope MeasuringInstruments

    Energy Technology Data Exchange (ETDEWEB)

    Kirschman, Jonathan L.; Domning, Edward E.; Morrison, Gregory Y.; Smith, Brian V.; Yashchuk, Valeriy V.

    2007-08-01

    The next generation of synchrotrons and free electron lasers require extremely high-performance x-ray optical systems for proper focusing. The necessary optics cannot be fabricated without the use of precise optical metrology instrumentation. In particular, the Long Trace Profiler (LTP) based on the pencil-beam interferometer is a valuable tool for low-spatial-frequency slope measurement with x-ray optics. The limitations of such a device are set by the amount of systematic errors and noise. A significant improvement of LTP performance was the addition of an optical reference channel, which allowed to partially account for systematic errors associated with wiggling and wobbling of the LTP carriage. However, the optical reference is affected by changing optical path length, non-homogeneous optics, and air turbulence. In the present work, we experimentally investigate the questions related to the use of a precision tiltmeter as a reference channel. Dependence of the tiltmeter performance on horizontal acceleration, temperature drift, motion regime, and kinematical scheme of the translation stage has been investigated. It is shown that at an appropriate experimental arrangement, the tiltmeter provides a slope reference for the LTP system with accuracy on the level of 0.1 {micro}rad (rms).

  10. A new instrument for high statistics measurement of photomultiplier characteristics

    CERN Document Server

    Bozza, C; Costa, M; Di Capua, F; Kulikovskiy, V; Mele, R; Migliozzi, P; Mollo, C M; Pellegrino, C; Riccobene, G; Vivolo, D

    2016-01-01

    Since the early days of experimental particle physics photomultipliers (PMTs) have played an important role in the detector design. Thanks to their capability of fast photon counting, PMTs are extensively used in the new-generation of astroparticle physics experiments, such as air, ice and water Cherenkov detectors. The use of PMTs of 3-inches or smaller diameter was made possible thanks to the capability of building detectors with large photocathode area distributed in a sustainable number of channels. Small size PMTs ($\\leq$ 3-inches) show little sensitivity to the Earth magnetic field, small transit time, stable transit time spread; the price per photocathode area is less comparing to the one for the large area PMTs, typically used so far in such applications. In this paper we report on the design and performance of a new instrument for mass characterisation of PMTs (from 1-inch to 3-inch size), capable to calibrate hundreds of PMTs per day and provide measurements of dark counts, signal amplitude, late-, ...

  11. Accuracy of measurement of acoustic rhinometry applied to small experimental animals

    DEFF Research Database (Denmark)

    Kaise, Toshihiko; Ukai, Kotara; Pedersen, Ole Finn;

    1999-01-01

    Nasal obstruction is one of the major symptoms of allergic rhinitis. In the study of the mechanism of nasal obstruction, experiments on animal are useful. In adult humans, acoustic rhinometry has been used to evaluate nasal obstruction by determining nasal cavity dimensions in terms of cross......-sectional areas as a function of the distance from the nostril. We modified the equipment used on humans to assess dimensions of nasal airway geometry of small experimental animals. The purpose of this study was to investigate the accuracy of measurement of the modified acoustic rhinometry applied to small...... was 73.7 ± 20.0% of actual volume. The actual volume was estimated by impression material instilled into the nasal cavity of the animals (1M volume), and volume determined by acoustic rhinometry significantly correlated with 1M volume. Furthermore, there was a significant negative correlation between...

  12. Acoustic Reflex Measurements in Normal, Cochlear, and Retrocochlear Lesions -Part1

    Directory of Open Access Journals (Sweden)

    Navid Shahnaz

    1992-04-01

    Full Text Available The cut off points of 90th percentile of acoustic reflex thresholds were determined in the normal and sensory hearing loss.All subjects had measurable hearing(ANSI-1969≤110 dBHL in three frequencies of 500,1000 and 2000Hz.While hearing loss was more than 55dB, The cut off point was higher in studies that NR responses was included.In cases that hearing loss was less than 75dB, 90th percentile can be used in diganosis of retrochochlear lesions.Since Acoustic reflexes are absent in both mentioned pathologies in greater amount of hearing loss,It would be less efficient in diffrential diganisis of cochlear and retrochochlear lesions to use acoustic reflex thresholds under the mentioned circumstances.

  13. A measure of acoustic noise generated from transcranial magnetic stimulation coils.

    Science.gov (United States)

    Dhamne, Sameer C; Kothare, Raveena S; Yu, Camilla; Hsieh, Tsung-Hsun; Anastasio, Elana M; Oberman, Lindsay; Pascual-Leone, Alvaro; Rotenberg, Alexander

    2014-01-01

    The intensity of sound emanating from the discharge of magnetic coils used in repetitive transcranial magnetic stimulation (rTMS) can potentially cause acoustic trauma. Per Occupational Safety and Health Administration (OSHA) standards for safety of noise exposure, hearing protection is recommended beyond restricted levels of noise and time limits. We measured the sound pressure levels (SPLs) from four rTMS coils with the goal of assessing if the acoustic artifact levels are of sufficient amplitude to warrant protection from acoustic trauma per OSHA standards. We studied the SPLs at two frequencies (5 and 10 Hz), three machine outputs (MO) (60, 80 and 100%), and two distances from the coil (5 and 10 cm). We found that the SPLs were louder at closer proximity from the coil and directly dependent on the MO. We also found that in all studied conditions, SPLs were lower than the OSHA permissible thresholds for short (8 h) exposure.

  14. INSTRUMENTS MEASURING PERCEIVED RACISM/RACIAL DISCRIMINATION: REVIEW AND CRITIQUE OF FACTOR ANALYTIC TECHNIQUES

    OpenAIRE

    Atkins, Rahshida

    2014-01-01

    Several compendiums of instruments that measure perceived racism and/or discrimination are present in the literature. Other works have reviewed the psychometric properties of these instruments in terms of validity and reliability and have indicated if the instrument was factor analyzed. However, little attention has been given to the quality of the factor analysis performed. The aim of this study was to evaluate the exploratory factor analyses done on instruments measuring perceived racism/ra...

  15. Proceedings of the OECD/CSNI specialist meeting on advanced instrumentation and measurement techniques

    International Nuclear Information System (INIS)

    In the last few years, tremendous advances in the local instrumentation technology for two-phase flow have been accomplished by the applications of new sensor techniques, optical or beam methods and electronic technology. The detailed measurements gave new insight to the true nature of local mechanisms of interfacial transfer between phases, interfacial structure and two-phase flow turbulent transfers. These new developments indicate that more accurate and reliable two-phase flow models can be obtained, if focused experiments are designed and performed by utilizing this advanced instrumentation. The purpose of this Specialist Meeting on Advanced Instrumentation and Measurement Techniques was to review the recent instrumentation developments and the relation between thermal-hydraulic codes and instrumentation capabilities. Four specific objectives were identified for this meeting: bring together international experts on instrumentation, experiments, and modeling; review recent developments in multiphase flow instrumentation; discuss the relation between modeling needs and instrumentation capabilities, and discuss future directions for instrumentation development, modeling, and experiments

  16. Coupling thermogravimetric and acoustic emission measurements: its application to study the inhibition of catalytic coke deposition

    Energy Technology Data Exchange (ETDEWEB)

    Ropital, Francois; Dascotte, Philippe; Marchand, Pierre [Institut Francais du Petrole, 1 Avenue Bois Preau, 92952 Rueil-Malmaison (France); Faure, Thierry; Lenain, Jean-Claude; Proust, Alain [Euro Physical Acoustics, 27 Rue Magellan, 94373 Sucy-en-Brie Cedex (France)

    2004-07-01

    In order to improve the knowledge on the high temperature behaviour of metallic materials, the coupling of several in situ physical analysis methods is a promising way. For this purpose a thermogravimetric balance has been equipped with a specific acoustic emission device in order to continuously measure the mass variation of the corrosion sample and the acoustic emission transient under experimental conditions of temperature and gas phase compositions that are representative of the industrial environments. The catalytic coke deposition condition that is a major problem for the refinery and petrochemical industries, has been studied with such a device. The carbon deposition on reactor walls can induce localised disruption in the process such as heat-transfer reduction and pressure drops. To prevent these perturbations, proper selections of the metallurgical or internal coating compositions of the equipment, or the injection of accurate amount of inhibitors have to be decided. The feasibility of the coupling at high temperature of thermogravimetric and acoustic emission has been demonstrated. This new technique has been applied to study the inhibition of the catalytic coke deposition on pure iron by sulphur additives in the temperature range of 650 deg. C and under different mixed atmospheres of hydrocarbon and hydrogen contents. Good correlation has been obtained between the coking rates measured by thermogravimetric measurements and the intensities of the acoustic emission parameters. (authors)

  17. Numerical investigation and electro-acoustic modeling of measurement methods for the in-duct acoustical source parameters

    Science.gov (United States)

    Jang, Seung-Ho; Ih, Jeong-Guon

    2003-02-01

    It is known that the direct method yields different results from the indirect (or load) method in measuring the in-duct acoustic source parameters of fluid machines. The load method usually comes up with a negative source resistance, although a fairly accurate prediction of radiated noise can be obtained from any method. This study is focused on the effect of the time-varying nature of fluid machines on the output results of two typical measurement methods. For this purpose, a simplified fluid machine consisting of a reservoir, a valve, and an exhaust pipe is considered as representing a typical periodic, time-varying system and the measurement situations are simulated by using the method of characteristics. The equivalent circuits for such simulations are also analyzed by considering the system as having a linear time-varying source. It is found that the results from the load method are quite sensitive to the change of cylinder pressure or valve profile, in contrast to those from the direct method. In the load method, the source admittance turns out to be predominantly dependent on the valve admittance at the calculation frequency as well as the valve and load admittances at other frequencies. In the direct method, however, the source resistance is always positive and the source admittance depends mainly upon the zeroth order of valve admittance.

  18. Numerical and experimental investigation of a low-frequency measurement technique: differential acoustic resonance spectroscopy

    Science.gov (United States)

    Yin, Hanjun; Zhao, Jianguo; Tang, Genyang; Ma, Xiaoyi; Wang, Shangxu

    2016-06-01

    Differential acoustic resonance spectroscopy (DARS) has been developed to determine the elastic properties of saturated rocks within the kHz frequency range. This laboratory technique is based on considerations from perturbation theory, wherein the resonance frequencies of the resonant cavity with and without a perturbation sample are used to estimate the acoustic properties of the test sample. In order to better understand the operating mechanism of DARS and therefore optimize the procedure, it is important to develop an accurate and efficient numerical model. Accordingly, this study presents a new multiphysics model by coupling together considerations from acoustics, solid mechanics, and electrostatics. The numerical results reveal that the newly developed model can successfully simulate the acoustic pressure field at different resonance modes, and that it can accurately reflect the measurement process. Based on the understanding of the DARS system afforded by the numerical simulation, we refine the system configuration by utilizing cavities of different lengths and appropriate radii to broaden the frequency bandwidth and ensure testing accuracy. Four synthetic samples are measured to test the performance of the optimized DARS system, in conjunction with ultrasonic and static measurements. For nonporous samples, the estimated bulk moduli are shown to be independent of the different measurement methods (i.e. DARS or ultrasonic techniques). In contrast, for sealed porous samples, the differences in bulk moduli between the low- and high-frequency techniques can be clearly observed; this discrepancy is attributed to frequency dispersion. In summary, the optimized DARS system with an extended frequency range of 500-2000 Hz demonstrates considerable utility in investigating the frequency dependence of the acoustic properties of reservoir rocks.

  19. Measuring acoustic energy density in microchannel acoustophoresis using a simple and rapid light-intensity method

    DEFF Research Database (Denmark)

    Barnkob, Rune; Iranmanesh, Ida; Wiklund, Martin;

    2012-01-01

    We present a simple and rapid method for measuring the acoustic energy density in microchannel acoustophoresis based on light-intensity measurements of a suspension of particles. The method relies on the assumption that each particle in the suspension undergoes single-particle acoustophoresis. It......, and it is an attractive alternative to particle tracking and particle image velocimetry for quantifying acoustophoretic performance in microchannels........ It is validated by the single-particle tracking method, and we show by proper re-scaling that the re-scaled light intensity plotted versus re-scaled time falls on a universal curve. The method allows for analysis of moderate-resolution images in the concentration range encountered in typical experiments......We present a simple and rapid method for measuring the acoustic energy density in microchannel acoustophoresis based on light-intensity measurements of a suspension of particles. The method relies on the assumption that each particle in the suspension undergoes single-particle acoustophoresis...

  20. Method based on broadband compressed pulse superposition to measure properties of underwater acoustic materials

    Institute of Scientific and Technical Information of China (English)

    LI Shui; MIAO Rongxing

    2001-01-01

    A method is proposed for the measurements of the performances of underwater acoustic finite sized large area material samples in a free field by using broadband pulse compression technique. As the result of which, the low-frequency cutoff of the standard tests is obviously reduced, and the broadband measurements are also realized. The experimental system provides measurements of complex reflection and transmission coefficients at continuous frequency points. From the data one can obtain the following acoustic parameters: echo reduction and insertion loss, absorption and attenuation coefficients, etc. The measurements are performed for two actual panels with the size 1 m×1 m in the frequency range from 2-20 kHz.

  1. Acoustic measurement of overall voice quality in sustained vowels and continuous speech

    OpenAIRE

    Maryn, Youri

    2010-01-01

    Measurement of dysphonia severity involves auditory-perceptual evaluations and acoustic analyses of sound waves. Meta-analysis of proportional associations between these two methods showed that many popular perturbation metrics and noise-to-harmonics and others ratios do not yield reasonable results. However, this meta-analysis demonstrated that the validity of specific autocorrelation- and cepstrum-based measures was much more convincing, and appointed ‘smoothed cepstral peak prominence’ as ...

  2. Coherent Combination of Baryon Acoustic Oscillation Statistics and Peculiar Velocity Measurements from Redshift Survey

    OpenAIRE

    Song, Yong-Seon

    2010-01-01

    New statistical method is proposed to coherently combine Baryon Acoustic Oscillation statistics (BAO) and peculiar velocity measurements exploiting decomposed density-density and velocity-velocity spectra in real space from the observed redshift distortions in redshift space, 1) to achieve stronger dark energy constraints, \\sigma(w)=0.06 and \\sigma(w_a)=0.20, which are enhanced from BAO or velocity measurements alone, and 2) to cross-check consistency of dark energy constraints from two diffe...

  3. Measurement of the space-time correlation function of thermal acoustic radiation

    Science.gov (United States)

    Passechnik, V. I.; Anosov, A. A.; Barabanenkov, Yu. N.; Sel'Sky, A. G.

    2003-09-01

    The space-time correlation function of thermal acoustic radiation pressure is measured for a stationary heated source (a narrow plasticine plate). The correlation dependence is obtained by the multiplication of two signals shifted in time with respect to each other and measured by two receivers. The dependence exhibits an oscillating behavior and changes sign when the source is displaced by half the spatial period of the correlation function.

  4. Acoustic Measurement of Surface Wave Damping by a Meniscus.

    Science.gov (United States)

    Michel, Guillaume; Pétrélis, François; Fauve, Stéphan

    2016-04-29

    We investigate the reflection of gravity-capillary surface waves by a plane vertical barrier. The size of the meniscus is found to strongly affect reflection: the energy of the reflected wave with a pinned contact line is around twice the one corresponding to a fully developed meniscus. To perform these measurements, a new experimental setup similar to an acousto-optic modulator is developed and offers a simple way to measure the amplitude, frequency and direction of propagation of surface waves. PMID:27176523

  5. Development of an Instrument to Measure Medical Students' Attitudes toward People with Disabilities

    Science.gov (United States)

    Symons, Andrew B.; Fish, Reva; McGuigan, Denise; Fox, Jeffery; Akl, Elie A.

    2012-01-01

    As curricula to improve medical students' attitudes toward people with disabilities are developed, instruments are needed to guide the process and evaluate effectiveness. The authors developed an instrument to measure medical students' attitudes toward people with disabilities. A pilot instrument with 30 items in four sections was administered to…

  6. Exploration of Instruments Measuring Concepts of Graduateness in a Research University Context

    Science.gov (United States)

    Steur, J. M.; Jansen, E. P. W. A.; Hofman, W. H. A.

