WorldWideScience

Sample records for energy-based ghost force

  1. Derivation of energy-based base shear force coefficient considering hysteretic behavior and P-delta effects

    Science.gov (United States)

    Ucar, Taner; Merter, Onur

    2018-01-01

    A modified energy-balance equation accounting for P-delta effects and hysteretic behavior of reinforced concrete members is derived. Reduced hysteretic properties of structural components due to combined stiffness and strength degradation and pinching effects, and hysteretic damping are taken into account in a simple manner by utilizing plastic energy and seismic input energy modification factors. Having a pre-selected yield mechanism, energy balance of structure in inelastic range is considered. P-delta effects are included in derived equation by adding the external work of gravity loads to the work of equivalent inertia forces and equating the total external work to the modified plastic energy. Earthquake energy input to multi degree of freedom (MDOF) system is approximated by using the modal energy-decomposition. Energy-based base shear coefficients are verified by means of both pushover analysis and nonlinear time history (NLTH) analysis of several RC frames having different number of stories. NLTH analyses of frames are performed by using the time histories of ten scaled ground motions compatible with elastic design acceleration spectrum and fulfilling duration/amplitude related requirements of Turkish Seismic Design Code. The observed correlation between energy-based base shear force coefficients and the average base shear force coefficients of NLTH analyses provides a reasonable confidence in estimation of nonlinear base shear force capacity of frames by using the derived equation.

  2. Ghostly footsteps

    DEFF Research Database (Denmark)

    Pinder, David

    2001-01-01

    ), which is set in east London. Connections are also drawn with other recent projects in the same area by Rachel Lichtenstein and Iain Sinclair. The paper discusses how these artists raise important issues about the cultural geographies of the city relating to subjectivity, representation and memory....... Cardiff’s audio-walk in particular works with connections between the self and the city, between the conscious and unconscious, and between multiple selves and urban footsteps. In so doing, she directs attention to the significance of dreams and ghostly matters for thinking about the real and imagined...

  3. Energy-based Lyapunov functions for forced Hamiltonian systems with dissipation

    NARCIS (Netherlands)

    Maschke, Bernhard M.J.; Ortega, Romeo; Schaft, Arjan J. van der

    1998-01-01

    It is well known that the total energy is a suitable Lyapunov function to study the stability of the trivial equilibrium of an isolated standard Hamiltonian system. In many practical instances, however, the system is in interaction with its environment through some constant forcing terms. This gives

  4. The ghost propagator in Coulomb gauge

    International Nuclear Information System (INIS)

    Watson, P.; Reinhardt, H.

    2011-01-01

    We present results for a numerical study of the ghost propagator in Coulomb gauge whereby lattice results for the spatial gluon propagator are used as input to solving the ghost Dyson-Schwinger equation. We show that in order to solve completely, the ghost equation must be supplemented by a boundary condition (the value of the inverse ghost propagator dressing function at zero momentum) which determines if the solution is critical (zero value for the boundary condition) or subcritical (finite value). The various solutions exhibit a characteristic behavior where all curves follow the same (critical) solution when going from high to low momenta until 'forced' to freeze out in the infrared to the value of the boundary condition. The boundary condition can be interpreted in terms of the Gribov gauge-fixing ambiguity; we also demonstrate that this is not connected to the renormalization. Further, the connection to the temporal gluon propagator and the infrared slavery picture of confinement is discussed.

  5. Ghost story. II. The midpoint ghost vertex

    International Nuclear Information System (INIS)

    Bonora, L; Maccaferri, C; Scherer Santos, R.J.; Tolla, D D

    2009-01-01

    We construct the ghost number 9 three strings vertex for OSFT in the natural normal ordering. We find two versions, one with a ghost insertion at z = i and a twist-conjugate one with insertion at z = -i. For this reason we call them midpoint vertices. We show that the relevant Neumann matrices commute among themselves and with the matrix G representing the operator K 1 . We analyze the spectrum of the latter and find that beside a continuous spectrum there is a (so far ignored) discrete one. We are able to write spectral formulas for all the Neumann matrices involved and clarify the important role of the integration contour over the continuous spectrum. We then pass to examine the (ghost) wedge states. We compute the discrete and continuous eigenvalues of the corresponding Neumann matrices and show that they satisfy the appropriate recursion relations. Using these results we show that the formulas for our vertices correctly define the star product in that, starting from the data of two ghost number 0 wedge states, they allow us to reconstruct a ghost number 3 state which is the expected wedge state with the ghost insertion at the midpoint, according to the star recursion relation.

  6. Ghost cell lesions

    Directory of Open Access Journals (Sweden)

    E Rajesh

    2015-01-01

    Full Text Available Ghost cells have been a controversy for a long time. Ghost cell is a swollen/enlarged epithelial cell with eosnophilic cytoplasm, but without a nucleus. In routine H and E staining these cells give a shadowy appearance. Hence these cells are also called as shadow cells or translucent cells. The appearance of these cells varies from lesion to lesion involving odontogenic and nonodontogenic lesions. This article review about the origin, nature and significance of ghost cells in different neoplasms.

