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Sample records for advanced ultrasonic techniques

  1. Advanced Ultrasonic Inspection Techniques for General Purpose Heat Source Fueled Clad Closure Welds

    SciTech Connect

    Moyer, M.W.

    2001-01-11

    A radioisotope thermoelectric generator is used to provide a power source for long-term deep space missions. This General Purpose Heat Source (GPHS) is fabricated using iridium clad vent sets to contain the plutonium oxide fuel pellets. Integrity of the closure weld is essential to ensure containment of the plutonium. The Oak Ridge Y-12 Plant took the lead role in developing the ultrasonic inspection for the closure weld and transferring the inspection to Los Alamos National Laboratory for use in fueled clad inspection for the Cassini mission. Initially only amplitude and time-of-flight data were recorded. However, a number of benign geometric conditions produced signals that were larger than the acceptance threshold. To identify these conditions, a B-scan inspection was developed that acquired full ultrasonic waveforms. Using a test protocol the B-scan inspection was able to identify benign conditions such as weld shield fusion and internal mismatch. Tangential radiography was used to confirm the ultrasonic results. All but two of 29 fueled clads for which ultrasonic B-scan data was evaluated appeared to have signals that could be attributed to benign geometric conditions. This report describes the ultrasonic inspection developed at Y-12 for the Cassini mission.

  2. Ultrasonic techniques for process monitoring and control.

    SciTech Connect

    Chien, H.-T.

    1999-03-24

    Ultrasonic techniques have been applied successfully to process monitoring and control for many industries, such as energy, medical, textile, oil, and material. It helps those industries in quality control, energy efficiency improving, waste reducing, and cost saving. This paper presents four ultrasonic systems, ultrasonic viscometer, on-loom, real-time ultrasonic imaging system, ultrasonic leak detection system, and ultrasonic solid concentration monitoring system, developed at Argonne National Laboratory in the past five years for various applications.

  3. Concepts and techniques for ultrasonic evaluation of material mechanical properties

    NASA Technical Reports Server (NTRS)

    Vary, A.

    1980-01-01

    Ultrasonic methods that can be used for material strength are reviewed. Emergency technology involving advanced ultrasonic techniques and associated measurements is described. It is shown that ultrasonic NDE is particularly useful in this area because it involves mechanical elastic waves that are strongly modulated by morphological factors that govern mechanical strength and also dynamic failure modes. These aspects of ultrasonic NDE are described in conjunction with advanced approaches and theoretical concepts for signal acquisition and analysis for materials characterization. It is emphasized that the technology is in its infancy and that much effort is still required before the techniques and concepts can be transferred from laboratory to field conditions.

  4. Composite Characterization Using Ultrasonic Wavefield Techniques

    NASA Technical Reports Server (NTRS)

    Leckey, Cara A. C.; Juarez, Peter D.; Seebo, Jeffrey P.

    2016-01-01

    The large-scale use of composite components in aerospace applications is expected to continue due to the benefits of composite materials, such as reduced weight, increased strength, and tailorability. NASA's Advanced Composites Project (ACP) has the goals of reducing the timeline for certification of composite materials and enabling the expanded use of advanced composite materials. A key technical challenge area for accomplishing these goals is the need for nondestructive evaluation and materials characterization techniques that are optimized for rapid inspection and detailed defect/damage characterization in composite materials. This presentation will discuss ongoing research investigating the use of ultrasonic wavefield techniques for the characterization of defects such as fiber waviness and delamination damage. Ongoing work includes the development of realistic ultrasonic simulation tools for use in predicting the inspectability of composites and optimizing inspection methodologies. Recent studies on detecting/characterizing delamination damage and fiber waviness via wavefield methods will be described.

  5. Ultrasonic and radiographic evaluation of advanced aerospace materials: Ceramic composites

    NASA Technical Reports Server (NTRS)

    Generazio, Edward R.

    1990-01-01

    Two conventional nondestructive evaluation techniques were used to evaluate advanced ceramic composite materials. It was shown that neither ultrasonic C-scan nor radiographic imaging can individually provide sufficient data for an accurate nondestructive evaluation. Both ultrasonic C-scan and conventional radiographic imaging are required for preliminary evaluation of these complex systems. The material variations that were identified by these two techniques are porosity, delaminations, bond quality between laminae, fiber alignment, fiber registration, fiber parallelism, and processing density flaws. The degree of bonding between fiber and matrix cannot be determined by either of these methods. An alternative ultrasonic technique, angular power spectrum scanning (APSS) is recommended for quantification of this interfacial bond.

  6. Ultrasonic imaging techniques for breast cancer detection.

    SciTech Connect

    Goulding, N. R.; Marquez, J. D.; Prewett, E. M.; Claytor, T. N.; Nadler, B. R.; Huang, L.

    2006-01-01

    Improving the resolution and specificity of current ultrasonic imaging technology can enhance its relevance to detection of early-stage breast cancers. Ultrasonic evaluation of breast lesions is desirable because it is quick, inexpensive, and does not expose the patient to potentially harmful ionizing radiation. Improved image quality and resolution enables earlier detection and more accurate diagnoses of tumors, thus reducing the number of biopsies performed, increasing treatment options, and lowering mortality, morbidity, and remission percentages. In this work, a novel ultrasonic imaging reconstruction method that exploits straight-ray migration is described. This technique, commonly used in seismic imaging, accounts for scattering more accurately than standard ultrasonic approaches, thus providing superior image resolution. A breast phantom with various inclusions is imaged using a pulse-echo approach. The data are processed using the ultrasonic migration method and results are compared to standard linear ultrasound and to x-ray computed tomography (CT) scans. For an ultrasonic frequency of 2.25 MHz, imaged inclusions and features of approximately 1mm are resolved, although better resolution is expected with minor modifications. Refinement of this application using other imaging techniques such as time-reversal mirrors (TRM), synthetic aperture focusing technique (SAFT), decomposition of the time reversal operator (DORT), and factorization methods is also briefly discussed.

  7. Ultrasonic non invasive techniques for microbiological instrumentation

    NASA Astrophysics Data System (ADS)

    Elvira, L.; Sierra, C.; Galán, B.; Resa, P.

    2010-01-01

    Non invasive techniques based on ultrasounds have advantageous features to study, characterize and monitor microbiological and enzymatic reactions. These processes may change the sound speed, viscosity or particle distribution size of the medium where they take place, which makes possible their analysis using ultrasonic techniques. In this work, two different systems for the analysis of microbiological liquid media based on ultrasounds are presented. In first place, an industrial application based on an ultrasonic monitoring technique for microbiological growth detection in milk is shown. Such a system may improve the quality control strategies in food production factories, being able to decrease the time required to detect possible contaminations in packed products. Secondly, a study about the growing of the Escherichia coli DH5 α in different conditions is presented. It is shown that the use of ultrasonic non invasive characterization techniques in combination with other conventional measurements like optical density provides complementary information about the metabolism of these bacteria.

  8. Ultrasonic techniques for aircraft ice accretion measurement

    NASA Technical Reports Server (NTRS)

    Hansman, R. John, Jr.; Kirby, Mark S.; Lichtenfelts, Fred

    1990-01-01

    Results of tests to measure ice growth in natural (flight) and artificial (icing wind tunnel) icing conditions are presented. Ice thickness is measured using an ultrasonic pulse-echo technique. Two icing regimes, wet and dry ice growth, are identified and the unique ultrasonic signal characteristics associated with these different types of ice growth are described. Ultrasonic measurements of ice growth on cylinders and airfoils exposed to artificial and natural icing conditions are presented. An accuracy of plus or minus 0.5 mm is achieved for ice thickness measurement using the pulse-echo technique. The performance of two-probe type ice detectors is compared to the surface mounted ultrasonic system. The ultrasonically measured ice accretion rates and ice surface condition (wet or dry) are used to compare the heat transfer characteristics for flight and icing wind tunnel environments. In general the heat transfer coefficient is inferred to be higher in the wind tunnel environment, not likely due to higher freestream turbulence levels. Finally, preliminary results of tests to measure ice growth on airfoil using an array of ultrasonic transducers are described. Ice profiles obtained during flight in natural icing conditions are shown and compared with mechanical and stereo image measurements.

  9. Advanced echocardiographic techniques

    PubMed Central

    Perry, Rebecca

    2015-01-01

    Abstract Echocardiography has advanced significantly since its first clinical use. The move towards more accurate imaging and quantification has driven this advancement. In this review, we will briefly focus on three distinct but important recent advances, three‐dimensional (3D) echocardiography, contrast echocardiography and myocardial tissue imaging. The basic principles of these techniques will be discussed as well as current and future clinical applications. PMID:28191159

  10. Recent modelling advances for ultrasonic TOFD inspections

    SciTech Connect

    Darmon, Michel; Ferrand, Adrien; Dorval, Vincent; Chatillon, Sylvain; Lonné, Sébastien

    2015-03-31

    The ultrasonic TOFD (Time of Flight Diffraction) Technique is commonly used to detect and characterize disoriented cracks using their edge diffraction echoes. An overview of the models integrated in the CIVA software platform and devoted to TOFD simulation is presented. CIVA allows to predict diffraction echoes from complex 3D flaws using a PTD (Physical Theory of Diffraction) based model. Other dedicated developments have been added to simulate lateral waves in 3D on planar entry surfaces and in 2D on irregular surfaces by a ray approach. Calibration echoes from Side Drilled Holes (SDHs), specimen echoes and shadowing effects from flaws can also been modelled. Some examples of theoretical validation of the models are presented. In addition, experimental validations have been performed both on planar blocks containing calibration holes and various notches and also on a specimen with an irregular entry surface and allow to draw conclusions on the validity of all the developed models.

  11. Recent modelling advances for ultrasonic TOFD inspections

    NASA Astrophysics Data System (ADS)

    Darmon, Michel; Ferrand, Adrien; Dorval, Vincent; Chatillon, Sylvain; Lonné, Sébastien

    2015-03-01

    The ultrasonic TOFD (Time of Flight Diffraction) Technique is commonly used to detect and characterize disoriented cracks using their edge diffraction echoes. An overview of the models integrated in the CIVA software platform and devoted to TOFD simulation is presented. CIVA allows to predict diffraction echoes from complex 3D flaws using a PTD (Physical Theory of Diffraction) based model. Other dedicated developments have been added to simulate lateral waves in 3D on planar entry surfaces and in 2D on irregular surfaces by a ray approach. Calibration echoes from Side Drilled Holes (SDHs), specimen echoes and shadowing effects from flaws can also been modelled. Some examples of theoretical validation of the models are presented. In addition, experimental validations have been performed both on planar blocks containing calibration holes and various notches and also on a specimen with an irregular entry surface and allow to draw conclusions on the validity of all the developed models.

  12. Erosive Burning Study Utilizing Ultrasonic Measurement Techniques

    NASA Technical Reports Server (NTRS)

    Furfaro, James A.

    2003-01-01

    A 6-segment subscale motor was developed to generate a range of internal environments from which multiple propellants could be characterized for erosive burning. The motor test bed was designed to provide a high Mach number, high mass flux environment. Propellant regression rates were monitored for each segment utilizing ultrasonic measurement techniques. These data were obtained for three propellants RSRM, ETM- 03, and Castor@ IVA, which span two propellant types, PBAN (polybutadiene acrylonitrile) and HTPB (hydroxyl terminated polybutadiene). The characterization of these propellants indicates a remarkably similar erosive burning response to the induced flow environment. Propellant burnrates for each type had a conventional response with respect to pressure up to a bulk flow velocity threshold. Each propellant, however, had a unique threshold at which it would experience an increase in observed propellant burn rate. Above the observed threshold each propellant again demonstrated a similar enhanced burn rate response corresponding to the local flow environment.

  13. Advanced ultrasonic measurement methodology for non-invasive interrogation and identification of fluids in sealed containers

    SciTech Connect

    Tucker, Brian J.; Diaz, Aaron A.; Eckenrode, Brian A.

    2006-05-01

    Government agencies and homeland security related organizations have identified the need to develop and establish a wide range of unprecedented capabilities for providing scientific and technical forensic services to investigations involving hazardous chemical, biological, and radiological materials, including extremely dangerous chemical and biological warfare agents. Pacific Northwest National Laboratory (PNNL) has developed a prototype portable, hand-held, hazardous materials acoustic inspection prototype that provides noninvasive container interrogation and material identification capabilities using nondestructive ultrasonic velocity and attenuation measurements. Due to the wide variety of fluids as well as container sizes and materials encountered in various law enforcement inspection activities, the need for high measurement sensitivity and advanced ultrasonic measurement techniques were identified. The prototype was developed using a versatile electronics platform, advanced ultrasonic wave propagation methods, and advanced signal processing techniques. This paper primarily focuses on the ultrasonic measurement methods and signal processing techniques incorporated into the prototype. High bandwidth ultrasonic transducers combined with an advanced pulse compression technique allowed researchers to 1) obtain high signal-to-noise ratios and 2) obtain accurate and consistent time-of-flight (TOF) measurements through a variety of highly attenuative containers and fluid media. Results of work conducted in the laboratory have demonstrated that the prototype experimental measurement technique also provided information regarding container properties, which will be utilized in future container-independent measurements of hidden liquids.

  14. Advanced ultrasonic measurement methodology for non-invasive interrogation and identification of fluids in sealed containers

    NASA Astrophysics Data System (ADS)

    Tucker, Brian J.; Diaz, Aaron A.; Eckenrode, Brian A.

    2006-03-01

    Government agencies and homeland security related organizations have identified the need to develop and establish a wide range of unprecedented capabilities for providing scientific and technical forensic services to investigations involving hazardous chemical, biological, and radiological materials, including extremely dangerous chemical and biological warfare agents. Pacific Northwest National Laboratory (PNNL) has developed a prototype portable, hand-held, hazardous materials acoustic inspection prototype that provides noninvasive container interrogation and material identification capabilities using nondestructive ultrasonic velocity and attenuation measurements. Due to the wide variety of fluids as well as container sizes and materials encountered in various law enforcement inspection activities, the need for high measurement sensitivity and advanced ultrasonic measurement techniques were identified. The prototype was developed using a versatile electronics platform, advanced ultrasonic wave propagation methods, and advanced signal processing techniques. This paper primarily focuses on the ultrasonic measurement methods and signal processing techniques incorporated into the prototype. High bandwidth ultrasonic transducers combined with an advanced pulse compression technique allowed researchers to 1) obtain high signal-to-noise ratios and 2) obtain accurate and consistent time-of-flight (TOF) measurements through a variety of highly attenuative containers and fluid media. Results of work conducted in the laboratory have demonstrated that the prototype experimental measurement technique also provided information regarding container properties, which will be utilized in future container-independent measurements of hidden liquids.

  15. Advanced Ultrasonic Measurement Methodology for Non-Invasive Interrogation and Identification of Fluids in Sealed Containers

    SciTech Connect

    Tucker, Brian J.; Diaz, Aaron A.; Eckenrode, Brian A.

    2006-03-16

    The Hazardous Materials Response Unit (HMRU) and the Counterterrorism and Forensic Science Research Unit (CTFSRU), Laboratory Division, Federal Bureau of Investigation (FBI) have been mandated to develop and establish a wide range of unprecedented capabilities for providing scientific and technical forensic services to investigations involving hazardous chemical, biological, and radiological materials, including extremely dangerous chemical and biological warfare agents. Pacific Northwest National Laboratory (PNNL) has developed a portable, hand-held, hazardous materials acoustic inspection device (HAZAID) that provides noninvasive container interrogation and material identification capabilities using nondestructive ultrasonic velocity and attenuation measurements. Due to the wide variety of fluids as well as container sizes and materials, the need for high measurement sensitivity and advanced ultrasonic measurement techniques were identified. The HAZAID prototype was developed using a versatile electronics platform, advanced ultrasonic wave propagation methods, and advanced signal processing techniques. This paper primarily focuses on the ultrasonic measurement methods and signal processing techniques incorporated into the HAZAID prototype. High bandwidth ultrasonic transducers combined with the advanced pulse compression technique allowed researchers to 1) impart large amounts of energy, 2) obtain high signal-to-noise ratios, and 3) obtain accurate and consistent time-of-flight (TOF) measurements through a variety of highly attenuative containers and fluid media. Results of this feasibility study demonstrated that the HAZAID experimental measurement technique also provided information regarding container properties, which will be utilized in future container-independent measurements of hidden liquids.

  16. Techniques for enhancing laser ultrasonic nondestructive evaluation

    SciTech Connect

    Candy, J; Chinn, D; Huber, R; Spicer, J; Thomas, G

    1999-02-16

    Ultrasonic nondestructive evaluation is an extremely powerful tool for characterizing materials and detecting defects. A majority of the ultrasonic nondestructive evaluation is performed with piezoelectric transducers that generate and detect high frequency acoustic energy. The liquid needed to couple the high frequency acoustic energy from the piezoelectric transducers restricts the applicability of ultrasonics. For example, traditional ultrasonics cannot evaluate parts at elevated temperatures or components that would be damaged by contact with a fluid. They are developing a technology that remotely generates and detects the ultrasonic pulses with lasers and consequently there is no requirement for liquids. Thus the research in laser-based ultrasound allows them to solve inspection problems with ultrasonics that could not be done before. This technology has wide application in many Lawrence Livermore National Laboratory programs, especially when remote and/or non-contact sensing is necessary.

  17. Helium-flow measurement using ultrasonic technique

    SciTech Connect

    Sondericker, J.H.

    1983-01-01

    While designing cryogenic instrumentation for the Colliding Beam Accelerator (CBA) helium-distribution system it became clear that accurate measurement of mass flow of helium which varied in temperature from room to sub-cooled conditions would be difficult. Conventional venturi flow meters full scale differential pressure signal would decrease by more than an order of magnitude during cooldown causing unacceptable error at operating temperature. At sub-cooled temperatures, helium would be pumped around cooling loops by an efficient, low head pressure circulating compressor. Additional pressure drop meant more pump work was necessary to compress the fluid resulting in a higher outlet temperature. The ideal mass flowmeter for this application was one which did not add pressure drop to the system, functioned over the entire temperature range, has high resolution and delivers accurate mass flow measurement data. Ultrasonic flow measurement techniques used successfully by the process industry, seemed to meet all the necessary requirements. An extensive search for a supplier of such a device found that none of the commercial stock flowmeters were adaptable to cryogenic service so the development of the instrument was undertaken by the CBA Cryogenic Control and Instrumentation Engineering Group at BNL.

  18. Advanced ultrasonic testing of complex shaped composite structures

    NASA Astrophysics Data System (ADS)

    Dolmatov, D.; Zhvyrblya, V.; Filippov, G.; Salchak, Y.; Sedanova, E.

    2016-06-01

    Due to the wide application of composite materials it is necessary to develop unconventional quality control techniques. One of the methods that can be used for this purpose is ultrasonic tomography. In this article an application of a robotic ultrasonic system is considered. Precise positioning of the robotic scanner and path generating are defined as ones of the most important aspects. This study proposes a non-contact calibration method of a robotic ultrasonic system. Path of the scanner requires a 3D model of controlled objects which are created in accordance with the proposed algorithm. The suggested techniques are based on implementation of structured light method.

  19. Ultrasonic Nondestructive Evaluation Techniques Applied to the Quantitative Characterization of Textile Composite Materials

    NASA Technical Reports Server (NTRS)

    Miller, James G.

    1998-01-01

    An overall goal of this research has been to enhance our understanding of the scientific principles necessary to develop advanced ultrasonic nondestructive techniques for the quantitative characterization of advanced composite structures. To this end, we have investigated a thin woven composite (5-harness biaxial weave). We have studied the effects that variations of the physical parameters of the experimental setup can have on the ultrasonic determination of the material properties for this thin composite. In particular, we have considered the variation of the nominal center frequency and the f-number of the transmitting transducer which in turn address issues such as focusing and beam spread of ultrasonic fields. This study has employed a planar, two-dimensional, receiving pseudo-array that has permitted investigation of the diffraction patterns of ultrasonic fields. Distortion of the ultrasonic field due to the spatial anisotropy of the thin composite has prompted investigation of the phenomenon of phase cancellation at the face of a finite-aperture, piezoelectric receiver. We have performed phase-sensitive and phase-insensitive analyses to provide a measure of the amount of phase cancellation at the face of a finite-aperture, piezoelectric receiver. The pursuit of robust measurements of received energy (i.e., those not susceptible to phase cancellation at the face of a finite-aperture, piezoelectric receiver) supports the development of robust techniques to determine material properties from measure ultrasonic parameters.

  20. Ultrasonic technique for characterizing skin burns

    DOEpatents

    Goans, Ronald E.; Cantrell, Jr., John H.; Meyers, F. Bradford; Stambaugh, Harry D.

    1978-01-01

    This invention, a method for ultrasonically determining the depth of a skin burn, is based on the finding that the acoustical impedance of burned tissue differs sufficiently from that of live tissue to permit ultrasonic detection of the interface between the burn and the underlying unburned tissue. The method is simple, rapid, and accurate. As compared with conventional practice, it provides the important advantage of permitting much earlier determination of whether a burn is of the first, second, or third degree. In the case of severe burns, the usual two - to three-week delay before surgery may be reduced to about 3 days or less.

  1. Introduction of measurement techniques in ultrasonic electronics: Basic principles and recent trends

    NASA Astrophysics Data System (ADS)

    Mizutani, Koichi; Wakatsuki, Naoto; Ebihara, Tadashi

    2016-07-01

    Measurement — the act of measuring physical properties that we perform — has the potential to contribute to the successful advancement of sciences and society. To open doors in physics and other sciences, various measurement methods and related applications have been developed, and ultrasound has remained a useful probe, power source, and interesting measurement object for the past two centuries. In this paper, we first summarize the basic principles of ultrasound from the viewpoint of measurement techniques for readers who just have started studying or are interested in the field of ultrasonic electronics. Moreover, we also introduce recent studies — ultrasonic properties of materials, measurement techniques, piezoelectric devices, nonlinear acoustics, biomedical ultrasound, and ocean acoustics — and their trends related to measurement techniques in ultrasonic electronics to provide some ideas for related applications.

  2. Benefits of the Multiple Echo Technique for Ultrasonic Thickness Testing

    SciTech Connect

    Elder, J.; Vandekamp, R.

    2011-02-10

    Much effort has been put into determining methods to make accurate thickness measurements, especially at elevated temperatures. An accuracy of +/- 0.001 inches is typically noted for commercial ultrasonic thickness gauges and ultrasonic thickness techniques. Codes and standards put limitations on many inspection factors including equipment, calibration tolerance and temperature variations. These factors are important and should be controlled, but unfortunately do not guarantee accurate and repeatable measurements in the field. Most technicians long for a single technique that is best for every situation, unfortunately, there are no 'silver bullets' when it comes to nondestructive testing. This paper will describe and discuss some of the major contributors to measurement error as well as some advantages and limitations of multiple echo techniques and why multiple echo techniques should be more widely utilized for ultrasonic thickness measurements.

  3. Elastic constant determination of hardwoods using ultrasonic insertion technique.

    PubMed

    Mat Daud, Anis Nazihah; Jaafar, Rosly; Ayop, Shahrul Kadri; Yaacob, Mohd Ikhwan Hadi; Rohani, Md Supar

    2017-03-01

    Ultrasonic insertion technique (IT) is an ultrasonic technique which involves sample immersion in a solution to determine its acoustic properties. IT is normally used to determine the acoustic properties of a medical phantom. We proposed the use of IT as an alternative technique to the common contact ultrasonic technique: through-transmission technique (TT) for determining the elastic constant of hardwoods in longitudinal, tangential and radial directions. The elastic constant of twelve rectangular-shaped Malaysian hardwoods from three different categories; heavy, medium and light with the density ranging from 602 to 992kgm(-3) were determined using IT and TT. Both techniques were carried out at 24.0°C surrounding temperature and utilized 2.25MHz ultrasonic transducers. Data from both techniques were compared to validate the use of the proposed technique. Findings indicated that IT offers consistent and accurate results for, tangential and radial elastic constants (TEC and REC) within 8.89% and 5.86% differences, respectively compared to TT for all tested hardwoods. IT offers an alternative technique for TEC and REC determinations of precious wood samples.

  4. High-power ultrasonic processing: Recent developments and prospective advances

    NASA Astrophysics Data System (ADS)

    Gallego-Juarez, Juan A.

    2010-01-01

    Although the application of ultrasonic energy to produce or to enhance a wide variety of processes have been explored since about the middle of the 20th century, only a reduced number of ultrasonic processes have been established at industrial level. However, during the last ten years the interest in ultrasonic processing has revived particularly in industrial sectors where the ultrasonic technology may represent a clean and efficient tool to improve classical existing processes or an innovation alternative for the development of new processes. Such seems to be the case of relevant sectors such as food industry, environment, pharmaceuticals and chemicals manufacture, machinery, mining, etc where power ultrasound is becoming an emerging technology for process development. The possible major problem in the application of high-intensity ultrasound on industrial processing is the design and development of efficient power ultrasonic systems (generators and reactors) capable of large scale successful operation specifically adapted to each individual process. In the area of ultrasonic processing in fluid media and more specifically in gases, the development of the steppedplate transducers and other power ge with extensive radiating surface has strongly contributed to the implementation at semi-industrial and industrial stage of several commercial applications, in sectors such as food and beverage industry (defoaming, drying, extraction, etc), environment (air cleaning, sludge filtration, etc...), machinery and process for manufacturing (textile washing, paint manufacture, etc). The development of different cavitational reactors for liquid treatment in continuous flow is helping to introduce into industry the wide potential of the area of sonochemistry. Processes such as water and effluent treatment, crystallization, soil remediation, etc have been already implemented at semi-industrial and/or industrial stage. Other single advances in sectors like mining or energy have

  5. Image measurement technique on vibration amplitude of ultrasonic horn

    NASA Astrophysics Data System (ADS)

    Zhang, Yong-bin; Wu, Zhi-qun; Zhu, Jian-ping; He, Jian-guo; Liu, Guang-min

    2013-10-01

    The paper proposes a method to measure vibration amplitude of ultrasonic horn which is a very important component in the spindle for micro-electrical-chemical discharging machining. The method of image measuring amplitude on high frequency vibration is introduced. Non-contact measurement system based on vision technology is constructed. High precision location algorithm on image centroid, quadratic location algorithm, is presented to find the center of little light spot. Measurement experiments have been done to show the effect of image measurement technique on vibration amplitude of ultrasonic horn. In the experiments, precise calibration of the vision system is implemented using a normal graticule to obtain the scale factor between image pixel and real distance. The vibration amplitude of ultrasonic horn is changed by modifying the voltage amplitude of pulse power supply. The image of feature on ultrasonic horn is captured and image processing is carried out. The vibration amplitudes are got at different voltages.

  6. Efficient imaging techniques using an ultrasonic array

    NASA Astrophysics Data System (ADS)

    Moreau, L.; Hunter, A. J.; Drinkwater, B. W.; Wilcox, P. D.

    2010-03-01

    Over the past few years, ultrasonic phased arrays have shown good potential for non-destructive testing (NDT), thanks to high resolution imaging algorithms that allow the characterization of defects in a structure. Many algorithms are based on the full matrix capture, obtained by firing each element of an ultrasonic array independently, while collecting the data with all elements. Because of the finite sound velocity in the specimen, two consecutive firings must be separated by a minimum time interval. Therefore, more elements in the array require longer data acquisition times. Moreover, if the array has N elements, then the full matrix contains N2 temporal signals to be processed. Because of the limited calculation speed of current computers, a large matrix of data can result in rather long post-processing times. In an industrial context where real-time imaging is desirable, it is crucial to reduce acquisition and/or post-processing times. This paper investigates methods designed to reduce acquisition and post-processing times for the TFM and wavenumber algorithms. To reduce data capture and post-processing, limited transmission cycles are used. Post-processing times is also further reduced by demodulating the data to baseband, which allows reducing the sampling rate of signals. Results are presented so that a compromise can be made between acquisition time, post-processing time and image quality. Possible improvement of images quality, using the effective aperture theory, is discussed. This has been implemented for the TFM but it still has to be developed for the wavenumber algorithm.

  7. A Simple Ultrasonic Experiment Using a Phase Shift Detection Technique.

    ERIC Educational Resources Information Center

    Yunus, W. Mahmood Mat; Ahmad, Maulana

    1996-01-01

    Describes a simple ultrasonic experiment that can be used to measure the purity of liquid samples by detecting variations in the velocity of sound. Uses a phase shift detection technique that incorporates the use of logic gates and a piezoelectric transducer. (JRH)

  8. A modified self-calibrating technique for an ultrasonic bridge

    NASA Astrophysics Data System (ADS)

    Komsky, I. N.; Achenbach, J. D.

    A second-generation ultrasonic bridge is presented for dry-contact self-calibrated measurements of wave velocities and amplitude changes over the gauge length of the ultrasonic bridge. The modified bridge and the modified self-calibrating technique are applied to the detection of radial edge cracks emanating from a countersunk rivet in a rivet joint of two aluminum plates. The transmission of ultrasound across the rivet joint for a sequence of placements of the bridge at increasing distances from the center of the rivet for ultrasound propagation parallel and normal to the crack direction is investigated. Waveforms for the propagation of ultrasound normal and parallel to the crack are shown.

  9. Double threshold ultrasonic distance measurement technique and its application

    NASA Astrophysics Data System (ADS)

    Li, Weihua; Chen, Qiang; Wu, Jiangtao

    2014-04-01

    The double threshold method realized by hardware circuits and high performance timing chip TDC-GP21 was successfully adapted to solve the key problem of ultrasonic distance measurement, the accurate time-of-flight (TOF) measurement of ultrasonic wave. Compared with other techniques of TOF measurement, the double threshold method presented in this work can suppress noise in the received signal, and achieve a time resolution of around 22 ps and real-time. This method is easy to realize and pertains the advantage of low cost. To compensate temperature and pressure deviations, a temperature measurement module of 10 mK in precision as well as a pressure measurement module of 0.01% in accuracy was developed. The system designed in this work can be exactly used as a two paths ultrasonic gas flowmeter without any adjustment of the hardware circuit. The double threshold method was further corroborated using experiment results of both the ultrasonic distance measurement and ultrasonic gas flow measurement. In distance measurement, the maximum absolute deviation and the maximum relative error are 0.69 mm and 0.28%, respectively, for a target distance range of 100-600 mm. In flow measurement, the maximum absolute deviation and the worst repeatability are 1.16% and 0.65% for a flow in the range of 50-700 m3/h.

  10. Double threshold ultrasonic distance measurement technique and its application.

    PubMed

    Li, Weihua; Chen, Qiang; Wu, Jiangtao

    2014-04-01

    The double threshold method realized by hardware circuits and high performance timing chip TDC-GP21 was successfully adapted to solve the key problem of ultrasonic distance measurement, the accurate time-of-flight (TOF) measurement of ultrasonic wave. Compared with other techniques of TOF measurement, the double threshold method presented in this work can suppress noise in the received signal, and achieve a time resolution of around 22 ps and real-time. This method is easy to realize and pertains the advantage of low cost. To compensate temperature and pressure deviations, a temperature measurement module of 10 mK in precision as well as a pressure measurement module of 0.01% in accuracy was developed. The system designed in this work can be exactly used as a two paths ultrasonic gas flowmeter without any adjustment of the hardware circuit. The double threshold method was further corroborated using experiment results of both the ultrasonic distance measurement and ultrasonic gas flow measurement. In distance measurement, the maximum absolute deviation and the maximum relative error are 0.69 mm and 0.28%, respectively, for a target distance range of 100-600 mm. In flow measurement, the maximum absolute deviation and the worst repeatability are 1.16% and 0.65% for a flow in the range of 50-700 m(3)/h.

  11. Remote measurement of corrosion using ultrasonic techniques

    SciTech Connect

    Garcia, K.M.; Porter, A.M.

    1995-02-01

    Supercritical water oxidation (SCWO) technology has the potential of meeting the US Department of Energy`s treatment requirements for mixed radioactive waste. A major technical constraint of the SCWO process is corrosion. Safe operation of a pilot plant requires monitoring of the corrosion rate of the materials of construction. A method is needed for measurement of the corrosion rate taking place during operation. One approach is to directly measure the change in wall thickness or growth of oxide layer at critical points in the SCWO process. In FY-93, a brief survey of the industry was performed to evaluate nondestructive evaluation (NDE) methods for remote corrosion monitoring in supercritical vessels. As a result of this survey, it was determined that ultrasonic testing (UT) methods would be the most cost-effective and suitable method of achieving this. Therefore, the objective for FY-94 was to prove the feasibility of using UT to monitor corrosion of supercritical vessels remotely during operation without removal of the insulation.

  12. Verification of Ultrasonic Image Fusion Technique for Laparoscopic Surgery

    NASA Astrophysics Data System (ADS)

    Zenbutsu, Satoki; Igarashi, Tatsuo; Mamou, Jonathan; Yamaguchi, Tadashi

    2012-07-01

    Laparoscopic surgery is one of the most challenging surgical operations, because inside information about the target organ cannot be fully understood from the laparoscopic image. Therefore, a fusion technique of laparoscopic and ultrasonic images is proposed for guidance during laparoscopic surgery. The proposed technique can display the internal organ structure by overlaying a three-dimensional (3D) ultrasonic image over a 3D laparoscopic image, which is acquired using a stereo laparoscope. The registration of the 3D images is performed by registering the surface of the target organ, which is found in the two 3D images without requiring the use of an external position detecting device. The proposed technique was evaluated experimentally using a tissue-mimicking phantom. Results obtained led to registration accuracy better than 2 cm. The total computation time was 3.1 min on a personal computer (Xeon processor, 3 GHz CPU). The structural information permits the visualization of target organs during laparoscopic surgery.

  13. Advanced defect detection algorithm using clustering in ultrasonic NDE

    NASA Astrophysics Data System (ADS)

    Gongzhang, Rui; Gachagan, Anthony

    2016-02-01

    A range of materials used in industry exhibit scattering properties which limits ultrasonic NDE. Many algorithms have been proposed to enhance defect detection ability, such as the well-known Split Spectrum Processing (SSP) technique. Scattering noise usually cannot be fully removed and the remaining noise can be easily confused with real feature signals, hence becoming artefacts during the image interpretation stage. This paper presents an advanced algorithm to further reduce the influence of artefacts remaining in A-scan data after processing using a conventional defect detection algorithm. The raw A-scan data can be acquired from either traditional single transducer or phased array configurations. The proposed algorithm uses the concept of unsupervised machine learning to cluster segmental defect signals from pre-processed A-scans into different classes. The distinction and similarity between each class and the ensemble of randomly selected noise segments can be observed by applying a classification algorithm. Each class will then be labelled as `legitimate reflector' or `artefacts' based on this observation and the expected probability of defection (PoD) and probability of false alarm (PFA) determined. To facilitate data collection and validate the proposed algorithm, a 5MHz linear array transducer is used to collect A-scans from both austenitic steel and Inconel samples. Each pulse-echo A-scan is pre-processed using SSP and the subsequent application of the proposed clustering algorithm has provided an additional reduction to PFA while maintaining PoD for both samples compared with SSP results alone.

  14. Advancement on Visualization Techniques

    DTIC Science & Technology

    1980-10-01

    Aeroa and As ronautics Massachusetts Institute of Technology Cambridge, MA 02139 USA I !ii 1 I This AGARDograph was prepared at the request of the...the fields of science § and technology relating to aerospace for the following purposes: - Exchanging of scientific and technical information...Techniques for providing the pilot visualization have grown rapidly. Technology has developed fron mechanical gauges through electro-mechanical

  15. Ultrasonic techniques for the detection of discontinuities in aluminum foams

    NASA Astrophysics Data System (ADS)

    Katchadjian, Pablo; García, Alejandro; Brizuela, Jose; Camacho, Jorge; Álvarez-Arenas, Tomás Gómez; Chiné, Bruno; Mussi, Valerio

    2017-02-01

    Metal foams are interesting materials with many potential applications. They are characterized by a cellular structure, that is the metals or metal alloys foamed include gas voids in the material. Their particular lightweight structure and physical, chemical and mechanical properties make them suitable for a wide range of industrial applications in different sectors. For industrial applications, metal foams offer attractive combinations of low density, high stiffness to weight ratio, good energy absorption and vibration damping capacity that cannot be obtained with other materials. The control of the foaming process and the characterization of the metal foam are important issues in order to obtain a product with good properties and guarantee the quality of a mechanical component. The characterization and control of mechanical components and sandwich panels manufactured with metal foams require the assessment of the defects present in this material, like large pores or imperfections which are responsible of deteriorating the mechanical performance. Therefore, specific methods of non-destructive testing are required, both in the manufacturing process and during the life of the component. In this work, some ultrasonic transmission techniques developed for detection of defects associated with the manufacturing process of aluminum foams are proposed. These techniques were used on plates and structures of different thicknesses and geometries formed with this material. Ultrasonic transmission techniques were carried out both, with low frequency air coupled transducers, and higher frequency transducers, focused and unfocused, by contact and immersion. To validate the results, the ultrasonic images obtained were compared with radiographic images of the foam.

  16. Advanced Coating Removal Techniques

    NASA Technical Reports Server (NTRS)

    Seibert, Jon

    2006-01-01

    An important step in the repair and protection against corrosion damage is the safe removal of the oxidation and protective coatings without further damaging the integrity of the substrate. Two such methods that are proving to be safe and effective in this task are liquid nitrogen and laser removal operations. Laser technology used for the removal of protective coatings is currently being researched and implemented in various areas of the aerospace industry. Delivering thousands of focused energy pulses, the laser ablates the coating surface by heating and dissolving the material applied to the substrate. The metal substrate will reflect the laser and redirect the energy to any remaining protective coating, thus preventing any collateral damage the substrate may suffer throughout the process. Liquid nitrogen jets are comparable to blasting with an ultra high-pressure water jet but without the residual liquid that requires collection and removal .As the liquid nitrogen reaches the surface it is transformed into gaseous nitrogen and reenters the atmosphere without any contamination to surrounding hardware. These innovative technologies simplify corrosion repair by eliminating hazardous chemicals and repetitive manual labor from the coating removal process. One very significant advantage is the reduction of particulate contamination exposure to personnel. With the removal of coatings adjacent to sensitive flight hardware, a benefit of each technique for the space program is that no contamination such as beads, water, or sanding residue is left behind when the job is finished. One primary concern is the safe removal of coatings from thin aluminum honeycomb face sheet. NASA recently conducted thermal testing on liquid nitrogen systems and found that no damage occurred on 1/6", aluminum substrates. Wright Patterson Air Force Base in conjunction with Boeing and NASA is currently testing the laser remOval technique for process qualification. Other applications of liquid

  17. Non-destructive evaluation of anchorage zones by ultrasonics techniques.

    PubMed

    Kharrat, M; Gaillet, L

    2015-08-01

    This work aims to evaluate the efficiency and reliability of two Non-Destructive Testing (NDT) methods for damage assessment in bridges' anchorages. The Acousto-Ultrasonic (AU) technique is compared to classical Ultrasonic Testing (UT) in terms of defect detection and structural health classification. The AU technique is firstly used on single seven-wire strands damaged by artificial defects. The effect of growing defects on the waves traveling through the strands is evaluated. Thereafter, three specimens of anchorages with unknown defects are inspected by the AU and UT techniques. Damage assessment results from both techniques are then compared. The structural health conditions of the specimens can be then classified by a damage severity criterion. Finally, a damaged anchorage socket with mastered defects is controlled by the same techniques. The UT allows the detection and localization of damaged wires. The AU technique is used to bring out the effect of defects on acoustic features by comparing a healthy and damaged anchorage sockets. It is concluded that the UT method is suitable for local and crack-like defects, whereas the AU technique enables the assessment of the global structural health of the anchorage zones.

  18. Advanced Wavefront Control Techniques

    SciTech Connect

    Olivier, S S; Brase, J M; Avicola, K; Thompson, C A; Kartz, M W; Winters, S; Hartley, R; Wihelmsen, J; Dowla, F V; Carrano, C J; Bauman, B J; Pennington, D M; Lande, D; Sawvel, R M; Silva, D A; Cooke, J B; Brown, C G

    2001-02-21

    this project, work was performed in four areas (1) advanced modeling tools for deformable mirrors (2) low-order wavefront correctors with Alvarez lenses, (3) a direct phase measuring heterdyne wavefront sensor, and (4) high-spatial-frequency wavefront control using spatial light modulators.

  19. Advanced qualification techniques

    SciTech Connect

    Winokur, P.S; Shaneyfelt, M.R.; Meisenheimer, T.L.; Fleetwood, D.M.

    1993-12-01

    This paper demonstrates use of the Qualified Manufacturers List (QML) methodology to qualify commercial and military microelectronics for use in space applications. QML ``builds in`` the hardness of product through statistical process control (SPC) of technology parameters relevant to the radiation response, test structure to integrated circuit (IC) correlations, and techniques for extrapolating laboratory test results to low-dose-rate space scenarios. Each of these elements is demonstrated and shown to be a cost-effective alternative to expensive end-of-line IC testing. Several examples of test structured-IC correlations are provided and recent work on complications arising from transistor scaling and geometry is discussed. The use of a 10-keV x-ray wafer-level test system to support SPC and establish ``process capability`` is illustrated and a comparison of 10-keV x-ray and Co{sup 60} gamma irradiations is provided for a wide range of CMOS technologies. The x-ray tester is shown to be cost-effective and its use in lot acceptance/qualification is recommended. Finally, a comparison is provided between MIL-STD-883D, Test Method 1019.4, which governs the testing of packaged semiconductor microcircuits in the DoD, and ESA/SSC Basic Specification No. 22900, Europe`s Total Dose Steady-State Irradiation Test Method. Test Method 1019.4 focuses on conservative estimates of MOS hardness for space and tactical applications, while Basic Specification 22900 focuses on improved simulation of low-dose-rate space environments.

  20. Ultrasonic Technique for Density Measurement of Liquids in Extreme Conditions

    PubMed Central

    Kazys, Rymantas; Sliteris, Reimondas; Rekuviene, Regina; Zukauskas, Egidijus; Mazeika, Liudas

    2015-01-01

    An ultrasonic technique, invariant to temperature changes, for a density measurement of different liquids under in situ extreme conditions is presented. The influence of geometry and material parameters of the measurement system (transducer, waveguide, matching layer) on measurement accuracy and reliability is analyzed theoretically along with experimental results. The proposed method is based on measurement of the amplitude of the ultrasonic wave, reflected from the interface of the solid/liquid medium under investigation. In order to enhance sensitivity, the use of a quarter wavelength acoustic matching layer is proposed. Therefore, the sensitivity of the measurement system increases significantly. Density measurements quite often must be performed in extreme conditions at high temperature (up to 220 °C) and high pressure. In this case, metal waveguides between piezoelectric transducer and the measured liquid are used in order to protect the conventional transducer from the influence of high temperature and to avoid depolarization. The presented ultrasonic density measurement technique is suitable for density measurement in different materials, including liquids and polymer melts in extreme conditions. A new calibration algorithm was proposed. The metrological evaluation of the measurement method was performed. The expanded measurement uncertainty Uρ = 7.4 × 10−3 g/cm3 (1%). PMID:26262619

  1. Analysis of ultrasonic techniques for monitoring milk coagulation during cheesemaking

    NASA Astrophysics Data System (ADS)

    Budelli, E.; Pérez, N.; Lema, P.; Negreira, C.

    2012-12-01

    Experimental determination of time of flight and attenuation has been proposed in the literature as alternatives to monitoring the evolution of milk coagulation during cheese manufacturing. However, only laboratory scale procedures have been described. In this work, the use of ultrasonic time of flight and attenuation to determine cutting time and its feasibility to be applied at industrial scale were analyzed. Limitations to implement these techniques at industrial scale are shown experimentally. The main limitation of the use of time of flight is its strong dependence with temperature. Attenuation monitoring is affected by a thin layer of milk skin covering the transducer, which modifies the signal in a non-repetitive way. The results of this work can be used to develop alternative ultrasonic systems suitable for application in the dairy industry.

  2. Fiber optic liquid leak detection technique with an ultrasonic actuator and a fiber Bragg grating.

    PubMed

    Lee, Jung-Ryul; Tsuda, Hiroshi

    2005-12-15

    We present a technique for liquid leak detection in which ultrasonic and optical waves are introduced into a fiber simultaneously. The system is based on an ultrasonic technique using an ultrasonic actuator and a fiber Bragg grating receiver. A fiber-guided ultrasonic wave is utilized to stress the fiber Bragg grating, which is remote from the ultrasonic transmitter. When the traveling ultrasonic wave encounters a liquid, part of the wave will leak out from the fiber, which results in an ultrasonic strain decrease in the fiber Bragg grating. The ultrasonic wave and its attenuation are detected by the light variation of a narrowband laser source reflected and transmitted from the fiber Bragg grating, and the amplitude variation of the ultrasound can eventually be correlated with the fiber area coupled with the liquid.

  3. Ultrasonic technique for extracting nanofibers from nature materials

    NASA Astrophysics Data System (ADS)

    Zhao, Hong-Ping; Feng, Xi-Qiao; Gao, Huajian

    2007-02-01

    This letter reports a simple and versatile approach for extracting bionanofibers from natural materials using the ultrasonic technique. Bionanofibers have been fabricated from various materials, e.g., spider and silkworm silks, chitin fibers, collagen, cotton, bamboo, and ramee and hemp fibers. The obtained nanofibers have uniform diameters in the range of 25-120nm and possess the optimized hierarchical structures and superior properties of natural materials which have formed after the evolution of many millions of years. This methodology might be valuable to provide a convenient, versatile, and environmentally benign fabrication method for producing bionanofibers at an industrial scale.

  4. Techniques in Advanced Language Teaching.

    ERIC Educational Resources Information Center

    Ager, D. E.

    1967-01-01

    For ease of presentation, advanced grammar teaching techniques are briefly considered under the headings of structuralism (belief in the effectiveness of presenting grammar rules) and contextualism (belief in the maximum use by students of what they know in the target language). The structuralist's problem of establishing a syllabus is discussed…

  5. Nondestructive evaluation/characterization of composite materials and structures using the acousto-ultrasonic techniques

    NASA Technical Reports Server (NTRS)

    Dos Reis, H. L. M.; Vary, A.

    1988-01-01

    This paper introduces the nature and the underlying rational of the acousto-ultrasonic stress wave factor technique and some of its applications to composite materials and structures. Furthermore, two examples of successful application of the acousto-ultrasonic technique are presented in detail. In the first example, the acousto-ultrasonic technique is used to evaluate the adhesive bond strength between rubber layers and steel plates, and in the seocnd example the tehcnique is used to monitor progressive damage in wire rope.

  6. Advanced reflector characterization with ultrasonic phased arrays in NDE applications.

    PubMed

    Wilcox, Paul D; Holmes, Caroline; Drinkwater, Bruce W

    2007-08-01

    Ultrasonic arrays are increasingly widely used in nondestructive evaluation (NDE) due to their greater flexibility and potentially superior performance compared to conventional monolithic probes. The characterization of small defects remains a challenge for NDE and is of great importance for determining the impact of a defect on the integrity of a structure. In this paper, a technique for characterizing reflectors with subwavelength dimensions is described. This is achieved by post-processing the complete data set of time traces obtained from an ultrasonic array using two algorithms. The first algorithm is used to obtain information about reflector orientation and the second algorithm is used to distinguish between point-like reflectors that reflect uniformly in all directions and specular reflectors that have distinct orientations. Experimental results are presented using a commercial 64-element, 5-MHZ array on two aluminum test specimens that contain a number of machined slots and side-drilled holes. The results show that the orientation of 1-mm-long slots can be determined to within a few degrees and that the signals from 1-mm-long slots can be distinguished from that from a 1-mm-diameter circular hole. Techniques for quantifying both the orientation and the specularity of measured signals are presented and the effect of processing parameters on the accuracy of results is discussed.

  7. Ultrasonic technique for monitoring of liquid density variations.

    PubMed

    Kazys, R; Rekuviene, R; Sliteris, R; Mazeika, L; Zukauskas, E

    2015-01-01

    A novel ultrasonic measurement technique for density measurements of different liquids in extreme conditions has been developed. The proposed density measurement method is based on transformation of the acoustic impedance of the measured liquid. The higher accuracy of measurements is achieved by means of the λ/4 acoustic matching layer between the load and the ultrasonic waveguide transducer. Introduction of the matching layer enhances sensitivity of the measurement system. Sometimes, the density measurements must be performed in very complex conditions: high temperature (up to 200 °C), pressure (up to 10 MPa), and high chemical activity of the medium under measurement. In this case, the special geometry metal waveguides are proposed to use in order to protect the piezoelectric transducer surface from influence of a high temperature. The experimental set-up of technique was calibrated using the reference liquids with different densities: ethyl ether, ethyl alcohol, distilled water, and different concentration (20%, 40%, and 60%) sugar-water solutions. The uncertainty of measurements is less than 1%. The proposed measurement method was verified in real conditions by monitoring the density of a melted polypropylene during manufacturing process.

  8. Residual stress characterization with an ultrasonic/magnetic technique

    NASA Technical Reports Server (NTRS)

    Namkung, M.; Heyman, J. S.

    1984-01-01

    A potentially useful new technique for residual stress characterization in ferromagnetic material is described. The unique feature of this technique is the measurement of small changes in ultrasonic wave velocity by the application of external dc magnetic field in the material under various stress conditions. It was found, in steel, that the fractional change in the natural velocity Delta W/W of waves propagating along the external field direction is affected by the uniaxial stress applied in the same axis. External compression lowers the slope of the Delta W/W curve in the low field region, while external tension generally does the opposite. For most cases, the slope in this region falls below zero under external compression. The result of measurements in specimens with residual stress shows exactly the same tendency.

  9. Advanced NDE techniques for quantitative characterization of aircraft

    NASA Technical Reports Server (NTRS)

    Heyman, Joseph S.; Winfree, William P.

    1990-01-01

    Recent advances in nondestructive evaluation (NDE) at NASA Langley Research Center and their applications that have resulted in quantitative assessment of material properties based on thermal and ultrasonic measurements are reviewed. Specific applications include ultrasonic determination of bolt tension, ultrasonic and thermal characterization of bonded layered structures, characterization of composite materials, and disbonds in aircraft skins.

  10. Nonlinear ultrasonic measurements based on cross-correlation filtering techniques

    NASA Astrophysics Data System (ADS)

    Yee, Andrew; Stewart, Dylan; Bunget, Gheorghe; Kramer, Patrick; Farinholt, Kevin; Friedersdorf, Fritz; Pepi, Marc; Ghoshal, Anindya

    2017-02-01

    Cyclic loading of mechanical components promotes the formation of dislocation dipoles in metals, which can serve as precursors to crack nucleation and ultimately lead to failure. In the laboratory setting, an acoustic nonlinearity parameter has been assessed as an effective indicator for characterizing the progression of fatigue damage precursors. However, the need to use monochromatic waves of medium-to-high acoustic energy has presented a constraint, making it problematic for use in field applications. This paper presents a potential approach for field measurement of acoustic nonlinearity by using general purpose ultrasonic pulser-receivers. Nonlinear ultrasonic measurements during fatigue testing were analyzed by the using contact and immersion pulse-through method. A novel cross-correlation filtering technique was developed to extract the fundamental and higher harmonic waves from the signals. As in the case of the classic harmonic generation, the nonlinearity parameters of the second and third harmonics indicate a strong correlation with fatigue cycles. Consideration was given to potential nonlinearities in the measurement system, and tests have confirmed that measured second harmonic signals exhibit a linear dependence on the input signal strength, further affirming the conclusion that this parameter relates to damage precursor formation from cyclic loading.

  11. Fast processing techniques for accurate ultrasonic range measurements

    NASA Astrophysics Data System (ADS)

    Barshan, Billur

    2000-01-01

    Four methods of range measurement for airborne ultrasonic systems - namely simple thresholding, curve-fitting, sliding-window, and correlation detection - are compared on the basis of bias error, standard deviation, total error, robustness to noise, and the difficulty/complexity of implementation. Whereas correlation detection is theoretically optimal, the other three methods can offer acceptable performance at much lower cost. Performances of all methods have been investigated as a function of target range, azimuth, and signal-to-noise ratio. Curve fitting, sliding window, and thresholding follow correlation detection in the order of decreasing complexity. Apart from correlation detection, minimum bias and total error is most consistently obtained with the curve-fitting method. On the other hand, the sliding-window method is always better than the thresholding and curve-fitting methods in terms of minimizing the standard deviation. The experimental results are in close agreement with the corresponding simulation results. Overall, the three simple and fast processing methods provide a variety of attractive compromises between measurement accuracy and system complexity. Although this paper concentrates on ultrasonic range measurement in air, the techniques described may also find application in underwater acoustics.

  12. Ultrasonic Techniques for Baseline-Free Damage Detection in Structures

    NASA Astrophysics Data System (ADS)

    Dutta, Debaditya

    This research presents ultrasonic techniques for baseline-free damage detection in structures in the context of structural health monitoring (SHM). Conventional SHM methods compare signals obtained from the pristine condition of a structure (baseline signals) with those from the current state, and relate certain changes in the signal characteristics to damage. While this approach has been successful in the laboratory, there are certain drawbacks of depending on baseline signals in real field applications. Data from the pristine condition are not available for most existing structures. Even if they are available, operational and environmental variations tend to mask the effect of damage on the signal characteristics. Most important, baseline measurements may become meaningless while assessing the condition of a structure after an extreme event such as an earthquake or a hurricane. Such events may destroy the sensors themselves and require installation of new sensors at different locations on the structure. Baseline-free structural damage detection can broaden the scope of SHM in the scenarios described above. A detailed discussion on the philosophy of baseline-free damage detection is provided in Chapter 1. Following this discussion, the research questions are formulated. The organization of this document and the major contributions of this research are also listed in this chapter. Chapter 2 describes a fully automated baseline-free technique for notch and crack detection in plates using a collocated pair of piezoelectric wafer transducers for measuring ultrasonic signals. Signal component corresponding to the damage induced mode-converted Lamb waves is extracted by processing the originally measured ultrasonic signals. The damage index is computed as a function of this mode-converted Lamb wave signal component. An over-determined system of Lamb wave measurements is used to find a least-square estimate of the measurement errors. This error estimate serves as the

  13. Capabilities of Ultrasonic Techniques for the Far-Side Examination of Austenitic Stainless Steel Piping Welds.

    SciTech Connect

    Anderson, Michael T.; Diaz, Aaron A.; Cumblidge, Stephen E.; Doctor, Steven R.

    2006-02-01

    A study was conducted to assess the ability of advanced ultrasonic techniques to detect and accurately determine the size of flaws from the far-side of wrought austenitic piping welds. Far-side inspections of nuclear system piping welds are currently performed on a “best effort” basis and do not conform to ASME Code Section XI Appendix VIII performance demonstration requirements. For this study, four circumferential welds in 610mm diameter, 36mm thick ASTM A-358, Grade 304 vintage austenitic stainless steel pipe were examined. The welds were fabricated with varied welding parameters; both horizontal and vertical pipe orientations were used, with air and water backing, to simulate field welding conditions. A series of saw cuts, electro-discharge machined (EDM) notches, and implanted fatigue cracks were placed into the heat affected zones of the welds. The saw cuts and notches ranged in depth from 7.5% to 28.4% through-wall. The implanted cracks ranged in depth from 5% through-wall to 64% through-wall. The welds were examined with phased array technology at 2.0 MHz, and with low-frequency/Synthetic Aperture Focusing Technique (SAFT) methods in the 250-400 kHz regime. These results were compared to conventional ultrasonic techniques as a baseline. The examinations showed that both phased-array and low-frequency/SAFT were able to detect and accurately length-size, but not depth size, the notches and flaws through the welds. The ultrasonic results were insensitive to the different welding techniques used in each weld.

  14. LHC Olympics: Advanced Analysis Techniques

    NASA Astrophysics Data System (ADS)

    Armour, Kyle; Larkoski, Andrew; Gray, Amanda; Ventura, Dan; Walsh, Jon; Schabinger, Rob

    2006-05-01

    The LHC Olympics is a series of workshop aimed at encouraging theorists and experimentalists to prepare for the soon-to-be-online Large Hadron Collider in Geneva, Switzerland. One aspect of the LHC Olympics program consists of the study of simulated data sets which represent various possible new physics signals as they would be seen in LHC detectors. Through this exercise, LHC Olympians learn the phenomenology of possible new physics models and gain experience in analyzing LHC data. Additionally, the LHC Olympics encourages discussion between theorists and experimentalists, and through this collaboration new techniques could be developed. The University of Washington LHC Olympics group consists of several first-year graduate and senior undergraduate students, in both theoretical and experimental particle physics. Presented here is a discussion of some of the more advanced techniques used and the recent results of one such LHC Olympics study.

  15. Ultrasonic velocity technique for monitoring property changes in fiber-reinforced ceramic matrix composites

    NASA Technical Reports Server (NTRS)

    Kautz, Harold E.; Bhatt, Ramakrishna T.

    1991-01-01

    A technique for measuring ultrasonic velocity was used to monitor changes that occur during processing and heat treatment of a SiC/RBSM composite. Results indicated that correlations exist between the ultrasonic velocity data and elastic modulus and interfacial shear strength data determined from mechanical tests. The ultrasonic velocity data can differentiate strength. The advantages and potential of this nondestructive evaluation method for fiber reinforced ceramic matrix composite applications are discussed.

  16. System and technique for ultrasonic determination of degree of cooking

    DOEpatents

    Bond, Leonard J.; Diaz, Aaron A.; Judd, Kayte M.; Pappas, Richard A.; Cliff, William C.; Pfund, David M.; Morgen, Gerald P.

    2007-03-20

    A method and apparatus are described for determining the doneness of food during a cooking process. Ultrasonic signal are passed through the food during cooking. The change in transmission characteristics of the ultrasonic signal during the cooking process is measured to determine the point at which the food has been cooked to the proper level. In one aspect, a heated fluid cooks the food, and the transmission characteristics along a fluid-only ultrasonic path provides a reference for comparison with the transmission characteristics for a food-fluid ultrasonic path.

  17. Capabilities of Ultrasonic Techniques for Far-Side Examinations of Austenitic Stainless Steel Piping Welds.

    SciTech Connect

    Anderson, Michael T.; Diaz, Aaron A.; Cumblidge, Stephen E.; Doctor, Steven R.

    2007-01-01

    A study was conducted to assess the ability of advanced ultrasonic techniques to detect and accurately length-size flaws from the far-side of wrought austenitic piping welds. Far-side inspections of nuclear system piping welds are currently performed on a “best effort” basis and do not conform to ASME Code Section XI Appendix VIII performance demonstration requirements. For this study, austenitic stainless steel specimens with flaws located on the far-side of full penetration structural welds were used. The welds were fabricated with varied welding parameters to simulate as-built conditions in the components, and were examined with phased array technology at 2.0 MHz, and low-frequency/Synthetic Aperture Focusing Technique (SAFT) methods in the 250-400 kHz regime. These results were compared to conventional ultrasonic techniques as a baseline. The examinations showed that both phased-array and low-frequency/SAFT were able to reliably detect and length-size, but not depth size, notches and implanted fatigue cracks through the welds.

  18. Ultrasonic Testing, Aviation Quality Control (Advanced): 9227.03.

    ERIC Educational Resources Information Center

    Dade County Public Schools, Miami, FL.

    This unit of instruction covers the theory of ultrasonic sound, methods of applying soundwaves to test specimens and interpreting results, calibrating the ultrasonic equipment, and the use of standards. Study periods, group discussions, and extensive use of textbooks and training manuals are to be used. These are listed along with references and…

  19. Compressed Sensing Techniques Applied to Ultrasonic Imaging of Cargo Containers.

    PubMed

    López, Yuri Álvarez; Lorenzo, José Ángel Martínez

    2017-01-15

    One of the key issues in the fight against the smuggling of goods has been the development of scanners for cargo inspection. X-ray-based radiographic system scanners are the most developed sensing modality. However, they are costly and use bulky sources that emit hazardous, ionizing radiation. Aiming to improve the probability of threat detection, an ultrasonic-based technique, capable of detecting the footprint of metallic containers or compartments concealed within the metallic structure of the inspected cargo, has been proposed. The system consists of an array of acoustic transceivers that is attached to the metallic structure-under-inspection, creating a guided acoustic Lamb wave. Reflections due to discontinuities are detected in the images, provided by an imaging algorithm. Taking into consideration that the majority of those images are sparse, this contribution analyzes the application of Compressed Sensing (CS) techniques in order to reduce the amount of measurements needed, thus achieving faster scanning, without compromising the detection capabilities of the system. A parametric study of the image quality, as a function of the samples needed in spatial and frequency domains, is presented, as well as the dependence on the sampling pattern. For this purpose, realistic cargo inspection scenarios have been simulated.

  20. Compressed Sensing Techniques Applied to Ultrasonic Imaging of Cargo Containers

    PubMed Central

    Álvarez López, Yuri; Martínez Lorenzo, José Ángel

    2017-01-01

    One of the key issues in the fight against the smuggling of goods has been the development of scanners for cargo inspection. X-ray-based radiographic system scanners are the most developed sensing modality. However, they are costly and use bulky sources that emit hazardous, ionizing radiation. Aiming to improve the probability of threat detection, an ultrasonic-based technique, capable of detecting the footprint of metallic containers or compartments concealed within the metallic structure of the inspected cargo, has been proposed. The system consists of an array of acoustic transceivers that is attached to the metallic structure-under-inspection, creating a guided acoustic Lamb wave. Reflections due to discontinuities are detected in the images, provided by an imaging algorithm. Taking into consideration that the majority of those images are sparse, this contribution analyzes the application of Compressed Sensing (CS) techniques in order to reduce the amount of measurements needed, thus achieving faster scanning, without compromising the detection capabilities of the system. A parametric study of the image quality, as a function of the samples needed in spatial and frequency domains, is presented, as well as the dependence on the sampling pattern. For this purpose, realistic cargo inspection scenarios have been simulated. PMID:28098841

  1. Determination of avocado and mango fruit properties by ultrasonic technique.

    PubMed

    Mizrach, A

    2000-03-01

    A nondestructive ultrasonic measurement system was developed for the assessment of some transmission parameters which might have quantitative relations with the maturity, firmness and other quality-related properties of avocado and mango fruits. The system utilizes a set of low-frequency probes arranged to measure the ultrasonic signal transmitted and received over a short distance across the peel. The attenuation of the ultrasonic waves, transmitted through the peel and the attached fruit tissue, changes as a result of the progressive ripening and softening of the fruit during the fruiting season and in the course of storage. The present study quantitatively addressed the linkage between the ultrasonic attenuation and the physiological parameters of the flesh of the fruits. Results were obtained in the time and frequency domain, and the data set was analyzed statistically to identify the relations between the major physiological indices and the ultrasonic parameters. Quantitative relations were developed to describe the linkage between ultrasonic parameters and the maturity, firmness and other quality-related properties in mango and avocado fruits.

  2. Assessment of Crack Detection in Cast Austenitic Piping Components Using Advanced Ultrasonic Methods.

    SciTech Connect

    Anderson, Michael T.; Crawford, Susan L.; Cumblidge, Stephen E.; Diaz, Aaron A.; Doctor, Steven R.

    2007-01-01

    Studies conducted at the Pacific N¬orthwest National Laboratory (PNNL) in Richland, Washington, have focused on developing and evaluating the reliability of nondestructive examination (NDE) approaches for inspecting coarse-grained, cast stainless steel reactor components. The objective of this work is to provide information to the United States Nuclear Regulatory Commission (NRC) on the utility, effec¬tiveness and limitations of ultrasonic testing (UT) inspection techniques as related to the in-service inspec¬tion of primary system piping components in pressurized water reactors (PWRs). Cast stainless steel pipe specimens were examined that contain thermal and mechanical fatigue cracks located close to the weld roots and have inside/outside surface geometrical conditions that simulate several PWR primary piping configurations. In addition, segments of vintage centrifugally cast piping were also examined to understand inherent acoustic noise and scattering due to grain structures and determine consistency of UT responses from different locations. The advanced UT methods were applied from the outside surface of these specimens using automated scanning devices and water coupling. The low-frequency ultrasonic method employed a zone-focused, multi-incident angle inspection protocol (operating at 250-450 kHz) coupled with a synthetic aperture focusing technique (SAFT) for improved signal-to-noise and advanced imaging capabilities. The phased array approach was implemented with a modified instrument operating at 500 kHz and composite volumetric images of the specimens were generated. Re¬sults from laboratory studies for assessing detection, localization and sizing effectiveness are discussed in this paper.

  3. Passive focusing techniques for piezoelectric air-coupled ultrasonic transducers.

    PubMed

    Gómez Álvarez-Arenas, Tomás E; Camacho, Jorge; Fritsch, Carlos

    2016-04-01

    This paper proposes a novel passive focusing system for Air-Coupled Ultrasonic (ACU) piezoelectric transducers which is inspired by the Newtonian-Cassegrain (NC) telescope concept. It consist of a primary spherical mirror with an output hole and a flat secondary mirror, normal to the propagation axis, that is the transducer surface itself. The device is modeled and acoustic field is calculated showing a collimated beam with a symmetrical focus. A prototype according to this design is built and tested with an ACU piezoelectric transducer with center frequency at 400 kHz, high-sensitivity, wideband and 25 mm diameter flat aperture. The acoustic field is measured and compared with calculations. The presented prototype exhibit a 1.5 mm focus width and a collimated beam up to 15 mm off the output hole. In addition, the performance of this novel design is compared, both theoretically and experimentally, with two techniques used before for electrostatic transducers: the Fresnel Zone Plate - FZP and the off-axis parabolic or spherical mirror. The proposed NC arrangement has a coaxial design, which eases the transducers positioning and use in many applications, and is less bulky than off-axis mirrors. Unlike in off-axis mirrors, it is now possible to use a spherical primary mirror with minimum aberrations. FZP provides a more compact solution and is easy to build, but presents some background noise due to interference of waves diffracted at out of focus regions. By contrast, off-axis parabolic mirrors provide a well defined focus and are free from background noise, although they are bulky and more difficult to build. Spherical mirrors are more easily built, but this yields a non symmetric beam and a poorly defined focus.

  4. Advanced techniques for microwave reflectometry

    SciTech Connect

    Sanchez, J.; Branas, B.; Luna, E. de la; Estrada, T.; Zhuravlev, V. |; Hartfuss, H.J.; Hirsch, M.; Geist, T.; Segovia, J.; Oramas, J.L.

    1994-12-31

    Microwave reflectometry has been applied during the last years as a plasma diagnostic of increasing interest, mainly due to its simplicity, no need for large access ports and low radiation damage of exposed components. Those characteristics make reflectometry an attractive diagnostic for the next generation devices. Systems used either for density profile or density fluctuations have also shown great development, from the original single channel heterodyne to the multichannel homodyne receivers. In the present work we discuss three different advanced reflectometer systems developed by CIEMAT members in collaboration with different institutions. The first one is the broadband heterodyne reflectometer installed on W7AS for density fluctuations measurements. The decoupling of the phase and amplitude of the reflected beam allows for quantitative analysis of the fluctuations. Recent results showing the behavior of the density turbulence during the L-H transition on W7AS are shown. The second system shows how the effect of the turbulence can be used for density profile measurements by reflectometry in situations where the complicated geometry of the waveguides cannot avoid many parasitic reflections. Experiments from the TJ-I tokamak will be shown. Finally, a reflectometer system based on the Amplitude Modulation (AM) technique for density profile measurements is discussed and experimental results from the TJ-I tokamak are shown. The AM system offers the advantage of being almost insensitive to the effect of fluctuations. It is able to take a direct measurement of the time delay of the microwave pulse which propagates to the reflecting layer and is reflected back. In order to achieve fast reconstruction for real time monitoring of the density profile application of Neural Networks algorithms will be presented the method can reduce the computing times by about three orders of magnitude. 10 refs., 10 figs.