    2011-01-01

    This article considers the appropriateness of international instruments to measure the separate concepts of graduateness for a research university context. The four concepts of graduateness--reflective thinking, scholarship, moral citizenship and lifelong learning--are operationalized using five existing instruments. These instruments were…

  7. Measuring Instrument Constructs of Return Factors for Green Office Building Investments Variables Using Rasch Measurement Model

    Directory of Open Access Journals (Sweden)

    Isa Mona

    2016-01-01

    Full Text Available This paper is a preliminary study on rationalising green office building investments in Malaysia. The aim of this paper is attempt to introduce the application of Rasch measurement model analysis to determine the validity and reliability of each construct in the questionnaire. In achieving this objective, a questionnaire survey was developed consists of 6 sections and a total of 106 responses were received from various investors who own and lease office buildings in Kuala Lumpur. The Rasch Measurement analysis is used to measure the quality control of item constructs in the instrument by measuring the specific objectivity within the same dimension, to reduce ambiguous measures, and a realistic estimation of precision and implicit quality. The Rasch analysis consists of the summary statistics, item unidimensionality and item measures. A result shows the items and respondent (person reliability is at 0.91 and 0.95 respectively.

  8. Acoustic method for measuring the sound speed of gases over small path lengths.

    Science.gov (United States)

    Olfert, J S; Checkel, M D; Koch, C R

    2007-05-01

    Acoustic "phase shift" methods have been used in the past to accurately measure the sound speed of gases. In this work, a phase shift method for measuring the sound speed of gases over small path lengths is presented. We have called this method the discrete acoustic wave and phase detection (DAWPD) method. Experimental results show that the DAWPD method gives accurate (+/-3.2 ms) and predictable measurements that closely match theory. The sources of uncertainty in the DAWPD method are examined and it is found that ultrasonic reflections and changes in the frequency ratio of the transducers (the ratio of driving frequency to resonant frequency) can be major sources of error. Experimentally, it is shown how these sources of uncertainty can be minimized. PMID:17552851

  9. Measurements of Acoustic Properties of Porous and Granular Materials and Application to Vibration Control

    Science.gov (United States)

    Park, Junhong; Palumbo, Daniel L.

    2004-01-01

    For application of porous and granular materials to vibro-acoustic controls, a finite dynamic strength of the solid component (frame) is an important design factor. The primary goal of this study was to investigate structural vibration damping through this frame wave propagation for various poroelastic materials. A measurement method to investigate the vibration characteristics of the frame was proposed. The measured properties were found to follow closely the characteristics of the viscoelastic materials - the dynamic modulus increased with frequency and the degree of the frequency dependence was determined by its loss factor. The dynamic stiffness of hollow cylindrical beams containing porous and granular materials as damping treatment was measured also. The data were used to extract the damping materials characteristics using the Rayleigh-Ritz method. The results suggested that the acoustic structure interaction between the frame and the structure enhances the dissipation of the vibration energy significantly.

  10. Flow acoustics modelling and implications for ultrasonic flow measurement based on the transit-time method.

    Science.gov (United States)

    Willatzen, M

    2004-05-01

    A comparison between three mathematical models frequently used in flow acoustics is presented and discussed with respect to ultrasonic flow-meter performance based on the transit-time method. The flow-meter spoolpiece geometry is assumed to be a cylindrical pipe. Semi-analytical calculations employing the Frobenius power series expansion method are shown for the cases of a constant-, linear-, parabolic-, and cubic-flow profiles although the Frobenius method presented can be applied to any smooth flow profile. It is shown that the so-called deviation of measurement, often used as a measure of the flow-meter accuracy, is strongly dependent on the acoustic mode excited and the flow profile. Furthermore, differences with respect to deviation of measurement results exist among the three mathematical models analyzed. PMID:15110538

  11. Trends in instrumentation for environmental radiation measurements at Los Alamos Scientific Laboratory

    International Nuclear Information System (INIS)

    Recent instruments developed to fulfill radiation monitoring needs at Los Alamos Scientific Laboratory are described. Laboratory instruments that measure tritium gas effluents alone, or in the presence of activated air from D-T fusion reactors are discussed. Fully portable systems for gamma, x-ray, and alpha analyses in the field are described. Also included are descriptions of survey instruments that measure low levels of transuranic contaminants and that measure pulsed-neutron dose rates

  12. Early-age acoustic emission measurements in hydrating cement paste: Evidence for cavitation during solidification due to self-desiccation

    DEFF Research Database (Denmark)

    Lura, Pietro; Couch, J.; Jensen, Ole Mejlhede;

    2009-01-01

    . According to these experimental results, the acoustic emission measured around setting time was attributed to cavitation events occurring in the pores of the cement paste due to self-desiccation. This paper shows how acoustic emission might be used to indicate the time when the fluid–solid transition occurs...

  13. Examination of four different instruments for measuring the blood lactate concentration

    OpenAIRE

    Medbø, Jon Ingulf; Mamen, Asgeir; Olsen, Ole Holt; Evertsen, Frank

    2000-01-01

    ABSTRACT There is incomplete information on the performance of different instruments used to measure the blood lactate concentration. We have therefore examined instruments from Yellow Springs Instruments (YSI 23L and YSI 1500), and three cheaper and simpler instruments: Dr. Lange’s LP8+, Lactate Pro from Arkray, KDK, and Accusport from Boehringer Mannheim. First a number of blood samples were analysed by standard enzymatic photofluorometry (our control method) and in additi...

  14. Acoustic input impedance of the avian inner ear measured in ostrich (Struthio camelus).

    Science.gov (United States)

    Muyshondt, Pieter G G; Aerts, Peter; Dirckx, Joris J J

    2016-09-01

    In both mammals and birds, the mechanical behavior of the middle ear structures is affected by the mechanical impedance of the inner ear. In this study, the aim was to quantify the acoustic impedance of the avian inner ear in the ostrich, which allows us to determine the effect on columellar vibrations and middle ear power flow in future studies. To determine the inner ear impedance, vibrations of the columella were measured for both the quasi-static and acoustic stimulus frequencies. In the frequency range of 0.3-4 kHz, we used electromagnetic stimulation of the ossicle and a laser Doppler vibrometer to measure the vibration response. At low frequencies, harmonic displacements were imposed on the columella using piezo stimulation and the resulting force response was measured with a force sensor. From these measurement data, the acoustic impedance of the inner ear could be determined. A simple RLC model in series of the impedance measurements resulted in a stiffness reactance of KIE = 0.20·10(12) Pa/m³, an inertial impedance of MIE = 0.652·10(6) Pa s(2)/m³, and a resistance of RIE = 1.57·10(9) Pa s/m. We found that values of the inner ear impedance in the ostrich are one to two orders in magnitude smaller than what is found in mammal ears. PMID:27473506

  15. Development of a Self-Rating instrument to Measure Team Situation Awareness

    NARCIS (Netherlands)

    Schraagen, J.M.C.; Koning, L. de; Hof, T.; Dongen, K. van

    2010-01-01

    The goal of this paper is to describe the development of an instrument to measure team situation awareness (TSA). Individual team member SA may or may not be shared through communication processes with other team members. Most existing instruments do not measure these processes but measure TSA as a

  16. Acoustic containerless experiment system: A non-contact surface tension measurement

    Science.gov (United States)

    Elleman, D. D.; Wang, T. G.; Barmatz, M.

    1988-01-01

    The Acoustic Containerless Experiment System (ACES) was flown on STS 41-B in February 1984 and was scheduled to be reflown in 1986. The primary experiment that was to be conducted with the ACES module was the containerless melting and processing of a fluoride glass sample. A second experiment that was to be conducted was the verification of a non-contact surface tension measurement technique using the molten glass sample. The ACES module consisted of a three-axis acoustic positioning module that was inside an electric furnace capable of heating the system above the melting temperature of the sample. The acoustic module is able to hold the sample with acoustic forces in the center of the chamber and, in addition, has the capability of applying a modulating force on the sample along one axis of the chamber so that the molten sample or liquid drop could be driven into one of its normal oscillation modes. The acoustic module could also be adjusted so that it could place a torque on the molten drop and cause the drop to rotate. In the ACES, a modulating frequency was applied to the drop and swept through a range of frequencies that would include the n = 2 mode. A maximum amplitude of the drop oscillation would indicate when resonance was reached and from that data the surface tension could be calculated. For large viscosity samples, a second technique for measuring surface tension was developed. The results of the ACES experiment and some of the problems encountered during the actual flight of the experiment will be discussed.

  17. Fusion of acoustic measurements with video surveillance for estuarine threat detection

    Science.gov (United States)

    Bunin, Barry; Sutin, Alexander; Kamberov, George; Roh, Heui-Seol; Luczynski, Bart; Burlick, Matt

    2008-04-01

    Stevens Institute of Technology has established a research laboratory environment in support of the U.S. Navy in the area of Anti-Terrorism and Force Protection. Called the Maritime Security Laboratory, or MSL, it provides the capabilities of experimental research to enable development of novel methods of threat detection in the realistic environment of the Hudson River Estuary. In MSL, this is done through a multi-modal interdisciplinary approach. In this paper, underwater acoustic measurements and video surveillance are combined. Stevens' researchers have developed a specialized prototype video system to identify, video-capture, and map surface ships in a sector of the estuary. The combination of acoustic noise with video data for different kinds of ships in Hudson River enabled estimation of sound attenuation in a wide frequency band. Also, it enabled the collection of a noise library of various ships that can be used for ship classification by passive acoustic methods. Acoustics and video can be used to determine a ship's position. This knowledge can be used for ship noise suppression in hydrophone arrays in underwater threat detection. Preliminary experimental results of position determination are presented in the paper.

  18. Shallow-water acoustic tomography from angle measurements instead of travel-time measurements.

    Science.gov (United States)

    Aulanier, Florian; Nicolas, Barbara; Mars, Jérôme I; Roux, Philippe; Brossier, Romain

    2013-10-01

    For shallow-water waveguides and mid-frequency broadband acoustic signals, ocean acoustic tomography (OAT) is based on the multi-path aspect of wave propagation. Using arrays in emission and reception and advanced array processing, every acoustic arrival can be isolated and matched to an eigenray that is defined not only by its travel time but also by its launch and reception angles. Classically, OAT uses travel-time variations to retrieve sound-speed perturbations; this assumes very accurate source-to-receiver clock synchronization. This letter uses numerical simulations to demonstrate that launch-and-reception-angle tomography gives similar results to travel-time tomography without the same requirement for high-precision synchronization.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-01-30

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

  20. In-situ optical and acoustical measurements of the buoyant cyanobacterium p. Rubescens: spatial and temporal distribution patterns.

    Directory of Open Access Journals (Sweden)

    Hilmar Hofmann

    Full Text Available Optical (fluorescence and acoustic in-situ techniques were tested in their ability to measure the spatial and temporal distribution of plankton in freshwater ecosystems with special emphasis on the harmful and buoyant cyanobacterium P. rubescens. Fluorescence was measured with the multi-spectral FluoroProbe (Moldaenke FluoroProbe, MFP and a Seapoint Chlorophyll Fluorometer (SCF. In-situ measurements of the acoustic backscatter strength (ABS were conducted with three different acoustic devices covering multiple acoustic frequencies (614 kHz ADCP, 2 MHz ADP, and 6 MHz ADV. The MFP provides a fast and reliable technique to measure fluorescence at different wavelengths in situ, which allows discriminating between P. rubescens and other phytoplankton species. All three acoustic devices are sensitive to P. rubescens even if other scatterers, e.g., zooplankton or suspended sediment, are present in the water column, because P. rubescens containing gas vesicles has a strong density difference and hence acoustic contrast to the ambient water and other scatterers. After calibration, the combination of optical and acoustical measurements not only allows qualitative and quantitative observation of P. rubescens, but also distinction between P. rubescens, other phytoplankton, and zooplankton. As the measuring devices can sample in situ at high rates they enable assessment of plankton distributions at high temporal (minutes and spatial (decimeters resolution or covering large temporal (seasonal and spatial (basin scale scales.

  1. Self-oscillation acoustic system destined to measurement of stresses in mass rocks

    CERN Document Server

    Kwasniewski, Janusz; Dominik, Ireneusz; Dorobczynski, Lech

    2011-01-01

    The paper presents an electronic self-oscillation acoustic system (SAS) destined to measure of stresses variations in the elastic media. The system consists of piezoelectric detector, amplifier-limiter, pass-band filter, piezoelectric exciter and the frequency meter. The mass rock plays a role of delaying element, in which variations in stresses causing the variations of acoustic wave velocity of propagation, and successive variation in frequency of oscillations generated by system. The laboratory test permitted to estimate variations in frequency caused by variations in stresses of elastic medium. The principles of selection of frequency and other parameters of the electronic system in application to stresses measurement in condition of the mine were presented.

  2. Study on the High Precision Acoustic Measurement Techniques for Determining Temperature Field Around Seafloor Hydrothermal Vent

    Institute of Scientific and Technical Information of China (English)

    CAI Yong; FAN Wei; ZHOU Yan; FU Xian-qiao; FANG Hui; JIN Tao

    2012-01-01

    This paper presents the basis of acoustic method used for temperature field measurement of seafloor hydrothermal vent and two techniques of the parabolic interpolation and the bending compensation of propagation paths of acoustic signal are introduced.Experimental research is performed to exactly rebuild the temperature field around hot springs on the floor of Qiezishan Lake,Yunnan,China.The accuracy of the travel time estimation has been improved based on the aforementioned technique and method.At the same time,by comparison of the results of temperature field with different means,the max absolute error,the maximum relative error and the root mean square error are given.It shows that the technique and the method presented in the paper can be applied to the temperature field measurement detector around the seafloor hydrothermal vent.It also has a good accuracy.

  3. Extending the turbidity record: making additional use of continuous data from turbidity, acoustic-Doppler, and laser diffraction instruments and suspended-sediment samples in the Colorado River in Grand Canyon

    Science.gov (United States)

    Voichick, Nicholas; Topping, David J.

    2014-01-01

    Turbidity is a measure of the scattering and absorption of light in water, which in rivers is primarily caused by particles, usually sediment, suspended in the water. Turbidity varies significantly with differences in the design of the instrument measuring turbidity, a point that is illustrated in this study by side-by-side comparisons of two different models of instruments. Turbidity also varies with changes in the physical parameters of the particles in the water, such as concentration, grain size, grain shape, and color. A turbidity instrument that is commonly used for continuous monitoring of rivers has a light source in the near-infrared range (860±30 nanometers) and a detector oriented 90 degrees from the incident light path. This type of optical turbidity instrument has a limited measurement range (depending on pathlength) that is unable to capture the high turbidity levels of rivers that carry high suspended-sediment loads. The Colorado River in Grand Canyon is one such river, in which approximately 60 percent of the range in suspended-sediment concentration during the study period had unmeasurable turbidity using this type of optical instrument. Although some optical turbidimeters using backscatter or other techniques can measure higher concentrations of suspended sediment than the models used in this study, the maximum turbidity measurable using these other turbidimeters may still be exceeded in conditions of especially high concentrations of suspended silt and clay. In Grand Canyon, the existing optical turbidity instruments remain in use in part to provide consistency over time as new techniques are investigated. As a result, during these periods of high suspended-sediment concentration, turbidity values that could not be measured with the optical turbidity instruments were instead estimated from concurrent acoustic attenuation data collected using side-looking acoustic-Doppler profiler (ADP) instruments. Extending the turbidity record to the full

  4. Local Measurement of Electron Density and Temperature in High Temperature Laser Plasma Using the Ion-Acoustic Dispersion

    Energy Technology Data Exchange (ETDEWEB)

    Froula, D H; Davis, P; Ross, S; Meezan, N; Divol, L; Price, D; Glenzer, S H; Rousseaux, C

    2005-09-20

    The dispersion of ion-acoustic fluctuations has been measured using a novel technique that employs multiple color Thomson-scattering diagnostics to measure the frequency spectrum for two separate thermal ion-acoustic fluctuations with significantly different wave vectors. The plasma fluctuations are shown to become dispersive with increasing electron temperature. We demonstrate that this technique allows a time resolved local measurement of electron density and temperature in inertial confinement fusion plasmas.

  5. Constraints on dark energy models from radial baryon acoustic scale measurements

    OpenAIRE

    Samushia, Lado; Ratra, Bharat

    2008-01-01

    We use the radial baryon acoustic oscillation (BAO) measurements of Gaztanaga et al. (2008) to constrain parameters of dark energy models. These constraints are comparable with constraints from other "non-radial" BAO data. The radial BAO data are consistent with the time-independent cosmological constant model but do not rule out time-varying dark energy. When we combine radial BAO and the Kowalski et al. (2008) Union type Ia supernova data we get very tight constraints on dark energy.

  6. Application of Wavelet Packet Analysis to the Measurement of the Baryon Acoustic Oscillation

    Science.gov (United States)

    Kadowaki, Kevin; Garcia, Noel; Ford, Taurean; Pando, Jesus; SDSS-FAST Collaboration

    2016-03-01

    We develop a method of wavelet packet analysis to measure the Baryon Acoustic Oscillation (BAO) peak and apply this method to the CMASS galaxy catalog from the SDSS Baryon Oscillation Spectroscopic Survey (BOSS) collaboration. We compare our results to a fiducial ?CDM flat cosmological model and detect a BAO signature in the power spectrum comparable to the previous consensus results of the BOSS collaboration. We find DA = 1365rd /rd , fid at z = . 54 . Member ID Forthcoming.

