WorldWideScience

Sample records for acoustic measuring instruments

  1. Ares I Scale Model Acoustic Tests Instrumentation for Acoustic and Pressure Measurements

    Science.gov (United States)

    Vargas, Magda B.; Counter, Douglas D.

    2011-01-01

    The Ares I Scale Model Acoustic Test (ASMAT) was a development test performed at the Marshall Space Flight Center (MSFC) East Test Area (ETA) Test Stand 116. The test article included a 5% scale Ares I vehicle model and tower mounted on the Mobile Launcher. Acoustic and pressure data were measured by approximately 200 instruments located throughout the test article. There were four primary ASMAT instrument suites: ignition overpressure (IOP), lift-off acoustics (LOA), ground acoustics (GA), and spatial correlation (SC). Each instrumentation suite incorporated different sensor models which were selected based upon measurement requirements. These requirements included the type of measurement, exposure to the environment, instrumentation check-outs and data acquisition. The sensors were attached to the test article using different mounts and brackets dependent upon the location of the sensor. This presentation addresses the observed effect of the sensors and mounts on the acoustic and pressure measurements.

  2. Ares I Scale Model Acoustic Test Instrumentation for Acoustic and Pressure Measurements

    Science.gov (United States)

    Vargas, Magda B.; Counter, Douglas

    2011-01-01

    Ares I Scale Model Acoustic Test (ASMAT) is a 5% scale model test of the Ares I vehicle, launch pad and support structures conducted at MSFC to verify acoustic and ignition environments and evaluate water suppression systems Test design considerations 5% measurements must be scaled to full scale requiring high frequency measurements Users had different frequencies of interest Acoustics: 200 - 2,000 Hz full scale equals 4,000 - 40,000 Hz model scale Ignition Transient: 0 - 100 Hz full scale equals 0 - 2,000 Hz model scale Environment exposure Weather exposure: heat, humidity, thunderstorms, rain, cold and snow Test environments: Plume impingement heat and pressure, and water deluge impingement Several types of sensors were used to measure the environments Different instrument mounts were used according to the location and exposure to the environment This presentation addresses the observed effects of the selected sensors and mount design on the acoustic and pressure measurements

  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. 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.

  6. Wireless Acoustic Measurement System

    Science.gov (United States)

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

    2007-01-01

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

  7. 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...

  8. 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.

  9. Software-based acoustical measurements

    CERN Document Server

    Miyara, Federico

    2017-01-01

    This textbook provides a detailed introduction to the use of software in combination with simple and economical hardware (a sound level meter with calibrated AC output and a digital recording system) to obtain sophisticated measurements usually requiring expensive equipment. It emphasizes the use of free, open source, and multiplatform software. Many commercial acoustical measurement systems use software algorithms as an integral component; however the methods are not disclosed. This book enables the reader to develop useful algorithms and provides insight into the use of digital audio editing tools to document features in the signal. Topics covered include acoustical measurement principles, in-depth critical study of uncertainty applied to acoustical measurements, digital signal processing from the basics, and metrologically-oriented spectral and statistical analysis of signals. The student will gain a deep understanding of the use of software for measurement purposes; the ability to implement software-based...

  10. 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.

  11. 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.

  12. Wind turbines acoustic measurements

    Science.gov (United States)

    Trematerra, Amelia; Iannace, Gino

    2017-07-01

    The importance of wind turbines has increased over the last few years throughout the European Community. The European energy policy guidelines state that for the year 2020 20% of all energy must be produced by alternative energy sources. Wind turbines are an important type of energy production without petrol. A wind speed in a range from 2.5 m/s to 25.0 m/s is needed. One of the obstacles to the widespread diffusion of wind turbine is noise generation. This work presents some noise measurements of wind turbines in the South of Italy, and discusses the noise problems for the people living near wind farms.

  13. 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

  14. 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.

  15. 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.

  16. ACOUSTIC MEASUREMENTS BUBBLES IN BIOLOGICAL TIESSURE

    Institute of Scientific and Technical Information of China (English)

    CHAHINE Georges L.; TANGUAY Michel; LORAINE Greg

    2009-01-01

    An acoustic based instrument,the ABS Acoustic Bubble Spectrometer(R)(C)(ABS),was investigated for the detection and quantification of bubbles in biological media.These include viscoelastic media(blood),materials of varying density(bone in tissue),non-homogenous distribution of bubbles(intravenous bubbly flow),and bubbles migrating in tissue(decompression sickness,DCS).The performance of the ABS was demonstrated in a series of laboratory experiments.Validation of the code was performed using a viscoelastic polymer solution,Polyox,in which the bubble size distribution and void fraction were determined by ABS measurements and with image analysis of high speed videos.These tests showed that the accuracy of the ABS was not significantly affected by viscoelasticity for bubbles smaller than 200 microns.The ABS detection and measurement of non-homogenous bubble distributions was demonstrated using a bubbly flow through a simulated vein surrounded by tissue.The scatter of acoustic signals due to bones in the acoustic pathway was also investigated.These in-vitro experiments were done using meat(beef)as a tissue simulant.Decompression experiments were done using beef meat which was held underwater at high pressure(9.9 atm)then rapidly decompressed.Bubble size distributions and void fraction calculations in these experiments were then validated using image analysis of high speed video.In addition,preliminary experiments were performed with the US Navy Medical Research Center,demonstrating the utility of the modified ABS system in detecting the evolution of bubbles in swine undergoing decompression sickness(DCS).These results indicate that the ABS may be used to detect and quantify the evolution of bubbles in-vivo and aid in the monitoring of DCS.

  17. Acoustic sensors for fission gas characterization: R and D skills devoted to innovative instrumentation in MTR, non-destructive devices in hot lab facilities and specific transducers for measurements of LWR rods in nuclear plants

    Energy Technology Data Exchange (ETDEWEB)

    Ferrandis, J.Y.; Leveque, G.; Rosenkrantz, E.; Augereau, F.; Combette, P. [University Montpellier, IES, UMR 5214, F-34000, Montpellier (France); CNRS, IES, UMR 5214, F-34000, Montpellier (France)

    2015-07-01

    First of all, we will present the main principle of the method. A piezoelectric transducer, driven by a pulse generator, generates the acoustic waves in a cavity that may be the fuel rod or a chamber connected to an instrumented rod. The composition determination consists in measuring the time of flight of the acoustic signal emitted. The pressure can be estimated by a calibration process, above the measurement of the amplitude of the signal. Two projects will then be detailed. The first project consists in the development of advanced instrumentation for in-pile experiments in Material Testing Reactor. It constitutes a main goal for the improvement of the nuclear fuel behavior knowledge. This acoustic method was tested with success during a first experiment called REMORA 3, and the results were used to differentiate helium and fission gas release kinetics under transient operating conditions. This experiment was lead at OSIRIS reactor (CEA Saclay, France). As a first step of the development program, we performed in-pile tests on the most sensitive component, i.e., the piezoelectric transducer. For this purpose, the active part of this sensor has been qualified on gamma and neutron radiations and at high temperature. Various industrial piezo-ceramics were exposed to a high activity Cobalt source for few days. The cumulated dose was ranged from 50 kGy up to 2 MGy. Next, these devices were placed inside a Material Test Reactor to investigate their reliability towards neutron fluence. The final fluence after 150 days of irradiation was up to 1.6.10{sup 21}n/cm{sup 2} (for thermal neutron). Irreversible variations have been measured. Next, a specific sensor has been implemented on an instrumented fuel rod and tested in the frame of a REMORA 3 Irradiation test. It was the first experiment under high mixed, temperature neutron and gamma flux. A first irradiation phase took place in March 2010 in the OSIRIS reactor and in November 2010 for the second step of the

  18. Instruments and methods acoustic televiewer logging in glacier boreholes

    Science.gov (United States)

    Morin, R.H.; Descamps, G.E.; Cecil, L.D.

    2000-01-01

    The acoustic televiewer is a geophysical logging instrument that is deployed in a water-filled borehole and operated while trolling. It generates a digital, magnetically oriented image of the borehole wall that is developed from the amplitudes and transit times of acoustic waves emitted from the tool and reflected at the water-wall interface. The transit-time data are also converted to radial distances, from which cross-sectional views of the borehole shape can be constructed. Because the televiewer is equipped with both a three-component magnetometer and a two-component inclinometer, the borehole's trajectory in space is continuously recorded as well. This instrument is routinely used in mining and hydrogeologic applications, but in this investigation it was deployed in two boreholes drilled into Upper Fremont Glacier, Wyoming, U.S.A. The acoustic images recorded in this glacial setting are not as clear as those typically obtained in rocks, due to a lower reflection coefficient for water and ice than for water and rock. Results indicate that the depth and orientation of features intersecting the boreholes can be determined, but that interpreting their physical nature is problematic and requires corroborating information from inspection of cores. Nevertheless, these data can provide some insight into englacial structural characteristics. Additional information derived from the cross-sectional geometry of the borehole, as well as from its trajectory, may also be useful in studies concerned with stress patterns and deformation processes.

  19. Acoustic Communications Measurement Systems (ACOMMS)

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Design and develop adaptive signal processing techniques to improve underwater acoustic communications and networking. Phase coherent and incoherent signal...

  20. 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...

  1. Acoustic power measurements of oscillating flames

    NARCIS (Netherlands)

    Valk, M.

    1981-01-01

    The acoustic power of an oscillating flame is measured. A turbulent premixed propane/air flame is situated near a pressure antinode of a standing wave in a laboratory combustion chamber. This standing wave is generated by a piston. The fluctuating heat release of the flame will supply acoustic power

  2. Acoustic power measurements of oscillating flames

    NARCIS (Netherlands)

    Valk, M.

    1981-01-01

    The acoustic power of an oscillating flame is measured. A turbulent premixed propane/air flame is situated near a pressure antinode of a standing wave in a laboratory combustion chamber. This standing wave is generated by a piston. The fluctuating heat release of the flame will supply acoustic power

  3. Eliminating transducer distortion in acoustic measurements

    DEFF Research Database (Denmark)

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

    2014-01-01

    This paper investigates the in uence of nonlinear components that contaminate the linear response of acoustic transducer, and presents a method for eliminating the in uence of nonlinearities in acoustic measurements. The method is evaluated on simulated as well as experimental data, and is shown...

  4. 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)

  5. 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.

  6. Advances in non-invasive measures of vocal acoustics.

    Science.gov (United States)

    LaBlance, G R; Steckol, K F; Cooper, M H

    1991-10-01

    Objective assessment of vocal pitch, loudness, and quality is a crucial adjunct to endoscopy in the diagnosis and treatment of vocal pathology. Historically, this assessment was made through subjective, perceptual measures that were questionable in terms of validity and reliability. Recent advances in electronic technology now permit objective analysis of the acoustic characteristics of voice. Kay Elemetric's Visi-Pitch, DSP 5500 Digital Spectrograph, and Nasometer are representative of these new instruments and are used as illustrations in the discussion of the assessment of speech acoustics.

  7. 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...

  8. Mechanical design and vibro-acoustic testing of ultrathin carbon foils for a spacecraft instrument

    Energy Technology Data Exchange (ETDEWEB)

    Bernardin, John D [Los Alamos National Laboratory; Baca, Allen G [SNL

    2009-01-01

    IBEX-Hi is an electrostatic analyzer spacecraft instrument designed to measure the energy and flux distribution of energetic neutral atoms (ENAs) emanating from the interaction zone between the Earth's solar system and the Milky Way galaxy. A key element to this electro-optic instrument is an array of fourteen carbon foils that are used to ionize the ENAs. The foils are comprised of an ultrathin (50-100 {angstrom} thick) layer of carbon suspended across the surface of an electroformed Nickel wire screen, which in turn is held taught by a metal frame holder. The electro formed orthogonal screen has square wire elements, 12.7 {micro}m thick, with a pitch of 131.1 wires/cm. Each foil holder has an open aperture approximately 5 cm by 2.5 cm. Designing and implementing foil holders with such a large surface area has not been attempted for spaceflight in the past and has proven to be extremely challenging. The delicate carbon foils are subject to fatigue failure from the large acoustic and vibration loads that they will be exposed to during launch of the spacecraft. This paper describes the evolution of the foil holder design from previous space instrument applications to a flight-like IBEX-Hi prototype. Vibro-acoustic qualification tests of the IBEX-Hi prototype instrument and the resulting failure of several foils are summarized. This is followed by a discussion of iterative foil holder design modifications and laser vibrometer modal testing to support future fatigue failure analyses, along with additional acoustic testing of the IBEX-Hi prototype instrument. The results of these design and testing activities are merged and the resulting flight-like foil holder assembly is proposed.

  9. 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.

  10. 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

  11. Measuring Norwegian dialect distances using acoustic features

    NARCIS (Netherlands)

    Heeringa, Wilbert; Johnson, Keith; Gooskens, Charlotte

    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

  12. Force Measurements in Vibration and Acoustic Tests

    Science.gov (United States)

    Scharton, T. D.

    1996-01-01

    The advent of triaxial, piezoelectric force gages and the associated signal processing is a precursor to several dynamics testing innovations. This new technology is applicable to spacecraft programs that JPL manages. An application of force measurement is force limiting (when testing spacecraft in random vibration tests). Base-drive and acoustic modal testing is a potential application.

  13. 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.

  14. Acoustic vs Interferometric Measurements of Lightning

    Science.gov (United States)

    Arechiga, R. O.; Erives, H.; Sonnenfeld, R. G.; Stanley, M. A.; Rison, W.; Thomas, R. J.; Edens, H. E.; Lapierre, J. L.; Stock, M.; Jensen, D.; Morris, K.

    2015-12-01

    During the summer of 2015 we acquired acoustic and RF data on severalflashes from thunderstorms over Fort Morgan CO. and Langmuir Laboratoryin the Magdalena mountains of central New Mexico. The acoustic arrayswere located at a distance of roughly 150 m from the interferometers.Lightning mapping array and slow antenna data were also obtained. Theacoustic arrays consist of arrays of five audio-range and six infrasoundmicrophones operating at 50 KHz and 1 KHz respectively. The lightninginterferometer at Fort Morgan CO. consists of three flat-plate, 13" diameterantennas at the vertices of an equilateral 50 m per side triangle. Theinterferometer at Langmuir Laboratory consists of three 13" dishes separatedby about 15 m. Both interferometers, operating at 180 Megasamples persecond, use the analysis software and digitizer hardware pioneered byStanley, Stock et al. The high data rate allows for excellent spatialresolution of high speed (and typically high current) processes such asK-changes, return strokes and dart-leaders. In previous studies, we haveshown the usefulness of acoustic recordings to locate thunder sources aswell as infrasound pulses from lightning. This work will present acomparison of Acoustic and Interferometric measurements from lightning,using some interesting flashes, including a positive cloud to ground,that occurred in these campaigns.

  15. An acoustic mode measurement technique

    Science.gov (United States)

    Joppa, P. D.

    1984-10-01

    Turbomachinery noise propagates in aircraft jet engine ducts in a complicated manner. Measurement of this propagation is useful both to identify source mechanisms and to design efficient linings. A practical method of making these measurements has been developed, using linear arrays of equally spaced microphones mounted flush with the duct wall. Circumferential or axial arrays are analyzed by spatial Fourier transform, giving sound level as a function of spinning order or axial wavenumber respectively. Complex demodulation is used to acquire data in a modest bandwidth around a high frequency of interest. A joint NASA/Boeing test of the system used 32 microphones in a JT15D turbofan engine inlet. A 400-Hz bandwidth centered at blade passage frequency and at half blade passage frequency was studied. The theoretically predicted modes were clearly seen at blade passage frequency; broadband noise at half blade passage frequency was biased towards modes corotating with the fan. Interference between similar modes was not a significant problem. A lining design study indicated a 15 percent improvement in lining efficiency was possible when mode data were used, for this particular engine. The technique has proven reliable and useful for source diagnostics and lining design.

  16. 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.

  17. On the cutoff frequency of clarinet-like instruments: Geometrical vs acoustical regularity

    CERN Document Server

    Moers, Elise

    2011-01-01

    A characteristic of woodwind instruments is the cutoff frequency of their tone-hole lattice. Benade proposed a practical definition using the measurement of the input impedance, for which at least two frequency bands appear. The first one is a stop band, while the second is a pass band. The value of this frequency, which is a global quantity, depends on the whole geometry of the instrument, but is rather independent on the fingering. This seems to justify the consideration of a woodwind with several open holes as a periodic lattice. However the holes on a clarinet are very irregular. The paper investigates the question of the acoustical regularity: an acoustically regular lattice of tone holes is defined as a lattice built with T-shaped cells of equal eigenfrequencies. Then the paper discusses the possibility of division of a real lattice into cells of equal eigenfrequencies. It is shown that it is not straightforward but possible, explaining the apparent paradox of the Benade theory. When considering the ope...

  18. Measuring acoustic emissions in an avalanche slope

    Science.gov (United States)

    Reiweger, Ingrid; Schweizer, Jürg

    2014-05-01

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

  19. Intelligent sensing, instrumentation and measurements

    CERN Document Server

    Mukhopadhyay, Subhas Chandra

    2013-01-01

      “Intelligent Sensing, Instrumentation and Measurements” addresses issues towards the development of sensor nodes for wireless Sensor Networks. The fundamentals of sensors, interfacing, power supplies, configuration of sensor node, and GUI development are covered. The book will be useful for engineers and researchers in the field ,especially for higher undergraduate and postgraduate students as well as practitioners working on the development of Wireless Sensor Networks or Smart Sensors.

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

    DEFF Research Database (Denmark)

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

    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...... increases to more than 3 m. The Doppler instruments (Nortek) are placed on a vertical pole about 2 m off the right bank at three fixed elevations above the streambed (0.3, 0.6, and 1.3 m); the beams point horizontally towards the left bank perpendicularly to the average flow direction. At each depth...... it records the stage. The monthly control measurements made by the water authority office are made with an ADCP-instrument (Streampro, acoustic Doppler current profiler) which is pulled across the stream next to the in situ Doppler instruments. As part of the present project supplementary ADCP-data have been...

  1. 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 (<1 m) line to the seafloor. Contained within the float is an accelerometer that records the tilt of the float in response to passing waves. During two field trials totaling 358 h, we confirmed the accuracy and precision of URSKI 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.

  2. 40 CFR 201.22 - Measurement instrumentation.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Measurement instrumentation. 201.22 Section 201.22 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) NOISE ABATEMENT... Criteria § 201.22 Measurement instrumentation. (a) A sound level meter or alternate sound level...

  3. Acoustic measuring techniques for suspended sediment

    Science.gov (United States)

    Gruber, P.; Felix, D.; Storti, G.; Lattuada, M.; Fleckenstein, P.; Deschwanden, F.

    2016-11-01

    Acoustic signals can be used in various ways for suspended sediment monitoring. One possibility which lends itself particularly well in the context of hydropower plants (HPPs), is to use installations for acoustic discharge measurement (ADM). Such installations already exist at waterways of many HPPs. Similar to certain turbidimeters, the attenuation of the forward scattered signal travelling through the water-sediment mixture is correlated with suspended sediment concentration (SSC). This correlation can be based on reference SSCs, e.g. from gravimetric analyses of bottle samples. Without the need of additional sensors and practically maintenance-free, this method is used successfully in the HPP Fieschertal to warn the HPP operator of high SSC to prevent excessive turbine abrasion. Acoustic methods and systems that allow for estimating both SSC and particle size distribution (PSD) are under development. The simultaneous determination of SSC and PSD is not possible using a single frequency. Therefore, multi-frequency approaches are investigated for generally scattered signals. When backscattered signals are used, a stronger frequency dependency can be exploited. However, the reliable simultaneous determination of particle size (and distribution) and concentration is still a major challenge due to a low signal-to-noise ratio and an ill- posed problem of estimating concentration and size from recorded signals. The optimal setup configuration (angles, frequencies) for such a system is not unique and further investigations are recommended.

  4. 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

  5. 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.

  6. A comparison between acoustic mode measurements and acoustic finite element analysis performed for SAAB SF 340

    Science.gov (United States)

    Goeransson, P.; Green, I.

    1986-03-01

    In order to verify an acoustic finite element package, measured and calculated eigenmodes and eigenfrequencies for Saab SF 340 cabin acoustics were compared. The measurements were performed in an acoustic mockup. For the analysis, a two dimensional model of the cross section of the fuselage was used. The comparison shows quite good agreement, the discrepancies being due to the representation of the flexible wall of the fuselage as rigid in the analysis.

  7. 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.

  8. Noninvasive fluid property measurements using acoustic methods.

    Science.gov (United States)

    Forbush, Michael; Chow, Humphrey; Chiao, James; Rose, Andrew

    2007-03-01

    The properties of a fluid are normally determined using invasive methods. These methods may lead to possibly contaminating or consuming the sample. When only very small amounts of a valuable sample exist, noninvasive measurement methods are preferred. The properties of fluids can then be used to deduce additional properties based on known relationships. In one case, the surface tension of a fluid may be used to determine the concentration of a fluid. The authors describe a measurement technique involving excitation of the surface of the fluid and the measurement of its response. An acoustic wave is used to both excite and monitor the surface of the liquid. This technique is used to determine the concentration of DMSO and water in solution, and the result determines the amount of fluid needed to deliver an accurate amount of solute in solution.

  9. 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.

  10. Fundamental Measurements and Instrumentation " CKM "

    Science.gov (United States)

    Morelos, A.; Engelfried, J.; Mata, J.; Torres, I.; Vazquez-Jauregui, E.

    2002-07-01

    The physics being pursued by CKM (E921) 1, an experiment recently approved at Fermilab, has as goal testing the description of CP Violation within the Standard model. Measuring the branching ratio of K+ [right arrow] pi+vv with 10% accuracy, we can extract the magnitude of Vtd with an overall precision (including theoretical uncertainties) of 10%. Within the collaboration, the experimental high energy physics group at IF-UASLP has the responsibility for designing, testing, and building two Ring Imaging Cherenkov detectors. The present status of the experiment is shown in this poster.

  11. 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)

  12. 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.

  13. Statistical study of color-measurement instrumentation.

    Science.gov (United States)

    Marcus, R T; Billmeyer, F W

    1974-06-01

    In a statistical study of the variability of instrumental color-measurement data, two instruments (a Kollmorgen KCS-40 colorimeter-abridged spectrophotometer and a General Electric Recording Spectrophotometer equipped with a Davidson and Hemmendinger digital tristimulus integrator) provided three modes of measurement. Ten samples were measured 48 times in each mode. Frequency distributions were constructed for several colorimetric quantities, including tristimulus values, chromaticity coordinates, and color differences from the mean. To allow study of the error involved in the measurement of color-difference pairs, three such pairs were included in the ten samples. The beneficial effects of averaging were quantified.

  14. Comparative performance of color-measuring instruments.

    Science.gov (United States)

    Billmeyer, F W

    1969-04-01

    The comparative performance of fifteen different color-measuring instruments was studied for precision (short-term repeatability) and accuracy of color measurement and of color difference measurement. For estimates of accuracy, a GE spectrophotometer was considered the referee instrument. The instruments tested included two integrating sphere spectrophotometers, six integrating sphere colorimeters (four of which were individually calibrated for close conformance to CIE coordinates), and seven 45 degrees / normal calorimeters (four of which were individually calibrated for close conformance to CIE coordinates). Up to fifty-three samples were measured, most of them several times, on each instrument. Paint panels, plastics, porcelain enamels, and ceramic tiles were among the samples used. Overall, the well-established IDL D-1 Signature Color-Eye colorimeter-abridged spectrophotometer and the Hunter D25 Color and Color Difference Meter demonstrated the best and next best performance, respectively, in all categories. Several other instruments, both well established and new, were outstanding in one or more respects. All production instruments tested gave generally satisfactory results.

  15. Identification of Acoustic-Vibratory System by Acoustic Measurement

    Directory of Open Access Journals (Sweden)

    Takuzo Iwatsubo

    1996-01-01

    Full Text Available A new method for reducing ill-conditioning in a class of identification problems is proposed. The key point of the method is that the identified vibration of the sound source is expressed as a superposition of vibration modes. The mathematical property of the coefficient matrix, the practical error expanding ratio, and the stochastic error expanding ratio are investigated in a numerical example. The mode-superposition method is shown to be an effective tool for acoustic-vibratory inverse analysis.

  16. Outdoor Synthetic Aperture Acoustic Ground Target Measurements

    Science.gov (United States)

    2010-04-19

    1341 (2003). [11] C. A. Dimarzio, T. Shi, F. J. Blonigen et al., “ Laser -Induced Acoustic Landmine Detection,” The Journal Of The Acoustical Society...High Frequency A/S Coupling For Ap Buried Landmine Detection Using Laser Doppler Vibrometers,” Proc. SPIE 5415(1), 35-41 (2004). [16] Bishop, S... Dolphin Echolocation Clicks For Target Discrimination,” The Journal Of The Acoustical Society Of America 124(1), 657-666 (2008). [20] Y. Nakamura

  17. 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…

  18. 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.

  19. Measurement control program for NDA instruments

    Energy Technology Data Exchange (ETDEWEB)

    Hsue, S.T.; Marks, T.

    1983-01-01

    Measurement control checks for nondestructive assay instruments have been a constant and continuing concern at Los Alamos National Laboratory. This paper summarizes the evolution of the measurement control checks in the various high-resolution gamma systems we have developed. In-plant experiences with these systems and checks will be discussed. Based on these experiences, a set of measurement control checks is recommended for high-resolution gamma-ray systems.

  20. 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.

  1. 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

  2. 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.

  3. Measurement of the thermo-acoustic effect for acoustic neutrino detection

    Energy Technology Data Exchange (ETDEWEB)

    Heinen, Dirk; Cramer, Sascha; Laihem, Karim; Paul, Larissa; Wiebusch, Christopher [III. Physikalisches Institut, RWTH Aachen, D-52056 Aachen (Germany); Collaboration: IceCube-Collaboration

    2011-07-01

    Future neutrino telescopes with the aim to explore the extreme high energy region (E >10{sup 18} eV) require 1-2 orders of magnitude larger effective volumes compared to current optical detectors (IceCube 1 km{sup 3}). One possible approach is the thermo-acoustic detection of hadronic cascades from neutrino interactions. A main goal of the Aachen Acoustic Laboratory (AAL) is to study the thermo-acoustic effect under laboratory conditions and to develop appropriate detection methods. Central element is a large 3 m{sup 3} ice or water tank in which sensor and emitter elements are deployed. Thermo-acoustic signals are generated by a pulsed laser beam injected into the tank. In this talk we present the status of the setup and the measurement of laser induced thermo-acoustic sound waves.

  4. Instrument for measuring human biting force

    Science.gov (United States)

    Kopola, Harri K.; Mantyla, Olavi; Makiniemi, Matti; Mahonen, Kalevi; Virtanen, Kauko

    1995-02-01

    Alongside EMG activity, biting force is the primary parameter used for assessing the biting problems of dentulous patients and patients with dentures. In a highly conductive oral cavity, dielectric measurement methods are preferred, for safety reasons. The maximum biting force for patients with removable dentures is not more than 100 ... 300 N. We report here on an instrument developed for measuring human biting force which consists of three units: a mouthpiece, a signal processing and interface unit (SPI), and a PC. The mouthpiece comprises a sensor head of thickness 3.4 mm, width 20 mm and length 30 mm constructed of two stainless steel plates and with a fiber optic microbending sensor between them. This is connected to the SPI unit by a three-meter fiber optic cable, and the SPI unit to the PC by an RS connection. A computer program has been developed that includes measurement, display, zeroing, and calibration operations. The instrument measures biting force as a function of time and displays the time-dependent force profile and maximum force on a screen or plots it in hard copy. The dynamic measurement range of the mouthpiece is from 0 to 1000 N, and the resolution of the instrument is 10 N. The results of preliminary clinical measurements and repeatability tests are reported.

  5. 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.

