Fingerprint identification by use of a volume holographic optical correlator
NASA Astrophysics Data System (ADS)
Lee, Seung-Hyun; Yi, Sang-Yi; Kim, Eun-Soo
1999-03-01
We propose an optical correlator system using volume hologram for database of matched filter. Optical correlator has high speed and parallel processing characteristics of optics. Matched filters are recorded into a volume hologram that can store data with high density, transfer them with high speed, and select a randomly chosen data element. The multiple reference images of database are prerecorded in a photorefractive crystal in the form of Fourier transform images, simply by passing the image displayed in a spatial light modulator through a Fourier transform lens. The angular multiplexing method for multiple holograms of database is achieved by controlling the reference directions with a step motor. Experimental results show that the proposed system can be used for fingerprint recognition.
Applications of phase masks in volume holographic data storage system and correlators
Wei Ren; Qiang Ma; Liangcai Cao; Qingsheng He; Guofan Jin
2008-01-01
Effects of phase masks, used in content-addressable volume holographic data storage system, on the spectrum modulation, image reconstruction, and content search capability are analyzed. We have investigated the influence of varying the pixel structure of phase masks on Fourier-transform holographic recording and reconstruction errors. The effect on reconstruction errors of using a (0, pi) two-level phase mask is studied. The
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.
Monopole correlations in holographically flavored liquids
NASA Astrophysics Data System (ADS)
Iqbal, Nabil
2015-05-01
Many-body systems with a conserved U (1 ) current in (2 +1 ) dimensions may be probed by weakly gauging this current and studying correlation functions of magnetic monopole operators in the resulting dynamical gauge theory. We study such monopole correlations in holographic liquids with fundamental flavor, where the monopole operator is dual to a magnetically charged particle in the bulk. In charge-gapped phases, the monopole operator is expected to condense. We show that this condensation is holographically dual to the capping off of the bulk flavor brane and compute the monopole condensate. We argue that from the lower-dimensional point of view, this may be understood as a simple example of confinement of a gauge field in the bulk. In a compressible finite-density phase, we present a novel calculation of the monopole correlation in space and time: the correlation is power law in time but Gaussian in space due to interaction with the background charge density.
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.
Volume holographic pupils in ray, wave, statistical optics, and Wigner space
Oh, Se Baek
2009-01-01
This thesis explores various aspects of the volume holographic pupils to better understand and implement multi-dimensional imaging. A full description and applications of volume holographic pupils are presented in ray, ...
Volume polarization holographic recording in thick photopolymer for optical memory.
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
Doped photopolymers for volume holographic applications
NASA Astrophysics Data System (ADS)
Lin, Shiuan Huei; Lin, June-Hua; Hsiao, Yi-Nan; Hsu, Ken Y.
2006-08-01
We fabricate two phenanthrenequinone-doped copolymers which can improve the holographic recording characteristics of phenanthrenequinone-doped poly(methyl-methacrylate) (PQ/PMMA) photopolymer. In these materials, the polymer matrix of PQ/PMMA is modified to be copolymers, which composed of either poly(methyl-methacrylate-co -trimethylolpropane-triacrylate) or poly(methyl-methacrylate-co-acrylic acid 2-phenoxyethyl ester), respectively. With the chemical analyses of these materials before and after light exposure, we investigate the physical mechanism of the holographic recording in those copolymer samples. In addition, the holographic characteristics of different samples, including dynamic range and sensitivity, have been measured. These experimental results demonstrate that modification of the monomers is an efficient method to improve the material properties.
High-resolution volume holographic profilometry using the Viterbi algorithm
NASA Astrophysics Data System (ADS)
Sun, Wenyang; Sinha, Arnab; Barbastathis, George; Neifeld, Mark A.
2005-06-01
We use the Viterbi decoding algorithm to resolve depth features beyond the nominal resolution limit of a volume holographic profilometry system. The formulation treats the truncated point-spread function as an intersymbol interference and uses surface constraints and transition constraints to reduce the computational complexity. A factor-of-5 improvement in resolution was obtained in our experimental demonstration.
Euclidean correlation functions in a holographic model of QCD
Schaefer, T. [Department of Physics, North Carolina State University, Raleigh, NC 27695 (United States)
2008-06-15
We compute Euclidean coordinate space correlation functions in a holographic model of QCD. We concentrate, in particular, on channels that are related to the U(1){sub A} problem, the flavor-singlet axial vector, pseudoscalar meson, and pseudoscalar glueball (topological charge) correlator. We find that even a very simple holographic model defined on a slice of five-dimensional anti-de Sitter space provides a qualitatively correct description of QCD correlation functions. We study the role of anomaly terms, and show that both Euclidean positivity and low energy theorems based on the axial anomaly relation are correctly implemented. We compare the results with expectations from an instanton model of the QCD vacuum.
Two-wavelength volume holographic recording in thick PQ-doped PMMA photopolymer
NASA Astrophysics Data System (ADS)
Lin, June H.; Hsu, Ken Y.; Lin, Shiuan H.
2013-05-01
We report holographic recording in thick phenanthrenequinone-doped poly(methyl methacrylate) (PQ/PMMA) photopolymer material via the two-wavelength technique. By using gating light at 325 nm and writing light at 647 nm two-wavelength holographic recording is achieved. Non-volatile readout of a holographic image under 24 hours continuous reconstruction is demonstrated. A four-level modeling for the photochemical procedures of the two-wavelength holographic recording is proposed, and dynamic behaviors of the holograms are illustrated. A planar integrated optical correlator system is constructed by selective writing of holographic optical elements via two-wavelength holographic recording on a photopolymer disk.
Volume Holographic Imaging in Transmission Geometry
Arnab Sinha; Wenyang Sun; Tina Shih; George Barbastathis
2004-01-01
We address the performance of transmission geometry volume holograms as depth-selective imaging elements. We consider two simple implementations using holograms recorded with spherical and plane beams. We derive the point-spread function (PSF) of these systems using volume diffraction theory and use the PSF to estimate depth resolution. Furthermore, we show that appropriately designed objective optics can significantly improve the depth
Holographic volume gratings in a glass-like polymer material
NASA Astrophysics Data System (ADS)
Mahilny, U. V.; Marmysh, D. N.; Stankevich, A. I.; Tolstik, A. L.; Matusevich, V.; Kowarschik, R.
2006-02-01
We demonstrate a possibility to write efficient and thermally stable volume holographic gratings in a glassy polymer material based on PMMA and phenanthrenequinone with layers prepared, by casting the liquid solution of ingredients on a substrate and drying to a solid state. A high concentration of phenanthrenequinone (up to 4 mol. %) makes it possible to use photosensitive layers of lower thicknesses (50 180 ?m) for the recording of efficient holographic gratings. The exposing is followed by a thermal amplification of the grating due to diffusion of residual phenanthrenequinone molecules and fixation by an incoherent optical illumination. We present experimental temporal curves of the refractive index modulation and diffraction efficiency both under the exposure and the heating process. The behavior of the gratings under temperatures up to 140 °C has been studied.
Multiplexing volume holographic gratings for a spectral-spatial imaging system
NASA Astrophysics Data System (ADS)
Luo, Yuan; Gelsinger, Paul J.; Barton, Jennifer K.; Barbastathis, George; Kostuk, Raymond K.
2008-02-01
Multiplexed gratings can be used in an imaging system to project depth sections of a tested object onto different surface locations of a camera. This technique is based on volume holographic Bragg filters used in conjunction with conventional optical imaging components to form a volume holographic imaging system (VHIS). Due to the high angular selectivity and high wavelength selectivity of the system, the VHIS can be used to provide spectral-spatial information of the object that is being observed, and eliminate the need for mechanical scanning. Multiple sections of the object can be viewed by using angle multiplexed holographic elements formed in a volume holographic material. To achieve the highly selective characteristic of a holographic filter, 2mm thick samples of phenanthrenequinone-doped methyl methacrylate (PQ-PMMA) is used as the holographic recording materials. Rigorous coupled wave models are used to theoretically predict the performance of the gratings. Results from both modeling and experiments are presented.
Photochromic polymers for making volume phase holographic gratings: between theory and practice
Andrea Bianco; Giorgio Pariani; Chiara Bertarelli; Filippo M. Zerbi
2010-01-01
Volume Phase Holographic Gratings (VPHGs) are dispersing elements which are finding wide spread in modern optical instrumentations, also in the astronomical field. Since photochromic materials show a change in the refractive index (Deltan) upon photoirradiation, in principle they can be conveniently applied to produce rewritable holographic devices for the near-IR region. Diarylethene-based photochromic films with Deltan large enough to meet
ATLAS: a Cassegrain spectrograph based on volume phase holographic gratings
J. G. Robertson; K. Taylor; I. K. Baldry; P. R. Gillingham; S. C. Barden
2000-06-27
We are proposing a new spectrograph (ATLAS) which would revolutionise intermediate-dispersion observations at the AAT. Based on the new technology of Volume Phase Holographic gratings, and using transmission optics, ATLAS offers high throughput and a wide field (24'). It will be ideally suited to extensive surveys of faint objects. It has been designed with a collimated beam diameter of 150 mm, giving resolution lambda/delta lambda up to nearly 10,000 with a 1.5 arcsecond slit and good efficiency. It will be a dual-beam instrument, to maximise observing speed and allow optimised optical coatings to be used. The project is working towards its Concept Design Review which will occur during 2000.
Development of thick volume holographic gratings for narrowband spectral filter applications
R. I. Billmers; E. J. Billmers; M. E. Ludwig; R. Burzynski; J. F. Weibel; M. K. Casstevens
2004-01-01
We have written volume holographic gratings in MEMPLEX photopolymer substrate of thickness >5 mm. Spectral acceptance of <1 \\/spl Aring\\/ coupled with high diffraction efficiencies around 500 nm demonstrate these holograms to be ideal for narrowband spectral filtering applications.
Phase aberration correction by correlation in digital holographic adaptive optics
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
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
Cross-talk noise in volume holographic memory with spherical reference beams
NASA Astrophysics Data System (ADS)
Yi, Xianmin; Yeh, Pochi; Gu, Claire
1995-09-01
We investigate angle-multiplexed volume holographic memory with spherical reference beams, for which the spherical approximation is made to model the wave-front distortion in general. We find that the angular selectivity and the cross-talk noise with spherical reference beams are close to those with planar reference beams. The results indicate that angle-multiplexed volume holographic memory can be realized in compact systems for which large wave-front distortion is expected.
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.
A 6-beam combiner using superimposed volume index holographic gratings
Yum, HoNam
2005-11-01
In this thesis, a 6-beam combiner using multiplexed holograms in dye-doped polymer is investigated. It is realized by recording six superimposed holographic gratings, which show uniform diffraction efficiency. The coupled ...
HOE/lensless matched spatial filter wavelength-scaling correlator. [Holographic Optical Element
NASA Technical Reports Server (NTRS)
Shen, M.; Casasent, D.; Luu, T. K.; Feng, B.
1980-01-01
A scaling correlator optical pattern recognition system is described in which a lensless matched spatial filter (with the second Fourier transform lens and the matched spatial filter recorded on the same plate) is used with a first Fourier transform lens that is also an holographic optical element. The matched spatial filter is recorded at one wavelength and correlation is obtained at a second wavelength. Experimental demonstration and output correlation SNR data are reported, together with a comparison of the system's noise level using conventional optics and holographic elements.
Development of narrow-linewidth diode lasers by use of volume holographic transmission gratings
G. Ewald; K.-M. Knaak; S. Götte; K. D. A. Wendt; H.-J. Kluge
2005-01-01
We present two diode laser setups that employ volume holographic transmission gratings to provide optical feedback. The advantage of this kind of grating is high diffraction efficiency and the possibility to place optical elements on both sides of the grating. This allows for advanced external cavities and adjustable feedback efficiency. The first setup is a diode laser in the Littman
Broadband behavior of transmission volume holographic optical elements for solar concentration.
Bañares-Palacios, Paula; Álvarez-Álvarez, Samuel; Marín-Sáez, Julia; Collados, María-Victoria; Chemisana, Daniel; Atencia, Jesús
2015-06-01
A ray tracing algorithm is developed to analyze the energy performance of transmission and phase volume holographic lenses that operate with broadband illumination. The agreement between the experimental data and the theoretical treatment has been tested. The model has been applied to analyze the optimum recording geometry for solar concentration applications. PMID:26072891
Duc Dung Do; Tien Viet Vu; Nam Kim; Jun Won An; Kwon Yeon Lee
2006-01-01
The number of channels of an optical communication system is increasing rapidly. In this paper, the demonstration of a 130-channel demultiplexer based on the cascaded volume holographic gratings is presented. Those gratings are recorded separately in 100-mum thickness photopolymer films, which attached on both sides of a glass substrate. They have different grating periods, slant angles, and center wavelengths. By
Holographic CFTs on maximally symmetric spaces: correlators, integral transforms and applications
Hinterbichler, Kurt; Trodden, Mark
2015-01-01
We study one and two point functions of conformal field theories on spaces of maximal symmetry with and without boundaries and investigate their spectral representations. Integral transforms are found, relating the spectral decomposition to renormalized position space correlators. Several applications are presented, including the holographic boundary CFTs as well as spacelike boundary CFTs, which provide realizations of the pseudo-conformal universe.
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.
Loicq, Jérôme; Venancio, Luis Miguel; Stockman, Yvan; Georges, Marc P
2013-12-01
The special properties of volume phase holographic gratings make them promising candidates for spectrometry applications where high spectral resolution, low levels of straylight, and low polarization sensitivity are required. Therefore it is of interest to assess the maturity and suitability of volume phase holographic gratings as enabling technologies for future space missions, with demanding requirements for spectrometry. One of the main areas of research is related to grating ageing under space radiation. In the present paper, two volume grating technologies are analyzed and compared under gamma irradiation. The performances of both technologies, the photo-thermo-refractive glass and the Dichromated Gelatin, are tested on samples and assessed in the H? and near-infrared bands. The diffraction efficiency degradation under gamma irradiation is assessed. PMID:24513836
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.
NASA Astrophysics Data System (ADS)
Guo, Jinxin; Fujii, Ryuta; Tomita, Yasuo
2015-05-01
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.
Coupling holographic volume gratings in glassy polymeric material for planar lightguides
NASA Astrophysics Data System (ADS)
Mahilny, U. V.; Marmysh, D. N.; Tolstik, A. L.; Matusevich, V.; Kowarschik, R.
2005-09-01
Efficient and thermally stable volume holographic gratings in glassy polymeric material based on PMMA and phenanthrenequinone have been recorded. Photosensitive layers were prepared by casting the liquid solution of ingredients on a substrate and drying to a solid state followed by a separation of the polymeric film. This technique was applied to create a possibility to write highly slanted gratings between prisms and to stick them to lightguides with glue. High diffractive efficiencies and moderate angle selectivity of the gratings were reached due to a high concentration of phenanthrenequinone (up to 4 mol.%) making it possible to use the photosensitive layers of lower thicknesses (60 - 150 ?m) for the recording of the efficient holographic gratings. The exposing is followed by thermal amplification of the grating due to diffusion of unreacted phenanthrenequinone molecules and fixation by an incoherent optical illumination. The processes of generation, amplification and fixation are discussed for holographic gratings. The holographic gratings were written with an Ar-laser (wavelength 514,5 nm). The grating amplification was realized by heating up of the sample to 50-85°C.
NASA Astrophysics Data System (ADS)
Lin, Shiuan Huei; Chen, Po-Lin; Chuang, Chun-I.; Chao, Yu-Faye; Hsu, Ken Y.
2011-08-01
Volume polarization holographic recording in phenanthrenequinone-doped poly (methyl methacrylate) photopolymer is obtained. Photoinduced birefringence in a 2mm thick sample is measured by a phase-modulated ellipsometry. The birefringence induced in this material by linearly polarized beam at 514nm 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.
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
NASA Astrophysics Data System (ADS)
Yi, Xianmin; Campbell, Scott; Yeh, Pochi; Gu, Claire
1995-04-01
We investigate the cross-talk noise in optical storage based on angle-multiplexed image plane volume holograms. Simple expressions for the signal-to-noise ratio and the storage density are obtained. The cross-talk noise is found to limit the size of the pixels and the number of recorded holograms. The cross-talk-limited storage density of image plane holographic storage is found to be close to that of Fourier plane holographic storage.
Schönemann, P H
1987-01-01
Convolutions and correlations # in spaces H of doubly infinite sequences are related by a # b = S(a Sb), where S is an involution which reflects the order in the integral domain Z on which the sequences are defined. This relation can be used to represent a non-associative correlation algebra (H, #) by an associative convolution algebra equipped with the involution S which, as is shown, greatly simplifies derivations. Related matrix representations of #, S are given for sequences with finite support in Ren. Some implications for holographic memory models are discussed. PMID:3620535
Accurate diffraction efficiency control for multiplexed volume holographic gratings
Chen, Ray
.1117/1.1512661] Subject terms: diffraction; gratings; holograms. Paper 020007 received Jan. 9, 2002; revised manuscript interconnect systems. The photopolymer-based volume hologram is an attractive option for making high-efficiency gratings. The advantage of photopolymers over other types of emulsion, such as dichromated gelatin
Volume holographic spectral-spatial imaging of biological tissue
NASA Astrophysics Data System (ADS)
Kostuk, Raymond K.; Barton, Jennifer K.; Luo, Yuan; Castro, Jose M.; Barbastathis, George
2011-10-01
In this presentation we discuss a new type of optical microscope that is capable of obtaining spectral and spatial information from biological tissue samples. The current system uses multiplexed volume holograms to probe multiple depths of a tissue sample without the need for scanning. This greatly simplifies the instrument and should allow it to be adapted for laproscopic applications. The technique can be combined with fluorescent dye markers to identify cancerous tissue.
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.
Cryogenic tests of volume-phase holographic gratings: results at 100 K
Naoyuki Tamura; Graham J. Murray; Peter Luke; Colin Blackburn; David J. Robertson; Nigel A. Dipper; Ray M. Sharples; Jeremy R. Allington-Smith
2006-09-04
We present results from cryogenic tests of Volume-Phase Holographic(VPH) gratings at 100 K. The aims of these tests are to see whether the diffraction efficiency as a function of wavelength is significantly different at a low temperature from that at room temperature and to see how the performance of a VPH grating is affected by a number of thermal cycles. We have completed 10 cycles between room temperature and 100 $K$, and find no clear evidence that the diffraction efficiency changes with temperature or with successive thermal cycle.
Optimal resolution in Fresnel incoherent correlation holographic fluorescence microscopy.
Brooker, Gary; Siegel, Nisan; Wang, Victor; Rosen, Joseph
2011-03-14
Fresnel Incoherent Correlation Holography (FINCH) enables holograms and 3D images to be created from incoherent light with just a camera and spatial light modulator (SLM). We previously described its application to microscopic incoherent fluorescence wherein one complex hologram contains all the 3D information in the microscope field, obviating the need for scanning or serial sectioning. We now report experiments which have led to the optimal optical, electro-optic, and computational conditions necessary to produce holograms which yield high quality 3D images from fluorescent microscopic specimens. An important improvement from our previous FINCH configurations capitalizes on the polarization sensitivity of the SLM so that the same SLM pixels which create the spherical wave simulating the microscope tube lens, also pass the plane waves from the infinity corrected microscope objective, so that interference between the two wave types at the camera creates a hologram. This advance dramatically improves the resolution of the FINCH system. Results from imaging a fluorescent USAF pattern and a pollen grain slide reveal resolution which approaches the Rayleigh limit by this simple method for 3D fluorescent microscopic imaging. PMID:21445140
Dual-wavelength microarray fluorescence detection system using volume holographic filter.
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
Shi, Xiaoyan; Zhao, Daomu
2011-02-10
Based on joint transform correlator (JTC) architecture and holographic techniques, a new method for image hiding is presented. A hidden image encrypted by JTC architecture is embedded in the Fourier hologram of the host image. Inverse Fourier transform can be used to obtain the watermarked image, and JTC architecture is used to decode the hidden image from the watermarked hologram. Unlike other watermarking techniques, by prechoosing information, the noise added to the recovered hidden image by the host can be reduced. Unlike other watermarking systems based on double random-phase encoding, no conjugate key is used to recover the hidden image. Theoretical analyses have shown the system's feasibility. Computer simulations are presented to verify the system's validity and efficiency. Numerical simulations also show that the proposed system is robust enough to resist attacks, such as occlusion, noise, and filtering. PMID:21343999
Volume holographic storage using phenanthrenequinone-doped poly (methyl methacrylate) photopolymer
NASA Astrophysics Data System (ADS)
Wang, Jian; Sun, Xiudong
2008-12-01
The PMMA material doped with high content of PQ is fabricated in our Lab. Dynamic range is studied to be 2.5mm-1 by peristrophic multiplexing. In Angular multiplexing based on rotating material, 100 frames of gray image are recorded in a 1mm thick sample and the reproduced images have a good quality. The storage capacity is calculated to be 3.1× 109 bits/cm3, which implies that our PQ/PMMA material is suitable for volume holographic storage. The intensity of grating increases with time and the shift of sensitivity angle, which is about 0.1375 deg for each multiplexing image in reproduced process, are also found. We give a qualitative analysis from the aspect of dark reaction of sample.
NASA Astrophysics Data System (ADS)
Watanabe, Eriko; Ikeda, Kanami; Kodate, Kashiko
2012-10-01
Using a holographic disc memory on which a huge amount of data can be stored, we constructed an ultra-high-speed, all-optical correlation system. In this method, multiplex recording is, however, restricted to "one page" on "one spot." In addition, signal information must be normalized as data of the same size, even if the object data size is smaller. Therefore, this system is difficult to apply to part of the object data scene (i.e., partial scene searching and template matching), while maintaining high accessibility and programmability. In this paper, we develop a holographic correlation system by a time division recording method that increases the number of multiplex recordings on the same spot. Assuming that a four-channel detector is utilized, 15 parallel correlations are achieved by a time-division recording method. Preliminary correlation experiments with the holographic optical disc setup are carried out by high correlation peaks at a rotational speed of 300 rpm. We also describe the combination of an optical correlation system for copyright content management that searches the Internet and detects illegal contents on video sharing websites.
Allan Adams; Lincoln D. Carr; Thomas Schaefer; Peter Steinberg; John E. Thomas
2012-05-23
Strongly correlated quantum fluids are phases of matter that are intrinsically quantum mechanical, and that do not have a simple description in terms of weakly interacting quasi-particles. Two systems that have recently attracted a great deal of interest are the quark-gluon plasma, a plasma of strongly interacting quarks and gluons produced in relativistic heavy ion collisions, and ultracold atomic Fermi gases, very dilute clouds of atomic gases confined in optical or magnetic traps. These systems differ by more than 20 orders of magnitude in temperature, but they were shown to exhibit very similar hydrodynamic flow. In particular, both fluids exhibit a robustly low shear viscosity to entropy density ratio which is characteristic of quantum fluids described by holographic duality, a mapping from strongly correlated quantum field theories to weakly curved higher dimensional classical gravity. This review explores the connection between these fields, and it also serves as an introduction to the Focus Issue of New Journal of Physics on Strongly Correlated Quantum Fluids: from Ultracold Quantum Gases to QCD Plasmas. The presentation is made accessible to the general physics reader and includes discussions of the latest research developments in all three areas.
NASA Astrophysics Data System (ADS)
Lin, Shiuan-Huei; Chen, Po-Lin; Hsiao, Yi-Nan; Whang, Wha-Tzong
2008-02-01
We present our studies on the photopolymer of poly(methyl methacrylate) (PMMA) doped with 9,10-phenanthrenequinone based derivatives for volume holographic storage. By introducing different functional groups on the side-chain of 9,10-phenanthrenequinone molecule, the holographic characteristics of the material can be modified. The photoreaction involved with the holographic recording in the samples was investigated by measuring UV-Vis absorption spectrum and mass spectrum. The experimental results show that the similar behaviors were exhibited in these photopolymers. It is found that phase hologram recording in our PQ derivatives doped PMMA photopolymer involves a structure change of the quinone based molecule, which induces a strong change of the refractive index. Experimental characterizations on holographic data storage, including material sensitivity, dynamic range ( M#) and bit-error-rate have been performed. We found that, by selecting appropriate functional groups, an improvement in sensitivity and M# for holographic data storage can be achieved.
Silicon oxide nano-particles doped PQ-PMMA for volume holographic imaging filters
Luo, Yuan; Russo, Juan M.; Kostuk, Raymond K.; Barbastathis, George
2011-01-01
Holographic imaging filters are required to have high Bragg selectivity to obtain spatial-spectral information within a three-dimensional object. In this Letter, we present the design of holographic imaging filters formed using silicon oxide nano-particles (nano-SiO2) in PQ-PMMA polymer recording material. This combination offers greater angular and spectral selectivity and increases the diffraction efficiency of holographic filters. The holographic filters with optimized ratio of nano-SiO2 in PQ-PMMA can significantly improve the performance of Bragg selectivity and diffraction efficiency by 53% and 16%, respectively. We present experimental results and data analysis demonstrating this technique in use for holographic spatial-spectral imaging filters. PMID:20410989
Periodical energy oscillation and pulse splitting in sinusoidal volume holographic grating.
Yan, Xiaona; Gao, Lirun; Dai, Ye; Yang, Xihua; Chen, Yuanyuan; Ma, Guohong
2014-07-28
This paper presents dynamical diffraction properties of a femtosecond pulse in a sinusoidal volume holographic grating (VHG). By the modified coupled-wave equations of Kogelnik, we show that the diffraction of a femtosecond pulse on the VHG gives rise to periodical energy oscillation and pulse splitting. In the initial stage of diffraction, one diffracted pulse and one transmitted pulse emerge, and energy of the transmitted pulse periodically transfers to the diffracted pulse and vice versa. In the latter stage, both the diffracted and transmitted pulses split into two spatially separated pulses. One pair of transmitted and diffracted pulses propagates in the same direction and forms the output diffracted dual pulses of the VHG, and the other pair of pulses forms the output transmitted dual pulses. The pulse interval between each pair of dual pulses is in linearly proportional to the refractive index modulation and grating thickness. By the interference effect and group velocity difference we give explanations on the periodical energy oscillation and pulse splitting respectively. PMID:25089472
Multidimensional spatial-spectral holographic interpretation of NMR photography
NASA Astrophysics Data System (ADS)
Kiruluta, Andrew J. M.
2006-05-01
A spectral holographic interpretation arises naturally in nuclear magnetic resonance (NMR) photography from either the intrinsic chemical shift anisotropy of the spin system or the field inhomogeneity due to the applied spatial encoding gradients. We can thus think of NMR photography as arising from a "diffraction" off a spatial-spectral holographic grating. The spatial holographic component arises from a high dielectric constant (>50) of the NMR medium at high field strength (>4T) when the excitation wavelength is commensurate with the size of the NMR sample; otherwise, it is a volume spectral holographic grating. In this paper, the NMR localized spectroscopy (imaging) equation is derived from the principles of spatial-spectral holography. Holographic properties of storage and programmable time delay and time reversal are shown to follow naturally from this viewpoint and are experimentally demonstrated in an inhomogeneously broadened NMR sample. These ideas are shown to be extendable to complex signal processing functions such as recognition, correlations, and triple products.
NASA Astrophysics Data System (ADS)
Argurio, Riccardo; Bertolini, Matteo; Musso, Daniele; Porri, Flavio; Redigolo, Diego
2015-06-01
We find the fingerprints of the Goldstino associated to spontaneous supersymmetry breaking in a prototype holographic model for a strongly coupled field theory. The Goldstino massless pole arises in two-point correlators of the supercurrent, due to contact terms in supersymmetry Ward identities. We show how these contact terms are obtained from the holographic renormalization of the gravitino sector, independently of the details of the bulk background solution. For completeness, we prove the existence of a family of such solutions in a simple supergravity model.
A simple method for Bragg diffraction in volume holographic gratings Alexander Heifetz,a
Shahriar, Selim
for optical communications,1113 and intracav- ity Bragg gratings for various types of lasers.1416 A rigorous. The hologram or holographic grating is defined to be the spatial modulation of the refrac- tive index
Holographic volume gratings in glassy polymeric material as coupling elements of planar lightguides
NASA Astrophysics Data System (ADS)
Mahilny, U. V.; Marmysh, D. N.; Tolstik, A. L.; Matusevich, V.; Kowarschik, R.
2007-06-01
The formation conditions for holographic gratings in photopolymeric material based on PMMA and phenanthrenequinone featuring high diffraction efficiency and thermal stability are established. The possibilities for their use in radiation coupling systems for planar lightguides are demonstrated.
Cross-correlations in volume space: Differences between buy and sell volumes
NASA Astrophysics Data System (ADS)
Lee, Sun Young; Hwang, Dong Il; Kim, Min Jae; Koh, In Gyu; Kim, Soo Yong
2011-03-01
We study the cross-correlations of buy and sell volumes on the Korean stock market in high frequency. We observe that the pulling effects of volumes are as small as that of returns. The properties of the correlations of buy and sell volumes differ. They are explained by the degree of synchronization of stock volumes. Further, the pulling effects on the minimal spanning tree are studied. In minimal spanning trees with directed links, the large pulling effects are clustered at the center, not uniformly distributed. The Epps effect of buy and sell volumes are observed. The reversal of the cross-correlations of buy and sell volumes is also detected.
Pannopnut, Papinwit; Kitporntheranunt, Maethaphan; Paritakul, Panwara; Kongsomboon, Kittipong
2015-01-01
Objective To investigate the correlation between ultrasound measured placental volume and collected umbilical cord blood (UCB) volume in term pregnancy. Material and Methods An observational cross-sectional study of term singleton pregnant women in the labor ward at Maha Chakri Sirindhorn Medical Center was conducted. Placental thickness, height, and width were measured using two-dimensional (2D) ultrasound and calculated for placental volume using the volumetric mathematic model. After the delivery of the baby, UCB was collected and measured for its volume immediately. Then, birth weight, placental weight, and the actual placental volume were analyzed. The Pearson’s correlation was used to determine the correlation between each two variables. Results A total of 35 pregnant women were eligible for the study. The mean and standard deviation of estimated placental volume and actual placental volume were 534±180 mL and 575±118 mL, respectively. The median UCB volume was 140 mL (range 98–220 mL). The UCB volume did not have a statistically significant correlation with the estimated placental volume (correlation coefficient 0.15; p=0.37). However, the UCB volume was significantly correlated with the actual placental volume (correlation coefficient 0.62; p<0.001) and birth weight (correlation coefficient 0.38; p=0.02). Conclusion The estimated placental volume by 2D ultrasound was not significantly correlated with the UCB volume. Further studies to establish the correlation between the UCB volume and the estimated placental volume using other types of placental imaging may be needed.
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.
Zhuo-Yi Huang; Bin Wang; Elcio Abdalla; Ru-Keng Su
2006-04-21
We investigate the question of the suppression of the CMB power spectrum for the lowest multipoles in closed Universes. The intrinsic reason for a lowest cutoff in closed Universes, connected with the discrete spectrum of the wavelength, is shown not to be enough to explain observations. We thus extend the holographic cosmic duality to closed universes by relating the dark energy equation of state and the power spectrum, showing a suppression behavior which describes the low l features extremely well. We also explore the possibility to disclose the nature of the dark energy from the observed small l CMB spectrum by employing the holographic idea.
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.
Holographic recording in polymeric materials with applications
NASA Astrophysics Data System (ADS)
Steckman, Gregory J.
2001-12-01
This thesis presents the results of research in volume holographic recording in several polymeric recording materials and their use in selected applications. The first chapter discusses the key properties of holographic recording materials. The second chapter develops a technique for calculating exposure schedules for photorefractive polymers which do not exhibit mono- exponential recording dynamics. It is determined that these materials require performance improvements before they can be successfully applied to many interesting applications of volume holography, such as holographic data storage and optical correlators which are described in later chapters. The third chapter investigates recording in diffusion amplification based polymer materials. This class of materials overcomes many limitations of other polymer types, such as limited thicknesses and volume shrinkage. A new material based on the diffusion amplification principle is developed with the goal of increasing dynamic range. The new material, a naphtoquinone and PMMA based co-polymer, is demonstrated in holographic recording experiments. In the fourth chapter, holographic data storage experiments are performed and a storage density of 7 bits/?m2 is achieved. A holographic data storage system which utilizes shift multiplexing is modeled and simulated to determine optimal system parameters and material characteristics. It is discovered that the dynamic range of the material used, phenanthrenequinone doped poly(methyl methacrylate), is insufficient to provide very high data storage densities. In the fifth chapter attention is focused on the development and characterization of an optical holographic correlator system using the DuPont BRF-150 photopolymer. The system is used for image recognition and tracking. The performance of the system is characterized with multiple 2-d and 3-d objects with respect to camera resolution, magnification, rotation, and other transformations. The system is demonstrated to be capable of simultaneously recognizing and tracking multiple targets, even in the presence of extraneous objects and partial obscuring of the targets. The final chapter describes the development of a high- speed holographic movie camera. Utilizing a Q-switched Nd:YAG pulse laser and Aprilis ULSH500-7A recording material, multi-frame holographic exposures with a 80 MHz frame rate are recorded.
McFadden, Paul; Skenderis, Kostas, E-mail: P.L.McFadden@uva.nl, E-mail: K.Skenderis@uva.nl [Institute for Theoretical Physics, Science Park 904, 1090 GL Amsterdam (Netherlands)
2011-05-01
We investigate the non-Gaussianity of primordial cosmological perturbations within our recently proposed holographic description of inflationary universes. We derive a holographic formula that determines the bispectrum of cosmological curvature perturbations in terms of correlation functions of a holographically dual three-dimensional non-gravitational quantum field theory (QFT). This allows us to compute the primordial bispectrum for a universe which started in a non-geometric holographic phase, using perturbative QFT calculations. Strikingly, for a class of models specified by a three-dimensional super-renormalisable QFT, the primordial bispectrum is of exactly the factorisable equilateral form with f{sub NL}{sup equil.} = 5/36, irrespective of the details of the dual QFT. A by-product of this investigation is a holographic formula for the three-point function of the trace of the stress-energy tensor along general holographic RG flows, which should have applications outside the remit of this work.
Correlations between Areas, Volumes or Body Fat and Anthropometric Variables
ALBULESCU, DANA; ILIESCU, ADRIANA
2014-01-01
Body fat is an important determinant of nutritional status and health. This paper aims to demonstrate the existence of significant correlations between areas, or volumes of fat and anthropometric variables. PMID:25729592
Correlations between Areas, Volumes or Body Fat and Anthropometric Variables.
Albulescu, Dana; Iliescu, Adriana
2014-01-01
Body fat is an important determinant of nutritional status and health. This paper aims to demonstrate the existence of significant correlations between areas, or volumes of fat and anthropometric variables. PMID:25729592
Nikolaou, Panayiotis; Whiting, Nicholas; Eschmann, Neil A; Chaffee, Kathleen E; Goodson, Boyd M; Barlow, Michael J
2009-04-01
Volume holographic gratings (VHGs) can be exploited to narrow the spectral output of high-power laser-diode arrays (LDAs) by nearly an order of magnitude, permitting more efficient generation of laser-polarized noble gases for various applications. A approximately 3-fold improvement in (129)Xe nuclear spin polarization, P(Xe), (compared to a conventional LDA) was achieved with the VHG-LDA's center wavelength tuned to a wing of the Rb D(1) line. Additionally, an anomalous dependence of P(Xe) on the xenon density within the OP cell is reported-including high P(Xe) values (>10%) at high xenon partial pressures (approximately 1000 torr). PMID:19162517
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 (>10^{7} cells/ml) with submicron resolutions (<0.5 µm) over substantial depth and to obtain thousands of 3D cell trajectories. PMID:25607177
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.