  7. Breath air measurement using wide-band frequency tuning IR laser photo-acoustic spectroscopy

    Science.gov (United States)

    Kistenev, Yury V.; Borisov, Alexey V.; Kuzmin, Dmitry A.; Bulanova, Anna A.; Boyko, Andrey A.; Kostyukova, Nadezhda Y.; Karapuzikov, Alexey A.

    2016-03-01

    The results of measuring of biomarkers in breath air of patients with broncho-pulmonary diseases using wide-band frequency tuning IR laser photo-acoustic spectroscopy and the methods of data mining are presented. We will discuss experimental equipment and various methods of intellectual analysis of the experimental spectra in context of above task. The work was carried out with partial financial support of the FCPIR contract No 14.578.21.0082 (ID RFMEFI57814X0082).

  8. Measuring a caring culture in hospitals: a systematic review of instruments

    OpenAIRE

    Hesselink, G.J.; Kuis, E.; Pijnenburg, M.A.; Wollersheim, H.C.

    2013-01-01

    OBJECTIVE: To identify instruments or components of instruments that aim to measure aspects of a caring culture-shared beliefs, norms and values that direct professionals and managers to act caring in hospitals, and to evaluate their psychometric properties. DESIGN: Systematic review. DATA SOURCES: PubMed, CINAHL, EMBASE, PsychInfo, Web of Science and the International bibliography of the Social Sciences. STUDY SELECTION: Peer-reviewed articles describing (components of) instruments measuring...

  9. Measuring Health Literacy Regarding Infectious Respiratory Diseases: A New Skills-Based Instrument

    OpenAIRE

    Sun, Xinying; Chen, Juan; Shi, Yuhui; Zeng, Qingqi; Wei, Nanfang; Xie, Ruiqian; Chang, Chun; Du, Weijing

    2013-01-01

    Background There is no special instrument to measure skills-based health literacy where it concerns infectious respiratory diseases. This study aimed to explore and evaluate a new skills-based instrument on health literacy regarding respiratory infectious diseases. Methods This instrument was designed to measure not only an individual’s reading and numeracy ability, but also their oral communication ability and their ability to use the internet to seek information. Sixteen stimuli materials w...

  10. Evaluation of instrumental methods for the measurement of yellowcake emissions

    International Nuclear Information System (INIS)

    An evaluation of current sampling and analysis methods used for monitoring yellowcake emissions from uranium mill exhausts was performed by Pacific Northwest Laboratory. The representativeness of sampling once per quarter was felt to be questionable. A more representative sample would be obtained by a continuous sampling system. The analysis could be performed by relatively newer instrumental methods. Direct-spectrometric and isotopically excited x-ray fluorecence instrumental analysis methods were evaluated. Because of a redirection in funding, the evaluation was not completed in terms of identifying instrumental interferences and field testing of the chosen methods. However, in light of readily available technology, a preferred method for sampling and analysis of yellowcake from uranium mill exhausts is proposed. This method would sample the exhaust stacks continuously using a continuous, automatic, isokinetic stack sampler with deposition of the exhaust gas particulates onto filter paper. The deposited particulates would then be analyzed by x-ray fluorescence using 57Co as an excitation source. It is also recommended that a paper-tape sampler that houses an isotopic excitation source and detector be interfaced to a continuous stack sampler. This system would require evaluation and field testing after development. 16 references, 6 figures, 3 tables

  11. GRAAL - Griggs-type Apparatus equipped with Acoustics in the Laboratory: a new instrument to explore the rheology of rocks at high pressure

    Science.gov (United States)

    Schubnel, A.; Champallier, R.; Precigout, J.; Pinquier, Y.; Ferrand, T. P.; Incel, S.; Hilairet, N.; Labrousse, L.; Renner, J.; Green, H. W., II; Stunitz, H.; Jolivet, L.

    2015-12-01

    Two new generation solid-medium Griggs-type apparatus have been set up at the Laboratoire de Géologie of ENS PARIS, and the Institut des Sciences de la Terre d'Orléans (ISTO). These new set-ups allow to perform controlled rock deformation experiments on large volume samples, up to 5 GPa and 1300°C. Careful pressure - stress calibration will be performed (using D-DIA and/or Paterson-type experiments as standards), strain-stress-pressure will be measured using modern techniques and state of the art salt assemblies. Focusing on rheology, the pressure vessel at ISTO has been designed in a goal of deforming large sample diameter (8 mm) at confining pressure of up to 3 GPa. Thanks to this large sample size, this new vessel will allow to explore the microstructures related to the deformation processes occurring at pressures of the deep lithosphere and in subduction zones. In this new apparatus, we moreover included a room below the pressure vessel in order to develop a basal load cell as close as possible to the sample. This new design, in progress, aims at significantly improving the accuracy of stress measurements in the Griggs-type apparatus. The ultimate goal is to set up a new technique able to routinely quantify the rheology of natural rocks between 0.5 and 5 GPa. Although fundamental to document the rheology of the lithosphere, such a technique is still missing in rock mechanics. Focusing on the evolution of physical and mechanical properties during mineral phase transformations, the vessel at ENS is equipped with continuous acoustic emission (AE) multi-sensor monitoring in order to "listen" to the sample during deformation. Indeed, these continuous recordings enable to detect regular AE like signals during dynamic crack propagation, as well as non-impulsive signals, which might be instrumental to identify laboratory analogs to non-volcanic tremor and low frequency earthquake signals. P and S elastic wave velocities will also be measured contemporaneously during

  12. The Development, Validity, and Reliability of a Psychometric Instrument Measuring Competencies in Student Affairs

    Science.gov (United States)

    Sriram, Rishi

    2014-01-01

    The study of competencies in student affairs began more than 4 decades ago, but no instrument currently exists to measure competencies broadly. This study builds upon previous research by developing an instrument to measure student affairs competencies. Results not only validate the competencies espoused by NASPA and ACPA, but also suggest adding…

  13. Development and validation of an instrument to measure perceived neighbourhood quality in Taiwan

    OpenAIRE

    Yang, M; Shih, C.; Kawachi, I

    2002-01-01

    Study objectives: Social epidemiologists have hypothesised that neighbourhood quality may exert an important contextual influence on mental and physical health. However, validated instruments do not exist for measuring neighbourhood quality in Taiwan. A self reported instrument to measure perceived neighbourhood quality in Taiwan was developed and tested.

  14. Development of the instrument IMAQE-Food to measure effectiveness of quality management

    NARCIS (Netherlands)

    Spiegel, van der M.; Luning, P.A.; Ziggers, G.W.; Jongen, W.M.F.

    2005-01-01

    Purpose - Manufacturers use several quality assurance systems to assure quality. However, their effectiveness cannot be assessed because an instrument does not exist. This article is based on a study that was set up to identify performance measurement indicators of an instrument that measures effect

  15. Development of a Measurement Instrument to Assess Students' Electrolyte Conceptual Understanding

    Science.gov (United States)

    Lu, Shanshan; Bi, Hualin

    2016-01-01

    To assess students' conceptual understanding levels and diagnose alternative frameworks of the electrolyte concept, a measurement instrument was developed using the Rasch model. This paper reports the use of the measurement instrument to assess 559 students from grade 10 to grade 12 in two cities. The results provided both diagnostic and summative…

  16. Acoustic measurement method of the volume flux of a seafloor hydrothermal plume

    Science.gov (United States)

    Xu, G.; Jackson, D. R.; Bemis, K. G.; Rona, P. A.

    2011-12-01

    Measuring fluxes (volume, chemical, heat, etc.) of the deep sea hydrothermal vents has been a crucial but challenging task faced by the scientific community since the discovery of the vent systems. However, the great depths and complexities of the hydrothermal vents make traditional sampling methods laborious and almost daunting missions. Furthermore, the samples, in most cases both sparse in space and sporadic in time, are hardly enough to provide a result with moderate uncertainty. In September 2010, our Cabled Observatory Vent Imaging Sonar System (COVIS, http://vizlab.rutgers.edu/AcoustImag/covis.html) was connected to the Neptune Canada underwater ocean observatory network (http://www.neptunecanada.ca) at the Main Endeavour vent field on the Endeavour segment of the Juan de Fuca Ridge. During the experiment, the COVIS system produced 3D images of the buoyant plume discharged from the vent complex Grotto by measuring the back-scattering intensity of the acoustic signal. Building on the methodology developed in our previous work, the vertical flow velocity of the plume is estimated from the Doppler shift of the acoustic signal using geometric correction to compensate for the ambient horizontal currents. A Gaussian distribution curve is fitted to the horizontal back-scattering intensity profile to determine the back-scattering intensity at the boundary of the plume. Such a boundary value is used as the threshold in a window function for separating the plume from background signal. Finally, the volume flux is obtained by integrating the resulting 2D vertical velocity profile over the horizontal cross-section of the plume. In this presentation, we discuss preliminary results from the COVIS experiment. In addition, several alternative approaches are applied to determination of the accuracy of the estimated plume vertical velocity in the absence of direct measurements. First, the results from our previous experiment (conducted in 2000 at the same vent complex using a

  17. Gene Expression Measurement Module (GEMM) - A Fully Automated, Miniaturized Instrument for Measuring Gene Expression in Space

    Science.gov (United States)

    Pohorille, Andrew; Peyvan, Kia; Karouia, Fathi; Ricco, Antonio

    2012-01-01

    The capability to measure gene expression on board spacecraft opens the door to a large number of high-value experiments on the influence of the space environment on biological systems. For example, measurements of gene expression will help us to understand adaptation of terrestrial life to conditions beyond the planet of origin, identify deleterious effects of the space environment on a wide range of organisms from microbes to humans, develop effective countermeasures against these effects, and determine the metabolic bases of microbial pathogenicity and drug resistance. These and other applications hold significant potential for discoveries in space biology, biotechnology, and medicine. Supported by funding from the NASA Astrobiology Science and Technology Instrument Development Program, we are developing a fully automated, miniaturized, integrated fluidic system for small spacecraft capable of in-situ measurement of expression of several hundreds of microbial genes from multiple samples. The instrument will be capable of (1) lysing cell walls of bacteria sampled from cultures grown in space, (2) extracting and purifying RNA released from cells, (3) hybridizing the RNA on a microarray and (4) providing readout of the microarray signal, all in a single microfluidics cartridge. The device is suitable for deployment on nanosatellite platforms developed by NASA Ames' Small Spacecraft Division. To meet space and other technical constraints imposed by these platforms, a number of technical innovations are being implemented. The integration and end-to-end technological and biological validation of the instrument are carried out using as a model the photosynthetic bacterium Synechococcus elongatus, known for its remarkable metabolic diversity and resilience to adverse conditions. Each step in the measurement process-lysis, nucleic acid extraction, purification, and hybridization to an array-is assessed through comparison of the results obtained using the instrument with

  18. Acoustic measurements for the combustion diagnosis of diesel engines fuelled with biodiesels

    Science.gov (United States)

    Zhen, Dong; Wang, Tie; Gu, Fengshou; Tesfa, Belachew; Ball, Andrew

    2013-05-01

    In this paper, an experimental investigation was carried out on the combustion process of a compression ignition (CI) engine running with biodiesel blends under steady state operating conditions. The effects of biodiesel on the combustion process and engine dynamics were analysed for non-intrusive combustion diagnosis based on a four-cylinder, four-stroke, direct injection and turbocharged diesel engine. The signals of vibration, acoustic and in-cylinder pressure were measured simultaneously to find their inter-connection for diagnostic feature extraction. It was found that the sound energy level increases with the increase of engine load and speed, and the sound characteristics are closely correlated with the variation of in-cylinder pressure and combustion process. The continuous wavelet transform (CWT) was employed to analyse the non-stationary nature of engine noise in a higher frequency range. Before the wavelet analysis, time synchronous average (TSA) was used to enhance the signal-to-noise ratio (SNR) of the acoustic signal by suppressing the components which are asynchronous. Based on the root mean square (RMS) values of CWT coefficients, the effects of biodiesel fractions and operating conditions (speed and load) on combustion process and engine dynamics were investigated. The result leads to the potential of airborne acoustic measurements and analysis for engine condition monitoring and fuel quality evaluation.

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

    International Nuclear Information System (INIS)

    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.)

  20. A method of estimating inspiratory flow rate and volume from an inhaler using acoustic measurements

    International Nuclear Information System (INIS)

    Inhalers are devices employed to deliver medication to the airways in the treatment of respiratory diseases such as asthma and chronic obstructive pulmonary disease. A dry powder inhaler (DPI) is a breath actuated inhaler that delivers medication in dry powder form. When used correctly, DPIs improve patients' clinical outcomes. However, some patients are unable to reach the peak inspiratory flow rate (PIFR) necessary to fully extract the medication. Presently clinicians have no reliable method of objectively measuring PIFR in inhalers. In this study, we propose a novel method of estimating PIFR and also the inspiratory capacity (IC) of patients' inhalations from a commonly used DPI, using acoustic measurements. With a recording device, the acoustic signal of 15 healthy subjects using a DPI over a range of varying PIFR and IC values was obtained. Temporal and spectral signal analysis revealed that the inhalation signal contains sufficient information that can be employed to estimate PIFR and IC. It was found that the average power (Pave) in the frequency band 300–600 Hz had the strongest correlation with PIFR (R2 = 0.9079), while the power in the same frequency band was also highly correlated with IC (R2 = 0.9245). This study has several clinical implications as it demonstrates the feasibility of using acoustics to objectively monitor inhaler use. (paper)

  1. Linear and Nonlinear Acoustic Measurements of Buried Landmines: Detection Schemes Near Resonance

    Science.gov (United States)

    Sabatier, James M.

    2003-03-01

    Measurements of the acoustic impedance of an anti-personnel and anti-tank plastic, blast-hardened landmines reveal resonances in the frequency range between 100 and 1000 Hz. The top surface resonances are due to its complicated mechanical structure vibrating in air. The lowest mode results from the blast hardened design of the landmine. Typically, a portion or cavity of the landmine is designed to absorb the shock from an explosion that is intended to detonate the landmine but still allow the landmine to trigger its explosive device when a slow steady pressure is applied. The mechanical design of the blast hardened aspects results in a high Q simple harmonic oscillator resonance of the top surface. At higher frequencies the top surface behaves like thin circular plate acoustic modes. When these landmines are buried in soils, the modes are mass loaded. Resonances from measurements of the normal component of the acoustically induced soil surface particle velocity are used for detection schemes. Since the interface between the top plate and the soil responds to pressure fluctuations nonlinearly, characteristics of landmines, the soil, and the interface are rich in nonlinear physics and allow for new methods of landmine detection not previously exploited.

  2. [Value of electronic measuring instruments for optimizing functional TMJ diagnosis].

    Science.gov (United States)

    Zimmer, B; Keese, E; Kubein-Meesenburg, D

    1989-09-01

    In order to get additional information about the significance of electronic axiographic recordings in TMJ-diagnosis, 34 patients, who showed 47 clicking TMJs, were examined by use of an electronic axiographic instrument (SAS-system). The frequency of the detected findings emphasize the value of electronic axiographic devices for differential diagnosis. In detail the following conclusions could be drawn: examination of different types of movement is recommended because clicking must not exist in all types, recording in more than one plane is necessary in order to detect the (prevailing) plane of dislocation, a magnification of tracings provides addition information concerning different types of clicking.

  3. Matching simulations with measured acoustic data from Roman Theatres using the ODEON programme

    DEFF Research Database (Denmark)

    Nielsen, Martin Lisa; Rindel, Jens Holger; Christensen, Claus Lynge;

    2005-01-01

    In the context of the ERATO research project (“identification, Evaluation and Revival of the Acoustical heritage of ancient Theatres and Odea”) funded by the European Union, acoustic measurements as well as computer simulations have been carried out in the Aspendos Theatre, Turkey and in the south...... theatre in Jerash, Jordan. The simulations are made with the ODEON software, for which a new frequency-dependent diffraction method is currently being developed for implementation in future versions of the programme. In order to make the virtual restorations of these ancient Roman theatres as correct....... The paper describes this exercise, the calculation parameters in ODEON that were adjusted in the process, and the extent to which it was successful....

  4. INSTRUMENTATION DEVELOPMENT, MEASUREMENT AND PERFORMANCE EVALUATION OF ENVIRONMENTAL TECHNOLOGIES

    Energy Technology Data Exchange (ETDEWEB)

    Unknown

    2001-12-31

    Many DOE applications would significantly benefit from the availability of robust and convenient instrumentation for trace-level actinide monitoring and analysis. This project focuses on developing new instrumentation for on-line or at-line monitoring for actinides with isotopic analysis capability. In addition, analytical protocols for a novel concentration method for actinides are being investigated. These efforts focus on demonstrating these techniques using uranium. In addition to its value in the analytical laboratory, the combination of a simple concentration technique with a robust isotopic monitor could provide a powerful method for addressing a number of outstanding DOE needs. Potential applications include monitors for waste water and sewage treatment systems influent and effluent, and the ability to determine the isotopic content of transuranic species in low-activity waste fractions for waste classification and product acceptance. For example, the need for improved monitoring for uranium, plutonium, and americium in treatment plant influent is clearly identified in need RF-ER11. With some additional sample pretreatment, such technology could also impact materials characterization needs by providing on-site isotopic analyses in a system that is smaller and significantly less complex than inductively coupled plasma mass spectrometry (ICP-MS).