  6. Multi-dimensional analysis of subjective acoustical ratings and acoustical measures in existing concert halls

    Science.gov (United States)

    Okano, Toshiyuki

    2004-05-01

    Correlations between subjective acoustical ratings and hall-averaged values of acoustical measures are studied among existing worldwide major concert halls. It was shown that the classified acoustical ratings by Beranek [Concert and Opera Halls, How They Sound (ASA, 1996)] are discriminated correctly by combining binaural quality index (BQI) with some other acoustical measures. BQI is determined by the arithmetic average of inter-aural cross correlation coefficient in three octave bands of 500, 1000, and 2000 Hz, subtracted from unity, calculated from the early 80-ms part of binaural impulse response. Considering that the upper limit value of BQI not to cause disturbing image shift is approximately 0.85 at individual seat [Okano, J. Acoust. Soc. Am. 2219-2230 (2000)], the values of 0.6 or higher in hall averaged value of BQI, 0.85 or smaller in individual seat value of BQI, and approximately 5 dB or higher in strength factor at middle frequencies are proposed as design objectives to attain a high acoustical quality. It should be provided that other acoustical measures are also optimized. These target values will be very effective in studying room shape of halls, using scale models or computer models.

  7. Measurement of the Laser induced thermo-acoustic effect for acoustic neutrino detection

    Energy Technology Data Exchange (ETDEWEB)

    Heinen, Dirk; Laihem, Karim; Paul, Larissa; Scheel, Maximilian; Wiebusch, Christopher [III. Physikalisches Institut, RWTH Aachen (Germany); Collaboration: IceCube-Collaboration

    2012-07-01

    Future neutrino telescopes with the aim to explore the extreme high energy region (above 10{sup 18} eV) require 2-3 orders of magnitude larger effective volumes compared to current optical detectors (IceCube 1 km{sup 3}). One possible approach is the acoustic detection of the thermo-acoustic pressure wave generated by hadronic cascades in neutrino interactions. A major goal of the Aachen Acoustic Laboratory (AAL) is to study the thermo-acoustic effect under laboratory conditions and to develop appropriate detection methods. Central element is a large volume (3 m{sup 3}) of ice or water in which sensor and emitter elements are deployed. Thermo-acoustic signals are generated by a pulsed laser beam injected into the volume. In this talk we present the experimental setup and measurements of the laser induced thermo-acoustic sound waves. In addition to these laboratory measurements an outlook on future in-situ measurements of acoustic signals in ice will be given.

  8. 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.

  9. Instrument for measurement of low exposure rates

    Energy Technology Data Exchange (ETDEWEB)

    Baeckstroem, A.; Lindhe, J.C.

    1974-02-01

    An instrument for measurement of exposure rates between 0.1 and 20 R/h was fabricated. The instrument will be used in connection wtth radiation therapy of gynecologic cancer. A lithium-drifted silicon detector is used. The registered pulse information is treated in the instrument so that the exposure rate may be read directly in R/h. The instrument accumulates pulses during one second, and the repetition time is one second, The error is plus or minus 10% at 0.1 R/h, plus or minus 3% at 1 R/h and less than plus or minus 1% at 10 R/h. The repetition time may be altered to 10 sec. at calibration. This means that it is possible to measure 0.01 R/h with the accuracy 10% and 0.1 R/h with the accuracy 3%. The stability with time and temperature, linearity, energy dependence, direction dependence and lifetime was investigated. (SW

  10. Articulatory-acoustic vowel space: Associations between acoustic and perceptual measures of clear speech.

    Science.gov (United States)

    Whitfield, Jason A; Goberman, Alexander M

    2017-04-01

    The current investigation examined the relationship between perceptual ratings of speech clarity and acoustic measures of speech production. Included among the acoustic measures was the Articulatory-Acoustic Vowel Space (AAVS), which provides a measure of working formant space derived from continuously sampled formant trajectories in connected speech. Acoustic measures of articulation and listener ratings of speech clarity were obtained from habitual and clear speech samples produced by 10 neurologically healthy adults. Perceptual ratings of speech clarity were obtained from visual-analogue scale ratings and acoustic measures included the AAVS measure, articulation rate and percentage pause. Clear speech was characterised by a higher perceptual clarity rating, slower articulation rate, greater percentage pause and larger AAVS compared to habitual speech. Additionally, correlation analysis revealed a significant relationship between the perceptual clear speech effect and the relative clarity-related change in the AAVS and articulation rate measures. The current findings suggest that, along with speech rate measures, the recently introduced AAVS is sensitive to changes in speech clarity.

  11. Overview of hydro-acoustic current-measurement applications by the U.S. geological survey in Indiana

    Science.gov (United States)

    Morlock, Scott E.; Stewart, James A.

    1999-01-01

    The U.S. Geological Survey (USGS) maintains a network of 170 streamflow-gaging stations in Indiana to collect data from which continuous records of river discharges are produced. Traditionally, the discharge record from a station is produced by recording river stage and making periodic discharge measurements through a range of stage, then developing a relation between stage and discharge. Techniques that promise to increase data collection accuracy and efficiency include the use of hydro-acoustic instrumentation to measure river velocities. The velocity measurements are used to compute river discharge. In-situ applications of hydro-acoustic instruments by the USGS in Indiana include acoustic velocity meters (AVM's) at six streamflow-gaging stations and newly developed Doppler velocity meters (DVM's) at two stations. AVM's use reciprocal travel times of acoustic signals to measure average water velocities along acoustic paths, whereas DVM's use the Doppler shift of backscattered acoustic signals to compute water velocities. In addition to the in-situ applications, three acoustic Doppler current profilers (ADCP's) are used to make river-discharge measurements from moving boats at streamflow-gaging stations in Indiana. The USGS has designed and is testing an innovative unmanned platform from which to make ADCP discharge measurements.

  12. Ozone measurement systems: associated instrumentation and calibration

    Directory of Open Access Journals (Sweden)

    J. Bellido

    2006-01-01

    Full Text Available The harmful effects produced by ozone have lead to a vast regulation to define and establish the quality goals of ambient air, based on common methods and criteria. The surveillance nets of atmospheric pollution are worldwide extended systems and the applied technology for the ozone measurement is nowadays quite standardized. The aim of this paper is to give a general view of the most common systems used in the ozone measurement in ambient air from a practical point of view. The used instrumentation and the usual calibration methods will be described.

  13. JWST science instrument pupil alignment measurements

    Science.gov (United States)

    Kubalak, Dave; Sullivan, Joe; Ohl, Ray; Antonille, Scott; Beaton, Alexander; Coulter, Phillip; Hartig, George; Kelly, Doug; Lee, David; Maszkiewicz, Michael; Schweiger, Paul; Telfer, Randal; Te Plate, Maurice; Wells, Martyn

    2016-09-01

    NASA's James Webb Space Telescope (JWST) is a 6.5m diameter, segmented, deployable telescope for cryogenic IR space astronomy ( 40K). The JWST Observatory architecture includes the Optical Telescope Element (OTE) and the Integrated Science Instrument Module (ISIM) element that contains four science instruments (SI), including a guider. OSIM is a full field, cryogenic, optical simulator of the JWST OTE. It is the "Master Tool" for verifying the cryogenic alignment and optical performance of ISIM by providing simulated point source/star images to each of the four Science Instruments in ISIM. Included in OSIM is a Pupil Imaging Module (PIM) - a large format CCD used for measuring pupil alignment. Located at a virtual stop location within OSIM, the PIM records superimposed shadow images of pupil alignment reference (PAR) targets located in the OSIM and SI pupils. The OSIM Pupil Imaging Module was described by Brent Bos, et al, at SPIE in 2011 prior to ISIM testing. We have recently completed the third and final ISIM cryogenic performance verification test before ISIM was integrated with the OTE. In this paper, we describe PIM implementation, performance, and measurement results.

  14. 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.

  15. Acoustic temperature measurement in a rocket noise field.

    Science.gov (United States)

    Giraud, Jarom H; Gee, Kent L; Ellsworth, John E

    2010-05-01

    A 1 μm diameter platinum wire resistance thermometer has been used to measure temperature fluctuations generated during a static GEM-60 rocket motor test. Exact and small-signal relationships between acoustic pressure and acoustic temperature are derived in order to compare the temperature probe output with that of a 3.18 mm diameter condenser microphone. After preliminary plane wave tests yielded good agreement between the transducers within the temperature probe's ∼2 kHz bandwidth, comparison between the temperature probe and microphone data during the motor firing show that the ±∼3 K acoustic temperature fluctuations are a significant contributor to the total temperature variations.

  16. Thick Films acoustic sensors devoted to MTR environment measurements. Thick Films acoustic sensors devoted to Material Testing Reactor environment measurements

    Energy Technology Data Exchange (ETDEWEB)

    Very, F.; Rosenkrantz, E.; Combette, P.; Ferrandis, J.Y. [University Montpellier, IES, UMR 5214, F-34000, Montpellier (France); CNRS, IES, UMR 5214, F-34000, Montpellier (France); Fourmentel, D.; Destouches, C.; Villard, J.F. [CEA, DEN, Instrumentation Sensors and Dosimetry Laboratory, Cadarache, F-13108 St Paul lez Durance (France)

    2015-07-01

    The development of advanced instrumentation for in-pile experiments in Material Testing Reactor constitutes a main goal for the improvement of the nuclear fuel behavior knowledge. An acoustic method for fission gas release detection was tested with success during a first experiment called REMORA 3 in 2010 and 2011, and the results were used to differentiate helium and fission gas release kinetics under transient operating conditions. This experiment was lead at OSIRIS reactor (CEA Saclay, France). The maximal temperature on the sensor during the irradiation was about 150 deg. C. In this paper we present a thick film transducer produce by screen printing process. The screen printing of piezoelectric offers a wide range of possible applications for the development of acoustic sensors and piezoelectric structure for measurements in high temperature environment. We firstly produced a Lead Zirconate Titanate (PZT) based paste composed of Pz27 powder from Ferroperm, CF7575 glass, and organic solvent ESL 400. Likewise a Bismuth Titanate based paste synthesized in our laboratory was produced. With these inks we produced thick film up to 130 μm by screen printing process. Material properties characterizations of these thick-film resonators are essential for device design and applications. The piezoelectric coefficients d33 and pyro-electric P(T) coefficient are investigated. The highest P(T) and d33 are respectively 80 μC.m{sup -2}.K{sup -1} and 130 μC.N{sup -1} for the PZT transducer -which validates the fabrication process-. In view of the development of this transducer oriented for high temperature and irradiation environment, we investigated the electrical properties of the transducers for different ranges of frequencies and temperature - from 20 Hz up to 40 MHz between 30 and 400 deg. C. We highlight the evolution of the impedance response and piezoelectric parameters of screen printed piezoelectric structures on alumina. Shortly an irradiation will be realized in

  17. An improved instrumental characterization of mechanical and acoustic properties of crispy cellular solid food

    NARCIS (Netherlands)

    Vliet, T. van; Castro-Prada, E.M.; Luyten, H.; Lichtendonk, W.; Hamer, R.J.

    2007-01-01

    A detailed study was performed to simultaneously measure the mechanical and acoustic properties of crispy cellular solid foods. Different critical aspects are discussed in order to assess optimal test conditions. These are primarily data sampling rate, microphone positioning, frequency spectrum of i

  18. 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.

  19. Acoustic sensor for remote measuring of pressure

    Directory of Open Access Journals (Sweden)

    Kataev V. F.

    2008-04-01

    Full Text Available The paper deals with sensors based on delay lines on surface acoustic waves (SAW, having a receiving-emitting and a reflective interdigital transducers (IDT. The dependence of the reflection coefficient of SAW on type and intensity of the load was studied. The authors propose a composite delay line in which the phase of the reflection coefficient depends on the pressure. Pressure leads to a shift of the reflective IDT relative to the transceiver, because they are located on different substrates. The paper also presents functional diagrams of the interrogator.

  20. Advances in Fast Response Acoustically Derived Air Temperature Measurements

    Science.gov (United States)

    Bogoev, Ivan; Jacobsen, Larry; Horst, Thomas; Conrad, Benjamin

    2016-04-01

    Fast-response accurate air-temperature measurements are required when estimating turbulent fluxes of heat, water and carbon dioxide by open-path eddy-covariance technique. In comparison with contact thermometers like thermocouples, ultra-sonic thermometers do not suffer from solar radiation loading, water vapor condensation and evaporative cooling effects. Consequently they have the potential to provide more accurate true air temperature measurements. The absolute accuracy of the ultrasonic thermometer is limited by the following parameters: the distance between the transducer pairs, transducer delays associated with the electrical-acoustic signal conversion that vary with temperature, components of the wind vector that are normal to the ultrasonic paths, and humidity. The distance between the transducer pairs is commonly obtained by coordinate measuring machine. Improved accuracy demonstrated in this study results from increased stiffness in the anemometer head to better maintain the ultrasonic path-length distances. To further improve accuracy and account for changes in transducer delays and distance as a function of temperature, these parameters are characterized in a zero-wind chamber over the entire operating temperature range. When the sonic anemometer is combined with a co-located fast-response water vapor analyzer, like in the IRGASON instrument, speed of sound can be compensated for humidity effects on a point-by-point basis resulting in a true fast-response air temperature measurement. Laboratory test results show that when the above steps are implemented in the calibration of the ultrasonic thermometer air-temperature accuracy better than ±0.5 degrees Celsius can be achieved over the entire operating range. The approach is also validated in a field inter-comparison with an aspirated thermistor probe mounted in a radiation shield.

  1. On acoustic intensity measurements in the presence of mean flow

    Science.gov (United States)

    Munro, D. H.; Ingard, K. U.

    1979-01-01

    A theoretical analysis demonstrates that the technique of measuring acoustic intensity by means of cross correlation between nearby microphones cannot, in general, be extended to situations in which there is mean flow. However, it may be possible to use this technique to measure intensities in ducts with mean flow at frequencies below their cutoff frequencies.

  2. 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

  3. 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

  4. Measuring Lagrangian accelerations using an instrumented particle

    CERN Document Server

    Zimmermann, Robert; Gasteuil, Yoann; Volk, Romain; Pinton, Jean-François

    2012-01-01

    Accessing and characterizing a flow impose a number of constraints on the employed measurement techniques; in particular optical methods require transparent fluids and windows in the vessel. Whereas one can adapt apparatus, fluid and methods in the lab to these constraints, this is hardly possible for industrial mixers. We present in this article a novel measurement technique which is suitable for opaque or granular flows: an instrumented particle, which continuously transmits the force/acceleration acting on it as it is advected in a flow. Its density is adjustable for a wide range of fluids and because of its small size and its wireless data transmission, the system can be used both in industrial and scientific mixers allowing a better understanding of the flow within. We demonstrate the capabilities and precision of the particle by comparing its transmitted acceleration to alternative measurements, in particular in the case of a turbulent von K\\'arm\\'an flow. Our technique shows to be an efficient and fast...

  5. 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.

  6. 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.

  7. Reverberation chamber and its verification for acoustic measurements

    Directory of Open Access Journals (Sweden)

    Drabek Pavel

    2016-01-01

    Full Text Available Reverberation rooms are useful for measurement of the acoustic quantities of machines that operate in long cycles, however, current reverberation chamber design practices often lead to known issues with reproducibility and repeatability of measured data. The problem is that construction process of these laboratories is performed according to the relevant standards requirements which are mainly focused on the volume of the room or on the absorption coefficient value of the boundary surfaces. Nevertheless, the inner-laboratory reproducibility of acoustic data is very difficult to achieve even when these diffusivity quantifiers are satisfied. This paper presents a verification process of an acoustic laboratory which proportions, shape and construction material of boundary surfaces are not in compliance with standards in every detail.

  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. Tethered acoustic doppler current profiler platforms for measuring streamflow

    Science.gov (United States)

    Rehmel, Michael S.; Stewart, James A.; Morlock, Scott E.

    2003-01-01

    The U.S. Geological Survey tested and refined tethered-platform designs for measuring streamflow. Platform specifications were developed, radio-modem telemetry of acoustic Doppler current profiler (ADCP) data and potential platform-hull sources were investigated, and hulls were tested and evaluated.

  10. 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.

  11. A Comparative Study of Two Acoustic Measures of Hypernasality

    Science.gov (United States)

    Vogel, Adam P.; Ibrahim, Hasherah M.; Reilly, Sheena; Kilpatrick, Nicky

    2009-01-01

    Purpose: This study aimed to compare 2 quantitative acoustic measures of nasality in children with cleft lip and palate (CLP) and healthy controls using formalized perceptual assessment as a guide. Method: Fifty participants (23 children with CLP and 27 age- and gender-matched healthy controls) aged between 4 and 12 years produced a variety of…

  12. Measurement of acoustic attenuation in South Pole ice

    Science.gov (United States)

    IceCube Collaboration; 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.; Bazo Alba, J. L.; 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.; Böser, 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.; de Clercq, C.; Demirörs, L.; Depaepe, O.; Descamps, F.; Desiati, P.; de Vries-Uiterweerd, G.; Deyoung, T.; Díaz-Vélez, J. C.; Dreyer, J.; Dumm, J. P.; Duvoort, M. R.; Ehrlich, R.; Eisch, J.; Ellsworth, R. W.; Engdegård, 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.; Glüsenkamp, 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.; Hülß, J.-P.; Hulth, P. O.; Hultqvist, K.; Hussain, S.; Imlay, R. L.; Ishihara, A.; Jacobsen, J.; Japaridze, G. S.; Johansson, H.; Joseph, J. M.; Kampert, K.-H.; Kappes, A.; Karg, T.; Karle, A.; Kelley, J. L.; Kemming, N.; Kenny, P.; Kiryluk, J.; Kislat, F.; Klein, S. R.; Knops, S.; Köhne, J.-H.; Kohnen, G.; Kolanoski, H.; Köpke, L.; Koskinen, D. J.; Kowalski, M.; Kowarik, T.; Krasberg, M.; Krings, T.; Kroll, G.; Kuehn, K.; Kuwabara, T.; Labare, M.; Lafebre, S.; Laihem, K.; Landsman, H.; Lauer, R.; Lehmann, R.; Lennarz, D.; Lünemann, J.; Madsen, J.; Majumdar, P.; Maruyama, R.; Mase, K.; Matis, H. S.; Matusik, M.; Meagher, K.; Merck, M.; Mészáros, P.; Meures, T.; Middell, E.; Milke, N.; Montaruli, T.; Morse, R.; Movit, S. M.; Nahnhauer, R.; Nam, J. W.; Naumann, U.; Nießen, P.; Nygren, D. R.; Odrowski, S.; Olivas, A.; Olivo, M.; Ono, M.; Panknin, S.; Paul, L.; Pérez de Los Heros, C.; Petrovic, J.; Piegsa, A.; Pieloth, D.; Porrata, R.; Posselt, J.; Price, P. B.; Prikockis, M.; Przybylski, G. T.; Rawlins, K.; Redl, P.; Resconi, E.; Rhode, W.; Ribordy, M.; Rizzo, A.; Rodrigues, J. P.; Roth, P.; Rothmaier, F.; Rott, C.; Roucelle, C.; Ruhe, T.; Rutledge, D.; Ruzybayev, B.; Ryckbosch, D.; Sander, H.-G.; Sarkar, S.; Schatto, K.; Schlenstedt, S.; Schmidt, T.; Schneider, D.; Schukraft, A.; Schultes, A.; Schulz, O.; Schunck, M.; Seckel, D.; Semburg, B.; Seo, S. H.; Sestayo, Y.; Seunarine, S.; Silvestri, A.; Slipak, A.; Spiczak, G. M.; Spiering, C.; Stamatikos, M.; Stanev, T.; Stephens, G.; Stezelberger, T.; Stokstad, R. G.; Stoyanov, S.; Strahler, E. A.; Straszheim, T.; Sullivan, G. W.; Swillens, Q.; Taboada, I.; Tamburro, A.; Tarasova, O.; Tepe, A.; Ter-Antonyan, S.; Tilav, S.; Toale, P. A.; Tosi, D.; Turčan, D.; van Eijndhoven, N.; Vandenbroucke, J.; van Overloop, A.; van Santen, J.; Voigt, B.; Walck, C.; Waldenmaier, T.; Wallraff, M.; Walter, M.; Wendt, C.; Westerhoff, S.; Whitehorn, N.; Wiebe, K.; Wiebusch, C. H.; Wikström, G.; Williams, D. R.; Wischnewski, R.; Wissing, H.; Woschnagg, K.; Xu, C.; Xu, X. W.; Yanez, J. P.; Yodh, G.; Yoshida, S.; Zarzhitsky, P.; IceCube Collaboration

    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 analyzed and give consistent results. The method with the smallest systematic uncertainties yields an amplitude attenuation coefficient α = 3.20 ± 0.57 km-1 between 10 and 30 kHz, considerably larger than previous theoretical estimates. Expressed as an attenuation length, the analyses give a consistent result for λ ≡ 1/α of ˜300 m with 20% uncertainty. No significant depth or frequency dependence has been found.

  13. 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.

  14. 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...... in the transmission such as the earphone impedance. In order to determine the acoustic impedances of human ear canals, the standardized method for measurement of complex impedances used for the measurement of the audiometric earphone impedances is applied. It is based on the transfer function between two microphone...... 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...

  15. Real-time temperature field measurement based on acoustic tomography

    Science.gov (United States)

    Bao, Yong; Jia, Jiabin; Polydorides, Nick

    2017-07-01

    Acoustic tomography can be used to measure the temperature field from the time-of-flight (TOF). In order to capture real-time temperature field changes and accurately yield quantitative temperature images, two improvements to the conventional acoustic tomography system are studied: simultaneous acoustic transmission and TOF collection along multiple ray paths, and an offline iteration reconstruction algorithm. During system operation, all the acoustic transceivers send modulated and filtered wideband Kasami sequences simultaneously to facilitate fast and accurate TOF measurements using cross-correlation detection. For image reconstruction, the iteration process is separated and executed offline beforehand to shorten computation time for online temperature field reconstruction. The feasibility and effectiveness of the developed methods are validated in the simulation study. The simulation results demonstrate that the proposed method can reduce the processing time per frame from 160 ms to 20 ms, while the reconstruction error remains less than 5%. Hence, the proposed method has great potential in the measurement of rapid temperature change with good temporal and spatial resolution.

  16. 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.

  17. 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.

  18. 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.

  19. Measurement of acoustic attenuation in workrooms

    DEFF Research Database (Denmark)

    Rindel, Jens Holger

    1997-01-01

    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.......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...

  20. 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.

  1. 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.

  2. Estimating suspended solids concentrations from backscatter intensity measured by acoustic Doppler current profiler in San Francisco Bay, California

    Science.gov (United States)

    Gartner, J.W.

    2004-01-01

    The estimation of mass concentration of suspended solids is one of the properties needed to understand the characteristics of sediment transport in bays and estuaries. However, useful measurements or estimates of this property are often problematic when employing the usual methods of determination from collected water samples or optical sensors. Analysis of water samples tends to undersample the highly variable character of suspended solids, and optical sensors often become useless from biological fouling in highly productive regions. Acoustic sensors, such as acoustic Doppler current profilers that are now routinely used to measure water velocity, have been shown to hold promise as a means of quantitatively estimating suspended solids from acoustic backscatter intensity, a parameter used in velocity measurement. To further evaluate application of this technique using commercially available instruments, profiles of suspended solids concentrations are estimated from acoustic backscatter intensity recorded by 1200- and 2400-kHz broadband acoustic Doppler current profilers located at two sites in San Francisco Bay, California. ADCP backscatter intensity is calibrated using optical backscatterance data from an instrument located at a depth close to the ADCP transducers. In addition to losses from spherical spreading and water absorption, calculations of acoustic transmission losses account for attenuation from suspended sediment and correction for nonspherical spreading in the near field of the acoustic transducer. Acoustic estimates of suspended solids consisting of cohesive and noncohesive sediments are found to agree within about 8-10% (of the total range of concentration) to those values estimated by a second optical backscatterance sensor located at a depth further from the ADCP transducers. The success of this approach using commercially available Doppler profilers provides promise that this technique might be appropriate and useful under certain conditions in

  3. 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...

  4. 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.

  5. 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...

  6. 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.

  7. 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.

  8. Electromagnetic acoustic transducers noncontacting ultrasonic measurements using EMATS

    CERN Document Server

    Hirao, Masahiko

    2017-01-01

    This second edition provides comprehensive information on electromagnetic acoustic transducers (EMATs), from the theory and physical principles of EMATs to the construction of systems and their applications to scientific and industrial ultrasonic measurements on materials. The original version has been complemented with selected ideas on ultrasonic measurement that have emerged since the first edition was released. The book is divided into four parts: PART I offers a self-contained description of the basic elements of coupling mechanisms along with the practical designing of EMATs for various purposes. Several implementations to compensate for EMATs’ low transfer efficiency are provided, along with useful tips on how to make an EMAT. PART II describes the principle of electromagnetic acoustic resonance (EMAR), which makes the most of EMATs’ contactless nature and is the most successful amplification mechanism for precise measurements of velocity and attenuation. PART III applies EMAR to studying physical ...

  9. DEMON Acoustic Ship Signature Measurements in an Urban Harbor

    Directory of Open Access Journals (Sweden)

    Kil Woo Chung

    2011-01-01

    Full Text Available Detection, classification, and tracking of small vessels are important tasks for improving port security and the security of coastal and offshore operations. Hydroacoustic sensors can be applied for the detection of noise generated by vessels, and this noise can be used for vessel detection, classification, and tracking. This paper presents recent improvements aimed at the measurement and separation of ship DEMON (Detection of Envelope Modulation on Noise DEMON acoustic signatures in busy harbor conditions. Ship signature measurements were conducted in the Hudson River and NY Harbor. The DEMON spectra demonstrated much better temporal stability compared with the full ship spectra and were measured at distances up to 7 km. The combination of cross-correlation and methods allowed separation of the acoustic signatures of ships in busy urban environments.

  10. 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...

  11. 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...

  12. 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...

  13. Acoustic property measurements in a photoacoustic imager

    Science.gov (United States)

    Willemink, René G. H.; Manohar, Srirang; Slump, Cornelis H.; van der Heijden, Ferdi; van Leeuwen, Ton

    2007-07-01

    Photoacoustics is a hybrid imaging technique that combines the contrast available to optical imaging with the resolution that is possessed by ultrasound imaging. The technique is based on generating ultrasound from absorbing structures in tissue using pulsed light. In photoacoustic (PA) computerized tomography (CT) imaging, reconstruction of the optical absorption in a subject, is performed for example by filtered backprojection. The backprojection is performed along circular paths in image space instead of along straight lines as in X-ray CT imaging. To achieve this, the speed-of-sound through the subject is usually assumed constant. An unsuitable speed-of-sound can degrade resolution and contrast. We discuss here a method of actually measuring the speed-of- sound distribution using ultrasound transmission through the subject under photoacoustic investigation. This is achieved in a simple approach that does not require any additional ultrasound transmitter. The method uses a passive element (carbon fiber) that is placed in the imager in the path of the illumination which generates ultrasound by the photoacoustic effect and behaves as an ultrasound source. Measuring the time-of-flight of this ultrasound transient by the same detector used for conventional photoacoustics, allows a speed-of-sound image to be reconstructed. This concept is validated on phantoms.

  14. 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.

  15. Atypical prosody in Asperger syndrome: perceptual and acoustic measurements.

    Science.gov (United States)

    Filipe, Marisa G; Frota, Sónia; Castro, São Luís; Vicente, Selene G

    2014-08-01

    It is known that individuals with Asperger syndrome (AS) may show no problems with regard to what is said (e.g., lexical content) but tend to have difficulties in how utterances are produced, i.e., they may show prosodic impairments. In the present study, we focus on the use of prosodic features to express grammatical meaning. Specifically, we explored the sentence type difference between statements and questions that is conveyed by intonation, using perceptual and acoustic measurements. Children aged 8 and 9 years with AS (n = 12) were matched according to age and nonverbal intelligence with typically developing peers (n = 17). Although children with AS could produce categorically accurate prosodic patterns, their prosodic contours were perceived as odd by adult listeners, and acoustic measurements showed alterations in duration and pitch. Additionally, children with AS had greater variability in fundamental frequency contours compared to typically developing peers.

