How hummingbirds hum: Acoustic holography of hummingbirds during maneuvering flight

NASA Astrophysics Data System (ADS)

Hightower, Ben; Wijnings, Patrick; Ingersoll, Rivers; Chin, Diana; Scholte, Rick; Lentink, David

2017-11-01

Hummingbirds make a characteristic humming sound when they flap their wings. The physics and the biological significance of hummingbird aeroacoustics is still poorly understood. We used acoustic holography and high-speed cameras to determine the acoustic field of six hummingbirds while they either hovered stationary in front of a flower or maneuvered to track flower motion. We used a robotic flower that oscillated either laterally or longitudinally with a linear combination of 20 different frequencies between 0.2 and 20 Hz, a range that encompasses natural flower vibration frequencies in wind. We used high-speed marker tracking to dissect the transfer function between the moving flower, the head, and body of the bird. We also positioned four acoustic arrays equipped with 2176 microphones total above, below, and in front of the hummingbird. Acoustic data from the microphones were back-propagated to planes adjacent to the hummingbird to create the first real-time holograms of the pressure field a hummingbird generates in vivo. Integration of all this data offers insight into how hummingbirds modulate the acoustic field during hovering and maneuvering flight.

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.

A sparse equivalent source method for near-field acoustic holography.

PubMed

Fernandez-Grande, Efren; Xenaki, Angeliki; Gerstoft, Peter

2017-01-01

This study examines a near-field acoustic holography method consisting of a sparse formulation of the equivalent source method, based on the compressive sensing (CS) framework. The method, denoted Compressive-Equivalent Source Method (C-ESM), encourages spatially sparse solutions (based on the superposition of few waves) that are accurate when the acoustic sources are spatially localized. The importance of obtaining a non-redundant representation, i.e., a sensing matrix with low column coherence, and the inherent ill-conditioning of near-field reconstruction problems is addressed. Numerical and experimental results on a classical guitar and on a highly reactive dipole-like source are presented. C-ESM is valid beyond the conventional sampling limits, making wide-band reconstruction possible. Spatially extended sources can also be addressed with C-ESM, although in this case the obtained solution does not recover the spatial extent of the source.

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.

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

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.

Acoustic holograms of active regions

NASA Astrophysics Data System (ADS)

Chou, Dean-Yi

2008-10-01

We propose a method to study solar magnetic regions in the solar interior with the principle of optical holography. A magnetic region in the solar interior scatters the solar background acoustic waves. The scattered waves and background waves could form an interference pattern on the solar surface. We investigate the feasibility of detecting this interference pattern on the solar surface, and using it to construct the three-dimensional scattered wave from the magnetic region with the principle of optical holography. In solar acoustic holography, the background acoustic waves play the role of reference wave; the magnetic region plays the role of the target object; the interference pattern, acoustic power map, on the solar surface plays the role of the hologram.

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.

Visualization of pass-by noise by means of moving frame acoustic holography.

PubMed

Park, S H; Kim, Y H

2001-11-01

The noise generated by pass-by test (ISO 362) was visualized. The moving frame acoustic holography was improved to visualize the pass-by noise and predict its level. The proposed method allowed us to visualize tire and engine noise generated by pass-by test based on the following assumption; the noise can be assumed to be quasistationary. This is first because the speed change during the period of our interest is negligible and second because the frequency change of the noise is also negligible. The proposed method was verified by a controlled loud speaker experiment. Effects of running condition, e.g., accelerating according to ISO 362, cruising at constant speed, and coasting down, on the radiated noise were also visualized. The visualized results show where the tire noise is generated and how it propagates.

Ghost Images in Helioseismic Holography? Toy Models in a Uniform Medium

NASA Astrophysics Data System (ADS)

Yang, Dan

2018-02-01

Helioseismic holography is a powerful technique used to probe the solar interior based on estimations of the 3D wavefield. The Porter-Bojarski holography, which is a well-established method used in acoustics to recover sources and scatterers in 3D, is also an estimation of the wavefield, and hence it has the potential of being applied to helioseismology. Here we present a proof-of-concept study, where we compare helioseismic holography and Porter-Bojarski holography under the assumption that the waves propagate in a homogeneous medium. We consider the problem of locating a point source of wave excitation inside a sphere. Under these assumptions, we find that the two imaging methods have the same capability of locating the source, with the exception that helioseismic holography suffers from "ghost images" ( i.e. artificial peaks away from the source location). We conclude that Porter-Bojarski holography may improve the method currently used in helioseismology.

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

NASA Astrophysics Data System (ADS)

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.

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.

Acoustical standards in engineering acoustics

NASA Astrophysics Data System (ADS)

Burkhard, Mahlon D.

2004-05-01

The Engineering Acoustics Technical Committee is concerned with the evolution and improvement of acoustical techniques and apparatus, and with the promotion of new applications of acoustics. As cited in the Membership Directory and Handbook (2002), the interest areas include transducers and arrays; underwater acoustic systems; acoustical instrumentation and monitoring; applied sonics, promotion of useful effects, information gathering and transmission; audio engineering; acoustic holography and acoustic imaging; acoustic signal processing (equipment and techniques); and ultrasound and infrasound. Evident connections between engineering and standards are needs for calibration, consistent terminology, uniform presentation of data, reference levels, or design targets for product development. Thus for the acoustical engineer standards are both a tool for practices, for communication, and for comparison of his efforts with those of others. Development of many standards depends on knowledge of the way products are put together for the market place and acoustical engineers provide important input to the development of standards. Acoustical engineers and members of the Engineering Acoustics arm of the Society both benefit from and contribute to the Acoustical Standards of the Acoustical Society.

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.

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.

The plant vacuolar Na+/H+ antiport.

PubMed

Barkla, B J; Apse, M P; Manolson, M F; Blumwald, E

1994-01-01

Salt stress imposes severe limitations on plant growth, however, the extent of growth reduction depends upon the soil salinity level and the plant species. One of the mechanisms employed by salt tolerant plants is the effective vacuolar compartmentalization of sodium. The sequestration of sodium into the vacuole occurs by the operation of a Na+/H+ antiport located at the tonoplast. Evidence for a plant vacuolar Na+/H+ antiport has been demonstrated in tissues, intact vacuoles and isolated tonoplast vesicles. In sugar beet cell suspensions, the activity of the vacuolar Na+/H+ antiport increased with increasing NaCl concentrations in the growth medium. This increased activity was correlated with the increased synthesis of a 170 kDa tonoplast polypeptide. In vivo labelling of tonoplast proteins showed the enhanced synthesis of the 170 kDa polypeptide not only upon exposure of the cells to salt, but also when the cells were grown in the presence of amiloride. Exposure of the cells to amiloride also resulted in increased vacuolar Na+/H+ antiport activity. Polyclonal antibodies raised against the 170 kDa polypeptide almost completely inhibited the antiport activity, suggesting the association of this protein with the plant vacuolar Na+/H+ antiport. Antibodies against the Na+/H+ antiport-associated polypeptide were used to screen a Beta lambda ZAP expression library. A partial clone of 1.65 kb was sequenced and found to encode a polypeptide with a putative transmembrane domain and a large hydrophilic C terminus. This clone showed no homology to any previously cloned gene at either the nucleic acid or the amino acid level.

Theoretical Properties of Acoustical Speckle Interferometry.

DTIC Science & Technology

1980-09-01

an obvious one , since it was first performed in the acoustical holography. An acoustical speckle interferometry study has been demonstrated to be a...experiments in which pulses were used to study the propagation of the circumferential waves on aluminum cylinders immersed in water. In 1969, Bunney...destructive Testing SB. ABTRACT aCdo as revers. NW ass a" Id by block numb") Acoustical speckle interferometry is based locally on the elastodynamic response

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…

Holography and tomography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Howells, M.

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.

Panel acoustic contribution analysis.

PubMed

Wu, Sean F; Natarajan, Logesh Kumar

2013-02-01

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

Characterization of acoustically induced deformations of human tympanic membranes by digital holography and shearography

NASA Astrophysics Data System (ADS)

Flores-Moreno, J. M.; Furlong, Cosme; Cheng, Jeffrey T.; Rosowski, John J.; Merchant, S. N.

2011-08-01

Recently, we introduced a Digital Optoelectronic Holographic System (DOEHS) for measurement of acoustically induced deformations of the human tympanic membrane (TM) in order to study and diagnose pathologic conditions of the middle-ear. The DOEHS consists of laser-delivery illumination (IS), optical head (OH), image-processing computer (IP), and positioning arm (PS) subsystems. Holographic information is recorded by a CCD and numerically reconstructed by Fresnel approximation. Our holographic otoscope system is currently deployed in a clinic and is packaged in a custom design. Since digital holography is a high sensitivity measurement technique and the interfering light waves travel along different paths, it makes measurements acquired by DOEHS susceptible to external vibrations. In order to avoid this susceptibility, we are testing a shearography setup as OH. Shearography presents same advantages as holographic interferometry, but it is less susceptible to vibration and external noise, which is a characteristic needed for the use of our techniques in a clinical environment. In this paper we present work in progress in our development of a shearography technique based on a Mach-Zehnder configuration as OH and demonstrate its application by quantifying vibrations modes in thin membranes, including human TM. Results are compared with those obtained with DOEHS.

Holograms for acoustics.

PubMed

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

2016-09-22

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

Is holography ready for yet another life? or make holography great again

NASA Astrophysics Data System (ADS)

Trolinger, James D.

2016-08-01

Holographic metrology, unlike most other applications of holography, has always thrived and continues to thrive by continuously incorporating new supporting technologies that make it more powerful and useful. Successes, failures, lives, and deaths are examined and recognized as evolutionary steps that position the field where opportunities are as great and as many as ever. This is a story of that evolution. Comparisons and analogies with other applications of holography such as data storage, archiving, the arts, entertainment, advertising, and security and their evolution are interesting. Critical events, successes, mistakes, and coincidences represent milestones of abandonment or failure to deliver in many holography communities that followed a different evolutionary path. Events and new technical developments continue to emerge in supporting fields that can revive and expand all holography applications. New opportunities are described with encouragement to act on them and take some risks. Don't wait until all of the required technology and hardware are available, because good scientists always act before then. The paper is about "making holography great again" and your opportunity to be a part of the upcoming revolution. Although the discussion focuses on holographic metrology, the same principles should apply to other holography communities.

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?"

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?

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.

ATP Dependence of Na+/H+ Exchange

PubMed Central

Demaurex, Nicolas; Romanek, Robert R.; Orlowski, John; Grinstein, Sergio

1997-01-01

We studied the ATP dependence of NHE-1, the ubiquitous isoform of the Na+/H+ antiporter, using the whole-cell configuration of the patch-clamp technique to apply nucleotides intracellularly while measuring cytosolic pH (pHi) by microfluorimetry. Na+/H+ exchange activity was measured as the Na+-driven pHi recovery from an acid load, which was imposed via the patch pipette. In Chinese hamster ovary (CHO) fibroblasts stably transfected with NHE-1, omission of ATP from the pipette solution inhibited Na+/H+ exchange. Conversely, ATP perfusion restored exchange activity in cells that had been metabolically depleted by 2-deoxy-d-glucose and oligomycin. In cells dialyzed in the presence of ATP, no “run-down” was observed even after extended periods, suggesting that the nucleotide is the only diffusible factor required for optimal NHE-1 activity. Half-maximal activation of the antiporter was obtained at ∼5 mM Mg-ATP. Submillimolar concentrations failed to sustain Na+/H+ exchange even when an ATP regenerating system was included in the pipette solution. High ATP concentrations are also known to be required for the optimal function of other cation exchangers. In the case of the Na/Ca2+ exchanger, this requirement has been attributed to an aminophospholipid translocase, or “flippase.” The involvement of this enzyme in Na+/H+ exchange was examined using fluorescent phosphatidylserine, which is actively translocated by the flippase. ATP depletion decreased the transmembrane uptake of NBD-labeled phosphatidylserine (NBD-PS), indicating that the flippase was inhibited. Diamide, an agent reported to block the flippase, was as potent as ATP depletion in reducing NBD-PS uptake. However, diamide had no effect on Na+/H+ exchange, implying that the effect of ATP is not mediated by changes in lipid distribution across the plasma membrane. K-ATP and ATPγS were as efficient as Mg-ATP in sustaining NHE-1 activity, while AMP-PNP and AMP-PCP only partially substituted for ATP. In

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…

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.

Effect of azathioprine on Na(+)/H(+) exchanger activity in dendritic cells.

PubMed

Bhandaru, Madhuri; Pasham, Venkanna; Yang, Wenting; Bobbala, Diwakar; Rotte, Anand; Lang, Florian

2012-01-01

Azathioprine is a powerful immunosuppressive drug, which is partially effective by interfering with the maturation and function of dendritic cells (DCs), antigen-presenting cells linking innate and adaptive immunity. DCs are stimulated by bacterial lipopolysaccharides (LPS), which trigger the formation of reactive oxygen species (ROS), paralleled by activation of the Na(+)/H(+) exchanger. The carrier is involved in the regulation of cytosolic pH, cell volume and migration. The present study explored whether azathioprine influences Na(+)/H(+) exchanger activity in DCs. DCs were isolated from murine bone marrow, cytosolic pH (pH(i)) was estimated utilizing 2',7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein (BCECF-AM) fluorescence, Na(+)/H(+) exchanger activity from the Na(+)-dependent realkalinization following an ammonium pulse, cell volume from forward scatter in FACS analysis, ROS production from 2',7'-dichlorodihydrofluorescein diacetate (DCFDA) fluorescence, TNFα release utilizing ELISA, and migration utilizing transwell migration assays. Exposure of DCs to lipopolysaccharide (LPS, 1 μg/ml) led to a transient increase of Na(+)/H(+) exchanger activity, an effect paralleled by ROS formation, increased cell volume, TNFα production and stimulated migration. Azathioprine (10 μM) did not significantly alter the Na(+)/H(+) exchanger activity, cell volume and ROS formation prior to LPS exposure but significantly blunted the LPS-induced stimulation of Na(+)/H(+) exchanger activity, ROS formation, cell swelling, TNFα production and cell migration. In conclusion, azathioprine interferes with the activation of dendritic cell Na(+)/H(+) exchanger by bacterial lipopolysaccharides, an effect likely participating in the anti-inflammatory action of the drug. Copyright © 2012 S. Karger AG, Basel.

Na+/H+ exchange activity in the plasma membrane of Arabidopsis.

PubMed

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

2003-06-01

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.

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.

[Nah-plasmids of IncP-9 group from natural strains of Pseudomonas].

PubMed

Levchuk, A A; Bulyga, I M; Izmalkova, T Iu; Sevast'ianovich, Ia R; Kosheleva, I A; Thomas, C M; Titok, M A

2006-01-01

Use of polymerase chain reaction helped to establish that the most frequent among naphthalene utilizing bacteria, isolated on the territory of Belarus, are Nah-plasmids of IncP-9 incompatibility group and those with indefinite systematic belonging. With the help of classical test of incompatibility, restriction and sequence analyses three new subgroups within the IncP-9 group were discovered (zeta, eta and IncP-9-like replicons). Conducting of restriction analysis for amplification products of nahG and nahAc genes allowed us to reveal, in addition to known sequences of stated determinants, two new types of nahG gene. Restriction analysis performed on amplification products of 16S RNA genes (ARDRA method) showed that native hosts of Nah-plasmids of IncP-9 group are not only fluorescent bacteria from genus Pseudomonas (P. fluorescens, P. putida, P. aeruginosa, P. species), but also non-fluorescent bacteria with indefinite specific belonging.

Thermodynamic holography.

PubMed

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

2015-10-19

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.

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.

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.

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.

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

Na+/H+ antiport is essential for Yersinia pestis virulence.

PubMed

Minato, Yusuke; Ghosh, Amit; Faulkner, Wyatt J; Lind, Erin J; Schesser Bartra, Sara; Plano, Gregory V; Jarrett, Clayton O; Hinnebusch, B Joseph; Winogrodzki, Judith; Dibrov, Pavel; Häse, Claudia C

2013-09-01

Na(+)/H(+) antiporters are ubiquitous membrane proteins that play a central role in the ion homeostasis of cells. In this study, we examined the possible role of Na(+)/H(+) antiport in Yersinia pestis virulence and found that Y. pestis strains lacking the major Na(+)/H(+) antiporters, NhaA and NhaB, are completely attenuated in an in vivo model of plague. The Y. pestis derivative strain lacking the nhaA and nhaB genes showed markedly decreased survival in blood and blood serum ex vivo. Complementation of either nhaA or nhaB in trans restored the survival of the Y. pestis nhaA nhaB double deletion mutant in blood. The nhaA nhaB double deletion mutant also showed inhibited growth in an artificial serum medium, Opti-MEM, and a rich LB-based medium with Na(+) levels and pH values similar to those for blood. Taken together, these data strongly suggest that intact Na(+)/H(+) antiport is indispensable for the survival of Y. pestis in the bloodstreams of infected animals and thus might be regarded as a promising noncanonical drug target for infections caused by Y. pestis and possibly for those caused by other blood-borne bacterial pathogens.

Nanoscale Imaging of Buried Structures via Scanning Near-Field Ultrasound Holography

NASA Astrophysics Data System (ADS)

Shekhawat, Gajendra S.; Dravid, Vinayak P.

2005-10-01

A nondestructive imaging method, scanning near-field ultrasound holography (SNFUH), has been developed that provides depth information as well as spatial resolution at the 10- to 100-nanometer scale. In SNFUH, the phase and amplitude of the scattered specimen ultrasound wave, reflected in perturbation to the surface acoustic standing wave, are mapped with a scanning probe microscopy platform to provide nanoscale-resolution images of the internal substructure of diverse materials. We have used SNFUH to image buried nanostructures, to perform subsurface metrology in microelectronic structures, and to image malaria parasites in red blood cells.

Holography Of Art Objects

NASA Astrophysics Data System (ADS)

Wuerker, R. F.

1980-05-01

In time, holography will have a major impact on all types of displays. Priceless, one of a kind artifacts can be copied and disseminated for esthetic and education purposes. Additionally, holography interferometry can safely test artifacts for incipient faults or damage, allowing corrective measures to be applied at an early stage.

A Thermoplastic Acoustical Holography Recording Device.

DTIC Science & Technology

1980-09-25

Swinson, W. F. Ranson, D. Smith, H. K. Liu, Mr. J. A. Schaeffel , and Mr. Keith Rodgers. I. INTRODUCTION The purpose of this report is to describe the...Letters, Vol. 11 (1967), p. 294. 6. Schaeffel , J. A., Jr., "Acoustical Speckle Interferometry," Technical Report T-79-39, US Army Missile Research and...Arlington, VA 22209 DRSMI-LP, Mr. Voigt 1 -R 1 -RL, Mr. Comus 1 -RLA, Mr. Pettey 1 -RLA 1 Mr. Schaeffel 50 -RPT (Reference Copy) I (Record Copy) 1 -RPR 15 35 ~j~fj D-T I -C

HoloNetwork: communicating science through holography

NASA Astrophysics Data System (ADS)

Pombo, Pedro; Santos, Emanuel; Magalhães, Carolina

2017-03-01

Since 1997 a program dedicated to holography has been developed and implemented in Portugal. This program started with focus on schools and science education. The HoloNetwork was created and it has been spread at a National level, involving a group of thirty schools and hundreds of students and teachers. In 2009 this network started to work to achieve a new target, the general public. With this goal, a larger program was developed with focus on science and society and on science communication through holography. For the implementation of this new program, special holography outreach activities were built, dedicated to informal learning and seven Science Centers around Portugal were add into the HoloNetwork. During last years, we have been working on holography, based on two main branches, one dedicated to schools and with the aimed to promote physics teaching and to teach how to make holograms, and another dedicated to society and with the aimed to promote holography and to increase scientific literacy. This paper would analyze the educational program, all holography outreach activities, exhibitions or events, all equipments, materials and setups used and it would present the holographic techniques explored with students or with the public. Finally, the results obtained in this work would be present and explored, with focus on students impact and outcomes, taking into account the public engagement on holography and its effect into scientific culture and analyzing the quality of holograms made by students and by the general public. subject.

Principle and Reconstruction Algorithm for Atomic-Resolution Holography

NASA Astrophysics Data System (ADS)

Matsushita, Tomohiro; Muro, Takayuki; Matsui, Fumihiko; Happo, Naohisa; Hosokawa, Shinya; Ohoyama, Kenji; Sato-Tomita, Ayana; Sasaki, Yuji C.; Hayashi, Kouichi

2018-06-01

Atomic-resolution holography makes it possible to obtain the three-dimensional (3D) structure around a target atomic site. Translational symmetry of the atomic arrangement of the sample is not necessary, and the 3D atomic image can be measured when the local structure of the target atomic site is oriented. Therefore, 3D local atomic structures such as dopants and adsorbates are observable. Here, the atomic-resolution holography comprising photoelectron holography, X-ray fluorescence holography, neutron holography, and their inverse modes are treated. Although the measurement methods are different, they can be handled with a unified theory. The algorithm for reconstructing 3D atomic images from holograms plays an important role. Although Fourier transform-based methods have been proposed, they require the multiple-energy holograms. In addition, they cannot be directly applied to photoelectron holography because of the phase shift problem. We have developed methods based on the fitting method for reconstructing from single-energy and photoelectron holograms. The developed methods are applicable to all types of atomic-resolution holography.

Recent developments on holography in China

NASA Astrophysics Data System (ADS)

Hsu, Dahsiung; Jiao, Jiangzhong; Tao, Huiying; Long, Pin

1991-02-01

Since the 1985 Lake Forest International Conference on display holography, USA) more developments have been made on holographic applications in China among which the important events and progress were: the International Conference on holography applications em bossing holography new holographic optical elements and equipments etc. . 1. INTERNATIONAL CONFEPENCE ON GRAPHY APPLICATIONS'' ( I CHA ''86. BEIJING) More than 280 holographers from 18 countries gathered in the Science Hall in Beijing from July 2 to for the International Conference on holography applications''86. The conference was sponsor ed by the Chinese OPtical Society the Chinese Theoretical Applied Mechanics Society and cosponsored by the Society of Photooptical Instrumentation Engineers the European Photonic Association in cooperation with the China Association for Science And Technology. It was chaired by Prof. Wang Daheng vice president of the China Association for Science Technology and president of the Chinese Optical Society cochaired by DP. H. J. Caulfield of the Univ. of Alabama Dr. G. von Bally of the Munster Univ. in West Germany and Dr. J. Tsujiuchi of the Tokyo Institute of Technology. SPIE Vol. 1238 Three-Dimensional Holography: Science Culture Education (1989) / 13

Vibration testing and analysis using holography

NASA Technical Reports Server (NTRS)

1971-01-01

Time average holography is useful in recording steady state vibrational mode patterns. Phase relationships under steady state conditions are measured with real time holography and special phase shifting techniques. Data from Michelson interferometer verify vibration amplitudes from holographic data.

Acoustic Holographic Rendering with Two-dimensional Metamaterial-based Passive Phased Array

PubMed Central

Xie, Yangbo; Shen, Chen; Wang, Wenqi; Li, Junfei; Suo, Dingjie; Popa, Bogdan-Ioan; Jing, Yun; Cummer, Steven A.

2016-01-01

Acoustic holographic rendering in complete analogy with optical holography are useful for various applications, ranging from multi-focal lensing, multiplexed sensing and synthesizing three-dimensional complex sound fields. Conventional approaches rely on a large number of active transducers and phase shifting circuits. In this paper we show that by using passive metamaterials as subwavelength pixels, holographic rendering can be achieved without cumbersome circuitry and with only a single transducer, thus significantly reducing system complexity. Such metamaterial-based holograms can serve as versatile platforms for various advanced acoustic wave manipulation and signal modulation, leading to new possibilities in acoustic sensing, energy deposition and medical diagnostic imaging. PMID:27739472

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.

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.

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.

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.

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.

Content metamorphosis in synthetic holography

NASA Astrophysics Data System (ADS)

Desbiens, Jacques

2013-02-01

A synthetic hologram is an optical system made of hundreds of images amalgamated in a structure of holographic cells. Each of these images represents a point of view on a three-dimensional space which makes us consider synthetic holography as a multiple points of view perspective system. In the composition of a computer graphics scene for a synthetic hologram, the field of view of the holographic image can be divided into several viewing zones. We can attribute these divisions to any object or image feature independently and operate different transformations on image content. In computer generated holography, we tend to consider content variations as a continuous animation much like a short movie. However, by composing sequential variations of image features in relation with spatial divisions, we can build new narrative forms distinct from linear cinematographic narration. When observers move freely and change their viewing positions, they travel from one field of view division to another. In synthetic holography, metamorphoses of image content are within the observer's path. In all imaging Medias, the transformation of image features in synchronisation with the observer's position is a rare occurrence. However, this is a predominant characteristic of synthetic holography. This paper describes some of my experimental works in the development of metamorphic holographic images.

Reconstructing the history of holography

NASA Astrophysics Data System (ADS)

Johnston, Sean F.

2003-05-01

This paper discusses large-scale but gradual changes in the subject of holography that have only recently become readily observable. Presenting an analysis of publications in holography over the past half century, the paper illustrates and discusses the evolving shape of the subject. Over 40,000 international information sources have been recorded, including some 20,000 papers, 10,000 books, nearly as many of these and at least 500 exhibitions. This statistical and sociological approach is combined with the identification of specific factors - notably the role of individuals, conferences, proof-of-concept demonstrations and exhibitions - to suggest that the development of holography has been unusually contingent on a variety of intellectual and social influences. The paper situates these observations about holography and holographers in the context of a wider discussion about the styles, purposes and difficulties of historical writing on technological subjects. It further suggests that this ongoing process of both recording and reconstructing technological history can be aided by identification of sources sometimes overlooked or undervalued by practitioners: unpublished archival materials such as private file collections; business records; or undervalued by practitioners: unpublished archival material such as private file collections; business records; accounts of unsuccessful activities; and, by no means least, anecdotal accounts inter-linked between participants.

Coherence-domain imaging with harmonic holography

NASA Astrophysics Data System (ADS)

Pu, Ye; Psaltis, Demetri

2017-08-01

Observing the fast dynamics of specific molecules or targets in three-dimensional (3D) space and time inside a crowded and complex environment, such as living cells or tissues, remain one of the grand open challenges in modern science. Harmonic holography tackle this challenge by combining the 3D imaging capability of holography with the ultrafast, coherent optical contrast offered by second-harmonic radiating imaging probes (SHRIMPs). Similar to fluorescence, the second-harmonic signal emitted from SHRIMPs provides a color contrast against the uninterested background scattering, which can be efficiently suppressed by an optical filter. We review the latest developments in SHRIMPs and harmonic holography and discuss their further applications in fluidics and biofluidics.

The mechanisms of brush border Na+/H+ exchanger activation by corticosteroids.

PubMed

Zallocchi, Marisa; Igarreta, Pilar; Calvo, Juan Carlos; Reboucas, Nancy Amaral; Damasco, María Christina

2003-02-01

Previously we showed that corticosterone and aldosterone increased proton fluxes in proximal tubule, by micropuncture and stationary microperfusion. Since the Na+/H+ exchanger is responsible for the main proximal proton secretion, we have now evaluated the effects aldosterone on Na+/H+ exchange activity in brush border vesicles. In order to evaluate the mechanism of action of glucocorticoids and mineralocorticoids, we studied the comparative effects of corticosterone and aldosterone on the abundance of NHE3 and NHE2 isoforms. We isolated renal brush border vesicles from rats by differential centrifugation in sham-operated, adrenalectomized, and adrenalectomized-aldosterone treated (ADX + aldosterone) animals. We measured the kinetics of H+ transport in response to increasing concentrations of Sodium Gluconate by fluorimetry using acridine orange. For Na+/H+ exchanger abundance we used Western blot analysis of brush border proteins in the above groups and in adrenalectomized-corticosterone treated rats. The Vmax in adrenalectomized animals was 22,162+/-1828 fluorescence units/min; in sham animals, 37,020+/-2722; and in ADX + aldosterone, 42,344+/-3044 (p<0.01 adrenalectomized vs others). No differences in Km were observed. Adrenalectomy decreased NHE3 abundance over Sham by 32% without modifying NHE2. Corticosterone-replacement enhanced NHE3 abundance by 76% and failed to increase NHE2. Aldosterone enhanced NHE2 abundance by 75% and did not increase NHE3. Mineralocorticoids enhance Na+/H+ exchange activity by increasing NHE2 abundance; glucocorticoids, by increasing NHE3 abundance.

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.

Advanced Electron Holography Applied to Electromagnetic Field Study in Materials Science.

PubMed

Shindo, Daisuke; Tanigaki, Toshiaki; Park, Hyun Soon

2017-07-01

Advances and applications of electron holography to the study of electromagnetic fields in various functional materials are presented. In particular, the development of split-illumination electron holography, which introduces a biprism in the illumination system of a holography electron microscope, enables highly accurate observations of electromagnetic fields and the expansion of the observable area. First, the charge distributions on insulating materials were studied by using split-illumination electron holography and including a mask in the illumination system. Second, the three-dimensional spin configurations of skyrmion lattices in a helimagnet were visualized by using a high-voltage holography electron microscope. Third, the pinning of the magnetic flux lines in a high-temperature superconductor YBa 2 Cu 3 O 7-y was analyzed by combining electron holography and scanning ion microscopy. Finally, the dynamic accumulation and collective motions of electrons around insulating biomaterial surfaces were observed by utilizing the amplitude reconstruction processes of electron holography. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Medical Holography for Basic Anatomy Training

DTIC Science & Technology

2013-12-01

Interservicel!ndustry Training, Simulation, and Education Conference (l/ITSEC) 2013 Medical Holography for Basic Anatomy Training Matthew Hackett...to the complex 3D structures inherent in human anatomy . One potential solution to this problem is to present medical content in three dimensions...traditional format via textbook handouts or through holography. Cognitive load analysis was performed to determine if a difference in cognitive effort was

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.

International Year of Light in Michigan: outdoor holography

NASA Astrophysics Data System (ADS)

Nees, John; Aku-Leh, Cynthia; Jones, Tim; Sala, Anca L.; Smith, Arlene; Dreyer, Elizabeth F. C.

2016-09-01

Outdoor holography is an activity created by the Michigan Light Project during the International Year of Light. Traditional holography is done in dark and quiet rooms. Using a kit from LitiHolo.com, we designed a way to make simple holograms outside in a noisy festival environment.

Local sharpening and subspace wavefront correction with predictive dynamic digital holography

NASA Astrophysics Data System (ADS)

Sulaiman, Sennan; Gibson, Steve

2017-09-01

Digital holography holds several advantages over conventional imaging and wavefront sensing, chief among these being significantly fewer and simpler optical components and the retrieval of complex field. Consequently, many imaging and sensing applications including microscopy and optical tweezing have turned to using digital holography. A significant obstacle for digital holography in real-time applications, such as wavefront sensing for high energy laser systems and high speed imaging for target racking, is the fact that digital holography is computationally intensive; it requires iterative virtual wavefront propagation and hill-climbing to optimize some sharpness criteria. It has been shown recently that minimum-variance wavefront prediction can be integrated with digital holography and image sharpening to reduce significantly large number of costly sharpening iterations required to achieve near-optimal wavefront correction. This paper demonstrates further gains in computational efficiency with localized sharpening in conjunction with predictive dynamic digital holography for real-time applications. The method optimizes sharpness of local regions in a detector plane by parallel independent wavefront correction on reduced-dimension subspaces of the complex field in a spectral plane.

Phase conjugate digital inline holography (PCDIH)

DOE PAGES

Guildenbecher, Daniel Robert; Hoffmeister, Kathryn N. Gabet; Kunzler, William Marley; ...

2018-01-12

We report digital inline holography (DIH) provides instantaneous three-dimensional (3D) measurements of diffracting objects; however, phase disturbances in the beam path can distort the imaging. In this Letter, a phase conjugate digital inline holography (PCDIH) configuration is proposed for removal of phase disturbances. Brillouin-enhanced four-wave mixing produces a phase conjugate signal that back propagates along the DIH beam path. Finally, the results demonstrate the removal of distortions caused by gas-phase shocks to recover 3D images of diffracting objects.

Phase conjugate digital inline holography (PCDIH)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guildenbecher, Daniel Robert; Hoffmeister, Kathryn N. Gabet; Kunzler, William Marley

We report digital inline holography (DIH) provides instantaneous three-dimensional (3D) measurements of diffracting objects; however, phase disturbances in the beam path can distort the imaging. In this Letter, a phase conjugate digital inline holography (PCDIH) configuration is proposed for removal of phase disturbances. Brillouin-enhanced four-wave mixing produces a phase conjugate signal that back propagates along the DIH beam path. Finally, the results demonstrate the removal of distortions caused by gas-phase shocks to recover 3D images of diffracting objects.

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)

Role of the Na+/H+ antiporter in rat proximal tubule bicarbonate absorption.

PubMed Central

Preisig, P A; Ives, H E; Cragoe, E J; Alpern, R J; Rector, F C

1987-01-01

Amiloride and the more potent amiloride analog, 5-(N-t-butyl) amiloride (t-butylamiloride), were used to examine the role of the Na+/H+ antiporter in bicarbonate absorption in the in vivo microperfused rat proximal convoluted tubule. Bicarbonate absorption was inhibited 29, 46, and 47% by 0.9 mM or 4.3 mM amiloride, or 1 mM t-butylamiloride, respectively. Sensitivity of the Na+/H+ antiporter to these compounds in vivo was examined using fluorescent measurements of intracellular pH with (2', 7')-bis(carboxyethyl)-(5,6)-carboxyfluorescein (BCECF). Amiloride and t-butylamiloride were shown to be as potent against the antiporter in vivo as in brush border membrane vesicles. A model of proximal tubule bicarbonate absorption was used to correct for changes in the luminal profiles for pH and inhibitor concentration, and for changes in luminal flow rate in the various series. We conclude that the majority of apical membrane proton secretion involved in transepithelial bicarbonate absorption is mediated by the Na+-dependent, amiloride-sensitive Na+H+ antiporter. However, a second mechanism of proton secretion contributes significantly to bicarbonate absorption. This mechanism is Na+-independent and amiloride-insensitive. PMID:2888788

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

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.

Polarization manipulation in single refractive prism based holography lithography

NASA Astrophysics Data System (ADS)

Xiong, Wenjie; Xu, Yi; Xiao, Yujian; Lv, Xiaoxu; Wu, Lijun

2015-01-01

We propose theoretically and demonstrate experimentally a simple but effective strategy for polarization manipulation in single refractive prism based holographic lithography. By tuning the polarization of a single laser beam, we can obtain the pill shape interference pattern with a high-contrast where a complex optical setup and multiple polarizers are needed in the conventional holography lithography. Fabrication of pill shape two-dimensional polymer photonic crystals using one beam and one shoot holography lithography is shown as an example to support our theoretical results. This integrated polarization manipulation technique can release the crucial stability restrictions imposed on the multiple beams holography lithography.

Structural and Kinetic Properties of the Aldehyde Dehydrogenase NahF, a Broad Substrate Specificity Enzyme for Aldehyde Oxidation.

PubMed

Coitinho, Juliana B; Pereira, Mozart S; Costa, Débora M A; Guimarães, Samuel L; Araújo, Simara S; Hengge, Alvan C; Brandão, Tiago A S; Nagem, Ronaldo A P

2016-09-27

The salicylaldehyde dehydrogenase (NahF) catalyzes the oxidation of salicylaldehyde to salicylate using NAD(+) as a cofactor, the last reaction of the upper degradation pathway of naphthalene in Pseudomonas putida G7. The naphthalene is an abundant and toxic compound in oil and has been used as a model for bioremediation studies. The steady-state kinetic parameters for oxidation of aliphatic or aromatic aldehydes catalyzed by 6xHis-NahF are presented. The 6xHis-NahF catalyzes the oxidation of aromatic aldehydes with large kcat/Km values close to 10(6) M(-1) s(-1). The active site of NahF is highly hydrophobic, and the enzyme shows higher specificity for less polar substrates than for polar substrates, e.g., acetaldehyde. The enzyme shows α/β folding with three well-defined domains: the oligomerization domain, which is responsible for the interlacement between the two monomers; the Rossmann-like fold domain, essential for nucleotide binding; and the catalytic domain. A salicylaldehyde molecule was observed in a deep pocket in the crystal structure of NahF where the catalytic C284 and E250 are present. Moreover, the residues G150, R157, W96, F99, F274, F279, and Y446 were thought to be important for catalysis and specificity for aromatic aldehydes. Understanding the molecular features responsible for NahF activity allows for comparisons with other aldehyde dehydrogenases and, together with structural information, provides the information needed for future mutational studies aimed to enhance its stability and specificity and further its use in biotechnological processes.

NaHS Protects against the Impairments Induced by Oxygen-Glucose Deprivation in Different Ages of Primary Hippocampal Neurons

PubMed Central

Yu, Qian; Wang, Binrong; Zhao, Tianzhi; Zhang, Xiangnan; Tao, Lei; Shi, Jinshan; Sun, Xude; Ding, Qian

2017-01-01

Brain ischemia leads to poor oxygen supply, and is one of the leading causes of brain damage and/or death. Neuroprotective agents are thus in great need for treatment purpose. Using both young and aged primary cultured hippocampal neurons as in vitro models, we investigated the effect of sodium hydrosulfide (NaHS), an exogenous donor of hydrogen sulfide, on oxygen-glucose deprivation (OGD) damaged neurons that mimick focal cerebral ischemia/reperfusion (I/R) induced brain injury. NaHS treatment (250 μM) protected both young and aged hippocampal neurons, as indicated by restoring number of primary dendrites by 43.9 and 68.7%, number of dendritic end tips by 59.8 and 101.1%, neurite length by 36.8 and 66.7%, and spine density by 38.0 and 58.5% in the OGD-damaged young and aged neurons, respectively. NaHS treatment inhibited growth-associated protein 43 downregulation, oxidative stress in both young and aged hippocampal neurons following OGD damage. Further studies revealed that NaHS treatment could restore ERK1/2 activation, which was inhibited by OGD-induced protein phosphatase 2 (PP2A) upregulation. Our results demonstrated that NaHS has potent protective effects against neuron injury induced by OGD in both young and aged hippocampal neurons. PMID:28326019

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.

High-speed single-pixel digital holography

NASA Astrophysics Data System (ADS)

González, Humberto; Martínez-León, Lluís.; Soldevila, Fernando; Araiza-Esquivel, Ma.; Tajahuerce, Enrique; Lancis, Jesús

2017-06-01

The complete phase and amplitude information of biological specimens can be easily determined by phase-shifting digital holography. Spatial light modulators (SLMs) based on liquid crystal technology, with a frame-rate around 60 Hz, have been employed in digital holography. In contrast, digital micro-mirror devices (DMDs) can reach frame rates up to 22 kHz. A method proposed by Lee to design computer generated holograms (CGHs) permits the use of such binary amplitude modulators as phase-modulation devices. Single-pixel imaging techniques record images by sampling the object with a sequence of micro-structured light patterns and using a simple photodetector. Our group has reported some approaches combining single-pixel imaging and phase-shifting digital holography. In this communication, we review these techniques and present the possibility of a high-speed single-pixel phase-shifting digital holography system with phase-encoded illumination. This system is based on a Mach-Zehnder interferometer, with a DMD acting as the modulator for projecting the sampling patterns on the object and also being used for phase-shifting. The proposed sampling functions are phaseencoded Hadamard patterns generated through a Lee hologram approach. The method allows the recording of the complex amplitude distribution of an object at high speed on account of the high frame rates of the DMD. Reconstruction may take just a few seconds. Besides, the optical setup is envisaged as a true adaptive system, which is able to measure the aberration induced by the optical system in the absence of a sample object, and then to compensate the wavefront in the phasemodulation stage.

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

Diagnostics and Active Control of Aircraft Interior Noise

NASA Technical Reports Server (NTRS)

Fuller, C. R.

1998-01-01

This project deals with developing advanced methods for investigating and controlling interior noise in aircraft. The work concentrates on developing and applying the techniques of Near Field Acoustic Holography (NAH) and Principal Component Analysis (PCA) to the aircraft interior noise dynamic problem. This involves investigating the current state of the art, developing new techniques and then applying them to the particular problem being studied. The knowledge gained under the first part of the project was then used to develop and apply new, advanced noise control techniques for reducing interior noise. A new fully active control approach based on the PCA was developed and implemented on a test cylinder. Finally an active-passive approach based on tunable vibration absorbers was to be developed and analytically applied to a range of test structures from simple plates to aircraft fuselages.

Fast reconstruction of a bounded ultrasonic beam using acoustically induced piezo-luminescence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kersemans, Mathias, E-mail: Mathias.Kersemans@UGent.be; Lammens, Nicolas; Degrieck, Joris

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.

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.

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.

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

Towards Holography via Quantum Source-Channel Codes.

PubMed

Pastawski, Fernando; Eisert, Jens; Wilming, Henrik

2017-07-14

While originally motivated by quantum computation, quantum error correction (QEC) is currently providing valuable insights into many-body quantum physics, such as topological phases of matter. Furthermore, mounting evidence originating from holography research (AdS/CFT) indicates that QEC should also be pertinent for conformal field theories. With this motivation in mind, we introduce quantum source-channel codes, which combine features of lossy compression and approximate quantum error correction, both of which are predicted in holography. Through a recent construction for approximate recovery maps, we derive guarantees on its erasure decoding performance from calculations of an entropic quantity called conditional mutual information. As an example, we consider Gibbs states of the transverse field Ising model at criticality and provide evidence that they exhibit nontrivial protection from local erasure. This gives rise to the first concrete interpretation of a bona fide conformal field theory as a quantum error correcting code. We argue that quantum source-channel codes are of independent interest beyond holography.

Towards Holography via Quantum Source-Channel Codes

NASA Astrophysics Data System (ADS)

Pastawski, Fernando; Eisert, Jens; Wilming, Henrik

2017-07-01

While originally motivated by quantum computation, quantum error correction (QEC) is currently providing valuable insights into many-body quantum physics, such as topological phases of matter. Furthermore, mounting evidence originating from holography research (AdS/CFT) indicates that QEC should also be pertinent for conformal field theories. With this motivation in mind, we introduce quantum source-channel codes, which combine features of lossy compression and approximate quantum error correction, both of which are predicted in holography. Through a recent construction for approximate recovery maps, we derive guarantees on its erasure decoding performance from calculations of an entropic quantity called conditional mutual information. As an example, we consider Gibbs states of the transverse field Ising model at criticality and provide evidence that they exhibit nontrivial protection from local erasure. This gives rise to the first concrete interpretation of a bona fide conformal field theory as a quantum error correcting code. We argue that quantum source-channel codes are of independent interest beyond holography.

Identification of source velocities on 3D structures in non-anechoic environments: Theoretical background and experimental validation of the inverse patch transfer functions method

NASA Astrophysics Data System (ADS)

Aucejo, M.; Totaro, N.; Guyader, J.-L.

2010-08-01

In noise control, identification of the source velocity field remains a major problem open to investigation. Consequently, methods such as nearfield acoustical holography (NAH), principal source projection, the inverse frequency response function and hybrid NAH have been developed. However, these methods require free field conditions that are often difficult to achieve in practice. This article presents an alternative method known as inverse patch transfer functions, designed to identify source velocities and developed in the framework of the European SILENCE project. This method is based on the definition of a virtual cavity, the double measurement of the pressure and particle velocity fields on the aperture surfaces of this volume, divided into elementary areas called patches and the inversion of impedances matrices, numerically computed from a modal basis obtained by FEM. Theoretically, the method is applicable to sources with complex 3D geometries and measurements can be carried out in a non-anechoic environment even in the presence of other stationary sources outside the virtual cavity. In the present paper, the theoretical background of the iPTF method is described and the results (numerical and experimental) for a source with simple geometry (two baffled pistons driven in antiphase) are presented and discussed.

Calcineurin homologous protein as an essential cofactor for Na+/H+ exchangers.

PubMed

Pang, T; Su, X; Wakabayashi, S; Shigekawa, M

2001-05-18

The Na+/H+ exchangers (NHEs) comprise a family of transporters that catalyze cell functions such as regulation of the pH and volume of a cell and epithelial absorption of Na+ and bicarbonate. Ubiquitous calcineurin B homologous protein (CHP or p22) is co-localized and co-immunoprecipitated with expressed NHE1, NHE2, or NHE3 independently of its myristoylation and Ca2+ binding, and its binding site was identified as the juxtamembrane region within the carboxyl-terminal cytoplasmic domain of exchangers. CHP binding-defective mutations of NHE1-3 or CHP depletion by injection of the competitive CHP-binding region of NHE1 into Xenopus oocytes resulted in a dramatic reduction (>90%) in the Na+/H+ exchange activity. The data suggest that CHP serves as an essential cofactor, which supports the physiological activity of NHE family members.

Identification of a 170-kDa protein associated with the vacuolar Na+/H+ antiport of Beta vulgaris.

PubMed Central

Barkla, B J; Blumwald, E

1991-01-01

The effect of the addition of amiloride to the growth medium was tested on the Na+/H+ antiport activity of tonoplast vesicles isolated from sugar beet (beta vulgaris L.) cell suspensions. Cells grown in the presence of NaCl and amiloride displayed an increased antiport activity. Analysis of the kinetic data showed that while the affinity of the antiport for Na+ ions did not change, the maximal velocity of the Na+/H+ exchange increased markedly. These results suggest the addition of more antiport molecules to the tonoplast and/or an increase in the turnover rate of the Na+/H+ exchange. The increase in activity of the antiport by the presence of amiloride was correlated with the enhanced synthesis of a tonoplast 170-kDa polypeptide. The increased synthesis of this polypeptide was detected not only upon exposure of the cells to amiloride but also when the cells were exposed to high NaCl concentrations. Polyclonal antibodies against the 170-kDa polypeptide almost completely inhibited the antiport activity. These results suggest the association of the 170-kDa polypeptide with the vacuolar Na+/H+ antiport. Images PMID:1662387

Identification of a 170-kDa protein associated with the vacuolar Na+/H+ antiport of Beta vulgaris.

PubMed

Barkla, B J; Blumwald, E

1991-12-15

The effect of the addition of amiloride to the growth medium was tested on the Na+/H+ antiport activity of tonoplast vesicles isolated from sugar beet (beta vulgaris L.) cell suspensions. Cells grown in the presence of NaCl and amiloride displayed an increased antiport activity. Analysis of the kinetic data showed that while the affinity of the antiport for Na+ ions did not change, the maximal velocity of the Na+/H+ exchange increased markedly. These results suggest the addition of more antiport molecules to the tonoplast and/or an increase in the turnover rate of the Na+/H+ exchange. The increase in activity of the antiport by the presence of amiloride was correlated with the enhanced synthesis of a tonoplast 170-kDa polypeptide. The increased synthesis of this polypeptide was detected not only upon exposure of the cells to amiloride but also when the cells were exposed to high NaCl concentrations. Polyclonal antibodies against the 170-kDa polypeptide almost completely inhibited the antiport activity. These results suggest the association of the 170-kDa polypeptide with the vacuolar Na+/H+ antiport.

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.

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.

Jak2 and Ca2+/calmodulin are key intermediates for bradykinin B2 receptor-mediated activation of Na+/H+ exchange in KNRK and CHO cells.