  5. Advances in Procedural Techniques - Antegrade

    PubMed Central

    Wilson, William; Spratt, James C.

    2014-01-01

    There have been many technological advances in antegrade CTO PCI, but perhaps most importantly has been the evolution of the “hybrid’ approach where ideally there exists a seamless interplay of antegrade wiring, antegrade dissection re-entry and retrograde approaches as dictated by procedural factors. Antegrade wire escalation with intimal tracking remains the preferred initial strategy in short CTOs without proximal cap ambiguity. More complex CTOs, however, usually require either a retrograde or an antegrade dissection re-entry approach, or both. Antegrade dissection re-entry is well suited to long occlusions where there is a healthy distal vessel and limited “interventional” collaterals. Early use of a dissection re-entry strategy will increase success rates, reduce complications, and minimise radiation exposure, contrast use as well as procedural times. Antegrade dissection can be achieved with a knuckle wire technique or the CrossBoss catheter whilst re-entry will be achieved in the most reproducible and reliable fashion by the Stingray balloon/wire. It should be avoided where there is potential for loss of large side branches. It remains to be seen whether use of newer dissection re-entry strategies will be associated with lower restenosis rates compared with the more uncontrolled subintimal tracking strategies such as STAR and whether stent insertion in the subintimal space is associated with higher rates of late stent malapposition and stent thrombosis. It is to be hoped that the algorithms, which have been developed to guide CTO operators, allow for a better transfer of knowledge and skills to increase uptake and acceptance of CTO PCI as a whole. PMID:24694104

  6. Characterization of hydrogen concentration in Zircaloy-4 using ultrasonic techniques

    NASA Astrophysics Data System (ADS)

    Gómez, M. P.; Domizzi, G.; Pumarega, M. I. López; Ruzzante, J. E.

    2006-07-01

    The relationship between hydrogen concentration precipitated as hydride particles and ultrasonic parameters, such as velocity and attenuation, was examined in Zircaloy-4 samples for potential applications in the Non-Destructive Test Field. Different amounts of hydrogen (up to 517 ppm) were introduced in the samples by gaseous charging. Ultrasonic attenuation measurements were performed with compressive waves at frequencies of 10 and 30 MHz, and propagation velocity measurements were performed at 10 MHz. Ultrasonic velocity showed an approximately linear increase with hydrogen concentration and it could be used as an assessment parameter when the hydrogen level is high enough. Attenuation versus hydrogen concentration has been fitted by a logarithmic equation at 10 MHz. At 30 MHz a fluctuating behavior of the attenuation prevented measurement of the hydrogen concentration.

  7. Ultrasonics

    NASA Technical Reports Server (NTRS)

    Leonard, B. E.; Gardner, C. G.

    1973-01-01

    Ultrasonic testing is discussed as a primary means of nondestructive evaluation of subsurface flaws. The advantages and disadvantages are listed. The elementary principles, basic components of test units, scan modes, resonance testing, detection of fatigue cracks, monitoring fatigue crack growth, and determination of residual stress are discussed.

  8. Bruce Thompson: Adventures and advances in ultrasonic backscatter

    NASA Astrophysics Data System (ADS)

    Margetan, Frank J.

    2012-05-01

    Over the course of his professional career Dr. R. Bruce Thompson published several hundred articles on non-destructive evaluation, the majority dealing with topics in ultrasonics. One longtime research interest of Dr. Thompson, with applications both to microstructure characterization and defect detection, was backscattered grain noise in metals. Over a 20 year period he led a revolving team of staff members and graduate students investigating various aspects of ultrasonic backscatter. As a member of that team I had the privilege of working along side Dr. Thompson for many years, serving as a sort of Dr. Watson to Bruce's Sherlock Holmes. This article discusses Dr. Thompson's general approaches to modeling backscatter, the research topics he chose to explore to systematically elucidate a better understanding of the phenomena, and the many contributions to the field achieved under his leadership. The backscatter work began in earnest around 1990, motivated by a need to improve inspections of aircraft engine components. At that time Dr. Thompson launched two research efforts. The first led to the heuristic Independent Scatterer Model which could be used to estimate the average grain noise level that would be seen in any given ultrasonic inspection. There the contribution from the microstructure was contained in a measureable parameter known as the Figure-of-Merit or FOM. The second research effort, spearheaded by Dr. Jim Rose, led to a formal relationship between FOM and details of the metal microstructure. The combination of the Independent Scattering Model and Rose's formalism provided a powerful tool for investigating backscatter in metals. In this article model developments are briefly reviewed and several illustrative applications are discussed. These include: the determination of grain size and shape from ultrasonic backscatter; grain noise variability in engine-titanium billets and forgings; and the design of ultrasonic inspection systems to improve defect

  9. Applications of the Ultrasonic Serial Number Restoration Technique to Guns and Typical Stolen Articles

    NASA Technical Reports Server (NTRS)

    Young, S. G.

    1976-01-01

    An ultrasonic cavitation method for restoring obliterated serial numbers has been further explored by application to articles involved in police cases. The method was applied successfully to gun parts. In one case portions of numbers were restored after prior failure by other laboratories using chemical etching techniques. The ultrasonic method was not successful on a heavily obliterated and restamped automobile engine block, but it was partially successful on a motorcycle gear-case housing. Additional studies were made on the effect of a larger diameter ultrasonic probe, and on the method's ability to restore numbers obliterated by peening.

  10. Epoxy Thermosets: The Detection of Adverse Stoichiometry Using Ultrasonic, Dielectric and NMR Techniques

    NASA Astrophysics Data System (ADS)

    Unwin, M. E.; Challis, R. E.

    2004-02-01

    The relative proportions of hardener and resin (the stoichiometric ratio, SR) in a curing epoxy thermoset strongly influence the engineering properties of the material. We investigate how NMR, dielectric and ultrasonic techniques can be used to track cure and estimate SR in the material. We show that all three methods are sensitive to SR and can give clear and quantitative indications of excess resin. Detection of excess hardener in the finally cured material is more difficult but can be achieved by combined measures of elastic modulus, from the ultrasonic velocity, and loss angle, from ultrasonic attenuation.

  11. Application of Ultrasonic Techniques for Brain Injury Diagnosis

    SciTech Connect

    Kasili, P.M.; Mobley, J.; Norton, S.J.; Vo-Dinh, T.

    1999-09-19

    In this work, we evaluate methods for detecting brain injury using ultrasound. We have used simulations of ultrasonic fields in the head to model the phase distortion of the skull. In addition we present experimental data from the crania of large animals. The experimental data help us understand and evaluate the performance of different transducers in acquiring the backscatter data from the brain through the skull. Both the simulations and acquired data illustrate the superiority of lower-frequency (<= 1 MHz) ultrasonic fields for transcranial acquisition of signals from inside the brain. Additionally, the experimental work shows that the higher-frequency (5 MHz) ultrasound can also be useful in acquiring clean nearfield data to help detect the position of the inner boundary of the skull.

  12. Application of wavelet packet entropy flow manifold learning in bearing factory inspection using the ultrasonic technique.

    PubMed

    Chen, Xiaoguang; Liu, Dan; Xu, Guanghua; Jiang, Kuosheng; Liang, Lin

    2014-12-26

    For decades, bearing factory quality evaluation has been a key problem and the methods used are always static tests. This paper investigates the use of piezoelectric ultrasonic transducers (PUT) as dynamic diagnostic tools and a relevant signal classification technique, wavelet packet entropy (WPEntropy) flow manifold learning, for the evaluation of bearing factory quality. The data were analyzed using wavelet packet entropy (WPEntropy) flow manifold learning. The results showed that the ultrasonic technique with WPEntropy flow manifold learning was able to detect different types of defects on the bearing components. The test method and the proposed technique are described and the different signals are analyzed and discussed.

  13. Application of Wavelet Packet Entropy Flow Manifold Learning in Bearing Factory Inspection Using the Ultrasonic Technique

    PubMed Central

    Chen, Xiaoguang; Liu, Dan; Xu, Guanghua; Jiang, Kuosheng; Liang, Lin

    2015-01-01

    For decades, bearing factory quality evaluation has been a key problem and the methods used are always static tests. This paper investigates the use of piezoelectric ultrasonic transducers (PUT) as dynamic diagnostic tools and a relevant signal classification technique, wavelet packet entropy (WPEntropy) flow manifold learning, for the evaluation of bearing factory quality. The data were analyzed using wavelet packet entropy (WPEntropy) flow manifold learning. The results showed that the ultrasonic technique with WPEntropy flow manifold learning was able to detect different types of defects on the bearing components. The test method and the proposed technique are described and the different signals are analyzed and discussed. PMID:25549173

  14. DPSM technique for ultrasonic field modelling near fluid-solid interface.

    PubMed

    Banerjee, Sourav; Kundu, Tribikram; Alnuaimi, Nasser A

    2007-06-01

    Distributed point source method (DPSM) is gradually gaining popularity in the field of non-destructive evaluation (NDE). DPSM is a semi-analytical technique that can be used to calculate the ultrasonic fields produced by transducers of finite dimension placed in homogeneous or non-homogeneous media. This technique has been already used to model ultrasonic fields in homogeneous and multi-layered fluid structures. In this paper the method is extended to model the ultrasonic fields generated in both fluid and solid media near a fluid-solid interface when the transducer is placed in the fluid half-space near the interface. Most results in this paper are generated by the newly developed DPSM technique that requires matrix inversion. This technique is identified as the matrix inversion based DPSM technique. Some of these results are compared with the results produced by the Rayleigh-Sommerfield integral based DPSM technique. Theory behind both matrix inversion based and Rayleigh-Sommerfield integral based DPSM techniques is presented in this paper. The matrix inversion based DPSM technique is found to be very efficient for computing the ultrasonic field in non-homogeneous materials. One objective of this study is to model ultrasonic fields in both solids and fluids generated by the leaky Rayleigh wave when finite size transducers are inclined at Rayleigh critical angles. This phenomenon has been correctly modelled by the technique. It should be mentioned here that techniques based on paraxial assumptions fail to model the critical reflection phenomenon. Other advantages of the DPSM technique compared to the currently available techniques for transducer radiation modelling are discussed in the paper under Introduction.

  15. Multi-damage detection with embedded ultrasonic structural radar algorithm using piezoelectric wafer active sensors through advanced signal processing

    NASA Astrophysics Data System (ADS)

    Yu, Lingyu; Giurgiutiu, Victor

    2005-05-01

    The embedded ultrasonic structural radar (EUSR) algorithm was developed by using piezoelectric wafer active sensor (PWAS) array to detect defects within a large area of a thin-plate specimen. EUSR has been verified to be effective for detecting a single crack either at a broadside or at an offside position. In this research, advanced signal processing techniques were included to enhance inspection image quality and detect multiple damage. The signal processing methods include discrete wavelet transform for signal denoising, short-time Fourier transform and continuous wavelet transform for time-frequency analysis, continuous wavelet transform for frequency filtering, and Hilbert transform for envelope extraction. All these signal processing modules were implemented by developing a graphical user-friendly interface program in LabVIEW. The paper starts with an introduction of embedded ultrasonic structural radar algorithm, followed with the theoretical aspect of the phased array signal processing method. Then, the mathematical algorithms for advanced signal processing are introduced. In the end, laboratory experimental results are presented to show how efficiently the improved EUSR works. The results are analyzed and EUSR is concluded to have been improved by using the advanced signal processing techniques. The improvements include: 1) EUSR is able to provide better image of the specimen under monitoring; 2) it is able to detect multi-damage such as several cracks; 3) it is able to identify different damage types.

  16. Improved ultrasonic TV images achieved by use of Lamb-wave orientation technique

    NASA Technical Reports Server (NTRS)

    Berger, H.

    1967-01-01

    Lamb-wave sample orientation technique minimizes the interference from standing waves in continuous wave ultrasonic television imaging techniques used with thin metallic samples. The sample under investigation is oriented such that the wave incident upon it is not normal, but slightly angled.

  17. Surface displacement measured by beam distortion detection technique: Application to picosecond ultrasonics

    SciTech Connect

    Chigarev, N.; Rossignol, C.; Audoin, B.

    2006-11-15

    A sensitive technique of surface displacement measurement without interferometry is proposed for the goals of picosecond ultrasonics. Simple description of detection mechanism is provided on the basis of paraxial approximation of light diffraction. Test experiments with gold and tungsten layers have been performed and analyzed. The efficiency of the technique is compared with interferometry and reflectometry methods.

  18. Advanced Spectroscopy Technique for Biomedicine

    NASA Astrophysics Data System (ADS)

    Zhao, Jianhua; Zeng, Haishan

    This chapter presents an overview of the applications of optical spectroscopy in biomedicine. We focus on the optical design aspects of advanced biomedical spectroscopy systems, Raman spectroscopy system in particular. Detailed components and system integration are provided. As examples, two real-time in vivo Raman spectroscopy systems, one for skin cancer detection and the other for endoscopic lung cancer detection, and an in vivo confocal Raman spectroscopy system for skin assessment are presented. The applications of Raman spectroscopy in cancer diagnosis of the skin, lung, colon, oral cavity, gastrointestinal tract, breast, and cervix are summarized.

  19. Stitching Techniques Advance Optics Manufacturing

    NASA Technical Reports Server (NTRS)

    2010-01-01

    Because NASA depends on the fabrication and testing of large, high-quality aspheric (nonspherical) optics for applications like the James Webb Space Telescope, it sought an improved method for measuring large aspheres. Through Small Business Innovation Research (SBIR) awards from Goddard Space Flight Center, QED Technologies, of Rochester, New York, upgraded and enhanced its stitching technology for aspheres. QED developed the SSI-A, which earned the company an R&D 100 award, and also developed a breakthrough machine tool called the aspheric stitching interferometer. The equipment is applied to advanced optics in telescopes, microscopes, cameras, medical scopes, binoculars, and photolithography."

  20. Advanced Geophysical Environmental Simulation Techniques

    DTIC Science & Technology

    2007-11-02

    cloud property retrieval algorithms for processing of large multiple-satellite data sets; development and application of improved cloud -phase and... cloud optical property retrieval algorithms; investigation of techniques potentially applicable for retrieval of cloud spatial properties from very...14. SUBJECT TERMS cirrus cloud retrieval satellite meteorology polar-orbiting geostationary 15. NUMBER OF PAGES 16. PRICE CODE 17. SECURITY

  1. Residual stress determination of rail tread using a laser ultrasonic technique

    NASA Astrophysics Data System (ADS)

    Wang, Jing; Feng, Qibo

    2015-05-01

    A non-destructive method for measuring the residual stress on rail tread that uses a laser-generated ultrasonic technique is proposed. The residual stress distribution of different parts on both the new rail and used rail were examined. The surface acoustic waves (SAWs) are excited by a scanning line laser and detected by a laser ultrasonic detection system. A digital correlation method was used for calculating the changes in velocity of SAWs, which reflects the stress distribution. A wavelet de-noising technique and a least square fit were used for signal processing to improve the measurement accuracy. The effects of ultrasonic propagation distance and surface roughness on the determination of residual stress were analyzed and simulated. Results from the study demonstrate that the stress distribution results are accordant with the practical situation, and the laser-generated SAWs technique is a promising tool for the determination of residual stress in the railway inspection and other industrial testing fields.

  2. A study on laser-based ultrasonic technique by the use of guided wave tomographic imaging

    SciTech Connect

    Park, Junpil Lim, Juyoung; Cho, Younho; Krishnaswamy, Sridhar

    2015-03-31

    Guided wave tests are impractical for investigating specimens with limited accessibility and coarse surfaces or geometrically complicated features. A non-contact setup with a laser ultrasonic transmitter and receiver is the classic attractive for guided wave inspection. The present work was done to develop a non-contact guided-wave tomography technique by laser ultrasonic technique in a plate-like structure. A method for Lam wave generation and detection in an aluminum plate with a pulse laser ultrasonic transmitter and a Michelson interferometer receiver has been developed. In the images obtained by laser scanning, the defect shape and area showed good agreement with the actual defect. The proposed approach can be used as a non-contact-based online inspection and monitoring technique.

  3. Torsional ultrasonic technique for reactor vessel liquid level measurement

    SciTech Connect

    Dress, W.B.

    1983-01-01

    We have undertaken a detailed study of an ultrasonic waveguide employed as a level, density, and temperature sensor. The purpose of this study was to show how such a device might be used in the nuclear power industry to provide reliable level information with a multifunction sensor, thus overcomming several of the errors that led to the accident at Three Mile Island. Some additional work is needed to answer the questions raised by the current study, most noticably the damping effects of flowing water.

  4. Septoplasty: Basic and Advanced Techniques.

    PubMed

    Most, Sam P; Rudy, Shannon F

    2017-05-01

    Nasal septal deviation is a prevalent problem that can have significant quality of life ramifications. Septoplasty is commonly performed to provide qualitative and quantitative benefit to those with nasal obstruction owing to septal deviation. Although a standard, basic technique is often adequate for individuals with mild to moderate mid to posterior septal deviation, unique challenges arise with caudal septal deviation. Herein, multiple strategies that attempt to address anterior septal deviation are discussed. Anterior septal reconstruction has been shown to be a safe and effective means by which to address severe caudal septal deviation and long-term reduction in preoperative symptoms.

  5. Assessment of Alkali-Silica Reaction Damage in Mortars with Nonlinear Ultrasonic Techniques

    NASA Astrophysics Data System (ADS)

    Chen, J.; Jayapalan, A. R.; Kurtis, K. E.; Kim, J.-Y.; Jacobs, L. J.

    2008-02-01

    In this work, a nonlinear ultrasonic modulation technique is employed to assess the damage state of portland cement mortar samples induced by alkali-silica reaction (ASR). Due to the nonlinear interaction of propagating waves caused by distributed microcracks that are agitated from its equilibrium state, the ultrasonic responses of samples produce sideband frequencies around the frequency of propagating waves. The amplitude of the sidebands depends on the amplitude of the input signals and is particularly sensitive to the state of damage evolved in the sample. Therefore, the development of internal microcracks with increasing duration of exposure to aggressive conditions can be quantitatively related to the variation of external ultrasonic measurements. The ultrasonic results are compared with results from standard ASR expansion measurements (ASTM C 1260), and a proportionally increasing relation was found in the early stages. In addition, aggregates with different alkali-reactivity (i.e., low reactivity or high reactivity) were examined in a similar manner. The results indicate that the nonlinear parameter obtained from ultrasonic tests directly reflects the difference of aggregate reactivity. This clearly indicates that the developed nonlinear ultrasonic method is potentially a good alternative for a more rapid and still reliable assessment of aggregate alkali-reactivity.

  6. New technology for the design of advanced ultrasonic transducers for high-power applications.

    PubMed

    Parrini, Lorenzo

    2003-06-01

    A new high-frequency ultrasonic transducer for wire bonding has been conceived, designed, prototyped and tested. In the design phase an advanced approach was used and established. The method is based on the two basic principles of modularity and iteration. The transducer is decomposed to its elementary components. For each component an initial design is obtained with finite elements method (FEM) simulations. The simulated ultrasonic modules are then built and characterized experimentally through laser-interferometry measurements and electrical resonance spectra. The comparison of simulation results with experimental data allows the parameters of FEM models to be iteratively adjusted and optimized. The achieved FEM simulations exhibit a remarkably high-predictive potential and allow full control on the vibration behavior of the ultrasonic modules and of the whole transducer. The new transducer is fixed on the wire bonder with a flange whose special geometry was calculated by means of FEM simulations. This flange allows the converter to be attached on the wire bonder not only in longitudinal nodes but also in radial nodes of the ultrasonic field excited in the horn. This leads to a nearly complete decoupling of the transducer to the wire bonder, which has not been previously obtained. The new approach to mount ultrasonic transducers on a welding-device is of major importance not only for wire bonding but also for all high-power ultrasound applications and has been patented.

  7. Quantitative Measurements of Elastic Properties with Ultrasonic-Based AFM and Conventional Techniques

    NASA Astrophysics Data System (ADS)

    Hurley, D. C.

    A prime motivation for the original development of ultrasonic-based AFM methods was to enable measurements of elastic properties with nanoscale spatial resolution. In this chapter, we discuss the quantitative measurement of elastic modulus with ultrasonic-based AFM methods and compare it to measurement by more conventional or established techniques. First, we present the basic principles of modulus measurement with methods that involve contact resonance spectroscopy, such as atomic force acoustic microscopy (AFAM) and ultrasonic AFM (U-AFM). Fundamental concepts of modulus measurement with more established approaches, especially instrumented (nano-) indentation (NI) and surface acoustic wave spectroscopy (SAWS), are then discussed. We consider the relative strengths and limitations of various approaches, for example measurement accuracy, spatial resolution, and applicability to different materials. Example results for specific material systems are given with an emphasis on studies involving direct intercomparison of different techniques. Finally, current research in this area and opportunities for future work are described.

  8. A QUANTITATIVE ANALYSIS OF ROTARY, ULTRASONIC AND MANUAL TECHNIQUES TO TREAT PROXIMALLY FLATTENED ROOT CANALS

    PubMed Central

    Grecca, Fabiana Soares; Garcia, Roberto Brandão; Bramante, Clóvis Monteiro; de Moraes, Ivaldo Gomes; Bernardineli, Norberti

    2007-01-01

    Objective: The efficiency of rotary, manual and ultrasonic root canal instrumentation techniques was investigated in proximally flattened root canals. Material and Methods: Forty human mandibular left and right central incisors, lateral incisors and premolars were used. The pulp tissue was removed and the root canals were filled with red die. Teeth were instrumented using three techniques: (i) K3 and ProTaper rotary systems; (ii) ultrasonic crown-down technique; and (iii) progressive manual technique. Roots were bisected longitudinally in a buccolingual direction. The instrumented canal walls were digitally captured and the images obtained were analyzed using the Sigma Scan software. Canal walls were evaluated for total canal wall area versus noninstrumented area on which dye remained. Results: No statistically significant difference was found between the instrumentation techniques studied (p<0.05). Conclusion: The findings of this study showed that no instrumentation technique was 100% efficient to remove the dye. PMID:19089108

  9. Ultrasonic Nondestructive Evaluation Techniques Applied to the Quantitative Characterization of Textile Composite Materials

    NASA Technical Reports Server (NTRS)

    Miller, James G.

    1997-01-01

    In this Progress Report, we describe our further development of advanced ultrasonic nondestructive evaluation methods applied to the characterization of anisotropic materials. We present images obtained from experimental measurements of ultrasonic diffraction patterns transmitted through water only and transmitted through water and a thin woven composite. All images of diffraction patterns have been included on the accompanying CD-ROM in the JPEG format and Adobe TM Portable Document Format (PDF), in addition to the inclusion of hardcopies of the images contained in this report. In our previous semi-annual Progress Report (NAG 1-1848, December, 1996), we proposed a simple model to simulate the effect of a thin woven composite on an insonifying ultrasonic pressure field. This initial approach provided an avenue to begin development of a robust measurement method for nondestructive evaluation of anisotropic materials. In this Progress Report, we extend that work by performing experimental measurements on a single layer of a five-harness biaxial woven composite to investigate how a thin, yet architecturally complex, material interacts with the insonifying ultrasonic field. In Section 2 of this Progress Report we describe the experimental arrangement and methods for data acquisition of the ultrasonic diffraction patterns upon transmission through a thin woven composite. We also briefly describe the thin composite specimen investigated. Section 3 details the analysis of the experimental data followed by the experimental results in Section 4. Finally, a discussion of the observations and conclusions is found in Section 5.

  10. Ultrasonic Apparatus and Technique to Measure Changes in Intracranial Pressure

    NASA Astrophysics Data System (ADS)

    Yost, William T.; Cantrell, John H.

    2002-11-01

    Changes in intracranial pressure can be measured dynamically and non-invasively by monitoring one or more cerebrospinal fluid pulsatile components. Pulsatile components such as systolic and diastolic blood pressures are partially transferred to the cerebrospinal fluid by way of blood vessels contained in the surrounding brain tissue and membrane. As intracranial pressure varies these cerebrospinal fluid pulsatile components also vary. Thus, intracranial pressure can be dynamically measured. Furthermore, use of acoustics allows the measurement to be completely non-invasive. In the preferred embodiment, phase comparison of a reflected acoustic signal to a reference signal using a constant frequency pulsed phase-locked-loop ultrasonic device allows the pulsatile components to be monitored. Calibrating the device by inducing a known change in intracranial pressure allows conversion to changes in intracranial pressure.

  11. System and technique for ultrasonic characterization of settling suspensions

    DOEpatents

    Greenwood, Margaret S.; Panetta, Paul D.; Bamberger, Judith A.; Pappas, Richard A.

    2006-11-28

    A system for determining properties of settling suspensions includes a settling container, a mixer, and devices for ultrasonic interrogation transverse to the settling direction. A computer system controls operation of the mixer and the interrogation devices and records the response to the interrogating as a function of settling time, which is then used to determine suspension properties. Attenuation versus settling time for dilute suspensions, such as dilute wood pulp suspension, exhibits a peak at different settling times for suspensions having different properties, and the location of this peak is used as one mechanism for characterizing suspensions. Alternatively or in addition, a plurality of ultrasound receivers are arranged at different angles to a common transmitter to receive scattering responses at a variety of angles during particle settling. Angular differences in scattering as a function of settling time are also used to characterize the suspension.

  12. Ultrasonic Apparatus and Technique to Measure Changes in Intracranial Pressure

    NASA Technical Reports Server (NTRS)

    Yost, William T. (Inventor); Cantrell, John H. (Inventor)

    2002-01-01

    Changes in intracranial pressure can be measured dynamically and non-invasively by monitoring one or more cerebrospinal fluid pulsatile components. Pulsatile components such as systolic and diastolic blood pressures are partially transferred to the cerebrospinal fluid by way of blood vessels contained in the surrounding brain tissue and membrane. As intracranial pressure varies these cerebrospinal fluid pulsatile components also vary. Thus, intracranial pressure can be dynamically measured. Furthermore, use of acoustics allows the measurement to be completely non-invasive. In the preferred embodiment, phase comparison of a reflected acoustic signal to a reference signal using a constant frequency pulsed phase-locked-loop ultrasonic device allows the pulsatile components to be monitored. Calibrating the device by inducing a known change in intracranial pressure allows conversion to changes in intracranial pressure.

  13. Advanced instrumentation for acousto-ultrasonic based structural health monitoring

    NASA Astrophysics Data System (ADS)

    Smithard, Joel; Galea, Steve; van der Velden, Stephen; Powlesland, Ian; Jung, George; Rajic, Nik

    2016-04-01

    Structural health monitoring (SHM) systems using structurally-integrated sensors potentially allow the ability to inspect for damage in aircraft structures on-demand and could provide a basis for the development of condition-based maintenance approaches for airframes. These systems potentially offer both substantial cost savings and performance improvements over conventional nondestructive inspection (NDI). Acousto-ultrasonics (AU), using structurallyintegrated piezoelectric transducers, offers a promising basis for broad-field damage detection in aircraft structures. For these systems to be successfully applied in the field the hardware for AU excitation and interrogation needs to be easy to use, compact, portable, light and, electrically and mechanically robust. Highly flexible and inexpensive instrumentation for basic background laboratory investigations is also required to allow researchers to tackle the numerous scientific and engineering issues associated with AU based SHM. The Australian Defence Science and Technology Group (DST Group) has developed the Acousto Ultrasonic Structural health monitoring Array Module (AUSAM+), a compact device for AU excitation and interrogation. The module, which has the footprint of a typical current generation smart phone, provides autonomous control of four send and receive piezoelectric elements, which can operate in pitch-catch or pulse-echo modes and can undertake electro-mechanical impedance measurements for transducer and structural diagnostics. Modules are designed to operate synchronously with other units, via an optical link, to accommodate larger transducer arrays. The module also caters for fibre optic sensing of acoustic waves with four intensity-based optical inputs. Temperature and electrical resistance strain gauge inputs as well as external triggering functionality are also provided. The development of a Matlab hardware object allows users to easily access the full hardware functionality of the device and

  14. Technique for ultrasonic cleaning with volatile solvents eliminates need for hoods or condensers

    NASA Technical Reports Server (NTRS)

    Pipersky, E.

    1969-01-01

    Technique ultrasonically cleans small quantities of small mechanical parts in organic solvents without the need for vapor removal equipment. Parts are placed in a thin plastic bag with the solvent and then suspended in a cleaning tank containing the water-detergent solution.

  15. Acousto-ultrasonic nondestructive evaluation of materials using laser beam generation and detection

    NASA Technical Reports Server (NTRS)

    Huber, Robert D.; Green, Robert E., Jr.; Vary, Alex; Kautz, Harold

    1990-01-01

    Presented in viewgraph format, the possibility of using laser generation and detection of ultrasound to replace piezoelectric transducers for the acousto-ultrasonic technique is advanced. The advantages and disadvantages of laser acousto-ultrasonics are outlined. Laser acousto-ultrasonics complements standard piezoelectric acousto-ultrasonics and offers non-contact nondestructive evaluation.

  16. Assessment of damage in ceramics and ceramic matrix composites using ultrasonic techniques

    NASA Technical Reports Server (NTRS)

    Chu, Y. C.; Baaklini, G. Y.; Rokhlin, S.I.

    1993-01-01

    This paper addresses the application of ultrasonic sensing to damage assessment in ceramics and ceramic matrix composites. It focuses on damage caused by thermal shock or oxidation at elevated temperatures, which often results in elastic anisotropy. This damaged-induced anisotropy is determined by measuring the velocities of ultrasonic waves in different propagation directions. Thermal shock damage is assessed in ceramic samples of reaction bonded silicon nitride (RBSN). Thermal shock treatment from different temperatures up to 1000 C is applied to produce the microcracks. Results indicate that most microcracks produced by thermal shock are located near sample surfaces. Ultrasonic measurements using the surface wave method are found to correlate well with measurements of degradation of mechanical properties obtained independently by other authors using destructive methods. Oxidation damage is assessed in silicon carbide fiber/reaction bonded silicon nitride matrix (SCS-6/RBSN) composites. The oxidation is done by exposing the samples in a flowing oxygen environment at elevated temperatures, up to 1400 C, for 100 hr. The Youngs' modulus in the fiber direction as obtained from ultrasonic measurements decreases significantly at 600 C but retains its original value at temperatures above 1200 C. This agrees well with the results of destructive tests by other authors. On the other hand, the transverse moduli obtained from ultrasonic measurements decrease continually until 1200 C. Measurements on the shear stiffnesses show behavior similar to the transverse moduli. The results of this work show that the damage-induced anisotropy in both ceramics and ceramic matrix composites can be determined successfully by ultrasonic methods. This suggests the possibility of assessing damage severity using ultrasonic techniques.

  17. [Research on high-frequency ultrasonic tissue harmonic information extraction based on phase inversion technique].

    PubMed

    Li, Yue-Jie; Tang, Si-Yuan; Wang, Li-Wei; Li, Song

    2008-11-01

    Based on the pulse-coded transmitting and wide-band receiving system, this paper describes A research of phase inversion technique to extract high-frequency ultrasonic tissue harmonic information by making use of wide-band ultrasonic transducer on frequency of 20 MHz, 35 MHz and 50 MHz. The results indicate that adopting the method in this paper is with better fundamental frequency inhibition and at the same time can increase the amplitude of second harmonic information effectively. This method is superior to that traditoncal one by using RF filter to extract tissue harmonic information.

  18. Ultrasonic Nondestructive Evaluation Techniques Applied to the Quantitative Characterization of Textile Composite Materials

    NASA Technical Reports Server (NTRS)

    Miller, James G.

    1997-01-01

    In this Progress Report, we describe our recent developments of advanced ultrasonic nondestructive evaluation methods applied to the characterization of anisotropic materials. We present images obtained from experimental measurements of ultrasonic diffraction patterns for a thin woven composite in an immersion setup. In addition, we compare apparent signal loss measurements of the thin woven composite for phase-sensitive and phase-insensitive detection methods. All images of diffraction patterns have been included on the accompanying CD-ROM in the Adobe(Trademark) Portable Document Format (PDF). Due to the extensive amount of data, however, hardcopies of only a small representative selection of the images are included within the printed report. This Progress Report presents experimental results that support successful implementation of single element as well as one and two-dimensional ultrasonic array technologies for the inspection of textile composite structures. In our previous reports, we have addressed issues regarding beam profiles of ultrasonic pressure fields transmitted through a water reference path and transmitted through a thin woven composite sample path. Furthermore, we presented experimental results of the effect of a thin woven composite on the magnitude of an insonifying ultrasonic pressure field. In addition to the study of ultrasonic beam profiles, we consider issues relevant to the application of single-element, one-dimensional, and two-dimensional array technologies towards probing the mechanical properties of advanced engineering composites and structures. We provide comparisons between phase-sensitive and phase-insensitive detection methods for determination of textile composite structure parameters. We also compare phase-sensitive and phase-insensitive - - ---- ----- apparent signal loss measurements in an effort to study the phenomenon of phase cancellation at the face of a finite-aperture single-element receiver. Furthermore, in this

  19. In-Situ Measurement of Internal Temperature Distribution of Sintered Materials Using Ultrasonic Technique

    NASA Astrophysics Data System (ADS)

    Ihara, I.; Tomomatsu, T.

    2011-03-01

    It is often required to measure internal temperature distribution of a heated material because it is closely related to the materials properties and behavior. In this work, an effective ultrasonic method has been applied to the monitoring of internal temperature distributions of an alumina being heated. The principle of the method is based on the temperature dependence of the velocity of ultrasound propagating through a heated material. In the method, a combined technique of ultrasonic pulse-echo measurements and a finite difference calculation is employed to determine the one-dimensional temperature distribution in a heated material. Shear wave is used for the ultrasonic measurements to improve the accuracy in determining temperature. To verify the feasibility of the method, pulse-echo measurements with a shear wave transducer have been performed for an alumina rod of 14 mm diameter and 25 mm length whose single-end is being heated. The internal temperature distribution and its variation of the alumina are then measured during the heating. The temperature distributions determined by the ultrasonic method almost agree with those obtained by an infrared method. Thus, it is demonstrated that the ultrasonic method has the potential for in-process monitoring of the transient temperature variation of ceramics being processed at high temperatures.

  20. Nondestructive characterization of thermal barrier coating by noncontact laser ultrasonic technique

    NASA Astrophysics Data System (ADS)

    Zhao, Yang; Chen, Jianwei; Zhang, Zhenzhen

    2015-09-01

    We present the application of a laser ultrasonic technique in nondestructive characterization of the bonding layer (BL) in a thermal barrier coating (TBC). A physical mode of a multilayered medium is established to describe the propagation of a longitudinal wave generated by a laser in a TBC system. Furthermore, the theoretical analysis on the ultrasonic transmission in TBC is carried out in order to derive the expression of the BL transmission coefficient spectrum (TCS) which is used to determine the velocity of the longitudinal wave in the BL. We employ the inversion method combined with TCS to ascertain the attenuation coefficient of the BL. The experimental validations are performed with TBC specimens produced by an electron-beam physical vapor deposition method. In those experiments, a pulsed laser with a width of 10 ns is used to generate an ultrasonic signal while a two-wave mixing interferometer is created to receive the ultrasonic signals. By introducing the wavelet soft-threshold method that improves the signal-to-noise ratio, the laser ultrasonic testing results of TBC with an oxidation of 1 cycle, 10 cycles, and 100 cycles show that the attenuation coefficients of the BL become larger with an increase in the oxidation time, which is evident for the scanning electron microscopy observations, in which the thickness of the thermally grown oxide increases with oxidation time.

  1. The development of ultrasonic techniques for nondestructive evaluation of adhesive bonds

    NASA Astrophysics Data System (ADS)

    Chapman, Gilbert B., II

    Demands for improvements in aerospace and automotive energy-efficiency, performance, corrosion resistance, body stiffness and style have increased the use of adhesive bonds to help meet those demands by providing joining technology that accommodates a wider variety of materials and design options. However, the history of adhesive bond performance clearly indicates the need for a robust method of assuring the existence of the required consistent level of adhesive bond integrity in every bonded region. This investigation seeks to meet that need by the development of new, complementary ultrasonic techniques for the evaluation of these bonds, and thus provide improvements over previous methods by extending the range of resolution, speed and applications. The development of a 20 MHz pulse-echo method for nondestructive evaluation of adhesive bonds will accomplish the assessment of bond joints with adhesive as thin as 0.1 mm. This new method advances the state of the art by providing a high-resolution, phase-sensitive procedure that identifies the bond state at each interface of the adhesive with the substrate(s), by the acquisition and analysis of acoustic echoes reflected from interfaces between layers with large acoustic impedance mismatch. Because interface echo amplitudes are marginal when the acoustic impedance of the substrate is close to that of the adhesive, a 25 kHz Lamb wave technique was developed to be employed in such cases, albeit with reduced resolution. Modeling the ultrasonic echoes and Lamb-wave signals was accomplished using mathematical expressions developed from the physics of acoustic transmission, attenuation and reflection in layered media. The models were validated by experimental results from a variety of bond joint materials, geometries and conditions, thereby confirming the validity of the methodology used for extracting interpretations from the phase-sensitive indications, as well as identifying the range and limits of applications. Results

  2. New acousto-ultrasonic techniques applied to aerospace materials

    NASA Technical Reports Server (NTRS)

    Kautz, Harold E.

    1988-01-01

    The use of an NdYAG pulsed laser for generating ultrasonic waves for NDE in resin matrix composites was investigated. A study was conducted of the use of the 1.064 micron wavelength NdYAG pulsed laser with the neat, unreinforced resin as well as graphite fiber/polymer composite specimens. In the case of the neat resins it was found that, at normal incidence, about 25 percent of the laser pulse energy was reflected at the incident surface. An attenuation coefficient for the polyimide resin, PMR-15 was determined to be approximately 5.8 np/cm. It was found in energy balance studies that graphite fiber/polymer specimens attenuate the laser beam more than do neat resins. The increase absorption is in the graphite fibers. The occurrence of laser induced surface damage was also studied. For the polymer neat resin, damage appears as pit formation over a small fraction of the pulse impact area and discoloration over a larger part of the area. A damage threshold was inferred from observed damage as a function of pulse energy. The 600 F cured PMR-15 and PMR-11 exhibit about the same amount of damage for a given laser pulse energy. The damage threshold is between 0.06 and 0.07 J/sq cm.

  3. An adaptive ultrasonic backscattered signal processing technique for instantaneous characteristic frequency detection.

    PubMed

    Jin, Bo; Vai, Mang I

    2014-01-01

    Ultrasonic diagnosis that is convenient and nondestructive to the human body is widely used in medicine. In clinical, ultrasonic backscattered signals characteristics are utilized to acquire information of the human body tissues to perform diagnosis. In this paper, an adaptive ultrasonic backscattered signal processing technique for instantaneous characteristic frequency detection based on the marginal spectrum is presented. In the beginning, the ultrasonic backscattered signal is decomposed into a series of intrinsic mode functions (IMFs) by the Ensemble Empirical Mode Decomposition (EEMD) algorithm. Then the Hilbert spectrum is gained by the Hilbert transform on the IMFs decomposed and screened. Finally, the time-frequency information in the Hilbert spectrum is utilized to extract the instantaneous characteristic frequency based on the marginal spectrum features to detect the objective. With this technique, the spacing between tissues can be estimated for tissue characterization by processing multiple echoes even in the complicated environment. In the simulation study, comparing with the FFT, the technique presented shows its strong noise immunity and indicates its validity in instantaneous characteristic frequency detection.

  4. Extraction of organochlorine pesticides in sediments using soxhlet, ultrasonic and accelerated solvent extraction techniques

    NASA Astrophysics Data System (ADS)

    Lang, Yinhai; Cao, Zhengmei; Nie, Xinhua

    2005-04-01

    The application of soxhlet, ultrasonic and accelerated solvent extraction techniques to the analysis of six organochlorine pesticides (α-HCH, β-HCH, γ-HCH, o, p‧-DDT, p, p‧-DDT and p, p‧-DDE) in Taihu Lake sediment samples is described. It was found that the limits of quantification ranged from 0.002 µgg-1 to 0.004 µgg-1, and the recoveries of organochlorine pesticides with the three extraction techniques were acceptable (>80.7%). With a mass selective detector, better results were obtained by accelerated solvent extraction using hexane-acetone (1:1) as compared with soxhlet and ultrasonic extraction. It was shown that the accelerated solvent extraction was the optimum technique for the analysis of organochlorine pesticides in sediments. The general features of the three extraction techniques are also presented.

  5. Dehydration kinetics of salmon and trout fillets using ultrasonic vacuum drying as a novel technique.

    PubMed

    Başlar, Mehmet; Kılıçlı, Mahmut; Yalınkılıç, Barış

    2015-11-01

    In this study, a novel ultrasonic vacuum (USV) drying technique was used to shorten the drying time of fish fillets. For this purpose, ultrasonic treatment and vacuum-drying were simultaneously performed to dehydrate salmon and trout fillets at 55°C, 65°C, and 75°C. In addition, the USV technique was compared with vacuum-drying and oven-drying techniques. The dehydration kinetics of the fillets was successfully described by seven thin-layer drying models with R(2) range between 0.944 and 1.000. Depending on drying temperatures and fish species, the drying times could be shortened using the USV technique between 7.4% and 27.4% compared with vacuum-drying. The highest effective moisture diffusivity was determined in the fillets dried with the USV technique and they increased with increasing drying temperatures. Ultrasonic treatment accelerated the vacuum drying process for the fillets; therefore, this technique could be used to improve the efficiency of vacuum-drying for the fillets.

  6. Hybrid mesh generation using advancing reduction technique

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study presents an extension of the application of the advancing reduction technique to the hybrid mesh generation. The proposed algorithm is based on a pre-generated rectangle mesh (RM) with a certain orientation. The intersection points between the two sets of perpendicular mesh lines in RM an...

  7. Advanced techniques for future observations from space

    NASA Technical Reports Server (NTRS)

    Hinkley, E. D.

    1980-01-01

    Advanced remote sensing techniques for the study of global meteorology and the chemistry of the atmosphere are considered. Remote sensing from Spacelab/Shuttle and free-flying satellites will provide the platforms for instrumentation based on advanced technology. Several laser systems are being developed for the measurement of tropospheric winds and pressure, and trace species in the troposphere and stratosphere. In addition, a high-resolution passive infrared sensor shows promise for measuring temperature from sea level up through the stratosphere. Advanced optical and microwave instruments are being developed for wind measurements in the stratosphere and mesosphere. Microwave techniques are also useful for the study of meteorological parameters at the air-sea interface.

  8. Application of laser ultrasonic non-destructive evaluation technique to additive manufacturing

    NASA Astrophysics Data System (ADS)

    Manzo, Anthony J.; Kenderian, Shant; Helvajian, Henry

    2016-04-01

    The change in properties of a propagating ultrasonic wave has been a mainstay characterization tool of the nondestructive evaluation (NDE) industry for identifying subsurface defects (e.g. damage). A variant of this concept could be applicable to 3D additive manufacturing where the existence of defects (e.g. pores) within a sub-layer could mark a product as non-qualifying. We have been exploring the utility of pulsed laser ultrasonic excitation coupled with CW laser heterodyne detection as an all optical scheme for characterizing sub surface layer properties. The all-optical approach permits a straight forward integration into a laser additive processing tool. To test the concept, we have developed an experimental system that generates pulsed ultrasonic waves (the probe) with high bandwidth (<<10MHz) and a surface displacement sensor that can capture the ultrasonic "return" signal with bandwidth close to 300 MHz. The use of high frequencies enables the detection of smaller defect sites. The technique is time resolved with the sensor and probe as point (>>30-200 microns) beams. Current tests include characterizing properties of spot weld joints between two thin stainless steel plates. The long term objective is to transition the technique into a laser additive manufacturing tool.

  9. Nuclear Technology. Course 32: Nondestructive Examination (NDE) Techniques II. Module 32-1, Fundamentals of Ultrasonic Testing.

    ERIC Educational Resources Information Center

    Spaulding, Bruce

    This first in a series of six modules for a course titled Nondestructive Examination (NDE) Techniques II introduces the student/trainee to the basic behavior of ultrasound, describes ultrasonic test equipment, and outlines the principal methods of ultrasonic testing. The module follows a typical format that includes the following sections: (1)…

  10. Sizing defects using annular-array techniques with an automatic ultrasonic data-acquisition system

    SciTech Connect

    Gieske, J.H.; Stoker, G.C.; Walkington, P.D.

    1983-01-01

    The results of sizing internal flaws by a annular phased array technique are presented. The data was taken using a microprocessor controlled phased array pulser/receiver operated with a minicomputer ultrasonic data acquisition system. Flat bottom holes of two sizes which were machined in an aluminum block at various depths were used as targets. Sizing of these targets by the annular array technique is compared with sizing by conventional flat and focused single transducer techniques. The results show that the measured flaw size determined by the annular array technique is to a large extent independent of echo amplitude and flaw depth.

  11. Innovative Ultrasonic Techniques for Inspection and Monitoring of Large Concrete Structures

    NASA Astrophysics Data System (ADS)

    Wiggenhauser, H.; Niederleithinger, E.

    2013-07-01

    Ultrasonic echo and transmission techniques are used in civil engineering on a regular basis. New sensors and data processing techniques have lead to many new applications in the structural investigation as well as quality control. But concrete structures in the nuclear sector have special features and parameters, which pose problems for the methods and instrumentation currently available, e.g. extreme thickness, dense reinforcement, steel liners or special materials. Several innovative ultrasonic techniques have been developed to deal with these issues at least partly in lab experiments and pilot studies. Modern imaging techniques as multi-offset SAFT have been used e. g. to map delaminations. Thick concrete walls have successfully been inspected, partly through a steel liner. Embedded ultrasonic sensors have been designed which will be used in monitoring networks of large concrete structures above and below ground. In addition, sensitive mathematical methods as coda wave interferometry have been successfully evaluated to detect subtle changes in material properties. Examples of measurements and data evaluation are presented.

  12. Physical principles of ultrasonic non-destructive evaluation of advanced composites

    NASA Technical Reports Server (NTRS)

    Miller, James G.

    1988-01-01

    Results are presented from the continued investigations into the use of ultrasonic measurement techniques for the detection and characterization of porosity. The effects that bleeder cloth impressions (left after the cure process) have on the capability of polar backscatter to interrogate volume effects such as porosity are described. Some preliminary data regarding a comparison of phase sensitive and phase insensitivie detection for materials characterization is presented.

  13. Quantitative Mapping of Pore Fraction Variations in Silicon Nitride Using an Ultrasonic Contact Scan Technique

    NASA Technical Reports Server (NTRS)

    Roth, Don J.; Kiser, James D.; Swickard, Suzanne M.; Szatmary, Steven A.; Kerwin, David P.

    1993-01-01

    An ultrasonic scan procedure using the pulse-echo contact configuration was employed to obtain maps of pore fraction variations in sintered silicon nitride samples in terms of ultrasonic material properties. Ultrasonic velocity, attenuation coefficient, and reflection coefficient images were obtained simultaneously over a broad band of frequencies (e.g., 30 to 110 MHz) by using spectroscopic analysis. Liquid and membrane (dry) coupling techniques and longitudinal and shear-wave energies were used. The major results include the following: Ultrasonic velocity (longitudinal and shear wave) images revealed and correlated with the extent of average through-thickness pore fraction variations in the silicon nitride disks. Attenuation coefficient images revealed pore fraction nonuniformity due to the scattering that occurred at boundaries between regions of high and low pore fraction. Velocity and attenuation coefficient images were each nearly identical for machined and polished disks, making the method readily applicable to machined materials. Velocity images were similar for wet and membrane coupling. Maps of apparent Poisson's ratio constructed from longitudinal and shear-wave velocities quantified Poisson's ratio variations across a silicon nitride disk. Thermal wave images of a disk indicated transient thermal behavior variations that correlated with observed variations in pore fraction and velocity and attenuation coefficients.

  14. An Ultrasonic Technique to Determine the Residual Strength of Adhesive Bonds

    NASA Technical Reports Server (NTRS)

    Achenbach, J. D.; Tang, Z.

    1999-01-01

    In this work, ultrasonic techniques to nondestructively evaluate adhesive bond degradation have been studied. The key to the present approach is the introduction of an external factor which pulls the adhesive bond in the nonlinear range, simultaneously with the application of an ultrasonic technique. With the aid of an external static tensile loading, a superimposed longitudinal wave has.been used to obtain the slopes of the stress-strain curve of an adhesive bond at a series of load levels. The critical load, at which a reduction of the slope is detected by the superimposed longitudinal wave, is an indication of the onset of nonlinear behavior of the adhesive bond, and therefore of bond degradation. This approach has been applied to the detection of adhesive bond degradation induced by cyclic fatigue loading. Analogously to the longitudinal wave case, a superimposed shear wave has been used to obtain the effective shear modulus of adhesive layers at different shear load levels. The onset of the nonlinear behavior of an adhesive bond under shear loading has been detected by the use of a superimposed shear wave. Experiments show that a longitudinal wave can also detect the nonlinear behavior when an adhesive bond is subjected to shear loading. An optimal combination of ultrasonic testing and mechanical loading methods for the detection of degradation related nonlinear behavior of adhesive bonds has been discussed. For the purpose of a practical application, an ultrasonic technique that uses a temperature increase as an alternative to static loading has also been investigated. A general strain-temperature correspondence principle that relates a mechanical strain to a temperature has been presented. Explicit strain-temperature correspondence relations for both the tension and shear cases have been derived. An important parameter which quantifies the relation between the wave velocity and temperature has been defined. This parameter, which is indicative of adhesive

  15. Monitoring of Lactic Fermentation Process by Ultrasonic Technique

    NASA Astrophysics Data System (ADS)

    Alouache, B.; Touat, A.; Boutkedjirt, T.; Bennamane, A.

    The non-destructive control by using ultrasound techniques has become of great importance in food industry. In this work, Ultrasound has been used for quality control and monitoring the fermentation stages of yogurt, which is a highly consumed product. On the contrary to the physico-chemical methods, where the measurement instruments are directly introduced in the sample, ultrasound techniques have the advantage of being non-destructive and contactless, thus reducing the risk of contamination. Results obtained in this study by using ultrasound seem to be in good agreement with those obtained by physico-chemical methods such as acidity measurement by using a PH-meter instrument. This lets us to conclude that ultrasound method may be an alternative for a healthy control of yoghurt fermentation process.

  16. The Application of Phased Array Ultrasonic Techniques for Inspection of Railway Axles from Their End Face

    NASA Astrophysics Data System (ADS)

    Liaptsis, D.; Cooper, I.; Boyle, K.; Nicholson, P. I.

    2011-06-01

    As part of the development of a non destructive testing (NDT) system combining complementary inspection techniques, an inspection system based on phased array ultrasonic testing (PAUT) for detection of transverse cracking in solid railway axles is being developed. This paper presents the initial study, which includes the PAUT experimental setup and the initial results obtained after testing the system on railway axle blocks. The inspection of solid axles from their axle end face is investigated.

  17. Analysis of echoes in ultrasonic testing for round bar using angle beam immersion technique

    NASA Astrophysics Data System (ADS)

    Kimura, T.; Kameyama, S.; Misu, K.; Wadaka, S.; Tanaka, H.

    2001-04-01

    A design is presented for a probe, used for automatic ultrasonic testing for a round bar using the angle beam immersion technique, to improve a signal to noise ratio. It is defined based on a flaw echo height and a spurious echo height, taking into consideration of a time gate and variation of the flaw echo height along with a rotation of the probe round the bar. The result of the design is in good agreement with that of experiments.

  18. Measurements of dynamic Young's modulus in short specimens with the PUCOT. [Piezoelectric Ultrasonic Composite Oscillator Technique

    NASA Technical Reports Server (NTRS)

    Wickstrom, S. N.; Wolfenden, A.

    1990-01-01

    The piezoelectric ultrasonic composite oscillator technique (PUCOT) was used at frequencies in the range 40 to 150 kHz to measure dynamic Young's modulus for short-length single crystals of copper at temperatures in the range 25 to 650 C and for polycrystalline copper at room temperature. Corrections to the modulus for variations in length/diameter resulted in no loss of precision due to wave velocity dispersion.

  19. Advanced Computational Techniques in Regional Wave Studies

    DTIC Science & Technology

    1990-01-03

    the new GERESS data. The dissertation work emphasized the development and use of advanced computa- tional techniques for studying regional seismic...hand, the possibility of new data sources at regional distances permits using previously ignored signals. Unfortunately, these regional signals will...the Green’s function around this new reference point is containing the propagation effects, and V is the source Gnk(x,t;r,t) - (2) volume where fJk

  20. Comparative evaluation of aerospace composites using thermography and ultrasonic NDT techniques

    NASA Astrophysics Data System (ADS)

    Theodorakeas, P.; Avdelidis, N. P.; Hatziioannidis, I.; Cheilakou, E.; Marini, R.; Koui, M.

    2015-05-01

    In the present research work a study was carried out evaluating the applicability of two NDT techniques, this of Transient Thermography (TT) and Ultrasonic Testing (UT) for the inspection of different types of composite materials (i.e. laminated CFRPs, laminated hybrid FRPs and sandwiched panels). The composite structures were consisted of a variety of artificial defects, while inspection was performed through different testing configurations. In particular, transient thermography was implemented through the monitoring of the surface transient cooling after flash heating the samples and ultrasonic testing was applied using both a conventional single element probe (immersion technique) and a linear phased array transducer consisted of 128 elements. The main objective of this work was to compare the applicability and effectiveness of the two techniques in aerospace composites inspection as well as to evaluate the accuracy produced regarding the quantitative characterisation of the detected features. The obtained results showed that all the defects were revealed by either transient thermography or ultrasonic testing, whilst thermographic inspection can display the acquired results in a more rapid manner. On the other hand UT testing can provide efficient results for deeper probing requiring however longer inspection times. In other words, the acquired data and the respective analyses highlighted the different capability of each testing configuration, to detect defects and to gain knowledge for the interior of the structures.

  1. Laser ultrasonic techniques for assessment of tooth structure

    NASA Astrophysics Data System (ADS)

    Blodgett, David W.; Baldwin, Kevin C.

    2000-06-01

    Dental health care and research workers require a means of imaging the structures within teeth in vivo. For example, there is a need to image the margins of a restoration for the detection of poor bonding or voids between the restorative material and the dentin. With conventional x-ray techniques, it is difficult to detect cracks and to visualize interfaces between hard media. This due to the x-ray providing only a 2 dimensional projection of the internal structure (i.e. a silhouette). In addition, a high resolution imaging modality is needed to detect tooth decay in its early stages. If decay can be detected early enough, the process can be monitored and interventional procedures, such as fluoride washes and controlled diet, can be initiated which can help the tooth to re-mineralize itself. Currently employed x-ray imaging is incapable of detecting decay at a stage early enough to avoid invasive cavity preparation followed by a restoration with a synthetic material. Other clinical applications include the visualization of periodontal defects, the localization of intraosseous lesions, and determining the degree of osseointegration between a dental implant and the surrounding bone. A means of assessing the internal structure of the tooth based upon use of high frequency, highly localized ultrasound (acoustic waves) generated by a laser pulse is discussed. Optical interferometric detection of ultrasound provides a complementary technique with a very small detection footprint. Initial results using laser-based ultrasound for assessment of dental structures are presented. Discussion will center on the adaptability of this technique to clinical applications.

  2. Advanced Ultrasonic Diagnosis of Extremity Trauma: The Faster Exam

    NASA Technical Reports Server (NTRS)

    Dulchavsky, S. A.; Henry, S. E.; Moed, B. R.; Diebel, L. N.; Marshburn, T.; Hamilton, D. R.; Logan, J.; Kirkpatrick, A. W.; Williams, D. R.

    2002-01-01

    Ultrasound is of prO)len accuracy in abdominal and thoracic trauma and may be useful to diagnose extremity injury in situations where radiography is not available such as military and space applications. We prospectively evaluated the utility of extremity , ultrasound performed by trained, non-physician personnel in patients with extremity trauma, to simulate remote aerospace or military applications . Methods: Patients with extremity trauma were identified by history, physical examination, and radiographic studies. Ultrasound examination was performed bilaterally by nonphysician personnel with a portable ultrasound device using a 10-5 MHz linear probe, Images were video-recorded for later analysis against radiography by Fisher's exact test. The average time of examination was 4 minutes. Ultrasound accurately diagnosed extremity, injury in 94% of patients with no false positive exams; accuracy was greater in mid-shaft locations and least in the metacarpa/metatarsals. Soft tissue/tendon injury was readily visualized . Extremity ultrasound can be performed quickly and accurately by nonphysician personnel with excellent accuracy. Blinded verification of the utility of ultrasound in patients with extremity injury should be done to determine if Extremity and Respiratory evaluation should be added to the FAST examination (the FASTER exam) and verify the technique in remote locations such as military and aerospace applications.

  3. Ultrasonic atomization for spray drying: a versatile technique for the preparation of protein loaded biodegradable microspheres.

    PubMed

    Bittner, B; Kissel, T

    1999-01-01

    Bovine serum albumin (BDA) loaded microspheres with a spherical shape and smooth surface structure were successfully prepared from poly(lactide-co-glycolide) using an ultrasonic nozzle installed in a Niro laboratory spray dryer. Process and formulation parameters were investigated with respect to their influence on microsphere characteristics, such as particle size, loading capacity, and release properties. Preparation of microspheres in yields of more than 50% was achieved using an ultrasonic atomizer connected to a stream of carrier air. Microsphere characteristics could be modified by changing several technological parameters. An increased polymer concentration of the feed generated larger particles with a significantly reduced initial release of the protein. Moreover, microspheres with a smooth surface structure were obtained from the organic polymer solution with the highest viscosity. Microparticles with a low BSA loading showed a large central cavity surrounded by a thin polymer layer in scanning electron microspheres. A high protein loading led to an enlargement of the shell layer, or even to dense particles without any cavities. A continuous in vitro release pattern of BSA was obtained from the particles with low protein loading. Glass transition temperatures (Tg) of the microspheres before and after lyophilization did not differ from those of the BSA loaded particles prepared by spray drying with a rotary atomizer. Analysis of the polymer by gel permeation chromatography indicated that ultrasonication had no effect on polymer molecular weight. Molecular weight and polydispersity of the pure polymer, placebo microspheres prepared by spray drying, and placebo microspheres prepared using the ultrasonic nozzle were in the same range. In conclusion, ultrasonic atomization represents a versatile and reliable technique for the production of protein loaded biodegradable microspheres without inducing a degradation of the polymer matrix. Particle characteristics

  4. Advanced ultrasonic inspection system for the ID-inspection of reactor pressure vessels of BWRs

    SciTech Connect

    Fischer, E.; Wuestenberg, H.; Tagliamonte, M.; Dalichow, M.

    1994-12-31

    A newly-developed, modular ultrasonic examination system has been developed by Siemens for the ID inspection of BWR RPV`S. It is based on the phased-array technique with hybrid probes using the latest in manipulator and control equipment technology to allow the often hard-to-access weld areas of older reactor pressure vessels in US BWR plants to be examined within a very short time and with minimal radiation exposure of the examination personnel. New NRC stipulations requiring almost complete ultrasonic examination of all RPV welds can be fully satisfied using this system for the ID inspection of all longitudinal and circumferential welds above the jet pump baffle plate.

  5. Sono-bromination of aromatic compounds based on the ultrasonic advanced oxidation processes.

    PubMed

    Fujita, Mitsue; Lévêque, Jean-Marc; Komatsu, Naoki; Kimura, Takahide

    2015-11-01

    A novel, mild "sono-halogenation" of various aromatic compounds with potassium halide was investigated under ultrasound in a biphasic carbon tetrachloride/water medium. The feasibility study was first undertaken with the potassium bromide and then extended to chloride and iodide analogues. This methodology could be considered as a new expansion of the ultrasonic advanced oxidation processes (UAOPs) into a synthetic aspect as the developed methodology is linked to the sonolytic disappearance of carbon tetrachloride. Advantages of the present method are not only that the manipulation of the bromination is simple and green, but also that the halogenating agents used are readily available, inexpensive, and easy-handling.

  6. Advanced Test Reactor In-Canal Ultrasonic Scanner: Experiment Design and Initial Results on Irradiated Plates

    SciTech Connect

    D. M. Wachs; J. M. Wight; D. T. Clark; J. M. Williams; S. C. Taylor; D. J. Utterbeck; G. L. Hawkes; G. S. Chang; R. G. Ambrosek; N. C. Craft

    2008-09-01

    An irradiation test device has been developed to support testing of prototypic scale plate type fuels in the Advanced Test Reactor. The experiment hardware and operating conditions were optimized to provide the irradiation conditions necessary to conduct performance and qualification tests on research reactor type fuels for the RERTR program. The device was designed to allow disassembly and reassembly in the ATR spent fuel canal so that interim inspections could be performed on the fuel plates. An ultrasonic scanner was developed to perform dimensional and transmission inspections during these interim investigations. Example results from the AFIP-2 experiment are presented.

  7. Generalized frequency-domain synthetic aperture focusing technique for ultrasonic imaging of irregularly layered objects.

    PubMed

    Qin, Kaihuai; Yang, Chun; Sun, Feng

    2014-01-01

    In ultrasonic nondestructive testing (NDT), the phase shift migration (PSM) technique, as a frequency-domain implementation of the synthetic aperture focusing technique (SAFT), can be adopted for imaging of regularly layered objects that are inhomogeneous only in depth but isotropic and homogeneous in the lateral direction. To deal with irregularly layered objects that are anisotropic and inhomogeneous in both the depth and lateral directions, a generalized frequency- domain SAFT, called generalized phase shift migration (GPSM), is proposed in this paper. Compared with PSM, the most significant innovation of GPSM is that the phase shift factor is generalized to handle anisotropic media with lateral velocity variations. The generalization is accomplished by computer programming techniques without modifying the PSM model. In addition, SRFFT (split-radix fast Fourier transform) input/output pruning algorithms are developed and employed in the GPSM algorithm to speed up the image reconstructions. The experiments show that the proposed imaging techniques are capable of reconstructing accurate shapes and interfaces of irregularly layered objects. The computing time of the GPSM algorithm is much less than the time-domain SAFT combined with the ray-tracing technique, which is, at present, the common method used in ultrasonic NDT industry for imaging layered objects. Furthermore, imaging regularly layered objects can be regarded as a special case of the presented technique.

  8. Development of guided wave ultrasonic techniques for detection of corrosion under insulation in metal pipe

    SciTech Connect

    Bray, A.V.; Corley, C.J.; Fischer, R.B.; Rose, J.L.; Quarry, M.J.

    1998-12-31

    A unique capability has been developed in the application of guided wave (GW) ultrasonic techniques for nondestructive evaluation (NDE) of insulated pipe. Many guided wave modes are established in pipe walls when excited by ultrasonic waves. Some of these modes leak energy into the liquid filling the pipe or into the insulation covering the pipe, while others stay largely in the pipe wall and interact with flaws, including corrosion-induced defects. The success of the guided wave method as a viable NDE method for this application is critically dependent upon the ability to preferentially select the modes most sensitive to defects and exploit them for the information they carry about the existence, location, and geometry of corrosion-induced flaws. The feasibility of the guided wave approach for inspection of insulated pipe has been successfully demonstrated, and current work is aimed toward developing methods and systems capable of field inspection.

  9. Ultrasonically aided mineral processing technique for remediation of soil contaminated by heavy metals.

    PubMed

    Kyllönen, Hanna; Pirkonen, Pentti; Hintikka, Väinö; Parvinen, Pekka; Grönroos, Antti; Sekki, Hannu

    2004-05-01

    In this study, power ultrasound was used as aiding method for the mineral processing technique, which have recently been developed for the remediation of soil contaminated by heavy metal containing bullets, their broken parts and alteration products. Power ultrasound was used to disperse the soil to remove metals and metal compounds from soil particle surfaces instead of attrition conditioning. The soil diluted with water was treated using 22 kHz ultrasound power of 100 W up to 500 W. The effect of different ultrasonic treatment time and pulsation of ultrasound were studied on the purity of sink and float fractions in heavy medium separation process, screen fractions, and mineral concentrates and tailings from flotation process. Ultrasound enhanced the remediation of soil fractions in all the studied cases. Optimisation of the ultrasonic power will be done in the continuation study.

  10. Characterization of nonlinear ultrasonic effects using the dynamic wavelet fingerprint technique

    NASA Astrophysics Data System (ADS)

    Lv, Hongtao; Jiao, Jingpin; Meng, Xiangji; He, Cunfu; Wu, Bin

    2017-02-01

    An improved dynamic wavelet fingerprint (DWFP) technique was developed to characterize nonlinear ultrasonic effects. The white area in the fingerprint was used as the nonlinear feature to quantify the degree of damage. The performance of different wavelet functions, the effect of scale factor and white subslice ratio on the nonlinear feature extraction were investigated, and the optimal wavelet function, scale factor and white subslice ratio for maximum damage sensitivity were determined. The proposed DWFP method was applied to the analysis of experimental signals obtained from nonlinear ultrasonic harmonic and wave-mixing experiments. It was demonstrated that the proposed DWFP method can be used to effectively extract nonlinear features from the experimental signals. Moreover, the proposed nonlinear fingerprint coefficient was sensitive to micro cracks and correlated well with the degree of damage.

  11. Inspection of high-attenuation and high-noise materials using ultrasonic pulse compression technique

    SciTech Connect

    Jeong, P.

    1996-12-31

    Within a highly attenuating material, it is often difficult to identify relevant target signals due to the system`s white noise that is elevated by high gain settings on a conventional ultrasonic system. Ultrasonic pulse compression technique resolves such problem. The ultrasonic pulse compression technique permits an ultrasonic system to operate with long transmitted pulses for an increased detection range, but without sacrificing the depth resolution by signal correlation. The data contains 2048 points sampled at 40 nsec interval using 256 bits long and 100 nsec wide (single bit) Golay codes. Typical pulse compression systems transmit random or pseudorandom codes such as Barker code, maximal-length sequence, and linear FM chirp. And the configuration of such systems varies depending upon the type of code and its generation and processing methodology. However, such systems suffer from inherent limitation, called self noise or range sidelobes when finite integration time limits are used to approximate the signal correlation. To reduce the self noise to a tolerable level, Center for NDE, Iowa State University, has implemented a set of complementary binary codes, known as Golay codes, into a laboratory prototype pulse compression system. Golay code is a set of complementary series of the same length, each has its own auto-correlation having one main response, but the relative polarities are opposite except the main peak. So, if these two correlation results are added, the main response doubles and all others cancel. These characteristics of the Golay codes allow us to obtain a correlated signal of an enhanced SNR without the range sidelobe that is normally produced in other random or pseudorandom codes.

