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Sample records for volume holographic correlator

  1. Read-only high accuracy volume holographic optical correlator

    NASA Astrophysics Data System (ADS)

    Zhao, Tian; Li, Jingming; Cao, Liangcai; He, Qingsheng; Jin, Guofan

    2011-10-01

    A read-only volume holographic correlator (VHC) is proposed. After the recording of all of the correlation database pages by angular multiplexing, a stand-alone read-only high accuracy VHC will be separated from the VHC recording facilities which include the high-power laser and the angular multiplexing system. The stand-alone VHC has its own low power readout laser and very compact and simple structure. Since there are two lasers that are employed for recording and readout, respectively, the optical alignment tolerance of the laser illumination on the SLM is very sensitive. The twodimensional angular tolerance is analyzed based on the theoretical model of the volume holographic correlator. The experimental demonstration of the proposed read-only VHC is introduced and discussed.

  2. Volume holographic gratings: fabrication and characterization

    NASA Astrophysics Data System (ADS)

    Bianco, G.; Ferrara, M. A.; Borbone, F.; Roviello, A.; Pagliarulo, V.; Grilli, S.; Ferraro, P.; Striano, V.; Coppola, G.

    2015-05-01

    Volume Holographic Gratings is designed and fabricated to obtain a simple, lightweight and cheap light deflector. The entire process, starting from the chemical preparation of the photosensitive material, to the recording of Volume Holographic Gratings and their appropriate characterization, is reported. The recording material was a new photopolymer sensitive to light at 532nm. Results showed that the recorded Volume Holographic Grating presents a very high value of the diffraction efficiency, up to 94%. In addition, a flexible material is used to write Volume Holographic Gratings.

  3. Multilayer Volume Holographic Optical Memory

    NASA Technical Reports Server (NTRS)

    Markov, Vladimir; Millerd, James; Trolinger, James; Norrie, Mark; Downie, John; Timucin, Dogan; Lau, Sonie (Technical Monitor)

    1998-01-01

    We demonstrate a scheme for volume holographic storage based on the features of shift selectivity of a speckle reference wave hologram. The proposed recording method allows more efficient use of the recording medium and increases the storage density in comparison with spherical or plane-wave reference beams. Experimental results of multiple hologram storage and replay in a photorefractive crystal of iron-doped lithium niobate are presented. The mechanism of lateral and longitudinal shift selectivity are described theoretically and shown to agree with experimental measurements.

  4. Holographic lens for optical correlator

    NASA Astrophysics Data System (ADS)

    Semenov, G. B.; Koreshev, S. N.; Pavlov, A. V.; Shubnikov, Y. I.

    1984-08-01

    Aberrations in holographic optics place limitations on the information capacity of the data that can be processed by holographic optical correlators. Nonetheless, the aberrations can be reduced sufficiently for an extensive class of devices such as those for real time data input using space-time light modulators and a TV channel. This paper analyzes the aberrations of holographic lenses, demonstrating the feasibility of an off-axis lens for correlation image analysis with aberrations similar to an axial lens. A requirement that the wave aberrations not exceed a quarter-wavelength was placed on the lens. Equations are solved for coma and astigmatism, and used to plot the maximum wave aberrations as a function of the spatial frequency of the proposed signal for three cases: (1) normal propagation of a diverging beam and oblique propagation of a plane beam; (2) oblique propagation of diverging and parallel beams, symmetrical with respect to the normal to the photographic plate; (3) oblique propagation of the diverging beam and normal propagation of the parallel beam. The angle between the beam axes was 45 deg in all cases, with a lens focal length of 350 mm and an operture of 32 mm.

  5. In-line digital holographic imaging in volume holographic microscopy.

    PubMed

    Zhai, Xiaomin; Lin, Wei-Tang; Chen, Hsi-Hsun; Wang, Po-Hao; Yeh, Li-Hao; Tsai, Jui-Chang; Singh, Vijay Raj; Luo, Yuan

    2015-12-01

    A dual-plane in-line digital holographic imaging method incorporating volume holographic microscopy (VHM) is presented to reconstruct objects in a single shot while eliminating zero-order and twin-image diffracted waves. The proposed imaging method is configured such that information from different axial planes is acquired simultaneously using multiplexed volume holographic imaging gratings, as used in VHM, and recorded as in-line holograms where the corresponding reference beams are generated in the fashion of Gabor's in-line holography. Unlike conventional VHM, which can take axial intensity information only at focal depths, the proposed method digitally reconstructs objects at any axial position. Further, we demonstrate the proposed imaging technique's ability to effectively eliminate zero-order and twin images for single-shot three-dimensional object reconstruction. PMID:26625046

  6. Sensitivity of volume holographic optical computing

    NASA Astrophysics Data System (ADS)

    Yi, Yao; Cao, Liang-cai; Zheng, Tian-xiang; Guo, Wei; He, Qing-sheng; Jin, Guo-fan

    2013-08-01

    Volume holographic correlator (VHC) calculates the inner product between two data pages through parallel optical correlation. It has great potential in the field of information processing and real-time identification because of its high storage density, integration of storing and computing, and multi-channel parallel processing ability. Current studies on the improvements of VHC mainly focus on the processing speed and channel uniformity. However, the accuracy of the VHC is mainly related to the minimum output intensity varying with the spatial light modulator (SLM) pixel intensity, which is the sensitivity of the VHC. In this work, the Minimum Pixel Block Size (MPBS) is proposed to characterize the sensitivity of the VHC. The Effective Number of Pixels (ENP) is employed to evaluate the optical computing ability, which is more accurate compared with traditional calculating method based on the pixel number of the SLM. The theoretical and experimental results are instructive in the system design. Desired system performance can be achieved by optimizing the system parameters.

  7. Optical Correlator With Complex Holographic Filter

    NASA Technical Reports Server (NTRS)

    Chao, Tien-Hsin

    1992-01-01

    Experimental real-time optical correlator includes complex-valued holographic filter computed from one of two input scenes. Made more tolerant of errors in patterns to be recognized. Filter function essentially coded hologram computed by Burchhardt's method, in which complex value of each pixel of fast Fourier transform of image represented by three real, nonnegative numbers. In generating optical correlator according to method, phasor of each pixel in Fourier transform represented by intensities in three adjacent pixels.

  8. Hybrid integrated optics in volume holographic photopolymer

    NASA Astrophysics Data System (ADS)

    McLeod, Robert R.; Sullivan, Amy C.; Grabowski, Matthew W.; Scott, Timothy F.

    2004-10-01

    Traditional planar lightwave circuits fabricated from lithographically-patterned waveguides in glasses, semi-conductors or polymers cannot accommodate the wide range of materials required by typical optical devices. In addition, such waveguides are nearly always defined in the material surface and thus can support only a limited density of interconnects and suffer poor performance at waveguide crossings. Furthermore, the inflexibility of lithographic approaches - including both waveguides and "silicon-bench" methods - requires optical sub-components with unreasonable and expensive tolerances. We propose an alternative integrated optics platform based on 3D direct-write lithography into an optically addressable encapsulant. Arbitrary micro-optics are first embedded in a liquid monomer which is then cured into a semi-solid pre-polymer. It is essential that this step take place with minimal shrinkage to avoid stresses. A scanning confocal microscope then nondestructively identifies the component locations and their tolerances. The controller customizes the circuit design to accommodate these tolerances and then scans a 0.3 to 0.6 NA focus within the volume of the holographic polymer to create waveguides, lenses or other passive interconnects with one micron resolution. A final incoherent exposure cures and solidifies the polymer, finishing the process. The resulting hybrid optoelectronic circuits contain 3D routed waveguides interconnecting active and passive micro-optic devices in environmentally robust, hermetically sealed packages. A feature of particular interest is the ability to write waveguides directly off of the tips of embedded fibers, passively interfacing the circuits to fiber. We show that polymers developed for holographic data storage have the properties required for this application.

  9. Reliability of content-addressable data search in a defocused volume holographic data storage system.

    PubMed

    Das, Bhargab; Joseph, Joby; Singh, Kehar

    2010-02-10

    We investigate for suitable methods that enable reliable content-addressable data search in a defocused volume holographic data storage system. Two techniques have been introduced and are shown to overcome the shortcomings of the known methods used to perform content searching in defocused holographic recording geometry. In effect, we remove the deterministic errors that result because of the presence of nonmatching database records, producing almost the same correlation scores as the true targeted correlation scores. Such deterministic errors give rise to erroneous search outcomes and reduce the speed advantage of the parallel holographic data search. We present experimental results and discuss the improvements offered by the two introduced methods in terms of storage density and measured correlation scores. Both the methods of modified-balanced and 25% sparse modulation coded data pages are found to produce good results, negating the undesired correlation characteristics. PMID:20154744

  10. Volume polarization holographic recording in thick photopolymer for optical memory.

    PubMed

    Lin, Shiuan Huei; Cho, Sheng-Lung; Chou, Shin-Fu; Lin, June Hua; Lin, Chih Min; Chi, Sien; Hsu, Ken Yuh

    2014-06-16

    Based on a vector wave theory of volume holograms, dependence of holographic reconstruction on the polarization states of the writing and reading beams is discussed. It is found that under paraxial approximation the circular polarization holograms provide a better distinction of the reading beams. Characteristics of recording polarization holograms in thick phenanthrenequinone-doped poly(methyl methacrylate) (PQ/PMMA) photopolymer are experimentally investigated. It is found that the circular polarization holographic recording possesses better dynamic range and material sensitivity, and a uniform spatial frequency response over a wide range. The performance is comparable to that of the intensity holographic recording in PQ/PMMA. Based on theoretical analyses and the material properties, a polarization multiplexing holographic memory using circularly polarization recording configuration for increasing storage capacity has been designed and experimentally demonstrated. PMID:24977588

  11. Second-harmonic diffraction from holographic volume grating.

    PubMed

    Nee, Tsu-Wei

    2006-10-01

    The full polarization property of holographic volume-grating enhanced second-harmonic diffraction (SHD) is investigated theoretically. The nonlinear coefficient is derived from a simple atomic model of the material. By using a simple volume-grating model, the SHD fields and Mueller matrices are first derived. The SHD phase-mismatching effect for a thick sample is analytically investigated. This theory is justified by fitting with published experimental SHD data of thin-film samples. The SHD of an existing polymethyl methacrylate (PMMA) holographic 2-mm-thick volume-grating sample is investigated. This sample has two strong coupling linear diffraction peaks and five SHD peaks. The splitting of SHD peaks is due to the phase-mismatching effect. The detector sensitivity and laser power needed to measure these peak signals are quantitatively estimated. PMID:16985536

  12. Hybrid surface-relief/volume one dimensional holographic gratings

    NASA Astrophysics Data System (ADS)

    Lucchetta, D. E.; Spegni, P.; Di Donato, A.; Simoni, F.; Castagna, R.

    2015-04-01

    Many one dimensional optically patterned photopolymers exist as surface relief or volume phase gratings. However, as far as we know, holographically recorded acrylate-based gratings in which both configurations are present are not described in literature. In this work we report a two steps fabrication process in which a large-area high-resolution hybrid volume/surface relief grating phase gratings is created in a thin film of multiacrylate material spinned on a proper designed substrate. Optical and morphological investigations, made on the optically patterned area, confirm the presence of a one dimensional double (surface relief and Bragg volume phase) periodic structure.

  13. Holographic security system based on image domain joint transform correlator

    NASA Astrophysics Data System (ADS)

    Borisov, Michael; Odinokov, Sergey B.; Bondarev, Leonid A.; Kurakin, Sergey V.; Matveyev, Sergey V.; Belyaev, V. S.

    2002-04-01

    We describe holographic security system providing machine reading of the holographic information and matching it with the reference one by optical means. The security holographic mark includes several test holograms and should be applied to a carrier: ID-card, paper seal etc. Each of the holograms stores a part of entire image, stored in the reference hologram. Image domain JTC is used to match the images retrieved from the holograms. Being recorded and retrieved, the images provides correlation peaks with special positions, with a strict dependence on the tested and reference holograms mutual shifts. The system proposed works like usual JTC with a few useful differences. The image domain recognizing is a result of Fresnel holographic technique of the images recording. It provides more effective usage of the light addressed SLM (LASLM) work pupil and resolution in more simple and compact device. Few correlation peaks enhances the device recognizing probability. We describe the real-time experimental arrangement based on LASLM. The experimental results are in a good correspondence with computer simulations. We also show in practice that good results may be obtained while using the image domain JTC technique in despite of the low LASLM resolution and the device compact size.

  14. Improved data search by zero-order (dc) peak filtering in a defocused volume holographic content-addressable memory.

    PubMed

    Das, Bhargab; Joseph, Joby; Singh, Kehar

    2009-01-01

    Defocusing the recording material away from the Fourier plane is necessary to reduce the strong dc component and produce a more homogeneous object beam distribution in the hologram plane in volume holographic digital data-storage systems with amplitude-modulated data pages. However, content-addressable searching with defocused recording results in higher cross-correlation peak intensities. We present a method for performing a faithful content-addressable search in a defocused volume holographic data-storage system. A new dc-filtered content-addressable search method for defocused volume holographic data-storage systems with binary data pages is demonstrated. Both simulation and experimental results are presented. The experimental results show good discrimination capability and confirm the feasibility of the proposed technique. PMID:19107172

  15. All-optical nonlinear holographic correlation using bacteriorhodopsin films

    NASA Astrophysics Data System (ADS)

    Thoma, Ralph; Dratz, Michael; Hampp, Norbert

    1995-05-01

    Films made of the halobacterial photochrome bacteriorhodopsin (BR) can be used in a number of holographic real-time applications. Their application as active material in a dual-axis joint- Fourier-transform (DAJFT) real-time correlator was shown recently. The BR films have a strong nonlinear intensity dependence on the light-induced absorption and refractive-index changes. Therefore the holographic diffraction efficiency also shows a nonlinear dependence on the writing intensity. We investigate the effect of this nonlinearity on the result of the correlation process in a bacteriorhodopsin-based DAJFT correlator. Numerical models supporting the experimental observations are presented. It was found that the BR film combines the holographic function for most objects with that of a spatial bandpass filter, whose center frequency is tuned by the writing intensity. This results in smaller peak widths and a suppression of the sidelobes. BR films allow the application of this nonlinear behavior in real time to the all-optical correlation process.

  16. Holographic thermalization with initial long range correlation

    NASA Astrophysics Data System (ADS)

    Lin, Shu

    2016-01-01

    We studied the evolution of the Wightman correlator in a thermalizing state modeled by AdS3 -Vaidya background. We gave a prescription for calculating the Wightman correlator in coordinate space without using any approximation. For equal-time correlator ⟨ O (v ,x )O (v ,0 )⟩ , we obtained an enhancement factor v2 due to long range correlation present in the initial state. This was missed by previous studies based on geodesic approximation. We found that the long range correlation in initial state does not lead to significant modification to thermalization time as compared to known results with generic initial state. We also studied the spatially integrated Wightman correlator and showed evidence on the distinction between long distance and small momentum physics for an out-of-equilibrium state. We also calculated the radiation spectrum of particles weakly coupled to O and found that lower frequency mode approaches thermal spectrum faster than high frequency mode.

  17. Improved associative recall of binary data in volume holographic memories

    NASA Astrophysics Data System (ADS)

    Betzos, George A.; Laisné, Alexandre; Mitkas, Pericles A.

    1999-11-01

    A new technique is presented that improves the results of associative recall in a volume holographic memory system. A background is added to the normal search argument to increase the amount of optical power that is used to reconstruct the reference beams in the crystal. This is combined with post-processing of the captured image of the reference beams. The use of both the background and post-processing greatly improves the results by allowing associative recall using small arguments. In addition, the number of false hits is reduced and misses are virtually eliminated.

  18. An external cavity diode laser using a volume holographic grating

    NASA Astrophysics Data System (ADS)

    Chuang, Ho-Chiao; Chang, Chang-Ray; Chen, Chun-Chia; Chang, Ming-Shien

    2012-10-01

    This study presents an external cavity diode laser (ECDL) system, utilizing a volume holographic grating (VHG) and a microfabricated silicon flexure as the VHG holder. The laser design is aimed for easy assembly, controllability, and better stability of the laser cavity. The laser frequency was stabilized to a D2 transition of rubidium at 780.247 nm, with a mode-hop-free tuning range of 16 GHz and 9.6 GHz with and without feed-forward on the diode injection current. The measured linewidth was 850 kHz in 500 s, qualified for laser cooling experiments.

  19. Overloaded phase-code multiplexing for volume holographic storage.

    PubMed

    Berger, Gernot; Dietz, Mathias; Denz, Cornelia

    2008-06-01

    Overloaded phase codes for volume holographic data storage are introduced. In contrast to any previous phase-code design, overloaded phase codes enable multiplexing of a number of data pages that exceeds the number of utilized reference beams. In this way the achievable data capacity can be augmented. Overloaded codes are generated by extending multilevel phase codes based on the discrete Fourier transform. We demonstrate multiplexing of 70 analog pages by means of 64 reference beams. The analysis of reconstructed digital data pages suggests that a capacity gain of up to 15% is reasonable. PMID:18516191

  20. Holographic thermalization with initial long range correlation

    DOE PAGESBeta

    Lin, Shu

    2016-01-19

    Here, we studied the evolution of the Wightman correlator in a thermalizing state modeled by AdS3-Vaidya background. A prescription was given for calculating the Wightman correlator in coordinate space without using any approximation. For equal-time correlator , we obtained an enhancement factor v2 due to long range correlation present in the initial state. This was missed by previous studies based on geodesic approximation. Moreover, we found that the long range correlation in initial state does not lead to significant modification to thermalization time as compared to known results with generic initial state. We also studied the spatially integrated Wightman correlatormore » and showed evidence on the distinction between long distance and small momentum physics for an out-of-equilibrium state. We also calculated the radiation spectrum of particles weakly coupled to O and found that lower frequency mode approaches thermal spectrum faster than high frequency mode.« less

  1. Aspects of current correlators in holographic theories with hyperscaling violation

    NASA Astrophysics Data System (ADS)

    Edalati, Mohammad; Pedraza, Juan F.

    2013-10-01

    We study the low-energy and low-momentum behavior of current correlators in a class of holographic zero-temperature, finite-density critical theories which do not respect the hyperscaling relation. The dual holographic description is assumed to be given by probe D-branes embedded in background geometries characterized by a dynamical critical exponent z and a hyperscaling violation exponent θ. We show that a subset of these theories with 1≤z<2(1-θ/d) exhibit a stable, linearly dispersing mode in their low-energy spectrum of excitations. This mode, which appears as a pole in the retarded correlators of charge density and longitudinal currents, has some characteristics similar to that of the zero sound in Fermi liquids. Given some reasonable assumptions, we argue that the class of theories with θ=d-1 that logarithmically violate the area law in the entanglement entropy in a manner reminiscent of theories with Fermi surfaces does not exhibit a zero-sound-like mode in the low-energy spectrum of the probe sector. Furthermore, utilizing the holographic Wilsonian approach, we explicitly show that such a mode has a natural interpretation as a Goldstone boson arising from the spontaneous breaking of a specific symmetry.

  2. The Impact of Volume Phase Holographic Filters and Gratings on the Development of Raman Instrumentation

    ERIC Educational Resources Information Center

    Owen, Harry

    2007-01-01

    Volume phase holographic (VPH) optical elements have made a major contribution to Raman spectroscopy by providing notch filters, and VPH gratings that provide remarkable performance advantages over previous technologies. Holographic notch filters have eliminated Rayleigh scattered laser light from single monochromators, thereby contributing to the…

  3. Angle amplifier based on multiplexed volume holographic gratings

    NASA Astrophysics Data System (ADS)

    Cao, Liangcai; Zhao, Yifei; He, Qingsheng; Jin, Guofan

    2008-03-01

    Angle amplifier of laser beam scanner is a widely used device in optical systems. Volume holographic optical elements can be applied in the angle amplifier. Compared with the traditional angle amplifier, it has the advantages of high angle resolution, high diffraction efficiency, small size, and high angle magnification and flexible design. Bragg anglewavelength- compensating recording method is introduced. Because of the Bragg compensatory relation between angle and wavelength, this device could be recorded at another wavelength. The design of the angle amplifier recording at the wavelength of 514.2nm for the working wavelength of 632.8nm is described. An optical setup for recording the angle amplifier device is designed and discussed. Experimental results in the photorefractive crystal Fe:LiNbO 3 demonstrate the feasibility of the angle amplifier scheme.

  4. Photorefractive materials for nonvolatile volume holographic data storage

    PubMed

    Hesselink; Orlov; Liu; Akella; Lande; Neurgaonkar

    1998-11-01

    Optically gated recording and nonvolatile readout in a digital volume holographic data storage system that uses a pair of mutually incoherent light sources during recording and only one for readout were demonstrated recently. This approach used stoichiometric lithium niobate, which after post-growth processing gave rise to an at least two orders of magnitude improvement in sensitivity over the best materials reported previously. It is also shown that by adding certain dopants (iron and manganese) to near-stoichiometric lithium niobate, the dark storage time and gating efficiency can be increased compared with previous work. The underlying physical mechanisms of gated recording and the effectiveness of the gating process responsible for this manifold improved performance are discussed, and bipolarons and small polarons are identified as the responsible photorefractive species. PMID:9804540

  5. Soft-decision array decoding for volume holographic memory systems.

    PubMed

    Chou, W; Neifeld, M A

    2001-01-01

    We study the use of soft-decision array decoding in a volume holographic memory (VHM) system that is corrupted by interpixel interference (IPI) and detector noise. Soft-decision methods can unify equalization and error decoding. A highly parallel array decoder is presented in the context of two-dimensional low-pass channel mitigation and error correction. The new decoding algorithm is motivated by iterative turbo-decoding methods and is capable of incorporating a priori knowledge of the corrupting IPI channel during decoding. The resulting joint detection decoding algorithm is shown to offer VHM capacity and density performance superior to that of hard-decision n = 255 Reed-Solomon codes in concatenation with a Wiener filter. PMID:11151997

  6. PQ:DMNA/PMMA photopolymer having amazing volume holographic recording at wavelength of insignificant absorption.

    PubMed

    Chen, Yu-Fang; Lin, June-Hua; Lin, Shiuan Huei; Hsu, Ken Y; Whang, Wha-Tzong

    2013-06-15

    N, N-dimethyl-4-nitroaniline doping enables red-light holographic recording that was originally insensitive in thick phenanthrenequinone/poly(methyl methacrylate) photopolymer to have reasonable sensitivity. A volume hologram was recorded by a 647 nm laser with maximum diffraction efficiency of about 43% in a 2-mm-thick sample. A Bragg selectivity curve and an image hologram reconstruction are also demonstrated. These experimental results support recording material for volume holographic applications in an extended red spectral range. PMID:23938975

  7. Volume Holographic Reflection Endoscope for In-Vivo Ovarian Cancer Clinical Studies

    PubMed Central

    Howlett, I. D.; Gordon, M.; Brownlee, J. W.; Barton, J. K.; Kostuk, R. K.

    2014-01-01

    We present the design for an endoscopic system capable of imaging tissues of the ovary at two selected imaging depths simultaneously. The method utilizes a multiplexed volume hologram to select wavefronts from different depths within the tissue. It is the first demonstration of an endoscopic volume holographic imaging system. The endoscope uses both gradient index (GRIN) optical components and off the shelf singlet lenses to relay an image from the distal tip to the proximal end. The endoscope has a minimum diameter of 3.75 mm. The system length is 30 cm which is connected to a handle that includes the holographic components and optics that relay the image to a camera. Preliminary evaluation of the endoscope was performed with tissue phantoms and calibrated targets, which shows lateral resolution ≈ 4 μm at an operating wavelength of 660 nm. The hologram is recorded in phenanthraquinone doped poly methacrylate and is designed to produce images from two tissue depths. One image is obtained at the tissue surface and the second 70 μm below the surface. This method requires no mechanical scanning and acquires an image at the camera frame rate. The preliminary ex-vivo results show good correlation with histology sections of the same tissue sections. PMID:25009709

  8. Volume holographic reflection endoscope for in-vivo ovarian cancer clinical studies

    NASA Astrophysics Data System (ADS)

    Howlett, I. D.; Gordon, M.; Brownlee, J. W.; Barton, J. K.; Kostuk, R. K.

    2014-03-01

    We present the design for an endoscopic system capable of imaging tissues of the ovary at two selected imaging depths simultaneously. The method utilizes a multiplexed volume hologram to select wavefronts from different depths within the tissue. It is the first demonstration of an endoscopic volume holographic imaging system. The endoscope uses both gradient index (GRIN) optical components and off the shelf singlet lenses to relay an image from the distal tip to the proximal end. The endoscope has a minimum diameter of 3.75 mm. The system length is 30 cm which is connected to a handle that includes the holographic components and optics that relay the image to a camera. Preliminary evaluation of the endoscope was performed with tissue phantoms and calibrated targets, which shows lateral resolution ≍ 4 μm at an operating wavelength of 660 nm. The hologram is recorded in phenanthraquinone doped poly methacrylate and is designed to produce images from two tissue depths. One image is obtained at the tissue surface and the second 70 μm below the surface. This method requires no mechanical scanning and acquires an image at the camera frame rate. The preliminary ex-vivo results show good correlation with histology sections of the same tissue sections.

  9. Volume holographic printing using unconventional angular multiplexing for three-dimensional display.

    PubMed

    Cao, Liangcai; Wang, Zheng; Zhang, Hao; Jin, Guofan; Gu, Claire

    2016-08-01

    We propose and demonstrate a volume holographic printing method for dynamic three-dimensional (3D) display with an expanded space-bandwidth product (SBP) using unconventional angular multiplexing techniques. By wavefront encoding of the 3D scene, with the help of computer-generated holography, the object beam is loaded onto a 2D phase spatial light modulator (SLM) with a limited SBP. The printing method then writes a single hologram through the interference of the object beam with a reference beam as a holographic element (hogel) in the volume holographic polymer. In addition, multiple 3D scenes can be recorded and dynamically reconstructed by angular multiplexing in the same hogel location. The SBP can be increased by two orders of magnitude compared to the conventional holographic printing method, showing the potential to realize a dynamic and high-resolution 3D display. PMID:27505387

  10. Blue-sensitized nanoparticle-(thiol-ene) polymer composites for volume holographic recording

    NASA Astrophysics Data System (ADS)

    Takahashi, Jun-ichiro; Kawana, Masaru; Tomita, Yasuo

    2016-04-01

    We describe an experimental investigation of volume holographic recording in photopolymerizable thiol-ene based nanoparticle-polymer composites (NPCs) at a wavelength of 404 nm. We introduce a new photoinitiator, Irgacure819, for efficient volume holographic recording in the blue-violet spectral region and measure the photopolymerization dynamics and the holographic recording properties at its varying concentrations. It is found that doping of 0.1 wt.% Irgacure 819 provides the saturated refractive index modulation amplitude as large as 9.5×10-3 and the material recording sensitiviey as high as 1800 cm/J. These measured values are much larger than the minimum required values for holographic data storage media. It is also shown that the out-of-plane shrinkage can be suppressed more with decreasing the photoinitiator concentration. We compare these results with another blue sensitizer, Darocur TPO, to evaluate the performance of Irgacure 819.

  11. Polarization-based all-optical logic operations in volume holographic photopolymer

    NASA Astrophysics Data System (ADS)

    Li, Chengmingyue; Cao, Liangcai; Li, Jingming; Wang, Zheng; Jin, Guofan

    2014-11-01

    Polarization-based all-optical logic operations were realized with dual-channel polarization holographic recording system. The polarization property of 9, 10-phenanthrenequinone-doped poly-methyl methacrylate (PQ/PMMA) photopolymer is investigated experimentally. To accurately represent the optical operations, the diffraction efficiency of parallel and orthogonal polarization recording in PQ/PMMA with the thickness of 1 mm are characterized for holographic recording and reconstruction process. A dual-channel polarization holographic recording system is set up for simultaneously recording two input pages. By changing the polarization state of the diffraction beam, all-optical logic OR and NAND operations are realized in the volume holograms. The polarization-based all-optical logic operations in the volume holographic photopolymer may pave a way for practical all-optical logic devices with high speed and large information capacity.

  12. Phase aberration correction by correlation in digital holographic adaptive optics

    PubMed Central

    Liu, Changgeng; Yu, Xiao; Kim, Myung K.

    2013-01-01

    We present a phase aberration correction method based on the correlation between the complex full-field and guide-star holograms in the context of digital holographic adaptive optics (DHAO). Removal of a global quadratic phase term before the correlation operation plays an important role in the correction. Correlation operation can remove the phase aberration at the entrance pupil plane and automatically refocus the corrected optical field. Except for the assumption that most aberrations lie at or close to the entrance pupil, the presented method does not impose any other constraints on the optical systems. Thus, it greatly enhances the flexibility of the optical design for DHAO systems in vision science and microscopy. Theoretical studies show that the previously proposed Fourier transform DHAO (FTDHAO) is just a special case of this general correction method, where the global quadratic phase term and a defocus term disappear. Hence, this correction method realizes the generalization of FTDHAO into arbitrary DHAO systems. The effectiveness and robustness of this method are demonstrated by simulations and experiments. PMID:23669707

  13. Photopolymer-Based Volume Holographic Optical Elements: Design and Possible Applications

    NASA Astrophysics Data System (ADS)

    Bianco, G.; Ferrara, M. A.; Borbone, F.; Roviello, A.; Striano, V.; Coppola, G.

    2015-12-01

    In this paper, Volume Holographic Optical Elements (V-HOEs), such as holographic gratings and spherical lenses, are designed and fabricated by using a prototype of photopolymer. The recording process of V-HOEs and their appropriate characterization are described. Moreover, V-HOEs possible applications as solar concentrator are investigated and results are discussed. Finally, a system that allows passive solar tracking is proposed and preliminary results are reported.

  14. Volume-holographic memory for laser threat discrimination

    NASA Astrophysics Data System (ADS)

    Delong, Mark L.; Duncan, Bradley D.; Parker, Jack H., Jr.

    1996-10-01

    Using conventional volume-holographic angle multiplexing in an Fe:LiNbO3 crystal, we have developed a compact laser threat discriminator, intended for aircraft integration, that optically detects laser spatial coherence and angle of arrival while simultaneously rejecting incoherent background sources, such as the Sun. The device is intended for a specific type of psychophysical laser attack against U.S. Air Force pilots, namely, third-world-country exploitation of inexpensive and powerful cw Ar-ion or doubled Nd:YAG lasers in the visible spectrum to blind or disorient U.S. pilots. The component does not solve the general tactical laser weapon situation, which includes identifying precision-guided munitions, range finders, and lidar systems that use pulsed infrared lasers. These are fundamentally different threats requiring different detector solutions. The device incorporates a sequence of highly redundant, simple black-and-white warning patterns that are keyed to be reconstructed as the incident laser threat, playing the role of an uncooperative probe beam, changes angle with respect to the crystal. The device tracks both azimuth and elevation, using a nonconventional hologram viewing system. Recording and playback conditions are simplified because nonzero cross talk is a desirable feature of this discriminator, inasmuch as our application requires a nonzero probability of detection for arbitrary directions of arrival within the sensor's field of view. The device can exploit phase-matched grating trade-off with probe-beam wavelength, accommodating wavelength-tunable threats, while still maintaining high direction-of-arrival tracking accuracy. .

  15. Computer simulation of reflective volume grating holographic data storage.

    PubMed

    Gombköt, Balázs; Koppa, Pál; Süt, Attila; L Rincz, Em Ke

    2007-07-01

    The shift selectivity of a reflective-type spherical reference wave volume hologram is investigated using a nonparaxial numerical modeling based on a multiple-thin-layer implementation of a volume integral equation. The method can be easily parallelized on multiple computers. According to the results, the falloff of the diffraction efficiency due to the readout shift shows neither Bragg zeros nor oscillation with our parameter set. This agrees with our earlier study of smaller and transmissive holograms. Interhologram cross talk of shift-multiplexed holograms is also modeled using the same method, together with sparse modulation block coding and correlation decoding of data. Signal-to-noise ratio and raw bit error rate values are calculated. PMID:17728833

  16. Crosstalk analysis of multilayer collinear volume holographic data storage

    NASA Astrophysics Data System (ADS)

    Liu, Jinqiu; Cao, Liangcai; Li, Chengmingyue; Li, Jianhua; He, Qingsheng; Jin, Guofan

    2013-09-01

    An optical model to describe the reconstructed image of the collinear holographic data storage system is presented. The 2-D shape of the recording spot in the medium is simulated. The system structure parameters that influence the signal-to-noise ratio (SNR) of the reconstructed image are investigated in order to choose proper optical components to improve data storage density of the system. The role of the random binary phase mask (RBPM) utilized in the multilayer collinear holographic system is investigated. It is proved that the inter-layer crosstalk can be effectively suppressed by using different RBPMs. Different layers of data pages can be recorded with the SNR increased by a factor of six at least and the shift selectivity along z-axis can also be improved significantly.

  17. Information theoretic limits to the capacity of volume holographic optical memory.

    PubMed

    Neifeld, M A; Chou, W C

    1997-01-10

    We derive the information theoretic limit to storage capacity in volume holographic optical memories for the limiting cases of dominant intensity noise (Gaussian noise) and dominant field noise (Rician noise). These capacity bounds are compared with the performance achievable using simple Reed-Solomon error-correcting codes. PMID:18250702

  18. Associative memory in a volume holographic medium: a new approach based on operator theory

    NASA Astrophysics Data System (ADS)

    Pashaie, Ramin

    2014-07-01

    In this article, we present a new method for holographic implementation of associative memories. In the current approach, the memory capacity is implemented in the form of spatial perturbation of refractive index within the volume of a three dimensional holographic material. We use operator theory to solve the inverse problem and compute a closed-form solution for the spatial distribution of the perturbation considering any arbitrary set of input-output prototype vectors. Simplicity of the hardware is the major advantage of the current method.

  19. Low-density parity-check codes for volume holographic memory systems.

    PubMed

    Pishro-Nik, Hossein; Rahnavard, Nazanin; Ha, Jeongseok; Fekri, Faramarz; Adibi, Ali

    2003-02-10

    We investigate the application of low-density parity-check (LDPC) codes in volume holographic memory (VHM) systems. We show that a carefully designed irregular LDPC code has a very good performance in VHM systems. We optimize high-rate LDPC codes for the nonuniform error pattern in holographic memories to reduce the bit error rate extensively. The prior knowledge of noise distribution is used for designing as well as decoding the LDPC codes. We show that these codes have a superior performance to that of Reed-Solomon (RS) codes and regular LDPC counterparts. Our simulation shows that we can increase the maximum storage capacity of holographic memories by more than 50 percent if we use irregular LDPC codes with soft-decision decoding instead of conventionally employed RS codes with hard-decision decoding. The performance of these LDPC codes is close to the information theoretic capacity. PMID:12593489

  20. Low-density parity-check codes for volume holographic memory systems

    NASA Astrophysics Data System (ADS)

    Pishro-Nik, Hossein; Rahnavard, Nazanin; Ha, Jeongseok; Fekri, Faramarz; Adibi, Ali

    2003-02-01

    We investigate the application of low-density parity-check (LDPC) codes in volume holographic memory (VHM) systems. We show that a carefully designed irregular LDPC code has a very good performance in VHM systems. We optimize high-rate LDPC codes for the nonuniform error pattern in holographic memories to reduce the bit error rate extensively. The prior knowledge of noise distribution is used for designing as well as decoding the LDPC codes. We show that these codes have a superior performance to that of Reed-Solomon (RS) codes and regular LDPC counterparts. Our simulation shows that we can increase the maximum storage capacity of holographic memories by more than 50 percent if we use irregular LDPC codes with soft-decision decoding instead of conventionally employed RS codes with hard-decision decoding. The performance of these LDPC codes is close to the information theoretic capacity.

  1. Position feedback system for volume holographic storage media

    DOEpatents

    Hays, Nathan J.; Henson, James A.; Carpenter, Christopher M.; Akin, Jr.. William R.; Ehrlich, Richard M.; Beazley, Lance D.

    1998-07-07

    A method of holographic recording in a photorefractive medium wherein stored holograms may be retrieved with maximum signal-to noise ratio (SNR) is disclosed. A plurality of servo blocks containing position feedback information is recorded in the crystal and made non-erasable by heating the crystal. The servo blocks are recorded at specific increments, either angular or frequency, depending whether wavelength or angular multiplexing is applied, and each servo block is defined by one of five patterns. Data pages are then recorded at positions or wavelengths enabling each data page to be subsequently reconstructed with servo patterns which provide position feedback information. The method of recording data pages and servo blocks is consistent with conventional practices. In addition, the recording system also includes components (e.g. voice coil motor) which respond to position feedback information and adjust the angular position of the reference angle of a reference beam to maximize SNR by reducing crosstalk, thereby improving storage capacity.

  2. Astigmatism compensation in digital holographic microscopy using complex-amplitude correlation

    NASA Astrophysics Data System (ADS)

    Tamrin, Khairul Fikri; Rahmatullah, Bahbibi; Samuri, Suzani Mohamad

    2015-07-01

    Digital holographic microscopy (DHM) is a promising tool for a three-dimensional imaging of microscopic particles. It offers the possibility of wavefront processing by manipulating amplitude and phase of the recorded digital holograms. With a view to compensate for aberration in the reconstructed particle images, this paper discusses a new approach of aberration compensation based on complex amplitude correlation and the use of a priori information. The approach is applied to holograms of microscopic particles flowing inside a cylindrical micro-channel recorded using an off-axis digital holographic microscope. The approach results in improvements in the image and signal qualities.

  3. Optical correlation aspect of holography: from ghost-imaging to static phase-conjugation holographic associative memories

    NASA Astrophysics Data System (ADS)

    Polyanskii, P. V.; Husak, Ye. M.

    2013-12-01

    We highlight the milestones of fifty-year history of emerging holographic associative memory as the chronologically first proposed practical application of the laser holographic techniques (van Heerden, 1963). Holographic associative memories are considered here as an important aspect of correlation optics, and the forming associative response is interpreted with account of fine phase relations among numerous partial images involved into discrimination mechanism of reconstruction. Three main approaches proposed for implementation of holographic associative memories are discussed and compared, namely, classical 'linear' ghost-image holography, the associateve memories based on resonator architectures using optical feedback and thresholding algorithms, and the quadric (second-order) hologrambased associative memories.

  4. Volume holographic recording in nanoparticle-polymer composites doped with multifunctional chain transfer agents

    NASA Astrophysics Data System (ADS)

    Guo, Jinxin; Fujii, Ryuta; Tomita, Yasuo

    2015-10-01

    We report on an experimental investigation of the properties of volume holographic recording in photopolymerizable nanoparticle-polymer composites (NPCs) doped with chain transferring multifunctional di- and tri-thiols as chain transfer agents. It is shown that the incorporation of the multifunctional thiols into NPCs more strongly influences on volume holographic recording than that doped with mono-thiol since more chemical reactions involve in the polymer network formation. It is found that, as similar to the case of mono-thiol doping, there exist optimum concentrations of di- and tri-thiols for maximizing the saturated refractive index modulation. It is also seen that recording sensitivity monotonically decreases with an increase in multifunctional thiol concentration due to the partial inhibition of the photopolymerization event by excessive thiols.

  5. Characterization of volume holographic recording in photopolymerizable nanoparticle-(thiol-ene) polymer composites at 404 nm

    NASA Astrophysics Data System (ADS)

    Kawana, Masaru; Takahashi, Jun-ichiro; Yasui, Satoru; Tomita, Yasuo

    2015-02-01

    We report on the photopolymerization dynamics and the volume holographic recording properties of a thiol-ene based nanoparticle-polymer composite (NPC) doped with a blue-sensitive photoinitiator, Darocur® TPO, by using a highly coherent blue diode laser operating at a wavelength of 404 nm. Our study indicates that volume gratings recorded in the NPC amount to meeting the material requirements of refractive index modulation and material recording sensitivity for holographic data storage media. It is also found that polymerization shrinkage of recorded NPC gratings is higher than that of the same thiol-ene based NPC with a green (523 nm)-sensitive photoinitiator, Irgacure® 784/BzO2. We attribute such a difference in shrinkage to the photopolymerization dynamics at these recording wavelengths. We show that this shrinkage increase at 404 nm can be mitigated to some extent by controlling the thiol-ene stoichiometry in the NPC.

  6. Holographic kinetics for mixed volume gratings in gold nanoparticles doped photopolymer.

    PubMed

    Li, Chengmingyue; Cao, Liangcai; He, Qingsheng; Jin, Guofan

    2014-03-10

    A holographic kinetic model is proposed to quantitatively represent the dynamics of mixed volume gratings in a bulk gold nanoparticles (NPs) doped photopolymer. Due to the polymerization-driven multicomponent diffusion, the volume refractive index grating is induced by the periodic spatial distribution of photoproduct while the absorption grating is formed by the periodic spatial distribution of gold NPs. By simulating this model with the characterization of time varying absorption modulation, it is capable to describe the behavior of gold NPs in both the polymerization and the multicomponent diffusion process. The temporal evolution of refractive index modulation and absorption modulation can be extracted, respectively, from a diffraction efficiency curve by fitting the model. The established model could be an effective method for understanding the photophysical and photochemical mechanism of holographic nanocomposite. PMID:24663840

  7. Characterization of photopolymerizable nanoparticle-(thiol-ene) polymer composites for volume holographic recording at 404 nm

    NASA Astrophysics Data System (ADS)

    Kawana, Masaru; Takahashi, Jun-ichiro; Yasui, Satoru; Tomita, Yasuo

    2014-05-01

    We report on volume holographic recording in thiol-ene based nanoparticle-polymer composites (NPCs) at a wavelength of 404 nm by using a highly coherent blue diode laser. We study the photopolymerization dynamics of two types of thiol-ene based NPCs doped with different blue-sensitive initiator/sensitizer systems (Darocur ® TPO and Irgacure ® 784/BzO2) at various doping concentrations. We also characterize a volume holographic grating recorded in these two types of thiol-ene based NPCs. Such material characterization includes the refractive index modulation, the material recording sensitivity and polymerization shrinkage. It is shown that Darocur R _ TPO provides larger refractive index modulation and higher material recording sensitivity than those with Irgacure ® 784/BzO2 but these two blue-sensitive initiator/sensitizer systems amount to meeting the requirements of the refractive index modulation and the material recording sensitivity for holographic data storage. However, it is found that shrinkage reduction of a volume grating recorded in these two types of thiol-ene based NPCs at 404 nm is not as effective as the same thiol-ene based NPC doped with Irgacure ® 784/BzO2 at 532 nm.

  8. Volume polarization holographic recording in thick phenanthrenequinone-doped poly(methyl methacrylate) photopolymer.

    PubMed

    Lin, Shiuan Huei; Chen, Po-Lin; Chuang, Chun-I; Chao, Yu-Faye; Hsu, Ken Y

    2011-08-15

    Volume polarization holographic recording in phenanthrenequinone-doped poly (methyl methacrylate) photopolymer is obtained. Photoinduced birefringence in a 2 mm thick sample is measured by a phase-modulated ellipsometry. The birefringence induced in this material by linearly polarized beam at 514 nm reaches 1.2×10(-5). In addition, ability for recording volume polarization grating using two different polarization configurations is demonstrated and compared. The experimental results show that the diffraction efficiency of the hologram reaches to ∼40% by using two orthogonal circularly polarized beams. PMID:21847152

  9. Laser-induced fluorescence imaging of subsurface tissue structures with a volume holographic spatial-spectral imaging system.

    PubMed

    Luo, Yuan; Gelsinger-Austin, Paul J; Watson, Jonathan M; Barbastathis, George; Barton, Jennifer K; Kostuk, Raymond K

    2008-09-15

    A three-dimensional imaging system incorporating multiplexed holographic gratings to visualize fluorescence tissue structures is presented. Holographic gratings formed in volume recording materials such as a phenanthrenquinone poly(methyl methacrylate) photopolymer have narrowband angular and spectral transmittance filtering properties that enable obtaining spatial-spectral information within an object. We demonstrate this imaging system's ability to obtain multiple depth-resolved fluorescence images simultaneously. PMID:18794943

  10. Fundamental limitations to the spatial resolution and flow volume that can be mapped using holographic particle image velocimetry

    NASA Astrophysics Data System (ADS)

    Coupland, Jeremy M.; Lobera Salazar, Julia; Halliwell, Neil A.

    2000-08-01

    We have recently proposed a variant of holographic particle image velocimetry (HPIV) to measure three-component measurements of fluid velocity throughout an extended flow volume. In essence the technique uses double exposure holography to record the positions of seeding particles at two, close spaced constants in time. Analysis of the resulting record is achieved by computing the auto (or cross) correlation of the complex amplitude distributions transmitted by a sampling aperture placed within a real, reconstruction of the holographic image. IN the case of sparsely seeded flows, it is straightforward to show that the field transmitted by the aperture is dominated by the particle images reconstructed close to the aperture itself and the measurement is therefore attributed to the instantaneous flow velocity at the centre of the aperture. As the seeding concentration is increased, however, a significant contribution of the transmitted field is due to light scattered from more distant particles. If significant velocity gradients exist, the contribution due to distant particles is largely un- correlated and the local particle displacement can be extracted even if the field is dominated by this component. If a significant proportion of the scattered light that passes from the aperture is collected from areas in the flow with similar velocity (for example from stagnant regions or light scattered from the flow vessel) then spurious peaks can occur in the correlation signal. This paper examines the limitations on the flow volume that can be mapped at a given seeding concentration and hence the fundamental limits on the number of velocity measurements that can be retrieved from a single recording.

  11. A new approach for implementation of associative memory using volume holographic materials

    NASA Astrophysics Data System (ADS)

    Habibi, Mohammad; Pashaie, Ramin

    2012-02-01

    Associative memory, also known as fault tolerant or content-addressable memory, has gained considerable attention in last few decades. This memory possesses important advantages over the more common random access memories since it provides the capability to correct faults and/or partially missing information in a given input pattern. There is general consensus that optical implementation of connectionist models and parallel processors including associative memory has a better record of success compared to their electronic counterparts. In this article, we describe a novel optical implementation of associative memory which not only has the advantage of all optical learning and recalling capabilities, it can also be realized easily. We present a new approach, inspired by tomographic imaging techniques, for holographic implementation of associative memories. In this approach, a volume holographic material is sandwiched within a matrix of inputs (optical point sources) and outputs (photodetectors). The memory capacity is realized by the spatial modulation of refractive index of the holographic material. Constructing the spatial distribution of the refractive index from an array of known inputs and outputs is formulated as an inverse problem consisting a set of linear integral equations.

  12. Analysis of volume holographic storage allowing large-angle illumination

    NASA Astrophysics Data System (ADS)

    Shamir, Joseph

    2005-05-01

    Advanced technological developments have stimulated renewed interest in volume holography for applications such as information storage and wavelength multiplexing for communications and laser beam shaping. In these and many other applications, the information-carrying wave fronts usually possess narrow spatial-frequency bands, although they may propagate at large angles with respect to each other or a preferred optical axis. Conventional analytic methods are not capable of properly analyzing the optical architectures involved. For mitigation of the analytic difficulties, a novel approximation is introduced to treat narrow spatial-frequency band wave fronts propagating at large angles. This approximation is incorporated into the analysis of volume holography based on a plane-wave decomposition and Fourier analysis. As a result of the analysis, the recently introduced generalized Bragg selectivity is rederived for this more general case and is shown to provide enhanced performance for the above indicated applications. The power of the new theoretical description is demonstrated with the help of specific examples and computer simulations. The simulations reveal some interesting effects, such as coherent motion blur, that were predicted in an earlier publication.

  13. Practical implementation of the image domain joint transform correlator for holographic security

    NASA Astrophysics Data System (ADS)

    Borisov, Michael V.; Odinokov, Sergey B.; Bondarev, Leonid A.; Kurakin, Sergey V.

    2003-05-01

    We describe the experimental setup of the image domain joint transform correlator intended for holographic security application. The security verification routine demands two channels. The first one corresponds to the reference hologram stored in the security device. The other is a security holographic mark with several test sub-holograms, applied to a carrier: ID-card, paper seal etc. Each of the holograms stores a part of entire image, stored in the reference hologram. Image domain JTC is used to match the images retrieved from the holograms. The images are recorded by a light addressed spatial light modulator (LASLM). Being recorded and retrieved, the images provides correlation peaks with special positions, with a strict dependence on the tested and reference holograms mutual shifts. We prove experimentally that the image domain recognizing provides as more effective usage of the LASLM work pupil and resolution as a less device size. The system also has a good tolerance to shift and rotation of the security holographic mark. Few correlation peaks respected to test holograms enhances the device recognizing probability. We provide computer simulations based on the mathematical analysis of the optical signal transforming. The real-time experimental results corresponded with computer simulations are presented.

  14. Optical Correlator for Face Recognition Using Collinear Holographic System

    NASA Astrophysics Data System (ADS)

    Watanabe, Eriko; Kodate, Kashiko

    2006-08-01

    We have constructed an optical correlator for fast face recognition. Recognition rate can be markedly improved, if reference images are optically recorded and can be accessed directly without converting them to digital signals. In addition, a large capacity of optical storage allows us to increase the size of the reference database. We propose a new optical correlator that integrates the optical correlation technology used in our face recognition system and collinear holography. From preliminary correlation experiments using the collinear optical set-up, we achieved excellent performance of high correlation peaks and low error rates. We expect an optical correlation of 10 μs/frame, i.e., 100,000 face/s when applied to face recognition. This system can also be applied to various image searches.

  15. In vivo simultaneous multispectral fluorescence imaging with spectral multiplexed volume holographic imaging system

    NASA Astrophysics Data System (ADS)

    Lv, Yanlu; Zhang, Jiulou; Zhang, Dong; Cai, Wenjuan; Chen, Nanguang; Luo, Jianwen

    2016-06-01

    A simultaneous multispectral fluorescence imaging system incorporating multiplexed volume holographic grating (VHG) is developed to acquire multispectral images of an object in one shot. With the multiplexed VHG, the imaging system can provide the distribution and spectral characteristics of multiple fluorophores in the scene. The implementation and performance of the simultaneous multispectral imaging system are presented. Further, the system's capability in simultaneously obtaining multispectral fluorescence measurements is demonstrated with in vivo experiments on a mouse. The demonstrated imaging system has the potential to obtain multispectral images fluorescence simultaneously.

  16. Performances of new green sensitive liquid photopolymers for volume phase holographic gratings

    NASA Astrophysics Data System (ADS)

    Zanutta, Alessio; Bianco, Andrea; Zerbi, Filippo M.

    2012-03-01

    Liquid photopolymers produced by Polygrama-Lynx (SM-532TR and SM-532TRF) have been studied to determine their performances in terms of refractive index modulation, transparency and overall optical quality. Volume phase holographic gratings (VPHGs) based on these materials have been obtained using a 532 DPSS laser and the grating efficiency has been measured at different angles and wavelengths. Using the Kogelnik model and/or the RCWA approach, the thickness and the refractive index modulation has been determined for gratings as function of light exposure, line density, etc. Index modulations up to 0.03 together with good optical quality were obtained.

  17. Volume holographic recording utilizing photo-initiated polymerization for nonvolatile digital data storage

    NASA Astrophysics Data System (ADS)

    Paraschis, Loukas

    Volume holographic recording offers an attractive solution for next generation digital storage with high density (>=10 Gb/cm 2) and transfer rate (Gb/sec). In holographic storage, data is recorded as volume phase gratings (refractive index modulation) in an optical medium. The system performance is practically determined by the physical characteristics of the recording medium. Photorefractive crystals, the most extensively investigated volumetric media, offer sensitive but typically volatile recording. Recent advancements in photo-polymerizable media have offered an attractive alternative for nonvolatile storage. This thesis evaluates the important physical properties of volume holographic recording in a photo-polymerizable material. Formation of permanent compositional volume phase gratings through monomer photopolymerization has offered a very sensitive recording mechanism, but limitations were also reported during and after exposure. The previous studies of photopolymerization recording response suggested reciprocity failure at high intensity (I), and large grating spacing (Λ). Grating formation was described through a photo-induced reaction diffusion model that ignores post- exposure polymerization, suggesting diffusion ( D) limited medium response to improve for longer, e.g. multipulse, recording schedules. In this thesis, the dynamics of grating formation are, for the first time, investigated extensively with respect to I, and Λ, in a material utilizing cationing-ring-opening polymerization (CROP Polaroid). Holographic recording is evaluated in standard (pretreated ULSH500) CROP samples for constant exposure energy (15mJ/cm 2), i.e. total number of photons, but for a wide range of different I (mW/cm2 - W/cm2), i.e. incident photon rates, and for a few Λ (μm), i.e. diffusion scales. CROP grating evolution is diffusion limited for recording with short (τ r) high I (>W/ cm2) pulses. Grating formation, however, is photo-initiated (rather than photo

  18. High-speed image matching with coaxial holographic optical correlator

    NASA Astrophysics Data System (ADS)

    Ikeda, Kanami; Watanabe, Eriko

    2016-09-01

    A computation speed of more than 100 Gbps is experimentally demonstrated using our developed ultrahigh-speed optical correlator. To verify this high computation speed practically, the computation speeds of our optical correlator and conventional digital image matching are quantitatively compared. We use a population count function that achieves the fastest calculation speed when calculating binary matching by a central processing unit (CPU). The calculation speed of the optical correlator is dramatically faster than that using a CPU (2.40 GHz × 4) and 16 GB of random access memory, especially when the calculation data are large-scale.

  19. Simultaneous multiplane imaging of human ovarian cancer by volume holographic imaging

    PubMed Central

    Orsinger, Gabriel V.; Watson, Jennifer M.; Gordon, Michael; Nymeyer, Ariel C.; de Leon, Erich E.; Brownlee, Johnathan W.; Hatch, Kenneth D.; Chambers, Setsuko K.; Barton, Jennifer K.; Kostuk, Raymond K.; Romanowski, Marek

    2014-01-01

    Abstract. Ovarian cancer is the most deadly gynecologic cancer, a fact which is attributable to poor early detection and survival once the disease has reached advanced stages. Intraoperative laparoscopic volume holographic imaging has the potential to provide simultaneous visualization of surface and subsurface structures in ovarian tissues for improved assessment of developing ovarian cancer. In this ex vivo ovarian tissue study, we assembled a benchtop volume holographic imaging system (VHIS) to characterize the microarchitecture of 78 normal and 40 abnormal tissue specimens derived from ovarian, fallopian tube, uterine, and peritoneal tissues, collected from 26 patients aged 22 to 73 undergoing bilateral salpingo-oophorectomy, hysterectomy with bilateral salpingo-oophorectomy, or abdominal cytoreductive surgery. All tissues were successfully imaged with the VHIS in both reflectance- and fluorescence-modes revealing morphological features which can be used to distinguish between normal, benign abnormalities, and cancerous tissues. We present the development and successful application of VHIS for imaging human ovarian tissue. Comparison of VHIS images with corresponding histopathology allowed for qualitatively distinguishing microstructural features unique to the studied tissue type and disease state. These results motivate the development of a laparoscopic VHIS for evaluating the surface and subsurface morphological alterations in ovarian cancer pathogenesis. PMID:24676382

  20. Optimization of multi-grating volume holographic spectrum splitters for photovoltaic applications.

    PubMed

    Ingersoll, G B; Leger, J R

    2016-07-10

    Recent research has shown that using multiple diverse-bandgap photovoltaic (PV) cells in conjunction with a spectrum splitting optical system can significantly improve PV power generation efficiency. Although volume Bragg gratings (VBGs) can serve as effective spectrum splitters, the inherent dispersion of a VBG can be detrimental given a broad-spectrum input. The performance of a single holographic spectrum splitter element can be improved by utilizing multiple single volume gratings, each operating in a slightly different spectral band. However, care must be taken to avoid inter-grating coupling effects that limit the ultimate performance. This work explores broadband two-grating holographic optical elements (HOEs) in multiplexed (single element) and sandwiched-grating arrangements. Particle swarm optimization is used to tailor these systems to the solar spectrum, taking into account both efficiency and dispersion. Both multiplexed and sandwiched two-grating systems exhibit performance improvements over single-grating solutions, especially when reduced dispersion is required. Under a ±2° constraint on output angular spread from wavelength dispersion, sandwiched-, multiplexed-, and single-grating systems exhibit power conversion efficiencies of 82.1%, 80.9%, and 77.5%, respectively, compared to an ideal bandpass spectrum splitter. Dispersion performance can be further improved by employing more than two VBGs in the spectrum splitter, but efficiency is compromised by additional cross-coupling effects. Multiplexed-grating systems are especially susceptible to these effects, but have the advantage of utilizing only a single HOE. PMID:27409317

  1. Dual-wavelength microarray fluorescence detection system using volume holographic filter.

    PubMed

    Fu, Dongxiang; Ma, Junshan; Chen, Jiabi

    2007-01-01

    A dual-wavelength microarray scanner based on laser confocal principle is constructed to acquire the laser-induced two-color fluorescence from dyes Cy3 and Cy5. Unlike most commercially available micoarray scanners whose lasers are continuous wave, filters are bandpass and the channels are multiple photomultiplier tubes (PMTs), the system mainly consists of two diode lasers, four volume holographic band-stop filters, and one PMT. The central wavelengths of two kinds of volume holographic band-stop filters are equal to those of the two laser, respectively. The fluorescence beams can pass through the filters, while laser beams are blocked by them because the filters are cut off. The two fluorescences can pass through a common optical path. Thus, only one pinhole and one PMT are required. The two fluorescences are acquired by the PMT with time sharing. The two respective fluorescences can be gathered when two diode lasers work asynchronously. If lasers work synchronously, the two wavelength fluorescences could be acquired simultaneously by the same PMT. A synthesis of a two-color fluorescence image can be realized straightforwardly in this manner. An experiment is conducted and Cy3 and Cy5 fluorescences are captured. Gridding of the fluorescent images based on basic morphological erosion appropriately locates the boundary between adjacent spots. PMID:17343515

  2. Generation of individually modulated femtosecond pulse string by multilayer volume holographic gratings.

    PubMed

    Yan, Xiaona; Gao, Lirun; Yang, Xihua; Dai, Ye; Chen, Yuanyuan; Ma, Guohong

    2014-10-20

    A scheme to generate individually modulated femtosecond pulse string by multilayer volume holographic grating (MVHG) is proposed. Based on Kogelnik's coupled-wave theory and matrix optics, temporal and spectral expressions of diffracted field are given when a femtosecond pulse is diffracted by a MVHG. It is shown that the number of diffracted sub-pulses in the pulse string equals to the number of grating layers of the MVHG, peak intensity and duration of each diffracted sub-pulse depend on thickness of the corresponding grating layer, whereas pulse interval between adjacent sub-pulses is related to thickness of the corresponding buffer layer. Thus by modulating parameters of the MVHG, individually modulated femtosecond pulse string can be acquired. Based on Bragg selectivity of the volume grating and phase shift provided by the buffer layers, we give an explanation on these phenomena. The result is useful to design MVHG-based devices employed in optical communications, pulse shaping and processing. PMID:25401645

  3. Characterization of volume holographic optical elements recorded in Bayfol HX photopolymer for solar photovoltaic applications.

    PubMed

    Marín-Sáez, Julia; Atencia, Jesús; Chemisana, Daniel; Collados, María-Victoria

    2016-03-21

    Volume Holographic Optical Elements (HOEs) present interesting characteristics for photovoltaic applications as they can select spectrum for concentrating the target bandwidth and avoiding non-desired wavelengths, which can cause the decrease of the performance on the cell, for instance by overheating it. Volume HOEs have been recorded on Bayfol HX photopolymer to test the suitability of this material for solar concentrating photovoltaic systems. The HOEs were recorded at 532 nm and provided a dynamic range, reaching close to 100% efficiency at 800 nm. The diffracted spectrum had a FWHM of 230 nm when illuminating at Bragg angle. These characteristics prove HOEs recorded on Bayfol HX photopolymer are suitable for concentrating solar light onto photovoltaic cells sensitive to that wavelength range. PMID:27136889

  4. Quasinormal modes and holographic correlators in a crunching AdS geometry

    NASA Astrophysics Data System (ADS)

    Kumar, S. Prem; Vaganov, Vladislav

    2016-02-01

    We calculate frequency space holographic correlators in an asymptotically AdS crunching background, dual to a relevant deformation of the M2-brane CFT placed in de Sitter spacetime. For massless bulk scalars, exploiting the connection to a solvable supersymmetric quantum mechanical problem, we obtain the exact frequency space correlator for the dual operator in the deformed CFT. Controlling the shape of the crunching surface in the Penrose diagram by smoothly dialling the deformation from zero to infinity, we observe that in the large deformation limit the Penrose diagram becomes a `square', and the exact holographic correlators display striking similarities to their counterparts in the BTZ black hole and its higher dimensional generalisations. We numerically determine quasinormal poles for relevant and irrelevant operators, and find an intricate pattern of these in the complex frequency plane. In the case of relevant operators, the deformation parameter has an infinite sequence of critical values, each one characterised by a pair of poles colliding and moving away from the imaginary frequency axis with increasing deformation. In the limit of infinite deformation all scalar operators have identical quasinormal spectra. We compare and contrast our strongly coupled de Sitter QFT results with strongly coupled thermal correlators from AdS black holes.

  5. Holographic particle image velocimetry: a comparison of digital shearing and 3D correlation analysis methods

    NASA Astrophysics Data System (ADS)

    Yang, Hui; Alcock, Rob D.; Halliwell, Neil A.; Coupland, Jeremy M.

    2003-11-01

    In the past, the use of optical and digital three-dimensional correlation methods have been demonstrated to extract velocity data from the complex amplitude distribution of particle images in holographic particle image velocimetry (HPIV). Recently we have proposed a digital shearing method to extract three-component particle displacement data throughout a complete image field. In contrast to full three-dimensional correlation, it has been shown that all three components of particle image displacement can be retrieved using just four two-dimensional fast Fourier transform (FFT) operations and appropriate coordinate transformations. In this paper we describe three-dimensional correlation and digital shearing methods and compare their performance in terms of computational efficiency and measurement accuracy. The simulated results show that the digital shearing method has comparable accuracy to three-dimensional correlation but is significantly faster.

  6. Recording of incoherent reflective volume Fourier holograms for optical correlators

    NASA Astrophysics Data System (ADS)

    Rodin, Vladislav G.; Starikov, Sergey N.

    2007-01-01

    The scheme of recording of reflective volume Fourier holograms in monochromatic light with partial spatial coherence is presented. The scheme contains posed on one optical axis an illuminated or self-luminous object, Fourier-objective, photosensitive medium and concave mirror. The light is proposed to be monochromatic with partial spatial coherence. The object is located in a front focal plane of the Fourier-objective. Photosensitive medium is placed in a back focal plane of the Fourier-objective, and the mirror is posed on a double focal length of the mirror from photosensitive medium. The light from input object is focused by the Fourier-objective in a volume of photosensitive medium, shaping a far field diffraction pattern of input object. This pattern is partial coherent analog of Fourier transform of input object. The light transmitted through the medium falls on the concave mirror and is reflected back, thus the mirror shapes the second copy of far field diffraction pattern of input object in the volume of photosensitive medium. Thus, these two light waves, propagating in the opposite directions, form the interference pattern in photosensitive medium, and a reflective volume Fourier hologram is recorded by monochromatic light with partial spatial coherence. The experiments on recording of these holograms and image reconstruction were realized. Patent by Russian Federation No2176099 on the device of recording of reflective volume holographic Fourier-filter in light with partial spatial coherence was taken out. Described reflective volume Fourier-holograms can be used in optical correlators as the spatial filters and spectral selectors at image recognition both in monochromatic and polychromatic light.

  7. Performance of volume phase holographic transmission grating recorded in DCG for PGP

    NASA Astrophysics Data System (ADS)

    Li, Ming; Tang, Minxue; Xia, Haohan; Fang, Chunhuan; Wu, Jianhong; Zhao, Xunjie

    2010-11-01

    The volume phase holographic (VPH) transmission grating recorded in dichromate gelatin (DCG) with a specific spectral coverage from 420 nm to 760 nm is designed for a novel prism-grating-prism imaging spectrometer. Based on the Rigorous Coupled-Wave Analysis, its performances are predicted and analyzed. The grating is manufactured and its properties are measured experimentally. The diffraction efficiency over the spectral range, the bandwidth, and the angular selectivity of the grating is measured, analyzed and compared with that of the theoretical ones. The results show that by adjusting and controlling the preparation conditions of DCG plates, the exposure time and the post-processing technique of the grating, the VPH transmission grating with high diffraction efficiency approximate to the design requirement can be obtained. The measured peak diffraction efficiency reaches nearly 85% at central wavelength of 590 nm while the average diffraction efficiency is larger than 75% over the required spectral range from 420 nm to 760 nm.

  8. Volume phase holographic grating performance on the VIRUS-P instrument

    NASA Astrophysics Data System (ADS)

    Adams, Joshua J.; Hill, Gary J.; MacQueen, Phillip J.

    2008-07-01

    The Visible Integral-field Replicable Unit Spectrograph Prototype (VIRUS-P) has been in operation on the Harlan J Smith 2.7m Telescope at McDonald Observatory since October of 2006. The prototype was created to test the design and science capabilities of the full VIRUS instrument, wherein 150 copies of the spectrograph will be installed on the Hobby Eberly Telescope (HET). We here discuss the specialized test bench built to assess the blue optimized Volume Phase Holographic (VPH) grating performance. We also give lab and on-telescope efficiency measurements for three such gratings in the wavelength range 3400-6800Å. Two sources of stray light relevant to most spectrograph designs are also discussed.

