WorldWideScience

Sample records for acoustic 4f imaging

  1. Acoustical Imaging

    CERN Document Server

    Litniewski, Jerzy; Kujawska, Tamara; 31st International Symposium on Acoustical Imaging

    2012-01-01

    The International Symposium on Acoustical Imaging is a unique forum for advanced research, covering new technologies, developments, methods and theories in all areas of acoustics. This interdisciplinary Symposium has been taking place continuously since 1968. In the course of the years the proceedings volumes in the Acoustical Imaging Series have become a reference for cutting-edge research in the field. In 2011 the 31st International Symposium on Acoustical Imaging was held in Warsaw, Poland, April 10-13. Offering both a broad perspective on the state-of-the-art as well as  in-depth research contributions by the specialists in the field, this Volume 31 in the Series contains an excellent collection of papers in six major categories: Biological and Medical Imaging Physics and Mathematics of Acoustical Imaging Acoustic Microscopy Transducers and Arrays Nondestructive Evaluation and Industrial Applications Underwater Imaging

  2. Acoustical Imaging

    CERN Document Server

    Akiyama, Iwaki

    2009-01-01

    The 29th International Symposium on Acoustical Imaging was held in Shonan Village, Kanagawa, Japan, April 15-18, 2007. This interdisciplinary Symposium has been taking place every two years since 1968 and forms a unique forum for advanced research, covering new technologies, developments, methods and theories in all areas of acoustics. In the course of the years the volumes in the Acoustical Imaging Series have developed and become well-known and appreciated reference works. Offering both a broad perspective on the state-of-the-art in the field as well as an in-depth look at its leading edge research, this Volume 29 in the Series contains again an excellent collection of seventy papers presented in nine major categories: Strain Imaging Biological and Medical Applications Acoustic Microscopy Non-Destructive Evaluation and Industrial Applications Components and Systems Geophysics and Underwater Imaging Physics and Mathematics Medical Image Analysis FDTD method and Other Numerical Simulations Audience Researcher...

  3. Acoustic imaging system

    Science.gov (United States)

    Smith, Richard W.

    1979-01-01

    An acoustic imaging system for displaying an object viewed by a moving array of transducers as the array is pivoted about a fixed point within a given plane. A plurality of transducers are fixedly positioned and equally spaced within a laterally extending array and operatively directed to transmit and receive acoustic signals along substantially parallel transmission paths. The transducers are sequentially activated along the array to transmit and receive acoustic signals according to a preestablished sequence. Means are provided for generating output voltages for each reception of an acoustic signal, corresponding to the coordinate position of the object viewed as the array is pivoted. Receptions from each of the transducers are presented on the same display at coordinates corresponding to the actual position of the object viewed to form a plane view of the object scanned.

  4. Performance of a C4F8O gas radiator ring imaging Cherenkov detector using multi-anode photomultiplier tubes

    International Nuclear Information System (INIS)

    Artuso, M.; Boulahouache, C.; Blusk, S.; Butt, J.; Dorjkhaidav, O.; Menaa, N.; Mountain, R.; Muramatsu, H.; Nandakumar, R.; Randrianarivony, K.; Sia, R.; Skwarnicki, T.; Stone, S.; Wang, J.C.; Zhang, K.

    2006-01-01

    We report on tests of a novel ring imaging Cherenkov (RICH) detection system consisting of a 3-m-long gaseous C 4 F 8 O radiator, a focusing mirror, and a photon detector array based on Hamamatsu multi-anode photomultiplier tubes. This system was developed to identify charged particles in the momentum range from 3 to 70GeV/c for the BTeV experiment

  5. MR imaging of acoustic neurinoma

    International Nuclear Information System (INIS)

    Miyamachi, Keikichi; Aida, Toshimitsu; Abe, Hiroshi; Nomura, Mikio; Saitou, Hisatoshi.

    1988-01-01

    Fifteen cases of acoustic neurinomas were studied by the use of a 0.15 T magnetic resonance (MR) imager. Three of the patients were male, and twelve were female. The patients' ages ranged from 23 to 67 years. The tumors were measured by means of MR images; the maximum was 37.5 mm across, and the minimum, 10 mm. The MR images of the acoustic neurinomas were hypointense on the T 1 -weighted images except in one case (isointense), while all cases were hyperintense on the T 2 -weighted images. MRI was much better than contrastenhanced CT for internal auditory canal (IAC) tumors (78 % versus 36 %), especially by means of coronal oblique image on T 2 -weighted images. In addition, MRI was more useful in demonstrating a VII - VIII neurocomplex on the non-affected side than was CT (57 % versus 10 %), but it did not demonstrate a VII - VIII neurocomplex on the affected side when a 0.15 T MR imager was used. It is very effective to separate the tumor from the tentorium cerebelli when it is necessary to differentiate an acoustic neurinoma from a meningioma at the cerebellopontine angle. A coronal or coronal oblique image offers information for use in separating the tentorium cerebelli. In small IAC tumors, the increased protein content of the cerebro-spinal fluid in an obstructed IAC and the bound-water effect in small collections of fluid may shorten the relaxation times of the trapped intracanalicular fluid, producing difficulty in the ability to diagnosis small tumors. To reveal cystic components, it was found to be effective to use Gd-DTPA or short-TR short-TE spin-echo images. (author)

  6. 30th International Acoustical Imaging Symposium

    CERN Document Server

    Jones, Joie; Lee, Hua

    2011-01-01

    The International Symposium on Acoustical Imaging is a unique forum for advanced research, covering new technologies, developments, methods and theories in all areas of acoustics. This interdisciplinary Symposium has been taking place every two years since 1968. In the course of the years the proceedings volumes in the Acoustical Imaging Series have become a reference for cutting-edge research in the field. In 2009 the 30th International Symposium on Acoustical Imaging was held in Monterey, CA, USA, March 1-4. Offering both a broad perspective on the state-of-the-art as well as  in-depth research contributions by the specialists in the field, this Volume 30 in the Series contains an excellent collection of forty three papers presented in five major categories: Biomedical Imaging Acoustic Microscopy Non-Destructive Evaluation Systems Analysis Signal Analysis and Image Processing Audience Researchers in medical imaging and biomedical instrumentation experts.

  7. Acoustic 3D imaging of dental structures

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, D.K. [Lawrence Livermore National Lab., CA (United States); Hume, W.R. [California Univ., Los Angeles, CA (United States); Douglass, G.D. [California Univ., San Francisco, CA (United States)

    1997-02-01

    Our goals for the first year of this three dimensional electodynamic imaging project was to determine how to combine flexible, individual addressable; preprocessing of array source signals; spectral extrapolation or received signals; acoustic tomography codes; and acoustic propagation modeling code. We investigated flexible, individually addressable acoustic array material to find the best match in power, sensitivity and cost and settled on PVDF sheet arrays and 3-1 composite material.

  8. Homotopy Based Reconstruction from Acoustic Images

    DEFF Research Database (Denmark)

    Sharma, Ojaswa

    of the inherent arrangement. The problem of reconstruction from arbitrary cross sections is a generic problem and is also shown to be solved here using the mathematical tool of continuous deformations. As part of a complete processing, segmentation using level set methods is explored for acoustic images and fast...... GPU (Graphics Processing Unit) based methods are suggested for a streaming computation on large volumes of data. Validation of results for acoustic images is not straightforward due to unavailability of ground truth. Accuracy figures for the suggested methods are provided using phantom object...

  9. Subwavelength image manipulation through oblique and herringbone layered acoustic systems

    International Nuclear Information System (INIS)

    Li, Chunhui; Jia, Han; Ke, Manzhu; Li, Yixiang; Liu, Zhengyou

    2014-01-01

    In this paper, an oblique and a herringbone layered acoustic structure are experimentally and theoretically demonstrated to manipulate acoustic subwavelength images. An imaging resolution of less than one tenth of a wavelength is achieved with both optimized systems, and lateral image shift has been realized by an oblique layered system. The thicknesses of both the oblique and the herringbone layered acoustic systems are largely reduced through utilizing the oblique or herringbone wave propagation path instead of the vertical wave propagation path in the rectangular layered planar acoustic system. With smaller size and subwavelength image manipulation, the acoustic systems are more favourable for practical application. (paper)

  10. 28th International Acoustical Imaging Symposium

    CERN Document Server

    André, Michael P; Andre, Michael; Arnold, Walter; Bamber, Jeff; Burov, Valentin; Chubachi, Noriyoshi; Erikson, Kenneth; Ermert, Helmut; Fink, Mathias; Gan, Woon S; Granz, Bernd; Greenleaf, James; Hu, Jiankai; Jones, Joie P; Khuri-Yakub, Pierre; Laugier, Pascal; Lee, Hua; Lees, Sidney; Levin, Vadim M; Maev, Roman; Masotti, Leonardo; Nowicki, Andrzej; O’Brien, William; Prasad, Manika; Rafter, Patrick; Rouseff, Daniel; Thijssen, Johan; Tittmann, Bernard; Tortoli, Piero; Steen, Anton; Waag, Robert; Wells, Peter; Acoustical Imaging

    2007-01-01

    The International Acoustical Imaging Symposium has been held continuously since 1968 as a unique forum for advanced research, promoting the sharing of technology, developments, methods and theory among all areas of acoustics. The interdisciplinary nature of the Symposium and the wide international participation are two of its main strengths. Scientists from around the world present their papers in an informal environment conducive to lively discussion and cross-fertilization. The fact that a loyal community of scientists has supported this Series since 1968 is evidence of its impact on the field. The Symposium Series continues to thrive in a busy calendar of scientific meetings without the infrastructure of a professional society. It does so because those who attend and those who rely on the Proceedings as a well-known reference work acknowledge its value. This Volume 28 of the Proceedings likewise contains an excellent collection of papers presented in six major categories, offering both a broad perspective ...

  11. High throughput imaging cytometer with acoustic focussing.

    Science.gov (United States)

    Zmijan, Robert; Jonnalagadda, Umesh S; Carugo, Dario; Kochi, Yu; Lemm, Elizabeth; Packham, Graham; Hill, Martyn; Glynne-Jones, Peter

    2015-10-31

    We demonstrate an imaging flow cytometer that uses acoustic levitation to assemble cells and other particles into a sheet structure. This technique enables a high resolution, low noise CMOS camera to capture images of thousands of cells with each frame. While ultrasonic focussing has previously been demonstrated for 1D cytometry systems, extending the technology to a planar, much higher throughput format and integrating imaging is non-trivial, and represents a significant jump forward in capability, leading to diagnostic possibilities not achievable with current systems. A galvo mirror is used to track the images of the moving cells permitting exposure times of 10 ms at frame rates of 50 fps with motion blur of only a few pixels. At 80 fps, we demonstrate a throughput of 208 000 beads per second. We investigate the factors affecting motion blur and throughput, and demonstrate the system with fluorescent beads, leukaemia cells and a chondrocyte cell line. Cells require more time to reach the acoustic focus than beads, resulting in lower throughputs; however a longer device would remove this constraint.

  12. Magnetic resonance imaging of acoustic neurinomas

    International Nuclear Information System (INIS)

    Umezu, Hiromichi; Seki, Yojiro; Aiba, Tadashi; Takemori, Setsuko

    1991-01-01

    A restrospective review was made on magnetic resonance imaging (MRI) scans, preoperative neuro-otological findings, and surgical results for hearing preservation in 20 consecutive patients with histologically verified acoustic neurinomas. The maximum diameter of the tumor, both in the cerebellopontine angle (CPA) and internal auditory canal (IAC), were measured by MRI scans to classify tumor size. The signal intensity of acoustic neurinoma was equal to or lower than that of the adjacent pons on T 1 -weighted images and higher on T 2 -weighted images. After the administration of Gd-DTPA, tumors were markedly enhanced, which appeared homogeneous for small tumors and heterogeneous for large ones. There was no relationship between the degree of preoperative hearing loss and tumor size in either the CPA or the IAC. The larger the tumor in the CPA, however, the more often did the response to a caloric test disappear or decrease greatly. In contrast, there was no apparent correlation between the caloric response and tumor size in the IAC. Twelve patients (60%) had serviceable hearing (pure tone average loss 50%) preoperatively: the average tumor size in this group was similar to that in patients with poor or no hearing. These 12 patients were considered to be candidates for hearing preservation at surgery: 5 (41.7%) retained serviceable hearing postoperatively. A mean tumor size in the CPA was 11.8 mm for patients with postoperative serviceable hearing and 21.3 mm for those without it. Moreover, hearing was preserved postoperatively in all 4 patients with tumor less than 5 mm in the IAC. Thus, hearing preservation after surgery seemed to be closely related to tumor size. This study confirmed the value of MRI, providing information for the evaluation of hearing-preservation surgery. (N.K.)

  13. Laser-induced acoustic imaging of underground objects

    Science.gov (United States)

    Li, Wen; DiMarzio, Charles A.; McKnight, Stephen W.; Sauermann, Gerhard O.; Miller, Eric L.

    1999-02-01

    This paper introduces a new demining technique based on the photo-acoustic interaction, together with results from photo- acoustic experiments. We have buried different types of targets (metal, rubber and plastic) in different media (sand, soil and water) and imaged them by measuring reflection of acoustic waves generated by irradiation with a CO2 laser. Research has been focused on the signal acquisition and signal processing. A deconvolution method using Wiener filters is utilized in data processing. Using a uniform spatial distribution of laser pulses at the ground's surface, we obtained 3D images of buried objects. The images give us a clear representation of the shapes of the underground objects. The quality of the images depends on the mismatch of acoustic impedance of the buried objects, the bandwidth and center frequency of the acoustic sensors and the selection of filter functions.

  14. Optimization of a Biometric System Based on Acoustic Images

    Directory of Open Access Journals (Sweden)

    Alberto Izquierdo Fuente

    2014-01-01

    Full Text Available On the basis of an acoustic biometric system that captures 16 acoustic images of a person for 4 frequencies and 4 positions, a study was carried out to improve the performance of the system. On a first stage, an analysis to determine which images provide more information to the system was carried out showing that a set of 12 images allows the system to obtain results that are equivalent to using all of the 16 images. Finally, optimization techniques were used to obtain the set of weights associated with each acoustic image that maximizes the performance of the biometric system. These results improve significantly the performance of the preliminary system, while reducing the time of acquisition and computational burden, since the number of acoustic images was reduced.

  15. Optimization of a Biometric System Based on Acoustic Images

    Science.gov (United States)

    Izquierdo Fuente, Alberto; Del Val Puente, Lara; Villacorta Calvo, Juan J.; Raboso Mateos, Mariano

    2014-01-01

    On the basis of an acoustic biometric system that captures 16 acoustic images of a person for 4 frequencies and 4 positions, a study was carried out to improve the performance of the system. On a first stage, an analysis to determine which images provide more information to the system was carried out showing that a set of 12 images allows the system to obtain results that are equivalent to using all of the 16 images. Finally, optimization techniques were used to obtain the set of weights associated with each acoustic image that maximizes the performance of the biometric system. These results improve significantly the performance of the preliminary system, while reducing the time of acquisition and computational burden, since the number of acoustic images was reduced. PMID:24616643

  16. Combination of acoustical radiosity and the image source method

    DEFF Research Database (Denmark)

    Koutsouris, Georgios I; Brunskog, Jonas; Jeong, Cheol-Ho

    2013-01-01

    A combined model for room acoustic predictions is developed, aiming to treat both diffuse and specular reflections in a unified way. Two established methods are incorporated: acoustical radiosity, accounting for the diffuse part, and the image source method, accounting for the specular part...

  17. Acoustic-noise-optimized diffusion-weighted imaging.

    Science.gov (United States)

    Ott, Martin; Blaimer, Martin; Grodzki, David M; Breuer, Felix A; Roesch, Julie; Dörfler, Arnd; Heismann, Björn; Jakob, Peter M

    2015-12-01

    This work was aimed at reducing acoustic noise in diffusion-weighted MR imaging (DWI) that might reach acoustic noise levels of over 100 dB(A) in clinical practice. A diffusion-weighted readout-segmented echo-planar imaging (EPI) sequence was optimized for acoustic noise by utilizing small readout segment widths to obtain low gradient slew rates and amplitudes instead of faster k-space coverage. In addition, all other gradients were optimized for low slew rates. Volunteer and patient imaging experiments were conducted to demonstrate the feasibility of the method. Acoustic noise measurements were performed and analyzed for four different DWI measurement protocols at 1.5T and 3T. An acoustic noise reduction of up to 20 dB(A) was achieved, which corresponds to a fourfold reduction in acoustic perception. The image quality was preserved at the level of a standard single-shot (ss)-EPI sequence, with a 27-54% increase in scan time. The diffusion-weighted imaging technique proposed in this study allowed a substantial reduction in the level of acoustic noise compared to standard single-shot diffusion-weighted EPI. This is expected to afford considerably more patient comfort, but a larger study would be necessary to fully characterize the subjective changes in patient experience.

  18. Near-field acoustic imaging based on Laplacian sparsity

    DEFF Research Database (Denmark)

    Fernandez Grande, Efren; Daudet, Laurent

    2016-01-01

    We present a sound source identification method for near-field acoustic imaging of extended sources. The methodology is based on a wave superposition method (or equivalent source method) that promotes solutions with sparse higher order spatial derivatives. Instead of promoting direct sparsity......, and the validity of the wave extrapolation used for the reconstruction is examined. It is shown that this methodology can overcome conventional limits of spatial sampling, and is therefore valid for wide-band acoustic imaging of extended sources....

  19. Magnetic resonance imaging in 38 cases of acoustic tumors

    Energy Technology Data Exchange (ETDEWEB)

    Uchino, Masafumi; Ohtsuka, Takashi; Seiki, Yoshikatsu; Matsumoto, Mikiro; Shibata, Iekado; Terao, Hideo [Toho Univ., Tokyo (Japan). School of Medicine; Kohno, Takeshi; Sanpei, Kenji; Mano, Isamu

    1989-08-01

    The value of magnetic resonance imaging (MRI) in the diagnosis of acoustic tumors was retrospectively assessed in 38 cases. A 0.15 Tesla permanent magnet and a 1.5 Tesla superconducting magnet were employed in 24 and 14 cases, respectively. Gadolinium diethlene triamine pentaacetic acid (Gd-DTPA), a paramagnetic contrast agent, was used in 10 cases. Acoustic tumors were identified in all cases. Small, medium, and large tumors were depicted with equal clarity by MRI and computed tomography (CT). However, tumor contour and extension, accompanying cysts, and brainstem displacement were more clarly visualized on MRI. The use of Gd-DTPA improved the quality of the MR images by markedly enhancing the acoustic tumors in all cases. In particular, detection of small acoustic tumors and intra- or paratumoral cysts was facilitated by the use of Gd-DTPA. The possibility of a correlation between acoustic tumor histology and MRI features was studied by calculation of the contrast to noise (C/N) ratio in 10 cases of acoustic tumor and 7 cases of meningioma. No definite correlation was demonstrated, but there appeared to be some difference in the C/N ratio between acoustic tumors and meningiomas. In three volunteers, MRI demonstrated intracanalicular nerves, separately. Because of its higher resolution, MRI can be expected to replace CT and air CT in the diagnosis of acoustic tumors. (author).

  20. Vibro-acoustic Imaging at the Breazeale Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Smith, James Arthur [Idaho National Lab. (INL), Idaho Falls, ID (United States); Jewell, James Keith [Idaho National Lab. (INL), Idaho Falls, ID (United States); Lee, James Edwin [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-09-01

    The INL is developing Vibro-acoustic imaging technology to characterize microstructure in fuels and materials in spent fuel pools and within reactor vessels. A vibro-acoustic development laboratory has been established at the INL. The progress in developing the vibro-acoustic technology at the INL is the focus of this report. A successful technology demonstration was performed in a working TRIGA research reactor. Vibro-acoustic imaging was performed in the reactor pool of the Breazeale reactor in late September of 2015. A confocal transducer driven at a nominal 3 MHz was used to collect the 60 kHz differential beat frequency induced in a spent TRIGA fuel rod and empty gamma tube located in the main reactor water pool. Data was collected and analyzed with the INLDAS data acquisition software using a short time Fourier transform.

  1. Synthetic Aperture Acoustic Imaging for Roadside Detection of Solid Objects

    Science.gov (United States)

    2014-11-20

    Testing I I I I Cinderblock Foam block Isometric and translucent view of the weighted foam block . .-.-; Weighted foam block Figure 2.3... concrete block (CB, Fig. 2.4). Conven- tional methods for identifying targets in a radar or acoustic imaging system (also known as Automatic Target...and curb, or than the grass-covered hill beyond the sidewalk. However, there is a strong acoustic return from a seam in the sidewalk concrete that runs

  2. Acoustic imaging in a water filled metallic pipe

    International Nuclear Information System (INIS)

    Kolbe, W.F.; Turko, B.T.; Leskovar, B.

    1984-04-01

    A method is described for the imaging of the interior of a water filled metallic pipe using acoustical techniques. The apparatus consists of an array of 20 acoustic transducers mounted circumferentially around the pipe. Each transducer is pulsed in sequence, and the echos resulting from bubbles in the interior are digitized and processed by a computer to generate an image. The electronic control and digitizing system and the software processing of the echo signals are described. The performance of the apparatus is illustrated by the imaging of simulated bubbles consisting of thin walled glass spheres suspended in the pipe

  3. Acoustic imaging in a water filled metallic pipe

    International Nuclear Information System (INIS)

    Kolbe, W.F.; Leskovar, B.; Turko, B.T.

    1985-01-01

    A method is described for the imaging of the interior of a water filled metallic pipe using acoustical techniques. The apparatus consists of an array of 20 acoustic transducers mounted circumferentially around the pipe. Each transducer is pulsed in sequence, and the echos resulting from bubbles in the interior are digitized and processed by a computer to generate an image. The electronic control and digitizing system and the software processing of the echo signals are described. The performance of the apparatus is illustrated by the imaging of simulated bubbles consisting of thin walled glass spheres suspended in the pipe

  4. Performance Evaluation of a Biometric System Based on Acoustic Images

    Science.gov (United States)

    Izquierdo-Fuente, Alberto; del Val, Lara; Jiménez, María I.; Villacorta, Juan J.

    2011-01-01

    An acoustic electronic scanning array for acquiring images from a person using a biometric application is developed. Based on pulse-echo techniques, multifrequency acoustic images are obtained for a set of positions of a person (front, front with arms outstretched, back and side). Two Uniform Linear Arrays (ULA) with 15 λ/2-equispaced sensors have been employed, using different spatial apertures in order to reduce sidelobe levels. Working frequencies have been designed on the basis of the main lobe width, the grating lobe levels and the frequency responses of people and sensors. For a case-study with 10 people, the acoustic profiles, formed by all images acquired, are evaluated and compared in a mean square error sense. Finally, system performance, using False Match Rate (FMR)/False Non-Match Rate (FNMR) parameters and the Receiver Operating Characteristic (ROC) curve, is evaluated. On the basis of the obtained results, this system could be used for biometric applications. PMID:22163708

  5. Performance Evaluation of a Biometric System Based on Acoustic Images

    Directory of Open Access Journals (Sweden)

    Juan J. Villacorta

    2011-10-01

    Full Text Available An acoustic electronic scanning array for acquiring images from a person using a biometric application is developed. Based on pulse-echo techniques, multifrequency acoustic images are obtained for a set of positions of a person (front, front with arms outstretched, back and side. Two Uniform Linear Arrays (ULA with 15 l/2-equispaced sensors have been employed, using different spatial apertures in order to reduce sidelobe levels. Working frequencies have been designed on the basis of the main lobe width, the grating lobe levels and the frequency responses of people and sensors. For a case-study with 10 people, the acoustic profiles, formed by all images acquired, are evaluated and compared in a mean square error sense. Finally, system performance, using False Match Rate (FMR/False Non-Match Rate (FNMR parameters and the Receiver Operating Characteristic (ROC curve, is evaluated. On the basis of the obtained results, this system could be used for biometric applications.

  6. Acoustic Angiography: A New Imaging Modality for Assessing Microvasculature Architecture

    Directory of Open Access Journals (Sweden)

    Ryan C. Gessner

    2013-01-01

    Full Text Available The purpose of this paper is to provide the biomedical imaging community with details of a new high resolution contrast imaging approach referred to as “acoustic angiography.” Through the use of dual-frequency ultrasound transducer technology, images acquired with this approach possess both high resolution and a high contrast-to-tissue ratio, which enables the visualization of microvascular architecture without significant contribution from background tissues. Additionally, volumetric vessel-tissue integration can be visualized by using b-mode overlays acquired with the same probe. We present a brief technical overview of how the images are acquired, followed by several examples of images of both healthy and diseased tissue volumes. 3D images from alternate modalities often used in preclinical imaging, contrast-enhanced micro-CT and photoacoustics, are also included to provide a perspective on how acoustic angiography has qualitatively similar capabilities to these other techniques. These preliminary images provide visually compelling evidence to suggest that acoustic angiography may serve as a powerful new tool in preclinical and future clinical imaging.

  7. Acoustic imaging of underground storage tank wastes

    International Nuclear Information System (INIS)

    Mech, S.J.

    1995-09-01

    Acoustics is a potential tool to determine the properties of high level wastes stored in Underground Storage Tanks. Some acoustic properties were successfully measured by a limited demonstration conducted in 114-TX. This accomplishment provides the basis for expanded efforts to qualify techniques which depend on the acoustic properties of tank wastes. This work is being sponsored by the Department of Energy under the Office of Science and Technology. In FY-1994, limited Tank Waste Remediation Systems EM-30 support was available at Hanford and Los Alamos National Laboratory. The Massachusetts Institute of Technology (MIT) and Earth Resources Laboratory (ERL) were engaged for analysis support, and Elohi Geophysics, Inc. for seismic testing services. Westinghouse-Hanford Company provided the testing and training, supplied the special engineering and safety analysis equipment and procedures, and provided the trained operators for the actual tank operations. On 11/9/94, limited in-tank tests were successfully conducted in tank 114-TX. This stabilized Single Shell Tank was reported as containing 16.8 feet of waste, the lower 6.28 feet of which contained interstitial liquid. Testing was conducted over the lower 12 feet, between two Liquid Observation Wells thirty feet apart. The ''quick-look'' data was reviewed on-site by MIT and Elohi

  8. Systematic Error of Acoustic Particle Image Velocimetry and Its Correction

    Directory of Open Access Journals (Sweden)

    Mickiewicz Witold

    2014-08-01

    Full Text Available Particle Image Velocimetry is getting more and more often the method of choice not only for visualization of turbulent mass flows in fluid mechanics, but also in linear and non-linear acoustics for non-intrusive visualization of acoustic particle velocity. Particle Image Velocimetry with low sampling rate (about 15Hz can be applied to visualize the acoustic field using the acquisition synchronized to the excitation signal. Such phase-locked PIV technique is described and used in experiments presented in the paper. The main goal of research was to propose a model of PIV systematic error due to non-zero time interval between acquisitions of two images of the examined sound field seeded with tracer particles, what affects the measurement of complex acoustic signals. Usefulness of the presented model is confirmed experimentally. The correction procedure, based on the proposed model, applied to measurement data increases the accuracy of acoustic particle velocity field visualization and creates new possibilities in observation of sound fields excited with multi-tonal or band-limited noise signals.

  9. Imaging and detection of mines from acoustic measurements

    Science.gov (United States)

    Witten, Alan J.; DiMarzio, Charles A.; Li, Wen; McKnight, Stephen W.

    1999-08-01

    A laboratory-scale acoustic experiment is described where a buried target, a hockey puck cut in half, is shallowly buried in a sand box. To avoid the need for source and receiver coupling to the host sand, an acoustic wave is generated in the subsurface by a pulsed laser suspended above the air-sand interface. Similarly, an airborne microphone is suspended above this interface and moved in unison with the laser. After some pre-processing of the data, reflections for the target, although weak, could clearly be identified. While the existence and location of the target can be determined by inspection of the data, its unique shape can not. Since target discrimination is important in mine detection, a 3D imaging algorithm was applied to the acquired acoustic data. This algorithm yielded a reconstructed image where the shape of the target was resolved.

  10. Synchrotron x-ray imaging of acoustic cavitation bubbles induced by acoustic excitation

    International Nuclear Information System (INIS)

    Jung, Sung Yong; Park, Han Wook; Park, Sung Ho; Lee, Sang Joon

    2017-01-01

    The cavitation induced by acoustic excitation has been widely applied in various biomedical applications because cavitation bubbles can enhance the exchanges of mass and energy. In order to minimize the hazardous effects of the induced cavitation, it is essential to understand the spatial distribution of cavitation bubbles. The spatial distribution of cavitation bubbles visualized by the synchrotron x-ray imaging technique is compared to that obtained with a conventional x-ray tube. Cavitation bubbles with high density in the region close to the tip of the probe are visualized using the synchrotron x-ray imaging technique, however, the spatial distribution of cavitation bubbles in the whole ultrasound field is not detected. In this study, the effects of the ultrasound power of acoustic excitation and working medium on the shape and density of the induced cavitation bubbles are examined. As a result, the synchrotron x-ray imaging technique is useful for visualizing spatial distributions of cavitation bubbles, and it could be used for optimizing the operation conditions of acoustic cavitation. (paper)

  11. Photo acoustic imaging: technology, systems and market trends

    Science.gov (United States)

    Faucheux, Marc; d'Humières, Benoît; Cochard, Jacques

    2017-03-01

    Although the Photo Acoustic effect was observed by Graham Bell in 1880, the first applications (gas analysis) occurred in 1970's using the required energetic light pulses from lasers. During mid 1990's medical imaging research begun to use Photo Acoustic effect and in vivo images were obtained in mid-2000. Since 2009, the number of patent related to Photo Acoustic Imaging (PAI) has dramatically increased. PAI machines for pre-clinical and small animal imaging have been being used in a routine way for several years. Based on its very interesting features (non-ionizing radiation, noninvasive, high depth resolution ratio, scalability, moderate price) and because it is able to deliver not only anatomical, but functional and molecular information, PAI is a very promising clinical imaging modality. It penetrates deeper into tissue than OCT (Optical Coherence Tomography) and provides a higher resolution than ultrasounds. The PAI is one of the most growing imaging modality and some innovative clinical systems are planned to be on market in 2017. Our study analyzes the different approaches such as photoacoustic computed tomography, 3D photoacoustic microscopy, multispectral photoacoustic tomography and endoscopy with the recent and tremendous technological progress over the past decade: advances in image reconstruction algorithms, laser technology, ultrasound detectors and miniaturization. We analyze which medical domains and applications are the most concerned and explain what should be the forthcoming medical system in the near future. We segment the market in four parts: Components and R&D, pre-clinical, analytics, clinical. We analyzed what should be, quantitatively and qualitatively, the PAI medical markets in each segment and its main trends. We point out the market accessibility (patents, regulations, clinical evaluations, clinical acceptance, funding). In conclusion, we explain the main market drivers and challenges to overcome and give a road map for medical

  12. Multi-crack imaging using nonclassical nonlinear acoustic method

    International Nuclear Information System (INIS)

    Zhang Lue; Zhang Ying; Liu Xiao-Zhou; Gong Xiu-Fen

    2014-01-01

    Solid materials with cracks exhibit the nonclassical nonlinear acoustical behavior. The micro-defects in solid materials can be detected by nonlinear elastic wave spectroscopy (NEWS) method with a time-reversal (TR) mirror. While defects lie in viscoelastic solid material with different distances from one another, the nonlinear and hysteretic stress—strain relation is established with Preisach—Mayergoyz (PM) model in crack zone. Pulse inversion (PI) and TR methods are used in numerical simulation and defect locations can be determined from images obtained by the maximum value. Since false-positive defects might appear and degrade the imaging when the defects are located quite closely, the maximum value imaging with a time window is introduced to analyze how defects affect each other and how the fake one occurs. Furthermore, NEWS-TR-NEWS method is put forward to improve NEWS-TR scheme, with another forward propagation (NEWS) added to the existing phases (NEWS and TR). In the added phase, scanner locations are determined by locations of all defects imaged in previous phases, so that whether an imaged defect is real can be deduced. NEWS-TR-NEWS method is proved to be effective to distinguish real defects from the false-positive ones. Moreover, it is also helpful to detect the crack that is weaker than others during imaging procedure. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  13. Identifying Vulnerable Plaques with Acoustic Radiation Force Impulse Imaging

    Science.gov (United States)

    Doherty, Joshua Ryan

    The rupture of arterial plaques is the most common cause of ischemic complications including stroke, the fourth leading cause of death and number one cause of long term disability in the United States. Unfortunately, because conventional diagnostic tools fail to identify plaques that confer the highest risk, often a disabling stroke and/or sudden death is the first sign of disease. A diagnostic method capable of characterizing plaque vulnerability would likely enhance the predictive ability and ultimately the treatment of stroke before the onset of clinical events. This dissertation evaluates the hypothesis that Acoustic Radiation Force Impulse (ARFI) imaging can noninvasively identify lipid regions, that have been shown to increase a plaque's propensity to rupture, within carotid artery plaques in vivo. The work detailed herein describes development efforts and results from simulations and experiments that were performed to evaluate this hypothesis. To first demonstrate feasibility and evaluate potential safety concerns, finite- element method simulations are used to model the response of carotid artery plaques to an acoustic radiation force excitation. Lipid pool visualization is shown to vary as a function of lipid pool geometry and stiffness. A comparison of the resulting Von Mises stresses indicates that stresses induced by an ARFI excitation are three orders of magnitude lower than those induced by blood pressure. This thesis also presents the development of a novel pulse inversion harmonic tracking method to reduce clutter-imposed errors in ultrasound-based tissue displacement estimates. This method is validated in phantoms and was found to reduce bias and jitter displacement errors for a marked improvement in image quality in vivo. Lastly, this dissertation presents results from a preliminary in vivo study that compares ARFI imaging derived plaque stiffness with spatially registered composition determined by a Magnetic Resonance Imaging (MRI) gold standard

  14. Multi-crack imaging using nonclassical nonlinear acoustic method

    Science.gov (United States)

    Zhang, Lue; Zhang, Ying; Liu, Xiao-Zhou; Gong, Xiu-Fen

    2014-10-01

    Solid materials with cracks exhibit the nonclassical nonlinear acoustical behavior. The micro-defects in solid materials can be detected by nonlinear elastic wave spectroscopy (NEWS) method with a time-reversal (TR) mirror. While defects lie in viscoelastic solid material with different distances from one another, the nonlinear and hysteretic stress—strain relation is established with Preisach—Mayergoyz (PM) model in crack zone. Pulse inversion (PI) and TR methods are used in numerical simulation and defect locations can be determined from images obtained by the maximum value. Since false-positive defects might appear and degrade the imaging when the defects are located quite closely, the maximum value imaging with a time window is introduced to analyze how defects affect each other and how the fake one occurs. Furthermore, NEWS-TR-NEWS method is put forward to improve NEWS-TR scheme, with another forward propagation (NEWS) added to the existing phases (NEWS and TR). In the added phase, scanner locations are determined by locations of all defects imaged in previous phases, so that whether an imaged defect is real can be deduced. NEWS-TR-NEWS method is proved to be effective to distinguish real defects from the false-positive ones. Moreover, it is also helpful to detect the crack that is weaker than others during imaging procedure.

  15. Description and validation of a combination of acoustical radiosity and the image source method

    DEFF Research Database (Denmark)

    Marbjerg, Gerd Høy; Jeong, Cheol-Ho; Brunskog, Jonas

    2014-01-01

    A model that combines image source modelling and acoustical radiosity with complex boundary con- ditions, thus including phase shifts on reflection, has been developed. The model is denoted Phased Acoustical Radiosity and Image Source Model (PARISM). It has been developed in order to be able...... to model both specular and diffuse reflections with complex-valued acoustical descriptions of the surfaces. This paper mainly describes the combination of the two models and the implementation of the angle dependent surface descriptions both in the image source model and in acoustical radiosity...

  16. Acoustic Imaging Frequency Dynamics of Ferroelectric Domains by Atomic Force Microscopy

    International Nuclear Information System (INIS)

    Kun-Yu, Zhao; Hua-Rong, Zeng; Hong-Zhang, Song; Sen-Xing, Hui; Guo-Rong, Li; Qing-Rui, Yin; Shimamura, Kiyoshi; Kannan, Chinna Venkadasamy; Villora, Encarnacion Antonia Garcia; Takekawa, Shunji; Kitamura, Kenji

    2008-01-01

    We report the acoustic imaging frequency dynamics of ferroelectric domains by low-frequency acoustic probe microscopy based on the commercial atomic force microscopy It is found that ferroelectric domain could be firstly visualized at lower frequency down to 0.5 kHz by AFM-based acoustic microscopy The frequency-dependent acoustic signal revealed a strong acoustic response in the frequency range from 7kHz to 10kHz, and reached maximum at 8.1kHz. The acoustic contrast mechanism can be ascribed to the different elastic response of ferroelectric microstructures to local elastic stress fields, which is induced by the acoustic wave transmitting in the sample when the piezoelectric transducer is vibrating and exciting acoustic wave under ac electric fields due to normal piezoelectric effects. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  17. Ultrasonic phased array with surface acoustic wave for imaging cracks

    Directory of Open Access Journals (Sweden)

    Yoshikazu Ohara

    2017-06-01

    Full Text Available To accurately measure crack lengths, we developed a real-time surface imaging method (SAW PA combining an ultrasonic phased array (PA with a surface acoustic wave (SAW. SAW PA using a Rayleigh wave with a high sensitivity to surface defects was implemented for contact testing using a wedge with the third critical angle that allows the Rayleigh wave to be generated. Here, to realize high sensitivity imaging, SAW PA was optimized in terms of the wedge and the imaging area. The improved SAW PA was experimentally demonstrated using a fatigue crack specimen made of an aluminum alloy. For further verification in more realistic specimens, SAW PA was applied to stainless-steel specimens with a fatigue crack and stress corrosion cracks (SCCs. The fatigue crack was visualized with a high signal-to-noise ratio (SNR and its length was measured with a high accuracy of better than 1 mm. The SCCs generated in the heat-affected zones (HAZs of a weld were successfully visualized with a satisfactory SNR, although responses at coarse grains appeared throughout the imaging area. The SCC lengths were accurately measured. The imaging results also precisely showed complicated distributions of SCCs, which were in excellent agreement with the optically observed distributions.

  18. Acoustic resonances in microfluidic chips: full-image micro-PIV experiments and numerical simulations.

    Science.gov (United States)

    Hagsäter, S M; Jensen, T Glasdam; Bruus, H; Kutter, J P

    2007-10-01

    We show that full-image micro-PIV analysis in combination with images of transient particle motion is a powerful tool for experimental studies of acoustic radiation forces and acoustic streaming in microfluidic chambers under piezo-actuation in the MHz range. The measured steady-state motion of both large 5 microm and small 1 microm particles can be understood in terms of the acoustic eigenmodes or standing ultra-sound waves in the given experimental microsystems. This interpretation is supported by numerical solutions of the corresponding acoustic wave equation.

  19. Transmission mode acoustic time-reversal imaging for nondestructive evaluation

    Science.gov (United States)

    Lehman, Sean K.; Devaney, Anthony J.

    2002-11-01

    In previous ASA meetings and JASA papers, the extended and formalized theory of transmission mode time reversal in which the transceivers are noncoincident was presented. When combined with the subspace concepts of a generalized MUltiple SIgnal Classification (MUSIC) algorithm, this theory is used to form super-resolution images of scatterers buried in a medium. These techniques are now applied to ultrasonic nondestructive evaluation (NDE) of parts, and shallow subsurface seismic imaging. Results are presented of NDE experiments on metal and epoxy blocks using data collected from an adaptive ultrasonic array, that is, a ''time-reversal machine,'' at Lawrence Livermore National Laboratory. Also presented are the results of seismo-acoustic subsurface probing of buried hazardous waste pits at the Idaho National Engineering and Environmental Laboratory. [Work performed under the auspices of the U.S. Department of Energy by University of California Lawrence Livermore National Laboratory under Contract No. W-7405-Eng-48.] [Work supported in part by CenSSIS, the Center for Subsurface Sensing and Imaging Systems, under the Engineering Research Centers Program of the NSF (award number EEC-9986821) as well as from Air Force Contracts No. F41624-99-D6002 and No. F49620-99-C0013.

  20. Auralisations with loudspeaker arrays from a phased combination of the image source method and acoustical radiosity

    DEFF Research Database (Denmark)

    Marbjerg, Gerd Høy

    2017-01-01

    In order to create a simulation tool that is well-suited for small rooms with low diffusion and highly absorbing ceilings, a new room acoustic simulation tool has been developed that combines a phased version of the image source with acoustical radiosity and that considers the angle dependence...... impulse response, because more directional information is available with acoustical radiosity. Small rooms with absorbing surfaces are tested, because this is the room type that PARISM is particularly useful for....

  1. Auralizations with loudspeaker arrays from a phased combination of the image source method and acoustical radiosity

    DEFF Research Database (Denmark)

    Marbjerg, Gerd Høy; Brunskog, Jonas; Jeong, Cheol-Ho

    2017-01-01

    In order to create a simulation tool that is well-suited for small rooms with low diffusion and highly absorbing ceilings, a new room acoustic simulation tool has been developed that combines a phased version of the image source with acoustical radiosity and that considers the angle dependence...... of the PARISM impulse response, because more directional information is available with acoustical radiosity. Small rooms with absorbing surfaces are tested, because this is the room type that PARISM is particularly useful for....

  2. Efficacy of passive acoustic screening: implications for the design of imager and MR-suite.

    Science.gov (United States)

    Moelker, Adriaan; Vogel, Mika W; Pattynama, Peter M T

    2003-02-01

    To investigate the efficacy of passive acoustic screening in the magnetic resonance (MR) environment by reducing direct and indirect MR-related acoustic noise, both from the patient's and health worker's perspective. Direct acoustic noise refers to sound originating from the inner and outer shrouds of the MR imager, and indirect noise to acoustic reflections from the walls of the MR suite. Sound measurements were obtained inside the magnet bore (patient position) and at the entrance of the MR imager (health worker position). Inner and outer shrouds and walls were lined with thick layers of sound insulation to eliminate the direct and indirect acoustic pathways. Sound pressure levels (SPLs) and octave band frequencies were acquired during various MR imaging sequences at 1.5 T. Inside the magnet bore, direct acoustic noise radiating from the inner shroud was most relevant, with substantial reductions of up to 18.8 dB when using passive screening of the magnetic bore. At the magnet bore entrance, blocking acoustic noise from the outer shroud and reflections showed significant reductions of 4.5 and 2.8 dB, respectively, and 9.4 dB when simultaneously applied. Inner shroud coverage contributed minimally to the overall SPL reduction. Maximum noise reduction by passive acoustic screening can be achieved by reducing direct sound conduction through the inner and outer shrouds. Additional measures to optimize the acoustic properties of the MR suite have only little effect. Copyright 2003 Wiley-Liss, Inc.

  3. A combination of the acoustic radiosity and the image source method

    DEFF Research Database (Denmark)

    Koutsouris, Georgios I.; Brunskog, Jonas; Jeong, Cheol-Ho

    2012-01-01

    A combined model for room acoustic predictions is developed, aiming to treat both diffuse and specular reflections in a unified way. Two established methods are incorporated: acoustical radiosity, accounting for the diffuse part, and the image source method, accounting for the specular part...

  4. Comparing a phased combination of acoustical radiosity and the image source method with other simulation tools

    DEFF Research Database (Denmark)

    Marbjerg, Gerd Høy; Brunskog, Jonas; Jeong, Cheol-Ho

    2015-01-01

    A phased combination of acoustical radiosity and the image source method (PARISM) has been developed in order to be able to model both specular and diffuse reflections with angle-dependent and complex-valued acoustical descriptions of the surfaces. It is of great interest to model both specular...

  5. Platforms for hyperspectral imaging, in-situ optical and acoustical imaging in urbanized regions

    Science.gov (United States)

    Bostater, Charles R.; Oney, Taylor

    2016-10-01

    Hyperspectral measurements of the water surface of urban coastal waters are presented. Oblique bidirectional reflectance factor imagery was acquired made in a turbid coastal sub estuary of the Indian River Lagoon, Florida and along coastal surf zone waters of the nearby Atlantic Ocean. Imagery was also collected using a pushbroom hyperspectral imager mounted on a fixed platform with a calibrated circular mechatronic rotation stage. Oblique imagery of the shoreline and subsurface features clearly shows subsurface bottom features and rip current features within the surf zone water column. In-situ hyperspectral optical signatures were acquired from a vessel as a function of depth to determine the attenuation spectrum in Palm Bay. A unique stationary platform methodology to acquire subsurface acoustic images showing the presence of moving bottom boundary nephelometric layers passing through the acoustic fan beam. The acoustic fan beam imagery indicated the presence of oscillatory subsurface waves in the urbanized coastal estuary. Hyperspectral imaging using the fixed platform techniques are being used to collect hyperspectral bidirectional reflectance factor (BRF) measurements from locations at buildings and bridges in order to provide new opportunities to advance our scientific understanding of aquatic environments in urbanized regions.

  6. Acoustic multimode interference and self-imaging phenomena realized in multimodal phononic crystal waveguides

    International Nuclear Information System (INIS)

    Zou, Qiushun; Yu, Tianbao; Liu, Jiangtao; Wang, Tongbiao; Liao, Qinghua; Liu, Nianhua

    2015-01-01

    We report an acoustic multimode interference effect and self-imaging phenomena in an acoustic multimode waveguide system which consists of M parallel phononic crystal waveguides (M-PnCWs). Results show that the self-imaging principle remains applicable for acoustic waveguides just as it does for optical multimode waveguides. To achieve the dispersions and replicas of the input acoustic waves produced along the propagation direction, we performed the finite element method on M-PnCWs, which support M guided modes within the target frequency range. The simulation results show that single images (including direct and mirrored images) and N-fold images (N is an integer) are identified along the propagation direction with asymmetric and symmetric incidence discussed separately. The simulated positions of the replicas agree well with the calculated values that are theoretically decided by self-imaging conditions based on the guided mode propagation analysis. Moreover, the potential applications based on this self-imaging effect for acoustic wavelength de-multiplexing and beam splitting in the acoustic field are also presented. (paper)

  7. Development of novel imaging probe for optical/acoustic radiation imaging (OARI).

    Science.gov (United States)

    Ejofodomi, O'tega A; Zderic, Vesna; Zara, Jason M

    2013-11-01

    Optical/acoustic radiation imaging (OARI) is a novel imaging modality being developed to interrogate the optical and mechanical properties of soft tissues. OARI uses acoustic radiation force to generate displacement in soft tissue. Optical images before and after the application of the force are used to generate displacement maps that provide information about the mechanical properties of the tissue under interrogation. Since the images are optical images, they also represent the optical properties of the tissue as well. In this paper, the authors present the first imaging probe that uses acoustic radiation force in conjunction with optical coherence tomography (OCT) to provide information about the optical and mechanical properties of tissues to assist in the diagnosis and staging of epithelial cancers, and in particular bladder cancer. The OARI prototype probe consisted of an OCT probe encased in a plastic sheath, a miniaturized transducer glued to a plastic holder, both of which were encased in a 10 cm stainless steel tube with an inner diameter of 10 mm. The transducer delivered an acoustic intensity of 18 W/cm(2) and the OCT probe had a spatial resolution of approximately 10-20 μm. The tube was filled with deionized water for acoustic coupling and covered by a low density polyethylene cap. The OARI probe was characterized and tested on bladder wall phantoms. The phantoms possessed Young's moduli ranging from 10.2 to 12 kPa, mass density of 1.05 g/cm(3), acoustic attenuation coefficient of 0.66 dB/cm MHz, speed of sound of 1591 m/s, and optical scattering coefficient of 1.80 mm(-1). Finite element model (FEM) theoretical simulations were performed to assess the performance of the OARI probe. The authors obtained displacements of 9.4, 8.7, and 3.4 μm for the 3%, 4%, and 5% bladder wall phantoms, respectively. This shows that the probe is capable of generating optical images, and also has the ability to generate and track displacements in tissue. This will

  8. Detection of Breast Microcalcifications Under Ultrasound Using Power Doppler and Acoustic Resonance Imaging

    National Research Council Canada - National Science Library

    Weinstein, Susan

    2003-01-01

    .... Our goal with our current project was to utilize breast sonography coupled with the technique of acoustic resonance to image and evaluate the breast micorcalcifications in patients prior to biopsy...

  9. Negative refraction imaging of acoustic metamaterial lens in the supersonic range

    Directory of Open Access Journals (Sweden)

    Jianning Han

    2014-05-01

    Full Text Available Acoustic metamaterials with negative refraction index is the most promising method to overcome the diffraction limit of acoustic imaging to achieve ultrahigh resolution. In this paper, we use localized resonant phononic crystal as the unit cell to construct the acoustic negative refraction lens. Based on the vibration model of the phononic crystal, negative quality parameters of the lens are obtained while excited near the system resonance frequency. Simulation results show that negative refraction of the acoustic lens can be achieved when a sound wave transmiting through the phononic crystal plate. The patterns of the imaging field agree well with that of the incident wave, while the dispersion is very weak. The unit cell size in the simulation is 0.0005 m and the wavelength of the sound source is 0.02 m, from which we show that acoustic signal can be manipulated through structures with dimensions much smaller than the wavelength of incident wave.

  10. Tracking Energy Flow Using a Volumetric Acoustic Intensity Imager (VAIM)

    Science.gov (United States)

    Klos, Jacob; Williams, Earl G.; Valdivia, Nicolas P.

    2006-01-01

    A new measurement device has been invented at the Naval Research Laboratory which images instantaneously the intensity vector throughout a three-dimensional volume nearly a meter on a side. The measurement device consists of a nearly transparent spherical array of 50 inexpensive microphones optimally positioned on an imaginary spherical surface of radius 0.2m. Front-end signal processing uses coherence analysis to produce multiple, phase-coherent holograms in the frequency domain each related to references located on suspect sound sources in an aircraft cabin. The analysis uses either SVD or Cholesky decomposition methods using ensemble averages of the cross-spectral density with the fixed references. The holograms are mathematically processed using spherical NAH (nearfield acoustical holography) to convert the measured pressure field into a vector intensity field in the volume of maximum radius 0.4 m centered on the sphere origin. The utility of this probe is evaluated in a detailed analysis of a recent in-flight experiment in cooperation with Boeing and NASA on NASA s Aries 757 aircraft. In this experiment the trim panels and insulation were removed over a section of the aircraft and the bare panels and windows were instrumented with accelerometers to use as references for the VAIM. Results show excellent success at locating and identifying the sources of interior noise in-flight in the frequency range of 0 to 1400 Hz. This work was supported by NASA and the Office of Naval Research.

  11. Demonstration of acoustic source localization in air using single pixel compressive imaging

    Science.gov (United States)

    Rogers, Jeffrey S.; Rohde, Charles A.; Guild, Matthew D.; Naify, Christina J.; Martin, Theodore P.; Orris, Gregory J.

    2017-12-01

    Acoustic source localization often relies on large sensor arrays that can be electronically complex and have large data storage requirements to process element level data. Recently, the concept of a single-pixel-imager has garnered interest in the electromagnetics literature due to its ability to form high quality images with a single receiver paired with shaped aperture screens that allow for the collection of spatially orthogonal measurements. Here, we present a method for creating an acoustic analog to the single-pixel-imager found in electromagnetics for the purpose of source localization. Additionally, diffraction is considered to account for screen openings comparable to the acoustic wavelength. A diffraction model is presented and incorporated into the single pixel framework. In this paper, we explore the possibility of applying single pixel localization to acoustic measurements. The method is experimentally validated with laboratory measurements made in an air waveguide.

  12. Acoustic rhinometry (AR): An Alternative Method to Image Nasal Airway Geometry

    DEFF Research Database (Denmark)

    Straszek, Sune; Pedersen, O.F.

      ACOUSTIC RHINOMETRY (AR): AN ALTERNATIVE METHOD TO IMAGE NASAL AIRWAY GEOMETRY.  INTRODUCTION AND BACKGROUND:  In human studies the acoustic reflection technique was first applied to describe the area-distance relationship of the lower airways, but later the acoustic reflection technique appeared...... to be of more use in the description of nasal cavity geometry. Applied to human subjects AR has been applied to monitor the effect of corrective surgery and mucosal effects of pharmacological interventions. In recent years, however, AR has found use also in pharmacological studies in animals ranging in size...

  13. High-spatial-resolution sub-surface imaging using a laser-based acoustic microscopy technique.

    Science.gov (United States)

    Balogun, Oluwaseyi; Cole, Garrett D; Huber, Robert; Chinn, Diane; Murray, Todd W; Spicer, James B

    2011-01-01

    Scanning acoustic microscopy techniques operating at frequencies in the gigahertz range are suitable for the elastic characterization and interior imaging of solid media with micrometer-scale spatial resolution. Acoustic wave propagation at these frequencies is strongly limited by energy losses, particularly from attenuation in the coupling media used to transmit ultrasound to a specimen, leading to a decrease in the depth in a specimen that can be interrogated. In this work, a laser-based acoustic microscopy technique is presented that uses a pulsed laser source for the generation of broadband acoustic waves and an optical interferometer for detection. The use of a 900-ps microchip pulsed laser facilitates the generation of acoustic waves with frequencies extending up to 1 GHz which allows for the resolution of micrometer-scale features in a specimen. Furthermore, the combination of optical generation and detection approaches eliminates the use of an ultrasonic coupling medium, and allows for elastic characterization and interior imaging at penetration depths on the order of several hundred micrometers. Experimental results illustrating the use of the laser-based acoustic microscopy technique for imaging micrometer-scale subsurface geometrical features in a 70-μm-thick single-crystal silicon wafer with a (100) orientation are presented.

  14. Acoustic noise reduction in T 1- and proton-density-weighted turbo spin-echo imaging.

    Science.gov (United States)

    Ott, Martin; Blaimer, Martin; Breuer, Felix; Grodzki, David; Heismann, Björn; Jakob, Peter

    2016-02-01

    To reduce acoustic noise levels in T 1-weighted and proton-density-weighted turbo spin-echo (TSE) sequences, which typically reach acoustic noise levels up to 100 dB(A) in clinical practice. Five acoustic noise reduction strategies were combined: (1) gradient ramps and shapes were changed from trapezoidal to triangular, (2) variable-encoding-time imaging was implemented to relax the phase-encoding gradient timing, (3) RF pulses were adapted to avoid the need for reversing the polarity of the slice-rewinding gradient, (4) readout bandwidth was increased to provide more time for gradient activity on other axes, (5) the number of slices per TR was reduced to limit the total gradient activity per unit time. We evaluated the influence of each measure on the acoustic noise level, and conducted in vivo measurements on a healthy volunteer. Sound recordings were taken for comparison. An overall acoustic noise reduction of up to 16.8 dB(A) was obtained by the proposed strategies (1-4) and the acquisition of half the number of slices per TR only. Image quality in terms of SNR and CNR was found to be preserved. The proposed measures in this study allowed a threefold reduction in the acoustic perception of T 1-weighted and proton-density-weighted TSE sequences compared to a standard TSE-acquisition. This could be achieved without visible degradation of image quality, showing the potential to improve patient comfort and scan acceptability.

  15. Chirped or time modulated excitation compared to short pulses for photoacoustic imaging in acoustic attenuating media

    Science.gov (United States)

    Burgholzer, P.; Motz, C.; Lang, O.; Berer, T.; Huemer, M.

    2018-02-01

    In photoacoustic imaging, optically generated acoustic waves transport the information about embedded structures to the sample surface. Usually, short laser pulses are used for the acoustic excitation. Acoustic attenuation increases for higher frequencies, which reduces the bandwidth and limits the spatial resolution. One could think of more efficient waveforms than single short pulses, such as pseudo noise codes, chirped, or harmonic excitation, which could enable a higher information-transfer from the samples interior to its surface by acoustic waves. We used a linear state space model to discretize the wave equation, such as the Stoke's equation, but this method could be used for any other linear wave equation. Linear estimators and a non-linear function inversion were applied to the measured surface data, for onedimensional image reconstruction. The proposed estimation method allows optimizing the temporal modulation of the excitation laser such that the accuracy and spatial resolution of the reconstructed image is maximized. We have restricted ourselves to one-dimensional models, as for higher dimensions the one-dimensional reconstruction, which corresponds to the acoustic wave without attenuation, can be used as input for any ultrasound imaging method, such as back-projection or time-reversal method.

  16. Acoustic imaging of vapor bubbles through optically non-transparent media

    International Nuclear Information System (INIS)

    Kolbe, W.F.; Turko, B.T.; Leskovar, B.

    1983-10-01

    A preliminary investigation of the feasibility of acoustic imaging of vapor bubbles through optically nontransparent media is described. Measurements are reported showing the echo signals produced by air filled glass spheres of various sizes positioned in an aqueous medium as well as signals produced by actual vapor bubbles within a water filled steel pipe. In addition, the influence of the metallic wall thickness and material on the amplitude of the echo signals is investigated. Finally several examples are given of the imaging of spherical bubbles within metallic pipes using a simulated array of acoustic transducers mounted circumferentially around the pipe. The measurement procedures and a description of the measuring system are also given

  17. Acoustical holographic recording with coherent optical read-out and image processing

    Science.gov (United States)

    Liu, H. K.

    1980-10-01

    New acoustic holographic wave memory devices have been designed for real-time in-situ recording applications. The basic operating principles of these devices and experimental results through the use of some of the prototypes of the devices are presented. Recording media used in the device include thermoplastic resin, Crisco vegetable oil, and Wilson corn oil. In addition, nonlinear coherent optical image processing techniques including equidensitometry, A-D conversion, and pseudo-color, all based on the new contact screen technique, are discussed with regard to the enhancement of the normally poor-resolved acoustical holographic images.

  18. On the focusing conditions in time-reversed acoustics, seismic interferometry, and Marchenko imaging

    NARCIS (Netherlands)

    Wapenaar, C.P.A.; Van der Neut, J.R.; Thorbecke, J.W.; Vasconcelos, I.; Van Manen, D.J.; Ravasi, M.

    2014-01-01

    Despite the close links between the fields of time-reversed acoustics, seismic interferometry and Marchenko imaging, a number of subtle differences exist. This paper reviews the various focusing conditions of these methods, the causality/acausality aspects of the corresponding focusing wavefields,

  19. Imaging of human tooth using ultrasound based chirp-coded nonlinear time reversal acoustics

    Czech Academy of Sciences Publication Activity Database

    Dos Santos, S.; Převorovský, Zdeněk

    2011-01-01

    Roč. 51, č. 6 (2011), s. 667-674 ISSN 0041-624X Institutional research plan: CEZ:AV0Z20760514 Keywords : TR-NEWS * chirp-coded excitation * echodentography * ultrasonic imaging Subject RIV: BI - Acoustics Impact factor: 1.838, year: 2011 http://www.sciencedirect.com/science/article/pii/S0041624X11000229

  20. A line array based near field imaging technique for characterising acoustical properties of elongated targets

    NARCIS (Netherlands)

    Driessen, F.P.G.

    1995-01-01

    With near field imaging techniques the acoustical pressure waves at distances other than the recorded can be calculated. Normally, acquisition on a two dimensional plane is necessary and extrapolation is performed by a Rayleigh integral. A near field single line instead of two dimensional plane

  1. Acoustic imaging of underground storage tank wastes: A feasibility study. Final report

    International Nuclear Information System (INIS)

    Turpening, R.; Zhu, Z.; Caravana, C.; Matarese, J.

    1995-01-01

    The objectives for this underground storage tank (UST) imaging investigation are: (1) to assess the feasibility of using acoustic methods in UST wastes, if shown to be feasible, develop and assess imaging strategies; (2) to assess the validity of using chemical simulants for the development of acoustic methods and equipment. This investigation examined the velocity of surrogates, both salt cake and sludge surrogates. In addition collected seismic cross well data in a real tank (114-TX) on the Hanford Reservation. Lastly, drawing on the knowledge of the simulants and the estimates of the velocities of the waste in tank 114-TX the authors generated a hypothetical model of waste in a tank and showed that non-linear travel time tomographic imaging would faithfully image that stratigraphy

  2. Schlieren imaging of the standing wave field in an ultrasonic acoustic levitator

    Science.gov (United States)

    Rendon, Pablo Luis; Boullosa, Ricardo R.; Echeverria, Carlos; Porta, David

    2015-11-01

    We consider a model of a single axis acoustic levitator consisting of two cylinders immersed in air and directed along the same axis. The first cylinder has a flat termination and functions as a sound emitter, and the second cylinder, which is simply a refector, has the side facing the first cylinder cut out by a spherical surface. By making the first cylinder vibrate at ultrasonic frequencies a standing wave is produced in the air between the cylinders which makes it possible, by means of the acoustic radiation pressure, to levitate one or several small objects of different shapes, such as spheres or disks. We use schlieren imaging to observe the acoustic field resulting from the levitation of one or several objects, and compare these results to previous numerical approximations of the field obtained using a finite element method. The authors acknowledge financial support from DGAPA-UNAM through project PAPIIT IN109214.

  3. Application of acoustical holography for construction shadow images in ultrasonic testing

    International Nuclear Information System (INIS)

    Kutzner, J.; Zimpfer, J.

    1977-01-01

    The full-scale, three-dimensional presentation of material defects by means of acoustical holography is limited on the one hand by an insufficient resolving power in depth of the procedure and, on the other hand, by the fact that the defects of the material to be examined often reflect mirror-like. Examined is the possible range of reducing these limitations by means of constructing shadow images of defects in ultrasonic testing without - as it is usually done - reconstructing the sonic field reflected by the flow but reconstructing the sonic field diffracted at the flow by means of acoustical holography. It has been shown that acoustical holography, during which the amplitude information is always analyzed as well as - on principle - the phase information, improves the efficiency of ultrasonic testing to a large extent. (orig.) [de

  4. Negative refraction imaging of solid acoustic waves by two-dimensional three-component phononic crystal

    International Nuclear Information System (INIS)

    Li Jing; Liu Zhengyou; Qiu Chunyin

    2008-01-01

    By using of the multiple scattering methods, we study the negative refraction imaging effect of solid acoustic waves by two-dimensional three-component phononic crystals composed of coated solid inclusions placed in solid matrix. We show that localized resonance mechanism brings on a group of flat single-mode bands in low-frequency region, which provides two equivalent frequency surfaces (EFS) close to circular. The two constant frequency surfaces correspond to two Bloch modes, a right-handed and a left-handed, whose leading mode are respectively transverse (T) and longitudinal (L) modes. The negative refraction behaviors of the two kinds of modes have been demonstrated by simulation of a Gaussian beam through a finite system. High-quality far-field imaging by a planar lens for transverse or longitudinal waves has been realized separately. This three-component phononic crystal may thus serve as a mode selector in negative refraction imaging of solid acoustic waves

  5. Methods And Systems For Using Reference Images In Acoustic Image Processing

    Science.gov (United States)

    Moore, Thomas L.; Barter, Robert Henry

    2005-01-04

    A method and system of examining tissue are provided in which a field, including at least a portion of the tissue and one or more registration fiducials, is insonified. Scattered acoustic information, including both transmitted and reflected waves, is received from the field. A representation of the field, including both the tissue and the registration fiducials, is then derived from the received acoustic radiation.

  6. High-resolution acoustic imaging at low frequencies using 3D-printed metamaterials

    Directory of Open Access Journals (Sweden)

    S. Laureti

    2016-12-01

    Full Text Available An acoustic metamaterial has been constructed using 3D printing. It contained an array of air-filled channels, whose size and shape could be varied within the design and manufacture process. In this paper we analyze both numerically and experimentally the properties of this polymer metamaterial structure, and demonstrate its use for the imaging of a sample with sub-wavelength dimensions in the audible frequency range.

  7. Underwater Acoustic Matched Field Imaging Based on Compressed Sensing

    Directory of Open Access Journals (Sweden)

    Huichen Yan

    2015-10-01

    Full Text Available Matched field processing (MFP is an effective method for underwater target imaging and localizing, but its performance is not guaranteed due to the nonuniqueness and instability problems caused by the underdetermined essence of MFP. By exploiting the sparsity of the targets in an imaging area, this paper proposes a compressive sensing MFP (CS-MFP model from wave propagation theory by using randomly deployed sensors. In addition, the model’s recovery performance is investigated by exploring the lower bounds of the coherence parameter of the CS dictionary. Furthermore, this paper analyzes the robustness of CS-MFP with respect to the displacement of the sensors. Subsequently, a coherence-excluding coherence optimized orthogonal matching pursuit (CCOOMP algorithm is proposed to overcome the high coherent dictionary problem in special cases. Finally, some numerical experiments are provided to demonstrate the effectiveness of the proposed CS-MFP method.

  8. A magnetic resonance imaging study on the articulatory and acoustic speech parameters of Malay vowels.

    Science.gov (United States)

    Zourmand, Alireza; Mirhassani, Seyed Mostafa; Ting, Hua-Nong; Bux, Shaik Ismail; Ng, Kwan Hoong; Bilgen, Mehmet; Jalaludin, Mohd Amin

    2014-07-25

    The phonetic properties of six Malay vowels are investigated using magnetic resonance imaging (MRI) to visualize the vocal tract in order to obtain dynamic articulatory parameters during speech production. To resolve image blurring due to the tongue movement during the scanning process, a method based on active contour extraction is used to track tongue contours. The proposed method efficiently tracks tongue contours despite the partial blurring of MRI images. Consequently, the articulatory parameters that are effectively measured as tongue movement is observed, and the specific shape of the tongue and its position for all six uttered Malay vowels are determined.Speech rehabilitation procedure demands some kind of visual perceivable prototype of speech articulation. To investigate the validity of the measured articulatory parameters based on acoustic theory of speech production, an acoustic analysis based on the uttered vowels by subjects has been performed. As the acoustic speech and articulatory parameters of uttered speech were examined, a correlation between formant frequencies and articulatory parameters was observed. The experiments reported a positive correlation between the constriction location of the tongue body and the first formant frequency, as well as a negative correlation between the constriction location of the tongue tip and the second formant frequency. The results demonstrate that the proposed method is an effective tool for the dynamic study of speech production.

  9. 4f-5d hybridization in a high k dielectric

    International Nuclear Information System (INIS)

    Losovyj, Ya.B.; Tang, Jinke; Wang, Wendong; Hong Yuanjia; Palshin, Vadim; Tittsworth, Roland

    2006-01-01

    While intra-atomic f-d hybridization is expected, experimental confirmation of f-d hybridization in the photoemission final state leading to 4f band structure has been limited to 5f systems and compound systems with very shallow 4f levels. We demonstrate that core 4f states can contribute to the valence band structure in a wide band gap dielectric, in this case HfO 2 in the photoemission final state. In spite of the complications of sample charging, we find evidence of symmetry in the shallow 4f levels and wave vector dependent band dispersion, the latter consistent with the crystal structure of HfO 2

  10. Acoustically modulated magnetic resonance imaging of gas-filled protein nanostructures

    Science.gov (United States)

    Lu, George J.; Farhadi, Arash; Szablowski, Jerzy O.; Lee-Gosselin, Audrey; Barnes, Samuel R.; Lakshmanan, Anupama; Bourdeau, Raymond W.; Shapiro, Mikhail G.

    2018-05-01

    Non-invasive biological imaging requires materials capable of interacting with deeply penetrant forms of energy such as magnetic fields and sound waves. Here, we show that gas vesicles (GVs), a unique class of gas-filled protein nanostructures with differential magnetic susceptibility relative to water, can produce robust contrast in magnetic resonance imaging (MRI) at sub-nanomolar concentrations, and that this contrast can be inactivated with ultrasound in situ to enable background-free imaging. We demonstrate this capability in vitro, in cells expressing these nanostructures as genetically encoded reporters, and in three model in vivo scenarios. Genetic variants of GVs, differing in their magnetic or mechanical phenotypes, allow multiplexed imaging using parametric MRI and differential acoustic sensitivity. Additionally, clustering-induced changes in MRI contrast enable the design of dynamic molecular sensors. By coupling the complementary physics of MRI and ultrasound, this nanomaterial gives rise to a distinct modality for molecular imaging with unique advantages and capabilities.