  16. Velocity and rotation measurements in acoustically levitated droplets

    Energy Technology Data Exchange (ETDEWEB)

    Saha, Abhishek [University of Central Florida, Orlando, FL 32816 (United States); Basu, Saptarshi [Indian Institute of Science, Bangalore 560012 (India); Kumar, Ranganathan, E-mail: ranganathan.kumar@ucf.edu [University of Central Florida, Orlando, FL 32816 (United States)

    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. -- Highlights: ► Demonstrates the importance of rotation in a levitated droplet that leads to controlled morphology. ► Provides detailed measurements of Particle Image Velocimetry inside levitated droplets. ► Shows variation of vortex strength with the droplet diameter and viscosity of the liquid.

  17. Determining Transmission Loss from Measured External and Internal Acoustic Environments

    Science.gov (United States)

    Scogin, Tyler; Smith, A. M.

    2012-01-01

    An estimate of the internal acoustic environment in each internal cavity of a launch vehicle is needed to ensure survivability of Space Launch System (SLS) avionics. Currently, this is achieved by using the noise reduction database of heritage flight vehicles such as the Space Shuttle and Saturn V for liftoff and ascent flight conditions. Marshall Space Flight Center (MSFC) is conducting a series of transmission loss tests to verify and augment this method. For this test setup, an aluminum orthogrid curved panel representing 1/8th of the circumference of a section of the SLS main structure was mounted in between a reverberation chamber and an anechoic chamber. Transmission loss was measured across the panel using microphones. Data measured during this test will be used to estimate the internal acoustic environments for several of the SLS launch vehicle internal spaces.

  18. Atypical Prosody in Asperger Syndrome: Perceptual and Acoustic Measurements

    OpenAIRE

    Marisa G. Filipe; Frota, Sónia; Castro, São Luís; Vicente, Selene G.

    2014-01-01

    It is known that individuals with Asperger syndrome (AS) may show no problems with regard to what is said (e.g., lexical content) but tend to have difficulties in how utterances are produced, i.e., they may show prosodic impairments. In the present study, we focus on the use of prosodic features to express grammatical meaning. Specifically, we explored the sentence type difference between statements and questions that is conveyed by intonation, using perceptual and acoustic measurements. Chil...

  19. 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.

  20. 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.

  1. Diamond color measurement instrument based on image processing

    Science.gov (United States)

    Takahashi, H.; Mandal, S.; Toosi, M.; Zeng, J.; Wang, W.

    2016-09-01

    Gemological Institute of America (GIA) has developed a diamond color measurement instrument that can provide accurate and reproducible color measurement results. The instrument uses uniform illumination by a daylight-approximating light source; observations from a high-resolution color-camera with nearly zero-distortion bi-telecentric lens, and image processing to calculate color parameters of diamonds. Experiments show the instrument can provide reproducible color measurement results and also identify subtle color differences in diamonds with high sensitivity. The experimental setup of the prototype instrument and the image processing method for calculating diamond color parameters are presented in this report.

  2. A review of instruments developed to measure food neophobia

    DEFF Research Database (Denmark)

    Damsbo-Svendsen, Marie; Frøst, Michael Bom; Olsen, Annemarie

    2017-01-01

    Food choices are influenced by an individual's attitude towards foods. Food neophobia may be associated with less variety of diets, inadequate nutrient intake and high product failure rate for new food products entering the market. To quantify the extent of these challenges, instruments to measure...... the food neophobia in different target groups are needed. Several such instruments with significantly different measurement outcomes and procedures have been developed. This review provides an overview and discusses strengths and weaknesses of these instruments...

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

    DEFF Research Database (Denmark)

    Overholt, Daniel; Freed, Adrian

    the musician’s movements. For example, gestural tilting of the instrument is tracked via an embedded Inertial Measurement Unit (IMU), which can be assigned to alter parameters such as the wet/dry mix of a simple octave-doubler or other more advanced audio effect, further augmenting the expressivity...

  4. 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.

  5. 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.

  6. Instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Decreton, M

    2002-04-01

    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.

  7. 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...

  8. 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.

  9. 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...

  10. Determining low-frequency source location from acoustic phase measurements

    Science.gov (United States)

    Poole, Travis L.; Frisk, George V.

    2002-11-01

    For low-frequency cw sound sources in shallow water, the time rate-of-change of the measured acoustic phase is well approximated by the time rate-of-change of the source-receiver separation distance. An algorithm for determining a locus of possible source locations based on this idea has been developed. The locus has the general form of a hyperbola, which can be used to provide a bearing estimation at long ranges, and an estimate of source location at short ranges. The algorithm uses only acoustic phase data and receiver geometry as input, and can be used even when the source frequency is slightly unstable and/or imprecisely known. The algorithm has been applied to data from low-frequency experiments (20-300 Hz), both for stable and unstable source frequencies, and shown to perform well. [Work supported by ONR and WHOI Academic Programs Office.

  11. Microcomputer based instrument for measuring a novel pulmonary function test

    Science.gov (United States)

    Craine, Brian L.; Craine, Eric R.

    1996-08-01

    The design of a prototype instrument for measuring the end-tidal concentration of carbon monoxide during human respiration is presented. The instrument automatically samples the final sixty cubic centimeters of exhaled breath, from successive breathing cycles, by coordinating a pump and the breathing cycle with a set of vacuum and pressure sensors. The concentration of carbon monoxide is measured using a nondispersive infrared spectrophotometer. The amount of carbon monoxide present is measured relative to the source air concentration eliminating the need for calibrating the instrument. The testing protocol and measurements can be controlled by a microcomputer connected to the instrument through a standard RS-232 serial interface. When at equilibrium, the end-tidal concentration of CO can be measured in a simple and reproducible fashion. This simplified technology allows for the construction of a small, portable, easy to use instrument that will allow the application of this new pulmonary function test at the point of contact with patients.

  12. 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...

  13. 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.

  14. Combined surface acoustic wave and surface plasmon resonance measurement of collagen and fibrinogen layer physical properties

    Directory of Open Access Journals (Sweden)

    J.-M. Friedt

    2016-12-01

    Full Text Available We use an instrument combining optical (surface plasmon resonance and acoustic (Love mode surface 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 and surfactant adsorption, 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 μg/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 μg/ml range.

  15. Calibration of ipsilateral stimulus transducer for acoustic reflex measurements.

    Science.gov (United States)

    Olsen, S; Osterhammel, P A; Rasmussen, A N; Nielsen, L H

    1995-01-01

    Pure-tone Reference Equivalent Threshold Sound Pressure Level (RETSPL) of the ipsilateral stimulus receiver for acoustic reflex measurements on Madsen Electronics type Zodiac 901 impedance audiometer is provided. The results, obtained from 20 normal-hearing subjects, are achieved by comparing hearing threshold levels measured using a TDH 39 telephone (calibrated to ISO 389) with thresholds recorded using the ipsilateral stimulus insert phone. The calibration is referenced to an IEC-711 ear simulator and comprises the following frequencies: 125, 250, 500, 750, 1000, 1500, 2000, 3000, 4000, 6000, 8000 Hz.

  16. Comparative performance of color-measuring instruments; second report.

    Science.gov (United States)

    Billmeyer, F W; Campbell, E D; Marcus, R T

    1974-06-01

    The comparative performance of twelve different late-model color-measuring instruments was studied for precision (short-term repeatability) and conformance of color measurement and color-difference measurement.The instruments tested included four true and two abridged spectrophotometers and six colorimeters, all being integrating-sphere instruments except three 45 degrees /0 degrees colorimeters. All the colorimeters were individually calibrated for close conformance to CIE coordinates. Forty-four samples taken from the group studied in the previous paper were measured three times on each instrument, by three different well-trained operators. Again, a GE spectrophotometer was considered the reference instrument for conformance studies. Overall, the GE spectrophotometer, the Hunterlab D25D colorimeter, and the Kollmorgen KCS-18 and KCS-40 abridged spectrophotometers demonstrated the best performance. Statistical treatment of the data has been improved vastly since the earlier paper, and some recalculated results are included.

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

    Science.gov (United States)

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

    2016-11-01

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

  18. Field of Temperature Measurement by Virtual Instrumentation

    Directory of Open Access Journals (Sweden)

    Libor HARGAŠ

    2009-01-01

    Full Text Available This paper introduces about temperature determination for given dot of picture through image analysis. Heat transfer is the transition of thermal energy from a heated item to a cooler item. Main method of measurement of temperature in image is Pattern Matching, color scale detection and model detection. We can measure temperature dependency at time for selected point of thermo vision images. This measurement gives idea about the heat transfer at time dependences.

  19. A review of instruments developed to measure food neophobia.

    Science.gov (United States)

    Damsbo-Svendsen, Marie; Frøst, Michael Bom; Olsen, Annemarie

    2017-06-01

    Food choices are influenced by an individual's attitude towards foods. Food neophobia may be associated with less variety of diets, inadequate nutrient intake and high product failure rate for new food products entering the market. To quantify the extent of these challenges, instruments to measure the food neophobia in different target groups are needed. Several such instruments with significantly different measurement outcomes and procedures have been developed. This review provides an overview and discusses strengths and weaknesses of these instruments. We evaluate strengths and weaknesses of previously developed instruments to measure neophobia and willingness to try unfamiliar foods. Literature was searched through the databases Web of Science and Google Scholar. We identified 255 studies concerning neophobia and willingness to try unfamiliar foods. Of these, 13 studies encompassing 13 instruments to measure neophobia and willingness to try unfamiliar foods were included in the review. Results are summarized and evaluated with a narrative approach. In the 13 instruments to assess neophobia and willingness to try unfamiliar foods, 113 to 16.644 subjects aged 2-65 years were involved, scales with 3-7 response categories were used and behavioral validation tests were included in 6 studies. Several instruments to measure neophobia and willingness to try unfamiliar foods exist. We recommend selecting one or more among the 13 instruments reviewed in this paper to assess relevant aspects of neophobia. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  20. LEDA beam diagnostics instrumentation: Beam current measurement

    Science.gov (United States)

    Barr, D.; Day, L.; Gilpatrick, J. D.; Kasemir, K.-U.; Martinez, D.; Power, J. F.; Shurter, R.; Stettler, M.

    2000-11-01

    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® 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.

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. Measuring sound absorption: considerations on the measurement of the active acoustic power

    NARCIS (Netherlands)

    Kuipers, E.R.; Wijnant, Y.H.; Boer, de A.

    2014-01-01

    Using a local plane wave assumption, one can determine the normal incidence sound absorption coefficient of a surface by measuring the acoustic pressure and the particle velocity normal to that surface. As the measurement surface lies in front of the material surface, the measured active and inciden

  7. Requirements for a quality measurement instrument for semantic standards

    NARCIS (Netherlands)

    Folmer, E.J.A.; Krukkert, D.; Oude Luttighuis, P.; Hillegersberg van, J. van

    2010-01-01

    This study describes requirements for an instrument to measure the quality of semantic standards. A situational requirements engineering method was used, resulting in a goal-tree in which requirements are structured. This structure shows requirements related to the input of the instrument; stating

  8. 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.

  9. 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 ...

  10. 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.

  11. 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.

  12. 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...

  13. 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 important...

  14. 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

  15. 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...

  16. 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.

  17. In-Situ Measurement of Aerosol Light Absorption Using a Photo Acoustic Spectrometer

    Science.gov (United States)

    Schmid, O.; Andreae, M. O.; Helas, G.; Guyon, P.; Sciare, J.; Arnott, W. P.

    2002-12-01

    A recently developed photo acoustic spectrometer (PAS) (Arnott et al., 1999) has been used for in-situ light absorption measurements on atmospheric aerosol. Measurement campaigns in the Mediterranean and Amazon regions demonstrated the viability of the PAS under field conditions and provided data on the absorption coefficient of atmospheric aerosol generated by anthropogenic pollution and biomass burning, respectively. By operating the PAS in series with a nephelometer the scattering albedo of (dry) atmospheric aerosol was determined. Here we discuss the principle of the PAS, describe the calibration technique, and present some field data. Arnott, W. P., H. Moosmuller, C. F. Rogers, T. Jin, and R. Bruch, Photoacoustic spectrometer for measuring light absorption by aerosol: instrument description, Atmos. Environ, 33, 2845-2852, 1999.

  18. Measurement of incident sound power using near field acoustic holography

    DEFF Research Database (Denmark)

    Jacobsen, Finn; Tiana Roig, Elisabet

    2009-01-01

    ; and it has always been regarded as impossible to measure the sound power that is incident on a wall directly. This paper examines a new method of determining this quantity from sound pressure measurements at positions on the wall using ‘statistically optimised near field acoustic holography’ (SONAH......The conventional method of measuring the insertion loss of a partition relies on an assumption of the sound field in the source room being diffuse and the classical relation between the spatial average of the mean square pressure in the source room and the incident sound power per unit area......). The purpose is to examine whether one should use a correction similar to the well-known ‘Waterhouse correction’ when the incident sound power is deduced from the sound pressure in the source room....

  19. 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...

  20. 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.

  1. 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.

  2. 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.

  3. Measuring Perceived Anonymity: The Development of a Context Independent Instrument

    Directory of Open Access Journals (Sweden)

    Dwight M. Hite

    2014-09-01

    Full Text Available In order to assess relationships between perceptions of anonymity and behaviors, a context independent instrument is required for measuring the perceptions of anonymity held by individuals.  To date, no such measurement instrument exists that has been shown to be reliable and valid.  The authors employ a rigorous design methodology to develop, test, and substantiate a reliable and valid instrument for measuring perceptions of anonymity across different contexts. The PA measure presented is a five item Likert scale designed to measure perceptions of anonymity across multiple contexts. Results from two separate EFA pilot tests (n=61 and n=60, a test-retest, and a CFA final test (n=292 indicate that the PA measure has good internal consistency reliability (a=.82, test-retest reliability, factorial validity, and a single factor structure. DOI: 10.2458/azu_jmmss.v5i1.18305

  4. Validation of streamflow measurements made with M9 and RiverRay acoustic Doppler current profilers

    Science.gov (United States)

    Boldt, Justin A.; Oberg, Kevin A.

    2015-01-01

    The U.S. Geological Survey (USGS) Office of Surface Water (OSW) previously validated the use of Teledyne RD Instruments (TRDI) Rio Grande (in 2007), StreamPro (in 2006), and Broadband (in 1996) acoustic Doppler current profilers (ADCPs) for streamflow (discharge) measurements made by the USGS. Two new ADCPs, the SonTek M9 and the TRDI RiverRay, were first used in the USGS Water Mission Area programs in 2009. Since 2009, the OSW and USGS Water Science Centers (WSCs) have been conducting field measurements as part of their stream-gaging program using these ADCPs. The purpose of this paper is to document the results of USGS OSW analyses for validation of M9 and RiverRay ADCP streamflow measurements. The OSW required each participating WSC to make comparison measurements over the range of operating conditions in which the instruments were used until sufficient measurements were available. The performance of these ADCPs was evaluated for validation and to identify any present and potential problems. Statistical analyses of streamflow measurements indicate that measurements made with the SonTek M9 ADCP using firmware 2.00–3.00 or the TRDI RiverRay ADCP using firmware 44.12–44.15 are unbiased, and therefore, can continue to be used to make streamflow measurements in the USGS stream-gaging program. However, for the M9 ADCP, there are some important issues to be considered in making future measurements. Possible future work may include additional validation of streamflow measurements made with these instruments from other locations in the United States and measurement validation using updated firmware and software.

  5. 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.

  6. Calculations of flexibility module in measurements instruments

    Science.gov (United States)

    Wróbel, A.; Płaczek, M.; Baier, A.

    2017-08-01

    Piezoelectricity has found a lot of applications since it were discovered in 1880 by Pierre and Jacques Curie. There are many applications of the direct piezoelectric effect - the production of an electric potential when stress is applied to the piezoelectric material, as well as the reverse piezoelectric effect - the production of strain when an electric field is applied. This work presents a mathematical model of a new model of vibration sensor. The principle of operation of currently used sensors is based on the idea: changes in thickness of the piezoelectric plates cause the vibration of the mechanical element, so-called “fork”. If the “forks” are not buried by the material deformation of the full tiles broadcasting is transmitted to receiver piezoelectric plate. As a result of vibration of receiver plates the cladding is formed on the potential difference proportional to the force. The value of this voltage is processed by an electronic circuit. In the case of backfilling “forks” the electric signal is lower. At the same time is not generated the potential for cladding tiles. Such construction have a lot of drawbacks, for example: need to use several piezoelectric plates, with the increase in number of components is increased failure of sensors, sensors have now produced two forks resonance, using these sensors in moist materials is often the case that the material remains between the forks and at the same time causes a measurement error. Mentioned disadvantages do not appear in the new proposed sensor design. The Galerkin method of the analysis of considered systems will be presented started from development of the mathematical model, to determine the graphs of flexibility and confirm two methods: exact and approximate. Analyzed beam is a part of the vibration level sensor and the results will be used to identify the electrical parameters of the generator. Designing of technical systems containing piezoelectric transducers is a complex process

  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. 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.

  9. Supersonic Relative Velocity Effect on the Baryonic Acoustic Oscillation Measurements

    CERN Document Server

    Yoo, Jaiyul; Seljak, Uros

    2011-01-01

    We investigate the effect of supersonic relative velocities between baryons and dark matter, recently shown to arise generically at high redshift, on baryonic acoustic oscillation (BAO) measurements at low redshift. The amplitude of the relative velocity effect at low redshift is model-dependent, but can be parameterized by using an unknown bias. We find that if unaccounted, the relative velocity effect can shift the BAO peak position and bias estimates of the dark energy equation-of-state due to its non-smooth, out-of-phase oscillation structure around the BAO scale. Fortunately, the relative velocity effect can be easily modeled in constraining cosmological parameters without substantially inflating the error budget. We also demonstrate that the presence of the relative velocity effect gives rise to a unique signature in the galaxy bispectrum, which can be utilized to isolate this effect. Future dark energy surveys can accurately measure the relative velocity effect and subtract it from the power spectrum a...

  10. 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.

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

    Science.gov (United States)

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

    2004-02-01

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

  12. Prediction and Measurement of the Vibration and Acoustic Radiation of Panels Subjected to Acoustic Loading

    Science.gov (United States)

    Turner, Travis L.; Rizzi, Stephen A.

    1995-01-01

    Interior noise and sonic fatigue are important issues in the development and design of advanced subsonic and supersonic aircraft. Conventional aircraft typically employ passive treatments, such as constrained layer damping and acoustic absorption materials, to reduce the structural response and resulting acoustic levels in the aircraft interior. These techniques require significant addition of mass and only attenuate relatively high frequency noise transmitted through the fuselage. Although structural acoustic coupling is in general very important in the study of aircraft fuselage interior noise, analysis of noise transmission through a panel supported in an infinite rigid baffle (separating two semi-infinite acoustic domains) can be useful in evaluating the effects of active/adaptive materials, complex loading, etc. Recent work has been aimed at developing adaptive and/or active methods of controlling the structural acoustic response of panels to reduce the transmitted noise1. A finite element formulation was recently developed to study the dynamic response of shape memory alloy (SMA) hybrid composite panels (conventional composite panel with embedded SMA fibers) subject to combined acoustic and thermal loads2. Further analysis has been performed to predict the far-field acoustic radiation using the finite element dynamic panel response prediction3. The purpose of the present work is to validate the panel vibration and acoustic radiation prediction methods with baseline experimental results obtained from an isotropic panel, without the effect of SMA.

  13. 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...... and reproductive function after SCI. There were no measures identified to assess female reproductive function. CONCLUSIONS: For clinical trials aiming to improve sexual function after SCI, the FSFI or the IIEF is currently preferred. Although VPA is an appropriate means to assess female sexual responses......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...

  14. Holdup Measures on an SRNL Mossbauer Spectroscopy Instrument

    Energy Technology Data Exchange (ETDEWEB)

    Dewberry, R.; Brown, T.; Salaymeh, S.

    2010-05-05

    Gamma-ray holdup measurements of a Mossbauer spectroscopy instrument are described and modeled. In the qualitative acquisitions obtained in a low background area of Savannah River National Laboratory, only Am-241 and Np-237 activity were observed. The Am-241 was known to be the instrumental activation source, while the Np-237 is clearly observed as a source of contamination internal to the instrument. The two sources of activity are modeled separately in two acquisition configurations using two separate modeling tools. The results agree well, demonstrating a content of (1980 {+-} 150) {mu}Ci Am-241 and (110 {+-} 50) {mu}Ci of Np-237.

  15. 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...

  16. Standardization Procedure for Two Instruments for Color Measurement

    Science.gov (United States)

    1981-09-01

    contract and reported separately. In one of these contracts Billmeyer and Alessi addressed the general reliability of commercial color instruments...collection and the standardization test procedure. 1. F. W. Billmeyer , Jr. and P. J. Alessi (1979, "Assessment of Color- Measuring Instruments for Objective...U.S. Army Natick Research and De- velopment Command, Natick, HA 01760 (ADA094163) Billmeyer , F. W., Jr. and Alessi, P.J. (1979), "Assessment of

  17. 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...

  18. Application of acoustic doppler velocimeters for streamflow measurements

    Science.gov (United States)

    Rehmel, M.

    2007-01-01

    The U.S. Geological Survey (USGS) principally has used Price AA and Price pygmy mechanical current meters for measurement of discharge. New technologies have resulted in the introduction of alternatives to the Price meters. One alternative, the FlowTracker acoustic Doppler velocimeter, was designed by SonTek/YSI to make streamflow measurements in wadeable conditions. The device measures a point velocity and can be used with standard midsection method algorithms to compute streamflow. The USGS collected 55 quality-assurance measurements with the FlowTracker at 43 different USGS streamflow-gaging stations across the United States, with mean depths from 0.05to0.67m, mean velocities from 13 to 60 cm/s, and discharges from 0.02 to 12.4m3/s. These measurements were compared with Price mechanical current meter measurements. Analysis of the comparisons shows that the FlowTracker discharges were not statistically different from the Price meter discharges at a 95% confidence level. ?? 2007 ASCE.

  19. 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 the m...... the measurement is processed, he or she just sets some parameters in a software and clicks a virtual button....

  20. Architectural acoustics

    National Research Council Canada - National Science Library

    Long, Marshall

    2014-01-01

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

  1. 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.

  2. 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.

  3. Instruments for measuring mental health recovery: a systematic review.

    Science.gov (United States)

    Sklar, Marisa; Groessl, Erik J; O'Connell, Maria; Davidson, Larry; Aarons, Gregory A

    2013-12-01

    Persons in recovery, providers, and policymakers alike are advocating for recovery-oriented mental health care, with the promotion of recovery becoming a prominent feature of mental health policy in the United States and internationally. One step toward creating a recovery-oriented system of care is to use recovery-oriented outcome measures. Numerous instruments have been developed to assess progress towards mental health recovery. This review identifies instruments of mental health recovery and evaluates the appropriateness of their use including their psychometric properties, ease of administration, and service-user involvement in their development. A literature search using the Medline and Psych-INFO databases was conducted, identifying 21 instruments for potential inclusion in this review, of which thirteen met inclusion criteria. Results suggest only three instruments (25%) have had their psychometric properties assessed in three or more unique samples of participants. Ease of administration varied between instruments, and for the majority of instruments, development included service user involvement. This review updates and expands previous reviews of instruments to assess mental health recovery. As mental health care continues to transform to a recovery-oriented model of service delivery, this review may facilitate selection of appropriate assessments of mental health recovery for systems to use in evaluating and improving the care they provide.

  4. 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.

  5. 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...

  6. Comparison of nanoparticle measurement instruments for occupational health applications

    Energy Technology Data Exchange (ETDEWEB)

    Leskinen, J., E-mail: jani.leskinen@uef.fi [University of Eastern Finland, Fine Particle and Aerosol Technology Laboratory, Department of Environmental Science (Finland); Joutsensaari, J. [University of Eastern Finland, Department of Applied Physics (Finland); Lyyraenen, J. [VTT Technical Research Centre of Finland, Fine Particles (Finland); Koivisto, J. [Nanosafety Research Center, Finnish Institute of Occupational Health (Finland); Ruusunen, J. [University of Eastern Finland, Fine Particle and Aerosol Technology Laboratory, Department of Environmental Science (Finland); Jaervelae, M.; Tuomi, T. [Finnish Institute of Occupational Health (Finland); Haemeri, K. [University of Helsinki, Division of Atmospheric Sciences, Department of Physics (Finland); Auvinen, A. [VTT Technical Research Centre of Finland, Fine Particles (Finland); Jokiniemi, J. [University of Eastern Finland, Fine Particle and Aerosol Technology Laboratory, Department of Environmental Science (Finland)

    2012-02-15

    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 TiO{sub 2} agglomerates and aerosolised TiO{sub 2} 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 TiO{sub 2} 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 TiO{sub 2} 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.

  7. Glacier studies on the basis of acoustic measurements

    Directory of Open Access Journals (Sweden)

    V. P. Epifanov

    2013-01-01

    Full Text Available The possibility of glacier ice flow studies using the method of acoustic emission (AE in frequency range from 15 Hz to 20 kHz has been considered. A portable acoustic line system has been developed and a number of methodological issues (mounting of acoustic sensors into glacial ice, their location, reliability of acoustic coupling, etc. have been solved. Acoustic studies of glacial ice have been performed; rock fall effect, ice cracking and ice movement on bedrock have been simulated. Correspondences of AE parameters to specific sources have been identified. The results of acoustic studies on Aldegondabreen (Spitsbergen, Central Tuyuksu and Molodezhny glaciers (northern Tien Shan have been summarized. The dependence of the adhesive strength of ice with smooth substrate (serpentenite on the shear rate has been considered; the effect of tor-shaped obstacle on shear force has been estimated. It is shown that the acoustic effects at cohesive ice failure on obstacles are similar to the observed natural acoustic vibrations generated in glaciers from distant sources. The results might be applied in development of the mobile ice lab and system for remote acoustic monitoring the processes in the bottom layers of glaciers.

  8. 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.

  9. Instrument for thermal radiation flux measurement in high temperature gas flow (Cuernavaca instrument)

    Energy Technology Data Exchange (ETDEWEB)

    Afgan, N.H. [Universidade Tecnica, Lisbon (Portugal); Leontiev, A.I. [Moscow State Technical University (Russian Federation)

    1995-05-01

    A new instrument for hemispherical radiation heat flux measurement is proposed. It is based on the theory of blow of the boundary layer, taking into account that at the critical mass flow rate through the porous surface the thermal boundary layer is blown off and only radiation flux from high temperature gases reaches the porous surface. With the measurement of blow of gas flow and the temperature of the porous material, the respective heat flux is obtained. (author)

  10. 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.

  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. An Autonomous Ozone Instrument for Atmospheric Measurements from Ocean Buoys

    Science.gov (United States)

    Hintsa, E. J.; Rawlins, W. T.; Sholkovitz, E. R.; Hosom, D. S.; Allsup, G. P.; Purcell, M. J.; Scott, D. R.; Mulhall, P.