  9. Reduction of blurring in broadband volume holographic imaging using a deconvolution method

    PubMed Central

    Lv, Yanlu; Zhang, Xuanxuan; Zhang, Dong; Zhang, Lin; Luo, Yuan; Luo, Jianwen

    2016-01-01

    Volume holographic imaging (VHI) is a promising biomedical imaging tool that can simultaneously provide multi-depth or multispectral information. When a VHI system is probed with a broadband source, the intensity spreads in the horizontal direction, causing degradation of the image contrast. We theoretically analyzed the reason of the horizontal intensity spread, and the analysis was validated by the simulation and experimental results of the broadband impulse response of the VHI system. We proposed a deconvolution method to reduce the horizontal intensity spread and increase the image contrast. Imaging experiments with three different objects, including bright field illuminated USAF test target and lung tissue specimen and fluorescent beads, were carried out to test the performance of the proposed method. The results demonstrated that the proposed method can significantly improve the horizontal contrast of the image acquire by broadband VHI system. PMID:27570703

  10. Reduction of blurring in broadband volume holographic imaging using a deconvolution method.

    PubMed

    Lv, Yanlu; Zhang, Xuanxuan; Zhang, Dong; Zhang, Lin; Luo, Yuan; Luo, Jianwen

    2016-08-01

    Volume holographic imaging (VHI) is a promising biomedical imaging tool that can simultaneously provide multi-depth or multispectral information. When a VHI system is probed with a broadband source, the intensity spreads in the horizontal direction, causing degradation of the image contrast. We theoretically analyzed the reason of the horizontal intensity spread, and the analysis was validated by the simulation and experimental results of the broadband impulse response of the VHI system. We proposed a deconvolution method to reduce the horizontal intensity spread and increase the image contrast. Imaging experiments with three different objects, including bright field illuminated USAF test target and lung tissue specimen and fluorescent beads, were carried out to test the performance of the proposed method. The results demonstrated that the proposed method can significantly improve the horizontal contrast of the image acquire by broadband VHI system. PMID:27570703

  11. Fiber-optic wavelength-division multiplexing and demultiplexing using volume holographic gratings

    SciTech Connect

    Moslehi, B.; Harvey, P.; Ng, J.; Jannson, T. )

    1989-10-01

    We present theoretical and experimental results of a novel fiber-optic wavelength-division multiplexing (WDM) design employing a broadband (>150-nm) dichromated gelatin volume holographic grating operating in a reflective Littrow configuration with on-axis optics, a single lens, and one fiber array. This configuration can achieve better than {minus}1.5-dB insertion loss and {minus}40-dB cross talk for a 6-channel system and {minus}2.5-dB insertion loss and {minus}20-dB cross talk for a 12-channel system with 15-nm channel spacing. For an experimental 4-channel WDM unit we measured better than {minus}1.5-dB insertion loss for all channels and less than {minus}32-dB cross talk. This design can provide cost and performance benefits for local area network communication applications.

  12. Holographic recording in acrylamide photopolymers: thickness limitations.

    PubMed

    Mahmud, Mohammad Sultan; Naydenova, Izabela; Pandey, Nitesh; Babeva, Tzwetanka; Jallapuram, Raghavendra; Martin, Suzanne; Toal, Vincent

    2009-05-10

    Holographic recording in thick photopolymer layers is important for application in holographic data storage, volume holographic filters, and correlators. Here, we studied the characteristics of acrylamide-based photopolymer layers ranging in thickness from 250 microm to 1 mm. For each thickness, samples with three different values of absorbance were studied. By measuring the diffraction efficiency growth of holographically recorded gratings and studying the diffraction patterns obtained, the influence of scattering on the diffraction efficiency of thick volume holographic gratings was analyzed. It was found that, above a particular thickness and absorbance, the diffraction efficiency significantly decreased because of increased holographic scattering. From the diffraction efficiency dependence on absorbance and thickness it is possible to choose photopolymer layer properties that are suitable for a particular holographic application. This study was carried out to determine the highest layer thickness that could be used for phase code multiplexed holographic data storage utilizing thick photopolymer layers as a recording medium. Based on our studies to date we believe that the layer to be used for phase coded reference beam recording with 0.1 absorbance at 532 nm can have a thickness up to 450 microm. The potential use of thicker layers characterized by low scattering losses is part of our continuing research. PMID:19424384

  13. Optical properties of beam-steering elements utilizing volume holographic gratings

    NASA Astrophysics Data System (ADS)

    Butler, James Jay

    2000-06-01

    An optical beam steering element is a device that is used to control the direction in which a beam of light travels. We have investigated the optical properties of two classes of optical beam steering elements. The first type utilized the polarization dependence of the diffraction efficiency of volume holographic gratings. The second type utilized the fact that the diffraction efficiency of holograms imbibed with a nematic liquid crystal can be controlled by the application of an electric field. In both cases, elements with excellent switching contrasts were fabricated for operation in the visible and near infrared wavelength range including the commonly used telecommunications wavelength of 1.3μm. The holographic recording material that we have used is Polaroid Corporation's DMP-128 photopolymer. This material is porous after exposure and processing, a feature useful in two ways for this work. First, volume gratings with very large refractive index modulations, on the order of 0.2, can be fabricated using this material. Secondly, the pores can be filled with a nematic liquid crystal, resulting in electrically-switchable gratings. In our analysis of polarization-sensitive gratings we have employed several coupled wave theories, each with a different set of approximations. We have found that rigorous coupled wave theory must be used in predicting the diffractive properties of highly modulated volume gratings, where the effects of higher diffraction orders and form birefringence become important. In our analysis of the optical properties of electrically-switchable liquid crystal composite holograms, we have employed a theoretical analysis that treats the birefringent nature of the gratings. The results of Kogelnik theory that neglects the grating anisotropy, a two-wave theory that treats anisotropy, and a formulation of rigorous coupled wave theory that includes anisotropy were compared. We found it was necessary to include the effects of optical anisotropy to

  14. Design and manufacture of transmission volume phase holographic grating used in VIS/NIR wave band

    NASA Astrophysics Data System (ADS)

    Fang, Chunhuan; Tang, Minxue; Wu, Jianhong

    2011-11-01

    Due to its uniform dispersion and higher diffraction efficiency, transmission volume phase holographic grating (VPHG) has been widely used for astronomical spectroscopy, ultrafast lasers compressors and wavelength division multiplexers. According to its application requirement and based on the Rigorous Coupled Wave Analysis (RCWA), a transmission VPHG with a frequency of 196lp/mm is designed and manufactured in this paper. The thickness of gelatin and the modulation of refraction index are optimized for high diffraction efficiency over a wavelength range from 420nm to 1000nm. The grating was recorded in dichromate gelatin (DCG) and in a symmetrical light path. By controlling the coating, exposure and post-processing conditions, the thickness of gelatin and the modulation of refraction index can be adjusted. The diffraction efficiency varied within the required wave band and the polarization property of the illumination wave were measured and compared with that of the theoretical ones. From the results, it can be seen that by adjusting and controlling the preparation conditions of DCG plates, the exposure value and post-processing technique, the peak diffraction efficiency of VPHG reaches to 47% and the average diffraction efficiency is above 35% in the spectral coverage, which is close to the theoretical values. This transmission VPHG can be applied in a prism-grating-prism (PGP) imaging spectrometer.

  15. New GRISMs for AFOSC based on volume phase holographic gratings in photopolymers

    NASA Astrophysics Data System (ADS)

    Zanutta, Alessio; Bianco, Andrea; Landoni, Marco; Tomasella, Lina; Benetti, Stefano; Giro, Enrico

    2014-07-01

    Volume Phase Holographic Gratings (VPHG) can provide an improvement of diffraction efficiency and function- ality in already available astronomical instrumentation. Here, we present the design, manufacturing and testing of two GRISMs mounted on the AFOSC camera (at the 1.8 m Asiago telescope) based on VPHGs. Such diffrac- tion gratings have been written on a new solid and green sensitive photopolymer material produced by Bayer MaterialScience AG that show interesting performances (refractive index modulation, homogeneity, stability). The GRISMs have been designed according to the specific requests of astronomers. One GRISM consists in a very low dispersion VPHG (285 l/mm) that covers the range 500 - 1000 nm and suitable for observations of supernovae. The second one is a 600 l/mm VPHG for the Ha region. Both gratings show peak efficiency close to 90% and same diffraction efficiency is shown by the corresponding GRISMs. This high device's performances means that the coupling losses are very low, also thanks to the matching of the refractive index between sub- strates and prisms. Some observations have been finally carried out and the gain in terms of efficiency and signal to noise ratio have been calculated in order to compare the photopolymeric VPHGs with the classic GRISMs already mounted and used in the AFOSC spectrometer.

  16. The transmission volume-phase holographic grating recorded on dichromated gelatin film used in Raman spectrometer

    NASA Astrophysics Data System (ADS)

    Mei, Qijing; Liu, Peng; Tang, Minxue

    2015-11-01

    With the intrinsic advantages of high diffraction efficiency, signal to noise ratio, wavelength and angular selectivity, and low scattering and absorption, volume phase holographic grating (VPHG) has been widely used for spectroscopy, telecommunications, astronomy and ultra-fast laser sciences. The transmission VPHG combined with on-axis imaging lenses can be used in the Raman spectroscopic imaging, which enables a spectrometer to work at high resolution over a wide field of view, and compresses the configuration to achieve very little vignetting. The subject of this paper is to design a kind of transmission VPHG used in Raman Spectrometer with high diffraction efficiency theoretically. According to the Bragg condition and the coupled wave theory, the diffraction efficiency of transmission VPHG recorded on dichromated gelatin (DCG) has been optimized by using G-solver software, which is applicable to the visible waveband ranging from 0.46μm to 0.70μm. The effects of the recording and reconstruction setup parameters, the amplitude of the index modulation (Δn) and the thickness of the gelatin layer (d), and the polarization state of reconstruction beams on the diffraction efficiency properties of the gratings are analyzed at the same time.

  17. A new kind of storage hierarchy: volume holographic universal storage cache

    NASA Astrophysics Data System (ADS)

    Luo, Dongjian; Xie, Changsheng; Han, Dezhi; Huang, Jianzhong; Zhang, Chengfeng

    2006-01-01

    The access time of Disk/RAID has not been improved as fast as the memory performance whose rate of improvement has been 25% per year and hence the disk access penalty is considerably increasing with each enhancement in the memory architecture. To solve the problem, a new kind of storage hierarchy, Volume Holographic Universal Storage Cache (short for VHUSC) is proposed. VHUSC acts as a layer between main memory and disk or disk array. VHUSC can lower the disk access latency, provide much higher I/O bandwidth and throughput, it thus greatly improve the I/O performance of computer system. In this paper, an application independent model based on queuing theory is proposed for the VHUSC performance evaluation. Based on this model, VHUSC and traditional disk/RAID performance is analyzed and compared. Result shows that in most cases VHUSC can improve the disk read/write performance by 1 order of magnitude, especially when the hit rate is larger than 99%, the performance can reach 2 orders of magnitude.

  18. Volume holographic gratings as optical sensor for heavy metal in bathing waters

    NASA Astrophysics Data System (ADS)

    Bianco, G.; Ferrara, M. A.; Borbone, F.; Zuppardi, F.; Roviello, A.; Striano, V.; Coppola, G.

    2015-05-01

    Sensor holograms utilize the diffraction principle of transmitting volume holographic grating (VHG) recorded within a photopolymer appositely functionalized to detect a specific stimulus or analyte. A change in the swelling or shrinking state or cross-linking density of the polymer can be caused by the hologram interaction with an analyte. This leads to a change in the recorded hologram sensor and thus, considering an incident monochromatic light and the VHG angular selectivity, to an angle shift of the diffracted maximum intensity. In this work, two new photopolymers based on a sol-gel matrix opportunely functionalized to be sensitive to transition metals or heavy metals were used as sensitive material to record VHGs. An interferometric set up with a laser source at 532nm was used to record VHGs and gratings of 1000 lines/mm were realized. When exposed to a solution of water and lead, an angle shift of about 3° of the first order diffraction of the grating was measured, demonstrating its capability to reveal the presence of heavy metal in water.

  19. Design of optical system for spectrometer involving a volume phase holographic transmission grating

    NASA Astrophysics Data System (ADS)

    Ren, Zhong; Liu, Guodong; Huang, Zhen

    2014-08-01

    At present, spectrometer has popularly being used into varieties of fields including environment, food, medical health monitoring and metal industry because it has the advantages of noninvasive, high efficient and convenient etc. The performance of the spectrometer is determined by its optical system. Normally, according to the apparatus and principle of splitting-light, optical system of spectrometer can be classified into several categories, for example, filter-typed, dispersion typed, Fourier transform typed and acousto-optic tunable typed. The grating typed optical system has been popularly used into the spectrometer due to the features of higher diffraction efficiency, resolution and dispersion rate etc. In the grating-typed optical system, although the traditional plane and concave grating have usually been used into some spectrometers, some disadvantages of them still limit their applications, such as, large aberration, worse spectral flatness and low deficiency, etc. In this paper, to overcome these disadvantages of the traditional plane and concave grating, a novel optical system for spectrometer (OSS) based on volume phase holographic transmission (VPHT) grating was designed. For this novel grating, its manufacture and theories were investigated, and its diffraction efficiency was firstly numerically simulated according to different parameters. In order to prove the feasibility of this designed OSS, the spectral calibration experiment was performed and the spectral resolution reached 2nm.

  20. Holographic view on quantum correlations and mutual information between disjoint blocks of a quantum critical system

    NASA Astrophysics Data System (ADS)

    Molina-Vilaplana, Javier; Sodano, Pasquale

    2011-10-01

    In ( d + 1) dimensional Multiscale Entanglement Renormalization Ansatz (MERA) networks, tensors are connected so as to reproduce the discrete, ( d + 2) holographic geometry of Anti de Sitter space (AdS d+2) with the original system lying at the boundary. We analyze the MERA renormalization flow that arises when computing the quantum correlations between two disjoint blocks of a quantum critical system, to show that the structure of the causal cones characteristic of MERA, requires a transition between two different regimes attainable by changing the ratio between the size and the separation of the two disjoint blocks. We argue that this transition in the MERA causal developments of the blocks may be easily accounted by an AdS d+2 black hole geometry when the mutual information is computed using the Ryu-Takayanagi formula. As an explicit example, we use a BTZ AdS3 black hole to compute the MI and the quantum correlations between two disjoint intervals of a one dimensional boundary critical system. Our results for this low dimensional system not only show the existence of a phase transition emerging when the conformal four point ratio reaches a critical value but also provide an intuitive entropic argument accounting for the source of this instability. We discuss the robustness of this transition when finite temperature and finite size effects are taken into account.

  1. From the surface to volume: concepts for the next generation of optical-holographic data-storage materials.

    PubMed

    Bruder, Friedrich-Karl; Hagen, Rainer; Rölle, Thomas; Weiser, Marc-Stephan; Fäcke, Thomas

    2011-05-01

    Optical data storage has had a major impact on daily life since its introduction to the market in 1982. Compact discs (CDs), digital versatile discs (DVDs), and Blu-ray discs (BDs) are universal data-storage formats with the advantage that the reading and writing of the digital data does not require contact and is therefore wear-free. These formats allow convenient and fast data access, high transfer rates, and electricity-free data storage with low overall archiving costs. The driving force for development in this area is the constant need for increased data-storage capacity and transfer rate. The use of holographic principles for optical data storage is an elegant way to increase the storage capacity and the transfer rate, because by this technique the data can be stored in the volume of the storage material and, moreover, it can be optically processed in parallel. This Review describes the fundamental requirements for holographic data-storage materials and compares the general concepts for the materials used. An overview of the performance of current read-write devices shows how far holographic data storage has already been developed. PMID:21538730

  2. Storage density estimation for the phase-encoding and shift multiplexing holographic optical correlator

    NASA Astrophysics Data System (ADS)

    Zheng, Tianxiang; Cao, Liangcai; He, Qingsheng; Jin, Guofan

    2013-09-01

    Holographic optical correlator (HOC) is applicable in occasion where the instant search throughout a huge database is demanded. The primary advantage of the HOC is its inherent parallel processing ability and large storage capacity. The HOC's searching speed is proportional to the storage density. This paper proposes a phase-encoding method in the object beam to increase the storage density. A random phase plate (RPP) is used to encode the phase of the object beam before uploading the data pages to the object beam. By shifting the RPP at a designed interval, the object beam is modulated into an orthogonal object beam to the previous one and a new group of database can be stored. Experimental results verify the proposed method. The maximum storage number of the data pages with a RPP at a fixed position can be as large as 7,500. The crosstalk among different groups of the databases can be unnoticeable. The increase in the storage density of the HOC depends on the number of the orthogonal positions from the different portions of a same RPP.

  3. High-speed Reed-Solomon decoder using reformulation inversionless Berlekamp-Massey architecture for volume holographic storage

    NASA Astrophysics Data System (ADS)

    Hu, Diqing; Xie, Changsheng

    2003-04-01

    Volume holography is currently the subject of widespread interest as a fast-readout-rate, high-capacity digital data-storage technology. However, due to the effect of cross-talk noise, scattering noise, noise gratings formed during a multiple exposure schedule, it brings a lot of burst errors and random errors in the system. Reed-Solomon error-correction codes have been widely used to defend digital data against errors, but the speed of Reed-Solomon decoder for volume holographic storage system application is a challenge. This paper presents a high-speed VLSI decoder architecture implementation for decoding (255,223) Reed-Solomon codes with the Modified Berlekamp-Massey algorithm for volume holographic storage. In contrast to conventional Berlekamp-Massey architectures, the speed bottleneck is eliminated via a series of algorithmic transformations that result in a fully systolic architecture in which a single array of processors computes both the error-locator and the error-evaluator polynomials. The proposed architecture requirs approximately 25% fewer multipliers and a simpler control structure than the architectures based on the popular extended Euclidean algorithm. By adopting high speed CPLD, a data processing rate over 200 Mbit/s is realized. Moreover, for block-interleaved Reed-Solomon codes, embedding the interleaver memory into the decoder results in a further increase of the throughput.

  4. Optical memory development. Volume 2: Gain-assisted holographic storage media

    NASA Technical Reports Server (NTRS)

    Gange, R. A.; Mezrich, R. S.

    1972-01-01

    Thin deformable films were investigated for use as the storage medium in a holographic optical memory. The research was directed toward solving the problems of material fatigue, selective heat addressing, electrical charging of the film surface and charge patterning by light. A number of solutions to these problems were found but the main conclusion to be drawn from the work is that deformable media which employ heat in the recording process are not satisfactory for use in a high-speed random-access read/write holographic memory. They are, however, a viable approach in applications where either high speed or random-access is not required.

  5. Conically Scanned Holographic LIDAR Telescope

    NASA Technical Reports Server (NTRS)

    Schwemmer, Geary

    1993-01-01

    Holographic LIDAR telescope includes holographic disk, rotation of which sweeps collimated, monochromatic beam of light from laser through conical scan. Holographic disk diffracts light scattered back from target volume or area to focal point located at stationary photomultiplier detector. Two conical baffles prevent stray light from reaching detector.

  6. Time-sequential autostereoscopic 3-D display with a novel directional backlight system based on volume-holographic optical elements.

    PubMed

    Hwang, Yong Seok; Bruder, Friedrich-Karl; Fäcke, Thomas; Kim, Seung-Cheol; Walze, Günther; Hagen, Rainer; Kim, Eun-Soo

    2014-04-21

    A novel directional backlight system based on volume-holographic optical elements (VHOEs) is demonstrated for time-sequential autostereoscopic three-dimensional (3-D) flat-panel displays. Here, VHOEs are employed to control the direction of light for a time-multiplexed display for each of the left and the right view. Those VHOEs are fabricated by recording interference patterns between collimated reference beams and diverging object beams for each of the left and right eyes on the volume holographic recording material. For this, self-developing photopolymer films (Bayfol® HX) were used, since those simplify the manufacturing process of VHOEs substantially. Here, the directional lights are similar to the collimated reference beams that were used to record the VHOEs and create two diffracted beams similar to the object beams used for recording the VHOEs. Then, those diffracted beams read the left and right images alternately shown on the LCD panel and form two converging viewing zones in front of the user's eyes. By this he can perceive the 3-D image. Theoretical predictions and experimental results are presented and the performance of the developed prototype is shown. PMID:24787867

  7. Three-dimensional digital holographic aperture synthesis for rapid and highly-accurate large-volume metrology

    NASA Astrophysics Data System (ADS)

    Crouch, Stephen; Kaylor, Brant M.; Barber, Zeb W.; Reibel, Randy R.

    2015-09-01

    Currently large volume, high accuracy three-dimensional (3D) metrology is dominated by laser trackers, which typically utilize a laser scanner and cooperative reflector to estimate points on a given surface. The dependency upon the placement of cooperative targets dramatically inhibits the speed at which metrology can be conducted. To increase speed, laser scanners or structured illumination systems can be used directly on the surface of interest. Both approaches are restricted in their axial and lateral resolution at longer stand-off distances due to the diffraction limit of the optics used. Holographic aperture ladar (HAL) and synthetic aperture ladar (SAL) can enhance the lateral resolution of an imaging system by synthesizing much larger apertures by digitally combining measurements from multiple smaller apertures. Both of these approaches only produce two-dimensional imagery and are therefore not suitable for large volume 3D metrology. We combined the SAL and HAL approaches to create a swept frequency digital holographic 3D imaging system that provides rapid measurement speed for surface coverage with unprecedented axial and lateral resolution at longer standoff ranges. The technique yields a "data cube" of Fourier domain data, which can be processed with a 3D Fourier transform to reveal a 3D estimate of the surface. In this paper, we provide the theoretical background for the technique and show experimental results based on an ultra-wideband frequency modulated continuous wave (FMCW) chirped heterodyne ranging system showing ~100 micron lateral and axial precisions at >2 m standoff distances.

  8. Study on very high speed Reed-Solomon decoders using modified euclidean algorithm for volume holographic storage

    NASA Astrophysics Data System (ADS)

    Wu, Fei; Xie, Changsheng; Liu, ZhaoBin

    2003-04-01

    Volume holography is currently the subject of widespread interest as a fast-readout-rate, high-capacity digital data-storage technology. However, due to the effect of cross-talk noise, scattering noise, noise gratings formed during a multiple exposure schedule, it brings a lot of burst errors and random errors in the system. Reed-Solomon error-correction codes have been widely used to protect digital data against errors. This paper presents VLSI implementations of an 16 errors correcting (255,223) Reed-Solomon decoder architecture for volume holographic storage. We describe the Reed-Solomon decoders using modified Euclidean algorithms which are regular and simple, and naturally suitable for VLSI implementations. We design the speedily multiplication for GF(28) and pipeline structure to solve hardware complexity and high data processing rate for the Reed-Solomon decoders. We adopt high speed FPGA and have a data processing rate of 200 Mbit/s.

  9. Diffractive optics with high Bragg selectivity: volume holographic optical elements in Bayfol® HX photopolymer film

    NASA Astrophysics Data System (ADS)

    Bruder, Friedrich-Karl; Fäcke, Thomas; Hagen, Rainer; Hönel, Dennis; Orselli, Enrico; Rewitz, Christian; Rölle, Thomas; Walze, Günther

    2015-09-01

    For a long time volume Holographic Optical Elements (vHOE) have been discussed as an alternative, but were hampered by a lack of suitable materials. They provide several benefits over surface corrugated diffractive optical element like high diffraction efficiency due to their ability to reconstruct a single diffraction order, freedom of optical design by freely setting the replay angles and adjusting their bandwidth by a selection of the vHOE's thickness. Additional interesting features are related to their high Bragg selectivity providing transparent films for off-Bragg illumination. In this paper we report on our newly developed photopolymer film technology (Bayfol® HX) that uniquely requires no post processing after holographic exposure. We explain the governing non-local polymerization driven diffusion process leading to an active mass transport triggered by constructive interference. Key aspects of the recording process and their impact on index modulation formation is discussed. The influence on photopolymer film thickness on the bandwidth is shown. A comparison between coupled wave theory (CWT) simulation and experimental results is given. There are two basic recording geometries: reflection and transmission vHOEs. We explain consequences of how to record them properly and discuss in more detail the special challenges in transmission hologram recording. Here beam ratio and customization of photopolymer film properties can be applied most beneficially to achieve highest diffraction efficiency.

  10. Volume holographic recording in photopolymerizable nanocomposite materials based on radical-mediated thiol-yne step-growth polymerizations

    NASA Astrophysics Data System (ADS)

    Mitsube, Ken; Nishimura, Yuki; Takayama, Shingo; Nagaya, Kohta; Tomita, Yasuo

    2013-05-01

    We propose the use of radical-mediated thiol-yne step-growth photopolymerizations for volume holographic recording in NPC films to overcome the drawback of low crosslinking densities but retain the advantage of low shrinkage in the thiol-ene photopolymerizations. The thiol-yne photopolymerization mechanism is different from the thiol-ene photopolymeriztions in the sense that each alkyne functional group can react consecutively with two thiol functional groups. We show that thiol-yne based NPC films dispersed with silica nanoparticles give the saturated refractive index change as large as 0.008 and the material recording sensitivity as high as 2005 cm/J at a wavelength of 532 nm, larger than the minimum acceptable values of 0.005 and 500 cm/J, respectively, for holographic data storage. We also show that the shrinkage of a recorded hologram can be as low as that of thiol-ene based NPC films and that the thermal stability is improved better. In addition, we demonstrate digital data page recording in thiol-yne based NPC films, showing a low symbol error rate and a high signal-to-noise ratio to be 2.8×10-4 and 8, respectively.

  11. Optimisation of a Stirred Bioreactor through the Use of a Novel Holographic Correlation Velocimetry Flow Measurement Technique

    PubMed Central

    Ismadi, Mohd-Zulhilmi; Higgins, Simon; Samarage, Chaminda R.; Paganin, David; Hourigan, Kerry; Fouras, Andreas

    2013-01-01

    We describe a method for measuring three dimensional (3D) velocity fields of a fluid at high speed, by combining a correlation-based approach with in-line holography. While this method utilizes tracer particles contained within the flow, our method does not require the holographic reconstruction of 3D images. The direct flow reconstruction approach developed here allows for measurements at seeding densities in excess of the allowable levels for techniques based on image or particle reconstruction, thus making it suited for biological flow measurement, such as the flow in bioreactor. We outline the theory behind our method, which we term Holographic Correlation Velocimetry (HCV), and subsequently apply it to both synthetic and laboratory data. Moreover, because the system is based on in-line holography, it is very efficient with regard to the use of light, as it does not rely on side scattering. This efficiency could be utilized to create a very high quality system at a modest cost. Alternatively, this efficiency makes the system appropriate for high-speed flows and low exposure times, which is essential for imaging dynamic systems. PMID:23776534

  12. Physical properties of volume holographic recording utilizing photo-initiated polymerization for nonvolatile digital data storage

    NASA Astrophysics Data System (ADS)

    Paraschis, Loukas; Sugiyama, Yasuyuki; Hesselink, Lambertus

    1999-11-01

    The physical properties of photopolymer grating formation are, for the first time, investigated elaborately with respect to I, and (Lambda) . The dynamics of holographic recording with constant exposure energy (15mJ/cm2), are evaluated for a wide range of different I (mW/cm2 - W/cm2), and for a few typical (Lambda) (0.5 - 3.5 micrometer), in a material utilizing cationing-ring-opening polymerization (Polaroid CROP ULSH-500B). Diffusion was evaluated to limit the photo- initiated recording sensitivity at high I(greater than W/cm2 approximately (Lambda) -2). At the same time, however, the significant post-exposure grating development observed for diffusion limited recordings, was identified to allow eventually for equally high sensitive final gratings (approximately 3 - 5 cm/mJ) without reciprocity, or diffusion limitations. Based on these observations, a new physical model was developed that describes more accurately holographic recording utilizing photo-initiated polymerization, and accounts successfully for the observed physical properties of grating formation.

  13. Correlations estimate volume distilled using gravity, boiling point

    SciTech Connect

    Moreno, A.; Consuelo Perez de Alba, M. del; Manriquez, L.; Guardia Mendoz, P. de la

    1995-10-23

    Mathematical nd graphic correlations have been developed for estimating cumulative volume distilled as a function of crude API gravity and true boiling point (TBP). The correlations can be used for crudes with gravities of 21--34{degree} API and boiling points of 150--540 C. In distillation predictions for several mexican and Iraqi crude oils, the correlations have exhibited accuracy comparable to that of laboratory measurements. The paper discusses the need for such a correlation and the testing of the correlation.

  14. Application of a volume holographic grating in a CaF2 crystal for measuring linear displacements with nanoscale accuracy

    NASA Astrophysics Data System (ADS)

    Shcheulin, A. S.; Angervaks, A. E.; Kupchikov, A. K.; Verkhovskii, E. B.; Ryskin, A. I.

    2014-12-01

    A holographic method for measuring linear displacements based on the use of a highly stable volume scale hologram recorded in an additively colored calcium fluoride crystal with photochromic color centers is proposed and experimentally approved. The essence of this method lies in measuring and analyzing harmonic signals formed during linear displacement of crystal with a volume hologram in an external interference field. A physical model of the formation of harmonic signals in photodetectors when measuring displacements is considered, and a mathematical method for calculating linear displacements by plotting a Lissajous figure is substantiated. A laboratory breadboard of a device for measuring linear displacements in a range of 10 mm, limited by the aperture of crystal with a recorded 8.7-mm-thick hologram, is designed. When using a scale hologram with a period of 2.18 μm and a 632.8-nm He-Ne laser for reading this hologram, the error in measuring displacements by this method is 9 nm at a resolution of 3 nm.

  15. Imaging bacterial 3D motion using digital in-line holographic microscopy and correlation-based de-noising algorithm.

    PubMed

    Molaei, Mehdi; Sheng, Jian

    2014-12-29

    Better understanding of bacteria environment interactions in the context of biofilm formation requires accurate 3-dimentional measurements of bacteria motility. Digital Holographic Microscopy (DHM) has demonstrated its capability in resolving 3D distribution and mobility of particulates in a dense suspension. Due to their low scattering efficiency, bacteria are substantially difficult to be imaged by DHM. In this paper, we introduce a novel correlation-based de-noising algorithm to remove the background noise and enhance the quality of the hologram. Implemented in conjunction with DHM, we demonstrate that the method allows DHM to resolve 3-D E. coli bacteria locations of a dense suspension (>107 cells/ml) with submicron resolutions (<0.5 µm) over substantial depth and to obtain thousands of 3D cell trajectories. PMID:25607177

  16. Real-time optical correlator using computer-generated holographic filter on a liquid crystal light valve

    NASA Technical Reports Server (NTRS)

    Chao, Tien-Hsin; Yu, Jeffrey

    1990-01-01

    Limitations associated with the binary phase-only filter often used in optical correlators are presently circumvented in the writing of complex-valued data on a gray-scale spatial light modulator through the use of a computer-generated hologram (CGH) algorithm. The CGH encodes complex-valued data into nonnegative real CGH data in such a way that it may be encoded in any of the available gray-scale spatial light modulators. A CdS liquid-crystal light valve is used for the complex-valued CGH encoding; computer simulations and experimental results are compared, and the use of such a CGH filter as the synapse hologram in a holographic optical neural net is discussed.

  17. Imaging bacterial 3D motion using digital in-line holographic microscopy and correlation-based de-noising algorithm

    PubMed Central

    Molaei, Mehdi; Sheng, Jian

    2014-01-01

    Abstract: Better understanding of bacteria environment interactions in the context of biofilm formation requires accurate 3-dimentional measurements of bacteria motility. Digital Holographic Microscopy (DHM) has demonstrated its capability in resolving 3D distribution and mobility of particulates in a dense suspension. Due to their low scattering efficiency, bacteria are substantially difficult to be imaged by DHM. In this paper, we introduce a novel correlation-based de-noising algorithm to remove the background noise and enhance the quality of the hologram. Implemented in conjunction with DHM, we demonstrate that the method allows DHM to resolve 3-D E. coli bacteria locations of a dense suspension (>107 cells/ml) with submicron resolutions (<0.5 µm) over substantial depth and to obtain thousands of 3D cell trajectories. PMID:25607177

  18. High resolution MRI evaluation of meniscal volume and anthropometric correlations.

    PubMed

    Narvy, Steven J; Asami, Danny K; Solomon, Thomas C; Burke, Wendy S; Colletti, Patrick M; Vangsness, C Thomas

    2015-09-01

    The purpose of this study was to digitally determine meniscal volumes, and compare them with linear and surface area anthropometric measurements to evaluate these measurements for meniscal allograft sizing. Eighteen subjects (10 male and 8 female; mean age 37.5 years) underwent 3.0 T knee magnetic resonance imaging (MRI) of the dominant leg. The following morphometric measurements were evaluated: medial meniscal volume (MMV), lateral meniscal volume (LMV), tibial plateau width (TPW), width of the femoral condyles (WFC), and tibial plateau surface area (TPSA). MMV and LMV were compared to TPW, WFC, and TPSA. Meniscal volume and TPW were correlated to height and body-mass index (BMI) and stratified by gender. Statistical analysis included coefficient of determination (r(2)) between MRI-based MMV, LMV, TPW, TPSA, WFC, height, BMI, and gender. Significance was set at the P = 0.05 level. The mean MMV was 2275 mm(3) and the mean LMV was 2102 mm(3). TPW correlated well with meniscal volumes (r(2) > 0.62). WFC and TPSA correlated with meniscal volumes in the range of 0.40 < r(2) < 0.61. Height, BMI, and gender correlated poorly with total meniscal volume and TPW with values of r(2) < 0.44. Medial and lateral menisci have statistically similar volumes. TPW had the greatest utility for volumetric meniscal sizing. MRI-based TPW can be considered as a statistically accurate measurement for determining meniscal volumes and meniscal size. PMID:26118625

  19. Performance analysis of content-addressable search and bit-error rate characteristics of a defocused volume holographic data storage system.

    PubMed

    Das, Bhargab; Joseph, Joby; Singh, Kehar

    2007-08-01

    One of the methods for smoothing the high intensity dc peak in the Fourier spectrum for reducing the reconstruction error in a Fourier transform volume holographic data storage system is to record holograms some distance away from or in front of the Fourier plane. We present the results of our investigation on the performance of such a defocused holographic data storage system in terms of bit-error rate and content search capability. We have evaluated the relevant recording geometry through numerical simulation, by obtaining the intensity distribution at the output detector plane. This has been done by studying the bit-error rate and the content search capability as a function of the aperture size and position of the recording material away from the Fourier plane. PMID:17676163

  20. Holographic content addressable storage

    NASA Astrophysics Data System (ADS)

    Chao, Tien-Hsin; Lu, Thomas; Reyes, George

    2015-03-01

    We have developed a Holographic Content Addressable Storage (HCAS) architecture. The HCAS systems consists of a DMD (Digital Micromirror Array) as the input Spatial Light Modulator (SLM), a CMOS (Complementary Metal-oxide Semiconductor) sensor as the output photodetector and a photorefractive crystal as the recording media. The HCAS system is capable of performing optical correlation of an input image/feature against massive reference data set stored in the holographic memory. Detailed system analysis will be reported in this paper.

  1. Holographic velocimetry using object-conjugate reconstruction (OCR): a new approach for simultaneous, 3D displacement measurement in fluid and solid mechanics

    NASA Astrophysics Data System (ADS)

    Barnhart, D. H.; Chan, V. S. S.; Halliwell, N. A.; Coupland, J. M.

    2002-08-01

    This paper reports on a new form of holographic metrology that enables displacement measurement in both fluid and solid mechanics simultaneously. In such instances, existing holographic methods for displacement measurement would require the application of multiple techniques in a hybrid fashion. Known as object-conjugate reconstruction (OCR), our new approach unifies the disciplines of holographic velocimetry and holographic interferometry. Using complex correlation processing, it provides a sub-wavelength resolution for all three components of displacement and enables automated data extraction at selected points throughout a volume in space.

  2. Performance analysis of the FDTD method applied to holographic volume gratings: Multi-core CPU versus GPU computing

    NASA Astrophysics Data System (ADS)

    Francés, J.; Bleda, S.; Neipp, C.; Márquez, A.; Pascual, I.; Beléndez, A.

    2013-03-01

    The finite-difference time-domain method (FDTD) allows electromagnetic field distribution analysis as a function of time and space. The method is applied to analyze holographic volume gratings (HVGs) for the near-field distribution at optical wavelengths. Usually, this application requires the simulation of wide areas, which implies more memory and time processing. In this work, we propose a specific implementation of the FDTD method including several add-ons for a precise simulation of optical diffractive elements. Values in the near-field region are computed considering the illumination of the grating by means of a plane wave for different angles of incidence and including absorbing boundaries as well. We compare the results obtained by FDTD with those obtained using a matrix method (MM) applied to diffraction gratings. In addition, we have developed two optimized versions of the algorithm, for both CPU and GPU, in order to analyze the improvement of using the new NVIDIA Fermi GPU architecture versus highly tuned multi-core CPU as a function of the size simulation. In particular, the optimized CPU implementation takes advantage of the arithmetic and data transfer streaming SIMD (single instruction multiple data) extensions (SSE) included explicitly in the code and also of multi-threading by means of OpenMP directives. A good agreement between the results obtained using both FDTD and MM methods is obtained, thus validating our methodology. Moreover, the performance of the GPU is compared to the SSE+OpenMP CPU implementation, and it is quantitatively determined that a highly optimized CPU program can be competitive for a wider range of simulation sizes, whereas GPU computing becomes more powerful for large-scale simulations.

  3. Analysis of the effects of viscosity, volume, and temperature in photopolymer material for holographic applications

    NASA Astrophysics Data System (ADS)

    Guo, Jinxin; Gleeson, Michael R.; Sheridan, John T.

    2013-05-01

    In recent work carried out, we introduced the developments made to the Non-local Photo-polymerization Driven Diffusion model, and illustrate some of the useful trends, which the model predicts and then analyse their implications on photopolymer improvement. The model was improved in its physicality through the inclusion of viscosity effects (changes in fractional free volume), multiple components and their photo-kinetic and photo-physical behaviour, and free space vacuoles. In this paper, we further explore this model to provide a more rigorous and informed basis for predicting the behaviours of photopolymer materials in both photo-chemical and photo-physical sides. Such improvements include a) the analysis of the effects of viscosity on the refractive index modulation, b) the effects of the introduction of free space holes, e.g. the volumetric changes, and c) an examination of the effects of local temperatures and various concentration ratios to optimise material performance.

  4. High-speed holographic correlation system for video identification on the internet

    NASA Astrophysics Data System (ADS)

    Watanabe, Eriko; Ikeda, Kanami; Kodate, Kashiko

    2013-12-01

    Automatic video identification is important for indexing, search purposes, and removing illegal material on the Internet. By combining a high-speed correlation engine and web-scanning technology, we developed the Fast Recognition Correlation system (FReCs), a video identification system for the Internet. FReCs is an application thatsearches through a number of websites with user-generated content (UGC) and detects video content that violates copyright law. In this paper, we describe the FReCs configuration and an approach to investigating UGC websites using FReCs. The paper also illustrates the combination of FReCs with an optical correlation system, which is capable of easily replacing a digital authorization sever in FReCs with optical correlation.

  5. Cross-correlations between volume change and price change.

    PubMed

    Podobnik, Boris; Horvatic, Davor; Petersen, Alexander M; Stanley, H Eugene

    2009-12-29

    In finance, one usually deals not with prices but with growth rates R, defined as the difference in logarithm between two consecutive prices. Here we consider not the trading volume, but rather the volume growth rate R, the difference in logarithm between two consecutive values of trading volume. To this end, we use several methods to analyze the properties of volume changes |R|, and their relationship to price changes |R|. We analyze 14,981 daily recordings of the Standard and Poor's (S & P) 500 Index over the 59-year period 1950-2009, and find power-law cross-correlations between |R| and |R| by using detrended cross-correlation analysis (DCCA). We introduce a joint stochastic process that models these cross-correlations. Motivated by the relationship between |R| and |R|, we estimate the tail exponent alpha of the probability density function P(|R|) approximately |R|(-1-alpha) for both the S & P 500 Index as well as the collection of 1819 constituents of the New York Stock Exchange Composite Index on 17 July 2009. As a new method to estimate alpha, we calculate the time intervals tau(q) between events where R > q. We demonstrate that tau(q), the average of tau(q), obeys tau(q) approximately q(alpha). We find alpha approximately 3. Furthermore, by aggregating all tau(q) values of 28 global financial indices, we also observe an approximate inverse cubic law. PMID:20018772

  6. Weak correlation of starch and volume in synchronized photosynthetic cells

    NASA Astrophysics Data System (ADS)

    Rading, M. Michael; Sandmann, Michael; Steup, Martin; Chiarugi, Davide; Valleriani, Angelo

    2015-01-01

    In cultures of unicellular algae, features of single cells, such as cellular volume and starch content, are thought to be the result of carefully balanced growth and division processes. Single-cell analyses of synchronized photoautotrophic cultures of the unicellular alga Chlamydomonas reinhardtii reveal, however, that the cellular volume and starch content are only weakly correlated. Likewise, other cell parameters, e.g., the chlorophyll content per cell, are only weakly correlated with cell size. We derive the cell size distributions at the beginning of each synchronization cycle considering growth, timing of cell division and daughter cell release, and the uneven division of cell volume. Furthermore, we investigate the link between cell volume growth and starch accumulation. This work presents evidence that, under the experimental conditions of light-dark synchronized cultures, the weak correlation between both cell features is a result of a cumulative process rather than due to asymmetric partition of biomolecules during cell division. This cumulative process necessarily limits cellular similarities within a synchronized cell population.

  7. Volume phase holographic gratings for the Subaru Prime Focus Spectrograph: performance measurements of the prototype grating set

    NASA Astrophysics Data System (ADS)

    Barkhouser, Robert H.; Arns, James; Gunn, James E.

    2014-08-01

    The Prime Focus Spectrograph (PFS) is a major instrument under development for the 8.2 m Subaru telescope on Mauna Kea. Four identical, fixed spectrograph modules are located in a room above one Nasmyth focus. A 55 m fiber optic cable feeds light into the spectrographs from a robotic fiber positioner mounted at the telescope prime focus, behind the wide field corrector developed for Hyper Suprime-Cam. The positioner contains 2400 fibers and covers a 1.3 degree hexagonal field of view. Each spectrograph module will be capable of simultaneously acquiring 600 spectra. The spectrograph optical design consists of a Schmidt collimator, two dichroic beamsplitters to separate the light into three channels, and for each channel a volume phase holographic (VPH) grating and a dual- corrector, modified Schmidt reimaging camera. This design provides a 275 mm collimated beam diameter, wide simultaneous wavelength coverage from 380 nm to 1.26 µm, and good imaging performance at the fast f/1.1 focal ratio required from the cameras to avoid oversampling the fibers. The three channels are designated as the blue, red, and near-infrared (NIR), and cover the bandpasses 380-650 nm (blue), 630-970 nm (red), and 0.94-1.26 µm (NIR). A mosaic of two Hamamatsu 2k×4k, 15 µm pixel CCDs records the spectra in the blue and red channels, while the NIR channel employs a 4k×4k, substrate-removed HAWAII-4RG array from Teledyne, with 15 µm pixels and a 1.7 µm wavelength cutoff. VPH gratings have become the dispersing element of choice for moderate-resolution astronomical spectro- graphs due their potential for very high diffraction efficiency, low scattered light, and the more compact instru- ment designs offered by transmissive dispersers. High quality VPH gratings are now routinely being produced in the sizes required for instruments on large telescopes. These factors made VPH gratings an obvious choice for PFS. In order to reduce risk to the project, as well as fully exploit the performance

  8. Does Variability in Cognitive Performance Correlate with Frontal Brain Volume?

    PubMed Central

    Lövdén, Martin; Schmiedek, Florian; Kennedy, Kristen M.; Rodrigue, Karen M.; Lindenberger, Ulman; Raz, Naftali

    2012-01-01

    Little is known about the neural correlates of within-person variability in cognitive performance. We investigated associations between regional brain volumes and trial-to-trial, block-to-block, and day-to-day variability in choice-reaction time, and episodic and working memory accuracy. Healthy younger (n = 25) and older (n = 18) adults underwent 101 daily assessments of cognitive performance, and their regional brain volumes were measured manually on magnetic resonance images. Results showed that smaller prefrontal white matter volumes were associated with higher block-to-block variability in choice-reaction time performance, with a stronger association observed among older adults. Smaller volumes of the dorsolateral prefrontal cortex covaried with higher block-to-block variability in episodic memory (number-word pair) performance. This association was stronger for younger adults. The observed associations between variability and brain volume were not due to individual differences in mean performance. Trial-to-trial and day-to-day variability in cognitive performance were unrelated to regional brain volume. We thus report novel findings demonstrating that block-by-block variability in cognitive performance is associated with integrity of the prefrontal regions and that between-person differences in different measures of variability of cognitive performance reflect different age-related constellations of behavioral and neural antecedents. PMID:23000256

  9. Measurement of absolute cell volume, osmotic membrane water permeability, and refractive index of transmembrane water and solute flux by digital holographic microscopy

    NASA Astrophysics Data System (ADS)

    Boss, Daniel; Kühn, Jonas; Jourdain, Pascal; Depeursinge, Christian; Magistretti, Pierre J.; Marquet, Pierre

    2013-03-01

    A dual-wavelength digital holographic microscope to measure absolute volume of living cells is proposed. The optical setup allows us to reconstruct two quantitative phase contrast images at two different wavelengths from a single hologram acquisition. When adding the absorbing dye fast green FCF as a dispersive agent to the extracellular medium, cellular thickness can be univocally determined in the full field of view. In addition to the absolute cell volume, the method can be applied to derive important biophysical parameters of living cells including osmotic membrane water permeability coefficient and the integral intracellular refractive index (RI). Further, the RI of transmembrane flux can be determined giving an indication about the nature of transported solutes. The proposed method is applied to cultured human embryonic kidney cells, Chinese hamster ovary cells, human red blood cells, mouse cortical astrocytes, and neurons.

  10. Putamen volume correlates with obsessive compulsive characteristics in healthy population.

    PubMed

    Kubota, Yasutaka; Sato, Wataru; Kochiyama, Takanori; Uono, Shota; Yoshimura, Sayaka; Sawada, Reiko; Sakihama, Morimitsu; Toichi, Motomi

    2016-03-30

    Obsessions and compulsions (OCs) are frequent in healthy subjects; however neural backgrounds of the subclinical OCs were largely unknown. Results from recent studies suggested involvement of the putamen in the OC traits. To investigate this issue, 49 healthy subjects were assessed using structural magnetic resonance imaging (MRI) and the Maudsley Obsessive Compulsive Inventory (MOCI). Anatomical delineation on MRI yielded the global volume and local shape of the putamen. Other striatal structures (the caudate nucleus and globus pallidus) were also examined for exploratory purpose. The relationship between volume/shape of each structures and MOCI measure was analyzed, with sex, age, state anxiety, trait anxiety, and full-scale Intelligence Quotient regressed out. The volume analysis revealed a positive relationship between the MOCI total score and the bilateral putamen volumes. The shape analysis demonstrated associations between the higher MOCI total score and hypertrophy of the anterior putamen in both hemispheres. The present study firstly revealed that the volume changes of the putamen correlated with the manifestation of subclinical OC traits. The dysfunctional cortico-anterior striatum networks seemed to be one of the neuronal subsystems underlying the subclinical OC traits. PMID:26849956

  11. Cross-correlations between volume change and price change

    PubMed Central

    Podobnik, Boris; Horvatic, Davor; Petersen, Alexander M.; Stanley, H. Eugene

    2009-01-01

    In finance, one usually deals not with prices but with growth rates R, defined as the difference in logarithm between two consecutive prices. Here we consider not the trading volume, but rather the volume growth rate R̃, the difference in logarithm between two consecutive values of trading volume. To this end, we use several methods to analyze the properties of volume changes |R̃|, and their relationship to price changes |R|. We analyze 14,981 daily recordings of the Standard and Poor's (S & P) 500 Index over the 59-year period 1950–2009, and find power-law cross-correlations between |R| and |R̃| by using detrended cross-correlation analysis (DCCA). We introduce a joint stochastic process that models these cross-correlations. Motivated by the relationship between |R| and |R̃|, we estimate the tail exponent α̃ of the probability density function P(|R̃|) ∼ |R̃|−1−α̃ for both the S & P 500 Index as well as the collection of 1819 constituents of the New York Stock Exchange Composite Index on 17 July 2009. As a new method to estimate α̃, we calculate the time intervals τq between events where R̃ > q. We demonstrate that τ̃q, the average of τq, obeys τ̃q ∼ qα̃. We find α̃ ≈ 3. Furthermore, by aggregating all τq values of 28 global financial indices, we also observe an approximate inverse cubic law. PMID:20018772

  12. Real-time holographic camera system

    NASA Astrophysics Data System (ADS)

    Bazhenov, Mikhail Y.; Grabovski, Vitaly V.; Stolyarenko, Alexandr V.; Zahaykevich, George A.

    1997-04-01

    The holographic camera system for surface-relief hologram multiple reversible registration is presented. Photosensitive media is a single-layer photothermoplastic polymer on a glass substrate with conductive layer. This exclude a charges accumulation in the polymer volume and permits to realize an efficient enhancement of latent electrostatic image and its fast pulse heating development. The processes of charging, photogeneration, carriers transport, fast development and erasing, image enhancement were studied in detail and optimized. In order to improve some defects of photothermoplastic recording, originating from influences of circumstances and recording conditions, some new processes were developed: (1) fast charging with pulses corona in closed dielectric volume, (2) optoelectronic enhancement of electrostatic image, and (3) fast pulsed development with automatically controlled temperature rate. The dust-proof recording camera with built-in highvoltage power supply, thermo- and photosensors was designed to meet the needs of real-time or multiple- exposure interferometry, holographic training recording, holographic storage systems, correlation investigations and pattern recognition.

  13. Effects of pore volume-transmissivity correlation on transport phenomena

    NASA Astrophysics Data System (ADS)

    Lunati, Ivan; Kinzelbach, Wolfgang; Sørensen, Ivan

    2003-12-01

    The relevant velocity that describes transport phenomena in a porous medium is the pore velocity. For this reason, one needs not only to describe the variability of transmissivity, which fully determines the Darcy velocity field for given source terms and boundary conditions, but also any variability of the pore volume. We demonstrate that hydraulically equivalent media with exactly the same transmissivity field can produce dramatic differences in the displacement of a solute if they have different pore volume distributions. In particular, we demonstrate that correlation between pore volume and transmissivity leads to a much smoother and more homogeneous solute distribution. This was observed in a laboratory experiment performed in artificial fractures made of two plexiglass plates into which a space-dependent aperture distribution was milled. Using visualization by a light transmission technique, we observe that the solute behaviour is much smoother and more regular after the fractures are filled with glass powder, which plays the role of a homogeneous fault gouge material. This is due to a perfect correlation between pore volume and transmissivity that causes pore velocity to be not directly dependent on the transmissivity, but only indirectly through the hydraulic gradient, which is a much smoother function due to the diffusive behaviour of the flow equation acting as a filter. This smoothing property of the pore volume-transmissivity correlation is also supported by numerical simulations of tracer tests in a dipole flow field. Three different conceptual models are used: an empty fracture, a rough-walled fracture filled with a homogeneous material and a parallel-plate fracture with a heterogeneous fault gouge. All three models are hydraulically equivalent, yet they have a different pore volume distribution. Even if piezometric heads and specific flow rates are exactly the same at any point of the domain, the transport process differs dramatically. These

  14. Holographic diffusers

    NASA Astrophysics Data System (ADS)

    Wadle, Stephen; Wuest, Daniel; Cantalupo, John; Lakes, Roderic S.

    1994-01-01

    Holographic diffusers are prepared using silver halide (Agfa 8E75 and Kodak 649F) and photopolymer (Polaroid DMP 128 and DuPont 600, 705, and 150 series) media. It is possible to control the diffusion angle in three ways: by selection of the properties of the source diffuser, by control of its subtended angle, and by selection of the holographic medium. Several conventional diffusers based on refraction or scattering of light are examined for comparison.

  15. Heavy quark correlations and the effective volume for quarkonia production

    NASA Astrophysics Data System (ADS)

    Liu, Yunpeng; Ko, Che Ming; Li, Feng

    2016-03-01

    Using the Boltzmann transport approach, we study the effect of initial spatial and momentum correlations between a heavy quark pair, such as that produced from a p +p collision, on their collision rate in a partonic medium, which is relevant for their thermalization and the production of quarkonium from regeneration. Characterizing this effect by an effective volume given by the inverse of the ratio of their collision rate to the collision rate of a thermally equilibrated and spatially uniformly distributed heavy quark pair in a unit volume, we find that the effective volume is finite and depends sensitively on the momentum of the heavy quark and the temperature of the medium. Generally, it increases linearly with time t at the very beginning, thus an enhanced collision rate, and the increase then becomes slower due to multiple scattering, and finally it increases as t3 /2. We further find that the momentum distribution of the colliding heavy quark pair approaches a thermal distribution after about 5 fm /c with an effective temperature similar to that of the medium even though their transverse momentum spectra initially have a δ -like distribution.

  16. A low-resolution 3D holographic volumetric display

    NASA Astrophysics Data System (ADS)

    Khan, Javid; Underwood, Ian; Greenaway, Alan; Halonen, Mikko

    2010-05-01

    A simple low resolution volumetric display is presented, based on holographic volume-segments. The display system comprises a proprietary holographic screen, laser projector, associated optics plus a control unit. The holographic screen resembles a sheet of frosted glass about A4 in size (20x30cm). The holographic screen is rear-illuminated by the laser projector, which is in turn driven by the controller, to produce simple 3D images that appear outside the plane of the screen. A series of spatially multiplexed and interleaved interference patterns are pre-encoded across the surface of the holographic screen. Each illumination pattern is capable of reconstructing a single holographic volume-segment. Up to nine holograms are multiplexed on the holographic screen in a variety of configurations including a series of numeric and segmented digits. The demonstrator has good results under laboratory conditions with moving colour 3D images in front of or behind the holographic screen.

  17. Amniotic fluid index: correlation with amniotic fluid volume.

    PubMed

    Hoskins, I A; McGovern, P G; Ordorica, S A; Frieden, F J; Young, B K

    1992-01-01

    We calculated the amniotic fluid indexes (AFIs) of 310 women on 459 occasions. Normative data were analyzed and compared with data in several high-risk groups. In the normal gestations there was a progressive increase in AFI with advancing gestation until 32 weeks, after which there was a decline. The mean AFIs in abnormal gestations varied with the clinical diagnoses. These values were compared to those obtained by assessing amniotic fluid volume (AFV), that is a pocket more than 2 cm. There were 51 patients with abnormal AFVs. Forty-two had decreased fluid, six also had decreased AFIs; nine had increased AFVs and five (all with diabetes) also had increased AFIs. Thus, AFIs in normal pregnancies showed an orderly pattern of change with gestational age, and there was no accurate correlation between AFI and AFV. Thus, using AFV alone may lead to false interpretations of amniotic fluid status. PMID:1418123

  18. Quantitative measurement of absolute cell volume and intracellular integral refractive index (RI) with dual-wavelength digital holographic microscopy (DHM)

    NASA Astrophysics Data System (ADS)

    Boss, Daniel; Kühn, Jonas; Depeursinge, Christian; Magistretti, Pierre J.; Marquet, Pierre

    2012-06-01

    Quantitative Phase Imaging techniques including DHM have been applied recently in the field of cell imaging to monitor and quantify non-invasively dynamic cellular processes modifying cell morphology and/or content . Concretely, the DHM phase signal is highly sensitive to cell thickness and intracellular integral RI variations associated with transmembrane water movements. As net water flow across the cell membrane leads at the same time to changes in cell thickness and intracellular RI, the interpretation of phase signal variations remains difficult. To overcome this drawback, we have developed a Dual-wavelength Digital Holographic Microscopy (DHM) setup allowing to separately measure, with a single CCD camera acquisition, thickness and integral RI of living cells. The method is based on the use of an absorbing dye that enhances the refractive index dispersion of the extracellular medium. Practically, two significantly different phase signals can be obtained when measuring at two appropriate wavelengths. From the two phase measurements, both cell RI and thickness can be univocally determined.

  19. Intelligent holographic databases

    NASA Astrophysics Data System (ADS)

    Barbastathis, George

    Memory is a key component of intelligence. In the human brain, physical structure and functionality jointly provide diverse memory modalities at multiple time scales. How could we engineer artificial memories with similar faculties? In this thesis, we attack both hardware and algorithmic aspects of this problem. A good part is devoted to holographic memory architectures, because they meet high capacity and parallelism requirements. We develop and fully characterize shift multiplexing, a novel storage method that simplifies disk head design for holographic disks. We develop and optimize the design of compact refreshable holographic random access memories, showing several ways that 1 Tbit can be stored holographically in volume less than 1 m3, with surface density more than 20 times higher than conventional silicon DRAM integrated circuits. To address the issue of photorefractive volatility, we further develop the two-lambda (dual wavelength) method for shift multiplexing, and combine electrical fixing with angle multiplexing to demonstrate 1,000 multiplexed fixed holograms. Finally, we propose a noise model and an information theoretic metric to optimize the imaging system of a holographic memory, in terms of storage density and error rate. Motivated by the problem of interfacing sensors and memories to a complex system with limited computational resources, we construct a computer game of Desert Survival, built as a high-dimensional non-stationary virtual environment in a competitive setting. The efficacy of episodic learning, implemented as a reinforced Nearest Neighbor scheme, and the probability of winning against a control opponent improve significantly by concentrating the algorithmic effort to the virtual desert neighborhood that emerges as most significant at any time. The generalized computational model combines the autonomous neural network and von Neumann paradigms through a compact, dynamic central representation, which contains the most salient features

  20. Analytic holographic superconductor

    NASA Astrophysics Data System (ADS)

    Herzog, Christopher P.

    2010-06-01

    We investigate a holographic superconductor that admits an analytic treatment near the phase transition. In the dual 3+1-dimensional field theory, the phase transition occurs when a scalar operator of scaling dimension two gets a vacuum expectation value. We calculate current-current correlation functions along with the speed of second sound near the critical temperature. We also make some remarks about critical exponents. An analytic treatment is possible because an underlying Heun equation describing the zero mode of the phase transition has a polynomial solution. Amusingly, the treatment here may generalize for an order parameter with any integer spin, and we propose a Lagrangian for a spin-two holographic superconductor.

  1. Formation of uniform fringe pattern free from diffraction noise at LDA measurement volume using holographic imaging configuration

    NASA Astrophysics Data System (ADS)

    Ghosh, Abhijit; Nirala, A. K.

    2016-05-01

    In the present study we have proposed a technique for improving fringe quality at laser Doppler anemometry measurement volume in real time using single hololens imaging configuration over conventional imaging configuration with Gaussian beam optics. In order to remove interference fringe gradients as well as higher order diffraction noise formed at measurement volume in the former approach, a combined hololens imaging system has also been proposed. For qualitative as well as quantitative analysis of fringes formed at measurement volume, atomic force microscopy (AFM) analysis has been performed.

  2. Holographic vitrification

    NASA Astrophysics Data System (ADS)

    Anninos, Dionysios; Anous, Tarek; Denef, Frederik; Peeters, Lucas

    2015-04-01

    We establish the existence of stable and metastable stationary black hole bound states at finite temperature and chemical potentials in global and planar four-dimensional asymptotically anti-de Sitter space. We determine a number of features of their holographic duals and argue they represent structural glasses. We map out their thermodynamic landscape in the probe approximation, and show their relaxation dynamics exhibits logarithmic aging, with aging rates determined by the distribution of barriers.

  3. Fast fluorescence holographic microscopy

    PubMed Central

    Qin, Wan; Yang, Xiaoqi; Li, Yingying; Peng, Xiang; Qu, Xinghua; Yao, Hai; Gao, Bruce Z.

    2015-01-01

    FINCHSCOPE is a new technology of fluorescence holographic microscopy. It has been successfully applied to recording high-resolution three-dimensional fluorescence images of biological specimens without the need for scanning. In this study, we revealed and analyzed an intrinsic phenomenon, called ghost lens effect, on spatial light modulator which is the core element enabling the incoherent correlation in the FINCHSCOPE. The ghost lens effect can degrade the imaging quality by introducing multiple spherical waves with different focal lengths into the correlation and thus increasing the noise in the recorded holograms. PMID:25767693

  4. Tuning Ion Conducting Pathways Using Holographic Polymerization

    NASA Astrophysics Data System (ADS)

    Smith, Derrick; Li, Christopher; Dong, Bin; Bunning, Timothy

    2012-02-01

    While much research has demonstrated repeatable characteristics of electrolyte membranes, the fundamentals behind the interactions during ionic diffusion in solid polymer electrolyte membranes for battery applications are not well understood, specifically the role of nanostructures, which hold the key to improving performance of energy storage devices such as fuel cells and Lithium ion batteries. The challenges in fabricating highly controlled model systems are largely responsible for the interdependent ambiguities between nanostructures and the corresponding ion conducting behavior. In this work, Holographic Polymer Electrolyte Membranes (hPEM) volume gratings comprised of alternating layers of crosslinked polymer resin and lithium ion salt were fabricated using holographic polymerization with an average d-spacing of approximately 200 nm. These one-dimensional confinement structures were used to quantitatively study the anisotropic ionic conductivity between the directions of in-plane and normal to the layers, and the unique ion conducting behavior was correlated with nanoscale phase separation. These volume gratings also offer an exciting route to fabricate multifunctional gratings for optic and sensing applications.

  5. Holographic Spacetime

    NASA Astrophysics Data System (ADS)

    Banks, Tom

    2012-10-01

    The theory of holographic spacetime (HST) generalizes both string theory and quantum field theory (QFT). It provides a geometric rationale for supersymmetry (SUSY) and a formalism in which super-Poincare invariance follows from Poincare invariance. HST unifies particles and black holes, realizing both as excitations of noncommutative geometrical variables on a holographic screen. Compact extra dimensions are interpreted as finite-dimensional unitary representations of super-algebras, and have no moduli. Full field theoretic Fock spaces, and continuous moduli are both emergent phenomena of super-Poincare invariant limits in which the number of holographic degrees of freedom goes to infinity. Finite radius de Sitter (dS) spaces have no moduli, and break SUSY with a gravitino mass scaling like Λ1/4. In regimes where the Covariant Entropy Bound is saturated, QFT is not a good description in HST, and inflation is such a regime. Following ideas of Jacobson, the gravitational and inflaton fields are emergent classical variables, describing the geometry of an underlying HST model, rather than "fields associated with a microscopic string theory". The phrase in quotes is meaningless in the HST formalism, except in asymptotically flat and AdS spacetimes, and some relatives of these.

  6. Holographic photolysis of caged neurotransmitters

    PubMed Central

    Lutz, Christoph; Otis, Thomas S.; DeSars, Vincent; Charpak, Serge; DiGregorio, David A.; Emiliani, Valentina

    2009-01-01

    Stimulation of light-sensitive chemical probes has become a powerful tool for the study of dynamic signaling processes in living tissue. Classically, this approach has been constrained by limitations of lens–based and point-scanning illumination systems. Here we describe a novel microscope configuration that incorporates a nematic liquid crystal spatial light modulator (LC-SLM) to generate holographic patterns of illumination. This microscope can produce illumination spots of variable size and number and patterns shaped to precisely match user-defined elements in a specimen. Using holographic illumination to photolyse caged glutamate in brain slices, we demonstrate that shaped excitation on segments of neuronal dendrites and simultaneous, multi-spot excitation of different dendrites enables precise spatial and rapid temporal control of glutamate receptor activation. By allowing the excitation volume shape to be tailored precisely, the holographic microscope provides an extremely flexible method for activation of various photosensitive proteins and small molecules. PMID:19160517

  7. The traveltime holographic principle

    NASA Astrophysics Data System (ADS)

    Huang, Yunsong; Schuster, Gerard T.

    2015-01-01

    Fermat's interferometric principle is used to compute interior transmission traveltimes τpq from exterior transmission traveltimes τsp and τsq. Here, the exterior traveltimes are computed for sources s on a boundary B that encloses a volume V of interior points p and q. Once the exterior traveltimes are computed, no further ray tracing is needed to calculate the interior times τpq. Therefore this interferometric approach can be more efficient than explicitly computing interior traveltimes τpq by ray tracing. Moreover, the memory requirement of the traveltimes is reduced by one dimension, because the boundary B is of one fewer dimension than the volume V. An application of this approach is demonstrated with interbed multiple (IM) elimination. Here, the IMs in the observed data are predicted from the migration image and are subsequently removed by adaptive subtraction. This prediction is enabled by the knowledge of interior transmission traveltimes τpq computed according to Fermat's interferometric principle. We denote this principle as the `traveltime holographic principle', by analogy with the holographic principle in cosmology where information in a volume is encoded on the region's boundary.