PubMed

Lefler, David; Mukhin, Yurii V; Pettus, Tobiah; Leeb-Lundberg, L M Fredrik; Garnovskaya, Maria N; Raymond, John R

2003-04-01

Na(+)/H(+) exchangers are ubiquitous in mammalian cells, carrying out key functions, such as cell volume defense, acid-base homeostasis, and regulation of the cytoskeleton. We used two screening technologies (FLIPR and microphysiometry) to characterize the signal transduction pathway used by the bradykinin B(2) receptor to activate Na(+)/H(+) exchange in two cell lines, KNRK and CHO. In both cell types, B(2) receptor activation resulted in rapid increases in the rate of proton extrusion that were sodium-dependent and could be blocked by the Na(+)/H(+) exchange inhibitors EIPA and MIA or by replacing extracellular sodium with TMA. Activation of Na(+)/H(+) exchange by bradykinin was concentration-dependent and could be blocked by the selective B(2) receptor antagonist HOE140, but not by the B(1) receptor antagonist des-Arg10-HOE140. Inhibitors of Jak2 tyrosine kinase (genistein and AG490) and of CAM (W-7 and calmidazolium) attenuated bradykinin-induced activation of Na(+)/H(+) exchange. Bradykinin induced formation of a complex between CAM and Jak2, supporting a regulatory role for Jak2 and CAM in the activation of Na(+)/H(+) exchange in KNRK and CHO cells. We propose that this pathway (B(2) receptor --> Jak2 --> CAM --> Na(+)/H(+) exchanger) is a fundamental regulator of Na(+)/H(+) exchange activity.

Applications of holography to condensed matter physics

NASA Astrophysics Data System (ADS)

Ross, Simon F.

2012-10-01

Holography is one of the key insights to emerge from string theory. It connects quantum gravity to field theory, and thereby provides a non-perturbative formulation of string theory. This has enabled progress on a range of theoretical issues, from the quantum description of spacetime to the calculation of scattering amplitudes in supersymmetric field theories. There have been important insights into both the field theories and the spacetime picture. More recently, applied holography has been the subject of intense and rapid development. The idea here is to use the spacetime description to address questions about strongly coupled field theory relevant to application areas such as finite-temperature QCD and condensed matter physics; the focus in this special issue is on the latter. This involves the study of field theory at finite temperature and with chemical potentials for appropriate charges, described in spacetime by charged black hole solutions. The use of holography to study these systems requires a significant extrapolation, from the field theories where classical gravitational calculations in the bulk are a useful approximation to the experimentally relevant theories. Nonetheless, the approach has had some striking qualitative successes, including the construction of holographic versions of superconducting or superfluid phase transitions, the identification of Fermi liquids with a variety of thermal behaviours, and the construction of a map between a class of gravity solutions and the hydrodynamic regime in the field theory. The use of holography provides a qualitatively new perspective on these aspects of strong coupling dynamics. In addition to insight into the behaviour of the strongly coupled field theories, this work has led to new insights into the bulk dynamics and a deeper understanding of holography. The purpose of this focus issue is to strengthen the connections between this direction and other gravitational research and to make the gravity

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.

High-resolution digital holography with the aid of coherent diffraction imaging.

PubMed

Jiang, Zhilong; Veetil, Suhas P; Cheng, Jun; Liu, Cheng; Wang, Ling; Zhu, Jianqiang

2015-08-10

The image reconstructed in ordinary digital holography was unable to bring out desired resolution in comparison to photographic materials; thus making it less preferable for many interesting applications. A method is proposed to enhance the resolution of digital holography in all directions by placing a random phase plate between the specimen and the electronic camera and then using an iterative approach to do the reconstruction. With this method, the resolution is improved remarkably in comparison to ordinary digital holography. Theoretical analysis is supported by numerical simulation. The feasibility of the method is also studied experimentally.

Multiple-wavelength neutron holography with pulsed neutrons

PubMed Central

Hayashi, Kouichi; Ohoyama, Kenji; Happo, Naohisa; Matsushita, Tomohiro; Hosokawa, Shinya; Harada, Masahide; Inamura, Yasuhiro; Nitani, Hiroaki; Shishido, Toetsu; Yubuta, Kunio

2017-01-01

Local structures around impurities in solids provide important information for understanding the mechanisms of material functions, because most of them are controlled by dopants. For this purpose, the x-ray absorption fine structure method, which provides radial distribution functions around specific elements, is most widely used. However, a similar method using neutron techniques has not yet been developed. If one can establish a method of local structural analysis with neutrons, then a new frontier of materials science can be explored owing to the specific nature of neutron scattering—that is, its high sensitivity to light elements and magnetic moments. Multiple-wavelength neutron holography using the time-of-flight technique with pulsed neutrons has great potential to realize this. We demonstrated multiple-wavelength neutron holography using a Eu-doped CaF2 single crystal and obtained a clear three-dimensional atomic image around trivalent Eu substituted for divalent Ca, revealing an interesting feature of the local structure that allows it to maintain charge neutrality. The new holography technique is expected to provide new information on local structures using the neutron technique. PMID:28835917

Multiple-wavelength neutron holography with pulsed neutrons.

PubMed

Hayashi, Kouichi; Ohoyama, Kenji; Happo, Naohisa; Matsushita, Tomohiro; Hosokawa, Shinya; Harada, Masahide; Inamura, Yasuhiro; Nitani, Hiroaki; Shishido, Toetsu; Yubuta, Kunio

2017-08-01

Local structures around impurities in solids provide important information for understanding the mechanisms of material functions, because most of them are controlled by dopants. For this purpose, the x-ray absorption fine structure method, which provides radial distribution functions around specific elements, is most widely used. However, a similar method using neutron techniques has not yet been developed. If one can establish a method of local structural analysis with neutrons, then a new frontier of materials science can be explored owing to the specific nature of neutron scattering-that is, its high sensitivity to light elements and magnetic moments. Multiple-wavelength neutron holography using the time-of-flight technique with pulsed neutrons has great potential to realize this. We demonstrated multiple-wavelength neutron holography using a Eu-doped CaF 2 single crystal and obtained a clear three-dimensional atomic image around trivalent Eu substituted for divalent Ca, revealing an interesting feature of the local structure that allows it to maintain charge neutrality. The new holography technique is expected to provide new information on local structures using the neutron technique.

Emulsions for pulsed holography: new and improved processing schemes

NASA Astrophysics Data System (ADS)

Rodin, Alexey M.; Taylor, Rob

2003-05-01

Recent improvements in the processing of commercially available holographic recording materials for pulsed holography are reviewed. Harmonics of pulsed Nd:YLF/Nd:Phosphate Glass, Nd:YLF, Nd:YAG laser's, and the fundamental wavelength of a pulsed Ruby laser were used as radiation sources for the recording of transmission and reflection holography gratings. It is shown that ultra-fine grain size materials such as PFG-03C and Ultimate-15 can be successfully applied for small and medium format pulsed holography applications. These small grain size emulsions are especially important in the areas of artistic archival portraiture and contact Denisyuk micro-holography of living objects, where noiseless image reconstruction is of a primary concern. It suggests that HOE's, such as full-color image projection screens, may be successfully recorded on PFG-03C holographic emulsions using a pulsed RGB laser. A range of commercial RGB pulsed lasers suitable for these applications are introduced. Visible wavelengths currently produced from these lasers covers the spectrum of 440 - 660nm. Latest developments of a full range of pulsed holographic camera systems manufactured by GEOLA that are suitable for medium and large format portraiture, medical imaging, museum artifact archival recording, and other types of holography are also reviewed with particular reference to new integrated digital mastering features. Finally, the initial commercial production of a new photopolymer film with a sensitivity range of 625-680nm is introduced. Initial CW exposure energies at 633nm were 30 - 50mJ/cm2; with diffraction efficiencies of 75 - 80% observed with this new material.

Salicylate and catechol levels are maintained in nahG transgenic poplar

Treesearch

Alison M. Morse; Timothy J. Tschaplinski; Christopher Dervinis; Paula M. Pijut; Eric A. Schmelz; Wendy Day; John M. Davis

2007-01-01

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

Evaluating Unsupervised Methods to Size and Classify Suspended Particles Using Digital Holography

NASA Astrophysics Data System (ADS)

Davies, E. J.; Buscombe, D.; Graham, G.; Nimmo-Smith, A.

2013-12-01

The use of digital holography to image suspended particles in-situ using submersible systems is on the ascendancy. Such systems allow visualization of the in-focus particles without the depth-of-field issues associated with conventional imaging. The size and concentration of all particles, and each individual particle, can be rapidly and automatically assessed. The automated methods by which to extract these quantities can be readily evaluated using manual measurements. These methods are not possible using instruments based on optical and acoustic (back- or forward-) scattering, so-called 'sediment surrogate' methods, which are sensitive to the bulk quantities of all suspended particles in a sample volume, and rely on mathematically inverting a measured signal to derive the property of interest. Depending on the intended application, the number of holograms required to elucidate a process could range from tens to millions. Therefore manual particle extraction is not feasible for most data-sets. This has created a pressing need among the growing community of holography users, for accurate, automated processing which is comparable in output to more well-established in-situ sizing techniques such as laser diffraction. Here we discuss the computational considerations required to focus and segment individual particles from raw digital holograms, and then size and classify these particles by type; all using unsupervised (automated) image processing. To do so, we draw upon imagery from both controlled laboratory conditions to near-shore coastal environments, using different holographic system designs, and constituting a significant variety in particle types, sizes and shapes. We evaluate the success of these techniques, and suggest directions for future developments.

Observation of double-well potential of NaH C 1Σ+ state: Deriving the dissociation energy of its ground state

NASA Astrophysics Data System (ADS)

Chu, Chia-Ching; Huang, Hsien-Yu; Whang, Thou-Jen; Tsai, Chin-Chun

2018-03-01

Vibrational levels (v = 6-42) of the NaH C 1Σ+ state including the inner and outer wells and the near-dissociation region were observed by pulsed optical-optical double resonance fluorescence depletion spectroscopy. The absolute vibrational quantum number is identified by comparing the vibrational energy difference of this experiment with the ab initio calculations. The outer well with v up to 34 is analyzed using the Dunham expansion and a Rydberg-Klein-Rees (RKR) potential energy curve is constructed. A hybrid double-well potential combined with the RKR potential, the ab initio calculation, and a long-range potential is able to describe the whole NaH C 1Σ+ state including the higher vibrational levels (v = 35-42). The dissociation energy of the NaH C 1Σ+ state is determined to be De(C) = 6595.10 ± 5 cm-1 and then the dissociation energy of the NaH ground state De(X) = 15 807.87 ± 5 cm-1 can be derived.

Pulse Holography: Review Of Applications

NASA Astrophysics Data System (ADS)

Smigielski, Paul

1990-04-01

Pulse Holography includes studies concerning time-varying phase objects as well as time-varying reflective objects involving the use of pulse ruby- and YAG-lasers. The paper is divided in two parts. One part concerns the direct use of 3-1) images reconstructed from holograms, i.e. applications to particle size analysis, 3-I) velocity measurements, 3-I) cinematography ... The second part describes applications using holographic interferometry in laboratory or in an industrial environment, i.e. applications to fluid mechanics, vibration analysis, non-destructive testing ... Recent developments including interferornetric cineholography, fiber optics, measurement of non-interferometric displacements ... , are also described. The future of holography depends to a great extent on data processing and interpretation of informations contained in holograms or holographic intericrograms. Therefore, we give the state of art in this field in Europe illustrated with some industrial applications.

Some Applications of Holography to Study Strongly Correlated Systems

NASA Astrophysics Data System (ADS)

Bhatnagar, Neha

2018-04-01

In this work, we study the transport coefficients of strongly coupled condensed matter systems using gauge/gravity duality (holography). We consider examples from the real world and evaluate the conductivities from their gravity duals. Adopting the bottom-up approach of holography, we obtain the frequency response of the conductivity for (1+1)-dimensional systems. We also evaluate the DC conductivities for non-relativistic condensed matter systems with hyperscaling violating geometry.

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.

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.

Holography: The Next Disruptive Technology

DTIC Science & Technology

2017-04-01

technological gaps that must be solved before holographic innovations can revolutionize visual deception? And, how much shorter is the timeline for...rapidly changing technological advances in holography and how it could transform the Armys in-theater tactics as well as training and communication.

Massively parallel X-ray holography

NASA Astrophysics Data System (ADS)

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

2008-09-01

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 holography as a promising but, so far, inefficient scheme to do this. We show that a uniformly redundant array 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.

Diatomic Metasurface for Vectorial Holography.

PubMed

Deng, Zi-Lan; Deng, Junhong; Zhuang, Xin; Wang, Shuai; Li, Kingfai; Wang, Yao; Chi, Yihui; Ye, Xuan; Xu, Jian; Wang, Guo Ping; Zhao, Rongkuo; Wang, Xiaolei; Cao, Yaoyu; Cheng, Xing; Li, Guixin; Li, Xiangping

2018-05-09

The emerging metasurfaces with the exceptional capability of manipulating an arbitrary wavefront have revived the holography with unprecedented prospects. However, most of the reported metaholograms suffer from limited polarization controls for a restrained bandwidth in addition to their complicated meta-atom designs with spatially variant dimensions. Here, we demonstrate a new concept of vectorial holography based on diatomic metasurfaces consisting of metamolecules formed by two orthogonal meta-atoms. On the basis of a simply linear relationship between phase and polarization modulations with displacements and orientations of identical meta-atoms, active diffraction of multiple polarization states and reconstruction of holographic images are simultaneously achieved, which is robust against both incident angles and wavelengths. Leveraging this appealing feature, broadband vectorial holographic images with spatially varying polarization states and dual-way polarization switching functionalities have been demonstrated, suggesting a new route to achromatic diffractive elements, polarization optics, and ultrasecure anticounterfeiting.

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.

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.

Contribution of the amiloride-sensitive component and the Na+/H+ exchanger to renal responsiveness to vasoconstrictors.

PubMed

Vargas, Pablo; Wangensteen, Rosemary; Rodríguez-Gómez, Isabel; Perez-Abud, Rocío; Osuna, Antonio; Quesada, Andrés; Vargas, Félix

2011-01-01

This study analyzed the role of the amiloride-sensitive component and the participation of the Na(+)/H(+) exchanger in renal responsiveness to vasoconstrictors in the isolated perfused rat kidney. The renal responses to vasoconstrictors (angiotensin II, phenylephrine, vasopressin and KCl) were studied under baseline conditions and after the administration of amiloride (10 and 100 μmol/l) or the specific Na(+)/H(+) exchange inhibitor ethylisopropylamiloride (EIPA, 10 μmol/l). The effects of amiloride and EIPA on renal responsiveness to vasoconstrictors were also analyzed in endothelium-denuded preparations. Amiloride reduced renal responsiveness to all vasoconstrictors in a dose-related manner, whereas EIPA did not affect the renal pressor response to KCl. The inhibitory effects of amiloride and EIPA on renal responsiveness to vasoconstrictors persisted after endothelium removal. These results indicate that the amiloride-sensitive component and the Na(+)/H(+) exchanger play an important role in responsiveness to the main endogenous vasoconstrictors in the renal vasculature. These results also suggest that amiloride might be useful as an inhibitor of renal vasoconstriction, even in diseases with endothelial dysfunction. Copyright © 2011 S. Karger AG, Basel.

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.

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.

In-line digital holography with phase-shifting Greek-ladder sieves

NASA Astrophysics Data System (ADS)

Xie, Jing; Zhang, Junyong; Zhang, Yanli; Zhou, Shenlei; Zhu, Jianqiang

2018-04-01

Phase shifting is the key technique in in-line digital holography, but traditional phase shifters have their own limitations in short wavelength regions. Here, phase-shifting Greek-ladder sieves with amplitude-only modulation are introduced into in-line digital holography, which are essentially a kind of diffraction lens with three-dimensional array diffraction-limited foci. In the in-line digital holographic experiment, we design two kinds of sieves by lithography and verify the validity of their phase-shifting function by measuring a 1951 U.S. Air Force resolution test target and three-dimensional array foci. With advantages of high resolving power, low cost, and no limitations at shorter wavelengths, phase-shifting Greek-ladder sieves have great potential in X-ray holography or biochemical microscopy for the next generation of synchrotron light sources.

Endoscopic digital holography for measuring flows in opaque vessels

NASA Astrophysics Data System (ADS)

Arévalo, Laura; Palero, Virginia; Lobera, Julia; Arroyo, M. Pilar

2012-10-01

In this work a new application of digital holography for the study of cardio vascular diseases is proposed. The simultaneous measurement of the blood flow velocity and the vein wall deformation can be obtained by combining digital holography and endoscopy. Endoscopes are used for the illumination and recording of digital holograms inside a vein model. Two different endoscopes have been used in different vein models in order to test the technique performance. Preliminary results of flow velocity and wall deformation are presented.

Effects of electron doping on the stability of the metal hydride NaH

NASA Astrophysics Data System (ADS)

Olea-Amezcua, M. A.; Rivas-Silva, J. F.; de la Peña-Seaman, O.; Heid, R.; Bohnen, K. P.

2017-04-01

Alkali and alkali-earth metal hydrides have high volumetric and gravimetric hydrogen densities, but due to their high thermodynamic stability, they possess high dehydrogenation temperatures which may be reduced by transforming these compounds into less stable states/configurations. We present a systematic computational study of the electron doping effects on the stability of the alkali metal hydride NaH substituted with Mg, using the self-consistent version of the virtual crystal approximation to model the alloy Na1-x Mg x H. The phonon dispersions were studied paying special attention to the crystal stability and the correlations with the electronic structure taking into account the zero point energy contribution. We found that substitution of Na by Mg in the hydride invokes a reduction of the frequencies, leading to dynamical instabilities for Mg content of 25%. The microscopic origin of these instabilities could be related to the formation of ellipsoidal Fermi surfaces centered at the L point due to the metallization of the hydride by the Mg substitution. Applying the quasiharmonic approximation, thermodynamic properties like heat capacities, vibrational entropies and vibrational free energies as a function of temperature at zero pressure are obtained. These properties determine an upper temperature for the thermodynamic stability of the hydride, which decreases from 600 K for NaH to 300 K at 20% Mg concentration. This significant reduction of the stability range indicates that dehydrogenation could be favoured by electron doping of NaH.

Femtosecond X-ray Fourier holography imaging of freeflying nanoparticles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gorkhover, Tais; Ulmer, Anatoli; Ferguson, Ken R.

Ultrafast X-ray imaging on individual fragile specimens such as aerosols1, metastable particles2, superfluid quantum systems3 and live biospecimen4 provides high resolution information, which is inaccessible with conventional imaging techniques. Coherent X-ray diffractive imag- 2 ing, however, suffers from intrinsic loss of phase, and therefore structure recovery is often complicated and not always uniquely-defined4, 5. Here, we introduce the method of in-flight holography, where we use nanoclusters as reference X-ray scatterers in order to encode relative phase information into diffraction patterns of a virus. The resulting hologram contains an unambiguous three-dimensional map of a virus and two nanoclusters with the highestmore » lateral resolution so far achieved via single shot X-ray holography. Our approach unlocks the benefits of holography for ultrafast X-ray imaging of nanoscale, non-periodic systems and paves the way to direct observation of complex electron dynamics down to the attosecond time scale.« less

Electronic Holography with a Broad Spectrum Laser for Time Gated Imaging Through Highly Scattering Media.

NASA Astrophysics Data System (ADS)

Shih, Marian Pei-Ling

The problem of optical imaging through a highly scattering volume diffuser, in particular, biological tissue, has received renewed interest in recent years because of a search for alternative imaging diagnostics in the optical wavelengths for the early detection of human breast cancer. This dissertation discusses the optical imaging of objects obscured by diffusers that contribute an otherwise overwhelming degree of multiple scatter. Many optical imaging techniques are based on the first-arriving light principle. These methods usually combine a transilluminating optical short pulse with a time windowing gate in order to form a flat shadowgraph image of absorbing objects either embedded within or hidden behind a scattering medium. The gate selectively records an image of the first-arriving light, while simultaneously rejecting the later-arriving scattered light. One set of the many implementations of the first -arriving light principle relies on the gating property of holography. This thesis presents several holographic optical gating experiments that demonstrate the role that the temporal coherence function of the illumination source plays in the imaging of all objects with short coherence length holography, with special emphasis on the application to image through diffusers and its resolution capabilities. Previous researchers have already successfully combined electronic holography, holography in which the recording medium is a two dimensional detector array instead of photographic film, with light-in-flight holography into a short coherence length holography method that images through various types of multiply scattering random media, including chicken breast tissue and wax. This thesis reports further experimental exploration of the short coherence holography method for imaging through severely scattering diffusers. There is a study on the effectiveness of spatial filtering of the first-arriving light, as well as a report of the imaging, by means of the short

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.

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

Femtosecond X-ray Fourier holography imaging of free-flying nanoparticles

NASA Astrophysics Data System (ADS)

Gorkhover, Tais; Ulmer, Anatoli; Ferguson, Ken; Bucher, Max; Maia, Filipe R. N. C.; Bielecki, Johan; Ekeberg, Tomas; Hantke, Max F.; Daurer, Benedikt J.; Nettelblad, Carl; Andreasson, Jakob; Barty, Anton; Bruza, Petr; Carron, Sebastian; Hasse, Dirk; Krzywinski, Jacek; Larsson, Daniel S. D.; Morgan, Andrew; Mühlig, Kerstin; Müller, Maria; Okamoto, Kenta; Pietrini, Alberto; Rupp, Daniela; Sauppe, Mario; van der Schot, Gijs; Seibert, Marvin; Sellberg, Jonas A.; Svenda, Martin; Swiggers, Michelle; Timneanu, Nicusor; Westphal, Daniel; Williams, Garth; Zani, Alessandro; Chapman, Henry N.; Faigel, Gyula; Möller, Thomas; Hajdu, Janos; Bostedt, Christoph

2018-03-01

Ultrafast X-ray imaging on individual fragile specimens such as aerosols1, metastable particles2, superfluid quantum systems3 and live biospecimens4 provides high-resolution information that is inaccessible with conventional imaging techniques. Coherent X-ray diffractive imaging, however, suffers from intrinsic loss of phase, and therefore structure recovery is often complicated and not always uniquely defined4,5. Here, we introduce the method of in-flight holography, where we use nanoclusters as reference X-ray scatterers to encode relative phase information into diffraction patterns of a virus. The resulting hologram contains an unambiguous three-dimensional map of a virus and two nanoclusters with the highest lateral resolution so far achieved via single shot X-ray holography. Our approach unlocks the benefits of holography for ultrafast X-ray imaging of nanoscale, non-periodic systems and paves the way to direct observation of complex electron dynamics down to the attosecond timescale.

True Color Holography with Three Wavelengths

NASA Astrophysics Data System (ADS)

Swearingen, Jeremy R.

2006-12-01

Single wavelength holography provides a three-dimensional snapshot of an object?s size, shape, and position relative to the holographic medium. However, single wavelength holography is limited because it does not preserve the integrity of the original object?s color. When the hologram is played back, the object in the hologram will appear to be the color of the wavelength used to record the hologram. This can be remedied by employing multiple wavelengths, namely three: red, blue, and green as to create a ?pseudo white? laser beam. To achieve this pseudo white beam, the red, blue, and green lasers must be merged with the appropriate dichroic filters and passed through the same spatial filter to expose the hologram as if the light was all coming from the same source. I will discuss the setup used to record these ?true color? holograms and the difficulties in developing them.

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.

Resolution factors in edgeline holography.

PubMed

Trolinger, J D; Gee, T H

1971-06-01

When an in-line Fresnel hologram of an object such as a projectile in flight is made, the reconstruction comprises an image of the outside edge of the object superimposed upon a Fresnel diffraction pattern of the edge and an unmodulated portion of the reconstruction beam. When the reconstructed image is bandpass filtered, the only remaining significant contribution is that of a diffraction pattern which is symmetrical about an edgeline gaussian image of the object. The present paper discusses the application of this type of holography in accurately locating the edge of a large dynamic object, the position of which is not accurately known in any dimension. A theoretical and experimental analysis was performed to study the effects of motion, hologram size, film type, and practical limitations upon the attainable resolution in the reconstructed image. The bandlimiting effect of motion is used to relate the motion effected resolution limit of holography to that of photography. The study shows that an edgeline can be accurately located even at high velocity normal to the edge.

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.

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.

Rainbow holography and its applications

NASA Astrophysics Data System (ADS)

Vlasov, N. G.; Ivanov, Vladimir S.

1993-09-01

The general equations of the rainbow holography are deduced. Their analysis makes it possible to offer different methods of the rainbow holographic images production. A new way of using the rainbow holograms as optical elements for effective color illuminating of transparent, specular, and polished objects is proposed. Application fields are the advertising industry, shop windows design, etc.

Proximal bicarbonate absorption independent of Na+-H+ exchange: effect of bicarbonate load.

PubMed

Bank, N; Aynedjian, H S; Mutz, B F

1989-04-01

To study proximal tubule bicarbonate absorption that is not due to the neutral Na+-H+ antiporter, mid to late proximal convolutions of the rat kidney were microperfused in vivo with a sodium-free choline solution containing 10(-3) M amiloride. The average sodium concentration resulting from sodium influx was 12 mM. At such low intraluminal [Na+], 10(-3) M amiloride should have inhibited the Na+-H+ antiporter by greater than 95%. When 25 mM HCO3- was in the perfusion fluid, measured total CO2 absorption was 100 pmol.mm-1.min-1. When luminal [HCO3-] was raised to 50 mM, and blood [HCO3-] was also raised to approximately 50 mM to avoid a transepithelial HCO3- concentration gradient, total CO2 absorption increased to greater than 300 pmol.mm-1.min-1. Thus raising intraluminal HCO3- concentration caused a marked increase in total CO2 absorption even though intraluminal [Na+] was low and amiloride was present. Control perfusions containing 140 mM Na+ yielded total CO2 absorption that was approximately 100 pmol.mm-1.min-1 higher than with the respective sodium-free perfusion solutions. In additional experiments, either DCCD or NEM was added to sodium-free perfusion solutions to inhibit H+-ATPase. These inhibitors reduced Na+-H+ independent total CO2 absorption markedly. Our observations suggest that under physiological acid-base conditions, sodium-independent H+ secretion can account for approximately 50% of total HCO3- absorption in mid to late proximal convolutions. This mechanism is stimulated by an increase in ambient HCO(-3) concentration to a degree that might account for the load-dependency of proximal HCO(-3) absorption in these segments of the proximal tubule.(ABSTRACT TRUNCATED AT 250 WORDS)

Femtosecond X-ray Fourier holography imaging of free-flying nanoparticles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gorkhover, Tais; Ulmer, Anatoli; Ferguson, Ken

Ultrafast X-ray imaging on individual fragile specimens such as aerosols, metastable particles, superfluid quantum systems and live biospecimens provides high-resolution information that is inaccessible with conventional imaging techniques. Coherent X-ray diffractive imaging, however, suffers from intrinsic loss of phase, and therefore structure recovery is often complicated and not always uniquely defined. Here in this paper, we introduce the method of in-flight holography, where we use nanoclusters as reference X-ray scatterers to encode relative phase information into diffraction patterns of a virus. The resulting hologram contains an unambiguous three-dimensional map of a virus and two nanoclusters with the highest lateral resolutionmore » so far achieved via single shot X-ray holography. Our approach unlocks the benefits of holography for ultrafast X-ray imaging of nanoscale, non-periodic systems and paves the way to direct observation of complex electron dynamics down to the attosecond timescale.« less

Femtosecond X-ray Fourier holography imaging of free-flying nanoparticles

DOE PAGES

Gorkhover, Tais; Ulmer, Anatoli; Ferguson, Ken; ...

2018-02-26

Ultrafast X-ray imaging on individual fragile specimens such as aerosols, metastable particles, superfluid quantum systems and live biospecimens provides high-resolution information that is inaccessible with conventional imaging techniques. Coherent X-ray diffractive imaging, however, suffers from intrinsic loss of phase, and therefore structure recovery is often complicated and not always uniquely defined. Here in this paper, we introduce the method of in-flight holography, where we use nanoclusters as reference X-ray scatterers to encode relative phase information into diffraction patterns of a virus. The resulting hologram contains an unambiguous three-dimensional map of a virus and two nanoclusters with the highest lateral resolutionmore » so far achieved via single shot X-ray holography. Our approach unlocks the benefits of holography for ultrafast X-ray imaging of nanoscale, non-periodic systems and paves the way to direct observation of complex electron dynamics down to the attosecond timescale.« less

Spectrally resolved digital holography using a white light LED

NASA Astrophysics Data System (ADS)

Claus, D.; Pedrini, G.; Buchta, D.; Osten, W.

2017-06-01

This paper introduces the concept of spectrally resolved digital holography. The measurement principle and the analysis of the data will be discussed in detail. The usefulness of spectrally resolved digital holography is demonstrated for colour imaging and optical metrology with regards to the recovery of modulus information and phase information, respectively. The phase information will be used to measure the shape of an object via the application of the dual wavelength method. Based on the large degree of data available, multiple speckle de-correlated dual wavelength phase maps can be obtained, which when averaged result in a signal to noise ratio improvement.

Restoration of normal pH triggers ischemia-reperfusion injury in lung by Na+/H+ exchange activation.

PubMed

Moore, T M; Khimenko, P L; Taylor, A E

1995-10-01

The effects of acidotic extracellular pH and Na+/H+ exchange inhibition on ischemia-reperfusion (I/R)-induced microvascular injury were studied in the isolated, buffer-perfused rat lung. When lungs were subjected to 45 min of ischemia followed by 30 min of reperfusion, the capillary filtration coefficient (Kfc) increased significantly, resulting in a change in Kfc (delta Kfc) of 0.360 +/- 0.09 ml.min-1.cmH2O-1.100 g-1. Addition of hydrochloric acid to the perfusate before ischemia at a concentration sufficient to reduce perfusate pH from 7.38 +/- 0.03 to 7.09 +/- 0.04 completely prevented the increase in Kfc associated with I/R (delta Kfc = 0.014 +/- 0.034 ml.min-1.cmH2O-1.100 g-1). Addition of a Na+/H+ exchange inhibitor, 5-(N,N-dimethyl)-amiloride, to the perfusate either before ischemia or at reperfusion also prevented the I/R-induced permeability increase (delta Kfc = 0.01 +/- 0.02 and -0.001 +/- 0.02 ml.min-1.cmH2O-1.100 g-1, respectively). We conclude that restoration of flow at physiological pH to the postischemic lung activates the Na+/H+ exchange system, which may represent the "triggering mechanism" responsible for initiating reperfusion-induced microvascular injury.

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

Computer Generated Holography with Intensity-Graded Patterns

PubMed Central

Conti, Rossella; Assayag, Osnath; de Sars, Vincent; Guillon, Marc; Emiliani, Valentina

2016-01-01

Computer Generated Holography achieves patterned illumination at the sample plane through phase modulation of the laser beam at the objective back aperture. This is obtained by using liquid crystal-based spatial light modulators (LC-SLMs), which modulate the spatial phase of the incident laser beam. A variety of algorithms is employed to calculate the phase modulation masks addressed to the LC-SLM. These algorithms range from simple gratings-and-lenses to generate multiple diffraction-limited spots, to iterative Fourier-transform algorithms capable of generating arbitrary illumination shapes perfectly tailored on the base of the target contour. Applications for holographic light patterning include multi-trap optical tweezers, patterned voltage imaging and optical control of neuronal excitation using uncaging or optogenetics. These past implementations of computer generated holography used binary input profile to generate binary light distribution at the sample plane. Here we demonstrate that using graded input sources, enables generating intensity graded light patterns and extend the range of application of holographic light illumination. At first, we use intensity-graded holograms to compensate for LC-SLM position dependent diffraction efficiency or sample fluorescence inhomogeneity. Finally we show that intensity-graded holography can be used to equalize photo evoked currents from cells expressing different levels of chanelrhodopsin2 (ChR2), one of the most commonly used optogenetics light gated channels, taking into account the non-linear dependence of channel opening on incident light. PMID:27799896

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 .

High-resolution terahertz inline digital holography based on quantum cascade laser

NASA Astrophysics Data System (ADS)

Deng, Qinghua; Li, Weihua; Wang, Xuemin; Li, Zeyu; Huang, Haochong; Shen, Changle; Zhan, Zhiqiang; Zou, Ruijiao; Jiang, Tao; Wu, Weidong

2017-11-01

A key requirement to put terahertz (THz) imaging systems into applications is high resolution. Based on a self-developed THz quantum cascade laser (QCL), we demonstrate a THz inline digital holography imaging system with high lateral resolution. In our case, the lateral resolution of this holography imaging system is pushed to about 70 μm, which is close to the intrinsic resolution limit of this system. To the best of our knowledge, this is much smaller than what has been reported up to now. This is attributed to a series of improvements, such as shortening the QCL wavelength, increasing Nx and Ny by the synthetic aperture method, smoothing the source beam profile, and diminishing vibration due to the cryorefrigeration device. This kind of holography system with a resolution smaller than 100 μm opens the door for many imaging experiments. It will turn the THz imaging systems into applications.

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.

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.

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.

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.

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.

Sound field separation with sound pressure and particle velocity measurements.

PubMed

Fernandez-Grande, Efren; Jacobsen, Finn; Leclère, Quentin

2012-12-01

In conventional near-field acoustic holography (NAH) it is not possible to distinguish between sound from the two sides of the array, thus, it is a requirement that all the sources are confined to only one side and radiate into a free field. When this requirement cannot be fulfilled, sound field separation techniques make it possible to distinguish between outgoing and incoming waves from the two sides, and thus NAH can be applied. In this paper, a separation method based on the measurement of the particle velocity in two layers and another method based on the measurement of the pressure and the velocity in a single layer are proposed. The two methods use an equivalent source formulation with separate transfer matrices for the outgoing and incoming waves, so that the sound from the two sides of the array can be modeled independently. A weighting scheme is proposed to account for the distance between the equivalent sources and measurement surfaces and for the difference in magnitude between pressure and velocity. Experimental and numerical studies have been conducted to examine the methods. The double layer velocity method seems to be more robust to noise and flanking sound than the combined pressure-velocity method, although it requires an additional measurement surface. On the whole, the separation methods can be useful when the disturbance of the incoming field is significant. Otherwise the direct reconstruction is more accurate and straightforward.

Linear programming phase unwrapping for dual-wavelength digital holography.

PubMed

Wang, Zhaomin; Jiao, Jiannan; Qu, Weijuan; Yang, Fang; Li, Hongru; Tian, Ailing; Asundi, Anand

2017-01-20

A linear programming phase unwrapping method in dual-wavelength digital holography is proposed and verified experimentally. The proposed method uses the square of height difference as a convergence standard and theoretically gives the boundary condition in a searching process. A simulation was performed by unwrapping step structures at different levels of Gaussian noise. As a result, our method is capable of recovering the discontinuities accurately. It is robust and straightforward. In the experiment, a microelectromechanical systems sample and a cylindrical lens were measured separately. The testing results were in good agreement with true values. Moreover, the proposed method is applicable not only in digital holography but also in other dual-wavelength interferometric techniques.

Fabrication of submicron metallic grids with interference and phase-mask holography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, Joong-Mok; Kim, Tae-Geun; Constant, Kristen

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.

Spatially and temporally resolved diagnostics of dense sprays using gated, femtosecond, digital holography

NASA Astrophysics Data System (ADS)

Trolinger, James D.; Dioumaev, Andrei K.; Ziaee, Ali; Minniti, Marco; Dunn-Rankin, Derek

2017-08-01

This paper describes research that demonstrated gated, femtosecond, digital holography, enabling 3D microscopic viewing inside dense, almost opaque sprays, and providing a new and powerful diagnostics capability for viewing fuel atomization processes never seen before. The method works by exploiting the extremely short coherence and pulse length (approximately 30 micrometers in this implementation) provided by a femtosecond laser combined with digital holography to eliminate multiple and wide angle scattered light from particles surrounding the injection region, which normally obscures the image of interest. Photons that follow a path that differs in length by more than 30 micrometers from a straight path through the field to the sensor do not contribute to the holographic recording of photons that travel in a near straight path (ballistic and "snake" photons). To further enhance the method, off-axis digital holography was incorporated to enhance signal to noise ratio and image processing capability in reconstructed images by separating the conjugate images, which overlap and interfere in conventional in-line holography. This also enables digital holographic interferometry. Fundamental relationships and limitations were also examined. The project is a continuing collaboration between MetroLaser and the University of California, Irvine.

A North American Hydroclimate Synthesis (NAHS) of the Common Era

NASA Astrophysics Data System (ADS)

Rodysill, Jessica R.; Anderson, Lesleigh; Cronin, Thomas M.; Jones, Miriam C.; Thompson, Robert S.; Wahl, David B.; Willard, Debra A.; Addison, Jason A.; Alder, Jay R.; Anderson, Katherine H.; Anderson, Lysanna; Barron, John A.; Bernhardt, Christopher E.; Hostetler, Steven W.; Kehrwald, Natalie M.; Khan, Nicole S.; Richey, Julie N.; Starratt, Scott W.; Strickland, Laura E.; Toomey, Michael R.; Treat, Claire C.; Wingard, G. Lynn

2018-03-01

This study presents a synthesis of century-scale hydroclimate variations in North America for the Common Era (last 2000 years) using new age models of previously published multiple proxy-based paleoclimate data. This North American Hydroclimate Synthesis (NAHS) examines regional hydroclimate patterns and related environmental indicators, including vegetation, lake water elevation, stream flow and runoff, cave drip rates, biological productivity, assemblages of living organisms, and salinity. Centennial-scale hydroclimate anomalies are obtained by iteratively sampling the proxy data on each of thousands of age model realizations and determining the fractions of possible time series indicating that the century-smoothed data was anomalously wet or dry relative to the 100 BCE to 1900 CE mean. Results suggest regionally asynchronous wet and dry periods over multidecadal to centennial timescales and frequent periods of extended regional drought. Most sites indicate drying during previously documented multicentennial periods of warmer Northern Hemisphere temperatures, particularly in the western U.S., central U.S., and Canada. Two widespread droughts were documented by the NAHS: from 50 BCE to 450 CE and from 800 to 1100 CE. Major hydroclimate reorganizations occurred out of sync with Northern Hemisphere temperature variations and widespread wet and dry anomalies occurred during both warm and cool periods. We present a broad assessment of paleoclimate relationships that highlights the potential influences of internal variability and external forcing and supports a prominent role for Pacific and Atlantic Ocean dynamics on century-scale continental hydroclimate.

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.

Acoustic imaging in application to reconstruction of rough rigid surface with airborne ultrasound waves

NASA Astrophysics Data System (ADS)

Krynkin, A.; Dolcetti, G.; Hunting, S.

2017-02-01

Accurate reconstruction of the surface roughness is of high importance to various areas of science and engineering. One important application of this technology is for remote monitoring of open channel flows through observing its dynamic surface roughness. In this paper a novel airborne acoustic method of roughness reconstruction is proposed and tested with a static rigid rough surface. This method is based on the acoustic holography principle and Kirchhoff approximation which make use of acoustic pressure data collected at multiple receiver points spread along an arch. The Tikhonov regularisation and generalised cross validation technique are used to solve the underdetermined system of equations for the acoustic pressures. The experimental data are collected above a roughness created with a 3D printer. For the given surface, it is shown that the proposed method works well with the various number of receiver positions. In this paper, the tested ratios between the number of surface points at which the surface elevation can be reconstructed and number of receiver positions are 2.5, 5, and 7.5. It is shown that, in a region comparable with the projected size of the main directivity lobe, the method is able to reconstruct the spatial spectrum density of the actual surface elevation with the accuracy of 20%.

Acoustic imaging in application to reconstruction of rough rigid surface with airborne ultrasound waves.

PubMed

Krynkin, A; Dolcetti, G; Hunting, S

2017-02-01

Accurate reconstruction of the surface roughness is of high importance to various areas of science and engineering. One important application of this technology is for remote monitoring of open channel flows through observing its dynamic surface roughness. In this paper a novel airborne acoustic method of roughness reconstruction is proposed and tested with a static rigid rough surface. This method is based on the acoustic holography principle and Kirchhoff approximation which make use of acoustic pressure data collected at multiple receiver points spread along an arch. The Tikhonov regularisation and generalised cross validation technique are used to solve the underdetermined system of equations for the acoustic pressures. The experimental data are collected above a roughness created with a 3D printer. For the given surface, it is shown that the proposed method works well with the various number of receiver positions. In this paper, the tested ratios between the number of surface points at which the surface elevation can be reconstructed and number of receiver positions are 2.5, 5, and 7.5. It is shown that, in a region comparable with the projected size of the main directivity lobe, the method is able to reconstruct the spatial spectrum density of the actual surface elevation with the accuracy of 20%.

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

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.

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

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

PubMed

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

2015-09-30

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. 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. 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. 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. 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 method presented already permits the study of dynamic causal interactions

High sodium intake increases HCO3− absorption in medullary thick ascending limb through adaptations in basolateral and apical Na+/H+ exchangers

PubMed Central

George, Thampi; Watts, Bruns A.

2011-01-01

A high sodium intake increases the capacity of the medullary thick ascending limb (MTAL) to absorb HCO3−. Here, we examined the role of the apical NHE3 and basolateral NHE1 Na+/H+ exchangers in this adaptation. MTALs from rats drinking H2O or 0.28 M NaCl for 5–7 days were perfused in vitro. High sodium intake increased HCO3− absorption rate by 60%. The increased HCO3− absorptive capacity was mediated by an increase in apical NHE3 activity. Inhibiting basolateral NHE1 with bath amiloride eliminated 60% of the adaptive increase in HCO3− absorption. Thus the majority of the increase in NHE3 activity was dependent on NHE1. A high sodium intake increased basolateral Na+/H+ exchange activity by 89% in association with an increase in NHE1 expression. High sodium intake increased apical Na+/H+ exchange activity by 30% under conditions in which basolateral Na+/H+ exchange was inhibited but did not change NHE3 abundance. These results suggest that high sodium intake increases HCO3− absorptive capacity in the MTAL through 1) an adaptive increase in basolateral NHE1 activity that results secondarily in an increase in apical NHE3 activity; and 2) an adaptive increase in NHE3 activity, independent of NHE1 activity. These studies support a role for NHE1 in the long-term regulation of renal tubule function and suggest that the regulatory interaction whereby NHE1 enhances the activity of NHE3 in the MTAL plays a role in the chronic regulation of HCO3− absorption. The adaptive increases in Na+/H+ exchange activity and HCO3− absorption in the MTAL may play a role in enabling the kidneys to regulate acid-base balance during changes in sodium and volume balance. PMID:21613418

Lysine 300 is essential for stability but not for electrogenic transport of the Escherichia coli NhaA Na+/H+ antiporter

PubMed Central

Călinescu, Octavian; Dwivedi, Manish; Patiño-Ruiz, Miyer; Padan, Etana; Fendler, Klaus

2017-01-01

Na+/H+ antiporters are located in the cytoplasmic and intracellular membranes and play crucial roles in regulating intracellular pH, Na+, and volume. The NhaA antiporter of Escherichia coli is the best studied member of the Na+/H+ exchanger family and a model system for all related Na+/H+ exchangers, including eukaryotic representatives. Several amino acid residues are important for the transport activity of NhaA, including Lys-300, a residue that has recently been proposed to carry one of the two H+ ions that NhaA exchanges for one Na+ ion during one transport cycle. Here, we sought to characterize the effects of mutating Lys-300 of NhaA to amino acid residues containing side chains of different polarity and length (i.e. Ala, Arg, Cys, His, Glu, and Leu) on transporter stability and function. Salt resistance assays, acridine-orange fluorescence dequenching, solid supported membrane-based electrophysiology, and differential scanning fluorometry were used to characterize Na+ and H+ transport, charge translocation, and thermal stability of the different variants. These studies revealed that NhaA could still perform electrogenic Na+/H+ exchange even in the absence of a protonatable residue at the Lys-300 position. However, all mutants displayed lower thermal stability and reduced ion transport activity compared with the wild-type enzyme, indicating the critical importance of Lys-300 for optimal NhaA structural stability and function. On the basis of these experimental data, we propose a tentative mechanism integrating the functional and structural role of Lys-300. PMID:28330875

Molecular characterization and expression analysis of the Na+/H+ exchanger gene family in Medicago truncatula

USDA-ARS?s Scientific Manuscript database

One important mechanism plants use to cope with salinity is keeping the cytosolic Na+ concentration low by sequestering Na+ in vacuoles, a process facilitated by Na+/H+ exchangers (NHX). There are eight NHX genes (NHX1 through NHX8) identified and characterized in Arabidopsis. Bioinformatic analysis...

Stückelberg formulation of holography

NASA Astrophysics Data System (ADS)

Dvali, Gia; Gomez, Cesar; Wintergerst, Nico

2016-10-01

We suggest that holography can be formulated in terms of the information capacity of the Stückelberg degrees of freedom that maintain gauge invariance of the theory in the presence of an information boundary. These Stückelbergs act as qubits that account for a certain fraction of quantum information. Their information capacity is measured by the ratio of the inverse Stückelberg energy gap to the size of the system. Systems with the smallest gap are maximally holographic. For massless gauge systems this information measure is universally equal to the inverse coupling evaluated at the systems' length scale. In this language it becomes very transparent why the Stückelberg information capacity of black holes saturates the Bekenstein bound and accounts for the entire information of the system. The physical reason is that the strength of quantum interaction is bounded from below by the gravitational coupling, which scales as area. Observing the striking similarity between the scalings of the energy gap of the boundary Stückelberg modes and the Bogoliubov modes of critical many-body systems, we establish a connection between holography and quantum criticality through the correspondence between these modes.

White-Light Optical Information Processing and Holography.

DTIC Science & Technology

1983-05-03

Processing, White-Light Holography, Image Subtraction, Image Deblurring , Coherence Requirement, Apparent Transfer Function, Source Encoding, Signal...in this period, also demonstrated several color image processing capabilities. Among those are broadband color image deblurring and color image...Broadband Image Deblurring ..... ......... 6 2.5 Color Image Subtraction ............... 7 2.6 Rainbow Holographic Aberrations . . ..... 7 2.7

Compressed digital holography: from micro towards macro

NASA Astrophysics Data System (ADS)

Schretter, Colas; Bettens, Stijn; Blinder, David; Pesquet-Popescu, Béatrice; Cagnazzo, Marco; Dufaux, Frédéric; Schelkens, Peter

2016-09-01

signal processing methods from software-driven computer engineering and applied mathematics. The compressed sensing theory in particular established a practical framework for reconstructing the scene content using few linear combinations of complex measurements and a sparse prior for regularizing the solution. Compressed sensing found direct applications in digital holography for microscopy. Indeed, the wave propagation phenomenon in free space mixes in a natural way the spatial distribution of point sources from the 3-dimensional scene. As the 3-dimensional scene is mapped to a 2-dimensional hologram, the hologram samples form a compressed representation of the scene as well. This overview paper discusses contributions in the field of compressed digital holography at the micro scale. Then, an outreach on future extensions towards the real-size macro scale is discussed. Thanks to advances in sensor technologies, increasing computing power and the recent improvements in sparse digital signal processing, holographic modalities are on the verge of practical high-quality visualization at a macroscopic scale where much higher resolution holograms must be acquired and processed on the computer.

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.

Digital Holography, a metrological tool for quantitative analysis: Trends and future applications

NASA Astrophysics Data System (ADS)

Paturzo, Melania; Pagliarulo, Vito; Bianco, Vittorio; Memmolo, Pasquale; Miccio, Lisa; Merola, Francesco; Ferraro, Pietro

2018-05-01

A review on the last achievements of Digital Holography is reported in this paper, showing that this powerful method can be a key metrological tool for the quantitative analysis and non-invasive inspection of a variety of materials, devices and processes. Nowadays, its range of applications has been greatly extended, including the study of live biological matter and biomedical applications. This paper overviews the main progresses and future perspectives of digital holography, showing new optical configurations and investigating the numerical issues to be tackled for the processing and display of quantitative data.