  7. Classical and quantum ghosts

    International Nuclear Information System (INIS)

    Sbisà, Fulvio

    2015-01-01

    The aim of these notes is to provide a self-contained review of why it is generically a problem when a solution of a theory possesses ghost fields among the perturbation modes. We define what a ghost field is and we show that its presence is associated with a classical instability whenever the ghost field interacts with standard fields. We then show that the instability is more severe at quantum level, and that perturbative ghosts can exist only in low energy effective theories. However, if we do not consider very ad hoc choices, compatibility with observational constraints implies that low energy effective ghosts can exist only at the price of giving up Lorentz invariance or locality above the cut-off, in which case the cut-off has to be much lower that the energy scales we currently probe in particle colliders. We also comment on the possible role of extra degrees of freedom which break Lorentz invariance spontaneously. (paper)

  8. Ghost D-branes

    International Nuclear Information System (INIS)

    Okuda, Takuya; Takayanagi, Tadashi

    2006-01-01

    We define a ghost D-brane in superstring theories as an object that cancels the effects of an ordinary D-brane. The supergroups U(N|M) and OSp(N/M) arise as gauge symmetries in the supersymmetric world-volume theory of D-branes and ghost D-branes. A system with a pair of D-brane and ghost D-brane located at the same location is physically equivalent to the closed string vacuum. When they are separated, the system becomes a new brane configuration. We generalize the type I/heterotic duality by including n ghost D9-branes on the type I side and by considering the heterotic string whose gauge group is OSp(32+2n/2n). Motivated by the type IIB S-duality applied to D9- and ghost D9-branes, we also find type II-like closed superstrings with U(n/n) gauge symmetry

  9. Ghost counting in supergravity

    International Nuclear Information System (INIS)

    Nielsen, N.K.

    1978-04-01

    The elimination of unphysical degrees of freedom from a quantized massless Rarita-Schwinger field interacting with a (quantized or classical) gravitational field is analyzed on the one-loop level. It is shown that, besides the ordinary Faddeev-Popov ghosts, an extra ghost is needed to remove the effects of unphysical modes. The new ghost only couples to the S matrix if the gauge-fixing of the Rarita-Schwinger field involves the gravitational field, but it is necessary in the partition function for other gauge choices. (Auth.)

  10. Ghost counting in supergravity

    International Nuclear Information System (INIS)

    Nielsen, N.K.

    1978-01-01

    The elimination of unphysical degrees of freedom from a quantized massless Rarita-Schwinger field interacting with a (quantized or classical) gravitational field is analyzed on the one-loop level. It is shown that, besides the ordinary Faddeev-Popov ghosts, an extra ghost is needed to remove the effects of unphysical modes. The new ghost only couples to the S-matrix if the gauge-fixing of the Rarita-Schwinger field involves the gravitational field, but it is necessary in the partition function for other gauge choices. (Auth.)

  11. The Ghostly Workings of Danish Accountability Policies

    Science.gov (United States)

    Pors, Justine Grønbaek

    2016-01-01

    This article proposes a framework for thinking about the ghostly, thus arguing that policy can be understood as a landscape of intersecting and colliding temporalities from which arouse curious workings of barely-there forces, spooky energies and vibrating saturations of affective ambivalences. I present an empirical study of a policy agenda of…

  12. Ghost basis for neutrino

    International Nuclear Information System (INIS)

    Novello, M.

    1976-07-01

    A class of solutions of DIRAC'S equation in gravitational fields for ghost neutrinos is given. Comments are restricted to the neutrino cosmological model recently found by M. Novello e I.D. Soares [pt

  13. New Mexico Ghost Towns

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This data provides locations and non-spatial attributes of many ghost towns in the State of New Mexico, compiled from various sources. Locations provided with...

  14. Geometric ghosts and unitarity

    International Nuclear Information System (INIS)

    Ne'eman, Y.

    1980-09-01

    A review is given of the geometrical identification of the renormalization ghosts and the resulting derivation of Unitarity equations (BRST) for various gauges: Yang-Mills, Kalb-Ramond, and Soft-Group-Manifold

  15. Ghost telescope and ghost Fourier telescope with thermal light

    International Nuclear Information System (INIS)

    Gong Wenlin; Han Shensheng

    2011-01-01

    As important observation tools, telescopes are very useful in remote observations. We report a proof-of-principle experimental demonstration of ghost telescope scheme and show that, by measuring the intensity correlation of two light fields and only changing the position of the detector in the reference path, ghost telescope and ghost Fourier telescope can be obtained even if a single-pixel detector is fixed in Fresnel region of the object. Differences between conventional telescope and ghost telescope are also discussed.

  16. On ghost fermions

    International Nuclear Information System (INIS)

    Grensing, G.

    2002-01-01

    The path integral for ghost fermions, which is heuristically made use of in the Batalin-Fradkin-Vilkovisky approach to quantization of constrained systems, is derived from first principles. The derivation turns out to be rather different from that of physical fermions since the definition of Dirac states for ghost fermions is subtle. With these results at hand, it is then shown that the nonminimal extension of the Becchi-Rouet-Stora-Tyutin operator must be chosen differently from the notorious choice made in the literature in order to avoid the boundary terms that have always plagued earlier treatments. Furthermore it is pointed out that the elimination of states with nonzero ghost number requires the introduction of a thermodynamic potential for ghosts; the reason is that Schwarz's Lefschetz formula for the partition function of the time-evolution operator is not capable, despite claims to the contrary, to get rid of nonzero ghost number states on its own. Finally, we comment on the problems of global topological nature that one faces in the attempt to obtain the solutions of the Dirac condition for physical states in a configuration space of nontrivial geometry; such complications give rise to anomalies that do not obey the Wess-Zumino consistency conditions. (orig.)

  17. GHOST balloons around Antarctica

    Science.gov (United States)

    Stearns, Charles R.

    1988-01-01

    The GHOST balloon position as a function of time data shows that the atmospheric circulation around the Antarctic Continent at the 100 mb and 200 mb levels is complex. The GHOST balloons supposedly follow the horizontal trajectory of the air at the balloon level. The position of GHOST balloon 98Q for a three month period in 1968 is shown. The balloon moved to within 2 deg of the South Pole on 1 October 1968 and then by 9 December 1968 was 35 deg from the South Pole and close to its position on 1 September 1968. The balloon generally moved from west to east but on two occasions moved in the opposite direction for a few days. The latitude of GHOST balloons 98Q and 149Z which was at 200 mb is given. Both balloons tended to get closer to the South Pole in September and October. Other GHOST balloons at the same pressure and time period may not indicate similar behavior.