  5. A review of instruments to measure interprofessional team-based primary care.

    Science.gov (United States)

    Shoemaker, Sarah J; Parchman, Michael L; Fuda, Kathleen Kerwin; Schaefer, Judith; Levin, Jessica; Hunt, Meaghan; Ricciardi, Richard

    2016-07-01

    Interprofessional team-based care is increasingly regarded as an important feature of delivery systems redesigned to provide more efficient and higher quality care, including primary care. Measurement of the functioning of such teams might enable improvement of team effectiveness and could facilitate research on team-based primary care. Our aims were to develop a conceptual framework of high-functioning primary care teams to identify and review instruments that measure the constructs identified in the framework, and to create a searchable, web-based atlas of such instruments (available at: http://primarycaremeasures.ahrq.gov/team-based-care/ ). Our conceptual framework was developed from existing frameworks, the teamwork literature, and expert input. The framework is based on an Input-Mediator-Output model and includes 12 constructs to which we mapped both instruments as a whole, and individual instrument items. Instruments were also reviewed for relevance to measuring team-based care, and characterized. Instruments were identified from peer-reviewed and grey literature, measure databases, and expert input. From nearly 200 instruments initially identified, we found 48 to be relevant to measuring team-based primary care. The majority of instruments were surveys (n = 44), and the remainder (n = 4) were observational checklists. Most instruments had been developed/tested in healthcare settings (n = 30) and addressed multiple constructs, most commonly communication (n = 42), heedful interrelating (n = 42), respectful interactions (n = 40), and shared explicit goals (n = 37). The majority of instruments had some reliability testing (n = 39) and over half included validity testing (n = 29). Currently available instruments offer promise to researchers and practitioners to assess teams' performance, but additional work is needed to adapt these instruments for primary care settings.

  6. A review of instruments to measure interprofessional team-based primary care.

    Science.gov (United States)

    Shoemaker, Sarah J; Parchman, Michael L; Fuda, Kathleen Kerwin; Schaefer, Judith; Levin, Jessica; Hunt, Meaghan; Ricciardi, Richard

    2016-07-01

    Interprofessional team-based care is increasingly regarded as an important feature of delivery systems redesigned to provide more efficient and higher quality care, including primary care. Measurement of the functioning of such teams might enable improvement of team effectiveness and could facilitate research on team-based primary care. Our aims were to develop a conceptual framework of high-functioning primary care teams to identify and review instruments that measure the constructs identified in the framework, and to create a searchable, web-based atlas of such instruments (available at: http://primarycaremeasures.ahrq.gov/team-based-care/ ). Our conceptual framework was developed from existing frameworks, the teamwork literature, and expert input. The framework is based on an Input-Mediator-Output model and includes 12 constructs to which we mapped both instruments as a whole, and individual instrument items. Instruments were also reviewed for relevance to measuring team-based care, and characterized. Instruments were identified from peer-reviewed and grey literature, measure databases, and expert input. From nearly 200 instruments initially identified, we found 48 to be relevant to measuring team-based primary care. The majority of instruments were surveys (n = 44), and the remainder (n = 4) were observational checklists. Most instruments had been developed/tested in healthcare settings (n = 30) and addressed multiple constructs, most commonly communication (n = 42), heedful interrelating (n = 42), respectful interactions (n = 40), and shared explicit goals (n = 37). The majority of instruments had some reliability testing (n = 39) and over half included validity testing (n = 29). Currently available instruments offer promise to researchers and practitioners to assess teams' performance, but additional work is needed to adapt these instruments for primary care settings. PMID:27212003

  7. Profile measurements and data from the 2011 Optics, Acoustics, and Stress In Situ (OASIS) project at the Martha's Vineyard Coastal Observatory

    Science.gov (United States)

    Sherwood, Christopher R.; Dickhudt, Patrick J.; Martini, Marinna A.; Montgomery, Ellyn T.; Boss, Emmanuel S.

    2012-01-01

    This report documents data collected by the U.S. Geological Survey (USGS) for the Coastal Model Applications and Field Measurements project under the auspices of the U.S. Navy Office of Naval Research Optics, Acoustics, and Stress In Situ (OASIS) Project. The objective of the measurements was to relate optical and acoustic properties of suspended particles to changes in particle size, concentration, and vertical distribution in the bottom boundary layer near the seafloor caused by wave- and current-induced stresses. This information on the physics of particle resuspension and aggregation and light penetration and water clarity will help improve models of sediment transport, benthic primary productivity, and underwater visibility. There is well-established technology for acoustic profiling, but optical profiles are more difficult to obtain because of the rapid attenuation of light in water. A specially modified tripod with a moving arm was designed to solve this problem by moving instruments vertically in the bottom boundary layer, between the bottom and about 2 meters above the seafloor. The profiling arm was designed, built, and tested during spring and summer 2011 by a team of USGS scientists, engineers, and technicians. To accommodate power requirements and the large data files recorded by some of the optical instruments, the tripod was connected via underwater cable to the Martha's Vineyard Coastal Observatory, operated by the Woods Hole Oceanographic Institution (WHOI). This afforded real-time Internet communication with the embedded computers aboard the tripod. Instruments were mounted on the profiling arm, and additional instruments were mounted elsewhere on the tripod and nearby on the seafloor. The tripod and a small mooring for a profiling current meter were deployed on September 17, 2011, at the Martha's Vineyard Coastal Observatory 12-meter-deep underwater node about 2 kilometers south of Martha's Vineyard, Massachusetts. Divers assisted in the

  8. Laser Doppler instrument measures fluid velocity without reference beam

    Science.gov (United States)

    Bourquin, K. R.; Shigemoto, F. H.

    1971-01-01

    Fluid velocity is measured by focusing laser beam on moving fluid and measuring Doppler shift in frequency which results when radiation is scattered by particles either originally present or deliberately injected into moving fluid.

  9. A new instrument to measure gaseous nitrous acid (HONO) in the atmosphere.

    Science.gov (United States)

    Heland, J; Kleefmann, J; Kurtenbach, R; Wiesen, P

    2001-08-01

    A new in situ instrument (LOPAP: long path absorption photometer) to measure gaseous nitrous acid (HONO) using wet chemical sampling and photometric detection has been developed. This instrument is aimed to overcome the known problems with current HONO measurement techniques and was designed to be a cheap, sensitive, compact, and continuouslyworking HONO monitorfor ambient air measurements in the troposphere or for measurements of higher concentrations e.g. in smog chambers, in exhaust gases, and in indoor environments. Laboratory investigations were carried outto characterize the instrument components with respect to collection efficiency, optimum dye formation, optimum detection, and interfering species. Detection limits ranging from approximately 3 to 50 pptV have been obtained with response times from 4 to 1.5 min, respectively, using different instrument parameters. The accuracy of the measurements is in the range between +/-(10-15)%. The validation of the instrument was performed in the laboratory for HONO concentrations of 3 and 30 ppbV using ion chromatography and with a DOAS (differential optical absorption spectrometer) instrument in a large outdoor smog chamber in the range from 0.1 to 20 ppbV. The deviations were well within the errors of the measurements; however, when comparing the data with the DOAS instrument systematically higher values were found with the LOPAP instrument. PMID:11506004

  10. The Problem of the Instrument Stabilization During Hydrographic Measurements

    Directory of Open Access Journals (Sweden)

    Felski Andrzej

    2016-06-01

    Full Text Available Performing any measurement on watercraft is connected with many additional difficulties caused by the sea-environment. The most important is the problem of spatial stabilization of measurement systems, which are usually fastened to craft body. As soon as usually these measurement are executed during the move of the craft additional question is the accuracy of execution the planed trajectory.

  11. The influence of phonetic context and formant measurement location on acoustic vowel space

    Science.gov (United States)

    Turner, Greg S.; Hutchings, David T.; Sylvester, Betsy; Weismer, Gary

    2003-04-01

    One way of depicting vowel production is by describing vowels within an F1/F2 acoustic vowel space. This acoustic measure illustrates the dispersion of F1 and F2 values at a specific moment in time (e.g., the temporal midpoint of a vowel) for the vowels of a given language. This measure has recently been used to portray vowel production in individuals with communication disorders such as dysarthria and is moderately related to the severity of the speech disorder. Studies aimed at identifying influential factors effecting measurement stability of vowel space have yet to be completed. The focus of the present study is to evaluate the influence of phonetic context and spectral measurement location on vowel space in a group of neurologically normal American English speakers. For this study, vowel space was defined in terms of the dispersion of the four corner vowels produced within a CVC syllable frame, where C includes six stop consonants in all possible combinations with each vowel. Spectral measures were made at the midpoint and formant extremes of the vowels. A discussion will focus on individual and group variation in vowel space as a function of phonetic context and temporal measurement location.

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

    Directory of Open Access Journals (Sweden)

    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.

  13. Near-field acoustic holography with sound pressure and particle velocity measurements

    DEFF Research Database (Denmark)

    Fernandez Grande, Efren

    of particle velocity measurements and combined pressure-velocity measurements in NAH, the relation between the near-field and the far-field radiation from sound sources via the supersonic acoustic intensity, and finally, the reconstruction of sound fields using rigid spherical microphone arrays. Measurement...... of the particle velocity has notable potential in NAH, and furthermore, combined measurement of sound pressure and particle velocity opens a new range of possibilities that are examined in this study. On this basis, sound field separation methods have been studied, and a new measurement principle based on double...... layer measurements of the particle velocity has been proposed. Also, the relation between near-field and far-field radiation from sound sources has been examined using the concept of the supersonic intensity. The calculation of this quantity has been extended to other holographic methods, and studied...

  14. Measurement of pipe wall thinning by ultra acoustic resonance technique using optical fiber

    International Nuclear Information System (INIS)

    This is the novel system for Pipe Wall Thickness measurement which is combined EAMT(Electro Magnetic Acoustic Transducer) and Optical Fiber Sensor. The conventional ultrasonic thickness meter is using in pipe wall thickness measurement. However, it is necessary to remove a heat insulator from pipe line. A characteristic of this novel system is that it is possible to measure without removing a heat insulator and on-line monitoring, because of measurement probe is attached between pipe surface and heat insulator. As a result of measured with this system, we could measure 30 mm thickness of carbon and stainless steel at the maximum and pipe specimen of elbow shape. Heat-resistant characteristic confirmed at 200 degrees C until about 7000 hours. (author)

  15. Multibeam volume acoustic backscatter imagery and reverberation measurements in the northeastern Gulf of Mexico

    Science.gov (United States)

    Gallaudet, Timothy C.; deMoustier, Christian P.

    2002-08-01

    Multibeam volume acoustic backscatter imagery and reverberation measurements are derived from data collected in 200-m-deep waters in the northeastern Gulf of Mexico, with the Toroidal Volume Search Sonar (TVSS), a 68-kHz cylindrical sonar operated by the U.S. Navy's Coastal System Station. The TVSS's 360-degree vertical imaging plane allows simultaneous identification of multiple volume scattering sources and their discrimination from backscatter at the sea surface or the seafloor. This imaging capability is used to construct a three-dimensional representation of a pelagic fish school near the bottom. Scattering layers imaged in the mixed layer and upper thermocline are attributed to assemblages of epipelagic zooplankton. The fine scale patchiness of these scatterers is assessed with the two-dimensional variance spectra of vertical volume scattering strength images in the upper and middle water column. Mean volume reverberation levels exhibit a vertical directionality which is attributed to the volume scattering layers. Boundary echo sidelobe interference and reverberation is shown to be the major limitation in obtaining bioacoustic data with the TVSS. Because net tow and trawl samples were not collected with the acoustic data, the analysis presented is based upon comparison to previous biologic surveys in the northeastern Gulf of Mexico and reference to the bioacoustic literature. copyright 2002 Acoustical Society of America.

  16. Novel Instrument to Measure Aerosol Fluorescence, Absorption, and Scattering Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Picarro, Inc proposes to develop the first cavity ringdown spectroscopy (CRDS) system to measure fluorescence, absorption, and scattering properties of atmospheric...

  17. A Cabled Acoustic Telemetry System for Detecting and Tracking Juvenile Salmon: Part 1. Engineering Design and Instrumentation

    Directory of Open Access Journals (Sweden)

    M. Brad Eppard

    2011-05-01

    Full Text Available In 2001 the U.S. Army Corps of Engineers, Portland District (OR, USA, started developing the Juvenile Salmon Acoustic Telemetry System, a nonproprietary sensing technology, to meet the needs for monitoring the survival of juvenile salmonids through eight large hydroelectric facilities within the Federal Columbia River Power System (FCRPS. Initial development focused on coded acoustic microtransmitters and autonomous receivers that could be deployed in open reaches of the river for detection of the juvenile salmonids implanted with microtransmitters as they passed the autonomous receiver arrays. In 2006, the Pacific Northwest National Laboratory began the development of an acoustic receiver system for deployment at hydropower facilities (cabled receiver for detecting fish tagged with microtransmitters as well as tracking them in two or three dimensions for determining route of passage and behavior as the fish passed at the facility. The additional information on route of passage, combined with survival estimates, is used by the dam operators and managers to make structural and operational changes at the hydropower facilities to improve survival of fish as they pass the facilities through the FCRPS.

  18. Laser-Based Instrument Measures Propagation Of Cracks

    Science.gov (United States)

    Lee, Rupert U.; Cox, Robert B.; Youngquist, Robert C.; Sentz, John T.; Rose, Kenneth A.

    1995-01-01

    Report describes use of commerical laser displacement meter to measure propagation of cracks in stainless-steel specimens in stress tests in corrosive (salt-spray) environment. Measurements directed toward determining time from beginning of each test until onset of propagation of crack.

  19. Aeroacoustics of Musical Instruments

    NARCIS (Netherlands)

    Fabre, B.; Gilbert, J.; Hirschberg, A.; Pelorson, X.

    2012-01-01

    We are interested in the quality of sound produced by musical instruments and their playability. In wind instruments, a hydrodynamic source of sound is coupled to an acoustic resonator. Linear acoustics can predict the pitch of an instrument. This can significantly reduce the trial-and-error process

  20. High impulse voltage and current measurement techniques fundamentals, measuring instruments, measuring methods

    CERN Document Server

    Schon, Klaus

    2013-01-01

    Equipment to be installed in electric power-transmission and distribution systems must pass acceptance tests with standardized high-voltage or high-current test impulses which simulate the stress on the insulation caused by external lightning discharges and switching operations in the grid. High impulse voltages and currents are also used in many other fields of science and engineering for various applications. Therefore, precise impulse-measurement techniques are necessary, either to prevent an over- or understressing of the insulation or to guarantee the effectiveness and quality of the application. The book deals with: principal generator circuits for generating high-voltage and high-current impulses measuring systems and their calibration according to IEC 60060 and IEC 62475 methods of estimating uncertainties of measurement mathematical and experimental basis for characterizing the transfer behavior of spatially extended systems used for measuring fast transients. This book is intended for engineers and ...

  1. Equipping the community to measure children's height: the reliability of portable instruments.

    OpenAIRE

    Voss, L D; Bailey, B J

    1994-01-01

    OBJECTIVE--To compare (1) the reliability of two expensive and two inexpensive measuring instruments, suitable for use in the community and (2) the reliability of experienced compared with inexperienced observers. DESIGN--(1) Ten children aged 5-12 years were each measured three times blindly, and in random order, by two experienced observers using four different portable instruments. (2) Four groups of four children aged 5-11 years were each measured three times blindly, and in random order ...

  2. The effect of the instrument function on Doppler ion temperature measurements

    Science.gov (United States)

    Lawson, K. D.; Peacock, N. J.

    1988-09-01

    The measurement of ion temperatures from the Doopler broadening of spectral lines is discussed. Calculations are used to show that the shape of the instrument function of the spectrometer can have a significant effect on the measured value, even when the broadening is large (˜10X) compared with the half-width of the instrument function. The discussion is illustrated by the optical example of measurements made using an XUV grating spectrometer.

  3. A NEW INSTRUMENT FOR MEASURING LOCAL MOISTURE CONTENTS IN MOIST POROUS MEDIA

    Institute of Scientific and Technical Information of China (English)

    HAN Ji-tian; WANG Ji-hao; GUI Ke-ting; SHI Ming-heng

    2005-01-01

    A new instrument was developed for measuring the local moisture content in moist porous media based on the needle-type capacitance sensor and single-chip microprocessor technique. The working principle, the structure and characteristics of the hardware and software of the instrument were presented. The dynamic response characteristics and reliability of the instrument were experimentally determined. As an example, the instrument was employed to measure the heat and mass transport properties of a moist porous material. The experimental results show that the instrument can be used for measuring the local moisture content in moist porous media and would be an effective tool for determining the heat and mass transport properties in moist porous media.