    2002-05-01

    Tropospheric ozone is an oxidant, a greenhouse gas, and a pollutant. Because of its adverse health effects, there are numerous monitoring stations on land but none over the oceans. We have built an ozone instrument for deployment anywhere at sea from ocean buoys, to study ozone chemistry over the oceans, intercontinental transport of pollution, diurnal and seasonal cycles of ozone, and to make baseline and long-term time series measurements of ozone in remote locations. The instrument uses direct (Beer's Law) absorption of UV radiation in a dual-path cell, with ambient and ozone-free air alternately switched between the two paths, to measure ozone. Ozone can be measured at a rate of 1 Hz, with a precision of about 1 ppb at sea level. The air inlet and outlet have valves which close automatically under high wind conditions or rain to protect the ozone sensor. The instrument has been packaged for deployment at sea, and tested on a 3-meter discus buoy with other instruments in coastal waters in fall 2001. It can operate autonomously or be controlled via line-of-sight modem or a satellite link. We will present the details of the instrument, and laboratory and buoy test data from its first deployment, including a comparison with a nearby ozone monitoring station on land. We will also present an evaluation of the instrument's performance and describe plans for improvements. In summer 2002, the ozone measurement system will be operated at the Martha's Vineyard Coastal Observatory; in the future we anticipate deploying on the Bermuda Testbed Mooring, followed by use on the open ocean to measure long-range transport of ozone.

  13. 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.

  14. 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

  15. 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.

  16. 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

  17. 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

  18. 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 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 reproductive function after SCI. There were no measures identified to assess female reproductive function. CONCLUSIONS: For clinical trials aiming to improve sexual function after SCI, the FSFI or the IIEF is currently preferred. Although VPA is an appropriate means to assess female sexual responses...

  19. Acoustic Measurements of an Uninstalled Spacecraft Cabin Ventilation Fan Prototype

    Science.gov (United States)

    Koch, L. Danielle; Brown, Clifford A.; Shook, Tony D.; Winkel, James; Kolacz, John S.; Podboy, Devin M.; Loew, Raymond A.; Mirecki, Julius H.

    2012-01-01

    Sound pressure measurements were recorded for a prototype of a spacecraft cabin ventilation fan in a test in the NASA Glenn Acoustical Testing Laboratory. The axial fan is approximately 0.089 m (3.50 in.) in diameter and 0.223 m (9.00 in.) long and has nine rotor blades and eleven stator vanes. At design point of 12,000 rpm, the fan was predicted to produce a flow rate of 0.709 cu m/s (150 cfm) and a total pressure rise of 925 Pa (3.72 in. of water) at 12,000 rpm. While the fan was designed to be part of a ducted atmospheric revitalization system, no attempt was made to throttle the flow or simulate the installed configuration during this test. The fan was operated at six speeds from 6,000 to 13,500 rpm. A 13-microphone traversing array was used to collect sound pressure measurements along two horizontal planes parallel to the flow direction, two vertical planes upstream of the fan inlet and two vertical planes downstream of the fan exhaust. Measurements indicate that sound at blade passing frequency harmonics contribute significantly to the overall audible noise produced by the fan at free delivery conditions.

  20. Experimental and Theoretical Measurements of Concentration Distributions in Acoustic Focusing Devices

    Energy Technology Data Exchange (ETDEWEB)

    Rose, K A; Fisher, K; Jung, B; Ness, K; Mariella Jr., R P

    2008-06-16

    We describe a modeling approach to capture the particle motion within an acoustic focusing microfluidic device. Our approach combines finite element models for the acoustic forces with analytical models for the fluid motion and uses these force fields to calculate the particle motion in a Brownian dynamics simulation. We compare results for the model with experimental measurements of the focusing efficiency within a microfabricated device. The results show good qualitative agreement over a range of acoustic driving voltages and particle sizes.

  1. The current status of measurement standards for acoustics and vibration at Inmetro

    OpenAIRE

    Ripper, Gustavo Palmeira; Hoffmann, Walter Erico

    2002-01-01

    ABSTRACT: The Division of Acoustics and Vibration (DIAVI) of INMETRO establishes, validates and maintains the Brazilian national measurement standards used for the realization of the units of physical quantities related to the field of acoustics and vibration. The basic vibration quantity realized by DIAVI is translational acceleration, from which the other motion quantities, i.e., velocity and displacement can be derived. Acoustical physical quantities include sound pressure and sound power...

  2. 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

  3. Measurement Properties of Instruments for Measuring of Lymphedema: Systematic Review

    NARCIS (Netherlands)

    Hidding, J.T.; Viehoff, P.B.; Beurskens, C.H.G.; Laarhoven, H.W. van; Sanden, M.W. van der; Wees, P.J. van der

    2016-01-01

    BACKGROUND: Lymphedema is a common complication of cancer treatment, resulting in swelling and subjective symptoms. Reliable and valid measurement of this side effect of medical treatment is important. PURPOSE: The purpose of this study was to provide best evidence regarding which measurement

  4. An instrument for measuring scintillators efficiently based on silicon photomultipliers.

    Science.gov (United States)

    Yang, M J; Zhang, Z M; Wang, Y J; Li, D W; Zhou, W; Tang, H H; Liu, Y T; Chai, P; Shuai, L; Huang, X C; Liu, S Q; Zhu, M L; Jiang, X P; Zhang, Y W; Li, T; Ma, B; Sun, S F; Sun, L Y; Wang, Q; Lu, Z R; Zhang, T; Wei, L

    2016-11-01

    An instrument used for measuring multiple scintillators' light output and energy resolution was developed. The instrument consisted of a light sensor array which was composed of 64 discrete SiPMs (Silicon Photomultipliers), a corresponding individual channel readout electronics system, and a data processing algorithm. A Teflon grid and a large interval between adjacent SiPMs were employed to eliminate the optical cross talk among scintillators. The scintillators' light output was obtained by comparing with a reference sample with known light output. Given the SiPM temperature dependency and the difference among each SiPM, a temperature offset correction algorithm and a non-uniformity correction algorithm were added to the instrument. A positioning algorithm, based on nine points, was designed to evaluate the performance of a scintillator array. Tests were performed to evaluate the instrument's performance. The uniformity of 64 channels for light output measurement was better than 98%, the stability was better than 98% when temperature varied from 15 °C to 40 °C, and the nonlinearity under 511 keV was better than 2%. This instrument was capable of selecting scintillators and evaluating the packaging technology of scintillator arrays with high efficiency and accuracy.

  5. An instrument for measuring scintillators efficiently based on silicon photomultipliers

    Science.gov (United States)

    Yang, M. J.; Zhang, Z. M.; Wang, Y. J.; Li, D. W.; Zhou, W.; Tang, H. H.; Liu, Y. T.; Chai, P.; Shuai, L.; Huang, X. C.; Liu, S. Q.; Zhu, M. L.; Jiang, X. P.; Zhang, Y. W.; Li, T.; Ma, B.; Sun, S. F.; Sun, L. Y.; Wang, Q.; Lu, Z. R.; Zhang, T.; Wei, L.

    2016-11-01

    An instrument used for measuring multiple scintillators' light output and energy resolution was developed. The instrument consisted of a light sensor array which was composed of 64 discrete SiPMs (Silicon Photomultipliers), a corresponding individual channel readout electronics system, and a data processing algorithm. A Teflon grid and a large interval between adjacent SiPMs were employed to eliminate the optical cross talk among scintillators. The scintillators' light output was obtained by comparing with a reference sample with known light output. Given the SiPM temperature dependency and the difference among each SiPM, a temperature offset correction algorithm and a non-uniformity correction algorithm were added to the instrument. A positioning algorithm, based on nine points, was designed to evaluate the performance of a scintillator array. Tests were performed to evaluate the instrument's performance. The uniformity of 64 channels for light output measurement was better than 98%, the stability was better than 98% when temperature varied from 15 °C to 40 °C, and the nonlinearity under 511 keV was better than 2%. This instrument was capable of selecting scintillators and evaluating the packaging technology of scintillator arrays with high efficiency and accuracy.

  6. 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

  7. 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...

  8. 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

  9. An intelligent instrument for measuring exhaust temperature of marine engine

    Institute of Scientific and Technical Information of China (English)

    MA Nan-qi; SU Hua; LIU Jun

    2006-01-01

    Exhaust temperature of the marine engine is commonly measured through thermocouple.Measure deviation will occur after using the thermocouple for some time due to nonlinearity of thermocouple itself, high temperature and chemical corrosion of measure point. Frequent replacement of thermocouple will increase the operating cost. This paper designs a new intelligent instrument for solving the above-mentioned problems of the marine engine temperature measurement, which combines the conventional thermocouple temperature measurement technology and SCM(single chip microcomputer).The reading of the thermocouple is simple and precise and the calibration can be made automatically and manually..

  10. Acoustic measurements of a liquefied cohesive sediment bed under waves

    Science.gov (United States)

    Mosquera, R.; Groposo, V.; Pedocchi, F.

    2014-04-01

    In this article the response of a cohesive sediment deposit under the action of water waves is studied with the help of laboratory experiments and an analytical model. Under the same regular wave condition three different bed responses were observed depending on the degree of consolidation of the deposit: no bed motion, bed motion of the upper layer after the action of the first waves, and massive bed motion after several waves. The kinematic of the upper 3 cm of the deposit were measured with an ultrasound acoustic profiler, while the pore-water pressure inside the bed was simultaneously measured using several pore pressure sensors. A poro-elastic model was developed to interpret the experimental observations. The model showed that the amplitude of the shear stress increased down into the bed. Then it is possible that the lower layers of the deposit experience plastic deformations, while the upper layers present just elastic deformations. Since plastic deformations in the lower layers are necessary for pore pressure build-up, the analytical model was used to interpret the experimental results and to state that liquefaction of a self consolidated cohesive sediment bed would only occur if the bed yield stress falls within the range defined by the amplitude of the shear stress inside the bed.

  11. 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.

  12. Antenna Characterization for the Wideband Instrument for Snow Measurements (WISM)

    Science.gov (United States)

    Lambert, Kevin M.; Miranda, Felix A.; Romanofsky, Robert R.; Durham, Timothy E.; Vanhille, Kenneth J.

    2015-01-01

    Experimental characterization of the antenna for the Wideband Instrument for Snow Measurement (WISM) under development for the NASA Earth Science Technology Office (ESTO) Instrument Incubator Program (IIP), is discussed. A current sheet antenna, consisting of a small, 6x6 element, dual-linear polarized array with integrated beamformer, feeds an offset parabolic reflector, enabling WISM operation over an 8 to 40 GHz frequency band. An overview of the test program implemented for both the feed and the reflector antenna is given along with select results for specific frequencies utilized by the radar and radiometric sensors of the WISM.

  13. Antenna Characterization for the Wideband Instrument for Snow Measurements

    Science.gov (United States)

    Lambert, Kevin M.; Miranda, Felix A.; Romanofsky, Robert R.; Durham, Timothy E.; Vanhille, Kenneth J.

    2015-01-01

    Experimental characterization of the antenna for the Wideband Instrument for Snow Measurements (WISM) under development for the NASA Earth Science Technology Office (ESTO) Instrument Incubator Program (IIP), is discussed. A current sheet antenna, consisting of a small, 6x6 element, dual-linear polarized array with integrated beamformer, feeds an offset parabolic reflector, enabling WISM operation over an 8 to 40 GHz frequency band. An overview of the test program implemented for both the feed and the reflector antenna is given along with select results for specific frequencies utilized by the radar and radiometric sensors of the WISM.

  14. Instrumentation for Measurement: a bilingual lab e-book

    OpenAIRE

    Maria Teresa Restivo; Fernando Gomes Almeida; Maria Fátima Chouzal; Joaquim Mendes; António Mendes Lopes

    2007-01-01

    Instrumentation for Measurement is a relevantsubject in any engineering curriculum. Based on seven years experience in teaching this topic to mechanical engineering students at Faculdade de Engenharia da Universidade do Porto, the authors have prepared an e-book that presents a set of thirteen experimental modules on physical measurements, calibration procedures and metrological concepts. A modular structure permits the most convenient selection according to any course objectives. For each mo...

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

    OpenAIRE

    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...

  16. 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.

  17. 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

  18. 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.

  19. Acoustic Resuspension Measurement System (ARMS): Announcement of Availability.

    Science.gov (United States)

    1992-04-01

    their controlling circuitry to be con,- Z bined in compact, battery -powered packages. These instrument packages can W 0 be contained in rellatively... Station DTIO QUALITY [INSP8•ECTE"•D 4 3909 Halls Ferry Road. Vicksburg, MS 39180-6199 tzqq o- ,1TEDOf’ rYCjA" PiosJ Mr. E. Clark McNair, Jr., (601... Prickett and Michelle M. Thevenot. Introduction In order to measure in situ properties of the boundary layer above dredged material mounds in open

  20. 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.

  1. Logopenic and nonfluent variants of primary progressive aphasia are differentiated by acoustic measures of speech production

    National Research Council Canada - National Science Library

    Ballard, Kirrie J; Savage, Sharon; Leyton, Cristian E; Vogel, Adam P; Hornberger, Michael; Hodges, John R

    2014-01-01

    .... In this study acoustic measures of speech in conjunction with voxel-based morphometry were used to determine the success of the measures as an adjunct to diagnosis and to explore the neural basis...

  2. Compact optical integration instrument to measure intraocular straylight.

    Science.gov (United States)

    Ginis, Harilaos; Sahin, Onurcan; Pennos, Alexandros; Artal, Pablo

    2014-09-01

    Optical measurement of straylight in the human eye is a challenging task. Issues such as illumination geometry, detector sensitivity and dynamic range as well as various inherent artifacts must be addressed. We developed a novel instrument based on the principle of double-pass optical integration adapted for fast measurements in a clinical setting. The experimental setup was validated using four different diffusers introduced in front of the eyes of ten subjects. Measurement limitations and future implications of rapid optical measurement of straylight in ophthalmic diagnosis are discussed.

  3. Design of a compact, low-price, lifetime measuring instrument

    Science.gov (United States)

    Draxler, Sonja; Lippitsch, Max E.; Moeller, Reinhard; Tafeit, Erwin

    1994-08-01

    The technical requirements for a small, rugged, and moderately- priced device for measuring fluorescence lifetimes have been investigated. The suitability and performance of various lifetime measuring schemes were compared. Based on these investigations a compact time-domain instrument was developed allowing measurement of fluorescence decays with a time resolution well below 1 ns. A semiconductor laser (frequency-doubled, if necessary) is used as a light source. Detection is done with a miniaturized photomultiplier. In favorable cases measurement of a fluorescent decay curve is accomplished within less than one minute.

  4. 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

  5. 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.

  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. NEUTRON SCATTERING INSTRUMENTATION FOR MEASUREMENT OF MELT STRUCTURE

    Energy Technology Data Exchange (ETDEWEB)

    Richard Weber, Christopher Benmore

    2004-10-21

    This Phase II research project was focused on constructing and testing a facility for the measurement of the structure of hot solid and liquid materials under extreme conditions using neutron diffraction. The work resulted in measurements at temperatures of 3300 K, the highest ever performed in a neutron beam. Work was performed jointly by Containerless Research, Inc. and Argonne National Laboratory with significant interactions with engineers and scientists at the under construction-SNS facility in Oak Ridge, TN. The work comprised four main activities: Design and construct an advanced instrument for structural studies of liquids and hot solids using neutron scattering. Develop and test a software package for instrument control, data acquisition and analysis. Test and demonstrate the instrument in experiments at the GLAD beamline at IPNS. Evaluate requirements for performing experiments at the SNS. Develop interest from the potential user base and identify potential support for Phase III. The objectives of the research were met. A second-generation instrument was developed and constructed. The instrument design drew on the results of a formal design review which was held at Argonne National Laboratory during the Phase I research [1]. The review included discussion with potential instrument users, SNS scientists and engineers and various scientists involved with materials, glass, ceramics, and geological sciences. The instrument combines aerodynamic levitation with pulsed neutron diffraction in a controlled atmosphere. An important innovation was the use of pure vanadium levitation nozzles that effectively eliminated contributions from the sample environment to the measured data. The instrument employed a 250 Watt CO2 laser that was configured for Class I laser operation. The use of Class I laser configuration meant that operators could work with the equipment with minimal restrictions and so concentrate on the research activities. Instrument control and data

  8. Statistical relations among architectural features and objective acoustical measurements of concert halls

    DEFF Research Database (Denmark)

    Gade, Anders Christian; Siebein, G. W.; Chiang, W.

    1993-01-01

    A statistical analysis of architectural features and detailed objective acoustical measurements made in eight concert halls and several multi-use rooms in their concert configuration will be presented. A method for evaluating the architectural features of rooms that affect their acoustical...

  9. Imaging of acoustic attenuation and speed of sound maps using photoacoustic measurements

    NARCIS (Netherlands)

    Willemink, G.H.; Manohar, S.; Purwar, Y.; Slump, C.H.; Heijden, van der F.; Leeuwen, van T.G.; McAleavey, S.A.; D'Hooge, J.

    2008-01-01

    Photoacoustic imaging is an upcoming medical imaging modality with the potential of imaging both optical and acoustic properties of objects. We present a measurement system and outline reconstruction methods to image both speed of sound and acoustic attenuation distributions of an object using only

  10. 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.

  11. Measuring Baryon Acoustic Oscillations from the clustering of voids

    CERN Document Server

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

    2015-01-01

    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 dependency 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 meth...

  12. 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

  13. Optical radiation measurements for photovoltaic applications: instrumentation uncertainty and performance

    Science.gov (United States)

    Myers, Daryl R.; Reda, Ibrahim; Wilcox, Stephen; Andreas, Afshin

    2004-11-01

    Evaluating the performance of photovoltaic (PV) devices in the laboratory and in the field requires accurate knowledge of the optical radiation stimulating the devices. We briefly describe the radiometric instrumentation used for characterizing broadband and spectral irradiance for PV applications. Spectral radiometric measurement systems are used to characterize solar simulators (continuous and pulsed, or flash sources) and natural sunlight. Broadband radiometers (pyranometers and pyrheliometers) are used to assess solar resources for renewable applications and develop and validate broadband solar radiation models for estimating system performance. We describe the sources and magnitudes of uncertainty associated with calibrations and measuremens using these instruments. The basic calibration and measurement uncertainty associated with this instrumentaion are based on the guidlines described in the International Standards Organization (ISO) and Bureau INternationale des Poids et Mesures (BIPM) Guide to Uncertainty in Measurement. The additional contributions to uncertainty arising from the uncertainty in characterization functions and correction schemes are discussed and ilustrated. Finally, empirical comparisons of several solar radiometer instrumentation sets illustrate that the best measurement accuracy for broadband radiation is on the order of 3%, and spectrally dependent uncertainty for spectroradiometer systems range from 4% in the visible to 8% to 10% in the ultraviolet and infrared.

  14. 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.

  15. Virtual Instrument for Emissions Measurement of Internal Combustion Engines

    Science.gov (United States)

    Pérez, Armando; 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

  16. Instrumentation

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    Journal Scope:Instrumentation is a high quality open access peer reviewed research journal.Authors are solicited to contribute to these journals by submitting articles that illustrate most up-to-date research results,projects,surveying works and industrial experiences that describe significant advances in the instrumental science.The mission of the Instrumentation is

  17. 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.

  18. 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...... with ISO standards. Profiles from the Large range AFM were directly compared with those obtained by a traceable stylus instrument, resulting from probing the same surface region....

  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. 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.

  1. Measurements of the force fields within an acoustic standing wave using holographic optical tweezers

    Energy Technology Data Exchange (ETDEWEB)

    Bassindale, P. G.; Drinkwater, B. W. [Faculty of Engineering, Queens building, University of Bristol, Bristol BS8 1TR (United Kingdom); Phillips, D. B. [Department of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom); Barnes, A. C. [Department of Physics, H.H.Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL (United Kingdom)

    2014-04-21

    Direct measurement of the forces experienced by micro-spheres in an acoustic standing wave device have been obtained using calibrated optical traps generated with holographic optical tweezers. A micro-sphere, which is optically trapped in three dimensions, can be moved through the acoustic device to measure forces acting upon it. When the micro-sphere is subjected to acoustic forces, it's equilibrium position is displaced to a position where the acoustic forces and optical forces are balanced. Once the optical trapping stiffness has been calibrated, observation of this displacement enables a direct measurement of the forces acting upon the micro-sphere. The measured forces are separated into a spatially oscillating component, attributed to the acoustic radiation force, and a constant force, attributed to fluid streaming. As the drive conditions of the acoustic device were varied, oscillating forces (>2.5 pN{sub pp}) and streaming forces (<0.2 pN) were measured. A 5 μm silica micro-sphere was used to characterise a 6.8 MHz standing wave, λ = 220 μm, to a spatial resolution limited by the uncertainty in the positioning of the micro-sphere (here to within 2 nm) and with a force resolution on the order of 10 fN. The results have application in the design and testing of acoustic manipulation devices.

  2. 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.

  3. 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...

  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. Instrumentation

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    Journal Scope:Instrumentation is a high quality open access peer reviewed research journal.Authors are solicited to contribute to these journals by submitting articles that illustrate most up-to-date research results,projects,surveying works and industrial experiences that describe significant advances in the instrumental science.The mission of the Instrumentation is to provide a platform for the researchers,academicians,

  6. Project Vanguard Magnetic-Field Instrumentation and Measurements

    Science.gov (United States)

    Heppner, J. P.; Storarik, J. D.; Shapiro, I. R.; Cain, J. C.

    1960-01-01

    The Vanguard III Satellite, 1959 Eta, placed in orbit on September 18, 1959, contained a proton precessional magnetometer for magnetic-field studies of exceptional accuracy. Throughout the 85 days of battery life, the instrumentation functioned according to plan. Measurements of the absolute total field were obtained in the meridian belts of Minitrack stations at altitudes 510 to 3750 kilometers and at latitudes +/- 33.4 degrees. Surface magnetic observatories were operated at eight of the Minitrack stations to furnish correlative information. This paper reviews briefly the instrumentation employed in these experiments, and the data collection and reduction procedures. Emphasis is given to results from a preliminary analysis. Specifically, this analysis bears on the accuracy of computed fields, the stability of the earth's field in space, the Capetown anomaly, and magnetic-storm effects.

  7. Acoustic Measurement and Model Predictions for the Aural Nondetectability of Two Night-Vision Goggles

    Science.gov (United States)

    2013-11-01

    Acoustic Measurement and Model Predictions for the Aural Nondetectability of Two Night - Vision Goggles by Jeremy Gaston, Tim Mermagen, and...SUBTITLE Acoustic Measurement and Model Predictions for the Aural Nondetectability of Two Night - Vision Goggles 5a. CONTRACT NUMBER 5b. GRANT NUMBER...13. SUPPLEMENTARY NOTES 14. ABSTRACT This study evaluates two different night - vision goggles (NVGs) to determine if the devices meet level II

  8. 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.

  9. 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.

  10. 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.

  11. Fish Acoustics: Physics-Based Modeling and Measurement

    Science.gov (United States)

    2011-01-01

    physical scattering mechanisms. To demonstrate this point, the target strength of a canonical gas-filled sphere is computed using a standard...high-frequency sound scattering by swimbladdered fish,” Journal of the Acoustical Society of America, Vol. 78, pp. 688-700 (1985). 9. Gauss , R. C

  12. Ellipsoidal reflector for measuring oto-acoustic emissions

    DEFF Research Database (Denmark)

    Epp, Bastian; Pulkki, Ville; Heiskanen, Vesa

    2014-01-01

    A truncated prolate ellipsoidal reflector having the ear canal of a listener at one focal point and large- diaphragm low-noise microphone at the other focal point is proposed for free-field recordings of oto-acoustic emissions. A prototype reflector consisting of three pieces is presented, which ...

  13. 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.

  14. 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.

  15. 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

    -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...... experimental animals using nasal cavity models and guinea pigs. Measurement of the nasal cavity models (made of cylindrical silicone tubes) showed that the acoustic rhinometry estimated 85.5% of actual area and 79.0% of actual volume. In guinea pigs, nasal cavity volume determined by the acoustic rhinometry...... the volume and nasal airway resistance in guinea pigs. Measurement of the nasal airway resistance is the method frequently used in the evaluation of the nasal obstruction in guinea pigs. These results suggest that acoustic rhinometry is useful in evaluating nasal obstruction in small experimental animals....

  16. A new instrument to measure plot-scale runoff

    Directory of Open Access Journals (Sweden)

    R. D. Stewart

    2014-11-01

    Full Text Available Accurate measurement of the amount and timing of surface runoff at multiple scales is needed to understand fundamental hydrological processes. At the plot-scale (i.e., length scales on the order of 1 to 10 m current methods for direct measurement of runoff either store the water in a collection vessel, which is unconducive to long-term monitoring studies, or utilize expensive installations such as large-scale tipping buckets or flume/weir systems. We developed an alternative low-cost, robust and reliable instrument to measure runoff that we call the "Upwelling Bernoulli Tube" (UBeTube. The UBeTube instrument is a pipe with a slot machined in its side that is installed vertically at the base of a runoff collection system. The flow rate through the slot is inferred by measuring the water height within the pipe. The geometry of the slot can be modified to suit the range of flow rates expected for a given site; we demonstrate a slot geometry which is capable of measuring flow rates across more than three orders of magnitude (up to 300 L min−1 while requiring only 30 cm of hydraulic head. System accuracy is dependent on both the geometry of the slot and the accuracy of the water level measurements. With an off-the-shelf pressure transducer sensor, the mean theoretical error for the demonstrated slot geometry was ~17% (ranging from errors of more than 50% at low flow rates to less than 2% at high flow rates, while the observed error during validation was 1–25%. A simple correction factor reduced this mean error to −14%, and further reductions in error could be achieved through the use of taller, narrower slot dimensions (which requires greater head gradients to drive flow or through more accurate water level measurements. The UBeTube device has been successfully employed in a long-term rainfall-runoff study, demonstrating the ability of the instrument to measure surface runoff across a range of flows and conditions.

  17. 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.

  18. Instrument maintenance of ultrasonic influences parameters measurement in technological processes

    Directory of Open Access Journals (Sweden)

    Tomal V. S.

    2008-04-01

    Full Text Available The contact and non-contact vibration meters for intermittent and continuous control of the vibration amplitude in the ultrasonic technological equipment have been developed. And in order to estimate the cavitation intensity in liquids the authors have developed cavitation activity indicators and cavitation sensitivity meters, allowing to measure the magnitude of the signal level in the range of maximum spectral density of cavitation noise. The developed instruments allow to improve the quality of products, reduce the defect rate and power consumption of equipment by maintaining optimum conditions of the process.

  19. LEDA beam diagnostics instrumentation: Measurement comparisons and operational experience

    Science.gov (United States)

    Gilpatrick, J. D.; Barr, D.; Bruhn, D.; Day, L. A.; Kasemir, K. U.; Kamperschroer, J. H.; Ledford, J.; Lysenko, W.; Madsen, D. W.; Martinez, D. G.; O'Hara, J. F.; Pieck, M.; Power, J. F.; Sellyey, W.; Shurter, R. B.; Stettler, M. W.

    2000-11-01

    The Low Energy Demonstration Accelerator (LEDA) facility has been used to characterize the pulsed- and cw-beam performance of a 6.7 MeV, 100 mA radio frequency quadrupole (RFQ). Diagnostic instrumentation, primarily located in a short beam transport downstream of the RFQ, allow facility commissioners and operators to measure and monitor the RFQ's accelerated and total beam transmission, beam loss, bunched beam current, beam energy and output phase, and beam position. Transverse beam profile measurements are acquired under both low and high duty-factor pulsed beam conditions using a slow wire scanner and a camera that images beam-induced fluorescence. The wire scanner is also used to acquire transverse beam emittance information using a technique known as a "quad scan". This paper reviews the measurement performance and discusses the resulting data.

  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. 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.

  2. The Ability to Structure Acoustic Material as a Measure of Musical Aptitude. 4. Experiences with Modifications of the Acoustic Structuring Test. Research Bulletin. No. 51.

    Science.gov (United States)

    Karma, Kai

    Four new versions of an acoustic structuring test were developed, administered, and analyzed in order to produce better tests and to contribute to better understanding of the abilities measured by these tests. The tests consist of tape recordings of patterns of musical notes played on an electric organ or an acoustic guitar. Item analyses and…

  3. Acoustic Doppler current profiler measurements in coastal and estuarine environments: examples from the Tay Estuary, Scotland

    Science.gov (United States)

    Wewetzer, Silke F. K.; Duck, Robert W.; Anderson, James M.