  12. Degree of dispersion monitoring by ultrasonic transmission technique and excitation of the transducer's harmonics

    NASA Astrophysics Data System (ADS)

    Schober, G.; Heidemeyer, P.; Kretschmer, K.; Bastian, M.; Hochrein, T.

    2014-05-01

    The degree of dispersion of filled polymer compounds is an important quality parameter for various applications. For instance, there is an influence on the chroma in pigment colored plastics or on the mechanical properties of filled or reinforced compounds. Most of the commonly used offline methods are work-intensive and time-consuming. Moreover, they do not allow an all-over process monitoring. In contrast, the ultrasonic technique represents a suitable robust and process-capable inline method. Here, we present inline ultrasonic measurements on polymer melts with a fundamental frequency of 1 MHz during compounding. In order to extend the frequency range we additionally excite the fundamental and the odd harmonics vibrations at 3 and 5 MHz. The measurements were carried out on a compound consisting of polypropylene and calcium carbonate. For the simulation of agglomerates calcium carbonate with a larger particle size was added with various rates. The total filler content was kept constant. The frequency selective analysis shows a linear correlation between the normalized extinction and the rate of agglomerates simulated by the coarser filler. Further experiments with different types of glass beads with a well-defined particle size verify these results. A clear correlation between the normalized extinction and the glass bead size as well as a higher damping with increasing frequency corresponds to the theoretical assumption. In summary the dispersion quality can be monitored inline by the ultrasonic technique. The excitation of the ultrasonic transducer's harmonics generates more information about the material as the usage of the pure harmonic vibration.

  13. Stresses in ultrasonically assisted bone cutting

    NASA Astrophysics Data System (ADS)

    Alam, K.; Mitrofanov, A. V.; Bäker, M.; Silberschmidt, V. V.

    2009-08-01

    Bone cutting is a frequently used procedure in the orthopaedic surgery. Modern cutting techniques, such as ultrasonic assisted drilling, enable surgeons to perform precision operations in facial and spinal surgeries. Advanced understanding of the mechanics of bone cutting assisted by ultrasonic vibration is required to minimise bone fractures and to optimise the technique performance. The paper presents results of finite element simulations on ultrasonic and conventional bone cutting analysing the effects of ultrasonic vibration on cutting forces and stress distribution. The developed model is used to study the effects of cutting and vibration parameters (e.g. amplitude and frequency) on the stress distributions in the cutting region.

  14. Advanced Tools and Techniques for Formal Techniques in Aerospace Systems

    NASA Technical Reports Server (NTRS)

    Knight, John C.

    2005-01-01

    This is the final technical report for grant number NAG-1-02101. The title of this grant was "Advanced Tools and Techniques for Formal Techniques In Aerospace Systems". The principal investigator on this grant was Dr. John C. Knight of the Computer Science Department, University of Virginia, Charlottesville, Virginia 22904-4740. This report summarizes activities under the grant during the period 7/01/2002 to 9/30/2004. This report is organized as follows. In section 2, the technical background of the grant is summarized. Section 3 lists accomplishments and section 4 lists students funded under the grant. In section 5, we present a list of presentations given at various academic and research institutions about the research conducted. Finally, a list of publications generated under this grant is included in section 6.

  15. Advanced techniques in echocardiography in small animals.

    PubMed

    Chetboul, Valérie

    2010-07-01

    Transthoracic echocardiography has become a major imaging tool for the diagnosis and management of canine and feline cardiovascular diseases. During the last decade, more recent advances in ultrasound technology with the introduction of newer imaging modalities, such as tissue Doppler imaging, strain and strain rate imaging, and 2-dimensional speckle tracking echocardiography, have provided new parameters to assess myocardial performance, including regional myocardial velocities and deformation, ventricular twist, and mechanical synchrony. An outline of these 4 recent ultrasound techniques, their impact on the understanding of right and left ventricular function in small animals, and their application in research and clinical settings are given in this article.

  16. Basic concepts of advanced MRI techniques.

    PubMed

    Pagani, Elisabetta; Bizzi, Alberto; Di Salle, Francesco; De Stefano, Nicola; Filippi, Massimo

    2008-10-01

    An overview is given of magnetic resonance (MR) techniques sensitized to diffusion, flow, magnetization transfer effect, and local field inhomogeneities induced by physiological changes, that can be viewed, in the clinical practice, as advanced because of their challenging implementation and interpretation. These techniques are known as diffusion-weighted, perfusion, magnetization transfer, functional MRI and MR spectroscopy. An important issue is that they can provide quantitative estimates of structural and functional characteristics that are below the voxel resolution. This review does not deal with the basic concepts of the MR physics and the description of the available acquisition and postprocessing methods, but hopefully provides an adequate background to readers and hence facilitate the understanding of the following clinical contributions.

  17. Non-destructive Detection of Small Blowholes in Aluminum by Using Laser Ultrasonics Technique

    NASA Astrophysics Data System (ADS)

    Sun, Kaihua; Shen, Zhonghua; Shi, Yifei; Xu, Zhihong; Yuan, Ling; Ni, Xiaowu

    2015-06-01

    In this paper, blowhole defects of sub-millimeter diameter in an aluminum alloy are successfully detected by the laser ultrasonic (LU) technique. A Q-switched and pulsed Nd:YAG laser is used for ultrasonic generation, and a laser Doppler vibration meter is used for detection of ultrasound waves on the sample surface. Through adding a thin and transparent film on the sample, a bulk wave penetrating method can be used for evaluating the position and size of the blowhole defects using the LU system. And the directivities of a longitudinal wave generated by a laser at different conditions are discussed. By two-dimensional moving of the sample with a precise motorized translation platform, the ultrasonic waves can be detected at different positions of the sample for evaluating the defects. The C-scan images were obtained to analyze the blowholes' position and size. Furthermore, a numerical simulation is also used to research the propagation properties of ultrasound in the specimen with internal holes. Results from the experiment and numerical simulation are discussed and compared to demonstrate the reliability and accuracy of the method.

  18. Advanced flow MRI: emerging techniques and applications.

    PubMed

    Markl, M; Schnell, S; Wu, C; Bollache, E; Jarvis, K; Barker, A J; Robinson, J D; Rigsby, C K

    2016-08-01

    Magnetic resonance imaging (MRI) techniques provide non-invasive and non-ionising methods for the highly accurate anatomical depiction of the heart and vessels throughout the cardiac cycle. In addition, the intrinsic sensitivity of MRI to motion offers the unique ability to acquire spatially registered blood flow simultaneously with the morphological data, within a single measurement. In clinical routine, flow MRI is typically accomplished using methods that resolve two spatial dimensions in individual planes and encode the time-resolved velocity in one principal direction, typically oriented perpendicular to the two-dimensional (2D) section. This review describes recently developed advanced MRI flow techniques, which allow for more comprehensive evaluation of blood flow characteristics, such as real-time flow imaging, 2D multiple-venc phase contrast MRI, four-dimensional (4D) flow MRI, quantification of complex haemodynamic properties, and highly accelerated flow imaging. Emerging techniques and novel applications are explored. In addition, applications of these new techniques for the improved evaluation of cardiovascular (aorta, pulmonary arteries, congenital heart disease, atrial fibrillation, coronary arteries) as well as cerebrovascular disease (intra-cranial arteries and veins) are presented.

  19. Ultrasonic, microwave, and millimeter wave inspection techniques for adhesively bonded stacked open honeycomb core composites

    NASA Astrophysics Data System (ADS)

    Thomson, Clint D.; Cox, Ian; Ghasr, Mohammad Tayeb Ahmed; Ying, Kuang P.; Zoughi, Reza

    2015-03-01

    Honeycomb sandwich composites are used extensively in the aerospace industry to provide stiffness and thickness to lightweight structures. A common fabrication method for thick, curved sandwich structures is to stack and bond multiple honeycomb layers prior to machining core curvatures. Once bonded, each adhesive layer must be inspected for delaminations and the presence of unwanted foreign materials. From a manufacturing and cost standpoint, it can be advantageous to inspect the open core prior to face sheet closeout in order to reduce end-article scrap rates. However, by nature, these honeycomb sandwich composite structures are primarily manufactured from low permittivity and low loss materials making detection of delamination and some of the foreign materials (which also are low permittivity and low loss) quite challenging in the microwave and millimeter wave regime. Likewise, foreign materials such as release film in adhesive layers can be sufficiently thin as to not cause significant attenuation in through-transmission ultrasonic signals, making them difficult to detect. This paper presents a collaborative effort intended to explore the efficacy of different non-contact NDI techniques for detecting flaws in a stacked open fiberglass honeycomb core panel. These techniques primarily included air-coupled through-transmission ultrasonics, single-sided wideband synthetic aperture microwave and millimeter-wave imaging, and lens-focused technique. The goal of this investigation has been to not only evaluate the efficacy of these techniques, but also to determine their unique advantages and limitations for evaluating parameters such as flaw type, flaw size, and flaw depth.

  20. Study on the Ring Type Stator Design Technique for a Traveling Wave Rotary Type Ultrasonic Motor

    NASA Astrophysics Data System (ADS)

    Oh, Jin-Heon; Yuk, Hyung-Sang; Lim, Kee-Joe

    2012-09-01

    In this paper, the technique of design for the stator of traveling wave rotary type ultrasonic motor was proposed. To establish the design technique, the distribution of internal stresses of the stator was analyzed by applying the cylindrical bodies contact model of Hertz theory and the concept of “horn effect” was used to consider the influence of the projection structure. To verify the proposed technique, the prototype motor was fabricated on the authority of the projection shape dimension and the design specification. And its performance was evaluated. According to the estimate production of the experiment results using the extrapolation, we confirmed that the values obtained through the verification experiment were similar to those deduced by the proposed method properly.

  1. Ultrasonic techniques for measuring physical properties of fluids in harsh environments

    NASA Astrophysics Data System (ADS)

    Pantea, Cristian

    Ultrasonic-based measurement techniques, either in the time domain or in the frequency domain, include a wide range of experimental methods for investigating physical properties of materials. This discussion is specifically focused on ultrasonic methods and instrumentation development for the determination of liquid properties at conditions typically found in subsurface environments (in the U.S., more than 80% of total energy needs are provided by subsurface energy sources). Such sensors require materials that can withstand harsh conditions of high pressure, high temperature and corrosiveness. These include the piezoelectric material, electrically conductive adhesives, sensor housings/enclosures, and the signal carrying cables, to name a few. A complete sensor package was developed for operation at high temperatures and pressures characteristic to geothermal/oil-industry reservoirs. This package is designed to provide real-time, simultaneous measurements of multiple physical parameters, such as temperature, pressure, salinity and sound speed. The basic principle for this sensor's operation is an ultrasonic frequency domain technique, combined with transducer resonance tracking. This multipurpose acoustic sensor can be used at depths of several thousand meters, temperatures up to 250 °C, and in a very corrosive environment. In the context of high precision measurement of sound speed, the determination of acoustic nonlinearity of liquids will also be discussed, using two different approaches: (i) the thermodynamic method, in which precise and accurate frequency domain sound speed measurements are performed at high pressure and high temperature, and (ii) a modified finite amplitude method, requiring time domain measurements of the second harmonic at room temperature. Efforts toward the development of an acoustic source of collimated low-frequency (10-150 kHz) beam, with applications in imaging, will also be presented.

  2. Microstructure and Mechanical Properties of Aluminum-Alumina Bulk Nanocomposite Produced by a Novel Two-Step Ultrasonic Casting Technique

    NASA Astrophysics Data System (ADS)

    Vishwanatha, H. M.; Eravelly, Jayakumar; Kumar, Cheruvu Siva; Ghosh, Sudipto

    2016-11-01

    An unprecedented uniform distribution of nano-dispersoids in aluminum-alumina bulk nanocomposite and enhancement in mechanical properties were achieved through a novel ultrasonic casting technique involving two-step ultrasonication. Ultrasonic casting can be classified into two types: (a) contact type, in which the sonicating probe is in direct contact with the liquid melt during ultrasonication and (b) non-contact type, in which the ultrasonic waves reach the liquid melt through the mold wall. Each of the processes has certain disadvantages, and the present study aims at eliminating the primary disadvantages of both the processes, through a novel two-step ultrasonic casting technique. The significant improvement in distribution was possibly due to the cavitation in the mold, leading to the elimination of non-uniformity in the cooling rate at the mesoscopic scale. The improvement in mechanical properties is explained through microstructure analysis in correlation with EBSD analysis, TEM analysis, hardness test, and tensile test. The yield strength of the nanocomposite produced by the two-step process was ~38 pct higher than that produced by non-contact and contact methods.

  3. Advanced Welding Concepts

    NASA Technical Reports Server (NTRS)

    Ding, Robert J.

    2010-01-01

    Four advanced welding techniques and their use in NASA are briefly reviewed in this poster presentation. The welding techniques reviewed are: Solid State Welding, Friction Stir Welding (FSW), Thermal Stir Welding (TSW) and Ultrasonic Stir Welding.

  4. Advanced techniques in current signature analysis

    NASA Astrophysics Data System (ADS)

    Smith, S. F.; Castleberry, K. N.

    1992-02-01

    In general, both ac and dc motors can be characterized as weakly nonlinear systems, in which both linear and nonlinear effects occur simultaneously. Fortunately, the nonlinearities are generally well behaved and understood and can be handled via several standard mathematical techniques already well developed in the systems modeling area; examples are piecewise linear approximations and Volterra series representations. Field measurements of numerous motors and motor-driven systems confirm the rather complex nature of motor current spectra and illustrate both linear and nonlinear effects (including line harmonics and modulation components). Although previous current signature analysis (CSA) work at Oak Ridge and other sites has principally focused on the modulation mechanisms and detection methods (AM, PM, and FM), more recent studies have been conducted on linear spectral components (those appearing in the electric current at their actual frequencies and not as modulation sidebands). For example, large axial-flow compressors (approximately 3300 hp) in the US gaseous diffusion uranium enrichment plants exhibit running-speed (approximately 20 Hz) and high-frequency vibrational information (greater than 1 kHz) in their motor current spectra. Several signal-processing techniques developed to facilitate analysis of these components, including specialized filtering schemes, are presented. Finally, concepts for the designs of advanced digitally based CSA units are offered, which should serve to foster the development of much more computationally capable 'smart' CSA instrumentation in the next several years.

  5. Development of an ultrasonic pulse-echo (UPE) technique for aircraft icing studies

    NASA Astrophysics Data System (ADS)

    Liu, Yang; Chen, Wen-Li; Bond, Leonard J.; Hu, Hui

    2014-02-01

    Aircraft operating in some cold weather conditions face the risk of icing. Icing poses a threat to flight safety and its management is expensive. Removing light frost on a clear day from a medium-size business jet can cost 300, heavy wet snow removal can cost 3,000 and removal of accumulated frozen/freezing rain can cost close to 10,000. Understanding conditions that lead to severe icing events is important and challenging. When an aircraft or rotorcraft flies in a cold climate, some of the super cooled droplets impinging on exposed aircraft surfaces may flow along the surface prior to freezing and give various forms and shapes of ice. The runback behavior of a water film on an aircraft affects the morphology of ice accretion and the rate of formation. In this study, we report the recent progress to develop an Ultrasonic Pulse-Echo (UPE) technique to provide real-time thickness distribution measurements of surface water flows driven by boundary layer airflows for aircraft icing studies. A series of initial experimental investigations are conducted in an ice wind tunnel employing an array of ultrasonic transducers placed underneath the surface of a flat plate. The water runback behavior on the plate is evaluated by measuring the thickness profile variation of the water film along the surface by using the UPE technique under various wind speed and flow rate conditions.

  6. Development of an ultrasonic pulse-echo (UPE) technique for aircraft icing studies

    SciTech Connect

    Liu, Yang; Hu, Hui; Chen, Wen-Li; Bond, Leonard J.

    2014-02-18

    Aircraft operating in some cold weather conditions face the risk of icing. Icing poses a threat to flight safety and its management is expensive. Removing light frost on a clear day from a medium-size business jet can cost $300, heavy wet snow removal can cost $3,000 and removal of accumulated frozen/freezing rain can cost close to $10,000. Understanding conditions that lead to severe icing events is important and challenging. When an aircraft or rotorcraft flies in a cold climate, some of the super cooled droplets impinging on exposed aircraft surfaces may flow along the surface prior to freezing and give various forms and shapes of ice. The runback behavior of a water film on an aircraft affects the morphology of ice accretion and the rate of formation. In this study, we report the recent progress to develop an Ultrasonic Pulse-Echo (UPE) technique to provide real-time thickness distribution measurements of surface water flows driven by boundary layer airflows for aircraft icing studies. A series of initial experimental investigations are conducted in an ice wind tunnel employing an array of ultrasonic transducers placed underneath the surface of a flat plate. The water runback behavior on the plate is evaluated by measuring the thickness profile variation of the water film along the surface by using the UPE technique under various wind speed and flow rate conditions.

  7. NONDESTRUCTIVE DETECTION OF DELAMINATION IN THERMAL BARRIER COATINGS USING ULTRASONIC TECHNIQUE

    SciTech Connect

    Chen, Roger H. L.; Zhang, Binwei; Alvin, Mary Anne

    2009-06-12

    Nondestructive testing using an acousto-ultrasonic technique has been utilized to detect the change of material properties and provide early warning of failure of thermal barrier coating (TBC) systems. Testing was performed on René N5 and Haynes 230 coupons with an applied NETL-bond coat, as well as on coupons containing both an applied MCrAlY bond coat and 7-YSZ top coat. The coupons were subjected to either cyclic or isothermal testing at 1100ºC. Ultrasonic testing was performed before and after thermal testing using piezoelectric sensors with dry contact on the surface of the coatings. Proof-of-concept test results indicated that changes in the properties of the 40m bond coat can be detected using the proposed technique. Waveforms generated via Pitch/Catch indicated minor changes within the bond coat applied to René N5 substrate after 400500 hours of cyclic oxidation at 1100°C. In contrast, marked differences in waveforms and travel time reflected significant crack formation and spallation of the bond coat from the Haynes 230 substrate. Finite element analysis (FEA) simulation of the wave propagation on a simplified TBC system with nonlinear effects was conducted. FEA results clearly show detection of a small embedded void incorporated to simulate delamination. Comparisons between experimental measurements and finite element simulations were used to estimate the material properties of the coatings and the substrate.

  8. Assessment of Crack Detection in Heavy-Walled Cast Stainless Steel Piping Welds Using Advanced Low-Frequency Ultrasonic Methods

    SciTech Connect

    Anderson, Michael T.; Crawford, Susan L.; Cumblidge, Stephen E.; Denslow, Kayte M.; Diaz, Aaron A.; Doctor, Steven R.

    2007-03-01

    Studies conducted at the Pacific Northwest National Laboratory in Richland, Washington, have focused on assessing the effectiveness and reliability of novel approaches to nondestructive examination (NDE) for inspecting coarse-grained, cast stainless steel reactor components. The primary objective of this work is to provide information to the U.S. Nuclear Regulatory Commission on the effectiveness and reliability of advanced NDE methods as related to the inservice inspection of safety-related components in pressurized water reactors (PWRs). This report provides progress, recent developments, and results from an assessment of low frequency ultrasonic testing (UT) for detection of inside surface-breaking cracks in cast stainless steel reactor piping weldments as applied from the outside surface of the components. Vintage centrifugally cast stainless steel piping segments were examined to assess the capability of low-frequency UT to adequately penetrate challenging microstructures and determine acoustic propagation limitations or conditions that may interfere with reliable flaw detection. In addition, welded specimens containing mechanical and thermal fatigue cracks were examined. The specimens were fabricated using vintage centrifugally cast and statically cast stainless steel materials, which are typical of configurations installed in PWR primary coolant circuits. Ultrasonic studies on the vintage centrifugally cast stainless steel piping segments were conducted with a 400-kHz synthetic aperture focusing technique and phased array technology applied at 500 kHz, 750 kHz, and 1.0 MHz. Flaw detection and characterization on the welded specimens was performed with the phased array method operating at the frequencies stated above. This report documents the methodologies used and provides results from laboratory studies to assess baseline material noise, crack detection, and length-sizing capability for low-frequency UT in cast stainless steel piping.

  9. Microleakage Evaluation Around Retrograde Filling Materials Prepared Using Conventional and Ultrasonic Techniques

    PubMed Central

    Bolla, Nagesh; Thumu, Jayaprakash; Vemuri, Sayesh; Chukka, Sunil

    2015-01-01

    Introduction: The importance of the retrograde cavity preparation and the material used to restore is of utmost importance to achieve successful surgical endodontics. Aim: The aim of the present study is to evaluate the apical micro-leakage of root end cavities filled with Mineral trioxide aggregate, Biodentine and light cure GIC using two different cavity preparation techniques that is conventional bur preparation and ultrasonic tip preparation. Materials and Methods: Eighty extracted single rooted human teeth (except mandibular incisors) with one canal, fully developed apices and without any major carious lesion are collected for the study. The teeth were sectioned at CEJ to standardize the length. Roots are instrumented upto master apical file 40 K size and obturated with gutta percha and AH plus sealer in lateral condensation technique. The teeth were then resected apically at 90° angle axis to the long axis of the root removing 3 mm of the apex. The teeth were divided in to four groups of 20 each- • Group I- samples restored with MTA. • Group II- samples restored with Biodentine. • Group III- (Positive control group)- samples restored with Light activated GIC. • Group IV - (negative control group)- no filling material. Each group is divided into two subgroups (a, b) of ten teeth each 1. Retropreparation done with ultrasonic retrotip. 2. Retropreparation done with conventional bur. The teeth were then immersed in 0.5% Rhodamine B dye for 48 h. The teeth were split longitudinally and the interface between the restored material and the canal wall is observed under Confocal laser scanning microscope. Depth of dye penetration was examined under stereomicroscope. Results: The statistical analysis was performed by One way ANOVA, t test. Pair wise comparision was done by Newman – Keuls multiple post hoc test. The mean values of Dye penetration for Group Ia (321.23), Group Ib (490.11), Group IIa (1065.14), Group IIb (1170.96), Group IIIa (1888.90), Group

  10. Transformation of eutectic emulsion to nanosuspension fabricating with solvent evaporation and ultrasonication technique

    PubMed Central

    Phaechamud, Thawatchai; Tuntarawongsa, Sarun

    2016-01-01

    Eutectic solvent can solubilize high amount of some therapeutic compounds. Volatile eutectic solvent is interesting to be used as solvent in the preparation of nanosuspension with emulsion solvent evaporation technique. The mechanism of transformation from the eutectic emulsion to nanosuspension was investigated in this study. The 30% w/w ibuprofen eutectic solution was used as the internal phase, and the external phase is composed of Tween 80 as emulsifier. Ibuprofen nanosuspension was prepared by eutectic emulsion solvent evaporating method followed with ultrasonication. During evaporation process, the ibuprofen concentration in emulsion droplets was increased leading to a drug supersaturation but did not immediately recrystallize because of low glass transition temperature (Tg) of ibuprofen. The contact angle of the internal phase on ibuprofen was apparently lower than that of the external phase at all times of evaporation, indicating that the ibuprofen crystals were preferentially wetted by the internal phase than the external phase. From calculated dewetting value ibuprofen crystallization occurred in the droplet. Crystallization of the drug was initiated with external mechanical force, and the particle size of the drug was larger due to Ostwald ripening. Cavitation force from ultrasonication minimized the ibuprofen crystals to the nanoscale. Particle size and zeta potential of formulated ibuprofen nanosuspension were 330.87±51.49 nm and −31.1±1.6 mV, respectively, and exhibited a fast dissolution. Therefore, the combination of eutectic emulsion solvent evaporation method with ultrasonication was favorable for fabricating an ibuprofen nanosuspension, and the transformation mechanism was attained successfully. PMID:27366064

  11. Transformation of eutectic emulsion to nanosuspension fabricating with solvent evaporation and ultrasonication technique.

    PubMed

    Phaechamud, Thawatchai; Tuntarawongsa, Sarun

    2016-01-01

    Eutectic solvent can solubilize high amount of some therapeutic compounds. Volatile eutectic solvent is interesting to be used as solvent in the preparation of nanosuspension with emulsion solvent evaporation technique. The mechanism of transformation from the eutectic emulsion to nanosuspension was investigated in this study. The 30% w/w ibuprofen eutectic solution was used as the internal phase, and the external phase is composed of Tween 80 as emulsifier. Ibuprofen nanosuspension was prepared by eutectic emulsion solvent evaporating method followed with ultrasonication. During evaporation process, the ibuprofen concentration in emulsion droplets was increased leading to a drug supersaturation but did not immediately recrystallize because of low glass transition temperature (T g) of ibuprofen. The contact angle of the internal phase on ibuprofen was apparently lower than that of the external phase at all times of evaporation, indicating that the ibuprofen crystals were preferentially wetted by the internal phase than the external phase. From calculated dewetting value ibuprofen crystallization occurred in the droplet. Crystallization of the drug was initiated with external mechanical force, and the particle size of the drug was larger due to Ostwald ripening. Cavitation force from ultrasonication minimized the ibuprofen crystals to the nanoscale. Particle size and zeta potential of formulated ibuprofen nanosuspension were 330.87±51.49 nm and -31.1±1.6 mV, respectively, and exhibited a fast dissolution. Therefore, the combination of eutectic emulsion solvent evaporation method with ultrasonication was favorable for fabricating an ibuprofen nanosuspension, and the transformation mechanism was attained successfully.

  12. Correlation-based imaging technique using ultrasonic transmit-receive array for Non-Destructive Evaluation.

    PubMed

    Quaegebeur, Nicolas; Masson, Patrice

    2012-12-01

    This paper describes a novel array post-processing method for Non-Destructive Evaluation (NDE) using phased-array ultrasonic probes. The approach uses the capture and processing of the full matrix of all transmit-receive time-domain signals from a transducer array as in the case of the Total Focusing Method (TFM), referred as the standard of imaging algorithms. The proposed technique is based on correlation of measured signals with theoretical propagated signals computed over a given grid of points. In that case, real-time imaging can be simply implemented using discrete signal product. The advantage of the present technique is to take into account transducer directivity, dynamics and complex propagation patterns, such that the number of required array elements for a given imaging performance can be greatly reduced. Numerical and experimental application to contact inspection of isotropic structure is presented and real-time implementation issues are discussed.

  13. Phased array ultrasonic testing of dissimilar metal welds using geometric based referencing delay law technique

    NASA Astrophysics Data System (ADS)

    Han, Taeyoung; Schubert, Frank; Hillmann, Susanne; Meyendorf, Norbert

    2015-03-01

    Phased array ultrasonic testing (PAUT) techniques are widely used for the non-destructive testing (NDT) of austenitic welds to find defects like cracks. However, the propagation of ultrasound waves through the austenitic material is intricate due to its inhomogeneous and anisotropic nature. Such a characteristic leads beam path distorted which causes the signal to be misinterpreted. By employing a reference block which is cutout from the mockup of which the structure is a dissimilar metal weld (DMW), a new method of PAUT named as Referencing Delay Law Technique (RDLT) is introduced. With the RDLT, full matrix capture (FMC) was used for data acquisition. To reconstruct the images, total focusing method (TFM) was used. After the focal laws were calculated, PAUT was then performed. As a result, the flaws are more precisely positioned with significantly increased signal-to-noise ratio (SNR).

  14. NONINVASIVE, NONCONTACT FLUID DETECTION IN SUBMERGED CONTAINERS USING SWEPT FREQUENCY ULTRASONIC TECHNIQUE.

    SciTech Connect

    Los Alamos National Laboratory

    2001-01-01

    A noncontact technique has been developed for the remote interrogation of submerged and limited access metal containers for determining the presence of fluid inside, The technique is based on the damping effect of water on the thickness mode resonance of the container wall. A transmitter-receiver pair of piezoelectric transducers is placed at a standoff distance of 5 mm from the container wall with the water outside the container providing ultrasonic coupling medium. The excitation frequency applied to the transmitter is swept between 0.8-4.0M Hz and the receiver transducer detects the signal, in the form of a frequency spectrum, returned from the wall. By analyzing the variation in the observed spectrum, it is straightforward to determine whether the container is fluid or air backed thereby detecting if the container has leaked.

  15. Intracranial pressure dynamics during simulated microgravity using a new noninvasive ultrasonic technique

    NASA Technical Reports Server (NTRS)

    Ueno, T.; Ballard, R. E.; Shuer, L. M.; Yost, W. T.; Cantrell, J. H.; Hargens, A. R.

    1998-01-01

    It is believed that intracranial pressure (ICP) may be elevated in microgravity because a fluid shift toward the head occurs due to loss of gravitational blood pressures. Elevated ICP may contribute to space adaptation syndrome, because as widely observed in clinical settings, elevated ICP causes headache, nausea, and projectile vomiting, which are similar to symptoms of space adaptation syndrome. However, the hypothesis that ICP is altered in microgravity is difficult to test because of the invasiveness of currently-available techniques. We have developed a new ultrasonic technique, which allows us to record ICP waveforms noninvasively. The present study was designed to understand postural effects on ICP and assess the feasibility of our new device in future flight experiments.

  16. Automatic ultrasonic imaging system with adaptive-learning-network signal-processing techniques

    SciTech Connect

    O'Brien, L.J.; Aravanis, N.A.; Gouge, J.R. Jr.; Mucciardi, A.N.; Lemon, D.K.; Skorpik, J.R.

    1982-04-01

    A conventional pulse-echo imaging system has been modified to operate with a linear ultrasonic array and associated digital electronics to collect data from a series of defects fabricated in aircraft quality steel blocks. A thorough analysis of the defect responses recorded with this modified system has shown that considerable improvements over conventional imaging approaches can be obtained in the crucial areas of defect detection and characterization. A combination of advanced signal processing concepts with the Adaptive Learning Network (ALN) methodology forms the basis for these improvements. Use of established signal processing algorithms such as temporal and spatial beam-forming in concert with a sophisticated detector has provided a reliable defect detection scheme which can be implemented in a microprocessor-based system to operate in an automatic mode.

  17. Physical interpretation and development of ultrasonic nondestructive evaluation techniques applied to the quantitative characterization of textile composite materials

    NASA Technical Reports Server (NTRS)

    Miller, James G.

    1992-01-01

    The development and implementation of advanced ultrasonic nondestructive evaluation methods applied to the characterization of composite materials requires a better understanding of the physics underlying the interaction of ultrasound with the material. The purpose of this investigation is to identify and characterize the features of complex, three dimensional materials that limit the ability of ultrasound to detect flaws in this broad class of emerging materials. In order to explore the interaction of ultrasound with such complex media, we investigate the characteristics of ultrasonic fields which have propagated through samples with complex geometries and/or internal architecture. We focus on the physics that underlies the detection of flaws in such materials.

  18. Program for field validation of the Synthetic Aperture Focusing Technique for Ultrasonic Testing (SAFT UT)

    NASA Astrophysics Data System (ADS)

    Hamlin, D. R.

    1985-11-01

    This final report describes work performed by Southwest Research Institute for the Nuclear Regulatory Commission (NRC) in fulfillment of NRC Contract No. NRC-04-77-145; "Program for Field Validation of the Synthetic Aperture Focusing Technique for Ultrasonic Testing (SAFT UT)." The purpose was to validate the effectiveness of SAFT UT as a nondestructive examination technique for nuclear power and other related industries. SAFT UT is an ultrasonic imaging method for accurate measurement of the spatial location and extent of acoustically reflective surfaces (flaws) contained in objects such as structural components and weldments in nuclear power reactor systems. The increased measurement accuracy offered by SAFT, when compared with that provided by measurement methods now in use, will improve the reliability of flaw severity assessment with resultant safety and economic benefits to the nuclear power industry. This report presents a comprehensive discussion of the work accomplished in evaluating the performance capabilities of the developed SAFT UT inspection system. Inspection results obtained using both 0-degree longitudinal and angle-beam operating modes are presented. These results include laboratory and nuclear power plant field site examinations on a variety of defect types contained within carbon and stainless steel flat plate and cylindrical test specimens or components. The SAFT UT processed data flaw images are evaluated by comparing them to results obtained from destructive sectioning or by using flaw fabrication data which predicted actual flaw depth, orientation and size. On the basis of these evaluations, conclusions are presented which summarize the performance capabilities of the SAFT UT inspection technique.

  19. Physical interpretation and development of ultrasonic nondestructive evaluation techniques applied to the quantitative characterization of textile composite materials

    NASA Technical Reports Server (NTRS)

    Miller, James G.

    1993-01-01

    In this Progress Report, we describe our current research activities concerning the development and implementation of advanced ultrasonic nondestructive evaluation methods applied to the characterization of stitched composite materials and bonded aluminum plate specimens. One purpose of this investigation is to identify and characterize specific features of polar backscatter interrogation which enhance the ability of ultrasound to detect flaws in a stitched composite laminate. Another focus is to explore the feasibility of implementing medical linear array imaging technology as a viable ultrasonic-based nondestructive evaluation method to inspect and characterize bonded aluminum lap joints. As an approach to implementing quantitative ultrasonic inspection methods to both of these materials, we focus on the physics that underlies the detection of flaws in such materials.

  20. NDE of additively manufactured components with embedded defects (reference standards) using conventional and advanced ultrasonic methods

    NASA Astrophysics Data System (ADS)

    Koester, L.; Roberts, R. A.; Barnard, D. J.; Chakrapani, S.; Singh, S.; Hogan, R.; Bond, L. J.

    2017-02-01

    Additive manufacturing provides a unique opportunity to embed defects of known size and shape to produce reference samples for inspection and quality control purposes. This paper reports defect detectability studies with cylindrical additively manufactured cobalt-chromium alloy specimens which contain defects of known sizes and distributions. The specimens were characterized using immersion, synthetic aperture focusing (SAFT), phased array, and nonlinear ultrasonic techniques. Results include detectability, signal to noise ratios, and comparison of results between the methods and what is believed to be the first determination of a non-linearity (beta) parameter for an additively manufactured material. The results indicate that additive manufacturing provides a valuable method to produce reference samples, though additional work is required to validate the shape and morphology of the defects specified.

  1. Enhanced ultrasonic characterization of assemblies, TLL_19

    SciTech Connect

    Chinn, D; Thomas, G

    1998-09-01

    Bonded joints, such as the autoclave bond, are critical to the performance of weapon systems. A nondestructive method to assess the integrity of these bonds is needed to certify the weapon for extended life. This project is developing ultrasonic technologies for bond quality assessment. Existing ultrasonic technology easily maps totally unbonded areas in a bond line but does not measure the quality of the bond. We are extracting information from the ultrasonic signals to quantify the mechanical. properties and assess the durability of the bond. Our approach is based on advanced signal processing and artificial intelligence techniques that process information from the ultrasonic signal after it interacts with the bondline. Computer algorithms recognize variations in bond quality from the acoustic signals. The ultrasonic signal processing and bond classification software will be installed on ultrasonic scanners at the appropriate sites.

  2. Integrated ultrasonic transducers made by the sol gel spray technique for structural health monitoring

    NASA Astrophysics Data System (ADS)

    Kobayashi, M.; Jen, C.-K.; Moisan, J.-F.; Mrad, N.; Nguyen, S. B.

    2007-04-01

    Integrated piezoelectric-based ultrasonic transducers (UTs) have been developed for potential structural health monitoring. Fabrication techniques and performance evaluation of these transducers at selected monitoring sites are presented. Our novel transducer fabrication approach focuses on the use of handheld and readily accessible equipment to perform sol-gel spray coating, including the use of a heat gun or a torch, to carry out drying and firing, poling and electrode fabrication. The application of these integrated UTs for thickness measurement of graphite/epoxy composites, thickness monitoring of ice build up on aluminum plates at low temperatures, viscosity measurement of a cooling oil flow at temperatures up to 160 °C and monitoring metal debris in cooling oil engines is demonstrated.

  3. An Enhanced Technique for Ultrasonic Flow Metering Featuring Very Low Jitter and Offset

    PubMed Central

    Hamouda, Assia; Manck, Otto; Hafiane, Mohamed Lamine; Bouguechal, Nour-Eddine

    2016-01-01

    This paper proposes a new, improved method for water flow metering. It applies to a transit time ultrasonic flow meter device. In principle, the flow of a given liquid in a pipe is obtained by measuring the transit times of an ultrasonic wave in the upstream and downstream directions. The difference between these times is, in theory, linearly proportional to the liquid flow velocity. However, the fainter the flow is, the smaller the transit time difference (TTD) is. This difference can be as low as a few picoseconds, which gives rise to many technical difficulties in measuring such a small time difference with a given accuracy. The proposed method relies on measuring the TTD indirectly by computing the phase difference between the steady-state parts of the received signals in the upstream and downstream directions and by using a least-square-sine-fitting technique. This reduces the effect of the jitter noise and the offset, which limit measurement precision at very low flow velocity. The obtained measurement results illustrate the robustness of the proposed method, as we measure the TTD at no-flow conditions, with a precision as low as 10 ps peak-to-peak and a TTD offset of zero, within a temperature range from room temperature to 80 °C. This allows us to reach a smaller minimum detectable flow when compared with previous techniques. The proposed method exhibits a better trade-off between measurement accuracy and system complexity. It can be completely integrated in an ASIC (application specific integrated circuit) or incorporated in a CPU- or micro-controller-based system. PMID:27367701

  4. Use of an ultrasonic reflectance technique to examine bubble size changes in dough

    NASA Astrophysics Data System (ADS)

    Strybulevych, A.; Leroy, V.; Shum, A. L.; Koksel, H. F.; Scanlon, M. G.; Page, J. H.

    2012-12-01

    Bread quality largely depends on the manner in which bubbles are created and manipulated in the dough during processing. We have developed an ultrasonic reflectance technique to monitor bubbles in dough, even at high volume fractions, where near the bubble resonances it is difficult to make measurements using transmission techniques. A broadband transducer centred at 3.5 MHz in a normal incidence wave reflection set-up is used to measure longitudinal velocity and attenuation from acoustic impedance measurements. The technique is illustrated by examining changes in bubbles in dough due to two very different physical effects. In dough made without yeast, a peak in attenuation due to bubble resonance is observed at approximately 2 MHz. This peak diminishes rapidly and shifts to lower frequencies, indicative of Ostwald ripening of bubbles within the dough. The second effect involves the growth of bubble sizes due to gas generated by yeast during fermentation. This process is experimentally challenging to investigate with ultrasound because of very high attenuation. The reflectance technique allows the changes of the velocity and attenuation during fermentation to be measured as a function of frequency and time, indicating bubble growth effects that can be monitored even at high volume fractions of bubbles.

  5. Ultrasonic Interferometers Revisited

    ERIC Educational Resources Information Center

    Greenslade, Thomas B., Jr.

    2007-01-01

    I have been tinkering with ultrasonic transducers once more. In earlier notes I reported on optics-like experiments performed with ultrasonics, described a number of ultrasonic interferometers, and showed how ultrasonic transducers can be used for Fourier analysis. This time I became interested in trying the technique of using two detectors in…

  6. Nuclear Technology. Course 32: Nondestructive Examination (NDE) Techniques II. Module 32-2, Operation of Ultrasonic Test Equipment.

    ERIC Educational Resources Information Center

    Espy, John

    This second in a series of six modules for a course titled Nondestructive Examination (NDE) II describes specific ultrasonic test techniques and calibration principles. The module follows a typical format that includes the following sections: (1) introduction, (2) module prerequisites, (3) objectives, (4) notes to instructor/student, (5) subject…

  7. Advanced Recording and Preprocessing of Physiological Signals. [data processing equipment for flow measurement of blood flow by ultrasonics

    NASA Technical Reports Server (NTRS)

    Bentley, P. B.

    1975-01-01

    The measurement of the volume flow-rate of blood in an artery or vein requires both an estimate of the flow velocity and its spatial distribution and the corresponding cross-sectional area. Transcutaneous measurements of these parameters can be performed using ultrasonic techniques that are analogous to the measurement of moving objects by use of a radar. Modern digital data recording and preprocessing methods were applied to the measurement of blood-flow velocity by means of the CW Doppler ultrasonic technique. Only the average flow velocity was measured and no distribution or size information was obtained. Evaluations of current flowmeter design and performance, ultrasonic transducer fabrication methods, and other related items are given. The main thrust was the development of effective data-handling and processing methods by application of modern digital techniques. The evaluation resulted in useful improvements in both the flowmeter instrumentation and the ultrasonic transducers. Effective digital processing algorithms that provided enhanced blood-flow measurement accuracy and sensitivity were developed. Block diagrams illustrative of the equipment setup are included.

  8. Surgical Efficacy Among Laparoscopic Ultrasonic Dissectors: Are We Advancing Safely? A Review of Literature.

    PubMed

    Devassy, Rajesh; Gopalakrishnan, Sreelatha; De Wilde, Rudy Leon

    2015-10-01

    The specialty of laparoscopy has evolved with the advent of new technologies over the last few years. Energy-based devices and Ultrasonic dissectors are used with a lot of factors in play-including ergonomics and economics during surgery. Here an attempt is based to review the surgical efficacy and safety of these dissectors with importance to plume production and lateral thermal damage. The factors contributing to adversities to the dissectors are also to be noted. The strategy adopted was aimed at finding relevant studies from PubMed from 1995 to 2014. The basic principle of plume production and thermal damage are studied in this review. Factors contributing to the same that can lead to adversities during laparoscopic surgeries are identified. Summarizing key points that increase lateral thermal damage and plume production amongst different ultrasonic shears and suggesting a technique to identify the right balance between the existing dissectors was possible. The RF Device and USS are both useful and widely used and are more safer than monopolar devices. RF Device is considerably slower than USS, as it cannot achieve coagulation and cutting at the same time. Although USS definitely improvises dissection and has less thermal injury than RF Device, the clinical implications in balancing dissection efficacy with hemostasis need to be investigated further. The ideal haemostatic energy-based shear device would be one with excellent hemostatic results and visual acuity while allowing none or minimal thermal energy escape at the point of application. In our current setting, a combined use of both RF and USS device usage as applied in the particular situations has potential.

  9. Bringing Advanced Computational Techniques to Energy Research

    SciTech Connect

    Mitchell, Julie C

    2012-11-17

    Please find attached our final technical report for the BACTER Institute award. BACTER was created as a graduate and postdoctoral training program for the advancement of computational biology applied to questions of relevance to bioenergy research.

  10. Noninvasive Measurement of Acoustic Properties of Fluids Using Ultrasonic Interferometry Technique

    SciTech Connect

    Han, W.; Sinha, D.N.; Springer, K.N.; Lizon, D.C.

    1997-06-15

    A swept-frequency ultrasonic interferometry technique is used for noninvasively determining acoustic properties of fluids inside containers. Measurements over a frequency range 1-15 MHz on six liquid chemicals are presented. Measurements were made with the liquid inside standard rectangular optical glass cells and stainless steel cylindrical shells. A theoretical model based on one-dimensional planar acoustic wave propagation through multi-layered media is employed for the interpretation of the observed resonance (interference) spectrum. Two analytical methods, derived from the transmission model are used for determination of sound speed, sound attenuation coefficient, and density of liquids from the relative amplitude and half-power peak width of the observed resonance peaks. Effects of the container material and geometrical properties, path-length, wall thickness are also studied. This study shows that the interferometry technique and the experimental method developed are capable of accurate determination of sound speed, sound attenuation, and density in fluids completely noninvasively. It is a capable and versatile fluid characterization technique and has many potential NDE applications.

  11. High precision ultrasonic guided wave technique for inspection of power transmission line

    NASA Astrophysics Data System (ADS)

    Cheng, Jun; Qiu, Jinhao; Ji, Hongli; Wang, Enrong; Takagi, Toshiyuki; Uchimoto, Tetsuya

    2017-01-01

    Due to the merits of high inspection speed and long detecting distance, Ultrasonic Guided Wave(UGW) method has been commonly applied to the on-line maintenance of power transmission line. However, the guided wave propagation in this structure is very complicated, leading to the unfavorable defect localization accuracy. Aiming at this situation, a high precision UGW technique for inspection of local surface defect in power transmission line is proposed. The technique is realized by adopting a novel segmental piezoelectric ring transducer and transducer mounting scheme, combining with the comprehensive characterization of wave propagation and circumferential defect positioning with multiple piezoelectric elements. Firstly, the propagation path of guided waves in the multi-wires of transmission line under the proposed technique condition is investigated experimentally. Next, the wave velocities are calculated by dispersion curves and experiment test respectively, and from comparing of the two results, the guided wave mode propagated in transmission line is confirmed to be F(1,1) mode. Finally, the axial and circumferential positioning of local defective wires in transmission line are both achieved, by using multiple piezoelectric elements to surround the stands and send elastic waves into every single wire. The proposed research can play a role of guiding the development of highly effective UGW method and detecting system for multi-wire transmission line.

  12. Irradiation Testing of Ultrasonic Transducers

    SciTech Connect

    Daw, Joshua; Tittmann, Bernhard; Reinhardt, Brian; Kohse, Gordon E.; Ramuhalli, Pradeep; Montgomery, Robert O.; Chien, Hual-Te; Villard, Jean-Francois; Palmer, Joe; Rempe, Joy

    2014-07-30

    Ultrasonic technologies offer the potential for high accuracy and resolution in-pile measurement of a range of parameters, including geometry changes, temperature, crack initiation and growth, gas pressure and composition, and microstructural changes. Many Department of Energy-Office of Nuclear Energy (DOE-NE) programs are exploring the use of ultrasonic technologies to provide enhanced sensors for in-pile instrumentation during irradiation testing. For example, the ability of single, small diameter ultrasonic thermometers (UTs) to provide a temperature profile in candidate metallic and oxide fuel would provide much needed data for validating new fuel performance models. Other efforts include an ultrasonic technique to detect morphology changes (such as crack initiation and growth) and acoustic techniques to evaluate fission gas composition and pressure. These efforts are limited by the lack of existing knowledge of ultrasonic transducer material survivability under irradiation conditions. For this reason, the Pennsylvania State University (PSU) was awarded an Advanced Test Reactor National Scientific User Facility (ATR NSUF) project to evaluate promising magnetostrictive and piezoelectric transducer performance in the Massachusetts Institute of Technology Research Reactor (MITR) up to a fast fluence of at least 1021 n/cm2 (E> 0.1 MeV). The goal of this research is to characterize magnetostrictive and piezoelectric transducer survivability during irradiation, enabling the development of novel radiation tolerant ultrasonic sensors for use in Material and Test Reactors (MTRs). As such, this test will be an instrumented lead test and real-time transducer performance data will be collected along with temperature and neutron and gamma flux data. The current work bridges the gap between proven out-of-pile ultrasonic techniques and in-pile deployment of ultrasonic sensors by acquiring the data necessary to demonstrate the performance of ultrasonic transducers.

  13. Irradiation Testing of Ultrasonic Transducers

    SciTech Connect

    Daw, Joshua; Tittmann, Bernhard; Reinhardt, Brian; Kohse, Gordon E.; Ramuhalli, Pradeep; Montgomery, Robert O.; Chien, Hual-Te; Villard, Jean-Francois; Palmer, Joe; Rempe, Joy

    2013-12-01

    Ultrasonic technologies offer the potential for high accuracy and resolution in-pile measurement of a range of parameters, including geometry changes, temperature, crack initiation and growth, gas pressure and composition, and microstructural changes. Many Department of Energy-Office of Nuclear Energy (DOE-NE) programs are exploring the use of ultrasonic technologies to provide enhanced sensors for in-pile instrumentation during irradiation testing. For example, the ability of single, small diameter ultrasonic thermometers (UTs) to provide a temperature profile in candidate metallic and oxide fuel would provide much needed data for validating new fuel performance models. Other efforts include an ultrasonic technique to detect morphology changes (such as crack initiation and growth) and acoustic techniques to evaluate fission gas composition and pressure. These efforts are limited by the lack of existing knowledge of ultrasonic transducer material survivability under irradiation conditions. For this reason, the Pennsylvania State University (PSU) was awarded an Advanced Test Reactor National Scientific User Facility (ATR NSUF) project to evaluate promising magnetostrictive and piezoelectric transducer performance in the Massachusetts Institute of Technology Research Reactor (MITR) up to a fast fluence of at least 1021 n/cm2 (E> 0.1 MeV). The goal of this research is to characterize magnetostrictive and piezoelectric transducer survivability during irradiation, enabling the development of novel radiation tolerant ultrasonic sensors for use in Material and Test Reactors (MTRs). As such, this test will be an instrumented lead test and real-time transducer performance data will be collected along with temperature and neutron and gamma flux data. The current work bridges the gap between proven out-of-pile ultrasonic techniques and in-pile deployment of ultrasonic sensors by acquiring the data necessary to demonstrate the performance of ultrasonic transducers.

  14. Nonlinear Ultrasonic Techniques to Monitor Radiation Damage in RPV and Internal Components

    SciTech Connect

    Jacobs, Laurence; Kim, Jin-Yeon; Qu, Jisnmin; Ramuhalli, Pradeep; Wall, Joe

    2015-11-02

    The objective of this research is to demonstrate that nonlinear ultrasonics (NLU) can be used to directly and quantitatively measure the remaining life in radiation damaged reactor pressure vessel (RPV) and internal components. Specific damage types to be monitored are irradiation embrittlement and irradiation assisted stress corrosion cracking (IASCC). Our vision is to develop a technique that allows operators to assess damage by making a limited number of NLU measurements in strategically selected critical reactor components during regularly scheduled outages. This measured data can then be used to determine the current condition of these key components, from which remaining useful life can be predicted. Methods to unambiguously characterize radiation related damage in reactor internals and RPVs remain elusive. NLU technology has demonstrated great potential to be used as a material sensor – a sensor that can continuously monitor a material’s damage state. The physical effect being monitored by NLU is the generation of higher harmonic frequencies in an initially monochromatic ultrasonic wave. The degree of nonlinearity is quantified with the acoustic nonlinearity parameter, β, which is an absolute, measurable material constant. Recent research has demonstrated that nonlinear ultrasound can be used to characterize material state and changes in microscale characteristics such as internal stress states, precipitate formation and dislocation densities. Radiation damage reduces the fracture toughness of RPV steels and internals, and can leave them susceptible to IASCC, which may in turn limit the lifetimes of some operating reactors. The ability to characterize radiation damage in the RPV and internals will enable nuclear operators to set operation time thresholds for vessels and prescribe and schedule replacement activities for core internals. Such a capability will allow a more clear definition of reactor safety margins. The research consists of three tasks: (1

  15. A forward model and conjugate gradient inversion technique for low-frequency ultrasonic imaging.

    PubMed

    van Dongen, Koen W A; Wright, William M D

    2006-10-01

    Emerging methods of hyperthermia cancer treatment require noninvasive temperature monitoring, and ultrasonic techniques show promise in this regard. Various tomographic algorithms are available that reconstruct sound speed or contrast profiles, which can be related to temperature distribution. The requirement of a high enough frequency for adequate spatial resolution and a low enough frequency for adequate tissue penetration is a difficult compromise. In this study, the feasibility of using low frequency ultrasound for imaging and temperature monitoring was investigated. The transient probing wave field had a bandwidth spanning the frequency range 2.5-320.5 kHz. The results from a forward model which computed the propagation and scattering of low-frequency acoustic pressure and velocity wave fields were used to compare three imaging methods formulated within the Born approximation, representing two main types of reconstruction. The first uses Fourier techniques to reconstruct sound-speed profiles from projection or Radon data based on optical ray theory, seen as an asymptotical limit for comparison. The second uses backpropagation and conjugate gradient inversion methods based on acoustical wave theory. The results show that the accuracy in localization was 2.5 mm or better when using low frequencies and the conjugate gradient inversion scheme, which could be used for temperature monitoring.

  16. A novel technique for micro-hole forming on skull with the assistance of ultrasonic vibration.

    PubMed

    Li, Zhe; Yang, Daoguo; Hao, Weidong; Wu, Tiecheng; Wu, Song; Li, Xiaoping

    2016-04-01

    Micro-hole opening on skull is technically challenging and is hard to realize by micro-drilling. Low-stiffness of the drill bit is a serious drawback in micro-drilling. To deal with this problem, a novel ultrasonic vibration assisted micro-hole forming technique has been developed. Tip geometry and vibration amplitude are two key factors affecting the performance of this hole forming technique. To investigate their effects, experiment was carried out with 300μm diameter tools of three different tip geometries at three different vibration amplitudes. Hole forming performance was evaluated by the required thrust force, dimensional accuracy, exit burr and micro-structure of bone tissue around the generated hole. Based on the findings from current study, the 60° conically tipped tool helps generate a micro-hole of better quality at a smaller thrust force, and it is more suitable for hole forming than the 120° conically tipped tool and the blunt tipped tool. As for the vibration amplitude, when a larger amplitude is used, a micro-hole of better quality and higher dimensional accuracy can be formed at a smaller thrust force. Findings from this study would lay a technical foundation for accurately generating a high-quality micro-hole on skull, which enables minimally invasive insertion of a microelectrode into brain for neural activity measuring.

  17. Fracture detection in crystalline rock using ultrasonic reflection techniques: Volume 1

    SciTech Connect

    Palmer, S.P. )

    1982-11-01

    This research was initiated to investigate using ultrasonic seismic reflection techniques to detect fracture discontinuities in a granitic rock. Initial compressional (P) and shear (SH) wave experiments were performed on a 0.9 {times} 0.9 {times} 0.3 meter granite slab in an attempt to detect seismic energy reflected from the opposite face of the slab. It was found that processing techniques such as deconvolution and array synthesis could improve the standout of the reflection event. During the summers of 1979 and 1980 SH reflection experiments were performed at a granite quarry near Knowles, California. The purpose of this study was to use SH reflection methods to detect an in situ fracture located one to three meters behind the quarry face. These SH data were later analyzed using methods similar to those applied in the laboratory. Interpretation of the later-arriving events observed in the SH field data as reflections from a steeply-dipping fracture was inconclusive. 41 refs., 43 figs., 7 tabs.

  18. PREFACE: 3rd International Symposium on Laser Ultrasonics and Advanced Sensing

    NASA Astrophysics Data System (ADS)

    2014-06-01

    Based on the use of laser as a coherent and intense light source, the photo-acoustics originated from the discovery made by Alexander Graham Bell was extended to laser-ultrasonics (LU), and it has been applied to wide area of ultrasonics, optics, material characterization and nondestructive inspection. In 1996, a research group for LU was started in the Japanese Society for Nondestructive Inspection (JSNDI), and researches on LU and related topics such as noncontact measurements and elastic wave theories were discussed. Similar activities were pursued also in North America and in Europe. The international symposium on LU was started in Montreal, Canada in 2008 by Jean Pierre Monchalin in order to offer a forum for involved with basic researches and industrial applications of LU. In the second symposium in Bordeaux, France nearly 120 papers were presented. It is our honor to have organized the third symposium, LU2013 on 25-28 June in Yokohama, Japan. The articles published here provide a sample of achievements presented there. In LU2013, we focused on the laser generation and/or detection of acoustic waves, application to nondestructive testing, ultrafast-optoacoustics and innovative instruments. Research achievements in biomedical applications, advanced sensing including noncontact, micro/nanoscale or nonlinear measurements, as well as theory and simulation of ultrasound were also included, considering the interdisciplinary nature of this field. We enjoyed very excellent and informative 3 plenary talks, 11 invited talks, 81 oral and 41 poster presentations with 168 attendees. According to requests, we organized a post deadline poster session to give an opportunity to present recent achievements after the deadline. Contributions of the participants, the scientific and organizing committees are highly appreciated. The conference tour was a dinner cruise to the Tokyo bay, and we hope this experience will remain as a pleasant memory in attendees. As decided in the

  19. Hydrodynamic ultrasonic maxillary sinus lift: Review of a new technique and presentation of a clinical case

    PubMed Central

    Romero-Ruiz, Manuel M.; Torres-Lagares, Daniel; Pérez-Dorao, Beatriz; Wainwright, Marcel; Abalos-Labruzzi, Camilo; Gutiérrez-Pérez, José L.

    2012-01-01

    Objectives: Placing implants in the posterior maxillary area has the drawback of working with scarce, poor quality bone in a significant percentage of cases. Numerous advanced surgical techniques have been developed to overcome the difficulties associated with these limitations. Subsequent to reports on the elevation of the maxillary sinus through the lateral approach, there were reports on the use of the crestal approach, which is less aggressive but requires a minimal amount of bone. Furthermore, it is more sensitive to operator technique, as the integrity of the sinus membrane is checked indirectly. The aim of this paper is to review the technical literature on minimally invasive sinus lift and compare the advantages of different techniques with Intralift™, a new technique. Study Design: The present study is a review of techniques used to perform minimally invasive sinus lift published in Cochrane, Embase and Medline over the past ten years and the description of the crestal sinus lift technique based on minimally invasive piezosurgery, with the example of a case report. Results: Only eight articles were found on minimally invasive techniques for sinus lift. The main advantage of this new technique, Intralift, is that it does not require a minimum amount of crestal bone (indeed, the smaller the width of the crestal bone, the better this technique is performed). The possibility of damage to the sinus membrane is minimised by using ultrasound based hydrodynamic pressure to lift it, while applying a very non-aggressive crestal approach. Conclusions: We believe that this technique is an advance in the search for less traumatic and aggressive techniques, which is the hallmark of current surgery. Key words: Sinus lift, surgical technique, minimally invasive surgery, ultrasound surgery. PMID:22143696

  20. Micromachining techniques in developing high-frequency piezoelectric composite ultrasonic array transducers.

    PubMed

    Liu, Changgeng; Djuth, Frank T; Zhou, Qifa; Shung, K Kirk

    2013-12-01

    Several micromachining techniques for the fabrication of high-frequency piezoelectric composite ultrasonic array transducers are described in this paper. A variety of different techniques are used in patterning the active piezoelectric material, attaching backing material to the transducer, and assembling an electronic interconnection board for transmission and reception from the array. To establish the feasibility of the process flow, a hybrid test ultrasound array transducer consisting of a 2-D array having an 8 × 8 element pattern and a 5-element annular array was designed, fabricated, and assessed. The arrays are designed for a center frequency of ~60 MHz. The 2-D array elements are 105 × 105 μm in size with 5-μm kerfs between elements. The annular array surrounds the square 2-D array and provides the option of transmitting from the annular array and receiving with the 2-D array. Each annular array element has an area of 0.71 mm(2) with a 16-μm kerf between elements. The active piezoelectric material is (1 - x) Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-PT)/epoxy 1-3 composite with a PMN-PT pillar lateral dimension of 8 μm and an average gap width of ~4 μm, which was produced by deep reactive ion etching (DRIE) dry etching techniques. A novel electric interconnection strategy for high-density, small-size array elements was proposed. After assembly, the array transducer was tested and characterized. The capacitance, pulse-echo responses, and crosstalk were measured for each array element. The desired center frequency of ~60 MHz was achieved and the -6-dB bandwidth of the received signal was ~50%. At the center frequency, the crosstalk between adjacent 2-D array elements was about -33 dB. The techniques described herein can be used to build larger arrays containing smaller elements.

  1. Advanced crystallization techniques of 'solar grade' silicon

    NASA Astrophysics Data System (ADS)

    Gasparini, M.; Calligarich, C.; Rava, P.; Sardi, L.; Alessandri, M.; Redaelli, F.; Pizzini, S.

    Microstructural, electrical and photo-voltaic characteristics of polycrystal line silicon solar cells fabricated with silicon ingots containing 5, 100 and 500 ppmw iron are reported and discussed. All silicon ingots were grown by the directional solidification technique in graphite or special quartz molds and doped intentionally with iron, in order to evaluate the potentiality of the D.S. technique when employed with solar silicon feedstocks. Results indicate that structural breakdown limits the amount of the ingot which is usable for solar cells fabrication, but also that efficiencies in excess of 10 percent are obtained using the 'good' region of the ingot.

  2. Advanced Numerical Modeling of the Dispersion of Ceramic Nanoparticles during Ultrasonic Cavitation Processing and Solidification of 6061-based Nanocomposites

    NASA Astrophysics Data System (ADS)

    Zhang, D.; Nastac, L.

    2015-06-01

    The metal-matrix-nano-composites (MMNCs) in this study consist of a 6061 alloy matrix reinforced with 1.0 wt.% SiC 50 nm diameter nanoparticles that are dispersed uniformly within the matrix in large volume using an ultrasonic cavitation dispersion technique (UCDS) available in the Solidification Laboratory at UA. The required ultrasonic parameters to achieve the required cavitation for adequate degassing and refining of the aluminium alloy as well as the fluid flow characteristics for uniform dispersion of the nanoparticles into the 6061 matrix are being investigated in this study by using an in-house developed CFD ultrasonic cavitation model. The multiphase CFD model accounts for turbulent fluid flow, heat transfer and solidification as well as the complex interaction between the solidifying alloy and nanoparticles by using the Ansys's Fluent Dense Discrete Phase Model (DDPM) and a particle engulfment and pushing (PEP) model. The PEP model accounts for the Brownian motion. SEM analysis was performed on the as-cast MMNC coupons processed via UCDS and confirmed the distribution of the nanoparticles predicted by the current CFD model. A parametric study was performed using the validated CFD model. The study includes the effects of magnitude of the fluid flow and ultrasonic probe location (gravity direction).

  3. Advances in laparoscopic urologic surgery techniques

    PubMed Central

    Abdul-Muhsin, Haidar M.; Humphreys, Mitchell R.

    2016-01-01

    The last two decades witnessed the inception and exponential implementation of key technological advancements in laparoscopic urology. While some of these technologies thrived and became part of daily practice, others are still hindered by major challenges. This review was conducted through a comprehensive literature search in order to highlight some of the most promising technologies in laparoscopic visualization, augmented reality, and insufflation. Additionally, this review will provide an update regarding the current status of single-site and natural orifice surgery in urology. PMID:27134743

  4. Physical interpretation and development of ultrasonic nondestructive evaluation techniques applied to the quantitative characterization of textile composite materials

    NASA Technical Reports Server (NTRS)

    Miller, James G.

    1994-01-01

    In this Progress Report, we describe our continuing research activities concerning the development and implementation of advanced ultrasonic nondestructive evaluation methods applied to the inspection and characterization of complex composite structures. We explore the feasibility of implementing medical linear array imaging technology as a viable ultrasonic-based nondestructive evaluation method to inspect and characterize complex materials. As an initial step toward the application of linear array imaging technology to the interrogation of a wide range of complex composite structures, we present images obtained using an unmodified medical ultrasonic imaging system of two epoxy-bonded aluminum plate specimens, each with intentionally disbonded regions. These images are compared with corresponding conventional ultrasonic contact transducer measurements in order to assess whether these images can detect disbonded regions and provide information regarding the nature of the disbonded region. We present a description of a standoff/delay fixture which has been designed, constructed, and implemented on a Hewlett-Packard SONOS 1500 medical imaging system. This standoff/delay fixture, when attached to a 7.5 MHz linear array probe, greatly enhances our ability to interrogate flat plate specimens. The final section of this Progress Report describes a woven composite plate specimen that has been specially machined to include intentional flaws. This woven composite specimen will allow us to assess the feasibility of applying linear array imaging technology to the inspection and characterization of complex textile composite materials. We anticipate the results of this on-going investigation may provide a step toward the development of a rapid, real-time, and portable method of ultrasonic inspection and characterization based on linear array technology.

  5. A study of the noncollinear ultrasonic-wave-mixing technique under imperfect resonance conditions.

    PubMed

    Demčenko, A; Mainini, L; Korneev, V A

    2015-03-01

    Geometrical and material property changes cause deviations in the resonant conditions used for noncollinear wave mixing. These deviations are predicted and observed using the SV(ω1)+L(ω2)→L(ω1+ω2) interaction, where SV and L are the shear vertical and longitudinal waves, respectively, and ω1, ω2 are their frequencies. Numerical predictions, performed for the scattered secondary field in the far field zone, show three field features of imperfect resonance conditions: (1) rotation of a scattered beam, (2) decrease in the beam amplitude, and (3) beam splitting. The response of the nonlinear ultrasonic wave mixing technique is verified experimentally in two ways: (1) detection of a kissing bond between two polyvinyl chloride (PVC) plates, and (2) detection of subsurface micro-cracks in polymethyl methacrylate (PMMA). A predominant decrease in nonlinear wave energy is observed in both experiments. Beam rotation and splitting is observed in the kissing-bond experiment, while a minor increase in the nonlinear wave energy up to 100% is observed in the micro-cracked PMMA specimen.

  6. A frequency-domain technique for noninvasive, ultrasonic fluid detection in submerged sealed canisters

    NASA Astrophysics Data System (ADS)

    MacIntosh, Scott; Sinha, Dipen N.; Kaduchak, Gregory; Kwiatkowski, Christopher S.

    2002-11-01

    There are situations where canisters containing specialized parts and/or materials are submerged underwater for storage or safety purposes. In some cases, leaks in the canisters can be detrimental and must be detected as early as possible. The present research describes an ultrasonic method for determining the presence of fluid in sealed, submerged canisters. In this research, the canisters are metallic and are filled with a random array of loose objects. The technique is based on two phenomena: the radiation damping effect of the internal fluid on the container wall and spectral signatures that result from internal reflections within the canister. The experiment utilizes a pair of piezoelectric transducers with a lateral separation of 27 mm. The transducers are placed at a standoff distance of 5 mm from the container wall and traverse the vertical dimension of the canister on a stepper-slide assembly. The transmitter is swept between 0.8-4.0 MHz and a frequency spectrum is collected. By analyzing the contributions to the spectrum from internal radiation damping and internal reflections separately, it can be determined whether the container wall is fluid or air backed. Current results demonstrate that fluid levels as low as 1 cm can be detected.

  7. Real time acousto-ultrasonic NDE technique for monitoring damage in ceramic composites under dynamic loads

    NASA Technical Reports Server (NTRS)

    Tiwari, Anil

    1995-01-01

    Research effort was directed towards developing a near real-time, acousto-ultrasonic (AU), nondestructive evaluation (NDE) tool to study the failure mechanisms of ceramic composites. Progression of damage is monitored in real-time by observing the changes in the received AU signal during the actual test. During the real-time AU test, the AU signals are generated and received by the AU transducers attached to the specimen while it is being subjected to increasing quasi-static loads or cyclic loads (10 Hz, R = 1.0). The received AU signals for 64 successive pulses were gated in the time domain (T = 40.96 micro sec) and then averaged every second over ten load cycles and stored in a computer file during fatigue tests. These averaged gated signals are representative of the damage state of the specimen at that point of its fatigue life. This is also the first major attempt in the development and application of real-time AU for continuously monitoring damage accumulation during fatigue without interrupting the test. The present work has verified the capability of the AU technique to assess the damage state in silicon carbide/calcium aluminosilicate (SiC/CAS) and silicon carbide/ magnesium aluminosilicate (SiC/MAS) ceramic composites. Continuous monitoring of damage initiation and progression under quasi-static ramp loading in tension to failure of unidirectional and cross-ply SiC/CAS and quasi-isotropic SiC/MAS ceramic composite specimens at room temperature was accomplished using near real-time AU parameters. The AU technique was shown to be able to detect the stress levels for the onset and saturation of matrix cracks, respectively. The critical cracking stress level is used as a design stress for brittle matrix composites operating at elevated temperatures. The AU technique has found that the critical cracking stress level is 10-15% below the level presently obtained for design purposes from analytical models. An acousto-ultrasonic stress-strain response (AUSSR) model

  8. [Advanced online search techniques and dedicated search engines for physicians].