  8. Holographic Optical Data Storage

    NASA Technical Reports Server (NTRS)

    Timucin, Dogan A.; Downie, John D.; Norvig, Peter (Technical Monitor)

    2000-01-01

    Although the basic idea may be traced back to the earlier X-ray diffraction studies of Sir W. L. Bragg, the holographic method as we know it was invented by D. Gabor in 1948 as a two-step lensless imaging technique to enhance the resolution of electron microscopy, for which he received the 1971 Nobel Prize in physics. The distinctive feature of holography is the recording of the object phase variations that carry the depth information, which is lost in conventional photography where only the intensity (= squared amplitude) distribution of an object is captured. Since all photosensitive media necessarily respond to the intensity incident upon them, an ingenious way had to be found to convert object phase into intensity variations, and Gabor achieved this by introducing a coherent reference wave along with the object wave during exposure. Gabor's in-line recording scheme, however, required the object in question to be largely transmissive, and could provide only marginal image quality due to unwanted terms simultaneously reconstructed along with the desired wavefront. Further handicapped by the lack of a strong coherent light source, optical holography thus seemed fated to remain just another scientific curiosity, until the field was revolutionized in the early 1960s by some major breakthroughs: the proposition and demonstration of the laser principle, the introduction of off-axis holography, and the invention of volume holography. Consequently, the remainder of that decade saw an exponential growth in research on theory, practice, and applications of holography. Today, holography not only boasts a wide variety of scientific and technical applications (e.g., holographic interferometry for strain, vibration, and flow analysis, microscopy and high-resolution imagery, imaging through distorting media, optical interconnects, holographic optical elements, optical neural networks, three-dimensional displays, data storage, etc.), but has become a prominent am advertising

  9. A new method for determination of postmortem left ventricular volumes: clinico-pathologic correlations.

    PubMed

    Wissler, R W; Lichtig, C; Hughes, R; Al-Sadir, J; Glagov, S

    1975-05-01

    A description is presented of a new and simple procedure for ventricular volume determination by means of pressure fixation of the heart and preparation of plastic molds of the ventricles which can be used to displace water in a graduated cylinder to determine the volume of the mold. Correlations between postmortem ventricular volume as measured by this method and antemortem stroke volume or clinical cardiac status indicate that a large left ventricular volume is often correlated with a low cardiac output and cardiogenic shock. PMID:1119371

  10. Holographic turbulence.

    PubMed

    Adams, Allan; Chesler, Paul M; Liu, Hong

    2014-04-18

    We construct turbulent black holes in asymptotically AdS4 spacetime by numerically solving Einstein's equations. Using the AdS/CFT correspondence we find that both the dual holographic fluid and bulk geometry display signatures of an inverse cascade with the bulk geometry being well approximated by the fluid-gravity gradient expansion. We argue that statistically steady-state black holes dual to d dimensional turbulent flows have horizons whose area growth has a fractal-like structure with fractal dimension D=d+4/3. PMID:24785028

  11. Preterm Infant Hippocampal Volumes Correlate with Later Working Memory Deficits

    ERIC Educational Resources Information Center

    Beauchamp, Miriam H.; Thompson, Deanne K.; Howard, Kelly; Doyle, Lex W.; Egan, Gary F.; Inder, Terrie E.; Anderson, Peter J.

    2008-01-01

    Children born preterm exhibit working memory deficits. These deficits may be associated with structural brain changes observed in the neonatal period. In this study, the relationship between neonatal regional brain volumes and working memory deficits at age 2 years were investigated, with a particular interest in the dorsolateral prefrontal…

  12. Holographic enhanced remote sensing system

    NASA Technical Reports Server (NTRS)

    Iavecchia, Helene P.; Gaynor, Edwin S.; Huff, Lloyd; Rhodes, William T.; Rothenheber, Edward H.

    1990-01-01

    The Holographic Enhanced Remote Sensing System (HERSS) consists of three primary subsystems: (1) an Image Acquisition System (IAS); (2) a Digital Image Processing System (DIPS); and (3) a Holographic Generation System (HGS) which multiply exposes a thermoplastic recording medium with sequential 2-D depth slices that are displayed on a Spatial Light Modulator (SLM). Full-parallax holograms were successfully generated by superimposing SLM images onto the thermoplastic and photopolymer. An improved HGS configuration utilizes the phase conjugate recording configuration, the 3-SLM-stacking technique, and the photopolymer. The holographic volume size is currently limited to the physical size of the SLM. A larger-format SLM is necessary to meet the desired 6 inch holographic volume. A photopolymer with an increased photospeed is required to ultimately meet a display update rate of less than 30 seconds. It is projected that the latter two technology developments will occur in the near future. While the IAS and DIPS subsystems were unable to meet NASA goals, an alternative technology is now available to perform the IAS/DIPS functions. Specifically, a laser range scanner can be utilized to build the HGS numerical database of the objects at the remote work site.

  13. Holographic Aquaculture

    NASA Astrophysics Data System (ADS)

    Ian, Richard; King, Elisabeth

    1988-01-01

    Proposed is an exploratory study to verify the feasibility of an inexpensive micro-climate control system for both marine and freshwater pond and tank aquaculture, offering good control over water temperature, incident light flux, and bandwidth, combined with good energy efficiency. The proposed control system utilizes some familiar components of passive solar design, together with a new holographic glazing system which is currently being developed by, and proprietary to Advanced Environmental Research Group (AERG). The use of solar algae ponds and tanks to warm and purify water for fish and attached macroscopic marine algae culture is an ancient and effective technique, but limited seasonally and geographically by the availability of sunlight. Holographic Diffracting Structures (HDSs) can be made which passively track, accept and/or reject sunlight from a wide range of altitude and azimuth angles, and redirect and distribute light energy as desired (either directly or indirectly over water surface in an enclosed, insulated structure), effectively increasing insolation values by accepting sunlight which would not otherwise enter the structure.

  14. Holographic Gratings for Optical Processing

    NASA Technical Reports Server (NTRS)

    Kukhtarev, Nickolai

    2002-01-01

    Investigation of astronomical objects and tracking of man-made space objects lead to generation of huge amount of information for optical processing. Traditional big-size optical elements (such as optical telescopes) have a tendency for increasing aperture size in order to improve sensitivity. This tendency leads to increasing of weight and costs of optical systems and stimulate search for the new, more adequate technologies. One approach to meet these demands is based on developing of holographic optical elements using new polymeric materials. We have investigated possibility to use new material PQ-PMMA (phenantrenequinone-doped PMMA (Polymethyl Methacrylate)) for fabrication of highly selective optical filters and fast spatial-temporal light modulators. This material was originally developed in Russia and later was tested in CalTech as a candidate material for optical storage. Our theoretical investigation predicts the possibility of realization of fast spatial and temporal light modulation, using volume reflection-type spectral filter. We have developed also model of holographic-grating recording in PQ-PMMA material, based on diffusional amplification. This mechanism of recording allow to receive high diffraction efficiency during recording of reflection-type volume holographic grating (holographic mirror). We also investigated recording of dynamic gratings in the photorefractive crystals LiNbO3 (LN) for space-based spectroscopy and for adaptive correction of aberrations in the telescope's mirrors. We have shown, that specific 'photogalvanic' mechanism of holographic grating recording in LN allow to realize recording of blazed gratings for volume and surface gratings. Possible applications of dynamic gratings in LN for amplification of images, transmitted through an imaging fiber guide was also demonstrated.

  15. Complementary Characteristics of Correlation Patterns in Morphometric Correlation Networks of Cortical Thickness, Surface Area, and Gray Matter Volume.

    PubMed

    Yang, Jin-Ju; Kwon, Hunki; Lee, Jong-Min

    2016-01-01

    Morphometric correlation networks of cortical thickness, surface area, and gray matter volume have statistically different structural topology. However, there is no report directly describing their correlation patterns in view of interregional covariance. Here, we examined the characteristics of the correlation patterns in three morphometric networks of cortical thickness, surface area, and gray matter volume using a Venn diagram concept across 314 normal subjects. We found that over 60% of all nonoverlapping correlation patterns emerged with divergent unique patterns, while there were 10% of all common edges in ipsilateral and homotopic regions among the three morphometric correlation networks. It was also found that the network parameters of the three networks were different. Our findings showed that correlation patterns of the network itself can provide complementary information when compared with network properties. We demonstrate that morphometric correlation networks of distinct structural phenotypes have different correlation patterns and different network properties. This finding implies that the topology of each morphometric correlation network may reflect different aspects of each morphometric descriptor. PMID:27226000

  16. Complementary Characteristics of Correlation Patterns in Morphometric Correlation Networks of Cortical Thickness, Surface Area, and Gray Matter Volume

    PubMed Central

    Yang, Jin-Ju; Kwon, Hunki; Lee, Jong-Min

    2016-01-01

    Morphometric correlation networks of cortical thickness, surface area, and gray matter volume have statistically different structural topology. However, there is no report directly describing their correlation patterns in view of interregional covariance. Here, we examined the characteristics of the correlation patterns in three morphometric networks of cortical thickness, surface area, and gray matter volume using a Venn diagram concept across 314 normal subjects. We found that over 60% of all nonoverlapping correlation patterns emerged with divergent unique patterns, while there were 10% of all common edges in ipsilateral and homotopic regions among the three morphometric correlation networks. It was also found that the network parameters of the three networks were different. Our findings showed that correlation patterns of the network itself can provide complementary information when compared with network properties. We demonstrate that morphometric correlation networks of distinct structural phenotypes have different correlation patterns and different network properties. This finding implies that the topology of each morphometric correlation network may reflect different aspects of each morphometric descriptor. PMID:27226000

  17. Hybrid holographic non-destructive test system

    NASA Technical Reports Server (NTRS)

    Kurtz, R. L. (Inventor)

    1978-01-01

    An automatic hybrid holographic non-destructive testing (HNDT) method and system capable of detecting flaws or debonds contained within certain materials are described. This system incorporates the techniques of optical holography, acoustical/optical holography and holographic correlation in determining the structural integrity of a test object. An automatic processing system including a detector and automatic data processor is used in conjunction with the three holographic techniques for correlating and interpreting the information supplied by the non-destructive systems. The automatic system also includes a sensor which directly translates an optical data format produced by the holographic techniques into electrical signals and then transmits this information to a digital computer for indicating the structural properties of the test object. The computer interprets the data gathered and determines whether further testing is necessary as well as the format of this new testing procedure.

  18. Holographic Compact Disk Read-Only Memories

    NASA Technical Reports Server (NTRS)

    Liu, Tsuen-Hsi

    1996-01-01

    Compact disk read-only memories (CD-ROMs) of proposed type store digital data in volume holograms instead of in surface differentially reflective elements. Holographic CD-ROM consist largely of parts similar to those used in conventional CD-ROMs. However, achieves 10 or more times data-storage capacity and throughput by use of wavelength-multiplexing/volume-hologram scheme.

  19. Holographic data processing methods for medical prognosis

    NASA Astrophysics Data System (ADS)

    Antonov, V. A.; Grosmann, M. H.; Kartavenko, V. I.; Larkin, A. I.; Trukhanov, K. A.

    2015-10-01

    The various methods of laser coherent photonic implementations of multiparametric classification are discussed in this paper. The holographic and optical data processing methods for medical application are considered. Inverse two-phase coding and analysis of light distribution in the correlation plane enables us to realize a number of algorithms: search for a precedent, Hamming distance measurement, Bayes probability algorithm, deterministic and ‘correspondence’ algorithms. The experimental holographic results for medicine prognosis are shown.

  20. Inter-Fraction Tumor Volume Response during Lung Stereotactic Body Radiation Therapy Correlated to Patient Variables

    PubMed Central

    Ayan, Ahmet S.; Mo, Xiaokui; Williams, Terence M.; Mayr, Nina A.; Grecula, John C.; Chakravarti, Arnab; Xu-Welliver, Meng

    2016-01-01

    Purpose Analyze inter-fraction volumetric changes of lung tumors treated with stereotactic body radiation therapy (SBRT) and determine if the volume changes during treatment can be predicted and thus considered in treatment planning. Methods and Materials Kilo-voltage cone-beam CT (kV-CBCT) images obtained immediately prior to each fraction were used to monitor inter-fraction volumetric changes of 15 consecutive patients (18 lung nodules) treated with lung SBRT at our institution (45–54 Gy in 3–5 fractions) in the year of 2011–2012. Spearman's (ρ) correlation and Spearman's partial correlation analysis was performed with respect to patient/tumor and treatment characteristics. Multiple hypothesis correction was performed using False Discovery Rate (FDR) and q-values were reported. Results All tumors studied experienced volume change during treatment. Tumor increased in volume by an average of 15% and regressed by an average of 11%. The overall volume increase during treatment is contained within the planning target volume (PTV) for all tumors. Larger tumors increased in volume more than smaller tumors during treatment (q = 0.0029). The volume increase on CBCT was correlated to the treatment planning gross target volume (GTV) as well as internal target volumes (ITV) (q = 0.0085 and q = 0.0039 respectively) and could be predicted for tumors with a GTV less than 22 mL. The volume increase was correlated to the integral dose (ID) in the ITV at every fraction (q = 0.0049). The peak inter-fraction volume occurred at an earlier fraction in younger patients (q = 0.0122). Conclusions We introduced a new analysis method to follow inter-fraction tumor volume changes and determined that the observed changes during lung SBRT treatment are correlated to the initial tumor volume, integral dose (ID), and patient age. Furthermore, the volume increase during treatment of tumors less than 22mL can be predicted during treatment planning. The volume increase remained

  1. Cross-correlations between price and volume in Chinese gold markets

    NASA Astrophysics Data System (ADS)

    Ruan, Qingsong; Jiang, Wei; Ma, Guofeng

    2016-06-01

    We apply the multifractal detrended cross-correlation analysis (MF-DCCA) method to investigate the cross-correlation behaviors between price and volume in Chinese gold spot and futures markets. Qualitatively, we find that the price and volume series are significantly cross-correlated using the cross-correlation test statistics Qcc(m) and the ρDCCA coefficients. Quantitatively, by employing the MF-DCCA analysis, we find that there is a power-law cross-correlation and significant multifractal features between price and volume in gold spot and futures markets. Furthermore, by comparing the multifractality of the original series to the shuffled and surrogated series, we find that, for the gold spot market, the main contribution of multifractality is fat-tail distribution; for the gold futures market, both long-range correlations and fat-tail distributions play important roles in the contribution of multifractality. Finally, by employing the method of rolling windows, we undertake further investigation into the time-varying features of the cross-correlations between price and volume. We find that for both spot and futures markets, the cross-correlations are anti-persistent in general. In the short term, the cross-correlation shows obvious fluctuations due to exogenous shocks while, in the long term, the relationship tends to be at a metastable level due to the dynamic mechanism.

  2. Prediction of free-volume-type correlations in glassy chalcogenides from positron annihilation lifetime measurements

    NASA Astrophysics Data System (ADS)

    Shpotyuk, O.; Ingram, A.; Shpotyuk, M.; Filipecki, J.

    2014-11-01

    A newly modified correlation equation between defect-related positron lifetime determined within two-state trapping model and radius of corresponding free-volume-type defects was proposed to describe compositional variations in atomic-deficient structure of covalent-bonded chalcogenides like binary As-S/Se glasses. Specific chemical environment of free-volume voids around neighboring network-forming polyhedrons was shown to play a decisive role in this correlation, leading to systematically enhanced volumes in comparison with typical molecular substrates, such as polymers.

  3. Physical Exercise Habits Correlate with Gray Matter Volume of the Hippocampus in Healthy Adult Humans

    NASA Astrophysics Data System (ADS)

    Killgore, William D. S.; Olson, Elizabeth A.; Weber, Mareen

    2013-12-01

    Physical activity facilitates neurogenesis of dentate cells in the rodent hippocampus, a brain region critical for memory formation and spatial representation. Recent findings in humans also suggest that aerobic exercise can lead to increased hippocampal volume and enhanced cognitive functioning in children and elderly adults. However, the association between physical activity and hippocampal volume during the period from early adulthood through middle age has not been effectively explored. Here, we correlated the number of minutes of self-reported exercise per week with gray matter volume of the hippocampus using voxel-based morphometry (VBM) in 61 healthy adults ranging from 18 to 45 years of age. After controlling for age, gender, and total brain volume, total minutes of weekly exercise correlated significantly with volume of the right hippocampus. Findings highlight the relationship between regular physical exercise and brain structure during early to middle adulthood.

  4. Holographic heat engines

    NASA Astrophysics Data System (ADS)

    Johnson, Clifford V.

    2014-10-01

    It is shown that in theories of gravity where the cosmological constant is considered a thermodynamic variable, it is natural to use black holes as heat engines. Two examples are presented in detail using AdS charged black holes as the working substance. We notice that for static black holes, the maximally efficient traditional Carnot engine is also a Stirling engine. The case of negative cosmological constant supplies a natural realization of these engines in terms of the field theory description of the fluids to which they are holographically dual. We first propose a precise picture of how the traditional thermodynamic dictionary of holography is extended when the cosmological constant is dynamical and then conjecture that the engine cycles can be performed by using renormalization group flow. We speculate about the existence of a natural dual field theory counterpart to the gravitational thermodynamic volume.

  5. Neuroanatomical Correlates of Intelligence in Healthy Young Adults: The Role of Basal Ganglia Volume

    PubMed Central

    Rhein, Cosima; Mühle, Christiane; Richter-Schmidinger, Tanja; Alexopoulos, Panagiotis; Doerfler, Arnd; Kornhuber, Johannes

    2014-01-01

    Background In neuropsychiatric diseases with basal ganglia involvement, higher cognitive functions are often impaired. In this exploratory study, we examined healthy young adults to gain detailed insight into the relationship between basal ganglia volume and cognitive abilities under non-pathological conditions. Methodology/Principal Findings We investigated 137 healthy adults that were between the ages of 21 and 35 years with similar educational backgrounds. Magnetic resonance imaging (MRI) was performed, and volumes of basal ganglia nuclei in both hemispheres were calculated using FreeSurfer software. The cognitive assessment consisted of verbal, numeric and figural aspects of intelligence for either the fluid or the crystallised intelligence factor using the intelligence test Intelligenz-Struktur-Test (I-S-T 2000 R). Our data revealed significant correlations of the caudate nucleus and pallidum volumes with figural and numeric aspects of intelligence, but not with verbal intelligence. Interestingly, figural intelligence associations were dependent on sex and intelligence factor; in females, the pallidum volumes were correlated with crystallised figural intelligence (r = 0.372, p = 0.01), whereas in males, the caudate volumes were correlated with fluid figural intelligence (r = 0.507, p = 0.01). Numeric intelligence was correlated with right-lateralised caudate nucleus volumes for both females and males, but only for crystallised intelligence (r = 0.306, p = 0.04 and r = 0.459, p = 0.04, respectively). The associations were not mediated by prefrontal cortical subfield volumes when controlling with partial correlation analyses. Conclusions/Significance The findings of our exploratory analysis indicate that figural and numeric intelligence aspects, but not verbal aspects, are strongly associated with basal ganglia volumes. Unlike numeric intelligence, the type of figural intelligence appears to be related to distinct basal ganglia

  6. Holographic renormalization of 3D minimal massive gravity

    NASA Astrophysics Data System (ADS)

    Alishahiha, Mohsen; Qaemmaqami, Mohammad M.; Naseh, Ali; Shirzad, Ahmad

    2016-01-01

    We study holographic renormalization of 3D minimal massive gravity using the Chern-Simons-like formulation of the model. We explicitly present Gibbons- Hawking term as well as all counterterms needed to make the action finite in terms of dreibein and spin-connection. This can be used to find correlation functions of stress tensor of holographic dual field theory.

  7. Correlated Variability in the Breathing Pattern and End-Expiratory Lung Volumes in Conscious Humans

    PubMed Central

    Dellaca, Raffaele L.; Aliverti, Andrea; Lo Mauro, Antonella; Lutchen, Kenneth R.; Pedotti, Antonio; Suki, Bela

    2015-01-01

    In order to characterize the variability and correlation properties of spontaneous breathing in humans, the breathing pattern of 16 seated healthy subjects was studied during 40 min of quiet breathing using opto-electronic plethysmography, a contactless technology that measures total and compartmental chest wall volumes without interfering with the subjects breathing. From these signals, tidal volume (VT), respiratory time (TTOT) and the other breathing pattern parameters were computed breath-by-breath together with the end-expiratory total and compartmental (pulmonary rib cage and abdomen) chest wall volume changes. The correlation properties of these variables were quantified by detrended fluctuation analysis, computing the scaling exponentα. VT, TTOT and the other breathing pattern variables showed α values between 0.60 (for minute ventilation) to 0.71 (for respiratory rate), all significantly lower than the ones obtained for end-expiratory volumes, that ranged between 1.05 (for rib cage) and 1.13 (for abdomen) with no significant differences between compartments. The much stronger long-range correlations of the end expiratory volumes were interpreted by a neuromechanical network model consisting of five neuron groups in the brain respiratory center coupled with the mechanical properties of the respiratory system modeled as a simple Kelvin body. The model-based α for VT is 0.57, similar to the experimental data. While the α for TTOT was slightly lower than the experimental values, the model correctly predicted α for end-expiratory lung volumes (1.045). In conclusion, we propose that the correlations in the timing and amplitude of the physiological variables originate from the brain with the exception of end-expiratory lung volume, which shows the strongest correlations largely due to the contribution of the viscoelastic properties of the tissues. This cycle-by-cycle variability may have a significant impact on the functioning of adherent cells in the

  8. Ultrasonographic assessment of splenic volume and its correlation with body parameters in a Jordanian population

    PubMed Central

    Badran, Darwish H.; Kalbouneh, Heba M.; Al-Hadidi, Maher T.; Shatarat, Amjad T.; Tarawneh, Emad S.; Hadidy, Azmy M.; Mahafza, Waleed S.

    2015-01-01

    Objectives: To estimate normal linear dimensions and volume of spleen in Jordanians using ultrasonography, and to correlate splenic volume with age and body parameters: height, weight, body surface area (BSA), and body mass index (BMI). Methods: A prospective pilot study was conducted on 205 volunteers (115 males and 90 females) not known to have any conditions likely to be associated with splenomegaly. The study was performed at the Radiology Department, Jordanian University Hospital, Amman, Jordan, between December 2013 and August 2014. All linear dimensions of spleen were measured, and splenic volume (index) was calculated using the standard prolate ellipsoid formula (length × width × depth × 0.523). The splenic volume was then analyzed with age and body parameters using the Pearson’s correlation coefficient. Results: The mean (± SD) splenic dimensions were 10.72±1.37 cm in length, 7.40±1.52 cm in width, 4.40±1.47 cm in depth, and 184.15±79.56 cm3 in volume. Men had larger spleens than women (p<0.0001). Age had no significant effect on spleen volume (r=0.11, p=0.12). There was a significant moderate positive correlation (p<0.0001), using Pearson’s correlation coefficient, between the spleen volume, and other parameters (height, weight, BSA, and BMI), with correlation coefficients exceeding 0.3. Conclusion: A local reference of spleen dimensions was established with a different range of values reported previously. PMID:26219448

  9. The hippocampus and exercise: histological correlates of MR-detected volume changes.

    PubMed

    Biedermann, Sarah V; Fuss, Johannes; Steinle, Jörg; Auer, Matthias K; Dormann, Christof; Falfán-Melgoza, Claudia; Ende, Gabriele; Gass, Peter; Weber-Fahr, Wolfgang

    2016-04-01

    Growing evidence indicates that physical exercise increases hippocampal volume. This has consistently been shown in mice and men using magnetic resonance imaging. On the other hand, histological studies have reported profound alterations on a cellular level including increased adult hippocampal neurogenesis after exercise. A combined investigation of both phenomena has not been documented so far although a causal role of adult neurogenesis for increased hippocampal volume has been suggested before. We investigated 20 voluntary wheel running and 20 sedentary mice after a period of 2 month voluntary wheel running. Half of each group received focalized hippocampal irradiation to inhibit neurogenesis prior to wheel running. Structural MRI and histological investigations concerning newborn neurons (DCX), glial cells (GFAP), microglia, proliferating and pyknotic cells, neuronal activation, as well as blood vessel density and arborisation were performed. In a regression model, neurogenesis was the marker best explaining hippocampal gray matter volume. Individual analyses showed a positive correlation of gray matter volume with DCX-positive newborn neurons in the subgroups, too. GFAP-positive cells significantly interacted with gray matter volume with a positive correlation in sham-irradiated mice and no correlation in irradiated mice. Although neurogenesis appears to be an important marker of higher hippocampal gray matter volume, a monocausal relationship was not indicated, requesting further investigations. PMID:25550000

  10. Disgust and happiness recognition correlate with anteroventral insula and amygdala volume respectively in preclinical Huntington's disease.

    PubMed

    Kipps, C M; Duggins, A J; McCusker, E A; Calder, A J

    2007-07-01

    Patients with Huntington's disease (HD) can show disproportionate impairments in recognizing facial signals of disgust, but the neural basis of this deficit remains unclear. Functional imaging studies have implicated the anterior insula in the ability to recognize disgust, but have identified other structures as well, including the basal ganglia. In view of variable insula and basal ganglia volume changes in HD, we used voxel-based morphometry to map regional variations in gray matter (GM) volume in participants carrying the mutation for HD, and correlated this with their performance on a test of facial emotion recognition for six basic emotions (disgust, fear, anger, happiness, sadness, surprise). The volume of the anteroventral insula was strongly correlated with performance on the disgust recognition task. The amygdala volume (bilaterally) correlated with the ability to recognize happy facial expressions. There was marked specificity of the regional correlations for the emotion involved. Recognition of other emotion expressions, or more general cognitive or motor performance as measured by a standardized rating scale, did not correlate with regional brain volume in this group. Control participants showed no effect for any measure. The strong linear correlations for disgust and happiness recognition imply direct involvement of the anterior insula in disgust appreciation, and a similar role for the amygdala in recognizing happy facial expressions. The absence of a significant correlation with the basal ganglia suggests a less critical role for these structures in disgust recognition than has previously been suggested. The findings also highlight the role of neurodegenerative diseases combined with statistical imaging techniques in elucidating the brain basis of behavior and cognition. PMID:17583995

  11. Holographic entropy production

    NASA Astrophysics Data System (ADS)

    Tian, Yu; Wu, Xiao-Ning; Zhang, Hongbao

    2014-10-01

    The suspicion that gravity is holographic has been supported mainly by a variety of specific examples from string theory. In this paper, we propose that such a holography can actually be observed in the context of Einstein's gravity and at least a class of generalized gravitational theories, based on a definite holographic principle where neither is the bulk space-time required to be asymptotically AdS nor the boundary to be located at conformal infinity, echoing Wilson's formulation of quantum field theory. After showing the general equilibrium thermodynamics from the corresponding holographic dictionary, in particular, we provide a rather general proof of the equality between the entropy production on the boundary and the increase of black hole entropy in the bulk, which can be regarded as strong support to this holographic principle. The entropy production in the familiar holographic superconductors/superfluids is investigated as an important example, where the role played by the holographic renormalization is explained.

  12. Diffusion tensor imaging correlates with lesion volume in cerebral hemisphere infarctions

    PubMed Central

    2010-01-01

    Background Both a large lesion volume and abnormalities in diffusion tensor imaging are independently associated with a poor prognosis after cerebral infarctions. Therefore, we assume that they are associated. This study assessed the associations between lesion volumes and diffusion tensor imaging in patients with a right-sided cerebral infarction. Methods The lesion volumes of 33 patients (age 65.9 ± 8.7, 26 males and 7 females) were imaged using computed tomography (CT) in the acute phase (within 3-4 hours) and magnetic resonance imaging (MRI) in the chronic phase (follow-up at 12 months, with a range of 8-27 months). The chronic-phase fractional anisotropy (FA) and mean diffusivity (MD) values were measured at the site of the infarct and selected white matter tracts. Neurological tests in both the acute and chronic phases, and DTI lateralization were assessed with the Wilcoxon signed-rank test. The effects of thrombolytic therapy (n = 10) were assessed with the Mann-Whitney U test. The correlations between the measured parameters were analysed with Spearman's rho correlation. Bonferroni post-hoc correction was used to compensate for the familywise error rate in multiple comparisons. Results Several MD values in the right hemisphere correlated positively and FA values negatively with the lesion volumes. These correlations included both lesion area and healthy tissue. The results of the mini-mental state examination and the National Institutes of Health Stroke Scale also correlated with the lesion volume. Conclusions A larger infarct volume is associated with more pronounced tissue modifications in the chronic stage as observed with the MD and FA alterations. PMID:20849612

  13. Parental Praise Correlates with Posterior Insular Cortex Gray Matter Volume in Children and Adolescents

    PubMed Central

    Matsudaira, Izumi; Yokota, Susumu; Hashimoto, Teruo; Takeuchi, Hikaru; Asano, Kohei; Asano, Michiko; Sassa, Yuko; Taki, Yasuyuki; Kawashima, Ryuta

    2016-01-01

    A positive parenting style affects psychological and cognitive development in children. Neuroimaging studies revealed that a positive parenting style influenced brain structure in children. Parental praise is a concrete behavior observed in positive parenting. Although previous psychological studies revealed a positive effect of parental praise on children, little is known about the relationship between parental praise and brain structure in children. Thus, the purpose of the present study was to determine whether there was a correlation between the parental attitude towards praising their child and gray matter volume in the children (116 boys and 109 girls; mean age, 10.6 years old). We examined the correlation between regional gray matter volume and parental praise using voxel-based morphometry (VBM) following magnetic resonance imaging (MRI). In addition, to confirm the positive effects of parental praise, we analyzed the correlation between the frequency of parental praise and personality traits in children. We showed that the parental attitude towards praising their child was significantly and positively correlated with the gray matter volume of the left posterior insular cortex in children. Moreover, we found a significant positive correlation between parental attitude towards praising their child and the personality traits of conscientiousness and openness to experience in the children. Prior studies said that gray matter volume in the posterior insula was correlated with empathy, and the functional connectivity between this area and the amygdala was associated with emotional regulation. Furthermore, the posterior insula relates to auditory function, and therefore, was likely involved in the processing of parental praise. Considering the possibility of experience-dependent plasticity, frequent parental praise would lead to increased posterior insular gray matter volume in children. Our study is the first to elucidate the relationship between a specific

  14. Parental Praise Correlates with Posterior Insular Cortex Gray Matter Volume in Children and Adolescents.

    PubMed

    Matsudaira, Izumi; Yokota, Susumu; Hashimoto, Teruo; Takeuchi, Hikaru; Asano, Kohei; Asano, Michiko; Sassa, Yuko; Taki, Yasuyuki; Kawashima, Ryuta

    2016-01-01

    A positive parenting style affects psychological and cognitive development in children. Neuroimaging studies revealed that a positive parenting style influenced brain structure in children. Parental praise is a concrete behavior observed in positive parenting. Although previous psychological studies revealed a positive effect of parental praise on children, little is known about the relationship between parental praise and brain structure in children. Thus, the purpose of the present study was to determine whether there was a correlation between the parental attitude towards praising their child and gray matter volume in the children (116 boys and 109 girls; mean age, 10.6 years old). We examined the correlation between regional gray matter volume and parental praise using voxel-based morphometry (VBM) following magnetic resonance imaging (MRI). In addition, to confirm the positive effects of parental praise, we analyzed the correlation between the frequency of parental praise and personality traits in children. We showed that the parental attitude towards praising their child was significantly and positively correlated with the gray matter volume of the left posterior insular cortex in children. Moreover, we found a significant positive correlation between parental attitude towards praising their child and the personality traits of conscientiousness and openness to experience in the children. Prior studies said that gray matter volume in the posterior insula was correlated with empathy, and the functional connectivity between this area and the amygdala was associated with emotional regulation. Furthermore, the posterior insula relates to auditory function, and therefore, was likely involved in the processing of parental praise. Considering the possibility of experience-dependent plasticity, frequent parental praise would lead to increased posterior insular gray matter volume in children. Our study is the first to elucidate the relationship between a specific

  15. RELAP5/MOD3 code manual. Volume 4, Models and correlations

    SciTech Connect

    1995-08-01

    The RELAP5 code has been developed for best-estimate transient simulation of light water reactor coolant systems during postulated accidents. The code models the coupled behavior of the reactor coolant system and the core for loss-of-coolant accidents and operational transients such as anticipated transient without scram, loss of offsite power, loss of feedwater, and loss of flow. A generic modeling approach is used that permits simulating a variety of thermal hydraulic systems. Control system and secondary system components are included to permit modeling of plant controls, turbines, condensers, and secondary feedwater systems. RELAP5/MOD3 code documentation is divided into seven volumes: Volume I presents modeling theory and associated numerical schemes; Volume II details instructions for code application and input data preparation; Volume III presents the results of developmental assessment cases that demonstrate and verify the models used in the code; Volume IV discusses in detail RELAP5 models and correlations; Volume V presents guidelines that have evolved over the past several years through the use of the RELAP5 code; Volume VI discusses the numerical scheme used in RELAP5; and Volume VII presents a collection of independent assessment calculations.

  16. Holographic Chern-Simons defects

    NASA Astrophysics Data System (ADS)

    Fujita, Mitsutoshi; Melby-Thompson, Charles M.; Meyer, René; Sugimoto, Shigeki

    2016-06-01

    We study SU( N ) Yang-Mills-Chern-Simons theory in the presence of defects that shift the Chern-Simons level from a holographic point of view by embedding the system in string theory. The model is a D3-D7 system in Type IIB string theory, whose gravity dual is given by the AdS soliton background with probe D7 branes attaching to the AdS boundary along the defects. We holographically renormalize the free energy of the defect system with sources, from which we obtain the correlation functions for certain operators naturally associated to these defects. We find interesting phase transitions when the separation of the defects as well as the temperature are varied. We also discuss some implications for the Fractional Quantum Hall Effect and for 2-dimensional QCD.

  17. Interactive holographic display

    NASA Astrophysics Data System (ADS)

    Son, Jung-Young; Lee, Beam-Ryeol; Kim, Jin-Woong; Chernyshov, Oleksii O.; Park, Min-Chul

    2014-06-01

    A holographic display which is capable of displaying floating holographic images is introduced. The display is for user interaction with the image on the display. It consists of two parts; multiplexed holographic image generation and a spherical mirror. The time multiplexed image from 2 X 10 DMD frames appeared on PDLC screen is imaged by the spherical mirror and becomes a floating image. This image is combined spatially with two layered TV images appearing behind. Since the floating holographic image has a real spatial position and depth, it allows a user to interact with the image.

  18. Correlation between Changes in Seismicity Rates and Well Injection Volumes in Oklahoma

    NASA Astrophysics Data System (ADS)

    Gupta, A.; Baker, J.; Walsh, R.; Zoback, M. D.

    2015-12-01

    We present a statistical approach to establish correlations between locations with seismicity increase in Oklahoma and nearby well injection volumes. Seismicity rates in the state have significantly increased since approximately 2008. Fluid injection into deep wells has been theorized to be the cause of this seismicity, but the increase occurred significantly after the start of injection activities in the region. Further, injection-induced earthquakes depend on the presence and orientation of basement faults and the stress state in the region. Because of these complexities, it has been difficult to directly correlate fluid injection with seismicity. Here we show that a statistical correlation between increase in seismicity and injection volumes can be established in Oklahoma. We first employ a change point method to locate the regions where a change in seismicity rates has occurred. We then use a logistic regression model to relate the injection volumes in a region with the presence or absence of seismicity change in the region. This model is further used to evaluate the relative contribution of cumulative injection volumes and monthly injection rates to seismicity. The model can be used to identify "seismically sensitive regions" where seismicity increase has been observed with little fluid injection, and "seismically stable regions" where seismicity changes have not been observed even with high fluid injection. This information can be combined with geological information in a region, and used to make decisions about acceptable volumes for injection and to identify lower-risk regions for injection.

  19. Correlation between Gray/White Matter Volume and Cognition in Healthy Elderly People

    ERIC Educational Resources Information Center

    Taki, Yasuyuki; Kinomura, Shigeo; Sato, Kazunori; Goto, Ryoi; Wu, Kai; Kawashima, Ryuta; Fukuda, Hiroshi

    2011-01-01

    This study applied volumetric analysis and voxel-based morphometry (VBM) of brain magnetic resonance (MR) images to assess whether correlations exist between global and regional gray/white matter volume and the cognitive functions of semantic memory and short-term memory, which are relatively well preserved with aging, using MR image data from 109…

  20. Applications of holographic spacetime

    NASA Astrophysics Data System (ADS)

    Torres, Terrence J.

    Here we present an overview of the theory of holographic spacetime (HST), originally devised and primarily developed by Tom Banks and Willy Fischler, as well as its various applications and predictions for cosmology and particle phenomenology. First we cover the basic theory and motivation for holographic spacetime and move on to present the latest developments therein as of the time of this writing. Then we indicate the origin of the quantum degrees of freedom in the theory and then present a correspondence with low energy effective field theory. Further, we proceed to show the general origins of inflation and the cosmic microwave background (CMB) within the theory of HST as well as predict the functional forms of two and three point correlation functions for scalar and tensor curvature fluctuations in the early universe. Next, we constrain the theory parameters by insisting on agreement with observational bounds on the scalar spectral index of CMB fluctuations from the Planck experiment as well as theoretical bounds on the number of e-folds of inflation. Finally, we argue that HST predicts specific gauge structures for the low-energy effective field theory at the present era and proceed to construct a viable supersymmetric model extension. Constraints on model parameters and couplings are then calculated by numerically minimizing the theory's scalar potential and comparing the resultant model mass spectra to current observational limits from the LHC SUSY searches. In the end we find that the low-energy theory, while presenting a little hierarchy problem, is fully compatible with current observational limits. Additionally, the high-energy underlying theory is generically compatible with observational constraints stemming from inflation, and predictions on favored model parameters are given.

  1. Beam shaping for holographic techniques

    NASA Astrophysics Data System (ADS)

    Laskin, Alexander; Laskin, Vadim; Ostrun, Aleksei

    2014-09-01

    Uniform intensity of laser radiation is very important in holographic and interferometry technologies, therefore transformation of typical Gaussian distribution of a TEM00 laser to flat-top (top hat) is an actual technical task, it is solved by applying beam shaping optics. Holography and interferometry have specific requirements to a uniform laser beam, most important of them are flatness of phase front and extended depth of field. There are different refractive and diffractive beam shaping approaches used in laser industrial and scientific applications, but only few of them are capable to fulfil the optimum conditions for beam quality demanding holography and interferometry. We suggest applying refractive field mapping beam shapers piShaper, which operational principle presumes almost lossless transformation of Gaussian to flat-top beam with flatness of output wavefront, conserving of beam consistency, providing collimated low divergent output beam, high transmittance, extended depth of field, negligible wave aberration, and achromatic design provides capability to work with several lasers with different wavelengths simultaneously. This approach is used in SLM-based technologies of Computer Generated Holography, Dot-Matrix mastering of security holograms, holographic data storage, holographic projection, lithography, interferometric recording of Volume Bragg Gratings. High optical quality of resulting flat-top beam allows applying additional optical components to vary beam size and shape, thus adapting an optical system to requirements of a particular application. This paper will describe design basics of refractive beam shapers and optical layouts of their applying in holographic systems. Examples of real implementations and experimental results will be presented as well.

  2. Improving the clinical correlation of multiple sclerosis black hole volume change by paired-scan analysis.

    PubMed

    Tam, Roger C; Traboulsee, Anthony; Riddehough, Andrew; Li, David K B

    2012-01-01

    The change in T 1-hypointense lesion ("black hole") volume is an important marker of pathological progression in multiple sclerosis (MS). Black hole boundaries often have low contrast and are difficult to determine accurately and most (semi-)automated segmentation methods first compute the T 2-hyperintense lesions, which are a superset of the black holes and are typically more distinct, to form a search space for the T 1w lesions. Two main potential sources of measurement noise in longitudinal black hole volume computation are partial volume and variability in the T 2w lesion segmentation. A paired analysis approach is proposed herein that uses registration to equalize partial volume and lesion mask processing to combine T 2w lesion segmentations across time. The scans of 247 MS patients are used to compare a selected black hole computation method with an enhanced version incorporating paired analysis, using rank correlation to a clinical variable (MS functional composite) as the primary outcome measure. The comparison is done at nine different levels of intensity as a previous study suggests that darker black holes may yield stronger correlations. The results demonstrate that paired analysis can strongly improve longitudinal correlation (from -0.148 to -0.303 in this sample) and may produce segmentations that are more sensitive to clinically relevant changes. PMID:24179734

  3. Correlation between T-Wave Alternans and Cardiac Volume Status via Intrathoracic Impedance Measurements.

    PubMed

    Dizon, Jose'; Hickey, Kathleen; Garan, Hasan

    2012-01-01

    Introduction. The presence of T-wave alternans (TWA) has been shown to correlate with a higher risk for sudden cardiac death. The mechanism of TWA may be related to abnormalities in intracellular calcium handling, which is a mechanism in heart failure and associated arrhythmias as well. However, an association between TWA and cardiac volume status has not been demonstrated. Methods Used. We report the case of a 54-year-old man with a dilated cardiomyopathy who had a biventricular defibrillator system implanted with intrathoracic impedance measurement capability. We performed baseline TWA testing, which was normal and was associated with normal clinical status and normal intrathoracic impedance. We followed intrathoracic impedance measurements, and when the measurement suggested volume overload eight months later, we repeated the TWA test. TWA was grossly positive, and volume overload was corroborated with clinical heart failure. The patient was diuresed, and when clinical status and intrathoracic impedance returned to normal a month later, we repeated TWA, which was again negative. Conclusion. This case demonstrates a correlation between cardiac volume status, as measured by intrathoracic impedance measurements, and TWA status. This data suggests that conditions of volume overload such as heart failure could be causally related to increased TWA, perhaps by the common mechanism of altered intracellular calcium handling. PMID:24826235

  4. Correlation between T-Wave Alternans and Cardiac Volume Status via Intrathoracic Impedance Measurements

    PubMed Central

    Dizon, Jose'; Hickey, Kathleen; Garan, Hasan

    2012-01-01

    Introduction. The presence of T-wave alternans (TWA) has been shown to correlate with a higher risk for sudden cardiac death. The mechanism of TWA may be related to abnormalities in intracellular calcium handling, which is a mechanism in heart failure and associated arrhythmias as well. However, an association between TWA and cardiac volume status has not been demonstrated. Methods Used. We report the case of a 54-year-old man with a dilated cardiomyopathy who had a biventricular defibrillator system implanted with intrathoracic impedance measurement capability. We performed baseline TWA testing, which was normal and was associated with normal clinical status and normal intrathoracic impedance. We followed intrathoracic impedance measurements, and when the measurement suggested volume overload eight months later, we repeated the TWA test. TWA was grossly positive, and volume overload was corroborated with clinical heart failure. The patient was diuresed, and when clinical status and intrathoracic impedance returned to normal a month later, we repeated TWA, which was again negative. Conclusion. This case demonstrates a correlation between cardiac volume status, as measured by intrathoracic impedance measurements, and TWA status. This data suggests that conditions of volume overload such as heart failure could be causally related to increased TWA, perhaps by the common mechanism of altered intracellular calcium handling. PMID:24826235

  5. Holographic display for see-through augmented reality using mirror-lens holographic optical element.

    PubMed

    Li, Gang; Lee, Dukho; Jeong, Youngmo; Cho, Jaebum; Lee, Byoungho

    2016-06-01

    A holographic display system for realizing a three-dimensional optical see-through augmented reality (AR) is proposed. A multi-functional holographic optical element (HOE), which simultaneously performs the optical functions of a mirror and a lens, is adopted in the system. In the proposed method, a mirror that is used to guide the light source into a reflection type spatial light modulator (SLM) and a lens that functions as Fourier transforming optics are recorded on a single holographic recording material by utilizing an angular multiplexing technique of volume hologram. The HOE is transparent and performs the optical functions just for Bragg matched condition. Therefore, the real-world scenes that are usually distorted by a Fourier lens or an SLM in the conventional holographic display can be observed without visual disturbance by using the proposed mirror-lens HOE (MLHOE). Furthermore, to achieve an optimized optical recording condition of the MLHOE, the optical characteristics of the holographic material are measured. The proposed holographic AR display system is verified experimentally. PMID:27244395

  6. Holographic Complexity Equals Bulk Action?

    NASA Astrophysics Data System (ADS)

    Brown, Adam R.; Roberts, Daniel A.; Susskind, Leonard; Swingle, Brian; Zhao, Ying

    2016-05-01

    We conjecture that the quantum complexity of a holographic state is dual to the action of a certain spacetime region that we call a Wheeler-DeWitt patch. We illustrate and test the conjecture in the context of neutral, charged, and rotating black holes in anti-de Sitter spacetime, as well as black holes perturbed with static shells and with shock waves. This conjecture evolved from a previous conjecture that complexity is dual to spatial volume, but appears to be a major improvement over the original. In light of our results, we discuss the hypothesis that black holes are the fastest computers in nature.

  7. Three Dimensional Holographic Archival Memory

    SciTech Connect

    Gibbard, Bruce

    2006-11-09

    To address the DOE need for the storage and handling of terabyte of nuclear physics data, Physical Optics Corporation (POC) developed a new multi-terabit, 90° recording geometry 3D holographic archival optical memory storage and search system. In contrast to state-of-the-art memory approaches, 3DHAM handles the data through highly parallel optical processing in conjunction with highly redundant hologram multiplexing. The 3DHAM system advantages also stem from its unique 3D volume-recording medium, which theoretically has a significantly greater data density than diskbased systems.

  8. Holographic Complexity Equals Bulk Action?

    PubMed

    Brown, Adam R; Roberts, Daniel A; Susskind, Leonard; Swingle, Brian; Zhao, Ying

    2016-05-13

    We conjecture that the quantum complexity of a holographic state is dual to the action of a certain spacetime region that we call a Wheeler-DeWitt patch. We illustrate and test the conjecture in the context of neutral, charged, and rotating black holes in anti-de Sitter spacetime, as well as black holes perturbed with static shells and with shock waves. This conjecture evolved from a previous conjecture that complexity is dual to spatial volume, but appears to be a major improvement over the original. In light of our results, we discuss the hypothesis that black holes are the fastest computers in nature. PMID:27232013

  9. Photopolymeric multifunctional dendrimer toward holographic applications.

    PubMed

    Jeong, Yong-Cheol; Jung, Bokyung; Park, Jung-Ki

    2012-09-26

    We present a photopolymeric multifunctional dendrimer for holographic applications. In this study, we described a synthesis of multiphotoreactive dendrimer and phase compatible polymer matrix as well as a numerical simulation of the dendrimer. This holographic photopolymer containing a nanosized photoreactive organic dendrimer could address the aggregation issue of conventional inorganic nanoparticle additives and allowed writing-induced shrinkage to be successfully reduced to the extent of acceptable values for 130 μm thick film. In this report, holographic performance including diffraction efficiency (DE), transmission, photosensitivity, modulation of refractive index, polarization sensitivity, and volume shrinkage has been discussed. The page-wise recording by using an amplitude spatial light modulator (SLM) was also demonstrated. PMID:22950741

  10. The correlation between emotional intelligence and gray matter volume in university students.

    PubMed

    Tan, Yafei; Zhang, Qinglin; Li, Wenfu; Wei, Dongtao; Qiao, Lei; Qiu, Jiang; Hitchman, Glenn; Liu, Yijun

    2014-11-01

    A number of recent studies have investigated the neurological substrates of emotional intelligence (EI), but none of them have considered the neural correlates of EI that are measured using the Schutte Self-Report Emotional Intelligence Scale (SSREIS). This scale was developed based on the EI model of Salovey and Mayer (1990). In the present study, SSREIS was adopted to estimate EI. Meanwhile, magnetic resonance imaging (MRI) and voxel-based morphometry (VBM) were used to evaluate the gray matter volume (GMV) of 328 university students. Results found positive correlations between Monitor of Emotions and VBM measurements in the insula and orbitofrontal cortex. In addition, Utilization of Emotions was positively correlated with the GMV in the parahippocampal gyrus, but was negatively correlated with the VBM measurements in the fusiform gyrus and middle temporal gyrus. Furthermore, Social Ability had volume correlates in the vermis. These findings indicate that the neural correlates of the EI model, which primarily focuses on the abilities of individuals to appraise and express emotions, can also regulate and utilize emotions to solve problems. PMID:25282329

  11. High speed optical object recognition processor with massive holographic memory

    NASA Technical Reports Server (NTRS)

    Chao, T.; Zhou, H.; Reyes, G.

    2002-01-01

    Real-time object recognition using a compact grayscale optical correlator will be introduced. A holographic memory module for storing a large bank of optimum correlation filters, to accommodate the large data throughput rate needed for many real-world applications, has also been developed. System architecture of the optical processor and the holographic memory will be presented. Application examples of this object recognition technology will also be demonstrated.

  12. Experimental approach toward holographic interferometric fringe interpretation

    NASA Technical Reports Server (NTRS)

    Liu, H. K.

    1974-01-01

    Current literature concerning the measurement of small displacements by the laser holographic technique was reviewed. It was found that existing theories are extremely difficult, if not impossible, to apply to any realistic nondestructive testing conditions in which the geometries of the objects are complex and the three-dimensional displacements are irregular. An experimental approach was adopted for interpreting correlation between real time holographic fringe patterns and small displacements. Preliminary results show that the present method is feasible for the quantitative interpretation of the fringes as well as the calibration of the mobile HNDT system.

  13. Improved scattering screen for a multiplanar volumetric holographic display

    NASA Astrophysics Data System (ADS)

    Takano, Kunihiko; Sato, Koki; Ohki, Makoto

    2011-09-01

    As a technique for displaying holographic three-dimensional (3D) images in the wide region with a wide viewing angle, spatial projecting technique onto the mist screen is well-known. For such purposes, other various techniques have been studied, however, it has been difficult to take a side view of 3D images. In order to overcome this problem, we have been challenged to improve a holographic 3D displaying system employing a mist screen. In this paper, we shall report a new display system which has an improved jetting mechanism compensating the characteristics of the mist screen and gives volumeful 3D images by combining the reconstructed waves from two ways. It is also shown that by the use of this system, we can better observe 3D images in the wider viewing region than before. From this, we confirmed the possibility of a holographic projecting process adopted mist screen displaying volumeful 3D holographic images.

  14. Full Color Holographic Endoscopy

    NASA Astrophysics Data System (ADS)

    Osanlou, A.; Bjelkhagen, H.; Mirlis, E.; Crosby, P.; Shore, A.; Henderson, P.; Napier, P.

    2013-02-01

    The ability to produce color holograms from the human tissue represents a major medical advance, specifically in the areas of diagnosis and teaching. This has been achieved at Glyndwr University. In corporation with partners at Gooch & Housego, Moor Instruments, Vivid Components and peninsula medical school, Exeter, UK, for the first time, we have produced full color holograms of human cell samples in which the cell boundary and the nuclei inside the cells could be clearly focused at different depths - something impossible with a two-dimensional photographic image. This was the main objective set by the peninsula medical school at Exeter, UK. Achieving this objective means that clinically useful images essentially indistinguishable from the object human cells could be routinely recorded. This could potentially be done at the tip of a holo-endoscopic probe inside the body. Optimised recording exposure and development processes for the holograms were defined for bulk exposures. This included the optimisation of in-house recording emulsions for coating evaluation onto polymer substrates (rather than glass plates), a key step for large volume commercial exploitation. At Glyndwr University, we also developed a new version of our in-house holographic (world-leading resolution) emulsion.

  15. Voxel-based morphometry in eating disorders: correlation of psychopathology with grey matter volume.

    PubMed

    Joos, Andreas; Klöppel, Stefan; Hartmann, Armin; Glauche, Volkmar; Tüscher, Oliver; Perlov, Evgeniy; Saum, Barbara; Freyer, Tobias; Zeeck, Almut; Tebartz van Elst, Ludger

    2010-05-30

    Twenty-nine adult female patients with eating disorders (17 with bulimia nervosa, 12 with restrictive anorexia nervosa) were compared with 18 age-matched female healthy controls, using voxel-based morphometry. Restrictive anorexia nervosa patients showed a decrease of grey matter, particularly affecting the anterior cingulate cortex, frontal operculum, temporoparietal regions and the precuneus. By contrast, patients with bulimia nervosa did not differ from healthy controls. A positive correlation of "drive for thinness" and grey matter volume of the right inferior parietal lobe was found for both eating disorder groups. The strong reduction of grey matter volume in adult patients with restrictive anorexia nervosa is in line with results of adolescent patients. Contrary to other studies, this first voxel-based morphometry report of bulimic patients did not find any structural abnormalities. The inferior parietal cortex is a critical region for sensory integration of body and spatial perception, and the correlation of "drive for thinness" with grey matter volume of this region points to a neural correlate of this core psychopathological feature of eating disorders. PMID:20400273

  16. Holographic thermalization with Weyl corrections

    NASA Astrophysics Data System (ADS)

    Dey, Anshuman; Mahapatra, Subhash; Sarkar, Tapobrata

    2016-01-01

    We consider holographic thermalization in the presence of a Weyl correction in five dimensional AdS space. We first obtain the Weyl corrected black brane solution perturbatively, up to first order in the coupling. The corresponding AdS-Vaidya like solution is then constructed. This is then used to numerically analyze the time dependence of the two point correlation functions and the expectation values of rectangular Wilson loops in the boundary field theory, and we discuss how the Weyl correction can modify the thermalization time scales in the dual field theory. In this context, the subtle interplay between the Weyl coupling constant and the chemical potential is studied in detail.

  17. Brain tissue volume changes in relapsing-remitting multiple sclerosis: correlation with lesion load.

    PubMed

    Quarantelli, Mario; Ciarmiello, Andrea; Morra, Vincenzo Brescia; Orefice, Giuseppe; Larobina, Michele; Lanzillo, Roberta; Schiavone, Vittorio; Salvatore, Elena; Alfano, Bruno; Brunetti, Arturo

    2003-02-01

    The aim of this study was to simultaneously measure in vivo volumes of gray matter (GM), normal white matter (WM), abnormal white matter (aWM), and cerebro-spinal fluid (CSF), and to assess their relationship in 50 patients with relapsing-remitting multiple sclerosis (RR-MS) (age range, 21-59; mean EDSS, 2.5; mean disease duration, 9.9 years), using an unsupervised multiparametric segmentation procedure applied to brain MR studies. Tissue volumes were normalized to total intracranial volume providing corresponding fractional volumes (fGM, faWM, fWM, and fCSF), subsequently corrected for aWM-related segmentation inaccuracies and adjusted to mean patients' age according to age-related changes measured in 54 normal volunteers (NV) (age range 16-70). In MS patients aWM was 23.8 +/- 29.8 ml (range 0.4-138.8). A significant decrease in fGM was present in MS patients as compared to NV (49.5 +/- 3.2% vs 53.3 +/- 2.1%; P < 0.0001), with a corresponding increase in fCSF (13.0 +/- 3.8% vs 9.1 +/- 2.4%; P < 0.0001). No difference could be detected between the two groups for fWM (37.5 +/- 2.6% vs 37.6 +/- 2.2%). faWM correlated inversely with fGM (R = -0.434, P < 0.001 at regression analysis), and directly with fCSF (R = 0.473, P < 0.001), but not with fWM. There was a significant correlation between disease duration and EDSS, while no relationship was found between EDSS or disease duration and fractional volumes. Brain atrophy in RR-MS is mainly related to GM loss, which correlates with faWM. Both measures do not appear to significantly affect EDSS, which correlates to disease duration. PMID:12595189

  18. Permanent holographic storage medium

    NASA Technical Reports Server (NTRS)

    Gange, R. A.

    1976-01-01

    Storage unit is electrostatically-charged multilayered laminate. Ability of system to store information in holographic forms is due to specific electrical, optical, and chemical characteristics of its materials.

  19. A Holographic Road Show.

    ERIC Educational Resources Information Center

    Kirkpatrick, Larry D.; Rugheimer, Mac

    1979-01-01

    Describes the viewing sessions and the holograms of a holographic road show. The traveling exhibits, believed to stimulate interest in physics, include a wide variety of holograms and demonstrate several physical principles. (GA)

  20. Gray matter alterations and correlation of nutritional intake with the gray matter volume in prediabetes

    PubMed Central

    Hou, Yi-Cheng; Lai, Chien-Han; Wu, Yu-Te; Yang, Shwu-Huey

    2016-01-01

    Abstract The neurophysiology of prediabetes plays an important role in preventive medicine. The dysregulation of glucose metabolism is likely linked to changes in neuron-related gray matter. Therefore, we designed this study to investigate gray matter alterations in medication-naive prediabetic patients. We expected to find alterations in the gray matter of prediabetic patients. A total of 64 prediabetic patients and 54 controls were enrolled. All subjects received T1 scans using a 3-T magnetic resonance imaging machine. Subjects also completed nutritional intake records at the 24-hour and 3-day time points to determine their carbohydrate, protein, fat, and total calorie intake. We utilized optimized voxel-based morphometry to estimate the gray matter differences between the patients and controls. In addition, the preprandial serum glucose level and the carbohydrate, protein, fat, and total calorie intake levels were tested to determine whether these parameters were correlated with the gray matter volume. Prediabetic patients had lower gray matter volumes than controls in the right anterior cingulate gyrus, right posterior cingulate gyrus, left insula, left super temporal gyrus, and left middle temporal gyrus (corrected P < 0.05; voxel threshold: 33). Gray matter volume in the right anterior cingulate was also negatively correlated with the preprandial serum glucose level gyrus in a voxel-dependent manner (r = –0.501; 2-tailed P = 0.001). The cingulo-temporal and insula gray matter alterations may be associated with the glucose dysregulation in prediabetic patients. PMID:27336893

  1. Gray matter alterations and correlation of nutritional intake with the gray matter volume in prediabetes.

    PubMed

    Hou, Yi-Cheng; Lai, Chien-Han; Wu, Yu-Te; Yang, Shwu-Huey

    2016-06-01

    The neurophysiology of prediabetes plays an important role in preventive medicine. The dysregulation of glucose metabolism is likely linked to changes in neuron-related gray matter. Therefore, we designed this study to investigate gray matter alterations in medication-naive prediabetic patients. We expected to find alterations in the gray matter of prediabetic patients.A total of 64 prediabetic patients and 54 controls were enrolled. All subjects received T1 scans using a 3-T magnetic resonance imaging machine. Subjects also completed nutritional intake records at the 24-hour and 3-day time points to determine their carbohydrate, protein, fat, and total calorie intake. We utilized optimized voxel-based morphometry to estimate the gray matter differences between the patients and controls. In addition, the preprandial serum glucose level and the carbohydrate, protein, fat, and total calorie intake levels were tested to determine whether these parameters were correlated with the gray matter volume.Prediabetic patients had lower gray matter volumes than controls in the right anterior cingulate gyrus, right posterior cingulate gyrus, left insula, left super temporal gyrus, and left middle temporal gyrus (corrected P < 0.05; voxel threshold: 33). Gray matter volume in the right anterior cingulate was also negatively correlated with the preprandial serum glucose level gyrus in a voxel-dependent manner (r = -0.501; 2-tailed P = 0.001).The cingulo-temporal and insula gray matter alterations may be associated with the glucose dysregulation in prediabetic patients. PMID:27336893

  2. Digital Holographic Logic

    NASA Technical Reports Server (NTRS)

    Preston, K., Jr.

    1972-01-01

    The characteristics of the holographic logic computer are discussed. The holographic operation is reviewed from the Fourier transform viewpoint, and the formation of holograms for use in performing digital logic are described. The operation of the computer with an experiment in which the binary identity function is calculated is discussed along with devices for achieving real-time performance. An application in pattern recognition using neighborhood logic is presented.

  3. Characteristic free volumes of bulk metallic glasses: Measurement and their correlation with glass-forming ability

    SciTech Connect

    Hu Qiang; Zeng Xierong; Fu, M. W.

    2011-03-01

    A convenient method is proposed for the measurement of the characteristic free volumes, viz., the amount of excess free volume annihilation in structural relaxation V{sub f-sr} and the amount of new free volume production in glass transition V{sub f-gt} of bulk metallic glasses (BMGs) by thermal dilation (DIL) test. Through the DIL tests, the characteristic free volumes are found to be sensitive to the change of glass forming ability (GFA). The Pd{sub 40}Cu{sub 30}Ni{sub 10}P{sub 20} BMG has a quite small V{sub f-sr}. For a series of Fe-Cr-Mo-C-B-(Er) BMGs, Fe{sub 48}Cr{sub 15}Mo{sub 14}C{sub 15}B{sub 6}Er{sub 2} with the largest GFA is identified to have the largest V{sub f-gt} and smallest V{sub f-sr}. The correlation between V{sub f-sr} and the squares of critical diameters of these iron-based BMGs can be fitted as a negative exponential function with high accuracy.

  4. Self-reported impulsivity is negatively correlated with amygdalar volumes in cocaine dependence.

    PubMed

    Mei, Songli; Xu, Jiansong; Carroll, Kathleen M; Potenza, Marc N

    2015-08-30

    Although impulsivity has been associated with cocaine dependence and other addictive behaviors, the biological factors underlying impulsivity have yet to be precisely determined. This study aimed to examine relationships between impulsivity and volumes of the amygdala and hippocampus in cocaine-dependent and healthy comparison individuals. The Barratt Impulsiveness Scale (BIS-11) was used to assess impulsivity. FreeSurfer was used to assess amygdalar and hippocampal volumes from high-resolution structural magnetic resonance images. Relative to healthy comparison subjects, cocaine-dependent individuals scored higher on all three subscales of BIS-11 but did not differ from healthy comparison subjects in amygdalar or hippocampal volumes. Cocaine-dependent individuals showed significant negative correlations between amygdalar volumes and scores on the BIS-11 Attentional subscale, and this relationship differed significantly from the non-significant relationship in healthy comparison subjects. As individual differences in amygdalar structure may contribute to the high impulsivity observed in cocaine-dependent individuals, the findings suggest that future studies should assess the extent to which therapies that target impulsivity in cocaine dependence may operate through the amygdala or alter its structure or function. PMID:26187551

  5. Correlation of neurocognitive function and brain parenchyma volumes in children surviving cancer

    NASA Astrophysics Data System (ADS)

    Reddick, Wilburn E.; White, Holly A.; Glass, John O.; Mulhern, Raymond K.

    2002-04-01

    This research builds on our hypothesis that white matter damage and associated neurocognitive symptoms, in children treated for cancer with cranial spinal irradiation, spans a continuum of severity that can be reliably probed using non-invasive MR technology. Quantitative volumetric assessments of MR imaging and psychological assessments were obtained in 40 long-term survivors of malignant brain tumors treated with cranial irradiation. Neurocognitive assessments included a test of intellect (Wechsler Intelligence Test for Children, Wechsler Adult Intelligence Scale), attention (Conner's Continuous Performance Test), and memory (California Verbal Learning Test). One-sample t-tests were conducted to evaluate test performance of survivors against age-adjusted scores from the test norms; these analyses revealed significant impairments in all apriori selected measures of intelligence, attention, and memory. Partial correlation analyses were performed to assess the relationships between brain tissues volumes (normal appearing white matter (NAWM), gray matter, and CSF) and neurocognitive function. Global intelligence (r = 0.32, p = 0.05) and global attentional (r = 0.49, p < 0.01) were significantly positively correlated with NAWM volumes, whereas global memory was significantly positively correlated with overall brain parenchyma (r = 0.38, p = 0.04). We conclude that quantitative assessment of MR examinations in survivors of childhood cancer treated with cranial irradiation reveal that loss of NAWM is associated with decreased intellectual and attentional deficits, whereas overall parenchyma loss, as reflected by increased CSF and decreased white matter, is associated with memory-related deficits.

  6. Use of PCA in Tephra Correlation and Importance of Thickness Values for Volume Estimation

    NASA Astrophysics Data System (ADS)

    Bursik, M. I.; Pouget, S.; Cortes, J. A.

    2014-12-01

    Discontinuous tephra layers were discovered at Burney Spring Mountain, northern California, USA. Stratigraphic relationships suggest that they are two distinct primary fall deposits. Geochemistry of the tephras from electron probe microanalysis was compared with geochemistry of known layers found in the region, to test for potential correlations, first using traditional binary plots and standard similarity coefficients. Then, using principal component analysis, we were able to bound our uncertainty in the correlation of the two tephra layers. After removal of outliers, within the 95% prediction interval, we can say that the lower tephra layer is likely the Rockland tephra, aged 565-610 ka, and the upper layer is likely from Mt Mazama, the Trego Hot Springs tephra, aged ~ 29 ka, based on the majority of the glass shards. The results were used to estimate the erupted volumes of the two deposits, by using the new thickness measurement together with others in the literature. The volume of the Rockland tephra was estimated to be 150-250 cu km, and of the Trego Hot Springs tephra, 10-50 cu km. It was found, however, that reported thickness measurements are not always detailed, and some reworked material is often included in measurements. As a result, the erupted volumes may be greatly over-estimated. Checking measured thickness against expected (model) thickness as a function of isopach area can provide useful information about potential redeposition. This would avoid an over-estimation of primary fall deposit volume, by giving an indication about locations where the original description should be studied in detailed and new thickness measurements made, if possible.

  7. Hippocampal volume correlates with attenuated negative psychotic symptoms irrespective of antidepressant medication

    PubMed Central

    Bernasconi, Raffaele; Smieskova, Renata; Schmidt, André; Harrisberger, Fabienne; Raschle, Nora Maria; Lenz, Claudia; Walter, Anna; Simon, Andor; Riecher-Rössler, Anita; Radue, Ernst-Wilhelm; Lang, Undine E.; Fusar-Poli, Paolo; Borgwardt, Stefan J.