    1999-08-01

    Acoustic Doppler current profilers (ADCPs) provide a means to measure the components of water current velocities in three dimensions. Such instruments have been used widely by the oil industry in deep offshore waters but their application to nearshore coastal and estuarine environments has been principally confined to the USA. Using examples of ADCP datasets acquired from the macrotidal Tay Estuary, eastern Scotland, the principles of field deployment, data acquisition and forms of output are critically summarised. It is shown, for the first time in the Tay Estuary, that vertical current velocities are significant and are particularly so in downwelling zones associated with the development and passage of axially convergent tidal fronts. The improved understanding of three-dimensional water and suspended sediment dynamics in coastal and estuarine waters is crucial to, inter alia, the sustainable management of effluent discharges and, in more general terms, it is predicted on the basis of the Tay case study, that ADCP measurements afford significant opportunities to refine understanding of geomorphological processes in a variety of aquatic environments worldwide.

  4. 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.

  5. Quantifying soil CO2 respiration measurement error across instruments

    Science.gov (United States)

    Creelman, C. A.; Nickerson, N. R.; Risk, D. A.

    2010-12-01

    A variety of instrumental methodologies have been developed in an attempt to accurately measure the rate of soil CO2 respiration. Among the most commonly used are the static and dynamic chamber systems. The degree to which these methods misread or perturb the soil CO2 signal, however, is poorly understood. One source of error in particular is the introduction of lateral diffusion due to the disturbance of the steady-state CO2 concentrations. The addition of soil collars to the chamber system attempts to address this perturbation, but may induce additional errors from the increased physical disturbance. Using a numerical 3D soil-atmosphere diffusion model, we are undertaking a comprehensive comparative study of existing static and dynamic chambers, as well as a solid-state CTFD probe. Specifically, we are examining the 3D diffusion errors associated with each method and opportunities for correction. In this study, the impact of collar length, chamber geometry, chamber mixing and diffusion parameters on the magnitude of lateral diffusion around the instrument are quantified in order to provide insight into obtaining more accurate soil respiration estimates. Results suggest that while each method can approximate the true flux rate under idealized conditions, the associated errors can be of a high magnitude and may vary substantially in their sensitivity to these parameters. In some cases, factors such as the collar length and chamber exchange rate used are coupled in their effect on accuracy. Due to the widespread use of these instruments, it is critical that the nature of their biases and inaccuracies be understood in order to inform future development, ensure the accuracy of current measurements and to facilitate inter-comparison between existing datasets.

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. 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....... This is a new way of using the measurement error theory. Reliability ratios illustrate that the models for the two fish species are influenced differently by the error. However, the error seems to influence the predictions of the two reference measures in the same way. The effect of using replicated x......-measurements is illustrated by simulated data and by NMR relaxations measured several times on each fish. The standard error of the Physical determination of the reference values is lower than the standard error of the NMR measurements. In this case, lower prediction error is obtained by replicating the instrumental...

  12. 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.

  13. 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.

  14. 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.

  15. Measurement of the acoustic radiation force on a sphere embedded in a soft solid

    CERN Document Server

    Lidon, Pierre; Taberlet, Nicolas; Manneville, Sébastien

    2016-01-01

    The acoustic radiation force exerted on a small sphere located at the focus of an ultrasonic beam is measured in a soft gel. It is proved to evolve quadratically with the local amplitude of the acoustic field. Strong oscillations of the local pressure are observed and attributed to an acoustic Fabry-P{\\'e}rot effect between the ultrasonic emitter and the sphere. Taking this effect into account with a simple model, a quantitative link between the radiation force and the acoustic pressure is proposed and compared to theoretical predictions in the absence of dissipation. The discrepancy between experiment and theory suggests that dissipative effects should be taken into account for fully modeling the observations.

  16. Reproducibility experiments on measuring acoustical properties of rigid-frame porous media (round-robin tests).

    Science.gov (United States)

    Horoshenkov, Kirill V; Khan, Amir; Bécot, François-Xavier; Jaouen, Luc; Sgard, Franck; Renault, Amélie; Amirouche, Nesrine; Pompoli, Francesco; Prodi, Nicola; Bonfiglio, Paolo; Pispola, Giulio; Asdrubali, Francesco; Hübelt, Jörn; Atalla, Noureddine; Amédin, Celse K; Lauriks, Walter; Boeckx, Laurens

    2007-07-01

    This paper reports the results of reproducibility experiments on the interlaboratory characterization of the acoustical properties of three types of consolidated porous media: granulated porous rubber, reticulated foam, and fiberglass. The measurements are conducted in several independent laboratories in Europe and North America. The studied acoustical characteristics are the surface complex acoustic impedance at normal incidence and plane wave absorption coefficient which are determined using the standard impedance tube method. The paper provides detailed procedures related to sample preparation and installation and it discusses the dispersion in the acoustical material property observed between individual material samples and laboratories. The importance of the boundary conditions, homogeneity of the porous material structure, and stability of the adopted signal processing method are highlighted.

  17. 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.

  18. Acoustics. Measurement of sound insulation in buildings and of building elements. Laboratory measurements of the reduction of transmitted impact noise by floor coverings on a heavyweight standard floor

    CERN Document Server

    British Standards Institution. London

    1998-01-01

    Acoustics. Measurement of sound insulation in buildings and of building elements. Laboratory measurements of the reduction of transmitted impact noise by floor coverings on a heavyweight standard floor

  19. 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.

  20. 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.

  1. Instrument for benzene and toluene emission measurements of glycol regenerators

    Science.gov (United States)

    Hanyecz, Veronika; Mohácsi, Árpád; Puskás, Sándor; Vágó, Árpád; Szabó, Gábor

    2013-11-01

    We introduce an in-field and in-explosive atmosphere useable instrument, which can measure the benzene and toluene concentration in two gas and two glycol samples produced by natural gas dehydration units. It is a two-phase, on-line gas chromatograph with a photoacoustic spectroscopy based detector. The time resolution is 10 min per cycle and the minimum detectable concentrations are 2 mg m-3 for benzene, 3 mg m-3 for toluene in natural gas, and 5 g m-3 for benzene and 6 g m-3 for toluene in glycol. Test measurements were carried out at a dehydration plant belonging to MOL Hungarian Oil and Gas Company. Benzene and toluene emissions of gas dehydration unit are calculated from the measured values based on mass balance of a glycol regenerator. The relationship between the outdoor temperature and the measured concentration was observed which is caused by temperature-dependent operation of the whole dehydration unit. Emission decreases with increase of outdoor temperature.

  2. 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.

  3. Instrumentation

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    Journal Scope:Instrumentation is a high quality open access peer reviewed research journal,Authors are solicited to contribute to these journals by submitting articles that illustrate most up-to-date research results,projects,surveying works and industrial

  4. 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.

  5. 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

  6. 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.

  7. The method of translation additive and multiplicative error in the instrumental component of the measurement uncertainty

    Science.gov (United States)

    Vasilevskyi, Olexander M.; Kucheruk, Volodymyr Y.; Bogachuk, Volodymyr V.; Gromaszek, Konrad; Wójcik, Waldemar; Smailova, Saule; Askarova, Nursanat

    2016-09-01

    The paper proposes a method of conversion additive and multiplicative errors, mathematical models are obtained by a Taylor expansion of the transformation equations used measuring instruments in the instrumental component of the measurement uncertainty.

  8. 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.

  9. Advances in Fast-response Acoustically Derived Air-temperature Measurements

    Science.gov (United States)

    Bogoev, I.; Jacobsen, L.; Horst, T. W.; Conrad, B.

    2015-12-01

    Fast-response accurate air-temperature measurements are required when estimating turbulent fluxes of heat, water and carbon dioxide by open-path eddy-covariance technique. In comparison with contact thermometers like thermocouples, ultra-sonic thermometers do not suffer from solar radiation loading, water vapor condensation and evaporative cooling effects. Consequently they have the potential to provide more accurate true air temperature measurements. The absolute accuracy of the ultrasonic thermometer is limited by the following parameters: the distance between the transducer pairs, transducer delays associated with the electrical-acoustic signal conversion that vary with temperature, components of the wind vector that are normal to the ultrasonic paths, and humidity.The distance between the transducer pairs is commonly obtained by coordinate measuring machine. Improved accuracy demonstrated in this study results from increased stiffness in the anemometer head to better maintain the ultrasonic path-length distances. To further improve accuracy and account for changes in transducer delays and distance as a function of temperature, these parameters are characterized in a zero-wind chamber over the entire operating temperature range. When the sonic anemometer is combined with a co-located fast-response water vapor analyzer, like in the IRGASON instrument, speed of sound can be compensated for humidity effects on a point-by-point basis resulting in a true fast-response air temperature measurement. Laboratory test results show that when the above steps are implemented in the calibration of the ultrasonic thermometer air-temperature accuracy better than ±0.5 degrees Celsius can be achieved over the entire operating range. The approach is also validated in a field inter-comparison with an aspirated thermistor probe mounted in a radiation shield.

  10. Measurement of a broadband negative index with space-coiling acoustic metamaterials.

    Science.gov (United States)

    Xie, Yangbo; Popa, Bogdan-Ioan; Zigoneanu, Lucian; Cummer, Steven A

    2013-04-26

    We report the experimental demonstration of a broadband negative refractive index obtained in a labyrinthine acoustic metamaterial structure. Two different approaches were employed to prove the metamaterial negative index nature: one-dimensional extractions of effective parameters from reflection and transmission measurements and two-dimensional prism-based measurements that convincingly show the transmission angle corresponding to negative refraction. The transmission angles observed in the latter case also agree very well with the refractive index obtained in the one-dimensional measurements and numerical simulations. We expect this labyrinthine metamaterial to become the unit cell of choice for practical acoustic metamaterial devices that require broadband and significantly negative indices of refraction.

  11. Measurement of a Broadband Negative Index with Space-Coiling Acoustic Metamaterials

    Science.gov (United States)

    Xie, Yangbo; Popa, Bogdan-Ioan; Zigoneanu, Lucian; Cummer, Steven A.

    2013-04-01

    We report the experimental demonstration of a broadband negative refractive index obtained in a labyrinthine acoustic metamaterial structure. Two different approaches were employed to prove the metamaterial negative index nature: one-dimensional extractions of effective parameters from reflection and transmission measurements and two-dimensional prism-based measurements that convincingly show the transmission angle corresponding to negative refraction. The transmission angles observed in the latter case also agree very well with the refractive index obtained in the one-dimensional measurements and numerical simulations. We expect this labyrinthine metamaterial to become the unit cell of choice for practical acoustic metamaterial devices that require broadband and significantly negative indices of refraction.

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. Measuring the speed of light with baryon acoustic oscillations.

    Science.gov (United States)

    Salzano, Vincenzo; Dąbrowski, Mariusz P; Lazkoz, Ruth

    2015-03-13

    In this Letter, we describe a new method to use baryon acoustic oscillations (BAO) to derive a constraint on the possible variation of the speed of light. The method relies on the fact that there is a simple relation between the angular diameter distance (D(A)) maximum and the Hubble function (H) evaluated at the same maximum-condition redshift, which includes speed of light c. We note the close analogy of the BAO probe with a laboratory experiment: here we have D(A) which plays the role of a standard (cosmological) ruler, and H^{-1}, with the dimension of time, as a (cosmological) clock. We evaluate if current or future missions such as Euclid can be sensitive enough to detect any variation of c.

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

    Directory of Open Access Journals (Sweden)

    Pasi Pertilä

    2008-07-01

    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.

  20. 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.

  1. 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...

  2. 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.

  3. 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.

  4. 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.

  5. 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…

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. Measurements and empirical model of the acoustic properties of reticulated vitreous carbon

    Science.gov (United States)

    Muehleisen, Ralph T.; Beamer, C. Walter; Tinianov, Brandon D.

    2005-02-01

    Reticulated vitreous carbon (RVC) is a highly porous, rigid, open cell carbon foam structure with a high melting point, good chemical inertness, and low bulk thermal conductivity. For the proper design of acoustic devices such as acoustic absorbers and thermoacoustic stacks and regenerators utilizing RVC, the acoustic properties of RVC must be known. From knowledge of the complex characteristic impedance and wave number most other acoustic properties can be computed. In this investigation, the four-microphone transfer matrix measurement method is used to measure the complex characteristic impedance and wave number for 60 to 300 pore-per-inch RVC foams with flow resistivities from 1759 to 10 782 Pa s m-2 in the frequency range of 330 Hz-2 kHz. The data are found to be poorly predicted by the fibrous material empirical model developed by Delany and Bazley, the open cell plastic foam empirical model developed by Qunli, or the Johnson-Allard microstructural model. A new empirical power law model is developed and is shown to provide good predictions of the acoustic properties over the frequency range of measurement. Uncertainty estimates for the constants of the model are also computed. .

  11. 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...

  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. 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.

  14. 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.

  15. 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.

  16. 基于虚拟仪器的超短基线水声定位系统%USBL acoustic system of based on virtual instrument

    Institute of Scientific and Technical Information of China (English)

    迟寿育

    2012-01-01

    This paper of based on virtual instrument,introduces how to form the ultra short base line locating acoustic system with a oscilloscope and computer connected by Matlab instrument control tool. With the virtual instrument technology expand the function of the traditional instruments, positioning the underwater moving target.%基于虚拟仪器技术,介绍通过Matlab仪器控制工具箱将示波器和计算机结合组成超短基线水声定位系统的方法.用虚拟仪器技术扩展传统仪器的功能,定位水下运动目标.

  17. The measurement of collaboration within healthcare settings: a systematic review of measurement properties of instruments.

    Science.gov (United States)

    Walters, Stephen John; Stern, Cindy; Robertson-Malt, Suzanne

    2016-04-01

    There is a growing call by consumers and governments for healthcare to adopt systems and approaches to care to improve patient safety. Collaboration within healthcare settings is an important factor for improving systems of care. By using validated measurement instruments a standardized approach to assessing collaboration is possible, otherwise it is only an assumption that collaboration is occurring in any healthcare setting. The objective of this review was to evaluate and compare measurement properties of instruments that measure collaboration within healthcare settings, specifically those which have been psychometrically tested and validated. Participants could be healthcare professionals, the patient or any non-professional who contributes to a patient's care, for example, family members, chaplains or orderlies. The term participant type means the designation of any one participant; for example 'nurse', 'social worker' or 'administrator'. More than two participant types was mandatory. The focus of this review was the validity of tools used to measure collaboration within healthcare settings. The types of studies considered for inclusion were validation studies, but quantitative study designs such as randomized controlled trials, controlled trials and case studies were also eligible for inclusion. Studies that focused on Interprofessional Education, were published as an abstract only, contained patient self-reporting only or were not about care delivery were excluded. The outcome of interest was validation and interpretability of the instrument being assessed and included content validity, construct validity and reliability. Interpretability is characterized by statistics such as mean and standard deviation which can be translated to a qualitative meaning. The search strategy aimed to find both published and unpublished studies. A three-step search strategy was utilized in this review. The databases searched included PubMed, CINAHL, Embase, Cochrane Central

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

    OpenAIRE

    Murphy, William J.; Cameron J Fackler; Berger, Elliott H.; Peter B Shaw; Mike Stergar

    2015-01-01

    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 a...

  19. Field acoustic measurements of high-speed train sound along BTIR

    Science.gov (United States)

    Yu, HuaHua; Li, JiaChun

    2013-02-01

    In this paper, single-point field measurements of noise radiated from high-speed trains were performed at two sites along Beijing-Tianjin intercity railway (BTIR), aiming at acquiring the realistic acoustic data for validation and verification of physical model and computational prediction. The measurements showed that A-weighted sound pressure levels (SPLs) were between 80 and 87 dBA as trains passed. The maximum noise occurred at the moment when the pantograph arrived, suggesting that pantograph noise was one of the most significant sources. Sound radiated from high-speed trains of BTIR was a typical broadband spectrum with most acoustic power restricted in the range of medium-high frequency from about 400 Hz to 5 kHz. Aerodynamic noise was shown to be the dominant one over other acoustic sources for high-speed trains.

  20. Guidelines for Acoustical Measurements Inside Historical Opera Houses: Procedures and Validation

    Science.gov (United States)

    POMPOLI, ROBERTO; PRODI, NICOLA

    2000-04-01

    The acoustics of Italian historical theatres is to be regarded as a cultural heritage, which is to be preserved and studied. These actions are imperative for handing down the heritage to future generations and to avoid its loss. In this paper, the technical means for scientific quantification of the acoustical heritage are presented in the form of operative guidelines for acoustical measurements inside historical theatres. The document includes the advice of international experts and is being employed during an extended measurement campaign inside renaissance and baroque historical theatres. A relevant part of the paper deals with the experimental validation of the recommendations given in the guidelines, achieved by a dedicated test session inside the Municipal Theatre of Ferrara.

  1. 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.

  2. Measuring baryon acoustic oscillations with angular two-point correlation function

    CERN Document Server

    Alcaniz, Jailson S; Bernui, Armando; Carvalho, Joel C; Benetti, Micol

    2016-01-01

    The Baryon Acoustic Oscillations (BAO) imprinted a characteristic correlation length in the large-scale structure of the universe that can be used as a standard ruler for mapping out the cosmic expansion history. Here, we discuss the application of the angular two-point correlation function, $w(\\theta)$, to a sample of luminous red galaxies of the Sloan Digital Sky Survey (SDSS) and derive two new measurements of the BAO angular scale at $z = 0.235$ and $z = 0.365$. Since noise and systematics may hinder the identification of the BAO signature in the $w - \\theta$ plane, we also introduce a potential new method to localize the acoustic bump in a model-independent way. We use these new measurements along with previous data to constrain cosmological parameters of dark energy models and to derive a new estimate of the acoustic scale $r_s$.

  3. Measuring Software Test Verification for Complex Workpieces based on Virtual Gear Measuring Instrument

    Directory of Open Access Journals (Sweden)

    Yin Peili

    2017-08-01

    Full Text Available Validity and correctness test verification of the measuring software has been a thorny issue hindering the development of Gear Measuring Instrument (GMI. The main reason is that the software itself is difficult to separate from the rest of the measurement system for independent evaluation. This paper presents a Virtual Gear Measuring Instrument (VGMI to independently validate the measuring software. The triangular patch model with accurately controlled precision was taken as the virtual workpiece and a universal collision detection model was established. The whole process simulation of workpiece measurement is implemented by VGMI replacing GMI and the measuring software is tested in the proposed virtual environment. Taking involute profile measurement procedure as an example, the validity of the software is evaluated based on the simulation results; meanwhile, experiments using the same measuring software are carried out on the involute master in a GMI. The experiment results indicate a consistency of tooth profile deviation and calibration results, thus verifying the accuracy of gear measuring system which includes the measurement procedures. It is shown that the VGMI presented can be applied in the validation of measuring software, providing a new ideal platform for testing of complex workpiece-measuring software without calibrated artifacts.

  4. Measuring Software Test Verification for Complex Workpieces based on Virtual Gear Measuring Instrument

    Science.gov (United States)

    Yin, Peili; Wang, Jianhua; Lu, Chunxia

    2017-08-01

    Validity and correctness test verification of the measuring software has been a thorny issue hindering the development of Gear Measuring Instrument (GMI). The main reason is that the software itself is difficult to separate from the rest of the measurement system for independent evaluation. This paper presents a Virtual Gear Measuring Instrument (VGMI) to independently validate the measuring software. The triangular patch model with accurately controlled precision was taken as the virtual workpiece and a universal collision detection model was established. The whole process simulation of workpiece measurement is implemented by VGMI replacing GMI and the measuring software is tested in the proposed virtual environment. Taking involute profile measurement procedure as an example, the validity of the software is evaluated based on the simulation results; meanwhile, experiments using the same measuring software are carried out on the involute master in a GMI. The experiment results indicate a consistency of tooth profile deviation and calibration results, thus verifying the accuracy of gear measuring system which includes the measurement procedures. It is shown that the VGMI presented can be applied in the validation of measuring software, providing a new ideal platform for testing of complex workpiece-measuring software without calibrated artifacts.

  5. 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-, ...

  6. 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.

  7. 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).

  8. Fabrication and Testing of Viscosity Measuring Instrument (Viscometer

    Directory of Open Access Journals (Sweden)

    A. B. HASSAN

    2006-01-01

    Full Text Available This paper presents the fabrication and testing of a simple and portable viscometer for the measurement of bulk viscosity of different Newtonian fluids. It is aimed at making available the instrument in local markets and consequently reducing or eliminating the prohibitive cost of importation. The method employed is the use of a D.C motor to rotate a disc having holes for infra-red light to pass through and fall on a photo-diode thus undergoing amplification and this signal being translated on a moving-coil meter as a deflection. The motor speed is kept constant but varies with changes in viscosity of the fluid during stirring, which alter signals being read on the meter. The faster is revolution per minute of the disc, the less the deflection on the meter and vise-versa. From the results of tests conducted on various sample fluids using data on standard Newtonian fluids as reliable guide the efficiency of the viscometer was 76.5%.

  9. 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.

  10. Measurement and Characterization of Space Shuttle Solid Rocket Motor Plume Acoustics

    Science.gov (United States)

    Kenny, Jeremy; Hobbs, Chris; Plotkin, Ken; Pilkey, Debbie

    2009-01-01

    Lift-off acoustic environments generated by the future Ares I launch vehicle are assessed by the NASA Marshall Space Flight Center (MSFC) acoustics team using several prediction tools. This acoustic environment is directly caused by the Ares I First Stage booster, powered by the five-segment Reusable Solid Rocket Motor (RSRMV). The RSRMV is a larger-thrust derivative design from the currently used Space Shuttle solid rocket motor, the Reusable Solid Rocket Motor (RSRM). Lift-off acoustics is an integral part of the composite launch vibration environment affecting the Ares launch vehicle and must be assessed to help generate hardware qualification levels and ensure structural integrity of the vehicle during launch and lift-off. Available prediction tools that use free field noise source spectrums as a starting point for generation of lift-off acoustic environments are described in the monograph NASA SP-8072: "Acoustic Loads Generated by the Propulsion System." This monograph uses a reference database for free field noise source spectrums which consist of subscale rocket motor firings, oriented in horizontal static configurations. The phrase "subscale" is appropriate, since the thrust levels of rockets in the reference database are orders of magnitude lower than the current design thrust for the Ares launch family. Thus, extrapolation is needed to extend the various reference curves to match Ares-scale acoustic levels. This extrapolation process yields a subsequent amount of uncertainty added upon the acoustic environment predictions. As the Ares launch vehicle design schedule progresses, it is important to take every opportunity to lower prediction uncertainty and subsequently increase prediction accuracy. Never before in NASA s history has plume acoustics been measured for large scale solid rocket motors. Approximately twice a year, the RSRM prime vendor, ATK Launch Systems, static fires an assembled RSRM motor in a horizontal configuration at their test facility

  11. 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.

  12. 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.

  13. Acoustic absorption measurement of human hair and skin within the audible frequency range.

    Science.gov (United States)

    Katz, B F

    2000-11-01

    Utilizing the two-microphone impedance tube method, the acoustic absorption of human skin and hair is measured in the frequency range 1-6 kHz. Various locations on a number of human subjects are measured to determine if the presence of bone or an air pocket affects the acoustic absorption of human skin. The absorption coefficient of human hair is also measured. Additional techniques are utilized to minimize errors due to sample mounting methods. Techniques are employed to minimize potential errors in sensor and sample locations. The results of these measurements are compared to relevant historical papers on similar investigations. Results for skin measurements compare well with previous work. Measured hair absorption data do not agree with previous work in the area but do coincide with expected trends, which previous works do not.

  14. 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.

  15. Comparisons between Computer Simulations of Room Acoustical Parameters and those Measured in Concert Halls

    DEFF Research Database (Denmark)

    Rindel, Jens Holger; Shiokawa, Hiroyoshi; Christensen, Claus Lynge;

    1999-01-01

    A number of European concert halls were surveyed in 1989. In this paper comparisons are made between measured room acoustical parameters and those obtained from computer simulations using the ODEON program version 3.1 on two concert halls. One is Musikverein in Vienna and the other is Concertgebo...

  16. 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

  17. Measurement and Modeling of the Acoustic Response in a High Pressure Combustor

    NARCIS (Netherlands)

    Kapucu, M.; Kapucu, Mehmet; Alemela, P.R.; Kok, Jacobus B.W.; Pozarlik, Artur Krzysztof

    2011-01-01

    In this paper, a one dimensional acoustic network model is presented which can be used as a design tool to predict the limit cycle pressure oscillations in a gas turbine combustor. Analytically represented models are combined with measured flame transfer functions and well defined boundary condition

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

    NARCIS (Netherlands)

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

    2014-01-01

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

  19. 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.

  20. On the local plane wave methods for in situ measurement of acoustic absorption

    NARCIS (Netherlands)

    Wijnant, Y.H.

    2015-01-01

    In this paper we address a series of so-called local plane wave methods (LPW) to measure acoustic absorption. As opposed to other methods, these methods do not rely on assumptions of the global sound field, like e.g. a plane wave or diffuse field, but are based on a local plane wave assumption. Ther

  1. A Multidimensional Investigation of Children's /r/ Productions: Perceptual, Ultrasound, and Acoustic Measures

    Science.gov (United States)

    Klein, Harriet B.; McAllister Byun, Tara; Davidson, Lisa; Grigos, Maria I.

    2013-01-01

    Purpose: This study explored relationships among perceptual, ultrasound, and acoustic measurements of children's correct and misarticulated /r/ sounds. Longitudinal data documenting changes across these parameters were collected from 2 children who acquired /r/ over a period of intervention and were compared with data from children with typical…

  2. Modal measurements and propeller field excitation on acoustic full scale mockup of SAAB 340 aircraft

    Science.gov (United States)

    Gustavsson, Lars

    1992-06-01

    The acoustic mockup of the cabin SAAB 340 aircraft was measured in an anechoic chamber concerning modal parameters and operating deflection shapes. The mockup was excited with vibration shakers at the fuselage for modal estimation and with a ring of loudspeakers around the fuselage to generate propeller fields for operating deflection shapes. Two cases of structure configuration were used at the measurements; one consisting of only the fuselage, without trimpanels and floorpanels and one case with trimpanels and floorpanels. Modal measurements were done with excitation on a frame of the fuselage at the propeller plane. The modes were estimated for the individual components; fuselage, trimpanels, floorpanels, and soundfield in the cabin. The modes of the fuselage were compared with the acoustic models in the cabin concerning possible coupling effects. With the loudspeakering, the sound field from the left and the right propeller were generated at a blade passage frequency of 81.9 Hz and its first harmonic. Operating deflection shapes of fuselage, panels, and cabin acoustic were estimated. The results from the measurements could be used to verify a finite element model and as a tool for developing acoustic noise control systems.

  3. 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.

  4. 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.

  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. Comparative study about the determination of the Young's modulus of thin layers with the instrumented indentation test and the laser-acoustic measuring method%纳米压痕仪和激光超声技术检测薄膜弹性模量

    Institute of Scientific and Technical Information of China (English)

    陈倩栎; Konrad Herrmann; Febo Menelao

    2007-01-01

    在薄膜材料的力学性能测定中,弹性模量是衡量材料软硬程度的重要指标.为了测定弹性模量,本文选取不同种类和厚度的金属薄膜材料,采用纳米压痕技术(nanoindentation)和激光超声技术(laser-acoustics)两种测试方法相互比较,以确保测试的准确性.两种方法在膜厚较大的试样测试中得到了大致相符的试验结果,相对误差最小达到2%.