  4. An instrument for measuring abrasive water jet diameter

    OpenAIRE

    Junkar, Mihael; Lebar, Andrej; Orbanić, Henri

    2015-01-01

    In order to improve the accuracy of abrasive water jet (AW) machining the precise value of the jet diameter has to be known. Because of an aggressive environment caused by high velocity abrasive grains, the diameter is not easily measured. That is why a measuring device consisting of a load cell and a wear resistant probe was developed. The device measures the force of the jet while it passes over the edge of the probe. If the feed rate of the jet is constant and the time needed for jet to pa...

  5. Angular measurement of acoustic reflection coefficients by the inversion of V(z, t) data with high frequency time-resolved acoustic microscopy

    Science.gov (United States)

    Chen, Jian; Bai, Xiaolong; Yang, Keji; Ju, Bing-Feng

    2012-01-01

    For inspection of mechanical properties and integrity of critical components such as integrated circuits or composite materials by acoustic methodology, it is imperative to evaluate their acoustic reflection coefficients, which are in close correlation with the elastic properties, thickness, density, and attenuation and interface adhesion of these layered structures. An experimental method based on angular spectrum to evaluate the acoustic coefficient as a function of the incident angle, θ, and frequency, ω, is presented with high frequency time-resolved acoustic microscopy. In order to achieve a high spatial resolution for evaluation of thin plates with thicknesses about one or two wavelengths, a point focusing transducer with a nominal center frequency of 25 MHz is adopted. By measuring the V(z, t) data in pulse mode, the reflection coefficient, R(θ, ω), can be reconstructed from its two-dimensional spectrum. It brings simplicity to experimental setup and measurement procedure since only single translation of the transducer in the vertical direction is competent for incident angle and frequency acquisition. It overcomes the disadvantages of the conventional methods requiring the spectroscopy for frequency scanning and/or ultrasonic goniometer for angular scanning. Two substrates of aluminum and Plexiglas and four stainless plates with various thicknesses of 100 μm, 150 μm, 200 μm, and 250 μm were applied. The acoustic reflection coefficients are consistent with the corresponding theoretical calculations. It opened the way of non-destructive methodology to evaluate the elastic and geometrical properties of very thin multi-layers structures simultaneously.

  6. Instrument for measuring a burnup degree of reactor fuel elements by gamma-scanning method

    Energy Technology Data Exchange (ETDEWEB)

    Jozefowicz, E.T.; Kilim, S.; Lewicki, K.; Rusinowski, Z. (Institute of Nuclear Research, Warsaw (Poland))

    1979-01-01

    The principle of gamma scanning of fuel elements is presented. The measuring instrument built in the Institute of Nuclear Research at Swierk and used for gamma scanning of EK-10, WWR-SM, MR and WWER fuel elements is described. The technical drawing of the instrument is given.

  7. 40 CFR 92.117 - Gas meter or flow instrumentation calibration, particulate measurement.

    Science.gov (United States)

    2010-07-01

    ... ENGINES Test Procedures § 92.117 Gas meter or flow instrumentation calibration, particulate measurement... orifice, a bellmouth nozzle, or a laminar flow element or an NIST traceable flow calibration device is... best fit calibration curve for the instrument (as a function of the calibration device flow...

  8. Development of an Instrument to Measure Student Use of Academic Success Skills: An Exploratory Factor Analysis

    Science.gov (United States)

    Carey, John; Brigman, Greg; Webb, Linda; Villares, Elizabeth; Harrington, Karen

    2014-01-01

    This article describes the development of the Student Engagement in School Success Skills instrument including item development and exploratory factor analysis. The instrument was developed to measure student use of the skills and strategies identified as most critical for long-term school success that are typically taught by school counselors.

  9. Developing and Validating a New Instrument to Measure the Self-Efficacy of Elementary Mathematics Teachers

    Science.gov (United States)

    McGee, Jennifer Richardson

    2012-01-01

    The purpose of this study was the development and validation of an instrument to measure the self-efficacy of elementary mathematics teachers. Self-efficacy, as defined by Bandura, was the theoretical framework for the development of the instrument. The complex belief systems of mathematics teachers, as touted by Ernest (1989) provided insight…

  10. Reliability of the Measure of Acceptance of the Theory of Evolution (MATE) Instrument with University Students

    Science.gov (United States)

    Rutledge, Michael L.; Sadler, Kim C.

    2007-01-01

    The Measure of Acceptance of the Theory of Evolution (MATE) instrument was initially designed to assess high school biology teachers' acceptance of evolutionary theory. To determine if the MATE instrument is reliable with university students, it was administered to students in a non-majors biology course (n = 61) twice over a 3-week period.…

  11. Developing an instrument for measuring TQM implementation in a Chinese context

    NARCIS (Netherlands)

    Zhang, Z.

    1999-01-01

    From an extensive review of the literature of total quality management (TQM), eleven constructs of TQM implementation were identified. An instrument measuring these constructs was developed. The reliability and validity of the instrument were tested and validated using data from 212 Chinese manufact

  12. Development of an Instrument to Measure Consumer Satisfaction in Vocational Rehabilitation

    Science.gov (United States)

    Capella, Michele E.; Turner, Ronna C.

    2004-01-01

    Although state agencies are required by law to assess their consumers' satisfaction with vocational rehabilitation (VR), each state uses its own instrument to measure satisfaction. This not only makes comparisons across states impossible but also means that the quality of these instruments varies widely from state to state. As with other…

  13. Measuring Pre-Service Teachers' Self-Efficacy in Tutoring Children in Primary Mathematics: An Instrument

    Science.gov (United States)

    Bjerke, Annette Hessen; Eriksen, Elisabeta

    2016-01-01

    This article reports on the use of Rasch modelling to develop and validate an instrument measuring self-efficacy in tutoring children in primary mathematics (SETcPM). In response to the literature on teacher efficacy, the 20-item instrument aims to inform teacher educators, and is designed for novice pre-service teachers (nPSTs) preparing to teach…

  14. The Cabauw Intercomparison campaign for Nitrogen Dioxide measuring Instruments (CINDI): design, execution, and early results

    NARCIS (Netherlands)

    Henzing, J.S.; Leeuw, G. de; Piters, A.J.M.; Boersma, K.F.; Kroon, M.; Hains, J.C.; Roozendael, M. van; Wittrock, F.; Abuhassan, N.; Adams, C.; Akrami, M.; Allaart, M.A.F.; Apituley, A.; Bergwerff, J.B.; Berkhout, A.J.C.; Brunner, D.; Cede, A.; Chong, J.; Clémer, K.; Fayt, C.; Friess, U.; Gast, L.F.L.; Gil-Ojeda, M.; Goutail, F.; Graves, R.; Griesfeller, A.; Grossmann, K.; Hemerijckx, G.; Hendrick, F.; Herman, J.; Hermans, C.; Hoexum, M.; Hoff, G.R. van der; Irie, H.; Johnston, P.V.; Kanaya, Y.; Kim, Y.J.; Klein Baltink, H.; Kreher, K.; Leigh, R.; Merlaud, A.; Moerman, M.M.; Monks, P.S.; Mount, G.H.; Navarro-Comas, M.; Oetjen, H.; Pazmino, A.; Perez-Camacho, M.; Peters, E.; Piesanie, A. du; Pinardi, G.; Puentadura, O.; Richter, A.; Roscoe, H.K.; Schönhardt, A.; Schwarzenbach, B.; Shaiganfar, R.; Sluis, W.; Spinei, E.; Stolk, A.P.; Strong, K.; Swart, D.P.J.; Takashima, H.; Vlemmix, T.; Vrekoussis, M.; Wagner, T.; Whyte, C.; Wilson, K.M.; Yela, M.; Yilmaz, S.; Zieger, P.; Zhou, Y.

    2011-01-01

    From June to July 2009 more than thirty different in-situ and remote sensing instruments from all over the world participated in the Cabauw Intercomparison campaign for Nitrogen Dioxide measuring Instruments (CINDI). The campaign took place at KNMI’s 5 Cabauw Experimental Site for Atmospheric Resear

  15. The Cabauw Intercomparison campaign for Nitrogen Dioxide measuring Instruments (CINDI): Design, execution, and early results

    NARCIS (Netherlands)

    Piters, A.J.M.; Boersma, K.F.; Kroon, M.; Hains, J.C.; Roozendael, M. van; Wittrock, F.; Abuhassan, N.; Adams, C.; Akrami, M.; Allaart, M.A.F.; Apituley, A.; Beirle, S.; Bergwerff, J.B.; Berkhout, A.J.C.; Brunner, D.; Cede, A.; Chong, J.; Clémer, K.; Fayt, C.; Frieß, U.; Gast, L.F.L.; Gil-Ojeda, M.; Goutail, F.; Graves, R.; Griesfeller, A.; Großmann, K.; Hemerijckx, G.; Hendrick, F.; Henzing, B.; Herman, J.; Hermans, C.; Hoexum, M.; Hoff, G.R. van der; Irie, H.; Johnston, P.V.; Kanaya, Y.; Kim, Y.J.; Klein Baltink, H.; Kreher, K.; Leeuw, G. de; Leigh, R.; Merlaud, A.; Moerman, M.M.; Monks, P.S.; Mount, G.H.; Navarro-Comas, M.; Oetjen, H.; Pazmino, A.; Perez-Camacho, M.; Peters, E.; Du Piesanie, A.; Pinardi, G.; Puentedura, O.; Richter, A.; Roscoe, H.K.; Schönhardt, A.; Schwarzenbach, B.; Shaiganfar, R.; Sluis, W.; Spinei, E.; Stolk, A.P.; Strong, K.; Swart, D.P.J.; Takashima, H.; Vlemmix, T.; Vrekoussis, M.; Wagner, T.; Whyte, C.; Wilson, K.M.; Yela, M.; Yilmaz, S.; Zieger, P.; Zhou, Y.

    2012-01-01

    From June to July 2009 more than thirty different in-situ and remote sensing instruments from all over the world participated in the Cabauw Intercomparison campaign for Nitrogen Dioxide measuring Instruments (CINDI). The campaign took place at KNMI's Cabauw Experimental Site for Atmospheric Research

  16. The knee adduction moment measured with an instrumented force shoe in patients with knee osteoarthritis

    NARCIS (Netherlands)

    Noort, van den Josien C.; Esch, van der Martin; Steultjens, Martijn P.M.; Dekker, Joost; Schepers, H. Martin; Veltink, Peter H.; Harlaar, Jaap

    2012-01-01

    The external knee adduction moment (KAdM) during gait is an important parameter in patients with knee osteoarthritis (OA). KAdM measurement is currently restricted to instruments only available in gait laboratories. However, ambulatory movement analysis technology, including instrumented force shoes

  17. Can Reliability of Multiple Component Measuring Instruments Depend on Response Option Presentation Mode?

    Science.gov (United States)

    Menold, Natalja; Raykov, Tenko

    2016-01-01

    This article examines the possible dependency of composite reliability on presentation format of the elements of a multi-item measuring instrument. Using empirical data and a recent method for interval estimation of group differences in reliability, we demonstrate that the reliability of an instrument need not be the same when polarity of the…

  18. A systematic review of patient-reported outcome instruments measuring sleep dysfunction in adults.

    Science.gov (United States)

    Devine, Emily Beth; Hakim, Zafar; Green, Jesse

    2005-01-01

    Sleep dysfunction can manifest in several ways, ranging from insomnia to somnolence, and from disrupted sleep to lack of restful sleep. Measuring sleep dysfunction is an area of active research and there exist a number of patient-reported outcome instruments that measure various aspects of sleep dysfunction. However, these instruments have not been evaluated systematically. We used a conceptual model of sleep that included four physical domains of general interest to patients and investigators, and cover the breadth of this disorder: sleep initiation; sleep maintenance; sleep adequacy; and somnolence. We next considered the additional health-related quality-of-life (HR-QOL) domains of psychological and social functioning, progressing along the continuum to include health perceptions and opportunity. We then conducted a literature review to identify instruments and, using criteria developed by the Medical Outcomes Trust Scientific Advisory Committee, evaluated these instruments for their potential use in measuring sleep dysfunction. Twenty-two instruments were identified. Six instruments were found to include the four physical domains defined a priori (Basic Nordic Sleep Questionnaire, Leeds Sleep Evaluation Questionnaire, Medical Outcomes Study - Sleep Problems Measures, Pittsburgh Sleep Diary, Pittsburgh Sleep Quality Index, Self-Rated Sleep Questionnaire and the Sleep Dissatisfaction Questionnaire). Several additional instruments addressed at least some of the domains and thus may be useful for specific purposes. A few instruments addressed overall HR-QOL, but did not include all four domains of interest (Functional Outcomes of Sleep Questionnaire, Quality of Life in Insomniacs and the Sleep-Wake Activity Inventory). Two instruments had undergone extensive psychometric evaluation (Medical Outcomes Study - Sleep Problems Measures and Pittsburgh Sleep Quality Index), with only the latter reporting information about interpretability. Our review indicates that

  19. Two-dimensional direction finding for low altitude target based on intensity measurement using an acoustic vector-sensor

    Institute of Scientific and Technical Information of China (English)

    CHEN Huawei; ZHAO Junwei

    2004-01-01

    A method of two-dimensional direction of arrival (DOA) estimation for low altitude target, which is based on intensity measurement using a three-dimensional differential pressure acoustic vector-sensor, is presented. With the perfect characteristics of acoustic vector sensor in the low frequency band, accurate DOA estimation is achieved under small array size. The validity of the proposed method was assessed by experiments on the noise signals radiated by a helicopter. The influence of acoustic sensor size, integral time and signal to noise ratio to the accuracy of DOA estimation were investigated, respectively. The performance comparisons demonstrated that it outperformed the traditional time-delay measurement based method for a small acoustic array.

  20. 27 CFR 19.277 - Measuring devices and proofing instruments.

    Science.gov (United States)

    2010-04-01

    ... those prescribed in 27 CFR part 30. Proprietors shall make frequent tests of their hydrometers and... person. (c) Meters. The appropriate TTB officer may approve applications to measure spirits by meter...

  1. Time series analysis of the response of measurement instruments

    CERN Document Server

    Georgakaki, Dimitra; Polatoglou, Hariton

    2012-01-01

    In this work the significance of treating a set of measurements as a time series is being explored. Time Series Analysis (TSA) techniques, part of the Exploratory Data Analysis (EDA) approach, can provide much insight regarding the stochastic correlations that are induced on the outcome of an experiment by the measurement system and can provide criteria for the limited use of the classical variance in metrology. Specifically, techniques such as the Lag Plots, Autocorrelation Function, Power Spectral Density and Allan Variance are used to analyze series of sequential measurements, collected at equal time intervals from an electromechanical transducer. These techniques are used in conjunction with power law models of stochastic noise in order to characterize time or frequency regimes for which the usually assumed white noise model is adequate for the description of the measurement system response. However, through the detection of colored noise, usually referred to as flicker noise, which is expected to appear ...

  2. Indirect calibration of a large microphone array for in-duct acoustic measurements

    Science.gov (United States)

    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.

  3. Ultrasonic Measurement of Strain Distribution Inside Object Cyclically Compressed by Dual Acoustic Radiation Force

    Science.gov (United States)

    Odagiri, Yoshitaka; Hasegawa, Hideyuki; Kanai, Hiroshi

    2008-05-01

    One possible way to evaluate acupuncture therapy quantitatively is to measure the change in the elastic property of muscle after application of the therapy. Many studies have been conducted to measure mechanical properties of tissues using ultrasound-induced acoustic radiation force. To assess mechanical properties, strain must be generated in an object. However, a single radiation force is not effective because it mainly generates translational motion when the object is much harder than the surrounding medium. In this study, two cyclic radiation forces are simultaneously applied to a muscle phantom from two opposite horizontal directions so that the object is cyclically compressed in the horizontal direction. By the horizontal compression, the object is expanded vertically based on its incompressibility. The resultant vertical displacement is measured using another ultrasound pulse. Two ultrasonic transducers for actuation were both driven by the sum of two continuous sinusoidal signals at two slightly different frequencies [1 MHz and (1 M + 5) Hz]. The displacement of several micrometers in amplitude, which fluctuated at 5 Hz, was measured by the ultrasonic phased tracking method. Increase in thickness inside the object was observed just when acoustic radiation forces increased. Such changes in thickness correspond to vertical expansion due to horizontal compression.