Solving the Mechanism of Na+/H+ Antiporters Using Molecular Dynamics Simulations

NASA Astrophysics Data System (ADS)

Dotson, David L.

Na+/H+ antiporters are vital membrane proteins for cell homeostasis, transporting Na+ ions in exchange for H+ across the lipid bilayer. In humans, dysfunction of these transporters are implicated in hypertension, heart failure, epilepsy, and autism, making them well-established drug targets. Although experimental structures for bacterial homologs of the human Na+/H+ have been obtained, the detailed mechanism for ion transport is still not well-understood. The most well-studied of these transporters, Escherichia coli NhaA, known to transport 2 H+ for every Na+ extruded, was recently shown to bind H+ and Na+ at the same binding site, for which the two ion species compete. Using molecular dynamics simulations, the work presented in this dissertation shows that Na+ binding disrupts a previously-unidentified salt bridge between two conserved residues, suggesting that one of these residues, Lys300, may participate directly in transport of H+. This work also demonstrates that the conformational change required for ion translocation in a homolog of NhaA, Thermus thermophilus NapA, thought by some to involve only small helical movements at the ion binding site, is a large-scale, rigid-body movement of the core domain relative to the dimerization domain. This elevator-like transport mechanism translates a bound Na+ up to 10 A across the membrane. These findings constitute a major shift in the prevailing thought on the mechanism of these transporters, and serve as an exciting launchpad for new developments toward understanding that mechanism in detail.

A role for Na+/H+ exchange in contraction of guinea pig airways by endothelin-1 in vitro.

PubMed

Battistini, B; Filep, J G; Cragoe, E J; Fournier, A; Sirois, P

1991-03-15

Endothelin-1-induced contractions of guinea pig tracheal and bronchial strips were dose-dependently attenuated by the amiloride analogues 5-(N-ethyl-N-isopropyl)amiloride (EIPA, 1-10 microM) and 5-(N,N-hexamethylene)amiloride (HMA, 1-10 microM). The calculated Ki values for EIPA and HMA were 0.11 +/- 0.02 microM and 0.06 +/- 0.02 microM in the trachea, and 0.28 +/- 0.11 microM and 0.70 +/- 0.25 microM in the bronchus, respectively. These values are in the same order of magnitude as those reported for inhibition of the Na+/H+ exchange in cells. Amiloride (1-10 microM) was ineffective. These data suggest that activation of the Na+/H+ exchange by ET-1 may be involved in mediating its myotropic action in guinea pig airway smooth muscle.

Improving the phase measurement by the apodization filter in the digital holography

NASA Astrophysics Data System (ADS)

Chang, Shifeng; Wang, Dayong; Wang, Yunxin; Zhao, Jie; Rong, Lu

2012-11-01

Due to the finite size of the hologram aperture in digital holography, high frequency intensity and phase fluctuations along the edges of the images, which reduce the precision of phase measurement. In this paper, the apodization filters are applied to improve the phase measurement in the digital holography. Firstly, the experimental setup of the lensless Fourier transform digital holography is built, where the sample is a standard phase grating with the grating constant of 300μm and the depth of 150nm. Then, apodization filters are applied to phase measurement of the sample with three kinds of the window functions: Tukey window, Hanning window and Blackman window, respectively. Finally, the results were compared to the detection data given by the commercial white-light interferometer. It is shown that aperture diffraction effects can be reduced by the digital apodization, and the phase measurement with the apodization is more accurate than in the unapodized case. Meanwhile, the Blackman window function produces better effect than the other two window functions in the measurement of the standard phase grating.

Integrating mass spectrometry with MD simulations reveals the role of lipids in Na+/H+ antiporters

NASA Astrophysics Data System (ADS)

Landreh, Michael; Marklund, Erik G.; Uzdavinys, Povilas; Degiacomi, Matteo T.; Coincon, Mathieu; Gault, Joseph; Gupta, Kallol; Liko, Idlir; Benesch, Justin L. P.; Drew, David; Robinson, Carol V.

2017-01-01

Na+/H+ antiporters are found in all kingdoms of life and exhibit catalysis rates that are among the fastest of all known secondary-active transporters. Here we combine ion mobility mass spectrometry and molecular dynamics simulations to study the conformational stability and lipid-binding properties of the Na+/H+ exchanger NapA from Thermus thermophilus and compare this to the prototypical antiporter NhaA from Escherichia coli and the human homologue NHA2. We find that NapA and NHA2, but not NhaA, form stable dimers and do not selectively retain membrane lipids. By comparing wild-type NapA with engineered variants, we show that the unfolding of the protein in the gas phase involves the disruption of inter-domain contacts. Lipids around the domain interface protect the native fold in the gas phase by mediating contacts between the mobile protein segments. We speculate that elevator-type antiporters such as NapA, and likely NHA2, use a subset of annular lipids as structural support to facilitate large-scale conformational changes within the membrane.

Review of digital holography reconstruction methods

NASA Astrophysics Data System (ADS)

Dovhaliuk, Rostyslav Yu.

2018-01-01

Development of digital holography opened new ways of both transparent and opaque objects non-destructive study. In this paper, a digital hologram reconstruction process is investigated. The advantages and limitations of common wave propagation methods are discussed. The details of a software implementation of a digital hologram reconstruction methods are presented. Finally, the performance of each wave propagation method is evaluated, and recommendations about possible use cases for each of them are given.

Special-purpose computer for holography HORN-2

NASA Astrophysics Data System (ADS)

Ito, Tomoyoshi; Eldeib, Hesham; Yoshida, Kenji; Takahashi, Shinya; Yabe, Takashi; Kunugi, Tomoaki

1996-01-01

We designed and built a special-purpose computer for holography, HORN-2 (HOlographic ReconstructioN). HORN-2 calculates light intensity at high speed of 0.3 Gflops per one board with single (32-bit floating point) precision. The cost of the board is 500 000 Japanese yen (5000 US dollar). We made three boards. Operating them in parallel, we get about 1 Gflops.

Lifetimes and energetics of the first electronically excited states of NaH2O from time-resolved photoelectron imaging

NASA Astrophysics Data System (ADS)

Gartmann, Thomas E.; Yoder, Bruce L.; Chasovskikh, Egor; Signorell, Ruth

2017-09-01

The energetics and lifetimes of the first electronically excited states (;3p-states;) of NaH2O and NaD2O have been measured by pump-probe (740/780 and 400 nm) photoelectron imaging. The photoelectron spectra of NaH2O show two bands at an electron kinetic energy of 0.14 and 0.38 eV, respectively. We assign the former to excitation via the two energetically close lying ;pπ-states; with flat potential curves in the intermolecular degrees of freedom, and the latter to the excitation via the ;pσ-state; characterized by significantly steeper potential curves. The relaxation of all ;p-states; follows a double exponential decay with a lifetime around 110 ps for the dominant fast component.

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

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

Characteristics of mist 3D screen for projection type electro-holography

NASA Astrophysics Data System (ADS)

Sato, Koki; Okumura, Toshimichi; Kanaoka, Takumi; Koizumi, Shinya; Nishikawa, Satoko; Takano, Kunihiko

2006-01-01

The specification of hologram image is the full parallax 3D image. In this case we can get more natural 3D image because focusing and convergence are coincident each other. We try to get practical electro-holography system because for conventional electro-holography the image viewing angle is very small. This is due to the limited display pixel size. Now we are developing new method for large viewing angle by space projection method. White color laser is irradiated to single DMD panel (time shared CGH of RGB three colors). 3D space screen constructed by very small water particle is used to reconstruct the 3D image with large viewing angle by scattering of water particle.

Referenceless Phase Holography for 3D Imaging

NASA Astrophysics Data System (ADS)

Kreis, Thomas

2017-12-01

Referenceless phase holography generates the full (amplitude and phase) optical field if intensity and phase of this field are given as numerical data. It is based on the interference of two pure phase fields which are produced by reflection of two mutually coherent plane waves at two phase modulating spatial light modulators of the liquid crystal on silicon type. Thus any optical field of any real or artificial 3D scene can be displayed. This means that referenceless phase holography is a promising method for future 3D imaging, e. g. in 3D television. The paper introduces the theory of the method and presents three possible interferometer arrangements, for the first time the Mach-Zehnder and the grating interferometer adapted to this application. The possibilities and problems in calculating the diffraction fields of given 3D scenes are worked out, the best choice and modifications of the algorithms are given. Several novelty experimental examples are given proving the 3D cues depth of field, occlusion and parallax. The benefits and advantages over other holographic approaches are pointed out, open problems and necessary technological developments as well as possibilities and future prospects are discussed.

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

When holography meets coherent diffraction imaging.

PubMed

Latychevskaia, Tatiana; Longchamp, Jean-Nicolas; Fink, Hans-Werner

2012-12-17

The phase problem is inherent to crystallographic, astronomical and optical imaging where only the intensity of the scattered signal is detected and the phase information is lost and must somehow be recovered to reconstruct the object's structure. Modern imaging techniques at the molecular scale rely on utilizing novel coherent light sources like X-ray free electron lasers for the ultimate goal of visualizing such objects as individual biomolecules rather than crystals. Here, unlike in the case of crystals where structures can be solved by model building and phase refinement, the phase distribution of the wave scattered by an individual molecule must directly be recovered. There are two well-known solutions to the phase problem: holography and coherent diffraction imaging (CDI). Both techniques have their pros and cons. In holography, the reconstruction of the scattered complex-valued object wave is directly provided by a well-defined reference wave that must cover the entire detector area which often is an experimental challenge. CDI provides the highest possible, only wavelength limited, resolution, but the phase recovery is an iterative process which requires some pre-defined information about the object and whose outcome is not always uniquely-defined. Moreover, the diffraction patterns must be recorded under oversampling conditions, a pre-requisite to be able to solve the phase problem. Here, we report how holography and CDI can be merged into one superior technique: holographic coherent diffraction imaging (HCDI). An inline hologram can be recorded by employing a modified CDI experimental scheme. We demonstrate that the amplitude of the Fourier transform of an inline hologram is related to the complex-valued visibility, thus providing information on both, the amplitude and the phase of the scattered wave in the plane of the diffraction pattern. With the phase information available, the condition of oversampling the diffraction patterns can be relaxed, and the

Photolabeling of tonoplast from sugar beet cell suspensions by [h]5-(N-methyl-N-isobutyl)-amiloride, an inhibitor of the vacuolar na/h antiport.

PubMed

Barkla, B J; Charuk, J H; Cragoe, E J; Blumwald, E

1990-07-01

The effects of 5-(N-methyl-N-isobutyl)-amiloride (MIA), an amiloride analog, was tested on the Na(+)/H(+) antiport activity of intact vacuoles and tonoplast vesicles isolated from sugar beet (Beta vulgaris L.) cell suspension cultures. MIA inhibited Na(+)/H(+) exchange in a competitive manner with a K(i) of 2.5 and 5.9 micromolar for DeltapH-dependent (22)Na(+) influx in tonoplast vesicles and Na(+)-dependent H(+) efflux in intact vacuoles, respectively. Scatchard analysis of the binding of [(3)H]MIA to tonoplast membranes revealed a high affinity binding component with a K(d) of 1.3 micromolar. The close relationship between the dissociation constant value obtained and the constants of inhibition for MIA obtained by fluorescence quenching and isotope exchange suggests that the high affinity component represents a class of sites associated with the tonoplast Na(+)/H(+) antiport. Photolabeling of the tonoplast with [(3)H]MIA revealed two sets of polypeptides with a different affinity to amiloride and its analog.

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

Application of comparative digital holography for distant shape control

NASA Astrophysics Data System (ADS)

Baumbach, Torsten; Osten, Wolfgang; von Kopylow, Christoph; Juptner, Werner P. O.

2004-09-01

The comparison of two objects is of great importance in the industrial production process. Especially comparing the shape is of particular interest for maintaining calibration tools or controlling the tolerance in the deviation between a sample and a master. Outsourcing and globalization of production places can result in large distances between co-operating partners and might cause problems for maintaining quality standards. Consequently new challenges arise for optical measurement techniques especially in the field of industrial shape control. In this paper we describe the progress of implementing a novel technique for comparing directly two objects with different microstructure. The technique is based on the combination of comparative holography and digital holography. Comparing the objects can be done in two ways. One is the digital comparison in the computer and the other way is by using the analogue reconstruction of a master hologram with a spatial light modulator (SLM) as coherent mask for illuminating the test object. Since this mask is stored digitally it can be transmitted via telecommunication networks and this enables the access to the full optical information of the master object at any place wanted. Beside the basic principle of comparative digital holography (CDH), we will show in this paper the set-up for doing the analogue comparison of two objects with increased sensitivity in comparison to former measurements and the calibration of the SLM that is used for the experiments. We will give examples for the digital and the analogue comparison of objects including a verification of our results by another optical measurement technique.

Holography and noncommutative yang-mills theory

PubMed

Li; Wu

2000-03-06

In this Letter a recently proposed gravity dual of noncommutative Yang-Mills theory is derived from the relations between closed string moduli and open string moduli recently suggested by Seiberg and Witten. The only new input one needs is a simple form of the running string tension as a function of energy. This derivation provides convincing evidence that string theory integrates with the holographical principle and demonstrates a direct link between noncommutative Yang-Mills theory and holography.

Response of the human tympanic membrane to transient acoustic and mechanical stimuli: Preliminary results.

PubMed

Razavi, Payam; Ravicz, Michael E; Dobrev, Ivo; Cheng, Jeffrey Tao; Furlong, Cosme; Rosowski, John J

2016-10-01

The response of the tympanic membrane (TM) to transient environmental sounds and the contributions of different parts of the TM to middle-ear sound transmission were investigated by measuring the TM response to global transients (acoustic clicks) and to local transients (mechanical impulses) applied to the umbo and various locations on the TM. A lightly-fixed human temporal bone was prepared by removing the ear canal, inner ear, and stapes, leaving the incus, malleus, and TM intact. Motion of nearly the entire TM was measured by a digital holography system with a high speed camera at a rate of 42 000 frames per second, giving a temporal resolution of <24 μs for the duration of the TM response. The entire TM responded nearly instantaneously to acoustic transient stimuli, though the peak displacement and decay time constant varied with location. With local mechanical transients, the TM responded first locally at the site of stimulation, and the response spread approximately symmetrically and circumferentially around the umbo and manubrium. Acoustic and mechanical transients provide distinct and complementary stimuli for the study of TM response. Spatial variations in decay and rate of spread of response imply local variations in TM stiffness, mass, and damping. Copyright © 2016 Elsevier B.V. All rights reserved.

Response of the human tympanic membrane to transient acoustic and mechanical stimuli: Preliminary results

PubMed Central

Razavi, Payam; Ravicz, Michael E.; Dobrev, Ivo; Cheng, Jeffrey Tao; Furlong, Cosme; Rosowski, John J.

2016-01-01

The response of the tympanic membrane (TM) to transient environmental sounds and the contributions of different parts of the TM to middle-ear sound transmission were investigated by measuring the TM response to global transients (acoustic clicks) and to local transients (mechanical impulses) applied to the umbo and various locations on the TM. A lightly-fixed human temporal bone was prepared by removing the ear canal, inner ear, and stapes, leaving the incus, malleus, and TM intact. Motion of nearly the entire TM was measured by a digital holography system with a high speed camera at a rate of 42 000 frames per second, giving a temporal resolution of <24 μs for the duration of the TM response. The entire TM responded nearly instantaneously to acoustic transient stimuli, though the peak displacement and decay time constant varied with location. With local mechanical transients, the TM responded first locally at the site of stimulation, and the response spread approximately symmetrically and circumferentially around the umbo and manubrium. Acoustic and mechanical transients provide distinct and complementary stimuli for the study of TM response. Spatial variations in decay and rate of spread of response imply local variations in TM stiffness, mass, and damping. PMID:26880098

Simulations and experiments on vibration damping for zoom-holography and nano-scanning at the GINIX

NASA Astrophysics Data System (ADS)

Osterhoff, Markus; Luley, Peter; Sprung, Michael; Salditt, Tim

2017-09-01

The Göttingen Instrument for Nano-Imaging with X-ray (GINIX) is a holography endstation located at the P10 coherence beamline at PETRA III, designed and operated by the University of Göttingen in close collaboration with DESY Photon science Hamburg [1-2]. GINIX is designed as a waveguide based holography experiment with a Kirkpatrick-Baez nanofocus. Its versatility has stimulated a great manifold of imaging modalities. Today, users choose the GINIX setup not only for its few nm coherent waveguide beams (e.g. for ptychography or holography), but also to carry out scanning SAXS measurements to probe local anisotropies with sub-micron real-space and even higher reciprocal space resolution. In addition, it is possible to combine different detectors for e.g. simultaneous SAXS/WAXS and fluorescence measurements [3]. We summarise our ongoing efforts to reduce vibrations in the setup, and present latest experimental results obtained with GINIX, focusing on the unique capabilities offered by its versatile and flexible design. The overview includes results from different imaging schemes such as waveguide based zoom-tomography and user examples in WAXS geometry. We show how to correlate complementary techniques like holography and scanning SAXS and present first results obtained using a new fast sample scanner for Multilayer Zone Plate imaging..

Unraveling nonadiabatic ionization and Coulomb potential effect in strong-field photoelectron holography.

PubMed

Song, Xiaohong; Lin, Cheng; Sheng, Zhihao; Liu, Peng; Chen, Zhangjin; Yang, Weifeng; Hu, Shilin; Lin, C D; Chen, Jing

2016-06-22

Strong field photoelectron holography has been proposed as a means for interrogating the spatial and temporal information of electrons and ions in a dynamic system. After ionization, part of the electron wave packet may directly go to the detector (the reference wave), while another part may be driven back and scatters off the ion(the signal wave). The interference hologram of the two waves may be used to extract target information embedded in the collision process. Unlike conventional optical holography, however, propagation of the electron wave packet is affected by the Coulomb potential as well as by the laser field. In addition, electrons are emitted over the whole laser pulse duration, thus multiple interferences may occur. In this work, we used a generalized quantum-trajectory Monte Carlo method to investigate the effect of Coulomb potential and the nonadiabatic subcycle ionization on the photoelectron hologram. We showed that photoelectron hologram can be well described only when the effect of nonadiabatic ionization is accounted for, and Coulomb potential can be neglected only in the tunnel ionization regime. Our results help paving the way for establishing photoelectron holography for probing spatial and dynamic properties of atoms and molecules.

Unraveling nonadiabatic ionization and Coulomb potential effect in strong-field photoelectron holography

PubMed Central

Song, Xiaohong; Lin, Cheng; Sheng, Zhihao; Liu, Peng; Chen, Zhangjin; Yang, Weifeng; Hu, Shilin; Lin, C. D.; Chen, Jing

2016-01-01

Strong field photoelectron holography has been proposed as a means for interrogating the spatial and temporal information of electrons and ions in a dynamic system. After ionization, part of the electron wave packet may directly go to the detector (the reference wave), while another part may be driven back and scatters off the ion(the signal wave). The interference hologram of the two waves may be used to extract target information embedded in the collision process. Unlike conventional optical holography, however, propagation of the electron wave packet is affected by the Coulomb potential as well as by the laser field. In addition, electrons are emitted over the whole laser pulse duration, thus multiple interferences may occur. In this work, we used a generalized quantum-trajectory Monte Carlo method to investigate the effect of Coulomb potential and the nonadiabatic subcycle ionization on the photoelectron hologram. We showed that photoelectron hologram can be well described only when the effect of nonadiabatic ionization is accounted for, and Coulomb potential can be neglected only in the tunnel ionization regime. Our results help paving the way for establishing photoelectron holography for probing spatial and dynamic properties of atoms and molecules. PMID:27329071

Holography and thermalization in optical pump-probe spectroscopy

NASA Astrophysics Data System (ADS)

Bagrov, A.; Craps, B.; Galli, F.; Keränen, V.; Keski-Vakkuri, E.; Zaanen, J.

2018-04-01

Using holography, we model experiments in which a 2 +1 D strange metal is pumped by a laser pulse into a highly excited state, after which the time evolution of the optical conductivity is probed. We consider a finite-density state with mildly broken translation invariance and excite it by oscillating electric field pulses. At zero density, the optical conductivity would assume its thermalized value immediately after the pumping has ended. At finite density, pulses with significant dc components give rise to slow exponential relaxation, governed by a vector quasinormal mode. In contrast, for high-frequency pulses the amplitude of the quasinormal mode is strongly suppressed, so that the optical conductivity assumes its thermalized value effectively instantaneously. This surprising prediction may provide a stimulus for taking up the challenge to realize these experiments in the laboratory. Such experiments would test a crucial open question faced by applied holography: are its predictions artifacts of the large N limit or do they enjoy sufficient UV independence to hold at least qualitatively in real-world systems?

The Impact of a New Speckle Holography Analysis on the Galactic Center Orbits Initiative

NASA Astrophysics Data System (ADS)

Mangian, John; Ghez, Andrea; Gautam, Abhimat; Gallego, Laly; Schödel, Rainer; Lu, Jessica; Chen, Zhuo; UCLA Galactic Center Group; W.M. Keck Observatory Staff

2018-01-01

The Galactic Center Orbit Initiative has used two decades of high angular resolution imaging data from the W. M. Keck Observatory to make astrometric measurements of stellar motion around our Galaxy's central supermassive black hole. We present an analysis of a new approach to ten years of speckle imaging data (1995 - 2005) that has been processed with a new holography analysis. This analysis has (1) improved the image quality near the edge of the combined speckle frame and (2) increased the depth of the images and therefore increased the number of sources detected throughout the entire image. By directly comparing each holography analysis, we find a 41% increase in total detected sources and a 81% increase in sources further than 3" from the central black hole (SgrA*). Further, we find a 49% increase in sources of K-band magnitude greater than the old holography limiting magnitude due to the reduction of light halos surrounding bright sources.

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.

Coaxial digital holography measures particular matter in cloud and ambient atmosphere

NASA Astrophysics Data System (ADS)

Li, Baosheng; Yu, Haonan; Jia, Yizhen; Tao, Xiaojie; Zhang, Yang

2018-02-01

In the artificially affected weather, the detection of cloud droplets particles provides an important reference for the effective impact of artificial weather. Digital holography has the unique advantages of full-field, non-contact, no damage, real-time and quantification. In this paper, coaxial digital holography is used to record the polyethylene standard particles and aluminum scrap, and some important parameters, such as three-dimensional coordinate spatial distribution and particle size, will be obtained by the means of analyzing the digital hologram of the particle. The experimental results verify the feasibility of the coaxial digital holographic device applied to the measurement of the cloud parameters, and complete the construction of the coaxial digital holographic system and the measurement of the particles.

Molecular analysis of the Na+/H+ exchanger gene family and its role in salt stress in Medicago truncatula

USDA-ARS?s Scientific Manuscript database

High salinity in irrigation water is detrimental to plant growth and productivity. Plants develop various mechanisms and strategies to cope with salinity. One important mechanism is keeping the cytosolic Na+ concentration low by sequestering Na+ in vacuoles, a process facilitated by Na+/H+ exchanger...

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

Electric radiation mapping of silver/zinc oxide nanoantennas by using electron holography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sanchez, J. E.; Mendoza-Santoyo, F.; Cantu-Valle, J.

2015-01-21

In this work, we report the fabrication of self-assembled zinc oxide nanorods grown on pentagonal faces of silver nanowires by using microwaves irradiation. The nanostructures resemble a hierarchal nanoantenna and were used to study the far and near field electrical metal-semiconductor behavior from the electrical radiation pattern resulting from the phase map reconstruction obtained using off-axis electron holography. As a comparison, we use electric numerical approximations methods for a finite number of ZnO nanorods on the Ag nanowires and show that the electric radiation intensities maps match closely the experimental results obtained with electron holography. The time evolution of themore » radiation pattern as generated from the nanostructure was recorded under in-situ radio frequency signal stimulation, in which the generated electrical source amplitude and frequency were varied from 0 to 5 V and from 1 to 10 MHz, respectively. The phase maps obtained from electron holography show the change in the distribution of the electric radiation pattern for individual nanoantennas. The mapping of this electrical behavior is of the utmost importance to gain a complete understanding for the metal-semiconductor (Ag/ZnO) heterojunction that will help to show the mechanism through which these receiving/transmitting structures behave at nanoscale level.« less

Unraveling nonadiabatic ionization and Coulomb potential effect in strong-field photoelectron holography

DOE PAGES

Song, Xiaohong; Lin, Cheng; Sheng, Zhihao; ...

2016-06-22

Strong field photoelectron holography has been proposed as a means for interrogating the spatial and temporal information of electrons and ions in a dynamic system. After ionization, part of the electron wave packet may directly go to the detector (the reference wave), while another part may be driven back and scatters off the ion(the signal wave). The interference hologram of the two waves may be used to extract target information embedded in the collision process. Unlike conventional optical holography, however, propagation of the electron wave packet is affected by the Coulomb potential as well as by the laser field. Inmore » addition, electrons are emitted over the whole laser pulse duration, thus multiple interferences may occur. In this work, we used a generalized quantum-trajectory Monte Carlo method to investigate the effect of Coulomb potential and the nonadiabatic subcycle ionization on the photoelectron hologram. Here, we showed that photoelectron hologram can be well described only when the effect of nonadiabatic ionization is accounted for, and Coulomb potential can be neglected only in the tunnel ionization regime. Our results help paving the way for establishing photoelectron holography for probing spatial and dynamic properties of atoms and molecules.« less

Holography as a tool for widespread industrial applications: analysis and comments

NASA Astrophysics Data System (ADS)

Smigielski, Paul

1991-10-01

During the last national meeting of the Holographic Club of the French Optical Society held at SAUMUR, 22-23 November 1990, on `Vibration analysis with the help of holographic and associated methods,' more than 80% of attendees were industrialists. Some scientists who specialized in coherent optics said that it is not necessary to be an optician to use holography in the industry. That means that veritable progress has been achieved since the discovery of holographic interferometry in 1965. But, on the other hand, too few industrialists use holographic techniques. This paper critically examines the evolution of holographic interferometry through concrete examples and shows that hopes of industrial uses of holography are more credible today than yesterday because of new developments expected in hardwares (lasers, recording materials, etc.) and softwares.

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.

Deep-turbulence wavefront sensing using digital holography in the on-axis phase shifting recording geometry

NASA Astrophysics Data System (ADS)

Thornton, Douglas E.; Spencer, Mark F.; Perram, Glen P.

2017-09-01

The effects of deep turbulence in long-range imaging applications presents unique challenges to properly measure and correct for aberrations incurred along the atmospheric path. In practice, digital holography can detect the path-integrated wavefront distortions caused by deep turbulence, and di erent recording geometries offer different benefits depending on the application of interest. Previous studies have evaluated the performance of the off-axis image and pupil plane recording geometries for deep-turbulence sensing. This study models digital holography in the on-axis phase shifting recording geometry using wave optics simulations. In particular, the analysis models spherical-wave propagation through varying deep-turbulence conditions to estimate the complex optical field, and performance is evaluated by calculating the field-estimated Strehl ratio and RMS wavefront error. Altogether, the results show that digital holography in the on-axis phase shifting recording geometry is an effective wavefront-sensing method in the presence of deep turbulence.

3D motion picture of transparent gas flow by parallel phase-shifting digital holography

NASA Astrophysics Data System (ADS)

Awatsuji, Yasuhiro; Fukuda, Takahito; Wang, Yexin; Xia, Peng; Kakue, Takashi; Nishio, Kenzo; Matoba, Osamu

2018-03-01

Parallel phase-shifting digital holography is a technique capable of recording three-dimensional (3D) motion picture of dynamic object, quantitatively. This technique can record single hologram of an object with an image sensor having a phase-shift array device and reconstructs the instantaneous 3D image of the object with a computer. In this technique, a single hologram in which the multiple holograms required for phase-shifting digital holography are multiplexed by using space-division multiplexing technique pixel by pixel. We demonstrate 3D motion picture of dynamic and transparent gas flow recorded and reconstructed by the technique. A compressed air duster was used to generate the gas flow. A motion picture of the hologram of the gas flow was recorded at 180,000 frames/s by parallel phase-shifting digital holography. The phase motion picture of the gas flow was reconstructed from the motion picture of the hologram. The Abel inversion was applied to the phase motion picture and then the 3D motion picture of the gas flow was obtained.

Computer-based analysis of holography using ray tracing.

PubMed

Latta, J N

1971-12-01

The application of a ray-tracing methodology to holography is presented. Emphasis is placed on establishing a very general foundation from which to build a general computer-based implementation. As few restrictions as possible are placed on the recording and reconstruction geometry. The necessary equations are established from the construction and reconstruction parameters of the hologram. The aberrations are defined following H. H. Hopkins, and these aberration specification techniques are compared with those used previously to analyze holography. Representative of the flexibility of the ray-tracing approach, two examples are considered. The first compares the answers between a wavefront matching and the ray-tracing analysis in the case of aberration balancing to compensate for chromatic aberrations. The results are very close and establish the basic utility of aberration balancing. Further indicative of the power of a ray tracing, a thick media analysis is included in the computer programs. This section is then used to perform a study of the effects of hologram emulsion shrinkage and methods for compensation. The results of compensating such holograms are to introduce aberrations, and these are considered in both reflection and transmission holograms.

A Preliminary Comparison of Three Dimensional Particle Tracking and Sizing using Plenoptic Imaging and Digital In-line Holography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guildenbecher, Daniel Robert; Munz, Elise Dahnke; Farias, Paul Abraham

2015-12-01

Digital in-line holography and plenoptic photography are two techniques for single-shot, volumetric measurement of 3D particle fields. Here we present a preliminary comparison of the two methods by applying plenoptic imaging to experimental configurations that have been previously investigated with digital in-line holography. These experiments include the tracking of secondary droplets from the impact of a water drop on a thin film of water and tracking of pellets from a shotgun. Both plenoptic imaging and digital in-line holography successfully quantify the 3D nature of these particle fields. This includes measurement of the 3D particle position, individual particle sizes, and three-componentmore » velocity vectors. For the initial processing methods presented here, both techniques give out-of-plane positional accuracy of approximately 1-2 particle diameters. For a fixed image sensor, digital holography achieves higher effective in-plane spatial resolutions. However, collimated and coherent illumination makes holography susceptible to image distortion through index of refraction gradients, as demonstrated in the shotgun experiments. On the other hand, plenotpic imaging allows for a simpler experimental configuration. Furthermore, due to the use of diffuse, white-light illumination, plenoptic imaging is less susceptible to image distortion in the shotgun experiments. Additional work is needed to better quantify sources of uncertainty, particularly in the plenoptic experiments, as well as develop data processing methodologies optimized for the plenoptic measurement.« less

Na+/H+ and Na+/NH4+ exchange activities of zebrafish NHE3b expressed in Xenopus oocytes

PubMed Central

Ito, Yusuke; Kato, Akira; Hirata, Taku; Hirose, Shigehisa

2014-01-01

Zebrafish Na+/H+ exchanger 3b (zNHE3b) is highly expressed in the apical membrane of ionocytes where Na+ is absorbed from ion-poor fresh water against a concentration gradient. Much in vivo data indicated that zNHE3b is involved in Na+ absorption but not leakage. However, zNHE3b-mediated Na+ absorption has not been thermodynamically explained, and zNHE3b activity has not been measured. To address this issue, we overexpressed zNHE3b in Xenopus oocytes and characterized its activity by electrophysiology. Exposure of zNHE3b oocytes to Na+-free media resulted in significant decrease in intracellular pH (pHi) and intracellular Na+ activity (aNai). aNai increased significantly when the cytoplasm was acidified by media containing CO2-HCO3− or butyrate. Activity of zNHE3b was inhibited by amiloride or 5-ethylisopropyl amiloride (EIPA). Although the activity was accompanied by a large hyperpolarization of ∼50 mV, voltage-clamp experiments showed that Na+/H+ exchange activity of zNHE3b is electroneutral. Exposure of zNHE3b oocytes to medium containing NH3/NH4+ resulted in significant decreases in pHi and aNai and significant increase in intracellular NH4+ activity, indicating that zNHE3b mediates the Na+/NH4+ exchange. In low-Na+ (0.5 mM) media, zNHE3b oocytes maintained aNai of 1.3 mM, and Na+-influx was observed when pHi was decreased by media containing CO2-HCO3− or butyrate. These results provide thermodynamic evidence that zNHE3b mediates Na+ absorption from ion-poor fresh water by its Na+/H+ and Na+/NH4+ exchange activities. PMID:24401990

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.

Bi-local holography in the SYK model

DOE PAGES

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. Lastly, 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.

Setup calibration and optimization for comparative digital holography

NASA Astrophysics Data System (ADS)

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

2004-08-01

With increasing globalization many enterprises decide to produce the components of their products at different locations all over the world. Consequently, new technologies and strategies for quality control are required. In this context the remote comparison of objects with regard to their shape or response on certain loads is getting more and more important for a variety of applications. For such a task the novel method of comparative digital holography is a suitable tool with interferometric sensitivity. With this technique the comparison in shape or deformation of two objects does not require the presence of both objects at the same place. In contrast to the well known incoherent techniques based on inverse fringe projection this new approach uses a coherent mask for the illumination of the sample object. The coherent mask is created by digital holography to enable the instant access to the complete optical information of the master object at any wanted place. The reconstruction of the mask is done by a spatial light modulator (SLM). The transmission of the digital master hologram to the place of comparison can be done via digital telecommunication networks. Contrary to other interferometric techniques this method enables the comparison of objects with different microstructure. In continuation of earlier reports our investigations are focused here on the analysis of the constraints of the setup with respect to the quality of the hologram reconstruction with a spatial light modulator. For successful measurements the selection of the appropriate reconstruction method and the adequate optical set-up is mandatory. In addition, the use of a SLM for the reconstruction requires the knowledge of its properties for the accomplishment of this method. The investigation results for the display properties such as display curvature, phase shift and the consequences for the technique will be presented. The optimization and the calibration of the set-up and its components lead

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

NASA Astrophysics Data System (ADS)

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.

Top-quality security optical elements: from holography towards 500.000 dpi

NASA Astrophysics Data System (ADS)

Kotačka, Libor; Těthal, Tomas; Kolařík, Vladimir

2005-09-01

Invented in late 1940s, holography has played a very important role in many technical applications. While the 60s and 70s belonged to, say, a classical period of the holography and diffractive optics (optical elements, lenses, beam splitters), the last two decades have shown an enormous expansion of various mainly synthetically designed and created holographic elements. Ever since its invention, holograms have also attracted our attention, because of their true three-dimension perception of a depicted object and related optical features. These phenomena caused, the holograms have become very well and easily publicly recognized, but still very difficult to falsify. Holography based optically variable microstructures and related advanced anti-counterfeit measures are thus ones of the leading features in security elements used for the protection against falsification of valuables, documents (banknotes, visa, passports, ID cards, tax stamps, etc.), serving for the protection of interests and many others. Our talk deals with the survey of currently exploited technologies to produce several protective optical elements. A special attention will be paid to the synthetically developed special optical elements by means of the unique technology - the electron beam lithography, what is one of the world's most advanced technologies used for the protection against falsification. The computer-synthesized security elements are recorded with an incredible resolution of up to 500.000 dpi and are specially developed for the security of the most important state valuables and documents. Finally, we shall discuss some technological possibilities for its future development.

Holographic data visualization: using synthetic full-parallax holography to share information

NASA Astrophysics Data System (ADS)

Dalenius, Tove N.; Rees, Simon; Richardson, Martin

2017-03-01

This investigation explores representing information through data visualization using the medium holography. It is an exploration from the perspective of a creative practitioner deploying a transdisciplinary approach. The task of visualizing and making use of data and "big data" has been the focus of a large number of research projects during the opening of this century. As the amount of data that can be gathered has increased in a short time our ability to comprehend and get meaning out of the numbers has been brought into attention. This project is looking at the possibility of employing threedimensional imaging using holography to visualize data and additional information. To explore the viability of the concept, this project has set out to transform the visualization of calculated energy and fluid flow data to a holographic medium. A Computational Fluid Dynamics (CFD) model of flow around a vehicle, and a model of Solar irradiation on a building were chosen to investigate the process. As no pre-existing software is available to directly transform the data into a compatible format the team worked collaboratively and transdisciplinary in order to achieve an accurate conversion from the format of the calculation and visualization tools to a configuration suitable for synthetic holography production. The project also investigates ideas for layout and design suitable for holographic visualization of energy data. Two completed holograms will be presented. Future possibilities for developing the concept of Holographic Data Visualization are briefly deliberated upon.

Preliminary Design of a Digital Holography PFC Erosion Diagnostic for MPEX

NASA Astrophysics Data System (ADS)

Thomas, C. E. (Tommy), Jr.; Biewer, T. M.; Shaw, G. C.; Baylor, L. R.; Combs, S. K.; Meitner, S. J.; Rapp, J.; Hillis, D. L.; Granstedt, E. M.; Majeski, R.; Kaita, R.

2015-11-01

Preliminary design of a Digital Holography (DH) in-situ Plasma Facing Component (PFC) erosion diagnostic to be used on the proto-MPEX/MPEX experiment is presented. Design trade-offs are discussed including the selection of CO2 laser frequencies and whether/where to use reflective or refractive optical components. The costs and benefits of using a high-speed (expensive) infrared (IR) camera or a lower speed (inexpensive) IR camera, and whether to use simultaneous or sequential acquisition of DH exposures for the dual wavelength system are also described. Expected layout, resolution, and noise figures will be discussed, along with resolution and noise data from previous work at ORNL and PPPL. Partial Support from USDOE Contract DE-AC02-09CH11466 and USDOE Grant DE-FG02-07ER84724 for previous Digital Holography work done at ORNL and PPPL is gratefully acknowledged.

HELIOSEISMIC HOLOGRAPHY OF SIMULATED SUNSPOTS: MAGNETIC AND THERMAL CONTRIBUTIONS TO TRAVEL TIMES.

PubMed

Felipe, T; Braun, D C; Crouch, A D; Birch, A C

2016-10-01

Wave propagation through sunspots involves conversion between waves of acoustic and magnetic character. In addition, the thermal structure of sunspots is very different than that of the quiet Sun. As a consequence, the interpretation of local helioseismic measurements of sunspots has long been a challenge. With the aim of understanding these measurements, we carry out numerical simulations of wave propagation through sunspots. Helioseismic holography measurements made from the resulting simulated wavefields show qualitative agreement with observations of real sunspots. We use additional numerical experiments to determine, separately, the influence of the thermal structure of the sunspot and the direct effect of the sunspot magnetic field. We use the ray approximation to show that the travel-time shifts in the thermal (non-magnetic) sunspot model are primarily produced by changes in the wave path due to the Wilson depression rather than variations in the wave speed. This shows that inversions for the subsurface structure of sunspots must account for local changes in the density. In some ranges of horizontal phase speed and frequency there is agreement (within the noise level in the simulations) between the travel times measured in the full magnetic sunspot model and the thermal model. If this conclusion proves to be robust for a wide range of models, it would suggest a path toward inversions for sunspot structure.

HELIOSEISMIC HOLOGRAPHY OF SIMULATED SUNSPOTS: MAGNETIC AND THERMAL CONTRIBUTIONS TO TRAVEL TIMES

PubMed Central

Felipe, T.; Braun, D. C.; Crouch, A. D.; Birch, A. C.

2018-01-01

Wave propagation through sunspots involves conversion between waves of acoustic and magnetic character. In addition, the thermal structure of sunspots is very different than that of the quiet Sun. As a consequence, the interpretation of local helioseismic measurements of sunspots has long been a challenge. With the aim of understanding these measurements, we carry out numerical simulations of wave propagation through sunspots. Helioseismic holography measurements made from the resulting simulated wavefields show qualitative agreement with observations of real sunspots. We use additional numerical experiments to determine, separately, the influence of the thermal structure of the sunspot and the direct effect of the sunspot magnetic field. We use the ray approximation to show that the travel-time shifts in the thermal (non-magnetic) sunspot model are primarily produced by changes in the wave path due to the Wilson depression rather than variations in the wave speed. This shows that inversions for the subsurface structure of sunspots must account for local changes in the density. In some ranges of horizontal phase speed and frequency there is agreement (within the noise level in the simulations) between the travel times measured in the full magnetic sunspot model and the thermal model. If this conclusion proves to be robust for a wide range of models, it would suggest a path toward inversions for sunspot structure. PMID:29670301

HELIOSEISMIC HOLOGRAPHY OF SIMULATED SUNSPOTS: MAGNETIC AND THERMAL CONTRIBUTIONS TO TRAVEL TIMES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Felipe, T.; Braun, D. C.; Crouch, A. D.

Wave propagation through sunspots involves conversion between waves of acoustic and magnetic character. In addition, the thermal structure of sunspots is very different than that of the quiet Sun. As a consequence, the interpretation of local helioseismic measurements of sunspots has long been a challenge. With the aim of understanding these measurements, we carry out numerical simulations of wave propagation through sunspots. Helioseismic holography measurements made from the resulting simulated wavefields show qualitative agreement with observations of real sunspots. We use additional numerical experiments to determine, separately, the influence of the thermal structure of the sunspot and the direct effectmore » of the sunspot magnetic field. We use the ray approximation to show that the travel-time shifts in the thermal (non-magnetic) sunspot model are primarily produced by changes in the wave path due to the Wilson depression rather than variations in the wave speed. This shows that inversions for the subsurface structure of sunspots must account for local changes in the density. In some ranges of horizontal phase speed and frequency there is agreement (within the noise level in the simulations) between the travel times measured in the full magnetic sunspot model and the thermal model. If this conclusion proves to be robust for a wide range of models, it would suggest a path toward inversions for sunspot structure.« less

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

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.

Photolabeling of Tonoplast from Sugar Beet Cell Suspensions by [3H]5-(N-Methyl-N-Isobutyl)-Amiloride, an Inhibitor of the Vacuolar Na+/H+ Antiport 1

PubMed Central

Barkla, Bronwyn J.; Charuk, Jeffrey H. M.; Cragoe, Edward J.; Blumwald, Eduardo

1990-01-01

The effects of 5-(N-methyl-N-isobutyl)-amiloride (MIA), an amiloride analog, was tested on the Na+/H+ antiport activity of intact vacuoles and tonoplast vesicles isolated from sugar beet (Beta vulgaris L.) cell suspension cultures. MIA inhibited Na+/H+ exchange in a competitive manner with a Ki of 2.5 and 5.9 micromolar for ΔpH-dependent 22Na+ influx in tonoplast vesicles and Na+-dependent H+ efflux in intact vacuoles, respectively. Scatchard analysis of the binding of [3H]MIA to tonoplast membranes revealed a high affinity binding component with a Kd of 1.3 micromolar. The close relationship between the dissociation constant value obtained and the constants of inhibition for MIA obtained by fluorescence quenching and isotope exchange suggests that the high affinity component represents a class of sites associated with the tonoplast Na+/H+ antiport. Photolabeling of the tonoplast with [3H]MIA revealed two sets of polypeptides with a different affinity to amiloride and its analog. Images Figure 7 PMID:16667602

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)

Symmetric and asymmetric hybrid cryptosystem based on compressive sensing and computer generated holography

NASA Astrophysics Data System (ADS)

Ma, Lihong; Jin, Weimin

2018-01-01

A novel symmetric and asymmetric hybrid optical cryptosystem is proposed based on compressive sensing combined with computer generated holography. In this method there are six encryption keys, among which two decryption phase masks are different from the two random phase masks used in the encryption process. Therefore, the encryption system has the feature of both symmetric and asymmetric cryptography. On the other hand, because computer generated holography can flexibly digitalize the encrypted information and compressive sensing can significantly reduce data volume, what is more, the final encryption image is real function by phase truncation, the method favors the storage and transmission of the encryption data. The experimental results demonstrate that the proposed encryption scheme boosts the security and has high robustness against noise and occlusion attacks.

A Preliminary Comparison of Three Dimensional Particle Tracking and Sizing using Plenoptic Imaging and Digital In-line Holography [PowerPoint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guildenbecher, Daniel Robert; Munz, Elise Dahnke; Farias, Paul Abraham

2015-12-01

Digital in-line holography and plenoptic photography are two techniques for single-shot, volumetric measurement of 3D particle fields. Here we present a preliminary comparison of the two methods by applying plenoptic imaging to experimental configurations that have been previously investigated with digital in-line holography. These experiments include the tracking of secondary droplets from the impact of a water drop on a thin film of water and tracking of pellets from a shotgun. Both plenoptic imaging and digital in-line holography successfully quantify the 3D nature of these particle fields. This includes measurement of the 3D particle position, individual particle sizes, and three-componentmore » velocity vectors. For the initial processing methods presented here, both techniques give out-of-plane positional accuracy of approximately 1-2 particle diameters. For a fixed image sensor, digital holography achieves higher effective in-plane spatial resolutions. However, collimated and coherent illumination makes holography susceptible to image distortion through index of refraction gradients, as demonstrated in the shotgun experiments. On the other hand, plenotpic imaging allows for a simpler experimental configuration. Furthermore, due to the use of diffuse, white-light illumination, plenoptic imaging is less susceptible to image distortion in the shotgun experiments. Additional work is needed to better quantify sources of uncertainty, particularly in the plenoptic experiments, as well as develop data processing methodologies optimized for the plenoptic measurement.« less

Continuous-wave terahertz digital holography by use of a pyroelectric array camera.

PubMed

Ding, Sheng-Hui; Li, Qi; Li, Yun-Da; Wang, Qi

2011-06-01

Terahertz (THz) digital holography is realized based on a 2.52 THz far-IR gas laser and a commercial 124 × 124 pyroelectric array camera. Off-axis THz holograms are obtained by recording interference patterns between light passing through the sample and the reference wave. A numerical reconstruction process is performed to obtain the field distribution at the object surface. Different targets were imaged to test the system's imaging capability. Compared with THz focal plane images, the image quality of the reconstructed images are improved a lot. The results show that the system's imaging resolution can reach at least 0.4 mm. The system also has the potential for real-time imaging application. This study confirms that digital holography is a promising technique for real-time, high-resolution THz imaging, which has extensive application prospects. © 2011 Optical Society of America

Near-Field Resonance Microwave Tomography and Holography

NASA Astrophysics Data System (ADS)

Gaikovich, K. P.; Smirnov, A. I.; Yanin, D. V.

2018-02-01

We develop the methods of electromagnetic computer near-field microwave tomography of distributed subsurface inhomogeneities of complex dielectric permittivity and of holography (shape retrieval) of internally homogeneous subsurface objects. The methods are based on the solution of the near-field inverse scattering problem from measurements of the resonance-parameter variations of microwave probes above the medium surface. The capabilities of the proposed diagnostic technique are demonstrated in the numerical simulation for sensors with a cylindrical capacitor as a probe element, the edge capacitance of which is sensitive to subsurface inhomogeneities.

Development of a SEM-based low-energy in-line electron holography microscope for individual particle imaging.