  7. Comparisons between computer simulations of room acoustical parameters and those measured in concert halls

    DEFF Research Database (Denmark)

    Rindel, Jens Holger; Shiokawa, Hiroyoshi; Christensen, Claus Lynge;

    1999-01-01

    A number of European concert halls were surveyed in 1989. In this paper comparisons are made between measured room acoustical parameters and those obtained from computer simulations on concert halls using the odeon program version 3.1. The key parameter compared with measured data is the reverber......A number of European concert halls were surveyed in 1989. In this paper comparisons are made between measured room acoustical parameters and those obtained from computer simulations on concert halls using the odeon program version 3.1. The key parameter compared with measured data...... is the reverberation time, and this is mainly used to adjust the absorption data of the surfaces in the computer model. But five additional parameters are calculated and compared with measured data as well. In order to determine the sensitivity of the computer model, comparisons are also made between the results...

  8. ACOUSTIC EMISSION ANALYZER

    Directory of Open Access Journals (Sweden)

    J. J. Almeida-Pérez

    2004-12-01

    Full Text Available In this paper appears a solution for acoustic emission analysis commonly known as noise. For the accomplishmentof this work a personal computer is used, besides sensors (microphones and boards designed and built for signalconditioning. These components are part of a virtual instrument used for monitoring the acoustical emission. Themain goal of this work is to develop a virtual instrument that supplies many important data as the result of ananalysis allowing to have information in an easy and friendly way. Moreover this information is very useful forstudying and resolving several situations in planning, production and testing areas.The main characteristics of the virtual instrument are: signal analysis in time, effective power measurement inDecibels (dB, average intensity taken from the principle of paired microphones, as well as the data analysis infrequency. These characteristics are included to handle two information channels.

  9. 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)

  10. Acoustic-Seismic Coupling in Porous Ground - Measurements and Analysis for On-Site-Inspection Support

    Science.gov (United States)

    Liebsch, Mattes; Gorschlüter, Felix; Altmann, Jürgen

    2014-05-01

    During on-site inspections (OSI) of the Comprehensive Nuclear Test Ban Treaty Organisation (CTBTO) a local seismic network can be installed to measure seismic aftershock signals of an assumed underground nuclear explosion. These signals are caused by relaxation processes in and near the cavity created by the explosion and when detected can lead to a localisation of the cavity. This localisation is necessary to take gas samples from the ground which are analysed for radioactive noble gas isotopes to confirm or dismiss the suspicion of a nuclear test. The aftershock signals are of very low magnitude so they can be masked by different sources, in particular periodic disturbances caused by vehicles and aircraft in the inspection area. Vehicles and aircraft (mainly helicopters) will be used for the inspection activities themselves, e.g. for overhead imagery or magnetic-anomaly sensing. While vehicles in contact with the ground can excite soil vibrations directly, aircraft and vehicles alike emit acoustic waves which excite soil vibrations when hitting the ground. These disturbing signals are of periodic nature while the seismic aftershock signals are pulse-shaped, so their separation is possible. The understanding of the coupling of acoustic waves to the ground is yet incomplete, a better understanding is necessary to improve the performance of an OSI, e.g. to address potential consequences for the sensor placement, the helicopter trajectories etc. In a project funded by the Young Scientist Research Award of the CTBTO to one of us (ML), we investigated the acoustic-seismic coupling of airborne signals of jet aircraft and artificially induced ones by a speaker. During a measurement campaign several acoustic and seismic sensors were placed below the take-off trajectory of an airport at 4 km distance. Therefore taking off and landing jet aircraft passed nearly straightly above the setup. Microphones were placed close to the ground to record the sound pressure of incident

  11. 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.

  12. Relationship between acoustic measures and judgments of intelligibility in Parkinson’s disease: A within-speaker approach

    Science.gov (United States)

    FEENAUGHTY, LYNDA; TJADEN, KRIS; SUSSMAN, JOAN

    2017-01-01

    This study investigated the acoustic basis of within-speaker, across-utterance variation in sentence intelligibility for 12 speakers with dysarthria secondary to Parkinson’s disease (PD). Acoustic measures were also obtained for 12 healthy controls for comparison to speakers with PD. Speakers read sentences using their typical speech style. Acoustic measures of speech rate, articulatory rate, fundamental frequency, sound pressure level and F2 interquartile range (F2 IQR) were obtained. A group of listeners judged sentence intelligibility using a computerized visual-analog scale. Relationships between judgments of intelligibility and acoustic measures were determined for individual speakers with PD. Relationships among acoustic measures were also quantified. Although considerable variability was noted, articulatory rate, fundamental frequency and F2 IQR were most frequently associated with within-speaker variation in sentence intelligibility. Results suggest that diversity among speakers with PD should be considered when interpreting results from group analyses. PMID:24874184

  13. 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.

  14. 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.

  15. 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

    In this study, the acoustic emission activity of cement pastes was investigated during the first day of hydration. Deaired, fresh cement pastes were cast in sealed sample holders designed to minimize friction and restraint. The majority of acoustic emission events occurred in lower water to cement....... 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...

  16. The acoustic environment of intensive care wards based on long period nocturnal measurements

    Directory of Open Access Journals (Sweden)

    Hui Xie

    2012-01-01

    Full Text Available The patients in the Intensive Care Units are often exposed to excessive levels of noise and activities. They can suffer from sleep disturbance, especially at night, but they are often too ill to cope with the poor environment. This article investigates the acoustic environment of typical intensive care wards in the UK, based on long period nocturnal measurements, and examines the differences between singlebed and multibed wards, using statistical analysis. It has been shown that the acoustic environment differs significantly every night. There are also significant differences between the noise levels in the singlebed and multibed wards, where acoustic ceilings are present. Despite the similar background noises in both ward types, more intrusive noises tend to originate from the multibed wards, while more extreme sounds are likely to occur in the single wards. The sound levels in the measured wards for each night are in excess of the World Health Organization′s (WHO guide levels by at least 20 dBA, dominantly at the middle frequencies. Although the sound level at night varies less than that in the daytime, the nocturnal acoustic environment is not dependant on any specific time, thus neither the noisiest nor quietest period can be determined. It is expected that the statistical analysis of the collected data will provide essential information for the development of relevant guidelines and noise reduction strategies.

  17. The acoustic environment of intensive care wards based on long period nocturnal measurements.

    Science.gov (United States)

    Xie, Hui; Kang, Jian

    2012-01-01

    The patients in the Intensive Care Units are often exposed to excessive levels of noise and activities. They can suffer from sleep disturbance, especially at night, but they are often too ill to cope with the poor environment. This article investigates the acoustic environment of typical intensive care wards in the UK, based on long period nocturnal measurements, and examines the differences between singlebed and multibed wards, using statistical analysis. It has been shown that the acoustic environment differs significantly every night. There are also significant differences between the noise levels in the singlebed and multibed wards, where acoustic ceilings are present. Despite the similar background noises in both ward types, more intrusive noises tend to originate from the multibed wards, while more extreme sounds are likely to occur in the single wards. The sound levels in the measured wards for each night are in excess of the World Health Organization's (WHO) guide levels by at least 20 dBA, dominantly at the middle frequencies. Although the sound level at night varies less than that in the daytime, the nocturnal acoustic environment is not dependant on any specific time, thus neither the noisiest nor quietest period can be determined. It is expected that the statistical analysis of the collected data will provide essential information for the development of relevant guidelines and noise reduction strategies.

  18. Integration of acoustic radiation force and optical imaging for blood plasma clot stiffness measurement.

    Science.gov (United States)

    Wang, Caroline W; Perez, Matthew J; Helmke, Brian P; Viola, Francesco; Lawrence, Michael B

    2015-01-01

    Despite the life-preserving function blood clotting serves in the body, inadequate or excessive blood clot stiffness has been associated with life-threatening diseases such as stroke, hemorrhage, and heart attack. The relationship between blood clot stiffness and vascular diseases underscores the importance of quantifying the magnitude and kinetics of blood's transformation from a fluid to a viscoelastic solid. To measure blood plasma clot stiffness, we have developed a method that uses ultrasound acoustic radiation force (ARF) to induce micron-scaled displacements (1-500 μm) on microbeads suspended in blood plasma. The displacements were detected by optical microscopy and took place within a micro-liter sized clot region formed within a larger volume (2 mL sample) to minimize container surface effects. Modulation of the ultrasound generated acoustic radiation force allowed stiffness measurements to be made in blood plasma from before its gel point to the stage where it was a fully developed viscoelastic solid. A 0.5 wt % agarose hydrogel was 9.8-fold stiffer than the plasma (platelet-rich) clot at 1 h post-kaolin stimulus. The acoustic radiation force microbead method was sensitive to the presence of platelets and strength of coagulation stimulus. Platelet depletion reduced clot stiffness 6.9 fold relative to platelet rich plasma. The sensitivity of acoustic radiation force based stiffness assessment may allow for studying platelet regulation of both incipient and mature clot mechanical properties.

  19. Determination of efficiency of anechoic or decoupling hull coatings using water tank acoustic measurements

    OpenAIRE

    AUDOLY, Christian

    2012-01-01

    International audience; External anechoic and decoupling hull coatings are used on ships or submarines to reduce acoustic target strength and radiated noise, respectively. Measurement of test panels in a water tank gives only the reflection and transmission coefficients in free field, with respects to frequency. It is shown using simple models that anechoic and decoupling efficiencies can be derived, providing appropriate modulus and phase measurement of the coefficients. Additionnally, the i...

  20. Laser and acoustic Doppler techniques for the measurement of fluid velocities

    Science.gov (United States)

    Cliff, W. C.

    1975-01-01

    An overview of current laser and acoustic Doppler techniques is presented. Results obtained by Doppler anemometry and conventional sensors are compared. Comparisons include simultaneous velocity measurements by hot wire and a three-dimensional laser anemometer made in a gaseous pipe flow as well as direct comparisons of atmospheric velocities measured with propeller and cup anemometry. Scanning techniques are also discussed. Conclusions and recommendations for future work are presented.

  1. Measuring Quality of Life: A New and Practical Survey Instrument.

    Science.gov (United States)

    Greenley, James R.; Greenberg, Jan Steven; Brown, Roger

    1997-01-01

    Presents a new, short, self-administered questionnaire that assesses the quality of life in seven areas. Evidence for the reliability and validity of the questionnaire was based on data gathered from 971 clients; results indicate instrument reliability. The questionnaire features low-cost administration and valid psychometric properties. (RJM)

  2. SHIM-Free Breadboard Instrument Design, Integration, and First Measurements

    Science.gov (United States)

    2005-11-23

    The concept is similar to a Michelson interferometer with the return mirrors replaced by fixed, tilted diffraction gratings. Figure 1 shows the basic...Cardon, R.R. Conway, C.M. Brown, J. Wimperis, "Robust monolithic ultraviolet interferometer for the SHIMMER instrument on STPSat-l," Applied Optics, 42

  3. Logopenic and Nonfluent Variants of Primary Progressive Aphasia Are Differentiated by Acoustic Measures of Speech Production: e89864

    National Research Council Canada - National Science Library

    Kirrie J Ballard; Sharon Savage; Cristian E Leyton; Adam P Vogel; Michael Hornberger; John R Hodges

    2014-01-01

    .... In this study acoustic measures of speech in conjunction with voxel-based morphometry were used to determine the success of the measures as an adjunct to diagnosis and to explore the neural basis...

  4. Acoustic Measurements of Residual Stresses and Grain Sizes in Aluminum Alloys

    Science.gov (United States)

    Fisher, Martin John

    The theory of acoustoelasticity relates the velocity of an acoustic wave in a solid to the elastic stress state in that solid. This thesis presents new theories, measurement techniques, and methodologies related to the use of longitudinal wave acoustoelasticity in aluminum alloys. A one-dimensional model has been developed to provide a simple understanding of the acoustoelastic effect. A new acoustic device for accurately measuring relative thickness variations has been designed and built. This device is used--in conjunction with a pulse-echo phase measurement device and a computer controlled scanning system--to measure acoustic velocity variations in plastically deformed and non-flat-and-parallel samples. Acoustic velocity variations from point to point in an unstressed sample can sometimes be on the same order as velocity changes due to applied or residual stresses, and this can make stress measurements difficult. A statistical theory has been developed to relate these unstressed velocity variations to the average grain size in the sample and to the active area of the acoustic transducer used. Large transducers and small grain sizes will minimize these variations. This relationship has been verified by tests on a number of aluminum alloys and a new method for non-destructive grain size determination has been suggested. A systematic methodology has been developed and tested for studying the influence of uniaxial plastic deformation on the acoustoelastic response. Samples have been plastically deformed in four-point bending to produce elastic-plastic and residual stress states. Acoustic measurements of these stresses have then been compared directly to theoretical predictions based on the materials' stress-strain curves and simple beam theory. In the aluminum alloys tested (2024-T351 and 7075-T651), the acoustoelastic constants are shown to be virtually unchanged by uniaxial plastic strains of less than 2.5%. Thus, the acoustoelastic technique can be reliably

  5. 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

  6. Clinical value of acoustic voice measures: a retrospective study.

    Science.gov (United States)

    Werth, Katrin; Voigt, Daniel; Döllinger, Michael; Eysholdt, Ulrich; Lohscheller, Jörg

    2010-08-01

    Within this study a retrospective analysis of clinical voice perturbation measures, Dysphonia Severity Index and subjective perceived hoarseness was performed to determine their value under clinical aspects. The study included the data of 580 healthy and 1,700 pathologic voices, which were investigated under the following aspects. The relevant parameters were identified and their interrelation determined. Group differences between healthy and pathologic voices were figured out and investigated if voice quality measures allowed an automatic diagnosis of voice disorders. The analysis revealed significant changes between the clinical groups, which indicate the diagnostic relevance of voice quality measures. However, an individual diagnosis of the underlying voice disorder failed due to a vast spread of the parameter values within the respective groups. Classification accuracies of 75-90% were achieved. The high misclassification rate of up to 25% implied that in voice disorder diagnosis, the individual interpretation of the parameter values has to be done carefully.

  7. Measurement of ultrasonic nonlinear parameter by using electromagnetic acoustic transducer

    Science.gov (United States)

    Cai, Zhichao; Liu, Suzhen; Zhang, Chuang

    2017-02-01

    The nonlinear ultrasonic technology is generally known as an effective method for the microcrack detection. However, most of the previous experimental studies were limited by a contact nonlinearity method. Since measurement by the contact method is affected by the coupling conditions, additional nonlinear coefficient are lead into the measurement. This research presents a novel technique for nonlinear ultrasonic wave measurements that uses a non-contact electromagnetic ultrasonic transducer (EMAT). And for a better understanding and a more in-depth analysis of the macroscopic nonlinear behavior of microcrack, the developed FEM modeling approach was built to simulate microcrack induced nonlinearities manifested in electromagnetic ultrasonic waves and validated experimentally. This study has yielded a quantitative characterization strategy for microcrack using EMAT, facilitating deployment of structural health monitoring by noncontact electromagnetic nondestructive testing.

  8. A modified beam-to-earth transformation to measure short-wavelength internal waves with an acoustic Doppler current profiler

    Science.gov (United States)

    Scotti, A.; Butman, B.; Beardsley, R.C.; Alexander, P.S.; Anderson, S.

    2005-01-01

    The algorithm used to transform velocity signals from beam coordinates to earth coordinates in an acoustic Doppler current profiler (ADCP) relies on the assumption that the currents are uniform over the horizontal distance separating the beams. This condition may be violated by (nonlinear) internal waves, which can have wavelengths as small as 100-200 m. In this case, the standard algorithm combines velocities measured at different phases of a wave and produces horizontal velocities that increasingly differ from true velocities with distance from the ADCP. Observations made in Massachusetts Bay show that currents measured with a bottom-mounted upward-looking ADCP during periods when short-wavelength internal waves are present differ significantly from currents measured by point current meters, except very close to the instrument. These periods are flagged with high error velocities by the standard ADCP algorithm. In this paper measurements from the four spatially diverging beams and the backscatter intensity signal are used to calculate the propagation direction and celerity of the internal waves. Once this information is known, a modified beam-to-earth transformation that combines appropriately lagged beam measurements can be used to obtain current estimates in earth coordinates that compare well with pointwise measurements. ?? 2005 American Meteorological Society.

  9. Acoustical and optical backscatter measurements of sediment transport in the 1988 1989 STRESS experiment

    Science.gov (United States)

    Lynch, J. F.; Gross, T. F.; Sherwood, C. R.; Irish, J. D.; Brumley, B. H.

    1997-04-01

    During the 1988-1989 Sediment Transport Events on Shelves and Slopes (STRESS) experiment, a 1-MHz acoustic backscatter system (ABSS), deployed in 90 m of water off the California coast measured vertical profiles of suspended sediment concentration from 1.5 to (nominally) 26 meters above bottom (m.a.b.). An 8-week-long time series was obtained, showing major sediment transport events (storms) in late December and early January. Comparison of the acoustics measurements from 1.5 m.a.b. are made with optical backscatter system (OBS) concentration estimates lower in the boundary layer (0.25 m.a.b.). Correlations between ABSS and OBS concentration measurements and the boundary layer forcing functions (waves, currents, and their non-linear interaction) provided a variety of insights into the nature of the sediment transport of the STRESS site. Transport rates and integrated transport are seen to be dominated by the largest storm events.

  10. 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.

  11. Measurement of incident sound power using near field acoustic holography

    DEFF Research Database (Denmark)

    Jacobsen, Finn; Tiana Roig, Elisabet

    2009-01-01

    The conventional method of measuring the insertion loss of a partition relies on an assumption of the sound field in the source room being diffuse and the classical relation between the spatial average of the mean square pressure in the source room and the incident sound power per unit area...

  12. 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

    sine signal and is tested on models of memoryless nonlinear systems as well as nonlinear loudspeakers. The method is shown to give a clear benefit over existing methods. Two techniques that improve the signal-to-noise ratio are demonstrated: the first uses more measurement levels than the number...

  13. The relationship between VHI scores and specific acoustic measures of mildly disordered voice production.

    Science.gov (United States)

    Wheeler, Karen M; Collins, Savita P; Sapienza, Christine M

    2006-06-01

    This study was designed to examine the relationship between the Voice Handicap Index (VHI) and acoustic measures of voice samples common in clinical practice. Fifty participants, 38 women and 12 men, ranging in age from 19 to 80 years, with a mean age of 49 years, served as participants. Of these 50 participants, 17 participants could be included in the acoustic analysis of voice based on measures of error calculated with the TF32 software. All participants completed the VHI and provided voice samples including three trials of the sustained vowel /A/ at a comfortable loudness level as well as a connected speech sample consisting of the Zoo Passage. Acoustic measures were made with TF32 and Cool Edit software and included fundamental frequency, jitter %, shimmer %, signal-to-noise ratio, mean root-mean-square intensity, fundamental frequency standard deviation, aphonic periods, and breath groups. Results indicate that these measures were not predictive of overall VHI score, and no cohesive or predictable pattern was identified when comparing individual measures with overall VHI or with each subscale item. Likely contributions to this lack of correlation and subsequent clinical implications are discussed, as well as the direction for further research.

  14. Valid instrument for measuring quality of life in youth: VIHDA

    Directory of Open Access Journals (Sweden)

    José Joaquín Martínez Lozano

    2015-12-01

    Full Text Available The article presents the validity and reliability of VIDHAB instrument, its objective is to evaluate the quality of urban life of the youth of the municipality of Cucuta, Colombia. Follows a descriptive study design validation through multidimensional scaling factor analysis, construct validity, and face. The study population were people aged 18-28 in Cucuta, the sample comprised 1180 habitants. Results: a scale of 57 items was obtained. Factor analysis showed dimensions of life satisfaction, quality of public space, poverty rate, perception of public space; Internal consistency was adequate (Cronbach's alpha 0.81 to 0.89, overall intraclass correlation coefficient of 0.967 (95%, from 0.933 to 0.984, average sum of differences in items -1.3 (SD: 8.5 and Kappa indices above 0.86 shows high agreement among experts. Conclusion: VIDHAB is a valid and reliable for the context Cucuta, Colombia instrument.

  15. Age effects in the human middle ear: Wideband acoustical measures

    Science.gov (United States)

    Feeney, M. Patrick; Sanford, Chris A.

    2004-12-01

    Studies that have examined age effects in the human middle ear using either admittance measures at 220 or 660 Hz or multifrequency tympanometry from 200 to 2000 Hz have had conflicting results. Several studies have suggested an increase in admittance with age, while several others have suggested a decrease in admittance with age. A third group of studies found no significant age effect. This study examined 226 Hz tympanometry and wideband energy reflectance and impedance at ambient pressure in a group of 40 young adults and a group of 30 adults with age >=60 years. The groups did not differ in admittance measures of the middle ear at 226 Hz. However, significant age effects were found in wideband energy reflectance and impedance. In particular, in older adults there was a comparative decrease in reflectance from 800 to 2000 Hz but an increase near 4000 Hz. The results suggest a decrease in middle-ear stiffness with age. The findings of this study hold relevance for understanding the aging process in the auditory system, for the establishment of normative data for wideband energy reflectance, for the possibility of a conductive component to presbycusis, and for the interpretation of otoacoustic emission measurements. .

  16. Measuring Pilot Proficiency on an Instrument Training Maneuver

    Science.gov (United States)

    1977-08-01

    featmr• of the Advanced Simulator for Pilot Training ( ASPT ) could be suc- cess tuj ly used to facilitate the development and validation of a recording...for the instrument training maneuver Vertical S-A in which the unique record/playback features of the Advanced Simulator for Pilot Training ( ASPT ) were...the ASPT revealed several format and observe--workload problems that needed correction. SFollowing revision, the booklet (Appendix A) was given a

  17. Synthetic aperture acoustic measurements of stationary suspended cinderblock and surrogate substitutes

    Science.gov (United States)

    Bishop, Steven; Woods, Teresa; Vignola, Joe; Judge, John; Soumekh, Mehrdad

    2009-05-01

    A synthetic aperture acoustic approach is used as a standoff method to assess material properties of a typical cinder block, referred to as a concrete masonry unit (CMU), and a variety of CMU surrogates. The objective is to identify anomalies in CMU wall surfaces. The acoustic specular return and phase change across the blocks are the fundamental measurements of interest. The CMU surrogates are created from commercially available closed cell expanding foam. Results from three test articles are presented that show potentially exploitable differences in terms of acoustic magnitude and acoustic phase response between the surrogates and typical CMUs. The test articles are; a typical CMU, a foam block, and a foam block with an embedded steel object. All test articles are similar in size and shape, and both foam blocks are covered in grout so that surface appearance closely matches that of a CMU. The results show that each of the test articles has characteristics that may be used for discrimination and anomaly detection.

  18. A novel multipitch measurement algorithm for acoustic signals of moving targets

    Science.gov (United States)

    Huang, Jingchang; Guo, Feng; Zu, Xingshui; Li, Haiyan; Liu, Huawei; Li, Baoqing

    2016-12-01

    In this paper, a novel multipitch measurement (MPM) method is proposed for acoustic signals. Starting from the analysis of moving targets' acoustic signatures, a pitch-based harmonics representation model of acoustic signal is put forward. According to the proposed harmonics model, a modified greatest common divisor (MGCD) method is developed to obtain an initial multipitch set (IMS). Subsequently, the harmonic number vector (HNV) associated with the IMS is determined by maximizing the objective function formulated as a multi-impulse-train weighted symmetric average magnitude sum function (SAMSF) of the observed signal. The frequencies of SAMSF are determined by the target acoustic signal, the periods of the multi-impulse-train are governed by the estimated IMS harmonics and the maximization of the objective function is figured out through a time-domain matching of periodicities of the multi-impulse-train with that of the SAMSF. Finally, by using the obtained IMS and its HNV, a precise fundamental frequency set is achieved. Evaluation of the algorithm performances in comparison with state-of-the-art methods indicates that MPM is practical for the multipitch extraction of moving targets.

  19. A Martian acoustic anemometer.

    Science.gov (United States)

    Banfield, Don; Schindel, David W; Tarr, Steve; Dissly, Richard W

    2016-08-01

    An acoustic anemometer for use on Mars has been developed. To understand the processes that control the interaction between surface and atmosphere on Mars, not only the mean winds, but also the turbulent boundary layer, the fluxes of momentum, heat and molecular constituents between surface and atmosphere must be measured. Terrestrially this is done with acoustic anemometers, but the low density atmosphere on Mars makes it challenging to adapt such an instrument for use on Mars. This has been achieved using capacitive transducers and pulse compression, and was successfully demonstrated on a stratospheric balloon (simulating the Martian environment) and in a dedicated Mars Wind Tunnel facility. This instrument achieves a measurement accuracy of ∼5 cm/s with an update rate of >20 Hz under Martian conditions.

  20. Agri-environmental policy measures in Israel: the potential of using market-oriented instruments.

    Science.gov (United States)

    Amdur, Liron; Bertke, Elke; Freese, Jan; Marggraf, Rainer

    2011-05-01

    This paper examines the possibilities of developing agri-environmental policy measures in Israel, focusing on market-oriented instruments. A conceptual framework for developing agri-environmental policy measures is presented, first in very broad lines (mandatory regulations, economic instruments and advisory measures) and subsequently focusing on economic instruments, and specifically, on market-oriented ones. Two criteria of choice between the measures are suggested: their contribution to improving the effectiveness of the policy; and the feasibility of their implementation. This is the framework used for analyzing agri-environmental measures in Israel. Israel currently implements a mix of mandatory regulations, economic instruments and advisory measures to promote the agri-environment. The use of additional economic instruments may improve the effectiveness of the policy. When comparing the effectiveness of various economic measures, we found that the feasibility of implementation of market-oriented instruments is greater, due to the Israeli public's preference for strengthening market orientation in the agricultural sector. Four market-oriented instruments were practiced in a pilot project conducted in an Israeli rural area. We found that in this case study, the institutional feasibility and acceptance by stakeholders were the major parameters influencing the implementation of the market-oriented instruments, whereas the instruments' contribution to enhancing the ecological or economic effectiveness were hardly considered by the stakeholders as arguments in favor of their use.

  1. 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.

  2. Characterizing Three-Dimensional Mixing Process in a River Confluence using Hydro-acoustical Backscatter and Flow Measurement

    Science.gov (United States)

    Son, Geunsoo; Kim, Dongsu; Kim, YoungDo; Lyu, Siwan; Kim, Seojun

    2017-04-01

    concentration by using acoustic backscatter. Cross-sectional ADCP measurements in a confluence were collected with high spatial resolution in order to analyze the details of spatial distribution in the perspective of the three-dimensional mixing patterns of flow and sediment, where backscatters (or SNR) measured from ADCPs were used to track sediment mixing assuming that it could be a surrogate to estimate the suspended sediment concentration. Raw backscatter data were corrected by considering the beam spreading and absorption by water. Also, an optical Laser diffraction instrument (LISST) was used to verify the method of acoustic backscatter and to collect the particle size distribution of main stream and tributary. In addition, image-based spatial distributions of sediment mixture in the confluence were monitored in various flow conditions by using an unmanned aerial vehicle (UAV), which were compared with the spatial distribution of acoustic backscatter. As results, we found that when acoustic backscatter and flow measurements by ADCPs were well processed, they could be proper indicators to identify the spatial patterns of the three-dimensional mixing process between two rivers.

  3. Initiation of GPS-Acoustics Measurements on the Continental Slope of the Cascadia Subduction Zone

    Science.gov (United States)

    Chadwell, C. D.

    2016-12-01

    Land-based GPS measurements suggest the megathrust is locked offshore along the Cascadia Subduction Zone. However, land-based data alone lack geometric resolution to constrain the how the slip is distributed. GPS-Acoustic measurements can provide these constraints, but using traditional GPS-Acoustic approaches employing a ship is costly. Wave Gliders, a wave- and solar-powered, remotely-piloted sea surface platform, provide a low cost method for collecting GPS-A data. We have adapted GPS-Acoustic technology to the Wave Glider. In July 2016, the GPS-A Wave Glider was launched on month-long mission to two sites on the continental slope of the Cascadia Subduction Zone. One site is approximately 45 NM offshore central Oregon and the other approximately 50 NM offshore central Washington State. We will report on initial results of the GPS-A data collection and operational experiences of the mission. Wave Glider based GPS-A measurement have the potential to significantly increase the number and frequency of measurements of strain accumulation in Cascadia Subduction Zone and elsewhere.