  4. POLARBEAR-2: an instrument for CMB polarization measurements

    CERN Document Server

    Inoue, Y; Akiba, Y; Aleman, C; Arnold, K; Baccigalupi, C; Barch, B; Barron, D; Bender, A; Boettger, D; Borrill, J; Chapman, S; Chinone, Y; Cukierman, A; de Haan, T; Dobbs, M A; Ducout, A; Dunner, R; Elleflot, T; Errard, J; Fabbian, G; Feeney, S; Feng, C; Fuller, G; Gilbert, A J; Goeckner-Wald, N; Groh, J; Hall, G; Halverson, N; Hamada, T; Hasegawa, M; Hattori, K; Hazumi, M; Hill, C; Holzapfel, W L; Hori, Y; Howe, L; Irie, F; Jaehnig, G; Jaffe, A; Jeongh, O; Katayama, N; Kaufman, J P; Kazemzadeh, K; Keating, B G; Kermish, Z; Keskital, R; Kisner, T; Kusaka, A; Jeune, M Le; Lee, A T; Leon, D; Linder, E V; Lowry, L; Matsuda, F; Matsumura, T; Miller, N; Mizukami, K; Montgomery, J; Navaroli, M; Nishino, H; Paar, H; Peloton, J; Poletti, D; Puglisi, G; Raum, C R; Rebeiz, G M; Reichardt, C L; Richards, P L; Ross, C; Rotermund, K M; Segaw, Y; Sherwin, B D; Shirley, I; Siritanasak, P; Stebor, N; Suzuki, R Stompor A; Tajima, O; Takada, S; Takatori, S; Teply, G P; Tikhomirol, A; Tomaru, T; Whitehorn, N; Zahn, A; Zahn, O

    2016-01-01

    POLARBEAR-2 (PB-2) is a cosmic microwave background (CMB) polarization experiment that will be located in the Atacama highland in Chile at an altitude of 5200 m. Its science goals are to measure the CMB polarization signals originating from both primordial gravitational waves and weak lensing. PB-2 is designed to measure the tensor to scalar ratio, r, with precision {\\sigma}(r) < 0.01, and the sum of neutrino masses, {\\Sigma}m{\

  5. Specific Heat and Second Sound Measurements with the DYNAMIX Instrument

    Science.gov (United States)

    Nissen, Joel

    2003-01-01

    In addition to its primary role of studying non-linear heat transport effects near the lambda transition of He-4, the DYNAMX apparatus is suitable for measurements of the specific heat and the velocity of second sound. We plan to take advantage of available time on orbit to make measurements in these areas near to the lambda transition. The specific heat work would be similar to LPE, aimed at improving our knowledge of the singularity in the bulk heat capacity at the transition, but would provide more accurate results close to the transition. It would focus roughly equally on each side of the transition and would be synergistic with the CQ experiment, providing wider-range data at Q = 0. The second sound measurements are made possible by the fast time constant and high resolution of the DYNAMX thermometers, which allow accurate time-of-flight measurements of second sound pulses. It appears possible to measure the second sound velocity to about 1% at a reduced temperature of t = 5x10(exp -8) by averaging over a moderate number of pulses. The data would complement and extend earlier ground-based measurements, leading to improved tests of the theory of static critical phenomena at the lambda transition.

  6. Galaxy bias and its effects on the Baryon acoustic oscillations measurements

    Energy Technology Data Exchange (ETDEWEB)

    Mehta, Kushal T. [Univ. of Arizona, Tucson, AZ (United States); Seo, Hee -Jong [Univ. of California, Berkeley, CA (United States); Fermi National Accelerator Lab., Batavia, IL (United States); Eckel, Jonathan [Univ. of Arizona, Tucson, AZ (United States); Eisenstein, Daniel J. [Univ. of Arizona, Tucson, AZ (United States); Harvard Univ., Cambridge, MA (United States); Metchnik, Marc [Univ. of Arizona, Tucson, AZ (United States); Pinto, Philip [Univ. of Arizona, Tucson, AZ (United States); Xu, Xiaoying [Univ. of Arizona, Tucson, AZ (United States)

    2011-05-31

    The baryon acoustic oscillation (BAO) feature in the clustering of matter in the universe serves as a robust standard ruler and hence can be used to map the expansion history of the universe. We use high force resolution simulations to analyze the effects of galaxy bias on the measurements of the BAO signal. We apply a variety of Halo Occupation Distributions (HODs) and produce biased mass tracers to mimic different galaxy populations. We investigate whether galaxy bias changes the non-linear shifts on the acoustic scale relative to the underlying dark matter distribution presented by Seo et al. (2009). For the less biased HOD models (b < 3), we do not detect any shift in the acoustic scale relative to the no-bias case, typically 0.10% ± 0.10%. However, the most biased HOD models (b > 3) show a shift at moderate significance (0.79% ± 0.31% for the most extreme case). We test the one-step reconstruction technique introduced by Eisenstein et al. (2007) in the case of realistic galaxy bias and shot noise. The reconstruction scheme increases the correlation between the initial and final (z = 1) density fields achieving an equivalent level of correlation at nearly twice the wavenumber after reconstruction. Reconstruction reduces the shifts and errors on the shifts. We find that after reconstruction the shifts from the galaxy cases and the dark matter case are consistent with each other and with no shift. The 1σ systematic errors on the distance measurements inferred from our BAO measurements with various HODs after reconstruction are about 0.07%-0.15%.

  7. The Belgian Risk Perception Barometer Risk Perception Measuring Instruments Revisited

    Energy Technology Data Exchange (ETDEWEB)

    Aeken, Koen van; Carle, Benny; Hardeman, Frank [SCK-CEN, Mol (Belgium). PISA

    2006-09-15

    The recognition of the societal dimension of risk assessment has been at the cradle of the opinion research on risks. Since risk estimates are not fixed by experts anymore, but are considered to show variation across a diverse population, the people themselves must be asked how they experience the risks. Following the rise in popularity of risk assessment and the recognition of its 'human' dimension, the demand for public opinion surveys on risks has been increasing at a fast pace. Unfortunately, this high demand sees some negative consequences. First, surveys are frequently conducted by people lacking even a minimal knowledge of survey methodology. In this respect, we might think of a journal or a newspaper trying to impress their readers with the definitive public opinion poll about the latest issue in vogue. Second, time pressure causes experienced or trained researchers to lower themselves to 'quick and dirty' work. While methodologically flawed opinion research might not be something to worry about when appearing in the amusement press, concern is due if the results of a survey inspire policy development. Indeed, when public opinion research is conceived as an instrument to support rational, evidence based public policy, the strictest methodological standards should be applied, even if it is clear that scientific research will never substitute political reasoning. This contribution deals with the safeguarding and enhancing of the quality of large scale surveys focusing on risk perception and related issues. This attention is relevant, not only for the reason that methodological standards may be flawed due to the immense popularity of the opinion poll, but also because the results of opinion surveys may have far-reaching policy consequences.

  8. The Belgian Risk Perception Barometer Risk Perception Measuring Instruments Revisited

    International Nuclear Information System (INIS)

    The recognition of the societal dimension of risk assessment has been at the cradle of the opinion research on risks. Since risk estimates are not fixed by experts anymore, but are considered to show variation across a diverse population, the people themselves must be asked how they experience the risks. Following the rise in popularity of risk assessment and the recognition of its 'human' dimension, the demand for public opinion surveys on risks has been increasing at a fast pace. Unfortunately, this high demand sees some negative consequences. First, surveys are frequently conducted by people lacking even a minimal knowledge of survey methodology. In this respect, we might think of a journal or a newspaper trying to impress their readers with the definitive public opinion poll about the latest issue in vogue. Second, time pressure causes experienced or trained researchers to lower themselves to 'quick and dirty' work. While methodologically flawed opinion research might not be something to worry about when appearing in the amusement press, concern is due if the results of a survey inspire policy development. Indeed, when public opinion research is conceived as an instrument to support rational, evidence based public policy, the strictest methodological standards should be applied, even if it is clear that scientific research will never substitute political reasoning. This contribution deals with the safeguarding and enhancing of the quality of large scale surveys focusing on risk perception and related issues. This attention is relevant, not only for the reason that methodological standards may be flawed due to the immense popularity of the opinion poll, but also because the results of opinion surveys may have far-reaching policy consequences

  9. Compressive sensing beamforming based on covariance for acoustic imaging with noisy measurements.

    Science.gov (United States)

    Zhong, Siyang; Wei, Qingkai; Huang, Xun

    2013-11-01

    Compressive sensing, a newly emerging method from information technology, is applied to array beamforming and associated acoustic applications. A compressive sensing beamforming method (CSB-II) is developed based on sampling covariance matrix, assuming spatially sparse and incoherent signals, and then examined using both simulations and aeroacoustic measurements. The simulation results clearly show that the proposed CSB-II method is robust to sensing noise. In addition, aeroacoustic tests of a landing gear model demonstrate the good performance in terms of resolution and sidelobe rejection.

  10. All-Fiber DBR-Based Sensor Interrogation System for Measuring Acoustic Waves

    Directory of Open Access Journals (Sweden)

    Maria Iulia Comanici

    2012-01-01

    Full Text Available We investigate the use of all-fiber distributed Bragg reflector (DBR lasers for fiber optic sensing. We measure the steady-state strain response and show that it is very similar to that for a simple fiber Bragg grating (FBG. The lasers can be wavelength multiplexed and support multisensor operation without crosstalk. We also verify the principle of wavelength-to-power mapping, which can simplify sensor interrogation. Finally, we demonstrate that all-fiber DBR lasers can be used to detect acoustic waves.

  11. Southeast Alaska Acoustic Measurement Facility (SEAFAC) environmental data base review, evaluation, and upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Strand, J.A.; Skalski, J.R.; Faulkner, L.L.; Rodman, C.W.; Carlile, D.W.; Ecker, R.M.; Nicholls, A.K.; Ramsdell, J.V.; Scott, M.J.

    1986-04-01

    This report summarizes the principal issues of public concern, the adequacy of the environmental data base to answer the issues of concern, and the additional data collection required to support a National Environmental Policy Act (NEPA) review of the proposed Southeast Alaska Acoustic Measurement Facility (SEAFAC). The report is based on a review of the readily available environmental literature and a site visit. Representatives of local, state, and federal agencies were also interviewed for their personal insights and concerns not discovered during the literature review.

  12. Rocket borne instrument to measure electric fields inside electrified clouds

    Science.gov (United States)

    Ruhnke, L. H. (Inventor)

    1973-01-01

    An apparatus for measuring the electric field in the atmosphere which includes a pair of sensors carried on a rocket for sensing the voltages in the atmosphere being measured is described. One of the sensors is an elongated probe with a fine point which causes a corona current to be produced as it passes through the electric field. An electric circuit is coupled between the probe and the other sensor and includes a high ohm resistor which linearizes the relationship between the corona current and the electric field being measured. A relaxation oscillator and transmitter are provided for generating and transmitting an electric signal having a frequency corresponding to the magnitude of the electric field.

  13. The Problem of the Instrument Stabilization During Hydrographic Measurements

    Science.gov (United States)

    Felski, Andrzej; Naus, Krzysztof; Wąż, Mariusz

    2016-06-01

    Performing any measurement on watercraft is connected with many additional difficulties caused by the sea-environment. The most important is the problem of spatial stabilization of measurement systems, which are usually fastened to craft body. As soon as usually these measurement are executed during the move of the craft additional question is the accuracy of execution the planed trajectory. This is a problem for all investigators, especially when system use spatially configured beams of any antennas or other sensors, regardless is it receiving or transmitting one. Different aspects of these question are the subject of research activity of Institute of Navigation and Maritime Hydrography of Polish Naval Academy. In this paper the review of works executed in last years are presented.

  14. An Instrument for the Measurement of Parental Authority Prototypes.

    Science.gov (United States)

    Buri, John R.

    Baumrind (1971) proposed three distinct patterns of parental authority (permissiveness, authoritarianism, and authoritativeness) and measured these parenting styles through interviews with parents and their children and through observations of parents interacting with their children. This study was undertaken to develop a readily-accessible,…

  15. Instrument measures many optical properties in visible and IR

    Science.gov (United States)

    Batten, C. E.

    1979-01-01

    Electro-optical system measures reflectance, reflectance ratio, transmission, absorption, refractive index, and absorption coefficient in both visible and infrared (IR) spectral regions. System effectively combining capabilities of ellisometer, reflectometer, and spectrophotometer is expected to find application in environmental and material composition testing fields.

  16. Workplace Discrimination, Prejudice, and Diversity Measurement: A Review of Instrumentation.

    Science.gov (United States)

    Burkard, Alan W.; Boticki, Michael A.; Madson, Michael B.

    2002-01-01

    Critically reviews diversity measures in terms of item development, psychometric evidence, and utility for counseling and development: Workplace Prejudice/Discrimination Inventory, Attitudes toward Diversity Scale; Organizational Diversity Inventory, Workforce Diversity Questionnaire, Perceived Occupational Opportunity Scale-Form B, and Perceived…

  17. Roughness measurements with an AFM-CMM instrument

    DEFF Research Database (Denmark)

    Marinello, Francesco; Bariani, Paolo; De Chiffre, Leonardo;

    2005-01-01

    In this paper, application of a Large Range AFM to roughness analyses is presented: measurements on different calibration standards covering a range of 4.8×0.1 mm2 were performed. Upon extraction of single profiles from the three-dimensional data set, roughness can be evaluated in compliance...

  18. Comparing Alternative Instruments to Measure Service Quality in Higher Education

    Science.gov (United States)

    Brochado, Ana

    2009-01-01

    Purpose: The purpose of this paper is to examine the performance of five alternative measures of service quality in the high education sector--service quality (SERVQUAL), importance-weighted SERVQUAL, service performance (SERVPERF), importance-weighted SERVPERF, and higher education performance (HEdPERF). Design/methodology/approach: Data were…

  19. Reliability and validity of an instrument to measure the beliefs of intrapartum nurses.

    Science.gov (United States)

    Adams, Ellise D; Sauls, Donna J

    2014-01-01

    Intrapartum nurses assume a central role in the birth process and make decisions driven by a set of beliefs. Therefore, the purpose of this study was to develop a valid and reliable instrument to measure birth beliefs of intrapartum nurses related to birth practice. A total of 313 intrapartum nurses accessed this online, self-administered instrument over a 3-month period. The Theory of Planned Behavior guided development of the Intrapartum Nurses' Beliefs Related to Birth Practice scale and provided a basis for the connection between beliefs and practice. This article describes the psychometric analysis of the instrument. Findings include a moderate, positive correlation with a similar instrument, a Cronbach α of 0.797, and 2 factors identifying belief systems. With further revision, this instrument may provide an accurate measure of the birth beliefs of intrapartum nurses. PMID:24781771

  20. WISM - A Wideband Instrument for Snow Measurement: Past Accomplishments, Current Status, and Path Forward

    Science.gov (United States)

    Bonds, Quenton; Racette, Paul; Durham, Tim (Principal Investigator)

    2016-01-01

    Presented are the prior accomplishments, current status and path forward for GSFC's Wideband Instrument for Snow Measurement (WISM). This work is a high level overview of the project, presented via Webinar to the IEEE young professionals.

  1. Measuring Empowerment Among People With Psychotic Disorders: A Comparison of Three Instruments

    NARCIS (Netherlands)

    Castelein, S.; Gaag, van der M.; Bruggeman, R.; Busschbach, J.T.; Wiersma, D.

    2008-01-01

    OBJECTIVE: This study compared three instruments that are used to measure empowerment of people with psychotic disorders. The study evaluated internal consistency, discriminant and convergent validity, sensitivity to symptom levels, and clinical usefulness. METHODS: Fifty patients in the Netherlands

  2. Measuring Empowerment Among People With Psychotic Disorders : A Comparison of Three Instruments

    NARCIS (Netherlands)

    Castelein, Stynke; van der Gaag, Mark; Bruggeman, Richard; van Busschbach, Jooske T.; Wiersma, Durk

    2008-01-01

    Objective: This study compared three instruments that are used to measure empowerment of people with psychotic disorders. The study evaluated internal consistency, discriminant and convergent validity, sensitivity to symptom levels, and clinical usefulness. Methods: Fifty patients in the Netherlands

  3. Measuring Emotions Toward Wildlife: A Review of Generic Methods and Instruments

    NARCIS (Netherlands)

    Jacobs, M.H.; Fehres, P.; Campbell, M.

    2012-01-01

    Researchers are recognizing the importance of studying emotions for understanding human–wildlife interactions. This article reviews generic methods and instruments for assessing emotions, as developed within the affective sciences. Four broad categories of emotion measures can be distinguished: (a)

  4. UAV Flight Instrumentation for the In-Situ Measurement of Aerosol Optical Properties Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Los Gatos Research, Inc. (LGR) proposes to develop a flight ready instrument, capable of deployment on unmanned aerial vehicles (UAVs) to simultaneously measure in...