Correlation between olfactory bulb volume and olfactory function.
Buschhüter, D; Smitka, M; Puschmann, S; Gerber, J C; Witt, M; Abolmaali, N D; Hummel, T
2008-08-15
The olfactory bulb (OB) is considered to be the most important relay station in odor processing. Involving 125 randomly selected subjects (58 men, 67 women; age range: 19 to 79 years), the present study aimed to investigate a possible correlation between OB volume and specific olfactory functions including odor threshold, odor discrimination, and odor identification. The history of all participants was taken in great detail to exclude possible causes of smell dysfunction. All participants received an otolaryngological investigation including a volumetric scan of the brain (MRI), lateralized olfactory tests and a screen for cognitive impairment. Volumetric measurements of the right and left OB were performed by manual segmentation of the coronal slices through the OB. Significant correlations between OB volumes in relation to olfactory function were observed, independent of the subjects' age. Additionally, OB volumes decreased with age. In agreement with previous research the present study confirmed the correlation between OB volume and specific olfactory functions. Furthermore, the correlation between OB volume and olfactory function was not mediated by the subjects' age. In conclusion, the present data obtained from a relatively large group of subjects forms the basis for age-related normative values of OB volumes. PMID:18555701
NASA Astrophysics Data System (ADS)
Hsiao, Yi-Nan; Whang, Wha-Tzong; Lin, Shiuan Huei; Hsu, Ken Y.
2006-11-01
We fabricate and characterize a novel holographic recording photopolymer named ZnMA/PQ co-doped PMMA, a poly(methyl methacrylate) (PMMA) doped with two materials: zinc methacrylate (ZnMA) and 9,10-phenanthrenequinone (PQ) molecules. A technique for fabricating thick samples of 2 mm thick is described. The optical and holographic characteristics of the samples are experimentally investigated. The results show that by adding ZnMA, the material M/# and sensitivity for holographic recording have been improved.
Correlation between olfactory bulb volume and olfactory function
D. Buschhüter; M. Smitka; S. Puschmann; J. C. Gerber; M. Witt; N. D. Abolmaali; T. Hummel
2008-01-01
The olfactory bulb (OB) is considered to be the most important relay station in odor processing. Involving 125 randomly selected subjects (58 men, 67 women; age range: 19 to 79 years), the present study aimed to investigate a possible correlation between OB volume and specific olfactory functions including odor threshold, odor discrimination, and odor identification. The history of all participants was
Organic Materials for Holographic Applications
Alan Gengsheng Chen
1993-01-01
Volume holography plays an important role in modern optical technology. This research explores organic materials for holographic applications in optical systems. A novel medium composed of azo dye molecules (methyl red sodium salt) and liquid crystals (PCB) was developed for holographic applications. A conformation change of azo dye molecules in cis-trans isomerization reorients liquid crystal molecules. Reversible polarization holograms are
Cross-correlations between volume change and price change.
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
Cross-correlations between volume change and price change
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 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 ?? of the probability density function P(|R?|) ? |R?|?1??? 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 ??, we calculate the time intervals ?q between events where R? > q. We demonstrate that ??q, the average of ?q, obeys ??q ? q??. We find ?? ? 3. Furthermore, by aggregating all ?q values of 28 global financial indices, we also observe an approximate inverse cubic law. PMID:20018772
Barkhouser, Robert; Gunn, James E
2014-01-01
The Prime Focus Spectrograph (PFS) is a major instrument under development for the 8.2 m Subaru telescope. Four identical spectrograph modules are located in a room above one Nasmyth focus. A 55~m fiber optic cable feeds light to the spectrographs from a robotic positioner at the 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. The spectrograph optical design consists of a Schmidt collimator, two dichroic beamsplitters to split 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~\\textmu m, and good imaging performance at the fast f/1.05 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 co...
Adams, Allan
Strongly correlated quantum fluids are phases of matter that are intrinsically quantum mechanical and that do not have a simple description in terms of weakly interacting quasiparticles. Two systems that have recently ...
Holographic calculations of Euclidean Wilson loop correlator in Euclidean anti-de Sitter space
NASA Astrophysics Data System (ADS)
Ziama, Sannah
2015-04-01
The correlation functions of two or more Euclidean Wilson loops of various shapes in Euclidean anti-de Sitter space are computed by considering the minimal area surfaces connecting the loops. The surfaces are parametrized by Riemann theta functions associated with genus three hyperelliptic Riemann surfaces. In the case of two loops, the distance L by which they are separated can be adjusted by continuously varying a specific branch point of the auxiliary Riemann surface. When L is much larger than the characteristic size of the loops, then the loops are approximately regarded as local operators and their correlator as the correlator of two local operators. Similarly, when a loop is very small compared to the size of another loop, the small loop is considered as a local operator corresponding to a light supergravity mode.
Holographic baryons and instanton crystals
NASA Astrophysics Data System (ADS)
2015-06-01
In a wide class of holographic models, like the one proposed by Sakai and Sugimoto, baryons can be approximated by instantons of non-Abelian gauge fields that live on the world-volume of flavor D-branes. In the leading order, those are just the Yang-Mills instantons, whose solutions can be constructed from the celebrated Atiyah-Drinfeld-Hitchin-Manin (ADHM) construction. This fact can be used to study various properties of baryons in the holographic limit. In particular, one can attempt to construct a holographic description of the cold dense nuclear matter phase of baryons. It can be argued that holographic baryons in such a regime are necessarily in a solid crystalline phase. In this review, we summarize the known results on the construction and phases of crystals of the holographic baryons.
Multidimensional spatial-spectral holographic interpretation of NMR photography.
Kiruluta, Andrew J M
2006-05-21
A spectral holographic interpretation arises naturally in nuclear magnetic resonance (NMR) photography from either the intrinsic chemical shift anisotropy of the spin system or the field inhomogeneity due to the applied spatial encoding gradients. We can thus think of NMR photography as arising from a "diffraction" off a spatial-spectral holographic grating. The spatial holographic component arises from a high dielectric constant (>50) of the NMR medium at high field strength (>4 T) when the excitation wavelength is commensurate with the size of the NMR sample; otherwise, it is a volume spectral holographic grating. In this paper, the NMR localized spectroscopy (imaging) equation is derived from the principles of spatial-spectral holography. Holographic properties of storage and programmable time delay and time reversal are shown to follow naturally from this viewpoint and are experimentally demonstrated in an inhomogeneously broadened NMR sample. These ideas are shown to be extendable to complex signal processing functions such as recognition, correlations, and triple products. PMID:16729804
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 potential of this technology, a set of three prototype VPH gratings (one each of the blue, red, and NIR designs) was ordered and has been recently delivered. The goal for these prototype units, but not a requirement, was to meet the specifications for the final gratings in order to serve as spares and also as early demonstration and integration articles. In this paper we present the design and specifications for the PFS gratings, the plan and setups used for testing both the prototype and final gratings, and results from recent optical testing of the prototype grating set.
Correlation among body height, intelligence, and brain gray matter volume in healthy children
Yasuyuki Taki; Hiroshi Hashizume; Yuko Sassa; Hikaru Takeuchi; Michiko Asano; Kohei Asano; Yuka Kotozaki; Rui Nouchi; Kai Wu; Hiroshi Fukuda; Ryuta Kawashima
A significant positive correlation between height and intelligence has been demonstrated in children. Additionally, intelligence has been associated with the volume of gray matter in the brains of children. Based on these correlations, we analyzed the correlation among height, full-scale intelligence quotient (IQ) and gray matter volume applying voxel-based morphometry using data from the brain magnetic resonance images of 160
Riccardo Argurio; Matteo Bertolini; Daniele Musso; Flavio Porri; Diego Redigolo
2015-06-12
We find the fingerprints of the Goldstino associated to spontaneous supersymmetry breaking in a prototype holographic model for a strongly coupled field theory. The Goldstino massless pole arises in two-point correlators of the supercurrent, due to contact terms in supersymmetry Ward identities. We show how these contact terms are obtained from the holographic renormalization of the gravitino sector, independently of the details of the bulk background solution. For completeness, we provide an example of a family of such solutions in a simple supergravity model.
NASA Technical Reports Server (NTRS)
Wuerker, R. F.
1972-01-01
Review of the techniques and applications of holographic interferometry. The recording of a 'reflected-light' hologram with a gas laser is described in order to illustrate the unique optical properties of a hologram. Special types of interferometric measurement, such as stored-beam holographic interferometry and double-exposure holographic interferometry, are then discussed. Applications of gas-laser holographic interferometry to the detection of internal flaws in steel tubing are cited, as well as applications involving the testing of aircraft and automotive tires and aircraft honeycomb composites for bond integrity and the prediction of failure in mechanical components. Finally, applications of the pulsed solid-state ruby laser in holographic interferometry are considered.
Extreme-ultraviolet Bragg holographic structures: theory and experiments
Tomasz Jannson; Gajendra Savant; Liping Wang
1991-01-01
A theoretical analysis of extreme-ultraviolet (XUV) Bragg (volume) holographic diffraction structures with arbitrary periodic spatial-modulation profiles is presented, and two basic approaches for the fabrication of XUV holographic optical elements suggested by the theory are discussed. The theoretical results are compared with preliminary experimental observations from XUV Bragg holographic structures recently fabricated in the laboratory, and fairly good agreement is
Liu, Hongpeng; Yu, Dan; Li, Xuecong; Luo, Suhua; Jiang, Yongyuan; Sun, Xiudong
2010-03-29
The dark enhancements of diffraction efficiency in single and multiple gratings are investigated theoretically and experimentally in phenanthrenequinone doped poly-(methyl methacrylate) materials. It is demonstrated a possibility to improve holographic characteristics of the material via the enhancement. Nearly 17-fold increment of diffraction efficiency is observed after exposure. The dependences of PQ's concentration on the rate and increment of dark enhancement are achieved quantitatively. And the enhancement in multiplexing is presented as a simple and efficient method to improve response of the material and homogeneity of diffraction efficiency. PQ's diffusion and enhancement process of refractive index modulation are simulated by a diffusion model for describing enhancement dynamics qualitatively and quantitatively. This study provides a significant foundation for the application of dark enhancement in holographic storage. PMID:20389668
Polarization-Selective Holographic Optical Element for Dense Magnetooptical Pickup Heads
Viet-Tien Vu; Nam Kim; Jun-Won An; Chang-Won Shin; Kwon-Yeon Lee; Dongwoo Suh; Hojun Rue; Mun-Cheol Paek; Hyeon-Bong Pyo
2004-01-01
A polarization-selective holographic optical element with compact dimensions of 2.4 mm× 1 mm× 1 mm (width × length × thickness) is proposed. The element includes three modules: a holographic polarizing beamsplitter, a holographic input coupler, and a dove-prism coupler so that a simple and dense optical pickup head can be achieved. Polarization properties of holographic volume gratings are briefly discussed.
DIDACTICAL HOLOGRAPHIC EXHIBIT INCLUDING (HOLOGRAPHIC TELEVISION)
de Aguiar, Marcus A. M.
DIDACTICAL HOLOGRAPHIC EXHIBIT INCLUDING HoloTV (HOLOGRAPHIC TELEVISION) José J. Lunazzi , Daniel the beginning. As well as the application of the holographic screens in white light: the television images
Holographic Mutual Information is Monogamous
Patrick Hayden; Matthew Headrick; Alexander Maloney
2011-01-01
We identify a special information-theoretic property of quantum field theories with holographic duals: the mutual informations among arbitrary disjoint spatial regions A,B,C obey the inequality I(A:BC) >= I(A:B)+I(A:C), provided entanglement entropies are given by the Ryu-Takayanagi formula. Inequalities of this type are known as monogamy relations and are characteristic of measures of quantum entanglement. This suggests that correlations in holographic
Sex differences in the correlation of emotional control and amygdala volumes in adolescents
Blanton, Rebecca E.; Chaplin, Tara M.; Sinha, Rajita
2013-01-01
We examined male and female adolescents (8–18 years of age) that were scanned with structural brain MRI and looked for a correlation between volume of the right or the left amygdala and parent-reported ability of emotional control. A sex difference was found in the correlation between emotional control and the corrected volume of the left amygdala (that is the amygdala volume adjusted for total cranial volume). In girls, smaller left amygdala volumes were associated with better emotional control. In boys, larger left amygdala volumes were associated with better emotional control. These findings suggest that healthy girls and boys show a difference in the correlation between parental reports of emotional control and the left amygdala volume. PMID:20729768
NASA Astrophysics Data System (ADS)
Sutcliffe, Paul
2015-06-01
Skyrmions are topological solitons that describe baryons within a nonlinear theory of pions. In holographic QCD, baryons correspond to topological solitons in a bulk theory with an extra spatial dimension. Thus, the three-dimensional Skyrmion lifts to a four-dimensional holographic Skyrmion in the bulk. We begin this review with a description of the simplest example of this correspondence, where the holographic Skyrmion is exactly the self-dual Yang-Mills instanton in flat space. This places an old result of Atiyah and Manton within a holographic framework and reveals that the associated Skyrme model extends the nonlinear pion theory to include an infinite tower of vector mesons, with specific couplings for a BPS theory. We then describe the more complicated curved space version that arises from the string theory construction of Sakai and Sugimoto. The basic concepts remain the same but the technical difficulty increases as the holographic Skyrmion is a curved space version of the Yang-Mills instanton, so self-duality and integrability are lost. Finally, we turn to a low-dimensional analog of holographic Skyrmions, where aspects such as multi-baryons and finite baryon density are amenable to both numerical computation and an approximate analytic treatment.
Kim, Seung Hyup
2008-01-01
Objective To evaluate the correlations between prostate volumes estimated by transabdominal, transrectal, and three-dimensional US and the factors affecting the differences. Materials and Methods The prostate volumes of 94 consecutive patients were measured by both transabdominal and transrectal US. Next, the prostate volumes of 58 other patients was measured by both transrectal and three-dimensional US. We evaluated the degree of correlation and mean difference in each comparison. We also analyzed possible factors affecting the differences, such as the experiences of examiners in transrectal US, bladder volume, and prostate volume. Results In the comparison of transabdominal and transrectal US methods, the mean difference was 8.4 ± 10.5 mL and correlation coefficient (r) was 0.775 (p < 0.01). The experienced examiner for the transrectal US method had the highest correlation (r = 0.967) and the significantly smallest difference (5.4 ± 3.9 mL) compared to the other examiners (the beginner and the trained; p < 0.05). Prostate volume measured by transrectal US showed a weak correlation with the difference (r = 0.360, p < 0.05). Bladder volume did not show significant correlation with the difference (r = -0.043, p > 0.05). The comparison between the transrectal and three-dimensional US methods revealed a mean difference of 3.7 ± 3.4 mL and the correlation coefficient was 0.924 for the experienced examiner. Furthermore, no significant difference existed between examiners (p > 0.05). Prostate volume measured by transrectal US showed a positive correlation with the difference for the beginner only (r = 0.405, p < 0.05). Conclusion In the prostate volume estimation by US, experience in transrectal US is important in the correlation with transabdominal US, but not with three-dimensional US. Also, less experienced examiners' assessment of the prostate volume can be affected by prostate volume itself. PMID:18385560
Narrow-band holographic optical filter using thick efficient holographic gratings
Richard I. Billmers; Elizabeth J. Billmers; Ryszard Burzynski; John F. Weibel; L. H. Heverley; Martin K. Casstevens; Thomas P. Curran; V. Michael Contarino
2002-01-01
RL Associates in conjunction with Hybrid Technologies is developing a narrow linewidth optical filter employing extremely thick volume holographic diffraction gratings. The gratings are written in MEMPLEX, a new holographic materia invented by Laser Photonics Technology, Inc. and licensed to Hybrid Technologies. MEMPLEX has the following characteristics: (1) Excellent optical clarity, (2) Preparable at any thickness up to 10 mm,
Correlations between Regional Brain Volumes and Memory Performance in Anoxia
John S. Allen; Daniel Tranel; Joel Bruss; Hanna Damasio
2006-01-01
This study was aimed at investigating the quantitative relationship between regional brain volumes (hippocampus, amygdala, as well as cerebrum, frontal lobe, parietal lobe, temporal lobe) and performance on anterograde and retrograde memory tests in anoxic patients. We used high-resolution MRI to measure brain volumes in 13 anoxic patients. Neuropsychological testing was conducted contemporaneously with MRI. To control for age and
Fast fluorescence holographic microscopy
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
3D Digital Volume Correlation of Synchrotron Radiation Laminography images of ductile
1 3D Digital Volume Correlation of Synchrotron Radiation Laminography images of ductile crack of measuring 3D displacement fields in the bulk during ductile crack initiation via combined Synchrotron to Tomography, SRCL is a technique that is particularly adapted to obtain in 3D reconstructed volumes of objects
Inuwa, IM; El Mardi, AS
2005-01-01
The aim of this study was to estimate the number and volume distribution of islets of Langerhans in post-weaning young Wistar rat pancreas and their variation with age. Four groups of six normal Wistar Kyoto rats, at 3, 6, 9 and 12 weeks of age, were used. The whole pancreas was weighed (W), fixed in buffered formaldehyde and embedded in JB4 resin, and 1.5-µm serial sections were obtained. A fraction of whole tissue was obtained in accordance with the multistage fractionator principle and used to estimate total number of islets (Nis). Volume fraction (Vf) of islets and volume-weighted mean volume (Vv) of islets were estimated using point-counting and point-sampled intercept methods, respectively. The numbers of islets increased steadily with age (P < 0.001), whereas the volume-weighted mean volume of individual islets was not significantly different among all age groups of rats (P > 0.05). There was a strong positive correlation between total islet number and islet mass (r = 0.96, P = 0.001), and between volume fraction and islet mass (r = 0.969, P = 0.001). However, there was a weak positive correlation between volume fraction and volume-weighted mean islet volume (r = 0.6, P = 0.002) in the age window investigated. These findings indicate that there was an increase in the number and volume fraction of islets with age in post-weaning young rats but that individual islet volume did not change significantly. It appears the mechanism of alteration in islet morphology in the rat is mainly by the formation of new islets while keeping their individual volume distribution unchanged. PMID:15730483
NASA Astrophysics Data System (ADS)
Stoffers, Alexander
This thesis discusses the approach to hadronic scattering at high energies and the description of the pomeron within holographic QCD. Based on a stringy Schwinger mechanism in curved space, the pomeron emerges through the exchange of closed strings between two dipoles and yields Regge behavior for the elastic scattering amplitude. Our holographic result for the dipole-dipole cross section and the wee-dipole density in the conformal limit are shown to be identical in form to the BFKL pomeron result when the non-critical string transverse dimension is D_?=3. Thus, we have obtained an evolution for the wee-dipole density as a function of both rapidity, impact parameter and virtuality. The open string picture allows us to define a local Unruh temperature associated to the scattering process, which is large as the impact parameter is large but small compared to the Hagedorn temperature. Associated with the temperature on the boundary, the Unruh temperature allows us to define the free energy of the system. The induced instanton on the string world-sheet carries entropy for a dipole source of N-ality "k". This stringy entropy is neither coherent nor thermal. We argue that it is released promptly over a time that is solely determined by the impact parameter and the rapidity. It may explain the 3/2 jump in the total charged multiplicities at about 10 participants reported over a wide range of collider energies by PHOBOS. We predict the charged multiplicities in pp, pA and central AA collisions at LHC. The total dipole-dipole cross section is compared to DIS data from HERA and the holographic result for the differential cross section compared to proton-proton and deeply virtual Compton scattering data. With the holographic parameters close to QCD expectations, the holographic results are in reasonable agreement with the data for a variety of observables in the Regge regime.
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…
Holographic photolysis of caged neurotransmitters
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
Killgore, William D S; Olson, Elizabeth A; Weber, Mareen
2013-01-01
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. PMID:24336512
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.
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, and security medium as well. The evolution of holographic optical memories has followed a path not altogether different from holography itself, with several cycles of alternating interest over the past four decades. P. J. van Heerden is widely credited for being the first to elucidate the principles behind holographic data storage in a 1963 paper, predicting bit storage densities on the order of 1/lambda(sup 3) with source wavelength lambda - a fantastic capacity of nearly 1 TB/cu cm for visible light! The science and engineering of such a storage paradigm was heavily pursued thereafter, resulting in many novel hologram multiplexing techniques for dense data storage, as well as important advances in holographic recording materials. Ultimately, however, the lack of such enabling technologies as compact laser sources and high performance optical data I/O devices dampened the hopes for the development of a commercial product. After a period of relative dormancy, successful applications of holography in other arenas sparked a renewed interest in holographic data storage in the late 1980s and the early 1990s. Currently, with most of the critical optoelectronic device technologies in place and the quest for an ideal holographic recording medium intensified, holography is once again considered as one of several future data storage paradigms that may answer our constantly growing need for higher-capacity and faster-access memories.
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.
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.
Correlated Volume?Energy Fluctuations of Phospholipid Membranes: A Simulation Study
2010-01-01
This paper reports all-atom computer simulations of five phospholipid membranes (DMPC, DPPC, DMPG, DMPS, and DMPSH) with focus on the thermal equilibrium fluctuations of volume, energy, area, thickness, and chain order. At constant temperature and pressure, volume and energy exhibit strong correlations of their slow fluctuations (defined by averaging over 0.5 ns). These quantities, on the other hand, do not correlate significantly with area, thickness, or chain order. The correlations are mainly reported for the fluid phase, but we also give some results for the ordered (gel) phase of two membranes, showing a similar picture. The cause of the observed strong correlations is identified by splitting volume and energy into contributions from tails, heads, and water, and showing that the slow volume?energy fluctuations derive from van der Waals interactions of the tail region; they are thus analogous to the similar strong correlations recently observed in computer simulations of the Lennard-Jones and other simple van der Waals type liquids (U. R. Pedersen et al., Phys. Rev. Lett.2008, 100, 015701). The strong correlations reported here confirm one crucial assumption of a recent theory for nerve signal propagation proposed by Heimburg and Jackson (T. Heimburg and A. D. Jackson, Proc. Natl. Acad. Sci.2005, 102, 9790?9795). PMID:20095587
Holographic charge oscillations
NASA Astrophysics Data System (ADS)
Blake, Mike; Donos, Aristomenis; Tong, David
2015-04-01
The Reissner-Nordström black hole provides the prototypical description of a holographic system at finite density. We study the response of this system to the presence of a local, charged impurity. Below a critical temperature, the induced charge density, which screens the impurity, exhibits oscillations. These oscillations can be traced to the singularities in the density-density correlation function moving in the complex momentum plane. At finite temperature, the oscillations are very similar to the Friedel oscillations seen in Fermi liquids. However, at zero temperature the oscillations in the black hole background remain exponentially damped, while Friedel oscillations relax to a power-law.
Gray matter volume correlates of global positive alcohol expectancy in non-dependent adult drinkers.
Ide, Jaime S; Zhang, Sheng; Hu, Sien; Matuskey, David; Bednarski, Sarah R; Erdman, Emily; Farr, Olivia M; Li, Chiang-Shan R
2014-09-01
Alcohol use and misuse is known to involve structural brain changes. Numerous imaging studies have examined changes in gray matter (GM) volumes in dependent drinkers, but there is little information on whether non-dependent drinking is associated with structural changes and whether these changes are related to psychological factors-such as alcohol expectancy-that influence drinking behavior. We used voxel-based morphometry (VBM) to examine whether the global positive scale of alcohol expectancy, as measured by the Alcohol Expectancy Questionnaire-3, is associated with specific structural markers and whether such markers are associated with drinking behavior in 113 adult non-dependent drinkers (66 women). Alcohol expectancy is positively correlated with GM volume of left precentral gyrus (PCG) in men and women combined and bilateral superior frontal gyri (SFG) in women, and negatively correlated with GM volume of the right ventral putamen in men. Furthermore, mediation analyses showed that the GM volume of PCG mediate the correlation of alcohol expectancy and the average number of drinks consumed per occasion and monthly total number of drinks in the past year. When recent drinking was directly accounted for in multiple regressions, GM volume of bilateral dorsolateral prefrontal cortices correlated positively with alcohol expectancy in the combined sample. To our knowledge, these results are the first to identify the structural brain correlates of alcohol expectancy and its mediation of drinking behaviors. These findings suggest that more studies are needed to investigate increased GM volume in the frontal cortices as a neural correlate of alcohol expectancy. PMID:23461484
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
Brower, D.L.; Peebles, W.A.; Rettig, C.L.; Yu, C.X. (Electrical Engineering Department, and Institute of Plasma and Fusion Research, University of California, Los Angeles, California 90024 (United States))
1992-10-01
The spatial resolution of small-angle collective scattering systems is often ambiguous due to the extended length of the scattering volume. By examining two sample volumes at the same wave vector (or scattering angle) that lie along the incident beam, and by varying the separation between these two volumes, one can examine their cross-correlation through use of simple digital signal processing techniques. As the separation between the two volumes is increased, the signals are observed to decorrelate. Application of this technique on the DIII-D and TEXT tokamaks shows that when the volumes are located at the plasma edge and core, the two signals are decorrelated indicating that fluctuations in the plasma core can be resolved.
Analogue holographic correspondence in optical metamaterials
NASA Astrophysics Data System (ADS)
Khveshchenko, D. V.
2015-03-01
We assess the prospects of using metamaterials for simulating various aspects of analogue gravity and holographic correspondence. Albeit requiring a careful engineering of the dielectric media, some hallmark features reminiscent of the hypothetical “generalized holographic conjecture” can be detected by measuring non-local optical field correlations. The possibility of such simulated behavior might also shed light on the true origin of those ostensibly holographic phenomena in the condensed-matter systems with emergent effective metrics which may not, in fact, require any reference to the string-theoretical holography.
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.
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.
Radio Science, Volume ???, Number , Pages 110, Post-correlation ripple removal and RFI rejection for
Ellingson, Steven W.
Radio Science, Volume ???, Number , Pages 110, Post-correlation ripple removal and RFI rejection experiments to date, basic radio frequency inteference (RFI) rejection has been accomplished on a per strong during the daytime, when the Sun acts as a broadband RFI noise source. Here we report on new
Yang, Mino, E-mail: MinoYang@chungbuk.ac.kr [Department of Chemistry, Chungbuk National University, Cheongju, Chungbuk 361-763 (Korea, Republic of)] [Department of Chemistry, Chungbuk National University, Cheongju, Chungbuk 361-763 (Korea, Republic of)
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.
Takeuchi, Shingo
2013-01-01
We propose a holographic model of the SQUID (Superconducting QUantum Interference Device) composed of two Josephson junctions connected each other in a circle with the magnetic flux penetrating the circuit of the SQUID and the supercurrents flowing in both Josephson junction. The gravity in this paper is the Einstein-Maxwell-complex scalar field model on the four-dimensional Anti-de Sitter Schwarzschild black brane geometry in which one space direction is compactified into a circle, and we arrange the profile of the coefficient of the time component of the gauge field having the role for the chemical potential of the cooper pair. The magnetic flux is involved by the rewriting of the surface integral of the magnetic field to the contour integral of the gauge field.
Holographic duality in nonlinear hyperbolic metamaterials
NASA Astrophysics Data System (ADS)
Smolyaninov, Igor I.
2014-07-01
According to the holographic principle, the description of a volume of space can be thought of as encoded on its boundary. Holographic principle establishes equivalence, or duality, between theoretical description of volume physics, which involves gravity, and the gravity-free field theory, which describes physics on its surface. While generally accepted as a theoretical framework, so far there was no known experimental system which would exhibit explicit holographic duality and be amenable to direct experimental testing. Here we demonstrate that nonlinear optics of hyperbolic metamaterials admits such a dual holographic description. Wave equation which describes propagation of extraordinary light through the volume of metamaterial exhibits 2 + 1 dimensional Lorentz symmetry. The role of time in the corresponding effective 3D Minkowski spacetime is played by the spatial coordinate aligned with the optical axis of the material. Nonlinear optical Kerr effect bends this spacetime resulting in effective gravitational interaction between extraordinary photons. On the other hand, a holographic dual theory may be formulated on the metamaterial surface, which describes its nonlinear optics via interaction of cylindrical surface plasmons possessing conserved charges proportional to their angular momenta. Potential implications of this duality for superconductivity of hyperbolic metamaterials are discussed.
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.
Difference Holographic Interferometry: Theory
F. Gyimesi; Z. Füzessy
1988-01-01
Difference holographic interferometry (DHI) has been applied successfully to a wide range of holographic interferometric measurements. Nevertheless, its theory is based only on the simple geometrical optical picture of ‘corresponding points’. The present paper gives a more rigorous wave-optical description of DHI, based on Walles' theory of holographic interferometry. The result is in agreement with the original phase difference formula
Masahiro Yamaguchi; Nagaaki Ohyama; Toshio Honda
1990-01-01
This paper proposes a holographic printer, which produces 3-D hard copies of computer processed objects. For the purpose of automatic making of 3-D hard copies of distortion free, a new method to synthesize holographic stereogram is proposed. It is is flat format and lippmann type holographic stereogram which can be printed by one optical step. The proposed hologram has not
Holographic Mutual Information is Monogamous
Patrick Hayden; Matthew Headrick; Alexander Maloney
2013-02-02
We identify a special information-theoretic property of quantum field theories with holographic duals: the mutual informations among arbitrary disjoint spatial regions A,B,C obey the inequality I(A:BC) >= I(A:B)+I(A:C), provided entanglement entropies are given by the Ryu-Takayanagi formula. Inequalities of this type are known as monogamy relations and are characteristic of measures of quantum entanglement. This suggests that correlations in holographic theories arise primarily from entanglement rather than classical correlations. We also show that the Ryu-Takayanagi formula is consistent with all known general inequalities obeyed by the entanglement entropy, including an infinite set recently discovered by Cadney, Linden, and Winter; this constitutes strong evidence in favour of its validity.
Smitka, M; Puschmann, S; Buschhueter, D; Gerber, J C; Witt, M; Honeycutt, N; Abolmaali, N; Hummel, T
2012-01-16
Both amygdala (AG) and hippocampus (HC) are integral parts of the olfactory system. The present study, including a large number of healthy subjects, was performed to compare HC and AG volumes, measured by manual tracing, in relation to specific olfactory functions, including odor threshold, discrimination, identification, and odor memory tasks. It also aimed to provide age-related normative data about the volume of the HC and AG. A total of 117 healthy volunteers participated (age range 19-77 years, mean age 37 years; 62 women, 55 men). Using the "Sniffin' Sticks", subjects received lateralized tests for odor threshold, and odor discrimination. In addition, an odor memory and an odor identification task were performed bilaterally. A Mini-Mental-State test excluded dementia. MR scans were performed using a 1.5 T scanner for later manual volumetric measurements. Volumetric measurements exhibited a good reproducibility. The average volume for the right HC was 3.29 cm(3) (SD 0.47), for the left HC it was 3.15 cm(3) (SD 0.47). The average right AG had a volume of 1.60 cm(3) (SD 0.31), left 1.59 cm(3) (SD 0.3). Increasing age was accompanied by a decrease of HC and AG volumes, which were much more pronounced for the right compared to the left side. Only the volume of the right HC showed a small but significant correlation with odor threshold (r(117)=0.21; p=0.02). Importantly, this correlation was not mediated by age as indicated by the significant partial correlation when controlling for age (r(114)=0.18; p=0.049). In conclusion, the present data obtained in a relatively large group of subjects demonstrates a small correlation between the volume of the HC, as an integral part of the olfactory system, and smell function. In addition, these data can be used as the basis for normative values of HC and AG volumes, separately for men, women and different age groups. This is of potential interest in diseases with acute or chronic impairment of olfactory function, in metabolic or neurodegenerative diseases or in disorders with damage of areas involved in adult neurogenesis. PMID:21967725
Finite Volume Corrections and Decay of Correlations in the Canonical Ensemble
NASA Astrophysics Data System (ADS)
Pulvirenti, Elena; Tsagkarogiannis, Dimitrios
2015-06-01
We consider a classical system of particles confined in a box interacting via a finite range pair potential. Given the validity of the cluster expansion in the canonical ensemble we compute the error between the finite and the infinite volume free energy and estimate it to be bounded by the area of the surface of the box's boundary over its volume. We also compute the truncated two-point correlation function and find that the contribution from the ideal gas case is of the order plus an exponentially small error with the distance.
Holographic superconductors with various condensates
Horowitz, Gary T.; Roberts, Matthew M. [Department of Physics, UCSB, Santa Barbara, California 93106 (United States)
2008-12-15
We extend earlier treatments of holographic superconductors by studying cases where operators of different dimension condense in both 2+1 and 3+1 superconductors. We also compute a correlation length. We find surprising regularities in quantities such as {omega}{sub g}/T{sub c} where {omega}{sub g} is the gap in the frequency dependent conductivity. In special cases, new bound states arise corresponding to vector normal modes of the dual near-extremal black holes.
NASA Astrophysics Data System (ADS)
Chen, Po-Lin; Cho, Sheng-Lung; Lin, June-Hua; Lin, Shiuan-Huei; Hsu, Ken Y.; Chi, Sien
2012-03-01
Two-wavelength holographic recording in thick phenanthrenequinone-doped poly(methyl methacrylate) photopolymer is demonstrated. By using 325 nm laser as a gating illumination during the holographic recording with 647 nm laser, a volume hologram with diffraction efficiency of ~4% can be recorded in a 2 mm thick sample. In addition, the Bragg selectivity curve with clear sinc nulls is demonstrated. These results support further applications as recording media for volume holographic device with extended spectral response and selective recording property.
Self-correlation fiber specklegram sensor using volume characteristics of speckle patterns
NASA Astrophysics Data System (ADS)
Gómez, Jorge A.; Salazar, Ángel
2012-05-01
Tuning of the dynamic range of a micro-displacement fiber specklegram sensor based on two-wave mixing on a photorefractive material Bi12SiO20 (BSO) and self-correlation operations of speckle patterns is experimentally demonstrated. The high modal interference present in a standard plastic optical fiber (POF) allows generating a Gaussian pattern of subjective speckle, which is recorded in the volume crystal. The volume characteristics of the fiber speckle are changed using a pupil aperture adjacent to the imaging lens of the speckle. A notorious effect of the three dimensional structure of the speckle on the dynamic range of the metrological system is observed, such that, the performance of the sensor can be improved by a simple mechanical action on the pupil aperture. The behavior of the self-correlation loss of the sensor can be adequately described by a squared normalized Bessel function.