    PubMed

    Nahum, Yoav

    2008-02-01

    In recent years search engines have become an essential tool in the work of physicians. This article will review advanced search techniques from the world of information specialists, as well as some advanced search engine operators that may help physicians improve their online search capabilities, and maximize the yield of their searches. This article also reviews popular dedicated scientific and biomedical literature search engines.

  9. Absolute measurement of enhanced fluctuations in assemblies of biomolecules by ultrasonic techniques.

    PubMed Central

    Cerf, R

    1985-01-01

    By expressing the fluctuation-dissipation theorem explicitly, equations are obtained for the ultrasonic relaxation amplitudes that contain one single molecular parameter, i.e., the fluctuation, or the sum of fluctuations. The absolute measurement of this parameter is therefore possible. The equations apply to a two-state system, to a multistate system and to a linear Ising chain as well. In an aqueous medium, where molar volume changes are important, the ultrasonic relaxation amplitudes are proportional to the volume fluctuations. For assemblies of biomolecules that exhibit enhanced ultrasonic absorption on assembly it is possible to measure the increase on assembly of the sum of fluctuations. In view of application to tobacco mosaic virus protein aggregates, examples are given in which the fluctuations associated with two normal modes of relaxation are equally enhanced when the difference of conformational stability of the states is reduced. The corresponding observable changes of the ultrasonic spectra are described. PMID:4016196

  10. Advanced analysis techniques for uranium assay

    SciTech Connect

    Geist, W. H.; Ensslin, Norbert; Carrillo, L. A.; Beard, C. A.

    2001-01-01

    Uranium has a negligible passive neutron emission rate making its assay practicable only with an active interrogation method. The active interrogation uses external neutron sources to induce fission events in the uranium in order to determine the mass. This technique requires careful calibration with standards that are representative of the items to be assayed. The samples to be measured are not always well represented by the available standards which often leads to large biases. A technique of active multiplicity counting is being developed to reduce some of these assay difficulties. Active multiplicity counting uses the measured doubles and triples count rates to determine the neutron multiplication (f4) and the product of the source-sample coupling ( C ) and the 235U mass (m). Since the 35U mass always appears in the multiplicity equations as the product of Cm, the coupling needs to be determined before the mass can be known. A relationship has been developed that relates the coupling to the neutron multiplication. The relationship is based on both an analytical derivation and also on empirical observations. To determine a scaling constant present in this relationship, known standards must be used. Evaluation of experimental data revealed an improvement over the traditional calibration curve analysis method of fitting the doubles count rate to the 235Um ass. Active multiplicity assay appears to relax the requirement that the calibration standards and unknown items have the same chemical form and geometry.

  11. Recent advances in DNA sequencing techniques

    NASA Astrophysics Data System (ADS)

    Singh, Rama Shankar

    2013-06-01

    Successful mapping of the draft human genome in 2001 and more recent mapping of the human microbiome genome in 2012 have relied heavily on the parallel processing of the second generation/Next Generation Sequencing (NGS) DNA machines at a cost of several millions dollars and long computer processing times. These have been mainly biochemical approaches. Here a system analysis approach is used to review these techniques by identifying the requirements, specifications, test methods, error estimates, repeatability, reliability and trends in the cost reduction. The first generation, NGS and the Third Generation Single Molecule Real Time (SMART) detection sequencing methods are reviewed. Based on the National Human Genome Research Institute (NHGRI) data, the achieved cost reduction of 1.5 times per yr. from Sep. 2001 to July 2007; 7 times per yr., from Oct. 2007 to Apr. 2010; and 2.5 times per yr. from July 2010 to Jan 2012 are discussed.

  12. Micromachining Techniques in Developing High-Frequency Piezoelectric Composite Ultrasonic Array Transducers

    PubMed Central

    Liu, Changgeng; Djuth, Frank T.; Zhou, Qifa; Shung, K. Kirk

    2014-01-01

    Several micromachining techniques for the fabrication of high-frequency piezoelectric composite ultrasonic array transducers are described in this paper. A variety of different techniques are used in patterning the active piezoelectric material, attaching backing material to the transducer, and assembling an electronic interconnection board for transmission and reception from the array. To establish the feasibility of the process flow, a hybrid test ultrasound array transducer consisting of a 2-D array having an 8 × 8 element pattern and a 5-element annular array was designed, fabricated, and assessed. The arrays are designed for a center frequency of ~60 MHz. The 2-D array elements are 105 × 105 μm in size with 5-μm kerfs between elements. The annular array surrounds the square 2-D array and provides the option of transmitting from the annular array and receiving with the 2-D array. Each annular array element has an area of 0.71 mm2 with a 16-μm kerf between elements. The active piezoelectric material is (1 − x) Pb(Mg1/3Nb2/3)O3−xPbTiO3 (PMN-PT)/epoxy 1–3 composite with a PMN-PT pillar lateral dimension of 8 μm and an average gap width of ~4 μm, which was produced by deep reactive ion etching (DRIE) dry etching techniques. A novel electric interconnection strategy for high-density, small-size array elements was proposed. After assembly, the array transducer was tested and characterized. The capacitance, pulse–echo responses, and crosstalk were measured for each array element. The desired center frequency of ~60 MHz was achieved and the −6-dB bandwidth of the received signal was ~50%. At the center frequency, the crosstalk between adjacent 2-D array elements was about −33 dB. The techniques described herein can be used to build larger arrays containing smaller elements. PMID:24297027

  13. An effective ultrasonic strain measurement-based shear modulus reconstruction technique for superficial tissues - demonstration on in vitro pork ribs and in vivo human breast tissues

    NASA Astrophysics Data System (ADS)

    Sumi, Chikayoshi; Nakayama, Kiyoshi; Kubota, Mitsuhiro

    2000-06-01

    An effective shear modulus reconstruction technique is described which uses ultrasonic strain measurements for diagnosis of superficial tissues, i.e. our previously developed ultrasonic strain measurement and shear modulus reconstruction methods are combined and enhanced. The technique realizes very low computational load, yet yields fairly high quantitativeness, high stability and spatial resolution, and large dynamic range. The suitability of the method is demonstrated on in vitro pork ribs and in vivo human breast tissues (fibroadenoma and scirrhous carcinoma).

  14. Diagnostics of nonlocal plasmas: advanced techniques

    NASA Astrophysics Data System (ADS)

    Mustafaev, Alexander; Grabovskiy, Artiom; Strakhova, Anastasiya; Soukhomlinov, Vladimir

    2014-10-01

    This talk generalizes our recent results, obtained in different directions of plasma diagnostics. First-method of flat single-sided probe, based on expansion of the electron velocity distribution function (EVDF) in series of Legendre polynomials. It will be demonstrated, that flat probe, oriented under different angles with respect to the discharge axis, allow to determine full EVDF in nonlocal plasmas. It is also shown, that cylindrical probe is unable to determine full EVDF. We propose the solution of this problem by combined using the kinetic Boltzmann equation and experimental probe data. Second-magnetic diagnostics. This method is implemented in knudsen diode with surface ionization of atoms (KDSI) and based on measurements of the magnetic characteristics of the KDSI in presence of transverse magnetic field. Using magnetic diagnostics we can investigate the wide range of plasma processes: from scattering cross-sections of electrons to plasma-surface interactions. Third-noncontact diagnostics method for direct measurements of EVDF in remote plasma objects by combination of the flat single-sided probe technique and magnetic polarization Hanley method.

  15. Innovative Tools Advance Revolutionary Weld Technique

    NASA Technical Reports Server (NTRS)

    2009-01-01

    The iconic, orange external tank of the space shuttle launch system not only contains the fuel used by the shuttle s main engines during liftoff but also comprises the shuttle s backbone, supporting the space shuttle orbiter and solid rocket boosters. Given the tank s structural importance and the extreme forces (7.8 million pounds of thrust load) and temperatures it encounters during launch, the welds used to construct the tank must be highly reliable. Variable polarity plasma arc welding, developed for manufacturing the external tank and later employed for building the International Space Station, was until 1994 the best process for joining the aluminum alloys used during construction. That year, Marshall Space Flight Center engineers began experimenting with a relatively new welding technique called friction stir welding (FSW), developed in 1991 by The Welding Institute, of Cambridge, England. FSW differs from traditional fusion welding in that it is a solid-state welding technique, using frictional heat and motion to join structural components without actually melting any of the material. The weld is created by a shouldered pin tool that is plunged into the seam of the materials to be joined. The tool traverses the line while rotating at high speeds, generating friction that heats and softens but does not melt the metal. (The heat produced approaches about 80 percent of the metal s melting temperature.) The pin tool s rotation crushes and stirs the plasticized metal, extruding it along the seam as the tool moves forward. The material cools and consolidates, resulting in a weld with superior mechanical properties as compared to those weld properties of fusion welds. The innovative FSW technology promises a number of attractive benefits. Because the welded materials are not melted, many of the undesirables associated with fusion welding porosity, cracking, shrinkage, and distortion of the weld are minimized or avoided. The process is more energy efficient, safe

  16. An accurate air temperature measurement system based on an envelope pulsed ultrasonic time-of-flight technique

    NASA Astrophysics Data System (ADS)

    Huang, Y. S.; Huang, Y. P.; Huang, K. N.; Young, M. S.

    2007-11-01

    A new microcomputer based air temperature measurement system is presented. An accurate temperature measurement is derived from the measurement of sound velocity by using an ultrasonic time-of-flight (TOF) technique. The study proposes a novel algorithm that combines both amplitude modulation (AM) and phase modulation (PM) to get the TOF measurement. The proposed system uses the AM and PM envelope square waveform (APESW) to reduce the error caused by inertia delay. The APESW ultrasonic driving waveform causes an envelope zero and phase inversion phenomenon in the relative waveform of the receiver. To accurately achieve a TOF measurement, the phase inversion phenomenon was used to sufficiently identify the measurement pulse in the received waveform. Additionally, a counter clock technique was combined to compute the phase shifts of the last incomplete cycle for TOF. The presented system can obtain 0.1% TOF resolution for the period corresponding to the 40kHz frequency ultrasonic wave. Consequently, with the integration of a humidity compensation algorithm, a highly accurate and high resolution temperature measurement can be achieved using the accurate TOF measurement. Experimental results indicate that the combined standard uncertainty of the temperature measurement is approximately 0.39°C. The main advantages of this system are high resolution measurements, narrow bandwidth requirements, and ease of implementation.

  17. Nondestructive Evaluation of Adhesively Bonded Joints by Acousto-Ultrasonic Technique and Acoustic Emission

    NASA Technical Reports Server (NTRS)

    Nayeb-Hashemi, Hamid; Rossettos, J. N.

    1997-01-01

    Reliable applications of adhesively bonded joints require an effective nondestructive evaluation technique for their bond strength prediction. To properly evaluate factors affecting bond strength, effects of defects such as voids and disbonds on stress distribution in the overlap region must be understood. At the same time, in order to use acousto-ultrasonic (AU) technique to evaluate bond quality, the effect of these defects on dynamic response of single lap joints must be clear. The stress distribution in a single lap joint with and without defects (void or disbond) is analyzed. A bar-Theta parameter which contains adherend and adhesive thickness and properties is introduced. It is shown for bonded joints with bar-Theta greater than 10, that a symmetric void or disbond in the middle of overlap up to the 70 percent of overlap length has negligible effect on bond strength. In contrast frequency response analyses by a finite element technique showed that the dynamic response is affected significantly by the presence of voids or disbonds. These results have direct implication in the interpretations of AU results. Through transmission attenuation and a number of AU parameters for various specimens with and without defects are evaluated. It is found that although void and disbond have similar effects on bond strength (stress distribution), they have completely different effects on wave propagation characteristics. For steel-adhesive-steel specimens with voids, the attenuation changes are related to the bond strength. However, the attenuation changes for specimens with disbond are fairly constant over a disbond range. In order to incorporate the location of defects in AU parameters, a weighting function is introduced. Using an immersion system with focused transducers, a number of AU parameters are evaluated. It is found that by incorporating weighting functions in these parameters better sensitivities (AU parameters vs. bond strength) are achieved. Acoustic emission

  18. Estimation of residual stress in cold rolled iron-disks using magnetic and ultrasonic methods and neutron diffraction technique

    SciTech Connect

    Aksenov, V.L.; Balagurov, A.M.; Taran, Yu.V.; Bokuchava, G.D.; Schreiber, J.

    1995-12-31

    Variation of internal stress states in cold rolled sheet metal can essentially influence the result of forming processes. Therefore it is important to control the forming process by a practicable in line testing method. For this purpose magnetic and ultrasonic nondestructive methods are available. However, it is necessary to calibrate these techniques. This paper describes a first step of such a calibration procedure making use of the neutron diffraction method. On the basis of the diffraction results an assessment of the magnetic and ultrasonic methods for the estimation of residual stress in the cold rolled iron-disks was made. Reasonable measuring concepts for practical applications to forming processes with cold rolled sheet metal are discussed.

  19. Recent advances in ultrasonic-assisted machining for the fabrication of micro/nano-textured surfaces

    NASA Astrophysics Data System (ADS)

    Xu, Shaolin; Kuriyagawa, Tsunemoto; Shimada, Keita; Mizutani, Masayoshi

    2017-02-01

    In this paper, the state of art of ultrasonicassisted machining technologies used for fabrication of micro/nano-textured surfaces is reviewed. Diamond machining is the most widely used method in industry for manufacturing precision parts. For fabrication of fine structures on surfaces, conventional diamond machining methods are competitive by considering the precision of structures, but have limitations at machinable structures and machining efficiency, which have been proved to be partly solved by the integration of ultrasonic vibration motion. In this paper, existing ultrasonic-assisted machining methods for fabricating fine surface structures are reviewed and classified, and a rotary ultrasonic texturing (RUT) technology is mainly introduced by presenting the construction of vibration spindles, the texturing principles, and the applications of textured surfaces. Some new ideas and experimental results are presented. Finally, the challenges in using the RUT method to fabricate micro/ nano-textured surfaces are discussed with respect to texturing strategies, machinable structures, and tool wear.

  20. The acousto-ultrasonic approach

    NASA Technical Reports Server (NTRS)

    Vary, Alex

    1987-01-01

    The nature and underlying rationale of the acousto-ultrasonic approach is reviewed, needed advanced signal analysis and evaluation methods suggested, and application potentials discussed. Acousto-ultrasonics is an NDE technique combining aspects of acoustic emission methodology with ultrasonic simulation of stress waves. This approach uses analysis of simulated stress waves for detecting and mapping variations of mechanical properties. Unlike most NDE, acousto-ultrasonics is less concerned with flaw detection than with the assessment of the collective effects of various flaws and material anomalies. Acousto-ultrasonics has been applied chiefly to laminated and filament-wound fiber reinforced composites. It has been used to assess the significant strength and toughness reducing effects that can be wrought by combinations of essentially minor flaws and diffuse flaw populations. Acousto-ultrasonics assesses integrated defect states and the resultant variations in properties such as tensile, shear, and flexural strengths and fracture resistance. Matrix cure state, porosity, fiber orientation, fiber volume fraction, fiber-matrix bonding, and interlaminar bond quality are underlying factors.

  1. Applying a nonlinear, pitch-catch, ultrasonic technique for the detection of kissing bonds in friction stir welds.

    PubMed

    Delrue, Steven; Tabatabaeipour, Morteza; Hettler, Jan; Van Den Abeele, Koen

    2016-05-01

    Friction stir welding (FSW) is a promising technology for the joining of aluminum alloys and other metallic admixtures that are hard to weld by conventional fusion welding. Although FSW generally provides better fatigue properties than traditional fusion welding methods, fatigue properties are still significantly lower than for the base material. Apart from voids, kissing bonds for instance, in the form of closed cracks propagating along the interface of the stirred and heat affected zone, are inherent features of the weld and can be considered as one of the main causes of a reduced fatigue life of FSW in comparison to the base material. The main problem with kissing bond defects in FSW, is that they currently are very difficult to detect using existing NDT methods. Besides, in most cases, the defects are not directly accessible from the exposed surface. Therefore, new techniques capable of detecting small kissing bond flaws need to be introduced. In the present paper, a novel and practical approach is introduced based on a nonlinear, single-sided, ultrasonic technique. The proposed inspection technique uses two single element transducers, with the first transducer transmitting an ultrasonic signal that focuses the ultrasonic waves at the bottom side of the sample where cracks are most likely to occur. The large amount of energy at the focus activates the kissing bond, resulting in the generation of nonlinear features in the wave propagation. These nonlinear features are then captured by the second transducer operating in pitch-catch mode, and are analyzed, using pulse inversion, to reveal the presence of a defect. The performance of the proposed nonlinear, pitch-catch technique, is first illustrated using a numerical study of an aluminum sample containing simple, vertically oriented, incipient cracks. Later, the proposed technique is also applied experimentally on a real-life friction stir welded butt joint containing a kissing bond flaw.

  2. Ultrasonic Determination Of Recrystallization

    NASA Technical Reports Server (NTRS)

    Generazio, Edward R.

    1988-01-01

    State of recrystallization identified. Measurement of ultrasonic attenuation shows promise as means of detecting recrystallization in metal. Technique applicable to real-time acoustic monitoring of thermomechanical treatments. Starting with work-hardened material, one ultrasonically determines effect of annealing, using correlation between ultrasonic attenuation and temperature.

  3. Advances in gamma titanium aluminides and their manufacturing techniques

    NASA Astrophysics Data System (ADS)

    Kothari, Kunal; Radhakrishnan, Ramachandran; Wereley, Norman M.

    2012-11-01

    Gamma titanium aluminides display attractive properties for high temperature applications. For over a decade in the 1990s, the attractive properties of titanium aluminides were outweighed by difficulties encountered in processing and machining at room temperature. But advances in manufacturing technologies, deeper understanding of titanium aluminides microstructure, deformation mechanisms, and advances in micro-alloying, has led to the production of gamma titanium aluminide sheets. An in-depth review of key advances in gamma titanium aluminides is presented, including microstructure, deformation mechanisms, and alloy development. Traditional manufacturing techniques such as ingot metallurgy and investment casting are reviewed and advances via powder metallurgy based manufacturing techniques are discussed. Finally, manufacturing challenges facing gamma titanium aluminides, as well as avenues to overcome them, are discussed.

  4. 75 FR 44015 - Certain Semiconductor Products Made by Advanced Lithography Techniques and Products Containing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-27

    ... COMMISSION Certain Semiconductor Products Made by Advanced Lithography Techniques and Products Containing... importation of certain semiconductor products made by advanced lithography techniques and products containing... certain semiconductor products made by advanced lithography techniques or products containing same...

  5. Advanced liner-cooling techniques for gas turbine combustors

    NASA Technical Reports Server (NTRS)

    Norgren, C. T.; Riddlebaugh, S. M.

    1985-01-01

    Component research for advanced small gas turbine engines is currently underway at the NASA Lewis Research Center. As part of this program, a basic reverse-flow combustor geometry was being maintained while different advanced liner wall cooling techniques were investigated. Performance and liner cooling effectiveness of the experimental combustor configuration featuring counter-flow film-cooled panels is presented and compared with two previously reported combustors featuring: splash film-cooled liner walls; and transpiration cooled liner walls (Lamilloy).

  6. Detection of porosity in glass ceramic matrix composites using an ultrasonic multiple-gate C-scan technique

    SciTech Connect

    Stubbs, D.A.; Zawada, L.P.

    1996-07-01

    Ceramic matrix composite (CMC) plates consisting of silicon carbide fibers in a barium magnesium aluminosilicate matrix (SiC/BMAS) were obtained for mechanical and thermal properties characterization. Each plate had dimensions of 150 x 150 x 3 mm (6 x 6 x 0.12 in.) from which mechanical test specimens, each 150 mm (6 in.) long, were to be cut. To ensure that the material was properly consolidated and free of porosity, the plates were inspected using an ultrasonic multiple-gate C-scan technique previously developed for graphite epoxy composites. This technique allowed the placement of multiple peak-detection gates between the front and back surface echoes on the A-scan signal. Because each gate recorded the amplitude variation for a very narrow time-of-flight range, the frequent fluctuations in signal amplitude due to the inhomogeneity of the material affected one or two gates at times, while the other gates remained sensitive to small amplitude signals from defects. The increased sensitivity allowed the detection of very small material defects such as porosity. Using this technique for each plate revealed an isolated area of manufacturing abnormalities, presumed to be porosity, near the center of one plate. Based on the C-scan information, the pattern for cutting out the mechanical test specimens was altered and the region containing the abnormalities was sectioned, polished, and optically inspected. Optical microscopy clearly showed extensive porosity and a region of poor consolidation in the matrix material at the depth indicated by the C-scans. Details of the multiple-gate ultrasonic C-scan technique, results of the ultrasonic evaluation, and destructive analysis are discussed.

  7. System and technique for characterizing fluids using ultrasonic diffraction grating spectroscopy

    DOEpatents

    Greenwood, Margaret S.

    2005-04-12

    A system for determining a property of a fluid based on ultrasonic diffraction grating spectroscopy includes a diffraction grating on a solid in contact with the fluid. An interrogation device delivers ultrasound through the solid and a captures a reflection spectrum from the diffraction grating. The reflection spectrum including a diffraction order equal to zero exhibits a peak whose location is used to determine speed of sound in the fluid. A separate measurement of the acoustic impedance is combined with the determined speed of sound to yield a measure of fluid density. A system for determining acoustic impedance includes an ultrasonic transducer on a first surface of a solid member, and an opposed second surface of the member is in contact with a fluid to be monitored. A longitudinal ultrasonic pulse is delivered through the solid member, and a multiplicity of pulse echoes caused by reflections of the ultrasonic pulse between the solid-fluid interface and the transducer-solid interface are detected. The decay rate of the detected echo amplitude as a function of echo number is used to determine acoustic impedance.

  8. Investigating Ultrasonic Diffraction Grating Spectroscopy and Reflection Techniques for Characterizing Slurry Properties

    SciTech Connect

    Burgess, L.W.; Brodsky, A.M.

    2005-12-15

    The U.S. Department of Energy (DOE) has millions of gallons of radioactive liquid and sludge wastes that must be retrieved from underground storage tanks. This waste, in the form of slurries, must be transferred and processed to a final form, such as glass logs. On-line instrumentation to measure the properties of these slurries in real-time during transport is needed in order to prevent plugging and reduce excessive dilution. The results, describes a collaborative effort between Pacific Northwest National Laboratory (PNNL) and the University of Washington to develop a completely new method for using ultrasonics to measure the particle size and viscosity of a slurry. The concepts are based on work in optics on grating-light-reflection spectroscopy (GLRS) at the University of Washington and work on ultrasonic diffraction grating spectroscopy (UDGS) carried out at PNNL. The objective of the research was to extend the GLRS theory for optics to ultrasonics, and to demonstrate its capabilities of UDGS. The proposed ultrasonic method could result in an instrument that would be simple, rugged, and very compact, allowing it to be implemented as part of a pipeline wall at facilities across the DOE complex

  9. A method to obtain reference images for evaluation of ultrasonic tissue characterization techniques.

    PubMed

    Jensen, M S; Wilhjelm, J E; Sahl, B; Brandt, T; Martinsen, K; Jespersen, S K; Falk, E

    2002-05-01

    A general problem when evaluating ultrasonic methods for tissue characterization is that "a golden standard" is seldom known. This paper describes a manual method to obtain a reference image, with the same geometry as the ultrasound image, indicating spatial location of the different tissue types present in the biological tissue scanned in vitro. A 30 x 10 x 2 mm3 piece of formalin fixed porcine tissue was molded into an agar block, which on the top surface, contained a set of fiducial markers, spaced 2.5 mm. The block was submerged into 20 degrees C water and a set of parallel 7.5 MHz spatial compound ultrasound images of tissue and fiducial markers were recorded each 0.5 mm. Guided by the fiducial markers, the agar block was subsequently cut into slices 2.5 mm thick, photographed and finally analyzed histologically identifying these tissues: collagen rich, collagen poor, micro vessels and muscle fibres. Due to: (1) the cutting procedure, (2) the finite size of the ultrasound beam and (3) the spatial variation in propagation velocity, the macroscopic photographs did not align completely with the ultrasound images. Likewise, the histological image is a geometrically distorted version of the macroscopic photograph, due to the histological preparation process. The histological information was "mapped back" into the format of the ultrasound images the following way: On the macroscopic images, outlines were drawn manually which defined the border of the tissue. These outlines were superimposed on the corresponding ultrasound images (identified via the fiducial markers) and modified to encompass what appeared to be tissue regions on the ultrasound images and subsequently re-applied to the macroscopic image. This modified macroscopic outline was used as guideline when drawing outlines identifying regions of the various tissue types. Specifically, the macroscopic image revealed the borders between the different tissues, while the histological image identified the four

  10. The feasibility of the auto tuning respiratory compensation system with ultrasonic image tracking technique.

    PubMed

    Chuang, Ho-Chiao; Hsu, Hsiao-Yu; Nieh, Shu-Kan; Tien, Der-Chi

    2015-01-01

    developed auto tumor localization system can be evaluated. The results show that the simulated respiratory signals under different frequencies of 0.5, 0.333, 0.25, 0.2 and 0.167 Hz with phase lead compensators were improved and stabilized. The compensation rate increased to the range of 7.04$∼ $18.82%, and the final compensation rate is about 97%. Therefore the auto tumor localization system combined with the ultrasound image analysis techniques is feasible.In this study, the developed ultrasound image analysis techniques combined into the auto tumor localization system has the following four advantages: (1) It is a non-invasive way (ultrasonic images) to monitor the entire compensating process of the active respiration instead of using a C-arm (invasive) to observe the organs motion. (2) During radiation therapy, the whole treatment process can be continuous, which can save the overall treatment time. (3) It is an independent system, which can be mounted onto any treatment couch. (4) Users can operate this system easily without the need of prior complicated training process.

  11. In-line monitoring of advanced copper CMP processes with picosecond ultrasonic metrology

    NASA Astrophysics Data System (ADS)

    Hsieh, Ming Hsun; Yeh, J. H.; Tsai, Mingsheng; Yang, Chan Lon; Tan, John; Leary, Sean Patrick

    2006-03-01

    Chemical mechanical planarization (CMP) is a challenging process step for manufacturers implementing dualdamascene architectures at the 65 nm technology node. The polishing rate can vary significantly from wafer-to-wafer, across a single wafer, and across a single die, depending on factors including electroplate profile, slurry chemistry, pad wear, and underlying structure. The process is further complicated by the introduction of low-k dielectrics that have significantly different mechanical properties than the harder SiO II they replace. Picosecond ultrasonics is a nondestructive, small-spot method that can be used for in-line on-product monitoring of metal processes including copper CMP. In this paper we will present gauge-capable picosecond ultrasonic results on copper erosion test structures that also demonstrate excellent correlation with electrical test measurements and TEM results on 65 nm products.

  12. Wafer hot spot identification through advanced photomask characterization techniques

    NASA Astrophysics Data System (ADS)

    Choi, Yohan; Green, Michael; McMurran, Jeff; Ham, Young; Lin, Howard; Lan, Andy; Yang, Richer; Lung, Mike

    2016-10-01

    As device manufacturers progress through advanced technology nodes, limitations in standard 1-dimensional (1D) mask Critical Dimension (CD) metrics are becoming apparent. Historically, 1D metrics such as Mean to Target (MTT) and CD Uniformity (CDU) have been adequate for end users to evaluate and predict the mask impact on the wafer process. However, the wafer lithographer's process margin is shrinking at advanced nodes to a point that the classical mask CD metrics are no longer adequate to gauge the mask contribution to wafer process error. For example, wafer CDU error at advanced nodes is impacted by mask factors such as 3-dimensional (3D) effects and mask pattern fidelity on subresolution assist features (SRAFs) used in Optical Proximity Correction (OPC) models of ever-increasing complexity. These items are not quantifiable with the 1D metrology techniques of today. Likewise, the mask maker needs advanced characterization methods in order to optimize the mask process to meet the wafer lithographer's needs. These advanced characterization metrics are what is needed to harmonize mask and wafer processes for enhanced wafer hot spot analysis. In this paper, we study advanced mask pattern characterization techniques and their correlation with modeled wafer performance.

  13. Bringing The Web Down to Size: Advanced Search Techniques.

    ERIC Educational Resources Information Center

    Huber, Joe; Miley, Donna

    1997-01-01

    Examines advanced Internet search techniques, focusing on six search engines. Includes a chart comparison of nine search features: "include two words,""exclude one of two words,""exclude mature audience content,""two adjacent words,""exact match,""contains first and neither of two following…

  14. Advanced Marketing Core Curriculum. Test Items and Assessment Techniques.

    ERIC Educational Resources Information Center

    Smith, Clifton L.; And Others

    This document contains duties and tasks, multiple-choice test items, and other assessment techniques for Missouri's advanced marketing core curriculum. The core curriculum begins with a list of 13 suggested textbook resources. Next, nine duties with their associated tasks are given. Under each task appears one or more citations to appropriate…

  15. Genioglossus muscle advancement: A modification of the conventional technique.

    PubMed

    García Vega, José Ramón; de la Plata, María Mancha; Galindo, Néstor; Navarro, Miriam; Díez, Daniel; Láncara, Fernando

    2014-04-01

    Obstructive sleep apnoea syndrome (OSAS) is a pathophysiologic condition associated with fragmented sleep and arousals caused by nocturnal mechanical obstruction of the upper airway. This results in behavioural derangements, such as excessive daytime sleepiness and fatigue, and pathophysiologic derangements that cause morbidities and mortality including hypertension, arrhythmias, myocardial infarction, stroke and sudden death. The genioglossus advancement is a proven technique for the treatment of mild to moderate obstructive sleep apnoea syndrome by relieving airway obstruction at the hypopharyngeal level. In this article, we report a modification of the conventional genioglossus advancement described by Riley and Powell. The modification we describe replaces the bone segment at the mandibular basal bone rather than at the mid area of the symphysis. This means a linear movement that allows a greater advancement and avoids the rotation of the genioglossus muscle. Through this article we will describe the advantages of the surgical technique such as greater effectiveness, stability, more pleasing aesthetic outcome and the reduction of potential complications.

  16. An Ultrasonic Actuating Driver for a Central Supporting Bending Mode Using a Motional Current Technique

    NASA Astrophysics Data System (ADS)

    Wen, Fuhliang; Wen, Chao-Chun; Lai, Ming-Hung; Hsu, Ichien

    This paper proposes the design of a driver to deal with a thin-disc central supporting structure ultrasonic actuator based on the vibration modes and the equivalent circuit. In order to gain the electromechanical match at resonant frequency, a spectrum analyzer should measure admittance for driving piezoelectric ceramics. The virtual analyzer also investigated the characteristics of a MODEL-E equivalent circuit based upon the admittance-frequency response. The inherent capacitance from an ultrasonic actuator became the partial component in the design of a resonant circuit. IsSpice software is introduced to simulate as well as the experimental results has demonstrated a high agreement related to the conceptual design and practical implementation for the driving circuit.

  17. Rotary ultrasonic drilling on bone: A novel technique to put an end to thermal injury to bone.

    PubMed

    Gupta, Vishal; Pandey, Pulak M; Gupta, Ravi K; Mridha, Asit R

    2017-03-01

    Bone drilling is common in orthopedic procedures and the heat produced during conventional experimental drilling often exceeds critical temperature of 47 °C and induces thermal osteonecrosis. The osteonecrosis may be the reason for impaired healing, early loosening and implant failure. This study was undertaken to control the temperature rise by interrupted cutting and reduced friction effects at the interface of drill tool and the bone surface. In this work, rotary ultrasonic drilling technique with diamond abrasive particles coated on the hollow drill tool without any internal or external cooling assistance was used. Experiments were performed at room temperature on the mid-diaphysis sections of fresh pig bones, which were harvested immediately after sacrifice of the animal. Both rotary ultrasonic drilling on bone and conventional surgical drilling on bone were performed in a five set of experiments on each process using identical constant process parameters. The maximum temperature of each trial was recorded by K-type thermocouple device. Ethylenediaminetetraacetic acid decalcification was done for microscopic examination of bone. In this comparative procedure, rotary ultrasonic drilling on bone produced much lower temperature, that is, 40.2 °C ± 0.4 °C and 40.3 °C ± 0.2 °C as compared to that of conventional surgical drilling on bone, that is, 74.9 °C ± 0.8 °C and 74.9 °C ± 0.6 °C with respect to thermocouples fixed at first and second position, respectively. The conventional surgical drilling on bone specimens revealed gross tissue burn, microscopic evidence of thermal osteonecrosis and tissue injury in the form of cracks due to the generated force during drilling. But our novel technique showed no such features. Rotary ultrasonic drilling on bone technique is robust and superior to other methods for drilling as it induces no thermal osteonecrosis and does not damage the bone by generating undue forces during

  18. Advanced techniques in safeguarding a conditioning facility for spent fuel

    SciTech Connect

    Rudolf, K.; Weh, R. )

    1992-01-01

    Although reprocessing continues to be the main factor in the waste management of nuclear reactors, the alternative of direct final disposal is currently being developed to the level of industrial applications, based on an agreement between the heads of the federal government and the federal states of Germany. Thus, the Konrad and Gorleben sites are being studied as potential final repositories as is the pilot conditioning facility (PKA) under construction. Discussions on the application of safeguards measures have led to the drafting of an approach that will cover the entire back end of the fuel cycle. The conditioning of fuel prior to direct final disposal represents one element in the overall approach. A modern facility equipped with advanced technology, PKA is a pilot plant with regard to conditioning techniques as well as to safeguards. Therefore, the PKA safeguards approach is expected to facilitate future industrial applications of the conditioning procedure. This cannot be satisfactorily implemented without advanced safeguards techniques. The level of development of the safeguards techniques varies. While advanced camera and seal systems are basically available, the other techniques and methods still require research and development. Feasibility studies and equipment development are geared to providing applicable safeguards techniques in time for commissioning of the PKA.

  19. An ultrasonic through-transmission technique for monitoring the setting of injectable calcium phosphate cement.

    PubMed

    Rajzer, Izabella; Piekarczyk, Wojciech; Castaño, Oscar

    2016-10-01

    An ultrasound through-transmission method to monitor the setting process of injectable calcium phosphate bone cements in body fluids is presented. This method can be used to determine the acoustic properties of the bone cement as it sets, which are linked to its material properties and provide some information about changes occurring within the cement. The development of the methodology of ultrasonic testing and execution of velocity measurements of the longitudinal and transverse waves using the through-transmission method made it possible to determine the material constants of samples during the setting and hardening process of an injectable cement paste in physiological fluids (i.e. the Young's modulus (E), the Poisson ratio (ν) and the shear modulus (G)), and to determine the degree of anisotropy of wave velocity in the samples. A strong advantage of the proposed method is that it is non-destructive, and the same sample can be used to monitor the whole process of the cement setting. The testing was performed on premixed and injectable calcium phosphate (CPC)/chitosan blend, where glycerol was used as a liquid phase. Comparisons between ultrasonic velocity and empirical tests such as compressive strength, porosity measurement, FTIR, SEM and XRD analysis at different days of immersion in Ringer's solutions showed that the ultrasonic velocity can be very useful to provide in situ information about changes occurring within the cement.

  20. Ultrasonic Defect Characterization in Heavy Rotor Forgings by Means of the Synthetic Aperture Focusing Technique and Optimization Methods.

    PubMed

    Fendt, Karl T; Mooshofer, Hubert; Rupitsch, Stefan J; Ermert, Helmut

    2016-06-01

    Ultrasonic nondestructive testing of steel forgings aims at the detection and classification of material inhomogeneities to ensure the components fitness for use. Due to the high price and safety critical nature of large forgings for turbomachinery, there is great interest in the application of imaging algorithms to inspection data. However, small flaw indications that cannot be sufficiently resolved have to be characterized using amplitude-based quantification. One such method is the distance gain size method, which converts the maximum echo amplitudes into the diameters of penny-shaped equivalent size reflectors. The approach presented in this contribution combines the synthetic aperture focusing technique (SAFT) with an iterative inversion scheme to locate and quantify small flaws in a more reliable way. Ultrasonic inspection data obtained in a pulse-echo configuration are reconstructed by means of an Synthetic Focusing Technique (SAFT). From the reconstructed data, the amount and approximate location of small flaws are extracted. These predetermined positions, along with the constrained defect model of a penny-shaped crack, provide the initial parametrization for an elastodynamic simulation based on the Kirchhoff approximation. The identification of the optimal parameter set is achieved through an iteratively regularized Gauss-Newton method. By testing the characterization method on a series of flat-bottom holes under laboratory conditions, we demonstrate that the procedure is applicable over a wide range of defect sizes. To show suitability for large forging inspection, we additionally evaluate the inspection data of a large generator shaft forging of 0.6-m diameter.

  1. The ultrasonic technique for in situ investigations on stones: suggestions for uses

    NASA Astrophysics Data System (ADS)

    Bellopede, R.; Marini, P.

    2012-04-01

    The Ultrasound Pulse Velocity (UPV) is one of the main non destructive techniques to detect both in laboratory and in situ the stone decay and many international papers of the recent years deal with its application. This technique is often executed in laboratory, where the possibility to keep constant the environmental and test conditions are a guarantee of the reliability of the results. It is known in fact the UPV are mainly conditioned by the following factors: - the characteristics of the stone tested (not only petrographic properties such as texture and structure, but even specimen dimension and water content); - the transducers features such as frequency, divergence angle , near field and wavelength; - external climate factors such as environmental temperature, humidity. In spite of the many factors affecting the measurements, UPV performed in laboratory is well correlated with mechanical strength of the stone , with its porosity and, as consequence, it is a reliable technique to detect the durability of a stone. On the other side, for in situ UPV test it is important to take into account that the measurement uncertainty is affected by the unknown water content in the stone. From tests performed on different rocks (marble, limestones, travertines, granites, gneiss, schists , sandstones) , the ratios between UPV tested in dry and saturated conditions can be > 1 or < 1 depending on the porosity . On the base of the results obtained, in this paper suggestions for UPV measurements in situ have been advanced concerning: the importance of the petrographic characterization of the stone in order to choose the suitable measurement frequency; the correct choice of transducers frequencies; the use of a reference slab, with a known UPV in dry conditions, to be exposed in the investigated site some days before the in situ tests, in order to appreciate the UPV variation due to climate factors.

  2. Advanced signal processing technique for damage detection in steel tubes

    NASA Astrophysics Data System (ADS)

    Amjad, Umar; Yadav, Susheel Kumar; Dao, Cac Minh; Dao, Kiet; Kundu, Tribikram

    2016-04-01

    In recent years, ultrasonic guided waves gained attention for reliable testing and characterization of metals and composites. Guided wave modes are excited and detected by PZT (Lead Zirconate Titanate) transducers either in transmission or reflection mode. In this study guided waves are excited and detected in the transmission mode and the phase change of the propagating wave modes are recorded. In most of the other studies reported in the literature, the change in the received signal strength (amplitude) is investigated with varying degrees of damage while in this study the change in phase is correlated with the extent of damage. Feature extraction techniques are used for extracting phase and time-frequency information. The main advantage of this approach is that the bonding condition between the transducer and the specimen does not affect the phase while it can affect the strength of recorded signal. Therefore, if the specimen is not damaged but the transducer-specimen bonding is deteriorated then the received signal strength is altered but the phase remains same and thus false positive predictions for damage can be avoided.

  3. Advanced Packaging Materials and Techniques for High Power TR Module: Standard Flight vs. Advanced Packaging

    NASA Technical Reports Server (NTRS)

    Hoffman, James Patrick; Del Castillo, Linda; Miller, Jennifer; Jenabi, Masud; Hunter, Donald; Birur, Gajanana

    2011-01-01

    The higher output power densities required of modern radar architectures, such as the proposed DESDynI [Deformation, Ecosystem Structure, and Dynamics of Ice] SAR [Synthetic Aperture Radar] Instrument (or DSI) require increasingly dense high power electronics. To enable these higher power densities, while maintaining or even improving hardware reliability, requires advances in integrating advanced thermal packaging technologies into radar transmit/receive (TR) modules. New materials and techniques have been studied and compared to standard technologies.

  4. Altered Apical Morphology (Reverse Architecture): Use of Indirect Ultrasonic Technique for Orthograde MTA Placement in Maxillary Premolars

    PubMed Central

    Sonali, Kapoor; Suresh, Agrawal Vineet; Abhishek, Patel; Jenish, Patel

    2016-01-01

    Aim. To report the management and orthograde technique of MTA placement in case of reverse architecture maxillary premolars. Summary. Two cases of 17-year-old and 21-year-old female patients were referred to endodontic speciality for management of maxillary premolar having reverse architecture with wide immature open apex like a bell mouth. In both the cases, after control of intraradicular infection, it was decided to use MTA for apexification and obturation of canals. Orthograde placement of MTA is a challenging procedure in terms of length control and condensation especially in divergent irregular reverse architecture wide open apex. A novel technique with the help of finger plugger, sterilized paper point, and ultrasonic agitation for 3D compaction of MTA at apical reverse architecture was used. Thickening of the canal wall and complete apical closure were confirmed one year after the treatment. PMID:27313910

  5. An Efficient Algorithm Embedded in an Ultrasonic Visualization Technique for Damage Inspection Using the AE Sensor Excitation Method

    PubMed Central

    Liu, Yaolu; Goda, Riu; Samata, Kiyoshi; Kanda, Atsushi; Hu, Ning; Zhang, Jianyu; Ning, Huiming; Wu, Liangke

    2014-01-01

    To improve the reliability of a Lamb wave visualization technique and to obtain more information about structural damages (e.g., size and shape), we put forward a new signal processing algorithm to identify damage more clearly in an inspection region. Since the kinetic energy of material particles in a damaged area would suddenly change when ultrasonic waves encounter the damage, the new algorithm embedded in the wave visualization technique is aimed at monitoring the kinetic energy variations of all points in an inspection region to construct a damage diagnostic image. To validate the new algorithm, three kinds of surface damages on the center of aluminum plates, including two non-penetrative slits with different depths and a circular dent, were experimentally inspected. From the experimental results, it can be found that the new algorithm can remarkably enhance the quality of the diagnostic image, especially for some minor defects. PMID:25356647

  6. Development of an advanced multimode automatic ultrasonic texture measurement system for laboratory and production line application.

    PubMed

    Potter, M D G; Dixon, S; Morrison, J P; Suliamann, A S

    2006-12-22

    We present work on the development of an ultrasonic texture measurement system for sheet metals using non-contact transducers, suitable for use both in the laboratory and on the production line. Variation of the velocity of the zero-order symmetric (S0) Lamb wave is used to determine the crystallographic texture of polycrystalline metal sheets ranging in thickness from 0.1 to 3 mm. This system features improvements on previous state-of-the-art ultrasonic technology in that it probes velocity over a continuous range of angles using only two electromagnetic acoustic transducers (EMATs). This is demonstrated to offer a significant improvement in accuracy and allows the detection and investigation of asymmetric anisotropies in the sheets. Another advantage of the system is its potential for combining several different measurements using a single pair of transducers. The capability is demonstrated for through-thickness shear wave measurements as well as the zero-order symmetric Lamb wave measurements which are the primary means of determining the texture. The change between generating Lamb and through-thickness bulk waves can be made entirely by changing the electrical circuit connected to the EMATs without modifying the transducer assembly in any way. Measurement of all of the above waves can provide information on the sheet thickness and other physical properties of the sheet in addition to texture. Certain texture parameters can be calculated from both Lamb and shear wave velocities, allowing self-calibration of the system.

  7. Technology development of fabrication techniques for advanced solar dynamic concentrators

    NASA Technical Reports Server (NTRS)

    Richter, Scott W.

    1991-01-01

    The objective of the advanced concentrator program is to develop the technology that will lead to lightweight, highly reflective, accurate, scaleable, and long lived space solar dynamic concentrators. The advanced concentrator program encompasses new and innovative concepts, fabrication techniques, materials selection, and simulated space environmental testing. Fabrication techniques include methods of fabricating the substrates and coating substrate surfaces to produce high quality optical surfaces, acceptable for further coating with vapor deposited optical films. The selected materials to obtain a high quality optical surface include microsheet glass and Eccocoat EP-3 epoxy, with DC-93-500 selected as a candidate silicone adhesive and levelizing layer. The following procedures are defined: cutting, cleaning, forming, and bonding microsheet glass. Procedures are also defined for surface cleaning, and EP-3 epoxy application. The results and analyses from atomic oxygen and thermal cycling tests are used to determine the effects of orbital conditions in a space environment.

  8. Investigating Ultrasonic Diffraction Grating Spectroscopy and Reflection Techniques for Characterizing Slurry Properties

    SciTech Connect

    Greenwood, Margaret S.; Salahuddin Ahmed

    2006-06-01

    The particle size of a slurry and the viscosity of a liquid or slurry are both difficult to measure on-line and in real time. The objectives of this research are to develop the following methods for such measurements: (1) ultrasonic diffraction grating spectroscopy (UDGS) to measure the particle size and concentration of a slurry, (2) develop theoretical models and computer codes to describe the passage of ultrasound through a grating surface in order to increase the sensitivity of the particle size measurement.

  9. Advanced thermal management techniques for space power electronics

    NASA Astrophysics Data System (ADS)

    Reyes, Angel Samuel

    1992-01-01

    Modern electronic systems used in space must be reliable and efficient with thermal management unaffected by outer space constraints. Current thermal management techniques are not sufficient for the increasing waste heat dissipation of novel electronic technologies. Many advanced thermal management techniques have been developed in recent years that have application in high power electronic systems. The benefits and limitations of emerging cooling technologies are discussed. These technologies include: liquid pumped devices, mechanically pumped two-phase cooling, capillary pumped evaporative cooling, and thermoelectric devices. Currently, liquid pumped devices offer the most promising alternative for electronics thermal control.

  10. Data Compression Techniques for Advanced Space Transportation Systems

    NASA Technical Reports Server (NTRS)

    Bradley, William G.

    1998-01-01

    Advanced space transportation systems, including vehicle state of health systems, will produce large amounts of data which must be stored on board the vehicle and or transmitted to the ground and stored. The cost of storage or transmission of the data could be reduced if the number of bits required to represent the data is reduced by the use of data compression techniques. Most of the work done in this study was rather generic and could apply to many data compression systems, but the first application area to be considered was launch vehicle state of health telemetry systems. Both lossless and lossy compression techniques were considered in this study.

  11. Advance techniques for monitoring human tolerance to positive Gz accelerations

    NASA Technical Reports Server (NTRS)

    Pelligra, R.; Sandler, H.; Rositano, S.; Skrettingland, K.; Mancini, R.

    1973-01-01

    Tolerance to positive g accelerations was measured in ten normal male subjects using both standard and advanced techniques. In addition to routine electrocardiogram, heart rate, respiratory rate, and infrared television, monitoring techniques during acceleration exposure included measurement of peripheral vision loss, noninvasive temporal, brachial, and/or radial arterial blood flow, and automatic measurement of indirect systolic and diastolic blood pressure at 60-sec intervals. Although brachial and radial arterial flow measurements reflected significant cardiovascular changes during and after acceleration, they were inconsistent indices of the onset of grayout or blackout. Temporal arterial blood flow, however, showed a high correlation with subjective peripheral light loss.

  12. Three-dimensional hybrid grid generation using advancing front techniques

    NASA Technical Reports Server (NTRS)

    Steinbrenner, John P.; Noack, Ralph W.

    1995-01-01

    A new 3-dimensional hybrid grid generation technique has been developed, based on ideas of advancing fronts for both structured and unstructured grids. In this approach, structured grids are first generate independently around individual components of the geometry. Fronts are initialized on these structure grids, and advanced outward so that new cells are extracted directly from the structured grids. Employing typical advancing front techniques, cells are rejected if they intersect the existing front or fail other criteria When no more viable structured cells exist further cells are advanced in an unstructured manner to close off the overall domain, resulting in a grid of 'hybrid' form. There are two primary advantages to the hybrid formulation. First, generating blocks with limited regard to topology eliminates the bottleneck encountered when a multiple block system is used to fully encapsulate a domain. Individual blocks may be generated free of external constraints, which will significantly reduce the generation time. Secondly, grid points near the body (presumably with high aspect ratio) will still maintain a structured (non-triangular or tetrahedral) character, thereby maximizing grid quality and solution accuracy near the surface.

  13. Strategies and advanced techniques for marine pollution studies

    SciTech Connect

    Giam, C.S.; Dou, H.J.M.

    1986-01-01

    Here is a review of strategies and techniques for evaluating marine pollution by hazardous organic compounds. Geo-chemical considerations such as the relationship between the inputs, atmospheric and estuarine transport, and the outputs, sedimentation and degradation, guide the decision on appropriate approaches to pollution monitoring in the marine environment. The latest instrumental methods and standard protocols for analysis of organic compounds are presented, as well as advances in interpretation and correlation of data made possible by the accessibility of commercial data bases.

  14. Development and field application of a nonlinear ultrasonic modulation technique for fatigue crack detection without reference data from an intact condition

    NASA Astrophysics Data System (ADS)

    Lim, Hyung Jin; Kim, Yongtak; Koo, Gunhee; Yang, Suyoung; Sohn, Hoon; Bae, In-hwan; Jang, Jeong-Hwan

    2016-09-01

    In this study, a fatigue crack detection technique, which detects a fatigue crack without relying on any reference data obtained from the intact condition of a target structure, is developed using nonlinear ultrasonic modulation and applied to a real bridge structure. Using two wafer-type lead zirconate titanate (PZT) transducers, ultrasonic excitations at two distinctive frequencies are applied to a target inspection spot and the corresponding ultrasonic response is measured by another PZT transducer. Then, the nonlinear modulation components produced by a breathing-crack are extracted from the measured ultrasonic response, and a statistical classifier, which can determine if the nonlinear modulation components are statistically significant in comparison with the background noise level, is proposed. The effectiveness of the proposed fatigue crack detection technique is experimentally validated using the data obtained from aluminum plates and aircraft fitting-lug specimens under varying temperature and loading conditions, and through a field testing of Yeongjong Grand Bridge in South Korea. The uniqueness of this study lies in that (1) detection of a micro fatigue crack with less than 1 μm width and fatigue cracks in the range of 10-20 μm in width using nonlinear ultrasonic modulation, (2) automated detection of fatigue crack formation without using reference data obtained from an intact condition, (3) reliable and robust diagnosis under varying temperature and loading conditions, (4) application of a local fatigue crack detection technique to online monitoring of a real bridge.

  15. X-radiography, XRD and Ultrasonic Data Transfer Function Technique - Simultaneous Measurements Under Simulated Mantle Conditions in a Multi-Anvil Device

    NASA Astrophysics Data System (ADS)

    Mueller, H. J.; Schilling, F. R.; Lathe, C.

    2004-05-01

    The interpretation of seismic data from the Earth's deep interior requires measurements of the physical properties of Earth materials under experimental simulated mantle conditions. Elastic wave velocity measurement is an important tool for the determination of the elastic properties. Ultrasonic interferometry allows the highly precise travel time measurement at a sample enclosed in a high-pressure multi-anvil device. But the calculation of wave velocities requires the exact sample length under in situ conditions. There are two options - scanning the interfaces of the sample by XRD (Mueller et al., 2003) and X-radiography (Li et al., 2001). The multi-anvil apparatus MAX80 is equipped for both methods. Only the X-radiography is fast enough for transient measurements. Contrary to XRD measurements, imaging the sample by X-rays requires a beam diameter larger than the sample length. Therefore the fixed primary slits of Max80 were exchanged by 4-blade high precision slits of Advanced Design Consulting, Inc. A Ce-YAG-crystal converts the X-ray image to an optical one, redirected by a mirror and captured by a CCD-camera. To derive the sample length, the different brightness of sample, buffer rod and reflector at the electronic image is evaluated. Classical ultrasonic interferometry is very time consuming, because the ultrasonic waves of the frequency range under study are generated and detected one after another with a given step rate. A 60 MHz frequency sweep with 100 kHz steps lasts for more than 30 minutes. This is a serious limitation for all transient measurements, but also limits the data collection at elevated temperatures to prevent the pressure transmitting boron epoxy cubes and the anvils from overheating. The ultrasonic transfer function technique (UTF), first described by Li et al. (2002), generates all the frequencies simultaneously. Related to the results and experiences of Li the UTF-technique was developed independently at GFZ. This version allows to

  16. Advanced endoscopic ultrasound management techniques for preneoplastic pancreatic cystic lesions

    PubMed Central

    Arshad, Hafiz Muhammad Sharjeel; Bharmal, Sheila; Duman, Deniz Guney; Liangpunsakul, Suthat; Turner, Brian G

    2017-01-01

    Pancreatic cystic lesions can be benign, premalignant or malignant. The recent increase in detection and tremendous clinical variability of pancreatic cysts has presented a significant therapeutic challenge to physicians. Mucinous cystic neoplasms are of particular interest given their known malignant potential. This review article provides a brief but comprehensive review of premalignant pancreatic cystic lesions with advanced endoscopic ultrasound (EUS) management approaches. A comprehensive literature search was performed using PubMed, Cochrane, OVID and EMBASE databases. Preneoplastic pancreatic cystic lesions include mucinous cystadenoma and intraductal papillary mucinous neoplasm. The 2012 International Sendai Guidelines guide physicians in their management of pancreatic cystic lesions. Some of the advanced EUS management techniques include ethanol ablation, chemotherapeutic (paclitaxel) ablation, radiofrequency ablation and cryotherapy. In future, EUS-guided injections of drug-eluting beads and neodymium:yttrium aluminum agent laser ablation is predicted to be an integral part of EUS-guided management techniques. In summary, International Sendai Consensus Guidelines should be used to make a decision regarding management of pancreatic cystic lesions. Advanced EUS techniques are proving extremely beneficial in management, especially in those patients who are at high surgical risk. PMID:27574295

  17. Voigt, Reuss, Hill, and self-consistent techniques for modeling ultrasonic scattering

    NASA Astrophysics Data System (ADS)

    Kube, Christopher M.; Turner, Joseph A.

    2015-03-01

    An elastic wave propagating in a metal loses a portion of its energy from scattering caused by acoustic impedance differences existing at the boundaries of anisotropic grains. Theoretical scattering models capture this phenomena by assuming the incoming wave is described by an average elastic moduli tensor Cijkl0(x) that is perturbed by a grain with elasticity Cijkl(x') where the scattering event occurs when x = x'. Previous models have assumed that Cijkl0(x) is the Voigt average of the single-crystal elastic moduli tensor. However, this assumption may be incorrect because the Voigt average overestimates the wave's phase velocity. Thus, the use of alternate definitions of Cijkl0(x) to describe the incoming wave is posed. Voigt, Reuss, Hill, and self-consistent definitions of Cijkl0(x) are derived in the context of ultrasonic scattering models. The scattering-based models describing ultrasonic backscatter, attenuation, and diffusion are shown to be highly dependent on the definition of Cijkl0(x) .

  18. System and technique for characterizing fluids using ultrasonic diffraction grating spectroscopy

    DOEpatents

    Greenwood, Margaret S.

    2008-07-08

    A system for determining property of multiphase fluids based on ultrasonic diffraction grating spectroscopy includes a diffraction grating on a solid in contact with the fluid. An interrogation device delivers ultrasound through the solid and a captures a reflection spectrum from the diffraction grating. The reflection spectrum exhibits peaks whose relative size depends on the properties of the various phases of the multiphase fluid. For example, for particles in a liquid, the peaks exhibit dependence on the particle size and the particle volume fraction. Where the exact relationship is know know a priori, data from different peaks of the same reflection spectrum or data from the peaks of different spectra obtained from different diffraction gratings can be used to resolve the size and volume fraction.

  19. Fabrication of capacitive micromachined ultrasonic transducers based on adhesive wafer bonding technique

    NASA Astrophysics Data System (ADS)

    Li, Zhenhao; Wong, Lawrence L. P.; Chen, Albert I. H.; Na, Shuai; Sun, Jame; Yeow, John T. W.

    2016-11-01

    This paper reports the fabrication process of wafer bonded capacitive micromachined ultrasonic transducers (CMUTs) using photosensitive benzocyclobutene as a polymer adhesive. Compared with direct bonding and anodic bonding, polymer adhesive bonding provides good tolerance to wafer surface defects and contamination. In addition, the low process temperature of 250 °C is compatible with standard CMOS processes. Single-element CMUTs consisting of cells with a diameter of 46 µm and a cavity depth of 323 nm were fabricated. In-air and immersion acoustic characterizations were performed on the fabricated CMUTs, demonstrating their capability for transmitting and receiving ultrasound signals. An in-air resonance frequency of 5.47 MHz was measured by a vibrometer under a bias voltage of 300 V.

  20. Through-transmission ultrasonic imaging of subsurface defects using non-contact laser techniques

    NASA Astrophysics Data System (ADS)

    Dewhurst, R. J.; Shan, Q.

    Through-transmission ultrasonic NDT measurements have been performed with a noncontact laser combination system. High power (about 2 MW) laser pulses were used for the generation of longitudinal pulses in metallic samples. On reaching the far surface, ultrasound was detected with a 50 cm confocal Fabry-Perot interferometer. The interferometer analysed speckle from backscattered laser light so that measurements could be made from samples with only a machine finish. Signal-to-noise ratios were sufficiently good for 2D scans to be performed, producing optical images of artificial defects. For improved image quality, signals were normalized taking into account changes in sample surface reflectivity. Median filtering was also used. Results show that images of 4-mm diameter drill holes can be obtained with resolutions of +/- 0.5 mm.

  1. Two-phase air-water stratified flow measurement using ultrasonic techniques

    SciTech Connect

    Fan, Shiwei; Yan, Tinghu; Yeung, Hoi

    2014-04-11

    In this paper, a time resolved ultrasound system was developed for investigating two-phase air-water stratified flow. The hardware of the system includes a pulsed wave transducer, a pulser/receiver, and a digital oscilloscope. The time domain cross correlation method is used to calculate the velocity profile along ultrasonic beam. The system is able to provide velocities with spatial resolution of around 1mm and the temporal resolution of 200μs. Experiments were carried out on single phase water flow and two-phase air-water stratified flow. For single phase water flow, the flow rates from ultrasound system were compared with those from electromagnetic flow (EM) meter, which showed good agreement. Then, the experiments were conducted on two-phase air-water stratified flow and the results were given. Compared with liquid height measurement from conductance probe, it indicated that the measured velocities were explainable.

  2. Microencapsulation effectiveness of small active molecules in biopolymer by ultrasonic atomization technique.

    PubMed

    Cascone, Sara; Lamberti, Gaetano; Titomanlio, Giuseppe; Barba, Anna Angela; d'Amore, Matteo

    2012-12-01

    A method to produce biopolymeric (alginate) microparticles by ultrasonic assisted atomization, previously developed, has been applied to the production of microparticles loaded with a small active molecule (theophylline). Fine loaded alginate droplets have been cross-linked with divalent ions to produce microparticles. Once produced, the particles have been separated by centrifugation or filtration and then they have been dried. Drug release has been evaluated by dissolution tests, dissolving the dried particles in acidic solution at pH 1 for a given time and then at pH 7 to simulate the stomach and intestinal environment, respectively. The encapsulation efficiency and the drug loading have been investigated and the operating conditions have been changed to clarify the role of the transport phenomena on the overall process. To increase the drug loading, shorter separation time and better network's structure were identified as the key operating parameters to allow the process to gain interest from a practical point of view.

  3. Formulation and optimization of efavirenz nanosuspensions using the precipitation-ultrasonication technique for solubility enhancement.

    PubMed

    Taneja, Sakshi; Shilpi, Satish; Khatri, Kapil

    2016-05-01

    Efavirenz is a non-nucleoside reverse transcriptase inhibitor, and is classified as BCS Class II API. Its erratic oral absorption and poor bioavailability make it a potential candidate for being formulated as a nanosuspension. The objective of this study was to formulate efavirenz nanosuspensions employing the antisolvent precipitation-ultrasonication method, and to enhance its solubility by reducing particle size to the nanometer range. The effects of different process parameters were studied and optimized with respect to particle size and poly dispersity index (PDI). The optimized formulation was also subjected to lyophilization, to further increase the solubility and stability, and the technology is potentially suited to a range of poorly water-soluble compounds.

  4. Review and discussion of the development of synthetic aperture focusing technique for ultrasonic testing (SAFT-UT)

    SciTech Connect

    Busse, L J; Collins, H D; Doctor, S R

    1984-03-01

    The development and capabilities of synthetic aperture focusing techniques for ultrasonic testing (SAFT-UT) are presented. The purpose of SAFT-UT is to produce high-resolution images of the interior of opaque objects. The goal of this work is to develop and implement methods which can be used to detect and to quantify the extent of defects and cracks in critical components of nuclear reactors (pressure vessels, primary piping systems, and nozzles). This report places particular emphasis upon the practical experimental results that have been obtained using SAFT-UT as well as the theoretical background that underlies synthetic aperture focusing. A discussion regarding high-speed and real-time implementations of two- and three-dimensional synthetic aperture focusing is also presented.

  5. Non-destructive evaluation of the cladding thickness in LEU fuel plates by accurate ultrasonic scanning technique

    SciTech Connect

    Borring, J.; Gundtoft, H.E.; Borum, K.K.; Toft, P.

    1997-08-01

    In an effort to improve their ultrasonic scanning technique for accurate determination of the cladding thickness in LEU fuel plates, new equipment and modifications to the existing hardware and software have been tested and evaluated. The authors are now able to measure an aluminium thickness down to 0.25 mm instead of the previous 0.35 mm. Furthermore, they have shown how the measuring sensitivity can be improved from 0.03 mm to 0.01 mm. It has now become possible to check their standard fuel plates for DR3 against the minimum cladding thickness requirements non-destructively. Such measurements open the possibility for the acceptance of a thinner nominal cladding than normally used today.

  6. Development of a novel ultrasonic technique for real-time measurement of membrane fouling in reverse osmosis desalination

    NASA Astrophysics Data System (ADS)

    Mairal, Anurag Prabhakar

    1998-09-01

    Fouling is readily acknowledged to be one of the most critical problems with respect to wider application of membranes in liquid separations. The overall thrust of this research was the development of a novel means for in situ monitoring of the membrane fouling process, ultrasonic time-domain reflectometry (UTDR), to provide real-time characterization of the fouling layer. The specific objectives of this research were to adapt UTDR as an analytical tool to study inorganic membrane fouling, to use the information obtained from UTDR to evaluate membrane fouling models in more detail than previously possible, and to develop improved fouling models, if necessary. A completely-automated separation system and a 75 cm-long rectangular module were developed in this work to adapt and optimize UTDR for the measurement of membrane fouling; six measurement ports in the module permitted simultaneous monitoring of permeate flux, permeate concentration, and UTDR response in terms of reflected signal amplitude, as a function of time and axial position. The experimental results obtained using this module show that there is an excellent correspondence between the flux decline behavior and the UTDR response with respect to initiation of fouling. Moreover, the ultrasonic technique was capable of detecting two distinct modes of fouling layer growth at high axial velocities (>=4.6 cm/s); the first mode was characterized by rapid growth of randomly-oriented crystals, and was followed by a second mode exhibiting a more gradual growth of laterally-oriented crystals. In contrast, permeation data were unable to provide any information about the subtle dynamics of the fouling process. In addition to the measurement of fouling, the ultrasonic technique was also successfully employed for monitoring membrane cleaning at ambient conditions. Since no real-time permeation data are available during such cleaning operations in industrial installations, UTDR may prove to be a very useful implement for

  7. Usefulness of ultrasonic strain measurement-based mechanical properties imaging technique: toward realization of short time diagnosis/treatment

    NASA Astrophysics Data System (ADS)

    Sumi, Chikayoshi; Kubota, Mitsuhiro; Wakabayashi, Gou; Tanabe, Minoru

    2003-06-01

    For various soft tissues (e.g., liver, breast, etc.), we are developing the ultrasonic strain measurement-based mechanical properties (shear modulus, visco-shear modulus, etc.) reconstruction/imaging technique. To clarify the limitation of our quantitative reconstruction/imaging technique as a diagnostic tool for differentiating malignancies, together with improving the spatial resolution and the dynamic range we are collecting the clinical reconstruction image data. Furthermore, we are applying our technique as a monitoring technique for the effectiveness of chemical therapy (e.g., anticancer drug, ethanol, etc.), thermal therapy (e.g., micro, and rf electromagnetic wave, HIFU, LASER, etc.), and cryotherapy. As soft tissues are deformed in 3-D space due to externally situated quasi-static and/or low frequency mechanical sources, multidimensional signal processing improves strain measurement accuracy and reduces inhomogeneity-dependent modulus reconstruction artifacts. These have been verified by us through simulations and phantom/animal in vitro experiments. Briefly, here we discuss the limitations of low dimensional signal processing. Moreover, we exhibit the superiority both on differential diagnosis for these human in vivo malignancies and monitoring for these therapies of our quasi-real time imaging (using conventional US equipment) to conventional B-mode imaging. Our technique is available as a clinical visualization technique both for diagnosis and treatment, and monitored mechanical properties data can also be effectively utilized as the measure for controlling the therapy, i.e., the exposure energy, the foci, the exposure interval, etc. In the near future, suitable combination of various simple and low-invasive therapy techniques with our imaging technique will open up a new clinical style allowing diagnosis and the subsequently immediate treatment. This must substantially reduce the total medical expenses.

  8. Advanced computer modeling techniques expand belt conveyor technology

    SciTech Connect

    Alspaugh, M.

    1998-07-01

    Increased mining production is continuing to challenge engineers and manufacturers to keep up. The pressure to produce larger and more versatile equipment is increasing. This paper will show some recent major projects in the belt conveyor industry that have pushed the limits of design and engineering technology. Also, it will discuss the systems engineering discipline and advanced computer modeling tools that have helped make these achievements possible. Several examples of technologically advanced designs will be reviewed. However, new technology can sometimes produce increased problems with equipment availability and reliability if not carefully developed. Computer modeling techniques that help one design larger equipment can also compound operational headaches if engineering processes and algorithms are not carefully analyzed every step of the way.

  9. Advanced aeroservoelastic stabilization techniques for hypersonic flight vehicles

    NASA Technical Reports Server (NTRS)

    Chan, Samuel Y.; Cheng, Peter Y.; Myers, Thomas T.; Klyde, David H.; Magdaleno, Raymond E.; Mcruer, Duane T.

    1992-01-01

    Advanced high performance vehicles, including Single-Stage-To-Orbit (SSTO) hypersonic flight vehicles, that are statically unstable, require higher bandwidth flight control systems to compensate for the instability resulting in interactions between the flight control system, the engine/propulsion dynamics, and the low frequency structural modes. Military specifications, such as MIL-F-9490D and MIL-F-87242, tend to limit treatment of structural modes to conventional gain stabilization techniques. The conventional gain stabilization techniques, however, introduce low frequency effective time delays which can be troublesome from a flying qualities standpoint. These time delays can be alleviated by appropriate blending of gain and phase stabilization techniques (referred to as Hybrid Phase Stabilization or HPS) for the low frequency structural modes. The potential of using HPS for compensating structural mode interaction was previously explored. It was shown that effective time delay was significantly reduced with the use of HPS; however, the HPS design was seen to have greater residual response than a conventional gain stablized design. Additional work performed to advance and refine the HPS design procedure, to further develop residual response metrics as a basis for alternative structural stability specifications, and to develop strategies for validating HPS design and specification concepts in manned simulation is presented. Stabilization design sensitivity to structural uncertainties and aircraft-centered requirements are also assessed.

