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Sample records for acoustical holography nah

  1. Nearfield acoustic holography. I - Theory of generalized holography and the development of NAH

    NASA Technical Reports Server (NTRS)

    Maynard, J. D.; Williams, E. G.; Lee, Y.

    1985-01-01

    Because its underlying principles are so fundamental, holography has been studied and applied in many areas of science. Recently, a technique has been developed which takes the maximum advantage of the fundamental principles and extracts much more information from a hologram than is customarily associated with such a measurement. In this paper the fundamental principles of holography are reviewed, and a sound radiation measurement system, called nearfield acoustic holography (NAH), which fully exploits the fundamental principles, is described.

  2. Progress in acoustic holography

    NASA Astrophysics Data System (ADS)

    Hildebrand, B. P.

    1985-01-01

    The theory underlying the methods used in acoustic holography (the real-time liquid surface levitation and the scanning holography methods) and in electromagnetic holography, which uses electromagnetic impulses (radar) or electromagnetic waves (eddy current) is developed. These holographic techniques are illustrated with experimental results, including the use of the liquid surface levitation method for inspecting fiberglass laminate tubes, and examples of the time-of-flight holographic images, the coherent ultrasonic images, multifrequency ultrasonic images, and the synthetic aperture holography images obtained by the use of the scanning holography methodology. Other examples illustrate applications of radar holography and eddy current holography. These examples are used to refute some traditional negative comments on nonoptical holography.

  3. Acoustic Holography

    NASA Astrophysics Data System (ADS)

    Kim, Yang-Hann

    One of the subtle problems that make noise control difficult for engineers is the invisibility of noise or sound. A visual image of noise often helps to determine an appropriate means for noise control. There have been many attempts to fulfill this rather challenging objective. Theoretical (or numerical) means for visualizing the sound field have been attempted, and as a result, a great deal of progress has been made. However, most of these numerical methods are not quite ready for practical applications to noise control problems. In the meantime, rapid progress with instrumentation has made it possible to use multiple microphones and fast signal-processing systems. Although these systems are not perfect, they are useful. A state-of-the-art system has recently become available, but it still has many problematic issues; for example, how can one implement the visualized noise field. The constructed noise or sound picture always consists of bias and random errors, and consequently, it is often difficult to determine the origin of the noise and the spatial distribution of the noise field. Section 26.2 of this chapter introduces a brief history, which is associated with sound visualization, acoustic source identification methods and what has been accomplished with a line or surface array. Section 26.2.3 introduces difficulties and recent studies, including de-Dopplerization and de-re verberation methods, both essential for visualizing a moving noise source, such as occurs for cars or trains. This section also addresses what produces ambiguity in realizing real sound sources in a room or closed space. Another major issue associated with sound/noise visualization is whether or not we can distinguish between mutual dependencies of noise in space (Sect. 26.2.4); for example, we are asked to answer the question, Can we see two birds singing or one bird with two beaks?

  4. Acoustic Holography

    NASA Astrophysics Data System (ADS)

    Kim, Yang-Hann

    One of the subtle problems that make noise control difficult for engineers is the invisibility of noise or sound. A visual image of noise often helps to determine an appropriate means for noise control. There have been many attempts to fulfill this rather challenging objective. Theoretical (or numerical) means for visualizing the sound field have been attempted, and as a result, a great deal of progress has been made. However, most of these numerical methods are not quite ready for practical applications to noise control problems. In the meantime, rapid progress with instrumentation has made it possible to use multiple microphones and fast signal-processing systems. Although these systems are not perfect, they are useful. A state-of-the-art system has recently become available, but it still has many problematic issues; for example, how can one implement the visualized noise field. The constructed noise or sound picture always consists of bias and random errors, and consequently, it is often difficult to determine the origin of the noise and the spatial distribution of the noise field. Section 26.2 of this chapter introduces a brief history, which is associated with "sound visualization," acoustic source identification methods and what has been accomplished with a line or surface array. Section 26.2.3 introduces difficulties and recent studies, including de-Dopplerization and de-reverberation methods, both essentialfor visualizing a moving noise source, such as occurs for cars or trains. This section also addresses what produces ambiguity in realizing real sound sources in a room or closed space. Another major issue associated with sound/noise visualization is whether or not we can distinguish between mutual dependencies of noise in space (Sect. 26.2.4); for example, we are asked to answer the question, "Can we see two birds singing or one bird with two beaks?"

  5. Fast wideband acoustical holography.

    PubMed

    Hald, Jørgen

    2016-04-01

    Patch near-field acoustical holography methods like statistically optimized near-field acoustical holography and equivalent source method are limited to relatively low frequencies, where the average array-element spacing is less than half of the acoustic wavelength, while beamforming provides useful resolution only at medium-to-high frequencies. With adequate array design, both methods can be used with the same array. But for holography to provide good low-frequency resolution, a small measurement distance is needed, whereas beamforming requires a larger distance to limit sidelobe issues. The wideband holography method of the present paper was developed to overcome that practical conflict. Only a single measurement is needed at a relatively short distance and a single result is obtained covering the full frequency range. The method uses the principles of compressed sensing: A sparse sound field representation is assumed with a chosen set of basis functions, a measurement is taken with an irregular array, and the inverse problem is solved with a method that enforces sparsity in the coefficient vector. Instead of using regularization based on the 1-norm of the coefficient vector, an iterative solution procedure is used that promotes sparsity. The iterative method is shown to provide very similar results in most cases and to be computationally much more efficient. PMID:27106299

  6. Volumetric Imaging Using Acoustical Holography

    NASA Astrophysics Data System (ADS)

    Garlick, T. F.; Garlick, G. F.

    Transmission acoustical holography holds tremendous promise for medical imaging applications. As with optical holography, an image is obtained using the interference of two coherent acoustic sources, the transmitted object wave with a reference wave. Although resultant images are true holograms, depth can be difficult to quantify and an entire volume in one image can often result in "too much" information. Since Physicians/Radiologists are often interested in viewing a single plane at a time, techniques have been developed to generate acoustic holograms of "slices" within a volume. These primarily include focused transmission holography with spatial and frequency filtering techniques. These techniques along with an overview and current status of acoustical holography in medical imaging applications will be presented

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

    NASA Astrophysics Data System (ADS)

    Hu, Bo; Yang, Desen; Sun, Yu

    2010-06-01

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

  8. Acoustic emission linear pulse holography

    DOEpatents

    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.

  9. Planar nearfield acoustical holography in moving fluid medium at subsonic and uniform velocity.

    PubMed

    Kwon, Hyu-Sang; Niu, Yaying; Kim, Yong-Joe

    2010-10-01

    Nearfield acoustical holography (NAH) data measured by using a microphone array attached to a high-speed aircraft or ground vehicle include significant airflow effects. For the purpose of processing the measured NAH data, an improved nearfield acoustical holography procedure is introduced that includes the effects of a fluid medium moving at a subsonic and uniform velocity. The convective wave equation along with the convective Euler's equation is used to develop the proposed NAH procedure. A mapping function between static and moving fluid medium cases is derived from the convective wave equation. Then, a conventional wave number filter designed for static fluid media is modified to be applicable to the moving fluid cases by applying the mapping function to the static wave number filter. In order to validate the proposed NAH procedure, a monopole simulation at the airflow speed of Mach=-0.6 is conducted. The reconstructed acoustic fields obtained by applying the proposed NAH procedure to the simulation data agree well with directly-calculated acoustic fields. Through an experiment with two loudspeakers performed in a wind tunnel operating at Mach=-0.12, it is shown that the proposed NAH procedure can be also used to reconstruct the sound fields radiated from the two loudspeakers. PMID:20968355

  10. Experimental study using nearfield acoustic holography of sound transmission through fuselage sidewall structures

    NASA Technical Reports Server (NTRS)

    Maynard, J. D.

    1986-01-01

    The reduction of cabin noise in lightweight, propeller-driven aircraft is an especially difficult problem in noise control. Nearfield Acoustic Holography (NAH) was used to determine the mode of vibration and acoustic intensity for panels which differed in: construction (number of stiffening ribs, size of stifening ribs, construction material, and panel surface curvature); boundary support condition (free edge condition or clamped edge condition); and mode of excitation (structural-borne forces or airborne forces). The different samples of aircraft panels are described and the measurement of the natural response frequencies was discussed under various boundary support and excitation conditions. The results of the NAH measurements are presented.

  11. Nonlinear holography for acoustic wave detection

    NASA Astrophysics Data System (ADS)

    Bortolozzo, U.; Dolfi, D.; Huignard, J. P.; Molin, S.; Peigné, A.; Residori, S.

    2015-03-01

    A liquid crystal medium is used to perform nonlinear dynamic holography and is coupled with multimode optical fibers for optical sensing applications. Thanks to the adaptive character of the nonlinear holography, and to the sensitivity of the multimode fibers, we demonstrate that the system is able to perform efficient acoustic wave detection even with noisy signals. The detection limit is estimated and multimode versus monomode optical fiber are compared. Finally, a wavelength multiplexing protocol is implemented for the spatial localization of the acoustic disturbances.

  12. A mapping relationship based near-field acoustic holography with spherical fundamental solutions for Helmholtz equation

    NASA Astrophysics Data System (ADS)

    Wu, Haijun; Jiang, Weikang; Zhang, Haibin

    2016-07-01

    In the procedure of the near-field acoustic holography (NAH) based on the fundamental solutions for Helmholtz equation (FS), the number of FS and the measurement setup to obtain their coefficients are two crucial issues to the successful reconstruction. The current work is motivated to develop a framework for the NAH which supplies a guideline to the determination of the number of FS as well as an optimized measurement setup. A mapping relationship between modes on surfaces of boundary and hologram is analytically derived by adopting the modes as FS in spherical coordinates. Thus, reconstruction is converted to obtain the coefficients of participant modes on holograms. In addition, an integral identity is firstly to be derived for the modes on convex surfaces, which is useful in determining the inefficient or evanescent modes for acoustic radiation in free space. To determine the number of FS adopted in the mapping relationship based NAH (MRS-based NAH), two approaches are proposed to supply reasonable estimations with criteria of point-wise pressure and energy, respectively. A technique to approximate a specific degree of mode on patches by a set of locally orthogonal patterns is explored for three widely used holograms, such as planar, cylindrical and spherical holograms, which results in an automatic determinations of the number and position of experimental setup for a given tolerance. Numerical examples are set up to validate the theory and techniques in the MRS-based NAH. Reconstructions of a cubic model demonstrate the potential of the proposed method for regular models even with corners and shapers. Worse results for the elongated cylinder with two spherical caps reveal the deficiency of the MRS-based NAH for irregular models which is largely due to the adopted modes are FS in spherical coordinates. The NAH framework pursued in the current work provides a new insight to the reconstruction procedure based on the FS in spherical coordinates.

  13. Acoustic-emission linear-pulse holography

    SciTech Connect

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

    1982-06-01

    This paper describes Acoustic Emission Linear Pulse Holography which combines the advantages of linear imaging and acoustic emission into a single NDE inspection system. This unique system produces a chronological linear holographic image of a flaw by utilizing the acoustic energy emitted during crack growth. Conventional linear holographic imaging uses an ultrasonic transducer to transmit energy into the volume being imaged. When the crack or defect reflects that energy, the crack acts as a new source of acoustic waves. To formulate an image of that source, a receiving transducer is scanned over the volume of interest and the phase of the received signals is measured at successive points on the scan. The innovation proposed here is the utilization of the crack generated acoustic emission as the acoustic source and generation of a line image of the crack as it grows. A thirty-two point sampling array is used to construct phase-only linear holograms of simulated acoustic emission sources on large metal plates. The phases are calculated using the pulse time-of-flight (TOF) times from the reference transducer to the array of receivers. Computer reconstruction of the image is accomplished using a one-dimensional FFT algorithm (i.e., backward wave). Experimental results are shown which graphically illustrate the unique acoustic emission images of a single point and a linear crack in a 100 mm x 1220 mm x 1220 mm aluminum plate.

  14. Acoustic emission linear pulse holography

    DOEpatents

    Collins, H. Dale; Busse, Lawrence J.; Lemon, Douglas K.

    1985-01-01

    Defects in a structure are imaged as they propagate, using their emitted acoustic energy as a monitored source. Short bursts of acoustic energy propagate through the structure to a discrete element receiver array. A reference timing transducer located between the array and the inspection zone initiates a series of time-of-flight measurements. A resulting series of time-of-flight measurements are then treated as aperture data and are transferred to a computer for reconstruction of a synthetic linear holographic image. The images can be displayed and stored as a record of defect growth.

  15. Acoustic emission linear pulse holography

    SciTech Connect

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

    1985-07-30

    Defects in a structure are imaged as they propagate, using their emitted acoustic energy as a monitored source. Short bursts of acoustic energy propagate through the structure to a discrete element receiver array. A reference timing transducer located between the array and the inspection zone initiates a series of time-of-flight measurements. A resulting series of time-of-flight measurements are then treated as aperture data and are transferred to a computer for reconstruction of a synthetic linear holographic image. The images can be displayed and stored as a record of defect growth.

  16. Experimental study using Nearfield Acoustical Holography of sound transmission fuselage sidewall structures

    NASA Technical Reports Server (NTRS)

    Maynard, J. D.

    1983-01-01

    This project involves the development of the Nearfield Acoustic Holography (NAH) technique (in particular its extension from single frequency to wideband noise measurement) and its application in a detailed study of the noise radiation characteristics of several samples of aircraft sidewall panels. With the extensive amount of information provided by the NAH technique, the properties of the sound field radiated by the panels may be correlated with their structure, mounting, and excitation (single frequency or wideband, spatially correlated or uncorrelated, structure-borne). The work accomplished at the beginning of this grant period included: (1) Calibration of the 256 microphone array and test of its accuracy. (2) extension of the facility to permit measurements on wideband noise sources. The extensions incuded the addition of high-speed data acquisition hardware and an array processor, and the development of new software. (3) Installation of motion picture graphics for correlating panel motion with structure, mounting, radiation, etc. (4) Development of new holographic data processing techniques.

  17. Identification of vibration excitations from acoustic measurements using near field acoustic holography and the force analysis technique

    NASA Astrophysics Data System (ADS)

    Pézerat, C.; Leclère, Q.; Totaro, N.; Pachebat, M.

    2009-10-01

    This study presents a method of using acoustic holography and the force analysis technique to identify vibration sources from radiated noise measurements. The structure studied is a plate excited by a shaker on which three measurements were performed: the first is a reference measurement of plate velocity obtained by scanning laser vibrometry, the second is based on sound pressure measurements in the near field of the structure, and the third is the measurement of normal acoustic velocities by using a p-U probe recently developed by Microflown Technologies. This was followed by the application of classical NAH, known as pressure-to-velocity holography and velocity-to-velocity holography to predict the plate velocity field from acoustic measurements at distances of 1 and 5 cm. Afterwards, the force analysis technique, also known as the RIFF technique, is applied with these five data sets. The principle is to inject the displacement field of the structure into its equation of motion and extract the resulting force distribution. This technique requires regularization done by a low-pass filter in the wavenumber domain. Apart from pressure-to-velocity holography at 5 cm, the reconstructed force distribution allows localizing the excitation point in the measurement area. FAT regularization is also shown to improve results as its cutoff wavenumber is optimized with the natural wavenumber of the plate. Lastly, quantitative force values are extracted from force distributions at all frequencies of the band 0-4 kHz studied and compared with the force spectrum measured directly by a piezoelectric sensor.

  18. Patch nearfield acoustic holography combined with sound field separation technique applied to a non-free field

    NASA Astrophysics Data System (ADS)

    Bi, ChuanXing; Jing, WenQian; Zhang, YongBin; Xu, Liang

    2015-02-01

    The conventional nearfield acoustic holography (NAH) is usually based on the assumption of free-field conditions, and it also requires that the measurement aperture should be larger than the actual source. This paper is to focus on the problem that neither of the above-mentioned requirements can be met, and to examine the feasibility of reconstructing the sound field radiated by partial source, based on double-layer pressure measurements made in a non-free field by using patch NAH combined with sound field separation technique. And also, the sensitivity of the reconstructed result to the measurement error is analyzed in detail. Two experiments involving two speakers in an exterior space and one speaker inside a car cabin are presented. The experimental results demonstrate that the patch NAH based on single-layer pressure measurement cannot obtain a satisfied result due to the influences of disturbing sources and reflections, while the patch NAH based on double-layer pressure measurements can successfully remove these influences and reconstruct the patch sound field effectively.

  19. Near-field acoustic holography using sparse regularization and compressive sampling principles.

    PubMed

    Chardon, Gilles; Daudet, Laurent; Peillot, Antoine; Ollivier, François; Bertin, Nancy; Gribonval, Rémi

    2012-09-01

    Regularization of the inverse problem is a complex issue when using near-field acoustic holography (NAH) techniques to identify the vibrating sources. This paper shows that, for convex homogeneous plates with arbitrary boundary conditions, alternative regularization schemes can be developed based on the sparsity of the normal velocity of the plate in a well-designed basis, i.e., the possibility to approximate it as a weighted sum of few elementary basis functions. In particular, these techniques can handle discontinuities of the velocity field at the boundaries, which can be problematic with standard techniques. This comes at the cost of a higher computational complexity to solve the associated optimization problem, though it remains easily tractable with out-of-the-box software. Furthermore, this sparsity framework allows us to take advantage of the concept of compressive sampling; under some conditions on the sampling process (here, the design of a random array, which can be numerically and experimentally validated), it is possible to reconstruct the sparse signals with significantly less measurements (i.e., microphones) than classically required. After introducing the different concepts, this paper presents numerical and experimental results of NAH with two plate geometries, and compares the advantages and limitations of these sparsity-based techniques over standard Tikhonov regularization. PMID:22978881

  20. On optimal retreat distance for the equivalent source method-based nearfield acoustical holography.

    PubMed

    Bai, Mingsian R; Chen, Ching-Cheng; Lin, Jia-Hong

    2011-03-01

    As a basic form of the equivalent source method (ESM) that is used to nearfield acoustical holography (NAH) problems, discrete monopoles are utilized to represent the sound field of interest. When setting up the virtual source distribution, it is vital to maintain a "retreat distance" between the virtual sources and the actual source surface such that reconstruction would not suffer from singularity problems. However, one cannot increase the distance without bound because of the ill-posedness inherent in the reconstruction process with large distance. In prior research, 1-2 times lattice spacing, or the inter-element distance of microphones, is generally recommended as retreat distance in using the ESM-based NAH. While this rule has shown to yield good results in many cases, the optimal choice is a complicated issue that depends on frequency, geometry of the physical source, content of evanescent waves, distribution of sensors and virtual sources, etc. This paper deals about attaining the best compromise between the reconstruction errors induced by the point source singularity; the reconstruction ill-posedness is an interesting problem in its own right. The paper revisits this issue, with the aid of an optimization algorithm based on the golden section search and parabolic interpolation. Numerical simulations were conducted for a baffled planar piston source and a spherically baffled piston source. The results revealed that the retreat distance appropriate for the ESM ranged from 0.4 to 0.5 times the spacing for the planar piston, while from 0.8 to 1.7 times average spacing for the spherical piston. Experiments carried out for a vibrating aluminum plate also revealed that the retreat distance with 0.5 times the spacing yielded better reconstructed velocity than those with 1/20 and 1 times the spacing. PMID:21428505

  1. A gearbox fault diagnosis scheme based on near-field acoustic holography and spatial distribution features of sound field

    NASA Astrophysics Data System (ADS)

    Lu, Wenbo; Jiang, Weikang; Yuan, Guoqing; Yan, Li

    2013-05-01

    Vibration signal analysis is the main technique in machine condition monitoring or fault diagnosis, whereas in some cases vibration-based diagnosis is restrained because of its contact measurement. Acoustic-based diagnosis (ABD) with non-contact measurement has received little attention, although sound field may contain abundant information related to fault pattern. A new scheme of ABD for gearbox based on near-field acoustic holography (NAH) and spatial distribution features of sound field is presented in this paper. It focuses on applying distribution information of sound field to gearbox fault diagnosis. A two-stage industrial helical gearbox is experimentally studied in a semi-anechoic chamber and a lab workshop, respectively. Firstly, multi-class faults (mild pitting, moderate pitting, severe pitting and tooth breakage) are simulated, respectively. Secondly, sound fields and corresponding acoustic images in different gearbox running conditions are obtained by fast Fourier transform (FFT) based NAH. Thirdly, by introducing texture analysis to fault diagnosis, spatial distribution features are extracted from acoustic images for capturing fault patterns underlying the sound field. Finally, the features are fed into multi-class support vector machine for fault pattern identification. The feasibility and effectiveness of our proposed scheme is demonstrated on the good experimental results and the comparison with traditional ABD method. Even with strong noise interference, spatial distribution features of sound field can reliably reveal the fault patterns of gearbox, and thus the satisfactory accuracy can be obtained. The combination of histogram features and gray level gradient co-occurrence matrix features is suggested for good diagnosis accuracy and low time cost.

  2. Cylindrical acoustical holography applied to full-scale jet noise.

    PubMed

    Wall, Alan T; Gee, Kent L; Neilsen, Tracianne B; Krueger, David W; James, Michael M

    2014-09-01

    Near-field acoustical holography methods are used to predict sound radiation from an engine installed on a high-performance military fighter aircraft. Cylindrical holography techniques are an efficient approach to measure the large and complex sound fields produced by full-scale jets. It is shown that a ground-based, one-dimensional array of microphones can be used in conjunction with a cylindrical wave function field representation to provide a holographic reconstruction of the radiated sound field at low frequencies. In the current work, partial field decomposition methods and numerical extrapolation of data beyond the boundaries of the hologram aperture are required prior to holographic projection. Predicted jet noise source distributions and directionality are shown for four frequencies between 63 and 250 Hz. It is shown that the source distribution narrows and moves upstream, and that radiation directionality shifts toward the forward direction, with increasing frequency. A double-lobe feature of full-scale jet radiation is also demonstrated. PMID:25190387

  3. Near-field acoustical holography of military jet aircraft noise

    NASA Astrophysics Data System (ADS)

    Wall, Alan T.; Gee, Kent L.; Neilsen, Tracianne; Krueger, David W.; Sommerfeldt, Scott D.; James, Michael M.

    2010-10-01

    Noise radiated from high-performance military jet aircraft poses a hearing-loss risk to personnel. Accurate characterization of jet noise can assist in noise prediction and noise reduction techniques. In this work, sound pressure measurements were made in the near field of an F-22 Raptor. With more than 6000 measurement points, this is the most extensive near-field measurement of a high-performance jet to date. A technique called near-field acoustical holography has been used to propagate the complex pressure from a two- dimensional plane to a three-dimensional region in the jet vicinity. Results will be shown and what they reveal about jet noise characteristics will be discussed.

  4. Holography.

    ERIC Educational Resources Information Center

    Klein, H. Arthur

    Holography is a process which numbers among its many applications the creation of holograms--unique three dimensional photographs that show spatial relations and shifts just as they exist in reality. This book recounts the history of holography, tracing its development from Euclid's theory of light rays through Huygens' theory of wave motion to…

  5. Analytical study of acousto/optical holography-interfacing methods for acoustical and optical holography NDT research

    NASA Technical Reports Server (NTRS)

    El-Sum, H. M. A.

    1976-01-01

    The international status of the art of acousto optical imaging techniques adaptable to nondestructive testing and, interfacing methods for acoustical and optical holography in nondestructive testing research are studied. Evaluation of 20 different techniques encompassed investigation of varieties of detectors and detection schemes, all of which are described and summarized. Related investigation is reported in an Appendix. Important remarks on image quality, factors to be considered in designing a particular system, and conclusions and recommendations are presented. Three bibliographies are included.

  6. Haptic Holography: Acoustic Space and the Evolution of the Whole Message

    NASA Astrophysics Data System (ADS)

    Logan, N.

    2013-02-01

    The paper argues that the Haptic Holography Work Station is an example of a medium that fit's with McLuhan's notion of Acoustic Space, that is it is a medium which stimulates more than one sense of perception at a time. As a result, the Haptic Holography Work Station transmits information about the subject much more rapidly than other media that precedes it, be it text, photography or television.

  7. Tomographic reconstruction of transient acoustic fields recorded by pulsed TV holography.

    PubMed

    Gren, P; Schedin, S; Li, X

    1998-02-10

    Pulsed TV holography combined with computerized tomography (CT) are used to evaluate the three-dimensional distribution of transient acoustic fields in air. Experiments are performed with an electrical discharge between two electrodes as the sound source. Holograms from several directions of the acoustic field are recorded directly onto a CCD detector by use of a double-pulsed ruby laser as the light source. Phase maps, representing projections of the acoustic field, are evaluated quantitatively from the recorded holograms. The projections are used for the CT reconstruction to evaluate the pressure-field distribution in any cross section of the measured volume of air. PMID:18268660

  8. Military jet noise source imaging using multisource statistically optimized near-field acoustical holography.

    PubMed

    Wall, Alan T; Gee, Kent L; Neilsen, Tracianne B; McKinley, Richard L; James, Michael M

    2016-04-01

    The identification of acoustic sources is critical to targeted noise reduction efforts for jets on high-performance tactical aircraft. This paper describes the imaging of acoustic sources from a tactical jet using near-field acoustical holography techniques. The measurement consists of a series of scans over the hologram with a dense microphone array. Partial field decomposition methods are performed to generate coherent holograms. Numerical extrapolation of data beyond the measurement aperture mitigates artifacts near the aperture edges. A multisource equivalent wave model is used that includes the effects of the ground reflection on the measurement. Multisource statistically optimized near-field acoustical holography (M-SONAH) is used to reconstruct apparent source distributions between 20 and 1250 Hz at four engine powers. It is shown that M-SONAH produces accurate field reconstructions for both inward and outward propagation in the region spanned by the physical hologram measurement. Reconstructions across the set of engine powers and frequencies suggests that directivity depends mainly on estimated source location; sources farther downstream radiate at a higher angle relative to the inlet axis. At some frequencies and engine powers, reconstructed fields exhibit multiple radiation lobes originating from overlapped source regions, which is a phenomenon relatively recently reported for full-scale jets. PMID:27106340

  9. Underwater patch near-field acoustical holography based on particle velocity and vector hydrophone array

    NASA Astrophysics Data System (ADS)

    Hu, Bo; Yang, DeSen; Li, SiChun; Sun, Yu; Mo, ShiQi; Shi, ShengGuo

    2012-11-01

    One-step patch near-field acoustical holography (PNAH) is a powerful tool for identifying noise sources from the partially known sound pressure field. The acoustical property to be reconstructed on the surface of interest is related to the partially measured pressure on the hologram surface in terms of sampling and bandlimiting matrices, which cost more in computation. A one-step procedure based on measuring of the normal component of the particle velocity is described, including the mathematical formulation. The numerical simulation shows that one-step PNAH based on particle velocity can obtain more accurately reconstructed results and it is also less sensitive to noise than the method based on pressure. These findings are confirmed by an underwater near-field acoustical holography experiment conducted with a vector hydrophone array. The experimental results have illustrated the high performance of one-step PNAH based on particle velocity in the reconstruction of sound field and the advantages of a vector hydrophone array in an underwater near-field measurement.

  10. Digital Stroboscopic Holography Setup for Deformation Measurement at Both Quasi-Static and Acoustic Frequencies

    NASA Astrophysics Data System (ADS)

    De Greef, Daniël; Soons, Joris; Dirckx, Joris J. J.

    2014-10-01

    A setup for digital stroboscopic holography that combines the advantages of full-field digital holographic interferometry with a high temporal resolution is presented. The setup can be used to identify and visualize complicated vibrational patterns with nanometer amplitudes, ranging from quasi-static to high frequency vibrations. By using a high-energy pulsed laser, single-shot holograms can be recorded and stability issues are avoided. Results are presented for an acoustically stimulated rubber membrane and the technique is evaluated by means of an accuracy and a repeatability test. The presented technique offers wide application possibilities in areas such as biomechanics and industrial testing.

  11. Acoustic Holography of the Solar Convection Zone with SOHO-MDI Observations

    NASA Technical Reports Server (NTRS)

    Lindsey, Charles

    2005-01-01

    The original grant with the title stated above was NAG5-10984, awarded to the Solar Physics Research Corporation (SPRC) in July, 2001, and was to be a three-year project. The basic theme of the project was the development and application of computational seismic holography for imaging, diagnostics, and monitoring of magnetic anomalies beneath active regions, in the deep solar interior, and on the Sun's far surface. The project was roughly separated into the following five tasks: (1) A holographic survey of active regions. (2) p-Mode absorption diagnostics of magnetic regions. (3) Acoustic modeling of the shallow subphotospheres of active regions and the quiet-Sun supergranulation based on phase-correlation seismic holography. (4) Seismic holography of the deep convection zone. (5) Improvements in holographic imaging of the far surface of the Sun. Following the death of Karen Harvey, President of SPRC, during the first year, the grant was transferred to Northwest Research Associates as NAG5-12901. Substantial but progress had been made on most of the above tasks in the first year under NAG5-10984, but none were completed. This work was continued under NAG5-12901.

  12. Acoustic holography as a metrological tool for characterizing medical ultrasound sources and fields

    PubMed Central

    Sapozhnikov, Oleg A.; Tsysar, Sergey A.; Khokhlova, Vera A.; Kreider, Wayne

    2015-01-01

    Acoustic holography is a powerful technique for characterizing ultrasound sources and the fields they radiate, with the ability to quantify source vibrations and reduce the number of required measurements. These capabilities are increasingly appealing for meeting measurement standards in medical ultrasound; however, associated uncertainties have not been investigated systematically. Here errors associated with holographic representations of a linear, continuous-wave ultrasound field are studied. To facilitate the analysis, error metrics are defined explicitly, and a detailed description of a holography formulation based on the Rayleigh integral is provided. Errors are evaluated both for simulations of a typical therapeutic ultrasound source and for physical experiments with three different ultrasound sources. Simulated experiments explore sampling errors introduced by the use of a finite number of measurements, geometric uncertainties in the actual positions of acquired measurements, and uncertainties in the properties of the propagation medium. Results demonstrate the theoretical feasibility of keeping errors less than about 1%. Typical errors in physical experiments were somewhat larger, on the order of a few percent; comparison with simulations provides specific guidelines for improving the experimental implementation to reduce these errors. Overall, results suggest that holography can be implemented successfully as a metrological tool with small, quantifiable errors. PMID:26428789

  13. Acoustic holography: Problems associated with construction and reconstruction techniques

    NASA Technical Reports Server (NTRS)

    Singh, J. J.

    1978-01-01

    The implications of the difference between the inspecting and interrogating radiations are discussed. For real-time, distortionless, sound viewing, it is recommended that infrared radiation of wavelength comparable to the inspecting sound waves be used. The infrared images can be viewed with (IR visible) converter phosphors. The real-time display of the visible image of the acoustically-inspected object at low sound levels such as are used in medical diagnosis is evaluated. In this connection attention is drawn to the need for a phosphor screen which is such that its optical transmission at any point is directly related to the incident electron beam intensity at that point. Such a screen, coupled with an acoustical camera, can enable instantaneous sound wave reconstruction.

  14. Acoustical studies of the steelpan and HANG: Phase-sensitive holography and sound intensity measurements

    NASA Astrophysics Data System (ADS)

    Morrison, Andrew C. H.

    The Caribbean steelpan and an instrument closely related, the HANG, are two of the most, interesting acoustic musical instruments developed in the last century. Although simple in design, the acoustic properties of the steelpan and HANG are surprisingly complicated. Holographic interferometry was used to determine the resonances of a low tenor steelpan and a pentatonic HANG. Placement of a vibrating mirror in the optical path of the reference beam expands the capabilities of the holography system to include phase measurements. Phase maps and phase response curves of several low resonances of notes on a steelpan and HANG are shown. Sound intensity measurements were acquired to explore the relationship between the resonances and the radiated sound field. The instruments were placed in an anechoic chamber, and selected notes were excited electromagnetically with a swept sinusoid signal. A two-microphone probe was used to gather sound intensity measurements. Sound intensity reaps of the first three harmonics are shown for notes on both instruments.

  15. Investigation of an acoustical holography system for real-time imaging

    NASA Astrophysics Data System (ADS)

    Fecht, Barbara A.; Andre, Michael P.; Garlick, George F.; Shelby, Ronald L.; Shelby, Jerod O.; Lehman, Constance D.

    1998-07-01

    A new prototype imaging system based on ultrasound transmission through the object of interest -- acoustical holography -- was developed which incorporates significant improvements in acoustical and optical design. This system is being evaluated for potential clinical application in the musculoskeletal system, interventional radiology, pediatrics, monitoring of tumor ablation, vascular imaging and breast imaging. System limiting resolution was estimated using a line-pair target with decreasing line thickness and equal separation. For a swept frequency beam from 2.6 - 3.0 MHz, the minimum resolution was 0.5 lp/mm. Apatite crystals were suspended in castor oil to approximate breast microcalcifications. Crystals from 0.425 - 1.18 mm in diameter were well resolved in the acoustic zoom mode. Needle visibility was examined with both a 14-gauge biopsy needle and a 0.6 mm needle. The needle tip was clearly visible throughout the dynamic imaging sequence as it was slowly inserted into a RMI tissue-equivalent breast biopsy phantom. A selection of human images was acquired in several volunteers: a 25 year-old female volunteer with normal breast tissue, a lateral view of the elbow joint showing muscle fascia and tendon insertions, and the superficial vessels in the forearm. Real-time video images of these studies will be presented. In all of these studies, conventional sonography was used for comparison. These preliminary investigations with the new prototype acoustical holography system showed favorable results in comparison to state-of-the-art pulse-echo ultrasound and demonstrate it to be suitable for further clinical study. The new patient interfaces will facilitate orthopedic soft tissue evaluation, study of superficial vascular structures and potentially breast imaging.

  16. Scaling of plane-wave functions in statistically optimized near-field acoustic holography.

    PubMed

    Hald, Jørgen

    2014-11-01

    Statistically Optimized Near-field Acoustic Holography (SONAH) is a Patch Holography method, meaning that it can be applied in cases where the measurement area covers only part of the source surface. The method performs projections directly in the spatial domain, avoiding the use of spatial discrete Fourier transforms and the associated errors. First, an inverse problem is solved using regularization. For each calculation point a multiplication must then be performed with two transfer vectors--one to get the sound pressure and the other to get the particle velocity. Considering SONAH based on sound pressure measurements, existing derivations consider only pressure reconstruction when setting up the inverse problem, so the evanescent wave amplification associated with the calculation of particle velocity is not taken into account in the regularized solution of the inverse problem. The present paper introduces a scaling of the applied plane wave functions that takes the amplification into account, and it is shown that the previously published virtual source-plane retraction has almost the same effect. The effectiveness of the different solutions is verified through a set of simulated measurements. PMID:25373969

  17. Toward soft-tissue elastography using digital holography to monitor surface acoustic waves.

    PubMed

    Li, Shiguang; Mohan, Karan D; Sanders, William W; Oldenburg, Amy L

    2011-11-01

    Measuring the elasticity distribution inside the human body is of great interest because elastic abnormalities can serve as indicators of several diseases. We present a method for mapping elasticity inside soft tissues by imaging surface acoustic waves (SAWs) with digital holographic interferometry. With this method, we show that SAWs are consistent with Rayleigh waves, with velocities proportional to the square root of the elastic modulus greater than 2-40 kPa in homogeneous tissue phantoms. In two-layer phantoms, the SAW velocity transitions approximately from that of the lower layer to that of the upper layer as frequency is increased in agreement with the theoretical relationship between SAW dispersion and the depth-dependent stiffness profile. We also observed deformation in the propagation direction of SAWs above a stiff inclusion placed 8 mm below the surface. These findings demonstrate the potential for quantitative digital holography-based elastography of soft tissues as a noninvasive method for disease detection. PMID:22112110

  18. Holography: A survey

    NASA Technical Reports Server (NTRS)

    Dudley, D. D.

    1973-01-01

    The development of holography and the state of the art in recording and displaying information, microscopy, motion, pictures, and television applications are discussed. In addition to optical holography, information is presented on microwave, acoustic, ultrasonic, and seismic holography. Other subjects include data processing, data storage, pattern recognition, and computer-generated holography. Diagrams of holographic installations are provided. Photographs of typical holographic applications are used to support the theoretical aspects.

  19. Shape and 3D acoustically induced vibrations of the human eardrum characterized by digital holography

    NASA Astrophysics Data System (ADS)

    Khaleghi, Morteza; Furlong, Cosme; Cheng, Jeffrey Tao; Rosowski, John J.

    2014-07-01

    The eardrum or Tympanic Membrane (TM) transfers acoustic energy from the ear canal (at the external ear) into mechanical motions of the ossicles (at the middle ear). The acousto-mechanical-transformer behavior of the TM is determined by its shape and mechanical properties. For a better understanding of hearing mysteries, full-field-of-view techniques are required to quantify shape, nanometer-scale sound-induced displacement, and mechanical properties of the TM in 3D. In this paper, full-field-of-view, three-dimensional shape and sound-induced displacement of the surface of the TM are obtained by the methods of multiple wavelengths and multiple sensitivity vectors with lensless digital holography. Using our developed digital holographic systems, unique 3D information such as, shape (with micrometer resolution), 3D acoustically-induced displacement (with nanometer resolution), full strain tensor (with nano-strain resolution), 3D phase of motion, and 3D directional cosines of the displacement vectors can be obtained in full-field-ofview with a spatial resolution of about 3 million points on the surface of the TM and a temporal resolution of 15 Hz.

  20. EVALUATION OF ACOUSTICAL HOLOGRAPHY FOR THE INSPECTION OF LIGHT WATER REACTOR WELD ASSEMBLIES

    SciTech Connect

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

    1982-06-01

    The primary objective of this program was the evaluation of acoustical holography techniques for characterization of the light water reactor weld surface signatures in the nuclear safeguards program. The accurate characterization of weld surface irregulari ties and vertical deviations was achieved using acoustical holographic interferometric techniques. Preselected weld surfaces were inspected and the vertical deviations characterized by phase measurements or fringe densities in the image. Experimental results on Sandia samples verify depth deviation sensitivities of 0.11 {micro}m to 0.16 {micro}m. The two point interferogram technique is recommended for surveillance of the weld surface associated wi th fuel rod removal in the nuclear safeguard program. The use of this unique holographic signal processing provides essentially a fail-safe method for surveillance of clandestine fuel rod removal. Statistical analysis indicates 99.99% (weld surface deviation) confidence interval between 2~m and 3~m can be achieved. These results illustrate the extremely high resolution capabilities of the surveillance technique employing coherent signal processing.

  1. Quantitative measurement of ultrasound pressure field by optical phase contrast method and acoustic holography

    NASA Astrophysics Data System (ADS)

    Oyama, Seiji; Yasuda, Jun; Hanayama, Hiroki; Yoshizawa, Shin; Umemura, Shin-ichiro

    2016-07-01

    A fast and accurate measurement of an ultrasound field with various exposure sequences is necessary to ensure the efficacy and safety of various ultrasound applications in medicine. The most common method used to measure an ultrasound pressure field, that is, hydrophone scanning, requires a long scanning time and potentially disturbs the field. This may limit the efficiency of developing applications of ultrasound. In this study, an optical phase contrast method enabling fast and noninterfering measurements is proposed. In this method, the modulated phase of light caused by the focused ultrasound pressure field is measured. Then, a computed tomography (CT) algorithm used to quantitatively reconstruct a three-dimensional (3D) pressure field is applied. For a high-intensity focused ultrasound field, a new approach that combines the optical phase contrast method and acoustic holography was attempted. First, the optical measurement of focused ultrasound was rapidly performed over the field near a transducer. Second, the nonlinear propagation of the measured ultrasound was simulated. The result of the new approach agreed well with that of the measurement using a hydrophone and was improved from that of the phase contrast method alone with phase unwrapping.

  2. Improved source reconstruction in Fourier-based Near-field Acoustic Holography applied to small apertures

    NASA Astrophysics Data System (ADS)

    Lopez Arteaga, I.; Scholte, R.; Nijmeijer, H.

    2012-10-01

    It is well known that Fourier-based Near-field Acoustic Holography fails to produce good source reconstructions when the aperture size of the microphone array is smaller than the source size. In this paper this problem is overcome by pre-conditioning the spatial hologram data using Linear Predictive Border Padding (LPBP) before it is Fourier-transformed to the wave-number domain. It is shown that LPBP allows for very small aperture sizes with a good reconstruction accuracy. An exhaustive analysis of LPBP is presented based on numerical experiments and measured data. The numerical experiments are performed on two different source types: modal patterns and point sources. These two types of sources represent the two limit situations that one can find in practice: modal patterns have a tonal spectrum in the spatial wave-number domain and are relatively easy to reconstruct accurately, while point sources have a broad-band wave-number spectrum which makes them very challenging to reconstruct. In order to illustrate the accuracy of the method in practice, results of measurements on a hard disk drive are presented as well. For a given distance to the source, the position and size of the hologram plane apertures is varied and the reconstructed source information is compared to the original source data. The reconstructed sources are compared both qualitatively and quantitatively. The results show that LPBP is an efficient and accurate extrapolation method, which leads to accurate reconstructions even for very small aperture sizes.

  3. Evaluation of real-time acoustical holography for breast imaging and biopsy guidance

    NASA Astrophysics Data System (ADS)

    Lehman, Constance D.; Andre, Michael P.; Fecht, Barbara A.; Johansen, Jennifer M.; Shelby, Ronald L.; Shelby, Jerod O.

    1999-05-01

    Ultrasound is an attractive modality for adjunctive characterization of certain breast lesions, but it is not considered specific for cancer and it is not recommended for screening. An imaging technique remarkably different from pulse-echo ultrasound, termed Optical SonographyTM (Advanced Diagnostics, Inc.), uses the through-transmission signal. The method was applied to breast examinations in 41 asymptomatic and symptomatic women ranging in age from 18 to 83 years to evaluate this imaging modality for detection and characterization of breast disease and normal tissue. This approach uses coherent sound and coherent light to produce real-time, large field-of-view images with pronounced edge definition in soft tissues of the body. The system patient interface was modified to improve coupling to the breast and bring the chest wall to within 3 cm of the sound beam. System resolution (full width half maximum of the line-spread function) was 0.5 mm for a swept-frequency beam centered at 2.7 MHz. Resolution degrades slightly in the periphery of the very large 15.2-cm field of view. Dynamic range of the reconstructed 'raw' images (no post processing) was 3000:1. Included in the study population were women with dense parenchyma, palpable ductal carcinoma in situ with negative mammography, superficial and deep fibroadenomas, and calcifications. Successful breast imaging was performed in 40 of 41 women. These images were then compared with images generated using conventional X-ray mammography and pulse-echo ultrasound. Margins of lesions and internal textures were particularly well defined and provided substantial contrast to fatty and dense parenchyma. In two malignant lesions, Optical SonographyTM appeared to approximate more closely tumor extent compared to mammography than pulse-echo sonography. These preliminary studies indicate the method has unique potential for detecting, differentiating, and guiding the biopsy of breast lesions using real-time acoustical holography.

  4. On the applicability of the spherical wave expansion with a single origin for near-field acoustical holography.

    PubMed

    Gomes, Jesper; Hald, Jorgen; Juhl, Peter; Jacobsen, Finn

    2009-03-01

    The spherical wave expansion with a single origin is sometimes used in connection with near-field acoustical holography to determine the sound field on the surface of a source. The radiated field is approximated by a truncated expansion, and the expansion coefficients are determined by matching the sound field model to the measured pressure close to the source. This problem is ill posed, and therefore regularization is required. The present paper investigates the consequence of using only the expansion truncation as regularization approach and compares it with results obtained when additional regularization (the truncated singular value decomposition) is introduced. Important differences between applying the method when using a microphone array surrounding the source completely and an array covering only a part of the source are described. Another relevant issue is the scaling of the wave functions. It is shown that it is important for the additional regularization to work properly that the wave functions are scaled in such a way that their magnitude on the measurement surface decreases with the order. Finally, the method is applied on nonspherical sources using a vibrating plate in both simulations and an experiment, and the performance is compared with the equivalent source method. PMID:19275311

  5. Violin f-hole contribution to far-field radiation via patch near-field acoustical holography.

    PubMed

    Bissinger, George; Williams, Earl G; Valdivia, Nicolas

    2007-06-01

    The violin radiates either from dual ports (f-holes) or via surface motion of the corpus (top+ribs+back), with no clear delineation between these sources. Combining "patch" near-field acoustical holography over just the f-hole region of a violin with far-field radiativity measurements over a sphere, it was possible to separate f-hole from surface motion contributions to the total radiation of the corpus below 2.6 kHz. A0, the Helmholtz-like lowest cavity resonance, radiated essentially entirely through the f-holes as expected while A1, the first longitudinal cavity mode with a node at the f-holes, had no significant f-hole radiation. The observed A1 radiation comes from an indirect radiation mechanism, induced corpus motion approximately mirroring the cavity pressure profile seen for violinlike bowed string instruments across a wide range of sizes. The first estimates of the fraction of radiation from the f-holes F(f) indicate that some low frequency corpus modes thought to radiate only via surface motion (notably the first corpus bending modes) had significant radiation through the f-holes, in agreement with net volume changes estimated from experimental modal analysis. F(f) generally trended lower with increasing frequency, following corpus mobility decreases. The f-hole directivity (top/back radiativity ratio) was generally higher than whole-violin directivity. PMID:17552736

  6. The Effects of Nonlinear Propagation on Acoustic Source Imaging in One-Dimension

    NASA Astrophysics Data System (ADS)

    Shepherd, Micah; Gee, Kent L.

    2006-10-01

    The acoustics of finite-amplitude (nonlinear) sound sources, such as rockets and jets, are not well understood. Characterization of sound pressure amplitudes, aeroacoustic source locations and frequency dependence of these sources is needed to assess the impact of the acoustic field on the launch equipment and surrounding environment. Nonlinear propagation of high-amplitude sound is being studied to determine if a source-imaging method called near-field acoustical holography (NAH), which is based on linear assumptions, can be used to estimate the source information mentioned. A one-dimensional numerical algorithm is being used to linearly and nonlinearly propagate the radiation from a monofrequency source. NAH is used to reconstruct the source information from the simulated data and the error is determined in decibels.

  7. Characterization of a Multi-element Clinical HIFU System Using Acoustic Holography and Nonlinear Modeling

    PubMed Central

    Kreider, Wayne; Yuldashev, Petr V.; Sapozhnikov, Oleg A.; Farr, Navid; Partanen, Ari; Bailey, Michael R.; Khokhlova, Vera A.

    2014-01-01

    High-intensity focused ultrasound (HIFU) is a treatment modality that relies on the delivery of acoustic energy to remote tissue sites to induce thermal and/or mechanical tissue ablation. To ensure the safety and efficacy of this medical technology, standard approaches are needed for accurately characterizing the acoustic pressures generated by clinical ultrasound sources under operating conditions. Characterization of HIFU fields is complicated by nonlinear wave propagation and the complexity of phased-array transducers. Previous work has described aspects of an approach that combines measurements and modeling, and here we demonstrate this approach for a clinical phased array transducer. First, low-amplitude hydrophone measurements were performed in water over a scan plane between the array and the focus. Second, these measurements were used to holographically reconstruct the surface vibrations of the transducer and to set a boundary condition for a 3-D acoustic propagation model. Finally, nonlinear simulations of the acoustic field were carried out over a range of source power levels. Simulation results were compared to pressure waveforms measured directly by hydrophone at both low and high power levels, demonstrating that details of the acoustic field including shock formation are quantitatively predicted. PMID:25004539

  8. GEN-HELS: Improving the efficiency of the CRAFT acoustic holography algorithm via an alternative approach to formulation of the complete general solution to the Helmholtz equation

    NASA Astrophysics Data System (ADS)

    Chapman, Alexander Lloyd

    Recently, a sound source identification technique called CRAFT was developed as an advance in the state of the art in inverse noise problems. It addressed some limitations associated with nearfield acoustic holography and a few of the issues with inverse boundary element method. This work centers on two critical issues associated with the CRAFT algorithm. Although CRAFT employs the complete general solution associated with the Helmholtz equation, the approach taken to derive those equations results in computational inefficiency when implemented numerically. In this work, a mathematical approach to derivation of the basis equations results in a doubling in efficiency. This formulation of CRAFT is termed general Helmholtz equation, least-squares method (GEN-HELS). Additionally, the numerous singular points present in the gradient of the basis functions are shown here to resolve to finite limits. As a realistic test case, a diesel engine surface pressure and velocity are reconstructed to show the increase in efficiency from CRAFT to GEN-HELS. Keywords: Inverse Numerical Acoustics, Acoustic Holography, Helmholtz Equation, HELS Method, CRAFT Algorithm.

  9. Visualized measurement of the acoustic levitation field based on digital holography with phase multiplication

    NASA Astrophysics Data System (ADS)

    Zheng, Puchao; Li, Enpu; Zhao, Jianlin; Di, Jianglei; Zhou, Wangmin; Wang, Hao; Zhang, Ruifeng

    2009-11-01

    By using digital holographic interferometory with phase multiplication, the visualized measurement of the acoustic levitation field (ALF) with single axis is carried out. The digital holograms of the ALF under different conditions are recorded by use of CCD. The corresponding digital holographic interferograms reflecting the sound pressure distribution and the interference phase distribution are obtained by numerical reconstruction and phase subtraction, which are consistent with the theoretical results. It indicates that the proposed digital holographic interferometory with phase multiplication can successfully double the fringe number of the interference phase patterns of the ALF and improve the measurement precision. Compared with the conventional optical holographic interferometory, digital holographic interferometory has the merits of quasi real-time, more exactitude and convenient operation, and it provides an effective way for studying the sound pressure distribution of the ALF.

  10. Reconstruction of transient acoustic radiation from a sphere.

    PubMed

    Wu, Sean F; Lu, Huancai; Bajwa, Manjit S

    2005-04-01

    Transient near-field acoustical holography (NAH) formulation is derived from the Helmholtz equation least squares (HELS) method to reconstruct acoustic radiation from a spherical surface subject to transient excitations in a free field. To facilitate derivations of temporal solutions, we make use of the Laplace transform and expansion in terms of the spherical Hankel functions and spherical harmonics, with their coefficients settled by solving a system of equations obtained by matching an assumed-form solution to the measured acoustic pressure. To derive a general form of solution for a temporal kernel, we replace the spherical Hankel functions and their derivatives by polynomials, recast infinite integrals in the inverse Laplace transform as contour integrals in a complex s-plane, and evaluate it via the residue theorem. The transient acoustic quantities anywhere including the source surface are then obtained by convoluting the temporal kernels with respect to the measured acoustic pressure. Numerical examples of reconstructing transient acoustic fields from explosively expanding, impulsively accelerating, and partially accelerating spheres, and that from a sphere subject to an arbitrarily time-dependent excitation are depicted. To illustrate the effectiveness of HELS-based transient NAH formulations, all input data are collected along an arbitrarily selected line segment and used to reconstruct transient acoustic quantities everywhere. PMID:15898648

  11. Analyzing panel acoustic contributions toward the sound field inside the passenger compartment of a full-size automobile.

    PubMed

    Wu, Sean F; Moondra, Manmohan; Beniwal, Ravi

    2015-04-01

    The Helmholtz equation least squares (HELS)-based nearfield acoustical holography (NAH) is utilized to analyze panel acoustic contributions toward the acoustic field inside the interior region of an automobile. Specifically, the acoustic power flows from individual panels are reconstructed, and relative contributions to sound pressure level and spectrum at any point of interest are calculated. Results demonstrate that by correlating the acoustic power flows from individual panels to the field acoustic pressure, one can correctly locate the panel allowing the most acoustic energy transmission into the vehicle interior. The panel on which the surface acoustic pressure amplitude is the highest should not be used as indicative of the panel responsible for the sound field in the vehicle passenger compartment. Another significant advantage of this HELS-based NAH is that measurements of the input data only need to be taken once by using a conformal array of microphones in the near field, and ranking of panel acoustic contributions to any field point can be readily performed. The transfer functions between individual panels of any vibrating structure to the acoustic pressure anywhere in space are calculated not measured, thus significantly reducing the time and effort involved in panel acoustic contributions analyses. PMID:25920860

  12. Krylov subspace iterative methods for boundary element method based near-field acoustic holography.

    PubMed

    Valdivia, Nicolas; Williams, Earl G

    2005-02-01

    The reconstruction of the acoustic field for general surfaces is obtained from the solution of a matrix system that results from a boundary integral equation discretized using boundary element methods. The solution to the resultant matrix system is obtained using iterative regularization methods that counteract the effect of noise on the measurements. These methods will not require the calculation of the singular value decomposition, which can be expensive when the matrix system is considerably large. Krylov subspace methods are iterative methods that have the phenomena known as "semi-convergence," i.e., the optimal regularization solution is obtained after a few iterations. If the iteration is not stopped, the method converges to a solution that generally is totally corrupted by errors on the measurements. For these methods the number of iterations play the role of the regularization parameter. We will focus our attention to the study of the regularizing properties from the Krylov subspace methods like conjugate gradients, least squares QR and the recently proposed Hybrid method. A discussion and comparison of the available stopping rules will be included. A vibrating plate is considered as an example to validate our results. PMID:15759691

  13. Noise suppression in curved glass shells using macro-fiber-composite actuators studied by the means of digital holography and acoustic measurements

    NASA Astrophysics Data System (ADS)

    Mokrý, P.; Psota, P.; Steiger, K.; Václavík, J.; Doleček, R.; Lédl, V.; Šulc, M.

    2015-02-01

    The paper presents methods and experimental results of the semi-active control of noise transmission in a curved glass shell with attached piezoelectric macro fiber composite (MFC) actuators. The semi-active noise control is achieved via active elasticity control of piezoelectric actuators by connecting them to an active electric shunt circuit that has a negative effective capacitance. Using this approach, it is possible to suppress the vibration of the glass shell in the normal direction with respect to its surface and to increase the acoustic transmission loss of the piezoelectric MFC-glass composite structure. The effect of the MFC actuators connected to the negative capacitance shunt circuit on the surface distribution of the normal vibration amplitude is studied using frequency-shifted digital holography (FSDH). The principle of the used FSDH method is described in the paper. The frequency dependence of the acoustic transmission loss through the piezoelectric MFC-glass composite structure is estimated using measurements of the specific acoustic impedance of the curved glass shell. The specific acoustic impedance is measured using two microphones and a laser Doppler vibrometer (LDV). The results from the LDV measurements are compared with the FSDH data. The results of the experiments show that using this approach, the acoustic transmission loss in a glass shell can be increased by 36 dB in the frequency range around 247 Hz and by 25 dB in the frequency range around 258 Hz. The experiments indicate that FSDH measurements provide an efficient tool that can be used for fast and accurate measurements of the acoustic transmission loss in large planar structures.

  14. Holography reinvented

    NASA Astrophysics Data System (ADS)

    Benton, Stephen A.

    2002-07-01

    This paper is entitled Holography Reinvented, because its theme is simply that each of the three best-known names in holography made their discoveries and inventions without knowing about the work of any the others; that is, each of them invented or reinvented holography, as it were. This is largely a presentation of anecdotal remarks drawn from conversations, observations drawn from historical documents, including some from the Museum of Holography files now at the MIT Museum, and observations drawn from the author's own experiences as holography has evolved. As such, any errors of fact or interpretation are entirely the author's own, as is the slant toward imaging or display holography that will be conspicuous. The three main players are Professors Denis Gabor, Emmett Leith, and Juri Denisyuk. A few other names will come into the story as well, notably: Pieter van Heerden (my former colleague at the Polaroid Research Labs) and Hussein M.A. El-Sum, among others.

  15. Compressive Holography

    NASA Astrophysics Data System (ADS)

    Lim, Se Hoon

    Compressive holography estimates images from incomplete data by using sparsity priors. Compressive holography combines digital holography and compressive sensing. Digital holography consists of computational image estimation from data captured by an electronic focal plane array. Compressive sensing enables accurate data reconstruction by prior knowledge on desired signal. Computational and optical co-design optimally supports compressive holography in the joint computational and optical domain. This dissertation explores two examples of compressive holography: estimation of 3D tomographic images from 2D data and estimation of images from under sampled apertures. Compressive holography achieves single shot holographic tomography using decompressive inference. In general, 3D image reconstruction suffers from underdetermined measurements with a 2D detector. Specifically, single shot holographic tomography shows the uniqueness problem in the axial direction because the inversion is ill-posed. Compressive sensing alleviates the ill-posed problem by enforcing some sparsity constraints. Holographic tomography is applied for video-rate microscopic imaging and diffuse object imaging. In diffuse object imaging, sparsity priors are not valid in coherent image basis due to speckle. So incoherent image estimation is designed to hold the sparsity in incoherent image basis by support of multiple speckle realizations. High pixel count holography achieves high resolution and wide field-of-view imaging. Coherent aperture synthesis can be one method to increase the aperture size of a detector. Scanning-based synthetic aperture confronts a multivariable global optimization problem due to time-space measurement errors. A hierarchical estimation strategy divides the global problem into multiple local problems with support of computational and optical co-design. Compressive sparse aperture holography can be another method. Compressive sparse sampling collects most of significant field

  16. Acoustic backscattering enhancements for circular elastic plates and acrylic targets, the application of acoustic holography to the study of scattering from planar elastic objects, and other research on the radiation of sound

    NASA Astrophysics Data System (ADS)

    Hefner, Brian Todd

    2000-08-01

    Backscattering enhancements on both circular elastic plates and acrylic targets are investigated as well as several techniques for the study of the radiation of sound. For sound scattered from a circular plate, two backscattering enhancements associated with the extensional wave are observed. The first of these enhancements involves extensional wave excitation along the diameter of the plate. When the extensional wave strikes the plate edge, reflection occurs which produces radiation into the backscattering direction. For those portions of the leaky wave which strike the edge at oblique incidence, there is mode conversion into a trapped shear wave. For certain angles of incidence on the plate edge, this wave can undergo multiple reflections and convert back into a leaky wave directed in the backscattering direction. Each of these enhancements are modeled using quantitative ray methods. Acoustic holography is also used to image the surface motion of the plate to identify the causes of these enhancements and to assess the validity of the ray model. Backscattering enhancements associated with antisymmetric Lamb wave excitation are also investigated. Scattering at the first-order antisymmetric wave coupling angle is studied using acoustic holography. Significant mode- conversion between the zeroth and first-order antisymmetric waves is observed which plays a significant role in the scattering processes. Quantitative ray models were also used to examine the backscattering from acrylic targets. Polymer solids typically have shear and Rayleigh wave phase velocities which are less than the speed of sound in water. For solid acrylic spheres, low frequency resonances are observed both experimentally and in the exact backscattering form functions which are due to coupling between the incident field and the subsonic Rayleigh wave on the sphere. The effects of material absorption, which is generally high in polymers, is examined in both the exact solutions and the quantitative

  17. Testing Helioseismic Holography

    NASA Astrophysics Data System (ADS)

    MacBeth, Jamie

    The recent advent of "helioseismic holography" or "acoustic imaging" as it has sometimes been called, has provided a rich new set of techiniques and phenomena to aid local helioseismology. Through the application of these techniques to SOHO-MDI observations, strange new signatures - the "acoustic moat" and "acoustic glories" - have been documented but difficult to understand (Braun et al. 1998). In addition, by comparing the depth diagnostics between observations and simulations of an active region introducing random noise to a solar atmosphere through the ray approximation, it has been suggested that the refraction or absortion of p-modes in sunspots is primarily superficial. The purpose of this study is to better understand helioseismic holography through more testing. More specifically we propose a normal mode approach to generating artificial datasets. By solving the wave equation on the sphere with a sound speed perturbation resembling an active region, and summing the perturbed eigenfunctions in fourier space with the corresponding eigenfrequencies, we hope to construct an artificial dataset that more closely resembles the real thing. Although thousands of solar p-modes need to be considered, as well as millions (or more) of points in the resulting artificial dataset to be used, we aspire to make this possibly computationally expensive venture practical. With this method we hope to better test the depth, frequency, and pupil size diagnostics of acoustic images. This research is supported by NASA grant NAG5-3077 at Stanford University.

  18. Thermodynamic holography

    PubMed Central

    Wei, Bo-Bo; Jiang, Zhan-Feng; Liu, Ren-Bao

    2015-01-01

    The holographic principle states that the information about a volume of a system is encoded on the boundary surface of the volume. Holography appears in many branches of physics, such as optics, electromagnetism, many-body physics, quantum gravity, and string theory. Here we show that holography is also an underlying principle in thermodynamics, a most important foundation of physics. The thermodynamics of a system is fully determined by its partition function. We prove that the partition function of a finite but arbitrarily large system is an analytic function on the complex plane of physical parameters, and therefore the partition function in a region on the complex plane is uniquely determined by its values along the boundary. The thermodynamic holography has applications in studying thermodynamics of nano-scale systems (such as molecule engines, nano-generators and macromolecules) and provides a new approach to many-body physics. PMID:26478214

  19. Thermodynamic holography.

    PubMed

    Wei, Bo-Bo; Jiang, Zhan-Feng; Liu, Ren-Bao

    2015-01-01

    The holographic principle states that the information about a volume of a system is encoded on the boundary surface of the volume. Holography appears in many branches of physics, such as optics, electromagnetism, many-body physics, quantum gravity, and string theory. Here we show that holography is also an underlying principle in thermodynamics, a most important foundation of physics. The thermodynamics of a system is fully determined by its partition function. We prove that the partition function of a finite but arbitrarily large system is an analytic function on the complex plane of physical parameters, and therefore the partition function in a region on the complex plane is uniquely determined by its values along the boundary. The thermodynamic holography has applications in studying thermodynamics of nano-scale systems (such as molecule engines, nano-generators and macromolecules) and provides a new approach to many-body physics. PMID:26478214

  20. Seismic Holography of Solar Activity

    NASA Technical Reports Server (NTRS)

    Lindsey, Charles

    2000-01-01

    The basic goal of the project was to extend holographic seismic imaging techniques developed under a previous NASA contract, and to incorporate phase diagnostics. Phase-sensitive imaging gives us a powerful probe of local thermal and Doppler perturbations in active region subphotospheres, allowing us to map thermal structure and flows associated with "acoustic moats" and "acoustic glories". These remarkable features were discovered during our work, by applying simple acoustic power holography to active regions. Included in the original project statement was an effort to obtain the first seismic images of active regions on the Sun's far surface.

  1. Dental Holography

    NASA Astrophysics Data System (ADS)

    Dirtoft, Ingegerd

    1983-12-01

    Ten years have passed since the first articles appeared in this new field. The qualities of the laser light together with the need of contactless 3-D measurements for different dental purposes seemed to be extremely promising, but still just a few scientists have used the method and mostly for laboratory studies. For some reason there has been a preponderance for orthodontic measurements. This seems to be a bit peculiar from holographic view compared with measurements for engineering purposes, which usually are made on metals. So naturally holography can become a clinical tool for measurements in the field of fixed bridges, removable partial dentures and implants. One of the problems is that the need for holography in dental research must be fulfilled in collaboration with physicists. Only a two-way communication during an entire experiment can balance both technical and odontological demands and thus give practical and clinical important results. The need for an easy way of handling the evaluation to get all required information is another problem and of course the holographic equipment must be converted to a box easy to handle for everyone. At last the position of dental holography today is going to be carefully examined together with an attempt to look into the hopefully exciting and not to utopic future for this research field.

  2. Single Beam Holography.

    ERIC Educational Resources Information Center

    Chen, Hsuan; Ruterbusch, Paul H.

    1979-01-01

    Discusses how holography can be used as part of undergraduate physics laboratories. The authors propose a single beam technique of holography, which will reduce the recording scheme as well as relax the isolation requirements. (HM)

  3. Incoherent holography

    NASA Astrophysics Data System (ADS)

    Abramson, Nils H.