  11. Estimation of fracture roughness from the acoustic borehole televiewer image

    International Nuclear Information System (INIS)

    Bae, Dae Soek; Kim, Chun Soo; Kim, Kyung Soo; Park, Byung Yoon; Koh, Yong Kweon

    2000-12-01

    Estimation of fracture roughness - as one of the basic hydraulic fracture parameters - is very important in assessing ground water flow described by using discrete fracture network modeling. Former manual estimation of the roughness for each fracture surface of drill cores is above all a tedious, time-consuming work and will often cause some ambiguities of roughness interpretation partly due to the subjective judgements of observers, and partly due to the measuring procedure itself. However, recently, indebt to the highly reliable Televiewer data for the fracture discrimination, it has led to a guess to develop a relationship between the traditional roughness method based on a linear profiles and the method from the Televiewer image based on a ellipsoidal profile. Hence, the aim of this work is to develop an automatic evaluation algorithm for measuring the roughness from the Televiewer images. A highly reliable software named 'FRAFA' has been developed and realized to the extent that its utility merits. In the developing procedure, various problems - such as the examination of a new base line(ellipsoidal) for measuring the unevenness of fracture, the elimination of overlapping fracture signatures or noise, the wavelet estimation according to the type of fractures and the digitalization of roughness etc. - were considered. With these consideration in mind, the newly devised algorithm for the estimation of roughness curves showed a great potential not only for avoiding ambiguities of roughness interpretation but also for the judgement of roughness classification

  12. Polymer Optical Fibre Sensors for Endoscopic Opto-Acoustic Imaging

    DEFF Research Database (Denmark)

    Broadway, Christian; Gallego, Daniel; Woyessa, Getinet

    2015-01-01

    in existing publications. A great advantage can be obtained for endoscopy due to a small size and array potential to provide discrete imaging speed improvements. Optical fibre exhibits numerous advantages over conventional piezo-electric transducers, such as immunity from electromagnetic interference...... is the physical size of the device, allowing compatibility with current technology, while governing flexibility of the distal end of the endoscope based on the needs of the sensor. Polymer optical fibre (POF) presents a novel approach for endoscopic applications and has been positively discussed and compared...... and a higher resolution at small sizes. Furthermore, micro structured polymer optical fibres offer over 12 times the sensitivity of silica fibre. We present a polymer fibre Bragg grating ultrasound detector with a core diameter of 125 microns. We discuss the ultrasonic signals received and draw conclusions...

  13. Spectroscopic study of the interaction of Nd{sup +3} with amino acids: phenomenological 4f-4f intensity parameters

    Energy Technology Data Exchange (ETDEWEB)

    Jerico, Soraya; Carubelli, Celia R.; Massabni, Ana M.G.; Stucchi, Elizabeth B.; Leite, Sergio R. de A. [UNESP, Araraquara, SP (Brazil). Inst. de Quimica; Malta, Oscar [Pernambuco Univ., Recife, PE (Brazil). Dept. de Quimica Fundamental

    1998-10-01

    We have studied behaviour of the phenomenological 4f-4f intensity parameters in compounds of the Nd{sup 3+} ion with glycine, L-aspartic acid, L-glutamic acid, L-histidine, DL-malic acid and Aspartame{sup TM} in aqueous solution, as function of the pK values and partial charges on the oxygens of the carboxylate groups of these molecules. The results are discussed and qualitatively interpreted in terms of the forced electric dipole and dynamic coupling mechanisms of the 4f-4f intensities, thus indicating that the forced electric dipole mechanism is dominant. (author)

  14. Spectroscopic study of the interaction of Nd+3 with amino acids: phenomenological 4f-4f intensity parameters

    International Nuclear Information System (INIS)

    Jerico, Soraya; Carubelli, Celia R.; Massabni, Ana M.G.; Stucchi, Elizabeth B.; Leite, Sergio R. de A.; Malta, Oscar

    1998-01-01

    We have studied behaviour of the phenomenological 4f-4f intensity parameters in compounds of the Nd 3+ ion with glycine, L-aspartic acid, L-glutamic acid, L-histidine, DL-malic acid and Aspartame TM in aqueous solution, as function of the pK values and partial charges on the oxygens of the carboxylate groups of these molecules. The results are discussed and qualitatively interpreted in terms of the forced electric dipole and dynamic coupling mechanisms of the 4f-4f intensities, thus indicating that the forced electric dipole mechanism is dominant. (author)

  15. Synchronized imaging and acoustic analysis of the upper airway in patients with sleep-disordered breathing

    International Nuclear Information System (INIS)

    Chang, Yi-Chung; Pham, Van-Truong; Wang, Yung-Hung; Lin, Chen; Lo, Men-Tzung; Huon, Leh-Kiong; Wang, Pa-Chun; Chen, Yunn-Jy; Jiang, Sun-Fen; Shih, Tiffany Ting-Fang; Tran, Thi-Thao; Tsao, Jenho

    2014-01-01

    Progressive narrowing of the upper airway increases airflow resistance and can produce snoring sounds and apnea/hypopnea events associated with sleep-disordered breathing due to airway collapse. Recent studies have shown that acoustic properties during snoring can be altered with anatomic changes at the site of obstruction. To evaluate the instantaneous association between acoustic features of snoring and the anatomic sites of obstruction, a novel method was developed and applied in nine patients to extract the snoring sounds during sleep while performing dynamic magnetic resonance imaging (MRI). The degree of airway narrowing during the snoring events was then quantified by the collapse index (ratio of airway diameter preceding and during the events) and correlated with the synchronized acoustic features. A total of 201 snoring events (102 pure retropalatal and 99 combined retropalatal and retroglossal events) were recorded, and the collapse index as well as the soft tissue vibration time were significantly different between pure retropalatal (collapse index, 24  ±  11%; vibration time, 0.2  ±  0.3 s) and combined (retropalatal and retroglossal) snores (collapse index, 13  ±  7% [P ≤ 0.0001]; vibration time, 1.2  ±  0.7 s [P ≤ 0.0001]). The synchronized dynamic MRI and acoustic recordings successfully characterized the sites of obstruction and established the dynamic relationship between the anatomic site of obstruction and snoring acoustics. (paper)

  16. Spatial distribution of macroalgae along the shores of Kongsfjorden (West Spitsbergen using acoustic imaging

    Directory of Open Access Journals (Sweden)

    Kruss Aleksandra

    2017-06-01

    Full Text Available The identification of macroalgal beds is a crucial component for the description of fjord ecosystems. Direct, biological sampling is still the most popular investigation technique but acoustic methods are becoming increasingly recognized as a very efficient tool for the assessment of benthic communities. In 2007 we carried out the first acoustic survey of the littoral areas in Kongsfjorden. A 2.68 km2 area comprised within a 12.40 km2 euphotic zone was mapped along the fjord’s coast using single- and multi-beam echosounders. The singlebeam echosounder (SBES proved to be a very efficient and reliable tool for macroalgae detection in Arctic conditions. The multibeam echosounder (MBES was very useful in extending the SBES survey range, even though it’s ability in discriminating benthic communities was limited. The final result of our investigation is a map of the macroalgae distribution around the fjord, showing 39% macroalgae coverage (1.09 km2 of investigated area between isobaths -0.70 m and -30 m. Zonation analysis showed that most of the studied macroalgae areas occur up to 15 m depth (93%. These results were confirmed by biological sampling and observation in key areas. The potential of acoustic imaging of macrophytes, and a proposed methodology for the processing of acoustic data, are presented in this paper along with preliminary studies on the acoustic reflectivity of macroalgae, also highlighting differences among species. These results can be applied to future monitoring of the evolution of kelp beds in different areas of the Arctic, and in the rest of the world.

  17. Imaging of heart acoustic based on the sub-space methods using a microphone array.

    Science.gov (United States)

    Moghaddasi, Hanie; Almasganj, Farshad; Zoroufian, Arezoo

    2017-07-01

    Heart disease is one of the leading causes of death around the world. Phonocardiogram (PCG) is an important bio-signal which represents the acoustic activity of heart, typically without any spatiotemporal information of the involved acoustic sources. The aim of this study is to analyze the PCG by employing a microphone array by which the heart internal sound sources could be localized, too. In this paper, it is intended to propose a modality by which the locations of the active sources in the heart could also be investigated, during a cardiac cycle. In this way, a microphone array with six microphones is employed as the recording set up to be put on the human chest. In the following, the Group Delay MUSIC algorithm which is a sub-space based localization method is used to estimate the location of the heart sources in different phases of the PCG. We achieved to 0.14cm mean error for the sources of first heart sound (S 1 ) simulator and 0.21cm mean error for the sources of second heart sound (S 2 ) simulator with Group Delay MUSIC algorithm. The acoustical diagrams created for human subjects show distinct patterns in various phases of the cardiac cycles such as the first and second heart sounds. Moreover, the evaluated source locations for the heart valves are matched with the ones that are obtained via the 4-dimensional (4D) echocardiography applied, to a real human case. Imaging of heart acoustic map presents a new outlook to indicate the acoustic properties of cardiovascular system and disorders of valves and thereby, in the future, could be used as a new diagnostic tool. Copyright © 2017. Published by Elsevier B.V.

  18. 77 FR 321 - Section 4(f) Policy Paper

    Science.gov (United States)

    2012-01-04

    ...] Section 4(f) Policy Paper AGENCY: Federal Highway Administration (FHWA), DOT. ACTION: Notice; Request for comments. SUMMARY: This is a notice and request for comments on a draft Section 4(f) Policy Paper that will... Paper is available for download and public inspection under the docket number noted above at the Federal...

  19. Acoustic Imaging of a Turbidity Current Flowing along a Channel

    Science.gov (United States)

    Hughes Clarke, J. E.; Hiroji, A.; Cahill, L.; Fedele, J. J.

    2017-12-01

    As part of a 3 month sequence of repetitive surveys and ADCP monitoring, more than 30 turbidity currents have been identified modifying a lobe channel in 130 to 190m of water on the Squamish prodelta. For a 6 day period, daily surveys at low tide tried to capture the change resulting from a single flow. On the 8thof June three flows occurred within a half hour. Along channel multibeam images of the seabed and water column were obtained from a moving vessel immediately before, during and after the passage of the third flow. In this manner the spatial extent of the in-channel and overbank flow could be constrained. By following the flow, the spatial pattern of scattering from the flow upper surface could be examined over a 2 km length of the channel. Along channel bands of high scattering appear related to enhanced release of gas along the channel flanks. Notably, no signature of the underlying across-channel bedform modulations were evident, suggesting that the upper surface of the flow does not feel the influence of the channel floor. Overbank spillage of the flow could be detected by perturbation of a plankton scattering layer just above the seabed. Additionally, evidence of enhanced overbank deposition due to flow stripping on the outer corner of a bend was identified from backscatter changes. The specific seabed alteration due to this flow could be identified and compared with the cumulative change over three months in the channel and adjacent channel-lobe transition zone. As the flow passed under the ADCP, it had a peak velocity of over 2 m/s, a thickness of 4-5m and duration of 35 minutes. Based on the timing of the flow head when in view of the surface vessel, it was decelerating as it exited the mouth of the channel.

  20. Scanning electron-acoustic imaging of residual stress distributions in aluminum metal and ZrSiO4 multiphase ceramics

    International Nuclear Information System (INIS)

    Zhang, B.Y.; Jiang, F.M.; Shi, Y.; Yin, Q.R.; Qian, M.L.

    1997-01-01

    The scanning electron-acoustic imaging technique has been used in the characterization of the residual stress field distributions existing in the subsurface in aluminum disks and 20 vol% SiC ( w)/ZrSiO 4 multiphase ceramics left by Vicker close-quote s indentation. The experimental results reveal that the distribution areas are the plastic-elastic interchange zones. The electron-acoustic signal generation mechanism in the samples are discussed. copyright 1997 American Institute of Physics

  1. Development and validation of a combined phased acoustical radiosity and image source model for predicting sound fields in rooms

    DEFF Research Database (Denmark)

    Marbjerg, Gerd Høy; Brunskog, Jonas; Jeong, Cheol-Ho

    2015-01-01

    A model, combining acoustical radiosity and the image source method, including phase shifts on reflection, has been developed. The model is denoted Phased Acoustical Radiosity and Image Source Method (PARISM), and it has been developed in order to be able to model both specular and diffuse...... radiosity by regarding the model as being stochastic. Three methods of implementation are proposed and investigated, and finally, recommendations are made for their use. Validation of the image source method is done by comparison with finite element simulations of a rectangular room with a porous absorber...

  2. Time domain localization technique with sparsity constraint for imaging acoustic sources

    Science.gov (United States)

    Padois, Thomas; Doutres, Olivier; Sgard, Franck; Berry, Alain

    2017-09-01

    This paper addresses source localization technique in time domain for broadband acoustic sources. The objective is to accurately and quickly detect the position and amplitude of noise sources in workplaces in order to propose adequate noise control options and prevent workers hearing loss or safety risk. First, the generalized cross correlation associated with a spherical microphone array is used to generate an initial noise source map. Then a linear inverse problem is defined to improve this initial map. Commonly, the linear inverse problem is solved with an l2 -regularization. In this study, two sparsity constraints are used to solve the inverse problem, the orthogonal matching pursuit and the truncated Newton interior-point method. Synthetic data are used to highlight the performances of the technique. High resolution imaging is achieved for various acoustic sources configurations. Moreover, the amplitudes of the acoustic sources are correctly estimated. A comparison of computation times shows that the technique is compatible with quasi real-time generation of noise source maps. Finally, the technique is tested with real data.

  3. Acoustical holographic Siamese image technique for imaging radial cracks in reactor piping

    International Nuclear Information System (INIS)

    Collins, H.D.; Gribble, R.P.

    1985-04-01

    This paper describes a unique technique (i.e., ''Siamese imaging'') for imaging quasi-vertical defects in reactor pipe weldments. The Siamese image is a bi-symmetrical view of the inner surface defect. Image construction geometry consists of two probes (i.e., source/receiver) operating either from opposite sides or the same side of the defect to be imaged. As the probes are scanned across a lower surface connected defect, they encounter two images - first the normal upright image and then the inverted image. The final integrated image consists of two images connected along their baselines, thus we call it a ''Siamese image.'' The experimental imaging results on simulated and natural cracks in reactor piping weldments graphically illustrate this unique technique. Excellent images of mechanical fatique and thermal cracks were obtained on ferritic and austenitic piping

  4. The Use of Acoustic Radiation Force Decorrelation-Weighted Pulse Inversion for Enhanced Ultrasound Contrast Imaging.

    Science.gov (United States)

    Herbst, Elizabeth B; Unnikrishnan, Sunil; Wang, Shiying; Klibanov, Alexander L; Hossack, John A; Mauldin, Frank William

    2017-02-01

    The use of ultrasound imaging for cancer diagnosis and screening can be enhanced with the use of molecularly targeted microbubbles. Nonlinear imaging strategies such as pulse inversion (PI) and "contrast pulse sequences" (CPS) can be used to differentiate microbubble signal, but often fail to suppress highly echogenic tissue interfaces. This failure results in false-positive detection and potential misdiagnosis. In this study, a novel acoustic radiation force (ARF)-based approach was developed for superior microbubble signal detection. The feasibility of this technique, termed ARF decorrelation-weighted PI (ADW-PI), was demonstrated in vivo using a subcutaneous mouse tumor model. Tumors were implanted in the hindlimb of C57BL/6 mice by subcutaneous injection of MC38 cells. Lipid-shelled microbubbles were conjugated to anti-VEGFR2 antibody and administered via bolus injection. An image sequence using ARF pulses to generate microbubble motion was combined with PI imaging on a Verasonics Vantage programmable scanner. ADW-PI images were generated by combining PI images with interframe signal decorrelation data. For comparison, CPS images of the same mouse tumor were acquired using a Siemens Sequoia clinical scanner. Microbubble-bound regions in the tumor interior exhibited significantly higher signal decorrelation than static tissue (n = 9, P < 0.001). The application of ARF significantly increased microbubble signal decorrelation (n = 9, P < 0.01). Using these decorrelation measurements, ADW-PI imaging demonstrated significantly improved microbubble contrast-to-tissue ratio when compared with corresponding CPS or PI images (n = 9, P < 0.001). Contrast-to-tissue ratio improved with ADW-PI by approximately 3 dB compared with PI images and 2 dB compared with CPS images. Acoustic radiation force can be used to generate adherent microbubble signal decorrelation without microbubble bursting. When combined with PI, measurements of the resulting microbubble signal

  5. Reconstruction of an acoustic pressure field in a resonance tube by particle image velocimetry.

    Science.gov (United States)

    Kuzuu, K; Hasegawa, S

    2015-11-01

    A technique for estimating an acoustic field in a resonance tube is suggested. The estimation of an acoustic field in a resonance tube is important for the development of the thermoacoustic engine, and can be conducted employing two sensors to measure pressure. While this measurement technique is known as the two-sensor method, care needs to be taken with the location of pressure sensors when conducting pressure measurements. In the present study, particle image velocimetry (PIV) is employed instead of a pressure measurement by a sensor, and two-dimensional velocity vector images are extracted as sequential data from only a one- time recording made by a video camera of PIV. The spatial velocity amplitude is obtained from those images, and a pressure distribution is calculated from velocity amplitudes at two points by extending the equations derived for the two-sensor method. By means of this method, problems relating to the locations and calibrations of multiple pressure sensors are avoided. Furthermore, to verify the accuracy of the present method, the experiments are conducted employing the conventional two-sensor method and laser Doppler velocimetry (LDV). Then, results by the proposed method are compared with those obtained with the two-sensor method and LDV.

  6. Acoustic noise in functional magnetic resonance imaging reduces pain unpleasantness ratings.

    Science.gov (United States)

    Boyle, Y; Bentley, D E; Watson, A; Jones, A K P

    2006-07-01

    Functional magnetic resonance imaging (fMRI) is increasingly used in cognitive studies. Unfortunately, the scanner produces acoustic noise during the image acquisition process. Interference from acoustic noise is known to affect auditory, visual and motor processing, raising the possibility that acoustic interference may also modulate processing of other sensory modalities such as pain. With the increasing use of fMRI in the investigation of the mechanisms of pain perception, particularly in relation to attention, this issue has become highly relevant. Pain is a complex experience, composed of sensory-discriminative, affective-motivational and cognitive-evaluative components. The aim of this experiment was to assess the effect of MRI scanner noise, compared to white noise, on the affective (unpleasantness) and the sensory-discriminative (localisation) components of pain. Painful radiant heat from a CO(2) laser was delivered to the skin of the right forearm in 24 healthy volunteers. The volunteers attended to either pain location or pain unpleasantness during three conditions: i) no noise, ii) exposure to MRI scanner noise (85 dB) or iii) exposure to white noise (85 dB). Both MRI scanner noise and white noise significantly reduced unpleasantness ratings (from 5.1 +/- 1.6 in the control condition to 4.7 +/- 1.5 (P = 0.002) and 4.6 +/- 1.6 (P white noise respectively), whereas the ability to localise pain was not significantly affected (from 85.4 +/- 9.2% correct in the control condition to 83.1 +/- 10.3% (P = 0.06) and 83.9 +/- 9.5% (P = 0.27) with MRI scanner and white noise respectively). This phenomenon should be taken into account in the design of fMRI studies into human pain perception.

  7. Magneto-thermal-acoustic differential-frequency imaging of magnetic nanoparticle with magnetic spatial localization: a theoretical prediction

    Science.gov (United States)

    Piao, Daqing

    2017-02-01

    The magneto-thermo-acoustic effect that we predicted in 2013 refers to the generation of acoustic-pressure wave from magnetic nanoparticle (MNP) when thermally mediated under an alternating magnetic field (AMF) at a pulsed or frequency-chirped application. Several independent experimental studies have since validated magneto-thermoacoustic effect, and a latest report has discovered acoustic-wave generation from MNP at the second-harmonic frequency of the AMF when operating continuously. We propose that applying two AMFs with differing frequencies to MNP will produce acoustic-pressure wave at the summation and difference of the two frequencies, in addition to the two second-harmonic frequencies. Analysis of the specific absorption dynamics of the MNP when exposed to two AMFs of differing frequencies has shown some interesting patterns of acoustic-intensity at the multiple frequency components. The ratio of the acoustic-intensity at the summation-frequency over that of the difference-frequency is determined by the frequency-ratio of the two AMFs, but remains independent of the AMF strengths. The ratio of the acoustic-intensity at the summation- or difference-frequency over that at each of the two second-harmonic frequencies is determined by both the frequency-ratio and the field-strength-ratio of the two AMFs. The results indicate a potential strategy for localization of the source of a continuous-wave magneto-thermalacoustic signal by examining the frequency spectrum of full-field non-differentiating acoustic detection, with the field-strength ratio changed continuously at a fixed frequency-ratio. The practicalities and challenges of this magnetic spatial localization approach for magneto-thermo-acoustic imaging using a simple envisioned set of two AMFs arranged in parallel to each other are discussed.

  8. Acoustic Characterization and Enhanced Ultrasound Imaging of Long-Circulating Lipid-Coated Microbubbles.

    Science.gov (United States)

    Li, Hongbo; Yang, Yanye; Zhang, Meimei; Yin, Liping; Tu, Juan; Guo, Xiasheng; Zhang, Dong

    2018-05-01

    A long-circulating lipid-coated ultrasound (US) contrast agent was fabricated to achieve a longer wash-out time and gain more resistance against higher-mechanical index sonication. Systemic physical, acoustic, and in vivo imaging experiments were performed to better understand the underlying mechanism enabling the improvement of contrast agent performance by adjusting the physical and acoustic properties of contrast agent microbubbles. By simply altering the gas core, a kind of US contrast agent microbubble was synthesized with a similar lipid-coating shell as SonoVue microbubbles (Bracco SpA, Milan, Italy) to achieve a longer wash-out time and higher inertial cavitation threshold. To bridge the structure-performance relationship of the synthesized microbubbles, the imaging performance of the microbubbles was assessed in vivo with SonoVue as a control group. The size distribution and inertial cavitation threshold of the synthesized microbubbles were characterized, and the shell parameters of the microbubbles were determined by acoustic attenuation measurements. All of the measurements were compared with SonoVue microbubbles. The synthesized microbubbles had a spherical shape, a smooth, consistent membrane, and a uniform distribution, with an average diameter of 1.484 μm. According to the measured attenuation curve, the synthesized microbubbles resonated at around 2.8 MHz. Although the bubble's shell elasticity (0.2 ± 0.09 N/m) was comparable with SonoVue, it had relatively greater viscosity and inertial cavitation because of the different gas core. Imaging studies showed that the synthesized microbubbles had a longer circulation time and a better chance of fighting against rapid collapse than SonoVue. Nano/micrometer long-circulating lipid-coated microbubbles could be fabricated by simply altering the core composition of SonoVue microbubbles with a higher-molecular weight gas. The smaller diameter and higher inertial cavitation threshold of the

  9. Role of 4 f electrons in crystallographic and magnetic complexity

    Science.gov (United States)

    Pathak, Arjun K.; Paudyal, Durga; Mudryk, Yaroslav; Pecharsky, Vitalij K.

    2017-08-01

    The functionality of many magnetic materials critically depends on first manipulating and then taking advantage of highly nonlinear changes of properties that occur during phase transformations. Unique to lanthanides, property-defining 4 f electrons are highly localized and, as commonly accepted, play little to no role in chemical bonding. Yet here we demonstrate that the competition between 4 f -electron energy landscapes of Dy (4 f9 ) and Er (4 f11 ) is the key element of the puzzle required to explain complex interplay of magnetic and structural features observed in E r1 -xD yxC o2 , and likely many other mixed lanthanide systems. Unlike the parent binaries—DyC o2 and ErC o2 —E r1 -xD yxC o2 exhibits two successive magnetostructural transitions: a first order at TC, followed by a second order in the ferrimagnetically ordered state. Supported by first-principles calculations, our results offer new opportunities for targeted design of magnetic materials with multiple functionalities, and also provide a critical insight into the role of 4 f electrons in controlling the magnetism and structure of lanthanide intermetallics.

  10. Effect of Genetic Variability in the CYP4F2, CYP4F11, and CYP4F12 Genes on Liver mRNA Levels and Warfarin Response

    Directory of Open Access Journals (Sweden)

    J. E. Zhang

    2017-05-01

    Full Text Available Genetic polymorphisms in the gene encoding cytochrome P450 (CYP 4F2, a vitamin K oxidase, affect stable warfarin dose requirements and time to therapeutic INR. CYP4F2 is part of the CYP4F gene cluster, which is highly polymorphic and exhibits a high degree of linkage disequilibrium, making it difficult to define causal variants. Our objective was to examine the effect of genetic variability in the CYP4F gene cluster on expression of the individual CYP4F genes and warfarin response. mRNA levels of the CYP4F gene cluster were quantified in human liver samples (n = 149 obtained from a well-characterized liver bank and fine mapping of the CYP4F gene cluster encompassing CYP4F2, CYP4F11, and CYP4F12 was performed. Genome-wide association study (GWAS data from a prospective cohort of warfarin-treated patients (n = 711 was also analyzed for genetic variations across the CYP4F gene cluster. In addition, SNP-gene expression in human liver tissues and interactions between CYP4F genes were explored in silico using publicly available data repositories. We found that SNPs in CYP4F2, CYP4F11, and CYP4F12 were associated with mRNA expression in the CYP4F gene cluster. In particular, CYP4F2 rs2108622 was associated with increased CYP4F2 expression while CYP4F11 rs1060467 was associated with decreased CYP4F2 expression. Interestingly, these CYP4F2 and CYP4F11 SNPs showed similar effects with warfarin stable dose where CYP4F11 rs1060467 was associated with a reduction in daily warfarin dose requirement (∼1 mg/day, Pc = 0.017, an effect opposite to that previously reported with CYP4F2 (rs2108622. However, inclusion of either or both of these SNPs in a pharmacogenetic algorithm consisting of age, body mass index (BMI, gender, baseline clotting factor II level, CYP2C9∗2 rs1799853, CYP2C9∗3 rs1057910, and VKORC1 rs9923231 improved warfarin dose variability only by 0.5–0.7% with an improvement in dose prediction accuracy of ∼1–2%. Although there is complex

  11. Preliminary study of copper oxide nanoparticles acoustic and magnetic properties for medical imaging

    Science.gov (United States)

    Perlman, Or; Weitz, Iris S.; Azhari, Haim

    2015-03-01

    The implementation of multimodal imaging in medicine is highly beneficial as different physical properties may provide complementary information, augmented detection ability, and diagnosis verification. Nanoparticles have been recently used as contrast agents for various imaging modalities. Their significant advantage over conventional large-scale contrast agents is the ability of detection at early stages of the disease, being less prone to obstacles on their path to the target region, and possible conjunction to therapeutics. Copper ions play essential role in human health. They are used as a cofactor for multiple key enzymes involved in various fundamental biochemistry processes. Extremely small size copper oxide nanoparticles (CuO-NPs) are readily soluble in water with high colloidal stability yielding high bioavailability. The goal of this study was to examine the magnetic and acoustic characteristics of CuO-NPs in order to evaluate their potential to serve as contrast imaging agent for both MRI and ultrasound. CuO-NPs 7nm in diameter were synthesized by hot solution method. The particles were scanned using a 9.4T MRI and demonstrated a concentration dependent T1 relaxation time shortening phenomenon. In addition, it was revealed that CuO-NPs can be detected using the ultrasonic B-scan imaging. Finally, speed of sound based ultrasonic computed tomography was applied and showed that CuO-NPs can be clearly imaged. In conclusion, the preliminary results obtained, positively indicate that CuO-NPs may be imaged by both MRI and ultrasound. The results motivate additional in-vivo studies, in which the clinical utility of fused images derived from both modalities for diagnosis improvement will be studied.

  12. Non-Imaging Acoustical Properties in Monitoring Arteriovenous Hemodialysis Access. A Review

    Directory of Open Access Journals (Sweden)

    Anas Mohd Noor

    2015-12-01

    Full Text Available The limitations of the gold standard angiography technique in arteriovenous access surveillance have opened a gap for researchers to find the best way to monitor this condition with low-cost, non-invasive and continuous bedside monitoring. The phonoangiography technique has been developed prior to these limits. This measurement and monitoring technique, associated with intelligence signal processing, promises better analysis for early detection of hemodialysis access problems, such as stenosis and thrombosis. Some research groups have shown that the phonoangiography technique could identify as many as 20% of vascular diameter changes and also its frequency characteristics due to hemodialysis access problems. The frequency characteristics of these acoustical signals are presented and discussed in detail to understand the association with the stenosis level, blood flows, sensor locations, fundamental frequency bands of normal and abnormal conditions, and also the spectral energy produced. This promising technique could be used in the near future as a tool for pre-diagnosis of arteriovenous access before any further access correction by surgical techniques is required. This paper provides an extensive review of various arteriovenous access monitoring techniques based on non-imaging acoustical properties.

  13. A cross-correlation objective function for least-squares migration and visco-acoustic imaging

    KAUST Repository

    Dutta, Gaurav

    2014-08-05

    Conventional acoustic least-squares migration inverts for a reflectivity image that best matches the amplitudes of the observed data. However, for field data applications, it is not easy to match the recorded amplitudes because of the visco-elastic nature of the earth and inaccuracies in the estimation of source signature and strength at different shot locations. To relax the requirement for strong amplitude matching of least-squares migration, we use a normalized cross-correlation objective function that is only sensitive to the similarity between the predicted and the observed data. Such a normalized cross-correlation objective function is also equivalent to a time-domain phase inversion method where the main emphasis is only on matching the phase of the data rather than the amplitude. Numerical tests on synthetic and field data show that such an objective function can be used as an alternative to visco-acoustic least-squares reverse time migration (Qp-LSRTM) when there is strong attenuation in the subsurface and the estimation of the attenuation parameter Qp is insufficiently accurate.

  14. A cross-correlation objective function for least-squares migration and visco-acoustic imaging

    KAUST Repository

    Dutta, Gaurav; Sinha, Mrinal; Schuster, Gerard T.

    2014-01-01

    Conventional acoustic least-squares migration inverts for a reflectivity image that best matches the amplitudes of the observed data. However, for field data applications, it is not easy to match the recorded amplitudes because of the visco-elastic nature of the earth and inaccuracies in the estimation of source signature and strength at different shot locations. To relax the requirement for strong amplitude matching of least-squares migration, we use a normalized cross-correlation objective function that is only sensitive to the similarity between the predicted and the observed data. Such a normalized cross-correlation objective function is also equivalent to a time-domain phase inversion method where the main emphasis is only on matching the phase of the data rather than the amplitude. Numerical tests on synthetic and field data show that such an objective function can be used as an alternative to visco-acoustic least-squares reverse time migration (Qp-LSRTM) when there is strong attenuation in the subsurface and the estimation of the attenuation parameter Qp is insufficiently accurate.

  15. Empty 4f states in TmS

    International Nuclear Information System (INIS)

    Wachter, P.; Grioni, M.

    1998-01-01

    The reflectivity of TmS single crystals has been measured between 2 meV and 12 eV at room temperature and at 6 K. Besides 3p 6 -5d interband transitions a plasma edge due to free carriers is observed. In the middle infrared (near 50 meV) two sharp lines are found which are interpreted as transitions from the Fermi level into empty crystal field split 4f 13 states. A Bremsstrahlen isochromat spectroscopy (BIS) measurement supports the assumption that the empty 4f 13 state is close to the Fermi energy. (orig.)

  16. 4f and 5d magnetism in samarium

    International Nuclear Information System (INIS)

    Stunault, A.; Bernhoeft, N.; Vettier, C.; Dumesnil, K.; Dufour, C.

    2001-01-01

    We report on resonant magnetic X-ray scattering studies of a samarium epitaxial film at the samarium L 3 edge. We observe one quadrupolar resonance below the edge, reflecting the polarization of the 4f electrons, and two dipolar resonances above the edge, related to the polarization of the 5d band. We demonstrate, by following the thermal evolution of resonant magnetic intensities of both types, that the polarization of the 4f and 5d electrons present exactly the same temperature dependence, even very close to the ordering temperature, in agreement with the RKKY model for long-range magnetic order in rare earths

  17. Acoustic radiation- and streaming-induced microparticle velocities determined by microparticle image velocimetry in an ultrasound symmetry plane

    DEFF Research Database (Denmark)

    Barnkob, Rune; Augustsson, Per; Laurell, Thomas

    2012-01-01

    We present microparticle image velocimetry measurements of suspended microparticles of diameters from 0.6 to 10μm undergoing acoustophoresis in an ultrasound symmetry plane in a microchannel. The motion of the smallest particles is dominated by the Stokes drag from the induced acoustic streaming...

  18. The results of borehole acoustic imaging from a granite in the Jihlava District, Czech Republic: implications for structural geological research

    Czech Academy of Sciences Publication Activity Database

    Nováková, Lucie; Novák, P.; Brož, Milan; Sosna, K.; Pitrák, K.; Kasíková, J.; Rukavičková, L.; Maňák, L.

    2012-01-01

    Roč. 4, č. 4 (2012), s. 92-101 ISSN 1916-9779 R&D Projects: GA MPO(CZ) FR-TI1/367 Institutional research plan: CEZ:AV0Z30460519 Keywords : acoustic borehole imaging * structural geology * paleostress analysis Subject RIV: DC - Siesmology, Volcanology, Earth Structure

  19. Sci-Thur AM: YIS – 02: Imaging dose distributions through the detection of radiation-induced acoustic waves

    Energy Technology Data Exchange (ETDEWEB)

    Hickling, Susannah; Lei, Hao; Hobson, Maritza; Leger, Pierre; Wang, Xueding; El Naqa, Issam [University of Michigan, McGill University, McGill University , University of Michigan, University of Michigan/McGill University (United States)

    2016-08-15

    Purpose: X-ray acoustic computed tomography (XACT) is an emerging technique that images the dose deposited within an object following linac irradiation by detecting acoustic waves induced via the photoacoustic effect. This work shows that XACT images can be formed in soft-tissue equivalent material and that dosimetric information can be extracted from such images. Methods: Acoustic waves induced in a water tank following irradiation by a 10 MV flattening filter free photon beam were detected with an immersion ultrasound transducer at 60 angles surrounding the radiation field. A back-projection algorithm was used to reconstruct an XACT image from the detected transducer signals. Profiles extracted from XACT images were compared to profiles measured with ion chambers as per the current clinical protocol. Results: XACT images were successfully formed of simple 4 cm × 4 cm and 6 cm × 3 cm fields, as well as of more complicated multi-leaf collimator defined fields. For the 6 cm × 3 cm field, 74% and 87% of the XACT profile points in the 6 cm and 3 cm dimensions, respectively, passed a 7% / 4 mm gamma test when compared to ion chamber measurements. In a complicated puzzle piece shaped field, 86% of the pixels in an extracted profile passed a 7% / 4 mm gamma test. Conclusions: XACT is capable of imaging the dose distribution delivered by a variety of field sizes and shapes in water, and is a viable technique for both water tank and in vivo dosimetry.

  20. Particle image and acoustic Doppler velocimetry analysis of a cross-flow turbine wake

    Science.gov (United States)

    Strom, Benjamin; Brunton, Steven; Polagye, Brian

    2017-11-01

    Cross-flow turbines have advantageous properties for converting kinetic energy in wind and water currents to rotational mechanical energy and subsequently electrical power. A thorough understanding of cross-flow turbine wakes aids understanding of rotor flow physics, assists geometric array design, and informs control strategies for individual turbines in arrays. In this work, the wake physics of a scale model cross-flow turbine are investigated experimentally. Three-component velocity measurements are taken downstream of a two-bladed turbine in a recirculating water channel. Time-resolved stereoscopic particle image and acoustic Doppler velocimetry are compared for planes normal to and distributed along the turbine rotational axis. Wake features are described using proper orthogonal decomposition, dynamic mode decomposition, and the finite-time Lyapunov exponent. Consequences for downstream turbine placement are discussed in conjunction with two-turbine array experiments.

  1. Trigonal bipyramidal 5d-4f molecules with SMM behavior.

    Science.gov (United States)

    Saber, Mohamed R; Dunbar, Kim R

    2014-02-28

    A family of trigonal bipyramidal (TBP) 5d-4f cyanide bridged aggregates were synthesized that exhibit slow relaxation of the magnetization below 4 K as indicated by a signal in the out-of-phase ac susceptibility data under zero field.

  2. A spinal cord window chamber model for in vivo longitudinal multimodal optical and acoustic imaging in a murine model.

    Directory of Open Access Journals (Sweden)

    Sarah A Figley

    Full Text Available In vivo and direct imaging of the murine spinal cord and its vasculature using multimodal (optical and acoustic imaging techniques could significantly advance preclinical studies of the spinal cord. Such intrinsically high resolution and complementary imaging technologies could provide a powerful means of quantitatively monitoring changes in anatomy, structure, physiology and function of the living cord over time after traumatic injury, onset of disease, or therapeutic intervention. However, longitudinal in vivo imaging of the intact spinal cord in rodent models has been challenging, requiring repeated surgeries to expose the cord for imaging or sacrifice of animals at various time points for ex vivo tissue analysis. To address these limitations, we have developed an implantable spinal cord window chamber (SCWC device and procedures in mice for repeated multimodal intravital microscopic imaging of the cord and its vasculature in situ. We present methodology for using our SCWC to achieve spatially co-registered optical-acoustic imaging performed serially for up to four weeks, without damaging the cord or induction of locomotor deficits in implanted animals. To demonstrate the feasibility, we used the SCWC model to study the response of the normal spinal cord vasculature to ionizing radiation over time using white light and fluorescence microscopy combined with optical coherence tomography (OCT in vivo. In vivo power Doppler ultrasound and photoacoustics were used to directly visualize the cord and vascular structures and to measure hemoglobin oxygen saturation through the complete spinal cord, respectively. The model was also used for intravital imaging of spinal micrometastases resulting from primary brain tumor using fluorescence and bioluminescence imaging. Our SCWC model overcomes previous in vivo imaging challenges, and our data provide evidence of the broader utility of hybridized optical-acoustic imaging methods for obtaining

  3. Spatially resolved acoustic spectroscopy for rapid imaging of material microstructure and grain orientation

    International Nuclear Information System (INIS)

    Smith, Richard J; Li, Wenqi; Coulson, Jethro; Clark, Matt; Somekh, Michael G; Sharples, Steve D

    2014-01-01

    Measuring the grain structure of aerospace materials is very important to understand their mechanical properties and in-service performance. Spatially resolved acoustic spectroscopy is an acoustic technique utilizing surface acoustic waves to map the grain structure of a material. When combined with measurements in multiple acoustic propagation directions, the grain orientation can be obtained by fitting the velocity surface to a model. The new instrument presented here can take thousands of acoustic velocity measurements per second. The spatial and velocity resolution can be adjusted by simple modification to the system; this is discussed in detail by comparison of theoretical expectations with experimental data. (paper)

  4. Density Functional Study of Structures and Electron Affinities of BrO4F/BrO4F-

    Directory of Open Access Journals (Sweden)

    Wei Li

    2009-07-01

    Full Text Available The structures, electron affinities and bond dissociation energies of BrO4F/BrO4F− species have been investigated with five density functional theory (DFT methods with DZP++ basis sets. The planar F-Br…O2…O2 complexes possess 3A' electronic state for neutral molecule and 4A' state for the corresponding anion. Three types of the neutral-anion energy separations are the adiabatic electron affinity (EAad, the vertical electron affinity (EAvert, and the vertical detachment energy (VDE. The EAad value predicted by B3LYP method is 4.52 eV. The bond dissociation energies De (BrO4F → BrO4-mF + Om (m = 1-4 and De- (BrO4F- → BrO4-mF- + Om and BrO4F- → BrO4-mF + Om- are predicted. The adiabatic electron affinities (EAad were predicted to be 4.52 eV for F-Br…O2…O2 (3A'← 4A' (B3LYP method.

  5. Effect of MRI acoustic noise on cerebral fludeoxyglucose uptake in simultaneous MR-PET imaging.

    Science.gov (United States)

    Chonde, Daniel B; Abolmaali, Nasreddin; Arabasz, Grae; Guimaraes, Alexander R; Catana, Ciprian

    2013-05-01

    Integrated scanners capable of simultaneous positron emission tomography (PET) and magnetic resonance imaging (MRI) data acquisition are now available for human use. Although the scanners' manufacturers have made substantial efforts to understand and minimize the mutual electromagnetic interference between the 2 modalities, the potential physiological inference has not been evaluated. In this study, we have studied the influence of the acoustic noise produced by the magnetic resonance (MR) gradients on brain fludeoxyglucose (FDG) uptake in the Siemens MR-BrainPET prototype. Although particular attention was paid to the primary auditory cortex (PAC), a brain-wide analysis was also performed. The effects of the MR on the PET count rate and image quantification were first investigated in phantoms. Next, 10 healthy volunteers underwent 2 simultaneous FDG-PET/MR scans in the supine position with the FDG injection occurring inside the MR-BrainPET, alternating between a "quiet" (control) environment in which no MR sequences were run during the FDG uptake phase (the first 40 minutes after radiotracer administration) and a "noisy" (test) environment in which MR sequences were run for the entire time. Cortical and subcortical regions of interest were derived from the high-resolution morphological MR data using FreeSurfer. The changes in the FDG uptake in the FreeSurfer-derived regions of interest between the 2 conditions were analyzed from parametric and static PET images, and on a voxel-by-voxel basis using SPM8 and FreeSurfer. Only minimal to no electromagnetic interference was observed for most of the MR sequences tested, with a maximum drop in count rate of 1.5% and a maximum change in the measured activity of 1.1% in the corresponding images. The region of interest-based analysis showed statistically significant increases in the right PAC in both the parametric (9.13% [4.73%]) and static (4.18% [2.87%]) images. The SPM8 analysis showed no statistically significant

  6. Real-time contrast ultrasound muscle perfusion imaging with intermediate-power imaging coupled with acoustically durable microbubbles.

    Science.gov (United States)

    Seol, Sang-Hoon; Davidson, Brian P; Belcik, J Todd; Mott, Brian H; Goodman, Reid M; Ammi, Azzdine; Lindner, Jonathan R

    2015-06-01

    There is growing interest in limb contrast-enhanced ultrasound (CEU) perfusion imaging for the evaluation of peripheral artery disease. Because of low resting microvascular blood flow in skeletal muscle, signal enhancement during limb CEU is prohibitively low for real-time imaging. The aim of this study was to test the hypothesis that this obstacle can be overcome by intermediate- rather than low-power CEU when performed with an acoustically resilient microbubble agent. Viscoelastic properties of Definity and Sonazoid were assessed by measuring bulk modulus during incremental increases in ambient pressure to 200 mm Hg. Comparison of in vivo microbubble destruction and signal enhancement at a mechanical index (MI) of 0.1 to 0.4 was performed by sequential reduction in pulsing interval from 10 to 0.05 sec during limb CEU at 7 MHz in mice and 1.8 MHz in dogs. Destruction was also assessed by broadband signal generation during passive cavitation detection. Real-time CEU perfusion imaging with destruction-replenishment was then performed at 1.8 MHz in dogs using an MI of 0.1, 0.2, or 0.3. Sonazoid had a higher bulk modulus than Definity (66 ± 12 vs 29 ± 2 kPa, P = .02) and exhibited less inertial cavitation (destruction) at MIs ≥ 0.2. On in vivo CEU, maximal signal intensity increased incrementally with MI for both agents and was equivalent between agents except at an MI of 0.1 (60% and 85% lower for Sonazoid at 7 and 1.8 MHz, respectively, P power imaging coupled with a durable microbubble contrast agent. Copyright © 2015 American Society of Echocardiography. All rights reserved.

  7. An electrochemical and high-speed imaging study of micropore decontamination by acoustic bubble entrapment.

    Science.gov (United States)

    Offin, Douglas G; Birkin, Peter R; Leighton, Timothy G

    2014-03-14

    Electrochemical and high-speed imaging techniques are used to study the abilities of ultrasonically-activated bubbles to clean out micropores. Cylindrical pores with dimensions (diameter × depth) of 500 μm × 400 μm (aspect ratio 0.8), 125 μm × 350 μm (aspect ratio 2.8) and 50 μm × 200 μm (aspect ratio 4.0) are fabricated in glass substrates. Each pore is contaminated by filling it with an electrochemically inactive blocking organic material (thickened methyl salicylate) before the substrate is placed in a solution containing an electroactive species (Fe(CN)6(3-)). An electrode is fabricated at the base of each pore and the Faradaic current is used to monitor the decontamination as a function of time. For the largest pore, decontamination driven by ultrasound (generated by a horn type transducer) and bulk fluid flow are compared. It is shown that ultrasound is much more effective than flow alone, and that bulk fluid flow at the rates used cannot decontaminate the pore completely, but that ultrasound can. In the case of the 125 μm pore, high-speed imaging is used to elucidate the cleaning mechanisms involved in ultrasonic decontamination and reveals that acoustic bubble entrapment is a key feature. The smallest pore is used to explore the limits of decontamination and it is found that ultrasound is still effective at this size under the conditions employed.

  8. Imaging the Chicxulub central crater zone from large scale seismic acoustic wave propagation and gravity modeling

    Science.gov (United States)

    Fucugauchi, J. U.; Ortiz-Aleman, C.; Martin, R.

    2017-12-01

    Large complex craters are characterized by central uplifts that represent large-scale differential movement of deep basement from the transient cavity. Here we investigate the central sector of the large multiring Chicxulub crater, which has been surveyed by an array of marine, aerial and land-borne geophysical methods. Despite high contrasts in physical properties,contrasting results for the central uplift have been obtained, with seismic reflection surveys showing lack of resolution in the central zone. We develop an integrated seismic and gravity model for the main structural elements, imaging the central basement uplift and melt and breccia units. The 3-D velocity model built from interpolation of seismic data is validated using perfectly matched layer seismic acoustic wave propagation modeling, optimized at grazing incidence using shift in the frequency domain. Modeling shows significant lack of illumination in the central sector, masking presence of the central uplift. Seismic energy remains trapped in an upper low velocity zone corresponding to the sedimentary infill, melt/breccias and surrounding faulted blocks. After conversion of seismic velocities into a volume of density values, we use massive parallel forward gravity modeling to constrain the size and shape of the central uplift that lies at 4.5 km depth, providing a high-resolution image of crater structure.The Bouguer anomaly and gravity response of modeled units show asymmetries, corresponding to the crater structure and distribution of post-impact carbonates, breccias, melt and target sediments

  9. Assessment of liver steatosis in chicken by using acoustic radiation force impulse imaging: preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Guzman Aroca, Florentina; Serrano, Laura; Berna-Serna, Juan D.; Reus, Manuel [Virgen de la Arrixaca University Hospital, Department of Radiology, El Palmar, Murcia (Spain); Ayala, Ignacio [University of Murcia, Department of Animal Medicine and Surgery, Murcia (Spain); Castell, Maria T. [University of Murcia, Department of Cell Biology, Murcia (Spain); Garcia-Perez, Bartolome [Virgen de la Arrixaca University Hospital, Internal Medicine Service, El Palmar, Murcia (Spain)

    2010-10-15

    To evaluate acoustic radiation force impulse (ARFI) imaging as a non-invasive tool for quantification of the grades of liver steatosis in chickens. We used two different diets: a standard diet (SD group) and a hyperlipidaemic diet (HD group). The ARFI technique was performed in all the animals in the right hepatic lobe and shear wave velocity (SWV) was measured and expressed in metres per second (m/s). Plasma lipid levels were analysed. Steatosis was quantified by using semiquantitative analysis. Statistical analysis was used and Pearson's correlation coefficient was calculated. Mean SWV was 0.94 {+-} 0.16 m/s (range 0.8-1.3 m/s) in the SD group and 1.91 {+-} 0.25 m/s (range 1.3-2.2 m/s) in the HD group (p < 0.001). The lowest SWVs ({<=}1.3 m/s) corresponded to the chickens in the SD group, with 100% of the animals returning a score of 0, whereas the range of SWV in the HD group chickens was between 1.6 and 2.2 m/s. A substantial correlation was observed between SWVs with histological semiquantitative analysis of steatosis (r = 0.85, p < 0.001). ARFI imaging is a non-invasive diagnostic tool that allows discrimination between the grades of liver steatosis in chickens. (orig.)

  10. Assessment of liver steatosis in chicken by using acoustic radiation force impulse imaging: preliminary results

    International Nuclear Information System (INIS)

    Guzman Aroca, Florentina; Serrano, Laura; Berna-Serna, Juan D.; Reus, Manuel; Ayala, Ignacio; Castell, Maria T.; Garcia-Perez, Bartolome

    2010-01-01

    To evaluate acoustic radiation force impulse (ARFI) imaging as a non-invasive tool for quantification of the grades of liver steatosis in chickens. We used two different diets: a standard diet (SD group) and a hyperlipidaemic diet (HD group). The ARFI technique was performed in all the animals in the right hepatic lobe and shear wave velocity (SWV) was measured and expressed in metres per second (m/s). Plasma lipid levels were analysed. Steatosis was quantified by using semiquantitative analysis. Statistical analysis was used and Pearson's correlation coefficient was calculated. Mean SWV was 0.94 ± 0.16 m/s (range 0.8-1.3 m/s) in the SD group and 1.91 ± 0.25 m/s (range 1.3-2.2 m/s) in the HD group (p < 0.001). The lowest SWVs (≤1.3 m/s) corresponded to the chickens in the SD group, with 100% of the animals returning a score of 0, whereas the range of SWV in the HD group chickens was between 1.6 and 2.2 m/s. A substantial correlation was observed between SWVs with histological semiquantitative analysis of steatosis (r = 0.85, p < 0.001). ARFI imaging is a non-invasive diagnostic tool that allows discrimination between the grades of liver steatosis in chickens. (orig.)

  11. Effect of aberration on the acoustic field in tissue harmonic imaging (THI)

    Science.gov (United States)

    Jing, Yuan; Cleveland, Robin

    2003-10-01

    A numerical simulation was used to study the impact of an aberrating layer on the generation of the fundamental and second-harmonic (SH) field in a tissue harmonic imaging scenario. The simulation used a three-dimensional time-domain code for solving the KZK equation and accounted for arbitrary spatial variations in all acoustic properties. The aberration effect was modeled by assuming that the tissue consisted of two layers where the interface has a spatial variation C that acted like an effective phase screen. Initial experiments were carried out with sinusoidal-shaped interfaces. The sinusoidal interface produced grating lobes which were at least 6 dB larger for the fundamental signal than the SH. The energy outside of the main lobe was found to increase linearly as the amplitude of the interface variation increased. The location of the grating lobes was affected by the spatial period on the interface variation. The inhomogeneous nature of tissue was modeled with an interface with a random spatial variation. With the random interface the average sidelobe level for the fundamental was -30 dB whereas the SH had an average sidelobe level of -36 dB. [Work supported by the NSF through the Center for Subsurface Sensing and Imaging Systems.

  12. Effect of MRI Acoustic Noise on Cerebral FDG Uptake in Simultaneous MR-PET Imaging

    Science.gov (United States)

    Abolmaali, Nasreddin; Arabasz, Grae; Guimaraes, Alexander R.; Catana, Ciprian

    2013-01-01

    Integrated scanners capable of simultaneous PET and MRI data acquisition are now available for human use. Although the scanners’ manufacturers have made substantial efforts to understand and minimize the mutual electromagnetic interference between the two modalities, the potential physiological inference has not been evaluated. In this work, we have studied the influence of the acoustic noise produced by the MR gradients on brain FDG uptake in the Siemens MR-BrainPET prototype. While particular attention was paid to the primary auditory cortex (PAC), a brain-wide analysis was also performed. Methods The effects of the MR on the PET count rate and image quantification were first investigated in phantoms. Next, ten healthy volunteers underwent two simultaneous FDG-PET/MR scans in the supine position with the FDG injection occurring inside the MR-BrainPET, alternating between a “quiet” (control) environment in which no MR sequences were run during the FDG uptake phase (the first 40 minutes after radiotracer administration) and a “noisy” (test) case in which MR sequences were run for the entire time. Cortical and subcortical regions of interest (ROIs) were derived from the high-resolution morphological MR data using FreeSurfer. The changes in FDG uptake in the FreeSurfer-derived ROIs between the two conditions were analyzed from parametric and static PET images, and on a voxel-by-voxel basis using SPM8 and FreeSurfer. Results Only minimal to no electromagnetic interference was observed for most of the MR sequences tested, with a maximum drop in count rate of 1.5% and a maximum change in the measured activity of 1.1% in the corresponding images. The ROI-based analysis showed statistically significant increases in the right PAC in both the parametric (9.13±4.73%) and static (4.18±2.87%) images. SPM8 analysis showed no statistically significant clusters in any images when a p<0.05 (corrected) was used; however, a p<0.001 (uncorrected) resolved bilateral

  13. Enlarging the angle of view in Michelson-interferometer-based shearography by embedding a 4f system.

    Science.gov (United States)

    Wu, Sijin; He, Xiaoyuan; Yang, Lianxiang

    2011-07-20

    Digital shearography based on Michelson interferometers suffers from the disadvantage of a small angle of view due to the structure. We demonstrate a novel digital shearography system with a large angle of view. In the optical arrangement, the imaging lens is in front of the Michelson interferometer rather than behind it as in traditional digital shearography. Thus, the angle of view is no longer limited by the Michelson interferometer. The images transmitting between the separate lens and camera are accomplished by a 4f system in the new style of shearography. The influences of the 4f system on shearography are also discussed. © 2011 Optical Society of America

  14. TU-F-CAMPUS-I-04: Head-Only Asymmetric Gradient System Evaluation: ACR Image Quality and Acoustic Noise

    International Nuclear Information System (INIS)

    Weavers, P; Shu, Y; Tao, S; Bernstein, M; Lee, S; Piel, J; Foo, T; Mathieu, J-B

    2015-01-01

    Purpose: A high-performance head-only magnetic resonance imaging gradient system with an acquisition volume of 26 cm employing an asymmetric design for the transverse coils has been developed. It is able to reach a magnitude of 85 mT/m at a slew rate of 700 T/m/s, but operated at 80 mT/m and 500 T/m/s for this test. A challenge resulting from this asymmetric design is that the gradient nonlinearly exhibits both odd- and even-ordered terms, and as the full imaging field of view is often used, the nonlinearity is pronounced. The purpose of this work is to show the system can produce clinically useful images after an on-site gradient nonlinearity calibration and correction, and show that acoustic noise levels fall within non-significant risk (NSR) limits for standard clinical pulse sequences. Methods: The head-only gradient system was inserted into a standard 3T wide-bore scanner without acoustic damping. The ACR phantom was scanned in an 8-channel receive-only head coil and the standard American College of Radiology (ACR) MRI quality control (QC) test was performed. Acoustic noise levels were measured for several standard pulse sequences. Results: Images acquired with the head-only gradient system passed all ACR MR image quality tests; Both even and odd-order gradient distortion correction terms were required for the asymmetric gradients to pass. Acoustic noise measurements were within FDA NSR guidelines of 99 dBA (with assumed 20 dBA hearing protection) A-weighted and 140 dB for peak for all but one sequence. Note the gradient system was installed without any shroud or acoustic batting. We expect final system integration to greatly reduce noise experienced by the patient. Conclusion: A high-performance head-only asymmetric gradient system operating at 80 mT/m and 500 T/m/s conforms to FDA acoustic noise limits in all but one case, and passes all the ACR MR image quality control tests. This work was supported in part by the NIH grant 5R01EB010065

  15. TU-F-CAMPUS-I-04: Head-Only Asymmetric Gradient System Evaluation: ACR Image Quality and Acoustic Noise

    Energy Technology Data Exchange (ETDEWEB)

    Weavers, P; Shu, Y; Tao, S; Bernstein, M [Mayo Clinic, Rochester, Minnesota (United States); Lee, S; Piel, J; Foo, T [GE Global Research, Niskayuna, NY (United States); Mathieu, J-B [GE Healthcare, Florence, SC (Italy)

    2015-06-15

    Purpose: A high-performance head-only magnetic resonance imaging gradient system with an acquisition volume of 26 cm employing an asymmetric design for the transverse coils has been developed. It is able to reach a magnitude of 85 mT/m at a slew rate of 700 T/m/s, but operated at 80 mT/m and 500 T/m/s for this test. A challenge resulting from this asymmetric design is that the gradient nonlinearly exhibits both odd- and even-ordered terms, and as the full imaging field of view is often used, the nonlinearity is pronounced. The purpose of this work is to show the system can produce clinically useful images after an on-site gradient nonlinearity calibration and correction, and show that acoustic noise levels fall within non-significant risk (NSR) limits for standard clinical pulse sequences. Methods: The head-only gradient system was inserted into a standard 3T wide-bore scanner without acoustic damping. The ACR phantom was scanned in an 8-channel receive-only head coil and the standard American College of Radiology (ACR) MRI quality control (QC) test was performed. Acoustic noise levels were measured for several standard pulse sequences. Results: Images acquired with the head-only gradient system passed all ACR MR image quality tests; Both even and odd-order gradient distortion correction terms were required for the asymmetric gradients to pass. Acoustic noise measurements were within FDA NSR guidelines of 99 dBA (with assumed 20 dBA hearing protection) A-weighted and 140 dB for peak for all but one sequence. Note the gradient system was installed without any shroud or acoustic batting. We expect final system integration to greatly reduce noise experienced by the patient. Conclusion: A high-performance head-only asymmetric gradient system operating at 80 mT/m and 500 T/m/s conforms to FDA acoustic noise limits in all but one case, and passes all the ACR MR image quality control tests. This work was supported in part by the NIH grant 5R01EB010065.

  16. Differential diagnosis of idiopathic granulomatous mastitis and breast cancer using acoustic radiation force impulse imaging.

    Science.gov (United States)

    Teke, Memik; Teke, Fatma; Alan, Bircan; Türkoğlu, Ahmet; Hamidi, Cihad; Göya, Cemil; Hattapoğlu, Salih; Gumus, Metehan

    2017-01-01

    Differentiation of idiopathic granulomatous mastitis (IGM) from carcinoma with routine imaging methods, such as ultrasonography (US) and mammography, is difficult. Therefore, we evaluated the value of a newly developed noninvasive technique called acoustic radiation force impulse imaging in differentiating IGM versus malignant lesions in the breast. Four hundred and eighty-six patients, who were referred to us with a presumptive diagnosis of a mass, underwent Virtual Touch tissue imaging (VTI; Siemens) and Virtual Touch tissue quantification (VTQ; Siemens) after conventional gray-scale US. US-guided percutaneous needle biopsy was then performed on 276 lesions with clinically and radiologically suspicious features. Malignant lesions (n = 122) and IGM (n = 48) were included in the final study group. There was a statistically significant difference in shear wave velocity marginal and internal values between the IGM and malignant lesions. The median marginal velocity for IGM and malignant lesions was 3.19 m/s (minimum-maximum 2.49-5.82) and 5.05 m/s (minimum-maximum 2.09-8.46), respectively (p < 0.001). The median internal velocity for IGM and malignant lesions was 2.76 m/s (minimum-maximum 1.14-4.12) and 4.79 m/s (minimum-maximum 2.12-8.02), respectively (p < 0.001). The combination of VTI and VTQ as a complement to conventional US provides viscoelastic properties of tissues, and thus has the potential to increase the specificity of US.

  17. Detecting crack profile in concrete using digital image correlation and acoustic emission

    Directory of Open Access Journals (Sweden)

    Loukili A.

    2010-06-01

    Full Text Available Failure process in concrete structures is usually accompanied by cracking of concrete. Understanding the cracking pattern is very important while studying the failure governing criteria of concrete. The cracking phenomenon in concrete structures is usually complex and involves many microscopic mechanisms caused by material heterogeneity. Since last many years, fracture or damage analysis by experimental examinations of the cement based composites has shown importance to evaluate the cracking and damage behavior of those heterogeneous materials with damage accumulation due to microcracks development ahead of the propagating crack tip; and energy dissipation resulted during the evolution of damage in the structure. The techniques used in those experiments may be the holographic interferometry, the dye penetration, the scanning electron microscopy, the acoustic emission etc. Those methods offer either the images of the material surface to observe micro-features of the concrete with qualitative analysis, or the black-white fringe patterns of the deformation on the specimen surface, from which it is difficult to observe profiles of the damaged materials.

  18. Testicular microlithiasis and preliminary experience of acoustic radiation force impulse imaging

    International Nuclear Information System (INIS)

    Pedersen, Malene Roland; Osther, Palle Jørn Sloth; Rafaelsen, Søren Rafael

    2016-01-01

    Elastography of the testis can be used as a part of multiparametric examination of the scrotum. To determine the testicular stiffness using acoustic radiation force impulse imaging (ARFI) technique in men with testicular microlithiasis (TML). In 2013, 12 patients with diagnosed testicular microlithiasis in 2008 (mean age, 51 years; age range, 25–76 years) underwent a 5-year follow-up B-mode ultrasonography with three ARFI elastography measurements of each testis. We used a Siemens Acuson S3000 machine. No malignancy was found at the 5-year follow-up B-mode and elastography in 2013. However, we found an increase in TML; in the previous ultrasonography in 2008, eight men had bilateral TML, whereas in 2013, 10 men were diagnosed with bilateral TML. The mean elasticity of testicles with TML was 0.82 m/s (interquartile range [IQR], 0.72–0.88 m/s; range, 65–1.08 m/s). Elastography velocity of testis with TML seems to be in the same velocity range as in men with normal testis tissue

  19. Development and validation of a combined phased acoustical radiosity and image source model for predicting sound fields in rooms.

    Science.gov (United States)

    Marbjerg, Gerd; Brunskog, Jonas; Jeong, Cheol-Ho; Nilsson, Erling

    2015-09-01

    A model, combining acoustical radiosity and the image source method, including phase shifts on reflection, has been developed. The model is denoted Phased Acoustical Radiosity and Image Source Method (PARISM), and it has been developed in order to be able to model both specular and diffuse reflections with complex-valued and angle-dependent boundary conditions. This paper mainly describes the combination of the two models and the implementation of the angle-dependent boundary conditions. It furthermore describes how a pressure impulse response is obtained from the energy-based acoustical radiosity by regarding the model as being stochastic. Three methods of implementation are proposed and investigated, and finally, recommendations are made for their use. Validation of the image source method is done by comparison with finite element simulations of a rectangular room with a porous absorber ceiling. Results from the full model are compared with results from other simulation tools and with measurements. The comparisons of the full model are done for real-valued and angle-independent surface properties. The proposed model agrees well with both the measured results and the alternative theories, and furthermore shows a more realistic spatial variation than energy-based methods due to the fact that interference is considered.

  20. A simulation technique for 3D MR-guided acoustic radiation force imaging

    International Nuclear Information System (INIS)

    Payne, Allison; Bever, Josh de; Farrer, Alexis; Coats, Brittany; Parker, Dennis L.; Christensen, Douglas A.

    2015-01-01

    Purpose: In magnetic resonance-guided focused ultrasound (MRgFUS) therapies, the in situ characterization of the focal spot location and quality is critical. MR acoustic radiation force imaging (MR-ARFI) is a technique that measures the tissue displacement caused by the radiation force exerted by the ultrasound beam. This work presents a new technique to model the displacements caused by the radiation force of an ultrasound beam in a homogeneous tissue model. Methods: When a steady-state point-source force acts internally in an infinite homogeneous medium, the displacement of the material in all directions is given by the Somigliana elastostatic tensor. The radiation force field, which is caused by absorption and reflection of the incident ultrasound intensity pattern, will be spatially distributed, and the tensor formulation takes the form of a convolution of a 3D Green’s function with the force field. The dynamic accumulation of MR phase during the ultrasound pulse can be theoretically accounted for through a time-of-arrival weighting of the Green’s function. This theoretical model was evaluated experimentally in gelatin phantoms of varied stiffness (125-, 175-, and 250-bloom). The acoustic and mechanical properties of the phantoms used as parameters of the model were measured using independent techniques. Displacements at focal depths of 30- and 45-mm in the phantoms were measured by a 3D spin echo MR-ARFI segmented-EPI sequence. Results: The simulated displacements agreed with the MR-ARFI measured displacements for all bloom values and focal depths with a normalized RMS difference of 0.055 (range 0.028–0.12). The displacement magnitude decreased and the displacement pattern broadened with increased bloom value for both focal depths, as predicted by the theory. Conclusions: A new technique that models the displacements caused by the radiation force of an ultrasound beam in a homogeneous tissue model theory has been rigorously validated through comparison

  1. Seeing Sound - Image Analysis of the Lift-off Acoustic Field, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — A launch vehicle and its launch facilities are subjected to intense acoustic loads generated by the vehicle's propulsion system. The vehicle, its payload, and...

  2. An acoustic pyrometer system for tomographic thermal imaging in power plant boilers

    OpenAIRE

    Bramanti, Mauro; Gray, Antoinia; Pasini, Sauro; Salerno, Emanuele; Tonazzini, Anna

    1994-01-01

    The paper presents an acoustic pyrometry method for the reconstruction of temperature maps inside power plant boilers. It is based on measuring times-of-flight of acoustic waves along a number of straight paths in a cross-section of the boiler; via an integral relationship, these times depend on the temperature of the gaseous medium along the paths. On this basis, 2D temperature maps can be reconstructed using" suitable inversion techniques. The structure of a particular 'system for the measu...

  3. Acoustic tomography and 3-D resistivity imaging of grout filled waste cells

    International Nuclear Information System (INIS)

    Morgan, F.D.; Chauvelier, C.; Shi, Weiqun; Lesmes, D.

    1997-01-01

    The Scientific Ecology Group, Inc., (SEG) was contracted by Martin Marietta Energy Systems, Inc., to demonstrate and evaluate four grout compounds for use in stabilizing radioactive waste trenches at the Oak Ridge National Laboratory (ORNL). The demonstration site was constructed at SEG's Gallaher Road test facility in Kingston, Tennessee. SEG's objectives in this project were to compare the effectiveness of the candidate grouts and grouting procedures to hydrologically isolate the waste contained within the trenches and to stabilize the trenches against subsequent subsidence. In a separate agreement with Martin Marietta Energy Systems, MIT was contracted to demonstrate the feasibility of using high-frequency acoustic tomographic imaging to evaluate the performance of the various grouts and grouting procedures, and to monitor the stability of the grouted test cells over time. The test trench consisted of four contiguous cells, each 14 feet long x 12 feet wide x 12 feet deep. The native soil in which the test cells were constructed consisted of fine red clay which is typical of the Oak Ridge area. A plan view of the test cells is shown in Figure 1 , and a cross-sectional view of one of the cells within the trench. Each cell within the trench was filled with approximately 75 cubic yards of simulated waste. The simulated waste, which included 55 gallon drums and HEPA filters, consisted of approximately 35% metal, 15% wood, and 50% paper/plastic. After the cells were loaded with the simulated waste, the trench was covered by three feet of soil to grade, to duplicate the trench configuration commonly found at ORNL

  4. Apparatus for real-time acoustic imaging of Rayleigh-Bénard convection

    Energy Technology Data Exchange (ETDEWEB)

    Kuehn, Kerry, K.