  5. Measuring the distance-redshift relation with the baryon acoustic oscillations of galaxy clusters

    Science.gov (United States)

    Veropalumbo, A.; Marulli, F.; Moscardini, L.; Moresco, M.; Cimatti, A.

    2016-05-01

    We analyse the largest spectroscopic samples of galaxy clusters to date, and provide observational constraints on the distance-redshift relation from baryon acoustic oscillations. The cluster samples considered in this work have been extracted from the Sloan Digital Sky Survey at three median redshifts, z = 0.2, 0.3 and 0.5. The number of objects is 12 910, 42 215 and 11 816, respectively. We detect the peak of baryon acoustic oscillations for all the three samples. The derived distance constraints are rs/DV(z = 0.2) = 0.18 ± 0.01, rs/DV(z = 0.3) = 0.124 ± 0.004 and rs/DV(z = 0.5) = 0.080 ± 0.002. Combining these measurements with the sound horizon scale measured from the cosmic microwave background, we obtain robust constraints on cosmological parameters. Our results are in agreement with the standard Λ cold dark matter (ΛCDM) model. Specifically, we constrain the Hubble constant in a ΛCDM model, H_0 = 64_{-8}^{+17} km s^{-1} Mpc^{-1} , the density of curvature energy, in the oΛCDM context, Ω _K = -0.01_{-0.33}^{+0.34}, and finally the parameter of the dark energy equation of state in the wCDM case, w = -1.06_{-0.52}^{+0.49}. This is the first time the distance-redshift relation has been constrained using only the peak of baryon acoustic oscillations of galaxy clusters.

  6. Flight and attitude dynamics measurements of an instrumented Frisbee

    Science.gov (United States)

    Lorenz, Ralph D.

    2005-03-01

    In-flight measurements are made of the translational accelerations and attitude motion of a hand-thrown flying disc using miniaturized accelerometers and other sensors and a microcontroller data acquisition system. The experiments explore the capabilities and limitations of sensors on a rapidly rotating platform moving in air, and illustrate several of the complex gyrodynamic aspects of Frisbee flight. The data give insight into the biomechanics of Frisbee launch, and indicate lift, drag and pitch moment coefficients consistent with previous wind-tunnel measurements. The experiments constitute an instructive exercise in aerospace vehicle systems integration and in attitude reconstruction, and open the way to guided disc wings using control surfaces actuated during specific spin phases determined by onboard sensors.

  7. Modern method and instrument for measuring psychic performance

    Science.gov (United States)

    Hideg, Janos; Remes, Peter; Bognar, Laszlo; Agoston, Mihaly

    This paper shows that cortical processing of information quantity can be given in bits, while speed of information processing can be given in bit/sec; therefore the information processing ability can be denoted in algebraical expression. Changes of emotional tension can be objectified by galvanic skin reflex and pulse reaction. This method and device is suitable to measure psychic state of space station personnel and to predict psychic activity.

  8. Measurement Instruments and Software Used in Biotribology Research Laboratory

    Directory of Open Access Journals (Sweden)

    Tyurin Andrei

    2015-07-01

    Full Text Available Precision measurements of friction processes have a key role in a variety of industrial processes. The emergence of fine electronic circuit techniques greatly expands capabilities of control. There are some difficulties for their full implementation today, especially when it regards the accuracy and frequency of measurements. The motion-measuring method in real-time system is considered in this article, paying special attention to increased accuracy. This method is based on rapid analog digital converter (ADC, transmission program and digital signal processor (DSP algorithms. Description of laboratory devices is included: Tribal-T and universal friction machine (MTU-01 designed for “Pin on disc” tests. Great emphasis is placed on the usability of accelerometers. The present study examined the collected data via laboratory system for data acquisition and control, and processing it in the laboratory of Biotribology. Laboratory supervisory control and data acquisition (SCADA algorithms is described below. Task of regulation is not considered. This paper describes only methods of automatic control theory to analyze the frictional quality.

  9. EVALUATION OF HAMSTRING FLEXIBILITY BY USING TWO DIFFERENT MEASURING INSTRUMENTS

    Directory of Open Access Journals (Sweden)

    Bakirtzoglou Fotis

    2010-12-01

    Full Text Available The purpose of the present study was to investigate the effect of two different methods ofmeasurement for hamstring flexibility. Forty male students athletes with mean age 23.45±0.44years and forty non-athletes students with a mean age 23.08±0.98 years participated in this study.Hamstring flexibility was evaluated by two different methods of measurement: a a Myrin goniometerand b sit and reach test. Statistical analysis included the use of Independent Samples Ttestwhile significance was set at p<0.01. The results indicated that athletes students scored betterthan non-athletes students only when hip joint’s mobility was measured with a Myrin goniometer.In conclusion the evaluation of joint's mobility should be done by using a method of measurementthat would isolate the articulation of measurement from the interjection of other joints ormuscular teams something that is achieved by the use of Myrin goniometer than the use of Sitand Reach test.

  10. A novel wide-range precision instrument for measuring three-dimensional surface topography

    Institute of Scientific and Technical Information of China (English)

    YANG Xu-dong; CHEN Yu-rong; XIE Tie-bang

    2008-01-01

    We developed a measuring instrument that had wide range, high precision, small measuring touch force. The instrument for three-dimensional (3D) surface topography measurement was composed of a high precision displacement sensor based on the Michelson interference principle, a 3D platform based on vertical scanning, a measuring and control circuit, and an industrial control computer. It was a closed loop control system, which changed the traditional moving stylus scanning style into a moving platform scanning style. When the workpiece was measured, the lever of the displacement sensor returned to the balanced position in every sample interval according to the zero offset of the displacement sensor. The non-linear error caused by the rotation of the lever was, therefore, very small even if the measuring range was wide. The instrument can measure the roughness and the profile size of a curved surface.

  11. Developing and validating a hostility, gratefulness and active support measuring instrument / Angelique Flattery

    OpenAIRE

    Flattery, Angelique

    2010-01-01

    South Africa is a very diverse country. There are eleven spoken official languages, different cultures, beliefs, backgrounds, educational levels, races as well as differences in socioeconomic status. Psychometric measuring instruments used in South Africa are mostly imported from Europe or America and are often not standardised for the South African context. The translation of such imported measuring instruments usually results in bias, in contravention of the Employment Equity Act (1998) whi...

  12. Quality of care and patient satisfaction: a review of measuring instruments.

    OpenAIRE

    Campen, C. van; Sixma, H; Friele, R.D.; Kerssens, J. J.; L. Peters

    1995-01-01

    Surveying the literature on the assessment of quality of care from the patient's perspective, the concept has often been operationalized as patient satisfaction. Patient satisfaction has been a widely investigated subject in health care research, and dozens of measuring instruments were developed during the past decade. Quality of care from the patient's perspective, however, has been investigated only very recently, and only a few measuring instruments have explicitly been developed for the ...

  13. Airborne Multi AXis DOAS instrument and measurements of two-dimensional tropospheric trace gas distributions

    OpenAIRE

    Heue, Klaus-Peter

    2005-01-01

    The Airborne Multi AXis DOAS instrument was developed and successfully operated during four measurement campaigns. Depending on the purpose the instrument was installed on two different aeroplanes flying either close to the tropopause or in the mixing layer. In a detailed sensitivity study the possibilities of the measurements were investigated. For a qualitatively good observation of tropospheric trace gases (e.g. NO2 and HCHO) additional information about the mixing layer height and the aer...

  14. A Systematic Review of Patient-Reported Outcome Instruments Measuring Sleep Dysfunction in Adults

    OpenAIRE

    Emily Beth Devine; Zafar Hakim; Jesse Green

    2005-01-01

    Sleep dysfunction can manifest in several ways, ranging from insomnia to somnolence, and from disrupted sleep to lack of restful sleep. Measuring sleep dysfunction is an area of active research and there exist a number of patient-reported outcome instruments that measure various aspects of sleep dysfunction. However, these instruments have not been evaluated systematically. We used a conceptual model of sleep that included four physical domains of general interest to patients and investigator...

  15. Measurement equivalence of the food related lifestyle instrument (FRL) in Ireland and Great Britain

    DEFF Research Database (Denmark)

    O´Sullivan, C.; Scholderer, Joachim; Cowan, Cathal

    2005-01-01

    domains, the measurement characteristics of the survey instrument were completely invariant across the two cultures. No indication was found of any bias. Regarding future applications of the FRL, it can be concluded that the instrument has identical measurement characteristics when applied to consumer......The food-related lifestyle instrument (FRL) is tested for cross-cultural validity. Representative consumer samples from the UK 1998 ( N = 1000) and Ireland 2001 (N = 1024) are compared using multi-sample confirmatory factor analysis with structured means. The results suggest that, in all five FRL...

  16. Modelling and Measurement Uncertainty Estimation for Integrated AFM-CMM Instrument

    DEFF Research Database (Denmark)

    Hansen, Hans Nørgaard; Bariani, Paolo; De Chiffre, Leonardo

    2005-01-01

    This paper describes modelling of an integrated AFM - CMM instrument, its calibration, and estimation of measurement uncertainty. Positioning errors were seen to limit the instrument performance. Software for off-line stitching of single AFM scans was developed and verified, which allows...... compensation of such errors. A geometrical model of the instrument was produced, describing the interaction between AFM and CMM systematic errors. The model parameters were quantified through calibration, and the model used for establishing an optimised measurement procedure for surface mapping. A maximum...... uncertainty of 0.8% was achieved for the case of surface mapping of 1.2*1.2 mm2 consisting of 49 single AFM scanned areas....

  17. Portable Instrument to Measure CDOM Light Absorption in Aquatic Systems: WPI Success Story

    Science.gov (United States)

    2001-01-01

    World Precision Instruments, Inc. (WPI), of Sarasota, FL, in collaboration with NASA's John C. Stennis Space Center, has developed an innovative instrument to accurately measure Colored Dissolved Organic Matter (CDOM) absorption in the field. This successful collaboration has culminated in an exciting new device, called the UltraPath, now commercially available through WPI. Traditional methods of measuring absorption of dissolved materials require special handling and storage prior to measurement. Use of laboratory spectrophotometers as the measuring devices have proven time consuming, cumbersome, and delicate to handle. The UltraPath provides a low-cost, highly sensitive, rugged, portable system that is capable of high sensitivity measurements in widely divergent waters.

  18. Labor Relations and Social Dialogue: Measurement and Diagnosis Instruments

    Directory of Open Access Journals (Sweden)

    Viorel Lefter

    2007-02-01

    Full Text Available Social dialogue and tripartism play an important role in promoting and strengthening fundamental principles and rights at work, promoting job creation and expanding social protection. In the context of the severe challenges of globalization, a growing number of developing countries are recognizing the need to faster dialogue, partnership and participatory approaches to decision-making. Thus, social dialogue becomes a prerequisite for efficient corporate governance and means to attain national economic and social objectives and to contribute to poverty reduction policies. We shall propose a diagnosis and analysis system in order to measure and monitor the evolution of the industrial relations and social dialogue.

  19. Development and characterization of a new instrument for the traceable measurement of areal surface texture

    International Nuclear Information System (INIS)

    Modern manufacturing industry is beginning to benefit greatly from the ability to control the three-dimensional, or areal, structure of a surface. To underpin areal surface manufacturing, a traceable measurement infrastructure is required. In this paper, the development of a new traceable instrument for the measurement of areal surface texture is presented. The instrument uses a two-axis coplanar air-bearing slideway to move the measured surface beneath a stylus probe. The motion of the slideway is measured using linear and angular interferometers. The key to the new instrument is a novel probing system incorporating a cylindrical air-bearing guideway and an electromagnetic system to maintain a constant stylus force on the surface. The deflection of the stylus is measured using a differential plane mirror interferometer thereby minimizing the effect of any error motion in the metrology frame. The uncertainties of the instrument are calculated using a Monte Carlo approach and are evaluated to be 5 nm in the z axis and 16 nm in the x and y axes (all at k = 2). The results are given for the instrument and are compared to results from a traceable profile measuring instrument and a coherence scanning interferometer

  20. Investigation of An Acoustic Temperature Transducer and its Application for Heater Temperature Measurement

    Directory of Open Access Journals (Sweden)

    Mohammad A.K. Alia

    2007-01-01

    Full Text Available Recent developments in temperature measurement have encouraged researchers to develop low-cost, simple structure, computerized generic transducers for environmental monitoring and industrial process control. The research presents a computerized technique which allows to measure temperature according to the variation of acoustic velocity (frequency in a closed waveguide. Signal conditioning and processing was carried out using labVIEW (G Language VIs. In order to evaluate the time characteristic of the transducer its response was compared with that of a reference detector (PT 100 for the same step input. Static characteristics of the transducer show a quasi-linear relationship between the measured temperature and the resonance frequency. Results of practical experiments show that in order to improve the response curve of the transducer and decrease the rising time interval it is advisable to implement thin-wall glass tubes or another material with lower thermal impedance.

  1. Measurement of Elastic Properties of Tissue by Shear Wave Propagation Generated by Acoustic Radiation Force

    Science.gov (United States)

    Tabaru, Marie; Azuma, Takashi; Hashiba, Kunio

    2010-07-01

    Acoustic radiation force (ARF) imaging has been developed as a novel elastography technology to diagnose hepatic disease and breast cancer. The accuracy of shear wave speed estimation, which is one of the applications of ARF elastography, is studied. The Young's moduli of pig liver and foie gras samples estimated from the shear wave speed were compared with those measured the static Young's modulus measurement. The difference in the two methods was 8%. Distance attenuation characteristics of the shear wave were also studied using finite element method (FEM) analysis. We found that the differences in the axial and lateral beam widths in pressure and ARF are 16 and 9% at F-number=0.9. We studied the relationship between two branch points in distance attenuation characteristics and the shape of ARF. We found that the maximum measurable length to estimate shear wave speed for one ARF excitation was 8 mm.

  2. Effects of Noise and Absorption on High Frequency Measurements of Acoustic-Backscatter from Fish

    Directory of Open Access Journals (Sweden)

    Masahiko Furusawa

    2015-01-01

    Full Text Available Quantitative echosounders operating at multiple frequencies (e.g., 18, 38, 70, 120, 200, 333, and 710 kHz are often used to observe fish and zooplankton and identify their species. At frequencies above 100 kHz, the absorption attenuation increases rapidly and decreases the signal-to-noise ratio (SNR. Also, incomplete compensation for the attenuation may result in measurement error. This paper addresses the effects of the attenuation and noise on high frequency measurements of acoustic backscatter from fish. It is shown that measurements of a fish with target strength of −40 dB at 200 m depth are limited by SNR to frequencies up to about 100 kHz. Above 100 kHz, absorption coefficients must be matched to local environmental conditions.

  3. High accuracy acoustic relative humidity measurement in duct flow with air.

    Science.gov (United States)

    van Schaik, Wilhelm; Grooten, Mart; Wernaart, Twan; van der Geld, Cees

    2010-01-01

    An acoustic relative humidity sensor for air-steam mixtures in duct flow is designed and tested. Theory, construction, calibration, considerations on dynamic response and results are presented. The measurement device is capable of measuring line averaged values of gas velocity, temperature and relative humidity (RH) instantaneously, by applying two ultrasonic transducers and an array of four temperature sensors. Measurement ranges are: gas velocity of 0-12 m/s with an error of ± 0.13 m/s, temperature 0-100 °C with an error of ± 0.07 °C and relative humidity 0-100% with accuracy better than 2 % RH above 50 °C. Main advantage over conventional humidity sensors is the high sensitivity at high RH at temperatures exceeding 50 °C, with accuracy increasing with increasing temperature. The sensors are non-intrusive and resist highly humid environments. PMID:22163610

  4. High Accuracy Acoustic Relative Humidity Measurement inDuct Flow with Air

    Directory of Open Access Journals (Sweden)

    Cees van der Geld

    2010-08-01

    Full Text Available An acoustic relative humidity sensor for air-steam mixtures in duct flow is designed and tested. Theory, construction, calibration, considerations on dynamic response and results are presented. The measurement device is capable of measuring line averaged values of gas velocity, temperature and relative humidity (RH instantaneously, by applying two ultrasonic transducers and an array of four temperature sensors. Measurement ranges are: gas velocity of 0–12 m/s with an error of ±0.13 m/s, temperature 0–100 °C with an error of ±0.07 °C and relative humidity 0–100% with accuracy better than 2 % RH above 50 °C. Main advantage over conventional humidity sensors is the high sensitivity at high RH at temperatures exceeding 50 °C, with accuracy increasing with increasing temperature. The sensors are non-intrusive and resist highly humid environments.