  10. Quality Evaluation By Acousto-Ultrasonic Testing Of Composites

    NASA Technical Reports Server (NTRS)

    Vary, Alex

    1989-01-01

    Promising nondestructive-testing method based on ultrasonic simulation of stress waves. Report reviews acousto-ultrasonic technology for nondestructive testing. Discusses principles, suggests advanced signal-analysis schemes for development, and presents potential applications. Acousto-ultrasonics applied principally to assess defects in laminated and filament-wound fiber-reinforced composite materials. Technique used to determine variations in such properties as tensile, shear, and flexural strengths and reductions in strength and toughness caused by defects. Also used to evaluate states of cure, porosities, orientation of fibers, volume fractions of fibers, bonding between fibers and matrices, and qualities of interlaminar bonds.

  11. Application of the ultrasonic technique and high-speed filming for the study of the structure of air-water bubbly flows

    SciTech Connect

    Carvalho, R.D.M.; Venturini, O.J.; Tanahashi, E.I.; Neves, F. Jr.; Franca, F.A.

    2009-10-15

    Multiphase flows are very common in industry, oftentimes involving very harsh environments and fluids. Accordingly, there is a need to determine the dispersed phase holdup using noninvasive fast responding techniques; besides, knowledge of the flow structure is essential for the assessment of the transport processes involved. The ultrasonic technique fulfills these requirements and could have the capability to provide the information required. In this paper, the potential of the ultrasonic technique for application to two-phase flows was investigated by checking acoustic attenuation data against experimental data on the void fraction and flow topology of vertical, upward, air-water bubbly flows in the zero to 15% void fraction range. The ultrasonic apparatus consisted of one emitter/receiver transducer and three other receivers at different positions along the pipe circumference; simultaneous high-speed motion pictures of the flow patterns were made at 250 and 1000 fps. The attenuation data for all sensors exhibited a systematic interrelated behavior with void fraction, thereby testifying to the capability of the ultrasonic technique to measure the dispersed phase holdup. From the motion pictures, basic gas phase structures and different flows patterns were identified that corroborated several features of the acoustic attenuation data. Finally, the acoustic wave transit time was also investigated as a function of void fraction. (author)

  12. Testing aspects of advanced coherent electron cooling technique

    SciTech Connect

    Litvinenko, V.; Jing, Y.; Pinayev, I.; Wang, G.; Samulyak, R.; Ratner, D.

    2015-05-03

    An advanced version of the Coherent-electron Cooling (CeC) based on the micro-bunching instability was proposed. This approach promises significant increase in the bandwidth of the CeC system and, therefore, significant shortening of cooling time in high-energy hadron colliders. In this paper we present our plans of simulating and testing the key aspects of this proposed technique using the set-up of the coherent-electron-cooling proof-of-principle experiment at BNL.

  13. Techniques and software tools for estimating ultrasonic signal-to-noise ratios

    NASA Astrophysics Data System (ADS)

    Chiou, Chien-Ping; Margetan, Frank J.; McKillip, Matthew; Engle, Brady J.; Roberts, Ronald A.

    2016-02-01

    At Iowa State University's Center for Nondestructive Evaluation (ISU CNDE), the use of models to simulate ultrasonic inspections has played a key role in R&D efforts for over 30 years. To this end a series of wave propagation models, flaw response models, and microstructural backscatter models have been developed to address inspection problems of interest. One use of the combined models is the estimation of signal-to-noise ratios (S/N) in circumstances where backscatter from the microstructure (grain noise) acts to mask sonic echoes from internal defects. Such S/N models have been used in the past to address questions of inspection optimization and reliability. Under the sponsorship of the National Science Foundation's Industry/University Cooperative Research Center at ISU, an effort was recently initiated to improve existing research-grade software by adding graphical user interface (GUI) to become user friendly tools for the rapid estimation of S/N for ultrasonic inspections of metals. The software combines: (1) a Python-based GUI for specifying an inspection scenario and displaying results; and (2) a Fortran-based engine for computing defect signal and backscattered grain noise characteristics. The latter makes use of several models including: the Multi-Gaussian Beam Model for computing sonic fields radiated by commercial transducers; the Thompson-Gray Model for the response from an internal defect; the Independent Scatterer Model for backscattered grain noise; and the Stanke-Kino Unified Model for attenuation. The initial emphasis was on reformulating the research-grade code into a suitable modular form, adding the graphical user interface and performing computations rapidly and robustly. Thus the initial inspection problem being addressed is relatively simple. A normal-incidence pulse/echo immersion inspection is simulated for a curved metal component having a non-uniform microstructure, specifically an equiaxed, untextured microstructure in which the average

  14. Microstructural evolution and surface properties of nanostructured Cu-based alloy by ultrasonic nanocrystalline surface modification technique

    NASA Astrophysics Data System (ADS)

    Amanov, Auezhan; Cho, In-Sik; Pyun, Young-Sik

    2016-12-01

    A nanostructured surface layer with a thickness of about 180 μm was successfully produced in Cu-based alloy using an ultrasonic nanocrystalline surface modification (UNSM) technique. Cu-based alloy was sintered onto low carbon steel using a powder metallurgy (P/M) method. Transmission electron microscope (TEM) characterization revealed that the severe plastic deformation introduced by UNSM technique resulted in nano-sized grains in the topmost surface layer and deformation twins. It was also found by atomic force microscope (AFM) observations that the UNSM technique provides a significant reduction in number of interconnected pores. The effectiveness of nanostructured surface layer on the tribological and micro-scratch properties of Cu-based alloy specimens was investigated using a ball-on-disk tribometer and micro-scratch tester, respectively. Results exhibited that the UNSM-treated specimen led to an improvement in tribological and micro-scratch properties compared to that of the sintered specimen, which may be attributed to the presence of nanostructured surface layer having an increase in surface hardness and reduction in surface roughness. The findings from this study are expected to be implemented to the automotive industry, in particular connected rod bearings and bushings in order to increase the efficiency and performance of internal combustion engines (ICEs).

  15. Model for estimating the penetration depth limit of the time-reversed ultrasonically encoded optical focusing technique

    PubMed Central

    Jang, Mooseok; Ruan, Haowen; Judkewitz, Benjamin; Yang, Changhuei

    2014-01-01

    The time-reversed ultrasonically encoded (TRUE) optical focusing technique is a method that is capable of focusing light deep within a scattering medium. This theoretical study aims to explore the depth limits of the TRUE technique for biological tissues in the context of two primary constraints – the safety limit of the incident light fluence and a limited TRUE’s recording time (assumed to be 1 ms), as dynamic scatterer movements in a living sample can break the time-reversal scattering symmetry. Our numerical simulation indicates that TRUE has the potential to render an optical focus with a peak-to-background ratio of ~2 at a depth of ~103 mm at wavelength of 800 nm in a phantom with tissue scattering characteristics. This study sheds light on the allocation of photon budget in each step of the TRUE technique, the impact of low signal on the phase measurement error, and the eventual impact of the phase measurement error on the strength of the TRUE optical focus. PMID:24663917

  16. Ultrasonic Evaluation and Imaging

    SciTech Connect

    Crawford, Susan L.; Anderson, Michael T.; Diaz, Aaron A.; Larche, Michael R.; Prowant, Matthew S.; Cinson, Anthony D.

    2015-10-01

    Ultrasonic evaluation of materials for material characterization and flaw detection is as simple as manually moving a single-element probe across a speci-men and looking at an oscilloscope display in real time or as complex as automatically (under computer control) scanning a phased-array probe across a specimen and collecting encoded data for immediate or off-line data analyses. The reliability of the results in the second technique is greatly increased because of a higher density of measurements per scanned area and measurements that can be more precisely related to the specimen geometry. This chapter will briefly discuss applications of the collection of spatially encoded data and focus primarily on the off-line analyses in the form of data imaging. Pacific Northwest National Laboratory (PNNL) has been involved with as-sessing and advancing the reliability of inservice inspections of nuclear power plant components for over 35 years. Modern ultrasonic imaging techniques such as the synthetic aperture focusing technique (SAFT), phased-array (PA) technolo-gy and sound field mapping have undergone considerable improvements to effec-tively assess and better understand material constraints.

  17. Recent Advances in Techniques for Hyperspectral Image Processing

    NASA Technical Reports Server (NTRS)

    Plaza, Antonio; Benediktsson, Jon Atli; Boardman, Joseph W.; Brazile, Jason; Bruzzone, Lorenzo; Camps-Valls, Gustavo; Chanussot, Jocelyn; Fauvel, Mathieu; Gamba, Paolo; Gualtieri, Anthony; Marconcini, Mattia; Tilton, James C.; Trianni, Giovanna

    2009-01-01

    Imaging spectroscopy, also known as hyperspectral imaging, has been transformed in less than 30 years from being a sparse research tool into a commodity product available to a broad user community. Currently, there is a need for standardized data processing techniques able to take into account the special properties of hyperspectral data. In this paper, we provide a seminal view on recent advances in techniques for hyperspectral image processing. Our main focus is on the design of techniques able to deal with the highdimensional nature of the data, and to integrate the spatial and spectral information. Performance of the discussed techniques is evaluated in different analysis scenarios. To satisfy time-critical constraints in specific applications, we also develop efficient parallel implementations of some of the discussed algorithms. Combined, these parts provide an excellent snapshot of the state-of-the-art in those areas, and offer a thoughtful perspective on future potentials and emerging challenges in the design of robust hyperspectral imaging algorithms

  18. Investigation of nanocrystalline copper sulfide Cu 7S 4 fabricated by ultrasonic radiation technique

    NASA Astrophysics Data System (ADS)

    Behboudnia, M.; Khanbabaee, B.

    2007-06-01

    In this paper, we reported the preparation of non-stoichiometric copper sulfide Cu 7S 4 nanocrystalline by ultrasonic irradiation in ethylenediamine solvent system mixed with a complexing agent of 1-decanthiol, using sulfur powder and copper nitrate as reactants under normal laboratory conditions. X-ray diffraction (XRD) pattern indicates that the products are nanocrystallites in monoclinic structure. Scanning electron microscope (SEM) images display that the product consists of nanocrystallites of about 20 nm which aggregated in the form of polydispersive nanoclusters with sizes in the range of 150-300 nm. Energy-dispersive X-ray analysis (EDAX) shows that the products are absolutely pure and atomic percentage ratio of Cu to S is about 60:40. UV-vis absorption spectroscopy of the as-prepared particles reveal an energy band gap of about 2.54 eV; compared to 2 eV corresponding to its bulk value; a blue shift of about 0.54 eV has been observed, which is understood as quantum size effect due to three-dimensional confinement of electrons and holes in a small volume.

  19. Advanced IMCW Lidar Techniques for ASCENDS CO2 Column Measurements

    NASA Astrophysics Data System (ADS)

    Campbell, Joel; lin, bing; nehrir, amin; harrison, fenton; obland, michael

    2015-04-01

    Global atmospheric carbon dioxide (CO2) measurements for the NASA Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) space mission are critical for improving our understanding of global CO2 sources and sinks. Advanced Intensity-Modulated Continuous-Wave (IM-CW) lidar techniques are investigated as a means of facilitating CO2 measurements from space to meet the ASCENDS measurement requirements. In recent numerical, laboratory and flight experiments we have successfully used the Binary Phase Shift Keying (BPSK) modulation technique to uniquely discriminate surface lidar returns from intermediate aerosol and cloud contamination. We demonstrate the utility of BPSK to eliminate sidelobes in the range profile as a means of making Integrated Path Differential Absorption (IPDA) column CO2 measurements in the presence of optically thin clouds, thereby eliminating the need to correct for sidelobe bias errors caused by the clouds. Furthermore, high accuracy and precision ranging to the surface as well as to the top of intermediate cloud layers, which is a requirement for the inversion of column CO2 number density measurements to column CO2 mixing ratios, has been demonstrated using new hyperfine interpolation techniques that takes advantage of the periodicity of the modulation waveforms. This approach works well for both BPSK and linear swept-frequency modulation techniques. The BPSK technique under investigation has excellent auto-correlation properties while possessing a finite bandwidth. A comparison of BPSK and linear swept-frequency is also discussed in this paper. These results are extended to include Richardson-Lucy deconvolution techniques to extend the resolution of the lidar beyond that implied by limit of the bandwidth of the modulation.

  20. Aesthetic Lateral Canthoplasty Using Tarso-Conjunctival Advancement Technique.

    PubMed

    Lee, Eun Jung; Lew, Dae Hyun; Song, Seung Han; Lee, Myung Chul

    2017-01-01

    Reduced horizontal length of the palpebral fissure is a distinctive characteristic of Asian eyelids, and aesthetic lateral canthal lengthening techniques have been performed for a refinement. The aim of this study is to describe a novel lateral canthoplasty using tarso-conjunctival advancement with a lid margin splitting procedure on the upper eyelids and to report the postoperative results. From December 2011 to June 2014, patients who underwent lateral canthoplasty using the tarso-conjunctival advancement procedure for aesthetic purposes were reviewed retrospectively. The predictor variables were grouped into demographic and operative categories. The primary outcome variables were the distances from the mid-pupillary line to the lateral canthus and the horizontal length of the palpebral aperture (distance from the medial to lateral canthus). Data analyses were performed using descriptive and univariate statistics. Patients who showed increment in objective measurements were considered significant. Aesthetic appearance was also evaluated based on pre- and postoperative clinical photographs. A total of 45 patients were enrolled in this study. Both the distance from the mid-pupil to the lateral canthus (ΔDpupil-lateral; 2.78 ± 0.54 mm, P <0.05) and the palpebral aperture horizontal length (ΔDmedial-lateral 2.93 ± 0.81 mm, P <0.05) increased significantly from pre- to postoperative state. All the patients demonstrated satisfactory results aesthetically during the follow-up. The tarso-conjunctival advancement technique for lateral canthoplasty produced satisfactory aesthetic results with an enlarged palpebral aperture. Future research is required to fully delineate the risk of possible complications, including injury to the eyelashes and meibomian glands.

  1. The Inter-Mammary Sticky Roll: A Novel Technique for Securing a Doppler Ultrasonic Probe to the Precordium for Venous Air Embolism Detection

    PubMed Central

    Wali, Arvin R; Gabel, Brandon C; Khalessi, Alexander A; Sang U, Hoi; Drummond, John C

    2016-01-01

    Venous air embolism is a devastating and potentially life-threatening complication that can occur during neurosurgical procedures. We report the development and use of the “inter-mammary sticky roll,” a technique to reliably secure a precordial Doppler ultrasonic probe to the chest wall during neurosurgical cases that require lateral decubitus positioning. We have found that this noninvasive technique is safe, and effectively facilitates a constant Doppler signal with no additional risk to the patient. PMID:27625905

  2. The acousto-ultrasonic approach. [for NDE

    NASA Technical Reports Server (NTRS)

    Vary, Alex

    1988-01-01

    The nature and underlying rationale of the acousto-ultrasonic approach is reviewed, needed advanced signal analysis and evaluation methods suggested, and application potentials discussed. Acousto-ultrasonics is an NDE technique combining aspects of acoustic emission methodology with ultrasonic simulation of stress waves. This approach uses analysis of simulated stress waves for detecting and mapping variations of mechanical properties. Unlike most NDE, acousto-ultrasonics is less concerned with flaw detection than with the assessment of the collective effects of various flaws and material anomalies. Acousto-ultrasonics has been applied chiefly to laminated and filament-wound fiber reinforced composites. It has been used to assess the significant strength and toughness reducing effects that can be wrought by combinations of essentially minor flaws and diffuse flaw populations. Acousto-ultrasonics assesses integrated defect states and the resultant variations in properties such as tensile, shear, and flexural strengths and fracture resistance. Matrix cure state, porosity, fiber orientation, fiber volume fraction, fiber-matrix bonding, and interlaminar bond quality are underlying factors.

  3. Enhanced Ultrasonic Characterization of Assemblies,TLL{_}9

    SciTech Connect

    Thomas, G.; Chinn, D.

    2000-02-22

    The solid state bonded joint between two components; called an autoclave bond, is critical to the performance of a weapon system. A nondestructive method to assess the integrity of these joints is needed to certify the weapon for extended life. This project is developing ultrasonic technologies for bond quality assessment. Existing ultrasonic technology easily maps totally unbonded areas in a bond line. As an example, Figure 1 is an ultrasonic image of the bondline in a tensile specimen that was taken from a surrogate autoclave bond. We enhanced this technology to quantify the mechanical properties of a bond. There are situations when a bond interface appears intact by existing inspection methods, but fails under minimal loading. We developed an ultrasonic technique to eliminate this problem and assess the durability of the bond. Our approach is based on advanced signal processing and artificial intelligence techniques that extract information from the ultrasonic signal after it interacts with the bondline. We successfully demonstrated this technique on surrogate samples. We also designed and began assembly of an ultrasonic system to evaluate weapon components. Our next step is to acquire ultrasonic data on real parts and tailor the bond classification algorithm to detect and image defective bond regions.

  4. Double-chop: Modified-chop technique eliminating ultrasonic energy and vacuum for lens fragmentation.

    PubMed

    Kim, Dooho Brian

    2016-10-01

    Ultrasound (US) energy and vacuum are necessary for most nuclear disassembly techniques, but the use of US energy and vacuum poses potential risks to intracameral structures, including the corneal endothelium, iris, zonular fibers, and posterior capsule. A wide range of techniques involve sculpting, chopping, prechopping, and femtosecond laser-assisted fragmentation. However, these techniques are limited by high US energy, high vacuum to grab and hold the lens, additional instrumentation, or cost. A modified chop approach that bypasses the traditional rules of chopping is presented. The approach is not only effective, but also potentially safer than current techniques because it exposes the eye to less US energy, less vacuum, and less intracapsular manipulation.

  5. Novel modified ultrasonication technique for the extraction of lycopene from tomatoes.

    PubMed

    Eh, Alice Lee-Sie; Teoh, Siang-Guan

    2012-01-01

    Lycopene extraction was carried out via the ultrasonic assisted extraction (UAE) with response surface methodology (RSM). Sonication enhanced the efficiency of relative lycopene yield (enhancement of 26% extraction yield of lycopene in 6 replications at 40.0 min, 40.0 °C and 70.0% v/w in the presence of ultrasound), lowered the extraction temperature and shortened the total extraction time. The extraction was applied with the addition of oxygen-free nitrogen flow and change of water route during water bath sonication. The highest relative yield of lycopene obtained was 100% at 45.0 °C with total extraction time of 50.0 min (30:10:10) and ratio of solvent to freeze-dried tomato sample (v/w) of 80.0:1. Optimisation of the lycopene extraction had been performed, giving the average relative lycopene yield of 99% at 45.6 min, 47.6 °C and ratio of solvent to freeze-dried tomato sample (v/w) of 74.4:1. From the optimised model, the average yield of all-trans lycopene obtained was 5.11±0.27 mg/g dry weight. The all-trans lycopene obtained from the high-performance liquid chromatography (HPLC) chromatograms was 96.81±0.81% with 3.19±0.81% of cis-lycopenes. The purity of total-lycopene obtained was 98.27±0.52% with β-carotene constituted 1.73±0.52% of the extract. The current improved, UAE of lycopene from tomatoes with the aid of RSM also enhanced the extraction yield of trans-lycopene by 75.93% compared to optimised conventional method of extraction. Hence, the current, improved UAE of lycopene promotes the extraction yield of lycopene and at the same time, minimises the degradation and isomerisation of lycopene.

  6. Advanced Techniques for Removal of Retrievable Inferior Vena Cava Filters

    SciTech Connect

    Iliescu, Bogdan; Haskal, Ziv J.

    2012-08-15

    Inferior vena cava (IVC) filters have proven valuable for the prevention of primary or recurrent pulmonary embolism in selected patients with or at high risk for venous thromboembolic disease. Their use has become commonplace, and the numbers implanted increase annually. During the last 3 years, in the United States, the percentage of annually placed optional filters, i.e., filters than can remain as permanent filters or potentially be retrieved, has consistently exceeded that of permanent filters. In parallel, the complications of long- or short-term filtration have become increasingly evident to physicians, regulatory agencies, and the public. Most filter removals are uneventful, with a high degree of success. When routine filter-retrieval techniques prove unsuccessful, progressively more advanced tools and skill sets must be used to enhance filter-retrieval success. These techniques should be used with caution to avoid damage to the filter or cava during IVC retrieval. This review describes the complex techniques for filter retrieval, including use of additional snares, guidewires, angioplasty balloons, and mechanical and thermal approaches as well as illustrates their specific application.

  7. Advanced Synchrotron Techniques at High Pressure Collaborative Access Team (HPCAT)

    NASA Astrophysics Data System (ADS)

    Shen, G.; Sinogeikin, S. V.; Chow, P.; Kono, Y.; Meng, Y.; Park, C.; Popov, D.; Rod, E.; Smith, J.; Xiao, Y.; Mao, H.

    2012-12-01

    High Pressure Collaborative Access Team (HPCAT) is dedicated to advancing cutting-edge, multidisciplinary, high-pressure science and technology using synchrotron radiation at Sector 16 of the Advanced Photon Source (APS) of Argonne National Laboratory. At HPCAT an array of novel x-ray diffraction and spectroscopic techniques has been integrated with high pressure and extreme temperature instrumentation for studies of structure and materials properties at extreme conditions.. HPCAT consists of four active independent beamlines performing a large range of various experiments at extreme conditions. 16BM-B beamline is dedicated to energy dispersive and white Laue X-ray diffraction. The majority of experiments are performed with a Paris-Edinburgh large volume press (to 7GPa and 2500K) and include amorphous and liquid structure measurement, white beam radiography, elastic sound wave velocity measurement of amorphous solid materials, with viscosity and density measurement of liquid being under development. 16BM-D is a monochromatic diffraction beamline for powder and single crystal diffraction at high pressure and high (resistive heating) / low (cryostats) temperature. The additional capabilities include high-resolution powder diffraction and x-ray absorption near edge structure (XANES) spectroscopy. The insertion device beamline of HPCAT has two undulators in canted mode (operating independently) and LN cooled Si monochromators capable of providing a large range of energies. 16IDB is a microdiffraction beamline mainly focusing on high-pressure powder and single crystal diffraction in DAC at high temperatures (double-sided laser heating and resistive heating) and low temperature (various cryostats). The modern instrumentation allows high-quality diffraction at megabar pressures from light element, fast experiments with pulsed laser heating, fast dynamic experiments with Pilatus detector, and so on. 16ID-D beamline is dedicated to x-ray scattering and spectroscopy research

  8. Mechanism of action of the ultrasonic tissue resectors disclosed using high-speed and thermal imaging techniques

    NASA Astrophysics Data System (ADS)

    Verdaasdonck, Rudolf M.; Balgobind, Dennis; van Swol, Christiaan F. P.; Grimbergen, Matthijs C. M.

    1999-05-01

    During surgery, selective resection of soft and hard tissue is obtained using devices based on ultrasound induced cavitation bubbles. Building upon the experience of an earlier study, real-time high speed and thermal imaging techniques were applied to expand the understanding of the mechanism of action in relation to irrigation and aspiration and driving frequency. The Cavitational Ultrasonic Surgical Aspirator (CUSA, Valleylab, Boulder, CO) and the Selector (NMT Neurosciences, UK) equipped with a 2.3 mm hollow titanium needle (frequencies 24 and 35 kHz) were investigated. Close-up photography (1 microsecond(s) ) showed a ring of imploding cavitation bubbles around the rim of the tip which fragmented tissue within a well defined radius. Using Schlieren techniques (10 ns resolution), multiple shock waves generated by imploding cavitation bubbles were observed up to 5 mm inside the transparent tissue without leaving damage. The combined irrigation and aspiration is essential for effective tissue removal. The irrigation provides cooling of the tip and enables cavitation formation. The aspiration draws soft tissue into the area of fragmentation and removes debris. Without irrigation, friction and thermal conduction will result in undesired thermal damage and inefficient tissue removal. The impact of the shock waves and difference in driving frequency are expected to be minimal.

  9. Noncontact, nondestructive elasticity evaluation of sound and demineralized human dental enamel using a laser ultrasonic surface wave dispersion technique

    NASA Astrophysics Data System (ADS)

    Wang, Hsiao-Chuan; Fleming, Simon; Lee, Yung-Chun; Law, Susan; Swain, Michael; Xue, Jing

    2009-09-01

    Laser ultrasonic nondestructive evaluation (NDE) methods have been proposed to replace conventional in vivo dental clinical diagnosis tools that are either destructive or incapable of quantifying the elasticity of human dental enamel. In this work, a laser NDE system that can perform remote measurements on samples of small dimensions is presented. A focused laser line source is used to generate broadband surface acoustic wave impulses that are detected with a simplified optical fiber interferometer. The measured surface wave velocity dispersion spectrum is in turn used to characterize the elasticity of the specimen. The NDE system and the analysis technique are validated with measurements of different metal structures and then applied to evaluate human dental enamel. Artificial lesions are prepared on the samples to simulate different states of enamel elasticity. Measurement results for both sound and lesioned regions, as well as lesions of different severity, are clearly distinguishable from each other and fit well with physical expectations and theoretical value. This is the first time, to the best of our knowledge, that a laser-based surface wave velocity dispersion technique is successfully applied on human dental enamel, demonstrating the potential for noncontact, nondestructive in vivo detection of the development of carious lesions.

  10. Push-out bond strength of two root-end filling materials in root-end cavities prepared by Er,Cr:YSGG laser or ultrasonic technique.

    PubMed

    Shokouhinejad, Noushin; Razmi, Hasan; Fekrazad, Reza; Asgary, Saeed; Neshati, Ammar; Assadian, Hadi; Kheirieh, Sanam

    2012-12-01

    This study compared the push-out bond strength of mineral trioxide aggregate (MTA) and a new endodontic cement (NEC) as root-end filling materials in root-end cavities prepared by ultrasonic technique (US) or Er,Cr:YSGG laser (L). Eighty single-rooted extracted human teeth were endodontically treated, apicectomised and randomly divided into four following groups (n = 20): US/MTA, US/NEC, L/MTA and L/NEC. In US/MTA and US/NEC groups, root-end cavities were prepared with ultrasonic retrotip and filled with MTA and NEC, respectively. In L/MTA and L/NEC groups, root-end cavities were prepared using Er,Cr:YSGG laser and filled with MTA and NEC, respectively. Each root was cut apically to create a 2 mm-thick root slice for measurement of bond strength using a universal testing machine. Then, all slices were examined to determine the mode of bond failure. Data were analysed using two-way anova. Root-end filling materials showed significantly higher bond strength in root-end cavities prepared using ultrasonic technique (US/MTA and US/NEC) (P < 0.001). The bond strengths of MTA and NEC did not differ significantly. The failure modes were mainly adhesive for MTA, but cohesive for NEC. In conclusion, bond strengths of MTA and NEC to root-end cavities were comparable and higher in ultrasonically prepared cavities.

  11. Reconstruction of wave features in wind-driven water film flow using ultrasonic pulse-echo technique

    NASA Astrophysics Data System (ADS)

    Liu, Yang; Bond, Leonard J.; Hu, Hui

    2016-02-01

    Aircraft operating in weather conditions that can cause glaze icing face the risk of performance degradation, and increased costs in de-icing procedures. The water run-back in glaze ice accretion can redistribute the impinging water mass and disturb the local flow field, and hence, affect the morphology of ice accretion. Understanding the mechanism of the surface water film transportation is important and challenging, and critical to enabling improvement in the modeling of glaze icing. In this study, an ultrasonic multi-transducer (sparse array) pulse-echo (UMTPE) technique was developed to measure thin film thickness fluctuation. The technical basis for UMTPE technique and the factors that influence the measurements are described. The UMTPE technique was configured to provide time-resolved multi-point thickness measurements. Quantitative measurements of the wind-driven water film flow are achieved by using the UMTPE technique. Point-wise thickness variations can be obtained from each individual channel in the UMTPE system. Span-wise thickness profile can be derived by interpolating the point-wise measurements. The span-wise thickness profiles can be expanded in time domain, which shows the overall flow structures. The velocity of surface wave features is derived by performing a cross-correlation of the upstream and downstream thickness variations, which is then used to transform the temporal thickness fluctuation into the spatial wave structures. The time-resolved spatial flow structures are obtained by applying the transformation along time axis, which present more details of wave structures and the evolution of wave features.

  12. Advanced Fibre Bragg Grating and Microfibre Bragg Grating Fabrication Techniques

    NASA Astrophysics Data System (ADS)

    Chung, Kit Man

    Fibre Bragg gratings (FBGs) have become a very important technology for communication systems and fibre optic sensing. Typically, FBGs are less than 10-mm long and are fabricated using fused silica uniform phase masks which become more expensive for longer length or non-uniform pitch. Generally, interference UV laser beams are employed to make long or complex FBGs, and this technique introduces critical precision and control issues. In this work, we demonstrate an advanced FBG fabrication system that enables the writing of long and complex gratings in optical fibres with virtually any apodisation profile, local phase and Bragg wavelength using a novel optical design in which the incident angles of two UV beams onto an optical fibre can be adjusted simultaneously by moving just one optical component, instead of two optics employed in earlier configurations, to vary the grating pitch. The key advantage of the grating fabrication system is that complex gratings can be fabricated by controlling the linear movements of two translation stages. In addition to the study of advanced grating fabrication technique, we also focus on the inscription of FBGs written in optical fibres with a cladding diameter of several ten's of microns. Fabrication of microfibres was investigated using a sophisticated tapering method. We also proposed a simple but practical technique to filter out the higher order modes reflected from the FBG written in microfibres via a linear taper region while the fundamental mode re-couples to the core. By using this technique, reflection from the microfibre Bragg grating (MFBG) can be effectively single mode, simplifying the demultiplexing and demodulation processes. MFBG exhibits high sensitivity to contact force and an MFBG-based force sensor was also constructed and tested to investigate their suitability for use as an invasive surgery device. Performance of the contact force sensor packaged in a conforming elastomer material compares favourably to one

  13. Ultrasonic Phased Array Technique for Accurate Flaw Sizing in Dissimilar Metal Welds

    SciTech Connect

    Jonathan D Buttram

    2005-03-11

    Described is a manual,portable non-destructive technique to determine the through wall height of cracks present in dissimilar metal welds used in the primary coolling systems of pressure water and boiler light water reactors. Current manual methods found in industry have proven not to exhibit the sizing accuracy required by ASME inspection requirement. The technique described demonstrated an accuracy approximately three times that required to ASME Section XI, Appendix 8 qualification.

  14. Advanced Cytologic Techniques for the Detection of Malignant Pancreatobiliary Strictures

    PubMed Central

    Moreno Luna, Laura E.; Kipp, Benjamin; Halling, Kevin C.; Sebo, Thomas J.; Kremers., Walter K.; Roberts, Lewis R.; Barr Fritcher, Emily G.; Levy, Michael J.; Gores, Gregory J.

    2006-01-01

    Background & Aims Two advanced cytologic techniques for detecting aneuploidy, digital image analysis (DIA) and fluorescence in situ hybridization (FISH) have recently been developed to help identify malignant pancreatobiliary strictures. The aim of this study was to assess the clinical utility of cytology, DIA, and FISH for the identification of malignant pancreatobiliary strictures. Methods Brush cytologic specimens from 233 consecutive patients undergoing ERCP for pancreatobiliary strictures were examined by all three techniques. Strictures were stratified as proximal (n=33) or distal (n=114) based on whether they occurred above or below the cystic duct, respectively. Strictures in patients with PSC (n=86) were analyzed separately. Results Despite the stratification, the performances of the tests were similar. Routine cytology has a low sensitivity (5–20%) but 100% specificity. Because of the high specificity for cytology, we assessed the performance of the other tests when routine cytology was negative. In this clinical context, FISH had an increased sensitivity (35–60%) when assessing for chromosomal gains (polysomy) while preserving the specificity of cytology. The sensitivity and specificity of DIA was intermediate as compared to routine cytology and FISH, but was additive to FISH values demonstrating only trisomy of chromosome 7 or chromosome 3. Conclusions These findings suggest that FISH and DIA increase the sensitivity for the diagnosis of malignant pancreatobiliary tract strictures over that obtained by conventional cytology while maintaining an acceptable specificity. PMID:17030177

  15. Development of calibration techniques for ultrasonic hydrophone probes in the frequency range from 1 to 100 MHz

    NASA Astrophysics Data System (ADS)

    Umchid, Sumet

    The primary objective of this research was to develop and optimize the calibration techniques for ultrasonic hydrophone probes used in acoustic field measurements up to 100 MHz. A dependable, 100 MHz calibration method was necessary to examine the behavior of a sub-millimeter spatial resolution fiber optic (FO) sensor and assess the need for such a sensor as an alternative tool for high frequency characterization of ultrasound fields. Also, it was of interest to investigate the feasibility of using FO probes in high intensity fields such as those employed in HIFU (High Intensity Focused Ultrasound) applications. In addition to the development of a novel, 100 MHz calibration technique the innovative elements of this research include implementation of a prototype FO sensor with an active diameter of about 10 hum that exhibits uniform sensitivity over the considered frequency range and does not require any spatial averaging corrections up to about 75 MHz. The calibration technique provided the sensitivity of conventional, finite aperture piezoelectric hydrophone probes as a virtually continuous function of frequency and allowed the verification of the uniformity of the FO sensor frequency response. As anticipated, the overall uncertainty of the calibration was dependent on frequency and determined to be about +/-12% (+/-1 dB) up to 40 MHz, +/-20% (+/-1.5 dB) from 40 to 60 MHz and +/-25% (+/-2 dB) from 60 to 100 MHz. The outcome of this research indicates that once fully developed and calibrated, the combined acousto-optic system will constitute a universal reference tool in the wide, 100 MHz bandwidth.

  16. Recent Advances in Seismic Wavefront Tracking Techniques and Their Applications

    NASA Astrophysics Data System (ADS)

    Sambridge, M.; Rawlinson, N.; Hauser, J.

    2007-12-01

    In observational seismology, wavefront tracking techniques are becoming increasingly popular as a means of predicting two point traveltimes and their associated paths. Possible applications include reflection migration, earthquake relocation and seismic tomography at a wide variety of scales. Compared with traditional ray based techniques such as shooting and bending, wavefront tracking has the advantage of locating traveltimes between the source and every point in the medium; in many cases, improved efficiency and robustness; and greater potential for tracking multiple arrivals. In this presentation, two wavefront tracking techniques will be considered: the so-called Fast Marching Method (FMM), and a wavefront construction (WFC) scheme. Over the last several years, FMM has become a mature technique in seismology, with a number of improvements to the underlying theory and the release of software tools that allow it to be used in a variety of applications. At its core, FMM is a grid based solver that implicitly tracks a propagating wavefront by seeking finite difference solutions to the eikonal equation along an evolving narrow band. Recent developments include the use of source grid refinement to improve accuracy, the introduction of a multi-stage scheme to allow reflections and refractions to be tracked in layered media, and extension to spherical coordinates. Implementation of these ideas has led to a number of different applications, including teleseismic tomography, wide-angle reflection and refraction tomography, earthquake relocation, and ambient noise imaging using surface waves. The WFC scheme represents the wavefront surface as a set of points in 6-D phase space; these points are advanced in time using local initial value ray tracing in order to form a sequence of wavefront surfaces that fill the model volume. Surface refinement and simplification techniques inspired by recent developments in computer graphics are used to maintain a fixed density of nodes

  17. Application of ultrasonic technique in nondestructive food quality analysis: a review

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Quality control and safe storage is important in food processing and storage. Composition of food has more effect on quality in terms of nutritional values, functional properties, commercial values and storage conditions of the food products. Traditional analytical techniques that are used for compo...

  18. Low platinum loading for high temperature proton exchange membrane fuel cell developed by ultrasonic spray coating technique

    NASA Astrophysics Data System (ADS)

    Su, Huaneng; Jao, Ting-Chu; Barron, Olivia; Pollet, Bruno G.; Pasupathi, Sivakumar

    2014-12-01

    This paper reports use of an ultrasonic-spray for producing low Pt loadings membrane electrode assemblies (MEAs) with the catalyst coated substrate (CCS) fabrication technique. The main MEA sub-components (catalyst, membrane and gas diffusion layer (GDL)) are supplied from commercial manufacturers. In this study, high temperature (HT) MEAs with phosphoric acid (PA)-doped poly(2,5-benzimidazole) (AB-PBI) membrane are fabricated and tested under 160 °C, hydrogen and air feed 100 and 250 cc min-1 and ambient pressure conditions. Four different Pt loadings (from 0.138 to 1.208 mg cm-2) are investigated in this study. The experiment data are determined by in-situ electrochemical methods such as polarization curve, electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The high Pt loading MEA exhibits higher performance at high voltage operating conditions but lower performances at peak power due to the poor mass transfer. The Pt loading 0.350 mg cm-2 GDE performs the peak power density and peak cathode mass power to 0.339 W cm-2 and 0.967 W mgPt-1, respectively. This work presents impressive cathode mass power and high fuel cell performance for high temperature proton exchange membrane fuel cells (HT-PEMFCs) with low Pt loadings.

  19. The SAFT-UT (synthetic aperture focusing technique for ultrasonic testing) real-time inspection system: Operational principles and implementation

    SciTech Connect

    Hall, T. E.; Reid, L. D.; Doctor, S. R.

    1988-06-01

    This document provides a technical description of the real-time imaging system developed for rapid flaw detection and characterization utilizing the synthetic aperture focusing technique for ultrasonic testing (SAFT-UT). The complete fieldable system has been designed to perform inservice inspection of light-water reactor components. Software was written on a DEC LSI 11/23 computer system to control data collection. The unprocessed data is transferred to a VAX 11/730 host computer to perform data processing and image display tasks. A parallel architecture peripheral to the host computer, referred to as the Real-Time SAFT Processor, rapidly performs the SAFT processing function. From the host's point of view, this device operates on the SAFT data in such a way that one may consider it to be a specialized or SAFT array processor. A guide to SAFT-UT theory and conventions is included, along with a detailed description of the operation of the software, how to install the software, and a detailed hardware description.

  20. Critical evaluation of pulse-echo ultrasonic test method for the determination of setting and mechanical properties of acrylic bone cement: influence of mixing technique.

    PubMed

    Hagan, Christopher P; Orr, John F; Mitchell, Christina A; Dunne, Nicholas J

    2015-02-01

    Currently there is no reliable objective method to quantify the setting properties of acrylic bone cements within an operating theatre environment. Ultrasonic technology can be used to determine the acoustic properties of the polymerising bone cement, which are linked to material properties and provide indications of the physical and chemical changes occurring within the cement. The focus of this study was the critical evaluation of pulse-echo ultrasonic test method in determining the setting and mechanical properties of three different acrylic bone cement when prepared under atmospheric and vacuum mixing conditions. Results indicated that the ultrasonic pulse-echo technique provided a highly reproducible and accurate method of monitoring the polymerisation reaction and indicating the principal setting parameters when compared to ISO 5833 standard, irrespective of the acrylic bone cement or mixing method used. However, applying the same test method to predict the final mechanical properties of acrylic bone cement did not prove a wholly accurate approach. Inhomogeneities within the cement microstructure and specimen geometry were found to have a significant influence on mechanical property predictions. Consideration of all the results suggests that the non-invasive and non-destructive pulse-echo ultrasonic test method is an effective and reliable method for following the full polymerisation reaction of acrylic bone cement in real-time and then determining the setting properties within a surgical theatre environment. However the application of similar technology for predicting the final mechanical properties of acrylic bone cement on a consistent basis may prove difficult.

  1. Laser photoacoustic technique for ultrasonic surface acoustic wave velocity evaluation on porcelain

    NASA Astrophysics Data System (ADS)

    Qian, K.; Tu, S. J.; Gao, L.; Xu, J.; Li, S. D.; Yu, W. C.; Liao, H. H.

    2016-10-01

    A laser photoacoustic technique has been developed to evaluate the surface acoustic wave (SAW) velocity of porcelain. A Q-switched Nd:YAG laser at 1064 nm was focused by a cylindrical lens to initiate broadband SAW impulses, which were detected by an optical fiber interferometer with high spatial resolution. Multiple near-field surface acoustic waves were observed on the sample surface at various locations along the axis perpendicular to the laser line source as the detector moved away from the source in the same increments. The frequency spectrum and dispersion curves were obtained by operating on the recorded waveforms with cross-correlation and FFT. The SAW phase velocities of the porcelain of the same source are similar while they are different from those of different sources. The marked differences of Rayleigh phase velocities in our experiment suggest that this technique has the potential for porcelain identification.

  2. Alternative technique in atypical spinal decompression: the use of the ultrasonic scalpel in paediatric achondroplasia.

    PubMed

    Woodacre, Timothy; Sewell, Matthew; Clarke, Andrew J; Hutton, Mike

    2016-06-10

    Spinal stenosis can be a very disabling condition. Surgical decompression carries a risk of dural tear and neural injury, which is increased in patients with severe stenosis or an atypical anatomy. We present an unusual case of symptomatic stenosis secondary to achondroplasia presenting in a paediatric patient, and highlight a new surgical technique used to minimise the risk of dural and neural injury during decompression.

  3. Quantitative comparison of calcium hydroxide removal by EndoActivator, ultrasonic and ProTaper file agitation techniques: an in vitro study.

    PubMed

    Khaleel, Huda Yasir; Al-Ashaw, Ahmed Jawad; Yang, Yan; Pang, Ai-hui; Ma, Jing-zhi

    2013-02-01

    Calcium hydroxide (CH) dressing residues can compromise endodontic sealing. This study aimed to evaluate the amount of remaining CH in root canals after mechanical removal by four groups of irrigation techniques including needle irrigation only, ProTaper file, EndoActivator, and ultrasonic file. Fifteen extracted single-rooted teeth were collected and used for all four groups. The samples were firstly prepared by ProTaper rotary instruments, and then sectioned longitudinally through the long axis of the root canals, followed by final reassembling by wires. CH was kept in the canals for 7 days setting. The removal procedure began with 5 mL of 2.5% sodium hypochlorite (NaOCl) followed by 1 mL of 17% ethylenediaminetetraacetic acid and a final irrigation with 5 mL of 2.5% NaOCl solution for all groups. No additional agitation of the irrigant was performed in group 1, while agitation for 20 s between irrigants was done with F2 ProTaper rotary file in group 2, EndoActivator with tip size 25/.04 in group 3 and by an ultrasonic file 25/.02 in group 4. The total activation time was 60 s. The roots were then disassembled and captured by digital camera. The ratio of CH coated surface area to the surface area of the whole canal as well as each third of the canal was calculated. The data were statistically analyzed by one-way ANOVA using post hoc Tukey test. Results showed that none of the four techniques could remove all CH. No significant difference was found between EndoActivator and ultrasonic techniques. However, they both removed significantly more CH than ProTaper and needle irrigation (P=0.0001). In conclusion, the sonic and ultrasonic agitation techniques were more effective in removing intracanal medicaments than the ProTaper rotary file and needle irrigation in all thirds of the canal.

  4. Identification of active sonochemical zones in a triple frequency ultrasonic reactor via physical and chemical characterization techniques.

    PubMed

    Tiong, T Joyce; Liew, Derick K L; Gondipon, Ramona C; Wong, Ryan W; Loo, Yuen Ling; Lok, Matthew S T; Manickam, Sivakumar

    2017-03-01

    Coupling multiple frequencies in ultrasonic systems is one of the highly desired area of research for sonochemists, as it is known for producing synergistic effects on various ultrasonic reactions. In this study, the characteristics of a hexagonal-shaped triple frequency ultrasonic reactor with the combination frequencies of 28, 40 and 70kHz were studied. The results showed that uniform temperature increment was achieved throughout the reactor at all frequency combinations. On the other hand, sonochemiluminescence emission and degradation rate of Rhodamine B varies throughout different areas of the reactor, indicating the presence of acoustic 'hot spots' at certain areas of the reactor. Also, coupling dual and triple frequencies showed a decrease in the hydroxyl radical (OH) production, suggesting probable wave cancelling effect in the system. The results can therefore be served as a guide to optimize the usage of a triple frequency ultrasonic reactor for future applications.

  5. Ultrasonic Nondestructive Characterization of Adhesive Bonds

    NASA Technical Reports Server (NTRS)

    Qu, Jianmin

    1999-01-01

    Adhesives and adhesive joints are widely used in various industrial applications to reduce weight and costs, and to increase reliability. For example, advances in aerospace technology have been made possible, in part, through the use of lightweight materials and weight-saving structural designs. Joints, in particular, have been and continue to be areas in which weight can be trimmed from an airframe through the use of novel attachment techniques. In order to save weight over traditional riveted designs, to avoid the introduction of stress concentrations associated with rivet holes, and to take full advantage of advanced composite materials, engineers and designers have been specifying an ever-increasing number of adhesively bonded joints for use on airframes. Nondestructive characterization for quality control and remaining life prediction has been a key enabling technology for the effective use of adhesive joints. Conventional linear ultrasonic techniques generally can only detect flaws (delamination, cracks, voids, etc) in the joint assembly. However, more important to structural reliability is the bond strength. Although strength, in principle, cannot be measured nondestructively, a slight change in material nonlinearity may indicate the onset of failure. Furthermore, microstructural variations due to aging or under-curing may also cause changes in the third order elastic constants, which are related to the ultrasonic nonlinear parameter of the polymer adhesive. It is therefore reasonable to anticipate a correlation between changes in the ultrasonic nonlinear acoustic parameter and the remaining bond strength. It has been observed that higher harmonics of the fundamental frequency are generated when an ultrasonic wave passes through a nonlinear material. It seems that such nonlinearity can be effectively used to characterize bond strength. Several theories have been developed to model this nonlinear effect. Based on a microscopic description of the nonlinear

  6. Quantitative ultrasonic evaluation of engineering properties in metals, composites and ceramics

    NASA Technical Reports Server (NTRS)

    Vary, A.

    1980-01-01

    Ultrasonic technology from the perspective of nondestructive evaluation approaches to material strength prediction and property verification is reviewed. Emergent advanced technology involving quantitative ultrasonic techniques for materials characterization is described. Ultrasonic methods are particularly useful in this area because they involve mechanical elastic waves that are strongly modulated by the same morphological factors that govern mechanical strength and dynamic failure processes. It is emphasized that the technology is in its infancy and that much effort is still required before all the available techniques can be transferred from laboratory to industrial environments.

  7. Advances in Poly(4-aminodiphenylaniline) Nanofibers Preparation by Electrospinning Technique.

    PubMed

    Della Pina, C; Busacca, C; Frontera, P; Antonucci, P L; Scarpino, L A; Sironi, A; Falletta, E

    2016-05-01

    Polyaniline (PANI) nanofibers are drawing a great deal of interest from academia and industry due to their multiple applications, especially in biomedical field. PANI nanofibers were successfully electrospun for the first time by MacDiarmid and co-workers at the beginning of the millennium and since then many efforts have been addressed to improve their quality. However, traditional PANI prepared from aniline monomer shows some drawbacks, such as presence of toxic (i.e., benzidine) and inorganic (salts and metals) co-products, that complicate polymer post-treatment, and low solubility in common organic solvents, making hard its processing by electrospinning technique. Some industrial sectors, such as medical and biomedical, need to employ materials free from toxic and polluting species. In this regard, the oxidative polymerization of N-(4-aminophenyl)aniline, aniline dimer, to produce poly(4-aminodiphenylaniline), P4ADA, a kind of PANI, represents an innovative alternative to the traditional synthesis because the obtained polymer results free from carcinogenic and/or polluting co-products, and, moreover, more soluble than traditional PANI. This latter feature can be exploited to obtain P4ADA nanofibers by electrospinning technique. In this paper we report the advances obtained in the P4ADA nanofibers electrospinnig. A comparison among polyethylene oxide (PEO), polymethyl methacrylate (PMMA) and polystyrene (PS), as the second polymer to facilitate the electrospinning process, is shown. In order to increase the conductivity of P4ADA nanofibers, two strategies were adopted and compared: selective insulating binder removal from electrospun nanofibers by a rinsing tratment, afterwards optimizing the minimum amount of binder necessary for the electrospinning process. Moreover, the effect of PEO/P4ADA weight ratio on the fibers morphology and conductivity was highlighted.

  8. A review of hemorheology: Measuring techniques and recent advances

    NASA Astrophysics Data System (ADS)

    Sousa, Patrícia C.; Pinho, Fernando T.; Alves, Manuel A.; Oliveira, Mónica S. N.

    2016-02-01

    Significant progress has been made over the years on the topic of hemorheology, not only in terms of the development of more accurate and sophisticated techniques, but also in terms of understanding the phenomena associated with blood components, their interactions and impact upon blood properties. The rheological properties of blood are strongly dependent on the interactions and mechanical properties of red blood cells, and a variation of these properties can bring further insight into the human health state and can be an important parameter in clinical diagnosis. In this article, we provide both a reference for hemorheological research and a resource regarding the fundamental concepts in hemorheology. This review is aimed at those starting in the field of hemodynamics, where blood rheology plays a significant role, but also at those in search of the most up-to-date findings (both qualitative and quantitative) in hemorheological measurements and novel techniques used in this context, including technical advances under more extreme conditions such as in large amplitude oscillatory shear flow or under extensional flow, which impose large deformations comparable to those found in the microcirculatory system and in diseased vessels. Given the impressive rate of increase in the available knowledge on blood flow, this review is also intended to identify areas where current knowledge is still incomplete, and which have the potential for new, exciting and useful research. We also discuss the most important parameters that can lead to an alteration of blood rheology, and which as a consequence can have a significant impact on the normal physiological behavior of blood.

  9. Quantitative ultrasonic evaluation of engineering properties in metals, composites, and ceramics

    NASA Technical Reports Server (NTRS)

    Vary, A.

    1980-01-01

    Ultrasonic techniques that have demonstrated potential for material characterization are reviewed. These techniques rely on physical acoustic properties of materials and the interaction of elastic stress waves with morphological factors in the ultrasonic regime. The speed of wave propagation and energy loss by interaction with material microstructure and geometrical factors underlie ultrasonic determination of material properties. Two categories of ultrasonic measurements are discussed: those related to material strengths (e.g., elastic moduli, tensile strength, and fracture toughness) and those related to morphology and material conditions that govern strength and performance (e.g., microstructure, void content, residual stress, fatigue damage). It is shown that large-scale industrial application of ultrasonic NDE will depend on advancement in such areas as theory development, instrumentation, system automation, standardization, and coordination with design.

  10. Evaluation of Ultrasonic Fiber Structure Extraction Technique Using Autopsy Specimens of Liver

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Tadashi; Hirai, Kazuki; Yamada, Hiroyuki; Ebara, Masaaki; Hachiya, Hiroyuki

    2005-06-01

    It is very important to diagnose liver cirrhosis noninvasively and correctly. In our previous studies, we proposed a processing technique to detect changes in liver tissue in vivo. In this paper, we propose the evaluation of the relationship between liver disease and echo information using autopsy specimens of a human liver in vitro. It is possible to verify the function of a processing parameter clearly and to compare the processing result and the actual human liver tissue structure by in vitro experiment. In the results of our processing technique, information that did not obey a Rayleigh distribution from the echo signal of the autopsy liver specimens was extracted depending on changes in a particular processing parameter. The fiber tissue structure of the same specimen was extracted from a number of histological images of stained tissue. We constructed 3D structures using the information extracted from the echo signal and the fiber structure of the stained tissue and compared the two. By comparing the 3D structures, it is possible to evaluate the relationship between the information that does not obey a Rayleigh distribution of the echo signal and the fibrosis structure.

  11. Advanced Techniques for Power System Identification from Measured Data

    SciTech Connect

    Pierre, John W.; Wies, Richard; Trudnowski, Daniel

    2008-11-25

    Time-synchronized measurements provide rich information for estimating a power-system's electromechanical modal properties via advanced signal processing. This information is becoming critical for the improved operational reliability of interconnected grids. A given mode's properties are described by its frequency, damping, and shape. Modal frequencies and damping are useful indicators of power-system stress, usually declining with increased load or reduced grid capacity. Mode shape provides critical information for operational control actions. This project investigated many advanced techniques for power system identification from measured data focusing on mode frequency and damping ratio estimation. Investigators from the three universities coordinated their effort with Pacific Northwest National Laboratory (PNNL). Significant progress was made on developing appropriate techniques for system identification with confidence intervals and testing those techniques on field measured data and through simulation. Experimental data from the western area power system was provided by PNNL and Bonneville Power Administration (BPA) for both ambient conditions and for signal injection tests. Three large-scale tests were conducted for the western area in 2005 and 2006. Measured field PMU (Phasor Measurement Unit) data was provided to the three universities. A 19-machine simulation model was enhanced for testing the system identification algorithms. Extensive simulations were run with this model to test the performance of the algorithms. University of Wyoming researchers participated in four primary activities: (1) Block and adaptive processing techniques for mode estimation from ambient signals and probing signals, (2) confidence interval estimation, (3) probing signal design and injection method analysis, and (4) performance assessment and validation from simulated and field measured data. Subspace based methods have been use to improve previous results from block processing

  12. Pediatric Cardiopulmonary Resuscitation: Advances in Science, Techniques, and Outcomes

    PubMed Central

    Topjian, Alexis A.; Berg, Robert A.; Nadkarni, Vinay M.

    2009-01-01

    More than 25% of children survive to hospital discharge after in-hospital cardiac arrests, and 5% to 10% survive after out-of-hospital cardiac arrests. This review of pediatric cardiopulmonary resuscitation addresses the epidemiology of pediatric cardiac arrests, mechanisms of coronary blood flow during cardiopulmonary resuscitation, the 4 phases of cardiac arrest resuscitation, appropriate interventions during each phase, special resuscitation circumstances, extracorporeal membrane oxygenation cardiopulmonary resuscitation, and quality of cardiopulmonary resuscitation. The key elements of pathophysiology that impact and match the timing, intensity, duration, and variability of the hypoxic-ischemic insult to evidence-based interventions are reviewed. Exciting discoveries in basic and applied-science laboratories are now relevant for specific subpopulations of pediatric cardiac arrest victims and circumstances (eg, ventricular fibrillation, neonates, congenital heart disease, extracorporeal cardiopulmonary resuscitation). Improving the quality of interventions is increasingly recognized as a key factor for improving outcomes. Evolving training strategies include simulation training, just-in-time and just-in-place training, and crisis-team training. The difficult issue of when to discontinue resuscitative efforts is addressed. Outcomes from pediatric cardiac arrests are improving. Advances in resuscitation science and state-of-the-art implementation techniques provide the opportunity for further improvement in outcomes among children after cardiac arrest. PMID:18977991

  13. Recommended advanced techniques for waterborne pathogen detection in developing countries.

    PubMed

    Alhamlan, Fatimah S; Al-Qahtani, Ahmed A; Al-Ahdal, Mohammed N

    2015-02-19

    The effect of human activities on water resources has expanded dramatically during the past few decades, leading to the spread of waterborne microbial pathogens. The total global health impact of human infectious diseases associated with pathogenic microorganisms from land-based wastewater pollution was estimated to be approximately three million disability-adjusted life years (DALY), with an estimated economic loss of nearly 12 billion US dollars per year. Although clean water is essential for healthy living, it is not equally granted to all humans. Indeed, people who live in developing countries are challenged every day by an inadequate supply of clean water. Polluted water can lead to health crises that in turn spread waterborne pathogens. Taking measures to assess the water quality can prevent these potential risks. Thus, a pressing need has emerged in developing countries for comprehensive and accurate assessments of water quality. This review presents current and emerging advanced techniques for assessing water quality that can be adopted by authorities in developing countries.

  14. Dissecting cell adhesion architecture using advanced imaging techniques

    PubMed Central

    Morton, Penny E

    2011-01-01

    Cell adhesion to extracellular matrix proteins or to other cells is essential for the control of embryonic development, tissue integrity, immune function and wound healing. Adhesions are tightly spatially regulated structures containing over one hundred different proteins that coordinate both dynamics and signaling events at these sites. Extensive biochemical and morphological analysis of adhesion types over the past three decades has greatly improved understanding of individual protein contributions to adhesion signaling and, in some cases, dynamics. However, it is becoming increasingly clear that these diverse macromolecular complexes contain a variety of protein sub-networks, as well as distinct sub-domains that likely play important roles in regulating adhesion behavior. Until recently, resolving these structures, which are often less than a micron in size, was hampered by the limitations of conventional light microscopy. However, recent advances in optical techniques and imaging methods have revealed exciting insight into the intricate control of adhesion structure and assembly. Here we provide an overview of the recent data arising from such studies of cell:matrix and cell:cell contact and an overview of the imaging strategies that have been applied to study the intricacies and hierarchy of proteins within adhesions. PMID:21785274

  15. Nanocrystalline materials: recent advances in crystallographic characterization techniques

    PubMed Central

    Ringe, Emilie

    2014-01-01

    Most properties of nanocrystalline materials are shape-dependent, providing their exquisite tunability in optical, mechanical, electronic and catalytic properties. An example of the former is localized surface plasmon resonance (LSPR), the coherent oscillation of conduction electrons in metals that can be excited by the electric field of light; this resonance frequency is highly dependent on both the size and shape of a nanocrystal. An example of the latter is the marked difference in catalytic activity observed for different Pd nanoparticles. Such examples highlight the importance of particle shape in nanocrystalline materials and their practical applications. However, one may ask ‘how are nanoshapes created?’, ‘how does the shape relate to the atomic packing and crystallography of the material?’, ‘how can we control and characterize the external shape and crystal structure of such small nanocrystals?’. This feature article aims to give the reader an overview of important techniques, concepts and recent advances related to these questions. Nucleation, growth and how seed crystallography influences the final synthesis product are discussed, followed by shape prediction models based on seed crystallography and thermodynamic or kinetic parameters. The crystallographic implications of epitaxy and orientation in multilayered, core-shell nanoparticles are overviewed, and, finally, the development and implications of novel, spatially resolved analysis tools are discussed. PMID:25485133

  16. REVIEW ARTICLE: Emission measurement techniques for advanced powertrains

    NASA Astrophysics Data System (ADS)

    Adachi, Masayuki

    2000-10-01

    Recent developments in high-efficiency low-emission powertrains require the emission measurement technologies to be able to detect regulated and unregulated compounds with very high sensitivity and a fast response. For example, levels of a variety of nitrogen compounds and sulphur compounds should be analysed in real time in order to develop aftertreatment systems to decrease emission of NOx for the lean burning powertrains. Also, real-time information on the emission of particulate matter for the transient operation of diesel engines and direct injection gasoline engines is invaluable. The present paper reviews newly introduced instrumentation for such emission measurement that is demanded for the developments in advanced powertrain systems. They include Fourier transform infrared spectroscopy, mass spectrometry and fast response flame ionization detection. In addition, demands and applications of the fuel reformer developments for fuel cell electric vehicles are discussed. Besides the detection methodologies, sample handling techniques for the measurement of concentrations emitted from low emission vehicles for which the concentrations of the pollutants are significantly lower than the concentrations present in ambient air, are also described.

  17. Development of advanced strain diagnostic techniques for reactor environments.

    SciTech Connect

    Fleming, Darryn D.; Holschuh, Thomas Vernon,; Miller, Timothy J.; Hall, Aaron Christopher; Urrea, David Anthony,; Parma, Edward J.,

    2013-02-01

    The following research is operated as a Laboratory Directed Research and Development (LDRD) initiative at Sandia National Laboratories. The long-term goals of the program include sophisticated diagnostics of advanced fuels testing for nuclear reactors for the Department of Energy (DOE) Gen IV program, with the future capability to provide real-time measurement of strain in fuel rod cladding during operation in situ at any research or power reactor in the United States. By quantifying the stress and strain in fuel rods, it is possible to significantly improve fuel rod design, and consequently, to improve the performance and lifetime of the cladding. During the past year of this program, two sets of experiments were performed: small-scale tests to ensure reliability of the gages, and reactor pulse experiments involving the most viable samples in the Annulated Core Research Reactor (ACRR), located onsite at Sandia. Strain measurement techniques that can provide useful data in the extreme environment of a nuclear reactor core are needed to characterize nuclear fuel rods. This report documents the progression of solutions to this issue that were explored for feasibility in FY12 at Sandia National Laboratories, Albuquerque, NM.

  18. Nanocrystalline materials: recent advances in crystallographic characterization techniques.

    PubMed

    Ringe, Emilie

    2014-11-01

    Most properties of nanocrystalline materials are shape-dependent, providing their exquisite tunability in optical, mechanical, electronic and catalytic properties. An example of the former is localized surface plasmon resonance (LSPR), the coherent oscillation of conduction electrons in metals that can be excited by the electric field of light; this resonance frequency is highly dependent on both the size and shape of a nanocrystal. An example of the latter is the marked difference in catalytic activity observed for different Pd nanoparticles. Such examples highlight the importance of particle shape in nanocrystalline materials and their practical applications. However, one may ask 'how are nanoshapes created?', 'how does the shape relate to the atomic packing and crystallography of the material?', 'how can we control and characterize the external shape and crystal structure of such small nanocrystals?'. This feature article aims to give the reader an overview of important techniques, concepts and recent advances related to these questions. Nucleation, growth and how seed crystallography influences the final synthesis product are discussed, followed by shape prediction models based on seed crystallography and thermodynamic or kinetic parameters. The crystallographic implications of epitaxy and orientation in multilayered, core-shell nanoparticles are overviewed, and, finally, the development and implications of novel, spatially resolved analysis tools are discussed.

  19. Experimental characterization of creep damage in a welded steel pipe section using a nonlinear ultrasonic technique

    NASA Astrophysics Data System (ADS)

    Ehrlich, C.; Kim, J.-Y.; Jacobs, L. J.; Qu, J.; Wall, J.

    2012-05-01

    To ensure the long and safe operation of power plants, structural parts must be monitored for damage. In the case of welded steel pipes that maintain high pressures in high temperature environments, a common cause of failure is creep damage. Severe creep damage often occurs in the heat affected zone (HAZ). Previous research has shown that nonlinear acoustic techniques are sensitive to creep damage. This research develops a procedure using longitudinal waves to obtain the nonlinearity parameter on a welded steel pipe in order to detect creep damage. These experiments show higher levels of nonlinearity in the HAZ. Additional measurements on an undamaged, welded sample suggest that the high nonlinearity is due to creep (stresses at a high temperature for extended time) damage and not welding (high temperature only for a short time).

  20. Mechanical-plowing-based high-speed patterning on hard material via advanced-control and ultrasonic probe vibration

    SciTech Connect

    Wang, Zhihua; Zou, Qingze; Tan, Jun; Jiang, Wei

    2013-11-15

    In this paper, we present a high-speed direct pattern fabrication on hard materials (e.g., a tungsten-coated quartz substrate) via mechanical plowing. Compared to other probe-based nanolithography techniques based on chemical- and/or physical-reactions (e.g., the Dip-pen technique), mechanical plowing is meritorious for its low cost, ease of process control, and capability of working with a wide variety of materials beyond conductive and/or soft materials. However, direct patterning on hard material faces two daunting challenges. First, the patterning throughput is ultimately hindered by the “writing” (plowing) speed, which, in turn, is limited by the adverse effects that can be excited/induced during high-speed, and/or large-range plowing, including the vibrational dynamics of the actuation system (the piezoelectric actuator, the cantilever, and the mechanical fixture connecting the cantilever to the actuator), the dynamic cross-axis coupling between different axes of motion, and the hysteresis and the drift effects related to the piezoelectric actuators. Secondly, it is very challenging to directly pattern on ultra-hard materials via plowing. Even with a diamond probe, the line depth of the pattern via continuous plowing on ultra-hard materials such as tungsten, is still rather small (<0.5 nm), particularly when the “writing” speed becomes high. To overcome these two challenges, we propose to utilize a novel iterative learning control technique to achieve precision tracking of the desired pattern during high-speed, large-range plowing, and introduce ultrasonic vibration of the probe in the normal (vertical) direction during the plowing process to enable direct patterning on ultra hard materials. The proposed approach was implemented to directly fabricate patterns on a mask with tungsten coating and quartz substrate. The experimental results demonstrated that a large-size pattern of four grooves (20 μm in length with 300 nm spacing between lines) can be

  1. CTAB assisted growth and characterization of nanocrystalline CuO films by ultrasonic spray pyrolysis technique

    NASA Astrophysics Data System (ADS)

    Singh, Iqbal; Kaur, Gursharan; Bedi, R. K.

    2011-09-01

    An aqueous solution of cupric nitrate trihydrate (Cu(NO 3) 2·3H 2O) modified with cetyltrimetylammonium bromide (CTAB) is used to deposit CuO films on glass substrate by chemical spray pyrolysis technique. The thermal analysis shows that the dried CTAB doped precursor decomposes by an exothermic reaction and suggests that minimum substrate temperature for film deposition should be greater than 270 °C. X-ray diffraction (XRD) studies indicate the formation of monoclinic CuO with preferential orientation along (0 0 2) plane for all film samples. The CTAB used as cationic surfactant in precursor results in the suppression of grain growth in films along the (1 1 0), (0 2 0) and (2 2 0) crystal planes of CuO. Surfactant modified films showed an increase in crystallite size of 14 nm at substrate temperature of 300 °C. The scanning electron micrographs (FESEM) confirm the uniform distribution of facets like grains on the entire area of substrate. CTAB modified films show a significant reduction in the particle agglomeration. Electrical studies of the CuO films deposited at substrate temperature of 300 °C with and without surfactant reveal that the CTAB doping increase the activation energy of conduction by 0.217 eV and room temperature response to ammonia by 9%. The kinetics of the ammonia gas adsorption on the film surface follows the Elovich and Diffusion models.

  2. An ultrasonic technique to measure the depth of burn wounds in humans

    NASA Astrophysics Data System (ADS)

    Yost, William T.; Cantrell, John H.; Hanna, Pamela D.

    1991-06-01

    Whenever ultrasound encounters discontinuity in its medium of propagation, some energy is reflected from the interface. Such reflections or echoes occur when incident energy encounters the front skin, viable/necrotic, and dermis/fat skin tissue interfaces. It was shown that the most probable cause of the viable/necrotic interface is the uncoiling of collagen in the necrotic tissue, which can cause a reflection at the viable/necrotic interface of approximately 10 percent of the wave amplitude, and is approximately the same as that from the other two interfaces noted. The instrument, still in the prototype stage, was designed to detect the various reflections from within the skin layer. It is shown that, by studying the timing between the various echoes, one can use ultrasound as an aid in diagnosing the depth of burned skin tissue in humans. The instrument is a 60-MHz A-scan unit, modified to more easily identify the echoes occurring within the short time interval during which the reflections are received from the skin layers. A high frequency unit was selected so that various transducers could be utilized to optimize the system. Signal conditioning circuits were modified and added to provide an adequate display of the principle reflections expected. The unit was successful in studying burned tissue in pigs and was recently used to study burn wounds in humans. Measurement techniques and preliminary results are presented.

  3. An ultrasonic technique to measure the depth of burn wounds in humans

    NASA Technical Reports Server (NTRS)

    Yost, William T.; Cantrell, John H.; Hanna, Pamela D.