    2008-10-28

    We have successfully designed, built and tested an experimental apparatus which is capable of providing the first real-time ultrasound images of Rayleigh-B\\'{e}nard convection in optically opaque fluids confined to large aspect ratio experimental cells. The apparatus employs a modified version of a commercially available ultrasound camera to capture images (30 frames per second) of flow patterns in a fluid undergoing Rayleigh Bénard convection. The apparatus was validated by observing convection rolls in 5cSt polydimethylsiloxane (PDMS) polymer fluid. Our first objective, after having built the apparatus, was to use it to study the sequence of transitions from diffusive to time--dependent heat transport in liquid mercury. The aim was to provide important information on pattern formation in the largely unexplored regime of very low Prandtl number fluids. Based on the theoretical stability diagram for liquid mercury, we anticipated that straight rolls should be stable over a range of Rayleigh numbers, between 1708 and approximately 1900. Though some of our power spectral densities were suggestive of the existence of weak convection, we have been unable to unambiguously visualize stable convection rolls above the theoretical onset of convection in liquid mercury. Currently, we are seeking ways to increase the sensitivity of our apparatus, such as (i) improving the acoustic impedance matching between our materials in the ultrasound path and (ii) reducing the noise level in our acoustic images due to turbulence and cavitation in the cooling fluids circulating above and below our experimental cell. If we are able to convincingly improve the sensitivity of our apparatus, and we still do not observe stable convection rolls in liquid mercury, then it may be the case that the theoretical stability diagram requires revision. In that case, either (i) straight rolls are not stable in a large aspect ratio cell at the Prandtl numbers associated with liquid mercury, or (ii

  5. The use of Acoustic Radiation Force decorrelation-weighted pulse inversion (ADW-PI) for enhanced ultrasound contrast imaging

    Science.gov (United States)

    Herbst, Elizabeth; Unnikrishnan, Sunil; Wang, Shiying; Klibanov, Alexander L.; Hossack, John A.; Mauldin, F. William

    2016-01-01

    Objectives The use of ultrasound imaging for cancer diagnosis and screening can be enhanced with the use of molecularly targeted microbubbles. Nonlinear imaging strategies such as pulse inversion (PI) and “contrast pulse sequences” (CPS) can be used to differentiate microbubble signal, but often fail to suppress highly echogenic tissue interfaces. This failure results in false positive detection and potential misdiagnosis. In this study, a novel Acoustic Radiation Force (ARF) based approach was developed for superior microbubble signal detection. The feasibility of this technique, termed ARF-decorrelation-weighted PI (ADW-PI), was demonstrated in vivo using a subcutaneous mouse tumor model. Materials and Methods Tumors were implanted in the hindlimb of C57BL/6 mice by subcutaneous injection of MC38 cells. Lipid-shelled microbubbles were conjugated to anti-VEGFR2 antibody and administered via bolus injection. An image sequence using ARF pulses to generate microbubble motion was combined with PI imaging on a Verasonics Vantage programmable scanner. ADW-PI images were generated by combining PI images with inter-frame signal decorrelation data. For comparison, CPS images of the same mouse tumor were acquired using a Siemens Sequoia clinical scanner. Results Microbubble-bound regions in the tumor interior exhibited significantly higher signal decorrelation than static tissue (n = 9, p < 0.001). The application of ARF significantly increased microbubble signal decorrelation (n = 9, p < 0.01). Using these decorrelation measurements, ADW-PI imaging demonstrated significantly improved microbubble contrast-to-tissue ratio (CTR) when compared to corresponding CPS or PI images (n = 9, p < 0.001). CTR improved with ADW-PI by approximately 3 dB compared to PI images and 2 dB compared to CPS images. Conclusions Acoustic radiation force can be used to generate adherent microbubble signal decorrelation without microbubble bursting. When combined with pulse inversion

  6. Understanding Acoustic Cavitation Initiation by Porous Nanoparticles: Toward Nanoscale Agents for Ultrasound Imaging and Therapy.

    Science.gov (United States)

    Yildirim, Adem; Chattaraj, Rajarshi; Blum, Nicholas T; Goodwin, Andrew P

    2016-08-23

    Ultrasound is widely applied in medical diagnosis and therapy due to its safety, high penetration depth, and low cost. In order to improve the contrast of sonographs and efficiency of the ultrasound therapy, echogenic gas bodies or droplets (with diameters from 200 nm to 10 µm) are often used, which are not very stable in the bloodstream and unable to penetrate into target tissues. Recently, it was demonstrated that nanobubbles stabilized by nanoparticles can nucleate ultrasound responsive microbubbles under reduced acoustic pressures, which is very promising for the development of nanoscale (ultrasound agents. However, there is still very little understanding about the effects of nanoparticle properties on the stabilization of nanobubbles and nucleation of acoustic cavitation by these nanobubbles. Here, a series of mesoporous silica nanoparticles with sizes around 100 nm but with different morphologies were synthesized to understand the effects of nanoparticle porosity, surface roughness, hydrophobicity, and hydrophilic surface modification on acoustic cavitation inception by porous nanoparticles. The chemical analyses of the nanoparticles showed that, while the nanoparticles were prepared using the same silica precursor (TEOS) and surfactant (CTAB), they revealed varying amounts of carbon impurities, hydroxyl content, and degrees of silica crosslinking. Carbon impurities or hydrophobic modification with methyl groups is found to be essential for nanobubble stabilization by mesoporous silica nanoparticles. The acoustic cavitation experiments in the presence of ethanol and/or bovine serum albumin (BSA) demonstrated that acoustic cavitation is predominantly nucleated by the nanobubbles stabilized at the nanoparticle surface not inside the mesopores. Finally, acoustic cavitation experiments with rough and smooth nanoparticles were suggested that a rough nanoparticle surface is needed to largely preserve surface nanobubbles after coating the surface with hydrophilic

  7. 28 CFR 55.5 - Coverage under section 4(f)(4).

    Science.gov (United States)

    2010-07-01

    ... THE VOTING RIGHTS ACT REGARDING LANGUAGE MINORITY GROUPS Nature of Coverage § 55.5 Coverage under section 4(f)(4). (a) Coverage formula. Section 4(f)(4) applies to any State or political subdivision in...) Coverage may be determined with regard to section 4(f)(4) on a statewide or political subdivision basis. (1...

  8. Enlarged acceptance angle of a finite size detector in photoacoustic imaging using acoustic lenses

    NARCIS (Netherlands)

    Xia, W.; Piras, D.; Heijblom, Michelle; van Hespen, Johannes C.G.; Steenbergen, Wiendelt; Manohar, Srirang; van Veldhoven, Spiridon; Prins, Christian; van Leeuwen, Ton

    2011-01-01

    A large surface area transducer is preferable to be used to detect extremely weak photoacoustic signals in mammography due to its high sensitivity. The lateral resolution is limited by the small acceptance angle of such a transducer. We introduce an excellent material for an acoustic lens used to

  9. Potential Hazards Relating to Pyrolysis of c-C4F8O, n-C4F10 and c-C4F8 in selected gaseous diffusion plant operations

    International Nuclear Information System (INIS)

    Trowbridge, L.D.

    2000-01-01

    As part of a program intended to replace the present evaporative coolant at the gaseous diffusion plants (GDPs) with a non-ozone-depleting alternate, a series of investigations of the suitability of candidate substitutes is under way. This report summarizes studies directed at estimating the chemical and thermal stability of three candidate coolants, c-C 4 F 8 O, n-C 4 F 10 and c-C 4 4F 8 , in a few specific environments to be found in gaseous diffusion plant operations

  10. Disruption of Mouse Cytochrome P450 4f14 (Cyp4f14 Gene) Causes Severe Perturbations in Vitamin E Metabolism*

    Science.gov (United States)

    Bardowell, Sabrina A.; Duan, Faping; Manor, Danny; Swanson, Joy E.; Parker, Robert S.

    2012-01-01

    Vitamin E is a family of naturally occurring and structurally related lipophilic antioxidants, one of which, α-tocopherol (α-TOH), selectively accumulates in vertebrate tissues. The ω-hydroxylase cytochrome P450–4F2 (CYP4F2) is the only human enzyme shown to metabolize vitamin E. Using cDNA cloning, cell culture expression, and activity assays, we identified Cyp4f14 as a functional murine ortholog of CYP4F2. We then investigated the effect of Cyp4f14 deletion on vitamin E metabolism and status in vivo. Cyp4f14-null mice exhibited substrate-specific reductions in liver microsomal vitamin E-ω-hydroxylase activity ranging from 93% (γ-TOH) to 48% (γ-tocotrienol). In vivo data obtained from metabolic cage studies showed whole-body reductions in metabolism of γ-TOH of 90% and of 68% for δ- and α-TOH. This metabolic deficit in Cyp4f14−/− mice was partially offset by increased fecal excretion of nonmetabolized tocopherols and of novel ω-1- and ω-2-hydroxytocopherols. 12′-OH-γ-TOH represented 41% of whole-body production of γ-TOH metabolites in Cyp4f14−/− mice fed a soybean oil diet. Despite these counterbalancing mechanisms, Cyp4f14-null mice fed this diet for 6 weeks hyper-accumulated γ-TOH (2-fold increase over wild-type littermates) in all tissues and appeared normal. We conclude that CYP4F14 is the major but not the only vitamin E-ω-hydroxylase in mice. Its disruption significantly impairs whole-body vitamin E metabolism and alters the widely conserved phenotype of preferential tissue deposition of α-TOH. This model animal and its derivatives will be valuable in determining the biological actions of specific tocopherols and tocotrienols in vivo. PMID:22665481

  11. Simultaneous observation of cavitation bubbles generated in biological tissue by high-speed optical and acoustic imaging methods

    Science.gov (United States)

    Suzuki, Kai; Iwasaki, Ryosuke; Takagi, Ryo; Yoshizawa, Shin; Umemura, Shin-ichiro

    2017-07-01

    Acoustic cavitation bubbles are useful for enhancing the heating effect in high-intensity focused ultrasound (HIFU) treatment. Many studies were conducted to investigate the behavior of such bubbles in tissue-mimicking materials, such as a transparent gel phantom; however, the detailed behavior in tissue was still unclear owing to the difficulty in optical observation. In this study, a new biological phantom was developed to observe cavitation bubbles generated in an optically shallow area of tissue. Two imaging methods, high-speed photography using light scattering and high-speed ultrasonic imaging, were used for detecting the behavior of the bubbles simultaneously. The results agreed well with each other for the area of bubble formation and the temporal change in the region of bubbles, suggesting that both methods are useful for visualizing the bubbles.

  12. Evidence from acoustic imaging for submarine volcanic activity in 2012 off the west coast of El Hierro (Canary Islands, Spain)

    Science.gov (United States)

    Pérez, Nemesio M.; Somoza, Luis; Hernández, Pedro A.; de Vallejo, Luis González; León, Ricardo; Sagiya, Takeshi; Biain, Ander; González, Francisco J.; Medialdea, Teresa; Barrancos, José; Ibáñez, Jesús; Sumino, Hirochika; Nogami, Kenji; Romero, Carmen

    2014-12-01

    We report precursory geophysical, geodetic, and geochemical signatures of a new submarine volcanic activity observed off the western coast of El Hierro, Canary Islands. Submarine manifestation of this activity has been revealed through acoustic imaging of submarine plumes detected on the 20-kHz chirp parasound subbottom profiler (TOPAS PS18) mounted aboard the Spanish RV Hespérides on June 28, 2012. Five distinct "filament-shaped" acoustic plumes emanating from the flanks of mounds have been recognized at water depth between 64 and 88 m on a submarine platform located NW El Hierro. These plumes were well imaged on TOPAS profiles as "flares" of high acoustic contrast of impedance within the water column. Moreover, visible plumes composed of white rafts floating on the sea surface and sourcing from the location of the submarine plumes were reported by aerial photographs on July 3, 2012, 5 days after acoustic plumes were recorded. In addition, several geophysical and geochemical data support the fact that these submarine vents were preceded by several precursory signatures: (i) a sharp increase of the seismic energy release and the number of daily earthquakes of magnitude ≥2.5 on June 25, 2012, (ii) significant vertical and horizontal displacements observed at the Canary Islands GPS network (Nagoya University-ITER-GRAFCAN) with uplifts up to 3 cm from June 25 to 26, 2012, (iii) an anomalous increase of the soil gas radon activity, from the end of April until the beginning of June reaching peak values of 2.7 kBq/m3 on June 3, 2012, and (iv) observed positive peak in the air-corrected value of 3He/4He ratio monitored in ground waters (8.5 atmospheric 3He/4He ratio ( R A)) at the northwestern El Hierro on June 16, 2012. Combining these submarine and subaerial information, we suggest these plumes are the consequence of submarine vents exhaling volcanic gas mixed with fine ash as consequence of an event of rapid rise of volatile-rich magma beneath the NW submarine ridge

  13. Inspection of copper canisters for spent nuclear fuel by means of ultrasound. Nonlinear acoustics, synthetic aperture imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lingvall, Fredrik; Ping Wu; Stepinski, Tadeusz [Uppsala Univ., (Sweden). Dept. of Materials Science

    2003-03-01

    This report contains results concerning inspection of copper canisters for spent nuclear fuel by means of ultrasound obtained at Signals and Systems, Uppsala University in year 2001/2002. The first chapter presents results of an investigation of a new method for synthetic aperture imaging. The new method presented here takes the form of a 2D filter based on minimum mean squared error (MMSE) criteria. The filter, which varies with the target position in two dimensions includes information about spatial impulse response (SIR) of the imaging system. Spatial resolution of the MMSE method is investigated and compared experimentally to that of the classical SAFT and phased array imaging. It is shown that the resolution of the MMSE algorithm, evaluated for imaging immersed copper specimen is superior to that observed for the two above-mentioned methods. Extended experimental and theoretical research concerning the potential of nonlinear waves and material harmonic imaging is presented in the second chapter. An experimental work is presented that was conducted using the RITEC RAM-5000 ultrasonic system capable of providing a high power tone-burst output. A new method for simulation of nonlinear acoustic waves that is a combination of the angular spectrum approach and the Burger's equation is also presented. This method was used for simulating nonlinear elastic waves radiated by the annular transducer that was used in the experiments.

  14. Inspection of copper canisters for spent nuclear fuel by means of ultrasound. Nonlinear acoustics, synthetic aperture imaging

    International Nuclear Information System (INIS)

    Lingvall, Fredrik; Ping Wu; Stepinski, Tadeusz

    2003-03-01

    This report contains results concerning inspection of copper canisters for spent nuclear fuel by means of ultrasound obtained at Signals and Systems, Uppsala University in year 2001/2002. The first chapter presents results of an investigation of a new method for synthetic aperture imaging. The new method presented here takes the form of a 2D filter based on minimum mean squared error (MMSE) criteria. The filter, which varies with the target position in two dimensions includes information about spatial impulse response (SIR) of the imaging system. Spatial resolution of the MMSE method is investigated and compared experimentally to that of the classical SAFT and phased array imaging. It is shown that the resolution of the MMSE algorithm, evaluated for imaging immersed copper specimen is superior to that observed for the two above-mentioned methods. Extended experimental and theoretical research concerning the potential of nonlinear waves and material harmonic imaging is presented in the second chapter. An experimental work is presented that was conducted using the RITEC RAM-5000 ultrasonic system capable of providing a high power tone-burst output. A new method for simulation of nonlinear acoustic waves that is a combination of the angular spectrum approach and the Burger's equation is also presented. This method was used for simulating nonlinear elastic waves radiated by the annular transducer that was used in the experiments

  15. The Acoustic Lens Design and in Vivo Use of a Multifunctional Catheter Combining Intracardiac Ultrasound Imaging and Electrophysiology Sensing

    Science.gov (United States)

    Stephens, Douglas N.; Cannata, Jonathan; Liu, Ruibin; Zhao, Jian Zhong; Shung, K. Kirk; Nguyen, Hien; Chia, Raymond; Dentinger, Aaron; Wildes, Douglas; Thomenius, Kai E.; Mahajan, Aman; Shivkumar, Kalyanam; Kim, Kang; O’Donnell, Matthew; Sahn, David

    2009-01-01

    A multifunctional 9F intracardiac imaging and electrophysiology mapping catheter was developed and tested to help guide diagnostic and therapeutic intracardiac electrophysiology (EP) procedures. The catheter tip includes a 7.25-MHz, 64-element, side-looking phased array for high resolution sector scanning. Multiple electrophysiology mapping sensors were mounted as ring electrodes near the array for electrocardiographic synchronization of ultrasound images. The catheter array elevation beam performance in particular was investigated. An acoustic lens for the distal tip array designed with a round cross section can produce an acceptable elevation beam shape; however, the velocity of sound in the lens material should be approximately 155 m/s slower than in tissue for the best beam shape and wide bandwidth performance. To help establish the catheter’s unique ability for integration with electrophysiology interventional procedures, it was used in vivo in a porcine animal model, and demonstrated both useful intracardiac echocardiographic visualization and simultaneous 3-D positional information using integrated electroanatomical mapping techniques. The catheter also performed well in high frame rate imaging, color flow imaging, and strain rate imaging of atrial and ventricular structures. PMID:18407850

  16. Preparation and characterization of conducting polyaniline-coated LiVPO4F nanocrystals with core-shell structure and its application in lithium-ion batteries

    International Nuclear Information System (INIS)

    Yan, Haiyan; Wu, Xinming; Li, Yongfei

    2015-01-01

    Highlights: • Conducting PANI-coated LiVPO 4 F has been firstly prepared and investigated. • The unique core-shell structure is helpful for the performance of LiVPO 4 F/PANI. • PANI can enhance the electronic conductivity and increase the lithium diffusion coefficient. • LiVPO 4 F/PANI nanocomposite exhibits superior capacity and cycle stability. - Abstract: In this paper, the electrochemical performance of the pure LiVPO 4 F electrode is significantly improved by coating it with the conducting polyaniline via sol-gel method followed by a self-assembly process. X-ray diffraction (XRD) results indicate that the as-prepared sample crystallized in a triclinic LiVPO 4 F phase. Scanning and transmission electron microscopy images show that the particle size of the composite is about hundreds of nanometer and the conducting layer of polyaniline is uniformly coated on the surface of LiVPO 4 F particles. Electrochemical tests reveal that the polyaniline-coated LiVPO 4 F composite exhibits superior capacity and cycle stability, delivering an initial discharge capacity of 149.3 mAh g −1 at 0.1 C in the voltage range of 3.0–4.5 V. Even at high current rates, it can still present discharge capacities of 146.7, 140.1, 131.9 and 121.5 mAh g −1 at 0.2, 1, 2 and 5 C, respectively. The superior electrochemical performance of the electrode could be attributed to the uniform conducting polymer layer, which improves the electronic conductivity and Li-ions diffusion of LiVPO 4 F. Therefore, it can be drawn a conclusion that the remarkable electrochemical performance of the polyaniline-coated LiVPO 4 F makes this 4 V-class electrode a promising alternative for next-generation lithium-ion batteries.

  17. 4f-4f absorption spectral analysis of complexation of Pr(IlI) and Nd(IlI) with fumaric acid and maleic acid in different solvents

    International Nuclear Information System (INIS)

    Singh, Th. David; Taru Taru, T.; Nimita, L.; Singh, N. Rajmuhon

    2008-01-01

    Full text: Dimensions to lanthanide co-ordination chemistry in solution become a new age with the increase use of lanthanides as PROBES in the exploration of the structural function of biomolecular reactions. Absorption difference and comparative absorption spectrophotometric studies involving 4f-4f transitions for the complexation of Pr(III)/Nd(lIl) with fumaric acid and maleic acid have been carried out in CH 3 OH,CH 3 CN, dioxane and DMF. The small chemical and structural differences due to the ligands and solvents are shown to produce significant red shift and variation in the intensities of observed 4f-4f absorption bands. The variation in the spectral energy parameters - Slater Condon (F K ), Lande spin orbit coupling constant (ζ 4f ), nephelauxetic ratio (β), bonding parameter (b 1/2 ) and percent covalency (δ) are calculated and correlated with binding of the ligands with Pr(III)/Nd(III). In addition to this experimentally calculated oscillator strengths (P) and calculated values of Judd-Ofelt electric dipole intensity parameters, T λ (λ=2,4,6) are discussed for different 4f-4f transitions in different experimental conditions to discuss the nature of bonding between Ln(lIl) and ligands. The participation of π-electron density of ligands with complexation is also discussed

  18. Comparative study of Nd(3+) emission from 4f2 5d and 4f3 configurations induced by multiphotonic process in YLF, GLF and LLF crystals

    International Nuclear Information System (INIS)

    Librantz, Andre Felipe Henriques

    2000-01-01

    Nd 3+ ultraviolet fluorescence induced by multiphotonic laser excitations was studied in Nd-doped YLiF 4 (YLF) and LuLiF 4 (LLF) crystals by using the time resolved spectroscopy technique. The UV luminescences are due to transitions between the 4f 2 5d and the 4f 3 electronic configurations of Nd 3+ ions. The 4f 2 5d configuration can be reached by direct pumping the UV transition or by multiphotonic excitation, both processes give raise to the UV emission band with a structure due to the strong phonon coupling, expected for a 5d orbital involvement in the transition. The multiphotonic excitation process is due to three photons (532 nm) sequential absorptions of 532 nm-photons by metastable levels of the 4f 3 configuration splitted by crystalline local field. The sequential excitation of Nd by the pumping laser is attributed to the 4 I 9/2 +532nm → 4 G 7/2 ground state absorption followed by the 4 G 7/2 +532 nm →2 F 5/2 and 2 F 5/2 +532 nm → 4f 2 5d excited state absorptions. The UV emissions due to 4f 2 5d configuration are parity allowed, having lifetime of 35 ns in contrast to UV emissions from 4f 3 configuration which are induced by two absorption steps and are parity forbidden showing longer lifetime of 8μs and narrow tines. The polarization effects of the UV emissions were studied and their behavior are dependent on the excited state configuration involving or not the 5d orbital. The allowed UV emissions positions were affected by the host variation more than the ones originating from the 4f 3 configuration as expected. The electronic energy of the 4f 2 5d configuration shifts to lower energy when increasing the crystal field. (author)

  19. Mainstream Smoke Chemistry and in Vitro and In Vivo Toxicity of the Reference Cigarettes 3R4F and 2R4F

    Directory of Open Access Journals (Sweden)

    Roemer E

    2014-12-01

    Full Text Available A new reference cigarette, the 3R4F, has been developed to replace the depleting supply of the 2R4F cigarette. The present study was designed to compare mainstream smoke chemistry and toxicity of the two reference cigarettes under the International Organization for Standardization (ISO machine smoking conditions, and to further compare mainstream smoke chemistry and toxicological activity of the 3R4F cigarette by two different smoking regimens, i.e., the machine smoking conditions specified by ISO and the Health Canada intensive (HCI smoking conditions.

  20. Detecting the Activation of a Self-Healing Mechanism in Concrete by Acoustic Emission and Digital Image Correlation

    Directory of Open Access Journals (Sweden)

    E. Tsangouri

    2013-01-01

    Full Text Available Autonomous crack healing in concrete is obtained when encapsulated healing agent is embedded into the material. Cracking damage in concrete elements ruptures the capsules and activates the healing process by healing agent release. Previously, the strength and stiffness recovery as well as the sealing efficiency after autonomous crack repair was well established. However, the mechanisms that trigger capsule breakage remain unknown. In parallel, the conditions under which the crack interacts with embedded capsules stay black-box. In this research, an experimental approach implementing an advanced optical and acoustic method sets up scopes to monitor and justify the crack formation and capsule breakage of concrete samples tested under three-point bending. Digital Image Correlation was used to visualize the crack opening. The optical information was the basis for an extensive and analytical study of the damage by Acoustic Emission analysis. The influence of embedding capsules on the concrete fracture process, the location of capsule damage, and the differentiation between emissions due to capsule rupture and crack formation are presented in this research. A profound observation of the capsules performance provides a clear view of the healing activation process.

  1. Real-time algorithm for acoustic imaging with a microphone array.

    Science.gov (United States)

    Huang, Xun

    2009-05-01

    Acoustic phased array has become an important testing tool in aeroacoustic research, where the conventional beamforming algorithm has been adopted as a classical processing technique. The computation however has to be performed off-line due to the expensive cost. An innovative algorithm with real-time capability is proposed in this work. The algorithm is similar to a classical observer in the time domain while extended for the array processing to the frequency domain. The observer-based algorithm is beneficial mainly for its capability of operating over sampling blocks recursively. The expensive experimental time can therefore be reduced extensively since any defect in a testing can be corrected instantaneously.

  2. Localized Acoustic Surface Modes

    KAUST Repository

    Farhat, Mohamed

    2015-08-04

    We introduce the concept of localized acoustic surface modes (ASMs). We demonstrate that they are induced on a two-dimensional cylindrical rigid surface with subwavelength corrugations under excitation by an incident acoustic plane wave. Our results show that the corrugated rigid surface is acoustically equivalent to a cylindrical scatterer with uniform mass density that can be represented using a Drude-like model. This, indeed, suggests that plasmonic-like acoustic materials can be engineered with potential applications in various areas including sensing, imaging, and cloaking.

  3. Experimental demonstration of passive acoustic imaging in the human skull cavity using CT-based aberration corrections.

    Science.gov (United States)

    Jones, Ryan M; O'Reilly, Meaghan A; Hynynen, Kullervo

    2015-07-01

    Experimentally verify a previously described technique for performing passive acoustic imaging through an intact human skull using noninvasive, computed tomography (CT)-based aberration corrections Jones et al. [Phys. Med. Biol. 58, 4981-5005 (2013)]. A sparse hemispherical receiver array (30 cm diameter) consisting of 128 piezoceramic discs (2.5 mm diameter, 612 kHz center frequency) was used to passively listen through ex vivo human skullcaps (n = 4) to acoustic emissions from a narrow-band fixed source (1 mm diameter, 516 kHz center frequency) and from ultrasound-stimulated (5 cycle bursts, 1 Hz pulse repetition frequency, estimated in situ peak negative pressure 0.11-0.33 MPa, 306 kHz driving frequency) Definity™ microbubbles flowing through a thin-walled tube phantom. Initial in vivo feasibility testing of the method was performed. The performance of the method was assessed through comparisons to images generated without skull corrections, with invasive source-based corrections, and with water-path control images. For source locations at least 25 mm from the inner skull surface, the modified reconstruction algorithm successfully restored a single focus within the skull cavity at a location within 1.25 mm from the true position of the narrow-band source. The results obtained from imaging single bubbles are in good agreement with numerical simulations of point source emitters and the authors' previous experimental measurements using source-based skull corrections O'Reilly et al. [IEEE Trans. Biomed. Eng. 61, 1285-1294 (2014)]. In a rat model, microbubble activity was mapped through an intact human skull at pressure levels below and above the threshold for focused ultrasound-induced blood-brain barrier opening. During bursts that led to coherent bubble activity, the location of maximum intensity in images generated with CT-based skull corrections was found to deviate by less than 1 mm, on average, from the position obtained using source-based corrections. Taken

  4. Targeting Synthetic Lethal Interactions between Myc and the eIF4F Complex Impedes Tumorigenesis

    Directory of Open Access Journals (Sweden)

    Chen-Ju Lin

    2012-04-01

    Full Text Available The energetically demanding process of translation is linked to multiple signaling events through mTOR-mediated regulation of eukaryotic initiation factor (eIF4F complex assembly. Disrupting mTOR constraints on eIF4F activity can be oncogenic and alter chemotherapy response, making eIF4F an attractive antineoplastic target. Here, we combine a newly developed inducible RNAi platform and pharmacological targeting of eIF4F activity to define a critical role for endogenous eIF4F in Myc-dependent tumor initiation. We find elevated Myc levels are associated with deregulated eIF4F activity in the prelymphomatous stage of the Eμ-Myc lymphoma model. Inhibition of eIF4F is synthetic lethal with elevated Myc in premalignant pre-B/B cells resulting in reduced numbers of cycling pre-B/B cells and delayed tumor onset. At the organismal level, eIF4F suppression affected a subset of normal regenerating cells, but this was well tolerated and rapidly and completely reversible. Therefore, eIF4F is a key Myc client that represents a tumor-specific vulnerability.

  5. Assessing hepatic fibrosis: comparing the intravoxel incoherent motion in MRI with acoustic radiation force impulse imaging in US

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Chih-Horng; Liang, Po-Chin; Shih, Tiffany Ting-Fang [National Taiwan University Hospital, Department of Medical Imaging, Taipei (China); National Taiwan University College of Medicine, Department of Radiology, Taipei (China); Ho, Ming-Chih; Hu, Rey-Heng; Lai, Hong-Shiee [National Taiwan University Hospital and College of Medicine, Department of Surgery, Taipei (China); Jeng, Yung-Ming [National Taiwan University Hospital and College of Medicine, Department of Pathology, Taipei (China)

    2015-12-15

    This study compared the diagnostic performance of intravoxel incoherent motion (IVIM) in magnetic resonance imaging (MRI) and acoustic radiation force impulse imaging (ARFI) in ultrasound (US) for liver fibrosis (LF) evaluation. A total of 49 patients scheduled for liver surgery were recruited. LF in the non-tumorous liver parenchyma at the right lobe was estimated using a slow diffusion coefficient, fast diffusion coefficient (D{sub fast}), perfusion fraction (f) of the IVIM parameters, the total apparent diffusion coefficient of conventional diffusion-weighted imaging and the shear wave velocity (Vs) of ARFI. LF was graded using the Metavir scoring system on histological examination. The Spearman rank correlation coefficient for correlation and analysis of variance was used for determining difference. The diagnostic performance was compared using receiver operating characteristic curve analysis. LF exhibited significant correlation with the three parameters D{sub fast}, f, and Vs (r = -0.528, -0.337, and 0.481, respectively, P < 0.05). The D{sub fast} values in the F4 group were significantly lower than those in the F0, F1 and F2 groups. D{sub fast} exhibited a non-inferior performance for diagnosing all fibrosis grades compared with that of Vs. Both IVIM and ARFI provide reliable estimations for the noninvasive assessment of LF. (orig.)

  6. Photo-Acoustic Ultrasound Imaging to Distinguish Benign from Malignant Prostate Cancer

    Science.gov (United States)

    2016-09-01

    tissue phantoms and animal models of disease . 15. SUBJECT TERMS Photoacoustic, Ultrasound imaging, transurethral probe 16. SECURITY CLASSIFICATION...visible, ultrasound images are unable to discriminate between benign or malignant cancers. In photoacoustic imaging, laser energy is transmitted ...40 g/L concentration of sea plaque agarose into DI water heated to approximately 80°C. A 10 g/L concentration of silica powder was then added to

  7. Early Detection of Clinically Significant Prostate Cancer Using Ultrasonic Acoustic Radiation Force Impulse (ARFI) Imaging

    Science.gov (United States)

    2017-10-01

    Toolkit for rapid 3D visualization and image volume interpretation, followed by automated transducer positioning in a user-selected image plane for... Toolkit (IGSTK) to enable rapid 3D visualization and image volume interpretation followed by automated transducer positioning in the user-selected... careers in science, technology, and the humanities. What do you plan to do during the next reporting period to accomplish the goals? If this

  8. Architectural acoustics

    National Research Council Canada - National Science Library

    Long, Marshall

    2014-01-01

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

  9. Acoustic emission

    International Nuclear Information System (INIS)

    Nichols, R.W.

    1976-01-01

    The volume contains six papers which together provide an overall review of the inspection technique known as acoustic emission or stress wave emission. The titles are: a welder's introduction to acoustic emission technology; use of acoustic emission for detection of defects as they arise during fabrication; examples of laboratory application and assessment of acoustic emission in the United Kingdom; (Part I: acoustic emission behaviour of low alloy steels; Part II: fatigue crack assessment from proof testing and continuous monitoring); inspection of selected areas of engineering structures by acoustic emission; Japanese experience in laboratory and practical applications of acoustic emission to welded structures; and ASME acoustic emission code status. (U.K.)

  10. Pionic 4f-3d X-rays from 208Pb and 209Bi

    International Nuclear Information System (INIS)

    Olin, A.; Forsman, J.W.; MacDonald, J.A.; Marshall, G.M.; Numao, T.; Poffenberger, P.R.; Van Esbroek, P.; Kunselman, A.R.; Olaniyi, B.H.

    1985-01-01

    The X-ray energies and widths of the pionic 4f-3d and 5g-4f transitions have been measured in 208 Pb and 209 Bi. The 3d widths obtained are in reasonable agreement with theory, and do not support the anomalously small values previously reported. (orig.)

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

    International Nuclear Information System (INIS)

    Stepinski, Tadeusz; Olofsson, Tomas; Wennerstroem, Erik

    2006-12-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-12-15

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

  13. Experimental investigation on the fracture behaviour of black shale by acoustic emission monitoring and CT image analysis during uniaxial compression

    Science.gov (United States)

    Wang, Y.; Li, C. H.; Hu, Y. Z.

    2018-04-01

    Plenty of mechanical experiments have been done to investigate the deformation and failure characteristics of shale; however, the anisotropic failure mechanism has not been well studied. Here, laboratory Uniaxial Compressive Strength tests on cylindrical shale samples obtained by drilling at different inclinations to bedding plane were performed. The failure behaviours of the shale samples were studied by real-time acoustic emission (AE) monitoring and post-test X-ray computer tomography (CT) analysis. The experimental results suggest that the pronounced bedding planes of shale have a great influence on the mechanical properties and AE patterns. The AE counts and AE cumulative energy release curves clearly demonstrate different morphology, and the `U'-shaped curve relationship between the AE counts, AE cumulative energy release and bedding inclination was first documented. The post-test CT image analysis shows the crack patterns via 2-D image reconstructions, an index of stimulated fracture density is defined to represent the anisotropic failure mode of shale. What is more, the most striking finding is that the AE monitoring results are in good agreement with the CT analysis. The structural difference in the shale sample is the controlling factor resulting in the anisotropy of AE patterns. The pronounced bedding structure in the shale formation results in an anisotropy of elasticity, strength and AE information from which the changes in strength dominate the entire failure pattern of the shale samples.

  14. Energy levels of 4f3 in the Nd3+ free ion from emission spectra

    International Nuclear Information System (INIS)

    Wyart, Jean-Francois; Meftah, Ali; Bachelier, Annik; Sinzelle, Jocelyne; Tchang-Brillet, Wan-Ue Lydia; Champion, Norbert; Spector, Nissan; Sugar, Jack

    2006-01-01

    The emission spectrum of neodymium produced by vacuum spark sources was observed in the vacuum ultraviolet on two normal-incidence spectrographs. In an initial result, more than 550 lines have been identified as transitions from 85 4f 2 5d levels to 37 levels of the 4f 3 ground configuration in the free ion Nd 3+ . The levels 4f 34 F 3/2 and 4 I 11/2 , responsible for the well-known 1064 nm laser line, have respective positions of 11 698.57 ±0.1 cm -1 and 1897.07 ±0.1 cm -1 above the ground level 4 I 9/2 . The newly found levels of 4f 3 constitute the first isolated 4f N configuration (N > 2) and therefore enable checks of effective parameters that represent far configuration interaction. Slater parameters F k (4f, 4f) derived from Nd 3+ :LaCl 3 are 3% to 5% smaller than in the free ion. (letter to the editor)

  15. Development of Acoustic Model-Based Iterative Reconstruction Technique for Thick-Concrete Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Almansouri, Hani [Purdue University; Clayton, Dwight A [ORNL; Kisner, Roger A [ORNL; Polsky, Yarom [ORNL; Bouman, Charlie [Purdue University; Santos-Villalobos, Hector J [ORNL

    2015-01-01

    Ultrasound signals have been used extensively for non-destructive evaluation (NDE). However, typical reconstruction techniques, such as the synthetic aperture focusing technique (SAFT), are limited to quasi-homogenous thin media. New ultrasonic systems and reconstruction algorithms are in need for one-sided NDE of non-homogenous thick objects. An application example space is imaging of reinforced concrete structures for commercial nuclear power plants (NPPs). These structures provide important foundation, support, shielding, and containment functions. Identification and management of aging and degradation of concrete structures is fundamental to the proposed long-term operation of NPPs. Another example is geothermal and oil/gas production wells. These multi-layered structures are composed of steel, cement, and several types of soil and rocks. Ultrasound systems with greater penetration range and image quality will allow for better monitoring of the well s health and prediction of high-pressure hydraulic fracturing of the rock. These application challenges need to be addressed with an integrated imaging approach, where the application, hardware, and reconstruction software are highly integrated and optimized. Therefore, we are developing an ultrasonic system with Model-Based Iterative Reconstruction (MBIR) as the image reconstruction backbone. As the first implementation of MBIR for ultrasonic signals, this paper document the first implementation of the algorithm and show reconstruction results for synthetically generated data.

  16. Development of Acoustic Model-Based Iterative Reconstruction Technique for Thick-Concrete Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Almansouri, Hani [Purdue University; Clayton, Dwight A [ORNL; Kisner, Roger A [ORNL; Polsky, Yarom [ORNL; Bouman, Charlie [Purdue University; Santos-Villalobos, Hector J [ORNL

    2016-01-01

    Ultrasound signals have been used extensively for non-destructive evaluation (NDE). However, typical reconstruction techniques, such as the synthetic aperture focusing technique (SAFT), are limited to quasi-homogenous thin media. New ultrasonic systems and reconstruction algorithms are in need for one-sided NDE of non-homogenous thick objects. An application example space is imaging of reinforced concrete structures for commercial nuclear power plants (NPPs). These structures provide important foundation, support, shielding, and containment functions. Identification and management of aging and degradation of concrete structures is fundamental to the proposed long-term operation of NPPs. Another example is geothermal and oil/gas production wells. These multi-layered structures are composed of steel, cement, and several types of soil and rocks. Ultrasound systems with greater penetration range and image quality will allow for better monitoring of the well's health and prediction of high-pressure hydraulic fracturing of the rock. These application challenges need to be addressed with an integrated imaging approach, where the application, hardware, and reconstruction software are highly integrated and optimized. Therefore, we are developing an ultrasonic system with Model-Based Iterative Reconstruction (MBIR) as the image reconstruction backbone. As the first implementation of MBIR for ultrasonic signals, this paper document the first implementation of the algorithm and show reconstruction results for synthetically generated data.

  17. Development of acoustic model-based iterative reconstruction technique for thick-concrete imaging

    Science.gov (United States)

    Almansouri, Hani; Clayton, Dwight; Kisner, Roger; Polsky, Yarom; Bouman, Charles; Santos-Villalobos, Hector

    2016-02-01

    Ultrasound signals have been used extensively for non-destructive evaluation (NDE). However, typical reconstruction techniques, such as the synthetic aperture focusing technique (SAFT), are limited to quasi-homogenous thin media. New ultrasonic systems and reconstruction algorithms are in need for one-sided NDE of non-homogenous thick objects. An application example space is imaging of reinforced concrete structures for commercial nuclear power plants (NPPs). These structures provide important foundation, support, shielding, and containment functions. Identification and management of aging and degradation of concrete structures is fundamental to the proposed long-term operation of NPPs. Another example is geothermal and oil/gas production wells. These multi-layered structures are composed of steel, cement, and several types of soil and rocks. Ultrasound systems with greater penetration range and image quality will allow for better monitoring of the well's health and prediction of high-pressure hydraulic fracturing of the rock. These application challenges need to be addressed with an integrated imaging approach, where the application, hardware, and reconstruction software are highly integrated and optimized. Therefore, we are developing an ultrasonic system with Model-Based Iterative Reconstruction (MBIR) as the image reconstruction backbone. As the first implementation of MBIR for ultrasonic signals, this paper document the first implementation of the algorithm and show reconstruction results for synthetically generated data.1

  18. Improving the resolution of three-dimensional acoustic imaging with planar phased arrays

    DEFF Research Database (Denmark)

    Xenaki, Angeliki; Jacobsen, Finn; Fernandez Grande, Efren

    2012-01-01

    a transformation of coordinates that tends to make the response to a point source, the point spread function, more shift invariant. The result is a significant improvement in sound source imaging in the transformed coordinate system. However, the inverse transformation to Cartesian coordinates introduces range...

  19. Virtual touch tissue quantification of acoustic radiation force impulse: a new ultrasound elastic imaging in the diagnosis of thyroid nodules.

    Directory of Open Access Journals (Sweden)

    Yi-Feng Zhang

    Full Text Available OBJECTIVE: Virtual touch tissue quantification (VTQ of acoustic radiation force impulse (ARFI is a new quantitative technique to measure tissue stiffness. The study was aimed to assess the usefulness of VTQ in the diagnosis of thyroid nodules. METHODS: 173 pathologically proven thyroid nodules in 142 patients were included and all were examined by conventional ultrasound (US, conventional elasticity imaging (EI and VTQ of ARFI. The tissue stiffness for VTQ was expressed as shear wave velocity (SWV (m/s. Receiver-operating characteristic curve (ROC analyses were performed to assess the diagnostic performance. Intra- and inter-observer reproducibility of VTQ measurement was assessed. RESULTS: The SWVs of benign and malignant thyroid nodules were 2.34±1.17 m/s (range: 0.61-9.00 m/s and 4.82±2.53 m/s (range: 2.32-9.00 m/s respectively (P20 mm and lowest for those ≤10 mm. The correlation coefficients were 0.904 for intraobserver measurement and 0.864 for interobserver measurement. CONCLUSIONS: VTQ of ARFI provides quantitative and reproducible information about the tissue stiffness, which is useful for the differentiation between benign and malignant thyroid nodules. The diagnostic performance of VTQ is higher than that of conventional EI.

  20. Simulation of 4f-5d transitions of Yb2+ in potassium and sodium halides

    International Nuclear Information System (INIS)

    Duan Changkui; Tanner, P A

    2008-01-01

    The free ion energy level parameters of Yb 2+ are obtained by fitting the 4f 13 5d Yb 2+ free ion energy levels. A model is proposed for scaling these parameters so that they are appropriate for Yb 2+ in crystals. Treating the scaling factor, the barycenter energy E exc of the 4f 13 5d configuration, and the crystal-field splitting parameter B 4 (dd) as free parameters and adopting the 4f crystal-field parameters of the 4f 13 configuration Yb 3+ ion in other hosts with the same ligands, the absorption spectra of Yb 2+ in MX (M = K, Na; X = F, Cl, Br, I) hosts are well simulated. A model is proposed for taking the effect of charge compensation into account and this shows that the inclusion of charge compensation effects does not significantly alter the calculated electronic absorption spectra but may considerably change the dynamics of the system

  1. Electron attachment properties of c-C4F8O\

    Czech Academy of Sciences Publication Activity Database

    Chachereau, A.; Fedor, Juraj; Janečková, R.; Kočišek, Jaroslav; Rabie, M.; Franck, C. M.

    2016-01-01

    Roč. 49, č. 37 (2016), 375201 ISSN 0022-3727 Institutional support: RVO:61388955 Keywords : C4F8O * octafluorotetrahydrofuran * attachment cross section Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.588, year: 2016

  2. Complexation and extraction of series 4f, 5f and 4d ions by dialkyldithiophosphoric acids

    International Nuclear Information System (INIS)

    Fitoussi, Richard.

    1982-04-01

    A study was carried out on the complexing and extracting properties of various dialkyldithiophosphoric acids towards ions of the 4f, 5f and 4d series. Sulphurated donors complex and extract ions of the 4f and 5f series less strongly than their oxygenated homologues. However the affinity of trivalent actinide ions for dialkythiophosphate ions is shown to be greater than that of lanthanides. The conditions of ruthenium extraction from nitric acid are defined [fr

  3. Targeting the eIF4F translation initiation complex: a critical nexus for cancer development.

    Science.gov (United States)

    Pelletier, Jerry; Graff, Jeremy; Ruggero, Davide; Sonenberg, Nahum

    2015-01-15

    Elevated protein synthesis is an important feature of many cancer cells and often arises as a consequence of increased signaling flux channeled to eukaryotic initiation factor 4F (eIF4F), the key regulator of the mRNA-ribosome recruitment phase of translation initiation. In many cellular and preclinical models of cancer, eIF4F deregulation results in changes in translational efficiency of specific mRNA classes. Importantly, many of these mRNAs code for proteins that potently regulate critical cellular processes, such as cell growth and proliferation, enhanced cell survival and cell migration that ultimately impinge on several hallmarks of cancer, including increased angiogenesis, deregulated growth control, enhanced cellular survival, epithelial-to-mesenchymal transition, invasion, and metastasis. By being positioned as the molecular nexus downstream of key oncogenic signaling pathways (e.g., Ras, PI3K/AKT/TOR, and MYC), eIF4F serves as a direct link between important steps in cancer development and translation initiation. Identification of mRNAs particularly responsive to elevated eIF4F activity that typifies tumorigenesis underscores the critical role of eIF4F in cancer and raises the exciting possibility of developing new-in-class small molecules targeting translation initiation as antineoplastic agents. ©2014 American Association for Cancer Research.

  4. CYP4F18-Deficient Neutrophils Exhibit Increased Chemotaxis to Complement Component C5a

    Directory of Open Access Journals (Sweden)

    Rachel Vaivoda

    2015-01-01

    Full Text Available CYP4Fs were first identified as enzymes that catalyze hydroxylation of leukotriene B4 (LTB4. CYP4F18 has an unusual expression in neutrophils and was predicted to play a role in regulating LTB4-dependent inflammation. We compared chemotaxis of wild-type and Cyp4f18 knockout neutrophils using an in vitro assay. There was no significant difference in the chemotactic response to LTB4, but the response to complement component C5a increased 1.9–2.25-fold in knockout cells compared to wild-type (P < 0.01. This increase was still observed when neutrophils were treated with inhibitors of eicosanoid synthesis. There were no changes in expression of other CYP4 enzymes in knockout neutrophils that might compensate for loss of CYP4F18 or lead to differences in activity. A mouse model of dextran sodium sulfate colitis was used to investigate the consequences of increased C5a-dependent chemotaxis in vivo, but there was no significant difference in weight loss, disease activity, or colonic tissue myeloperoxidase between wild-type and Cyp4f18 knockout mice. This study demonstrates the limitations of inferring CYP4F function based on an ability to use LTB4 as a substrate, points to expanding roles for CYP4F enzymes in immune regulation, and underscores the in vivo challenges of CYP knockout studies.

  5. Communication Acoustics

    DEFF Research Database (Denmark)

    Blauert, Jens

    Communication Acoustics deals with the fundamentals of those areas of acoustics which are related to modern communication technologies. Due to the advent of digital signal processing and recording in acoustics, these areas have enjoyed an enormous upswing during the last 4 decades. The book...... the book a source of valuable information for those who want to improve or refresh their knowledge in the field of communication acoustics - and to work their way deeper into it. Due to its interdisciplinary character Communication Acoustics is bound to attract readers from many different areas, such as......: acoustics, cognitive science, speech science, and communication technology....

  6. Acoustic field modulation in regenerators

    Science.gov (United States)

    Hu, J. Y.; Wang, W.; Luo, E. C.; Chen, Y. Y.

    2016-12-01

    The regenerator is a key component that transfers energy between heat and work. The conversion efficiency is significantly influenced by the acoustic field in the regenerator. Much effort has been spent to quantitatively determine this influence, but few comprehensive experimental verifications have been performed because of difficulties in modulating and measuring the acoustic field. In this paper, a method requiring two compressors is introduced and theoretically investigated that achieves acoustic field modulation in the regenerator. One compressor outputs the acoustic power for the regenerator; the other acts as a phase shifter. A RC load dissipates the acoustic power out of both the regenerator and the latter compressor. The acoustic field can be modulated by adjusting the current in the two compressors and opening the RC load. The acoustic field is measured with pressure sensors instead of flow-field imaging equipment, thereby greatly simplifying the experiment.

  7. Controlling sound with acoustic metamaterials

    DEFF Research Database (Denmark)

    Cummer, Steven A. ; Christensen, Johan; Alù, Andrea

    2016-01-01

    Acoustic metamaterials can manipulate and control sound waves in ways that are not possible in conventional materials. Metamaterials with zero, or even negative, refractive index for sound offer new possibilities for acoustic imaging and for the control of sound at subwavelength scales....... The combination of transformation acoustics theory and highly anisotropic acoustic metamaterials enables precise control over the deformation of sound fields, which can be used, for example, to hide or cloak objects from incident acoustic energy. Active acoustic metamaterials use external control to create......-scale metamaterial structures and converting laboratory experiments into useful devices. In this Review, we outline the designs and properties of materials with unusual acoustic parameters (for example, negative refractive index), discuss examples of extreme manipulation of sound and, finally, provide an overview...

  8. Acoustic Neuroma

    Science.gov (United States)

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

  9. Model simulations of line-of-sight effects in airglow imaging of acoustic and fast gravity waves from ground and space

    Science.gov (United States)

    Aguilar Guerrero, J.; Snively, J. B.

    2017-12-01

    Acoustic waves (AWs) have been predicted to be detectable by imaging systems for the OH airglow layer [Snively, GRL, 40, 2013], and have been identified in spectrometer data [Pilger et al., JASP, 104, 2013]. AWs are weak in the mesopause region, but can attain large amplitudes in the F region [Garcia et al., GRL, 40, 2013] and have local impacts on the thermosphere and ionosphere. Similarly, fast GWs, with phase speeds over 100 m/s, may propagate to the thermosphere and impart significant local body forcing [Vadas and Fritts, JASTP, 66, 2004]. Both have been clearly identified in ionospheric total electron content (TEC), such as following the 2013 Moore, OK, EF5 tornado [Nishioka et al., GRL, 40, 2013] and following the 2011 Tohoku-Oki tsunami [e.g., Galvan et al., RS, 47, 2012, and references therein], but AWs have yet to be unambiguously imaged in MLT data and fast GWs have low amplitudes near the threshold of detection; nevertheless, recent imaging systems have sufficient spatial and temporal resolution and sensitivity to detect both AWs and fast GWs with short periods [e.g., Pautet et al., AO, 53, 2014]. The associated detectability challenges are related to the transient nature of their signatures and to systematic challenges due to line-of-sight (LOS) effects such as enhancements and cancelations due to integration along aligned or oblique wavefronts and geometric intensity enhancements. We employ a simulated airglow imager framework that incorporates 2D and 3D emission rate data and performs the necessary LOS integrations for synthetic imaging from ground- and space-based platforms to assess relative intensity and temperature perturbations. We simulate acoustic and fast gravity wave perturbations to the hydroxyl layer from a nonlinear, compressible model [e.g., Snively, 2013] for different idealized and realistic test cases. The results show clear signal enhancements when acoustic waves are imaged off-zenith or off-nadir and the temporal evolution of these

  10. Acoustic radiation force impulse (ARFI) ultrasound imaging of pancreatic cystic lesions

    Energy Technology Data Exchange (ETDEWEB)

    D' Onofrio, M., E-mail: mirko.donofrio@univr.it [Department of Radiology, University Hospital G.B. Rossi, Piazzale L.A. Scuro 10, University of Verona, 37134 Verona (Italy); Gallotti, A. [Department of Radiology, University Hospital G.B. Rossi, Piazzale L.A. Scuro 10, University of Verona, 37134 Verona (Italy); Salvia, R. [Department of Surgery, University Hospital G.B. Rossi, Piazzale L.A. Scuro 10, University of Verona, 37134 Verona (Italy); Capelli, P. [Department of Pathology, University Hospital G.B. Rossi, Piazzale L.A. Scuro 10, University of Verona, 37134 Verona (Italy); Mucelli, R. Pozzi [Department of Radiology, University Hospital G.B. Rossi, Piazzale L.A. Scuro 10, University of Verona, 37134 Verona (Italy)

    2011-11-15

    Purpose: To evaluate the ARFI ultrasound imaging with Virtual Touch tissue quantification in studying pancreatic cystic lesions, compared with phantom fluid models. Materials and methods: Different phantom fluids at different viscosity or density (water, iodinate contrast agent, and oil) were evaluated by two independent operators. From September to December 2008, 23 pancreatic cystic lesions were prospectively studied. All lesions were pathologically confirmed. Results: Non-numerical values on water and numerical values on other phantoms were obtained. Inter-observer evaluation revealed a perfect correlation (rs = 1.00; p < 0.0001) between all measurements achieved by both operators per each balloon and fluid. Among the pancreatic cystic lesions, 14 mucinous cystadenomas, 4 pseudocysts, 3 intraductal papillary-mucinous neoplasms and 2 serous cystadenomas were studied. The values obtained ranged from XXXX/0-4,85 m/s in mucinous cystadenomas, from XXXX/0-3,11 m/s in pseudocysts, from XXXX/0-4,57 m/s in intraductal papillary-mucinous neoplasms. In serous cystadenomas all values measured were XXXX/0 m/s. Diagnostic accuracy in benign and non-benign differentiation of pancreatic cystic lesions was 78%. Conclusions: Virtual Touch tissue quantification can be applied in the analysis of fluids and is potentially able to differentiate more complex (mucinous) from simple (serous) content in studying pancreatic cystic lesions.

  11. Acoustic radiation force impulse (ARFI) ultrasound imaging of pancreatic cystic lesions

    International Nuclear Information System (INIS)

    D'Onofrio, M.; Gallotti, A.; Salvia, R.; Capelli, P.; Mucelli, R. Pozzi

    2011-01-01

    Purpose: To evaluate the ARFI ultrasound imaging with Virtual Touch tissue quantification in studying pancreatic cystic lesions, compared with phantom fluid models. Materials and methods: Different phantom fluids at different viscosity or density (water, iodinate contrast agent, and oil) were evaluated by two independent operators. From September to December 2008, 23 pancreatic cystic lesions were prospectively studied. All lesions were pathologically confirmed. Results: Non-numerical values on water and numerical values on other phantoms were obtained. Inter-observer evaluation revealed a perfect correlation (rs = 1.00; p < 0.0001) between all measurements achieved by both operators per each balloon and fluid. Among the pancreatic cystic lesions, 14 mucinous cystadenomas, 4 pseudocysts, 3 intraductal papillary-mucinous neoplasms and 2 serous cystadenomas were studied. The values obtained ranged from XXXX/0-4,85 m/s in mucinous cystadenomas, from XXXX/0-3,11 m/s in pseudocysts, from XXXX/0-4,57 m/s in intraductal papillary-mucinous neoplasms. In serous cystadenomas all values measured were XXXX/0 m/s. Diagnostic accuracy in benign and non-benign differentiation of pancreatic cystic lesions was 78%. Conclusions: Virtual Touch tissue quantification can be applied in the analysis of fluids and is potentially able to differentiate more complex (mucinous) from simple (serous) content in studying pancreatic cystic lesions.

  12. Imaging of microwave-induced acoustic fields in LiNbO{sub 3} by high-performance Brillouin microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Vincent, B [Lab. Europeen de Recherche Univ.: Saarland-Lorraine, Univ. des Saarlandes, D-66041 Saarbruecken (Germany)]|[Lab. de Physique des Milieux Ionises et Applications, CNRS-UMR 7040, Univ. H. Poincare, Nancy I, F-54506 (France); Krueger, J K [Lab. Europeen de Recherche Univ.: Saarland-Lorraine, Univ. des Saarlandes, D-66041 Saarbruecken (Germany)]|[Fachrichtung 7.2, Experimentalphysik, Univ. des Saarlandes, Bau 38, D-66041 Saarbruecken (Germany); Elmazria, O [Laboratoire Europeen de Recherche Universitaire: Saarland-Lorraine, Universitaet des Saarlandes, D-66041 Saarbruecken (Germany)]|[Laboratoire de Physique des Milieux Ionises et Applications, CNRS-UMR 7040, Universite H. Poincare, Nancy I, F-54506 (France); Bouvot, L [Laboratoire Europeen de Recherche Universitaire: Saarland-Lorraine, Universitaet des Saarlandes, D-66041 Saarbruecken (Germany)]|[Laboratoire de Physique des Milieux Ionises et Applications, CNRS-UMR 7040, Universite H. Poincare, Nancy I, F-54506 (France); Mainka, J [Laboratoire Europeen de Recherche Universitaire: Saarland-Lorraine, Universitaet des Saarlandes, D-66041 Saarbruecken (Germany)]|[Fachrichtung 7.2, Experimentalphysik, Universitaet des Saarlandes, Bau 38, D-66041 Saarbruecken (Germany); Sanctuary, R [Laboratoire Europeen de Recherche Universitaire: Saarland-Lorraine, Universitaet des Saarlandes, D-66041 Saarbruecken (Germany)]|[Laboratoire de Physique des Materiaux, Campus Luxembourg-Limpertsberg, L-1511 Luxembourg (Luxembourg); Rouxel, D [Lab. Europeen de Recherche Univ.: Saarland-Lorraine, Univ. des Saarlandes, D-66041 Saarbruecken (Germany)]|[Lab. de Physique des Milieux Ionises et Applications, CNRS-UMR 7040, Univ. H. Poincare, Nancy I, F-54506 (France); Alnot, P [Lab. Europeen de Recherche Univ.: Saarland-Lorraine, Univ. des Saarlandes, D-66041 Saarbruecken (Germany)]|[Lab. de Physique des Milieux Ionises et Applications, CNRS-UMR 7040, Univ. H. Poincare, Nancy I, F-54506 (France)

    2005-06-21

    High performance Brillouin microscopy (BM) has been used to characterize the spatial distribution of piezoelectrically induced acoustic fields excited at microwave frequencies in a LiNbO{sub 3} single crystal. It is demonstrated that under suitable conditions BM is able to detect microwave-induced bulk as well as surface acoustic waves. Brillouin spectroscopy is able to probe sound wave intensities of induced phonons, which are as small as those of thermal phonons.

  13. Age-related changes in liver, kidney, and spleen stiffness in healthy children measured with acoustic radiation force impulse imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Mi-Jung, E-mail: mjl1213@yuhs.ac [Department of Radiology and Research Institute of Radiological Science, Severance Children' s Hospital, Yonsei University, College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752 (Korea, Republic of); Kim, Myung-Joon, E-mail: mjkim@yuhs.ac [Department of Radiology and Research Institute of Radiological Science, Severance Children' s Hospital, Yonsei University, College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752 (Korea, Republic of); Han, Kyung Hwa, E-mail: khhan@yuhs.ac [Biostatistics Collaboration Unit, Yonsei University, College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752 (Korea, Republic of); Yoon, Choon Sik, E-mail: yooncs58@yuhs.ac [Department of Radiology, Gangnam Severance Hospital, Yonsei University, College of Medicine, 211 Unjoo-ro, Gangnam-gu, Seoul (Korea, Republic of)

    2013-06-15

    Objectives: To evaluate the feasibility and age-related changes of shear wave velocity (SWV) in normal livers, kidneys, and spleens of children using acoustic radiation force impulse (ARFI) imaging. Materials and methods: Healthy pediatric volunteers prospectively underwent abdominal ultrasonography and ARFI. The subjects were divided into three groups according to age: group 1: <5 years old; group 2: 5–10 years old; and group 3: >10 years old. The SWV was measured using a 4–9 MHz linear probe for group 1 and a 1–4 MHz convex probe for groups 2 and 3. Three valid SWV measurements were acquired for each organ. Results: Two hundred and two children (92 male, 110 female) with an average age of 8.1 years (±4.7) were included in this study and had a successful measurement rate of 97% (196/202). The mean SWVs were 1.12 m/s for the liver, 2.19 m/s for the right kidney, 2.33 m/s for the left kidney, and 2.25 m/s for the spleen. The SWVs for the right and left kidneys, and the spleen showed age-related changes in all children (p < 0.001). And the SWVs for the kidneys increased with age in group 1, and those for the liver changed with age in group 3. Conclusions: ARFI measurements are feasible for solid abdominal organs in children using high or low frequency probes. The mean ARFI SWV for the kidneys increased according to age in children less than 5 years of age and in the liver, it changed with age in children over 10.

  14. Acoustic radiation force impulse imaging with Virtual Touch™ tissue quantification: mean shear wave velocity of malignant and benign breast masses.

    Science.gov (United States)

    Wojcinski, Sebastian; Brandhorst, Kathrin; Sadigh, Gelareh; Hillemanns, Peter; Degenhardt, Friedrich

    2013-01-01

    Acoustic radiation force impulse imaging (ARFI) with Virtual Touch™ tissue quantification (VTTQ) enables the determination of shear wave velocity (SWV) in meters per second (m/s). The aim of our study was to describe the mean SWV in normal breast tissue and various breast masses. We performed measurements of SWV with ARFI VTTQ in 145 breast masses (57 malignant, 88 benign) and in the adjacent breast parenchyma and adipose tissue. The mean SWV as well as the rate of successful measurements were analyzed. The difference between adipose tissue and parenchyma was statistically significant (3.05 versus 3.65 m/s) (P breast masses, numerous measurements exceeded the upper limit of possible measurement (≥9.10 m/s, indicated as "X.XX m/s"). Nevertheless, the difference between the malignant and benign masses was statistically significant (8.38 ± 1.99 m/s versus 5.39 ± 2.95 m/s) (P < 0.001). The best diagnostic accuracy (75.9%) was achieved when the cutoff point for malignancy was set to 9.10 m/s in ARFI VTTQ. This implies that the SWV was regarded as suspicious when the upper limit of possible measurement was exceeded and the machine returned the value X.XX m/s. In conclusion, ARFI VTTQ is a feasible method for measurement of SWV in a region of interest. Furthermore, we propose the event of a highly elevated SWV as a significant criterion for malignancy. However, the method is technically not yet fully developed, and the problem of unsuccessful measurements must still be solved.

  15. Feasibility of High Frequency Acoustic Imaging for Inspection of Containments: Phase II

    International Nuclear Information System (INIS)

    Rudzinsky, J.; Bondaryk, J.; Conti, M.

    1999-01-01

    The nuclear power industry is concerned with corrosive thinning of portions of the metallic pressure boundary, particularly in areas that are not directly accessible for inspection. This study investigated the feasibility of detecting these thickness degradations using ultrasonic imaging. A commercial ultrasonic system was used to carry out several full-scale, controlled laboratory experiments. Measurements of 0.5 MHz shear wave levels propagated in 25-mm-thick steel plate embedded in concrete showed 1.4-1.6 dB of signal loss for each centimeter of two-way travel in the steel plate (compared to previous numerical predictions of 3-4 dB), and 1.3 dB of signal loss per centimeter of two-way travel in steel plates embedded in concrete prior to setting of the concrete (i.e., plastic). Negligible losses were measured in plates with a decoupling treatment applied between the steel and concrete to simulate the unbonded portions of the pressure boundary. Scattered signals from straight slots of different size and shape were investigated. The return from a 4-mm-deep rectangular slots exhibited levels 23 dB down relative to incidence and 4-6 dB higher than those obtained from both ''v'' shaped and rounded slots of similar depth. The system displayed an input/output dynamic range of 125 dB and measurement variability less than 1-2dB. Based on these results, a 4-mm-deep, rounded degradation embedded 30 cm in concrete has expected returns of -73dB relative to the input and should therefore be detectable. Results of this and a prior study indicate that the technique has merit and should be developed more fully and demonstrated in the field

  16. Analysis of the lowest 4f-5g supermultiplet of Co II

    International Nuclear Information System (INIS)

    Pickering, J.C.

    1998-01-01

    The high resolution Fourier-transform emission spectrum from a cobalt-neon hollow cathode lamp has been studied in the region 9753-9997 A (10 000-10 250 cm -1 ). Of the 54 levels of the Co II 3d 7 ( 4 F)5g sub-configuration, 51 are found by means of 144 newly identified transitions to the levels of the 3d 7 ( 4 F)4f subconfiguration. These lines account for the majority of previously unclassified transitions in this spectral region. The accuracy of the energy levels is a few mK (1 mK = 0.001 cm -1 ). JK coupling is used to represent the 4f and 5g levels and the suitability of this is shown by applying the quadrupolic approximation. A classified linelist of the observed 4f-5g transitions is given with wavenumbers accurate to approximately 0.003 cm -1 for strong lines, observed intensities, and calculated oscillator strengths. (orig.)

  17. Determination of the clean 4f peak shape in XPS for plutonium metal

    Energy Technology Data Exchange (ETDEWEB)

    Morrall, P. [AWE, Aldermaston, Reading, Berkshire RG7 4PR (United Kingdom)], E-mail: peter.morrall@awe.co.uk; Roussel, P. [AWE, Aldermaston, Reading, Berkshire RG7 4PR (United Kingdom); Jolly, L.; Brevet, A.; Delaunay, F. [Commissariat a l' Energie Atomique, Centre de Valduc, 21120 Is-sur-Tille (France)

    2009-03-15

    Many of the interesting properties observed with plutonium are ascribed to the influence of 5f electrons, and to the degree of localisation observed within these electrons. Indeed, changes in 5f localisation are sensitively reflected in the final states observed in core-level photoemission measurements. However, when analysing the 4f manifold of elemental plutonium, it is essential to obtain spectra without the influence of oxidation, which can easily be misinterpreted as 5f localisation. The ideal method to extract elemental plutonium 4f spectra is to remove any influence of oxidation from the 'clean' plutonium data by careful measurement of the oxygen 1s region, and the subsequent subtraction of the unwanted oxide features. However, in order to achieve this objective it is essential to determine the relative sensitivity factor (RSF) for plutonium 4f and the precise shape of the 4f features from plutonium sesqui-oxide. In this paper, we report an experimental determination of the RSF for the plutonium 4f manifold using experimental data captured from two different Vacuum Generators spectrometers; an ESCALAB Mk II and an ESCALAB 220i.

  18. Acoustic radiation force impulse imaging with Virtual Touch™ tissue quantification: mean shear wave velocity of malignant and benign breast masses

    Directory of Open Access Journals (Sweden)

    Wojcinski S

    2013-09-01

    Full Text Available Sebastian Wojcinski,1 Kathrin Brandhorst,2 Gelareh Sadigh,3 Peter Hillemanns,1 Friedrich Degenhardt2 1Department of Obstetrics and Gynecology, Hannover Medical School, Hannover, Germany; 2Department of Obstetrics and Gynecology, Franziskus Hospital, Bielefeld, Germany; 3Department of Radiology, Emory University, Atlanta, GA, USA Abstract: Acoustic radiation force impulse imaging (ARFI with Virtual Touch™ tissue quantification (VTTQ enables the determination of shear wave velocity (SWV in meters per second (m/s. The aim of our study was to describe the mean SWV in normal breast tissue and various breast masses. We performed measurements of SWV with ARFI VTTQ in 145 breast masses (57 malignant, 88 benign and in the adjacent breast parenchyma and adipose tissue. The mean SWV as well as the rate of successful measurements were analyzed. The difference between adipose tissue and parenchyma was statistically significant (3.05 versus 3.65 m/s (P < 0.001. Focusing on breast masses, numerous measurements exceeded the upper limit of possible measurement (≥9.10 m/s, indicated as "X.XX m/s". Nevertheless, the difference between the malignant and benign masses was statistically significant (8.38 ± 1.99 m/s versus 5.39 ± 2.95 m/s (P < 0.001. The best diagnostic accuracy (75.9% was achieved when the cutoff point for malignancy was set to 9.10 m/s in ARFI VTTQ. This implies that the SWV was regarded as suspicious when the upper limit of possible measurement was exceeded and the machine returned the value X.XX m/s. In conclusion, ARFI VTTQ is a feasible method for measurement of SWV in a region of interest. Furthermore, we propose the event of a highly elevated SWV as a significant criterion for malignancy. However, the method is technically not yet fully developed, and the problem of unsuccessful measurements must still be solved. Keywords: ARFI VTTQ, elastography, ultrasound, breast imaging

  19. Pou4f2 knock-in Cre mouse: A multifaceted genetic tool for vision researchers.

    Science.gov (United States)

    Simmons, Aaron B; Bloomsburg, Samuel J; Billingslea, Samuel A; Merrill, Morgan M; Li, Shuai; Thomas, Marshall W; Fuerst, Peter G

    2016-01-01

    A transgenic mouse that expresses Cre recombinase under control of the Pou4f2-promoter (also referred to as Brn-3b and Brn-3.2) was characterized. Pou4f2 expression has been reported in a subset of retinal ganglion cells (RGCs) in the retina, in the midbrain, and in the germline. In this study, we characterize the expression pattern of this Cre-recombinase line and report its utility in targeted deletion, temporal deletion, RGC depletion, and germline targeting, which can be regulated by the sex of the Cre-carrying mouse. Pou4f2(Cre) was mapped by using a combination of PCR and sequencing of PCR products to better understand the construct and to locate where it was inserted within the Pou4f2 locus. Cre expression patterns were examined by crossing Pou4f2(Cre/+) mice to Cre reporter mice. Immunohistochemistry was used to further define the pattern of Cre expression and Cre-mediated recombination within the retina, brain, and other tissues. An internal ribosome entry site (IRES)-Cre cassette was inserted into the Pou4f2 gene disrupting normal gene function, as verified by the depletion of RGCs in mice homozygous for the insert. Pou4f2(Cre) expression was observed in the retina, brain, peripheral neurons, and male germ cells. Germline recombination was observed when the sire carried the Cre and the target for recombination. In all other breeding schemes, recombination was observed within subsets of cells within the retina, brain, intestines, heart, and gonads. In the retina, Cre efficiently targets recombination in neurons within the RGC layer (RGL), the inner nuclear layer (INL), and a small percentage of photoreceptors, activity that has not been previously reported. Unlike most other Cre lines active in the inner retina, recombination in Müller and other glia was not observed in mice carrying Pou4f2(Cre) . Within the visual centers of the brain, Cre targets recombination in about 15% of cells within the superchiasmatic nucleus, lateral geniculate nucleus, and

  20. Magnetic x-ray linear dichroism in resonant and non-resonant Gd 4f photoemission

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, S.; Gammon, W.J.; Pappas, D.P. [Virginia Commonwealth Univ., Richmond, VA (United States)] [and others

    1997-04-01

    The enhancement of the magnetic linear dichroism in resonant 4f photoemission (MLDRPE) is studied from a 50 monolayer film of Gd/Y(0001). The ALS at beamline 7.0.1 provided the source of linearly polarized x-rays used in this study. The polarized light was incident at an angle of 30 degrees relative to the film plane, and the sample magnetization was perpendicular to the photon polarization. The linear dichroism of the 4f core levels is measured as the photon energy is tuned through the 4d-4f resonance. The authors find that the MLDRPE asymmetry is strongest at the resonance. Near the threshold the asymmetry has several features which are out of phase with the fine structure of the total yield.