PubMed

Adaniya, Hidehito; Cheung, Martin; Cassidy, Cathal; Yamashita, Masao; Shintake, Tsumoru

2018-05-01

A new SEM-based in-line electron holography microscope has been under development. The microscope utilizes conventional SEM and BF-STEM functionality to allow for rapid searching of the specimen of interest, seamless interchange between SEM, BF-STEM and holographic imaging modes, and makes use of coherent low-energy in-line electron holography to obtain low-dose, high-contrast images of light element materials. We report here an overview of the instrumentation and first experimental results on gold nano-particles and carbon nano-fibers for system performance tests. Reconstructed images obtained from the holographic imaging mode of the new microscope show substantial image contrast and resolution compared to those acquired by SEM and BF-STEM modes, demonstrating the feasibility of high-contrast imaging via low-energy in-line electron holography. The prospect of utilizing the new microscope to image purified biological specimens at the individual particle level is discussed and electron optical issues and challenges to further improve resolution and contrast are considered. Copyright © 2018 Elsevier B.V. All rights reserved.

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.

Motion of the Tympanic Membrane after Cartilage Tympanoplasty Determined by Stroboscopic Holography

PubMed Central

Aarnisalo, Antti A.; Cheng, Jeffrey T.; Ravicz, Michael E.; Furlong, Cosme; Merchant, Saumil N.; Rosowski, John J.

2009-01-01

Stroboscopic holography was used to quantify dynamic deformations of the tympanic membrane (TM) of the entire surface of the TM before and after cartilage tympanoplasty of the posterior or posterior-superior part of the TM. Cartilage is widely used in tympanoplasties to provide mechanical stability for the TM. Three human cadaveric temporal bones were used. A 6 mm × 3 mm oval cartilage graft was placed through the widely opened facial recess onto the medial surface of the posterior or posterior-superior part of the TM. The graft was either in contact with the bony tympanic rim and manubrium or not. Graft thickness was either 0.5 or 1.0 mm. Stroboscopic holography produced displacement amplitude and phase maps of the TM surface in response to stimulus sound. Sound stimuli were 0.5, 1, 4 and 7 (or 8) kHz tones. Middle ear impedance was measured from the motion of the entire TM. Cartilage placement generally produced reductions in the motion of the TM apposed to the cartilage, especially at 4 kHz and 7 or 8 kHz. Some parts of the TM showed altered motion compared to the control in all three cases. In general, middle ear impedance was either unchanged or increased somewhat after cartilage reconstruction both at low (0.5 and 1 kHz) and high (4 and 7 kHz) frequencies. At 4 kHz, with the 1.0 mm thick graft that was in contact with the bony tympanic rim, the impedance slightly decreased. While our earlier work with time-averaged holography allowed us to observe differences in the pattern of TM motion caused by application of cartilage to the TM, stroboscopic holography is more sensitive to TM motions and allowed us to quantify the magnitude and phase of motion of each point on the TM surface. Nonetheless, our results are similar to those of our earlier work: The placement of cartilage on the medial surface of TM reduces the motion of the TM that apposes the cartilage. These obvious local changes occur even though the cartilage had little effect on the sound-induced motion

Practical holography III; Proceedings of the Meeting, Los Angeles, CA, Jan. 17, 18, 1989

NASA Astrophysics Data System (ADS)

Benton, Stephen A.

Various papers on practical holography are presented. Individual topics addressed include: design of large format commercial display holograms, design of a one-step full-color holographic recording system, color reflection holography, full color rainbow hologram using a photoresist plate, secondary effects in processing holograms, archival properties of holograms, survey of properties of volume holographic materials, image stability of DMP-128 holograms, activation monitor for DMP-128, microwave drying effects on dichromated gelatin holograms, sensitization process of dichromated gelatin, holographic optics for vision systems, holographic fingerprint sensor, cross-talk and cross-coupling in multiplexed holographic gratings, compact illuminators for transmission holograms, solar holoconcentrators in dichromated grains, three-dimensional display of scientific data, holographic liquid crystal displays, in situ swelling for hologaphic color control.

Stochastic digital holography for visualizing inside strongly refracting transparent objects.

PubMed

Desse, Jean-Michel; Picart, Pascal

2015-01-01

This paper presents a digital holographic method to visualize and measure refractive index variations, convection currents, or thermal gradients, occurring inside a transparent and refracting object. The proof of principle is provided through the visualization of refractive index variation inside a lighting bulb. Comparison with transmission and reflection holography is also provided. A very good agreement is obtained, thus validating the proposed approach.

In situ biasing and off-axis electron holography of a ZnO nanowire

NASA Astrophysics Data System (ADS)

den Hertog, Martien; Donatini, Fabrice; McLeod, Robert; Monroy, Eva; Sartel, Corinne; Sallet, Vincent; Pernot, Julien

2018-01-01

Quantitative characterization of electrically active dopants and surface charges in nano-objects is challenging, since most characterization techniques using electrons [1-3], ions [4] or field ionization effects [5-7] study the chemical presence of dopants, which are not necessarily electrically active. We perform cathodoluminescence and voltage contrast experiments on a contacted and biased ZnO nanowire with a Schottky contact and measure the depletion length as a function of reverse bias. We compare these results with state-of-the-art off-axis electron holography in combination with electrical in situ biasing on the same nanowire. The extension of the depletion length under bias observed in scanning electron microscopy based techniques is unusual as it follows a linear rather than square root dependence, and is therefore difficult to model by bulk equations or finite element simulations. In contrast, the analysis of the axial depletion length observed by holography may be compared with three-dimensional simulations, which allows estimating an n-doping level of 1 × 1018 cm-3 and negative sidewall surface charge of 2.5 × 1012 cm-2 of the nanowire, resulting in a radial surface depletion to a depth of 36 nm. We found excellent agreement between the simulated diameter of the undepleted core and the active thickness observed in the experimental data. By combining TEM holography experiments and finite element simulation of the NW electrostatics, the bulk-like character of the nanowire core is revealed.

Real-time visualization and analysis of airflow field by use of digital holography

NASA Astrophysics Data System (ADS)

Di, Jianglei; Wu, Bingjing; Chen, Xin; Liu, Junjiang; Wang, Jun; Zhao, Jianlin

2013-04-01

The measurement and analysis of airflow field is very important in fluid dynamics. For airflow, smoke particles can be added to visually observe the turbulence phenomena by particle tracking technology, but the effect of smoke particles to follow the high speed airflow will reduce the measurement accuracy. In recent years, with the advantage of non-contact, nondestructive, fast and full-field measurement, digital holography has been widely applied in many fields, such as deformation and vibration analysis, particle characterization, refractive index measurement, and so on. In this paper, we present a method to measure the airflow field by use of digital holography. A small wind tunnel model made of acrylic glass is built to control the velocity and direction of airflow. Different shapes of samples such as aircraft wing and cylinder are placed in the wind tunnel model to produce different forms of flow field. With a Mach-Zehnder interferometer setup, a series of digital holograms carrying the information of airflow filed distributions in different states are recorded by CCD camera and corresponding holographic images are numerically reconstructed from the holograms by computer. Then we can conveniently obtain the velocity or pressure information of the airflow deduced from the quantitative phase information of holographic images and visually display the airflow filed and its evolution in the form of a movie. The theory and experiment results show that digital holography is a robust and feasible approach for real-time visualization and analysis of airflow field.

NaHS restores mitochondrial function and inhibits autophagy by activating the PI3K/Akt/mTOR signalling pathway to improve functional recovery after traumatic brain injury.

PubMed

Xu, Kebin; Wu, Fangfang; Xu, Ke; Li, Zhengmao; Wei, Xiaojie; Lu, Qi; Jiang, Ting; Wu, Fenzan; Xu, Xinlong; Xiao, Jian; Chen, Daqing; Zhang, Hongyu

2018-04-25

Traumatic brain injury (TBI) is one of the most serious public health problems in the world. TBI causes neurological deficits by triggering secondary injuries. Hydrogen sulfide (H 2 S), a gaseous mediator, has been reported to exert neuroprotective effects in central nervous system diseases, such as TBI. However, the molecular mechanisms involved in this effect are still unclear. The present study was designed to explore the ability of NaHS, a H 2 S donor, to provide neuroprotection in a mouse model of TBI and to discover the associated molecular mechanisms of these protective effects. Here, we found that administration of NaHS not only maintained the integrity of the blood brain barrier (BBB), protected neurons from apoptosis, and promoted remyelination and axonal reparation but also protected mitochondrial function. In addition, we found that autophagy was inhibited after treatment with NaHS following TBI, an effect that was induced by activation of the PI3K/AKT/mTOR signalling pathway. Our study indicated that H 2 S treatment is beneficial for TBI, pointing to H 2 S as a potential therapeutic target for treating TBI. Copyright © 2018. Published by Elsevier B.V.

Direct Observation of Individual Charges and Their Dynamics on Graphene by Low-Energy Electron Holography.

PubMed

Latychevskaia, Tatiana; Wicki, Flavio; Longchamp, Jean-Nicolas; Escher, Conrad; Fink, Hans-Werner

2016-09-14

Visualizing individual charges confined to molecules and observing their dynamics with high spatial resolution is a challenge for advancing various fields in science, ranging from mesoscopic physics to electron transfer events in biological molecules. We show here that the high sensitivity of low-energy electrons to local electric fields can be employed to directly visualize individual charged adsorbates and to study their behavior in a quantitative way. This makes electron holography a unique probing tool for directly visualizing charge distributions with a sensitivity of a fraction of an elementary charge. Moreover, spatial resolution in the nanometer range and fast data acquisition inherent to lens-less low-energy electron holography allows for direct visual inspection of charge transfer processes.

Observation of hole accumulation in Ge/Si core/shell nanowires using off-axis electron holography.

PubMed

Li, Luying; Smith, David J; Dailey, Eric; Madras, Prashanth; Drucker, Jeff; McCartney, Martha R

2011-02-09

Hole accumulation in Ge/Si core/shell nanowires (NWs) has been observed and quantified using off-axis electron holography and other electron microscopy techniques. The epitaxial [110]-oriented Ge/Si core/shell NWs were grown on Si (111) substrates by chemical vapor deposition through the vapor-liquid-solid growth mechanism. High-angle annular-dark-field scanning transmission electron microscopy images and off-axis electron holograms were obtained from specific NWs. The excess phase shifts measured by electron holography across the NWs indicated the presence of holes inside the Ge cores. Calculations based on a simplified coaxial cylindrical model gave hole densities of (0.4 ± 0.2) /nm(3) in the core regions.

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.

Wavefront division digital holography

NASA Astrophysics Data System (ADS)

Zhang, Wenhui; Cao, Liangcai; Li, Rujia; Zhang, Hua; Zhang, Hao; Jiang, Qiang; Jin, Guofan

2018-05-01

Digital holography (DH), mostly Mach-Zehnder configuration based, belongs to non-common path amplitude splitting interference imaging whose stability and fringe contrast are environmental sensitive. This paper presents a wavefront division DH configuration with both high stability and high-contrast fringes benefitting from quasi common path wavefront-splitting interference. In our proposal, two spherical waves with similar curvature coming from the same wavefront are used, which makes full use of the physical sampling capacity of the detectors. The interference fringe spacing can be adjusted flexibly for both in-line and off-axis mode due to the independent modulation to these two waves. Only a few optical elements, including the mirror-beam splitter interference component, are used without strict alignments, which makes it robust and easy-to-implement. The proposed wavefront division DH promotes interference imaging physics into the practical and miniaturized a step forward. The feasibility of this method is proved by the imaging of a resolution target and a water flea.

Comparison of three-dimensional particle tracking and sizing using plenoptic imaging and digital in-line holography.

PubMed

Hall, Elise M; Thurow, Brian S; Guildenbecher, Daniel R

2016-08-10

Digital in-line holography (DIH) and plenoptic photography are two techniques for single-shot, volumetric measurement of 3D particle fields. Here we present a comparison of the two methods by applying plenoptic imaging to experimental configurations that have been previously investigated with DIH. These experiments include the tracking of secondary droplets from the impact of a water drop on a thin film of water and tracking of pellets from a shotgun. Both plenoptic imaging and DIH successfully quantify the 3D nature of these particle fields. This includes measurement of the 3D particle position, individual particle sizes, and three-component velocity vectors. For the initial processing methods presented here, both techniques give out-of-plane positional accuracy of approximately 1-2 particle diameters. For a fixed image sensor, digital holography achieves higher effective in-plane spatial resolutions. However, collimated and coherent illumination makes holography susceptible to image distortion through index of refraction gradients, as demonstrated in the shotgun experiments. In contrast, plenoptic imaging allows for a simpler experimental configuration and, due to the use of diffuse, white-light illumination, plenoptic imaging is less susceptible to image distortion in the shotgun experiments.

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.

Nanoscale magnetic characterization of tunneling magnetoresistance spin valve head by electron holography.

PubMed

Park, Hyun Soon; Hirata, Kei; Yanagisawa, Keiichi; Ishida, Yoichi; Matsuda, Tsuyoshi; Shindo, Daisuke; Tonomura, Akira

2012-12-07

Nanostructured magnetic materials play an important role in increasing miniaturized devices. For the studies of their magnetic properties and behaviors, nanoscale imaging of magnetic field is indispensible. Here, using electron holography, the magnetization distribution of a TMR spin valve head of commercial design is investigated without and with a magnetic field applied. Characterized is the magnetic flux distribution in complex hetero-nanostructures by averaging the phase images and separating their component magnetic vectors and electric potentials. The magnetic flux densities of the NiFe (shield and 5 nm-free layers) and the CoPt (20 nm-bias layer) are estimated to be 1.0 T and 0.9 T, respectively. The changes in the magnetization distribution of the shield, bias, and free layers are visualized in situ for an applied field of 14 kOe. This study demonstrates the promise of electron holography for characterizing the magnetic properties of hetero-interfaces, nanostructures, and catalysts. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Off-axis electron holography of bacterial cells and magnetic nanoparticles in liquid

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prozorov, Tanya; Almeida, Trevor P.; Kovacs, Andras

Here, the mapping of electrostatic potentials and magnetic fields in liquids using electron holography has been considered to be unrealistic. Here, we show that hydrated cells of Magnetospirillum magneticum strain AMB-1 and assemblies of magnetic nanoparticles can be studied using off-axis electron holography in a fluid cell specimen holder within the transmission electron microscope. Considering that the holographic object and reference wave both pass through liquid, the recorded electron holograms show sufficient interference fringe contrast to permit reconstruction of the phase shift of the electron wave and mapping of the magnetic induction from bacterial magnetite nanocrystals. We assess the challengesmore » of performing in situ magnetization reversal experiments using a fluid cell specimen holder, discuss approaches for improving spatial resolution and specimen stability, and outline future perspectives for studying scientific phenomena, ranging from interparticle interactions in liquids and electrical double layers at solid–liquid interfaces to biomineralization and the mapping of electrostatic potentials associated with protein aggregation and folding.« less

Off-axis electron holography of bacterial cells and magnetic nanoparticles in liquid

DOE PAGES

Prozorov, Tanya; Almeida, Trevor P.; Kovacs, Andras; ...

2017-10-02

Here, the mapping of electrostatic potentials and magnetic fields in liquids using electron holography has been considered to be unrealistic. Here, we show that hydrated cells of Magnetospirillum magneticum strain AMB-1 and assemblies of magnetic nanoparticles can be studied using off-axis electron holography in a fluid cell specimen holder within the transmission electron microscope. Considering that the holographic object and reference wave both pass through liquid, the recorded electron holograms show sufficient interference fringe contrast to permit reconstruction of the phase shift of the electron wave and mapping of the magnetic induction from bacterial magnetite nanocrystals. We assess the challengesmore » of performing in situ magnetization reversal experiments using a fluid cell specimen holder, discuss approaches for improving spatial resolution and specimen stability, and outline future perspectives for studying scientific phenomena, ranging from interparticle interactions in liquids and electrical double layers at solid–liquid interfaces to biomineralization and the mapping of electrostatic potentials associated with protein aggregation and folding.« less

Micro-vibration detection with heterodyne holography based on time-averaged method

NASA Astrophysics Data System (ADS)

Qin, XiaoDong; Pan, Feng; Chen, ZongHui; Hou, XueQin; Xiao, Wen

2017-02-01

We propose a micro-vibration detection method by introducing heterodyne interferometry to time-averaged holography. This method compensates for the deficiency of time-average holography in quantitative measurements and widens its range of application effectively. Acousto-optic modulators are used to modulate the frequencies of the reference beam and the object beam. Accurate detection of the maximum amplitude of each point in the vibration plane is performed by altering the frequency difference of both beams. The range of amplitude detection of plane vibration is extended. In the stable vibration mode, the distribution of the maximum amplitude of each point is measured and the fitted curves are plotted. Hence the plane vibration mode of the object is demonstrated intuitively and detected quantitatively. We analyzed the method in theory and built an experimental system with a sine signal as the excitation source and a typical piezoelectric ceramic plate as the target. The experimental results indicate that, within a certain error range, the detected vibration mode agrees with the intrinsic vibration characteristics of the object, thus proving the validity of this method.

The applicability of holography in forensic identification: a fusion of the traditional optical technique and digital technique.

PubMed

Biwasaka, Hitoshi; Saigusa, Kiyoshi; Aoki, Yasuhiro

2005-03-01

In this study, the applicability of holography in the 3-dimensional recording of forensic objects such as skulls and mandibulae, and the accuracy of the reconstructed 3-D images, were examined. The virtual holographic image, which records the 3-dimensional data of the original object, is visually observed on the other side of the holographic plate, and reproduces the 3-dimensional shape of the object well. Another type of holographic image, the real image, is focused on a frosted glass screen, and cross-sectional images of the object can be observed. When measuring the distances between anatomical reference points using an image-processing software, the average deviations in the holographic images as compared to the actual objects were less than 0.1 mm. Therefore, holography could be useful as a 3-dimensional recording method of forensic objects. Two superimposition systems using holographic images were examined. In the 2D-3D system, the transparent virtual holographic image of an object is directly superimposed onto the digitized photograph of the same object on the LCD monitor. On the other hand, in the video system, the holographic image captured by the CCD camera is superimposed onto the digitized photographic image using a personal computer. We found that the discrepancy between the outlines of the superimposed holographic and photographic dental images using the video system was smaller than that using the 2D-3D system. Holography seemed to perform comparably to the computer graphic system; however, a fusion with the digital technique would expand the utility of holography in superimposition.

Salicylic acid deficiency in NahG transgenic lines and sid2 mutants increases seed yield in the annual plant Arabidopsis thaliana

PubMed Central

Abreu, Maria Elizabeth; Munné-Bosch, Sergi

2009-01-01

Salicylic acid-deficient NahG transgenic lines and sid2 mutants were used to evaluate the role of this compound in the development of the short-lived, annual plant Arabidopsis thaliana, with a particular focus on the interplay between salicylic acid and other phytohormones. Low salicylic acid levels led to increased growth, as well as to smaller abscisic acid levels and reduced damage to PSII (as indicated by Fv/Fm ratios) during the reproductive stages in rosette leaves of NahG transgenic lines and sid2 mutants, compared with wild-type plants. Furthermore, salicylic acid deficiency highly influenced seed yield and composition. Seed production increased by 4.4-fold and 3.5-fold in NahG transgenic lines and sid2 mutants, respectively, compared to the wild type. Salicylic acid deficiency also improved seed composition in terms of antioxidant vitamin concentrations, seeds of salicylic acid-deficient plants showing higher levels of α- and γ-tocopherol (vitamin E) and β-carotene (pro-vitamin A) than seeds of wild-type plants. Seeds of salicylic acid-deficient plants also showed higher nitrogen concentrations than seeds of wild-type plants. It is concluded that (i) the sid2 gene, which encodes for isochorismate synthase, plays a central role in salicylic acid biosynthesis during plant development in A. thaliana, (ii) salicylic acid plays a role in the regulation of growth, senescence, and seed production, (iii) there is a cross-talk between salicylic acid and other phytohormones during plant development, and (iv) the concentrations of antioxidant vitamins in seeds may be influenced by the endogenous levels of salicylic acid in plants. PMID:19188277

Teaching holography in an art school environment: the program at the School of the Art Institute of Chicago

NASA Astrophysics Data System (ADS)

Wesly, Edward J.

1991-03-01

The philosophy of the holography department The School of the Art Institute of Chicago (SAIC) is discussed along with a fine arts curriculum designed to take into account the learning styles of art school students. A description of the facilities follow ending with a survey of artwork by the best students. Introduct ion Holography is almost unheard of in the art world when it is mentioned it is apt to be used as a metaphor for the ultimate in tastelessness. Occasionally a ''recognized'' artist will dabble in holography using the facilities of a commercial lab translating his concept into a hologram1. The results usually raise objections from the clique of handson holographic artists who feel that they are213 on the other hand are being discriminated against by the art world because they practice in a technical medium. As a way of improving the situation art school students must be better educated in the fine arts aspect of holography laboratory techniques and how to set up their own studios. For it will be only through the efforts of the " hands-on" workers will the medium fully realize its creative potential. This then is the major goal of this teacher: to help the students realize their full potential creating artful holograms with inexpensive equipment. Not only is it necessary that the holographic artist learn to work within the constraints of equipment at hand

Interstellar holography

NASA Astrophysics Data System (ADS)

Walker, M. A.; Koopmans, L. V. E.; Stinebring, D. R.; van Straten, W.

2008-08-01

The dynamic spectrum of a radio pulsar is an in-line digital hologram of the ionized interstellar medium. It has previously been demonstrated that such holograms permit image reconstruction, in the sense that one can determine an approximation to the complex electric field values as a function of Doppler shift and delay, but to date the quality of the reconstructions has been poor. Here we report a substantial improvement in the method which we have achieved by simultaneous optimization of the thousands of coefficients that describe the electric field. For our test spectrum of PSRB0834+06 we find that the model provides an accurate representation of the data over the full 63dB dynamic range of the observations: residual differences between model and data are noise like. The advent of interstellar holography enables detailed quantitative investigation of the interstellar radio-wave propagation paths for a given pulsar at each epoch of observation. We illustrate this using our test data which show the scattering material to be structured and highly anisotropic. The temporal response of the medium exhibits a scattering tail which extends to beyond 100μs, and the centroid of the pulse at this frequency and this epoch of observation is delayed by approximately 15μs as a result of multipath propagation in the interstellar medium.

Direct Imaging of Charge Density Modulation in Switchable Two-Dimensional Electron Gas at the Oxide Hetero-Interfaces by Using Electron Bean Inline Holography

DTIC Science & Technology

2015-08-16

Switchable Two-Dimensional Electron Gas at the Oxide Hetero-Interfaces by Using Electron Bean Inline Holography 5a. CONTRACT NUMBER FA2386-13-1-4136...Hetero-Interfaces by Using Electron Bean Inline Holography 5a. CONTRACT NUMBER FA2386-13-1-4136 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 61102F

Particle field diagnose using angular multiplexing volume holography

NASA Astrophysics Data System (ADS)

Zhao, Yu; Li, Zeren; Luo, Zhenxiong; Jun, Li; Zhong, Jie; Ye, Yan; Li, Shengfu; Zhu, Jianhua

2017-08-01

The problem of particle field diagnosing using holography can be met in many areas. But single frame hologram can only catch one moment of the fast event, which can't reveal the change process of an unrepeatable fast event. For events in different time-scale, different solution should be used. We did this work to record a laser induced particle field in the time-scale of tens of micron seconds. A laser of pulse sequence mode is applied to provide 10 pulses, the energy and time interval of whom is 150mJ and 1μs. Four pockels cells are employed to pick up the last four pulses for holographic recording, the other pulses are controlled to pre-expose the photopolymer based recording material, which can enhance photosensitivity of the photopolymer during the moment of holographic recording. The angular multiplexing technique and volume holography is accepted to avoid shifting the photopolymer between each shot. Another Q-switch YAG laser (pulse energy 100mJ, pulse width 10ns) is applied to produce the fast event. As a result, we successfully caught the motion process of the laser induced particle field. The time interval of each frame is 1μs, the angular range of the four references is 14°, and the diffraction efficiency of each hologram is less than 2%. After a basic analysis, this optical system could catch more holograms through a compact design.

Correlations Between Micromagnetic, Microstructural and Microchemical Properties in Ultrathin Epitaxial Magnetic Structures. Magnetic Microstructure Observed With Electron Holography in STEM

DTIC Science & Technology

1998-06-10

and Small Particles, Marian Mankos, J.M. Cowley, M.R. Scheinfein, Material Reseach Society Bulletin, October 95’, 45, (1995). 77 Quantitative...Micromagnetics: Electron Holography of Magnetic Thin Films and Multilayers, Marian Mankos, M.R. Scheinfein, J.M. Cowley, IEEE Trans. MAG-32(5), 4150 (1996...Spatial Resolution, Marian . Mankos, Z.J. Yang, M.R. Scheinfein, J.M. Cowley, IEEE-Trans. MAG 30(6), 4497 (1994). 67 Far Out-of-Focus Electron Holography

Middle Ear Mechanics of Cartilage Tympanoplasty Evaluated by Laser Holography and Vibrometry

PubMed Central

Aarnisalo, Antti A.; Cheng, Jeffrey T.; Ravicz, Michael E.; Hulli, Nesim; Harrington, Ellery J.; Hernandez-Montes, Maria S.; Furlong, Cosme; Merchant, Saumil N.; Rosowski, John J.

2010-01-01

Goals To assess the effects of thickness and position of cartilage used to reconstruct the tympanic membrane (TM) using a novel technique, time-averaged laser holography. Background Cartilage is commonly used in TM reconstruction to prevent formation of retraction pockets. The thickness, position, and shape of the cartilage graft may adversely affect TM motion and hearing. We sought to systematically investigate these parameters in an experimental setting. Methods Computer-assisted optoelectronic laser holography was used in 4 human cadaveric temporal bones to study sound-induced TM motion for 500 Hz to 8 kHz. Stapes velocity was measured with a laser Doppler vibrometer. Baseline (control) measurements were made with the TM intact. Measurements were repeated after a 0.5- or 1.0-mm-thick oval piece of conchal cartilage was placed on the medial TM surface in the posterior-superior quadrant. The cartilage was rotated so that it was either in contact with the bony tympanic rim and manubrium or not. Results At frequencies less than 4 kHz, the cartilage graft had only minor effects on the overall TM fringe patterns. The different conditions had no effects on stapes velocity. Greater than 4 kHz, TM motion was reduced over the grafted TM, both with 0.5- and 1.0-mm-thick grafts. No significant differences in stapes velocity were seen with the 2 different thicknesses of cartilage compared with control. Conclusion Computer-assisted optoelectronic laser holography is a promising technique to investigate middle ear mechanics after tympanoplasty. Such positioning may prevent postoperative TM retraction. These findings and conclusions apply to cartilage placed in the posterior-superior TM quadrant. PMID:19779389

Applications Of A Fibre Optic TV Holography System To The Study Of Large Automotive Structures.

NASA Astrophysics Data System (ADS)

Davies, Jeremy C.; Buckberry, Clive H.

1990-04-01

Mono-mode fibre optic components, including directional couplers and piezo-electric phase control elements, have been used to construct a TV holography system. The instrument has advantages of simplicity and ruggedness of construction and, with a 40m fibre optic link to a 600m argon ion laser, has proved to be an ideal tool for studying the structural behaviour of automotive assemblies. The TV holography system is described and two examples presented of its use: analysis of the deformation of a petrol engine cylinder bore due to head bolt forces, and the vibration study of a vehicle bodyshell subjected to wheel induced inputs. Limitations in the application of the technique are identified and future work to address these shortcomings outlined.

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.

Differential Effects of Mutations on the Transport Properties of the Na+/H+ Antiporter NhaA from Escherichia coli*

PubMed Central

Mager, Thomas; Braner, Markus; Kubsch, Bastian; Hatahet, Lina; Alkoby, Dudu; Rimon, Abraham; Padan, Etana; Fendler, Klaus

2013-01-01

Na+/H+ antiporters show a marked pH dependence, which is important for their physiological function in eukaryotic and prokaryotic cells. In NhaA, the Escherichia coli Na+/H+ antiporter, specific single site mutations modulating the pH profile of the transporter have been described in the past. To clarify the mechanism by which these mutations influence the pH dependence of NhaA, the substrate dependence of the kinetics of selected NhaA variants was electrophysiologically investigated and analyzed with a kinetic model. It is shown that the mutations affect NhaA activity in quite different ways by changing the properties of the binding site or the dynamics of the transporter. In the first case, pK and/or KDNa are altered, and in the second case, the rate constants of the conformational transition between the inside and the outside open conformation are modified. It is shown that residues as far apart as 15–20 Å from the binding site can have a significant impact on the dynamics of the conformational transitions or on the binding properties of NhaA. The implications of these results for the pH regulation mechanism of NhaA are discussed. PMID:23836890

Full-color digitized holography for large-scale holographic 3D imaging of physical and nonphysical objects.

PubMed

Matsushima, Kyoji; Sonobe, Noriaki

2018-01-01

Digitized holography techniques are used to reconstruct three-dimensional (3D) images of physical objects using large-scale computer-generated holograms (CGHs). The object field is captured at three wavelengths over a wide area at high densities. Synthetic aperture techniques using single sensors are used for image capture in phase-shifting digital holography. The captured object field is incorporated into a virtual 3D scene that includes nonphysical objects, e.g., polygon-meshed CG models. The synthetic object field is optically reconstructed as a large-scale full-color CGH using red-green-blue color filters. The CGH has a wide full-parallax viewing zone and reconstructs a deep 3D scene with natural motion parallax.

Dependence of reconstructed image characteristics on the observation condition in light-in-flight recording by holography.

PubMed

Komatsu, Aya; Awatsuji, Yasuhiro; Kubota, Toshihiro

2005-08-01

We analyze the dependence of the reconstructed image characteristic on the observation condition in the light-in-flight recording by holography both theoretically and experimentally. This holography makes it possible to record a propagating light pulse. We have found that the shape of the reconstructed image is changed when the observation position is vertically moved along the hologram plane. The reconstructed image is numerically simulated on the basis of the theory and is experimentally obtained by using a 373 fs pulsed laser. The numerical results agree with the experimental result, and the validity of the theory is verified. Also, experimental results are analyzed and the restoration of the reconstructed image is discussed.

Comparison of three-dimensional particle tracking and sizing using plenoptic imaging and digital in-line holography

DOE PAGES

Hall, Elise M.; Thurow, Brian S.; Guildenbecher, Daniel R.

2016-08-08

Digital in-line holography (DIH) and plenoptic photography are two techniques for single-shot, volumetric measurement of 3D particle fields. Here we present a comparison of the two methods by applying plenoptic imaging to experimental configurations that have been previously investigated with DIH. These experiments include the tracking of secondary droplets from the impact of a water drop on a thin film of water and tracking of pellets from a shotgun. Both plenoptic imaging and DIH successfully quantify the 3D nature of these particle fields. Furthermore, this includes measurement of the 3D particle position, individual particle sizes, and three-component velocity vectors. Formore » the initial processing methods presented here, both techniques give out-of-plane positional accuracy of approximately 1–2 particle diameters. For a fixed image sensor, digital holography achieves higher effective in-plane spatial resolutions. However, collimated and coherent illumination makes holography susceptible to image distortion through index of refraction gradients, as demonstrated in the shotgun experiments. In contrast, plenoptic imaging allows for a simpler experimental configuration and, due to the use of diffuse, white-light illumination, plenoptic imaging is less susceptible to image distortion in the shotgun experiments.« less

Optical scanning holography based on compressive sensing using a digital micro-mirror device

NASA Astrophysics Data System (ADS)

A-qian, Sun; Ding-fu, Zhou; Sheng, Yuan; You-jun, Hu; Peng, Zhang; Jian-ming, Yue; xin, Zhou

2017-02-01

Optical scanning holography (OSH) is a distinct digital holography technique, which uses a single two-dimensional (2D) scanning process to record the hologram of a three-dimensional (3D) object. Usually, these 2D scanning processes are in the form of mechanical scanning, and the quality of recorded hologram may be affected due to the limitation of mechanical scanning accuracy and unavoidable vibration of stepper motor's start-stop. In this paper, we propose a new framework, which replaces the 2D mechanical scanning mirrors with a Digital Micro-mirror Device (DMD) to modulate the scanning light field, and we call it OSH based on Compressive Sensing (CS) using a digital micro-mirror device (CS-OSH). CS-OSH can reconstruct the hologram of an object through the use of compressive sensing theory, and then restore the image of object itself. Numerical simulation results confirm this new type OSH can get a reconstructed image with favorable visual quality even under the condition of a low sample rate.

A Novel Marking Reader for Progressive Addition Lenses Based on Gabor Holography.

PubMed

Perucho, Beatriz; Picazo-Bueno, José Angel; Micó, Vicente

2016-05-01

Progressive addition lenses (PALs) are marked with permanent engraved marks (PEMs) at standardized locations. Permanent engraved marks are very useful through the manufacturing and mounting processes, act as locator marks to re-ink the removable marks, and contain useful information about the PAL. However, PEMs are often faint and weak, obscured by scratches, partially occluded, and difficult to recognize on tinted lenses or with antireflection or scratch-resistant coatings. The aim of this article is to present a new generation of portable marking reader based on an extremely simplified concept for visualization and identification of PEMs in PALs. Permanent engraved marks on different PALs are visualized using classical Gabor holography as underlying principle. Gabor holography allows phase sample visualization with adjustable magnification and can be implemented in either classical or digital versions. Here, visual Gabor holography is used to provide a magnified defocused image of the PEMs onto a translucent visualization screen where the PEM is clearly identified. Different types of PALs (conventional, personalized, old and scratched, sunglasses, etc.) have been tested to visualize PEMs with the proposed marking reader. The PEMs are visible in every case, and variable magnification factor can be achieved simply moving up and down the PAL in the instrument. In addition, a second illumination wavelength is also tested, showing the applicability of this novel marking reader for different illuminations. A new concept of marking reader ophthalmic instrument has been presented and validated in the laboratory. The configuration involves only a commercial-grade laser diode and a visualization screen for PEM identification. The instrument is portable, economic, and easy to use, and it can be used for identifying patient's current PAL model and for marking removable PALs again or finding test points regardless of the age of the PAL, its scratches, tints, or coatings.

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.

High performance organic distributed Bragg reflector lasers fabricated by dot matrix holography.

PubMed

Wan, Wenqiang; Huang, Wenbin; Pu, Donglin; Qiao, Wen; Ye, Yan; Wei, Guojun; Fang, Zongbao; Zhou, Xiaohong; Chen, Linsen

2015-12-14

We report distributed Bragg reflector (DBR) polymer lasers fabricated using dot matrix holography. Pairs of distributed Bragg reflector mirrors with variable mirror separations are fabricated and a novel energy transfer blend consisting of a blue-emitting conjugated polymer and a red-emitting one is spin-coated onto the patterned substrate to complete the device. Under optical pumping, the device emits sing-mode lasing around 622 nm with a bandwidth of 0.41 nm. The working threshold is as low as 13.5 μJ/cm² (~1.68 kW/cm²) and the measured slope efficiency reaches 5.2%. The distributed feedback (DFB) cavity and the DBR cavity resonate at the same lasing wavelength while the DFB laser shows a much higher threshold. We further show that flexible DBR lasers can be conveniently fabricated through the UV-imprinting technique by using the patterned silica substrate as the mold. Dot matrix holography represents a versatile approach to control the number, the size, the location and the orientation of DBR mirrors, thus providing great flexibility in designing DBR lasers.

Testing holography using lattice super-Yang-Mills theory on a 2-torus

NASA Astrophysics Data System (ADS)

Catterall, Simon; Jha, Raghav G.; Schaich, David; Wiseman, Toby

2018-04-01

We consider maximally supersymmetric SU (N ) Yang-Mills theory in Euclidean signature compactified on a flat two-dimensional torus with antiperiodic ("thermal") fermion boundary conditions imposed on one cycle. At large N , holography predicts that this theory describes certain black hole solutions in type IIA and IIB supergravity, and we use lattice gauge theory to test this. Unlike the one-dimensional quantum mechanics case where there is only the dimensionless temperature to vary, here we emphasize there are two more parameters which determine the shape of the flat torus. While a rectangular Euclidean torus yields a thermal interpretation, allowing for skewed tori modifies the holographic dual black hole predictions and results in another direction to test holography. Our lattice calculations are based on a supersymmetric formulation naturally adapted to a particular skewing. Using this we perform simulations up to N =16 with several lattice spacings for both skewed and rectangular tori. We observe the two expected black hole phases with their predicted behavior, with a transition between them that is consistent with the gravity prediction based on the Gregory-Laflamme transition.

X-ray Fluorescence Holography: Principles, Apparatus, and Applications

NASA Astrophysics Data System (ADS)

Hayashi, Kouichi; Korecki, Pawel

2018-06-01

X-ray fluorescence holography (XFH) is an atomic structure determination technique that combines the capabilities of X-ray diffraction and X-ray fluorescence spectroscopy. It provides a unique means of gaining fully three-dimensional information about the local atomic structure and lattice site positions of selected elements inside compound samples. In this work, we discuss experimental and theoretical aspects that are essential for the efficient recording and analysis of X-ray fluorescence holograms and review the most recent advances in XFH. We describe experiments performed with brilliant synchrotron radiation as well as with tabletop setups that employ conventional X-ray tubes.

Finite Inflation, Holography, and Dark Matter Annihilation

NASA Astrophysics Data System (ADS)

Scacco, Andrew Joseph

This thesis covers work on theoretical cosmology relating to inflation, de Sitter space, dark matter annihilation, and holography. A unifying feature of all these topics is that all of them occur in de Sitter space or focus on epochs of the Universe when the spacetime was close to de Sitter and that all of them have some connection to holography. Chapter 1 provides a pedagogical introduction to the fundamentals of cosmology, inflation, de Sitter space, dark matter annihilation and entanglement entropy. Chapter 2 covers the impact on the causal entropic principle of dark matter annihilation that we find to have the greatest relevance at late times in the future when the dark energy has driven the universe to be asymptotically de Sitter. In this chapter we estimate holographically preferred dark matter properties for a range of assumptions. Chapter 3 covers holographic bounds in models of finite inflation, specifically the Banks-Fischler bound and de Sitter equilibrium. The assumptions in each of these models are explored in detail and some interesting new connections are presented. Chapter 4 tests models of inflation with a fast-roll start that happen to satisfy the holographic bounds in Chapter 3 against cosmic microwave background data from Planck. We find a slight preference for a feature at the scale predicted by the Banks-Fischler bound though this preference is not found to be statistically significant. Chapter 5 contains a numerical computation of the holographic mutual information for an annular configuration of regions on a conformal field theory in de Sitter space using the AdS/CFT correspondence. This computation shows that the de Sitter space CFT entanglement entropy matches what would be expected from a Minkowski CFT and shows that the HRT conjecture works for this case.

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

The intracellular Na(+)/H(+) exchanger NHE7 effects a Na(+)-coupled, but not K(+)-coupled proton-loading mechanism in endocytosis.

PubMed

Milosavljevic, Nina; Monet, Michaël; Léna, Isabelle; Brau, Frédéric; Lacas-Gervais, Sandra; Feliciangeli, Sylvain; Counillon, Laurent; Poët, Mallorie

2014-05-08

Vesicular H(+)-ATPases and ClC-chloride transporters are described to acidify intracellular compartments, which also express the highly conserved Na(+)/H(+) exchangers NHE6, NHE7, and NHE9. Mutations of these exchangers cause autism-spectrum disorders and neurodegeneration. NHE6, NHE7, and NHE9 are hypothesized to exchange cytosolic K(+) for H(+) and alkalinize vesicles, but this notion has remained untested in K(+) because their intracellular localization prevents functional measurements. Using proton-killing techniques, we selected a cell line that expresses wild-type NHE7 at the plasma membrane, enabling measurement of the exchanger's transport parameters. We found that NHE7 transports Li(+) and Na(+), but not K(+), is nonreversible in physiological conditions and is constitutively activated by cytosolic H(+). Therefore, NHE7 acts as a proton-loading transporter rather than a proton leak. NHE7 mediates an acidification of intracellular vesicles that is additive to that of V-ATPases and that accelerates endocytosis. This study reveals an unexpected function for vesicular Na(+)/H(+) exchangers and provides clues for understanding NHE-linked neurological disorders. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

The Current Status of the Development of Light-Sensitive Media for Holography (a Review)

NASA Astrophysics Data System (ADS)

Barachevsky, V. A.

2018-03-01

The results of studies that have been performed over the last decade in the field of development of silver halide and nonsilver holographic recording media of organic and inorganic origin are analyzed. It is shown that previously developed materials mainly allow the development of holographic investigations. Among irreversible materials, considerable progress has been made in improving the characteristics of photopolymerizable recording media, which has allowed their use in color image holography and 3D optical archive-type memory, as well as for fabricating holographic optical elements. In the field of improving the properties of reversible holographic recording media, practically significant results have been obtained for the creation of photoanisotropic materials based on azo dyes experiencing cis-trans photoisomerization, which allow the recording of polarization holograms. The needs of dynamic holography have been satisfied by lightsensitive doped inorganic crystals and polymer layers that have been created with nonlinear optical properties.

Pairing induced superconductivity in holography

NASA Astrophysics Data System (ADS)

Bagrov, Andrey; Meszena, Balazs; Schalm, Koenraad

2014-09-01

We study pairing induced superconductivity in large N strongly coupled systems at finite density using holography. In the weakly coupled dual gravitational theory the mechanism is conventional BCS theory. An IR hard wall cut-off is included to ensure that we can controllably address the dynamics of a single confined Fermi surface. We address in detail the interplay between the scalar order parameter field and fermion pairing. Adding an explicitly dynamical scalar operator with the same quantum numbers as the fermion-pair, the theory experiences a BCS/BEC crossover controlled by the relative scaling dimensions. We find the novel result that this BCS/BEC crossover exposes resonances in the canonical expectation value of the scalar operator. This occurs not only when the scaling dimension is degenerate with the Cooper pair, but also with that of higher derivative paired operators. We speculate that a proper definition of the order parameter which takes mixing with these operators into account stays finite nevertheless.

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.

Dynamic modal characterization of musical instruments using digital holography

NASA Astrophysics Data System (ADS)

Demoli, Nazif; Demoli, Ivan

2005-06-01

This study shows that a dynamic modal characterization of musical instruments with membrane can be carried out using a low-cost device and that the obtained very informative results can be presented as a movie. The proposed device is based on a digital holography technique using the quasi-Fourier configuration and time-average principle. Its practical realization with a commercial digital camera and large plane mirrors allows relatively simple analyzing of big vibration surfaces. The experimental measurements given for a percussion instrument are supported by the mathematical formulation of the problem.

Optical sectioning using a digital Fresnel incoherent-holography-based confocal imaging system

PubMed Central

Kelner, Roy; Katz, Barak; Rosen, Joseph

2015-01-01

We propose a new type of confocal microscope using Fresnel incoherent correlation holography (FINCH). Presented here is a confocal configuration of FINCH using a phase pinhole and point illumination that is able to suppress out-of-focus information from the recorded hologram and hence combine the super-resolution capabilities of FINCH with the sectioning capabilities of confocal microscopy. PMID:26413560

Endoscopic pulsed digital holography for 3D measurements

NASA Astrophysics Data System (ADS)

Saucedo, A. Tonatiuh; Mendoza Santoyo, Fernando; de La Torre-Ibarra, Manuel; Pedrini, Giancarlo; Osten, Wolfgang

2006-02-01

A rigid endoscope and three different object illumination source positions are used in pulsed digital holography to measure the three orthogonal displacement components from hidden areas of a harmonically vibrating metallic cylinder. In order to obtain simultaneous 3D information from the optical set up, it is necessary to match the optical paths of each of the reference object beam pairs, but to incoherently mismatch the three reference object beam pairs, such that three pulsed digital holograms are incoherently recorded within a single frame of the CCD sensor. The phase difference is obtained using the Fourier method and by subtracting two digital holograms captured for two different object positions.

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. © 2012 Optical Society of America

Projecting non-diffracting waves with intermediate-plane holography.

PubMed

Mondal, Argha; Yevick, Aaron; Blackburn, Lauren C; Kanellakopoulos, Nikitas; Grier, David G

2018-02-19

We introduce intermediate-plane holography, which substantially improves the ability of holographic trapping systems to project propagation-invariant modes of light using phase-only diffractive optical elements. Translating the mode-forming hologram to an intermediate plane in the optical train can reduce the need to encode amplitude variations in the field, and therefore complements well-established techniques for encoding complex-valued transfer functions into phase-only holograms. Compared to standard holographic trapping implementations, intermediate-plane holograms greatly improve diffraction efficiency and mode purity of propagation-invariant modes, and so increase their useful non-diffracting range. We demonstrate this technique through experimental realizations of accelerating modes and long-range tractor beams.

Large holographic 3D display for real-time computer-generated holography

NASA Astrophysics Data System (ADS)

Häussler, R.; Leister, N.; Stolle, H.

2017-06-01

SeeReal's concept of real-time holography is based on Sub-Hologram encoding and tracked Viewing Windows. This solution leads to significant reduction of pixel count and computation effort compared to conventional holography concepts. Since the first presentation of the concept, improved full-color holographic displays were built with dedicated components. The hologram is encoded on a spatial light modulator that is a sandwich of a phase-modulating and an amplitude-modulating liquid-crystal display and that modulates amplitude and phase of light. Further components are based on holographic optical elements for light collimation and focusing which are exposed in photopolymer films. Camera photographs show that only the depth region on which the focus of the camera lens is set is in focus while the other depth regions are out of focus. These photographs demonstrate that the 3D scene is reconstructed in depth and that accommodation of the eye lenses is supported. Hence, the display is a solution to overcome the accommodationconvergence conflict that is inherent for stereoscopic 3D displays. The main components, progress and results of the holographic display with 300 mm x 200 mm active area are described. Furthermore, photographs of holographic reconstructed 3D scenes are shown.

The Na+/H+ exchanger NHE6 modulates endosomal pH to control processing of amyloid precursor protein in a cell culture model of Alzheimer disease.

PubMed

Prasad, Hari; Rao, Rajini

2015-02-27

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. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

UV laser interaction with a fluorescent dye solution studied using pulsed digital holography.

PubMed

Amer, Eynas; Gren, Per; Sjödahl, Mikael

2013-10-21

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. Simultaneously, a frequency doubled pulse (532 nm) from the same laser is used to probe the solvent perpendicularly resulting in a gain through stimulated laser induced fluorescence (LIF) emission. The resulting gain of the probe beam is recorded using digital holography by blending it with a reference beam on the detector. Two digital holograms without and with the pump beam were recorded. Intensity maps were calculated from the recorded digital holograms and used to calculate the gain of the probe beam due to the stimulated LIF. In addition numerical data of the local temperature rise was calculated from the corresponding phase maps using Radon inversion. It was concluded that about 15% of the pump beam energy is transferred to the dye solution as heat while the rest is consumed in the radiative process. The results show that pulsed digital holography is a promising technique for quantitative study of fluorescent species.

In-situ magnetization/heating electron holography to study the magnetic ordering in arrays of nickel metallic nanowires

NASA Astrophysics Data System (ADS)

Ortega, Eduardo; Santiago, Ulises; Giuliani, Jason G.; Monton, Carlos; Ponce, Arturo

2018-05-01

Magnetic nanostructures of different size, shape, and composition possess a great potential to improve current technologies like data storage and electromagnetic sensing. In thin ferromagnetic nanowires, their magnetization behavior is dominated by the competition between magnetocrystalline anisotropy (related to the crystalline structure) and shape anisotropy. In this way electron diffraction methods like precession electron diffraction (PED) can be used to link the magnetic behavior observed by Electron Holography (EH) with its crystallinity. Using off-axis electron holography under Lorentz conditions, we can experimentally determine the magnetization distribution over neighboring nanostructures and their diamagnetic matrix. In the case of a single row of nickel nanowires within the alumina template, the thin TEM samples showed a dominant antiferromagnetic arrangement demonstrating long-range magnetostatic interactions playing a major role.