    2015-01-01

    Background Individuals with at-risk mental state for psychosis (ARMS) often suffer from depressive and anxiety symptoms, which are clinically similar to the negative symptomatology described for psychosis. Thus, many ARMS individuals are already being treated with antidepressant medication. Objectives To investigate clinical and structural differences between psychosis high-risk individuals with or without antidepressants. Methods We compared ARMS individuals currently receiving antidepressants (ARMS-AD; n = 18), ARMS individuals not receiving antidepressants (ARMS-nonAD; n = 31) and healthy subjects (HC; n = 24), in terms of brain structure abnormalities, using voxel-based morphometry. We also performed region of interest analysis for the hippocampus, anterior cingulate cortex, amygdala and precuneus. Results The ARMS-AD had higher ‘depression’ and lower ‘motor hyperactivity’ scores than the ARMS-nonAD. Compared to HC, there was significantly less GMV in the middle frontal gyrus in the whole ARMS cohort and in the superior frontal gyrus in the ARMS-AD subgroup. Compared to ARMS-nonAD, the ARMS-AD group showed more gray matter volume (GMV) in the left superior parietal lobe, but less GMV in the left hippocampus and the right precuneus. We found a significant negative correlation between attenuated negative symptoms and hippocampal volume in the whole ARMS cohort. Conclusion Reduced GMV in the hippocampus and precuneus is associated with short-term antidepressant medication and more severe depressive symptoms. Hippocampal volume is further negatively correlated with attenuated negative psychotic symptoms. Longitudinal studies are needed to distinguish whether hippocampal volume deficits in the ARMS are related to attenuated negative psychotic symptoms or to antidepressant action. PMID:26110110

  8. Correlation between intra-abdominal pressure and pulmonary volumes after superior and inferior abdominal surgery

    PubMed Central

    de Cleva, Roberto; de Assumpção, Marianna Siqueira; Sasaya, Flavia; Chaves, Natalia Zuniaga; Santo, Marco Aurelio; Fló, Claudia; Lunardi, Adriana C.; Filho, Wilson Jacob

    2014-01-01

    OBJECTIVE: Patients undergoing abdominal surgery are at risk for pulmonary complications. The principal cause of postoperative pulmonary complications is a significant reduction in pulmonary volumes (FEV1 and FVC) to approximately 65-70% of the predicted value. Another frequent occurrence after abdominal surgery is increased intra-abdominal pressure. The aim of this study was to correlate changes in pulmonary volumes with the values of intra-abdominal pressure after abdominal surgery, according to the surgical incision in the abdomen (superior or inferior). METHODS: We prospectively evaluated 60 patients who underwent elective open abdominal surgery with a surgical time greater than 240 minutes. Patients were evaluated before surgery and on the 3rd postoperative day. Spirometry was assessed by maximal respiratory maneuvers and flow-volume curves. Intra-abdominal pressure was measured in the postoperative period using the bladder technique. RESULTS: The mean age of the patients was 56±13 years, and 41.6% 25 were female; 50 patients (83.3%) had malignant disease. The patients were divided into two groups according to the surgical incision (superior or inferior). The lung volumes in the preoperative period showed no abnormalities. After surgery, there was a significant reduction in both FEV1 (1.6±0.6 L) and FVC (2.0±0.7 L) with maintenance of FEV1/FVC of 0.8±0.2 in both groups. The maximum intra-abdominal pressure values were similar (p = 0.59) for the two groups. There was no association between pulmonary volumes and intra-abdominal pressure measured in any of the groups analyzed. CONCLUSIONS: Our results show that superior and inferior abdominal surgery determines hypoventilation, unrelated to increased intra-abdominal pressure. Patients at high risk of pulmonary complications should receive respiratory care even if undergoing inferior abdominal surgery. PMID:25029580

  9. Finite volume and asymptotic methods for stochastic neuron models with correlated inputs.

    PubMed

    Rosenbaum, Robert; Marpeau, Fabien; Ma, Jianfu; Barua, Aditya; Josić, Krešimir

    2012-07-01

    We consider a pair of stochastic integrate and fire neurons receiving correlated stochastic inputs. The evolution of this system can be described by the corresponding Fokker-Planck equation with non-trivial boundary conditions resulting from the refractory period and firing threshold. We propose a finite volume method that is orders of magnitude faster than the Monte Carlo methods traditionally used to model such systems. The resulting numerical approximations are proved to be accurate, nonnegative and integrate to 1. We also approximate the transient evolution of the system using an Ornstein-Uhlenbeck process, and use the result to examine the properties of the joint output of cell pairs. The results suggests that the joint output of a cell pair is most sensitive to changes in input variance, and less sensitive to changes in input mean and correlation. PMID:21717104

  10. Holographic conformal partial waves as gravitational open Wilson networks

    NASA Astrophysics Data System (ADS)

    Bhatta, Atanu; Raman, Prashanth; Suryanarayana, Nemani V.

    2016-06-01

    We propose a method to holographically compute the conformal partial waves in any decomposition of correlation functions of primary operators in conformal field theories using open Wilson network operators in the holographic gravitational dual. The Wilson operators are the gravitational ones where gravity is written as a gauge theory in the first order Hilbert-Palatini formalism. We apply this method to compute the global conformal blocks and partial waves in 2d CFTs reproducing many of the known results.

  11. Friedmann Propulsion in an Flat Holographic Universe

    NASA Astrophysics Data System (ADS)

    Binder, Bernd

    2008-01-01

    Because of inversion symmetries in holographic systems, the spatial compression of lower-dimensional holographic memory leads to an expansion of the holographic image and vice versa (scaling duality), where the geometric mean between the small quantum memory and cosmic image scale defines the inversion scale, the unit scale to normalize the global holographic currents of momentum exchange. Assigning to the cosmic image (bulk) a 4d, to the quantum memory (baryon) a 2d, and to the inversion scale a 3d spherical topology, the cosmic critical density in the flat FRW cosmic test model corresponds to 1 memory unit (baryon). Otherwise, if we expect expansion driven by 3d Einstein gravity on all scales, we get the well known cosmic ``dark matter'' deficit of 96% or 0.04 baryons per unit volume. The cosmic deficit or quantum excess is assigned by Gauss law to the topological ratio 4d bulk surface S3 to 2d quantum surface S1, which dilutes gravity or the mass density by the dimensionless factor 0.04~S3/2/S13 = 1/(8π) leading to a theoretical Hubble parameter of 73.2 kms-1 Mpc-1. Regarding propulsion based on fractional linear transforms mapping the quantum compression by inversion to a cosmic expansion, the anisotropic transform resembles the Alcubierre mechanism if expansion is behind and the compression ahead of the spaceship.

  12. Resolution limits in holographic display with LED illumination

    NASA Astrophysics Data System (ADS)

    Chlipała, Maksymilian; Kozacki, Tomasz

    2015-06-01

    In presented paper we study the influence of spatial and temporal coherence of light source on resolution and depth of focus of holographic reconstructions. Presented holographic display setup uses phase - only spatial light modulator and realizes complex coding shame which allows to reconstruct objects in volume centered around plane of the modulator. In simulations we implement partially coherent reconstructions of complex hologram theory. It allows to investigate quality of holographic reconstructions for various degree of illuminating light coherence. During experimental tests we validate simulation results. We show that the influence of spatial coherence effect of light source on resolution of reconstructed objects is stronger than that of temporal coherence. Moreover we prove that it is possible to obtain high quality holographic reconstructions for large size source and wide spectrum for objects having large depths.

  13. Holographic dark energy and late cosmic acceleration

    NASA Astrophysics Data System (ADS)

    Pavón, Diego

    2007-06-01

    It has been persuasively argued that the number of effective degrees of freedom of a macroscopic system is proportional to its area rather than to its volume. This entails interesting consequences for cosmology. Here we present a model based on this 'holographic principle' that accounts for the present stage of accelerated expansion of the Universe and significantly alleviates the coincidence problem also for non-spatially flat cosmologies. Likewise, we comment on a recently proposed late transition to a fresh decelerated phase.

  14. Nonnegative least-correlated component analysis for separation of dependent sources by volume maximization.

    PubMed

    Wang, Fa-Yu; Chi, Chong-Yung; Chan, Tsung-Han; Wang, Yue

    2010-05-01

    Although significant efforts have been made in developing nonnegative blind source separation techniques, accurate separation of positive yet dependent sources remains a challenging task. In this paper, a joint correlation function of multiple signals is proposed to reveal and confirm that the observations after nonnegative mixing would have higher joint correlation than the original unknown sources. Accordingly, a new nonnegative least-correlated component analysis (n/LCA) method is proposed to design the unmixing matrix by minimizing the joint correlation function among the estimated nonnegative sources. In addition to a closed-form solution for unmixing two mixtures of two sources, the general algorithm of n/LCA for the multisource case is developed based on an iterative volume maximization (IVM) principle and linear programming. The source identifiability and required conditions are discussed and proven. The proposed n/LCA algorithm, denoted by n/LCA-IVM, is evaluated with both simulation data and real biomedical data to demonstrate its superior performance over several existing benchmark methods. PMID:20299711

  15. Bacterial spore heat resistance correlated with water content, wet density, and protoplast/sporoplast volume ratio.

    PubMed Central

    Beaman, T C; Greenamyre, J T; Corner, T R; Pankratz, H S; Gerhardt, P

    1982-01-01

    Five types of dormant Bacillus spores, between and within species, were selected representing a 600-fold range in moist-heat resistance determined as a D100 value. The wet and dry density and the solids and water content of the entire spore and isolated integument of each type were determined directly from gram masses of material, with correction for interstitial water. The ratio between the volume occupied by the protoplast (the structures bounded by the inner pericytoplasm membrane) and the volume occupied by the sporoplast (the structures bounded by the outer pericortex membrane) was calculated from measurements made on electron micrographs of medially thin-sectioned spores. Among the various spore types, an exponential increase in the heat resistance correlated directly with the wet density and inversely with the water content and with the protoplast/sporoplast volume ratio. Altogether with results supported a hypothesis that the extent of heat resistance is based in whole or in part on the extent of dehydration and diminution of the protoplast in the dormant spore, without implications about physiological mechanisms for attaining this state. Images PMID:6802802

  16. Serotonergic, brain volume and attentional correlates of trait anxiety in primates.

    PubMed

    Mikheenko, Yevheniia; Shiba, Yoshiro; Sawiak, Stephen; Braesicke, Katrin; Cockcroft, Gemma; Clarke, Hannah; Roberts, Angela C

    2015-05-01

    Trait anxiety is a risk factor for the development and maintenance of affective disorders, and insights into the underlying brain mechanisms are vital for improving treatment and prevention strategies. Translational studies in non-human primates, where targeted neurochemical and genetic manipulations can be made, are critical in view of their close neuroanatomical similarity to humans in brain regions implicated in trait anxiety. Thus, we characterised the serotonergic and regional brain volume correlates of trait-like anxiety in the marmoset monkey. Low- and high-anxious animals were identified by behavioral responses to a human intruder (HI) that are known to be sensitive to anxiolytic drug treatment. Extracellular serotonin levels within the amygdala were measured with in vivo microdialysis, at baseline and in response to challenge with the selective serotonin reuptake inhibitor, citalopram. Regional brain volume was assessed by structural magnetic resonance imaging. Anxious individuals showed persistent, long-term fearful responses to both a HI and a model snake, alongside sustained attention (vigilance) to novel cues in a context associated with unpredictable threat. Neurally, high-anxious marmosets showed reduced amygdala serotonin levels, and smaller volumes in a closely connected prefrontal region, the dorsal anterior cingulate cortex. These findings highlight behavioral and neural similarities between trait-like anxiety in marmosets and humans, and set the stage for further investigation of the processes contributing to vulnerability and resilience to affective disorders. PMID:25586542

  17. GSTM1 Gene Expression Correlates to Leiomyoma Volume Regression in Response to Mifepristone Treatment

    PubMed Central

    Engman, Mikael; Varghese, Suby; Lagerstedt Robinson, Kristina; Malmgren, Helena; Hammarsjö, Anna; Byström, Birgitta; L Lalitkumar, Parameswaran Grace; Gemzell-Danielsson, Kristina

    2013-01-01

    Progesterone receptor modulators, such as mifepristone are useful and well tolerated in reducing leiomyoma volume although with large individual variation. The objective of this study was to investigate the molecular basis for the observed leiomyoma volume reduction, in response to mifepristone treatment and explore a possible molecular marker for the selective usage of mifepristone in leiomyoma patients. Premenopausal women (N = 14) were treated with mifepristone 50 mg, every other day for 12 weeks prior to surgery. Women were arbitrarily sub-grouped as good (N = 4), poor (N = 4) responders to treatment or intermediate respondents (N = 3). Total RNA was extracted from leiomyoma tissue, after surgical removal of the tumour and the differential expression of genes were analysed by microarray. The results were analysed using Ingenuity Pathway Analysis software. The glutathione pathway was the most significantly altered canonical pathway in which the glutathione-s transferase mu 1 (GSTM1) gene was significantly over expressed (+8.03 folds) among the good responders compared to non responders. This was further confirmed by Real time PCR (p = 0.024). Correlation of immunoreactive scores (IRS) for GSTM1 accumulation in leiomyoma tissue was seen with base line volume change of leiomyoma R = −0.8 (p = 0.011). Furthermore the accumulation of protein GSTM1 analysed by Western Blot correlated significantly with the percentual leiomyoma volume change R = −0.82 (p = 0.004). Deletion of the GSTM1 gene in leiomyoma biopsies was found in 50% of the mifepristone treated cases, with lower presence of the GSTM1 protein. The findings support a significant role for GSTM1 in leiomyoma volume reduction induced by mifepristone and explain the observed individual variation in this response. Furthermore the finding could be useful to further explore GSTM1 as a biomarker for tailoring medical treatment of uterine leiomyomas for optimizing the response

  18. Diffused holographic information storage and retrieval using photorefractive optical materials

    NASA Astrophysics Data System (ADS)

    McMillen, Deanna Kay

    Holography offers a tremendous opportunity for dense information storage, theoretically one bit per cubic wavelength of material volume, with rapid retrieval, of up to thousands of pages of information simultaneously. However, many factors prevent the theoretical storage limit from being reached, including dynamic range problems and imperfections in recording materials. This research explores new ways of moving closer to practical holographic information storage and retrieval by altering the recording materials, in this case, photorefractive crystals, and by increasing the current storage capacity while improving the information retrieved. As an experimental example of the techniques developed, the information retrieved is the correlation peak from an optical recognition architecture, but the materials and methods developed are applicable to many other holographic information storage systems. Optical correlators can potentially solve any signal or image recognition problem. Military surveillance, fingerprint identification for law enforcement or employee identification, and video games are but a few examples of applications. A major obstacle keeping optical correlators from being universally accepted is the lack of a high quality, thick (high capacity) holographic recording material that operates with red or infrared wavelengths which are available from inexpensive diode lasers. This research addresses the problems from two positions: find a better material for use with diode lasers, and reduce the requirements placed on the material while maintaining an efficient and effective system. This research found that the solutions are new dopants introduced into photorefractive lithium niobate to improve wavelength sensitivities and the use of a novel inexpensive diffuser that reduces the dynamic range and optical element quality requirements (which reduces the cost) while improving performance. A uniquely doped set of 12 lithium niobate crystals was specified and

  19. The techniques of holographic particle sizing

    NASA Technical Reports Server (NTRS)

    Kurtz, R. L.

    1973-01-01

    Depending on the mechanism of particle production, the resultant particle size and velocity distribution may range over several orders of magnitude. In general, if particle size information is desired from a given type generator, one must resort to some form of experimental determination of the distribution. If the source of particle production is a dynamic one involving a reasonable volume, holography provides a tailor-made particle size and velocity distribution detector. This is evidenced by the fact that holography allows the entire volume to be recorded on one exposure without any interference with the volume of interest. Herein lies a very important characteristic of the holographic particle detection technique: It provides a holographic nondestructive testing technique in the fullest sense of the definition of nondestructive testing. This report provides a description of three different systems useful in this technique and includes the experimental results from one of the holographic systems which was used to detect particle size and velocity distribution from the Skylab waste tank.

  20. Image preprocessing based on spatial statistics for the optical correlation recognition of aviation photographs

    NASA Astrophysics Data System (ADS)

    Sun, Yifan; Tan, Qiaofeng; Cao, Liangcai; Ni, Kai; He, Qingsheng; Jin, Guofan

    2008-03-01

    A new method of digital image processing is developed for the correlation recognition of aviation photographs under volume holographic correlator. The physical characteristics of semivariogram of the image are analyzed according to spatial statistics, which suggests the principle of the image segmentation, including the dimension of the templates, the space between each template and the image restoration. Then the residual space of each template is calculated directly based on the 2D-images to enlarge and to scatter the differences between the correlativity. After that, the residual spaces are reconstructed to form the final set of templates. Finally the proposed method is tested on a series of aviation photographs. The experimental results come with rather higher precision as well as rather lower computational complexity, which supports the real-time capability of the optical correlation recognition of aviation photographs under volume holographic correlator.

  1. Gray matter volume and executive functioning correlate with time since injury following mild traumatic brain injury.

    PubMed

    Killgore, William D S; Singh, Prabhjyot; Kipman, Maia; Pisner, Derek; Fridman, Andrew; Weber, Mareen

    2016-01-26

    Most people who sustain a mild traumatic brain injury (mTBI) will recover to baseline functioning within a period of several days to weeks. A substantial minority of patients, however, will show persistent symptoms and mild cognitive complaints for much longer. To more clearly delineate how the duration of time since injury (TSI) is associated with neuroplastic cortical volume changes and cognitive recovery, we employed voxel-based morphometry (VBM) and select neuropsychological measures in a cross-sectional sample of 26 patients with mTBI assessed at either two-weeks, one-month, three-months, six-months, or one-year post injury, and a sample of 12 healthy controls. Longer duration of TSI was associated with larger gray matter volume (GMV) within the ventromedial prefrontal cortex (vmPFC) and right fusiform gyrus, and better neurocognitive performance on measures of visuospatial design fluency and emotional functioning. In particular, volume within the vmPFC was positively correlated with design fluency and negatively correlated with symptoms of anxiety, whereas GMV of the fusiform gyrus was associated with greater design fluency and sustained visual psychomotor vigilance performance. Moreover, the larger GMV seen among the more chronic individuals was significantly greater than healthy controls, suggesting possible enlargement of these regions with time since injury. These findings are interpreted in light of burgeoning evidence suggesting that cortical regions often exhibit structural changes following experience or practice, and suggest that with greater time since an mTBI, the brain displays compensatory remodeling of cortical regions involved in emotional regulation, which may reduce distractibility during attention demanding visuo-motor tasks. PMID:26711488

  2. Magnonic Holographic Memory

    NASA Astrophysics Data System (ADS)

    Khitun, Alexander; Kozhevnikov, Alexander; Gertz, Frederick; Filimonov, Yuri

    2015-03-01

    Collective oscillation of spins in magnetic lattice known as spin waves (magnons) possess relatively long coherence length at room temperature, which makes it possible to build sub-micrometer scale holographic devices similar to the devices developed in optics. In this work, we present a prototype 2-bit magnonic holographic memory. The memory consists of the double-cross waveguide structure made of Y3Fe2(FeO4)3 with magnets placed on the top of waveguide junctions. Information is encoded in the orientation of the magnets, while the read-out is accomplished by the spin waves generated by the micro-antennas placed on the edges of the waveguides. The interference pattern produced by multiple spin waves makes it possible to build a unique holographic image of the magnetic structure and recognize the state of the each magnet. The development of magnonic holographic devices opens a new horizon for building scalable holographic devices compatible with conventional electronic devices. This work was supported in part by the FAME Center, one of six centers of STARnet, a Semiconductor Research Corporation program sponsored by MARCO and DARPA and by the National Science Foundation under the NEB2020 Grant ECCS-1124714.

  3. Full-color holographic 3D printer

    NASA Astrophysics Data System (ADS)

    Takano, Masami; Shigeta, Hiroaki; Nishihara, Takashi; Yamaguchi, Masahiro; Takahashi, Susumu; Ohyama, Nagaaki; Kobayashi, Akihiko; Iwata, Fujio

    2003-05-01

    A holographic 3D printer is a system that produces a direct hologram with full-parallax information using the 3-dimensional data of a subject from a computer. In this paper, we present a proposal for the reproduction of full-color images with the holographic 3D printer. In order to realize the 3-dimensional color image, we selected the 3 laser wavelength colors of red (λ=633nm), green (λ=533nm), and blue (λ=442nm), and we built a one-step optical system using a projection system and a liquid crystal display. The 3-dimensional color image is obtained by synthesizing in a 2D array the multiple exposure with these 3 wavelengths made on each 250mm elementary hologram, and moving recording medium on a x-y stage. For the natural color reproduction in the holographic 3D printer, we take the approach of the digital processing technique based on the color management technology. The matching between the input and output colors is performed by investigating first, the relation between the gray level transmittance of the LCD and the diffraction efficiency of the hologram and second, by measuring the color displayed by the hologram to establish a correlation. In our first experimental results a non-linear functional relation for single and multiple exposure of the three components were found. These results are the first step in the realization of a natural color 3D image produced by the holographic color 3D printer.

  4. Holographic mixing quantified

    SciTech Connect

    Batell, Brian; Gherghetta, Tony

    2007-08-15

    We compute the precise elementary/composite field content of mass eigenstates in holographic duals of warped models in a slice of AdS{sub 5}. This is accomplished by decomposing the bulk fields not in the usual Kaluza-Klein basis, but rather into a holographic basis of 4D fields, corresponding to purely elementary source or conformal field theory (CFT) composite fields. Generically, this decomposition yields kinetic and mass mixing between the elementary and composite sectors of the holographic theory. Depending on where the bulk zero mode is localized, the elementary/composite content may differ radically, which we show explicitly for several examples including the bulk Randall-Sundrum graviton, bulk gauge boson, and Higgs boson.

  5. The Correlation Between Age and Bleeding Volume in Haemorrhagic Stroke Using Multi Slice CT at District Hospitals in Jakarta.

    PubMed

    Saefudin, Tatan; Apriantoro, Nursama Heru; Hidayat, Ekaputra Syarif; Purnamawati, Schandra

    2016-04-01

    Haemorrhagic Stroke is a common disease in Indonesia. The best imaging modality for this disease is Multi Slice Computed Tomography Scanning (MSCT), as it may help strengthening the diagnosis as well as determining the brain bleeding volume. This study aimed to show correlation between bleeding volume of the brain and patient's age using cross-sectional approach. The 68 samples in this study were taken from secondary data from Head CT Scan of Haemorrhagic Stroke cases.  Brain bleeding volume is the dependent variable, obtained through slice thickness of 5 mm and ABC/2 method with software measurement in MSCT Scan device. The independent variable of this study is the patient's age. The result of the study was the average brain's bleeding volume of 21.76 ml ± 2.48 ml (range of 1.04 ml to 94.73 ml).The slice thickness using ABC/2 method, has a significant correlation with brain's bleeding volume in MSCT Scan examination, with correlation coefficient value r of 0.79. Brain bleeding volume in patients who have ages lower than 50 years and more or equal to 50 years were (18.93 ± 3.26) ml and (23.53 ± 3.47) ml respectively. There is no correlation between age and brain's bleeding volume in haemorrhagic stroke cases, with p value of 0.18, r = 0.19. PMID:26573030

  6. The Correlation Between Age and Bleeding Volume in Haemorrhagic Stroke Using Multi Slice CT at District Hospitals in Jakarta

    PubMed Central

    Saefudin, Tatan; Apriantoro, Nursama Heru; Hidayat, Ekaputra Syarif; Purnamawati, Schandra

    2016-01-01

    Haemorrhagic Stroke is a common disease in Indonesia. The best imaging modality for this disease is Multi Slice Computed Tomography Scanning (MSCT), as it may help strengthening the diagnosis as well as determining the brain bleeding volume. This study aimed to show correlation between bleeding volume of the brain and patient’s age using cross-sectional approach. The 68 samples in this study were taken from secondary data from Head CT Scan of Haemorrhagic Stroke cases. Brain bleeding volume is the dependent variable, obtained through slice thickness of 5 mm and ABC/2 method with software measurement in MSCT Scan device. The independent variable of this study is the patient’s age. The result of the study was the average brain’s bleeding volume of 21.76 ml ± 2.48 ml (range of 1.04 ml to 94.73 ml). The slice thickness using ABC/2 method, has a significant correlation with brain’s bleeding volume in MSCT Scan examination, with correlation coefficient value r of 0.79. Brain bleeding volume in patients who have ages lower than 50 years and more or equal to 50 years were (18.93 ± 3.26) ml and (23.53 ± 3.47) ml respectively. There is no correlation between age and brain’s bleeding volume in haemorrhagic stroke cases, with p value of 0.18, r = 0.19. PMID:26573030

  7. Dynamical instability of holographic QCD at finite density

    NASA Astrophysics Data System (ADS)

    Chuang, Wu-Yen; Dai, Shou-Huang; Kawamoto, Shoichi; Lin, Feng-Li; Yeh, Chen-Pin

    2011-05-01

    In this paper we study the dynamical instability of Sakai-Sugimoto’s holographic QCD model at finite baryon density. In this model, the baryon density, represented by the smeared instanton on the world volume of the probe D8-D8¯ mesonic brane, sources the world-volume electric field, and through the Chern-Simons term it will induce the instability to form a chiral helical wave at sufficient high density. Our results show that this kind of instability occurs for sufficiently high baryon number densities. The phase diagram of holographic QCD will thus be changed from the one which is based only on thermodynamics.

  8. Dynamical instability of holographic QCD at finite density

    SciTech Connect

    Chuang, Wu-Yen; Dai, Shou-Huang; Kawamoto, Shoichi; Lin, Feng-Li; Yeh, Chen-Pin

    2011-05-15

    In this paper we study the dynamical instability of Sakai-Sugimoto's holographic QCD model at finite baryon density. In this model, the baryon density, represented by the smeared instanton on the world volume of the probe D8-D8 mesonic brane, sources the world-volume electric field, and through the Chern-Simons term it will induce the instability to form a chiral helical wave at sufficient high density. Our results show that this kind of instability occurs for sufficiently high baryon number densities. The phase diagram of holographic QCD will thus be changed from the one which is based only on thermodynamics.

  9. Holographic RG flows, entanglement entropy and the sum rule

    NASA Astrophysics Data System (ADS)

    Casini, Horacio; Testé, Eduardo; Torroba, Gonzalo

    2016-03-01

    We calculate the two-point function of the trace of the stress tensor in holographic renormalization group flows between pairs of conformal field theories. We show that the term proportional to the momentum squared in this correlator gives the change of the central charge between fixed points in d = 2 and in d > 2 it gives the holographic entanglement entropy for a planar region. This can also be seen as a holographic realization of the Adler-Zee formula for the renormalization of Newton's constant. Holographic regularization is found to provide a perfect match of the finite and divergent terms of the sum rule, and it is analogous to the regularization of the entropy in terms of mutual information. Finally, we provide a general proof of reflection positivity in terms of stability of the dual bulk action, and discuss the relation between unitarity constraints, the null energy condition and regularity in the interior of the gravity solution.

  10. Precision Holographic Baryons

    SciTech Connect

    Yi Piljin

    2011-10-21

    We overview a holographic QCD based on the D4-D8 string theory model, with emphasis on baryons and nucleon-meson interactions thereof. Baryons are realized as holographic images of Skyrmions, but with much qualitative changes. This allows us to derive, without adjustable parameters, couplings of baryons to the entire tower of spin one mesons and also to pseudoscalar mesons. We find some surprisingly good match against empirical values for nucleons, in particular. Tensor couplings to all axial-vectors and iso-singlet vectors all vanish, while, for {rho} mesons, tensor couplings are found to be dominant. We close with various cautionary comments and speculations.

  11. Precision Holographic Baryons

    NASA Astrophysics Data System (ADS)

    Yi, Piljin

    2011-10-01

    We overview a holographic QCD based on the D4-D8 string theory model, with emphasis on baryons and nucleon-meson interactions thereof. Baryons are realized as holographic images of Skyrmions, but with much qualitative changes. This allows us to derive, without adjustable parameters, couplings of baryons to the entire tower of spin one mesons and also to pseudoscalar mesons. We find some surprisingly good match against empirical values for nucleons, in particular. Tensor couplings to all axial-vectors and iso-singlet vectors all vanish, while, for ρ mesons, tensor couplings are found to be dominant. We close with various cautionary comments and speculations.

  12. Computer generated holographic microtags

    DOEpatents

    Sweatt, William C.

    1998-01-01

    A microlithographic tag comprising an array of individual computer generated holographic patches having feature sizes between 250 and 75 nanometers. The tag is a composite hologram made up of the individual holographic patches and contains identifying information when read out with a laser of the proper wavelength and at the proper angles of probing and reading. The patches are fabricated in a steep angle Littrow readout geometry to maximize returns in the -1 diffracted order. The tags are useful as anti-counterfeiting markers because of the extreme difficulty in reproducing them.

  13. Computer generated holographic microtags

    DOEpatents

    Sweatt, W.C.

    1998-03-17

    A microlithographic tag comprising an array of individual computer generated holographic patches having feature sizes between 250 and 75 nanometers is disclosed. The tag is a composite hologram made up of the individual holographic patches and contains identifying information when read out with a laser of the proper wavelength and at the proper angles of probing and reading. The patches are fabricated in a steep angle Littrow readout geometry to maximize returns in the -1 diffracted order. The tags are useful as anti-counterfeiting markers because of the extreme difficulty in reproducing them. 5 figs.

  14. Correlation between gall bladder fasting volume and postprandial emptying in patients with gall stones and healthy controls.

    PubMed Central

    Pauletzki, J; Cicala, M; Holl, J; Sauerbruch, T; Schafmayer, A; Paumgartner, G

    1993-01-01

    To evaluate whether the extent of postprandial gall bladder emptying is correlated with gall bladder fasting volume, gall bladder motility was studied in 56 patients with cholesterol gall stone and 19 control patients. Gall bladder volumes were determined sonographically, while cholecystokinin plasma values were measured radioimmunologically. Twenty three per cent of gall stone patients were classified as pathological contractors (residual fraction > mean +2SD of controls) and 77% as normal contractors. Normal but not pathological contractor patients exhibited larger gall bladder fasting volumes (mean (SEM)) (24.7 (1.7) ml) than controls (15.3 (1.2) ml, p < 0.001). In normal contractor patients and controls fasting volume was closely related with ejection volume (r = 0.97, p < 0.001) and residual volume (r = 0.80, p < 0.001). Although ejection volume was enlarged in normal contractor patients it did not compensate the increase in fasting volume. Thus, residual volumes were considerably increased not only in pathological contractors (12.7 (2.5) ml, p < 0.001) but also in normal contractor patients (7.0 (0.5) v 4.6 (0.6) ml, p < 0.001). Postprandial cholecystokinin secretion did not differ between patients and controls. It is concluded, that in normal contractor patients gall bladder fasting volume is closely correlated with ejection and residual volume. Thus, fasting volume may be an essential factor affecting postprandial gall bladder emptying. Large fasting volumes in cholesterol gall stone disease could thereby contribute to bile retention, which facilitates gall stone growth. PMID:8244118

  15. Conformal quantum mechanics and holographic quench

    NASA Astrophysics Data System (ADS)

    Järvelä, Jarkko; Keränen, Ville; Keski-Vakkuri, Esko

    2016-02-01

    Recently, there has been much interest in holographic computations of two-point nonequilibrium Green functions from anti-de Sitter- (AdS-)Vaidya backgrounds. In the strongly coupled quantum field theory on the boundary, the dual interpretation of the background is an equilibration process called a holographic quench. The two-dimensional AdS-Vaidya spacetime is a special case, dual to conformal quantum mechanics. We study how the quench is incorporated into a Hamiltonian H +θ (t )Δ H and into correlation functions. With the help of recent work on correlation functions in conformal quantum mechanics, we first rederive the known two-point functions, and then compute nonequilibrium three- and four-point functions. We also compute the three-point function Witten diagram in the two-dimensional AdS-Vaidya background, and find agreement with the conformal quantum mechanics result.

  16. Dynamic volume vs respiratory correlated 4DCT for motion assessment in radiation therapy simulation

    SciTech Connect

    Coolens, Catherine; Bracken, John; Driscoll, Brandon; Hope, Andrew; Jaffray, David

    2012-05-15

    Purpose: Conventional (i.e., respiratory-correlated) 4DCT exploits the repetitive nature of breathing to provide an estimate of motion; however, it has limitations due to binning artifacts and irregular breathing in actual patient breathing patterns. The aim of this work was to evaluate the accuracy and image quality of a dynamic volume, CT approach (4D{sub vol}) using a 320-slice CT scanner to minimize these limitations, wherein entire image volumes are acquired dynamically without couch movement. This will be compared to the conventional respiratory-correlated 4DCT approach (RCCT). Methods: 4D{sub vol} CT was performed and characterized on an in-house, programmable respiratory motion phantom containing multiple geometric and morphological ''tumor'' objects over a range of regular and irregular patient breathing traces obtained from 3D fluoroscopy and compared to RCCT. The accuracy of volumetric capture and breathing displacement were evaluated and compared with the ground truth values and with the results reported using RCCT. A motion model was investigated to validate the number of motion samples needed to obtain accurate motion probability density functions (PDF). The impact of 4D image quality on this accuracy was then investigated. Dose measurements using volumetric and conventional scan techniques were also performed and compared. Results: Both conventional and dynamic volume 4DCT methods were capable of estimating the programmed displacement of sinusoidal motion, but patient breathing is known to not be regular, and obvious differences were seen for realistic, irregular motion. The mean RCCT amplitude error averaged at 4 mm (max. 7.8 mm) whereas the 4D{sub vol} CT error stayed below 0.5 mm. Similarly, the average absolute volume error was lower with 4D{sub vol} CT. Under irregular breathing, the 4D{sub vol} CT method provides a close description of the motion PDF (cross-correlation 0.99) and is able to track each object, whereas the RCCT method results in a

  17. Changes in thymus volume in adult HIV-infected patients under HAART: correlation with the T-cell repopulation

    PubMed Central

    RUBIO, A; MARTÍNEZ-MOYA, M; LEAL, M; FRANCO, J M; RUIZ-MATEOS, E; MERCHANTE, E; SÁNCHEZ-QUIJANO, A; LISSEN, E

    2002-01-01

    An important thymus role has been suggested in T-cell repopulation after HAART in adult HIV-1 infected patients. Thymus volume increase after treatment has been described in HIV-1 infected children but not in adult patients. The objective of this work was to evaluate the effect of HAART on the thymic volume of adult HIV-1 infected patients and its relation with the T-cell repopulation. Twenty-one adult patients following 24 weeks under HAART were included in the study. All patients underwent a thoracic computed tomography (CT) evaluation for the measurement of thymic volumes at weeks 0, 12 and 24. Baseline thymus volume showed a significant correlation with the patient's age. Thymic volume significantly increased after 24 weeks of HAART. Besides, a significant correlation between changes in the thymus volume and changes in both total and naïve CD4+ cell counts was found. Only patients with increases ≥100 CD4+ cell counts after treatment significantly increased the thymic volume. These data show the first evidence of an early change in thymic volume of adult HIV-1 infected patients under HAART. This increase was related to the rise of both total and naïve CD4+ cell counts suggesting a functional role of thymic volume increase. PMID:12296862

  18. Testicular volume is inversely correlated with nurturing-related brain activity in human fathers.

    PubMed

    Mascaro, Jennifer S; Hackett, Patrick D; Rilling, James K

    2013-09-24

    Despite the well-documented benefits afforded the children of invested fathers in modern Western societies, some fathers choose not to invest in their children. Why do some men make this choice? Life History Theory offers an explanation for variation in parental investment by positing a trade-off between mating and parenting effort, which may explain some of the observed variance in human fathers' parenting behavior. We tested this hypothesis by measuring aspects of reproductive biology related to mating effort, as well as paternal nurturing behavior and the brain activity related to it. Both plasma testosterone levels and testes volume were independently inversely correlated with paternal caregiving. In response to viewing pictures of one's own child, activity in the ventral tegmental area--a key component of the mesolimbic dopamine reward and motivation system--predicted paternal caregiving and was negatively related to testes volume. Our results suggest that the biology of human males reflects a trade-off between mating effort and parenting effort, as indexed by testicular size and nurturing-related brain function, respectively. PMID:24019499

  19. The correlation between gray matter volume and perceived social support: a voxel-based morphometry study.

    PubMed

    Che, XianWei; Wei, DongTao; Li, WenFu; Li, HaiJiang; Qiao, Lei; Qiu, Jiang; Zhang, QingLin; Liu, YiJun

    2014-01-01

    Social support refers to interpersonal exchanges that include the combinations of aid, affirmation and affection. Perceived social support is a kind of subjective judgment of one's availability of social support. In spite of the importance of perceived social support to health, however, its neural substrate remains unknown. To address this question, voxel-based morphometry was employed to investigate the neural bases of individual differences in responses to the Perceived Social Support Scale (PSSS) in healthy volunteers (144 men and 203 women; mean age = 19.9; SD = 1.33, age range : 17-27). As a result, multiple regression analysis revealed that the PSSS scores were significantly and positively correlated with gray matter volume in a cluster that mainly included areas in posterior parts of posterior cingulate cortex, bilateral lingual cortex, left occipital lobe and cuneus. Highly-supported individuals had larger gray matter volume in these brain regions, implying a relatively high level of ability to engage in self-referential processes and social cognition. Our results provide a biological basis for exploring perceived social support particularly in relationship to various health parameters and outcomes. PMID:24397344

  20. Magnetic oscillations in a holographic liquid

    NASA Astrophysics Data System (ADS)

    Giangreco M. Puletti, V.; Nowling, S.; Thorlacius, L.; Zingg, T.

    2015-04-01

    We present a holographic perspective on magnetic oscillations in strongly correlated electron systems via a fluid of charged spin 1 /2 particles outside a black brane in an asymptotically anti-de-Sitter spacetime. The resulting backreaction on the spacetime geometry and bulk gauge field gives rise to magnetic oscillations in the dual field theory, which can be directly studied without introducing probe fermions, and which differ from those predicted by Fermi liquid theory.

  1. 3D measurements of live cells via digital holographic microscopy and terahertz spectroscopy

    NASA Astrophysics Data System (ADS)

    Park, Jun Yong; Oser, Dorian; Iapozzuto, Peter; Norbury, Sean; Mahajan, Supriya; Khmaladze, Alexander; Sharikova, Anna

    2016-03-01

    This is a study of the central nervous system (CNS) cells, including brain micro vascular endothelial cells (BMV) that constitute the blood brain barrier, and C6 glial cells that are the predominant cell in the brain. The cells are exposed to various chemicals by non-invasive, label-free methods. Digital holographic microscopy (DHM) is a technique that records an interference pattern between an object and reference waves, so that the computationally reconstructed holographic image contains both amplitude and phase information, and 3D images are obtained. The measurement of cell cultures by digital holographic microscopy yields information about cell death mechanisms, since these processes are correlated with individual cell volume. Our in-house DHM combines a visible (red) laser source with a conventional microscope base, and LabVIEW-run data processing. Terahertz spectral signatures are associated with structural changes in molecules and provide complementary information about cells. Both CNS cells BMV and C6 cells are treated with the drug "Methamphetamine" (METH), which induces apoptosis in neuronal cells and exhibits decrease in cell volume, a characteristic of cells undergoing apoptosis (induced cell death). METH can cause CNS cell death by cross-talk between mitochondria-, endoplasmic reticulum-, and receptor-mediated apoptotic events, all of which results in drug induced changes in neuroplasticity and significant neuropathology. Doxorubicin (DOX), a popular anticancer drug, is used as a control. We observe that METH treatment resulted in more pronounced cell volume shrinkage in both the BMV and C6 cells, as compared to DOX-induced cell apoptosis.

  2. Holographic vector-wave femtosecond laser processing

    NASA Astrophysics Data System (ADS)

    Hayasaki, Yoshio; Hasegawa, Satoshi

    2016-03-01

    Arbitrary and variable beam shaping of femtosecond pulses by a computer-generated hologram (CGH) displayed on a spatial light modulator (SLM) have been applied to femtosecond laser processing. The holographic femtosecond laser processing has been widely used in many applications such as two-photon polymerization, optical waveguide fabrication, fabrication of volume phase gratings in polymers, and surface nanostructuring. A vector wave that has a spatial distribution of polarization states control of femtosecond pulses gives good performances for the femtosecond laser processing. In this paper, an in- system optimization of a CGH for massively-parallel femtosecond laser processing, a dynamic control of spatial spectral dispersion to improve the focal spot shape, and the holographic vector-wave femtosecond laser processing are demonstrated.

  3. White matter volume change and its correlation with symptom severity in patients with schizophrenia: a VBM-DARTEL study.

    PubMed

    Kim, Gwang-Won; Jeong, Gwang-Woo

    2015-12-16

    The aim of this study was to evaluate the white matter (WM) volume change and its correlation with symptom severity in patients with schizophrenia using voxel-based morphometry. A total of 20 patients with schizophrenia and 20 age-matched healthy controls participated in this study. MR image data were processed using SPM8 software with diffeomorphic anatomical registration through an exponentiated Lie algebra (DARTEL) algorithm. The patients with schizophrenia showed significant decreases (P=0.042) in the WM volumes of the temporal lobe and superior frontal gyrus compared with the healthy controls. The WM volumes of the middle temporal gyrus were negatively correlated with the scores of both the Positive Subscale (Pearson's ρ=-0.68, P=0.001) and the Negative Subscale (ρ=-0.71, P=0.0005) in the Positive and Negative Syndrome Scale. In addition, the scores of the General Psychopathology Subscale were negatively correlated with the WM volumes of the superior frontal gyrus (ρ=-0.68, P=0.0009). This study evaluated the WM volume of patients with schizophrenia compared with healthy controls using DARTEI-based voxel-based morphometry and also assessed the correlation of the localized WM volume changes with the Positive and Negative Syndrome Scale. These findings will be useful to understand the neuropathology associated with WM abnormality in schizophrenia. PMID:26485094

  4. Deriving Particle Distributions from In-Line Fraunhofer Holographic Data

    SciTech Connect

    C.A. Ciarcia; D.E. Johnson; D.S. Sorenson; R.H. Frederickson, A.D. Delanoy; R.M. Malone; T.W. Tunnel

    1997-08-01

    Holographic data are acquired during hydrodynamic experiments at the Pegasus Pulsed Power Facility at the Los Alamos National Laboratory. These experiments produce a fine spray of fast-moving particles. Snapshots of the spray are captured using in-line Fraunhofer holographic techniques. Roughly one cubic centimeter is recorded by the hologram. Minimum detectable particle size in the data extends down to 2 microns. In a holography reconstruction system, a laser illuminates the hologram as it rests in a three-axis actuator, recreating the snapshot of the experiment. A computer guides the actuators through an orderly sequence programmed by the user. At selected intervals, slices of this volume are captured and digitized with a CCD camera. Intermittent on-line processing of the image data and computer control of the camera functions optimizes statistics of the acquired image data for off-line processing. Tens of thousands of individual data frames (30 to 40 gigabytes of data) are required to recreate a digital representation of the snapshot. Throughput of the reduction system is 550 megabytes per hour (MB/hr). Objects and associated features from the data are subsequently extracted during off-line processing. Discrimination and correlation tests reject noise, eliminate multiple counting of particles, and build an error model to estimate performance. Objects surviving these tests are classified as particles. The particle distributions are derived from the data base formed by these particles, their locations and features. Throughput of the off-line processing exceeds 500 MB/hr. This paper describes the reduction system, outlines the off-line processing procedure, summarizes the discrimination and correlation tests, and reports numerical results for a sample data set.

  5. The Holographic Entropy Cone

    SciTech Connect

    Bao, Ning; Nezami, Sepehr; Ooguri, Hirosi; Stoica, Bogdan; Sully, James; Walter, Michael

    2015-09-21

    We initiate a systematic enumeration and classification of entropy inequalities satisfied by the Ryu-Takayanagi formula for conformal field theory states with smooth holographic dual geometries. For 2, 3, and 4 regions, we prove that the strong subadditivity and the monogamy of mutual information give the complete set of inequalities. This is in contrast to the situation for generic quantum systems, where a complete set of entropy inequalities is not known for 4 or more regions. We also find an infinite new family of inequalities applicable to 5 or more regions. The set of all holographic entropy inequalities bounds the phase space of Ryu-Takayanagi entropies, defining the holographic entropy cone. We characterize this entropy cone by reducing geometries to minimal graph models that encode the possible cutting and gluing relations of minimal surfaces. We find that, for a fixed number of regions, there are only finitely many independent entropy inequalities. To establish new holographic entropy inequalities, we introduce a combinatorial proof technique that may also be of independent interest in Riemannian geometry and graph theory.

  6. The Holographic Entropy Cone

    DOE PAGESBeta

    Bao, Ning; Nezami, Sepehr; Ooguri, Hirosi; Stoica, Bogdan; Sully, James; Walter, Michael

    2015-09-21

    We initiate a systematic enumeration and classification of entropy inequalities satisfied by the Ryu-Takayanagi formula for conformal field theory states with smooth holographic dual geometries. For 2, 3, and 4 regions, we prove that the strong subadditivity and the monogamy of mutual information give the complete set of inequalities. This is in contrast to the situation for generic quantum systems, where a complete set of entropy inequalities is not known for 4 or more regions. We also find an infinite new family of inequalities applicable to 5 or more regions. The set of all holographic entropy inequalities bounds the phasemore » space of Ryu-Takayanagi entropies, defining the holographic entropy cone. We characterize this entropy cone by reducing geometries to minimal graph models that encode the possible cutting and gluing relations of minimal surfaces. We find that, for a fixed number of regions, there are only finitely many independent entropy inequalities. To establish new holographic entropy inequalities, we introduce a combinatorial proof technique that may also be of independent interest in Riemannian geometry and graph theory.« less

  7. Chidi holographic video system

    NASA Astrophysics Data System (ADS)

    Nwodoh, Thomas A.; Benton, Stephen A.

    2000-03-01

    Holo-Chidi is a holographic video processing system designed at the MIT Media Laboratory for real-time computation of Computer Generated Holograms and the subsequent display of the holograms at video frame rates. It's processing engine is adapted from Chidi which is reconfigurable multimedia processing system used for real-time synthesis and analysis of digital video frames. Holo-Chidi is made of two main components: the sets of Chidi processor cards and the display video concentrator card. The processor cards are used for hologram computation while the display video concentrator card acts as frame buffer for the system. The display video concentrator also formats the computed holographic data and converts them to analog form for feeding the acousto-optic modulators of the Media Lab's Mark-II holographic display system. The display video concentrator card can display the computed holograms from the Chidi cards loaded from its high-speed I/O interface port or precomputed holograms loaded from a PC through the United Serial Bus port of its communications processor at above video refresh rates. This paper discusses the design of the display video concentrator used to display holographic video in the Mark-II system.

  8. The Holographic Quantum

    NASA Astrophysics Data System (ADS)

    Fernández de Córdoba, P.; Isidro, J. M.; Vazquez Molina, J.

    2016-07-01

    We present a map of standard quantum mechanics onto a dual theory, that of the classical thermodynamics of irreversible processes. While no gravity is present in our construction, our map exhibits features that are reminiscent of the holographic principle of quantum gravity.

  9. Holographic recording medium

    NASA Technical Reports Server (NTRS)

    Gange, Robert Allen (Inventor)

    1977-01-01

    A holographic recording medium comprising a conductive substrate, a photoconductive layer and an electrically alterable layer of a linear, low molecular weight hydrocarbon polymer has improved fatigue resistance. An acrylic barrier layer can be interposed between the photoconductive and electrically alterable layers.

  10. The holographic entropy cone

    NASA Astrophysics Data System (ADS)

    Bao, Ning; Nezami, Sepehr; Ooguri, Hirosi; Stoica, Bogdan; Sully, James; Walter, Michael

    2015-09-01

    We initiate a systematic enumeration and classification of entropy inequalities satisfied by the Ryu-Takayanagi formula for conformal field theory states with smooth holographic dual geometries. For 2, 3, and 4 regions, we prove that the strong subadditivity and the monogamy of mutual information give the complete set of inequalities. This is in contrast to the situation for generic quantum systems, where a complete set of entropy inequalities is not known for 4 or more regions. We also find an infinite new family of inequalities applicable to 5 or more regions. The set of all holographic entropy inequalities bounds the phase space of Ryu-Takayanagi entropies, defining the holographic entropy cone. We characterize this entropy cone by reducing geometries to minimal graph models that encode the possible cutting and gluing relations of minimal surfaces. We find that, for a fixed number of regions, there are only finitely many independent entropy inequalities. To establish new holographic entropy inequalities, we introduce a combinatorial proof technique that may also be of independent interest in Riemannian geometry and graph theory.

  11. [Correlation between the regional blood volume and epileptic seizures in Papio papio].

    PubMed

    Ancri, D; Naquet, R; Basset, J Y; Ménini, C; Lonchampt, M F; Meldrum, B S; Stutzmann, J M

    1979-07-16

    The method of labelling red cells with technetium-99m was used to measured regional blood volume auring different types of epileptic seizures induced in the Baboon Papio papio. During seizures the cerebral blood volume increases and there is simultaneously a decrease of blood volume in nasal and hepatic regions, and a transitory increase of blood volume in the forepaws. PMID:117933

  12. Striatal Volume Increases in Active Methamphetamine-Dependent Individuals and Correlation with Cognitive Performance

    PubMed Central

    Jan, Reem K.; Lin, Joanne C.; Miles, Sylvester W.; Kydd, Rob R.; Russell, Bruce R.

    2012-01-01

    The effect of methamphetamine (MA) dependence on the structure of the human brain has not been extensively studied, especially in active users. Previous studies reported cortical deficits and striatal gains in grey matter (GM) volume of abstinent MA abusers compared with control participants. This study aimed to investigate structural GM changes in the brains of 17 active MA-dependent participants compared with 20 control participants aged 18–46 years using voxel-based morphometry and region of interest volumetric analysis of structural magnetic resonance imaging data, and whether these changes might be associated with cognitive performance. Significant volume increases were observed in the right and left putamen and left nucleus accumbens of MA-dependent compared to control participants. The volumetric gain in the right putamen remained significant after Bonferroni correction, and was inversely correlated with the number of errors (standardised z-scores) on the Go/No-go task. MA-dependent participants exhibited cortical GM deficits in the left superior frontal and precentral gyri in comparison to control participants, although these findings did not survive correction for multiple comparisons. In conclusion, consistent with findings from previous studies of abstinent users, active chronic MA-dependent participants showed significant striatal enlargement which was associated with improved performance on the Go/No-go, a cognitive task of response inhibition and impulsivity. Striatal enlargement may reflect the involvement of neurotrophic effects, inflammation or microgliosis. However, since it was associated with improved cognitive function, it is likely to reflect a compensatory response to MA-induced neurotoxicity in the striatum, in order to maintain cognitive function. Follow-up studies are recommended to ascertain whether this effect continues to be present following abstinence. Several factors may have contributed to the lack of more substantial cortical and

  13. Differences in and correlations between cognitive abilities and brain volumes in healthy control, mild cognitive impairment, and Alzheimer disease groups.

    PubMed

    Chung, Soon-Cheol; Choi, Mi-Hyun; Kim, Hyung-Sik; Lee, Jung-Chul; Park, Sung-Jun; Jeong, Ul-Ho; Baek, Ji-Hye; Gim, Seon-Young; Choi, Young Chil; Lee, Beob-Yi; Lim, Dae-Woon; Kim, Boseong

    2016-05-01

    The purpose of this study is to investigate differences in and correlations between cognitive abilities and brain volumes in healthy control (HC), mild cognitive impairment (MCI), and Alzheimer's disease (AD) groups. The Korean Version of the Consortium to Establish a Registry for Alzheimer's Disease (CERAD-K), which is used to diagnose AD, was used to measure the cognitive abilities of the study subjects, and the volumes of typical brain components related to AD diagnosis-cerebrospinal fluid (CSF), gray matter (GM), and white matter (WM)-were acquired. Of the CERAD-K subtests, the Boston Naming Test distinguished significantly among the HC, MCI, and AD groups. GM and WM volumes differed significantly among the three groups. There was a significant positive correlation between Boston Naming Test scores and GM and WM volumes. In conclusion, the Boston Naming Test and GM and WM brain volumes differentiated the three tested groups accurately, and there were strong correlations between Boston Naming Test scores and GM and WM volumes. These results will help to establish a test method that differentiates the three groups accurately and is economically feasible. Clin. Anat. 29:473-480, 2016. © 2016 Wiley Periodicals, Inc. PMID:26710236

  14. Power-law correlations in finance-related Google searches, and their cross-correlations with volatility and traded volume: Evidence from the Dow Jones Industrial components

    NASA Astrophysics Data System (ADS)

    Kristoufek, Ladislav

    2015-06-01

    We study power-law correlations properties of the Google search queries for Dow Jones Industrial Average (DJIA) component stocks. Examining the daily data of the searched terms with a combination of the rescaled range and rescaled variance tests together with the detrended fluctuation analysis, we show that the searches are in fact power-law correlated with Hurst exponents between 0.8 and 1.1. The general interest in the DJIA stocks is thus strongly persistent. We further reinvestigate the cross-correlation structure between the searches, traded volume and volatility of the component stocks using the detrended cross-correlation and detrending moving-average cross-correlation coefficients. Contrary to the universal power-law correlations structure of the related Google searches, the results suggest that there is no universal relationship between the online search queries and the analyzed financial measures. Even though we confirm positive correlation for a majority of pairs, there are several pairs with insignificant or even negative correlations. In addition, the correlations vary quite strongly across scales.

  15. SPDC correlated photon source filtered for narrowed bandwidth using volume Bragg grating

    NASA Astrophysics Data System (ADS)

    Slattery, Oliver; Kuo, Paulina; Kim, Yong-Su; Ma, Lijun; Tang, Xiao

    2012-10-01

    A Volume Bragg Grating (VBG) can be used to efficiently extract a narrow bandwidth, highly collimated beam from an otherwise broad spectrum beam. We use a VBG to extract a narrow bandwidth of signal spectrum from a broadband Spontaneous Parametric Down-Conversion source to optimally match the narrow detection bandwidth of our idler upconversion detector. Improved coincidence count rates and visibility can be achieved when limiting signal-spectrum detection to the narrow signal bandwidth whose photons are correlated with a narrow idler-spectrum bandwidth that has been selected by the up-conversion detector. We compare coincidence count rate and visibility for when the entire signal spectrum is detected and when the spectrum has been filtered by the VBG. We further relax the collection techniques and show that following the VBG, the coincidence count rate improves with minimal loss in visibility compared to when the entire spectrum is detected. We introduce our initial efforts at using the VBG to further narrow the signal spectrum by placing it inside a multipass cavity. Additionally, we further adapt the single photon level up-conversion spectrometer, previously developed for idler spectrum measurement, to indirectly measure the single photon level signal spectrum. We verify its capability for several different wavelength and linewidth selections.

  16. Ultra-High Density Holographic Memory Module with Solid-State Architecture

    NASA Technical Reports Server (NTRS)

    Markov, Vladimir B.

    2000-01-01

    NASA's terrestrial. space, and deep-space missions require technology that allows storing. retrieving, and processing a large volume of information. Holographic memory offers high-density data storage with parallel access and high throughput. Several methods exist for data multiplexing based on the fundamental principles of volume hologram selectivity. We recently demonstrated that a spatial (amplitude-phase) encoding of the reference wave (SERW) looks promising as a way to increase the storage density. The SERW hologram offers a method other than traditional methods of selectivity, such as spatial de-correlation between recorded and reconstruction fields, In this report we present the experimental results of the SERW-hologram memory module with solid-state architecture, which is of particular interest for space operations.

  17. Baryons in holographic QCD

    SciTech Connect

    Nawa, Kanabu; Suganuma, Hideo; Kojo, Toru

    2007-04-15

    We study baryons in holographic QCD with D4/D8/D8 multi-D-brane system. In holographic QCD, the baryon appears as a topologically nontrivial chiral soliton in a four-dimensional effective theory of mesons. We call this topological soliton brane-induced Skyrmion. Some review of D4/D8/D8 holographic QCD is presented from the viewpoints of recent hadron physics and QCD phenomenologies. A four-dimensional effective theory with pions and {rho} mesons is uniquely derived from the non-Abelian Dirac-Born-Infeld (DBI) action of D8 brane with D4 supergravity background at the leading order of large N{sub c}, without small amplitude expansion of meson fields to discuss chiral solitons. For the hedgehog configuration of pion and {rho}-meson fields, we derive the energy functional and the Euler-Lagrange equation of brane-induced Skyrmion from the meson effective action induced by holographic QCD. Performing the numerical calculation, we obtain the soliton solution and figure out the pion profile F(r) and the {rho}-meson profile G-tilde(r) of the brane-induced Skyrmion with its total energy, energy density distribution, and root-mean-square radius. These results are compared with the experimental quantities of baryons and also with the profiles of standard Skyrmion without {rho} mesons. We analyze interaction terms of pions and {rho} mesons in brane-induced Skyrmion, and find a significant {rho}-meson component appearing in the core region of a baryon.

  18. Holographic subsonic flow visualization.

    PubMed

    Reinheimer, C J; Wiswall, C E; Schmiege, R A; Harris, R J; Dueker, J E

    1970-09-01

    A pulsed ruby laser holographic interferometer was used to detect density gradients in the airflow around an airfoil at subsonic speeds in a low speed wind tunnel. These experiments proved that vibration of the optical components or object between exposures of the interferometric hologram does not destroy the detection of density gradients but actually can aid in the flow visualization. The density gradients determined from the fringe pattern analysis are consistent with the anticipated flow pattern. PMID:20094197

  19. Holographic Plossl Retroreflectors

    NASA Technical Reports Server (NTRS)

    Waluschka, Eugene

    2006-01-01

    Holographic retroreflectors that function equivalently to Plossl eyepieces have been developed and used in free-space optical communication systems that utilize laser beams. Plossl eyepieces are well known among telescope designers. They have been adopted for use a retroreflectors and as focusing elements (for reception) and collimating elements (for transmission) in optical communication systems. A retro-reflector that incorporates a Plossl eyepiece is termed a cat's-eye retroreflector.

  20. Holographic Airborne Rotating Lidar Instrument Experiment (HARLIE)

    NASA Technical Reports Server (NTRS)

    Schwemmer, Geary K.

    1998-01-01

    Scanning holographic lidar receivers are currently in use in two operational lidar systems, PHASERS (Prototype Holographic Atmospheric Scanner for Environmental Remote Sensing) and now HARLIE (Holographic Airborne Rotating Lidar Instrument Experiment). These systems are based on volume phase holograms made in dichromated gelatin (DCG) sandwiched between 2 layers of high quality float glass. They have demonstrated the practical application of this technology to compact scanning lidar systems at 532 and 1064 nm wavelengths, the ability to withstand moderately high laser power and energy loading, sufficient optical quality for most direct detection systems, overall efficiencies rivaling conventional receivers, and the stability to last several years under typical lidar system environments. Their size and weight are approximately half of similar performing scanning systems using reflective optics. The cost of holographic systems will eventually be lower than the reflective optical systems depending on their degree of commercialization. There are a number of applications that require or can greatly benefit from a scanning capability. Several of these are airborne systems, which either use focal plane scanning, as in the Laser Vegetation Imaging System or use primary aperture scanning, as in the Airborne Oceanographic Lidar or the Large Aperture Scanning Airborne Lidar. The latter class requires a large clear aperture opening or window in the aircraft. This type of system can greatly benefit from the use of scanning transmission holograms of the HARLIE type because the clear aperture required is only about 25% larger than the collecting aperture as opposed to 200-300% larger for scan angles of 45 degrees off nadir.

  1. Investigation of Holographic Scanners

    NASA Astrophysics Data System (ADS)

    Xiang, Lian Qin

    Holographic scanners are capable of challenging both the speed and resolution of polygon scanners. This work investigates, in detail, the design and operation of a holographic scanner with an aspherical reflector. The characteristics of this holographic scanner are presented through theoretical analyses and computer simulation. The calculated data and the experimental results show that this system has excellent scan line straightness and scan linearity. The influence of the eccentricity and wobble of the hologram on the quality of the scan lines can be minimized by proper choice of system parameters. This unique system can readily perform 1-D, 2 -D, 3-D and selective scans. These features make suitable applications for robot vision, part inspection, high speed printing, and input/output devices for computers. If the hologram is operating in the reflective mode, there are no transmissive components in this scanner. It can be used with acoustic waves and electromagnetic waves with longer wavelengths, such as infrared, microwaves, millimeter waves. Since it is difficult to find a suitable recording material for these waves, a technique for making computer -generated holograms has also been developed here. The practical considerations for making quality holograms are summarized. An improved coating process for photoresist and a novel anti-reflection setup for the hologram plate are developed. The detailed experimental processes are included. The planar grating scanner for one dimensional, two-dimensional and cross-scanning patterns is analyzed and demonstrated. A comparison is made with two other two-dimensional scanners.

  2. Holographic in-line imaging setup for measuring the solid content of fluids

    NASA Astrophysics Data System (ADS)

    Kaikkonen, Ville A.; Mäkynen, Anssi J.

    2013-05-01

    Digital in-line holographic microscopy is a captivating imaging method for industrial applications where large volumes of fluids are to be imaged with microscopic resolution. The lensless holographic in-line imaging setup with a point light source, also known as the Gabor setup, can be built up with just a few, fairly low cost, components. In-line holography is well suited for imaging large volumes with a low concentration of scattering particles as most of the light emitted from the point source should pass through the image volume unscattered. The large depth of field of in-line holographic microscopy makes it possible to image larger volumes with comparable resolutions than what can be achieved with traditional light microscopy methods using low magnification objectives. Despite the many advantages gained over traditional microscopic methods by the use of holographic imaging for large volumes, so far it has only been widely utilized in biological and particle image velocimetry studies. The large depth of field of the holographic microscope permits simultaneous imaging of particles located at different depths without the need for mechanical scanning, and allows the use of large diameter fluidic channels which are not as prone to clogging and enable higher flow rates than smaller fluidic channels. In this paper, we present a digital in-line holographic microscope based measurement principle for measuring the solid particle content of fluids. The method proposed is demonstrated on bio-oil samples whose solid contents are less than 0.01 weight percentage.

  3. Holographic contouring and its limitations in nearly specularly reflecting surface measurement

    NASA Astrophysics Data System (ADS)

    Lédl, Vít.; Psota, Pavel; Vojtíšek, Petr; Doleček, Roman; Mokrý, Pavel

    2015-01-01

    The applicability of the digital holography to grinded surfaces shape measurements is experimentally examined with regard to the surface micro-roughness of brittle materials (optical glass). Multi-wavelength phase shifted digital holographic interferometry (holographic contouring) is used and its performance is analyzed. Holographic contouring is a great candidate for the precise shape measurement technique, which can be applied to the iterative manufacture process of optical elements. Optical surface artifacts with different radii of the spherical (convex and concave) shapes were prepared with different micro-roughness. Their optical surfaces were then holographically recorded using a designed setup. Two different measures were selected to estimate the quality of the holographic recording: first, the intensity profile of the reconstructed surface deviation as a consequence of the micro-roughness decrease, where the shape of the intensity profile develops as the surface is altering from strongly diffusive to almost specular; second, the correlation of the phase fields (surfaces shapes), which were holographically recorded using two light beams of different wavelengths. In this situation, the correlation function decreases with an increase in the noise amount in data. The presented preliminary results indicate that the multi- wavelength holographic contouring can be used for surface measurements of high-quality polished and nearly specular surfaces. On the other hand, the application of holographic contouring to polished surface measurement still represents a challenging task and remains unresolved even with the multidirection illumination.

  4. SU-E-J-249: Correlation of Mean Lung Ventilation Value with Ratio of Total Lung Volumes

    SciTech Connect

    Yu, N; Qu, H; Xia, P

    2014-06-01

    Purpose: Lung ventilation function measured from 4D-CT and from breathing correlated CT images is a novel concept to incorporate the lung physiologic function into treatment planning of radiotherapy. The calculated ventilation functions may vary from different breathing patterns, affecting evaluation of the treatment plans. The purpose of this study is to correlate the mean lung ventilation value with the ratio of the total lung volumes obtained from the relevant CTs. Methods: A ventilation map was calculated from the variations of voxel-to-voxel CT densities from two breathing phases from either 4D-CT or breathing correlated CTs. An open source image registration tool of Plastimatch was used to deform the inhale phase images to the exhale phase images. To calculate the ventilation map inside lung, the whole lung was delineated and the tissue outside the lung was masked out. With a software tool developed in house, the 3D ventilation map was then converted in the DICOM format associated with the planning CT images. The ventilation map was analyzed on a clinical workstation. To correlate ventilation map thus calculated with lung volume change, the total lung volume change was compared the mean ventilation from our method. Results: Twenty two patients who underwent stereotactic body irradiation for lung cancer was selected for this retrospective study. For this group of patients, the ratio of lung volumes for the inhale (Vin ) and exhale phase (Vex ) was shown to be linearly related to the mean of the local ventilation (Vent), Vin/Vex=1.+0.49*Vent (R2=0.93, p<0.01). Conclusion: The total lung volume change is highly correlated with the mean of local ventilation. The mean of local ventilation may be useful to assess the patient's lung capacity.

  5. Method and apparatus for holographic wavefront diagnostics

    DOEpatents

    Toeppen, John S.

    1995-01-01

    A wavefront diagnostic apparatus has an optic and a measuring system. The optic forms a holographic image in response to a beam of light striking a hologram formed on a surface of the optic. The measuring system detects the position of the array of holographic images and compares the positions of the array of holographic images to a reference holographic image.