  18. Ghost tablet in feces.

    Science.gov (United States)

    Iwamuro, Masaya; Morishita, Yosuke; Urata, Haruo; Okada, Hiroyuki

    2017-12-01

    Recently, we encountered a female patient who identified the presence of a ghost tablet in her fecal matter. Interestingly, although the patient was prescribed potassium chloride capsules, elemental composition analysis by energy-dispersive X-ray spectroscopy was unable to detect the presence of either potassium or chloride in the fecal tablet remnant.

  19. Giving up the ghost

    International Nuclear Information System (INIS)

    Bender, Carl M; Mannheim, Philip D

    2008-01-01

    The Pais-Uhlenbeck model is a quantum theory described by a higher-derivative field equation. It has been believed for many years that this model possesses ghost states (quantum states of negative norm) and therefore that this model is a physically unacceptable quantum theory. The existence of such ghost states was believed to be attributable to the field equation having more than two derivatives. This paper shows that the Pais-Uhlenbeck model does not possess any ghost states at all and that it is a perfectly acceptable quantum theory. The supposed ghost states in this model arise if the Hamiltonian of the model is (incorrectly) treated as being Dirac Hermitian (invariant under combined matrix transposition and complex conjugation). However, the Hamiltonian is not Dirac Hermitian, but rather it is PT symmetric. When it is quantized correctly according to the rules of PT quantum mechanics, the energy spectrum is real and bounded below and all of the quantum states have positive norm

  20. Ghost imaging with atoms

    Science.gov (United States)

    Khakimov, R. I.; Henson, B. M.; Shin, D. K.; Hodgman, S. S.; Dall, R. G.; Baldwin, K. G. H.; Truscott, A. G.

    2016-12-01

    Ghost imaging is a counter-intuitive phenomenon—first realized in quantum optics—that enables the image of a two-dimensional object (mask) to be reconstructed using the spatio-temporal properties of a beam of particles with which it never interacts. Typically, two beams of correlated photons are used: one passes through the mask to a single-pixel (bucket) detector while the spatial profile of the other is measured by a high-resolution (multi-pixel) detector. The second beam never interacts with the mask. Neither detector can reconstruct the mask independently, but temporal cross-correlation between the two beams can be used to recover a ‘ghost’ image. Here we report the realization of ghost imaging using massive particles instead of photons. In our experiment, the two beams are formed by correlated pairs of ultracold, metastable helium atoms, which originate from s-wave scattering of two colliding Bose-Einstein condensates. We use higher-order Kapitza-Dirac scattering to generate a large number of correlated atom pairs, enabling the creation of a clear ghost image with submillimetre resolution. Future extensions of our technique could lead to the realization of ghost interference, and enable tests of Einstein-Podolsky-Rosen entanglement and Bell’s inequalities with atoms.

  1. Getting started with Ghost

    CERN Document Server

    Bracey, Kezz; Balderston, David

    2014-01-01

    If you are new to Ghost, this book is ideal for you. You might be completely new to content management systems or you might have experience with others such as WordPress. Some knowledge of web design basics such as HTML and CSS will be useful, but the book is designed so you can enter at the point relevant to you.

  2. Ghost Stories, Ghost Estates: Melancholia in Irish Recession Literature

    Directory of Open Access Journals (Sweden)

    Molly Slavin

    2017-01-01

    Full Text Available This article considers representations of melancholia in post-Celtic Tiger Irish literature. By situating their post-recession fictions in “ghost estates,” or largely uninhabited housing developments, Donal Ryan and Tana French present neoliberally-inflected varieties of melancholia for their contemporary readers to contemplate. The settings of the ghost estates – and the accompanying supernatural elements to the texts – call to mind ghosts of Ireland’s past and legacies of recent economically unsound policies, spurring the reader to think about the imagined loss of futurity that accompanied the Irish economic crash. “Ghost stories for ghost estates,” then, represent an important contribution to the growing field of post-recession Irish literature.

  3. Ghost quintessence in fractal gravity

    Indian Academy of Sciences (India)

    In this study, using the time-like fractal theory of gravity, we mainly focus on the ghost dark energy model which was recently suggested to explain the present acceleration of the cosmic expansion. Next, we establish a connection between the quintessence scalar field and fractal ghost dark energy density.

  4. Magnetic ghosts and monopoles

    International Nuclear Information System (INIS)

    Vandewalle, N; Dorbolo, S

    2014-01-01

    While the physics of equilibrium systems composed of many particles is well known, the interplay between small-scale physics and global properties is still a mystery for athermal systems. Non-trivial patterns and metastable states are often reached in those systems. We explored the various arrangements adopted by magnetic beads along chains and rings. Here, we show that it is possible to create mechanically stable defects in dipole arrangements keeping the memory of dipole frustration. Such defects, nicknamed ‘ghost junctions’, seem to act as macroscopic magnetic monopoles, in a way reminiscent of spin ice systems. (paper)

  5. Ghost-Story Telling: Keeping It Appropriate.

    Science.gov (United States)

    Weintraub, Jeff

    1996-01-01

    Guidelines for telling ghost stories at camp involve considering children's fears at different ages, telling age appropriate stories, determining appropriate times for telling ghost stories, and minimizing fear when a child becomes frightened by a ghost story. Includes tips on the selection, preparation, and presentation of ghost stories. (LP)

  6. Living with ghosts

    International Nuclear Information System (INIS)