    2000-10-01

    Dennis Gabor invented in-line holography in 1947, but at that time the coherent light from a laser did not yet exist and therefore the holograms he produced were of very low quality. When the laser was born in 1960 beautiful 3-D off- center holograms were for the first time produced by Emmett Leith and Juris Upatnieks. However, already as early as 1934 the inventor and artist Hans Weil patented a method to produce simple pictures that appeared floating in space, by scratching a transparent or metallic surface in certain directions. In 1995 William J. Beaty published a method for Hand-Drawn Holograms. Then it became possible for any artist to draw his own 3-D pictures of simple objects and using his ingenious techniques these hand drawn images will mimic many of the qualities of ordinary holograms.

  4. Holography and tomography

    SciTech Connect

    Howells, M.

    1997-02-01

    This session includes a collection of outlines of pertinent information, diagrams, graphs, electron micrographs, and color photographs pertaining to historical aspects and recent advances in the development of X-ray Gabor Holography. Many of the photographs feature or pertain to instrumentation used in holography, tomography, and cryo-holography.

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

    PubMed

    Wu, Sean F; Zhou, Pan

    2016-07-01

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

  6. Guest Editoria Holography A Dedication To Dennis Gabor

    NASA Astrophysics Data System (ADS)

    Wyant, James C.; Chen, Chungte T.; Reynolds, George O.

    1980-10-01

    We thought it was time to bring the readers of Optical Engineering up to date on the new developments in holography, as was done exactly five years ago with the September/October 1975 special issue. The seeds for this special issue were sown during the 1978 Gordon Conference on Coherent Optics and Holography held at the Miramar Hotel in Santa Barbara, California. The conference clearly demonstrated, through the discussion of many interesting research and development applications, that holography is alive and well. For example, artists have discovered holography as a new medium and there is a museum for displaying new holographic developments and inventions. In addition to the opening of the New York museum where artists and patrons are thoroughly enjoying holography, the past five years have witnessed the publication of the Handbook of Optical Holography, continuing issues of the Acoustical Holography proceedings, the gathering of scientists to exchange ideas at three Gordon Conferences in 1976, 1978, and 1980, and the SPIE conference on holography held in Los Angeles in February 1980.

  7. Characterization of Transducer Performance and Narrowband Transient Ultrasonic Fields in Metals by Rayleigh-Sommerfeld Backpropagation of Compression Acoustic Waves Measured with Double-Pulsed Tv Holography

    NASA Astrophysics Data System (ADS)

    Trillo, Cristina; Doval, Ángel F.; Fernández, José L.; Rodríguez-Gómez, Pablo; López-Vázquez, J. Carlos

    2014-10-01

    This article presents a method aimed at the characterization of the narrowband transient acoustic field radiated by an ultrasonic plane transducer into a homogeneous, isotropic and optically opaque prismatic solid, and the assessment of the performance of the acoustic source. The method relies on a previous technique based on the full-field optical measurement of an acoustic wavepacket at the surface of a solid and its subsequent numerical backpropagation within the material. The experimental results show that quantitative transversal and axial profiles of the complex amplitude of the beam can be obtained at any plane between the measurement and excitation surfaces. The reconstruction of the acoustic field at the transducer face, carried out on a defective transducer model, shows that the method could also be suitable for the nondestructive testing of the performance of ultrasonic sources. In all cases, the measurements were performed with the transducer working under realistic loading conditions.

  8. Artistic Representation with Pulsed Holography

    NASA Astrophysics Data System (ADS)

    Ishii, S.

    2013-02-01

    This thesis describes artistic representation through pulsed holography. One of the prevalent practical problems in making holograms is object movement. Any movement of the object or film, including movement caused by acoustic vibration, has the same fatal results. One way of reducing the chance of movement is by ensuring that the exposure is very quick; using a pulsed laser can fulfill this objective. The attractiveness of using pulsed laser is based on the variety of materials or objects that can be recorded (e.g., liquid material or instantaneous scene of a moving object). One of the most interesting points about pulsed holograms is that some reconstructed images present us with completely different views of the real world. For example, the holographic image of liquid material does not appear fluid; it looks like a piece of hard glass that would produce a sharp sound upon tapping. In everyday life, we are unfamiliar with such an instantaneous scene. On the other hand, soft-textured materials such as a feather or wool differ from liquids when observed through holography. Using a pulsed hologram, we can sense the soft touch of the object or material with the help of realistic three-dimensional (3-D) images. The images allow us to realize the sense of touch in a way that resembles touching real objects. I had the opportunity to use a pulsed ruby laser soon after I started to work in the field of holography in 1979. Since then, I have made pulsed holograms of activities, including pouring water, breaking eggs, blowing soap bubbles, and scattering feathers and popcorn. I have also created holographic art with materials and objects, such as silk fiber, fabric, balloons, glass, flowers, and even the human body. Whenever I create art, I like to present the spectator with a new experience in perception. Therefore, I would like to introduce my experimental artwork through those pulsed holograms.

  9. Acoustics

    NASA Astrophysics Data System (ADS)

    The acoustics research activities of the DLR fluid-mechanics department (Forschungsbereich Stroemungsmechanik) during 1988 are surveyed and illustrated with extensive diagrams, drawings, graphs, and photographs. Particular attention is given to studies of helicopter rotor noise (high-speed impulsive noise, blade/vortex interaction noise, and main/tail-rotor interaction noise), propeller noise (temperature, angle-of-attack, and nonuniform-flow effects), noise certification, and industrial acoustics (road-vehicle flow noise and airport noise-control installations).

  10. Acoustics

    NASA Technical Reports Server (NTRS)

    Goodman, Jerry R.; Grosveld, Ferdinand

    2007-01-01

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

  11. An Introduction to Educational Holography.

    ERIC Educational Resources Information Center

    Lloyd, R. Scott

    Holograms are capable of taking the two-dimensional ways of envisioning information to another dimension of presentation, representation, and conceptualization. Educational holography is joining display holography, holographic testing of materials, and holographic optical elements as a fourth major field in holography. Holograms are explored as…

  12. Holography In Biomedical Sciences

    NASA Astrophysics Data System (ADS)

    von Bally, G.

    1988-01-01

    Today not only physicists and engineers but also biological and medical scientists are exploring the potentials of holographic methods in their special field of work. Most of the underlying physical principles such as coherence, interference, diffraction and polarization as well as general features of holography e.g. storage and retrieval of amplitude and phase of a wavefront, 3-d-imaging, large field of depth, redundant storage of information, spatial filtering, high-resolving, non-contactive, 3-d form and motion analysis are explained in detail in other contributions to this book. Therefore, this article is confined to the applications of holography in biomedical sciences. Because of the great number of contributions and the variety of applications [1,2,3,4,5,6,7,8] in this review the investigations can only be mentioned briefly and the survey has to be confined to some examples. As in all fields of optics and laser metrology, a review of biomedical applications of holography would be incomplete if military developments and their utilization are not mentioned. As will be demonstrated by selected examples the increasing interlacing of science with the military does not stop at domains that traditionally are regarded as exclusively oriented to human welfare like biomedical research [9]. This fact is actually characterized and stressed by the expression "Star Wars Medicine", which becomes increasingly common as popular description for laser applications (including holography) in medicine [10]. Thus, the consequence - even in such highly specialized fields like biomedical applications of holography - have to be discussed.

  13. Development of supersonic intensity in reverberant environments (sire) with applications in underwater acoustics

    NASA Astrophysics Data System (ADS)

    Barnard, Andrew R.

    A new measurement technique, Supersonic Intensity in Reverberant Environments (SIRE), has been developed analytically, and validated numerically and experimentally. The SIRE technique permits the measurement of narrowband radiated sound power and directivity in an environment with unknown field conditions. This type of measurement has previously been limited to environments with exact field conditions, such as the free field. Due to long acoustic wavelengths, underwater anechoic tanks are not cost-effective for low frequency measurements, nor are at-sea measurements time- or cost-effective. Unlike SIRE, techniques like nearfield acoustic holography (NAH) rely on knowledge of exact field conditions, which are usually unknown in a realistic measurement environment. SIRE is a cost effective, repeatable laboratory technique for narrowband evaluation of complex structural acoustic sources submerged in water. The technique leverages underwater acoustic intensity vector sensors in the near field of a source and allows the outgoing acoustic waves to be separated from unwanted incoming acoustic waves. Supersonic wavenumber filtering rejects the evanescent potions of the acoustic pressure and particle velocity from the separated, outward-propagating sound pressure and particle velocity. The SIRE technique was applied to a monopole source, dipole source, and point-driven, thin-walled cylinder with massive end caps. All sources were placed in an underwater reverberant tank and measured using custom underwater vector sensors specifically designed and built to reduce electromagnetic interference (EMI). The results are compared with theory, the ANSI S12.51 standard one-third-octave reverberation room method, and free field NAH. SIRE is shown to accurately measure radiated sound power to within the limits of ANSI S12.51. SIRE is also shown to accurately measure the directivity indices of simple sources to within +/-3 dB. Finally, a coupled finite element/boundary element (FE

  14. Holography and Optical Storage

    NASA Astrophysics Data System (ADS)

    Imlau, Mirco; Fally, Martin; Coufal, Hans; Burr, Geoffrey; Sincerbox, Glenn

    The term holography is composed of the Greek words holos (= whole) and graphein (= to record, to write), and thus summarizes the key aspects of its underlying principle: recording the complete wavefront of an object, i.e., its intensity as well as its phase. Interference and diffraction phenomena are employed to record and retrieve the full information, a technique pioneered by Dennis Gabor in 1948. He was honored with the Nobel prize in Physics in 1971, reflecting the general impact of holography on modern physics.

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

    NASA Technical Reports Server (NTRS)

    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.

  16. Holography without Fuss.

    ERIC Educational Resources Information Center

    Davies, Steve

    1989-01-01

    Outlines what a hologram is, the main types of holography, and how a simple system producing a white light reflection hologram can be set up in a school physics laboratory. Discusses the basic optics of the hologram and procedures and materials for making holograms in school. (YP)

  17. Photon counting digital holography

    NASA Astrophysics Data System (ADS)

    Demoli, Nazif; Skenderović, Hrvoje; Stipčević, Mario; Pavičić, Mladen

    2016-05-01

    Digital holography uses electronic sensors for hologram recording and numerical method for hologram reconstruction enabling thus the development of advanced holography applications. However, in some cases, the useful information is concealed in a very wide dynamic range of illumination intensities and successful recording requires an appropriate dynamic range of the sensor. An effective solution to this problem is the use of a photon-counting detector. Such detectors possess counting rates of the order of tens to hundreds of millions counts per second, but conditions of recording holograms have to be investigated in greater detail. Here, we summarize our main findings on this problem. First, conditions for optimum recording of digital holograms for detecting a signal significantly below detector's noise are analyzed in terms of the most important holographic measures. Second, for time-averaged digital holograms, optimum recordings were investigated for exposures shorter than the vibration cycle. In both cases, these conditions are studied by simulations and experiments.

  18. Holography: science and art

    NASA Astrophysics Data System (ADS)

    Boone, Pierre M.

    1998-09-01

    Art and science are separated by a very large distance nowadays. Long ago, e.g. in Renaissance, or even earlier, in classic Greece and Rome, or still earlier in Egypt or Mesopotamia, arts and sciences were united. Today they seem to go separate paths: science for the industry, arts for the gallery. Holography is an exception: no art without science, but also no science without art.

  19. Holography in Hong Kong

    NASA Astrophysics Data System (ADS)

    Leung, Kang M.

    1995-02-01

    Before 1984, to a westerner Hong Kong was hardly a recognizable dot on a world atlas. It is a Chinese city and a British colony. At midnight on 30 June 1997, Britain will end its century and a half of colonial rule in Hong Kong, leaving China to resume sovereignty over its six million people. Since 1990, in the stress of this crisis Hong Kong prospers at a time of global recession. This also creates many opportunities in higher education among the youngsters. The success of the city attracts, at least 12% of persons who emigrated in the 10 years before 1992 have returned to Hong Kong. This dramatic change brings in unexpected new information and high technologies to the city. Holography is one of these new technologies. It was rarely understood by the general population before the 1980s. But with the scattered efforts of some research workers from the academic and commercial groups along with the prosperity of the city, the subject of holography has become increasingly popular. This report gives a quick survey on the major activities of holography in Hong Kong.

  20. Medical applications of holography

    NASA Astrophysics Data System (ADS)

    von Bally, Gert

    1991-11-01

    From the various capabilities of holography for image processing and measuring purposes, holographic interferometric techniques have found more extended application in biological and medical research. Due to their special properties the different methods of holographic interferometry are applied to characteristic fields of biomedical investigations where--similar to nondestructive testing--vibration and deformation analysis is of interest. Features of holographic interferometry, such as the possibility of noncontactive, three-dimensional investigations with a large field-of-depth, are used with advantage. The main applications can be found in basic research e.g., in audiology, dentistry, opthalmology, and experimental orthopedics. Because of the great number of investigations and the variety of medical domains in which these investigations were performed this survey is confined to some characteristic examples. As in all fields of optics and laser metrology, a review on biomedical applications of holography would be incomplete if military developments and utilization were not mentioned. As demonstrated by selected examples, the increasing interlacing of science with the military does not stop at domains that traditionally are regarded as exclusively oriented to human welfare--like biomedical research. The term ''Star Wars Medicine'', which becomes an increasingly popular expression for laser applications (including holography) in medicine, characterizes the consequences of this development.

  1. Holography in the Junior High.

    ERIC Educational Resources Information Center

    Tomaszkiewicz, Frank

    1988-01-01

    Examines the use of holography in the art technology program of a junior high school. Characterizing holography as a valuable artistic experience and discovery experience and stressing the importance of student interest and involvement, the author discusses the necessary equipment for the project and includes two diagrams of a holographic setup.…

  2. New trend in electron holography

    NASA Astrophysics Data System (ADS)

    Tanigaki, Toshiaki; Harada, Ken; Murakami, Yasukazu; Niitsu, Kodai; Akashi, Tetsuya; Takahashi, Yoshio; Sugawara, Akira; Shindo, Daisuke

    2016-06-01

    Electron holography using a coherent electron wave is a promising technique for high-resolution visualization of electromagnetic fields in and around objects. The capability of electron holography has been enhanced by the development of new technologies and has thus become an even more powerful tool for exploring scientific frontiers. This review introduces these technologies including split-illumination electron holography and vector-field electron tomography. Split-illumination electron holography, which uses separated coherent waves, overcomes the limits imposed by the lateral coherence requirement for electron waves in electron holography. Areas that are difficult to observe using conventional electron holography are now observable. Exemplified applications include observing a singular magnetic domain wall in electrical steel sheets, local magnetizations at anti-phase boundaries, and electrostatic potentials in metal-oxide-semiconductor field-effect transistors. Vector-field electron tomography can be used to visualize magnetic vectors in three dimensions. Two components of the vectors are reconstructed using dual-axis tomography, and the remaining one is calculated using div B   =  0. A high-voltage electron microscope can be used to achieve precise magnetic reconstruction. For example, magnetic vortices have been visualized using a 1 MV holography electron microscope.

  3. Holography gets smart

    NASA Astrophysics Data System (ADS)

    Lowe, Chris; Larbey, Cynthia

    2008-02-01

    At least 6% of world trade, amounting to some 200bn per year, involves counterfeit goods. But this figure would be even higher were it not for the humble hologram. Invented 50 years ago, holograms provide authentication tags to deter copying, and can be found everywhere from credit cards, passports and banknotes to consumer goods, cosmetics and pharmaceuticals. Holography also underpins supermarket scanners and CD players; it can even be used to store optical data in 3D. Now, however, holograms are making their mark as powerful yet cheap diagnostic tools, which could in particular have many applications in biomedicine.

  4. Adaptive Optical Scanning Holography

    PubMed Central

    Tsang, P. W. M.; Poon, Ting-Chung; Liu, J.-P.

    2016-01-01

    Optical Scanning Holography (OSH) is a powerful technique that employs a single-pixel sensor and a row-by-row scanning mechanism to capture the hologram of a wide-view, three-dimensional object. However, the time required to acquire a hologram with OSH is rather lengthy. In this paper, we propose an enhanced framework, which is referred to as Adaptive OSH (AOSH), to shorten the holographic recording process. We have demonstrated that the AOSH method is capable of decreasing the acquisition time by up to an order of magnitude, while preserving the content of the hologram favorably. PMID:26916866

  5. Adaptive Optical Scanning Holography.

    PubMed

    Tsang, P W M; Poon, Ting-Chung; Liu, J-P

    2016-01-01

    Optical Scanning Holography (OSH) is a powerful technique that employs a single-pixel sensor and a row-by-row scanning mechanism to capture the hologram of a wide-view, three-dimensional object. However, the time required to acquire a hologram with OSH is rather lengthy. In this paper, we propose an enhanced framework, which is referred to as Adaptive OSH (AOSH), to shorten the holographic recording process. We have demonstrated that the AOSH method is capable of decreasing the acquisition time by up to an order of magnitude, while preserving the content of the hologram favorably. PMID:26916866

  6. DSN Microwave Antenna Holography

    NASA Technical Reports Server (NTRS)

    Rochblatt, D. J.; Seidel, B. L.

    1984-01-01

    The DSN microwave antenna holography project will obtain three-dimensional pictures of the large DSN antenna surfaces. These pictures must be of suffi icient resolution to allow adjustment of the reflector panels to an rms surface of 0.5 mm (0.25 mm, goal). The major parameters and equations needed to define a holographic measurement system are outlined and then the proof of concept demonstration measurement that was made at DSS-43 (Australia) that resulted in contour maps with spatial resolution of 7 m in the aperture plane and resolution orthogonal to the aperture plane of 0.7 mm was discussed.

  7. Split-illumination electron holography

    SciTech Connect

    Tanigaki, Toshiaki; Aizawa, Shinji; Suzuki, Takahiro; Park, Hyun Soon; Inada, Yoshikatsu; Matsuda, Tsuyoshi; Taniyama, Akira; Shindo, Daisuke; Tonomura, Akira

    2012-07-23

    We developed a split-illumination electron holography that uses an electron biprism in the illuminating system and two biprisms (applicable to one biprism) in the imaging system, enabling holographic interference micrographs of regions far from the sample edge to be obtained. Using a condenser biprism, we split an electron wave into two coherent electron waves: one wave is to illuminate an observation area far from the sample edge in the sample plane and the other wave to pass through a vacuum space outside the sample. The split-illumination holography has the potential to greatly expand the breadth of applications of electron holography.

  8. Tailoring ultrasonic beams with optoacoustic holography

    NASA Astrophysics Data System (ADS)

    Meyer, Alex; Gspan, Stefan J.; Bernet, Stefan; Ritsch-Marte, Monika

    2003-06-01

    A combination of laser-induced ultrasound generation and ultrasonic holography for spatial control of the generated ultrasonic pulse is presented. Ultrasound is produced by absorption of laser pulses at an absorbing layer in a water tank via the optoacoustic effect. In order to produce a defined ultrasonic frequency in the MHz range, the laser pulses are harmonically time-modulated using an acousto-optic modulator (AOM). Additionally, the laser intensity is spatially controlled. This is realized with a high resolution liquid crystal spatial light modulator (LCD). A computer generated pattern is displayed at the LCD and projected by the expanded laser beam to an absorptive layer in the water tank. As a result, the emitted ultrasonic wave emerges in a predetermined way, which is an acoustical analogue to the effect of a "diffractive optical element" in laser optics. The flexible method of optical ultrasound generation and diffractive steering promises new applications in medical and technical ultrasound diagnostics.

  9. When is holography consistent?

    NASA Astrophysics Data System (ADS)

    McInnes, Brett; Ong, Yen Chin

    2015-09-01

    Holographic duality relates two radically different kinds of theory: one with gravity, one without. The very existence of such an equivalence imposes strong consistency conditions which are, in the nature of the case, hard to satisfy. Recently a particularly deep condition of this kind, relating the minimum of a probe brane action to a gravitational bulk action (in a Euclidean formulation), has been recognized; and the question arises as to the circumstances under which it, and its Lorentzian counterpart, is satisfied. We discuss the fact that there are physically interesting situations in which one or both versions might, in principle, not be satisfied. These arise in two distinct circumstances: first, when the bulk is not an Einstein manifold and, second, in the presence of angular momentum. Focusing on the application of holography to the quark-gluon plasma (of the various forms arising in the early Universe and in heavy-ion collisions), we find that these potential violations never actually occur. This suggests that the consistency condition is a "law of physics" expressing a particular aspect of holography.

  10. Atomic resolution holography.

    PubMed

    Hayashi, Kouichi

    2014-11-01

    Atomic resolution holography, such as X-ray fluorescence holography (XFH)[1] and photoelectron holography (PH), has the attention of researcher as an informative local structure analysis, because it provides three dimensional atomic images around specific elements within a range of a few nanometers. It can determine atomic arrangements around a specific element without any prior knowledge of structures. It is considered that the atomic resolution holographic is a third method of structural analysis at the atomic level after X-ray diffraction (XRD) and X-ray absorption fine structure (XAFS). As known by many researchers, XRD and XAFS are established methods that are widespread use in various fields. XRD and XAFS provide information on long-range translational periodicities and very local environments, respectively, whereas the atomic resolution holography gives 3D information on the local order and can visualize surrounding atoms with a large range of coordination shells. We call this feature "3D medium-range local structure observation".In addition to this feature, the atomic resolution holography is very sensitive to the displacement of atoms from their ideal positions, and one can obtain quantitative information about local lattice distortions by analyzing reconstructed atomic images[2] When dopants with different atomic radii from the matrix elements are present, the lattices around the dopants are distorted. However, using the conventional methods of structural analysis, one cannot determine the extent to which the local lattice distortions are preserved from the dopants. XFH is a good tool for solving this problem.Figure 1 shows a recent achievement on a relaxor ferroelectric of Pb(Mg1/3Nb2/3)O3 (PMN) using XFH. The structural studies of relaxor ferroelectrics have been carried out by X-ray or neutron diffractions, which suggested rhombohedral distortions of their lattices. However, their true pictures have not been obtained, yet. The Nb Kα holograms showed

  11. Holography Experiments on Optical Imaging.

    ERIC Educational Resources Information Center

    Bonczak, B.; Dabrowski, J.

    1979-01-01

    Describes experiments intended to produce a better understanding of the holographic method of producing images and optical imaging by other optical systems. Application of holography to teaching physics courses is considered. (Author/SA)

  12. Microwave antenna holography

    NASA Technical Reports Server (NTRS)

    Rochblatt, David J.; Seidel, Boris L.

    1992-01-01

    This microwave holography technique utilizes the Fourier transform relation between the complex far field radiation pattern of an antenna and the complex aperture field distribution. Resulting aperture phase and amplitude distribution data can be used to precisely characterize various crucial performance parameters, including panel alignment, panel shaping, subreflector position, antenna aperture illumination, directivity at various frequencies, and gravity deformation effects. The methodology of data processing presented here was successfully applied to the Deep Space Network (DSN) 34-m beam waveguide antennas. The antenna performance was improved at all operating frequencies by reducing the main reflector mechanical surface rms error to 0.43 mm. At Ka-band (32 GHz), the estimated improvement is 4.1 dB, resulting in an aperture efficiency of 52 percent. The performance improvement was verified by efficiency measurements and additional holographic measurements.

  13. Higher Spin Holography

    NASA Astrophysics Data System (ADS)

    Chang, Chi-Ming

    This dissertation splits into two distinct halves. The first half is devoted to the study of the holography of higher spin gauge theory in AdS 3. We present a conjecture that the holographic dual of W N minimal model in a 't Hooft-like large N limit is an unusual "semi-local" higher spin gauge theory on AdS3 x 1. At each point on the S1 lives a copy of three-dimensional Vasiliev theory, that contains an infinite tower of higher spin gauge fields coupled to a single massive complex scalar propagating in AdS3. The Vasiliev theories at different points on the S1 are correlated only through the AdS3 boundary conditions on the massive scalars. All but one single tower of higher spin symmetries are broken by the boundary conditions. This conjecture is checked by comparing tree-level two- and three-point functions, and also one-loop partition functions on both side of the duality. The second half focuses on the holography of higher spin gauge theory in AdS 4. We demonstrate that a supersymmetric and parity violating version of Vasiliev's higher spin gauge theory in AdS4 admits boundary conditions that preserve N = 0,1,2,3,4 or 6 supersymmetries. In particular, we argue that the Vasiliev theory with U( M) Chan-Paton and N = 6 boundary condition is holographically dual to the 2+1 dimensional U(N) k x U(M) -k ABJ theory in the limit of large N, k and finite M. In this system all bulk higher spin fields transform in the adjoint of the U(M) gauge group, whose bulk t'Hooft coupling is M/N. Our picture suggests that the supersymmetric Vasiliev theory can be obtained as a limit of type IIA string theory in AdS4 x CP3, and that the non-Abelian Vasiliev theory at strong bulk 't Hooft coupling smoothly turn into a string field theory. The fundamental string is a singlet bound state of Vasiliev's higher spin particles held together by U(M) gauge interactions.

  14. Scalable Optical Architectures for Electronic Holography.

    NASA Astrophysics Data System (ADS)

    St.-Hilaire, Pierre

    Holography has long been recognized as an effective way to convey the information of complex 3-dimensional structures such as those encountered in medical imaging, computer-aided design and navigation. However, attempts at implementing a real-time holographic display device have been hampered by the enormous space-bandwidth products required by such a task. I present here an approach that alleviates many of the problems encountered in previous attempts at real-time computer generated holography. The basic idea underlying the MIT electronic holography display is the use of an acousto-optic modulator as a dynamic display medium and the synthesis of a large aperture by scanning the image of the modulator. The original implementation of the display is unsuitable for images larger than a few square centimeters, because the necessary optical space -bandwidth product become unmanageable by the electronic and optical subsystems. The goal of this thesis is to demonstrate that large displays can be implemented with available technologies if we break the space bandwidth product in small segments at both the image plane and Fourier plane, i.e. if we take a parallel approach. In the image plane domain the display space-bandwidth product can be increased by simultaneously writing multiple acoustic columns on a single crystal and then optically multiplexing the resulting holograms. I discuss the proper conditions under which the interline crosstalk remains acceptable and introduce a scanning geometry that allows for such a multiple channel operation. The Fourier domain can also be segmented in small domains, each being processed by a different scanning element. I describe the behavior of the image when such a segmentation in implemented and I then derive the conditions under which it can be effected without incurring significant image degradation. I finally describe the implementation of these concepts into a large scale holographic display which includes the use of an array of 6

  15. Holography In An Industrial Environment

    NASA Astrophysics Data System (ADS)

    Parker, R. J.; Jones, D. G.

    1988-01-01

    Holography has recently achieved new importance as a means of providing the data necessary for the development and validation of computer models. Increasingly, design work is being performed through the application of complicated three-dimensional models to gas flow prediction and the use of finite-element models for investigation of mechanical behaviour and stress. This paper reviews the many applications of holography that have been developed at Rolls-Royce over the past 20 years. These cover all of the major fields within holographic interferometry; flow visualisation, nondestructive testing, vibration analysis, and holographic contouring. Of equal interest with the techniques themselves are the problems encountered and overcome in applying these techniques in a demanding and at times hostile industrial environment away from the laboratory. The extensive use of high-power pulsed lasers has greatly facilitated this move and has allowed holography to be used routinely in normal component test areas.

  16. Digital holography display (3)

    NASA Astrophysics Data System (ADS)

    Lee, Cheok Peng; Zheng, Huadong; Chia, Yong Poo; Cheng, Chee Yuen; Yu, Yang; Yu, Yingjie; Asundi, Anand

    2013-06-01

    This paper is to describe a color digital holographic projector and this system is comprised of RGB lasers, 3 units of Digital Micro-Mirror Device (DMD) and high speed rotating diffuser. In this research, we focused on colorings Digital holograms and synchronized RGB digital holograms versus rotated diffuser. To achieve this phenomenon, three of the holograms optical path need to be aligned to pass through a same beam splitter and eventually combined as one colored holograms output While, this colored hologram will be reconstructed on volumetric screen (rotated diffuser) at the floating manner in free space. To obtain these result 3 key factors is investigated: 1. To configured 1 master and 2 slaves digital micro mirror illumination time 2. To reconstructed holograms orientation angle diffuser versus rotating speed. 3. To synchronize rotating diffuser speed versus DMD frame-rate Last but not least, the team built a prototype Color Digital Holography Display but more developments are required to follow up such as, enhance system's reliability, robustness, compactness and 3D realistic images floating in the free air space.

  17. Electron Holography: phases matter.

    PubMed

    Lichte, Hannes

    2013-06-01

    Essentially, all optics is wave optics, be it with light, X-rays, neutrons or electrons. The information transfer from the object to the image can only be understood in terms of waves given by amplitude and phase. However, phases are difficult to measure: for slowly oscillating waves such as sound or low-frequency electromagnetic waves, phases can be measured directly; for high frequencies this has to be done by heterodyne detection, i.e. superposition with a reference and averaging over time. In optics, this is called interferometry. Because interference is mostly very difficult to achieve, phases have often been considered 'hidden variables' seemingly pulling the strings from backstage, only visible by their action on the image intensity. This was almost the case in conventional Electron Microscopy with the phase differences introduced by an object. However, in the face of the urgent questions from solid state physics and materials science, these phases have to be determined precisely, because they encode the most dominant object properties, such as charge distributions and electromagnetic fields. After more than six decades of very patient advancement, electron interferometry and holography offer unprecedented analytical facilities down to an atomic scale. Akira Tonomura has prominently contributed to the present state. PMID:23620338

  18. GPU-accelerated compressive holography.

    PubMed

    Endo, Yutaka; Shimobaba, Tomoyoshi; Kakue, Takashi; Ito, Tomoyoshi

    2016-04-18

    In this paper, we show fast signal reconstruction for compressive holography using a graphics processing unit (GPU). We implemented a fast iterative shrinkage-thresholding algorithm on a GPU to solve the ℓ1 and total variation (TV) regularized problems that are typically used in compressive holography. Since the algorithm is highly parallel, GPUs can compute it efficiently by data-parallel computing. For better performance, our implementation exploits the structure of the measurement matrix to compute the matrix multiplications. The results show that GPU-based implementation is about 20 times faster than CPU-based implementation. PMID:27137282

  19. Dynamic Structures through Microdifferential Holography

    PubMed Central

    Sharnoff, Mark; Brehm, Lawrence P.; Henry, Richard W.

    1986-01-01

    The principles of microdifferential holography are developed primarily from nonmathematical argument, and the method's capabilities are compared with those of x-ray and optical diffraction. Microdifferential holography is very sensitive to small displacements of strongly scattering elements of a specimen whether or not they can be optically resolved. We present and interpret differential images of electrical activity of neurons and of contractile activity of isolated skeletal fibers. The latter confirm the suggestion of earlier work that the dynamic regions of contracting muscle are organized along myofibrillar segments rather than by sarcomeres. ImagesFIGURE 2FIGURE 3FIGURE 4FIGURE 5FIGURE 6FIGURE 7 PMID:19431634

  20. Luminal Na+/H+ exchange in the proximal tubule

    PubMed Central

    Bobulescu, I. Alexandru

    2010-01-01

    The proximal tubule is critical for whole-organism volume and acid–base homeostasis by reabsorbing filtered water, NaCl, bicarbonate, and citrate, as well as by excreting acid in the form of hydrogen and ammonium ions and producing new bicarbonate in the process. Filtered organic solutes such as amino acids, oligopeptides, and proteins are also retrieved by the proximal tubule. Luminal membrane Na+/H+ exchangers either directly mediate or indirectly contribute to each of these processes. Na+/H+ exchangers are a family of secondary active transporters with diverse tissue and subcellular distributions. Two isoforms, NHE3 and NHE8, are expressed at the luminal membrane of the proximal tubule. NHE3 is the prevalent isoform in adults, is the most extensively studied, and is tightly regulated by a large number of agonists and physiological conditions acting via partially defined molecular mechanisms. Comparatively little is known about NHE8, which is highly expressed at the lumen of the neonatal proximal tubule and is mostly intracellular in adults. This article discusses the physiology of proximal Na+/H+ exchange, the multiple mechanisms of NHE3 regulation, and the reciprocal relationship between NHE3 and NHE8 at the lumen of the proximal tubule. PMID:18853182

  1. Hybridization approach to in-line and off-axis (electron) holography for superior resolution and phase sensitivity

    PubMed Central

    Ozsoy-Keskinbora, C.; Boothroyd, C. B.; Dunin-Borkowski, R. E.; van Aken, P. A.; Koch, C. T.

    2014-01-01

    Holography - originally developed for correcting spherical aberration in transmission electron microscopes - is now used in a wide range of disciplines that involve the propagation of waves, including light optics, electron microscopy, acoustics and seismology. In electron microscopy, the two primary modes of holography are Gabor's original in-line setup and an off-axis approach that was developed subsequently. These two techniques are highly complementary, offering superior phase sensitivity at high and low spatial resolution, respectively. All previous investigations have focused on improving each method individually. Here, we show how the two approaches can be combined in a synergetic fashion to provide phase information with excellent sensitivity across all spatial frequencies, low noise and an efficient use of electron dose. The principle is also expected to be widely to applications of holography in light optics, X-ray optics, acoustics, ultra-sound, terahertz imaging, etc. PMID:25387480

  2. Hybridization approach to in-line and off-axis (electron) holography for superior resolution and phase sensitivity.

    PubMed

    Ozsoy-Keskinbora, C; Boothroyd, C B; Dunin-Borkowski, R E; van Aken, P A; Koch, C T

    2014-01-01

    Holography--originally developed for correcting spherical aberration in transmission electron microscopes--is now used in a wide range of disciplines that involve the propagation of waves, including light optics, electron microscopy, acoustics and seismology. In electron microscopy, the two primary modes of holography are Gabor's original in-line setup and an off-axis approach that was developed subsequently. These two techniques are highly complementary, offering superior phase sensitivity at high and low spatial resolution, respectively. All previous investigations have focused on improving each method individually. Here, we show how the two approaches can be combined in a synergetic fashion to provide phase information with excellent sensitivity across all spatial frequencies, low noise and an efficient use of electron dose. The principle is also expected to be widely to applications of holography in light optics, X-ray optics, acoustics, ultra-sound, terahertz imaging, etc. PMID:25387480

  3. Acoustic Source Localization in Aircraft Interiors Using Microphone Array Technologies

    NASA Technical Reports Server (NTRS)

    Sklanka, Bernard J.; Tuss, Joel R.; Buehrle, Ralph D.; Klos, Jacob; Williams, Earl G.; Valdivia, Nicolas

    2006-01-01

    Using three microphone array configurations at two aircraft body stations on a Boeing 777-300ER flight test, the acoustic radiation characteristics of the sidewall and outboard floor system are investigated by experimental measurement. Analysis of the experimental data is performed using sound intensity calculations for closely spaced microphones, PATCH Inverse Boundary Element Nearfield Acoustic Holography, and Spherical Nearfield Acoustic Holography. Each method is compared assessing strengths and weaknesses, evaluating source identification capability for both broadband and narrowband sources, evaluating sources during transient and steady-state conditions, and quantifying field reconstruction continuity using multiple array positions.

  4. Time dependent holography

    NASA Astrophysics Data System (ADS)

    Das, Diptarka

    One of the most important results emerging from string theory is the gauge gravity duality (AdS/CFT correspondence) which tells us that certain problems in particular gravitational backgrounds can be exactly mapped to a particular dual gauge theory a quantum theory very similar to the one explaining the interactions between fundamental subatomic particles. The chief merit of the duality is that a difficult problem in one theory can be mapped to a simpler and solvable problem in the other theory. The duality can be used both ways. Most of the current theoretical framework is suited to study equilibrium systems, or systems where time dependence is at most adiabatic. However in the real world, systems are almost always out of equilibrium. Generically these scenarios are described by quenches, where a parameter of the theory is made time dependent. In this dissertation I describe some of the work done in the context of studying quantum quench using the AdS/CFT correspondence. We recover certain universal scaling type of behavior as the quenching is done through a quantum critical point. Another question that has been explored in the dissertation is time dependence of the gravity theory. Present cosmological observations indicate that our universe is accelerating and is described by a spacetime called de-Sitter(dS). In 2011 there had been a speculation over a possible duality between de-Sitter gravity and a particular field theory (Euclidean SP(N) CFT). However a concrete realization of this proposition was still lacking. Here we explicitly derive the dS/CFT duality using well known methods in field theory. We discovered that the time dimension emerges naturally in the derivation. We also describe further applications and extensions of dS/CFT. KEYWORDS: Holography, AdS/CFT correspondence, Quantum Quench, dS/CFT correspondence, Chaos.

  5. Industrial holography: The Rolls-Royce experience

    NASA Astrophysics Data System (ADS)

    Parker, R. J.; Jones, D. G.

    1986-07-01

    Holographic interferometry applications to flow visualization, nondestructive testing, vibration analysis, and holographic contouring are described. Problems encountered and overcome in applying these techniques in a demanding, at times hostile, environment away from the laboratory are discussed. Holography for routine vibration analysis; pulsed holography of large, vibrating assemblies; holographic vibrometry on rotating components; holographic flow visualization in wind tunnels; and pulsed holography in rotating, transonic flow are illustrated.

  6. Virtual integral holography

    NASA Astrophysics Data System (ADS)

    Venolia, Dan S.; Williams, Lance

    1990-08-01

    components of a stereo display system with user point-of-view tracking for interactive 3D, and a digital realization of integral composite display which we term virtual integral holography. The primary drawbacks of holographic display - film processing turnaround time, and the difficulties of displaying scenes in full color -are obviated, and motion parallax cues provide easy 3D interpretation even for users who cannot see in stereo.

  7. 'Micromanaging de Sitter holography'

    SciTech Connect

    Dong, Xi; Horn, Bart; Silverstein, Eva; Torroba, Gonzalo; /SLAC /Stanford U., Phys. Dept. /Santa Barbara, KITP

    2010-08-26

    We develop tools to engineer de Sitter vacua with semi-holographic duals, using elliptic fibrations and orientifolds to uplift Freund-Rubin compactifications with CFT duals. The dual brane construction is compact and constitutes a microscopic realization of the dS/dS correspondence, realizing d-dimensional de Sitter space as a warped compactification down to (d-1)-dimensional de Sitter gravity coupled to a pair of large-N matter sectors. This provides a parametric microscopic interpretation of the Gibbons-Hawking entropy. We illustrate these ideas with an explicit class of examples in three dimensions, and describe ongoing work on four-dimensional constructions. The Gibbons-Hawking entropy of the de Sitter horizon [1] invites a microscopic interpretation and a holographic formulation of inflating spacetimes. Much progress was made in the analogous problem in black hole physics using special black holes in string theory whose microstates could be reliably counted, such as those analyzed in [2,3]; this led to the AdS/CFT correspondence [4]. In contrast, a microscopic understanding of the entropy of de Sitter space is more difficult for several reasons including its potential dynamical connections to other backgrounds (metastability), the absence of a non-fluctuating timelike boundary, and the absence of supersymmetry. In this paper, we develop a class of de Sitter constructions in string theory, built up from AdS/CFT dual pairs along the lines of [5], which are simple enough to provide a microscopic accounting of the parametric scaling of the Gibbons-Hawking entropy. These models realize microscopically a semi-holographic description of metastable de Sitter space which had been derived macroscopically in [6]. It would also be interesting to connect this to other approaches to de Sitter holography such as [7, 8] and to other manifestations of the de Sitter entropy such as [9]. The construction is somewhat analogous to neutral black branes analyzed in [11]. We will

  8. Digital Holography Display (2)

    NASA Astrophysics Data System (ADS)

    Lee, Cheok Peng; Asundi, A.; Yu, Yang; Xiao, Zhen Zhong

    This paper describes the extension work from the last Digital Holography Projector System. From the developed works shows that, some unforeseen factors have created the difficulties for the system alignment. Such factors are the DMD frame rate, light source and diffractive zero order. It is really the challenging development works to achieve the virtual 3D model display on the high speed rotation screen. The three most key factors are emphasizing: 1) The display device's frame rate; 2) The light source orientation angle; and 3) The zero order filtering optic. 1) This device's is the digital micro mirror, in short is DMD. It is the high speed switching device has developed by the most recent technology. The switching frame rate can go up as high as 291fps. At first, the 8 bits depth file must be digitalized and stored for DMD onboard Ram. The digitalized data are transmitting from the PC USB to DMD onboard Ram. Instead of the data are downloading directly from the PC to DVI or VGA during display, this downloading method cause slower down the display speed, which is the common frame rate of 30 Hz. Next, the onboard Ram data then transfer to the DMD mirror's for display, at the 8 bits 291 fps speed. At this frame rate, the display 2D image can almost cover for 10 of out of the 360 0 in 1 revolution. 2) This laser light source must be installed such that free for orientated in any arbitrary angle from 220 to 450. Which is normalized to the DMD mirrors and the brief sketch show on figure (a). The purpose of orientated the light source is ensure that multi diffractive order would be reflected straight from the mirrors. (This multi diffractive order is the phenomenon of the digital micro mirror's characteristic). This mean, the reconstruct images would be followed the DMD normalized direction reflected up to fibre conduit. Moreover, this orientated method install of the laser light source is making space for other optical lenses or device driver/controller. Because, all

  9. Acoustic-optical imaging without immersion

    NASA Technical Reports Server (NTRS)

    Liu, H.

    1979-01-01

    System using membraneous end wall of Bragg cell to separate test specimen from acoustic transmission medium, operates in real time and uses readily available optical components. System can be easily set up and maintained by people with little or no training in holography.

  10. Industrial Applications Of Holography In Aerospatiale

    NASA Astrophysics Data System (ADS)

    Le Floc'H, C.; Gagnage, B.

    1982-10-01

    AEROSPAT1ALE occupies a leading position in the European aerospace industry. Its industrial potential is exemplified by : - Its 4 divisions : Aircraft, Helicopters, Tactical Missiles and Space and Balistic Systems. - Its 11 factories. - Its 6 subsidiaries. The vitality of the firm can be demonstrated by a few figures : - Turnover (fiscal 1980 without the subsidiaries), 13, 169 millions French Francs. - Exports (in 1980), 48,2%. - Workforce (on 31st December 1980), 38,857 of whom 3,919 were with the subsidiaries. Among Aerospatiale products, we can quote : - Ariane. - Airbus. - Super Puma, Astar, Dauphin. - Tactical Missiles AS 15, AS 30, AM 59. - Satellites Meteostat, Intelsat V and Exosat. Certain projects were carried out in multi-national cooperation. These high-performance, high-reliability products presuppose the implementation of advanced technology. Hence, in order to maintain their standard, we use non-destructive testing thechniques such as X-rays or ultrasonics which have given complete satisfaction in the detection of flaws. However, to reduce the inspection contribution to the cost price of our products, we were led to develop new, large-scale methods, such as acoustic analysis and holographic interferometry. This paper covers the uses of holography in an industrial environment. We shall discuss the technical advantages of the method, illustrated by several examples,and the economical advantages, demonstrated by the practical example of an inspection line. Finally for the enhancement of Aerospatiale's technology (new materials, and holographic inspection) we will go on to outline other fields of activity.

  11. Differential regulation of Na/H antiporter by acid in renal epithelial cells and fibroblasts.

    PubMed Central

    Moe, O W; Miller, R T; Horie, S; Cano, A; Preisig, P A; Alpern, R J

    1991-01-01

    Increased Na/H antiporter activity has been demonstrated after in vivo chronic metabolic acidosis as well as in vitro acid preincubation of cultured rabbit renal tubule cells. To study the underlying molecular mechanisms of this adaptive increase in Na/H antiporter activity, the present studies examined the effect of low pH media on Na/H antiporter activity and mRNA abundance in cultured renal tubule cells. Na/H antiporter activity was increased by 60% in a mouse renal cortical tubule cell line (MCT), and by 90% in an opossum kidney cell line (OKP) after 24 h of preincubation in acid (low [HCO3]) media. The ethylisopropylamiloride sensitivity of the Na/H antiporters were different in these two cell lines (MCT IC50 = 65 nM; OKP IC50 = 4.5 microM). In MCT cells, Na/H antiporter mRNA abundance measured by RNA blots increased by two- to fivefold after 24 h in low [HCO3] media. Na/H antiporter mRNA abundance was also increased in MCT cells with high CO2 preincubation as well as in rat renal cortex with in vivo chronic acid feeding. In contrast to renal epithelia, acid preincubation of NIH 3T3 fibroblasts led to suppression of Na/H antiporter activity. RNA blots of 3T3 fibroblasts revealed the same size Na/H antiporter transcript as in MCT cells. However, Na/H antiporter mRNA levels were suppressed by acid preincubation. These studies demonstrate differential regulation of Na/H antiporter activity and mRNA abundance in renal epithelial cells and fibroblasts in response to an acidotic environment. Images PMID:1658050

  12. X-ray fluorescence holography.

    PubMed

    Hayashi, Kouichi; Happo, Naohisa; Hosokawa, Shinya; Hu, Wen; Matsushita, Tomohiro

    2012-03-01

    X-ray fluorescence holography (XFH) is a method of atomic resolution holography which utilizes fluorescing atoms as a wave source or a monitor of the interference field within a crystal sample. It provides three-dimensional atomic images around a specified element and has a range of up to a few nm in real space. Because of this feature, XFH is expected to be used for medium-range local structural analysis, which cannot be performed by x-ray diffraction or x-ray absorption fine structure analysis. In this article, we explain the theory of XFH including solutions to the twin-image problem, an advanced measuring system, and data processing for the reconstruction of atomic images. Then, we briefly introduce our recent applications of this technique to the analysis of local lattice distortions in mixed crystals and nanometer-size clusters appearing in the low-temperature phase of a shape-memory alloy. PMID:22318258

  13. Multicolor Holography With Phase Shifting

    NASA Technical Reports Server (NTRS)

    Vikram, Chandra S.

    1996-01-01

    Prototype apparatus constructed to test feasibility of two-color holographic interferometric scheme in which data for reconstructing holographic wavefront obtained with help of phase-shifting technique. Provides two sets of data needed to solve equations for effects of temperature and concentration. Concept extended to holography at three or more wavelengths to measure three or more phenomena associated with significant variations in index of refraction

  14. Use of holography in medicine

    NASA Astrophysics Data System (ADS)

    Myers, Bert

    1995-02-01

    Because of their high impact and sharpness, we believe that holograms make better teaching tools than conventional images, and one day will be common in medical texts and journals. To be maximally effective as teaching tools, in some instances there must be labels or arrows within the images. Although our main interest is to use holography as a teaching device, other investigators are already using it for diagnosis and treatment.

  15. Holography: childrens' window to relativity

    NASA Astrophysics Data System (ADS)

    MacShane, James E.

    1995-02-01

    This paper is concerned with the development of the concept of natural education. Psychology has discovered that all humans learn intuitively the cultural concepts of time from birth to eight and one-half to ten years of age. Einstein showed us that this must also be the natural time for the development of spatial concepts. The importance of this has been dramatized for me in the past eight years that I have been developing the Laser Arts and Holography Programs and Workshops. I have worked with over 100,000 students kindergarten through eighth grade. I have worked with 175 students age 8 to 10 in three hour and one half workshops specifically on the development of time and space concepts. The concepts developed are based upon the vast amount of psychological evidence related to the natural development of time and space understandings, Dr. Nils Abramson's 'Light in Flight' and subsequent work on the clarification of relativity through holography, and Maria Montessori's method of Scientific Education. The paper also demonstrates the natural method of teaching science to younger students is to teach scientifically. All of the research which has been done in the past 100 years has been used by the educational institutions to try to improve the system. What has not been done is changing the system to how humans learn. Because of the perceived hi-tech nature of the program I am able to dramatize the potential. An outline for a holography curriculum kindergarten through eighth grade is included.

  16. Progress in industrial holography in France

    NASA Astrophysics Data System (ADS)

    Smigielski, Paul

    1992-01-01

    Industrial applications of holography in France are briefly reviewed. Particular attention is given to nondestructive testing of helicopter blades at Aerospatiale Central Laboratory, the use of holography at Renault for car-engine vibration study, vibration characterization of turbo-jet engine components at SNECMA, and vibration analysis of plates in an industrial hemodynamic tunnel.

  17. Introduction to an introduction to holography

    NASA Astrophysics Data System (ADS)

    Unterseher, Fred D.; Deem, Rebecca E.

    1995-02-01

    A preliminary introduction to holography geared towards artists and the general public is discussed. The method is based on a participatory approach that relates holography to psychology/perception, science/physics, and art/imaging. The overall intention is designed to break down unconscious assumptions.

  18. HOLONET: a network for training holography

    NASA Astrophysics Data System (ADS)

    Pombo, Pedro; Santos, Emanuel

    2014-07-01

    Holography is an optics technique based on wave physics and lasers with several applications at our day life. The production of holograms involves experimental work based on hands-on activities and creativity. All these elements can contribute to the promotion of experimental teaching of optics and training on holography. The hologram itself acting as a final result from a long process of research and study can enable the engagement of high school students on physics and promote the stimulus on optics learning. Taking these assumptions into account a network of schools working on holography was built involving thirty schools from all country. Holography systems were developed and several hands-on activities were constructed. During last sixteen years students are working on laser optics and holography producing different kinds of holograms. This study presents all holography labs implemented at schools and it will analyzed the holography systems and materials developed for students. Training strategy will be discussed and holograms obtained by students will be presented. Results obtained show us that holography can be implemented as a strategy for promoting the learning of optics and it is a particular way to involve students on experimental work and lab research. Results obtained during this study will be presented in detail and analyzed with focus on students performance. Educational results, teachers training, prizes and other positive outcomes will be discussed and compared.

  19. Aesthetics and representation in holography

    NASA Astrophysics Data System (ADS)

    Kac, Eduardo

    1995-02-01

    Every medium has a code, a set of rules or conventions according to which determined elements are organized into a signifying system. The English language is a code as is perspective in painting and photography. In the first case, the elements are phonemes organized into words and sentences according to a social convention: the syntax of English. In the second case, the elements are dots and lines organized into pictures according to a geometric method. An artist or movement can break the conventions of the medium, as has done Cezanne with painting, Moholy-Nagy with photography and cummings with the English idiom in poetry, and create new elements and rules for combining them. If this is done, the level of predictability (or conventionality) is lowered and unpredictability is increased -- becoming more difficult for the immediate audience to understand it. But once these new rules are learned and the ideas behind them widely understood, the level of unpredictability is lowered and they become new conventions that can be accepted by the audience. Holographic artists exploring the medium -- as opposed to advertisers using holography, who favor a high level of predictability -- are breaking several visual and cultural conventions. As a matter of fact, holography is so new that many questions are left open about the nature of the medium. Therefore, any attempt to clarify the issues raised by holography on a cultural level has a prospective (and not conclusive) tone, concentrating more thoroughly on general points and on the promise of its potentialities than on the records of its historical achievements so far.

  20. Holography through optically active windows

    NASA Technical Reports Server (NTRS)

    Decker, A. J.

    1979-01-01

    By using two orthogonally polarized reference beams, holograms can be recorded through stressed windows and the reconstructed virtual image will show no stress pattern. As shown analytically, the stress-pattern-free hologram is recordable for any polarization state of the object illumination. Hence, the more efficient nondepolarizing diffuser can be used in performing holography through stressed windows if two reference beams are used. Results are presented for a pair of machined polysulfone windows intended for use in a holographic flow-visualization setup in a single-stage-compressor test rig.

  1. Holography stabilizes the vacuum energy.

    PubMed

    Thomas, Scott

    2002-08-19

    Gravitational holography is argued to render the cosmological constant stable against divergent quantum corrections, thus providing a technically natural solution to the cosmological constant problem. Evidence for quantum stability of the cosmological constant is illustrated in a number of examples including bulk descriptions in terms of delocalized degrees of freedom, boundary screen descriptions on stretched horizons, and nonsupersymmetric conformal field theories as dual descriptions of anti-de Sitter space. In an expanding universe, holographic quantum contributions to the stress-energy tensor are argued to be at most of order the energy density of the dominant matter component. PMID:12190453

  2. Functional role of polar amino acid residues in Na+/H+ exchangers.

    PubMed Central

    Wiebe, C A; Dibattista, E R; Fliegel, L

    2001-01-01

    Na(+)/H(+) exchangers are a family of ubiquitous membrane proteins. In higher eukaryotes they regulate cytosolic pH by removing an intracellular H(+) in exchange for an extracellular Na(+). In yeast and Escherichia coli, Na(+)/H(+) exchangers function in the opposite direction to remove intracellular Na(+) in exchange for extracellular H(+). Na(+)/H(+) exchangers display an internal pH-sensitivity that varies with the different antiporter types. Only recently have investigations examined the amino acids involved in pH-sensitivity and in cation binding and transport. Histidine residues are good candidates for H(+)-sensing amino acids, since they can ionize within the physiological pH range. Histidine residues have been shown to be important in the function of the E. coli Na(+)/H(+) exchanger NhaA and in the yeast Na(+)/H(+) exchanger sod2. In E. coli, His(225) of NhaA may function to interact with, or regulate, the pH-sensory region of NhaA. In sod2, His(367) is also critical to transport and may be a functional analogue of His(225) of NhaA. Histidine residues are not critical for the function of the mammalian Na(+)/H(+) exchanger, although an unusual histidine-rich sequence of the C-terminal tail has some influence on activity. Other amino acids involved in cation binding and transport by Na(+)/H(+) exchangers are only beginning to be studied. Amino acids with polar side chains such as aspartate and glutamate have been implicated in transport activity of NhaA and sod2, but have not been studied in the mammalian Na(+)/H(+) exchanger. Further studies are needed to elucidate the mechanisms involved in pH-sensitivity and cation binding and transport by Na(+)/H(+) exchangers. PMID:11415429

  3. Damage Detection Using Holography and Interferometry

    NASA Technical Reports Server (NTRS)

    Decker, Arthur J.

    2003-01-01

    This paper reviews classical approaches to damage detection using laser holography and interferometry. The paper then details the modern uses of electronic holography and neural-net-processed characteristic patterns to detect structural damage. The design of the neural networks and the preparation of the training sets are discussed. The use of a technique to optimize the training sets, called folding, is explained. Then a training procedure is detailed that uses the holography-measured vibration modes of the undamaged structures to impart damage-detection sensitivity to the neural networks. The inspections of an optical strain gauge mounting plate and an International Space Station cold plate are presented as examples.

  4. Holography with standing surface plasma waves

    NASA Technical Reports Server (NTRS)

    Cowan, J. J.

    1974-01-01

    Holography with standing surface plasma waves, where both reference and object beams propagate in opposite directions, has been investigated using an Al reflection grating coated with evaporated As2S3 layers. The image, which appears only for p-polarization and at certain critical angles, is enhanced by the Lippman-Bragg effect and by an increase in intensity over ordinary holography approximately equal to the absolute value of the real part of the dielectric constant for Al. Also considered is holography with object light alone in photoresist layers, using the beam-splitting properties of the grating.

  5. Photochromic materials for holography: issues and constraints

    NASA Astrophysics Data System (ADS)

    Bianco, Andrea; Pariani, Giorgio; Zanutta, Alessio; Castagna, Rossella; Bertarelli, Chiara

    2012-03-01

    Photochromic materials can find application in holography, thanks to the peculiar possibility to change reversibly their transparency in the visible (amplitude holography) and their refractive index in the near infrared region (phase holography). The main advantages of such materials are rewritability and self-development. A large change of the key property is crucial to obtain efficient devices and some strategies are followed, accordingly. Production of the holograms have open important issues regarding the film thickness and the nonlinear response to light, because of the strong absorption of the writing light by the material. Results related to these topics, mainly focused on diarylethene-based materials, are reported.

  6. Frustrated total internal reflection acoustic field sensor

    DOEpatents

    Kallman, Jeffrey S.

    2000-01-01

    A frustrated total internal reflection acoustic field sensor which allows the acquisition of the acoustic field over an entire plane, all at once. The sensor finds use in acoustic holography and acoustic diffraction tomography. For example, the sensor may be produced by a transparent plate with transparent support members tall enough to support one or more flexible membranes at an appropriate height for frustrated total internal reflection to occur. An acoustic wave causes the membrane to deflect away from its quiescent position and thus changes the amount of light that tunnels through the gap formed by the support members and into the membrane, and so changes the amount of light reflected by the membrane. The sensor(s) is illuminated by a uniform tight field, and the reflection from the sensor yields acoustic wave amplitude and phase information which can be picked up electronically or otherwise.

  7. Holography as a Liberal Arts Physics Course

    ERIC Educational Resources Information Center

    Huang, Jacob Wen-kuang

    1978-01-01

    Describes a liberal arts physics course for all majors interested in holography or to satisfy the general education requirements. An outline of the course and some experience of offering it are given. (Author/GA)

  8. Holography: Art in an Ephemeral Medium.

    ERIC Educational Resources Information Center

    Buterbaugh, James G.

    1979-01-01

    The science of holography provides an opportunity to see reality by illusion using laser light, lenses, and mirrors. To develop as holographic artists, students must first gain proficiency in using its techniques, equipment, and materials. (Author/CMV)

  9. Present State Iof Holography In Japan

    NASA Astrophysics Data System (ADS)

    Suzuki, Masane; Hayashi, Yuzo; Yamamoto, Y.

    1983-07-01

    In 1948,Dr. Dennis Gabor introduced the theory of holography as "the optical recording of the object wave formed by the resulting interference pattern of two mutually coherent, component light beams." Through the studies of enumerous practical applications, the theory of holography was further advanced to be used in conjunction with the laser beam to better serve a more practical minded industry. Such developments were introduced and engineered by Dr. Emmett Leith and Dr. Juris Upatnieks in 1962.

  10. Helioseismic Holography and a Study of the Process of Magnetic Flux Disappearance in Canceling Bipoles

    NASA Technical Reports Server (NTRS)

    Lindsey, Charles; Harvey, Karen L.; Braun, D.; Jones, H. P.; Penn, M.; Hassler, D.

    2001-01-01

    Project 1: We have developed and applied a technique of helioseismic holography along the lines of originally set out in our proposal. The result of the application of this diagnostic technique to solar activity and the quiet Sun has produced a number of important discoveries: (1) acoustic moats surrounding sunspots; (2) acoustic glories surround large active regions; (3) acoustic condensations beneath active regions; and (4) temporally-resolve acoustic images of a solar flare. These results have been published in a series of papers in the Astrophysical Journal. We think that helioseismic holography is now established as the most powerful and discriminating diagnostic in local helioseismology. Project 2: We conducted a collaborative observational program to define the physical character and magnetic geometry of canceling magnetic bipoles aimed at determining if the cancellation process is the result of submergence of magnetic fields. This assessment is based on ground-based observations combining photospheric and chromospheric magnetograms from NSO/KP, BBSO, and SOHO-MDI, and EUV and X-ray images from SOHO EIT/CDS, Yohkoh/SXT, and TRACE. Our study involves the analysis of data taken during three observing campaigns to define the height structure of canceling bipoles inferred from magnetic field and intensity images, and how this varies with time. We find that some canceling bipoles can be explained by the submerge of their magnetic flux. A paper on the results of this analysis will be presented at an upcoming scientific meeting and be written up for publication.

  11. Visualizing Breath using Digital Holography

    NASA Astrophysics Data System (ADS)

    Hobson, P. R.; Reid, I. D.; Wilton, J. B.

    2013-02-01

    Artist Jayne Wilton and physicists Peter Hobson and Ivan Reid of Brunel University are collaborating at Brunel University on a project which aims to use a range of techniques to make visible the normally invisible dynamics of the breath and the verbal and non-verbal communication it facilitates. The breath is a source of a wide range of chemical, auditory and physical exchanges with the direct environment. Digital Holography is being investigated to enable a visually stimulating articulation of the physical trajectory of the breath as it leaves the mouth. Initial findings of this research are presented. Real time digital hologram replay allows the audience to move through holographs of breath-born particles.

  12. Digital holography-based steganography.

    PubMed

    Hamam, Habib

    2010-12-15

    A steganographic method offering a high hiding capacity is presented in which the techniques of digital holography are used to distribute information from a small secret image across the larger pixel field of a cover image. An iterative algorithm is used to design a phase-only or complex hologram from a padded version of the secret image, quantizing this data according to the carrier data bits that are available within the intended cover image. By introducing the hologram data only into low-order bits of larger amplitude cover pixels, the change in the cover image remains imperceptible to the casual observer, with a peak signal-to-noise ratio of >40 dB. PMID:21165128

  13. Digital holography to light field

    NASA Astrophysics Data System (ADS)

    Asundi, Anand; Zuo, Chao

    2014-05-01

    Holography uses wave (physical) optical principles of interference and diffraction to record and display images. Interference allows us to record the amplitude and phase of the optical wave emanating from an object on a film or recording medium and diffraction enables us to see this wave-field, i.e. the amplitude and phase of the object. Visually this corresponds to both perspective and depth information being reconstructed as in the original scene. Digital Holography has enabled quantification of phase which in some applications provides meaningful engineering parameters. There is growing interest in reconstructing this wavefield without interference. Thus the non-interferometric Transport of Intensity Equation (TIE) method is gaining increased research, which uses two or more defocused images to reconstruct the phase. Due to its non-interferometric nature, TIE relaxes the stringent beam-coherence requirements for interferometry, extending its applications to various optical fields with arbitrary spatial and temporal coherence. The alternate school of thought emerges from the computer science community primarily deals with ray optics. In a normal imaging system all rays emerging from an object point into are focused to a conjugate image point. Information of ray direction is lost and thus the perspective and depth information. A light field image is one that has information of both amplitude and direction of rays fanning from any object point and thus provides perspective (or what could be termed as phase) of the object wave as well. It would thus be possible to extract phase as we know it from this albeit for a coherent illumination case.

  14. Microstructure measurement of digital holography

    NASA Astrophysics Data System (ADS)

    Li, Jicheng; Tian, Ailing; Wang, Hongjun; Zhu, Xueliang; Wang, Chunhui; Liu, Bingcai; Asundi, Anand

    2015-02-01

    Miniaturization is a development trend of electronics, machinery and information systems, while micro structure brought a large amount of new development for industrial and research applications, whereas, slow measuring speed and two-dimensional results of traditional micro measurement could not meet our needs, it's urgent to find a matching testing techniques with more sensitivity, more effectiveness and better to have a real-time three-dimensional display. Digital holography applied to the measurement of micro structure, it made up for the lacking of traditional micro structure measure systems of too much time consuming, poor immunity, easily damaging samples with its simple structure, high accuracy, non contact features and three-dimensional reproduction. This paper analyzed the key factors of digital holographic recording and reproducing process.In order to solve the low quality of holograms captured by traditional recording system, holograms and pre-processing algorithm was combined for real-time, by observing the holograms and delicate adjusting the system, to ensure that the collected holograms with full use of CCD width while convenient for subsequent processing. In the processing of reproduction,the influence of spectrum choice, reconstruction wavelength and algorithms and unwrapping algorithm was been studied, and finally obtained an accurate three-dimensional topography of the object. The improved rerecording system and reconstruction algorithm mentioned above solved the low holography quality, much noise and not clear shortcomings of the reconstructed image. Experiment on a raster, compared with traditional system and algorithm results, results showed that the recording system and determine algorithms can reproduce the three-dimensional topography of the object with high precision and has a broader applicability.

  15. Modular Holography For Use In Industry

    NASA Astrophysics Data System (ADS)

    Ettemeyer, A.; Schorner, J.; Rottenkolber, H.; Obermeier, E.