  1. Magnetic x-ray linear dichroism in resonant and non-resonant Gd 4f photoemission

    International Nuclear Information System (INIS)

    Mishra, S.; Gammon, W.J.; Pappas, D.P.

    1997-01-01

    The enhancement of the magnetic linear dichroism in resonant 4f photoemission (MLDRPE) is studied from a 50 monolayer film of Gd/Y(0001). The ALS at beamline 7.0.1 provided the source of linearly polarized x-rays used in this study. The polarized light was incident at an angle of 30 degrees relative to the film plane, and the sample magnetization was perpendicular to the photon polarization. The linear dichroism of the 4f core levels is measured as the photon energy is tuned through the 4d-4f resonance. The authors find that the MLDRPE asymmetry is strongest at the resonance. Near the threshold the asymmetry has several features which are out of phase with the fine structure of the total yield

  2. Acoustic emission linear pulse holography

    Science.gov (United States)

    Collins, H.D.; Busse, L.J.; Lemon, D.K.

    1983-10-25

    This device relates to the concept of and means for performing Acoustic Emission Linear Pulse Holography, which combines the advantages of linear holographic imaging and Acoustic Emission into a single non-destructive inspection system. This unique system produces a chronological, linear holographic image of a flaw by utilizing the acoustic energy emitted during crack growth. The innovation is the concept of utilizing the crack-generated acoustic emission energy to generate a chronological series of images of a growing crack by applying linear, pulse holographic processing to the acoustic emission data. The process is implemented by placing on a structure an array of piezoelectric sensors (typically 16 or 32 of them) near the defect location. A reference sensor is placed between the defect and the array.

  3. Synthesis and evaluation of 4-[F-18]fluoro thalidomide for the in vivo studies of angiogenesis

    International Nuclear Information System (INIS)

    Kim, D. H.; Choi, Y. S.; Jeong, K. H.; Lee, K. H.; Choi, Y.; Kim, B. T.

    2005-01-01

    Thalidomide has been recently rediscovered for its possible utility as an antitumor agent, although it was marketed as a sedative in the 1950s and later found to be a potent teratogen. In this study, therefore, F-18 labeled thalidomide was synthesized and evaluated for the in vivo studies of angiogenesis. 4-[F-18]Fluoro thalidomide ([F-18]1) was prepared by labeling of 4-trimethylammonium thalidomide triflate with TBA[F-18]F in DMSO (90 .deg. C, 10 min) and purified by HPLC. The triflate salt was prepared from 3-fluoro phthalic anhydride in 3 steps. [F-18]1 was incubated with HUVEC cells at 37 .deg. C for 15, 30, 60, and 120 min, respectively. Dynamic PET images of [F-18]1 was obtained in mice implanted with LLC cells. In vitro metabolism study of [F-18]1 was carried out using mouse, rabbit, or human liver microsomes in the presence of NADPH, and the metabolites obtained from the mouse liver microsomal incubation of 1 were analyzed using LC-MS. Radiochemical yield of [F-18]1 was 50-60%, and the specific activity was 42-120 GBq/imol. The HUVEC cell uptake of [F-18]1 increased with time (100% at 15 min and 241% at 120 min). PET images showed that the radioactivity was accumulated in the liver, the kidneys and the bladder of the mice, and brain uptake was shown from 40 min postinjection. However, there was low level of radioactivity uptake in tumor. [F-18]1 was not metabolized by mouse, rabbit, or human liver microsomes but was hydrolyzed significantly at physiological pH. The hydrolyzed product was further analyzed by LC-MS, showing a mass peak corresponding to that of 4-fluoro-N-(o-carboxybenzoyl)glutamic acid imide. This result suggests that [F-18]1 is easily hydrolyzed at physiological pH and thus may not be suitable for the in vivo studies of tumor angiogenesis at least in rodents, although it was reported that the hydrolysis product of thalidomide may be responsible for its angiogenesis activity in humans

  4. Contact hyperfine field of the 4p and 4f series elements (rare-earths)

    International Nuclear Information System (INIS)

    Doi, I.

    1973-01-01

    The Coulomb correlation effect in the description of the contact hyperfine magnetic structure was analysed. The hyperfine magnetic structure was calculated from the spin polarized Hartree-Fock formalism, using the free electron gas approximation to the exchange-correlation energy of the 4p series atoms and some atoms and ions of the 4f series. No one of the analysed approximations to the exchange-correlation energy describes satisfactorily the contact hyperfine magnetic structure of the 4p and 4f series elements, which were studied [pt

  5. Acoustic cloaking and transformation acoustics

    International Nuclear Information System (INIS)

    Chen Huanyang; Chan, C T

    2010-01-01

    In this review, we give a brief introduction to the application of the new technique of transformation acoustics, which draws on a correspondence between coordinate transformation and material properties. The technique is formulated for both acoustic waves and linear liquid surface waves. Some interesting conceptual devices can be designed for manipulating acoustic waves. For example, we can design acoustic cloaks that make an object invisible to acoustic waves, and the cloak can either encompass or lie outside the object to be concealed. Transformation acoustics, as an analog of transformation optics, can go beyond invisibility cloaking. As an illustration for manipulating linear liquid surface waves, we show that a liquid wave rotator can be designed and fabricated to rotate the wave front. The acoustic transformation media require acoustic materials which are anisotropic and inhomogeneous. Such materials are difficult to find in nature. However, composite materials with embedded sub-wavelength resonators can in principle be made and such 'acoustic metamaterials' can exhibit nearly arbitrary values of effective density and modulus tensors to satisfy the demanding material requirements in transformation acoustics. We introduce resonant sonic materials and Helmholtz resonators as examples of acoustic metamaterials that exhibit resonant behaviour in effective density and effective modulus. (topical review)

  6. Comparison of acoustic radiation force impulse imaging (ARFI) to liver biopsy histologic scores in the evaluation of chronic liver disease: A pilot study.

    Science.gov (United States)

    Haque, Mazhar; Robinson, Charlotte; Owen, David; Yoshida, Eric M; Harris, Alison

    2010-01-01

    Acoustic Radiation Force Impulse Imaging (ARFI) is a novel non invasive technique studying the localized mechanical properties of tissue by utilising short, high intensity acoustic pulses (shear wave pulses) to assess the mechanical response (tissue displacement), providing a measure of tissue elasticity. The aim of this study is to investigate the feasibility of ARFI imaging as a non-invasive method for the assessment of liver fibrosis compared to liver biopsy scores. A prospective blind comparison study of ARFI elastography (Virtual Touch Imaging., ACUSON S2000 Ultrasound Unit, Siemens, Mountain View CA) in a consecutive series of patients who underwent liver biopsy for assessment of fibrosis in chronic liver disease. ARFI shear-wave propagation velocity was measured in meters per second. Mean ARFI velocities were compared with both Batts-Ludwig (F0 to F4) and Modified Ishak scores (F0 to F4) for fibrosis in liver biopsy findings. Twenty-one patients with chronic liver disease (Hepatitis C (HCV) =16, Hepatitis B (HBV) = 1, both HCV and HBV = 1 Alcoholic liver disease (ALD) = 1, others = 2) underwent ARFI and liver biopsy on the same day. The Spearman correlation coefficients between the median values of the ARFI measurements and the histological fibrosis stage of the Modified Ishak score and Batts-Lud- (3) wig score were both highly significant (p shak score in chronic liver disease. It.s accuracy in prediction of severe fibrosis and cirrhosis is maximal in comparison with earlier stages.

  7. Imaging and quantitative data acquisition of biological cell walls with Atomic Force Microscopy and Scanning Acoustic Microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Tittmann, B. R. [Penn State; Xi, X. [Penn State

    2014-09-01

    This chapter demonstrates the feasibility of Atomic Force Microscopy (AFM) and High Frequency Scanning Acoustic Microscopy (HF-SAM) as tools to characterize biological tissues. Both the AFM and the SAM have shown to provide imaging (with different resolution) and quantitative elasticity measuring abilities. Plant cell walls with minimal disturbance and under conditions of their native state have been examined with these two kinds of microscopy. After descriptions of both the SAM and AFM, their special features and the typical sample preparation is discussed. The sample preparation is focused here on epidermal peels of onion scales and celery epidermis cells which were sectioned for the AFM to visualize the inner surface (closest to the plasma membrane) of the outer epidermal wall. The nm-wide cellulose microfibrils orientation and multilayer structure were clearly observed. The microfibril orientation and alignment tend to be more organized in older scales compared with younger scales. The onion epidermis cell wall was also used as a test analog to study cell wall elasticity by the AFM nanoindentation and the SAM V(z) feature. The novelty in this work was to demonstrate the capability of these two techniques to analyze isolated, single layered plant cell walls in their natural state. AFM nanoindentation was also used to probe the effects of Ethylenediaminetetraacetic acid (EDTA), and calcium ion treatment to modify pectin networks in cell walls. The results suggest a significant modulus increase in the calcium ion treatment and a slight decrease in EDTA treatment. To complement the AFM measurements, the HF-SAM was used to obtain the V(z) signatures of the onion epidermis. These measurements were focused on documenting the effect of pectinase enzyme treatment. The results indicate a significant change in the V(z) signature curves with time into the enzyme treatment. Thus AFM and HF-SAM open the door to a systematic nondestructive structure and mechanical property

  8. Substituting mouse transcription factor Pou4f2 with a sea urchin orthologue restores retinal ganglion cell development.

    Science.gov (United States)

    Mao, Chai-An; Agca, Cavit; Mocko-Strand, Julie A; Wang, Jing; Ullrich-Lüter, Esther; Pan, Ping; Wang, Steven W; Arnone, Maria Ina; Frishman, Laura J; Klein, William H

    2016-03-16

    Pou domain transcription factor Pou4f2 is essential for the development of retinal ganglion cells (RGCs) in the vertebrate retina. A distant orthologue of Pou4f2 exists in the genome of the sea urchin (class Echinoidea) Strongylocentrotus purpuratus (SpPou4f1/2), yet the photosensory structure of sea urchins is strikingly different from that of the mammalian retina. Sea urchins have no obvious eyes, but have photoreceptors clustered around their tube feet disc. The mechanisms that are associated with the development and function of photoreception in sea urchins are largely unexplored. As an initial approach to better understand the sea urchin photosensory structure and relate it to the mammalian retina, we asked whether SpPou4f1/2 could support RGC development in the absence of Pou4f2. To answer this question, we replaced genomic Pou4f2 with an SpPou4f1/2 cDNA. In Pou4f2-null mice, retinas expressing SpPou4f1/2 were outwardly identical to those of wild-type mice. SpPou4f1/2 retinas exhibited dark-adapted electroretinogram scotopic threshold responses, indicating functionally active RGCs. During retinal development, SpPou4f1/2 activated RGC-specific genes and in S. purpuratus, SpPou4f2 was expressed in photoreceptor cells of tube feet in a pattern distinct from Opsin4 and Pax6. Our results suggest that SpPou4f1/2 and Pou4f2 share conserved components of a gene network for photosensory development and they maintain their conserved intrinsic functions despite vast morphological differences in mouse and sea urchin photosensory structures. © 2016 The Authors.

  9. Topological Acoustics

    Science.gov (United States)

    Yang, Zhaoju; Gao, Fei; Shi, Xihang; Lin, Xiao; Gao, Zhen; Chong, Yidong; Zhang, Baile

    2015-03-01

    The manipulation of acoustic wave propagation in fluids has numerous applications, including some in everyday life. Acoustic technologies frequently develop in tandem with optics, using shared concepts such as waveguiding and metamedia. It is thus noteworthy that an entirely novel class of electromagnetic waves, known as "topological edge states," has recently been demonstrated. These are inspired by the electronic edge states occurring in topological insulators, and possess a striking and technologically promising property: the ability to travel in a single direction along a surface without backscattering, regardless of the existence of defects or disorder. Here, we develop an analogous theory of topological fluid acoustics, and propose a scheme for realizing topological edge states in an acoustic structure containing circulating fluids. The phenomenon of disorder-free one-way sound propagation, which does not occur in ordinary acoustic devices, may have novel applications for acoustic isolators, modulators, and transducers.

  10. Bulk plasma fragmentation in a C4F8 inductively coupled plasma: A hybrid modeling study

    International Nuclear Information System (INIS)

    Zhao, Shu-Xia; Zhang, Yu-Ru; Gao, Fei; Wang, You-Nian; Bogaerts, Annemie

    2015-01-01

    A hybrid model is used to investigate the fragmentation of C 4 F 8 inductive discharges. Indeed, the resulting reactive species are crucial for the optimization of the Si-based etching process, since they determine the mechanisms of fluorination, polymerization, and sputtering. In this paper, we present the dissociation degree, the density ratio of F vs. C x F y (i.e., fluorocarbon (fc) neutrals), the neutral vs. positive ion density ratio, details on the neutral and ion components, and fractions of various fc neutrals (or ions) in the total fc neutral (or ion) density in a C 4 F 8 inductively coupled plasma source, as well as the effect of pressure and power on these results. To analyze the fragmentation behavior, the electron density and temperature and electron energy probability function (EEPF) are investigated. Moreover, the main electron-impact generation sources for all considered neutrals and ions are determined from the complicated C 4 F 8 reaction set used in the model. The C 4 F 8 plasma fragmentation is explained, taking into account many factors, such as the EEPF characteristics, the dominance of primary and secondary processes, and the thresholds of dissociation and ionization. The simulation results are compared with experiments from literature, and reasonable agreement is obtained. Some discrepancies are observed, which can probably be attributed to the simplified polymer surface kinetics assumed in the model

  11. Extended analysis of the 5g→4f emissions in H2

    International Nuclear Information System (INIS)

    Chang, E.S.; Pulchtopek, S.; Eyler, E.E.

    1984-01-01

    An analysis starting from Hund's case d has been used to extend the work of Herzberg and Jungen on the 5g→4f emissions in H 2 . A simple analytical expression for the line intensities is presented that agrees with their calculations is about 1%. All of the experimentally observed lines have been accounted for by including higher vibrational levels in our calculations

  12. SUM-RULES FOR MAGNETIC DICHROISM IN RARE-EARTH 4F-PHOTOEMISSION

    NARCIS (Netherlands)

    THOLE, BT; VANDERLAAN, G

    1993-01-01

    We present new sum rules for magnetic dichroism in spin polarized photoemission from partly filled shells which give the expectation values of the orbital and spin magnetic moments and their correlations in the ground state. We apply this to the 4f photoemission of rare earths, where the

  13. Surface shift of the occupied and unoccupied 4f levels of the rare-earth metals

    Science.gov (United States)

    Aldén, M.; Johansson, B.; Skriver, H. L.

    1995-02-01

    The surface energy shifts of the occupied and unoccupied 4f levels for the lanthanide metals have been calculated from first principles by means of a Green's-function technique within the tight-binding linear muffin-tin orbitals method. We use the concept of complete screening to identify the occupied and unoccupied 4f energy level shifts as the surface segregation energy of a 4fn-1 and 4fn+1 impurity atom, respectively, in a 4fn host metal. The calculations include both initial- and final-state effects and give values that are considerably lower than those measured on polycrystalline samples as well as those found in previous initial-state model calculations. The present theory agrees well with very recent high-resolution, single-crystal film measurements for Gd, Tb, Dy, Ho, Er, Tm, and Lu. We furthermore utilize the unique possibility offered by the lanthanide metals to clarify the roles played by the initial and the different final states of the core-excitation process, permitted by the fact that the so-called initial-state effect is identical upon 4f removal and 4f addition. Surface energy and work function calculations are also reported.

  14. VHMPID RICH prototype using pressurized C{sub 4}F{sub 8}O radiator gas and VUV photon detector

    Energy Technology Data Exchange (ETDEWEB)

    Acconcia, T.V. [UNICAMP, University of Campinas, Campinas (Brazil); Agócs, A.G. [Wigner RCP of the HAS, Budapest (Hungary); Barile, F. [INFN Sezione di Bari and Universitá degli Studi di Bari, Dipartimento Interateneo di Fisica M. Merlin, Bari (Italy); Barnaföldi, G.G. [Wigner RCP of the HAS, Budapest (Hungary); Bellwied, R. [University of Houston, Houston (United States); Bencédi, G. [Wigner RCP of the HAS, Budapest (Hungary); Bencze, G., E-mail: Gyorgy.Bencze@cern.ch [Wigner RCP of the HAS, Budapest (Hungary); Berényi, D.; Boldizsár, L. [Wigner RCP of the HAS, Budapest (Hungary); Chattopadhyay, S. [Saha Institute, Kolkata (India); Chinellato, D.D. [University of Houston, Houston (United States); Cindolo, F. [University of Salerno, Salerno (Italy); Cossyleon, K. [Chicago State University, Chicago, IL (United States); Das, D.; Das, K.; Das-Bose, L. [Saha Institute, Kolkata (India); Dash, A.K. [UNICAMP, University of Campinas, Campinas (Brazil); D' Ambrosio, S. [University of Salerno, Salerno (Italy); De Cataldo, G. [INFN Sezione di Bari and Universitá degli Studi di Bari, Dipartimento Interateneo di Fisica M. Merlin, Bari (Italy); De Pasquale, S. [University of Salerno, Salerno (Italy); and others

    2014-12-11

    A small-size prototype of a new Ring Imaging Cherenkov (RICH) detector using for the first time pressurized C4F8O radiator gas and a photon detector consisting of MWPC equipped with a CsI photocathode has been built and tested at the PS accelerator at CERN. It contained all the functional elements of the detector proposed as Very High Momentum Particle Identification (VHMPID) upgrade for the ALICE experiment at LHC to provide charged hadron track-by-track identification in the momentum range starting from 5 potentially up to 25 GeV/c. In the paper the equipment and its elements are described and some characteristic test results are shown.

  15. Acoustic textiles

    CERN Document Server

    Nayak, Rajkishore

    2016-01-01

    This book highlights the manufacturing and applications of acoustic textiles in various industries. It also includes examples from different industries in which acoustic textiles can be used to absorb noise and help reduce the impact of noise at the workplace. Given the importance of noise reduction in the working environment in several industries, the book offers a valuable guide for companies, educators and researchers involved with acoustic materials.

  16. Lanthanide 4f-electron binding energies and the nephelauxetic effect in wide band gap compounds

    International Nuclear Information System (INIS)

    Dorenbos, Pieter

    2013-01-01

    Employing data from luminescence spectroscopy, the inter 4f-electron Coulomb repulsion energy U(6, A) in Eu 2+/3+ impurities together with the 5d-centroid energy shift ϵ c (1,3+,A) in Ce 3+ impurities in 40 different fluoride, chloride, bromide, iodide, oxide, sulfide, and nitride compounds has been determined. This work demonstrates that the chemical environment A affects the two energies in a similar fashion; a fashion that follows the anion nephelauxetic sequence F, O, Cl, Br, N, I, S, Se. One may then calculate U(6, A) from well established and accurate ϵ c (1,3+,A) values which are then used as input to the chemical shift model proposed in Dorenbos (2012) [19]. As output it provides the chemical shift of 4f-electron binding energy and therewith the 4f-electron binding energy relative to the vacuum energy. In addition this method provides a tool to routinely establish the binding energy of electrons at the top of the valence band (work function) and the bottom of the conduction band (electron affinity) throughout the entire family of inorganic compounds. How the electronic structure of the compound and lanthanide impurities therein change with type of compound and type of lanthanide is demonstrated. -- Highlights: ► A relationship between 5d centroid shift and 4f-electron Coulomb repulsion energy is established. ► Information on the absolute 4f-electron binding energy of lanthanides in 40 compounds is provided. ► A new tool to determine absolute binding energies of electrons in valence and conduction bands is demonstrated

  17. Transintestinal transport of the anti-inflammatory drug 4F and the modulation of transintestinal cholesterol efflux[S

    Science.gov (United States)

    Meriwether, David; Sulaiman, Dawoud; Wagner, Alan; Grijalva, Victor; Kaji, Izumi; Williams, Kevin J.; Yu, Liqing; Fogelman, Spencer; Volpe, Carmen; Bensinger, Steven J.; Anantharamaiah, G. M.; Shechter, Ishaiahu; Fogelman, Alan M.; Reddy, Srinivasa T.

    2016-01-01

    The site and mechanism of action of the apoA-I mimetic peptide 4F are incompletely understood. Transintestinal cholesterol efflux (TICE) is a process involved in the clearance of excess cholesterol from the body. While TICE is responsible for at least 30% of the clearance of neutral sterols from the circulation into the intestinal lumen, few pharmacological agents have been identified that modulate this pathway. We show first that circulating 4F selectively targets the small intestine (SI) and that it is predominantly transported into the intestinal lumen. This transport of 4F into the SI lumen is transintestinal in nature, and it is modulated by TICE. We also show that circulating 4F increases reverse cholesterol transport from macrophages and cholesterol efflux from lipoproteins via the TICE pathway. We identify the cause of this modulation of TICE either as 4F being a cholesterol acceptor with respect to enterocytes, from which 4F enhances cholesterol efflux, or as 4F being an intestinal chaperone with respect to TICE. Our results assign a novel role for 4F as a modulator of the TICE pathway and suggest that the anti-inflammatory functions of 4F may be a partial consequence of the codependent intestinal transport of both 4F and cholesterol. PMID:27199144

  18. Imaging Apparatus And Method

    NARCIS (Netherlands)

    Manohar, Srirang; van Leeuwen, A.G.J.M.

    2010-01-01

    A thermoacoustic imaging apparatus comprises an electromagnetic radiation source configured to irradiate a sample area and an acoustic signal detection probe arrangement for detecting acoustic signals. A radiation responsive acoustic signal generator is added outside the sample area. The detection

  19. IMAGING APPARATUS AND METHOD

    NARCIS (Netherlands)

    Manohar, Srirang; van Leeuwen, A.G.J.M.

    2008-01-01

    A thermoacoustic imaging apparatus comprises an electromagnetic radiation source configured to irradiate a sample area and an acoustic signal detection probe arrangement for detecting acoustic signals. A radiation responsive acoustic signal generator is added outside the sample area. The detection

  20. Branching ratio and angular distribution of ejected electrons from Eu 4f76p1/2 n d auto-ionizing states

    International Nuclear Information System (INIS)

    Wu Xiao-Rui; Shen Li; Zhang Kai; Dai Chang-Jian; Yang Yu-Na

    2016-01-01

    The branching ratios of ions and the angular distributions of electrons ejected from the Eu 4f 7 6p 1/2 n d auto-ionizing states are investigated with the velocity-map-imaging technique. To populate the above auto-ionizing states, the relevant bound Rydberg states have to be detected first. Two new bound Rydberg states are identified in the region between 41150 cm −1 and 44580 cm −1 , from which auto-ionization spectra of the Eu 4f 7 6p 1/2 n d states are observed with isolated core excitation method. With all preparations above, the branching ratios from the above auto-ionizing states to different final ionic states and the angular distributions of electrons ejected from these processes are measured systematically. Energy dependence of branching ratios and anisotropy parameters within the auto-ionization spectra are carefully analyzed, followed by a qualitative interpretation. (paper)

  1. Caliciviruses differ in their functional requirements for eIF4F components

    DEFF Research Database (Denmark)

    Chaudhry, Y.; Nayak, A.; Bordeleau, M-E.

    2006-01-01

    proteins can interact directly with the initiation factors eIF4E and eIF3. Translation initiation on feline calicivirus (FCV) RNA requires eIF4E because it is inhibited by recombinant 4E-BP1. However, to date, there have been no functional studies carried out with respect to norovirus translation...... translation require the RNA helicase component of the eIF4F complex, namely eIF4A, because translation was sensitive (albeit to different degrees) to a dominant negative form and to a small molecule inhibitor of eIF4A (hippuristanol). These results suggest that calicivirus RNAs differ with respect...... to their requirements for the components of the eIF4F translation initiation complex....

  2. Surface shift of the occupied and unoccupied 4f levels of the rare-earth metals

    DEFF Research Database (Denmark)

    Aldén, Magnus; Johansson, Börje; Skriver, Hans Lomholt

    1995-01-01

    The surface energy shifts of the occupied and unoccupied 4f levels for the lanthanide metals have been calculated from first principles by means of a Green’s-function technique within the tight-binding linear muffin-tin orbitals method. We use the concept of complete screening to identify...... the occupied and unoccupied 4f energy level shifts as the surface segregation energy of a 4fn-1 and 4fn+1 impurity atom, respectively, in a 4fn host metal. The calculations include both initial- and final-state effects and give values that are considerably lower than those measured on polycrystalline samples...... as well as those found in previous initial-state model calculations. The present theory agrees well with very recent high-resolution, single-crystal film measurements for Gd, Tb, Dy, Ho, Er, Tm, and Lu. We furthermore utilize the unique possibility offered by the lanthanide metals to clarify the roles...

  3. Long-lived transient anion of c-C4F8O

    Czech Academy of Sciences Publication Activity Database

    Kočišek, Jaroslav; Janečková, R.; Fedor, Juraj

    2018-01-01

    Roč. 148, č. 7 (2018), č. článku 074303. ISSN 0021-9606 R&D Projects: GA ČR GA17-04844S Institutional support: RVO:61388955 Keywords : negative-ion * electron-attachment * chemistry * c4f8o * lifetimes * gases Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 2.965, year: 2016

  4. Extended analysis of the 5g. -->. 4f emissions in H/sub 2/

    Energy Technology Data Exchange (ETDEWEB)

    Chang, E.S.; Pulchtopek, S.; Eyler, E.E.

    1984-01-15

    An analysis starting from Hund's case d has been used to extend the work of Herzberg and Jungen on the 5g..-->..4f emissions in H/sub 2/. A simple analytical expression for the line intensities is presented that agrees with their calculations is about 1%. All of the experimentally observed lines have been accounted for by including higher vibrational levels in our calculations.

  5. Uterine artery embolisation for uterine fibroids using a 4F Rosch inferior mesenteric catheter

    International Nuclear Information System (INIS)

    Ho, Simon S.M.; Cowan, Nigel C.

    2005-01-01

    Purpose:To evaluate in a prospective study the use of a 4F Rosch inferior mesenteric (RIM) catheter for uterine artery embolisation (UAE). UAE was performed in 72 women over a 37-month period. A 4F RIM braided J-curve 65-cm catheter was used in combination with an angled hydrophilic 150 cm, 0.035'' flexible tip guide-wire to catheterise the horizontal portion of both uterine arteries (UA) from a right common femoral artery (CFA) approach. Technical success was defined as successful catheterisation and embolisation of both uterine arteries. Fluoroscopic and procedure times were recorded. Mean subject age=43.7 years (range=25-57 years). Technical success was 98.6% (n=71/72). A single approach via the right CFA was used in 88.9% (n=64/72) and a bilateral CFA approach in 11.1% (n=8/72). Bilateral uterine artery catheterisation using a single 4F RIM catheter via the right CFA approach was successful in 79.2% (n=57/72). Microcatheters were used in 2.8% of patients (n=2/72). Mean fluoroscopic time=13.6±5.3 min (mean±SD). Mean procedure time=44.2±16.5 min. High technical success rate for UAE is possible using a single 4F RIM catheter via a unilateral right CFA approach, which obviates the need for Waltman loop formation, reversed curve catheters and complex suture-catheter arrangements. (orig.)

  6. Magnetoactive Acoustic Metamaterials.

    Science.gov (United States)

    Yu, Kunhao; Fang, Nicholas X; Huang, Guoliang; Wang, Qiming

    2018-04-11

    Acoustic metamaterials with negative constitutive parameters (modulus and/or mass density) have shown great potential in diverse applications ranging from sonic cloaking, abnormal refraction and superlensing, to noise canceling. In conventional acoustic metamaterials, the negative constitutive parameters are engineered via tailored structures with fixed geometries; therefore, the relationships between constitutive parameters and acoustic frequencies are typically fixed to form a 2D phase space once the structures are fabricated. Here, by means of a model system of magnetoactive lattice structures, stimuli-responsive acoustic metamaterials are demonstrated to be able to extend the 2D phase space to 3D through rapidly and repeatedly switching signs of constitutive parameters with remote magnetic fields. It is shown for the first time that effective modulus can be reversibly switched between positive and negative within controlled frequency regimes through lattice buckling modulated by theoretically predicted magnetic fields. The magnetically triggered negative-modulus and cavity-induced negative density are integrated to achieve flexible switching between single-negative and double-negative. This strategy opens promising avenues for remote, rapid, and reversible modulation of acoustic transportation, refraction, imaging, and focusing in subwavelength regimes. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. An Optimal Image-Based Method for Identification of Acoustic Emission (AE) Sources in Plate-Like Structures Using a Lead Zirconium Titanate (PZT) Sensor Array

    Science.gov (United States)

    Zhou, Li

    2018-01-01

    This paper proposes an innovative method for identifying the locations of multiple simultaneous acoustic emission (AE) events in plate-like structures from the view of image processing. By using a linear lead zirconium titanate (PZT) sensor array to record the AE wave signals, a reverse-time frequency-wavenumber (f-k) migration is employed to produce images displaying the locations of AE sources by back-propagating the AE waves. Lamb wave theory is included in the f-k migration to consider the dispersive property of the AE waves. Since the exact occurrence time of the AE events is usually unknown when recording the AE wave signals, a heuristic artificial bee colony (ABC) algorithm combined with an optimal criterion using minimum Shannon entropy is used to find the image with the identified AE source locations and occurrence time that mostly approximate the actual ones. Experimental studies on an aluminum plate with AE events simulated by PZT actuators are performed to validate the applicability and effectiveness of the proposed optimal image-based AE source identification method. PMID:29466310

  8. An Optimal Image-Based Method for Identification of Acoustic Emission (AE) Sources in Plate-Like Structures Using a Lead Zirconium Titanate (PZT) Sensor Array.

    Science.gov (United States)

    Yan, Gang; Zhou, Li

    2018-02-21

    This paper proposes an innovative method for identifying the locations of multiple simultaneous acoustic emission (AE) events in plate-like structures from the view of image processing. By using a linear lead zirconium titanate (PZT) sensor array to record the AE wave signals, a reverse-time frequency-wavenumber (f-k) migration is employed to produce images displaying the locations of AE sources by back-propagating the AE waves. Lamb wave theory is included in the f-k migration to consider the dispersive property of the AE waves. Since the exact occurrence time of the AE events is usually unknown when recording the AE wave signals, a heuristic artificial bee colony (ABC) algorithm combined with an optimal criterion using minimum Shannon entropy is used to find the image with the identified AE source locations and occurrence time that mostly approximate the actual ones. Experimental studies on an aluminum plate with AE events simulated by PZT actuators are performed to validate the applicability and effectiveness of the proposed optimal image-based AE source identification method.

  9. Battlefield acoustics

    CERN Document Server

    Damarla, Thyagaraju

    2015-01-01

    This book presents all aspects of situational awareness in a battlefield using acoustic signals. It starts by presenting the science behind understanding and interpretation of sound signals. The book then goes on to provide various signal processing techniques used in acoustics to find the direction of sound source, localize gunfire, track vehicles, and detect people. The necessary mathematical background and various classification and fusion techniques are presented. The book contains majority of the things one would need to process acoustic signals for all aspects of situational awareness in one location. The book also presents array theory, which is pivotal in finding the direction of arrival of acoustic signals. In addition, the book presents techniques to fuse the information from multiple homogeneous/heterogeneous sensors for better detection. MATLAB code is provided for majority of the real application, which is a valuable resource in not only understanding the theory but readers, can also use the code...

  10. Acoustics Research

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fisheries acoustics data are collected from more than 200 sea-days each year aboard the FRV DELAWARE II and FRV ALBATROSS IV (decommissioned) and the FSV Henry B....

  11. Room Acoustics

    Science.gov (United States)

    Kuttruff, Heinrich; Mommertz, Eckard

    The traditional task of room acoustics is to create or formulate conditions which ensure the best possible propagation of sound in a room from a sound source to a listener. Thus, objects of room acoustics are in particular assembly halls of all kinds, such as auditoria and lecture halls, conference rooms, theaters, concert halls or churches. Already at this point, it has to be pointed out that these conditions essentially depend on the question if speech or music should be transmitted; in the first case, the criterion for transmission quality is good speech intelligibility, in the other case, however, the success of room-acoustical efforts depends on other factors that cannot be quantified that easily, not least it also depends on the hearing habits of the listeners. In any case, absolutely "good acoustics" of a room do not exist.

  12. Heat capacity of RFe{sub x}Mn{sub 12-x} (R = Gd, Tb and Dy) compounds: wiping out a cooperative 4f-4f exchange interaction by breaking the 3d-4f magnetic symmetry

    Energy Technology Data Exchange (ETDEWEB)

    Pique, C; Blanco, J A; Abad, E [Departamento de Fisica, Universidad de Oviedo, Campus de Viesques, E-33204 Gijon (Spain); Burriel, R; Artigas, M [Instituto de Ciencia de Materiales de Aragon (CSIC-Universidad de Zaragoza), E-50009 Zaragoza (Spain); Fernandez-RodrIguez, J [European Synchrotron Radiation Facility, BP 220, F-38043 Grenoble Cedex (France)], E-mail: pique@uniovi.es

    2008-08-27

    Using adiabatic calorimetry the heat capacity of a series of RFe{sub x}Mn{sub 12-x} (R = Gd, Tb and Dy) compounds has been measured from 3 to 350 K. The substitution of Fe for Mn in RFe{sub x}Mn{sub 12-x} influences both the magnetic interactions on the 3d sublattice and the magnetism of R (the Neel temperature doubles on going from x = 0 to 6 and the compounds become ferromagnetic for x = 8 with Curie temperatures of around 300 K). In pure TbMn{sub 12} the heat-capacity data shows a {lambda}-type anomaly associated with the independent cooperative magnetic ordering of the R sublattice ({approx}5 K), while the anomaly related to the Mn magnetic ordering ({approx}100 K) is rather smooth, as observed in other itinerant magnetic systems such as YMn{sub 12}. In contrast, the substitution of Fe for Mn leads, on the one hand, to a more localized magnetic behaviour of the 3d sublattice, and, on the other, to magnetic polarization effects between the 3d and 4f sublattices, together with the disappearance of the cooperative magnetic ordering of the R sublattice due to the breaking of the antiferromagnetic symmetry in the 3d sublattice. This is reflected in the heat-capacity curve through a smooth Schottky-like anomaly. In the case of Gd compounds the magnitude of the exchange molecular-field parameter has been deduced by fitting the magnetic contribution to the heat capacity within a simple mean-field model. From this analysis we found that this molecular field acting on the rare-earth site increases with the iron concentration, reaching values as large as 48 T for the concentration x = 6. A similar analysis of the heat capacity in the ordered phase on the Tb compounds also leads to an enhancement of the molecular field with increasing Fe content. These results allow checking the possible crystal-field parameters for these RFe{sub x}Mn{sub 12-x} compounds.

  13. Experiments for possible hydroacoustic discrimination of free-swimming juvenile gadoid fish by analysis of broadband pulse spectra as well as 3D fish position form video images and split beam acoustics

    DEFF Research Database (Denmark)

    Lundgren, Bo; Nielsen, J. Rasmus

    2002-01-01

    , alignment of acoustic and optical-reference frames, and automatic position-fitting of fish models to manually marked fix-points on fish images. The software also performs Fourier spectrum analysis and pulse-shape analysis of broad-bandwidth echoes. Therefore, several measurement series on free...

  14. Digital image correlation, acoustic emission and ultrasonic pulse velocity for the detection of cracks in the concrete buffer of the Belgian nuclear supercontainer

    International Nuclear Information System (INIS)

    Iliopoulos, Sokratis; Tsangouri, Eleni; Aggelis, Dimitrios G.; Pyl, Lincy; Areias, Lou; Vrije Univ., Brussels

    2014-01-01

    The long term management of high-level and heat emitting radioactive waste is a worldwide concern, as it directly influences the environment and future generations. To address this issue, the Belgian Agency for Radioactive Waste and Enriched Fissile Materials has come up with the conceptual design of a massive concrete structure called Supercontainer. The feasibility to construct these structures is being evaluated through a number of scaled models that are tested using classical as well as state of the art measurement techniques. In the current paper, the results obtained from the simultaneous application of the Digital Image Correlation (DIC), the Acoustic Emission (AE) and the Ultrasonic Pulse Velocity (UPV) nondestructive testing techniques on the second scaled model for the detection and monitoring of cracks will be presented.

  15. MRI of acoustic neurinoma

    International Nuclear Information System (INIS)

    Matsumoto, Kunihiko; Niitsu, Mamoru; Yoshioka, Hiroshi; Tanaka, Yumiko; Anno, Izumi; Kuramoto, Kenmei; Itai, Yuji

    1994-01-01

    Thirty six patients were studied with a 1.5 T superconductive magnetic resonance imager. Small neurinomas appeared as homogenous intensities, large neurinomas as heterogenous intensities in T 1 and T 2 weighted images. Dural tail representing reactive change of the meninges was seen in our three acoustic neurinomas. High resolution, thin slice, MR imaging was particularly useful for intracanalicular tumor to see the relationship between the tumor and facial nerve. Total or near-total removal of tumor was performed in thirteen cases, in which functional preservation of the cochlear nerve was achieved in only three cases. (author)

  16. 4f states of He2: A new spectrum of He2 in the near infrared

    International Nuclear Information System (INIS)

    Herzberg, G.; Jungen, C.

    1986-01-01

    A new spectrum of the He 2 molecule has been discovered in the region 5100--5900 cm -1 . It is identified as the 4f--3d Rydberg transition of He 2 with a weak contribution of 4d--3p in the same region. The uncoupling of l from the internuclear axis in both the triplet and the singlet system is almost complete in the 4f complex; the appropriate quantum number is N + corresponding to the rotational angular momentum of the He + 2 core. The electronic fine structure in each N + level depends on the dipole polarizability α of the core and its anisotropy as well as on the quadrupole moment Q 2 and higher moments Q 4 ,... of the core. Conversely, from the observed structure some of the quantities characterizing the core have been determined, e.g., α = 1/3(2α/sub perpendicular/+α/sub parallel/) = 2.82 +- 0.02, Q 2 = 1.39 +- 0.13, Q 4 = 0.99 +- 0.14, all in atomic units. The detailed rotational analysis of the spectrum shows that widespread perturbations occur in the triplet 4f levels, the largest affecting the N = 6,N + = 3 and N = 9,N + = 7 levels which are shifted towards higher energies by 1 and 2 cm -1 , respectively. The perturbations are clearly caused by Δl = 2 interaction with corresponding levels of 4pπ for which Orth and Ginter have found the opposite perturbations. There are no similar perturbations in the corresponding singlet levels

  17. Red nucleus and rubrospinal tract disorganization in the absence of Pou4f1

    Science.gov (United States)

    Martinez-Lopez, Jesus E.; Moreno-Bravo, Juan A.; Madrigal, M. Pilar; Martinez, Salvador; Puelles, Eduardo

    2015-01-01

    The red nucleus (RN) is a neuronal population that plays an important role in forelimb motor control and locomotion. Histologically it is subdivided into two subpopulations, the parvocellular RN (pRN) located in the diencephalon and the magnocellular RN (mRN) in the mesencephalon. The RN integrates signals from motor cortex and cerebellum and projects to spinal cord interneurons and motor neurons through the rubrospinal tract (RST). Pou4f1 is a transcription factor highly expressed in this nucleus that has been related to its specification. Here we profoundly analyzed consequences of Pou4f1 loss-of-function in development, maturation and axonal projection of the RN. Surprisingly, RN neurons are specified and maintained in the mutant, no cell death was detected. Nevertheless, the nucleus appeared disorganized with a strong delay in radial migration and with a wider neuronal distribution; the neurons did not form a compacted population as they do in controls, Robo1 and Slit2 were miss-expressed. Cplx1 and Npas1, expressed in the RN, are transcription factors involved in neurotransmitter release, neuronal maturation and motor function processes among others. In our mutant mice, both transcription factors are lost, suggesting an abnormal maturation of the RN. The resulting altered nucleus occupied a wider territory. Finally, we examined RST development and found that the RN neurons were able to project to the spinal cord but their axons appeared defasciculated. These data suggest that Pou4f1 is necessary for the maturation of RN neurons but not for their specification and maintenance. PMID:25698939

  18. 3D Coda Attenuation Tomography of Acoustic Emission Data from Laboratory Samples as a tool for imaging pre-failure deformation mechanisms

    Science.gov (United States)

    Vinciguerra, S.; King, T. I.; Benson, P. M.; De Siena, L.

    2017-12-01

    In recent years, 3D and 4D seismic tomography have unraveled medium changes during the seismic cycle or before eruptive events. As our resolving power increases, however, complex structures increasingly affect images. Being able to interpret and understand these features requires a multi-discipline approach combining different methods, each sensitive to particular properties of the sub-surface. Rock deformation laboratory experiments can relate seismic properties to the evolving medium quantitatively. Here, an array of 1 MHz Piezo-Electric Transducers has recorded high-quality low-noise acoustic emission (AE) data during triaxial compressional experiments. Samples of Carrara Marble, Darley Dale Sandstone and Westerly Granite were deformed in saturated conditions representative of a depth of about 1 km until brittle failure. Using a time window around sample failure, AE data were filtered between 5 and 75 KHz and processed using a 3D P-coda attenuation-tomography method. Ratios of P-direct to P-coda energies calculated for each source-receiver path were inverted using the coda normalisation method for values of Q (P-wave quality factor). The results show Q-variation with respect to an average Q. Q is a combination of the effects of scattering attenuation (Qs) and intrinsic attenuation Q (Qi), which can be correlated to the sample structure. Qs primary controls energy dissipation in the presence at acoustic impedance (AI) surfaces and at fracture tips, independently of rock type, while pore fluid effects dissipate energy (Qi). Damaged zones appear as high-Q and low-Q anomalies in unsaturated and saturated samples, respectively. We have attributed frequency-dependent high-Q to resonance in the presence of AI surfaces. Low Q areas appear behind AI surfaces and are interpreted as energy shadows. These shadows can affect attenuation tomography imaging at field scale.

  19. 4-D imaging of seepage in earthen embankments with time-lapse inversion of self-potential data constrained by acoustic emissions localization

    Science.gov (United States)

    Rittgers, J. B.; Revil, A.; Planes, T.; Mooney, M. A.; Koelewijn, A. R.

    2015-02-01

    New methods are required to combine the information contained in the passive electrical and seismic signals to detect, localize and monitor hydromechanical disturbances in porous media. We propose a field experiment showing how passive seismic and electrical data can be combined together to detect a preferential flow path associated with internal erosion in a Earth dam. Continuous passive seismic and electrical (self-potential) monitoring data were recorded during a 7-d full-scale levee (earthen embankment) failure test, conducted in Booneschans, Netherlands in 2012. Spatially coherent acoustic emissions events and the development of a self-potential anomaly, associated with induced concentrated seepage and internal erosion phenomena, were identified and imaged near the downstream toe of the embankment, in an area that subsequently developed a series of concentrated water flows and sand boils, and where liquefaction of the embankment toe eventually developed. We present a new 4-D grid-search algorithm for acoustic emissions localization in both time and space, and the application of the localization results to add spatially varying constraints to time-lapse 3-D modelling of self-potential data in the terms of source current localization. Seismic signal localization results are utilized to build a set of time-invariant yet spatially varying model weights used for the inversion of the self-potential data. Results from the combination of these two passive techniques show results that are more consistent in terms of focused ground water flow with respect to visual observation on the embankment. This approach to geophysical monitoring of earthen embankments provides an improved approach for early detection and imaging of the development of embankment defects associated with concentrated seepage and internal erosion phenomena. The same approach can be used to detect various types of hydromechanical disturbances at larger scales.

  20. Band structures of 4f and 5f materials studied by angle-resolved photoelectron spectroscopy.

    Science.gov (United States)

    Fujimori, Shin-ichi

    2016-04-20

    Recent remarkable progress in angle-resolved photoelectron spectroscopy (ARPES) has enabled the direct observation of the band structures of 4f and 5f materials. In particular, ARPES with various light sources such as lasers (hν ~ 7 eV) or high-energy synchrotron radiations (hν >/~ 400 eV) has shed light on the bulk band structures of strongly correlated materials with energy scales of a few millielectronvolts to several electronvolts. The purpose of this paper is to summarize the behaviors of 4f and 5f band structures of various rare-earth and actinide materials observed by modern ARPES techniques, and understand how they can be described using various theoretical frameworks. For 4f-electron materials, ARPES studies of CeMIn5(M = Rh, Ir, and Co) and YbRh2Si2 with various incident photon energies are summarized. We demonstrate that their 4f electronic structures are essentially described within the framework of the periodic Anderson model, and that the band-structure calculation based on the local density approximation cannot explain their low-energy electronic structures. Meanwhile, electronic structures of 5f materials exhibit wide varieties ranging from itinerant to localized states. For itinerant U5f compounds such as UFeGa5, their electronic structures can be well-described by the band-structure calculation assuming that all U5f electrons are itinerant. In contrast, the band structures of localized U5f compounds such as UPd3 and UO2 are essentially explained by the localized model that treats U5f electrons as localized core states. In regards to heavy fermion U-based compounds such as the hidden-order compound URu2Si2, their electronic structures exhibit complex behaviors. Their overall band structures are generally well-explained by the band-structure calculation, whereas the states in the vicinity of EF show some deviations due to electron correlation effects. Furthermore, the electronic structures of URu2Si2 in the paramagnetic and hidden-order phases are

  1. Electronic transport properties of 4f shell elements of liquid metal using hard sphere Yukawa system

    Science.gov (United States)

    Patel, H. P.; Sonvane, Y. A.; Thakor, P. B.

    2018-04-01

    The electronic transport properties are analyzed for 4f shell elements of liquid metals. To examine the electronic transport properties like electrical resistivity (ρ), thermal conductivity (σ) and thermo electrical power (Q), we used our own parameter free model potential with the Hard Sphere Yukawa (HSY) reference system. The screening effect on aforesaid properties has been examined by using different screening functions like Hartree (H), Taylor (T) and Sarkar (S). The correlations of our resultsand other data with available experimental values are intensely promising. Also, we conclude that our newly constructed parameter free model potential is capable of explaining the above mentioned electronic transport properties.

  2. Molecular Fluoride-Bridged 3d-4f Complexes and Their Magnetic Properties

    DEFF Research Database (Denmark)

    Pedersen, K. S.; Bendix, J.

    2016-01-01

    trifluorides with very high lattice enthalpies, building block approaches are not limited to robust systems and use of labile transition metal fluoride complexes has met with unexpected success. The physical properties of fluoride-bridged 3d-4f systems are crucially dependent on coordination geometries, which...... be utilized efficiently in tailored synthesis of polynuclear complexes and extended structures. In particular, the strong affinity of the lanthanides for fluoride makes it a good choice for directed synthesis of mixed lanthanide-transition metal complexes. Despite the competition from formation of lanthanide...

  3. 4d--4f emission resonances in laser-produced plasmas

    International Nuclear Information System (INIS)

    O'Sullivan, G.; Carroll, P.K.

    1981-01-01

    Using targets containing compounds of the elements cesium through lutetium, we studied the spectra of laser-produced plasmas in the grazing-incidence region from 40 to 200 A. The spectra are characterized by strong regions of resonancelike emission extending typically over 9--18 eV. With increasing Z, the spectra show certain systematic variations in character and move monotonically toward shorter wavelengths. From a collisional-radiative plasma model, the ion stages responsible for the emision are identified as VIII through XVI. The resonances are attributed to 4-4f transitions that, because Dn = 0, tend to overlap for different ion stages of the same element

  4. Inspection of copper canisters for spent nuclear fuel by means of ultrasound. NDE of friction stir welds, nonlinear acoustics, ultrasonic imaging

    Energy Technology Data Exchange (ETDEWEB)

    Stepinski, Tadeusz (ed.); Lingvall, Fredrik; Wennerstroem, Erik; Ping Wu [Uppsala Univ., Dept. of Materials Science (Sweden). Signals and Systems

    2004-01-01

    This report contains results concerning advanced ultrasound for the inspection of copper canisters for spent nuclear fuel obtained at Signals and Systems, Uppsala University in years 2002/2003. After a short introduction a review of the NDE techniques that have been applied to the assessment of friction stir welds (FSW) is presented. The review is based on the results reported by the specialists from the USA, mostly from the aerospace industry. A separate chapter is devoted to the extended experimental and theoretical research concerning potential of nonlinear waves in NDE applications. Further studies concerning nonlinear propagation of acoustic and elastic waves (classical nonlinearity) are reported. Also a preliminary investigation of the nonlinear ultrasonic detection of contacts and interfaces (non-classical nonlinearity) is included. Report on the continuation of previous work concerning computer simulation of nonlinear propagations of ultrasonic beams in water and in immersed solids is also presented. Finally, results of an investigation concerning a new method of synthetic aperture imaging (SAI) and its comparison to the traditional phased array (PA) imaging and to the synthetic aperture focusing technique (SAFT) are presented. A new spatial-temporal filtering method is presented that is a generalization of the previously proposed filter. Spatial resolution of the proposed method is investigated and compared experimentally to that of classical SAFT and PA imaging. Performance of the proposed method for flat targets is also investigated.

  5. Inspection of copper canisters for spent nuclear fuel by means of ultrasound. NDE of friction stir welds, nonlinear acoustics, ultrasonic imaging

    International Nuclear Information System (INIS)

    Stepinski, Tadeusz; Lingvall, Fredrik; Wennerstroem, Erik; Ping Wu

    2004-01-01

    This report contains results concerning advanced ultrasound for the inspection of copper canisters for spent nuclear fuel obtained at Signals and Systems, Uppsala University in years 2002/2003. After a short introduction a review of the NDE techniques that have been applied to the assessment of friction stir welds (FSW) is presented. The review is based on the results reported by the specialists from the USA, mostly from the aerospace industry. A separate chapter is devoted to the extended experimental and theoretical research concerning potential of nonlinear waves in NDE applications. Further studies concerning nonlinear propagation of acoustic and elastic waves (classical nonlinearity) are reported. Also a preliminary investigation of the nonlinear ultrasonic detection of contacts and interfaces (non-classical nonlinearity) is included. Report on the continuation of previous work concerning computer simulation of nonlinear propagations of ultrasonic beams in water and in immersed solids is also presented. Finally, results of an investigation concerning a new method of synthetic aperture imaging (SAI) and its comparison to the traditional phased array (PA) imaging and to the synthetic aperture focusing technique (SAFT) are presented. A new spatial-temporal filtering method is presented that is a generalization of the previously proposed filter. Spatial resolution of the proposed method is investigated and compared experimentally to that of classical SAFT and PA imaging. Performance of the proposed method for flat targets is also investigated

  6. A single-sided homogeneous Green's function representation for holographic imaging, inverse scattering, time-reversal acoustics and interferometric Green's function retrieval

    Science.gov (United States)

    Wapenaar, Kees; Thorbecke, Jan; van der Neut, Joost

    2016-04-01

    Green's theorem plays a fundamental role in a diverse range of wavefield imaging applications, such as holographic imaging, inverse scattering, time-reversal acoustics and interferometric Green's function retrieval. In many of those applications, the homogeneous Green's function (i.e. the Green's function of the wave equation without a singularity on the right-hand side) is represented by a closed boundary integral. In practical applications, sources and/or receivers are usually present only on an open surface, which implies that a significant part of the closed boundary integral is by necessity ignored. Here we derive a homogeneous Green's function representation for the common situation that sources and/or receivers are present on an open surface only. We modify the integrand in such a way that it vanishes on the part of the boundary where no sources and receivers are present. As a consequence, the remaining integral along the open surface is an accurate single-sided representation of the homogeneous Green's function. This single-sided representation accounts for all orders of multiple scattering. The new representation significantly improves the aforementioned wavefield imaging applications, particularly in situations where the first-order scattering approximation breaks down.

  7. System and method to create three-dimensional images of non-linear acoustic properties in a region remote from a borehole

    Science.gov (United States)

    Vu, Cung; Nihei, Kurt T.; Schmitt, Denis P.; Skelt, Christopher; Johnson, Paul A.; Guyer, Robert; TenCate, James A.; Le Bas, Pierre-Yves

    2013-01-01

    In some aspects of the disclosure, a method for creating three-dimensional images of non-linear properties and the compressional to shear velocity ratio in a region remote from a borehole using a conveyed logging tool is disclosed. In some aspects, the method includes arranging a first source in the borehole and generating a steered beam of elastic energy at a first frequency; arranging a second source in the borehole and generating a steerable beam of elastic energy at a second frequency, such that the steerable beam at the first frequency and the steerable beam at the second frequency intercept at a location away from the borehole; receiving at the borehole by a sensor a third elastic wave, created by a three wave mixing process, with a frequency equal to a difference between the first and second frequencies and a direction of propagation towards the borehole; determining a location of a three wave mixing region based on the arrangement of the first and second sources and on properties of the third wave signal; and creating three-dimensional images of the non-linear properties using data recorded by repeating the generating, receiving and determining at a plurality of azimuths, inclinations and longitudinal locations within the borehole. The method is additionally used to generate three dimensional images of the ratio of compressional to shear acoustic velocity of the same volume surrounding the borehole.

  8. Dialkyldithiophosphoric acids - chemical properties and 5f and 4f elements ions extraction

    International Nuclear Information System (INIS)

    Pattee, D.

    1987-09-01

    This work is a contribution to the study of the properties of the dialkyldithiophosphoric acids and of the extraction of the 4f and 5f ions from weakly acidic nitrate and phosphate media. Following a complete bibliographic study, synthesis and purification of the di-2-ethylhexyl-dithiophosphoric acid (HDEHDTP) is studied. It is identified with chemical methods and spectroscopic methods (I.R., N.M.R., V.P.C.); its by products, the di-2-ethylhexyl (monothio) phosphoric acids (HDEHTP, HDEHP) are also identified and characterized. Stability against hydrolysis and radiolysis is determined. The extractive properties are studied for the 4f and 5f ions. The presence of a sulfur donor atom in HDEHDTP makes it inefficient for the extraction of trivalent lanthanides and actinides but brings out a certain selectivity for americium. For HDEHTP, the presence of an oxygen donor atom rubs out any selectivity and the extraction constants are greater. Selectivity of HDEHDTP is increased by TBP (tri-n-butylphosphate) in synergistic mixtures. The mechanism of extraction of hexavalent uranium from phosphoric medium is elucidated. A model is developed by NMR for the micellisation of the sodium salts of HDEHDTP, HDEHTP and HDEHP, and extrapolated it to the trivalent rare earth salts of the acids. The structures are verified by light scattering and low angle X-ray diffraction [fr

  9. Enzymatic hydrolysis of alkali-pretreated rice straw by Trichoderma reesei ZM4-F3

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, QiuZhuo [Department of Environmental Science and Engineering, Harbin Institute of Technology, Harbin 150090 (China); Cai, WeiMin [Department of Environmental Science and Engineering, Harbin Institute of Technology, Harbin 150090 (China); School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Minhang District, Shanghai 200240 (China)

    2008-12-15

    To minimize the cost of cellulase production, both pretreatment of the rice straw and on-site enzyme production were realized. Rice straw was first pretreated by 2% NaOH, which could increase cellulose by 54.83%, and decreased hemicellulose by 61.07% and lignin by 36.24%, respectively. Detected by SEM, significant morphological changes were observed in the tissue. Through orthogonal experiments, temperature 35 C, initial pH value 4.5 and the rotation speed of shaking bed 180 rpm were determined to be the optimal conditions for hydrolysis of rice straw by Trichoderma reesei ZM4-F3. After hydrolysis for 96 h, the production of FPA and reducing sugars could achieve 2.231 g l{sup -1} and 12.92 U ml{sup -1}, respectively. Moreover, T. reesei ZM4-F3 can decompose 68.21% of pretreated rice straw after 120 h of hydrolysis. By GC analysis, it showed that glucose is the main component of the enzymatic hydrolysates, which made GC seem to be more effective than the DNS method for analysis of the enzymatic hydrolysates as it can detect the concentration of each kind of monosaccharide more accurately. (author)

  10. Acoustic biosensors.

    Science.gov (United States)

    Fogel, Ronen; Limson, Janice; Seshia, Ashwin A

    2016-06-30

    Resonant and acoustic wave devices have been researched for several decades for application in the gravimetric sensing of a variety of biological and chemical analytes. These devices operate by coupling the measurand (e.g. analyte adsorption) as a modulation in the physical properties of the acoustic wave (e.g. resonant frequency, acoustic velocity, dissipation) that can then be correlated with the amount of adsorbed analyte. These devices can also be miniaturized with advantages in terms of cost, size and scalability, as well as potential additional features including integration with microfluidics and electronics, scaled sensitivities associated with smaller dimensions and higher operational frequencies, the ability to multiplex detection across arrays of hundreds of devices embedded in a single chip, increased throughput and the ability to interrogate a wider range of modes including within the same device. Additionally, device fabrication is often compatible with semiconductor volume batch manufacturing techniques enabling cost scalability and a high degree of precision and reproducibility in the manufacturing process. Integration with microfluidics handling also enables suitable sample pre-processing/separation/purification/amplification steps that could improve selectivity and the overall signal-to-noise ratio. Three device types are reviewed here: (i) bulk acoustic wave sensors, (ii) surface acoustic wave sensors, and (iii) micro/nano-electromechanical system (MEMS/NEMS) sensors. © 2016 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

  11. A study on the acoustical holography

    International Nuclear Information System (INIS)

    Shin, S.H.; Lee, J.H.; Jang, M.S.

    1979-01-01

    Theoretical and experimental investigations of acoustical holograms, and the optical reconstruction of their images are described. Acoustical holograms are constructed through the use of sound waves of 14 KHz-16 KHz frequency range. The virtual images and conjugate images are reconstructed using He-Ne gas laser(Wavelength 6,328A) light. The effect on the reconstructed images of the wavelength of the sound waves and of the scanning plane are discussed. Furthermore, the three dimensional information memory in acoustical holograms is discussed. (author)

  12. WE-EF-210-07: Development of a Minimally Invasive Photo Acoustic Imaging System for Early Prostate Cancer Detection

    Energy Technology Data Exchange (ETDEWEB)

    Sano, M; Yousefi, S; Xing, L [Stanford University School of Medicine, Stanford, CA (United States)

    2015-06-15

    Purpose: The objective of this work is to design, implement and characterize a catheter-based ultrasound/photoacoustic imaging probe for early-diagnosis of prostate cancer and to aid in image-guided radiation therapy. Methods: The need to image across 6–10cm of tissue to image the whole prostate gland limits the resolution achievable with a transrectal ultrasound approach. In contrast, the urethra bisects the prostate gland, providing a minimally invasive pathway for deploying a high resolution ultrasound transducer. Utilizing a high-frequency (20MHz) ultrasound/photoacoustic probe, high-resolution structural and molecular imaging of the prostate tissue is possible. A custom 3D printed probe containing a high-frequency single-element ultrasound transducer is utilized. The diameter of the probe is designed to fit inside a Foley catheter and the probe is rotated around the central axis to achieve a circular B-scan. A custom ultrasound amplifier and receiver was set up to trigger the ultrasound pulse transmission and record the reflected signal. The reconstructed images were compared to images generated by traditional 5 MHz ultrasound transducers. Results: The preliminary results using the high-frequency ultrasound probe show that it is possible to resolve finely detailed information in a prostate tissue phantom that was not achievable with previous low-frequency ultrasound systems. Preliminary ultrasound imaging was performed on tissue mimicking phantom and sensitivity and signal-to-noise ratio of the catheter was measured. Conclusion: In order to achieve non-invasive, high-resolution, structural and molecular imaging for early-diagnosis and image-guided radiation therapy of the prostate tissue, a transurethral catheter was designed. Structural/molecular imaging using ultrasound/photoacoustic of the prostate tissue will allow for localization of hyper vascularized areas for early-stage prostate cancer diagnosis.

  13. Polymorphs of LiFeSO4F as cathode materials for lithium ion batteries - a first principle computational study.

    Science.gov (United States)

    Chung, Sai Cheong; Barpanda, Prabeer; Nishimura, Shin-Ichi; Yamada, Yuki; Yamada, Atsuo

    2012-06-28

    We have investigated polymorphs of LiFeSO4F, tavorite and triplite, which have been reported as cathode materials for lithium ion batteries. The predicted voltages are 3.64 and 3.90 V for tavorite and triplite, respectively, which agreed excellently with experimental data. It is found that the lithiated states (LiFeSO4F) of the polymorphs are almost degenerate in energy. The difference in voltage is mainly due to the difference in the stabilities of the delithiated states (FeSO4F). This is rationalized by the Fe(3+)-Fe(3+) repulsion in the edge sharing geometry of the triplite structure.

  14. Acoustic emission

    International Nuclear Information System (INIS)

    Straus, A.; Lopez Pumarega, M.I.; Di Gaetano, J.O.; D'Atellis, C.E.; Ruzzante, J.E.

    1990-01-01

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

  15. Building Acoustics

    Science.gov (United States)

    Cowan, James

    This chapter summarizes and explains key concepts of building acoustics. These issues include the behavior of sound waves in rooms, the most commonly used rating systems for sound and sound control in buildings, the most common noise sources found in buildings, practical noise control methods for these sources, and the specific topic of office acoustics. Common noise issues for multi-dwelling units can be derived from most of the sections of this chapter. Books can be and have been written on each of these topics, so the purpose of this chapter is to summarize this information and provide appropriate resources for further exploration of each topic.

  16. A pilot study of the characterization of hepatic tissue strain in children with cystic-fibrosis-associated liver disease (CFLD) by acoustic radiation force impulse imaging

    International Nuclear Information System (INIS)

    Behrens, Christopher B.; Langholz, Juliane H.; Eiler, Jessika; Jenewein, Raphael; Fuchs, Konstantin; Alzen, Gerhard F.P.; Naehrlich, Lutz; Harth, Sebastian; Krombach, Gabriele A.

    2013-01-01

    Progressive fibrotic alterations of liver tissue represent a major complication in children with cystic fibrosis. Correct assessment of cystic-fibrosis-associated liver disease (CFLD) in clinical routine is a challenging issue. Sonographic elastography based on acoustic radiation force impulse imaging (ARFI) is a new noninvasive approach for quantitatively assessing in vivo elasticity of biological tissues in many organs. To characterize ARFI elastography as a diagnostic tool to assess alteration of liver tissue elasticity related to cystic fibrosis in children. ARFI elastography and B-mode US imaging were performed in 36 children with cystic fibrosis. The children's clinical history and laboratory parameters were documented. According to the findings on conventional US, children were assigned to distinct groups indicating severity of hepatic tissue alterations. The relationship between US findings and respective elastography values was assessed. Additionally, differences between ARFI elastography values of each US group were statistically tested. Children with sonomorphologic characteristics of fibrotic tissue remodeling presented significantly increased values for tissue elasticity. Children with normal B-mode US or discrete signs of hepatic tissue alterations showed a tendency toward increased tissue stiffness indicating early tissue remodeling. Assessment of children with CFLD by means of ARFI elastography yields adequate results when compared to conventional US. For detection of early stages of liver disease with mild fibrotic reactions of hepatic tissue, ARFI elastography might offer diagnostic advantages over conventional US. Thus, liver stiffness measured by means of elastography might represent a valuable biological parameter for evaluation and follow-up of CFLD. (orig.)

  17. A pilot study of the characterization of hepatic tissue strain in children with cystic-fibrosis-associated liver disease (CFLD) by acoustic radiation force impulse imaging

    Energy Technology Data Exchange (ETDEWEB)

    Behrens, Christopher B.; Langholz, Juliane H.; Eiler, Jessika; Jenewein, Raphael; Fuchs, Konstantin; Alzen, Gerhard F.P. [University Hospital Giessen, Department of Pediatric Radiology, Giessen (Germany); Naehrlich, Lutz [University Hospital Giessen, Department of Pediatrics, Giessen (Germany); Harth, Sebastian; Krombach, Gabriele A. [University Hospital Giessen, Department of Radiology, Giessen (Germany)

    2013-03-15

    Progressive fibrotic alterations of liver tissue represent a major complication in children with cystic fibrosis. Correct assessment of cystic-fibrosis-associated liver disease (CFLD) in clinical routine is a challenging issue. Sonographic elastography based on acoustic radiation force impulse imaging (ARFI) is a new noninvasive approach for quantitatively assessing in vivo elasticity of biological tissues in many organs. To characterize ARFI elastography as a diagnostic tool to assess alteration of liver tissue elasticity related to cystic fibrosis in children. ARFI elastography and B-mode US imaging were performed in 36 children with cystic fibrosis. The children's clinical history and laboratory parameters were documented. According to the findings on conventional US, children were assigned to distinct groups indicating severity of hepatic tissue alterations. The relationship between US findings and respective elastography values was assessed. Additionally, differences between ARFI elastography values of each US group were statistically tested. Children with sonomorphologic characteristics of fibrotic tissue remodeling presented significantly increased values for tissue elasticity. Children with normal B-mode US or discrete signs of hepatic tissue alterations showed a tendency toward increased tissue stiffness indicating early tissue remodeling. Assessment of children with CFLD by means of ARFI elastography yields adequate results when compared to conventional US. For detection of early stages of liver disease with mild fibrotic reactions of hepatic tissue, ARFI elastography might offer diagnostic advantages over conventional US. Thus, liver stiffness measured by means of elastography might represent a valuable biological parameter for evaluation and follow-up of CFLD. (orig.)

  18. Series of chiral interpenetrating 3d-4f heterometallic MOFs: Luminescent sensors and magnetic properties

    Science.gov (United States)

    Zhang, Xiaolei; Chen, Chen; Liu, Xiaoli; Gao, Peng; Hu, Ming

    2017-09-01

    Series of chiral 3d-4f heterometallic MOFs based on a multidentate terpyridyl carboxylic acid ligand have been synthesized under the solvothermal conditions, namely, [LnZnL(CO3)2(H2O)]n (Ln = Eu (1), Gd (2), Dy (3), Ho (4), Er (5), Tm (6), Yb (7), Lu (8)) (HL = 4‧-(4-carboxyphenyl)-2,2‧:6‧,2″-terpyridine). Compounds 1-8 were structurally characterized by the elemental analyses, infrared spectra, and single crystal X-ray diffractions. Compounds 1-8 exhibit the chiral interpenetrating 3D frameworks. Interestingly, 1 can serve as the luminescent sensor to detect nitrobenzene molecules with high sensitivity. The investigations on CD spectra of single crystals clearly assigned the Cotton effect, indicating that there exist two chiral enantiomers of 1-8 in the course of crystallization. The magnetic properties of 2 and 7 were exploited, respectively.

  19. 4f and 5f trivalent ions complexation by diamides and uses in solvent extraction

    International Nuclear Information System (INIS)

    Huber, H.