Aharony, Ofer [Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot 76100 (Israel); Kutasov, David [EFI and Department of Physics, University of Chicago, Chicago, Illinois 60637 (United States); Lunin, Oleg [Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506 (United States); Sonnenschein, Jacob; Yankielowicz, Shimon [School of Physics and Astronomy, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Ramat Aviv, 69978 (Israel); Albert Einstein Minerva Center, Weizmann Institute of Science, Rehovot 76100 (Israel)
2010-11-15
We study a brane configuration of D4-branes and NS5-branes in weakly coupled type IIA string theory, which describes in a particular limit d=4 N=1 SU(N+p) supersymmetric QCD with 2N flavors and a quartic superpotential. We describe the geometric realization of the supersymmetric vacuum structure of this gauge theory. We focus on the confining vacua of the gauge theory, whose holographic description is given by the MQCD brane configuration in the near-horizon geometry of N D4-branes. This description, which gives an embedding of MQCD into a field theory decoupled from gravity, is valid for 1<
Digital volume correlation: Three-dimensional strain mapping using X-ray tomography
B. K. Bay; T. S. Smith; D. P. Fyhrie; M. Saad
1999-01-01
A three-dimensional extension of two-dimensional digital image correlation has been developed. The technique uses digital image volumes generated through high-resolution X-ray tomography of samples with microarchitectural detail, such as the trabecular bone tissue found within the skeleton. Image texture within the material is used for displacement field measurement by subvolume tracking. Strain fields are calculated from the displacement fields by
Charles Ka Yui Leung; Dandan Feng
2005-01-01
The significant price-trading volume correlation found in the residential property market presents a challenge to the rational expectation hypothesis. Existing theories account for this fact with either capital market imperfection (down-payment effect or loss-aversion consideration) or imperfect information (search theoretic models). This paper employs data from a commercial real estate market, which face a different degree of severity of capital
Ullmer, Brygg
Computational Fluid Dynamics Based Correlation to Find the Final Cement Volume Fraction in Annuli are quantified in the form of a correlation. This correlation is based on a series of Computational Fluid Dynamics (CFD) simulation results. The CFD tool was first validated against experimental results
Computer-generated holographic optical tweezer arrays
Eric R. Dufresne; Gabriel C. Spalding; Matthew T. Dearing; Steven A. Sheets; David G. Grier
2001-01-01
Holographic techniques significantly extend the capabilities of laser tweezing, making possible extended trapping patterns for manipulating large numbers of particles and volumes of soft matter. We describe practical methods for creating arbitrary configurations of optical tweezers using computer-generated diffractive optical elements. While the discussion focuses on ways to create planar arrays of identical tweezers, the approach can be generalized to
Profilometry with volume holographic imaging
Sun, Wenyang
2006-01-01
High resolution, non-contact object profile measurement (profilometry) at long working distance is important in a number of application areas, such as precise parts manufacturing, optical element grounding and polishing, ...
Holographic Entropy Production
Yu Tian; Xiao-Ning Wu; Hongbao Zhang
2014-10-29
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.
Hu Qiang [School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an, Shaanxi 710072 (China); Zeng Xierong [College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060 (China) and Shenzhen Key Laboratory of Special Functional Materials, Shenzhen 518060 (China); Fu, M. W. [Department of Mechanical Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong)
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.
Three Dimensional Holographic Archival Memory
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.
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.
Intracranial pressure pulse waveform correlates with aqueductal cerebrospinal fluid stroke volume
Hamilton, Robert; Baldwin, Kevin; Fuller, Jennifer; Vespa, Paul; Hu, Xiao
2012-01-01
This study identifies a novel relationship between cerebrospinal fluid (CSF) stroke volume through the cerebral aqueduct and the characteristic peaks of the intracranial pulse (ICP) waveform. ICP waveform analysis has become much more advanced in recent years; however, clinical practice remains restricted to mean ICP, mainly due to the lack of physiological understanding of the ICP waveform. Therefore, the present study set out to shed some light on the physiological meaning of ICP morphological metrics derived by the morphological clustering and analysis of continuous intracranial pulse (MOCAIP) algorithm by investigating their relationships with a well defined physiological variable, i.e., the stroke volume of CSF through the cerebral aqueduct. Seven patients received both overnight ICP monitoring along with a phase-contrast MRI (PC-MRI) of the cerebral aqueduct to quantify aqueductal stroke volume (ASV). Waveform morphological analysis of the ICP signal was performed by the MOCAIP algorithm. Following extraction of morphological metrics from the ICP signal, nine temporal ICP metrics and two amplitude-based metrics were compared with the ASV via Spearman's rank correlation. Of the nine temporal metrics correlated with the ASV, only the width of the P2 region (ICP-Wi2) reached significance. Furthermore, both ICP pulse pressure amplitude and mean ICP did not reach significance. In this study, we showed the width of the second peak (ICP-Wi2) of an ICP pulse wave is positively related to the volume of CSF movement through the cerebral aqueduct. This finding is an initial step in bridging the gap between ICP waveform morphology research and clinical practice. PMID:22995390
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
The analysis of Polyakov loop and spin correlators in finite volumes
J. Engels; V. K. Mitrjushkin; T. Neuhaus
1993-11-29
We derive an analytic expression for point to point correlation functions of the Polyakov loop based on the transfer matrix formalism. The contributions from the eigenvalues of the transfer matrix including and beyond the mass gap are investigated both for the $2d$ Ising model and in finite temperature $SU(2)$ gauge theory. We find that the leading matrix element shows similar scaling properties in both models. Just above the critical point we obtain for $SU(2)$ a Debye screening mass $~\\mu_D/T\\approx4~$, independent of the volume. Sorry, figures are not included and can be sent by ordinary mail.
Fluctuations and correlations of conserved charges in an excluded-volume hadron resonance gas model
NASA Astrophysics Data System (ADS)
Bhattacharyya, Abhijit; Das, Supriya; Ghosh, Sanjay K.; Ray, Rajarshi; Samanta, Subhasis
2014-09-01
We present temperature and baryonic chemical potential dependence of higher-order fluctuations and the correlation between conserved charges in an excluded-volume hadron resonance gas model. Products of moments, such as the ratio of variance to mean, product of skewness and standard deviation, product of kurtosis and variance, for the net proton, net kaon, and net charge have been evaluated on the phenomenologically determined freeze-out curve. Further, products of moments for net proton and net charge have been compared with the experimental data measured by the STAR experiment. The dependence of the model result on the hadronic radius parameter has also been discussed.
Kristoufek, Ladislav
2015-01-01
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 insign...
NASA Astrophysics Data System (ADS)
Staraselski, Y.; Brahme, A.; Mishra, R. K.; Inal, K.
2015-01-01
This paper presents the first application of three-dimensional (3D) cross-correlation microstructure reconstruction implemented for a representative volume element (RVE) to facilitate the microstructure engineering of materials. This has been accomplished by developing a new methodology for reconstructing 3D microstructure using experimental two-dimensional electron backscatter diffraction data. The proposed methodology is based on the analytical representation of the generalized form of the two-point correlation function—the distance-disorientation function (DDF). Microstructure reconstruction is accomplished by extending the simulated annealing techniques to perform three term reconstruction with a minimization of the DDF. The new 3D microstructure reconstruction algorithm is employed to determine the 3D RVE containing all of the relevant microstructure information for accurately computing the mechanical response of solids, especially when local microstructural variations influence the global response of the material as in the case of fracture initiation.
Doped Poly(methyl Methacrylate) Photopolymers for Holographic Data Storage
NASA Astrophysics Data System (ADS)
Lin, Shiuan Huei; Lin, June-Hua; Chen, Po-Lin; Shiao, Yi-Nan; Hsu, Ken Y.
In this paper, we report our investigations on thick holographic recording material of the phenanthrenequinone doped poly(methyl methacrylate) (PQ:PMMA) photopolymer. The design strategy and fabrication technique for making thick polymer samples with negligible shrinkage and good optical quality are presented. The physical mechanism for holographic recording in PQ:PMMA material is described, and methods for improving are proposed. Based on these methods, photopolymer samples with different compositions are fabricated and experimentally characterized. The results show that by modifying compositions, the material sensitivity and dynamic range for volume holographic recording have been improved.
Holographic Geometries for Condensed Matter Applications
NASA Astrophysics Data System (ADS)
Keränen, V.; Thorlacius, L.
2015-01-01
Holographic modeling of strongly correlated many-body systems motivates the study of novel spacetime geometries where the scaling behavior of quantum critical systems is encoded into spacetime symmetries. Einstein-Dilaton-Maxwell theory has planar black brane solutions that exhibit Lifshitz scaling and in some cases hyperscaling violation. Entanglement entropy and Wilson loops in the dual field theory are studied by inserting simple geometric probes involving minimal surfaces into the black brane geometry. Coupling to background matter fields leads to interesting low-energy behavior in holographic models, such as U(1) symmetry breaking and emergent Lifshitz scaling.
On Symmetric Signatures Holographic Algorithms
Cai, Jin-Yi
recently introduced a beautiful theory called holographic algorithms. Holographic algorithms are custom nodes. 10 #12;Linear bases transformations The first ingredient of the theory of holographic algorithmsOn Symmetric Signatures in Holographic Algorithms Jin-Yi Cai University of Wisconsin, Madison
Canonical correlation analysis of video volume tensors for action categorization and detection.
Kim, Tae-Kyun; Cipolla, Roberto
2009-08-01
This paper addresses a spatiotemporal pattern recognition problem. The main purpose of this study is to find a right representation and matching of action video volumes for categorization. A novel method is proposed to measure video-to-video volume similarity by extending Canonical Correlation Analysis (CCA), a principled tool to inspect linear relations between two sets of vectors, to that of two multiway data arrays (or tensors). The proposed method analyzes video volumes as inputs avoiding the difficult problem of explicit motion estimation required in traditional methods and provides a way of spatiotemporal pattern matching that is robust to intraclass variations of actions. The proposed matching is demonstrated for action classification by a simple Nearest Neighbor classifier. We, moreover, propose an automatic action detection method, which performs 3D window search over an input video with action exemplars. The search is speeded up by dynamic learning of subspaces in the proposed CCA. Experiments on a public action data set (KTH) and a self-recorded hand gesture data showed that the proposed method is significantly better than various state-of-the-art methods with respect to accuracy. Our method has low time complexity and does not require any major tuning parameters. PMID:19542576
theory "holography" energyradius #12;Holographic Entanglement Entropy: (Ryu & Takayanagi `06) A B AdHolographic (and other) computations of Review of computations of Entanglement Entropy, and its quantity which is (at best) very difficult to measure · in condensed matter theory: diagnostic
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 to treatment. Clinical Trials identifier www.clinicaltrials.gov: NCT00579475, Protocol date: November 2004. http://clinicaltrials.gov/ct2/show/NCT00579475 PMID:24324590
Glebov, Leon
proposed, a single holographic element head-mounted display (HMD) was modeled. Results show that a single in HMD design, but mainly as optical combiners.[3] Volume holographic elements are thick phase gratings, and in section 3 an example of a design of a holographic single element eyepiece for HMD based on such method
Holographic particle image velocimetry measurements in a four-valve combustion engine
NASA Astrophysics Data System (ADS)
van Overbrüggen, Timo; Dannemann, Jan; Klaas, Michael; Schröder, Wolfgang
2014-01-01
This is a feasibility study to show that the nonreacting three-dimensional flow in the cylinder of a four-valve internal combustion engine at 160° after top dead center (atdc) at 1,500 rpm can be accurately measured by holographic particle image velocimetry. The results evidence the quality of holographic PIV measurements in engine flows and the capability of the holographic method to instantaneously capture the complete three-dimensional flow field in a large area of the highly intricate cylinder flow. The resolved measurement volume has a diameter of about 60 mm and a height of 80 mm with a vector spacing of 0.75 mm per vector. To validate the measurements, the flow structure as well as the turbulent kinetic energy of the flow field is compared with planar two-component/two-dimensional (2C/2D-PIV) measurements performed in the same engine (Dannemann et al., in Exp Fluids 2010). Furthermore, the spatial propagation of the flow field as well as the vortical structures is visualized by 3D streamlines and ? 2-contours. The current results confirm the existence of several large-scale flow structures, such as a counter-rotating ring-vortex pair below the inlet valve and the tumble vortex. The latter possesses a U-shaped propagation of the vortex core. The analysis of the two-point correlation shows the integral length scale to be in the range 2.5-6.1 mm, which is in agreement with literature data.
YANG, JIANG-CUN; SUN, YANG; XU, CUI-XIANG; DANG, QIAN-LI; LI, LING; XU, YONG-GANG; SONG, YAO-JUN; YAN, HONG
2015-01-01
This study aimed to explore the correlation between red blood cell (RBC) transfusion volume and patient mortality in massive blood transfusion. A multicenter retrospective study was carried out on 1,601 surgical inpatients who received massive blood transfusion in 20 large comprehensive hospitals in China. According to RBC transfusion volume and duration, the patients were divided into groups as follows: 0–4, 5–9, 10–14, 15–19, 20–24, 25–29, 30–39 and ?40 units within 24 or 72 h. Mortality in patients with different RBC transfusion volumes was analyzed. It was found that patient mortality increased with the increase in the volume of RBC transfusion when the total RBC transfusion volume was ?10 units within 24 or 72 h. Survival analysis revealed significant differences in mortality according to the RBC transfusion volume (?2=72.857, P<0.001). Logistic regression analysis revealed that RBC transfusion volume is an independent risk factor [odds ratio (OR) = 0.52; confidence interval (CI): 0.43–0.64; P<0.01] for the mortality of patients undergoing a massive blood transfusion. When RBCs were transfused at a volume of 5–9 units within 24 and 72 h, the mortality rate was the lowest, at 3.7 and 2.3% respectively. It is concluded that during massive blood transfusion in surgical inpatients, there is a correlation between RBC transfusion volume within 24 or 72 h and the mortality of the patients. Patient mortality increases with the increase in the volume of RBC transfusion. RBC transfusion volume, the length of stay at hospital and intensive care unit stay constitute the independent risk factors for patient mortality. PMID:25452789
Dynamic volume vs respiratory correlated 4DCT for motion assessment in radiation therapy simulation
Coolens, Catherine; Bracken, John; Driscoll, Brandon; Hope, Andrew; Jaffray, David [Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario M5G 2M9, Canada and Department of Radiation Oncology, University of Toronto, Toronto, Ontario M5S 3S2 (Canada); Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario M5G 2M9 (Canada); Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario M5G 2M9, Canada and Department of Radiation Oncology, University of Toronto, Toronto, Ontario M5S 3S2 (Canada); Radiation Medicine Program, Princess Margaret Hospital, Toronto, Ontario M5G 2M9 (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario M5S 3S2 (Canada) and Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5G 2M9 (Canada)
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 significantly different PDF from the ground truth, especially for smaller tumors (cross-correlation ranging between 0.04 and 0.69). For the protocols studied, the dose measurements were higher in the 4D{sub vol} CT method (40%), but it was shown that significant mAs reductions can be achieved by a factor of 4-5 while maintaining image quality and accuracy. Conclusions: 4D{sub vol} CT using a scanner with a large cone-angle is a promising alternative for improving the accuracy with which respiration-induced motion can be characterized, particularly for patients with irregular breathing motion. This approach also generates 4DCT image data with a reduced total scan time compared to a RCCT scan, without the need for image binning or external respiration signals within the 16 cm scan length. Scan dose can be made comparable to RCCT by optimization of the scan parameters. In addition, it provides the possibility of measuring breathing motion for more than one breathing cycle to assess stability and obtain a more accurate motion PDF, which is currently not feasible with the conventional RCCT approach.
Grier, David G; Roichman, Yael
2006-02-10
Holographic optical tweezers use computer-generated holograms to create arbitrary three-dimensional configurations of single-beam optical traps that are useful for capturing, moving, and transforming mesoscopic objects. Through a combination of beam-splitting, mode-forming, and adaptive wavefront correction, holographic traps can exert precisely specified and characterized forces and torques on objects ranging in size from a few nanometers to hundreds of micrometers. Offering nanometer-scale spatial resolution and real-time reconfigurability, holographic optical traps provide unsurpassed access to the microscopic world and have found applications in fundamental research, manufacturing, and materials processing. PMID:16512529
Grier, David G.; Roichman, Yael
2006-02-10
Holographic optical tweezers use computer-generated holograms to create arbitrary three-dimensional configurations of single-beam optical traps that are useful for capturing, moving, and transforming mesoscopic objects. Through a combination of beam-splitting, mode-forming, and adaptive wavefront correction, holographic traps can exert precisely specified and characterized forces and torques on objects ranging in size from a few nanometers to hundreds of micrometers. Offering nanometer-scale spatial resolution and real-time reconfigurability, holographic optical traps provide unsurpassed access to the microscopic world and have found applications in fundamental research, manufacturing, and materials processing.
Testicular volume is inversely correlated with nurturing-related brain activity in human fathers
Mascaro, Jennifer S.; Hackett, Patrick D.; Rilling, James K.
2013-01-01
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
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.
Phenanthrenequinone-doped copolymers for holographic data storage
NASA Astrophysics Data System (ADS)
Lin, Shiuan Huei; Chen, Po-Lin; Lin, June-Hwa
2009-03-01
Two new types of phenanthrenequinone-doped poly(methyl-methacrylate) (PQ/PMMA) are proposed and fabricated for volume holographic recording. In these materials, the matrix of PQ/PMMA is replaced by the copolymers, which are composed of either poly(trimethylolpropane triacrylate-co-methyl methacrylate) or poly(2-phenoxyethyl acrylate-co-methyl methacrylate), respectively. With the chemical analyses of the response of these materials with respect to light exposure, the physical mechanism of the holographic recording in those copolymer samples is investigated. In addition, the holographic characteristics, including the dynamic range and sensitivity, have been measured. The experimental results demonstrate that the modification of the monomer components can enhance holographic characteristics of PQ/PMMA.
Making of a holographic movie on film: from holographic animation to holographic movie
NASA Astrophysics Data System (ADS)
Hiyama, Shigeo; Higuchi, Kazuhito; Ishii, Ken'ichiro; Ishikawa, Jun; Ohara, Tomoko; Muraho, Shuji
1995-04-01
Throughout `EI' '92, '93, '94 and '95, we have been presenting an experimental holographic movie system as a tool to estimate the picture quality of moving holographic images as a step towards holographic TV. Therefore these presentations can be seen as experiments for holographic movie system. They present holographic move devices as well as instruction on how to make holographic movies on film. Holographic movies are possible as we will report in this presentation. Throughout holographic movie devices I, II, III and IV, the same equipment and technology has been used. This will be recognized and appreciated by holographic researchers. Nowadays to record holographic images, it is best to use holographic film (in the case of animation, there is no other method). Through this method in each new version, we have been trying to broaden our expressions and artist's image in using new technology and take a further step for better holographic movies on film. In the future holographic movies will become popular. But now in their research phase we are working on animated movies as not only an presentation of technique but also as an artist's expression as well. We are making these technology with the general concept and intention of appealing to the senses of all people. These are not only holographic animation pieces but also 3D sounds and a construction of images in time. We have approached this concept with a most positive attitude.
Bao, Ning; Ooguri, Hirosi; Stoica, Bogdan; Sully, James; Walter, Michael
2015-01-01
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, w...
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.
Brian Batell; Tony Gherghetta
2007-01-01
We compute the precise elementary\\/composite field content of mass eigenstates in holographic duals of warped models in a slice of AdS. 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
J. D. Valentine
1968-01-01
CLAIMS by Longuet-Higgins1 and Greguss2 that memory might behave holographically are tested here in a situation of prompted visual recall. If a figure, of area f, is inspected by a subject (S) and subsequently a part (P) of that figure, of area p, is presented to him, the holographic theory implies that as the ratio p\\/f increases, the strength of
Brian Batell; Tony Gherghetta
2007-01-01
We compute the precise elementary\\/composite field content of mass eigenstates in holographic duals of warped models in a slice of AdS5. 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
A Simple Holographic Insulator
Eric Mefford; Gary T. Horowitz
2014-07-11
We present a simple holographic model of an insulator. Unlike most previous holographic insulators, the zero temperature infrared geometry is completely nonsingular. Both the low temperature DC conductivity and the optical conductivity at zero temperature satisfy power laws with the same exponent, given by the scaling dimension of an operator in the IR. Changing a parameter in the model converts it from an insulator to a conductor with a standard Drude peak.
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/(8?) 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.
Bushby, Andrew J; Mariggi, Giovanni; Armer, Hannah E J; Collinson, Lucy M
2012-01-01
The study of a biological event within a live model organism has become routine through the use of fluorescent labeling of specific proteins in conjunction with laser confocal imaging. These methods allow 3D visualization of temporal events that can elucidate biological function but cannot resolve the tissue organization, extracellular and subcellular details of the tissues. Here, we present a method for correlating electron microscopy image data with the light microscopy data from the same sample volume to reveal the 3D structural information: "correlative light and volume electron microscopy." The methods for live video confocal microscopy, fixation and embedding of the tissue for electron microscopy, the focused ion beam scanning electron microscopy method for sequentially slicing and imaging the volume of interest, and the treatment of the resulting 3D dataset are presented. The method is illustrated with data collected during the angiogenesis of blood vessels in a transgenic zebrafish embryo. PMID:22857937
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.
Cosmological 3-point correlators from holography
McFadden, Paul; Skenderis, Kostas, E-mail: P.L.McFadden@uva.nl, E-mail: K.Skenderis@uva.nl [Institute for Theoretical Physics, Science Park 904, 1090 GL Amsterdam (Netherlands)
2011-06-01
We investigate the non-Gaussianity of primordial cosmological perturbations using holographic methods. In particular, we derive holographic formulae that relate all cosmological 3-point correlation functions, including both scalar and tensor perturbations, to stress-energy correlation functions of a holographically dual three-dimensional quantum field theory. These results apply to general single scalar inflationary universes that at late times approach either de Sitter spacetime or accelerating power-law cosmologies. We further show that in Einstein gravity all 3-point functions involving tensors may be obtained from correlators containing only positive helicity gravitons, with the ratios of these to the correlators involving one negative helicity graviton being given by universal functions of momenta, irrespectively of the potential of the scalar field. As a by-product of this investigation, we obtain holographic formulae for the full 3-point function of the stress-energy tensor along general holographic RG flows. These results should have applications in a wider holographic context.
Epicardial fat volume is correlated with coronary lesion and its severity
Bo, Xiaohong; Ma, Likun; Fan, Jili; Jiang, Zhe; Zhou, Yuansong; Zhang, Lei; Li, Wanjun
2015-01-01
Objective: To evaluate the correlation of epicardial adipose tissue volume (EATV) with the coronary artery lesion and its severity. Methods: Inpatients with suspicious stable angina of coronary heart lesion were recruited. For patients with coronary artery lesions in CTA, further coronary angiography (CAG) was performed to evaluate the coronary artery lesion. Gensini scoring system was employed to assess the severity of coronary artery lesions. Results: Patients were classified as coronary heart disease (CHD) group (n = 160). Results showed the mean EATV was 192.57 ± 30.32 cm3 in CHD group, which was significantly larger than that in control group (138.56 ± 23.18 cm3; P < 0.01). The coronary artery stenosis was classified as mild, moderate and severe stenosis according to the extent of coronary artery lesions, and results showed marked difference in the EATV among patients with different severities of coronary artery stenosis (P < 0.005). The Gensini score was positively related to EATV (r = 0.285, P = 0.000). The EATV increased with the increase in the number of affected coronary arteries. Multivariate Logistic regression analysis showed EATV was an independent risk factor of CHD after adjusting other confounding factors (OR = 1.023, P = 0.013). Conclusion: EATV is closely related to the severity of coronary artery lesions: the larger the EATV, the more severe the coronary artery lesions. Moreover, EATV is an independent risk factor of CHD.
Geijer, Cecilia; Medrala-Klein, Dagmara; Petelenz-Kurdziel, Elzbieta; Ericsson, Abraham; Smedh, Maria; Andersson, Mikael; Goksör, Mattias; Nadal-Ribelles, Mariona; Posas, Francesc; Krantz, Marcus; Nordlander, Bodil; Hohmann, Stefan
2013-08-01
The control of activity and localization of transcription factors is critical for appropriate transcriptional responses. In eukaryotes, signal transduction components such as mitogen-activated protein kinase (MAPK) shuttle into the nucleus to activate transcription. It is not known in detail how different amounts of nuclear MAPK over time affect the transcriptional response. In the present study, we aimed to address this issue by studying the high osmolarity glycerol (HOG) system in Saccharomyces cerevisiae. We employed a conditional osmotic system, which changes the period of the MAPK Hog1 signal independent of the initial stress level. We determined the dynamics of the Hog1 nuclear localization and cell volume by single-cell analysis in well-controlled microfluidics systems and compared the responses with the global transcriptional output of cell populations. We discovered that the onset of the initial transcriptional response correlates with the potential of cells for rapid adaptation; cells that are capable of recovering quickly initiate the transcriptional responses immediately, whereas cells that require longer time to adapt also respond later. This is reflected by Hog1 nuclear localization, Hog1 promoter association and the transcriptional response, but not Hog1 phosphorylation, suggesting that a presently uncharacterized rapid adaptive mechanism precedes the Hog1 nuclear response. Furthermore, we found that the period of Hog1 nuclear residence affects the amplitude of the transcriptional response rather than the spectrum of responsive genes. PMID:23758973
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.
Evolution of holographic entanglement entropy in an anisotropic system
Ecker, Christian; Stricker, Stefan A
2015-01-01
We determine holographically 2-point correlators of gauge invariant operators with large conformal weights and entanglement entropy of strips for a time-dependent anisotropic 5-dimensional asymptotically anti-de Sitter spacetime. At the early stage of evolution where geodesics and extremal surfaces can extend beyond the apparent horizon all observables vary substantially from their thermal value, but thermalize rapidly. At late times we recover quasi-normal ringing of correlators and holographic entanglement entropy around their thermal values, as expected on general grounds. We check the behaviour of holographic entanglement entropy and correlators as function of the separation length of the strip and find agreement with the exact expressions derived in the small and large temperature limits.
Periodically Driven Holographic Superconductor
Wei-Jia Li; Yu Tian; Hongbao Zhang
2013-06-21
As a first step towards our holographic investigation of the far-from-equilibrium physics of periodically driven systems at strong coupling, we explore the real time dynamics of holographic superconductor driven by a monochromatically alternating electric field with various frequencies. As a result, our holographic superconductor is driven to the final oscillating state, where the condensate is suppressed and the oscillation frequency is controlled by twice of the driving frequency. In particular, in the large frequency limit, the three distinct channels towards the final steady state are found, namely under damped to superconducting phase, over damped to superconducting and normal phase, which can be captured essentially by the low lying spectrum of quasi-normal modes in the time averaged approximation, reminiscent of the effective field theory perspective.
Periodically Driven Holographic Superconductor
Li, Wei-Jia; Zhang, Hongbao
2013-01-01
As a first step towards our holographic investigation of the far-from-equilibrium physics of periodically driven systems at strong coupling, we explore the real time dynamics of holographic superconductor driven by a monochromatically alternating electric field with various frequencies. As a result, our holographic superconductor is driven to the final oscillating state, where the condensate is suppressed and the oscillation frequency is controlled by twice of the driving frequency. In particular, in the large frequency limit, the three distinct channels towards the final steady state are found, namely under damped to superconducting phase, over damped to superconducting and normal phase, which can be captured essentially by the low lying spectrum of quasi-normal modes in the time averaged approximation, reminiscent of the effective field theory perspective.
NSDL National Science Digital Library
Anderson-Cook, C.
The applets, created by Virginia Tech's Department of Statistics, allow you to see how different bivariate data look under different correlation structures. The "Movie" applet either creates data for a particular correlation or animates a multitude data sets ranging correlations from -1 to 1. The "Creation" applet allows the user to create a data set by adding or deleting points from the screen.
Holographic probes of collapsing black holes
NASA Astrophysics Data System (ADS)
Hubeny, Veronika E.; Maxfield, Henry
2014-03-01
We continue the programme of exploring the means of holographically decoding the geometry of spacetime inside a black hole using the gauge/gravity correspondence. To this end, we study the behaviour of certain extremal surfaces (focusing on those relevant for equal-time correlators and entanglement entropy in the dual CFT) in a dynamically evolving asymptotically AdS spacetime, specifically examining how deep such probes reach. To highlight the novel effects of putting the system far out of equilibrium and at finite volume, we consider spherically symmetric Vaidya-AdS, describing black hole formation by gravitational collapse of a null shell, which provides a convenient toy model of a quantum quench in the field theory. Extremal surfaces anchored on the boundary exhibit rather rich behaviour, whose features depend on dimension of both the spacetime and the surface, as well as on the anchoring region. The main common feature is that they reach inside the horizon even in the post-collapse part of the geometry. In 3-dimensional spacetime, we find that for sub-AdS-sized black holes, the entire spacetime is accessible by the restricted class of geodesics whereas in larger black holes a small region near the imploding shell cannot be reached by any boundary-anchored geodesic. In higher dimensions, the deepest reach is attained by geodesics which (despite being asymmetric) connect equal time and antipodal boundary points soon after the collapse; these can attain spacetime regions of arbitrarily high curvature and simultaneously have smallest length. Higher-dimensional surfaces can penetrate the horizon while anchored on the boundary at arbitrarily late times, but are bounded away from the singularity. We also study the details of length or area growth during thermalization. While the area of extremal surfaces increases monotonically, geodesic length is neither monotonic nor continuous.
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.
Holographic experiments in space
NASA Astrophysics Data System (ADS)
Gorevich, S.
1982-03-01
Experiments conducted on board the Salyut-6 station to demonstrate the suitability and efficiency of the holographic method and television equipment are discussed. The holographic method is of great value to aerospace sciences. It can gather a large amount of information within a short time onboard an orbital station. The information content per exposure is increased and a three dimensional or phased information is obtained. The performance of a series of experiments by the station crew requires continuous participation and monitoring by specialists in a narrow scientific discipline and by technicians on Earth. The activities can be enhanced when television transmitted images are three dimensional.
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 ? mesons, tensor couplings are found to be dominant. We close with various cautionary comments and speculations.
A note on the extensivity of the holographic entanglement entropy
José L. F. Barbón; Carlos A. Fuertes
2008-01-01
We consider situations where the renormalized geometric entropy, as defined by the AdS\\/CFT ansatz of Ryu and Takayanagi, shows extensive behavior in the volume of the entangled region. In general, any holographic geometry that is `capped' in the infrared region is a candidate for extensivity provided the growth of minimal surfaces saturates at the capping region, and the induced metric
Conically scanned lidar telescope using holographic optical elements
Geary K. Schwemmer; Thomas D. Wilkerson
1992-01-01
Holographic optical elements (HOE) using volume phase holograms make possible a new class of lightweight scanning telescopes having advantages for lidar remote sensing instruments. So far, the only application of HOE's to lidar has been a non-scanning receiver for a laser range finder. We introduce a large aperture, narrow field of view (FOV) telescope used in a conical scanning configuration,
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
Fu, Jiawei; Pierron, Fabrice; Ruiz, Pablo D
2013-12-01
This paper presents a methodology for stiffness identification from depth-resolved three-dimensional (3-D) full-field deformation fields. These were obtained by performing digital volume correlation on optical coherence tomography volume reconstructions of silicone rubber phantoms. The effect of noise and reconstruction uncertainties on the performance of the correlation algorithm was first evaluated through stationary and rigid body translation tests to give an indication of the minimum strain that can be reliably measured. The phantoms were then tested under tension, and the 3-D deformation fields were used to identify the elastic constitutive parameters using a 3-D manually defined virtual fields method. The identification results for the cases of uniform and heterogeneous strain fields were compared with those calculated analytically through the constant uniaxial stress assumption, showing good agreement. PMID:24346854
H. S. Soininen; J. Karhu; J. Partanen; A. Pääkkönen; V. Jousmäki; T. Hänninen; M. Hallikainen; K. Partanen; M. P. Laakso; K. Koivisto; P. J. Riekkinen
1995-01-01
We studied the habituation of auditory N100 responses in subjects with age-associated memory impairment (AAMI) and in healthy age-matched volunteers. The findings were correlated with volumes of the amygdala, hippocampus, and frontal lobe measured by magnetic resonance imaging (MRI), as well as with subjects' performance on tests assessing frontal lobe functions and memory. Habituation of N100 did not differ aacros
Su C. Tsay; Haim Grebel
1994-01-01
We present a new type of planar optical interconnects; the transverse holograms. With this type of interconnect, one dimensional, input light distribution is converted into a one dimensional output light distribution via holographic pattering along the direction of the optical wave propagation.
Ning Bao; Sepehr Nezami; Hirosi Ooguri; Bogdan Stoica; James Sully; Michael Walter
2015-05-28
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.
Gerard't Hooft
2000-01-01
After a pedagogical overview of the present status of High-Energy Physics,\\u000asome problems concerning physics at the Planck scale are formulated, and an\\u000aintroduction is given to a notion that became known as ``the holographic\\u000aprinciple\\
Dynamic particle holographic instrument
Guozhi Wang; San Feng; Zhengrong Wang; Shuyan Wang
1991-01-01
The sizes, distributions, and speeds of sprayed particles can be ascertained under various circumstances through the use of the in-line\\/off-axis holography and sequential pulse laser system discussed. The optical system used is of multifunctional architecture, allowing either the making of a reflecting object's hologram or serving as a holographic interferometer for transparent objects and fluid fields. The light source used
Microwave holographic interferometry
G. Papi; V. Russo; S. Sottini
1971-01-01
Microwave holography is an extension of the optical holography to the microwave field. In fact, by using a well-known characteristic of the holographic process, it is possible to record the hologram at frequencies very far from the optical region (microwave) and to reconstruct a visible image by laser light. This paper describes the experimental apparatus and the technique used for
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.
NASA Astrophysics Data System (ADS)
Nawa, Kanabu; Suganuma, Hideo; Kojo, Toru
2007-04-01
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 ? 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 Nc, without small amplitude expansion of meson fields to discuss chiral solitons. For the hedgehog configuration of pion and ?-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 ?-meson profile G˜(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 ? mesons. We analyze interaction terms of pions and ? mesons in brane-induced Skyrmion, and find a significant ?-meson component appearing in the core region of a baryon.
Primordial perturbation spectra in a holographic phase of the Universe
Piao Yunsong [College of Physical Sciences, Graduate School of Chinese Academy of Sciences, YuQuan Road 19A, Beijing 100049 (China)
2007-08-15
In this paper, I suppose that the Universe begins in a holographic thermal equilibrium phase with the diverged correlation length, and the phase transition to the radiation phase of standard cosmology goes with the abrupt reduction of correlation length. In this case, the primordial perturbations may be induced by thermal fluctuations in this holographic phase. I calculate the spectra of these holographic primordial perturbations and find that the scalar spectrum has a slightly red tilt and the tensor perturbation amplitude has a moderate ratio, which may be tested in coming observations. The results plotted in the r-n{sub s} plane are similar to that of large field inflation models. However, for fixed efolding number, they are generally in different positions.
Lens design for holographic data storage systems
NASA Astrophysics Data System (ADS)
Wang, Ye; Liu, Changjiang; Wan, Yuhong; Tao, Shiquan
2005-02-01
A pair of cascade lenses, a Fourier-transform lens and an imaging lens, is the key component in a volume holographic data-storage system (HDSS) for writing in and reading out the information in holographic recording material respectively. For a high-density holographic data-storage system, performances of these lenses are critical. In order to obtain precise input and output information, and reduce the bit-error rate in the retrieved data, the accurate pixel matching between the whole high-resolution page of SLM and CCD must be ensured. To meet these requirements, in this paper the design of this lens is discussed in detail. In this paper we designed the lenses of unsymmetrical structure and compact profile, and the maximal image distortion of the lens less than 0.01%, and the MTF value at the spatial frequency 40 LP/mm greater than 0.5 over the whole view-field. Other aberrations such as spherical aberration, field curvature, comatic were well corrected. The lens can realize pixel matching between 1024x768 of SLM and CCD. Furthermore, the effect of the manufacture accuracy of the lens on its image quality was analyzed, based on which the optimum parameters and manufacture/assembly tolerance are given.
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…
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.
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.
Anes, Mauricio; Kohmann, Andre de Moura; Souza, Ana Claudia Mércio Loredo; 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?mm3, 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.