    1989-01-01

    A new system of holography is presented. This modular testing equipment fulfils the performance requirements for industrial measuring equipment. A holographic camera-head module with the approximate dimensions of a television camera is installed close to or actually on the object to be tested. For holography using a continous wave laser it is necessary only to secure the object to a base-plate mounted on vibration insulators. This is not necessary if pulse holography is used. Because of its small size, the measuring head can also be attached directly to the test object. This largely eliminates the effects of movements of the whole body of the objects. The technical realization of modular holography was made possible by the use of glass fibres. A rigid connection between the laser and the measuring apparatus is no longer necessary. The necessary light for the recording of the hologram is provided by the laser-base module and fed to the measuring head via a glass fibre cable. The hologram recorded by the measuring head is transmitted directly by means of a television camera to the computer-analyzer module, where it is evaluated and presented in user-friendly form. An example from industry is taken to demonstrate the use of the modular holography system.

  16. Modular Holography For Use In Industry

    NASA Astrophysics Data System (ADS)

    Ettemeyer, A.; Schomer, J.; Rottenkolber, H.; Obermeier, E.

    1988-06-01

    A new system of holography is presented. This modular testing equipment fulfils the performance requirements for industrial measuring equipment. A holographic camera-head module with the approximate dimensions of a television camera is installed close to or actually on the object to be tested. For holography using a continuous wave laser it is necessary only to secure the object to a base-plate mounted on vibration insulators. This is not necessary if pulse holography is used. Because of its small size, the measuring head can also be attached directly to the test object. This largely eliminates the effects of movements of the whole body of the objects. The technical realization of modular holography was made possible by the use of glass fibres. A rigid connection between the laser and the measuring apparatus is no longer necessary. The necessary light for the recording of the hologram is provided by the laser-base module and fed to the measuring head via a glass fibre cable. The hologram recorded by the measuring head is transmitted directly by means of a television camera to the computer-analyzer module, where it is evaluated and presented in user-friendly form. An example from industry is taken to demonstrate the use of the modular holography system.

  17. Wavelet image processing applied to optical and digital holography: past achievements and future challenges

    NASA Astrophysics Data System (ADS)

    Jones, Katharine J.

    2005-08-01

    The link between wavelets and optics goes back to the work of Dennis Gabor who both invented holography and developed Gabor decompositions. Holography involves 3-D images. Gabor decompositions involves 1-D signals. Gabor decompositions are the predecessors of wavelets. Wavelet image processing of holography, both optical holography and digital holography, will be examined with respect to past achievements and future challenges.

  18. Acoustic neuroma

    MedlinePlus

    Vestibular schwannoma; Tumor - acoustic; Cerebellopontine angle tumor; Angle tumor ... Acoustic neuromas have been linked with the genetic disorder neurofibromatosis type 2 (NF2). Acoustic neuromas are uncommon.

  19. GPU-based calculations in digital holography

    NASA Astrophysics Data System (ADS)

    Madrigal, R.; Acebal, P.; Blaya, S.; Carretero, L.; Fimia, A.; Serrano, F.

    2013-05-01

    In this work we are going to apply GPU (Graphical Processing Units) with CUDA environment for scientific calculations, concretely high cost computations on the field of digital holography. For this, we have studied three typical problems in digital holography such as Fourier transforms, Fresnel reconstruction of the hologram and the calculation of vectorial diffraction integral. In all cases the runtime at different image size and the corresponding accuracy were compared to the obtained by traditional calculation systems. The programs have been carried out on a computer with a graphic card of last generation, Nvidia GTX 680, which is optimized for integer calculations. As a result a large reduction of runtime has been obtained which allows a significant improvement. Concretely, 15 fold shorter times for Fresnel approximation calculations and 600 times for the vectorial diffraction integral. These initial results, open the possibility for applying such kind of calculations in real time digital holography.

  20. Spin and wavelength multiplexed nonlinear metasurface holography

    PubMed Central

    Ye, Weimin; Zeuner, Franziska; Li, Xin; Reineke, Bernhard; He, Shan; Qiu, Cheng-Wei; Liu, Juan; Wang, Yongtian; Zhang, Shuang; Zentgraf, Thomas

    2016-01-01

    Metasurfaces, as the ultrathin version of metamaterials, have caught growing attention due to their superior capability in controlling the phase, amplitude and polarization states of light. Among various types of metasurfaces, geometric metasurface that encodes a geometric or Pancharatnam–Berry phase into the orientation angle of the constituent meta-atoms has shown great potential in controlling light in both linear and nonlinear optical regimes. The robust and dispersionless nature of the geometric phase simplifies the wave manipulation tremendously. Benefitting from the continuous phase control, metasurface holography has exhibited advantages over conventional depth controlled holography with discretized phase levels. Here we report on spin and wavelength multiplexed nonlinear metasurface holography, which allows construction of multiple target holographic images carried independently by the fundamental and harmonic generation waves of different spins. The nonlinear holograms provide independent, nondispersive and crosstalk-free post-selective channels for holographic multiplexing and multidimensional optical data storages, anti-counterfeiting, and optical encryption. PMID:27306147

  1. Spin and wavelength multiplexed nonlinear metasurface holography

    NASA Astrophysics Data System (ADS)

    Ye, Weimin; Zeuner, Franziska; Li, Xin; Reineke, Bernhard; He, Shan; Qiu, Cheng-Wei; Liu, Juan; Wang, Yongtian; Zhang, Shuang; Zentgraf, Thomas

    2016-06-01

    Metasurfaces, as the ultrathin version of metamaterials, have caught growing attention due to their superior capability in controlling the phase, amplitude and polarization states of light. Among various types of metasurfaces, geometric metasurface that encodes a geometric or Pancharatnam-Berry phase into the orientation angle of the constituent meta-atoms has shown great potential in controlling light in both linear and nonlinear optical regimes. The robust and dispersionless nature of the geometric phase simplifies the wave manipulation tremendously. Benefitting from the continuous phase control, metasurface holography has exhibited advantages over conventional depth controlled holography with discretized phase levels. Here we report on spin and wavelength multiplexed nonlinear metasurface holography, which allows construction of multiple target holographic images carried independently by the fundamental and harmonic generation waves of different spins. The nonlinear holograms provide independent, nondispersive and crosstalk-free post-selective channels for holographic multiplexing and multidimensional optical data storages, anti-counterfeiting, and optical encryption.

  2. Spin and wavelength multiplexed nonlinear metasurface holography.

    PubMed

    Ye, Weimin; Zeuner, Franziska; Li, Xin; Reineke, Bernhard; He, Shan; Qiu, Cheng-Wei; Liu, Juan; Wang, Yongtian; Zhang, Shuang; Zentgraf, Thomas

    2016-01-01

    Metasurfaces, as the ultrathin version of metamaterials, have caught growing attention due to their superior capability in controlling the phase, amplitude and polarization states of light. Among various types of metasurfaces, geometric metasurface that encodes a geometric or Pancharatnam-Berry phase into the orientation angle of the constituent meta-atoms has shown great potential in controlling light in both linear and nonlinear optical regimes. The robust and dispersionless nature of the geometric phase simplifies the wave manipulation tremendously. Benefitting from the continuous phase control, metasurface holography has exhibited advantages over conventional depth controlled holography with discretized phase levels. Here we report on spin and wavelength multiplexed nonlinear metasurface holography, which allows construction of multiple target holographic images carried independently by the fundamental and harmonic generation waves of different spins. The nonlinear holograms provide independent, nondispersive and crosstalk-free post-selective channels for holographic multiplexing and multidimensional optical data storages, anti-counterfeiting, and optical encryption. PMID:27306147

  3. Advanced technology development multi-color holography

    NASA Technical Reports Server (NTRS)

    Vikram, Chandra S.

    1994-01-01

    Several key aspects of multi-color holography and some non-conventional ways to study the holographic reconstructions are considered. The error analysis of three-color holography is considered in detail with particular example of a typical triglycine sulfate crystal growth situation. For the numerical analysis of the fringe patterns, a new algorithm is introduced with experimental verification using sugar-water solution. The role of the phase difference among component holograms is also critically considered with examples of several two- and three-color situations. The status of experimentation on two-color holography and fabrication of a small breadboard system is also reported. Finally, some successful demonstrations of unconventional ways to study holographic reconstructions are described. These methods are deflectometry and confocal optical processing using some Spacelab III holograms.

  4. Holography in the curriculum of medical institutes

    NASA Astrophysics Data System (ADS)

    Gorelik, S. Y.; Nagibina, I. M.; Baranov, S. V.; Bolshakov, Oleg P.; Petrishin, V. L.

    1995-11-01

    Holography at present is the most effective technique of obtaining 3-D images of different objects. That's why there is more and more dissemination of holography in different fields of science and engineering, for example, in medicine. So, last time the technique of synthesized holograms obtained for evaluating inner organs states of patients without surgical intervention was designed. Due to properties of the hologram such as high quality of image and relative simplicity of duplication it is clear that holography could take its place in the curriculum of medical specializations because posters, photos, and models cannot give a full notation about an object of interest. The attempt to obtain holographical complete sets to demonstrate the most frequent pathologic changes of a human's bones was undertaken by our Institutes. The aim of our research was to obtain holograms with the following properties: minimum cost and high quality of reconstructed image to identify both the presented objects and the pathologic changes of them.

  5. DSS-24 microwave holography measurements

    NASA Technical Reports Server (NTRS)

    Rochblatt, D. J.; Withington, P. M.; Jackson, H. J.

    1995-01-01

    The JPL DSN Microwave Antenna Holography System (MAHST) was applied to the newly constructed DSS-24 34-m beam-waveguide antenna at Goldstone, California. The application of MAHST measurements and corrections at DSS 24 provided the critical RF performance necessary to not only meet the project requirements and goals, but to surpass them. A performance increase of 0.35 dB at X-band (8.45 GHz) and 4.9 dB at Ka-band (32 GHz) was provided by MAHST, resulting in peak efficiencies of 75.25 percent at X-band and 60.6 percent at Ka-band (measured from the Cassegrain focus at f1). The MAHST enabled setting the main reflector panels of DSS 24 to 0.25-mm rms, making DSS 24 the highest precision antenna in the NASA/JPL DSN. The precision of the DSS-24 antenna (diameter/rms) is 1.36 x 10(exp 5), and its gain limit is at 95 GHz.

  6. Systems analysis for DSN microwave antenna holography

    NASA Technical Reports Server (NTRS)

    Rochblatt, D. J.

    1989-01-01

    Proposed systems for Deep Space Network (DSN) microwave antenna holography are analyzed. Microwave holography, as applied to antennas, is a technique which utilizes the Fourier Transform relation between the complex far-field radiation pattern of an antenna and the complex aperture field distribution to provide a methodology for the analysis and evaluation of antenna performance. Resulting aperture phase and amplitude distribution data are used to precisely characterize various crucial performance parameters, including panel alignment, subreflector position, antenna aperture illumination, directivity at various frequencies, and gravity deformation. Microwave holographic analysis provides diagnostic capacity as well as being a powerful tool for evaluating antenna design specifications and their corresponding theoretical models.

  7. Holography on the Spacelab 3 mission

    NASA Technical Reports Server (NTRS)

    Owen, Robert B.; Kroes, R. L.

    1985-01-01

    Spacelab 3's Fluid Experiment System, in which triglycine sulfate crystals were produced by a low temperature solution-growth technique, employs holography as its primary data-gathering system. This use of holography allows optical techniques which would be difficult to apply in orbit to be used after the holographic data is returned to ground laboratories, using an analysis of the reconstructed holographic image. The system used allows both single- and double-exposure holograms to be obtained in two separate orthogonal configurations.

  8. Minkowski diagram in relativity and holography.

    PubMed

    Abramson, N

    1988-05-01

    Now that ultrashort laser pulses can be used in holography, the temporal and spatial resolution approach the same order of magnitude. In that case the limited speed of light sometimes causes large measuring errors if correction methods are not introduced. Therefore, we want to revive the Minkowski diagram, which was invented in 1908 to visualize relativistic relations between time and space. We show how this diagram in a modified form can be used to derive both the static holodiagram, used for conventional holography, including ultrahigh-speed recordings of wavefronts, and a dynamic holodiagram used for studying the apparent distortions of objects recorded at relativistic speeds. PMID:20531662

  9. Holography - Application To Art: Curatorial Observations

    NASA Astrophysics Data System (ADS)

    Dinsmore, Sydney

    1987-06-01

    An exploration of the need to define a specific and critical language to describe the art of holography. Within any discussion of art, critical analysis must maintain an objective openess, particularily when the discourse concerns new media. To apply technological invention to art, new media is often without precedent on which to base criticism and bias. For this reason, holography falls prey to comparative rhetoric and established evaluation of other forms of imaging,as photography emulated the compositional romanticism of painting initially. Isolated and often misunderstood within the context of history, new media vascillates between legitimacy and curiosity in an attempt to create specific parameters to identify perceptual transition.

  10. Recent advances in digital holography [invited].

    PubMed

    Osten, Wolfgang; Faridian, Ahmad; Gao, Peng; Körner, Klaus; Naik, Dinesh; Pedrini, Giancarlo; Singh, Alok Kumar; Takeda, Mitsuo; Wilke, Marc

    2014-09-20

    This article presents an overview of recent advances in the field of digital holography, ranging from holographic techniques designed to increase the resolution of microscopic images, holographic imaging using incoherent illumination, phase retrieval with incoherent illumination, imaging of occluded objects, and the holographic recording of depth-extended objects using a frequency-comb laser, to the design of an infrastructure for remote laboratories for digital-holographic microscopy and metrology. The paper refers to current trends in digital holography and explains them using new results that were recently achieved at the Institute for Applied Optics of the University Stuttgart. PMID:25322137

  11. Na+/H+ Exchange Activity in the Plasma Membrane of Arabidopsis1

    PubMed Central

    Qiu, Quan-Sheng; Barkla, Bronwyn J.; Vera-Estrella, Rosario; Zhu, Jian-Kang; Schumaker, Karen S.

    2003-01-01

    In plants, Na+/H+ exchangers in the plasma membrane are critical for growth in high levels of salt, removing toxic Na+ from the cytoplasm by transport out of the cell. The molecular identity of a plasma membrane Na+/H+ exchanger in Arabidopsis (SOS1) has recently been determined. In this study, immunological analysis provided evidence that SOS1 localizes to the plasma membrane of leaves and roots. To characterize the transport activity of this protein, purified plasma membrane vesicles were isolated from leaves of Arabidopsis. Na+/H+ exchange activity, monitored as the ability of Na to dissipate an established pH gradient, was absent in plants grown without salt. However, exchange activity was induced when plants were grown in 250 mm NaCl and increased with prolonged salt exposure up to 8 d. H+-coupled exchange was specific for Na, because chloride salts of other monovalent cations did not dissipate the pH gradient. Na+/H+ exchange activity was dependent on Na (substrate) concentration, and kinetic analysis indicated that the affinity (apparent Km) of the transporter for Na+ is 22.8 mm. Data from two experimental approaches supports electroneutral exchange (one Na+ exchanged for one proton): (a) no change in membrane potential was measured during the exchange reaction, and (b) Na+/H+ exchange was unaffected by the presence or absence of a membrane potential. Results from this research provide a framework for future studies into the regulation of the plant plasma membrane Na+/H+ exchanger and its relative contribution to the maintenance of cellular Na+ homeostasis during plant growth in salt. PMID:12805632

  12. SLC9/NHE gene family, a plasma membrane and organellar family of Na+/H+ exchangers *

    PubMed Central

    Donowitz, Mark; Tse, C. Ming; Fuster, Daniel

    2013-01-01

    This brief review of the human Na/H exchanger gene family introduces a new classification with three subgroups to the SLC9 gene family. Progress in the structure and function of this gene family is reviewed with structure based on homology to the bacterial Na/H exchanger NhaA. Human diseases which result from genetic abnormalities of the SLC9 family are discussed although the exact role of these transporters in causing any disease is not established, other than poorly functioning NHE3 in congenital Na diarrhea PMID:23506868

  13. Entangled States, Holography and Quantum Surfaces

    SciTech Connect

    Chapline, G F

    2003-08-13

    Starting with an elementary discussion of quantum holography, we show that entangled quantum states of qubits provide a ''local'' representation of the global geometry and topology of quantum Riemann surfaces. This representation may play an important role in both mathematics and physics. Indeed, the simplest way to represent the fundamental objects in a ''theory of everything'' may be as muti-qubit entangled states.

  14. Haptic Holography/Touching the Ethereal

    NASA Astrophysics Data System (ADS)

    Page, Michael

    2013-02-01

    Haptic Holography, was perhaps, first proposed by workers at MIT in the 90s. The Media Lab, headed up by Dr. Stephen Benton, with published papers by Wendy Plesiak and Ravi Pappuh. -1 Recent developments in both the technology of digital holography and haptics have made it practical to conduct further investigations. Haptic holography is auto-stereoscopic and provides co-axial viewing for the user. Haptic holography may find application in medical & surgical training and as a new form of synthetic reality for artists and designers. At OCAD's PHASE Lab (Prototypes for Holographic Art and Science Explorations) workers are exploring hybrid forms of augmented reality, that combine haptics, interactivity and auto-stereoscopic imagery. Conventional Haptic environments, while presenting a 3D physics environment, typically provide a 2D visual work/play space. Orienteering in such an environment creates an uncertain spatial relationship for the user. Our group creates 3d models from which we create holographic constructs. The same model is used to create the physics environment. The two models are super-imposed. The result: Holograms you can touch.

  15. Synthetic optical holography for rapid nanoimaging

    PubMed Central

    Schnell, M.; Carney, P. S.; Hillenbrand, R.

    2014-01-01

    Holography has paved the way for phase imaging in a variety of wide-field techniques, including electron, X-ray and optical microscopy. In scanning optical microscopy, however, the serial fashion of image acquisition seems to challenge a direct implementation of traditional holography. Here we introduce synthetic optical holography (SOH) for quantitative phase-resolved imaging in scanning optical microscopy. It uniquely combines fast phase imaging, technical simplicity and simultaneous operation at visible and infrared frequencies with a single reference arm. We demonstrate SOH with a scattering-type scanning near-field optical microscope (s-SNOM) where it enables reliable quantitative phase-resolved near-field imaging with unprecedented speed. We apply these capabilities to nanoscale, non-invasive and rapid screening of grain boundaries in CVD-grown graphene, by recording 65 kilopixel near-field images in 26 s and 2.3 megapixel images in 13 min. Beyond s-SNOM, the SOH concept could boost the implementation of holography in other scanning imaging applications such as confocal microscopy. PMID:24651276

  16. Advanced technology development multi-color holography

    NASA Technical Reports Server (NTRS)

    Vikram, Chandra S.

    1993-01-01

    This is the final report of the Multi-color Holography project. The comprehensive study considers some strategic aspects of multi-color holography. First, various methods of available techniques for accurate fringe counting are reviewed. These are heterodyne interferometry, quasi-heterodyne interferometry, and phase-shifting interferometry. Phase-shifting interferometry was found to be the most suitable for multi-color holography. Details of experimentation with a sugar solution are also reported where better than 1/200 of a fringe order measurement capability was established. Rotating plate glass phase shifter was used for the experimentation. The report then describes the possible role of using more than two wavelengths with special reference-to-object beam intensity ratio needs in multicolor holography. Some specific two- and three-color cases are also described in detail. Then some new analysis methods of the reconstructed wavefront are considered. These are deflectometry, speckle metrology, confocal optical signal processing, and phase shifting technique related applications. Finally, design aspects of an experimental breadboard are presented.

  17. EDITORIAL: Optical tomography and digital holography

    NASA Astrophysics Data System (ADS)

    Coupland, Jeremy; Lobera, Julia

    2008-07-01

    The articles in this special feature in Measurement Science and Technology concern exciting new developments in the field of digital holography—the process of electronically recording and numerically reconstructing an optical field [1]. Making use of the enormous advances in digital imaging and computer technology, digital holography is presented in a range of applications from fluid flow measurement and structural analysis to medical imaging. The science of digital holography rests on the foundations of optical holography, on the work of Gabor in the late 1940s, and on the development of laser sources in the 1960s, which made his vision a practical reality [2]. Optical holography, however, uses a photosensitive material, both to record a latent image and subsequently to behave as a diffractive optical element with which to reconstruct the incident field. In this way display holograms, using silver halide materials for example, can produce life-size images that are virtually indistinguishable from the object itself [3]. Digital holography, in contrast, separates the steps of recording and reconstruction, and the final image is most often in the form of a 3D computer model. Of course, television cameras have been used from the beginnings of holography to record interferometric images. However, the huge disparity between the resolution of holographic recording materials (more than 3000 cycles/mm) and television cameras (around 50 cycles/mm) was raised as a major concern by early researchers. TV holography, as it was sometimes called, generally recorded low numerical aperture (NA) holograms producing images with characteristically large speckle and was therefore more often referred to as electronic speckle pattern interferomery (ESPI) [4]. It is possible, however, to record large NA holograms on a sensor with restricted resolution by using an objective lens or a diverging reference wave [5]. This is generally referred to as digital holographic microscopy (DHM) since

  18. Mechanical characterization of bone samples by ultrasound holography at 100 MHz

    NASA Astrophysics Data System (ADS)

    Hartmann, H.; Cobet, U.; Grill, W.

    2007-04-01

    Point source ultrasound holography has been applied to small bone samples using a phase sensitive scanning acoustic microscope (PSAM) in transmission at about 100 MHz. Conversion of the phase images into appropriate data matrices and subsequent data processing yielded the angle dependent ultrasound velocities for the observed space sector. The mathematical tools were derived from geometrical considerations and the basic properties of propagating acoustic waves. The results match conventional direction resolved measurements of the sound velocity in bone. However, the presented technique requires only two specimens. The demonstrated results are obtained for sample sizes of 5 × 5 × 0.5 mm 3. No chemical or other treatment which could significantly influence the composition of the bone samples is required. The technique is illustrated and the results are demonstrated and discussed.

  19. Full-field detection of surface defects using real-time holography and optical correlation techniques

    NASA Astrophysics Data System (ADS)

    Blackshire, James L.; Duncan, Bradley D.

    1999-02-01

    Innovative optical NDE techniques are being developed for the full-field detection and evaluation of surface defects and defect precursors in titanium and aluminum based alloys. The techniques are based on frequency-translated holography and optical correlation principles, and use bacteriohodopsin (bR) holographic films and temporal correlation techniques for real-time storage and retrieval of Surface Acoustic Waves (SAW) features and embedded surface defect information. The SAW waves induced on the material surface being studied are made to interfere with optical light waves, and fringes are produced that are a function of optical Doppler shifts induced by phonon-photon interaction on the surface of the materials. Visualization of these SAW patterns allow for NDE characterization of features on and near the surface of the materials, including defect and defect precursor sites. Preliminary results are provided for real-time bR holographic recordings of acoustic patterns induced on Al2024-T3 material surfaces.

  20. Test of the interaction potential energy for Na+-H2 by gaseous ion transport data

    NASA Astrophysics Data System (ADS)

    Viehland, Larry A.; Buchachenko, Alexei A.

    2014-09-01

    Transport properties of Na+ ions in gaseous hydrogen are calculated using the recently developed "beyond Monchick-Mason" (BMM) approximation and an ab initio Na+-H2 potential energy surface. Good agreement with the experimental data on the reduced mobility and longitudinal diffusion coefficient proves the accuracy of the surface and the adequacy of the BMM method, allowing for its optimal parameterization.

  1. Salicylate and catechol levels are maintained in nahG transgenic poplar

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Metabolic profiling was used to investigate the molecular phenotypes of transgenic Populus tremula x P. alba bybrids expressing the nahG transgene, a bacterial gene encoding salicylate hydroxylase that converts salicylic acid to catechol. Despite the efficacy of this transgenic approach to reducing...

  2. Computer holography by means of the laser diodes

    NASA Astrophysics Data System (ADS)

    Borodin, Arthur N.; Ilchenko, Volodymyr; Malov, Alexander N.; Sychevskiy, Alexey V.

    2007-02-01

    A computer holography is the optical hologram recording on the CCD-matrix with digital reconstruction of the 2Dimages for the different volume object cross-sections. The possibility to use compact semiconductor laser diodes in the computer holography for 3D-scene registration is experimentally proved in the D. Gabor's scheme. For off axis hologram recording the S. Benton's scheme for holography using is suggested.

  3. Simple optical setup implementation for digital Fourier transform holography

    NASA Astrophysics Data System (ADS)

    de Oliveira, G. N.; Rodrigues, D. M. C.; dos Santos, P. A. M.

    2011-01-01

    In the present work a simple implementation of Digital Fourier Transform Holography (DFTH) setup is discussed. This is obtained making a very simple modification in the classical setup arquiteture of the Fourier Transform holography. It is also demonstrated the easy and practical viability of the setup in an interferometric application for mechanical parameters determination. The work is also proposed as an interesting advanced introductory training for graduated students in digital holography.

  4. Sodium-Proton (Na(+)/H(+)) Antiporters: Properties and Roles in Health and Disease.

    PubMed

    Padan, Etana; Landau, Meytal

    2016-01-01

    The transmembranal Na(+)/H(+) antiporters transport sodium (or several other monovalent cations) in exchange for H(+) across lipid bilayers in all kingdoms of life. They are critical in pH homeostasis of the cytoplasm and/or organelles. A particularly notable example is the SLC9 gene family, which encodes Na(+)/H(+) exchangers (NHEs) in many species from prokaryotes to eukaryotes. In humans, these proteins are associated with the pathophysiology of various diseases. Yet, the most extensively studied Na(+)/H(+) antiporter is Ec-NhaA, the main Na(+)/H(+) antiporter of Escherichia coli.The crystal structure of down-regulated Ec-NhaA, determined at acidic pH, has provided the first structural insights into the antiport mechanism and pH regulation of an Na(+)/H(+) antiporter. It reveals a unique structural fold (called the NhaA fold) in which transmembrane segments (TMs) are organized in inverted-topology repeats, including two antiparallel unfolded regions that cross each other, forming a delicate electrostatic balance in the middle of the membrane. This unique structural fold (The NhaA fold) contributes to the cation binding site and facilitates the rapid conformational changes expected for Ec-NhaA. The NhaA fold has now been recognized to be shared by four Na(+)/H(+) antiporters (bacterial and archaeal) and a Na(+) symporter. Remarkably, no crystal structure of any of the human Na(+)/H(+) antiporters exists. Nevertheless, the Ec-NhaA crystal structure has enabled the structural modeling of NHE1, NHE9, and NHA2, three human plasmalemmal proteins that are members of the SLC9 family that are involved in human pathophysiology. Moreover, as outlined in this review, developments in the field, including cellular and biophysical methods that enable ion levels and fluxes to be measured in intact cells as well as in knockout mice, have led to striking advances in the identification and characterization of plasma membrane NHEs and NHA.Very little is known about the endomembrane

  5. Imaging nanoparticles in cells by nanomechanical holography

    SciTech Connect

    Tetard, Laurene; Passian, Ali; Venmar, Katherine T; Lynch, Rachel M; Voy, Brynn H; Shekhawat, Gajendra; Dravid, Vinayak; Thundat, Thomas George

    2008-06-01

    Nanomaterials have potential medical applications, for example in the area of drug delivery, and their possible adverse effects and cytotoxicity are curently receiving attention1,2. Inhalation of nanoparticles is of great concern, because nanoparticles can be easily aerosolized. Imaging techniques that can visualize local populations of nanoparticles at nanometre resolution within the structures of cells are therefore important3. Here we show that cells obtained from mice exposed to single-walled carbon nanohorns can be probed using a scanning probe microscopy technique called scanning near field ultrasonic holography. The nanohorns were observed inside the cells, and this was further confirmed using micro Raman spectroscopy. Scanning near field ultrasonic holography is a useful technique for probing the interactions of engineered nanomaterials in biological systems, which will greatly benefit areas in drug delivery and nanotoxicology.

  6. Limits of computational white-light holography

    NASA Astrophysics Data System (ADS)

    Mader, Sebastian; Kozacki, Tomasz; Tompkin, Wayne

    2013-02-01

    Recently, computational holograms are being used in applications, where previously conventional holograms were applied. Compared to conventional holography, computational holography is based on imaging of virtual objects instead of real objects, which renders them somewhat more flexibility. Here, computational holograms are calculated based on the superposition of point sources, which are placed at the mesh vertices of arbitrary 3D models. The computed holograms have full parallax and exhibit a problem in viewing that we have called "ghosting", which is linked to the viewing of computational holograms based on 3D models close to the image plane. Experimental white-light reconstruction of these holograms showed significant blurring, which is explained here based on simulations of the lateral as well as the axial resolution of a point image with respect to the source spectrum and image distance. In accordance with these simulations, an upper limit of the distance to the image plane is determined, which ensures high quality imaging.

  7. Industrial Holography Combined With Image Processing

    NASA Astrophysics Data System (ADS)

    Schorner, J.; Rottenkolber, H.; Roid, W.; Hinsch, K.

    1988-01-01

    Holographic test methods have gained to become a valuable tool for the engineer in research and development. But also in the field of non-destructive quality control holographic test equipment is now accepted for tests within the production line. The producer of aircraft tyres e. g. are using holographic tests to prove the guarantee of their tyres. Together with image processing the whole test cycle is automatisized. The defects within the tyre are found automatically and are listed on an outprint. The power engine industry is using holographic vibration tests for the optimization of their constructions. In the plastics industry tanks, wheels, seats and fans are tested holographically to find the optimum of shape. The automotive industry makes holography a tool for noise reduction. Instant holography and image processing techniques for quantitative analysis have led to an economic application of holographic test methods. New developments of holographic units in combination with image processing are presented.

  8. Imaging nanoparticles in cells by nanomechanical holography

    NASA Astrophysics Data System (ADS)

    Tetard, Laurene; Passian, Ali; Venmar, Katherine T.; Lynch, Rachel M.; Voy, Brynn H.; Shekhawat, Gajendra; Dravid, Vinayak P.; Thundat, Thomas

    2008-08-01

    Nanomaterials have potential medical applications, for example in the area of drug delivery, and their possible adverse effects and cytotoxicity are curently receiving attention. Inhalation of nanoparticles is of great concern, because nanoparticles can be easily aerosolized. Imaging techniques that can visualize local populations of nanoparticles at nanometre resolution within the structures of cells are therefore important. Here we show that cells obtained from mice exposed to single-walled carbon nanohorns can be probed using a scanning probe microscopy technique called scanning near field ultrasonic holography. The nanohorns were observed inside the cells, and this was further confirmed using micro Raman spectroscopy. Scanning near field ultrasonic holography is a useful technique for probing the interactions of engineered nanomaterials in biological systems, which will greatly benefit areas in drug delivery and nanotoxicology.

  9. ORGANIZATION AND EVOLUTION OF NAPHTHALENE CATABOLIC PATHWAYS: SEQUENCE OF THE DNA ENCODING 2-HYDROXYCHROMEME-2-CARBOXYLATE ISOMERASE AND TRANS-O-HYDROXYBENZYLIDENEPYRUVATE HYDRATASE-ALDOLASE FROM THE NAH7 PLASMID

    EPA Science Inventory

    The sequence of a 2,437-bp DNA segment from the naphthalene upper catabolic pathway operon of plasmid NAH7 was determined. This segment contains three large open reading frames designated nahQ, nahE, and nahD. The first of these is the 3 end of an open reading frame that has no k...

  10. Measuring Shapes Of Reflectors By Microwave Holography

    NASA Technical Reports Server (NTRS)

    Rahmat-Samii, Y.

    1989-01-01

    Pair of reports discusses theoretical foundation and recent theoretical and practical developments in use of microwave holography to measure surfaces of microwave antennas. (Second report abbreviated version of first report.) Microwave holographic measurements provide acceptable accuracy and are more convenient and less time consuming than optical and mechanical measurements, especially where measurements repeated. Microwave holographyic metrology of lare reflectors, first reported in 1976, improved into accurate technique with potential industrial applications.

  11. Applications of optical holography to applied mechanics.

    NASA Technical Reports Server (NTRS)

    Aprahamian, R.

    1972-01-01

    This paper provides a brief summary of applications of optical holography and holographic interferometry to applied solid mechanics. Basic equations commonly used in fringe interpretation are described and used to reduce the data contained on holographic interferograms. A comparison of data obtained holographically with analytical prediction is given wherever possible. Applications contained herein include front surface physics, study of bomb breakup, transverse wave propagation, study of mode shapes of panels at elevated temperatures, nondestructive testing, and vibration analysis.

  12. X-Ray Holography with Atomic Resolution

    NASA Astrophysics Data System (ADS)

    Tegze, Miklós

    1997-03-01

    In the conventional diffraction experiments only the intensity of the scattered radiation is recorded, its phase is lost. In holography [1], the scattered radiation is mixed with a reference wave and the resulting interference pattern is recorded. The hologram contains both the intensity and the phase information and the three dimensional image of the object can be reconstructed. The most important limitation of this imaging technique is the spatial resolution, which is given by the wavelength and/or by the source size. In the last decade the introduction of soft x-ray instead of visible light tremendously improved the resolution which reached a few hundred angstrom [2]. An other line in holography, based on the inside source concept, was suggested recently [3]. We have applied this concept for the case of fluorescent x-rays emitted by a single crystal. We were the first to demonstrate theoretically [4] and experimentally [5] the feasibility of x-ray holography with atomic resolution. We have recorded the holograms of different crystals and successfully reconstructed the three dimensional order of the atoms. [1] D. Gabor, Nature 161, 777 (1948). [2] M. Howels, C. Jacobsen, J. Kirz, R. Feder, K. McQuaid and S. Rothman, Science 238, 514 (1987). [3] A. Szöke, in Short Wavelength Coherent Radiation: Generation and Applications, T. Attwood, J. Booker (eds), AIP Conference Proceedings No. 147, New York (1986). [4] M. Tegze and G. Faigel, Europhys. Lett. 16, 41 (1991). [5] M. Tegze and G. Faigel, Nature 380, 49 (1996).

  13. Electron holography of devices with epitaxial layers

    SciTech Connect

    Gribelyuk, M. A. Ontalus, V.; Baumann, F. H.; Zhu, Z.; Holt, J. R.

    2014-11-07

    Applicability of electron holography to deep submicron Si devices with epitaxial layers is limited due to lack of the mean inner potential data and effects of the sample tilt. The mean inner potential V{sub 0} = 12.75 V of the intrinsic epitaxial SiGe was measured by electron holography in devices with Ge content C{sub Ge} = 18%. Nanobeam electron diffraction analysis performed on the same device structure showed that SiGe is strain-free in [220] direction. Our results showed good correlation with simulations of the mean inner potential of the strain-free SiGe using density function theory. A new method is proposed in this paper to correct electron holography data for the overlap of potentials of Si and the epitaxial layer, which is caused by the sample tilt. The method was applied to the analysis of the dopant diffusion in p-Field-effect Transistor devices with the identical gate length L = 30 nm, which had alternative SiGe geometry in the source and drain regions and was subjected to different thermal processing. Results have helped to understand electrical data acquired from the same devices in terms of dopant diffusion.

  14. Activation of Na-H exchange by intracellular lithium in barnacle muscle fibers.

    PubMed

    Davis, B A; Hogan, E M; Boron, W F

    1992-07-01

    We internally dialyzed single barnacle muscle fibers (BMF) for 90 min with a dialysis fluid (DF) containing no Na+ and either 0 or 100 mM Li+ and measured intracellular pH (pHi) with a microelectrode. During dialysis, the pH 8.0 artificial seawater (ASW) contained neither Na+ nor HCO3-. After we halted dialysis with a Li(+)-free/low-pH DF and allowed pHi to stabilize at approximately 6.8, adding 440 mM Na(+)-10 mM HCO3- to the ASW caused pHi to recover rapidly and stabilize at 7.32. In contrast, when the DF contained 100 mM Li+, pHi stabilized at 7.49. In fibers dialyzed to a pHi of approximately 7.2, Li+ stimulated a component of acid extrusion that was dependent on Na+ but not affected by SITS. Thus Li+ activates a Na(+)-dependent acid-extrusion mechanism other than the well characterized Na(+)-dependent Cl-HCO3 exchanger. To study the Li(+)-activated mechanism, we minimized Na(+)-dependent Cl-HCO3 exchange by raising pHDF to 7.35 and pretreated BMFs with SITS. We found that dialysis with Li+ elicits a Na(+)-dependent pHi increase that is largely blocked by amiloride, consistent with the hypothesis that Li+ activates a latent Na-H exchanger even at a normal pHi. In the absence of Li+, the Na-H exchanger is relatively inactive at pHi 7.35 (net acid-extrusion rate, Jnet = 9.5 microM/min) but modestly stimulated by reducing pHi to 6.8 (Jnet = 64 microM/min). In the presence of Li+, the Na-H exchanger is very active at pHi values of both 7.35 (Jnet = 141 microM/min) and 6.8 (Jnet = 168 microM/min). Thus Li+ alters the pHi sensitivity of the Na-H exchanger. Because the Na-H exchanger is only approximately 6% as active as the Na(+)-dependent Cl-HCO3 exchanger in the absence of Li+ at a pHi of approximately 6.8, we suggest that the major role of the Na-H exchanger may not be in pHi regulation but in another function such as cell-volume regulation. PMID:1322042

  15. Laser Holography. High Tech with High Potential for Learning Activities.

    ERIC Educational Resources Information Center

    Schlegel, Ronald D.

    1986-01-01

    This article discusses the procedure, historical development, and applications of holography, and discusses the feasibility and value of implementing a unit or course of study of laser holography into an existing photography laboratory and curriculum. An equipment and supplies list, giving supplies and cost, is included. (CT)

  16. Holography and Art - Using rainbow hologram in my works

    NASA Astrophysics Data System (ADS)

    Cho, Duck Hee

    2013-02-01

    Holography can be understood as one of the more sophisticated subjects within the realm of modern art. Even after several years of study and application, understanding Holography simply does not get any easier. For that reason, instead of trying to discuss both the technical and the artistic aspects of holography, the emphasis will strictly be on the latter. Just like any other paradigm or medium capable of fascinating the human hearts, holography has changed the way I encounter the world. Changed perception of the world brought me feelings of child-like delight. Among the various subdivisions of holography, I hold Rainbow Hologram exceptionally close to my heart. Not only is it related to my previous works but its bright, crisp and various color movements are also depicted wonderfully in 3-dimension. I would like to share my fascination with rainbow hologram with you.

  17. Integration of a conoscopic holography sensor on a CMM

    NASA Astrophysics Data System (ADS)

    Fernández, P.; Blanco, D.; Valiño, G.; Hoang, H.; Suárez, L.; Mateos, S.

    2012-04-01

    Conoscopic Holography is a non-contact digitizing technique used for verification and reverse engineering tasks. Conoscopic holography share some advantages with other non-contact digitizing techniques: surface digitizing from a secure distance and high point sampling rates. On the other hand, conoscopic holography owns some exclusive advantages: no occlusion problems, vision angles up to 85° and a higher robustness against variations in surface characteristics. The work presented here is part of a project that aims to evaluate conoscopic holography performance when used as an on-machine measurement system. Here, the scope is the integration of a conoscopic holography sensor onto a coordinates measuring machine. Special attention has been paid to calibration procedure, in order to achieve measurements with similar accuracy as those obtained with more common techniques, like laser triangulation sensors.

  18. NAH plasmid-mediated catabolism of anthracene and phenanthrene to naphthoic acids.

    PubMed Central

    Menn, F M; Applegate, B M; Sayler, G S

    1993-01-01

    Pseudomonas fluorescens 5R contains an NAH7-like plasmid (pKA1), and P. fluorescens 5R mutant 5RL contains a bioluminescent reporter plasmid (pUTK21) which was constructed by transposon mutagenesis. Polymerase chain reaction mapping confirmed the localization of lux transposon Tn4431 300 bp downstream from the start of the nahG gene. Two degradation products, 2-hydroxy-3-naphthoic acid and 1-hydroxy-2-naphthoic acid, were recovered and identified from P. fluorescens 5RL as biochemical metabolites from the biotransformation of anthracene and phenanthrene, respectively. This is the first report which provides direct biochemical evidence that the naphthalene plasmid degradative enzyme system is involved in the degradation of higher-molecular-weight polycyclic aromatic hydrocarbons other than naphthalene. Images PMID:8328810

  19. Membrane surface charge dictates the structure and function of the epithelial Na+/H+ exchanger

    PubMed Central

    Alexander, Robert Todd; Jaumouillé, Valentin; Yeung, Tony; Furuya, Wendy; Peltekova, Iskra; Boucher, Annie; Zasloff, Michael; Orlowski, John; Grinstein, Sergio

    2011-01-01

    The Na+/H+ exchanger NHE3 plays a central role in intravascular volume and acid–base homeostasis. Ion exchange activity is conferred by its transmembrane domain, while regulation of the rate of transport by a variety of stimuli is dependent on its cytosolic C-terminal region. Liposome- and cell-based assays employing synthetic or recombinant segments of the cytosolic tail demonstrated preferential association with anionic membranes, which was abrogated by perturbations that interfere with electrostatic interactions. Resonance energy transfer measurements indicated that segments of the C-terminal domain approach the bilayer. In intact cells, neutralization of basic residues in the cytosolic tail by mutagenesis or disruption of electrostatic interactions inhibited Na+/H+ exchange activity. An electrostatic switch model is proposed to account for multiple aspects of the regulation of NHE3 activity. PMID:21245831

  20. Characterization of Na+/H+ exchanger NHE8 in cultured renal epithelial cells.

    PubMed

    Zhang, Jianning; Bobulescu, Ion Alexandru; Goyal, Sunita; Aronson, Peter S; Baum, Michel G; Moe, Orson W

    2007-09-01

    NHE8 is expressed in the apical membrane of the proximal tubule and is predicted to be a Na+/H+ exchanger on the basis of its primary amino acid sequence. Functional characterization of native NHE8 in mammalian cells has not been possible to date. We screened a number of polarized renal cell lines for the plasma membrane Na+/H+ exchangers (NHE1, 2, 3, 4, and 8) and found only NHE1 and NHE8 transcripts in NRK cells by RT-PCR. NHE8 protein is expressed in the apical membrane of NRK cells as demonstrated by immunoblots, confocal fluorescent immunocytochemistry, and immunoelectron microscopy. NHE1, on the other hand, is expressed primarily in the basolateral membrane. Bilateral perfusion of NRK cells grown on permeable supports shows Na+/H+ exchange activity on both the apical and basolateral membranes. NHE8-specific small interfering RNA knocks down NHE8 protein expression but does not affect NHE1 protein levels. Knockdown of NHE8 protein is accompanied by a commensurate reduction in apical NHE activity, without altered basolateral NHE activity. Conversely, transfection of NHE1-specific small interfering RNA knocks down NHE1 protein expression without affecting NHE8 protein levels and reduces basolateral NHE activity without affecting apical NHE activity. NHE8 is the only apical membrane Na+/H+ exchanger in NRK cells. NHE8 activity is Na+ dependent, displaying a cooperative sigmoidal relationship, and is highly sensitive to 5-(N-ethyl-n-isopropyl)-amiloride (EIPA). NRK cells provide a useful system where NHE8 can be studied in its native environment. PMID:17581925

  1. On the ultrasonic holography. [procedures and equipment required for free liquid surface deformation method of holography

    NASA Technical Reports Server (NTRS)

    Zieniuk, J. K.

    1974-01-01

    The development of a system of ultrasonic holography is discussed. The limitations of the acousto-optical transformers, the scanning method, and the Pohlman cell are analyzed. The application of the free liquid surface deformation method is emphasized. The test equipment required for the liquid surface deformation method is described. An illustration of a typical test installation is provided.

  2. Na+/H+ exchanger 1 inhibition reverses manifestation of peripheral diabetic neuropathy in type 1 diabetic rats

    PubMed Central

    Lupachyk, Sergey; Watcho, Pierre; Shevalye, Hanna; Vareniuk, Igor; Obrosov, Alexander; Obrosova, Irina G.

    2013-01-01

    Evidence for an important role for Na+/H+ exchangers in diabetic complications is emerging. The aim of this study was to evaluate whether Na+/H+ exchanger 1 inhibition reverses experimental peripheral diabetic neuropathy. Control and streptozotocin-diabetic rats were treated with the specific Na+/H+ exchanger 1 inhibitor cariporide for 4 wk after 12 wk without treatment. Neuropathy end points included sciatic motor and sensory nerve conduction velocities, endoneurial nutritive blood flow, vascular reactivity of epineurial arterioles, thermal nociception, tactile allodynia, and intraepidermal nerve fiber density. Advanced glycation end product and markers of oxidative stress, including nitrated protein levels in sciatic nerve, were evaluated by Western blot. Rats with 12-wk duration of diabetes developed motor and sensory nerve conduction deficits, thermal hypoalgesia, tactile allodynia, and intraepidermal nerve fiber loss. All these changes, including impairment of nerve blood flow and vascular reactivity of epineurial arterioles, were partially reversed by 4 wk of cariporide treatment. Na+/H+ exchanger 1 inhibition was also associated with reduction of diabetes-induced accumulation of advanced glycation endproduct, oxidative stress, and nitrated proteins in sciatic nerve. In conclusion, these findings support an important role for Na+/H+ exchanger 1 in functional, structural, and biochemical manifestations of peripheral diabetic neuropathy and provide the rationale for development of Na+/H+ exchanger 1 inhibitors for treatment of diabetic vascular and neural complications. PMID:23736542

  3. Na+/H+ exchanger 1 inhibition reverses manifestation of peripheral diabetic neuropathy in type 1 diabetic rats.

    PubMed

    Lupachyk, Sergey; Watcho, Pierre; Shevalye, Hanna; Vareniuk, Igor; Obrosov, Alexander; Obrosova, Irina G; Yorek, Mark A

    2013-08-01

    Evidence for an important role for Na(+)/H(+) exchangers in diabetic complications is emerging. The aim of this study was to evaluate whether Na(+)/H(+) exchanger 1 inhibition reverses experimental peripheral diabetic neuropathy. Control and streptozotocin-diabetic rats were treated with the specific Na(+)/H(+) exchanger 1 inhibitor cariporide for 4 wk after 12 wk without treatment. Neuropathy end points included sciatic motor and sensory nerve conduction velocities, endoneurial nutritive blood flow, vascular reactivity of epineurial arterioles, thermal nociception, tactile allodynia, and intraepidermal nerve fiber density. Advanced glycation end product and markers of oxidative stress, including nitrated protein levels in sciatic nerve, were evaluated by Western blot. Rats with 12-wk duration of diabetes developed motor and sensory nerve conduction deficits, thermal hypoalgesia, tactile allodynia, and intraepidermal nerve fiber loss. All these changes, including impairment of nerve blood flow and vascular reactivity of epineurial arterioles, were partially reversed by 4 wk of cariporide treatment. Na(+)/H(+) exchanger 1 inhibition was also associated with reduction of diabetes-induced accumulation of advanced glycation endproduct, oxidative stress, and nitrated proteins in sciatic nerve. In conclusion, these findings support an important role for Na(+)/H(+) exchanger 1 in functional, structural, and biochemical manifestations of peripheral diabetic neuropathy and provide the rationale for development of Na(+)/H(+) exchanger 1 inhibitors for treatment of diabetic vascular and neural complications. PMID:23736542

  4. Monitoring of naphthalene catabolism by bioluminescence with nah-lux transcriptional fusions.

    PubMed Central

    Burlage, R S; Sayler, G S; Larimer, F

    1990-01-01

    We have demonstrated the efficacy of a light-generating genetic construction in describing the induction of a nah operon for the catabolism of naphthalene. A fragment from plasmid NAH7, which contains the promoter for the upper pathway of degradation, was transcriptionally fused to the lux genes of Vibrio fischeri. A Pseudomonas strain containing this construction is inducible to high levels of light production in the presence of a suitable substrate and the nahR regulatory gene product. This system was used to examine catabolic activity in a unique manner under a variety of growth conditions. Induction of bioluminescence was demonstrated to coincide with naphthalene degradation in all cases through the use of mineralization assays. A significant delay in bioluminescence and biodegradation was observed when naphthalene was added to batch cultures that were growing exponentially. These results suggest that the metabolism of naphthalene by this Pseudomonas strain is optimal when the growth rate of the culture is slow and is greatly reduced during exponential growth. Images PMID:2203729

  5. Arabidopsis thaliana and Saccharomyces cerevisiae NHX1 genes encode amiloride sensitive electroneutral Na+/H+ exchangers.

    PubMed Central

    Darley, C P; van Wuytswinkel , O C; van der Woude , K; Mager, W H; de Boer , A H

    2000-01-01

    Sodium at high millimolar levels in the cytoplasm is toxic to plant and yeast cells. Sequestration of Na(+) ions into the vacuole is one mechanism to confer Na(+)-tolerance on these organisms. In the present study we provide direct evidence that the Arabidopsis thaliana At-NHX1 gene and the yeast NHX1 gene encode low-affinity electroneutral Na(+)/H(+) exchangers. We took advantage of the ability of heterologously expressed At-NHX1 to functionally complement the yeast nhx1-null mutant. Experiments on vacuolar vesicles isolated from yeast expressing At-NHX1 or NHX1 provided direct evidence for pH-gradient-energized Na(+) accumulation into the vacuole. A major difference between NHX1 and At-NHX1 is the presence of a cleavable N-terminal signal peptide (SP) in the former gene. Fusion of the SP to At-NHX1 resulted in an increase in the magnitude of Na(+)/H(+) exchange, indicating a role for the SP in protein targeting or regulation. Another distinguishing feature between the plant and yeast antiporters is their sensitivity to the diuretic compound amiloride. Whereas At-NHX1 was completely inhibited by amiloride, NHX1 activity was reduced by only 20-40%. These results show that yeast as a heterologous expression system provides a convenient model to analyse structural and regulatory features of plant Na(+)/H(+) antiporters. PMID:10998367

  6. Ethereal presences in holography and photography

    NASA Astrophysics Data System (ADS)

    Richardson, M.; Byrne, Kay

    2007-02-01

    This paper examines the concept of the 'Presence of Absence' in post-mortem photography and holography, drawing upon both historical and lesser-known images as reference. To create a photographic negative one needs the presence of light to expose the light sensitive surface, be it glass, a polished plate or plastic. A hologram may also be created when a coherent light source, for example from a Laser, travels through a light sensitive material and falls upon the subject to be recorded. A holograph however, retains the optical qualities of both phase and amplitude, the memory of light. Both mediums recall, as it were, 'now absent moments', and confronts us with what is 'not there' as much as 'what is'. This paper examines the exploration of absence and presence in post-mortem photography and holography and it's a richly visceral visual language. A photonic syntax can interpret death as an elegant yet horrific aesthetic, the photograph may be beautify screened and yet obscene in its content. In essence one can be a voyeur, experiencing a mere visual whisper of the true nature of the subject. Our Victorian forefathers explored postmortem photography as an object of mourning, and at the close of the nineteenth century when Jack the Ripper had the inhabitants of White Chapel in a grip of fear, photography made its mark as a documentation of violent crime. Today, within contemporary photography, death is now presented within the confines of the 'Art Gallery', as a sensual, and at times, sensationalised art form. In exploring post-mortem imagery, both in holography and conventional photography, absence presents an aspect of death as startling in its unanimated form and detailed in its finite examination of mortality.

  7. Phase-space foundations of electron holography

    NASA Astrophysics Data System (ADS)

    Lubk, A.; Röder, F.

    2015-09-01

    We present a unified formalism for describing various forms of electron holography in quantum mechanical phase space including their extensions to quantum-state reconstructions. The phase-space perspective allows for taking into account partial coherence as well as the quantum mechanical detection process typically hampering the unique reconstruction of a wave function. We elaborate on the limitations imposed by the electron optical elements of the transmission electron microscope as well as the scattering at the target. The results provide the basis for vastly extending the scope of electron holographic techniques towards analyzing partially coherent signals such as inelastically scattered electrons or electron pulses used in ultrafast transmission electron microscopy.

  8. Multi-field inflation from holography

    SciTech Connect

    Garriga, Jaume; Urakawa, Yuko; Skenderis, Kostas E-mail: K.Skenderis@soton.ac.uk

    2015-01-01

    We initiate the study of multi-field inflation using holography. Bulk light scalar fields correspond to nearly marginal operators in the boundary theory and the dual quantum field theory is a deformation of a CFT by such operators. We compute the power spectra of adiabatic and entropy perturbations in a simple model and find that the adiabatic curvature perturbation is not conserved in the presence of entropy perturbations but becomes conserved when the entropy perturbations are set to zero or the model is effectively a single scalar model, in agreement with expectations from cosmological perturbation theory.

  9. A ripple tank explanation of holography

    NASA Astrophysics Data System (ADS)

    Weiss, Moshe

    1981-01-01

    The article has a threefold purpose: (i) to demonstrate the validity of the reversal principle for wave phenomena as interference and diffraction, (ii) to use this principle to explain holography even to students unacquainted with waves and (iii) to demonstrate a teaching method which is also appropriate for disadvantaged students. The GIREP conference held in summer 1979 on 'Waves' and on 'Teaching physics to disadvantaged students' recommended inter alia in its summary on waves to 'pull down' to secondary school level topics from recent developments in physics and, on the disadvantaged, to lower the level of abstraction required in learning.

  10. Dark field electron holography for strain measurement.

    PubMed

    Béché, A; Rouvière, J L; Barnes, J P; Cooper, D

    2011-02-01

    Dark field electron holography is a new TEM-based technique for measuring strain with nanometer scale resolution. Here we present the procedure to align a transmission electron microscope and obtain dark field holograms as well as the theoretical background necessary to reconstruct strain maps from holograms. A series of experimental parameters such as biprism voltage, sample thickness, exposure time, tilt angle and choice of diffracted beam are then investigated on a silicon-germanium layer epitaxially embedded in a silicon matrix in order to obtain optimal dark field holograms over a large field of view with good spatial resolution and strain sensitivity. PMID:21333860

  11. Results and further experiments using Spacelab holography

    NASA Technical Reports Server (NTRS)

    Owen, R. B.; Kroes, R. L.; Witherow, W. K.

    1986-01-01

    Spacelab 3 provided the platform for the first extensive application of holography in space. Holograms of excellent quality were recorded during the flight, providing information on the solution growth of triglycine sulfate crystals under microgravity conditions. The suppression of convection and the development of a symmetric concentration-depletion region around each crystal were clearly shown. Crystal growth was governed by diffusion mass transport across the depletion region. The successful performance of the holographic unit has prompted NASA to schedule a slightly modified version for reflight on IML-1; opportunities now exist for other investigators to use this facility.

  12. Art of color holography: pioneers in change

    NASA Astrophysics Data System (ADS)

    Richardson, Martin J.; Bjelkhagen, Hans I.

    2000-10-01

    The possibility to easily record full color holograms, (simply color holograms) has opened new possibilities for art holographers. This paper includes details concerning preparation of subject matter and its practical suitability for color holographic recordings from practical working sessions at ARTCAPI Atelier de Recherche Technique et de Creation Artistique en Physique et en Informatique in France. Martin Richardson as invited artist and Hans Bjelkhagen as scientist holographer describe color holography to a wider public audience through artistic display. Both directly recorded true color images and computer-generated images based on the ZEBRA printing technique are to be presented.

  13. Living human face measurements using pulsed holography

    NASA Astrophysics Data System (ADS)

    Bongartz, Jens; Giel, Dominik M.; Hering, Peter

    2000-10-01

    A method to measure precisely the 2D portrait of patients undergoing maxillofacial surgery based on holography is presented. We record holograms of patients with a pulsed Nd:YLF laser system on high resolution photographic glass plates. These images contain the 3D spatial information which, due to the extremely short recording time, is not affected at all by involuntary movements. The reconstructed real image of the hologram is sliced into a series of 2D projections by means of a screen. A first approach to reconstruct the patient's 3D surface information from the captured data set is presented.

  14. "Kunstwerk" in the age of holography

    NASA Astrophysics Data System (ADS)

    Öhlmann, Dietmar; Meulien Ohlmann, Odile

    2013-02-01

    In 2007 one auction shocked collectors and artists: Two art works of Rudie Berkhout were offered for one thousand dollars on eBay. The closing down of museums for holography in Cologne, New York and Washington DC paid a big price of respect for true art. Benjamin's vision about "Art in the Age of Mechanical Reproduction" found a new expression in abuse and ignorance. Beautiful sculptures of Art are reduced to "Holograms" like Rudie's "Cairo Aspect" placed in a rummage sale, covered by fingerprints of ignorance.

  15. Electron holography for fields in solids: problems and progress.

    PubMed

    Lichte, Hannes; Börrnert, Felix; Lenk, Andreas; Lubk, Axel; Röder, Falk; Sickmann, Jan; Sturm, Sebastian; Vogel, Karin; Wolf, Daniel

    2013-11-01

    Electron holography initially was invented by Dennis Gabor for solving the problems raised by the aberrations of electron lenses in Transmission Electron Microscopy. Nowadays, after hardware correction of aberrations allows true atomic resolution of the structure, for comprehensive understanding of solids, determination of electric and magnetic nanofields is the most challenging task. Since fields are phase objects in the TEM, electron holography is the unrivaled method of choice. After more than 40 years of experimental realization and steady improvement, holography is increasingly contributing to these highly sophisticated and essential questions in materials science, as well to the understanding of electron waves and their interaction with matter. PMID:23831133

  16. Chronic hypercapnia enhances V sub max of Na-H antiporter of renal brush-border membranes

    SciTech Connect

    Talor, Z.; Yang, Wuchang; Shuffield, J.; Sack, E.; Arruda, J.A.L. )

    1987-09-01

    Chronic hypercapnia is associated with increased proximal HCO{sub 3} reabsorption that is thought to be mediated by a Na-H antiporter. The authors hypothesized that chronic hypercapnia would be associated either with increased V{sub max} or with decreased K{sub m} of the Na-H antiporter. To test this hypothesis they made rabbits hypercapnic for 48 h by exposure to 10% CO{sub 2}. In both control and hypercapnic animals, cortical luminal membranes were enriched over the homogenate 16-fold in alkaline phosphatase and 10-fold in maltase activity. The kinetic activity of the Na-H antiporter was measured by the dissipation of the quenching of acridine orange by addition of different Na concentrations. Chronic hypercapnic rabbits had significantly higher V{sub max} of the Na-H antiporter of luminal membranes than controls. The K{sub m}, however, was not different between control and hypercapnic rabbits. {sup 22}Na uptake in presence of an outwardly directed pH gradient was significantly higher in vesicles from hypercapnic rabbits than controls. Amiloride inhibited the Na-H antiporter (as assessed by acridine orange quenching or {sup 22}Na uptake) to the same degree in membranes from both control and hypercapnic rabbits. The uptake of D-({sup 3}H)glucose by luminal membranes was not different between control and hypercapnic rabbits, indicating a specific enhancement of the Na-H antiporter. Thus chronic hypercapnia, but not acute hypercapnia, induces a selective and specific increase in the V{sub max} of Na-H antiporter, and this may mediate the adaptation to chronic hypercapnia.

  17. Massively parallel X-ray holography

    SciTech Connect

    Spence, John C.H; Marchesini, Stefano; Boutet, Sebastien; Sakdinawat, Anne E.; Bogan, Michael J.; Bajt, Sasa; Barty, Anton; Chapman, Henry N.; Frank, Matthias; Hau-Riege, Stefan P.; Szöke, Abraham; Cui, Congwu; Shapiro, David A.; Howells, MAlcolm R.; Shaevitz, Joshua W; Lee, Joanna Y.; Hajdu, Janos; Seibert, Marvin M.

    2008-08-01

    Advances in the development of free-electron lasers offer the realistic prospect of nanoscale imaging on the timescale of atomic motions. We identify X-ray Fourier-transform holography1,2,3 as a promising but, so far, inefficient scheme to do this. We show that a uniformly redundant array4 placed next to the sample, multiplies the efficiency of X-ray Fourier transform holography by more than three orders of magnitude, approaching that of a perfect lens, and provides holographic images with both amplitude- and phase-contrast information. The experiments reported here demonstrate this concept by imaging a nano-fabricated object at a synchrotron source, and a bacterial cell with a soft-X-ray free-electron laser, where illumination by a single 15-fs pulse was successfully used in producing the holographic image. As X-ray lasers move to shorter wavelengths we expect to obtain higher spatial resolution ultrafast movies of transient states of matter

  18. Simulated electron holography of PSD particles

    NASA Astrophysics Data System (ADS)

    Conbhuí, Pádraig Ó.; Williams, Wyn; Nagy, Les

    2016-04-01

    Electron holography is an experimental technique that is capable of observing magnetic microstructures on the same scale as can be determined using numerical modeling and thus bridge the gap between experimental measurements and theory. I will present a technique for simulating holographic images from the results of micromagnetic models and demonstrate an easily used tool for generating holograms on the fly in an interactive environment (ie in ParaView). Since holography flattens 3D information onto a 2D image, some useful information can be lost. By looking at some examples of holograms of interesting 3D magnetizations (ie PSD structures), particularly how they change as they're rotated, along with comparisons of different structures, I will examine what information can be retrieved and what might be lost. The existance of an external dipole can be indicative of an in-plane component of a seemingly out-of-plane vortex core. It is also seen, however, that two quite different structures (in this case a [111] vortex core and a [111] uniform magnetization) can sometimes be quite indistinguishable.

  19. Digital holography system for topography measurement

    NASA Astrophysics Data System (ADS)

    Amezquita, R.; Rincon, O. J.; Torres, Y. M.; Amezquita, S.

    2011-08-01

    The optical characteristics of Diffractive Optical Elements are determined by the properties of the photosensitive film on which they are produced. When working with photoresist plates, the most important property is the change in the plate's topography for different exposures. In this case, the required characterization involves a topographic measurement that can be made using digital holography. This work presents a digital holography system in which a hologram's phase map is obtained from a single recorded image. The phase map is calculated by applying a phase-shifting algorithm to a set of images that are created using a digital phase-shifting/tilteliminating procedure. Also, the curvatures, introduced by the imaging elements used in the experimental setup, are digitally compensated for using a polynomial fitting-method. The object's topography is then obtained from this modified phase map. To demonstrate the proposed procedure, the topography of patches exposed on a Shipley 1818 photoresist plate by microlithography equipment-which is currently under construction-is shown.

  20. High-resolution imaging using endoscopic holography

    NASA Astrophysics Data System (ADS)

    Bjelkhagen, Hans I.

    1990-08-01

    Endoscopic holography or endoholography combines the features of endoscopy and holography. The purpose of endoholographic imaging is to provide the physician with a unique means of extending diagnosis by providing a life-like record of tissue. Endoholographic recording will provide means for microscopic examination of tissue and in some cases may obviate the need to excise specimens for biopsy. In this method holograms which have the unique properties of three-dimensionality large focal depth and high resolution are made with a newly designed endoscope. The endoscope uses a single-mode optical fiber for illumination and single-beam reflection holograms are recorded in close contact with the tissue at the distal end of the endoscope. The holograms are viewed under a microscope. By using the proper combinations of dyes for staining specific tissue types with various wavelengths of laser illumination increased contrast on the cellular level can be obtained. Using dyes such as rose bengal in combination with the 514. 5 nm line of an argon ion laser and trypan blue or methylene blue with the 647. 1 nm line of a krypton ion laser holograms of the stained colon of a dog showed the architecture of the colon''s columnar epithelial cells. It is hoped through chronological study using this method in-vivo an increased understanding of the etiology and pathology of diseases such as Crohn''s diseases colitis proctitis and several different forms of cancer will help to their control. 1.

  1. Introductory overview of holography and speckle

    NASA Astrophysics Data System (ADS)

    Parker, David E.