    1984-06-01

    Extractive properties of N,N'-tetraalkylmalonamides were investigated in view to separate the actinides contained in highly radioactive wastes. N,N'-dimethyldioctylmalonamide (DMDOMA) was selected. It extracts trivalent actinide and lanthanide from concentrated nitric acid. Mineral acids extraction was studied, especially HNO 3 extraction. The distribution of HNO 3 can be interpreted by assuming that in the organic phase three main species are present: HNO 3 (DMDOMA) 2 , HNO 3 DMDOMA, (HNO 3 ) 2 DMDOMA. 5f and 4f trivalent ions are extracted according to the mechanism: M 3+ + 3NO 3 - + 4DMDOMA in equilibrium with [M(DMDOMA) 2 (NO 3 ) 3 ].(DMDOMA) 2 . The extraction of important ions like U(VI), Np(V), Pu(IV), Pu(VI), Zr(IV) and Fe(III) was investigated. The results showed that DMDOMA behave line the carbamoylmethylenephosphonates and could be an interesting alternative to these organophosphorus extractants [fr

  20. Impulse attack-free four random phase mask encryption based on a 4-f optical system.

    Science.gov (United States)

    Kumar, Pramod; Joseph, Joby; Singh, Kehar

    2009-04-20

    Optical encryption methods based on double random phase encryption (DRPE) have been shown to be vulnerable to different types of attacks. The Fourier plane random phase mask (RPM), which is the most important key, can be cracked with a single impulse function attack. Such an attack is viable because the Fourier transform of a delta function is a unity function. Formation of a unity function can be avoided if RPMs are placed in front of both lenses in a 4-f optical setup, thereby protecting the DRPE from an impulse attack. We have performed numerical simulations to verify the proposed scheme. Resistance of this scheme is checked against the brute force and the impulse function attacks. The experimental results validate the feasibility of the scheme.

  1. Magnetism and superconductivity driven by identical 4f states in a heavy-fermion metal

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Joe E [Los Alamos National Laboratory; Nair, S [MAX PLANCK INST.; Stockert, O [MAX PLANCK INST.; Witte, U [INST. FUR FESTKORPERPHYSIK; Nicklas, M [MAX PLANCK INST.; Schedler, R [HELMHOLTZ - ZENTRUM; Bianchi, A [UC, IRVINE; Fisk, Z [UC, IRVINE; Wirth, S [MAX PLANCK INST.; Steglich, K [HELMHOLTZ - ZENTRUM

    2009-01-01

    The apparently inimical relationship between magnetism and superconductivity has come under increasing scrutiny in a wide range of material classes, where the free energy landscape conspires to bring them in close proximity to each other. Particularly enigmatic is the case when these phases microscopically interpenetrate, though the manner in which this can be accomplished remains to be fully comprehended. Here, we present combined measurements of elastic neutron scattering, magnetotransport, and heat capacity on a prototypical heavy fermion system, in which antiferromagnetism and superconductivity are observed. Monitoring the response of these states to the presence of the other, as well as to external thermal and magnetic perturbations, points to the possibility that they emerge from different parts of the Fermi surface. Therefore, a single 4f state could be both localized and itinerant, thus accounting for the coexistence of magnetism and superconductivity.

  2. Synthesis and magnetic properties of heteronuclear 3d-4f compound

    International Nuclear Information System (INIS)

    Cristovao, B.; Ferenc, W.

    2007-01-01

    A novel heteronuclear 3d-4f compound having formula NdCu 3 L 3 ·13H 2 O (where H 3 L = Schiff base derived from 5-bromosalicylaldehyde and glycylglycine and L 3 = C 11 H 8 N 2 O 4 Br) was obtained. It was characterized by elemental and thermal analyses and magnetic measurements. The Cu(II)-Nd(III) compound is stable up to 323 K. During dehydration process the water molecules are lost in two stages. The magnetic susceptibility data for this complex change with temperature according to the Curie-Weiss law with Θ = -35 K. The magnetic moment values decrease from 5.00μ B at 303 K to 4.38μB at 76 K. (author)

  3. Analysis of a 4f-5g supermultiplet of Fe II around 1 μm

    International Nuclear Information System (INIS)

    Rosberg, M.; Johansson, S.

    1992-01-01

    The Fourier-transform spectrum from an iron-neon hollow-cathode lamp has been studied in the region 9000-11000A. The 3d 6 ( 5 D)5g subconfiguration of Fe II has been established by means of about 220 newly identified 4f-5g transitions. The 5g configuration is well represented by JK coupling, which is demonstrated by the application of the quadrupolic approximation. A consistent pattern in the FWHM for various types of Fe II transitions has been observed. Calculated oscillator strengths are given for all observed lines and their relative accuracy is estimated from observed intensities. The new data offer unprecedented tools for diagnostics of stellar atmospheres. (orig.)

  4. 3d-4f magnetic interaction with density functional theory plus u approach: local Coulomb correlation and exchange pathways.

    Science.gov (United States)

    Zhang, Yachao; Yang, Yang; Jiang, Hong

    2013-12-12

    The 3d-4f exchange interaction plays an important role in many lanthanide based molecular magnetic materials such as single-molecule magnets and magnetic refrigerants. In this work, we study the 3d-4f magnetic exchange interactions in a series of Cu(II)-Gd(III) (3d(9)-4f(7)) dinuclear complexes based on the numerical atomic basis-norm-conserving pseudopotential method and density functional theory plus the Hubbard U correction approach (DFT+U). We obtain improved description of the 4f electrons by including the semicore 5s5p states in the valence part of the Gd-pseudopotential. The Hubbard U correction is employed to treat the strongly correlated Cu-3d and Gd-4f electrons, which significantly improve the agreement of the predicted exchange constants, J, with experiment, indicating the importance of accurate description of the local Coulomb correlation. The high efficiency of the DFT+U approach enables us to perform calculations with molecular crystals, which in general improve the agreement between theory and experiment, achieving a mean absolute error smaller than 2 cm(-1). In addition, through analyzing the physical effects of U, we identify two magnetic exchange pathways. One is ferromagnetic and involves an interaction between the Cu-3d, O-2p (bridge ligand), and the majority-spin Gd-5d orbitals. The other one is antiferromagnetic and involves Cu-3d, O-2p, and the empty minority-spin Gd-4f orbitals, which is suppressed by the planar Cu-O-O-Gd structure. This study demonstrates the accuracy of the DFT+U method for evaluating the 3d-4f exchange interactions, provides a better understanding of the exchange mechanism in the Cu(II)-Gd(III) complexes, and paves the way for exploiting the magnetic properties of the 3d-4f compounds containing lanthanides other than Gd.

  5. Extraction of Overt Verbal Response from the Acoustic Noise in a Functional Magnetic Resonance Imaging Scan by Use of Segmented Active Noise Cancellation

    Science.gov (United States)

    Jung, Kwan-Jin; Prasad, Parikshit; Qin, Yulin; Anderson, John R.

    2013-01-01

    A method to extract the subject's overt verbal response from the obscuring acoustic noise in an fMRI scan is developed by applying active noise cancellation with a conventional MRI microphone. Since the EPI scanning and its accompanying acoustic noise in fMRI are repetitive, the acoustic noise in one time segment was used as a reference noise in suppressing the acoustic noise in subsequent segments. However, the acoustic noise from the scanner was affected by the subject's movements, so the reference noise was adaptively adjusted as the scanner's acoustic properties varied in time. This method was successfully applied to a cognitive fMRI experiment with overt verbal responses. PMID:15723385

  6. Surface and bulk 4f-photoemission spectra of CeIn3 and CeSn3

    International Nuclear Information System (INIS)

    Kim, H.; Tjernberg, O.; Chiaia, G.; Kumigashira, H.; Takahashi, T.; Duo, L.; Sakai, O.; Kasaya, M.; Lindau, I.

    1997-01-01

    Resonant photoemission spectroscopy was performed on CeIn 3 and CeSn 3 at the 4d-4f and 3d-4f core thresholds. Using the different surface sensitivity between the two photon energies, surface and bulk 4f-photoemission spectra were derived for both compounds. With the noncrossing approximation of the Anderson impurity model, the 4d-4f resonant spectra together with the surface and bulk spectra were self-consistently analyzed to obtain the microscopic parameters such as the 4f-electron energy and the hybridization strength with conduction electrons. The result shows a substantial difference in these parameters between the surface and the bulk, indicating that it is important to take into account the surface effect in analyzing photoemission spectra of Ce compounds. It is also found that the 4f surface core-level shift is different between CeIn 3 and CeSn 3 . copyright 1997 The American Physical Society

  7. PVT Degradation Studies: Acoustic Diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Dib, Gerges [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Tucker, Brian J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kouzes, Richard T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Smith, Philip J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2017-04-01

    Under certain environmental conditions, polyvinyl toluene (PVT) plastic scintillator has been observed to undergo internal fogging. This document reports on a study of acoustic techniques to determine whether they can provide a diagnostic for the fogging of PVT. Different ultrasound techniques were employed for detecting the level of internal fogging in PVT, including wave velocity measurements, attenuation, nonlinear acoustics, and acoustic microscopy. The results indicate that there are linear relations between the wave velocity and wave attenuation with the level of internal fogging. The effects of fogging on ultrasound wave attenuation is further verified by acoustic microscopy imaging, where regions with fog in the specimen demonstration higher levels of attenuation compared to clear regions. Results from the nonlinear ultrasound measurements were inconclusive due to high sensitivities to transducer coupling and fixture variabilities.

  8. Acoustic Characterization of Mesoscale Objects

    Energy Technology Data Exchange (ETDEWEB)

    Chinn, D; Huber, R; Chambers, D; Cole, G; Balogun, O; Spicer, J; Murray, T

    2007-03-13

    This report describes the science and engineering performed to provide state-of-the-art acoustic capabilities for nondestructively characterizing mesoscale (millimeter-sized) objects--allowing micrometer resolution over the objects entire volume. Materials and structures used in mesoscale objects necessitate the use of (1) GHz acoustic frequencies and (2) non-contacting laser generation and detection of acoustic waves. This effort demonstrated that acoustic methods at gigahertz frequencies have the necessary penetration depth and spatial resolution to effectively detect density discontinuities, gaps, and delaminations. A prototype laser-based ultrasonic system was designed and built. The system uses a micro-chip laser for excitation of broadband ultrasonic waves with frequency components reaching 1.0 GHz, and a path-stabilized Michelson interferometer for detection. The proof-of-concept for mesoscale characterization is demonstrated by imaging a micro-fabricated etched pattern in a 70 {micro}m thick silicon wafer.

  9. Holograms for acoustics.

    Science.gov (United States)

    Melde, Kai; Mark, Andrew G; Qiu, Tian; Fischer, Peer

    2016-09-22

    Holographic techniques are fundamental to applications such as volumetric displays, high-density data storage and optical tweezers that require spatial control of intricate optical or acoustic fields within a three-dimensional volume. The basis of holography is spatial storage of the phase and/or amplitude profile of the desired wavefront in a manner that allows that wavefront to be reconstructed by interference when the hologram is illuminated with a suitable coherent source. Modern computer-generated holography skips the process of recording a hologram from a physical scene, and instead calculates the required phase profile before rendering it for reconstruction. In ultrasound applications, the phase profile is typically generated by discrete and independently driven ultrasound sources; however, these can only be used in small numbers, which limits the complexity or degrees of freedom that can be attained in the wavefront. Here we introduce monolithic acoustic holograms, which can reconstruct diffraction-limited acoustic pressure fields and thus arbitrary ultrasound beams. We use rapid fabrication to craft the holograms and achieve reconstruction degrees of freedom two orders of magnitude higher than commercial phased array sources. The technique is inexpensive, appropriate for both transmission and reflection elements, and scales well to higher information content, larger aperture size and higher power. The complex three-dimensional pressure and phase distributions produced by these acoustic holograms allow us to demonstrate new approaches to controlled ultrasonic manipulation of solids in water, and of liquids and solids in air. We expect that acoustic holograms will enable new capabilities in beam-steering and the contactless transfer of power, improve medical imaging, and drive new applications of ultrasound.

  10. Error analysis by means of acoustic holography

    International Nuclear Information System (INIS)

    Kutzner, J.; Wuestenberg, H.

    1976-01-01

    The possilbilities to use the acoustical holography in nondestructive testing are discussed. Although compared to optical holography the image quality of acoustical holography is reduced this technique can give important informations about the shape of defects. Especially in nondestructive testing of thick walled components no alternative exists until now. (orig.) [de

  11. Synthesis, crystal structure and electrochemical properties of the manganese-doped LiNaFe[PO{sub 4}]F materials

    Energy Technology Data Exchange (ETDEWEB)

    Ben Yahia, Hamdi, E-mail: benyahia.hamdi@aist.go.jp; Shikano, Masahiro, E-mail: shikano.masahiro@aist.go.jp; Sakaebe, Hikari; Kobayashi, Hironori

    2013-08-15

    The new compounds LiNaFe{sub 1−x}Mn{sub x}[PO{sub 4}]F (x ≤ 1/4) were synthesized by a solid state reaction route. The crystal structure of LiNaFe{sub 3/4}Mn{sub 1/4}[PO{sub 4}]F was determined from single crystal X-ray diffraction data. LiNaFe{sub 3/4}Mn{sub 1/4}[PO{sub 4}]F crystallizes with the Li{sub 2}Ni[PO{sub 4}]F-type structure, space group Pnma, a = 10.9719(13), b = 6.3528(7), c = 11.4532(13) Å, V = 798.31(16) Å{sup 3}, and Z = 8. The structure consists of edge-sharing (Fe{sub 3/4}Mn{sub 1/4})O{sub 4}F{sub 2} octahedra forming (Fe{sub 3/4}Mn{sub 1/4})FO{sub 3} chains running along the b-axis. These chains are interlinked by PO{sub 4} tetrahedra forming a three-dimensional framework with the tunnels and the cavities filled by the well-ordered sodium and lithium atoms, respectively. The manganese-doped phases show poor electrochemical behavior comparing to the iron pure phase LiNaFe[PO{sub 4}]F. - Highlights: • We investigated the synthesis of LiNaFe{sub 1−x}Mn{sub x}[PO{sub 4}]F by solid state reaction. • We demonstrated that a solid solution exist only for x ≤ 1/4. • We solved the crystal structure of LiNaFe{sub 3/4}Mn{sub 1/4}[PO{sub 4}]F using single crystal data. • We studied the electrochemical performances of LiNaFe{sub 1−x}Mn{sub x}[PO{sub 4}]F. • The Mn-doped phases have poor electrochemical performances comparing to LiNaFe[PO{sub 4}]F.

  12. Properties of C4F7N–CO2 thermal plasmas: thermodynamic properties, transport coefficients and emission coefficients

    Science.gov (United States)

    Wu, Yi; Wang, Chunlin; Sun, Hao; Murphy, Anthony B.; Rong, Mingzhe; Yang, Fei; Chen, Zhexin; Niu, Chunpin; Wang, Xiaohua

    2018-04-01

    The thermophysical properties, including composition, thermodynamic properties, transport coefficients and net emission coefficients, of thermal plasmas formed from pure iso-C4 perfluoronitrile C4F7N and C4F7N–CO2 mixtures are calculated for temperatures from 300 to 30 000 K and pressures from 0.1 to 20 atm. These gases have received much attention as alternatives to SF6 for use in circuit breakers, due to the low global warming potential and good dielectric properties of C4F7N. Since the parameters of the large molecules formed in the dissociation of C4F7N are unavailable, the partition function and enthalpy of formation were calculated using computational chemistry methods. From the equilibrium composition calculations, it was found that when C4F7N is mixed with CO2, CO2 can capture C atoms from C4F7N, producing CO, since the system consisting of small molecules such as CF4 and CO has lower energy at room temperature. This is in agreement with previous experimental results, which show that CO dominates the decomposition products of C4F7N–CO2 mixtures; it could limit the repeated breaking performance of C4F7N. From the point of view of chemical stability, the mixing ratio of CO2 should therefore be chosen carefully. Through comparison with common arc quenching gases (including SF6, CF3I and C5F10O), it is found that for the temperature range for which electrical conductivity remains low, pure C4F7N has similar ρC p (product of mass density and specific heat) properties to SF6, and higher radiative emission coefficient, properties that are correlated with good arc extinguishing capability. For C4F7N–CO2 mixtures, the electrical conductivity is very close to that of SF6 while the ρC p peak at 7000 K caused by decomposition of CO implies inferior interruption capability to that of SF6. The calculated properties will be useful in arc simulations.

  13. Use of the 4F Roesch Inferior Mesenteric Catheter in Embolization Procedures in the Pelvis: A Review of 300 Cases

    International Nuclear Information System (INIS)

    Kroencke, Thomas J.; Kluner, Claudia; Hamm, Bernd; Gauruder-Burmester, Annett

    2007-01-01

    The aim of this study is to evaluate the use of a 4F Roesch inferior mesenteric (RIM) catheter for pelvic embolization procedures. Between October 2000 and January 2006, 364 patients (357 female, 7 male; age: 23-67 years) underwent embolization of various pathologies [uterine fibroids (n = 324), pure adenomyosis of the uterus (n = 19), postpartum hemorrhage (n =1), traumatic or postoperative hemorrhage (n = 9), bleeding related to cervical cancer (n =7), AV malformation of the uterus (n = 2) and high-flow priapism (n = 2)] at a single institution. In all cases, bilateral catheterization was primarily attempted with the use of a 4F hook-shaped braided endhole catheter (Roesch-Inferior-Mesenteric, RIM-Catheter, Cordis, Miami, FL). Frequency of initial failure to catheterize the vascular territory of interest and carry out the embolization were recorded and the types of difficulty encountered were noted. Catherization of the main stem of the vessel territory of interest with the use of a unilateral femoral approach and the 4F RIM catherer was successful in 334/364 (91.8%) the embolization cases. Bilateral catheterization of the internal iliac arteries using a single common femoral artery access and the 4F RIM catheter was achieved in 322/364 (88.5%) patients. In 12/364 (3.3%) patients, a contralateral puncture was performed and the same 4F catheter was used. In 28/364 (7.7%) cases the 4F RIM catheter was exchanged for a catheter with a cobra-shaped or sidewinder configuration. The 4F RIM catheter is a simple and valuable alternative to catheters and techniques commonly employed for pelvic artery embolization

  14. Acoustic Territoriality

    DEFF Research Database (Denmark)

    Kreutzfeldt, Jacob

    2011-01-01

    Under the heading of "Gang i København" a number of initiatives was presented by the Lord Mayer and the Technical and Environmental Mayer of Copenhagen in May 2006. The aim of the initiative, which roughly translates to Lively Copenhagen, was both to make Copenhagen a livelier city in terms of city...... this article outline a few approaches to a theory of acoustic territoriality....

  15. Acoustic lenses

    International Nuclear Information System (INIS)

    Kittmer, C.A.

    1983-03-01

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

  16. Evaluation of damage accumulation behavior and strength anisotropy of NITE SiC/SiC composites by acoustic emission, digital image correlation and electrical resistivity monitoring

    International Nuclear Information System (INIS)

    Nozawa, Takashi; Ozawa, Kazumi; Asakura, Yuuki; Kohyama, Akira; Tanigawa, Hiroyasu

    2014-01-01

    Understanding the cracking process of the composites is essential to establish the design basis for practical applications. This study aims to investigate the damage accumulation process and its anisotropy for nano-infiltration transient eutectic sintered (NITE) SiC/SiC composites by various characterization techniques such as the acoustic emission (AE), digital image correlation (DIC) and electrical resistivity (ER) measurements. Cracking behavior below the proportional limit stress (PLS) was specifically addressed. Similar to the other generic SiC/SiC composites, the 1st AE event was identified below the PLS for NITE SiC/SiC composites with a dependency of fabric orientation. The DIC results support that the primary failure mode depending on fiber orientation affected more than the other minor modes did. Detailed AE waveform analysis by wavelet shows a potential to classify the failure behavior depending on architecture. Cracking below the PLS is a potential concern in component deign but the preliminary ER measurements imply that the impact of cracking below the PLS on composite function was limited

  17. Detection of non-alcoholic steatohepatitis in patients with morbid obesity before bariatric surgery: preliminary evaluation with acoustic radiation force impulse imaging

    International Nuclear Information System (INIS)

    Guzman-Aroca, F.; Reus, M.; Dios Berna-Serna, Juan de; Frutos-Bernal, M.D.; Lujan-Mompean, J.A.; Parrilla, P.; Bas, A.

    2012-01-01

    To investigate the utility of acoustic radiation force impulse (ARFI) imaging, with the determination of shear wave velocity (SWV), to differentiate non-alcoholic fatty liver disease (NAFLD) from non-alcoholic steatohepatitis (NASH) in patients with morbid obesity before bariatric surgery. Thirty-two patients with morbid obesity were evaluated with ARFI and conventional ultrasound before bariatric surgery. The ARFI and ultrasound results were compared with liver biopsy findings, which is the reference standard. The patients were classed according to their histological findings into three groups: group A, simple steatosis; group B, inflammation; and group C, fibrosis. The median SWV was 1.57 ± 0.79 m/s. Hepatic alterations were observed in the histopathological findings for all the patients in the study (100 %), with the results of the laboratory tests proving normal. Differences in SWV were also observed between groups A, B and C: 1.34 ± 0.90 m/s, 1.55 ± 0.79 m/s and 1.86 ± 0.75 m/s (P < 0.001), respectively. The Az for differentiating NAFLD from NASH or fibrosis was 0.899 (optimal cut-off value 1.3 m/s; sensitivity 85 %; specificity 83.3 %). The ARFI technique is a useful diagnostic tool for differentiating NAFLD from NASH in asymptomatic patients with morbid obesity. (orig.)

  18. Detection of non-alcoholic steatohepatitis in patients with morbid obesity before bariatric surgery: preliminary evaluation with acoustic radiation force impulse imaging

    Energy Technology Data Exchange (ETDEWEB)

    Guzman-Aroca, F.; Reus, M.; Dios Berna-Serna, Juan de [Virgen de la Arrixaca University Hospital, Department of of Radiology, El Palmar, Murcia (Spain); Frutos-Bernal, M.D.; Lujan-Mompean, J.A.; Parrilla, P. [Virgen de la Arrixaca University Hospital, Department of Surgery, El Palmar, Murcia (Spain); Bas, A. [Virgen de la Arrixaca University Hospital, Department of Pathology, El Palmar, Murcia (Spain)

    2012-11-15

    To investigate the utility of acoustic radiation force impulse (ARFI) imaging, with the determination of shear wave velocity (SWV), to differentiate non-alcoholic fatty liver disease (NAFLD) from non-alcoholic steatohepatitis (NASH) in patients with morbid obesity before bariatric surgery. Thirty-two patients with morbid obesity were evaluated with ARFI and conventional ultrasound before bariatric surgery. The ARFI and ultrasound results were compared with liver biopsy findings, which is the reference standard. The patients were classed according to their histological findings into three groups: group A, simple steatosis; group B, inflammation; and group C, fibrosis. The median SWV was 1.57 {+-} 0.79 m/s. Hepatic alterations were observed in the histopathological findings for all the patients in the study (100 %), with the results of the laboratory tests proving normal. Differences in SWV were also observed between groups A, B and C: 1.34 {+-} 0.90 m/s, 1.55 {+-} 0.79 m/s and 1.86 {+-} 0.75 m/s (P < 0.001), respectively. The Az for differentiating NAFLD from NASH or fibrosis was 0.899 (optimal cut-off value 1.3 m/s; sensitivity 85 %; specificity 83.3 %). The ARFI technique is a useful diagnostic tool for differentiating NAFLD from NASH in asymptomatic patients with morbid obesity. (orig.)

  19. Visualization of Protease Activity In Vivo Using an Activatable Photo-Acoustic Imaging Probe Based on CuS Nanoparticles

    Science.gov (United States)

    Yang, Kai; Zhu, Lei; Nie, Liming; Sun, Xiaolian; Cheng, Liang; Wu, Chenxi; Niu, Gang; Chen, Xiaoyuan; Liu, Zhuang

    2014-01-01

    Herein, we for the first time report a novel activatable photoacoustic (PA) imaging nano-probe for in vivo detection of cancer-related matrix metalloproteinases (MMPs). A black hole quencher 3 (BHQ3) which absorbs red light is conjugated to near-infrared (NIR)-absorbing copper sulfide (CuS) nanoparticles via a MMP-cleavable peptide linker. The obtained CuS-peptide-BHQ3 (CPQ) nano-probe exhibits two distinctive absorption peaks at 630 nm and 930 nm. Inside the tumor microenviorment where MMPs present, the MMP-sensitive peptide would be cleaved, releasing BHQ3 from the CuS nanoparticles, the former of which as a small molecule is then rapidly cleared out from the tumor, whereas the latter of which as large nanoparticles would retain inside the tumor for a much longer period of time. As the result, the PA signal at 680 nm which is contributed by BHQ3 would be quickly diminished while that at 930 nm would be largely retained. The PA signal ratio of 680 nm / 930 nm could thus serve as an in vivo indicator of MMPs activity inside the tumor. Our work presents a novel strategy of in vivo sensing of MMPs based on PA imaging, which should offer remarkably improved detection depth compared with traditional optical imaging techniques. PMID:24465271

  20. Inspection of copper canisters for spent nuclear fuel by means of ultrasound. Phased arrays, ultrasonic imaging and nonlinear acoustics

    Energy Technology Data Exchange (ETDEWEB)

    Stepinski, Tadeusz (ed.); Ping Wu; Wennerstroem, Erik [Uppsala Univ. (Sweden). Signals and Systems

    2004-09-01

    This report contains the research results concerning advanced ultrasound for the inspection of copper canisters for spent nuclear fuel obtained at Signals and Systems, Uppsala University in years 2003/2004. After a short introduction a review of beam forming fundamentals required for proper understanding phased array operation is included. The factors that determine lateral resolution during ultrasonic imaging of flaws in solids are analyzed and results of simulations modelling contact inspection of copper are presented. In the second chapter an improved synthetic aperture imaging (SAI) technique is introduced. The proposed SAI technique is characterized by an enhanced lateral resolution compared with the previously proposed extended synthetic aperture focusing technique (ESAFT). The enhancement of imaging performance is achieved due to more realistic assumption concerning the probability density function of scatterers in the region of interest. The proposed technique takes the form of a two-step algorithm using the result obtained in the first step as a prior for the second step. Final chapter contains summary of our recent experimental and theoretical research on nonlinear ultrasonics of unbounded interfaces. A new theoretical model for rough interfaces is developed, and the experimental results from the copper specimens that mimic contact cracks of different types are presented. Derivation of the theory and selected measurement results are given in appendix.

  1. Anomalous acoustic dispersion in architected microlattice metamaterials

    Science.gov (United States)

    KröDel, Sebastian; Palermo, Antonio; Daraio, Chiara

    The ability to control dispersion in acoustic metamaterials is crucial to realize acoustic filtering and rectification devices as well as perfect imaging using negative refractive index materials. Architected microlattice metamaterials immersed in fluid constitute a versatile platform for achieving such control. We investigate architected microlattice materials able to exploit locally resonant modes of their fundamental building blocks that couple with propagating acoustic waves. Using analytical, numerical and experimental methods we find that such lattice materials show a hybrid dispersion behavior governed by Biot's theory for long wavelengths and multiple scattering theory when wave frequency is close to the resonances of the building block. We identify the relevant geometric parameters to alter and control the group and phase velocities in this class of acoustic metamaterials. Furthermore, we fabricate small-scale acoustic metamaterial samples using high precision SLA additive manufacturing and test the resulting materials experimentally using a customized ultrasonic setup. This work paves the way for new acoustic devices based on microlattice metamaterials.

  2. Fluoride Bridges as Structure-Directing Motifs in 3d-4f Cluster Chemistry

    DEFF Research Database (Denmark)

    Birk, Torben; Pedersen, Kasper; Thuesen, Christian Aa.

    2012-01-01

    The use of kinetically robust chromium(III) fluorido complexes as synthons for mixed 3d-4f clusters is reported. The tendency toward linear {CrIII–F–LnIII} units dictates the cluster topology. Specifically, we show that reaction of cis-[CrIIIF2(NN)2]NO3 (NN = 1,10-phenanthroline (“phen”) or 2......-nuclear complex and fac-[CrIIIF3L′], with L′ = 1,1,1-tris-((methylamino)methylethane) (“Me3tame”), reacts with [Ln(hfac)3(H2O)2] (hfacH = 1,1,1,5,5,5-hexafluoroacetylacetone) to yield an isostructural series of {Ln3Cr2} (10–14) trigonal bipyramids with no central ligand. The formation of the latter is accompanied...... by a partial solvolysis of the Cr(III) precursor but without formation of insoluble LnF3. The magnetic properties of the gadolinium containing clusters allow quantification of fluoride-mediated, antiferromagnetic Gd–Cr exchange interactions of magnitude between 0.14 cm–1 and 0.71 cm–1 (Ĥ = J12Ŝ1·Ŝ2...

  3. Application of Acoustic Radiation Force Impulse (ARFI) Elastography in Imaging of Delayed Onset Muscle Soreness (DOMS): A Comparative Analysis With 3T MRI.

    Science.gov (United States)

    Hotfiel, Thilo; Kellermann, Marion; Swoboda, Bernd; Wildner, Dane; Golditz, Tobias; Grim, Casper; Raithel, Martin; Uder, Michael; Heiss, Rafael

    2017-05-17

    DOMS is one of the most common reasons for impaired muscle performance in sports and is associated with reduced muscle strength and frequently observed both in professional and recreational athletes. To emphasize the diagnostic value of Acoustic Radiation Force Impulse (ARFI) in imaging of Delayed Onset Muscle Soreness by comparing findings to high-resolution 3T MRI T2 weighted sequences. Case series. Laboratory environment. Fifteen healthy students (7 female, 8 male, age 24 ± 4 years, height 178 ± 10 cm, body weight 67 ± 12 kg). ARFI values, represented as shear wave velocities (SWV) of the gastrocnemius muscle (GM) and soleus muscle (SM), as well as conventional ultrasound, high-resolution 3T MRI, creatine kinase activity, extension range of the ankle joint, calf circumference and muscle soreness were assessed before (baseline) and 60 hours after (post-intervention, PI) a standardized eccentric exercise. ARFI SWV values of the GM revealed a statistically significant decrease of 19.1% between baseline (2.2 ± 0.26 m/s) and PI (1.78 ± 0.24 m/s); p = 0.008. At follow-up, the MRI investigations showed intramuscular oedema for the GM in all participants corresponding to a significant raise in T2 signal intensity (p = 0.001) and in T2-time values (p = 0.004). ARFI elastography seems to be an additional sensitive diagnostic modality in the diagnostic work up of DOMS. Intramuscular SWV could represent an additional imaging marker for the assessment and monitoring of ultrastructural muscle injuries and therefore be helpful for individual training composition in elite sports.

  4. Non-intrusive telemetry applications in the oilsands: from visible light and x-ray video to acoustic imaging and spectroscopy

    Science.gov (United States)

    Shaw, John M.

    2013-06-01

    While the production, transport and refining of oils from the oilsands of Alberta, and comparable resources elsewhere is performed at industrial scales, numerous technical and technological challenges and opportunities persist due to the ill defined nature of the resource. For example, bitumen and heavy oil comprise multiple bulk phases, self-organizing constituents at the microscale (liquid crystals) and the nano scale. There are no quantitative measures available at the molecular level. Non-intrusive telemetry is providing promising paths toward solutions, be they enabling technologies targeting process design, development or optimization, or more prosaic process control or process monitoring applications. Operation examples include automated large object and poor quality ore during mining, and monitoring the thickness and location of oil water interfacial zones within separation vessels. These applications involve real-time video image processing. X-ray transmission video imaging is used to enumerate organic phases present within a vessel, and to detect individual phase volumes, densities and elemental compositions. This is an enabling technology that provides phase equilibrium and phase composition data for production and refining process development, and fluid property myth debunking. A high-resolution two-dimensional acoustic mapping technique now at the proof of concept stage is expected to provide simultaneous fluid flow and fluid composition data within porous inorganic media. Again this is an enabling technology targeting visualization of diverse oil production process fundamentals at the pore scale. Far infrared spectroscopy coupled with detailed quantum mechanical calculations, may provide characteristic molecular motifs and intermolecular association data required for fluid characterization and process modeling. X-ray scattering (SAXS/WAXS/USAXS) provides characteristic supramolecular structure information that impacts fluid rheology and process

  5. Acoustic Radiation Force Impulse Imaging for the Differentiation of Benign and Malignant Lymph Nodes: A Systematic Review and Meta-Analysis.

    Science.gov (United States)

    Zhang, Peige; Zhang, Li; Zheng, Shaoping; Yu, Cheng; Xie, Mingxing; Lv, Qing

    2016-01-01

    To evaluate the overall performance of acoustic radiation force impulse imaging (ARFI) in differentiating between benign and malignant lymph nodes (LNs) by conducting a meta-analysis. PubMed, Embase, Web of Science, the Cochrane Library and the China National Knowledge Infrastructure were comprehensively searched for potential studies through August 13th, 2016. Studies that investigated the diagnostic power of ARFI for the differential diagnosis of benign and malignant LNs by using virtual touch tissue quantification (VTQ) or virtual touch tissue imaging quantification (VTIQ) were collected. The included articles were published in English or Chinese. Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) was used to evaluate the methodological quality. The pooled sensitivity, specificity, and the area under the summary receiver operating characteristic (SROC) curve (AUC) were calculated by means of a bivariate mixed-effects regression model. Meta-regression analysis was performed to identify the potential sources of between study heterogeneity. Fagan plot analysis was used to explore the clinical utilities. Publication bias was assessed using Deek's funnel plot. Nine studies involving 1084 LNs from 929 patients were identified to analyze in the meta-analysis. The summary sensitivity and specificity of ARFI in detecting malignant LNs were 0.87 (95% confidence interval [CI], 0.83-0.91) and 0.88 (95% CI, 0.82-0.92), respectively. The AUC was 0.93 (95% CI, 0.90-0.95). The pooled DOR was 49.59 (95% CI, 26.11-94.15). Deek's funnel plot revealed no significant publication bias. ARFI is a promising tool for the differentiation of benign and malignant LNs with high sensitivity and specificity.

  6. [Contrastive study on conventional ultrasound, compression elastography and acoustic radiation force impulse imaging in the differential diagnosis of benign and malignant breast tumors].

    Science.gov (United States)

    Zhang, Lu; Zhou, Ping; Deng, Jin; Tian, Shuangming; Qian, Ying; Wu, Xiaomin; Ma, Shuhua; Li, Jiale

    2014-12-01

    To evaluate the diagnostic performance of conventional ultrasound, compression elastography (CE) and acoustic radiation force impulse imaging (ARFI) in differential diagnosis of benign and malignant breast tumors. A total of 98 patients with liver lesions were included in the study. The images of conventional ultrasound, CE and the values of virtual touch tissue quantification (VTQ) of breast lesions were obtained. The diagnostic performance of conventional ultrasound, CE and ARFI were assessed by using pathology as the gold standard, and then evaluate the diagnosis efficiency of these three approaches in differential diagnosing benign and malignant breast tumors. The specificity, sensitivity and accuracy in the diagnosis of malignant breast tumors for conventional ultrasound were 80.0%, 81.1% and 81.7%, respectively, whereas for CE elastic score were 85.7%, 86.7% and 86.3%, respectively. With a cutoff value of 3.71 for the SR, the sensitivity, specificity, accuracy in diagnosis of malignant breast tumors were 97.1%, 83.3% and 88.4%, respectively. With a cutoff value of 3.78 m/s for VTQ, the sensitivity, specificity, accuracy in diagnosis of malignant breast tumors were 94.3%, 91.7% and 92.6%, respectively. The difference in diagnosis efficiency among ARFI, CE and conventional ultrasound in differential diagnosis of benign and malignant breast tumors was significant (Pbenign and malignant breast tumors. But the diagnosis efficiency of ARFI is superior to CE and conventional ultrasound. The three approaches can help each other in differential diagnosis of benign and malignant breast tumors.

  7. Implementation and Comparison of Acoustic Travel-Time Measurement Procedures for the Solar Dynamics Observatory-Helioseismic and Magnetic Imager Time-Distance Helioseismology Pipeline

    Science.gov (United States)

    Couvidat, S.; Zhao, J.; Birch, A. C.; Kosovichev, A. G.; Duvall, Thomas L., Jr.; Parchevsky, K.; Scherrer, P. H.

    2010-01-01

    The Helioseismic and Magnetic Imager (HMI) instrument onboard the Solar Dynamics Observatory (SDO) satellite is designed to produce high-resolution Doppler-velocity maps of oscillations at the solar surface with high temporal cadence. To take advantage of these high-quality oscillation data, a time - distance helioseismology pipeline (Zhao et al., Solar Phys. submitted, 2010) has been implemented at the Joint Science Operations Center (JSOC) at Stanford University. The aim of this pipeline is to generate maps of acoustic travel times from oscillations on the solar surface, and to infer subsurface 3D flow velocities and sound-speed perturbations. The wave travel times are measured from cross-covariances of the observed solar oscillation signals. For implementation into the pipeline we have investigated three different travel-time definitions developed in time - distance helioseismology: a Gabor-wavelet fitting (Kosovichev and Duvall, SCORE'96: Solar Convection and Oscillations and Their Relationship, ASSL, Dordrecht, 241, 1997), a minimization relative to a reference cross-covariance function (Gizon and Birch, Astrophys. J. 571, 966, 2002), and a linearized version of the minimization method (Gizon and Birch, Astrophys. J. 614, 472, 2004). Using Doppler-velocity data from the Michelson Doppler Imager (MDI) instrument onboard SOHO, we tested and compared these definitions for the mean and difference traveltime perturbations measured from reciprocal signals. Although all three procedures return similar travel times in a quiet-Sun region, the method of Gizon and Birch (Astrophys. J. 614, 472, 2004) gives travel times that are significantly different from the others in a magnetic (active) region. Thus, for the pipeline implementation we chose the procedures of Kosovichev and Duvall (SCORE'96: Solar Convection and Oscillations and Their Relationship, ASSL, Dordrecht, 241, 1997) and Gizon and Birch (Astrophys. J. 571, 966, 2002). We investigated the relationships among

  8. Implementation and Comparison of Acoustic Travel-Time Measurement Procedures for the Helioseismic and Magnetic Imager Time-Distance Helioseismology Pipeline

    Science.gov (United States)

    Couvidat, S.; Zhao, J.; Birch, A. C.; Kosovichev, A. G.; Duvall, T. L., Jr.; Parchevsky, K.; Scherrer, P. H.

    2009-01-01

    The Helioseismic and Magnetic Imager (HMI) instrument on board the Solar Dynamics Observatory (SDO) satellite is designed to produce high-resolution Doppler velocity maps of oscillations at the solar surface with high temporal cadence. To take advantage of these high-quality oscillation data, a time-distance helioseismology pipeline has been implemented at the Joint Science Operations Center (JSOC) at Stanford University. The aim of this pipeline is to generate maps of acoustic travel times from oscillations on the solar surface, and to infer subsurface 3D flow velocities and sound-speed perturbations. The wave travel times are measured from cross covariances of the observed solar oscillation signals. For implementation into the pipeline we have investigated three different travel-time definitions developed in time-distance helioseismology: a Gabor wavelet fitting (Kosovichev and Duvall, 1997), a minimization relative to a reference cross-covariance function (Gizon and Birch, 2002), and a linearized version of the minimization method (Gizon and Birch, 2004). Using Doppler velocity data from the Michelson Doppler Imager (MDI) instrument on board SOHO, we tested and compared these definitions for the mean and difference travel-time perturbations measured from reciprocal signals. Although all three procedures return similar travel times in a quiet Sun region, the method of Gizon and Birch (2004) gives travel times that are significantly different from the others in a magnetic (active) region. Thus, for the pipeline implementation we chose the procedures of Kosovichev and Duvall (1997) and Gizon and Birch (2002). We investigated the relationships among these three travel-time definitions, their sensitivities to fitting parameters, and estimated the random errors they produce

  9. Cloning, sequence analysis, and expression of the large subunit of the human lymphocyte activation antigen 4F2

    International Nuclear Information System (INIS)

    Lumadue, J.A.; Glick, A.B.; Ruddle, F.H.

    1987-01-01

    Among the earliest expressed antigens on the surface of activated human lymphocytes is the surface antigen 4F2. The authors have used DNA-mediated gene transfer and fluorescence-activated cell sorting to obtain cell lines that contain the gene encoding the large subunit of the human 4F2 antigen in a mouse L-cell background. Human DNAs cloned from these cell lines were subsequently used as hybridization probes to isolate a full-length cDNA clone expressing 4F2. Sequence analysis of the coding region has revealed an amino acid sequence of 529 residues. Hydrophobicity plotting has predicted a probable structure for the protein that includes an external carboxyl terminus, an internal leader sequence, a single hydrophobic transmembrane domain, and two possible membrane-associated domains. The 4F2 cDNA detects a single 1.8-kilobase mRNA in T-cell and B-cell lines. RNA gel blot analysis of RNA derived from quiescent and serum-stimulated Swiss 3T3 fibroblasts reveals a cell-cycle modulation of 4F2 gene expression: the mRNA is present in quiescent fibroblasts but increases 8-fold 24-36 hr after stimulation, at the time of maximal DNA synthesis

  10. Cloning, sequence analysis, and expression of the large subunit of the human lymphocyte activation antigen 4F2

    Energy Technology Data Exchange (ETDEWEB)

    Lumadue, J.A.; Glick, A.B.; Ruddle, F.H.

    1987-12-01

    Among the earliest expressed antigens on the surface of activated human lymphocytes is the surface antigen 4F2. The authors have used DNA-mediated gene transfer and fluorescence-activated cell sorting to obtain cell lines that contain the gene encoding the large subunit of the human 4F2 antigen in a mouse L-cell background. Human DNAs cloned from these cell lines were subsequently used as hybridization probes to isolate a full-length cDNA clone expressing 4F2. Sequence analysis of the coding region has revealed an amino acid sequence of 529 residues. Hydrophobicity plotting has predicted a probable structure for the protein that includes an external carboxyl terminus, an internal leader sequence, a single hydrophobic transmembrane domain, and two possible membrane-associated domains. The 4F2 cDNA detects a single 1.8-kilobase mRNA in T-cell and B-cell lines. RNA gel blot analysis of RNA derived from quiescent and serum-stimulated Swiss 3T3 fibroblasts reveals a cell-cycle modulation of 4F2 gene expression: the mRNA is present in quiescent fibroblasts but increases 8-fold 24-36 hr after stimulation, at the time of maximal DNA synthesis.

  11. PLASMA DIAGNOSTIC POTENTIAL OF 2p4f IN N{sup +}—ACCURATE WAVELENGTHS AND OSCILLATOR STRENGTHS

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Xiaozhi [School of Physics Science and Nuclear Energy Engineering, Beihang University, Beijing 100191 (China); Li, Jiguang; Wang, Jianguo [Data Center for High Energy Density Physics, Institute of Applied Physics and Computational Mathematics, P.O. Box 8009, Beijing 100088 (China); Jönsson, Per, E-mail: Li_Jiguang@iapcm.ac.cn [Materials Science and Applied Mathematics, Malmö University, SE-20506 Malmö (Sweden)

    2015-03-10

    Radiative emission lines from nitrogen and its ions are often observed in nebula spectra, where the N{sup 2+} abundance can be inferred from lines of the 2p4f configuration. In addition, intensity ratios between lines of the 2p3p-2p3s and 2p4f-2p3d transition arrays can serve as temperature diagnostics. To aid abundance determinations and plasma diagnostics, wavelengths and oscillator strengths were calculated with high precision for electric dipole (E1) transitions from levels in the 2p4f configuration of N{sup +}. Electron correlation and relativistic effects, including the Breit interaction, were systematically taken into account within the framework of the multiconfiguration Dirac-Hartree-Fock method. Except for the 2p4f-2p4d transitions with quite large wavelengths and the two-electron-one-photon 2p4f-2s2p {sup 3} transitions, the uncertainties of the present calculations were controlled to within 3% and 5% for wavelengths and oscillator strengths, respectively. We also compared our results with other theoretical and experimental values when available. Discrepancies were found between our calculations and previous calculations due to the neglect of relativistic effects in the latter.

  12. Imaging sciences workshop

    Energy Technology Data Exchange (ETDEWEB)

    Candy, J.V.

    1994-11-15

    This workshop on the Imaging Sciences sponsored by Lawrence Livermore National Laboratory contains short abstracts/articles submitted by speakers. The topic areas covered include the following: Astronomical Imaging; biomedical imaging; vision/image display; imaging hardware; imaging software; Acoustic/oceanic imaging; microwave/acoustic imaging; computed tomography; physical imaging; imaging algorithms. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.

  13. Uniaxial experimental study of the acoustic emission and deformation behavior of composite rock based on 3D digital image correlation (DIC)

    Science.gov (United States)

    Cheng, Jian-Long; Yang, Sheng-Qi; Chen, Kui; Ma, Dan; Li, Feng-Yuan; Wang, Li-Ming

    2017-12-01

    In this paper, uniaxial compression tests were carried out on a series of composite rock specimens with different dip angles, which were made from two types of rock-like material with different strength. The acoustic emission technique was used to monitor the acoustic signal characteristics of composite rock specimens during the entire loading process. At the same time, an optical non-contact 3D digital image correlation technique was used to study the evolution of axial strain field and the maximal strain field before and after the peak strength at different stress levels during the loading process. The effect of bedding plane inclination on the deformation and strength during uniaxial loading was analyzed. The methods of solving the elastic constants of hard and weak rock were described. The damage evolution process, deformation and failure mechanism, and failure mode during uniaxial loading were fully determined. The experimental results show that the θ = 0{°}-45{°} specimens had obvious plastic deformation during loading, and the brittleness of the θ = 60{°}-90{°} specimens gradually increased during the loading process. When the anisotropic angle θ increased from 0{°} to 90{°}, the peak strength, peak strain, and apparent elastic modulus all decreased initially and then increased. The failure mode of the composite rock specimen during uniaxial loading can be divided into three categories: tensile fracture across the discontinuities (θ = 0{°}-30{°}), sliding failure along the discontinuities (θ = 45{°}-75{°}), and tensile-split along the discontinuities (θ = 90{°}). The axial strain of the weak and hard rock layers in the composite rock specimen during the loading process was significantly different from that of the θ = 0{°}-45{°} specimens and was almost the same as that of the θ = 60{°}-90{°} specimens. As for the strain localization highlighted in the maximum principal strain field, the θ = 0{°}-30{°} specimens appeared in the rock

  14. Determination of 4f energy levels for trivalent lanthanide ions in YAlO{sub 3} by X-ray photoelectron spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, Yuhei; Ueda, Kazushige, E-mail: kueda@che.kyutech.ac.jp

    2016-09-01

    A simple method to analyze 4f energy levels of trivalent lanthanide (Ln) ions was demonstrated by conventional X-ray photoelectron spectroscopy (XPS) measurements using Ln ions doped YAlO{sub 3} sintered polycrystalline samples. Although XPS peaks derived from Ln 4f states overlapped with the host's valence band consisting of O 2p states, the difference XPS spectra between Ln doped and non-doped samples showed only the Ln 4f peaks due to the large difference of photoionization cross sections between Ln 4f and O 2p orbitals. The difference spectra showing Ln 4f states were aligned at the valence band maximum (VBM) making use of the peaks of Al 2p inner shells, and the Ln{sup 3+} 4f energy levels referred to the VBM were determined from the Ln{sup 3+} 4f peak energies. The Ln{sup 3+} 4f energy levels obtained by this simple method were in good agreement with those previously obtained by resonant ultraviolet photoelectron spectroscopy measurements using single crystal samples. - Highlights: • Lanthanide (Ln) 4f energy in YAlO{sub 3} was studied by X-ray photoelectron spectroscopy. • The method used differences in photoionization probability between Ln 4f and O 2p. • Ln 4f states were obtained by difference spectra between Ln- and non-doped samples. • Obtained 4f energy levels agreed with those reported by a sophisticated method.

  15. Acoustic Neuroma Association

    Science.gov (United States)

    ... EVENTS DONATE NEWS Home Learn Back Learn about acoustic neuroma AN Facts What is acoustic neuroma? Diagnosing ... Brain Freeze ? READ MORE Read More What is acoustic neuroma? Identifying an AN Learn More Get Info ...

  16. MR of acoustic neuromas

    International Nuclear Information System (INIS)

    Suzuki, Masayuki; Takashima, Tsutomu; Kadoya, Masumi; Takahashi, Shiroh; Miyayama, Shiroh; Taira, Sakae; Kashihara, Kengo; Yamashima, Tetsumori; Itoh, Haruhide

    1989-01-01

    In this report, the relationship of acoustic neuromas to the adjacent cranial nerves is discussed. On T 1 -weighted images, the trigeminal nerve was detected in all 13 cases. Mild to marked compression of these nerves by the tumors was observed in eight cases. The extent of compression did not always correspond to the clinical symptoms. In four cases with a maximum tumor diameter of 2 cm or less, the 7th and 8th cranial nerves were identified. There was no facial palsy in these patients. Two patients with a tumor diameter of more than 2 cm also had no facial palsy. All patients, including those with small tumors, complained of hearing loss and/or tinnitus. While MR imaging has some limitations, it is an effective imaging modality for showing the relationship between tumors and nerves. (author)

  17. Oscillating acoustic streaming jet

    International Nuclear Information System (INIS)

    Moudjed, Brahim; Botton, Valery; Henry, Daniel; Millet, Severine; Ben Hadid, Hamda; Garandet, Jean-Paul

    2014-01-01

    The present paper provides the first experimental investigation of an oscillating acoustic streaming jet. The observations are performed in the far field of a 2 MHz circular plane ultrasound transducer introduced in a rectangular cavity filled with water. Measurements are made by Particle Image Velocimetry (PIV) in horizontal and vertical planes near the end of the cavity. Oscillations of the jet appear in this zone, for a sufficiently high Reynolds number, as an intermittent phenomenon on an otherwise straight jet fluctuating in intensity. The observed perturbation pattern is similar to that of former theoretical studies. This intermittently oscillatory behavior is the first step to the transition to turbulence. (authors)

  18. Elastic and inelastic neutron scattering studies on 3d and 4f magnetic compounds

    International Nuclear Information System (INIS)

    Erkelens, W.A.C.

    1987-01-01

    First, some theoretical aspects of neutron scattering techniques are given, and the cyrogenic equipment and the neutron spectrometers employed are described. Experiments on a 3-d Ising system are described, performed at very low temperatures and in a magnetic field. Experimental proof has been obtained for the theoretical prediction that the critical behaviour of a d-dimensional Ising system in a transverse magnetic field near T=0 is identical to that of a d+1 dimensional Ising system as a function of temperature in zero field. Experiments are described on a Ni 2+ compound which represents a good example of a 1-d antiferromagnetic Heisenberg (HAF), spin s=1, system. The results give evidence for the so called 'Haldane conjecture', a theory which predicts that the ground state of HAF systems with integer spin is a nonmagnetic many-body singlet. The excited states are separated from the ground state by an energy gap. Contrastingly, half-integer spin systems are predicted to have no such gap. A short introduction is given to phenomena in rare earth, 4f compunds, like the Kondo effect and heavy fermion behaviour. Experimental results on the RE hexaborides are reported, among which CeB 6 , a typical Kondo system with complex magnetic orderings. Furthermore, inelastic neutron scattering experiments on NdB 6 and CeB 6 , performed in order to get insight in the various reaction mechanisms, are presented. Finally a report is given on magnetic correlations and excitations in two nonmagnetically ordered heavy fermion compounds, CeCu 6 and CeRu 2 Si 2 and their interpretation in the light of existing theories. 201 refs.; 61 figs.; 4 tabs

  19. 4F CROPS: Future crops for food, feed, fibre and fuel

    Energy Technology Data Exchange (ETDEWEB)

    E. Alexopoulou, E.; Christou, M.; Eleftheriadis, I. [Center for Renewable Energy Sources (CRES), Pikermi Attikis (Greece)

    2008-07-01

    As different sectors - food, feed, fiber, and fuels - compete for land, the yielding potential of the future non-food crops has to be as efficient as possible in order to minimize the competition for land. The main objective of 4F CROPS project is to survey and analyze all the parameters that will play an important role in successful non-food cropping systems in the agriculture of EU27 alongside the existing food crop systems. The work will start with the prediction of the future land use in short term (2020) and long term (2030), taking under consideration restrict factors for agriculture and the market demand for non-food crops. The cropping possibilities based on regional potential levels, ecology and climate will be determined. This group of non-food crops will be then subjected to a comparative cost analysis with conventional crops for the same time framework. Socio-economic impacts, like farmers' income, rural development, public development, and public acceptance will analyze. Then environmental implications will be assessed compared to their respective conventional products (fossil energy, conversional materials). Several environmental impacts will be assessed like soil quality and soil erosion, air quality and climate change, water issues, biodiversity and landscape by using LCA and EIE methods. The regulatory framework of the non-food crops will be considered including existing policies, co-existence and safety measures when the crops used for both food and non-food crops. All the collected information will be used for the formation of scenarios for successful non-food cropping alongside food cropping systems answering whether a completive bioeconomy is a viable option for EU27.

  20. Isotope Shifts and Hyperfine Structure in the[Xe]4f(7)5d 6s(2) D-2(J)->[Xe]4f(7)5d 6s 6p F-9(J+1) Transitions of Gadolinium

    International Nuclear Information System (INIS)

    Blaum, K.; Bushaw, Bruce A.; Diel, S; Geppert, Ch; Kuschnick, A; Muller, P.; Nortershauser, W.; Schmitt, A.; Wendt, K.

    1999-01-01

    High-resolution resonance ionization mass spectrometry has been used to measure isotope shifts and hyperfine structure in all[Xe] 4f 7 5d 6s2 9DJ ---[Xe] 4f 7 5d 6s 6p 9FJ+1 (J= 2-6) and the[Xe] 4f 7 5d 6s2 9D6---[Xe] 4f 7 5d 6s 6p 9D5 transitions of gadolinium (Gd I). Gadolinium atoms in an atomic beam were excited with a tunable single-frequency laser in the wavelength range of 422 - 429 nm. Resonant excitation was followed by photoionization with the 363.8 nm line of an argon ion laser and resulting ions were mass separated and detected with a quadrupole mass spectrometer. Isotope shifts for all stable gadolinium isotopes in these transitions have been measured for the first time. Additionally, the hyperfine structure constants of the upper states have been derived for the isotopes 155, 157Gd and are compared with previous work. Using prior experimental values for the mean nuclear charge radii, derived from the combination of muonic atoms and electron scattering data, field shift a nd specific mass shift coefficients for the investigated transitions have been determined and nuclear charge parameters l for the minor isotopes 152, 154Gd have been calculated

  1. Panel acoustic contribution analysis.

    Science.gov (United States)

    Wu, Sean F; Natarajan, Logesh Kumar

    2013-02-01

    Formulations are derived to analyze the relative panel acoustic contributions of a vibrating structure. The essence of this analysis is to correlate the acoustic power flow from each panel to the radiated acoustic pressure at any field point. The acoustic power is obtained by integrating the normal component of the surface acoustic intensity, which is the product of the surface acoustic pressure and normal surface velocity reconstructed by using the Helmholtz equation least squares based nearfield acoustical holography, over each panel. The significance of this methodology is that it enables one to analyze and rank relative acoustic contributions of individual panels of a complex vibrating structure to acoustic radiation anywhere in the field based on a single set of the acoustic pressures measured in the near field. Moreover, this approach is valid for both interior and exterior regions. Examples of using this method to analyze and rank the relative acoustic contributions of a scaled vehicle cabin are demonstrated.

  2. Acoustic Imaging of Selected Areas of Gdansk Bay with the Aid of Parametric Echosounder and Side-Scan Sonar

    Directory of Open Access Journals (Sweden)

    Grelowska Grażyna

    2017-12-01

    Full Text Available The article presents and analyses the data recorded during sounding of the Gdansk Bay seabed with the aid of a parametric echosounder and a side-scan sonar. The accuracy of seabed structure examination, as a condition for obtaining valuable results, requires correct configuration of echolocation devices and proper calibration of peripheral devices, such as the survey unit geographical position sensor - GPS, the navigation unit, the MRU-Z sensor of pitch, roll and heave, and the sound velocity meter, which deliver the data to the bathymetric measurement system. Parametric seabed profilers deliver two types of data: the envelope, and the detailed echo signal without processing. The envelope is used for data visualisation in the form of online echograms, while the echo signal is stored for further analyses, to be performed using dedicated software or, after relevant conversion, in arbitrary programming environment1. The presented data analysis is illustrated by selected sample images recorded by the parametric echosounder and the side-scan sonar during Gdansk Bay sounding.

  3. Acoustic radiation force impulse-imaging and transient elastography for non-invasive assessment of liver fibrosis and steatosis in NAFLD

    International Nuclear Information System (INIS)

    Friedrich-Rust, Mireen; Romen, Daniela; Vermehren, Johannes; Kriener, Susanne; Sadet, Dilek; Herrmann, Eva; Zeuzem, Stefan; Bojunga, Joerg

    2012-01-01

    Background: Transient elastography (TE) and acoustic radiation force impulse (ARFI)-imaging have shown promising results for the staging of liver fibrosis. Aim: The aim of the present study was to compare ARFI of the left and right liver lobe with TE using the standard and obese probes for the diagnosis of liver fibrosis in NAFL/NASH. In addition, liver steatosis is evaluated using the novel controlled attenuation parameter (CAP). Methods: Sixty-one patients with NAFLD/NASH were included in the study. All patients received TE with both probes, ARFI of both liver lobes and CAP. The results were compared with liver histology. Results: 57 patients were included in the final analysis. The diagnostic accuracy for TE measurements with the M-and XL-probe and for ARFI of the right and left liver lobe was 0.73, 0.84, 0.71 and 0.60 for the diagnosis of severe fibrosis, and 0.93, 0.93, 0.74 and 0.90 for the diagnosis of cirrhosis, respectively. No significant difference of results was observed between TE and ARFI in the subgroup of patients with reliable TE-measurement when taking into account the best results of both methods. However, while a significant correlation could be found for TE with histological liver fibrosis, the correlation of ARFI with liver fibrosis was not statistically significant. A significant correlation was found for CAP with histological steatosis (r = 0.49, p < 0.001). Conclusions: No significant difference in diagnostic accuracy for the non-invasive assessment of liver fibrosis was found for transient elastography and ARFI. Nevertheless TE significantly correlated with liver fibrosis while ARFI did not. CAP enables the non-invasive assessment of steatosis.

  4. CLEC4F is an inducible C-type lectin in F4/80-positive cells and is involved in alpha-galactosylceramide presentation in liver.

    Directory of Open Access Journals (Sweden)

    Chih-Ya Yang

    Full Text Available CLEC4F, a member of C-type lectin, was first purified from rat liver extract with high binding affinity to fucose, galactose (Gal, N-acetylgalactosamine (GalNAc, and un-sialylated glucosphingolipids with GalNAc or Gal terminus. However, the biological functions of CLEC4F have not been elucidated. To address this question, we examined the expression and distribution of murine CLEC4F, determined its binding specificity by glycan array, and investigated its function using CLEC4F knockout (Clec4f-/- mice. We found that CLEC4F is a heavily glycosylated membrane protein co-expressed with F4/80 on Kupffer cells. In contrast to F4/80, CLEC4F is detectable in fetal livers at embryonic day 11.5 (E11.5 but not in yolk sac, suggesting the expression of CLEC4F is induced as cells migrate from yolk cells to the liver. Even though CLEC4F is not detectable in tissues outside liver, both residential Kupffer cells and infiltrating mononuclear cells surrounding liver abscesses are CLEC4F-positive upon Listeria monocytogenes (L. monocytogenes infection. While CLEC4F has strong binding to Gal and GalNAc, terminal fucosylation inhibits CLEC4F recognition to several glycans such as Fucosyl GM1, Globo H, Bb3∼4 and other fucosyl-glycans. Moreover, CLEC4F interacts with alpha-galactosylceramide (α-GalCer in a calcium-dependent manner and participates in the presentation of α-GalCer to natural killer T (NKT cells. This suggests that CLEC4F is a C-type lectin with diverse binding specificity expressed on residential Kupffer cells and infiltrating monocytes in the liver, and may play an important role to modulate glycolipids presentation on Kupffer cells.

  5. Temperature dependence of spin and orbital magnetic moments of Sm 4f electrons in (Sm, Gd)Al2

    International Nuclear Information System (INIS)

    Qiao, S.; Kimura, A.; Adachi, H.; Iori, K.; Miyamoto, K.; Xie, T.; Namatame, H.; Taniguchi, M.; Tanaka, A.; Muro, T.; Imada, S.; Suga, S.

    2005-01-01

    X-ray magnetic circular dichroism studies were carried out on (Sm, Gd)Al 2 , a ferromagnet without net magnetization at a certain compensation temperature. For Sm 4f electrons, the following understandings were obtained: the magnitude of expectation value of orbital magnetic moment (m L Sm ) is always larger than that of spin one (m S Sm ), so the cancellation of total spin and orbital magnetic moments cannot be achieved only by Sm 4f electrons and the contributions from Gd ions and conduction electrons are important; when the temperature decreases, the magnitude of both m L Sm and m S Sm increases and the gross magnetic moment due to the Sm 4f electrons monotonically deviates from zero. These results tell us that the temperature dependence of magnetic moments related with the electrons other than Sm 4f ones may play important roles in the subtle adjustment of the total spin and orbital magnetic moments to the zero magnetization at the compensation temperature

  6. R&D studies of a RICH detector using pressurized C$_{4}$F$_{8}$O radiator gas and a CsI-based gaseous photon detector

    CERN Document Server

    Agócs, A.G; Barnaföldi, G.G; Bellwied, R; Bencédi, G; Bencze, G; Berényi, D; Boldizsár, L; Chattopadhyay, S; Chinellato, D.D; Cindolo, F; Das-Bose, L; Das, D; Das, K; De Cataldo, G; Di Bari, D; Di Mauro, A; Futó, E; Garcia, E; Hamar, G; Harton, A; Jimenez, R.T; Kim, D.W; Kim, J.S; Knospe, A; Kovacs, L; Lévai, P; Markert, C; Martinengo, P; Molnar, L; Nappi, E; Olah, L; Paic, G; Pastore, C; Patino, M.E; Peskov, V; Pinsky, L; Piuz, F; Pochybova, S; Sgura, I; Sinha, T; Song, J; Timmins, A; Van Beelen, J.B; Varga, D; Volpe, G; Weber, M; Xaplanteris, L; Yi, J; Yoo, I.-K

    2013-01-01

    We report on studies of layout and performance of a new Ring Imaging Cherenkov detector using for the fi rst time pressurized C 4 F 8 O radiator gas and a photon detector consisting of a MWPC equipped with a CsI photocathode. In particular, we present here the results of beam tests of a MWPC having an adjustable anode – cathode gap, aiming at the optimization of single photoelectron detection and Cherenkov angle resolution. This system was proposed as a Very High Momentum Particle Identi fi cation (VHMPID) upgrade for the ALICE experiment at LHC to provide charged hadron track-by-track identi fi cation in the momentum range 5 – 25 GeV/c.

  7. Acoustics and Hearing

    CERN Document Server

    Damaske, Peter

    2008-01-01

    When one listens to music at home, one would like to have an acoustic impression close to that of being in the concert hall. Until recently this meant elaborate multi-channelled sound systems with 5 or more speakers. But head-related stereophony achieves the surround-sound effect in living rooms with only two loudspeakers. By virtue of their slight directivity as well as an electronic filter the limitations previously common to two-speaker systems can be overcome and this holds for any arbitrary two-channel recording. The book also investigates the question of how a wide and diffuse sound image can arise in concert halls and shows that the quality of concert halls decisively depends on diffuse sound images arising in the onset of reverberation. For this purpose a strong onset of reverberation is modified in an anechoic chamber by electroacoustic means. Acoustics and Hearing proposes ideas concerning signal processing in the auditory system that explain the measured results and the resultant sound effects plea...

  8. Formation of tavorite-type LiFeSO4F followed by in situ X-ray diffraction

    Science.gov (United States)

    Eriksson, Rickard; Sobkowiak, Adam; Ångström, Jonas; Sahlberg, Martin; Gustafsson, Torbjörn; Edström, Kristina; Björefors, Fredrik

    2015-12-01

    The tavorite-type polymorph of LiFeSO4F has recently attracted substantial attention as a positive electrode material for lithium ion batteries. The synthesis of this material is generally considered to rely on a topotactic exchange of water (H2O) for lithium (Li) and fluorine (F) within the structurally similar hydrated iron sulfate precursor (FeSO4·H2O) when reacted with lithium fluoride (LiF). However, there have also been discussions in the literature regarding the possibility of a non-topotactic reaction mechanism between lithium sulfate (Li2SO4) and iron fluoride (FeF2) in tetraethylene glycol (TEG) as reaction medium. In this work, we use in situ X-ray diffraction to continuously follow the formation of LiFeSO4F from the two suggested precursor mixtures in a setup aimed to mimic the conditions of a solvothermal autoclave synthesis. It is demonstrated that LiFeSO4F is formed directly from FeSO4·H2O and LiF, in agreement with the proposed topotactic mechanism. The Li2SO4 and FeF2 precursors, on the other hand, are shown to rapidly transform into FeSO4·H2O and LiF with the water originating from the highly hygroscopic TEG before a subsequent formation of LiFeSO4F is initiated. The results highlight the importance of the FeSO4·H2O precursor in obtaining the tavorite-type LiFeSO4F, as it is observed in both reaction routes.

  9. Synthesis and structural characterization of the hexagonal anti-perovskite Na{sub 2}CaVO{sub 4}F

    Energy Technology Data Exchange (ETDEWEB)

    Green, Robert L., E-mail: rgreen@flpoly.org [Chemistry, Florida Polytechnic University, Lakeland, FL 33805 (United States); Avdeev, Maxim [Australian Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232 (Australia); School of Chemistry, The University of Sydney, Sydney, NSW 2006 (Australia); Vogt, Thomas [NanoCenter and Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC 29208 (United States)

    2017-06-15

    The structural details of the ordered hexagonal oxyfluoride Na{sub 2}CaVO{sub 4}F prepared by solid-state synthesis using stoichiometric amounts of V{sub 2}O{sub 5}, CaCO{sub 3}, Na{sub 2}CO{sub 3} and NaF were characterized using high-resolution neutron powder diffraction. The structural changes between 25 °C and 750 °C revealed that the two structural subunits in this material behave different when heated: there is an expansion of the face-shared FNa{sub 4}Ca{sub 2} octahedra while the VO{sub 4} tetrahedra due to increased thermal disorder reveal marginal bond contractions. Bond valences and the global instability index point to significant structural disorder at 750 °C. - Graphical abstract: The structure of the novel oxyfluoride Na{sub 2}CaVO{sub 4}F is studied at room temperature and high-temperatures. The structure can be viewed as layers of compression and elongation of polyhedral subunits, which change as a function of temperature. - Highlights: • The novel oxyfluoride, Na{sub 2}CaVO{sub 4}F, is synthesized via solid-state method. • High-resolution neutron diffraction data is used to analyze the structure of Na{sub 2}CaVO{sub 4}F. • Structural subunits exhibit expansion and contraction with increasing temperature. • Higher temperatures increase instability within the structure of Na{sub 2}CaVO{sub 4}F.

  10. Acoustic transducer

    Science.gov (United States)

    Drumheller, Douglas S.

    2000-01-01

    An active acoustic transducer tool for use down-hole applications. The tool includes a single cylindrical mandrel including a shoulder defining the boundary of a narrowed portion over which is placed a sandwich-style piezoelectric tranducer assembly. The piezoelectric transducer assembly is prestressed by being placed in a thermal interference fit between the shoulder of the mandrel and the base of an anvil which is likewise positioned over the narrower portion of the mandrel. In the preferred embodiment, assembly of the tool is accomplished using a hydraulic jack to stretch the mandrel prior to emplacement of the cylindrical sandwich-style piezoelectric transducer assembly and anvil. After those elements are positioned and secured, the stretched mandrel is allowed to return substantially to its original (pre-stretch) dimensions with the result that the piezoelectric transducer elements are compressed between the anvil and the shoulder of the mandrel.