Luders, Eileen; Toga, Arthur W.; Lepore, Natasha; Gaser, Christian
2011-01-01
Although the systematic study of meditation is still in its infancy, research has provided evidence for meditation-induced improvements in psychological and physiological well-being. Moreover, meditation practice has been shown not only to benefit higher-order cognitive functions but also to alter brain activity. Nevertheless, little is known about possible links to brain structure. Using high-resolution MRI data of 44 subjects, we set out to examine the underlying anatomical correlates of long-term meditation with different regional specificity (i.e., global, regional, and local). For this purpose, we applied voxel-based morphometry in association with a recently validated automated parcellation approach. We detected significantly larger gray matter volumes in meditators in the right orbito-frontal cortex (as well as in the right thalamus and left inferior temporal gyrus when co-varying for age and/or lowering applied statistical thresholds). In addition, meditators showed significantly larger volumes of the right hippocampus. Both orbito-frontal and hippocampal regions have been implicated in emotional regulation and response control. Thus, larger volumes in these regions might account for meditators’ singular abilities and habits to cultivate positive emotions, retain emotional stability, and engage in mindful behavior. We further suggest that these regional alterations in brain structures constitute part of the underlying neurological correlate of long-term meditation independent of a specific style and practice. Future longitudinal analyses are necessary to establish the presence and direction of a causal link between meditation practice and brain anatomy. PMID:19280691
Lensless matched spatial filter correlator experiments
NASA Technical Reports Server (NTRS)
Shen, M.; Casasent, D.; Luu, T. K.; Feng, B.
1980-01-01
By combining a matched spatial filter and holographic optical element on a single plate, a compact optical frequency plane correlator results. Experimental pattern recognition correlation data and a theoretical analysis with experimental verification of the system's shift invariance are provided.
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.
Transport in holographic superfluids
Christopher P. Herzog; Nir Lisker; Piotr Surowka; Amos Yarom
2011-01-17
We construct a slowly varying space-time dependent holographic superfluid and compute its transport coefficients. Our solution is presented as a series expansion in inverse powers of the charge of the order parameter. We find that the shear viscosity associated with the motion of the condensate vanishes. The diffusion coefficient of the superfluid is continuous across the phase transition while its third bulk viscosity is found to diverge at the critical temperature. As was previously shown, the ratio of the shear viscosity of the normal component to the entropy density is 1/(4 pi). As a consequence of our analysis we obtain an analytic expression for the backreacted metric near the phase transition for a particular type of holographic superfluid.
Thompson, Paul
brain volumes and (1) demographic variables: age, sex (2) immune system measures: current and nadir CD4 in the frontal white matter are correlated with regional white matter volumes (FDR q=0.05, critical P=0.03) Brain, but the brain changes underlying this cognitive decline are still poorly understood. In patients with HIV
Industrial and scientific applications of holographic measurements
NASA Astrophysics Data System (ADS)
Ginzburg, Vera M.
1997-05-01
The primary mission of the Holography Laboratory organized at the Opto-Physical Research Institute (YNIIOFI, Moscow, Russia) in 1966 was application of holography techniques in metrology [1]. The following basic tasks have been successfully accomplished [2-4]: (i) theoretical analysis of sources of measurement errors; (ii) development and batch production of optical holographic devices and reference instruments for their legal certification; (iii) development of methods and means for processing measurement data; specifically, the Radon transformation is applied for calculation of spatial distribution of refractive index in transparent objects; (iv) a method and device for stroboscopic measuring of 3D reconstructed images by a "periscope" technique; (v) utilization of holographic tomography and laser interferometry; (vi) instrumentation for microwave and ultrasonic holographometry, correlation-based techniques for rejection of imperfect products and for analysis ofpulsed signals. The developed holographic instrumentation has found widespread application at various scientific and industrial enterprises in the former Soviet Union and Eastern European countries. This report represents only a small selection of the total body of work accomplished in the laboratory.
Biopolymer holographic diffraction gratings
Svetlana Savi? Ševi?; Dejan Pantelic
2008-01-01
Surface-relief diffraction gratings are holographically recorded in dextran sensitized with ammonium dichromate (DCD). DCD was exposed with single-frequency 200mW diode pumped ND-YAG laser, at 532nm. The diffraction grating profiles were analyzed by atomic force microscopy (AFM). It was found that different surface profiles could be obtained. Gratings with 330lines\\/mm spatial frequencies were made. Existence of higher harmonics in Fourier Transform
Holographic Coulomb branch vevs
NASA Astrophysics Data System (ADS)
Skenderis, Kostas; Taylor, Marika
2006-08-01
We compute holographically the vevs of all chiral primary operators for supergravity solutions corresponding to the Coulomb branch of Script N = 4 SYM and find exact agreement with the corresponding field theory computation. Using the dictionary between 10d geometries and field theory developed to extract these vevs, we propose a gravity dual of a half supersymmetric deformation of Script N = 4 SYM (on Mink4) by certain irrelevant operators.
Introduction to Holographic Superconductors
Gary T. Horowitz
\\u000a These lectures give an introduction to the theory of holographic superconductors. These are superconductors that have a dual\\u000a gravitational description using gauge\\/gravity duality. After introducing a suitable gravitational theory, we discuss its properties\\u000a in various regimes: the probe limit, the effects of backreaction, the zero temperature limit, and the addition of magnetic\\u000a fields. Using the gauge\\/gravity dictionary, these properties reproduce
Jan de Boer; Kyriakos Papadodimas; Erik Verlinde
2009-07-23
We construct in the context of the AdS/CFT correspondence degenerate composite operators in the conformal field theory that are holographically dual to degenerate stars in anti de Sitter space. We calculate the effect of the gravitational back-reaction using the Tolman-Oppenheimer-Volkoff equations, and determine the "Chandrasekhar limit" beyond which the star undergoes gravitational collapse towards a black hole.
NASA Astrophysics Data System (ADS)
Chen, H.; Peng, Q.; Huang, Y. Y.; Zhang, R.; Mallon, P. E.; Zhang, J.; Li, Y.; Wu, Y.; Richardson, J. R.; Sandreczki, T. C.; Jean, Y. C.; Suzuki, R.; Ohdaira, T.
2002-06-01
The mechanical durability of seven commercially polymeric coatings is investigated using slow positron beam techniques to monitor changes in sub-nanometer defects during the process of cyclic loading. Doppler broadened energy spectra and positron annihilation lifetime (PAL) measurements were performed as a function of the slow positron energy at different periods of cycling loading. The positron annihilation dada show that both S-defect parameter and o-positronium (Ps) lifetime decrease as the loading cycle increases. The results indicate a loss of free volumes due to the loss of mechanical durability by cyclic loading. A direct correlation between the loss of S-defect parameter and the period of loading cycle is observed. This is interpreted as that durability of polymeric coatings is controlled by the atomic level free volumes. It is shown that the slow positron beam is a very successful probe in detecting the very early stages of coating degradation due to mechanical processes.
Direct laser writing defects in holographic lithography-created photonic lattices
NASA Astrophysics Data System (ADS)
Sun, Hong-Bo; Nakamura, Atsushi; Kaneko, Koshiro; Shoji, Satoru; Kawata, Satoshi
2005-04-01
As a well-established laser fabrication approach, holographic lithography, or multibeam interference patterning, is known for its capability to create long-range ordered large-volume photonic crystals (PhCs) rapidly. Its broad use is, however, hampered by difficulty in inducing artificially designed defects for device functions. We use pinpoint femtosecond laser ablation to remove and two-photon photopolymerization to add desired defective features to obtain photonic acceptors and photonic donors, respectively, in an otherwise complete PhC matrix produced by holographic lithography. The combined use of the two direct laser writing technologies would immediately make holographic lithography a promising industrial tool for PhC manufacture.
Characteristics of a dynamic holographic sensor for shape control of a large reflector
NASA Technical Reports Server (NTRS)
Welch, Sharon S.; Cox, David E.
1991-01-01
Design of a distributed holographic interferometric sensor for measuring the surface displacement of a large segmented reflector is proposed. The reflector's surface is illuminated by laser light of two wavelengths and volume holographic gratings are formed in photorefractive crystals of the wavefront returned from the surface. The sensor is based on holographic contouring with a multiple frequency source. It is shown that the most stringent requirement of temporal stability affects both the temporal resolution and the dynamic range. Principal factor which limit the sensor performance include the response time of photorefractive crystal, laser power required to write a hologram, and the size of photorefractive crystal.
Two-step phase-shifting fluorescence incoherent holographic microscopy
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
Method and apparatus for holographic wavefront diagnostics
Toeppen, John S. (Livermore, CA)
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.
Computational Complexity Theory Holographic Algorithms
Cai, Jin-Yi
Computational Complexity Theory and Holographic Algorithms Jin-Yi Cai University of Wisconsin foundation of Computability Theory was established in the 1930s, . . . Answering a question of Hilbert 2 #12;Valiant's Holographic Algorithms Similar to "quantum" superposition, but without using "quantum computers
Optical fiber holographic speckle interferometry
Guozhi Wang
1993-01-01
Pulsed laser is transmitted by optical fibers, the polarity is changed into random distribution and the coherence is decreased somewhat. But when used in holographic interferometry, optical fibers have substantial advantages, having no influence on formation and clarity of coherent fringes. Two kinds of optical fiber speckle holographic interferometry systems are often used. The first kind employs an optical bundle
NASA Astrophysics Data System (ADS)
Lee, Young Ki; Ahn, Kyung Hyun; Lee, Seung Jong
2014-12-01
The local shear stress of non-Brownian suspensions was investigated using the lattice Boltzmann method coupled with the smoothed profile method. Previous studies have only focused on the bulk rheology of complex fluids because the local rheology of complex fluids was not accessible due to technical limitations. In this study, the local shear stress of two-dimensional solid particle suspensions in Couette flow was investigated with the method of planes to correlate non-Newtonian fluid behavior with the structural evolution of concentrated particle suspensions. Shear thickening was successfully captured for highly concentrated suspensions at high particle Reynolds number, and both the local rheology and local structure of the suspensions were analyzed. It was also found that the linear correlation between the local particle stress and local particle volume fraction was dramatically reduced during shear thickening. These results clearly show how the change in local structure of suspensions influences the local and bulk rheology of the suspensions.
Lee, Young Ki; Ahn, Kyung Hyun; Lee, Seung Jong
2014-12-01
The local shear stress of non-Brownian suspensions was investigated using the lattice Boltzmann method coupled with the smoothed profile method. Previous studies have only focused on the bulk rheology of complex fluids because the local rheology of complex fluids was not accessible due to technical limitations. In this study, the local shear stress of two-dimensional solid particle suspensions in Couette flow was investigated with the method of planes to correlate non-Newtonian fluid behavior with the structural evolution of concentrated particle suspensions. Shear thickening was successfully captured for highly concentrated suspensions at high particle Reynolds number, and both the local rheology and local structure of the suspensions were analyzed. It was also found that the linear correlation between the local particle stress and local particle volume fraction was dramatically reduced during shear thickening. These results clearly show how the change in local structure of suspensions influences the local and bulk rheology of the suspensions. PMID:25615103
Neural correlates of the ‘good life’: eudaimonic well-being is associated with insular cortex volume
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
Maternal Iodine Status and Thyroid Volume during Pregnancy: Correlation with Neonatal Iodine Intake
P. P. A. Smyth; A. M. T. HETHERTON; D. F. SMITH; M. RADCLIFF; C. O'HERLIHY
1997-01-01
Differences in pregnancy-associated alterations in thyroid vol- ume and urinary iodine (UI) excretion have been attributed to geographical variations in dietary iodine intake. In this study, ultrasound-measured thyroid volume and UI excretion were as- sessed during the 3 trimesters of pregnancy, at delivery, and at 6 weeks postpartum. Urine specimens also were obtained from moth- ers and both breast- and
CORRELATED EVOLUTION OF GENOME SIZE AND CELL VOLUME IN DIATOMS (BACILLARIOPHYCEAE)1
Moline, Mark
. Diatom cell volume is an important component of the global carbon cycle; therefore, understanding of their frustules marks them as major players in the global biogeochemical silica cycle (Treguer et al. 1995, Yool to the cell (Cavalier-Smith 1978). The existence of this relation- ship in diatoms is of particular interest
C. M. Kipps; A. J. Duggins; E. A. Mccusker; A. J. Calder
2007-01-01
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
Analysis of the geometry of a holographic memory setup
NASA Astrophysics Data System (ADS)
Márquez, A.; Fernández, E.; Martínez, F. J.; Gallego, S.; Ortuño, M.; Beléndez, A.; Pascual, I.
2012-06-01
Typically 4-f systems are considered as the basis for holographic memory setups. However, other geometries, such as the convergent correlator, may also be considered. This is a setup widely used in optical processing architectures but not so much explored in holographic data storage systems. It provides some benefits when used in optical processing such as flexibility in the adjustment between Fourier filter dimensions and the Fourier transform of the scene. It also allows a wider freedom in the choice of the optical systems (lenses) used in the setup since it is no longer necessary that their focal lengths match, and the total length of the setup may be shortened. In this paper we make use of Fourier optics techniques to analyze the validity and possible benefits of this setup in its application to holographic memories. We consider the recording and the reconstruction steps. Both analytical expressions and simulated results are given.
Kapp, O. H.; Moens, L.; Vanfleteren, J.; Trotman, C. N.; Suzuki, T.; Vinogradov, S. N.
1995-01-01
Seven-hundred globin sequences, including 146 nonvertebrate sequences, were aligned on the basis of conservation of secondary structure and the avoidance of gap penalties. Of the 182 positions needed to accommodate all the globin sequences, only 84 are common to all, including the absolutely conserved PheCD1 and HisF8. The mean number of amino acid substitutions per position ranges from 8 to 13 for all globins and 5 to 9 for internal positions. Although the total sequence volumes have a variation approximately 2-3%, the variation in volume per position ranges from approximately 13% for the internal to approximately 21% for the surface positions. Plausible correlations exist between amino acid substitution and the variation in volume per position for the 84 common and the internal but not the surface positions. The amino acid substitution matrix derived from the 84 common positions was used to evaluate sequence similarity within the globins and between the globins and phycocyanins C and colicins A, via calculation of pairwise similarity scores. The scores for globin-globin comparisons over the 84 common positions overlap the globin-phycocyanin and globin-colicin scores, with the former being intermediate. For the subset of internal positions, overlap is minimal between the three groups of scores. These results imply a continuum of amino acid sequences able to assume the common three-on-three alpha-helical structure and suggest that the determinants of the latter include sites other than those inaccessible to solvent. PMID:8535255
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 (?nsat) 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 ?nsat, S and shrinkage, respectively). The improved thermal stability of volume holograms recorded in the nanocomposites is also confirmed experimentally.
Tom G. Mackay; James Clerk
2004-01-01
In conventional approaches to the homogenization of random particulate\\u000acomposites, both the distribution and size of the component phase particles are\\u000aoften inadequately taken into account. Commonly, the spatial distributions are\\u000acharacterized by volume fraction alone, while the electromagnetic response of\\u000aeach component particle is represented as a vanishingly small depolarization\\u000avolume. The strong-permittivity-fluctuation theory (SPFT) provides an\\u000aalternative approach
Karl Tordrup; Antonio Negretti; Klaus Molmer
2008-07-22
We propose that a single mesoscopic ensemble of trapped polar molecules can support a "holographic quantum computer" with hundreds of qubits encoded in collective excitations with definite spatial phase variations. Each phase pattern is uniquely addressed by optical Raman processes with classical optical fields, while one- and two-qubit gates are accomplished by selectively transferring the individual qubit states to a stripline microwave cavity field and a Cooper pair box where controllable two-level unitary dynamics is governed by classical microwave fields.
Holographic model of superfluidity
Herzog, C. P.; Kovtun, P. K.; Son, D. T. [Department of Physics, Princeton University, Princeton, New Jersey 08544 (United States); Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia, V8P 5C2 (Canada); Institute for Nuclear Theory, University of Washington, Seattle, Washington 98195-1550 (United States)
2009-03-15
We study a holographic model of a relativistic quantum system with a global U(1) symmetry, at nonzero temperature and density. When the temperature falls below a critical value, we find a second-order superfluid phase transition with mean-field critical exponents. In the symmetry-broken phase, we determine the speed of second sound as a function of temperature. As the velocity of the superfluid component relative to the normal component increases, the superfluid transition goes through a tricritical point and becomes first order.
Biopolymer holographic diffraction gratings
NASA Astrophysics Data System (ADS)
Savi? Ševi?, Svetlana; Panteli?, Dejan
2008-03-01
Surface-relief diffraction gratings are holographically recorded in dextran sensitized with ammonium dichromate (DCD). DCD was exposed with single-frequency 200 mW diode pumped ND-YAG laser, at 532 nm. The diffraction grating profiles were analyzed by atomic force microscopy (AFM). It was found that different surface profiles could be obtained. Gratings with 330 lines/mm spatial frequencies were made. Existence of higher harmonics in Fourier Transform of non-sinusoidal profiles shows that DCD is capable of recording spatial frequencies up to 1320 lines/mm (four times fundamental frequency). The measured maximum relief depth of the DCD grating is 402 nm.
Y. Jack Ng
2010-01-03
Due to quantum fluctuations, probed at small scales, spacetime is very complicated -- something akin in complexity to a turbulent froth which the late John Wheeler dubbed quantum foam, aka spacetime foam. Our recent work suggests that (1) we may be close to being able to detect quantum foam with extragalactic sources once the Very Large Telescope Interferometers (VLTI) are fully operational; (2) dark energy is arguably a cosmological manifestation of quantum foam, the constituents of which obey infinite statistics; (3) in the gravitational context, turbulence is closely related to holographic quantum foam, partly validating Wheeler's picture of a turbulent spacetime.
Introduction to Holographic Superconductors
Gary T. Horowitz
2010-02-17
These lectures give an introduction to the theory of holographic superconductors. These are superconductors that have a dual gravitational description using gauge/gravity duality. After introducing a suitable gravitational theory, we discuss its properties in various regimes: the probe limit, the effects of backreaction, the zero temperature limit, and the addition of magnetic fields. Using the gauge/gravity dictionary, these properties reproduce many of the standard features of superconductors. Some familiarity with gauge/gravity duality is assumed. A list of open problems is included at the end.
Models of holographic superconductivity
Aprile, Francesco [Institute of Cosmos Sciences and Estructura i Constituents de la Materia Facultat de Fisica, Universitat de Barcelona, Avenida Diagonal 647, 08028 Barcelona (Spain); Russo, Jorge G. [Institute of Cosmos Sciences and Estructura i Constituents de la Materia Facultat de Fisica, Universitat de Barcelona, Avenida Diagonal 647, 08028 Barcelona (Spain); Institucio Catalana de Recerca i Estudis Avancats (ICREA), Paseo Lluis Companys, 23, 08010 Barcelona (Spain)
2010-01-15
We construct general models for holographic superconductivity parametrized by three couplings which are functions of a real scalar field and show that under general assumptions they describe superconducting phase transitions. While some features are universal and model independent, important aspects of the quantum critical behavior strongly depend on the choice of couplings, such as the order of the phase transition and critical exponents of second-order phase transitions. In particular, we study a one-parameter model where the phase transition changes from second to first order above some critical value of the parameter and a model with tunable critical exponents.
NASA Astrophysics Data System (ADS)
Geller, Michael; Telem, Ofri
2015-05-01
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 mKK , naturally allowing for mKK 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.
Holographic model of hadronization.
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
Holographic Model of Hadronization
Evans, Nick; Tedder, Andrew [School of Physics and Astronomy, University of Southampton, Southampton, SO17 1BJ (United Kingdom)
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.
Yeo, Seung-Gu [Center for Colorectal Cancer, Research Institute and Hospital, National Cancer Center, Goyang (Korea, Republic of); Department of Radiation Oncology, Soon Chun Hyang University College of Medicine, Cheonan (Korea, Republic of); Kim, Dae Yong, E-mail: radiopiakim@hanmail.ne [Center for Colorectal Cancer, Research Institute and Hospital, National Cancer Center, Goyang (Korea, Republic of); Kim, Tae Hyun [Center for Colorectal Cancer, Research Institute and Hospital, National Cancer Center, Goyang (Korea, Republic of); Jung, Kyung Hae; Hong, Yong Sang [Center for Colorectal Cancer, Research Institute and Hospital, National Cancer Center, Goyang (Korea, Republic of); Department of Medical Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Chang, Hee Jin; Park, Ji Won [Center for Colorectal Cancer, Research Institute and Hospital, National Cancer Center, Goyang (Korea, Republic of); Lim, Seok-Byung [Center for Colorectal Cancer, Research Institute and Hospital, National Cancer Center, Goyang (Korea, Republic of); Department of Colon and Rectal Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Choi, Hyo Seong [Center for Colorectal Cancer, Research Institute and Hospital, National Cancer Center, Goyang (Korea, Republic of); Jeong, Seung-Yong [Center for Colorectal Cancer, Research Institute and Hospital, National Cancer Center, Goyang (Korea, Republic of); Department of Surgery, Seoul National University College of Medicine, Seoul (Korea, Republic of)
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.
The correlation between the Trendelenburg position and the stroke volume variation
Lee, Sang Eun; Lee, Hong Sik; Chae, Young Keun; Lee, Yong Kyung; Kang, Yoo; Je, Ui Jin
2014-01-01
Background The stroke volume variation (SVV), based on lung-heart interaction during mechanical ventilation, is a useful dynamic parameter for fluid responsiveness. However, it is affected by many factors. The aim of this study was to evaluate the effects of SVV on Trendelenburg (T) and reverse Trendelenburg (RT) position and to further elaborate on the patterns of the SVV with position. Methods Forty-two patients undergoing elective surgery were enrolled in this study. Fifteen minutes after standardized induction of anesthesia with propofol, fentanyl, and rocuronium with volume controlled ventilation (tidal volume of 8 ml/kg of ideal body weight, inspiration : expiration ratio of 1 : 2, and respiratory rate of 10-13 breaths/min), the patients underwent posture changes as follows: supine, T position at slopes of operating table of -5°, -10°, and -15°, and RT position at slopes of operating table of 5°, 10°, and 15°. At each point, SVV, cardiac output (CO), peak airway pressure (PAP), mean blood pressure, and heart rate (HR) were recorded. Results The SVV was significant decreased with decreased slopes of operating table in T position, and increased with increased slopes of operating table in RT position (P = 0.000). Schematically, it was increased by 1% when the slope of operating table was increased by 5°. But, the CO and PAP were significant increased with decreased slopes of operating table in T position, and decreased with increased slopes of operating table in RT position (P = 0.045, 0.027). Conclusions SVV is subjected to the posture, and we should take these findings into account on reading SVV for fluid therapy. PMID:25558337
Holographic disk for data storage
NASA Astrophysics Data System (ADS)
Mikaelyan, A. L.; Vanin, A. F.; Gulanyan, E. Kh.; Prokopenko, S. A.
1988-02-01
The feasibility of high-density data storage on a holographic disk is examined on the basis of appropriate schemes for recording and readout of digital optical signals. Equipment necessary and available for this purpose is described, the performance of principal component devices being evaluated for optimization with reference to signal and carrier characteristics as well as to holograph geometry. Theoretical analysis of the problem and the experimental results already reported indicate the scope of applications for the holographic disk and attainable disk quality for data storage.
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.
Introduction to holographic superconductor models
NASA Astrophysics Data System (ADS)
Cai, RongGen; Li, Li; Li, LiFang; Yang, RunQiu
2015-06-01
In the last years it has been shown that some properties of strongly coupled superconductors can be potentially described by classical general relativity living in one higher dimension, which is known as holographic superconductors. This paper gives a quick and introductory overview of some holographic superconductor models with s-wave, p-wave and d-wave orders in the literature from point of view of bottom-up, and summarizes some basic properties of these holographic models in various regimes. The competition and coexistence of these superconductivity orders are also studied in these superconductor models.
Baryonic Matter in Holographic QCD
NASA Astrophysics Data System (ADS)
Nawa, K.; Suganuma, H.; Kojo, T.
We study baryons and baryonic matter in holographic QCD withD4/D8/overline{D8} multi-D brane system. In large-N_c holographic QCD, the baryon appears as a topologically non-trivial chiral soliton, which is called ``brane-induced Skyrmion''. We also analyze the features of the baryonic matter in holographic QCD by investigating the system of single brane-induced Skyrmion on a three-dimensional closed manifold S^3. We propose a new interesting picture of ``pion dominance'' near the critical density.
B. S. von Ungern-Sternberg; A. Regli; M. C. Schneider; F. Kunz; A. Reber
Methods. We prospectively studied 161 patients having either breast surgery (Group A, n=80) or lower abdominal laparotomy (Group B, n=81). Premedication and general anaesthesia were standardized. Spirometry was measured with the patient supine, in a 30? head-up position. We measured vital capacity (VC), forced vital capacity, peak expiratory flow and forced expiratory volume in 1 s at preoperative assessment (baseline),
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.
Correlation-based multivariate analysis of genetic influence on brain volume.
Hardoon, David R; Ettinger, Ulrich; Mourão-Miranda, Janaina; Antonova, Elena; Collier, David; Kumari, Veena; Williams, Steven C R; Brammer, Michael
2009-02-01
Considerable research effort has focused on achieving a better understanding of the genetic correlates of individual differences in volumetric and morphological brain measures. The importance of these efforts is underlined by evidence suggesting that brain changes in a number of neuropsychiatric disorders are at least partly genetic in origin. The currently used methods to study these relationships are mostly based on single-genotype univariate analysis techniques. These methods are limited as multiple genes are likely to interact with each other in their influences on brain structure and function. In this paper we present a feasibility study where we show that by using kernel correlation analysis, with a new genotypes representation, it is possible to analyse the relative associations of several genetic polymorphisms with brain structure. The implementation of the method is demonstrated on genetic and structural magnetic resonance imaging (MRI) data acquired from a group of 16 healthy subjects by showing the multivariate genetic influence on grey and white matter. PMID:19028548
Adventures in Holographic Dimer Models
Kachru, Shamit; /Stanford U., Phys. Dept. /SLAC; Karch, Andreas; /Washington U., Seattle; 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.
Digital holographic imaging of microorganisms
Wolf, Michael Trevor
2006-01-01
Imaging aquatic microorganisms in 3D space is of interest to biologists and ocean scientists seeking to understand the behavior of these organisms in their natural environments. In this research, digital holographic imaging ...
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.
Cerebellar gray matter and lobular volumes correlate with core autism symptoms
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
Holographic dark-energy models
Sergio Del Campo; Júlio. C. Fabris; Ramón Herrera; Winfried Zimdahl
2011-01-01
Different holographic dark-energy models are studied from a unifying point of view. We compare models for which the Hubble scale, the future event horizon or a quantity proportional to the Ricci scale are taken as the infrared cutoff length. We demonstrate that the mere definition of the holographic dark-energy density generally implies an interaction with the dark-matter component. We discuss
Investigation on the holographic principle
Li Jiang
2003-01-01
The holographic principle asserts that any given codimension two space-like surface limits the information content of adjacent regions. We first review various entropy bounds which lead to the formulation of this conjecture, putting great emphasis on the UV-IR connection. We propose to use non-commutative field theory as a toy model to study the holographic mapping mechanism. In particular, we investigate
A holographic charged preon model
T. R. Mongan
2013-04-20
The Standard Model (SM) is a successful approach to particle physics calculations. However, there are indications that the SM is only a good approximation to an underlying non-local reality involving fundamental entities (preons) that are not point particles. Furthermore, our universe seems to be dominated by a vacuum energy/cosmological constant. The holographic principle then indicates only a finite number of bits of information will ever be available to describe the observable universe, and that requires a holographic preon model linking the (0,1) holographic bits to SM particles. All SM particles have charges 0, 1/3, 2/3 or 1 in units of the electron charge, so the bits in a holographic preon model must be identified with fractional electric charge. Such holographic charged preon models require baryon asymmetry and also suggest a mechanism for stationary action. This paper outlines a holographic charged preon model where preons are strands with finite energy density specified by bits of information identifying the charge on each end. In the model, SM particles consist of three strands with spin states corresponding to wrapped states of the strands. SM particles in this wrapped preon model can be approximated by preon bound states in non-local dynamics based on three-preon Bethe-Salpeter equations with instantaneous three-preon interactions. The model can be falsified by data from the Large Hadron Collider because it generates baryon asymmetry without axions, and does not allow more than three generations of SM fermions.
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.
Holographic Tunneling Wave Function
Gabriele, Conti; van der Woerd, Ellen
2015-01-01
The Hartle-Hawking wave function in cosmology can be viewed as a decaying wave function with anti-de Sitter (AdS) boundary conditions. We show that the growing wave function in AdS familiar from Euclidean AdS/CFT is equivalent, semiclassically and up to surface terms, to the tunneling wave function in cosmology. The cosmological measure in the tunneling state is given by the partition function of certain relevant deformations of CFTs on a locally AdS boundary. We compute the partition function of finite constant mass deformations of the O(N) vector model on the round three sphere and show this qualitatively reproduces the behaviour of the tunneling wave function in Einstein gravity coupled to a positive cosmological constant and a massive scalar. We find the amplitudes of inhomogeneities are not damped in the holographic tunneling state.
Dissecting holographic conductivities
Davison, Richard A
2015-01-01
The DC thermoelectric conductivities of holographic systems in which translational symmetry is broken can be efficiently computed in terms of the near-horizon data of the dual black hole. By calculating the frequency dependent conductivities to the first subleading order in the momentum relaxation rate, we give a physical explanation for these conductivities in the simplest such example, in the limit of slow momentum relaxation. Specifically, we decompose each conductivity into the sum of a coherent contribution due to momentum relaxation and an incoherent contribution, due to intrinsic current relaxation. This decomposition is different from those previously proposed, and is consistent with the known hydrodynamic properties in the translationally invariant limit. This is the first step towards constructing a consistent theory of charged hydrodynamics with slow momentum relaxation.
A Striped Holographic Superconductor
Raphael Flauger; Enrico Pajer; Stefanos Papanikolaou
2010-11-15
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 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 the critical temperature on the modulation's wave vector, which characterizes the inhomogeneity. We find that it is qualitatively similar to that expected for a weakly coupled BCS theory, but we point out a quantitative difference. Finally, we use our solutions to compute the conductivity along the direction of the stripes.
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.
Holographic Tunneling Wave Function
Conti Gabriele; Thomas Hertog; Ellen van der Woerd
2015-06-24
The Hartle-Hawking wave function in cosmology can be viewed as a decaying wave function with anti-de Sitter (AdS) boundary conditions. We show that the growing wave function in AdS familiar from Euclidean AdS/CFT is equivalent, semiclassically and up to surface terms, to the tunneling wave function in cosmology. The cosmological measure in the tunneling state is given by the partition function of certain relevant deformations of CFTs on a locally AdS boundary. We compute the partition function of finite constant mass deformations of the O(N) vector model on the round three sphere and show this qualitatively reproduces the behaviour of the tunneling wave function in Einstein gravity coupled to a positive cosmological constant and a massive scalar. We find the amplitudes of inhomogeneities are not damped in the holographic tunneling state.
Estes, John; O'Bannon, Andy; Tsatis, Efstratios; Wrase, Timm
2014-01-01
We study a number of (3+1)- and (2+1)-dimensional defect and boundary conformal field theories holographically dual to supergravity theories. In all cases the defects or boundaries are planar, and the defects are codimension-one. Using holography, we compute the entanglement entropy of a (hemi-)spherical region centered on the defect (boundary). We define defect and boundary entropies from the entanglement entropy by an appropriate background subtraction. For some (3+1)-dimensional theories we find evidence that the defect/boundary entropy changes monotonically under certain renormalization group flows triggered by operators localized at the defect or boundary. This provides evidence that the g-theorem of (1+1)-dimensional field theories generalizes to higher dimensions.
Stability of holographic superconductors
Kanno, Sugumi [Centre for Particle Theory, Department of Mathematical Sciences, Durham University, Science Laboratories, South Road, Durham, DH1 3LE (United Kingdom); Soda, Jiro [Department of Physics, Kyoto University, Kyoto, 606-8501 (Japan)
2010-10-15
We study the dynamical stability of holographic superconductors. We first classify perturbations around black hole background solutions into vector and scalar sectors by means of a 2-dimensional rotational symmetry. We prove the stability of the vector sector by explicitly constructing the positive definite Hamiltonian. To reveal a mechanism for the stabilization of a superconducting phase, we construct a quadratic action for the scalar sector. From the action, we see the stability of black holes near a critical point is determined by the equation of motion for a charged scalar field. We show the effective mass of the charged scalar field in hairy black holes is always above the Breitenlohner-Freedman bound near the critical point due to the backreaction of a gauge field. It implies the stability of the superconducting phase. We also argue that the stability continues away from the critical point.
Perturbatively charged holographic disorder
Daniel K. O'Keeffe; Amanda W. Peet
2015-04-13
Within the framework of holography applied to condensed matter physics, we study a model of perturbatively charged disorder in D=4 dimensions. Starting from initially uncharged AdS_4, a randomly fluctuating boundary chemical potential is introduced by turning on a bulk gauge field parameterized by a disorder strength and a characteristic scale k_0. Accounting for gravitational backreaction, we construct an asymptotically AdS solution perturbatively in the disorder strength. The disorder averaged geometry displays unphysical divergences in the deep interior. We explain how to remove these divergences and arrive at a well behaved solution. The disorder averaged DC conductivity is calculated and is found to contain a correction to the AdS result. The correction appears at second order in the disorder strength and scales inversely with k_0. We discuss the extension to a system with a finite initial charge density. The disorder averaged DC conductivity may be calculated by adopting a technique developed for holographic lattices.
NASA Astrophysics Data System (ADS)
Rangamani, Mukund; Rozali, Moshe; Wong, Anson
2015-04-01
We study the dynamical evolution of strongly coupled field theories, initially in thermal equilibrium, under the influence of an external driving force. We model the field theory holographically using classical gravitational dynamics in an asymptotically AdS spacetime. The system is driven by a source for a (composite) scalar operator. We focus on a scenario where the external source is periodic in time and chart out the response of several observables. We find an interesting phase structure in the response as a function of the amplitude of the source and driving frequency. Specifically the system transitions from a dissipation dominated phase, via a dynamical crossover to a highly resonant amplification phase. The diagnostics of these phases include the response of the operator in question, entropy production, energy fluctuations, and the temporal change of entanglement entropy for small subsystems. We comment on evidence for a potential phase transition in the energy fluctuations of the system.
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.
NASA Astrophysics Data System (ADS)
Williamson, J. J.; Evans, R. M. L.
2014-10-01
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.
Interactive Holographic Stereograms with Accommodation Cues
Smithwick, Quinn Y. J.
Image-based holographic stereogram rendering methods for holographic video have the attractive properties of moderate computational cost and correct handling of occlusions and translucent objects. These methods are also ...
Holograph in noncommutative geometry: Part 1
Jingbo Wang
2010-07-18
In this paper, we consider the holograph principle emergent from noncommutative geometry, based on the spectral action principle. We show that under some appropriate conditions, the gravity theory on a manifold with boundary could be equivalent to a gauge theory $SU(N)$ on the boundary. Then an expression for $N$ with the geometrical quantities of the manifold is given. Based on this result, we find that the volume of the manifold and the boundary have some discrete structure. Applying the result to the black hole, we get that the radium of the Schwarzschild black hole is quantized. We also find an explanation why the extremal RN-black hole has zero temperature but with finite entropy.
Single port access holographic particle image velocimetry
Woodruff, S.D.; Richards, G.A. [USDOE Morgantown Energy Technology Center, WV (United States); Cha, D.J. [National Research Council, Washington, DC (United States)
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.