    1990-10-01

    The purpose of this paper is to provide a nonmathematical overview of holographic and speckle interferometry. This provides information necessary for those participants with little or no background in these areas to understand the application papers in the Holography Speckle session of ICALEO''89. Holography A hologram is an optical device which is capable of producing threedimensional images. The word hologram stems from the Greek root holos which means whole complete or entire and the word gram which means message. Thus a hologram is a complete record of a scene or object. The first hologram was produced by Dennis Gabor in 1948. In 1971 he won the Nobel Prize for his work. Leith and Upatnieks produced the first holograms using a laser in the early 1960''s. In conventional photography the light reflected from a scene is focused by a camera lens onto a photographic emulsion. The variation in irradiance of the light reaching the emulsion is related only to the amplitude of the electric field due to the light. To produce three-dimensional images a hologram records information about both the amplitude and phase of light reflected from a scene or object. Production Hologram Figure 1 is a sketch of a system which can be used to produce optical holograms. A laser operating in the TEM mode is used as a light source. A continuous wave or a pulsed laser can be

  2. Acoustic Neuroma

    MedlinePlus

    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 ...

  3. Acoustic Seal

    NASA Technical Reports Server (NTRS)

    Steinetz, Bruce M. (Inventor)

    2006-01-01

    The invention relates to a sealing device having an acoustic resonator. The acoustic resonator is adapted to create acoustic waveforms to generate a sealing pressure barrier blocking fluid flow from a high pressure area to a lower pressure area. The sealing device permits noncontacting sealing operation. The sealing device may include a resonant-macrosonic-synthesis (RMS) resonator.

  4. Acoustic seal

    NASA Technical Reports Server (NTRS)

    Steinetz, Bruce M. (Inventor)

    2006-01-01

    The invention relates to a sealing device having an acoustic resonator. The acoustic resonator is adapted to create acoustic waveforms to generate a sealing pressure barrier blocking fluid flow from a high pressure area to a lower pressure area. The sealing device permits noncontacting sealing operation. The sealing device may include a resonant-macrosonic-synthesis (RMS) resonator.

  5. Real-time holography on bacteriorhodopsin-based materials

    NASA Astrophysics Data System (ADS)

    Taranenko, Victor B.

    1998-09-01

    The main properties and mechanisms of photoresponse of the bacteriohodopsin-based materials are presented. Fields of their potential applications in the real-time holography and nonlinear optics are discussed.

  6. Theoretical scheme for simultaneously observing forward-backward photoelectron holography.

    PubMed

    Du, Hongchuan; Wu, Hongmei; Wang, Huiqiao; Yue, Shengjun; Hu, Bitao

    2016-02-15

    Photoelectron angular momentum distribution of He+ driven by a few-cycle laser is investigated numerically. We simultaneously observe two dominant interference patterns with one shot of lasers by solving the 3D time-dependent Schrodinger equation. Analysis of a semiclassical model identifies these two interference patterns as two types of photoelectron holography. The interference pattern with Pz0 is a type of forward rescattering holography, which comes from the interference between direct (reference) and rescattered (signal) forward electrons ionized in the same quarter-cycle. The interference pattern with Pz<0 is a type of backward rescattering holography, which comes from the interference between a direct electron ionized in the third quarter-cycle and rescattered backward electron ionized in the first quarter-cycle. Moreover, we propose a method to distinguish this backward rescattering holography and intracycle interference patterns of direct electrons. PMID:26872166

  7. Absorbing New Subjects: Holography as an Analog of Photography

    NASA Astrophysics Data System (ADS)

    Johnston, Sean F.

    2006-05-01

    I discuss the early history of holography and explore how perceptions, applications, and forecasts of the subject were shaped by prior experience. I focus on the work of Dennis Gabor (1900 1979) in England,Yury N. Denisyuk (b. 1924) in the Soviet Union, and Emmett N. Leith (1927 2005) and Juris Upatnieks (b. 1936) in the United States. I show that the evolution of holography was simultaneously promoted and constrained by its identification as an analog of photography, an association that influenced its assessment by successive audiences of practitioners, entrepreneurs, and consumers. One consequence is that holography can be seen as an example of a modern technical subject that has been shaped by cultural influences more powerfully than generally appreciated. Conversely, the understanding of this new science and technology in terms of an older one helps to explain why the cultural effects of holography have been more muted than anticipated by forecasters between the 1960s and 1990s.

  8. NaHS Protects Cochlear Hair Cells from Gentamicin-Induced Ototoxicity by Inhibiting the Mitochondrial Apoptosis Pathway

    PubMed Central

    Dong, Yaodong; Liu, Dongliang; Hu, Yue; Ma, Xiulan

    2015-01-01

    Aminoglycoside antibiotics such as gentamicin could cause ototoxicity in mammalians, by inducing oxidative stress and apoptosis in sensory hair cells of the cochlea. Sodium hydrosulfide (NaHS) is reported to alleviate oxidative stress and apoptosis, but its role in protecting aminoglycoside-induced hearing loss is unclear. In this study, we investigated the anti-oxidant and anti-apoptosis effect of NaHS in in vitro cultured House Ear Institute-Organ of Corti 1 (HEI-OC1) cells and isolated mouse cochlea. Results from cultured HEI-OC1 cells and cochlea consistently indicated that NaHS exhibited protective effects from gentamicin-induced ototoxicity, evident by maintained cell viability, hair cell number and cochlear morphology, reduced reactive oxygen species production and mitochondrial depolarization, as well as apoptosis activation of the intrinsic pathway. Moreover, in the isolated cochlear culture, NaHS was also demonstrated to protect the explant from gentamicin-induced mechanotransduction loss. Our study using multiple in vitro models revealed for the first time, the potential of NaHS as a therapeutic agent in protecting against aminoglycoside-induced hearing loss. PMID:26295804

  9. A chimeric vacuolar Na(+)/H(+) antiporter gene evolved by DNA family shuffling confers increased salt tolerance in yeast.

    PubMed

    Wu, Guangxia; Wang, Gang; Ji, Jing; Li, Yong; Gao, Hailing; Wu, Jiang; Guan, Wenzhu

    2015-06-10

    The vacuolar Na(+)/H(+) antiporter plays an important role in maintaining ionic homeostasis and the osmotic balance of the cell with the environment by sequestering excessive cytoplasmic Na(+) into the vacuole. However, the relatively low Na(+)/H(+) exchange efficiency of the identified Na(+)/H(+) antiporter could limit its application in the molecular breeding of salt tolerant crops. In this study, DNA family shuffling was used to create chimeric Na(+)/H(+) antiporters with improved transport activity. Two homologous Na(+)/H(+) antiporters from halophytes Salicornia europaea (SeNHX1) and Suaeda salsa (SsNHX1) were shuffled to generate a diverse gene library. Using a high-throughput screening system of yeast complementation, a novel chimeric protein SseNHX1 carrying 12 crossover positions and 2 point mutations at amino acid level was selected. Expression of SseNHX1 in yeast mutant exhibited approximately 46% and 22% higher salt tolerance ability in yeast growth test than that of SsNHX1and SeNHX1, respectively. Measurements of the ion contents demonstrated that SseNHX1 protein in yeast cells accumulated more Na(+) and slightly more K(+) than the parental proteins did. Furthermore, this chimera also conferred increased tolerance to LiCl and a similar tolerance to hygromycin B compared with the parental proteins in yeast. PMID:25784157

  10. Genetic and physiological association of diabetes susceptibility with raised Na+/H+ exchange activity.

    PubMed Central

    Morahan, G; McClive, P; Huang, D; Little, P; Baxter, A

    1994-01-01

    Insulin-dependent diabetes mellitus is a multigenic autoimmune disease, for which one of the best animal models is the nonobese diabetic (NOD) mouse strain. In both humans and NOD mice, major histocompatibility complex genes are implicated as risk factors in the disease process. Other susceptibility genes are also involved, and a number have been mapped in the mouse to specific chromosomal locations. To identify further susceptibility genes, diabetic backcross mice, produced after crossing NOD/Lt to the nondiabetic strains SJL and C57BL/6 (B6), were examined for markers not previously associated with disease susceptibility. Linkage was found to loci on chromosomes 4 and 14. Of the candidate loci on chromosome 4, the gene encoding the Na+/H+ exchanger-1, Nhe-1, was the most likely, since the NOD allele was different from that of both nondiabetic strains. NOD lymphocytes were found to have a higher level of Na+/H+ exchange activity than lymphocytes from either B6 or SJL mice. Since the chromosome 4 susceptibility gene is recessive, the B6 allele should prevent diabetes. This prediction was tested in fourth-generation backcross mice, selected for retention of the B6 allele at Nhe-1. Mice homozygous for Nhe-1 developed diabetes after cyclophosphamide treatment, but heterozygotes were largely protected from disease. These results implicate the Na+/H+ exchanger (antiporter) in the development of type 1 diabetes and may provide a screening test for at-risk individuals as well as offering prospects for disease prevention. Images PMID:8016086

  11. Functional comparison of plasma-membrane Na+/H+ antiporters from two pathogenic Candida species

    PubMed Central

    Krauke, Yannick; Sychrova, Hana

    2008-01-01

    Background The virulence of Candida species depends on many environmental conditions. Extracellular pH and concentration of alkali metal cations belong among important factors. Nevertheless, the contribution of transporters mediating the exchange of alkali metal cations for protons across the plasma membrane to the cell salt tolerance and other physiological properties of various Candida species has not been studied so far. Results The tolerance/sensitivity of four pathogenic Candida species to alkali metal cations was tested and the role of one of the cation transporters in that tolerance (presumed to be the plasma-membrane Na+/H+ antiporter) was studied. The genes encoding these antiporters in the most and least salt sensitive species, C. dubliniensis and C. parapsilosis respectively, were identified, cloned and functionally expressed in the plasma membranes of Saccharomyces cerevisiae cells lacking their own cation exporters. Both CpCnh1 and CdCnh1 antiporters had broad substrate specificity and transported Na+, K+, Li+, and Rb+. Their activity in S. cerevisiae cells differed; CpCnh1p provided cells with a much higher salt tolerance than the CdCnh1 antiporter. The observed difference in activity was confirmed by direct measurements of sodium and potassium efflux mediated by these antiporters. Conclusion We have cloned two genes encoding putative Na+/H+ antiporters in C. parapsilosis and C. dubliniensis, and characterized the transport properties of encoded proteins. Our results show that the activity of plasma-membrane Na+/H+ antiporters is one of the factors determining the tolerance of pathogenic Candida species to high external concentrations of alkali metal cations. PMID:18492255

  12. Particle and flow field holography: A critical survey

    NASA Technical Reports Server (NTRS)

    Trolinger, James D.

    1987-01-01

    A brief background is provided for the fields of particle and flow visualization holography. A summary of methods currently in use is given, followed by a discussion of more recent and unique applications. The problem of data reduction is discussed. A state of the art summary is then provided with a prognosis of the future of the field. Particle and flow visualization holography are characterized as powerful tools currently in wide use and with significant untapped potential.

  13. New goals of the German Association for Holography, DGH

    NASA Astrophysics Data System (ADS)

    Ohlmann, Dietmar; Moeller, Niklas; Meulien-Ohlmann, Odile

    1998-02-01

    The explosion of the holography display has now to be expressed at the past, but a new generation of people, especially the young one and specialists working in research institutions push the information on holography to be spread. This is why, after a phase of stagnation, and who says stagnation says restriction, the DGH with its new board of directors is ready to answer this new need.

  14. NHX-5, an Endosomal Na+/H+ Exchanger, Is Associated with Metformin Action.

    PubMed

    Kim, Jeongho; Lee, Hye-Yeon; Ahn, Jheesoo; Hyun, Moonjung; Lee, Inhwan; Min, Kyung-Jin; You, Young-Jai

    2016-08-26

    Diabetes is one of the most impactful diseases worldwide. The most commonly prescribed anti-diabetic drug is metformin. In this study, we identified an endosomal Na(+)/H(+) exchanger (NHE) as a new potential target of metformin from an unbiased screen in Caenorhabditis elegans The same NHE homolog also exists in flies, where it too mediates the effects of metformin. Our results suggest that endosomal NHEs could be a metformin target and provide an insight into a novel mechanism of action of metformin on regulating the endocytic cycle. PMID:27435670

  15. Population transfer of a NaH molecule via stimulated Raman adiabatic passage

    NASA Astrophysics Data System (ADS)

    Zai, Jing-Bo; Zhan, Wei-Shen; Wang, Shuo; Dang, Hai-Ping; Han, Xiao

    2016-09-01

    The population transfer of a NaH molecule from the ground state {{X}1}{Σ+} to the target state {{A}1}{Σ+} via stimulated Raman adiabatic passage (STIRAP) is investigated. The results show that the intensity, delay time and detuning have a significant effect on population transfer. A large population transfer is observed with increased pump and Stokes intensity, especially when the pump and Stokes intensity match. Population transfer also depends on the delay time between the pump laser pulse and the Stokes laser pulse. The detuning of the two pulses influences the population transfer. Efficient population transfer can be realized under the resonant or two-photon resonant condition.

  16. Neural-net Processed Electronic Holography for Rotating Machines

    NASA Technical Reports Server (NTRS)

    Decker, Arthur J.

    2003-01-01

    This report presents the results of an R&D effort to apply neural-net processed electronic holography to NDE of rotors. Electronic holography was used to generate characteristic patterns or mode shapes of vibrating rotors and rotor components. Artificial neural networks were trained to identify damage-induced changes in the characteristic patterns. The development and optimization of a neural-net training method were the most significant contributions of this work, and the training method and its optimization are discussed in detail. A second positive result was the assembly and testing of a fiber-optic holocamera. A major disappointment was the inadequacy of the high-speed-holography hardware selected for this effort, but the use of scaled holograms to match the low effective resolution of an image intensifier was one interesting attempt to compensate. This report also discusses in some detail the physics and environmental requirements for rotor electronic holography. The major conclusions were that neural-net and electronic-holography inspections of stationary components in the laboratory and the field are quite practical and worthy of continuing development, but that electronic holography of moving rotors is still an expensive high-risk endeavor.

  17. Simultaneous Conoscopic Holography and Raman Spectroscopy

    NASA Technical Reports Server (NTRS)

    Schramm, Harry F.; Kaiser, Bruce

    2005-01-01

    A new instrument was developed for chemical characterization of surfaces that combines the analytical power of Raman spectroscopy with the three-dimensional topographic information provided by conoscopic holography. The figure schematically depicts the proposed hybrid instrument. The output of the conoscopic holographic portion of the instrument is a topographical map of the surface; the output of the Raman portion of the instrument is hyperspectral Raman data, from which the chemical and/or biological composition of the surface would be deduced. By virtue of the basic principles of design and operation of the instrument, the hyperspectral image data would be inherently spatially registered with the topographical data. In conoscopic holography, the object and reference beams of classical holography are replaced by the ordinary and extraordinary components generated by a single beam traveling through a birefringent, uniaxial crystal. In the basic conoscopic configuration, a laser light is projected onto a specimen and the resulting illuminated spot becomes a point source of diffuse light that propagates in every direction. The laser beam is rasterscanned in two dimensions (x and y) perpendicular to the beam axis (z), and at each x,y location, the pattern of interference between the ordinary and extraordinary rays is recorded. The recorded interferogram constitutes the conoscopic hologram. Of particular significance for the proposed instrument is that the conoscopic hologram contains information on the z coordinate (height) of the illuminated surface spot. Hence, a topographical map of the specimen is constructed point-by-point by rastering the laser beam in the x and y directions and correlating the x and y coordinates with the z information obtained from the interferograms. Conoscopic imaging is an established method, and conoscopic laboratory instruments for surface metrology are commercially available. In Raman spectroscopy of a surface, one measures the spectrum

  18. Acoustic sources' localization in presence of reverberation

    NASA Astrophysics Data System (ADS)

    Julliard, E.; Pauzin, S.; Simon, F.; Biron, D.

    2005-09-01

    For several years, aeronautical industries have wished to improve internal acoustical comfort. In order to make it, they need metrological tools which are able to help them to spot acoustical sources and the associated path in a specific frequency range (i.e., for helicopters' internal noise: 1000-5000 Hz). Two major source' localization' tools exist: holography and beamforming, but these two techniques are based on a free field's hypothesis. So, problems appear when these techniques are used in a reverberant medium. This paper deals with the study and the comparison of holography and beamforming results in an enclosed area. To complete the study, intensimetry is also implemented to have information on the energy propagation. In order to test the performances of each method, two reflecting panels are put at right angles to create a reverberant environment, in an anechoic chamber. We seek to locate loudspeakers clamped in one panel, in the presence of parasite loudspeakers located on the other one. Then, a parametrical study is led: localization and number of sources, coherent or noncoherent sources. Thus, using limitations, precautions to take, and a base of comparison three methods are put forward. Finally, some envisaged solutions to limit problems of reflections (signal processing, overturning, etc.) are presented.

  19. Coordinated control of volume regulatory Na+/H+ and K+/H+ exchange pathways in Amphiuma red blood cells.

    PubMed

    Ortiz-Acevedo, Alejandro; Rigor, Robert R; Maldonado, Hector M; Cala, Peter M

    2010-03-01

    The Na(+)/H(+) and K(+)/H(+) exchange pathways of Amphiuma tridactylum red blood cells (RBCs) are quiescent at normal resting cell volume yet are selectively activated in response to cell shrinkage and swelling, respectively. These alkali metal/H(+) exchangers are activated by net kinase activity and deactivated by net phosphatase activity. We employed relaxation kinetic analyses to gain insight into the basis for coordinated control of these volume regulatory ion flux pathways. This approach enabled us to develop a model explaining how phosphorylation/dephosphorylation-dependent events control and coordinate the activity of the Na(+)/H(+) and K(+)/H(+) exchangers around the cell volume set point. We found that the transition between initial and final steady state for both activation and deactivation of the volume-induced Na(+)/H(+) and K(+)/H(+) exchange pathways in Amphiuma RBCs proceed as a single exponential function of time. The rate of Na(+)/H(+) exchange activation increases with cell shrinkage, whereas the rate of Na(+)/H(+) exchange deactivation increases as preshrunken cells are progressively swollen. Similarly, the rate of K(+)/H(+) exchange activation increases with cell swelling, whereas the rate of K(+)/H(+) exchange deactivation increases as preswollen cells are progressively shrunken. We propose a model in which the activities of the controlling kinases and phosphatases are volume sensitive and reciprocally regulated. Briefly, the activity of each kinase-phosphatase pair is reciprocally related, as a function of volume, and the volume sensitivities of kinases and phosphatases controlling K(+)/H(+) exchange are reciprocally related to those controlling Na(+)/H(+) exchange. PMID:19940069

  20. Remote metrology by comparative digital holography

    SciTech Connect

    Baumbach, Torsten; Osten, Wolfgang; Kopylow, Christoph von; Jueptner, Werner

    2006-02-10

    A method for the remote comparison of objects with regard to their shape or response to a load is presented. The method allows interferometric sensitivity for comparing objects with different microstructure. In contrast to the well-known incoherent techniques based on inverse fringe projection this new approach uses the coherent optical wave field of the master object as a mask for the illumination of the sample object. The coherent mask is created by digital holography to allow instant access to the complete optical information of the master object at any place desired. The mask is reconstructed by a spatial light modulator (SLM). The optical reconstruction of digital holograms with SLM technology allows modification of reconstructed wavefronts with respect to improvement of image quality, the skilled introduction of additional information about the object (augmented reality), and the alignment of the master and test object.

  1. Industrial Holography - The Rolls-Royce Experience

    NASA Astrophysics Data System (ADS)

    Parker, R. J.; Jones, D. G.

    1987-10-01

    Holographic interferometry has provided the engineer with one of the most powerful and versatile measurement tools of the twentieth century. It seems only natural that such a technique should have found widespread application in the aero-engine industry. The quest for ever more fuel-efficient gas-turbine engines is constantly stretching and extending the frontiers of technology. It creates an increasing need for understanding of the mechanical and aerodynamic behaviour of components under extreme conditions. Holography has recently achieved new importance as a means of providing the data necessary for the development and validation of computer models. Increasingly, design work is being performed by the application of complicated three-dimensional computer models to gas flow prediction and the use of finite-element models for the investigation of mechanical behaviour and stress.

  2. Quantum probabilities for inflation from holography

    NASA Astrophysics Data System (ADS)

    Hartle, James B.; Hawking, S. W.; Hertog, Thomas

    2014-01-01

    The evolution of the universe is determined by its quantum state. The wave function of the universe obeys the constraints of general relativity and in particular the Wheeler-DeWitt equation (WDWE). For non-zero Λ, we show that solutions of the WDWE at large volume have two domains in which geometries and fields are asymptotically real. In one the histories are Euclidean asymptotically anti-de Sitter, in the other they are Lorentzian asymptotically classical de Sitter. Further, the universal complex semiclassical asymptotic structure of solutions of the WDWE implies that the leading order in hbar quantum probabilities for classical, asymptotically de Sitter histories can be obtained from the action of asymptotically anti-de Sitter configurations. This leads to a promising, universal connection between quantum cosmology and holography.

  3. X-ray holography in-flight

    NASA Astrophysics Data System (ADS)

    Gorkhover, Tais; Ulmer, Anatoli; Ferguson, Ken; Bucher, Max; Ekeberg, Tomas; Hantke, Max; Daurer, Benedikt; Nettelblad, Carl; Bielecki, Johan; Faigel, Guila; Hasse, Dirk; Morgan, Andrew; Mühlig, Kerstin; Seibert, Marvin; Chapman, Henry; Hajdu, Janos; Maia, Filipe; Moeller, Thomas; Bostedt, Christoph

    2016-05-01

    The advent of X-ray free-electron lasers, delivering ultra intense femtosecond X-ray flashes, opens the door for structure determination of single nanoparticles and biosamples with single shots. The first X-ray diffraction imaging experiments at LCLS delivered promising results on samples in the gas phase. However, the reconstruction of non-periodic structures is still challenging due to the loss of phase information. Meanwhile, X-ray holographic approaches allow for recording the phase directly into the diffraction image. In my talk, I will present the first successful proof-of-principle experiment for ``in-flight''-holography with free viruses. Our experiments pave the way for unique studies on levitating nanospecimen that are of central interest in several scientific communities including atmosphere research, chemistry, material sciences, and studies on matter under extreme conditions.

  4. Study of clarinet reeds using digital holography

    NASA Astrophysics Data System (ADS)

    Stetson, Karl A.

    2014-11-01

    A study of clarinet reeds demonstrates the capabilities of digital holography for identification and measurement of vibration modes, measurement of static displacement and creep, and measurement of shape profile. Three types of synthetic reeds were examined together with a number of cane reeds both wet and dry. It is shown that the synthetic reeds have fundamental vibration mode frequencies that are lower than those of natural cane reeds. The fundamental modes of cane reeds all lie above the range of notes played by the instrument whereas those of synthetic reeds do not. Examination of static displacements due to steady air flow showed creep effects due to inelasticity. Finally, projected fringes were used to measure the reed profile.

  5. Entanglement entropy in higher derivative holography

    NASA Astrophysics Data System (ADS)

    Bhattacharyya, Arpan; Kaviraj, Apratim; Sinha, Aninda

    2013-08-01

    We consider holographic entanglement entropy in higher derivative gravity theories. Recently Lewkowycz and Maldacena [1] have provided a method to derive the equations for the entangling surface from first principles. We use this method to compute the entangling surface in four derivative gravity. Certain interesting differences compared to the two derivative case are pointed out. For Gauss-Bonnet gravity, we show that in the regime where this method is applicable, the resulting equations coincide with proposals in the literature as well as with what follows from considerations of the stress tensor on the entangling surface. Finally we demonstrate that the area functional in Gauss-Bonnet holography arises as a counterterm needed to make the Euclidean action free of power law divergences.

  6. Holography of 3D flat cosmological horizons.

    PubMed

    Bagchi, Arjun; Detournay, Stéphane; Fareghbal, Reza; Simón, Joan

    2013-04-01

    We provide a first derivation of the Bekenstein-Hawking entropy of 3D flat cosmological horizons in terms of the counting of states in a dual field theory. These horizons appear in the flat limit of nonextremal rotating Banados-Teitleboim-Zanelli black holes and are remnants of the inner horizons. They also satisfy the first law of thermodynamics. We study flat holography as a limit of AdS(3)/CFT(2) to semiclassically compute the density of states in the dual theory, which is given by a contraction of a 2D conformal field theory, exactly reproducing the bulk entropy in the limit of large charges. We comment on how the dual theory reproduces the bulk first law and how cosmological bulk excitations are matched with boundary quantum numbers. PMID:25166977

  7. Direct-to-digital holography and holovision

    DOEpatents

    Thomas, Clarence E.; Baylor, Larry R.; Hanson, Gregory R.; Rasmussen, David A.; Voelkl, Edgar; Castracane, James; Simkulet, Michelle; Clow, Lawrence

    2000-01-01

    Systems and methods for direct-to-digital holography are described. An apparatus includes a laser; a beamsplitter optically coupled to the laser; a reference beam mirror optically coupled to the beamsplitter; an object optically coupled to the beamsplitter, a focusing lens optically coupled to both the reference beam mirror and the object; and a digital recorder optically coupled to the focusing lens. A reference beam is incident upon the reference beam mirror at a non-normal angle, and the reference beam and an object beam are focused by the focusing lens at a focal plane of the digital recorder to form an image. The systems and methods provide advantages in that computer assisted holographic measurements can be made.

  8. Quantum probabilities for inflation from holography

    SciTech Connect

    Hartle, James B.; Hawking, S.W.; Hertog, Thomas E-mail: S.W.Hawking@damtp.cam.ac.uk

    2014-01-01

    The evolution of the universe is determined by its quantum state. The wave function of the universe obeys the constraints of general relativity and in particular the Wheeler-DeWitt equation (WDWE). For non-zero Λ, we show that solutions of the WDWE at large volume have two domains in which geometries and fields are asymptotically real. In one the histories are Euclidean asymptotically anti-de Sitter, in the other they are Lorentzian asymptotically classical de Sitter. Further, the universal complex semiclassical asymptotic structure of solutions of the WDWE implies that the leading order in h-bar quantum probabilities for classical, asymptotically de Sitter histories can be obtained from the action of asymptotically anti-de Sitter configurations. This leads to a promising, universal connection between quantum cosmology and holography.

  9. Holography in museums of the Ukraine

    NASA Astrophysics Data System (ADS)

    Markov, Vladimir B.; Mironyuk, G. I.

    1991-02-01

    The capability of a hologram to reproduce the three-dimensional image of a real objects - its optical replica, atracts attention of specialists engaged in different domains of science and engineering. Holographic methods for image formation are rather interesting for medicine and biology, for systems of visual information representation (in making versatile simulator, for example) and for facilities of non-destructive testing of units and mechanisms, for simulation, etc. Applications of holography to museum practice seems to be rather promising. In this case holographic methods may be quite timely both as a means of visual information imaging and as a means capable of appreciably raising and improving the state of technical equipment of present-day museums.

  10. In vitro functional characterization of the Na+/H+ antiporters in Corynebacterium glutamicum.

    PubMed

    Xu, Ning; Wang, Lei; Cheng, Haijiao; Liu, Qingdai; Liu, Jun; Ma, Yanhe

    2016-02-01

    Corynebacterium glutamicum, typically used as industrial workhorse for amino acid production, is a moderately salt-alkali-tolerant microorganism with optimal growth at pH 7-9. However, little is known about the mechanisms of salt-alkali tolerance in C. glutamicum. Here, the catalytic capacity of three putative Na(+)/H(+) antiporters from C. glutamicum (designated as Cg-Mrp1, Cg-Mrp2 and Cg-NhaP) were characterized in an antiporter-deficient Escherichia coli KNabc strain. Only Cg-Mrp1 was able to effectively complement the Na(+)-sensitive of E. coli KNabc. Cg-Mrp1 exhibited obvious Na(+)(Li(+))/H(+) antiport activities with low apparent Km values of 1.08 mM and 1.41 mM for Na(+) and Li(+), respectively. The Na(+)/H(+) antiport activity of Cg-Mrp1 was optimal in the alkaline pH range. All three antiporters showed detectable K(+)/H(+) antiport activitiy. Cg-NhaP also exhibited Na(+)(Li(+),Rb(+))/H(+) antiport activities but at lower levels of activity. Interestingly, overexpression of Cg-Mrp2 exhibited clear Na(+)(K(+))/H(+) antiport activities. These results suggest that C. glutamicum Na(+)(K(+))/H(+) antiporters may have overlapping roles in coping with salt-alkali and perhaps high-osmolarity stress. PMID:26667218

  11. Effects of the Electronic Doping In the Stability of the Metal Hydride NaH

    NASA Astrophysics Data System (ADS)

    Olea-Amezcua, Monica-Araceli; Rivas-Silva, Juan-Francisco; de La Peña-Seaman, Omar; Heid, Rolf; Bohnen, Klaus-Peter

    2015-03-01

    Despite metal hydrides light weight and high hydrogen volumetric densities, the Hydrogen desorption process requires excessively high temperatures due to their high stability. Attempts for improvement the hydrogenation properties have been focus on the introduction of defects, impurities and doping on the metal hydride. We present a systematic study of the electronic doping effects on the stability of a model system, NaH doped with magnesium, forming the alloying system Na1-xMgxH. We use the density functional theory (DFT) and the self-consistent version of the virtual crystal approximation (VCA) to model the doping of NaH with Mg. The evolution of the ground state structural and electronic properties is analyzed as a function of Mg-content. The full-phonon dispersion, calculated by the linear response theory (LRT) and density functional perturbation theory (DFPT), is analyzed for several Mg-concentrations, paying special attention to the crystal stability and the correlations with the electronic structure. Applying the quasiharmonic approximation (QHA), the free energy from zero-point motion is obtained, and its influence on the properties under study is analyzed. This work is partially supported by the VIEP-BUAP (OMPS-EXC14-I) and CONACYT-Mexico (No. 221807) projects.

  12. Topological Acoustics

    NASA Astrophysics Data System (ADS)

    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.

  13. Topological acoustics.

    PubMed

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

    2015-03-20

    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. PMID:25839273

  14. Acoustic neuroma

    MedlinePlus

    Vestibular schwannoma; Tumor - acoustic; Cerebellopontine angle tumor; Angle tumor ... 177. Battista RA. Gamma knife radiosurgery for vestibular schwannoma. Otolaryngol Clin North Am . 2009;42:635-654. ...

  15. Volumetric Acoustic Vector Intensity Probe

    NASA Technical Reports Server (NTRS)

    Klos, Jacob

    2006-01-01

    A new measurement tool capable of imaging the acoustic intensity vector throughout a large volume is discussed. This tool consists of an array of fifty microphones that form a spherical surface of radius 0.2m. A simultaneous measurement of the pressure field across all the microphones provides time-domain near-field holograms. Near-field acoustical holography is used to convert the measured pressure into a volumetric vector intensity field as a function of frequency on a grid of points ranging from the center of the spherical surface to a radius of 0.4m. The volumetric intensity is displayed on three-dimensional plots that are used to locate noise sources outside the volume. There is no restriction on the type of noise source that can be studied. The sphere is mobile and can be moved from location to location to hunt for unidentified noise sources. An experiment inside a Boeing 757 aircraft in flight successfully tested the ability of the array to locate low-noise-excited sources on the fuselage. Reference transducers located on suspected noise source locations can also be used to increase the ability of this device to separate and identify multiple noise sources at a given frequency by using the theory of partial field decomposition. The frequency range of operation is 0 to 1400Hz. This device is ideal for the study of noise sources in commercial and military transportation vehicles in air, on land and underwater.

  16. Production of Yarrowia lipolytica Nha2 Na+/H+ antiporter improves the salt tolerance of Saccharomyces cerevisiae.

    PubMed

    Papousková, K; Sychrová, H

    2007-01-01

    Yarrowia lipolytica plasma-membrane Na+/H+ antiporter, encoded by the YlNHA2 gene, is a very efficient exporter of surplus sodium from the cytosol. Its heterologous expression in Saccharomyces cerevisiae wild-type laboratory strains increased their sodium tolerance more efficiently than the expression of ZrSod2-22 antiporter from the osmotolerant yeast Zygosaccharomvces rouxii. PMID:18450222

  17. Regulation by salt of vacuolar H+-ATPase and H+-pyrophosphatase activities and Na+/H+ exchange

    PubMed Central

    Silva, Paulo

    2009-01-01

    Over the last decades several efforts have been carried out to determine the mechanisms of salt homeostasis in plants and, more recently, to identify genes implicated in salt tolerance, with some plants being successfully genetically engineered to improve resistance to salt. It is well established that the efficient exclusion of Na+ excess from the cytoplasm and vacuolar Na+ accumulation are the most important steps towards the maintenance of ion homeostasis inside the cell. Therefore, the vacuole of plant cells plays a pivotal role in the storage of salt. After the identification of the vacuolar Na+/H+ antiporter Nhx1 in Saccharomyces cerevisiae, the first plant Na+/H+ antiporter, AtNHX1, was isolated from Arabidopsis and its overexpression resulted in plants exhibiting increased salt tolerance. Also, the identification of the plasma membrane Na+/H+ exchanger SOS1 and how it is regulated by a protein kinase SOS2 and a calcium binding protein SOS3 were great achievements in the understanding of plant salt resistance. Both tonoplast and plasma membrane antiporters exclude Na+ from the cytosol driven by the proton-motive force generated by the plasma membrane H+-ATPase and by the vacuolar membrane H+-ATPase and H+-pyrophosphatase and it has been shown that the activity of these proteins responds to salinity. In this review we focus on the transcriptional and post-transcriptional regulation by salt of tonoplast proton pumps and Na+/H+ exchangers and on the signalling pathways involved in salt sensing. PMID:19820346

  18. Musical Acoustics

    NASA Astrophysics Data System (ADS)

    Gough, Colin

    This chapter provides an introduction to the physical and psycho-acoustic principles underlying the production and perception of the sounds of musical instruments. The first section introduces generic aspects of musical acoustics and the perception of musical sounds, followed by separate sections on string, wind and percussion instruments.

  19. Imaging of Acoustic Waves in Sand

    SciTech Connect

    Deason, Vance Albert; Telschow, Kenneth Louis; Watson, Scott Marshall

    2003-08-01

    There is considerable interest in detecting objects such as landmines shallowly buried in loose earth or sand. Various techniques involving microwave, acoustic, thermal and magnetic sensors have been used to detect such objects. Acoustic and microwave sensors have shown promise, especially if used together. In most cases, the sensor package is scanned over an area to eventually build up an image or map of anomalies. We are proposing an alternate, acoustic method that directly provides an image of acoustic waves in sand or soil, and their interaction with buried objects. The INEEL Laser Ultrasonic Camera utilizes dynamic holography within photorefractive recording materials. This permits one to image and demodulate acoustic waves on surfaces in real time, without scanning. A video image is produced where intensity is directly and linearly proportional to surface motion. Both specular and diffusely reflecting surfaces can be accomodated and surface motion as small as 0.1 nm can be quantitatively detected. This system was used to directly image acoustic surface waves in sand as well as in solid objects. Waves as frequencies of 16 kHz were generated using modified acoustic speakers. These waves were directed through sand toward partially buried objects. The sand container was not on a vibration isolation table, but sat on the lab floor. Interaction of wavefronts with buried objects showed reflection, diffraction and interference effects that could provide clues to location and characteristics of buried objects. Although results are preliminary, success in this effort suggests that this method could be applied to detection of buried landmines or other near-surface items such as pipes and tanks.

  20. One-photon Assisted Formation of Ultracold LiH and NaH

    NASA Astrophysics Data System (ADS)

    Juarros, Elizabeth; Kirby, Kate; Coté, Robin

    2006-05-01

    Alkali hydride molecules have large dipole moments in their ground electronic states. We explore the possibility of forming such molecules from a mixture of the ultracold atomic gases, employing a one-photon stimulated radiative association process. Using accurate molecular potential energy curves and dipole moments, we have calculated the rate coefficients for populating each of the vibrational levels of the X^1&+circ; state of LiH and NaH. We have found that significant molecule formation rates into the upper vibrational levels can be realized with laser intensities and MOT densities that are easily attainable experimentally. We examine the spontaneous emission cascade which takes place from these upper vibrational levels on a timescale of milliseconds, and calculate the resulting rotational populations in v=0. We show that photon emission in the cascade process does not contribute to trap loss.

  1. Practical holography IV; Proceedings of the Meeting, LOS Angeles, CA, Jan. 18, 19, 1990

    NASA Astrophysics Data System (ADS)

    Benton, Stephen A.

    1990-05-01

    Various papers on practical holography are presented. Individual topics addressed include: dichromated gelatin for holographic optical elements, novel enhancement of photopolymers, photopolymers for holography, new rehalogenating bleach for the production of Lippmann holograms, effects of bleach constituents on the performance of silver-halide holograms, highly sensitive positive resists for holography, holographic 3-D printer, generation of high-quality holograms with liquid-crystal SLM, display holography for medical tomography, 3-D display of ultrasound B-mode image by holographic stereogram, edge-lit rainbow holograms, electronic display system for computational holography, and DCG recording with red light. Also discussed are: corneal topography via two-wavelength holography, optically produced cylindrical HOEs for signal-processing applications, hybrid diffractive-refractive telescope, volume IR reflective gratings, holographic lithography for microcircuits, photorefractive waveguide grating switches for optical interconnects, non-Fourier computer-generated holography for 3-D display, phase selection in binary-phase-only filters for optical pattern recognition.

  2. Nax loci affect SOS1-like Na+/H+ exchanger expression and activity in wheat

    PubMed Central

    Zhu, Min; Shabala, Lana; Cuin, Tracey A; Huang, Xin; Zhou, Meixue; Munns, Rana; Shabala, Sergey

    2016-01-01

    Salinity stress tolerance in durum wheat is strongly associated with a plant’s ability to control Na+ delivery to the shoot. Two loci, termed Nax1 and Nax2, were recently identified as being critical for this process and the sodium transporters HKT1;4 and HKT1;5 were identified as the respective candidate genes. These transporters retrieve Na+ from the xylem, thus limiting the rates of Na+ transport from the root to the shoot. In this work, we show that the Nax loci also affect activity and expression levels of the SOS1-like Na+/H+ exchanger in both root cortical and stelar tissues. Net Na+ efflux measured in isolated steles from salt-treated plants, using the non-invasive ion flux measuring MIFE technique, decreased in the sequence: Tamaroi (parental line)>Nax1=Nax2>Nax1:Nax2 lines. This efflux was sensitive to amiloride (a known inhibitor of the Na+/H+ exchanger) and was mirrored by net H+ flux changes. TdSOS1 relative transcript levels were 6–10-fold lower in Nax lines compared with Tamaroi. Thus, it appears that Nax loci confer two highly complementary mechanisms, both of which contribute towards reducing the xylem Na+ content. One enhances the retrieval of Na+ back into the root stele via HKT1;4 or HKT1;5, whilst the other reduces the rate of Na+ loading into the xylem via SOS1. It is suggested that such duality plays an important adaptive role with greater versatility for responding to a changing environment and controlling Na+ delivery to the shoot. PMID:26585227

  3. Ontogeny of Na/H antiporter activity in rabbit renal brush border membrane vesicles.

    PubMed Central

    Beck, J C; Lipkowitz, M S; Abramson, R G

    1991-01-01

    The development of the Na/H antiporter was studied in renal brush border membrane vesicles (BBMV) from fetal and adult rabbits using isotopic and fluorescent techniques. The kinetics of the antiporter studied by 22Na+ uptake revealed that the Vmax was only 25% of that in the adult; however, the Km's for Na+ were not significantly different. These data were confirmed by a fluorescent assay using the pH-sensitive probe, acridine orange: the Vmax was significantly lower in the fetal BBMV. Conductive Na+ movement was estimated from amiloride-insensitive 22Na+ uptake and the rate of alkalinization induced by K+, an ion whose relative conductance was found to be similar to that of Na+. Although relative Na+ conductance was significantly greater in fetal BBMV, the lower Vmax in fetal vesicles could not be ascribed to this factor. Maternal administration of betamethasone (50 micrograms/kg intramuscularly) for 2 d before delivery significantly increased the Vmax of the antiporter to levels observed in the adult; Km was unaffected. Na/K ATPase activity increased fourfold after betamethasone, but the specific activities of four brush border marker enzymes and the kinetics of Na(+)-glucose cotransport were unchanged. These data indicate that there is a developmental increase in brush border Na/H exchange which is the result of an increase in the number and/or the turnover number of the carriers. Further, these data suggest that the postnatal increase in antiporter activity may be related to the surge in glucocorticoid concentration that occurs perinatally. Images PMID:1645751

  4. Proton motive force and Na+/H+ antiport in a moderate halophile.

    PubMed Central

    Hamaide, F; Kushner, D J; Sprott, G D

    1983-01-01

    The influence of pH on the proton motive force of Vibrio costicola was determined by measuring the distributions of triphenylmethylphosphonium cation (membrane potential, delta psi) and either dimethyloxazolidinedione or methylamine (osmotic component, delta pH). As the pH of the medium was adjusted from 5.7 to 9.0, the proton motive force steadily decreased from about 170 to 100 mV. This decline occurred, despite a large increase in the membrane potential to its maximum value at pH 9.0, because of the loss of the pH gradient (inside alkaline). The cytoplasm and medium were of equal pH at 7.5; membrane permeability properties were lost at the pH extremes of 5.0 and 9.5. Protonophores and monensin prevented the net efflux of protons normally found when an oxygen pulse was given to an anaerobic cell suspension. A Na+/H+ antiport activity was measured for both Na+ influx and efflux and was shown to be dissipated by protonophores and monensin. These results strongly favor the concept that respiratory energy is used for proton efflux and that the resulting proton motive force may be converted to a sodium motive force through Na+/H+ antiport (driven by delta psi). A role for antiport activity in pH regulation of the cytosol can also explain the broad pH range for optimal growth, extending to the alkaline extreme of pH 9.0. PMID:6313606

  5. Nax loci affect SOS1-like Na+/H+ exchanger expression and activity in wheat.

    PubMed

    Zhu, Min; Shabala, Lana; Cuin, Tracey A; Huang, Xin; Zhou, Meixue; Munns, Rana; Shabala, Sergey

    2016-02-01

    Salinity stress tolerance in durum wheat is strongly associated with a plant's ability to control Na(+) delivery to the shoot. Two loci, termed Nax1 and Nax2, were recently identified as being critical for this process and the sodium transporters HKT1;4 and HKT1;5 were identified as the respective candidate genes. These transporters retrieve Na(+) from the xylem, thus limiting the rates of Na(+) transport from the root to the shoot. In this work, we show that the Nax loci also affect activity and expression levels of the SOS1-like Na(+)/H(+) exchanger in both root cortical and stelar tissues. Net Na(+) efflux measured in isolated steles from salt-treated plants, using the non-invasive ion flux measuring MIFE technique, decreased in the sequence: Tamaroi (parental line)>Nax1=Nax2>Nax1:Nax2 lines. This efflux was sensitive to amiloride (a known inhibitor of the Na(+)/H(+) exchanger) and was mirrored by net H(+) flux changes. TdSOS1 relative transcript levels were 6-10-fold lower in Nax lines compared with Tamaroi. Thus, it appears that Nax loci confer two highly complementary mechanisms, both of which contribute towards reducing the xylem Na(+) content. One enhances the retrieval of Na(+) back into the root stele via HKT1;4 or HKT1;5, whilst the other reduces the rate of Na(+) loading into the xylem via SOS1. It is suggested that such duality plays an important adaptive role with greater versatility for responding to a changing environment and controlling Na(+) delivery to the shoot. PMID:26585227

  6. Near-field electromagnetic holography for high-resolution analysis of network interactions in neuronal tissue

    PubMed Central

    Kjeldsen, Henrik D.; Kaiser, Marcus; Whittington, Miles A.

    2015-01-01

    Background Brain function is dependent upon the concerted, dynamical interactions between a great many neurons distributed over many cortical subregions. Current methods of quantifying such interactions are limited by consideration only of single direct or indirect measures of a subsample of all neuronal population activity. New method Here we present a new derivation of the electromagnetic analogy to near-field acoustic holography allowing high-resolution, vectored estimates of interactions between sources of electromagnetic activity that significantly improves this situation. In vitro voltage potential recordings were used to estimate pseudo-electromagnetic energy flow vector fields, current and energy source densities and energy dissipation in reconstruction planes at depth into the neural tissue parallel to the recording plane of the microelectrode array. Results The properties of the reconstructed near-field estimate allowed both the utilization of super-resolution techniques to increase the imaging resolution beyond that of the microelectrode array, and facilitated a novel approach to estimating causal relationships between activity in neocortical subregions. Comparison with existing methods The holographic nature of the reconstruction method allowed significantly better estimation of the fine spatiotemporal detail of neuronal population activity, compared with interpolation alone, beyond the spatial resolution of the electrode arrays used. Pseudo-energy flow vector mapping was possible with high temporal precision, allowing a near-realtime estimate of causal interaction dynamics. Conclusions Basic near-field electromagnetic holography provides a powerful means to increase spatial resolution from electrode array data with careful choice of spatial filters and distance to reconstruction plane. More detailed approaches may provide the ability to volumetrically reconstruct activity patterns on neuronal tissue, but the ability to extract vectored data with the

  7. X-ray holography at Lawrence Livermore National Laboratory

    SciTech Connect

    Trebes, J.; Annese, C.; Birdsall, D.; Brase, J.; Gray, J.; Lane, S.; London, R.; Matthews, D.; Peters, D.; Pinkel, D.; Stone, G.; Rapp, D.; Rosen, M.; Weier, U.; Yorkey, T.

    1990-10-11

    The x-ray holography program at the Lawrence Livermore National Laboratory has two principal goals: (1) the development of x-ray diffraction techniques for DNA sequence analysis and (2) the development of x-ray laser holography for structural analysis of intact biological cells and organelles. DNA sequence analysis will be accomplished by applying x-ray diffraction techniques to determine the ensemble average of the sequence of labels along the individual elements of crystalline DNA. X-ray laser holographic imaging will be accomplished by applying three dimensional x-ray holography to elucidate the structure of few hundred angstrom objects such as 300 {Angstrom} chromatin fibers, nuclear pores and nucleic acid replication complexes in living cells. Existing laboratory x-ray lasers will be utilized to produce flash x-ray holograms of the biological structures.

  8. Pit Distribution Design for Computer-Generated Waveguide Holography

    NASA Astrophysics Data System (ADS)

    Yagi, Shogo; Imai, Tadayuki; Ueno, Masahiro; Ohtani, Yoshimitsu; Endo, Masahiro; Kurokawa, Yoshiaki; Yoshikawa, Hiroshi; Watanabe, Toshifumi; Fukuda, Makoto

    2008-02-01

    Multilayered waveguide holography (MWH) is one of a number of page-oriented data multiplexing holographies that will be applied to optical data storage and three-dimensional (3D) moving images. While conventional volumetric holography using photopolymer or photorefractive materials requires page-by-page light exposure for recording, MWH media can be made by employing stamping and laminating technologies that are suitable for mass production. This makes devising an economical mastering technique for replicating holograms a key issue. In this paper, we discuss an approach to pit distribution design that enables us to replace expensive electron beam mastering with economical laser beam mastering. We propose an algorithm that avoids the overlapping of even comparatively large adjacent pits when we employ laser beam mastering. We also compensate for the angular dependence of the diffraction power, which strongly depends on pit shape, by introducing an enhancement profile so that a diffracted image has uniform intensity.

  9. Compressive coherent anti-Stokes Raman scattering holography.

    PubMed

    Cocking, Alexander; Mehta, Nikhil; Shi, Kebin; Liu, Zhiwen

    2015-09-21

    Coherent anti-Stokes Raman scattering (CARS) holography captures both the amplitude and the phase of the anti-Stokes field generated from a sample and can thus perform single-shot, chemically selective three-dimensional imaging. We present compressive CARS holography, a numerical technique based on the concept of compressive sensing, to improve the quality of reconstructed images by leveraging sparsity in the source distribution and reducing the out-of-focus background noise. In particular, we use the two-step iterative shrinkage threshold (TwIST) algorithm with an l1 norm regularizer to iteratively retrieve images from an off axis CARS digital hologram. It is shown that the use of compressive CARS holography enhances the CARS holographic imaging technique by reducing noise and thereby effectively emulating a higher axial resolution using only a single shot hologram. PMID:26406699

  10. Measurement of thin films using very long acoustic wavelengths

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

  11. Digital holography with electron wave: measuring into the nanoworld

    NASA Astrophysics Data System (ADS)

    Mendoza Santoyo, Fernando; Voelkl, Edgar

    2016-04-01

    Dennis Gabor invented Holography in 1949. His main concern at the time was centered on the spherical aberration correction in the recently created electron microscopes, especially after O. Scherzer had shown mathematically that round electron optical lenses always have a positive spherical aberration coefficient and the mechanical requirements for minimizing the spherical aberration were too high to allow for atomic resolution. At the time the lack of coherent electron sources meant that in-line holography was developed using quasi-coherent light sources. As such Holography did not produce scientific good enough results to be considered a must use tool. In 1956, G. Moellenstedt invented a device called a wire-biprism that allowed the object and reference beams to be combined in an off-axis configuration. The invention of the laser at the end of the 1950s gave a great leap to Holography since this light source was highly coherent and hence led to the invention of Holographic Interferometry during the first lustrum of the 1960s. This new discipline in the Optics field has successfully evolved to become a trusted tool in a wide variety of areas. Coherent electron sources were made available only by the late 1970s, a fact that gave an outstanding impulse to electron holography so that today nanomaterials and structures belonging to a wide variety of subjects can be characterized in regards to their physical and mechanical parameters. This invited paper will present and discuss electron holography's state of the art applications to study the shape of nanoparticles and bacteria, and the qualitative and quantitative study of magnetic and electric fields produced by novel nano-structures.

  12. Shallow depth subsurface imaging with microwave holography

    NASA Astrophysics Data System (ADS)

    Zhuravlev, Andrei; Ivashov, Sergey; Razevig, Vladimir; Vasiliev, Igor; Bechtel, Timothy

    2014-05-01

    In this paper, microwave holography is considered as a tool to obtain high resolution images of shallowly buried objects. Signal acquisition is performed at multiple frequencies on a grid using a two-dimensional mechanical scanner moving a single transceiver over an area of interest in close proximity to the surface. The described FFT-based reconstruction technique is used to obtain a stack of plan view images each using only one selected frequency from the operating waveband of the radar. The extent of a synthetically-formed aperture and the signal wavelength define the plan view resolution, which at sounding frequencies near 7 GHz amounts to 2 cm. The system has a short depth of focus which allows easy selection of proper focusing plane. The small distance from the buried objects to the antenna does not prevent recording of clean images due to multiple reflections (as happens with impulse radars). The description of the system hardware and signal processing technique is illustrated using experiments conducted in dry sand. The microwave images of inert anti-personnel mines are demonstrated as examples. The images allow target discrimination based on the same visually-discernible small features that a human observer would employ. The demonstrated technology shows promise for modification to meet the specific practical needs required for humanitarian demining or in multi-sensor survey systems.

  13. Digital holography system for undergraduate student laboratory

    NASA Astrophysics Data System (ADS)

    Buranasiri, P.; Plaipichit, S.; Yindeesuk, W.; Yoshimori, K.

    2015-07-01

    In this paper, we discuss the digital holography (DH) experiment in our optical and communication laboratory course for undergraduate students at Physics department, KMITL. The purposes of DH experiment are presenting our students the meaning and advantage of DH and its applications. The Gabor configurations of in-line DH has been set up for recording a number of samples, which were placed on different distances, simultaneously. Then, the images of all objects have been numerical reconstructed by using computer. The students have been learned that all of reconstructed images have been got from only one time recording, while using the conventional recording technique, sharp images of different objects have been gotten from different recording time. The students also have been learned how to use DH technique for investigation some different kinds of samples on their own of interested such as a human hair or a fingerprint. In our future work, our DH system will be developed to be a portable apparatus for easily showing to children in different areas.

  14. Application of neutron holography to polycrystalline samples

    NASA Astrophysics Data System (ADS)

    Szakál, A.; Markó, M.; Krexner, G.; Cser, L.

    2015-07-01

    Neutron holography can be an efficient tool to investigate the local real-space structure of crystalline materials around specific probe nuclei serving as radiation source or detector. The positions of atoms in the neighborhood of such nuclei are observable with high (picometry) accuracy. Measurements of this type require orientational order and, therefore, restrict the range of study essentially to single crystals. However, if the information searched for is limited to the distances between the probe and the surrounding nuclei instead of their positions, holographic techniques can be applied to polycrystalline samples as well. In order to prove this statement, the expected multi-wavelength holographic signal of a polycrystalline sample was calculated. The holographic signal can be obtained by applying time-of-flight techniques, and by using a proper mathematical procedure, the distances between the probe nucleus and the surrounding nuclei can be reconstructed. A model calculation taking into account real instrument parameters confirms this expectation. The experimental verification of the predictions can be undertaken at existing pulsed neutron sources being able to provide the required experimental conditions. This new method opens the way to expand the field of investigation towards gaining information about the local atomic structure of polycrystalline materials which are of importance also in various applications.

  15. m-Learning and holography: Compatible techniques?

    NASA Astrophysics Data System (ADS)

    Calvo, Maria L.

    2014-07-01

    Since the last decades, cell phones have become increasingly popular and are nowadays ubiquitous. New generations of cell phones are now equipped with text messaging, internet, and camera features. They are now making their way into the classroom. This is creating a new teaching and learning technique, the so called m-Learning (or mobile-Learning). Because of the many benefits that cell phones offer, teachers could easily use them as a teaching and learning tool. However, an additional work from the teachers for introducing their students into the m-Learning in the classroom needs to be defined and developed. As an example, optical techniques, based upon interference and diffraction phenomena, such as holography, appear to be convenient topics for m-Learning. They can be approached with simple examples and experiments within the cell phones performances and classroom accessibility. We will present some results carried out at the Faculty of Physical Sciences in UCM to obtain very simple holographic recordings via cell phones. The activities were carried out inside the course on Optical Coherence and Laser, offered to students in the fourth course of the Grade in Physical Sciences. Some open conclusions and proposals will be presented.

  16. A simplified holography based superresolution system

    NASA Astrophysics Data System (ADS)

    Mudassar, Asloob Ahmad

    2015-12-01

    In this paper we are proposing a simple idea based on holography to achieve superresolution. The object is illuminated by three fibers which maintain the mutual coherence between the light waves. The object in-plane rotation along with fiber-based illumination is used to achieve superresolution. The object in a 4f optical system is illuminated by an on-axis fiber to make the central part of the object's spectrum to the pass through the limiting square-aperture placed at the Fourier plane and the corresponding hologram of the image is recorded at the image plane. The on-axis fiber is switched off and the two off axis fibers (one positioned on the vertical axis and the other positioned on diagonal) are switched on one by one for each orientation of the object position. Four orientations of object in-plane rotation are used differing in angle by 90°. This will allow the recording of eight holographic images in addition to the one recorded with on-axis fiber. The three fibers are at the vertices of a right angled isosceles triangle and are aligned toward the centre of the lens following the fiber plane to generate plane waves for object illumination. The nine holographic images are processed for construction of object's original spectrum, the inverse of which gives the super-resolved image of the original object. Mathematical modeling and simulations are reported.

  17. Holography of incoherently illuminated 3D scenes

    NASA Astrophysics Data System (ADS)

    Shaked, Natan T.; Rosen, Joseph

    2008-04-01

    We review several methods of generating holograms of 3D realistic objects illuminated by incoherent white light. Using these methods, it is possible to obtain holograms with a simple digital camera, operating in regular light conditions. Thus, most disadvantages characterizing conventional holography, namely the need for a powerful, highly coherent laser and meticulous stability of the optical system are avoided. These holograms can be reconstructed optically by illuminating them with a coherent plane wave, or alternatively by using a digital reconstruction technique. In order to generate the proposed hologram, the 3D scene is captured from multiple points of view by a simple digital camera. Then, the acquired projections are digitally processed to yield the final hologram of the 3D scene. Based on this principle, we can generate Fourier, Fresnel, image or other types of holograms. To obtain certain advantages over the regular holograms, we also propose new digital holograms, such as modified Fresnel holograms and protected correlation holograms. Instead of shifting the camera mechanically to acquire a different projection of the 3D scene each time, it is possible to use a microlens array for acquiring the entire projections in a single camera shot. Alternatively, only the extreme projections can be acquired experimentally, while the middle projections are predicted digitally by using the view synthesis algorithm. The prospective goal of these methods is to facilitate the design of a simple, portable digital holographic camera which can be useful for a variety of practical applications.

  18. Synthetic holography based on scanning microcavity

    NASA Astrophysics Data System (ADS)

    Di Donato, A.; Farina, M.

    2015-11-01

    Synthetic optical holography (SOH) is an imaging technique, introduced in scanning microscopy to record amplitude and phase of a scattered field from a sample. In this paper, it is described a novel implementation of SOH through a lens-free low-coherence system, based on a scanning optical microcavity. This technique combines the low-coherence properties of the source with the mutual interference of scattered waves and the resonant behavior of a micro-cavity, in order to realize a high sensitive imaging system. Micro-cavity is compact and realized by approaching a cleaved optical fiber to the sample. The scanning system works in an open-loop configuration without the need for a reference wave, usually required in interferometric systems. Measurements were performed over calibration samples and a lateral resolution of about 1 μm is achieved by means of an optical fiber with a Numerical Aperture (NA) equal to 0.1 and a Mode Field Diameter (MDF) of 5.6 μm.

  19. Holography And Holometry Applications In Dental Research

    NASA Astrophysics Data System (ADS)

    Willenborg, George C.

    1987-06-01

    The earliest reference to holographic applications appeared in the dental literature in 1972 when Wictorin, Bjelkhagen and Abramson described a method to study elastic deformation of defective gold solder joints in simulated fixed bridges. Their paper, published in the Swedish dental literature, offered a concise presentation of the interferometry technique which led to the development of other research applications of holographic interferometry(holometry) in dentistry. In this presentation, the development and application of the interferometry technique in the dental field will be discussed. Various interesting and potentially useful applications of holography have appeared in the dental literature over the past decade. Some of these, which will be discussed, include the use of holograms as a storage medium for dental study models, multiplexing of computer(CT) scan sections to form white light viewable holograms and the potential application of holographic training aids in the teaching of the basic courses of dental anatomy and restorative dentistry. In addition, some unique related applications will be mentioned including a laser reflection method for accurate non-contact measurement of tooth mobility/movement and a technique for contour mapping of occlusal surfaces to measure wear of restorative materials.

  20. Applications Of Endoscopic Holography Through Fiber Optics

    NASA Astrophysics Data System (ADS)

    Bjelkhagen, Hans I.; Friedman, M. D.; Epstein, Max

    1989-10-01

    Holographic endoscopy or endoholography combines the features of endoscopy and holography. It can be utilized in holographic imaging or interferometry inside natural cavities of the body. In imaging, the ability to record a three-dimensional, large focal depth, high resolution image of internal organs and tissue may greatly enhance the detection of disease and abnormality. With contact recording endoholography it is possible to obtain high resolution holographic recordings which can be examined microscopically. In this technique, a specially designed endoscope uses a single-mode optical fiber for illumination where Denisyuk holograms are recorded on film at the endoscope's distal end. The holograms are viewed under a stereomicroscope with high magnification, allowing for the observation of individual cells. Specific dyes are used to enhance the contrast of the tissue prior to the recording of the holographic images. In endoholographic interferometry, the use of conventional multi-fiber imaging structures is sufficient to obtain an adequate recording of interference patterns. The use of conventional fiberoptic imaging structures for holographic investigations of displacement and vibration is demonstrated. Image-plane holograms are formed at the proximal output end of an imaging multifiber. Pairs of double-pulsed holograms of dynamic events are recorded, one through the multifiber, the other in a conventional manner as a standard of reference. The fringes of both holograms are practically identical. The ability to perform measurements in holographic interferometry through optical fibers should lead to further developments in medical as well as industrial applications.

  1. Probing Molecular Dynamics by Laser-Induced Backscattering Holography.

    PubMed

    Haertelt, Marko; Bian, Xue-Bin; Spanner, Michael; Staudte, André; Corkum, Paul B

    2016-04-01

    We use differential holography to overcome the forward scattering problem in strong-field photoelectron holography. Our differential holograms of H_{2} and D_{2} molecules exhibit a fishbonelike structure, which arises from the backscattered part of the recolliding photoelectron wave packet. We demonstrate that the backscattering hologram can resolve the different nuclear dynamics between H_{2} and D_{2} with subangstrom spatial and subcycle temporal resolution. In addition, we show that attosecond electron dynamics can be resolved. These results open a new avenue for ultrafast studies of molecular dynamics in small molecules. PMID:27081975

  2. Probing Molecular Dynamics by Laser-Induced Backscattering Holography

    NASA Astrophysics Data System (ADS)

    Haertelt, Marko; Bian, Xue-Bin; Spanner, Michael; Staudte, André; Corkum, Paul B.

    2016-04-01

    We use differential holography to overcome the forward scattering problem in strong-field photoelectron holography. Our differential holograms of H2 and D2 molecules exhibit a fishbonelike structure, which arises from the backscattered part of the recolliding photoelectron wave packet. We demonstrate that the backscattering hologram can resolve the different nuclear dynamics between H2 and D2 with subangstrom spatial and subcycle temporal resolution. In addition, we show that attosecond electron dynamics can be resolved. These results open a new avenue for ultrafast studies of molecular dynamics in small molecules.

  3. High temperature measurements of martensitic transformations using digital holography.

    PubMed

    Thiesing, Benjamin P; Mann, Christopher J; Dryepondt, Sebastien

    2013-07-01

    During thermal cycling of nickel-aluminum-platinum (NiAlPt) and single crystal iron-chromium-nickel (FeCrNi) alloys, the structural changes associated with the martensite to austenite phase transformation were measured using dual-wavelength digital holography. Real-time in situ measurements reveal the formation of striations within the NiAlPt alloy at 70°C and the FeCrNi alloy at 520°C. The results demonstrate that digital holography is an effective technique for acquiring noncontact, high precision information of the surface evolution of alloys at high temperatures. PMID:23842235

  4. Holography and the virtual patient: the holographic medical image

    NASA Astrophysics Data System (ADS)

    Ko, Kathryn; Erickson, Ronald R.; Webster, John M.

    1996-12-01

    Practical holographic systems utilizing the pulsed laser are finding potential applications in medicine. Exploiting both the hologram's true 3D image and holographic interferometry these techniques enhance the physician's vision beyond the 2D radiological imaging of even the best CT and MRI. The authors describe the use of pulsed laser holography as applied to the morphological specialties: anatomy, pathology, and surgery. The authors report on the Holographic Brain Anatomy Atlas for medical education; pathologic documentation with holography, and the use of holographic interferometry in surgical planning. The techniques are outlined and a discussion on the interpretation of holographic interferometry with living subjects is provided.

  5. High Temperature Measurements Of Martensitic transformations Using Digital Holography

    SciTech Connect

    Thiesing, Benjamin; Mann, Christopher J; Dryepondt, Sebastien N

    2013-01-01

    During thermal cycling of nickel-aluminum-platinum (NiAlPt) and single crystal Fe-15Cr-15Ni alloys, the structural changes associated with the martensite to austenite phase transformation were measured using dual-wavelength digital holography. Real-time in-situ measurements reveal the formation of striations within the NiPtAl alloy at 70 C and the FeCrNi alloy at 520 C. The results demonstrate that digital holography is an effective technique for acquiring non-contact, high precision information of the surface evolution of alloys at high temperatures.

  6. Room Acoustics

    NASA Astrophysics Data System (ADS)

    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.