  11. Acoustic cryocooler

    International Nuclear Information System (INIS)

    Swift, G.W.; Martin, R.A.; Radebaugh, R.

    1990-01-01

    This patent describes an acoustic cryocooler with no moving parts is formed from a thermoacoustic driver (TAD) driving a pulse tube refrigerator (PTR) through a standing wave tube. Thermoacoustic elements in the TAD are spaced apart a distance effect to accommodate the increased thermal penetration length arising from the relatively low TAD operating frequency in the range of 15--60 Hz. At these low operating frequencies, a long tube is required to support the standing wave. The tube may be coiled to reduce the overall length of the cryocooler. One or two PTR's are located on the standing wave tube adjacent antinodes in the standing wave to be driven by the standing wave pressure oscillations. It is predicted that a heat input of 1000 W at 1000 K will maintain a cooling load of 5 W at 80 K

  12. Use of acoustic vortices in acoustic levitation

    DEFF Research Database (Denmark)

    Cutanda Henriquez, Vicente; Santillan, Arturo Orozco; Juhl, Peter Møller

    2009-01-01

    Acoustic fields are known to exert forces on the surfaces of objects. These forces are noticeable if the sound pressure is sufficiently high. Two phenomena where acoustic forces are relevant are: i) acoustic levitation, where strong standing waves can hold small objects at certain positions......, counterbalancing their weight, and ii) acoustic vortices, spinning sound fields that can impinge angular momentum and cause rotation of objects. In this contribution, both force-creating sound fields are studied by means of numerical simulations. The Boundary Element Method is employed to this end. The simulation...... of acoustical vortices uses an efficient numerical implementation based on the superposition of two orthogonal sound fields with a delay of 90° between them. It is shown that acoustic levitation and the use of acoustic vortices can be combined to manipulate objects in an efficient and controlled manner without...

  13. Density-near-zero using the acoustically induced transparency of a Fano acoustic resonator

    KAUST Repository

    Elayouch, A.

    2017-01-05

    We report experimental results of near-zero mass density involving an acoustic metamaterial supporting Fano resonance. For this, we designed and fabricated an acoustic resonator with two closely coupled modes and measured its transmission properties. Our study reveals that the phenomenon of acoustically induced transparency is accompanied by an effect of near-zero density. Indeed, the dynamic effective parameters obtained from experimental data show the presence of a frequency band where the effective mass density is close to zero, with high transmission levels reaching 0.7. Furthermore, we demonstrate that such effective parameters lead to wave guiding in a 90-degrees-bent channel. This kind of acoustic metamaterial can, therefore, give rise to acoustic functions like controlling the wavefront, which may lead to very promising applications in acoustic cloacking or imaging.

  14. Interior acoustic cloak

    OpenAIRE

    Wael Akl; A. Baz

    2014-01-01

    Acoustic cloaks have traditionally been intended to externally surround critical objects to render these objects acoustically invisible. However, in this paper, the emphasis is placed on investigating the application of the acoustic cloaks to the interior walls of acoustic cavities in an attempt to minimize the noise levels inside these cavities. In this manner, the acoustic cloaks can serve as a viable and efficient alternative to the conventional passive noise attenuation treatments which a...

  15. High throughput imaging cytometer with acoustic focussing† †Electronic supplementary information (ESI) available: High throughput imaging cytometer with acoustic focussing. See DOI: 10.1039/c5ra19497k Click here for additional data file. Click here for additional data file. Click here for additional data file. Click here for additional data file. Click here for additional data file. Click here for additional data file. Click here for additional data file. Click here for additional data file.

    Science.gov (United States)

    Zmijan, Robert; Jonnalagadda, Umesh S.; Carugo, Dario; Kochi, Yu; Lemm, Elizabeth; Packham, Graham; Hill, Martyn

    2015-01-01

    We demonstrate an imaging flow cytometer that uses acoustic levitation to assemble cells and other particles into a sheet structure. This technique enables a high resolution, low noise CMOS camera to capture images of thousands of cells with each frame. While ultrasonic focussing has previously been demonstrated for 1D cytometry systems, extending the technology to a planar, much higher throughput format and integrating imaging is non-trivial, and represents a significant jump forward in capability, leading to diagnostic possibilities not achievable with current systems. A galvo mirror is used to track the images of the moving cells permitting exposure times of 10 ms at frame rates of 50 fps with motion blur of only a few pixels. At 80 fps, we demonstrate a throughput of 208 000 beads per second. We investigate the factors affecting motion blur and throughput, and demonstrate the system with fluorescent beads, leukaemia cells and a chondrocyte cell line. Cells require more time to reach the acoustic focus than beads, resulting in lower throughputs; however a longer device would remove this constraint. PMID:29456838

  16. Springer Handbook of Acoustics

    CERN Document Server

    Rossing, Thomas D

    2007-01-01

    Acoustics, the science of sound, has developed into a broad interdisciplinary field encompassing the academic disciplines of physics, engineering, psychology, speech, audiology, music, architecture, physiology, neuroscience, and others. The Springer Handbook of Acoustics is an unparalleled modern handbook reflecting this richly interdisciplinary nature edited by one of the acknowledged masters in the field, Thomas Rossing. Researchers and students benefit from the comprehensive contents spanning: animal acoustics including infrasound and ultrasound, environmental noise control, music and human speech and singing, physiological and psychological acoustics, architectural acoustics, physical and engineering acoustics, signal processing, medical acoustics, and ocean acoustics. This handbook reviews the most important areas of acoustics, with emphasis on current research. The authors of the various chapters are all experts in their fields. Each chapter is richly illustrated with figures and tables. The latest rese...

  17. Responsive acoustic surfaces

    DEFF Research Database (Denmark)

    Peters, Brady; Tamke, Martin; Nielsen, Stig Anton

    2011-01-01

    Acoustic performance is defined by the parameter of reverberation time; however, this does not capture the acoustic experience in some types of open plan spaces. As many working and learning activities now take place in open plan spaces, it is important to be able to understand and design...... for the acoustic conditions of these spaces. This paper describes an experimental research project that studied the design processes necessary to design for sound. A responsive acoustic surface was designed, fabricated and tested. This acoustic surface was designed to create specific sonic effects. The design...... was simulated using custom integrated acoustic software and also using Odeon acoustic analysis software. The research demonstrates a method for designing space- and sound-defining surfaces, defines the concept of acoustic subspace, and suggests some new parameters for defining acoustic subspaces....

  18. Influence of different frequencies and insertion depths on the diagnostic accuracy of liver elastography by acoustic radiation force impulse imaging (ARFI)

    Energy Technology Data Exchange (ETDEWEB)

    Potthoff, Andrej, E-mail: potthoff.andrej@mh-hannover.de [Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover (Germany); Attia, Dina; Pischke, Sven; Kirschner, Janina; Mederacke, Ingmar; Wedemeyer, Heiner; Manns, Michael P.; Gebel, Michael J.; Rifai, Kinan [Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover (Germany)

    2013-08-15

    Background: Acoustic Radiation Force Impulse Imaging (ARFI) is an innovative elastography for staging of liver fibrosis. We evaluated the diagnostic accuracy of different probes to perform ARFI at different insertion depths. Methods: In a prospective study, 89 chronic HCV infected patients underwent ARFI elastography using both available probes (c-ARFI: C4-1-MHz; l-ARFI: L9-4 MHz) in comparison to Fibroscan{sup ®}. Variability of ARFI elastography at different insertion depths was systematically evaluated in 39 patients (44%). According to Fibroscan{sup ®} elastography, 32 patients (36%) presented with liver cirrhosis, 23 patients (26%) had significant fibrosis and 34 patients (38%) had no significant fibrosis. Results: Mean propagation velocity with c-ARFI was 1.70 ± 0.67 m/s and 1.91 ± 0.87 m/s with l-ARFI. Results of both probes were correlated to each other (p < 0.001; r = 0.70) and to Fibroscan{sup ®} (p < 0.001, r = 0.82 and 0.84, respectively). In patients with significant fibrosis or with cirrhosis, mean values by l-ARFI were significantly higher than by c-ARFI (p < 0.001). For detection of liver cirrhosis, AUROC was 0.97 for c-ARFI (cut-off level 1.72 m/s) and 0.90 for l-ARFI (cut-off 2.04 m/s). Correlation coefficients of c-ARFI with Fibroscan{sup ®} were highest at an insertion depth of 5–6 cm (r = 0.882 and 0.864, respectively, p < 0.001) and at 3–4 cm for l-ARFI (r = 0.850 and 0.838, respectively, p < 0.001). Conclusions: ARFI elastography with the linear and with the convex probes showed comparable validity and accuracy in the estimation of liver stiffness. The linear probe gave higher ARFI values. The most accurate insertion depth was 5–6 cm for c-ARFI and 3–4 cm for l-ARFI indicating that measurements should not be performed close to the liver capsule.

  19. Single-ion 4f element magnetism: an ab-initio look at Ln(COT)2(-).

    Science.gov (United States)

    Gendron, Frédéric; Pritchard, Benjamin; Bolvin, Hélène; Autschbach, Jochen

    2015-12-14

    The electron densities associated with the Ln 4f shell, and spin and orbital magnetizations ('magnetic moment densities'), are investigated for the Ln(COT)2(-) series. The densities are obtained from ab-initio calculations including spin-orbit coupling. For Ln = Ce, Pr the magnetizations are also derived from crystal field models and shown to agree with the ab-initio results. Analysis of magnetizations from ab-initio calculations may be useful in assisting research on single molecule magnets.

  20. Optical and electrical study of CdZnTe surfaces passivated by KOH and NH{sub 4}F solutions

    Energy Technology Data Exchange (ETDEWEB)

    Zázvorka, J., E-mail: zazvorka.jakub@gmail.com [Institute of Physics, Faculty of Mathematics and Physics, Charles University in Prague, Ke Karlovu 5, 121 16 Prague (Czech Republic); Franc, J.; Statelov, M.; Pekárek, J.; Veis, M.; Moravec, P. [Institute of Physics, Faculty of Mathematics and Physics, Charles University in Prague, Ke Karlovu 5, 121 16 Prague (Czech Republic); Mašek, K. [Department of Surface and Plasma Science, Faculty of Mathematics and Physics, Charles University in Prague, V Holešovičkách 2, CZ, 18000 Prague (Czech Republic)

    2016-12-15

    Highlights: • Surface of CdZnTe samples was passivated after chemical etching. • KOH and NH{sub 4}F solutions were used as passivation agents. • Growth of surface oxide after passivation is observed. • Surface oxide thickness was evaluated over time after chemical treatment. • Oxidation of the sample correlates with decreased leakage current. - Abstract: Performance of CdZnTe-based detectors is highly related to surface preparation. Mechanical polishing, chemical etching and passivation are routinely employed for this purpose. However, the relation between these processes and the detector performance in terms of underlying physical phenomena has not been fully explained. The dynamics and properties of CdZnTe surface oxide layers, created by passivation with KOH and NH4F/H2O2 solutions, were studied by optical ellipsometry and X-ray photoelectron spectroscopy (XPS). Thicknesses and growth rates of the surface oxide layers differed for each of the passivation methods. Leakage currents which influence the final spectral resolution of the detector were measured simultaneously with ellipsometry. Results of both optical and electrical investigation showed the same trends in the time evolution and correlated to each other. NH4F/H2O2 passivation showed to be a method which produces the most desirable properties of the surface oxide layer.

  1. High-resolution electron spectroscopy of lanthanide (Ce, Pr, and Nd) complexes of cyclooctatetraene: the role of 4f electrons.

    Science.gov (United States)

    Kumari, Sudesh; Roudjane, Mourad; Hewage, Dilrukshi; Liu, Yang; Yang, Dong-Sheng

    2013-04-28

    Cerium, praseodymium, and neodymium complexes of 1,3,5,7-cyclooctatetraene (COT) complexes were produced in a laser-vaporization metal cluster source and studied by pulsed-field ionization zero electron kinetic energy spectroscopy and quantum chemical calculations. The computations included the second-order Møller-Plesset perturbation theory, the coupled cluster method with single, double, and perturbative triple excitations, and the state-average complete active space self-consistent field method. The spectrum of each complex exhibits multiple band systems and is assigned to ionization of several low-energy electronic states of the neutral complex. This observation is different from previous studies of M(COT) (M = Sc, Y, La, and Gd), for which a single band system was observed. The presence of the multiple low-energy electronic states is caused by the splitting of the partially filled lanthanide 4f orbitals in the ligand field, and the number of the low-energy states increases rapidly with increasing number of the metal 4f electrons. On the other hand, the 4f electrons have a small effect on the geometries and vibrational frequencies of these lanthanide complexes.

  2. Acoustics an introduction

    CERN Document Server

    Kuttruff, Heinrich

    2006-01-01

    This definitive textbook provides students with a comprehensive introduction to acoustics. Beginning with the basic physical ideas, Acoustics balances the fundamentals with engineering aspects, applications and electroacoustics, also covering music, speech and the properties of human hearing. The concepts of acoustics are exposed and applied in:room acousticssound insulation in buildingsnoise controlunderwater sound and ultrasoundScientifically thorough, but with mathematics kept to a minimum, Acoustics is the perfect introduction to acoustics for students at any level of mechanical, electrical or civil engineering courses and an accessible resource for architects, musicians or sound engineers requiring a technical understanding of acoustics and their applications.

  3. Acoustic source for generating an acoustic beam

    Science.gov (United States)

    Vu, Cung Khac; Sinha, Dipen N.; Pantea, Cristian

    2016-05-31

    An acoustic source for generating an acoustic beam includes a housing; a plurality of spaced apart piezo-electric layers disposed within the housing; and a non-linear medium filling between the plurality of layers. Each of the plurality of piezoelectric layers is configured to generate an acoustic wave. The non-linear medium and the plurality of piezo-electric material layers have a matching impedance so as to enhance a transmission of the acoustic wave generated by each of plurality of layers through the remaining plurality of layers.

  4. Acoustic emission linear pulse holography

    International Nuclear Information System (INIS)

    Collins, H.D.; Busse, L.J.; Lemon, D.K.

    1983-01-01

    This paper describes the emission linear pulse holography which produces a chronological linear holographic image of a flaw by utilizing the acoustic energy emitted during crack growth. A thirty two point sampling array is used to construct phase-only linear holograms of simulated acoustic emission sources on large metal plates. The concept behind the AE linear pulse holography is illustrated, and a block diagram of a data acquisition system to implement the concept is given. Array element spacing, synthetic frequency criteria, and lateral depth resolution are specified. A reference timing transducer positioned between the array and the inspection zone and which inititates the time-of-flight measurements is described. The results graphically illustrate the technique using a one-dimensional FFT computer algorithm (ie. linear backward wave) for an AE image reconstruction

  5. Interior acoustic cloak

    Directory of Open Access Journals (Sweden)

    Wael Akl

    2014-12-01

    Full Text Available Acoustic cloaks have traditionally been intended to externally surround critical objects to render these objects acoustically invisible. However, in this paper, the emphasis is placed on investigating the application of the acoustic cloaks to the interior walls of acoustic cavities in an attempt to minimize the noise levels inside these cavities. In this manner, the acoustic cloaks can serve as a viable and efficient alternative to the conventional passive noise attenuation treatments which are invariably heavy and bulky. The transformation acoustics relationships that govern the operation of this class of interior acoustic cloaks are presented. Physical insights are given to relate these relationships to the reasons behind the effectiveness of the proposed interior acoustic cloaks. Finite element models are presented to demonstrate the characteristics of interior acoustic cloaks used in treating the interior walls of circular and square cavities both in the time and frequency domains. The obtained results emphasize the effectiveness of the proposed interior cloaks in eliminating the reflections of the acoustic waves from the walls of the treated cavities and thereby rendering these cavities acoustically quiet. It is important to note here that the proposed interior acoustic cloaks can find applications in acoustic cavities such as aircraft cabins and auditoriums as well as many other critical applications.

  6. Micromachined silicon acoustic delay line with improved structural stability and acoustic directivity for real-time photoacoustic tomography

    Science.gov (United States)

    Cho, Young; Kumar, Akhil; Xu, Song; Zou, Jun

    2017-03-01

    Recent studies have shown that micromachined silicon acoustic delay lines can provide a promising solution to achieve real-time photoacoustic tomography without the need for complex transducer arrays and data acquisition electronics. However, as its length increases to provide longer delay time, the delay line becomes more vulnerable to structural instability due to reduced mechanical stiffness. In addition, the small cross-section area of the delay line results in a large acoustic acceptance angle and therefore poor directivity. To address these two issues, this paper reports the design, fabrication, and testing of a new silicon acoustic delay line enhanced with 3D printed polymer micro linker structures. First, mechanical deformation of the silicon acoustic delay line (with and without linker structures) under gravity was simulated by using finite element method. Second, the acoustic crosstalk and acoustic attenuation caused by the polymer micro linker structures were evaluated with both numerical simulation and ultrasound transmission testing. The result shows that the use of the polymer micro linker structures significantly improves the structural stability of the silicon acoustic delay lines without creating additional acoustic attenuation and crosstalk. In addition, a new tapered design for the input terminal of the delay line was also investigate to improve its acoustic directivity by reducing the acoustic acceptance angle. These two improvements are expected to provide an effective solution to eliminate current limitations on the achievable acoustic delay time and out-of-plane imaging resolution of micromachined silicon acoustic delay line arrays.

  7. Multichannel analysis of surface-waves and integration of downhole acoustic televiewer imaging, ultrasonic Vs and Vp, and vertical seismic profiling in an NEHRP-standard classification, South of Concordia, Kansas, USA

    Science.gov (United States)

    Raef, Abdelmoneam; Gad, Sabreen; Tucker-Kulesza, Stacey

    2015-10-01

    Seismic site characteristics, as pertaining to earthquake hazard reduction, are a function of the subsurface elastic moduli and the geologic structures. This study explores how multiscale (surface, downhole, and laboratory) datasets can be utilized to improve "constrained" average Vs30 (shear-wave velocity to a 30-meter depth). We integrate borehole, surface and laboratory measurements for a seismic site classification based on the standards of the National Earthquake Hazard Reduction Program (NEHRP). The seismic shear-wave velocity (Vs30) was derived from a geophysical inversion workflow that utilized multichannel analysis of surface-waves (MASW) and downhole acoustic televiewer imaging (DATI). P-wave and S-wave velocities, based on laboratory measurements of arrival times of ultrasonic-frequency signals, supported the workflow by enabling us to calculate Poisson's ratio, which was incorporated in building an initial model for the geophysical inversion of MASW. Extraction of core samples from two boreholes provided lithology and thickness calibration of the amplitudes of the acoustic televiewer imaging for each layer. The MASW inversion, for calculating Vs sections, was constrained with both ultrasonic laboratory measurements (from first arrivals of Vs and Vp waveforms at simulated in situ overburden stress conditions) and the downhole acoustic televiewer (DATV) amplitude logs. The Vs30 calculations enabled categorizing the studied site as NEHRP-class "C" - very dense soil and soft rock. Unlike shallow fractured carbonates in the studied area, S-wave and P-wave velocities at ultrasonic frequency for the deeper intact shale core-samples from two boreholes were in better agreement with the corresponding velocities from both a zero-offset vertical seismic profiling (VSP) and inversion of Rayleigh-wave velocity dispersion curves.

  8. Holographic acoustic elements for manipulation of levitated objects

    Science.gov (United States)

    Marzo, Asier; Seah, Sue Ann; Drinkwater, Bruce W.; Sahoo, Deepak Ranjan; Long, Benjamin; Subramanian, Sriram

    2015-10-01

    Sound can levitate objects of different sizes and materials through air, water and tissue. This allows us to manipulate cells, liquids, compounds or living things without touching or contaminating them. However, acoustic levitation has required the targets to be enclosed with acoustic elements or had limited manoeuvrability. Here we optimize the phases used to drive an ultrasonic phased array and show that acoustic levitation can be employed to translate, rotate and manipulate particles using even a single-sided emitter. Furthermore, we introduce the holographic acoustic elements framework that permits the rapid generation of traps and provides a bridge between optical and acoustical trapping. Acoustic structures shaped as tweezers, twisters or bottles emerge as the optimum mechanisms for tractor beams or containerless transportation. Single-beam levitation could manipulate particles inside our body for applications in targeted drug delivery or acoustically controlled micro-machines that do not interfere with magnetic resonance imaging.

  9. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... Facts What is acoustic neuroma? Diagnosing Symptoms Side Effects Keywords Questions to ask Choosing a healthcare provider ... Surgery What is acoustic neuroma Diagnosing Symptoms Side effects Question To Ask Treatment Options Back Overview Observation ...

  10. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... Facts What is acoustic neuroma? Diagnosing Symptoms Side Effects Keywords World Language Videos Questions to ask Choosing ... Surgery What is acoustic neuroma Diagnosing Symptoms Side effects Question To Ask Treatment Options Back Overview Observation ...

  11. Atlantic Herring Acoustic Surveys

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC Advanced Sampling Technologies Research Group conducts annual fisheries acoustic surveys using state-of-the-art acoustic, midwater trawling, and underwater...

  12. Tethys Acoustic Metadata Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Tethys database houses the metadata associated with the acoustic data collection efforts by the Passive Acoustic Group. These metadata include dates, locations...

  13. A4F-SAXS online-coupling for the investigation of nanoparticles and polymers; Die A4F-SAXS Online-Kopplung zur Untersuchung von Nanopartikeln und Polymeren

    Energy Technology Data Exchange (ETDEWEB)

    Knappe, Patrick

    2012-07-13

    In the present thesis the online-coupling of asymmetric flow field-flow fractionation (A4F) with small-angle X-ray scattering (SAXS) as a versatile analytical tool is introduced and applied to current challenges in nanoparticle analysis as well as to model systems of technically relevant polymers. The A4F provides size separation of sample solutions and suspensions. Due to the separation principle only low shear forces are applied which appear in competing methods. Therefore, this method allows processing of very sensitive sample materials. SAXS allows non-destructive probing of nanoscale structures in the range of about one to one hundred nanometers. By coupling with A4F, the complexity of sample systems with broad size distributions, which are therefore frequently hard to characterize, is reduced significantly prior to further analysis. Applying this approach, detailed information about sample properties can be gained accurately with respect to the shape, size and size distribution of particles or conformation of macromolecules in short time. Addition of a dynamic light scattering detector to the setup allows a further conclusion. With the latter, a nanoparticles suspension was characterized rapidly and with good precision with respect to the core properties of the particles as well as the thickness of the stabilizer's shell in a single online run. These parameters are important when dealing not only with functionality but also with the bioavailability or toxicity of nanoparticles. This methodology was also successfully applied to polymer systems for the first time, namely poly(vinyl pyrrolidone)s as well as strong and weak polyelectrolytes. Additionally, due to the applied separation method samples with broad molar mass distributions were processable which otherwise tend to interfere with stationary phase-based chromatography. Furthermore, using SAXS, structural properties can be resolved from smaller polymer size-fractions which are hardly accessible with

  14. A4F-SAXS online-coupling for the investigation of nanoparticles and polymers; Die A4F-SAXS Online-Kopplung zur Untersuchung von Nanopartikeln und Polymeren

    Energy Technology Data Exchange (ETDEWEB)

    Knappe, Patrick

    2012-07-13

    In the present thesis the online-coupling of asymmetric flow field-flow fractionation (A4F) with small-angle X-ray scattering (SAXS) as a versatile analytical tool is introduced and applied to current challenges in nanoparticle analysis as well as to model systems of technically relevant polymers. The A4F provides size separation of sample solutions and suspensions. Due to the separation principle only low shear forces are applied which appear in competing methods. Therefore, this method allows processing of very sensitive sample materials. SAXS allows non-destructive probing of nanoscale structures in the range of about one to one hundred nanometers. By coupling with A4F, the complexity of sample systems with broad size distributions, which are therefore frequently hard to characterize, is reduced significantly prior to further analysis. Applying this approach, detailed information about sample properties can be gained accurately with respect to the shape, size and size distribution of particles or conformation of macromolecules in short time. Addition of a dynamic light scattering detector to the setup allows a further conclusion. With the latter, a nanoparticles suspension was characterized rapidly and with good precision with respect to the core properties of the particles as well as the thickness of the stabilizer's shell in a single online run. These parameters are important when dealing not only with functionality but also with the bioavailability or toxicity of nanoparticles. This methodology was also successfully applied to polymer systems for the first time, namely poly(vinyl pyrrolidone)s as well as strong and weak polyelectrolytes. Additionally, due to the applied separation method samples with broad molar mass distributions were processable which otherwise tend to interfere with stationary phase-based chromatography. Furthermore, using SAXS, structural properties can be resolved from smaller polymer size-fractions which are hardly accessible with other

  15. Tutorial on architectural acoustics

    Science.gov (United States)

    Shaw, Neil; Talaske, Rick; Bistafa, Sylvio

    2002-11-01

    This tutorial is intended to provide an overview of current knowledge and practice in architectural acoustics. Topics covered will include basic concepts and history, acoustics of small rooms (small rooms for speech such as classrooms and meeting rooms, music studios, small critical listening spaces such as home theatres) and the acoustics of large rooms (larger assembly halls, auditoria, and performance halls).

  16. Acoustic Imaging Evaluation of Juvenile Salmonid Behavior in the Immediate Forebay of the Water Temperature Control Tower at Cougar Dam, 2010

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Fenton; Johnson, Gary E.; Royer, Ida M.; Phillips, Nathan RJ; Hughes, James S.; Fischer, Eric S.; Ploskey, Gene R.

    2011-10-01

    This report presents the results of an evaluation of juvenile Chinook salmonid (Oncorhynchus tshawytscha) behavior in the immediate forebay of the Water Temperature Control (WTC) tower at Cougar Dam in 2010. The study was conducted by the Pacific Northwest National Laboratory for the U.S. Army Corps of Engineers. The overall goal of the study was to characterize juvenile salmonid behavior and movement patterns in the immediate forebay of the WTC tower for fisheries resource managers to use to make decisions on bioengineering designs for long-term structures and/or operations to facilitate safe downstream passage for juvenile salmonids. We collected acoustic imaging (Dual-Frequency Identification Sonar; DIDSON) data from February 1, 2010 through January 31, 2011 to evaluate juvenile salmonid behavior year-round in the immediate forebay surface layer of the WTC tower (within 20 m, depth 0-5 m). From October 28, 2010 through January 31, 2011 a BlueView acoustic camera was also deployed in an attempt to determine its usefulness for future studies as well as augment the DIDSON data. For the DIDSON data, we processed a total of 35 separate 24-h periods systematically covering every other week in the 12-month study. Two different 24-hour periods were processed for the BlueView data for the feasibility study. Juvenile salmonids were present in the immediate forebay of the WTC tower throughout 2010. The juvenile salmonid abundance index was low in the spring (<200 fish per sample-day), began increasing in late April and peaked in mid-May. Fish abundance index began decreasing in early June and remained low in the summer months. Fish abundance increased again in the fall, starting in October, and peaked on November 8-9. A second peak occurred on December 22. Afterwards, abundance was low for the rest of the study (through January 2011). Average fish length for juvenile salmonids during early spring 2010 was 214 {+-} 86 mm (standard deviation). From May through early November

  17. Structures and self-activating photoluminescent properties of Sr3−xAxGaO4F (A=Ba, Ca) materials

    International Nuclear Information System (INIS)

    Green, Robert; Vogt, Thomas

    2012-01-01

    The synthesis, structures and photoluminescent properties of mixed oxyfluorides of the type Sr 3−x A x GaO 4 F are compared to Sr 3−x A x AlO 4 F (A=Ca, Ba) materials. In these compounds the F − and O 2− ions are ordered and located on two distinct crystallographic sites. When substituting Sr 2+ by Ba 2+ and Ca 2+ , we find in Sr 3−x A x GaO 4 F materials an ordering of the alkaline earth cations over the two crystallographic sites. The amount of Ba 2+ ions that can be substituted into Sr 3−x A x GaO 4 F is x≤1.2, which is slightly more than can be incorporated into the previously reported Al-analog Sr 3−x A x AlO 4 F (x=1.0). Conversely, the amount of Ca 2+ ions that can be substituted into Sr 3−x Ca x GaO 4 F (x=0.3) is significantly less than in Sr 3−x Ca x AlO 4 F (x=1.0). A post-synthesis reduction step causes these materials to exhibit self-activating broad band photoluminescence where the emitted colors vary with the amount of ions substituted into the host lattice. - Graphical abstract: TOC Statement The structures of the self-activating phosphors Sr 3−x A x MO 4 F (A=Ba, Ca and M=Al, Ga) can be rationalized as alternating layers of bond compression and elongation, which impact the photoluminescence. Highlights: ► Comparison of the structural changes in Sr 3−x A x AlO 4 F and Sr 3−x A x GaO 4 F (A=Ba, Ca) and its influence on the photoluminescence of these self-activating phosphors. ► Analysis of the Global Instability Index of the Sr 3−x A x AlO 4 F and Sr 3−x A x GaO 4 F (A=Ba, Ca). ► Comparison of the photoluminescence between the self-activating phosphors Sr 3−x A x AlO 4 F and Sr 3−x A x GaO 4 F (A=Ba, Ca).

  18. Thermophysical and radiation properties of high-temperature C4F8-CO2 mixtures to replace SF6 in high-voltage circuit breakers

    Science.gov (United States)

    Zhong, Linlin; Cressault, Yann; Teulet, Philippe

    2018-03-01

    C4F8-CO2 mixtures are one of the potential substitutes to SF6 in high-voltage circuit breakers. However, the arc quenching ability of C4F8-CO2 mixtures is still unknown. In order to provide the necessary basic data for the further investigation of arc quenching performance, the compositions, thermodynamic properties, transport coefficients, and net emission coefficients (NEC) of various C4F8-CO2 mixtures are calculated at temperatures of 300-30 000 K in this work. The thermodynamic properties are presented as the product of mass density and specific heat, i.e., ρCp. The transport coefficients include electrical conductivity, viscosity, and thermal conductivity. The atomic and molecular radiation are both taken into account in the calculation of NEC. The comparison of the properties between SF6 and C4F8-CO2 mixtures is also discussed to find their differences. The results of compositions show that C4F8-CO2 mixtures have a distinctive advantage over other alternative gases e.g., CF3I and C3F8, because the dissociative product (i.e., C4F6) of C4F8 at low temperatures has a very high dielectric strength. This is good for an arc quenching medium to endure the arc recovery phase. Compared with SF6, C4F8-CO2 mixtures present lower ρCp at temperatures below 2800 K and larger thermal conductivity above 2800 K. Based on the position of peaks in thermal conductivity, we predict that the cooling of C4F8-CO2 arc will be slowed down at higher temperatures than that of SF6 arc. It is also found that the mixing of CO2 shows slight effects on the electrical conductivity and NEC of C4F8-CO2 mixtures.

  19. Dissociation of 5' proximal helical regions in messenger RNAs by eukaryotic initiation factors 4F, 4A, and 4B

    International Nuclear Information System (INIS)

    Thach, R.E.; Lawson, T.G.; Lee, K.A.; Abramson, R.D.; Merrick, W.C.

    1987-01-01

    Ray, et al. demonstrated that the susceptibility of mRNAs to cleavage by ribonucleases is greatly increased by eIF-4A and eIF-4F in an ATP-dependent reaction, and that this reaction is enhanced by the presence of eIF-4B. They now report direct evidence for the dissociation of helical regions at the 5' ends of mRNAs by these factors. Helices were generated at the 5' ends of reovirus and rabbit globin mRNAs by hybridizing to them 32 P-labeled cDNA pentadecamers. The dissociation of the cDNAs from the mRNAs was monitored by Sephadex gel filtration. Addition of eIF-4F to hybrids caused the dissociation of small amounts of cDNAs, and this dissociation required ATP. Addition of eIF-4B stimulated this activity. Neither eIF-4B nor eIF-4A alone caused significant ATP-dependent dissociation, but they did so in combination. Interestingly, cDNAs that were hybridized to 5' distal regions were dissociated with efficiencies and rates similar to those of 5' proximal cDNAs. The presence of unlabelled cDNAs hybridized 5' proximally did not affect distal cDNA dissociation. These results confirm the earlier suggestion that eIF-4A, eIF-4B and eIF-4F play important roles in the disruption of mRNA secondary structure during initiation

  20. XPS study of the Ln 5p,4f-electronic states of lanthanides in Ln2O3

    International Nuclear Information System (INIS)

    Teterin, Yu.A.; Teterin, A.Yu.; Utkin, I.O.; Ryzhkov, M.V.

    2004-01-01

    The present work analyses the fine structure of the low binding energy (E b , 0-50 eV) X-ray photoelectron spectra XPS of lanthanide (La through Lu excepted for Pm) oxides, and compares it with the non-relativistic X α -discrete variation calculation results for the clusters reflecting the close environment of lanthanides in oxides. The obtained results show that the Ln 4f n -electrons of lanthanides in oxides by their spectral parameters have much in common with the M 3d-electrons in oxides of the 3d-transition metals. According to these data, the Ln 4f shell of lanthanides is rather outer and can participate in the formation of molecular orbitals in compounds. The XPS data at least do not contradict the theoretical suggestion about the significant participation of the Ln 4f-electrons in formation of the molecular orbitals in the studied materials. The spectra in the Ln 5p-O 2s binding energy region of the studied lanthanide oxides were found to exhibit the complicated structure instead of separated peaks due to the electrons of the Ln 5p 3/2,5/2 and O 2s atomic shells. Taking into account the energy differences between the inner (Ln 3d) and outer (Ln 5p) electronic shells for some metallic lanthanides and their oxides, the Ln 5p atomic shells were shown to participate in the formation of the inner valence molecular orbitals (IVMO). That agrees qualitatively with the calculation results

  1. Eigenstates and radiative transition probabilities for Tm3+(4f12) in phosphate and tellurite glasses

    International Nuclear Information System (INIS)

    Spector, N.; Reisfeld, R.; Boehm, L.

    1977-01-01

    Electronic wavefunctions of Tm 3+ in intermediate coupling were obtained and used to calculate the Usup((lambda)) matrix elements between all possible states of the 4f 12 configuration. The Judd-Ofelt intensity parameters Ωsub(lambda) obtained for Tm 3+ in phosphate and tellurite glasses were used in conjunction with the Usup((lambda))'s to calculate the forced electric dipole line strengths. The total electric and magnetic radiative transition probabilities are calculated. The entire theoretical spectrum involving the ground and excited levels (from 129 nm to 16447 nm) is given. (Auth.)

  2. Parametric Room Acoustic Workflows

    DEFF Research Database (Denmark)

    Parigi, Dario; Svidt, Kjeld; Molin, Erik

    2017-01-01

    The paper investigates and assesses different room acoustics software and the opportunities they offer to engage in parametric acoustics workflow and to influence architectural designs. The first step consists in the testing and benchmarking of different tools on the basis of accuracy, speed...... and interoperability with Grasshopper 3d. The focus will be placed to the benchmarking of three different acoustic analysis tools based on raytracing. To compare the accuracy and speed of the acoustic evaluation across different tools, a homogeneous set of acoustic parameters is chosen. The room acoustics parameters...... included in the set are reverberation time (EDT, RT30), clarity (C50), loudness (G), and definition (D50). Scenarios are discussed for determining at different design stages the most suitable acoustic tool. Those scenarios are characterized, by the use of less accurate but fast evaluation tools to be used...

  3. Environmental Dependence of Artifact CD Peaks of Chiral Schiff Base 3d-4f Complexes in Soft Mater PMMA Matrix

    Directory of Open Access Journals (Sweden)

    Yu Okamoto

    2011-10-01

    Full Text Available Four chiral Schiff base binuclear 3d-4f complexes (NdNi, NdCu, GdNi, and GdCu have been prepared and characterized by means of electronic and CD spectra, IR spectra, magnetic measurements, and X-ray crystallography (NdNi. A so-called artifact peak of solid state CD spectra, which was characteristic of oriented molecules without free molecular rotation, appeared at about 470 nm. Magnetic data of the complexes in the solid state (powder and in PMMA cast films or solutions indicated that only GdCu preserved molecular structures in various matrixes of soft maters. For the first time, we have used the changes of intensity of artifact CD peaks to detect properties of environmental (media solid state (KBr pellets, PMMA cast films, concentration dependence of PMMA in acetone solutions, and pure acetone solution for chiral 3d-4f complexes (GdCu. Rigid matrix keeping anisotropic orientation exhibited a decrease in the intensity of the artifact CD peak toward negative values. The present results suggest that solid state artifact CD peaks can be affected by environmental viscosity of a soft mater matrix.

  4. Apolipoprotein A-1 mimetic peptide 4F promotes endothelial repairing and compromises reendothelialization impaired by oxidized HDL through SR-B1

    Directory of Open Access Journals (Sweden)

    Dan He

    2018-05-01

    Full Text Available Disruption of endothelial monolayer integrity is the primary instigating factor for many cardiovascular diseases. High density lipoprotein (HDL oxidized by heme enzyme myeloperoxidase (MPO is dysfunctional in promoting endothelial repair. Apolipoprotein A-1 mimetic 4F with its pleiotropic benefits has been proven effective in many in vivo models. In this study we investigated whether 4F promotes endothelial repair and restores the impaired function of oxidized HDL (Cl/NO2-HDL in promoting re-endothelialization. We demonstrate that 4F and Cl/NO2-HDL act on scavenger receptor type I (SR-B1 using human aorta endothelial cells (HAEC and SR-B1 (-/- mouse aortic endothelial cells. Wound healing, transwell migration, lamellipodia formation and single cell migration assay experiments show that 4F treatment is associated with a recovery of endothelial cell migration and associated with significantly increased endothelial nitric oxide synthase (eNOS activity, Akt phosphorylation and SR-B1 expression. 4F increases NO generation and diminishes oxidative stress. In vivo, 4F can stimulate cell proliferation and re-endothelialization in the carotid artery after treatment with Cl/NO2-HDL in a carotid artery electric injury model but fails to do so in SR-B1(-/- mice. These findings demonstrate that 4F promotes endothelial cell migration and has a potential therapeutic benefit against early endothelial injury in cardiovascular diseases.

  5. Acoustic Imaging Evaluation of Juvenile Salmonid Behavior in the Immediate Forebay of the Water Temperature Control Tower at Cougar Dam, 2010

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Fenton; Johnson, Gary E.; Royer, Ida M.; Phillips, Nathan RJ; Hughes, James S.; Fischer, Eric S.; Ham, Kenneth D.; Ploskey, Gene R.

    2012-04-01

    This report presents the results of an evaluation of juvenile Chinook salmon (Oncorhynchus tshawytscha) behavior at Cougar Dam on the south fork of the McKenzie River in Oregon in 2010. The study was conducted by the Pacific Northwest National Laboratory for the U.S. Army Corps of Engineers (USACE). The overall goal of the study was to characterize juvenile salmonid behavior and movement patterns in the immediate forebay of the Water Temperature Control (WTC) tower of the dam for USACE and fisheries resource managers use in making decisions about bioengineering designs for long-term structures and/or operations to facilitate safe downstream passage for juvenile salmonids. We collected acoustic imaging (Dual-Frequency Identification Sonar; DIDSON) data from March 1, 2010, through January 31, 2011. Juvenile salmonids (hereafter, called 'fish') were present in the immediate forebay of the WTC tower throughout the study. Fish abundance index was low in early spring (<200 fish per sample-day), increased in late April, and peaked on May 19 (6,039 fish). A second peak was observed on June 6 (2904 fish). Fish abundance index decreased in early June and remained low in the summer months (<100 fish per sample-day). During the fall and winter, fish numbers varied with a peak on November 10 (1881 fish) and a minimum on December 7 (12 fish). A second, smaller, peak occurred on December 22 (607 fish). A univariate statistical analysis indicated fish abundance index (log10-transformed) was significantly (P<0.05) positively correlated with forebay elevation, velocity over the WTC tower intake gate weirs, and river flows into the reservoir. A subsequent multiple regression analysis resulted in a model (R2=0.70) predicting fish abundance (log-transformed index values) using two independent variables of mean forebay elevation and the log10 of the forebay elevation range. From the approximate fish length measurements made using the DIDSON imaging software, the average fish

  6. Acoustic Metamaterials in Aeronautics

    Directory of Open Access Journals (Sweden)

    Giorgio Palma

    2018-06-01

    Full Text Available Metamaterials, man-made composites that are scaled smaller than the wavelength, have demonstrated a huge potential for application in acoustics, allowing the production of sub-wavelength acoustic absorbers, acoustic invisibility, perfect acoustic mirrors and acoustic lenses for hyper focusing, and acoustic illusions and enabling new degrees of freedom in the control of the acoustic field. The zero, or even negative, refractive sound index of metamaterials offers possibilities for the control of acoustic patterns and sound at sub-wavelength scales. Despite the tremendous growth in research on acoustic metamaterials during the last decade, the potential of metamaterial-based technologies in aeronautics has still not been fully explored, and its utilization is still in its infancy. Thus, the principal concepts mentioned above could very well provide a means to develop devices that allow the mitigation of the impact of civil aviation noise on the community. This paper gives a review of the most relevant works on acoustic metamaterials, analyzing them for their potential applicability in aeronautics, and, in this process, identifying possible implementation areas and interesting metabehaviors. It also identifies some technical challenges and possible future directions for research with the goal of unveiling the potential of metamaterials technology in aeronautics.

  7. Acoustic Profiling of Bottom Sediments in Large Oil Storage Tanks

    Science.gov (United States)

    Svet, V. D.; Tsysar', S. A.

    2018-01-01

    Characteristic features of acoustic profiling of bottom sediments in large oil storage tanks are considered. Basic acoustic parameters of crude oil and bottom sediments are presented. It is shown that, because of the presence of both transition layers in crude oil and strong reverberation effects in oil tanks, the volume of bottom sediments that is calculated from an acoustic surface image is generally overestimated. To reduce the error, additional post-processing of acoustic profilometry data is proposed in combination with additional measurements of viscosity and tank density distributions in vertical at several points of the tank.

  8. A new acoustic lens material for large area detectors in photoacoustic breast tomography

    NARCIS (Netherlands)

    Xia, W.; Piras, D.; van Hespen, Johannes C.G.; Steenbergen, Wiendelt; Manohar, Srirang

    2013-01-01

    Objectives We introduce a new acoustic lens material for photoacoustic tomography (PAT) to improve lateral resolution while possessing excellent acoustic acoustic impedance matching with tissue to minimize lens induced image artifacts. Background A large surface area detector due to its high

  9. Cloning and expression of a b(0,+)-like amino acid transporter functioning as a heterodimer with 4F2hc instead of rBAT. A new candidate gene for cystinuria.

    Science.gov (United States)

    Rajan, D P; Kekuda, R; Huang, W; Wang, H; Devoe, L D; Leibach, F H; Prasad, P D; Ganapathy, V

    1999-10-08

    We have cloned a transporter protein from rabbit small intestine, which, when coexpressed with the 4F2 heavy chain (4F2hc) in mammalian cells, induces a b(0,+)-like amino acid transport activity. This protein (4F2-lc6 for the sixth member of the 4F2 light chain family) consists of 487 amino acids and has 12 putative transmembrane domains. At the level of amino acid sequence, 4F2-lc6 shows significant homology (44% identity) to the other five known members of the 4F2 light chain family, namely LAT1 (4F2-lc1), y(+)LAT1 (4F2-lc2), y(+)LAT2 (4F2-lc3), xCT (4F2-lc4), and LAT2 (4F2-lc5). The 4F2hc/4F2-lc6 complex-mediated transport process is Na(+)-independent and exhibits high affinity for neutral and cationic amino acids and cystine. These characteristics are similar to those of the b(0,+)-like amino acid transport activity previously shown to be associated with rBAT (protein related to b(0,+) amino acid transport system). However, the newly cloned 4F2-lc6 does not interact with rBAT. This is the first report of the existence of a b(0,+)-like amino acid transport process that is independent of rBAT. 4F2-lc6 is expressed predominantly in the small intestine and kidney. Based on the characteristics of the transport process mediated by the 4F2hc/4F2-lc6 complex and the expression pattern of 4F2-lc6 in mammalian tissues, we suggest that 4F2-lc6 is a new candidate gene for cystinuria.

  10. Springer handbook of acoustics

    CERN Document Server

    2014-01-01

    Acoustics, the science of sound, has developed into a broad interdisciplinary field encompassing the academic disciplines of physics, engineering, psychology, speech, audiology, music, architecture, physiology, neuroscience, and electronics. The Springer Handbook of Acoustics is also in his 2nd edition an unparalleled modern handbook reflecting this richly interdisciplinary nature edited by one of the acknowledged masters in the field, Thomas Rossing. Researchers and students benefit from the comprehensive contents. This new edition of the Handbook features over 11 revised and expanded chapters, new illustrations, and 2 new chapters covering microphone arrays  and acoustic emission.  Updated chapters contain the latest research and applications in, e.g. sound propagation in the atmosphere, nonlinear acoustics in fluids, building and concert hall acoustics, signal processing, psychoacoustics, computer music, animal bioacousics, sound intensity, modal acoustics as well as new chapters on microphone arrays an...

  11. Vibro-acoustics

    CERN Document Server

    Nilsson, Anders

    2015-01-01

    This three-volume book gives a thorough and comprehensive presentation of vibration and acoustic theories. Different from traditional textbooks which typically deal with some aspects of either acoustic or vibration problems, it is unique of this book to combine those two correlated subjects together. Moreover, it provides fundamental analysis and mathematical descriptions for several crucial phenomena of Vibro-Acoustics which are quite useful in noise reduction, including how structures are excited, energy flows from an excitation point to a sound radiating surface, and finally how a structure radiates noise to a surrounding fluid. Many measurement results included in the text make the reading interesting and informative. Problems/questions are listed at the end of each chapter and the solutions are provided. This will help the readers to understand the topics of Vibro-Acoustics more deeply. The book should be of interest to anyone interested in sound and vibration, vehicle acoustics, ship acoustics and inter...

  12. Sistema Óptico de Encriptación de Doble Máscara de Fase bajo Arquitectura 4f

    Directory of Open Access Journals (Sweden)

    Carlos A. Ríos

    2010-12-01

    Full Text Available Nowadays the area of optical encryption of information concentrates the efforts of many researchers in laboratories around the world, mainly because contributions presented in the last two decades have shown the reliability, versatility and applicability of such systems. One of the most successful systems, which is currently protected by several patents, is based on the use of two random phase masks and a 4f architecture. In this contribution we do a review of this optical encryption system. We present the theory and the basic procedure explaining the setups and techniques that allow its experimental implementation, andwe present results obtained by computational simulations of the optical virtual system to show the validity of the method.

  13. Two-gap superconductivity with line nodes in CsCa2Fe4As4F2

    Science.gov (United States)

    Kirschner, Franziska K. K.; Adroja, Devashibhai T.; Wang, Zhi-Cheng; Lang, Franz; Smidman, Michael; Baker, Peter J.; Cao, Guang-Han; Blundell, Stephen J.

    2018-02-01

    We report the results of a muon-spin rotation (μ SR ) experiment to determine the superconducting ground state of the iron-based superconductor CsCa2Fe4As4F2 with Tc≈28.3 K . This compound is related to the fully gapped superconductor CaCsFe4As4 , but here the Ca-containing spacer layer is replaced with one containing Ca2F2 . The temperature evolution of the penetration depth strongly suggests the presence of line nodes and is best modeled by a system consisting of both an s - and a d -wave gap. We also find a potentially magnetic phase which appears below ≈10 K but does not appear to compete with the superconductivity. This compound contains the largest alkali atom in this family of superconductors, and our results yield a value for the in-plane penetration depth of λa b(T =0 ) =244 (3 ) nm .

  14. 17 CFR 41.3 - Application for an exemptive order pursuant to section 4f(a)(4)(B) of the Act.

    Science.gov (United States)

    2010-04-01

    ..., or any broker or dealer exempt from floor broker or floor trader registration pursuant to section 4f... Commission may, in its sole discretion, grant the application, deny the application, decline to entertain the...

  15. Handbook of Engineering Acoustics

    CERN Document Server

    Möser, Michael

    2013-01-01

    This book examines the physical background of engineering acoustics, focusing on empirically obtained engineering experience as well as on measurement techniques and engineering methods for prognostics. Its goal is not only to describe the state of art of engineering acoustics but also to give practical help to engineers in order to solve acoustic problems. It deals with the origin, the transmission and the methods of the abating different kinds of air-borne and structure-borne sounds caused by various mechanisms – from traffic to machinery and flow-induced sound. In addition the modern aspects of room and building acoustics, as well as psychoacoustics and active noise control, are covered.

  16. Acoustic Technology Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — This laboratory contains an electro-magnetic worldwide data collection and field measurement capability in the area of acoustic technology. Outfitted by NASA Langley...

  17. Shallow Water Acoustic Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Supports experimental research where high-frequency acoustic scattering and surface vibration measurements of fluid-loaded and non-fluid-loaded structures...

  18. Laboratory for Structural Acoustics

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Supports experimental research where acoustic radiation, scattering, and surface vibration measurements of fluid-loaded and non-fluid-loaded structures are...

  19. Micro-fabricated membrane gas valves with a non-stiction coating deposited by C4F8/Ar plasma

    International Nuclear Information System (INIS)

    Han, Jeahyeong; Flachsbart, Bruce; Shannon, Mark A; Masel, Rich I

    2008-01-01

    Micro-fabricated gas valves with C 4 F 8 /Ar treatment at the sealing interface are designed, fabricated and characterized to passively control gases in a micro gas analysis system. The check valves form a seal between a polished Si/SiO 2 substrate and a smooth polyimide (PI) membrane. The smooth PI membrane touches the SiO 2 surface, giving rise to relatively strong van der Waals adhesion, and under humid conditions hydrogen-bonded stiction can occur at the interface between PI and SiO 2 . To prevent stiction from dominating adhesion, the valve-seat surface was treated with a hydrophobic CF n thin film, which was formed by exposing the surface to C 4 F 8 /Ar inductively coupled plasma (ICP) at low power. The valves without a non-stiction coating did not open with inlet pressures up to 210 kPa. With a non-stiction coating, the valves showed an average initial opening pressure of 59.25 kPa. In order to further reduce the opening pressure, 40% of the valve-seat area is reduced. After modification, the average opening pressure is reduced to 32.5 kPa. After the initial opening, the average in-use opening pressure was 16.9 kPa before area modification, and 13.1 kPa after the modification. The valve has been tested up to 10 000 open/close cycles under dry N 2 gas flow, and an additional 3000 open/close cycles under humid N 2 gas flow. The average forward flow conductance of the valves before modification was 1.1 sccm kPa −1 , and the conductance after modification was 1.41 sccm kPa −1 . The measured leakage is between 0.0003 and 0.004 sccm up to 35 kPa reverse pressure

  20. Acoustic shadows help gleaning bats find prey, but may be defeated by prey acoustic camouflage on rough surfaces.

    Science.gov (United States)

    Clare, Elizabeth L; Holderied, Marc W

    2015-09-01

    Perceptual abilities of animals, like echolocating bats, are difficult to study because they challenge our understanding of non-visual senses. We used novel acoustic tomography to convert echoes into visual representations and compare these cues to traditional echo measurements. We provide a new hypothesis for the echo-acoustic basis of prey detection on surfaces. We propose that bats perceive a change in depth profile and an 'acoustic shadow' cast by prey. The shadow is more salient than prey echoes and particularly strong on smooth surfaces. This may explain why bats look for prey on flat surfaces like leaves using scanning behaviour. We propose that rather than forming search images for prey, whose characteristics are unpredictable, predators may look for disruptions to the resting surface (acoustic shadows). The fact that the acoustic shadow is much fainter on rougher resting surfaces provides the first empirical evidence for 'acoustic camouflage' as an anti-predator defence mechanism.

  1. Hyperfine fields at some 4d, 5d and 4f impurities in ferromagnetic GdZn and GdCd

    International Nuclear Information System (INIS)

    Kasamatsu, Y.; Kojima, K.; Hihara, T.

    1995-01-01

    Hyperfine (hf) fields at 4d (Y, Nb, Rh, Pd), 5d (Lu, Ta, Ir) and 4f (La, Nd, Sm, Eu) impurities in ferromagnetic GdZn and GdCd have been measured by NMR at 4.2 K. The local moment contributions to the hf field suggest that the impurity moments at the beginning and end of the d series are parallel and antiparallel to Gd moments, respectively. The hf results for 4f impurities are also discussed. ((orig.))

  2. Acoustic Levitation With Less Equipment

    Science.gov (United States)

    Barmatz, M. B.; Jacobi, N.

    1983-01-01

    Certain chamber shapes require fewer than three acoustic drivers. Levitation at center of spherical chamber attained using only one acoustic driver. Exitation of lowest spherical mode produces asymmetric acoustic potential well.

  3. What Is an Acoustic Neuroma

    Science.gov (United States)

    ... CALENDAR DONATE NEWS Home Learn Back Learn about acoustic neuroma AN Facts What is acoustic neuroma? Diagnosing ... Italian Japanese Korean Portuguese Romanian Spanish What is Acoustic Neuroma? Each heading slides to reveal information. Important ...

  4. Silver-coated LiVPO4F composite with improved electrochemical performance as cathode material for lithium-ion batteries

    Science.gov (United States)

    Yang, Bo; Yang, Lin

    2015-12-01

    Nano-structured LiVPO4F/Ag composite cathode material has been successfully synthesized via a sol-gel route. The structural and physical properties, as well as the electrochemical performance of the material are compared with those of the pristine LiVPO4F. X-ray diffraction (XRD) and scanning electron microscopy (SEM) reveal that Ag particles are uniformly dispersed on the surface of LiVPO4F without destroying the crystal structure of the bulk material. An analysis of the electrochemical measurements show that the Ag-modified LiVPO4F material exhibits high discharge capacity, good cycle performance (108.5 mAh g-1 after 50th cycles at 0.1 C, 93% of initial discharge capacity) and excellent rate behavior (81.8 mAh g-1 for initial discharge capacity at 5 C). The electrochemical impedance spectroscopy (EIS) results reveal that the adding of Ag decreases the charge-transfer resistance (Rct) of LiVPO4F cathode. This study demonstrates that Ag-coating is a promising way to improve the electrochemical performance of the pristine LiVPO4F for lithium-ion batteries cathode material.

  5. A computational study of magnetic exchange interactions of 3d and 4f electrons in Ti-Ce co-doped AlN

    Energy Technology Data Exchange (ETDEWEB)

    Majid, Abdul, E-mail: abdulmajid40@yahoo.com [Department of Physics, University of Gujrat, Gujrat (Pakistan); Department of Adaptive Machine Systems, Osaka University, Osaka (Japan); Azmat, Mian [Department of Physics, University of Gujrat, Gujrat (Pakistan); Rana, Usman Ali; Khan, Salah Ud-Din [Sustainable Energy Technologies Center, College of Engineering, King Saud University, PO-Box 800, Riyadh 11421 (Saudi Arabia); Alzahrani, Eman [Department of Chemistry, Faculty of Science, Taif University, 888 Taif (Saudi Arabia)

    2016-08-15

    To investigate the nature of 3d-4f exchange interactions in III-Nitride semiconductors, Ti-Ce co-doped AlN were studied using first principles calculations. The calculations were performed using supercell approach with varying dopant concentration and different inter-dopant separation. The configuration with dopant located as nearest neighbor distance and diluted concentration of 3.125% was found most stable. The results exhibited prominent evidence of 3d-4f-5d strong hybridization suggesting 3d-4f direct exchange interactions which may play valuable role to exploit the system as high Curie temperature ferromagnetic semiconductors for use in spintronics. Moreover, metal to metal charge transfer was also observed in the materials which may be exploited for their use in electrochemical applications. The 4f-5d and 3d-5d hybridizations were observed that predicts excellent luminescence phenomena in the materials. The presence of impurity related deep intermediate bands suggest applications of the materials in opto-electronic and spintronics devices. - Highlights: • Double exchange interaction in Ti:AlN. • Impurity induced narrowing of band gap. • Superexchange interaction in Ce:AlN. • 3d-4f exchange interaction between Ti-3d and Ce-4f states. • High Curie temperature n-type ferromagnetic semiconductors.

  6. A computational study of magnetic exchange interactions of 3d and 4f electrons in Ti-Ce co-doped AlN

    International Nuclear Information System (INIS)

    Majid, Abdul; Azmat, Mian; Rana, Usman Ali; Khan, Salah Ud-Din; Alzahrani, Eman

    2016-01-01

    To investigate the nature of 3d-4f exchange interactions in III-Nitride semiconductors, Ti-Ce co-doped AlN were studied using first principles calculations. The calculations were performed using supercell approach with varying dopant concentration and different inter-dopant separation. The configuration with dopant located as nearest neighbor distance and diluted concentration of 3.125% was found most stable. The results exhibited prominent evidence of 3d-4f-5d strong hybridization suggesting 3d-4f direct exchange interactions which may play valuable role to exploit the system as high Curie temperature ferromagnetic semiconductors for use in spintronics. Moreover, metal to metal charge transfer was also observed in the materials which may be exploited for their use in electrochemical applications. The 4f-5d and 3d-5d hybridizations were observed that predicts excellent luminescence phenomena in the materials. The presence of impurity related deep intermediate bands suggest applications of the materials in opto-electronic and spintronics devices. - Highlights: • Double exchange interaction in Ti:AlN. • Impurity induced narrowing of band gap. • Superexchange interaction in Ce:AlN. • 3d-4f exchange interaction between Ti-3d and Ce-4f states. • High Curie temperature n-type ferromagnetic semiconductors.

  7. Micromachined silicon acoustic delay line with 3D-printed micro linkers and tapered input for improved structural stability and acoustic directivity

    International Nuclear Information System (INIS)

    Cho, Y; Kumar, A; Xu, S; Zou, J

    2016-01-01

    Recent studies have shown that micromachined silicon acoustic delay lines can provide a promising solution to achieve real-time photoacoustic tomography without the need for complex transducer arrays and data acquisition electronics. To achieve deeper imaging depth and wider field of view, a longer delay time and therefore delay length are required. However, as the length of the delay line increases, it becomes more vulnerable to structural instability due to reduced mechanical stiffness. In this paper, we report the design, fabrication, and testing of a new silicon acoustic delay line enhanced with 3D printed polymer micro linker structures. First, mechanical deformation of the silicon acoustic delay line (with and without linker structures) under gravity was simulated by using finite element method. Second, the acoustic crosstalk and acoustic attenuation caused by the polymer micro linker structures were evaluated with both numerical simulation and ultrasound transmission testing. The result shows that the use of the polymer micro linker structures significantly improves the structural stability of the silicon acoustic delay lines without creating additional acoustic attenuation and crosstalk. In addition, the improvement of the acoustic acceptance angle of the silicon acoustic delay lines was also investigated to better suppress the reception of unwanted ultrasound signals outside of the imaging plane. These two improvements are expected to provide an effective solution to eliminate current limitations on the achievable acoustic delay time and out-of-plane imaging resolution of micromachined silicon acoustic delay line arrays. (paper)

  8. Analysis of the acoustic sound in MRI

    Energy Technology Data Exchange (ETDEWEB)

    Wada, Tetsuro; Hara, Akira; Kusakari, Jun; Yoshioka, Hiroshi; Niitsu, Mamoru; Itai, Yuji [Tsukuba Univ., Ibaraki (Japan). Inst. of Clinical Medicine; Ase, Yuji

    1999-04-01

    The noise level and power spectra of the acoustic sound exposed during the examination of Magnetic Resonance Imaging (MRI) using a MRI scanner (Philips Gyroscan 1.5 T) were measured at the position of the human auricle. The overall noise levels on T1-weighted images and T2-weighted images with Spin Echo were 105 dB and 98 dB, respectively. The overall noise level on T2-weighted images with Turbo Spin Echo was 110 dB. Fourier analysis revealed energy peaks ranging from 225 to 325 Hz and a steep high frequency cutoff for each pulse sequence. The MRI noise was not likely to cause permanent threshold shift. However, because of the inter-subject variation in susceptibility to acoustic trauma and to exclude the anxiety in patients, ear protectors were recommended for all patients during MRI testing. (author)

  9. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... 30041 770-205-8211 info@ANAUSA.org The world’s #1 acoustic neuroma resource Click to learn more... ... is acoustic neuroma? Diagnosing Symptoms Side Effects Keywords World Language Videos Questions to ask Choosing a healthcare ...

  10. Acoustics Critical Readiness Review

    Science.gov (United States)

    Ballard, Kenny

    2010-01-01

    This presentation reviews the status of the acoustic equipment from the medical operations perspective. Included is information about the acoustic dosimeters, sound level meter, and headphones that are planned for use while on orbit. Finally there is information about on-orbit hearing assessments.

  11. Acoustic Signals and Systems

    DEFF Research Database (Denmark)

    2008-01-01

    The Handbook of Signal Processing in Acoustics will compile the techniques and applications of signal processing as they are used in the many varied areas of Acoustics. The Handbook will emphasize the interdisciplinary nature of signal processing in acoustics. Each Section of the Handbook...... will present topics on signal processing which are important in a specific area of acoustics. These will be of interest to specialists in these areas because they will be presented from their technical perspective, rather than a generic engineering approach to signal processing. Non-specialists, or specialists...... from different areas, will find the self-contained chapters accessible and will be interested in the similarities and differences between the approaches and techniques used in different areas of acoustics....

  12. Computational Ocean Acoustics

    CERN Document Server

    Jensen, Finn B; Porter, Michael B; Schmidt, Henrik

    2011-01-01

    Since the mid-1970s, the computer has played an increasingly pivotal role in the field of ocean acoustics. Faster and less expensive than actual ocean experiments, and capable of accommodating the full complexity of the acoustic problem, numerical models are now standard research tools in ocean laboratories. The progress made in computational ocean acoustics over the last thirty years is summed up in this authoritative and innovatively illustrated new text. Written by some of the field's pioneers, all Fellows of the Acoustical Society of America, Computational Ocean Acoustics presents the latest numerical techniques for solving the wave equation in heterogeneous fluid–solid media. The authors discuss various computational schemes in detail, emphasizing the importance of theoretical foundations that lead directly to numerical implementations for real ocean environments. To further clarify the presentation, the fundamental propagation features of the techniques are illustrated in color. Computational Ocean A...

  13. Calibration of acoustic emission transducers

    International Nuclear Information System (INIS)

    Leschek, W.C.

    1976-01-01

    A method is described for calibrating an acoustic emission transducer to be used in a pre-set frequency range. The absolute reception sensitivity of a reference transducer is determined at frequencies selected within the frequency range. The reference transducer and the acoustic emission transducer are put into acoustic communication with the surface of a limited acoustic medium representing an equivalent acoustic load appreciably identical to that of the medium in which the use of the acoustic emission transducer is intended. A blank random acoustic noise is emitted in the acoustic medium in order to establish a diffuse and reverberating sound field, after which the output responses of the reference transducer and of the acoustic emission transducer are obtained with respect to the diffuse and reverberating field, for selected frequencies. The output response of the acoustic emission transducer is compared with that of the reference transducer for the selected frequencies, so as to determine the reception sensitivity of the acoustic emission transducer [fr

  14. POU4F3 mutation screening in Japanese hearing loss patients: Massively parallel DNA sequencing-based analysis identified novel variants associated with autosomal dominant hearing loss.

    Directory of Open Access Journals (Sweden)

    Tomohiro Kitano

    Full Text Available A variant in a transcription factor gene, POU4F3, is responsible for autosomal dominant nonsyndromic hereditary hearing loss, DFNA15. To date, 14 variants, including a whole deletion of POU4F3, have been reported to cause HL in various ethnic groups. In the present study, genetic screening for POU4F3 variants was carried out for a large series of Japanese hearing loss (HL patients to clarify the prevalence and clinical characteristics of DFNA15 in the Japanese population. Massively parallel DNA sequencing of 68 target candidate genes was utilized in 2,549 unrelated Japanese HL patients (probands to identify genomic variations responsible for HL. The detailed clinical features in patients with POU4F3 variants were collected from medical charts and analyzed. Novel 12 POU4F3 likely pathogenic variants (six missense variants, three frameshift variants, and three nonsense variants were successfully identified in 15 probands (2.5% among 602 families exhibiting autosomal dominant HL, whereas no variants were detected in the other 1,947 probands with autosomal recessive or inheritance pattern unknown HL. To obtain the audiovestibular configuration of the patients harboring POU4F3 variants, we collected audiograms and vestibular symptoms of the probands and their affected family members. Audiovestibular phenotypes in a total of 24 individuals from the 15 families possessing variants were characterized by progressive HL, with a large variation in the onset age and severity with or without vestibular symptoms observed. Pure-tone audiograms indicated the most prevalent configuration as mid-frequency HL type followed by high-frequency HL type, with asymmetry observed in approximately 20% of affected individuals. Analysis of the relationship between age and pure-tone average suggested that individuals with truncating variants showed earlier onset and slower progression of HL than did those with non-truncating variants. The present study showed that variants

  15. A Klein-Gordon acoustic theory

    Energy Technology Data Exchange (ETDEWEB)

    Anno, P.D.

    1992-12-01

    Geophysicists do not associate traveltime variation with density variation in acoustic or elastic wavefield interpretation. Rather, given a constant index of refraction, density variation within the medium of propagation is associated only with amplitudes. This point of view prevails because density does not occur as a variable in classical results such as Snell's Law or the eikonal equation. Nevertheless, in this paper I predict, analytically, a continuum of density effects on acoustic wavefields-including a dispersive traveltime delay when density variation is rapid. I also examine the ability of a common imaging algorithm to cope with this time delay.

  16. A Klein-Gordon acoustic theory

    Energy Technology Data Exchange (ETDEWEB)

    Anno, Phil D. [Colorado School of Mines, Golden, CO (United States)

    1992-12-01

    Geophysicists do not associate traveltime variation with density variation in acoustic or elastic wavefield interpretation. Rather, given a constant index of refraction, density variation within the medium of propagation is associated only with amplitudes. This point of view prevails because density does not occur as a variable in classical results such as Snell`s Law or the eikonal equation. Nevertheless, in this paper I predict, analytically, a continuum of density effects on acoustic wavefields-including a dispersive traveltime delay when density variation is rapid. I also examine the ability of a common imaging algorithm to cope with this time delay.

  17. Parametric Room Acoustic workflows with real-time acoustic simulation

    DEFF Research Database (Denmark)

    Parigi, Dario

    2017-01-01

    The paper investigates and assesses the opportunities that real-time acoustic simulation offer to engage in parametric acoustics workflow and to influence architectural designs from early design stages......The paper investigates and assesses the opportunities that real-time acoustic simulation offer to engage in parametric acoustics workflow and to influence architectural designs from early design stages...

  18. 3s--3p, 3p--3d, and 3d--4f transitions of sodiumlike ions

    International Nuclear Information System (INIS)

    Reader, J.; Kaufman, V.; Sugar, J.; Olof Ekberg, J.; Feldman, U.; Brown, C.M.; Seely, J.F.; Rowan, W.L.