  4. Brillouin-scattering measurements of the acoustic absorption coefficient in liquid CS2

    Science.gov (United States)

    Coakley, R. W.; Detenbeck, R. W.

    1975-01-01

    High-resolution Brillouin spectra were recorded for light scattered at small angles from liquid CS2. The use of a single-mode He-Ne laser, locked in frequency to a Fabry-Perot interferometer, permitted measurements of line widths of the order of 10 MHz for frequencies in the range 300-1000 MHz. These measurements extend previous Brillouin line-width measurements at higher frequencies into the region where relaxation effects are dominant and connect the optical measurements with lower-frequency acoustical data.

  5. 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

  6. 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.

  7. Measurement of low-frequency ultrasonic wave in water using an acoustic fiber sensor.

    Science.gov (United States)

    Sakoda, Tatsuya; Sonoda, Yoshito

    2006-04-01

    An acoustic fiber sensor for measurement of ultrasonic waves, which used the approximate Raman-Nath diffraction effect where light diffraction waves were generated in an optical fiber by strain due to the ultrasonic waves, was proposed and examined. In order to characterize the acoustic fiber sensor as a basic study, measurements of low-frequency ultrasonic waves in water were examined using a step index fiber operating as a detection sensor. The results showed that characteristics of detected signals agreed with the theoretical prediction based on Fraunhofer diffraction. This indicates that our proposed fiber sensor can be used for the detection of low-frequency ultrasonic waves as well as the transmission of light diffraction signals.

  8. 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

  9. An Electronic Measurement Instrumentation of the Impedance of a Loaded Fuel Cell or Battery

    OpenAIRE

    2007-01-01

    In this paper we present an inexpensive electronic measurement instrumentation developed in our laboratory, to measure and plot the impedance of a loaded fuel cell or battery. Impedance measurements were taken by using the load modulation method. This instrumentation has been developed around a VXI system stand which controls electronic cards. Software under Hpvee® was developed for automatic measurements and the layout of the impedance of the fuel cell on load. The measurement environment, l...

  10. 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).

  11. Hearing preservation in acoustic neuroma resection: Analysis of petrous bone measurement and intraoperative application

    Directory of Open Access Journals (Sweden)

    Levent Tanrikulu

    2016-01-01

    Conclusion: Petrous bone measurement by high-resolution MRI data enables safe surgical exposure of the internal acoustic canal with avoidance of injury to the labyrinth and a better postoperative prognosis, especially for intrameatal ANs and for the resection of intrameatal portions of larger neuromas. The prognostic factors enable the patients and the surgeon a better estimation of postoperative results regarding deafness and postoperative hypacusis and support a consolidated treatment planning.

  12. [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.

  13. Technology as an instrument to measure the school cohabitation

    Directory of Open Access Journals (Sweden)

    Nelsón Javier Correa Romero

    2010-01-01

    Full Text Available To face the enormous social changes that are underway, the assertive communication is of a great importance for the human coexistence, therefore, it is vital the search for novel ways to mediate among the forms of interactions generated from the services internet is offering. Through participant observations, interviews, analysis of documents and diverse strategies to innovate the coexistence, it is possible to establish “Technology as a mediate instrument for the school coexistence”, which uses the modern communication as a tool to face the school conflicts among equals, and as a way of active participation.

  14. Self-administered health literacy instruments for people with diabetes: systematic review of measurement properties.

    Science.gov (United States)

    Lee, Eun-Hyun; Kim, Chun-Ja; Lee, Jiyeon; Moon, Seung Hei

    2017-09-01

    The aims of this study were to identify all available self-administered instruments measuring health literacy in people with diabetes and to determine the current instrument that is the most appropriate for applying to this population in both practice and research. A systematic review of measurement properties. MEDLINE, EMBASE and CINAHL electronic databases from their inception up to 28 March 2016. The methodological quality of each included study was assessed using the COnsensus-based Standards for the selection of health Measurement INstruments checklist. The reported results for measurement properties in the studies were assessed according to Terwee's quality criteria. Thirteen self-administered instruments measuring health literacy in people with diabetes were identified, of which six (44%) were diabetes-specific instruments. The instruments that covered the broadest contents of health literacy were the Health Literacy Scale and Health Literacy Questionnaire. The (test-retest) reliability, measurement error and responsiveness were not evaluated for any instrument, while internal consistency and hypothesis testing validity were the most frequently assessed measurement properties. With the current evidence, the Health Literacy Scale may be the most appropriate instrument for patients with diabetes in practice and research. However, the structural validity of this scale needs to be further established, particularly in other language versions. It is also recommended to use the Diabetes Numeracy Test-15 along with the Health Literacy Scale to complement the lack of numeracy measures in the Health Literacy Scale. © 2017 John Wiley & Sons Ltd.

  15. 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…

  16. An Instrument to Measure the Cognitive Ability Evaluation of the Taxonomy.

    Science.gov (United States)

    Schaff, John F.

    Described is the development of an instrument designed to measure the cognitive ability of evaluation in high school chemistry students. The instrument was composed of several situations found in chemistry courses, each designed to measure a student's evaluation ability based on his knowledge of kinetic-molecular theory as it applied to gases,…

  17. 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

  18. 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…

  19. 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

  20. Gene Expression Measurement Module (GEMM) - a fully automated, miniaturized instrument for measuring gene expression in space

    Science.gov (United States)

    Karouia, Fathi; Ricco, Antonio; Pohorille, Andrew; Peyvan, Kianoosh

    2012-07-01

    The capability to measure gene expression on board spacecrafts opens the doors to a large number of experiments on the influence of space environment on biological systems that will profoundly impact our ability to conduct safe and effective space travel, and might also shed light on terrestrial physiology or biological function and human disease and aging processes. 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, determine metabolic basis of microbial pathogenicity and drug resistance, 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, and monitor both the spacecraft environment and crew health. These and other applications hold significant potential for discoveries in space biology, biotechnology and medicine. Accordingly, 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 measuring microbial expression of thousands of genes from multiple samples. The instrument will be capable of (1) lysing bacterial cell walls, (2) extracting and purifying RNA released from cells, (3) hybridizing it on a microarray and (4) providing electrochemical readout, all in a microfluidics cartridge. The prototype under development is suitable for deployment on nanosatellite platforms developed by the NASA Small Spacecraft Office. The first target application is to cultivate and measure gene expression of the photosynthetic bacterium Synechococcus elongatus, i.e. a cyanobacterium known to exhibit remarkable metabolic diversity and resilience to adverse conditions

  1. 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

  2. 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).

  3. Direct voltage measurements using bulk acoustic wave sensing in LiNbO3

    Science.gov (United States)

    Patel, Nishant Bhupendra

    Accurate (impedance effects that can distort the pulse shape, and pickup of extraneous signals resulting from electromagnetic interference effects. A piezoelectric crystal-based bulk acoustic wave sensor using lithium niobate (LiNbO3) that has applications to metrology, research, and power metering was developed to overcome these measurement issues with the factors of scalability, ease of use, and compactness in mind. A Y+36° cut LiNbO3crystal was coupled to two acoustic transducers, where direct current (DC) voltages ranging from 128--1100 V were applied transversely to the crystal. An acoustic wave was used to interrogate the crystal before, during, and after voltage application. Both single and multiple pass measurements were performed and compared to linear piezoelectric theory. A comparison study between Y+36° and 0° X-cut LiNbO3 was performed to evaluate the influence of crystal cut on acoustic propagation. The study was extended to applying alternating current (AC), and pulsed voltages. The measured DC data was compared to a 1-D impedance matrix model that was based on a three port circuit with voltage-induced strain effects inputted as a model parameter. An uncertainty budget was carried out for both crystal cuts and compared. Environmental effects such as pressure and temperature were also measured to determine their influence on the sensor under ambient conditions. Published literature regarding material constants, such as elastic constants and piezoelectric constants, for LiNbO3 do not account for the influence of an electric field. In light of this, measurements of the acoustic velocities and material constants under the presence of a DC electric field were performed up to 896 V. This information was used to develop an uncertainty analysis for the determination of stress-charge form piezoelectric constants e15 and e22. All measured and calculated values were input into a Monte Carlo simulation to determine the error of the strain-charge form

  4. 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.

  5. The development of an integrated assessment instrument for measuring analytical thinking and science process skills

    Science.gov (United States)

    Irwanto, Rohaeti, Eli; LFX, Endang Widjajanti; Suyanta

    2017-05-01

    This research aims to develop instrument and determine the characteristics of an integrated assessment instrument. This research uses 4-D model, which includes define, design, develop, and disseminate. The primary product is validated by expert judgment, tested it's readability by students, and assessed it's feasibility by chemistry teachers. This research involved 246 students of grade XI of four senior high schools in Yogyakarta, Indonesia. Data collection techniques include interview, questionnaire, and test. Data collection instruments include interview guideline, item validation sheet, users' response questionnaire, instrument readability questionnaire, and essay test. The results show that the integrated assessment instrument has Aiken validity value of 0.95. Item reliability was 0.99 and person reliability was 0.69. Teachers' response to the integrated assessment instrument is very good. Therefore, the integrated assessment instrument is feasible to be applied to measure the students' analytical thinking and science process skills.

  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.

  7. Quantifying acoustic doppler current profiler discharge uncertainty: A Monte Carlo based tool for moving-boat measurements

    Science.gov (United States)

    Mueller, David S.

    2017-01-01

    This paper presents a method using Monte Carlo simulations for assessing uncertainty of moving-boat acoustic Doppler current profiler (ADCP) discharge measurements using a software tool known as QUant, which was developed for this purpose. Analysis was performed on 10 data sets from four Water Survey of Canada gauging stations in order to evaluate the relative contribution of a range of error sources to the total estimated uncertainty. The factors that differed among data sets included the fraction of unmeasured discharge relative to the total discharge, flow nonuniformity, and operator decisions about instrument programming and measurement cross section. As anticipated, it was found that the estimated uncertainty is dominated by uncertainty of the discharge in the unmeasured areas, highlighting the importance of appropriate selection of the site, the instrument, and the user inputs required to estimate the unmeasured discharge. The main contributor to uncertainty was invalid data, but spatial inhomogeneity in water velocity and bottom-track velocity also contributed, as did variation in the edge velocity, uncertainty in the edge distances, edge coefficients, and the top and bottom extrapolation methods. To a lesser extent, spatial inhomogeneity in the bottom depth also contributed to the total uncertainty, as did uncertainty in the ADCP draft at shallow sites. The estimated uncertainties from QUant can be used to assess the adequacy of standard operating procedures. They also provide quantitative feedback to the ADCP operators about the quality of their measurements, indicating which parameters are contributing most to uncertainty, and perhaps even highlighting ways in which uncertainty can be reduced. Additionally, QUant can be used to account for self-dependent error sources such as heading errors, which are a function of heading. The results demonstrate the importance of a Monte Carlo method tool such as QUant for quantifying random and bias errors when

  8. 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.

  9. Evaluation of stage acoustics in Seoul Arts Center Concert Hall by measuring stage support.

    Science.gov (United States)

    Jeon, Jin Yong; Barron, Michael

    2005-01-01

    Stage acoustics is an important characteristic for concert halls, both for the acoustic quality on stage and for the audience. However, relatively little research has been conducted into the question. This study was based on the investigation of an actual concert hall stage, that of the Seoul Arts Center Concert Hall in Korea. The stage acoustics was evaluated in the actual hall, and with two models: a 1:25 scale model and a computer model. The study was based on the stage support parameter ST1 proposed by Gade as a measure of support for individual performers [Acustica 65, 193-203 (1989)]. The variation of support was measured on the empty stage of the actual hall and in the two models. The effect of musicians on stage, the effect of moving the orchestra, the effect of ceiling height and of stage-wall profile were also investigated. Conclusions are drawn both relating to the Seoul Concert Hall stage and stages in general.

  10. Acoustic harmonic generation measurement applications: Detection of tight cracks in powder metallurgy compacts

    Science.gov (United States)

    Barnard, D. J.; Foley, J. C.

    2000-05-01

    Standard linear ultrasonic testing techniques have long been employed for locating and characterizing relatively open cracks in a wide variety of materials, from metallic alloys and ceramics to composites. In all these materials, the detection of open cracks easily accomplished because the void between the two crack surfaces provides sufficient acoustic impedance mismatch to reflect the incident energy. Closed or partially closed cracks, however, may often go undetected because contacting interfaces allow transmission of ultrasound. In the green (unsintered) state, powder metallurgy compacts typically contain high residual stresses that have the ability to close cracks formed during the compaction process, a result of oxide films, improper powder lubricant, mold design, etc. After sintering, the reduction of residual stresses may no longer be sufficient to close the crack. Although the crack may be more easily detected, it is obvious most desirable to discover defects prior to sintering. It has been shown that the displacements of an interface may be highly nonlinear if a stress wave of sufficient intensity propagates across it, a result of the stress wave either opening or closing the interface. Current efforts involve the application of nonlinear acoustic techniques, in particular acoustic harmonic generation measurements, for the detection and characterization of tightly closed cracks in powder metallurgy parts. A description of the equipment and the measurement technique will be discussed and initial experimental results on sintered and green compacts will be presented.—This work was performed at the Ames Laboratory, Iowa State University under USDOE Contract No. W-7405-ENG-82.

  11. Fish species identification based on its acoustic target strength using in situ measurement

    Directory of Open Access Journals (Sweden)

    Raja-Bidin Raja-Hassan

    2010-11-01

    Full Text Available The purpose of this study is fish species identification using acoustic target strength (TS. Insitu measurement has been deployed at the South China Sea of Terengganu Malaysia using Furuno FQ-80 Scientific Echo Sounder which included in the research vessel of KK Senangin II. The transducer isplaced 2.8 meter under sea surface while fish put in the net cage under the vessel. TS data have beencollected independently for commercial fish in Malaysia, there are Selar boops (Oxeye scad, Alepesdjedaba (Shrimp scad, Megalaspis cordyla (Torpedo scad, and Decapterus maruadsi/b> (Japanese scad.TS value, depth, and position of specific target have been observed using echogram. TS of every speciesis different although similar size and at the similar range from transducer. Thus, the specific fish specieshas been identified based on its acoustic target strength.

  12. Measurements of Finite Dust Temperature Effects in the Dispersion Relation of the Dust Acoustic Wave

    Science.gov (United States)

    Snipes, Erica; Williams, Jeremiah

    2009-04-01

    A dusty plasma is a four-component system composed of ions, electrons, neutral particles and charged microparticles. The presence of these charged microparticles gives rise to new plasma wave modes, including the dust acoustic wave. Recent measurements [1, 2] of the dispersion relationship for the dust acoustic wave in a glow discharge have shown that finite temperature effects are observed at higher values of neutral pressure. Other work [3] has shown that these effects are not observed at lower values of neutral pressure. We present the results of ongoing work examining finite temperature effects in the dispersion relation as a function of neutral pressure. [4pt] [1] E. Thomas, Jr., R. Fisher, and R. L. Merlino, Phys. Plasmas 14, 123701 (2007). [0pt] [2] J. D. Williams, E. Thomas Jr., and L. Marcus, Phys. Plasmas 15, 043704 (2008). [0pt] [3] T. Trottenberg, D. Block, and A. Piel, Phys. Plasmas 13, 042105 (2006).

  13. A Tool Measuring Remaining Thickness of Notched Acoustic Cavities in Primary Reaction Control Thruster NDI Standards

    Science.gov (United States)

    Sun, Yushi; Sun, Changhong; Zhu, Harry; Wincheski, Buzz

    2006-01-01

    Stress corrosion cracking in the relief radius area of a space shuttle primary reaction control thruster is an issue of concern. The current approach for monitoring of potential crack growth is nondestructive inspection (NDI) of remaining thickness (RT) to the acoustic cavities using an eddy current or remote field eddy current probe. EDM manufacturers have difficulty in providing accurate RT calibration standards. Significant error in the RT values of NDI calibration standards could lead to a mistaken judgment of cracking condition of a thruster under inspection. A tool based on eddy current principle has been developed to measure the RT at each acoustic cavity of a calibration standard in order to validate that the standard meets the sample design criteria.

  14. 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...

  15. 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

  16. New Concepts in Instrumentation Development to Measure the Perry Scheme.

    Science.gov (United States)

    Taylor, Marcia

    The Perry scheme of intellectual and ethical development has become widely used in a range of academic disciplines and such areas as career training and faculty consultation. However, current measurement techniques for the scheme, whether interview format or paper and pencil measures, do not adequately address issues related to assessing cognitive…

  17. 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

  18. 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 ...

  19. Tensile strain measurements of ceramic fibers using scanning laser acoustic microscopy

    Science.gov (United States)

    Kent, Renee M.; Vary, Alex

    1992-01-01

    A noncontacting technique using scanning laser acoustic microscopy for making in situ tensile strain measurements of small diameter fibers was implemented for the tensile strain analysis of individual Nicalon SiC fibers (nominal diameter 15 microns). Stress vs strain curves for the fibers were plotted from the experimental data. The mean elastic modulus of the fibers was determined to be 185.3 GPa. Similar measurements were made for Carborundum SiC fibers (nominal diameter 28 microns) and Saphikon sapphire fibers (nominal diameter 140 microns).

  20. 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.

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

    Science.gov (United States)

    Murphy, William J; Fackler, Cameron J; Berger, Elliott H; Shaw, Peter B; Stergar, Mike

    2015-01-01

    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.

  2. 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.

  3. 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.

  4. 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 ...

  5. Absolute viscosity measured using instrumented parallel plate system

    Science.gov (United States)

    Broyles, H. H.

    1967-01-01

    An automatic system measures the true average shear viscosity of liquids and viscoelastic materials, using the parallel plate method and automatically displays the results on a graphic record. This eliminates apparatus setup and extensive calculations.

  6. A new automatic system for angular measurement and calibration in radiometric instruments.

    Science.gov (United States)

    Marquez, Jose Manuel Andujar; Bohórquez, Miguel Ángel Martínez; Garcia, Jonathan Medina; Nieto, Francisco Jose Aguilar

    2010-01-01

    This paper puts forward the design, construction and testing of a new automatic system for angular-response measurement and calibration in radiometric instruments. Its main characteristics include precision, speed, resolution, noise immunity, easy programming and operation. The developed system calculates the cosine error of the radiometer under test by means of a virtual instrument, from the measures it takes and through a mathematical procedure, thus allowing correcting the radiometer with the aim of preventing cosine error in its measurements.

  7. A New Automatic System for Angular Measurement and Calibration in Radiometric Instruments

    Directory of Open Access Journals (Sweden)

    Jose Manuel Andujar Marquez

    2010-04-01

    Full Text Available This paper puts forward the design, construction and testing of a new automatic system for angular-response measurement and calibration in radiometric instruments. Its main characteristics include precision, speed, resolution, noise immunity, easy programming and operation. The developed system calculates the cosine error of the radiometer under test by means of a virtual instrument, from the measures it takes and through a mathematical procedure, thus allowing correcting the radiometer with the aim of preventing cosine error in its measurements.

  8. 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{\

  9. 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.

  10. 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.

  11. 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...

  12. Remote vibration measurement: a wireless passive surface acoustic wave resonator fast probing strategy.

    Science.gov (United States)

    Friedt, J-M; Droit, C; Ballandras, S; Alzuaga, S; Martin, G; Sandoz, P

    2012-05-01

    Surface acoustic wave (SAW) resonators can advantageously operate as passive sensors which can be interrogated through a wireless link. Amongst the practical applications of such devices, structural health monitoring through stress measurement and more generally vibration characteristics of mechanical structures benefit from the ability to bury such sensors within the considered structure (wireless and battery-less). However, measurement bandwidth becomes a significant challenge when measuring wideband vibration characteristics of mechanical structures. A fast SAW resonator measurement scheme is demonstrated here. The measurement bandwidth is limited by the physical settling time of the resonator (Q/π periods), requiring only two probe pulses through a monostatic RADAR-like electronic setup to identify the sensor resonance frequency and hence stress on a resonator acting as a strain gauge. A measurement update rate of 4800 Hz using a high quality factor SAW resonator operating in the 434 MHz Industrial, Scientific and Medical band is experimentally demonstrated.

  13. 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.

  14. Physical Activity Measurement Instruments for Children with Cerebral Palsy: A Systematic Review

    Science.gov (United States)

    Capio, Catherine M.; Sit, Cindy H. P.; Abernethy, Bruce; Rotor, Esmerita R.

    2010-01-01

    Aim: This paper is a systematic review of physical activity measurement instruments for field-based studies involving children with cerebral palsy (CP). Method: Database searches using PubMed Central, MEDLINE, CINAHL Plus, PsycINFO, EMBASE, Cochrane Library, and PEDro located 12 research papers, identifying seven instruments that met the inclusion…

  15. 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…

  16. The PROactive instruments to measure physical activity in patients with chronic obstructive pulmonary disease

    NARCIS (Netherlands)

    Gimeno-Santos, Elena; Raste, Yogini; Demeyer, Heleen; Louvaris, Zafeiris; de Jong, Corina; Rabinovich, Roberto A.; Hopkinson, Nicholas S.; Polkey, Michael I.; Vogiatzis, Ioannis; Tabberer, Maggie; Dobbels, Fabienne; Ivanoff, Nathalie; de Boer, Willem I.; van der Molen, Thys; Kulich, Karoly; Serra, Ignasi; Basagana, Xavier; Troosters, Thierry; Puhan, Milo A.; Karlsson, Niklas; Garcia-Aymerich, Judith

    2015-01-01

    No current patient-centred instrument captures all dimensions of physical activity in chronic obstructive pulmonary disease (COPD). Our objective was item reduction and initial validation of two instruments to measure physical activity in COPD. Physical activity was assessed in a 6-week, randomised,

  17. 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

  18. 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.…

  19. 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

  20. 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

  1. Validation of an Instrument to Measure Students' Motivation and Self-Regulation towards Technology Learning

    Science.gov (United States)

    Liou, Pey-Yan; Kuo, Pei-Jung

    2014-01-01

    Background: Few studies have examined students' attitudinal perceptions of technology. There is no appropriate instrument to measure senior high school students' motivation and self-regulation toward technology learning among the current existing instruments in the field of technology education. Purpose: The present study is to validate an…

  2. The PROactive instruments to measure physical activity in patients with chronic obstructive pulmonary disease

    NARCIS (Netherlands)

    Gimeno-Santos, Elena; Raste, Yogini; Demeyer, Heleen; Louvaris, Zafeiris; de Jong, Corina; Rabinovich, Roberto A.; Hopkinson, Nicholas S.; Polkey, Michael I.; Vogiatzis, Ioannis; Tabberer, Maggie; Dobbels, Fabienne; Ivanoff, Nathalie; de Boer, Willem I.; van der Molen, Thys; Kulich, Karoly; Serra, Ignasi; Basagana, Xavier; Troosters, Thierry; Puhan, Milo A.; Karlsson, Niklas; Garcia-Aymerich, Judith

    2015-01-01

    No current patient-centred instrument captures all dimensions of physical activity in chronic obstructive pulmonary disease (COPD). Our objective was item reduction and initial validation of two instruments to measure physical activity in COPD. Physical activity was assessed in a 6-week, randomised,

  3. Designing Chemistry Practice Exams for Enhanced Benefits: An Instrument for Comparing Performance and Mental Effort Measures

    Science.gov (United States)

    Knaus, Karen J.; Murphy, Kristen L.; Holme, Thomas A.

    2009-01-01

    The design and use of a chemistry practice exam instrument that includes a measure for student mental effort is described in this paper. Use of such an instrument can beneficial to chemistry students and chemistry educators as well as chemical education researchers from both a content and cognitive science perspective. The method for calculating…

  4. 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

  5. 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

  6. Reflectances from a supercontinuum laser-based instrument: hyperspectral, polarimetric and angular measurements.

    Science.gov (United States)

    Ceolato, Romain; Riviere, Nicolas; Hespel, Laurent

    2012-12-31

    Recent developments of active hyperspectral systems require optical characterization of man-made materials for instrument calibration. This work presents an original supercontinuum laser-based instrument designed by Onera, The French Aerospace Lab, for fast hyperspectral polarimetric and angular reflectances measurements. The spectral range is from 480 nm to 1000 nm with a 1 nm spectral resolution. Different polarization configurations are made possible in whole spectrum. This paper reviews the design and the calibration of the instrument. Hyper-spectral polarimetric and angular reflectances are measured for reference and man-made materials such as paint coatings. Physical properties of reflectances as positivity, energy conservation and Helmholtz reciprocity are retrieved from measurements.

  7. Reliability of Instruments Measuring At-Risk and Problem Gambling Among Young Individuals

    DEFF Research Database (Denmark)

    Edgren, Robert; Castrén, Sari; Mäkelä, Marjukka

    2016-01-01

    Info covering the years 2009–2015. In total, 50 original research articles fulfilled the inclusion criteria: target age under 29 years, using an instrument designed for youth, and reporting a reliability estimate. Articles were evaluated with the revised Quality Assessment of Diagnostic Accuracy Studies tool...... instruments for youth have not been rigorously evaluated yet. Further research is needed especially concerning instruments designed for clinical use.......This review aims to clarify which instruments measuring at-risk and problem gambling (ARPG) among youth are reliable and valid in light of reported estimates of internal consistency, classification accuracy, and psychometric properties. A systematic search was conducted in PubMed, Medline, and Psyc...

  8. 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.

  9. Measuring Certified Registered Nurse Anesthetist Organizational Climate: Instrument Adaptation.

    Science.gov (United States)

    Boyd, Donald; Poghosyan, Lusine

    2017-08-01

    No tool exists measuring certified registered nurse anesthetist (CRNA) organizational climate. The study's purpose is to adapt a validated tool to measure CRNA organizational climate. Content validity of the Certified Registered Nurse Anesthetist Organizational Climate Questionnaire (CRNA-OCQ) was established. Pilot testing was conducted to determine internal reliability consistency of the subscales. Experts rated the tool as content valid. The subscales had high internal consistency reliability (with respective Cronbach's alphas): CRNA-Anesthesiologist Relations (.753), CRNA-Physician Relations (.833), CRNA-Administration Relations (.895), Independent Practice (.830), Support for CRNA Practice (.683), and Professional Visibility (.772). Further refinement of the CRNA-OCQ is necessary. Measurement and assessment of CRNA organizational climate may produce evidence needed to improve provider and patient outcomes.

  10. INSTRUMENTATION FOR MEASURING AND TRANSMISSION THE SOLAR RADIATION THROUGH EARTH’S ATMOSPHERE

    Directory of Open Access Journals (Sweden)

    Alexandru Dan Toma

    2013-07-01

    Full Text Available The Sun's energy is distributed over a broad range of the electromagnetic spectrum and Sun behaves approximately like a "blackbody" radiating at a temperature of about 5800 K with maximum output in the green-yellow part of the visible spectrum, around 500 nm. Not all solar radiation reaching the top of the atmosphere reaches Earth's surface due to a various optical phenomena in regard to solar radiation crossing the Earth’s atmosphere. In order to investigate them, there are two general categories of instruments used to measure the transmission of solar radiation through Earth's atmosphere: instruments that measure radiation from the entire sky and instruments that measure only direct solar radiation. Within each of these categories, instruments can be further subdivided into those that measure radiation over a broad range of wavelengths and those that measure only specific wavelengths.