In-situ magnetization/heating electron holography to study the magnetic ordering in arrays of nickel metallic nanowires.

PubMed

Ortega, Eduardo; Santiago, Ulises; Giuliani, Jason G; Monton, Carlos; Ponce, Arturo

2018-05-01

Magnetic nanostructures of different size, shape, and composition possess a great potential to improve current technologies like data storage and electromagnetic sensing. In thin ferromagnetic nanowires, their magnetization behavior is dominated by the competition between magnetocrystalline anisotropy (related to the crystalline structure) and shape anisotropy. In this way electron diffraction methods like precession electron diffraction (PED) can be used to link the magnetic behavior observed by Electron Holography (EH) with its crystallinity. Using off-axis electron holography under Lorentz conditions, we can experimentally determine the magnetization distribution over neighboring nanostructures and their diamagnetic matrix. In the case of a single row of nickel nanowires within the alumina template, the thin TEM samples showed a dominant antiferromagnetic arrangement demonstrating long-range magnetostatic interactions playing a major role.

Measurement of the traction force of biological cells by digital holography

PubMed Central

Yu, Xiao; Cross, Michael; Liu, Changgeng; Clark, David C.; Haynie, Donald T.; Kim, Myung K.

2011-01-01

The traction force produced by biological cells has been visualized as distortions in flexible substrata. We have utilized quantitative phase microscopy by digital holography (DH-QPM) to study the wrinkling of a silicone rubber film by motile fibroblasts. Surface deformation and the cellular traction force have been measured from phase profiles in a direct and straightforward manner. DH-QPM is shown to provide highly efficient and versatile means for quantitatively analyzing cellular motility. PMID:22254175

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. Copyright © 2015 Elsevier Ltd. All rights reserved.

A Study Guide on Holography (Draft). Test Edition. AAAS Study Guides on Contemporary Problems.

ERIC Educational Resources Information Center

Jeong, Tung H.

This is one of several study guides on contemporary problems produced by the American Association for the Advancement of Science with support of the National Science Foundation. The primary purpose of this guide is to provide a student with sufficient practical and technical information to begin independently practicing holography, with occasional…

Progress toward time-resolved molecular imaging: A theoretical study of optimal parameters in static photoelectron holography

NASA Astrophysics Data System (ADS)

Sun, S. X.-L.; Kaduwela, A. P.; Gray, A. X.; Fadley, C. S.

2014-05-01

The availability of short-pulse free-electron lasers has led to the idea of using photoelectron holography as a method of directly imaging molecular dissociations or reactions in real time, as, e.g., in a recent theoretical study by Krasniqi et al., [F. Krasniqi, B. Najjari, L. Strüder, D. Rolles, A. Voitkiv, and J. Ullrich, Phys. Rev. A 81, 033411 (2010), 10.1103/PhysRevA.81.033411]. In this paper, we extend this earlier work and in particular look at two critical questions concerning the optimum type of data required for such holographic imaging: the choice of photoelectron kinetic energy (e.g., ˜300 eV versus ˜1700 eV as in the prior study), and the use of a single energy or multiple energies. After verifying that our calculations fully duplicate those in this prior paper, we show that using lower energies is preferable to using higher energies for image quality, a conclusion consistent with prior photoelectron holography studies at surfaces, and that multiple lower energies in which the hologram effectively spans a volume in kspace yields the best quality images that should be useful for such "molecular movies." Although the amount of data required for such multi-energy holography is roughly an order of magnitude higher than that for single energy, the reduction of artifacts and the improved quality of the images suggest this as the optimum ultimate future strategy for such dynamic imaging.

Holography and off-center collisions of localized shock waves

DOE PAGES

Chesler, Paul M.; Yaffe, Laurence G.

2015-10-12

Using numerical holography, we study the collision, at non-zero impact parameter, of bounded, localized distributions of energy density chosen to mimic relativistic heavy ion collisions, in strongly coupled N=4 supersymmetric Yang-Mills theory. Both longitudinal and transverse dynamics in the dual field theory are properly described. Using the gravitational description, we solve 5D Einstein equations with no dimensionality reducing symmetry restrictions to find the asymptotically anti-de Sitter spacetime geometry. Here, the implications of our results on the understanding of early stages of heavy ion collisions, including the development of transverse radial flow, are discussed.

Fast modal decomposition for optical fibers using digital holography.

PubMed

Lyu, Meng; Lin, Zhiquan; Li, Guowei; Situ, Guohai

2017-07-26

Eigenmode decomposition of the light field at the output end of optical fibers can provide fundamental insights into the nature of electromagnetic-wave propagation through the fibers. Here we present a fast and complete modal decomposition technique for step-index optical fibers. The proposed technique employs digital holography to measure the light field at the output end of the multimode optical fiber, and utilizes the modal orthonormal property of the basis modes to calculate the modal coefficients of each mode. Optical experiments were carried out to demonstrate the proposed decomposition technique, showing that this approach is fast, accurate and cost-effective.

Holography for Schrödinger backgrounds

NASA Astrophysics Data System (ADS)

Guica, Monica; Skenderis, Kostas; Taylor, Marika; van Rees, Balt C.

2011-02-01

We discuss holography for Schrödinger solutions of both topologically massive gravity in three dimensions and massive vector theories in ( d + 1) dimensions. In both cases the dual field theory can be viewed as a d-dimensional conformal field theory (two dimensional in the case of TMG) deformed by certain operators that respect the Schrödinger symmetry. These operators are irrelevant from the viewpoint of the relativistic conformal group but they are exactly marginal with respect to the non-relativistic conformal group. The spectrum of linear fluctuations around the background solutions corresponds to operators that are labeled by their scaling dimension and the lightcone momentum k v . We set up the holographic dictionary and compute 2-point functions of these operators both holographically and in field theory using conformal perturbation theory and find agreement. The counterterms needed for holographic renormalization are non-local in the v lightcone direction.

Joint Applied Optics and Chinese Optics Letters feature introduction: digital holography and three-dimensional imaging.

PubMed

Poon, Ting-Chung

2011-12-01

This feature issue serves as a pilot issue promoting the joint issue of Applied Optics and Chinese Optics Letters. It focuses upon topics of current relevance to the community working in the area of digital holography and 3-D imaging. © 2011 Optical Society of America

Holography and the Coleman-Mermin-Wagner theorem

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anninos, Dionysios; Hartnoll, Sean A.; Iqbal, Nabil

2010-09-15

In 2+1 dimensions at finite temperature, spontaneous symmetry breaking of global symmetries is precluded by large thermal fluctuations of the order parameter. The holographic correspondence implies that analogous effects must also occur in 3+1 dimensional theories with gauged symmetries in certain curved spacetimes with horizon. By performing a one loop computation in the background of a holographic superconductor, we show that bulk quantum fluctuations wash out the classical order parameter at sufficiently large distance scales. The low temperature phase is seen to exhibit algebraic long-range order. Beyond the specific example we study, holography suggests that IR singular quantum fluctuations ofmore » the fields and geometry will play an interesting role for many 3+1 dimensional asymptotically anti-de Sitter spacetimes with planar horizon.« less

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.

Resolution enhancement in digital holography by self-extrapolation of holograms.

PubMed

Latychevskaia, Tatiana; Fink, Hans-Werner

2013-03-25

It is generally believed that the resolution in digital holography is limited by the size of the captured holographic record. Here, we present a method to circumvent this limit by self-extrapolating experimental holograms beyond the area that is actually captured. This is done by first padding the surroundings of the hologram and then conducting an iterative reconstruction procedure. The wavefront beyond the experimentally detected area is thus retrieved and the hologram reconstruction shows enhanced resolution. To demonstrate the power of this concept, we apply it to simulated as well as experimental holograms.

Incoherent digital holograms acquired by interferenceless coded aperture correlation holography system without refractive lenses.

PubMed

Kumar, Manoj; Vijayakumar, A; Rosen, Joseph

2017-09-14

We present a lensless, interferenceless incoherent digital holography technique based on the principle of coded aperture correlation holography. The acquired digital hologram by this technique contains a three-dimensional image of some observed scene. Light diffracted by a point object (pinhole) is modulated using a random-like coded phase mask (CPM) and the intensity pattern is recorded and composed as a point spread hologram (PSH). A library of PSHs is created using the same CPM by moving the pinhole to all possible axial locations. Intensity diffracted through the same CPM from an object placed within the axial limits of the PSH library is recorded by a digital camera. The recorded intensity this time is composed as the object hologram. The image of the object at any axial plane is reconstructed by cross-correlating the object hologram with the corresponding component of the PSH library. The reconstruction noise attached to the image is suppressed by various methods. The reconstruction results of multiplane and thick objects by this technique are compared with regular lens-based imaging.

Controlling Fringe Sensitivity of Electro-Optic Holography Systems Using Laser Diode Current Modulation

NASA Technical Reports Server (NTRS)

Bybee, Shannon J.

2001-01-01

Electro-Optic Holography (EOH) is a non-intrusive, laser-based, displacement measurement technique capable of static and dynamic displacement measurements. EOH is an optical interference technique in which fringe patterns that represent displacement contour maps are generated. At excessively large displacements the fringe density may be so great that individual fringes are not resolvable using typical EOH techniques. This thesis focuses on the development and implementation of a method for controlling the sensitivity of the EOH system. This method is known as Frequency Translated Electro-Optic Holography (FTEOH). It was determined that by modulating the current source of the laser diode at integer multiples of the object vibration, the fringe pattern is governed by higher order Bessel function of the first kind and the number of fringes that represent a given displacement can be controlled. The reduction of fringes is theoretically unlimited but physically limited by the frequency bandwidth of the signal generator, providing modulation to the laser diode. Although this research technique has been verified theoretically and experimentally in this thesis, due to the current laser diode capabilities it is a tedious and time consuming process to acquire data using the FTEOH technique.

Estimation of vibration frequency of loudspeaker diaphragm by parallel phase-shifting digital holography

NASA Astrophysics Data System (ADS)

Kakue, T.; Endo, Y.; Shimobaba, T.; Ito, T.

2014-11-01

We report frequency estimation of loudspeaker diaphragm vibrating at high speed by parallel phase-shifting digital holography which is a technique of single-shot phase-shifting interferometry. This technique records multiple phaseshifted holograms required for phase-shifting interferometry by using space-division multiplexing. We constructed a parallel phase-shifting digital holography system consisting of a high-speed polarization-imaging camera. This camera has a micro-polarizer array which selects four linear polarization axes for 2 × 2 pixels. We set a loudspeaker as an object, and recorded vibration of diaphragm of the loudspeaker by the constructed system. By the constructed system, we demonstrated observation of vibration displacement of loudspeaker diaphragm. In this paper, we aim to estimate vibration frequency of the loudspeaker diaphragm by applying the experimental results to frequency analysis. Holograms consisting of 128 × 128 pixels were recorded at a frame rate of 262,500 frames per second by the camera. A sinusoidal wave was input to the loudspeaker via a phone connector. We observed displacement of the loudspeaker diaphragm vibrating by the system. We also succeeded in estimating vibration frequency of the loudspeaker diaphragm by applying frequency analysis to the experimental results.

Differential Stimulation of the Na+/H+ Exchanger Determines Chloroquine Uptake in Plasmodium falciparum

PubMed Central

Wünsch, Stefan; Sanchez, Cecilia P.; Gekle, Michael; Große-Wortmann, Lars; Wiesner, Jochen; Lanzer, Michael

1998-01-01

Here we describe the identification and characterization of a physiological marker that is associated with the chloroquine-resistant (CQR) phenotype in the human malarial parasite Plasmodium falciparum. Single cell in vivo pH measurements revealed that CQR parasites consistently have an elevated cytoplasmic pH compared to that of chloroquine-sensitive (CQS) parasites because of a constitutively activated Na+/H+ exchanger (NHE). Together, biochemical and physiological data suggest that chloroquine activates the plasmodial NHE of CQS parasites, resulting in a transitory phase of rapid sodium/hydrogen ion exchange during which chloroquine is taken up by this protein. The constitutively stimulated NHE of CQR parasites are capable of little or no further activation by chloroquine. We propose that the inability of chloroquine to stimulate its own uptake through the constitutively activated NHE of resistant parasites constitutes a minimal and necessary event in the generation of the chloroquine-resistant phenotype. PMID:9442109

3D endoscopic pulsed digital holography

NASA Astrophysics Data System (ADS)

Saucedo Anaya, T.; Mendoza Santoyo, F.; Pedrini, G.; Osten, W.

2006-06-01

A rigid endoscope is used in pulsed digital holography to simultaneously evaluate the three orthogonal displacement components from hidden areas of a harmonically vibrating metallic cylinder. The cylinder is illuminated from three different illuminating directions. The optical path for each illumination direction is matched to its corresponding reference beam, but also in such a way that each object-reference beam pair optical path is mismatched such that they are incoherent and can be stored in a single CCD frame. As is typical in these types of interferometric arrangements, two digital holograms are needed in order to compare two different states of the cylinder. Each hologram is Fourier transformed and due to the incoherence introduced three separate spectra are readily identified, each belonging to a object-reference beam pair. On comparing by subtraction the phase obtained from the two pulsed digital holograms it is possible to gather quantitative 3D results from harmonic displacements.

Tonoplast Na+/H+ Antiport Activity and Its Energization by the Vacuolar H+-ATPase in the Halophytic Plant Mesembryanthemum crystallinum L.

PubMed Central

Barkla, B. J.; Zingarelli, L.; Blumwald, E.; Smith, JAC.

1995-01-01

Tonoplast vesicles were isolated from leaf mesophyll tissue of the inducible Crassulacean acid metabolism plant Mesembryanthemum crystallinum to investigate the mechanism of vacuolar Na+ accumulation in this halophilic species. In 8-week-old plants exposed to 200 mM NaCl for 2 weeks, tonoplast H+-ATPase activity was approximately doubled compared with control plants of the same age, as determined by rates of both ATP hydrolysis and ATP-dependent H+ transport. Evidence was also obtained for the presence of an electroneutral Na+/H+ antiporter at the tonoplast that is constitutively expressed, since extravesicular Na+ was able to dissipate a pre-existing transmembrane pH gradient. Initial rates of H+ efflux showed saturation kinetics with respect to extravesicular Na+ concentration and were 2.1-fold higher from vesicles of salt-treated plants compared with the controls. Na+-dependent H+ efflux also showed a high selectivity for Na+ over K+, was insensitive to the transmembrane electrical potential difference, and was more than 50% inhibited by 200 [mu]M N-amidino-3,5-diamino-6-chloropyrazinecarboxamide hydrochloride. The close correlation between increased Na+/H+ antiport and H+-ATPase activities in response to salt treatment suggests that accumulation of the very high concentrations of vacuolar Na+ found in M. crystallinum is energized by the H+ electrochemical gradient across the tonoplast. PMID:12228611

Tonoplast Na+/H+ Antiport Activity and Its Energization by the Vacuolar H+-ATPase in the Halophytic Plant Mesembryanthemum crystallinum L.

PubMed

Barkla, B. J.; Zingarelli, L.; Blumwald, E.; Smith, JAC.

1995-10-01

Tonoplast vesicles were isolated from leaf mesophyll tissue of the inducible Crassulacean acid metabolism plant Mesembryanthemum crystallinum to investigate the mechanism of vacuolar Na+ accumulation in this halophilic species. In 8-week-old plants exposed to 200 mM NaCl for 2 weeks, tonoplast H+-ATPase activity was approximately doubled compared with control plants of the same age, as determined by rates of both ATP hydrolysis and ATP-dependent H+ transport. Evidence was also obtained for the presence of an electroneutral Na+/H+ antiporter at the tonoplast that is constitutively expressed, since extravesicular Na+ was able to dissipate a pre-existing transmembrane pH gradient. Initial rates of H+ efflux showed saturation kinetics with respect to extravesicular Na+ concentration and were 2.1-fold higher from vesicles of salt-treated plants compared with the controls. Na+-dependent H+ efflux also showed a high selectivity for Na+ over K+, was insensitive to the transmembrane electrical potential difference, and was more than 50% inhibited by 200 [mu]M N-amidino-3,5-diamino-6-chloropyrazinecarboxamide hydrochloride. The close correlation between increased Na+/H+ antiport and H+-ATPase activities in response to salt treatment suggests that accumulation of the very high concentrations of vacuolar Na+ found in M. crystallinum is energized by the H+ electrochemical gradient across the tonoplast.

Compressive self-interference Fresnel digital holography with faithful reconstruction

NASA Astrophysics Data System (ADS)

Wan, Yuhong; Man, Tianlong; Han, Ying; Zhou, Hongqiang; Wang, Dayong

2017-05-01

We developed compressive self-interference digital holographic approach that allows retrieving three-dimensional information of the spatially incoherent objects from single-shot captured hologram. The Fresnel incoherent correlation holography is combined with parallel phase-shifting technique to instantaneously obtain spatial-multiplexed phase-shifting holograms. The recording scheme is regarded as compressive forward sensing model, thus the compressive-sensing-based reconstruction algorithm is implemented to reconstruct the original object from the under sampled demultiplexed sub-holograms. The concept was verified by simulations and experiments with simulating use of the polarizer array. The proposed technique has great potential to be applied in 3D tracking of spatially incoherent samples.

Digital Holography for in Situ Real-Time Measurement of Plasma-Facing-Component Erosion

DOE Office of Scientific and Technical Information (OSTI.GOV)

ThomasJr., C. E.; Granstedt, E. M.; Biewer, Theodore M

2014-01-01

In situ, real time measurement of net plasma-facing-component (PFC) erosion/deposition in a real plasma device is challenging due to the need for good spatial and temporal resolution, sufficient sensitivity, and immunity to fringe-jump errors. Design of a high-sensitivity, potentially high-speed, dual-wavelength CO2 laser digital holography system (nominally immune to fringe jumps) for PFC erosion measurement is discussed.

Defect modes in silver-doped photonic crystals made by holography using dichromated gelatin

NASA Astrophysics Data System (ADS)

Dai, Rui; Chen, Shujing; Ren, Zhi; Wang, Zhaona; Liu, Dahe

2012-10-01

The defect mode in silver-doped photonic crystals is investigated. 1D and 3D photonic crystals were made by holography using dichromated gelatin mixed with silver nitrate. By controlling the concentration of the silver nitrate, the defect mode was observed in the bandgaps of the holographic photonic crystals. The numerical simulations were made, and the results showed the consistency with the experimental observations.

Na/H and k/h antiport in root membrane vesicles isolated from the halophyte atriplex and the glycophyte cotton.

PubMed

Hassidim, M; Braun, Y; Lerner, H R; Reinhold, L

1990-12-01

Proton fluxes have been followed into and out of membrane vesicles isolated from the roots of the halophyte Atriplex nummularia and the glycophyte Gossypium hirsutum, with the aid of the DeltapH probe [(14)C]methylamine. Evidence is presented for the operation of Na(+)/H(+) and K(+)/H(+) antiporters in the membranes of both plants. Cation supply after a pH gradient has been set up across the vesicle membrane (either as a result of providing ATP to the H(+)-ATPase or by imposing an artificial pH gradient) brings about dissipation of the DeltapH, but does not depolarize the membrane potential as observed in similar experiments, but in the absence of Cl(-), using the DeltaPsi probe SCN(-). Cation/H(+) exchange is thus indicated. This exchange is not due to nonspecific electric coupling, nor to competition for anionic adsorption sites on the membrane, nor to inhibition of the H(+)-ATPase; coupling of the opposed cation and H(+) fluxes by a membrane component is the most likely explanation. Saturation kinetics have been observed for both Na(+)/H(+) and K(+)/H(+) antiport in Atriplex. Moreover, additive effects are obtained when Na(+) is supplied together with saturating concentrations of K(+), and vice versa, suggesting that separate antiporters for Na(+) and for K(+) may be operating. In the case of both Atriplex and Gossypium evidence was obtained suggesting the presence of antiporters in both plasmalemma and tonoplast.

Method of Adjusting Acoustic Impedances for Impedance-Tunable Acoustic Segments

NASA Technical Reports Server (NTRS)

Jones, Kennie H (Inventor); Nark, Douglas M. (Inventor); Jones, Michael G. (Inventor); Parrott, Tony L. (Inventor); Lodding, Kenneth N. (Inventor)

2012-01-01

A method is provided for making localized decisions and taking localized actions to achieve a global solution. In an embodiment of the present invention, acoustic impedances for impedance-tunable acoustic segments are adjusted. A first acoustic segment through an N-th acoustic segment are defined. To start the process, the first acoustic segment is designated as a leader and a noise-reducing impedance is determined therefor. This is accomplished using (i) one or more metrics associated with the acoustic wave at the leader, and (ii) the metric(s) associated with the acoustic wave at the N-th acoustic segment. The leader, the N-th acoustic segment, and each of the acoustic segments exclusive of the leader and the N-th acoustic segment, are tuned to the noise-reducing impedance. The current leader is then excluded from subsequent processing steps. The designation of leader is then given one of the remaining acoustic segments, and the process is repeated for each of the acoustic segments through an (N-1)-th one of the acoustic segments.

Intertwining operator realization of non-relativistic holography

NASA Astrophysics Data System (ADS)

Aizawa, N.; Dobrev, V. K.

2010-04-01

We give a group-theoretic interpretation of non-relativistic holography as equivalence between representations of the Schrödinger algebra describing bulk fields and boundary fields. Our main result is the explicit construction of the boundary-to-bulk operators in the framework of representation theory (without specifying any action). Further we show that these operators and the bulk-to-boundary operators are intertwining operators. In analogy to the relativistic case, we show that each bulk field has two boundary fields with conjugated conformal weights. These fields are related by another intertwining operator given by a two-point function on the boundary. Analogously to the relativistic result of Klebanov-Witten we give the conditions when both boundary fields are physical. Finally, we recover in our formalism earlier non-relativistic results for scalar fields by Son and others.

Quasi-three-dimensional particle imaging with digital holography.

PubMed

Kemppinen, Osku; Heinson, Yuli; Berg, Matthew

2017-05-01

In this work, approximate three-dimensional structures of microparticles are generated with digital holography using an automated focus method. This is done by stacking a collection of silhouette-like images of a particle reconstructed from a single in-line hologram. The method enables estimation of the particle size in the longitudinal and transverse dimensions. Using the discrete dipole approximation, the method is tested computationally by simulating holograms for a variety of particles and attempting to reconstruct the known three-dimensional structure. It is found that poor longitudinal resolution strongly perturbs the reconstructed structure, yet the method does provide an approximate sense for the structure's longitudinal dimension. The method is then applied to laboratory measurements of holograms of single microparticles and their scattering patterns.

Translational illusion of acoustic sources by transformation acoustics.

PubMed

Sun, Fei; Li, Shichao; He, Sailing

2017-09-01

An acoustic illusion of creating a translated acoustic source is designed by utilizing transformation acoustics. An acoustic source shifter (ASS) composed of layered acoustic metamaterials is designed to achieve such an illusion. A practical example where the ASS is made with naturally available materials is also given. Numerical simulations verify the performance of the proposed device. The designed ASS may have some applications in, e.g., anti-sonar detection.

Optical encryption of multiple three-dimensional objects based on multiple interferences and single-pixel digital holography

NASA Astrophysics Data System (ADS)

Wang, Ying; Liu, Qi; Wang, Jun; Wang, Qiong-Hua

2018-03-01

We present an optical encryption method of multiple three-dimensional objects based on multiple interferences and single-pixel digital holography. By modifying the Mach–Zehnder interferometer, the interference of the multiple objects beams and the one reference beam is used to simultaneously encrypt multiple objects into a ciphertext. During decryption, each three-dimensional object can be decrypted independently without having to decrypt other objects. Since the single-pixel digital holography based on compressive sensing theory is introduced, the encrypted data of this method is effectively reduced. In addition, recording fewer encrypted data can greatly reduce the bandwidth of network transmission. Moreover, the compressive sensing essentially serves as a secret key that makes an intruder attack invalid, which means that the system is more secure than the conventional encryption method. Simulation results demonstrate the feasibility of the proposed method and show that the system has good security performance. Project supported by the National Natural Science Foundation of China (Grant Nos. 61405130 and 61320106015).

Entanglement entropy in Galilean conformal field theories and flat holography.

PubMed

Bagchi, Arjun; Basu, Rudranil; Grumiller, Daniel; Riegler, Max

2015-03-20

We present the analytical calculation of entanglement entropy for a class of two-dimensional field theories governed by the symmetries of the Galilean conformal algebra, thus providing a rare example of such an exact computation. These field theories are the putative holographic duals to theories of gravity in three-dimensional asymptotically flat spacetimes. We provide a check of our field theory answers by an analysis of geodesics. We also exploit the Chern-Simons formulation of three-dimensional gravity and adapt recent proposals of calculating entanglement entropy by Wilson lines in this context to find an independent confirmation of our results from holography.

Wavelength scanning digital interference holography for high-resolution ophthalmic imaging

NASA Astrophysics Data System (ADS)

Potcoava, Mariana C.; Kim, M. K.; Kay, Christine N.

2009-02-01

An improved digital interference holography (DIH) technique suitable for fundus images is proposed. This technique incorporates a dispersion compensation algorithm to compensate for the unknown axial length of the eye. Using this instrument we acquired successfully tomographic fundus images in human eye with narrow axial resolution less than 5μm. The optic nerve head together with the surrounding retinal vasculature were constructed. We were able to quantify a depth of 84μm between the retinal fiber and the retinal pigmented epithelium layers. DIH provides high resolution 3D information which could potentially aid in guiding glaucoma diagnosis and treatment.

Three-dimensional imaging of micro-specimen by optical scanning holography

NASA Astrophysics Data System (ADS)

Liu, Jung-Ping; Tsou, Cheng-Hao

2017-04-01

Optical scanning holography (OSH) is a scanning-type digital holographic technique. In OSH, a heterodyne interference pattern is generated to raster scan the object. OSH can be operated in the incoherent mode and thus is able to record a fluorescence hologram. In addition, resolution of the OSH is proportional to the density of the interference pattern. Here we use a high-NA microscope objective to generate a dynamic Fresnel zone plate to record a hologram of micro-specimen. The achieved transverse resolution and longitudinal resolution are 0.78μm and 3.1μm, respectively.

Comparison of Thermal Detector Arrays for Off-Axis THz Holography and Real-Time THz Imaging

PubMed Central

Hack, Erwin; Valzania, Lorenzo; Gäumann, Gregory; Shalaby, Mostafa; Hauri, Christoph P.; Zolliker, Peter

2016-01-01

In terahertz (THz) materials science, imaging by scanning prevails when low power THz sources are used. However, the application of array detectors operating with high power THz sources is increasingly reported. We compare the imaging properties of four different array detectors that are able to record THz radiation directly. Two micro-bolometer arrays are designed for infrared imaging in the 8–14 μm wavelength range, but are based on different absorber materials (i) vanadium oxide; (ii) amorphous silicon; (iii) a micro-bolometer array optimized for recording THz radiation based on silicon nitride; and (iv) a pyroelectric array detector for THz beam profile measurements. THz wavelengths of 96.5 μm, 118.8 μm, and 393.6 μm from a powerful far infrared laser were used to assess the technical performance in terms of signal to noise ratio, detector response and detectivity. The usefulness of the detectors for beam profiling and digital holography is assessed. Finally, the potential and limitation for real-time digital holography are discussed. PMID:26861341

Comparison of Thermal Detector Arrays for Off-Axis THz Holography and Real-Time THz Imaging.

PubMed

Hack, Erwin; Valzania, Lorenzo; Gäumann, Gregory; Shalaby, Mostafa; Hauri, Christoph P; Zolliker, Peter

2016-02-06

In terahertz (THz) materials science, imaging by scanning prevails when low power THz sources are used. However, the application of array detectors operating with high power THz sources is increasingly reported. We compare the imaging properties of four different array detectors that are able to record THz radiation directly. Two micro-bolometer arrays are designed for infrared imaging in the 8-14 μm wavelength range, but are based on different absorber materials (i) vanadium oxide; (ii) amorphous silicon; (iii) a micro-bolometer array optimized for recording THz radiation based on silicon nitride; and (iv) a pyroelectric array detector for THz beam profile measurements. THz wavelengths of 96.5 μm, 118.8 μm, and 393.6 μm from a powerful far infrared laser were used to assess the technical performance in terms of signal to noise ratio, detector response and detectivity. The usefulness of the detectors for beam profiling and digital holography is assessed. Finally, the potential and limitation for real-time digital holography are discussed.

Phase measurement error in summation of electron holography series.

PubMed

McLeod, Robert A; Bergen, Michael; Malac, Marek

2014-06-01

Off-axis electron holography is a method for the transmission electron microscope (TEM) that measures the electric and magnetic properties of a specimen. The electrostatic and magnetic potentials modulate the electron wavefront phase. The error in measurement of the phase therefore determines the smallest observable changes in electric and magnetic properties. Here we explore the summation of a hologram series to reduce the phase error and thereby improve the sensitivity of electron holography. Summation of hologram series requires independent registration and correction of image drift and phase wavefront drift, the consequences of which are discussed. Optimization of the electro-optical configuration of the TEM for the double biprism configuration is examined. An analytical model of image and phase drift, composed of a combination of linear drift and Brownian random-walk, is derived and experimentally verified. The accuracy of image registration via cross-correlation and phase registration is characterized by simulated hologram series. The model of series summation errors allows the optimization of phase error as a function of exposure time and fringe carrier frequency for a target spatial resolution. An experimental example of hologram series summation is provided on WS2 fullerenes. A metric is provided to measure the object phase error from experimental results and compared to analytical predictions. The ultimate experimental object root-mean-square phase error is 0.006 rad (2π/1050) at a spatial resolution less than 0.615 nm and a total exposure time of 900 s. The ultimate phase error in vacuum adjacent to the specimen is 0.0037 rad (2π/1700). The analytical prediction of phase error differs with the experimental metrics by +7% inside the object and -5% in the vacuum, indicating that the model can provide reliable quantitative predictions. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

Photoelectron Diffraction and Holography Studies of 2D Materials and Interfaces

NASA Astrophysics Data System (ADS)

Kuznetsov, Mikhail V.; Ogorodnikov, Ilya I.; Usachov, Dmitry Yu.; Laubschat, Clemens; Vyalikh, Denis V.; Matsui, Fumihiko; Yashina, Lada V.

2018-06-01

Photoelectron diffraction (XPD) and holography (XPH) are powerful spectroscopic methods that allow comprehensive exploration and characterization of certain structural properties of materials, in particular those of 2D systems and interfaces. Recent developments in XPD and XPH are especially impressive when they are applied to partially disordered systems such as intercalation compounds, doped graphene, buffer layers or adsorbates and imperfectly ordered germanene and phoshporene. In our brief review, we sum up the advances in XPD and XPH studies of 2D materials and discuss the unique opportunities granted by these two interrelated methods.

Enhancing depth of focus in tilted microfluidics channels by digital holography.

PubMed

Matrecano, Marcella; Paturzo, Melania; Finizio, Andrea; Ferraro, Pietro

2013-03-15

In this Letter we propose a method to enhance the limited depth of field (DOF) in optical imaging systems, through digital holography. The proposed approach is based on the introduction of a cubic phase plate into the diffraction integral, analogous to what occurs in white-light imaging systems. By this approach we show that it is possible to improve the DOF and to recover the extended focus image of a tilted object in a single reconstruction step. Moreover, we demonstrate the possibility of obtaining well-focused biological cells flowing into a tilted microfluidic channel.

Three-Dimensional Imaging by Self-Reference Single-Channel Digital Incoherent Holography

PubMed Central

Rosen, Joseph; Kelner, Roy

2016-01-01

Digital holography offers a reliable and fast method to image a three-dimensional scene from a single perspective. This article reviews recent developments of self-reference single-channel incoherent hologram recorders. Hologram recorders in which both interfering beams, commonly referred to as the signal and the reference beams, originate from the same observed objects are considered as self-reference systems. Moreover, the hologram recorders reviewed herein are configured in a setup of a single channel interferometer. This unique configuration is achieved through the use of one or more spatial light modulators. PMID:28757811

The elimination of zero-order diffraction of 10.6 μm infrared digital holography

NASA Astrophysics Data System (ADS)

Liu, Ning; Yang, Chao

2017-05-01

A new method of eliminating the zero-order diffraction in infrared digital holography has been raised in this paper. Usually in the reconstruction of digital holography, the spatial frequency of the infrared thermal imager, such as microbolometer, cannot be compared to the common visible CCD or CMOS devices. The infrared imager suffers the problems of large pixel size and low spatial resolution, which cause the zero-order diffraction a severe influence of the reconstruction process of digital holograms. The zero-order diffraction has very large energy and occupies the central region in the spectrum domain. In this paper, we design a new filtering strategy to overcome this problem. This filtering strategy contains two kinds of filtering process which are the Gaussian low-frequency filter and the high-pass phase averaging filter. With the correct set of the calculating parameters, these filtering strategies can work effectively on the holograms and fully eliminate the zero-order diffraction, as well as the two crossover bars shown in the spectrum domain. Detailed explanation and discussion about the new method have been proposed in this paper, and the experiment results are also demonstrated to prove the performance of this method.

Fundamentals of Acoustics. Psychoacoustics and Hearing. Acoustical Measurements

NASA Technical Reports Server (NTRS)

Begault, Durand R.; Ahumada, Al (Technical Monitor)

1997-01-01

These are 3 chapters that will appear in a book titled "Building Acoustical Design", edited by Charles Salter. They are designed to introduce the reader to fundamental concepts of acoustics, particularly as they relate to the built environment. "Fundamentals of Acoustics" reviews basic concepts of sound waveform frequency, pressure, and phase. "Psychoacoustics and Hearing" discusses the human interpretation sound pressure as loudness, particularly as a function of frequency. "Acoustic Measurements" gives a simple overview of the time and frequency weightings for sound pressure measurements that are used in acoustical work.

Comparison of Different Measurement Technologies for the In-Flight Assessment of Radiated Acoustic Intensity

NASA Technical Reports Server (NTRS)

Klos, Jacob; Palumbo, Daniel L.; Buehrle, Ralph D.; Williams, Earl G.; Valdivia, Nicolas; Herdic, Peter C.; Sklanka, Bernard

2005-01-01

A series of tests was planned and conducted in the Interior Noise Test Facility at Boeing Field, on the NASA Aries 757 flight research aircraft, and in the Structural Acoustic Loads and Transmission Facility at NASA Langley Research Center. These tests were designed to answer several questions concerning the use of array methods in flight. One focus of the tests was determining whether and to what extent array methods could be used to identify the effects of an acoustical treatment applied to a limited portion of an aircraft fuselage. Another focus of the tests was to verify that the arrays could be used to localize and quantify a known source purposely placed in front of the arrays. Thus the issues related to backside sources and flanking paths present in the complicated sound field were addressed during these tests. These issues were addressed through the use of reference transducers, both accelerometers mounted to the fuselage and microphones in the cabin, that were used to correlate the pressure holograms. measured by the microphone arrays using either SVD methods or partial coherence methods. This correlation analysis accepts only energy that is coherent with the sources sensed by the reference transducers, allowing a noise control engineer to only identify and study those vibratory sources of interest. The remainder of this paper will present a detailed description of the test setups that were used in this test sequence and typical results of the NAH/IBEM analysis used to reconstruct the sound fields. Also, a comparison of data obtained in the laboratory environments and during flights of the 757 aircraft will be made.

Na+/H+ and K+/H+ Antiport in Root Membrane Vesicles Isolated from the Halophyte Atriplex and the Glycophyte Cotton 1

PubMed Central

Hassidim, Miriam; Braun, Yael; Lerner, Henri R.; Reinhold, Leonora

1990-01-01

Proton fluxes have been followed into and out of membrane vesicles isolated from the roots of the halophyte Atriplex nummularia and the glycophyte Gossypium hirsutum, with the aid of the ΔpH probe [14C]methylamine. Evidence is presented for the operation of Na+/H+ and K+/H+ antiporters in the membranes of both plants. Cation supply after a pH gradient has been set up across the vesicle membrane (either as a result of providing ATP to the H+-ATPase or by imposing an artificial pH gradient) brings about dissipation of the ΔpH, but does not depolarize the membrane potential as observed in similar experiments, but in the absence of Cl−, using the ΔΨ probe SCN−. Cation/H+ exchange is thus indicated. This exchange is not due to nonspecific electric coupling, nor to competition for anionic adsorption sites on the membrane, nor to inhibition of the H+-ATPase; coupling of the opposed cation and H+ fluxes by a membrane component is the most likely explanation. Saturation kinetics have been observed for both Na+/H+ and K+/H+ antiport in Atriplex. Moreover, additive effects are obtained when Na+ is supplied together with saturating concentrations of K+, and vice versa, suggesting that separate antiporters for Na+ and for K+ may be operating. In the case of both Atriplex and Gossypium evidence was obtained suggesting the presence of antiporters in both plasmalemma and tonoplast. PMID:16667918

Functional Characterization of Na+/H+ Exchangers of Intracellular Compartments Using Proton-killing Selection to Express Them at the Plasma Membrane

PubMed Central

Monet, Michael; Birgy-Barelli, Eléonore; Léna, Isabelle; Counillon, Laurent

2015-01-01

Endosomal acidification is critical for a wide range of processes, such as protein recycling and degradation, receptor desensitization, and neurotransmitter loading in synaptic vesicles. This acidification is described to be mediated by proton ATPases, coupled to ClC chloride transporters. Highly-conserved electroneutral protons transporters, the Na+/H+ exchangers (NHE) 6, 7 and 9 are also expressed in these compartments. Mutations in their genes have been linked with human cognitive and neurodegenerative diseases. Paradoxically, their roles remain elusive, as their intracellular localization has prevented detailed functional characterization. This manuscript shows a method to solve this problem. This consists of the selection of mutant cell lines, capable of surviving acute cytosolic acidification by retaining intracellular NHEs at the plasma membrane. It then depicts two complementary protocols to measure the ion selectivity and activity of these exchangers: (i) one based on intracellular pH measurements using fluorescence video microscopy, and (ii) one based on the fast kinetics of lithium uptake. Such protocols can be extrapolated to measure other non-electrogenic transporters. Furthermore, the selection procedure presented here generates cells with an intracellular retention defective phenotype. Therefore these cells will also express other vesicular membrane proteins at the plasma membrane. The experimental strategy depicted here may therefore constitute a potentially powerful tool to study other intracellular proteins that will be then expressed at the plasma membrane together with the vesicular Na+/H+ exchangers used for the selection. PMID:25867523

Functional characterization of Na+/H+ exchangers of intracellular compartments using proton-killing selection to express them at the plasma membrane.

PubMed

Milosavljevic, Nina; Poët, Mallorie; Monet, Michael; Birgy-Barelli, Eléonore; Léna, Isabelle; Counillon, Laurent

2015-03-30

Endosomal acidification is critical for a wide range of processes, such as protein recycling and degradation, receptor desensitization, and neurotransmitter loading in synaptic vesicles. This acidification is described to be mediated by proton ATPases, coupled to ClC chloride transporters. Highly-conserved electroneutral protons transporters, the Na+/H+ exchangers (NHE) 6, 7 and 9 are also expressed in these compartments. Mutations in their genes have been linked with human cognitive and neurodegenerative diseases. Paradoxically, their roles remain elusive, as their intracellular localization has prevented detailed functional characterization. This manuscript shows a method to solve this problem. This consists of the selection of mutant cell lines, capable of surviving acute cytosolic acidification by retaining intracellular NHEs at the plasma membrane. It then depicts two complementary protocols to measure the ion selectivity and activity of these exchangers: (i) one based on intracellular pH measurements using fluorescence video microscopy, and (ii) one based on the fast kinetics of lithium uptake. Such protocols can be extrapolated to measure other non-electrogenic transporters. Furthermore, the selection procedure presented here generates cells with an intracellular retention defective phenotype. Therefore these cells will also express other vesicular membrane proteins at the plasma membrane. The experimental strategy depicted here may therefore constitute a potentially powerful tool to study other intracellular proteins that will be then expressed at the plasma membrane together with the vesicular Na+/H+ exchangers used for the selection.

Applicability of Time-Averaged Holography for Micro-Electro-Mechanical System Performing Non-Linear Oscillations

PubMed Central

Palevicius, Paulius; Ragulskis, Minvydas; Palevicius, Arvydas; Ostasevicius, Vytautas

2014-01-01

Optical investigation of movable microsystem components using time-averaged holography is investigated in this paper. It is shown that even a harmonic excitation of a non-linear microsystem may result in an unpredictable chaotic motion. Analytical results between parameters of the chaotic oscillations and the formation of time-averaged fringes provide a deeper insight into computational and experimental interpretation of time-averaged MEMS holograms. PMID:24451467

Optical sectioning for optical scanning holography using phase-space filtering with Wigner distribution functions.

PubMed

Kim, Hwi; Min, Sung-Wook; Lee, Byoungho; Poon, Ting-Chung

2008-07-01

We propose a novel optical sectioning method for optical scanning holography, which is performed in phase space by using Wigner distribution functions together with the fractional Fourier transform. The principle of phase-space optical sectioning for one-dimensional signals, such as slit objects, and two-dimensional signals, such as rectangular objects, is first discussed. Computer simulation results are then presented to substantiate the proposed idea.

Magnetic Oscillations Mark Sites of Magnetic Transients in an Acoustically Active Flare

NASA Astrophysics Data System (ADS)

Lindsey, Charles A.; Donea, A.; Hudson, H. S.; Martinez Oliveros, J.; Hanson, C.

2011-05-01

The flare of 2011 February 15, in NOAA AR11158, was the first acoustically active flare of solar cycle 24, and the first observed by the Solar Dynamics Observatory (SDO). It was exceptional in a number of respects (Kosovichev 2011a,b). Sharp ribbon-like transient Doppler, and magnetic signatures swept over parts of the active region during the impulsive phase of the flare. We apply seismic holography to a 2-hr time series of HMI observations encompassing the flare. The acoustic source distribution appears to have been strongly concentrated in a single highly compact penumbral region in which the continuum-intensity signature was unusually weak. The line-of-sight magnetic transient was strong in parts of the active region, but relatively weak in the seismic-source region. On the other hand, the neighbourhoods of the regions visited by the strongest magnetic transients maintained conspicuous 5-minutes-period variations in the line of sight magnetic signature for the full 2-hr duration of the time series, before the flare as well as after. We apply standard helioseismic control diagnostics for clues as to the physics underlying 5-minute magnetic oscillations in regions conducive to magnetic transients during a flare and consider the prospective development of this property as an indicator of flare potentiality on some time scale. We make use of high-resolution data from AIA, using diffracted images where necessary to obtain good photometry where the image is otherwise saturated. This is relevant to seismic emission driven by thick-target heating in the absence of back-warming. We also use RHESSI imaging spectroscopy to compare the source distributions of HXR and seismic emission.

Retrieving acoustic energy densities and local pressure amplitudes in microfluidics by holographic time-lapse imaging.

PubMed

Cacace, Teresa; Bianco, Vittorio; Paturzo, Melania; Memmolo, Pasquale; Vassalli, Massimo; Fraldi, Massimiliano; Mensitieri, Giuseppe; Ferraro, Pietro

2018-06-26

The development of techniques able to characterize and map the pressure field is crucial for the widespread use of acoustofluidic devices in biotechnology and lab-on-a-chip platforms. In fact, acoustofluidic devices are powerful tools for driving precise manipulation of microparticles and cells in microfluidics in non-contact modality. Here, we report a full and accurate characterization of the movement of particles subjected to acoustophoresis in a microfluidic environment by holographic imaging. The particle displacement along the direction of the ultrasound wave propagation, coinciding with the optical axis, is observed and investigated. Two resonance frequencies are explored, varying for each the amplitude of the applied signal. The trajectories of individual tracers, accomplished by holographic measurements, are fitted with the theoretical model thus allowing the retrieval of the acoustic energy densities and pressure amplitudes through full holographic analysis. The absence of prior calibration, being independent of the object shape and the possibility of implementing automatic analysis make the use of holography very appealing for applications in devices for biotechnologies.

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.

Acoustic calibration apparatus for calibrating plethysmographic acoustic pressure sensors

NASA Technical Reports Server (NTRS)

Zuckerwar, Allan J. (Inventor); Davis, David C. (Inventor)

1995-01-01

An apparatus for calibrating an acoustic sensor is described. The apparatus includes a transmission material having an acoustic impedance approximately matching the acoustic impedance of the actual acoustic medium existing when the acoustic sensor is applied in actual in-service conditions. An elastic container holds the transmission material. A first sensor is coupled to the container at a first location on the container and a second sensor coupled to the container at a second location on the container, the second location being different from the first location. A sound producing device is coupled to the container and transmits acoustic signals inside the container.

Acoustic calibration apparatus for calibrating plethysmographic acoustic pressure sensors

NASA Technical Reports Server (NTRS)

Zuckerwar, Allan J. (Inventor); Davis, David C. (Inventor)

1994-01-01

An apparatus for calibrating an acoustic sensor is described. The apparatus includes a transmission material having an acoustic impedance approximately matching the acoustic impedance of the actual acoustic medium existing when the acoustic sensor is applied in actual in-service conditions. An elastic container holds the transmission material. A first sensor is coupled to the container at a first location on the container and a second sensor coupled to the container at a second location on the container, the second location being different from the first location. A sound producing device is coupled to the container and transmits acoustic signals inside the container.

North Pacific Acoustic Laboratory and Deep Water Acoustics

DTIC Science & Technology

2015-09-30

range acoustic systems, whether for acoustic surveillance, communication, or remote sensing of the ocean interior . The data from the NPAL network, and...1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. North Pacific Acoustic Laboratory and Deep Water... Acoustics PI James A. Mercer Applied Physics Laboratory, University of Washington 1013 NE 40th Street Seattle, WA 98105 phone: (206) 543-1361 fax

Rapamycin Inhibition of mTOR Reduces Levels of the Na+/H+ Exchanger 3 in Intestines of Mice and Humans, Leading to Diarrhea

PubMed Central

Yang, Jun; Zhao, Xiaofeng; Patel, Archana; Potru, Rachana; Azizi-Ghannad, Sadra; Dolinger, Michael; Mazurkiewicz, Joseph; Conti, David; Jones, David; Huang, Yunfei; Zhu, Xinjun

2016-01-01

Background & Aims The immunosuppressant rapamycin frequently causes non-infectious diarrhea in recipients of organ transplants. We investigated the mechanisms of this process. Methods We performed a retrospective analysis of renal transplant recipients treated with rapamycin from 2003 through 2010 at Albany Medical College, collecting data on serum levels of rapamycin. Levels of the Na+/H+ exchanger 3 (NHE3) were measured in human ileal biopsies from patients who did and did not receive rapamycin (controls), in ileum tissues from rats or mice given rapamycin, and in mice with intestine-specific disruption of Mtor (mTORf/f:Villin-cre mice) or Atg7 (Atg7flox/flox; Villin-Cre). Exchange activity and intestinal water absorption were measured using a pH-sensitive dye and small intestine perfusion, respectively. Results Episodes of non-infectious diarrhea occurred in organ recipients following increases in serum levels of rapamycin. Expression of NHE3 was reduced in the ileal brush border of patients with diarrhea. In rats and mice, continuous administration of low doses of rapamycin reduced levels of NHE3 in intestinal tissues; this effect was not observed in mice with intestinal deletion of ATG7, indicating that autophagy is required for the reduction. Administration of single high doses of rapamycin to mice, to model the spikes in rapamycin levels that occur in patients with severe diarrheal episodes, resulted in reduced phosphorylation of S6 and AKT in ileal tissues, indicating inhibition of the mTOR complex (mTORC1 and mTORC2). Intestines of mice with intestine-specific deletion of mTOR were dilated and contained large amount of liquid stools; they also had reduced levels of total NHE3 and NHERF1, compared with control mice. We observed a significant reduction in Na+/H+ exchange activity in ileum tissues from these mice. Conclusions Rapamycin inhibition of mTOR reduces levels of NHE3 and Na+/H+ exchange activity in intestinal tissues of patients and rodents. This

Rapamycin Inhibition of mTOR Reduces Levels of the Na+/H+ Exchanger 3 in Intestines of Mice and Humans, Leading to Diarrhea.