  6. Method and apparatus for holographic wavefront diagnostics

    DOEpatents

    Toeppen, J.S.

    1995-04-25

    A wavefront diagnostic apparatus has an optic and a measuring system. The optic forms a holographic image in response to a beam of light striking a hologram formed on a surface of the optic. The measuring system detects the position of the array of holographic images and compares the positions of the array of holographic images to a reference holographic image. 3 figs.

  7. Early visual processing for low spatial frequency fearful face is correlated with cortical volume in patients with schizophrenia.

    PubMed

    Lee, Jung Suk; Park, Gewnhi; Song, Myeong Ju; Choi, Kee-Hong; Lee, Seung-Hwan

    2016-01-01

    Patients with schizophrenia present with dysfunction of the magnocellular pathway, which might impair their early visual processing. We explored the relationship between functional abnormality of early visual processing and brain volumetric changes in schizophrenia. Eighteen patients and 16 healthy controls underwent electroencephalographic recordings and high-resolution magnetic resonance imaging. During electroencephalographic recordings, participants passively viewed neutral or fearful faces with broad, high, or low spatial frequency characteristics. Voxel-based morphometry was performed to investigate brain volume correlates of visual processing deficits. Event related potential analysis suggested that patients with schizophrenia had relatively impaired P100 processing of low spatial frequency fearful face stimuli compared with healthy controls; patients' gray-matter volumes in the dorsolateral and medial prefrontal cortices positively correlated with this amplitude. In addition, patients' gray-matter volume in the right cuneus positively correlated with the P100 amplitude in the left hemisphere for the high spatial frequency neutral face condition and that in the left dorsolateral prefrontal cortex negatively correlated with the negative score of the Positive and Negative Syndrome Scale. No significant correlations were observed in healthy controls. This study suggests that the cuneus and prefrontal cortex are significantly involved with the early visual processing of magnocellular input in patients with schizophrenia. PMID:26730192

  8. Detrended cross-correlations between returns, volatility, trading activity, and volume traded for the stock market companies

    NASA Astrophysics Data System (ADS)

    Rak, Rafał; Drożdż, Stanisław; Kwapień, Jarosław; Oświȩcimka, Paweł

    2015-11-01

    We consider a few quantities that characterize trading on a stock market in a fixed time interval: logarithmic returns, volatility, trading activity (i.e., the number of transactions), and volume traded. We search for the power-law cross-correlations among these quantities aggregated over different time units from 1 min to 10 min. Our study is based on empirical data from the American stock market consisting of tick-by-tick recordings of 31 stocks listed in Dow Jones Industrial Average during the years 2008-2011. Since all the considered quantities except the returns show strong daily patterns related to the variable trading activity in different parts of a day, which are the most evident in the autocorrelation function, we remove these patterns by detrending before we proceed further with our study. We apply the multifractal detrended cross-correlation analysis with sign preserving (MFCCA) and show that the strongest power-law cross-correlations exist between trading activity and volume traded, while the weakest ones exist (or even do not exist) between the returns and the remaining quantities. We also show that the strongest cross-correlations are carried by those parts of the signals that are characterized by large and medium variance. Our observation that the most convincing power-law cross-correlations occur between trading activity and volume traded reveals the existence of strong fractal-like coupling between these quantities.

  9. Laser addressed holographic memory system

    NASA Technical Reports Server (NTRS)

    Gange, R. A.; Wagle, E. M.; Steinmetz, C. C.

    1973-01-01

    Holographic recall and storage system uses red-lipid microcrystalline wax as storage medium. When laser beam strikes wax, its energy heats point of incidence enough to pass wax through transition temperature. Holograph image can then be written or erased in softened wax.

  10. Holoscopy--holographic optical coherence tomography.

    PubMed

    Hillmann, Dierck; Lührs, Christian; Bonin, Tim; Koch, Peter; Hüttmann, Gereon

    2011-07-01

    Scanning optical coherence tomography (OCT) is limited in sensitivity and resolution by the restricted focal depth of the confocal detection scheme. Holoscopy, a combination of holography and Fourier-domain full-field OCT, is proposed as a way to detect photons from all depths of a sample volume simultaneously with uniform sensitivity and lateral resolution, even at high NAs. By using the scalar diffraction theory, as frequently applied in digital holographic imaging, we fully reconstruct the object field with depth-invariant imaging quality. In vivo imaging of human skin is demonstrated with an image quality comparable to conventionally scanned OCT. PMID:21725421

  11. Digital holographic video for studies of plankton dynamics

    NASA Astrophysics Data System (ADS)

    Dyomin, V. V.; Olshukov, A. S.; Dzyuba, E. V.

    2011-01-01

    The procedure, capabilities, and applicability limits of digital holographic video for the determination of the velocity and reconstruction of the trajectory of motion of plankton species in the habitat are considered. Results of experimental investigations of zooplankton in laboratory conditions are presented. Two species that differ by the morphology and sizes are examined, including Epischura baicalensis for the trajectory construction and Daphnia magna for an experiment on dual-view hologram recording. The position of a plankton species in the examined volume is suggested to be determined based on the coordinates of the center of gravity of its holographic image. Preliminary results of recording of a dual-view digital holographic video of plankton species are discussed.

  12. Prototype Holographic Atmospheric Scanner for Environmental Remote Sensing (PHASERS)

    NASA Technical Reports Server (NTRS)

    Guerra, David V.; Schwemmer, Geary K.; Wooten, Albert D., Jr.; Chaudhuri, Sandipan S.; Wilkerson, Thomas D.

    1995-01-01

    A ground-based atmospheric lidar system that utilizes a Holographic Optical Telescope and Scanner has been developed and successfully operated to obtain atmospheric backscatter profiles. The Prototype Holographic Atmospheric Scanner for Environmental Remote Sensing is built around a volume phase reflection Holographic Optical Element. This single optical element both directs and collimates the outgoing laser beam as well as collects, focuses, and filters the atmospheric laser backscatter, while offering significant weight savings over existing telescope mirror technology. Conical scanning is accomplished as the HOE rotates on a turntable sweeping the 1.2 mrad field of view around a 42deg cone. During this technology demonstration, atmospheric aerosol and cloud return signals have been received in both stationary and scanning modes. The success of this program has led to the further development of this technology for integration into airborne and eventually satellite earth observing scanning lidar telescopes.

  13. Application of holographic optical techniques to bulk memory.

    NASA Technical Reports Server (NTRS)

    Anderson, L. K.

    1971-01-01

    Current efforts to exploit the spatial redundancy and built-in imaging of holographic optical techniques to provide high information densities without critical alignment and tight mechanical tolerances are reviewed. Read-write-erase in situ operation is possible but is presently impractical because of limitations in available recording media. As these are overcome, it should prove feasible to build holographic bulk memories with mechanically replaceable hologram plates featuring very fast (less than 2 microsec) random access to large (greater than 100 million bit) data blocks and very high throughput (greater than 500 Mbit/sec). Using volume holographic storage it may eventually be possible to realize random-access mass memories which require no mechanical motion and yet provide very high capacity.

  14. Towards an incoherent off-axis digital holographic microscope

    NASA Astrophysics Data System (ADS)

    Monemhaghdoust, Z.; De Gol, P.; Montfort, F.; Emery, Y.; Depeursinge, C.; Moser, C.

    2015-03-01

    We propose and experimentally demonstrate a system in which off-axis digital holographic microscopy is realized using a broadband illumination source. Single-shot holographic measurements are enabled, while the coherence noise is removed thanks to the broad bandwidth of the illuminating source. The proposed digital holographic camera is portable and can be attached to the camera port of a conventional optical microscope. This camera is capable of obtaining the complex wavefront i.e the intensity and phase information of the light transmitted or reflected from a sample. A combination of a thick transmission volume grating recorded holographically into thick photosensitive glass and thin transmission phase gratings recorded holographically into thin photopolymers, spatially filters the beam of light containing the sample information in two dimensions through diffraction. This filtered beam creates the reference arm of the interferometer. The untouched transmitted beam creates the sample arm of the interferometer. The spatial filtering performed by the combination of gratings above reduces the alignment spatial sensitivity which is an advantage over conventional spatial filtering done by pinholes. Besides, using a second thin grating, we introduce a desired coherence plane tilt in the reference beam which is sufficient to create high-visibility interference over the entire field of view in off-axis configuration. Full-field off-axis interferograms are thus created from which the phase information can be extracted.

  15. Robust holographic storage system design.

    PubMed

    Watanabe, Takahiro; Watanabe, Minoru

    2011-11-21

    Demand is increasing daily for large data storage systems that are useful for applications in spacecraft, space satellites, and space robots, which are all exposed to radiation-rich space environment. As candidates for use in space embedded systems, holographic storage systems are promising because they can easily provided the demanded large-storage capability. Particularly, holographic storage systems, which have no rotation mechanism, are demanded because they are virtually maintenance-free. Although a holographic memory itself is an extremely robust device even in a space radiation environment, its associated lasers and drive circuit devices are vulnerable. Such vulnerabilities sometimes engendered severe problems that prevent reading of all contents of the holographic memory, which is a turn-off failure mode of a laser array. This paper therefore presents a proposal for a recovery method for the turn-off failure mode of a laser array on a holographic storage system, and describes results of an experimental demonstration. PMID:22109441

  16. Neuroanatomical correlates of the sense of control: Gray and white matter volumes associated with an internal locus of control.

    PubMed

    Hashimoto, Teruo; Takeuchi, Hikaru; Taki, Yasuyuki; Sekiguchi, Atsushi; Nouchi, Rui; Kotozaki, Yuka; Nakagawa, Seishu; Miyauchi, Carlos Makoto; Iizuka, Kunio; Yokoyama, Ryoichi; Shinada, Takamitsu; Yamamoto, Yuki; Hanawa, Sugiko; Araki, Tsuyoshi; Hashizume, Hiroshi; Kunitoki, Keiko; Kawashima, Ryuta

    2015-10-01

    A belief that effort is rewarded can develop incentive, achievement motivation, and self-efficacy. Individuals with such a belief attribute causes of events to themselves, not to external, uncontrollable factors, and are thus said to have an internal locus of control. An internal locus of control is a positive personality trait and has been thoroughly studied in applied psychology, but has not been widely examined in neuroscience. In the present study, correlations between locus of control assessment scores and brain volumes were examined in 777 healthy young adults using magnetic resonance imaging. A whole-brain multiple regression analysis with corrections for the effects of age, gender, and intelligence was conducted. Voxel-based morphometry analyses revealed that gray matter volumes in the anterior cingulate cortex, striatum, and anterior insula positively correlated with higher scores, which indicate an internal LOC. In addition, white matter volumes in the striatum showed significant correlations with an internal locus of control. These results suggest that cognitive, socioemotional, self-regulatory, and reward systems might be associated with internal control orientation. The finding of greater volumes in several brain regions in individuals with a stronger internal locus of control indicates that there is a neuroanatomical basis for the belief that one's efforts are rewarded. PMID:26123375

  17. Holographic movie: the first step to holographic video

    NASA Astrophysics Data System (ADS)

    Higuchi, Kazuhito; Ishikawa, Jun; Hiyama, Shigeo

    1992-05-01

    Holographic movies can be seen as a tool to estimate the picture quality of moving holographic images as a step towards holographic television. With this in mind, we have developed an experimental holographic movie system and produced a short duration 3D movie. A number of dolls and moving objects were positioned within a background and illuminated with a He-Ne laser (632.8 nm). Conventional film-making techniques were used during holographic recording to create a more attractive sequence. The techniques included stop-motion, tracking, enhanced depth perception, up-shots, and overlaps. A series of 300 Fresnel type holograms was recorded on standard holographic films. An interesting technical point is that the film was 10 mm high by 200 mm wide. After developing, the films were sandwiched between two rigid acrylic drums (about 1 m in diameter). The drum is rotated and the films illuminated with the He-Ne laser. The display speed can be varied from 6 to 24 frames per second. The films are viewed through a window. Even though this prototype is relatively primitive the resulting holographic movie is quite effective. Several interesting effects were noted. For example, it was found that objects in the movie must not rapidly shift their depth because the human eye cannot track them is they do.

  18. Characteristics of volume polarization holography with linear polarization light

    NASA Astrophysics Data System (ADS)

    Zang, Jinliang; Wu, An'an; Liu, Ying; Wang, Jue; Lin, Xiao; Tan, Xiaodi; Shimura, Tsutomu; Kuroda, Kazuo

    2015-10-01

    Volume polarization holographic recording in phenanthrenequinone-doped poly(methyl methacrylate) (PQ-PMMA) photopolymer with linear polarized light is obtained. The characteristics of the volume polarization hologram are experimentally investigated. It is found that beyond the paraxial approximation the polarization states of the holographic reconstruction light are generally different from the signal light. Based on vector wave theoretical analyses and material properties, the special exposure condition for correctly holographic reconstruction is obtained and experimentally demonstrated.

  19. Correcting Correlations When Predicting Success in College. IR Applications. Volume 31

    ERIC Educational Resources Information Center

    Saupe, Joe L.; Eimers, Mardy T.

    2011-01-01

    Critics of testing for admission purposes cite the moderate correlations of admissions test scores with success in college. In response, this study applies formulas from classical measurement theory to observed correlations to correct for restricted variances in predictor and success variables. Estimates of the correlations in the population of…

  20. Determination of correlation between backflow volume and mitral valve leaflet young modulus from two dimensional echocardiogram images

    NASA Astrophysics Data System (ADS)

    Jong, Rudiyanto P.; Osman, Kahar; Adib, M. Azrul Hisham M.

    2012-06-01

    Mitral valve prolapse without proper monitoring might lead to a severe mitral valve failure which eventually leads to a sudden death. Additional information on the mitral valve leaflet condition against the backflow volume would be an added advantage to the medical practitioner for their decision on the patients' treatment. A study on two dimensional echocardiography images has been conducted and the correlations between the backflow volume of the mitral regurgitation and mitral valve leaflet Young modulus have been obtained. Echocardiogram images were analyzed on the aspect of backflow volume percentage and mitral valve leaflet dimensions on different rates of backflow volume. Young modulus values for the mitral valve leaflet were obtained by using the principle of elastic deflection and deformation on the mitral valve leaflet. The results show that the backflow volume increased with the decrease of the mitral valve leaflet Young modulus which also indicate the condition of the mitral valve leaflet approaching failure at high backflow volumes. Mitral valve leaflet Young modulus values obtained in this study agreed with the healthy mitral valve leaflet Young modulus from the literature. This is an initial overview of the trend on the prediction of the behaviour between the fluid and the structure of the blood and the mitral valve which is extendable to a larger system of prediction on the mitral valve leaflet condition based on the available echocardiogram images.

  1. Predictability and Market Efficiency in Agricultural Futures Markets: a Perspective from Price-Volume Correlation Based on Wavelet Coherency Analysis

    NASA Astrophysics Data System (ADS)

    He, Ling-Yun; Wen, Xing-Chun

    2015-12-01

    In this paper, we use a time-frequency domain technique, namely, wavelet squared coherency, to examine the associations between the trading volumes of three agricultural futures and three different forms of these futures' daily closing prices, i.e. prices, returns and volatilities, over the past several years. These agricultural futures markets are selected from China as a typical case of the emerging countries, and from the US as a representative of the developed economies. We investigate correlations and lead-lag relationships between the trading volumes and the prices to detect the predictability and efficiency of these futures markets. The results suggest that the information contained in the trading volumes of the three agricultural futures markets in China can be applied to predict the prices or returns, while that in US has extremely weak predictive power for prices or returns. We also conduct the wavelet analysis on the relationships between the volumes and returns or volatilities to examine the existence of the two "stylized facts" proposed by Karpoff [J. M. Karpoff, The relation between price changes and trading volume: A survey, J. Financ. Quant. Anal.22(1) (1987) 109-126]. Different markets in the two countries perform differently in reproducing the two stylized facts. As the wavelet tools can decode nonlinear regularities and hidden patterns behind price-volume relationship in time-frequency space, different from the conventional econometric framework, this paper offers a new perspective into the market predictability and efficiency.

  2. Two-step phase-shifting fluorescence incoherent holographic microscopy

    PubMed Central

    Qin, Wan; Yang, Xiaoqi; Li, Yingying; Peng, Xiang; Yao, Hai; Qu, Xinghua; Gao, Bruce Z.

    2014-01-01

    Abstract. Fluorescence holographic microscope (FINCHSCOPE) is a motionless fluorescence holographic imaging technique based on Fresnel incoherent correlation holography (FINCH) that shows promise in reconstructing three-dimensional fluorescence images of biological specimens with three holograms. We report a developing two-step phase-shifting method that reduces the required number of holograms from three to two. Using this method, we resolved microscopic fluorescent beads that were three-dimensionally distributed at different depths with two interferograms captured by a CCD camera. The method enables the FINCHSCOPE to work in conjunction with the frame-straddling technique and significantly enhance imaging speed. PMID:24972355

  3. Photopolymerizable nanocomposite photonic materials and their holographic applications in light and neutron optics

    PubMed Central

    Tomita, Yasuo; Hata, Eiji; Momose, Keisuke; Takayama, Shingo; Liu, Xiangming; Chikama, Katsumi; Klepp, Jürgen; Pruner, Christian; Fally, Martin

    2016-01-01

    We present an overview of recent investigations of photopolymerizable nanocomposite photonic materials in which, thanks to their high degree of material selectivity, recorded volume gratings possess high refractive index modulation amplitude and high mechanical/thermal stability at the same time, providing versatile applications in light and neutron optics. We discuss the mechanism of grating formation in holographically exposed nanocomposite materials, based on a model of the photopolymerization-driven mutual diffusion of monomer and nanoparticles. Experimental inspection of the recorded grating’s morphology by various physicochemical and optical methods is described. We then outline the holographic recording properties of volume gratings recorded in photopolymerizable nanocomposite materials consisting of inorganic/organic nanoparticles and monomers having various photopolymerization mechanisms. Finally, we show two examples of our holographic applications, holographic digital data storage and slow-neutron beam control. PMID:27594769

  4. Holographic model of hadronization.

    PubMed

    Evans, Nick; Tedder, Andrew

    2008-04-25

    We study hadronization of the final state in a particle-antiparticle annihilation using a holographic gravity dual description of QCD. At the point of hadronization we match the events to a simple (Gaussian) energy distribution in the five dimensional theory. The final state multiplicities are then modeled by calculating the overlap between the Gaussian and a set of functions in the fifth dimension which represent each hadron. We compare our results to those measured in e(+)e(-) collisions. Hadron production numbers over a range of 4 orders of magnitude are reproduced well. PMID:18518189

  5. Holographic Model of Hadronization

    SciTech Connect

    Evans, Nick; Tedder, Andrew

    2008-04-25

    We study hadronization of the final state in a particle-antiparticle annihilation using a holographic gravity dual description of QCD. At the point of hadronization we match the events to a simple (Gaussian) energy distribution in the five dimensional theory. The final state multiplicities are then modeled by calculating the overlap between the Gaussian and a set of functions in the fifth dimension which represent each hadron. We compare our results to those measured in e{sup +}e{sup -} collisions. Hadron production numbers over a range of 4 orders of magnitude are reproduced well.

  6. Simplification of holographic procedures.

    PubMed

    Carcel, J T; Rodemann, A H; Florman, E; Domeshek, S

    1966-07-01

    The present state of the holographic art has set many stringent parameters on the production of holograms, such as extreme mechanical, temperature, and air stability for long periods of time, and slow film emulsions with extremely high resolution. The Physical Sciences Laboratory of the U.S. Naval Training Device Center has investigated, experimented, and produced many clear high resolution holograms in a ground-level Butler Building without close temperature controls and using other than expensive, massive, and extremely rigid optical mounts and equipment. PMID:20049046

  7. Holographic twin Higgs model.

    PubMed

    Geller, Michael; Telem, Ofri

    2015-05-15

    We present the first realization of a "twin Higgs" model as a holographic composite Higgs model. Uniquely among composite Higgs models, the Higgs potential is protected by a new standard model (SM) singlet elementary "mirror" sector at the sigma model scale f and not by the composite states at m_{KK}, naturally allowing for m_{KK} beyond the LHC reach. As a result, naturalness in our model cannot be constrained by the LHC, but may be probed by precision Higgs measurements at future lepton colliders, and by direct searches for Kaluza-Klein excitations at a 100 TeV collider. PMID:26024160

  8. Holographic magnetic phase transition

    SciTech Connect

    Lifschytz, Gilad; Lippert, Matthew

    2009-09-15

    We study four-dimensional interacting fermions in a strong magnetic field, using the holographic Sakai-Sugimoto model of intersecting D4- and D8-branes in the deconfined, chiral-symmetric parallel phase. We find that as the magnetic field is varied, while staying in the parallel phase, the fermions exhibit a first-order phase transition in which their magnetization jumps discontinuously. Properties of this transition are consistent with a picture in which some of the fermions jump to the lowest Landau level. Similarities to known magnetic phase transitions are discussed.

  9. Holographic effective field theories

    NASA Astrophysics Data System (ADS)

    Martucci, Luca; Zaffaroni, Alberto

    2016-06-01

    We derive the four-dimensional low-energy effective field theory governing the moduli space of strongly coupled superconformal quiver gauge theories associated with D3-branes at Calabi-Yau conical singularities in the holographic regime of validity. We use the dual supergravity description provided by warped resolved conical geometries with mobile D3-branes. Information on the baryonic directions of the moduli space is also obtained by using wrapped Euclidean D3-branes. We illustrate our general results by discussing in detail their application to the Klebanov-Witten model.

  10. Interferometric holographic cinematography

    NASA Astrophysics Data System (ADS)

    Fagot, H.

    1985-07-01

    Double exposition holographic interferometry was employed to obtain a 35 mm scientific film. The deformations and deplacements of a loudspeaker were visualized at 20 to 70 Hz vibration frequencies. A 30 mJ YAG laser was used. The two successive pulses of each hologram are produced at 4 ms interval by the same laser beam. The 35 mm camera operates at 10 Hz. The device is limited to low frequency phenomena. The development of higher frequency systems is discussed with a view to nondestructive control of vibration in aircraft structures.

  11. Direct correlation between free volume and dielectric constant in a fluorine-containing polyimide blend

    NASA Astrophysics Data System (ADS)

    Ramani, R.; Ramachandran, R.; Amarendra, G.; Alam, S.

    2015-06-01

    The dielectric constant of fluorinated polyimides and their blends is known to decrease with increase in free volume due to decrease in the number of polarizable groups per unit volume. Interestingly, we report here a polyimide which when blended with a fluoro- polymer showed a positive deviation of dielectric constant with free volume. In our experiment, we have used a blend of poly(ether imide) and poly(vinylidene fluorine-co-hexafluoropropylene) and the interaction between them was studied using FTIR, XRD, TGA and SEM. The blend was investigated by PALS, DB and DEA. Surprisingly, with the increase in the free volume content in this blend, the dielectric constant also increases. This change is attributed to additional space available for the polarizable groups to orient themselves to the applied electric field.

  12. Holographic Labeling And Reading Machine For Authentication And Security Appications

    DOEpatents

    Weber, David C.; Trolinger, James D.

    1999-07-06

    A holographic security label and automated reading machine for marking and subsequently authenticating any object such as an identification badge, a pass, a ticket, a manufactured part, or a package is described. The security label is extremely difficult to copy or even to read by unauthorized persons. The system comprises a holographic security label that has been created with a coded reference wave, whose specification can be kept secret. The label contains information that can be extracted only with the coded reference wave, which is derived from a holographic key, which restricts access of the information to only the possessor of the key. A reading machine accesses the information contained in the label and compares it with data stored in the machine through the application of a joint transform correlator, which is also equipped with a reference hologram that adds additional security to the procedure.

  13. Correlation of the Peach Springs Tuff, a large-volume Miocene ignimbrite sheet in California and Arizona ( USA).

    USGS Publications Warehouse

    Glazner, A.F.; Nielson, J.E.; Howard, K.A.; Miller, D.M.

    1986-01-01

    The Peach Springs Tuff is a distinctive early Miocene ignimbrite deposit that was first recognized in western Arizona. Recent field studies and phenocryst analyses indicate that adjacent outcrops of similar tuff in the central and eastern Mojave Desert may be correlative. This proposed correlation implies that outcrops of the tuff are scattered over an area of at least 35 000 km2 from the western Colorado Plateau to Barstow, California, and that the erupted volume, allowing for posteruption crustal extension, was at least several hundred cubic kilometres. Thus, the Peach Springs Tuff may be a regional stratigraphic marker, useful for determining regional paleogeography and the time and extent of Tertiary crustal extension. -Authors

  14. Volume overload correlates with cardiovascular risk factors in patients with chronic kidney disease.

    PubMed

    Hung, Szu-Chun; Kuo, Ko-Lin; Peng, Ching-Hsiu; Wu, Che-Hsiung; Lien, Yu-Chung; Wang, Yi-Chun; Tarng, Der-Cherng

    2014-03-01

    Volume overload is a predictor of mortality in dialysis patients. However, the fluid status of patients with chronic kidney disease (CKD) but not yet on dialysis has not been accurately characterized. We used the Body Composition Monitor, a multifrequency bioimpedance device, to measure the level of overhydration in CKD patients, focusing on the association between overhydration and cardiovascular disease risk factors. Overhydration was the difference between the amount of extracellular water measured by the Body Composition Monitor and the amount of water predicted under healthy euvolemic conditions. Volume overload was defined as an overhydration value at and above the 90th percentile for the normal population. Of the 338 patients with stages 3-5 CKD, only 48% were euvolemic. Patients with volume overload were found to use significantly more antihypertensive medications and diuretics but had higher systolic blood pressures and an increased arterial stiffness than patients without volume overload. In a multivariate analysis, male sex, diabetes, pre-existing cardiovascular disease, systolic blood pressure, serum albumin, TNF-α, and proteinuria were independently all associated with overhydration. Thus, volume overload is strongly associated with both traditional and novel risk factors for cardiovascular disease. Bioimpedance devices may aid in clinical assessment by helping to identify a high-risk group with volume overload among stages 3-5 CKD patients. PMID:24025647

  15. Improvements of a spatial frequency analyzer for automated characterization of holographic recording materials.

    PubMed

    Couture, J J; Tanguay, D

    1992-05-10

    A spatial frequency analyzer was designed to simplify characterization studies for new holographic recording materials. Mechanical movements were automated and a complete informational system gave rapid characterization results. A good fringe stabilization unit was improved by adding simple holographic optical beam combiners. Experimental characterization of two different recording materials shows the versatility of this automated apparatus. Also we present modulation-transfer-function curves of dichromated gelatin between 500 and 3500 cycles/mm obtained with polarization volume transmission holograms. PMID:20725176

  16. Multifunctional photoreactive inorganic cages for three-dimensional holographic data storage.

    PubMed

    Lee, Seungwoo; Jeong, Yong-Cheol; Lee, Jihye; Park, Jung-Ki

    2009-10-15

    We demonstrate a holographic photopolymer based on multifunctional photoreactive inorganic cages, polyhedral oligomeric silsesquioxane (POSS). It is shown that a second photopolymerizable monomer, POSS, for the photopolymer, contributes to significantly enhance photosensitivity as well as refractive index modulation (Deltan). We also found that during the formation of holographic gratings, polymerization of POSS could effectively suppress volume shrinkage of photopolymer resin, owing to its filler-strengthening effect of inorganic cages accompanied with interpenetrating effect. PMID:19838237

  17. Inflation with holographic dark energy

    NASA Astrophysics Data System (ADS)

    Chen, Bin; Li, Miao; Wang, Yi

    2007-07-01

    We investigate the corrections of the holographic dark energy to inflation paradigm. We study the evolution of the holographic dark energy in the inflationary universe in detail, and carry out a model-independent analysis on the holographic dark energy corrections to the primordial scalar power spectrum. It turns out that the corrections generically make the spectrum redder. To be consistent with the experimental data, there must be a upper bound on the reheating temperature. We also discuss the corrections due to different choices of the infrared cutoff.

  18. Intellectual property in holographic interferometry

    NASA Astrophysics Data System (ADS)

    Reingand, Nadya; Hunt, David

    2006-08-01

    This paper presents an overview of patents and patent applications on holographic interferometry, and highlights the possibilities offered by patent searching and analysis. Thousands of patent documents relevant to holographic interferometry were uncovered by the study. The search was performed in the following databases: U.S. Patent Office, European Patent Office, Japanese Patent Office and Korean Patent Office for the time frame from 1971 through May 2006. The patent analysis unveils trends in patent temporal distribution, patent families formation, significant technological coverage within the market of system that employ holographic interferometry and other interesting insights.

  19. Conically scanned holographic lidar telescope

    NASA Technical Reports Server (NTRS)

    Schwemmer, Geary (Inventor)

    1993-01-01

    An optical scanning device utilizing a source of optical energy such as laser light backscattered from the earth's atmosphere or transmitted outward as in a lidar, a rotating holographic optical element having an axis of rotation perpendicular to the plane of its substrate, and having a stationary focus which may or may not be located on its axis of rotation, with the holographic optical element diffracting the source of optical energy at an angle to its rotation axis enabling a conical scanning area and a motor for supporting and rotating the rotating holographic optical element, is described.

  20. Dermatoglyphic correlates of hippocampus volume: Evaluation of aberrant neurodevelopmental markers in antipsychotic-naïve schizophrenia.

    PubMed

    Kalmady, Sunil V; Shivakumar, Venkataram; Gautham, S; Arasappa, Rashmi; Jose, Dania A; Venkatasubramanian, Ganesan; Gangadhar, B N

    2015-10-30

    Schizophrenia is a disorder of aberrant neurodevelopment is marked by abnormalities in brain structure and dermatoglyphic traits. However, the link between these two (i.e. dermatoglyphic parameters and brain structure) which share ectodermal origin and common developmental window has not been explored extensively. The current study examined dermatoglyphic correlates of hippocampal volume in antipsychotic-naïve schizophrenia patients in comparison with matched healthy controls. Ridge counts and asymmetry measures for palmar inter-digital areas (a-b, b-c, c-d) were obtained using high resolution digital scans of palms from 89 schizophrenia patients [M:F=48:41] and 48 healthy controls [M:F=30:18]. Brain scans were obtained for subset of subjects including 26 antipsychotic-naïve patients [M:F=13:13] and 29 healthy controls [M:F=19:10] using 3 T-MRI. Hippocampal volume and palmar ridge counts were measured by blinded raters with good inter-rater reliability using valid methods. Directional asymmetry (DA) of b-c and bilateral hippocampal volume were significantly lower in patients than controls. Significant positive correlation was found between DA and ridge count of b-c with bilateral anterior hippocampal volume. Study demonstrates the utility of dermatoglyphic markers in identifying structural changes in the brain which may form the basis for neurodevelopmental pathogenesis in schizophrenia. PMID:26385539

  1. New holographic overlays

    NASA Astrophysics Data System (ADS)

    Hopwood, Anthony I.

    1991-10-01

    This paper discusses a new type of holographic overlay, FLASHPRINT, which may be used in both security and packaging applications. Unlike the more common embossed holograms currently used, FLASHPRINT leads to reduced set-up costs and offers a simpler process. This reduces the long lead times characteristic of the existing technology and requires the customer to provide only two-dimensional artwork. The overlay material contains a covert 2-D image. The image may be switched on or off by simply tilting the overlay in a light source. The overlay is replayed in the 'on' position to reveal the encoded security message as a highly saturated gold colored image. This effect is operable for a wide range of lighting conditions and viewing geometries. In the 'off' position the overlay is substantially transparent. These features make the visual effect of the overlay attractive to incorporate into product design. They may be laminated over complex printed artwork such as labels and security passes without masking the printed message. When switched 'on' the image appears both sharp and more than seven times brighter than white paper. The image remains sharp and clear even in less favorable lighting conditions. Although the technique offers a low set-up cost for the customer, through its simplicity, it remains as technically demanding and difficult to counterfeit as any holographic process.

  2. Engineering holographic graphene

    SciTech Connect

    Semenoff, Gordon W.

    2012-09-24

    We present a top-down string theory holographic model of strongly interacting relativistic 2 + 1-dimensional fermions, paying careful attention to the discrete symmetries of parity and time reversal invariance. Our construction is based on probe D7-branes in AdS{sub 5} Multiplication-Sign S{sup 5}, stabilized by internal fluxes. We find three solutions, a parity and time reversal invariant conformal field theory which can be viewed as a particular deformation of Coulomb interacting graphene, a parity and time reversal violating but gapless field theory and a system with a parity and time reversal violating charge gap. We show that the Chern-Simons-like electric response function, which is generated perturbatively at one-loop order by parity violating fermions and which is protected by a no-renormalization theorem at orders beyond one loop, indeed appears with the correctly quantized coefficient in the charge gapped theory. In the gapless parity violating solution, the Chern-Simons response function obtains quantum corrections which we compute in the holographic theory.

  3. Holographic p -wave superfluid

    NASA Astrophysics Data System (ADS)

    Wu, Ya-Bo; Lu, Jun-Wang; Zhang, Wen-Xin; Zhang, Cheng-Yuan; Lu, Jian-Bo; Yu, Fang

    2014-12-01

    In the probe limit, we numerically construct a holographic p -wave superfluid model in the four-dimensional (4D) and five-dimensional (5D) anti-de Sitter black holes coupled to a Maxwell-complex vector field. We find that, for the condensate with the fixed superfluid velocity, the results are similar to the s -wave cases in both 4D and 5D spacetimes. In particular, the Cave of Winds and the phase transition, always being of second order, take place in the 5D case. Moreover, we find that the translating superfluid velocity from second order to first order S/yμ increases with the mass squared. Furthermore, for the supercurrent with fixed temperature, the results agree with the Ginzburg-Landau prediction near the critical temperature. In addition, this complex vector superfluid model is still a generalization of the SU(2) superfluid model, and it also provides a holographic realization of the H e3 superfluid system.

  4. Holographic Solar Photon Thrusters

    NASA Technical Reports Server (NTRS)

    Johnson, Les; Matloff, Greg

    2006-01-01

    A document discusses a proposal to incorporate holographic optical elements into solar photon thrusters (SPTs). First suggested in 1990, SPTs would be systems of multiple reflective, emissive, and absorptive surfaces (solar sails) that would be attached to spacecraft orbiting the Earth to derive small propulsive forces from radiation pressures. An SPT according to the proposal would include, among other things, a main sail. One side of the sail would be highly emissive and would normally face away from the Earth. The other side would be reflective and would be covered by white-light holographic images that would alternately become reflective, transmissive, and absorptive with small changes in the viewing angle. When the spacecraft was at a favorable orbital position, the main sail would be oriented to reflect sunlight in a direction to maximize the solar thrust; when not in a favorable position, the main sail would be oriented to present a substantially absorptive/emissive aspect to minimize the solar drag. By turning the main sail slightly to alternate between the reflective and absorptive/ emissive extremes, one could achieve nearly a doubling or halving of the radiational momentum transfer and, hence, of the solar thrust.

  5. Measurement of lacunar bone strains and crack formation during tensile loading by digital volume correlation of second harmonic generation images.

    PubMed

    Wentzell, Scott; Nesbitt, Robert Sterling; Macione, James; Kotha, Shiva

    2016-07-01

    The maintenance of healthy bone tissue depends upon the ability of osteocytes to respond to mechanical cues on the cellular level. The combination of digital volume correlation and second harmonic generation microscopy offers the opportunity to investigate the mechanical microenvironment of intact bone on the scale of individual osteocytes. Adult human femurs were imaged under tensile loads of 5 and 15MPa and volumes of approximately 492×429×31μm(3) were analyzed, along with an image of a bone microcrack under the same loading conditions. Principal strains were significantly higher in three-dimensional digital volume correlation when compared to two-dimensional digital image correlation. The average maximum principal strain magnitude was 5.06-fold greater than the applied global strain, with peak strains of up to 23.14-fold over global strains measured at the borders of osteocyte lacunae. Finally, a microcrack that initiated at an osteocyte lacunae had its greatest tensile strain magnitudes at the crack expansion front in the direction of a second lacunae, but strain at the crack border was reduced to background strain magnitudes upon breaching the second lacunae. This serveed to demonstrate the role of lacunae in initiating, mediating and terminating microcrack growth. PMID:26807766

  6. Electrophysiological Correlates of Emotional Content and Volume Level in Spoken Word Processing

    PubMed Central

    Grass, Annika; Bayer, Mareike; Schacht, Annekathrin

    2016-01-01

    For visual stimuli of emotional content as pictures and written words, stimulus size has been shown to increase emotion effects in the early posterior negativity (EPN), a component of event-related potentials (ERPs) indexing attention allocation during visual sensory encoding. In the present study, we addressed the question whether this enhanced relevance of larger (visual) stimuli might generalize to the auditory domain and whether auditory emotion effects are modulated by volume. Therefore, subjects were listening to spoken words with emotional or neutral content, played at two different volume levels, while ERPs were recorded. Negative emotional content led to an increased frontal positivity and parieto-occipital negativity—a scalp distribution similar to the EPN—between ~370 and 530 ms. Importantly, this emotion-related ERP component was not modulated by differences in volume level, which impacted early auditory processing, as reflected in increased amplitudes of the N1 (80–130 ms) and P2 (130–265 ms) components as hypothesized. However, contrary to effects of stimulus size in the visual domain, volume level did not influence later ERP components. These findings indicate modality-specific and functionally independent processing triggered by emotional content of spoken words and volume level. PMID:27458359

  7. Modelflow Estimates of Stroke Volume Do Not Correlate With Doppler Ultrasound Estimates During Upright Posture

    NASA Technical Reports Server (NTRS)

    Ferguson, Connor R.; Lee, Stuart M. C.; Stenger, Michael B.; Platts, Steven H.; Laurie, Steven S.

    2014-01-01

    Orthostatic intolerance affects 60-80% of astronauts returning from long-duration missions, representing a significant risk to completing mission-critical tasks. While likely multifactorial, a reduction in stroke volume (SV) represents one factor contributing to orthostatic intolerance during stand and head up tilt (HUT) tests. Current measures of SV during stand or HUT tests use Doppler ultrasound and require a trained operator and specialized equipment, restricting its use in the field. BeatScope (Finapres Medical Systems BV, The Netherlands) uses a modelflow algorithm to estimate SV from continuous blood pressure waveforms in supine subjects; however, evidence supporting the use of Modelflow to estimate SV in subjects completing stand or HUT tests remain scarce. Furthermore, because the blood pressure device is held extended at heart level during HUT tests, but allowed to rest at the side during stand tests, changes in the finger arterial pressure waveform resulting from arm positioning could alter modelflow estimated SV. The purpose of this project was to compare Doppler ultrasound and BeatScope estimations of SV to determine if BeatScope can be used during stand or HUT tests. Finger photoplethysmography was used to acquire arterial pressure waveforms corrected for hydrostatic finger-to-heart height using the Finometer (FM) and Portapres (PP) arterial pressure devices in 10 subjects (5 men and 5 women) during a stand test while simultaneous estimates of SV were collected using Doppler ultrasound. Measures were made after 5 minutes of supine rest and while subjects stood for 5 minutes. Next, SV estimates were reacquired while each arm was independently raised to heart level, a position similar to tilt testing. Supine SV estimates were not significantly different between all three devices (FM: 68+/-20, PP: 71+/-21, US: 73+/-21 ml/beat). Upon standing, the change in SV estimated by FM (-18+/-8 ml) was not different from PP (-21+/-12), but both were significantly

  8. Onboard utilization of ground control points for image correction. Volume 4: Correlation analysis software design

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The software utilized for image correction accuracy measurement is described. The correlation analysis program is written to allow the user various tools to analyze different correlation algorithms. The algorithms were tested using LANDSAT imagery in two different spectral bands. Three classification algorithms are implemented.

  9. Adventures in Holographic Dimer Models

    SciTech Connect

    Kachru, Shamit; Karch, Andreas; Yaida, Sho; /Stanford U., Phys. Dept.

    2011-08-12

    We abstract the essential features of holographic dimer models, and develop several new applications of these models. Firstly, semi-holographically coupling free band fermions to holographic dimers, we uncover novel phase transitions between conventional Fermi liquids and non-Fermi liquids, accompanied by a change in the structure of the Fermi surface. Secondly, we make dimer vibrations propagate through the whole crystal by way of double trace deformations, obtaining nontrivial band structure. In a simple toy model, the topology of the band structure experiences an interesting reorganization as we vary the strength of the double trace deformations. Finally, we develop tools that would allow one to build, in a bottom-up fashion, a holographic avatar of the Hubbard model.

  10. Holographic microscopy studies of emulsions

    NASA Technical Reports Server (NTRS)

    Witherow, W. K.

    1981-01-01

    A holographic microscopy system that records and observes the dynamic properties of separation of dispersed immiscible fluids is described. The holographic construction system and reconstruction system that were used to obtain particle size and distribution information from the holograms are discussed. The holographic microscopy system is used to observed the phase separating processes in immiscible fluids that were isothermally cooled into the two phase region. Nucleation, growth rates, coalescence, and particle motion are successfully demonstrated with this system. Thus a holographic particle sizing system with a resolution of 2 micrometers and a field of view of 100 cu cm was developed that provides the capability of testing the theories of separating immiscible fluids for particle number densities in the range of 10 to 10 to the 7th power particles.

  11. Creatine Kinase Activity Weakly Correlates to Volume Completed Following Upper Body Resistance Exercise

    ERIC Educational Resources Information Center

    Machado, Marco; Willardson, Jeffrey M.; Silva, Dailson P.; Frigulha, Italo C.; Koch, Alexander J.; Souza, Sergio C.

    2012-01-01

    In the current study, we examined the relationship between serum creatine kinase (CK) activity following upper body resistance exercise with a 1- or 3-min rest between sets. Twenty men performed two sessions, each consisting of four sets with a 10-repetition maximum load. The results demonstrated significantly greater volume for the 3-min…

  12. Photopolymerizable thiol-ene nanocomposite materials for holographic applications

    NASA Astrophysics Data System (ADS)

    Tomita, Yasuo; Hata, Eiji; Yasui, Satoru; Mitsube, Ken

    2011-06-01

    We describe an experimental investigation of the photopolymerization kinetics and volume holographic recording characteristics of silica nanoparticle-polymer nanocomposites using thiol-ene monomers capable of step-growth polymerization. We characterize the visible light curing kinetics of a thiol-ene monomer system consisting of secondary dithiol with high self-life stability and low odor and triene with rigid structure and high electron density by using real-time Fourier transform spectroscopy and photocalorimetry. In plane-wave volume holographic recording at a wavelength of 532 nm it is shown that while volume holograms recorded in the nanocomposites exhibit high transparency, their saturated refractive index modulation (Δnsat) and material sensitivity (S) are as large as 1x10-2 and 1615 cm/J, respectively. The polymerization shrinkage is reduced as low as 0.4% as a result of the late gelation in conversion. These values meet the acceptable values for holographic data storage media (i.e., 5x10-3, 500 cm/J and 0.5% for Δnsat, S and shrinkage, respectively). The improved thermal stability of volume holograms recorded in the nanocomposites is also confirmed experimentally.

  13. Mapping soil deformation around plant roots using in vivo 4D X-ray Computed Tomography and Digital Volume Correlation.

    PubMed

    Keyes, S D; Gillard, F; Soper, N; Mavrogordato, M N; Sinclair, I; Roose, T

    2016-06-14

    The mechanical impedance of soils inhibits the growth of plant roots, often being the most significant physical limitation to root system development. Non-invasive imaging techniques have recently been used to investigate the development of root system architecture over time, but the relationship with soil deformation is usually neglected. Correlative mapping approaches parameterised using 2D and 3D image data have recently gained prominence for quantifying physical deformation in composite materials including fibre-reinforced polymers and trabecular bone. Digital Image Correlation (DIC) and Digital Volume Correlation (DVC) are computational techniques which use the inherent material texture of surfaces and volumes, captured using imaging techniques, to map full-field deformation components in samples during physical loading. Here we develop an experimental assay and methodology for four-dimensional, in vivo X-ray Computed Tomography (XCT) and apply a Digital Volume Correlation (DVC) approach to the data to quantify deformation. The method is validated for a field-derived soil under conditions of uniaxial compression, and a calibration study is used to quantify thresholds of displacement and strain measurement. The validated and calibrated approach is then demonstrated for an in vivo test case in which an extending maize root in field-derived soil was imaged hourly using XCT over a growth period of 19h. This allowed full-field soil deformation data and 3D root tip dynamics to be quantified in parallel for the first time. This fusion of methods paves the way for comparative studies of contrasting soils and plant genotypes, improving our understanding of the fundamental mechanical processes which influence root system development. PMID:27155747

  14. Correlation between Peripheral Levels of Brain-Derived Neurotrophic Factor and Hippocampal Volume in Children and Adolescents with Bipolar Disorder.

    PubMed

    Lauxen Peruzzolo, Tatiana; Anes, Mauricio; Kohmann, Andre de Moura; Souza, Ana Claudia Mércio Loredo; Rodrigues, Ramiro Borges; Brun, Juliana Basso; Peters, Roberta; de Aguiar, Bianca Wollenhaupt; Kapczinski, Flavio; Tramontina, Silzá; Rohde, Luis Augusto Paim; Zeni, Cristian Patrick

    2015-01-01

    Pediatric bipolar disorder (PBD) is a serious mental disorder that affects the development and emotional growth of affected patients. The brain derived neurotrophic factor (BDNF) is recognized as one of the possible markers of the framework and its evolution. Abnormalities in BDNF signaling in the hippocampus could explain the cognitive decline seen in patients with TB. Our aim with this study was to evaluate possible changes in hippocampal volume in children and adolescents with BD and associate them to serum BDNF. Subjects included 30 patients aged seven to seventeen years from the ProCAB (Program for Children and Adolescents with Bipolar Disorder). We observed mean right and left hippocampal volumes of 41910.55 and 41747.96 mm(3), respectively. No statistically significant correlations between peripheral BDNF levels and hippocampal volumes were found. We believe that the lack of correlation observed in this study is due to the short time of evolution of BD in children and adolescents. Besides studies with larger sample sizes to confirm the present findings and longitudinal assessments, addressing brain development versus a control group and including drug-naive patients in different mood states may help clarify the role of BDNF in the brain changes consequent upon BD. PMID:26075097

  15. Holographic Recording Materials Development

    NASA Technical Reports Server (NTRS)

    Verber, C. M.; Schwerzel, R. E.; Perry, P. J.; Craig, R. A.

    1976-01-01

    Organic photorefractive materials were evaluated for application in a reversible holographic memory system. Representative indigo and thioindigo derivatives and several stilbene derivatives were studied as well as 15, 16-dialkyldihydropyrene derivatives the following goals were achieved: (1) the successful writing of phase holograms in a thioindigo/polymer gel system, (2) the successful writing and erasing of phase holograms in a variety of indigo/polymer gel and indigo/solid polymer systems, and (3) the identification of indigoid dyes and 15, 16-dialkyldihydropyrene derivatives as materials potentially suitable for utilization in an operational system. Photochemical studies of the stilbene, indigo, thioindigo, and dialkyldihydropyrene derivatives in solution and in a variety of polymer matrix materials were conducted with the goal of optimizing the photorefractive behavior of the chemical system as a whole. The spectroscopic properties required of optimal photorefractive materials were identified, and it was shown that both the indigoid dyes and the dialkyldihydropyrenes closely match the required properties.

  16. Holographic Vortex Coronagraph

    NASA Technical Reports Server (NTRS)

    Palacios, David

    2010-01-01

    A holographic vortex coronagraph (HVC) has been proposed as an improvement over conventional coronagraphs for use in high-contrast astronomical imaging for detecting planets, dust disks, and other broadband light scatterers in the vicinities of stars other than the Sun. Because such light scatterers are so faint relative to their parent stars, in order to be able to detect them, it is necessary to effect ultra-high-contrast (typically by a factor of the order of 1010) suppression of broadband light from the stars. Unfortunately, the performances of conventional coronagraphs are limited by low throughput, dispersion, and difficulty of satisfying challenging manufacturing requirements. The HVC concept offers the potential to overcome these limitations.

  17. Striped holographic superconductor

    SciTech Connect

    Flauger, Raphael; Pajer, Enrico; Papanikolaou, Stefanos

    2011-03-15

    We study inhomogeneous solutions of a 3+1-dimensional Einstein-Maxwell-scalar theory. Our results provide a holographic model of superconductivity in the presence of a charge density wave sourced by a modulated chemical potential. We find that below a critical temperature T{sub c} superconducting stripes develop. We show that they are thermodynamically favored over the normal state by computing the grand canonical potential. We investigate the dependence of T{sub c} on the modulation's wave vector, which characterizes the inhomogeneity. We find that it is qualitatively similar to that expected for a weakly coupled Bardeen-Cooper-Schrieer theory, but we point out a quantitative difference. Finally, we use our solutions to compute the conductivity along the direction of the stripes.

  18. Causality & holographic entanglement entropy

    NASA Astrophysics Data System (ADS)

    Headrick, Matthew; Hubeny, Veronika E.; Lawrence, Albion; Rangamani, Mukund

    2014-12-01

    We identify conditions for the entanglement entropy as a function of spatial region to be compatible with causality in an arbitrary relativistic quantum field theory. We then prove that the covariant holographic entanglement entropy prescription (which relates entanglement entropy of a given spatial region on the boundary to the area of a certain extremal surface in the bulk) obeys these conditions, as long as the bulk obeys the null energy condition. While necessary for the validity of the prescription, this consistency requirement is quite nontrivial from the bulk standpoint, and therefore provides important additional evidence for the prescription. In the process, we introduce a codimension-zero bulk region, named the entanglement wedge, naturally associated with the given boundary spatial region. We propose that the entanglement wedge is the most natural bulk region corresponding to the boundary reduced density matrix.

  19. Compact Holographic Data Storage

    NASA Technical Reports Server (NTRS)

    Chao, T. H.; Reyes, G. F.; Zhou, H.

    2001-01-01

    NASA's future missions would require massive high-speed onboard data storage capability to Space Science missions. For Space Science, such as the Europa Lander mission, the onboard data storage requirements would be focused on maximizing the spacecraft's ability to survive fault conditions (i.e., no loss in stored science data when spacecraft enters the 'safe mode') and autonomously recover from them during NASA's long-life and deep space missions. This would require the development of non-volatile memory. In order to survive in the stringent environment during space exploration missions, onboard memory requirements would also include: (1) survive a high radiation environment (1 Mrad), (2) operate effectively and efficiently for a very long time (10 years), and (3) sustain at least a billion write cycles. Therefore, memory technologies requirements of NASA's Earth Science and Space Science missions are large capacity, non-volatility, high-transfer rate, high radiation resistance, high storage density, and high power efficiency. JPL, under current sponsorship from NASA Space Science and Earth Science Programs, is developing a high-density, nonvolatile and rad-hard Compact Holographic Data Storage (CHDS) system to enable large-capacity, high-speed, low power consumption, and read/write of data in a space environment. The entire read/write operation will be controlled with electrooptic mechanism without any moving parts. This CHDS will consist of laser diodes, photorefractive crystal, spatial light modulator, photodetector array, and I/O electronic interface. In operation, pages of information would be recorded and retrieved with random access and high-speed. The nonvolatile, rad-hard characteristics of the holographic memory will provide a revolutionary memory technology meeting the high radiation challenge facing the Europa Lander mission. Additional information is contained in the original extended abstract.

  20. Sub-50nm extreme ultraviolet holographic imaging

    NASA Astrophysics Data System (ADS)

    Wachulak, P. W.; Marconi, M. C.; Bartels, R. A.; Menoni, C. S.; Rocca, J. J.

    2009-05-01

    Imaging tools for nanoscicence involving sub-100-nm scale objects have been dominated by atomic force microscopy (AFM), scanning tunneling microscopy (STM), and electron microscopy (SEM, TEM). These imaging techniques have contributed substantially to the development of nanoscience, providing a very powerful diagnostic tool capable of obtaining images with atomic resolution or as a subsidiary mechanism to arrange or modify surfaces also at the atomic scale [1,2]. However, some important problems have persisted traditional nanoscale imaging techniques. For example when scanning a nanometer size object that is not attached rigidly to a surface the interaction with the tip significantly perturbs the specimen degrading or eventually precluding the image acquisition. Electron microscopy often requires surface preparation, consisting of metallization of the sample to avoid surface charging. Additionally the metallization of the sample may alter its characteristics and also limits the resolution. In both cases, if the sample is large (millimeters in size) due to the limited field of view, the image obtained with these conventional methods is only representative of a very small portion of the object. Wavelength-limited holographic imaging using carbon nanotubes as the test object with a table-top extreme ultraviolet (EUV) laser operating at 46.9 nm will be discussed. The resolution achieved in this imaging is evaluated with a rigorous correlation image analysis and confirmed with the conventional knife-edge test. The nano-holography presented requires no optics or critical beam alignment; thus the hologram recording scheme is very simple and does not need special sample preparation. In holography, image contrast requires absorption to provide scattering by the illuminating beam. The EUV laser wavelength employed in this experiment (46.9nm) is advantageous because carbon based materials typically exhibit very small attenuation lengths, around 25 nm. The high absorption of

  1. Spatial resolution and measurement uncertainty of strains in bone and bone-cement interface using digital volume correlation.

    PubMed

    Zhu, Ming-Liang; Zhang, Qing-Hang; Lupton, Colin; Tong, Jie

    2016-04-01

    The measurement uncertainty of strains has been assessed in a bone analogue (sawbone), bovine trabecular bone and bone-cement interface specimens under zero load using the Digital Volume Correlation (DVC) method. The effects of sub-volume size, sample constraint and preload on the measured strain uncertainty have been examined. There is generally a trade-off between the measurement uncertainty and the spatial resolution. Suitable sub-volume sizes have been be selected based on a compromise between the measurement uncertainty and the spatial resolution of the cases considered. A ratio of sub-volume size to a microstructure characteristic (Tb.Sp) was introduced to reflect a suitable spatial resolution, and the measurement uncertainty associated was assessed. Specifically, ratios between 1.6 and 4 appear to give rise to standard deviations in the measured strains between 166 and 620 με in all the cases considered, which would seem to suffice for strain analysis in pre as well as post yield loading regimes. A microscale finite element (μFE) model was built from the CT images of the sawbone, and the results from the μFE model and a continuum FE model were compared with those from the DVC. The strain results were found to differ significantly between the two methods at tissue level, consistent in trend with the results found in human bones, indicating mainly a limitation of the current DVC method in mapping strains at this level. PMID:26741534

  2. Effects of excluded volume and correlated molecular orientations on Förster resonance energy transfer in liquid water

    SciTech Connect

    Yang, Mino

    2014-04-14

    Förster theory for the survival probability of excited chromophores is generalized to include the effects of excluded volume and orientation correlation in the molecular distribution. An analytical expression for survival probability was derived and written in terms of a few simple elementary functions. Because of the excluded volume, the survival probability exhibits exponential decay at early times and stretched exponential decay at later times. Experimental schemes to determine the size of the molecular excluded volume are suggested. With the present generalization of theory, we analyzed vibrational resonance energy transfer kinetics in neat water. Excluded volume effects prove to be important and slow down the kinetics at early times. The majority of intermolecular resonance energy transfer was found to occur with exponential kinetics, as opposed to the stretched exponential behavior predicted by Förster theory. Quantum yields of intra-molecular vibrational relaxation, intra-, and intermolecular energy transfer were calculated to be 0.413, 0.167, and 0.420, respectively.

  3. Holographic particle image velocimetry: analysis using a conjugate reconstruction geometry

    NASA Astrophysics Data System (ADS)

    Barnhart, D. H.; Halliwell, N. A.; Coupland, J. M.

    2000-10-01

    Holographic recording techniques have recently been studied as a means to extend two-component, planar particle image velocimetry (PIV) techniques for three-component, whole-field velocity measurements. In a similar manner to two-component PIV, three-component, holographic PIV (HPIV) uses correlation-based techniques to extract particle displacement fields from double-exposure holograms. Since a holographic image contains information concerning both the phase and the amplitude of the scattered field it is possible to correlate either the intensity or the complex amplitude. In previous work we have shown that optical methods to compute the autocorrelation of the complex amplitude are inherently more tolerant to aberrations introduced in the reconstruction process, Coupland, Halliwell, Proc. Roy. Soc. 453 (1960) (1997) 1066. In this paper we introduce a new method of holographic recording and reconstruction that allows a constant image shift to be introduced to the particle image displacement. The technique, which we call conjugate reconstruction, resolves directional ambiguity and extends the dynamic range of HPIV. The theory of this method is examined in detail and a relationship between the image and object displacement is derived. Experimental verification of the theory is presented.

  4. Phase transition of holographic entanglement entropy in massive gravity

    NASA Astrophysics Data System (ADS)

    Zeng, Xiao-Xiong; Zhang, Hongbao; Li, Li-Fang

    2016-05-01

    The phase structure of holographic entanglement entropy is studied in massive gravity for the quantum systems with finite and infinite volumes, which in the bulk is dual to calculating the minimal surface area for a black hole and black brane respectively. In the entanglement entropy-temperature plane, we find for both the black hole and black brane there is a Van der Waals-like phase transition as the case in thermal entropy-temperature plane. That is, there is a first order phase transition for the small charge and a second order phase transition at the critical charge. For the first order phase transition, the equal area law is checked and for the second order phase transition, the critical exponent of the heat capacity is obtained. All the results show that the phase structure of holographic entanglement entropy is the same as that of thermal entropy regardless of the volume of the spacetime on the boundary.

  5. Holographic optical elements: Fabrication and testing

    NASA Technical Reports Server (NTRS)

    Zech, R. G.; Shareck, M.; Ralston, L. M.

    1974-01-01

    The basic properties and use of holographic optical elements were investigated to design and construct wide-angle, Fourier-transform holographic optical systems for use in a Bragg-effect optical memory. The performance characteristics are described along with the construction of the holographic system.

  6. Holographic Information Storage and Retrieval. Final Report.

    ERIC Educational Resources Information Center

    Spencer, J. R.

    A four-month investigation was made of holographic information storage and retrieval. After an extensive review of the state of the art of various holographic systems, it was concluded that digital holographic storage techniques hold the greatest promise for commercial development, especially since they are particularly well suited to computer…

  7. Induction of morphological changes in death-induced cancer cells monitored by holographic microscopy.

    PubMed

    El-Schich, Zahra; Mölder, Anna; Tassidis, Helena; Härkönen, Pirkko; Falck Miniotis, Maria; Gjörloff Wingren, Anette

    2015-03-01

    We are using the label-free technique of holographic microscopy to analyze cellular parameters including cell number, confluence, cellular volume and area directly in the cell culture environment. We show that death-induced cells can be distinguished from untreated counterparts by the use of holographic microscopy, and we demonstrate its capability for cell death assessment. Morphological analysis of two representative cell lines (L929 and DU145) was performed in the culture flasks without any prior cell detachment. The two cell lines were treated with the anti-tumour agent etoposide for 1-3days. Measurements by holographic microscopy showed significant differences in average cell number, confluence, volume and area when comparing etoposide-treated with untreated cells. The cell volume of the treated cell lines was initially increased at early time-points. By time, cells decreased in volume, especially when treated with high doses of etoposide. In conclusion, we have shown that holographic microscopy allows label-free and completely non-invasive morphological measurements of cell growth, viability and death. Future applications could include real-time monitoring of these holographic microscopy parameters in cells in response to clinically relevant compounds. PMID:25637284

  8. Fourier holographic display for augmented reality using holographic optical element

    NASA Astrophysics Data System (ADS)

    Li, Gang; Lee, Dukho; Jeong, Youngmo; Lee, Byoungho

    2016-03-01

    A method for realizing a three-dimensional see-through augmented reality in Fourier holographic display is proposed. A holographic optical element (HOE) with the function of Fourier lens is adopted in the system. The Fourier hologram configuration causes the real scene located behind the lens to be distorted. In the proposed method, since the HOE is transparent and it functions as the lens just for Bragg matched condition, there is not any distortion when people observe the real scene through the lens HOE (LHOE). Furthermore, two optical characteristics of the recording material are measured for confirming the feasibility of using LHOE in the proposed see-through augmented reality holographic display. The results are verified experimentally.

  9. Indeterminacy of holographic quantum geometry

    NASA Astrophysics Data System (ADS)

    Hogan, Craig J.

    2008-10-01

    An effective theory based on wave optics is used to describe indeterminacy of position in holographic spacetime with a UV cutoff at the Planck scale. Wave functions describing spacetime positions are modeled as complex disturbances of quasimonochromatic radiation. It is shown that the product of standard deviations of two position wave functions in the plane of a holographic light sheet is equal to the product of their normal separation and the Planck length. For macroscopically separated positions the transverse uncertainty is much larger than the Planck length, and is predicted to be observable as a “holographic noise” in relative position with a distinctive shear spatial character, and an absolutely normalized frequency spectrum with no parameters once the fundamental wavelength is fixed from the theory of gravitational thermodynamics. The spectrum of holographic noise is estimated for the GEO600 interferometric gravitational-wave detector and is shown to approximately account for currently unexplained noise between about 300 and 1400 Hz. In a holographic world, this result directly and precisely measures the fundamental minimum interval of time.

  10. Holographic lithography for biomedical applications

    NASA Astrophysics Data System (ADS)

    Stankevicius, E.; Balciunas, E.; Malinauskas, M.; Raciukaitis, G.; Baltriukiene, D.; Bukelskiene, V.

    2012-06-01

    Fabrication of scaffolds for cell growth with appropriate mechanical characteristics is top-most important for successful creation of tissue. Due to ability of fast fabrication of periodic structures with a different period, the holographic lithography technique is a suitable tool for scaffolds fabrication. The scaffolds fabricated by holographic lithography can be used in various biomedical investigations such as the cellular adhesion, proliferation and viability. These investigations allow selection of the suitable material and geometry of scaffolds which can be used in creation of tissue. Scaffolds fabricated from di-acrylated poly(ethylene glycol) (PEG-DA-258) over a large area by holographic lithography technique are presented in this paper. The PEG-DA scaffolds fabricated by holographic lithography showed good cytocompatibility for rabbit myogenic stem cells. It was observed that adult rabbit muscle-derived myogenic stem cells grew onto PEG-DA scaffolds. They were attached to the pillars and formed cell-cell interactions. It demonstrates that the fabricated structures have potential to be an interconnection channel network for cell-to-cell interactions, flow transport of nutrients and metabolic waste as well as vascular capillary ingrowth. These results are encouraging for further development of holographic lithography by improving its efficiency for microstructuring three-dimensional scaffolds out of biodegradable hydrogels

  11. A Controlled Study on the Correlation between Tear Film Volume and Tear Film Stability in Diabetic Patients

    PubMed Central

    Khalil, Noha M.; El-Gendy, Heba A.

    2016-01-01

    Purpose. To assess the tear film quantity and correlate it with the quality and stability of the tear film in diabetics and compare them to age matched controls. Introduction. Diabetes affects tear film parameters in multiple ways. Poor metabolic control and neuropathy are postulated factors. To further understand how diabetes affects tear film parameters this study was conducted. Subjects and Methods. Tear meniscus height was measured by anterior segment OCT, along with tear thinning time, a subtype of noninvasive tear break-up time, and blinking rate per minute which were all recorded for 22 diabetic patients. Correlations between these tear film parameters were studied and then compared to 16 age matched controls. Results. A statistically significant difference was found in blinking rate between the diabetic and the control group (P = 0.002), with higher blinking rate among diabetics. All tear film parameters were negatively correlated with duration of diabetes. A positive correlation was found between tear film volume and stability. Conclusion. Diabetes affects the tear film in various ways. Diabetics should be examined for dry eye signs even in absence of symptoms which may be masked by associated neuropathy. Duration of diabetes has an impact on tear film status. PMID:27034823

  12. Free volume hole size of Cyanate ester resin/Epoxy resin interpenetrating networks and its correlations with physical properties

    NASA Astrophysics Data System (ADS)

    Zeng, Minfeng; Lu, Cuiyun; Wang, Baoyi; Qi, Chenze

    2010-09-01

    Cyanate ester (CE) resin was blended with epoxy resin (EP) at different mass ratios (CE/EP: 100/0, 90/10, 70/30, 50/50, 30/70, 10/90, and 0/100). The curing process of the blend system was characterized by Fourier transform infrared spectrometry (FTIR) and differential scanning calorimetry (DSC). Examination of the mechanical properties, thermal stability, and morphology of the blend systems showed that addition of epoxy resin resulted in improved toughness but a little sacrifice in thermal stability when compared with neat CE. The free volume size of the blend system determined by positron annihilation lifetime spectroscopy (PALS) decreased with the epoxy resin content, which is consistent with the chemical structure changes for the copolymerization between CE and EP. The crosslinking units of curing products (oxazoline, oxazolidinone, and polyether network) of the blends are all smaller in size than those of triazine ring structure from neat CE. Therefore, the free volume size of the blends decreases with increase of EP content. The correlations between the free volume properties and other physical properties (thermal stability and mechanical properties) have also been discussed.

  13. A Critical Examination of Relative Concentrations of Volume-correlated and Surface-correlated Submicron Globules of Pure Fe-0 in Lunar Soils

    NASA Technical Reports Server (NTRS)

    Basu, A.; McKay, D. S.; Wentworth, S. J.