    Hawking, S.W.; Hertog, Thomas

    2002-01-01

    Perturbation theory for gravity in dimensions greater than two requires higher derivatives in the free action. Higher derivatives seem to lead to ghosts, states with negative norm. We consider a fourth order scalar field theory and show that the problem with ghosts arises because, in the canonical treatment, φ and □φ are regarded as two independent variables. Instead, we base quantum theory on a path integral, evaluated in Euclidean space and then Wick rotated to Lorentzian space. The path integral requires that quantum states be specified by the values of φ and φ ,τ . To calculate probabilities for observations, one has to trace out over φ ,τ on the final surface. Hence one loses unitarity, but one can never produce a negative norm state or get a negative probability. It is shown that transition probabilities tend toward those of the second order theory, as the coefficient of the fourth order term in the action tends to zero. Hence unitarity is restored at the low energies that now occur in the universe

  7. Cosmology with a light ghost

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, Mikhail M.; Tokareva, Anna A., E-mail: mikhail.ivanov@cern.ch, E-mail: anna.tokareva@epfl.ch [Institute of Physics, LPPC, École Polytechnique Fédérale de Lausanne, CH-1015, Lausanne (Switzerland)

    2016-12-01

    We study the creation and evolution of cosmological perturbations in renormalizable quadratic gravity with a Weyl term. We adopt a prescription that implies the stability of the vacuum at the price of introducing a massive spin-two ghost state, leading to the loss of unitarity. The theory may still be predictive regardless the interpretation of non-unitary processes provided that their rate is negligible compared to the Universe expansion rate. This implies that the ghost is effectively stable. In such a setup, there are two scalar degrees of freedom excited during inflation. The first one is the usual curvature perturbation whose power spectrum appears to coincide with that of single-field inflation. The second one is a scalar component of the ghost encoded in the shift vector of the metric in the uniform inflaton gauge. The amplitudes of primordial tensor and vector perturbations are strongly suppressed. After inflation the ghost field starts to oscillate and its energy density shortly becomes dominant in the Universe. For all ghost masses allowed by laboratory constraints ghosts should have ''overclosed'' the Universe at temperatures higher than that of primordial nucleosynthesis. Thus, the model with the light Weyl ghost is ruled out.

  8. Inflation with light Weyl ghost

    Directory of Open Access Journals (Sweden)

    Tokareva Anna

    2016-01-01

    Full Text Available Inflationary perturbations are considered in a renormalizable but non-unitary theory of gravity with the additional Weyl term. We obtained that ghost degrees of freedom do not spoil the inflation and the scalar perturbation amplitude at the linear level even in a case of the ghost with mass smaller than Hubble parameter at inflation. The ghost impact to the observables is also estimated to be negligible for the range of masses allowed by the experiment. The non-linear level of the theory and its possible application are also discussed.

  9. Ghost Imaging of Space Objects

    Data.gov (United States)

    National Aeronautics and Space Administration — Ghost imaging is an optical imaging technique that utilizes the correlations between optical fields in two channels. One of the channels contains the object, however...

  10. Witten's ghost vertex made simple

    International Nuclear Information System (INIS)

    Belov, D.M.

    2004-01-01

    First, we diagonalize the bc-ghost 3-string Neumann matrices using the technique described in Phys. Rev. D 68, 066003 (2003). Their eigenvalues are in complete agreement with the previous authors. Second, we diagonalize the N-string gluing vertices for the bosonized ghost system. Third, we verify the descent and associativity relations for the combined bosonic matter+ghost gluing vertices. We find that in order for these relations to be true, the vertices must be normalized by the factor Z N . Here Z N is the partition function of the bosonic matter+ghost CFT on the gluing surface, which is the unit disk with the Neumann boundary conditions and the midpoint conelike singularity specified by the angle excess π(N-2)

  11. Ghost Head Nebula

    Science.gov (United States)

    1999-01-01

    Looking like a colorful holiday card, a new image from NASA's Hubble Space Telescope reveals a vibrant green and red nebula far from Earth. The image of NGC 2080, taken by Hubble's Wide Field and Planetary Camera 2, designed and built by NASA's Jet Propulsion Laboratory, Pasadena, Calif., is available online at http://www.jpl.nasa.gov/images/wfpc . Images like this help astronomers investigate star formation in nebulas. NGC 2080, nicknamed 'The Ghost Head Nebula,' is one of a chain of star-forming regions lying south of the 30 Doradus nebula in the Large Magellanic Cloud. 30 Doradus is the largest star-forming complex in the local group of galaxies. This 'enhanced color' picture is composed of three narrow-band-filter images obtained by Hubble on March 28, 2000. The red and blue light come from regions of hydrogen gas heated by nearby stars. The green light on the left comes from glowing oxygen. The energy to illuminate the green light is supplied by a powerful stellar wind, a stream of high-speed particles coming from a massive star just outside the image. The central white region is a combination of all three emissions and indicates a core of hot, massive stars in this star-formation region. Intense emission from these stars has carved a bowl-shaped cavity in surrounding gas. In the white region, the two bright areas (the 'eyes of the ghost') - named A1 (left) and A2 (right) -- are very hot, glowing 'blobs' of hydrogen and oxygen. The bubble in A1 is produced by the hot, intense radiation and powerful stellar wind from one massive star. A2 contains more dust and several hidden, massive stars. The massive stars in A1 and A2 must have formed within the last 10,000 years, since their natal gas shrouds are not yet disrupted by the powerful radiation of the newborn stars. The Space Telescope Science Institute is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract with the Goddard Space Flight Center, Greenbelt, Md. The

  12. Using Ghost Reflections Rather than Removing Them

    NARCIS (Netherlands)

    Blacquiere, G.; Berkhout, A.J.