  7. Acoustic Neuroma

    MedlinePlus

    ... slow growing tumor which arise primarily from the vestibular portion of the VIII cranial nerve and lie ... you have a "brain tumor" called acoustic neuroma (vestibular schwannoma). You think you are the only one ...

  8. Underwater Acoustics

    NASA Astrophysics Data System (ADS)

    Kuperman, William A.; Roux, Philippe

    It is well underwater established that sound waves, compared to electromagnetic waves, propagate long distances in the ocean. Hence, in the ocean as opposed to air or a vacuum, one uses sound navigation and ranging (SONAR) instead navigation and ranging (SONAR) of radar, acoustic communication instead of radio, and acoustic imaging and tomography instead of microwave or optical imaging or X-ray tomography. Underwater acoustics is the science of sound in water (most commonly in the ocean) and encompasses not only the study of sound propagation, but also the masking of sound signals by interfering phenomenon and signal processing for extracting these signals from interference. This chapter we will present the basics physics of ocean acoustics and then discuss applications.

  9. Spaceflight Holography Investigation in a Virtual Apparatus

    NASA Technical Reports Server (NTRS)

    2003-01-01

    The movement of a particle in a fluid is one of the most fundamental processes in physics and plays an important role in materials science. For example, the physics of crystal growth from a nucleation site in solution can be dominated by movement of the solution over the crystal surface. Gravity usually dominates the equations of motion, but in microgravity other terms can dominate, making the equation much more complex. Until recently, the equations were solved only by numerical methods and/or by neglecting terms. During this study, we discovered an exact solution to the equations, which shows that the usually neglected terms become extremely important in microgravity. We also developed diagnostic recording methods using holography to save all of the particle field data, allowing the experiment to essentially be transferred from space back to earth in what we call the virtual apparatus . We will record holograms of particle distributions in motion in microgravity and bring them back to earth for analysis, allowing the study of the full three-dimensional motion of sets of particles, allowing us to test the new analytical solutions. The experiment will also provide accurate measurements of the quasi-steady acceleration of the space platform and other interesting microgravity and g-jitter effects. This program will produce the flight definition for an experiment in the microgravity environment of space to validate the theoretical model. We will design an experiment with the help of the theoretical model that is optimized for testing the model, measuring g, g-jitter, and other microgravity phenomena.

  10. X-ray holography with an atomic scatterer.

    PubMed

    Mityureva, A A; Smirnov, V V

    2016-08-01

    X-ray holography scheme with reference scatterer consisting of heavy atom as reference center and its link to an object consisting of several light atoms and using controlled variation of the alignment is represented. The scheme can reproduce an object in three dimensions with atomic resolution. The distorting factors of reconstruction are considered. PMID:27137096

  11. Intellectual property issues in holography and high tech

    NASA Astrophysics Data System (ADS)

    Reingand, Nadya

    2004-06-01

    The author with technical education background (Ph.D. in holography) shares her 3+ years of experience working on intellectual property (IP) issues that includes patents, trademarks, and copyrights. A special attention is paid to the patent issues: the application procedure, the patent requirements, the databases for prior art search, how to make the cost efficient filing.

  12. Calendar effects in quantum mechanics in view of interactive holography

    NASA Astrophysics Data System (ADS)

    Berkovich, Simon

    2013-04-01

    Quantum mechanics in terms of interactive holography appears as `normal' science [1]. With the holography quantum behavior is determined by the interplay of material formations and their conjugate images. To begin with, this effortlessly elucidates the nonlocality in quantum entanglements. Then, it has been shown that Schr"odinger's dynamics for a single particle arises from Bi-Fragmental random walks of the particle itself and its holographic image. For many particles this picture blurs with fragments merging as bosons or fermions. In biomolecules, swapping of particles and their holographic placeholders leads to self-replication of the living matter. Because of broad interpretations of quantum formalism direct experiments attributing it to holography may not be very compelling. The holographic mechanism better reveals as an absolute frame of reference. A number of physical and biological events exhibit annual variations when Earth orbital position changes with respect to the universal holographic mechanism. The well established calendar variations of heart attacks can be regarded as a positive outcome of a generalization of the Michelson experiment, where holography is interferometry and ailing hearts are detectors of pathologically replicated proteins. Also, there have been already observed calendar changes in radioactive decay rates. The same could be expected for various fine quantum experiences, like, e.g., Josephson tunneling. In other words, Quantum Mechanics (February) Quantum Mechanics (August). [1] S. Berkovich, ``A comprehensive explanation of quantum mechanics,'' www.cs.gwu.edu/research/technical-report/170 .

  13. Intraoperative brain tumor resection cavity characterization with conoscopic holography

    NASA Astrophysics Data System (ADS)

    Simpson, Amber L.; Burgner, Jessica; Chen, Ishita; Pheiffer, Thomas S.; Sun, Kay; Thompson, Reid C.; Webster, Robert J., III; Miga, Michael I.

    2012-02-01

    Brain shift compromises the accuracy of neurosurgical image-guided interventions if not corrected by either intraoperative imaging or computational modeling. The latter requires intraoperative sparse measurements for constraining and driving model-based compensation strategies. Conoscopic holography, an interferometric technique that measures the distance of a laser light illuminated surface point from a fixed laser source, was recently proposed for non-contact surface data acquisition in image-guided surgery and is used here for validation of our modeling strategies. In this contribution, we use this inexpensive, hand-held conoscopic holography device for intraoperative validation of our computational modeling approach to correcting for brain shift. Laser range scan, instrument swabbing, and conoscopic holography data sets were collected from two patients undergoing brain tumor resection therapy at Vanderbilt University Medical Center. The results of our study indicate that conoscopic holography is a promising method for surface acquisition since it requires no contact with delicate tissues and can characterize the extents of structures within confined spaces. We demonstrate that for two clinical cases, the acquired conoprobe points align with our model-updated images better than the uncorrected images lending further evidence that computational modeling approaches improve the accuracy of image-guided surgical interventions in the presence of soft tissue deformations.

  14. Terahertz digital holography image processing based on MAP algorithm

    NASA Astrophysics Data System (ADS)

    Chen, Guang-Hao; Li, Qi

    2015-04-01

    Terahertz digital holography combines the terahertz technology and digital holography technology at present, fully exploits the advantages in both of them. Unfortunately, the quality of terahertz digital holography reconstruction images is gravely harmed by speckle noise which hinders the popularization of this technology. In this paper, the maximum a posterior estimation (MAP) filter is harnessed for the restoration of the digital reconstruction images. The filtering results are compared with images filtered by Wiener Filter and conventional frequency-domain filters from both subjective and objective perspectives. As for objective assessment, we adopted speckle index (SPKI) and edge preserving index (EPI) to quantitate the quality of images. In this paper, Canny edge detector is also used to outline the target in original and reconstruction images, which then act as an important role in the evaluation of filter performance. All the analysis indicate that maximum a posterior estimation filtering algorithm performs superiorly compared with the other two competitors in this paper and has enhanced the terahertz digital holography reconstruction images to a certain degree, allowing for a more accurate boundary identification.

  15. Conoscopic holography for image registration: a feasibility study

    NASA Astrophysics Data System (ADS)

    Lathrop, Ray A.; Cheng, Tiffany T.; Webster, Robert J., III

    2009-02-01

    Preoperative image data can facilitate intrasurgical guidance by revealing interior features of opaque tissues, provided image data can be accurately registered to the physical patient. Registration is challenging in organs that are deformable and lack features suitable for use as alignment fiducials (e.g. liver, kidneys, etc.). However, provided intraoperative sensing of surface contours can be accomplished, a variety of rigid and deformable 3D surface registration techniques become applicable. In this paper, we evaluate the feasibility of conoscopic holography as a new method to sense organ surface shape. We also describe potential advantages of conoscopic holography, including the promise of replacing open surgery with a laparoscopic approach. Our feasibility study investigated use of a tracked off-the-shelf conoscopic holography unit to perform a surface scans on several types of biological and synthetic phantom tissues. After first exploring baseline accuracy and repeatability of distance measurements, we performed a number of surface scan experiments on the phantom and ex vivo tissues with a variety of surface properties and shapes. These indicate that conoscopic holography is capable of generating surface point clouds of at least comparable (and perhaps eventually improved) accuracy in comparison to published experimental laser triangulation-based surface scanning results.

  16. Dopant profiling in the TEM, progress towards quantitative electron holography

    SciTech Connect

    Cooper, David; Truche, Robert; Chabli, Amal; Twitchett-Harrison, Alison C.; Midgley, Paul A.; Dunin-Borkowski, Rafal E.

    2007-09-26

    Off-axis electron holography has been used to characterise the dopant potential in GaAs p-n junctions. We show that the measured potential across the junctions is affected by both FIB specimen preparation and by charging in the TEM and suggest methods that can be used to minimise these problems.

  17. Pharmacological evidence that NaHS inhibits the vasopressor responses induced by stimulation of the preganglionic sympathetic outflow in pithed rats.

    PubMed

    Centurión, David; De la Cruz, Saúl Huerta; Gutiérrez-Lara, Erika J; Beltrán-Ornelas, Jesús H; Sánchez-López, Araceli

    2016-01-01

    It has been reported that i.v. administration of NaHS, a donor of H2S, elicited dose-dependent hypotension although the mechanisms are not completely understood. In this regard, several mechanisms could be involved including the inhibition of the vasopressor sympathetic outflow. Thus, this study was designed to determine the potential capability of NaHS to mediate inhibition of the vasopressor responses induced by preganglionic sympathetic stimulation. For this purpose, Wistar rats were anaesthetised, pithed and cannulated for drug administration. In animals pre-treated with gallamine, the effect of i.v. infusion of NaHS (310 and 560μg/kgmin) or its vehicle (phosphate buffer) was determined on the vasopressor responses induced by: (1) sympathetic stimulation (0.03-10Hz); (2) i.v. bolus injections of exogenous noradrenaline (0.03-3μg/kg); or (3) methoxamine (1-100μg/kg). The vasopressor responses induced by preganglionic sympathetic stimulation were dose-dependently inhibited by i.v. infusion of NaHS (310 and 560μg/kgmin), but not by vehicle, particularly at high frequencies. In marked contrast, the vasopressor responses to exogenous noradrenaline or methoxamine were not inhibited by the above doses of NaHS or its vehicle. The above results, taken together, demonstrate that NaHS inhibited the vasopressor responses induced by preganglionic sympathetic outflow by a prejunctional mechanism. This is the first evidence demonstrating this effect by NaHS that may contribute, at least in part, to the hypotension induced by NaHS. PMID:26643171

  18. Erythrocyte Li+/Na+ and Na+/H+ exchange, cardiac anatomy and function in insulin-dependent diabetics.

    PubMed

    Semplicini, A; Lusiani, L; Marzola, M; Ceolotto, G; Mozzato, M G; Zanette, G; Donadon, V; Stefanini, M G; Zanuttini, D; Pessina, A C

    1992-04-01

    It has been proposed that an increased activity of cell membrane Na+/H+ exchange, mirrored by increased erythrocyte Li+/Na+ exchange, may facilitate cell hypertrophy and hyperplasia. Patients with insulin-dependent diabetes mellitus may develop a specific cardiomyopathy with systolic and diastolic abnormalities and increased thickness of the left ventricle. Therefore, we have investigated the relationships between erythrocyte Li+/Na+ and Na+/H+ exchange and echocardiographic parameters in 31 male insulin-dependent diabetics (aged 17-68), in good metabolic control. Three had untreated mild hypertension. In all patients the urinary albumin excretion rate was less than 200 micrograms min-1. Ten patients had a Li+/Na+ countertransport higher than 0.37 mmol l-1 cell h-1, the upper normal limit for our laboratory (0.49 +/- 0.10, mean +/- SD). In comparison with the patients with normal countertransport, they had increased interventricular septum thickness and relative wall thickness (h/r). End diastolic volume and cardiac index were reduced while blood pressure and urinary albumin excretion rate were similar. In the whole study group, interventricular septum thickness was significantly correlated to Li+/Na+ exchange (r = 0.61, P less than 0.001) and Na+/H+ exchange (r = 0.35, P less than 0.05), independently of the effect of age and blood pressure. Posterior wall thickness was correlated to Li+/Na+ exchange (r = 0.38, P less than 0.05) and h/r to Li+/Na+ exchange (r = 0.41, P less than 0.05) and to Na+/H+ exchange (r = 0.44, P less than 0.05). Li+/Na+ exchange was negatively correlated to cardiac index (r = -0.37, P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1323468

  19. Regulation of vacuolar Na+/H+ exchange in Arabidopsis thaliana by the salt-overly-sensitive (SOS) pathway.

    PubMed

    Qiu, Quan-Sheng; Guo, Yan; Quintero, Francisco J; Pardo, José M; Schumaker, Karen S; Zhu, Jian-Kang

    2004-01-01

    For plants growing in highly saline environments, accumulation of sodium in the cell cytoplasm leads to disruption of metabolic processes and reduced growth. Maintaining low levels of cytoplasmic sodium requires the coordinate regulation of transport proteins on numerous cellular membranes. Our previous studies have linked components of the Salt-Overly-Sensitive pathway (SOS1-3) to salt tolerance in Arabidopsis thaliana and demonstrated that the activity of the plasma membrane Na+/H+ exchanger (SOS1) is regulated by SOS2 (a protein kinase) and SOS3 (a calcium-binding protein). Current studies were undertaken to determine if the Na+/H+ exchanger in the vacuolar membrane (tonoplast) of Arabidopsis is also a target for the SOS regulatory pathway. Characterization of tonoplast Na+/H+ exchange demonstrated that it represents activity originating from the AtNHX proteins since it could be inhibited by 5-(N-methyl-N-isobutyl)amiloride and by anti-NHX1 antibodies. Transport activity was selective for sodium (apparent Km=31 mm) and electroneutral (one sodium ion for each proton). When compared with tonoplast Na+/H+-exchange activity in wild type, activity was significantly higher, greatly reduced, and unchanged in sos1, sos2, and sos3, respectively. Activated SOS2 protein added in vitro increased tonoplast Na+/H+-exchange activity in vesicles isolated from sos2 but did not have any effect on activity in vesicles isolated from wild type, sos1, or sos3. These results demonstrate that (i) the tonoplast Na+/H+ exchanger in Arabidopsis is a target of the SOS regulatory pathway, (ii) there are branches to the SOS pathway, and (iii) there may be coordinate regulation of the exchangers in the tonoplast and plasma membrane. PMID:14570921

  20. Reconstructing transient acoustic radiation from an arbitrary object with a uniform surface velocity distribution.

    PubMed

    Wu, Sean F

    2014-08-01

    This paper presents the general formulations for reconstructing the transient acoustic field generated by an arbitrary object with a uniformly distributed surface velocity in free space. These formulations are derived from the Kirchhoff-Helmholtz integral theory that correlates the transient acoustic pressure at any field point to those on the source surface. For a class of acoustic radiation problems involving an arbitrarily oscillating object with a uniformly distributed surface velocity, for example, a loudspeaker membrane, the normal surface velocity is frequency dependent but is spatially invariant. Accordingly, the surface acoustic pressure is expressible as the product of the surface velocity and the quantity that can be solved explicitly by using the Kirchhoff-Helmholtz integral equation. This surface acoustic pressure can be correlated to the field acoustic pressure using the Kirchhoff-Helmholtz integral formulation. Consequently, it is possible to use nearfield acoustic holography to reconstruct acoustic quantities in entire three-dimensional space based on a single set of acoustic pressure measurements taken in the near field of the target object. Examples of applying these formulations to reconstructing the transient acoustic pressure fields produced by various arbitrary objects are demonstrated. PMID:25096086

  1. Synthetic aperture in terahertz in-line digital holography for resolution enhancement.

    PubMed

    Huang, Haochong; Rong, Lu; Wang, Dayong; Li, Weihua; Deng, Qinghua; Li, Bin; Wang, Yunxin; Zhan, Zhiqiang; Wang, Xuemin; Wu, Weidong

    2016-01-20

    Terahertz digital holography is a combination of terahertz technology and digital holography. In digital holography, the imaging resolution is the key parameter in determining the detailed quality of a reconstructed wavefront. In this paper, the synthetic aperture method is used in terahertz digital holography and the in-line arrangement is built to perform the detection. The resolved capability of previous terahertz digital holographic systems restricts this technique to meet the requirement of practical detection. In contrast, the experimental resolved power of the present method can reach 125 μm, which is the best resolution of terahertz digital holography to date. Furthermore, the basic detection of a biological specimen is conducted to show the practical application. In all, the results of the proposed method demonstrate the enhancement of experimental imaging resolution and that the amplitude and phase distributions of the fine structure of samples can be reconstructed by using terahertz digital holography. PMID:26835956

  2. Human Na(+)/H(+) exchanger isoform 6 is found in recycling endosomes of cells, not in mitochondria.

    PubMed

    Brett, Christopher L; Wei, Ying; Donowitz, Mark; Rao, Rajini

    2002-05-01

    Since the discovery of the first intracellular Na(+)/H(+) exchanger in yeast, Nhx1, multiple homologs have been cloned and characterized in plants. Together, studies in these organisms demonstrate that Nhx1 is located in the prevacuolar/vacuolar compartment of cells where it sequesters Na(+) into the vacuole, regulates intravesicular pH, and contributes to vacuolar biogenesis. In contrast, the human homolog of Nhx1, Na(+)/H(+) exchanger isoform 6 (NHE6), has been reported to localize to mitochondria when transiently expressed as a fusion with green fluorescent protein. This result warrants reevaluation because it conflicts with predictions from phylogenetic analyses. Here we demonstrate that when epitope-tagged NHE6 is transiently expressed in cultured mammalian cells, it does not colocalize with mitochondrial markers. It also does not colocalize with markers of the lysosome, late endosome, trans-Golgi network, or Golgi cisternae. Rather, NHE6 is distributed in recycling compartments and transiently appears on the plasma membrane. These results suggest that, like its homologs in yeast and plants, NHE6 is an endosomal Na(+)/H(+) exchanger that may regulate intravesicular pH and volume and contribute to lysosomal biogenesis. PMID:11940519

  3. The amiloride-sensitive Na+/H+ exchange antiporter and control of intracellular pH in hippocampal brain slices.

    PubMed

    Lin, C W; Kalaria, R N; Kroon, S N; Bae, J Y; Sayre, L M; LaManna, J C

    1996-08-26

    The intracellular pH, 7.54 +/- 0.03 (mean +/- S.D., n = 15), determined with the Neutral red method, of the hippocampal brain slice preparation under baseline incubation conditions is considerably more alkaline than the bath buffer pH. Neutralization by amiloride suggests that the alkalinity was due to Na+/H+ exchange antiporter activation. To characterize the brain Na+/H+ exchange antiporter we compared the inhibitory effects of MIA, amiloride and other 5-N substituted analogues on proton extrusion after acid loading by transient exposure to ammonium chloride in the isolated hippocampal brain slice preparation. The potencies of amiloride compounds on the initial recovery rate of intracellular pH after acid-loading were DMA > MIA > HMA = MHA > or = IPA-HCI > IPA > MNPA = Amil > Benzamil. The greater potency of the 5-N substituted analogs of amiloride over amiloride and benzamil strongly suggest that Na+/H+ exchange antiporter is the mechanism responsible for alkalinization in the isolated hippocampal brain slice in vitro. PMID:8883860

  4. Acoustic biosensors

    PubMed Central

    Fogel, Ronen; Seshia, Ashwin A.

    2016-01-01

    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. PMID:27365040

  5. Acoustic biosensors.

    PubMed

    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. PMID:27365040

  6. History of structural acoustics and vibrations in the Acoustical Society of America

    NASA Astrophysics Data System (ADS)

    Feit, David; Strasberg, Murray; Ungar, Eric E.

    2002-05-01

    Structural acoustics refers to the interaction of sound and structures-the response of structures to sound, the radiation of sound from vibrating structures, and the effect of the acoustic medium on the structural vibrations. Interest in these subjects increased greatly during the 1930s and 40s because of practical applications in the design of microphones and loud speakers used in telephones, radios, and electronic phonographs. The combination of electrical and mechanical systems lead to the use of electrical engineering concepts such as impedance, circuits, and electrical analogies, in the analysis of mechanical systems. In later years, much of the work dealt with various aspects of underwater structures, prompted by U.S. Navy interests. The field, which began with classical analytical mechanics applications, has progressed to new approaches, including statistical energy analysis, near-field acoustical holography, fuzzy structures, active control of vibrations, and smart materials. In recognition of these new developments, the name of the technical committee was changed in 1987 from ``Shock and Vibration'' to ``Structural Acoustics and Vibration.''

  7. Scanning tomographic acoustic microscopy: principles and recent developments (Invited Paper)

    NASA Astrophysics Data System (ADS)

    Wade, G.; Meyyappan, A.

    1987-09-01

    Acoustic Microscopy is an important branch of non-destructive evaluation which provides high resolution for imaging the detailed structure of a small object. When an acoustic microscope operates in the transmission mode, the micrograph is simply a shadowgraph of all the structures encountered by the acoustic wave passing through the object. Because of diffraction and overlapping, the resultant images are difficult to comprehend in the case of specimens of substantial thickness and structural complexity. We used the principles of diffraction tomography and acoustical holography along with digital calcuations of wavefield propagation to overcome this problem. We have described in previously-published work how a scanning laser acoustic microscope (SLAM) can be modified to obtain data for subsurface tomographic imaging. In this paper, we review the principles of scanning tomographic acoustic microscopy (STAM). The required modification of SLAM to obtain STAM and the reconstruction process are described. We show how we are able to accurately acquire the complex-amplitude information necessary for image reconstruction. We demonstrate the power of this technique by comparing digitally-computed images thus obtained with analogue images of a conventional SLAM. The results show that high-quality, high-resolution subsurface images can be obtained from experimentally acquired data. We also describe techniques to obtain projection data from different angles of wave incidence enabling us to tomographically reconstruct different planes of a complex specimen in microscopic detail. With these modifications in place, STAM should shortly become a powerful tool in non-destructive evaluation.

  8. Nucleoporin 35 regulates cardiomyocyte pH homeostasis by controlling Na+-H+ exchanger-1 expression.

    PubMed

    Xu, Liang; Pan, Lei; Li, Jun; Huang, Bijun; Feng, Jing; Li, Changming; Wang, Shiyi; The, Erlinda; Liu, Yuan; Yuan, Tianyou; Zhen, Lixiao; Liang, Dandan; Liu, Yi; Li, Li; Cui, Yingyu; Jiang, Xiaoyan; Peng, Luying; Chen, Yi-Han

    2015-10-01

    The mammalian nuclear pore complex is comprised of ∼ 30 different nucleoporins (Nups). It governs the nuclear import of gene expression modulators and the export of mRNAs. In cardiomyocytes, Na(+)-H(+) exchanger-1 (NHE1) is an integral membrane protein that exclusively regulates intracellular pH (pHi) by exchanging one intracellular H(+) for one extracellular Na(+). However, the role of Nups in cardiac NHE1 expression remains unknown. We herein report that Nup35 regulates cardiomyocyte NHE1 expression by controlling the nucleo-cytoplasmic trafficking of nhe1 mRNA. The N-terminal domain of Nup35 determines nhe1 mRNA nuclear export by targeting the 5'-UTR (-412 to -213 nt) of nhe1 mRNA. Nup35 ablation weakens the resistance of cardiomyocytes to an acid challenge by depressing NHE1 expression. Moreover, we identify that Nup35 and NHE1 are simultaneously downregulated in ischemic cardiomyocytes both in vivo and in vitro. Enforced expression of Nup35 effectively counteracts the anoxia-induced intracellular acidification. We conclude that Nup35 selectively regulates cardiomyocyte pHi homeostasis by posttranscriptionally controlling NHE1 expression. This finding reveals a novel regulatory mechanism of cardiomyocyte pHi, and may provide insight into the therapeutic strategy for ischemic cardiac diseases. PMID:26260029

  9. Purification and Functional Reconstitution of a Seven-Subunit Mrp-Type Na+/H+ Antiporter

    PubMed Central

    Morino, Masato; Suzuki, Toshiharu; Ito, Masahiro

    2014-01-01

    Mrp antiporters and their homologues in the cation/proton antiporter 3 family of the Membrane Transporter Database are widely distributed in bacteria. They have major roles in supporting cation and cytoplasmic pH homeostasis in many environmental, extremophilic, and pathogenic bacteria. These antiporters require six or seven hydrophobic proteins that form hetero-oligomeric complexes, while most other cation/proton antiporters require only one membrane protein for their activity. The resemblance of three Mrp subunits to membrane-embedded subunits of the NADH:quinone oxidoreductase of respiratory chains and to subunits of several hydrogenases has raised interest in the evolutionary path and commonalities of their proton-translocating domains. In order to move toward a greater mechanistic understanding of these unusual antiporters and to rigorously demonstrate that they function as secondary antiporters, powered by an imposed proton motive force, we established a method for purification and functional reconstitution of the seven-subunit Mrp antiporter from alkaliphilic Bacillus pseudofirmus OF4. Na+/H+ antiporter activity was demonstrated by a fluorescence-based assay with proteoliposomes in which the Mrp complex was coreconstituted with a bacterial FoF1-ATPase. Proton pumping by the ATPase upon addition of ATP generated a proton motive force across the membranes that powered antiporter activity upon subsequent addition of Na+. PMID:24142251

  10. Restoration of Na+/H+ exchanger NHE3-containing macrocomplexes ameliorates diabetes-associated fluid loss

    PubMed Central

    He, Peijian; Zhao, Luqing; Zhu, Lixin; Weinman, Edward J.; De Giorgio, Roberto; Koval, Michael; Srinivasan, Shanthi; Yun, C. Chris

    2015-01-01

    Diarrhea is one of the troublesome complications of diabetes, and the underlying causes of this problem are complex. Here, we investigated whether altered electrolyte transport contributes to diabetic diarrhea. We found that the expression of Na+/H+ exchanger NHE3 and several scaffold proteins, including NHE3 regulatory factors (NHERFs), inositol trisphosphate (IP3) receptor-binding protein released with IP3 (IRBIT), and ezrin, was decreased in the intestinal brush border membrane (BBM) of mice with streptozotocin-induced diabetes. Treatment of diabetic mice with insulin restored intestinal NHE3 activity and fluid absorption. Molecular analysis revealed that NHE3, NHERF1, IRBIT, and ezrin form macrocomplexes, which are perturbed under diabetic conditions, and insulin administration reconstituted these macrocomplexes and restored NHE3 expression in the BBM. Silencing of NHERF1 or IRBIT prevented NHE3 trafficking to the BBM and insulin-dependent NHE3 activation. IRBIT facilitated the interaction of NHE3 with NHERF1 via protein kinase D2–dependent phosphorylation. Insulin stimulated ezrin phosphorylation, which enhanced the interaction of ezrin with NHERF1, IRBIT, and NHE3. Additionally, oral administration of lysophosphatidic acid (LPA) increased NHE3 activity and fluid absorption in diabetic mice via an insulin-independent pathway. Together, these findings indicate the importance of NHE3 in diabetic diarrhea and suggest LPA administration as a potential therapeutic strategy for management of diabetic diarrhea. PMID:26258413

  11. An inside job: how endosomal Na+/H+ exchangers link to autism and neurological disease

    PubMed Central

    Kondapalli, Kalyan C.; Prasad, Hari; Rao, Rajini

    2014-01-01

    Autism imposes a major impediment to childhood development and a huge emotional and financial burden on society. In recent years, there has been rapidly accumulating genetic evidence that links the eNHE, a subset of Na+/H+ exchangers that localize to intracellular vesicles, to a variety of neurological conditions including autism, attention deficit hyperactivity disorder (ADHD), intellectual disability, and epilepsy. By providing a leak pathway for protons pumped by the V-ATPase, eNHE determine luminal pH and regulate cation (Na+, K+) content in early and recycling endosomal compartments. Loss-of-function mutations in eNHE cause hyperacidification of endosomal lumen, as a result of imbalance in pump and leak pathways. Two isoforms, NHE6 and NHE9 are highly expressed in brain, including hippocampus and cortex. Here, we summarize evidence for the importance of luminal cation content and pH on processing, delivery and fate of cargo. Drawing upon insights from model organisms and mammalian cells we show how eNHE affect surface expression and function of membrane receptors and neurotransmitter transporters. These studies lead to cellular models of eNHE activity in pre- and post-synaptic neurons and astrocytes, where they could impact synapse development and plasticity. The study of eNHE has provided new insight on the mechanism of autism and other debilitating neurological disorders and opened up new possibilities for therapeutic intervention. PMID:25002837

  12. The Na+/H+ exchange inhibitor HOE642 prevents stress-induced epithelial barrier dysfunction.

    PubMed

    Nowak, Peter; Blaheta, Roman; Schuller, Alina; Cinatl, Jindrich; Wimmer-Greinecker, Gerhard; Moritz, Anton; Scholz, Martin

    2004-08-01

    Recently, evidence has been obtained that the Na+/H+ exchange (NHE) inhibitor HOE642 may stabilize endothelial and epithelial barrier function in vivo. However, the underlying mechanisms are not known. Therefore, we studied the influence of HOE642 on the barrier function of the epithelial cell line CaCo2. The phorbolester phorbol 12-myristate 13-acetate (PMA) was used to induce hyperpermeability of the epithelial layer which was indirectly determined by measuring the transepithelial electrical resistance (TER). Confocal laser scan microscopy (LSM) served to analyze the intracellular localization of adherens and tight junction molecules. In five independent experiments we found that HOE642 increased TER in non-treated CaCo2 cells (control: 350 +/- 28 Omega/cm2; HOE642: 444 +/- 53 Omega/cm2) and prevented PMA-induced barrier dysfunction (PMA: 33 +/- 12 Omega/cm2; PMA plus HOE642: 496 +/- 47 Omega/cm2). LSM showed that HOE642 prevented the PMA-induced disassociation of the zonula adherens molecule beta-catenin from the cell membrane and the decreased expression of the zonula occludens molecule ZO-1. From our data we conclude that HOE642 may prevent stress-induced epithelial dysfunction by stabilization of cell membrane-associated junction molecules. PMID:15254761

  13. Endosomal Na+/H+ exchanger NHE5 influences MET recycling and cell migration

    PubMed Central

    Fan, Steven Hung-Yi; Numata, Yuka; Numata, Masayuki

    2016-01-01

    Increased recycling and elevated cell surface expression of receptors serve as a mechanism for persistent receptor-mediated signaling. We show that the neuron-enriched Na+/H+ exchanger NHE5 is abundantly expressed in C6 glioma cells and plays an important part in regulating cell surface expression of the receptor tyrosine kinases MET and EGF receptor. NHE5 is associated with transferrin receptor (TfR)- and Rab11-positive recycling endosomal membranes, and NHE5 knockdown by short hairpin RNA significantly elevates pH of TfR-positive recycling endosomes. We present evidence that NHE5 facilitates MET recycling to the plasma membrane, protects MET from degradation, and modulates HGF-induced phosphatidylinositol-3-kinase and mitogen-activated protein kinase signaling. Moreover, NHE5 depletion abrogates Rac1 and Cdc42 signaling and actin cytoskeletal remodeling. We further show that NHE5 knockdown impairs directed cell migration and causes loss of cell polarity. Our study highlights a possible role of recycling endosomal pH in regulating receptor-mediated signaling through vesicular trafficking. PMID:26700318

  14. Plasma-membrane Cnh1 Na+/H+ antiporter regulates potassium homeostasis in Candida albicans.

    PubMed

    Kinclova-Zimmermannova, Olga; Sychrová, Hana

    2007-08-01

    The physiological role of Candida albicans Cnh1, a member of the Na+/H+ antiporter family, was characterized. Though CaCnh1p had broad substrate specificity and mediated efflux of at least four alkali metal cations upon heterologous expression in Saccharomyces cerevisiae, its presence in C. albicans cells was important especially for potassium homeostasis. In C. albicans, CaCnh1p tagged with GFP was localized in the plasma membrane of cells growing as both yeasts and hyphae. Deletion of CNH1 alleles did not affect tolerance to NaCl, LiCl or CsCl, but resulted in increased sensitivity to high external concentrations of KCl and RbCl. The potassium and rubidium tolerance of a cnh1 homozygous mutant was fully restored by reintegration of CNH1 into the genome. The higher sensitivity of the cnh1/cnh1 mutant to external KCl was caused by a lower K+ efflux from these cells. Together, the functional characterization of the CaCnh1 antiporter in C. albicans revealed that this antiporter plays a significant role in C. albicans physiology. It ensures potassium and rubidium tolerance and participates in the regulation of intracellular potassium content of C. albicans cells. PMID:17660424

  15. Some Remarks on the Historical Origin and Current Prospects of Holography

    NASA Astrophysics Data System (ADS)

    Sieroka, Norman

    2015-01-01

    Holography is sometimes claimed to be a fundamental principle in the advancement of quantum gravity. This paper critically evaluates this claim and provides a look back at an important historical forerunner of the modern concept of holography, which is to be found in the work of Hermann Weyl. By the same token, a brief and rather skeptical response to the recent and broad public interest in holography will be given.

  16. Optical holography applications for the zero-g Atmospheric Cloud Physics Laboratory

    NASA Technical Reports Server (NTRS)

    Kurtz, R. L.

    1974-01-01

    A complete description of holography is provided, both for the time-dependent case of moving scene holography and for the time-independent case of stationary holography. Further, a specific holographic arrangement for application to the detection of particle size distribution in an atmospheric simulation cloud chamber. In this chamber particle growth rate is investigated; therefore, the proposed holographic system must capture continuous particle motion in real time. Such a system is described.

  17. Reconstruction of images from Gabor zone plate gamma-ray holography

    NASA Astrophysics Data System (ADS)

    Unwin, Clare E.; Rew, G. A. A.; Perks, J. R.; Beynon, T. D.; Scott, Malcolm C.

    1999-09-01

    Zone plate holography is a way of obtaining 3D images from a single exposure. Unlike conventional holography, coherent radiation sources are not required. Gama ray zone plate holography can be used to image gamma rays emitted by radiopharmaceuticals used in nuclear medicine. This work concerns the computer based reconstruction of gamma ray holograms. Reconstruction algorithms including correlation and Wiener filtering are described. The images obtained using the different methods are compared.

  18. Higher-spin theory and holography

    NASA Astrophysics Data System (ADS)

    Gaberdiel, Matthias; Vasiliev, Mikhail

    2013-05-01

    , this has triggered a significant amount of activity in this general area. Among other things, the constraints that are implied by the higher-spin symmetries were analysed (see the paper by Maldacena and Zhiboedov in this issue [9]), and a fairly concrete proposal for how higher-spin theories are related to string theory was made (see the paper by Chang, Minwalla, Sharma and Yin in this issue [10]). Furthermore, a lower dimensional version of the conjecture was put forward by Gaberdiel and Gopakumar [11] that was subsequently also checked in some detail. These dualities hold the promise of offering insights into the inner workings of the AdS/CFT correspondence since they are complex enough to capture the essence of the duality, while at the same time being sufficiently simple in order to allow for a detailed analysis. Moreover, the methods specifically developed in higher-spin theory may be useful for understanding a general mechanism underlying holography, both in higher-spin models and beyond (see the paper by Vasiliev in this issue [12]). Another fascinating aspect of these higher-spin theories lies in the fact that the higher-spin symmetries mix generically fields of different spin, and in particular, the spin-2 metric and higher-spin excitations are related to one another by gauge transformations. As a result, higher-spin theories require a modification of the standard framework of Riemannian geometry since the usual diffeomorphism-invariant tensors are not gauge invariant any longer. In particular, higher-spin theories may therefore open the way towards understanding fundamental concepts of space-time geometry; for example, they may well have key lessons in store for how string theory resolves space-time singularities. In this issue we have collected together a number of review papers, summarizing the aforementioned recent developments, as well as research papers indicating current directions of interest in the study of higher-spin gauge theories. We hope that it

  19. QCD and Light-Front Holography

    SciTech Connect

    Brodsky, Stanley J.; de Teramond, Guy F.; /Costa Rica U.

    2010-10-27

    The soft-wall AdS/QCD model, modified by a positive-sign dilaton metric, leads to a remarkable one-parameter description of nonperturbative hadron dynamics. The model predicts a zero-mass pion for zero-mass quarks and a Regge spectrum of linear trajectories with the same slope in the leading orbital angular momentum L of hadrons and the radial quantum number N. Light-Front Holography maps the amplitudes which are functions of the fifth dimension variable z of anti-de Sitter space to a corresponding hadron theory quantized on the light front. The resulting Lorentz-invariant relativistic light-front wave equations are functions of an invariant impact variable {zeta} which measures the separation of the quark and gluonic constituents within the hadron at equal light-front time. The result is to a semi-classical frame-independent first approximation to the spectra and light-front wavefunctions of meson and baryon light-quark bound states, which in turn predict the behavior of the pion and nucleon form factors. The theory implements chiral symmetry in a novel way: the effects of chiral symmetry breaking increase as one goes toward large interquark separation, consistent with spectroscopic data, and the the hadron eigenstates generally have components with different orbital angular momentum; e.g., the proton eigenstate in AdS/QCD with massless quarks has L = 0 and L = 1 light-front Fock components with equal probability. The soft-wall model also predicts the form of the non-perturbative effective coupling {alpha}{sub s}{sup AdS} (Q) and its {beta}-function which agrees with the effective coupling {alpha}{sub g1} extracted from the Bjorken sum rule. The AdS/QCD model can be systematically improved by using its complete orthonormal solutions to diagonalize the full QCD light-front Hamiltonian or by applying the Lippmann-Schwinger method in order to systematically include the QCD interaction terms. A new perspective on quark and gluon condensates is also reviewed.

  20. Cloning and identification of a novel NhaD-type Na+/H+ antiporter from metagenomic DNA of the halophilic bacteria in soil samples around Daban Salt Lake.

    PubMed

    Zhang, Hua; Wang, Zhenhui; Wang, Lei; Mu, Ren; Zou, Zhi; Yuan, Kun; Wang, Yuekun; Wu, Haiping; Jiang, Juquan; Yang, Lifu

    2014-01-01

    In this study, metagenomic DNA was screened for the Na(+)/H(+) antiporter gene from the halophilic bacteria in Daban Salt Lake by selection in Escherichia coli KNabc lacking three major Na(+)/H(+) antiporters. One gene designated as Hb_nhaD encoding a novel NhaD-type Na(+)/H(+) antiporter was finally cloned. The presence of Hb_NhaD conferred tolerance of E. coli KNabc to up to 0.5 M NaCl and 0.2 M LiCl, and an alkaline pH. Hb_NhaD has the highest identity (70.6%) with a putative NhaD-type Na(+)/H(+) antiporter from an uncharacterized Clostridiaceae species, and also has lower identity with known NhaD-type Na(+)/H(+) antiporters from Halomonas elongata (20.8%), Alkalimonas amylolytica (19.0%), Vibrio parahaemolyticus (18.9%) and Vibrio cholerae (18.7 %). pH-dependent Na(+)(Li(+))/H(+) antiport activity was detected from everted membrane vesicles prepared from E. coli KNabc carrying Hb_nhaD. Hb_NhaD exhibited very high Na(+)(Li(+))/H(+) antiport activity over a wide pH range from 6.5 to 9.0 with the highest activity at pH 7.0 which is significantly different from those of the above known NhaD-type Na(+)/H(+) antiporters. Also, the apparent K m values of Hb_NhaD for Na(+) and Li(+) at pH 7.0 were determined to be 1.31 and 2.16, respectively. Based on the above results, we proposed that Hb_NhaD should be categorized as a novel NhaD-type Na(+)/H(+) antiporter. PMID:24297704

  1. Local magnetic structure determination using polarized neutron holography

    SciTech Connect

    Szakál, Alex Markó, Márton Cser, László

    2015-05-07

    A unique and important property of the neutron is that it possesses magnetic moment. This property is widely used for determination of magnetic structure of crystalline samples observing the magnetic components of the diffraction peaks. Investigations of diffraction patterns give information only about the averaged structure of a crystal but for discovering of local spin arrangement around a specific (e.g., impurity) nucleus remains still a challenging problem. Neutron holography is a useful tool to investigate the local structure around a specific nucleus embedded in a crystal lattice. The method has been successfully applied experimentally in several cases using non-magnetic short range interaction of the neutron and the nucleus. A mathematical model of the hologram using interaction between magnetic moment of the atom and the neutron spin for polarized neutron holography is provided. Validity of a polarized neutron holographic experiment is demonstrated by applying the proposed method on model systems.

  2. The SHIVA Project: Spaceflight Holography in a Virtual Apparatus

    NASA Technical Reports Server (NTRS)

    Trolinger, Jim; Rogers, Jan; Witherow, William; Coimbra, Carlos; Rangel, Roger; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    The poster summarizes theoretical and experimental concepts used in the development of the proposed NASA flight experiment SHIVA (Spaceflight Holography in a Virtual Apparatus). SHIVA exploits a unique holography-based, diagnostics tools to understand the behavior of small particles subjected to transient accelerations. Flight experiment protocols and apparatus will test model equations, characterize the acceleration environment and other microgravity phenomena. The primary objective of SHIVA is to enhance the current understanding of complex dynamics of small particles subjected to transient microgravity conditions. Existing theory did not fully describe the movement of particles in fluids in the microgravity environment. Results from recent ground-based experiments and comparison with the model recently developed by Rangel and Coimbra are presented.

  3. Monolithic focused reference beam X-ray holography

    PubMed Central

    Geilhufe, J.; Pfau, B.; Schneider, M.; Büttner, F.; Günther, C. M.; Werner, S.; Schaffert, S.; Guehrs, E.; Frömmel, S.; Kläui, M.; Eisebitt, S.

    2014-01-01

    Fourier transform holography is a highly efficient and robust imaging method, suitable for single-shot imaging at coherent X-ray sources. In its common implementation, the image contrast is limited by the reference signal generated by a small pinhole aperture. Increased pinhole diameters improve the signal, whereas the resolution is diminished. Here we report a new concept to decouple the spatial resolution from the image contrast by employing a Fresnel zone plate to provide the reference beam. Superimposed on-axis images of distinct foci are separated with a novel algorithm. Our method is insensitive to mechanical drift or vibrations and allows for long integration times common at low-flux facilities like high harmonic generation sources. The application of monolithic focused reference beams improves the efficiency of high-resolution X-ray Fourier transform holography beyond all present approaches and paves the path towards sub-10 nm single-shot X-ray imaging. PMID:24394675

  4. Monolithic focused reference beam X-ray holography

    NASA Astrophysics Data System (ADS)

    Geilhufe, J.; Pfau, B.; Schneider, M.; Büttner, F.; Günther, C. M.; Werner, S.; Schaffert, S.; Guehrs, E.; Frömmel, S.; Kläui, M.; Eisebitt, S.

    2014-01-01

    Fourier transform holography is a highly efficient and robust imaging method, suitable for single-shot imaging at coherent X-ray sources. In its common implementation, the image contrast is limited by the reference signal generated by a small pinhole aperture. Increased pinhole diameters improve the signal, whereas the resolution is diminished. Here we report a new concept to decouple the spatial resolution from the image contrast by employing a Fresnel zone plate to provide the reference beam. Superimposed on-axis images of distinct foci are separated with a novel algorithm. Our method is insensitive to mechanical drift or vibrations and allows for long integration times common at low-flux facilities like high harmonic generation sources. The application of monolithic focused reference beams improves the efficiency of high-resolution X-ray Fourier transform holography beyond all present approaches and paves the path towards sub-10nm single-shot X-ray imaging.

  5. Underwater visual inspection and measurement using optical holography

    NASA Astrophysics Data System (ADS)

    Watson, John

    In offshore oil and gas exploration, visual inspection and measurement often has to be carried out under conditions of poor visibility and at great depths. Recording a hologram of an underwater scene with its subsequent replay in the laboratory could provide enormous benefits to the inspection engineer. When replayed in the real image mode, dimensional measurement may be performed directly on the image formed in real space using, for example, measuring microscopy or TV cameras. Potential applications include general archiving, measurement of corrosion pitting and cracking, examination and measurement of damage sites, structural profiling and examination of marine growth. In this paper, we outline the general concepts of underwater holography. A résumé is given of the work undertaken in the past, the problems experienced and their solution and an indication of our general direction leading to the establishment of holography as a unique method of subsea inspection.

  6. Resolution enhancement phase-contrast imaging by microsphere digital holography

    NASA Astrophysics Data System (ADS)

    Wang, Yunxin; Guo, Sha; Wang, Dayong; Lin, Qiaowen; Rong, Lu; Zhao, Jie

    2016-05-01

    Microsphere has shown the superiority of super-resolution imaging in the traditional 2D intensity microscope. Here a microsphere digital holography approach is presented to realize the resolution enhancement phase-contrast imaging. The system is designed by combining the microsphere with the image-plane digital holography. A microsphere very close to the object can increase the resolution by transforming the object wave from the higher frequency to the lower one. The resolution enhancement amplitude and phase images can be retrieved from a single hologram. The experiments are carried on the 1D and 2D gratings, and the results demonstrate that the observed resolution has been improved, meanwhile, the phase-contrast image is obtained. The proposed method can improve the transverse resolution in all directions based on a single exposure. Furthermore, this system has extended the application of the microsphere from the conventional 2D microscopic imaging to 3D phase-contrast microscopic imaging.

  7. Three-dimensional optical holography using a plasmonic metasurface

    PubMed Central

    Huang, Lingling; Chen, Xianzhong; Mühlenbernd, Holger; Zhang, Hao; Chen, Shumei; Bai, Benfeng; Tan, Qiaofeng; Jin, Guofan; Cheah, Kok-Wai; Qiu, Cheng-Wei; Li, Jensen; Zentgraf, Thomas; Zhang, Shuang

    2013-01-01

    Benefitting from the flexibility in engineering their optical response, metamaterials have been used to achieve control over the propagation of light to an unprecedented level, leading to highly unconventional and versatile optical functionalities compared with their natural counterparts. Recently, the emerging field of metasurfaces, which consist of a monolayer of photonic artificial atoms, has offered attractive functionalities for shaping wave fronts of light by introducing an abrupt interfacial phase discontinuity. Here we realize three-dimensional holography by using metasurfaces made of subwavelength metallic nanorods with spatially varying orientations. The phase discontinuity takes place when the helicity of incident circularly polarized light is reversed. As the phase can be continuously controlled in each subwavelength unit cell by the rod orientation, metasurfaces represent a new route towards high-resolution on-axis three-dimensional holograms with a wide field of view. In addition, the undesired effect of multiple diffraction orders usually accompanying holography is eliminated.

  8. The use of digital/electronic holography for biological applications

    NASA Astrophysics Data System (ADS)

    Sun, Hongyue; Player, Michael A.; Watson, John; Hendry, David C.; Perkins, Rupert G.; Gust, Giselher; Paterson, David M.

    2005-06-01

    This paper presents the performance of electronic holography for imaging applications of biological and medical interest involving turbid media. It demonstrates that digital holography is useful for biological studies in the areas of estuary sediment erosion and imaging unstained living cells. In particular, we demonstrate the recording geometries of classical 'in-line' back illumination using a collimated beam for measuring micro-particles eroded in a cylindrical observation chamber; we also demonstrate a phase contrast set-up using a magnifying lens for observing biomedical micro-objects of unstained living cells in physiological saline. Practical results are presented for the studies of sediment erosion and transport, which provide information about how polymeric substances produced by the organisms in sediment and erosion shear velocity affect the sediment particle size when erosive stresses are applied to sediment beds.

  9. Art-science, beauty-reason and holography

    NASA Astrophysics Data System (ADS)

    Jeong, T. H.

    2013-02-01

    Display holography holds a distinction that makes it appealing to a wide audience. It can be appreciated at a deep level by people of all ages and in all fields of endeavor. It provides a unique opportunity for us to gather in an intimate location to learn, enjoy, and enlighten one another. This paper offers demonstrations to explore the relationships between art and science, esthetics and mathematics, and the dualities that exist in nature. On the practical level, a visual model for deep understanding of holography and a proposal for "making holograms that sell" will be presented. In writing this article, the author acknowledges the fact that for this symposium, a Proceeding will be published as well as a set of audio-visual recordings. With that in mind, this article represents largely the printable contents, leaving the audio-visual part as "performance" to be electronically recorded.

  10. Phase-shifting real-time holography with photorefractive crystals

    NASA Astrophysics Data System (ADS)

    Gesualdi, M. R. R.; Soga, D.; Muramatsu, M.

    2006-01-01

    The phase-shifting interferometry techniques is a well-known technique which has been used with great success in optical profilers, micro-displacements, micro-deformations and others applications in Non-Destructive Test in basic research, engineering and biotechnology areas. This work presents our Advances in Phase-Shifting Real-Time Holography using Photorefractive Sillenite. And we have obtained quantitative results in many applications in measurements of micro-rotation, micro-displacements, deformation, surface contouring and whole lens wave-optics. The real-time holography process is doing using the photorefractive Bi 12SiO 20 crystal recording medium, where the phase-shifting 4-frames method for obtained the phase map, this was filtered by sin/cos filter and was applied the unwrapping process. The experimental results agree with the expected one in these applications and with promises potentialities of this method for studies with in situ visualization, monitoring and analysis.

  11. Na+/H+ Exchanger Isoform 1-Induced Osteopontin Expression Facilitates Cardiomyocyte Hypertrophy

    PubMed Central

    Mohamed, Iman A.; Gadeau, Alain-Pierre; Fliegel, Larry; Lopaschuk, Gary; Mlih, Mohamed; Abdulrahman, Nabeel; Fillmore, Natasha; Mraiche, Fatima

    2015-01-01

    Enhanced expression and activity of the Na+/H+ exchanger isoform 1 (NHE1) has been implicated in cardiomyocyte hypertrophy in various experimental models. The upregulation of NHE1 was correlated with an increase in osteopontin (OPN) expression in models of cardiac hypertrophy (CH), and the mechanism for this remains to be delineated. To determine whether the expression of active NHE1-induces OPN and contributes to the hypertrophic response in vitro, cardiomyocytes were infected with the active form of the NHE1 adenovirus or transfected with OPN silencing RNA (siRNA-OPN) and characterized for cardiomyocyte hypertrophy. Expression of NHE1 in cardiomyocytes resulted in a significant increase in cardiomyocyte hypertrophy markers: cell surface area, protein content, ANP mRNA and expression of phosphorylated-GATA4. NHE1 activity was also significantly increased in cardiomyocytes expressing active NHE1. Interestingly, transfection of cardiomyocytes with siRNA-OPN significantly abolished the NHE1-induced cardiomyocyte hypertrophy. siRNA-OPN also significantly reduced the activity of NHE1 in cardiomyocytes expressing NHE1 (68.5±0.24%; P<0.05), confirming the role of OPN in the NHE1-induced hypertrophic response. The hypertrophic response facilitated by NHE1-induced OPN occurred independent of the extracellular-signal-regulated kinases and Akt, but required p90-ribosomal S6 kinase (RSK). The ability of OPN to facilitate the NHE1-induced hypertrophic response identifies OPN as a potential therapeutic target to reverse the hypertrophic effect induced by the expression of active NHE1. PMID:25884410

  12. Na+/H+ exchanger 1 deficiency alters gene expression in mouse brain.

    PubMed

    Zhou, Dan; Xue, Jin; Gavrialov, Orit; Haddad, Gabriel G

    2004-08-11

    Na(+)/H(+) exchanger 1 (NHE1) is well known to function as a major regulator of intracellular pH (pH(i)). It is activated by low pH(i) and exchanges extracellular Na(+) for intracellular H(+) to maintain cellular homeostasis. Despite the fact that we now have evidence suggesting other roles for NHE1, there has been no comprehensive study investigating its role as a signaling molecule. Toward this aim, we used in this study NHE1 null mutant mice and cDNA microarrays to investigate the effects of NHE1 on global gene expression in various regions of the brain, e.g., cortex, hippocampus, brain stem-diencephalon, and cerebellum. We found that a total of 35 to 79 genes were up- or downregulated in each brain region, with the majority being downregulated. The effect of NHE1 null mutation on gene expression is region specific, and only 11 genes were changed in all brain regions studied. Further analysis of the cis-regulatory regions of downregulated genes revealed that transcription suppressors, BCL6 and E4BP4, were probable candidates that mediated the inhibitory effect of NHE1 null mutation. One of the genes, MCT-13, was not only downregulated in the NHE1 null mutant brain but also in tissue cultures treated with an NHE1 inhibitor. We conclude that 1) a relatively small number of genes were altered in the NHE1 null mouse brain; 2) the effects of NHE1 null mutation on gene expression are region specific; and 3) several genes implicated in neurodegeneration have altered expression, potentially offering a molecular explanation for the phenotype of the NHE1 null mouse. PMID:15306696

  13. Molecular characterization and expression analysis of the mulberry Na(+)/H(+) exchanger gene family.

    PubMed

    Cao, Boning; Long, Dingpei; Zhang, Meng; Liu, Changying; Xiang, Zhonghuai; Zhao, Aichun

    2016-02-01

    Na(+)/H(+) exchangers (NHXs) have important roles in cellular pH, and Na(+) and K(+) homeostasis in plants. Mulberry is not only an important traditional economic woody plant known for its leaves, which are the exclusive food source of the silkworm Bombyx mori, but it can also adapt to many different adverse conditions, including saline environments. However, little is known about the NHXs in this important perennial tree. In this study, we identified and cloned seven putative NHX gene family members from Morus atropurpurea based on a genome-wide analysis of the Morus genome database. A phylogenetic analysis and genomic organization of mulberry NHXs suggested that the mulberry NHX family forms three distinct subgroups. Transcriptome data and real-time PCR of different mulberry varieties under normal culture conditions revealed that the mulberry NHX family has a different tissue-specific pattern in the two mulberry species. The MaNHX genes' expression analyses under different stresses (salt and drought) and signal molecules (abscisic acid, salicylic acid, hydrogen peroxide and methyl jasmonate) revealed that MaNHXs not only could be induced by salt, drought and abscisic acid as describe in the literature, but were also induced by other signal molecules, which indicated that MaNHX members exhibited diverse and complicated expression patterns in different mulberry tissues under various abiotic stresses, phytohormones and plant signaling molecules. Our results provide some insights into new and emerging cellular and physiological functions of this group of H(+)-coupled cation exchangers, beyond their function in salt tolerance, and also provide the basis for further characterizations of MaNHXs' physiological functions. PMID:26730882

  14. Microwave Holography Helps Improve Performance Of Large Antennas

    NASA Technical Reports Server (NTRS)

    Rochblatt, David J.

    1993-01-01

    Report describes use of microwave holography and related techniques of measurement and computation for diagnostics, analysis, and performance improvement of large microwave reflector antennas over all operating frequencies. Technique based on Fourier-transform relationship between complex far-field radiation pattern of antenna at small angles off boresight axis, and complex electromagnetic antenna aperture field distribution, as function of position, expressed in terms of equivalent surface current density.

  15. Quantitative phase imaging by three-wavelength digital holography

    SciTech Connect

    Mann, Christopher J; Bingham, Philip R; Tobin Jr, Kenneth William; Paquit, Vincent C

    2008-01-01

    Three-wavelength digital holography is applied to obtain surface height measurements over several microns of range, while simultaneously maintaining the low noise precision of the single wavelength phase measurement. The precision is preserved by the use of intermediate synthetic wavelength steps generated from the three wavelengths and the use of hierarchical optical phase unwrapping. As the complex wave-front of each wavelength can be captured simultaneously in one digital image, real-time performance is achievable.

  16. The microwave holography system for the Sardinia Radio Telescope

    NASA Astrophysics Data System (ADS)

    Serra, G.; Bolli, P.; Busonera, G.; Pisanu, T.; Poppi, S.; Gaudiomonte, F.; Zacchiroli, G.; Roda, J.; Morsiani, M.; López-Pérez, J. A.

    2012-09-01

    Microwave holography is a well-established technique for mapping surface errors of large reflector antennas, particularly those designed to operate at high frequencies. We present here a holography system based on the interferometric method for mapping the primary reflector surface of the Sardinia Radio Telescope (SRT). SRT is a new 64-m-diameter antenna located in Sardinia, Italy, equipped with an active surface and designed to operate up to 115 GHz. The system consists mainly of two radio frequency low-noise coherent channels, designed to receive Ku-band digital TV signals from geostationary satellites. Two commercial prime focus low-noise block converters are installed on the radio telescope under test and on a small reference antenna, respectively. Then the signals are amplified, filtered and downconverted to baseband. An innovative digital back-end based on FPGA technology has been implemented to digitize two 5 MHz-band signals and calculate their cross-correlation in real-time. This is carried out by using a 16-bit resolution ADCs and a FPGA reaching very large amplitude dynamic range and reducing post-processing time. The final holography data analysis is performed by CLIC data reduction software developed within the Institut de Radioastronomie Millimétrique (IRAM, Grenoble, France). The system was successfully tested during several holography measurement campaigns, recently performed at the Medicina 32-m radio telescope. Two 65-by-65 maps, using an on-the-fly raster scan with on-source phase calibration, were performed pointing the radio telescope at 38 degrees elevation towards EUTELSAT 7A satellite. The high SNR (greater than 60 dB) and the good phase stability led to get an accuracy on the surface error maps better than 150 μm RMS.

  17. Holography and entropy bounds in the plane wave matrix model

    SciTech Connect

    Bousso, Raphael; Mints, Aleksey L.

    2006-06-15

    As a quantum theory of gravity, matrix theory should provide a realization of the holographic principle, in the sense that a holographic theory should contain one binary degree of freedom per Planck area. We present evidence that Bekenstein's entropy bound, which is related to area differences, is manifest in the plane wave matrix model. If holography is implemented in this way, we predict crossover behavior at strong coupling when the energy exceeds N{sup 2} in units of the mass scale.

  18. Entanglement, Holography, and the Quantum Phases of Matter

    SciTech Connect

    Sachdev, Subir

    2012-11-07

    Electrons in many interesting materials, such as the high temperature superconductors, exhibit low energy states with complex varieties of quantum entanglement. I will describe how the methods of holography, drawn from string theory, have given us a new tool to describe such states, by relating them to theories of gravitation in curved spacetimes with an extra dimension. I will discuss the impact of such ideas on studies of quantum phase transitions, and of novel metals.

  19. Bi-local holography in the SYK model

    NASA Astrophysics Data System (ADS)

    Jevicki, Antal; Suzuki, Kenta; Yoon, Junggi

    2016-07-01

    We discuss large N rules of the Sachdev-Ye-Kitaev model and the bi-local representation of holography of this theory. This is done by establishing 1 /N Feynman rules in terms of bi-local propagators and vertices, which can be evaluated following the recent procedure of Polchinski and Rosenhaus. These rules can be interpreted as Witten type diagrams of the dual AdS theory, which we are able to define at IR fixed point and off.

  20. Advances in far-field holography - Theory and applications

    NASA Astrophysics Data System (ADS)

    Thompson, B. J.; Dunn, P.

    1980-05-01

    The development status of far-field holography is reviewed, with emphasis on such applications of single and multiple pulse methods as agricultural pest control, cavitation studies, and the evaluation of fuel droplet size and burning in engines. It is shown that resolution remains a major consideration and noise a major limiting factor, with parameters such as film resolution, format and processing, and spatial and temporal coherence meriting further consideration.

  1. Multiplex Holography For The Display Of Three-Dimensional Information

    NASA Astrophysics Data System (ADS)

    Drinkwater, John; Hart, Stephen

    1987-10-01

    A system based on multiplex holography has been developed for the display and storage of three-dimensional information. Volume ('stack') multiplex holograms have been produced for viewing on a novel white light display device based on dispersion compensation. The image processing and holographic techniques developed to optimise these results are described. The demonstration of potential applications of the displays for data from medical imaging, analytical techniques such as electron microscopy and scientific data analysis is detailed.

  2. Acoustic transducer for acoustic microscopy

    DOEpatents

    Khuri-Yakub, Butrus T.; Chou, Ching H.

    1990-01-01

    A shear acoustic transducer-lens system in which a shear polarized piezoelectric material excites shear polarized waves at one end of a buffer rod having a lens at the other end which excites longitudinal waves in a coupling medium by mode conversion at selected locations on the lens.

  3. Acoustic transducer for acoustic microscopy

    DOEpatents

    Khuri-Yakub, B.T.; Chou, C.H.

    1990-03-20

    A shear acoustic transducer-lens system is described in which a shear polarized piezoelectric material excites shear polarized waves at one end of a buffer rod having a lens at the other end which excites longitudinal waves in a coupling medium by mode conversion at selected locations on the lens. 9 figs.

  4. Spatial crystal imaging by means of atomic electron holography

    NASA Astrophysics Data System (ADS)

    Luehr, Tobias; Winkelmann, Aimo; Nolze, Gert; Westphal, Carsten

    2015-03-01

    The determination of atom structures is the key for the understanding of basic functional properties of matter or for designing new high-tech materials. For structure determination, holography is a very attractive option, since this method enables lensless three-dimensional imaging. In principle, x-ray photoelectron diffraction (XPD) experiments correspond to a microscopic holography setup. The electron diffraction pattern is highly sensitive to the local structure of the emitter environment, since the emitting atom is located in the near-field of the scattering atoms. Hence, holographic reconstructions of XPD-patterns should yield a spatial image of the sample's atom arrangement. However, anisotropic electron scattering and multiple scattering effects generally cause strong artifacts in the reconstruction. In this contribution we show how to circumvent this problem with electrons at kinetic energies of Ekin >= 10 keV. The resulting spatial images contain hundreds of clearly separated atoms at their correct locations. Furthermore, XPD-patterns allow an element-specific assignment of the reconstructed atoms within the image. This is the first demonstration of true atom imaging following Dennis Gabor's idea of electron holography.

  5. Ultra-realistic 3-D imaging based on colour holography

    NASA Astrophysics Data System (ADS)

    Bjelkhagen, H. I.

    2013-02-01

    A review of recent progress in colour holography is provided with new applications. Colour holography recording techniques in silver-halide emulsions are discussed. Both analogue, mainly Denisyuk colour holograms, and digitally-printed colour holograms are described and their recent improvements. An alternative to silver-halide materials are the panchromatic photopolymer materials such as the DuPont and Bayer photopolymers which are covered. The light sources used to illuminate the recorded holograms are very important to obtain ultra-realistic 3-D images. In particular the new light sources based on RGB LEDs are described. They show improved image quality over today's commonly used halogen lights. Recent work in colour holography by holographers and companies in different countries around the world are included. To record and display ultra-realistic 3-D images with perfect colour rendering are highly dependent on the correct recording technique using the optimal recording laser wavelengths, the availability of improved panchromatic recording materials and combined with new display light sources.

  6. Active phase compensation system for fiber optic holography

    NASA Technical Reports Server (NTRS)

    Mercer, Carolyn R.; Beheim, Glenn

    1989-01-01

    Fiber optic delivery systems promise to extend the application of holography to severe environments by simplifying test configurations and permitting the laser to be remotely placed in a more benign location. However, the introduction of optical fiber leads to phase stability problems. Environmental effects cause the pathlengths of the fibers to change randomly, preventing the formation of stationary interference patterns which are required for holography. An active phase control system has been designed and used with an all-fiber optical system to stabilize the phase difference between light emitted from two fibers, and to step the phase difference by 90 deg without applying any constraints on the placement of the fibers. The accuracy of the phase steps is shown to be better than 0.02 deg., and a stable phase difference can be maintained for 30 min. This system can be applied to both conventional and electro-optic holography, as well as to any system where the maintenance of an accurate phase difference between two coherent beams is required.