Holographic geometry and noise in matrix theory
Craig J. Hogan; Mark G. Jackson
2009-01-01
Using matrix theory as a concrete example of a fundamental holographic theory, we show that the emergent macroscopic spacetime displays a new macroscopic quantum structure, holographic geometry, and a new observable phenomenon, holographic noise, with phenomenology similar to that previously derived on the basis of a quasimonochromatic wave theory. Traces of matrix operators on a light sheet with a compact
Developments in holographic-based scanner designs
David M. Rowe
1997-01-01
Holographic-based scanning systems have been used for years in the high resolution prepress markets where monochromatic lasers are generally utilized. However, until recently, due to the dispersive properties of holographic optical elements (HOEs), along with the high cost associated with recording 'master' HOEs, holographic scanners have not been able to penetrate major scanning markets such as the laser printer and
Das, Soma
www.ajhg.org The American Journal of Human Genetics Volume 81 July 2007 165 REPORT Correlation that is a direct measure of Darwinian selection. Estimation of the genetic contribution to this phenotype in human the Departments of Medicine (A.P.), Human Genetics (D.K.N.; M.S.M.; C.O.), Obstetrics and Gynecology (C
The Holographic Models of the scalar sector of QCD
F. Jugeau
2009-12-14
We investigate the AdS/QCD duality for the two-point correlation functions of the lowest dimension scalar meson and scalar glueball operators, in the case of the Soft Wall holographic model of QCD. Masses and decay constants as well as gluon condensates are compared to their QCD estimates. In particular, the role of the boundary conditions for the bulk-to-boundary propagators is emphasized.
Sabry, Mohamed; Halder, Sunil K; Allah, Abdou S Ait; Roshdy, Eman; Rajaratnam, Veera; Al-Hendy, Ayman
2013-01-01
Purpose Currently there is no effective medicinal treatment for uterine fibroids (UFs), a common health disorder that affects women of reproductive age. Identification of modifiable risk factors such as vitamin D (Vit D) deficiency could help develop novel strategies for the prevention and/or treatment of UFs. The purpose of this study was to identify whether low serum Vit D3 levels correlate with increased risk of UFs. Methods A total of 154 premenopausal women were recruited for this cross-sectional study. The control group comprised 50 subjects with a normal, fibroid-free uterine structure, confirmed by transvaginal ultrasonography. The 104 case subjects had at least one fibroid lesion that was 2 cm3 in volume or larger, confirmed by transvaginal ultrasonography. For each case subject, total uterine volume and total volume of all existing fibroids were measured in three perpendicular planes, with volume determined according to the prolate ellipse formula (a × b × c × 0.523), where a is height, b is width, and c is depth. Serum Vit D [25(OH) D3] levels were measured by radioimmunoassay. The independent t-test was used to compare serum Vit D levels across groups. Correlations were assessed by Spearman’s rank correlation test. Results Lower serum 25-(OH) Vit D levels were significantly associated with the occurrence of UFs (P = 0.01). A statistically significant inverse correlation was also observed between serum 25-(OH) Vit D levels and total UF volume (r = ?0.31; P = 0.002) within the case cohort. Subjects with larger fibroid volumes had lower serum Vit D levels and vice versa. Data stratified for ethnicity showed a statistically significant inverse correlation between serum 25-(OH) Vit D levels and total fibroid volume in black subjects (r = ?0.42; P = 0.001). An inverse correlation was also evident in white subjects (r = ?0.86; P = 0.58) but this did not reach statistical significance. Conclusion Lower serum Vit D levels are inversely correlated with UF burden in different ethnic groups. Vit D deficiency is a possible risk factor for the occurrence of UFs. PMID:23467803
Organic DFB lasers: holographic patterning
NASA Astrophysics Data System (ADS)
O'Neill, Feidhlim T.; Lawrence, Justin R.; Kennedy, M.; Foulger, S. H.; Sheridan, John T.
2005-06-01
Integrated optical circuits are an important technology for future high tech products. At present there is great interest in producing polymer based optical circuits. These circuits have a number of potential advantages over current silica/semiconductor based systems. These polymer optical circuits have been used to produce waveguide technology. However in general the production of laser systems for these circuits still depends on older semiconductor technologies. Polymer lasers provide a possible candidate for integrated flexible lasers. Many of the systems demonstrated to date use silica/semiconductor substrates to provide sufficient refractive index variation to provide efficient feedback. A novel alternative to this technology is the holographic distributed feedback (DFB) laser geometry. In this system the lasing material is dispersed in a photopolymer holographic recording material. DFB is then provided by a refractive index structure recorded in the material using holographic techniques. In this paper we discuss a range of holographically recorded feedback geometries and examine the possibility of using this technique to produce organic DFB lasers using non contact holographic patterning.
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
Multiplexed holographic Fabry-Perot étalons.
Lin, F; Chou, H; Strzelecki, E; Shellan, J B
1992-05-10
We discuss a multiplexed holographic Fabry-Perot étalon that includes a multiplexed hologram in a novel holographic Fabry-Perot étalon. Two unique advantages can be achieved by using the multiplexed holographic Fabry-Perot étalon: coherently coupled fabrication of holographic Fabry-Perot mirrors significantly reduces the need to have the nearly flat surfaces typically required in conventional Fabry-Perot etalons, and the angular-wavelength multiplexing capability of a multiplexed hologram can be added to the tunable narrow-band filtering capability of Fabry-Perot étalons. Several types of multiplexed holographic Fabry-Perot étalon are experimentally demonstrated. PMID:20725173
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.
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.
Performance evaluation of a holographic optical neural network system
NASA Astrophysics Data System (ADS)
Lu, Thomas T.; Kostrzewski, Andrew A.; Chou, Hung; Wu, Shudong; Lin, Freddie S.
1993-02-01
One of the most outstanding properties of artificial neural networks is their capability for massive interconnection and parallel processing. Recently, specialized electronic neural network processors and VLSI neural chips have been introduced to the commercial market. The number of parallel channels they can handle is limited because of the limited parallel interconnections number with one-dimensional (1-D) electronic wires. High resolution pattern recognition problems may require a large number of neurons for parallel processing of the image. The holographic optical neural network (HONN) based on high resolution volume holographic materials is capable of providing 3-D massive parallel interconnection of tens of thousand of neurons. A HONN with 3600 neurons, contained in a portable briefcase, has been developed. Rotation-shift-scale invariant pattern recognition operations have been demonstrated with this system. System parameters, such as signal-to-noise ratio, dynamic range, and processing speed, will be discussed.
A supersymmetric holographic dual of a fractional topological insulator
Martin Ammon; Michael Gutperle
2012-04-10
We construct a supersymmetric generalization of the holographic dual of a fractional topological insulator found in \\cite{HoyosBadajoz:2010ac}. This is accomplished by introducing a nontrivial gauge field on the world volume of the probe D7 brane. The BPS equations are derived from the $\\kappa$-symmetry transformation of the probe brane. The BPS equations are shown to reduce to two first oder nonlinear partial differential equations. Solutions of the BPS equations correspond to a probe brane configuration which preserves four of the thirty-two supersymmetries of the $AdS_5\\times S^5$ background. Solutions of the BPS equations which correspond to a holographic fractional topological insulator are obtained numerically.
A supersymmetric holographic dual of a fractional topological insulator
Ammon, Martin
2012-01-01
We construct a supersymmetric generalization of the holographic dual of a fractional topological insulator found in \\cite{HoyosBadajoz:2010ac}. This is accomplished by introducing a nontrivial gauge field on the world volume of the probe D7 brane. The BPS equations are derived from the $\\kappa$-symmetry transformation of the probe brane. The BPS equations are shown to reduce to two first oder nonlinear partial differential equations. Solutions of the BPS equations correspond to a probe brane configuration which preserves four of the thirty-two supersymmetries of the $AdS_5\\times S^5$ background. Solutions of the BPS equations which correspond to a holographic fractional topological insulator are obtained numerically.
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.
Holographic holes in higher dimensions
NASA Astrophysics Data System (ADS)
Myers, Robert C.; Rao, Junjie; Sugishita, Sotaro
2014-06-01
We extend the holographic construction of [1] from AdS3 to higher dimensions. In particular, we show that the Bekenstein-Hawking entropy of codimension-two surfaces in the bulk with planar symmetry can be evaluated in terms of the `differential entropy' in the boundary theory. The differential entropy is a certain quantity constructed from the entanglement entropies associated with a family of regions covering a Cauchy surface in the boundary geometry. We demonstrate that a similar construction based on causal holographic information fails in higher dimensions, as it typically yields divergent results. We also show that our construction extends to holographic backgrounds other than AdS spacetime and can accommodate Lovelock theories of higher curvature gravity.
Constraining holographic inflation with WMAP
Easther, Richard; Flauger, Raphael [Department of Physics, Yale University, 217 Prospect Street, New Haven, CT 06520 (United States); McFadden, Paul [Institute for Theoretical Physics, Science Park 904, 1090 GL Amsterdam (Netherlands); Skenderis, Kostas, E-mail: Richard.Easther@yale.edu, E-mail: Raphael.Flauger@yale.edu, E-mail: P.L.McFadden@uva.nl, E-mail: K.Skenderis@uva.nl [Institute for Theoretical Physics, Gravitation and Astro-Particle Physics Amsterdam, Korteweg-de Vries Institute for Mathematics, Science Park 904, 1090 GL Amsterdam (Netherlands)
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 ?CDM 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 ?CDM and find that their difference is not significant, although ?CDM provides a somewhat better fit to the data. However, it appears that Planck will permit a definitive test of this holographic scenario.
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.
Application of holographic lens in head-up display
Huangming Chen; Bo Lu
1987-01-01
Based on the holographic theory, the optical properties and characteristics of aberrations for reflective holographic lens have been described in detail in this paper. The aberration distribution of holographic lens is confirmed by experiments. According to the aberration characteristics of reflective holographic lens, calculation and analysis on asymmetrical spheric system have been performed to compensate aberrations of holographic lens. The
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.
Holographic Multi-Band Superconductor
Ching-Yu Huang; Feng-Li Lin; Debaprasad Maity
2011-09-05
We propose a gravity dual for the holographic superconductor with multi-band carriers. Moreover, the currents of these carriers are unified under a global flavored SO(3) symmetry, which is dual to the bulk SO(3) gauge symmetry. We study the phase diagram of our model, and find it qualitatively agrees with the one for the realistic 2-band superconductor, such as $MgB_2$. We also identify the bulk field dual to the electromagnetic $U(1)_{EM}$ current, which should be invariant under the global flavored SO(3) rotation. We then evaluate the corresponding holographic conductivity and find the expected mean field like behaviors.
Holographic investigations of skin vibrations.
Pawluczyk, R; Kraska, Z; Pawlowski, Z
1982-03-01
The paper describes preliminary results of the use of double-pulse holographic interferometry for vibration investigations of the skin surface of a singer's face (epiphysis), neck, larynx, and sternum. Holographic interferograms obtained in the experiment illustrate a dependence of the distribution of vibrations on the type of sound and on the fundamental frequency for the same person. The vibration interferograms of various persons are different even at the same sound and frequency. The method may become useful for diagnosis of voice timbre as well as in pathological cases. PMID:20372536
Gauge Invariance and Holographic Renormalization
Keun-Young Kim; Kyung Kiu Kim; Yunseok Seo; Sang-Jin Sin
2015-02-07
We study the gauge invariance of physical observables in holographic theories under the local diffeomorphism. We find that gauge invariance is intimately related to the holographic renormalisation: the local counter terms defined in the boundary cancel most of gauge dependences of the on-shell action as well as the divergences. However, there still remain gauge dependent pieces in the on-shell action under some residual gauge transformation, while the equations of motion are invariant. We prove the invariance of the Green's functions under this residual gauge symmetry in the context of constructing numerical solutions by which all related AC transports are computed simultaneously.
Gauge Invariance and Holographic Renormalization
Kim, Keun-Young; Seo, Yunseok; Sin, Sang-Jin
2015-01-01
We study the gauge invariance of physical observables in holographic theories under the local diffeomorphism. We find that gauge invariance is intimately related to the holographic renormalisation: the local counter terms defined in the boundary cancel most of gauge dependences of the on-shell action as well as the divergences. However, there still remain gauge dependent pieces in the on-shell action under some residual gauge transformation, while the equations of motion are invariant. We prove the invariance of the Green's functions under this residual gauge symmetry in the context of constructing numerical solutions by which all related AC transports are computed simultaneously.
Universal properties of cold holographic matter
Jokela, Niko
2015-01-01
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 $AdS_4$ backgrounds and study the anyonic correlators.
Universal properties of cold holographic matter
Niko Jokela; Alfonso V. Ramallo
2015-04-07
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 $AdS_4$ cases and study the anyonic correlators.
Experimental investigation of a page-oriented Lippmann holographic data storage system
Boyer, Edmond
is not recorded: typically, the 3D shape of an object cannot be reproduced. This feature is not a true impediment Polytechnique, RD 128, 91127 Palaiseau cedex, France ABSTRACT Lippmann photography is a more than one century holography. Keywords: Optical data storage, holographic and volume memories, Lippmann photography 1
Kurban, Mark R
2009-03-14
Diffusion of perdeuterated tempone (PDT) in various nonpolar hydrocarbon solvents on both the large and microscopic scales is examined through electron paramagnetic resonance spectroscopy. Spectral line broadening and hyperfine spacing are measured in order to extract both the Heisenberg spin-exchange rate as well as the average recollision times between spin-probe pairs. Probe recollision is responsible for a linear component to the dependence of the line shift on spectral broadening which has been identified in recent years. The present study extends the work of a previous paper by Kurban et al. [J. Chem. Phys. 129, 064501 (2008)], in which it was reported that recollision rates for PDT formed a common curve across n-alkanes when plotted with respect to free volume and to isothermal compressibility. It is now found that such common curves occur within distinct chemical families, in particular, the alkane and aromatic groups. Within each chemical family, the spin probe recollision rate correlates with free volume and compressibility independently of the geometry of the particular solvent. All solvents show significantly enhanced recollisional diffusion over the Stokes-Einstein (SE) prediction at high temperatures. The spin-exchange rate forms a common curve with respect to T/eta for all alkanes except cyclohexane and another common curve in all three aromatic compounds. It is reasoned that although all spin-exchange rates are near to the SE prediction, the semblance of hydrodynamic behavior is superficial and arises incidentally from mathematical cancellation of terms in a generalized diffusion coefficient. As a collision pair coexists for a time within a solvation shell, the recollision time places a lower limit on the lifetime of the solvent cage. Although molecular dynamics simulations conducted thus far have yielded cage lifetimes lower than the measured recollision times, this is attributable to the fact that such simulations have mostly examined cage configurations too small to harbor a spin-exchange encounter, and is also likely due to restrictive mathematical definitions of cage lifetimes that are employed in such simulations. PMID:19292536
Efficient generation of holographic news ticker in holographic 3DTV
NASA Astrophysics Data System (ADS)
Kim, Seung-Cheol; Kim, Eun-Soo
2009-08-01
News ticker is used to show breaking news or news headlines in conventional 2-D broadcasting system. For the case of the breaking news, the fast creation is need, because the information should be sent quickly. In addition, if holographic 3- D broadcasting system is started in the future, news ticker will remain. On the other hands, some approaches for generation of CGH patterns have been suggested like the ray-tracing method and look-up table (LUT) method. However, these methods have some drawbacks that needs much time or needs huge memory size for look-up table. Recently, a novel LUT (N-LUT) method for fast generation of CGH patterns of 3-D objects with a dramatically reduced LUT without the loss of computational speed was proposed. Therefore, we proposed the method to efficiently generate the holographic news ticker in holographic 3DTV or 3-D movies using N-LUT method. The proposed method is largely consisted of five steps: construction of the LUT for each character, extraction of characters in news ticker, generation and shift of the CGH pattern for news ticker using the LUT for each character, composition of hologram pattern for 3-D video and hologram pattern for news ticker and reconstruct the holographic 3D video with news ticker. To confirm the proposed method, moving car in front of the castle is used as a 3D video and the words 'HOLOGRAM CAPTION GENERATOR' is used as a news ticker. From this simulation results confirmed the feasibility of the proposed method in fast generation of CGH patterns for holographic captions.
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.
Holographic gunsights for small arms
Anthony M. Tai; Eric J. Sieczka; Richard Radler; Juris Upatnieks
1996-01-01
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,
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.
Photoemission "experiments" on holographic superconductors
Faulkner, Thomas; McGreevy, John; Roberts, Matthew M; Vegh, David
2009-01-01
We study the effects of a superconducting condensate on holographic Fermi surfaces. With a suitable coupling between the fermion and the condensate, there are stable quasiparticles with a gap. We find some similarities with the phenomenology of the cuprates: in systems whose normal state is a non-Fermi liquid with no stable quasiparticles, a stable quasiparticle peak appears in the condensed phase.
Photoemission "experiments" on holographic superconductors
Thomas Faulkner; Gary T. Horowitz; John McGreevy; Matthew M. Roberts; David Vegh
2009-12-15
We study the effects of a superconducting condensate on holographic Fermi surfaces. With a suitable coupling between the fermion and the condensate, there are stable quasiparticles with a gap. We find some similarities with the phenomenology of the cuprates: in systems whose normal state is a non-Fermi liquid with no stable quasiparticles, a stable quasiparticle peak appears in the condensed phase.
Holographic random access memory (HRAM)
ERNEST CHUANG; Wenhai Liu; JEAN-JACQUES P. DROLET; DEMETRI PSALTIS
1999-01-01
We examine the present state of holographic random access memory (HRAM) systems and address the primary challenges that face this technology, specifically size, speed, and cost. We show that a fast HRAM system can be implemented with a compact architecture by incorporating conjugate readout, a smart-pixel array, and a linear array of laser diodes. Preliminary experimental results support the feasibility
Stealths on Anisotropic Holographic Backgrounds
Eloy Ayón-Beato; Mokhtar Hassaïne; María Montserrat Juárez-Aubry
2015-06-11
In this paper, we are interested in exploring the existence of stealth configurations on anisotropic backgrounds playing a prominent role in the non-relativistic version of the gauge/gravity correspondence. By stealth configuration, we mean a nontrivial scalar field nonminimally coupled to gravity whose energy-momentum tensor evaluated on the anisotropic background vanishes identically. In the case of a Lifshitz spacetime with a nontrivial dynamical exponent z, we spotlight the role played by the anisotropy to establish the holographic character of the stealth configurations, i.e. the scalar field is shown to only depend on the radial holographic direction. This configuration which turns out to be massless and without integration constants is possible for a unique value of the nonminimal coupling parameter. Then, using a simple conformal argument, we map this configuration into a stealth solution defined on the so-called hyperscaling violation metric which is conformally related to the Lifshitz spacetime. This holographic configuration obtained through a conformal mapping constitutes only a particular class within the stealth solutions defined on the hyperscaling violation as it is shown by deriving the most general stealth configurations. The case of the Schrodinger background is also exhaustively analyzed and we establish that the presence of the null direction makes their stealth configurations not necessarily holographic in general and characterized by a self-interacting behavior. Finally, for completeness we also study the stealth configurations on the Schrodinger inspired hyperscaling violation spacetimes.
A Holographic Fractional Topological Insulator
Carlos Hoyos-Badajoz; Kristan Jensen; Andreas Karch
2010-07-19
We give a holographic realization of the recently proposed low energy effective action describing a fractional topological insulator. In particular we verify that the surface of this hypothetical material supports a fractional quantum Hall current corresponding to half that of a Laughlin state.
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.
Palanca, Marco; Tozzi, Gianluca; Cristofolini, Luca; Viceconti, Marco; Dall'Ara, Enrico
2015-07-01
Different digital volume correlation (DVC) approaches are currently available or under development for bone tissue micromechanics. The aim of this study was to compare accuracy and precision errors of three DVC approaches for a particular three-dimensional (3D) zero-strain condition. Trabecular and cortical bone specimens were repeatedly scanned with a micro-computed tomography (CT). The errors affecting computed displacements and strains were extracted for a known virtual translation, as well as for repeated scans. Three DVC strategies were tested: two local approaches, based on fast-Fourier-transform (DaVis-FFT) or direct-correlation (DaVis-DC), and a global approach based on elastic registration and a finite element (FE) solver (ShIRT-FE). Different computation subvolume sizes were tested. Much larger errors were found for the repeated scans than for the virtual translation test. For each algorithm, errors decreased asymptotically for larger subvolume sizes in the range explored. Considering this particular set of images, ShIRT-FE showed an overall better accuracy and precision (a few hundreds microstrain for a subvolume of 50 voxels). When the largest subvolume (50-52 voxels) was applied to cortical bone, the accuracy error obtained for repeated scans with ShIRT-FE was approximately half of that for the best local approach (DaVis-DC). The difference was lower (250 microstrain) in the case of trabecular bone. In terms of precision, the errors shown by DaVis-DC were closer to the ones computed by ShIRT-FE (differences of 131 microstrain and 157 microstrain for cortical and trabecular bone, respectively). The multipass computation available for DaVis software improved the accuracy and precision only for the DaVis-FFT in the virtual translation, particularly for trabecular bone. The better accuracy and precision of ShIRT-FE, followed by DaVis-DC, were obtained with a higher computational cost when compared to DaVis-FFT. The results underline the importance of performing a quantitative comparison of DVC methods on the same set of samples by using also repeated scans, other than virtual translation tests only. ShIRT-FE provides the most accurate and precise results for this set of images. However, both DaVis approaches show reasonable results for large nodal spacing, particularly for trabecular bone. Finally, this study highlights the importance of using sufficiently large subvolumes, in order to achieve better accuracy and precision. PMID:25807338
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.
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-law detector for the purpose of holographic recording of interference fringes. A typical state-of-the-art CCD has a pixel-pitch limited resolution of about 100 lines/mm. In contrast, the holographic photopolymer to be used in the proposed JTOC offers a resolution > 2,000 lines/mm. In addition to being disadvantageous in itself, the low resolution of the CCD causes overlap of a DC term and the desired correlation term in the output image. This overlap severely limits the correlation signal-to-noise ratio. The two-stage nature of the process limits the achievable throughput rate. A further limit is imposed by the low frame rate (typical video rates) of low- and medium-cost commercial CCDs.
Holographic storage — the quest for the ideal material continues
NASA Astrophysics Data System (ADS)
Sincerbox, Glenn T.
1995-01-01
Throughout the 30-year history of holographic storage, an enormous number of material systems have been studied for use as the recording medium. In spite of the years and effort expended, the ideal material has not been identified and interest in holographic storage has waned. Recently, however, advances in both organic and inorganic photorefractive materials has rekindled interest in volume holography, not only for information storage but also as a technology that may be important for optical interconnects, neural networks and optical computing. Interest is further enhanced by continuing development in some of the enabling technologies, such as CCD arrays and spatial light modulators, necessary to make a viable storage product. After a brief introduction to holographic storage, this paper will concentrate on defining the systems requirements that drive material selection and review recent advances in photorefractive materials and techniques that address key issues. Included will be a discussion of multiplexing methods as well as various means to inhibit, or at least manage, destructive writing and reading. The paper will conclude with a discussion of the remaining critical issues as a focus for continued research and development.
Wideband millimeter-wave holographic weapons surveillance systems
NASA Astrophysics Data System (ADS)
McMakin, Douglas L.; Sheen, David M.; Collins, H. D.; Hall, Thomas E.; Severtsen, Ronald H.
1995-09-01
A new wideband millimeter wave holographic imaging technqiue is under developement for use in concealed weapons detection system. This new wideband technique provides far superior images than single frequency holographic techniques on thick objects such as the human body. The wideband technique obtains fully focused images over a designated volume and provides excellent lateral and depth resolution. Using this method, a 3D volumetric hologram is gathered with a millimeter wave linear array, a mechanical scanner, and a sweep frequency tranceiver. The 3D volumetric hologram is then processed by high-speed computational processors to reconstruct the fully focused image. Two prototype wide band millimeter wave holographic arrays have been developed at the Pacific Northwest Laboratory. The two arrays consist of sequentially switched 2 by 37 Ku band (12.5-18 GHz) and 2 by 64 Ka band (26.5-40 GHz) systems which are coupled to high-speed sweep frequency heterodyne transceivers. The arrays are used to obtain volumetric imaging data at high speeds by electronically sequencing and frequency sweeping the array antennas along 1D while performing a mechanical scan along the other dimension. The current prototype system scans an aperture the size of a large human body in about one second. Extensive laboratory testing has been performed with people carrying various concealed weapons and innocuous items with both imaging arrays during the first quarter of 1995.
Coaxial holographic encoding based on pure phase modulation.
Jia, Wei; Chen, Zhongyu; Wen, Fung Jacky; Zhou, Changhe; Chow, Yuk Tak; Chung, Po Sheun
2011-12-01
We describe a simple technique for coaxial holographic image recording and reconstruction, employing a spatial light modulator (SLM) modified in pure phase mode. In the image encoding system, both the reference beam in the outside part and the signal beam in the inside part are displayed by an SLM based on the twisted nematic LCD. For a binary image, the part with amplitude of "1" is modulated with random phase, while the part with amplitude of "0" is modulated with constant phase. After blocking the dc component of the spatial frequencies, a Fourier transform (FT) hologram is recorded with a uniform intensity distribution. The amplitude image is reconstructed by illuminating the reference beam onto the hologram, which is much simpler than existing phase modulated FT holography techniques. The technique of coaxial holographic image encoding and recovering with pure phase modulation is demonstrated theoretically and experimentally in this paper. As the holograms are recorded without the high-intensity dc component, the storage density with volume medium may be increased with the increase of dynamic range. Such a simple modulation method will have potential applications in areas such as holographic encryption and high-density disk storage systems. PMID:22192995
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.
Makizako, Hyuma; Shimada, Hiroyuki; Doi, Takehiko; Park, Hyuntae; Yoshida, Daisuke; Suzuki, Takao
2013-01-01
Background/Aims High fitness levels play an important role in maintaining memory function and delaying the progression of structural brain changes in older people at risk of developing dementia. However, it is unclear which specific regions of the brain volume are associated with exercise capacity. We investigated whether exercise capacity, determined by a 6-min walking distance (6MWD), is associated with measures of logical and visual memory and where gray matter regions correlate with exercise capacity in older adults with mild cognitive impairment (MCI). Methods Ninety-one community-dwelling older adults with MCI completed a 6-min walking test, structural magnetic resonance imaging scanning, and memory tests. The Wechsler Memory Scale-Revised Logical Memory and Rey-Osterrieth Complex Figure Tests were used to assess logical and visual memory, respectively. Results The logical and visual memory tests were positively correlated with the 6MWD (p < 0.01). Poor performance in the 6MWD was correlated with a reduced cerebral gray matter volume in the left middle temporal gyrus, middle occipital gyrus, and hippocampus in older adults with MCI. Conclusions These results suggest that a better 6MWD performance may be related to better memory function and the maintenance of gray matter volume in older adults with MCI. PMID:24052797
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).
Holographic geometry and noise in matrix theory
Craig J. Hogan; Mark G. Jackson
2009-01-01
Using Matrix Theory as a concrete example of a fundamental holographic\\u000atheory, we show that the emergent macroscopic spacetime displays a new\\u000amacroscopic quantum structure, holographic geometry, and a new observable\\u000aphenomenon, holographic noise, with phenomenology similar to that previously\\u000aderived on the basis of a quasi-monochromatic wave theory. Traces of matrix\\u000aoperators on a light sheet with a compact
Partial fringe analysis applied to holographic interferometry
Rathbun, Paul Alan
1990-01-01
Mathematics of Recording Interference CHAPTER III PREVIOUS 1VORK 10 Standard Holography and Fringe Analysis . . Heterodyne Holographic Interferometry Methods Digital Image Processing Methods . . 10 12 14 CHAPTER IV EXPERIMENTAL SETUP 15 Holographic... time or double. ? exposure HI 3 Standard holographic setup which can be used for double ? exposure holog- ra. phy . 11 4 Example of fringe ordering technique 5 Experisnental setup for heterodyne holography 12 13 6 Experimental setup for thesis 16...
Holographic imaging of 3D objects on dichromated polymer systems
NASA Astrophysics Data System (ADS)
Lemelin, Guylain; Jourdain, Anne; Manivannan, Gurusamy; Lessard, Roger A.
1996-01-01
Conventional volume transmission holograms of a 3D scene were recorded on dichromated poly(acrylic acid) (DCPAA) films under 488 nm light. The holographic characterization and quality of reconstruction have been studied by varying the influencing parameters such as concentration of dichromate and electron donor, and the molecular weight of the polymer matrix. Ammonium and potassium dichromate have been employed to sensitize the poly(acrylic) matrix. the recorded hologram can be efficiently reconstructed either with red light or with low energy in the blue region without any post thermal or chemical processing.
Microbial population dynamics by digital in-line holographic microscopy
Frentz, Zak; Kuehn, Seppe; Hekstra, Doeke; Leibler, Stanislas
2010-01-01
Measurements of population dynamics are ubiquitous in experiments with microorganisms. Studies with microbes elucidating adaptation, selection, and competition rely on measurements of changing populations in time. Despite this importance, quantitative methods for measuring population dynamics microscopically, with high time resolution, across many replicates remain limited. Here we present a new noninvasive method to precisely measure microbial spatiotemporal population dynamics based on digital in-line holographic (DIH) microscopy. Our inexpensive, replicate DIH microscopes imaged hundreds of swimming algae in three dimensions within a volume of several microliters on a time scale of minutes over periods of weeks. PMID:20815617
NASA Astrophysics Data System (ADS)
Li, Xiao-Dong; Park, Changbom; Sabiu, Cristiano G.; Kim, Juhan
2015-06-01
We propose a method using the redshift dependence of the Alcock-Paczynski (AP) test and volume effect to measure the cosmic expansion history. The galaxy two-point correlation function as a function of angle, ?(?), is measured at different redshifts. Assuming an incorrect cosmological model to convert galaxy redshifts to distances, the shape of ?(?) appears anisotropic due to the AP effect, and the amplitude is shifted by the change in comoving volume. Due to the redshift dependence of the AP and volume effect, both the shape and amplitude of ?(?) exhibit redshift dependence. Similar to Li et al. (2014), we find that the redshift-space distortions (RSD) caused by galaxy peculiar velocities, although significantly distorting ?(?), exhibit much less redshift evolution compared to the AP and volume effects. By focusing on the redshift dependence of ?(?), we can correctly recover the cosmological parameters despite the contamination of RSD. The method is tested by using the Horizon Run 3 N-body simulation, from which we made a series of 1/8-sky mock surveys having eight million physically self-bound haloes and sampled to have roughly a uniform number density in z = 0-1.5. We find the AP effect results in tight, unbiased constraints on the density parameter and dark energy equation of state, with 68.3% CL intervals ??m ˜ 0.03 and ?w ˜ 0.1, and the volume effect leads to much tighter constraints of ??m ˜ 0.007 and ?w ˜ 0.035.
Holographic Bound From Second Law of Thermodynamics
Jacob D. Bekenstein
2000-04-14
A necessary condition for the validity of the holographic principle is the holographic bound: the entropy of a system is bounded from above by a quarter of the area of a circumscribing surface measured in Planck areas. This bound cannot be derived at present from consensus fundamental theory. We show with suitable {\\it gedanken} experiments that the holographic bound follows from the generalized second law of thermodynamics for both generic weakly gravitating isolated systems and for isolated, quiescent and nonrotating strongly gravitating configurations well above Planck mass. These results justify Susskind's early claim that the holographic bound can be gotten from the second law.
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.
Direct laser writing defects in holographic lithography-created photonic lattices.
Sun, Hong-Bo; Nakamura, Atsushi; Kaneko, Koshiro; Shoji, Satoru; Kawata, Satoshi
2005-04-15
As a well-established laser fabrication approach, holographic lithography, or multibeam interference patterning, is known for its capability to create long-range ordered large-volume photonic crystals (PhCs) rapidly. Its broad use is, however, hampered by difficulty in inducing artificially designed defects for device functions. We use pinpoint femtosecond laser ablation to remove and two-photon photopolymerization to add desired defective features to obtain photonic acceptors and photonic donors, respectively, in an otherwise complete PhC matrix produced by holographic lithography. The combined use of the two direct laser writing technologies would immediately make holographic lithography a promising industrial tool for PhC manufacture. PMID:15865386
Holographic renormalization in dense medium
Chanyong Park
2014-08-21
We investigate the holographic renormalization of a charged black brane with or without a dilaton field, whose dual field theory describes a dense medium at finite temperature. In a dense medium, two different thermodynamic descriptions are possible due to an additional conserved charge. These two different thermodynamic ensembles are classified by the asymptotic boundary condition of the bulk gauge field. We show that in the holographic renormalization regularity of all bulk fields can reproduce consistent thermodynamic quantities and that the Bekenstein-Hawking entropy is nothing but the renormalized thermal entropy of the dual field theory. Furthermore, we find that the Reissner-Nordstrom AdS black brane is dual to a theory with conformal matter as expected, whereas a charged black brane with a nontrivial dilaton profile is mapped to a theory with non-conformal matter although its leading asymptotic geometry still remains as AdS space.
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.
Entropy balance in holographic superconductors
Sean A. Hartnoll; Razieh Pourhasan
2012-05-07
In systems undergoing second order phase transitions, the temperature integral of the specific heat over temperature from zero to the critical temperature is the same in both the normal and ordered phases. This entropy balance relates the critical temperature to the distribution of degrees of freedom in the normal and ordered states. Quantum criticality and fractionalization can imply an increased number of low energy degrees of freedom in both the normal and ordered states. We explore the role of entropy balance in holographic models of superconductivity, focussing on the interplay between quantum criticality and superconductivity. We consider models with and without a ground state entropy density in the normal phase; the latter models are a new class of holographic superconductors. We explain how a normal phase entropy density manifests itself in the stable superconducting phase.
Entropy balance in holographic superconductors
Hartnoll, Sean A
2012-01-01
In systems undergoing second order phase transitions, the temperature integral of the specific heat over temperature from zero to the critical temperature is the same in both the normal and ordered phases. This entropy balance relates the critical temperature to the distribution of degrees of freedom in the normal and ordered states. Quantum criticality and fractionalization can imply an increased number of low energy degrees of freedom in both the normal and ordered states. We explore the role of entropy balance in holographic models of superconductivity, focussing on the interplay between quantum criticality and superconductivity. We consider models with and without a ground state entropy density in the normal phase; the latter models are a new class of holographic superconductors. We explain how a normal phase entropy density manifests itself in the stable superconducting phase.
Sound modes in holographic superfluids
Herzog, Christopher P.; Yarom, Amos [Department of Physics, Princeton University, Princeton, New Jersey 08544 (United States)
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.
Photoemission “experiments” on holographic superconductors
Thomas Faulkner; Gary T. Horowitz; John McGreevy; Matthew M. Roberts; David Vegh
2010-01-01
We study the effects of a superconducting condensate on holographic Fermi surfaces. With a suitable coupling between the fermion\\u000a and the condensate, there are stable quasiparticles with a gap. We find some similarities with the phenomenology of the cuprates:\\u000a in systems whose normal state is a non-Fermi liquid with no stable quasiparticles, a stable quasiparticle peak appears in\\u000a the condensed
EUV holographic aerial image recording
Sang H. Lee; Patrick Naulleau; Kenneth A. Goldberg; Chang H. Cho; Jeffrey Bokor
2000-01-01
One-hundred-nm-resolution holographic aerial image monitoring based on lensless Fourier-transform holography at EUV wavelengths using a synchrotron-based source is described. This method can be used to monitor the coherent imaging performance of EUV lithographic optical systems. The system has been implemented in the EUV phase-shifting point diffraction interferometer (PS\\/PDI) at Lawrence Berkeley National Lab. Here we introduce the idea of the
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.