  11. Practical resolution requirements of measurement instruments for precise characterization of autostereoscopic 3D displays

    Science.gov (United States)

    Boher, Pierre; Leroux, Thierry; Collomb-Patton, Véronique; Bignon, Thibault

    2014-03-01

    Different ways to evaluate the optical performances of auto-stereoscopic 3D displays are reviewed. Special attention is paid to the crosstalk measurements that can be performed by measuring, either the precise angular emission at one or few locations on the display surface, or the full display surface emission from very specific locations in front of the display. Using measurements made in the two ways with different instruments on different auto-stereoscopic displays, we show that measurement instruments need to match the resolution of the human eye to obtain reliable results in both cases. Practical requirements in terms of angular resolution for viewing angle measurement instruments and in terms of spatial resolution for imaging instruments are derived and verified on practical examples.

  12. 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,…

  13. 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…

  14. 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…

  15. 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…

  16. Assessing medical professionalism: A systematic review of instruments and their measurement properties.

    Science.gov (United States)

    Li, Honghe; Ding, Ning; Zhang, Yuanyuan; Liu, Yang; Wen, Deliang

    2017-01-01

    Over the last three decades, various instruments were developed and employed to assess medical professionalism, but their measurement properties have yet to be fully evaluated. This study aimed to systematically evaluate these instruments' measurement properties and the methodological quality of their related studies within a universally acceptable standardized framework and then provide corresponding recommendations. A systematic search of the electronic databases PubMed, Web of Science, and PsycINFO was conducted to collect studies published from 1990-2015. After screening titles, abstracts, and full texts for eligibility, the articles included in this study were classified according to their respective instrument's usage. A two-phase assessment was conducted: 1) methodological quality was assessed by following the COnsensus-based Standards for the selection of health status Measurement INstruments (COSMIN) checklist; and 2) the quality of measurement properties was assessed according to Terwee's criteria. Results were integrated using best-evidence synthesis to look for recommendable instruments. After screening 2,959 records, 74 instruments from 80 existing studies were included. The overall methodological quality of these studies was unsatisfactory, with reasons including but not limited to unknown missing data, inadequate sample sizes, and vague hypotheses. Content validity, cross-cultural validity, and criterion validity were either unreported or negative ratings in most studies. Based on best-evidence synthesis, three instruments were recommended: Hisar's instrument for nursing students, Nurse Practitioners' Roles and Competencies Scale, and Perceived Faculty Competency Inventory. Although instruments measuring medical professionalism are diverse, only a limited number of studies were methodologically sound. Future studies should give priority to systematically improving the performance of existing instruments and to longitudinal studies.

  17. E-MODULE DEVELOPMENT FOR THE SUBJECT OF MEASURING INSTRUMENTS AND MEASUREMENT IN ELECTRONICS ENGINEERING EDUCATION

    Directory of Open Access Journals (Sweden)

    Nuryake Fajaryati

    2016-09-01

    Full Text Available This study aims to develop an e-module as a medium of learning for the practice course of Measuring Instruments and Measurement in the Department of Electronics Engineering Education of Yogyakarta State University and to determine the feasibility of the e-module. This study employed a method of research and development. The development process was conducted through four phases by using the model of Lee and Owens which consisted of analysis phase, design phase, developing and implementation phase, as well as evaluation phase.The evaluation was conducted in several stages. Firstly, an alpha test for product validation was conducted by the experts on material and media. After that, a beta test was conducted by testing the product in small group users. The subjects of this study were the students of Electronics Engineering. The instruments used to collect the data were a validation sheet and questionnaires. The results of qualitative data were then modified into quantitative data with a range of 1 to 5, then they were converted with a rating scale to determine the feasibility of the medium. The results showed that based on the alpha test, the medium was in a very high quality. Meanwhile, in the beta test of the instructional aspect, in terms of material and evaluation and the multimedia aspect the e-module was respectively considered feasible and quite feasible. The four indicators namely text, image, animation and video were all generally considered feasible. In terms of usage aspect, the e-module was considered feasible where its two indicators, namely instructions and navigation, were generally regarded as very feasible by all respondents.

  18. 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.

  19. A Critical Review of Instruments Measuring Breastfeeding Attitudes, Knowledge, and Social Support.

    Science.gov (United States)

    Casal, Corrine S; Lei, Ann; Young, Sera L; Tuthill, Emily L

    2017-02-01

    Breastfeeding provides beneficial health outcomes for infants and their mothers, and increasing its practice is a national priority in many countries. Despite increasing support to exclusively breastfeed, the prevalence at 6 months remains low. Breastfeeding behavior is influenced by a myriad of determinants, including breastfeeding attitudes, knowledge, and social support. Effective measurement of these determinants is critical to provide optimal support for women throughout the breastfeeding period. However, there are a multitude of available instruments measuring these constructs, which makes identification of an appropriate instrument challenging. Research aim: Our aim was to identify and critically examine the existing instruments measuring breastfeeding attitudes, knowledge, and social support. A total of 16 instruments was identified. Each instrument's purpose, theoretical underpinnings, and validity were analyzed. An overview, validation and adaptation for use in other settings was assessed for each instrument. Depth of reporting and validation testing differed greatly between instruments. Content, construct, and predictive validity were present for most but not all scales. When selecting and adapting instruments, attention should be paid to domains within the scale, number of items, and adaptation.

  20. 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.

  1. AmeriFlux Measurement Component (AMC) Instrument Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Reichl, Ken [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Biraud, Sebastien C [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2016-04-01

    An AMC system was installed at the U.S. Department of Energy (DOE)’s Atmospheric Radiation Measurement (ARM) Climate Research Facility North Slope of Alaska (NSA) Barrow site, also known as NSA C1 at the ARM Data Archive, in August 2012. A second AMC system was installed at the third ARM Mobile Facility deployment at Oliktok Point, also known as NSA M1. This in situ system consists of 12 combination soil temperature and volumetric water content (VWC) reflectometers and one set of upwelling and downwelling photosynthetically active radiation (PAR) sensors, all deployed within the fetch of the Eddy Correlation Flux Measurement System. Soil temperature and VWC sensors placed at two depths (10 and 30 cm below the vegetation layer) at six locations (or microsites) allow soil property inhomogeneity to be monitored across a landscape.

  2. 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.

  3. Intelligent instruments for process measurement techniques (monitoring of sensors)

    Science.gov (United States)

    Bauer, B.; Hess, H. D.; Kalinski, J. R.; Leisenberg, W.; Marsch, D.

    1984-06-01

    Possibilities to extract redundant information of temperature sensors (resistance thermometers, thermocouples, semiconductor temperature sensors), and to find out which of the suggested redundancies are most suited for self controlled monitoring were investigated. Practical experience with equipment for process measurement techniques shows that sensor failures are five times more frequent than electronic malfunction. For resistance thermometers the measured values of the redundant information source (ac resistance) are too small (relative inductivity change 7 million). The information sources strain gage and propagation of ultrasonic waves are excluded because of physical properties in the sensor materials. Changes in the crystalline structure of thermocouples have the effect that there is no well defined relationship between thermoelectric voltage and the redundant information sources, resistance and coupled current impulses. A correlation of thermovoltage with these redundant values would yield a measurement uncertainty corresponding to more than + or - 50 K. Experiments with negative temperature coefficient sensors show that a failure is proceeded by a change in capacitance of the order of 0.1 pF.

  4. Using the refined ICF Linking Rules to compare the content of existing instruments and assessments: a systematic review and exemplary analysis of instruments measuring participation.

    Science.gov (United States)

    Ballert, Carolina S; Hopfe, Maren; Kus, Sandra; Mader, Luzius; Prodinger, Birgit

    2016-07-14

    Existing instruments measuring participation may vary with respect to various aspects. This study aimed to examine the comparability of existing instruments measuring participation based on the International Classification of Functioning, Disability and Health (ICF) by considering aspects of content, the perspective adopted and the categorization of response options. A systematic literature review was conducted to identify instruments that have been commonly used to measure participation. Concepts of identified instruments were then linked to the ICF following the refined ICF Linking Rules. Aspects of content, perspective adopted and categorization of response options were documented. Out of 315 instruments identified in the full-text screening, 41 instruments were included. Concepts of six instruments were linked entirely to the ICF component Activities and Participation; of 10 instruments still 80% of their concepts. A descriptive perspective was adopted in most items across instruments (75%), mostly in combination with an intensity rating. An appraisal perspective was found in 18% and questions from a need or dependency perspective were least frequent (7%). Accounting for aspects of content, perspective and categorization of responses in the linking of instruments to the ICF provides detailed information for the comparison of instruments and guidance on narrowing down the choices of suitable instruments from a content point of view. Implications for Rehabilitation For clinicians and researchers who need to identify a specific instrument for a given purpose, the findings of this review can serve as a screening tool for instruments measuring participation in terms of the following: • Their content covered based on the ICF. • The perspective adopted in the instrument (e.g., descriptive, need/dependency or appraisal). • The categorization of their response options (e.g., intensity or frequency).

  5. New acoustic system for continuous measurement of river discharge and water temperature

    Directory of Open Access Journals (Sweden)

    Kiyosi KAWANISI

    2010-03-01

    Full Text Available In many cases, river discharge is indirectly estimated from water level or streamflow velocity near the water surface. However, these methods have limited applicability. In this study, an innovative system, the fluvial acoustic tomography system (FATS, was used for continuous discharge measurement. Transducers with a central frequency of 30 kHz were installed diagonally across the river. The system’s significant functions include accurate measurement of the travel time of the transmission signal using a GPS clock and the attainment of a high signal-to-noise ratio as a result of modulation of the signal by the 10th order M-sequence. In addition, FATS is small and lightweight, and its power consumption is low. Operating in unsteady streamflow, FATS successfully measured the cross-sectional average velocity. The agreement between FATS and acoustic Doppler current profilers (ADCPs on water discharge was satisfactory. Moreover, the temporal variation of the cross-sectional average temperature deduced from the sound speed of FATS was similar to that measured by a temperature sensor near the bank.

  6. Examination of the Measurement of Absorption Using the Reverberant Room Method for Highly Absorptive Acoustic Foam

    Science.gov (United States)

    Hughes, William O.; McNelis, Anne M.; Chris Nottoli; Eric Wolfram

    2015-01-01

    The absorption coefficient for material specimens are needed to quantify the expected acoustic performance of that material in its actual usage and environment. The ASTM C423-09a standard, "Standard Test Method for Sound Absorption and Sound Absorption Coefficients by the Reverberant Room Method" is often used to measure the absorption coefficient of material test specimens. This method has its basics in the Sabine formula. Although widely used, the interpretation of these measurements are a topic of interest. For example, in certain cases the measured Sabine absorption coefficients are greater than 1.0 for highly absorptive materials. This is often attributed to the diffraction edge effect phenomenon. An investigative test program to measure the absorption properties of highly absorbent melamine foam has been performed at the Riverbank Acoustical Laboratories. This paper will present and discuss the test results relating to the effect of the test materials' surface area, thickness and edge sealing conditions. A follow-on paper is envisioned that will present and discuss the results relating to the spacing between multiple piece specimens, and the mounting condition of the test specimen.

  7. Digital PIV Measurements of Acoustic Particle Displacements in a Normal Incidence Impedance Tube

    Science.gov (United States)

    Humphreys, William M., Jr.; Bartram, Scott M.; Parrott, Tony L.; Jones, Michael G.

    1998-01-01

    Acoustic particle displacements and velocities inside a normal incidence impedance tube have been successfully measured for a variety of pure tone sound fields using Digital Particle Image Velocimetry (DPIV). The DPIV system utilized two 600-mj Nd:YAG lasers to generate a double-pulsed light sheet synchronized with the sound field and used to illuminate a portion of the oscillatory flow inside the tube. A high resolution (1320 x 1035 pixel), 8-bit camera was used to capture double-exposed images of 2.7-micron hollow silicon dioxide tracer particles inside the tube. Classical spatial autocorrelation analysis techniques were used to ascertain the acoustic particle displacements and associated velocities for various sound field intensities and frequencies. The results show that particle displacements spanning a range of 1-60 microns can be measured for incident sound pressure levels of 100-130 dB and for frequencies spanning 500-1000 Hz. The ability to resolve 1 micron particle displacements at sound pressure levels in the 100 dB range allows the use of DPIV systems for measurement of sound fields at much lower sound pressure levels than had been previously possible. Representative impedance tube data as well as an uncertainty analysis for the measurements are presented.

  8. 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.

  9. Heat release and flame structure measurements of self-excited acoustically-driven premixed methane flames

    Energy Technology Data Exchange (ETDEWEB)

    Kopp-Vaughan, Kristin M.; Tuttle, Steven G.; Renfro, Michael W. [Department of Mechanical Engineering, University of Connecticut, 191 Auditorium Rd, U-3139, Storrs, CT 06269 (United States); King, Galen B. [School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907 (United States)

    2009-10-15

    An open-open organ pipe burner (Rijke tube) with a bluff-body ring was used to create a self-excited, acoustically-driven, premixed methane-air conical flame, with equivalence ratios ranging from 0.85 to 1.05. The feed tube velocities corresponded to Re = 1780-4450. Coupled oscillations in pressure, velocity, and heat release from the flame are naturally encouraged at resonant frequencies in the Rijke tube combustor. This coupling creates sustainable self-excited oscillations in flame front area and shape. The period of the oscillations occur at the resonant frequency of the combustion chamber when the flame is placed {proportional_to}1/4 of the distance from the bottom of the tube. In this investigation, the shape of these acoustically-driven flames is measured by employing both OH planar laser-induced fluorescence (PLIF) and chemiluminescence imaging and the images are correlated to simultaneously measured pressure in the combustor. Past research on acoustically perturbed flames has focused on qualitative flame area and heat release relationships under imposed velocity perturbations at imposed frequencies. This study reports quantitative empirical fits with respect to pressure or phase angle in a self-generated pressure oscillation. The OH-PLIF images were single temporal shots and the chemiluminescence images were phase averaged on chip, such that 15 exposures were used to create one image. Thus, both measurements were time resolved during the flame oscillation. Phase-resolved area and heat release variations throughout the pressure oscillation were computed. A relation between flame area and the phase angle before the pressure maximum was derived for all flames in order to quantitatively show that the Rayleigh criterion was satisfied in the combustor. Qualitative trends in oscillating flame area were found with respect to feed tube flow rates. A logarithmic relation was found between the RMS pressure and both the normalized average area and heat release rate

  10. 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%.

  11. 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%.

  12. 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...

  13. 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)

  14. 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

  15. 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

  16. Validation of an Instrument to Measure Pharmacy and Medical Students’ Attitudes Toward Physician-Pharmacist Collaboration

    OpenAIRE

    Van Winkle, Lon J.; Fjortoft, Nancy; Hojat, Mohammadreza

    2011-01-01

    Objectives. To assess the validity and reliability of an instrument to measure pharmacy students’ attitudes toward physician-pharmacist collaboration, and compare those attitudes to the attitudes of medical students.

  17. 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...

  18. 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.

  19. Integrative Review of Instruments to Measure Team Performance During Neonatal Resuscitation Simulations in the Birthing Room.

    Science.gov (United States)

    Clary-Muronda, Valerie; Pope, Charlene

    2016-01-01

    To identify instruments appropriate to measure interprofessional team performance in neonatal resuscitation (NR), describe the validity and reliability of extant NR instruments, and determine instruments for use in interprofessional birthing room NR simulations. The Cumulative Index to Nursing and Allied Health Literature, Ovid MEDLINE, Proquest, ScienceDirect, PubMed, and Scopus databases were searched. We used inclusion and exclusion criteria and screened 641 abstracts from January 2000 through December 2014 for relevance to the research question. We reviewed 78 full-text primary research publications in English and excluded 37 publications not specific to pediatrics or neonatology. After in-depth review of the 41 studies that remained, we excluded additional studies if they did not have an interprofessional focus, include psychometric information, or include a measurement instrument. Ten publications met the inclusion criteria. Studies were reviewed, categorized, and scored to identify instruments to measure interprofessional team performance in simulations of birthing room NR. A social ecological model was used as a guide framework to identify multiple influencing factors at various levels that affect team performance. Ten instruments with documentation of validity and reliability for technical competence and team processes in interprofessional birthing room NR teams were identified. Extant instruments rarely address the multiple factors that may impede interprofessional team performance in birthing room NR. It is necessary for researchers to engage in rigorous psychometric testing of measurement instruments to ensure their validity and reliability for interprofessional NR teams and consider tests or updates (if necessary) of extant instruments rather than the development of new instruments. Copyright © 2016 AWHONN, the Association of Women’s Health, Obstetric and Neonatal Nurses. Published by Elsevier Inc. All rights reserved.

  20. 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.

  1. Design and Analyses of High Aspect Ratio Nozzles for Distributed Propulsion Acoustic Measurements

    Science.gov (United States)

    Dippold, Vance F., III

    2016-01-01

    A series of three convergent round-to-rectangular high-aspect ratio nozzles were designed for acoustics measurements. The nozzles have exit area aspect ratios of 8:1, 12:1, and 16:1. With septa inserts, these nozzles will mimic an array of distributed propulsion system nozzles, as found on hybrid wing-body aircraft concepts. Analyses were performed for the three nozzle designs and showed that the flow through the nozzles was free of separated flow and shocks. The exit flow was mostly uniform with the exception of a pair of vortices at each span-wise end of the nozzle.

  2. 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.

  3. 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.

  4. Magnetic hysteresis and magnetic flux patterns measured by acoustically stimulated electromagnetic response in a steel plate

    Science.gov (United States)

    Yamada, Hisato; Watanabe, Kakeru; Ikushima, Kenji

    2015-08-01

    Magnetic hysteresis loops are measured by ultrasonic techniques and used in visualizing the magnetic-flux distribution in a steel plate. The piezomagnetic coefficient determines the amplitude of acoustically stimulated electromagnetic (ASEM) fields, yielding the hysteresis behavior of the intensity of the ASEM response. By utilizing the high correspondence of the ASEM response to the magnetic-flux density, we image the specific spatial patterns of the flux density formed by an artificial defect in a steel plate specimen. Magnetic-flux probing by ultrasonic waves is thus shown to be a viable method of nondestructive material inspection.

  5. Training of Specialists in Information and Measurement Instrumentation in the Competence Discourse

    OpenAIRE

    Kvesko Svetlana; Shinn Tatyana

    2016-01-01

    Refocusing the assessment of the results of educational process from “qualifications” to the concepts of “competence” and “competency” is important in the context for the theoretical and methodological analysis of training in the sphere of information and measurement instrumentation and technologies. The purpose of this paper is to study of the training of today’s experts in the field of Information and Measurement Technologies and Instrumentation in the competence discourse. Based on the app...

  6. Specifying and calibrating instrumentations for wideband electronic power measurements. [in switching circuits

    Science.gov (United States)

    Lesco, D. J.; Weikle, D. H.

    1980-01-01

    The wideband electric power measurement related topics of electronic wattmeter calibration and specification are discussed. Tested calibration techniques are described in detail. Analytical methods used to determine the bandwidth requirements of instrumentation for switching circuit waveforms are presented and illustrated with examples from electric vehicle type applications. Analog multiplier wattmeters, digital wattmeters and calculating digital oscilloscopes are compared. The instrumentation characteristics which are critical to accurate wideband power measurement are described.

  7. Quantifying instrumentation background and measurement uncertainty through cross-domain coupling

    Science.gov (United States)

    Olson, D. K.; Larsen, B.; Weaver, B. P.

    2016-12-01

    Space physics measurement data are inherently riddled with background and noise signals that are difficult to separate from the desired true measurements. These issues become more vital to understand quantitatively as we make use of multiple instrumentation sets and satellite platforms. It is essential to develop a rigorous understanding of uncertainty in space measurements, particularly as spacecraft become more autonomous, in order to identify events of interest and predict the nominal behavior of space plasmas. We use data from the Van Allen Probes to demonstrate statistical techniques that can be applied to measurements of the HOPE and RPS instruments on the Van Allen Probes toward a solid and quantitative understanding of the true uncertainty of its measurements. This work provides a framework that predicts HOPE background measurements from the RPS foreground measurements and a definition of an event of interest from the HOPE instrumentation perspective.

  8. 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.

  9. 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....

  10. Design and development of a synthetic acoustic antenna for highly directional sound measurements

    Science.gov (United States)

    Boone, Rinus

    1987-12-01

    A SYNThetic ACoustic ANtenna (SYNTACAN) for highly directional sound measurements with an average resolving power of 1.5 deg in the frequency range from 89 to 1413 Hz (4 octave bands) with resolution of 1/12 octave, was developed for measurement of sound emissions from individual sources on industrial areas. The applicability of SYNTACAN is illustrated with a large number of test measurements concerning resolution, focussing, correlations, screening, and coherence loss. Measurements of sound from large factories, sound radiation from rotor blades of wind turbines, and the estimation of the source height of passing vehicles are described. Similarity between the imaging technique of SYNTACAN and techniques in optical and radioastronomy, sonar, radar, and seismology is discussed. The influence of the finite length of the antenna and the disturbance of the wave propagation by turbulence in the medium, causing finite beam patterns and thus unsharp source images is considered.

  11. Diffuse scattering measurements with synchrotron radiation: Instrumentation and techniques

    Energy Technology Data Exchange (ETDEWEB)

    Matsubara, E.; Georgopoulos, P.

    1985-12-01

    The analysis of diffuse scattering from single crystalline specimens in the reflection mode has generally been acknowledged as a very powerful means of obtaining structural information on local atomic arrangements in disordered alloys, intermetallics and ceramics. However, owing to the low intensities encountered and the large number of measurements required for such an analysis, experiments have been extremely time consuming and few have been attempted. Synchrotron radiation makes it possible to conduct such experiments in a matter of hours and much higher quality data can be obtained than in the laboratory. This paper describes the experimental procedures and methods applied to a study of Al-Cu age hardening alloys conducted at the Cornell Synchrotron Source (CHESS). (orig.).

  12. Potencials of sap flow evaluation by means of acoustic emission measurements

    Directory of Open Access Journals (Sweden)

    Michal Černý

    2011-01-01

    measurements became possible due to application of psychrometric method (Dixon and Tyree, 1985. There exist also other physical variables carrying important information, which can be measured using different principles. This includes e.g., acoustic methods, which can detect quantitative variation of pulses occurring during cavitation events, associated with interruptions of water columns in vessels. This must not necessarily be a single source of acoustic emissions. In this study we are focused on a general description of acoustic events measurable in a wide range of their spectrum. The first aim was to detect such signals and the second to learn them and gradually analyze in order to better understand the associated processes causing their occurrence and their relations to plant life.

  13. 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.

  14. INSTRUMENTAL MEASUREMENT OF KNEE LAXITY IN ANTERO-POSTERIOR DIRECTION

    Directory of Open Access Journals (Sweden)

    Miran Jeromel

    2004-11-01

    Full Text Available Background. A magnitude of clinical tests (like Lachman test are used to diagnose antero-posterior knee instability. They are easy to preform but they are very subjective. An experienced practitioner is often required. An alternative to standard clinical tests is the usage of arthrometer which requires a cooperative patient (maximal relaxation of thigh muscles.The aims of this study were to assess the antero-posterior laxity of both knees in the normal population (population without prior injury to the knee and to determine knee laxity in terms of total relaxation (usage of miorelaxant under general anaesthesia. We compared the difference between the left and right knee of the same individual and the influence of ageing and gender on knee laxity. We also studied the influences of diabetes and long-term corticosteroid therapy.We wanted to prove the following theories: complete relaxation of thigh muscles has an effect on measurement of knee laxity; the individual without prior knee injury has no statistically side to side difference; the laxity increases with age; women have grater ligamentous laxity than men; laxity increases as the result of diabetes and also as a result of longterm corticosteroid therapy.Methods. Arthrometer KT 1000/STM (Medmetric was used in our survey. We analysed 90 individuals (aged 18–81 who haven’t had knee injuries in the past.Among them were 45 (50% men and 45 (50% women. 8 (8.9% of them were diabetics and 4 (4.4% of them received long-term corticosteroid therapy.We assessed the antero-posterior laxity of both knees of an individual under the effect of general anaesthetic. Each measurement was repeated thrice. The same procedure was used to determinate antero-posterior laxity without the usage of anaesthetic.Results. We concluded that muscle relaxation affects the antero-posterior laxity of the knee (all the differences were statistically significant, p < 0.001. Side to side difference was minimal (statistically

  15. 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.

  16. Taking laser Doppler vibrometry off the tripod: correction of measurements affected by instrument vibration

    Science.gov (United States)

    Halkon, Ben J.; Rothberg, Steve J.

    2017-04-01

    Laser Doppler vibrometers (LDVs) are now well-established as an effective non-contact alternative to traditional contacting transducers. Despite 30 years of successful applications, however, very little attention has been given to sensitivity to vibration of the instrument itself. In this paper, the sensitivity to instrument vibration is confirmed before development theoretically and experimentally of a practical scheme to enable correction of measurements for arbitrary instrument vibration. The scheme requires a pair of correction sensors with appropriate orientation and relative location, while using frequency domain processing to accommodate inter-channel time delay and signal integrations. Error reductions in excess of 30 dB are delivered in laboratory tests with simultaneous instrument and target vibration over a broad frequency range. Ultimately, application to measurement on a vehicle simulator experiencing high levels of vibration demonstrates the practical nature of the correction technique and its robustness in a challenging measurement environment.

  17. Measuring teamwork in health care settings: a review of survey instruments.

    Science.gov (United States)

    Valentine, Melissa A; Nembhard, Ingrid M; Edmondson, Amy C

    2015-04-01

    Teamwork in health care settings is widely recognized as an important factor in providing high-quality patient care. However, the behaviors that comprise effective teamwork, the organizational factors that support teamwork, and the relationship between teamwork and patient outcomes remain empirical questions in need of rigorous study. To identify and review survey instruments used to assess dimensions of teamwork so as to facilitate high-quality research on this topic. We conducted a systematic review of articles published before September 2012 to identify survey instruments used to measure teamwork and to assess their conceptual content, psychometric validity, and relationships to outcomes of interest. We searched the ISI Web of Knowledge database, and identified relevant articles using the search terms team, teamwork, or collaboration in combination with survey, scale, measure, or questionnaire. We found 39 surveys that measured teamwork. Surveys assessed different dimensions of teamwork. The most commonly assessed dimensions were communication, coordination, and respect. Of the 39 surveys, 10 met all of the criteria for psychometric validity, and 14 showed significant relationships to nonself-report outcomes. Evidence of psychometric validity is lacking for many teamwork survey instruments. However, several psychometrically valid instruments are available. Researchers aiming to advance research on teamwork in health care should consider using or adapting one of these instruments before creating a new one. Because instruments vary considerably in the behavioral processes and emergent states of teamwork that they capture, researchers must carefully evaluate the conceptual consistency between instrument, research question, and context.

  18. Measuring Financial Literacy: Developing and Testing a Measurement Instrument with a Selected Group of South African Military Officers

    Science.gov (United States)

    Schwella, E.; van Nieuwenhuyzen, Bernard J.

    2014-01-01

    Are South Africans financially literate, and how can this be measured? Until 2009 there was no South African financial literacy measure and, therefore, the aim was to develop a South African measurement instrument that is scientific, socially acceptable, valid and reliable. To achieve this aim a contextual and conceptual analysis of financial…

  19. Measuring Financial Literacy: Developing and Testing a Measurement Instrument with a Selected Group of South African Military Officers

    Science.gov (United States)

    Schwella, E.; van Nieuwenhuyzen, Bernard J.

    2014-01-01

    Are South Africans financially literate, and how can this be measured? Until 2009 there was no South African financial literacy measure and, therefore, the aim was to develop a South African measurement instrument that is scientific, socially acceptable, valid and reliable. To achieve this aim a contextual and conceptual analysis of financial…

  20. [Instrumentation for blood pressure measurements: historical aspects, concepts and sources of error].

    Science.gov (United States)

    de Araujo, T L; Arcuri, E A; Martins, E

    1998-04-01

    According to the International Council of Nurses the measurement of blood pressure is the procedure most performed by nurses in all the world. The aim of this study is to analyse the polemical aspects of instruments used in blood pressure measurement. Considering the analyses of the literature and the American Heart Association Recommendations, the main source of errors when measuring blood pressure are discussed.