    2003-01-01

    Impacts on lunar soils produce melt and vapor in an approximate proportion of 7:1. The melt scavenges soil grains of diverse size, quenches and forms agglutinates, thereby converting surface correlated components of soil grains as volume correlated components; simultaneously, parts of the vapor may condense or escape. Cumulative small impacts increase the maturity of the soils, increase the abundance of agglutinates, and increase the concentration of vapor condensated material. Since the discovery of vapor deposited crystalline Fe-0 in vugs of regolith breccias and the theoretical anticipation of amorphous vapor deposits of diverse composition coating lunar soils grains, empirical evidence is gathering in support of such deposits, now commonly called vapor deposited patina (VDP). In addition, submicron globules of Fe-0 are seen to be ubiquitous in VDP. The amorphous VDP lowers the albedo of lunar soils, affects magnetic properties of soils, changes the slopes of uv-vis-ir reflectance spectra, and potentially also alters the gamma and x-ray spectra of lunar soils, compromising compositional inferences from remote sensing.

  14. Cerebellar gray matter and lobular volumes correlate with core autism symptoms.

    PubMed

    D'Mello, Anila M; Crocetti, Deana; Mostofsky, Stewart H; Stoodley, Catherine J

    2015-01-01

    Neuroanatomical differences in the cerebellum are among the most consistent findings in autism spectrum disorder (ASD), but little is known about the relationship between cerebellar dysfunction and core ASD symptoms. The newly-emerging existence of cerebellar sensorimotor and cognitive subregions provides a new framework for interpreting the functional significance of cerebellar findings in ASD. Here we use two complementary analyses - whole-brain voxel-based morphometry (VBM) and the SUIT cerebellar atlas - to investigate cerebellar regional gray matter (GM) and volumetric lobular measurements in 35 children with ASD and 35 typically-developing (TD) children (mean age 10.4 ± 1.6 years; range 8-13 years). To examine the relationships between cerebellar structure and core ASD symptoms, correlations were calculated between scores on the Autism Diagnostic Observation Schedule (ADOS) and Autism Diagnostic Interview (ADI) and the VBM and volumetric data. Both VBM and the SUIT analyses revealed reduced GM in ASD children in cerebellar lobule VII (Crus I/II). The degree of regional and lobular gray matter reductions in different cerebellar subregions correlated with the severity of symptoms in social interaction, communication, and repetitive behaviors. Structural differences and behavioral correlations converged on right cerebellar Crus I/II, a region which shows structural and functional connectivity with fronto-parietal and default mode networks. These results emphasize the importance of the location within the cerebellum to the potential functional impact of structural differences in ASD, and suggest that GM differences in cerebellar right Crus I/II are associated with the core ASD profile. PMID:25844317

  15. The cosmic X-ray background-IRAS galaxy correlation and the local X-ray volume emissivity

    NASA Technical Reports Server (NTRS)

    Miyaji, Takamitsu; Lahav, Ofer; Jahoda, Keith; Boldt, Elihu

    1994-01-01

    We have cross-correlated the galaxies from the IRAS 2 Jy redshift survey sample and the 0.7 Jy projected sample with the all-sky cosmic X-ray background (CXB) map obtained from the High Energy Astronomy Observatory (HEAO) 1 A-2 experiment. We have detected a significant correlation signal between surface density of IRAS galaxies and the X-ray background intensity, with W(sub xg) = (mean value of ((delta I)(delta N)))/(mean value of I)(mean value of N)) of several times 10(exp -3). While this correlation signal has a significant implication for the contribution of the local universe to the hard (E greater than 2 keV) X-ray background, its interpretation is model-dependent. We have developed a formulation to model the cross-correlation between CXB surface brightness and galaxy counts. This includes the effects of source clustering and the X-ray-far-infrared luminosity correlation. Using an X-ray flux-limited sample of active galactic nuclei (AGNs), which has IRAS 60 micrometer measurements, we have estimated the contribution of the AGN component to the observed CXB-IRAS galaxy count correlations in order to see whether there is an excess component, i.e., contribution from low X-ray luminosity sources. We have applied both the analytical approach and Monte Carlo simulations for the estimations. Our estimate of the local X-ray volume emissivity in the 2-10 keV band is rho(sub x) approximately = (4.3 +/- 1.2) x 10(exp 38) h(sub 50) ergs/s/cu Mpc, consistent with the value expected from the luminosity function of AGNs alone. This sets a limit to the local volume emissivity from lower luminosity sources (e.g., star-forming galaxies, low-ionization nuclear emission-line regions (LINERs)) to rho(sub x) less than or approximately = 2 x 10(exp 38) h(sub 50) ergs/s/cu Mpc.

  16. Nonvolatile Rad-Hard Holographic Memory

    NASA Technical Reports Server (NTRS)

    Chao, Tien-Hsin; Zhou, Han-Ying; Reyes, George; Dragoi, Danut; Hanna, Jay

    2001-01-01

    We are investigating a nonvolatile radiation-hardened (rad-hard) holographic memory technology. Recently, a compact holographic data storage (CHDS) breadboard utilizing an innovative electro-optic scanner has been built and demonstrated for high-speed holographic data storage and retrieval. The successful integration of this holographic memory breadboard has paved the way for follow-on radiation resistance test of the photorefractive (PR) crystal, Fe:LiNbO3. We have also started the investigation of using two-photon PR crystals that are doubly doped with atoms of iron group (Ti, Cr, Mn, Cu) and of rare-earth group (Nd, Tb) for nonvolatile holographic recordings.

  17. Improvements of holographic data storage technology

    NASA Astrophysics Data System (ADS)

    Huang, Zhen; Liu, Guodong; Wang, Zhengzi; Cao, Guoqiang; Hou, Yibing

    2005-09-01

    Holographic data storage has many advantages, which makes it become one of the most hopeful next-generation data storage techniques. In the past, the struggles of holographic data storage have been frustrated for the absence of suitable system components and recording materials. Recently, the development of practical components for holographic systems, such as SLMs, CCDs and some newly recording materials, has rekindled interest in this technology. In this paper, we analyze the present situation of holographic data storage techniques and some latest improvements of key components and recording materials in relative companies or laboratories are summarized. At last, market outlook of holographic data storage products is discussed.

  18. Diabetes screening by telecentric digital holographic microscopy.

    PubMed

    Doblas, A; Roche, E; Ampudia-Blasco, F J; Martínez-Corral, M; Saavedra, G; Garcia-Sucerquia, J

    2016-03-01

    Diabetes is currently the world's fastest growing chronic disease and it is caused by deficient production of insulin by the endocrine pancreas or by abnormal insulin action in peripheral tissues. This results in persistent hyperglycaemia that over time may produce chronic diabetic complications. Determination of glycated haemoglobin level is currently the gold standard method to evaluate and control sustained hyperglycaemia in diabetic people. This measurement is currently made by high-performance liquid chromatography, which is a complex chemical process that requires the extraction of blood from the antecubital vein. To reduce the complexity of that measurement, we propose a fully-optical technique that is based in the fact that there are changes in the optical properties of erythrocytes due to the presence of glucose-derived adducts in the haemoglobin molecule. To evaluate these changes, we propose to perform quantitative phase maps of erythrocytes by using telecentric digital holographic microscopy. Our experiments show that telecentric digital holographic microscopy allows detecting, almost in real time and from a single drop of blood, significant differences between erythrocytes of diabetic patients and healthy patients. Besides, our phase measurements are well correlated with the values of glycated haemoglobin and the blood glucose values. PMID:26501512

  19. Digital holographic display

    NASA Astrophysics Data System (ADS)

    Lee, Cheok Peng; Chia, Yong Poo; Singh, Vijay Raj; Asundi, A.; Khoo, Xuan Jie; Tay, Kiat Long; Zhou, Junxiang

    2009-12-01

    This paper describes how a Digital Holographic Projector is designed and implemented to project two-dimension virtual images onto the volumetric display media. In this research, we focus on the method to create 3D models, diffractive algorithm and the display media. A 3D model is generated based on the 360° view with views at every 10° interval from a 3D perspective view software. The hologram interference fringes are re-producing from the Fraunhofer algorithm. In order to make more flexible and portable, a Compact Vision System is introduced to storage multiply interference fringes. At the same time, the fringes are sent out at 30 Hz frame by frame continually to the digital micro-mirror1. With the presence of Nd: YVO4 green laser and various optical components, the 3D 360° hologram images are dynamically reconstructed and projected onto the high speed rotating diffuser forming a 3D model at any viewing angle on the volumetric display media. Both volumetric display media, wet and dry methods are demonstrated to show their feasibility and convenience. Finally, the dry volumetric technique with vertical projection mounting is adopted and as the result shown that the speckle noise is significance reduced.

  20. Digital holographic display

    NASA Astrophysics Data System (ADS)

    Lee, Cheok Peng; Chia, Yong Poo; Singh, Vijay Raj; Asundi, A.; Khoo, Xuan Jie; Tay, Kiat Long; Zhou, Junxiang

    2010-03-01

    This paper describes how a Digital Holographic Projector is designed and implemented to project two-dimension virtual images onto the volumetric display media. In this research, we focus on the method to create 3D models, diffractive algorithm and the display media. A 3D model is generated based on the 360° view with views at every 10° interval from a 3D perspective view software. The hologram interference fringes are re-producing from the Fraunhofer algorithm. In order to make more flexible and portable, a Compact Vision System is introduced to storage multiply interference fringes. At the same time, the fringes are sent out at 30 Hz frame by frame continually to the digital micro-mirror1. With the presence of Nd: YVO4 green laser and various optical components, the 3D 360° hologram images are dynamically reconstructed and projected onto the high speed rotating diffuser forming a 3D model at any viewing angle on the volumetric display media. Both volumetric display media, wet and dry methods are demonstrated to show their feasibility and convenience. Finally, the dry volumetric technique with vertical projection mounting is adopted and as the result shown that the speckle noise is significance reduced.

  1. Scanning holographic lidar telescope

    NASA Technical Reports Server (NTRS)

    Schwemmer, Geary K.; Wilkerson, Thomas D.

    1993-01-01

    We have developed a unique telescope for lidar using a holographic optical element (HOE) as the primary optic. The HOE diffracts 532 nm laser backscatter making a 43 deg angle with a normal to its surface to a focus located 130 cm along the normal. The field of view scans a circle as the HOE rotates about the normal. The detector assembly and baffling remain stationary, compared to conventional scanning lidars in which the entire telescope and detector assembly require steering, or which use a large flat steerable mirror in front of the telescope to do the pointing. The spectral bandpass of our HOE is 50 nm (FWHM). Light within that bandpass is spectrally dispersed at 0.6 nm/mm in the focal plane. An aperture stop reduces the bandpass of light reaching the detector from one direction to 1 nm while simultaneously reducing the field of view to 1 mrad. Wavelengths outside the 50 nm spectral bandpass pass undiffracted through HOE to be absorbed by a black backing. Thus, the HOE combines three functions into one optic: the scanning mirror, the focusing mirror, and a narrowband filter.

  2. Constraining holographic inflation with WMAP

    SciTech Connect

    Easther, Richard; Flauger, Raphael; McFadden, Paul; Skenderis, Kostas E-mail: Raphael.Flauger@yale.edu E-mail: K.Skenderis@uva.nl

    2011-09-01

    In a class of recently proposed models, the early universe is strongly coupled and described holographically by a three-dimensional, weakly coupled, super-renormalizable quantum field theory. This scenario leads to a power spectrum of scalar perturbations that differs from the usual empirical ΛCDM form and the predictions of generic models of single field, slow roll inflation. This spectrum is characterized by two parameters: an amplitude, and a parameter g related to the coupling constant of the dual theory. We estimate these parameters, using WMAP and other astrophysical data. We compute Bayesian evidence for both the holographic model and standard ΛCDM and find that their difference is not significant, although ΛCDM provides a somewhat better fit to the data. However, it appears that Planck will permit a definitive test of this holographic scenario.

  3. Holographic characterization of protein aggregates

    NASA Astrophysics Data System (ADS)

    Wang, Chen; Zhong, Xiao; Ruffner, David; Stutt, Alexandra; Philips, Laura; Ward, Michael; Grier, David

    Holographic characterization directly measures the size distribution of subvisible protein aggregates in suspension and offers insights into their morphology. Based on holographic video microscopy, this analytical technique records and interprets holograms of individual aggregates in protein solutions as they flow down a microfluidic channel, without requiring labeling or other exceptional sample preparation. The hologram of an individual protein aggregate is analyzed in real time with the Lorenz-Mie theory of light scattering to measure that aggregate's size and optical properties. Detecting, counting and characterizing subvisible aggregates proceeds fast enough for time-resolved studies, and lends itself to tracking trends in protein aggregation arising from changing environmental factors. No other analytical technique provides such a wealth of particle-resolved characterization data in situ. Holographic characterization promises accelerated development of therapeutic protein formulations, improved process control during manufacturing, and streamlined quality assurance during storage and at the point of use. Mrsec and MRI program of the NSF, Spheryx Inc.

  4. Holographic films from carotenoid pigments

    NASA Astrophysics Data System (ADS)

    Toxqui-López, S.; Lecona-Sánchez, J. F.; Santacruz-Vázquez, C.; Olivares-Pérez, A.; Fuentes-Tapia, I.

    2014-02-01

    Carotenoids pigments presents in pineapple can be more than just natural dyes, which is one of the applications that now at day gives the chemical industry. In this research shown that can be used in implementing of holographic recording Films. Therefore we describe the technique how to obtain this kind of pigments trough spay drying of natural pineapple juice, which are then dissolved with water in a proportion of 0.1g to 1mL. The obtained sample is poured into glass substrates using the gravity method, after a drying of 24 hours in laboratory normal conditions the films are ready. The films are characterized by recording transmission holographic gratings (LSR 445 NL 445 nm) and measuring the diffraction efficiency holographic parameter. This recording material has good diffraction efficiency and environmental stability.

  5. Single port access holographic particle image velocimetry

    SciTech Connect

    Woodruff, S.D.; Richards, G.A.; Cha, D.J.

    1995-07-01

    An optical system, which requires only a single optical window mounted on a test volume, is proposed for holographic particle image velocimetry (HPIV). The optical system is a derivative of the double-exposure, double-reference-beam, off-axis HPIV system, but the innovative idea behind the system is to use back scattered light from the particles as the object wave. A 45{degree} beam splitter inserted in front of the window serves to admit the illuminating beam and extract the back scattered light. This concept can be of great engineering interest because optical access is often limited to one window in practical devices. The preliminary results of the technique appear quite promising, with current studies aimed at defining the optical resolution capabilities.

  6. Holographic Photolysis for Multiple Cell Stimulation in Mouse Hippocampal Slices

    PubMed Central

    Papagiakoumou, Eirini; Ventalon, Cathie; Angulo, María Cecilia; Emiliani, Valentina

    2010-01-01

    Background Advanced light microscopy offers sensitive and non-invasive means to image neural activity and to control signaling with photolysable molecules and, recently, light-gated channels. These approaches require precise and yet flexible light excitation patterns. For synchronous stimulation of subsets of cells, they also require large excitation areas with millisecond and micrometric resolution. We have recently developed a new method for such optical control using a phase holographic modulation of optical wave-fronts, which minimizes power loss, enables rapid switching between excitation patterns, and allows a true 3D sculpting of the excitation volumes. In previous studies we have used holographic photololysis to control glutamate uncaging on single neuronal cells. Here, we extend the use of holographic photolysis for the excitation of multiple neurons and of glial cells. Methods/Principal Findings The system combines a liquid crystal device for holographic patterned photostimulation, high-resolution optical imaging, the HiLo microscopy, to define the stimulated regions and a conventional Ca2+ imaging system to detect neural activity. By means of electrophysiological recordings and calcium imaging in acute hippocampal slices, we show that the use of excitation patterns precisely tailored to the shape of multiple neuronal somata represents a very efficient way for the simultaneous excitation of a group of neurons. In addition, we demonstrate that fast shaped illumination patterns also induce reliable responses in single glial cells. Conclusions/Significance We show that the main advantage of holographic illumination is that it allows for an efficient excitation of multiple cells with a spatiotemporal resolution unachievable with other existing approaches. Although this paper focuses on the photoactivation of caged molecules, our approach will surely prove very efficient for other probes, such as light-gated channels, genetically encoded photoactivatable

  7. Tumor Volume Reduction Rate Measured by Magnetic Resonance Volumetry Correlated With Pathologic Tumor Response of Preoperative Chemoradiotherapy for Rectal Cancer

    SciTech Connect

    Yeo, Seung-Gu; Kim, Dae Yong; Kim, Tae Hyun; Jung, Kyung Hae; Hong, Yong Sang; Chang, Hee Jin; Park, Ji Won; Lim, Seok-Byung; Choi, Hyo Seong; Jeong, Seung-Yong

    2010-09-01

    Purpose: To determine whether the tumor volume reduction rate (TVRR) measured using three-dimensional region-of-interest magnetic resonance volumetry correlates with the pathologic tumor response after preoperative chemoradiotherapy (CRT) for locally advanced rectal cancer. Methods and Materials: The study included 405 patients with locally advanced rectal cancer (cT3-T4) who had undergone preoperative CRT and radical proctectomy. The tumor volume was measured using three-dimensional region-of-interest magnetic resonance volumetry before and after CRT but before surgery. We analyzed the correlation between the TVRR and the pathologic tumor response in terms of downstaging and tumor regression grade (TRG). Downstaging was defined as ypStage 0-I (ypT0-T2N0M0), and the TRG proposed by Dworak et al. was used. Results: The mean TVRR was 65.0% {+-} 22.3%. Downstaging and complete regression occurred in 167 (41.2%) and 58 (14.3%) patients, respectively. The TVRRs according to ypT classification (ypT0-T2 vs. ypT3-T4), ypN classification (ypN0 vs. ypN1-N2), downstaging (ypStage 0-I vs. ypStage II-III), good regression (TRG 3-4 vs. TRG 1-2), and complete regression (TRG 4 vs. TRG 1-3) were all significantly different (p <.05). When the TVRR was categorized into three groups (<60%, 60-80%, and >80%), the rates of ypT0-T2, ypN0, downstaging, and good regression were all significantly greater for patients with a TVRR of {>=}60%, as was the complete regression rate for patients with a TVRR >80% (p <.05). Conclusion: The TVRR measured using three-dimensional region-of-interest magnetic resonance volumetry correlated significantly with the pathologic tumor response in terms of downstaging and TRG after preoperative CRT for locally advanced rectal cancer.

  8. Acoustic Treatment Design Scaling Methods. Volume 5; Analytical and Experimental Data Correlation

    NASA Technical Reports Server (NTRS)

    Chien, W. E.; Kraft, R. E.; Syed, A. A.

    1999-01-01

    The primary purpose of the study presented in this volume is to present the results and data analysis of in-duct transmission loss measurements. Transmission loss testing was performed on full-scale, 1/2-scale, and 115-scale treatment panel samples. The objective of the study was to compare predicted and measured transmission loss for full-scale and subscale panels in an attempt to evaluate the variations in suppression between full- and subscale panels which were ostensibly of equivalent design. Generally, the results indicated an unsatisfactory agreement between measurement and prediction, even for full-scale. This was attributable to difficulties encountered in obtaining sufficiently accurate test results, even with extraordinary care in calibrating the instrumentation and performing the test. Test difficulties precluded the ability to make measurements at frequencies high enough to be representative of subscale liners. It is concluded that transmission loss measurements without ducts and data acquisition facilities specifically designed to operate with the precision and complexity required for high subscale frequency ranges are inadequate for evaluation of subscale treatment effects.

  9. Application of color digital holographic microscopy for analysis of stained tissue sections

    NASA Astrophysics Data System (ADS)

    Mo, Xiaoli; Kemper, Björn; Langehanenberg, Patrik; Vollmer, Angelika; Xie, Jinghui; von Bally, Gert

    2009-07-01

    The analysis of stained tissue sections represents an important tool in medical diagnostics. Color digital holographic microscopy offers subsequent multi-focus true color imaging with simultaneous quantitative phase contrast analysis. Investigations on digital recording and numerical reconstructions of color digital holographic images have been performed by applying a transmission microscope experimental setup in holographic off-axis geometry. Three monochromatic digital holograms with different wavelengths in red, green and blue spectral range are recorded. After digital holographic refocusing and compensation for aberrations of the microscope imaging system by digital image correlation the numerically reconstructed amplitude distributions are combined into color images. The applicability of the method is demonstrated by results obtained from stained intestine tissue sections.

  10. Glueball decay in holographic QCD

    SciTech Connect

    Hashimoto, Koji; Tan, C.-I; Terashima, Seiji

    2008-04-15

    Using holographic QCD based on D4-branes and D8-anti-D8-branes, we have computed couplings of glueballs to light mesons. We describe glueball decay by explicitly calculating its decay widths and branching ratios. Interestingly, while glueballs remain less well understood both theoretically and experimentally, our results are found to be consistent with the experimental data for the scalar glueball candidate f{sub 0}(1500). More generally, holographic QCD predicts that decay of any glueball to 4{pi}{sup 0} is suppressed, and that mixing of the lightest glueball with qq mesons is small.

  11. Invisible engineering of holographic illusion

    NASA Astrophysics Data System (ADS)

    Richardson, Martin J.

    1993-03-01

    Recent developments in production techniques of pulsed holograms and holographic stereograms have ameliorated to provide high quality three dimensional illusions that echo the apparently innate need of society to replicate itself through artificial means. A commercial platform has been found for these archetypical illusions through the mass production and distribution of embossed stereograms that depict popular celebrities from the music industry. As pulse recordings of the rich and famous become better known, and as former presidents queue to join the holographic hall of fame, the author asks `is it documentation or entertainment that is shaping the future of holography?'

  12. Hadron physics in holographic QCD

    NASA Astrophysics Data System (ADS)

    Santra, A. B.; Lombardo, U.; Bonanno, A.

    2012-07-01

    Hadron physics deals with the study of strongly interacting subatomic particles such as neutrons, protons, pions and others, collectively known as baryons and mesons. Physics of strong interaction is difficult. There are several approaches to understand it. However, in the recent years, an approach called, holographic QCD, based on string theory (or gauge-gravity duality) is becoming popular providing an alternative description of strong interaction physics. In this article, we aim to discuss development of strong interaction physics through QCD and string theory, leading to holographic QCD.

  13. Precision holographic optical elements in Bayfol HX photopolymer

    NASA Astrophysics Data System (ADS)

    Bruder, Friedrich-Karl; Bang, Hyungseok; Fäcke, Thomas; Hagen, Rainer; Hönel, Dennis; Orselli, Enrico; Rewitz, Christian; Rölle, Thomas; Vukicevic, Dalibor; Walze, Günther

    2016-03-01

    The versatility of Volume Holographic Optical Elements (vHOE) is high, especially because of their tunable angular and spectral Bragg selectivity. Those unique lightweight, thin and flat optical elements are enabled by the new instant developing photopolymer film Bayfol® HX technology, which allows to mass produce cost effective diffractive optics due to its simplified and robust holographic recording process. From a pure scientific point of view volume holography is well established. In practice though, commercially available optical design software is not adapted to handle the specific characteristics of photopolymer diffractive optical elements and their recording. To achieve high quality vHOE precision optics, the recording setup needs to accommodate several aspects that will be covered in this paper. We report on means how to deal with photopolymer shrinkage and average refractive index changes of the recording media. An important part in diffractive optics design is the compensation of different conditions between the holographic recording setup and in a final product containing the vHOE. Usually substrates might need to be changed (in material, in refractive index) as well the illumination sources are using incoherent light having angular and spectral emission profiles with finite bandwidth. Recently special in- and out-coupling vHOEs are becoming attractive e.g. in near eye displays and in compact lighting devices. We will report on design considerations and adjustments to the recording condition for a specific in-coupling vHOE and demonstrate the effects of pre-compensation on this example.

  14. LCTV Holographic Imaging

    NASA Technical Reports Server (NTRS)

    Knopp, Jerome

    1996-01-01

    Astronauts are required to interface with complex systems that require sophisticated displays to communicate effectively. Lightweight, head-mounted real-time displays that present holographic images for comfortable viewing may be the ideal solution. We describe an implementation of a liquid crystal television (LCTV) as a spatial light modulator (SLM) for the display of holograms. The implementation required the solution of a complex set of problems. These include field calculations, determination of the LCTV-SLM complex transmittance characteristics and a precise knowledge of the signal mapping between the LCTV and frame grabbing board that controls it. Realizing the hologram is further complicated by the coupling that occurs between the phase and amplitude in the LCTV transmittance. A single drive signal (a gray level signal from a framegrabber) determines both amplitude and phase. Since they are not independently controllable (as is true in the ideal SLM) one must deal with the problem of optimizing (in some sense) the hologram based on this constraint. Solutions for the above problems have been found. An algorithm has been for field calculations that uses an efficient outer product formulation. Juday's MEDOF 7 (Minimum Euclidean Distance Optimal Filter) algorithm used for originally for filter calculations has been successfully adapted to handle metrics appropriate for holography. This has solved the problem of optimizing the hologram to the constraints imposed by coupling. Two laboratory methods have been developed for determining an accurate mapping of framegrabber pixels to LCTV pixels. A friendly software system has been developed that integrates the hologram calculation and realization process using a simple set of instructions. The computer code and all the laboratory measurement techniques determining SLM parameters have been proven with the production of a high quality test image.

  15. Design of a multiplexing grating for color holographic waveguide

    NASA Astrophysics Data System (ADS)

    Guo, Jingjing; Tu, Yan; Yang, Lanlan; Wang, Lili; Wang, Baoping

    2015-12-01

    Volume holographic gratings have been used in waveguide displays to implement full-color three-dimensional imaging. Among these, multiplexing gratings are advanced in low energy losses and simple manufacture technologies when used as couplers of color hologram waveguides. A multiplexing holographic grating is designed to realize a uniform red, green, and blue diffraction efficiency and eliminate stray light to the largest extent. Results indicate that the red, green, and blue light incident normal to the grating could be successfully in-coupled into the planar waveguide for total internal reflection with high peak diffraction efficiency, similar energy output, and little stray light. We also analyze the effect of the technical tolerance, including gating thickness, index modulation, grating period, slanted angle, and incident angle. This analysis could help to minimize the optical system and improve the color image quality of waveguide displays.

  16. Polymer electrolyte membranes with exceptional conductivity anisotropy via holographic polymerization

    NASA Astrophysics Data System (ADS)

    Smith, Derrick M.; Cheng, Shan; Wang, Wenda; Bunning, Timothy J.; Li, Christopher Y.

    2014-12-01

    Polymer electrolyte membranes using an ionic liquid as electrolyte with an ionic conductivity anisotropy of ∼5000 have been fabricated using a holographic polymerization nanomanufacturing technique. The resultant structure is referred to as holographic polymer electrolyte membranes (hPEMs), which are comprised of alternating nanolayers of a room temperature ionic liquid and crosslinked polymer resin, confirmed under TEM imaging. These hPEMs also show no reduction in room temperature conductivity with respect to the loaded ionic liquid when characterized in the plane of ionic liquid nanolayers. At elevated temperatures with the optimal electrolyte volume loading, calculation shows that the free ion concentration is higher than the pure ionic liquid, suggesting that the photopolymer dual-functionalizes as a loadbearing scaffold and an ion-complexing agent, allowing for more ions to participate in charge transfer. These hPEMs provide a promising solution to decoupling mechanical enhancement and ion transport in polymer electrolyte membranes.

  17. Quantifying uncertainty in soot volume fraction estimates using Bayesian inference of auto-correlated laser-induced incandescence measurements

    NASA Astrophysics Data System (ADS)

    Hadwin, Paul J.; Sipkens, T. A.; Thomson, K. A.; Liu, F.; Daun, K. J.

    2016-01-01

    Auto-correlated laser-induced incandescence (AC-LII) infers the soot volume fraction (SVF) of soot particles by comparing the spectral incandescence from laser-energized particles to the pyrometrically inferred peak soot temperature. This calculation requires detailed knowledge of model parameters such as the absorption function of soot, which may vary with combustion chemistry, soot age, and the internal structure of the soot. This work presents a Bayesian methodology to quantify such uncertainties. This technique treats the additional "nuisance" model parameters, including the soot absorption function, as stochastic variables and incorporates the current state of knowledge of these parameters into the inference process through maximum entropy priors. While standard AC-LII analysis provides a point estimate of the SVF, Bayesian techniques infer the posterior probability density, which will allow scientists and engineers to better assess the reliability of AC-LII inferred SVFs in the context of environmental regulations and competing diagnostics.

  18. Determining the Total Volume of the 2.05 Ga Bushveld Magmatic Event: Correlation of the Molopo Farms Complex, Botswana

    NASA Astrophysics Data System (ADS)

    Escobar, E.; Gates, M.; Pitcavage, E.; Bybee, G. M.; Feineman, M. D.

    2015-12-01

    The Bushveld Igneous Complex (BIC) in South Africa, erupted 2.05 billion years ago, is the world's largest layered intrusion in the range of 710-1060 x 103 km3 conservatively. However, the total volume of the magmatic event that produced the BIC remains poorly known. Several other intrusions occurred approximately contemporaneously with the BIC, but a clear relationship between these multiple intrusions is yet to be determined. The Molopo Farms Complex (MFC) is a layered igneous complex of similar age 2.044 Ga ­± 24 Ma located in Botswana, 200km west of the far western limb of the BIC, with a total volume of 1300 km2. Using trace element analysis, this study makes an attempt to find a correlation between the magma that emplaced the Molopo Farms Complex with the Bushveld Igneous Complex. The MFC is related to the BIC and is located under approximately 200m of Kalahari sands, which prevents any direct sampling or observation. Unlike the BIC, the MFC is poorly studied creating a lack of information for the complex. Drill core samples from the MFC were analyzed to determine the trace element composition using an inductively coupled plasma mass spectrometer (ICP-MS). Using previously reported values for the BIC; a comparison can be made on both complexes to find possible correlations. The comparison of trace element schematics in the MFC and the BIC suggest that both complexes are derived from the same parental magma, often referred to as the "B1" magma. These comparisons allow for an assumption that the initial parental magma of the BIC may have also emplaced the MFC.

  19. Ion-ion correlation, solvent excluded volume and pH effects on physicochemical properties of spherical oxide nanoparticles.

    PubMed

    Ovanesyan, Zaven; Aljzmi, Amal; Almusaynid, Manal; Khan, Asrar; Valderrama, Esteban; Nash, Kelly L; Marucho, Marcelo

    2016-01-15

    One major source of complexity in the implementation of nanoparticles in aqueous electrolytes arises from the strong influence that biological environments has on their physicochemical properties. A key parameter for understanding the molecular mechanisms governing the physicochemical properties of nanoparticles is the formation of the surface charge density. In this article, we present an efficient and accurate approach that combines a recently introduced classical solvation density functional theory for spherical electrical double layers with a surface complexation model to account for ion-ion correlation and excluded volume effects on the surface titration of spherical nanoparticles. We apply the proposed computational approach to account for the charge-regulated mechanisms on the surface chemistry of spherical silica (SiO2) nanoparticles. We analyze the effects of the nanoparticle size, as well as pH level and electrolyte concentration of the aqueous solution on the nanoparticle's surface charge density and Zeta potential. We validate our predictions for 580Å and 200Å nanoparticles immersed in acid, neutral and alkaline mono-valent aqueous electrolyte solutions against experimental data. Our results on mono-valent electrolyte show that the excluded volume and ion-ion correlations contribute significantly to the surface charge density and Zeta potential of the nanoparticle at high electrolyte concentration and pH levels, where the solvent crowding effects and electrostatic screening have shown a profound influence on the protonation/deprotonation reactions at the liquid/solute interface. The success of this approach in describing physicochemical properties of silica nanoparticles supports its broader application to study other spherical metal oxide nanoparticles. PMID:26476201

  20. Holographic analyzer and image scanner

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The characteristics, components, and operating procedures are described for a holographic camera real images projection displayer and scanner unit having the capability to upgrade to multiple types of automated raster scan patterns. Schematics of the optical components are included with a diagram of the electric circuit connections.

  1. Music holographic physiotherapy by laser

    NASA Astrophysics Data System (ADS)

    Liao, Changhuan

    1996-09-01

    Based on the relationship between music and nature, the paper compares laser and light with music sound on the principles of synergetics, describes music physically and objectively, and proposes a music holographic therapy by laser. Maybe it will have certain effects on mechanism study and clinical practice of the music therapy.

  2. Holographic nondestructive testing of laminates

    NASA Technical Reports Server (NTRS)

    Stuckenberg, F. H.

    1973-01-01

    Very small differences in laminate thickness result in interference fringes in holograph image. These indicate presence of unbonded area. Theoretical knowledge of membrane deflection may be used in conjunction with reduced number of pretest experiments to determine number of optical fringes that should appear for given laminate.

  3. Holographic diagnostics of biological microparticles

    NASA Astrophysics Data System (ADS)

    Dyomin, Victor V.; Sokolov, Vladimir V.

    1996-05-01

    Problem of studies of biological microojects is actual one for ecology, medicine, biology. Holographic techniques are useful to solve the problem. The above microojects are transparent or semitransparent ones in a visible light rather often. The case of an optically soft particle, (that is of a particle whose substance has the refractive index close to that of the surrounding medium) is quite probable in biological water suspensions. Some peculiarities of holographing optically soft microparticles are analyzed in this paper. We propose a technique to calculate a light intensity distribution in the plane of a hologram and in the plane of a holographic image of a particle of an arbitrary shape at an arbitrary distance from the latter plane. The efficiency of the approach proposed is demonstrated by calculational results obtained analytically for some simple cases. In a more complicated cases the technique can make a basis for numerical computations. The method of determining of refractive index of transparent and semitransparent microparticles is proposed. We also present in this paper some experimental results on holographic detection of the water drops and such optically soft particles as ovums of helmints in human jaundice.

  4. Direct observation of spatiotemporal dependence of anomalous diffusion in inhomogeneous fluid by sampling-volume-controlled fluorescence correlation spectroscopy

    NASA Astrophysics Data System (ADS)

    Masuda, Akiko; Ushida, Kiminori; Okamoto, Takayuki

    2005-12-01

    The direct observation of a spatiotemporal behavior of anomalous diffusion in aqueous polymer [hyaluronan (HA)] solution was achieved by fluorescence correlation spectroscopy (FCS) using a modified instrument, enabling continuous change of the confocal volume of a microscope, namely, sampling-volume-controlled (SVC) FCS (SVC-FCS). Since HA chains form a mesh structure with a pore size of about 10-40nm , the observed diffusion coefficient (Dobs) is markedly dependent on the diffusion distance (L) . By SVC-FCS, the curve of the distance dependence of diffusion coefficient was directly obtained as a continuous profile in L=245-600nm showing evidence of anomalous diffusion. On plotting Dobs against either of the sampling time (τobs) or the diffusion distance (L) , Dobs turnover was observed near the anomalous diffusion area. The appearance of this turnover is attributed to the nonuniform mesh structure that can be observed only by a fast observation and that should be dynamically averaged by polymer motions with large τobs . This behavior is similar to that revealed in glass, colloidal systems, and gel solutions using dynamic light scattering, neutron scattering, and other techniques.

  5. Universal properties of cold holographic matter

    NASA Astrophysics Data System (ADS)

    Jokela, Niko; Ramallo, Alfonso V.

    2015-07-01

    We study the collective excitations of holographic quantum liquids formed in the low energy theory living at the intersection of two sets of D-branes. The corresponding field theory dual is a supersymmetric Yang-Mills theory with massless matter hypermultiplets in the fundamental representation of the gauge group which generically live on a defect of the unflavored theory. Working in the quenched (probe) approximation, we focus on determining the universal properties of these systems. We analyze their thermodynamics, the speed of first sound, the diffusion constant, and the speed of zero sound. We study the influence of temperature, chemical potential, and magnetic field on these quantities, as well as on the corresponding collisionless/hydrodynamic crossover. We also generalize the alternative quantization for all conformally AdS4 cases and study the anyonic correlators.

  6. Measuring local volume fraction, long-wavelength correlations, and fractionation in a phase-separating polydisperse fluid

    SciTech Connect

    Williamson, J. J.; Evans, R. M. L.

    2014-10-28

    We dynamically simulate fractionation (partitioning of particle species) during spinodal gas-liquid separation of a size-polydisperse colloid, using polydispersity up to ∼40% and a skewed parent size distribution. We introduce a novel coarse-grained Voronoi method to minimise size bias in measuring local volume fraction, along with a variety of spatial correlation functions which detect fractionation without requiring a clear distinction between the phases. These can be applied whether or not a system is phase separated, to determine structural correlations in particle size, and generalise easily to other kinds of polydispersity (charge, shape, etc.). We measure fractionation in both mean size and polydispersity between the phases, its direction differing between model interaction potentials which are identical in the monodisperse case. These qualitative features are predicted by a perturbative theory requiring only a monodisperse reference as input. The results show that intricate fractionation takes place almost from the start of phase separation, so can play a role even in nonequilibrium arrested states. The methods for characterisation of inhomogeneous polydisperse systems could in principle be applied to experiment as well as modelling.

  7. Holographic investigations of azobenzene-containing low-molecular-weight compounds in pure materials and binary blends with polystyrene.

    PubMed

    Audorff, Hubert; Walker, Roland; Kador, Lothar; Schmidt, Hans-Werner

    2011-11-01

    This paper reports on the synthesis and the thermal and optical properties of photochromic low-molecular-weight compounds, especially with respect to the formation of holographic volume gratings in the pure materials and in binary blends with polystyrene. Its aim is to provide a basic understanding of the holographic response with regard to the molecular structure, and thus to show a way to obtain suitable rewritable materials with high sensitivity for holographic data storage. The photoactive low-molecular-weight compounds consist of a central core with three or four azobenzene-based arms attached through esterification. Four different cores were investigated that influence the glass transition temperature and the glass-forming properties. Additional structural variations were introduced by the polar terminal substituent at the azobenzene chromophore to fine-tune the optical properties and the holographic response. Films of the neat compounds were investigated in holographic experiments, especially with regard to the material sensitivity. In binary blends of the low-molecular-weight compounds with polystyrene, the influence of a polymer matrix on the behavior in holographic experiments was studied. The most promising material combination was also investigated at elevated temperatures, at which the holographic recording sensitivity is even higher. PMID:21956207

  8. Holographic complexity in gauge/string superconductors

    NASA Astrophysics Data System (ADS)

    Momeni, Davood; Mansoori, Seyed Ali Hosseini; Myrzakulov, Ratbay

    2016-05-01

    Following a methodology similar to [1], we derive a holographic complexity for two dimensional holographic superconductors (gauge/string superconductors) with backreactions. Applying a perturbation method proposed by Kanno in Ref. [2], we study behaviors of the complexity for a dual quantum system near critical points. We show that when a system moves from the normal phase (T >Tc) to the superconductor phase (T holographic complexity will be divergent.

  9. Compact holographic printer using RGB waveguide holographic optical elements

    NASA Astrophysics Data System (ADS)

    Pyun, Kyungsuk P.; Choi, Chilsung; Morozov, Alexander V.; Kim, Sunil; An, Jungkwuen

    2013-03-01

    We propose compact holographic printer using RGB waveguide hologram while reducing overall device size and quantity of elements with integrated functionality of each optical element. For glasses-free 3D experience anywhere anytime, it is critical to make holography device that can be as compact and integrated as possible. Compared to the conventional optics-based structure, our RGB WGH-based one reduces the overall size by 20 times, the number of components by 10 times, and improves the optical efficiency by 3 times, with comparable holographic quality to the conventional optics-based approaches. Proposed research can be useful for both general consumers and professionals like 3D photography and medical 3D image printing applications.

  10. Label-free cytotoxicity screening assay by digital holographic microscopy.

    PubMed

    Kühn, Jonas; Shaffer, Etienne; Mena, Julien; Breton, Billy; Parent, Jérôme; Rappaz, Benjamin; Chambon, Marc; Emery, Yves; Magistretti, Pierre; Depeursinge, Christian; Marquet, Pierre; Turcatti, Gerardo

    2013-03-01

    We introduce a label-free technology based on digital holographic microscopy (DHM) with applicability for screening by imaging, and we demonstrate its capability for cytotoxicity assessment using mammalian living cells. For this first high content screening compatible application, we automatized a digital holographic microscope for image acquisition of cells using commercially available 96-well plates. Data generated through both label-free DHM imaging and fluorescence-based methods were in good agreement for cell viability identification and a Z'-factor close to 0.9 was determined, validating the robustness of DHM assay for phenotypic screening. Further, an excellent correlation was obtained between experimental cytotoxicity dose-response curves and known IC50 values for different toxic compounds. For comparable results, DHM has the major advantages of being label free and close to an order of magnitude faster than automated standard fluorescence microscopy. PMID:23062077

  11. Dynamics of holographic entanglement entropy following a local quench

    NASA Astrophysics Data System (ADS)

    Rangamani, Mukund; Rozali, Moshe; Vincart-Emard, Alexandre

    2016-04-01

    We discuss the behaviour of holographic entanglement entropy following a local quench in 2+1 dimensional strongly coupled CFTs. The entanglement generated by the quench propagates along an emergent light-cone, reminiscent of the Lieb-Robinson light-cone propagation of correlations in non-relativistic systems. We find the speed of propagation is bounded from below by the entanglement tsunami velocity obtained earlier for global quenches in holographic systems, and from above by the speed of light. The former is realized for sufficiently broad quenches, while the latter pertains for well localized quenches. The non-universal behavior in the intermediate regime appears to stem from finite-size effects. We also note that the entanglement entropy of subsystems reverts to the equilibrium value exponentially fast, in contrast to a much slower equilibration seen in certain spin models.

  12. Holographic projection with higher image quality.

    PubMed

    Qu, Weidong; Gu, Huarong; Tan, Qiaofeng

    2016-08-22

    The spatial resolution limited by the size of the spatial light modulator (SLM) in the holographic projection can hardly be increased, and speckle noise always appears to induce the degradation of image quality. In this paper, the holographic projection with higher image quality is presented. The spatial resolution of the reconstructed image is 2 times of that of the existing holographic projection, and speckles are suppressed well at the same time. Finally, the effectiveness of the holographic projection is verified in experiments. PMID:27557197

  13. Investigation of uses of holographic optical elements

    NASA Technical Reports Server (NTRS)

    Zech, R. G.; Latta, J. N.

    1973-01-01

    The data represent a thorough study of the aberrations and imaging properties of holographic optical elements. Principle studies include (1) the indepth experimental investigation of single holographic optical elements, (2) the verification of the accuracy of the theoretical computer-based description of hologram behavior, (3) the computer-generation of interferograms that are characteristic of a prescribed aberrated imaging condition, (4) the experimental verification of wavelength optimization, (5) the experimental determination of the space bandwidth product of single holographic optical elements as a function of bending and field angle, and (6) the first experimental study of the aberration properties of holographic optical elements constructed in very thick (750 microns) recording media.

  14. Holographic Jet Quenching

    NASA Astrophysics Data System (ADS)

    Ficnar, Andrej

    In this dissertation we study the phenomenon of jet quenching in quark-gluon plasma using the AdS/CFT correspondence. We start with a weakly coupled, perturbative QCD approach to energy loss, and present a Monte Carlo code for computation of the DGLV radiative energy loss of quarks and gluons at an arbitrary order in opacity. We use the code to compute the radiated gluon distribution up to n=9 order in opacity, and compare it to the thin plasma (n=1) and the multiple soft scattering (n=infinity) approximations. We furthermore show that the gluon distribution at finite opacity depends in detail on the screening mass mu and the mean free path lambda. In the next part, we turn to the studies of how heavy quarks, represented as "trailing strings" in AdS/CFT, lose energy in a strongly coupled plasma. We study how the heavy quark energy loss gets modified in a "bottom-up" non-conformal holographic model, constructed to reproduce some properties of QCD at finite temperature and constrained by fitting the lattice gauge theory results. The energy loss of heavy quarks is found to be strongly sensitive to the medium properties. We use this model to compute the nuclear modification factor RAA of charm and bottom quarks in an expanding plasma with Glauber initial conditions, and comment on the range of validity of the model. The central part of this thesis is the energy loss of light quarks in a strongly coupled plasma. Using the standard model of "falling strings", we present an analytic derivation of the stopping distance of light quarks, previously available only through numerical simulations, and also apply it to the case of Gauss-Bonnet higher derivative gravity. We then present a general formula for computing the instantaneous energy loss in non-stationary string configurations. Application of this formula to the case of falling strings reveals interesting phenomenology, including a modified Bragg-like peak at late times and an approximately linear path dependence. Based

  15. Adjustable liquid aperture to eliminate undesirable light in holographic projection.

    PubMed

    Wang, Di; Liu, Chao; Li, Lei; Zhou, Xin; Wang, Qiong-Hua

    2016-02-01

    In this paper, we propose an adjustable liquid aperture to eliminate the undesirable light in a holographic projection. The aperture is based on hydrodynamic actuation. A chamber is formed with a cylindrical tube. A black droplet is filled in the sidewall of the cylinder tube and the outside space is the transparent oil which is immiscible with the black droplet. An ultrathin glass sheet is attached on the bottom substrate of the device and a black shading film is secured to the central area of the glass sheet. By changing the volume of the black droplet, the black droplet will move to the middle or sidewall due to hydrodynamic actuation, so the device can be used as an adjustable aperture. A divergent spherical wave and a solid lens are used to separate the focus planes of the reconstructed image and diffraction beams induced by the liquid crystal on silicon in the holographic projection. Then the aperture is used to eliminate the diffraction beams by adjusting the size of the liquid aperture and the holographic projection does not have undesirable light. PMID:26906784

  16. Pattern-Recognition Processor Using Holographic Photopolymer

    NASA Technical Reports Server (NTRS)

    Chao, Tien-Hsin; Cammack, Kevin

    2006-01-01

    proposed joint-transform optical correlator (JTOC) would be capable of operating as a real-time pattern-recognition processor. The key correlation-filter reading/writing medium of this JTOC would be an updateable holographic photopolymer. The high-resolution, high-speed characteristics of this photopolymer would enable pattern-recognition processing to occur at a speed three orders of magnitude greater than that of state-of-the-art digital pattern-recognition processors. There are many potential applications in biometric personal identification (e.g., using images of fingerprints and faces) and nondestructive industrial inspection. In order to appreciate the advantages of the proposed JTOC, it is necessary to understand the principle of operation of a conventional JTOC. In a conventional JTOC (shown in the upper part of the figure), a collimated laser beam passes through two side-by-side spatial light modulators (SLMs). One SLM displays a real-time input image to be recognized. The other SLM displays a reference image from a digital memory. A Fourier-transform lens is placed at its focal distance from the SLM plane, and a charge-coupled device (CCD) image detector is placed at the back focal plane of the lens for use as a square-law recorder. Processing takes place in two stages. In the first stage, the CCD records the interference pattern between the Fourier transforms of the input and reference images, and the pattern is then digitized and saved in a buffer memory. In the second stage, the reference SLM is turned off and the interference pattern is fed back to the input SLM. The interference pattern thus becomes Fourier-transformed, yielding at the CCD an image representing the joint-transform correlation between the input and reference images. This image contains a sharp correlation peak when the input and reference images are matched. The drawbacks of a conventional JTOC are the following: The CCD has low spatial resolution and is not an ideal square

  17. Holographic quenches with a gap

    NASA Astrophysics Data System (ADS)

    da Silva, Emilia; Lopez, Esperanza; Mas, Javier; Serantes, Alexandre

    2016-06-01

    In order to holographically model quenches with a gapped final hamiltonian, we consider a gravity-scalar theory in anti-de Sitter space with an infrared hard wall. We allow a time dependent profile for the scalar field at the wall. This induces an energy exchange between bulk and wall and generates an oscillating scalar pulse. We argue that such backgrounds are the counterpart of quantum revivals in the dual field theory. We perform a qualitative comparison with the quench dynamics of the massive Schwinger model, which has been recently analyzed using tensor network techniques. Agreement is found provided the width of the oscillating scalar pulse is inversely linked to the energy density communicated by the quench. We propose this to be a general feature of holographic quenches.

  18. Collinear holographic data storage system

    NASA Astrophysics Data System (ADS)

    Tan, Xiaodi; Lin, Xiao; Wu, Anan

    2013-08-01

    Holographic data storage system is a promising candidate of the next-generation of storage equipment. However, conventional technologies (called 2-axis holography) still have essential issues for commercialization of products. In this paper, we introduce the collinear holography that can produce a small, practical data storage system more easily than conventional 2-axis holography. In this technology the information and reference beams are displayed co-axially by the same SLM. With this unique configuration the optical pickup can be placed on one side of the recording media. The special media structure uses a pre-formatted reflective layer for the focus/tracking servo and for reading address information. It also uses a dichroic mirror interlayer for detecting holographic recording information without interfering with the preformatted information. A 2-dimensional digital page data format is used and the shift-multiplexing method is employed to increase recording density.

  19. Multi-wavelength holographic profilometry

    NASA Astrophysics Data System (ADS)

    Barbosa, E. A.; Gesualdi, M. R.; Muramatsu, M.

    2006-01-01

    A novel method for surface profilometry by holography is presented. We used a diode laser emitting at many wavelengths simultaneously as the light source and a Bi 12TiO 20 (BTO) crystal as the holographic medium in single exposure processes. The employ of multi-wavelength, large free spectral range (FSR) lasers leads to holographic images covered of interference fringes corresponding to the contour lines of the studied surface. In order to obtain the relief of the studied surface, the fringe analysis was performed by the phase stepping technique (PST) and the phase unwrapping was carried out by the Cellular-automata method. We analysed the relief of a tilted flat metallic bar and a tooth prosthesis.

  20. Pion condensation in holographic QCD

    SciTech Connect

    Albrecht, Dylan; Erlich, Joshua

    2010-11-01

    We study pion condensation at zero temperature in a hard-wall holographic model of hadrons with isospin chemical potential. We find that the transition from the hadronic phase to the pion condensate phase is first order except in a certain limit of model parameters. Our analysis suggests that immediately across the phase boundary the condensate acts as a stiff medium approaching the Zel'dovich limit of equal energy density and pressure.

  1. Advances in holographic particle velocimetry

    NASA Astrophysics Data System (ADS)

    Simmons, Scott; Meng, Hui; Hussain, Fazle; Liu, David

    1993-12-01

    Holographic particle velocimetry (HPV) is a promising technique for 3D flow velocity and hence vorticity measurements to study turbulence, coherent structures and vortex interactions. We discuss various aspects in the development of this technique ranging from hologram recording configurations such as in-line, off-axis and multibeam to data processing. Difficulties in implementation are analyzed and solutions are discussed. We also present preliminary measurement results in a 3D vortex flow using one of our prototype HPV systems.

  2. Holographic recording materials - A review

    NASA Technical Reports Server (NTRS)

    Kurtz, R. L.; Owen, R. B.

    1975-01-01

    Holographic recording materials in current use are examined along with a few of their applications. Some experimental media are also studied. No effort is made to rank the commercial materials, since satisfactory results can be obtained with any of them. The discussion covers silver halide plates and films, photoresists, thermoplastics, photopolymers, dichromated gelatin, photochromic materials, electrooptical crystals, styryl free radical film, and TEP film. A convenient summation of some material properties is presented in tabular form.

  3. Sound modes in holographic superfluids

    SciTech Connect

    Herzog, Christopher P.; Yarom, Amos

    2009-11-15

    Superfluids support many different types of sound waves. We investigate the relation between the sound waves in a relativistic and a nonrelativistic superfluid by using hydrodynamics to calculate the various sound speeds. Then, using a particular holographic scalar gravity realization of a strongly interacting superfluid, we compute first, second, and fourth sound speeds as a function of the temperature. The relativistic low temperature results for second sound differ from Landau's well known prediction for the nonrelativistic, incompressible case.

  4. Holographic multiverse and conformal invariance

    SciTech Connect

    Garriga, Jaume; Vilenkin, Alexander E-mail: vilenkin@cosmos.phy.tufts.edu

    2009-11-01

    We consider a holographic description of the inflationary multiverse, according to which the wave function of the universe is interpreted as the generating functional for a lower dimensional Euclidean theory. We analyze a simple model where transitions between inflationary vacua occur through bubble nucleation, and the inflating part of spacetime consists of de Sitter regions separated by thin bubble walls. In this model, we present some evidence that the dual theory is conformally invariant in the UV.

  5. Holographic system for nondestructive testing

    NASA Technical Reports Server (NTRS)

    Kurtz, R. L. (Inventor)

    1975-01-01

    A description is given of a holographic system for nondestructive testing. The system is comprised of a mirror which illuminates the test object surface; the mirror is positionable to direct illumination on an object at varying angles with respect to a line normal to the surface of the object. In this manner holograms may be produced with varying degrees of sensitivity enabling optimum observation of dimensions of deformation of an object occurring between test exposures.

  6. Electromagnetic holographic imaging of bioimpedance

    NASA Astrophysics Data System (ADS)

    Smith, Dexter G.; Ko, Harvey W.; Lee, Benjamin R.; Partin, Alan W.

    1998-05-01

    The electromagnetic bioimpedance method has successfully measured the very subtle conductivity changes associated with brain edema and prostate tumor. This method provides noninvasive measurements using non-ionizing magnetic fields applied with a small coil that avoids the use of contact electrodes. This paper introduces results from combining a holographic signal processing algorithm and a low power coil system that helps provide the 3D image of impedance contrast that should make the noninvasive electromagnetic bioimpedance method useful in health care.

  7. Influence of fabrication conditions on characteristics of phenanthrenequinone-doped poly(methyl methacrylate) photopolymer for holographic memory

    NASA Astrophysics Data System (ADS)

    Lin, Shiuan Huei; Cho, Sheng-Lung; Lin, June-Hua; Hsu, Ken Y.; Chi, Sien

    2014-06-01

    In this paper, we experimentally investigate the influence of the fabrication conditions on holographic characteristics in phenanthrenequinone-doped poly(methyl methacrylate) (PQ:PMMA) bulk photopolymer. In our investigation, the PQ:PMMA bulk samples are fabricated by use of a two-step thermo-polymerization method. We firstly propose to monitor relative viscosity of the monomer solution during the sample preparation to obtain a reliable criterion for material fabrication. We then compare experimentally characteristics of 2-mm thick samples fabricated with different conditions for holographic memory. The results show that the conditions in the first step play a important rule for fabricating bulk PQ:PMMA samples with good optical uniformity. In addition, the conditions in the second step play the rule for controlling the concentration of residual monomer and determine holographic characteristics. These results can provide a useful rule for fabricating bulk PQ:PMMA photopolymers for further applications on volume holographic data storage.

  8. Development of full color holographic optical element recorded on aspherical substrate with photopolymer

    NASA Astrophysics Data System (ADS)

    Piao, Mei-Lan; Wu, Hui-Ying; Kim, Nam

    2014-11-01

    Holographic optical element (HOE) have classically been designed using grating theory, logically so, since an HOE is a grating produced on film by two interfering beams of coherent light. This paper describes the development of full color HOE recorded on aspherical substrate using a photopolymer. The reflection HOE was evaluated by measuring the diffraction efficiencies of holographic volume gratings recorded individually at 633 nm, 532 nm, and 473nm wavelengths. The spectral characterization of the HOE, recorded using a combined single beam, and recorded using sequential beam, was carried out. Practical methods for fabrication of high efficiency aspheric HOE by single layer photopolymer were developed.

  9. Holographic diffraction gratings with enhanced sensitivity based on epoxy-resin photopolymers.

    PubMed

    Jeong, Yong-Cheol; Lee, Seungwoo; Park, Jung-Ki

    2007-02-19

    Photopolymers are interesting materials to obtain high-quality performance for the volume holographic data storage with a low noise and high diffraction efficiency. In this paper, the recording of holographic diffraction gratings with a spatial frequency of 1285lines/mm in photopolymerizable epoxy resin materials is experimentally demonstrated. Diffraction efficiency near 92% and an energetic sensitivity of 11.7 x 10-3cm2/J are achieved by designing the proper structure of matrix and also optimizing photopolymer compositions. The effect of photopolymer compositions on the fundamental optical properties is also discussed. PMID:19532382

  10. RGB digital lensless holographic microscopy

    NASA Astrophysics Data System (ADS)

    Garcia-Sucerquia, Jorge

    2013-11-01

    The recent introduction of color digital lensless holographic microscopy (CDLHM) has shown the possibility of imaging microscopic specimens at full color without the need of lenses. Owing to the simplicity, robustness, and compactness of the digital lensless holographic microscopes (DLHM), they have been presented as the ideal candidates to being developed into portable holographic microscopes. However, in the case of CDLHM the utilization of three independent lasers hinders the portability option for this microscope. In this contribution an alternative to reduce the complexity of CDLHM aimed to recover the portability of this microscopy technology is presented. A super-bright white-light light-emitting diode (LED) is spectrally and spatially filtered to produce the needed illumination by CDLHM to work. CDLHM with LED illumination is used to image at full color a section of the head of a drosophila melanogaster fly (fruit fly). The LED-CDLHM method shows the capability of imaging objects of 2μm size in comparison with the micrometer resolution reported for LASER-CDLHM.

  11. Holographic gunsights for small arms

    NASA Astrophysics Data System (ADS)

    Tai, Anthony M.; Sieczka, Eric J.; Radler, Richard; Upatnieks, Juris

    1996-05-01

    Holographic gunsights were first demonstrated in the mid 1970s by researchers at the Environmental Research Institute of Michigan (ERIM) under contracts with the Air Force and the Army. The sights utilized He-Ne gas lasers and were designed for use with large weapons systems. With the advent of low cost visible laser diode, ERIM formed a new company, EOTech, to develop, manufacture and market a holographic gun sight for small arms. A hologram is used to reconstruct the image of a reticle pattern that appears at the target plane. Unlike red-dot sights, virtually any reticle pattern, 2D or 3D, can be formed. The design challenges include an opto-mechanical package that is compact, light weight and low cost which can withstand recoils up to 4,000 Gs and provide fine elevation/windage pointing adjustments, and optics that are aberration-free and stable over a wide temperature range. Manufacturing challenges include the mass production of high quality holographic optics at low cost and the precision alignment of the very low f/number optics.

  12. Medical applications of holographic stereograms

    NASA Astrophysics Data System (ADS)

    Tsujiuchi, Jumpei

    1991-02-01

    A method for displaying 3D images of medical objects by using holographic stereogram is described together with basic properties of reconstructed images of cylindrical holographic stereograms. INTRODUCTI ON A holographic stereogram (HS) is a synthesized hologram from an original film which consists of a series of ordinary photographs taken from different directions of an object and is possible to apply to an object whose hologram is very difficult or impossible to take with conventional techniques [U. Such a feature of HS can be used for 3D display of medical images such as X-ray images computer assisted tomogrphy (CT) images nuclear magnetic reasonance images (MRI) or ultrasonic images of a patient. CYLINDRICAL HOLOGRAPHI C STEREOGRAMS The original film of the medical HS is taken by rotating around the body axis of a patient a U-shaped arm equipment one end of which has a pulse X-ray source and the other end a movie camera with an image intensifier [2]. Synthesis of HS is carried out by using a special optical system the hologram is shaped into a cylinder and is reconstructed by illuminating the hologram with a small white light source located on the axis of the cylinder. Such a HS is called multiplex hologram (MH) the most popular HS and the reconstructed image can be observed in the cylinder. The formation of reconstructed image is made in unusual way and fundamental properties

  13. Quantifying Bulk Electrode Strain and Material Displacement within Lithium Batteries via High‐Speed Operando Tomography and Digital Volume Correlation

    PubMed Central

    Finegan, Donal P.; Tudisco, Erika; Scheel, Mario; Robinson, James B.; Taiwo, Oluwadamilola O.; Eastwood, David S.; Lee, Peter D.; Di Michiel, Marco; Bay, Brian; Hall, Stephen A.; Hinds, Gareth; Brett, Dan J. L.

    2015-01-01

    Tracking the dynamic morphology of active materials during operation of lithium batteries is essential for identifying causes of performance loss. Digital volume correlation (DVC) is applied to high‐speed operando synchrotron X‐ray computed tomography of a commercial Li/MnO2 primary battery during discharge. Real‐time electrode material displacement is captured in 3D allowing degradation mechanisms such as delamination of the electrode from the current collector and electrode crack formation to be identified. Continuum DVC of consecutive images during discharge is used to quantify local displacements and strains in 3D throughout discharge, facilitating tracking of the progression of swelling due to lithiation within the electrode material in a commercial, spiral‐wound battery during normal operation. Displacement of the rigid current collector and cell materials contribute to severe electrode detachment and crack formation during discharge, which is monitored by a separate DVC approach. Use of time‐lapse X‐ray computed tomography coupled with DVC is thus demonstrated as an effective diagnostic technique to identify causes of performance loss within commercial lithium batteries; this novel approach is expected to guide the development of more effective commercial cell designs. PMID:27610334

  14. Excluded volume and ion-ion correlation effects on the ionic atmosphere around B-DNA: Theory, simulations, and experiments

    NASA Astrophysics Data System (ADS)

    Ovanesyan, Zaven; Medasani, Bharat; Fenley, Marcia O.; Guerrero-García, Guillermo Iván; Olvera de la Cruz, Mónica; Marucho, Marcelo

    2014-12-01

    The ionic atmosphere around a nucleic acid regulates its stability in aqueous salt solutions. One major source of complexity in biological activities involving nucleic acids arises from the strong influence of the surrounding ions and water molecules on their structural and thermodynamic properties. Here, we implement a classical density functional theory for cylindrical polyelectrolytes embedded in aqueous electrolytes containing explicit (neutral hard sphere) water molecules at experimental solvent concentrations. Our approach allows us to include ion correlations as well as solvent and ion excluded volume effects for studying the structural and thermodynamic properties of highly charged cylindrical polyelectrolytes. Several models of size and charge asymmetric mixtures of aqueous electrolytes at physiological concentrations are studied. Our results are in good agreement with Monte Carlo simulations. Our numerical calculations display significant differences in the ion density profiles for the different aqueous electrolyte models studied. However, similar results regarding the excess number of ions adsorbed to the B-DNA molecule are predicted by our theoretical approach for different aqueous electrolyte models. These findings suggest that ion counting experimental data should not be used alone to validate the performance of aqueous DNA-electrolyte models.

  15. Excluded volume and ion-ion correlation effects on the ionic atmosphere around B-DNA: Theory, simulations, and experiments

    SciTech Connect

    Ovanesyan, Zaven; Marucho, Marcelo; Medasani, Bharat; Fenley, Marcia O.; Guerrero-García, Guillermo Iván; Olvera de la Cruz, Mónica

    2014-12-14

    The ionic atmosphere around a nucleic acid regulates its stability in aqueous salt solutions. One major source of complexity in biological activities involving nucleic acids arises from the strong influence of the surrounding ions and water molecules on their structural and thermodynamic properties. Here, we implement a classical density functional theory for cylindrical polyelectrolytes embedded in aqueous electrolytes containing explicit (neutral hard sphere) water molecules at experimental solvent concentrations. Our approach allows us to include ion correlations as well as solvent and ion excluded volume effects for studying the structural and thermodynamic properties of highly charged cylindrical polyelectrolytes. Several models of size and charge asymmetric mixtures of aqueous electrolytes at physiological concentrations are studied. Our results are in good agreement with Monte Carlo simulations. Our numerical calculations display significant differences in the ion density profiles for the different aqueous electrolyte models studied. However, similar results regarding the excess number of ions adsorbed to the B-DNA molecule are predicted by our theoretical approach for different aqueous electrolyte models. These findings suggest that ion counting experimental data should not be used alone to validate the performance of aqueous DNA-electrolyte models.