Gauss-Bonnet Holographic Superconductors
NASA Astrophysics Data System (ADS)
Miskovic, Olivera; Aranguiz, Ligeia
2015-01-01
We study a class of holographic superconductors dual to Einstein-Gauss-Bonnet AdS gravity coupled to nonlinear matter fields. We find an exact formula for the free energy of this system in any dimension and an approximate formula in terms of the thermodynamic quantities. We provide a simple method to select the couplings that admit charged black hole solutions in the bulk and have phase transitions on the boundary.
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.
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.
Wielen, Gerard J. van der [Department of Radiation Oncology, Erasmus MC-Daniel den Hoed Cancer Center, Rotterdam (Netherlands)], E-mail: g.vanderwielen@erasmusmc.nl; Hoogeman, Mischa S. [Department of Radiation Oncology, Erasmus MC-Daniel den Hoed Cancer Center, Rotterdam (Netherlands); Dohle, Gert R. [Department of Urology, Erasmus MC, Rotterdam (Netherlands); Putten, Wim L.J. van [Department of Biostatistics, Erasmus MC-Daniel den Hoed Cancer Center, Rotterdam (Netherlands); Incrocci, Luca [Department of Radiation Oncology, Erasmus MC-Daniel den Hoed Cancer Center, Rotterdam (Netherlands)
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.
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.
Holographic pomeron: Saturation and DIS
NASA Astrophysics Data System (ADS)
Stoffers, Alexander; Zahed, Ismail
2013-04-01
We briefly review the approach to dipole-dipole scattering in holographic QCD developed in G. Basar , Phys. Rev. D 85, 105005 (2012), based on a stringy Schwinger mechanism. The pomeron emerges through the exchange of closed strings between the dipoles and yields Regge behavior for the elastic amplitude. We calculate curvature corrections to this amplitude in both a conformal and confining background, identifying the holographic direction with the virtuality of the dipoles. The wee-dipole density is related to the string tachyon diffusion in both virtuality and the transverse directions. We give an explicit derivation of the dipole saturation momentum both in the conformal and confining background. Our holographic result for the dipole-dipole cross section and the wee-dipole density in the conformal limit are shown to be identical in form to the BFKL pomeron result when the noncritical string transverse dimension is D?=3. The total dipole-dipole cross section is compared to DIS data from HERA.
Polli, Roberson S.; Malheiros, Jackeline M.; dos Santos, Renan; Hamani, Clement; Longo, Beatriz M.; Tannús, Alberto; Mello, Luiz E.; Covolan, Luciene
2014-01-01
Kainic acid (KA) or pilocarpine (PILO) have been used in rats to model human temporal lobe epilepsy (TLE) but the distribution and severity of structural lesions between these two models may differ. Magnetic resonance imaging (MRI) studies have used quantitative measurements of hippocampal T2 (T2HP) relaxation time and volume, but simultaneous comparative results have not been reported yet. The aim of this study was to compare the MRI T2HP and volume with histological data and frequency of seizures in both models. KA- and PILO-treated rats were imaged with a 2?T MRI scanner. T2HP and volume values were correlated with the number of cells, mossy fiber sprouting, and spontaneous recurrent seizures (SRS) frequency over the 9?months following status epilepticus (SE). Compared to controls, KA-treated rats had unaltered T2HP, pronounced reduction in hippocampal volume and concomitant cell reduction in granule cell layer, CA1 and CA3 at 3?months post SE. In contrast, hippocampal volume was unchanged in PILO-treated animals despite detectable increased T2HP and cell loss in granule cell layer, CA1 and CA3. In the following 6?months, MRI hippocampal volume remained stable with increase of T2HP signal in the KA-treated group. The number of CA1 and CA3 cells was smaller than age-matched CTL group. In contrast, PILO group had MRI volumetric reduction accompanied by reduction in the number of CA1 and CA3 cells. In this group, T2HP signal was unaltered at 6 or 9?months after status. Reductions in the number of cells were not progressive in both models. Notably, the SRS frequency was higher in PILO than in the KA model. The volumetry data correlated well with tissue damage in the epileptic brain, suggesting that MRI may be useful for tracking longitudinal hippocampal changes, allowing the assessment of individual variability and disease progression. Our results indicate that the temporal changes in hippocampal morphology are distinct for both models of TLE and that these are not significantly correlated to the frequency of SRS. PMID:25071699
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.
Sugimoto, Katsutoshi; Oshiro, Hisashi; Ogawa, Saori; Honjo, Mitsuyoshi; Hara, Takeshi; Moriyasu, Fuminori
2014-01-01
AIM: To evaluate the usefulness of three-dimensional (3D) shear-wave elastography (SWE) in assessing the liver ablation volume after radiofrequency (RF) ablation. METHODS: RF ablation was performed in vivo in 10 rat livers using a 15-gauge expandable RF needle. 3D SWE as well as B-mode ultrasound (US) were performed 15 min after ablation. The acquired 3D volume data were rendered as multislice images (interslice distance: 1.10 mm), and the estimated ablation volumes were calculated. The 3D SWE findings were compared against digitized photographs of gross pathological and histopathological specimens of the livers obtained in the same sectional planes as the 3D SWE multislice images. The ablation volumes were also estimated by gross pathological examination of the livers, and the results were then compared with those obtained by 3D SWE. RESULTS: In B-mode US images, the ablation zone appeared as a hypoechoic area with a peripheral hyperechoic rim; however, the findings were too indistinct to be useful for estimating the ablation area. 3D SWE depicted the ablation area and volume more clearly. In the images showing the largest ablation area, the mean kPa values of the peripheral rim, central zone, and non-ablated zone were 13.1 ± 1.5 kPa, 59.1 ± 21.9 kPa, and 4.3 ± 0.8 kPa, respectively. The ablation volumes depicted by 3D SWE correlated well with those estimated from gross pathological examination (r2 = 0.9305, P = 0.00001). The congestion and diapedesis of red blood cells observed in histopathological examination were greater in the peripheral rim of the ablation zone than in the central zone. CONCLUSION: 3D SWE outperforms B-mode US in delineating ablated areas in the liver and is therefore more reliable for spatially delineating thermal lesions created by RF ablation. PMID:25206291
Investigation on Nusselt number over heated spinning sphere by real time holographic interferometry
NASA Astrophysics Data System (ADS)
Tieng, S. M.; Yan, A. C.
1992-07-01
The average Nusselt number (ANN) of a heated sphere rotating in quiescent air was measured experimentally over the range Re = 0 - 33,320 from free to forced convection regimes. As well, real time holographic interferometry was applied to the observation of flows structure and evolution, and later employed to analyze the deviations revealed by a comparison of the measured data (ANN) with previous experimental and theoretical results. Thus, real time holographic visualization provides a physical understanding of the effect of the evolving flow structure on ANN as rotational speed increases. In addition, a new asymptotic formula for correlating the experimentally measured ANN was established.
Holographic investigation on average Nusselt number over an isothermal rotating sphere
NASA Astrophysics Data System (ADS)
Tieng, Sheng-Mao; Yan, An-Cherng
1997-04-01
The average Nusselt number of a heated sphere rotating in quiescent air was measured experimentally over the range 0 < Re < 33320 from free to forced convection regimes. As well, real time holographic interferometry was applied to the observation of flows structure and evolution, and later employed to analyze the deviations revealed by a comparison of the measured data Nu with previous experimental and theoretical results. Thus, real time holographic visualization provides a physical understanding of the effect of the evolving flow structure on Nu as rotational speed increases. In addition, a new asymptotic formula for correlating the experimentally measured Nu was established.
Entanglement Rényi entropies in holographic theories
Matthew Headrick; Martin Fisher
2010-01-01
Ryu and Takayanagi conjectured a formula for the entanglement (von Neumann) entropy of an arbitrary spatial region in an arbitrary holographic field theory. The von Neumann entropy is a special case of a more general class of entropies called Rényi entropies. Using Euclidean gravity, Fursaev computed the entanglement Rényi entropies (EREs) of an arbitrary spatial region in an arbitrary holographic
Holographic optical elements as scanning lidar telescopes
Geary K. Schwemmer; Richard D. Rallison; Thomas D. Wilkerson; David V. Guerra
2006-01-01
We have developed and investigated the use of holographic optical elements (HOEs) and holographic transmission gratings for scanning lidar telescopes. Rotating a flat HOE in its own plane with the focal spot on the rotation axis makes a very simple and compact conical scanning telescope. We developed transmission and reflection HOEs for use at the first three harmonic wavelengths of
Strange meson form factors in holographic QCD
H. Z. Sang; Xiao-Hong Wu
2010-01-01
We consider the electromagnetic form factors of strange vector, axial vector and pseudoscalar mesons in a holographic QCD model. We find the charge radius of charged kaon agrees with the experiment, while the charge radius of charged pion is a little bit smaller than the experimental value, as obtained in other calculations in the hard-wall holographic QCD models. The charge
Uncertainty quantification for holographic interferographic images
Laurie Ann Centauri
2010-01-01
Current comparison methods for experimental and simulated holographic interferometric images are qualitative in nature. Previous comparisons of holographic interferometric images with computational fluid dynamics (CFD) simulations for validation have been performed qualitatively through visual comparison by a data analyst. By validating the experiments and CFD simulations in a quantifiable manner using a consistency analysis, the validation becomes a repeatable process
Display applications for holographic optical elements
William J. Gambogi; Mark L. Armstrong; Babak Hamzavy; Michael L. Levin; Steven R. Mackara; William J. Molteni; Kirk W. Steijn; Sylvia H. Stevenson; Thomas C. Felder; Gerald L. Heidt; Douglas R. Miller
2001-01-01
In the last several years, holographic elements have been introduced into a wide array of display applications. Holographic Reflectors are incorporated with liquid crystal displays to shift optimum viewing angle away form specular glare and raise brightness by concentrating light at a convenient viewing angle. Reflectors can be produced in blue, green, gold, red, or white colors. Denso GlassVision projection
Application of holographic interferometry for plasma diagnostics
1986-01-01
The principle of holographic interferometry is described and its importance for plasma diagnostics is indicated, particularly for the determination of electron concentration (Section 2). A review is given of different methods for increasing the sensitivity associated with penetration into the infrared region of the spectrum, and also with the use of multiple-pass, resonance, dispersive nonlinear and two-wavelength holographic interferometry. Section
Holographic recording of laser-induced plasma
Martin Centurion; Ye Pu; Zhiwen Liu; Demetri Psaltis; Theodor W. Hänsch
2004-01-01
We report on a holographic probing technique that allows for measurement of free-electron distribution with fine spatial detail. Plasma is generated by focusing a femtosecond pulse in air. We also demonstrate the capability of the holographic technique of capturing the time evolution of the plasma-generation process.
Developments in holographic-based scanner designs
David M. Rowe
Holographic-based scanning systems have been used for years in the high resolution prepress markets where monochromatic lasers are generally utilized. However, until recently, due to the dispersive properties of holographic optical elements (HOEs), along with the high cost associated with recording \\
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
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
Holographic memory based on computer generated Fourier-holograms
NASA Astrophysics Data System (ADS)
Odinokov, Sergey; Bobrinev, Vladimir; Verenikina, Nina; Zherdev, Alexander; Lushnikov, Dmitriy; Markin, Vladimir; Betin, Aleksander; Zlokazov, Evgeny; Starikov, Rostislav; Evtikhiev, Nikolay; Starikov, Sergey
2013-05-01
Classic holographic memory systems use two-beam approach based on fixation of interference pattern between object and reference coherent beams on holographic recording medium. The size of single pattern is about several micrometers. High precision optical set up is required to form such a microhologram, that is the reason of excessive price for holographic recording devices. Methods of computer holographic synthesis allow to calculate holographic patterns numerically as 2D images. These images can be realized with the use of spatial light modulator, then reduced in optical projection system and exposed on holographic medium. In this paper we represent the research of holographic memory system based on computer generated Fourier holograms projection.
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, which are important details for proper description of EDL properties. In this thesis, we implement an efficient and accurate classical solvation density functional theory (CDSFT) for EDLs of spherical macroions and cylindrical polyelectrolytes embedded in aqueous electrolytes. This approach extends the capabilities of mean field approximations by taking into account electrostatic ion-ion correlations, size asymmetry and excluded volume effects without compromising the computational cost. We apply the computational tool to study the structural and thermodynamic properties of the ionic atmosphere around B-DNA and spherical nanoparticles. We demonstrate that the presence of solvent molecules at experimental concentration and size values has a significant impact on the layering of ions. This layering directly influences the integrated charge and mean electrostatic potential in the diffuse region of the spherical electrical double layer (SEDL) and have a noticeable impact on the behavior of zeta potential (ZP). Recently, we have extended the aforementioned CSDFT to account for the charge-regulated mechanisms of the macroion surface on the structural and thermodynamic properties of spherical EDLs. In the approach, the CSDFT is combined with a surface complexation model to account for ion correlation and excluded volume effects on the surface titration of spherical macroions. We apply the proposed computational approach to describe the role that the ion size and solvent excluded volume play on the surface titration properties of silica nanoparticles. We analyze the effects of the nanoparticle size, pH and salt concentration of the aqueous solution on the nanoparticle's surface charge and zeta potential. The results reveal that surface charge density and zeta potential significantly depend on excluded volume and ion-ion correlation effects as well as on pH for monovalent ion species at high salt concentrations. Overall, our results are in good agreement with Monte Carlo simulations and available experimental data. We discuss future directions of this work, which incl
Osher, David E.; Beach, Sara D.; Cyr, Abigail B.; Ozernov-Palchik, Ola; Yendiki, Anastasia; Fischl, Bruce; Gaab, Nadine; Gabrieli, John D.E.
2013-01-01
Developmental dyslexia, an unexplained difficulty in learning to read, has been associated with alterations in white matter organization as measured by diffusion-weighted imaging. It is unknown, however, whether these differences in structural connectivity are related to the cause of dyslexia or if they are consequences of reading difficulty (e.g., less reading experience or compensatory brain organization). Here, in 40 kindergartners who had received little or no reading instruction, we examined the relation between behavioral predictors of dyslexia and white matter organization in left arcuate fasciculus, inferior longitudinal fasciculus, and the parietal portion of the superior longitudinal fasciculus using probabilistic tractography. Higher composite phonological awareness scores were significantly and positively correlated with the volume of the arcuate fasciculus, but not with other tracts. Two other behavioral predictors of dyslexia, rapid naming and letter knowledge, did not correlate with volumes or diffusion values in these tracts. The volume and fractional anisotropy of the left arcuate showed a particularly strong positive correlation with a phoneme blending test. Whole-brain regressions of behavioral scores with diffusion measures confirmed the unique relation between phonological awareness and the left arcuate. These findings indicate that the left arcuate fasciculus, which connects anterior and posterior language regions of the human brain and which has been previously associated with reading ability in older individuals, is already smaller and has less integrity in kindergartners who are at risk for dyslexia because of poor phonological awareness. These findings suggest a structural basis of behavioral risk for dyslexia that predates reading instruction. PMID:23946384
NASA Astrophysics Data System (ADS)
Luo, Xiaofeng; Xu, Ji; Mohanty, Bedangadas; Xu, Nu
2013-10-01
Moments (variance (?2), skewness (S), kurtosis (?)) of multiplicity distributions of conserved quantities, such as net-baryon, net-charge and net-strangeness, are predicted to be sensitive to the correlation length of the system and connected to the thermodynamic susceptibilities computed in the Lattice QCD and Hadron Resonance Gas model. In this paper, we present several measurement artifacts that could lead to volume fluctuation and auto-correlation effects in the moment analysis of net-proton multiplicity distributions in heavy-ion collisions using the ultra-relativistic quantum molecular dynamics model. We discuss methods to overcome these artifacts so that the extracted moments can be used to obtain physical conclusions. In addition, we present methods to properly estimate the statistical errors in moment analysis.
NASA Astrophysics Data System (ADS)
Grignani, G.; Karczmarek, J. L.; Semenoff, G. W.
2013-12-01
We consider the Polyakov loop operator in finite temperature planar N = 4 supersymmetric Yang-Mills theory defined on a spatial S3 and in representations where the number of boxes in the Young Tableau k is large and scales so that kN remains finite in the large N limit. We review the argument that, in the de-confined phase of the gauge theory, and for symmetric representations with row Young tableau, there is a quantum phase transition in the expectation value of the Polyakov loop operator which occurs as the size of the representation is increased beyond a critical value of kN. We also argue that for completely antisymmetric representations with column tableau, there is no such phase transition. The AdS/CFT dual of such large representation loops are thought to be probe D-branes with k units of fundamental string charge dissolved in their world-volumes. Our results for both symmetric and antisymmetric representations are consistent with what is known about these branes on the thermal AdS black hole background.
Sofiane Benyahia; Madhava Syamlal; Thomas J. O'Brien
2006-01-01
Hill et al. [R. J. Hill, D.L. Koch, J.C. Ladd, J. Fluid Mech. (2001), 448, pp. 213–241 and 243–278] proposed a set of drag correlations, based on data from Lattice–Boltzmann simulations. These correlations, while very accurate within the range of void fractions and Reynolds numbers used in the Lattice–Boltzmann simulations, do not cover the full range of void fractions and
Chang-Won Shin; Viet-Tien Vu; Nam Kim; Jun-Won An; Dongwoo Suh; Hojun Rue; Mun-Cheol Paek; Hyeon-Bong Pyo
2005-01-01
A new structure for polarization-selective elements, consisting of two holographic gratings and a Dove prism coupler, is proposed. The absence of a multistage waveguide and the benefits of compact size and lightweight volume are the outstanding features of the new structure. Based on the coupled-wave theory, the analysis and design of the structure are discussed in detail to calculate the
Holographic Storage of Biphoton Entanglement
Han-Ning Dai; Han Zhang; Sheng-Jun Yang; Tian-Ming Zhao; Jun Rui; You-Jin Deng; Li Li; Nai-Le Liu; Shuai Chen; Xiao-Hui Bao; Xian-Min Jin; Bo Zhao; Jian-Wei Pan
2012-04-06
Coherent and reversible storage of multi-photon entanglement with a multimode quantum memory is essential for scalable all-optical quantum information processing. Although single photon has been successfully stored in different quantum systems, storage of multi-photon entanglement remains challenging because of the critical requirement for coherent control of photonic entanglement source, multimode quantum memory, and quantum interface between them. Here we demonstrate a coherent and reversible storage of biphoton Bell-type entanglement with a holographic multimode atomic-ensemble-based quantum memory. The retrieved biphoton entanglement violates Bell's inequality for 1 microsecond storage time and a memory-process fidelity of 98% is demonstrated by quantum state tomography.
Artist Projects at Holographics North
NASA Astrophysics Data System (ADS)
Perry, John, Dr
2013-02-01
The New York Times has declared the concept of holography in art as "laughably dated". And yet fine art remains one of the most durable applications of the medium. Holographics North Inc. has produced work for over 50 artists in 28 years. In many cases, new techniques and systems were required in order to implement the client's vision. The technical and conceptual challenges involved in several of these projects will be discussed, including photos of the work and the systems built to produce it. Among the artists addressed will be James Turrell, Michael Snow, Frank Stella, Michael Hayden, Harriet Casdin-Silver and Chris Levine.
Gauss-Bonnet Holographic Superconductors
Luke Barclay; Ruth Gregory; Sugumi Kanno; Paul Sutcliffe
2010-09-24
We study holographic superconductors in five dimensional Einstein-Gauss-Bonnet gravity both numerically and analytically. We find the critical temperature of the superconductor decreases as backreaction is increased, although the effect of the Gauss-Bonnet coupling is more subtle: the critical temperature first decreases then increases as the coupling tends towards the Chern-Simons value in a backreaction dependent fashion. We compute the conductivity of the system, finding the energy gap, and show that the effect of both backreaction and higher curvature is to increase the gap ratio $\\omega_g/T_c$, thus there is no universal relation for these superconductors.
On Holographic Insulators and Supersolids
Kiritsis, Elias
2015-01-01
We obtain holographic realisations for systems that have strong similarities to Mott insulators and supersolids, after examining the ground states of Einstein-Maxwell-scalar systems. The real part of the AC conductivity has a hard gap and a discrete spectrum only. We add momentum dissipation to resolve the delta function in the conductivity due to translational invariance. We develop tools to directly calculate the Drude weight for a large class of solutions and to support our claims. Numerical RG flows are also constructed to verify that such saddle points are IR fixed points of asymptotically AdS_4 geometries.
Holographic Viscosity of Fundamental Matter
David Mateos; Robert C. Myers; Rowan M. Thomson
2006-10-16
A holographic dual of a finite-temperature SU(N_c) gauge theory with a small number of flavours N_f viscosity to entropy ratio in these theories saturates the conjectured universal bound eta/s >= 1/4\\pi. The contribution of the fundamental matter eta_fund is therefore enhanced at strong 't Hooft coupling lambda; for example, eta_fund ~ lambda N_c N_f T^3 in four dimensions. Other transport coefficients are analogously enhanced. These results hold with or without a baryon number chemical potential.
Cai, Rong-Gen; Zhang, Hai-Qing
2013-01-01
We construct a holographic model of superconducting quantum interference device (SQUID) in the Einstein-Maxwell-complex scalar theory with a negative cosmological constant. The SQUID ring consists of two Josephson junctions which sit on two sides of a compactified spatial direction of a Schwarzschild-AdS black brane. These two junctions interfere with each other and then result in a total current depending on the magnetic flux, which can be deduced from the phase differences of the two Josephson junctions. The relation between the total current and the magnetic flux is obtained numerically.
Rong-Gen Cai; Yong-Qiang Wang; Hai-Qing Zhang
2013-12-16
We construct a holographic model of superconducting quantum interference device (SQUID) in the Einstein-Maxwell-complex scalar theory with a negative cosmological constant. The SQUID ring consists of two Josephson junctions which sit on two sides of a compactified spatial direction of a Schwarzschild-AdS black brane. These two junctions interfere with each other and then result in a total current depending on the magnetic flux, which can be deduced from the phase differences of the two Josephson junctions. The relation between the total current and the magnetic flux is obtained numerically.
Universality of abrupt holographic quenches.
Buchel, Alex; Myers, Robert C; van Niekerk, Anton
2013-11-15
We make an analytic investigation of rapid quenches of relevant operators in d-dimensional holographic conformal field theories, which admit a dual gravity description. We uncover a universal scaling behavior in the response of the system, which depends only on the conformal dimension of the quenched operator in the vicinity of the ultraviolet fixed point of the theory. Unless the amplitude of the quench is scaled appropriately, the work done on a system during the quench diverges in the limit of abrupt quenches for operators with dimension (d/2)??
Holographic bounds and finite inflation
Daniel Phillips; Andrew Scacco; Andreas Albrecht
2014-10-13
We compare two holographic arguments that impose especially strong bounds on the amount of inflation. One comes from the de Sitter Equilibrium cosmology and the other from the work of Banks and Fischler. We find that simple versions of these two approaches yield the same bound on the number of e-foldings. A careful examination reveals that while these pictures are similar in spirit, they are not necessarily identical prescriptions. We apply the two pictures to specific cosmologies which expose potentially important differences and which also demonstrate ways these seemingly simple proposals can be tricky to implement in practice.
Haussler, Stephane [Frankfurt Institute for Advanced Studies (FIAS), Johann Wolfgang Goethe Universitaet, Max-von-Laue-Strasse 1, D-60438 Frankfurt (Germany); Stoecker, Horst [Frankfurt Institute for Advanced Studies (FIAS), Johann Wolfgang Goethe Universitaet, Max-von-Laue-Strasse 1, D-60438 Frankfurt (Germany); Institut fuer Theoretische Physik, Johann Wolfgang Goethe Universitaet, Max-von-Laue-Strasse 1, D-60438 Frankfurt (Germany); Bleicher, Marcus [Institut fuer Theoretische Physik, Johann Wolfgang Goethe Universitaet, Max-von-Laue-Strasse 1, D-60438 Frankfurt (Germany)
2006-02-15
The recently proposed baryon-strangeness correlation (C{sub BS}) is studied with a string-hadronic transport model (UrQMD) for various energies from E{sub lab}=4A GeV to {radical}(s)=200A GeV. It is shown that rescattering among secondaries cannot mimic the predicted correlation pattern expected for a quark-gluon-plasma. However, we find a strong increase of the C{sub BS} correlation function with decreasing collision energy for p+p and Au+Au and/or Pb+Pb reactions. For Au+Au reactions at the top BNL Relativistic Heavy Ion Collider energy ({radical}(s)=200A GeV), the C{sub BS} correlation is constant for all centralities and compatible with the p+p result. With increasing width of the rapidity window, C{sub BS} follows roughly the shape of the baryon rapidity distribution. We suggest studying the energy and centrality dependence of C{sub BS} to gain information on the onset of the deconfinement transition in temperature and volume.
Kiruluta, Andrew J M; Anderson, Ken; Barbastathis, George
2006-06-01
The fundamental nuclear magnetic resonance (NMR) imaging equation can be derived from a spatial-spectral holographic wavefront reconstruction formulation similar to that in quantum optics. A spatial-spectral holographic interpretation arises naturally in NMR from the inhomogeneous linewidth broadening due to either an imposed set of linear orthogonal gradient fields or from the intrinsic chemical anisotropy of the spin system. We can thus think of NMR k-space as a spatial-spectral holographic grating. The spatial holographic component arises from dielectric effects at high field strength (>4 T) when the excitation wavelength is less than or commensurate with the size of the imaging sample. The holographic properties of storage, time-reversal, recognition, and triple correlations are experimentally demonstrated in an inhomogeneously broadened NMR sample. This holographic NMR interpretation has additional implications on selective radio-frequency pulse design, microscopy imaging, and the use of conjugate imaging for field inhomogeneity corrections using the time-reversed component of the readout, to be the subject of a subsequent paper. PMID:16715158
NASA Astrophysics Data System (ADS)
Kiruluta, Andrew J. M.; Anderson, Ken; Barbastathis, George
2006-06-01
The fundamental nuclear magnetic resonance (NMR) imaging equation can be derived from a spatial-spectral holographic wavefront reconstruction formulation similar to that in quantum optics. A spatial-spectral holographic interpretation arises naturally in NMR from the inhomogeneous linewidth broadening due to either an imposed set of linear orthogonal gradient fields or from the intrinsic chemical anisotropy of the spin system. We can thus think of NMR k-space as a spatial-spectral holographic grating. The spatial holographic component arises from dielectric effects at high field strength (>4 T) when the excitation wavelength is less than or commensurate with the size of the imaging sample. The holographic properties of storage, time-reversal, recognition, and triple correlations are experimentally demonstrated in an inhomogeneously broadened NMR sample. This holographic NMR interpretation has additional implications on selective radio-frequency pulse design, microscopy imaging, and the use of conjugate imaging for field inhomogeneity corrections using the time-reversed component of the readout, to be the subject of a subsequent paper.
Analyticity and the Holographic S-Matrix
Fitzpatrick, A.Liam; /Stanford U., Phys. Dept.; 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.
Unitarity and the Holographic S-Matrix
Fitzpatrick, A.Liam; /Stanford U., Phys. Dept.; 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.
Holographic measurements of refractive-index changes.
Politch, J; Segal, M
1978-07-01
We consider here a new method for identifying changes in the index of refraction. A birefringent material was illuminated directly, without a diffuser, and recorded holographically in one step. An unpolarized TEM(00) continuous-wave laser, which emits elliptically polarized light on the time-average scale, was applied in this experiment. With such a holographic recording system three types of reconstruction for the same object are possible, off-axis with laser, off-axis with white light, and on-axis with laser (Gabor hologram). Properties of the holographic recording system and reconstruction of images by the first two of these methods are discussed. PMID:19684687
Holographic Duals of 4D Field Theories
M. Porrati; A. Starinets
2000-09-25
We discuss various aspect of the holographic correspondence between 5-d gravity and 4-d field theory. First of all, we describe deformations of N=4 Super Yang-Mills (SYM) theories in terms of 5-d gauged supergravity. In particular, we describe N=0 and N=1 deformations of N=4 SYM to confining theories. Secondly, we describe recent proposals for the holographic dual of the renormalization group and for 4-d central charges associated to it. We conclude with a ``holographic'' proof of the Goldstone theorem.
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.
Holographic characterization of fulgides doped polymer films
NASA Astrophysics Data System (ADS)
Lafond, Christophe; Bolte, Michel; Lessard, Roger A.
2003-02-01
Dynamic holographic recording was performed on two fulgides (A540 and A670)/Doped films. Maximum diffraction efficiency of 7% and 6% has been achieved on A540 and A670 doped PEPC/PS films. The effects of the matrix, writing intensity and film thickness on diffraction efficiency were studied. Holographic fatigue resistance in polymer matrix and epoxy resin has been investigated. It was found that holographic fatigue of fulgide doped in epoxy resin is closed to zero at least after 40 Write-Read-Erase cycles (WRE).
Holographic Foam, Dark Energy and Infinite Statistics
Y. Jack Ng
2007-09-30
Quantum fluctuations of spacetime give rise to quantum foam, and black hole physics dictates that the foam is of holographic type. Applied to cosmology, the holographic model requires the existence of dark energy which, we argue, is composed of an enormous number of inert ``particles'' of extremely long wavelength. These "particles" necessarily obey infinite statistics in which all representations of the particle permutation group can occur. For every boson or fermion in the present observable universe there could be $\\sim 10^{31}$ such "particles". We also discuss the compatibility between the holographic principle and infinite statistics.
Acrylamide-adhesive as holographic recording medium
NASA Astrophysics Data System (ADS)
Toxqui-López, S.; Olivares-Pérez, A.; Fuentes-Tapia, I.
2013-03-01
In recent years, many types of polymers have been used in different recording holographic medium due their relatively low cost and some of them are be self-developing needing no wet processing or thermal treatment. Therefore, in this research recording materials based on Acrylamide-adhesive polymer matrix layer are prepared by gravity settling method after time drying, the layers are characterized by recording transmission holographic gratings ( LSR 445 NL 445 nm) and measuring the first order diffraction efficiency holographic parameter. This recording material has good diffraction efficiency and environmental stability.
Minimal Holographic Superconductors from Maximal Supergravity
Nikolay Bobev; Arnab Kundu; Krzysztof Pilch; Nicholas P. Warner
2011-10-16
We study a truncation of four-dimensional maximal gauged supergravity that provides a realization of the minimal model of a holographic superconductor. We find various flow solutions in this truncation at zero and finite temperature with a non-trivial profile for the charged scalar. Below a critical temperature we find holographic superconductor solutions that represent the thermodynamically preferred phase. Depending on the choice of boundary conditions, the superconducting phase transition is either first or second order. For vanishing temperature we find a flow with a condensing charged scalar that interpolates between two perturbatively stable AdS_4 vacua and is the zero-temperature ground state of the holographic superconductor.
Tamiya, Hiroyuki; Miyakawa, Megumi; Takeshita, Akira; Miura, Daishu; Takeuchi, Yasuhiro
2014-09-17
There are few reports on parathyroid ultrasonography of multiple endocrine neoplasia type 1 (MEN1). This study investigated the ultrasonographic features of parathyroid glands in 10 patients with MEN1 who underwent preoperative neck ultrasonography and parathyroidectomy between 2006 and 2010 at Toranomon Hospital. We retrospectively analyzed clinical features, laboratory and ultrasonographic data, and pathological diagnosis. A total of 38 parathyroid glands were surgically removed (three to five glands from each patient). All removed parathyroids were pathologically diagnosed as hyperplasia. Seven cases (70.0 %) had adenomatous thyroid nodules. Twenty-five enlarged parathyroid glands (65.8 %) were detected by preoperative ultrasonography with a detection rate of 81.8 % (9/11) and 59.3 % (16/27) for patients without and with adenomatous nodules, respectively. Total parathyroid gland weight and potentially predictable total parathyroid volume by preoperative ultrasonography were significantly correlated with preoperative serum intact parathyroid hormone (iPTH) concentration (R = 0.97, P < 0.001 and R = 0.96, P < 0.001, respectively). The equation used for prediction of the total volume by ultrasonography was 15 × iPTH (pg/ml) - 1,000 and that for total weight was 20 × iPTH (pg/ml) - 1,400. Although adenomatous nodules often coexisted with MEN1 and made identification of enlarged parathyroid glands by ultrasonography difficult, the positive correlation between the predictable parathyroid volume by ultrasonography and serum iPTH suggests that their measurement is useful in the preoperative detection and localization of enlarged parathyroid glands in patients with MEN1. Furthermore, the presence of parathyroid glands that should be resected can be predicted before surgery using the equation proposed here. PMID:25227285
Holographic QCD with Dynamical Flavors
Francesco Bigazzi; Aldo L. Cotrone
2015-01-22
Gravity solutions describing the Witten-Sakai-Sugimoto model of holographic QCD with dynamical flavors are presented. The field theory is studied in the Veneziano limit, at first order in the ratio of the number of flavors and colors. The gravity solutions are analytic and dual to the field theory either in the confined, low temperature phase or in the deconfined, high temperature phase with small baryonic charge density. The phase diagram and the flavor contributions to vacuum (e.g. string tension and hadron masses) and thermodynamical properties of the dual field theory are then deduced. The phase diagram of the model at finite temperature and imaginary chemical potential, as well as that of the unflavored theory at finite theta angle are also discussed in turn, showing qualitative similarities with recent lattice studies. Interesting degrees of freedom in each phase are discussed. Covariant counterterms for the Witten-Sakai-Sugimoto model are provided both in the probe approximation and in the backreacted case, allowing for a standard holographic renormalization of the theory.
Holographic opto-fluidic microscopy
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
NASA Astrophysics Data System (ADS)
Veniaminov, A. V.; Mahilny, U. V.
2013-12-01
We present a review of information that has been published in the scientific literature on the mechanism of formation (development, enhancement) of holograms at the expense of the photochemical attachment of phenanthrenequinone molecules and other compounds to polymer chains and diffusion mixing of unreacted molecules, on different types of light-sensitive materials that realize this mechanism, on the application of these materials to create volume holographic elements, on recording of information, and for research purposes.
The holographic dual of AdS 3 × S3 × S3 × S1
NASA Astrophysics Data System (ADS)
Tong, David
2014-04-01
We construct the two dimensional = (0, 4) gauge theory that lives on the world volume of D1-branes and intersecting D5-branes. We conjecture that this theory flows in the infra-red to a fixed point with large = (4, 4) superconformal symmetry. The central charge of the conformal field theory is shown to coincide with the holographic dual of string theory compactified on AdS 3 × S 3 × S 3 × S 1.
Aoki, Masahiko; Takai, Yoshihiro; Narita, Yuichiro; Hirose, Katsumi; Sato, Mariko; Akimoto, Hiroyoshi; Kawaguchi, Hideo; Hatayama, Yoshiomi; Miura, Hiroyuki; Ono, Shuichi
2014-01-01
The purpose of this study was to investigate the relationship between tumor size and blood volume for patients with lung tumors, using dual-energy computed tomography (DECT) and a gemstone spectral imaging (GSI) viewer. During the period from March 2011 to March 2013, 50 patients with 57 medically inoperable lung tumors underwent DECT before stereotactic body radiotherapy (SBRT) of 50–60 Gy in 5–6 fractions. DECT was taken for pretreatment evaluation. The region-of-interest for a given spatial placement of the tumors was set, and averages for CT value, water density and iodine density were compared with tumor size. The average values for iodine density in tumors of ?2 cm, 2–3 cm, and >3 cm maximum diameter were 24.7, 19.6 and 16.0 (100 µg/cm3), respectively. The average value of the iodine density was significantly lower in larger tumors. No significant correlation was detected between tumor size and average CT value or between tumor size and average water density. Both the average water density and the average CT value were affected by the amount of air in the tumor, but the average iodine density was not affected by air in the tumor. The average water density and the average CT value were significantly correlated, but the average iodine density and the average CT value showed no significant correlation. The blood volume of tumors can be indicated by the average iodine density more accurately than it can by the average CT value. The average iodine density as assessed by DECT might be a non-invasive and quantitative assessment of the radio-resistance ascribable to the hypoxic cell population in a tumor. PMID:24829253
Digital holographic imaging of aquatic species
Domínguez-Caballero, José Antonio
2006-01-01
The aim of this thesis is to design, develop and implement a digital holographic imaging (DHI) system, capable of capturing three-dimensional (3D) images of aquatic species. The images produced by this system are used in ...