    2015-01-01

    In marine acquisition both a direct wavefield and a ghost wavefield are produced as well as recorded. Hence, the seismic data can be considered to be a natural blend of four wavefields related to the real sources, ghost sources, real detectors and ghost detectors respectively. We consider deghosting

  13. Confessions of Academic Ghost Authors

    Directory of Open Access Journals (Sweden)

    Ehsan Shahghasemi

    2015-02-01

    Full Text Available Academic plagiarism exists in all academic spheres, but contextual factors determine the level, intensity, and forms of it. Over the last few years, the phenomenon of “Ghost Authorship” has become widespread in Iran, and concerns have been expressed regarding this issue, not only by academicians but also by officials. In this study, 143 students participated in a two-step interview study in which they spoke about their experiences on either seeing a ghost author doing the research of someone else in exchange of money or they themselves being a ghost author. In all, 29 students said that they had done it once or so. The in-depth interviews with these 29 students showed how the plagiarism industry works in Iran, who the customers are, how they find each other, and so on.

  14. Ghost condensate and generalized second law

    International Nuclear Information System (INIS)

    Mukohyama, Shinji

    2009-01-01

    Dubovsky and Sibiryakov recently proposed a scenario in which particles of different species propagate with different speeds due to their direct couplings to ghost condensate. It was argued that this extended version of ghost condensate allows a gedanken experiment leading to violation of the generalized second law. However, in the original ghost condensate scenario, difference in propagation speeds is suppressed by M 2 /M Pl 2 , where M is the order parameter of spontaneous Lorentz breaking and M Pl is the Planck scale. In this case the energy transfer necessary for the gedanken experiment is so slow that the timescale of decrease of entropy, if any, is always longer than the Jeans timescale of ghost condensate. Hence the generalized second law is not violated by the gedanken experiment in the original ghost condensate scenario. This conclusion trivially extends to gauged ghost condensation by taking into account accretion of gauged ghost condensate into a black hole.

  15. Unexorcized ghost in DGP brane world

    International Nuclear Information System (INIS)

    Izum, Keisuke; Tanaka, Takahiro; Koyama, Kazuya

    2007-01-01

    The brane world model proposed by Dvali-Gabadadze-Porrati realizes self-acceleration of the universe. However, it is known that this cosmological solution contains a spin-2 ghost. We study the possibility of avoiding the appearance of the ghost by slightly modifying the model via the introduction of a second brane. First, we consider a simple model without stabilization of the brane separation. By changing the separation between the branes, we find that we can erase the spin-2 ghost. However, this can be done only at the expense of the appearance of a spin-0 ghost instead. We discuss why these two different types of ghosts are correlated. Then, we examine a model with stabilization of the brane separation. Even in this case, we find that the correlation between spin-0 and spin-2 ghosts remains. As a result we find that we cannot avoid the appearance of a ghost by introducing a second brane in the model

  16. Black holes in the ghost condensate

    International Nuclear Information System (INIS)

    Mukohyama, Shinji

    2005-01-01

    We investigate how the ghost condensate reacts to black holes immersed in it. A ghost condensate defines a hypersurface-orthogonal congruence of timelike curves, each of which has the tangent vector u μ =-g μν ∂ ν φ. It is argued that the ghost condensate in this picture approximately corresponds to a congruence of geodesics. In other words, the ghost condensate accretes into a black hole just like a pressureless dust. Correspondingly, if the energy density of the ghost condensate at large distance is set to an extremely small value by cosmic expansion then the late-time accretion rate of the ghost condensate should be negligible. The accretion rate remains very small even if effects of higher derivative terms are taken into account, provided that the black hole is sufficiently large. It is also discussed how to reconcile the black-hole accretion with the possibility that the ghost condensate might behave like dark matter

  17. Ghost quintessence in fractal gravity

    Indian Academy of Sciences (India)

    In this study, using the time-like fractal theory of gravity, we mainly focus on the ghost ... Here a(t) is the cosmic scale factor and it measures the expansion of the Universe. ..... effectively appear as self-conserved dark energy, with a non-trivial ...

  18. Correspondence between quantum gauge theories without ghost fields and their covariantly quantized theories with ghost fields

    International Nuclear Information System (INIS)

    Cheng Hung; Tsai Ercheng

    1986-01-01

    We give a correspondence formula which equates transition amplitudes in a quantum gauge field theory without ghost fields to those in a quantum theory with the gauge fields covariantly quantized and coupled to ghost fields. (orig.)

  19. Ghost signals in Allison emittance scanners

    International Nuclear Information System (INIS)

    Stockli, Martin P.; Leitner, M.; Moehs, D.P.; Keller, R.; Welton, R.F.

    2004-01-01

    For over 20 years, Allison scanners have been used to measure emittances of low-energy ion beams. We show that scanning large trajectory angles produces ghost signals caused by the sampled beamlet impacting on an electric deflection plate. The ghost signal strength is proportional to the amount of beam entering the scanner. Depending on the ions, and their velocity, the ghost signals can have the opposite or the same polarity as the main beam signals. The ghost signals cause significant errors in the emittance estimates because they appear at large trajectory angles. These ghost signals often go undetected because they partly overlap with the real signals, are mostly below the 1% level, and often hide in the noise. A simple deflection plate modification is shown to reduce the ghost signal strength by over 99%

  20. Ghost Signals In Allison Emittance Scanners

    International Nuclear Information System (INIS)

    Stockli, Martin P.; Leitner, M.; Keller, R.; Moehs, D.P.; Welton, R. F.