  16. Correlation of intracystic pressure with cyst volume, length of common channel, biochemical changes in bile and histopathological changes in liver in choledochal cyst

    PubMed Central

    Sharma, Nitin; Bhatnagar, Veereshwar; Srinivas, M.; Agarwala, Sandeep; Singh, Manoj Kumar; Sharma, Raju

    2014-01-01

    Aims: This study was undertaken to establish correlation between intracholedochal cystic pressure (ICCP) with biochemical changes in bile, liver histology, cyst wall histology, length of common channel, and cyst volume. Materials and Methods: In this cross-sectional study, ICCP was measured after surgical access before any mobilization by direct cyst cannulation. Bile was then aspirated for biochemical estimation (bilirubin, amylase, lipase, pH, and electrolytes). Common channel length and cyst volume were determined by preoperative magnetic resonance cholangiopancreatography (MRCP). Liver histology was assessed under parenchymal, bile duct, and portal parameters. Cyst wall was examined for ulceration, inflammation, fibrosis, and metaplasia. Results: ICCP was recorded in 31 patients; mean and median ICCP were 15.64 and 14 mmHg, respectively (range = 6-30 mmHg). Cases with median ICCP < 14 had median cyst volume of 48 cc (range = 36-115) and amylase 2052 IU/L (range = 190-5052) whereas those with ICCP ≥ 15 had volume of 20 cc (range = 10-100) (P = 0.004) and amylase 36 IU/L (range = 0-2806) (P = 0.0004) suggesting inverse correlation. No significant correlation was found with bilirubin and electrolytes. ICCP directly correlated with parenchymal changes like hepatocellular damage (P = 0.002) and cholestasis (P = 0.001). It also correlated with bile duct changes. ICCP inversely correlated with cyst wall changes (P = 0.003, 0.0001, 0.023, 0.0013, respectively). High pressure cysts had normal pancreaticobiliary junction. Conclusion: High-pressure cysts tend to be smaller but have more severe backpressure changes in liver parenchyma. Low-pressure cysts have high volume and higher levels of amylase and lipase and therefore have more severe cyst wall changes. PMID:24604978

  17. Monitoring by holographic radar systems

    NASA Astrophysics Data System (ADS)

    Catapano, Ilaria; Crocco, Lorenzo; Affinito, Antonio; Gennarelli, Gianluca; Soldovieri, Francesco

    2013-04-01

    Nowadays, radar technology represents a significant opportunity to collect useful information for the monitoring and conservation of critical infrastructures. Radar systems exploit the non-invasive interaction between the matter and the electromagnetic waves at microwave frequencies. Such an interaction allows obtaining images of the region under test from which one can infer the presence of potential anomalies such as deformations, cracks, water infiltrations, etc. This information turns out to be of primary importance in practical scenarios where the probed structure is in a poor state of preservation and renovation works must be planned. In this framework, the aim of this contribution is to describe the potentialities of the holographic radar Rascan 4/4000, a holographic radar developed by Remote Sensing Laboratory of Bauman Moscow State Technical University, as a non-destructive diagnostic tool capable to provide, in real-time, high resolution subsurface images of the sounded structure [1]. This radar provides holograms of hidden anomalies from the amplitude of the interference signal arising between the backscattered signal and a reference signal. The performance of the holographic radar is appraised by means of several experiments. Preliminary tests concerning the imaging below the floor and inside wood structures are carried out in controlled conditions at the Electromagnetic Diagnostic Laboratory of IREA-CNR. After, with reference to bridge monitoring for security aim, the results of a measurement campaign performed on the Musmeci bridge are presented [2]. Acknowledgments This research has been performed in the framework of the "Active and Passive Microwaves for Security and Subsurface imaging (AMISS)" EU 7th Framework Marie Curie Actions IRSES project (PIRSES-GA-2010-269157). REFERENCES [1] S. Ivashov, V. Razevig, I. Vasilyev, A. Zhuravlev, T. Bechtel, L. Capineri, The holographic principle in subsurface radar technology, International Symposium to

  18. Measurement of temperature and temperature distribution in gaseous flames by digital speckle pattern shearing interferometry using holographic optical element

    NASA Astrophysics Data System (ADS)

    Kumar, Manoj; Shakher, Chandra

    2015-10-01

    Digital speckle pattern lateral shear interferometry (DSPSI) based on volume phase holographic grating for the measurement of temperature and temperature distribution in candle flames is presented. The DSPSI setup uses the volume phase holographic grating combined with ground glass to shear the wavefronts. The shear of the two wavefronts is controlled by the distance between volume phase holographic grating and the ground glass. The sheared wavefronts on the ground glass are imaged onto the CMOS detector by an imaging lens. Two specklegrams are recorded corresponding to the absence of the flame and the presence of the flame. The fringe pattern is observed by subtracting these two specklegrams. A single fringe pattern was used to extract phase by the application of Riesz transform and the monogenic signal. The measured values of the temperature of the candle flame by DSPSI is compared with that of R-type Platinum-Platinum Rhodium thermocouple and the results are well within experimental limits.

  19. Color holographic display with white light LED source and single phase only SLM.

    PubMed

    Kozacki, Tomasz; Chlipala, Maksymilian

    2016-02-01

    This work presents color holographic display, which is based on a single phase only spatial light modulator (SLM). In the display entire area of the SLM is illuminated by an on-axis white light beam generated by a single large LED. The holographic display fully utilizes SLM bandwidth and has capability of full-color, full frame rate imaging of outstanding quality. This is achieved through: (i) optimal use of the source coherence volume, (ii) application of the single white light LED source, (iii) a development of a novel concept of color multiplexing technique with color filter mask in Fourier plane of the SLM, (iv) and a complex coding with improved diffraction efficiency. Within experimental part of the paper we show single color, full-color holographic 2D and 3D images generated for reconstruction depth exceeding 10 cm. PMID:26906795

  20. Highly effective dynamic holographic gratings in doped bismuth titanate crystals and applications to metrology

    NASA Astrophysics Data System (ADS)

    Dovgalenko, George E.; Wu, Ying

    2009-05-01

    Highly efficient volume reflective, dynamical holographic gratings in doped Ti12TiO20 crystals have been observed. We demonstrated doped Ti12TiO20 single, electro-optical crystal and experimental set up, which combines high reversibility, small response time, high diffraction efficiency and practically unlimited number of cycles hologram recording, readout and erasing. It allows using doped Ti12TiO20 crystal as an attractive diffractive optical element in Dynamical Holographic Sensor -DHS for metrology applications. The high image contrast of the real time dynamical holographic interferograms without application of external electric field has been obtained for non transparent diffuse reflective objects using commercial available CW He-Ne laser. DHS applications for nondestructive test of the most vital parts engineering constructions to prevent premature failure have has been demonstrated. DHS application for visualization of cryogenic fields in the near zone of cryoultrasonic cancer tissue destructor has been presented.

  1. High efficiency panchromatic photopolymer recording material for holographic data storage systems

    NASA Astrophysics Data System (ADS)

    Pramitha, Vayalamkuzhi; Das, Bhargab; Joseph, Joby; Joseph, Rani; Sreekumar, Krishnapillai; Kartha, Cheranellore Sudha

    2016-02-01

    Studies carried out to gauge the potential of a metal-ion doped panchromatic photopolymer recording material for application in real-time holographic data storage is presented. The photopolymer films are spin coated on glass plates to ensure better surface uniformity. Volume holographic transmission gratings with peak diffraction efficiency of 80% could be stored in the photopolymer films of 100 μm thickness. An efficiency of 70% is achievable even for gratings recorded with exposure energy as low as 10 mJ/cm2. A checkerboard pattern data page recorded in the photopolymer film using a defocused 4-f recording geometry could be reconstructed with good image quality. The experimental results illustrate the competency of the developed photopolymer for holographic data storage applications.

  2. Correlations between magnetic switching volume and magnetic and nanostructural properties of CoSm//Cr films (abstract)

    NASA Astrophysics Data System (ADS)

    Shan, Z. S.; Malhotra, S. S.; Zhang, Y. B.; Liou, S. H.; Sellmyer, D. J.

    1997-04-01

    CoSm films with a Cr underlayer (CoSm//Cr) are promising as future high density recording media.1 It was pointed out that the grain size in media affects the media noise and thermal stability significantly. However, if small grains are exchange coupled to form larger "magnetic grains," the size of these magnetic clusters will be important in noise considerations. Our previous works23 indicated that for CoSm film with Cr underlayer the magnetic grain size is much larger than the 50 Å nanocrystallites and is about the same size as the Cr grain of ˜240 Å in dimension. In the present work, we report our systematic studies of magnetic switching volume and its correlation with magnetic and nanostructural properties for CoSm films. Switching volumes V* were measured with the "field sweep-rate dependence of coercivity Hc," interactions among the magnetic grains were estimated with the so-called ΔM method, and the nanostructures were investigated with atomic force microscopy and transmission electron microscopy. The thickness of CoSm layers, which were sputtered in an Ar pressure PAr=25 mT, is 300 Å for all samples. It is found that as the Cr underlayer thickness dCr increases from 0 Å (without a Cr underlayer) to 200 Å, the V* and ΔMmax decrease (Hc increases) rapidly, i.e., from V* from 9.3×10-18 to 5.7×10-18 cm3, ΔMmax from 1.3 to 0.5 (Hc from 1.4 to 2.3 kOe), respectively, and then gradually as dCr approaches 800 Å. As Ar pressure PAr of the deposition of the Cr underlayer varies from 5 to 30 mT, the V* and ΔMmax have their minima (anisotropy Ku has its maximum) at PAr≃9.5 mT. V* shows minima at dCr and PAr values where Hc and Ku have their maxima and ΔMmax has a small value. This behavior can be interpreted with a thermal activation model including interactions between magnetic grains. The relationship between crystallite grain size, magnetic grain V*, and media noise will be discussed.

  3. Holographic brain: a good analogy gone bad

    NASA Astrophysics Data System (ADS)

    Caulfield, H. John

    2002-07-01

    One way of honoring the world's two greatest holographers is to remove from their field the association with the offbeat world of the holographic mind. Basing itself on analogical musings of two very creative scientists who were themselves not holographers, this 'field' of the holographic brain has strayed far from science and into the absurd. So much absurdity has been written by so many people that the one legitimate study of holographic principle in dolphins has been grouped too often with the nonsense. Here is taken most of the 'target statements' form one book. We could not bear to read them all this closely. We will attempt to determine what tidbit of fact led to the statements and to suggest alternative explanations when there is something to explain.

  4. Correlations of Metabolic Components with Prostate Volume in Middle-Aged Men Receiving Health Check-Up

    PubMed Central

    Yang, Hung-Ju; Chang, Hong-Chiang; Hsieh, Ju-Ton; Huang, Kuo-How

    2016-01-01

    Objectives To investigate the impact of metabolic components and body composition indices on prostate volume (PV) in a population of middle-aged men receiving health check-ups. Methods Six hundred and sixteen men receiving health assessments were stratified to large and small prostates based on the cut-off of median PV. Their demographic data, health history, and international prostate symptoms scores (IPSS) were collected. Metabolic components and body composition indices were compared between subjects with large and small prostates. Moreover, the correlations between these parameters and PV were analyzed by multivariate logistic regression. Results The median PV was 27 mL and mean age was 54.8 years. Subjects with large PV were older (56.5 vs. 52.7 years) and had higher serum prostate specific antigen (PSA) level (1.73 vs. 0.96 ng/mL), higher IPSS score (8.37 vs. 6.16), and higher body fat, body mass, and waist circumference (all p<0.05). In multivariate analysis, age (OR, 2.45; 95%CI, 1.74–3.45), serum PSA (OR, 2.75; 95%CI, 1.96–3.86), waist circumference (OR, 1.45; 95%CI, 1.02–2.07), fatness (OR, 1.47; 95%CI, 1.04–2.09), and body fat mass (OR, 1.43; 95%CI, 1.00–2.03) were significantly correlated with PV of study subjects. In subgroup analysis, raised waist circumference (OR, 1.89; 95%CI, 1.00–3.59) was the independent predictor of PV in subjects with bothersome lower urinary tract symptoms. Conclusions Several metabolic components and body composition indices are significantly associated with PV of middle-aged men, including raised waist circumference, fatness, and body fat mass. Raised waist circumference is the only independent predictor of PV in middle-aged men with bothersome LUTS. PMID:26731481

  5. Increasing the Accuracy of Volume and ADC Delineation for Heterogeneous Tumor on Diffusion-Weighted MRI: Correlation with PET/CT

    SciTech Connect

    Gong, Nan-Jie; Wong, Chun-Sing; Chu, Yiu-Ching; Guo, Hua; Huang, Bingsheng; Chan, Queenie

    2013-10-01

    Purpose: To improve the accuracy of volume and apparent diffusion coefficient (ADC) measurements in diffusion-weighted magnetic resonance imaging (MRI), we proposed a method based on thresholding both the b0 images and the ADC maps. Methods and Materials: In 21 heterogeneous lesions from patients with metastatic gastrointestinal stromal tumors (GIST), gross lesion were manually contoured, and corresponding volumes and ADCs were denoted as gross tumor volume (GTV) and gross ADC (ADC{sub g}), respectively. Using a k-means clustering algorithm, the probable high-cellularity tumor tissues were selected based on b0 images and ADC maps. ADC and volume of the tissues selected using the proposed method were denoted as thresholded ADC (ADC{sub thr}) and high-cellularity tumor volume (HCTV), respectively. The metabolic tumor volume (MTV) in positron emission tomography (PET)/computed tomography (CT) was measured using 40% maximum standard uptake value (SUV{sub max}) as the lower threshold, and corresponding mean SUV (SUV{sub mean}) was also measured. Results: HCTV had excellent concordance with MTV according to Pearson's correlation (r=0.984, P<.001) and linear regression (slope = 1.085, intercept = −4.731). In contrast, GTV overestimated the volume and differed significantly from MTV (P=.005). ADC{sub thr} correlated significantly and strongly with SUV{sub mean} (r=−0.807, P<.001) and SUV{sub max} (r=−0.843, P<.001); both were stronger than those of ADC{sub g}. Conclusions: The proposed lesion-adaptive semiautomatic method can help segment high-cellularity tissues that match hypermetabolic tissues in PET/CT and enables more accurate volume and ADC delineation on diffusion-weighted MR images of GIST.

  6. Linear and curvilinear correlations of brain gray matter volume and density with age using voxel-based morphometry with the Akaike information criterion in 291 healthy children.

    PubMed

    Taki, Yasuyuki; Hashizume, Hiroshi; Thyreau, Benjamin; Sassa, Yuko; Takeuchi, Hikaru; Wu, Kai; Kotozaki, Yuka; Nouchi, Rui; Asano, Michiko; Asano, Kohei; Fukuda, Hiroshi; Kawashima, Ryuta

    2013-08-01

    We examined linear and curvilinear correlations of gray matter volume and density in cortical and subcortical gray matter with age using magnetic resonance images (MRI) in a large number of healthy children. We applied voxel-based morphometry (VBM) and region-of-interest (ROI) analyses with the Akaike information criterion (AIC), which was used to determine the best-fit model by selecting which predictor terms should be included. We collected data on brain structural MRI in 291 healthy children aged 5-18 years. Structural MRI data were segmented and normalized using a custom template by applying the diffeomorphic anatomical registration using exponentiated lie algebra (DARTEL) procedure. Next, we analyzed the correlations of gray matter volume and density with age in VBM with AIC by estimating linear, quadratic, and cubic polynomial functions. Several regions such as the prefrontal cortex, the precentral gyrus, and cerebellum showed significant linear or curvilinear correlations between gray matter volume and age on an increasing trajectory, and between gray matter density and age on a decreasing trajectory in VBM and ROI analyses with AIC. Because the trajectory of gray matter volume and density with age suggests the progress of brain maturation, our results may contribute to clarifying brain maturation in healthy children from the viewpoint of brain structure. PMID:22505237

  7. 4D analysis of the microstructural evolution of Si-based electrodes during lithiation: Time-lapse X-ray imaging and digital volume correlation

    NASA Astrophysics Data System (ADS)

    Paz-Garcia, J. M.; Taiwo, O. O.; Tudisco, E.; Finegan, D. P.; Shearing, P. R.; Brett, D. J. L.; Hall, S. A.

    2016-07-01

    Silicon is a promising candidate to substitute or complement graphite as anode material in Li-ion batteries due, mainly, to its high energy density. However, the lithiation/delithiation processes of silicon particles are inherently related to drastic volume changes which, within a battery's physically constrained case, can induce significant deformation of the fundamental components of the battery that can eventually cause it to fail. In this work, we use non-destructive time-lapse X-ray imaging techniques to study the coupled electrochemo-mechanical phenomena in Li-ion batteries. We present X-ray computed tomography data acquired at different times during the first lithiation of custom-built silicon-lithium battery cells. Microstructural volume changes have been quantified using full 3D strain field measurements from digital volume correlation analysis. Furthermore, the extent of lithiation of silicon particles has been quantified in 3D from the grey-scale of the tomography images. Correlation of the volume expansion and grey-scale changes over the silicon-based electrode volume indicates that the process of lithiation is kinetically affected by the reaction at the Si/LixSi interface.

  8. Differences in cognitive ability and hippocampal volume between Alzheimer's disease, amnestic mild cognitive impairment, and healthy control groups, and their correlation.

    PubMed

    Choi, Mi-Hyun; Kim, Hyung-Sik; Gim, Seon-Young; Kim, Woo-Ram; Mun, Kyung-Ryul; Tack, Gye-Rae; Lee, Bongsoo; Choi, Young Chil; Kim, Hyun-Jun; Hong, Seung Hwa; Lim, Dae-Woon; Chung, Soon-Cheol

    2016-05-01

    The study investigated differences in cognitive ability and hippocampal volume between groups of patients with Alzheimer's disease (AD) and amnestic mild cognitive impairment (aMCI), and healthy control (HC) subjects, and explored the relationship between cognitive ability and hippocampal volume. Among the sub-tests of Korean version of the Consortium to Establish a Registry for Alzheimer's Disease (CERAD-K), the Boston naming test score decreased in the order HC, aMCI, and AD. The hippocampal volumes of subjects with AD and aMCI were relatively smaller than those of HC individuals. There were strongly positive correlations between hippocampal volume and the scores for the Boston naming test. Discriminant analysis identified the Boston naming test as having the highest level of discrimination among the variables used to differentiate the three groups (89.9%). In conclusion, the Boston naming test accurately differentiated the three groups and was correlated with hippocampal volume. These results will be helpful for choosing an accurate and economically feasible test method that efficiently differentiates the three groups. PMID:27019036

  9. Acceleration and holographic studies on different types of dynamization of external fixators of the bones

    NASA Astrophysics Data System (ADS)

    Podbielska, Halina; Kasprzak, Henryk T.; Voloshin, Arkady S.; Pennig, Dietmar; von Bally, Gert

    1992-08-01

    The unilateral axially dynamic fixator (Orthofix) was mounted on a sheep tibial shaft. Three fixation modes: static, dynamic controlled, and dynamic free were examined by means of double exposure holographic interferometry. Simultaneously, the acceleration was measured by an accelerometer and displayed on the monitor together with loading characteristics. The first exposure was made before the acting force was applied to the tibia plateau. The second one after the moment when the acceleration wave started to propagate through the specimen. We stated that in the case of dynamization less torsion occurs at the fracture site. So far, we have not been able to determine any correlation between results of holographic and accelerometric measurements.

  10. 50 years of holographic interferometry

    NASA Astrophysics Data System (ADS)

    Stetson, Karl A.

    2015-01-01

    Fifty years ago, Robert L. Powell and I discovered holographic interferometry while working at the Radar Laboratory of the University of Michigan's Institute of Science and Technology. I have worked in this field for this entire time span, watched it grow from an unexplored technology to become a widespread industrial testing method, and I have contributed to these developments. In this paper, I will trace my history in this field from our discovery to my involvement in its theory and applications. I will conclude with a discussion of digital holography, which is currently replacing photographic holography for most research and industrial applications.

  11. Holographic storage of multicolor information.

    NASA Technical Reports Server (NTRS)

    Burton, G. T.; Clay, B. R.

    1972-01-01

    Discussion of the merits of the use of holography for storing multicolor information. Holography is shown capable to provide in a compact, easily duplicated, inexpensive, and readily retrievable manner the storage capacity required for the ever growing amounts of alphanumeric, graphic, continuous tone, color, and black-and-white data generated. Following a definition of the holographic concept, the advantages of holography for multicolor information recording, indexing, registration, and reconstruction are reviewed. Special attention is given to display applications including a multicolor moving-map display, a NASA multifunction display, and an automatic-test-equipment information storage system.

  12. 3D holographic head mounted display using holographic optical elements with astigmatism aberration compensation.

    PubMed

    Yeom, Han-Ju; Kim, Hee-Jae; Kim, Seong-Bok; Zhang, HuiJun; Li, BoNi; Ji, Yeong-Min; Kim, Sang-Hoo; Park, Jae-Hyeung

    2015-12-14

    We propose a bar-type three-dimensional holographic head mounted display using two holographic optical elements. Conventional stereoscopic head mounted displays may suffer from eye fatigue because the images presented to each eye are two-dimensional ones, which causes mismatch between the accommodation and vergence responses of the eye. The proposed holographic head mounted display delivers three-dimensional holographic images to each eye, removing the eye fatigue problem. In this paper, we discuss the configuration of the bar-type waveguide head mounted displays and analyze the aberration caused by the non-symmetric diffraction angle of the holographic optical elements which are used as input and output couplers. Pre-distortion of the hologram is also proposed in the paper to compensate the aberration. The experimental results show that proposed head mounted display can present three-dimensional see-through holographic images to each eye with correct focus cues. PMID:26698993

  13. Digital holographic microscopy combined with optical tweezers

    NASA Astrophysics Data System (ADS)

    Cardenas, Nelson; Yu, Lingfeng; Mohanty, Samarendra K.

    2011-02-01

    While optical tweezers have been widely used for the manipulation and organization of microscopic objects in three dimensions, observing the manipulated objects along axial direction has been quite challenging. In order to visualize organization and orientation of objects along axial direction, we report development of a Digital holographic microscopy combined with optical tweezers. Digital holography is achieved by use of a modified Mach-Zehnder interferometer with digital recording of interference pattern of the reference and sample laser beams by use of a single CCD camera. In this method, quantitative phase information is retrieved dynamically with high temporal resolution, only limited by frame rate of the CCD. Digital focusing, phase-unwrapping as well as online analysis and display of the quantitative phase images was performed on a software developed on LabView platform. Since phase changes observed in DHOT is very sensitive to optical thickness of trapped volume, estimation of number of particles trapped in the axial direction as well as orientation of non-spherical objects could be achieved with high precision. Since in diseases such as malaria and diabetics, change in refractive index of red blood cells occurs, this system can be employed to map such disease-specific changes in biological samples upon immobilization with optical tweezers.

  14. Digital holographic microscopy for microalgae biovolume assessment

    NASA Astrophysics Data System (ADS)

    Monaldi, Andrea C.; Romero, Gladis G.; Alanís, Elvio E.; Cabrera, Carlos M.

    2015-02-01

    The relative amount of biomass in a body of water is one of the various indicators widely used in water quality evaluation. This implies complex tasks such as identification and characterization of microorganisms and measurement of their biovolume. Particularly, the latter is estimated by assuming simple geometrical shapes for the microorganism and by calculating its dimensions from images taken with a conventional microscope. In order to have a more precise and automatic method for biovolume evaluation, a hybrid methodology based on digital holographic microscopy and image processing is proposed. The whole volume of a specimen under study is obtained combining the phase contrast image of an off-axis hologram with the thickness-profile data of the specimen extracted from the cell silhouette. This technique has been used for determining the biovolume of Ceratium Hirundinella cells in water samples. The methodology proposed also shows that it is possible to estimate accurately an effective refractive index of the microorganism. Experimental results have shown that this technique is not only an efficient and fast alternative, but also suitable for automatizing the entire process.

  15. Moving through a multiplex holographic scene

    NASA Astrophysics Data System (ADS)

    Mrongovius, Martina

    2013-02-01

    This paper explores how movement can be used as a compositional element in installations of multiplex holograms. My holographic images are created from montages of hand-held video and photo-sequences. These spatially dynamic compositions are visually complex but anchored to landmarks and hints of the capturing process - such as the appearance of the photographer's shadow - to establish a sense of connection to the holographic scene. Moving around in front of the hologram, the viewer animates the holographic scene. A perception of motion then results from the viewer's bodily awareness of physical motion and the visual reading of dynamics within the scene or movement of perspective through a virtual suggestion of space. By linking and transforming the physical motion of the viewer with the visual animation, the viewer's bodily awareness - including proprioception, balance and orientation - play into the holographic composition. How multiplex holography can be a tool for exploring coupled, cross-referenced and transformed perceptions of movement is demonstrated with a number of holographic image installations. Through this process I expanded my creative composition practice to consider how dynamic and spatial scenes can be conveyed through the fragmented view of a multiplex hologram. This body of work was developed through an installation art practice and was the basis of my recently completed doctoral thesis: 'The Emergent Holographic Scene — compositions of movement and affect using multiplex holographic images'.

  16. Holographic tracking of living cells by three-dimensional reconstructed complex wavefronts alignment.

    PubMed

    Memmolo, Pasquale; Miccio, Lisa; Finizio, Andrea; Netti, Paolo A; Ferraro, Pietro

    2014-05-01

    We propose here a new three-dimensional (3D) holographic tracking method capable to track, simultaneously and in a single step, all the spatial coordinates of micro-objects. The approach is based on the enhanced correlation coefficient (ECC) maximization method but applied, for the first time to the best of our knowledge, directly on the holographic reconstructed complex wave fields. The key novelty of the proposed strategy is its ability to calculate simultaneously the 3D coordinates of cells, without decoupling the contribution of amplitude and phase. The proposed strategy is tested on living cells (i.e., NIH 3T3 mouse fibroblast) flowing into a microfluidic channel and compared with classical holographic tracking approach. Theoretical description and experimental validation of the proposed strategy are reported. PMID:24784096

  17. Holographic recording characteristics and applications of single-layer panchromatic dichromated gelatin material

    NASA Astrophysics Data System (ADS)

    Zhu, Jianhua; Xu, Min; Chen, Ligong; Guo, Yongkang; Guo, Lurong

    2005-09-01

    A high-quality single-layer panchromatic dichromated gelatin material is achieved successfully by employing new types of multi-color photosensitizers and photochemical promoters to conventional photo-crosslinking gelatin system. Its holographic recording characteristics such as spectral response, the photosensitivity of three primary colors, spectral selectivity of volume reflection hologram, angular and wavelength selectivity of volume transmission hologram, are studied in detail. Using red, green and blue lasers, namely three primary colors, the bright volume transmission and reflection holograms can be recorded on the panchromatic material at the exposure level of 30 mJ/cm2. Some preliminary results of space, angle and wavelength multiplexing holographic storage for storing multiple binary and grey-tone optical images, are also reported in this paper.

  18. Apoptotic markers in cultured fibroblasts correlate with brain metabolites and regional brain volume in antipsychotic-naive first-episode schizophrenia and healthy controls.

    PubMed

    Batalla, A; Bargalló, N; Gassó, P; Molina, O; Pareto, D; Mas, S; Roca, J M; Bernardo, M; Lafuente, A; Parellada, E

    2015-01-01

    Cultured fibroblasts from first-episode schizophrenia patients (FES) have shown increased susceptibility to apoptosis, which may be related to glutamate dysfunction and progressive neuroanatomical changes. Here we determine whether apoptotic markers obtained from cultured fibroblasts in FES and controls correlate with changes in brain glutamate and N-acetylaspartate (NAA) and regional brain volumes. Eleven antipsychotic-naive FES and seven age- and gender-matched controls underwent 3-Tesla magnetic resonance imaging scanning. Glutamate plus glutamine (Glx) and NAA levels were measured in the anterior cingulate (AC) and the left thalamus (LT). Hallmarks of apoptotic susceptibility (caspase-3-baseline activity, phosphatidylserine externalization and chromatin condensation) were measured in fibroblast cultures obtained from skin biopsies after inducing apoptosis with staurosporine (STS) at doses of 0.25 and 0.5 μM. Apoptotic biomarkers were correlated to brain metabolites and regional brain volume. FES and controls showed a negative correlation in the AC between Glx levels and percentages of cells with condensed chromatin (CC) after both apoptosis inductions (STS 0.5 μM: r = -0.90; P = 0.001; STS 0.25 μM: r = -0.73; P = 0.003), and between NAA and cells with CC (STS 0.5 μM induction r = -0.76; P = 0.002; STS 0.25 μM r = -0.62; P = 0.01). In addition, we found a negative correlation between percentages of cells with CC and regional brain volume in the right supratemporal cortex and post-central region (STS 0.25 and 0.5 μM; P < 0.05 family-wise error corrected (FWEc)). We reveal for the first time that peripheral markers of apoptotic susceptibility may correlate with brain metabolites, Glx and NAA, and regional brain volume in FES and controls, which is consistent with the neuroprogressive theories around the onset of the schizophrenia illness. PMID:26305477

  19. Intellectual property analysis of holographic materials business

    NASA Astrophysics Data System (ADS)

    Reingand, Nadya; Hunt, David

    2006-02-01

    The paper presents an overview of intellectual property in the field of holographic photosensitive materials and highlights the possibilities offered by patent searching and analysis. Thousands of patent documents relevant to holographic materials have been uncovered by the study. The search was performed in the following databases: U.S. Patent Office, European Patent Office, and Japanese Patent Office for the time frame of 1971 through November 2005. The patent analysis has unveiled trends in patent temporal distribution, leading IP portfolios, companies competition within the holographic materials market and other interesting insights.

  20. Holographic Methods in X-ray Crystallography

    Energy Science and Technology Software Center (ESTSC)

    1995-07-28

    The holographic method makes use of partially modeled electron density and experimentally-measured structure factor amplitudes to recover electron density corresponding to the unmodeled part of a crystal structure. This paper describes a fast algorithm that makes it possible to apply the holographic method to sizable crystallographic problems. The algorithm uses positivity constraints on the electron density, and can incorporate a target electron density, making it similar to solvent flattening. Using both synthetic and experimental data,more » we assess the potential for applying the holographic method to macromolecular x-ray crystallography.« less

  1. Exploring holographic Composite Higgs models

    NASA Astrophysics Data System (ADS)

    Croon, Djuna; Dillon, Barry M.; Huber, Stephan J.; Sanz, Veronica

    2016-07-01

    Simple Composite Higgs models predict new vector-like fermions not too far from the electroweak scale, yet LHC limits are now sensitive to the TeV scale. Motivated by this tension, we explore the holographic dual of the minimal model, MCHM5, to try and alleviate this tension without increasing the fine-tuning in the Higgs potential. Interestingly, we find that lowering the UV cutoff in the 5D picture allows for heavier top partners and less fine-tuning. In the 4D dual this corresponds to increasing the number of "colours" N , thus increasing the decay constant of the Goldstone Higgs. This is essentially a `Little Randall-Sundrum Model', which are known to reduce some flavour and electroweak constraints. Furthermore, in anticipation of the ongoing efforts at the LHC to put bounds on the top Yukawa, we demonstrate that deviations from the SM can be suppressed or enhanced with respect to what is expected from mere symmetry arguments in 4D. We conclude that the 5D holographic realisation of the MCHM5 with a small UV cutoff is not in tension with the current experimental data.

  2. Holographic baryons from oblate instantons

    NASA Astrophysics Data System (ADS)

    Rozali, Moshe; Stang, Jared B.; Van Raamsdonk, Mark

    2014-02-01

    We investigate properties of baryons in a family of holographic field theories related to the Sakai-Sugimoto model of holographic QCD. Starting with the N f = 2 Sakai-Sugimoto model, we truncate to a 5D Yang-Mills action for the gauge fields associated with the noncompact directions of the flavor D8-branes. We define a free parameter γ that controls the strength of this Yang-Mills term relative to the Chern-Simons term that couples the Abelian gauge field to the SU(2) instanton density. Moving away from γ = 0 should incorporate some of the effects of taking the Sakai-Sugimoto model away from large 't Hooft coupling λ. In this case, the baryon ground state corresponds to an oblate SU(2) instanton on the bulk flavor branes: the usual SO(4) symmetric instanton is deformed to spread more along the field theory directions than the radial direction. We numerically construct these anisotropic instanton solutions for various values of γ and calculate the mass and baryon charge profile of the corresponding baryons. Using the value γ = 2.55 that has been found to best fit the mesonic spectrum of QCD, we find a value for the baryon mass of 1.19 GeV, significantly more realistic than the value 1.60 GeV computed previously using an SO(4) symmetric ansatz for the instanton.

  3. Holographic spectrograph for space telescope

    NASA Astrophysics Data System (ADS)

    Ditto, Thomas D.; Lysenko, Sergiy; Crenshaw, Melissa

    2013-09-01

    A spectrograph is described which is made with dual Holographic Optical Elements (HOEs) which are identical and parallel to each other. Both optics are collimating transmission HOEs with focal points that are at equal and opposite distances from each other. The identical HOEs are formed by the interference of a plane wave parallel to the grating plane with an off-axis spherical wave originating in the near-field. In playback, a spectrum can be formed from a point source radiator placed at the position of the recording spherical wave. If played back at an arbitrary wavelength other than the recording wavelength, the image exhibits coma. This spectrograph is intended for an unusual configuration where many nearly monochromatic sources of known wavelengths are separately positioned relative to the first HOE. The special application is in a space telescope capable of resolving spectra from habitable planets within 10 pc. HOEs of this type could be fabricated on membrane substrates with a low areal mass and stowable on rolls for insertion into the second Lagrange point. The intended application is for a 50 x 10 meter class primary objective holographic space telescope with 50 x 10 m HOEs in the spectrograph. We present a computer model of the spectrograph.. Experimental results are compared with predictions from theory. A single HOE is shown to perform over a wider bandwidth and is demonstrated.

  4. Holographic holes and differential entropy

    NASA Astrophysics Data System (ADS)

    Headrick, Matthew; Myers, Robert C.; Wien, Jason

    2014-10-01

    Recently it has been shown that the Bekenstein-Hawking entropy formula evaluated on certain closed surfaces in the bulk of a holographic spacetime has an interpretation as the differential entropy of a particular family of intervals (or strips) in the boundary theory [1, 2]. We first extend this construction to bulk surfaces which vary in time. We then give a general proof of the equality between the gravitational entropy and the differential entropy. This proof applies to a broad class of holographic backgrounds possessing a generalized planar symmetry and to certain classes of higher-curvature theories of gravity. To apply this theorem, one can begin with a bulk surface and determine the appropriate family of boundary intervals by considering extremal surfaces tangent to the given surface in the bulk. Alternatively, one can begin with a family of boundary intervals; as we show, the differential entropy then equals the gravitational entropy of a bulk surface that emerges from the intersection of the neighboring entanglement wedges, in a continuum limit.

  5. Holographic opto-fluidic microscopy

    PubMed Central

    Bishara, Waheb; Zhu, Hongying; Ozcan, Aydogan

    2010-01-01

    Over the last decade microfluidics has created a versatile platform that has significantly advanced the ways in which micro-scale organisms and objects are controlled, processed and investigated, by improving the cost, compactness and throughput aspects of analysis. Microfluidics has also expanded into optics to create reconfigurable and flexible optical devices such as reconfigurable lenses, lasers, waveguides, switches, and on-chip microscopes. Here we present a new opto-fluidic microscopy modality, i.e., Holographic Opto-fluidic Microscopy (HOM), based on lensless holographic imaging. This imaging modality complements the miniaturization provided by microfluidics and would allow the integration of microscopy into existing on-chip microfluidic devices with various functionalities. Our imaging modality utilizes partially coherent in-line holography and pixel super-resolution to create high-resolution amplitude and phase images of the objects flowing within micro-fluidic channels, which we demonstrate by imaging C. elegans, Giardia lamblia, and Mulberry pollen. HOM does not involve complicated fabrication processes or precise alignment, nor does it require a highly uniform flow of objects within microfluidic channels. PMID:21197025

  6. Holographic opto-fluidic microscopy.

    PubMed

    Bishara, Waheb; Zhu, Hongying; Ozcan, Aydogan

    2010-12-20

    Over the last decade microfluidics has created a versatile platform that has significantly advanced the ways in which micro-scale organisms and objects are controlled, processed and investigated, by improving the cost, compactness and throughput aspects of analysis. Microfluidics has also expanded into optics to create reconfigurable and flexible optical devices such as reconfigurable lenses, lasers, waveguides, switches, and on-chip microscopes. Here we present a new opto-fluidic microscopy modality, i.e., Holographic Opto-fluidic Microscopy (HOM), based on lensless holographic imaging. This imaging modality complements the miniaturization provided by microfluidics and would allow the integration of microscopy into existing on-chip microfluidic devices with various functionalities. Our imaging modality utilizes partially coherent in-line holography and pixel super-resolution to create high-resolution amplitude and phase images of the objects flowing within micro-fluidic channels, which we demonstrate by imaging C. elegans, Giardia lamblia, and Mulberry pollen. HOM does not involve complicated fabrication processes or precise alignment, nor does it require a highly uniform flow of objects within microfluidic channels. PMID:21197025

  7. Impact of the radiotherapy technique on the correlation between dose-volume histograms of the bladder wall defined on MRI imaging and dose-volume/surface histograms in prostate cancer patients

    NASA Astrophysics Data System (ADS)

    Maggio, Angelo; Carillo, Viviana; Cozzarini, Cesare; Perna, Lucia; Rancati, Tiziana; Valdagni, Riccardo; Gabriele, Pietro; Fiorino, Claudio

    2013-04-01

    The aim of this study was to evaluate the correlation between the ‘true’ absolute and relative dose-volume histograms (DVHs) of the bladder wall, dose-wall histogram (DWH) defined on MRI imaging and other surrogates of bladder dosimetry in prostate cancer patients, planned both with 3D-conformal and intensity-modulated radiation therapy (IMRT) techniques. For 17 prostate cancer patients, previously treated with radical intent, CT and MRI scans were acquired and matched. The contours of bladder walls were drawn by using MRI images. External bladder surfaces were then used to generate artificial bladder walls by performing automatic contractions of 5, 7 and 10 mm. For each patient a 3D conformal radiotherapy (3DCRT) and an IMRT treatment plan was generated with a prescription dose of 77.4 Gy (1.8 Gy/fr) and DVH of the whole bladder of the artificial walls (DVH-5/10) and dose-surface histograms (DSHs) were calculated and compared against the DWH in absolute and relative value, for both treatment planning techniques. A specific software (VODCA v. 4.4.0, MSS Inc.) was used for calculating the dose-volume/surface histogram. Correlation was quantified for selected dose-volume/surface parameters by the Spearman correlation coefficient. The agreement between %DWH and DVH5, DVH7 and DVH10 was found to be very good (maximum average deviations below 2%, SD < 5%): DVH5 showed the best agreement. The correlation was slightly better for absolute (R = 0.80-0.94) compared to relative (R = 0.66-0.92) histograms. The DSH was also found to be highly correlated with the DWH, although slightly higher deviations were generally found. The DVH was not a good surrogate of the DWH (R < 0.7 for most of parameters). When comparing the two treatment techniques, more pronounced differences between relative histograms were seen for IMRT with respect to 3DCRT (p < 0.0001).

  8. NOTE Thyroid volume measurement in external beam radiotherapy patients using CT imaging: correlation with clinical and anthropometric characteristics

    NASA Astrophysics Data System (ADS)

    Veres, C.; Garsi, J. P.; Rubino, C.; Pouzoulet, F.; Bidault, F.; Chavaudra, J.; Bridier, A.; Ricard, M.; Ferreira, I.; Lefkopoulos, D.; de Vathaire, F.; Diallo, I.

    2010-11-01

    The aim of this study is to define criteria for accurate representation of the thyroid in human models used to represent external beam radiotherapy (EBRT) patients and evaluate the relationship between the volume of this organ and clinical and anthropometric characteristics. From CT images, we segmented the thyroid gland and calculated its volume for a population of 188 EBRT patients of both sexes, with ages ranging from 1 to 89 years. To evaluate uncertainties linked to measured volumes, experimental studies on the Livermore anthropomorphic phantom were performed. For our population of EBRT patients, we observed that in children, thyroid volume increased rapidly with age, from about 3 cm3 at 2 years to about 16 cm3 at 20. In adults, the mean thyroid gland volume was 23.5 ± 9 cm3 for males and 17.5 ± 8 cm3 for females. According to anthropometric parameters, the best fit for children was obtained by modeling the log of thyroid volume as a linear function of body surface area (BSA) (p < 0.0001) and age (p = 0.04) and for adults, as a linear function of BSA (p < 0.0001) and gender (p = 0.01). This work enabled us to demonstrate that BSA was the best indicator of thyroid volume for both males and females. These results should be taken into account when modeling the volume of the thyroid in human models used to represent EBRT patients for dosimetry in retrospective studies of the relationship between the estimated dose to the thyroid and long-term follow-up data on EBRT patients.

  9. Free volume of mixed cation borosilicate glass sealants elucidated by positron annihilation lifetime spectroscopy and its correlation with glass properties

    NASA Astrophysics Data System (ADS)

    Ojha, Prasanta K.; Rath, Sangram K.; Sharma, Sandeep K.; Sudarshan, Kathi; Pujari, Pradeep K.; Chongdar, Tapas K.; Gokhale, Nitin M.

    2015-01-01

    The role of La+3/Sr+2 ratios, which is varied from 0.08 to 5.09, on density, molar volume, packing fraction, free volume, thermal and electrical properties in strontium lanthanum aluminoborosilicate based glass sealants intended for solid oxide fuel cell (SOFC) applications is evaluated. The studies reveal expansion of the glass network evident from increasing molar volume and decreasing packing fraction of glasses with progressive La+3 substitutions. The molecular origin of these macroscopic structural features can be accounted for by the free volume parameters measured from positron annihilation lifetime spectroscopy (PALS). The La+3 induced expanded glass networks show increased number of subnanoscopic voids with larger sizes, as revealed from the ortho-positronium (o-Ps) lifetime and its intensity. A remarkably direct correspondence between the molar volume and fractional free volume trend is established with progressive La2O3 substitution in the glasses. The effect of these structural changes on the glass transition temperature, softening temperature, coefficient of thermal expansion, thermal stability as well as electrical conductivity has been studied.

  10. A Mach-Zender Holographic Microscope for Quantifying Bacterial Motility

    NASA Astrophysics Data System (ADS)

    Niraula, B.; Nadeau, J. L.; Serabyn, E.; Wallace, J. K.; Liewer, K.; Kuhn, J.; Graff, E.; Lindensmith, C.

    2014-12-01

    New microscopic techniques have revolutionized cell biology over the past two decades. However, there are still biological processes whose details elude us, especially those involving motility: e.g. feeding behavior of microorganisms in the ocean, or migration of cancer cells to form metastases. Imaging prokaryotes, which range in size from several hundred nm to a few microns, is especially challenging. An emerging technique to address these issues is Digital Holographic Microscopy (DHM). DHM is an imaging technique that uses the interference of light to record and reproduce three-dimensional magnified images of objects. This approach has several advantages over ordinary brightfield microscopy for fieldwork: a larger depth of field, hands-off operation, robustness regarding environmental conditions, and large sampling volumes with quantitative 3D records of motility behavior. Despite these promising features, real-time DHM was thought to be impractical for technological and computational reasons until recently, and there has so far been very limited application of DHM to biology. Most existing instruments are limited in performance by their particular (e.g. in-line, lens-less, phase-shifting) approach to holography. These limitations can be mitigated with an off-axis dual-path configuration. Here we describe the design and implementation of a design for a Mach-Zehnder-type holographic microscope with diffraction-limited lateral resolution, with intended applications in environmental microbiology. We have achieved sub-micron resolution and three-dimensional tracking of prokaryotic and eukaryotic test strains designed to represent different modes and speeds of microbial motility. Prokaryotes are Escherichia coli, Vibrio alginolyticus, and Bacillus subtilis. Each shows a characteristic motility pattern, as we illustrate in holographic videos in sample chambers 0.6 mm in depth. The ability to establish gradients of attractants with bacterial taxis towards the

  11. Walking technipions in a holographic model

    NASA Astrophysics Data System (ADS)

    Kurachi, Masafumi; Matsuzaki, Shinya; Yamawaki, Koichi

    2014-11-01

    We calculate masses of the technipions in the walking technicolor model with the anomalous dimension γm=1 , based on a holographic model which has a naturally light technidilaton ϕ as a composite Higgs with mass mϕ≃125 GeV . The one-family model (with four weak doublets) is taken as a concrete example in such a framework, with the inputs being Fπ=v /2 ≃123 GeV and mϕ≃125 GeV as well as γm=1 . It is shown that technipion masses are enhanced by the large anomalous dimension to typically O (1 ) TeV . We find a correlation between the technipion masses and S(TC ) , the S parameter arising only from the technicolor sector. The current LHC data on the technipion mass limit thus constrains S(TC ) to be not as large as O (1 ), giving a direct constraint on the technicolor model building. This is a new constraint on the technicolor sector alone, quite independent of other sectors connected by the extended-technicolor-type interactions—in sharp contrast to the conventional S parameter constraint from the precision electroweak measurements.

  12. Analyticity and the Holographic S-Matrix

    SciTech Connect

    Fitzpatrick, A.Liam; Kaplan, Jared; /SLAC

    2012-04-03

    We derive a simple relation between the Mellin amplitude for AdS/CFT correlation functions and the bulk S-Matrix in the flat spacetime limit, proving a conjecture of Penedones. As a consequence of the Operator Product Expansion, the Mellin amplitude for any unitary CFT must be a meromorphic function with simple poles on the real axis. This provides a powerful and suggestive handle on the locality vis-a-vis analyticity properties of the S-Matrix. We begin to explore analyticity by showing how the familiar poles and branch cuts of scattering amplitudes arise from the holographic description. For this purpose we compute examples of Mellin amplitudes corresponding to 1-loop and 2-loop Witten diagrams in AdS. We also examine the flat spacetime limit of conformal blocks, implicitly relating the S-Matrix program to the Bootstrap program for CFTs. We use this connection to show how the existence of small black holes in AdS leads to a universal prediction for the conformal block decomposition of the dual CFT.

  13. Unitarity and the Holographic S-Matrix

    SciTech Connect

    Fitzpatrick, A.Liam; Kaplan, Jared; /SLAC

    2012-08-28

    The bulk S-Matrix can be given a non-perturbative definition in terms of the flat space limit of AdS/CFT. We show that the unitarity of the S-Matrix, ie the optical theorem, can be derived by studying the behavior of the OPE and the conformal block decomposition in the flat space limit. When applied to perturbation theory in AdS, this gives a holographic derivation of the cutting rules for Feynman diagrams. To demonstrate these facts we introduce some new techniques for the analysis of conformal field theories. Chief among these is a method for conglomerating local primary operators O{sub 1} and O{sub 2} to extract the contribution of an individual primary O{sub {Delta},{ell}} in their OPE. This provides a method for isolating the contribution of specific conformal blocks which we use to prove an important relation between certain conformal block coefficients and anomalous dimensions. These techniques make essential use of the simplifications that occur when CFT correlators are expressed in terms of a Mellin amplitude.

  14. Holographic zero sound at finite temperature

    NASA Astrophysics Data System (ADS)

    Davison, Richard A.; Starinets, Andrei O.

    2012-01-01

    We use gauge-gravity duality to study the temperature dependence of the zero sound mode and the fundamental matter diffusion mode in the strongly coupled N=4 SU(Nc) supersymmetric Yang-Mills theory with Nf N=2 hypermultiplets in the Nc≫1, Nc≫Nf limit, which is holographically realized via the D3/D7 brane system. In the high density limit μ≫T, three regimes can be identified in the behavior of these modes, analogous to the collisionless quantum, collisionless thermal, and hydrodynamic regimes of a Landau Fermi liquid. The transitions between the three regimes are characterized by the parameters T/μ and (T/μ)2, respectively, and in each of these regimes the modes have a distinctively different temperature and momentum dependence. The collisionless-hydrodynamic transition occurs when the zero sound poles of the density-density correlator in the complex frequency plane collide on the imaginary axis to produce a hydrodynamic diffusion pole. We observe that the properties characteristic of a Landau Fermi-liquid zero sound mode are present in the D3/D7 system despite the atypical T6/μ3 temperature scaling of the specific heat and an apparent lack of a directly identifiable Fermi surface.

  15. Modular digital holographic fringe data processing system

    NASA Technical Reports Server (NTRS)

    Downward, J. G.; Vavra, P. C.; Schebor, F. S.; Vest, C. M.

    1985-01-01

    A software architecture suitable for reducing holographic fringe data into useful engineering data is developed and tested. The results, along with a detailed description of the proposed architecture for a Modular Digital Fringe Analysis System, are presented.

  16. Some applications of holographic interferometry in biomechanics

    NASA Astrophysics Data System (ADS)

    Ebbeni, Jean P. L.

    1992-03-01

    Holographic interferometry is well adapted for the determination of 2D strain fields in osseous structures. The knowledge of those strain fields is important for the understanding of structure behavior such as arthrosis.

  17. Holographic Interferometry--A Laboratory Experiment.

    ERIC Educational Resources Information Center

    de Frutos, A. M.; de la Rosa, M. I.

    1988-01-01

    Explains the problem of analyzing a phase object, separating the contribution due to thickness variations and that due to refractive index variations. Discusses the design of an interferometer and some applications. Provides diagrams and pictures of holographic images. (YP)

  18. Emergence in holographic scenarios for gravity

    NASA Astrophysics Data System (ADS)

    Dieks, Dennis; van Dongen, Jeroen; de Haro, Sebastian

    2015-11-01

    'Holographic' relations between theories have become an important theme in quantum gravity research. These relations entail that a theory without gravity is equivalent to a gravitational theory with an extra spatial dimension. The idea of holography was first proposed in 1993 by Gerard 't Hooft on the basis of his studies of evaporating black holes. Soon afterwards the holographic 'AdS/CFT' duality was introduced, which since has been intensively studied in the string theory community and beyond. Recently, Erik Verlinde has proposed that even Newton's law of gravitation can be related holographically to the 'thermodynamics of information' on screens. We discuss these scenarios, with special attention to the status of the holographic relation in them and to the question of whether they make gravity and spacetime emergent. We conclude that only Verlinde's scheme straightforwardly instantiates emergence. However, assuming a non-standard interpretation of AdS/CFT may create room for the emergence of spacetime and gravity there as well.

  19. Noncontact dimensional measurement system using holographic scanning

    NASA Astrophysics Data System (ADS)

    Sagan, Stephen F.; Rosso, Robert S.; Rowe, David M.

    1997-07-01

    Holographic scanning systems have been used for years in point-of-sale bar code scanners and other low resolution applications. These simple scanning systems could not successfully provide the accuracy and precision required to measure, inspect and control the production of today's high tech optical fibers, medical extrusions and electrical cables. A new class of instruments for the precision measurement of industrial processes has been created by the development of systems with a unique combination of holographic optical elements that can compensate for the wavelength drift in laser diodes, the application of proprietary post-processing algorithms, and the advancements in replication methods to fabricate low cost holographic scanning discs. These systems have improved upon the performance of traditional polygon mirror scanners. This paper presents the optical configuration and design features that have been incorporated into a holographic scanning inspection system that provides higher productivity, increased product quality and lower production costs for many manufacturers.

  20. Meson wave function from holographic approaches

    SciTech Connect

    Vega, Alfredo; Schmidt, Ivan; Branz, Tanja; Gutsche, Thomas; Lyubovitskij, Valery E.

    2010-08-04

    We discuss the light-front wave function for the valence quark state of mesons using the AdS/CFT correspondence. We consider two kinds of wave functions obtained in different holographic Soft-Wall approaches.

  1. G-corrected holographic dark energy model

    NASA Astrophysics Data System (ADS)

    Malekjani, M.; Honari-Jafarpour, M.

    2013-08-01

    Here we investigate the holographic dark energy model in the framework of FRW cosmology where the Newtonian gravitational constant, G, is varying with cosmic time. Using the complementary astronomical data which support the time dependency of G, the evolutionary treatment of EoS parameter and energy density of dark energy model are calculated in the presence of time variation of G. It has been shown that in this case, the phantom regime can be achieved at the present time. We also calculate the evolution of G-corrected deceleration parameter for holographic dark energy model and show that the dependency of G on the comic time can influence on the transition epoch from decelerated expansion to the accelerated phase. Finally we perform the statefinder analysis for G-corrected holographic model and show that this model has a shorter distance from the observational point in s- r plane compare with original holographic dark energy model.

  2. Holographic perfect shuffle permutation element for a miniaturized switching network

    NASA Astrophysics Data System (ADS)

    Kobolla, H.; Schmidt, J.; Gluch, E.; Schwider, J.

    1995-06-01

    A holographic perfect shuffle element with 80 channels for a miniaturized switching network is reported. An array of vertical-cavity, surface-emitting lasers is used as a transmitter. The whole permutation is carried out totally in glass. The 80 channels are permuted within a rectangle with a volume of 3 mm \\times 4 mm \\times 2 mm. Four planes of stacked volume holograms recorded in dichromated gelatin form this perfect shuffle element with an angular spectrum between 7 deg and 35 deg. Changes in the wavelength of the diode lasers to Delta lambda = +/-10 nm can be compensated with this setup. The overall efficiency per channel lies between 40% and 60%. When Fresnel reflections and absorption are taken into account, a transmission per hologram between 78% and 90% is achieved.

  3. Holographic surface gratings in iron-doped lithium niobate

    SciTech Connect

    Sarkisov, S. S.; Curley, M. J.; Kukhtarev, N. V.; Fields, A.; Adamovsky, G.; Smith, C. C.; Moore, L. E.

    2001-08-13

    Surface gratings associated with holographic volume gratings in photorefractive crystals of iron-doped lithium niobate have been studied using diffraction of a reflected probe beam and high-resolution phase-shifted interferometric profilometry. Both techniques show that the surface gratings exist in the form of periodical corrugations of the same period as that of the volume grating. The maximum amplitude of the periodical surface relief measured by both techniques is close to 6.5 nm. We also demonstrated that the periodical electric forces on the surface were capable of assembling polystyrene microspheres along the fringes of the grating. Large amplitude of the periodic electric field (1.6 x 10{sup 4}V/cm) is associated with the photogalvanic effect. {copyright} 2001 American Institute of Physics.

  4. Unified system for holographic measurement in fluid and solid mechanics: use of the system for 3D velocity measurement in fluids through a thick curved window

    NASA Astrophysics Data System (ADS)

    Chan, Victor S. S.; Barnhart, Donald H.; Halliwell, Neil A.; Coupland, Jeremy M.

    1999-10-01

    A new holographic technique has been developed to measure displacement in solid and fluid mechanics. The method uses double exposure holograms of large numerical aperture to record the light scattered from a solid surface or seeding particles that are assumed to follow the fluid motion. Analysis of the resulting hologram is performed in a piece- wise fashion through spatial correlation of the field that passes through a sampling aperture placed in the real image. In this way it is possible to map 3D displacement of an irregular surface or map the movement of seeding throughout an extended volume of fluid. This paper discusses the cancellation of gross aberrations using a phase conjugate holographic optical element to generate a converging reference wave. Seeded flow or solid surfaces recorded with this reference wave geometry can be reconstructed efficiently using a fiber-optic probe. In addition to aberration cancelling the technique allows a method of image shifting to be introduced thus resolving the direction of the flow or surface displacement.

  5. Retro-Nasal Aroma Release Is Correlated with Variations in the In-Mouth Air Cavity Volume after Empty Deglutition

    PubMed Central

    Mishellany-Dutour, Anne; Woda, Alain; Labouré, Hélène; Bourdiol, Pierre; Lachaze, Pauline; Guichard, Elisabeth; Feron, Gilles

    2012-01-01

    We hypothesized that interindividual differences in motor activities during chewing and/or swallowing were determining factors for the transfer of volatile aroma from the in-mouth air cavity (IMAC) toward the olfactory mucosa. In our first experiment, we looked for changes in IMAC volume after saliva deglutition in 12 healthy subjects. The mean IMAC volume was measured after empty deglutition using an acoustic pharyngometer device. Based on the time course of the IMAC volume after swallowing, we discerned two groups of subjects. The first group displayed a small, constant IMAC volume (2.26 mL ±0.62) that corresponded to a high tongue position. The second group displayed a progressive increase in IMAC (from 6.82 mL ±2.37 to 22.82 mL ±3.04) that corresponded to a progressive lowering of the tongue to its resting position. In our second experiment, we investigated the relationship between IMAC volume changes after deglutition and the level of aroma release at the nostril. For this purpose, the release of menthone was measured at the nostril level in 25 subjects who consumed similar amounts of a mint tablet. The subjects were separated into two groups corresponding to two levels of menthone release: high (H) and low (L). The mean volume of IMAC was measured during and after empty deglutition. Group H displayed a small, constant amplitude of IMAC volume change after deglutition, while Group L displayed a progressive increase in IMAC. It is likely that Group H continuously released the aroma through the veloglossal isthmus as the mint was consumed, while Group L trapped the aroma in the oral cavity and then released it into the nasal cavity upon swallowing. These results show that the in vivo aroma release profile in humans depends closely on the different motor patterns at work during empty deglutition. PMID:22815986

  6. Holographic dark energy with varying gravitational constant

    NASA Astrophysics Data System (ADS)

    Jamil, Mubasher; Saridakis, Emmanuel N.; Setare, M. R.

    2009-08-01

    We investigate the holographic dark energy scenario with a varying gravitational constant, in flat and non-flat background geometry. We extract the exact differential equations determining the evolution of the dark energy density-parameter, which include G-variation correction terms. Performing a low-redshift expansion of the dark energy equation of state, we provide the involved parameters as functions of the current density parameters, of the holographic dark energy constant and of the G-variation.

  7. Iron (III)/multiacrylate-based holographic mixtures

    NASA Astrophysics Data System (ADS)

    Lucchetta, D. E.; Nucara, L.; Criante, L.; Simoni, F.; Boni, A.; Xu, Ji-Hua; Bizzarri, R.; Castagna, R.

    2013-11-01

    We propose an holographic mixture, based on a nonconventional photoinitiator mixed with an acrylate monomer, in which high resolution thick holographic gratings are written. The used mixture that preferably works at UV and Blue-visible wavelengths shows many interesting features, such as high post-polymerization transparency, high writing resolution, and high angular selectivity. The information is permanently storable. Standard experimental techniques have been used to characterize the physical properties of the written gratings.

  8. Holographic Optical Elements as Scanning Lidar Telescopes

    NASA Technical Reports Server (NTRS)

    Schwemmer, Geary K.; Rallison, Richard D.; Wilkerson, Thomas D.; Guerra, David V.

    2003-01-01

    We have investigated and developed the use of holographic optical elements (HOE) and holographic transmission gratings for scanning lidar telescopes. By rotating a flat HOE in its own plane with the focal spot on the rotation axis, a very simple and compact conical scanning telescope is possible. We developed and tested transmission and reflection HOES for use with the first three harmonics of Nd:YAG lasers, and designed, built, and tested two lidar systems based on this technology.

  9. Level of holographic noise in interferometry

    NASA Astrophysics Data System (ADS)

    Smolyaninov, Igor I.

    2009-04-01

    The level of holographic noise expected to be observed in interferometric gravitational wave detectors such as GEO600 is reexamined. It is demonstrated that earlier estimates are based on assumed linear diffractive behavior of Planck radiation. Since nonlinear effects, such as self-focusing, are expected to appear at much lower energies, the expected level of holographic noise must be reduced by many orders of magnitude.

  10. Soft wall model for a holographic superconductor

    NASA Astrophysics Data System (ADS)

    Afonin, S. S.; Pusenkov, I. V.

    2016-06-01

    We consider the soft wall holographic approach for description of the high-T_c superconductivity. In comparison with the existing bottom-up holographic superconductors, the proposed approach is more phenomenological and does not describe the superconducting phase transition. On the other hand, technically it is simpler and has more freedom for fitting the conductivity properties of the real high-T_c materials in the superconducting phase. Some examples of emerging models are analyzed.

  11. Humidity and temperature response of photopolymer-based holographic gratings

    NASA Astrophysics Data System (ADS)

    Mikulchyk, Tatsiana; Walshe, James; Cody, Dervil; Martin, Suzanne; Naydenova, Izabela

    2015-05-01

    Holographic sensors have significant potential in various applications ranging from in vitro diagnostics to optical security. They are capable of providing fast, real-time, reversible or irreversible, visual colorimetric or optical readouts. The main challenge in the development of holographic sensors is to improve their selectivity by functionalizing the holographic recording material and achieve a response to a specific analyte. This material should be permeable to the analyte and its properties should change under exposure to the analyte. This work explores the humidity and temperature response of volume phase gratings recorded in photopolymers containing acrylamide and diacetone acrylamide as monomers, and triethanolamine and N-phenylglycine as photoinitiators. Characterization of the humidity response of photopolymer-based gratings in the relative humidity (RH) range of 20-90 % was carried out by measuring the diffraction efficiency of slanted transmission gratings and the position of the maximum intensity in the spectral response of reflection gratings. A strong humidity dependence of the diffraction efficiency of diacetone acrylamide-based transmission gratings was observed at RH=20-90%. The humidity dependence of the spectral response of the reflection gratings showed that photopolymers containing triethanolamine are more hydrophilic than photopolymers containing N-phenylglycine. The temperature response of slanted transmission gratings was investigated in the temperature (T) range of 20-60 °C. Exposure of the photopolymer layers containing triethanolamine to elevated temperature showed that the observed Bragg angle shift was caused by layer shrinkage due to water evaporation. The application of a sealing technique allowed for the observation of the photopolymer layer swelling due to the layer's thermal expansion. The results demonstrate an effective approach to obtaining photopolymer-based gratings with tuneable temperature and humidity sensitivity.

  12. Influence of TFT-LCD pixel structure on holographic representation

    NASA Astrophysics Data System (ADS)

    Wang, Hongjun; Wang, Zhao; Tian, Ailing; Liu, Bingcai

    2008-09-01

    As a new holographic display device, TFT-LCD (Thin Film Transistor Liquid Crystal Displays) is key technical component of holographic representation for easy controlled by computer. With the development of exquisite processing technology, that it instead of the traditional holographic plate become historical necessity and would be the development direction of holographic optics. Based on principles of holography and display character of LCD, the property which the LCD was used as a holographic plate was analyzed. The emphasis on discuss influence of LCD black matrix on holographic representation. First, analyzed on LCD pixel structure, the LCD pixel structure mathematical model was established. LCD was character representation by pixel structure parameters. Then, the influence of LCD pixels structure on holographic representation was analyzed by computer simulation. Meanwhile, the SONY LCX023 was chosen for holographic plate, the He-Ne laser which the wavelength is 0.6328um was holographic representation light source. The holographic representation system was established for test influence of LCD on holographic representation. Final, compared between computer simulations and optical experimental results, the mathematical model of LCD was proved to be true. When aperture ratio is 0.625, the holographic representation wouldn't be distinguished between representation images. At the same time, some useful results was acquired for improve application effects of LCD in holographic representation.

  13. Quantitative investigation of red blood cell three-dimensional geometric and chemical changes in the storage lesion using digital holographic microscopy.

    PubMed

    Jaferzadeh, Keyvan; Moon, Inkyu

    2015-11-01

    Quantitative phase information obtained by digital holographic microscopy (DHM) can provide new insight into the functions and morphology of single red blood cells (RBCs). Since the functionality of a RBC is related to its three-dimensional (3-D) shape, quantitative 3-D geometric changes induced by storage time can help hematologists realize its optimal functionality period. We quantitatively investigate RBC 3-D geometric changes in the storage lesion using DHM. Our experimental results show that the substantial geometric transformation of the biconcave-shaped RBCs to the spherocyte occurs due to RBC storage lesion. This transformation leads to progressive loss of cell surface area, surface-to-volume ratio, and functionality of RBCs. Furthermore, our quantitative analysis shows that there are significant correlations between chemical and morphological properties of RBCs. PMID:26502322

  14. Shrinkage during holographic recording in photopolymer films determined by holographic interferometry.

    PubMed

    Moothanchery, Mohesh; Bavigadda, Viswanath; Toal, Vincent; Naydenova, Izabela

    2013-12-10

    Shrinkage of photopolymer materials is an important factor for their use in holographic data storage and for fabrication of holographic optical elements. Dimensional change in the holographic element leads to a requirement for compensation in the reading angle and/or wavelength. Normally, shrinkage is studied at the end of the polymerization process and no information about the dynamics is obtained. The aim of this study was to use holographic interferometry to measure the shrinkage that occurs during holographic recording of transmission diffraction gratings in acrylamide photopolymer layers. Shrinkage in photopolymer layers can be measured over the whole recorded area by real-time capture of holographic interferograms at regular intervals during holographic recording using a complimentary metal-oxide-semiconductor camera. The optical path length change, and hence the shrinkage, are determined from the captured fringe patterns. Through analysis of the real-time shrinkage curves, it is possible to distinguish two processes that determine the value of shrinkage in the photopolymer layer. These processes are ascribed to monomer polymerization and crosslinking of polymer chains. The dependence of shrinkage of the layers on the conditions of recording such as recording intensity, single or double beam exposure, and the physical properties of the layers, such as thickness, were studied. Higher shrinkage was observed with recordings at lower intensities and in thinner layers. Increased shrinkage was also observed in the case of single beam polymerization in comparison to the case of double beam holographic exposure. PMID:24513896

  15. Optimizing diffraction efficiency for transmission holographic optical elements with HARMAN holographic materials

    NASA Astrophysics Data System (ADS)

    Smith, Steven L.; Harvey, Karen; Richardson, Martin; Blyth, Jeff

    2011-02-01

    HARMAN technology's new holographic emulsions; red sensitive and green sensitive assisted by smaller grain sizes, novel sensitization and coating technology have been shown to achieve high diffraction efficiencies and narrow band reconstruction capabilities. Authors demonstrate processing optimizations and material behavior characteristics for Transmission image Masters as well as Holographic Optical Elements (HOE's).

  16. Holographic Equilibration of Nonrelativistic Plasmas

    NASA Astrophysics Data System (ADS)

    Gürsoy, Umut; Jansen, Aron; Sybesma, Watse; Vandoren, Stefan

    2016-07-01

    We study far-from-equilibrium physics of strongly interacting plasmas at criticality and zero charge density for a wide range of dynamical scaling exponents z in d dimensions using holographic methods. In particular, we consider homogeneous isotropization of asymptotically Lifshitz black branes with full backreaction. We find stable evolution and equilibration times that exhibit small dependence of z and are of the order of the inverse temperature. Performing a quasinormal mode analysis, we find a corresponding narrow range of relaxation times, fully characterized by the fraction z /(d -1 ). For z ≥d -1 , equilibration is overdamped, whereas for z

  17. Coherent Digital Holographic Adaptive Optics

    NASA Astrophysics Data System (ADS)

    Liu, Changgeng

    A new type of adaptive optics (AO) based on the principles of digital holography (DH) is proposed and developed for the use in wide-field and confocal retinal imaging. Digital holographic adaptive optics (DHAO) dispenses with the wavefront sensor and wavefront corrector of the conventional AO system. DH is an emergent imaging technology that gives direct numerical access to the phase of the optical field, thus allowing precise control and manipulation of the optical field. Incorporation of DH in an ophthalmic imaging system can lead to versatile imaging capabilities at substantially reduced complexity and cost of the instrument. A typical conventional AO system includes several critical hardware pieces: spatial light modulator, lenslet array, and a second CCD camera in addition to the camera for imaging. The proposed DHAO system replaces these hardware components with numerical processing for wavefront measurement and compensation of aberration through the principles of DH. (Abstract shortened by UMI.).