    1987-01-01

    New measurements have been made for wavelengths of the 3s--3p, 3p--3d, and 3d--4f transitions of the sodiumlike ions Cu/sup 18+/, Zn/sup 19+/, Ga/sup 20+/, Ge/sup 21+/, As/sup 22+/, Se/sup 23+/, Br/sup 24+/, Kr/sup 25+/, Y/sup 28+/, Zr/sup 29+/, Nb/sup 30+/, Mo/sup 31+/, Ru/sup 33+/, Rh/sup 34+/, Pd/sup 35+/, Ag/sup 36+/, and Sn/sup 39+/. The measurements were made by photographing laser-produced plasmas and tokamak plasmas with grazing-incidence spectrographs. The energies of the transitions were also calculated with Dirac--Fock computer codes. By fitting the differences between the observed and calculated wave numbers to simple formulas, least-squares-fitted wavelengths for all sodiumlike ions from Ar 7+ to Xe/sup 43+/ were determined. The estimated uncertainty of the fitted wavelengths is +- 0.007 A, which makes them useful as reference values. The wavelengths range from 9 to 713 A

  19. The crystal structure of bøgvadite (Na2SrBa2Al4F20)

    DEFF Research Database (Denmark)

    Balic Zunic, Tonci

    2014-01-01

    The crystal structure of bøgvadite, Na2SrBa2Al4F20, has been solved and refined to a R1 factor of 4.4% from single-crystal data (MoKα X-ray diffraction, CCD area detector) on a sample from the cryolite deposit at Ivittuut, SW Greenland. Bøgvadite is monoclinic, P21/n space group, with unit cell...... parameters a= 7.134(1), b= 19.996(3) and c= 5.3440(8) Å, β = 90.02(1)o. A close proximity of the crystal structure to an orthorhombic symmetry and the presence of the two twin components in a nearly 1:1 ratio suggest that the investigated bøgvadite crystal has originally formed as a high......-temperature orthorhombic polymorph which on cooling transformed to the stable low temperature monoclinic structure. The bøgvadite crystal structure has groupings of cation-fluoride coordination polyhedra similar to those found in the crystal structures of the genetically closely associated minerals jarlite...

  20. 3d-4f {Co(II)3Ln(OR)4} Cubanes as Bio-Inspired Water Oxidation Catalysts.

    Science.gov (United States)

    Evangelisti, Fabio; Moré, René; Hodel, Florian; Luber, Sandra; Patzke, Greta Ricarda

    2015-09-02

    Although the {CaMn4O5} oxygen evolving complex (OEC) of photosystem II is a major paradigm for water oxidation catalyst (WOC) development, the comprehensive translation of its key features into active molecular WOCs remains challenging. The [Co(II)3Ln(hmp)4(OAc)5H2O] ({Co(II)3Ln(OR)4}; Ln = Ho-Yb, hmp = 2-(hydroxymethyl)pyridine) cubane WOC series is introduced as a new springboard to address crucial design parameters, ranging from nuclearity and redox-inactive promoters to operational stability and ligand exchange properties. The {Co(II)3Ln(OR)4} cubanes promote bioinspired WOC design by newly combining Ln(3+) centers as redox-inactive Ca(2+) analogues with flexible aqua-/acetate ligands into active and stable WOCs (max. TON/TOF values of 211/9 s(-1)). Furthermore, they open up the important family of 3d-4f complexes for photocatalytic applications. The stability of the {Co(II)3Ln(OR)4} WOCs under photocatalytic conditions is demonstrated with a comprehensive analytical strategy including trace metal analyses and solution-based X-ray absorption spectroscopy (XAS) investigations. The productive influence of the Ln(3+) centers is linked to favorable ligand mobility, and the experimental trends are substantiated with Born-Oppenheimer molecular dynamics studies.

  1. Transmission acoustic microscopy investigation

    Science.gov (United States)

    Maev, Roman; Kolosov, Oleg; Levin, Vadim; Lobkis, Oleg

    The nature of acoustic contrast, i.e. the connection of the amplitude and phase of the output signal of the acoustic microscope with the local values of the acoustic parameters of the sample (density, elasticity, viscosity) is a central problem of acoustic microscopy. A considerable number of studies have been devoted to the formation of the output signal of the reflection scanning acoustic microscope. For the transmission acoustic microscope (TAM) this problem has remained almost unstudied. Experimental investigation of the confocal system of the TAM was carried out on an independently manufactured laboratory mockup of the TAM with the working frequency of the 420 MHz. Acoustic lenses with the radius of curvature of about 500 microns and aperture angle of 45 deg were polished out in the end faces of two cylindrical sound conductors made from Al2O3 single crystals with an axis parallel to the axis C of the crystal (the length of the sound conductor is 20 mm; diameter, 6 mm). At the end faces of the sound conductor, opposite to the lenses, CdS transducers with a diameter of 2 mm were disposed. The electric channel of the TAM provided a possibility for registering the amplitude of the microscope output signal in the case of the dynamic range of the 50 dB.

  2. The accidental (acoustical) tourist

    Science.gov (United States)

    Van Kirk, Wayne

    2002-11-01

    The acoustical phenomenon observed at an ancient temple in the Great Ball Court at Chichen Itza was described as ''little short of amazing--an ancient whispering gallery'' by Silvanus G. Morley, leader of the Carnegie Institute's archaeological team that excavated and restored these structures in the 1920s. Since then, many others have experienced the extraordinary acoustics at Chichen Itza and other Maya sites. Despite these reports, archaeologists and acousticians have until recently shown little interest in understanding these phenomena. After experiencing Chichen Itza's remarkable acoustics as a tourist in 1994, the author commenced collecting and disseminating information about acoustical phenomena there and at other Mayan sites, hoping to stimulate interest among archaeologists and acousticians. Were these designs accidental or intentional? If intentional, how was the knowledge obtained? How were acoustical features used? This paper highlights the author's collection of anecdotal reports of mysterious Mayan acoustics (http://http://www.ianlawton.com/pa1.htm), recommended reading for scientists and engineers who wish to pursue this fascinating study. Also recounted are some of the reactions of archaeologists-ranging from curious, helpful, and insightful to humorous and appalling--to outsiders' efforts to bring serious scientific attention to the new field of acoustical archaeology.

  3. Investigation into the Effect of Acoustic Radiation Force and Acoustic Streaming on Particle Patterning in Acoustic Standing Wave Fields

    Directory of Open Access Journals (Sweden)

    Shilei Liu

    2017-07-01

    Full Text Available Acoustic standing waves have been widely used in trapping, patterning, and manipulating particles, whereas one barrier remains: the lack of understanding of force conditions on particles which mainly include acoustic radiation force (ARF and acoustic streaming (AS. In this paper, force conditions on micrometer size polystyrene microspheres in acoustic standing wave fields were investigated. The COMSOL® Mutiphysics particle tracing module was used to numerically simulate force conditions on various particles as a function of time. The velocity of particle movement was experimentally measured using particle imaging velocimetry (PIV. Through experimental and numerical simulation, the functions of ARF and AS in trapping and patterning were analyzed. It is shown that ARF is dominant in trapping and patterning large particles while the impact of AS increases rapidly with decreasing particle size. The combination of using both ARF and AS for medium size particles can obtain different patterns with only using ARF. Findings of the present study will aid the design of acoustic-driven microfluidic devices to increase the diversity of particle patterning.

  4. Investigation into the Effect of Acoustic Radiation Force and Acoustic Streaming on Particle Patterning in Acoustic Standing Wave Fields

    Science.gov (United States)

    Yang, Yanye; Ni, Zhengyang; Guo, Xiasheng; Luo, Linjiao; Tu, Juan; Zhang, Dong

    2017-01-01

    Acoustic standing waves have been widely used in trapping, patterning, and manipulating particles, whereas one barrier remains: the lack of understanding of force conditions on particles which mainly include acoustic radiation force (ARF) and acoustic streaming (AS). In this paper, force conditions on micrometer size polystyrene microspheres in acoustic standing wave fields were investigated. The COMSOL® Mutiphysics particle tracing module was used to numerically simulate force conditions on various particles as a function of time. The velocity of particle movement was experimentally measured using particle imaging velocimetry (PIV). Through experimental and numerical simulation, the functions of ARF and AS in trapping and patterning were analyzed. It is shown that ARF is dominant in trapping and patterning large particles while the impact of AS increases rapidly with decreasing particle size. The combination of using both ARF and AS for medium size particles can obtain different patterns with only using ARF. Findings of the present study will aid the design of acoustic-driven microfluidic devices to increase the diversity of particle patterning. PMID:28753955

  5. Translational illusion of acoustic sources by transformation acoustics.

    Science.gov (United States)

    Sun, Fei; Li, Shichao; He, Sailing

    2017-09-01

    An acoustic illusion of creating a translated acoustic source is designed by utilizing transformation acoustics. An acoustic source shifter (ASS) composed of layered acoustic metamaterials is designed to achieve such an illusion. A practical example where the ASS is made with naturally available materials is also given. Numerical simulations verify the performance of the proposed device. The designed ASS may have some applications in, e.g., anti-sonar detection.

  6. Targeted partial surface modification with nano-SiO2@Li2CoPO4F as high-voltage cathode material for LIBs

    Science.gov (United States)

    Chang, Caiyun; Huang, Zhipeng; Tian, Runsai; Jiang, Xinyu; Li, Chunsheng; Feng, Jijun

    2017-10-01

    Tuning whole/partial surface modification on cathode material with oxide material is a sought-after method to enhance the electrochemical performance in power storage field. Herein, nano-SiO2 targeted partial surface modified high voltage cathode material Li2CoPO4F has been successfully fabricated via a facile self-assembly process in silica dispersion at ambient temperature. With the aid of polar -OH groups attracted on the surface of SiO2 micelles, the nano-SiO2 preferentially nestle up along the borders and boundaries of Li2CoPO4F particles, where protection should be deployed with emphasis against the undesirable interactions between materials and electrolytes. Compared with pristine Li2CoPO4F, the SiO2 selectively modified Li2CoPO4F cathode materials, especially LCPF-3S, exhibit desirable electrochemical performances with higher discharge capacity, more outstanding cycle stability and favorable rate capability without any additional carbon involved. The greatly enhanced electrochemical properties can be attributed to the improved lithium-ion diffusion kinetics and structure tolerance during repeated lithiation/delithiation process. Such findings reveal a great potential of nano-SiO2 modified Li2CoPO4F as high energy cathode material for lithium ion batteries.

  7. Acoustic building infiltration measurement system

    Science.gov (United States)

    Muehleisen, Ralph T.; Raman, Ganesh

    2018-04-10

    Systems and methods of detecting and identifying a leak from a container or building. Acoustic pressure and velocity are measured. Acoustic properties are acquired from the measured values. The acoustic properties are converted to infiltration/leakage information. Nearfield Acoustic Holography (NAH) may be one method to detect the leakages from a container by locating the noise sources.

  8. What does See the Impulse Acoustic Microscopy inside Nanocomposites?

    Science.gov (United States)

    Levin, V. M.; Petronyuk, Y. S.; Morokov, E. S.; Celzard, A.; Bellucci, S.; Kuzhir, P. P.

    The paper presents results of studying bulk microstructure in carbon nanocomposites by impulse acoustic microscopy technique. Nanocomposite materials are in the focus of interest because of their outstanding properties in minimal nanofiller content. Large surface area and high superficial activity cause strong interaction between nanoparticles that can result in formation of fractal conglomerates. This paper involves results of the first direct observation of nanoparticle conglomerates inside the bulk of epoxy-carbon nanocomposites. Diverse types of carbon nanofiller have been under investigation. The impulse acoustic microscope SIAM-1 (Acoustic Microscopy Lab, IBCP RAS) has been employed for 3D imaging bulk microstructure and measuring elastic properties of the nanocomposite specimens. The range of 50-200 MHz allows observing microstructure inside the entire specimen bulk. Acoustic images are obtained in the ultramicroscopic regime; they are formed by the Rayleigh type scattered radiation. It has been found the high-resolution acoustic vision (impulse acoustic microscopy) is an efficient technique to observe mesostructure formed by fractal cluster inside nanocomposites. The clusterization takes its utmost form in nanocomposites with graphite nanoplatelets as nanofiller. The nanoparticles agglomerate into micron-sized conglomerates distributed randomly over the material. Mesostructure in nanocomposites filled with carbon nanotubes is alternation of regions with diverse density of nanotube packing. Regions with alternative density of CNT packing are clearly seen in acoustical images as neighboring pixels of various brightness.

  9. Acoustical heat pumping engine

    Science.gov (United States)

    Wheatley, J.C.; Swift, G.W.; Migliori, A.

    1983-08-16

    The disclosure is directed to an acoustical heat pumping engine without moving seals. A tubular housing holds a compressible fluid capable of supporting an acoustical standing wave. An acoustical driver is disposed at one end of the housing and the other end is capped. A second thermodynamic medium is disposed in the housing near to but spaced from the capped end. Heat is pumped along the second thermodynamic medium toward the capped end as a consequence both of the pressure oscillation due to the driver and imperfect thermal contact between the fluid and the second thermodynamic medium. 2 figs.

  10. Deep Water Acoustics

    Science.gov (United States)

    2016-06-28

    the Deep Water project and participate in the NPAL Workshops, including Art Baggeroer (MIT), J. Beron- Vera (UMiami), M. Brown (UMiami), T...Kathleen E . Wage. The North Pacific Acoustic Laboratory deep-water acoustic propagation experiments in the Philippine Sea. J. Acoust. Soc. Am., 134(4...estimate of the angle α during PhilSea09, made from ADCP measurements at the site of the DVLA. Sim. A B1 B2 B3 C D E F Prof. # 0 4 4 4 5 10 16 20 α

  11. Radiation acoustics and its applications

    International Nuclear Information System (INIS)

    Lyamshev, L.M.

    1992-01-01

    Radiation acoustics is a new branch of acoustics, developing on the boundary of acoustics, nuclear physics, elementary particles and high-energy physics. Its fundamentals are laying in the research of acoustical effects due to the interaction of penetrating radiation with matter. The study of radiation-acoustical effects leads to the new opportunities in the penetration radiation research (acoustical detection, radiation-acoustical dosimetry), study of the physical parameters of matter, in a solution of some applied problems of nondestructive testing, and also for the radiation-acoustical influence on physical and chemical structure of the matter. Results of theoretical and experimental investigations are given. Different mechanisms of the sound generation by penetrating radiation of liquids and solids are considered. Some applications - the radiation acoustical microscopy and visualisation, the acoustical detection of high energy X-ray particles and possibility of using of high energy neutrino beams in geoacoustics - are discussed

  12. Acoustic change detection algorithm using an FM radio

    Science.gov (United States)

    Goldman, Geoffrey H.; Wolfe, Owen

    2012-06-01

    The U.S. Army is interested in developing low-cost, low-power, non-line-of-sight sensors for monitoring human activity. One modality that is often overlooked is active acoustics using sources of opportunity such as speech or music. Active acoustics can be used to detect human activity by generating acoustic images of an area at different times, then testing for changes among the imagery. A change detection algorithm was developed to detect physical changes in a building, such as a door changing positions or a large box being moved using acoustics sources of opportunity. The algorithm is based on cross correlating the acoustic signal measured from two microphones. The performance of the algorithm was shown using data generated with a hand-held FM radio as a sound source and two microphones. The algorithm could detect a door being opened in a hallway.

  13. Rapid kinetics of iron responsive element (IRE) RNA/iron regulatory protein 1 and IRE-RNA/eIF4F complexes respond differently to metal ions.

    Science.gov (United States)

    Khan, Mateen A; Ma, Jia; Walden, William E; Merrick, William C; Theil, Elizabeth C; Goss, Dixie J

    2014-06-01

    Metal ion binding was previously shown to destabilize IRE-RNA/IRP1 equilibria and enhanced IRE-RNA/eIF4F equilibria. In order to understand the relative importance of kinetics and stability, we now report rapid rates of protein/RNA complex assembly and dissociation for two IRE-RNAs with IRP1, and quantitatively different metal ion response kinetics that coincide with the different iron responses in vivo. kon, for FRT IRE-RNA binding to IRP1 was eight times faster than ACO2 IRE-RNA. Mn(2+) decreased kon and increased koff for IRP1 binding to both FRT and ACO2 IRE-RNA, with a larger effect for FRT IRE-RNA. In order to further understand IRE-mRNA regulation in terms of kinetics and stability, eIF4F kinetics with FRT IRE-RNA were determined. kon for eIF4F binding to FRT IRE-RNA in the absence of metal ions was 5-times slower than the IRP1 binding to FRT IRE-RNA. Mn(2+) increased the association rate for eIF4F binding to FRT IRE-RNA, so that at 50 µM Mn(2+) eIF4F bound more than 3-times faster than IRP1. IRP1/IRE-RNA complex has a much shorter life-time than the eIF4F/IRE-RNA complex, which suggests that both rate of assembly and stability of the complexes are important, and that allows this regulatory system to respond rapidly to change in cellular iron. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

  14. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... a healthcare provider Request a patient kit Treatment Options Overview Observation Radiation Surgery What is acoustic neuroma Diagnosing Symptoms Side effects Question To Ask Treatment Options Back Overview Observation Radiation Surgery Choosing a healthcare ...

  15. Acoustic-Levitation Chamber

    Science.gov (United States)

    Barmatz, M. B.; Granett, D.; Lee, M. C.

    1984-01-01

    Uncontaminated environments for highly-pure material processing provided within completely sealed levitation chamber that suspends particles by acoustic excitation. Technique ideally suited for material processing in low gravity environment of space.

  16. Acoustic Casimir Effect

    National Research Council Canada - National Science Library

    Homes, Christopher

    1997-01-01

    ...). When the indirect manifestations of the ZPF are interpreted as due to radiation pressure, acoustic noise can provide an excellent analog to investigate the Casimir effect as well as other effects due to the ZPF...

  17. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... a patient kit Treatment Options Overview Observation Radiation Surgery What is acoustic neuroma Diagnosing Symptoms Side effects ... To Ask Treatment Options Back Overview Observation Radiation Surgery Choosing a healthcare provider Request a patient kit ...

  18. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... Choosing a healthcare provider Request a patient kit Treatment Options Overview Observation Radiation Surgery What is acoustic neuroma Diagnosing Symptoms Side effects Question To Ask Treatment Options Back Overview Observation Radiation Surgery Choosing a ...

  19. Acoustic ambient noise recorder

    Digital Repository Service at National Institute of Oceanography (India)

    Saran, A.K.; Navelkar, G.S.; Almeida, A.M.; More, S.R.; Chodankar, P.V.; Murty, C.S.

    with a robust outfit that can withstand high pressures and chemically corrosion resistant materials. Keeping these considerations in view, a CMOS micro-controller-based marine acoustic ambient noise recorder has been developed with a real time clock...

  20. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... Learn more about ANA About ANA Mission, Vision & Values Shop ANA Leadership & Staff Annual Reports Acoustic Neuroma ... 8211 info@ANAUSA.org About ANA Mission, Vision & Values Leadership & Staff Annual Reports Shop ANA Home Learn ...

  1. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... ANA About ANA Mission, Vision & Values Shop ANA Leadership & Staff Annual Reports Acoustic Neuroma Association 600 Peachtree ... info@ANAUSA.org About ANA Mission, Vision & Values Leadership & Staff Annual Reports Shop ANA Home Learn Educational ...

  2. Electrostatic ion acoustic waves

    International Nuclear Information System (INIS)

    Hasegawa, A.

    1983-01-01

    In this paper, certain aspects of plasma physics are illustrated through a study of electrostatic ion acoustic waves. The paper consists of three Sections. Section II deals with linear properties of the ion acoustic wave including derivation of the dispersions relation with the effect of Landau damping and of an ambient magnetic field. The section also introduces the excitation processes of the ion acoustic wave due to an electron drift or to a stimulated Brillouin scattering. The nonlinear properties are introduced in Section III and IV. In Section III, incoherent nonlinear effects such as quasilinear and mode-coupling saturations of the instability are discussed. The coherent nonlinear effects such as the generation of ion acoustic solitons, shocks and weak double layers are presented in Section IV. (Auth.)

  3. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... patient kit Treatment Options Overview Observation Radiation Surgery What is acoustic neuroma Diagnosing ... Back Community Patient Stories Share Your Story Video Stories Caregivers Milestones Gallery Submit Your Milestone Team ANA Volunteer ...

  4. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... Connections Overview Find a Meeting Host a Meeting Volunteer Become a Volunteer Opportunities Support Overview Patient Events ... ANA About ANA Mission, Vision & Values Shop ANA Leadership & Staff Annual Reports Acoustic Neuroma Association 600 Peachtree ...

  5. Autonomous Acoustic Receiver System

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Collects underwater acoustic data and oceanographic data. Data are recorded onboard an ocean buoy and can be telemetered to a remote ship or shore station...

  6. Acoustic MIMO signal processing

    CERN Document Server

    Huang, Yiteng; Chen, Jingdong

    2006-01-01

    A timely and important book addressing a variety of acoustic signal processing problems under multiple-input multiple-output (MIMO) scenarios. It uniquely investigates these problems within a unified framework offering a novel and penetrating analysis.

  7. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... Back Learn more about ANA About ANA Mission, Vision & Values Shop ANA Leadership & Staff Annual Reports Acoustic ... 205-8211 info@ANAUSA.org About ANA Mission, Vision & Values Leadership & Staff Annual Reports Shop ANA Home ...

  8. Thermal Acoustic Fatigue Apparatus

    Data.gov (United States)

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

  9. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... Spanish Washington Support Group Leslie of Stone Mountain, ... Providers Acoustic Neuroma Association Donate Now Newly Diagnosed What is AN? Request a Patient Kit Treatment Options Get Support Find a Provider Discussion Forum ...

  10. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... Mission, Vision & Values Shop ANA Leadership & Staff Annual Reports Acoustic Neuroma Association 600 Peachtree Parkway Suite 108 ... About ANA Mission, Vision & Values Leadership & Staff Annual Reports Shop ANA Home Learn Educational Video English English ...

  11. Acoustic Igniter, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — An acoustic igniter eliminates the need to use electrical energy to drive spark systems to initiate combustion in liquid-propellant rockets. It does not involve the...

  12. Department of Cybernetic Acoustics

    Science.gov (United States)

    The development of the theory, instrumentation and applications of methods and systems for the measurement, analysis, processing and synthesis of acoustic signals within the audio frequency range, particularly of the speech signal and the vibro-acoustic signal emitted by technical and industrial equipments treated as noise and vibration sources was discussed. The research work, both theoretical and experimental, aims at applications in various branches of science, and medicine, such as: acoustical diagnostics and phoniatric rehabilitation of pathological and postoperative states of the speech organ; bilateral ""man-machine'' speech communication based on the analysis, recognition and synthesis of the speech signal; vibro-acoustical diagnostics and continuous monitoring of the state of machines, technical equipments and technological processes.

  13. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... 1 acoustic neuroma resource Click to learn more... LOGIN CALENDAR DONATE NEWS Home Learn Back Learn about ... Webinar Library Newsletter Library Patient Info Booklets Member Login Research ANA Survey/Registry AN Research Patient Registry ...

  14. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... About ANA Mission, Vision & Values Shop ANA Leadership & Staff Annual Reports Acoustic Neuroma Association 600 Peachtree Parkway ... ANAUSA.org About ANA Mission, Vision & Values Leadership & Staff Annual Reports Shop ANA Home Learn Educational Video ...

  15. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... Click to learn more... LOGIN CALENDAR DONATE NEWS Home Learn Back Learn about acoustic neuroma AN Facts ... Vision & Values Leadership & Staff Annual Reports Shop ANA Home Learn Educational Video English English Arabic Catalan Chinese ( ...

  16. Principles of musical acoustics

    CERN Document Server

    Hartmann, William M

    2013-01-01

    Principles of Musical Acoustics focuses on the basic principles in the science and technology of music. Musical examples and specific musical instruments demonstrate the principles. The book begins with a study of vibrations and waves, in that order. These topics constitute the basic physical properties of sound, one of two pillars supporting the science of musical acoustics. The second pillar is the human element, the physiological and psychological aspects of acoustical science. The perceptual topics include loudness, pitch, tone color, and localization of sound. With these two pillars in place, it is possible to go in a variety of directions. The book treats in turn, the topics of room acoustics, audio both analog and digital, broadcasting, and speech. It ends with chapters on the traditional musical instruments, organized by family. The mathematical level of this book assumes that the reader is familiar with elementary algebra. Trigonometric functions, logarithms and powers also appear in the book, but co...

  17. Seven 3d-4f coordination polymers of macrocyclic oxamide with polycarboxylates: Syntheses, crystal structures and magnetic properties

    Energy Technology Data Exchange (ETDEWEB)

    Xin, Na [College of Chemistry, Tianjin Normal University, Tianjin 300387 (China); Key Laboratory of Inorganic-Organic Hybrid Functional Material Chemistry, Ministry of Education (China); Tianjin Key Laboratory of Structure and Performance for Functional Molecules (China); Sun, Ya-Qiu, E-mail: hxxysyq@mail.tjnu.edu.cn [College of Chemistry, Tianjin Normal University, Tianjin 300387 (China); Key Laboratory of Inorganic-Organic Hybrid Functional Material Chemistry, Ministry of Education (China); Tianjin Key Laboratory of Structure and Performance for Functional Molecules (China); Zheng, Yan-Feng; Xu, Yan-Yan; Gao, Dong-Zhao; Zhang, Guo-Ying [College of Chemistry, Tianjin Normal University, Tianjin 300387 (China); Key Laboratory of Inorganic-Organic Hybrid Functional Material Chemistry, Ministry of Education (China); Tianjin Key Laboratory of Structure and Performance for Functional Molecules (China)

    2016-11-15

    Seven new 3d–4f heterometallic coordination polymers, [Ln(CuL){sub 2}(Hbtca)(btca)(H{sub 2}O)]·2H{sub 2}O (Ln = Tb{sup III}1, Pr{sup III}2, Sm{sup III}3, Eu{sup III}4, Yb{sup III}5), [Nd(NiL)(nip)(Rnip)]·0·25H{sub 2}O·0.25CH{sub 3}OH (R= 0.6CH{sub 3}, 0.4H) 6 and [Nd{sub 2}(NiL)(nip){sub 3}(H{sub 2}O)]·2H{sub 2}O 7(CuL or NiL, H{sub 2}L = 2, 3-dioxo-5, 6, 14, 15-dibenzo-1, 4, 8, 12-tetraazacyclo-pentadeca-7, 13-dien; H{sub 2}btca = benzotriazole-5-carboxylic acid; H{sub 2}nip = 5-nitroisophthalic acid) have been synthesized by a solvothermal method and characterized by single-crystal X-ray diffraction. Complexes 1–5 exhibit a double-strand meso-helical chain structures formed by [Ln{sup III}Cu{sup II}{sub 2}] units via the oxamide and benzotriazole-5-carboxylate bridges, while complex 6 exhibits a four-strand meso-helical chain formed by NdNi unit via the oxamide and 5-nitroisophthalate bridges. Complex 7 consists of a 2D layer framework formed by four-strand meso-helical chain via the nip{sup 2−} bridges. Moreover, the magnetic properties of them were investigated, and the best-fit analysis of χ{sub M}T versus T show that the anisotropic contribution of Ln(III) ions (arising from the spin-orbit coupling or the crystal field perturbation) dominates (weak exchange limit) in these complexes(for 3, λ = 214.6 cm{sup −1}, zj’ = −0.33 cm{sup −1}, g{sub av} = 1.94; for 5, Δ = 6.98 cm{sup −1}, zj’ = 1.53 cm{sup −1}, g{sub av} = 1.85). - Graphical-abstract: Seven novel oxamido-bridged 3d-4f heterometallic coordination polymers with benzotriazole-5-carboxylate or 5-nitroisophthalate co-ligands under solvothermal reaction conditions. Polymers 1–7 hold 1D or 2D framework structure, viz., double-strand meso-helical chain of 1–5, four-strand meso-helical chain of 6, and 2D net of 7 consisting of four-strand meso-helical chain. Moreover, the temperature dependences of magnetic susceptibilities of compounds 1–7 were also studied.

  18. Theoretical modeling of the uranium 4f XPS for U(VI) and U(IV) oxides

    Energy Technology Data Exchange (ETDEWEB)

    Bagus, Paul S. [Department of Chemistry, University of North Texas, Denton, Texas 76203-5017 (United States); Nelin, Connie J. [Consulting and Services, 6008 Maury' s Trail, Austin, Texas 78730 (United States); Ilton, Eugene S. [Pacific Northwest National Laboratory, Richland, Washington 99352 (United States)

    2013-12-28

    A rigorous study is presented of the physical processes related to X-Ray photoelectron spectroscopy, XPS, in the 4f level of U oxides, which, as well as being of physical interest in themselves, are representative of XPS in heavy metal oxides. In particular, we present compelling evidence for a new view of the screening of core-holes that extends prior understandings. Our analysis of the screening focuses on the covalent mixing of high lying U and O orbitals as opposed to the, more common, use of orbitals that are nominally pure U or pure O. It is shown that this covalent mixing is quite different for the initial and final, core-hole, configurations and that this difference is directly related to the XPS satellite intensity. Furthermore, we show that the high-lying U d orbitals as well as the U(5f) orbital may both contribute to the core-hole screening, in contrast with previous work that has only considered screening through the U(5f) shell. The role of modifying the U-O interaction by changing the U-O distance has been investigated and an unexpected correlation between U-O distance and XPS satellite intensity has been discovered. The role of flourite and octahedral crystal structures for U(IV) oxides has been examined and relationships established between XPS features and the covalent interactions in the different structures. The physical views of XPS satellites as arising from shake processes or as arising from ligand to metal charge transfers are contrasted; our analysis provides strong support that shake processes give a more fundamental physical understanding than charge transfer. Our theoretical studies are based on rigorous, strictly ab initio determinations of the electronic structure of embedded cluster models of U oxides with formal U(VI) and U(IV) oxidation states. Our results provide a foundation that makes it possible to establish quantitative relationships between features of the XPS spectra and materials properties.

  19. Theoretical modeling of the uranium 4f XPS for U(VI) and U(IV) oxides

    Science.gov (United States)

    Bagus, Paul S.; Nelin, Connie J.; Ilton, Eugene S.

    2013-12-01

    A rigorous study is presented of the physical processes related to X-Ray photoelectron spectroscopy, XPS, in the 4f level of U oxides, which, as well as being of physical interest in themselves, are representative of XPS in heavy metal oxides. In particular, we present compelling evidence for a new view of the screening of core-holes that extends prior understandings. Our analysis of the screening focuses on the covalent mixing of high lying U and O orbitals as opposed to the, more common, use of orbitals that are nominally pure U or pure O. It is shown that this covalent mixing is quite different for the initial and final, core-hole, configurations and that this difference is directly related to the XPS satellite intensity. Furthermore, we show that the high-lying U d orbitals as well as the U(5f) orbital may both contribute to the core-hole screening, in contrast with previous work that has only considered screening through the U(5f) shell. The role of modifying the U-O interaction by changing the U-O distance has been investigated and an unexpected correlation between U-O distance and XPS satellite intensity has been discovered. The role of flourite and octahedral crystal structures for U(IV) oxides has been examined and relationships established between XPS features and the covalent interactions in the different structures. The physical views of XPS satellites as arising from shake processes or as arising from ligand to metal charge transfers are contrasted; our analysis provides strong support that shake processes give a more fundamental physical understanding than charge transfer. Our theoretical studies are based on rigorous, strictly ab initio determinations of the electronic structure of embedded cluster models of U oxides with formal U(VI) and U(IV) oxidation states. Our results provide a foundation that makes it possible to establish quantitative relationships between features of the XPS spectra and materials properties.

  20. Anal acoustic reflectometry

    DEFF Research Database (Denmark)

    Mitchell, Peter J; Klarskov, Niels; Telford, Karen J

    2011-01-01

    Anal acoustic reflectometry is a new technique of assessing anal sphincter function. Five new variables reflecting anal canal function are measured: the opening and closing pressure, the opening and closing elastance, and hysteresis.......Anal acoustic reflectometry is a new technique of assessing anal sphincter function. Five new variables reflecting anal canal function are measured: the opening and closing pressure, the opening and closing elastance, and hysteresis....

  1. C20H4(C4F8)3: a fluorine-containing annulated corannulene that is a better electron acceptor than C60.

    Science.gov (United States)

    Kuvychko, Igor V; Dubceac, Cristina; Deng, Shihu H M; Wang, Xue-Bin; Granovsky, Alexander A; Popov, Alexey A; Petrukhina, Marina A; Strauss, Steven H; Boltalina, Olga V

    2013-07-15

    At sixes and sevens: The reaction of corannulene with 35 equivalents of 1,4-C4F8I2 is an efficient and a relatively selective process that yields two main products in which six H atoms are substituted with three C4F8 moieties that form six- and seven-membered rings. Low-temperature photoelectron spectroscopy showed the electron affinity of the major isomer (shown) exceeds that of C60 (2.74±0.02 and 2.689±0.008 eV, respectively). Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Synthesis, structure and electrochemical properties of LiNaCo{sub 0.5}Fe{sub 0.5}PO{sub 4}F fluoride-phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Fedotov, Stanislav S. [Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow (Russian Federation); Skoltech Center for Electrochemical Energy Storage, Skolkovo Institute of Science and Technology, 143026 Moscow (Russian Federation); Kuzovchikov, Sergey M.; Khasanova, Nellie R.; Drozhzhin, Oleg A.; Filimonov, Dmitriy S. [Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow (Russian Federation); Karakulina, Olesia M.; Hadermann, Joke [EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Abakumov, Artem M. [Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow (Russian Federation); Skoltech Center for Electrochemical Energy Storage, Skolkovo Institute of Science and Technology, 143026 Moscow (Russian Federation); EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Antipov, Evgeny V. [Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow (Russian Federation)

    2016-10-15

    LiNaCo{sub 0.5}Fe{sub 0.5}PO{sub 4}F fluoride-phosphate was synthesized via conventional solid-state and novel freeze-drying routes. The crystal structure was refined based on neutron powder diffraction (NPD) data and validated by electron diffraction (ED) and high-resolution transmission electron microscopy (HRTEM). The alkali ions are ordered in LiNaCo{sub 0.5}Fe{sub 0.5}PO{sub 4}F and the transition metals jointly occupy the same crystallographic sites. The oxidation state and oxygen coordination environment of the Fe atoms were verified by {sup 57}Fe Mössbauer spectroscopy. Electrochemical tests of the LiNaCo{sub 0.5}Fe{sub 0.5}PO{sub 4}F cathode material demonstrated a reversible activity of the Fe{sup 3+}/Fe{sup 2+} redox couple at the electrode potential near 3.4 V and minor activity of the Co{sup 3+}/Co{sup 2+} redox couple over 5 V vs Li/Li{sup +}. The material exhibited the discharge capacity of more than 82% (theo.) regarding Fe{sup 3+}/Fe{sup 2+} in the 2.4÷4.6 V vs Li/Li{sup +} potential range. - Graphical abstract: The ball-polyhedral representation of the LiNaCo{sub 0.5}Fe{sub 0.5}PO{sub 4}F crystal structure. The MO{sub 4}F{sub 2} units are depicted as blue octahedra, PO{sub 4} units as orange tetrahedra, sodium atoms are designated as yellow (Na1), lithium – red and brown (Li2, Li3 resp.), fluorine – green, oxygen – violet spheres. - Highlights: • Freeze-drying method was successfully applied to the synthesis of LiNaCo{sub 0.5}Fe{sub 0.5}PO{sub 4}F. • The crystal structure of LiNaCo{sub 0.5}Fe{sub 0.5}PO{sub 4}F was refined based on NPD and validated by ED and HRTEM. • LiNaCo{sub 0.5}Fe{sub 0.5}PO{sub 4}F demonstrated a reversible Li de/intercalation in the 2.5÷4.6 V vs Li/Li{sup +} range.

  3. Luminescence of Ce3+ doped LaPO4 nanophosphors upon Ce3+ 4f-5d and band-to-band excitation

    International Nuclear Information System (INIS)

    Stryganyuk, G.; Trots, D.M.; Voloshinovskii, A.; Shalapska, T.; Zakordonskiy, V.; Vistovskyy, V.; Pidzyrailo, M.; Zimmerer, G.

    2008-01-01

    Luminescence spectral-kinetic studies have been performed for pure and Ce-doped LaPO 4 micro- and nanosized phosphates using synchrotron radiation for the excitation within 5-20 eV energy range at T=8-300 K. Mechanisms for the excitation of Ce 3+ 5d-4f emission as well as the quenching processes are discussed. The influence of surface defects has been considered to modify considerably the luminescent properties of nanosized phosphors upon the excitation in the energy range of Ce 3+ 4f-5d transitions and LaPO 4 host absorption

  4. Acoustic calibration apparatus for calibrating plethysmographic acoustic pressure sensors

    Science.gov (United States)

    Zuckerwar, Allan J. (Inventor); Davis, David C. (Inventor)

    1995-01-01

    An apparatus for calibrating an acoustic sensor is described. The apparatus includes a transmission material having an acoustic impedance approximately matching the acoustic impedance of the actual acoustic medium existing when the acoustic sensor is applied in actual in-service conditions. An elastic container holds the transmission material. A first sensor is coupled to the container at a first location on the container and a second sensor coupled to the container at a second location on the container, the second location being different from the first location. A sound producing device is coupled to the container and transmits acoustic signals inside the container.

  5. Acoustic window planning for ultrasound acquisition.

    Science.gov (United States)

    Göbl, Rüdiger; Virga, Salvatore; Rackerseder, Julia; Frisch, Benjamin; Navab, Nassir; Hennersperger, Christoph

    2017-06-01

    Autonomous robotic ultrasound has recently gained considerable interest, especially for collaborative applications. Existing methods for acquisition trajectory planning are solely based on geometrical considerations, such as the pose of the transducer with respect to the patient surface. This work aims at establishing acoustic window planning to enable autonomous ultrasound acquisitions of anatomies with restricted acoustic windows, such as the liver or the heart. We propose a fully automatic approach for the planning of acquisition trajectories, which only requires information about the target region as well as existing tomographic imaging data, such as X-ray computed tomography. The framework integrates both geometrical and physics-based constraints to estimate the best ultrasound acquisition trajectories with respect to the available acoustic windows. We evaluate the developed method using virtual planning scenarios based on real patient data as well as for real robotic ultrasound acquisitions on a tissue-mimicking phantom. The proposed method yields superior image quality in comparison with a naive planning approach, while maintaining the necessary coverage of the target. We demonstrate that by taking image formation properties into account acquisition planning methods can outperform naive plannings. Furthermore, we show the need for such planning techniques, since naive approaches are not sufficient as they do not take the expected image quality into account.

  6. New nonlinear-laser properties of ferroelectric Nd3+:Ba2NaNb5O15 - cw stimulated emission (4F3/2 → 4I11/2 and 4F3/2 → 4I13/2 ), collinear and diffuse self-frequency doubling and summation

    International Nuclear Information System (INIS)

    Kaminskii, Alexandr A; Jaque, D; Garsia, Sole J; Capmany, J; Bagayev, S N; Ueda, Ken-ichi

    1999-01-01

    A new cw laser with self-frequency doubling and summation of 1-μm oscillation ( 4 F 3/2 → 4 I 11/2 ) was constructed on the basis of an orthorhombic Nd 3+ :Ba 2 NaNb 5 O 15 crystal. The 4 F 3/2 → 4 I 13/2 inter-Stark transition was used to excite cw 1.3-μm stimulated emission from this ferroelectric. (letters to the editor)

  7. Acoustically induced transparency using Fano resonant periodic arrays

    KAUST Repository

    El-Amin, Mohamed

    2015-10-22

    A three-dimensional acoustic device, which supports Fano resonance and induced transparency in its response to an incident sound wave, is designed and fabricated. These effects are generated from the destructive interference of closely coupled one broad- and one narrow-band acoustic modes. The proposed design ensures excitation and interference of two spectrally close modes by locating a small pipe inside a wider and longer one. Indeed, numerical simulations and experiments demonstrate that this simple-to-fabricate structure can be used to generate Fano resonance as well as acoustically induced transparency with promising applications in sensing, cloaking, and imaging.

  8. Acoustically induced transparency using Fano resonant periodic arrays

    KAUST Repository

    El-Amin, Mohamed; Elayouch, A.; Farhat, Mohamed; Addouche, M.; Khelif, A.; Bagci, Hakan

    2015-01-01

    A three-dimensional acoustic device, which supports Fano resonance and induced transparency in its response to an incident sound wave, is designed and fabricated. These effects are generated from the destructive interference of closely coupled one broad- and one narrow-band acoustic modes. The proposed design ensures excitation and interference of two spectrally close modes by locating a small pipe inside a wider and longer one. Indeed, numerical simulations and experiments demonstrate that this simple-to-fabricate structure can be used to generate Fano resonance as well as acoustically induced transparency with promising applications in sensing, cloaking, and imaging.

  9. Acoustic comfort in eating establishments

    DEFF Research Database (Denmark)

    Svensson, David; Jeong, Cheol-Ho; Brunskog, Jonas

    2014-01-01

    The subjective concept of acoustic comfort in eating establishments has been investigated in this study. The goal was to develop a predictive model for the acoustic comfort, by means of simple objective parameters, while also examining which other subjective acoustic parameters could help explain...... the feeling of acoustic comfort. Through several layers of anal ysis, acoustic comfort was found to be rather complex, and could not be explained entirely by common subjective parameters such as annoyance, intelligibility or privacy. A predictive model for the mean acoustic comfort for an eating establishment...

  10. Correlation and relativistic effects for the 4f-nl and 5p-nl multipole transitions in Er-like tungsten

    International Nuclear Information System (INIS)

    Safronova, U. I.; Safronova, A. S.

    2011-01-01

    Wavelengths, transition rates, and line strengths are calculated for the multipole (E1, M1, E2, M2, E3, and M3) transitions between the excited [Cd]4f 13 5p 6 nl, [Cd]4f 14 5p 5 nl configurations and the ground [Cd]4f 14 5p 6 state in Er-like W 6+ ion ([Cd]=[Kr]4d 10 5s 2 ). In particular, the relativistic many-body perturbation theory (RMBPT), including the Breit interaction, is used to evaluate energies and transition rates for multipole transitions in this hole-particle system. This method is based on the relativistic many-body perturbation theory that agrees with multiconfiguration Dirac-Fock (MCDF) calculations in lowest order, and includes all second-order correlation corrections and corrections from negative-energy states. The calculations start from a [Cd]4f 14 5p 6 Dirac-Fock (DF) potential. First-order perturbation theory is used to obtain intermediate-coupling coefficients, and second-order RMBPT is used to determine the multipole matrix elements needed for calculations of other atomic properties such as line strengths and transition rates. In addition, core multipole polarizability is evaluated in random-phase and DF approximations. The comparison with available data is demonstrated.

  11. High-precision, systematic study of hyperfine structure in the 4f/sup N/6s2 configuration of the neutral rare earths

    International Nuclear Information System (INIS)

    Childs, W.J.; Goodman, L.S.; Pfeufer, V.

    1983-01-01

    Although the hyperfine structure (hfs) of many-electron atoms has been studied intensively in recent years, it is still difficult to distinguish between the competing effects of relativity and configuration interaction. The 4f/sup N/6s 2 configuration of the neutral rare earths is of particular interest because (a) the low-lying terms are relatively free of configuration interaction, and (b) trends can be examined systematically as one proceeds through the long 4f-shell. The procedure is to deduce, from the measured hfs constants of low levels, the underlying hyperfine radial integrals for comparison with ab initio predictions. Since some of these integrals are extremely sensitive to any configuration interaction and others are not, it is possible to determine both the extent and type of configuration interaction present in some cases. Prior to the start of the present research no precise hfs information existed for the entire second half of the 4f shell of the rare earths. The present measurements were designed both to provide such data and to make possible a systematic study of the hfs throughout the 4f shell. The atomic-beam, laser-rf, double-resonance method was used for the measurements. With this technique, the occurrence of a radiofrequency transition between atomic hfs levels is detected by noting an increase in the laser-induced fluorescence

  12. Generation of human iPSC line GRX-MCiPS4F-A2 from adult peripheral blood mononuclear cells (PBMCs with Spanish genetic background

    Directory of Open Access Journals (Sweden)

    Sonia Cabrera

    2015-09-01

    Full Text Available We have generated iPSCs from peripheral blood mononuclear cells (PBMCs of a healthy man using heat sensitive and non-integrative Sendai virus containing Sox2, Oct3/4, c-Myc and Klf4. Human GRX-MCiPS4F-A2 cell line was established and characterized through this study.

  13. Synthesis of carbon-coated Na2MnPO4F hollow spheres as a potential cathode material for Na-ion batteries

    Science.gov (United States)

    Wu, Ling; Hu, Yong; Zhang, Xiaoping; Liu, Jiequn; Zhu, Xing; Zhong, Shengkui

    2018-01-01

    Hollow sphere structure Na2MnPO4F/C composite is synthesized through spray drying, following in-situ pyrolytic carbon coating process. XRD results indicate that the well crystallized composite can be successfully synthesized, and no other impurity phases are detected. SEM and TEM results reveal that the Na2MnPO4F/C samples show intact hollow spherical architecture, and the hollow spherical shells with an average thickness of 150 nm-250 nm are composed of nanosized primary particles. Furthermore, the amorphous carbon layer is uniformly coated on the surface of the hollow sphere, and the nanosized Na2MnPO4F particles are well embedded in the carbon networks. Consequently, the hollow sphere structure Na2MnPO4F/C shows enhanced electrochemical performance. Especially, it is the first time that the obvious potential platforms (∼3.6 V) are observed during the charge and discharge process at room temperature.

  14. 28 CFR Appendix to Part 55 - Jurisdictions Covered Under Sections 4(f)(4) and 203(c) of the Voting Rights Act of 1965, as Amended

    Science.gov (United States)

    2010-07-01

    ... REGARDING LANGUAGE MINORITY GROUPS Pt. 55, App. Appendix to Part 55—Jurisdictions Covered Under Sections 4(f...)(4) and 203(c) of the Voting Rights Act of 1965, as Amended [Applicable language minority group(s... (Chinese, Filipino, Japanese, Vietnamese), Spanish heritage. Merced County Spanish heritage Monterey County...

  15. Millimeter waves: acoustic and electromagnetic.

    Science.gov (United States)

    Ziskin, Marvin C

    2013-01-01

    This article is the presentation I gave at the D'Arsonval Award Ceremony on June 14, 2011 at the Bioelectromagnetics Society Annual Meeting in Halifax, Nova Scotia. It summarizes my research activities in acoustic and electromagnetic millimeter waves over the past 47 years. My earliest research involved acoustic millimeter waves, with a special interest in diagnostic ultrasound imaging and its safety. For the last 21 years my research expanded to include electromagnetic millimeter waves, with a special interest in the mechanisms underlying millimeter wave therapy. Millimeter wave therapy has been widely used in the former Soviet Union with great reported success for many diseases, but is virtually unknown to Western physicians. I and the very capable members of my laboratory were able to demonstrate that the local exposure of skin to low intensity millimeter waves caused the release of endogenous opioids, and the transport of these agents by blood flow to all parts of the body resulted in pain relief and other beneficial effects. Copyright © 2012 Wiley Periodicals, Inc.

  16. Structural distortions in Sr3-xAxMO4F (A=Ca, Ba; M=Al, Ga, In) anti-Perovskites and corresponding changes in photoluminescence

    International Nuclear Information System (INIS)

    Sullivan, Eirin; Avdeev, Maxim; Vogt, Thomas

    2012-01-01

    The ordered oxyfluoride family Sr 3 − x A x MO 4 F (A=Ca, Ba and M=Al, Ga) has formed the basis of several new inorganic phosphors, and shows great potential for use in phosphor-conversion LED lamp devices. This study examines the correlation between subtle structural changes and photoluminescent behaviour in some of these materials. In order to ascertain whether cation charge compensation has any influence on structure and subsequent photoluminescent behaviour, a comparison was carried out between phases with the nominal compositions Sr 2.975 Ce 0.025 AlO 4 F and Sr 2.95 Ce 0.025 Na 0.025 AlO 4 F using structural characterisation based upon high-resolution neutron powder diffraction (NPD) data. Additionally, NPD data has been used to elucidate the role of different M cations in these materials, using Sr 2.25 Ba 0.6 Eu 0.1 M 0.95 In 0.05 O 4−α F 1−δ (M=Al, Ga) to determine the effect M cation size has on structure and photoluminescent properties. - Graphical abstract: The structure of Sr3-xAxMO4F (A=Ca, Ba and M=Al, Ga) and excitation and emission spectra for Sr 2.25 Ba 0.6 Eu 0.1 Ga 0.95 In 0.05 O 4−α F 1−δ . Highlights: ► Correlation between structural changes and photoluminescence in Sr 3−x A x MO 4 F (A=Ca, Ba, M=Al, Ga). ► Comparison of Sr 2.975 Ce 0.025 AlO 4 F and Sr 2.95 Ce 0.025 Na 0.025 AlO 4 F using high-resolution NPD. ► Study of the effect of cation charge-compensation on structure and photoluminescent behaviour. ► Examination of high-resolution NPD data for Sr 2.25 Ba 0.6 Eu 0.1 M 0.95 In 0.05 O 4−α F 1−δ (M=Al, Ga). ► Determination of the effect M cation size has on structure and photoluminescent properties.

  17. Tunable luminescence in Bi{sup 3+} and Eu{sup 3+} co-doped Sr{sub 3}AlO{sub 4}F Oxyfluorides phosphors

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Minhee [Center for Green Fusion Technology and Department of Engineering in Energy & Applied Chemistry, Silla University, Busan 617-736 (Korea, Republic of); Cho, So-Hye [Center for Materials Architecturing, Institute of Multidisciplinary Convergence of Materials, Korea Institute of Science and Technology, Seoul 130-650 (Korea, Republic of); Park, Sangmoon, E-mail: spark@silla.ac.kr [Center for Green Fusion Technology and Department of Engineering in Energy & Applied Chemistry, Silla University, Busan 617-736 (Korea, Republic of)

    2015-05-15

    Luminescent materials composed of Sr{sub 3−3(m+n)/2}Bi{sub m}Eu{sub n}AlO{sub 4}F (m=0.001–0.05, n=0–0.1) were prepared by the solid-state reaction method. The excitation and emission spectra of Sr{sub 3−3m/2}Bi{sub m}AlO{sub 4}F (m=0.001–0.05) were investigated using photoluminescence spectroscopy; broad-band emission peaks owing to the {sup 3}P{sub 1}→{sup 1}S{sub 0} transitions of the Bi{sup 3+} activator were observed centered near 427 nm. Critical emission quenching, as a function of Bi{sup 3+} content in Sr{sub 3−3m/2}Bi{sub m}AlO{sub 4}F, was observed at relatively low concentrations of the activator. The quantum efficiency of Sr{sub 2.985}Bi{sub 0.01}AlO{sub 4}F in comparison with sodium salicylate was explored. When Sr{sup 2+} ions in the oxyfluoride host were replaced by Bi{sup 3+} and Eu{sup 3+} ions, the effective s{sup 2}–sp and f–f transitions of the Bi{sup 3+} and Eu{sup 3+} ions, respectively, were simultaneously observed. The diverse excitation and emission photoluminescence spectra and color CIE coordinates, as well as the blue to orange-red emission, obtained using Sr{sub 3−3(m+n)/2}Bi{sub m}Eu{sub n}AlO{sub 4}F (m=0–0.05, n=0–0.1) phosphors are also discussed. - Highlights: • Sr{sub 3−3(m+n)/2}Bi{sub m}Eu{sub n}AlO{sub 4}F (m=0.001–0.05, n=0–0.1) phosphors was prepared. • Emission owing to the {sup 3}P{sub 1}→{sup 1}S{sub 0} transitions of the Bi{sup 3+} activator was observed. • Quantum efficiency of Sr{sub 2.985}Bi{sub 0.01}AlO{sub 4}F was explored. • s{sup 2}–sp and f–f transitions of the Bi{sup 3+} and Eu{sup 3+} ions were simultaneously observed. • CIE values including the emissions from blue to red regions were achieved.

  18. Preliminary characterization of a one-axis acoustic system. [acoustic levitation for space processing

    Science.gov (United States)

    Oran, W. A.; Reiss, D. A.; Berge, L. H.; Parker, H. W.

    1979-01-01

    The acoustic fields and levitation forces produced along the axis of a single-axis resonance system were measured. The system consisted of a St. Clair generator and a planar reflector. The levitation force was measured for bodies of various sizes and geometries (i.e., spheres, cylinders, and discs). The force was found to be roughly proportional to the volume of the body until the characteristic body radius reaches approximately 2/k (k = wave number). The acoustic pressures along the axis were modeled using Huygens principle and a method of imaging to approximate multiple reflections. The modeled pressures were found to be in reasonable agreement with those measured with a calibrated microphone.

  19. Translation initiation complex eIF4F is a therapeutic target for dual mTOR kinase inhibitors in non-Hodgkin lymphoma

    Science.gov (United States)

    Stenson, Mary J.; Maurer, Matthew J.; Wellik, Linda E.; Link, Brian; Hege, Kristen; Dogan, Ahmet; Sotomayor, Eduardo; Witzig, Thomas; Gupta, Mamta

    2015-01-01

    Deregulated mRNA translation has been implicated in disease development and in part is controlled by a eukaryotic initiation complex eIF4F (composed of eIF4E, eIF4G and eIF4A). We demonstrate here that the cap bound fraction from lymphoma cells was enriched with eIF4G and eIF4E indicating that lymphoma cells exist in an activated translational state. Moreover, 77% (110/142) of diffuse large B cell lymphoma tumors expressed eIF4E and this was associated with an inferior event free survival. Over-expression of wild-type eIF4E (eIF4EWT) but not cap-mutant eIF4E (eIF4Ecap mutant) increased the activation of the eIF4F complex. Treatment with the active-site dual mTOR inhibitor CC214-1 reduced the level of the eIF4F complex by decreasing the cap bound fraction of eIF4G and increasing the levels of 4E-BP1. CC214-1 inhibited both the cap dependent and global protein translation. CC214-1 inhibited c-Myc, and cyclin D3 translation by decreasing polysomal fractions from lymphoma cells. Inhibition of eIF4E with shRNA further decreased the CC214-1 induced inhibition of the eIF4F complex, c-Myc, cyclin D3 translation, and colony formation. These studies demonstrate that the eIF4F complex is deregulated in aggressive lymphoma and that dual mTOR therapy has therapeutic potential in these patients. PMID:25839159

  20. Genetic Variation in POU4F3 and GRHL2 Associated with Noise-Induced Hearing Loss in Chinese Population: A Case-Control Study

    Directory of Open Access Journals (Sweden)

    Xiangrong Xu

    2016-06-01

    Full Text Available Noise-induced hearing loss (NIHL is an important occupational disease worldwide resulting from interactions between genetic and environmental factors. The purpose of this study was to examine whether genetic variations in POU4F3 and GRHL2 may influence susceptibility to NIHL in the Chinese population. A matched case-control study was carried out among 293 hearing loss individuals and 293 normal hearing workers drawn from a population of 3790 noise-exposed workers. Ten single-nucleotide polymorphisms (SNPs in POU4F3 and GRHL2 were selected and genotyped. Logistic regression was performed to analyze the main effects of SNPs and the interactions between noise exposure and SNPs. Moreover, the interactions between predictor haplotypes and noise exposure were also analyzed. Analysis revealed that the CC genotype of rs1981361 in the GRHL2 gene was associated with a higher risk of NIHL (adjusted OR = 1.59; 95% CI: 1.08–2.32, p = 0.018. Additionally, the GG genotype of rs3735715 in the GRHL2 gene was also a risk genotype (adjusted OR = 1.48; 95% CI: 1.01–2.19, p = 0.046. Significant interactions were found between rs3735715, rs1981361 (GRHL2, rs1368402 as well as rs891969 (POU4F3 and noise exposure in the high-level exposure groups. Furthermore, the protective haplotype CA in the POU4F3 gene and the risk haplotype GCCG in the GRHL2 gene were identified combined with noise exposure. These results indicated that GRHL2 might be an NIHL susceptibility gene, but the effect of POU4F3 on NIHL could only be detected when taking noise exposure into account, and their effects were enhanced by higher levels of noise exposure. However, the differences were not significant after the Bonferroni correction was applied. These results should be seen as suggestive.

  1. A Green Route to a Na2FePO4F-Based Cathode for Sodium Ion Batteries of High Rate and Long Cycling Life.

    Science.gov (United States)

    Deng, Xiang; Shi, Wenxiang; Sunarso, Jaka; Liu, Meilin; Shao, Zongping

    2017-05-17

    Sodium ion batteries (SIBs) are considered one of the most promising alternatives for large-scale energy storage due largely to the abundance and low cost of sodium. However, the lack of high-performance cathode materials at low cost represents a major obstacle toward broad commercialization of SIB technology. In this work, we report a green route strategy that allows cost-effective fabrication of carbon-coated Na 2 FePO 4 F cathode for SIBs. By using vitamin C as a green organic carbon source and environmentally friendly water-based polyacrylic latex as the binder, we have demonstrated that the Na 2 FePO 4 F phase in the as-derived Na 2 FePO 4 F/C electrode shows a high reversible capacity of 117 mAh g -1 at a cycling rate of 0.1 C. More attractively, excellent rate capability is achieved while retaining outstanding cycling stability (∼85% capacity retention after 1000 charge-discharge cycles at a rate of 4 C). Further, in operando X-ray diffraction has been used to probe the evolution of phase structures during the charge-discharge process, confirming the structural robustness of the Na 2 FePO 4 F/C cathode (even when charged to 4.5 V). Accordingly, the poor initial Coulombic efficiency of some anode materials may be compensated by extracting more sodium ions from Na 2 FePO 4 F/C cathode at higher potentials (up to 4.5 V).

  2. Resonant acoustic radiation force optical coherence elastography

    OpenAIRE

    Qi, Wenjuan; Li, Rui; Ma, Teng; Li, Jiawen; Kirk Shung, K.; Zhou, Qifa; Chen, Zhongping

    2013-01-01

    We report on a resonant acoustic radiation force optical coherence elastography (ARF-OCE) technique that uses mechanical resonant frequency to characterize and identify tissues of different types. The linear dependency of the resonant frequency on the square root of Young's modulus was validated on silicone phantoms. Both the frequency response spectrum and the 3D imaging results from the agar phantoms with hard inclusions confirmed the feasibility of deploying the resonant frequency as a mec...

  3. Advanced Active Acoustics Lab (AAAL)

    Data.gov (United States)

    Federal Laboratory Consortium — The Advanced Active Acoustics Lab (AAAL) is a state-of-the-art Undersea Warfare (USW) acoustic data analysis facility capable of both active and passive underwater...

  4. Sea Turtle Acoustic Telemetry Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Acoustic transmitters attached to sea turtles captured in various fishing gear enable the animals to be passively tracked. Acoustic receivers set up in an array...

  5. Perspective: Acoustic metamaterials in transition

    KAUST Repository

    Wu, Ying; Yang, Min; Sheng, Ping

    2017-01-01

    Acoustic metamaterials derive their novel characteristics from the interaction between acoustic waves with designed structures. Since its inception seventeen years ago, the field has been driven by fundamental geometric and physical principles

  6. A Century of Acoustic Metrology

    DEFF Research Database (Denmark)

    Rasmussen, Knud

    1998-01-01

    The development in acoustic measurement technique over the last century is reviewed with special emphasis on the metrological aspect.......The development in acoustic measurement technique over the last century is reviewed with special emphasis on the metrological aspect....

  7. Acoustic Levitation Containerless Processing

    Science.gov (United States)

    Whymark, R. R.; Rey, C. A.

    1985-01-01

    This research program consists of the development of acoustic containerless processing systems with applications in the areas of research in material sciences, as well as the production of new materials, solid forms with novel and unusual microstructures, fusion target spheres, and improved optical fibers. Efforts have been focused on the containerless processing at high temperatures for producing new kinds of glasses. Also, some development has occurred in the areas of containerlessly supporting liquids at room temperature, with applications in studies of fluid dynamics, potential undercooling of liquids, etc. The high temperature area holds the greatest promise for producing new kinds of glasses and ceramics, new alloys, and possibly unusual structural shapes, such as very uniform hollow glass shells for fusion target applications. High temperature acoustic levitation required for containerless processing has been demonstrated in low-g environments as well as in ground-based experiments. Future activities include continued development of the signals axis acoustic levitator.

  8. Practical acoustic emission testing

    CERN Document Server

    2016-01-01

    This book is intended for non-destructive testing (NDT) technicians who want to learn practical acoustic emission testing based on level 1 of ISO 9712 (Non-destructive testing – Qualification and certification of personnel) criteria. The essential aspects of ISO/DIS 18436-6 (Condition monitoring and diagnostics of machines – Requirements for training and certification of personnel, Part 6: Acoustic Emission) are explained, and readers can deepen their understanding with the help of practice exercises. This work presents the guiding principles of acoustic emission measurement, signal processing, algorithms for source location, measurement devices, applicability of testing methods, and measurement cases to support not only researchers in this field but also and especially NDT technicians.

  9. Topological Acoustic Delay Line

    Science.gov (United States)

    Zhang, Zhiwang; Tian, Ye; Cheng, Ying; Wei, Qi; Liu, Xiaojun; Christensen, Johan

    2018-03-01

    Topological protected wave engineering in artificially structured media is at the frontier of ongoing metamaterials research that is inspired by quantum mechanics. Acoustic analogues of electronic topological insulators have recently led to a wealth of new opportunities in manipulating sound propagation with strikingly unconventional acoustic edge modes immune to backscattering. Earlier fabrications of topological insulators are characterized by an unreconfigurable geometry and a very narrow frequency response, which severely hinders the exploration and design of useful devices. Here we establish topologically protected sound in reconfigurable phononic crystals that can be switched on and off simply by rotating its three-legged "atoms" without altering the lattice structure. In particular, we engineer robust phase delay defects that take advantage of the ultrabroadband reflection-free sound propagation. Such topological delay lines serve as a paradigm in compact acoustic devices, interconnects, and electroacoustic integrated circuits.

  10. Acoustic detection of pneumothorax

    Science.gov (United States)

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

    2003-04-01

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

  11. Acoustics waves and oscillations

    CERN Document Server

    Sen, S.N.

    2013-01-01

    Parameters of acoustics presented in a logical and lucid style Physical principles discussed with mathematical formulations Importance of ultrasonic waves highlighted Dispersion of ultrasonic waves in viscous liquids explained This book presents the theory of waves and oscillations and various applications of acoustics in a logical and simple form. The physical principles have been explained with necessary mathematical formulation and supported by experimental layout wherever possible. Incorporating the classical view point all aspects of acoustic waves and oscillations have been discussed together with detailed elaboration of modern technological applications of sound. A separate chapter on ultrasonics emphasizes the importance of this branch of science in fundamental and applied research. In this edition a new chapter ''Hypersonic Velocity in Viscous Liquids as revealed from Brillouin Spectra'' has been added. The book is expected to present to its readers a comprehensive presentation of the subject matter...

  12. Photo-acoustic and video-acoustic methods for sensing distant sound sources

    Science.gov (United States)

    Slater, Dan; Kozacik, Stephen; Kelmelis, Eric

    2017-05-01

    , doing so requires overcoming significant limitations typically including much lower sample rates, reduced sensitivity and dynamic range, more expensive video hardware, and the need for sophisticated video processing. The ATCOM real time image processing software environment provides many of the needed capabilities for researching video-acoustic signal extraction. ATCOM currently is a powerful tool for the visual enhancement of atmospheric turbulence distorted telescopic views. In order to explore the potential of acoustic signal recovery from video imagery we modified ATCOM to extract audio waveforms from the same telescopic video sources. In this paper, we demonstrate and compare both readout techniques for several aerospace test scenarios to better show where each has advantages.

  13. Acoustic Liners for Turbine Engines

    Science.gov (United States)

    Jones, Michael G (Inventor); Grady, Joseph E (Inventor); Kiser, James D. (Inventor); Miller, Christopher (Inventor); Heidmann, James D. (Inventor)

    2016-01-01

    An improved acoustic liner for turbine engines is disclosed. The acoustic liner may include a straight cell section including a plurality of cells with straight chambers. The acoustic liner may also include a bent cell section including one or more cells that are bent to extend chamber length without increasing the overall height of the acoustic liner by the entire chamber length. In some cases, holes are placed between cell chambers in addition to bending the cells, or instead of bending the cells.

  14. Densitometry By Acoustic Levitation

    Science.gov (United States)

    Trinh, Eugene H.

    1989-01-01

    "Static" and "dynamic" methods developed for measuring mass density of acoustically levitated solid particle or liquid drop. "Static" method, unknown density of sample found by comparison with another sample of known density. "Dynamic" method practiced with or without gravitational field. Advantages over conventional density-measuring techniques: sample does not have to make contact with container or other solid surface, size and shape of samples do not affect measurement significantly, sound field does not have to be know in detail, and sample can be smaller than microliter. Detailed knowledge of acoustic field not necessary.

  15. Acoustic integrated extinction

    OpenAIRE

    Norris, Andrew N.

    2015-01-01

    The integrated extinction (IE) is defined as the integral of the scattering cross section as a function of wavelength. Sohl et al. (2007 J. Acoust. Soc. Am. 122, 3206–3210. (doi:10.1121/1.2801546)) derived an IE expression for acoustic scattering that is causal, i.e. the scattered wavefront in the forward direction arrives later than the incident plane wave in the background medium. The IE formula was based on electromagnetic results, for which scattering is causal by default. Here, we der...

  16. Acoustic phenomena during boiling

    International Nuclear Information System (INIS)

    Dorofeev, B.M.

    1985-01-01

    Applied and theoretical significance of investigation into acoustic phenomena on boiling is discussed. Effect of spatial and time conditions on pressure vapour bubble has been elucidated. Collective effects were considered: acoustic interaction of bubbles, noise formation ion developed boiling, resonance and hydrodynamic autooscillations. Different methods for predicting heat transfer crisis using changes of accompanying noise characteristics were analysed. Principle peculiarities of generation mechanism of thermoacoustic autooscillations were analysed as well: formation of standing waves; change of two-phase medium contraction in a channel; relation of alternating pressure with boiling process as well as with instantaneous and local temperatures of heat transfer surface and liquid in a boundary layer

  17. Shallow Water Acoustics Studies

    Science.gov (United States)

    2017-11-19

    LE O CEAN RAPHIC I TITUTI Appli d Oc:ean Physics and E11gi1i,ering Depar1111,11t vember 9, 2017 Dr. Robert Headrick ffice of Naval Resear h, ode...UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT Applied Ocean Physics and Engineering Department...2015). [3] J.F. Lynch and A.E. Newhall, "Shallow water acoustics", book chapter in "Practical Underwater Acoustics," L. Bjorno, T. Neighbors, and D

  18. Acoustic emission intrusion detector

    International Nuclear Information System (INIS)

    Carver, D.W.; Whittaker, J.W.

    1980-01-01

    An intrusion detector is provided for detecting a forcible entry into a secured structure while minimizing false alarms. The detector uses a piezoelectric crystal transducer to sense acoustic emissions. The transducer output is amplified by a selectable gain amplifier to control the sensitivity. The rectified output of the amplifier is applied to a Schmitt trigger circuit having a preselected threshold level to provide amplitude discrimination. Timing circuitry is provided which is activated by successive pulses from the Schmitt trigger which lie within a selected time frame for frequency discrimination. Detected signals having proper amplitude and frequency trigger an alarm within the first complete cycle time of a detected acoustical disturbance signal

  19. Acoustic emission intrusion detector

    International Nuclear Information System (INIS)

    Carver, D.W.

    1978-01-01

    In order to improve the security of handling special nuclear materials at the Oak Ridge Y-12 Plant, a sensitive acoustic emission detector has been developed that will detect forcible entry through block or tile walls, concrete floors, or concrete/steel vault walls. A small, low-powered processor was designed to convert the output from a sensitive, crystal-type acoustic transducer to an alarm relay signal for use with a supervised alarm loop. The unit may be used to detect forcible entry through concrete, steel, block, tile, and/or glass

  20. Room Acoustical Fields

    CERN Document Server

    Mechel, Fridolin

    2013-01-01

    This book presents the theory of room acoustical fields and revises the Mirror Source Methods for practical computational use, emphasizing the wave character of acoustical fields.  The presented higher methods include the concepts of “Mirror Point Sources” and “Corner sources which allow for an excellent approximation of complex room geometries and even equipped rooms. In contrast to classical description, this book extends the theory of sound fields describing them by their complex sound pressure and the particle velocity. This approach enables accurate descriptions of interference and absorption phenomena.

  1. Acoustically Induced Vibration of Structures: Reverberant Vs. Direct Acoustic Testing

    Science.gov (United States)

    Kolaini, Ali R.; O'Connell, Michael R.; Tsoi, Wan B.