    1991-01-01

    Whenever ultrasound encounters discontinuity in its medium of propagation, some energy is reflected from the interface. Such reflections or echoes occur when incident energy encounters the front skin, viable/necrotic, and dermis/fat skin tissue interfaces. It was shown that the most probable cause of the viable/necrotic interface is the uncoiling of collagen in the necrotic tissue, which can cause a reflection at the viable/necrotic interface of approximately 10 percent of the wave amplitude, and is approximately the same as that from the other two interfaces noted. The instrument, still in the prototype stage, was designed to detect the various reflections from within the skin layer. It is shown that, by studying the timing between the various echoes, one can use ultrasound as an aid in diagnosing the depth of burned skin tissue in humans. The instrument is a 60-MHz A-scan unit, modified to more easily identify the echoes occurring within the short time interval during which the reflections are received from the skin layers. A high frequency unit was selected so that various transducers could be utilized to optimize the system. Signal conditioning circuits were modified and added to provide an adequate display of the principle reflections expected. The unit was successful in studying burned tissue in pigs and was recently used to study burn wounds in humans. Measurement techniques and preliminary results are presented.

  4. ADVANCED TECHNIQUES FOR RESERVOIR SIMULATION AND MODELING OF NONCONVENTIONAL WELLS

    SciTech Connect

    Louis J. Durlofsky; Khalid Aziz

    2004-08-20

    Nonconventional wells, which include horizontal, deviated, multilateral and ''smart'' wells, offer great potential for the efficient management of oil and gas reservoirs. These wells are able to contact larger regions of the reservoir than conventional wells and can also be used to target isolated hydrocarbon accumulations. The use of nonconventional wells instrumented with downhole inflow control devices allows for even greater flexibility in production. Because nonconventional wells can be very expensive to drill, complete and instrument, it is important to be able to optimize their deployment, which requires the accurate prediction of their performance. However, predictions of nonconventional well performance are often inaccurate. This is likely due to inadequacies in some of the reservoir engineering and reservoir simulation tools used to model and optimize nonconventional well performance. A number of new issues arise in the modeling and optimization of nonconventional wells. For example, the optimal use of downhole inflow control devices has not been addressed for practical problems. In addition, the impact of geological and engineering uncertainty (e.g., valve reliability) has not been previously considered. In order to model and optimize nonconventional wells in different settings, it is essential that the tools be implemented into a general reservoir simulator. This simulator must be sufficiently general and robust and must in addition be linked to a sophisticated well model. Our research under this five year project addressed all of the key areas indicated above. The overall project was divided into three main categories: (1) advanced reservoir simulation techniques for modeling nonconventional wells; (2) improved techniques for computing well productivity (for use in reservoir engineering calculations) and for coupling the well to the simulator (which includes the accurate calculation of well index and the modeling of multiphase flow in the wellbore

  5. Weldability and joining techniques for advanced fossil energy system alloys

    SciTech Connect

    Lundin, C.D.; Qiao, C.Y.P.; Liu, W.; Yang, D.; Zhou, G.; Morrison, M.

    1998-05-01

    The efforts represent the concerns for the basic understanding of the weldability and fabricability of the advanced high temperature alloys so necessary to affect increases in the efficiency of the next generation Fossil Energy Power Plants. The effort was divided into three tasks with the first effort dealing with the welding and fabrication behavior of 310HCbN (HR3C), the second task details the studies aimed at understanding the weldability of a newly developed 310TaN high temperature stainless (a modification of 310 stainless) and Task 3 addressed the cladding of austenitic tubing with Iron-Aluminide using the GTAW process. Task 1 consisted of microstructural studies on 310HCbN and the development of a Tube Weldability test which has applications to production welding techniques as well as laboratory weldability assessments. In addition, the evaluation of ex-service 310HCbN which showed fireside erosion and cracking at the attachment weld locations was conducted. Task 2 addressed the behavior of the newly developed 310 TaN modification of standard 310 stainless steel and showed that the weldability was excellent and that the sensitization potential was minimal for normal welding and fabrication conditions. The microstructural evolution during elevated temperature testing was characterized and the second phase particles evolved upon aging were identified. Task 3 details the investigation undertaken to clad 310HCbN tubing with Iron Aluminide and developed welding conditions necessary to provide a crack free cladding. The work showed that both a preheat and a post-heat was necessary for crack free deposits and the effect of a third element on the cracking potential was defined together with the effect of the aluminum level for optimum weldability.

  6. Investigation of joining techniques for advanced austenitic alloys

    SciTech Connect

    Lundin, C.D.; Qiao, C.Y.P.; Kikuchi, Y.; Shi, C.; Gill, T.P.S.

    1991-05-01

    Modified Alloys 316 and 800H, designed for high temperature service, have been developed at Oak Ridge National Laboratory. Assessment of the weldability of the advanced austenitic alloys has been conducted at the University of Tennessee. Four aspects of weldability of the advanced austenitic alloys were included in the investigation.

  7. Prototype Instrument for Noninvasive Ultrasonic Inspection and Indentification of Fluids in Sealed Containers

    SciTech Connect

    Tucker, Brian J.; Diaz, Aaron A.; Eckenrode, Brian A.

    2006-08-01

    Government agencies and homeland security related organizations have identified the need to develop and establish a wide range of unprecedented capabilities for providing scientific and technical forensic services to investigations involving hazardous chemical, biological, and radiological materials, including extremely dangerous chemical and biological warfare agents. Pacific Northwest National Laboratory (PNNL) has developed a prototype portable, hand-held, hazardous materials acoustic inspection prototype that provides noninvasive container interrogation and material identification capabilities using nondestructive ultrasonic velocity and attenuation measurements. Due to the wide variety of fluids as well as container sizes and materials encountered in various law enforcement inspection activities, the need for high measurement sensitivity and advanced ultrasonic measurement techniques were identified. The prototype was developed using a versatile electronics platform, advanced ultrasonic wave propagation methods, and advanced signal processing techniques. This paper primarily focuses on the ultrasonic measurement methods and signal processing techniques incorporated into the prototype. High bandwidth ultrasonic transducers combined with an advanced pulse compression technique allowed researchers to 1) obtain high signal-to-noise ratios and 2) obtain accurate and consistent time-of-flight (TOF) measurements through a variety of highly attenuative containers and fluid media. Results of work conducted in the laboratory have demonstrated that the prototype experimental measurement technique also provided information regarding container properties, which will be utilized in future container-independent measurements of hidden liquids.

  8. Prototype instrument for noninvasive ultrasonic inspection and identification of fluids in sealed containers

    NASA Astrophysics Data System (ADS)

    Tucker, Brian J.; Diaz, Aaron A.; Eckenrode, Brian A.

    2006-05-01

    Government agencies and homeland security related organizations have identified the need to develop and establish a wide range of unprecedented capabilities for providing scientific and technical forensic services to investigations involving hazardous chemical, biological, and radiological materials, including extremely dangerous chemical and biological warfare agents. Pacific Northwest National Laboratory (PNNL) has developed a prototype portable, handheld, hazardous materials acoustic inspection prototype that provides noninvasive container interrogation and material identification capabilities using nondestructive ultrasonic velocity and attenuation measurements. Due to the wide variety of fluids as well as container sizes and materials encountered in various law enforcement inspection activities, the need for high measurement sensitivity and advanced ultrasonic measurement techniques were identified. The prototype was developed using a versatile electronics platform, advanced ultrasonic wave propagation methods, and advanced signal processing techniques. This paper primarily focuses on the ultrasonic measurement methods and signal processing techniques incorporated into the prototype. High bandwidth ultrasonic transducers combined with an advanced pulse compression technique allowed researchers to 1) obtain high signal-to-noise ratios and 2) obtain accurate and consistent time-of-flight (TOF) measurements through a variety of highly attenuative containers and fluid media. Results of work conducted in the laboratory have demonstrated that the prototype experimental measurement technique also provided information regarding container properties, which will be utilized in future container-independent measurements of hidden liquids.

  9. Ultrasonic nondestructive characterization of composites with 3-dimensional architectures

    NASA Technical Reports Server (NTRS)

    Miller, James G.

    1992-01-01

    The development and implementation of advanced composite material systems and their associated technologies are critical for success in the highly competitive world aerospace market. Acceptance of advance production methods and field support of structures made with these new materials require the development of quantitative, cost-effective, inspection methods. The results of quantitative ultrasonic through-transmission imaging of composites with complex three-dimensional architecture using phase-insensitive and phase-sensitive techniques are presented.

  10. Physical interpretation and development of ultrasonic nondestructive evaluation techniques applied to the quantitative characterization of textile composite materials

    NASA Astrophysics Data System (ADS)

    Miller, James G.

    1995-03-01

    In this Progress Report, the author describes the continuing research to explore the feasibility of implementing medical linear array imaging technology as a viable ultrasonic-based nondestructive evaluation method to inspect and characterize complex materials. Images obtained using an unmodified medical ultrasonic imaging system of a bonded aluminum plate sample with a simulated disbond region are presented. The disbond region was produced by adhering a piece of plain white paper to a piece of cellophane tape and applying the paper-tape combination to one of the aluminum plates. Because the area under the paper was not adhesively bonded to the aluminum plate, this arrangement more closely simulates a disbond. Images are also presented for an aluminum plate sample with an epoxy strip adhered to one side to help provide information for the interpretation of the images of the bonded aluminum plate sample containing the disbond region. These images are compared with corresponding conventional ultrasonic contact transducer measurements in order to provide information regarding the nature of the disbonded region. The results of this on-going investigation may provide a step toward the development of a rapid, real-time, and portable method of ultrasonic inspection and characterization based on linear array technology. In Section 2 of this Progress Report, the preparation of the aluminum plate specimens is described. Section 3 describes the method of linear array imaging. Sections 4 and 5 present the linear array images and results from contact transducer measurements, respectively. A discussion of the results are presented in Section 6.

  11. Physical interpretation and development of ultrasonic nondestructive evaluation techniques applied to the quantitative characterization of textile composite materials

    NASA Technical Reports Server (NTRS)

    Miller, James G.

    1995-01-01

    In this Progress Report, the author describes the continuing research to explore the feasibility of implementing medical linear array imaging technology as a viable ultrasonic-based nondestructive evaluation method to inspect and characterize complex materials. Images obtained using an unmodified medical ultrasonic imaging system of a bonded aluminum plate sample with a simulated disbond region are presented. The disbond region was produced by adhering a piece of plain white paper to a piece of cellophane tape and applying the paper-tape combination to one of the aluminum plates. Because the area under the paper was not adhesively bonded to the aluminum plate, this arrangement more closely simulates a disbond. Images are also presented for an aluminum plate sample with an epoxy strip adhered to one side to help provide information for the interpretation of the images of the bonded aluminum plate sample containing the disbond region. These images are compared with corresponding conventional ultrasonic contact transducer measurements in order to provide information regarding the nature of the disbonded region. The results of this on-going investigation may provide a step toward the development of a rapid, real-time, and portable method of ultrasonic inspection and characterization based on linear array technology. In Section 2 of this Progress Report, the preparation of the aluminum plate specimens is described. Section 3 describes the method of linear array imaging. Sections 4 and 5 present the linear array images and results from contact transducer measurements, respectively. A discussion of the results are presented in Section 6.

  12. Laser ultrasonic surface wave inspection of alumina ceramics of varying density

    PubMed

    Kehoe; Coyle; Murray; Flannery; Crean

    2000-03-01

    In this paper, the surface acoustic wave velocity results acquired from the inspection of specially manufactured and characterised alumina ceramic materials are presented. Ultrasonic velocity data of alumina-based ceramics in the range 60-100% theoretical density was generated utilising non-contacting laser-ultrasonic measurements based on laser generation and detection of surface acoustic waves with the objective of creating a routine technique for industrial advanced alumina inspection. With linear fitting the surface acoustic wave velocity data serves as a calibration graph for using laser ultrasonics for routine monitoring of alumina. A second laser ultrasonic technique based on the laser generation and foil transducer detection of surface acoustic waves was used to validate the surface acoustic wave velocities measured by the laser generation/detection technique.

  13. Recent advances in sample preparation techniques for effective bioanalytical methods.

    PubMed

    Kole, Prashant Laxman; Venkatesh, Gantala; Kotecha, Jignesh; Sheshala, Ravi

    2011-01-01

    This paper reviews the recent developments in bioanalysis sample preparation techniques and gives an update on basic principles, theory, applications and possibilities for automation, and a comparative discussion on the advantages and limitation of each technique. Conventional liquid-liquid extraction (LLE), protein precipitation (PP) and solid-phase extraction (SPE) techniques are now been considered as methods of the past. The last decade has witnessed a rapid development of novel sample preparation techniques in bioanalysis. Developments in SPE techniques such as selective sorbents and in the overall approach to SPE, such as hybrid SPE and molecularly imprinted polymer SPE, have been addressed. Considerable literature has been published in the area of solid-phase micro-extraction and its different versions, e.g. stir bar sorptive extraction, and their application in the development of selective and sensitive bioanalytical methods. Techniques such as dispersive solid-phase extraction, disposable pipette extraction and micro-extraction by packed sorbent offer a variety of extraction phases and provide unique advantages to bioanalytical methods. On-line SPE utilizing column-switching techniques is rapidly gaining acceptance in bioanalytical applications. PP sample preparation techniques such as PP filter plates/tubes offer many advantages like removal of phospholipids and proteins in plasma/serum. Newer approaches to conventional LLE techniques (salting-out LLE) are also covered in this review article.

  14. Advanced rehabilitation techniques for the multi-limb amputee.

    PubMed

    Harvey, Zach T; Loomis, Gregory A; Mitsch, Sarah; Murphy, Ian C; Griffin, Sarah C; Potter, Benjamin K; Pasquina, Paul

    2012-01-01

    Advances in combat casualty care have contributed to unprecedented survival rates of battlefield injuries, challenging the field of rehabilitation to help injured service members achieve maximal functional recovery and independence. Nowhere is this better illustrated than in the care of the multiple-limb amputee. Specialized medical, surgical, and rehabilitative interventions are needed to optimize the care of this unique patient population. This article describes lessons learned at Walter Reed National Military Medical Center Bethesda in providing advanced therapy and prosthetics for combat casualties, but provides guidelines for all providers involved in the care of individuals with amputation.

  15. Advanced froth flotation techniques for fine coal cleaning

    SciTech Connect

    Yoon, R.H.; Luttrell, G.H.

    1994-12-31

    Advanced column flotation cells offer many potential advantages for the treatment of fine coal. The most important of these is the ability to achieve high separation efficiencies using only a single stage of processing. Unfortunately, industrial flotation columns often suffer from poor recovery, low throughput and high maintenance requirements as compared to mechanically-agitated conventional cells. These problems can usually be attributed to poorly-designed air sparging systems. This article examines the problems of air sparging in greater detail and offers useful guidelines for designing bubble generators for industrial flotation columns. The application of these principles in the design of a successful advanced fine coal flotation circuit is also presented.

  16. Analytic Syntax: A Technique for Advanced Level Reading

    ERIC Educational Resources Information Center

    Berman, Ruth

    1975-01-01

    The technique explained here can increase a foreign student's awareness of English grammatical and rhetorical structures. Structural paraphrase is a syntactic reformulation of difficult phrases with minimal vocabulary changes. The technique is illustrated and suggestions are given for class presentation. (CHK)

  17. Two-dimensional simulation of the single-sided air-coupled ultrasonic pitch-catch technique for non-destructive testing.

    PubMed

    Delrue, Steven; Van Den Abeele, Koen; Blomme, Erik; Deveugele, Jurgen; Lust, Pieter; Matar, Olivier Bou

    2010-02-01

    Non-contact air-coupled ultrasonic inspection of materials using single-sided access offers interesting possibilities for the development of in-line non-destructive testing (NDT) systems. This contribution reports observations and simulations obtained from a single-sided air-coupled pitch-catch configuration. The pitch-catch technique involves a set-up in which transmitter and receiver are located at the same side of the test object. Sound waves, reflected once or multiple times from the back-wall of the object or refracted by a discontinuity, are recorded and analyzed for visualization. The feasibility of the technique is demonstrated, experimentally, in the case of artificial defects in aluminium samples. Depending on the configuration one or more ultrasonic images of the defect can be observed, their number and relative position containing information about the location of the defect. The experiments are simulated using two distinctive methods. The first simulation is based on a ray tracing (shadow) approach, the second method uses a spectral solution implemented within COMSOL. Both simulation methods allow simple prediction of the response images in experimental conditions with supplementary levels of complexity, which will assist the development and optimization of online inspection techniques.

  18. Recent advances in microscopic techniques for visualizing leukocytes in vivo

    PubMed Central

    Jain, Rohit; Tikoo, Shweta; Weninger, Wolfgang

    2016-01-01

    Leukocytes are inherently motile and interactive cells. Recent advances in intravital microscopy approaches have enabled a new vista of their behavior within intact tissues in real time. This brief review summarizes the developments enabling the tracking of immune responses in vivo. PMID:27239292

  19. Bricklaying Curriculum: Advanced Bricklaying Techniques. Instructional Materials. Revised.

    ERIC Educational Resources Information Center

    Turcotte, Raymond J.; Hendrix, Laborn J.

    This curriculum guide is designed to assist bricklaying instructors in providing performance-based instruction in advanced bricklaying. Included in the first section of the guide are units on customized or architectural masonry units; glass block; sills, lintels, and copings; and control (expansion) joints. The next two units deal with cut,…

  20. Characterization of material deformation and failure responses from ultrasonic measurements

    NASA Astrophysics Data System (ADS)

    Thompson, R. B.

    Recent advances in ultrasonic techniques to characterize the structure of materials are presented. Observable parameters include the velocity, attenuation and scattering of ultrasonic waves and their variation with propagation direction and frequency. Applications are described in which information obtained from such measurements is used to characterize the deformation and failure responses of metals, metal-metal bonds, heavily deformed metal-metal composites and thick, filament-wound composites. In each case, unsolved mechanics problems whose solutions are needed to improve the application results are identified.

  1. Backscattered Electron Microscopy as an Advanced Technique in Petrography.

    ERIC Educational Resources Information Center

    Krinsley, David Henry; Manley, Curtis Robert

    1989-01-01

    Three uses of this method with sandstone, desert varnish, and granite weathering are described. Background information on this technique is provided. Advantages of this type of microscopy are stressed. (CW)

  2. Advanced Statistical Signal Processing Techniques for Landmine Detection Using GPR

    DTIC Science & Technology

    2014-07-12

    based ground penetrating radars for the detection of subsurface objects that are low in metal content and hard to detect. The derived techniques...penetrating radars for the detection of subsurface objects that are low in metal content and hard to detect. The derived techniques include the exploitation...5.00 4.00 3.00 9.00 T. Glenn, J. Wilson, D. Ho. A MULTIMODAL MATCHING PURSUITS DISSIMILARITY MEASURE APPLIED TO LANDMINE/CLUTTER DISCRIMINATION

  3. The characteristics of novel bimodal Ag-TiO2 nanoparticles generated by hybrid laser-ultrasonic technique

    NASA Astrophysics Data System (ADS)

    Hamad, Abubaker; Li, Lin; Liu, Zhu; Zhong, Xiang Li; Burke, Grace; Wang, Tao

    2016-04-01

    Silver-titania (Ag-TiO2) nanoparticles with smaller Ag nanoparticles attached to larger TiO2 nanoparticles were generated by hybrid ultrasonic vibration and picosecond laser ablation of Ag and Ti bulk targets in deionised water, for the first time. The laser has a wavelength of 1064 nm and a pulse duration of 10 ps. It was observed that without the ultrasonic vibration, Ag and TiO2 nanoparticles did not combine, thus the role of ultrasonic vibration is essential. In addition, colloidal TiO2 and Ag nanoparticles were generated separately for comparison under the same laser beam characteristics and process conditions. The absorption spectra of colloidal Ag-TiO2 cluster nanoparticles were examined by UV-Vis spectroscopy, and size distribution was characterised using transmission electron microscopy. The morphology and composition of Ag-TiO2 nanoparticles were examined using scanning transmission electron microscopy in high-angle annular dark field, and energy-dispersive X-ray spectroscopy. The crystalline structures were investigated by X-ray diffraction. The size of larger TiO2 particles was in the range 30-150 nm, and the smaller-sized Ag nanoparticles attached to the TiO2 was mainly in the range of 10-15 nm. The yield is more than 50 % with the remaining nanoparticles in the form of uncombined Ag and TiO2. The nanoparticles generated had strong antibacterial effects as tested against E. coli. A discussion is given on the role of ultrasonic vibration in the formation of Ag-TiO2 hybrid nanoparticles by picosecond laser ablation.

  4. Electroextraction and electromembrane extraction: Advances in hyphenation to analytical techniques

    PubMed Central

    Oedit, Amar; Ramautar, Rawi; Hankemeier, Thomas

    2016-01-01

    Electroextraction (EE) and electromembrane extraction (EME) are sample preparation techniques that both require an electric field that is applied over a liquid‐liquid system, which enables the migration of charged analytes. Furthermore, both techniques are often used to pre‐concentrate analytes prior to analysis. In this review an overview is provided of the body of literature spanning April 2012–November 2015 concerning EE and EME, focused on hyphenation to analytical techniques. First, the theoretical aspects of concentration enhancement in EE and EME are discussed to explain extraction recovery and enrichment factor. Next, overviews are provided of the techniques based on their hyphenation to LC, GC, CE, and direct detection. These overviews cover the compounds and matrices, experimental aspects (i.e. donor volume, acceptor volume, extraction time, extraction voltage, and separation time) and the analytical aspects (i.e. limit of detection, enrichment factor, and extraction recovery). Techniques that were either hyphenated online to analytical techniques or show high potential with respect to online hyphenation are highlighted. Finally, the potential future directions of EE and EME are discussed. PMID:26864699

  5. Advanced millimeter-wave security portal imaging techniques

    NASA Astrophysics Data System (ADS)

    Sheen, David M.; Bernacki, Bruce E.; McMakin, Douglas L.

    2012-03-01

    Millimeter-wave (mm-wave) imaging is rapidly gaining acceptance as a security tool to augment conventional metal detectors and baggage x-ray systems for passenger screening at airports and other secured facilities. This acceptance indicates that the technology has matured; however, many potential improvements can yet be realized. The authors have developed a number of techniques over the last several years including novel image reconstruction and display techniques, polarimetric imaging techniques, array switching schemes, and high-frequency high-bandwidth techniques. All of these may improve the performance of new systems; however, some of these techniques will increase the cost and complexity of the mm-wave security portal imaging systems. Reducing this cost may require the development of novel array designs. In particular, RF photonic methods may provide new solutions to the design and development of the sequentially switched linear mm-wave arrays that are the key element in the mm-wave portal imaging systems. Highfrequency, high-bandwidth designs are difficult to achieve with conventional mm-wave electronic devices, and RF photonic devices may be a practical alternative. In this paper, the mm-wave imaging techniques developed at PNNL are reviewed and the potential for implementing RF photonic mm-wave array designs is explored.

  6. Coal and char studies by advanced EMR techniques

    SciTech Connect

    Belford, R.L.; Clarkson, R.B.; Odintsov, B.M.

    1999-03-31

    Advanced magnetic resonance (EMR) methods are used to examine properties of coals, chars, and molecular species related to constituents of coal. During this grant period, further progress was made on proton NMR and low-frequency dynamic nuclear polarization (DNP) to examine the interaction between fluids such as water and the surface of suspended char particles. Effects of char particle size and type on water nuclear spin relaxation, T2, were measured and modeled.

  7. Coal and char studies by advanced EMR techniques

    SciTech Connect

    Belford, R.L.; Clarkson, R.B.; Odintsov, B.M.

    1998-09-30

    Advanced magnetic resonance (EMR) methods are used to examine properties of coals, chars, and molecular species related to constituents of coal. During this grant period, further progress was made on proton NMR and low-frequency dynamic nuclear polarization (DNP) to examine the interaction between fluids such as water and the surface of suspended char particles. Effects of char particle size on water nuclear spin relaxation, T2, were measured.

  8. A Liquid Level Measurement Technique Outside a Sealed Metal Container Based on Ultrasonic Impedance and Echo Energy.

    PubMed

    Zhang, Bin; Wei, Yue-Juan; Liu, Wen-Yi; Zhang, Yan-Jun; Yao, Zong; Zhao, Li-Hui; Xiong, Ji-Jun

    2017-01-19

    The proposed method for measuring the liquid level focuses on the ultrasonic impedance and echo energy inside a metal wall, to which the sensor is attached directly, not on ultrasonic waves that penetrate the gas-liquid medium of a container. Firstly, by analyzing the sound field distribution characteristics of the sensor in a metal wall, this paper proposes the concept of an "energy circle" and discusses how to calculate echo energy under three different states in detail. Meanwhile, an ultrasonic transmitting and receiving circuit is designed to convert the echo energy inside the energy circle into its equivalent electric power. Secondly, in order to find the two critical states of the energy circle in the process of liquid level detection, a program is designed to help with calculating two critical positions automatically. Finally, the proposed method is evaluated through a series of experiments, and the experimental results indicate that the proposed method is effective and accurate in calibration of the liquid level outside a sealed metal container.

  9. A Liquid Level Measurement Technique Outside a Sealed Metal Container Based on Ultrasonic Impedance and Echo Energy

    PubMed Central

    Zhang, Bin; Wei, Yue-Juan; Liu, Wen-Yi; Zhang, Yan-Jun; Yao, Zong; Zhao, Li-Hui; Xiong, Ji-Jun

    2017-01-01

    The proposed method for measuring the liquid level focuses on the ultrasonic impedance and echo energy inside a metal wall, to which the sensor is attached directly, not on ultrasonic waves that penetrate the gas–liquid medium of a container. Firstly, by analyzing the sound field distribution characteristics of the sensor in a metal wall, this paper proposes the concept of an "energy circle" and discusses how to calculate echo energy under three different states in detail. Meanwhile, an ultrasonic transmitting and receiving circuit is designed to convert the echo energy inside the energy circle into its equivalent electric power. Secondly, in order to find the two critical states of the energy circle in the process of liquid level detection, a program is designed to help with calculating two critical positions automatically. Finally, the proposed method is evaluated through a series of experiments, and the experimental results indicate that the proposed method is effective and accurate in calibration of the liquid level outside a sealed metal container. PMID:28106857

  10. Ultrasonic evaluation of high voltage circuit boards

    NASA Technical Reports Server (NTRS)

    Klima, S. J.; Riley, T. J.

    1976-01-01

    Preliminary observations indicate that an ultrasonic scanning technique may be useful as a quick, low cost, nondestructive method for judging the quality of circuit board materials for high voltage applications. Corona inception voltage tests were conducted on fiberglass-epoxy and fiberglass-polyimide high pressure laminates from 20 to 140 C. The same materials were scanned ultrasonically by utilizing the single transducer, through-transmission technique with reflector plate, and recording variations in ultrasonic energy transmitted through the board thickness. A direct relationship was observed between ultrasonic transmission level and corona inception voltage. The ultrasonic technique was subsequently used to aid selection of high quality circuit boards for the Communications Technology Satellite.

  11. Study of ultrasonic thermometry based on ultrasonic time-of-flight measurement

    NASA Astrophysics Data System (ADS)

    Jia, Ruixi; Xiong, Qingyu; Wang, Lijie; Wang, Kai; Shen, Xuehua; Liang, Shan; Shi, Xin

    2016-03-01

    Ultrasonic thermometry is a kind of acoustic pyrometry and it has been evolving as a new temperature measurement technology for various environment. However, the accurate measurement of the ultrasonic time-of-flight is the key for ultrasonic thermometry. In this paper, we study the ultrasonic thermometry technique based on ultrasonic time-of-flight measurement with a pair of ultrasonic transducers for transmitting and receiving signal. The ultrasonic transducers are installed in a single path which ultrasonic travels. In order to validate the performance of ultrasonic thermometry, we make a contrast about the absolute error between the measured temperature value and the practical one. With and without heater source, the experimental results indicate ultrasonic thermometry has high precision of temperature measurement.

  12. Application of Active Learning Techniques to an Advanced Course

    NASA Astrophysics Data System (ADS)

    Knop, R. A.

    2004-05-01

    The New Faculty Workshop provided a wealth of techniques as well as an overriding philosophy for the teaching of undergraduate Physics and Astronomy courses. The focus of the workshop was active learning, summarized in ``Learner-Centered Astronomy Teaching" by Slater & Adams: it's not what you do in class that matters, it's what the students do. Much of the specific focus of the New Faculty Workshop is on teaching the large, introductory Physics classes that many of the faculty present are sure to teach, both algebra-based and calculus-based. Many of these techniques apply directly and with little modification to introductory Astronomy courses. However, little direct attention is given to upper-division undergraduate, or even graduate, courses. In this presentation, I will share my experience in attempting to apply some of the techniques discussed at the New Faculty Workshop to an upper-division course in Galactic Astrophysics at Vanderbilt University during the Spring semester of 2004.

  13. The bumper technique for advancing a large profile microcatheter.

    PubMed

    Kellner, Christopher P; Chartrain, Alexander G; Schwegel, Claire; Oxley, Thomas J; Shoirah, Hazem; Mocco, J

    2017-03-09

    Operators commonly encounter difficulty maneuvering a microcatheter beyond the distal lip of wide neck aneurysms and aneurysms in challenging locations. Few techniques have been described to guide operators in these particular situations. In this case report of a 56-year-old woman with a 16 mm ophthalmic artery aneurysm, the microcatheter continually snagged the distal aneurysm lip, preventing delivery of a flow diverter into the distal parent vessel. In troubleshooting this obstacle, a second microguidewire was introduced alongside the microcatheter and was used to cover the distal lip of the aneurysm to prevent further snagging. The second guidewire successfully deflected the microcatheter into the distal vessel, a technique that we have aptly dubbed the 'bumper technique'.

  14. Nondestructive Evaluation of Thick Concrete Using Advanced Signal Processing Techniques

    SciTech Connect

    Clayton, Dwight A; Barker, Alan M; Santos-Villalobos, Hector J; Albright, Austin P; Hoegh, Kyle; Khazanovich, Lev

    2015-09-01

    The purpose of the U.S. Department of Energy Office of Nuclear Energy’s Light Water Reactor Sustainability (LWRS) Program is to develop technologies and other solutions that can improve the reliability, sustain the safety, and extend the operating lifetimes of nuclear power plants (NPPs) beyond 60 years [1]. Since many important safety structures in an NPP are constructed of concrete, inspection techniques must be developed and tested to evaluate the internal condition. In-service containment structures generally do not allow for the destructive measures necessary to validate the accuracy of these inspection techniques. This creates a need for comparative testing of the various nondestructive evaluation (NDE) measurement techniques on concrete specimens with known material properties, voids, internal microstructure flaws, and reinforcement locations.

  15. Preparation of redispersible liposomal dry powder using an ultrasonic spray freeze-drying technique for transdermal delivery of human epithelial growth factor.

    PubMed

    Yin, Fei; Guo, Shiyan; Gan, Yong; Zhang, Xinxin

    2014-01-01

    In this work, an ultrasonic spray freeze-drying (USFD) technique was used to prepare a stable liposomal dry powder for transdermal delivery of recombinant human epithelial growth factor (rhEGF). Morphology, particle size, entrapment efficiency, in vitro release, and skin permeability were systematically compared between rhEGF liposomal dry powder prepared using USFD and that prepared using a conventional lyophilization process. Porous and spherical particles with high specific area were produced under USFD conditions. USFD effectively avoided formation of ice crystals, disruption of the bilayer structure, and drug leakage during the liposome drying process, and maintained the stability of the rhEGF liposomal formulation during storage. The reconstituted rhEGF liposomes prepared from USFD powder did not show significant changes in morphology, particle size, entrapment efficiency, or in vitro release characteristics compared with those of rhEGF liposomes before drying. Moreover, the rhEGF liposomal powder prepared with USFD exhibited excellent enhanced penetration in ex vivo mouse skin compared with that for powder prepared via conventional lyophilization. The results suggest that ultrasonic USFD is a promising technique for the production of stable protein-loaded liposomal dry powder for application to the skin.

  16. Preparation of redispersible liposomal dry powder using an ultrasonic spray freeze-drying technique for transdermal delivery of human epithelial growth factor

    PubMed Central

    Yin, Fei; Guo, Shiyan; Gan, Yong; Zhang, Xinxin

    2014-01-01

    In this work, an ultrasonic spray freeze-drying (USFD) technique was used to prepare a stable liposomal dry powder for transdermal delivery of recombinant human epithelial growth factor (rhEGF). Morphology, particle size, entrapment efficiency, in vitro release, and skin permeability were systematically compared between rhEGF liposomal dry powder prepared using USFD and that prepared using a conventional lyophilization process. Porous and spherical particles with high specific area were produced under USFD conditions. USFD effectively avoided formation of ice crystals, disruption of the bilayer structure, and drug leakage during the liposome drying process, and maintained the stability of the rhEGF liposomal formulation during storage. The reconstituted rhEGF liposomes prepared from USFD powder did not show significant changes in morphology, particle size, entrapment efficiency, or in vitro release characteristics compared with those of rhEGF liposomes before drying. Moreover, the rhEGF liposomal powder prepared with USFD exhibited excellent enhanced penetration in ex vivo mouse skin compared with that for powder prepared via conventional lyophilization. The results suggest that ultrasonic USFD is a promising technique for the production of stable protein-loaded liposomal dry powder for application to the skin. PMID:24729702

  17. Magnetic sensing via ultrasonic excitation

    NASA Astrophysics Data System (ADS)

    Yamada, Hisato; Takashima, Kazuya; Ikushima, Kenji; Toida, Hiraku; Sato, Michitaka; Ishizawa, Yoshiichi

    2013-04-01

    We present ultrasonic techniques for magnetic measurements. Acoustically modulated magnetization is investigated with sensitive rf detection by narrowband loop antennas. Magnetization on the surface of ferromagnetic metals is temporally modulated with the rf frequency of the irradiated ultrasonic waves, and the near-field components emitted from the focal point of the ultrasonic beam are detected. Based on the principle of the acoustically stimulated electromagnetic (ASEM) response, magnetic sensing and tomography are demonstrated by ultrasonic scanning. We show that ASEM imaging combines good acoustic resolution with magnetic contrast. The sensitivity of this method is estimated to be about 6 G/Hz1/2 in our current setup.

  18. Transcranial Doppler: Techniques and advanced applications: Part 2

    PubMed Central

    Sharma, Arvind K.; Bathala, Lokesh; Batra, Amit; Mehndiratta, Man Mohan; Sharma, Vijay K.

    2016-01-01

    Transcranial Doppler (TCD) is the only diagnostic tool that can provide continuous information about cerebral hemodynamics in real time and over extended periods. In the previous paper (Part 1), we have already presented the basic ultrasound physics pertaining to TCD, insonation methods, and various flow patterns. This article describes various advanced applications of TCD such as detection of right-to-left shunt, emboli monitoring, vasomotor reactivity (VMR), monitoring of vasospasm in subarachnoid hemorrhage (SAH), monitoring of intracranial pressure, its role in stoke prevention in sickle cell disease, and as a supplementary test for confirmation of brain death. PMID:27011639

  19. Brain development in preterm infants assessed using advanced MRI techniques.

    PubMed

    Tusor, Nora; Arichi, Tomoki; Counsell, Serena J; Edwards, A David

    2014-03-01

    Infants who are born preterm have a high incidence of neurocognitive and neurobehavioral abnormalities, which may be associated with impaired brain development. Advanced magnetic resonance imaging (MRI) approaches, such as diffusion MRI (d-MRI) and functional MRI (fMRI), provide objective and reproducible measures of brain development. Indices derived from d-MRI can be used to provide quantitative measures of preterm brain injury. Although fMRI of the neonatal brain is currently a research tool, future studies combining d-MRI and fMRI have the potential to assess the structural and functional properties of the developing brain and its response to injury.

  20. Application of advanced coating techniques to rocket engine components

    NASA Technical Reports Server (NTRS)

    Verma, S. K.

    1988-01-01

    The materials problem in the space shuttle main engine (SSME) is reviewed. Potential coatings and the method of their application for improved life of SSME components are discussed. A number of advanced coatings for turbine blade components and disks are being developed and tested in a multispecimen thermal fatigue fluidized bed facility at IIT Research Institute. This facility is capable of producing severe strains of the degree present in blades and disk components of the SSME. The potential coating systems and current efforts at IITRI being taken for life extension of the SSME components are summarized.

  1. Ultrasonic Characterization of Aerospace Composites

    NASA Technical Reports Server (NTRS)

    Leckey, Cara; Johnston, Patrick; Haldren, Harold; Perey, Daniel

    2015-01-01

    Composite materials have seen an increased use in aerospace in recent years and it is expected that this trend will continue due to the benefits of reduced weight, increased strength, and other factors. Ongoing work at NASA involves the investigation of the large-scale use of composites for spacecraft structures (SLS components, Orion Composite Crew Module, etc). NASA is also involved in work to enable the use of composites in advanced aircraft structures through the Advanced Composites Project (ACP). In both areas (space and aeronautics) there is a need for new nondestructive evaluation and materials characterization techniques that are appropriate for characterizing composite materials. This paper will present an overview of NASA's needs for characterizing aerospace composites, including a description of planned and ongoing work under ACP for the detection of composite defects such as fiber waviness, reduced bond strength, delamination damage, and microcracking. The research approaches include investigation of angle array, guided wave, and phase sensitive ultrasonic methods. The use of ultrasonic simulation tools for optimizing and developing methods will also be discussed.

  2. Benefits of advanced software techniques for mission planning systems

    NASA Technical Reports Server (NTRS)

    Gasquet, A.; Parrod, Y.; Desaintvincent, A.

    1994-01-01

    The increasing complexity of modern spacecraft, and the stringent requirement for maximizing their mission return, call for a new generation of Mission Planning Systems (MPS). In this paper, we discuss the requirements for the Space Mission Planning and the benefits which can be expected from Artificial Intelligence techniques through examples of applications developed by Matra Marconi Space.

  3. Advances in reduction techniques for tire contact problems

    NASA Technical Reports Server (NTRS)

    Noor, Ahmed K.

    1995-01-01

    Some recent developments in reduction techniques, as applied to predicting the tire contact response and evaluating the sensitivity coefficients of the different response quantities, are reviewed. The sensitivity coefficients measure the sensitivity of the contact response to variations in the geometric and material parameters of the tire. The tire is modeled using a two-dimensional laminated anisotropic shell theory with the effects of variation in geometric and material parameters, transverse shear deformation, and geometric nonlinearities included. The contact conditions are incorporated into the formulation by using a perturbed Lagrangian approach with the fundamental unknowns consisting of the stress resultants, the generalized displacements, and the Lagrange multipliers associated with the contact conditions. The elemental arrays are obtained by using a modified two-field, mixed variational principle. For the application of reduction techniques, the tire finite element model is partitioned into two regions. The first region consists of the nodes that are likely to come in contact with the pavement, and the second region includes all the remaining nodes. The reduction technique is used to significantly reduce the degrees of freedom in the second region. The effectiveness of the computational procedure is demonstrated by a numerical example of the frictionless contact response of the space shuttle nose-gear tire, inflated and pressed against a rigid flat surface. Also, the research topics which have high potential for enhancing the effectiveness of reduction techniques are outlined.

  4. In Situ Techniques for Monitoring Electrochromism: An Advanced Laboratory Experiment

    ERIC Educational Resources Information Center

    Saricayir, Hakan; Uce, Musa; Koca, Atif

    2010-01-01

    This experiment employs current technology to enhance and extend existing lab content. The basic principles of spectroscopic and electroanalytical techniques and their use in determining material properties are covered in some detail in many undergraduate chemistry programs. However, there are limited examples of laboratory experiments with in…

  5. Advances in High-Fidelity Multi-Physics Simulation Techniques

    DTIC Science & Technology

    2008-01-01

    fluid dynamics with other disciplines also yield a large and typically stiff equation set whose numerical solution mandates the development and...and Electromagnetics . . . . . 3 2.1 Governing Equations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.2 Numerical Technique...discrete equivalent of the governing equations . Thus, the values of the solution vector are localized in a pointwise sense at each node of the mesh. This

  6. Single Molecule Techniques for Advanced in situ Hybridization

    SciTech Connect

    Hollars, C W; Stubbs, L; Carlson, K; Lu, X; Wehri, E

    2003-02-03

    One of the most significant achievements of modern science is completion of the human genome sequence, completed in the year 2000. Despite this monumental accomplishment, researchers have only begun to understand the relationships between this three-billion-nucleotide genetic code and the regulation and control of gene and protein expression within each of the millions of different types of highly specialized cells. Several methodologies have been developed for the analysis of gene and protein expression in situ, yet despite these advancements, the pace of such analyses is extremely limited. Because information regarding the precise timing and location of gene expression is a crucial component in the discovery of new pharmacological agents for the treatment of disease, there is an enormous incentive to develop technologies that accelerate the analytical process. Here we report on the use of plasmon resonant particles as advanced probes for in situ hybridization. These probes are used for the detection of low levels of gene-probe response and demonstrate a detection method that enables precise, simultaneous localization within a cell of the points of expression of multiple genes or proteins in a single sample.

  7. Ultrasonic Bonding to Metalized Plastic

    NASA Technical Reports Server (NTRS)

    Conroy, B. L.; Cruzan, C. T.

    1986-01-01

    New technique makes it possible to bond wires ultrasonically to conductor patterns on such soft substrates as plain or ceramic-filled polytetrafluoroethylene. With ultrasonic bonding, unpackaged chips attached to soft circuit boards. Preferred because chips require substrate area and better matched electrically to circuit board at high frequencies.

  8. Advanced optical techniques for monitoring dosimetric parameters in photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Li, Buhong; Qiu, Zhihai; Huang, Zheng

    2012-12-01

    Photodynamic therapy (PDT) is based on the generation of highly reactive singlet oxygen through interactions of photosensitizer, light and molecular oxygen. PDT has become a clinically approved, minimally invasive therapeutic modality for a wide variety of malignant and nonmalignant diseases. The main dosimetric parameters for predicting the PDT efficacy include the delivered light dose, the quantification and photobleaching of the administrated photosensitizer, the tissue oxygen concentration, the amount of singlet oxygen generation and the resulting biological responses. This review article presents the emerging optical techniques that in use or under development for monitoring dosimetric parameters during PDT treatment. Moreover, the main challenges in developing real-time and noninvasive optical techniques for monitoring dosimetric parameters in PDT will be described.

  9. Characterization of PTFE Using Advanced Thermal Analysis Techniques

    NASA Astrophysics Data System (ADS)

    Blumm, J.; Lindemann, A.; Meyer, M.; Strasser, C.

    2010-10-01

    Polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer used in numerous industrial applications. It is often referred to by its trademark name, Teflon. Thermal characterization of a PTFE material was carried out using various thermal analysis and thermophysical properties test techniques. The transformation energetics and specific heat were measured employing differential scanning calorimetry. The thermal expansion and the density changes were determined employing pushrod dilatometry. The viscoelastic properties (storage and loss modulus) were analyzed using dynamic mechanical analysis. The thermal diffusivity was measured using the laser flash technique. Combining thermal diffusivity data with specific heat and density allows calculation of the thermal conductivity of the polymer. Measurements were carried out from - 125 °C up to 150 °C. Additionally, measurements of the mechanical properties were carried out down to - 170 °C. The specific heat tests were conducted into the fully molten regions up to 370 °C.

  10. Advance techniques for monitoring human tolerance to +Gz accelerations.

    NASA Technical Reports Server (NTRS)

    Pelligra, R.; Sandler, H.; Rositano, S.; Skrettingland, K.; Mancini, R.

    1972-01-01

    Standard techniques for monitoring the acceleration-stressed human subject have been augmented by measuring (1) temporal, brachial and/or radial arterial blood flow, and (2) indirect systolic and diastolic blood pressure at 60-sec intervals. Results show that the response of blood pressure to positive accelerations is complex and dependent on an interplay of hydrostatic forces, diminishing venous return, redistribution of blood, and other poorly defined compensatory reflexes.

  11. Advanced techniques for characterization of ion beam modified materials

    DOE PAGES

    Zhang, Yanwen; Debelle, Aurélien; Boulle, Alexandre; ...

    2014-10-30

    Understanding the mechanisms of damage formation in materials irradiated with energetic ions is essential for the field of ion-beam materials modification and engineering. Utilizing incident ions, electrons, photons, and positrons, various analysis techniques, including Rutherford backscattering spectrometry (RBS), electron RBS, Raman spectroscopy, high-resolution X-ray diffraction, small-angle X-ray scattering, and positron annihilation spectroscopy, are routinely used or gaining increasing attention in characterizing ion beam modified materials. The distinctive information, recent developments, and some perspectives in these techniques are reviewed in this paper. Applications of these techniques are discussed to demonstrate their unique ability for studying ion-solid interactions and the corresponding radiationmore » effects in modified depths ranging from a few nm to a few tens of μm, and to provide information on electronic and atomic structure of the materials, defect configuration and concentration, as well as phase stability, amorphization and recrystallization processes. Finally, such knowledge contributes to our fundamental understanding over a wide range of extreme conditions essential for enhancing material performance and also for design and synthesis of new materials to address a broad variety of future energy applications.« less

  12. Advanced techniques for characterization of ion beam modified materials

    SciTech Connect

    Zhang, Yanwen; Debelle, Aurélien; Boulle, Alexandre; Kluth, Patrick; Tuomisto, Filip

    2014-10-30

    Understanding the mechanisms of damage formation in materials irradiated with energetic ions is essential for the field of ion-beam materials modification and engineering. Utilizing incident ions, electrons, photons, and positrons, various analysis techniques, including Rutherford backscattering spectrometry (RBS), electron RBS, Raman spectroscopy, high-resolution X-ray diffraction, small-angle X-ray scattering, and positron annihilation spectroscopy, are routinely used or gaining increasing attention in characterizing ion beam modified materials. The distinctive information, recent developments, and some perspectives in these techniques are reviewed in this paper. Applications of these techniques are discussed to demonstrate their unique ability for studying ion-solid interactions and the corresponding radiation effects in modified depths ranging from a few nm to a few tens of μm, and to provide information on electronic and atomic structure of the materials, defect configuration and concentration, as well as phase stability, amorphization and recrystallization processes. Finally, such knowledge contributes to our fundamental understanding over a wide range of extreme conditions essential for enhancing material performance and also for design and synthesis of new materials to address a broad variety of future energy applications.

  13. Development of processing techniques for advanced thermal protection materials

    NASA Technical Reports Server (NTRS)

    Selvaduray, Guna S.

    1994-01-01

    The effort, which was focused on the research and development of advanced materials for use in Thermal Protection Systems (TPS), has involved chemical and physical testing of refractory ceramic tiles, fabrics, threads and fibers. This testing has included determination of the optical properties, thermal shock resistance, high temperature dimensional stability, and tolerance to environmental stresses. Materials have also been tested in the Arc Jet 2 x 9 Turbulent Duct Facility (TDF), the 1 atmosphere Radiant Heat Cycler, and the Mini-Wind Tunnel Facility (MWTF). A significant part of the effort hitherto has gone towards modifying and upgrading the test facilities so that meaningful tests can be carried out. Another important effort during this period has been the creation of a materials database. Computer systems administration and support have also been provided. These are described in greater detail below.

  14. Recent advances in bioprinting techniques: approaches, applications and future prospects.

    PubMed

    Li, Jipeng; Chen, Mingjiao; Fan, Xianqun; Zhou, Huifang

    2016-09-20

    Bioprinting technology shows potential in tissue engineering for the fabrication of scaffolds, cells, tissues and organs reproducibly and with high accuracy. Bioprinting technologies are mainly divided into three categories, inkjet-based bioprinting, pressure-assisted bioprinting and laser-assisted bioprinting, based on their underlying printing principles. These various printing technologies have their advantages and limitations. Bioprinting utilizes biomaterials, cells or cell factors as a "bioink" to fabricate prospective tissue structures. Biomaterial parameters such as biocompatibility, cell viability and the cellular microenvironment strongly influence the printed product. Various printing technologies have been investigated, and great progress has been made in printing various types of tissue, including vasculature, heart, bone, cartilage, skin and liver. This review introduces basic principles and key aspects of some frequently used printing technologies. We focus on recent advances in three-dimensional printing applications, current challenges and future directions.

  15. Advanced materials and techniques for fibre-optic sensing

    NASA Astrophysics Data System (ADS)

    Henderson, Philip J.

    2014-06-01

    Fibre-optic monitoring systems came of age in about 1999 upon the emergence of the world's first significant commercialising company - a spin-out from the UK's collaborative MAST project. By using embedded fibre-optic technology, the MAST project successfully measured transient strain within high-performance composite yacht masts. Since then, applications have extended from smart composites into civil engineering, energy, military, aerospace, medicine and other sectors. Fibre-optic sensors come in various forms, and may be subject to embedment, retrofitting, and remote interrogation. The unique challenges presented by each implementation require careful scrutiny before widespread adoption can take place. Accordingly, various aspects of design and reliability are discussed spanning a range of representative technologies that include resonant microsilicon structures, MEMS, Bragg gratings, advanced forms of spectroscopy, and modern trends in nanotechnology. Keywords: Fibre-optic sensors, fibre Bragg gratings, MEMS, MOEMS, nanotechnology, plasmon.

  16. Advanced Techniques for Constrained Internal Coordinate Molecular Dynamics

    PubMed Central

    Wagner, Jeffrey R.; Balaraman, Gouthaman S.; Niesen, Michiel J. M.; Larsen, Adrien B.; Jain, Abhinandan; Vaidehi, Nagarajan

    2013-01-01

    Internal coordinate molecular dynamics (ICMD) methods provide a more natural description of a protein by using bond, angle and torsional coordinates instead of a Cartesian coordinate representation. Freezing high frequency bonds and angles in the ICMD model gives rise to constrained ICMD (CICMD) models. There are several theoretical aspects that need to be developed in order to make the CICMD method robust and widely usable. In this paper we have designed a new framework for 1) initializing velocities for non-independent CICMD coordinates, 2) efficient computation of center of mass velocity during CICMD simulations, 3) using advanced integrators such as Runge-Kutta, Lobatto and adaptive CVODE for CICMD simulations, and 4) cancelling out the “flying ice cube effect” that sometimes arises in Nosé-Hoover dynamics. The Generalized Newton-Euler Inverse Mass Operator (GNEIMO) method is an implementation of a CICMD method that we have developed to study protein dynamics. GNEIMO allows for a hierarchy of coarse-grained simulation models based on the ability to rigidly constrain any group of atoms. In this paper, we perform tests on the Lobatto and Runge-Kutta integrators to determine optimal simulation parameters. We also implement an adaptive coarse graining tool using the GNEIMO Python interface. This tool enables the secondary structure-guided “freezing and thawing” of degrees of freedom in the molecule on the fly during MD simulations, and is shown to fold four proteins to their native topologies. With these advancements we envision the use of the GNEIMO method in protein structure prediction, structure refinement, and in studying domain motion. PMID:23345138

  17. Advanced techniques for constrained internal coordinate molecular dynamics.

    PubMed

    Wagner, Jeffrey R; Balaraman, Gouthaman S; Niesen, Michiel J M; Larsen, Adrien B; Jain, Abhinandan; Vaidehi, Nagarajan

    2013-04-30

    Internal coordinate molecular dynamics (ICMD) methods provide a more natural description of a protein by using bond, angle, and torsional coordinates instead of a Cartesian coordinate representation. Freezing high-frequency bonds and angles in the ICMD model gives rise to constrained ICMD (CICMD) models. There are several theoretical aspects that need to be developed to make the CICMD method robust and widely usable. In this article, we have designed a new framework for (1) initializing velocities for nonindependent CICMD coordinates, (2) efficient computation of center of mass velocity during CICMD simulations, (3) using advanced integrators such as Runge-Kutta, Lobatto, and adaptive CVODE for CICMD simulations, and (4) cancelling out the "flying ice cube effect" that sometimes arises in Nosé-Hoover dynamics. The Generalized Newton-Euler Inverse Mass Operator (GNEIMO) method is an implementation of a CICMD method that we have developed to study protein dynamics. GNEIMO allows for a hierarchy of coarse-grained simulation models based on the ability to rigidly constrain any group of atoms. In this article, we perform tests on the Lobatto and Runge-Kutta integrators to determine optimal simulation parameters. We also implement an adaptive coarse-graining tool using the GNEIMO Python interface. This tool enables the secondary structure-guided "freezing and thawing" of degrees of freedom in the molecule on the fly during molecular dynamics simulations and is shown to fold four proteins to their native topologies. With these advancements, we envision the use of the GNEIMO method in protein structure prediction, structure refinement, and in studying domain motion.

  18. Application of a Full Hybrid Ultrasonic System to Improve the Steelmaking Practices

    NASA Astrophysics Data System (ADS)

    Kurzepa, Dimitri; Gremeaux, Gilles; Krebs, Benoit

    This paper exposes the performances of a full hybrid ultrasonic system in terms of accuracy, sensibility, pooled volume, size of defect and time of analysis. The contributions of the high-frequency control with regard to the low frequency ultrasonic control and the conventional characterization techniques of steels are also explained. The fine analyses obtained allow advanced study of either the manufacturing processes and their optimization. This technique adapted to the challenging markets allows handling the most demanding customers of high quality steel grade. Perspectives in terms of product improvement and experimental techniques development are also discussed.

  19. Advances in parameter estimation techniques applied to flexible structures

    NASA Technical Reports Server (NTRS)

    Maben, Egbert; Zimmerman, David C.

    1994-01-01

    In this work, various parameter estimation techniques are investigated in the context of structural system identification utilizing distributed parameter models and 'measured' time-domain data. Distributed parameter models are formulated using the PDEMOD software developed by Taylor. Enhancements made to PDEMOD for this work include the following: (1) a Wittrick-Williams based root solving algorithm; (2) a time simulation capability; and (3) various parameter estimation algorithms. The parameter estimations schemes will be contrasted using the NASA Mini-Mast as the focus structure.

  20. Advances in dental veneers: materials, applications, and techniques

    PubMed Central

    Pini, Núbia Pavesi; Aguiar, Flávio Henrique Baggio; Lima, Débora Alves Nunes Leite; Lovadino, José Roberto; Terada, Raquel Sano Suga; Pascotto, Renata Corrêa

    2012-01-01

    Laminate veneers are a conservative treatment of unaesthetic anterior teeth. The continued development of dental ceramics offers clinicians many options for creating highly aesthetic and functional porcelain veneers. This evolution of materials, ceramics, and adhesive systems permits improvement of the aesthetic of the smile and the self-esteem of the patient. Clinicians should understand the latest ceramic materials in order to be able to recommend them and their applications and techniques, and to ensure the success of the clinical case. The current literature was reviewed to search for the most important parameters determining the long-term success, correct application, and clinical limitations of porcelain veneers. PMID:23674920

  1. Advanced terahertz techniques for quality control and counterfeit detection

    NASA Astrophysics Data System (ADS)

    Ahi, Kiarash; Anwar, Mehdi

    2016-04-01

    This paper reports our invented methods for detection of counterfeit electronic. These versatile techniques are also handy in quality control applications. Terahertz pulsed laser systems are capable of giving the material characteristics and thus make it possible to distinguish between the materials used in authentic components and their counterfeit clones. Components with material defects can also be distinguished in section in this manner. In this work different refractive indices and absorption coefficients were observed for counterfeit components compared to their authentic counterparts. Existence of unexpected ingredient materials was detected in counterfeit components by Fourier Transform analysis of the transmitted terahertz pulse. Thicknesses of different layers are obtainable by analyzing the reflected terahertz pulse. Existence of unexpected layers is also detectable in this manner. Recycled, sanded and blacktopped counterfeit electronic components were detected as a result of these analyses. Counterfeit ICs with die dislocations were detected by depicting the terahertz raster scanning data in a coordinate plane which gives terahertz images. In the same manner, raster scanning of the reflected pulse gives terahertz images of the surfaces of the components which were used to investigate contaminant materials and sanded points on the surfaces. The results of the later technique, reveals the recycled counterfeit components.

  2. Advanced techniques in reliability model representation and solution

    NASA Technical Reports Server (NTRS)

    Palumbo, Daniel L.; Nicol, David M.

    1992-01-01

    The current tendency of flight control system designs is towards increased integration of applications and increased distribution of computational elements. The reliability analysis of such systems is difficult because subsystem interactions are increasingly interdependent. Researchers at NASA Langley Research Center have been working for several years to extend the capability of Markov modeling techniques to address these problems. This effort has been focused in the areas of increased model abstraction and increased computational capability. The reliability model generator (RMG) is a software tool that uses as input a graphical object-oriented block diagram of the system. RMG uses a failure-effects algorithm to produce the reliability model from the graphical description. The ASSURE software tool is a parallel processing program that uses the semi-Markov unreliability range evaluator (SURE) solution technique and the abstract semi-Markov specification interface to the SURE tool (ASSIST) modeling language. A failure modes-effects simulation is used by ASSURE. These tools were used to analyze a significant portion of a complex flight control system. The successful combination of the power of graphical representation, automated model generation, and parallel computation leads to the conclusion that distributed fault-tolerant system architectures can now be analyzed.

  3. Comparison of three advanced chromatographic techniques for cannabis identification.

    PubMed

    Debruyne, D; Albessard, F; Bigot, M C; Moulin, M

    1994-01-01

    The development of chromatography technology, with the increasing availability of easier-to-use mass spectrometers combined with gas chromatography (GC), the use of diode-array or programmable variable-wavelength ultraviolet absorption detectors in conjunction with high-performance liquid chromatography (HPLC), and the availability of scanners capable of reading thin-layer chromatography (TLC) plates in the ultraviolet and visible regions, has made for easier, quicker and more positive identification of cannabis samples that standard analytical laboratories are occasionally required to undertake in the effort to combat drug addiction. At laboratories that do not possess the technique of GC combined with mass spectrometry, which provides an irrefutable identification, the following procedure involving HPLC or TLC techniques may be used: identification of the chromatographic peaks corresponding to each of the three main cannabis constituents-cannabidiol (CBD), delta-9-tetrahydrocannabinol (delta-9-THC) and cannabinol (CBN)-by comparison with published data in conjunction with a specific absorption spectrum for each of those constituents obtained between 200 and 300 nm. The collection of the fractions corresponding to the three major cannabinoids at the HPLC system outlet and the cross-checking of their identity in the GC process with flame ionization detection can further corroborate the identification and minimize possible errors due to interference.

  4. XII Advanced Computing and Analysis Techniques in Physics Research

    NASA Astrophysics Data System (ADS)

    Speer, Thomas; Carminati, Federico; Werlen, Monique

    November 2008 will be a few months after the official start of LHC when the highest quantum energy ever produced by mankind will be observed by the most complex piece of scientific equipment ever built. LHC will open a new era in physics research and push further the frontier of Knowledge This achievement has been made possible by new technological developments in many fields, but computing is certainly the technology that has made possible this whole enterprise. Accelerator and detector design, construction management, data acquisition, detectors monitoring, data analysis, event simulation and theoretical interpretation are all computing based HEP activities but also occurring many other research fields. Computing is everywhere and forms the common link between all involved scientists and engineers. The ACAT workshop series, created back in 1990 as AIHENP (Artificial Intelligence in High Energy and Nuclear Research) has been covering the tremendous evolution of computing in its most advanced topics, trying to setup bridges between computer science, experimental and theoretical physics. Conference web-site: http://acat2008.cern.ch/ Programme and presentations: http://indico.cern.ch/conferenceDisplay.py?confId=34666

  5. Coal and Coal Constituent Studies by Advanced EMR Techniques

    SciTech Connect

    Alex I. Smirnov; Mark J. Nilges; R. Linn Belford; Robert B. Clarkson

    1998-03-31

    Advanced electronic magnetic resonance (EMR) methods are used to examine properties of coals, chars, and molecular species related to constituents of coal. We have achieved substantial progress on upgrading the high field (HF) EMR (W-band, 95 GHz) spectrometers that are especially advantageous for such studies. Particularly, we have built a new second W-band instrument (Mark II) in addition to our Mark I. Briefly, Mark II features: (i) an Oxford custom-built 7 T superconducting magnet which is scannable from 0 to 7 T at up to 0.5 T/min; (ii) water-cooled coaxial solenoid with up to ±550 G scan under digital (15 bits resolution) computer control; (iii) custom-engineered precision feed-back circuit, which is used to drive this solenoid, is based on an Ultrastab 860R sensor that has linearity better than 5 ppm and resolution of 0.05 ppm; (iv) an Oxford CF 1200 cryostat for variable temperature studies from 1.8 to 340 K. During this grant period we have completed several key upgrades of both Mark I and II, particularly microwave bridge, W-band probehead, and computer interfaces. We utilize these improved instruments for HF EMR studies of spin-spin interaction and existence of different paramagnetic species in carbonaceous solids.

  6. Analytical Ultrasonics in Materials Research and Testing

    NASA Technical Reports Server (NTRS)

    Vary, A.

    1986-01-01

    Research results in analytical ultrasonics for characterizing structural materials from metals and ceramics to composites are presented. General topics covered by the conference included: status and advances in analytical ultrasonics for characterizing material microstructures and mechanical properties; status and prospects for ultrasonic measurements of microdamage, degradation, and underlying morphological factors; status and problems in precision measurements of frequency-dependent velocity and attenuation for materials analysis; procedures and requirements for automated, digital signal acquisition, processing, analysis, and interpretation; incentives for analytical ultrasonics in materials research and materials processing, testing, and inspection; and examples of progress in ultrasonics for interrelating microstructure, mechanical properites, and dynamic response.

  7. Materials analysis by ultrasonics: Metals, ceramics, composites

    NASA Technical Reports Server (NTRS)

    Vary, Alex (Editor)

    1987-01-01

    Research results in analytical ultrasonics for characterizing structural materials from metals and ceramics to composites are presented. General topics covered by the conference included: status and advances in analytical ultrasonics for characterizing material microstructures and mechanical properties; status and prospects for ultrasonic measurements of microdamage, degradation, and underlying morphological factors; status and problems in precision measurements of frequency-dependent velocity and attenuation for materials analysis; procedures and requirements for automated, digital signal acquisition, processing, analysis, and interpretation; incentives for analytical ultrasonics in materials research and materials processing, testing, and inspection; and examples of progress in ultrasonics for interrelating microstructure, mechanical properties, and dynamic response.

  8. In vivo validation of a bimodal technique combining time-resolved fluorescence spectroscopy and ultrasonic backscatter microscopy for diagnosis of oral carcinoma

    NASA Astrophysics Data System (ADS)

    Sun, Yang; Xie, Hongtao; Liu, Jing; Lam, Matthew; Chaudhari, Abhijit J.; Zhou, Feifei; Bec, Julien; Yankelevich, Diego R.; Dobbie, Allison; Tinling, Steven L.; Gandour-Edwards, Regina F.; Monsky, Wayne L.; Gregory Farwell, D.; Marcu, Laura

    2012-11-01

    Tissue diagnostic features generated by a bimodal technique integrating scanning time-resolved fluorescence spectroscopy (TRFS) and ultrasonic backscatter microscopy (UBM) are investigated in an in vivo hamster oral carcinoma model. Tissue fluorescence is excited by a pulsed nitrogen laser and spectrally and temporally resolved using a set of filters/dichroic mirrors and a fast digitizer, respectively. A 41-MHz focused transducer (37-μm axial, 65-μm lateral resolution) is used for UBM scanning. Representative lesions of the different stages of carcinogenesis show that fluorescence characteristics complement ultrasonic features, and both correlate with histological findings. These results demonstrate that TRFS-UBM provide a wealth of co-registered, complementary data concerning tissue composition and structure as it relates to disease status. The direct co-registration of the TRFS data (sensitive to surface molecular changes) with the UBM data (sensitive to cross-sectional structural changes and depth of tumor invasion) is expected to play an important role in pre-operative diagnosis and intra-operative determination of tumor margins.

  9. Bioactive glass thin films synthesized by advanced pulsed laser techniques

    NASA Astrophysics Data System (ADS)

    Mihailescu, N.; Stan, George E.; Ristoscu, C.; Sopronyi, M.; Mihailescu, Ion N.

    2016-10-01

    Bioactive materials play an increasingly important role in the biomaterials industry, and are extensively used in a range of applications, including biodegradable metallic implants. We report on Bioactive Glasses (BG) films deposition by pulsed laser techniques onto biodegradable substrates. The BG coatings were obtained using a KrF* excimer laser source (λ= 248 nm, τFWHM ≤ 25 ns).Their thickness has been determined by Profilometry measurements, whilst their morphology has been analysed by Scanning Electron Microscopy (SEM). The obtained coatings fairly preserved the targets composition and structure, as revealed by Energy Dispersive X-Ray Spectroscopy, Grazing Incidence X-Ray Diffraction, and Fourier Transform Infra-Red Spectroscopy analyses.

  10. Advanced Techniques in Musculoskeletal Oncology: Perfusion, Diffusion, and Spectroscopy.

    PubMed

    Teixeira, Pedro A Gondim; Beaumont, Marine; Gabriela, Hossu; Bailiang, Chen; Verhaeghe, Jean-luc; Sirveaux, François; Blum, Alain

    2015-12-01

    The imaging characterization of musculoskeletal tumors can be challenging, and a significant number of lesions remain indeterminate when conventional imaging protocols are used. In recent years, clinical availability of functional imaging methods has increased. Functional imaging has the potential to improve tumor detection, characterization, and follow-up. The most frequently used functional methods are perfusion imaging, diffusion-weighted imaging (DWI), and MR proton spectroscopy (MRS). Each of these techniques has specific protocol requirements and diagnostic pitfalls that need to be acknowledged to avoid misdiagnoses. Additionally, the application of functional methods in the MSK system has various technical issues that need to be addressed to ensure data quality and comparability. In this article, the application of contrast-enhanced perfusion imaging, DWI, and MRS for the evaluation of bone and soft tissue tumors is discussed, with emphasis on acquisition protocols, technical difficulties, and current clinical indications.

  11. Advanced fabrication techniques for hydrogen-cooled engine structures

    NASA Technical Reports Server (NTRS)

    Buchmann, O. A.; Arefian, V. V.; Warren, H. A.; Vuigner, A. A.; Pohlman, M. J.

    1985-01-01

    Described is a program for development of coolant passage geometries, material systems, and joining processes that will produce long-life hydrogen-cooled structures for scramjet applications. Tests were performed to establish basic material properties, and samples constructed and evaluated to substantiate fabrication processes and inspection techniques. Results of the study show that the basic goal of increasing the life of hydrogen-cooled structures two orders of magnitude relative to that of the Hypersonic Research Engine can be reached with available means. Estimated life is 19000 cycles for the channels and 16000 cycles for pin-fin coolant passage configurations using Nickel 201. Additional research is required to establish the fatigue characteristics of dissimilar-metal coolant passages (Nickel 201/Inconel 718) and to investigate the embrittling effects of the hydrogen coolant.