PubMed

Yang, Jun; Zhao, Xiaofeng; Patel, Archana; Potru, Rachana; Azizi-Ghannad, Sadra; Dolinger, Michael; Cao, James; Bartholomew, Catherine; Mazurkiewicz, Joseph; Conti, David; Jones, David; Huang, Yunfei; Zhu, Xinjun Cindy

2015-07-01

The immunosuppressant rapamycin frequently causes noninfectious diarrhea in organ transplant recipients. We investigated the mechanisms of this process. We performed a retrospective analysis of renal transplant recipients treated with rapamycin from 2003 through 2010 at Albany Medical College, collecting data on serum levels of rapamycin. Levels of the Na+/H+ exchanger 3 (NHE3) were measured in human ileal biopsy specimens from patients who did and did not receive rapamycin (controls), in ileum tissues from rats or mice given rapamycin, and in mice with intestine-specific disruption of mammalian target of rapamycin (Mtor) (mTOR(f/f):Villin-cre mice) or Atg7 (Atg7(flox/flox); Villin-Cre). Exchange activity and intestinal water absorption were measured using a pH-sensitive dye and small intestine perfusion, respectively. Episodes of noninfectious diarrhea occurred in organ recipients after increases in serum levels of rapamycin. The expression of NHE3 was reduced in the ileal brush border of patients with diarrhea. In rats and mice, continuous administration of low doses of rapamycin reduced levels of NHE3 in intestinal tissues; this effect was not observed in mice with intestinal deletion of ATG7, indicating that autophagy is required for the reduction. Administration of single high doses of rapamycin to mice, to model the spikes in rapamycin levels that occur in patients with severe diarrheal episodes, resulted in reduced phosphorylation of S6 and AKT in ileal tissues, indicating inhibition of the mTOR complex (mTORC1 and mTORC2). The intestines of mice with intestine-specific deletion of mTOR were dilated and contained large amounts of liquid stools; they also had reduced levels of total NHE3 and NHERF1 compared with control mice. We observed a significant reduction in Na(+)/H(+) exchange activity in ileum tissues from these mice. Rapamycin inhibition of mTOR reduces levels of NHE3 and Na(+)/H(+) exchange activity in intestinal tissues of patients and rodents

High-resolution analytical imaging and electron holography of magnetite particles in amyloid cores of Alzheimer’s disease

PubMed Central

Plascencia-Villa, Germán; Ponce, Arturo; Collingwood, Joanna F.; Arellano-Jiménez, M. Josefina; Zhu, Xiongwei; Rogers, Jack T.; Betancourt, Israel; José-Yacamán, Miguel; Perry, George

2016-01-01

Abnormal accumulation of brain metals is a key feature of Alzheimer’s disease (AD). Formation of amyloid-β plaque cores (APC) is related to interactions with biometals, especially Fe, Cu and Zn, but their particular structural associations and roles remain unclear. Using an integrative set of advanced transmission electron microscopy (TEM) techniques, including spherical aberration-corrected scanning transmission electron microscopy (Cs-STEM), nano-beam electron diffraction, electron holography and analytical spectroscopy techniques (EDX and EELS), we demonstrate that Fe in APC is present as iron oxide (Fe3O4) magnetite nanoparticles. Here we show that Fe was accumulated primarily as nanostructured particles within APC, whereas Cu and Zn were distributed through the amyloid fibers. Remarkably, these highly organized crystalline magnetite nanostructures directly bound into fibrillar Aβ showed characteristic superparamagnetic responses with saturated magnetization with circular contours, as observed for the first time by off-axis electron holography of nanometer scale particles. PMID:27121137

Quantification of Magnetic Surface and Edge States in an FeGe Nanostripe by Off-Axis Electron Holography

NASA Astrophysics Data System (ADS)

Song, Dongsheng; Li, Zi-An; Caron, Jan; Kovács, András; Tian, Huanfang; Jin, Chiming; Du, Haifeng; Tian, Mingliang; Li, Jianqi; Zhu, Jing; Dunin-Borkowski, Rafal E.

2018-04-01

Whereas theoretical investigations have revealed the significant influence of magnetic surface and edge states on Skyrmonic spin texture in chiral magnets, experimental studies of such chiral states remain elusive. Here, we study chiral edge states in an FeGe nanostripe experimentally using off-axis electron holography. Our results reveal the magnetic-field-driven formation of chiral edge states and their penetration lengths at 95 and 240 K. We determine values of saturation magnetization MS by analyzing the projected in-plane magnetization distributions of helices and Skyrmions. Values of MS inferred for Skyrmions are lower by a few percent than those for helices. We attribute this difference to the presence of chiral surface states, which are predicted theoretically in a three-dimensional Skyrmion model. Our experiments provide direct quantitative measurements of magnetic chiral boundary states and highlight the applicability of state-of-the-art electron holography for the study of complex spin textures in nanostructures.

High-resolution analytical imaging and electron holography of magnetite particles in amyloid cores of Alzheimer’s disease

NASA Astrophysics Data System (ADS)

Plascencia-Villa, Germán; Ponce, Arturo; Collingwood, Joanna F.; Arellano-Jiménez, M. Josefina; Zhu, Xiongwei; Rogers, Jack T.; Betancourt, Israel; José-Yacamán, Miguel; Perry, George

2016-04-01

Abnormal accumulation of brain metals is a key feature of Alzheimer’s disease (AD). Formation of amyloid-β plaque cores (APC) is related to interactions with biometals, especially Fe, Cu and Zn, but their particular structural associations and roles remain unclear. Using an integrative set of advanced transmission electron microscopy (TEM) techniques, including spherical aberration-corrected scanning transmission electron microscopy (Cs-STEM), nano-beam electron diffraction, electron holography and analytical spectroscopy techniques (EDX and EELS), we demonstrate that Fe in APC is present as iron oxide (Fe3O4) magnetite nanoparticles. Here we show that Fe was accumulated primarily as nanostructured particles within APC, whereas Cu and Zn were distributed through the amyloid fibers. Remarkably, these highly organized crystalline magnetite nanostructures directly bound into fibrillar Aβ showed characteristic superparamagnetic responses with saturated magnetization with circular contours, as observed for the first time by off-axis electron holography of nanometer scale particles.

Self-interference digital holography with a geometric-phase hologram lens.

PubMed

Choi, KiHong; Yim, Junkyu; Yoo, Seunghwi; Min, Sung-Wook

2017-10-01

Self-interference digital holography (SIDH) is actively studied because the hologram acquisition under the incoherent illumination condition is available. The key component in this system is wavefront modulating optics, which modulates an incoming object wave into two different wavefront curvatures. In this Letter, the geometric-phase hologram lens is introduced in the SIDH system to perform as a polarization-sensitive wavefront modulator and a single-path beam splitter. This special optics has several features, such as high transparency, a modulation efficiency up to 99%, a thinness of a few millimeters, and a flat structure. The demonstration system is devised, and the numerical reconstruction results from an acquired complex hologram are presented.

New fiber optics illumination system for application to electronics holography

NASA Astrophysics Data System (ADS)

Sciammarella, Cesar A.

1995-08-01

The practical application of electronic holography requires the use of fiber optics. The need of employing coherent fiber optics imposes restrictions in the efficient use of laser light. This paper proposes a new solution to this problem. The proposed method increases the efficiency in the use of the laser light and simplifies the interface between the laser source and the fiber optics. This paper will present the theory behind the proposed method. A discussion of the effect of the different parameters that influence the formation of interference fringes is presented. Limitations and results that can be achieved are given. An example of application is presented.

Absolute Scale Quantitative Off-Axis Electron Holography at Atomic Resolution

NASA Astrophysics Data System (ADS)

Winkler, Florian; Barthel, Juri; Tavabi, Amir H.; Borghardt, Sven; Kardynal, Beata E.; Dunin-Borkowski, Rafal E.

2018-04-01

An absolute scale match between experiment and simulation in atomic-resolution off-axis electron holography is demonstrated, with unknown experimental parameters determined directly from the recorded electron wave function using an automated numerical algorithm. We show that the local thickness and tilt of a pristine thin WSe2 flake can be measured uniquely, whereas some electron optical aberrations cannot be determined unambiguously for a periodic object. The ability to determine local specimen and imaging parameters directly from electron wave functions is of great importance for quantitative studies of electrostatic potentials in nanoscale materials, in particular when performing in situ experiments and considering that aberrations change over time.

Wavefront modulation and subwavelength diffractive acoustics with an acoustic metasurface.

PubMed

Xie, Yangbo; Wang, Wenqi; Chen, Huanyang; Konneker, Adam; Popa, Bogdan-Ioan; Cummer, Steven A

2014-11-24

Metasurfaces are a family of novel wavefront-shaping devices with planar profile and subwavelength thickness. Acoustic metasurfaces with ultralow profile yet extraordinary wave manipulating properties would be highly desirable for improving the performance of many acoustic wave-based applications. However, designing acoustic metasurfaces with similar functionality to their electromagnetic counterparts remains challenging with traditional metamaterial design approaches. Here we present a design and realization of an acoustic metasurface based on tapered labyrinthine metamaterials. The demonstrated metasurface can not only steer an acoustic beam as expected from the generalized Snell's law, but also exhibits various unique properties such as conversion from propagating wave to surface mode, extraordinary beam-steering and apparent negative refraction through higher-order diffraction. Such designer acoustic metasurfaces provide a new design methodology for acoustic signal modulation devices and may be useful for applications such as acoustic imaging, beam steering, ultrasound lens design and acoustic surface wave-based applications.

Acoustically Induced Vibration of Structures: Reverberant Vs. Direct Acoustic Testing

NASA Technical Reports Server (NTRS)

Kolaini, Ali R.; O'Connell, Michael R.; Tsoi, Wan B.

2009-01-01

Large reverberant chambers have been used for several decades in the aerospace industry to test larger structures such as solar arrays and reflectors to qualify and to detect faults in the design and fabrication of spacecraft and satellites. In the past decade some companies have begun using direct near field acoustic testing, employing speakers, for qualifying larger structures. A limited test data set obtained from recent acoustic tests of the same hardware exposed to both direct and reverberant acoustic field testing has indicated some differences in the resulting structural responses. In reverberant acoustic testing, higher vibration responses were observed at lower frequencies when compared with the direct acoustic testing. In the case of direct near field acoustic testing higher vibration responses appeared to occur at higher frequencies as well. In reverberant chamber testing and direct acoustic testing, standing acoustic modes of the reverberant chamber or the speakers and spacecraft parallel surfaces can strongly couple with the fundamental structural modes of the test hardware. In this paper data from recent acoustic testing of flight hardware, that yielded evidence of acoustic standing wave coupling with structural responses, are discussed in some detail. Convincing evidence of the acoustic standing wave/structural coupling phenomenon will be discussed, citing observations from acoustic testing of a simple aluminum plate. The implications of such acoustic coupling to testing of sensitive flight hardware will be discussed. The results discussed in this paper reveal issues with over or under testing of flight hardware that could pose unanticipated structural and flight qualification issues. Therefore, it is of paramount importance to understand the structural modal coupling with standing acoustic waves that has been observed in both methods of acoustic testing. This study will assist the community to choose an appropriate testing method and test setup in

Novel Perspectives on the Characterization of Species-Dependent Optical Signatures of Bacterial Colonies by Digital Holography.

PubMed

Buzalewicz, Igor; Kujawińska, Małgorzata; Krauze, Wojciech; Podbielska, Halina

2016-01-01

The use of light diffraction for the microbiological diagnosis of bacterial colonies was a significant breakthrough with widespread implications for the food industry and clinical practice. We previously confirmed that optical sensors for bacterial colony light diffraction can be used for bacterial identification. This paper is focused on the novel perspectives of this method based on digital in-line holography (DIH), which is able to reconstruct the amplitude and phase properties of examined objects, as well as the amplitude and phase patterns of the optical field scattered/diffracted by the bacterial colony in any chosen observation plane behind the object from single digital hologram. Analysis of the amplitude and phase patterns inside a colony revealed its unique optical properties, which are associated with the internal structure and geometry of the bacterial colony. Moreover, on a computational level, it is possible to select the desired scattered/diffracted pattern within the entire observation volume that exhibits the largest amount of unique, differentiating bacterial features. These properties distinguish this method from the already proposed sensing techniques based on light diffraction/scattering of bacterial colonies. The reconstructed diffraction patterns have a similar spatial distribution as the recorded Fresnel patterns, previously applied for bacterial identification with over 98% accuracy, but they are characterized by both intensity and phase distributions. Our results using digital holography provide new optical discriminators of bacterial species revealed in one single step in form of new optical signatures of bacterial colonies: digital holograms, reconstructed amplitude and phase patterns, as well as diffraction patterns from all observation space, which exhibit species-dependent features. To the best of our knowledge, this is the first report on bacterial colony analysis via digital holography and our study represents an innovative approach

Novel Perspectives on the Characterization of Species-Dependent Optical Signatures of Bacterial Colonies by Digital Holography

PubMed Central

Buzalewicz, Igor; Kujawińska, Małgorzata; Krauze, Wojciech; Podbielska, Halina

2016-01-01

The use of light diffraction for the microbiological diagnosis of bacterial colonies was a significant breakthrough with widespread implications for the food industry and clinical practice. We previously confirmed that optical sensors for bacterial colony light diffraction can be used for bacterial identification. This paper is focused on the novel perspectives of this method based on digital in-line holography (DIH), which is able to reconstruct the amplitude and phase properties of examined objects, as well as the amplitude and phase patterns of the optical field scattered/diffracted by the bacterial colony in any chosen observation plane behind the object from single digital hologram. Analysis of the amplitude and phase patterns inside a colony revealed its unique optical properties, which are associated with the internal structure and geometry of the bacterial colony. Moreover, on a computational level, it is possible to select the desired scattered/diffracted pattern within the entire observation volume that exhibits the largest amount of unique, differentiating bacterial features. These properties distinguish this method from the already proposed sensing techniques based on light diffraction/scattering of bacterial colonies. The reconstructed diffraction patterns have a similar spatial distribution as the recorded Fresnel patterns, previously applied for bacterial identification with over 98% accuracy, but they are characterized by both intensity and phase distributions. Our results using digital holography provide new optical discriminators of bacterial species revealed in one single step in form of new optical signatures of bacterial colonies: digital holograms, reconstructed amplitude and phase patterns, as well as diffraction patterns from all observation space, which exhibit species-dependent features. To the best of our knowledge, this is the first report on bacterial colony analysis via digital holography and our study represents an innovative approach

Physical Principles of the Method for Determination of Geometrical Characteristics and Particle Recognition in Digital Holography

NASA Astrophysics Data System (ADS)

Dyomin, V. V.; Polovtsev, I. G.; Davydova, A. Yu.

2018-03-01

The physical principles of a method for determination of geometrical characteristics of particles and particle recognition based on the concepts of digital holography, followed by processing of the particle images reconstructed from the digital hologram, using the morphological parameter are reported. An example of application of this method for fast plankton particle recognition is given.

Overview of Three-Dimensional Atomic-Resolution Holography and Imaging Techniques: Recent Advances in Local-Structure Science

NASA Astrophysics Data System (ADS)

Daimon, Hiroshi

2018-06-01

Local three-dimensional (3D) atomic arrangements without periodicity have not been able to be studied until recently. Recently, several holographies and related techniques have been developed to reveal the 3D atomic arrangement around specific atoms with no translational symmetry. This review gives an overview of these new local 3D atomic imaging techniques.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 experimentalmore » fronts. A particular emphasis will be on novel structure determinations with atomic resolution using photoelectrons.« less

Quantum critical charge response from higher derivatives in holography

NASA Astrophysics Data System (ADS)

Witczak-Krempa, William

2014-04-01

We extend the range of possibilities for the charge response in the quantum critical regime in 2 + 1D using holography, and compare them with field theory and recent quantum Monte Carlo results. We show that a family of (infinitely many) higher derivative terms in the gravitational bulk leads to behavior far richer than what was previously obtained. For example, we prove that the conductivity becomes unbounded, undermining previously obtained constraints. We further find a nontrivial and infinite set of theories that have a self-dual conductivity. Particle-vortex or S duality plays a key role; notably, it maps theories with a finite number of bulk terms to ones with an infinite number. Many properties, such as sum rules and stability conditions, are proven.

Simultaneous two-wavelength tri-window common-path digital holography

NASA Astrophysics Data System (ADS)

Liu, Lei; Shan, Mingguang; Zhong, Zhi

2018-06-01

Two-wavelength common-path off-axis digital holography is proposed with a tri-window in a single shot. It is established using a standard 4f optical image system with a 2D Ronchi grating placed outside the Fourier plane. The input plane consists of three windows: one for the object and the other two for reference. Aided by a spatial filter together with two orthogonal linear polarizers in the Fourier plane, the two-wavelength information is encoded into a multiplexed hologram with two orthogonal spatial frequencies that enable full separation of spectral information in the digital Fourier space without resolution loss. Theoretical analysis and experimental results illustrate that our approach can simultaneously perform quantitative phase imaging at two wavelengths.

Phase retrieval without unwrapping by single-shot dual-wavelength digital holography

NASA Astrophysics Data System (ADS)

Min, Junwei; Yao, Baoli; Zhou, Meiling; Guo, Rongli; Lei, Ming; Yang, Yanlong; Dan, Dan; Yan, Shaohui; Peng, Tong

2014-12-01

A phase retrieval method by using single-shot dual-wavelength digital holography is proposed. Each single wavelength hologram is extracted from the color CCD recorded hologram at one exposure, and the unwrapped phase image of object can be reconstructed directly. Different from the traditional multiple wavelength phase unwrapping techniques, any single complex wave-fronts at different wavelengths have no need to be calculated any more. Thus, the phase retrieval is computationally fast and straightforward, and the limitations on the total optical path difference are significantly relaxed. The practicability of the proposed method is demonstrated by both simulated and experimental results.

Experimental feasibility of multistatic holography for breast microwave radar image reconstruction.

PubMed

Flores-Tapia, Daniel; Rodriguez, Diego; Solis, Mario; Kopotun, Nikita; Latif, Saeed; Maizlish, Oleksandr; Fu, Lei; Gui, Yonsheng; Hu, Can-Ming; Pistorius, Stephen

2016-08-01

The goal of this study was to assess the experimental feasibility of circular multistatic holography, a novel breast microwave radar reconstruction approach, using experimental datasets recorded using a preclinical experimental setup. The performance of this approach was quantitatively evaluated by calculating the signal to clutter ratio (SCR), contrast to clutter ratio (CCR), tumor to fibroglandular response ratio (TFRR), spatial accuracy, and reconstruction time. Five datasets were recorded using synthetic phantoms with the dielectric properties of breast tissue in the 1-6 GHz range using a custom radar system developed by the authors. The datasets contained synthetic structures that mimic the dielectric properties of fibroglandular breast tissues. Four of these datasets the authors covered an 8 mm inclusion that emulated a tumor. A custom microwave radar system developed at the University of Manitoba was used to record the radar responses from the phantoms. The datasets were reconstructed using the proposed multistatic approach as well as with a monostatic holography approach that has been previously shown to yield the images with the highest contrast and focal quality. For all reconstructions, the location of the synthetic tumors in the experimental setup was consistent with the position in the both the monostatic and multistatic reconstructed images. The average spatial error was less than 4 mm, which is half the spatial resolution of the data acquisition system. The average SCR, CCR, and TFRR of the images reconstructed with the multistatic approach were 15.0, 9.4, and 10.0 dB, respectively. In comparison, monostatic images obtained using the datasets from the same experimental setups yielded average SCR, CCR, and TFRR values of 12.8, 4.9, and 5.9 dB. No artifacts, defined as responses generated by the reconstruction method of at least half the energy of the tumor signatures, were noted in the multistatic reconstructions. The average execution time of the

Observation of the magnetic flux and three-dimensional structure of skyrmion lattices by electron holography.

PubMed

Park, Hyun Soon; Yu, Xiuzhen; Aizawa, Shinji; Tanigaki, Toshiaki; Akashi, Tetsuya; Takahashi, Yoshio; Matsuda, Tsuyoshi; Kanazawa, Naoya; Onose, Yoshinori; Shindo, Daisuke; Tonomura, Akira; Tokura, Yoshinori

2014-05-01

Skyrmions are nanoscale spin textures that are viewed as promising candidates as information carriers in future spintronic devices. Skyrmions have been observed using neutron scattering and microscopy techniques. Real-space imaging using electrons is a straightforward way to interpret spin configurations by detecting the phase shifts due to electromagnetic fields. Here, we report the first observation by electron holography of the magnetic flux and the three-dimensional spin configuration of a skyrmion lattice in Fe(0.5)Co(0.5)Si thin samples. The magnetic flux inside and outside a skyrmion was directly visualized and the handedness of the magnetic flux flow was found to be dependent on the direction of the applied magnetic field. The electron phase shifts φ in the helical and skyrmion phases were determined using samples with a stepped thickness t (from 55 nm to 510 nm), revealing a linear relationship (φ = 0.00173 t). The phase measurements were used to estimate the three-dimensional structures of both the helical and skyrmion phases, demonstrating that electron holography is a useful tool for studying complex magnetic structures and for three-dimensional, real-space mapping of magnetic fields.

Hyper-polyhedron model applied to molecular screening of guanidines as Na/H exchange inhibitors.

PubMed

Bao, Xin-Hua; Lu, Wen-Cong; Liu, Liang; Chen, Nian-Yi

2003-05-01

To investigate structure-activity relationships of N-(3-Oxo-3,4-dihydro-2H-benzo[1,4]oxazine-6-carbonyl) guanidines in Na/H exchange inhibitory activities and probe into a new method of the computer-aided molecular screening. The hyper-polyhedron model (HPM) was proposed in our lab. The samples with probably higher activities could be determined in such a way that their representing points should be in the hyper-polyhedron region where all known samples with high activities were distributed. And the predictive ability of different methods available was tested by the cross-validation experiment. The accurate rate of molecular screening of N-(3-Oxo-3,4-dihydro-2H-benzo[1,4]oxazine-6-carbonyl) guanidines by HPM was much higher than that obtained by PCA (principal component analysis) and Fisher methods for the data set available here. Therefore, HPM could be used as a powerful tool for screening new compounds with probably higher activities.

Colour computer-generated holography for point clouds utilizing the Phong illumination model.

PubMed

Symeonidou, Athanasia; Blinder, David; Schelkens, Peter

2018-04-16

A technique integrating the bidirectional reflectance distribution function (BRDF) is proposed to generate realistic high-quality colour computer-generated holograms (CGHs). We build on prior work, namely a fast computer-generated holography method for point clouds that handles occlusions. We extend the method by integrating the Phong illumination model so that the properties of the objects' surfaces are taken into account to achieve natural light phenomena such as reflections and shadows. Our experiments show that rendering holograms with the proposed algorithm provides realistic looking objects without any noteworthy increase to the computational cost.

Evaluation of Optical Sonography for Real-Time Breast Imaging and Biopsy Guidance

DTIC Science & Technology

2002-08-01

supported through images of target standards and subjective validation using images of human anatomy . Keywords: Diffractive Energy Imaging...real-time imaging technology that uses the principles of acoustical holography to produce unique images of the human anatomy . The ADI technology is

Low photon count based digital holography for quadratic phase cryptography.

PubMed

Muniraj, Inbarasan; Guo, Changliang; Malallah, Ra'ed; Ryle, James P; Healy, John J; Lee, Byung-Geun; Sheridan, John T

2017-07-15

Recently, the vulnerability of the linear canonical transform-based double random phase encryption system to attack has been demonstrated. To alleviate this, we present for the first time, to the best of our knowledge, a method for securing a two-dimensional scene using a quadratic phase encoding system operating in the photon-counted imaging (PCI) regime. Position-phase-shifting digital holography is applied to record the photon-limited encrypted complex samples. The reconstruction of the complex wavefront involves four sparse (undersampled) dataset intensity measurements (interferograms) at two different positions. Computer simulations validate that the photon-limited sparse-encrypted data has adequate information to authenticate the original data set. Finally, security analysis, employing iterative phase retrieval attacks, has been performed.

Holography, Gravity and Condensed Matter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hartnoll, Sean

Over the five years of funding from this grant, I produced 26 publications. These include a book-long monograph on "Holographic Quantum Matter" that is currently in press with MIT press. The remainder were mostly published in Physical Review Letters, the Journal of High Energy Physics, Nature Physics, Classical and Quantum Gravity and Physical Review B. Over this period, the field of holography applied to condensed matter physics developed from a promising theoretical approach to a mature conceptual and practical edifice, whose ideas were realized in experiments. My own work played a central role in this development. In particular, in themore » final year of this grant, I co-authored two experimental papers in which ideas that I had developed in earlier years were shown to usefully describe transport in strongly correlated materials — these papers were published in Science and in the Proceedings of the National Academy of Sciences (obviously my contribution to these papers was theoretical). My theoretical work in this period developed several new directions of research that have proven to be influential. These include (i) The construction of highly inhomogeneous black hole event horizons, realizing disordered fixed points and describing new regimes of classical gravity, (ii) The conjecture of a bound on diffusivities that could underpin transport in strongly interacting media — an idea which may be proven in the near future and has turned out to be intimately connected to studies of quantum chaos in black holes and strongly correlated media, (iii) The characterization of new forms of hydrodynamic transport, e.g. with phase-disordered order parameters. These studies pertain to key open questions in our understanding of how non-quasiparticle, intrinsically strongly interacting systems can behave. In addition to the interface between holography and strongly interacting condensed matter systems, I made several advances on understanding the role of entanglement in

Self-made silver-bromide-based emulsions for users in holography: manufacturing, processing, and application

NASA Astrophysics Data System (ADS)

Duenkel, Lothar; Eichler, Juergen; Ackermann, Gerhard; Schneeweiss, Claudia

2004-06-01

Holography is the most fascinating technology for three-dimensional imaging. But despite of many decades of research, the seek for an ideal recording material has never been given up. From all ultra-fine materials, silver bromide emulsions with very small grain sizes have the highest sensitivity. In recent years however, many traditional manufacturers discontinued their production. Meanwhile, newcomers succeeded in manufacturing emulsions which are very suitable for holography, concerning extremely high resolution, brigthness and sensitivity1. But two problems may still linger: First, the deficient market situation for production and application on this field. Second, the reputation of the system of being extremely complicated for laboratory preparation. In such a crucial situation, the authors have succeeded in presenting a laboratory procedure for making do-it-yourself materials available to any expert who is well versed in holography, and who disposes of normal darkroom equipment2. The methodology is based on precipitation using the traditional double-jet method according to Thiry and predecessors3. But sensitization is carried out by a diffusion process according to the procedure as proposed by Blyth et al.4 Thus, precipitation and coating on one side and sensitization on the other one are separated strictly from one another. Efficient desaltation is an important process too, warranting the high opto-mechanical quality of the layer. The material has been sensitzed for HeNe-Laser radiation (632,8 nm) only up to now. The mean diameter of the silver bromide grains is about 15 nm, as determined by transmission electron microscopy (TEM). Phillips-Bjelkhagen Ultimate (PBU) or Fe3+ rehalogenation bleach are applied successfully5-6. In final result, a new generation of holograms with ultra-high resolution, proper contrast, excellent sharpness and light brightness has been obtained. Holography belongs to an advancing technology where the search for an ideal recording

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.

Fiber-Optic Bragg Gratings and Optical Holography Compared as Vibration Detectors

NASA Technical Reports Server (NTRS)

Adamovsky, Grigory

2003-01-01

The NASA Glenn Research Center is interested in determining structural damage in engine components during flight to evaluate the health of aerospace propulsion systems. On the ground, we can use holography to detect structural damage by examining the characteristic mode shapes and frequencies of vibrating objects. We are studying the feasibility of using embedded fiber Bragg gratings (FBGs) to accomplish this goal in a flight-worthy system, by using the minimal intrusion and high sensitivity afforded by fiber optics. We have recently compared holographically imaged modes of vibrating plates with the corresponding dynamic strains detected by embedded FBGs. We constructed an experimental setup for studying the responses of FBGs to dynamic excitations. One of the plates was made of a polymer matrix composite (PMC) with an FBG embedded in it, and the other one was made of copper with surface-mounted FBGs. The instrumented plates were mounted and vibrated, and time-averaged holography was used to measure their surface displacements. Simultaneously, the signals from the FBGs were detected and sent via fiber-optic cable to a quiet location about 20 m away for interrogation. The the test configuration used for the PMC plate is shown. Experimental results are also shown. The FBG was embedded in the middle of the PMC plates, roughly within the center circular fringe in each of the interferograms shown. Two resonant excitation frequencies were used: 706 and 3062 Hz. The plot in this paper shows a larger FBG signal at the higher frequency; this is because the plate bends more at higher order resonant modes, causing higher strain. This contrasts to the smaller displacements characteristic of higher frequencies, which are measured by holographic techniques.

Acoustic sensors using microstructures tunable with energy other than acoustic energy

DOEpatents

Datskos, Panagiotis G.

2003-11-25

A sensor for detecting acoustic energy includes a microstructure tuned to a predetermined acoustic frequency and a device for detecting movement of the microstructure. A display device is operatively linked to the movement detecting device. When acoustic energy strikes the acoustic sensor, acoustic energy having a predetermined frequency moves the microstructure, where the movement is detected by the movement detecting device.

Acoustic sensors using microstructures tunable with energy other than acoustic energy

DOEpatents

Datskos, Panagiotis G.

2005-06-07

A sensor for detecting acoustic energy includes a microstructure tuned to a predetermined acoustic frequency and a device for detecting movement of the microstructure. A display device is operatively linked to the movement detecting device. When acoustic energy strikes the acoustic sensor, acoustic energy having a predetermined frequency moves the microstructure, where the movement is detected by the movement detecting device.

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.

Holographic wavefront sensor, based on diffuse Fourier holography

NASA Astrophysics Data System (ADS)

Gorelaya, Alina; Orlov, Vyacheslav; Venediktov, Vladimir

2017-09-01

Many areas of optical science and technology require fast and accurate measurement of the radiation wavefront shape. Today there are known a lot of wavefront sensor (WFS) techniques, and their number is growing up. The last years have brought a growing interest in several schematics of WFS, employing the holography principles and holographic optical elements (HOE). Some of these devices are just the improved versions of the standard and most popular Shack-Hartman WFS, while other are based on the intrinsic features of HOE. A holographic mode wavefront sensor is proposed, which makes it possible to measure up to several tens of wavefront modes. The increase in the number of measured modes is implemented using the conversion of a light wave entering the sensor into a wide diffuse light beam, which allows one to record a large number of holograms, each intended for measuring one of the modes.

Acoustic dispersive prism.

PubMed

Esfahlani, Hussein; Karkar, Sami; Lissek, Herve; Mosig, Juan R

2016-01-07

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.

Non-contact single shot elastography using line field low coherence holography

PubMed Central

Liu, Chih-Hao; Schill, Alexander; Wu, Chen; Singh, Manmohan; Larin, Kirill V.

2016-01-01

Optical elastic wave imaging is a powerful technique that can quantify local biomechanical properties of tissues. However, typically long acquisition times make this technique unfeasible for clinical use. Here, we demonstrate non-contact single shot elastographic holography using a line-field interferometer integrated with an air-pulse delivery system. The propagation of the air-pulse induced elastic wave was imaged in real time, and required a single excitation for a line-scan measurement. Results on tissue-mimicking phantoms and chicken breast muscle demonstrated the feasibility of this technique for accurate assessment of tissue biomechanical properties with an acquisition time of a few milliseconds using parallel acquisition. PMID:27570694

Acoustic energy harvesting based on a planar acoustic metamaterial

NASA Astrophysics Data System (ADS)

Qi, Shuibao; Oudich, Mourad; Li, Yong; Assouar, Badreddine

2016-06-01

We theoretically report on an innovative and practical acoustic energy harvester based on a defected acoustic metamaterial (AMM) with piezoelectric material. The idea is to create suitable resonant defects in an AMM to confine the strain energy originating from an acoustic incidence. This scavenged energy is converted into electrical energy by attaching a structured piezoelectric material into the defect area of the AMM. We show an acoustic energy harvester based on a meta-structure capable of producing electrical power from an acoustic pressure. Numerical simulations are provided to analyze and elucidate the principles and the performances of the proposed system. A maximum output voltage of 1.3 V and a power density of 0.54 μW/cm3 are obtained at a frequency of 2257.5 Hz. The proposed concept should have broad applications on energy harvesting as well as on low-frequency sound isolation, since this system acts as both acoustic insulator and energy harvester.

Chirped pulse digital holography for measuring the sequence of ultrafast optical wavefronts

NASA Astrophysics Data System (ADS)

Karasawa, Naoki

2018-04-01

Optical setups for measuring the sequence of ultrafast optical wavefronts using a chirped pulse as a reference wave in digital holography are proposed and analyzed. In this method, multiple ultrafast object pulses are used to probe the temporal evolution of ultrafast phenomena and they are interfered with a chirped reference wave to record a digital hologram. Wavefronts at different times can be reconstructed separately from the recorded hologram when the reference pulse can be treated as a quasi-monochromatic wave during the pulse width of each object pulse. The feasibility of this method is demonstrated by numerical simulation.

Topography of hidden objects using THz digital holography with multi-beam interferences.

PubMed

Valzania, Lorenzo; Zolliker, Peter; Hack, Erwin

2017-05-15

We present a method for the separation of the signal scattered from an object hidden behind a THz-transparent sample in the framework of THz digital holography in reflection. It combines three images of different interference patterns to retrieve the amplitude and phase distribution of the object beam. Comparison of simulated with experimental images obtained from a metallic resolution target behind a Teflon plate demonstrates that the interference patterns can be described in the simple form of three-beam interference. Holographic reconstructions after the application of the method show a considerable improvement compared to standard reconstructions exclusively based on Fourier transform phase retrieval.

Is dust acoustic wave a new plasma acoustic mode?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dwivedi, C.B.

1997-09-01

In this Brief Communication, the claim of the novelty of the dust acoustic wave in a dusty plasma within the constant dust charge model is questioned. Conceptual lacunas behind the claim have been highlighted and appropriate physical arguments have been forwarded against the claim. It is demonstrated that the so-called dust acoustic wave could better be termed as a general acoustic fluctuation response with a dominant characteristic feature of the acoustic-like mode (ALM) fluctuation response reported by Dwivedi {ital et al.} [J. Plasma Phys. {bold 41}, 219 (1989)]. It is suggested that both correct and more usable nomenclature of themore » ALM should be the so-called acoustic mode. {copyright} {ital 1997 American Institute of Physics.}« less

Characterization of electrical properties in axial Si-Ge nanowire heterojunctions using off-axis electron holography and atom-probe tomography

DOE PAGES

Gan, Zhaofeng; Perea, Daniel E.; Yoo, Jinkyoung; ...

2016-09-13

Doped Si-Ge nanowire (NW) heterojunctions were grown using the vapor-liquid-solid method with AuGa and Au catalyst particles. Transmission electron microscopy and off-axis electron holography (EH) were used to characterize the nanostructure and to measure the electrostatic potential profile across the junction resulting from electrically active dopants, while atom-probe tomography (APT) was used to determine the Si, Ge and total (active and inactive) dopant concentration profiles. A comparison of the measured potential profile with simulations indicated that Ga dopants unintentionally introduced during AuGa catalyst growth were electronically inactive despite APT results that showed considerable amounts of Ga in the Si region.more » 10% P in Ge and 100% B in Si were estimated to be activated, which was corroborated by in situ electron-holography biasing experiments. This combination of EH, APT, in situ biasing and simulations allows a better knowledge and understanding of the electrically active dopant distributions in NWs.« less

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

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.

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.

Dual-wavelength phase-shifting digital holography selectively extracting wavelength information from wavelength-multiplexed holograms.

PubMed

Tahara, Tatsuki; Mori, Ryota; Kikunaga, Shuhei; Arai, Yasuhiko; Takaki, Yasuhiro

2015-06-15

Dual-wavelength phase-shifting digital holography that selectively extracts wavelength information from five wavelength-multiplexed holograms is presented. Specific phase shifts for respective wavelengths are introduced to remove the crosstalk components and extract only the object wave at the desired wavelength from the holograms. Object waves in multiple wavelengths are selectively extracted by utilizing 2π ambiguity and the subtraction procedures based on phase-shifting interferometry. Numerical results show the validity of the proposed technique. The proposed technique is also experimentally demonstrated.

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.

Strings on AdS_3 x S^3 and the Plane-Wave Limit. Issues on PP-Wave/CFT Holography

NASA Astrophysics Data System (ADS)

Zapata, Oswaldo

2005-10-01

In this thesis we give explicit results for bosonic string amplitudes on AdS_3 x S^3 and the corresponding plane-wave limit. We also analyze the consequences of our approach for understanding holography in this set up, as well as its possible generalization to other models.

Speaker verification system using acoustic data and non-acoustic data

DOEpatents

Gable, Todd J [Walnut Creek, CA; Ng, Lawrence C [Danville, CA; Holzrichter, John F [Berkeley, CA; Burnett, Greg C [Livermore, CA

2006-03-21

A method and system for speech characterization. One embodiment includes a method for speaker verification which includes collecting data from a speaker, wherein the data comprises acoustic data and non-acoustic data. The data is used to generate a template that includes a first set of "template" parameters. The method further includes receiving a real-time identity claim from a claimant, and using acoustic data and non-acoustic data from the identity claim to generate a second set of parameters. The method further includes comparing the first set of parameters to the set of parameters to determine whether the claimant is the speaker. The first set of parameters and the second set of parameters include at least one purely non-acoustic parameter, including a non-acoustic glottal shape parameter derived from averaging multiple glottal cycle waveforms.

High-acoustic-impedance tantalum oxide layers for insulating acoustic reflectors.

PubMed

Capilla, Jose; Olivares, Jimena; Clement, Marta; Sangrador, Jesús; Iborra, Enrique; Devos, Arnaud

2012-03-01

This work describes the assessment of the acoustic properties of sputtered tantalum oxide films intended for use as high-impedance films of acoustic reflectors for solidly mounted resonators operating in the gigahertz frequency range. The films are grown by sputtering a metallic tantalum target under different oxygen and argon gas mixtures, total pressures, pulsed dc powers, and substrate biases. The structural properties of the films are assessed through infrared absorption spectroscopy and X-ray diffraction measurements. Their acoustic impedance is assessed by deriving the mass density from X-ray reflectometry measurements and the acoustic velocity from picosecond acoustic spectroscopy and the analysis of the frequency response of the test resonators.

Na+/H+ exchange activity during phagocytosis in human neutrophils: role of Fcgamma receptors and tyrosine kinases

PubMed Central

1996-01-01

In neutrophils, binding and phagocytosis facilitate subsequent intracellular killing of microorganisms. Activity of Na+/H+ exchangers (NHEs) participates in these events, especially in regulation of intracellular pH (pHi) by compensating for the H+ load generated by the respiratory burst. Despite the importance of these functions, comparatively little is known regarding the nature and regulation of NHE(s) in neutrophils. The purpose of this study was to identify which NHE(s) are expressed in neutrophils and to elucidate the mechanisms regulating their activity during phagocytosis. Exposure of cells to the phagocytic stimulus opsonized zymosan (OpZ) induced a transient cytosolic acidification followed by a prolonged alkalinization. The latter was inhibited in Na+-free medium and by amiloride analogues and therefore was due to activation of Na+/H+ exchange. Reverse transcriptase PCR and cDNA sequencing demonstrated that mRNA for the NHE-1 but not for NHE-2, 3, or 4 isoforms of the exchanger was expressed. Immunoblotting of purified plasma membranes with isoform- specific antibodies confirmed the presence of NHE-1 protein in neutrophils. Since phagocytosis involves Fcgamma (FcgammaR) and complement receptors such as CR3 (a beta2 integrin) which are linked to pathways involving alterations in intracellular [Ca2+]i and tyrosine phosphorylation, we studied these pathways in relation to activation of NHE-1. Cross-linking of surface bound antibodies (mAb) directed against FcgammaRs (FcgammaRII > FcgammaRIII) but not beta2 integrins induced an amiloride-sensitive cytosolic alkalinization. However, anti-beta2 integrin mAb diminished OpZ-induced alkalinization suggesting that NHE- 1 activation involved cooperation between integrins and FcgammaRs. The tyrosine kinase inhibitors genistein and herbimycin blocked cytosolic alkalinization after OpZ or FcgammaR cross-linking suggesting that tyrosine phosphorylation was involved in NHE-I activation. An increase in [Ca2+]i was not

Acoustics of Korean percussion instruments: Pyeongyeong and pyeonjong

NASA Astrophysics Data System (ADS)

Yoo, Junehee

2005-11-01

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

Genes encoding the vacuolar Na+/H+ exchanger and flower coloration.

PubMed

Yamaguchi, T; Fukada-Tanaka, S; Inagaki, Y; Saito, N; Yonekura-Sakakibara, K; Tanaka, Y; Kusumi, T; Iida, S

2001-05-01

Vacuolar pH plays an important role in flower coloration: an increase in the vacuolar pH causes blueing of flower color. In the Japanese morning glory (Ipomoea nil or Pharbitis nil), a shift from reddish-purple buds to blue open flowers correlates with an increase in the vacuolar pH. We describe details of the characterization of a mutant that carries a recessive mutation in the Purple (Pr) gene encoding a vacuolar Na+/H+ exchanger termed InNHX1. The genome of I. nil carries one copy of the Pr (or InNHX1) gene and its pseudogene, and it showed functional complementation to the yeast nhx1 mutation. The mutant of I. nil, called purple (pr), showed a partial increase in the vacuolar pH during flower-opening and its reddish-purple buds change into purple open flowers. The vacuolar pH in the purple open flowers of the mutant was significantly lower than that in the blue open flowers. The InNHX1 gene is most abundantly expressed in the petals at around 12 h before flower-opening, accompanying the increase in the vacuolar pH for the blue flower coloration. No such massive expression was observed in the petunia flowers. Since the NHX1 genes that promote the transport of Na+ into the vacuoles have been regarded to be involved in salt tolerance by accumulating Na+ in the vacuoles, we can add a new biological role for blue flower coloration in the Japanese morning glory by the vacuolar alkalization.

Impact of Acoustic Standing Waves on Structural Responses: Reverberant Acoustic Testing (RAT) vs. Direct Field Acoustic Testing (DFAT)

NASA Technical Reports Server (NTRS)

Kolaini, Ali R.; Doty, Benjamin; Chang, Zensheu

2012-01-01

Loudspeakers have been used for acoustic qualification of spacecraft, reflectors, solar panels, and other acoustically responsive structures for more than a decade. Limited measurements from some of the recent speaker tests used to qualify flight hardware have indicated significant spatial variation of the acoustic field within the test volume. Also structural responses have been reported to differ when similar tests were performed using reverberant chambers. To address the impact of non-uniform acoustic field on structural responses, a series of acoustic tests were performed using a flat panel and a 3-ft cylinder exposed to the field controlled by speakers and repeated in a reverberant chamber. The speaker testing was performed using multi-input-single-output (MISO) and multi-input-multi-output (MIMO) control schemes with and without the test articles. In this paper the spatial variation of the acoustic field due to acoustic standing waves and their impacts on the structural responses in RAT and DFAT (both using MISO and MIMO controls for DFAT) are discussed in some detail.

High Capacity Na+/H+ Exchange Activity in Mineralizing Osteoblasts

PubMed Central

Liu, Li; Schlesinger, Paul H.; Slack, Nicole M.; Friedman, Peter A.; Blair, Harry C.

2015-01-01

Osteoblasts synthesize bone in polarized groups of cells sealed by tight junctions. Large amounts of acid are produced as bone mineral is precipitated. We addressed the mechanism by which cells manage this acid load by measuring intracellular pH (pHi) in non-transformed osteoblasts in response to weak acid or bicarbonate loading. Basal pHi in mineralizing osteoblasts was ∼7.3 and decreased by ∼ 1.4 units upon replacing extracellular Na+ with N-methyl-d-glucamine. Loading with 40 mM acetic or propionic acids, in normal extracellular Na+, caused only mild cytosolic acidification. In contrast, in Na+-free solutions, weak acids reduced pHi dramatically. After Na+ reintroduction, pHi recovered rapidly, in keeping with Na+/H+exchanger (NHE) activity. Sodium-dependent pHi recovery from weak acid loading was inhibited by amiloride with the Ki consistent with NHEs. NHE1 and NHE6 were expressed strongly, and expression was upregulated highly, by mineralization, in human osteoblasts. Antibody labeling of mouse bone showed NHE1 on basolateral surfaces of all osteoblasts. NHE6 occurred on basolateral surfaces of osteoblasts mainly in areas of mineralization. Conversely, elevated HCO3- alkalinized osteoblasts, and pH recovered in medium containing CI-, with or without Na+, in keeping with Na+-independent CI-/HCO3- exchange. The exchanger AE2 also occurred on the basolateral surface of osteoblasts, consistent with CI-/HCO3- exchange for elimination of metabolic carbonate. Overexpression of NHE6 or knockdown of NHE1 in MG63 human osteosarcoma cells confirmed roles of NHE1 and NHE6 in maintaining pHi. We conclude that in mineralizing osteoblasts, slightly basic basal pHi is maintained, and external acid load is dissipated, by high-capacity Na+/H+ exchange via NHE1 and NHE6. PMID:21413028

An acoustic switch.

PubMed

Vanhille, Christian; Campos-Pozuelo, Cleofé

2014-01-01

The benefits derived from the development of acoustic transistors which act as switches or amplifiers have been reported in the literature. Here we propose a model of acoustic switch. We theoretically demonstrate that the device works: the input signal is totally restored at the output when the switch is on whereas the output signal nulls when the switch is off. The switch, on or off, depends on a secondary acoustic field capable to manipulate the main acoustic field. The model relies on the attenuation effect of many oscillating bubbles on the main travelling wave in the liquid, as well as on the capacity of the secondary acoustic wave to move the bubbles. This model evidences the concept of acoustic switch (transistor) with 100% efficiency. Copyright © 2013 Elsevier B.V. All rights reserved.

Acoustic tweezers via sub-time-of-flight regime surface acoustic waves.

PubMed

Collins, David J; Devendran, Citsabehsan; Ma, Zhichao; Ng, Jia Wei; Neild, Adrian; Ai, Ye

2016-07-01

Micrometer-scale acoustic waves are highly useful for refined optomechanical and acoustofluidic manipulation, where these fields are spatially localized along the transducer aperture but not along the acoustic propagation direction. In the case of acoustic tweezers, such a conventional acoustic standing wave results in particle and cell patterning across the entire width of a microfluidic channel, preventing selective trapping. We demonstrate the use of nanosecond-scale pulsed surface acoustic waves (SAWs) with a pulse period that is less than the time of flight between opposing transducers to generate localized time-averaged patterning regions while using conventional electrode structures. These nodal positions can be readily and arbitrarily positioned in two dimensions and within the patterning region itself through the imposition of pulse delays, frequency modulation, and phase shifts. This straightforward concept adds new spatial dimensions to which acoustic fields can be localized in SAW applications in a manner analogous to optical tweezers, including spatially selective acoustic tweezers and optical waveguides.