Holographic non-Fermi-liquid fixed points
Faulkner, Tom
Techniques arising from string theory can be used to study assemblies of strongly interacting fermions. Via this ‘holographic duality’, various strongly coupled many-body systems are solved using an auxiliary theory of ...
Entanglement growth during thermalization in holographic systems
Liu, Hong
We derive in detail several universal features in the time evolution of entanglement entropy and other nonlocal observables in quenched holographic systems. The quenches are such that a spatially uniform density of energy ...
Holographic Vortex Liquids and Superfluid Turbulence
Chesler, Paul M.
Superfluid turbulence is a fascinating phenomenon for which a satisfactory theoretical framework is lacking. Holographic duality provides a systematic approach to studying such quantum turbulence by mapping the dynamics ...
Towards a non-relativistic holographic superfluid
Adams, Allan
We explore the phase structure of a holographic toy model of superfluid states in non-relativistic conformal field theories. At low background mass density, we found a familiar second-order transition to a superfluid phase ...
Disordered holographic systems: Marginal relevance of imperfection
Adams, Allan
We continue our study of quenched disorder in holographic systems, focusing on the effects of mild electric disorder. By studying the renormalization group evolution of the disorder distribution at subleading order in ...
Entanglement Tsunami: Universal Scaling in Holographic Thermalization
Liu, Hong
We consider the time evolution of entanglement entropy after a global quench in a strongly coupled holographic system, whose subsequent equilibration is described in the gravity dual by the gravitational collapse of a thin ...
Emergence in Holographic Scenarios for Gravity
Dieks, Dennis; de Haro, Sebastian
2015-01-01
'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 straightfowardly instantiates emergence. However, assuming a non-standard interpretation of AdS/CFT may create room for the emergence of spacetime and ...
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)
G-corrected holographic dark energy model
Malekjani, M
2013-01-01
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.
Meson wave function from holographic approaches
Vega, Alfredo; Schmidt, Ivan [Departamento de Fisica y Centro de Estudios Subatomicos, Universidad Tecnica Federico Santa Maria, Casilla 110-V, Valparaiso (Chile); Branz, Tanja; Gutsche, Thomas; Lyubovitskij, Valery E. [Institut fuer Theoretische Physik, Universitaet Tuebingen, Kepler Center for Astro and Particle Physics, Auf der Morgenstelle 14, D-72076 Tuebingen (Germany)
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.
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.
Charge transport by holographic Fermi surfaces
Faulkner, Thomas
We compute the contribution to the conductivity from holographic Fermi surfaces obtained from probe fermions in an AdS charged black hole. This requires calculating a certain part of the one-loop correction to a vector ...
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.
Holographic description of quantum field theory
Sung-Sik Lee
2010-01-01
We propose that general D-dimensional quantum field theories are dual to (D+1)-dimensional local quantum theories which in general include objects with spin two or higher. Using a general prescription, we construct a (D+1)-dimensional theory which is holographically dual to the D-dimensional O(N) vector model. From the holographic theory, the phase transition and critical properties of the model in dimensions D>2
Holographic Mutual Information at small separations
Cesar A. Agon; Howard J. Schnitzer
2015-02-10
The holographic mutual information for the small separation of two circles and two strips in 2+1 dimensional space-time is considered based on the known exact minimal surfaces spanning the boundaries on AdS4. The results suggest a universality for the leading term in the short-distance expansion of holographic mutual information. A conjecture for a similar result for d > 2 is also presented, as well as comments about the analogous expansion in conformal field theory.
Holographic Space-Time: The Takeaway
T. Banks
2011-01-01
The theory of holographic space-time (HST) generalizes both string theory and quantum field theory. 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 non-commutative geometrical variables on a holographic screen. Compact extra dimensions are interpreted as finite dimensional unitary
Soft wall model for a holographic superconductor
S. S. Afonin; I. V. Pusenkov
2015-06-17
We apply the soft wall holographic model from hadron physics to a description of the high-$T_c$ superconductivity. In comparison with the existing bottom-up holographic superconductors, the proposed approach is more phenomenological. On the other hand, it is much simpler and has more freedom for fitting the conductivity properties of the real high-$T_c$ materials. We demonstrate some examples of emerging models and discuss a possible origin of the approach.
Soft wall model for a holographic superconductor
Afonin, S S
2015-01-01
We apply the soft wall holographic model from hadron physics to a description of the high-$T_c$ superconductivity. In comparison with the existing bottom-up holographic superconductors, the proposed approach is more phenomenological. On the other hand, it is much simpler and has more freedom for fitting the conductivity properties of the real high-$T_c$ materials. We demonstrate some examples of emerging models and discuss a possible origin of the approach.
Lateral resolution of digital holographic system
Huaying Wang; Hongjun Wei; Yi Wang; Jie Zhao; Dayong Wang
2008-01-01
Based on Fresnel diffraction theory, the point spread function (PSF) of the off-axis lensless Fourier transform digital holographic system with pre-magnification is deduced for the first time to the best of our knowledge. The limited lateral resolutions of the digital holographic systems with and without pre-magnification are analyzed in detail. For lensless Fourier digital holography, the expression of the limit
Distributed synthetic apertures for digital holographic imaging
Yue Gao; Da-Yong Wang; Hua-Kun Cui; Zhi-Wei Zhou; Yun-Xin Wang
2011-01-01
A key problem for the digital holography is to improve the resolution of digital holographic system. We present a system for long-range digital holographic imaging with improved resolution using synthetic aperture method. Imaging system is formed by three sub-apertures, and each sub-aperture receiver contains independently telescope lenses and a CCD device. Through every sub-aperture system, a hologram is obtained. Subsequently,
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.
Towards a Holographic Dual of SQCD: Holographic Anomalies and Higher Derivative Gravity
James Babington
2005-12-19
We consider the holographic dual of SQCD in the conformal phase. It is based on a higher derivative gravity theory, which ensures the correct field theory anomalies. This is then related to a six dimensional gravity theory via S^1 compactification. Some speculations are then made about the correspondence, Seiberg duality, and the nature of confinement from a holographic perspective.
Holographic Brownian Motion in Two Dimensional Rotating Fluid
Ardian Nata Atmaja
2013-03-15
The Brownian motion of a heavy quark under a rotating plasma corresponds to BTZ black hole is studied using holographic method from string theory. The position of heavy quark is represented as the end of string at the boundary of BTZ black hole and the corresponding rotating plasma is one dimensional compact space. We requires the angular velocity of the string fluctuation to be equal to the ratio between inner horizon and outer horizon, called terminal angular velocity, which is related to the zero total force condition. We show the displacement square of this solution behaves as a Brownian particle in non-relativistic limit. For relativistic case, we argue that it is more appropriate to compute the leading order of low frequency limit of random-random force correlator. The Brownian motion relates this correlator with physical observables: effective mass of the Brownian particle, friction coefficient, and temperature of the plasma.
Studies of optical systems containing liquid crystals and holographic optical elements
NASA Astrophysics Data System (ADS)
Montbach, Erica Nicole
Optical retarders are generally produced from homogeneous crystals or stretched polymer films. The birefringence and dispersion properties of those films are primarily controlled by the molecular structure of the material. Unfortunately, the resulting properties may not be what are desired for a particular application. For example, in the case where retardation films are designed to compensate liquid crystals for improved display devices, the dispersion characteristics of the retarder often do not match that of the liquid crystal. However, retarders based on form birefringence have the potential for greater control of material properties, such as birefringence and dispersion. The transmission of electromagnetic waves through both slanted and unslanted volume holographic retarders, in the form birefringent regime, is calculated. The material parameters of the holographic retarders are varied and the resulting effect on birefringence is presented. Significantly, it is shown that the dispersion properties of these retarders can be adjusted over a large wavelength range. Further, the design of a retarder with improved properties that ideally compensate the optical properties of a liquid crystal layer is shown. A vertically aligned (VA) LCD is compensated using unslanted holographic retarders in the form birefringent regime. A twisted nematic (TN) LCD is compensated using stacked, dispersion matched, slanted holographic retarders. The Berreman method is ideal for calculating the transmission or reflection of electromagnetic waves through unslanted volume holograms since they are composed of layers of varying index. However, slanted volume holograms require a calculation method that will allow index variations at some angle to the hologram's normal; therefore, a method for calculating light propagation through a system of numerous different stacks, which do not have parallel layers of constant permittivity tensor, is developed to allow these calculations. This new extension of the Berreman method is also used to calculate the reflection of electromagnetic waves from both slanted and unslanted volume holograms, in the Bragg regime. Since the Berreman method allows for an arbitrary dielectric profile, holographic reflectors are evaluated with square, sinusoidal, or irregular morphologies. The model is applied to the specific case of chirped photopolymer gratings. The Berreman method also allows for uniaxial layers, which permits the investigation of birefringence in the hologram layers. A slanted holographic reflector is included in a reflective, single polarizer, low twist liquid crystal display (LCD), designed for active matrix. The LCD is optimized for the off axis angle of the holographic slanted reflector. A slanted holographic reflector is also included in a reflective, single polarizer, high twist LCD, designed for passive matrix. The high twist display is optimized using a new method that considers the variables of the LC layer without the added variables of the polarizer and retarders. This method calculates the polarization states through out the LCD and compares those polarizations to find the optimum display. This method is more generally applicable then previous optimization methods and does not require any additional changes when considering a holographic slanted reflector (HSR) in place of a plane mirror.
Excited Baryons in Holographic QCD
de Teramond, Guy F.; /Costa Rica U.; 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.
Holographic Viscosity of Fundamental Matter
Mateos, David [Department of Physics, University of California, Santa Barbara, California 93106-9530 (United States); Myers, Robert C. [Kavli Institute for Theoretical Physics, University of California, Santa Barbara, California 93106-4030 (United States); Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2L 2Y5 (Canada); Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada); Thomson, Rowan M. [Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2L 2Y5 (Canada); Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)
2007-03-09
A holographic dual of a finite-temperature SU(N{sub c}) gauge theory with a small number of flavors N{sub f}<
Limitations of holographic grating lenses
NASA Astrophysics Data System (ADS)
Yao, S. K.
1981-01-01
The design aspects and the main parameters of periodic gratings in planar optical waveguides manufactured by holographic techniques are discussed. In particular, it is shown that there is a limitation on the size of the grating K-vector and the Bragg angle tolerance if low device insertion loss is desired. Typical index differences between the waveguide mode and the substrate mode is about 0.005 for a TI diffused LiNbO3 crystal and is less than 0.3 for sputtered thin-film waveguides on silicon or glass substrates. Thus, the maximum Bragg angle is approximately eight degrees for LiNbO3 and less than 45 degrees for glass or silicon substrates. The reflection angle for the optical beam is twice the Bragg angle. In order to achieve a large field of view, the grating periodicity should be optimized for each substrate parameter.
Holographic Cosmology from BIonic Solutions
Sepehri, Alireza; Setare, Mohammad Reza; Ali, Ahmed Farag
2015-01-01
In this paper, we will use a BIonic solution for analysing the holographic cosmology. A BIonic solution is a configuration of a D-brane and an anti-D-brane connected by a wormhole. A BIonic configuration can form due to a transition of fundamental black strings. After the BIon has formed, the wormhole in the BIon will act act as a channel for the energy to flow into the D3-brane. This will increase the degrees of freedom of the D3-brane causing inflation. The inflation will end when the wormhole gets annihilated. However, as the distance between the D3-brane and the anti-D3-brane reduces, tachyonic states get created. These tachyonic states will lead to the formation of a new wormhole. This new wormhole will again increasing the degrees of freedom on the D3-brane causing late time acceleration.
Electromagnetic instability in holographic QCD
NASA Astrophysics Data System (ADS)
Hashimoto, Koji; Oka, Takashi; Sonoda, Akihiko
2015-06-01
Using the AdS/CFT correspondence, we calculate the vacuum decay rate for the Schwinger effect in confining large N c gauge theories. The instability is induced by thecorrespondence, we calculate the vacuum quark antiquark pair creation triggered by strong electromagnetic fields. The decay rate is obtained as the imaginary part of the Euler-Heisenberg effective Lagrangian evaluated from the D-brane action with a constant electromagnetic field in holographic QCD models such as the Sakai-Sugimoto model and the deformed Sakai-Sugimoto model. The decay rate is found to increase with the magnetic field parallel to the electric field, while it decreases with the magnetic field perpendicular to the electric field. We discuss generic features of a critical electric field as a function of the magnetic field and the QCD string tension in the Sakai-Sugimoto model.
Super-fast refresh holographic liquid crystals for holographic 3D display
NASA Astrophysics Data System (ADS)
Gao, Hongyue; Yu, Yingjie; Liu, Jicheng; Zeng, Chao; Liu, Pan; Yao, Qiuxiang; Zheng, Huadong
2015-03-01
Doped liquid crystals, as super-fast refresh holographic media, are very useful in holographic 3D video display because of their extraordinarily high optical nonlinearity arising from laser-induced director axis reorientation. We obtained real-time dynamic holographic display with holographic response time under an order of a microsecond using the super-fast-response liquid crystal films. The hologram formation time and self-erasable time can both reach ~ 1 ms in this film. Holographic video display was realized using them without any cross talk between the holograms. In this paper, the mechanism of real-time hologram recording and self-erasure will be presented based on light-induced liquid crystal molecular reorientation in the films.
Dynamic joint transform correlator of images
NASA Astrophysics Data System (ADS)
Angervaks, A. E.; Malyi, A. F.; Fedorov, I. U.; Shcheulin, A. S.
2008-03-01
In this article principles of operation of a coherent optical image correlator based on a well know optical joint transform correlator are examined. Theoretical predictions and experimental data for of the optical image correlator with a holographic filter recorded on a thin holographic photographic plates PFG - 01 are analyzed. Results of the operation of the dynamic joint transform correlator on the basis of cadmium fluoride crystal, CdF2, with bistable impurity centers are demonstrated. Calculated and experimental correlation peak intensity dependencies with the scale and angular mismatch between an observed and reference objects for static and dynamic joint transform correlators are compared. Tangram figures were used as a test images. In the paper all computations were performed by use of MATLAB 7.0.1 mathematical program.
Research activities on digital holographic displays in Japan
Hiroshi Yoshikawa
2011-01-01
Recently, researches on digital holographic 3D display are getting very active as well as the digital holography for 3D image acquisition. This paper reviews recent research activities in Japan, including digital holographic 3D video displays, digital holographic fringe printers and computer-generated holograms. The holographic video display includes 100 megapixel full-color full-parallax display, horizontal scanning display, enlarged viewing angle display. For
Integrated holographic filters for flat passband optical multiplexers.
Iazikov, D; Greiner, C M; Mossberg, T W
2006-04-17
Lithographically rendered, slab-waveguide-based, volume holographic filters are shown, via fabrication and test, capable of providing fully integrated, single-mode compatible, flat-topped and low loss filtering for wide bandwidth multiplexers as, for example, used in coarse wave-division multiplexing (CWDM). Single-mode compatibility is preserved since the filters operate via multi-path interference like thin-film filters rather than the angular dispersion typically utilized by grating type devices. Flexible apodization, entirely consistent with simple binary etch, is employed to provide steep passband falloff. High reflectivity and wide bandwidth is enabled through a tailored dual core waveguide geometry providing for mode concentration on the diffractive elements. PMID:19516496
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.
Holographic memory module with ultra-high capacity and throughput
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.
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.
Energy collection efficiency of low concentration holographic planar concentrators
Raymond K. Kostuk; Jose Castro; Deming Zhang
2010-01-01
Abstract In this presentation we evaluate the energy collection efficiency and energy yield of different holographic planar concentrator designs. The holographic planar concentrator replaces expensive photovoltaic cell material with holographic collectors that cost approximately 1% of the photovoltaic material. An analysis is performed using a combination of raytracing and coupled wave theory. Other loss factors such as Fresnel reflection and
Signature Theory in Holographic Algorithms Jin-Yi Cai
Cai, Jin-Yi
Signature Theory in Holographic Algorithms Jin-Yi Cai Computer Sciences Department University University Beijing, 100084, P. R. China lpy@mails.tsinghua.edu.cn Abstract In the theory of holographic substantially develop the signature theory in holographic algo- rithms. This theory is developed in terms of d
Studies on the holographic antenna: Theories and experiments
Ying Li; Qi Zhu; Ruiming Mo
2011-01-01
Based on the principles of constructing holographic antenna, the interference of the radiation fields of source antenna and the ideal plane wave is analyzed. Consequently, the positions of the holographic structure are determined. Furthermore the expressions of the positions of the holographic structure are achieved by simplifying the calculation of the minima of the interference fields. As examples, one-dimensional, two-dimensional
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…
New methods in real-time holographic interferometry
Zhengrong Wang; Bingheng Xiong; Yongan Zhang; Canlin She
1996-01-01
Some new methods in real-time holographic interferometry are presented in this paper, such as how to obtain a high contrast of interference fringes in real-time holographic interferometry at the stage of recording or reconstruction; how to predict the deformation direction of an object by a simple and reliable method etc. These techniques are helpful for holographers to improve the precision
Future of photorefractive based holographic 3D display
P.-A. Blanche; A. Bablumian; R. Voorakaranam; C. Christenson; D. Lemieux; J. Thomas; R. A. Norwood; M. Yamamoto; N. Peyghambarian
2010-01-01
The very first demonstration of our refreshable holographic display based on photorefractive polymer was published in Nature early 20081. Based on the unique properties of a new organic photorefractive material and the holographic stereography technique, this display addressed a gap between large static holograms printed in permanent media (photopolymers) and small real time holographic systems like the MIT holovideo. Applications
Spatial Frequency Response of Acrylamide Based Holographic Photopolymer
Raghavendra Jallapuram; Izabela Naydenova; Vincent Toal; Suzanne Martin; Robert Howard
2003-01-01
It has been shown that photopolymers are useful in holographic optical elements [1] and holographic interferometry [2]. However, the list of potential applications increases greatly if reflection holography is possible. Reflection holography requires a material that has the potential to record high spatial frequencies. Here we studied the spatial frequency response of an acrylamide based dye sensitized holographic photopolymer. We
Langevin diffusion of heavy quarks in non-conformal holographic backgrounds
U. Gursoy; E. Kiritsis; L. Mazzanti; F. Nitti
2010-12-27
The Langevin diffusion process of a relativistic heavy quark in a non-conformal holographic setup is discussed. The bulk geometry is a general, five-dimensional asymptotically AdS black hole. The heavy quark is described by a trailing string attached to a flavor brane, moving at constant velocity. From the equations describing linearized fluctuations of the string world-sheet, the correlation functions defining a generalized Langevin process are constructed via the AdS/CFT prescription. In the local limit, analytic expressions for the Langevin diffusion and friction coefficients are obtained in terms of the bulk string metric. Modified Einstein relations between these quantities are also derived. The spectral densities associated to the Langevin correlators are analyzed, and simple analytic expressions are obtained in the small and large frequency limits. Finally, a numerical analysis of the jet-quenching parameter, and a comparison to RHIC phenomenology are performed in the case of Improved Holographic QCD.
Dykman, Mark
VOLUME 86, NUMBER 11 P H Y S I C A L R E V I E W L E T T E R S 12 MARCH 2001 Enhancement of Tunneling from a Correlated 2D Electron System by a Many-Electron MÃ¶ssbauer-Type Recoil in a Magnetic Field, New Jersey 07974 (Received 19 July 2000) We consider the effect of electron correlations on tunneling
Dye-doped PQ-PMMA phase holographic materials for DFB lasing
NASA Astrophysics Data System (ADS)
Gritsai, Y.; Sakhno, O.; Goldenberg, L. M.; Stumpe, J.
2014-03-01
Phase holographic materials based on phenanthrenquinone (PQ) in poly(methylmethacrylate) (PMMA) matrices additionally doped with laser dyes (LD) have been developed and investigated. It was found that the holographic properties of the dye-doped materials are almost the same as that of pure PQ-PMMA. In particular, the amplification of the holographic gratings due to post-exposure diffusion was demonstrated. An amplitude of the refractive index modulation of about 3 × 10-3 was achieved for the enhanced gratings with periods in the range of 0.3-30 ?m. Homogeneous distribution of PQ and LD in the enhanced gratings was found by means of a microscope-spectrometer. Such doped volume gratings can be used for different optical and photonic applications. As one possible application of the gratings distributed feedback lasing was tested. A narrow-band second-order laser emission has been demonstrated in 18 ?m thick volume gratings based on optimized PQ-PMMA materials doped with pyrromethene laser dyes.
Holographic fluorescence microscopy with incoherent digital holographic adaptive optics.
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. PMID:26146767
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.
Compact holographic optical neural network system for real-time pattern recognition
NASA Astrophysics Data System (ADS)
Lu, Taiwei; Mintzer, David T.; Kostrzewski, Andrew A.; Lin, Freddie S.
1996-08-01
One of the important characteristics of artificial neural networks is their capability for massive interconnection and parallel processing. Recently, specialized electronic neural network processors and VLSI neural chips have been introduced in the commercial market. The number of parallel channels they can handle is limited because of the limited parallel interconnections that can be implemented with 1D electronic wires. High-resolution pattern recognition problems can require a large number of neurons for parallel processing of an image. This paper describes a holographic optical neural network (HONN) that is based on high- resolution volume holographic materials and is capable of performing massive 3D parallel interconnection of tens of thousands of neurons. A HONN with more than 16,000 neurons packaged in an attache case has been developed. Rotation- shift-scale-invariant pattern recognition operations have been demonstrated with this system. System parameters such as the signal-to-noise ratio, dynamic range, and processing speed are discussed.
Temperature dependence and characterization of gratings in PQ/PMMA holographic materials
NASA Astrophysics Data System (ADS)
Russo, Juan M.; Chen, Chia-Hung; Kostuk, Raymond K.
2006-08-01
The good optical properties of PQ (phenanthrenequinone)-doped PMMA (poly methylmethacrylate) and the ability to form it in a wide range of substrate configurations makes it attractive as a holographic recording material. Previously Wavelength Division Multiplexing (WDM) and Optical Code Division Multiple Access (OCDMA) filters were demonstrated in this material operating near 1550 nm using edge-illuminated geometry. In this paper we investigate the temperature dependence of edge-illuminated holographic filters formed in PQ/PMMA. It was found that both the volume and refractive index of the material changes as a function of temperature. It was also found that changes to the refractive index dominate the wavelength selectivity of the grating. Experimental measurements and a theoretical model for the grating behavior as a function of temperature are presented.
Holographic data storage with a planar-integrated optical write-read head
NASA Astrophysics Data System (ADS)
Soellner, Matthias; Vieth, Udo; Hsu, Ken Yuh; Lin, Shiuan Huei; Gruber, Matthias
2009-05-01
The construction of a write-once-read-many-type optical write-read-head for volume holographic data storage in disk-based photopolymer storage media is discussed. Its design is based on the photonic integration concept called planar-integrated free-space optics. A proof-of-principle demonstrator was fabricated, it contains a 3mm thick fused silica wafer that carries most passive components for the reference and the signal beam relay in the form of diffractive optical elements, a translucent liquid crystal microdisplay, and the CCD sensor of a webcam. Phenanthrenequinone-doped polymethylmethacrylate was chosen as storage material, a DPSS laser with ? = 532nm serves as light source. We report about preliminary experiments to determine suitable exposure parameters for holographic write-read operations, and on the use of data matrix codes for the encoding and decoding of information.
A holographic improvement to traditional Optical Array Probes
NASA Astrophysics Data System (ADS)
Fugal, Jacob; Borrmann, Stephan
2015-04-01
Optical Array Probes have been used to measure cloud droplets and ice crystals in the size range of ~10 µm up to ~1 cm for about the last four decades. In this type of instrument, particles are swept past a focused laser sheet imaged onto a linear diode array. The resulting image has a single spatial axis and a time axis and thereby has shadowgraphs of the particles swept through and can then infer their size and shape, and therefrom size distributions, liquid water content, ice water content, and so on. One weakness inherent in the method is the difficulty in measuring small particles (~10 to 200µm in size) which appear out of focus or are not detected at all, depending on how far from the focus of the laser sheet they appear in the sensitive region. Out-of-focus small particles appear as a diffraction rings or doughnuts making the particles appear large than they actually are. Also the region in which the instrument is sensitive to small particles or depth-of-focus region is difficult to estimate making number concentrations and size distributions difficult to measure. On the other hand, holographic sample volumes are well defined as the sensitive region spans the entire area in which particles appear and the particles appearing in the holograms are reconstructed to their focus position. I.e. there is no depth-of-focus problem and the particles are sized in their focus position. Current holographic cloud particle probes use two-dimensional cameras that take snapshots of cloud particles having two spatial dimensions. These probes have also been high-resolution which requires high-performance servers to do the reconstruction and particle finding meaning the results of the measurements come long after the holograms are made. Of great advantage might be a low-resolution holographic probe with a spatial axis and a time axis with real-time results. Shown is that simple modifications to existing optical array probes such as a collimated laser sheet and a grayscale sensor, and a simple low-resolution holographic reconstruction technique can be used to remove the depth of focus and the over-sizing problem from an optical array probe of similar configuration. It is hypothesised that for low enough resolution and flight speeds, the hologram reconstruction and particle finding algorithm could be implemented realtime on an FPGA. It is shown that only a few grayscales are necessary to make holograms of sufficient quality. Discussed is the sensitivity of smallest detectable particle size and sample volume depth are to the detector size. Also discussed is that one would obtain a rough estimate of the third spatial position of small particles in the sample volume resulting in a better resolved view of the structure of the cloud.
Mukamel, Shaul
VOLUME 77, NUMBER 16 P H Y S I C A L R E V I E W L E T T E R S 14 OCTOBER 1996 Femtosecond Spectroscopic Signatures of Electronic Correlations in Conjugated Polyenes and Semiconductor Nanostructures T and Engineering, University of Rochester, Rochester, New York 14627 (Received 25 March 1996) Electronic
Holographic stress tensor at finite coupling
NASA Astrophysics Data System (ADS)
Sen, Kallol; Sinha, Aninda
2014-07-01
We calculate one, two and three point functions of the holographic stress tensor for any bulk Lagrangian of the form ?( g ab , R abcd , ? e R abcd ). Using the first law of entanglement, a simple method has recently been proposed to compute the holographic stress tensor arising from a higher derivative gravity dual. The stress tensor is proportional to a dimension dependent factor which depends on the higher derivative couplings. In this paper, we identify this proportionality constant with a B-type trace anomaly in even dimensions for any bulk Lagrangian of the above form. This in turn relates to , the coefficient appearing in the two point function of stress tensors. We use a background field method to compute the two and three point function of stress tensors for any bulk Lagrangian of the above form in arbitrary dimensions. As an application we consider general situations where ?/s for holographic plasmas is less than the KSS bound.
From spacetime foam to holographic foam cosmology
Michele Arzano; Thomas W. Kephart; Y. Jack Ng
2006-05-22
Due to quantum fluctuations, spacetime is foamy on small scales. For maximum spatial resolution of the geometry of spacetime, the holographic model of spacetime foam stipulates that the uncertainty or fluctuation of distance $l$ is given, on the average, by $(l l_P^2)^{1/3}$ where $l_P$ is the Planck length. Applied to cosmology, it predicts that the cosmic energy is of critical density and the cosmic entropy is the maximum allowed by the holographic principle. In addition, it requires the existence of unconventional (dark) energy/matter and accelerating cosmic expansion in the present era. We will argue that a holographic foam cosmology of this type has the potential to become a full fledged competitor (with distinct testable consequences) for scalar driven inflation.
Exact holographic mapping in free fermion systems
Ching Hua Lee; Xiao-Liang Qi
2015-05-15
In this paper, we shall 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. Our 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 nontrivial dynamic 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.
Exact holographic mapping in free fermion systems
Lee, Ching Hua
2015-01-01
In this paper, we shall 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. Our 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 nontrivial dynamic 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.
Holographic Principle and Quantum Physics
Batiz, Z; Batiz, Zoltan; Chauhan, Bhag C.
2006-01-01
The concept of holography has lured philosophers of science for decades, and is becoming more and more popular on several fronts of science, e. g. in the physics of black holes. In this paper we try to understand things as if the visible universe were a reading of a low-dimensional hologram generated in hyperspace. We performed the whole process of creating and reading the hologram of a point in virtual space by using computer simulations. We claim that the fuzzieness in quantum mechanics, in statistical physics and thermodynamics is due to the fact that we do not see the real image of the object, but a holographic projection of it. We found that the projection of a point particle is a de Broglie-type wave. This indicates that holography could be the origin of the wave nature of a particle. We have also noted that one cannot stabilize the noise (or fuzzieness) in terms of the integration grid-points of the hologram, it means that one needs to give the grid-points a physical significance. So we further claim t...
Supertranslations and holographic stress tensor
NASA Astrophysics Data System (ADS)
Virmani, Amitabh
2012-02-01
It is well known in the context of four dimensional asymptotically flat space-times that the leading order boundary metric must be conformal to unit de Sitter metric when hyperbolic cutoffs are used. This situation is very different from asymptotically AdS settings where one is allowed to choose an arbitrary boundary metric. The closest one can come to changing the boundary metric in the asymptotically flat context, while maintaining the group of asymptotic symmetries to be Poincaré, is to change the so-called `supertranslation frame' ?. The most studied choice corresponds to taking ? = 0. In this paper we study consequences of making alternative choices. We perform this analysis in the covariant phase space approach as well as in the holographic renormalization approach. We show that all choices for ? are allowed in the sense that the covariant phase space is well defined irrespective of how we choose to fix supertranslations. The on-shell action and the leading order boundary stress tensor are insensitive to the supertranslation frame. The next to leading order boundary stress tensor depends on the supertranslation frame but only in a way that the transformation of angular momentum under translations continues to hold as in special relativity.
Brodsky, Stanley J.; /SLAC /Southern Denmark U., CP3-Origins; 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-front QCD Hamiltonian 'Light-Front Holography'. Light-Front Holography is in fact one of the most remarkable features of the AdS/CFT correspondence. The Hamiltonian equation of motion in the light-front (LF) is frame independent and has a structure similar to eigenmode equations in AdS space. This makes a direct connection of QCD with AdS/CFT methods possible. Remarkably, the AdS equations correspond to the kinetic energy terms of the partons inside a hadron, whereas the interaction terms build confinement and correspond to the truncation of AdS space in an effective dual gravity approximation. One can also study the gauge/gravity duality starting from the bound-state structure of hadrons in QCD quantized in the light-front. The LF Lorentz-invariant Hamiltonian equation for the relativistic bound-state system is P{sub {mu}}P{sup {mu}}|{psi}(P)> = (P{sup +}P{sup -} - P{sub {perpendicular}}{sup 2})|{psi}(P)> = M{sup 2}|{psi}(P)>, P{sup {+-}} = P{sup 0} {+-} P{sup 3}, where the LF time evolution operator P{sup -} is determined canonically from the QCD Lagrangian. To a first semiclassical approximation, where quantum loops and quark masses are not included, this leads to a LF Hamiltonian equation which describes the bound-state dynamics of light hadrons in terms of an invariant impact variable {zeta} which measures the separation of the partons within the hadron at equal light-front time {tau} = x{sup 0} + x{sup 3}. This allows us to identify the holographic variable z in AdS space with an impact variable {zeta}. The resulting Lorentz-invariant Schroedinger equation for general spin incorporates color confinement and is systematically improvable. Light-front holographic methods were originally introduced by matching the electromagnetic current matrix elements in AdS space with the corresponding expression using LF theory in physical space time. It was also shown that one obtains identical holographic mapping using the matrix elements of the energy-momentum tensor by perturbing the AdS metric around its static solution. A gravity dual to QCD is not known, but th
Holographic Thermalization with Chemical Potential
Elena Caceres; Arnab Kundu
2012-05-25
We study the thermalization of a strongly coupled quantum field theory in the presence of a chemical potential. More precisely, using the holographic prescription, we calculate non- local operators such as two point function, Wilson loop and entanglement entropy in a time- dependent background that interpolates between AdSd+1 and AdSd+1 -Reissner-Nordstr\\"om for d = 3, 4. We find that it is the entanglement entropy that thermalizes the latest and thus sets a time-scale for equilibration in the field theory. We study the dependence of the thermalization time on the probe length and the chemical potential. We find an interesting non-monotonic behavior. For a fixed small value of T l and small values of \\mu/T the thermalization time decreases as we increase \\mu/T, thus the plasma thermalizes faster. For large values of \\mu/T the dependence changes and the thermalization time increases with increasing \\mu/T . On the other hand, if we increase the value of T l this non-monotonic behavior becomes less pronounced and eventually disappears indicating two different regimes for the physics of thermalization: non-monotonic dependence of the thermalization time on the chemical potential for T l > 1.
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.
Kovács, Attila; Oláh, Attila; Lux, Árpád; Mátyás, Csaba; Németh, Balázs Tamás; Kellermayer, Dalma; Ruppert, Mihály; Török, Marianna; Szabó, Lilla; Meltzer, Anna; Assabiny, Alexandra; Birtalan, Ede; Merkely, Béla; Radovits, Tamás
2015-04-01
Contractile function is considered to be precisely measurable only by invasive hemodynamics. We aimed to correlate strain values measured by speckle-tracking echocardiography (STE) with sensitive contractility parameters of pressure-volume (P-V) analysis in a rat model of exercise-induced left ventricular (LV) hypertrophy. LV hypertrophy was induced in rats by swim training and was compared with untrained controls. Echocardiography was performed using a 13-MHz linear transducer to obtain LV long- and short-axis recordings for STE analysis (GE EchoPAC). Global longitudinal (GLS) and circumferential strain (GCS) and longitudinal (LSr) and circumferential systolic strain rate (CSr) were measured. LV P-V analysis was performed using a pressure-conductance microcatheter, and load-independent contractility indices [slope of the end-systolic P-V relationship (ESPVR), preload recruitable stroke work (PRSW), and maximal dP/dt-end-diastolic volume relationship (dP/dtmax-EDV)] were calculated. Trained rats had increased LV mass index (trained vs. control; 2.76 ± 0.07 vs. 2.14 ± 0.05 g/kg, P < 0.001). P-V loop-derived contractility parameters were significantly improved in the trained group (ESPVR: 3.58 ± 0.22 vs. 2.51 ± 0.11 mmHg/?l; PRSW: 131 ± 4 vs. 104 ± 2 mmHg, P < 0.01). Strain and strain rate parameters were also supernormal in trained rats (GLS: -18.8 ± 0.3 vs. -15.8 ± 0.4%; LSr: -5.0 ± 0.2 vs. -4.1 ± 0.1 Hz; GCS: -18.9 ± 0.8 vs. -14.9 ± 0.6%; CSr: -4.9 ± 0.2 vs. -3.8 ± 0.2 Hz, P < 0.01). ESPVR correlated with GLS (r = -0.71) and LSr (r = -0.53) and robustly with GCS (r = -0.83) and CSr (r = -0.75, all P < 0.05). PRSW was strongly related to GLS (r = -0.64) and LSr (r = -0.71, both P < 0.01). STE can be a feasible and useful method for animal experiments. In our rat model, strain and strain rate parameters closely reflected the improvement in intrinsic contractile function induced by exercise training. PMID:25617359
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.