    2005-01-01

    For over 20 years, Allison scanners have been used to measure emittances of low-energy ion beams. We show that scanning large trajectory angles produces ghost signals caused by the sampled beamlet impacting on an electric deflection plate. The ghost signal strength is proportional to the amount of beam entering the scanner. Depending on the ions, and their velocity, the ghost signals can have the opposite or the same polarity as the main beam signals. The ghost signals cause significant errors in the emittance estimates because they appear at large trajectory angles. These ghost signals often go undetected because they partly overlap with the real signals, are mostly below the 1% level, and often hide in the noise. A simple deflection plate modification is shown to reduce the ghost signal strength by over 99%

  1. Ghost properties of generalized theories of gravitation

    International Nuclear Information System (INIS)

    Mann, R.B.; Moffat, J.W.

    1982-01-01

    We investigate theories of gravitation, in which spacetime is non-Riemannian and the metric g/sub munu/ is nonsymmetric, for ghosts and tachyons, using a spin-projection operator formalism. Ghosts are removed not by gauge invariance but by a Lagrange multiplier W/sub μ/, which occurs due to the breaking of projective invariance in the theory. Unified theories based on a Lagrangian containing a term lambdag/sup munu/g/sub / are proved to contain ghosts or tachyons

  2. Peripheral dentinogenic ghost cell tumor

    Directory of Open Access Journals (Sweden)

    Sushant S Kamat

    2013-01-01

    Full Text Available Dentinogenic ghost cell tumors (DGCT are uncommon lesions mainly with rare peripheral types. This report presents a case of peripheral DGCT on the left side of the mandibular alveolar ridge of a heavy smoker, a 68-year-old man, with main presenting feature as a mild pain. Submandibular lymphadenopathy and radiological "saucerization" were evident. Differential diagnosis included fibroma, neurofibroma, peripheral ameloblastoma, peripheral odontogenic fibroma, and peripheral giant cell granuloma. Histologically, ameloblastoma-like epithelial elements were seen in association with grouped ghost cells. Proliferating polyhedral cells and stellate reticulum-like cells with various densities were spread over a wide range of the field. The lesion was curetted and after 2 years of follow up, it did not recur.

  3. UV-extending Ghost Inflation

    CERN Document Server

    Ivanov, Mikhail M

    2014-01-01

    We present a setup that provides a partial UV-completion of the ghost inflation model up to a scale which can be almost as high as the Planck mass. This is achieved by coupling the inflaton to the Lorentz-violating sector described by the Einstein-aether theory or its khronometric version. Compared to previous works on ghost inflation our setup allows to go beyond the study of small perturbations and include the background dynamics in a unified framework. In the specific regime when the expansion of the Universe is dominated by the kinetic energy of the inflaton we find that the model predicts rather high tensor-to-scalar ratio r ~ 0.02 $\\div$ 0.2 and non-Gaussianity of equilateral type with f_NL in the range from -50 to -5.

  4. Recovering a hidden polarization by ghost polarimetry.

    Science.gov (United States)

    Janassek, Patrick; Blumenstein, Sébastien; Elsäßer, Wolfgang

    2018-02-15

    By exploiting polarization correlations of light from a broadband fiber-based amplified spontaneous emission source we succeed in reconstructing a hidden polarization in a ghost polarimetry experiment in close analogy to ghost imaging and ghost spectroscopy. Thereby, an original linear polarization state in the object arm of a Mach-Zehnder interferometer configuration which has been camouflaged by a subsequent depolarizer is recovered by correlating it with light from a reference beam. The variation of a linear polarizer placed inside the reference beam results in a Malus law type second-order intensity correlation with high contrast, thus measuring a ghost polarigram.

  5. Entangled spins and ghost-spins

    Directory of Open Access Journals (Sweden)

    Dileep P. Jatkar

    2017-09-01

    Full Text Available We study patterns of quantum entanglement in systems of spins and ghost-spins regarding them as simple quantum mechanical toy models for theories containing negative norm states. We define a single ghost-spin as in [20] as a 2-state spin variable with an indefinite inner product in the state space. We find that whenever the spin sector is disentangled from the ghost-spin sector (both of which could be entangled within themselves, the reduced density matrix obtained by tracing over all the ghost-spins gives rise to positive entanglement entropy for positive norm states, while negative norm states have an entanglement entropy with a negative real part and a constant imaginary part. However when the spins are entangled with the ghost-spins, there are new entanglement patterns in general. For systems where the number of ghost-spins is even, it is possible to find subsectors of the Hilbert space where positive norm states always lead to positive entanglement entropy after tracing over the ghost-spins. With an odd number of ghost-spins however, we find that there always exist positive norm states with negative real part for entanglement entropy after tracing over the ghost-spins.

  6. Ghost imaging with a single detector

    International Nuclear Information System (INIS)

    Bromberg, Yaron; Katz, Ori; Silberberg, Yaron

    2009-01-01

    We experimentally demonstrate pseudothermal ghost imaging and ghost diffraction using only a single detector. We achieve this by replacing the high-resolution detector of the reference beam with a computation of the propagating field, following a recent proposal by Shapiro [Phys. Rev. A 78, 061802(R) (2008)]. Since only a single detector is used, this provides experimental evidence that pseudothermal ghost imaging does not rely on nonlocal quantum correlations. In addition, we show the depth-resolving capability of this ghost imaging technique.