  7. Active phase compensation system for fiber optic holography

    NASA Technical Reports Server (NTRS)

    Mercer, Carolyn R.; Beheim, Glenn

    1988-01-01

    Fiber optic delivery systems promise to extend the application of holography to severe environments by simplifying test configurations and permitting the laser to be remotely placed in a more benign location. However, the introduction of optical fiber leads to phase stability problems. Environmental effects cause the pathlengths of the fibers to change randomly, preventing the formation of stationary interference patterns which are required for holography. An active phase control system has been designed and used with an all-fiber optical system to stabilize the phase difference between light emitted from two fibers, and to step the phase difference by 90 deg without applying any constraints on the placement of the fibers. The accuracy of the phase steps is shown to be better than 0.02 deg., and a stable phase difference can be maintained for 30 min. This system can be applied to both conventional and electro-optic holography, as well as to any system where the maintenance of an accurate phase difference between two coherent beams is required.

  8. Ultra-realistic imaging: a new beginning for display holography

    NASA Astrophysics Data System (ADS)

    Bjelkhagen, Hans I.; Brotherton-Ratcliffe, David

    2014-02-01

    Recent improvements in key foundation technologies are set to potentially transform the field of Display Holography. In particular new recording systems, based on recent DPSS and semiconductor lasers combined with novel recording materials and processing, have now demonstrated full-color analogue holograms of both lower noise and higher spectral accuracy. Progress in illumination technology is leading to a further major reduction in display noise and to a significant increase of the clear image depth and brightness of such holograms. So too, recent progress in 1-step Direct-Write Digital Holography (DWDH) now opens the way to the creation of High Virtual Volume Displays (HVV) - large format full-parallax DWDH reflection holograms having fundamentally larger clear image depths. In a certain fashion HVV displays can be thought of as providing a high quality full-color digital equivalent to the large-format laser-illuminated transmission holograms of the sixties and seventies. Back then, the advent of such holograms led to much optimism for display holography in the market. However, problems with laser illumination, their monochromatic analogue nature and image noise are well cited as being responsible for their failure in reality. Is there reason for believing that the latest technology improvements will make the mark this time around? This paper argues that indeed there is.

  9. Managing and directing innovation in the holography business

    NASA Astrophysics Data System (ADS)

    Gortych, Joseph E.; Abilock, Harold

    2006-02-01

    The intellectual property (IP) space associated with core high-tech innovations, such as holography, tends to rapidly expand in many directions as new applications and improvements to the core technology are realized. Patents soon start to quickly fill regions of the IP space to varying densities, often before any commercial product is available. Complicating matters is the fact that the patents typically range wildly in quality and business value for a host of reasons, not the least of which is that many high-tech companies lack an IP strategy designed to drive their R and D and patenting efforts. IP-savvy high-tech companies are relying more and more on some type of IP space analysis to more fully understand the IP landscape in which they do business. However, after an IP space analysis is performed, it needs to be integrated into a larger IP management system driven by an IP strategy. This paper examines the role of a best-practice IP management system in a high-tech business and how it can be used in conjunction with a holography IP space analysis to strategically manage and direct innovation in the holography business.

  10. Direct Atom Imaging by Chemical-Sensitive Holography.

    PubMed

    Lühr, Tobias; Winkelmann, Aimo; Nolze, Gert; Krull, Dominique; Westphal, Carsten

    2016-05-11

    In order to understand the physical and chemical properties of advanced materials, functional molecular adsorbates, and protein structures, a detailed knowledge of the atomic arrangement is essential. Up to now, if subsurface structures are under investigation, only indirect methods revealed reliable results of the atoms' spatial arrangement. An alternative and direct method is three-dimensional imaging by means of holography. Holography was in fact proposed for electron waves, because of the electrons' short wavelength at easily accessible energies. Further, electron waves are ideal structure probes on an atomic length scale, because electrons have a high scattering probability even for light elements. However, holographic reconstructions of electron diffraction patterns have in the past contained severe image artifacts and were limited to at most a few tens of atoms. Here, we present a general reconstruction algorithm that leads to high-quality atomic images showing thousands of atoms. Additionally, we show that different elements can be identified by electron holography for the example of FeS2. PMID:27070050

  11. In-line particle field holography at Pegasus

    SciTech Connect

    Sorenson, D.S.; Obst, A.; King, N.S.P.

    1995-09-01

    An in-line holographic imaging system has been developed for hydrodynamic experiments at the Pegasus facility located at Los Alamos National Laboratory. Holography offers the unique capability to record distributions of particles over a three dimensional volume. The system to be discussed is used to measure particle distributions of ejecta emitted after a cylindrical aluminum liner (5.0 cm in diameter, 2.0 cm high) impacts a target (3.0 cm in diameter). The ejecta emerges from the target traveling up to 7mm/{micro}s and moves toward the axial center of the system where the holographic imaging is performed. In-line holography is particularly suited for the Pegasus pulsed power facility where the geometry restrictions make off axis holography impractical. In order to record the fast moving particles a frequency-doubled Nd:-YAG laser system has been implemented which produces a 80 ps 20 millijoule pulse at 532 nm. An optical relay system composed of a Fourier optical lens pair has been developed which is placed 4.0 cm from the center of the region of interest. This relay lens pair forms an intermediate image 32 cm from the object plane and the hologram is placed 4cm downstream of the intermediate image. The holographic system and resolution capability are discussed.

  12. Quantum holography: magnetic resonance tomography and gravitational wavelets

    NASA Astrophysics Data System (ADS)

    Binz, Ernst; Schempp, Walter

    2000-10-01

    Quantum holography is a well established theory of mathematical physics based on harmonic analysis on the Heisenberg Lie group G. The geometric quantization is performed by projectivization of the complexified coadjoint orbit picture of the unitary dual G of G in order to achieve a geometric adjustment to special relativity theory. It admits applications to various imaging modalities such as synthetic aperture radar (SAR), and most importantly for the field of non-invasive medical diagnosis, to the clinical imaging modality of magnetic resonance tomography (MRI). Quantum holography explains the quantum teleportation phenomenon through Einstein-Podolsky-Rosen (EPR) channels which is a consequence of the non-locality of quantum physics. It specifically reveals what was before unobservable in special relativity, namely the light in flight (LIF) recording processing by ultra fast laser pulse trains. Finally, it provides a Lie group theoretical approach to the Kruskal coordinatized Schwarzschild manifold of quantum cosmology with large scale applications to general relativity theory such as gravitational instanton symmetries and the theory of black holes. The direct spinorial detection of gravitational wavelets emitted by the binary radio pulsar PSR 1913+16 will also be based on the principles of quantum holography.

  13. Mapping the electrostatic potential of Au nanoparticles using hybrid electron holography.

    PubMed

    Ozsoy-Keskinbora, Cigdem; Boothroyd, Chris B; Dunin-Borkowski, Rafal E; van Aken, Peter A; Koch, Christoph T

    2016-06-01

    Electron holography is a powerful technique for characterizing electrostatic potentials, charge distributions, electric and magnetic fields, strain distributions and semiconductor dopant distributions with sub-nm spatial resolution. Mapping internal electrostatic and magnetic fields within nanoparticles and other low-dimensional materials by TEM requires both high spatial resolution and high phase sensitivity. Carrying out such an analysis fully quantitatively is even more challenging, since artefacts such as dynamical electron scattering may strongly affect the measurement. In-line electron holography, one of the variants of electron holography, features high phase sensitivity at high spatial frequencies, but suffers from inefficient phase recovery at low spatial frequencies. Off-axis electron holography, in contrast, can recover low spatial frequency phase information much more reliably, but is less effective in retrieving phase information at high spatial frequencies when compared to in-line holography. We investigate gold nanoparticles using hybrid electron holography at both atomic-resolution and intermediate magnification. Hybrid electron holography is a novel technique that synergistically combines off-axis and in-line electron holography, allowing the measurement of the complex wave function describing the scattered electrons with excellent signal-to-noise properties at both high and low spatial frequencies. The effect of dynamical electron scattering is minimized by beam tilt averaging. PMID:27043767

  14. Heterodyne holography with full control of both the signal and reference arms.

    PubMed

    Gross, Michel

    2016-01-20

    Heterodyne holography is a variant of phase-shifting holography in which the reference and signal arms are controlled by acousto-optic modulators. In this review paper, we will briefly describe the method and its properties, and we will illustrate its advantages in experimental applications. PMID:26835961

  15. Holography of human pathologic specimens with continuous-beam lasers through plastination

    NASA Astrophysics Data System (ADS)

    Myers, M. Bert; Bickley, Harmon

    1991-07-01

    Since evaporation of cellular water leads to shrinkage and motion, holography of human tissue specimens is generally possible only with pulsed lasers. Plastination is a preservation technique in which cellular water is removed and replaced with a curable polymer. This preserves the tissue, including even the cellular anatomy, and renders the specimen rigid enough for holography with continuous beam lasers.

  16. Medical Acoustics

    NASA Astrophysics Data System (ADS)

    Beach, Kirk; Dunmire, Barbrina

    Medical acoustics can be subdivided into diagnostics and therapy. Diagnostics are further separated into auditory and ultrasonic methods, and both employ low amplitudes. Therapy (excluding medical advice) uses ultrasound for heating, cooking, permeablizing, activating and fracturing tissues and structures within the body, usually at much higher amplitudes than in diagnostics. Because ultrasound is a wave, linear wave physics are generally applicable, but recently nonlinear effects have become more important, even in low-intensity diagnostic applications.

  17. Acoustic chaos

    SciTech Connect

    Lauterborn, W.; Parlitz, U.; Holzfuss, J.; Billo, A.; Akhatov, I.

    1996-06-01

    Acoustic cavitation, a complex, spatio-temporal dynamical system, is investigated with respect to its chaotic properties. The sound output, the {open_quote}{open_quote}noise{close_quote}{close_quote}, is subjected to time series analysis. The spatial dynamics of the bubble filaments is captured by high speed holographic cinematography and subsequent digital picture processing from the holograms. Theoretical models are put forward for describing the pattern formation. {copyright} {ital 1996 American Institute of Physics.}

  18. Administration of NaHS Attenuates Footshock-Induced Pathologies and Emotional and Cognitive Dysfunction in Triple Transgenic Alzheimer's Mice.

    PubMed

    Huang, Hei-Jen; Chen, Shu-Ling; Hsieh-Li, Hsiu Mei

    2015-01-01

    Alzheimer's disease (AD) is characterized by progressive cognitive decline and neuropsychiatric symptoms. Increasing evidence indicates that environmental risk factors in young adults may accelerate cognitive loss in AD and that Hydrogen Sulfide (H2S) may represent an innovative treatment to slow the progression of AD. Therefore, the aim of this study was to evaluate the effects of NaHS, an H2S donor, in a triple transgenic AD mouse model (3×Tg-AD) under footshock with situational reminders (SRs). Inescapable footshock with SRs induced anxiety and cognitive dysfunction as well as a decrease in the levels of plasma H2S and GSH and an increase in IL-6 levels in 3×Tg-AD mice. Under footshock with SR stimulus, amyloid deposition, tau protein hyperphosphorylation, and microgliosis were highly increased in the stress-responsive brain structures, including the hippocampus and amygdala, of the AD mice. Oxidative stress, inflammatory response, and β-site APP cleaving enzyme 1 (BACE1) levels were also increased, and the level of inactivated glycogen synthase kinase-3β (GSK3β) (pSer9) was decreased in the hippocampi of AD mice subjected to footshock with SRs. Furthermore, the numbers of cholinergic neurons in the medial septum/diagonal band of Broca (MS/DB) and noradrenergic neurons in the locus coeruleus (LC) were also decreased in the 3×Tg-AD mice under footshock with SRs. These biochemical hallmarks and pathological presentations were all alleviated by the semi-acute administration of NaHS in the AD mice. Together, these findings suggest that footshock with SRs induces the impairment of spatial cognition and emotion, which involve pathological changes in the peripheral and central systems, including the hippocampus, MS/DB, LC, and BLA, and that the administration of NaHS may be a candidate strategy to ameliorate the progression of neurodegeneration. PMID:26635562

  19. Increased vacuolar Na(+)/H(+) exchange activity in Salicornia bigelovii Torr. in response to NaCl.

    PubMed

    Parks, Graham E; Dietrich, Margaret A; Schumaker, Karen S

    2002-05-01

    Shoots of the halophyte Salicornia bigelovii are larger and more succulent when grown in highly saline environments. This increased growth and water uptake has been correlated with a large and specific cellular accumulation of sodium. In glycophytes, sensitivity to salt has been associated with an inability to remove sodium ions effectively from the cytoplasm in order to protect salt-sensitive metabolic processes. Therefore, in Salicornia bigelovii efficient vacuolar sequestration of sodium may be part of the mechanism underlying salt tolerance. The ability to compartmentalize sodium may result from a stimulation of the proton pumps that provide the driving force for increased sodium transport into the vacuole via a Na(+)/H(+) exchanger. In current studies, increased vacuolar pyrophosphatase activity (hydrolysis of inorganic pyrophosphate and proton translocation) and protein accumulation were observed in Salicornia bigelovii grown in high concentrations of NaCl. Based on sodium-induced dissipation of a pyrophosphate-dependent pH gradient in vacuolar membrane vesicles, a Na(+)/H(+) exchange activity was identified and characterized. This activity is sodium concentration-dependent, specific for sodium and lithium, sensitive to methyl-isobutyl amiloride, and independent of an electrical potential. Vacuolar Na(+)/H(+) exchange activity varied as a function of plant growth in salt. The affinity of the transporter for Na(+) is almost three times higher in plants grown in high levels of salt (K(m)=3.8 and 11.5 mM for plants grown in high and low salt, respectively) suggesting a role for exchange activity in the salt adaptation of Salicornia bigelovii. PMID:11971917

  20. Role of Na+-H+ and Na+-Ca2+ exchange in hypoxia-related acute astrocyte death.

    PubMed

    Bondarenko, Alexander; Svichar, Nataliya; Chesler, Mitchell

    2005-01-01

    Cultured astrocytes do not succumb to hypoxia/zero glucose for up to 24 h, yet astrocyte death following injury can occur within 1 h. It was previously demonstrated that astrocyte loss can occur quickly when the gaseous and interstitial ionic changes of transient brain ischemia are simulated: After a 20-40-min exposure to hypoxic, acidic, ion-shifted Ringer (HAIR), most cells died within 30 min after return to normal saline (i.e., "reperfusion"). Astrocyte death required external Ca2+ and was blocked by KB-R7943, an inhibitor of reversed Na+-Ca2+ exchange, suggesting that injury was triggered by a rise in [Ca2+]i. In the present study, we confirmed the elevation of [Ca2+]i during reperfusion and studied the role of Na+-Ca2+ and Na+-H+ exchange in this process. Upon reperfusion, elevation of [Ca2+]i was detectable by Fura-2 and was blocked by KB-R7943. The low-affinity Ca2+ indicator Fura-FF indicated a mean [Ca2+]i rise to 4.8+/-0.4 microM. Loading astrocytes with Fura-2 provided significant protection from injury, presumably due to the high affinity of the dye for Ca2+. Injury was prevented by the Na+-H+ exchange inhibitors ethyl isopropyl amiloride or HOE-694, and the rise of [Ca2+]i at the onset of reperfusion was blocked by HOE-694. Acidic reperfusion media was also protective. These data are consistent with Na+ loading via Na+-H+ exchange, fostering reversal of Na+-Ca2+ exchange and cytotoxic elevation of [Ca2+]i. The results indicate that mechanisms involved in pH regulation may play a role in the fate of astrocytes following acute CNS injuries. PMID:15390092

  1. Squalamine, a novel cationic steroid, specifically inhibits the brush-border Na+/H+ exchanger isoform NHE3.

    PubMed

    Akhter, S; Nath, S K; Tse, C M; Williams, J; Zasloff, M; Donowitz, M

    1999-01-01

    Squalamine, an endogenous molecule found in the liver and other tissues of Squalus acanthias, has antibiotic properties and causes changes in endothelial cell shape. The latter suggested that its potential targets might include transport proteins that control cell volume or cell shape. The effect of purified squalamine was examined on cloned Na+/H+ exchanger isoforms NHE1, NHE2, and NHE3 stably transfected in PS120 fibroblasts. Squalamine (1-h pretreatment) decreased the maximal velocity of rabbit NHE3 in a concentration-dependent manner (13, 47, and 57% inhibition with 3, 5, and 7 micrograms/ml, respectively) and also increased K'[H+]i. Squalamine did not affect rabbit NHE1 or NHE2 function. The inhibitory effect of squalamine was 1) time dependent, with no effect of immediate addition and maximum effect with 1 h of exposure, and 2) fully reversible. Squalamine pretreatment of the ileum for 60 min inhibited brush-border membrane vesicle Na+/H+ activity by 51%. Further investigation into the mechanism of squalamine's effects showed that squalamine required the COOH-terminal 76 amino acids of NHE3. Squalamine had no cytotoxic effect at the concentrations studied, as indicated by monitoring lactate dehydrogenase release. These results indicate that squalamine 1) is a specific inhibitor of the brush-border NHE isoform NHE3 and not NHE1 or NHE2, 2) acts in a nontoxic and fully reversible manner, and 3) has a delayed effect, indicating that it may influence brush-border Na+/H+ exchanger function indirectly, through an intracellular signaling pathway or by acting as an intracellular modulator. PMID:9886929

  2. The temperature dependence of intracellular pH in isolated frog skeletal muscle: lessons concerning the Na(+)-H+ exchanger.

    PubMed

    Marjanovic, M; Elliott, A C; Dawson, M J

    1998-02-01

    We used 31P NMR to investigate the temperature-dependence of intracellular pH (pHi) in isolated frog skeletal muscles. We found that Ln[H+i] is a linear function of 1/Tabs paralleling those of neutral water (i.e., H+ = OH-) and of a solution containing the fixed pH buffers of frog muscle cytosol. This classical van't Hoff relationship was unaffected by inhibition of glycolysis and was not dependent upon the pH or [Na+] in the bathing solution. Insulin stimulation of Na(+)-H+ exchange shifted the intercept in the alkaline direction but had not effect on the slope. Acid loading followed by washout resulted in an amiloride-sensitive return to the (temperature dependent) basal pHi. These results show that the temperature dependence of activation of Na(+)-H+ exchange is similar to that of the intracellular buffers, and suggest that constancy of [H+]/ [OH-] with changing temperature is achieved in the short term by intracellular buffering and in the long term by the set-point of the Na(+)-H+ exchanger. Proton activation of the exchanger has an apparent standard enthalpy change (delta H degree) under both control and insulin-stimulated conditions that is similar to the delta H degree of the intracellular buffers and approximately half of the delta H degree for the dissociation of water. Thus, the temperature-dependent component of the standard free-energy change (delta F degree) is unaffected by insulin stimulation, suggesting that changes in Arrhenius activation energy (Ea) may not be a part of the mechanism of hormone stimulation. PMID:9493127

  3. Interaction potentials of LiH, NaH, KH, RbH, and CsH

    NASA Astrophysics Data System (ADS)

    Geum, N.; Jeung, G.-H.; Derevianko, A.; Côté, R.; Dalgarno, A.

    2001-10-01

    Quantum-mechanical calculations of the potential energy curves of the singlet and triplet states of LiH, NaH, KH, RbH, and CsH formed by the approach of ground state alkali-metal atoms and hydrogen atoms are presented. Precise values are determined for the coefficients of the van der Waals interaction and estimates are made of the contribution of the exchange interaction at large distances. Together with empirical data, they are used to assess and improve the accuracy of the ab initio potentials.

  4. Modification of intracellular calcium concentration in cardiomyocytes by inhibition of sarcolemmal Na+/H+ exchanger.

    PubMed

    Saini, Harjot K; Dhalla, Naranjan S

    2006-12-01

    Although the Na(+)/H(+) exchanger (NHE) is considered to be involved in regulation of intracellular Ca(2+) concentration ([Ca(2+)](i)) through the Na(+)/Ca(2+) exchanger, the exact mechanisms of its participation in Ca(2+) handling by cardiomyocytes are not fully understood. Isolated rat cardiomyocytes were treated with or without agents that are known to modify Ca(2+) movements in cardiomyocytes and exposed to an NHE inhibitor, 5-(N-methyl-N-isobutyl)amiloride (MIA). [Ca(2+)](i) in cardiomyocytes was measured spectrofluorometrically with fura 2-AM in the absence or presence of KCl, a depolarizing agent. MIA increased basal [Ca(2+)](i) and augmented the KCl-induced increase in [Ca(2+)](i) in a concentration-dependent manner. The MIA-induced increase in basal [Ca(2+)](i) was unaffected by extracellular Ca(2+), antagonists of the sarcolemmal (SL) L-type Ca(2+) channel, and inhibitors of the SL Na(+)/Ca(2+) exchanger, SL Ca(2+) pump ATPase and mitochondrial Ca(2+) uptake. However, the MIA-induced increase in basal [Ca(2+)](i) was attenuated by inhibitors of SL Na(+)-K(+)-ATPase and sarcoplasmic reticulum (SR) Ca(2+) transport. On the other hand, the MIA-mediated augmentation of the KCl response was dependent on extracellular Ca(2+) concentration and attenuated by agents that inhibit SL L-type Ca(2+) channels, the SL Na(+)/Ca(2+) exchanger, SL Na(+)-K(+)-ATPase, and SR Ca(2+) release channels and the SR Ca(2+) pump. However, the effect of MIA on the KCl-induced increase in [Ca(2+)](i) remained unaffected by treatment with inhibitors of SL Ca(2+) pump ATPase and mitochondrial Ca(2+) uptake. MIA and a decrease in extracellular pH lowered intracellular pH and increased basal [Ca(2+)](i), whereas a decrease in extracellular pH, in contrast to MIA, depressed the KCl-induced increase in [Ca(2+)](i) in cardiomyocytes. These results suggest that NHE may be involved in regulation of [Ca(2+)](i) and that MIA-induced increases in basal [Ca(2+)](i), as well as augmentation of the

  5. Azilsartan Improves Salt Sensitivity by Modulating the Proximal Tubular Na+-H+ Exchanger-3 in Mice

    PubMed Central

    Hatanaka, Masaki; Kaimori, Jun-Ya; Yamamoto, Satoko; Matsui, Isao; Hamano, Takayuki; Takabatake, Yoshitsugu; Ecelbarger, Carolyn M.; Takahara, Shiro; Isaka, Yoshitaka; Rakugi, Hiromi

    2016-01-01

    A potent angiotensin II type-1 receptor blocker, azilsartan, has been reported to reduce blood pressure more effectively than candesartan. Interestingly, azilsartan can also restore the circadian rhythm of blood pressure. We hypothesized that azilsartan could also improve salt sensitivity; thus, we examined the effect of azilsartan on sodium handling in renal tubules. Subtotal nephrectomized C57BL/6 mice received azilsartan (1.0 mg/kg/day), candesartan (0.3 mg/kg/day), or vehicle via the oral route in conjunction with a normal- (0.3%) or high-salt (8.0%) diet. Two weeks later, the azilsartan group showed significantly lower blood pressure during the light period than the candesartan and vehicle groups (azilsartan: 103.1 ± 1.0; candesartan: 111.7 ± 2.7; vehicle: 125.5 ± 2.5 mmHg; P < 0.05; azilsartan or candesartan vs. vehicle). The azilsartan group also showed higher urinary fractional excretion of sodium during the dark period than the candesartan and vehicle groups (azilsartan: 21.37 ± 3.69%; candesartan: 14.17 ± 1.42%; vehicle: 13.85 ± 5.30%; P < 0.05 azilsartan vs. candesartan or vehicle). A pressure—natriuresis curve demonstrated that azilsartan treatment restored salt sensitivity. Immunofluorescence and western blotting showed lower levels of Na+-H+ exchanger-3 (NHE3) protein (the major sodium transporter in renal proximal tubules) in the azilsartan group, but not in the candesartan or vehicle groups. However, azilsartan did not affect NHE3 transcription levels. Interestingly, we did not observe increased expression of downstream sodium transporters, which would have compensated for the increased flow of sodium and water due to non-absorption by NHE3. We also confirmed the mechanism stated above using cultured opossum kidney proximal tubular cells. Results revealed that a proteasomal inhibitor (but not a lysosomal inhibitor) blocked the azilsartan-induced decrease in NHE3 protein expression, suggesting that azilsartan increases NHE3 ubiquitination. In

  6. Azilsartan Improves Salt Sensitivity by Modulating the Proximal Tubular Na+-H+ Exchanger-3 in Mice.

    PubMed

    Hatanaka, Masaki; Kaimori, Jun-Ya; Yamamoto, Satoko; Matsui, Isao; Hamano, Takayuki; Takabatake, Yoshitsugu; Ecelbarger, Carolyn M; Takahara, Shiro; Isaka, Yoshitaka; Rakugi, Hiromi

    2016-01-01

    A potent angiotensin II type-1 receptor blocker, azilsartan, has been reported to reduce blood pressure more effectively than candesartan. Interestingly, azilsartan can also restore the circadian rhythm of blood pressure. We hypothesized that azilsartan could also improve salt sensitivity; thus, we examined the effect of azilsartan on sodium handling in renal tubules. Subtotal nephrectomized C57BL/6 mice received azilsartan (1.0 mg/kg/day), candesartan (0.3 mg/kg/day), or vehicle via the oral route in conjunction with a normal- (0.3%) or high-salt (8.0%) diet. Two weeks later, the azilsartan group showed significantly lower blood pressure during the light period than the candesartan and vehicle groups (azilsartan: 103.1 ± 1.0; candesartan: 111.7 ± 2.7; vehicle: 125.5 ± 2.5 mmHg; P < 0.05; azilsartan or candesartan vs. vehicle). The azilsartan group also showed higher urinary fractional excretion of sodium during the dark period than the candesartan and vehicle groups (azilsartan: 21.37 ± 3.69%; candesartan: 14.17 ± 1.42%; vehicle: 13.85 ± 5.30%; P < 0.05 azilsartan vs. candesartan or vehicle). A pressure-natriuresis curve demonstrated that azilsartan treatment restored salt sensitivity. Immunofluorescence and western blotting showed lower levels of Na+-H+ exchanger-3 (NHE3) protein (the major sodium transporter in renal proximal tubules) in the azilsartan group, but not in the candesartan or vehicle groups. However, azilsartan did not affect NHE3 transcription levels. Interestingly, we did not observe increased expression of downstream sodium transporters, which would have compensated for the increased flow of sodium and water due to non-absorption by NHE3. We also confirmed the mechanism stated above using cultured opossum kidney proximal tubular cells. Results revealed that a proteasomal inhibitor (but not a lysosomal inhibitor) blocked the azilsartan-induced decrease in NHE3 protein expression, suggesting that azilsartan increases NHE3 ubiquitination. In

  7. Hydrogen sulfide from a NaHS source attenuates dextran sulfate sodium (DSS)-induced inflammation via inhibiting nuclear factor-κB

    PubMed Central

    Chen, Xi; Liu, Xi-shuang

    2016-01-01

    This study investigated the alleviating effects of hydrogen sulfide (H2S), derived from sodium hydrosulfide (NaHS), on inflammation induced by dextran sulfate sodium (DSS) in both in vivo and in vitro models. We found that NaHS injection markedly decreased rectal bleeding, diarrhea, and histological injury in DSS-challenged mice. NaHS (20 μmol/L) reversed DSS-induced inhibition in cell viability in Caco-2 cells and alleviated pro-inflammation cytokine expression in vivo and in vitro, indicating an anti-inflammatory function for H2S. It was also found that H2S may regulate cytokine expression by inhibiting the nuclear factor-κB (NF-κB) signaling pathway. In conclusion, our results demonstrated that H2S alleviated DSS-induced inflammation in vivo and in vitro and that the signal mechanism might be associated with the NF-κB signaling pathway. PMID:26984841

  8. Acoustic Tooth Cleaner

    NASA Technical Reports Server (NTRS)

    Heyman, J. S.

    1984-01-01

    Acoustically-energized water jet aids in plaque breakdown. Acoustic Wand includes acoustic transducer 1/4 wave plate, and tapered cone. Together elements energize solution of water containing mild abrasive injected into mouth to help prevent calculous buildup.

  9. Defect detection of wall paintings in the Château de Versailles using TV-holography and IR thermography

    NASA Astrophysics Data System (ADS)

    Chambard, Jean-Pierre; Roche, Alain

    2007-07-01

    Monuments are continuously submitted to external events like water infiltration or condensation, temperature variation, soil instability, that lead to internal damage of the structure itself as well as of its surfaces. Wall paintings are then submitted to stresses that may cause cracks, internal de-lamination of the plaster or de-bonding between canvas and plaster. In the frame of the restoration of the "galerie des glaces" in the "château de Versailles", TV-Holography and IR Thermography have been used to investigate the wall paintings of the vault. The surfaces to control were either direct paintings on the plaster or paintings on canvas backed on the plaster. IR Thermography for art work and in particular for wall paintings has only recently been used. The technique allows to record transient temperature maps, when slightly heating the surface during a short time. Then, nonhomogeneities in the conductive heat transfer are related to de-bonding or de-lamination. The time parameter gives information on the depth of the defect. A calibration procedure has to be carried out to ensure reliable defect detection. Speckle interferometry is a Non Destructive Testing technique that is currently used in industry. For the wall paintings, we have used TV-Holography associated with a continuous wave laser. The technique allows, 13 metres away from the surface, to detect parts of the paintings that were vibrating due to an acoustic excitation. The control processes based on these two technologies is detailed as well as the results obtained and a comparison with manual investigation is done.

  10. "Best Match" Model and Effect of Na+/H+ Exchange on Anion Attachment to Peptides and Stability of Formed Adducts in Negative Ion Electrospray Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Liu, Xiaohua; Cole, Richard B.

    2013-12-01

    The "Best Match" model has been extended to account for the role that Na+/H+ exchange plays on anion attachment in negative ion electrospray. Without any Na+/H+ exchange on (Glu) fibrinopeptide B, the higher basicity anions F- and CH3COO- can hardly form observable adducts; however, after multiple Na+/H+ exchanges, adduct formation is enabled. Moreover, dissociation pathways of CF3COO- adducts with singly deprotonated peptides that have undergone 0 to 3 Na+/H+ exchanges exhibit a shift in CID product ions from losing predominately CF3COOH (case of 0 Na+/H+ exchanges) to losing predominately CF3COO- (case of 3 Na+/H+ exchanges). These phenomena can be rationalized by considering that Na+ cations exchange at, and serve to "block", the most acidic sites, thereby forcing implicated anions to attach to lower acidity protons. In addition to forming ion pairs with carboxylate groups, Na+ also participates in formation of tri-atomic ions of the form ANaA- during adduct dissociation. The fact that low gas-phase basicity (GB) anions preferentially form ANaA- species, even though high GB anions form more stable tri-atomic species, indicates that the monatomic ions were not in close contact in the initial adduct. The propensity for formation of stable anionic adducts is dependent on the degree of matching between anion GBs and GBapp of deprotonated sites on the peptide. The GBapp is raised dramatically as the charge state of the peptide increases via a through-space effect. The presence of Na+ on carboxylate sites substantially decreases the GBapp by neutralizing these sites, while slightly increasing the intrinsic GBs by an inductive effect.

  11. Development and polarization of the Na+/H+ antiport system during reorganization of LLC-PK1A cells into an epithelial membrane.

    PubMed

    Viniegra, S; Rabito, C A

    1988-05-25

    Changes in Na+/H+ antiport activity and transepithelial electrical resistance were analyzed in a clone of LLC-PK1 cells as the dispersed cells became organized into an epithelial membrane. The clone designated LLC-PK1A showed a 250% increase in Na+/H+ exchange activity as compared with the parent cell line. Na+ influx induced by an outwardly oriented H+ gradient is almost completely abolished during active cell proliferation or after cell dispersion. The activity of the Na+/H+ antiport system increases after plating the cells at high density. This increase precedes the increase in the transepithelial electrical resistance. The increase in the Na+/H+ antiport activity was not observed when the cells were plated at low density in the presence of an antimitotic agent indicating that close cell contact is an absolute requirement for the development of the system. The increase in Na+ influx correlated with an increase in Vmax, while the Km for Na+ remained essentially unchanged. Unidirectional Na+ influx measured from the apical or basolateral side as the dispersed cells became reorganized into an epithelial membrane indicated that the insertion of the Na+/H+ antiporter proteins occurred directly in the apical membrane of the epithelial cells. This finding is consistent with the hypothesis that the sorting of native proteins occurs intracellularly prior to their insertion in the apical membrane of the epithelial cells. The delay in the increase of transepithelial electrical resistance as compared with the increase in Na+ influx indicates that the settlement of the limits between the apical and basolateral membrane (fence function) precedes the closing of the intercellular space (barrier function) during the development of the occluding junctions. Further, the development of the Na+/H+ antiporter was inhibited by cycloheximide but not by actinomycin D, suggesting that the expression of epithelial cell polarization is a translational or posttranslational event. PMID

  12. Gene amplification at a locus encoding a putative Na+/H+ antiporter confers sodium and lithium tolerance in fission yeast.

    PubMed Central

    Jia, Z P; McCullough, N; Martel, R; Hemmingsen, S; Young, P G

    1992-01-01

    We have identified a new locus, sodium 2 (sod2) based on selection for increased LiCl tolerance in fission yeast, Schizosaccharomyces pombe. Tolerant strains have enhanced pH-dependent Na+ export capacity and sodium transport experiments suggest that the gene encodes an Na+/H+ antiport. The predicted sod2 gene product can be placed in the broad class of transporters which possess 12 hydrophobic transmembrane domains. The protein shows some sequence similarity to the human and bacterial Na+/H+ antiporters. Overexpression of sod2 increased Na+ export capacity and conferred sodium tolerance. Osmotolerance was not affected and sod2 cells were unaffected for growth in K+. In a sod2 disruption strain cells were incapable of exporting sodium. They were hypersensitive to Na+ or Li+ and could not grow under conditions that approximate pH7. The sod2 gene amplification could be selected stepwise and the degree of such amplification correlated with the level of Na+ or Li+ tolerance. Images PMID:1314171

  13. Acoustic transducer

    DOEpatents

    Drumheller, D.S.

    1997-12-30

    An acoustic transducer is described comprising a one-piece hollow mandrel into the outer surface of which is formed a recess with sides perpendicular to the central axis of the mandrel and separated by a first distance and with a bottom parallel to the central axis and within which recess are a plurality of washer-shaped discs of a piezoelectric material and at least one disc of a temperature-compensating material with the discs being captured between the sides of the recess in a pre-stressed interference fit, typically at 2,000 psi of compressive stress. The transducer also includes a power supply and means to connect to a measurement device. The transducer is intended to be used for telemetry between a measurement device located downhole in an oil or gas well and the surface. The transducer is of an construction that is stronger with fewer joints that could leak fluids into the recess holding the piezoelectric elements than is found in previous acoustic transducers. 4 figs.

  14. Acoustic transducer

    DOEpatents

    Drumheller, Douglas S.

    1997-01-01

    An acoustic transducer comprising a one-piece hollow mandrel into the outer surface of which is formed a recess with sides perpendicular to the central axis of the mandrel and separated by a first distance and with a bottom parallel to the central axis and within which recess are a plurality of washer-shaped discs of a piezoelectric material and at least one disc of a temperature-compensating material with the discs being captured between the sides of the recess in a pre-stressed interference fit, typically at 2000 psi of compressive stress. The transducer also includes a power supply and means to connect to a measurement device. The transducer is intended to be used for telemetry between a measurement device located downhole in an oil or gas well and the surface. The transducer is of an construction that is stronger with fewer joints that could leak fluids into the recess holding the piezoelectric elements than is found in previous acoustic transducers.

  15. In-line digital holography with double knife edge

    NASA Astrophysics Data System (ADS)

    Ramirez, Claudio; Iemmi, Claudio; Campos, Juan

    2015-06-01

    We study and test a new technique for in-line digital holography which avoids the formation of the conjugate images. Inline digital holography is based in a common path configuration. In this case, the hologram is produced by the interference between the reference wave front and the diffracted wave front by an almost transparent object. Twin images are obtained with obscured rings that difficult the determination of the best focusing plane. To avoid the conjugated image, the information of the magnitude and phase of the wave front are needed. In a recent work a new in-line digital holography technique was proposed. In this method the object is illuminated with a collimated wave front. A plane, close to the particles distribution is imaged onto a CCD by means of a convergent lens and at the same time, a knife edge is placed in the focal plane of the lens in order to block half of spatial frequency spectrum. In this way, by means of a numerical processing performed on the Fourier plane, it is possible to eliminate one of the components (real or conjugate) of the reconstructed images nevertheless it is observed a tiny deformation of the resulting hologram image. To compensate this effect, we propose a new configuration in which we implement the knife edge technique on both parts of the spectrum at the same time. Finally in the computer, we process the holograms to build one complete without deformation. This hologram is used to recover the wave front at different planes without the influence of the conjugate image.

  16. Interactions of external and internal H+ and Na+ with Na+/Na+ and Na+/H+ exchange of rabbit red cells: evidence for a common pathway.

    PubMed

    Morgan, K; Canessa, M

    1990-12-01

    We have studied the kinetic properties of rabbit red cell (RRBC) Na+/Na+ and Na+/H+ exchanges (EXC) in order to define whether or not both transport functions are conducted by the same molecule. The strategy has been to determine the interactions of Na+ and H+ at the internal (i) and external (o) sites for both exchanges modes. RRBC containing varying Nai and Hi were prepared by nystatin and DIDS treatment of acid-loaded cells. Na+/Na+ EXC was measured as Nao-stimulated Na+ efflux and Na+/H+ EXC as Nao-stimulated H+ efflux and delta pHo-stimulated Na+ influx into acid-loaded cells. The activation of Na+/Na+ EXC by Nao at pHi 7.4 did not follow simple hyperbolic kinetics. Testing of different kinetic models to obtain the best fit for the experimental data indicated the presence of high (Km 2.2 mM) and low affinity (Km 108 mM) sites for a single- or two-carrier system. The activation of Na+/H+ EXC by Nao (pHi 6.6, Nai less than 1 mM) also showed high (Km 11 mM) and low (Km 248 mM) affinity sites. External H+ competitively inhibited Na+/Na+ EXC at the low affinity Nao site (KH 52 nM) while internally H+ were competitive inhibitors (pK 6.7) at low Nai and allosteric activators (pK 7.0) at high Nai. Na+/H+ EXC was also inhibited by acid pHo and allosterically activated by Hi (pK 6.4). We also established the presence of a Nai regulatory site which activates Na+/H+ and Na+/Na+ EXC modifying the affinity for Nao of both pathways. At low Nai, Na+/Na+ EXC was inhibited by acid pHi and Na+/H+ stimulated but at high Nai, Na+/Na+ EXC was stimulated and Na+/H+ inhibited being the sum of both pathways kept constant. Both exchange modes were activated by two classes of Nao sites, cis-inhibited by external Ho, allosterically modified by the binding of H+ to a Hi regulatory site and regulated by Nai. These findings are consistent with Na+/Na+ EXC being a mode of operation of the Na+/H+ exchanger. Na+/H+ EXC was partially inhibited (80-100%) by dimethyl-amiloride (DMA) but basal or

  17. Biomechanical testing in experimental surgery by laser holography

    NASA Astrophysics Data System (ADS)

    Podbielska, Halina; Kasprzak, Henryk T.; Pennig, Dietmar

    1990-06-01

    Of all the capabilities of holography for image processing and measuring purposes, holographic interferometry has found the broadest application in biological and medical research. As a technique, which is non-destructive and allows for high resolving deformation analysis, holographic interferometry has gained popularity over the recent years in experimental biomechanics and orthopaedics. Some examples of holographic interferometry in experimental orthopaedics are reviewed in this report. The possibility of using holographic interferometry to study the behaviour of broken bones supported by fixing devices is pointed out in this review.

  18. Soft x-ray holography and microscopy of biological cells

    NASA Astrophysics Data System (ADS)

    Chen, Jianwen; Gao, Hongyi; Xie, Honglan; Li, Ruxin; Xu, Zhizhan

    2003-10-01

    Some experimental results on soft X-ray microscopy and holography imaging of biological specimens are presented in the paper. As we know, due to diffraction effects, there exists a resolution limit determined by wavelength λ and numerical aperture NA in conventional optical microscopy. In order to improve resolution, the num erical aperture should be made as large as possible and the wavelength as short as possible. Owing to the shorter wavelength, X-rays provide the potential of higher resolution in X-ray microscopy, holography image and allow for exam ination the interior structures of thicker specimens. In the experiments, we used synchrotron radiation source in Hefei as light source. Soft X-rays come from a bending magnet in 800 M eV electron storage ring with characteristic wavelength of 2.4 nm. The continuous X-ray spectrums are monochromatized by a zone-plate and a pinhole with 300 m diameter. The experimental set-up is typical contact microscopic system, its main advantage is simplicity and no special optical element is needed. The specimens used in the experiments of microscopic imaging are the colibacillus, the gingko vascular hundle and the fritillaries ovary karyon. The specimen for holographic imaging is the spider filam ents. The basic structures of plant cells such as the cell walls, the cytoplasm and the karyon especially the joint structures between the cells are observed clearly. An experimental study on a thick biological specimen that is a whole sporule w ith the thickness of about 30 μm is performed. In the holographic experiments, the experimental setup is typical Gabor in-line holography. The specimen is placed in line with X-ray source, which provides both the reference w aves and specimen illum ination. The specimen is some spider filament, which adhere to a Si3N4 film. The recording medium is PM M A, which is placed at recording distance of about 400 μm from the specimen. The hologram s were reconstructed by digital method with 300 nm

  19. Experimental characterization of solid propellants combustion by digital holography

    NASA Astrophysics Data System (ADS)

    Chen, Jun; Powell, Michael; Gao, Jian; Gunduz, Ibrahim; Guildenbecher, Daniel; Son, Steve

    2014-11-01

    Aluminum and other additions are widely used in solid propellants to improve performance. In this study, we apply digital holography as a three-dimensional diagnostic tool to characterize the burning of composite solid propellants with addition of different composite particles. Structures around the burning surfaces and reaction zones are identified, whereas the drop morphologies and their size/velocity distributions are quantified. The nano-second exposure of this imaging technique enables time-freezing measurements of the highly dynamic combustion process. The results are compared with discoveries from high-speed imaging. This technique is also applied to study the combustions of solid propellants under high-pressure environment.

  20. Characterization of Magnetic Nanostructures Using Off-Axis Electron Holography

    NASA Astrophysics Data System (ADS)

    Zhang, Desai

    This dissertation research has involved microscopic characterization of magnetic nanostructures using off-axis electron holography and Lorentz microscopy. The nanostructures investigated have included Co nanoparticles (NPs), Au/Fe/GaAs shell/core nanowires (NWs), carbon spirals with magnetic cores, magnetic nanopillars, Ni-Zn-Co spinel ferrite and CoFe/Pd multilayers. The studies have confirmed the capability of holography to describe the behavior of magnetic structures at the nanoscale. The phase changes caused by the fringing fields of chains consisting of Co NPs were measured and calculated. The difference between chains with different numbers of Co NPs followed the trend indicated by calculations. Holography studies of Au/Fe/GaAs NWs grown on (110) GaAs substrates with rotationally non-uniform coating confirmed that Fe was present in the shell and that the shell behaved as a bar magnet. No fringing field was observed from NWs with cylindrical coating grown on (111)B GaAs substrates. The most likely explanation is that magnetic fields are confined within the shells and form closed loops. The multiple-magnetic-domain structure of iron carbide cores in carbon spirals was imaged using phase maps of the fringing fields. The strength and range of this fringing field was insufficient for manipulating the carbon spirals with an external applied magnetic field. No magnetism was revealed for CoPd/Fe/CoPd magnetic nanopillars. Degaussing and MFM scans ruled out the possibility that saturated magnetization and sample preparation had degraded the anisotropy, and the magnetism, respectively. The results suggested that these nanopillars were not suitable as candidates for prototypical bit information storage devices. Observations of Ni-Zn-Co spinel ferrite thin films in plan-view geometry indicated a multigrain magnetic domain structure and the magnetic fields were oriented in-plane only with no preferred magnetization distribution. This domain structure helps explain this

  1. Beamforming and holography image formation methods: an analytic study.

    PubMed

    Solimene, Raffaele; Cuccaro, Antonio; Ruvio, Giuseppe; Tapia, Daniel Flores; O'Halloran, Martin

    2016-04-18

    Beamforming and holographic imaging procedures are widely used in many applications such as radar sensing, sonar, and in the area of microwave medical imaging. Nevertheless, an analytical comparison of the methods has not been done. In this paper, the Point Spread Functions pertaining to the two methods are analytically determined. This allows a formal comparison of the two techniques, and to easily highlight how the performance depends on the configuration parameters, including frequency range, number of scatterers, and data discretization. It is demonstrated that the beamforming and holography basically achieve the same resolution but beamforming requires a cheaper (less sensors) configuration.. PMID:27137336

  2. Holography and the control of self-propelled vehicles

    NASA Technical Reports Server (NTRS)

    Yeroshin, V. I.; Novikov, G. P.; Busargin, V. M.; Kurmanaliyev, T. I.

    1974-01-01

    The possibility of applying the principles of holography and optical data processing in the control of self-propelled space vehicles is considered. Various methods of controlling space vehicles are described: (1) by the results of comparing the image with the standard hologram; (2) by holographic images transmitted over moon earth communications channels; and (3) on the basis of using autotelevision cameras with a three dimensional screen. Procedures are presented for obtaining the standard holograms. The structural organization of the microprogrammed automaton controlling the movement of the space vehicle is also presented.

  3. Direct inversion of digital 3D Fraunhofer holography maps.

    PubMed

    Podorov, Sergei G; Förster, Eckhart

    2016-01-20

    Differential Fourier holography (DFH) gives an exact mathematical solution of the inverse problem of diffraction in the Fraunhofer regime. After the first publication [Opt. Express15, 9954 (2007)], DFH was successfully applied in many experiments to obtain amplitude and phase information about two-dimensional images. In this paper, we demonstrate numerically the possibility to apply DFH also for investigation of unknown three-dimensional objects. The first simulation is made for a double-spiral structure plus a line as a reference object. PMID:26835947

  4. Image/video encryption using single shot digital holography

    NASA Astrophysics Data System (ADS)

    Li, Xiaoyu; Tang, Chen; Zhu, Xinjun; Li, Biyuan; Wang, Linlin; Yan, Xiusheng

    2015-05-01

    We propose a method for image/video encryption that combines double random-phase encoding in the Fresnel domain with a single shot digital holography. In this method, a complex object field can be reconstructed with only single frame hologram based on a constrained optimization method. The system without multiple shots and Fourier lens is simple, and allows to dynamically encrypt information. We test the proposed method on a computer simulated image, a grayscale image and a video in AVI format. Also we investigate the quality of the decryption process and the performance against noise attacks. The experimental results demonstrate the performance of the method.

  5. Digital holography applications in ophthalmology, biometry, and optical trapping characterization

    NASA Astrophysics Data System (ADS)

    Potcoava, Mariana Camelia

    This dissertation combines various holographic techniques with application on the two- and three-dimensional imaging of ophthalmic tissue, fingerprints, and microsphere samples with micrometer resolution. Digital interference holography (DIH) uses scanned wavelengths to synthesize short-coherence interference tomographic images. We used DIH for in vitro imaging of human optic nerve head and retina. Tomographic images were produced by superposition of holograms. Holograms were obtained with a signal-to-noise ratio of approximately 50 dB. Optic nerve head characteristics (shape, diameter, cup depth, and cup width) were quantified with a few micron resolution (4.06--4.8mum). Multiple layers were distinguishable in cross-sectional images of the macula. To our knowledge, this is the first report of DIH use to image human macular and optic nerve tissue. Holographic phase microscopy is used to produce images of thin film patterns left by latent fingerprints. Two or more holographic phase images with different wavelengths are combined for optical phase unwrapping of images of patent prints. We demonstrated digital interference holography images of a plastic print, and latent prints. These demonstrations point to significant contributions to biometry by using digital interference holography to identify and quantify Level 1 (pattern), Level 2 (minutia points), and Level 3 (pores and ridge contours). Quantitative studies of physical and biological processes and precise non-contact manipulation of nanometer/micrometer trapped objects can be effectuated with nanometer accuracy due to the development of optical tweezers. A three-dimensional gradient trap is produced at the focus position of a high NA microscope objective. Particles are trapped axially and laterally due to the gradient force. The particle is confined in a potential well and the trap acts as a harmonic spring. The elastic constant or the stiffness along any axis is determined from the particle displacements in

  6. The holography endstation of beamline P10 at PETRA III

    SciTech Connect

    Kalbfleisch, S.; Osterhoff, M.; Giewekemeyer, K.; Neubauer, H.; Krueger, S. P.; Hartmann, B.; Bartels, M.; Salditt, T.; Sprung, M.; Leupold, O.; Siewert, F.

    2010-06-23

    We present the design and instrumentation of a novel holography endstation for the P10 coherence beamline at PETRA III at DESY. The experimental imaging scheme is based on a highly coherent and divergent (cone) beam illumination, achieved by fixed curvature focusing mirrors with additional spatial and coherence filtering by x-ray waveguides. The optical elements along the beam path and the instrument under construction are described. Preliminary results obtained in a similar setting under comparable parameters are given as a benchmark, and first simulations of one of the two mirrors are presented to study the effect of imperfections on the field distribution in the focal plane.

  7. Analysis of clarinet reed oscillations with digital Fresnel holography

    NASA Astrophysics Data System (ADS)

    Picart, P.; Leval, J.; Piquet, F.; Boileau, J.-P.; Dalmont, J.-P.

    2009-07-01

    This paper describes optical instrumentation devoted to vibration analysis. Two strategies based on digital Fresnel holography are presented. The first, called time-averaging consists in the numerical reconstruction of the hologram after recording with an exposure time much greater than the vibration period. Thus, the holograms are amplitude modulated by a Bessel function. The last strategy, using a pulsed regime, allows the reconstruction of the full movement of the vibration, even if it exhibits very high amplitude. Experimental results presented in this paper concern the study of the vibrations of a clarinet reed under free and forced oscillation regimes.

  8. Response analysis of holography-based modal wavefront sensor.

    PubMed

    Dong, Shihao; Haist, Tobias; Osten, Wolfgang; Ruppel, Thomas; Sawodny, Oliver

    2012-03-20

    The crosstalk problem of holography-based modal wavefront sensing (HMWS) becomes more severe with increasing aberration. In this paper, crosstalk effects on the sensor response are analyzed statistically for typical aberrations due to atmospheric turbulence. For specific turbulence strength, we optimized the sensor by adjusting the detector radius and the encoded phase bias for each Zernike mode. Calibrated response curves of low-order Zernike modes were further utilized to improve the sensor accuracy. The simulation results validated our strategy. The number of iterations for obtaining a residual RMS wavefront error of 0.1λ is reduced from 18 to 3. PMID:22441478

  9. Full-field vibrometry with digital Fresnel holography

    SciTech Connect

    Leval, Julien; Picart, Pascal; Boileau, Jean Pierre; Pascal, Jean Claude

    2005-09-20

    A setup that permits full-field vibration amplitude and phase retrieval with digital Fresnel holography is presented. Full reconstruction of the vibration is achieved with a three-step stroboscopic holographic recording, and an extraction algorithm is proposed. The finite temporal width of the illuminating light is considered in an investigation of the distortion of the measured amplitude and phase. In particular, a theoretical analysis is proposed and compared with numerical simulations that show good agreement. Experimental results are presented for a loudspeaker under sinusoidal excitation; the mean quadratic velocity extracted from amplitude evaluation under two different measuring conditions is presented. Comparison with time averaging validates the full-field vibrometer.

  10. Applications of holography; Proceedings of the Meeting, Los Angeles, CA, January 21-23, 1985

    SciTech Connect

    Huff, L.

    1985-01-01

    Among the topics discussed are: holographic displays; industrial applications of holography; dual thermoplastic holography recording; holographic interferometry applied to symmetric aerodynamic models in a wind tunnel; and fringe carrier techniques for unambiguous detection of holographically recorded displacements. Attention is also given to: holographic fringe linearization interferometry (FLI) for defect detection; tunable holographic filtering in dichromated gelatin operating in the near infrared region; holographic honeycomb microlenses; and electron-beam fabrication of computer generated holograms (CGH). Among additional topics discussed are: hologram recording with a photopolymer system; white-light Fourier holography; and white light holograms for credit card applications.

  11. Deformation and 3D-shape measurement system based on phase-shifting digital holography

    NASA Astrophysics Data System (ADS)

    Lai, Songcan; Kolenovic, Ervin; Osten, Wolfgang; Jueptner, Werner P. O.

    2002-05-01

    This paper presents an endoscopic digital holographic interferometry system which is based on phase-shifting in-line digital holography. The system is able to measure both the shape and deformation of an object with the advantages of digital holography, such as real-time processing of the hologram. Two theoretical problems are briefly described: phase-shifting in- line holography and hologram data re-sampling for 2-wavelength contouring. In addition, initial experimental results of the deformation of a metal piece and surface 3D-shape measurement of a bottle cap are given.

  12. The application of holography as a real-time three-dimensional motion picture camera

    NASA Technical Reports Server (NTRS)

    Kurtz, R. L.

    1973-01-01

    A historical introduction to holography is presented, as well as a basic description of sideband holography for stationary objects. A brief theoretical development of both time-dependent and time-independent holography is also provided, along with an analytical and intuitive discussion of a unique holographic arrangement which allows the resolution of front surface detail from an object moving at high speeds. As an application of such a system, a real-time three-dimensional motion picture camera system is discussed and the results of a recent demonstration of the world's first true three-dimensional motion picture are given.

  13. Acoustic cryocooler

    DOEpatents

    Swift, Gregory W.; Martin, Richard A.; Radenbaugh, Ray

    1990-01-01

    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 effective 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 maintian a cooling load of 5 W at 80 K.

  14. Acoustic transducer

    DOEpatents

    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.

  15. Acoustic hemostasis

    NASA Astrophysics Data System (ADS)

    Crum, L.; Andrew, M.; Bailey, M.; Beach, K.; Brayman, A.; Curra, F.; Kaczkowski, P.; Kargl, S.; Martin, R.; Vaezy, S.

    2003-04-01

    Over the past several years, the Center for Industrial and Medical Ultrasound (CIMU) at the Applied Physics Laboratory in the University of Washington has undertaken a broad research program in the general area of High Intensity Focused Ultrasound (HIFU). Our principal emphasis has been on the use of HIFU to induce hemostasis; in particular, CIMU has sought to develop a small, lightweight, portable device that would use ultrasound for both imaging and therapy. Such a technology is needed because nearly 50% of combat casualty mortality results from exsanguinations, or uncontrolled bleeding. A similar percentage occurs for civilian death due to trauma. In this general review, a presentation of the general problem will be given, as well as our recent approaches to the development of an image-guided, transcutaneous, acoustic hemostasis device. [Work supported in part by the USAMRMC, ONR and the NIH.

  16. Acoustic telemetry.

    SciTech Connect

    Drumheller, Douglas Schaeffer; Kuszmaul, Scott S.

    2003-08-01

    Broadcasting messages through the earth is a daunting task. Indeed, broadcasting a normal telephone conversion through the earth by wireless means is impossible with todays technology. Most of us don't care, but some do. Industries that drill into the earth need wireless communication to broadcast navigation parameters. This allows them to steer their drill bits. They also need information about the natural formation that they are drilling. Measurements of parameters such as pressure, temperature, and gamma radiation levels can tell them if they have found a valuable resource such as a geothermal reservoir or a stratum bearing natural gas. Wireless communication methods are available to the drilling industry. Information is broadcast via either pressure waves in the drilling fluid or electromagnetic waves in the earth and well tubing. Data transmission can only travel one way at rates around a few baud. Given that normal Internet telephone modems operate near 20,000 baud, these data rates are truly very slow. Moreover, communication is often interrupted or permanently blocked by drilling conditions or natural formation properties. Here we describe a tool that communicates with stress waves traveling through the steel drill pipe and production tubing in the well. It's based on an old idea called Acoustic Telemetry. But what we present here is more than an idea. This tool exists, it's drilled several wells, and it works. Currently, it's the first and only acoustic telemetry tool that can withstand the drilling environment. It broadcasts one way over a limited range at much faster rates than existing methods, but we also know how build a system that can communicate both up and down wells of indefinite length.

  17. Full-Field Imaging of GHz Film Bulk Acoustic Resonator Motion

    SciTech Connect

    Telschow, Kenneth Louis; Deason, Vance Albert; Cottle, David Lynn; Larson III, J. D.

    2003-10-01

    A full-field view laser ultrasonic imaging method has been developed that measures acoustic motion at a surface without scanning. Images are recorded at normal video frame rates by using dynamic holography with photorefractive interferometric detection. By extending the approach to ultra high frequencies, an acoustic microscope has been developed that is capable of operation at gigahertz frequency and micron length scales. Both acoustic amplitude and phase are recorded, allowing full calibration and determination of phases to within a single arbitrary constant. Results are presented of measurements at frequencies of 800-900 MHz, illustrating a multitude of normal mode behavior in electrically driven thin film acoustic resonators. Coupled with microwave electrical impedance measurements, this imaging mode provides an exceptionally fast method for evaluation of electric-to-acoustic coupling of these devices and their performance. Images of 256 /spl times/ 240 pixels are recorded at 18 fps rates synchronized to obtain both in-phase and quadrature detection of the acoustic motion. Simple averaging provides sensitivity to the subnanometer level at each pixel calibrated over the image using interferometry. Identification of specific acoustic modes and their relationship to electrical impedance characteristics show the advantages and overall high speed of the technique.

  18. H(+)/solute-induced intracellular acidification leads to selective activation of apical Na(+)/H(+) exchange in human intestinal epithelial cells.

    PubMed

    Thwaites, D T; Ford, D; Glanville, M; Simmons, N L

    1999-09-01

    The intestinal absorption of many nutrients and drug molecules is mediated by ion-driven transport mechanisms in the intestinal enterocyte plasma membrane. Clearly, the establishment and maintenance of the driving forces - transepithelial ion gradients - are vital for maximum nutrient absorption. The purpose of this study was to determine the nature of intracellular pH (pH(i)) regulation in response to H(+)-coupled transport at the apical membrane of human intestinal epithelial Caco-2 cells. Using isoform-specific primers, mRNA transcripts of the Na(+)/H(+) exchangers NHE1, NHE2, and NHE3 were detected by RT-PCR, and identities were confirmed by sequencing. The functional profile of Na(+)/H(+) exchange was determined by a combination of pH(i), (22)Na(+) influx, and EIPA inhibition experiments. Functional NHE1 and NHE3 activities were identified at the basolateral and apical membranes, respectively. H(+)/solute-induced acidification (using glycylsarcosine or beta-alanine) led to Na(+)-dependent, EIPA-inhibitable pH(i) recovery or EIPA-inhibitable (22)Na(+) influx at the apical membrane only. Selective activation of apical (but not basolateral) Na(+)/H(+) exchange by H(+)/solute cotransport demonstrates that coordinated activity of H(+)/solute symport with apical Na(+)/H(+) exchange optimizes the efficient absorption of nutrients and Na(+), while maintaining pH(i) and the ion gradients involved in driving transport. PMID:10487777

  19. The H2S Donor NaHS Changes the Expression Pattern of H2S-Producing Enzymes after Myocardial Infarction.

    PubMed

    Li, Na; Wang, Ming-Jie; Jin, Sheng; Bai, Ya-Dan; Hou, Cui-Lan; Ma, Fen-Fen; Li, Xing-Hui; Zhu, Yi-Chun

    2016-01-01

    Aims. To examine the expression patterns of hydrogen sulphide- (H2S-) producing enzymes in ischaemic heart tissue and plasma levels of H2S after 2 weeks of NaHS treatment after myocardial infarction (MI) and to clarify the role of endogenous H2S in the MI process. Results. After MI surgery, 2 weeks of treatment with the H2S donor NaHS alleviated ischaemic injury. Meanwhile, in ischemia myocardium, three H2S-producing enzymes, cystathionine γ-lyase (CSE), cystathionine-β-synthase (CBS), and 3-mercaptopyruvate sulfurtransferase (3-MST) significantly increased. Plasma H2S levels were also elevated. In vitro, NaHS treatment protected cardiomyocytes from hypoxic injury and raised CBS levels in a concentration-dependent manner. Different from in vivo results, however, CSE or 3-MST expression did not change. NaHS treatment increased the activity of CSE/CBS but not of 3-MST. When CSE was either knocked down (in vitro) or knocked out (in vivo), H2S levels significantly decreased, which subsequently exacerbated the ischaemic injury. Meanwhile, the expressions of CBS and 3-MST increased due to compensation. Conclusions. Exogenous H2S treatment changed the expressions of three H2S-producing enzymes and H2S levels after MI, suggesting a new and indirect regulatory mechanism for H2S production and its contribution to cardiac protection. Endogenous H2S plays an important role in protecting ischaemic tissue after MI. PMID:27057284

  20. Color holography: a new technique for reproduction of paintings

    NASA Astrophysics Data System (ADS)

    Bjelkhagen, Hans I.; Vukicevic, Dalibor

    2002-06-01

    Until recently, display holography was usually associate with 3D imaging. After the appearance of color holography it has become possible, however, to record holographic images of 2D objects, such as, for example, oil paintings. The realistic-looking virtual image recorded in a Denisyuk reflection hologram is the most suitable for such reproductions. A holographic contact recording of a painting reproduces the painting with all its texture details preserved, such as brush strokes, the painter's signature, etc. This means that an exact copy of the painting can be made, which can then be displayed at art exhibitions, museums, etc., when the original is not available. If an expensive painting is concerned, possessing an exact copy of the painting may also be important for insurance purposes, in case the painting is stolen or damaged. The advantage of a color contact hologram is that the hologram reconstruction process can be relaxed, as there is no need of spatial coherence of the white light source used to illuminate the hologram. In addition, no depth distortions are introduced as a function of the light source's distance from the plate. Only the angel of illumination is of primary importance if good color reproduction is to be obtained. The paper discusses the rendition of color in hologram, which is extremely important in this case. The holographic reproduction process of an oil painting is also described, and the major advantages of holographic reproduction are discussed together with its limitations.

  1. Ultra wide band 3-D cross section (RCS) holography

    SciTech Connect

    Collins, H.D.; Hall, T.E.

    1992-07-01

    Ultra wide band impulse holography is an exciting new concept for predictive radar cross section (RCS) evaluation employing near-field measurements. Reconstruction of the near-field hologram data maps the target's scattering areas, and uniquely identifies the hot spot'' locations on the target. In addition, the target and calibration sphere's plane wave angular spectrums are computed (via digital algorithm) and used to generate the target's far-field RCS values in three dimensions for each frequency component in the impulse. Thin and thick targets are defined in terms of their near-field amplitude variations in range. Range gating and computer holographic techniques are applied to correct these variations. Preliminary experimental results on various targets verify the concept of RCS holography. The unique 3-D presentation (i.e., typically containing 524,288 RCS values for a 1024 {times} 512 sampled aperture for every frequency component) illustrates the efficacy of target recognition in terms of its far-field plane wave angular spectrum image. RCS images can then be viewed at different angles for target recognition, etc.

  2. Ultra wide band 3-D cross section (RCS) holography

    SciTech Connect

    Collins, H.D.; Hall, T.E.

    1992-07-01

    Ultra wide band impulse holography is an exciting new concept for predictive radar cross section (RCS) evaluation employing near-field measurements. Reconstruction of the near-field hologram data maps the target`s scattering areas, and uniquely identifies the ``hot spot`` locations on the target. In addition, the target and calibration sphere`s plane wave angular spectrums are computed (via digital algorithm) and used to generate the target`s far-field RCS values in three dimensions for each frequency component in the impulse. Thin and thick targets are defined in terms of their near-field amplitude variations in range. Range gating and computer holographic techniques are applied to correct these variations. Preliminary experimental results on various targets verify the concept of RCS holography. The unique 3-D presentation (i.e., typically containing 524,288 RCS values for a 1024 {times} 512 sampled aperture for every frequency component) illustrates the efficacy of target recognition in terms of its far-field plane wave angular spectrum image. RCS images can then be viewed at different angles for target recognition, etc.