Using DSLR cameras in digital holography

NASA Astrophysics Data System (ADS)

Hincapié-Zuluaga, Diego; Herrera-Ramírez, Jorge; García-Sucerquia, Jorge

2017-08-01

In Digital Holography (DH), the size of the bidimensional image sensor to record the digital hologram, plays a key role on the performance of this imaging technique; the larger the size of the camera sensor, the better the quality of the final reconstructed image. Scientific cameras with large formats are offered in the market, but their cost and availability limit their use as a first option when implementing DH. Nowadays, DSLR cameras provide an easy-access alternative that is worthwhile to be explored. The DSLR cameras are a wide, commercial, and available option that in comparison with traditional scientific cameras, offer a much lower cost per effective pixel over a large sensing area. However, in the DSLR cameras, with their RGB pixel distribution, the sampling of information is different to the sampling in monochrome cameras usually employed in DH. This fact has implications in their performance. In this work, we discuss why DSLR cameras are not extensively used for DH, taking into account the problem reported by different authors of object replication. Simulations of DH using monochromatic and DSLR cameras are presented and a theoretical deduction for the replication problem using the Fourier theory is also shown. Experimental results of DH implementation using a DSLR camera show the replication problem.

Resolution and quality enhancement in terahertz in-line holography by sub-pixel sampling with double-distance reconstruction.

PubMed

Li, Zeyu; Li, Lei; Qin, Yu; Li, Guangbin; Wang, Du; Zhou, Xun

2016-09-05

We demonstrate the enhancement of resolution and image quality in terahertz (THz) lens-free in-line digital holography by sub-pixel sampling with double-distance reconstruction. Multiple sub-pixel shifted low-resolution (LR) holograms recorded by a pyroelectric array detector (100 μm × 100 μm pixel pitch, 124 × 124 pixels) are aligned precisely to synthesize a high-resolution (HR) hologram. By this method, the lateral resolution is no more limited by the pixel pitch, and lateral resolution of 150 μm is obtained, which corresponds to 1.26λ with respect to the illuminating wavelength of 118.8 μm (2.52 THz). Compared with other published works, to date, this is the highest resolution in THz digital holography when considering the illuminating wavelength. In addition, to suppress the twin-image and zero-order artifacts, the complex amplitude distributions of both object and illuminaing background wave fields are reconstructed simultaneously. This is achieved by iterative phase retrieval between the double HR holograms and background images at two recording planes, which does not require any constraints on object plane or a priori knowledge of the sample.

Improvement of graphite crystal analyzer for light elements on X-ray fluorescence holography measurement

NASA Astrophysics Data System (ADS)

Happo, Naohisa; Hada, Takuma; Kubota, Atsushi; Ebisu, Yoshihiro; Hosokawa, Shinya; Kimura, Koji; Tajiri, Hiroo; Matsushita, Tomohiro; Hayashi, Kouichi

2018-05-01

Using a graphite crystal analyzer, focused monochromatic fluorescent X-rays can be obtained on an X-ray fluorescence holography (XFH) measurement. To measure the holograms of elements lighter than Ti, we improved a cylindrical-type crystal analyzer and constructed a small C-shaped analyzer. Using the constructed C-shaped analyzer, a Ca Kα hologram of a fluorite single crystal was obtained, from which we reconstructed a clear atomic image. The XFH measurements for the K, Ca, and Sc elements become possible using the presently constructed analyzer.

Acoustic levitation of an object larger than the acoustic wavelength.

PubMed

Andrade, Marco A B; Okina, Fábio T A; Bernassau, Anne L; Adamowski, Julio C

2017-06-01

Levitation and manipulation of objects by sound waves have a wide range of applications in chemistry, biology, material sciences, and engineering. However, the current acoustic levitation techniques are mainly restricted to particles that are much smaller than the acoustic wavelength. In this work, it is shown that acoustic standing waves can be employed to stably levitate an object much larger than the acoustic wavelength in air. The levitation of a large slightly curved object weighting 2.3 g is demonstrated by using a device formed by two 25 kHz ultrasonic Langevin transducers connected to an aluminum plate. The sound wave emitted by the device provides a vertical acoustic radiation force to counteract gravity and a lateral restoring force that ensure horizontal stability to the levitated object. In order to understand the levitation stability, a numerical model based on the finite element method is used to determine the acoustic radiation force that acts on the object.

ACOUSTICS IN ARCHITECTURAL DESIGN, AN ANNOTATED BIBLIOGRAPHY ON ARCHITECTURAL ACOUSTICS.

ERIC Educational Resources Information Center

DOELLE, LESLIE L.

THE PURPOSE OF THIS ANNOTATED BIBLIOGRAPHY ON ARCHITECTURAL ACOUSTICS WAS--(1) TO COMPILE A CLASSIFIED BIBLIOGRAPHY, INCLUDING MOST OF THOSE PUBLICATIONS ON ARCHITECTURAL ACOUSTICS, PUBLISHED IN ENGLISH, FRENCH, AND GERMAN WHICH CAN SUPPLY A USEFUL AND UP-TO-DATE SOURCE OF INFORMATION FOR THOSE ENCOUNTERING ANY ARCHITECTURAL-ACOUSTIC DESIGN…

Digital Holography and 3D Imaging: introduction to the joint feature issue in Applied Optics and Journal of the Optical Society of America B.

PubMed

Banerjee, Partha P; Osten, Wolfgang; Picart, Pascal; Cao, Liangcai; Nehmetallah, George

2017-05-01

The OSA Topical Meeting on Digital Holography and 3D Imaging (DH) was held 25-28 July 2016 in Heidelberg, Germany, as part of the Imaging Congress. Feature issues based on the DH meeting series have been released by Applied Optics (AO) since 2007. This year, AO and the Journal of the Optical Society of America B (JOSA B) jointly decided to have one such feature issue in each journal. This feature issue includes 31 papers in AO and 11 in JOSA B, and covers a large range of topics, reflecting the rapidly expanding techniques and applications of digital holography and 3D imaging. The upcoming DH meeting (DH 2017) will be held from 29 May to 1 June in Jeju Island, South Korea.

Double-resolution electron holography with simple Fourier transform of fringe-shifted holograms.

PubMed

Volkov, V V; Han, M G; Zhu, Y

2013-11-01

We propose a fringe-shifting holographic method with an appropriate image wave recovery algorithm leading to exact solution of holographic equations. With this new method the complex object image wave recovered from holograms appears to have much less traditional artifacts caused by the autocorrelation band present practically in all Fourier transformed holograms. The new analytical solutions make possible a double-resolution electron holography free from autocorrelation band artifacts and thus push the limits for phase resolution. The new image wave recovery algorithm uses a popular Fourier solution of the side band-pass filter technique, while the fringe-shifting holographic method is simple to implement in practice. Published by Elsevier B.V.

Mechanical behavior of CAD/CAM occlusal ceramic reconstruction assessed by digital color holography.

PubMed

Xia, H; Picart, P; Montresor, S; Guo, R; Li, J C; Yusuf Solieman, O; Durand, J-C; Fages, M

2018-05-21

CAD/CAM ceramic occlusal veneers are increasingly used as therapeutic options. However, little is known about their mechanical behavior under stress, as the response of the prepared tooth that supports it. The aim of this article is to use for the first time 3D color holography to evaluate the behavior of a molar occlusal veneer under stress and the response of the prepared tooth. The occlusal surface of a lower molar is prepared to receive a specific monolithic ceramic reconstruction manufactured with a chairside CAD/CAM system. Longitudinally cut samples are used to get a planar object observation and to "look inside" the tooth. A digital holographic set-up permits to obtain the contact-less and one-shot measurement of the three-dimensional displacement field at the surface of the tooth sample; stain fields are evaluated with low noise-sensitive computation. Figures show the strain fields with micro-strain units and highlight the behavior of the ROI (region of interest) in the three directions of space. The ROI are: the ceramic, the glue junction, the dentin enamel junction, dentin and enamel. The results show an excellent behavior of the restored tooth without areas of excessive stress concentrations, but also a significant involvement of the dentin enamel junction. The ceramic occlusal veneer seems to behave in accordance with the biomechanical concepts ensuring the longevity of the reconstituted tooth. 3D holography is a highly recommended method for studying dental biomechanics. Copyright © 2018 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.

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.

Acoustic neuroma

MedlinePlus

... Cerebellopontine angle tumor; Angle tumor; Hearing loss - acoustic; Tinnitus - acoustic ... that makes it hard to hear conversations Ringing ( tinnitus ) in the affected ear Less common symptoms include: ...

Double negative acoustic metastructure for attenuation of acoustic emissions

NASA Astrophysics Data System (ADS)

Kumar, Sanjay; Bhushan, Pulak; Prakash, Om; Bhattacharya, Shantanu

2018-03-01

Acoustic metamaterials hold great potential for attenuation of low frequency acoustic emissions. However, a fundamental challenge is achieving high transmission loss over a broad frequency range. In this work, we report a double negative acoustic metastructure for absorption of low frequency acoustic emissions in an aircraft. This is achieved by utilizing a periodic array of hexagonal cells interconnected with a neck and mounted with an elastic membrane on both ends. An average transmission loss of 56 dB under 500 Hz and an overall absorption of over 48% have been realized experimentally. The negative mass density is derived from the dipolar resonances created as a result of the in-phase movement of the membranes. Further, the negative bulk modulus is ascribed to the combined effect of out-of-phase acceleration of the membranes and the Helmholtz resonator. The proposed metastructure enables absorption of low frequency acoustic emissions with improved functionality that is highly desirable for varied applications.

Reducing the dimensions of acoustic devices using anti-acoustic-null media

NASA Astrophysics Data System (ADS)

Li, Borui; Sun, Fei; He, Sailing

2018-02-01

An anti-acoustic-null medium (anti-ANM), a special homogeneous medium with anisotropic mass density, is designed by transformation acoustics (TA). Anti-ANM can greatly compress acoustic space along the direction of its main axis, where the size compression ratio is extremely large. This special feature can be utilized to reduce the geometric dimensions of classic acoustic devices. For example, the height of a parabolic acoustic reflector can be greatly reduced. We also design a brass-air structure on the basis of the effective medium theory to materialize the anti-ANM in a broadband frequency range. Numerical simulations verify the performance of the proposed anti-ANM.

North Pacific Acoustic Laboratory: Deep Water Acoustic Propagation in the Philippine Sea

DTIC Science & Technology

2016-06-21

the "Special Issue on Deep-water Ocean Acoustics" in the Journal of the Acoustical Society of America (Vol. 134, No . 4, Pt. 2 of 2 , October20 13...also listed. Fourteen (14) of these publications appeared in the " Special Issue on Deep-water Ocean Acoustics" in the Journal of the Acoustical

Precision holography for N={2}^{\\ast } on S 4 from type IIB supergravity

NASA Astrophysics Data System (ADS)

Bobev, Nikolay; Gautason, Friðrik Freyr; van Muiden, Jesse

2018-04-01

We find a new supersymmetric solution of type IIB supergravity which is holographically dual to the planar limit of the four-dimensional N={2}^{\\ast } supersymmetric Yang-Mills theory on S 4. We study a probe fundamental string in this background which is dual to a supersymmetric Wilson loop in the N={2}^{\\ast } theory. Using holography we calculate the expectation value of this line operator to leading order in the 't Hooft coupling. The result is a non-trivial function of the mass parameter of the N={2}^{\\ast } theory that precisely matches the result from supersymmetric localization.

Design of a digital holography system for PFC erosion measurements on Proto-MPEX.

PubMed

Thomas, C E Tommy; Biewer, T M; Baylor, L R; Combs, S K; Meitner, S J; Rapp, J; Hillis, D L; Granstedt, E M; Majeski, R; Kaita, R

2016-11-01

A project has been started at ORNL to develop a dual-wavelength digital holography system for plasma facing component erosion measurements on prototype material plasma exposure experiment. Such a system will allow in situ real-time measurements of component erosion. Initially the system will be developed with one laser, and first experimental laboratory measurements will be made with the single laser system. In the second year of development, a second CO 2 laser will be added and measurements with the dual wavelength system will begin. Adding the second wavelength allows measurements at a much longer synthetic wavelength.

Atomic spectroscopy and holography: A combined laboratory experiment at the intermediate undergraduate level

NASA Astrophysics Data System (ADS)

Bates, Harry E.

1984-05-01

Holography is a new and exciting field that has found many applications in physics and engineering. Atomic spectroscopy has been the experimental cornerstone of modern physics and chemistry. This paper reports on an intermediate undergraduate laboratory experiment that combines fundamental ideas and techniques of both fields. The student utilizes holographic techniques to make a small sinusoidal diffraction grating and then uses this grating to analyze the spectrum of hydrogen. The Rydberg constant can be determined from the wavelength, the angle between the laser beams used to make the grating, and the observed diffractions angles of lines of the Balmer series.

Relationships between objective acoustic indices and acoustic comfort evaluation in nonacoustic spaces

NASA Astrophysics Data System (ADS)

Kang, Jian

2004-05-01

Much attention has been paid to acoustic spaces such as concert halls and recording studios, whereas research on nonacoustic buildings/spaces has been rather limited, especially from the viewpoint of acoustic comfort. In this research a series of case studies has been carried out on this topic, considering various spaces including shopping mall atrium spaces, library reading rooms, football stadia, swimming spaces, churches, dining spaces, as well as urban open public spaces. The studies focus on the relationships between objective acoustic indices such as sound pressure level and reverberation time and perceptions of acoustic comfort. The results show that the acoustic atmosphere is an important consideration in such spaces and the evaluation of acoustic comfort may vary considerably even if the objective acoustic indices are the same. It is suggested that current guidelines and technical regulations are insufficient in terms of acoustic design of these spaces, and the relationships established from the case studies between objective and subjective aspects would be useful for developing further design guidelines. [Work supported partly by the British Academy.

Virtual acoustics displays

NASA Astrophysics Data System (ADS)

Wenzel, Elizabeth M.; Fisher, Scott S.; Stone, Philip K.; Foster, Scott H.

1991-03-01

The real time acoustic display capabilities are described which were developed for the Virtual Environment Workstation (VIEW) Project at NASA-Ames. The acoustic display is capable of generating localized acoustic cues in real time over headphones. An auditory symbology, a related collection of representational auditory 'objects' or 'icons', can be designed using ACE (Auditory Cue Editor), which links both discrete and continuously varying acoustic parameters with information or events in the display. During a given display scenario, the symbology can be dynamically coordinated in real time with 3-D visual objects, speech, and gestural displays. The types of displays feasible with the system range from simple warnings and alarms to the acoustic representation of multidimensional data or events.

Virtual acoustics displays

NASA Technical Reports Server (NTRS)

Wenzel, Elizabeth M.; Fisher, Scott S.; Stone, Philip K.; Foster, Scott H.

1991-01-01

The real time acoustic display capabilities are described which were developed for the Virtual Environment Workstation (VIEW) Project at NASA-Ames. The acoustic display is capable of generating localized acoustic cues in real time over headphones. An auditory symbology, a related collection of representational auditory 'objects' or 'icons', can be designed using ACE (Auditory Cue Editor), which links both discrete and continuously varying acoustic parameters with information or events in the display. During a given display scenario, the symbology can be dynamically coordinated in real time with 3-D visual objects, speech, and gestural displays. The types of displays feasible with the system range from simple warnings and alarms to the acoustic representation of multidimensional data or events.

Simulation of Acoustics for Ares I Scale Model Acoustic Tests

NASA Technical Reports Server (NTRS)

Putnam, Gabriel; Strutzenberg, Louise L.

2011-01-01

The Ares I Scale Model Acoustics Test (ASMAT) is a series of live-fire tests of scaled rocket motors meant to simulate the conditions of the Ares I launch configuration. These tests have provided a well documented set of high fidelity acoustic measurements useful for validation including data taken over a range of test conditions and containing phenomena like Ignition Over-Pressure and water suppression of acoustics. To take advantage of this data, a digital representation of the ASMAT test setup has been constructed and test firings of the motor have been simulated using the Loci/CHEM computational fluid dynamics software. Results from ASMAT simulations with the rocket in both held down and elevated configurations, as well as with and without water suppression have been compared to acoustic data collected from similar live-fire tests. Results of acoustic comparisons have shown good correlation with the amplitude and temporal shape of pressure features and reasonable spectral accuracy up to approximately 1000 Hz. Major plume and acoustic features have been well captured including the plume shock structure, the igniter pulse transient, and the ignition overpressure.

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.

A scheme for lensless X-ray microscopy combining coherent diffraction imaging and differential corner holography.

PubMed

Capotondi, F; Pedersoli, E; Kiskinova, M; Martin, A V; Barthelmess, M; Chapman, H N

2012-10-22

We successfully use the corners of a common silicon nitride supporting window in lensless X-ray microscopy as extended references in differential holography to obtain a real space hologram of the illuminated object. Moreover, we combine this method with the iterative phasing techniques of coherent diffraction imaging to enhance the spatial resolution on the reconstructed object, and overcome the problem of missing areas in the collected data due to the presence of a beam stop, achieving a resolution close to 85 nm.

Revealing isomerism in sodium-water clusters: Photoionization spectra of Na(H2O)n (n = 2-90)

NASA Astrophysics Data System (ADS)

Dierking, Christoph W.; Zurheide, Florian; Zeuch, Thomas; Med, Jakub; Parez, Stanislav; Slavíček, Petr

2017-06-01

Soft ionization of sodium tagged polar clusters is increasingly used as a powerful technique for sizing and characterization of small aerosols with possible application, e.g., in atmospheric chemistry or combustion science. Understanding the structure and photoionization of the sodium doped clusters is critical for such applications. In this work, we report on measurements of photoionization spectra for sodium doped water clusters containing 2-90 water molecules. While most of the previous studies focused on the ionization threshold of the Na(H2O)n clusters, we provide for the first time full photoionization spectra, including the high-energy region, which are used as reference for a comparison with theory. As reported in previous work, we have seen an initial drop of the appearance ionization energy with cluster size to values of about 3.2 eV for n <5 . In the size range from n = 5 to n = 15, broad ion yield curves emerge; for larger clusters, a constant range between signal appearance (˜2.8 eV) and signal saturation (˜4.1 eV) has been observed. The measurements are interpreted with ab initio calculations and ab initio molecular dynamics simulations for selected cluster sizes (n ≤ 15). The simulations revealed theory shortfalls when aiming at quantitative agreement but allowed us identifying structural motifs consistent with the observed ionization energy distributions. We found a decrease in the ionization energy with increasing coordination of the Na atom and increasing delocalization of the Na 3s electron cloud. The appearance ionization energy is determined by isomers with fully solvated sodium and a highly delocalized electron cloud, while both fully and incompletely solvated isomers with localized electron clouds can contribute to the high energy part of the photoionization spectrum. Simulations at elevated temperatures show an increased abundance of isomers with low ionization energies, an entropic effect enabling size selective infrared action

Revealing isomerism in sodium-water clusters: Photoionization spectra of Na(H2O)n (n = 2-90).

PubMed

Dierking, Christoph W; Zurheide, Florian; Zeuch, Thomas; Med, Jakub; Parez, Stanislav; Slavíček, Petr

2017-06-28

Soft ionization of sodium tagged polar clusters is increasingly used as a powerful technique for sizing and characterization of small aerosols with possible application, e.g., in atmospheric chemistry or combustion science. Understanding the structure and photoionization of the sodium doped clusters is critical for such applications. In this work, we report on measurements of photoionization spectra for sodium doped water clusters containing 2-90 water molecules. While most of the previous studies focused on the ionization threshold of the Na(H 2 O) n clusters, we provide for the first time full photoionization spectra, including the high-energy region, which are used as reference for a comparison with theory. As reported in previous work, we have seen an initial drop of the appearance ionization energy with cluster size to values of about 3.2 eV for n<5. In the size range from n = 5 to n = 15, broad ion yield curves emerge; for larger clusters, a constant range between signal appearance (∼2.8 eV) and signal saturation (∼4.1 eV) has been observed. The measurements are interpreted with ab initio calculations and ab initio molecular dynamics simulations for selected cluster sizes (n≤ 15). The simulations revealed theory shortfalls when aiming at quantitative agreement but allowed us identifying structural motifs consistent with the observed ionization energy distributions. We found a decrease in the ionization energy with increasing coordination of the Na atom and increasing delocalization of the Na 3s electron cloud. The appearance ionization energy is determined by isomers with fully solvated sodium and a highly delocalized electron cloud, while both fully and incompletely solvated isomers with localized electron clouds can contribute to the high energy part of the photoionization spectrum. Simulations at elevated temperatures show an increased abundance of isomers with low ionization energies, an entropic effect enabling size selective infrared action

Subwavelength diffractive acoustics and wavefront manipulation with a reflective acoustic metasurface

NASA Astrophysics Data System (ADS)

Wang, Wenqi; Xie, Yangbo; Popa, Bogdan-Ioan; Cummer, Steven A.

2016-11-01

Acoustic metasurfaces provide useful wavefront shaping capabilities, such as beam steering, acoustic focusing, and asymmetric transmission, in a compact structure. Most acoustic metasurfaces described in the literature are transmissive devices and focus their performance on steering sound beam of the fundamental diffractive order. In addition, the range of incident angles studied is usually below the critical incidence predicted by generalized Snell's law of reflection. In this work, we comprehensively analyze the wave interaction with a generic periodic phase-modulating structure in order to predict the behavior of all diffractive orders, especially for cases beyond critical incidence. Under the guidance of the presented analysis, a broadband reflective metasurface is designed based on an expanded library of labyrinthine acoustic metamaterials. Various local and nonlocal wavefront shaping properties are experimentally demonstrated, and enhanced absorption of higher order diffractive waves is experimentally shown for the first time. The proposed methodology provides an accurate approach for predicting practical diffracted wave behaviors and opens a new perspective for the study of acoustic periodic structures. The designed metasurface extends the functionalities of acoustic metasurfaces and paves the way for the design of thin planar reflective structures for broadband acoustic wave manipulation and extraordinary absorption.

Digital Holography and 3D Imaging: introduction to the joint feature issue in Applied Optics and Journal of the Optical Society of America A.

PubMed

Kang, Hoonjong; Lee, Byoungho; Kozacki, Tomasz; Picart, Pascal; Situ, Guohai

2018-01-01

The OSA Topical Meeting on Digital Holography and 3D Imaging (DH) was held 29 May to 1 June 2017 in Jeju Island, South Korea. Feature issues based on the DH meeting series have been released by Applied Optics (AO) since 2007. This year, AO and the Journal of the Optical Society of America A (JOSA A) jointly decided to have one such feature issue in each journal. This feature issue includes 33 papers in AO and 9 in JOSA A and covers a large range of topics, reflecting the rapidly expanding techniques and applications of digital holography and 3D imaging. The upcoming DH meeting (DH 2018) will be held 25-28 June 2018 in Orlando, Florida, USA, as part of the OSA Imaging and Applied Optics Congress.

Digital Holography and 3D Imaging: introduction to the joint feature issue in Applied Optics and Journal of the Optical Society of America A.

PubMed

Kang, Hoonjong; Lee, Byoungho; Kozacki, Tomasz; Picart, Pascal; Situ, Guohai

2018-01-01

The OSA Topical Meeting on Digital Holography and 3D Imaging (DH) was held 29 May to 1 June 2017 on Jeju Island, South Korea. Feature issues based on the DH meeting series have been released by Applied Optics (AO) since 2007. This year, AO and the Journal of the Optical Society of America A (JOSA A) jointly decided to have one such feature issue in each journal. This feature issue includes 33 papers in AO and 9 in JOSA A and covers a large range of topics, reflecting the rapidly expanding techniques and applications of digital holography and 3D imaging. The upcoming DH meeting (DH 2018) will be held 25-28 June 2018 in Orlando, Florida, as part of the OSA Imaging and Applied Optics Congress.

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

Purification and functional reconstitution of a seven-subunit mrp-type na+/h+ antiporter.

PubMed

Morino, Masato; Suzuki, Toshiharu; Ito, Masahiro; Krulwich, Terry Ann

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(+).

Direct observation of dopant distribution in GaAs compound semiconductors using phase-shifting electron holography and Lorentz microscopy.

PubMed

Sasaki, Hirokazu; Otomo, Shinya; Minato, Ryuichiro; Yamamoto, Kazuo; Hirayama, Tsukasa

2014-06-01

Phase-shifting electron holography and Lorentz microscopy were used to map dopant distributions in GaAs compound semiconductors with step-like dopant concentration. Transmission electron microscope specimens were prepared using a triple beam focused ion beam (FIB) system, which combines a Ga ion beam, a scanning electron microscope, and an Ar ion beam to remove the FIB damaged layers. The p-n junctions were clearly observed in both under-focused and over-focused Lorentz microscopy images. A phase image was obtained by using a phase-shifting reconstruction method to simultaneously achieve high sensitivity and high spatial resolution. Differences in dopant concentrations between 1 × 10(19) cm(-3) and 1 × 10(18) cm(-3) regions were clearly observed by using phase-shifting electron holography. We also interpreted phase profiles quantitatively by considering inactive layers induced by ion implantation during the FIB process. The thickness of an inactive layer at different dopant concentration area can be measured from the phase image. © The Author 2014. Published by Oxford University Press on behalf of The Japanese Society of Microscopy. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

THz holography in reflection using a high resolution microbolometer array.

PubMed

Zolliker, Peter; Hack, Erwin

2015-05-04

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.

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 ...

High-resolution topograms of fingerprints using multiwavelength digital holography

NASA Astrophysics Data System (ADS)

Abeywickrema, Ujitha; Banerjee, Partha; Kota, Akash; Swiontek, Stephen E.; Lakhtakia, Akhlesh

2017-03-01

Fingerprint analysis is a popular identification technique due to the uniqueness of fingerprints and the convenience of recording them. The quality of a latent fingerprint on a surface can depend on various conditions, such as the time of the day, temperature, and the composition of sweat. We first developed latent fingerprints on transparent and blackened glass slides by depositing 1000-nm-thick columnar thin films (CTFs) of chalcogenide glass of nominal composition Ge28Sb12Se60. Then, we used transmission-/reflection-mode multiwavelength digital holography to construct the topograms of CTF-developed fingerprints on transparent/blackened glass slides. The two wavelengths chosen were 514.5 and 457.9 nm, yielding a synthetic wavelength of 4.1624 μm, which is sufficient to resolve pores of depths 1 to 2 μm. Thus, our method can be used to measure the level-3 details that are usually difficult to observe with most other techniques applied to latent fingerprints.

Holography demonstrations and workshops for science and engineering outreach

NASA Astrophysics Data System (ADS)

Thomas, Weston; Kruse, Kevin; Middlebrook, Christopher

2012-10-01

The SPIE/OSA Student Chapter at Michigan Technological University have developed demonstrations and workshops for science and engineering outreach. The practical approach to holography promotes the study of photonic related sciences in high school and college-aged students. An introduction to laser safety, optical laboratory practices, and basic laser coherence theory is given in order to first introduce the participants to the science behind the holograms. The students are then able to create a hologram of an item of their choice, personalizing the experience. By engaging directly, the students are able to see how the theory is applied and also enforces a higher level of attention from them so no mistakes are made in their hologram. Throughout the course participants gain an appreciation for photonics by learning how holograms operate and are constructed through hands on creation of their own holograms. This paper reviews the procedures and methods used in the demonstrations and workshop while examining the overall student experience.

Acoustic suspension system

NASA Technical Reports Server (NTRS)

Lee, M. C.; Wang, T. G. (Inventor)

1983-01-01

An acoustic levitation system is described, with single acoustic source and a small reflector to stably levitate a small object while the object is processed as by coating or heating it. The system includes a concave acoustic source which has locations on opposite sides of its axis that vibrate towards and away from a focal point to generate a converging acoustic field. A small reflector is located near the focal point, and preferably slightly beyond it, to create an intense acoustic field that stably supports a small object near the reflector. The reflector is located about one-half wavelength from the focal point and is concavely curved to a radius of curvature (L) of about one-half the wavelength, to stably support an object one-quarter wavelength (N) from the reflector.

Motion compensation and noise tolerance in phase-shifting digital in-line holography.

PubMed

Stenner, Michael D; Neifeld, Mark A

2006-05-15

We present a technique for phase-shifting digital in-line holography which compensates for lateral object motion. By collecting two frames of interference between object and reference fields with identical reference phase, one can estimate the lateral motion that occurred between frames using the cross-correlation. We also describe a very general linear framework for phase-shifting holographic reconstruction which minimizes additive white Gaussian noise (AWGN) for an arbitrary set of reference field amplitudes and phases. We analyze the technique's sensitivity to noise (AWGN, quantization, and shot), errors in the reference fields, errors in motion estimation, resolution, and depth of field. We also present experimental motion-compensated images achieving the expected resolution.

Multiwavelength digital holography with wavelength-multiplexed holograms and arbitrary symmetric phase shifts.

PubMed

Tahara, Tatsuki; Otani, Reo; Omae, Kaito; Gotohda, Takuya; Arai, Yasuhiko; Takaki, Yasuhiro

2017-05-15

We propose multiwavelength in-line digital holography with wavelength-multiplexed phase-shifted holograms and arbitrary symmetric phase shifts. We use phase-shifting interferometry selectively extracting wavelength information to reconstruct multiwavelength object waves separately from wavelength-multiplexed monochromatic images. The proposed technique obtains systems of equations for real and imaginary parts of multiwavelength object waves from the holograms by introducing arbitrary symmetric phase shifts. Then, the technique derives each complex amplitude distribution of each object wave selectively and analytically by solving the two systems of equations. We formulate the algorithm in the case of an arbitrary number of wavelengths and confirm its validity numerically and experimentally in the cases where the number of wavelengths is two and three.

Acoustic evaluation of wood quality in standing trees. Part I, Acoustic wave behavior

Treesearch

Xiping Wang; Robert J. Ross; Peter Carter

2007-01-01

Acoustic wave velocities in standing trees or live softwood species were measured by the time-of-flight (TOF) method. Tree velocities were compared with acoustic velocities measured in corresponding butt logs through a resonance acoustic method. The experimental data showed a skewed relationship between tree and log acoustic measurements. For most trees tested,...

Study of double exposure holography of the 3-dimensional character of the flow around an airfoil profile in a wind tunnel

NASA Technical Reports Server (NTRS)

Heid, G.; Stanislas, M.

1986-01-01

The tridimensional character of the flow around a profile placed between walls is demonstrated and the incidence induced with the assistance of measurements of velocities by double exposure holography is evaluated. The values obtained by the theory of Menard are compared satisfactorily to the values obtained by this experiment.

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.

Acoustic scaling: A re-evaluation of the acoustic model of Manchester Studio 7

NASA Astrophysics Data System (ADS)

Walker, R.

1984-12-01

The reasons for the reconstruction and re-evaluation of the acoustic scale mode of a large music studio are discussed. The design and construction of the model using mechanical and structural considerations rather than purely acoustic absorption criteria is described and the results obtained are given. The results confirm that structural elements within the studio gave rise to unexpected and unwanted low-frequency acoustic absorption. The results also show that at least for the relatively well understood mechanisms of sound energy absorption physical modelling of the structural and internal components gives an acoustically accurate scale model, within the usual tolerances of acoustic design. The poor reliability of measurements of acoustic absorption coefficients, is well illustrated. The conclusion is reached that such acoustic scale modelling is a valid and, for large scale projects, financially justifiable technique for predicting fundamental acoustic effects. It is not appropriate for the prediction of fine details because such small details are unlikely to be reproduced exactly at a different size without extensive measurements of the material's performance at both scales.

Acoustic Test Characterization of Melamine Foam for Usage in NASA's Payload Fairing Acoustic Attenuation Systems

NASA Technical Reports Server (NTRS)

Hughes, William O.; McNelis, Anne M.; McNelis, Mark E.

2014-01-01

The external acoustic liftoff levels predicted for NASA's future heavy lift launch vehicles are expected to be significantly higher than the environment created by today's commercial launch vehicles. This creates a need to develop an improved acoustic attenuation system for future NASA payload fairings. NASA Glenn Research Center initiated an acoustic test series to characterize the acoustic performance of melamine foam, with and without various acoustic enhancements. This testing was denoted as NEMFAT, which stands for NESC Enhanced Melamine Foam Acoustic Test, and is the subject of this paper. Both absorption and transmission loss testing of numerous foam configurations were performed at the Riverbank Acoustical Laboratory in July 2013. The NEMFAT test data provides an initial acoustic characterization and database of melamine foam for NASA. Because of its acoustic performance and lighter mass relative to fiberglass blankets, melamine foam is being strongly considered for use in the acoustic attenuation systems of NASA's future launch vehicles.

Stimulated Raman scattering holography for time-resolved imaging of methane gas.

PubMed

Amer, Eynas; Gren, Per; Edenharder, Stefan; Sjödahl, Mikael

2016-05-01

In this paper, pulsed digital holographic detection is coupled to the stimulated Raman scattering (SRS) process for imaging gases. A Q-switched Nd-YAG laser (532 nm) has been used to pump methane gas (CH₄) at pressures up to 12 bars. The frequency-tripled (355 nm) beam from the same laser was used to pump an optical parametric oscillator (OPO). The Stokes beam (from the OPO) has been tuned to 629.93 nm so that the frequency difference between the pump (532 nm) and the Stokes beams fits a Raman active vibrational mode of the methane molecule (2922  cm^-1). The pump beam has been spatially modulated with fringes produced in a Michelson interferometer. The pump and the Stokes beams were overlapped in time, space, and polarization on the gas molecules, resulting in a stimulated Raman gain of the Stokes beam and a corresponding loss of the pump beam through the SRS process. The resulting gain of the Stokes beam has been detected using pulsed digital holography by blending it with a reference beam on the detector. Two holograms of the Stokes beam, without and with the pump beam fringes present, were recorded. Intensity maps calculated from the recorded digital holograms showed amplification of the Stokes beam at the position of overlap with the pump beam fringes and the gas molecules. The gain of the Stokes beam has been separated from the background in the Fourier domain. A gain of about 4.5% at a pump beam average intensity of 4  MW/cm² and a Stokes beam intensity of 0.16  MW/cm² have been recorded at a gas pressure of 12 bars. The gain decreased linearly with decreasing gas pressure. The results show that SRS holography is a promising technique to pinpoint a specific species and record its spatial and temporal distribution.

Effects of subsampling of passive acoustic recordings on acoustic metrics.

PubMed

Thomisch, Karolin; Boebel, Olaf; Zitterbart, Daniel P; Samaran, Flore; Van Parijs, Sofie; Van Opzeeland, Ilse

2015-07-01

Passive acoustic monitoring is an important tool in marine mammal studies. However, logistics and finances frequently constrain the number and servicing schedules of acoustic recorders, requiring a trade-off between deployment periods and sampling continuity, i.e., the implementation of a subsampling scheme. Optimizing such schemes to each project's specific research questions is desirable. This study investigates the impact of subsampling on the accuracy of two common metrics, acoustic presence and call rate, for different vocalization patterns (regimes) of baleen whales: (1) variable vocal activity, (2) vocalizations organized in song bouts, and (3) vocal activity with diel patterns. To this end, above metrics are compared for continuous and subsampled data subject to different sampling strategies, covering duty cycles between 50% and 2%. The results show that a reduction of the duty cycle impacts negatively on the accuracy of both acoustic presence and call rate estimates. For a given duty cycle, frequent short listening periods improve accuracy of daily acoustic presence estimates over few long listening periods. Overall, subsampling effects are most pronounced for low and/or temporally clustered vocal activity. These findings illustrate the importance of informed decisions when applying subsampling strategies to passive acoustic recordings or analyses for a given target species.

Content-based fused off-axis object illumination direct-to-digital holography

DOEpatents

Price, Jeffery R.

2006-05-02

Systems and methods are described for content-based fused off-axis illumination direct-to-digital holography. A method includes calculating an illumination angle with respect to an optical axis defined by a focusing lens as a function of data representing a Fourier analyzed spatially heterodyne hologram; reflecting a reference beam from a reference mirror at a non-normal angle; reflecting an object beam from an object the object beam incident upon the object at the illumination angle; focusing the reference beam and the object beam at a focal plane of a digital recorder to from the content-based off-axis illuminated spatially heterodyne hologram including spatially heterodyne fringes for Fourier analysis; and digitally recording the content based off-axis illuminated spatially heterodyne hologram including spatially heterodyne fringes for Fourier analysis.

Automatic focusing in digital holography and its application to stretched holograms.

PubMed

Memmolo, P; Distante, C; Paturzo, M; Finizio, A; Ferraro, P; Javidi, B

2011-05-15

The searching and recovering of the correct reconstruction distance in digital holography (DH) can be a cumbersome and subjective procedure. Here we report on an algorithm for automatically estimating the in-focus image and recovering the correct reconstruction distance for speckle holograms. We have tested the approach in determining the reconstruction distances of stretched digital holograms. Stretching a hologram with a variable elongation parameter makes it possible to change the in-focus distance of the reconstructed image. In this way, the proposed algorithm can be verified at different distances by dispensing the recording of different holograms. Experimental results are shown with the aim of demonstrating the usefulness of the proposed method, and a comparative analysis has been performed with respect to other existing algorithms developed for DH. © 2011 Optical Society of America

Formulation of the rotational transformation of wave fields and their application to digital holography.

PubMed

Matsushima, Kyoji

2008-07-01

Rotational transformation based on coordinate rotation in Fourier space is a useful technique for simulating wave field propagation between nonparallel planes. This technique is characterized by fast computation because the transformation only requires executing a fast Fourier transform twice and a single interpolation. It is proved that the formula of the rotational transformation mathematically satisfies the Helmholtz equation. Moreover, to verify the formulation and its usefulness in wave optics, it is also demonstrated that the transformation makes it possible to reconstruct an image on arbitrarily tilted planes from a wave field captured experimentally by using digital holography.

Measuring the light scattering and orientation of a spheroidal particle using in-line holography.

PubMed

Seo, Kyung Won; Byeon, Hyeok Jun; Lee, Sang Joon

2014-07-01

The light scattering properties of a horizontally and vertically oriented spheroidal particle under laser illumination are experimentally investigated using digital in-line holography. The reconstructed wave field shows the bright singular points as a result of the condensed beam formed by a transparent spheroidal particle acting as a lens. The in-plane (θ) and out-of-plane (ϕ) rotating angles of an arbitrarily oriented spheroidal particle are measured by using these scattering properties. As a feasibility test, the 3D orientation of a transparent spheroidal particle suspended in a microscale pipe flow is successfully reconstructed by adapting the proposed method.

Acoustical and optical radiation pressure and the development of single beam acoustical tweezers

NASA Astrophysics Data System (ADS)

Thomas, Jean-Louis; Marchiano, Régis; Baresch, Diego

2017-07-01

Studies on radiation pressure in acoustics and optics have enriched one another and have a long common history. Acoustic radiation pressure is used for metrology, levitation, particle trapping and actuation. However, the dexterity and selectivity of single-beam optical tweezers are still to be matched with acoustical devices. Optical tweezers can trap, move and position micron size particles, biological samples or even atoms with subnanometer accuracy in three dimensions. One limitation of optical tweezers is the weak force that can be applied without thermal damage due to optical absorption. Acoustical tweezers overcome this limitation since the radiation pressure scales as the field intensity divided by the speed of propagation of the wave. However, the feasibility of single beam acoustical tweezers was demonstrated only recently. In this paper, we propose a historical review of the strong similarities but also the specificities of acoustical and optical radiation pressures, from the expression of the force to the development of single-beam acoustical tweezers.

Broadband acoustic focusing by Airy-like beams based on acoustic metasurfaces

NASA Astrophysics Data System (ADS)

Chen, Di-Chao; Zhu, Xing-Feng; Wei, Qi; Wu, Da-Jian; Liu, Xiao-Jun

2018-01-01

An acoustic metasurface (AM) composed of space-coiling subunits is proposed to generate acoustic Airy-like beams (ALBs) by manipulating the transmitted acoustic phase. The self-accelerating, self-healing, and non-diffracting features of ALBs are demonstrated using finite element simulations. We further employ two symmetrical AMs to realize two symmetrical ALBs, resulting in highly efficient acoustic focusing. At the working frequency, the focal intensity can reach roughly 20 times that of the incident wave. It is found that the highly efficient acoustic focusing can circumvent obstacles in the propagating path and can be maintained in a broad frequency bandwidth. In addition, simply changing the separation between the two AMs can modulate the focal length of the proposed AM lens. ALBs generated by AMs and the corresponding AM lens may benefit applications in medical ultrasound imaging, biomedical therapy, and particle trapping and manipulation.

Theory and Application of Auger and Photoelectron Diffraction and Holography

NASA Astrophysics Data System (ADS)

Chen, Xiang

This dissertation addresses the theories and applications of three important surface analysis techniques: Auger electron diffraction (AED), x-ray photoelectron diffraction (XPD), and Auger and photoelectron holography. A full multiple-scattering scheme for the calculations of XPD, AED, and Kikuchi electron diffraction pattern from a surface cluster is described. It is used to simulate 64 eV M_{2,3}VV and 913 eV L_3VV AED patterns from Cu(001) surfaces, in order to test assertions in the literature that they are explicable by a classical "blocking" and channeling model. We find that this contention is not valid, and that only a quantum mechanical multiple-scattering calculation is able to simulate these patterns well. The same multiple scattering simulation scheme is also used to investigate the anomalous phenomena of peak shifts off the forward-scattering directions in photo -electron diffraction patterns of Mg KLL (1180 eV) and O 1s (955 eV) from MgO(001) surfaces. These shifts are explained by calculations assuming a short electron mean free path. Similar simulations of XPD from a CoSi_2(111) surface for Co-3p and Si-2p normal emission agree well with experimental diffraction patterns. A filtering process aimed at eliminating the self -interference effect in photoelectron holography is developed. A better reconstructed image from Si-2p XPD from a Si(001) (2 times 1) surface is seen at atomic resolution. A reconstruction algorithm which corrects for the anisotropic emitter waves as well as the anisotropic atomic scattering factors is used for holographic reconstruction from a Co-3p XPD pattern from a CoSi_2 surface. This new algorithm considerably improves the reconstructed image. Finally, a new reconstruction algorithm called "atomic position recovery by iterative optimization of reconstructed intensities" (APRIORI), which takes account of the self-interference terms omitted by the other holographic algorithms, is developed. Tests on a Ni-C-O chain and Si(111

Acoustic integrated extinction.

PubMed

Norris, Andrew N

2015-05-08

The integrated extinction (IE) is defined as the integral of the scattering cross section as a function of wavelength. Sohl et al. (2007 J. Acoust. Soc. Am. 122 , 3206-3210. (doi:10.1121/1.2801546)) derived an IE expression for acoustic scattering that is causal, i.e. the scattered wavefront in the forward direction arrives later than the incident plane wave in the background medium. The IE formula was based on electromagnetic results, for which scattering is causal by default. Here, we derive a formula for the acoustic IE that is valid for causal and non-causal scattering. The general result is expressed as an integral of the time-dependent forward scattering function. The IE reduces to a finite integral for scatterers with zero long-wavelength monopole and dipole amplitudes. Implications for acoustic cloaking are discussed and a new metric is proposed for broadband acoustic transparency.

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

Aspects of holography

NASA Astrophysics Data System (ADS)

Kaplan, Jared Daniel

The principle of holography---that theories of gravity should be described in terms of their boundaries---has been the driving force behind many great strides in quantum gravity, gauge theory, and even in phenomenology. The most concrete example of holographic duality is the AdS/CFT correspondence, which relates quantum gravity in Anti-deSitter space to a Conformal Field Theory in Minkowski space. In this thesis we begin with a chapter on black holes in the AdS/CFT duality, and then move on to the main line of development, where we describe the exciting first steps towards the discovery of a holographic duality for quantum gravity in flat spacetime. A holographic description of flat spacetime would be a theory of the Scattering Matrix, which contains the quantum mechanical amplitudes that determine how incoming states from past infinity scatter into outgoing states at future infinity. We suspect that a holographic duality between a local spacetime description of quantum gravity and a non-local boundary description of the S-Matrix would be a weak coupling-weak coupling duality. We work towards this concrete goal from the bottom up by studying new methods for computing scattering amplitudes. We begin by studying the BCFW Recursion Relations, which are an explicitly non-local, boundary oriented method for computing tree-level scattering amplitudes. We give an elementary derivation of these relations for general theories in any number of dimensions, showing that their existence is a deep feature of field theory. Next we argue that, counter to naive expectations, N = 8 Supergravity may be the simplest quantum field theory. We demonstrate this by explicitly solving its one-loop S-Matrix with techniques that rely on our understanding of tree amplitudes to vastly simplify calculations. Finally, we show that the BCFW recursion relations find their natural home in Twistor Space, where it is possible to formulate classical scattering theory in a beautiful and manifestly

Interacting Multiscale Acoustic Vortices as Coherent Excitations in Dust Acoustic Wave Turbulence

NASA Astrophysics Data System (ADS)

Lin, Po-Cheng; I, Lin

2018-03-01

In this work, using three-dimensional intermittent dust acoustic wave turbulence in a dusty plasma as a platform and multidimensional empirical mode decomposition into different-scale modes in the 2 +1 D spatiotemporal space, we demonstrate the experimental observation of the interacting multiscale acoustic vortices, winding around wormlike amplitude hole filaments coinciding with defect filaments, as the basic coherent excitations for acoustic-type wave turbulence. For different decomposed modes, the self-similar rescaled stretched exponential lifetime histograms of amplitude hole filaments, and the self-similar power spectra of dust density fluctuations, indicate that similar dynamical rules are followed over a wide range of scales. In addition to the intermode acoustic vortex pair generation, propagation, or annihilation, the intra- and intermode interactions of acoustic vortices with the same or opposite helicity, their entanglement and synchronization, are found to be the key dynamical processes in acoustic wave turbulence, akin to the interacting multiscale vortices around wormlike cores observed in hydrodynamic turbulence.

Acoustic Test Results of Melamine Foam with Application to Payload Fairing Acoustic Attenuation Systems

NASA Technical Reports Server (NTRS)

Hughes, William O.; McNelis, Anne M.

2014-01-01

A spacecraft at launch is subjected to a harsh acoustic and vibration environment resulting from the passage of acoustic energy, created during the liftoff of a launch vehicle, through the vehicle's payload fairing. In order to ensure the mission success of the spacecraft it is often necessary to reduce the resulting internal acoustic sound pressure levels through the usage of acoustic attenuation systems. Melamine foam, lining the interior walls of the payload fairing, is often utilized as the main component of such a system. In order to better understand the acoustic properties of melamine foam, with the goal of developing improved acoustic attenuation systems, NASA has recently performed panel level testing on numerous configurations of melamine foam acoustic treatments at the Riverbank Acoustical Laboratory. Parameters assessed included the foam's thickness and density, as well as the effects of a top outer cover sheet material and mass barriers embedded within the foam. This testing followed the ASTM C423 standard for absorption and the ASTM E90 standard for transmission loss. The acoustic test data obtained and subsequent conclusions are the subjects of this paper.

Cevimeline-induced monophasic salivation from the mouse submandibular gland: decreased Na+ content in saliva results from specific and early activation of Na+/H+ exchange.