  7. Exorcising ghosts in induced gravity

    Energy Technology Data Exchange (ETDEWEB)

    Narain, Gaurav [Chinese Academy of Sciences (CAS), Key Laboratory of Theoretical Physics, Kavli Institute for Theoretical Physics China (KITPC), Institute of Theoretical Physics, Beijing (China)

    2017-10-15

    Unitarity of the scale-invariant coupled theory of higher-derivative gravity and matter is investigated. A scalar field coupled with a Dirac fermion is taken as the matter sector. Following the idea of induced gravity the Einstein-Hilbert term is generated via dynamical symmetry breaking of scale invariance. The renormalisation group flows are computed and one-loop RG improved effective potential of scalar is calculated. The scalar field develops a new minimum via the Coleman-Weinberg procedure inducing the Newton constant and masses in the matter sector. The spin-2 problematic ghost and the spin-0 mode of the metric fluctuation get a mass in the broken phase of the theory. The energy dependence of the vacuum expectation value in the RG improved scenario implies a running for the induced parameters. This sets up platform to ask whether it is possible to evade the spin-2 ghost by keeping its mass always above the running energy scale? In broken phase this question is satisfactorily answered for a large domain of coupling parameter space where the ghost is evaded. The spin-0 mode can be made physically realisable or not depending upon the choice of the initial parameters. The induced Newton constant is seen to vanish in the ultraviolet case. By properly choosing parameters it is possible to make the matter fields physically unrealisable. (orig.)

  8. Ghost Imaging of Space Objects

    International Nuclear Information System (INIS)

    Strekalov, Dmitry V; Erkmen, Baris I; Yu Nan

    2013-01-01

    The term 'ghost imaging' was coined in 1995 when an optical correlation measurement in combination with an entangled photon-pair source was used to image a mask placed in one optical channel by raster-scanning a detector in the other, empty, optical channel. Later, it was shown that the entangled photon source could be replaced with thermal sources of light, which are abundantly available as natural illumination sources. It was also shown that the bucket detector could be replaced with a remote point-like detector, opening the possibility to remote-sensing imaging applications. In this paper, we discuss the application of ghost-imaging-like techniques to astronomy, with the objective of detecting intensity-correlation signatures resulting from space objects of interest, such as exo-planets, gas clouds, and gravitational lenses. An important aspect of being able to utilize ghost imaging in astronomy, is the recognition that in interstellar imaging geometries the object of interest can act as an effective beam splitter, yielding detectable variations in the intensity-correlation signature.

  9. Infrared behavior of gluons and ghosts in ghost-antighost symmetric gauges

    International Nuclear Information System (INIS)

    Alkofer, R.; Fischer, C.S.; Reinhardt, H.; Smekal, L. von

    2003-01-01

    To investigate the possibility of a ghost-antighost condensate, the coupled Dyson-Schwinger equations for the gluon and ghost propagators in Yang-Mills theories are derived in general covariant gauges, including ghost-antighost symmetric gauges. The infrared behavior of these two-point functions is studied in a bare-vertex truncation scheme which has proven to be successful in the Landau gauge. In all linear covariant gauges the same infrared behavior as in the Landau gauge is found: The gluon propagator is infrared-suppressed whereas the ghost propagator is infrared-enhanced. This infrared singular behavior provides an indication against a ghost-antighost condensate. In the ghost-antighost symmetric gauges we find that the infrared behavior of the gluon and ghost propagators cannot be determined when replacing all dressed vertices by bare ones. The question of a BRS invariant dimension-2 condensate remains to be further studied

  10. Ghost Children: Invisible Middle Level Students

    Science.gov (United States)

    Matteson, Shirley M.

    2014-01-01

    For this study, 119 middle level teacher candidates identified, observed, and documented their interactions with middle school "ghost children" as part of their field placement activities. About two thirds of the 124 ghost children identified for this study were male. The teacher candidates documented additional characteristics of ghost…

  11. Some issues in the ghost condensation scenario

    International Nuclear Information System (INIS)

    Anisimov, A.

    2004-01-01

    In the recently proposed 'ghost condensation' scenario a model of consistent infrared modification of gravity was suggested. We first review the basic ideas of this scenario. We discuss various phenomenological aspects of the ghost condensation, such as stability of the condensate, bounds on the UV cut-off scale of the corresponding effective field theory and other issues. (author)

  12. Are ghosts necessary in planar gauges?

    International Nuclear Information System (INIS)

    Kummer, W.

    1988-01-01

    The introduction of Faddeev-Popov ghosts in axial gauges and especially in the ones of the planar type is not a technical necessity for the general proof of renormalization and gauge independence. It is shown that all necessary identities for Green's functions and for one-particle-irreducible vertices arise in a completely ghost-free formulation as well

  13. Variational method for lattice spectroscopy with ghosts

    International Nuclear Information System (INIS)

    Burch, Tommy; Hagen, Christian; Gattringer, Christof; Glozman, Leonid Ya.; Lang, C.B.

    2006-01-01

    We discuss the variational method used in lattice spectroscopy calculations. In particular we address the role of ghost contributions which appear in quenched or partially quenched simulations and have a nonstandard euclidean time dependence. We show that the ghosts can be separated from the physical states. Our result is illustrated with numerical data for the scalar meson

  14. Accretion of Ghost Condensate by Black Holes

    Energy Technology Data Exchange (ETDEWEB)

    Frolov, A

    2004-06-02

    The intent of this letter is to point out that the accretion of a ghost condensate by black holes could be extremely efficient. We analyze steady-state spherically symmetric flows of the ghost fluid in the gravitational field of a Schwarzschild black hole and calculate the accretion rate. Unlike minimally coupled scalar field or quintessence, the accretion rate is set not by the cosmological energy density of the field, but by the energy scale of the ghost condensate theory. If hydrodynamical flow is established, it could be as high as tenth of a solar mass per second for 10MeV-scale ghost condensate accreting onto a stellar-sized black hole, which puts serious constraints on the parameters of the ghost condensate model.