Holographic currents and Chern-Simons terms
Clark, T. E.; Love, S. T.; Veldhuis, T. ter [Department of Physics, Purdue University, West Lafayette, Indiana 47907-2036 (United States); Department of Physics and Astronomy, Macalester College, Saint Paul, Minnesota 55105-1899 (United States)
2010-11-15
Holographic currents and their associated Ward identities are derived in the framework of gravity/gauge duality. Holographic improvements of the energy-momentum tensor and R-symmetry current which are consistent with the Ward identities are displayed. The effects of specific string loop corrections to the bulk action are included as four derivative effective Lagrangian terms and their contributions to the trace and R-symmetry anomalies of the boundary theory are determined. As an example, the construction is applied to the N=2 conformal supergravity which is taken to be dual to a boundary SU(N)xSU(N), N=1 superconformal field theory.
On the Holographic Nature Of Rindler Energy
Edi Halyo
2014-06-22
We show that the dimensionless Rindler energy of a black hole, $E_R$, is exactly the surface Hamiltonian obtained from the Einstein--Hilbert action evaluated on the horizon. Therefore, $E_R$ is given by a surface integral over the horizon and manifestly holographic. In the context of the AdS/CFT duality, Rindler energy corresponds, on the boundary, to a dimensionless energy given by the product of the AdS radius and the extensive part of the CFT energy. We find that, beyond General Relativity, $E_R$ is still holographic but not necessarily given by the surface Hamiltonian of the theory.
Holographic Dark Energy Model: State Finder Parameters
Nairwita Mazumder; Ritabrata Biswas; Subenoy Chakraborty
2011-10-30
In this work, we have studied interacting holographic dark energy model in the background of FRW model of the universe. The interaction is chosen either in linear combination or in product form of the matter densities for dark matter and dark energy. The IR cut off for holographic dark energy is chosen as Ricci's length scale or radius of the future event horizon. The analysis is done using the state finder parameter and coincidence problem has been graphically presented. Finally, universal thermodynamics has been studied using state finder parameters.
Shape of mesons in holographic QCD
Torabian, Mahdi; Yee, Ho-Ung [Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, 34014, Trieste (Italy)
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.
Holographic RG flows with nematic IR phases
Cremonini, Sera; Rong, Junchen; Sun, Kai
2014-01-01
We construct zero-temperature geometries that interpolate between a Lifshitz fixed point in the UV and an IR phase that breaks spatial rotations but preserves translations. We work with a simple holographic model describing two massive gauge fields coupled to gravity and a neutral scalar. Our construction can be used to describe RG flows in non-relativistic, strongly coupled quantum systems with nematic order in the IR. In particular, when the dynamical critical exponent of the UV fixed point is z=2 and the IR scaling exponents are chosen appropriately, our model realizes holographically the scaling properties of the bosonic modes of the quadratic band crossing model.
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.
Holographic Two-Point Functions in Conformal Gravity
Ahmad Ghodsi; Behnoush Khavari; Ali Naseh
2015-01-27
In this paper we compute the holographic two-point functions of four dimensional conformal gravity. Precisely we calculate the two-point functions for Energy- Momentum (EM) and Partially Massless Response (PMR) operators that have been identified as two response functions for two independent sources in the dual CFT. The correlation function of EM with PMR tensors turns out to be zero which is expected according to the conformal symmetry. The two-point function of EM is that of a transverse and traceless tensor, and the two-point function of PMR which is a traceless operator contains two distinct parts, one for a transverse-traceless tensor operator and another one for a vector field, both of which fulfill criteria of a CFT. We also discuss about the unitarity of the theory.
Improved model of vector mesons in holographic QCD
Alvares, Raul; Hoyos, Carlos; Karch, Andreas [School of Physics and Astronomy, Southampton University, Southampton, SO17 1BJ (United Kingdom); Department of Physics, University of Washington, Seattle, Washington 98915-1560 (United States)
2011-11-01
We analyze the sector of dimension-three vector meson operators in the 'hard-wall' model of holographic QCD, including the vector and axial currents, dual to gauge fields in the bulk, and the tensor operator {psi}{sigma}{sup {mu}{nu}{psi}}, dual to a two-form field satisfying a complex self-duality condition. The model includes the effect of chiral symmetry breaking on vector mesons, that involves a coupling between the dual gauge field and the two-form field. We compute the leading logarithmic terms in the operator product expansion of two-point functions and the leading nonperturbative contribution to the tensor-vector correlator. The result is consistent with the operator product expansion of QCD. We also study the spectrum of vector mesons numerically.
Wide-angle color holographic 3D display with multi-source-based holographic content
NASA Astrophysics Data System (ADS)
Zaperty, Weronika; Kujawinska, Malgorzata; Kozacki, Tomasz; Wisniowski, Bartosz
2015-03-01
In this paper we present a wide viewing angle multi SLMs color holographic 3D display. An extended viewing angle is provided by the use of circular setup configuration. To ensure best utilization of spatial bandwidth of a single SLM a temporal multiplexing method for a color reconstruction is applied. Averaged in time modulated component wavefronts overlap in space and create a real color 3D image. We present the display implementation resulting in color reconstruction of computer generated objects and multi-view 2D real object stereogram converted into holographic representation. The applicability of this approach to allow holographic display of big 3D scenes and the future possibilities to extend the spatio-temporal bandwidth of color holographic displays are discussed.
NASA Astrophysics Data System (ADS)
Germaneau, A.; Peyruseigt, F.; Mistou, S.; Doumalin, P.; Dupré, J.-C.
2010-06-01
On Airbus aircraft, spherical plain bearings are used on many components; in particular to link engine to pylon or pylon to wing. Design of bearings is based on contact pressure distribution on spherical surfaces. To determine this distribution, a 3D analysis of the mechanical behaviour of aeronautical plain bearing is presented in this paper. A numerical model has been built and validated from a comparison with 3D experimental measurements of kinematic components. For that, digital volume correlation (DVC) coupled with optical scanning tomography (OST) is employed to study the mechanical response of a plain bearing model made in epoxy resin. Experimental results have been compared with the ones obtained from the simulated model. This comparison enables us to study the influence of various boundary conditions to build the FE model. Some factors have been highlighted like the fitting behaviour which can radically change contact pressure distribution. This work shows the contribution of a representative mechanical environment to study precisely mechanical response of aeronautical plain bearings.
Real-Time Correlators and Non-Relativistic Holography
Robert G. Leigh; Nam Nguyen Hoang
2009-09-02
We consider Lorentzian correlation functions in theories with non-relativistic Schrodinger symmetry. We employ the method developed by Skenderis and van Rees in which the contour in complex time defining a given correlation function is associated holographically with the gluing together of Euclidean and Lorentzian patches of spacetimes. This formalism extends appropriately to geometries with Schrodinger isometry.
Holographic analysis as an inspection method for welded thin-wall tubing
NASA Technical Reports Server (NTRS)
Brooks, Lawrence; Mulholland, John; Genin, Joseph; Matthews, Larryl
1990-01-01
The feasibility of using holographic interferometry for locating flaws in welded tubing is explored. Two holographic techniques are considered: traditional holographic interferometry and electronic speckle pattern interferometry. Several flaws including cold laps, discontinuities, and tube misalignments are detected.
Optical studies in the holographic ground station
Gary L. Workman
1991-01-01
The Holographic Group System (HGS) Facility in rooms 22 & 123, Building 4708 has been developed to provide for ground based research in determining pre-flight parameters and analyzing the results from space experiments. The University of Alabama, Huntsville (UAH) has researched the analysis aspects of the HGS and reports their findings here. Some of the results presented here also occur
Creating a three dimensional holographic movie
Guerra, Marvin J
2008-01-01
An experimental study was carried out on the ability to create a three-dimensional holographic movie. Holograms were written on VRP-M emulsion film with the green line of an Argon-Ion laser. The type of hologram write setup ...
M theory as a holographic field theory
Petr Horava
1999-01-01
We suggest that M theory could be nonperturbatively equivalent to a local quantum field theory. More precisely, we present a ``renormalizable'' gauge theory in eleven dimensions, and show that it exhibits various properties expected of quantum M theory, most notably the holographic principle of 't Hooft and Susskind. The theory also satisfies Mach's principle: A macroscopically large space-time (and the
Holographic Theories of Inflation and Fluctuations
Tom Banks; Willy Fischler
2011-12-06
The theory of holographic space-time (HST) generalizes both string theory and quantum field theory. 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 non-commutative 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 $\\Lambda^{1/4}$. We present a holographic theory of inflation and fluctuations. The inflaton field is an emergent concept, describing the geometry of an underlying HST model, rather than "a field associated with a microscopic string theory". We argue that the phrase in quotes is meaningless in the HST formalism.
Corner contributions to holographic entanglement entropy
Bueno, Pablo
2015-01-01
The entanglement entropy of three-dimensional conformal field theories contains a universal contribution coming from corners in the entangling surface. We study these contributions in a holographic framework and, in particular, we consider the effects of higher curvature interactions in the bulk gravity theory. We find that for all of our holographic models, the corner contribution is only modified by an overall factor but the functional dependence on the opening angle is not modified by the new gravitational interactions. We also compare the dependence of the corner term on the new gravitational couplings to that for a number of other physical quantities, and we show that the ratio of the corner contribution over the central charge appearing in the two-point function of the stress tensor is a universal function for all of the holographic theories studied here. Comparing this holographic result to the analogous functions for free CFT's, we find fairly good agreement across the full range of the opening angle....
Bergson and the holographic theory of mind
Stephen E. Robbins
2006-01-01
Bergson’s model of time (1889) is perhaps the proto-phenomenological theory. It is part of a larger model of mind (1896) which can be seen in modern light as describing the brain as supporting a modulated wave within a holographic field, specifying the external image of the world, and wherein subject and object are differentiated not in terms of space, but
Holographic motion picture: theory and observations
H. Sasaki; K. Karaki; M. Mitsunaga; N. Uesugi
1995-01-01
We develop a full density-matrix theory describing the holographic motion picture, the direct recording of a real moving image into an inhomogeneous spectrum of a medium using spectral hole burning. The main emphasis is on the time resolution of the movie. It is concluded that, with a frequency scan rate faster than the square inverse of the characteristic time of
Gauged supergravity and holographic field theory
Nick Warner
2003-01-01
This is a slightly expanded version of my talk at Future Perspectives in Theoretical Physics and Cosmology, Stephen Hawking's 60th Birthday Worshop. I describe some of the issues that were important in gauged supergravity in the 1980's and how these, and related issues have once again become important in the study of holographic field theories.
Holographic metals and fractionalized Fermi liquids
Subir Sachdev
2011-01-01
I show that there is a close correspondence between the physical properties of holographic metals near charged black holes in anti-de Sitter (AdS) space, and the fractionalized Fermi liquid phase of the lattice Anderson model. The latter phase has a \\
Low holographic concentration effects on CIGS
Jose E. Castillo; Juan M. Russo; Deming Zhang; Raymond K. Kostuk; Glenn A. Rosenberg
2010-01-01
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
Thermal stress studies using optical holographic interferometry
NASA Technical Reports Server (NTRS)
Harris, W. J.; Woods, D. C.
1974-01-01
The application of holography to thermal stress studies is discussed. Interference fringes as produced by holograms and their interpretation are reviewed in relation to workpiece displacement. Three potential mechanisms are given to explain thermal displacement as detected by holographic methods. Results of some thermal stressing studies are reported, including tests on a live rocket motor.
Compact scanning lidar systems using holographic optics
Geary K. Schwemmer; Thomas D. Wilkerson; David Guerra
1998-01-01
Two scanning lidar systems have been built using holographic optical elements (HOE) that function as a scanning telescope primary optic. One is a ground based lidar using a reflection HOE, and uses a frequency doubled Nd:YAG laser transmitter. The other system is an airborne\\/ground based system that uses a transmission HOE and operates at the 1064 nm fundamental of the
Holographic Algorithms Jin-Yi Cai
Cai, Jin-Yi
. At the same time, the correctness and efficiency of this and similar algorithms demand proofs in a purelyHolographic Algorithms Jin-Yi Cai Computer Sciences Department University of Wisconsin Madison, WI algorithms. These novel algorithms achieve exponential speed-ups for certain computational problems compared
High sensitive materials in medical holographic microscopy
NASA Astrophysics Data System (ADS)
Osanlou, A.; Snashall, E.; Osanlou, O.; Osanlou, R.; Mirlis, E.; Shi, Lishen; Bjelkhagen, H.
2015-02-01
High sensitivity is defined in relation to the energy required to perform holographic recording. High sensitivity in silver halide materials is their main advantage over other similarly high resolving power holographic recording materials. This work reports progress on the development of silver halide based 'true colour holographic imaging', under a microscope. A thin layer of ultrafine grains of silver halide crystals of around 10 nm average diameter, dispersed in a colloid and coated on a substrate is used as the recording media. The significance of this method so far, is in its ability to produce 'true colour' three-dimensional images of specimen. The recordings have an appreciable depth, permitting the observer to scan through the image under a microscope, as one might with a real specimen sample. Current methods could perform ' True colour holographic imaging' directly under a microscope. The recording methodology has the potential for deeper complex and scattering media imaging, using very small pulses of appropriate laser wavelengths. The methodology, using novel nanosize panchromatic recording media consisting of dispersed fine nano grain crystals, could potentially revolutionise related medical imaging techniques. Future development of digital media will allow it to be utilized in this manner.
The Rainmaker's Reality and the Holographic Archetype
Joseph W. Burke
2007-01-01
Recalling the rainmaker story often told by Jung, this article connects the rainmaker's view of reality with a holographic archetype. In the story, rain comes to a drought-stricken area of China when a rainmaker gets in Tao, in order, within himself. He insists he is not responsible for the rain, though the villagers sent for him due to his reputation
Image Deformation of Holographic Code Transformation
Shun-ichi Tanaka; Sanshiro Hattori
1973-01-01
Holographic code transformation of signals u and v is theoretically treated, and the deformations in the transformed images of Fresnel, lensless Fourier and Fourier transform types are compared. Examples of the numerical calculation where u and v have a rectangular shape of equal width show that the case where lensless Fourier transformation is performed in the first step and Fourier
Dynamic digital holographic interferometry with three wavelengths
Nazif Demoli; Dalibor Vukicevic; Marc Torzynski
2003-01-01
A color digital holographic interferometry movie was produced by applying the subtraction digital holography method in a quasi-Fourier off-axis experimental setup. The movie was numerically recorded and replayed from three sets of digital holograms obtained with three different laser lines (476 nm, 532 nm, and 647 nm). The movie shows convective flows induced by thermal dissipation in a tank filled
Potential and limits of holographic reconstruction algorithms
M. Berger; D. Briick; M. Fischer; K. J. Langenberg; J. Oberst; V. Schmitz
1981-01-01
For the purpose of ultrasonic nondestructive testing of materials, holography in connection with digital reconstruction algorithms has been proposed as a modern tool to extract crack sizes from ultrasonic scattering data. Defining the typical holographic reconstruction algorithm as the application of the scalar Kirchhoff diffraction theory to backward wave propagation, we demonstrate its general incapability of reconstructing equivalent sources, and
Gravitation from entanglement in holographic CFTs
NASA Astrophysics Data System (ADS)
Faulkner, Thomas; Guica, Monica; Hartman, Thomas; Myers, Robert C.; Van Raamsdonk, Mark
2014-03-01
Entanglement entropy obeys a `first law', an exact quantum generalization of the ordinary first law of thermodynamics. In any CFT with a semiclassical holographic dual, this first law has an interpretation in the dual gravitational theory as a constraint on the spacetimes dual to CFT states. For small perturbations around the CFT vacuum state, we show that the set of such constraints for all ball-shaped spatial regions in the CFT is exactly equivalent to the requirement that the dual geometry satisfy the gravitational equations of motion, linearized about pure AdS. For theories with entanglement entropy computed by the Ryu-Takayanagi formula S = /(4 G N), we obtain the linearized Einstein equations. For theories in which the vacuum entanglement entropy for a ball is computed by more general Wald functionals, we obtain the linearized equations for the associated higher-curvature theories. Using the first law, we also derive the holographic dictionary for the stress tensor, given the holographic formula for entanglement entropy. This method provides a simple alternative to holographic renormalization for computing the stress tensor expectation value in arbitrary higher derivative gravitational theories.
Two-frequency microwave holographic interferometry
G. Papi; V. Russo; S. Sottini
1972-01-01
Some experimental results on two-frequency microwave holographic interferometry are reported. This technique, well known in optics, has been extended to microwaves associated with the optical reconstruction of the interference pattern. Two different procedures were used to perform the superposition of the two microwave holograms on the same plate. Possible applications are suggested.
Multipass holographic interferometer improves image resolution
NASA Technical Reports Server (NTRS)
Brooks, R. E.; Heflinger, L. O.
1970-01-01
Multipass holographic interferometer forms a hologram of high diffraction efficiency, and hence provides a bright and high contrast interferogram. It is used to study any effect which changes the index of refraction and to study surface deformations of a flat reflecting surface.
Holographic flow visualization in rotating turbomachinery
NASA Astrophysics Data System (ADS)
Parker, R. J.; Reeves, M.
1990-11-01
Holographic flow visualization has found many applications in rotating turbomachinery. Applications in the design of aeroengine fans, automotive turbochargers, turbines, helicopter rotors, and advanced propfans are discussed. Work in ducted rotating flows and rotating free aerofoils is brought together and new developments in each field are revealed.
The Holographic Brain: Implications for Training Design.
ERIC Educational Resources Information Center
Jones, James R.
Without special training, most people predominantly process data in one of four ways. Few achieve a coveted whole brain state that integrates such important but separate brain functions as logic and intuition. With new training techniques that exploit the holographic properties of the brain, organizations may be able to tap powerful whole brain…
Slow light based on holographic gratings
Guoquan Zhang
2011-01-01
We have reviewed recent progresses on slow light based on holographic gratings such as stationary gratings, nonlinearly induced dynamic gratings and atomic coherence gratings. Several applications such as addressable multi-channel all-optical buffer memory and stored phase conjugate light wave based on slow light and stopped light pulses will be addressed. I. INTRODUCTION Slow light has been studied intensively in the
Meson wave function from holographic models
Vega, Alfredo; Schmidt, Ivan [Departamento de Fisica y Centro de Estudios Subatomicos, Universidad Tecnica Federico Santa Maria, Casilla 110-V, Valparaiso (Chile); Branz, Tanja; Gutsche, Thomas; Lyubovitskij, Valery E. [Institut fuer Theoretische Physik, Universitaet Tuebingen, Kepler Center for Astro and Particle Physics, Auf der Morgenstelle 14, D-72076 Tuebingen (Germany)
2009-09-01
We consider the light-front wave function for the valence quark state of mesons using the AdS/CFT correspondence, as has been suggested by Brodsky and Teramond. Two kinds of wave functions, obtained in different holographic Soft-Wall models, are discussed.
Pattern recognition with magnonic holographic memory device
NASA Astrophysics Data System (ADS)
Kozhevnikov, A.; Gertz, F.; Dudko, G.; Filimonov, Y.; Khitun, A.
2015-04-01
In this work, we present experimental data demonstrating the possibility of using magnonic holographic devices for pattern recognition. The prototype eight-terminal device consists of a magnetic matrix with micro-antennas placed on the periphery of the matrix to excite and detect spin waves. The principle of operation is based on the effect of spin wave interference, which is similar to the operation of optical holographic devices. Input information is encoded in the phases of the spin waves generated on the edges of the magnonic matrix, while the output corresponds to the amplitude of the inductive voltage produced by the interfering spin waves on the other side of the matrix. The level of the output voltage depends on the combination of the input phases as well as on the internal structure of the magnonic matrix. Experimental data collected for several magnonic matrixes show the unique output signatures in which maxima and minima correspond to specific input phase patterns. Potentially, magnonic holographic devices may provide a higher storage density compare to optical counterparts due to a shorter wavelength and compatibility with conventional electronic devices. The challenges and shortcoming of the magnonic holographic devices are also discussed.
Noncontact dimensional measurement system using holographic scanning
Stephen F. Sagan; Robert S. Rosso; David M. Rowe
1997-01-01
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
Holographic associative memory of biological systems
Peter P. Gariaev; Viktor I. Chudin; Gennady G. Komissarov; Andrey A. Berezin; Anatoly A. Vasiliev
1991-01-01
We consider some specific problems and phenomena of morphogenetic information storage, reproduction, and transfer including phantom leaf effect and field-induced morphogenetic translations between different taxonomic units. Several experimental results are presented and their explanation is given using a new approach to morphogenesis which combines some physical models of holographic associative memory and the mathematical formalism of Fermi- Pasta-Ulam recurrence for
Sensitive holographic detection of small aerodynamic perturbations
NASA Technical Reports Server (NTRS)
Heflinger, L. O.
1972-01-01
Phase modulations enhance the sensitivity of holographic techniques for detecting disturbances which are caused by variations in gas density of the order of 1/10 wavelength or less. In the readout, subject perturbations show up as brightenings on a dark background.
Emergent gauge fields in holographic superconductors
NASA Astrophysics Data System (ADS)
Domènech, Oriol; Montull, Marc; Pomarol, Alex; Salvio, Alberto; Silva, Pedro J.
2010-08-01
Holographic superconductors have been studied so far in the absence of dynamical electromagnetic fields, namely in the limit in which they coincide with holographic superfluids. It is possible, however, to introduce dynamical gauge fields if a Neumann-type boundary condition is imposed on the AdS-boundary. In 3 + 1 dimensions, the dual theory is a 2 + 1 dimensional CFT whose spectrum contains a massless gauge field, signaling the emergence of a gauge symmetry. We study the impact of a dynamical gauge field in vortex configurations where it is known to significantly affect the energetics and phase transitions. We calculate the critical magnetic fields H c1 and H c2, obtaining that holographic superconductors are of Type II ( H c1 < H c2). We extend the study to 4 + 1 dimensions where the gauge field does not appear as an emergent phenomenon, but can be introduced, by a proper renormalization, as an external dynamical field. We also compare our predictions with those arising from a Ginzburg-Landau theory and identify the generic properties of Abrikosov vortices in holographic models.
Digital heterodyne holographic interferometry of flow fields
Jeff Hartlove
1980-01-01
Flow medium inhomogeneities associated with the gain region of large scale laser systems can result in significant degradation of the outcoupled laser beam quality. To achieve beam quality goals, relative density fluctuations will have to be below 10-5. An optical technique called digital heterodyne holographic interferometer (HHI) is presented which measures the wavefront distortion of a visible probe beam by
Holographic thermalization in N=4 Super Yang-Mills theory at finite coupling
Stefan A. Stricker
2013-10-14
We investigate the behavior of energy momentum tensor correlators in holographic $\\mathcal{N}=4$ super Yang-Mills plasma, taking finite coupling corrections into account. In the thermal limit we determine the flow of quasinormal modes as a function of the 't Hooft coupling. Then we use a specific model of holographic thermalization to study the deviation of the spectral densities from their thermal limit in an out-of-equilibrium situation. The main focus lies on the thermalization pattern with which the plasma constituents approach their thermal distribution as the coupling constant decreases from the infinite coupling limit. All obtained results point towards the weakening of the usual top-down thermalization pattern.
Chemical Potential in the First Law for Holographic Entanglement Entropy
David Kastor; Sourya Ray; Jennie Traschen
2014-09-16
Entanglement entropy in conformal field theories is known to satisfy a first law. For spherical entangling surfaces, this has been shown to follow via the AdS/CFT correspondence and the holographic prescription for entanglement entropy from the bulk first law for Killing horizons. The bulk first law can be extended to include variations in the cosmological constant $\\Lambda$, which we established in earlier work. Here we show that this implies an extension of the boundary first law to include varying the number of degrees of freedom of the boundary CFT. The thermodynamic potential conjugate to $\\Lambda$ in the bulk is called the thermodynamic volume and has a simple geometric formula. In the boundary first law it plays the role of a chemical potential. For the bulk minimal surface $\\Sigma$ corresponding to a boundary sphere, the thermodynamic volume is found to be proportional to the area of $\\Sigma$, in agreement with the variation of the known result for entanglement entropy of spheres. The dependence of the CFT chemical potential on the entanglement entropy and number of degrees of freedom is similar to how the thermodynamic chemical potential of an ideal gas depends on entropy and particle number.
NASA Astrophysics Data System (ADS)
Schnekenburger, Juergen; Bredebusch, Ilona; Langehanenberg, Patrik; Domschke, Wolfram; von Bally, Gert; Kemper, Björn
2007-07-01
The actin cytoskeleton mediates a variety of crucial cellular functions as migration, intracellular transport, exocytosis, endocytosis and force generation. The highly dynamic actin fibers are therefore targets for several drugs and toxins. However the study of actin interfering processes by standard microscopy techniques fails in the detailed resolution of dynamic spatial alterations required for a deeper understanding of toxic effects. Here we applied digital holographic microscopy in the online functional analysis of the actin cytoskeleton disrupting marine toxin Latrunculin B. SEM and fluorescence microscopy showed rapid Latrunculin B induced alterations in cell morphology and actin fiber degradation in pancreas tumor cells. The dynamic digital holographic in vivo analysis of the drug dependent cellular processes demonstrated differences in the actin cytoskeleton stability of highly differentiated and dedifferentiated pancreas tumor cell lines. The spatial resolution of the morphological alterations revealed unequal changes in cell morphology. While cells with a low metastatic potential showed Latrunculin B induced cell collapse within 4 h the metastatic tumor cells were increased in cell volume indicating Latrunculin B effects also on cell water content. These data demonstrate that marker free, non-destructive online analysis of cellular morphology and dynamic spatial processes in living cells by digital holography offers new insights in actin dependent cellular mechanisms. Digital holographic microscopy was shown to be a versatile tool in the screening of toxic drug effects and cancer cell biology.
Naturalness of the Vacuum Energy in Holographic Theories
Csaba Balazs; Istvan Szapudi
2006-03-17
Based on the cosmic holographic conjecture of Fischler and Susskind, we point out that the average energy density of the universe is bound from above by its entropy limit. Since Friedmann's equation saturates this relation, the measured value of the cosmological energy density is completely natural in the framework of holographic thermodynamics: vacuum energy density fills the available quantum degrees of freedom allowed by the holographic bound. This is in strong contrast with traditional quantum field theories where, since no similar bound applies, the natural value of the vacuum energy is expected to be 123 orders of magnitude higher than the holographic value. Based on our simple calculation, holographic thermodynamics, and consequently any future holographic quantum (gravity) theory, resolves the vacuum energy puzzle.
Two-dimensional holographic deflection and scanning system
C. C. K. Cheng; B. J. Chang
1977-01-01
The feasibility of holographic scanners as universal product code label readers is demonstrated by fabrication of several multihologram disk scanners which generate suitable lattice scan patterns. Holographic scanners can be used to replace some polygons, mirrors, and lenses, which are high-cost components of mechanical scanners currently used in supermarket point-of-sale scanner systems. The theoretical principles and construction of the holographic
Short-coherence off-axis holographic phase microscopy of live cell dynamics
Witte, Stefan; Plau?ka, Andrius; Ridder, Margreet C.; van Berge, Laura; Mansvelder, Huibert D.; Groot, Marie Louise
2012-01-01
We demonstrate a single-shot holographic phase microscope that combines short-coherence laser pulses with an off-axis geometry. By introducing a controlled pulse front tilt, ultrashort pulses are made to interfere over a large field-of-view without loss of fringe contrast. With this microscope, quantitative phase images of live cells can be recorded in a full-field geometry without moving parts. We perform phase imaging of HEK293 cells, to study the dynamics of cell volume regulation in response to an osmotic shock. PMID:23024912
Photosensitive holographic material with a medium of fluorescent ink
NASA Astrophysics Data System (ADS)
Olivares-Pérez, A.; Toxqui-López, S.; Fuentes-Tapia, I.; Ortiz-Gutiérrez, M.; Mellado-Villaseñor, G.
2012-03-01
Recent researches have been reported that is possible increase the diffraction efficiency parameter from holographic gratings when photosensitive material (PVA with ammonium dichromate) it is painted after register the hologram with commercial fluorescent ink. In this research we shown that PVA as a binder, with the fluorescent ink and ammonium dichromate, this mixed can be used as recording medium. We characterize this material by implementing holographic films in which holographic gratings are recorded with a He- Cd laser at 442nm, and measuring holographic parameters such as diffraction efficiency. We get increased the diffraction efficiency and also the lifetime of the film.
Holographic dual of a boundary conformal field theory.
Takayanagi, Tadashi
2011-09-01
We propose a holographic dual of a conformal field theory defined on a manifold with boundaries, i.e., boundary conformal field theory (BCFT). Our new holography, which may be called anti-de Sitter BCFT, successfully calculates the boundary entropy or g function in two-dimensional BCFTs and it agrees with the finite part of the holographic entanglement entropy. Moreover, we can naturally derive a holographic g theorem. We also analyze the holographic dual of an interval at finite temperature and show that there is a first order phase transition. PMID:21981491
NASA Astrophysics Data System (ADS)
Chen, Yu-Fang; Hsiao, Yi-Nan; Lin, Shiuan Huei; Hsu, Ken Y.; Cheng, Wei-Sheng; Whang, Wha-Tzong
2009-12-01
In this research, we fabricate and characterize lanthanide organometallic compounds and 9,10-phenanthrenequinone (PQ) co-doped poly(2-hydroxyethyl methacrylate-co-methyl methacrylate) photopolymers for holographic recording. Five different lanthanoid (Ce3+, Nd3+, Er3+, Yb3+ and Lu3+) organometallic compounds, one at a time, is co-doped with PQ in a poly(HEMA-co-MMA) matrix, respectively. Holographic experiments demonstrate that lutetium organometallic compounds and a PQ co-doped poly(HEMA-co-MMA) photopolymer can greatly enhance the volume holographic characteristics. The degree of improvement in hologram diffraction efficiency and the recording dynamic range for these co-doped photopolymers follows the order: Lu3+>Yb3+>Er3+>Nd3+>Ce3+.
Cold holographic matter in the Higgs branch
Itsios, Georgios; Ramallo, Alfonso V
2015-01-01
We study collective excitations of cold (2+1)-dimensional fundamental matter living on a defect of the four-dimensional N=4 super Yang-Mills theory in the Higgs branch. This system is realized holographically as a D3-D5 brane intersection, in which the D5-brane is treated as a probe with a non-zero gauge flux across the internal part of its worldvolume. We study the holographic zero sound mode in the collisionless regime at low temperature and find a simple analytic result for its dispersion relation. We also find the diffusion constant of the system in the hydrodynamic regime at higher temperature. In both cases we study the dependence on the flux parameter which determines the amount of Higgs symmetry breaking. We also discuss the anyonization of this construction.
Holographic Hall conductivities from dyonic backgrounds
Lindgren, Jonathan; Taliotis, Anastasios; Vanhoof, Joris
2015-01-01
We develop a general framework for computing the holographic 2-point functions and the corresponding conductivities in asymptotically locally AdS backgrounds with an electric charge density, a constant magentic field, and possibly non-trivial scalar profiles, for a broad class of Einstein-Maxwell-Axion-Dilaton theories, including certain Chern-Simons terms. Holographic renormalization is carried out for any theory in this class and the computation of the renormalized AC conductivities at zero spatial momentum is reduced to solving a single decoupled first order Riccati equation. Moreover, we develop a first order fake supergravity formulalism for dyonic renormalization group flows in four dimensions, allowing us to construct analytically infinite families of such backgrounds by specifying a superpotential at will. These RG flows interpolate between AdS$_4$ in the UV and a hyperscaling violating Lifshitz geometry in the IR with exponents $1
Holographic entanglement entropy in the nonconformal medium
NASA Astrophysics Data System (ADS)
Park, Chanyong
2015-06-01
We investigate holographically the entanglement entropy of a nonconformal medium whose dual geometry is described by an Einstein-Maxwell-dilaton theory. Because of an additional conserved charge corresponding to the number operator, its thermodynamics can be represented in a grand canonical or canonical ensemble. We study thermodynamics in both ensembles by using the holographic renormalization and the entanglement entropy of a nonconformal medium. After defining the entanglement chemical potential, which unlike the entanglement temperature has a nontrivial size dependence, we find that the entanglement entropy of a small subsystem satisfies the relation resembling the first law of thermodynamics in a medium. Furthermore, we study the entanglement entropy change in the nonconformal medium caused by the excitation of the ground state and by the global quench corresponding to the insertion of particles.
Capability enhancement in compact digital holographic microscopy
NASA Astrophysics Data System (ADS)
Qu, Weijuan; Wen, Yongfu; Wang, Zhaomin; Yang, Fang; Asundi, Anand
2015-03-01
A compact reflection digital holographic microscopy (DHM) system integrated with the light source and optical interferometer is developed for 3D topographic characterization and real-time dynamic inspection for Microelectromechanical systems (MEMS). Capability enhancement methods in lateral resolution, axial resolving range and large field of view for the compact DHM system are presented. To enhance the lateral resolution, the numerical aperture of a reflection DHM system is analyzed and optimum designed. To enhance the axial resolving range, dual wavelengths are used to extend the measuring range. To enable the large field of view, stitching of the measurement results is developed in the user-friendly software. Results from surfaces structures on silicon wafer, micro-optics on fused silica and dynamic inspection of MEMS structures demonstrate applications of this compact reflection digital holographic microscope for technical inspection in material science.
Holographic Optical Storage Using Photorefractive Polymers
NASA Technical Reports Server (NTRS)
Hayden, L. Michael; Strutz, Shane J.; Harris, Kristi; Ayachitula, Rajani
2000-01-01
The task for this report is to perform the basic research and develop a prototype benchtop holographic optical storage system based on photochromic and/or photorefractive polymers so that both permanent and erasable images may be stored and retrieved in the same mixed polymer medium. The task consist of: assembly and setup of the benchtop holographic storage system, including lasers, optics, and other ancillary equipment in a laboratory setting; and research and development of a suitable polymer matrix that will allow practical storage and retrieval of digital data. This will necessitate molecular design of the matrices involved and subsequent physics test to verify the characteristics of the matrices provide practical storage and retrieval.
Measurements of Holographic Properties of Bacteriorhodopsin Films
NASA Technical Reports Server (NTRS)
Downie, John D.; Swietek, Gregory E. (Technical Monitor)
1995-01-01
Several different bacteriorhodopsin (BR) films are characterized with respect to general holographic properties. Experimental measurements include diffraction efficiency and sensitivity as functions of writing intensity and grating frequency, hologram thermal decay behavior, diffraction efficiency as a function of grating tilt within the film and modulation depth, and estimates of the refractive index change from the diffraction efficiency data. The films studied include those made from wildtype BR and the genetic variants D96N and D96N/T46V. The maximum diffraction efficiency measured was just over 3% for a hydrated wildtype BR film. The films' holographic properties were found to be relatively insensitive to grating frequency and grating tilt angle. The diffraction efficiency dropped off more sharply as a function of modulation depth than a purely linear medium, and only the hydrated wildtype film exhibited significant behavior variation with different writing intensities.