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

    Science.gov (United States)

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

    2002-01-01

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

  6. High accuracy acoustic relative humidity measurement in duct flow with air.

    Science.gov (United States)

    van Schaik, Wilhelm; Grooten, Mart; Wernaart, Twan; van der Geld, Cees

    2010-01-01

    An acoustic relative humidity sensor for air-steam mixtures in duct flow is designed and tested. Theory, construction, calibration, considerations on dynamic response and results are presented. The measurement device is capable of measuring line averaged values of gas velocity, temperature and relative humidity (RH) instantaneously, by applying two ultrasonic transducers and an array of four temperature sensors. Measurement ranges are: gas velocity of 0-12 m/s with an error of ± 0.13 m/s, temperature 0-100 °C with an error of ± 0.07 °C and relative humidity 0-100% with accuracy better than 2 % RH above 50 °C. Main advantage over conventional humidity sensors is the high sensitivity at high RH at temperatures exceeding 50 °C, with accuracy increasing with increasing temperature. The sensors are non-intrusive and resist highly humid environments.

  7. Development of an instrument to measure student attitudes toward science fairs

    Science.gov (United States)

    Huddleston, Claudia A.

    Science fairs are woven into the very fabric of science instruction in the United States and in other countries. Even though thousands of students participate in science fairs every year, no instrument to measure student attitudes toward partaking in this hands-on learning experience has been fully developed and available for school administrators and teachers to assess the perceived value that current students attribute to participation in science fairs. Therefore, the purpose of this study was to continue the development and refinement of an instrument that measured student attitudes towards science fairs based on an unpublished instrument created by Michael (2005). The instrument developed and tested using 110 students at two different middle schools in southwest Virginia. The instrument consisted of 45 questions. After applying a principal component factor analysis, the instrument was reduced to two domains, enjoyment and value. The internal consistency of the instrument was calculated using Cronbach's alpha and showed good internal consistency of .89 between the two domains. Further analysis was conducted using a Pearson product-moment test and showed a significant positive correlation between enjoyment and value (r = .78). Demographic information was explored concerning the domains using a series of statistical tests, and results revealed no significant differences among race and science fair category. However, a significant difference was found among gender and students who won awards and those who did not. The conclusion was that further development and refinement of the instrument should be conducted.

  8. Quantification and handling of sampling errors in instrumental measurements: a case study

    DEFF Research Database (Denmark)

    Andersen, Charlotte Møller; Bro, R.

    2004-01-01

    Instrumental measurements are often used to represent a whole object even though only a small part of the object is actually measured. This can introduce an error due to the inhomogeneity of the product. Together with other errors resulting from the measuring process, such errors may have a serious...... impact on the results when the instrumental measurements are used for multivariate regression and prediction. This paper gives examples of how errors influencing the predictions obtained by a multivariate regression model can be quantified and handled. Only random errors are considered here, while in...... certain situations, the effect of systematic errors is also considerable. The relevant errors contributing to the prediction error are: error in instrumental measurements (x-error), error in reference measurements (y-error), error in the estimated calibration model (regression coefficient error) and model...

  9. Acoustic measurement of sediment dynamics in the coastal zones using wireless sensor networks

    Science.gov (United States)

    Sudhakaran, A., II; Paramasivam, A.; Seshachalam, S.; A, C.

    2014-12-01

    Analyzing of the impact of constructive or low energy waves and deconstructive or high energy waves in the ocean are very much significant since they deform the geometry of seashore. The deformation may lead to productive result and also to the end of deteriorate damage. Constructive waves results deposition of sediment which widens the beach where as deconstructive waves results erosion which narrows the beach. Validation of historic sediment transportation and prediction of the direction of movement of seashore is essential to prevent unrecoverable damages by incorporating precautionary measurements to identify the factors that influence sediment transportation if feasible. The objective of this study is to propose a more reliable and energy efficient Information and communication system to model the Coastal Sediment Dynamics. Various factors influencing the sediment drift at a particular region is identified. Consequence of source depth and frequency dependencies of spread pattern in the presence of sediments is modeled. Property of source depth and frequency on sensitivity to values of model parameters are determined. Fundamental physical reasons for these sediment interaction effects are given. Shallow to deep water and internal and external wave model of ocean is obtained intended to get acoustic data assimilation (ADA). Signal processing algorithms are used over the observed data to form a full field acoustic propagation model and construct sound speed profile (SSP). The inversions of data due to uncertainties at various depths are compared. The impact of sediment drift over acoustic data is identified. An energy efficient multipath routing scheme Wireless sensor networks (WSN) is deployed for the well-organized communication of data. The WSN is designed considering increased life time, decreased power consumption, free of threats and attacks. The practical data obtained from the efficient system to model the ocean sediment dynamics are evaluated with remote

  10. Exploring a conceptual measurement instrument to assess performance predictors of small tourism business in South Africa

    Directory of Open Access Journals (Sweden)

    H. J.C. Van Zyl

    2008-12-01

    Full Text Available Purpose: The present study was set out to develop a model of entrepreneurial leadership that can recognize success factors of the owners of small and micro tourism enterprises within the South African context. The study attempts to combine various reliable and valid measurement instruments together, in conceptualising a more comprehensive and unified model that could test the nature and extent of the interrelationships between entrepreneurial leadership, market orientation, relationship marketing orientation and small tourism performance identified in a previous study by Van Zyl and Mathur-Helm (2007. Hence, a complex measurement instrument was conceptually constructed by the present study. Problem investigated: The Van Zyl and Mathur-Helm's (2007 study found that entrepreneurial leadership could best be described through a combination of distinct components. Hence the following instruments, entrepreneurial proclivity, ethical orientation, revised self-leadership, market orientation and relationship marketing orientation, with wide ranging dimensions of entrepreneurship, tourism, marketing and leadership, were brought together in formulating a comprehensive and complex measurement instrument. Methodology: It is a descriptive and a theoretical article that conceptually describes the development of a complex measurement instrument and thus secondary data from previous studies are used as comparative analysis for discussions and examinations. Implications: The paper recommends implications for South Africa's small tourism businesses, the government and the training institutions, by suggesting a model of performance predictors that can measure entrepreneurial leadership and can distinguish between successful (performing and unsuccessful (non-performing owner-managers of such ventures. Moreover, the instrument is aimed at providing insights into the kind of skills that a particular entrepreneurial leader and / or an owner manager of a small tourism

  11. Instrumental measurement of beer taste attributes using an electronic tongue

    Energy Technology Data Exchange (ETDEWEB)

    Rudnitskaya, Alisa, E-mail: alisa.rudnitskaya@gmail.com [Chemistry Department, University of Aveiro, Aveiro (Portugal); Laboratory of Chemical Sensors, Chemistry Department, St. Petersburg University, St. Petersburg (Russian Federation); Polshin, Evgeny [Laboratory of Chemical Sensors, Chemistry Department, St. Petersburg University, St. Petersburg (Russian Federation); BIOSYST/MeBioS, Catholic University of Leuven, W. De Croylaan 42, B-3001 Leuven (Belgium); Kirsanov, Dmitry [Laboratory of Chemical Sensors, Chemistry Department, St. Petersburg University, St. Petersburg (Russian Federation); Lammertyn, Jeroen; Nicolai, Bart [BIOSYST/MeBioS, Catholic University of Leuven, W. De Croylaan 42, B-3001 Leuven (Belgium); Saison, Daan; Delvaux, Freddy R.; Delvaux, Filip [Centre for Malting and Brewing Sciences, Katholieke Universiteit Leuven, Heverelee (Belgium); Legin, Andrey [Laboratory of Chemical Sensors, Chemistry Department, St. Petersburg University, St. Petersburg (Russian Federation)

    2009-07-30

    The present study deals with the evaluation of the electronic tongue multisensor system as an analytical tool for the rapid assessment of taste and flavour of beer. Fifty samples of Belgian and Dutch beers of different types (lager beers, ales, wheat beers, etc.), which were characterized with respect to the sensory properties, were measured using the electronic tongue (ET) based on potentiometric chemical sensors developed in Laboratory of Chemical Sensors of St. Petersburg University. The analysis of the sensory data and the calculation of the compromise average scores was made using STATIS. The beer samples were discriminated using both sensory panel and ET data based on PCA, and both data sets were compared using Canonical Correlation Analysis. The ET data were related to the sensory beer attributes using Partial Least Square regression for each attribute separately. Validation was done based on a test set comprising one-third of all samples. The ET was capable of predicting with good precision 20 sensory attributes of beer including such as bitter, sweet, sour, fruity, caramel, artificial, burnt, intensity and body.

  12. Magneto-optic Doppler analyzer: a new instrument to measure mesopause winds

    Science.gov (United States)

    Williams, Bifford P.; Tomczyk, Steven

    1996-11-01

    The magneto-optic Doppler analyzer (MODA) is a new type of passive optical instrument that one can use to measure the Doppler shift of the sodium nightglow emitted at approximately 91 km near the mesopause. From this measurement, horizontal wind signatures are inferred. The MODA is based on a sodium vapor magneto-optic filter that provides inherent wavelength stability at a low cost. The instrument has been used to take nightly zonal and meridional wind measurements since October 1994 at Niwot Ridge, Colorado (40 N, 105 W). We obtained an internally consistent wind signal and measured the semidiurnal tide for several seasons.

  13. A high sampling rate digital holographic imager instrument for the in situ measurements of hydrometeors

    Science.gov (United States)

    Kaikkonen, Ville A.; Mäkynen, Anssi J.

    2016-06-01

    A novel digital in-line holographic imaging instrument designed for acquiring properties of individual hydrometeors in situ is presented. The instrument has a large measurement volume of 670 cm3. This combined with fast frame rate imaging and software controlled multi-exposure capabilities results in a representative sampling of rain and snowfall events. Hydrometeors are measured and analyzed from the in-focus images with microscopic resolution, and their 3D locations inside the measurement volume are determined. The instrument is designed to operate in cold climates and to produce reliable measurements also during strong winds. The imaging rate of the instrument was designed to be adequately high to observe the dynamic nature of rain and snow falls. By recording multi-exposure holograms, the effective frame rate can be increased. This allows the measurements of the velocities of the fast-falling hydrometeors. The instrument and the hologram processing are described; as well as results from laboratory tests and the first field measurements are shown. As a result, the resolving power of the instrument was measured to vary between 11 and 18 microns inside the measurement volume near the center of the field-of-view. Velocity vectors were measured both from multi-exposure and high frame rate holograms. The measured velocities ranged from 0.1 to 4 m/s. In addition, the projections of a flat-shaped and rotating snowflake imaged at different locations inside the measurement volume demonstrated the possibility to estimate the shape of the hydrometeor from multiple viewing angles.

  14. A systematic review of instruments that measure attitudes toward homosexual men.

    Science.gov (United States)

    Grey, Jeremy A; Robinson, Beatrice Bean E; Coleman, Eli; Bockting, Walter O

    2013-01-01

    Scientific interest in the measurement of homophobia and internalized homophobia has grown over the past 30 years, and new instruments and terms have emerged. To help researchers with the challenging task of identifying appropriate measures for studies in sexual-minority health, we reviewed measures of homophobia published in the academic literature from 1970 to 2012. Instruments that measured attitudes toward male homosexuals/homosexuality or measured homosexuals' internalized attitudes toward homosexuality were identified using measurement manuals and a systematic review. A total of 23 instruments met criteria for inclusion, and their features were summarized and compared. All 23 instruments met minimal criteria for adequate scale construction, including scale development, sampling, reliability, and evidence of validity. Validity evidence was diverse and was categorized as interaction with gay men, HIV/AIDS variables, mental health, and conservative religious or political beliefs. Homophobia was additionally correlated with authoritarianism and bias, gender ideology, gender differences, and reactions to homosexual stimuli. Internalized homophobia was validated by examining relationships with disclosing one's homosexuality and level of homosexual identity development. We hope this review will make the process of instrument selection more efficient by allowing researchers to easily locate, evaluate, and choose the proper measure based on their research question and population of interest.

  15. A comparison of measurement concepts across physical science and social science domains: instrument design, calibration, and measurement

    International Nuclear Information System (INIS)

    Is there a framework common to measurement in both physical and social sciences? The answer to this question would determine to an important extent the possibility of building a shared measurement-related body of knowledge across these traditionally separate domains. In this paper, we outline a framework of the processes involved in the construction and use of measures that includes instrument design, instrument calibration, and ultimately measurement using the instrument. A comparison of these steps across the two domains reveals both (a) formal parallelism, and (b) important differences in the way calibration is intended and implemented. We examine the similarities and differences to determine whether this is a case of irreducible difference, or whether the similarities are such that measurement in the two domains can be viewed within a single conceptualization

  16. Measuring acoustic energy density in microchannel acoustophoresis using a simple and rapid light-intensity method.

    Science.gov (United States)

    Barnkob, Rune; Iranmanesh, Ida; Wiklund, Martin; Bruus, Henrik

    2012-07-01

    We present a simple and rapid method for measuring the acoustic energy density in microchannel acoustophoresis based on light-intensity measurements of a suspension of particles. The method relies on the assumption that each particle in the suspension undergoes single-particle acoustophoresis. It is validated by the single-particle tracking method, and we show by proper re-scaling that the re-scaled light intensity plotted versus re-scaled time falls on a universal curve. The method allows for analysis of moderate-resolution images in the concentration range encountered in typical experiments, and it is an attractive alternative to particle tracking and particle image velocimetry for quantifying acoustophoretic performance in microchannels. PMID:22522812

  17. Phased Acoustic Array Measurements of a 5.75 Percent Hybrid Wing Body Aircraft

    Science.gov (United States)

    Burnside, Nathan J.; Horne, William C.; Elmer, Kevin R.; Cheng, Rui; Brusniak, Leon

    2016-01-01

    Detailed acoustic measurements of the noise from the leading-edge Krueger flap of a 5.75 percent Hybrid Wing Body (HWB) aircraft model were recently acquired with a traversing phased microphone array in the AEDC NFAC (Arnold Engineering Development Complex, National Full Scale Aerodynamics Complex) 40- by 80-Foot Wind Tunnel at NASA Ames Research Center. The spatial resolution of the array was sufficient to distinguish between individual support brackets over the full-scale frequency range of 100 to 2875 Hertz. For conditions representative of landing and take-off configuration, the noise from the brackets dominated other sources near the leading edge. Inclusion of flight-like brackets for select conditions highlights the importance of including the correct number of leading-edge high-lift device brackets with sufficient scale and fidelity. These measurements will support the development of new predictive models.

  18. Digital image processing of sectorial oscillations for acoustically levitated drops and surface tension measurement

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A type of non-axisymmetric oscillations of acoustically levitated drops is excited by modulating the ultrasound field at proper frequencies. These oscillations are recorded by a high speed camera and analyzed with a digital image processing method. They are demonstrated to be the third mode sectorial oscillations, and their frequencies are found to decrease with the increase of equatorial radius of the drops, which can be described by a modified Rayleigh equation. These oscillations decay exponentially after the cessation of ultrasound field modulation. The decaying rates agree reasonably with Lamb’s prediction. The rotating rate of the drops accompanying the shape oscillations is found to be less than 1.5 rounds per second. The surface tension of aqueous ethanol has been measured according to the modified Rayleigh equation. The results agree well with previous reports, which demonstrates the possible application of this kind of sectorial oscillations in noncontact measurement of liquid surface tension.

  19. An innovative acoustic sensor for in-pile fission gas composition measurements

    International Nuclear Information System (INIS)

    In this article we propose a new method able to determine the fission gas composition using in situ ultrasonic waves measurements. To do so an acoustic resonator was connected to a fuel rodlet, in order to perform speed of sound measurements of gas mixture (Helium and fission gases) inside the plenum. By using a dedicated signal processing the peaks due to resonant frequencies inside the gas mixture were successfully extracted from the output signal. From these data, the variations of helium and fission gas molar fraction were calculated using an adapted virial state equation. It will be proved that these data provide important information about the kinetics of gas release and about the effects of high neutron and gamma irradiation on piezo-ceramic sensors. (authors)

  20. Rocket-borne measurements of electron temperature and density with the Electron Retarding Potential Analyzer instrument

    Science.gov (United States)

    Cohen, I. J.; Widholm, M.; Lessard, M. R.; Riley, P.; Heavisides, J.; Moen, J. I.; Clausen, L. B. N.; Bekkeng, T. A.

    2016-07-01

    Determining electron temperature in the ionosphere is a fundamentally important measurement for space science. Obtaining measurements of electron temperatures at high altitudes (>700 km) is difficult because of limitations on ground-based radar and classic spacecraft instrumentation. In light of these limitations, the rocket-borne Electron Retarding Potential Analyzer (ERPA) was developed to allow for accurate in situ measurement of ionospheric electron temperature with a simple and low-resource instrument. The compact ERPA, a traditional retarding potential analyzer with multiple baffle collimators, allows for a straightforward calculation of electron temperature. Since its first mission in 2004, it has amassed significant flight heritage and obtained data used in multiple studies investigating a myriad of phenomena related to magnetosphere-ionosphere coupling. In addition to highlighting the scientific contributions of the ERPA instrument, this paper outlines its theory and operation, the methodology used to obtain electron temperature measurements, and a comparative study suggesting that the ERPA can also provide electron density measurements.