PubMed

Kondo, Yusuke; Nakamoto, Tetsuji; Mukaibo, Taro; Kidokoro, Manami; Masaki, Chihiro; Hosokawa, Ryuji

2011-04-01

Cevimeline and pilocarpine are muscarinic agonists used clinically to treat dry mouth. In this study, we explored fluid secretion from mouse submandibular glands to determine the mechanism of cevimeline, pilocarpine, and an experimentally used agent carbachol. Cevimeline evoked almost the same amount of secretion at concentrations from 30 μM to 1 mM. Pilocarpine also induced secretion at a concentration as low as 1 μM and was the most powerful secretagogue at 10 μM. Secretion was induced by carbachol at 0.1 μM, with maximum secretion at 1.0 μM. Cevimeline induced monophasic secretion at all concentrations tested, whereas higher concentrations of pilocarpine and carbachol induced secretion with variable kinetics, i.e., an initial transient high flow rate, followed by decreased secretion after 2 to 3 min. In the presence of an epithelial Na(+) channel blocker, amiloride, neither carbachol nor pilocarpine affected the Na(+) level of secreted saliva; however, it significantly increased the Na(+) content of cevimeline-induced saliva. The intracellular Ca(2+) response of acinar cells was almost identical among all three agents, although recovery after drug removal was slower for cevimeline and pilocarpine. A profound decrease in intracellular pH was observed during pilocarpine and carbachol treatment, whereas intracellular acidification induced by cevimeline was only seen in the presence of a Na(+)/H(+) exchange inhibitor. When external HCO(3)(-) was removed, cevimeline-induced saliva significantly decreased. These findings suggest that cevimeline specifically activates Na(+)/H(+) exchange and may promote Na(+) reabsorption by stabilizing epithelial sodium channel activity.

Acoustic Suppression Systems and Related Methods

NASA Technical Reports Server (NTRS)

Kolaini, Ali R. (Inventor); Kern, Dennis L. (Inventor)

2013-01-01

An acoustic suppression system for absorbing and/or scattering acoustic energy comprising a plurality of acoustic targets in a containment is described, the acoustic targets configured to have resonance frequencies allowing the targets to be excited by incoming acoustic waves, the resonance frequencies being adjustable to suppress acoustic energy in a set frequency range. Methods for fabricating and implementing the acoustic suppression system are also provided.

Introducing passive acoustic filter in acoustic based condition monitoring: Motor bike piston-bore fault identification

NASA Astrophysics Data System (ADS)

Jena, D. P.; Panigrahi, S. N.

2016-03-01

Requirement of designing a sophisticated digital band-pass filter in acoustic based condition monitoring has been eliminated by introducing a passive acoustic filter in the present work. So far, no one has attempted to explore the possibility of implementing passive acoustic filters in acoustic based condition monitoring as a pre-conditioner. In order to enhance the acoustic based condition monitoring, a passive acoustic band-pass filter has been designed and deployed. Towards achieving an efficient band-pass acoustic filter, a generalized design methodology has been proposed to design and optimize the desired acoustic filter using multiple filter components in series. An appropriate objective function has been identified for genetic algorithm (GA) based optimization technique with multiple design constraints. In addition, the sturdiness of the proposed method has been demonstrated in designing a band-pass filter by using an n-branch Quincke tube, a high pass filter and multiple Helmholtz resonators. The performance of the designed acoustic band-pass filter has been shown by investigating the piston-bore defect of a motor-bike using engine noise signature. On the introducing a passive acoustic filter in acoustic based condition monitoring reveals the enhancement in machine learning based fault identification practice significantly. This is also a first attempt of its own kind.

Linear response of entanglement entropy from holography

NASA Astrophysics Data System (ADS)

Lokhande, Sagar F.; Oling, Gerben W. J.; Pedraza, Juan F.

2017-10-01

For time-independent excited states in conformal field theories, the entanglement entropy of small subsystems satisfies a `first law'-like relation, in which the change in entanglement is proportional to the energy within the entangling region. Such a law holds for time-dependent scenarios as long as the state is perturbatively close to the vacuum, but is not expected otherwise. In this paper we use holography to investigate the spread of entanglement entropy for unitary evolutions of special physical interest, the so-called global quenches. We model these using AdS-Vaidya geometries. We find that the first law of entanglement is replaced by a linear response relation, in which the energy density takes the role of the source and is integrated against a time-dependent kernel with compact support. For adiabatic quenches the standard first law is recovered, while for rapid quenches the linear response includes an extra term that encodes the process of thermalization. This extra term has properties that resemble a time-dependent `relative entropy'. We propose that this quantity serves as a useful order parameter to characterize far-from-equilibrium excited states. We illustrate our findings with concrete examples, including generic power-law and periodically driven quenches.

New Acoustic Arena Qualified at NASA Glenn's Aero-Acoustic Propulsion Laboratory

NASA Technical Reports Server (NTRS)

Wnuk, Stephen P.

2004-01-01

A new acoustic arena has been qualified in the Aero-Acoustic Propulsion Laboratory (AAPL) at the NASA Glenn Research Center. This arena is outfitted specifically for conducting fan noise research with the Advanced Noise Control Fan (ANCF) test rig. It features moveable walls with large acoustic wedges (2 by 2 by 1 ft) that create an acoustic environment usable at frequencies as low as 250 Hz. The arena currently uses two dedicated microphone arrays to acquire fan inlet and exhaust far-field acoustic data. It was used successfully in fiscal year 2003 to complete three ANCF tests. It also allowed Glenn to improve the operational efficiency of the four test rigs at AAPL and provided greater flexibility to schedule testing. There were a number of technical challenges to overcome in bringing the new arena to fruition. The foremost challenge was conflicting acoustic requirements of four different rigs. It was simply impossible to construct a static arena anywhere in the facility without intolerably compromising the acoustic test environment of at least one of the test rigs. This problem was overcome by making the wall sections of the new arena movable. Thus, the arena can be reconfigured to meet the operational requirements of any particular rig under test. Other design challenges that were encountered and overcome included structural loads of the large wedges, personnel access requirements, equipment maintenance requirements, and typical time and budget constraints. The new acoustic arena improves operations at the AAPL facility in several significant ways. First, it improves productivity by allowing multiple rigs to operate simultaneously. Second, it improves research data quality by providing a unique test area within the facility that is optimal for conducting fan noise research. Lastly, it reduces labor and equipment costs by eliminating the periodic need to transport the ANCF into and out of the primary AAPL acoustic arena. The investment to design, fabricate, and

Acoustic cooling engine

DOEpatents

Hofler, Thomas J.; Wheatley, John C.; Swift, Gregory W.; Migliori, Albert

1988-01-01

An acoustic cooling engine with improved thermal performance and reduced internal losses comprises a compressible fluid contained in a resonant pressure vessel. The fluid has a substantial thermal expansion coefficient and is capable of supporting an acoustic standing wave. A thermodynamic element has first and second ends and is located in the resonant pressure vessel in thermal communication with the fluid. The thermal response of the thermodynamic element to the acoustic standing wave pumps heat from the second end to the first end. The thermodynamic element permits substantial flow of the fluid through the thermodynamic element. An acoustic driver cyclically drives the fluid with an acoustic standing wave. The driver is at a location of maximum acoustic impedance in the resonant pressure vessel and proximate the first end of the thermodynamic element. A hot heat exchanger is adjacent to and in thermal communication with the first end of the thermodynamic element. The hot heat exchanger conducts heat from the first end to portions of the resonant pressure vessel proximate the hot heat exchanger. The hot heat exchanger permits substantial flow of the fluid through the hot heat exchanger. The resonant pressure vessel can include a housing less than one quarter wavelength in length coupled to a reservoir. The housing can include a reduced diameter portion communicating with the reservoir. The frequency of the acoustic driver can be continuously controlled so as to maintain resonance.

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.

Contour mode resonators with acoustic reflectors

DOEpatents

Olsson, Roy H [Albuquerque, NM; Fleming, James G [Albuquerque, NM; Tuck, Melanie R [Albuquerque, NM

2008-06-10

A microelectromechanical (MEM) resonator is disclosed which has a linear or ring-shaped acoustic resonator suspended above a substrate by an acoustic reflector. The acoustic resonator can be formed with a piezoelectric material (e.g. aluminum nitride, zinc oxide or PZT), or using an electrostatically-actuated material. The acoustic reflector (also termed an acoustic mirror) uses alternating sections of a relatively low acoustic impedance Z.sub.L material and a relatively high acoustic impedance Z.sub.H material to isolate the acoustic resonator from the substrate. The MEM resonator, which can be formed on a silicon substrate with conventional CMOS circuitry, has applications for forming oscillators, rf filters, and acoustic sensors.

Acoustic Remote Sensing

NASA Astrophysics Data System (ADS)

Dowling, David R.; Sabra, Karim G.

2015-01-01

Acoustic waves carry information about their source and collect information about their environment as they propagate. This article reviews how these information-carrying and -collecting features of acoustic waves that travel through fluids can be exploited for remote sensing. In nearly all cases, modern acoustic remote sensing involves array-recorded sounds and array signal processing to recover multidimensional results. The application realm for acoustic remote sensing spans an impressive range of signal frequencies (10-2 to 107 Hz) and distances (10-2 to 107 m) and involves biomedical ultrasound imaging, nondestructive evaluation, oil and gas exploration, military systems, and Nuclear Test Ban Treaty monitoring. In the past two decades, approaches have been developed to robustly localize remote sources; remove noise and multipath distortion from recorded signals; and determine the acoustic characteristics of the environment through which the sound waves have traveled, even when the recorded sounds originate from uncooperative sources or are merely ambient noise.

The acoustic vector sensor: a versatile battlefield acoustics sensor

NASA Astrophysics Data System (ADS)

de Bree, Hans-Elias; Wind, Jelmer W.

2011-06-01

The invention of the Microflown sensor has made it possible to measure acoustic particle velocity directly. An acoustic vector sensor (AVS) measures the particle velocity in three directions (the source direction) and the pressure. The sensor is a uniquely versatile battlefield sensor because its size is a few millimeters and it is sensitive to sound from 10Hz to 10kHz. This article shows field tests results of acoustic vector sensors, measuring rifles, heavy artillery, fixed wing aircraft and helicopters. Experimental data shows that the sensor is suitable as a ground sensor, mounted on a vehicle and on a UAV.

An exogenous hydrogen sulphide donor, NaHS, inhibits the apoptosis signaling pathway to exert cardio-protective effects in a rat hemorrhagic shock model.

PubMed

Xu, Yanjie; Dai, Xiongwei; Zhu, Danxia; Xu, Xiaoli; Gao, Cao; Wu, Changping

2015-01-01

Hydrogen sulfide (H2S) has been reported to be interwined in multiple systems, specifically in the cardiovascular system. However, the mechanisms underlying remain controversial. In the present study, we assessed the cardio-protective effects of H2S in the rat hemorrhagic shock model. Hemorrhagic shock was induced in adult male Sprague-Dawley rats by drawing blood from the femoral artery to maintain the mean arterial pressure at 35-40 mmHg for 1.5 h. The rats were assigned to four groups and the H2S donor, NaHS (28 μmol/kg, i.p.), was injected before the resuscitation in certain groups. After resuscitation the animals were observed and then killed to harvest the hearts. The morphological investigation and ultrastructural analyses were done and apoptotic cells were detected. The levels of relevant proteins were examined using Western blotting and immunohistochemical analyses. Resuscitated hemorrhagic shock induced heart injury and significantly increased the levels of serum myocardial enzymes, creatine kinase (CK) and lactate dehydrogenase (LDH) levels. Furthermore, it caused marked increase of apoptotic cells in heart tissue. Moreover, the expression of death receptor Fas and Fas-ligand, as well as the expression of apoptosis-relevant proteins active-caspase 3 and active-caspase 8 were markedly increased. Administration of NaHS significantly ameliorated hemorrhagic shock caused hemodynamic deterioration, decreased myocardial enzymes elevation, protected myocardial ultrastructure, and inhibited the expression of apoptosis-relevant proteins. It suggested that H2S might exert its cardio-protective roles via both the extrinsic Fas/FasL/caspase-8/caspase-3 pathway and the intrinsic mitochondria-involved pathways.

Image Size Scalable Full-parallax Coloured Three-dimensional Video by Electronic Holography

NASA Astrophysics Data System (ADS)

Sasaki, Hisayuki; Yamamoto, Kenji; Ichihashi, Yasuyuki; Senoh, Takanori

2014-02-01

In electronic holography, various methods have been considered for using multiple spatial light modulators (SLM) to increase the image size. In a previous work, we used a monochrome light source for a method that located an optical system containing lens arrays and other components in front of multiple SLMs. This paper proposes a colourization technique for that system based on time division multiplexing using laser light sources of three colours (red, green, and blue). The experimental device we constructed was able to perform video playback (20 fps) in colour of full parallax holographic three-dimensional (3D) images with an image size of 63 mm and a viewing-zone angle of 5.6 degrees without losing any part of the 3D image.

Acoustic manipulation of oscillating spherical bodies: Emergence of axial negative acoustic radiation force

NASA Astrophysics Data System (ADS)

Rajabi, Majid; Mojahed, Alireza

2016-11-01

In this paper, emergence of negative axial acoustic radiation force on a rigid oscillating spherical body is investigated for acoustic manipulation purposes. The problem of plane acoustic wave scattering from an oscillating spherical body submerged in an ideal acoustic fluid medium is solved. For the case of oscillating direction collinear with the wave propagation wave number vector (desired path), it has been shown that the acoustic radiation force, as a result of nonlinear acoustic wave interaction with bodies can be expressed as a linear function of incident wave field and the oscillation properties of the oscillator (i.e., amplitude and phase of oscillation). The negative (i.e., pulling effects) and positive (i.e., pushing effects) radiation force situations are divided in oscillation complex plane with a specific frequency-dependant straight line. This characteristic line defines the radiation force cancellation state. In order to investigate the stability of the mentioned manipulation strategy, the case of misaligned oscillation of sphere with the wave propagation direction is studied. The proposed methodology may suggest a novel concept of single-beam acoustic handling techniques based on smart carriers.

Hybrid Electrostatic/Acoustic Levitator

NASA Technical Reports Server (NTRS)

Rhim, Won K.; Trinh, Eugene H.; Chung, Sang K.; Elleman, Daniel D.

1987-01-01

Because electrostatic and acoustic forces independent of each other, hybrid levitator especially suitable for studies of drop dynamics. Like all-acoustic or all-electrostatic systems, also used in studies of containerless material processing. Vertical levitating force applied to sample by upper and lower electrodes. Torques or vibrational forces in horizontal plane applied by acoustic transducers. Electrically charged water drop about 4 mm in diameter levitated electrostatically and rotated acoustically until it assumed dumbell shape and broke apart.

Education in acoustics in Argentina

NASA Astrophysics Data System (ADS)

Miyara, Federico

2002-11-01

Over the last decades, education in acoustics (EA) in Argentina has experienced ups and downs due to economic and political issues interfering with long term projects. Unlike other countries, like Chile, where EA has reached maturity in spite of the acoustical industry having shown little development, Argentina has several well-established manufacturers of acoustic materials and equipment but no specific career with a major in acoustics. At the university level, acoustics is taught as a complementary--often elective--course for careers such as architecture, communication engineering, or music. In spite of this there are several research centers with programs covering environmental and community noise, effects of noise on man, acoustic signal processing, musical acoustics and acoustic emission, and several national and international meetings are held each year in which results are communicated and discussed. Several books on a variety of topics such as sound system, architectural acoustics, and noise control have been published as well. Another chapter in EA is technical and vocational education, ranging between secondary and postsecondary levels, with technical training on sound system operation or design. Over the last years there have been several attempts to implement master degrees in acoustics or audio engineering, with little or no success.

The North Pacific Acoustic Laboratory deep-water acoustic propagation experiments in the Philippine Sea.

PubMed

Worcester, Peter F; Dzieciuch, Matthew A; Mercer, James A; Andrew, Rex K; Dushaw, Brian D; Baggeroer, Arthur B; Heaney, Kevin D; D'Spain, Gerald L; Colosi, John A; Stephen, Ralph A; Kemp, John N; Howe, Bruce M; Van Uffelen, Lora J; Wage, Kathleen E

2013-10-01

A series of experiments conducted in the Philippine Sea during 2009-2011 investigated deep-water acoustic propagation and ambient noise in this oceanographically and geologically complex region: (i) the 2009 North Pacific Acoustic Laboratory (NPAL) Pilot Study/Engineering Test, (ii) the 2010-2011 NPAL Philippine Sea Experiment, and (iii) the Ocean Bottom Seismometer Augmentation of the 2010-2011 NPAL Philippine Sea Experiment. The experimental goals included (a) understanding the impacts of fronts, eddies, and internal tides on acoustic propagation, (b) determining whether acoustic methods, together with other measurements and ocean modeling, can yield estimates of the time-evolving ocean state useful for making improved acoustic predictions, (c) improving our understanding of the physics of scattering by internal waves and spice, (d) characterizing the depth dependence and temporal variability of ambient noise, and (e) understanding the relationship between the acoustic field in the water column and the seismic field in the seafloor. In these experiments, moored and ship-suspended low-frequency acoustic sources transmitted to a newly developed distributed vertical line array receiver capable of spanning the water column in the deep ocean. The acoustic transmissions and ambient noise were also recorded by a towed hydrophone array, by acoustic Seagliders, and by ocean bottom seismometers.

Review of Progress in Acoustic Levitation

NASA Astrophysics Data System (ADS)

Andrade, Marco A. B.; Pérez, Nicolás; Adamowski, Julio C.

2018-04-01

Acoustic levitation uses acoustic radiation forces to counteract gravity and suspend objects in mid-air. Although acoustic levitation was first demonstrated almost a century ago, for a long time, it was limited to objects much smaller than the acoustic wavelength levitating at fixed positions in space. Recent advances in acoustic levitation now allow not only suspending but also rotating and translating objects in three dimensions. Acoustic levitation is also no longer restricted to small objects and can now be employed to levitate objects larger than the acoustic wavelength. This article reviews the progress of acoustic levitation, focusing on the working mechanism of different types of acoustic levitation devices developed to date. We start with a brief review of the theory. Then, we review the acoustic levitation methods to suspend objects at fixed positions, followed by the techniques that allow the manipulation of objects. Finally, we present a brief summary and offer some future perspectives for acoustic levitation.

Nondestructive Testing Information Analysis Center, 1979.

DTIC Science & Technology

1980-09-01

transmission and reflectometry Ultrasonic imaging Spectrum analysis Acoustic emission * LIQUID PENETRANT TESTING Dye penetrants Fluorescent penetrants...OPTICAL TESTING Visual testing Optical reflectometry and transmission Holography * THERMAL TESTING Infrared radiometry The rmography 13 The present...on our surveillance effectiveness, we also scan Current Contents, NASA /SCAN, and the monthly Engineering Index and Science Abstracts. New books

A study on the theoretical and practical accuracy of conoscopic holography-based surface measurements: toward image registration in minimally invasive surgery†

PubMed Central

Burgner, J.; Simpson, A. L.; Fitzpatrick, J. M.; Lathrop, R. A.; Herrell, S. D.; Miga, M. I.; Webster, R. J.

2013-01-01

Background Registered medical images can assist with surgical navigation and enable image-guided therapy delivery. In soft tissues, surface-based registration is often used and can be facilitated by laser surface scanning. Tracked conoscopic holography (which provides distance measurements) has been recently proposed as a minimally invasive way to obtain surface scans. Moving this technique from concept to clinical use requires a rigorous accuracy evaluation, which is the purpose of our paper. Methods We adapt recent non-homogeneous and anisotropic point-based registration results to provide a theoretical framework for predicting the accuracy of tracked distance measurement systems. Experiments are conducted a complex objects of defined geometry, an anthropomorphic kidney phantom and a human cadaver kidney. Results Experiments agree with model predictions, producing point RMS errors consistently < 1 mm, surface-based registration with mean closest point error < 1 mm in the phantom and a RMS target registration error of 0.8 mm in the human cadaver kidney. Conclusions Tracked conoscopic holography is clinically viable; it enables minimally invasive surface scan accuracy comparable to current clinical methods that require open surgery. PMID:22761086

Measuring acoustic habitats

PubMed Central

Merchant, Nathan D; Fristrup, Kurt M; Johnson, Mark P; Tyack, Peter L; Witt, Matthew J; Blondel, Philippe; Parks, Susan E

2015-01-01

1. Many organisms depend on sound for communication, predator/prey detection and navigation. The acoustic environment can therefore play an important role in ecosystem dynamics and evolution. A growing number of studies are documenting acoustic habitats and their influences on animal development, behaviour, physiology and spatial ecology, which has led to increasing demand for passive acoustic monitoring (PAM) expertise in the life sciences. However, as yet, there has been no synthesis of data processing methods for acoustic habitat monitoring, which presents an unnecessary obstacle to would-be PAM analysts. 2. Here, we review the signal processing techniques needed to produce calibrated measurements of terrestrial and aquatic acoustic habitats. We include a supplemental tutorial and template computer codes in matlab and r, which give detailed guidance on how to produce calibrated spectrograms and statistical analyses of sound levels. Key metrics and terminology for the characterisation of biotic, abiotic and anthropogenic sound are covered, and their application to relevant monitoring scenarios is illustrated through example data sets. To inform study design and hardware selection, we also include an up-to-date overview of terrestrial and aquatic PAM instruments. 3. Monitoring of acoustic habitats at large spatiotemporal scales is becoming possible through recent advances in PAM technology. This will enhance our understanding of the role of sound in the spatial ecology of acoustically sensitive species and inform spatial planning to mitigate the rising influence of anthropogenic noise in these ecosystems. As we demonstrate in this work, progress in these areas will depend upon the application of consistent and appropriate PAM methodologies. PMID:25954500

Measuring acoustic habitats.

PubMed

Merchant, Nathan D; Fristrup, Kurt M; Johnson, Mark P; Tyack, Peter L; Witt, Matthew J; Blondel, Philippe; Parks, Susan E

2015-03-01

1. Many organisms depend on sound for communication, predator/prey detection and navigation. The acoustic environment can therefore play an important role in ecosystem dynamics and evolution. A growing number of studies are documenting acoustic habitats and their influences on animal development, behaviour, physiology and spatial ecology, which has led to increasing demand for passive acoustic monitoring (PAM) expertise in the life sciences. However, as yet, there has been no synthesis of data processing methods for acoustic habitat monitoring, which presents an unnecessary obstacle to would-be PAM analysts. 2. Here, we review the signal processing techniques needed to produce calibrated measurements of terrestrial and aquatic acoustic habitats. We include a supplemental tutorial and template computer codes in matlab and r, which give detailed guidance on how to produce calibrated spectrograms and statistical analyses of sound levels. Key metrics and terminology for the characterisation of biotic, abiotic and anthropogenic sound are covered, and their application to relevant monitoring scenarios is illustrated through example data sets. To inform study design and hardware selection, we also include an up-to-date overview of terrestrial and aquatic PAM instruments. 3. Monitoring of acoustic habitats at large spatiotemporal scales is becoming possible through recent advances in PAM technology. This will enhance our understanding of the role of sound in the spatial ecology of acoustically sensitive species and inform spatial planning to mitigate the rising influence of anthropogenic noise in these ecosystems. As we demonstrate in this work, progress in these areas will depend upon the application of consistent and appropriate PAM methodologies.

Interaction of surface plasmon polaritons and acoustic waves inside an acoustic cavity.

PubMed

Khokhlov, Nikolai; Knyazev, Grigoriy; Glavin, Boris; Shtykov, Yakov; Romanov, Oleg; Belotelov, Vladimir

2017-09-15

In this Letter, we introduce an approach for manipulation of active plasmon polaritons via acoustic waves at sub-terahertz frequency range. The acoustic structures considered are designed as phononic Fabry-Perot microresonators where mirrors are presented with an acoustic superlattice and the structure's surface, and a plasmonic grating is placed on top of the acoustic cavity so formed. It provides phonon localization in the vicinity of the plasmonic grating at frequencies within the phononic stop band enhancing phonon-light interaction. We consider phonon excitation by shining a femtosecond laser pulse on the plasmonic grating. Appropriate theoretical model was used to describe the acoustic process caused by the pump laser pulse in the GaAs/AlAs-based acoustic cavity with a gold grating on top. Strongest modulation is achieved upon excitation of propagating surface plasmon polaritons and hybridization of propagating and localized plasmons. The relative changes in the optical reflectivity of the structure are more than an order of magnitude higher than for the structure without the plasmonic film.

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. © 2016 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

High temperature acoustic and hybrid microwave/acoustic levitators for materials processing

NASA Technical Reports Server (NTRS)

Barmatz, Martin

1990-01-01

The physical acoustics group at the Jet Propulsion Laboratory developed a single mode acoustic levitator technique for advanced containerless materials processing. The technique was successfully demonstrated in ground based studies to temperatures of about 1000 C in a uniform temperature furnace environment and to temperatures of about 1500 C using laser beams to locally heat the sample. Researchers are evaluating microwaves as a more efficient means than lasers for locally heating a positioned sample. Recent tests of a prototype single mode hybrid microwave/acoustic levitator successfully demonstrated the feasibility of using microwave power as a heating source. The potential advantages of combining acoustic positioning forces and microwave heating for containerless processing investigations are presented in outline form.

Resurgence and hydrodynamic attractors in Gauss-Bonnet holography

NASA Astrophysics Data System (ADS)

Casalderrey-Solana, Jorge; Gushterov, Nikola I.; Meiring, Ben

2018-04-01

We study the convergence of the hydrodynamic series in the gravity dual of Gauss-Bonnet gravity in five dimensions with negative cosmological constant via holography. By imposing boost invariance symmetry, we find a solution to the Gauss-Bonnet equation of motion in inverse powers of the proper time, from which we can extract high order corrections to Bjorken flow for different values of the Gauss-Bonnet parameter λGB. As in all other known examples the gradient expansion is, at most, an asymptotic series which can be understood through applying the techniques of Borel-Padé summation. As expected from the behaviour of the quasi-normal modes in the theory, we observe that the singularities in the Borel plane of this series show qualitative features that interpolate between the infinitely strong coupling limit of N=4 Super Yang Mills theory and the expectation from kinetic theory. We further perform the Borel resummation to constrain the behaviour of hydrodynamic attractors beyond leading order in the hydrodynamic expansion. We find that for all values of λGB considered, the convergence of different initial conditions to the resummation and its hydrodynamization occur at large and comparable values of the pressure anisotropy.

Super-resolved Mirau digital holography by structured illumination

NASA Astrophysics Data System (ADS)

Ganjkhani, Yasaman; Charsooghi, Mohammad A.; Akhlaghi, Ehsan A.; Moradi, Ali-Reza

2017-12-01

In this paper, we apply structured illumination toward super-resolved 3D imaging in a common-path digital holography arrangement. Digital holographic microscopy (DHM) provides non-invasive 3D images of transparent samples as well as 3D profiles of reflective surfaces. A compact and vibration-immune arrangement for DHM may be obtained through the use of a Mirau microscope objective. However, high-magnification Mirau objectives have a low working distance and are expensive. Low-magnification ones, on the other hand, suffer from low lateral resolution. Structured illumination has been widely used for resolution improvement of intensity images, but the technique can also be readily applied to DHM. We apply structured illumination to Mirau DHM by implementing successive sinusoidal gratings with different orientations onto a spatial light modulator (SLM) and forming its image on the specimen. Moreover, we show that, instead of different orientations of 1D gratings, alternative single 2D gratings, e.g. checkerboard or hexagonal patterns, can provide resolution enhancement in multiple directions. Our results show a 35% improvement in the resolution power of the DHM. The presented arrangement has the potential to serve as a table-top device for high resolution holographic microscopy.

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.

Research on Acoustical Scattering, Diffraction Catastrophes, Optics of Bubbles, Photoacoustics, and Acoustical Phase Conjugation.

DTIC Science & Technology

1987-09-15

optical levitation of bubbles; D. Acoustical and optical diffraction catastrophes (theory and optical simulation of transverse cusps, experiments with...35 C. Optical Levitation of Bubbles in Water by the Radiation Pressure of a Laser Beam: An Acoustically Quiet Levitator ...radiation pressure of a laser beam: an acoustically quiet levitator ," J. Acoust . Soc. Am. (submitted July 1987). C. Books (and sections thereof) Published

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.

Design of a digital holography system for PFC erosion measurements on Proto-MPEX

DOE Office of Scientific and Technical Information (OSTI.GOV)

ThomasJr., C. E.; Biewer, Theodore M; Baylor, Larry R

2016-01-01

A project has been started at ORNL to develop a dual-wavelength digital holography system for plasma facing component (PFC) erosion measurements on Proto-MPEX. Such a system will allow in-situ real-time measurements of component erosion. Initially the system will be developed with one laser, and first experimental laboratory measurements will be made with the single laser system. In the second year of development a second CO2 laser will be added and measurements with the dual wavelength system will begin. Adding the second wavelength allows measurements at a much longer synthetic wavelength equal to the average of the two wavelengths times themore » average divided by the difference of the two wavelengths.« less

Evaluating unsupervised methods to size and classify suspended particles using digital in-line holography

USGS Publications Warehouse

Davies, Emlyn J.; Buscombe, Daniel D.; Graham, George W.; Nimmo-Smith, W. Alex M.

2015-01-01

Substantial information can be gained from digital in-line holography of marine particles, eliminating depth-of-field and focusing errors associated with standard lens-based imaging methods. However, for the technique to reach its full potential in oceanographic research, fully unsupervised (automated) methods are required for focusing, segmentation, sizing and classification of particles. These computational challenges are the subject of this paper, in which we draw upon data collected using a variety of holographic systems developed at Plymouth University, UK, from a significant range of particle types, sizes and shapes. A new method for noise reduction in reconstructed planes is found to be successful in aiding particle segmentation and sizing. The performance of an automated routine for deriving particle characteristics (and subsequent size distributions) is evaluated against equivalent size metrics obtained by a trained operative measuring grain axes on screen. The unsupervised method is found to be reliable, despite some errors resulting from over-segmentation of particles. A simple unsupervised particle classification system is developed, and is capable of successfully differentiating sand grains, bubbles and diatoms from within the surf-zone. Avoiding miscounting bubbles and biological particles as sand grains enables more accurate estimates of sand concentrations, and is especially important in deployments of particle monitoring instrumentation in aerated water. Perhaps the greatest potential for further development in the computational aspects of particle holography is in the area of unsupervised particle classification. The simple method proposed here provides a foundation upon which further development could lead to reliable identification of more complex particle populations, such as those containing phytoplankton, zooplankton, flocculated cohesive sediments and oil droplets.

Cave acoustics in prehistory: Exploring the association of Palaeolithic visual motifs and acoustic response.

PubMed

Fazenda, Bruno; Scarre, Chris; Till, Rupert; Pasalodos, Raquel Jiménez; Guerra, Manuel Rojo; Tejedor, Cristina; Peredo, Roberto Ontañón; Watson, Aaron; Wyatt, Simon; Benito, Carlos García; Drinkall, Helen; Foulds, Frederick

2017-09-01

During the 1980 s, acoustic studies of Upper Palaeolithic imagery in French caves-using the technology then available-suggested a relationship between acoustic response and the location of visual motifs. This paper presents an investigation, using modern acoustic measurement techniques, into such relationships within the caves of La Garma, Las Chimeneas, La Pasiega, El Castillo, and Tito Bustillo in Northern Spain. It addresses methodological issues concerning acoustic measurement at enclosed archaeological sites and outlines a general framework for extraction of acoustic features that may be used to support archaeological hypotheses. The analysis explores possible associations between the position of visual motifs (which may be up to 40 000 yrs old) and localized acoustic responses. Results suggest that motifs, in general, and lines and dots, in particular, are statistically more likely to be found in places where reverberation is moderate and where the low frequency acoustic response has evidence of resonant behavior. The work presented suggests that an association of the location of Palaeolithic motifs with acoustic features is a statistically weak but tenable hypothesis, and that an appreciation of sound could have influenced behavior among Palaeolithic societies of this region.

An Expendable Source for Measuring Shallow Water Acoustic Propagation and Geo-Acoustic Bottom Properties

DTIC Science & Technology

2015-09-30

Propagation and Geo -Acoustic Bottom Properties Harry A DeFerrari RSMAS – University of Miami 4600 Rickenbacker Causeway Miami FL. 33149...limited information about the ocean acoustic environment and the geo -acoustic properties of the bottom. The objective here is to measure the pulse...models and estimate the geo -acoustic properties of the bottom by inversion. APPROACH M-sequences have long been the workhorse of basic research

Digital holography of intracellular dynamics to probe tissue physiology.

PubMed

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 to 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) and 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.

Protective effects of vitamin B6 alone and in combination with L-cysteine and NaHS on ethanol and indomethacin-induced gastric lesions in mice.

PubMed

Mard, Seyyed Ali; Ashabi, Ardeshir; Badavi, Mohammad; Dianat, Mahin

2015-03-01

This study was undertaken to investigate the protective effects of vitamin B6, cofactor for cystathionine-γ lyase and cystathionine-β synthase (producers of H2S), alone and in combination with L-cysteine, H2S precursor, on indomethacin-, and ethanol-induced gastric lesions in male NMRI mice. Fasted male NMRI mice were randomly assigned into 12 groups (7 in each). The gastroprotective activity of vitamin B6 alone and in combination with L-cysteine and sodium hydrosulfate (NaHS) was evaluated against ethanol-, and indomethacin-induced gastric lesions. The animals were received vehicle, vitamin B6, L-cysteine, L-cysteine+vitamin B6, NaHS or NaHS+B6 before the induction of gastric lesions by ethanol (50%, 0.5 ml/25 g of body weight, orally) or indomethacin (40 mg/kg, orally). One and five hours after the administration of ethanol and indomethacin, respectively, the animals were sacrificed using anesthetics. The stomachs were removed, rinsed with normal saline and assessed for gastric wall mucus changes. Pretreatment with L-cysteine, sodium hydrosulfate, and vitamin B6 significantly decreased the total area of gastric lesions (P<0.01). The mucus production in L-cysteine-, sodium hydrosulfate-, and vitamin B6-treated animals were significantly higher than in control rats P<0.05). The gastroprotective activity of L-cysteine and sodium hydrosulfate in combination with vitamin B6 were higher than when administered alone (P<0.05). The result of this survey showed that the protective activity of L-cysteine and sodium hydrosulfate enhances in the presence of vitamin B6.

Observation of self-excited acoustic vortices in defect-mediated dust acoustic wave turbulence.

PubMed

Tsai, Ya-Yi; I, Lin

2014-07-01

Using the self-excited dust acoustic wave as a platform, we demonstrate experimental observation of self-excited fluctuating acoustic vortex pairs with ± 1 topological charges through spontaneous waveform undulation in defect-mediated turbulence for three-dimensional traveling nonlinear longitudinal waves. The acoustic vortex pair has helical waveforms with opposite chirality around the low-density hole filament pair in xyt space (the xy plane is the plane normal to the wave propagation direction). It is generated through ruptures of sequential crest surfaces and reconnections with their trailing ruptured crest surfaces. The initial rupture is originated from the amplitude reduction induced by the formation of the kinked wave crest strip with strong stretching through the undulation instability. Increasing rupture causes the separation of the acoustic vortex pair after generation. A similar reverse process is followed for the acoustic vortex annihilating with the opposite-charged acoustic vortex from the same or another pair generation.

Anisotropy in Gravity and Holography

NASA Astrophysics Data System (ADS)

Melby-Thompson, Charles Milton

In this thesis, we examine the dynamical structure of Hořava-Lifshitz gravity, and investigate its relationship with holography for anisotropic systems. Hořava-Lifshitz gravity refers to a broad class of gravitational models that incorporate anisotropy at a fundamental level. The idea behind Hořava-Lifshitz gravity is to utilize ideas from the theory of dynamical critical phenomena into gravity to produce a theory of dynamical spacetime that is power-counting renormalizable, and is thus a candidate renormalizable quantum field theory of gravity. One of the most distinctive features of Hořava-Lifshitz gravity is that its group of symmetries consists not of the diffeomorphisms of spacetime, but instead of the group of diffeomorphisms that preserve a given foliation by spatial slices. As a result of having a smaller group of symmetries, HL gravity naturally has one more propagating degree of freedom than general relativity. The extra mode presents two possible difficulties with the theory, one relating to consistency, and the second to its viability as a phenomenological model. (1) It may destabilize the theory. (2) Phenomenologically, there are severe constraints on the existence of an extra propagating graviton polarization, as well as strong experimental constraints on the value of a parameter appearing in the dispersion relation of the extra mode. In the first part of this dissertation we show that the extra mode can be eliminated by introducing a new local symmetry which steps in and takes the place of general covariance in the anisotropic context. While the identification of the appropriate symmetry is quite subtle in the full non-linear theory, once the dust settles, the resulting theory has a spectrum which matches that of general relativity in the infrared. This goes a good way toward answering the question of how close Hořava-Lifshitz gravity can come to reproducing general relativity in the infrared regime. In the second part of the thesis we pursue

Ares I Scale Model Acoustic Test Lift-Off Acoustics

NASA Technical Reports Server (NTRS)

Counter, Douglas D.; Houston, Janie D.

2011-01-01

The lift-off acoustic (LOA) environment is an important design factor for any launch vehicle. For the Ares I vehicle, the LOA environments were derived by scaling flight data from other launch vehicles. The Ares I LOA predicted environments are compared to the Ares I Scale Model Acoustic Test (ASMAT) preliminary results.

Acoustic Neuroma Association

MedlinePlus

... Gold Sponsor NSPC Brain & Spine Surgery Learn More Gold Sponsor University of Colorado Acoustic Neuroma Program and Rocky Mountain Gamma Knife Center Learn More Gold Sponsor USC Acoustic Neuroma Center Learn More Gold ...

Carbon Nanotube Underwater Acoustic Thermophone

DTIC Science & Technology

2016-09-23

Attorney Docket No. 300009 1 of 8 A CARBON NANOTUBE UNDERWATER ACOUSTIC THERMOPHONE STATEMENT OF GOVERNMENT INTEREST [0001] The...the Invention [0003] The present invention is an acoustically transparent carbon nanotube thermophone. (2) Description of the Prior Art [0004...Traditional acoustic transduction typically begins with the generation of electrical excitation pulsed through an amplifier into an electro- acoustic

Fused off-axis object illumination direct-to-digital holography with a plurality of illumination sources

DOEpatents

Price, Jeffery R.; Bingham, Philip R.

2005-11-08

Systems and methods are described for rapid acquisition of fused off-axis illumination direct-to-digital holography. A method of recording a plurality of off-axis object illuminated spatially heterodyne holograms, each of the off-axis object illuminated spatially heterodyne holograms including spatially heterodyne fringes for Fourier analysis, includes digitally recording, with a first illumination source of an interferometer, a first off-axis object illuminated spatially heterodyne hologram including spatially heterodyne fringes for Fourier analysis; and digitally recording, with a second illumination source of the interferometer, a second off-axis object illuminated spatially heterodyne hologram including spatially heterodyne fringes for Fourier analysis.

Nondestructive test of regenerative chambers

NASA Technical Reports Server (NTRS)

Malone, G. A.; Stauffis, R.; Wood, R.

1972-01-01

Flat panels simulating internally cooled regenerative thrust chamber walls were fabricated by electroforming, brazing and diffusion bonding to evaluate the feasibility of nondestructive evaluation techniques to detect bonds of various strength integrities. Ultrasonics, holography, and acoustic emission were investigated and found to yield useful and informative data regarding the presence of bond defects in these structures.

Nondestructive evaluation: A survey of NASA contributions, chapter 1, Chapter 11, cover page, acknowledgements, and contents

NASA Technical Reports Server (NTRS)

1972-01-01

A survey of nondestructive evaluation (NDE) technology, which is discussed in terms of popular demands for a greater degree of quality, reliability, and safety in industrial products, is presented as an overview of the NDE field to serve the needs of middle management. Three NDE methods are presented: acoustic emission, the use of coherent (laser)light, and ultrasonic holography.

The accidental (acoustical) tourist

NASA Astrophysics Data System (ADS)

Van Kirk, Wayne

2002-11-01

The acoustical phenomenon observed at an ancient temple in the Great Ball Court at Chichen Itza was described as ''little short of amazing--an ancient whispering gallery'' by Silvanus G. Morley, leader of the Carnegie Institute's archaeological team that excavated and restored these structures in the 1920s. Since then, many others have experienced the extraordinary acoustics at Chichen Itza and other Maya sites. Despite these reports, archaeologists and acousticians have until recently shown little interest in understanding these phenomena. After experiencing Chichen Itza's remarkable acoustics as a tourist in 1994, the author commenced collecting and disseminating information about acoustical phenomena there and at other Mayan sites, hoping to stimulate interest among archaeologists and acousticians. Were these designs accidental or intentional? If intentional, how was the knowledge obtained? How were acoustical features used? This paper highlights the author's collection of anecdotal reports of mysterious Mayan acoustics (http://http://www.ianlawton.com/pa1.htm<\\/A>), recommended reading for scientists and engineers who wish to pursue this fascinating study. Also recounted are some of the reactions of archaeologists-ranging from curious, helpful, and insightful to humorous and appalling--to outsiders' efforts to bring serious scientific attention to the new field of acoustical archaeology.

Developments in Acoustic Metamaterials for Acoustic Ground Cloaks

NASA Astrophysics Data System (ADS)

Kerrian, Peter Adam

The objective of acoustic cloaking is to eliminate both the back scattered and forward scattered acoustic fields by redirecting the incident wave around an object. Acoustic ground cloaks, which conceal an object on a rigid reflecting surface, utilize a linear coordinate transformation to map the flat surface to a void by compressing space into two cloaking regions consisting of a homogeneous anisotropic acoustic metafluid. Transformation acoustics allows for the realization of a coordinate transformation through a reinterpretation of the scale factors as a new material in the original coordinate system. Previous work has demonstrated at least three types of unit cells exhibit homogeneous anisotropic mass density and homogeneous isotropic bulk modulus: alternating layers of homogeneous isotropic fluids, perforated plates and solid inclusions. The primary focus of this dissertation is to demonstrate underwater anisotropic mass density with a solid inclusion unit cell and realize an underwater perforated plate acoustic ground cloak. An in depth analysis into the methods used to characterize the effective material parameters of solid inclusion unit cells with water as the background fluid was performed for both single inclusion unit cells as well as multi-inclusion unit cells. The degree of density anisotropy obtainable for a rigid single inclusion unit cell is limited by the size of the inclusion. However, a greater degree of anisotropy can be achieved by introducing additional inclusions into the unit cell design. For example, including a foam material that is less dense than the background fluid, results in an anisotropic density tensor with one component greater than and one component less than the value of the background fluid. The results of a parametric study determined that for a multi-inclusion unit cell, the effective material parameters can be controlled by the dimensions of the rigid inclusion as well as the material parameters and dimensions of the foam

Diagnosing Acoustic Neuroma

MedlinePlus

... Other symptoms of the acoustic neuroma include asymmetric tinnitus (ringing in the ear), dizziness and disequilibrium (difficulty ... than 80% of patients having acoustic neuromas have tinnitus. Tinnitus is usually described as hissing, ringing, buzzing ...

Acoustic field modulation in regenerators

NASA Astrophysics Data System (ADS)

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

2016-12-01

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

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

NASA Technical Reports Server (NTRS)

Vargas, Magda B.; Counter, Douglas D.

2011-01-01

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

Acoustics of a planetarium

NASA Astrophysics Data System (ADS)

Shepherd, Micah; Leishman, Timothy W.; Utami, Sentagi

2005-09-01

Brigham Young University has recently constructed a planetarium with a 38-ft.-diameter dome. The facility also serves as a classroom. Since planetariums typically have poor acoustics due to their domed ceiling structures, acoustical recommendations were requested before its construction. The recommendations were made in an attempt to create an acceptable listening environment for lectures and other listening events. They were based in part on computer models and auralizations intended to predict the effectiveness of several acoustical treatments on the outer walls and on the dome itself. The recommendations were accepted and the planetarium was completed accordingly. A series of acoustical measurements was subsequently made in the room and the resulting acoustical parameters were mapped over the floor plan. This paper discusses these results and compares them with the predictions of the computer models.

Investigation into the Effect of Acoustic Radiation Force and Acoustic Streaming on Particle Patterning in Acoustic Standing Wave Fields

PubMed Central

Yang, Yanye; Ni, Zhengyang; Guo, Xiasheng; Luo, Linjiao; Tu, Juan; Zhang, Dong

2017-01-01

Acoustic standing waves have been widely used in trapping, patterning, and manipulating particles, whereas one barrier remains: the lack of understanding of force conditions on particles which mainly include acoustic radiation force (ARF) and acoustic streaming (AS). In this paper, force conditions on micrometer size polystyrene microspheres in acoustic standing wave fields were investigated. The COMSOL® Mutiphysics particle tracing module was used to numerically simulate force conditions on various particles as a function of time. The velocity of particle movement was experimentally measured using particle imaging velocimetry (PIV). Through experimental and numerical simulation, the functions of ARF and AS in trapping and patterning were analyzed. It is shown that ARF is dominant in trapping and patterning large particles while the impact of AS increases rapidly with decreasing particle size. The combination of using both ARF and AS for medium size particles can obtain different patterns with only using ARF. Findings of the present study will aid the design of acoustic-driven microfluidic devices to increase the diversity of particle patterning. PMID:28753955

Ocean acoustic reverberation tomography.

PubMed

Dunn, Robert A

2015-12-01

Seismic wide-angle imaging using ship-towed acoustic sources and networks of ocean bottom seismographs is a common technique for exploring earth structure beneath the oceans. In these studies, the recorded data are dominated by acoustic waves propagating as reverberations in the water column. For surveys with a small receiver spacing (e.g., <10 km), the acoustic wave field densely samples properties of the water column over the width of the receiver array. A method, referred to as ocean acoustic reverberation tomography, is developed that uses the travel times of direct and reflected waves to image ocean acoustic structure. Reverberation tomography offers an alternative approach for determining the structure of the oceans and advancing the understanding of ocean heat content and mixing processes. The technique has the potential for revealing small-scale ocean thermal structure over the entire vertical height of the water column and along long survey profiles or across three-dimensional volumes of the ocean. For realistic experimental geometries and data noise levels, the method can produce images of ocean sound speed on a smaller scale than traditional acoustic tomography.

Acoustic well cleaner

DOEpatents

Maki, Jr., Voldi E.; Sharma, Mukul M.

1997-01-21

A method and apparatus are disclosed for cleaning the wellbore and the near wellbore region. A sonde is provided which is adapted to be lowered into a borehole and which includes a plurality of acoustic transducers arranged around the sonde. Electrical power provided by a cable is converted to acoustic energy. The high intensity acoustic energy directed to the borehole wall and into the near wellbore region, redissolves or resuspends the material which is reducing the permeability of the formation and/or restricting flow in the wellbore.

Investigation of Jet Noise Using Optical Holography

DOT National Transportation Integrated Search

1973-04-01

Holographic interferograms have been made of cold, laboratory scale, supersonic air and nitrogen jet in the mach number range of 2.1 ot 3.4, and of helium jets in the mach number range of 1.5 to 2.95. These holograms demonstrate that the acoustic fie...

Vowel Acoustic Space Development in Children: A Synthesis of Acoustic and Anatomic Data

ERIC Educational Resources Information Center

Vorperian, Houri K.; Kent, Ray D.

2007-01-01

Purpose: This article integrates published acoustic data on the development of vowel production. Age specific data on formant frequencies are considered in the light of information on the development of the vocal tract (VT) to create an anatomic-acoustic description of the maturation of the vowel acoustic space for English. Method: Literature…