    2009-01-01

    Large reverberant chambers have been used for several decades in the aerospace industry to test larger structures such as solar arrays and reflectors to qualify and to detect faults in the design and fabrication of spacecraft and satellites. In the past decade some companies have begun using direct near field acoustic testing, employing speakers, for qualifying larger structures. A limited test data set obtained from recent acoustic tests of the same hardware exposed to both direct and reverberant acoustic field testing has indicated some differences in the resulting structural responses. In reverberant acoustic testing, higher vibration responses were observed at lower frequencies when compared with the direct acoustic testing. In the case of direct near field acoustic testing higher vibration responses appeared to occur at higher frequencies as well. In reverberant chamber testing and direct acoustic testing, standing acoustic modes of the reverberant chamber or the speakers and spacecraft parallel surfaces can strongly couple with the fundamental structural modes of the test hardware. In this paper data from recent acoustic testing of flight hardware, that yielded evidence of acoustic standing wave coupling with structural responses, are discussed in some detail. Convincing evidence of the acoustic standing wave/structural coupling phenomenon will be discussed, citing observations from acoustic testing of a simple aluminum plate. The implications of such acoustic coupling to testing of sensitive flight hardware will be discussed. The results discussed in this paper reveal issues with over or under testing of flight hardware that could pose unanticipated structural and flight qualification issues. Therefore, it is of paramount importance to understand the structural modal coupling with standing acoustic waves that has been observed in both methods of acoustic testing. This study will assist the community to choose an appropriate testing method and test setup in

  2. Variable-Position Acoustic Levitation

    Science.gov (United States)

    Barmatz, M. B.; Stoneburner, J. D.; Jacobi, N.; Wang, T. G.

    1983-01-01

    Method of acoustic levitation supports objects at positions other than acoustic nodes. Acoustic force is varied so it balances gravitational (or other) force, thereby maintaining object at any position within equilibrium range. Levitation method applicable to containerless processing. Such objects as table-tennis balls, hollow plastic spheres, and balsa-wood spheres levitated in laboratory by new method.

  3. Theoretical analysis of leaky surface acoustic waves of point-focused acoustic lens and some experiments

    International Nuclear Information System (INIS)

    Ishikawa, Isao; Suzuki, Yoshiaki; Ogura, Yukio; Katakura, Kageyoshi

    1997-01-01

    When a point-focused acoustic lens in the scanning acoustic microscope (SAM) is faced to test specimen and defocused to some extent, two effective echoes can be obtained. One is the echo of longitudinal wave, which is normally incident upon the specimen of an on-axis beam in the central region of the lens and is reflected normal to the lens surface, hence detected by the transducer. The other is of leaky surface acoustic waves(LSAW), which are mode converted front a narrow beam of off-axis longitudinal wave, then propagate across the surface of the specimen and reradiate at angles normal to the lens surface, thus detected by the transducer. These two echoes are either interfered or separated with each other depending ell the defocused distance. It turned out theoretically that the LSAW have a narrow focal spot in the central region of the point-focused acoustic lens, whose size is approximately 40% of the LSAW wavelength. On top of that, a wavelength of LSAW is about 50% short as that of longitudinal wave. So, It is expected that high resolution images can be obtained provided LSAW are used in the scanning acoustic microscope.

  4. Beam aperture modifier design with acoustic metasurfaces

    Science.gov (United States)

    Tang, Weipeng; Ren, Chunyu

    2017-10-01

    In this paper, we present a design concept of acoustic beam aperture modifier using two metasurface-based planar lenses. By appropriately designing the phase gradient profile along the metasurface, we obtain a class of acoustic convex lenses and concave lenses, which can focus the incoming plane waves and collimate the converging waves, respectively. On the basis of the high converging and diverging capability of these lenses, two kinds of lens combination scheme, including the convex-concave type and convex-convex type, are proposed to tune up the incoming beam aperture as needed. To be specific, the aperture of the acoustic beam can be shrunk or expanded through adjusting the phase gradient of the pair of lenses and the spacing between them. These lenses and the corresponding aperture modifiers are constructed by the stacking ultrathin labyrinthine structures, which are obtained by the geometry optimization procedure and exhibit high transmission coefficient and a full range of phase shift. The simulation results demonstrate the effectiveness of our proposed beam aperture modifiers. Due to the flexibility in aperture controlling and the simplicity in fabrication, the proposed modifiers have promising potential in applications, such as acoustic imaging, nondestructive evaluation, and communication.

  5. Acoustic reflection log in transversely isotropic formations

    Science.gov (United States)

    Ronquillo Jarillo, G.; Markova, I.; Markov, M.

    2018-01-01

    We have calculated the waveforms of sonic reflection logging for a fluid-filled borehole located in a transversely isotropic rock. Calculations have been performed for an acoustic impulse source with the characteristic frequency of tens of kilohertz that is considerably less than the frequencies of acoustic borehole imaging tools. It is assumed that the borehole axis coincides with the axis of symmetry of the transversely isotropic rock. It was shown that the reflected wave was excited most efficiently at resonant frequencies. These frequencies are close to the frequencies of oscillations of a fluid column located in an absolutely rigid hollow cylinder. We have shown that the acoustic reverberation is controlled by the acoustic impedance of the rock Z = Vphρs for fixed parameters of the borehole fluid, where Vph is the velocity of horizontally propagating P-wave; ρs is the rock density. The methods of waveform processing to determine the parameters characterizing the reflected wave have been discussed.

  6. Fundamentals of Acoustics. Psychoacoustics and Hearing. Acoustical Measurements

    Science.gov (United States)

    Begault, Durand R.; Ahumada, Al (Technical Monitor)

    1997-01-01

    These are 3 chapters that will appear in a book titled "Building Acoustical Design", edited by Charles Salter. They are designed to introduce the reader to fundamental concepts of acoustics, particularly as they relate to the built environment. "Fundamentals of Acoustics" reviews basic concepts of sound waveform frequency, pressure, and phase. "Psychoacoustics and Hearing" discusses the human interpretation sound pressure as loudness, particularly as a function of frequency. "Acoustic Measurements" gives a simple overview of the time and frequency weightings for sound pressure measurements that are used in acoustical work.

  7. Collimator with compensated filtration: clinical adaptation for recommendation 4f of the EU about the radiation protection in oral dental radiology; Colimador con filtracion compensada: adaptacion clinica para alcanzar la recomendacion 4F de la Union Europea sobre proteccion radiologica al paciente en radiologia odontologica

    Energy Technology Data Exchange (ETDEWEB)

    Alcaraz, M; Garcia-Vera, C; Bravo, C La; Morant, J J; Armedo, D Y; Canteras, M

    2006-07-01

    Recent recommendations by the European Union (2004) for performing lateral cranial cephalometry (LCC) state that collimation should be maximized so that only those tissues necessary are irradiated when performing clinical diagnoses, although the fact that many manufacturers do not incorporate these elements in their equipment design has been recognised (recommendations 4f). Aim: the manufacture and utilization of a collimator with a pre-patient compensating filter for LLC which may be used in most extraoraldental radiology units, as well as determining the reduction in the dose of radiation absorbed by more sensitive tissues exposed to said clinical exploration. Making use of mannequins, phantom and craniums, we constructed a collimator with a compensating filter and established the necessary technical, dosimetric and quality specifications for its clinical use. Subsequently, we studied 16 patients referred for cephalometric study, determining the radiation dose (TLDs) in both the patients (crystalline lens, frontal lobe, parotid/submaxillary/thyroid glands and brain) and in the radiographic film, as well as in different parts of the collimator/filter. Al presented we are aiming for its clinical use by carrying out LCC in another 16 patients referred of orthodontic treatment but with the pre-a patient introduction of the tested collimator with the compensating filter as a substitute for the usual technique. The collimation reduced the field or radiation by some 40% and with that, so too the radiated tissues. The compensating filter reduced the dose in tissues by some 34.2. Our collimator has allowed the radiological image to be obtained with only one third the usual radiation dose. The dose reaching the film shies only between 17% less than in the usual technique and didn't alter its diagnostic capacity. A reduction of 61,6% of the dose administered to the patient is achieved by incorporating the collimator and filter to most radiological equipment without the need

  8. Collimator with compensated filtration: clinical adaptation for recommendation 4f of the EU about the radiation protection in oral dental radiology; Colimador con filtracion compensada: adaptacion clinica para alcanzar la recomendacion 4F de la Union Europea sobre proteccion radiologica al paciente en radiologia odontologica

    Energy Technology Data Exchange (ETDEWEB)

    Alcaraz, M.; Garcia-Vera, C.; Bravo, C. La; Morant, J. J.; Armedo, D. Y.; Canteras, M.

    2006-07-01

    Recent recommendations by the European Union (2004) for performing lateral cranial cephalometry (LCC) state that collimation should be maximized so that only those tissues necessary are irradiated when performing clinical diagnoses, although the fact that many manufacturers do not incorporate these elements in their equipment design has been recognised (recommendations 4f). Aim: the manufacture and utilization of a collimator with a pre-patient compensating filter for LLC which may be used in most extraoraldental radiology units, as well as determining the reduction in the dose of radiation absorbed by more sensitive tissues exposed to said clinical exploration. Making use of mannequins, phantom and craniums, we constructed a collimator with a compensating filter and established the necessary technical, dosimetric and quality specifications for its clinical use. Subsequently, we studied 16 patients referred for cephalometric study, determining the radiation dose (TLDs) in both the patients (crystalline lens, frontal lobe, parotid/submaxillary/thyroid glands and brain) and in the radiographic film, as well as in different parts of the collimator/filter. Al presented we are aiming for its clinical use by carrying out LCC in another 16 patients referred of orthodontic treatment but with the pre-a patient introduction of the tested collimator with the compensating filter as a substitute for the usual technique. The collimation reduced the field or radiation by some 40% and with that, so too the radiated tissues. The compensating filter reduced the dose in tissues by some 34.2. Our collimator has allowed the radiological image to be obtained with only one third the usual radiation dose. The dose reaching the film shies only between 17% less than in the usual technique and didn't alter its diagnostic capacity. A reduction of 61,6% of the dose administered to the patient is achieved by incorporating the collimator and filter to most radiological equipment without the

  9. Comparison of LiVPO4F to Li4Ti5O12 as anode materials for lithium-ion batteries.

    Science.gov (United States)

    Ma, Rui; Shao, Lianyi; Wu, Kaiqiang; Shui, Miao; Wang, Dongjie; Pan, Jianguo; Long, Nengbing; Ren, Yuanlong; Shu, Jie

    2013-09-11

    In this paper, we reported on a comparison of LiVPO4F to Li4Ti5O12 as anode materials for lithium-ion batteries. Combined with powder X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, galvanostatic discharge/charge tests and in situ X-ray diffraction technologies, we explore and compare the insertion/extraction mechanisms of LiVPO4F based on the V3+/V2+/V+ redox couples and Li4Ti5O12 based on the Ti4+/Ti3+ redox couple cycled in 1.0-3.0 V and 0.0-3.0 V. The electrochemical results indicate that both LiVPO4F and Li4Ti5O12 are solid electrolyte interphase free materials in 1.0-3.0 V. The insertion/extraction mechanisms of LiVPO4F and Li4Ti5O12 are similar with each other in 1.0-3.0 V as proved by in situ X-ray diffraction. It also demonstrates that both samples possess stable structure in 0.0-3.0 V. Additionally, the electrochemical performance tests of LiVPO4F and Li4Ti5O12 indicate that both samples cycled in 0.0-3.0 V exhibit much higher capacities than those cycled in 1.0-3.0 V but display worse cycle performance. The rate performance of Li4Ti5O12 far exceeds that of LiVPO4F in the same electrochemical potential window. In particular, the capacity retention of Li4Ti5O12 cycled in 1.0-3.0 V is as high as 98.2% after 20 cycles. By contrast, Li4Ti5O12 is expected to be a candidate anode material considering its high working potential, structural zero-strain property, and excellent cycle stability and rate performance.

  10. Stark components of lower-lying manifolds and emission cross-sections of intermanifold and inter-stark transitions of Nd3+(4f3) in polycrystalline ceramic garnet Y3Al5O12

    International Nuclear Information System (INIS)

    Sardar, Dhiraj K.; Yow, Raylon M.; Gruber, John B.; Allik, Toomas H.; Zandi, Bahram

    2006-01-01

    Stark energy levels of the 4 F 3/2 , 4 I 9/2 , and 4 I 11/2 manifolds have been characterized using the room temperature fluorescence spectra for the 4 F 3/2 → 4 I 9/2 and 4 F 3/2 → 4 I 11/2 transitions of Nd 3+ (4f 3 ) in polycrystalline ceramic garnet Y 3 Al 5 O 12 (YAG). The emission cross-sections of the intermanifold transitions, 4 F 3/2 → 4 I 9/2 and 4 F 3/2 → 4 I 11/2 , as well as the principal inter-Stark transitions, R 1 →Z 5 (945.3 nm) and R 1 →Y 2 (1063.5 nm), have also been determined. These results are finally compared with those of Nd 3+ :YAG single crystal

  11. Acoustic and seismic imaging of the Adra Fault (NE Alboran Sea: in search of the source of the 1910 Adra earthquake

    Directory of Open Access Journals (Sweden)

    E. Gràcia

    2012-11-01

    Full Text Available Recently acquired swath-bathymetry data and high-resolution seismic reflection profiles offshore Adra (Almería, Spain reveal the surficial expression of a NW–SE trending 20 km-long fault, which we termed the Adra Fault. Seismic imaging across the structure depicts a sub-vertical fault reaching the seafloor surface and slightly dipping to the NE showing an along-axis structural variability. Our new data suggest normal displacement of the uppermost units with probably a lateral component. Radiocarbon dating of a gravity core located in the area indicates that seafloor sediments are of Holocene age, suggesting present-day tectonic activity. The NE Alboran Sea area is characterized by significant low-magnitude earthquakes and by historical records of moderate magnitude, such as the Mw = 6.1 1910 Adra Earthquake. The location, dimension and kinematics of the Adra Fault agree with the fault solution and magnitude of the 1910 Adra Earthquake, whose moment tensor analysis indicates normal-dextral motion. The fault seismic parameters indicate that the Adra Fault is a potential source of large magnitude (Mw ≤ 6.5 earthquakes, which represents an unreported seismic hazard for the neighbouring coastal areas.

  12. Acoustic levitator for containerless measurements on low temperature liquids

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-01-01

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

  13. Elastic versus acoustic inversion for marine surveys

    Science.gov (United States)

    Mora, Peter; Wu, Zedong

    2018-04-01

    Full Wavefield Inversion (FWI) is a powerful and elegant approach for seismic imaging that is on the way to becoming the method of choice when processing exploration or global seismic data. In the case of processing marine survey data, one may be tempted to assume acoustic FWI is sufficient given that only pressure waves exist in the water layer. In this paper, we pose the question as to whether or not in theory - at least for a hard water bottom case - it should be possible to resolve the shear modulus or S-wave velocity in a marine setting using large offset data. We therefore conduct numerical experiments with idealized marine data calculated with the elastic wave equation. We study two cases, FWI of data due to a diffractor model, and FWI of data due to a fault model. We find that at least in idealized situation, elastic FWI of hard waterbottom data is capable of resolving between the two Lamé parameters λ and μ. Another numerical experiment with a soft waterbottom layer gives the same result. In contrast, acoustic FWI of the synthetic elastic data results in a single image of the first Lamé parameter λ which contains severe artefacts for diffraction data and noticable artefacts for layer reflection data. Based on these results, it would appear that at least, inversions of large offset marine data should be fully elastic rather than acoustic unless it has been demonstrated that for the specific case in question (offsets, model and water depth, practical issues such as soft sediment attenuation of shear waves or computational time), that an acoustic only inversion provides a reasonably good quality of image comparable to that of an elastic inversion. Further research with real data is required to determine the degree to which practical issues such as shear wave attenuation in soft sediments may affect this result.

  14. Validation and application of Acoustic Mapping Velocimetry

    Science.gov (United States)

    Baranya, Sandor; Muste, Marian

    2016-04-01

    The goal of this paper is to introduce a novel methodology to estimate bedload transport in rivers based on an improved bedform tracking procedure. The measurement technique combines components and processing protocols from two contemporary nonintrusive instruments: acoustic and image-based. The bedform mapping is conducted with acoustic surveys while the estimation of the velocity of the bedforms is obtained with processing techniques pertaining to image-based velocimetry. The technique is therefore called Acoustic Mapping Velocimetry (AMV). The implementation of this technique produces a whole-field velocity map associated with the multi-directional bedform movement. Based on the calculated two-dimensional bedform migration velocity field, the bedload transport estimation is done using the Exner equation. A proof-of-concept experiment was performed to validate the AMV based bedload estimation in a laboratory flume at IIHR-Hydroscience & Engineering (IIHR). The bedform migration was analysed at three different flow discharges. Repeated bed geometry mapping, using a multiple transducer array (MTA), provided acoustic maps, which were post-processed with a particle image velocimetry (PIV) method. Bedload transport rates were calculated along longitudinal sections using the streamwise components of the bedform velocity vectors and the measured bedform heights. The bulk transport rates were compared with the results from concurrent direct physical samplings and acceptable agreement was found. As a first field implementation of the AMV an attempt was made to estimate bedload transport for a section of the Ohio river in the United States, where bed geometry maps, resulted by repeated multibeam echo sounder (MBES) surveys, served as input data. Cross-sectional distributions of bedload transport rates from the AMV based method were compared with the ones obtained from another non-intrusive technique (due to the lack of direct samplings), ISSDOTv2, developed by the US Army

  15. Elastic versus acoustic inversion for marine surveys

    KAUST Repository

    Mora, Peter

    2018-04-24

    Full Wavefield Inversion (FWI) is a powerful and elegant approach for seismic imaging that is on the way to becoming the method of choice when processing exploration or global seismic data. In the case of processing marine survey data, one may be tempted to assume acoustic FWI is sufficient given that only pressure waves exist in the water layer. In this paper, we pose the question as to whether or not in theory – at least for a hard water bottom case – it should be possible to resolve the shear modulus or S-wave velocity in a marine setting using large offset data. We therefore conduct numerical experiments with idealized marine data calculated with the elastic wave equation. We study two cases, FWI of data due to a diffractor model, and FWI of data due to a fault model. We find that at least in idealized situation, elastic FWI of hard waterbottom data is capable of resolving between the two Lamé parameters λ and μ. Another numerical experiment with a soft waterbottom layer gives the same result. In contrast, acoustic FWI of the synthetic elastic data results in a single image of the first Lamé parameter λ which contains severe artefacts for diffraction data and noticable artefacts for layer reflection data. Based on these results, it would appear that at least, inversions of large offset marine data should be fully elastic rather than acoustic unless it has been demonstrated that for the specific case in question (offsets, model and water depth, practical issues such as soft sediment attenuation of shear waves or computational time), that an acoustic only inversion provides a reasonably good quality of image comparable to that of an elastic inversion. Further research with real data is required to determine the degree to which practical issues such as shear wave attenuation in soft sediments may affect this result.

  16. Improved acoustic levitation apparatus

    Science.gov (United States)

    Berge, L. H.; Johnson, J. L.; Oran, W. A.; Reiss, D. A.

    1980-01-01

    Concave driver and reflector enhance and shape levitation forces in acoustic resonance system. Single-mode standing-wave pattern is focused by ring element situated between driver and reflector. Concave surfaces increase levitating forces up to factor of 6 as opposed to conventional flat surfaces, making it possible to suspend heavier objects.

  17. Acoustic cavitation studies

    Science.gov (United States)

    Crum, L. A.

    1981-09-01

    The primary thrust of this study was toward a more complete understanding of general aspects of acoustic cavitation. The effect of long-chain polymer additives on the cavitation threshold was investigated to determine if they reduced the acoustic cavitation threshold in a similar manner to the observed reduction in the cavitation index in hydrodynamic cavitation. Measurements were made of the acoustic cavitation threshold as a function of polymer concentration for additives such as guar gum and polyethelene oxide. The measurements were also made as a function of dissolved gas concentration, surface tension and viscosity. It was determined that there was a significant increase in the acoustic cavitation threshold for increased concentrations of the polymer additives (measurable effects could be obtained for concentrations as low as a few parts per million). One would normally expect that an additive that reduces surface tension to decrease the pressure required to cause a cavity to grow and thus these additives, at first thought, should reduce the threshold. However, even in the hydrodynamic case, the threshold was increased. In both of the hydrodynamic cases considered, the explanation for the increased threshold was given in terms of changed fluid dynamics rather than changed physical properties of the fluid.

  18. Acoustic Neuroma Educational Video

    Medline Plus

    Full Text Available ... Cumming, GA 30041 770-205-8211 info@ANAUSA.org The world’s #1 acoustic neuroma resource Click to ... Cumming, GA 30041 770-205-8211 info@ANAUSA.org About ANA Mission, Vision & Values Leadership & Staff Annual ...

  19. Evoked acoustic emission

    DEFF Research Database (Denmark)

    Elberling, C; Parbo, J; Johnsen, N J

    1985-01-01

    Stimulated acoustic emissions were recorded in response to tonal stimuli at 60 dB p.e. SPL in a small group of normal-hearing adults. Power spectral analysis reveals that the evoked activity from each ear contains energy in preferential frequency bands and the change of stimulus frequency has only...

  20. Portable acoustic myography

    DEFF Research Database (Denmark)

    Harrison, Adrian Paul; Danneskiold-Samsøe, Bente; Bartels, Else Marie

    2013-01-01

    Muscle sound gives a local picture of muscles involved in a particular movement and is independent of electrical signals between nerve and muscle. Sound recording (acoustic myography) is a well-known noninvasive technique that has suffered from not being easily applicable, as well as not being able...

  1. Surface Acoustic Wave Devices

    DEFF Research Database (Denmark)

    Dühring, Maria Bayard

    The work of this project is concerned with the simulation of surface acoustic waves (SAW) and topology optimization of SAW devices. SAWs are elastic vibrations that propagate along a material surface and are extensively used in electromechanical filters and resonators in telecommunication. A new...

  2. Acoustic force spectroscopy

    NARCIS (Netherlands)

    Sitters, G.; Kamsma, D.; Thalhammer, G.; Ritsch-Marte, M.; Peterman, E.J.G.; Wuite, G.J.L.

    2015-01-01

    Force spectroscopy has become an indispensable tool to unravel the structural and mechanochemical properties of biomolecules. Here we extend the force spectroscopy toolbox with an acoustic manipulation device that can exert forces from subpiconewtons to hundreds of piconewtons on thousands of

  3. Underwater Acoustic Networking Techniques

    CERN Document Server

    Otnes, Roald; Casari, Paolo; Goetz, Michael; Husøy, Thor; Nissen, Ivor; Rimstad, Knut; van Walree, Paul; Zorzi, Michele

    2012-01-01

    This literature study presents an overview of underwater acoustic networking. It provides a background and describes the state of the art of all networking facets that are relevant for underwater applications. This report serves both as an introduction to the subject and as a summary of existing protocols, providing support and inspiration for the development of network architectures.

  4. Acoustic Surface Cavitation

    NARCIS (Netherlands)

    Zijlstra, A.G.

    2011-01-01

    Merely the presence of compressible entities, known as bubbles, greatly enriches the physical phenomena encountered when introducing ultrasound in a liquid. Mediated by the response of these bubbles, the otherwise diffuse and relatively low energy density of the acoustic field can induce strong,

  5. Select Internet Resources on Acoustics

    Directory of Open Access Journals (Sweden)

    Angela R. Davis

    2016-12-01

    Full Text Available Merriam-Webster (2016 defines acoustics as, “a science that deals with the production, control, transmission, reception, and effects of sounds.” According to Rossing (2014, the study of acoustics began in ancient Greece with Pythagoras’ study of vibrating strings on musical instruments. Since those early beginnings, famous scientists including Rayleigh, Alexander Graham Bell, and Thomas Edison, have helped expand the field of acoustics to include architectural, physical, engineering, structural, underwater, physiological and psychological, musical acoustics, and speech. Acoustics is a highly interdisciplinary field and researchers may need resources from physics, medicine, and engineering to understand all aspects of their research.

  6. Electric field effect on the emission rate of H4F and H4S hole traps in InP

    International Nuclear Information System (INIS)

    Darwich, R.; Alek, B.

    2010-01-01

    The electric field effect on the emission rate enhancement of the H4 F and H4 S hole trap in highly Zn-doped InP has been examined using the deep level transient spectroscopy (DLTS) and double correlation DLTS (DDLTS). The DLTS and DDLTS results have been found to be in good agreement for low and intermediate electric fields, but they disagree for large field effect. Comparing our emission data with the theory, we have found that H4 F obeys the quantum model of phonon-assisted tunneling while H4 S follows the Poole-Frenkel model employing a three-dimensional screening coulombic potential. Our results show that the H4 S defect can be attributed to a charged (V p - Zn) complex. (author)

  7. s-wave threshold in electron attachment - Results in 2-C4F6 and CFCl3 at ultra-low electron energies

    Science.gov (United States)

    Chutjian, A.; Alajajian, S. H.; Ajello, J. M.; Orient, O. J.

    1984-01-01

    Electron attachment lineshapes and cross sections are reported for the processes 2-C4F6(-)/2-C4F6 and Cl(-)/CFCl3 at electron energies of 0-120 and 0-140 meV, and at resolutions of 6 and 7 meV (FWHM), respectively. As in previous measurements in CCl4 and SF6, the results show resolution-limited narrow structure in the cross section at electron energies below 15 meV. This structure arises from the divergence of the s-wave cross section in the limit of zero electron energy. Comparisons are given with swarm-measured results, and with collisional ionization (high-Rydberg attachment) data in this energy range.

  8. Inspection of copper canister for spent nuclear fuel by means of ultrasound. Copper characterization, FSW monitoring with acoustic emission and ultrasonic imaging

    International Nuclear Information System (INIS)

    Stepinski, Tadeusz

    2009-08-01

    This report contains the research results concerning advanced ultrasound for the inspection of copper canisters for spent nuclear fuel obtained at Signals and Systems, Uppsala University in 2008. The first part of the report is concerned with aspects related to ultrasonic attenuation of copper material used for canisters. We present results of attenuation measurement performed for a number of samples taken from a real canister; two from the lid and four from different parts of canister wall. Ultrasonic attenuation of the material originating from canister lid is relatively low (less that 50 dB/m) and essentially frequency independent in the frequency range up to 5 MHz. However, for the material originating from the extruded canister part considerable variations of the attenuation are observed, which can reach even 200 dB/m at 3.5 MHz. In the second part of the report we present further development of the concept of the friction stir welding process monitoring by means of multiple sensors formed into a uniform circular array (UCA). After a brief introduction into modeling Lamb waves and UCA we focus on array processing techniques that enable estimating direction of arrival of multimodal Lamb waves. We consider two new techniques, the Capon beamformer and the broadband multiple signal classification technique (MUSIC). We present simulation results illustrating their performance. In the final part we present the phase shift migration algorithm for ultrasonic imaging of layered media using synthetic aperture concept. We start from explaining theory of the phase migration concept, which is followed by the results of experiments performed on copper blocks with drilled holes. We show that the proposed algorithm performs well for immersion inspection of metal objects and yields both improved spatial resolution and suppressed grain noise

  9. Inspection of copper canister for spent nuclear fuel by means of ultrasound. Copper characterization, FSW monitoring with acoustic emission and ultrasonic imaging

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-08-15

    This report contains the research results concerning advanced ultrasound for the inspection of copper canisters for spent nuclear fuel obtained at Signals and Systems, Uppsala University in 2008. The first part of the report is concerned with aspects related to ultrasonic attenuation of copper material used for canisters. We present results of attenuation measurement performed for a number of samples taken from a real canister; two from the lid and four from different parts of canister wall. Ultrasonic attenuation of the material originating from canister lid is relatively low (less that 50 dB/m) and essentially frequency independent in the frequency range up to 5 MHz. However, for the material originating from the extruded canister part considerable variations of the attenuation are observed, which can reach even 200 dB/m at 3.5 MHz. In the second part of the report we present further development of the concept of the friction stir welding process monitoring by means of multiple sensors formed into a uniform circular array (UCA). After a brief introduction into modeling Lamb waves and UCA we focus on array processing techniques that enable estimating direction of arrival of multimodal Lamb waves. We consider two new techniques, the Capon beamformer and the broadband multiple signal classification technique (MUSIC). We present simulation results illustrating their performance. In the final part we present the phase shift migration algorithm for ultrasonic imaging of layered media using synthetic aperture concept. We start from explaining theory of the phase migration concept, which is followed by the results of experiments performed on copper blocks with drilled holes. We show that the proposed algorithm performs well for immersion inspection of metal objects and yields both improved spatial resolution and suppressed grain noise

  10. Detergent-induced stabilization and improved 3D map of the human heteromeric amino acid transporter 4F2hc-LAT2.

    Science.gov (United States)

    Meury, Marcel; Costa, Meritxell; Harder, Daniel; Stauffer, Mirko; Jeckelmann, Jean-Marc; Brühlmann, Béla; Rosell, Albert; Ilgü, Hüseyin; Kovar, Karin; Palacín, Manuel; Fotiadis, Dimitrios

    2014-01-01

    Human heteromeric amino acid transporters (HATs) are membrane protein complexes that facilitate the transport of specific amino acids across cell membranes. Loss of function or overexpression of these transporters is implicated in several human diseases such as renal aminoacidurias and cancer. HATs are composed of two subunits, a heavy and a light subunit, that are covalently connected by a disulphide bridge. Light subunits catalyse amino acid transport and consist of twelve transmembrane α-helix domains. Heavy subunits are type II membrane N-glycoproteins with a large extracellular domain and are involved in the trafficking of the complex to the plasma membrane. Structural information on HATs is scarce because of the difficulty in heterologous overexpression. Recently, we had a major breakthrough with the overexpression of a recombinant HAT, 4F2hc-LAT2, in the methylotrophic yeast Pichia pastoris. Microgram amounts of purified protein made possible the reconstruction of the first 3D map of a human HAT by negative-stain transmission electron microscopy. Here we report the important stabilization of purified human 4F2hc-LAT2 using a combination of two detergents, i.e., n-dodecyl-β-D-maltopyranoside and lauryl maltose neopentyl glycol, and cholesteryl hemisuccinate. The superior quality and stability of purified 4F2hc-LAT2 allowed the measurement of substrate binding by scintillation proximity assay. In addition, an improved 3D map of this HAT could be obtained. The detergent-induced stabilization of the purified human 4F2hc-LAT2 complex presented here paves the way towards its crystallization and structure determination at high-resolution, and thus the elucidation of the working mechanism of this important protein complex at the molecular level.

  11. Detergent-induced stabilization and improved 3D map of the human heteromeric amino acid transporter 4F2hc-LAT2.

    Directory of Open Access Journals (Sweden)

    Marcel Meury

    Full Text Available Human heteromeric amino acid transporters (HATs are membrane protein complexes that facilitate the transport of specific amino acids across cell membranes. Loss of function or overexpression of these transporters is implicated in several human diseases such as renal aminoacidurias and cancer. HATs are composed of two subunits, a heavy and a light subunit, that are covalently connected by a disulphide bridge. Light subunits catalyse amino acid transport and consist of twelve transmembrane α-helix domains. Heavy subunits are type II membrane N-glycoproteins with a large extracellular domain and are involved in the trafficking of the complex to the plasma membrane. Structural information on HATs is scarce because of the difficulty in heterologous overexpression. Recently, we had a major breakthrough with the overexpression of a recombinant HAT, 4F2hc-LAT2, in the methylotrophic yeast Pichia pastoris. Microgram amounts of purified protein made possible the reconstruction of the first 3D map of a human HAT by negative-stain transmission electron microscopy. Here we report the important stabilization of purified human 4F2hc-LAT2 using a combination of two detergents, i.e., n-dodecyl-β-D-maltopyranoside and lauryl maltose neopentyl glycol, and cholesteryl hemisuccinate. The superior quality and stability of purified 4F2hc-LAT2 allowed the measurement of substrate binding by scintillation proximity assay. In addition, an improved 3D map of this HAT could be obtained. The detergent-induced stabilization of the purified human 4F2hc-LAT2 complex presented here paves the way towards its crystallization and structure determination at high-resolution, and thus the elucidation of the working mechanism of this important protein complex at the molecular level.

  12. Mild hydrothermal synthesis, crystal structure, thermal behaviour, spectroscopic and magnetic properties of (NH4)0.80Li0.20[Fe(AsO4)F

    International Nuclear Information System (INIS)

    Berrocal, Teresa; Mesa, Jose L.; Larrea, Edurne S.; Bazan, Begona; Pizarro, Jose L.; Lezama, Luis; Rojo, Teofilo; Arriortua, Maria I.

    2011-01-01

    The (NH 4 ) 0.80 Li 0.20 [Fe(AsO 4 )F] compound has been synthesized under mild hydrothermal conditions. The compound crystallize in the orthorhombic Pna2 1 space group, with cell parameters a=13.352(9), b=6.7049(9), c=10.943(2) A and Z=8. The compound belongs to the KTiO(PO 4 ) structure type, with chains alternating FeO 4 F 2 octahedra and AsO 4 tetrahedra, respectively, running along the 'a' and 'b' crystallographic axes. The diffuse reflectance spectrum in the visible region shows the forbidden electronic transitions characteristic of the Fe(III) d 5 -high spin cation in slightly distorted octahedral geometry. The Moessbauer spectrum at room temperature is characteristic of iron (III) cations. The ESR spectra, carried out from room temperature to 200 K, remain isotropic with variation in temperature; the g-value being 1.99(1). Magnetic measurements indicate the predominance of strong antiferromagnetic interactions. - Graphical Abstract: Three-dimensional structure of (NH 4 ) 0.80 Li 0.20 [Fe(AsO 4 )F], a fluoroarsenate containing lithium and ammonium in the structural cavities. Highlights: → (NH 4 ) 0.80 Li 0.20 [Fe(AsO 4 )F] has been synthesized by mild hydrothermal technique. → The compound exhibits a three-dimensional structure. → Moessbauer spectrum indicates the existence of Fe(III) cations. → Visible spectroscopy confirms the hexacoordination of Fe(III). → Magnetic measurements indicate the existence of a global antiferromagnetic ordering.

  13. Novel green-emitting Na2CaPO4F:Eu2+ phosphors for near-ultraviolet white light-emitting diodes

    International Nuclear Information System (INIS)

    Huang, Chien-Hao; Chen, Yen-Chi; Kuo, Te-Wen; Chen, Teng-Ming

    2011-01-01

    In this study, green-emitting Na 2 CaPO 4 F:Eu 2+ phosphors were synthesized by solid-state reactions. The excitation spectra of the phosphors showed a broad hump between 250 and 450 nm; the spectra match well with the near-ultraviolet (NUV) emission spectra of light-emitting diodes (LEDs). The emission spectrum showed an intense broad emission band centered at 506 nm. White LEDs were fabricated by integrating a 390 nm NUV chip comprising blue-emitting BaMgAl 10 O 17 :Eu 2+ , green-emitting Na 2 CaPO 4 F:0.02 Eu 2+ , and red-emitting CaAlSiN 3 :Eu 2+ phosphors into a single package; the white LEDs exhibited white light with a correlated color temperature of 5540 K, a color-rendering index of 90.75, and color coordinates (0.332, 0.365) close to those of ideal white light. - Highlights: → Novel green-emitting Na 2 CaPO 4 F:Eu 2+ phosphors were synthesized by solid-state reactions in this research. → White LEDs were fabricated by integrating a 390 nm NUV chip comprising blue-emitting BaMgAl 10 O 17 :Eu 2+ , green-emitting Na 2 CaPO 4 F:0.02Eu 2+ , and red-emitting CaAlSiN 3 :Eu 2+ phosphors into a single package. → The white LEDs exhibited white light with a correlated color temperature of 5540 K, a color-rendering index of 90.75, and color coordinates (0.332, 0.365) close to those of ideal white light.

  14. X-ray-induced acoustic computed tomography of concrete infrastructure

    Science.gov (United States)

    Tang, Shanshan; Ramseyer, Chris; Samant, Pratik; Xiang, Liangzhong

    2018-02-01

    X-ray-induced Acoustic Computed Tomography (XACT) takes advantage of both X-ray absorption contrast and high ultrasonic resolution in a single imaging modality by making use of the thermoacoustic effect. In XACT, X-ray absorption by defects and other structures in concrete create thermally induced pressure jumps that launch ultrasonic waves, which are then received by acoustic detectors to form images. In this research, XACT imaging was used to non-destructively test and identify defects in concrete. For concrete structures, we conclude that XACT imaging allows multiscale imaging at depths ranging from centimeters to meters, with spatial resolutions from sub-millimeter to centimeters. XACT imaging also holds promise for single-side testing of concrete infrastructure and provides an optimal solution for nondestructive inspection of existing bridges, pavement, nuclear power plants, and other concrete infrastructure.

  15. Inhibition of VEGF-dependent angiogenesis by the anti-CD82 monoclonal antibody 4F9 through regulation of lipid raft microdomains

    International Nuclear Information System (INIS)

    Nomura, Sayaka; Iwata, Satoshi; Hatano, Ryo; Komiya, Eriko; Dang, Nam H.; Iwao, Noriaki; Ohnuma, Kei; Morimoto, Chikao

    2016-01-01

    CD82 (also known as KAI1) belongs to the tetraspanin superfamily of type III transmembrane proteins, and is involved in regulating cell adhesion, migration and proliferation. In contrast to these well-established roles of CD82 in tumor biology, its function in endothelial cell (EC) activity and tumor angiogenesis is yet to be determined. In this study, we show that suppression of CD82 negatively regulates vascular endothelial growth factor (VEGF)-induced angiogenesis. Moreover, we demonstrate that the anti-CD82 mAb 4F9 effectively inhibits phosphorylation of VEGF receptor 2 (VEGFR2), which is the principal mediator of the VEGF-induced angiogenic signaling process in tumor angiogenesis, by regulating the organization of the lipid raft microdomain signaling platform in human EC. Our present work therefore suggests that CD82 on EC is a potential target for anti-angiogenic therapy in VEGFR2-dependent tumor angiogenesis. -- Highlights: •Knockdown of CD82 decreases EC migration, proliferation and angiogenesis. •Anti-CD82 mAb 4F9 inhibits EC migration, proliferation and angiogenesis. •4F9 inhibits VEGFR2 phosphorylation via control of CD82 distribution in lipid rafts.

  16. Synthesis and tunable luminescent properties of Eu-doped Ca2NaSiO4F – Coexistence of the Eu2+ and Eu3+ centers

    Directory of Open Access Journals (Sweden)

    Mubiao Xie

    Full Text Available Novel phosphors Ca2NaSiO4F:Eu were synthesized successfully by the conventional solid-state method in CO atmosphere, and their spectroscopic properties in UV−vis region were investigated. The photoluminescence properties show that Eu3+ ions were partially reduced to Eu2+ in Ca2NaSiO4F. As a result of radiation and re-absorption energy transfer from Eu2+ to Eu3+, both Eu2+ bluish-green emission at around 520 nm and Eu3+ red emission are observed in the emission spectra under the n-UV light excitation. Furthermore, the ratio between Eu2+ and Eu3+ emissions varies with increasing content of overall Eu. Because relative intensity of the red component from Eu3+ became systematically stronger, white light emission can be realized by combining the emission of Eu2+ and Eu3+ in a single host lattice under n-UV light excitation. These results indicate that the Ca2NaSiO4F:Eu phosphors have potential applications as a n-UV convertible phosphor for light-emitting diodes. Keywords: Phosphors, Luminescence, White LED, Optical materials

  17. Core-level XPS studies of Ce and La intermetallic compounds and their implications for the 4f levels of Ce compounds

    International Nuclear Information System (INIS)

    Freiburg, C.; Fuggle, J.C.; Hillebrecht, F.U.; Zolnierek, Z.; Laesser, R.

    1983-01-01

    The 3d core hole X-ray photoelectron spectra (XPS) of approximately 30 intermetallic compounds of La and Ce are reported. Transitions to final states with approximately f 0 , f 1 and f 2 character are observed in some Ce compounds (f 0 and f 1 for La compounds). The results are discussed in terms of the current ideas of the influence of f-counts and f-levels hybridization on core level lineshapes. We cannot find an explanatoin of the observed spectra consisted with the ''promotial model'' where the 4f-count varies and 4f electron was thought to be entirely promoted to the Ce 5d6s valence bands in some compounds. There may be some small charge transfer from the f level, however. In conjunction with ideas on screening processes in XPS the observed lineshapes suggest coupling of the 4f electrons to other states is strongest in those compounds previously thought to have f 0 character. This coupling increases despite a large increase in the Ce-Ce distance when Ce is diluted with Ni or Pd. Thus it cannot be due to direct f-f interaction and must be attributed to coupling with the other valence electrons; possibly those centred on the partner sites. (orig./EZ) [de

  18. Inhibition of VEGF-dependent angiogenesis by the anti-CD82 monoclonal antibody 4F9 through regulation of lipid raft microdomains

    Energy Technology Data Exchange (ETDEWEB)

    Nomura, Sayaka; Iwata, Satoshi; Hatano, Ryo [Division of Clinical Immunology, Advanced Clinical Research Center, The Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo, 108-8639 (Japan); Komiya, Eriko [Department of Therapy Development and Innovation for Immune Disorders and Cancers, Graduate School of Medicine, Juntendo University, 2-1-1, Hongo, Bunkyo-ku, Tokyo, 113-8421 (Japan); Dang, Nam H. [Division of Hematology/Oncology, University of Florida, 1600 SW Archer Road- Box 100278, Room MSB M410A, Gainesville, FL, 32610 (United States); Iwao, Noriaki [Department of Hematology, School of Medicine, Juntendo University, 2-1-1, Hongo, Bunkyo-ku, Tokyo, 113-8421 (Japan); Ohnuma, Kei, E-mail: kohnuma@juntendo.ac.jp [Department of Rheumatology and Allergy, IMSUT Hospital, The Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo, 108-8639 (Japan); Morimoto, Chikao [Division of Clinical Immunology, Advanced Clinical Research Center, The Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo, 108-8639 (Japan); Department of Rheumatology and Allergy, IMSUT Hospital, The Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo, 108-8639 (Japan)

    2016-05-20

    CD82 (also known as KAI1) belongs to the tetraspanin superfamily of type III transmembrane proteins, and is involved in regulating cell adhesion, migration and proliferation. In contrast to these well-established roles of CD82 in tumor biology, its function in endothelial cell (EC) activity and tumor angiogenesis is yet to be determined. In this study, we show that suppression of CD82 negatively regulates vascular endothelial growth factor (VEGF)-induced angiogenesis. Moreover, we demonstrate that the anti-CD82 mAb 4F9 effectively inhibits phosphorylation of VEGF receptor 2 (VEGFR2), which is the principal mediator of the VEGF-induced angiogenic signaling process in tumor angiogenesis, by regulating the organization of the lipid raft microdomain signaling platform in human EC. Our present work therefore suggests that CD82 on EC is a potential target for anti-angiogenic therapy in VEGFR2-dependent tumor angiogenesis. -- Highlights: •Knockdown of CD82 decreases EC migration, proliferation and angiogenesis. •Anti-CD82 mAb 4F9 inhibits EC migration, proliferation and angiogenesis. •4F9 inhibits VEGFR2 phosphorylation via control of CD82 distribution in lipid rafts.

  19. Quasi-static acoustic tweezing thromboelastometry.

    Science.gov (United States)

    Holt, R G; Luo, D; Gruver, N; Khismatullin, D B

    2017-07-01

    Essentials Blood coagulation measurement during contact with an artificial surface leads to unreliable data. Acoustic tweezing thromboelastometry is a novel non-contact method for coagulation monitoring. This method detects differences in the blood coagulation state within 10 min. Coagulation data were obtained using a much smaller sample volume (4 μL) than currently used. Background Thromboelastography is widely used as a tool to assess the coagulation status of critical care patients. It allows observation of changes in material properties of whole blood, beginning with early stages of clot formation and ending with clot lysis. However, the contact activation of the coagulation cascade at surfaces of thromboelastographic systems leads to inherent variability and unreliability in predicting bleeding or thrombosis risks. Objectives To develop acoustic tweezing thromboelastometry as a non-contact method for perioperative assessment of blood coagulation. Methods Acoustic tweezing is used to levitate microliter drops of biopolymer and human blood samples. By quasi-statically changing the acoustic pressure we control the sample drop location and deformation. Sample size, deformation and location are determined by digital imaging at each pressure. Results Simple Newtonian liquid solutions maintain a constant, reversible location vs. deformation curve. In contrast, the location/deformation curves for gelatin, alginate, whole blood and blood plasma uniquely change as the samples solidify. Increasing elasticity causes the sample to deform less, leading to steeper stress/strain curves. By extracting a linear regime slope, we show that whole blood or blood plasma exhibits a unique slope profile as it begins to clot. By exposing blood samples to pro- or antithrombotic agents, the slope profile changes, allowing detection of hyper- or hypocoagulable states. Conclusions We demonstrate that quasi-static acoustic tweezing can yield information about clotting onset, maturation

  20. Acoustic richness modulates the neural networks supporting intelligible speech processing.

    Science.gov (United States)

    Lee, Yune-Sang; Min, Nam Eun; Wingfield, Arthur; Grossman, Murray; Peelle, Jonathan E

    2016-03-01

    The information contained in a sensory signal plays a critical role in determining what neural processes are engaged. Here we used interleaved silent steady-state (ISSS) functional magnetic resonance imaging (fMRI) to explore how human listeners cope with different degrees of acoustic richness during auditory sentence comprehension. Twenty-six healthy young adults underwent scanning while hearing sentences that varied in acoustic richness (high vs. low spectral detail) and syntactic complexity (subject-relative vs. object-relative center-embedded clause structures). We manipulated acoustic richness by presenting the stimuli as unprocessed full-spectrum speech, or noise-vocoded with 24 channels. Importantly, although the vocoded sentences were spectrally impoverished, all sentences were highly intelligible. These manipulations allowed us to test how intelligible speech processing was affected by orthogonal linguistic and acoustic demands. Acoustically rich speech showed stronger activation than acoustically less-detailed speech in a bilateral temporoparietal network with more pronounced activity in the right hemisphere. By contrast, listening to sentences with greater syntactic complexity resulted in increased activation of a left-lateralized network including left posterior lateral temporal cortex, left inferior frontal gyrus, and left dorsolateral prefrontal cortex. Significant interactions between acoustic richness and syntactic complexity occurred in left supramarginal gyrus, right superior temporal gyrus, and right inferior frontal gyrus, indicating that the regions recruited for syntactic challenge differed as a function of acoustic properties of the speech. Our findings suggest that the neural systems involved in speech perception are finely tuned to the type of information available, and that reducing the richness of the acoustic signal dramatically alters the brain's response to spoken language, even when intelligibility is high. Copyright © 2015 Elsevier

  1. Material Property Measurement in Hostile Environments using Laser Acoustics

    International Nuclear Information System (INIS)

    Ken L. Telschow

    2004-01-01

    Acoustic methods are well known and have been used to measure various intrinsic material properties, such as, elastic coefficients, density, crystal axis orientation, microstructural texture, and residual stress. Extrinsic properties, such as, dimensions, motion variables or temperature are also readily determined from acoustic methods. Laser acoustics, employing optical generation and detection of elastic waves, has a unique advantage over other acoustic methods-it is noncontacting, uses the sample surface itself for transduction, requires no couplant or invasive sample surface preparation and can be utilized in any hostile environment allowing optical access to the sample surface. In addition, optical generation and detection probe beams can be focused to the micron scale and/or shaped to alter the transduction process with a degree of control not possible using contact transduction methods. Laser methods are amenable to both continuous wave and pulse-echo measurements and have been used from Hz to 100's of GHz (time scales from sec to psec) and with amplitudes sufficient to fracture materials. This paper shall review recent applications of laser acoustic methods to determining material properties in hostile environments that preclude the use of contacting transduction techniques. Example environments include high temperature (>1000C) sintering and molten metal processing, thin film deposition by plasma techniques, materials moving at high velocity during the fabrication process and nuclear high radiation regions. Recent technological advances in solid-state lasers and telecommunications have greatly aided the development and implementation of laser acoustic methods, particularly at ultra high frequencies. Consequently, laser acoustic material property measurements exhibit high precision and reproducibility today. In addition, optical techniques provide methods of imaging acoustic motion that is both quantitative and rapid. Possible future directions for laser

  2. Atmospheric histories and growth trends of C4F10, C5F12, C6F14, C7F16 and C8F18

    Directory of Open Access Journals (Sweden)

    R. F. Weiss

    2012-05-01

    Full Text Available Atmospheric observations and trends are presented for the high molecular weight perfluorocarbons (PFCs: decafluorobutane (C4F10, dodecafluoropentane (C5F12, tetradecafluorohexane (C6F14, hexadecafluoroheptane (C7F16 and octadecafluorooctane (C8F18. Their atmospheric histories are based on measurements of 36 Northern Hemisphere and 46 Southern Hemisphere archived air samples collected between 1973 to 2011 using the Advanced Global Atmospheric Gases Experiment (AGAGE "Medusa" preconcentration gas chromatography-mass spectrometry systems. A new calibration scale was prepared for each PFC, with estimated accuracies of 6.8% for C4F10, 7.8% for C5F12, 4.0% for C6F14, 6.6% for C7F16 and 7.9% for C8F18. Based on our observations the 2011 globally averaged dry air mole fractions of these heavy PFCs are: 0.17 parts-per-trillion (ppt, i.e., parts per 1012 for C4F10, 0.12 ppt for C5F12, 0.27 ppt for C6F14, 0.12 ppt for C7F16 and 0.09 ppt for C8F18. These atmospheric mole fractions combine to contribute to a global average radiative forcing of 0.35 mW m−2, which is 6% of the total anthropogenic PFC radiative forcing (Montzka and Reimann, 2011; Oram et al., 2012. The growth rates of the heavy perfluorocarbons were largest in the late 1990s peaking at 6.2 parts per quadrillion (ppq, i.e., parts per 1015 per year (yr for C4F10, at 5.0 ppq yr−1 for C5F12 and 16.6 ppq yr−1 for C6F14 and in the early 1990s for C7F16 at 4.7 ppq yr−1 and in the mid 1990s for C8F18 at 4.8 ppq yr−1. The 2011 globally averaged mean atmospheric growth rates of these PFCs are subsequently lower at 2.2 ppq yr−1 for C4F10, 1.4 ppq yr−1 for C5F12, 5.0 ppq yr−1 for C6F14, 3.4 ppq yr−1 for C7F16 and 0.9 ppq yr−1 for C8F18. The more recent slowdown in the growth rates suggests that emissions are declining as compared to the 1980s and 1990s.

  3. Combining electronic structure and many-body theory with large databases: A method for predicting the nature of 4 f states in Ce compounds

    Science.gov (United States)

    Herper, H. C.; Ahmed, T.; Wills, J. M.; Di Marco, I.; Björkman, T.; Iuşan, D.; Balatsky, A. V.; Eriksson, O.

    2017-08-01

    Recent progress in materials informatics has opened up the possibility of a new approach to accessing properties of materials in which one assays the aggregate properties of a large set of materials within the same class in addition to a detailed investigation of each compound in that class. Here we present a large scale investigation of electronic properties and correlated magnetism in Ce-based compounds accompanied by a systematic study of the electronic structure and 4 f -hybridization function of a large body of Ce compounds. We systematically study the electronic structure and 4 f -hybridization function of a large body of Ce compounds with the goal of elucidating the nature of the 4 f states and their interrelation with the measured Kondo energy in these compounds. The hybridization function has been analyzed for more than 350 data sets (being part of the IMS database) of cubic Ce compounds using electronic structure theory that relies on a full-potential approach. We demonstrate that the strength of the hybridization function, evaluated in this way, allows us to draw precise conclusions about the degree of localization of the 4 f states in these compounds. The theoretical results are entirely consistent with all experimental information, relevant to the degree of 4 f localization for all investigated materials. Furthermore, a more detailed analysis of the electronic structure and the hybridization function allows us to make precise statements about Kondo correlations in these systems. The calculated hybridization functions, together with the corresponding density of states, reproduce the expected exponential behavior of the observed Kondo temperatures and prove a consistent trend in real materials. This trend allows us to predict which systems may be correctly identified as Kondo systems. A strong anticorrelation between the size of the hybridization function and the volume of the systems has been observed. The information entropy for this set of systems is

  4. A study on the application of two different acoustic analogies to experimental PIV data

    NARCIS (Netherlands)

    Koschatzky, V.; Westerweel, J.; Boersma, B.J.

    2011-01-01

    The aim of the present study is to compare two different acoustic analogies applied to time-resolved particle image velocimetry (PIV) data for the prediction of the acoustic far-field generated by the flow over a rectangular cavity. We consider the model problem of sound radiating from an open,

  5. Acoustic fMRI noise : Linear time-invariant system model

    NARCIS (Netherlands)

    Sierra, Carlos V. Rizzo; Versluis, Maarten J.; Hoogduin, Johannes M.; Duifhuis, Hendrikus (Diek)

    Functional magnetic resonance imaging (fMRI) enables sites of brain activation to be localized in human subjects. For auditory system studies, however, the acoustic noise generated by the scanner tends to interfere with the assessments of this activation. Understanding and modeling fMRI acoustic

  6. ImagingSIMS

    Energy Technology Data Exchange (ETDEWEB)

    2017-11-06

    ImagingSIMS is an open source application for loading, processing, manipulating and visualizing secondary ion mass spectrometry (SIMS) data. At PNNL, a separate branch has been further developed to incorporate application specific features for dynamic SIMS data sets. These include loading CAMECA IMS-1280, NanoSIMS and modified IMS-4f raw data, creating isotopic ratio images and stitching together images from adjacent interrogation regions. In addition to other modifications of the parent open source version, this version is equipped with a point-by-point image registration tool to assist with streamlining the image fusion process.

  7. Characterization of human breast cancer by scanning acoustic microscopy

    Science.gov (United States)

    Chen, Di; Malyarenko, Eugene; Seviaryn, Fedar; Yuan, Ye; Sherman, Mark; Bandyopadhyay, Sudeshna; Gierach, Gretchen; Greenway, Christopher W.; Maeva, Elena; Strumban, Emil; Duric, Neb; Maev, Roman

    2013-03-01

    Objectives: The purpose of this study was to characterize human breast cancer tissues by the measurement of microacoustic properties. Methods: We investigated eight breast cancer patients using acoustic microscopy. For each patient, seven blocks of tumor tissue were collected from seven different positions around a tumor mass. Frozen sections (10 micrometer, μm) of human breast cancer tissues without staining and fixation were examined in a scanning acoustic microscope with focused transducers at 80 and 200 MHz. Hematoxylin and Eosin (H and E) stained sections from the same frozen breast cancer tissues were imaged by optical microscopy for comparison. Results: The results of acoustic imaging showed that acoustic attenuation and sound speed in cancer cell-rich tissue regions were significantly decreased compared with the surrounding tissue regions, where most components are normal cells/tissues, such as fibroblasts, connective tissue and lymphocytes. Our observation also showed that the ultrasonic properties were influenced by arrangements of cells and tissue patterns. Conclusions: Our data demonstrate that attenuation and sound speed imaging can provide biomechanical information of the tumor and normal tissues. The results also demonstrate the potential of acoustic microscopy as an auxiliary method for operative detection and localization of cancer affected regions.

  8. Education in acoustics in Argentina

    Science.gov (United States)

    Miyara, Federico

    2002-11-01

    Over the last decades, education in acoustics (EA) in Argentina has experienced ups and downs due to economic and political issues interfering with long term projects. Unlike other countries, like Chile, where EA has reached maturity in spite of the acoustical industry having shown little development, Argentina has several well-established manufacturers of acoustic materials and equipment but no specific career with a major in acoustics. At the university level, acoustics is taught as a complementary--often elective--course for careers such as architecture, communication engineering, or music. In spite of this there are several research centers with programs covering environmental and community noise, effects of noise on man, acoustic signal processing, musical acoustics and acoustic emission, and several national and international meetings are held each year in which results are communicated and discussed. Several books on a variety of topics such as sound system, architectural acoustics, and noise control have been published as well. Another chapter in EA is technical and vocational education, ranging between secondary and postsecondary levels, with technical training on sound system operation or design. Over the last years there have been several attempts to implement master degrees in acoustics or audio engineering, with little or no success.

  9. Acoustic energy harvesting based on a planar acoustic metamaterial

    Science.gov (United States)

    Qi, Shuibao; Oudich, Mourad; Li, Yong; Assouar, Badreddine

    2016-06-01

    We theoretically report on an innovative and practical acoustic energy harvester based on a defected acoustic metamaterial (AMM) with piezoelectric material. The idea is to create suitable resonant defects in an AMM to confine the strain energy originating from an acoustic incidence. This scavenged energy is converted into electrical energy by attaching a structured piezoelectric material into the defect area of the AMM. We show an acoustic energy harvester based on a meta-structure capable of producing electrical power from an acoustic pressure. Numerical simulations are provided to analyze and elucidate the principles and the performances of the proposed system. A maximum output voltage of 1.3 V and a power density of 0.54 μW/cm3 are obtained at a frequency of 2257.5 Hz. The proposed concept should have broad applications on energy harvesting as well as on low-frequency sound isolation, since this system acts as both acoustic insulator and energy harvester.

  10. Flat acoustic lens by acoustic grating with curled slits

    KAUST Repository

    Peng, Pai

    2014-10-01

    We design a flat sub-wavelength lens that can focus acoustic wave. We analytically study the transmission through an acoustic grating with curled slits, which can serve as a material with tunable impedance and refractive index for acoustic waves. The effective parameters rely on the geometry of the slits and are independent of frequency. A flat acoustic focusing lens by such acoustic grating with gradient effective refractive index is designed. The focusing effect is clearly observed in simulations and well predicted by the theory. We demonstrate that despite the large impedance mismatch between the acoustic lens and the matrix, the intensity at the focal point is still high due to Fabry-Perot resonance.

  11. An acoustic prion assay

    Directory of Open Access Journals (Sweden)

    Gordon Hayward

    2016-12-01

    Full Text Available An acoustic prion assay has been demonstrated for sheep brain samples. Only five false positives and no false negatives were observed in a test of 45 positive and 45 negative samples. The acoustic prion sensor was constructed using a thickness shear mode quartz resonator coated with a covalently bound recombinant prion protein. The characteristic indicator of a scrapie infected sheep brain sample was an observed shoulder in the frequency decrease in response to a sample.The response of the sensor aligns with a conformational shift in the surface protein and with the propagation mechanism of the disease. This alignment is evident in the response timing and shape, dependence on concentration, cross species behaviour and impact of blood plasma. This alignment is far from sufficient to prove the mechanism of the sensor but it does offer the possibility of a rapid and inexpensive additional tool to explore prion disease. Keywords: Prions, Thickness shear mode quartz sensor

  12. The acoustics of snoring.

    Science.gov (United States)

    Pevernagie, Dirk; Aarts, Ronald M; De Meyer, Micheline

    2010-04-01

    Snoring is a prevalent disorder affecting 20-40% of the general population. The mechanism of snoring is vibration of anatomical structures in the pharyngeal airway. Flutter of the soft palate accounts for the harsh aspect of the snoring sound. Natural or drug-induced sleep is required for its appearance. Snoring is subject to many influences such as body position, sleep stage, route of breathing and the presence or absence of sleep-disordered breathing. Its presentation may be variable within or between nights. While snoring is generally perceived as a social nuisance, rating of its noisiness is subjective and, therefore, inconsistent. Objective assessment of snoring is important to evaluate the effect of treatment interventions. Moreover, snoring carries information relating to the site and degree of obstruction of the upper airway. If evidence for monolevel snoring at the site of the soft palate is provided, the patient may benefit from palatal surgery. These considerations have inspired researchers to scrutinize the acoustic characteristics of snoring events. Similarly to speech, snoring is produced in the vocal tract. Because of this analogy, existing techniques for speech analysis have been applied to evaluate snoring sounds. It appears that the pitch of the snoring sound is in the low-frequency range (noise-like', and has scattered energy content in the higher spectral sub-bands (>500 Hz). To evaluate acoustic properties of snoring, sleep nasendoscopy is often performed. Recent evidence suggests that the acoustic quality of snoring is markedly different in drug-induced sleep as compared with natural sleep. Most often, palatal surgery alters sound characteristics of snoring, but is no cure for this disorder. It is uncertain whether the perceived improvement after palatal surgery, as judged by the bed partner, is due to an altered sound spectrum. Whether some acoustic aspects of snoring, such as changes in pitch, have predictive value for the presence of

  13. Osmotic Acoustic Source

    Science.gov (United States)

    2017-09-25

    Technology Transfer at (401) 832-1511. DISTRIBUTION STATEMENT Approved for Public Release Distribution is unlimited Attorney Docket No...in the enclosure through osmosis. Valves open at a specified time after the liquid injection to free flood between the enclosure and the...the timing of the salt jets and the free-flooding valves enables a repeatable Attorney Docket No. 300070 4 of 14 acoustic pulse at low

  14. Ocean acoustic tomography

    International Nuclear Information System (INIS)

    Cornuelle, Bruce D; Worcester, Peter F; Dzieciuch, Matthew A

    2008-01-01

    Ocean acoustic tomography (OAT) was proposed in 1979 by Walter Munk and Carl Wunsch as an analogue to x-ray computed axial tomography for the oceans. The oceans are opaque to most electromagnetic radiation, but there is a strong acoustic waveguide, and sound can propagate for 10 Mm and more with distinct multiply-refracted ray paths. Transmitting broadband pulses in the ocean leads to a set of impulsive arrivals at the receiver which characterize the impulse response of the sound channel. The peaks observed at the receiver are assumed to represent the arrival of energy traveling along geometric ray paths. These paths can be distinguished by arrival time, and by arrival angle when a vertical array of receivers is available. Changes in ray arrival time can be used to infer changes in ocean structure. Ray travel time measurements have been a mainstay of long-range acoustic measurements, but the strong sensitivity of ray paths to range-dependent sound speed perturbations makes the ray sampling functions uncertain in real cases. In the ray approximation travel times are sensitive to medium changes only along the corresponding eigenrays. Ray theory is an infinite-frequency approximation, and its eikonal equation has nonlinearities not found in the acoustic wave equation. We build on recent seismology results (kernels for body wave arrivals in the earth) to characterize the kernel for converting sound speed change in the ocean to travel time changes using more complete propagation physics. Wave-theoretic finite frequency kernels may show less sensitivity to small-scale sound speed structure.

  15. Acoustic Droplet Vaporization in Biology and Medicine

    Directory of Open Access Journals (Sweden)

    Chung-Yin Lin

    2013-01-01

    Full Text Available This paper reviews the literature regarding the use of acoustic droplet vaporization (ADV in clinical applications of imaging, embolic therapy, and therapeutic delivery. ADV is a physical process in which the pressure waves of ultrasound induce a phase transition that causes superheated liquid nanodroplets to form gas bubbles. The bubbles provide ultrasonic imaging contrast and other functions. ADV of perfluoropentane was used extensively in imaging for preclinical trials in the 1990s, but its use declined rapidly with the advent of other imaging agents. In the last decade, ADV was proposed and explored for embolic occlusion therapy, drug delivery, aberration correction, and high intensity focused ultrasound (HIFU sensitization. Vessel occlusion via ADV has been explored in rodents and dogs and may be approaching clinical use. ADV for drug delivery is still in preclinical stages with initial applications to treat tumors in mice. Other techniques are still in preclinical studies but have potential for clinical use in specialty applications. Overall, ADV has a bright future in clinical application because the small size of nanodroplets greatly reduces the rate of clearance compared to larger contrast agent bubbles and yet provides the advantages of ultrasonographic contrast, acoustic cavitation, and nontoxicity of conventional perfluorocarbon contrast agent bubbles.

  16. Anisotropy of acoustic properties in paratellurite

    International Nuclear Information System (INIS)

    Parygin, Vladimir N.

    1996-01-01

    One of the peculiarities of the TeO 2 crystal consists of its strong acoustic anisotropy. This anisotropy demonstrates itself by acoustic energy walk-off and anisotropic distortion of an acoustic beam. Four constants completely characterise the acoustic anisotropy of the medium. In this paper these constants are calculated for various directions of the acoustic beam in crystal. (authors)

  17. Canada Basin Acoustic Propagation Experiment (CANAPE)

    Science.gov (United States)

    2015-09-30

    acoustic communications, acoustic navigation, or acoustic remote sensing of the ocean interior . RELATED PROJECTS The 2015 CANAPE pilot study was a...1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Canada Basin Acoustic Propagation Experiment (CANAPE...ocean structure. Changes in sea ice and the water column affect both acoustic propagation and ambient noise. This implies that what was learned

  18. Acoustically enhanced heat transport

    Energy Technology Data Exchange (ETDEWEB)

    Ang, Kar M.; Hung, Yew Mun; Tan, Ming K., E-mail: tan.ming.kwang@monash.edu [School of Engineering, Monash University Malaysia, 47500 Bandar Sunway, Selangor (Malaysia); Yeo, Leslie Y. [Micro/Nanophysics Research Laboratory, RMIT University, Melbourne, VIC 3001 (Australia); Friend, James R. [Department of Mechanical and Aerospace Engineering, University of California, San Diego, California 92093 (United States)

    2016-01-15

    We investigate the enhancement of heat transfer in the nucleate boiling regime by inducing high frequency acoustic waves (f ∼ 10{sup 6} Hz) on the heated surface. In the experiments, liquid droplets (deionized water) are dispensed directly onto a heated, vibrating substrate. At lower vibration amplitudes (ξ{sub s} ∼ 10{sup −9} m), the improved heat transfer is mainly due to the detachment of vapor bubbles from the heated surface and the induced thermal mixing. Upon increasing the vibration amplitude (ξ{sub s} ∼ 10{sup −8} m), the heat transfer becomes more substantial due to the rapid bursting of vapor bubbles happening at the liquid-air interface as a consequence of capillary waves travelling in the thin liquid film between the vapor bubble and the air. Further increases then lead to rapid atomization that continues to enhance the heat transfer. An acoustic wave displacement amplitude on the order of 10{sup −8} m with 10{sup 6} Hz order frequencies is observed to produce an improvement of up to 50% reduction in the surface temperature over the case without acoustic excitation.

  19. Bilateral acoustic neuromas.

    Science.gov (United States)

    Anand, V T; Byrnes, D P; Walby, A P; Kerr, A G

    1993-10-01

    This article reviews 12 patients with bilateral acoustic neuromas. The sex incidence was equal and the mean age at diagnosis was 26.2 years. The family history was positive in nine of the patients. Five patients have had incomplete surgical removal of acoustic neuromas on both sides. Two of them are completely deaf and the other three have severe sensorineural hearing loss in one ear and no hearing in the other ear. In five patients the tumour on one side has been operated on and the other side is being observed with at least short-term preservation of good hearing. The remaining two patients died of intra-cranial complications, one of them post-operatively. Four patients developed facial palsy immediately following surgery and one developed facial weakness 6 months after surgery. Guidelines are discussed for the care of these patients including the timing of surgery and alternative treatment options (observation, radio-surgery and chemotherapy). This is essentially a group of young individuals who have had multiple operations for bilateral acoustic tumours and associated manifestations and for whom the disease and the sequelae of treatment can be tragic.

  20. High-Frequency Seafloor Acoustics

    CERN Document Server

    Jackson, Darrell R

    2007-01-01

    High-Frequency Seafloor Acoustics is the first book in a new series sponsored by the Office of Naval Research on the latest research in underwater acoustics. This exciting new title provides ready access to experimental data, theory, and models relevant to high-frequency seafloor acoustics and will be of interest to sonar engineers and researchers working in underwater acoustics. The physical characteristics of the seafloor affecting acoustic propagation and scattering are covered, including physical and geoacoustic properties and surface roughness. Current theories for acoustic propagation in sediments are presented along with corresponding models for reflection, scattering, and seafloor penetration. The main text is backed up by an extensive bibliography and technical appendices.