  3. The implementation of holography in the plane wave matrix model

    NASA Astrophysics Data System (ADS)

    Mints, Aleksey Leonidovich

    It is expected that at the core of nonperturbative theories of quantum gravity, such as M-theory, lies the realization of the holographic principle, in the sense that a holographic theory should contain one binary degree of freedom per Planck area. Present understanding of such theories requires the holographic encoding of bulk data in large matrices. Currently this mapping is poorly understood. The plane wave matrix model provides a laboratory for isolating aspects of this problem in a controlled setting. At large boosts, configurations of concentric membranes become superselection sectors, whose exact spectra are known. From the bulk point of view one expects product states of individual membranes to be contained within the full spectrum. However, for non-BPS states this inclusion relation is obscured by Gauss law constraints. Its validity rests on nontrivial relations in representation theory, which we identify and verify by explicit computation. Beyond the decoding and partial identification of selected states in large matrices, one would like to get a better understanding of the holographic state counting of these degrees of freedom, i.e., entropy. Contrary to the naive expectation of holography realized in terms of the covariant entropy bound, we present evidence that it is the Bekenstein entropy bound, which is related to area differences, that is manifest in the plane wave matrix model. If holography is implemented in this way, we predict crossover behavior at strong coupling when the energy exceeds N2 in units of the mass scale.

  4. SHIVA-(Spaceflight Holography in a Virtual Apparatus)

    NASA Technical Reports Server (NTRS)

    Trolinger, James D.; LaI, Ravindra B.; Rangel, Roger; Coimbra, Carlos; Witherow William; Rogers, Jan

    2001-01-01

    SHIVA (Spaceflight Holography Investigation in a Virtual Apparatus) will expand our understanding of the fundamental physics of particle movement in fluids by exploiting the power of holography in a spaceflight experiment'. In addition, the study will exploit the movement of particles in fluids to observe and quantify microgravity phenomena that are extremely important in materials sciences with applications both in space and on earth. The regime under scrutiny is the low Reynolds number, Stokes regime or creeping flow, which covers particles and bubbles moving at very low velocity. The equations describing this important regime have been under development and investigation for over 100 years and yet a complete analytical solution of the general equation had remained elusive yielding only approximations and numerical solutions. In the course of the ongoing NASA NRA, the first analytical solution of the general equation was produced by members of the investigator team using the mathematics of fractional derivatives. This opened the way to an even more insightful and important investigation of the phenomena in microgravity.

  5. Alignment of master and sample in comparative digital holography

    NASA Astrophysics Data System (ADS)

    Schwab, Xavier; Meister, Eugen; Pedrini, Giancarlo; Osten, Wolfgang

    2006-08-01

    A comparative digital holography system suitable for shape and deformation comparisons between master and sample objects with rough surfaces is described. The innovative aspect of comparative digital holography is the illumination of the sample by the conjugated wavefront of the master, as a type of coherent mask, using a liquid crystal display (LCD). The resulting interferogram indicates directly the shape or the deformation differences between the master and sample. As it is not necessary that both objects to be compared are located at the same place for this technique, remote shape or deformation comparison between a master and a sample is possible. A current research topic is the precise alignment of the sample and the reconstructed master wavefront so that the resulting phase map only contains information of the differences in shape or deformation. The reconstructed master wavefront can be adjusted digitally to correctly illuminate the sample object, by introducing an artificial phase-shift. This phase-shift is induced by the LCD, and offers also the possibility of calibrating precisely the set-up. The value for the phase-shift is obtained by a comparison of the resulting interferogram with a database containing fringes from simulations of misalignments between master and sample objects. Using the iterative algorithm described here, the correction of the sample position can be controlled by an automatic adaptation of the coherent mask.

  6. Intellectual property licensing issues in the holography business

    NASA Astrophysics Data System (ADS)

    Gortych, Joseph E.

    2006-02-01

    Increasingly, many high-tech companies are acquiring or transferring "leases" to the innovations used to make products. In legal parlance, these innovations-which may include new manufacturing methods, applications, devices or improvements-are considered "intellectual property" (IP), and the "leases" are referred to as "licenses." The holography business, like many other high-tech businesses, has evolved over many decades and consists of many densely packed IP subspaces. However, the IP space is constantly expanding through the development of new innovations and applications, such as security and storage applications, and new materials. Additionally, like most IP, the quality and business value of holographic IP ranges widely, which makes for a challenging IP licensing environment. This paper addresses IP licensing issues in the holography business, including some basics about the forms of IP and the basic types of IP licenses, the role of an IP space analysis in licensing activities, best-practice management of licensing activities, and how IP is properly scrutinized to assess licensing potential. The concept of the patent pool is discussed in connection with security holograms as well as other technologies.

  7. 25 Years Of Holography The Development Of Holographic Testing

    NASA Astrophysics Data System (ADS)

    Rottenkolber, H.

    1988-06-01

    It was of course Dennis Gabor who, as long ago as 1948, published the fundamental work the principle of holography. But it was not until Theodore Maiman's invention of the laser in 1960 that the practical realisation of holography became possible. This was achieved by Leith and Upatnicks between 1962 and 1964, with the crucial impetus being provided by Vander Lugt (the author wishes to acknowledge the assistence of A. Vander Lugt, who, while performing work of a relatet nature, showed him the value of the gas laser as a light source). 1964 was the year in which Denisyuk presented his first portrait holograms in Leningrad. The many publications of Stroke of the University of New York were a source of numerous impulses. It is to this period, too, that my own first experiences date back. Together with my teacher. Ulrich Grigull, whom I hold in the highest regard, I constructed the first laser interferometer for the study of heat transfer and developed the initial ideas for holo-graphic interferometry. Then, in 1965, came the work of Hildebrandt and Haines and of Powell and Stetson in the United States in this field, and it was around this time, too, that Nassenstein and his colleagues Riek and Bestenreiner began their work in this new area in Germany.

  8. Virtual gallery of ancient coins through conoscopic holography

    NASA Astrophysics Data System (ADS)

    Schirripa Spagnolo, Giuseppe; Majo, Raffaele; Carli, Marco; Ambrosini, Dario; Paoletti, Domenica

    2003-10-01

    Physical access to historic and artistic manufactures can be limited by a lot of factors. In particular, the access to the collection of the ancient coins is difficult, especially for students. Indeed, for coins digital archive of high quality three-dimensional model and remote fruition is of great interest. In this work we propose 3D acquisition and digitizing techniques for the virtualized reality of ancient coins (virtual gallery). The system used for creating 3D shape of coins is based on conoscopic holography. This technique is a non-contact three-dimensional measuring technique that makes possible to produce holograms, even with incoherent light, with fringe periods that can be measured precisely to determine the exact distance to the point measured. It is suitable to obtain 3D profile with high resolution also on surface with unevenness reflectivity (this situation is usual on the surface of the ancient coins). By conoscopic holography, high-resolution 3D model can be obtained. However, accurate representation and high-quality display are fundamental requirements to avoid misinterpretation of the data. Therefore, virtual galleries can be obtained through a procedure involving 3D acquisition, 3D model and visualization. In conclusion, we propose an optoelectronic application, integrated with multimedia techniques, in order to improve the access to collection of ancient coins belonging to museums or privates.

  9. Volumetric multiplexed transmission holography of the heart with echocardiographic data.

    PubMed

    Vannan, M A; Cao, Q L; Pandian, N G; Sugeng, L; Schwartz, S L; Dalton, M N

    1995-01-01

    Three-dimensional imaging enhances delineation of cardiac anatomy and function. Currently, three-dimensional echocardiography involves complex rendering techniques to imply depth in a given image. Also, display of the final images on a video monitor neutralizes the volume information of the object. A hologram is a true, three-dimensional replica of the original object and does not entail complex data processing. Holography has not been used previously in cardiovascular imaging. In this experiment, 11 excised mammalian whole hearts and five isolated left ventricles were imaged in a water bath. Parallel, tomographic, echocardiographic images comprised the data source from which holograms were obtained by the technique of multiplexed holography. Holograms were mounted on a holographic film and viewed in a special viewing box. High-quality holograms were obtained from every data set. Excellent gray-scale discrimination allowed crisp visualization of cardiac structures and simulated diseases. Electronic sectioning and various projections optimized viewing of the three-dimensional anatomy in surgical orientations. Thus holograms can be produced from tomographic cardiac ultrasound data and could open a new avenue in three-dimensional echocardiography. PMID:9417198

  10. Response of bacterial pdo1, nah, and C12O genes to aged soil PAH pollution in a coke factory area.

    PubMed

    Han, Xue-Mei; Liu, Yu-Rong; Zheng, Yuan-Ming; Zhang, Xiao-Xia; He, Ji-Zheng

    2014-01-01

    Soil pollution caused by polycyclic aromatic hydrocarbons (PAHs) is threatening human health and environmental safety. Investigating the relative prevalence of different PAH-degrading genes in PAH-polluted soils and searching for potential bioindicators reflecting the impact of PAH pollution on microbial communities are useful for microbial monitoring, risk evaluation, and potential bioremediation of soils polluted by PAHs. In this study, three functional genes, pdo1, nah, and C12O, which might be involved in the degradation of PAHs from a coke factory, were investigated by real-time quantitative PCR (qPCR) and clone library approaches. The results showed that the pdo1 and C12O genes were more abundant than the nah gene in the soils. There was a significantly positive relationship between the nah or pdo1 gene abundances and PAH content, while there was no correlation between C12O gene abundance and PAH content. Analyses of clone libraries showed that all the pdo1 sequences were grouped into Mycobacterium, while all the nah sequences were classified into three groups: Pseudomonas, Comamonas, and Polaromonas. These results indicated that the abundances of nah and pdo1 genes were positively influenced by levels of PAHs in soil and could be potential microbial indicators reflecting the impact of soil PAH pollution and that Mycobacteria were one of the most prevalent PAHs degraders in these PAH-polluted soils. Principal component analysis (PCA) and correlation analyses between microbial parameters and environmental factors revealed that total carbon (TC), total nitrogen (TN), and dissolved organic carbon (DOC) had positive effects on the abundances of all PAH-degrading genes. It suggests that increasing TC, TN, and DOC inputs could be a useful way to remediate PAH-polluted soils. PMID:24777329

  11. Analysis of cardiovascular responses to the H2S donors Na2S and NaHS in the rat

    PubMed Central

    Yoo, Daniel; Jupiter, Ryan C.; Pankey, Edward A.; Reddy, Vishwaradh G.; Edward, Justin A.; Swan, Kevin W.; Peak, Taylor C.; Mostany, Ricardo

    2015-01-01

    Hydrogen sulfide (H2S) is an endogenous gaseous molecule formed from L-cysteine in vascular tissue. In the present study, cardiovascular responses to the H2S donors Na2S and NaHS were investigated in the anesthetized rat. The intravenous injections of Na2S and NaHS 0.03–0.5 mg/kg produced dose-related decreases in systemic arterial pressure and heart rate, and at higher doses decreases in cardiac output, pulmonary arterial pressure, and systemic vascular resistance. H2S infusion studies show that decreases in systemic arterial pressure, heart rate, cardiac output, and systemic vascular resistance are well-maintained, and responses to Na2S are reversible. Decreases in heart rate were not blocked by atropine, suggesting that the bradycardia was independent of parasympathetic activation and was mediated by an effect on the sinus node. The decreases in systemic arterial pressure were not attenuated by hexamethonium, glybenclamide, Nw-nitro-l-arginine methyl ester hydrochloride, sodium meclofenamate, ODQ, miconazole, 5-hydroxydecanoate, or tetraethylammonium, suggesting that ATP-sensitive potassium channels, nitric oxide, arachidonic acid metabolites, cyclic GMP, p450 epoxygenase metabolites, or large conductance calcium-activated potassium channels are not involved in mediating hypotensive responses to the H2S donors in the rat and that responses are not centrally mediated. The present data indicate that decreases in systemic arterial pressure in response to the H2S donors can be mediated by decreases in vascular resistance and cardiac output and that the donors have an effect on the sinus node independent of the parasympathetic system. The present data indicate that the mechanism of the peripherally mediated hypotensive response to the H2S donors is uncertain in the intact rat. PMID:26071540

  12. The biophysical and molecular basis of intracellular pH sensing by Na+/H+ exchanger-3

    PubMed Central

    Babich, Victor; Vadnagara, Komal; Di Sole, Francesca

    2013-01-01

    Epithelial Na+/H+ exchanger-3 (NHE3) transport is fundamental for renal and intestinal sodium reabsorption. Cytoplasmic protons are thought to serve as allosteric modifiers of the exchanger and to trigger its transport through protein conformational change. This effect presupposes an intracellular pH (pHi) dependence of NHE3 activity, although the biophysical and molecular basis of NHE3 pHi sensitivity have not been defined. NHE3, when complexed with the calcineurin homologous protein-1 (CHP1), had a shift in pHi sensitivity (0.4 units) toward the acidic side in comparison with NHE3 alone, as measured by oscillating pH electrodes combined with whole-cell patch clamping. Indeed, CHP1 interaction with NHE3 inhibited NHE3 transport in a pHi -dependent manner. CHP1 binding to NHE3 also affected its acute regulation. Intracellular perfusion of peptide from the CHP1 binding region (or pHi modification to reduce the CHP1 amount bound to NHE3) was permissive and cooperative for dopamine inhibition of NHE3 but reversed that of adenosine. Thus, CHP1 interaction with NHE3 apparently establishes the exchanger set point for pHi, and modification in this set point is effective in the hormonal stimuli–mediated regulation of NHE3. CHP1 may serve as a regulatory cofactor for NHE3 conformational change, dependent on intracellular protonation.—Babich V., Vadnagara K., Di Sole, F. The biophysical and molecular basis of intracellular pH sensing by the Na+/H+ exchanger-3. PMID:23934281

  13. A hydrophobic filter confers the cation selectivity of Zygosaccharomyces rouxii plasma-membrane Na+/H+ antiporter.

    PubMed

    Kinclova-Zimmermannova, Olga; Falson, Pierre; Cmunt, Denis; Sychrova, Hana

    2015-04-24

    Na(+)/H(+) antiporters may recognize all alkali-metal cations as substrates but may transport them selectively. Plasma-membrane Zygosaccharomyces rouxii Sod2-22 antiporter exports Na(+) and Li(+), but not K(+). The molecular basis of this selectivity is unknown. We combined protein structure modeling, site-directed mutagenesis, phenotype analysis and cation efflux measurements to localize and characterize the cation selectivity region. A three-dimensional model of the ZrSod2-22 transmembrane domain was generated based on the X-ray structure of the Escherichia coli NhaA antiporter and primary sequence alignments with homologous yeast antiporters. The model suggested a close proximity of Thr141, Ala179 and Val375 from transmembrane segments 4, 5 and 11, respectively, forming a hydrophobic hole in the putative cation pathway's core. A series of mutagenesis experiments verified the model and showed that structural modifications of the hole resulted in altered cation selectivity and transport activity. The triple ZrSod2-22 mutant T141S-A179T-V375I gained K(+) transport capacity. The point mutation A179T restricted the antiporter substrate specificity to Li(+) and reduced its transport activity, while serine at this position preserved the native cation selectivity. The negative effect of the A179T mutation can be eliminated by introducing a second mutation, T141S or T141A, in the preceding transmembrane domain. Our experimental results confirm that the three residues found through modeling play a central role in the determination of cation selectivity and transport activity in Z. rouxii Na(+)/H(+) antiporter and that the cation selectivity can be modulated by repositioning a single local methyl group. PMID:25701798

  14. Holography: Use in Training and Testing Drivers on the Road in Accident Avoidance.

    ERIC Educational Resources Information Center

    Frey, Allan H.; Frey, Donnalyn

    1979-01-01

    Defines holography, identifies visual factors in driving and the techniques used in on-road visual presentations, and presents the design and testing of a holographic system for driver training. (RAO)

  15. Acoustic hemostasis

    NASA Astrophysics Data System (ADS)

    Crum, Lawrence; Beach, Kirk; Carter, Stephen; Chandler, Wayne; Curra, Francesco; Kaczkowski, Peter; Keilman, George; Khokhlova, Vera; Martin, Roy; Mourad, Pierre; Vaezy, Shahram

    2000-07-01

    In cases of severe injury, physicians speak of a "golden hour"—a brief grace period in which quickly applied, proper therapy can save the life of the patient. Much of this mortality results from exsanguination, i.e., bleeding to death—often from internal hemorrhage. The inability of a paramedic to treat breaches in the vascular system deep within the body or to stem the loss of blood from internal organs is a major reason for the high level of mortality associated with blunt trauma. We have undertaken an extensive research program to treat the problem of internal bleeding. Our approach is as follows: (a) We use scanning ultrasound to identify internal bleeding and hemorrhage, (b) we use ultrasound imaging to locate specific breaches in the vascular system, both from damaged vessels and gross damage to the capillary bed, and (c) we use High Intensity Focused Ultrasound (HIFU) to treat the damaged region and to induce hemostasis. We present a general review of this research with some emphasis on the role of nonlinear acoustics.

  16. The application of digital image plane holography technology to identify Chinese herbal medicine

    NASA Astrophysics Data System (ADS)

    Wang, Huaying; Guo, Zhongjia; Liao, Wei; Zhang, Zhihui

    2011-11-01

    In this paper, the imaging technology of digital image plane holography to identify the Chinese herbal medicine is studied. The optical experiment system of digital image plane holography which is the special case of pre-magnification digital holography was built. In the record system, one is an object light by using plane waves which illuminates the object, and the other one is recording hologram by using spherical light wave as reference light. There is a Micro objective lens behind the object. The second phase factor which caus ed by the Micro objective lens can be eliminated by choosing the proper position of the reference point source when digital image plane holography is recorded by spherical light. In this experiment, we use the Lygodium cells and Onion cells as the object. The experiment results with Lygodium cells and Onion cells show that digital image plane holography avoid the process of finding recording distance by using auto-focusing approach, and the phase information of the object can be reconstructed more accurately. The digital image plane holography is applied to the microscopic imaging of cells more effectively, and it is suit to apply for the identify of Chinese Herbal Medicine. And it promotes the application of digital holographic in practice.

  17. The application of digital image plane holography technology to identify Chinese herbal medicine

    NASA Astrophysics Data System (ADS)

    Wang, Huaying; Guo, Zhongjia; Liao, Wei; Zhang, Zhihui

    2012-03-01

    In this paper, the imaging technology of digital image plane holography to identify the Chinese herbal medicine is studied. The optical experiment system of digital image plane holography which is the special case of pre-magnification digital holography was built. In the record system, one is an object light by using plane waves which illuminates the object, and the other one is recording hologram by using spherical light wave as reference light. There is a Micro objective lens behind the object. The second phase factor which caus ed by the Micro objective lens can be eliminated by choosing the proper position of the reference point source when digital image plane holography is recorded by spherical light. In this experiment, we use the Lygodium cells and Onion cells as the object. The experiment results with Lygodium cells and Onion cells show that digital image plane holography avoid the process of finding recording distance by using auto-focusing approach, and the phase information of the object can be reconstructed more accurately. The digital image plane holography is applied to the microscopic imaging of cells more effectively, and it is suit to apply for the identify of Chinese Herbal Medicine. And it promotes the application of digital holographic in practice.

  18. Searching for Traces of Martian Life Using Holography

    NASA Astrophysics Data System (ADS)

    Ksanfomality, Leonid; Kompanets, Igor

    A sample of the Martian regolith to be delivered in future missions to Mars may provide an important information on traces of the extinct life when studied in the laboratory. Of course, there will be only few samples (by technical reasons) and their structure will inevitably be distorted by the extracting mechanisms. There is an another possibility, looking for a morphology sign affected by life, using a special TV camera, too. However it is very difficult to return an information of this kind of the TV, mainly due to the enormous amount of the information to be returned. The proposal made in this paper is to use a holography technics collecting many shots of undistorted objects on the surface of Mars using a special photosensitive film, and to return the film together with a soil sample. The mass of the film roll is neglectable when compared with a package of a soil sample. The holograph experiment results are a lot more informative then the stereo (two points of view), having the number points of view = object solid angle / solid angle resolution. The object may be examined from many sides. A resolution of such a film may be up to 5000 lines/mm, that is much, much higher than any TV image. The instrument proposed for the project is based on the most advanced new investigations in the holography, that permits to minimize (4 to 6 fold) the mass, sizes an power assumption of the camera. The goal of the project is to investigate micro morphology of the Martian surface features (stones, sand, dust). The Camera Specification (preliminary) Mass & Less than 4 kg Sizes (mm) & 300 times 100 times 150 Power assumption & averaged < 1W, pulse up to 100W. Lazer & YAG (Nd), 2nd harmonic Wavelength & 530 nm Structure & Fiber optics Photo film & High resolution (up to 5000 mm^{-1}) Object maximum size (mm)& 100 Frame size (mm) & 100 times 250 Number of shots & 12-20 In some sense all things, now widely used in space research, were risky innovations in the past. A holograph in

  19. Acoustic source for generating an acoustic beam

    DOEpatents

    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.

  20. What Is an Acoustic Neuroma

    MedlinePlus

    ... Acoustic Neuroma An acoustic neuroma, also called a vestibular schwannoma, is a rare benign tumor of the ... Acoustic Neuroma? An acoustic neuroma, known as a vestibular schwannoma, is a benign (non-cancerous) growth that ...

  1. Canonical Acoustics and Its Application to Surface Acoustic Wave on Acoustic Metamaterials

    NASA Astrophysics Data System (ADS)

    Shen, Jian Qi

    2016-08-01

    In a conventional formalism of acoustics, acoustic pressure p and velocity field u are used for characterizing acoustic waves propagating inside elastic/acoustic materials. We shall treat some fundamental problems relevant to acoustic wave propagation alternatively by using canonical acoustics (a more concise and compact formalism of acoustic dynamics), in which an acoustic scalar potential and an acoustic vector potential (Φ ,V), instead of the conventional acoustic field quantities such as acoustic pressure and velocity field (p,u) for characterizing acoustic waves, have been defined as the fundamental variables. The canonical formalism of the acoustic energy-momentum tensor is derived in terms of the acoustic potentials. Both the acoustic Hamiltonian density and the acoustic Lagrangian density have been defined, and based on this formulation, the acoustic wave quantization in a fluid is also developed. Such a formalism of acoustic potentials is employed to the problem of negative-mass-density assisted surface acoustic wave that is a highly localized surface bound state (an eigenstate of the acoustic wave equations). Since such a surface acoustic wave can be strongly confined to an interface between an acoustic metamaterial (e.g., fluid-solid composite structures with a negative dynamical mass density) and an ordinary material (with a positive mass density), it will give rise to an effect of acoustic field enhancement on the acoustic interface, and would have potential applications in acoustic device design for acoustic wave control.

  2. Extreme-ultraviolet lensless Fourier-transform holography.

    PubMed

    Lee, S H; Naulleau, P; Goldberg, K A; Cho, C H; Jeong, S; Bokor, J

    2001-06-01

    We demonstrate 100-nm-resolution holographic aerial image monitoring based on lensless Fourier-transform holography at extreme-UV (EUV) wavelengths, using synchrotron-based illumination. This method can be used to monitor the coherent imaging performance of EUV lithographic optical systems. The system has been implemented in the EUV phase-shifting point-diffraction interferometer recently developed at Lawrence Berkeley National Laboratory. Here we introduce the idea of the holographic aerial image-recording technique and present imaging performance characterization results for a 10x Schwarzschild objective, a prototype EUV lithographic optic. The results are compared with simulations, and good agreement is obtained. Various object patterns, including phase-shift-enhanced patterns, have been studied. Finally, the application of the holographic aerial image-recording technique to EUV multilayer mask-blank defect characterization is discussed. PMID:18357280

  3. Spectroscopic imaging, diffraction, and holography with x-ray photoemission

    SciTech Connect

    Not Available

    1992-02-01

    X-ray probes are capable of determining the spatial structure of an atom in a specific chemical state, over length scales from about a micron all the way down to atomic resolution. Examples of these probes include photoemission microscopy, energy-dependent photoemission diffraction, photoelectron holography, and X-ray absorption microspectroscopy. Although the method of image formation, chemical-state sensitivity, and length scales can be very different, these X-ray techniques share a common goal of combining a capability for structure determination with chemical-state specificity. This workshop will address recent advances in holographic, diffraction, and direct imaging techniques using X-ray photoemission on both theoretical and experimental fronts. A particular emphasis will be on novel structure determinations with atomic resolution using photoelectrons.

  4. Surface-Plasmon Holography with White-Light Illumination

    NASA Astrophysics Data System (ADS)

    Ozaki, Miyu; Kato, Jun-ichi; Kawata, Satoshi

    2011-04-01

    The recently emerging three-dimensional (3D) displays in the electronic shops imitate depth illusion by overlapping two parallax 2D images through either polarized glasses that viewers are required to wear or lenticular lenses fixed directly on the display. Holography, on the other hand, provides real 3D imaging, although usually limiting colors to monochrome. The so-called rainbow holograms—mounted, for example, on credit cards—are also produced from parallax images that change color with viewing angle. We report on a holographic technique based on surface plasmons that can reconstruct true 3D color images, where the colors are reconstructed by satisfying resonance conditions of surface plasmon polaritons for individual wavelengths. Such real 3D color images can be viewed from any angle, just like the original object.

  5. Synthetic holography in microscopy: opportunities arising from advanced wavefront shaping

    NASA Astrophysics Data System (ADS)

    Jesacher, Alexander; Ritsch-Marte, Monika

    2016-01-01

    The advent of computer-generated or synthetic holography has created a wealth of possibilities for wavefront shaping in optics. We discuss the impact this has had on optical microscopy. Synthetic Holographic Microscopy utilises wavefront shaping by a computer-generated 'hologram' (CGH) to modify light on the illumination or the detection side, or both. This enables modifications of the general sample appearance concerning contrast, resolution and other aspects. Multiplexing CGHs can perform several tasks at once, for instance splitting the image into sub-images corresponding to different depths in the sample, or displaying differently contrasted images of the sample, e.g. bright field, darkfield or (spiral) phase contrast, in different sub-images. We give an overview of the options and discuss the advantages and disadvantages of using programmable holographic elements inside an optical microscope.

  6. A Study on Applications of Holography in Solar Energy Installations

    NASA Astrophysics Data System (ADS)

    Abbasi, Hamed; Granmayeh Rad, Adeleh; Zarei, Talie; Jalali Farahani, Neda

    In this paper, applications of holography in the solar energy, photovoltaic concentration, daylighting, illumination, and thermal blocking have been investigated. Holographic elements can be used to concentrate the radiation of the sun onto photovoltaic cells. Moreover the sun radiation is diffracted by the hologram. This has the advantage that proper photovoltaic cells can be installed in different spectral regions. Holographic daylighting systems can diffract sunlight efficiently up to the ceiling in the room. Holograms can be fabricated to reflect or block certain wavelength regions. Holograms are designed for a wavelength in the infrared region and a typical incidence angle of the summer sunlight. In this case the infrared radiation is reflected in the summer and heating of the rooms can be reduced, also, energy for cooling by air conditioners can be reduced. In winter, that the angle of incidence is smaller, a larger wavelength region is reflected, where the infrared intensity is very low.

  7. Local charge measurement using off-axis electron holography

    NASA Astrophysics Data System (ADS)

    Beleggia, M.; Gontard, L. C.; Dunin-Borkowski, R. E.

    2016-07-01

    A model-independent approach based on Gauss’ theorem for measuring the local charge in a specimen from an electron-optical phase image recorded using off-axis electron holography was recently proposed. Here, we show that such a charge measurement is reliable when it is applied to determine the total charge enclosed within an object. However, the situation is more complicated for a partial charge measurement when the integration domain encloses only part of the object. We analyze in detail the effects on charge measurement of the mean inner potential of the object, of the presence of induced charges on nearby supports/electrodes and of noise. We perform calculations for spherical particles and highlight the differences when dealing with other object shapes. Our analysis is tested using numerical simulations and applied to the interpretation of an experimental dataset recorded from a sapphire particle.

  8. Time-average TV holography for vibration fringe analysis

    SciTech Connect

    Kumar, Upputuri Paul; Kalyani, Yanam; Mohan, Nandigana Krishna; Kothiyal, Mahendra Prasad

    2009-06-01

    Time-average TV holography is widely used method for vibration measurement. The method generates speckle correlation time-averaged J0 fringes that can be used for full-field qualitative visualization of mode shapes at resonant frequencies of an object under harmonic excitation. In order to map the amplitudes of vibration, quantitative evaluation of the time-averaged fringe pattern is desired. A quantitative evaluation procedure based on the phase-shifting technique used in two beam interferometry has also been adopted for this application with some modification. The existing procedure requires a large number of frames to be recorded for implementation. We propose a procedure that will reduce the number of frames required for the analysis. The TV holographic system used and the experimental results obtained with it on an edge-clamped, sinusoidally excited square aluminium plate sample are discussed.

  9. Temporal phase conjugation based on time-domain holography.

    PubMed

    Fernández-Ruiz, María R; Azaña, José

    2015-01-01

    A novel, simple method for wavelength-preserving temporal phase conjugation (TPC) of complex optical waveforms is proposed and experimentally validated. The method is based on the concept of time-domain holography; it requires direct photo-detection of the original waveform mixed with a CW light beam (temporal hologram recording), followed by intensity-only modulation of a second CW light source with the photo-detected interference-like pattern. The conjugated signal is directly obtained from the modulated light through an optical bandpass filtering process, without requiring any further processing on the detected interferogram. The proposed scheme is successfully demonstrated by conjugating a train of arbitrarily chirped Gaussian-like pulses and a 3 Gbps 16-QAM data stream. PMID:25531626

  10. Gordon Research Conference on Holography and Optical Information Processing

    NASA Astrophysics Data System (ADS)

    Walkup, John F.

    1991-09-01

    The 1991 Gordon Research Conference on Holography and Optical Information Processing was held on 17-21 June, 1991 at Plymouth State College in Plymouth, NH. The talks on Ultrafast Optical Logic Using Solitons and Optical Processing with Planar Optics pointed out the significant progress being made by various Bell Labs investigators on various aspects of optical computing. Professor Sing Lee from the University of California-San Diego gave an excellent overview of some engineering and performance Issues in optoelectronic computing. It is clear that the Soviets have made considerable progress on multi transducer acousto-optic spectrum analyzers. It is also clear that the Japanese government is planning to continue to make optical computing one of its high priority areas, with its NIPT (New Information Processing Technology project), and are projected to continue to investigate so called sixth generation computer technologies.

  11. Real-time tomographic holography for augmented reality

    PubMed Central

    Galeotti, John M.; Siegel, Mel; Stetten, George

    2011-01-01

    The concept and instantiation of Real-Time Tomographic Holography (RTTH) for augmented reality is presented. RTTH enables natural hand-eye coordination to guide invasive medical procedures without requiring tracking or a head-mounted device. It places a real-time virtual image of an object's cross-section into its actual location, without noticeable viewpoint dependence (e.g. parallax error). The virtual image is viewed through a flat narrow-band Holographic Optical Element with optical power that generates an in-situ virtual image (within 1 m of the HOE) from a small SLM display without obscuring a direct view of the physical world. Rigidly fixed upon a medical ultrasound probe, an RTTH device could show the scan in its actual location inside the patient, even as the probe was moved relative to the patient. PMID:20634827

  12. Electron beam coherence measurements using diffracted beam interferometry/holography.

    PubMed

    Herring, Rodney A

    2009-06-01

    The intensity and coherence of elastically and inelastically scattered electrons have been studied by the interference of electron-diffracted beams using a method of diffracted beam interferometry/holography (DBI/H). In the interferograms produced, fringes were found to exist from low to high scattering angles. The intensity and coherence of the fringes are useful for understanding the contrast mismatch between experimental and simulated images found in atomic resolution images of crystals produced by transmission electron microscopy (TEM) and annular dark-field (ADF) scanning transmission electron microscopy (STEM). The fringes disappear when the interfering beams are separated from an exact overlay position, which produces a measurement of the beam's lateral coherence and holds promise for measuring the coherence of the respective quasi-particles associated with the energy loss electrons. PMID:19141592

  13. Microwave holography of large reflector antennas - Simulation algorithms

    NASA Technical Reports Server (NTRS)

    Rahmat-Samii, Y.

    1985-01-01

    The performance of large reflector antennas can be improved by identifying the location and amount of their surface distortions and correcting them. To determine the accuracy of the constructed surface profiles, simulation studies are used to incorporate both the effects of systematic and random distortions, particularly the effects of the displaced surface panels. In this paper, different simulation models are investigated, emphasizing a model based on the vector diffraction analysis of a curved reflector with displaced panels. The simulated far-field patterns are then used to reconstruct the location and amount of displacement of the surface panels by employing a fast Fourier transform/iterative procedure. The sensitivity of the microwave holography technique based on the number of far-field sampled points, level of distortions, polarizations, illumination tapers, etc., is also examined.

  14. SHIVA: Spaceflight Holography Investigation in a Virtual Apparatus

    NASA Technical Reports Server (NTRS)

    Trolinger, James D.; Rangel, Roger; Coimbra, Carlos; Lal, Ravindra B.; Witherow, William; Rogers, Jan

    2000-01-01

    SHIVA, a NASA spaceflight program, will exploit a unique, holography-based, diagnostics tool to test and apply a new, more general analytical solution to a fundamental equation of motion. The equation describes particle dynamics in fluids in a microgravity environment, and our solution represents the first analytical solution of it. When gravity is removed the equation becomes much more complex and had been solved previously only by numerical means. After our analytical solution has been validated it will be used as a tool for making additional measurements of the gravity environment. Our experiment will be optimized for testing the model, measuring g, g-jitter, and other microgravity phenomena. We will also collect data for which no current theory exists, This paper describes ground experiments and analysis that have been conducted by the investigator team to support the flight experiment.

  15. Holography-guided ptychography with soft X-rays.

    PubMed

    Hessing, Piet; Pfau, Bastian; Guehrs, Erik; Schneider, Michael; Shemilt, Laura; Geilhufe, Jan; Eisebitt, Stefan

    2016-01-25

    Ptychography is a lensless imaging technique that aims to reconstruct an object from a set of coherent diffraction patterns originating from different and partially overlapping sample illumination areas. For a successful convergence of the iterative algorithms used, the sample scan positions have to be known with very high accuracy. Here, we present a method that allows to directly encode this information in the diffraction patterns without the need of accurate position encoders. Our approach relies on combining ptychography with another coherent imaging method, namely Fourier-transform holography. We have imaged two different objects using coherent soft-X-ray illumination and investigate the influence of experimental and numerical position refinement on the reconstruction result. We demonstrate that holographically encoded positions significantly reduce the experimental and numerical requirements. Our ptychographic reconstructions cover a large field of view with diffraction-limited resolution and high sensitivity in the reconstructed phase shift and absorption of the objects. PMID:26832562

  16. Two-color holography concept (T-CHI)

    NASA Technical Reports Server (NTRS)

    Vikram, C. S.; Caulfield, H. J.; Workman, G. L.; Trolinger, J. D.; Wood, C. P.; Clark, R. L.; Kathman, A. D.; Ruggiero, R. M.

    1990-01-01

    The Material Processing in the Space Program of NASA-MSFC was active in developing numerous optical techniques for the characterization of fluids in the vicinity of various materials during crystallization and/or solidification. Two-color holographic interferometry demonstrates that temperature and concentration separation in transparent (T-CHI) model systems is possible. The experiments were performed for particular (succinonitrile) systems. Several solutions are possible in Microgravity Sciences and Applications (MSA) experiments on future Shuttle missions. The theory of the T-CHI concept is evaluated. Although particular cases are used for explanations, the concepts developed will be universal. A breadboard system design is also presented for ultimate fabrication and testing of theoretical findings. New developments in holography involving optical fibers and diode lasers are also incorporated.

  17. Double-Referential Holography and Spatial Quadrature Amplitude Modulation

    NASA Astrophysics Data System (ADS)

    Zukeran, Keisuke; Okamoto, Atsushi; Takabayashi, Masanori; Shibukawa, Atsushi; Sato, Kunihiro; Tomita, Akihisa

    2013-09-01

    We proposed a double-referential holography (DRH) that allows phase-detection without external additional beams. In the DRH, phantom beams, prepared in the same optical path as signal beams and preliminary multiplexed in a recording medium along with the signal, are used to produce interference fringes on an imager for converting a phase into an intensity distribution. The DRH enables stable and high-accuracy phase detection independent of the fluctuations and vibrations of the optical system owing to medium shift and temperature variation. Besides, the collinear arrangement of the signal and phantom beams leads to the compactness of the optical data storage system. We conducted an experiment using binary phase modulation signals for verifying the DRH operation. In addition, 38-level spatial quadrature amplitude modulation signals were successfully reproduced with the DRH by numerical simulation. Furthermore, we verified that the distributed phase-shifting method moderates the dynamic range consumption for the exposure of phantom beams.

  18. Time-averaged photon-counting digital holography.

    PubMed

    Demoli, Nazif; Skenderović, Hrvoje; Stipčević, Mario

    2015-09-15

    Time-averaged holography has been using photo-emulsions (early stage) and digital photo-sensitive arrays (later) to record holograms. We extend the recording possibilities by utilizing a photon-counting camera, and we further investigate the possibility of obtaining accurate hologram reconstructions in rather severe experimental conditions. To achieve this, we derived an expression for fringe function comprising the main parameters affecting the hologram recording. Influence of the main parameters, namely the exposure time and the number of averaged holograms, is analyzed by simulations and experiments. It is demonstrated that taking long exposure times can be avoided by averaging over many holograms with the exposure times much shorter than the vibration cycle. Conditions in which signal-to-noise ratio in reconstructed holograms can be substantially increased are provided. PMID:26371907

  19. Coherence experiments in single-pixel digital holography.

    PubMed

    Liu, Jung-Ping; Guo, Chia-Hao; Hsiao, Wei-Jen; Poon, Ting-Chung; Tsang, Peter

    2015-05-15

    In optical scanning holography (OSH), the coherence properties of the acquired holograms depend on the single-pixel size, i.e., the active area of the photodetector. For the first time, to the best of our knowledge, we have demonstrated coherent, partial coherent, and incoherent three-dimensional (3D) imaging by experiment in such a single-pixel digital holographic recording system. We have found, for the incoherent mode of OSH, in which the detector of the largest active area is applied, the 3D location of a diffusely reflecting object can be successfully retrieved without speckle noise. For the partial coherent mode employing a smaller pixel size of the detector, significant speckles and randomly distributed bright spots appear among the reconstructed images. For the coherent mode of OSH when the size of the pixel is vanishingly small, the bright spots disappear. However, the speckle remains and the signal-to-noise ratio is low. PMID:26393741

  20. Indefinite Plasmonic Beam Engineering by In-plane Holography.

    PubMed

    Chen, J; Li, L; Li, T; Zhu, S N

    2016-01-01

    Recent advances in controlling the optical phase at the sub-wavelength scale by meta-structures offer unprecedented possibilities in the beam engineering, holograms, and even invisible cloaks. In despite of developments of plasmonic beam engineering for definite beams, here, we proposed a new holographic strategy by in-plane diffraction process to access indefinite plasmonic beams, where a counterintuitive oscillating beam was achieved at a free metal surface that is against the common recognition of light traveling. Beyond the conventional hologram, our approach emphasizes on the phase correlation on the target, and casts an in-depth insight into the beam formation as a kind of long depth-of-field object. Moreover, in contrast to previous plasmonic holography with space light as references, our approach is totally fulfilled in a planar dimension that offers a thoroughly compact manipulation of the plasmonic near-field and suggests new possibilities in nanophotonic designs. PMID:27357133

  1. Indefinite Plasmonic Beam Engineering by In-plane Holography

    NASA Astrophysics Data System (ADS)

    Chen, J.; Li, L.; Li, T.; Zhu, S. N.

    2016-06-01

    Recent advances in controlling the optical phase at the sub-wavelength scale by meta-structures offer unprecedented possibilities in the beam engineering, holograms, and even invisible cloaks. In despite of developments of plasmonic beam engineering for definite beams, here, we proposed a new holographic strategy by in-plane diffraction process to access indefinite plasmonic beams, where a counterintuitive oscillating beam was achieved at a free metal surface that is against the common recognition of light traveling. Beyond the conventional hologram, our approach emphasizes on the phase correlation on the target, and casts an in-depth insight into the beam formation as a kind of long depth-of-field object. Moreover, in contrast to previous plasmonic holography with space light as references, our approach is totally fulfilled in a planar dimension that offers a thoroughly compact manipulation of the plasmonic near-field and suggests new possibilities in nanophotonic designs.

  2. Objective shearing digital holography for removing aberration from optical system.

    PubMed

    Pan, Weiqing; Tian, Kehan; Zhang, Chuhang

    2015-09-01

    We propose a new digital holography based on the lateral shearing interference concept to remove the total aberrations from the reference wave, illumination wave, and the optical elements. It uses three mutually shifted image holograms of the object that are divided from each other to obtain phase differences. The phase aberration can be removed and the original sample phase can be reconstructed by the phase differences. Then, the influence of the stage moving imprecision on the reconstruction quality is analyzed. Optical experiments verified that the proposed method can totally remove the phase aberrations. As a result, the proposed method could be used for ultra-precise optical measurement through eliminating optical phase aberration to increase the measurement accuracy. PMID:26368865

  3. Triboelectricity evaluation of single toner particle by electron holography

    SciTech Connect

    Okada, H.; Shindo, D.; Kim, J. J.; Murakami, Y.; Kawase, H.

    2007-09-01

    Understanding electrification is particularly important in materials science since the use of charged particles, e.g., the electrophotographic printer with toner particles, is one of the most successful applications of electrification. However, the charge generation mechanism still remains unclear due to the lack of an appropriate method for evaluating individual fine particles. In this study, we describe an approach for determining the charge of a single toner particle that uses electron holography in combination with a shielding technique. Two long-standing problems in holographic studies--namely, perturbation of the reference electron wave and unwanted charging by illumination--have been overcome by introducing two types of shields in a microscope. Using this method, the amount of charge on a single toner particle was determined, and the surface charge distribution was found to be inhomogeneous. Furthermore, an in situ observation of triboelectricity was conducted inside the microscope.

  4. Triboelectricity evaluation of single toner particle by electron holography

    NASA Astrophysics Data System (ADS)

    Okada, H.; Shindo, D.; Kim, J. J.; Murakami, Y.; Kawase, H.

    2007-09-01

    Understanding electrification is particularly important in materials science since the use of charged particles, e.g., the electrophotographic printer with toner particles, is one of the most successful applications of electrification. However, the charge generation mechanism still remains unclear due to the lack of an appropriate method for evaluating individual fine particles. In this study, we describe an approach for determining the charge of a single toner particle that uses electron holography in combination with a shielding technique. Two long-standing problems in holographic studies—namely, perturbation of the reference electron wave and unwanted charging by illumination—have been overcome by introducing two types of shields in a microscope. Using this method, the amount of charge on a single toner particle was determined, and the surface charge distribution was found to be inhomogeneous. Furthermore, an in situ observation of triboelectricity was conducted inside the microscope.

  5. Imaging velocities of a vibrating object by stroboscopic sideband holography.

    PubMed

    Verpillat, F; Joud, F; Atlan, M; Gross, M

    2012-09-24

    We propose here to combine sideband holography with stroboscopic illumination synchronized with the vibration of an object. By sweeping the optical frequency of the reference beam such a way the holographic detection is tuned on the successive sideband harmonic ranks, we are able to image the instantaneous velocities of the object. Since the stroboscopic illumination is made with an electronic device, the method is compatible with fast (up to several MHz) vibration motions. The method is demonstrated with a vibrating clarinet reed excited sinusoidally at 2 kHz, and a stroboscopic illumination with cyclic ratio 0.15. Harmonic rank up to n = ± 100 are detected, and a movie of the instantaneous velocities is reported. PMID:23037435

  6. THz holography in reflection using a high resolution microbolometer array.

    PubMed

    Zolliker, Peter; Hack, Erwin

    2015-05-01

    We demonstrate a digital holographic setup for Terahertz imaging of surfaces in reflection. The set-up is based on a high-power continuous wave (CW) THz laser and a high-resolution (640 × 480 pixel) bolometer detector array. Wave propagation to non-parallel planes is used to reconstruct the object surface that is rotated relative to the detector plane. In addition we implement synthetic aperture methods for resolution enhancement and compare Fourier transform phase retrieval to phase stepping methods. A lateral resolution of 200 μm and a relative phase sensitivity of about 0.4 rad corresponding to a depth resolution of 6 μm are estimated from reconstructed images of two specially prepared test targets, respectively. We highlight the use of digital THz holography for surface profilometry as well as its potential for video-rate imaging. PMID:25969190

  7. Indefinite Plasmonic Beam Engineering by In-plane Holography

    PubMed Central

    Chen, J.; Li, L.; Li, T.; Zhu, S. N.

    2016-01-01

    Recent advances in controlling the optical phase at the sub-wavelength scale by meta-structures offer unprecedented possibilities in the beam engineering, holograms, and even invisible cloaks. In despite of developments of plasmonic beam engineering for definite beams, here, we proposed a new holographic strategy by in-plane diffraction process to access indefinite plasmonic beams, where a counterintuitive oscillating beam was achieved at a free metal surface that is against the common recognition of light traveling. Beyond the conventional hologram, our approach emphasizes on the phase correlation on the target, and casts an in-depth insight into the beam formation as a kind of long depth-of-field object. Moreover, in contrast to previous plasmonic holography with space light as references, our approach is totally fulfilled in a planar dimension that offers a thoroughly compact manipulation of the plasmonic near-field and suggests new possibilities in nanophotonic designs. PMID:27357133

  8. Underwater digital holography for studies of marine plankton.

    PubMed

    Sun, H; Benzie, P W; Burns, N; Hendry, D C; Player, M A; Watson, J

    2008-05-28

    Conventional and digital holographies are proving to be increasingly important for studies of marine zooplankton and other underwater biological applications. This paper reports on the use of a subsea digital holographic camera (eHoloCam) for the analysis and identification of marine organisms and other subsea particles. Unlike recording on a photographic film, a digital hologram (e-hologram) is recorded on an electronic sensor and reconstructed numerically in a computer by simulating the propagation of the optical field in space. By comparison with other imaging techniques, an e-hologram has several advantages such as three-dimensional spatial reconstruction, non-intrusive and non-destructive interrogation of the recording sampling volume and the ability to record holographic videos. The basis of much work in optics lies in Maxwell's electromagnetic theory and holography is no exception: we report here on two of the numerical reconstruction algorithms we have used to reconstruct holograms obtained using eHoloCam and how their starting point lies in Maxwell's equations. Derivation of the angular spectrum algorithm for plane waves is provided as an exact method for the in-line numerical reconstruction of digital holograms. The Fresnel numerical reconstruction algorithm is derived from the angular spectrum method. In-line holograms are numerically processed before and after reconstruction to remove periodic noise from captured images and to increase image contrast. The ability of the Fresnel integration reconstruction algorithm to extend the reconstructed volume beyond the recording sensor dimensions is also shown with a 50% extension of the reconstruction area. Finally, we present some images obtained from recent deployments of eHoloCam in the North Sea and Faeroes Channel. PMID:18222904

  9. Stimulated LIF studied using pulsed digital holography and modelling

    NASA Astrophysics Data System (ADS)

    Amer, Eynas; Stenvall, Jonas; Gren, Per; Sjödahl, Mikael

    2013-04-01

    A frequency tripled Q-switched Nd-YAG laser (wavelength 355 nm, pulse duration 12 ns) has been used to pump Coumarin 153 dye solved in ethanol. The laser induced fluorescence (LIF) spectrum has been recorded using a spectrometer at different dye concentrations. The frequency doubled 532 nm beam from the same laser is used as a probe beam to pass through the excited volume of the dye. Because of stimulated emission an increase of the probe (532 nm) beam energy is recorded and a reduction of the spontaneous fluorescence spectrum intensity is observed. A model was developed that approaches the trend of the gain as a function of the probe beam energy at low dye concentrations (less than 0.08 g/L). The stimulated LIF is further recorded using digital holography. Digital holograms were recorded for different dye concentrations using collimated laser light (532 nm) passed through the dye volume. Two holograms without and with the UV laser beam were recorded. Intensity maps were calculated from the recorded digital holograms and are used to calculate the gain of the green laser beam due to the stimulated fluorescence emission which is coupled to the dye concentration. The gain of the coherent 532 nm beam is seen in the intensity maps and its value is about 40% for a dye concentration of 0.32 g/L and decreases with the decrease of the dye concentration. The results show that pulsed digital holography can be coupled to the stimulated LIF effect for imaging fluorescent species.

  10. Electron holography for the study of magnetic nanomaterials.

    PubMed

    Thomas, John Meurig; Simpson, Edward T; Kasama, Takeshi; Dunin-Borkowski, Rafal E

    2008-05-01

    Transmission electron microscopes fitted with field-emission guns (to provide coherent electron waves) can be adapted to record the magnetic fields within and surrounding nanoparticles or metal clusters, for example, the lines of force of a nanoferromagnet encapsulated within a multiwalled carbon nanotube. Whereas most chemists are aware that electron microscopy readily identifies crystallographic symmetries and phases, solves structures, and, in conjunction with electron energy-loss spectroscopy, yields valence states and electronic information of materials, relatively few know that it can also provide important quantitative information, with nanometer-scale spatial resolution, pertaining to such materials' magnetic properties. In this Account, with the aid of representative examples embracing solid-state chemistry, geochemistry, and bio-inorganic phenomena, we illustrate how off-axis electron holography affords deep insight into magnetic phenomena on the nanoscale. Specifically, we describe the unprecedented level of information available regarding the magnetic nature of magnetotactic bacteria, magnetic nanoparticle chains and chiral bracelets, and geochemically relevant phenomena involving exsolution (the un-mixing of two mineral phases, as in the magnetite-ulvöspinel system). It is, for example, possible to reveal vortices and multidomain states that have no net magnetization in minute blocks of magnetite. With the current burgeoning interest and activity in nanoscience and nanotechnology, our Account concludes with examples of some existing enigmas that electron holography, especially when augmented by the related technique of electron tomography, might play an important experimental role in resolving, such as the occurrence of ferromagnetism in nanocrystals of silver within carbon tubes and in clusters of alkali metals incarcerated within zeolites. PMID:18459804

  11. High-resolution lensless Fourier transform holography for microstructure imaging

    NASA Astrophysics Data System (ADS)

    Zhao, Jie; Wang, Dayong; Wang, Huaying; Xie, Jianjun

    2007-12-01

    Digital holography combines the advantages of the optical holography and the computers. It can implement an all-digital processing and has the quasi real-time property. With lensless Fourier transform recording architecture, the limited bandwidth of CCD camera can be utilized sufficiently, and the sampling theorem is satisfied easily. Therefore, high-resolution can be achieved. So it is preferred in the microstructure imaging. In the paper, based on the Fresnel diffraction theory and the off-axis lensless Fourier transform recording architecture, the experimental optimization and correspondingly the digital reconstruction was investigated. Also, the lateral resolution of the reconstructed image was analyzed and improved by the proposed techniques. When the USAF test target was imaged without any pre-magnification, the lateral resolution of 3.1μm was achieved, which matched the theoretical prediction very well. The key points to achieve high resolution image are to use the smaller object and to arrange the distance between the object and the CCD plane as short as possible. Meanwhile, properly overlapping the reconstructed image with the DC term was helpful to improve the resolution. The noise in the reconstructed image could be reduced greatly by choosing the optical elements precisely and adjusting the beam path finely. The experimental results demonstrated that it is possible for the digital holographic microscopy to produce the high resolution image without the objective pre-magnification. The results also showed that, with a high quality hologram, the special image processing during the reconstruction may be unnecessary to obtain a high quality image.

  12. Symptoms of Acoustic Neuroma

    MedlinePlus

    ... Watch and Wait Radiation Microsurgery Acoustic Neuroma Decision Tree Questions for Your Physician Questions to Ask Yourself ... Watch and Wait Radiation Microsurgery Acoustic Neuroma Decision Tree Questions for Your Physician Questions to Ask Yourself ...

  13. Acoustic emission frequency discrimination

    NASA Technical Reports Server (NTRS)

    Sugg, Frank E. (Inventor); Graham, Lloyd J. (Inventor)

    1988-01-01

    In acoustic emission nondestructive testing, broadband frequency noise is distinguished from narrow banded acoustic emission signals, since the latter are valid events indicative of structural flaws in the material being examined. This is accomplished by separating out those signals which contain frequency components both within and beyond (either above or below) the range of valid acoustic emission events. Application to acoustic emission monitoring during nondestructive bond verification and proof loading of undensified tiles on the Space Shuttle Orbiter is considered.

  14. Tutorial on architectural acoustics

    NASA Astrophysics Data System (ADS)

    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).

  15. Comparisons of the transferability of plasmids pCAR1, pB10, R388, and NAH7 among Pseudomonas putida at different cell densities.

    PubMed

    Yanagida, Kosuke; Sakuda, Ayako; Suzuki-Minakuchi, Chiho; Shintani, Masaki; Matsui, Kazuhiro; Okada, Kazunori; Nojiri, Hideaki

    2016-05-01

    The transferability of plasmids pCAR1, pB10, R388, and NAH7 was compared using the same donor-recipient system at different cell density combinations in liquid or on a solid surface. pCAR1 was efficiently transferred in liquid, whereas the other plasmids were preferentially transferred on a solid surface. Difference of liquid or solid affected the transfer frequency especially at lower cell densities. PMID:26806196

  16. Proteinases inhibit H(+)-ATPase and Na+/H+ exchange but not water transport in apical and endosomal membranes from rat proximal tubule.

    PubMed

    Sabolić, I; Shi, L B; Brown, D; Ausiello, D A; Verkman, A S

    1992-01-10

    A marked increase in water permeability can be induced in Xenopus oocytes by injection of mRNA from tissues that express water channels, suggesting that the water channel is a protein. In view of this and previous reports which showed that proteinases may interfere with mercurial inhibition of water transport in red blood cells (RBC), we examined the influence of trypsin, chymotrypsin, papain, pronase, subtilisin and thermolysin on water permeability as well as on ATPase activity, H(+)-pump, passive H+ conductance, and Na+/H+ exchange in apical brush-border vesicles (BBMV) and endosomal (EV) vesicles from rat renal cortex. H+ transport was measured by Acridine orange fluorescence quenching and water transport by stopped-flow light scattering. As measured by potential-driven H+ accumulation in BBMV and EV, proteinase treatment had little effect on vesicle integrity. In BBMV, ecto-ATPase activity was inhibited by 15-30%, Na+/H+ exchange by 20-55%, and H+ conductance was unchanged. Osmotic water permeability (Pf) was 570 microns/s and was inhibited 85-90% by 0.6 mM HgCl2; proteinase treatment did not affect Pf or the HgCl2 inhibition. In EV, NEM-sensitive H+ accumulation and ATPase activity were inhibited by greater than 95%. Pf (140 microns/s) and HgCl2 inhibition (75-85%) were not influenced by proteinase treatment. SDS-PAGE showed selective digestion of multiple polypeptides by proteinases. These results confirm the presence of water channels in BBMV and EV and demonstrate selective inhibition of ATPase function and Na+/H+ exchange by proteinase digestion. The lack of effect of proteinases on water transport by mercurials. We conclude that the water channel may be a small integral membrane protein which, unlike the H(+)-ATPase and Na+/H+ exchanger, has no functionally important membrane domains that are sensitive to proteolysis. PMID:1309658

  17. Reduced Epithelial Na+/H+ Exchange Drives Gut Microbial Dysbiosis and Promotes Inflammatory Response in T Cell-Mediated Murine Colitis.

    PubMed

    Laubitz, Daniel; Harrison, Christy A; Midura-Kiela, Monica T; Ramalingam, Rajalakshmy; Larmonier, Claire B; Chase, John H; Caporaso, J Gregory; Besselsen, David G; Ghishan, Fayez K; Kiela, Pawel R

    2016-01-01

    Inflammatory bowel diseases (IBD) are associated with functional inhibition of epithelial Na+/H+ exchange. In mice, a selective disruption of NHE3 (Slc9a3), a major apical Na+/H+ exchanger, also promotes IBD-like symptoms and gut microbial dysbiosis. We hypothesized that disruption of Na+/H+ exchange is necessary for the development of dysbiosis, which promotes an exacerbated mucosal inflammatory response. Therefore, we performed a temporal analysis of gut microbiota composition, and mucosal immune response to adoptive T cell transfer was evaluated in Rag2-/- and NHE3-/-/Rag2-/- (DKO) mice with and without broad-spectrum antibiotics. Microbiome (16S profiling), colonic histology, T cell and neutrophil infiltration, mucosal inflammatory tone, and epithelial permeability were analyzed. In adoptive T cell transfer colitis model, Slc9a3 status was the most significant determinant of gut microbial community. In DKO mice, NHE3-deficiency and dysbiosis were associated with dramatically accelerated and exacerbated disease, with rapid body weight loss, increased mucosal T cell and neutrophil influx, increased mucosal cytokine expression, increased permeability, and expansion of CD25-FoxP3+ Tregs; this enhanced susceptibility was alleviated by oral broad-spectrum antibiotics. Based on these results and our previous work, we postulate that epithelial electrolyte homeostasis is an important modulator in the progression of colitis, acting through remodeling of the gut microbial community. PMID:27050757

  18. The Na+/H+ Exchanger NHE6 Modulates Endosomal pH to Control Processing of Amyloid Precursor Protein in a Cell Culture Model of Alzheimer Disease*

    PubMed Central

    Prasad, Hari; Rao, Rajini

    2015-01-01

    Early intervention may be key to safe and effective therapies in patients with Alzheimer disease. Endosomal dysfunction is an early step in neurodegeneration. Endosomes are a major site of production of Aβ peptide from the processing of amyloid precursor protein (APP) by clipping enzymes (β- and γ-secretases). The β-secretase enzyme BACE1 requires acidic lumen pH for optimum function, and acid pH promotes Aβ aggregation. The Na+/H+ exchanger NHE6 provides a leak pathway for protons, limiting luminal acidification by proton pumps. Like APP, NHE6 expression was induced upon differentiation of SH-SY5Y neuroblastoma cells and localized to an endosomal compartment. Therefore, we investigated whether NHE6 expression altered APP localization and processing in a stably transfected cell culture model of human APP expression. We show that co-expression with NHE6 or treatment with the Na+/H+ ionophore monensin shifted APP away from the trans-Golgi network into early and recycling endosomes in HEK293 cells. NHE6 alkalinized the endosomal lumen, similar to monensin, and significantly attenuated APP processing and Aβ secretion. In contrast, Aβ production was elevated upon NHE6 knockdown. We show that NHE6 transcript and protein levels are lowered in Alzheimer brains relative to control. These findings, taken together with emerging genetic evidence linking endosomal Na+/H+ exchangers with Alzheimer disease, suggest that proton leak pathways may regulate Aβ generation and contribute to disease etiology. PMID:25561733

  19. Reduced Epithelial Na+/H+ Exchange Drives Gut Microbial Dysbiosis and Promotes Inflammatory Response in T Cell-Mediated Murine Colitis

    PubMed Central

    Midura-Kiela, Monica T.; Ramalingam, Rajalakshmy; Larmonier, Claire B.; Chase, John H.; Caporaso, J. Gregory; Besselsen, David G.; Ghishan, Fayez K.; Kiela, Pawel R.

    2016-01-01

    Inflammatory bowel diseases (IBD) are associated with functional inhibition of epithelial Na+/H+ exchange. In mice, a selective disruption of NHE3 (Slc9a3), a major apical Na+/H+ exchanger, also promotes IBD-like symptoms and gut microbial dysbiosis. We hypothesized that disruption of Na+/H+ exchange is necessary for the development of dysbiosis, which promotes an exacerbated mucosal inflammatory response. Therefore, we performed a temporal analysis of gut microbiota composition, and mucosal immune response to adoptive T cell transfer was evaluated in Rag2-/- and NHE3-/-/Rag2-/- (DKO) mice with and without broad-spectrum antibiotics. Microbiome (16S profiling), colonic histology, T cell and neutrophil infiltration, mucosal inflammatory tone, and epithelial permeability were analyzed. In adoptive T cell transfer colitis model, Slc9a3 status was the most significant determinant of gut microbial community. In DKO mice, NHE3-deficiency and dysbiosis were associated with dramatically accelerated and exacerbated disease, with rapid body weight loss, increased mucosal T cell and neutrophil influx, increased mucosal cytokine expression, increased permeability, and expansion of CD25-FoxP3+ Tregs; this enhanced susceptibility was alleviated by oral broad-spectrum antibiotics. Based on these results and our previous work, we postulate that epithelial electrolyte homeostasis is an important modulator in the progression of colitis, acting through remodeling of the gut microbial community. PMID:27050757

  20. Fast reconstruction of a bounded ultrasonic beam using acoustically induced piezo-luminescence

    SciTech Connect

    Kersemans, Mathias Lammens, Nicolas; Degrieck, Joris; Van Paepegem, Wim; Smet, Philippe F.

    2015-12-07

    We report on the conversion of ultrasound into light by the process of piezo-luminescence in epoxy with embedded BaSi{sub 2}O{sub 2}N{sub 2}:Eu as active component. We exploit this acoustically induced piezo-luminescence to visualize several cross-sectional slices of the radiation field of an ultrasonic piston transducer (f = 3.3 MHz) in both the near-field and the far-field. Simply combining multiple slices then leads to a fast representation of the 3D spatial radiation field. We have confronted the luminescent results with both scanning hydrophone experiments and digital acoustic holography results, and obtained a good correlation between the different approaches.