  12. Advances in techniques for assessment of microalgal lipids.

    PubMed

    Challagulla, Vineela; Nayar, Sasi; Walsh, Kerry; Fabbro, Larelle

    2016-07-15

    Microalgae are a varied group of organisms with considerable commercial potential as sources of various biochemicals, storage molecules and metabolites such as lipids, sugars, amino acids, pigments and toxins. Algal lipids can be processed to bio-oils and biodiesel. The conventional method to estimate algal lipids is based on extraction using solvents and quantification by gravimetry or chromatography. Such methods are time consuming, use hazardous chemicals and are labor intensive. For rapid screening of prospective algae or for management decisions (e.g. decision on timing of harvest), a rapid, high throughput, reliable, accurate, cost effective and preferably nondestructive analytical technique is desirable. This manuscript reviews the application of fluorescent lipid soluble dyes (Nile Red and BODIPY 505/515), nuclear magnetic resonance (NMR), Raman, Fourier transform infrared (FTIR) and near infrared (NIR) spectroscopy for the assessment of lipids in microalgae.

  13. Wire Crimp Connectors Verification using Ultrasonic Inspection

    NASA Technical Reports Server (NTRS)

    Cramer, K. Elliott; Perey, Daniel F.; Yost, William T.

    2007-01-01

    The development of a new ultrasonic measurement technique to quantitatively assess wire crimp connections is discussed. The amplitude change of a compressional ultrasonic wave propagating through the junction of a crimp connector and wire is shown to correlate with the results of a destructive pull test, which previously has been used to assess crimp wire junction quality. Various crimp junction pathologies (missing wire strands, incorrect wire gauge, incomplete wire insertion in connector) are ultrasonically tested, and their results are correlated with pull tests. Results show that the ultrasonic measurement technique consistently (as evidenced with pull-testing data) predicts good crimps when ultrasonic transmission is above a certain threshold amplitude level. A physics-based model, solved by finite element analysis, describes the compressional ultrasonic wave propagation through the junction during the crimping process. This model is in agreement within 6% of the ultrasonic measurements. A prototype instrument for applying the technique while wire crimps are installed is also presented.

  14. Techniques for laser welding polymeric devices.

    PubMed

    Jones, I A

    2003-04-01

    Recent advances in laser techniques mean that lasers are now being considered as an alternative to vibration, ultrasonic, dielectric, hot plate or hot bar welding, and adhesive bonding of plastics. The techniques required to put laser welding methods into practice are described for medical devices, tubular systems, films and synthetic fabrics.

  15. Advanced Infusion Techniques with 3-D Printed Tooling

    SciTech Connect

    Nuttall, David; Elliott, Amy; Post, Brian K.; Love, Lonnie J.

    2016-05-10

    The manufacturing of tooling for large, contoured surfaces for fiber-layup applications requires significant effort to understand the geometry and then to subtractively manufacture the tool. Traditional methods for the auto industry use clay that is hand sculpted. In the marine pleasure craft industry, the exterior of the model is formed from a foam lay-up that is either hand cut or machined to create smooth lines. Engineers and researchers at Oak Ridge National Laboratory s Manufacturing Demonstration Facility (ORNL MDF) collaborated with Magnum Venus Products (MVP) in the development of a process for reproducing legacy whitewater adventure craft via digital scanning and large scale 3-D printed layup molds. The process entailed 3D scanning a legacy canoe form, converting that form to a CAD model, additively manufacturing (3-D Print) the mold tool, and subtractively finishing the mold s transfer surfaces. Future work will include applying a gelcoat to the mold transfer surface and infusing using vacuum assisted resin transfer molding, or VARTM principles, to create a watertight vessel. The outlined steps were performed on a specific canoe geometry found by MVP s principal participant. The intent of utilizing this geometry is to develop an energy efficient and marketable process for replicating complex shapes, specifically focusing on this particular watercraft, and provide a finished product for demonstration to the composites industry. The culminating part produced through this agreement has been slated for public presentation and potential demonstration at the 2016 CAMX (Composites and Advanced Materials eXpo) exposition in Anaheim, CA. Phase I of this collaborative research and development agreement (MDF-15-68) was conducted under CRADA NFE-15-05575 and was initiated on May 7, 2015, with an introduction to the MVP product line, and concluded in March of 2016 with the printing of and processing of a canoe mold. The project partner Magnum Venous Products (MVP) is

  16. Recent advances in techniques for tsetse-fly control*

    PubMed Central

    MacLennan, K. J. R.

    1967-01-01

    With the advent of modern persistent insecticides, it has become possible to utilize some of the knowledge that has accumulated on the ecology and bionomics of Glossina and to devise more effective techniques for the control and eventual extermination of these species. The present article, based on experience of the tsetse fly problem in Northern Nigeria, points out that the disadvantages of control techniques—heavy expenditure of money and manpower and undue damage to the biosystem—can now largely be overcome by basing the application of insecticides on knowledge of the habits of the particular species of Glossina in a particular environment. Two factors are essential to the success of a control project: the proper selection of sites for spraying (the concept of restricted application) and the degree of persistence of the insecticide used. Reinfestation from within or outside the project area must also be taken into account. These and other aspects are discussed in relation to experience gained from a successful extermination project carried out in the Sudan vegetation zone and from present control activities in the Northern Guinea vegetation zone. PMID:5301739

  17. Advances in Current Rating Techniques for Flexible Printed Circuits

    NASA Technical Reports Server (NTRS)

    Hayes, Ron

    2014-01-01

    Twist Capsule Assemblies are power transfer devices commonly used in spacecraft mechanisms that require electrical signals to be passed across a rotating interface. Flexible printed circuits (flex tapes, see Figure 2) are used to carry the electrical signals in these devices. Determining the current rating for a given trace (conductor) size can be challenging. Because of the thermal conditions present in this environment the most appropriate approach is to assume that the only means by which heat is removed from the trace is thru the conductor itself, so that when the flex tape is long the temperature rise in the trace can be extreme. While this technique represents a worst-case thermal situation that yields conservative current ratings, this conservatism may lead to overly cautious designs when not all traces are used at their full rated capacity. A better understanding of how individual traces behave when they are not all in use is the goal of this research. In the testing done in support of this paper, a representative flex tape used for a flight Solar Array Drive Assembly (SADA) application was tested by energizing individual traces (conductors in the tape) in a vacuum chamber and the temperatures of the tape measured using both fine-gauge thermocouples and infrared thermographic imaging. We find that traditional derating schemes used for bundles of wires do not apply for the configuration tested. We also determine that single active traces located in the center of a flex tape operate at lower temperatures than those on the outside edges.

  18. Advanced Manufacturing Techniques Demonstrated for Fabricating Developmental Hardware

    NASA Technical Reports Server (NTRS)

    Redding, Chip

    2004-01-01

    NASA Glenn Research Center's Engineering Development Division has been working in support of innovative gas turbine engine systems under development by Glenn's Combustion Branch. These one-of-a-kind components require operation under extreme conditions. High-temperature ceramics were chosen for fabrication was because of the hostile operating environment. During the designing process, it became apparent that traditional machining techniques would not be adequate to produce the small, intricate features for the conceptual design, which was to be produced by stacking over a dozen thin layers with many small features that would then be aligned and bonded together into a one-piece unit. Instead of using traditional machining, we produced computer models in Pro/ENGINEER (Parametric Technology Corporation (PTC), Needham, MA) to the specifications of the research engineer. The computer models were exported in stereolithography standard (STL) format and used to produce full-size rapid prototype polymer models. These semi-opaque plastic models were used for visualization and design verification. The computer models also were exported in International Graphics Exchange Specification (IGES) format and sent to Glenn's Thermal/Fluids Design & Analysis Branch and Applied Structural Mechanics Branch for profiling heat transfer and mechanical strength analysis.

  19. Simulation of an advanced techniques of ion propulsion Rocket system

    NASA Astrophysics Data System (ADS)

    Bakkiyaraj, R.

    2016-07-01

    The ion propulsion rocket system is expected to become popular with the development of Deuterium,Argon gas and Hexagonal shape Magneto hydrodynamic(MHD) techniques because of the stimulation indirectly generated the power from ionization chamber,design of thrust range is 1.2 N with 40 KW of electric power and high efficiency.The proposed work is the study of MHD power generation through ionization level of Deuterium gas and combination of two gaseous ions(Deuterium gas ions + Argon gas ions) at acceleration stage.IPR consists of three parts 1.Hexagonal shape MHD based power generator through ionization chamber 2.ion accelerator 3.Exhaust of Nozzle.Initially the required energy around 1312 KJ/mol is carrying out the purpose of deuterium gas which is changed to ionization level.The ionized Deuterium gas comes out from RF ionization chamber to nozzle through MHD generator with enhanced velocity then after voltage is generated across the two pairs of electrode in MHD.it will produce thrust value with the help of mixing of Deuterium ion and Argon ion at acceleration position.The simulation of the IPR system has been carried out by MATLAB.By comparing the simulation results with the theoretical and previous results,if reaches that the proposed method is achieved of thrust value with 40KW power for simulating the IPR system.

  20. Advances in low energy neutral atom imaging techniques

    SciTech Connect

    Scime, E.E.; Funsten, H.O.; McComas, D.J.; Moore, K.R. ); Gruntman, M. . Space Sciences Center)

    1993-01-01

    Recently proposed low energy neutral atom (LENA) imaging techniques use a collisional process to convert the low energy neutrals into ions before detection. At low energies, collisional processes limit the angular resolution and conversion efficiencies of these devices. However, if the intense ultraviolet light background can be suppressed, direct LENA detection is possible. We present results from a series of experiments designed to develop a novel filtering structure based on free-standing transmission gratings. If the grating period is sufficiently small, free standing transmission gratings can be employed to substantially polarize ultraviolet (UV) light in the wavelength range 300 [Angstrom] to 1500 [Angstrom]. If a second grating is placed behind the first grating with its axis of polarization oriented at a right angle to the first's, a substantial attenuation of UV radiation is achievable. ne neutrals will pass through the remaining open area of two gratings and be detected without UV background complications. We have obtained nominal 2000 [Angstrom] period (1000 [Angstrom] bars with 1000 [Angstrom] slits) free standing, gold transmission gratings and measured their UV and atomic transmission characteristics. The geometric factor of a LENA imager based on this technology is comparable to that of other proposed LENA imagers. In addition, this of imager does not distort the neutral trajectories, allowing for high angular resolution.

  1. Advanced techniques for determining long term compatibility of materials with propellants

    NASA Technical Reports Server (NTRS)

    Green, R. L.; Stebbins, J. P.; Smith, A. W.; Pullen, K. E.

    1973-01-01

    A method for the prediction of propellant-material compatibility for periods of time up to ten years is presented. Advanced sensitive measurement techniques used in the prediction method are described. These include: neutron activation analysis, radioactive tracer technique, and atomic absorption spectroscopy with a graphite tube furnace sampler. The results of laboratory tests performed to verify the prediction method are presented.

  2. Biotechnology Apprenticeship for Secondary-Level Students: Teaching Advanced Cell Culture Techniques for Research

    ERIC Educational Resources Information Center

    Lewis, Jennifer R.; Kotur, Mark S.; Butt, Omar; Kulcarni, Sumant; Riley, Alyssa A.; Ferrell, Nick; Sullivan, Kathryn D.; Ferrari, Mauro

    2002-01-01

    The purpose of this article is to discuss "small-group apprenticeships (SGAs)" as a method to instruct cell culture techniques to high school participants. The study aimed to teach cell culture practices and to introduce advanced imaging techniques to solve various biomedical engineering problems. Participants designed and completed experiments…

  3. Advanced Techniques for Reservoir Simulation and Modeling of Non-Conventional Wells

    SciTech Connect

    Durlofsky, Louis J.

    2000-08-28

    This project targets the development of (1) advanced reservoir simulation techniques for modeling non-conventional wells; (2) improved techniques for computing well productivity (for use in reservoir engineering calculations) and well index (for use in simulation models), including the effects of wellbore flow; and (3) accurate approaches to account for heterogeneity in the near-well region.

  4. Biotechnology Apprenticeship for Secondary-Level Students: Teaching Advanced Cell Culture Techniques for Research.

    ERIC Educational Resources Information Center

    Lewis, Jennifer R.; Kotur, Mark S.; Butt, Omar; Kulcarni, Sumant; Riley, Alyssa A.; Ferrell, Nick; Sullivan, Kathryn D.; Ferrari, Mauro

    2002-01-01

    Discusses small-group apprenticeships (SGAs) as a method for introducing cell culture techniques to high school participants. Teaches cell culture practices and introduces advance imaging techniques to solve various biomedical engineering problems. Clarifies and illuminates the value of small-group laboratory apprenticeships. (Author/KHR)

  5. Noncontacting ultrasonic and electromagnetic HTS tape NDE

    SciTech Connect

    Telschow, K.L.; Bruneel, F.W.; Walter, J.B.; Koo, L.S.

    1996-10-01

    Two noncontacting nondestructive evaluation techniques (electromagnetic and ultrasonic) for inspection of high temperature superconducting tapes are described. Results for Ag-clad BSCCO tapes are given.

  6. Miscibility studies of Polyethylene Glycol with Polystyrene in Toluene by Various Physical and Advanced Techniques

    NASA Astrophysics Data System (ADS)

    Padmanaban, R.; Venkatramanan, K.

    2016-10-01

    Polyethylene glycol (PEG) is a chemical that has an extensive variety of applications in the world of medicine. It is used as a base to manufacture certain medicines, assist in drug delivery, and is also used as an agent in some medical procedures. It is an osmotic laxative. Polyethylene glycol works by retaining water in the stool, resulting in softer stools and more frequent bowel movements. Polyethylene glycol does not affect glucose and electrolytes in the body. PEG refers to a hydrocarbon molecule that can have a variable size, and different sizes can have different physical properties, giving this compound a great deal of flexibility in its application. In the present study, Polyethylene Glycol (PEG) (Molar mass: 1500) is blended with Polystyrene (PS) (Molar mass: 35000) in Toluene. The miscibility nature of the poly blend is analyzed by Ultrasonic velocity, viscosity, density and refractive index techniques at 303K. The compatibility nature of the blend is confirmed by Differential Scanning Calorimetry (DSC) studies.

  7. Further development of ultrasonic techniques for non-destructive evaluation based on Fourier analysis of signals from irregular and inhomogeneous structures

    NASA Technical Reports Server (NTRS)

    Miller, J. G.

    1979-01-01

    To investigate the use of Fourier analysis techniques model systems had to be designed to test some of the general properties of the interaction of sound with an inhomogeneity. The first models investigated were suspensions of solid spheres in water. These systems allowed comparison between theoretical computation of the frequency dependence of the attenuation coefficient and measurement of the attenuation coefficient over a range of frequencies. Ultrasonic scattering processes in both suspensions of hard spheres in water, and suspensions of hard spheres in polyester resin were investigated. The second model system was constructed to test the applicability of partial wave analysis to the description of an inhomogeneity in a solid, and to test the range of material properties over which the measurement systems were valid.

  8. Effect of precursor concentrations on structural, microstructural and optical properties of nanocrystalline ZnO powder synthesized by an ultrasonic atomization technique

    NASA Astrophysics Data System (ADS)

    Patil, L. A.; Bari, A. R.; Shinde, M. D.; Deo, Vinita; Kaushik, M. P.

    2010-09-01

    In this paper, we report on the effect of concentration on nanocrystalline ZnO powder prepared by an ultrasonic atomization technique, which is a promising method because of its simplicity, inexpensiveness and safety. The morphology and size of ZnO nanocrystallites associated with nanopowder were characterized by transmission electron microscopy (TEM). It revealed that the powder consisted of nanocrystallites with grain sizes between 8 and 15 nm. These values match the grain sizes (8-14 nm) calculated from x-ray diffraction (XRD). The XRD and TEM studies of ZnO nanopowder showed that crystallite sizes were observed to increase with an increase in the concentration of solution. The d values calculated from electron diffraction patterns (TEM) of ZnO nanopowder were also in agreement with the d values calculated from XRD. The synthesized nanopowders exhibited a direct band gap (Eg) in the range of 3.36-3.42 eV.

  9. Theory and application of ultrasonic microstructural characterization

    NASA Astrophysics Data System (ADS)

    Thompson, R. Bruce

    1992-10-01

    Ultrasonic microstructural characterization techniques have been developed for a variety of reasons ranging from process control to life extension. The techniques are based on principles of wave propagation and scattering from inhomogeneities. Applications of ultrasonic techniques include predicting sheet metal formability, controlling microstructure in metal-matrix composites, monitoring diffusion bonding, measuring porosity in castings and composites, and designing microstructures for enhanced inspectability.

  10. Enhanced ultrasonically assisted turning of a β-titanium alloy.

    PubMed

    Maurotto, Agostino; Muhammad, Riaz; Roy, Anish; Silberschmidt, Vadim V

    2013-09-01

    Although titanium alloys have outstanding mechanical properties such as high hot hardness, a good strength-to-weight ratio and high corrosion resistance; their low thermal conductivity, high chemical affinity to tool materials severely impair their machinability. Ultrasonically assisted machining (UAM) is an advanced machining technique, which has been shown to improve machinability of a β-titanium alloy, namely, Ti-15-3-3-3, when compared to conventional turning processes.

  11. New simple technique for hepatic parenchymal resection using a Cavitron Ultrasonic Surgical Aspirator and bipolar cautery equipped with a channel for water dripping.

    PubMed

    Yamamoto, Y; Ikai, I; Kume, M; Sakai, Y; Yamauchi, A; Shinohara, H; Morimoto, T; Shimahara, Y; Yamamoto, M; Yamaoka, Y

    1999-10-01

    We have developed a new technique to resect hepatic parenchyma without inflow occlusion by using the Cavitron Ultrasonic Surgical Aspirator (CUSA) and bipolar cautery with a saline irrigation system. The significance of this method in hepatectomy was analyzed in comparison with historical control of hepatectomy using Pringle's maneuver. An ordinary bipolar cautery was remodeled with an infusion line to bring saline droplets down the inner surface of one arm of the tweezers through an opening about 1.5 cm proximal to its tip. The optimal flow rate of saline was approximately one drop per second. The power of bipolar cautery was adjusted to 50 watts. When the tweezer blades were approximated to 1 or 2 mm, saline droplets were directed to the tip of tweezers and could be immediately evaporated. After sonicating parenchymal cells, the tissue of small branches of Glisson's tree or small tributaries of the hepatic vein were coagulated by bipolar cautery. The coagulated cords were then easily cut by scissors. The impact of this technique on ordinary liver resections was evaluated by analyzing the postoperative clinical course in relation to the hepatic functional reserve necessary for major hepatectomy, duration of hepatectomy, and intraoperative blood loss. Hepatic resection without vascular occlusion using this technique could decrease the morbidity in patients who have less hepatic functional reserve. It could also decrease intraoperative blood loss. This new technique effectively decreased the surgical load of the remnant liver during parenchymal resection by avoiding ischemic stress. Consequently it extends the safety limits of major hepatectomy.

  12. Ultrasonic Maintenance

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The Ultraprobe 2000, manufactured by UE Systems, Inc., Elmsford, NY, is a hand-held ultrasonic system that detects indications of bearing failure by analyzing changes in amplitude. It employs the technology of a prototype ultrasonic bearing-failure monitoring system developed by Mechanical Technology, Inc., Latham, New York and Marshall Space Flight Center (which was based on research into Skylab's gyroscope bearings). Bearings on the verge of failure send ultrasonic signals indicating their deterioration; the Ultraprobe changes these to audible signals. The operator hears the signals and gages their intensity with a meter in the unit.

  13. A Novel Microcharacterization Technique in the Measurement of Strain and Orientation Gradient in Advanced Materials

    NASA Technical Reports Server (NTRS)

    Garmestai, H.; Harris, K.; Lourenco, L.

    1997-01-01

    Representation of morphology and evolution of the microstructure during processing and their relation to properties requires proper experimental techniques. Residual strains, lattice distortion, and texture (micro-texture) at the interface and the matrix of a layered structure or a functionally gradient material and their variation are among parameters important in materials characterization but hard to measure with present experimental techniques. Current techniques available to measure changes in interred material parameters (residual stress, micro-texture, microplasticity) produce results which are either qualitative or unreliable. This problem becomes even more complicated in the case of a temperature variation. These parameters affect many of the mechanical properties of advanced materials including stress-strain relation, ductility, creep, and fatigue. A review of some novel experimental techniques using recent advances in electron microscopy is presented here to measure internal stress, (micro)texture, interracial strength and (sub)grain formation and realignment. Two of these techniques are combined in the chamber of an Environmental Scanning Electron Microscope to measure strain and orientation gradients in advanced materials. These techniques which include Backscattered Kikuchi Diffractometry (BKD) and Microscopic Strain Field Analysis are used to characterize metallic and intermetallic matrix composites and superplastic materials. These techniques are compared with the more conventional x-ray diffraction and indentation techniques.

  14. Acousto-ultrasonics

    NASA Technical Reports Server (NTRS)

    Vary, Alex

    1990-01-01

    The theoretical development, methodology, and potential applications of acousto-ultrasonic nondestructive testing are set forth in an overview to assess the effectiveness of the technique. Stochastic wave propagation is utilized to isolate and describe defects in fiber-reinforced composites, particularly emphasizing the integrated effects of diffuse populations of subcritical flaws. The generation and nature of acousto-ultrasonic signals are described in detail, and stress-wave factor analysis of the signals is discussed. Applications of acousto-ultrasonics are listed including the prediction of failure sites, assessing fatique and impact damage, calculating ultimate tensile strength, and determining interlaminar bond strength. The method can identify subtle but important variations in fiber-reinforced composites, and development of the related instrumentation technology is emphasized.

  15. Ultrasonics in Dentistry

    NASA Astrophysics Data System (ADS)

    Walmsley, A. D.

    Ultrasonic instruments have been used in dentistry since the 1950's. Initially they were used to cut teeth but very quickly they became established as an ultrasonic scaler which was used to remove deposits from the hard tissues of the tooth. This enabled the soft tissues around the tooth to return to health. The ultrasonic vibrations are generated in a thin metal probe and it is the working tip that is the active component of the instrument. Scanning laser vibrometry has shown that there is much variability in their movement which is related to the shape and cross sectional shape of the probe. The working instrument will also generate cavitation and microstreaming in the associated cooling water. This can be mapped out along the length of the instrument indicating which are the active areas. Ultrasonics has also found use for cleaning often inaccessible or different surfaces including root canal treatment and dental titanium implants. The use of ultrasonics to cut bone during different surgical techniques shows considerable promise. More research is indicated to determine how to maximize the efficiency of such instruments so that they are more clinically effective.

  16. Cationic polyelectrolyte/bentonite prepared by ultrasonic technique and its use as adsorbent for Reactive Blue K-GL dye.

    PubMed

    Li, Qian; Yue, Qin-Yan; Su, Yuan; Gao, Bao-Yu; Fu, Lin

    2007-08-17

    In this study, the cationic polyelectrolyte polyepicholorohydrin-dimethylamine (EPI-DMA) was intercalated into bentonite using ultrasonic. The structure of EPI-DMA/bentonite and its adsorption of Reactive Blue K-GL (RB K-GL) dye were investigated. Compared with raw bentonite, the EPI-DMA/bentonite had larger interlayer spacing and was more hydrophobic, providing with better surface properties for adsorption. The adsorption of RB K-GL on EPI-DMA/bentonite was described by the adsorption models of Langmuir, Freundlich and Dubinin-Radushkevic. The adsorption kinetics was analyzed using pseudo-first- and second-order kinetic models and intraparticle diffusion model. Results showed that both the intraparticle diffusion and first-order adsorption occur in the initial period of adsorption, and that pseudo-second-order kinetic model was more suitable for describing the whole adsorption process. The reaction rates were also calculated. The changes of free energy, enthalpy and entropy of adsorption were evaluated for the adsorption of RB K-GL onto EPI-DMA/bentonite, suggesting that the adsorption process was spontaneous and exothermic.

  17. Modulation/demodulation techniques for satellite communications. Part 2: Advanced techniques. The linear channel

    NASA Technical Reports Server (NTRS)

    Omura, J. K.; Simon, M. K.

    1982-01-01

    A theory is presented for deducing and predicting the performance of transmitter/receivers for bandwidth efficient modulations suitable for use on the linear satellite channel. The underlying principle used is the development of receiver structures based on the maximum-likelihood decision rule. The application of the performance prediction tools, e.g., channel cutoff rate and bit error probability transfer function bounds to these modulation/demodulation techniques.

  18. Advanced combustion techniques for controlling NO sub x emissions of high altitude cruise aircraft

    NASA Technical Reports Server (NTRS)

    Rudey, R. A.; Reck, G. M.

    1976-01-01

    An array of experiments designed to explore the potential of advanced combustion techniques for controlling the emissions of aircraft into the upper atmosphere was discussed. Of particular concern are the oxides of nitrogen (NOx) emissions into the stratosphere. The experiments utilize a wide variety of approaches varying from advanced combustor concepts to fundamental flame tube experiments. Results are presented which indicate that substantial reductions in cruise NOx emissions should be achievable in future aircraft engines. A major NASA program is described which focuses the many fundamental experiments into a planned evolution and demonstration of the prevaporized-premixed combustion technique in a full-scale engine.

  19. POC-Scale Testing of an Advanced Fine Coal Dewatering Equipment/Technique

    SciTech Connect

    Karekh, B K; Tao, D; Groppo, J G

    1998-08-28

    Froth flotation technique is an effective and efficient process for recovering of ultra-fine (minus 74 mm) clean coal. Economical dewatering of an ultra-fine clean coal product to a 20% level moisture will be an important step in successful implementation of the advanced cleaning processes. This project is a step in the Department of Energy's program to show that ultra-clean coal could be effectively dewatered to 20% or lower moisture using either conventional or advanced dewatering techniques. The cost-sharing contract effort is for 45 months beginning September 30, 1994. This report discusses technical progress made during the quarter from January 1 - March 31, 1998.

  20. Quantitative ultrasonic evaluation of mechanical properties of engineering materials

    NASA Technical Reports Server (NTRS)

    Vary, A.

    1978-01-01

    Current progress in the application of ultrasonic techniques to nondestructive measurement of mechanical strength properties of engineering materials is reviewed. Even where conventional NDE techniques have shown that a part is free of overt defects, advanced NDE techniques should be available to confirm the material properties assumed in the part's design. There are many instances where metallic, composite, or ceramic parts may be free of critical defects while still being susceptible to failure under design loads due to inadequate or degraded mechanical strength. This must be considered in any failure prevention scheme that relies on fracture analysis. This review will discuss the availability of ultrasonic methods that can be applied to actual parts to assess their potential susceptibility to failure under design conditions.

  1. Modulation/demodulation techniques for satellite communications. Part 3: Advanced techniques. The nonlinear channel

    NASA Technical Reports Server (NTRS)

    Omura, J. K.; Simon, M. K.

    1982-01-01

    A theory for deducing and predicting the performance of transmitter/receivers for bandwidth efficient modulations suitable for use on the nonlinear satellite channel is presented. The underlying principle used throughout is the development of receiver structures based on the maximum likelihood decision rule and aproximations to it. The bit error probability transfer function bounds developed in great detail in Part 4 is applied to these modulation/demodulation techniques. The effects of the various degrees of receiver mismatch are considered both theoretically and by numerous illustrative examples.

  2. Application of Advanced Magnetic Resonance Imaging Techniques in Evaluation of the Lower Extremity

    PubMed Central

    Braun, Hillary J.; Dragoo, Jason L.; Hargreaves, Brian A.; Levenston, Marc E.; Gold, Garry E.

    2012-01-01

    Synopsis This article reviews current magnetic resonance imaging techniques for imaging the lower extremity, focusing on imaging of the knee, ankle, and hip joints. Recent advancements in MRI include imaging at 7 Tesla, using multiple receiver channels, T2* imaging, and metal suppression techniques, allowing more detailed visualization of complex anatomy, evaluation of morphological changes within articular cartilage, and imaging around orthopedic hardware. PMID:23622097

  3. Advances in neutron radiographic techniques and applications: a method for nondestructive testing.

    PubMed

    Berger, Harold

    2004-10-01

    A brief history of neutron radiography is presented to set the stage for a discussion of significant neutron radiographic developments and an assessment of future directions for neutron radiography. Specific advances are seen in the use of modern, high dynamic range imaging methods (image plates and flat panels) and for high contrast techniques such as phase contrast, and phase-sensitive imaging. Competition for neutron radiographic inspection may develop as these techniques offer application prospects for X-ray methods.

  4. Ultrasonic Transducer Irradiation Test Results

    SciTech Connect

    Daw, Joshua; Palmer, Joe; Ramuhalli, Pradeep; Keller, Paul; Montgomery, Robert; Chien, Hual-Te; Kohse, Gordon; Tittmann, Bernhard; Reinhardt, Brian; Rempe, Joy

    2015-02-01

    Ultrasonic technologies offer the potential for high-accuracy and -resolution in-pile measurement of a range of parameters, including geometry changes, temperature, crack initiation and growth, gas pressure and composition, and microstructural changes. Many Department of Energy-Office of Nuclear Energy (DOE-NE) programs are exploring the use of ultrasonic technologies to provide enhanced sensors for in-pile instrumentation during irradiation testing. For example, the ability of small diameter ultrasonic thermometers (UTs) to provide a temperature profile in candidate metallic and oxide fuel would provide much needed data for validating new fuel performance models. Other ongoing efforts include an ultrasonic technique to detect morphology changes (such as crack initiation and growth) and acoustic techniques to evaluate fission gas composition and pressure. These efforts are limited by the lack of identified ultrasonic transducer materials capable of long term performance under irradiation test conditions. For this reason, the Pennsylvania State University (PSU) was awarded an ATR NSUF project to evaluate the performance of promising magnetostrictive and piezoelectric transducers in the Massachusetts Institute of Technology Research Reactor (MITR) up to a fast fluence of at least 1021 n/cm2. The goal of this research is to characterize and demonstrate magnetostrictive and piezoelectric transducer operation during irradiation, enabling the development of novel radiation-tolerant ultrasonic sensors for use in Material Testing Reactors (MTRs). As such, this test is an instrumented lead test and real-time transducer performance data is collected along with temperature and neutron and gamma flux data. The current work bridges the gap between proven out-of-pile ultrasonic techniques and in-pile deployment of ultrasonic sensors by acquiring the data necessary to demonstrate the performance of ultrasonic transducers. To date, one piezoelectric

  5. Analytical ultrasonics for structural materials

    NASA Technical Reports Server (NTRS)

    Kupperman, D. S.

    1986-01-01

    The application of ultrasonic velocity and attenuation measurements to characterize the microstructure of structural materials is discussed. Velocity measurements in cast stainless steel are correlated with microstructural variations ranging from equiaxed (elastically isotropic) to columnar (elastically anisotropic) grain structure. The effect of the anisotropic grain structure on the deviation of ultrasonic waves in cast stainless steel is also reported. Field-implementable techniques for distinguishing equiaxed from columnar grain structures in cast strainless steel structural members are presented. The application of ultrasonic velocity measurements to characterize structural ceramics in the green state is also discussed.

  6. Advanced techniques for high resolution spectroscopic observations of cosmic gamma-ray sources

    NASA Technical Reports Server (NTRS)

    Matteson, J. L.; Pelling, M. R.; Peterson, L. E.; Lin, R. P.; Anderson, K. A.; Pehl, R. H.; Hurley, K. C.; Vedrenne, G.; Sniel, M.; Durouchoux, P.

    1985-01-01

    An advanced gamma-ray spectrometer that is currently in development is described. It will obtain a sensitivity of 0.0001 ph/sq cm./sec in a 6 hour balloon observation and uses innovative techniques for background reduction and source imaging.

  7. Recognizing and Managing Complexity: Teaching Advanced Programming Concepts and Techniques Using the Zebra Puzzle

    ERIC Educational Resources Information Center

    Crabtree, John; Zhang, Xihui

    2015-01-01

    Teaching advanced programming can be a challenge, especially when the students are pursuing different majors with diverse analytical and problem-solving capabilities. The purpose of this paper is to explore the efficacy of using a particular problem as a vehicle for imparting a broad set of programming concepts and problem-solving techniques. We…

  8. Real-time application of advanced three-dimensional graphic techniques for research aircraft simulation

    NASA Technical Reports Server (NTRS)

    Davis, Steven B.

    1990-01-01

    Visual aids are valuable assets to engineers for design, demonstration, and evaluation. Discussed here are a variety of advanced three-dimensional graphic techniques used to enhance the displays of test aircraft dynamics. The new software's capabilities are examined and possible future uses are considered.

  9. Fabrication of advanced electrochemical energy materials using sol-gel processing techniques

    NASA Technical Reports Server (NTRS)

    Chu, C. T.; Chu, Jay; Zheng, Haixing

    1995-01-01

    Advanced materials play an important role in electrochemical energy devices such as batteries, fuel cells, and electrochemical capacitors. They are being used as both electrodes and electrolytes. Sol-gel processing is a versatile solution technique used in fabrication of ceramic materials with tailored stoichiometry, microstructure, and properties. The application of sol-gel processing in the fabrication of advanced electrochemical energy materials will be presented. The potentials of sol-gel derived materials for electrochemical energy applications will be discussed along with some examples of successful applications. Sol-gel derived metal oxide electrode materials such as V2O5 cathodes have been demonstrated in solid-slate thin film batteries; solid electrolytes materials such as beta-alumina for advanced secondary batteries had been prepared by the sol-gel technique long time ago; and high surface area transition metal compounds for capacitive energy storage applications can also be synthesized with this method.

  10. Ultrasonic NDE Simulation for Composite Manufacturing Defects

    NASA Technical Reports Server (NTRS)

    Leckey, Cara A. C.; Juarez, Peter D.

    2016-01-01

    The increased use of composites in aerospace components is expected to continue into the future. The large scale use of composites in aerospace necessitates the development of composite-appropriate nondestructive evaluation (NDE) methods to quantitatively characterize defects in as-manufactured parts and damage incurred during or post manufacturing. Ultrasonic techniques are one of the most common approaches for defect/damage detection in composite materials. One key technical challenge area included in NASA's Advanced Composite's Project is to develop optimized rapid inspection methods for composite materials. Common manufacturing defects in carbon fiber reinforced polymer (CFRP) composites include fiber waviness (in-plane and out-of-plane), porosity, and disbonds; among others. This paper is an overview of ongoing work to develop ultrasonic wavefield based methods for characterizing manufacturing waviness defects. The paper describes the development and implementation of a custom ultrasound simulation tool that is used to model ultrasonic wave interaction with in-plane fiber waviness (also known as marcelling). Wavefield data processing methods are applied to the simulation data to explore possible routes for quantitative defect characterization.

  11. Computer Automated Ultrasonic Inspection System

    DTIC Science & Technology

    1985-02-06

    Microcomputer CRT Cathode Ray Tube SBC Single Board Computer xiii 1.0 INTRODUCTION 1.1 Background Standard ultrasonic inspection techniques used in industry...30 Microcomputer The heart of the bridge control microcomputer is an Intel single board computer using a high-speed 8085 HA-2 microprocessor chip ...subsystems (bridge, bridge drive electronics, bridge control microcomputer , ultrasonic unit, and master computer system), development of bridge control and

  12. Ultrasonic Polishing

    NASA Technical Reports Server (NTRS)

    Gilmore, Randy

    1993-01-01

    The ultrasonic polishing process makes use of the high-frequency (ultrasonic) vibrations of an abradable tool which automatically conforms to the work piece and an abrasive slurry to finish surfaces and edges on complex, highly detailed, close tolerance cavities in materials from beryllium copper to carbide. Applications range from critical deburring of guidance system components to removing EDM recast layers from aircraft engine components to polishing molds for forming carbide cutting tool inserts or injection molding plastics. A variety of materials including tool steels, carbides, and even ceramics can be successfully processed. Since the abradable tool automatically conforms to the work piece geometry, the ultrasonic finishing method described offers a number of important benefits in finishing components with complex geometries.

  13. Ultrasonic neuromodulation

    NASA Astrophysics Data System (ADS)

    Naor, Omer; Krupa, Steve; Shoham, Shy

    2016-06-01

    Ultrasonic waves can be non-invasively steered and focused into mm-scale regions across the human body and brain, and their application in generating controlled artificial modulation of neuronal activity could therefore potentially have profound implications for neural science and engineering. Ultrasonic neuro-modulation phenomena were experimentally observed and studied for nearly a century, with recent discoveries on direct neural excitation and suppression sparking a new wave of investigations in models ranging from rodents to humans. In this paper we review the physics, engineering and scientific aspects of ultrasonic fields, their control in both space and time, and their effect on neuronal activity, including a survey of both the field’s foundational history and of recent findings. We describe key constraints encountered in this field, as well as key engineering systems developed to surmount them. In closing, the state of the art is discussed, with an emphasis on emerging research and clinical directions.

  14. Advanced techniques for determining long term compatibility of materials with propellants

    NASA Technical Reports Server (NTRS)

    Green, R. L.

    1972-01-01

    The search for advanced measurement techniques for determining long term compatibility of materials with propellants was conducted in several parts. A comprehensive survey of the existing measurement and testing technology for determining material-propellant interactions was performed. Selections were made from those existing techniques which were determined could meet or be made to meet the requirements. Areas of refinement or changes were recommended for improvement of others. Investigations were also performed to determine the feasibility and advantages of developing and using new techniques to achieve significant improvements over existing ones. The most interesting demonstration was that of the new technique, the volatile metal chelate analysis. Rivaling the neutron activation analysis in terms of sensitivity and specificity, the volatile metal chelate technique was fully demonstrated.

  15. Recent advances in 3D computed tomography techniques for simulation and navigation in hepatobiliary pancreatic surgery.

    PubMed

    Uchida, Masafumi

    2014-04-01

    A few years ago it could take several hours to complete a 3D image using a 3D workstation. Thanks to advances in computer science, obtaining results of interest now requires only a few minutes. Many recent 3D workstations or multimedia computers are equipped with onboard 3D virtual patient modeling software, which enables patient-specific preoperative assessment and virtual planning, navigation, and tool positioning. Although medical 3D imaging can now be conducted using various modalities, including computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET), and ultrasonography (US) among others, the highest quality images are obtained using CT data, and CT images are now the most commonly used source of data for 3D simulation and navigation image. If the 2D source image is bad, no amount of 3D image manipulation in software will provide a quality 3D image. In this exhibition, the recent advances in CT imaging technique and 3D visualization of the hepatobiliary and pancreatic abnormalities are featured, including scan and image reconstruction technique, contrast-enhanced techniques, new application of advanced CT scan techniques, and new virtual reality simulation and navigation imaging.

  16. An experimental study on the characteristics of wind-driven surface water film flows by using a multi-transducer ultrasonic pulse-echo technique

    NASA Astrophysics Data System (ADS)

    Liu, Yang; Chen, Wen-Li; Bond, Leonard J.; Hu, Hui

    2017-01-01

    An experimental study was conducted to investigate the characteristics of surface water film flows driven by boundary layer winds over a test plate in order to elucidate the underlying physics pertinent to dynamic water runback processes over ice accreting surfaces of aircraft wings. A multi-transducer ultrasonic pulse-echo (MTUPE) technique was developed and applied to achieve non-intrusive measurements of water film thickness as a function of time and space to quantify the transient behaviors of wind-driven surface water film flows. The effects of key controlling parameters, including freestream velocity of the airflow and flow rate of the water film, on the dynamics of the surface water runback process were examined in great details based on the quantitative MTUPE measurements. While the thickness of the wind-driven surface water film was found to decrease rapidly with the increasing airflow velocity, various surface wave structures were also found to be generated at the air/water interface as the surface water runs back. The evolution of the surface wave structures, in the terms of wave shape, frequency and propagation velocity of the surface waves, and instability modes (i.e., well-organized 2-D waves vs. 3-D complex irregular waves), was found to change significantly as the airflow velocity increases. Such temporally synchronized and spatially resolved measurements are believed to be very helpful to elucidate the underlying physics for improved understanding of the dynamics of water runback process pertinent to aircraft icing phenomena.

  17. Ultrasonic Bonding of Solar-Cell Leads

    NASA Technical Reports Server (NTRS)

    Frasch, W.

    1984-01-01

    Rolling ultrasonic spot-bonding method successfully joins aluminum interconnect fingers to silicon solar cells with copper metalization. Technique combines best features of ultrasonic rotary seam welding and ultrasonic spot bonding: allows fast bond cycles and high indexing speeds without use of solder or flux. Achieves reliable bonds at production rates without damage to solar cells. Bonding system of interest for all solar-cell assemblies and other assemblies using flat leads (rather than round wires).

  18. Cement-based materials' characterization using ultrasonic attenuation

    NASA Astrophysics Data System (ADS)

    Punurai, Wonsiri

    The quantitative nondestructive evaluation (NDE) of cement-based materials is a critical area of research that is leading to advances in the health monitoring and condition assessment of the civil infrastructure. Ultrasonic NDE has been implemented with varying levels of success to characterize cement-based materials with complex microstructure and damage. A major issue with the application of ultrasonic techniques to characterize cement-based materials is their inherent inhomogeneity at multiple length scales. Ultrasonic waves propagating in these materials exhibit a high degree of attenuation losses, making quantitative interpretations difficult. Physically, these attenuation losses are a combination of internal friction in a viscoelastic material (ultrasonic absorption), and the scattering losses due to the material heterogeneity. The objective of this research is to use ultrasonic attenuation to characterize the microstructure of heterogeneous cement-based materials. The study considers a real, but simplified cement-based material, cement paste---a common bonding matrix of all cement-based composites. Cement paste consists of Portland cement and water but does not include aggregates. First, this research presents the findings of a theoretical study that uses a set of existing acoustics models to quantify the scattered ultrasonic wavefield from a known distribution of entrained air voids. These attenuation results are then coupled with experimental measurements to develop an inversion procedure that directly predicts the size and volume fraction of entrained air voids in a cement paste specimen. Optical studies verify the accuracy of the proposed inversion scheme. These results demonstrate the effectiveness of using attenuation to measure the average size, volume fraction of entrained air voids and the existence of additional larger entrapped air voids in hardened cement paste. Finally, coherent and diffuse ultrasonic waves are used to develop a direct

  19. Ultrasonic test system

    NASA Astrophysics Data System (ADS)

    Smith, Anthony; Goff, Dan; Kruchowy, Roman; Rhoads, Carl

    1994-08-01

    An ultrasonic system for determining the quality of concrete under water without inaccuracies caused by electromagnetic interference from the ultrasonic generator. An ultrasonic generator applies pulses to the concrete. An ultrasonic detector detects the ultrasonic pulses and produces corresponding signals that are indicative of ultrasonic pulses that have passed through the material. Signal processing circuitry processes the signals to determine the transit time of the ultrasonic pulses through the material. The signal processing circuitry is disabled for a predetermined time after application of each ultrasonic pulse to the material to prevent noise produced by the means for applying ultrasonic pulses to the material from entering the signal processing circuitry and causing spurious measurements.

  20. Recent Advances in Techniques for Starch Esters and the Applications: A Review

    PubMed Central

    Hong, Jing; Zeng, Xin-An; Brennan, Charles S.; Brennan, Margaret; Han, Zhong

    2016-01-01

    Esterification is one of the most important methods to alter the structure of starch granules and improve its applications. Conventionally, starch esters are prepared by conventional or dual modification techniques, which have the disadvantages of being expensive, have regent overdoses, and are time-consuming. In addition, the degree of substitution (DS) is often considered as the primary factor in view of its contribution to estimate substituted groups of starch esters. In order to improve the detection accuracy and production efficiency, different detection techniques, including titration, nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FT-IR), thermal gravimetric analysis/infrared spectroscopy (TGA/IR) and headspace gas chromatography (HS-GC), have been developed for DS. This paper gives a comprehensive overview on the recent advances in DS analysis and starch esterification techniques. Additionally, the advantages, limitations, some perspectives on future trends of these techniques and the applications of their derivatives in the food industry are also presented. PMID:28231145

  1. Advances in the surface modification techniques of bone-related implants for last 10 years

    PubMed Central

    Qiu, Zhi-Ye; Chen, Cen; Wang, Xiu-Mei; Lee, In-Seop

    2014-01-01

    At the time of implanting bone-related implants into human body, a variety of biological responses to the material surface occur with respect to surface chemistry and physical state. The commonly used biomaterials (e.g. titanium and its alloy, Co–Cr alloy, stainless steel, polyetheretherketone, ultra-high molecular weight polyethylene and various calcium phosphates) have many drawbacks such as lack of biocompatibility and improper mechanical properties. As surface modification is very promising technology to overcome such problems, a variety of surface modification techniques have been being investigated. This review paper covers recent advances in surface modification techniques of bone-related materials including physicochemical coating, radiation grafting, plasma surface engineering, ion beam processing and surface patterning techniques. The contents are organized with different types of techniques to applicable materials, and typical examples are also described. PMID:26816626

  2. Recent Advances in Techniques for Starch Esters and the Applications: A Review.

    PubMed

    Hong, Jing; Zeng, Xin-An; Brennan, Charles S; Brennan, Margaret; Han, Zhong

    2016-07-09

    Esterification is one of the most important methods to alter the structure of starch granules and improve its applications. Conventionally, starch esters are prepared by conventional or dual modification techniques, which have the disadvantages of being expensive, have regent overdoses, and are time-consuming. In addition, the degree of substitution (DS) is often considered as the primary factor in view of its contribution to estimate substituted groups of starch esters. In order to improve the detection accuracy and production efficiency, different detection techniques, including titration, nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FT-IR), thermal gravimetric analysis/infrared spectroscopy (TGA/IR) and headspace gas chromatography (HS-GC), have been developed for DS. This paper gives a comprehensive overview on the recent advances in DS analysis and starch esterification techniques. Additionally, the advantages, limitations, some perspectives on future trends of these techniques and the applications of their derivatives in the food industry are also presented.

  3. Unified Instrumentation: Examining the Simultaneous Application of Advanced Measurement Techniques for Increased Wind Tunnel Testing Capability

    NASA Technical Reports Server (NTRS)

    Fleming, Gary A. (Editor); Bartram, Scott M.; Humphreys, William M., Jr.; Jenkins, Luther N.; Jordan, Jeffrey D.; Lee, Joseph W.; Leighty, Bradley D.; Meyers, James F.; South, Bruce W.; Cavone, Angelo A.; Ingram, JoAnne L.

    2002-01-01

    A Unified Instrumentation Test examining the combined application of Pressure Sensitive Paint, Projection Moire Interferometry, Digital Particle Image Velocimetry, Doppler Global Velocimetry, and Acoustic Microphone Array has been conducted at the NASA Langley Research Center. The fundamental purposes of conducting the test were to: (a) identify and solve compatibility issues among the techniques that would inhibit their simultaneous application in a wind tunnel, and (b) demonstrate that simultaneous use of advanced instrumentation techniques is feasible for increasing tunnel efficiency and identifying control surface actuation / aerodynamic reaction phenomena. This paper provides summary descriptions of each measurement technique used during the Unified Instrumentation Test, their implementation for testing in a unified fashion, and example results identifying areas of instrument compatibility and incompatibility. Conclusions are drawn regarding the conditions under which the measurement techniques can be operated simultaneously on a non-interference basis. Finally, areas requiring improvement for successfully applying unified instrumentation in future wind tunnel tests are addressed.

  4. The development of an interpretive methodology for the application of real-time acousto-ultrasonic NDE technique for monitoring damage in ceramic composites under dynamic loads

    NASA Astrophysics Data System (ADS)

    Tiwari, Anil

    Research effort was directed towards developing a near real-time acousto-ultrasonic (AU), nondestructive evaluation (NDE) tool study the failure mechanisms of ceramic composites. Progression damage is monitored in real-time by observing the changes in the received AU signal during the actual test. During the real-time AU test the AU signals are generated and received by the AU transducers attached to the specimen while it is being subjected to increasing quasi static loads or cyclic loads (10 Hz, R = 0.1). The received AU signals for 64 successive pulses were gated in the time domain (T = 40.96) and then averaged every second over ten load cycles and store in a computer file during fatigue tests. These averaged gated signal are representative of the damage state of the specimen at that point c its fatigue life. This is also the first major attempt in the development and application of real-time AU for continuously monitoring damage accumulation during fatigue without interrupting the test. The present work has verified the capability of the AU technique to assess the damage state in silicon carbide/calcium aluminosilicatt (SiC/CAS) and silicon carbide/magnesium aluminosilicate (SiC/MAS) ceramic composites. Continuous monitoring of damage initiation and progression under quasi-static ramp loading in tension to failure of unidirectional and cross-ply SiC/CAS and quasi-isotropic SiC/MAS ceramic composite specimens at room temperature was accomplished using near real-time AU parameters. The AU technique was shown to be able to detect the stress levels for the onset and saturation of matrix cracks, respectively. The critical cracking stress level is used as a design stress for brittle matrix composites operating at elevated temperatures. The AU technique has found that the critical cracking stress level is 10-15 percent below the level presently obtained for design purposes from analytical models. An acousto-ultrasonic stress-strain response (AUSSR) model for

  5. Assessment of weld quality of aerospace grade metals by using ultrasonic matrix phased array technology

    NASA Astrophysics Data System (ADS)

    Na, Jeong K.; Gleeson, Sean T.

    2014-03-01

    Advantages of two dimensional electronic ultrasonic beam focusing, steering and scanning with the matrix phased array (MPA) technology has been used to visualize the conditions of resistance spot welds in auto vehicle grade advanced high strength steel carbon steels nondestructively. Two of the commonly used joining techniques, resistance spot welding and resistance seam welding, for thin aerospace grade plates made of aluminum, titanium, and stainless steels have also been inspected with the same MPA NDE system. In this study, a detailed discussions of the current MPA based ultrasonic real time imaging methodology has been made followed by some of the NDT results obtained with various welded test coupons.

  6. Advanced combustion techniques for controlling NO/x/ emissions of high altitude cruise aircraft

    NASA Technical Reports Server (NTRS)

    Rudey, R. A.; Reck, G. M.

    1976-01-01

    An array of experiments have been and continue to be sponsored and conducted by NASA to explore the potential of advanced combustion techniques for controlling the emissions of aircraft into the upper atmosphere. Of particular concern are the oxides of nitrogen (NO/x/) emissions into the stratosphere. The experiments utilize a wide variety of approaches varying from advanced combustor concepts to fundamental flame tube experiments. Results are presented which indicate that substantial reductions in cruise NO/x/ emissions should be achievable in future aircraft engines. A major NASA program is described which focuses the many fundamental experiments into a planned evolution and demonstration of the prevaporized-premixed combustion technique in a full-scale engine.

  7. POC-scale testing of an advanced fine coal dewatering equipment/technique

    SciTech Connect

    1998-09-01

    Froth flotation technique is an effective and efficient process for recovering of ultra-fine (minus 74 pm) clean coal. Economical dewatering of an ultra-fine clean-coal product to a 20% level moisture will be an important step in successful implementation of the advanced cleaning processes. This project is a step in the Department of Energy`s program to show that ultra-clean coal could be effectively dewatered to 20% or lower moisture using either conventional or advanced dewatering techniques. The cost-sharing contract effort is for 36 months beginning September 30, 1994. This report discusses technical progress made during the quarter from July 1 - September 30, 1997.

  8. Imaging of skull base pathologies: Role of advanced magnetic resonance imaging techniques

    PubMed Central

    Mathur, Ankit; Kesavadas, C; Thomas, Bejoy; Kapilamoorthy, TR

    2015-01-01

    Imaging plays a vital role in evaluation of skull base pathologies as this region is not directly accessible for clinical evaluation. Computerized tomography (CT) and magnetic resonance imaging (MRI) have played complementary roles in the diagnosis of the various neoplastic and non-neoplastic lesions of the skull base. However, CT and conventional MRI may at times be insufficient to correctly pinpoint the accurate diagnosis. Advanced MRI techniques, though difficult to apply in the skull base region, in conjunction with CT and conventional MRI can however help in improving the diagnostic accuracy. This article aims to highlight the importance of advanced MRI techniques like diffusion-weighted imaging, susceptibility-weighted imaging, perfusion-weighted imaging, and MR spectroscopy in differentiation of various lesions involving the skull base. PMID:26427895

  9. Ultrasonic Microtransport

    NASA Astrophysics Data System (ADS)

    Moroney, Richard Morgan, III

    We have observed numerous kinetic effects using ultrasonic flexural plate waves (FPWs) in 4mu -thick composite plates of low-stress silicon nitride, piezoelectric zinc oxide and aluminum. The wavelength is typically 100 mum, and the area 3 x 8 mm^2. A successful new surface micromachining fabrication process is presented here for the first time. FPWs have been used to move liquids and gasses with motion typically indicated by polysilicon blocks in air and polystyrene spheres in water; the velocity in air is 4.5 mm/s (with a zero-to-peak input of 3 V), and in water it is 100 mum/s (with an input of 7.8 V). Other observations include pumping of a liquid dye, and mixing near the FPW surface. All quantitative observations demonstrate that the kinetic effects of FPWs are proportional to the square of the wave amplitude. The amplitude for a typical device is 250 A at 9 V input; the power in a typical FPW is about 2 mW. The amplitude can be accurately measured using a laser diffraction technique. Experimental error is about +/-10%, and many of the results agree well with a simple theory to predict the FPW amplitude; extensions of the theory model the fluid loading of FPW devices, but experiment and theory disagree by about 15%. Pumping by flexural plate waves is an example of the phenomenon known as acoustic streaming. A common solution approach is the method of successive approximations, where the nonlinear equations are first linearized and solved. This "first-order" solution is then used to determine the inhomogeneous source terms in the linearized, "second -order" equations of motion. Theoretical predictions of streaming theory are in excellent agreement with experiment in the case where the FPW device contacts a half-space of fluid; predictions for flow in small channels encourage the development of integrated micropumps. Applications for microflow include thermal redistribution in integrated circuits and liquid movement in analytical instruments--particularly where

  10. New test techniques and analytical procedures for understanding the behavior of advanced propellers

    NASA Technical Reports Server (NTRS)

    Stefko, G. L.; Bober, L. J.; Neumann, H. E.

    1983-01-01

    Analytical procedures and experimental techniques were developed to improve the capability to design advanced high speed propellers. Some results from the propeller lifting line and lifting surface aerodynamic analysis codes are compared with propeller force data, probe data and laser velocimeter data. In general, the code comparisons with data indicate good qualitative agreement. A rotating propeller force balance demonstrated good accuracy and reduced test time by 50 percent. Results from three propeller flow visualization techniques are shown which illustrate some of the physical phenomena occurring on these propellers.

  11. Advanced digital modulation: Communication techniques and monolithic GaAs technology

    NASA Technical Reports Server (NTRS)

    Wilson, S. G.; Oliver, J. D., Jr.; Kot, R. C.; Richards, C. R.

    1983-01-01

    Communications theory and practice are merged with state-of-the-art technology in IC fabrication, especially monolithic GaAs technology, to examine the general feasibility of a number of advanced technology digital transmission systems. Satellite-channel models with (1) superior throughput, perhaps 2 Gbps; (2) attractive weight and cost; and (3) high RF power and spectrum efficiency are discussed. Transmission techniques possessing reasonably simple architectures capable of monolithic fabrication at high speeds were surveyed. This included a review of amplitude/phase shift keying (APSK) techniques and the continuous-phase-modulation (CPM) methods, of which MSK represents the simplest case.

  12. Development of advanced electron holographic techniques and application to industrial materials and devices.

    PubMed

    Yamamoto, Kazuo; Hirayama, Tsukasa; Tanji, Takayoshi

    2013-06-01

    The development of a transmission electron microscope equipped with a field emission gun paved the way for electron holography to be put to practical use in various fields. In this paper, we review three advanced electron holography techniques: on-line real-time electron holography, three-dimensional (3D) tomographic holography and phase-shifting electron holography, which are becoming important techniques for materials science and device engineering. We also describe some applications of electron holography to the analysis of industrial materials and devices: GaAs compound semiconductors, solid oxide fuel cells and all-solid-state lithium ion batteries.

  13. Combined preputial advancement and phallopexy as a revision technique for treating paraphimosis in a dog.

    PubMed

    Wasik, S M; Wallace, A M

    2014-11-01

    A 7-year-old neutered male Jack Russell terrier-cross was presented for signs of recurrent paraphimosis, despite previous surgical enlargement of the preputial ostium. Revision surgery was performed using a combination of preputial advancement and phallopexy, which resulted in complete and permanent coverage of the glans penis by the prepuce, and at 1 year postoperatively, no recurrence of paraphimosis had been observed. The combined techniques allow preservation of the normal penile anatomy, are relatively simple to perform and provide a cosmetic result. We recommend this combination for the treatment of paraphimosis in the dog, particularly when other techniques have failed.

  14. [Principles and advanced techniques for better internetpresentations in obstetrics and gynecology].

    PubMed

    Seufert, R; Molitor, N; Pollow, K; Woernle, F; Hawighorst-Knapstein, S

    2001-08-01

    Internet presentations are common tools for better medical communication and better scientific work. Meanwhile a great number of gynecological and obstetrical institutions present data via the world wide web within a wide range of quality and performance. Specific HTML editors offer quick and easy presentations, but only advanced internet techniques enable interesting multimedia presentations. N-tier applications are the future standard and we must integrate them in general informatical systems. New Concepts, actual tools and general problems will be discussed and new principles similar to actual E commerce techniques are able to solve our special medical demands.

  15. Noncompaction cardiomyopathy: The role of advanced multimodality imaging techniques in diagnosis and assessment.

    PubMed

    Chebrolu, Lakshmi H; Mehta, Anjlee M; Nanda, Navin C

    2017-02-01

    Noncompaction cardiomyopathy (NCCM) is a unique cardiomyopathy with a diverse array of genotypic and phenotypic manifestations. Its hallmark morphology consists of a bilayered myocardium with a compact epicardial layer and prominent trabeculations that comprise the noncompacted endocardial layer. The controversial diagnostic criteria for NCCM have been frequently discussed in the literature. This review touches on those diagnostic criteria, delves further into the evolving use of advanced imaging techniques within the major imaging modalities (echocardiography, computed tomography, and cardiac magnetic resonance imaging), and proposes an alternative algorithm incorporating these techniques for aiding with the diagnosis of NCCM.

  16. The investigation of advanced remote sensing techniques for the measurement of aerosol characteristics

    NASA Technical Reports Server (NTRS)

    Deepak, A.; Becher, J.

    1979-01-01

    Advanced remote sensing techniques and inversion methods for the measurement of characteristics of aerosol and gaseous species in the atmosphere were investigated. Of particular interest were the physical and chemical properties of aerosols, such as their size distribution, number concentration, and complex refractive index, and the vertical distribution of these properties on a local as well as global scale. Remote sensing techniques for monitoring of tropospheric aerosols were developed as well as satellite monitoring of upper tropospheric and stratospheric aerosols. Computer programs were developed for solving multiple scattering and radiative transfer problems, as well as inversion/retrieval problems. A necessary aspect of these efforts was to develop models of aerosol properties.

  17. An example of requirements for Advanced Subsonic Civil Transport (ASCT) flight control system using structured techniques

    NASA Technical Reports Server (NTRS)

    Mclees, Robert E.; Cohen, Gerald C.

    1991-01-01

    The requirements are presented for an Advanced Subsonic Civil Transport (ASCT) flight control system generated using structured techniques. The requirements definition starts from initially performing a mission analysis to identify the high level control system requirements and functions necessary to satisfy the mission flight. The result of the study is an example set of control system requirements partially represented using a derivative of Yourdon's structured techniques. Also provided is a research focus for studying structured design methodologies and in particular design-for-validation philosophies.

  18. Reproducibility of a non-invasive ultrasonic technique of tendon force measurement, determined in vitro in equine superficial digital flexor tendons.

    PubMed

    Crevier-Denoix, Nathalie; Ravary-Plumioën, Bérangère; Evrard, Delphine; Pourcelot, Philippe

    2009-09-18

    A non-invasive ultrasonic (US) technique of tendon force measurement has been recently developed. It is based on the relationship demonstrated between the speed of sound (SOS) in a tendon and the traction force applied to it. The objectives of the present study were to evaluate the variability of this non-linear relationship among 7 equine superficial digital flexor (SDF) tendons, and the reproducibility of SOS measurements in these tendons over successive loading cycles and tests. Seven SDF tendons were equipped with an US probe (1MHz), secured in contact with the skin overlying the tendon metacarpal part. The tendons were submitted to a traction test consisting in 5 cycles of loading/unloading between 50 and 4050N. Four tendons out of the 7 were submitted to 5 additional cycles up to 5550N. The SOS-tendon force relationships appeared similar in shape, although large differences in SOS levels were observed among the tendons. Reproducibility between cycles was evaluated from the root mean square of the standard deviations (RMS-SD) of SOS values observed every 100N, and of force values every 2m/s. Reproducibility of SOS measurements revealed high between successive cycles: above 500N the RMS-SD was less than 2% of the corresponding traction force. Reproducibility between tests was lower, partly due to the experimental set-up; above 500N the difference between the two tests stayed nevertheless below 15% of the corresponding mean traction force. The reproducibility of the US technique here demonstrated in vitro has now to be confirmed in vivo.

  19. Study of advanced techniques for determining the long term performance of components

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The application of existing and new technology to the problem of determining the long-term performance capability of liquid rocket propulsion feed systems is discussed. The long term performance of metal to metal valve seats in a liquid propellant fuel system is stressed. The approaches taken in conducting the analysis are: (1) advancing the technology of characterizing components through the development of new or more sensitive techniques and (2) improving the understanding of the physical of degradation.

  20. ADVANCING THE FUNDAMENTAL UNDERSTANDING AND SCALE-UP OF TRISO FUEL COATERS VIA ADVANCED MEASUREMENT AND COMPUTATIONAL TECHNIQUES

    SciTech Connect

    Biswas, Pratim; Al-Dahhan, Muthanna

    2012-11-01

    to advance the fundamental understanding of the hydrodynamics by systematically investigating the effect of design and operating variables, to evaluate the reported dimensionless groups as scaling factors, and to establish a reliable scale-up methodology for the TRISO fuel particle spouted bed coaters based on hydrodynamic similarity via advanced measurement and computational techniques. An additional objective is to develop an on-line non-invasive measurement technique based on gamma ray densitometry (i.e. Nuclear Gauge Densitometry) that can be installed and used for coater process monitoring to ensure proper performance and operation and to facilitate the developed scale-up methodology. To achieve the objectives set for the project, the work will use optical probes and gamma ray computed tomography (CT) (for the measurements of solids/voidage holdup cross-sectional distribution and radial profiles along the bed height, spouted diameter, and fountain height) and radioactive particle tracking (RPT) (for the measurements of the 3D solids flow field, velocity, turbulent parameters, circulation time, solids lagrangian trajectories, and many other of spouted bed related hydrodynamic parameters). In addition, gas dynamic measurement techniques and pressure transducers will be utilized to complement the obtained information. The measurements obtained by these techniques will be used as benchmark data to evaluate and validate the computational fluid dynamic (CFD) models (two fluid model or discrete particle model) and their closures. The validated CFD models and closures will be used to facilitate the developed methodology for scale-up, design and hydrodynamic similarity. Successful execution of this work and the proposed tasks will advance the fundamental understanding of the coater flow field and quantify it for proper and safe design, scale-up, and performance. Such achievements will overcome the barriers to AGR applications and will help assure that the US maintains

  1. Integrating Organic Matter Structure with Ecosystem Function using Advanced Analytical Chemistry Techniques

    NASA Astrophysics Data System (ADS)

    Boot, C. M.

    2012-12-01

    Microorganisms are the primary transformers of organic matter in terrestrial and aquatic ecosystems. The structure of organic matter controls its bioavailability and researchers have long sought to link the chemical characteristics of the organic matter pool to its lability. To date this effort has been primarily attempted using low resolution descriptive characteristics (e.g. organic matter content, carbon to nitrogen ratio, aromaticity, etc .). However, recent progress in linking these two important ecosystem components has been advanced using advanced high resolution tools (e.g. nuclear magnetic resonance (NMR) spectroscopy, and mass spectroscopy (MS)-based techniques). A series of experiments will be presented that highlight the application of high resolution techniques in a variety of terrestrial and aquatic ecosystems with the focus on how these data explicitly provide the foundation for integrating organic matter structure into our concept of ecosystem function. The talk will highlight results from a series of experiments including: an MS-based metabolomics and fluorescence excitation emission matrix approach evaluating seasonal and vegetation based changes in dissolved organic matter (DOM) composition from arctic soils; Fourier transform ion cyclotron resonance (FTICR) MS and MS metabolomics analysis of DOM from three lakes in an alpine watershed; and the transformation of 13C labeled glucose track with NMR during a rewetting experiment from Colorado grassland soils. These data will be synthesized to illustrate how the application of advanced analytical techniques provides novel insight into our understanding of organic matter processing in a wide range of ecosystems.

  2. Potential of advanced MR imaging techniques in the differential diagnosis of parkinsonism.

    PubMed

    Hotter, Anna; Esterhammer, Regina; Schocke, Michael F H; Seppi, Klaus

    2009-01-01

    The clinical differentiation of parkinsonian syndromes remains challenging not only for neurologists but also for movement disorder specialists. Conventional magnetic resonance imaging (cMRI) with the visual assessment of T2- and T1-weighted imaging as well as different advanced MRI techniques offer objective measures, which may be a useful tool in the diagnostic work-up of Parkinson's disease and atypical parkinsonian disorders (APDs). In clinical practice, cMRI is a well-established method for the exclusion of symptomatic parkinsonism due to other pathologies. Over the past two decades, abnormalities in the basal ganglia and infratentorial structures have been shown especially in APDs not only by cMRI but also by different advanced MRI techniques, including methods to assess regional cerebral atrophy quantitatively such as magnetic resonance volumetry, proton magnetic resonance spectroscopy, diffusion-weighted imaging, and magnetization transfer imaging. This article aims to review recent research findings on the role of advanced MRI techniques in the differential diagnosis of neurodegenerative parkinsonian disorders.

  3. Advanced in situ spectroscopic techniques and their applications in environmental biogeochemistry: introduction to the special section.

    PubMed

    Lombi, Enzo; Hettiarachchi, Ganga M; Scheckel, Kirk G

    2011-01-01

    Understanding the molecular-scale complexities and interplay of chemical and biological processes of contaminants at solid, liquid, and gas interfaces is a fundamental and crucial element to enhance our understanding of anthropogenic environmental impacts. The ability to describe the complexity of environmental biogeochemical reaction mechanisms relies on our analytical ability through the application and developmemnt of advanced spectroscopic techniques. Accompanying this introductory article are nine papers that either review advanced in situ spectroscopic methods or present original research utilizing these techniques. This collection of articles summarizes the challenges facing environmental biogeochemistry, highlights the recent advances and scientific gaps, and provides an outlook into future research that may benefit from the use of in situ spectroscopic approaches. The use of synchrotron-based techniques and other methods are discussed in detail, as is the importance to integrate multiple analytical approaches to confirm results of complementary procedures or to fill data gaps. We also argue that future direction in research will be driven, in addition to recent analytical developments, by emerging factors such as the need for risk assessment of new materials (i.e., nanotechnologies) and the realization that biogeochemical processes need to be investigated in situ under environmentally relevant conditions.

  4. POC-scale testing of an advanced fine coal dewatering equipment/technique

    SciTech Connect

    Groppo, J.G.; Parekh, B.K.; Rawls, P.