  18. Excited Baryons in Holographic QCD

    SciTech Connect

    de Teramond, Guy F.; Brodsky, Stanley J.; /SLAC /Southern Denmark U., CP3-Origins

    2011-11-08

    The light-front holographic QCD approach is used to describe baryon spectroscopy and the systematics of nucleon transition form factors. Baryon spectroscopy and the excitation dynamics of nucleon resonances encoded in the nucleon transition form factors can provide fundamental insight into the strong-coupling dynamics of QCD. The transition from the hard-scattering perturbative domain to the non-perturbative region is sensitive to the detailed dynamics of confined quarks and gluons. Computations of such phenomena from first principles in QCD are clearly very challenging. The most successful theoretical approach thus far has been to quantize QCD on discrete lattices in Euclidean space-time; however, dynamical observables in Minkowski space-time, such as the time-like hadronic form factors are not amenable to Euclidean numerical lattice computations.

  19. Vector fields in holographic cosmology

    NASA Astrophysics Data System (ADS)

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

    2013-11-01

    We extend the holographic formulation of the semiclassical no-boundary wave function (NBWF) to models with Maxwell vector fields. It is shown that the familiar saddle points of the NBWF have a representation in which a regular, Euclidean asymptotic AdS geometry smoothly joins onto a Lorentzian asymptotically de Sitter universe through a complex transition region. The tree level probabilities of Lorentzian histories are fully specified by the action of the AdS region of the saddle points. The scalar and vector matter profiles in this region are complex from an AdS viewpoint, with universal asymptotic phases. The dual description of the semiclassical NBWF thus involves complex deformations of Euclidean CFTs.

  20. Survey of holographic security systems

    NASA Astrophysics Data System (ADS)

    Kontnik, Lewis T.; Lancaster, Ian M.

    1990-04-01

    The counterfeiting of products and financial instruments is a major problem throughout the world today. The dimensions of the problem are growing, accelerated by the expanding availability of production technologies to sophisticated counterfeiters and the increasing capabilities of these technologies. Various optical techniques, including holography, are beingused in efforts to mark authentic products and to distinguish them from copies. Industry is recognizing that the effectiveness of these techniques depends on such factors as the economics of the counterfeiting process and the distribution channels for the products involved, in addition to the performance of the particular optical security technologies used. This paper surveys the nature of the growing counterfeit market place and reviews the utility of holographic optical security systems. In particular, we review the use of holograms on credit cards and other products; and outline certain steps the holography industry should take to promote these application.

  1. Defect CFTs and holographic multiverse

    SciTech Connect

    Fiol, Bartomeu

    2010-07-01

    We investigate some aspects of a recent proposal for a holographic description of the multiverse. Specifically, we focus on the implications on the suggested duality of the fluctuations of a bubble separating two universes with different cosmological constants. We do so by considering a similar problem in a 2+1 CFT with a codimension one defect, obtained by an M5-brane probe embedding in AdS{sub 4} × S{sup 7}, and studying its spectrum of fluctuations. Our results suggest that the kind of behavior required by the spectrum of bubble fluctuations is not likely to take place in defect CFTs with an AdS dual, although it might be possible if the defect supports a non-unitary theory.

  2. Holographic viscosity of fundamental matter.

    PubMed

    Mateos, David; Myers, Robert C; Thomson, Rowan M

    2007-03-01

    A holographic dual of a finite-temperature SU(Nc) gauge theory with a small number of flavors Nf or =1/4pi. Given the known results for the entropy density, the contribution of the fundamental matter eta fund is therefore enhanced at strong 't Hooft coupling lambda; for example, eta fund approximately lambda NcNfT3 in four dimensions. Other transport coefficients are analogously enhanced. These results hold with or without a baryon number chemical potential. PMID:17358523

  3. String junctions and holographic interfaces

    SciTech Connect

    Chiodaroli, Marco; Gutperle, Michael; Hung, Ling-Yan; Krym, Darya

    2011-01-15

    In this paper we study half-BPS type IIB supergravity solutions with multiple AdS{sub 3}xS{sup 3}xM{sub 4} asymptotic regions, where M{sub 4} is either T{sup 4} or K{sub 3}. These solutions were first constructed in [M. Chiodaroli, M. Gutperle, and D. Krym, J. High Energy Phys. 02 (2010) 066.] and have geometries given by the warped product of AdS{sub 2}xS{sup 2}xM{sub 4} over {Sigma}, where {Sigma} is a Riemann surface. We show that the holographic boundary has the structure of a star graph, i.e. n half-lines joined at a point. The attractor mechanism and the relation of the solutions to junctions of self-dual strings in six-dimensional supergravity are discussed. The solutions of [M. Chiodaroli, M. Gutperle, and D. Krym, J. High Energy Phys. 02 (2010) 066.] are constructed introducing two meromorphic and two harmonic functions defined on {Sigma}. We focus our analysis on solutions corresponding to junctions of three different conformal field theories and show that the conditions for having a solution charged only under Ramond-Ramond three-form fields reduce to relations involving the positions of the poles and the residues of the relevant harmonic and meromorphic functions. The degeneration limit in which some of the poles collide is analyzed in detail. Finally, we calculate the holographic boundary entropy for a junction of three CFTs and obtain a simple expression in terms of poles and residues.

  4. Neural correlates of the ‘good life’: eudaimonic well-being is associated with insular cortex volume

    PubMed Central

    Kanai, Ryota; Rees, Geraint; Bates, Timothy C.

    2014-01-01

    Eudaimonic well-being reflects traits concerned with personal growth, self-acceptance, purpose in life and autonomy (among others) and is a substantial predictor of life events, including health. Although interest in the aetiology of eudaimonic well-being has blossomed in recent years, little is known of the underlying neural substrates of this construct. To address this gap in our knowledge, here we examined whether regional gray matter (GM) volume was associated with eudaimonic well-being. Structural magnetic resonance images from 70 young, healthy adults who also completed Ryff’s 42-item measure of the six core facets of eudaimonia, were analysed with voxel-based morphometry techniques. We found that eudaimonic well-being was positively associated with right insular cortex GM volume. This association was also reflected in three of the sub-scales of eudaimonia: personal growth, positive relations and purpose in life. Positive relations also showed a significant association with left insula volume. No other significant associations were observed, although personal growth was marginally associated with left insula, and purpose in life exhibited a marginally significant negative association with middle temporal gyrus GM volume. These findings are the first to our knowledge linking eudaimonic well-being with regional brain structure. PMID:23512932

  5. Dyslexia and Voxel-Based Morphometry: Correlations between Five Behavioural Measures of Dyslexia and Gray and White Matter Volumes

    ERIC Educational Resources Information Center

    Tamboer, Peter; Scholte, H. Steven; Vorst, Harrie C. M.

    2015-01-01

    In voxel-based morphometry studies of dyslexia, the relation between causal theories of dyslexia and gray matter (GM) and white matter (WM) volume alterations is still under debate. Some alterations are consistently reported, but others failed to reach significance. We investigated GM alterations in a large sample of Dutch students (37 dyslexics…

  6. Dose-Volume Parameters of the Corpora Cavernosa Do Not Correlate With Erectile Dysfunction After External Beam Radiotherapy for Prostate Cancer: Results From a Dose-Escalation Trial

    SciTech Connect

    Wielen, Gerard J. van der Hoogeman, Mischa S.; Dohle, Gert R.; Putten, Wim L.J. van; Incrocci, Luca

    2008-07-01

    Purpose: To analyze the correlation between dose-volume parameters of the corpora cavernosa and erectile dysfunction (ED) after external beam radiotherapy (EBRT) for prostate cancer. Methods and Materials: Between June 1997 and February 2003, a randomized dose-escalation trial comparing 68 Gy and 78 Gy was conducted. Patients at our institute were asked to participate in an additional part of the trial evaluating sexual function. After exclusion of patients with less than 2 years of follow-up, ED at baseline, or treatment with hormonal therapy, 96 patients were eligible. The proximal corpora cavernosa (crura), the superiormost 1-cm segment of the crura, and the penile bulb were contoured on the planning computed tomography scan and dose-volume parameters were calculated. Results: Two years after EBRT, 35 of the 96 patients had developed ED. No statistically significant correlations between ED 2 years after EBRT and dose-volume parameters of the crura, the superiormost 1-cm segment of the crura, or the penile bulb were found. The few patients using potency aids typically indicated to have ED. Conclusion: No correlation was found between ED after EBRT for prostate cancer and radiation dose to the crura or penile bulb. The present study is the largest study evaluating the correlation between ED and radiation dose to the corpora cavernosa after EBRT for prostate cancer. Until there is clear evidence that sparing the penile bulb or crura will reduce ED after EBRT, we advise to be careful in sparing these structures, especially when this involves reducing treatment margins.

  7. Development of integral holographic motion pictures

    NASA Astrophysics Data System (ADS)

    Alexander, P.

    1995-02-01

    In 1985 Anne-Marie Christakis selected me to make the first pulse holographic feature-fiction movie. Up to that time, the process had only been used for laboratory tests. The running time for the movie was to be 1 minute 20 seconds. Apparently quite long compared with previous tests, but an extremely short time in which to tell a story. I chose the characters of Beauty and the Beast. A lot of time was spent in preparatory work: triple distilling the scenario to get it down to 80 seconds; paintings and masks, and I extracted the music from a suite I had already written in medieval style. The movie was made in 1986 in the laboratory of Professeur Smigielsky, which was located in the Franco-German Defense Research Establishment, at St. Louis in France. Prof. Smigielsky's staff operated all the equipment and Anne-Marie Christakis coordinated everything, as she had done throughout the project. As soon as we arrived at the laboratory, we were told not to look beyond a certain angle towards the laser, otherwise we could be blinded for life. With all that dangerous power however, it was only possible to illuminate a volume for the set of half a meter wide by half a meter deep by one third of a meter high. Such a set gives real meaning to the expression `cramp one's style.' The layout used was, in principle, the same as for making a simple hologram. A pulsed YAG laser was used and each pulse was synchronized with a new frame to be exposed in the camera. When the movie was finished, it was not very bright, and one had to look through a small aperture to view it.

  8. Apoptotic markers in cultured fibroblasts correlate with brain metabolites and regional brain volume in antipsychotic-naive first-episode schizophrenia and healthy controls

    PubMed Central

    Batalla, A; Bargalló, N; Gassó, P; Molina, O; Pareto, D; Mas, S; Roca, J M; Bernardo, M; Lafuente, A; Parellada, E

    2015-01-01

    Cultured fibroblasts from first-episode schizophrenia patients (FES) have shown increased susceptibility to apoptosis, which may be related to glutamate dysfunction and progressive neuroanatomical changes. Here we determine whether apoptotic markers obtained from cultured fibroblasts in FES and controls correlate with changes in brain glutamate and N-acetylaspartate (NAA) and regional brain volumes. Eleven antipsychotic-naive FES and seven age- and gender-matched controls underwent 3-Tesla magnetic resonance imaging scanning. Glutamate plus glutamine (Glx) and NAA levels were measured in the anterior cingulate (AC) and the left thalamus (LT). Hallmarks of apoptotic susceptibility (caspase-3-baseline activity, phosphatidylserine externalization and chromatin condensation) were measured in fibroblast cultures obtained from skin biopsies after inducing apoptosis with staurosporine (STS) at doses of 0.25 and 0.5 μM. Apoptotic biomarkers were correlated to brain metabolites and regional brain volume. FES and controls showed a negative correlation in the AC between Glx levels and percentages of cells with condensed chromatin (CC) after both apoptosis inductions (STS 0.5 μM: r=−0.90; P=0.001; STS 0.25 μM: r=−0.73; P=0.003), and between NAA and cells with CC (STS 0.5 μM induction r=−0.76; P=0.002; STS 0.25 μM r=−0.62; P=0.01). In addition, we found a negative correlation between percentages of cells with CC and regional brain volume in the right supratemporal cortex and post-central region (STS 0.25 and 0.5 μM; P<0.05 family-wise error corrected (FWEc)). We reveal for the first time that peripheral markers of apoptotic susceptibility may correlate with brain metabolites, Glx and NAA, and regional brain volume in FES and controls, which is consistent with the neuroprogressive theories around the onset of the schizophrenia illness. PMID:26305477

  9. Holographic data storage: rebirthing a commercialization effort

    NASA Astrophysics Data System (ADS)

    Anderson, Ken; Ayres, Mark; Sissom, Brad; Askham, Fred

    2014-02-01

    The realization of a commercial holographic data storage device has remained elusive for many decades. The most recent efforts were by InPhase Technologies between 2001 and 2009 resulting in 52 functioning prototypes capable of 300GB/disk and 20MB/s transfer rates. Despite being the world's first fully functional holographic drives, the primary competitor to holographic archive storage at that time, LTO, had already achieved 800GB and 120MB/in 2008; and by 2010, LTO had achieved 1.5TB and 140MB/s. This left InPhase at a competitive disadvantage to LTO archive solutions despite other strengths such as robustness, random access, and longer-term archive lifetime. Looking into the future, holographic data storage must be highly competitive with tape in three critical areas: cost/TB, capacity/footprint, and transfer rate. If this can be achieved, holographic data storage would become a superior solution given the low latencies and overall robustness to propel it into being the archive storage front-runner. New technology advancements by Akonia Holographics have enabled the potential for ultra-high capacity holographic storage devices that are capable of world record bit densities of over 2Tbit/in2, 200-300MB/s transfer rates, and a media cost less than $10/TB in the next 5 years. A demonstration platform based on these new advances has been designed and is currently being built by Akonia to progressively demonstrate bit densities of 2Tb/in2, 4Tb/in2, and 8Tb/in2 over the next year.

  10. The Compact and Inexpensive "Arrowhead" Setup for Holographic Interferometry

    ERIC Educational Resources Information Center

    Ladera, Celso L.; Donoso, Guillermo

    2011-01-01

    Hologram recording and holographic interferometry are intrinsically sensitive to phase changes, and therefore both are easily perturbed by minuscule optical path perturbations. It is therefore very convenient to bank on holographic setups with a reduced number of optical components. Here we present a compact off-axis holographic setup that…

  11. The evaluation of carotid intima-media thickness and mean platelet volume values and correlation with cardiac functions in obese children

    PubMed Central

    Özkan, Esra Akyüz; Khosroshahi, Hashem E; Serin, Halil İbrahim; Özdemir, Zeynep Tuba; Kılıç, Mahmut; Ekim, Meral; Geçit, U Aliye; Domur, Esra

    2015-01-01

    Background: Obesity is associated with many risk factors, such as hyperlipidemia, hyperinsulinemia, hypertension and leads to early atherosclerosis. The aim of this study was to investigate the relation of the mean platelet volume (MPV) and the carotid intima media thickness (CIMT) on cardiac functions among obese children. Materials and Methods: Sixty obese children, with body mass index percentile were >95% and forty eight healthy controls were enrolled in the study. Triglyceride, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, alanine aminotransferase (ALT), aspartate aminotransferase (AST), thyroid function tests, hemoglobin, white blood cell, MPV and insulin resistance were evaluated. CIMT was measured by using high-resolution ultrasound and echocardiography was performed to all individuals. Results: MPV and CIMT values were found significantly higher in obese children than controls. There was positive correlation between CIMT and age, body surface area (BSA), systolic and diastolic blood pressure, left ventricular meridional end-systolic wall stress (ESWSm), myocardial fiber stress (MFS), stroke volume (SV) and insulin and negative correlation with left ventricle end-systolic elastance by single beat technique (Ees(sb)) and arterial elastance (Ea). There was no correlation between LVM, cardiac risk profiles and CIMT. Multiple stepwise regression analyses revealed that ESWSm (β=0.337, P=0.049) was only independent factor on CIMT. MPV values showed negative correlation with ALT, AST, Free T4, thyroid stimulating hormone and positive correlation with age and BSA. Conclusion: Current study showed that obesity has an independent impact on CIMT and MPV values in children. Increased CIMT in obese children leads significant increase in ESWSm and decrease in Ea and Ees(sb). PMID:26885242

  12. Novel computational approach for studying ph effects, excluded volume and ion-ion correlations in electrical double layers around polyelectrolytes and nanoparticles

    NASA Astrophysics Data System (ADS)

    Ovanesyan, Zaven

    Highly charged cylindrical and spherical objects (macroions) are probably the simplest structures for modeling nucleic acids, proteins and nanoparticles. Their ubiquitous presence within biophysical systems ensures that Coulomb forces are among the most important interactions that regulate the behavior of these systems. In these systems, ions position themselves in a strongly correlated manner near the surface of a macroion and form electrical double layers (EDLs). These EDLs play an important role in many biophysical and biochemical processes. For instance, the macroion's net charge can change due to the binding of many multivalent ions to its surface. Thus, proper description of EDLs near the surface of a macroion may reveal a counter-intuitive charge inversion behavior, which can generate attraction between like-charged objects. This is relevant for the variety of fields such as self-assembly of DNA and RNA folding, as well as for protein aggregation and neurodegenerative diseases. Certainly, the key factors that contribute to these phenomena cannot be properly understood without an accurate solvation model. With recent advancements in computer technologies, the possibility to use computational tools for fundamental understanding of the role of EDLs around biomolecules and nanoparticles on their physical and chemical properties is becoming more feasible. Establishing the impact of the excluded volume and ion-ion correlations, ionic strength and pH of the electrolyte on the EDL around biomolecules and nanoparticles, and how changes in these properties consequently affect the Zeta potential and surface charge density are still not well understood. Thus, modeling and understanding the role of these properties on EDLs will provide more insights on the stability, adsorption, binding and function of biomolecules and nanoparticles. Existing mean-field theories such as Poisson Boltzmann (PB) often neglect the ion-ion correlations, solvent and ion excluded volume effects

  13. Novel computational approach for studying ph effects, excluded volume and ion-ion correlations in electrical double layers around polyelectrolytes and nanoparticles

    NASA Astrophysics Data System (ADS)

    Ovanesyan, Zaven

    Highly charged cylindrical and spherical objects (macroions) are probably the simplest structures for modeling nucleic acids, proteins and nanoparticles. Their ubiquitous presence within biophysical systems ensures that Coulomb forces are among the most important interactions that regulate the behavior of these systems. In these systems, ions position themselves in a strongly correlated manner near the surface of a macroion and form electrical double layers (EDLs). These EDLs play an important role in many biophysical and biochemical processes. For instance, the macroion's net charge can change due to the binding of many multivalent ions to its surface. Thus, proper description of EDLs near the surface of a macroion may reveal a counter-intuitive charge inversion behavior, which can generate attraction between like-charged objects. This is relevant for the variety of fields such as self-assembly of DNA and RNA folding, as well as for protein aggregation and neurodegenerative diseases. Certainly, the key factors that contribute to these phenomena cannot be properly understood without an accurate solvation model. With recent advancements in computer technologies, the possibility to use computational tools for fundamental understanding of the role of EDLs around biomolecules and nanoparticles on their physical and chemical properties is becoming more feasible. Establishing the impact of the excluded volume and ion-ion correlations, ionic strength and pH of the electrolyte on the EDL around biomolecules and nanoparticles, and how changes in these properties consequently affect the Zeta potential and surface charge density are still not well understood. Thus, modeling and understanding the role of these properties on EDLs will provide more insights on the stability, adsorption, binding and function of biomolecules and nanoparticles. Existing mean-field theories such as Poisson Boltzmann (PB) often neglect the ion-ion correlations, solvent and ion excluded volume effects

  14. Holographic fluorescence microscopy with incoherent digital holographic adaptive optics.

    PubMed

    Jang, Changwon; Kim, Jonghyun; Clark, David C; Lee, Seungjae; Lee, Byoungho; Kim, Myung K

    2015-01-01

    Introduction of adaptive optics technology into astronomy and ophthalmology has made great contributions in these fields, allowing one to recover images blurred by atmospheric turbulence or aberrations of the eye. Similar adaptive optics improvement in microscopic imaging is also of interest to researchers using various techniques. Current technology of adaptive optics typically contains three key elements: a wavefront sensor, wavefront corrector, and controller. These hardware elements tend to be bulky, expensive, and limited in resolution, involving, for example, lenslet arrays for sensing or multiactuator deformable mirrors for correcting. We have previously introduced an alternate approach based on unique capabilities of digital holography, namely direct access to the phase profile of an optical field and the ability to numerically manipulate the phase profile. We have also demonstrated that direct access and compensation of the phase profile are possible not only with conventional coherent digital holography, but also with a new type of digital holography using incoherent light: selfinterference incoherent digital holography (SIDH). The SIDH generates a complex—i.e., amplitude plus phase—hologram from one or several interferograms acquired with incoherent light, such as LEDs, lamps, sunlight, or fluorescence. The complex point spread function can be measured using guide star illumination and it allows deterministic deconvolution of the full-field image. We present experimental demonstration of aberration compensation in holographic fluorescence microscopy using SIDH. Adaptive optics by SIDH provides new tools for improved cellular fluorescence microscopy through intact tissue layers or other types of aberrant media. PMID:26146767

  15. Didactical Holographic Exhibit Including Holo TV (holographic Television)

    NASA Astrophysics Data System (ADS)

    Lunazzi, José J.; Magalhães, Daniel S. F.; Rivera, Noemí I. R.

    2008-04-01

    Our Institute of Physics exposes since 1980 didactical exhibitions of holography in Brazil where nice holograms are shown altogether with basic experiments of geometric and wave optics. This experiments lead to the understanding of the phenomenon of images of an ample way. Thousands of people have been present at them, in their majority of the Universidade Estadual de Campinas, where since 2002 they have taken the format of a course without formal evaluation. This way the exhibition has been divided in four modules, in each one of them are shown different holograms, experiments of optics and applications of diffractive images with white light developed in the Institute of Physics. The sequence of the learning through the modules begins with the geometric optics, later we explain the wave optics and finally holography. The phenomenon of the diffraction in daily elements is shown experimentally from the beginning. As well as the application of the holographic screens in white light: the television images that appear in front of the screen and the spectator can try to experience the reality illusion. Put something so exclusive (that only exists in the laboratory) to the public is a way to approximate the persons to an investigation in course. The vision of images that seem to be of holograms, but in movement, and size of until a square meter completes this exhibition of an exclusive way in the world.

  16. Holographic fluorescence microscopy with incoherent digital holographic adaptive optics

    NASA Astrophysics Data System (ADS)

    Jang, Changwon; Kim, Jonghyun; Clark, David C.; Lee, Seungjae; Lee, Byoungho; Kim, Myung K.

    2015-11-01

    Introduction of adaptive optics technology into astronomy and ophthalmology has made great contributions in these fields, allowing one to recover images blurred by atmospheric turbulence or aberrations of the eye. Similar adaptive optics improvement in microscopic imaging is also of interest to researchers using various techniques. Current technology of adaptive optics typically contains three key elements: a wavefront sensor, wavefront corrector, and controller. These hardware elements tend to be bulky, expensive, and limited in resolution, involving, for example, lenslet arrays for sensing or multiactuator deformable mirrors for correcting. We have previously introduced an alternate approach based on unique capabilities of digital holography, namely direct access to the phase profile of an optical field and the ability to numerically manipulate the phase profile. We have also demonstrated that direct access and compensation of the phase profile are possible not only with conventional coherent digital holography, but also with a new type of digital holography using incoherent light: self­interference incoherent digital holography (SIDH). The SIDH generates a complex-i.e., amplitude plus phase-hologram from one or several interferograms acquired with incoherent light, such as LEDs, lamps, sunlight, or fluorescence. The complex point spread function can be measured using guide star illumination and it allows deterministic deconvolution of the full-field image. We present experimental demonstration of aberration compensation in holographic fluorescence microscopy using SIDH. Adaptive optics by SIDH provides new tools for improved cellular fluorescence microscopy through intact tissue layers or other types of aberrant media.

  17. The energy performance of prototype holographic glazings

    NASA Astrophysics Data System (ADS)

    Papamichael, K.; Beltran, L.; Furler, R.; Lee, E. S.; Selkowitz, S.; Rubin, M.

    1993-02-01

    We report on the simulation of the energy performance of prototype holographic glazings in commercial office buildings in a California climate. These prototype glazings, installed above conventional side windows, are designed to diffract the transmitted solar radiation and reflect it off the ceiling, providing adequate daylight illumination for typical office tasks up to 10m from the window. In this study, we experimentally determined a comprehensive set of solar-optical properties and characterized the contribution of the prototype holographic glazings to workplane illuminance in a scale model of a typical office space. We then used the scale model measurements to simulate the energy performance of the holographic glazings over the course of an entire year for four window orientations (North, East, South and West) for the inland Los Angeles climate, using the DOE-2.lD building energy analysis computer program. The results of our experimental analyses indicate that these prototype holographic glazings diffract only a small fraction of the incident light. The results of this study indicate that these prototype holographic glazings will not save energy in commercial office buildings. Their performance is very similar to that of clear glass, which, through side windows, cannot efficiently illuminate more than a 4-6 m depth of a building's perimeter, because the cooling penalties due to solar heat gain are greater than the electric lighting savings due to daylighting.

  18. Phase structures of holographic screen thermodynamics

    NASA Astrophysics Data System (ADS)

    Jiang, Wei-Jian; Chen, Yi-Xin; Li, Jian-Long

    2014-07-01

    Holographic screens are the generalization of the event horizon of a black hole in entropic force scheme, which are defined by setting Newton potential ϕ constant, i.e. e2ϕ = c = const. We demonstrate that the integrated first law of thermodynamics is equivalent to the (r-r) component of Einstein equations, so that we strengthen the correspondence between thermodynamics and gravity. We show that there are not only the first law of thermodynamics, but also kinds of phase transitions of holographic screens. These phase transitions are characterized by the discontinuity of their heat capacities. In (n+1)-dimensional Reissner-Nordström-anti-de Sitter (RN-AdS) spacetime, we analyze three kinds of phase transitions, which are of the holographic screens with Q = 0 (charge), constant Φ (electrostatic potential) and nonzero constant Q. In the Q = 0 case, only the holographic screens with 0≤c<1 can undergo phase transition. In the constant Φ case, the constraints become as 0<= c+16˜ {Γ }2Φ 2<1, where ˜ {Γ } is a dimensional-dependent parameter. By verifying the Ehrenfest equations, we show that the phase transitions in this case are all second order phase transitions. In the constant Q case, there might be two, or one, or no phase transitions of holographic screens, depending on the values of Q and c.

  19. Correlation of physical properties with molecular structure for some dicyclic hydrocarbons having high thermal-energy release per unit volume

    NASA Technical Reports Server (NTRS)

    Wise, P H; Serijan, K T; Goodman, I A

    1951-01-01

    As part of a program to study the correlation between molecular structure and physical properties of high-density hydrocarbons, the net heats of combustion, melting points, boiling points, densities, and kinematic viscosities of some hydrocarbons in the 2-n-alkylbiphenyl, 1,1-diphenylalkane, diphenylalkane, 1,1-dicyclohexylalkane, and dicyclohexylalkane series are presented.

  20. Holographic Particle Image Velocimetry and its Application in Engine Development

    NASA Astrophysics Data System (ADS)

    Coupland, J. M.; Garner, C. P.; Alcock, R. D.; Halliwell, N. A.

    2006-07-01

    This paper reviews Holographic Particle Image Velocimetry (HPIV) as a means to make three-component velocity measurements throughout a three-dimensional flow-field of interest. A simplified treatment of three-dimensional scalar wave propagation is outlined and subsequently used to illustrate the principles of complex correlation analysis. It is shown that this type of analysis provides the three-dimensional correlation of the propagating, monochromatic fields recorded by the hologram. A similar approach is used to analyse the Object Conjugate Reconstruction (OCR) technique to resolve directional ambiguity by introducing an artificial image shift to the reconstructed particle images. An example of how these methods are used together to measure the instantaneous flow fields within a motored Diesel engine is then described.

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

    NASA Astrophysics Data System (ADS)

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

    1996-12-01

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

  2. Data correlation and analysis of arc tunnel and wind tunnel tests of RSI joints and gaps. Volume 1: Technical report

    NASA Technical Reports Server (NTRS)

    Christensen, H. E.; Kipp, H. W.

    1974-01-01

    Heat transfer data measured in gaps typical of those under consideration for joints in space shuttle reusable surface insulation protection systems have been assimilated, analyzed and correlated. The data were obtained in four NASA facilities. Several types of gaps were investigated with emphasis on simple butt joints. Gap widths ranged from 0.07 to 0.7 cm and depths ranged from 1 to 6 cm. Laminar, transitional and turbulent boundary layer flows over the gap opening were investigated. Three-dimensional heating variations were observed within gaps in the absence of external flow pressure gradients. Heat transfer correlation equations were obtained for several of the tests. Thermal protection system performance with and without gaps was compared for a representative shuttle entry trajectory.

  3. Dynamic holographic endoscopy--ex vivo investigations of malignant tumors in the human stomach.

    PubMed

    Avenhaus, Wolfgang; Kemper, Björn; Knoche, Sabine; Domagk, Dirk; Poremba, Christopher; von Bally, Gert; Domschke, Wolfram

    2005-01-01

    Laser holographic interferometry is based on the superimposition of the holograms of different motional states of an object on a single holographic storing medium. Using a combination of holographic interferometry and endoscopic imaging, we tried to detect areas of focally disturbed tissue elasticity in gastric cancer preparations. By connecting a mobile electronic speckle pattern interferometry (ESPI) camera system (light source: double frequency Nd:YAG laser, lambda = 532 nm) to different types of endoscopes, ex vivo experiments were performed on ten formalin fixed human stomachs, nine containing adenocarcinomas and one with a gastric lymphoma. Linking the endoscopic ESPI camera complex to a fast image processing system, the method of double pulse exposure image subtraction was applied at a video frame rate of 12.5 Hz. Speckle correlation patterns and corresponding phase difference distributions resulting from gastric wall deformation by gentle touch with a guide wire were analyzed. Tumor-free gastric areas showed high-contrast concentric fringes around the point of stimulation. In contrast, fringe patterns and filtered phase difference distributions corresponding to the areas of malignancy in all the cases were characterized by largely parallel lines, indicating that stimulation of rigid tumor tissue primarily led to tilting. Our ex vivo investigations of malignant gastric tumors show that the application of dynamic holographic endoscopy makes it possible to distinguish areas of malignancy from surrounding healthy tissue based on the differences in tissue elasticity. PMID:15726298

  4. Data correlation and analysis of arc tunnel and wind tunnel tests of RSI joints and gaps. Volume 2: Data base

    NASA Technical Reports Server (NTRS)

    Christensen, H. E.; Kipp, H. W.

    1974-01-01

    Wind tunnel tests were conducted to determine the aerodynamic heating created by gaps in the reusable surface insulation (RSI) thermal protection system (TPS) for the space shuttle. The effects of various parameters of the RSI on convective heating characteristics are described. The wind tunnel tests provided a data base for accurate assessment of gap heating. Analysis and correlation of the data provide methods for predicting heating in the RSI gaps on the space shuttle.

  5. Spherical roller bearing analysis. SKF computer program SPHERBEAN. Volume 3: Program correlation with full scale hardware tests

    NASA Technical Reports Server (NTRS)

    Kleckner, R. J.; Rosenlieb, J. W.; Dyba, G.

    1980-01-01

    The results of a series of full scale hardware tests comparing predictions of the SPHERBEAN computer program with measured data are presented. The SPHERBEAN program predicts the thermomechanical performance characteristics of high speed lubricated double row spherical roller bearings. The degree of correlation between performance predicted by SPHERBEAN and measured data is demonstrated. Experimental and calculated performance data is compared over a range in speed up to 19,400 rpm (0.8 MDN) under pure radial, pure axial, and combined loads.

  6. Digital holographic-based cancellable biometric for personal authentication

    NASA Astrophysics Data System (ADS)

    Verma, Gaurav; Sinha, Aloka

    2016-05-01

    In this paper, we propose a new digital holographic-based cancellable biometric scheme for personal authentication and verification. The realization of cancellable biometric is presented by using an optoelectronic experimental approach, in which an optically recorded hologram of the fingerprint of a person is numerically reconstructed. Each reconstructed feature has its own perspective, which is utilized to generate user-specific fingerprint features by using a feature-extraction process. New representations of the user-specific fingerprint features can be obtained from the same hologram, by changing the reconstruction distance (d) by an amount Δd between the recording plane and the reconstruction plane. This parameter is the key to make the cancellable user-specific fingerprint features using a digital holographic technique, which allows us to choose different reconstruction distances when reissuing the user-specific fingerprint features in the event of compromise. We have shown theoretically that each user-specific fingerprint feature has a unique identity with a high discrimination ability, and the chances of a match between them are minimal. In this aspect, a recognition system has also been demonstrated using the fingerprint biometric of the enrolled person at a particular reconstruction distance. For the performance evaluation of a fingerprint recognition system—the false acceptance ratio, the false rejection ratio and the equal error rate are calculated using correlation. The obtained results show good discrimination ability between the genuine and the impostor populations with the highest recognition rate of 98.23%.

  7. Light-Front Holographic QCD

    SciTech Connect

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

    2012-02-16

    The relation between the hadronic short-distance constituent quark and gluon particle limit and the long-range confining domain is yet one of the most challenging aspects of particle physics due to the strong coupling nature of Quantum Chromodynamics, the fundamental theory of the strong interactions. The central question is how one can compute hadronic properties from first principles; i.e., directly from the QCD Lagrangian. The most successful theoretical approach thus far has been to quantize QCD on discrete lattices in Euclidean space-time. Lattice numerical results follow from computation of frame-dependent moments of distributions in Euclidean space and dynamical observables in Minkowski spacetime, such as the time-like hadronic form factors, are not amenable to Euclidean lattice computations. The Dyson-Schwinger methods have led to many important insights, such as the infrared fixed point behavior of the strong coupling constant, but in practice, the analyses are limited to ladder approximation in Landau gauge. Baryon spectroscopy and the excitation dynamics of nucleon resonances encoded in the nucleon transition form factors can provide fundamental insight into the strong-coupling dynamics of QCD. New theoretical tools are thus of primary interest for the interpretation of the results expected at the new mass scale and kinematic regions accessible to the JLab 12 GeV Upgrade Project. The AdS/CFT correspondence between gravity or string theory on a higher-dimensional anti-de Sitter (AdS) space and conformal field theories in physical space-time has led to a semiclassical approximation for strongly-coupled QCD, which provides physical insights into its nonperturbative dynamics. The correspondence is holographic in the sense that it determines a duality between theories in different number of space-time dimensions. This geometric approach leads in fact to a simple analytical and phenomenologically compelling nonperturbative approximation to the full light

  8. A holographic quantum Hall ferromagnet

    NASA Astrophysics Data System (ADS)

    Kristjansen, C.; Pourhasan, R.; Semenoff, G. W.

    2014-02-01

    A detailed numerical study of a recent proposal for exotic states of the D3-probe D5 brane system with charge density and an external magnetic field is presented. The state has a large number of coincident D5 branes blowing up to a D7 brane in the presence of the worldvolume electric and magnetic fields which are necessary to construct the holographic state. Numerical solutions have shown that these states can compete with the the previously known chiral symmetry breaking and maximally symmetric phases of the D3-D5 system. Moreover, at integer filling fractions, they are incompressible with integer quantized Hall conductivities. In the dual superconformal defect field theory, these solutions correspond to states which break the chiral and global flavor symmetries spontaneously. The region of the temperature-density plane where the D7 brane has lower energy than the other known D5 brane solutions is identified. A hypothesis for the structure of states with filling fraction and Hall conductivity greater than one is made and tested by numerical computation. A parallel with the quantum Hall ferromagnetism or magnetic catalysis phenomenon which is observed in graphene is drawn. As well as demonstrating that the phenomenon can exist in a strongly coupled system, this work makes a number of predictions of symmetry breaking patterns and phase transitions for such systems.

  9. Holographic confinement in inhomogeneous backgrounds

    NASA Astrophysics Data System (ADS)

    Marolf, Donald; Wien, Jason

    2016-08-01

    As noted by Witten, compactifying a d-dimensional holographic CFT on an S 1 gives a class of ( d - 1)-dimensional confining theories with gravity duals. The proto-typical bulk solution dual to the ground state is a double Wick rotation of the AdS d+1 Schwarzschild black hole known as the AdS soliton. We generalize such examples by allowing slow variations in the size of the S 1, and thus in the confinement scale. Coefficients governing the second order response of the system are computed for 3 ≤ d ≤ 8 using a derivative expansion closely related to the fluid-gravity correspondence. The primary physical results are that i) gauge-theory flux tubes tend to align orthogonal to gradients and along the eigenvector of the Hessian with the lowest eigenvalue, ii) flux tubes aligned orthogonal to gradients are attracted to gradients for d ≤ 6 but repelled by gradients for d ≥ 7, iii) flux tubes are repelled by regions where the second derivative along the tube is large and positive but are attracted to regions where the eigenvalues of the Hessian are large and positive in directions orthogonal to the tube, and iv) for d > 3, inhomogeneities act to raise the total energy of the confining vacuum above its zeroth order value.

  10. Holographic entanglement beyond classical gravity

    NASA Astrophysics Data System (ADS)

    Barrella, Taylor; Dong, Xi; Hartnoll, Sean A.; Martin, Victoria L.

    2013-09-01

    The Rényi entropies and entanglement entropy of 1+1 CFTs with gravity duals can be computed by explicit construction of the bulk spacetimes dual to branched covers of the boundary geometry. At the classical level in the bulk this has recently been shown to reproduce the conjectured Ryu-Takayanagi formula for the holographic entanglement entropy. We study the one-loop bulk corrections to this formula. The functional determinants in the bulk geometries are given by a sum over certain words of generators of the Schottky group of the branched cover. For the case of two disjoint intervals on a line we obtain analytic answers for the one-loop entanglement entropy in an expansion in small cross-ratio. These reproduce and go beyond anticipated universal terms that are not visible classically in the bulk. We also consider the case of a single interval on a circle at finite temperature. At high temperatures we show that the one-loop contributions introduce expected finite size corrections to the entanglement entropy that are not present classically. At low temperatures, the one-loop corrections capture the mixed nature of the density matrix, also not visible classically below the Hawking-Page temperature.

  11. Holographic bounds and Higgs inflation

    NASA Astrophysics Data System (ADS)

    Horvat, R.

    2011-05-01

    In a recently proposed scenario for primordial inflation, where the Standard Model (SM) Higgs boson plays a role of the inflation field, an effective field theory (EFT) approach is the most convenient for working out the consequences of breaking of perturbative unitarity, caused by the strong coupling of the Higgs field to the Ricci scalar. The domain of validity of the EFT approach is given by the ultraviolet (UV) cutoff, which, roughly speaking, should always exceed the Hubble parameter in the course of inflation. On the other hand, applying the trusted principles of quantum gravity to a local EFT demands that it should only be used to describe states in a region larger than their corresponding Schwarschild radius, manifesting thus a sort of UV/IR correspondence. We consider both constraints on EFT, to ascertain which models of the SM Higgs inflation are able to simultaneously comply with them. We also show that if the gravitational coupling evolves with the scale factor, the holographic constraint can be alleviated significantly with minimal set of canonical assumptions, by forcing the said coupling to be asymptotically free.

  12. Exact holographic mapping in free fermion systems

    NASA Astrophysics Data System (ADS)

    Lee, Ching Hua; Qi, Xiao-Liang

    2016-01-01

    In this paper, we perform a detailed analysis of the exact holographic mapping first introduced in arXiv:1309.6282, which was proposed as an explicit example of holographic duality between quantum many-body systems and gravitational theories. We obtain analytic results for free fermion systems that not only confirm previous numerical results, but also elucidate the exact relationships between the various physical properties of the bulk and boundary systems. These analytic results allow us to study the asymptotic properties that are difficult to probe numerically, such as the near-horizon regime of the black-hole geometry. We shall also explore a few interesting but hitherto unexplored bulk geometries, such as that corresponding to a boundary critical fermion with a nontrivial dynamical critical exponent. Our analytic framework also allows us to study the holographic mapping of some of these boundary theories in dimensions 2+1 or higher.

  13. Holographic trace anomaly and local renormalization group

    NASA Astrophysics Data System (ADS)

    Rajagopal, Srivatsan; Stergiou, Andreas; Zhu, Yechao

    2015-11-01

    The Hamilton-Jacobi method in holography has produced important results both at a renormalization group (RG) fixed point and away from it. In this paper we use the Hamilton-Jacobi method to compute the holographic trace anomaly for four- and six-dimensional boundary conformal field theories (CFTs), assuming higher-derivative gravity and interactions of scalar fields in the bulk. The scalar field contributions to the anomaly appear in CFTs with exactly marginal operators. Moving away from the fixed point, we show that the Hamilton-Jacobi formalism provides a deep connection between the holographic and the local RG. We derive the local RG equation holographically, and verify explicitly that it satisfies Weyl consistency conditions stemming from the commutativity of Weyl scalings. We also consider massive scalar fields in the bulk corresponding to boundary relevant operators, and comment on their effects to the local RG equation.

  14. Collapse and revival in holographic quenches

    NASA Astrophysics Data System (ADS)

    da Silva, Emilia; Lopez, Esperanza; Mas, Javier; Serantes, Alexandre

    2015-04-01

    We study holographic models related to global quantum quenches in finite size systems. The holographic set up describes naturally a CFT, which we consider on a circle and a sphere. The enhanced symmetry of the conformal group on the circle motivates us to compare the evolution in both cases. Depending on the initial conditions, the dual geometry exhibits oscillations that we holographically interpret as revivals of the initial field theory state. On the sphere, this only happens when the energy density created by the quench is small compared to the system size. However on the circle considerably larger energy densities are compatible with revivals. Two different timescales emerge in this latter case. A collapse time, when the system appears to have dephased, and the revival time, when after rephasing the initial state is partially recovered. The ratio of these two times depends upon the initial conditions in a similar way to what is observed in some experimental setups exhibiting collapse and revivals.

  15. Holographic optical system for aberration corrections in laser Doppler velocimetry

    NASA Technical Reports Server (NTRS)

    Kim, R. C.; Case, S. K.; Schock, H. J.

    1985-01-01

    An optical system containing multifaceted holographic optical elements (HOEs) has been developed to correct for aberrations introduced by nonflat windows in laser Doppler velocimetry. The multifacet aberration correction approach makes it possible to record on one plate many sets of adjacent HOEs that address different measurement volume locations. By using 5-mm-diameter facets, it is practical to place 10-20 sets of holograms on one 10 x 12.5-cm plate, so that the procedure of moving the entire optical system to examine different locations may not be necessary. The holograms are recorded in dichromated gelatin and therefore are nonabsorptive and suitable for use with high-power argon laser beams. Low f-number optics coupled with a 90-percent efficient distortion-correcting hologram in the collection side of the system yield high optical efficiency.

  16. Holographic memory module with ultra-high capacity and throughput

    SciTech Connect

    Vladimir A. Markov, Ph.D.

    2000-06-04

    High capacity, high transfer rate, random access memory systems are needed to archive and distribute the tremendous volume of digital information being generated, for example, the human genome mapping and online libraries. The development of multi-gigabit per second networks underscores the need for next-generation archival memory systems. During Phase I we conducted the theoretical analysis and accomplished experimental tests that validated the key aspects of the ultra-high density holographic data storage module with high transfer rate. We also inspected the secure nature of the encoding method and estimated the performance of full-scale system. Two basic architectures were considered, allowing for reversible compact solid-state configuration with limited capacity, and very large capacity write once read many memory system.

  17. Three-dimensional spatiotemporal focusing of holographic patterns

    PubMed Central

    Hernandez, Oscar; Papagiakoumou, Eirini; Tanese, Dimitrii; Fidelin, Kevin; Wyart, Claire; Emiliani, Valentina

    2016-01-01

    Two-photon excitation with temporally focused pulses can be combined with phase-modulation approaches, such as computer-generated holography and generalized phase contrast, to efficiently distribute light into two-dimensional, axially confined, user-defined shapes. Adding lens-phase modulations to 2D-phase holograms enables remote axial pattern displacement as well as simultaneous pattern generation in multiple distinct planes. However, the axial confinement linearly degrades with lateral shape area in previous reports where axially shifted holographic shapes were not temporally focused. Here we report an optical system using two spatial light modulators to independently control transverse- and axial-target light distribution. This approach enables simultaneous axial translation of single or multiple spatiotemporally focused patterns across the sample volume while achieving the axial confinement of temporal focusing. We use the system's capability to photoconvert tens of Kaede-expressing neurons with single-cell resolution in live zebrafish larvae. PMID:27306044

  18. Three-dimensional spatiotemporal focusing of holographic patterns.

    PubMed

    Hernandez, Oscar; Papagiakoumou, Eirini; Tanese, Dimitrii; Fidelin, Kevin; Wyart, Claire; Emiliani, Valentina

    2016-01-01

    Two-photon excitation with temporally focused pulses can be combined with phase-modulation approaches, such as computer-generated holography and generalized phase contrast, to efficiently distribute light into two-dimensional, axially confined, user-defined shapes. Adding lens-phase modulations to 2D-phase holograms enables remote axial pattern displacement as well as simultaneous pattern generation in multiple distinct planes. However, the axial confinement linearly degrades with lateral shape area in previous reports where axially shifted holographic shapes were not temporally focused. Here we report an optical system using two spatial light modulators to independently control transverse- and axial-target light distribution. This approach enables simultaneous axial translation of single or multiple spatiotemporally focused patterns across the sample volume while achieving the axial confinement of temporal focusing. We use the system's capability to photoconvert tens of Kaede-expressing neurons with single-cell resolution in live zebrafish larvae. PMID:27306044

  19. Three-dimensional spatiotemporal focusing of holographic patterns

    NASA Astrophysics Data System (ADS)

    Hernandez, Oscar; Papagiakoumou, Eirini; Tanese, Dimitrii; Fidelin, Kevin; Wyart, Claire; Emiliani, Valentina

    2016-06-01

    Two-photon excitation with temporally focused pulses can be combined with phase-modulation approaches, such as computer-generated holography and generalized phase contrast, to efficiently distribute light into two-dimensional, axially confined, user-defined shapes. Adding lens-phase modulations to 2D-phase holograms enables remote axial pattern displacement as well as simultaneous pattern generation in multiple distinct planes. However, the axial confinement linearly degrades with lateral shape area in previous reports where axially shifted holographic shapes were not temporally focused. Here we report an optical system using two spatial light modulators to independently control transverse- and axial-target light distribution. This approach enables simultaneous axial translation of single or multiple spatiotemporally focused patterns across the sample volume while achieving the axial confinement of temporal focusing. We use the system's capability to photoconvert tens of Kaede-expressing neurons with single-cell resolution in live zebrafish larvae.

  20. Multiplexed holographic memory by use of fiber bundle referencing

    NASA Astrophysics Data System (ADS)

    Zhang, Jiasen; Aruga, Tadashi

    2005-04-01

    We propose a volume holographic storage technique, in which a fiber bundle is used to guide the reference beam. Multiplexing is implemented by changing the incident direction of the laser beam upon the fiber bundle in the reference arm. In the technique, we make the system more compact by using a wedge prism to change the direction of the laser beam. This method has a large accessible angular scanning range and a large geometric storage bandwidth. Multiple images are stored in a LiNbO3:Fe crystal with an angular separation of 0.05° between successive holograms using a wedge prism with a deviation angle of 8°. This method is useful as a new image storage technique because of its compactness and simplicity.

  1. Likelihood-based error correction for holographic storage systems

    NASA Astrophysics Data System (ADS)

    Neifeld, Mark A.; Chou, Wu-Chun

    1999-11-01

    We consider a volume holographic memory (VHM) system that is corrupted by interpixel interference (IPI) and detector noise. We compare hard-decision Reed-Solomon (RS) decoding with both hard- and soft-decision algorithms for 2D array decoding. RS codes are shown to provide larger VHM storage capacity and density as compared with array codes when hard-decision methods are employed. A new likelihood-based soft-decision algorithm for 2D array decoding is described. The new decoding algorithm is motivated by iterative turbo-decoding methods and is capable of incorporating a priori knowledge of the corrupting IPI channel during decoding. The new algorithm is shown to offer VHM capacity and density performance superior to hard-decision RS methods.

  2. Simulating the energy performance of holographic glazings

    NASA Astrophysics Data System (ADS)

    Papamichael, K.; Beltran, L.; Furler, Reto; Lee, E. S.; Selkowitz, Steven E.; Rubin, Michael

    1994-09-01

    The light diffraction properties of holographic diffractive structures present an opportunity to improve the daylight performance in side-lit office spaces by redirecting and reflecting sunlight off the ceiling, providing adequate daylight illumination up to 30 ft (9.14 m) from the window wall. Prior studies of prototypical holographic glazings, installed above conventional `view' windows, have shown increased daylight levels over a deeper perimeter area than clear glass, for selected sun positions. In this study, we report on the simulation of the energy performance of prototypical holographic glazings assuming a commercial office building in the inland Los Angeles climate. The simulation of the energy performance involved determination of both luminous and thermal performance. Since the optical complexity of holographic glazings prevented the use of conventional algorithms for the simulation of their luminous performance, we used a newly developed method that combines experimentally determined directional workplane illuminance coefficients with computer-based analytical routines to determine a comprehensive set of daylight factors for many sun positions. These daylight factors were then used within the DOE-2.1D energy simulation program to determine hourly daylight and energy performance over the course of an entire year for four window orientations. Since the prototypical holographic diffractive structures considered in this study were applied on single pane clear glass, we also simulated the performance of hypothetical glazings, assuming the daylight performance of the prototype holographic glazings and the thermal performance of double-pane and low-e glazings. Finally, we addressed various design and implementation issues towards potential performance improvement.

  3. Viscosity of concentrated solutions and of human erythrocyte cytoplasm determined from NMR measurement of molecular correlation times. The dependence of viscosity on cell volume.

    PubMed

    Endre, Z H; Kuchel, P W

    1986-08-01

    Metabolically active human erythrocytes were incubated with [alpha-13C]glycine which led to the specific enrichment of intracellular glutathione. The cells were then studied using 13C-NMR in which the longitudinal relaxation times (T1) and nuclear Overhauser enhancements of the free glycine and glutathione were measured. The T1 values of labelled glycine were also determined in various-concentration solutions of bovine serum albumin and glycerol and also of the natural abundance 13C of glycerol in glycerol solutions. From the T1 estimates the rotational correlation time (tau r) was calculated using a formula based on a model of an isotropic spherical rotor or that of a symmetrical ellipsoidal rotor; for glycine the differences in estimates of tau r obtained using the two models were not significant. From the correlation times and by use of the Stokes-Einstein equations viscosity and translational diffusion coefficients were calculated; thus comment can be made on the likelihood of diffusion control of certain enzyme-catalysed reactions in the erythrocyte. Bulk viscosities of the erythrocyte cytoplasm and the above-mentioned solutions were measured using Ostwald capillary viscometry. Large differences existed between the latter viscosity estimates and those based upon NMR-T1 measurements. We derived an equation from the theory of the viscosity of concentrated solutions which contains two phenomenological interaction parameters, a 'shape' factor and a 'volume' factor; it was fitted to data relating to the concentration dependence of viscosity measured by both methods. We showed, by using the equation and interaction-parameter estimates for a particular probe molecule in a particular solution, that it was possible to correlate NMR viscosity and bulk viscosity; in other words, given an estimate of the bulk viscosity, it was possible to calculate the NMR 'micro' viscosity or vice versa. However, the values of the interaction parameters depend upon the relative sizes of

  4. Holographic fluorescence microscopy with incoherent digital holographic adaptive optics

    NASA Astrophysics Data System (ADS)

    Jang, Changwon; Kim, Jonghyun; Clark, David C.; Lee, Byoungho; Kim, Myung K.

    2015-03-01

    Introduction of adaptive optics technology into astronomy and ophthalmology has made great contributions in these fields, allowing one to recover images blurred by atmospheric turbulence or aberrations of the eye. Similar adaptive optics improvement in microscopic imaging is also of interest to researchers using various techniques. Current technology of adaptive optics typically contains three key elements: wavefront sensor, wavefront corrector and controller. These hardware elements tend to be bulky, expensive, and limited in resolution, involving, e.g., lenslet arrays for sensing or multi-acuator deformable mirrors for correcting. We have previously introduced an alternate approach to adaptive optics based on unique capabilities of digital holography, namely direct access to the phase profile of an optical field and the ability to numerically manipulate the phase profile. We have also demonstrated that direct access and compensation of the phase profile is possible not only with the conventional coherent type of digital holography, but also with a new type of digital holography using incoherent light: self-interference incoherent digital holography (SIDH). The SIDH generates complex - i.e. amplitude plus phase - hologram from one or several interferograms acquired with incoherent light, such as LEDs, lamps, sunlight, or fluorescence. The complex point spread function can be measured using a guide star illumination and it allows deterministic deconvolution of the full-field image. We present experimental demonstration of aberration compensation in holographic fluorescence microscopy using SIDH. The adaptive optics by SIDH provides new tools for improved cellular fluorescence microscopy through intact tissue layers or other types of aberrant media.

  5. Correlation of Stroke Volume Measurement between Sonosite Portable Echocardiogram and Edwards Flotrac Sensor-Vigileo Monitor in an Intensive Care Unit

    PubMed Central

    Behnia, Mehrdad; Powell, Sherry; Fallen, Linda; Tamaddon, Houman; Behnia, Masud

    2013-01-01

    Purpose Stroke volume (SV) is a parameter that is being recognized as an endpoint in fluid resuscitation algorithms. Its role is now being realized as an important variable in hemodynamic assessment in various clinical scenarios such as septic and cardiogenic shocks. Direct measurement of stroke volume (SV) and its novel corollary, stroke volume variation (SVV) derived by proprietary software, are preferred over mean cardiac output (CO) measurements because they render a more accurate reflection of hemodynamic status independent of heart rate. Flotrac-Vigileo monitor (FTV) (Edwards Lifesciences, Irvine, CA, USA) is a system that uses a complex algorithm analyzing arterial waveform to calculate SV, SVV, and CO. We assessed the feasibility of obtaining SV measurements with a portable echocardiogram and validated its accuracy with the FTV system in mechanically ventilated patients in our intensive care unit (ICU). Furthermore, we emphasized the importance of hemodynamic measurements and familiarity with critical care echocardiography for the intensivists. Methods Ten patients who were on mechanical ventilation were studied. A femoral arterial line was connected to the FTV system monitoring SV and CO. A portable echocardiogram (M-Turbo; Sonosite, Bothell, WA) was used to measure SV. CO was calculated by multiplying SV by heart rate. No patient had arrhythmia. We used biplane Simpson’s method of discs to calculate SV in which subtraction of end-systolic volume from end-diastolic volume yields the SV. Results The comparison of simultaneous SV and CO measurements by echocardiography with FTV showed a strong correlation between the 2. (For SV, y = 0.9545x + 3.3, R2 = 0.98 and for CO, y = 0.9104x + 7.7074, R2 = 0.97). Conclusions In our small cohort, the SV and CO measured by a portable echocardiogram (Sonosite M-Turbo) appears to be closely correlated with their respective values measured by FTV. Portable echocardiography is a reliable noninvasive tool for the

  6. Entropy-Corrected Holographic Dark Energy

    NASA Astrophysics Data System (ADS)

    Wei, Hao

    2009-10-01

    The holographic dark energy (HDE) is now an interesting candidate of dark energy, which has been studied extensively in the literature. In the derivation of HDE, the black hole entropy plays an important role. In fact, the entropy-area relation can be modified due to loop quantum gravity or other reasons. With the modified entropy-area relation, we propose the so-called “entropy-corrected holographic dark energy" (ECHDE) in the present work. We consider many aspects of ECHDE and find some interesting results. In addition, we briefly consider the so-called “entropy-corrected agegraphic dark energy" (ECADE).

  7. Interacting holographic dark energy with logarithmic correction

    SciTech Connect

    Jamil, Mubasher; Farooq, M. Umar E-mail: mufarooq@yahoo.com

    2010-03-01

    The holographic dark energy (HDE) is considered to be the most promising candidate of dark energy. Its definition is motivated from the entropy-area relation which depends on the theory of gravity under consideration. Recently a new definition of HDE is proposed with the help of quantum corrections to the entropy-area relation in the setup of loop quantum cosmology. Employing this new definition, we investigate the model of interacting dark energy and derive its effective equation of state. Finally we establish a correspondence between generalized Chaplygin gas and entropy-corrected holographic dark energy.

  8. Holographic cold nuclear matter and neutron star

    NASA Astrophysics Data System (ADS)

    Ghoroku, Kazuo; Kubo, Kouki; Tachibana, Motoi; Toyoda, Fumihiko

    2014-04-01

    We have previously found a new phase of cold nuclear matter based on a holographic gauge theory, where baryons are introduced as instanton gas in the probe D8//lineD8 branes. In our model, we could obtain the equation of state (EOS) of our nuclear matter by introducing Fermi momentum. Then, here we apply this model to the neutron star and study its mass and radius by solving the Tolman-Oppenheimer-Volkoff (TOV) equations in terms of the EOS given here. We give some comments for our holographic model from a viewpoint of the other field theoretical approaches.

  9. A computer test of holographic flavour dynamics

    NASA Astrophysics Data System (ADS)

    Filev, Veselin G.; O'Connor, Denjoe

    2016-05-01

    We perform computer simulations of the Berkooz-Douglas (BD) matrix model, holographically dual to the D0/D4-brane intersection. We generate the fundamental condensate versus bare mass curve of the theory both holographically and from simulations of the BD model. Our studies show excellent agreement of the two approaches in the deconfined phase of the theory and significant deviations in the confined phase. We argue the discrepancy in the confined phase is explained by the embedding of the D4-brane which yields stronger α' corrections to the condensate in this phase.

  10. Holographic superconductors from the massive gravity

    NASA Astrophysics Data System (ADS)

    Zeng, Hua Bi; Wu, Jian-Pin

    2014-08-01

    A holographic superconductor is constructed in the background of a massive gravity theory. In the normal state without condensation, the conductivity exhibits a Drude peak that approaches a delta function in the massless gravity limit as studied by David Vegh. In the superconducting state, besides the infinite dc conductivity, the ac conductivity has Drude behavior at low frequency followed by a power-law fall. These results are in agreement with that found earlier by Horowitz and Santos, who studied a holographic superconductor with an implicit periodic potential beyond the probe limit. The results also agree with measurements on some cuprates.

  11. Digital holographic Michelson interferometer for nanometrology

    NASA Astrophysics Data System (ADS)

    Sevrygin, Alexander A.; Korotkov, V. I.; Pulkin, S. A.; Tursunov, I. M.; Venediktov, D. V.; Venediktov, V. Yu.; Volkov, O. V.

    2014-11-01

    The paper considers the dynamic holographic interferometry schemes with amplification (multiplication) of holographic fringes and with correction for distortions, imposed by the interferometer scheme elements. The use of digital microscope and of the matrix light modulator with direct addressing provides the completely digital closed-loop performance of the overall system for real-time evaluation of nano-scale objects size. Considered schemes were verified in the laboratory experiment, using the Michelson micro-interferometer, equipped by the USB-microscope and digital holography stage, equipped by the Holoeye spatial light modulator.

  12. Improved performance in coaxial holographic data recording.

    PubMed

    Tanaka, Kenji; Hara, Masaaki; Tokuyama, Kazutatsu; Hirooka, Kazuyuki; Ishioka, Koji; Fukumoto, Atsushi; Watanabe, Kenjiro

    2007-11-26

    We describe a coaxial holographic recording system for achieving high recording density. We implement several techniques, such as an objective lens with high numerical aperture (NA), high capacity page data format, a random binary phase mask, and an optical noise reduction element. Our system successfully realizes a hologram recording/retrieving at a low diffraction efficiency less than 2.0 x 10(-3) and achieves a raw data density of 180 Gbit/in.(2), thus demonstrating the potential of a coaxial holographic system for high-density optical storage systems. PMID:19550907

  13. Low holographic concentration effects on CIGS

    NASA Astrophysics Data System (ADS)

    Castillo, Jose E.; Russo, Juan M.; Zhang, Deming; Kostuk, Raymond K.; Rosenberg, Glenn A.

    2010-08-01

    We present the results of combining copper indium gallium (di)selenide (CIGS) photovoltaic cells with holographic planar concentrating film over a broad range of illumination levels. The film, originally designed for silicon bifacial solar applications worked well with the CIGS cells. The Voc, cell efficiency and fill factor reached full operating values at lower light levels; with a significant boost in performance being recorded. The holographic regions of the concentrator act as extended heat transfer surfaces, allowing the CIGS cells to operate at lower operational temperatures than they normally would in a traditional PV application.

  14. Holographic interferometry: A user`s guide

    SciTech Connect

    Griggs, D.

    1993-10-01

    This manual describes the procedures and components necessary to produce a holographic interferogram of a flow field in the Sandia National Laboratories hypersonic wind tunnel. In contrast to classical interferometry, holographic interferometry records the amplitude and phase distribution of a lightwave passing through the flow field at some instant of time. This information can then be reconstructed outside the wind tunnel for visual analysis and digital processing, yielding precise characterizations of aerodynamic phenomena. The reconstruction and subsequent hologram image storage process is discussed, with particular attention paid to the digital image processor and the data reduction technique.

  15. Holographic entropy increases in quadratic curvature gravity

    NASA Astrophysics Data System (ADS)

    Bhattacharjee, Srijit; Sarkar, Sudipta; Wall, Aron C.

    2015-09-01

    Standard methods for calculating the black hole entropy beyond general relativity are ambiguous when the horizon is nonstationary. We fix these ambiguities in all quadratic curvature gravity theories, by demanding that the entropy be increasing at every time, for linear perturbations to a stationary black hole. Our result matches with the entropy formula found previously in holographic entanglement entropy calculations. We explicitly calculate the entropy increase for Vaidya-like solutions in Ricci-tensor gravity to show that (unlike the Wald entropy) the holographic entropy obeys a second law.

  16. Shape of mesons in holographic QCD

    SciTech Connect

    Torabian, Mahdi; Yee, Ho-Ung

    2009-10-15

    Based on the expectation that the constituent quark model may capture the right physics in the large N limit, we point out that the orbital angular momentum of the quark-antiquark pair inside light mesons of low spins in the constituent quark model may provide a clue for the holographic dual string model of large N QCD. Our discussion, relying on a few suggestive assumptions, leads to a necessity of world-sheet fermions in the bulk of dual strings that can incorporate intrinsic spins of fundamental QCD degrees of freedom. We also comment on the interesting issue of the size of mesons in holographic QCD.

  17. General properties of holographic entanglement entropy

    NASA Astrophysics Data System (ADS)

    Headrick, Matthew

    2014-03-01

    The Ryu-Takayanagi formula implies many general properties of entanglement entropies in holographic theories. We review the known properties, such as continuity, strong subadditivity, and monogamy of mutual information, and fill in gaps in some of the previously-published proofs. We also add a few new properties, including: properties of the map from boundary regions to bulk regions implied by the RT formula, such as monotonicity; conditions under which subadditivity-type inequalities are saturated; and an inequality concerning reflection-symmetric states. We attempt to draw lessons from these properties about the structure of the reduced density matrix in holographic theories.

  18. Real-time holographic surveillance system

    DOEpatents

    Collins, H.D.; McMakin, D.L.; Hall, T.E.; Gribble, R.P.

    1995-10-03

    A holographic surveillance system is disclosed including means for generating electromagnetic waves; means for transmitting the electromagnetic waves toward a target at a plurality of predetermined positions in space; means for receiving and converting electromagnetic waves reflected from the target to electrical signals at a plurality of predetermined positions in space; means for processing the electrical signals to obtain signals corresponding to a holographic reconstruction of the target; and means for displaying the processed information to determine nature of the target. The means for processing the electrical signals includes means for converting analog signals to digital signals followed by a computer means to apply a backward wave algorithm. 21 figs.

  19. Real-time holographic surveillance system

    DOEpatents

    Collins, H. Dale; McMakin, Douglas L.; Hall, Thomas E.; Gribble, R. Parks

    1995-01-01

    A holographic surveillance system including means for generating electromagnetic waves; means for transmitting the electromagnetic waves toward a target at a plurality of predetermined positions in space; means for receiving and converting electromagnetic waves reflected from the target to electrical signals at a plurality of predetermined positions in space; means for processing the electrical signals to obtain signals corresponding to a holographic reconstruction of the target; and means for displaying the processed information to determine nature of the target. The means for processing the electrical signals includes means for converting analog signals to digital signals followed by a computer means to apply a backward wave algorithm.

  20. Real-time wideband holographic surveillance system

    DOEpatents

    Sheen, D.M.; Collins, H.D.; Hall, T.E.; McMakin, D.L.; Gribble, R.P.; Severtsen, R.H.; Prince, J.M.; Reid, L.D.

    1996-09-17

    A wideband holographic surveillance system including a transceiver for generating a plurality of electromagnetic waves; antenna for transmitting the electromagnetic waves toward a target at a plurality of predetermined positions in space; the transceiver also receiving and converting electromagnetic waves reflected from the target to electrical signals at a plurality of predetermined positions in space; a computer for processing the electrical signals to obtain signals corresponding to a holographic reconstruction of the target; and a display for displaying the processed information to determine nature of the target. The computer has instructions to apply a three dimensional backward wave algorithm. 28 figs.