  1. Characterization of cytoskeletal protein 4.1R interaction with Na+/H+ exchanger isoform 1 (NHE1)

    PubMed Central

    Nunomura, Wataru; Denker, Sheryl P.; Barber, Diane L.; Takakuwa, Yuichi; Gascard, Philippe

    2015-01-01

    Na+/H+ exchanger isoform 1 (NHE1) has been reported to be hyperactive in 4.1R-null erythrocytes (Rivera A et al., Am J Physiol Cell Physiol, 291, C880–886, 2006), supporting a functional interaction between NHE1 and 4.1R. Here we demonstrate that 4.1R binds directly to the cytoplasmic domain of NHE1 (NHE1cd) through the interaction of an EED motif in 4.1R FERM (Four.one/Ezrin/Radixin/Moesin) domain with two clusters of basic amino acids, K519R and R556FNKKYVKK, in NHE1cd, previously shown to mediate phosphatidylinositol 4,5-bisphosphate (PIP2) binding (Aharonovitz et al. J. Cell. Biol., 150, 213–224, 2000). The affinity of this interaction (Kd=100–200nM) is reduced in hypertonic and acidic conditions, demonstrating that this interaction is of electrostatic nature. The binding affinity is also reduced upon binding of Ca2+-saturated calmodulin (Ca2+/CaM) to 4.1R FERM domain. We propose that 4.1R regulates NHE1 activity through a direct protein-protein interaction that can be modulated by intracellular pH and Na+ and Ca2+ concentrations. PMID:22731252

  2. Correlating structure, dynamics, and function in transmembrane segment VII of the Na+/H+ exchanger isoform 1.

    PubMed

    Reddy, Tyler; Li, Xiuju; Fliegel, Larry; Sykes, Brian D; Rainey, Jan K

    2010-02-01

    We place (15)N nuclear magnetic resonance relaxation analysis and functional mutagenesis studies in the context of our previous structural and mutagenesis work to correlate structure, dynamics and function for the seventh transmembrane segment of the human Na(+)/H(+) exchanger isoform 1. Although G261-S263 was previously identified as an interruption point in the helical structure of this isolated transmembrane peptide in dodecylphosphocholine micelles, and rapid conformational exchange was implicated in the NOE measurements, the six (15)N labelled residues examined in this study all have similar dynamics on the ps-ns time scale. A mathematical model incorporating chemical exchange is the best fit for residues G261, L264, and A268. This implies that a segment of residues from G261 to A268 samples different conformations on the mus-ms time scale. Chemical exchange on an intermediate time scale is consistent with an alternating-access cycle where E262 is bent away from the cytosol during proton translocation by the exchanger. The functional importance of chemical exchange at G261-A268 is corroborated by the abrogated activity of the full-length exchanger with the bulky and restricting Ile substitutions F260I, G261I, E262I, S263I, and A268I. PMID:19595986

  3. A mechanism for the activation of the Na/H exchanger NHE-1 by cytoplasmic acidification and mitogens

    PubMed Central

    Lacroix, Jérôme; Poët, Mallorie; Maehrel, Céline; Counillon, Laurent

    2004-01-01

    Eukaryotic cells constantly have to fight against internal acidification. In mammals, this task is mainly performed by the ubiquitously expressed electroneutral Na+/H+ exchanger NHE-1, which activates in a cooperative manner when cells become acidic. Despite its biological importance, the mechanism of this activation is still poorly understood, the most commonly accepted hypothesis being the existence of a proton-sensor site on the internal face of the transporter. This work uncovers mutations that lead to a nonallosteric form of the exchanger and demonstrates that NHE-1 activation is best described by a Monod–Wyman–Changeux concerted mechanism for a dimeric transporter. During intracellular acidification, a low-affinity form of NHE-1 is converted into a form possessing a higher affinity for intracellular protons, with no requirement for an additional proton-sensor site on the protein. This new mechanism also explains the activation of the exchanger by growth signals, which shift the equilibrium towards the high-affinity form. PMID:14710192

  4. The PDZ Protein Na+/H+ Exchanger Regulatory Factor-1 (NHERF1) Regulates Planar Cell Polarity and Motile Cilia Organization

    PubMed Central

    Stolz, Donna B.; Tsang, Michael; Friedman, Peter A.; Romero, Guillermo

    2016-01-01

    Directional flow of the cerebrospinal fluid requires coordinated movement of the motile cilia of the ependymal epithelium that lines the cerebral ventricles. Here we report that mice lacking the Na+/H+ Exchanger Regulatory Factor 1 (NHERF1/Slc9a3r1, also known as EBP50) develop profound communicating hydrocephalus associated with fewer and disorganized ependymal cilia. Knockdown of NHERF1/slc9a3r1 in zebrafish embryos also causes severe hydrocephalus of the hindbrain and impaired ciliogenesis in the otic vesicle. Ultrastructural analysis did not reveal defects in the shape or organization of individual cilia. Similar phenotypes have been described in animals with deficiencies in Wnt signaling and the Planar Cell Polarity (PCP) pathway. We show that NHERF1 binds the PCP core genes Frizzled (Fzd) and Vangl. We further show that NHERF1 assembles a ternary complex with Fzd4 and Vangl2 and promotes translocation of Vangl2 to the plasma membrane, in particular to the apical surface of ependymal cells. Taken together, these results strongly support an important role for NHERF1 in the regulation of PCP signaling and the development of functional motile cilia. PMID:27055101

  5. Endosomal pH in neuronal signaling and synaptic transmission: role of Na+/H+ exchanger NHE5

    PubMed Central

    Diering, Graham H.; Numata, Masayuki

    2013-01-01

    Neuronal precursor cells extend multiple neurites during development, one of which extends to form an axon whereas others develop into dendrites. Chemical stimulation of N-methyl D-aspartate (NMDA) receptor in fully-differentiated neurons induces projection of dendritic spines, small spikes protruding from dendrites, thereby establishing another layer of polarity within the dendrite. Neuron-enriched Na+/H+ exchanger NHE5 contributes to both neurite growth and dendritic spine formation. In resting neurons and neuro-endocrine cells, neuron-enriched NHE5 is predominantly associated with recycling endosomes where it colocalizes with nerve growth factor (NGF) receptor TrkA. NHE5 potently acidifies the lumen of TrkA-positive recycling endosomes and regulates cell-surface targeting of TrkA, whereas chemical stimulation of NMDA receptors rapidly recruits NHE5 to dendritic spines, alkalinizes dendrites and down-regulates the dendritic spine formation. Possible roles of NHE5 in neuronal signaling via proton movement in subcellular compartments are discussed. PMID:24454292

  6. Functional analyses of a putative plasma membrane Na+/H+ antiporter gene isolated from salt tolerant Helianthus tuberosus.

    PubMed

    Li, Qing; Tang, Zhong; Hu, Yibing; Yu, Ling; Liu, Zhaopu; Xu, Guohua

    2014-08-01

    Jerusalem artichokes (Helianthus tuberosus L.) can tolerate relatively higher salinity, drought and heat stress. In this paper, we report the cloning of a Salt Overly Sensitive 1 (SOS1) gene encoding a plasma membrane Na(+)/H(+) antiporter from a highly salt-tolerant genotype of H. tuberosus, NY1, named HtSOS1 and characterization of its function in yeast and rice. The amino acid sequence of HtSOS1 showed 83.4% identity with the previously isolated SOS1 gene from the Chrysanthemum crassum. The mRNA level in the leaves of H. tuberosus was significantly up-regulated by presence of high concentrations of NaCl. Localization analysis using rice protoplast expression showed that the protein encoded by HtSOS1 was located in the plasma membrane. HtSOS1 partially suppressed the salt sensitive phenotypes of a salt sensitive yeast strain. In comparison with wild type (Oryza sativa L., ssp. Japonica. cv. Nipponbare), the transgenic rice expressed with HtSOS1 could exclude more Na(+) and accumulate more K(+). Expression of HtSOS1 decreased Na(+) content much larger in the shoot than in the roots, resulting in more water content in the transgenic rice than WT. These data suggested that HtSOS1 may be useful in transgenic approaches to improving the salinity tolerance of glycophyte. PMID:24771143

  7. Mislocalized Scaffolding by the Na-H Exchanger NHE1 Dominantly Inhibits Fibronectin Production and TGF-β Activation

    PubMed Central

    Karydis, Anastasios; Jimenez-Vidal, Maite; Denker, Sheryl P.

    2009-01-01

    Secretion and assembly of the extracellular matrix protein fibronectin regulates a number of normal cell and tissue functions and is dysregulated in disease states such as fibrosis, diabetes, and cancer. We found that mislocalized scaffolding by the plasma membrane Na-H exchanger NHE1 suppresses fibronectin expression, secretion, and assembly. In fibroblasts, wild-type NHE1 localizes to the distal margin of membrane protrusions or lamellipodia but a mutant NHE1-KRA2 lacking binding sites for PI(4,5)P2 and the ERM proteins ezrin, radixin, and moesin is mislocalized and found uniformly along the plasma membrane. Although NHE1 regulates intracellular pH homeostasis, fibronectin production is not regulated by changes in intracellular pH, nor is it attenuated in NHE1-deficient cells, indicating fibronectin expression is independent of NHE1 activity. However, fibronectin production is nearly absent in cells expressing NHE1-KRA2 because scaffolding by NHE1 is mislocalized. Additionally, secretion of active but not latent TGF-β is reduced and exogenous TGF-β restores fibronectin secretion and assembly. Our data indicate that scaffolding by NHE1-KRA2 dominantly suppresses fibronectin synthesis and TGF-β activation, and they suggest that NHE1-KRA2 can be used for obtaining a mechanistic understanding of how fibronectin production is regulated and speculatively for therapeutic control of dysregulated production in pathological conditions. PMID:19225158

  8. A NOVEL AMILORIDE SENSITIVE H+ TRANSPORT PATHWAY MEDIATES ENHANCED SUPEROXIDE PRODUCTION IN THICK ASCENDING LIMB OF SALT-SENSITIVE RATS, NOT Na+/H+ EXCHANGE

    PubMed Central

    O’Connor, Paul M.; Lu, Limin; Liang, Mingyu; Cowley, Allen W.

    2009-01-01

    It has previously been reported that H+ efflux via Na+/H+ exchange stimulates NAD(P)H oxidase dependent O2 − production in medullary thick ascending limb. We have recently demonstrated that N-methyl-amiloride sensitive O2 − production is enhanced in thick ascending limb of salt-sensitive SS rats suggesting that H+ efflux through Na+/H+ exchangers may promote renal oxidative stress and the development of hypertension in these animals. In the current study we demonstrate, using selective and potent inhibitors, that inhibition of Na+/H+ exchange does not mediate the ability of N-methyl-amiloride to inhibit thick ascending limb O2 − production. To determine the mechanism of action of N-methyl-amiloride, we examined H+ efflux and O2 − production in SS and SS.13BN thick ascending limb of pre-hypertensive, 0.4% NaCl fed rats. Tissue strips containing medullary thick ascending limb were isolated from male SS and salt-resistant consomic SS.13BN rats, loaded with either DHE or BCECF, and imaged in a heated tissue bath. In Na+ replete media, activation of Na+/H+ exchange using an NH4Cl prepulse did not stimulate thick ascending limb O2 −production. In Na+ free media containing BaCl2 in which Na+/H+ activity was inhibited, a NH4Cl pre-pulse stimulated mTAL O2 −. This response was enhanced in mTAL of SS rats (slope ΔEth/ΔDHE=0.029±0.004) compared to SS.13BN rats (slope=0.010±0.004; p<0.04) and could be inhibited by N-methyl-amiloride (slope=0.005±0.002 & 0.006±0.002 for SS and SS.13BN, respectively). We conclude that only H+ efflux through a specific, as yet unidentified, amiloride-sensitive H+ channel promotes O2 − production in medullary thick ascending limb, and that this channel is up-regulated in SS rats. PMID:19564541

  9. Measurement of rabbit eardrum vibration through stroboscopic digital holography

    SciTech Connect

    De Greef, Daniël; Dirckx, Joris J. J.

    2014-05-27

    In this work, we present a setup for high-power single shot stroboscopic digital holography and demonstrate it in an application on rabbit eardrum vibration measurement. The setup is able to make full-field time-resolved measurements of vibrating surfaces with a precision in the nanometer range in a broad frequency range. The height displacement of the measured object is visualized over the entire surface as a function of time. Vibration magnitude and phase maps can be extracted from these data, the latter proving to be very useful to reveal phase delays across the surface. Such deviations from modal motion indicate energy losses due to internal damping, in contrast to purely elastic mechanics. This is of great interest in middle ear mechanics and finite element modelling. In our setup, short laser pulses are fired at selected instants within the surface vibration period and are recorded by a CCD camera. The timing of the pulses and the exposure of the camera are synchronized to the vibration phase by a microprocessor. The high-power frequency-doubled Nd:YAG laser produces pulses containing up to 5 mJ of energy, which is amply sufficient to record single-shot holograms. As the laser pulse length is 8 ns and the smallest time step of the trigger electronics is 1 μs, vibration measurements of frequencies up to 250 kHz are achievable through this method, provided that the maximum vibration amplitude exceeds a few nanometers. In our application, middle ear mechanics, measuring frequencies extend from 5 Hz to 20 kHz. The experimental setup will be presented, as well as results of measurements on a stretched circular rubber membrane and a rabbit's eardrum. Two of the challenges when measuring biological tissues, such as the eardrum, are low reflectivity and fast dehydration. To increase reflectivity, a coating is applied and to counteract the undesirable effects of tissue dehydration, the measurement setup and software have been optimized for speed without compromising

  10. Aspects of holography in Lorentz-violating gravity

    NASA Astrophysics Data System (ADS)

    Bhattacharyya, Jishnu

    The study of black hole thermodynamics has provided deep insights into the nature of quantum gravity. In particular, it is almost universally accepted nowadays that 'quantum gravity is holographic', so that the maximum amount of information allowed in a given region of spacetime is proportional to the area of the boundary rather than the volume of the region. This is against the conventional notion of extensivity of information (entropy), but in accord with Bekenstein's proposal on the proportionality of black hole entropy to its event horizon area. Due to the very definition of black holes, however, conventional black hole thermodynamics rely on the standard causal structure of general relativity dictated by local light cones. It may therefore seem that the notion of holography is ultimately tied to the same causal structure, and hence, on the equivalence principle and local Lorentz invariance. The goal of this dissertation is to re-evaluate this generally accepted wisdom. To that end, we consider a modified gravity theory called Einstein-aether theory. This theory violates local Lorentz invariance and therefore destroys the notion of a universal light cone. Yet, in the low energy limit, it possesses static and spherically symmetric solutions with 'universal horizons'---spacelike hypersurfaces that are causal boundaries between an interior region and asymptotic spatial infinity. In other words, this theory admits black hole solutions but with very different causal structures. In this dissertation, we investigate into how much of black hole thermodynamics carry over in this new setting. We consider static and spherically symmetric black hole solutions of Einstein-aether theory and establish the Smarr formula and the first law of black hole mechanics for them, with the relevant horizon now the universal horizon. We also consider tunneling of a scalar 'test' field through the universal horizon, and show that the latter radiates as a blackbody at a fixed temperature

  11. Measurement of rabbit eardrum vibration through stroboscopic digital holography

    NASA Astrophysics Data System (ADS)

    De Greef, Daniël; Dirckx, Joris J. J.

    2014-05-01

    In this work, we present a setup for high-power single shot stroboscopic digital holography and demonstrate it in an application on rabbit eardrum vibration measurement. The setup is able to make full-field time-resolved measurements of vibrating surfaces with a precision in the nanometer range in a broad frequency range. The height displacement of the measured object is visualized over the entire surface as a function of time. Vibration magnitude and phase maps can be extracted from these data, the latter proving to be very useful to reveal phase delays across the surface. Such deviations from modal motion indicate energy losses due to internal damping, in contrast to purely elastic mechanics. This is of great interest in middle ear mechanics and finite element modelling. In our setup, short laser pulses are fired at selected instants within the surface vibration period and are recorded by a CCD camera. The timing of the pulses and the exposure of the camera are synchronized to the vibration phase by a microprocessor. The high-power frequency-doubled Nd:YAG laser produces pulses containing up to 5 mJ of energy, which is amply sufficient to record single-shot holograms. As the laser pulse length is 8 ns and the smallest time step of the trigger electronics is 1 μs, vibration measurements of frequencies up to 250 kHz are achievable through this method, provided that the maximum vibration amplitude exceeds a few nanometers. In our application, middle ear mechanics, measuring frequencies extend from 5 Hz to 20 kHz. The experimental setup will be presented, as well as results of measurements on a stretched circular rubber membrane and a rabbit's eardrum. Two of the challenges when measuring biological tissues, such as the eardrum, are low reflectivity and fast dehydration. To increase reflectivity, a coating is applied and to counteract the undesirable effects of tissue dehydration, the measurement setup and software have been optimized for speed without compromising

  12. AST Launch Vehicle Acoustics

    NASA Technical Reports Server (NTRS)

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

    2015-01-01

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

  13. Acoustic Translation of an Acoustically Levitated Sample

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B.; Allen, J. L.

    1986-01-01

    Acoustic-levitation apparatus uses only one acoustic mode to move sample from one region of chamber to another. Sample heated and cooled quickly by translation between hot and cold regions of levitation chamber. Levitated sample is raised into furnace region by raising plunger. Frequency of sound produced by transducers adjusted by feedback system to maintain (102) resonant mode, which levitates sample midway between transducers and plunger regardless of plunger position.

  14. Dark-field electron holography for the measurement of geometric phase.

    PubMed

    Hÿtch, M J; Houdellier, F; Hüe, F; Snoeck, E

    2011-07-01

    The genesis, theoretical basis and practical application of the new electron holographic dark-field technique for mapping strain in nanostructures are presented. The development places geometric phase within a unified theoretical framework for phase measurements by electron holography. The total phase of the transmitted and diffracted beams is described as a sum of four contributions: crystalline, electrostatic, magnetic and geometric. Each contribution is outlined briefly and leads to the proposal to measure geometric phase by dark-field electron holography (DFEH). The experimental conditions, phase reconstruction and analysis are detailed for off-axis electron holography using examples from the field of semiconductors. A method for correcting for thickness variations will be proposed and demonstrated using the phase from the corresponding bright-field electron hologram. PMID:21864773

  15. Holography as a principle in quantum gravity?-Some historical and systematic observations

    NASA Astrophysics Data System (ADS)

    Sieroka, Norman; Mielke, Eckehard W.

    2014-05-01

    Holography is a fruitful concept in modern physics. However, there is no generally accepted definition of the term, and its significance, especially as a guiding principle in quantum gravity, is rather uncertain. The present paper critically evaluates variants of the holographic principle from two perspectives: (i) their relevance in contemporary approaches to quantum gravity and in closely related areas; (ii) their historical forerunners in the early twentieth century and the role played by past and present concepts of holography in attempts to unify physics. By combining these two perspectives a certain depth of focus is gained which allows us to draw some tentative conclusions about what might be reasonable aspirations and prospects for holography in quantum gravity. By the same token, we will have a brief and critical look at wider philosophical interpretations of the term.

  16. Image authentication via sparsity-based phase-shifting digital holography

    NASA Astrophysics Data System (ADS)

    Chen, Wen; Chen, Xudong

    2015-03-01

    Digital holography has been widely studied in recent years, and a number of applications have been demonstrated. In this paper, we demonstrate that sparsity-based phase-shifting digital holography can be applied for image authentication. In phase-shifting digital holography, the holograms are sequentially recorded. Only small parts of each hologram are available for numerical reconstruction. It is found that nonlinear correlation algorithm can be applied to simply authenticate the reconstructed object. The results illustrate that the recovered image can be correctly verified. In the developed system, the recorded holograms are highly compressed which can facilitate data storage or transmission, and one simple authentication strategy has been established instead of applying relatively complex algorithms (such as compressive sensing) to recover the object.

  17. Coded aperture correlation holography-a new type of incoherent digital holograms.

    PubMed

    Vijayakumar, A; Kashter, Yuval; Kelner, Roy; Rosen, Joseph

    2016-05-30

    We propose and demonstrate a new concept of incoherent digital holography termed coded aperture correlation holography (COACH). In COACH, the hologram of an object is formed by the interference of light diffracted from the object, with light diffracted from the same object, but that passes through a coded phase mask (CPM). Another hologram is recorded for a point object, under identical conditions and with the same CPM. This hologram is called the point spread function (PSF) hologram. The reconstructed image is obtained by correlating the object hologram with the PSF hologram. The image reconstruction of multiplane object using COACH was compared with that of other equivalent imaging systems, and has been found to possess a higher axial resolution compared to Fresnel incoherent correlation holography. PMID:27410157

  18. Photorefractive and computational holography in the experimental generation of Airy beams

    NASA Astrophysics Data System (ADS)

    Suarez, Rafael A. B.; Vieira, Tarcio A.; Yepes, Indira S. V.; Gesualdi, Marcos R. R.

    2016-05-01

    In this paper, we present the experimental generation of Airy beams via computational and photorefractive holography. Experimental generation of Airy beams using conventional optical components presents several difficulties and a practically infeasible. Thus, the optical generation of Airy beams has been made from the optical reconstruction of a computer generated hologram implemented by a spatial light modulator. In the photorefractive holography technique, being used for the first time to our knowledge, the hologram of an Airy beam is constructed (recorded) and reconstructed (read) optically in a nonlinear photorefractive medium. The Airy beam experimental realization was made by a setup of computational and photorefractive holography using a photorefractive Bi12 TiO20 crystal as holographic recording medium. Airy beams and Airy beam arrays were obtained experimentally in accordance with the predicted theory; with excellent prospects for applications in optical trapping and optical communications systems.

  19. Imaging live humans through smoke and flames using far-infrared digital holography.

    PubMed

    Locatelli, M; Pugliese, E; Paturzo, M; Bianco, V; Finizio, A; Pelagotti, A; Poggi, P; Miccio, L; Meucci, R; Ferraro, P

    2013-03-11

    The ability to see behind flames is a key challenge for the industrial field and particularly for the safety field. Development of new technologies to detect live people through smoke and flames in fire scenes is an extremely desirable goal since it can save human lives. The latest technologies, including equipment adopted by fire departments, use infrared bolometers for infrared digital cameras that allow users to see through smoke. However, such detectors are blinded by flame-emitted radiation. Here we show a completely different approach that makes use of lensless digital holography technology in the infrared range for successful imaging through smoke and flames. Notably, we demonstrate that digital holography with a cw laser allows the recording of dynamic human-size targets. In this work, easy detection of live, moving people is achieved through both smoke and flames, thus demonstrating the capability of digital holography at 10.6 μm. PMID:23482109

  20. Study of 3D remote sensing system based on optical scanning holography

    NASA Astrophysics Data System (ADS)

    Zhao, Shihu; Yan, Lei

    2009-06-01

    High-precision and real-time remote sensing imaging system is an important part of remote sensing development. Holography is a method of wave front record and recovery which was presented by Dennis Gabor. As a new kind of holography techniques, Optical scanning holography (OSH) and remote sensing imaging are intended to be combined together and applied in acquisition and interference measurement of remote sensing. The key principles and applicability of OSH are studied and the mathematic relation between Fresnel Zone Plate number, numerical aperture and object distance was deduced, which are proved to be feasible for OSH to apply in large scale remote sensing. At last, a new three-dimensional reflected OSH remote sensing imaging system is designed with the combination of scanning technique to record hologram patterns of large scale remote sensing scenes. This scheme is helpful for expanding OSH technique to remote sensing in future.

  1. Binary optoacoustic holography with a spatial light modulator

    SciTech Connect

    Meyer, A.; Gspan, S.; Bernet, S.; Ritsch-Marte, M.

    2004-11-15

    A purely optical method to generate and to steer an ultrasonic beam is presented. The generation of the ultrasonic beam in the kilohertz to megahertz regime is achieved by using the optoacoustic effect in a layer attached to the surface of a water tank, which absorbs time-modulated laser pulses. In order to tailor the emitted acoustic wave, diffractive optics concepts are applied to acoustics. To this end, the laser light intensity distribution at the absorbing surface is controlled by sending a computer-calculated pattern to a transmissive high-resolution liquid-crystal display in the beam path. This results in an acoustic analog to the 'diffractive optical elements' in laser optics, with the emitted ultrasonic wave emerging in a predetermined way. The proof of principle is demonstrated for examples such as phase gratings and binary Fresnel lenses. The optoacoustic ultrasound generation with holographic diffractive steering is a flexible method with the potential of new applications in ultrasound diagnostics.

  2. Binary optoacoustic holography with a spatial light modulator

    NASA Astrophysics Data System (ADS)

    Meyer, A.; Gspan, S.; Bernet, S.; Ritsch-Marte, M.

    2004-11-01

    A purely optical method to generate and to steer an ultrasonic beam is presented. The generation of the ultrasonic beam in the kilohertz to megahertz regime is achieved by using the optoacoustic effect in a layer attached to the surface of a water tank, which absorbs time-modulated laser pulses. In order to tailor the emitted acoustic wave, diffractive optics concepts are applied to acoustics. To this end, the laser light intensity distribution at the absorbing surface is controlled by sending a computer-calculated pattern to a transmissive high-resolution liquid-crystal display in the beam path. This results in an acoustic analog to the "diffractive optical elements" in laser optics, with the emitted ultrasonic wave emerging in a predetermined way. The proof of principle is demonstrated for examples such as phase gratings and binary Fresnel lenses. The optoacoustic ultrasound generation with holographic diffractive steering is a flexible method with the potential of new applications in ultrasound diagnostics.

  3. Nonlinear Acoustics in Fluids

    NASA Astrophysics Data System (ADS)

    Lauterborn, Werner; Kurz, Thomas; Akhatov, Iskander

    At high sound intensities or long propagation distances at in fluids sufficiently low damping acoustic phenomena become nonlinear. This chapter focuses on nonlinear acoustic wave properties in gases and liquids. The origin of nonlinearity, equations of state, simple nonlinear waves, nonlinear acoustic wave equations, shock-wave formation, and interaction of waves are presented and discussed. Tables are given for the nonlinearity parameter B/A for water and a range of organic liquids, liquid metals and gases. Acoustic cavitation with its nonlinear bubble oscillations, pattern formation and sonoluminescence (light from sound) are modern examples of nonlinear acoustics. The language of nonlinear dynamics needed for understanding chaotic dynamics and acoustic chaotic systems is introduced.

  4. Off-axis illumination direct-to-digital holography

    DOEpatents

    Thomas, Clarence E.; Price, Jeffery R.; Voelkl, Edgar; Hanson, Gregory R.

    2004-06-08

    Systems and methods are described for off-axis illumination direct-to-digital holography. A method of recording an off-axis illuminated spatially heterodyne hologram including spatially heterodyne fringes for Fourier analysis, includes: reflecting a reference beam from a reference mirror at a non-normal angle; reflecting an object beam from an object at an angle with respect to an optical axis defined by a focusing lens; focusing the reference beam and the object beam at a focal plane of a digital recorder to form the off-axis illuminated spatially heterodyne hologram including spatially heterodyne fringes for Fourier analysis; digitally recording the off-axis illuminated spatially heterodyne hologram including spatially heterodyne fringes for Fourier analysis; Fourier analyzing the recorded off-axis illuminated spatially heterodyne hologram including spatially heterodyne fringes by transforming axes of the recorded off-axis illuminated spatially heterodyne hologram including spatially heterodyne fringes in Fourier space to sit on top of a heterodyne carrier frequency defined as an angle between the reference beam and the object beam; applying a digital filter to cut off signals around an original origin; and then performing an inverse Fourier transform.

  5. Light-Front Holography and Hadronization at the Amplitude Level

    SciTech Connect

    Brodsky, Stanley J.; de Teramond, Guy; Shrock, Robert

    2008-07-25

    The correspondence between theories in anti-de Sitter space and conformal field theories in physical space-time leads to an analytic, semiclassical model for strongly-coupled QCD which has scale invariance at short distances and color confinement at large distances. Light-front holography is a remarkable feature of AdS/CFT: it allows hadronic amplitudes in the AdS fifth dimension to be mapped to frame-independent light-front wavefunctions of hadrons in physical space-time, thus providing a relativistic description of hadrons at the amplitude level. Some novel features of QCD are discussed, including the consequences of confinement for quark and gluon condensates and the behavior of the QCD coupling in the infrared. We suggest that the spatial support of QCD condensates is restricted to the interior of hadrons, since they arise due to the interactions of confined quarks and gluons. Chiral symmetry is thus broken in a limited domain of size 1=m{sub {pi}} in analogy to the limited physical extent of superconductor phases. A new method for computing the hadronization of quark and gluon jets at the amplitude level, an event amplitude generator, is outlined.

  6. Fresnelets: new multiresolution wavelet bases for digital holography.

    PubMed

    Liebling, Michael; Blu, Thierry; Unser, Michael

    2003-01-01

    We propose a construction of new wavelet-like bases that are well suited for the reconstruction and processing of optically generated Fresnel holograms recorded on CCD-arrays. The starting point is a wavelet basis of L2 to which we apply a unitary Fresnel transform. The transformed basis functions are shift-invariant on a level-by-level basis but their multiresolution properties are governed by the special form that the dilation operator takes in the Fresnel domain. We derive a Heisenberg-like uncertainty relation that relates the localization of Fresnelets with that of their associated wavelet basis. According to this criterion, the optimal functions for digital hologram processing turn out to be Gabor functions, bringing together two separate aspects of the holography inventor's work. We give the explicit expression of orthogonal and semi-orthogonal Fresnelet bases corresponding to polynomial spline wavelets. This special choice of Fresnelets is motivated by their near-optimal localization properties and their approximation characteristics. We then present an efficient multiresolution Fresnel transform algorithm, the Fresnelet transform. This algorithm allows for the reconstruction (backpropagation) of complex scalar waves at several user-defined, wavelength-independent resolutions. Furthermore, when reconstructing numerical holograms, the subband decomposition of the Fresnelet transform naturally separates the image to reconstruct from the unwanted zero-order and twin image terms. This greatly facilitates their suppression. We show results of experiments carried out on both synthetic (simulated) data sets as well as on digitally acquired holograms. PMID:18237877

  7. Light-Front Holography and AdS/QCD Correspondence

    SciTech Connect

    Brodsky, Stanley J.; de Teramond, Guy F.

    2008-04-23

    Light-Front Holography is a remarkable consequence of the correspondence between string theory in AdS space and conformal field theories in physical-space time. It allows string modes {Phi}(z) in the AdS fifth dimension to be precisely mapped to the light-front wavefunctions of hadrons in terms of a specific light-front impact variable {zeta} which measures the separation of the quark and gluonic constituents within the hadron. This mapping was originally obtained by matching the exact expression for electromagnetic current matrix elements in AdS space with the corresponding exact expression for the current matrix element using light-front theory in physical space-time. More recently we have shown that one obtains the identical holographic mapping using matrix elements of the energy-momentum tensor, thus providing an important consistency test and verification of holographic mapping from AdS to physical observables defined on the light-front. The resulting light-front Schrodinger equations predicted from AdS/QCD give a good representation of the observed meson and baryon spectra and give excellent phenomenological predictions for amplitudes such as electromagnetic form factors and decay constants.

  8. Light-Front Holography and Hadronization at the Amplitude Level

    SciTech Connect

    Brodsky, Stanley J.; Teramond, Guy F. de; Shrock, Robert

    2008-10-13

    The correspondence between theories in anti-de Sitter space and conformal field theories in physical space-time leads to an analytic, semiclassical model for strongly-coupled QCD which has scale invariance at short distances and color confinement at large distances. Light-front holography is a remarkable feature of AdS/CFT: it allows hadronic amplitudes in the AdS fifth dimension to be mapped to frame-independent light-front wavefunctions of hadrons in physical space-time, thus providing a relativistic description of hadrons at the amplitude level. Some novel features of QCD are discussed, including the consequences of confinement for quark and gluon condensates and the behavior of the QCD coupling in the infrared. We suggest that the spatial support of QCD condensates is restricted to the interior of hadrons, since they arise due to the interactions of confined quarks and gluons. Chiral symmetry is thus broken in a limited domain of size 1/m{sub {pi}}, in analogy to the limited physical extent of superconductor phases. A new method for computing the hadronization of quark and gluon jets at the amplitude level, an event amplitude generator, is outlined.

  9. Light-Front Holography and Novel Effects in QCD

    SciTech Connect

    Brodsky, Stanley J.; Teramond, Guy F. de

    2009-04-20

    The correspondence between theories in anti-de Sitter space and conformal field theories in physical space-time leads to an analytic, semiclassical model for strongly-coupled QCD. Light-front holography allows hadronic amplitudes in the AdS fifth dimension to be mapped to frame-independent light-front wavefunctions of hadrons in physical space-time, thus providing a relativistic description of hadrons at the amplitude level. We identify the AdS coordinate z with an invariant light-front coordinate {zeta} which separates the dynamics of quark and gluon binding from the kinematics of constituent spin and internal orbital angular momentum. The result is a single-variable light-front Schroedinger equation for QCD which determines the eigenspectrum and the light-front wavefunctions of hadrons for general spin and orbital angular momentum. The mapping of electromagnetic and gravitational form factors in AdS space to their corresponding expressions in light-front theory confirms this correspondence. Some novel features of QCD are discussed, including the consequences of confinement for quark and gluon condensates and the behavior of the QCD coupling in the infrared. The distinction between static structure functions such as the probability distributions computed from the square of the light-front wavefunctions versus dynamical structure functions which include the effects of rescattering is emphasized. A new method for computing the hadronization of quark and gluon jets at the amplitude level, an event amplitude generator, is outlined.

  10. Digital Holography of Intracellular Dynamics to Probe Tissue Physiology

    PubMed Central

    Merrill, Daniel; An, Ran; Turek, John; Nolte, David D.

    2015-01-01

    Digital holography provides improved capabilities for imaging through dense tissue. Using a short-coherence source, the digital hologram recorded from backscattered light performs laser ranging that maintains fidelity of information acquired from depths much greater than possible by traditional imaging techniques. Biodynamic Imaging (BDI) is a developing technology for live-tissue imaging of up to a millimeter in depth that uses the hologram intensity fluctuations as label-free image contrast and can study tissue behavior in native microenvironments. In this paper BDI is used investigate the change in adhesion-dependent tissue response in 3D cultures. The results show that increasing density of cellular adhesions slows motion inside tissue and alters the response to cytoskeletal drugs. A clear signature of membrane fluctuations was observed in mid frequencies (0.1 – 1 Hz) that was enhanced by the application of cytochalasin-D that degrades the actin cortex inside the cell membrane. This enhancement feature is only observed in tissues that have formed adhesions, because cell pellets initially do not show this signature, but develop this signature only after incubation enables adhesions to form. PMID:25967027

  11. [Spatial and temporal control of ultrasonic fields via optoacoustic holography].

    PubMed

    Gspan, Stefan; Meyer, Alex; Bernet, Stefan; Ritsch-Marte, Monika

    2004-01-01

    The present paper presents a new method for generating ultrasound, based on the interaction of laser-induced ultrasound generation and ultrasonic holography. An ultrasonic field generated in a water tank via the optoacoustic effect is spatially and temporally controlled: In order to produce defined ultrasonic frequencies in the MHz range, the laser pulses incident on a light-absorbing layer are modulated in time using an electro-optic modulator (EOM). Additionally, a high-resolution liquid crystal spatial light modulator (SLM) is used to imprint a pre-calculated phase front to the laser beam. A computer-generated binary hologram is also displayed at the SLM. The expanded laser beam projects the corresponding pattern to the plane absorptive layer in the water tank. The projection of specific patterns for the generation of ultrasonic beams resembles the use of, diffractive optical elements" in optics. Optical ultrasound generation with holographic steering is a flexible tool with promising numerous new applications in medical and technical ultrasound diagnostics. PMID:15462419

  12. Refocusing criterion via sparsity measurements in digital holography.

    PubMed

    Memmolo, Pasquale; Paturzo, Melania; Javidi, Bahram; Netti, Paolo A; Ferraro, Pietro

    2014-08-15

    Several automatic approaches have been proposed in the past to compute the refocus distance in digital holography (DH). However most of them are based on a maximization or minimization of a suitable amplitude image contrast measure, regarded as a function of the reconstruction distance parameter. Here we show that, by using the sparsity measure coefficient regarded as a refocusing criterion in the holographic reconstruction, it is possible to recover the focus plane and, at the same time, establish the degree of sparsity of digital holograms, when samples of the diffraction Fresnel propagation integral are used as a sparse signal representation. We employ a sparsity measurement coefficient known as Gini's index thus showing for the first time, to the best of our knowledge, its application in DH, as an effective refocusing criterion. Demonstration is provided for different holographic configurations (i.e., lens and lensless apparatus) and for completely different objects (i.e., a thin pure phase microscopic object as an in vitro cell, and macroscopic puppets) preparation. PMID:25121857

  13. Computational spectral microscopy and compressive millimeter-wave holography

    NASA Astrophysics Data System (ADS)

    Fernandez, Christy Ann

    This dissertation describes three computational sensors. The first sensor is a scanning multi-spectral aperture-coded microscope containing a coded aperture spectrometer that is vertically scanned through a microscope intermediate image plane. The spectrometer aperture-code spatially encodes the object spectral data and nonnegative least squares inversion combined with a series of reconfigured two-dimensional (2D spatial-spectral) scanned measurements enables three-dimensional (3D) (x, y, lambda) object estimation. The second sensor is a coded aperture snapshot spectral imager that employs a compressive optical architecture to record a spectrally filtered projection of a 3D object data cube onto a 2D detector array. Two nonlinear and adapted TV-minimization schemes are presented for 3D (x, y, lambda) object estimation from a 2D compressed snapshot. Both sensors are interfaced to laboratory-grade microscopes and applied to fluorescence microscopy. The third sensor is a millimeter-wave holographic imaging system that is used to study the impact of 2D compressive measurement on 3D (x, y, z) data estimation. Holography is a natural compressive encoder since a 3D parabolic slice of the object band volume is recorded onto a 2D planar surface. An adapted nonlinear TV-minimization algorithm is used for 3D tomographic estimation from a 2D and a sparse 2D hologram composite. This strategy aims to reduce scan time costs associated with millimeter-wave image acquisition using a single pixel receiver.

  14. Interference and holography with femtosecond laser pulses of different colours.

    PubMed

    Odoulov, Serguey; Shumelyuk, Alexandr; Badorreck, Holger; Nolte, Stefan; Voit, Kay-Michael; Imlau, Mirco

    2015-01-01

    Interferometry and holography are two domains that are based on observation and recording of interference fringes from two light beams. While the aim of the first technique is to reveal and map the phase difference of two wave fronts, the main task of the second technique is to reconstruct one of the two recording waves via diffraction of the other wave from the recorded fringe pattern (hologram). To create fringes, mutually coherent waves from the same laser are commonly used. It is shown here that fringes can be observed and holograms can be recorded with ultrashort, sub-picosecond pulses even of different colour, generated in our experiment with two parametric amplifiers seeded, both by the same mode-locked Ti-sapphire laser. The appearance of permanent and transient gratings is confirmed by recording of an image-bearing hologram, by observation of two-beam coupling gain in a pump-probe experiment and by frequency conversion in Raman-Nath self-diffraction from a moving grating. PMID:25651807

  15. In vitro imaging of ophthalmic tissue by digital interference holography

    NASA Astrophysics Data System (ADS)

    Potcoava, Mariana C.; Kay, Christine N.; Kim, Myung K.; Richards, David W.

    2010-01-01

    We used digital interference holography (DIH) for in vitro imaging of human optic nerve head and retina. Samples of peripheral retina, macula, and optic nerve head from two formaldehyde-preserved human eyes were dissected and mounted onto slides. Holograms were captured by a monochrome CCD camera (Sony XC-ST50, with 780 × 640 pixels and pixel size of ∼9 µm). Light source was a solid-state pumped dye laser with tunable wavelength range of 560-605 nm. Using about 50 wavelengths in this band, holograms were obtained and numerically reconstructed using custom software based on NI LabView. Tomographic images were produced by superposition of holograms. Holograms of all tissue samples were obtained with a signal-to-noise ratio of approximately 50 dB. Optic nerve head characteristics (shape, diameter, cup depth, and cup width) were quantified with a few micron resolution (4.06-4.8 µm). Multiple layers were distinguishable in cross-sectional images of the macula. To our knowledge, this is the first report of DIH use to image human macular and optic nerve tissue. DIH has the potential to become a useful tool for researchers and clinicians in the diagnosis and treatment of many ocular diseases, including glaucoma and a variety of macular diseases.

  16. Photoelectron diffraction and holography: Present status and future prospects

    SciTech Connect

    Fadley, C.S. |; Thevuthasan, S.; Kaduwela, A.P.

    1993-07-01

    Photoelectron diffraction and photoelectron holography, a newly developed variant of it, can provide a rich range of information concerning surface structure. These methods are sensitive to atomic type, chemical state, and spin state. The theoretical prediction of diffraction patterns is also well developed at both the single scattering and multiple scattering levels, and quantitative fits of experiment to theory can lead to structures with accuracies in the {plus_minus}0.03 {Angstrom} range. Direct structural information can also be derived from forward scattering in scanned-angle measurements at higher energies, path length differences contained in scanned-energy data at lower energies, and holographic inversions of data sets spanning some region in angle and energy space. Diffraction can also affect average photoelectron emission depths. Circular dichroism in core-level emission can be fruitfully interpreted in terms of photoelectron diffraction theory, as can measurements with spin-resolved core-spectra, and studies of surface magnetic structures and phase transitions should be possible with these methods. Synchrotron radiation is a key element of fully utilizing these techniques.

  17. Light-Front Holography and Novel Effects in QCD

    SciTech Connect

    Brodsky, Stanley J.; de Teramond, Guy F.

    2008-12-18

    The correspondence between theories in anti-de Sitter space and conformal field theories in physical space-time leads to an analytic, semiclassical model for strongly-coupled QCD. Light-front holography allows hadronic amplitudes in the AdS fifth dimension to be mapped to frame-independent light-front wavefunctions of hadrons in physical space-time, thus providing a relativistic description of hadrons at the amplitude level. We identify the AdS coordinate z with an invariant light-front coordinate {zeta} which separates the dynamics of quark and gluon binding from the kinematics of constituent spin and internal orbital angular momentum. The result is a single-variable light-front Schroedinger equation for QCD which determines the eigenspectrum and the light-front wavefunctions of hadrons for general spin and orbital angular momentum. The mapping of electromagnetic and gravitational form factors in AdS space to their corresponding expressions in light-front theory confirms this correspondence. Some novel features of QCD are discussed, including the consequences of confinement for quark and gluon condensates and the behavior of the QCD coupling in the infrared. The distinction between static structure functions such as the probability distributions computed from the square of the light-front wavefunctions versus dynamical structure functions which include the effects of rescattering is emphasized. A new method for computing the hadronization of quark and gluon jets at the amplitude level, an event amplitude generator, is outlined.

  18. Results from the LTX High-Speed Digital Holography System

    NASA Astrophysics Data System (ADS)

    Thomas, C. E. (Tommy), Jr.; Baylor, L. R.; Combs, S. K.; Meitner, S. J.; Rasmussen, D. A.; Granstedt, E. M.; Lundberg, D. P.; Jacobson, C. M.; Majeski, R.; Kaita, R.

    2011-10-01

    A high-speed CO2 laser digital holography system (500 frames per second (FPS) at 256 x 256 pixels, 1500 FPS at 128 x 128 pixels, etc., to a maximum of 43,000 FPS at 64 x 4 pixels) has been built for high-resolution imaging of electron density on the Lithium Tokamak Experiment (LTX). The laser operates at 9.1 microns by using an Oxygen-18 isotope, and has a power output up to 20 W. A FLIR SC4000 IR camera is used to capture the digital holograms. An acousto-optic modulator (AOM) is used to ``shutter'' the laser so that effective camera integration times down to less than one microsecond are possible. The system will be used for examining profile modifications on LTX with molecular cluster injection (MCI), supersonic gas injection (SGI), and external gas puffing. Results of measurements will be presented along with a discussion of system design, including noise-reduction techniques developed during system testing and initial operation. Partial Support from USDOE Contract DE-AC02-09CH11466 and USDOE Grant DE-FG02-07ER84724 is gratefully acknowledged.

  19. Off-axis electron holography of ferromagnetic multilayer nanowires

    SciTech Connect

    Akhtari-Zavareh, Azadeh; Kavanagh, K. L.; Carignan, L. P.; Yelon, A.; Ménard, D.; Kasama, T.; Herring, R.; Dunin-Borkowski, R. E.; McCartney, M. R.

    2014-07-14

    We have used electron holography to investigate the local magnetic behavior of isolated ferromagnetic nanowires (NWs) in their remanent states. The NWs consisted of periodic magnetic layers of soft, high-saturation magnetization CoFeB alloys, and non-magnetic layers of Cu. All NWs were fabricated by pulsed-potential electrodeposition in nanoporous alumina membranes. The NW composition and layer thicknesses were measured using scanning transmission electron microscopy and energy dispersive spectroscopy. The magnetization of individual NWs depended upon the thicknesses of the layers and the direction of an external magnetic field, which had been applied in situ. When the CoFeB was thicker than the diameter (50 nm), magnetization was axial for all external field directions, while thinner layers could be randomized via a perpendicular field. In some cases, magnetization inside the wire was detected at an angle with respect to the axis of the wires. In thinner Cu/CoFeB (<10 nm each) multilayer, magnetic field vortices were detected, associated with opposing magnetization in neighbouring layers. The measured crystallinity, compositions, and layer thicknesses of individual NWs were found to be significantly different from those predicted from calibration growths based on uniform composition NWs. In particular, a significant fraction of Cu (up to 50 at. %) was present in the CoFeB layers such that the measured magnetic induction was lower than expected. These results will be used to better understand previously measured effective anisotropy fields of similar NW arrays.

  20. Holography and quantum states in elliptic de Sitter space

    NASA Astrophysics Data System (ADS)

    Halpern, Illan F.; Neiman, Yasha

    2015-12-01

    We outline a program for interpreting the higher-spin dS/CFT model in terms of physics in the causal patch of a dS observer. The proposal is formulated in "elliptic" de Sitter space d{S}_4/{Z}_2 , obtained by identifying antipodal points in dS 4. We discuss recent evidence that the higher-spin model is especially well-suited for this, since the antipodal symmetry of bulk solutions has a simple encoding on the boundary. For context, we test some other (free and interacting) theories for the same property. Next, we analyze the notion of quantum field states in the non-time-orientable d{S}_4/{Z}_2 . We compare the physics seen by different observers, with the outcome depending on whether they share an arrow of time. Finally, we implement the marriage between higher-spin holography and observers in d{S}_4/{Z}_2 , in the limit of free bulk fields. We succeed in deriving an observer's operator algebra and Hamiltonian from the CFT, but not her S-matrix. We speculate on the extension of this to interacting higher-spin theory.

  1. Vibratory strain field measurement by transverse digital holography.

    PubMed

    Stetson, Karl A

    2015-09-20

    A method is presented for measuring vibratory strain fields using phase-stepped, image-plane digital holography. An object surface is observed along its normal vector while illuminated at equal and opposite angles by two mutually coherent laser beams. One beam is phase stepped by quarter-wavelength increments between TV frames, and the resulting images are processed to yield holographic images. Object vibrations result in zero-order Bessel function fringes in the display. The second beam is modulated at the same frequency of the object vibration and is used to shift the fringes in a manner analogous to phase step interferometry. The resulting images are processed to yield a wrapped phase map, which is unwrapped and corrected for the error associated with using zero-order Bessel functions in place of cosine functions. The unwrapped images are processed to obtain the average slopes for image segments, and these slopes are multiplied by a scale factor to convert them to strain. The analysis program used here divides the field of view into five horizontal by four vertical segments, which provide a map of the vibratory strain field. PMID:26406526

  2. Holographic focal series: differences between inline and off-axis electron holography at atomic resolution

    NASA Astrophysics Data System (ADS)

    Niermann, Tore; Lehmann, Michael

    2016-05-01

    Electron holography methods allow phase information to be recovered from electron waves at atomic resolution. Focal-series reconstruction, an inline method, and off-axis holography are currently the most commonly employed techniques for this endeavor. By recording and reconstructing data from a holographic focal series of an atomically resolved GaAs crystal, we are able to reconstruct wave functions by means of both methods from the same measurement. Significant differences between these wave functions are found for low frequencies and in thicker specimen parts. Furthermore, in a rigorous treatment, we discuss how the recovered wave functions differ because of fundamental differences in the quantum mechanical measurement.

  3. 2D wave-front shaping in optical superlattices using nonlinear volume holography.

    PubMed

    Yang, Bo; Hong, Xu-Hao; Lu, Rong-Er; Yue, Yang-Yang; Zhang, Chao; Qin, Yi-Qiang; Zhu, Yong-Yuan

    2016-07-01

    Nonlinear volume holography is employed to realize arbitrary wave-front shaping during nonlinear processes with properly designed 2D optical superlattices. The concept of a nonlinear polarization wave in nonlinear volume holography is investigated. The holographic imaging of irregular patterns was performed using 2D LiTaO3 crystals with fundamental wave propagating along the spontaneous polarization direction, and the results agree well with the theoretical predictions. This Letter not only extends the application area of optical superlattices, but also offers an efficient method for wave-front shaping technology. PMID:27367067

  4. Split-illumination electron holography for improved evaluation of electrostatic potential associated with electrophotography

    SciTech Connect

    Tanigaki, Toshiaki Aizawa, Shinji; Soon Park, Hyun; Sato, Kuniaki; Akase, Zentaro; Matsuda, Tsuyoshi; Murakami, Yasukazu; Shindo, Daisuke; Kawase, Hiromitsu

    2014-03-31

    Precise evaluation of the electrostatic potential distributions of and around samples with multiple charges using electron holography has long been a problem due to unknown perturbation of the reference wave. Here, we report the first practical application of split-illumination electron holography (SIEH) to tackle this problem. This method enables the use of a non-perturbed reference wave distant from the sample. SIEH revealed the electrostatic potential distributions at interfaces of the charged particles used for development in electrophotography and should lead to dramatic improvements in electrophotography.

  5. Fabrication of submicron metallic grids with interference and phase-mask holography

    SciTech Connect

    Park, Joong-Mok; Kim, Tae-Geun; Constant, Kristen; Ho, Kai-Ming

    2011-01-25

    Complex, submicron Cu metallic mesh nanostructures are made by electrochemical deposition using polymer templates made from photoresist. The polymer templates are fabricated with photoresist using two-beam interference holography and phase mask holography with three diffracted beams. Freestanding metallic mesh structures are made in two separate electrodepositions with perpendicular photoresist grating templates. Cu mesh square nanostructures having large (52.6%) open areas are also made by single electrodeposition with a photoresist template made with a phase mask. These structures have potential as electrodes in photonic devices.

  6. Twin image removal in digital in-line holography based on iterative inter-projections

    NASA Astrophysics Data System (ADS)

    Chen, Bing Kuan; Chen, Tai-Yu; Hung, Shau Gang; Huang, Sheng-Lung; Lin, Jiunn-Yuan

    2016-06-01

    A simple and efficient phase retrieval method based on the iterative inter-projections of the recorded Fourier modulus between two effective holographic planes is developed to eliminate the twin image in digital in-line holography. The proposed algorithm converges stably in phase extraction procedures without requiring any prior knowledge or sophisticated support of the object and is applicable to lensless Gabor and Fourier holography as well as holographic microscopy with imaging lenses. Numerical and experimental results suggest that the spatial resolution enhancement on the reconstructed image can be achieved with this technique due to the capability of recovering the diffraction phases of low-intensity signals.

  7. Suppression of image autocorrelation artefacts in spectral domain optical coherence tomography and multiwave digital holography

    NASA Astrophysics Data System (ADS)

    Gelikonov, V. M.; Gelikonov, G. V.; Terpelov, D. A.; Shabanov, D. V.; Shilyagin, P. A.

    2012-05-01

    An improved method for suppressing image artefacts in spectral domain optical coherence tomography (SD OCT) and multiwave digital holography, caused by the influence of coherent noise in the course of successive registration of an autocorrelation component and informative signal is reported. The method allows complete suppression of all types of coherent noises, provided that the sample of values used to record the autocorrelation component satisfies the conditions of Kotelnikov's theorem: in SD OCT — for the transverse structure of the studied medium, in multiwave digital holography — for the envelop function of the radiation source frequency tuning spectrum.

  8. Super-Resolved Digital Holography Based on the Coherent Diffraction Imaging Scheme

    NASA Astrophysics Data System (ADS)

    Wang, Bao-Sheng; Pan, Xing-Chen; Wang, Hai-Yan; Cheng, Jun; Gao, Shu-Mei; Liu, Cheng; Zhu, Jian-Qiang

    2013-05-01

    An algorithm is proposed to enhance the resolution of digital holography by retrieving the frequency components lost in common holograms. A pinhole is placed directly behind the specimen to record the hologram, and an iterative scheme commonly used in coherent diffraction imaging is adopted for the reconstruction. Since some of the frequency components lost in common digital holography can be properly retrieved, the resolution of the reconstructed image is remarkably improved. Theoretical analysis and computer simulations are presented to demonstrate the feasibility of this proposed technique.

  9. A phase-shifting in-line digital holography of pre-magnification on imaging research

    NASA Astrophysics Data System (ADS)

    Lin, Qiaowen; Wang, Dayong; Rong, Lu; Wang, Yunxin; Zhao, Jie; Panezai, Spozmai

    2013-12-01

    A phase shifting digital holography with pre-magnification is designed. In order to fully utilize the bandwidth of the camera, a four-step phase-shifting digital holography is adopted to retrieve the complex distribution of the object. To further enhance the resolution of the reconstructed image without phase aberration, two microscope objectives (MOs) are placed in front of the object and the reference mirror. The MO in the reference arm provides parallel beam at the PZT plane thus improve the precision of the phase shifting. A 1951 USAF negative resolution target is used as the sample. Experiment result demonstrates the feasibility of the proposed method.

  10. Suppression of image autocorrelation artefacts in spectral domain optical coherence tomography and multiwave digital holography

    SciTech Connect

    Gelikonov, V M; Gelikonov, G V; Terpelov, D A; Shabanov, D V; Shilyagin, P A

    2012-05-31

    An improved method for suppressing image artefacts in spectral domain optical coherence tomography (SD OCT) and multiwave digital holography, caused by the influence of coherent noise in the course of successive registration of an autocorrelation component and informative signal is reported. The method allows complete suppression of all types of coherent noises, provided that the sample of values used to record the autocorrelation component satisfies the conditions of Kotelnikov's theorem: in SD OCT - for the transverse structure of the studied medium, in multiwave digital holography - for the envelop function of the radiation source frequency tuning spectrum.

  11. Localized acoustic surface modes

    NASA Astrophysics Data System (ADS)

    Farhat, Mohamed; Chen, Pai-Yen; Bağcı, Hakan

    2016-04-01

    We introduce the concept of localized acoustic surface modes. 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.

  12. Low frequency acoustic microscope

    DOEpatents

    Khuri-Yakub, Butrus T.

    1986-11-04

    A scanning acoustic microscope is disclosed for the detection and location of near surface flaws, inclusions or voids in a solid sample material. A focused beam of acoustic energy is directed at the sample with its focal plane at the subsurface flaw, inclusion or void location. The sample is scanned with the beam. Detected acoustic energy specularly reflected and mode converted at the surface of the sample and acoustic energy reflected by subsurface flaws, inclusions or voids at the focal plane are used for generating an interference signal which is processed and forms a signal indicative of the subsurface flaws, inclusions or voids.

  13. Acoustic dispersive prism.

    PubMed

    Esfahlani, Hussein; Karkar, Sami; Lissek, Herve; Mosig, Juan R

    2016-01-01

    The optical dispersive prism is a well-studied element, which allows separating white light into its constituent spectral colors, and stands in nature as water droplets. In analogy to this definition, the acoustic dispersive prism should be an acoustic device with capability of splitting a broadband acoustic wave into its constituent Fourier components. However, due to the acoustical nature of materials as well as the design and fabrication difficulties, there is neither any natural acoustic counterpart of the optical prism, nor any artificial design reported so far exhibiting an equivalent acoustic behaviour. Here, based on exotic properties of the acoustic transmission-line metamaterials and exploiting unique physical behaviour of acoustic leaky-wave radiation, we report the first acoustic dispersive prism, effective within the audible frequency range 800 Hz-1300 Hz. The dispersive nature, and consequently the frequency-dependent refractive index of the metamaterial are exploited to split the sound waves towards different and frequency-dependent directions. Meanwhile, the leaky-wave nature of the structure facilitates the sound wave radiation into the ambient medium. PMID:26739504

  14. Acoustic dispersive prism

    PubMed Central

    Esfahlani, Hussein; Karkar, Sami; Lissek, Herve; Mosig, Juan R.

    2016-01-01

    The optical dispersive prism is a well-studied element, which allows separating white light into its constituent spectral colors, and stands in nature as water droplets. In analogy to this definition, the acoustic dispersive prism should be an acoustic device with capability of splitting a broadband acoustic wave into its constituent Fourier components. However, due to the acoustical nature of materials as well as the design and fabrication difficulties, there is neither any natural acoustic counterpart of the optical prism, nor any artificial design reported so far exhibiting an equivalent acoustic behaviour. Here, based on exotic properties of the acoustic transmission-line metamaterials and exploiting unique physical behaviour of acoustic leaky-wave radiation, we report the first acoustic dispersive prism, effective within the audible frequency range 800 Hz–1300 Hz. The dispersive nature, and consequently the frequency-dependent refractive index of the metamaterial are exploited to split the sound waves towards different and frequency-dependent directions. Meanwhile, the leaky-wave nature of the structure facilitates the sound wave radiation into the ambient medium. PMID:26739504

  15. Acoustic dispersive prism

    NASA Astrophysics Data System (ADS)

    Esfahlani, Hussein; Karkar, Sami; Lissek, Herve; Mosig, Juan R.

    2016-01-01

    The optical dispersive prism is a well-studied element, which allows separating white light into its constituent spectral colors, and stands in nature as water droplets. In analogy to this definition, the acoustic dispersive prism should be an acoustic device with capability of splitting a broadband acoustic wave into its constituent Fourier components. However, due to the acoustical nature of materials as well as the design and fabrication difficulties, there is neither any natural acoustic counterpart of the optical prism, nor any artificial design reported so far exhibiting an equivalent acoustic behaviour. Here, based on exotic properties of the acoustic transmission-line metamaterials and exploiting unique physical behaviour of acoustic leaky-wave radiation, we report the first acoustic dispersive prism, effective within the audible frequency range 800 Hz-1300 Hz. The dispersive nature, and consequently the frequency-dependent refractive index of the metamaterial are exploited to split the sound waves towards different and frequency-dependent directions. Meanwhile, the leaky-wave nature of the structure facilitates the sound wave radiation into the ambient medium.

  16. Resuscitation with Na+/H+ exchanger inhibitor in traumatic haemorrhagic shock: cardiopulmonary performance, oxygen transport and tissue inflammation.

    PubMed

    Wu, Dongmei; Qi, Jiansong; Dai, Hui; Doods, Henri; Abraham, William M

    2010-03-01

    1. The aim of the present study was to examine the effects of inhibition of the Na(+)/H(+) exchanger (NHE-1) on cardiopulmonary performance, oxygen carrying capacity and tissue inflammation in a pig model of traumatic haemorrhage-resuscitation. 2. In 12 instrumented anaesthetized pigs, traumatic haemorrhage was modelled by producing tibia fractures, followed by haemorrhage of 25 mL/kg for 20 min, and then a 4 mm hepatic arterial tear with surgical repair after 20 min. Animals then underwent low-volume fluid resuscitation with either Hextend (vehicle; n = 6; Hospira, Lake Forest, IL, USA) or 3 mg/kg BIIB513 (an NHE-1 inhibitor) + Hextend (n = 6). The experiment was terminated 6 h after the beginning of resuscitation. 3. Compared with vehicle-treated controls, the addition of NHE-1 inhibition with BIIB513 significantly improved the left ventricle stroke work index and attenuated increases in pulmonary arterial pressure and pulmonary vascular resistance. Furthermore, BIIB513 treatment significantly increased the oxygenated haemoglobin ratio, blood oxygen content and mixed venous blood oxygen saturation and improved blood oxygen delivery. In addition, BIIB513 treatment reduced lung tissue levels of interleukin-6 by 80%, tumour necrosis factor-alpha by 37% and myeloperoxidase activity by 38%. Nuclear factor-kappaB DNA binding activity in the lung was also slightly and significantly attenuated following BIIB513 treatment. 4. In conclusion, the present study shows that NHE-1 inhibition facilitates the response to fluid resuscitation after traumatic haemorrhage by improving cardiac function, pulmonary vascular function and oxygen carrying capacity, which results in reduced tissue inflammatory injury. PMID:19769605

  17. Parathyroid hormone inhibition of Na(+)/H(+) exchanger 3 transcription: Intracellular signaling pathways and transcription factor expression.

    PubMed

    Neri, Elida Adalgisa; Bezerra, Camila Nogueira Alves; Queiroz-Leite, Gabriella Duarte; Polidoro, Juliano Zequini; Rebouças, Nancy Amaral

    2015-06-12

    The main transport mechanism of reabsorption of sodium bicarbonate and fluid in the renal proximal tubules involves Na(+)/H(+) exchanger 3 (NHE3), which is acutely and chronically downregulated by parathyroid hormone (PTH). Although PTH is known to exert an inhibitory effect on NHE3 expression and transcription, the molecular mechanisms involved remain unclear. Here, we demonstrated that, in opossum kidney proximal tubule (OKP) cells, PTH-induced inhibition of Nhe3 gene promoter occurs even in the core promoter that controls expression of the reporter gene. We found that inhibition of the protein kinase A (PKA) and Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathways transformed PTH from an inhibitor of promoter activity into an activator of that same activity, as did point mutations in the EGR1, Sp1, and Sp3 binding consensus elements in the promoter. In nuclear extracts of PTH-treated OKP cells, we also observed increased expression of EGR1 mRNA and of some Sp3 isoforms. Electrophoretic mobility shift assay showed a supershift of the -61 to -42-bp probe with an anti-EGR1 antibody in PTH-treated cells, suggesting that EGR1 binding is relevant for the inhibitory activity of PTH. We conclude that PTH-induced inhibition of NHE3 transcription is related to higher EGR1 expression; to EGR1 binding to the proximal and core promoters; and to PKA and JAK/STAT pathway activation. This mechanism might be responsible, at least in part, for lower NHE3 expression and sodium reabsorption in renal proximal tubules in the presence of high PTH levels. PMID:25888790

  18. Drug Transporters and Na+/H+ Exchange Regulatory Factor PSD-95/Drosophila Discs Large/ZO-1 Proteins

    PubMed Central

    Walsh, Dustin R.; Nolin, Thomas D.

    2015-01-01

    Drug transporters govern the absorption, distribution, and elimination of pharmacologically active compounds. Members of the solute carrier and ATP binding-cassette drug transporter family mediate cellular drug uptake and efflux processes, thereby coordinating the vectorial movement of drugs across epithelial barriers. To exert their physiologic and pharmacological function in polarized epithelia, drug transporters must be targeted and stabilized to appropriate regions of the cell membrane (i.e., apical versus basolateral). Despite the critical importance of drug transporter membrane targeting, the mechanisms that underlie these processes are largely unknown. Several clinically significant drug transporters possess a recognition sequence that binds to PSD-95/Drosophila discs large/ZO-1 (PDZ) proteins. PDZ proteins, such as the Na+/H+ exchanger regulatory factor (NHERF) family, act to stabilize and organize membrane targeting of multiple transmembrane proteins, including many clinically relevant drug transporters. These PDZ proteins are normally abundant at apical membranes, where they tether membrane-delimited transporters. NHERF expression is particularly high at the apical membrane in polarized tissue such as intestinal, hepatic, and renal epithelia, tissues important to drug disposition. Several recent studies have highlighted NHERF proteins as determinants of drug transporter function secondary to their role in controlling membrane abundance and localization. Mounting evidence strongly suggests that NHERF proteins may have clinically significant roles in pharmacokinetics and pharmacodynamics of several pharmacologically active compounds and may affect drug action in cancer and chronic kidney disease. For these reasons, NHERF proteins represent a novel class of post-translational mediators of drug transport and novel targets for new drug development. PMID:26092975

  19. Integrated optics, fiber optics and holography; International School on Coherent Optics and Holography, 2nd, Varna, Bulgaria, September 28-October 3, 1981, Proceedings

    NASA Astrophysics Data System (ADS)

    Simova, P.; Savatinova, I.; Tsonev, L.

    Attention is given to such topics as developments in multimode and monomode integrated optics, the use of holographic techniques to produce integrated-optic elements, the fabrication of optical strip waveguides by diffusion and ion implantation, and the fabrication and investigation of optically controlled CdS(x)Se(1-x) thin-film waveguides. Papers are also presented on the theory of fiber-optic waveguides, mode power distribution measurements in optical fibers, methods for determining the index profile distribution in optical fibers, and highlights of optical-fiber communications systems. The physical properties of media for optical memories and holography, the synthesis of spatial-frequency filters for a coherent optical processor, and pulsed holography and its application are also examined. No individual items are abstracted in this volume

  20. Acoustics Critical Readiness Review

    NASA Technical Reports Server (NTRS)

    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.