    1995-11-01

    Froth flotation technique is an effective and efficient process for recovering of ultra-fine (minus 74 {mu}m) clean coal. Economical dewatering of an ultra-fine clean coal product to a 20 percent level moisture will be an important step in successful implementation of the advanced cleaning processes. This project is a step in the Department of Energy`s program to show that ultra-clean coal could be effectively dewatered to 20 percent or lower moisture using either conventional or advanced dewatering techniques. As the contract title suggests, the main focus of the program is on proof-of-concept testing of a dewatering technique for a fine clean coal product. The coal industry is reluctant to use the advanced fine coal recovery technology due to the non-availability of an economical dewatering process. in fact, in a recent survey conducted by U.S. DOE and Battelle, dewatering of fine clean coal was identified as the number one priority for the coal industry. This project will attempt to demonstrate an efficient and economic fine clean coal slurry dewatering process.

  5. Full matrix capture and the total focusing imaging algorithm using laser induced ultrasonic phased arrays

    NASA Astrophysics Data System (ADS)

    Stratoudaki, Theodosia; Clark, Matt; Wilcox, Paul D.

    2017-02-01

    Laser ultrasonics is a technique where lasers are used for the generation and detection of ultrasound instead of conventional piezoelectric transducers. The technique is broadband, non-contact, and couplant free, suitable for large stand-off distances, inspection of components of complex geometries and hazardous environments. In this paper, array imaging is presented by obtaining the full matrix of all possible laser generation, laser detection combinations in the array (Full Matrix Capture), at the nondestructive, thermoelastic regime. An advanced imaging technique developed for conventional ultrasonic transducers, the Total Focusing Method (TFM), is adapted for laser ultrasonics and then applied to the captured data, focusing at each point of the reconstruction area. In this way, the beamforming and steering of the ultrasound is done during the post processing. A 1-D laser induced ultrasonic phased array is synthesized with significantly improved spatial resolution and defect detectability. In this study, shear waves are used for the imaging, since they are more efficiently produced than longitudinal waves in the nondestructive, thermoelastic regime. Experimental results are presented from nondestructive, laser ultrasonic inspection of aluminum samples with side drilled holes and slots at depths varying between 5 and 20mm from the surface.

  6. Ultrasonic imaging of foreign inclusions and blood vessels through thick skull bones.

    PubMed

    Shapoori, Kiyanoosh; Sadler, Jeffrey; Ahmed, Zaki; Wydra, Adrian; Maeva, Elena; Malyarenko, Eugene; Maev, Roman

    2015-03-01

    We report a new progress in the development of a portable ultrasonic transcranial imaging system, which is expected to significantly improve the clinical utility of transcranial diagnostic ultrasound. When conventional ultrasonic phased array and Doppler techniques are applied through thick skull bones, the ultrasound field is attenuated, deflected, and defocused, leading to image distortion. To address these deficiencies, the ultrasonic transcranial imaging system implements two alternative ultrasonic methods. The first method improves detection of small foreign objects, such as bone fragments, pieces of shrapnel, or bullets, lodged in the brain tissue. Using adaptive beamforming, the method compensates for phase aberration induced by the skull and refocuses the distorted ultrasonic field at the desired location. The second method visualizes the blood flow through intact human skull using ultrasonic speckle reflections from the blood cells, platelets, or contrast agents. By analyzing these random temporal changes, it is possible to obtain 2D or 3D blood flow images, despite the adverse influence of the skull. Both methods were implemented on an advanced open platform phased array controller driving linear and matrix array probes. They were tested on realistic skull bone and head phantoms with foreign inclusions and blood vessel models.

  7. Advanced Time-Resolved Fluorescence Microscopy Techniques for the Investigation of Peptide Self-Assembly

    NASA Astrophysics Data System (ADS)

    Anthony, Neil R.

    The ubiquitous cross beta sheet peptide motif is implicated in numerous neurodegenerative diseases while at the same time offers remarkable potential for constructing isomorphic high-performance bionanomaterials. Despite an emerging understanding of the complex folding landscape of cross beta structures in determining disease etiology and final structure, we lack knowledge of the critical initial stages of nucleation and growth. In this dissertation, I advance our understanding of these key stages in the cross-beta nucleation and growth pathways using cutting-edge microscopy techniques. In addition, I present a new combined time-resolved fluorescence analysis technique with the potential to advance our current understanding of subtle molecular level interactions that play a pivotal role in peptide self-assembly. Using the central nucleating core of Alzheimer's Amyloid-beta protein, Abeta(16 22), as a model system, utilizing electron, time-resolved, and non-linear microscopy, I capture the initial and transient nucleation stages of peptide assembly into the cross beta motif. In addition, I have characterized the nucleation pathway, from monomer to paracrystalline nanotubes in terms of morphology and fluorescence lifetime, corroborating the predicted desolvation process that occurs prior to cross-beta nucleation. Concurrently, I have identified unique heterogeneous cross beta domains contained within individual nanotube structures, which have potential bionanomaterials applications. Finally, I describe a combined fluorescence theory and analysis technique that dramatically increases the sensitivity of current time-resolved techniques. Together these studies demonstrate the potential for advanced microscopy techniques in the identification and characterization of the cross-beta folding pathway, which will further our understanding of both amyloidogenesis and bionanomaterials.

  8. Ultrasonic study of adhesive bond quality at a steel-to-rubber interface by using quadrature phase detection techniques

    NASA Technical Reports Server (NTRS)

    Smith, A. C.; Yang, H.

    1989-01-01

    The quadrature phase detection technique was used to simultaneously monitor the phase and amplitude of a toneburst signal normally reflected from an adhesively bonded steel-to-rubber interface. The measured phase was found to show a positive shift for all bonded samples with respect to the disbonded state - the phase shift being larger for samples with weaker bonds, as manifested by smaller values of applied tensile loads at failure. A model calculation, which incorporates the concept of interfacial strength into the usual problem of wave propagation in multilayered media, was used to deduce a bond-quality parameter from an experimentally measured phase shift. This bond-quality parameter was found to be correlated with the tensile strength of the adhesive bonds at failure loads.

  9. Nondestructive Evaluation of Adhesive Bonds via Ultrasonic Phase Measurements

    NASA Technical Reports Server (NTRS)

    Haldren, Harold A.; Perey, Daniel F.; Yost, William T.; Cramer, K. Elliott; Gupta, Mool C.

    2016-01-01

    The use of advanced composites utilizing adhesively bonded structures offers advantages in weight and cost for both the aerospace and automotive industries. Conventional nondestructive evaluation (NDE) has proved unable to reliably detect weak bonds or bond deterioration during service life conditions. A new nondestructive technique for quantitatively measuring adhesive bond strength is demonstrated. In this paper, an ultrasonic technique employing constant frequency pulsed phased-locked loop (CFPPLL) circuitry to monitor the phase response of a bonded structure from change in thermal stress is discussed. Theoretical research suggests that the thermal response of a bonded interface relates well with the quality of the adhesive bond. In particular, the effective stiffness of the adhesive-adherent interface may be extracted from the thermal phase response of the structure. The sensitivity of the CFPPLL instrument allows detection of bond pathologies that have been previously difficult-to-detect. Theoretical results with this ultrasonic technique on single epoxy lap joint (SLJ) specimens are presented and discussed. This technique has the potential to advance the use of adhesive bonds - and by association, advanced composite structures - by providing a reliable method to measure adhesive bond strength, thus permitting more complex, lightweight, and safe designs.

  10. Ultrasonic stress measurements in prestressing tendons

    NASA Astrophysics Data System (ADS)

    Washer, Glenn A.; Green, Robert E.

    2002-05-01

    The goal of this research was to examine ultrasonic stress measurement techniques for the condition assessment of prestressing tendons. Acoustoelastic measurements were made in prestressing rods and strands, and constants are reported that relate the change in ultrasonic velocity to the change in stress. The effects of dispersion in prestressing tendons, which act as circular wave guides for ultrasonic waves, were measured and evaluated. For this research, narrow-band, noncontact Electromagnetic Acoustic Transducers (EMATs) were designed to launch and receive ultrasonic waves propagating within the tendons.

  11. Unified Ultrasonic/Eddy-Current Data Acquisition

    NASA Technical Reports Server (NTRS)

    Chern, E. James; Butler, David W.

    1993-01-01

    Imaging station for detecting cracks and flaws in solid materials developed combining both ultrasonic C-scan and eddy-current imaging. Incorporation of both techniques into one system eliminates duplication of computers and of mechanical scanners; unifies acquisition, processing, and storage of data; reduces setup time for repetitious ultrasonic and eddy-current scans; and increases efficiency of system. Same mechanical scanner used to maneuver either ultrasonic or eddy-current probe over specimen and acquire point-by-point data. For ultrasonic scanning, probe linked to ultrasonic pulser/receiver circuit card, while, for eddy-current imaging, probe linked to impedance-analyzer circuit card. Both ultrasonic and eddy-current imaging subsystems share same desktop-computer controller, containing dedicated plug-in circuit boards for each.

  12. Ultrasonic fingerprinting by phased array transducer

    NASA Astrophysics Data System (ADS)

    Sednev, D.; Kataeva, O.; Abramets, V.; Pushenko, P.; Tverdokhlebova, T.

    2016-06-01

    Increasing quantity of spent nuclear fuel that must be under national and international control requires a novel approach to safeguard techniques and equipment. One of the proposed approaches is utilize intrinsic features of casks with spent fuel. In this article an application of a phased array ultrasonic method is considered. This study describes an experimental results on ultrasonic fingerprinting of austenitic steel seam weld.

  13. Applications of Advanced Nondestructive Measurement Techniques to Address Safety of Flight Issues on NASA Spacecraft

    NASA Technical Reports Server (NTRS)

    Prosser, Bill

    2016-01-01

    Advanced nondestructive measurement techniques are critical for ensuring the reliability and safety of NASA spacecraft. Techniques such as infrared thermography, THz imaging, X-ray computed tomography and backscatter X-ray are used to detect indications of damage in spacecraft components and structures. Additionally, sensor and measurement systems are integrated into spacecraft to provide structural health monitoring to detect damaging events that occur during flight such as debris impacts during launch and assent or from micrometeoroid and orbital debris, or excessive loading due to anomalous flight conditions. A number of examples will be provided of how these nondestructive measurement techniques have been applied to resolve safety critical inspection concerns for the Space Shuttle, International Space Station (ISS), and a variety of launch vehicles and unmanned spacecraft.

  14. Accelerated Testing Methodology in Constant Stress-Rate Testing for Advanced Structural Ceramics: A Preloading Technique

    NASA Technical Reports Server (NTRS)

    Choi, Sung R.; Gyekenyesi, John P.; Huebert, Dean; Bartlett, Allen; Choi, Han-Ho

    2001-01-01

    Preloading technique was used as a means of an accelerated testing methodology in constant stress-rate ('dynamic fatigue') testing for two different brittle materials. The theory developed previously for fatigue strength as a function of preload was further verified through extensive constant stress-rate testing for glass-ceramic and CRT glass in room temperature distilled water. The preloading technique was also used in this study to identify the prevailing failure mechanisms at elevated temperatures, particularly at lower test rate in which a series of mechanisms would be associated simultaneously with material failure, resulting in significant strength increase or decrease. Two different advanced ceramics including SiC whisker-reinforced composite silicon nitride and 96 wt% alumina were used at elevated temperatures. It was found that the preloading technique can be used as an additional tool to pinpoint the dominant failure mechanism that is associated with such a phenomenon of considerable strength increase or decrease.

  15. Accelerated Testing Methodology in Constant Stress-Rate Testing for Advanced Structural Ceramics: A Preloading Technique

    NASA Technical Reports Server (NTRS)

    Choi, Sung R.; Gyekenyesi, John P.; Huebert, Dean; Bartlett, Allen; Choi, Han-Ho

    2001-01-01

    Preloading technique was used as a means of an accelerated testing methodology in constant stress-rate (dynamic fatigue) testing for two different brittle materials. The theory developed previously for fatigue strength as a function of preload was further verified through extensive constant stress-rate testing for glass-ceramic and CRT glass in room temperature distilled water. The preloading technique was also used in this study to identify the prevailing failure mechanisms at elevated temperatures, particularly at lower test rates in which a series of mechanisms would be associated simultaneously with material failure, resulting in significant strength increase or decrease. Two different advanced ceramics including SiC whisker-reinforced composite silicon nitride and 96 wt% alumina were used at elevated temperatures. It was found that the preloading technique can be used as an additional tool to pinpoint the dominant failure mechanism that is associated with such a phenomenon of considerable strength increase or decrease.

  16. Nanoemulsion of orange oil with non ionic surfactant produced emulsion using ultrasonication technique: evaluating against food spoilage yeast

    NASA Astrophysics Data System (ADS)

    Sugumar, Saranya; Singh, Sanjay; Mukherjee, Amitava; Chandrasekaran, N.

    2016-01-01

    In recent years, food industries have shown great interest in developing nanoemulsion (NE) using essential oils (EOs) to prevent food spoilage caused by microorganisms. The hydrophobic properties of EOs have lead to reduced solubilization effect of food, which in turn, created a negative impact on the quality of food and its antimicrobial efficacy. Focusing this issue, we attempted a unique NE preparation using orange oil, Tween 80 (organic phase) and water (aqueous phase) by sonication technique. Based on thermodynamic stability studies, the effective diameter was reported to be in the size range from 20 to 30 nm. Saccharomyces cerevisiae was used in testing the anti-yeast effect. Their activity was studied in both growth medium and apple juice. The minimum inhibitory concentration of this NE was determined using broth dilution method. At 2 μl/ml, orange oil NE demonstrated inhibition of tested microorganisms. The kinetics of killing curve, have shown that the NE treated cells had lost its viability within 30 min of interaction. Also, SEM image revealed that the treated cells became distorted in comparison to their control cells. NE treated apple juice showed complete loss of viability even on dilution as compared to their controls.

  17. A look-up-table digital predistortion technique for high-voltage power amplifiers in ultrasonic applications.

    PubMed

    Gao, Zheng; Gui, Ping

    2012-07-01

    In this paper, we present a digital predistortion technique to improve the linearity and power efficiency of a high-voltage class-AB power amplifier (PA) for ultrasound transmitters. The system is composed of a digital-to-analog converter (DAC), an analog-to-digital converter (ADC), and a field-programmable gate array (FPGA) in which the digital predistortion (DPD) algorithm is implemented. The DPD algorithm updates the error, which is the difference between the ideal signal and the attenuated distorted output signal, in the look-up table (LUT) memory during each cycle of a sinusoidal signal using the least-mean-square (LMS) algorithm. On the next signal cycle, the error data are used to equalize the signal with negative harmonic components to cancel the amplifier's nonlinear response. The algorithm also includes a linear interpolation method applied to the windowed sinusoidal signals for the B-mode and Doppler modes. The measurement test bench uses an arbitrary function generator as the DAC to generate the input signal, an oscilloscope as the ADC to capture the output waveform, and software to implement the DPD algorithm. The measurement results show that the proposed system is able to reduce the second-order harmonic distortion (HD2) by 20 dB and the third-order harmonic distortion (HD3) by 14.5 dB, while at the same time improving the power efficiency by 18%.

  18. Quantitative ultrasonic guided wave testing of composites

    NASA Astrophysics Data System (ADS)

    Djordjevic, B. Boro

    2013-01-01

    The advanced composite materials mechanical loads are typically optimized in-plane and not in the thickness. Materials anisotropy represents challenges to conventional ultrasonic nondestructive testing methods such as ultrasonic C-scan mapping. A different ultrasonic testing approach is needed to develop ultrasonic tests that can directly characterize anisotropic mechanical properties of the composite material. Development of new guided wave laser ultrasonic sources and new receiving sensors configurations enable in-plane testing of advanced composites far beyond conventional ultrasonic capabilities. This emerging technology explores the capability of the inhomogeneous, anisotropic composite material to propagate ultrasonic guided waves over a range of distances and part configurations. Appropriate customizing of ultrasonic transduction process enables measurements of material properties and an estimate of damage conditions along in-plane sound propagation path. From guided wave acoustic response, one can develop a meaningful estimate of the material anisotropy such as modulus as well as detect and assess fatigue damage, thermal damage and sense mechanical defect conditions. The reported results show in-situ materials directional properties for unidirectional, isotropic, and woven composite plates.

  19. Importance of integrated results of different non-destructive techniques in order to evaluate defects in panel paintings: the contribution of infrared, optical and ultrasonic techniques

    NASA Astrophysics Data System (ADS)

    Sfarra, S.; Theodorakeas, P.; Ibarra-Castanedo, C.; Avdelidis, N. P.; Paoletti, A.; Paoletti, D.; Hrissagis, K.; Bendada, A.; Koui, M.; Maldague, X.

    2011-06-01

    The increasing deterioration of panel paintings can be due to physical processes that take place during exhibition or transit, or as a result of temperature and humidity fluctuations within a building, church or museum. In response to environmental alterations, a panel painting can expand or contract and a new equilibrium state is eventually reached. These adjustments though, are usually accompanied by a change in shape in order to accommodate to the new conditions. In this work, a holographic method for detecting detached regions and micro-cracks is described. Some of these defects are confirmed by Thermographic Signal Reconstruction (TSR) technique. In addition, Pulsed Phase Thermography (PPT) and Principal Component Thermography (PCT) allow to identify with greater contrast two artificial defects in Mylar which are crucial to understand the topic of interest: the discrimination between defect materials. Finally, traditional contact ultrasounds applications, are widely applied for the evaluation of the wood quality in several characterization procedures. Inspecting the specimen from the front side, the natural and artificial defects of the specimen are confirmed. Experimental results derived by the application of the integrated methods on an Italian panel painting reproduction, called The Angel specimen, are presented. The main advantages that these techniques can offer to the conservation and restoration of artworks are emphasized.

  20. Effects of short-term administration of verapamil on left ventricular relaxation and filling dynamics measured by a combined hemodynamic-ultrasonic technique in patients with hypertrophic cardiomyopathy.

    PubMed

    TenCate, F J; Serruys, P W; Mey, S; Roelandt, J

    1983-12-01

    The effects of short-term administration of verapamil on left ventricular isovolumetric relaxation and early and late diastolic filling dynamics were studied in 10 patients with hypertrophic cardiomyopathy by a combined hemodynamic-ultrasonic technique. Left ventricular pressures (recorded with high-fidelity micromanometers) were determined simultaneously with M mode echocardiography. After 10 mg of verapamil was given intravenously (2 mg/min), left ventricular contractility and systolic pressure dropped significantly (p less than .05). Left ventricular dP/dt fell from 1947 +/- 544 to 1489 +/- 334 mm Hg/sec, maximal velocity of the contractile element at zero load fell from 50 +/- 17 to 42 +/- 15 1/sec, peak velocity contraction of the contractile element fell from 37 +/- 10 1/sec to 29 +/- 10 1/sec (p less than .05), and left ventricular systolic pressure fell from 149 +/- 30 to 127 +/- 22 mm Hg. Left ventricular negative dP/dt increased from 1770 +/- 479 to 1477 +/- 377 mm Hg/sec (p less than .05), and the time constant of isovolumetric pressure decay was prolonged from 48 +/- 9 to 64 +/- 15 msec (p less than .05). Left ventricular end-diastolic pressure rose from 21 +/- 7 to 23 +/- 6 mm Hg (p less than .05). The time constant of isovolumetric pressure decay was calculated in three different ways, but none of these measurements was influenced by verapamil. Time of isovolumetric relaxation, duration of rapid ventricular filling, and peak rate of left ventricular lengthening were not significantly influenced by verapamil and remained highly abnormal. In contrast, peak rate of left ventricular posterior wall thinning declined further after verapamil from 2.9 +/- 1.2 to 2.4 +/- 1.4 1/sec (p less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)

  1. An equivalent network representation of a clamped bimorph piezoelectric micromachined ultrasonic transducer with circular and annular electrodes using matrix manipulation techniques.

    PubMed

    Sammoura, Firas; Smyth, Katherine; Kim, Sang-Gook

    2013-09-01

    An electric circuit model for a clamped circular bimorph piezoelectric micromachined ultrasonic transducer (pMUT) was developed for the first time. The pMUT consisted of two piezoelectric layers sandwiched between three thin electrodes. The top and bottom electrodes were separated into central and annular electrodes by a small gap. While the middle electrode was grounded, the central and annular electrodes were biased with two independent voltage sources. The strain mismatch between the piezoelectric layers caused the plate to vibrate and transmit a pressure wave, whereas the received echo generated electric charges resulting from plate deformation. The clamped pMUT plate was separated into a circular and an annular plate, and the respective electromechanical transformation matrices were derived. The force and velocity vectors were properly selected using Hamilton's principle and the necessary boundary conditions were invoked. The electromechanical transformation matrix for the clamped circular pMUT was deduced using simple matrix manipulation techniques. The pMUT performance under three biasing schemes was elaborated: 1) central electrode only, 2) central and annular electrodes with voltages of the same magnitude and polarity, and 3) central and annular electrodes with voltages of the same magnitude and opposite polarity. The circuit parameters of the pMUT were extracted for each biasing scheme, including the transformer ratio, the clamped electric impedance, and the open-circuit mechanical impedance. Each pMUT scheme was characterized under different acoustic loadings using the theoretically developed model, which was verified with finite element modeling (FEM) simulation. The electrode size was optimized to maximize the electromechanical transformer ratio. As such, the developed model could provide more insight into the design, optimization, and characterization of pMUTs and allow for performance comparison with their cMUT counterparts.

  2. Ultrasonic measurement models for imaging with phased arrays

    NASA Astrophysics Data System (ADS)

    Schmerr, Lester W., Jr.; Engle, Brady J.; Sedov, Alexander; Li, Xiongbing

    2014-02-01

    Ultrasonic imaging measurement models (IMMs) are developed that generate images of flaws by inversion of ultrasonic measurement models. These IMMs are generalizations of the synthetic aperture focusing technique (SAFT) and the total focusing method (TFM). A special case when the flaw is small is shown to generalize physical optics far field inverse scattering (POFFIS) images. The ultrasonic IMMs provide a rational basis for generating and understanding the ultrasonic images produced by delay-and-sum imaging methods.

  3. Ultrasonic Technique to Retrieve a Rotary Nickel-Titanium File Broken Beyond the Apex and a Stainless Steel File from the Root Canal of a Mandibular Molar: A Case Report

    PubMed Central

    Kapoor, Sonali; Patel, Mukesh

    2015-01-01

    During endodontic treatment, clinicians may face endodontic procedural mishaps such as broken instruments, which is a complex situation especially when the file breaks beyond the apex. This condition is associated with potential risk of contamination, which compromises the healing process. Management of a broken instrument beyond the apex is difficult and time consuming and requires creativity as well as clinical knowledge and skills. Several devices and techniques have been developed to retrieve the fractured instruments, but none are consistently successful. This case report describes a technique using modern ultrasonic tips for retrieval of broken instruments separated beyond the apex. PMID:26877743

  4. System engineering techniques for establishing balanced design and performance guidelines for the advanced telerobotic testbed

    NASA Technical Reports Server (NTRS)

    Zimmerman, W. F.; Matijevic, J. R.

    1987-01-01

    Novel system engineering techniques have been developed and applied to establishing structured design and performance objectives for the Telerobotics Testbed that reduce technical risk while still allowing the testbed to demonstrate an advancement in state-of-the-art robotic technologies. To estblish the appropriate tradeoff structure and balance of technology performance against technical risk, an analytical data base was developed which drew on: (1) automation/robot-technology availability projections, (2) typical or potential application mission task sets, (3) performance simulations, (4) project schedule constraints, and (5) project funding constraints. Design tradeoffs and configuration/performance iterations were conducted by comparing feasible technology/task set configurations against schedule/budget constraints as well as original program target technology objectives. The final system configuration, task set, and technology set reflected a balanced advancement in state-of-the-art robotic technologies, while meeting programmatic objectives and schedule/cost constraints.

  5. Mini-dental implant insertion with the auto-advance technique for ongoing applications.

    PubMed

    Balkin, B E; Steflik, D E; Naval, F

    2001-01-01

    The clinical and histological results of two cases demonstrating retrieved Sendax mini-dental implants in two different patients is the focus of this report. The mini-dental implants were inserted using the auto-advance technique and loaded immediately. The implants were retrieved at 4 months following insertion and at 5 months following insertion and were prepared and reviewed histologically. Clinically, the implants had no mobility, with no apparent exudate or bleeding upon probing, prior to removal. At the time explant procedures were performed, the mini-dental implants had provided immediate support for prostheses during the integration of traditional root-form endosteal implants. Upon explantation, the mini-dental implants were in a state of health and functioning in their intended purpose. Histologically, the bone appeared to be integrated to the surface of the implant at the light microscope level, and the bone appeared to be relatively mature and healthy in the areas observed, more so than one would expect in this amount of time from insertion of mini-dental implants with immediate loading. A discussion of the purposes and technique used for insertion and removal of these mini-dental implants is discussed. This is the first human histological report on the auto-advance technique with immediate loading of mini-dental implants, demonstrating feasibility in ongoing applications.

  6. State-of-the-art characterization techniques for advanced lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Lu, Jun; Wu, Tianpin; Amine, Khalil

    2017-03-01

    To meet future needs for industries from personal devices to automobiles, state-of-the-art rechargeable lithium-ion batteries will require both improved durability and lowered costs. To enhance battery performance and lifetime, understanding electrode degradation mechanisms is of critical importance. Various advanced in situ and operando characterization tools developed during the past few years have proven indispensable for optimizing battery materials, understanding cell degradation mechanisms, and ultimately improving the overall battery performance. Here we review recent progress in the development and application of advanced characterization techniques such as in situ transmission electron microscopy for high-performance lithium-ion batteries. Using three representative electrode systems—layered metal oxides, Li-rich layered oxides and Si-based or Sn-based alloys—we discuss how these tools help researchers understand the battery process and design better battery systems. We also summarize the application of the characterization techniques to lithium-sulfur and lithium-air batteries and highlight the importance of those techniques in the development of next-generation batteries.

  7. Advanced Molecular Diagnostic Techniques for Detection of Food-borne Pathogens; Current Applications and Future Challenges.

    PubMed

    Umesha, S; Manukumar, H M

    2016-01-08

    The elimination of disease-causing microbes from the food supply is a primary goal and this review deals with the overall techniques availavle for detection of food-borne pathogens. Now-a-days conventional methods are replaced by advanced methods like Biosensors, Nucleic Acid-based Tests (NAT) and different PCR based techniques used in molecular biology to identify specific pathogens. Bacillus cereus, Staphylococcus aureus, Proteus vulgaris, Escherichia coli, Campylobacter, Listeria monocytogenes, Salmonella spp, Aspergillus spp. Fusarium spp. Penicillium spp., and pathogens are detected in contaminated food items which cause always diseases in human in any one or the other way. Identification of food-borne pathogens in a short period of time is still a challenge to the scientific field in general and food technology in particular. The low level of food contamination by major pathogens requires specific sensitive detection platforms and the present area of hot research looking forward to new nanomolecular techniques for nanomaterials, make them suitable for the development of assays with high sensitivity, response time and portability. With the sound of these we attemet to highlight a comprehensive overview about food-borne pathogen detection by rapid, sensitive, accurate and cost affordable in situ analytical methods from conventional methods to recent molecular approaches for advanced food and microbiology research.

  8. Ultrasonic field profile evaluation in acoustically inhomogeneous anisotropic materials using 2D ray tracing model: Numerical and experimental comparison.

    PubMed

    Kolkoori, S R; Rahman, M-U; Chinta, P K; Ktreutzbruck, M; Rethmeier, M; Prager, J

    2013-02-01

    Ultrasound propagation in inhomogeneous anisotropic materials is difficult to examine because of the directional dependency of elastic properties. Simulation tools play an important role in developing advanced reliable ultrasonic non destructive testing techniques for the inspection of anisotropic materials particularly austenitic cladded materials, austenitic welds and dissimilar welds. In this contribution we present an adapted 2D ray tracing model for evaluating ultrasonic wave fields quantitatively in inhomogeneous anisotropic materials. Inhomogeneity in the anisotropic material is represented by discretizing into several homogeneous layers. According to ray tracing model, ultrasonic ray paths are traced during its energy propagation through various discretized layers of the material and at each interface the problem of reflection and transmission is solved. The presented algorithm evaluates the transducer excited ultrasonic fields accurately by taking into account the directivity of the transducer, divergence of the ray bundle, density of rays and phase relations as well as transmission coefficients. The ray tracing model is able to calculate the ultrasonic wave fields generated by a point source as well as a finite dimension transducer. The ray tracing model results are validated quantitatively with the results obtained from 2D Elastodynamic Finite Integration Technique (EFIT) on several configurations generally occurring in the ultrasonic non destructive testing of anisotropic materials. Finally, the quantitative comparison of ray tracing model results with experiments on 32mm thick austenitic weld material and 62mm thick austenitic cladded material is discussed.

  9. Advanced Intensity-Modulation Continuous-Wave Lidar Techniques for Column CO2 Measurements

    NASA Astrophysics Data System (ADS)

    Campbell, J. F.; Lin, B.; Nehrir, A. R.; Harrison, F. W.; Obland, M. D.; Ismail, S.; Meadows, B.; Browell, E. V.

    2014-12-01

    Global atmospheric carbon dioxide (CO2) measurements for the NASA Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) space mission are critical for improving our understanding of global CO2 sources and sinks. Advanced Intensity-Modulated Continuous-Wave (IM-CW) lidar techniques are investigated as a means of facilitating CO2 measurements from space to meet the ASCENDS measurement requirements. In recent numerical, laboratory and flight experiments we have successfully used the Binary Phase Shift Keying (BPSK) modulation technique to uniquely discriminate surface lidar returns from intermediate aerosol and cloud contamination. We demonstrate the utility of BPSK to eliminate sidelobes in the range profile as a means of making Integrated Path Differential Absorption (IPDA) column CO2 measurements in the presence of optically thin clouds, thereby eliminating the need to correct for sidelobe bias errors caused by the clouds. Furthermore, high accuracy and precision ranging to the surface as well as to the top of intermediate cloud layers, which is a requirement for the inversion of column CO2 number density measurements to column CO2 mixing ratios, has been demonstrated using new hyperfine interpolation techniques that takes advantage of the periodicity of the modulation waveforms. This approach works well for both BPSK and linear swept-frequency modulation techniques. The BPSK technique under investigation has excellent auto-correlation properties while possessing a finite bandwidth. A comparison of BPSK and linear swept-frequency is also discussed in this paper.

  10. Extrusion based rapid prototyping technique: an advanced platform for tissue engineering scaffold fabrication.

    PubMed

    Hoque, M Enamul; Chuan, Y Leng; Pashby, Ian

    2012-02-01

    Advances in scaffold design and fabrication technology have brought the tissue engineering field stepping into a new era. Conventional techniques used to develop scaffolds inherit limitations, such as lack of control over the pore morphology and architecture as well as reproducibility. Rapid prototyping (RP) technology, a layer-by-layer additive approach offers a unique opportunity to build complex 3D architectures overcoming those limitations that could ultimately be tailored to cater for patient-specific applications. Using RP methods, researchers have been able to customize scaffolds to mimic the biomechanical properties (in terms of structural integrity, strength, and microenvironment) of the organ or tissue to be repaired/replaced quite closely. This article provides intensive description on various extrusion based scaffold fabrication techniques and review their potential utility for TE applications. The extrusion-based technique extrudes the molten polymer as a thin filament through a nozzle onto a platform layer-by-layer and thus building 3D scaffold. The technique allows full control over pore architecture and dimension in the x- and y- planes. However, the pore height in z-direction is predetermined by the extruding nozzle diameter rather than the technique itself. This review attempts to assess the current state and future prospects of this technology.

  11. Advanced techniques and technology for efficient data storage, access, and transfer

    NASA Technical Reports Server (NTRS)

    Rice, Robert F.; Miller, Warner

    1991-01-01

    Advanced techniques for efficiently representing most forms of data are being implemented in practical hardware and software form through the joint efforts of three NASA centers. These techniques adapt to local statistical variations to continually provide near optimum code efficiency when representing data without error. Demonstrated in several earlier space applications, these techniques are the basis of initial NASA data compression standards specifications. Since the techniques clearly apply to most NASA science data, NASA invested in the development of both hardware and software implementations for general use. This investment includes high-speed single-chip very large scale integration (VLSI) coding and decoding modules as well as machine-transferrable software routines. The hardware chips were tested in the laboratory at data rates as high as 700 Mbits/s. A coding module's definition includes a predictive preprocessing stage and a powerful adaptive coding stage. The function of the preprocessor is to optimally process incoming data into a standard form data source that the second stage can handle.The built-in preprocessor of the VLSI coder chips is ideal for high-speed sampled data applications such as imaging and high-quality audio, but additionally, the second stage adaptive coder can be used separately with any source that can be externally preprocessed into the 'standard form'. This generic functionality assures that the applicability of these techniques and their recent high-speed implementations should be equally broad outside of NASA.

  12. Pressure and temperature dependence of the elasticity of pyrope-majorite [Py 60Mj 40 and Py 50Mj 50] garnets solid solution measured by ultrasonic interferometry technique

    NASA Astrophysics Data System (ADS)

    Gwanmesia, Gabriel D.; Wang, Liping; Triplett, Richard; Liebermann, Robert C.

    2009-05-01

    Compressional (P) and shear (S) wave velocities have been measured for two synthetic polycrystalline specimens of pyrope-majorite garnets [Py 60Mj 40 and Py 50Mj 50] by ultrasonic interferometry to 8 GPa and 1000 K, in a DIA-type cubic anvil high pressure apparatus (SAM-85) interfaced with synchrotron X-radiation and X-ray imaging. Elastic bulk ( KS) and shear ( G) moduli data obtained at the end of the cooling cycles were fitted to functions of Eulerian strain to third order yielding pressure derivatives of the elastic moduli (∂ KS/∂ P) T = 4.3 (3); (∂ G/∂ P) T = 1.5 (1) for Py 60Mj 40 garnet and (∂ KS/∂ P) T = 4.4 (1); (∂ G/∂ P) T = 1.3 (1) for Py 50Mj 40 garnet. Both (∂ KS/∂ P) T and (∂ G/∂ P) T are identical for the two garnet compositions and are also consistent with Brillouin scattering data for polycrystalline Py 50Mj 50. Moreover, the new pressure derivatives of the elastic moduli are equal within experimental uncertainties to those of end-member pyrope garnet from ultrasonic studies [Gwanmesia, G.D., Zhang. J, Darling, K., Kung, J., Li, B., Wang, L., Neuville, D., Liebermann, R.C., 2006. Elasticity of polycrystalline pyrope (Mg 3Al 2Si 3O 12) to 9 GPa and 1000 °C. Phys. Earth Planet. Inter. 155, 179-190] and from Brillouin spectroscopic studies [Sinogeikin, S.V., Bass, J.D., 2002a. Elasticity of majorite and majorite-pyrope solid solution to high pressure: implications for the transition zone. Geophys. Res. 9(2), 1017], thereby demonstrating that the pressure derivatives of the elastic moduli are independent of the physical acoustics technique employed and unaffected by substitution of Si for Mg and Al within the Py-Mj solid solution in the range (Py 100-Py 50) of the present measurements. Temperature dependence of the elastic obtained from linear regression of entire P- T- K and P- T- G data are (∂ KS/∂ T) P = -14.6 (4) MPa/K; (∂ G/∂ T) P = -9.4 (4) MPa/K for Py 60Mj 40 garnet, and (∂ KS/∂ T) P = -14.6 (4) MPa/K; (

  13. Improved ultrasonic standard reference blocks

    NASA Technical Reports Server (NTRS)

    Eitzen, D. G.; Sushinsky, G. F.; Chwirut, D. J.; Bechtoldt, C. J.; Ruff, A. W.

    1976-01-01

    A program to improve the quality, reproducibility and reliability of nondestructive testing through the development of improved ASTM-type ultrasonic reference standards is described. Reference blocks of aluminum, steel, and titanium alloys are to be considered. Equipment representing the state-of-the-art in laboratory and field ultrasonic equipment was obtained and evaluated. RF and spectral data on ten sets of ultrasonic reference blocks have been taken as part of a task to quantify the variability in response from nominally identical blocks. Techniques for residual stress, preferred orientation, and micro-structural measurements were refined and are applied to a reference block rejected by the manufacturer during fabrication in order to evaluate the effect of metallurgical condition on block response. New fabrication techniques for reference blocks are discussed and ASTM activities are summarized.

  14. Comparison of Ultrasonic Scalpel versus Conventional Techniques in Open Gastrectomy for Gastric Carcinoma Patients: A Systematic Review and Meta-Analysis

    PubMed Central

    Chen, Xiao-Long; Chen, Xin-Zu; Lu, Zheng-Hao; Wang, Li; Yang, Kun; Hu, Jian-Kun; Zhang, Bo; Chen, Zhi-Xin; Chen, Jia-Ping; Zhou, Zong-Guang

    2014-01-01

    Objectives To compare surgical efficacy and postoperative recovery of ultrasonic scalpel (USS) with conventional techniques for the resection of gastric carcinoma. Methods A systematic search of major medical databases (PubMed, Embase, CCRT and CNKI) was conducted. Both randomized and non-randomized controlled trials (RCTs and nRCTs) were considered eligible. Operation time (OT), intraoperative blood loss (BL) and postoperative complications (POC) rates as well as postoperative hospitalization days, number of dissected lymph nodes, abdominal drainage volume and time for recovery of gastrointestinal functions were synthesized and compared. Results Nineteen studies were included (7 RCTs and 12 nRCTs), in which 1930 patients were enrolled totally (946 in the USS group and 984 in the conventional group). Monopolar electrocautery and ligation were used as the conventional methods. Comparative meta-analysis showed perioperative outcomes were significantly improved using USS compared with conventional surgical instrumentation. OT was reduced from a weighted mean of 185.3 min in the conventional group to 151.0 min in the USS group (MD = −33.30, 95% CI [−41.75, −24.86], p<0.001) and intraoperative BL was decreased from a weighted mean of 217.9 ml in the conventional group to 111.6 ml in the USS group (MD = −113.42, 95% CI [−142.05, −84.79], p<0.001). Results from RCTs subgroup were consistent with those from nRCTs subgroup. The weighted cumulative risk of POC accounted for 8.9% (0%–25%) and 12.9% (5.5%–45%) in the USS and conventional groups, respectively. Pooled estimated results from nRCTs (OR = 0.54, 95% CI [0.27, 1.06], p = 0.07) and RCTs (RR = 0.75, 95% CI [0.44, 1.26], p = 0.27) showed no significant difference between the USS and control groups. Analysis of secondary outcomes showed the improvements of the USS group over control group regarding the number of dissected lymph nodes, postoperative hospitalization days, abdominal

  15. Techniques for measurement of the thermal expansion of advanced composite materials

    NASA Technical Reports Server (NTRS)

    Tompkins, Stephen S.

    1989-01-01

    Techniques available to measure small thermal displacements in flat laminates and structural tubular elements of advanced composite materials are described. Emphasis is placed on laser interferometry and the laser interferometric dilatometer system used at the National Aeronautics and Space Administration (NASA) Langley Research Center. Thermal expansion data are presented for graphite-fiber reinforced 6061 and 2024 aluminum laminates and for graphite fiber reinforced AZ91 C and QH21 A magnesium laminates before and after processing to minimize or eliminate thermal strain hysteresis. Data are also presented on the effects of reinforcement volume content on thermal expansion of silicon-carbide whisker and particulate reinforced aluminum.

  16. Advanced techniques in IR thermography as a tool for the pest management professional

    NASA Astrophysics Data System (ADS)

    Grossman, Jon L.

    2006-04-01

    Within the past five years, the Pest Management industry has become aware that IR thermography can aid in the detection of pest infestations and locate other conditions that are within the purview of the industry. This paper will review the applications that can be utilized by the pest management professional and discuss the advanced techniques that may be required in conjunction with thermal imaging to locate insect and other pest infestations, moisture within structures, the verification of data and the special challenges associated with the inspection process.

  17. Measuring the microbiome: perspectives on advances in DNA-based techniques for exploring microbial life

    PubMed Central

    Bunge, John; Gilbert, Jack A.; Moore, Jason H.

    2012-01-01

    This article reviews recent advances in ‘microbiome studies’: molecular, statistical and graphical techniques to explore and quantify how microbial organisms affect our environments and ourselves given recent increases in sequencing technology. Microbiome studies are moving beyond mere inventories of specific ecosystems to quantifications of community diversity and descriptions of their ecological function. We review the last 24 months of progress in this sort of research, and anticipate where the next 2 years will take us. We hope that bioinformaticians will find this a helpful springboard for new collaborations with microbiologists. PMID:22308073

  18. Reliable Welding of HSLA Steels by Square Wave Pulsing Using an Advanced Sensing (EDAP) Technique.

    DTIC Science & Technology

    1986-04-30

    situation is the result of welding on A710 steel . (A similar effect on welding on HY80 ?) The following is offered by Woods and Milner (Ref. 12): "The...AD-R69 762 RELIABLE MELDING OF HSLA STEELS BY SQUARE MAVE PULSING 1/2 USING AN ADV NCED.. (U) APPLIED FUSION TECHNOLOGIES INC FORT COLLINS CO C...6 p . 0 Report 0001 AZ AD-A 168 762 I "RELIABLE WELDING OF HSLA STEELS BY SQUARE WAVE PULSING USING AN ADVANCED SENSING (EDAP) TECHNIQUE- Preliminary

  19. Advancing IM-CW Lidar Modulation Techniques for ASCENDS CO2 Column Measurements from Space

    NASA Astrophysics Data System (ADS)

    Campbell, J. F.; Lin, B.; Nehrir, A. R.; Harrison, F. W.; Chen, S.; Obland, M. D.

    2013-12-01

    Global atmospheric carbon dioxide (CO2) measurements through the Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) decadal survey recommended space mission are critical for improving our understanding of CO2 sources and sinks. IM-CW (Intensity Modulated Continuous Wave) lidar techniques are investigated as a means of facilitating CO2 measurements from space to meet the ASCENDS science requirements. In previous laboratory and flight experiments we have successfully used linear swept frequency modulation to discriminate surface lidar returns from intermediate aerosol and cloud contamination. Furthermore, high accuracy and precision ranging to the surface as well as to the top of intermediate clouds, which is a requirement for the inversion of the CO2 column mixing ratio from the instrument optical depth measurements, has been demonstrated with the linear swept frequency modulation technique. We are concurrently investigating advanced techniques to help improve the auto-correlation properties of the transmitted waveform implemented through physical hardware to make cloud rejection more robust in special restricted scenarios. Several different modulation techniques are compared including orthogonal linear swept, orthogonal non-linear swept, time shifted PN, sine wave modulated PN, and sine wave pulsed PN. Different PN code techniques are presented that are appropriate for different types of lidar hardware, including our current ASCENDS IM-CW concept space hardware. These techniques have excellent auto-correlation properties without sidelobes while possessing a finite bandwidth (by way of a new cyclic digital filter), which will reduce bias error in the presence of multiple scatterers. Our analyses show that the studied modulation techniques can increase the accuracy of CO2 column measurements from space.

  20. Arthroscopically assisted Sauvé-Kapandji procedure: an advanced technique for distal radioulnar joint arthritis.

    PubMed

    Luchetti, Riccardo; Khanchandani, Prakash; Da Rin, Ferdinando; Borelli, Pierpaolo P; Mathoulin, Christophe; Atzei, Andrea

    2008-12-01

    Osteoarthritis of distal radioulnar joint (DRUJ) leads to chronic wrist pain, weakness of grip strength, and limitation of motion, all of which affect the quality of life of the patient. Over the years, several procedures have been used for the treatment of this condition; however, this condition still remains a therapeutic challenge for the hand surgeons. Many procedures such as Darrach procedure, Bower procedure, Sauvé-Kapandji procedure, and ulnar head replacement have been used. Despite many advances in wrist arthroscopy, arthroscopy has not been used for the treatment of arthritis of the DRUJ. We describe a novel technique of arthroscopically assisted Sauvé-Kapandji procedure for the arthritis of the DRUJ. The advantages of this technique are its less invasive nature, preservation of the extensor retinaculum, more anatomical position of the DRUJ, faster rehabilitation, and a better cosmesis.

  1. The search for neuroimaging biomarkers of Alzheimer's disease with advanced MRI techniques.

    PubMed

    Li, Tie-Qiang; Wahlund, Lars-Olof

    2011-03-01

    The aim of this review is to examine the recent literature on using advanced magnetic resonance imaging (MRI) techniques for finding neuroimaging biomarkers that are sensitive to the detection of risks for Alzheimer's disease (AD). Since structural MRI techniques, such as brain structural volumetry and voxel-based morphometry (VBM), have been widely used for AD studies and extensively reviewed, we will only briefly touch on the topics of volumetry and morphometry. The focus of the current review is about the more recent developments in the search for AD neuroimaging biomarkers with functional MRI (fMRI), resting-state functional connectivity MRI (fcMRI), diffusion tensor imaging (DTI), arterial spin-labeling (ASL), and magnetic resonance spectroscopy (MRS).

  2. Benign Spine Lesions: Advances in Techniques for Minimally Invasive Percutaneous Treatment.

    PubMed

    Tomasian, A; Wallace, A N; Jennings, J W

    2017-02-09

    Minimally invasive percutaneous imaging-guided techniques have been shown to be safe and effective for the treatment of benign tumors of the spine. Techniques available include a variety of tumor ablation technologies, including radiofrequency ablation, cryoablation, microwave ablation, alcohol ablation, and laser photocoagulation. Vertebral augmentation may be performed after ablation as part of the same procedure for fracture stabilization or prevention. Typically, the treatment goal in benign spine lesions is definitive cure. Painful benign spine lesions commonly encountered in daily practice include osteoid osteoma, osteoblastoma, vertebral hemangioma, aneurysmal bone cyst, Paget disease, and subacute/chronic Schmorl node. This review discusses the most recent advancement and use of minimally invasive percutaneous therapeutic options for the management of benign spine lesions.

  3. Piezocomposites improve ultrasonic testing

    SciTech Connect

    Meyer, P.A.

    1997-02-01

    Ultrasonic testing is a nondestructive technique in which beams of high-frequency sound waves are introduced into materials for the detection of surface and subsurface flaws. Ultrasound probes--the devices that generate and receive acoustic energy--have historically been made of lead zirconate titanate (PZT) and similar piezoelectric ceramics. these materials have the capability to convert an electrical signal into acoustic energy (sound waves) to be transmitted into a part. The piezoelectric ceramic then converts the returning echoes into an electrical signal, which is evaluated by an electronic instrument similar to an oscilloscope. Although conventional transducers based on piezoelectric ceramics provide adequate performance, newly undeveloped piezocomposite transducers enable ultrasonic nondestructive testing devices to detect flaws with greater sensitivity than possible before. These are mixtures of conventional piezoelectric ceramics and polymers such as epoxy, polyurethane, and silicone rubber. A typical piezocomposite consists of an array of ceramic rods in a polymer matrix. This article explains the basics of ultrasonic testing, describes the advantages of the composite detector material, and shows how it is applied to detect flaws.

  4. Ultrasonic propulsion of kidney stones

    PubMed Central

    May, Philip C.; Bailey, Michael R.; Harper, Jonathan D.

    2016-01-01

    Purpose of review Ultrasonic propulsion is a novel technique that uses short bursts of focused ultrasonic pulses to reposition stones transcutaneously within the renal collecting system and ureter. The purpose of this review is to discuss the initial testing of effectiveness and safety, directions for refinement of technique and technology, and opinions on clinical application. Recent findings Preclinical studies with a range of probes, interfaces, and outputs have demonstrated feasibility and consistent safety of ultrasonic propulsion with room for increased outputs and refinement toward specific applications. Ultrasonic propulsion was used painlessly and without adverse events to reposition stones in 14 of 15 human study participants without restrictions on patient size, stone size, or stone location. The initial feasibility study showed applicability in a range of clinically relevant situations, including facilitating passage of residual fragments following ureteroscopy or shock wave lithotripsy, moving a large stone at the UPJ with relief of pain, and differentiating large stones from a collection of small fragments. Summary Ultrasonic propulsion shows promise as an office-based system for transcutaneously repositioning kidney stones. Potential applications include facilitating expulsion of residual fragments following ureteroscopy or shock wave lithotripsy, repositioning stones prior to treatment, and repositioning obstructing UPJ stones into the kidney to alleviate acute renal colic. PMID:26845428

  5. Recent Advances and New Techniques in Visualization of Ultra-short Relativistic Electron Bunches

    SciTech Connect

    Xiang, Dao; /SLAC

    2012-06-05

    Ultrashort electron bunches with rms length of {approx} 1 femtosecond (fs) can be used to generate ultrashort x-ray pulses in FELs that may open up many new regimes in ultrafast sciences. It is also envisioned that ultrashort electron bunches may excite {approx}TeV/m wake fields for plasma wake field acceleration and high field physics studies. Recent success of using 20 pC electron beam to drive an x-ray FEL at LCLS has stimulated world-wide interests in using low charge beam (1 {approx} 20 pC) to generate ultrashort x-ray pulses (0.1 fs {approx} 10 fs) in FELs. Accurate measurement of the length (preferably the temporal profile) of the ultrashort electron bunch is essential for understanding the physics associated with the bunch compression and transportation. However, the shorter and shorter electron bunch greatly challenges the present beam diagnostic methods. In this paper we review the recent advances in the measurement of ultra-short electron bunches. We will focus on several techniques and their variants that provide the state-of-the-art temporal resolution. Methods to further improve the resolution of these techniques and the promise to break the 1 fs time barrier is discussed. We review recent advances in the measurement of ultrashort relativistic electron bunches. We will focus on several techniques and their variants that are capable of breaking the femtosecond time barrier in measurements of ultrashort bunches. Techniques for measuring beam longitudinal phase space as well as the x-ray pulse shape in an x-ray FEL are also discussed.

  6. Individual Particle Analysis of Ambient PM 2.5 Using Advanced Electron Microscopy Techniques

    SciTech Connect

    Gerald J. Keeler; Masako Morishita

    2006-12-31

    The overall goal of this project was to demonstrate a combination of advanced electron microscopy techniques that can be effectively used to identify and characterize individual particles and their sources. Specific techniques to be used include high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM), STEM energy dispersive X-ray spectrometry (EDX), and energy-filtered TEM (EFTEM). A series of ambient PM{sub 2.5} samples were collected in communities in southwestern Detroit, MI (close to multiple combustion sources) and Steubenville, OH (close to several coal fired utility boilers). High-resolution TEM (HRTEM) -imaging showed a series of nano-metal particles including transition metals and elemental composition of individual particles in detail. Submicron and nano-particles with Al, Fe, Ti, Ca, U, V, Cr, Si, Ba, Mn, Ni, K and S were observed and characterized from the samples. Among the identified nano-particles, combinations of Al, Fe, Si, Ca and Ti nano-particles embedded in carbonaceous particles were observed most frequently. These particles showed very similar characteristics of ultrafine coal fly ash particles that were previously reported. By utilizing HAADF-STEM, STEM-EDX, and EF-TEM, this investigation was able to gain information on the size, morphology, structure, and elemental composition of individual nano-particles collected in Detroit and Steubenville. The results showed that the contributions of local combustion sources - including coal fired utilities - to ultrafine particle levels were significant. Although this combination of advanced electron microscopy techniques by itself can not identify source categories, these techniques can be utilized as complementary analytical tools that are capable of providing detailed information on individual particles.

  7. Ultrasonic transducer

    DOEpatents

    Taylor, Steven C.; Kraft, Nancy C.

    2007-03-13

    An ultrasonic transducer having an effective center frequency of about 42 MHz; a bandwidth of greater than 85% at 6 dB; a spherical focus of at least 0.5 inches in water; an F4 lens; a resolution sufficient to be able to detect and separate a 0.005 inch flat-bottomed hole at 0.005 inches below surface; and a beam size of approximately 0.006–0.008 inches measured off a 11/2 mm ball in water at the transducer's focal point.

  8. Ultrasonic pipe assessment

    DOEpatents

    Thomas, Graham H.; Morrow, Valerie L.; Levie, Harold; Kane, Ronald J.; Brown, Albert E.

    2003-12-23

    An ultrasonic pipe or other structure assessment system includes an ultrasonic transducer positioned proximate the pipe or other structure. A fluid connection between the ultrasonic transducer and the pipe or other structure is produced. The ultrasonic transducer is moved relative to the pipe or other structure.

  9. Where in the Cell Are You? Probing HIV-1 Host Interactions through Advanced Imaging Techniques

    PubMed Central

    Dirk, Brennan S.; Van Nynatten, Logan R.; Dikeakos, Jimmy D.

    2016-01-01

    Viruses must continuously evolve to hijack the host cell machinery in order to successfully replicate and orchestrate key interactions that support their persistence. The type-1 human immunodeficiency virus (HIV-1) is a prime example of viral persistence within the host, having plagued the human population for decades. In recent years, advances in cellular imaging and molecular biology have aided the elucidation of key steps mediating the HIV-1 lifecycle and viral pathogenesis. Super-resolution imaging techniques such as stimulated emission depletion (STED) and photoactivation and localization microscopy (PALM) have been instrumental in studying viral assembly and release through both cell–cell transmission and cell–free viral transmission. Moreover, powerful methods such as Forster resonance energy transfer (FRET) and bimolecular fluorescence complementation (BiFC) have shed light on the protein-protein interactions HIV-1 engages within the host to hijack the cellular machinery. Specific advancements in live cell imaging in combination with the use of multicolor viral particles have become indispensable to unravelling the dynamic nature of these virus-host interactions. In the current review, we outline novel imaging methods that have been used to study the HIV-1 lifecycle and highlight advancements in the cell culture models developed to enhance our understanding of the HIV-1 lifecycle. PMID:27775563

  10. Where in the Cell Are You? Probing HIV-1 Host Interactions through Advanced Imaging Techniques.

    PubMed

    Dirk, Brennan S; Van Nynatten, Logan R; Dikeakos, Jimmy D

    2016-10-19

    Viruses must continuously evolve to hijack the host cell machinery in order to successfully replicate and orchestrate key interactions that support their persistence. The type-1 human immunodeficiency virus (HIV-1) is a prime example of viral persistence within the host, having plagued the human population for decades. In recent years, advances in cellular imaging and molecular biology have aided the elucidation of key steps mediating the HIV-1 lifecycle and viral pathogenesis. Super-resolution imaging techniques such as stimulated emission depletion (STED) and photoactivation and localization microscopy (PALM) have been instrumental in studying viral assembly and release through both cell-cell transmission and cell-free viral transmission. Moreover, powerful methods such as Forster resonance energy transfer (FRET) and bimolecular fluorescence complementation (BiFC) have shed light on the protein-protein interactions HIV-1 engages within the host to hijack the cellular machinery. Specific advancements in live cell imaging in combination with the use of multicolor viral particles have become indispensable to unravelling the dynamic nature of these virus-host interactions. In the current review, we outline novel imaging methods that have been used to study the HIV-1 lifecycle and highlight advancements in the cell culture models developed to enhance our understanding of the HIV-1 lifecycle.

  11. Applications of Advanced, Waveform Based AE Techniques for Testing Composite Materials

    NASA Technical Reports Server (NTRS)

    Prosser, William H.

    1996-01-01

    Advanced, waveform based acoustic emission (AE) techniques have been previously used to evaluate damage progression in laboratory tests of composite coupons. In these tests, broad band, high fidelity acoustic sensors were used to detect signals which were then digitized and stored for analysis. Analysis techniques were based on plate mode wave propagation characteristics. This approach, more recently referred to as Modal AE, provides an enhanced capability to discriminate and eliminate noise signals from those generated by damage mechanisms. This technique also allows much more precise source location than conventional, threshold crossing arrival time determination techniques. To apply Modal AE concepts to the interpretation of AE on larger composite structures, the effects of wave propagation over larger distances and through structural complexities must be well characterized and understood. In this research, measurements were made of the attenuation of the extensional and flexural plate mode components of broad band simulated AE signals in large composite panels. As these materials have applications in a cryogenic environment, the effects of cryogenic insulation on the attenuation of plate mode AE signals were also documented.

  12. Biotechnology apprenticeship for secondary-level students: teaching advanced cell culture techniques for research.

    PubMed

    Lewis, Jennifer R; Kotur, Mark S; Butt, Omar; Kulcarni, Sumant; Riley, Alyssa A; Ferrell, Nick; Sullivan, Kathryn D; Ferrari, Mauro

    2002-01-01

    The purpose of this article is to discuss small-group apprenticeships (SGAs) as a method to instruct cell culture techniques to high school participants. The study aimed to teach cell culture practices and to introduce advanced imaging techniques to solve various biomedical engineering problems. Participants designed and completed experiments using both flow cytometry and laser scanning cytometry during the 1-month summer apprenticeship. In addition to effectively and efficiently teaching cell biology laboratory techniques, this course design provided an opportunity for research training, career exploration, and mentoring. Students participated in active research projects, working with a skilled interdisciplinary team of researchers in a large research institution with access to state-of-the-art instrumentation. The instructors, composed of graduate students, laboratory managers, and principal investigators, worked well together to present a real and worthwhile research experience. The students enjoyed learning cell culture techniques while contributing to active research projects. The institution's researchers were equally enthusiastic to instruct and serve as mentors. In this article, we clarify and illuminate the value of small-group laboratory apprenticeships to the institution and the students by presenting the results and experiences of seven middle and high school participants and their instructors.

  13. Advanced techniques for array processing. Final report, 1 Mar 89-30 Apr 91

    SciTech Connect

    Friedlander, B.

    1991-05-30

    Array processing technology is expected to be a key element in communication systems designed for the crowded and hostile environment of the future battlefield. While advanced array processing techniques have been under development for some time, their practical use has been very limited. This project addressed some of the issues which need to be resolved for a successful transition of these promising techniques from theory into practice. The main problem which was studied was that of finding the directions of multiple co-channel transmitters from measurements collected by an antenna array. Two key issues related to high-resolution direction finding were addressed: effects of system calibration errors, and effects of correlation between the received signals due to multipath propagation. A number of useful theoretical performance analysis results were derived, and computationally efficient direction estimation algorithms were developed. These results include: self-calibration techniques for antenna arrays, sensitivity analysis for high-resolution direction finding, extensions of the root-MUSIC algorithm to arbitrary arrays and to arrays with polarization diversity, and new techniques for direction finding in the presence of multipath based on array interpolation. (Author)

  14. Advanced condition monitoring techniques and plant life extension studies at EBR-2

    SciTech Connect

    Singer, R.M.; Gross, K.C. ); Perry, W.H.; King, R.W. )

    1991-01-01

    Numerous advanced techniques have been evaluated and tested at EBR-2 as part of a plant-life extension program for detection of degradation and other abnormalities in plant systems. Two techniques have been determined to be of considerable assistance in planning for the extended-life operation of EBR-2. The first, a computer-based pattern-recognition system (System State Analyzer or SSA) is used for surveillance of the primary system instrumentation, primary sodium pumps and plant heat balances. This surveillance has indicated that the SSA can detect instrumentation degradation and system performance degradation over varying time intervals and can be used to provide derived signal values to replace signals from failed sensors. The second technique, also a computer-based pattern-recognition system (Sequential Probability Ratio Test or SPRT) is used to validate signals and to detect incipient failures in sensors and components or systems. It is being used on the failed fuel detection system and is experimentally used on the primary coolant pumps. Both techniques are described and experience with their operation presented.

  15. Advancement of an Infra-Red Technique for Whole-Field Concentration Measurements in Fluidized Beds

    PubMed Central

    Medrano, Jose A.; de Nooijer, Niek C. A.; Gallucci, Fausto; van Sint Annaland, Martin

    2016-01-01

    For a better understanding and description of the mass transport phenomena in dense multiphase gas-solids systems such as fluidized bed reactors, detailed and quantitative experimental data on the concentration profiles is required, which demands advanced non-invasive concentration monitoring techniques with a high spatial and temporal resolution. A novel technique based on the selective detection of a gas component in a gas mixture using infra-red properties has been further developed. The first stage development was carried out using a very small sapphire reactor and CO2 as tracer gas. Although the measuring principle was demonstrated, the real application was hindered by the small reactor dimensions related to the high costs and difficult handling of large sapphire plates. In this study, a new system has been developed, that allows working at much larger scales and yet with higher resolution. In the new system, propane is used as tracer gas and quartz as reactor material. In this study, a thorough optimization and calibration of the technique is presented which is subsequently applied for whole-field measurements with high temporal resolution. The developed technique allows the use of a relatively inexpensive configuration for the measurement of detailed concentration fields and can be applied to a large variety of important chemical engineering topics. PMID:26927127

  16. Biotechnology Apprenticeship for Secondary-Level Students: Teaching Advanced Cell Culture Techniques for Research

    PubMed Central

    Lewis, Jennifer R.; Kotur, Mark S.; Butt, Omar; Kulcarni, Sumant; Riley, Alyssa A.; Ferrell, Nick; Sullivan, Kathryn D.; Ferrari, Mauro

    2002-01-01

    The purpose of this article is to discuss small-group apprenticeships (SGAs) as a method to instruct cell culture techniques to high school participants. The study aimed to teach cell culture practices and to introduce advanced imaging techniques to solve various biomedical engineering problems. Participants designed and completed experiments using both flow cytometry and laser scanning cytometry during the 1-month summer apprenticeship. In addition to effectively and efficiently teaching cell biology laboratory techniques, this course design provided an opportunity for research training, career exploration, and mentoring. Students participated in active research projects, working with a skilled interdisciplinary team of researchers in a large research institution with access to state-of-the-art instrumentation. The instructors, composed of graduate students, laboratory managers, and principal investigators, worked well together to present a real and worthwhile research experience. The students enjoyed learning cell culture techniques while contributing to active research projects. The institution's researchers were equally enthusiastic to instruct and serve as mentors. In this article, we clarify and illuminate the value of small-group laboratory apprenticeships to the institution and the students by presenting the results and experiences of seven middle and high school participants and their instructors. PMID:12587031

  17. Advanced grazing-incidence techniques for modern soft-matter materials analysis

    SciTech Connect

    Hexemer, Alexander; Müller-Buschbaum, Peter

    2015-01-01

    The complex nano-morphology of modern soft-matter materials is successfully probed with advanced grazing-incidence techniques. Based on grazing-incidence small- and wide-angle X-ray and neutron scattering (GISAXS, GIWAXS, GISANS and GIWANS), new possibilities arise which are discussed with selected examples. Due to instrumental progress, highly interesting possibilities for local structure analysis in this material class arise from the use of micro- and nanometer-sized X-ray beams in micro- or nanofocused GISAXS and GIWAXS experiments. The feasibility of very short data acquisition times down to milliseconds creates exciting possibilities forin situandin operandoGISAXS and GIWAXS studies. Tuning the energy of GISAXS and GIWAXS in the soft X-ray regime and in time-of flight GISANS allows the tailoring of contrast conditions and thereby the probing of more complex morphologies. In addition, recent progress in software packages, useful for data analysis for advanced grazing-incidence techniques, is discussed.

  18. Advanced grazing-incidence techniques for modern soft-matter materials analysis

    PubMed Central

    Hexemer, Alexander; Müller-Buschbaum, Peter

    2015-01-01

    The complex nano-morphology of modern soft-matter materials is successfully probed with advanced grazing-incidence techniques. Based on grazing-incidence small- and wide-angle X-ray and neutron scattering (GISAXS, GIWAXS, GISANS and GIWANS), new possibilities arise which are discussed with selected examples. Due to instrumental progress, highly interesting possibilities for local structure analysis in this material class arise from the use of micro- and nanometer-sized X-ray beams in micro- or nanofocused GISAXS and GIWAXS experiments. The feasibility of very short data acquisition times down to milliseconds creates exciting possibilities for in situ and in operando GISAXS and GIWAXS studies. Tuning the energy of GISAXS and GIWAXS in the soft X-ray regime and in time-of flight GISANS allows the tailoring of contrast conditions and thereby the probing of more complex morphologies. In addition, recent progress in software packages, useful for data analysis for advanced grazing-incidence techniques, is discussed. PMID:25610632

  19. Use of Advanced Magnetic Resonance Imaging Techniques in Neuromyelitis Optica Spectrum Disorder.

    PubMed

    Kremer, Stephane; Renard, Felix; Achard, Sophie; Lana-Peixoto, Marco A; Palace, Jacqueline; Asgari, Nasrin; Klawiter, Eric C; Tenembaum, Silvia N; Banwell, Brenda; Greenberg, Benjamin M; Bennett, Jeffrey L; Levy, Michael; Villoslada, Pablo; Saiz, Albert; Fujihara, Kazuo; Chan, Koon Ho; Schippling, Sven; Paul, Friedemann; Kim, Ho Jin; de Seze, Jerome; Wuerfel, Jens T; Cabre, Philippe; Marignier, Romain; Tedder, Thomas; van Pelt, Danielle; Broadley, Simon; Chitnis, Tanuja; Wingerchuk, Dean; Pandit, Lekha; Leite, Maria Isabel; Apiwattanakul, Metha; Kleiter, Ingo; Prayoonwiwat, Naraporn; Han, May; Hellwig, Kerstin; van Herle, Katja; John, Gareth; Hooper, D Craig; Nakashima, Ichiro; Sato, Douglas; Yeaman, Michael R; Waubant, Emmanuelle; Zamvil, Scott; Stüve, Olaf; Aktas, Orhan; Smith, Terry J; Jacob, Anu; O'Connor, Kevin

    2015-07-01

    Brain parenchymal lesions are frequently observed on conventional magnetic resonance imaging (MRI) scans of patients with neuromyelitis optica (NMO) spectrum disorder, but the specific morphological and temporal patterns distinguishing them unequivocally from lesions caused by other disorders have not been identified. This literature review summarizes the literature on advanced quantitative imaging measures reported for patients with NMO spectrum disorder, including proton MR spectroscopy, diffusion tensor imaging, magnetization transfer imaging, quantitative MR volumetry, and ultrahigh-field strength MRI. It was undertaken to consider the advanced MRI techniques used for patients with NMO by different specialists in the field. Although quantitative measures such as proton MR spectroscopy or magnetization transfer imaging have not reproducibly revealed diffuse brain injury, preliminary data from diffusion-weighted imaging and brain tissue volumetry indicate greater white matter than gray matter degradation. These findings could be confirmed by ultrahigh-field MRI. The use of nonconventional MRI techniques may further our understanding of the pathogenic processes in NMO spectrum disorders and may help us identify the distinct radiographic features corresponding to specific phenotypic manifestations of this disease.

  20. Advanced grazing-incidence techniques for modern soft-matter materials analysis.

    PubMed

    Hexemer, Alexander; Müller-Buschbaum, Peter

    2015-01-01

    The complex nano-morphology of modern soft-matter materials is successfully probed with advanced grazing-incidence techniques. Based on grazing-incidence small- and wide-angle X-ray and neutron scattering (GISAXS, GIWAXS, GISANS and GIWANS), new possibilities arise which are discussed with selected examples. Due to instrumental progress, highly interesting possibilities for local structure analysis in this material class arise from the use of micro- and nanometer-sized X-ray beams in micro- or nanofocused GISAXS and GIWAXS experiments. The feasibility of very short data acquisition times down to milliseconds creates exciting possibilities for in situ and in operando GISAXS and GIWAXS studies. Tuning the energy of GISAXS and GIWAXS in the soft X-ray regime and in time-of flight GISANS allows the tailoring of contrast conditions and thereby the probing of more complex morphologies. In addition, recent progress in software packages, useful for data analysis for advanced grazing-incidence techniques, is discussed.