  15. Polarization-multiplexing ghost imaging

    Science.gov (United States)

    Dongfeng, Shi; Jiamin, Zhang; Jian, Huang; Yingjian, Wang; Kee, Yuan; Kaifa, Cao; Chenbo, Xie; Dong, Liu; Wenyue, Zhu

    2018-03-01

    A novel technique for polarization-multiplexing ghost imaging is proposed to simultaneously obtain multiple polarimetric information by a single detector. Here, polarization-division multiplexing speckles are employed for object illumination. The light reflected from the objects is detected by a single-pixel detector. An iterative reconstruction method is used to restore the fused image containing the different polarimetric information by using the weighted sum of the multiplexed speckles based on the correlation coefficients obtained from the detected intensities. Next, clear images of the different polarimetric information are recovered by demultiplexing the fused image. The results clearly demonstrate that the proposed method is effective.

  16. Ghost condensation and a consistent IR modification of gravity

    International Nuclear Information System (INIS)

    Arkani Hamed, N.; Cheng, H.S.; Luty, M.A.; Mukohyama, S.

    2004-01-01

    We propose a theoretically consistent modification of gravity in the infrared, which is compatible with all current experimental observations. This is an analog of Higgs mechanism in general relativity, and can be thought of as arising from ghost condensation-a background where a scalar field φhas a constant velocity, = M 2 . The ghost condensate is a new kind of fluid that can fill the universe, which has the same equation of state, ρ = -p, as a cosmological constant, and can hence drive de Sitter expansion of the universe. However, unlike a cosmological constant, it is a physical fluid with a physical scalar excitation, which can be described by a systematic effective field theory at low energies. The excitation has an unusual low-energy dispersion relation ω 2 ∼ k 4 /M 2 . If coupled to matter directly, it gives rise to small Lorentz-violating effects and a new long-range 1/r 2 spin dependent force. In the ghost condensate, the energy that gravitates is not the same as the particle physics energy, leading to the possibility of both sources that can gravitate and antigravitate. The Newtonian potential is modified with an oscillatory behavior starting at the distance scale M Pl /M 2 and the time scale M Pl 2 /M 3 . This theory opens up a number of new avenues for attacking cosmological problems, including inflation, dark matter and dark energy. (author)

  17. Non-perturbative materialization of ghosts

    International Nuclear Information System (INIS)

    Emparan, Roberto; Garriga, Jaume

    2006-01-01

    In theories with a hidden ghost sector that couples to visible matter through gravity only, empty space can decay into ghosts and ordinary matter by graviton exchange. Perturbatively, such processes can be very slow provided that the gravity sector violates Lorentz invariance above some cut-off scale. Here, we investigate non-perturbative decay processes involving ghosts, such as the spontaneous creation of self-gravitating lumps of ghost matter, as well as pairs of Bondi dipoles (i.e. lumps of ghost matter chasing after positive energy objects). We find the corresponding instantons and calculate their Euclidean action. In some cases, the instantons induce topology change or have negative Euclidean action. To shed some light on the meaning of such peculiarities, we also consider the nucleation of concentrical domain walls of ordinary and ghost matter, where the Euclidean calculation can be compared with the canonical (Lorentzian) description of tunneling. We conclude that non-perturbative ghost nucleation processes can be safely suppressed in phenomenological scenarios

  18. IR finiteness of the ghost dressing function from numerical resolution of the ghost SD equation

    International Nuclear Information System (INIS)

    Boucaud, Ph.; Leroy, J.P.; Yaouanc, A. Le; Micheli, J.; Pene, O.; RodrIguez-Quintero, J.

    2008-01-01

    We solve numerically the Schwinger-Dyson ghost equation in the Landau gauge for a given, finite at k = 0 gluon propagator (i.e. the infrared exponent of its dressing function, α gluon , is 1) and under the usual assumption of constancy of the ghost-gluon vertex ; we show that there exist two possible types of ghost dressing function solutions, as we have previously inferred from analytical considerations: one which is singular at zero momentum (the infrared exponent of its dressing function, α ghost , (We shall use α G and α F as shorthands for α gluon and α ghost respectively; let us recall that we denote the gluon by a G and the ghost by a F, for ''fantome''.) is gluon +2α ghost = 0 and has therefore α ghost = -1/2, and another one which is finite at the origin with α ghost = 0 and violates the relation. It is most important that the type of solution which is realized depends on the value of the coupling constant. There are regular ones - α F = 0 - for any coupling below some value, while there is only one singular solution - α F <0 -, obtained for a single critical value of the coupling. For all momenta k <.5 GeV where they can be trusted, our lattice data exclude neatly the singular one, and agree very well with the regular solution we obtain at a coupling constant compatible with the bare lattice value.

  19. Ghosts of No Child Left Behind. Counterpoints: Studies in the Postmodern Theory of Education. Volume 361

    Science.gov (United States)

    Carris, Joanne M.

    2011-01-01

    "Ghosts of No Child Left Behind" politically situates curriculum within a historically and critically informed context, to understand the structural forces that have contributed to the creation of a population of adolescents who read below a third grade level. The book then proposes a reconceptualization of literacy curriculum within a…

  20. Dermot Bolger’s Ghosting the War

    Directory of Open Access Journals (Sweden)

    Aleksandra Kędzierska

    2017-10-01

    Full Text Available Dermot Bolger’s Walking the Road (2007 is a tribute to Francis Ledwidge (1887–1917, one of the greatest Irish poets of the First World War. Focusing on the life and afterlife of Ledwidge who, as depicted in Bolger’s play, emblematizes the condition of other Great War combatants doomed to oblivion, this essay, concerned with the various functions of the deployment of ghosts in Bolger’s drama, argues that spectrality can become an effective means of revealing the plight of the war dead: the unremembered, whose names were effectively erased from public memory and who, thus turned into homeless revenants, were forced into a continual involvement in the war from which they cannot escape, even after death. As a spectral witness who moves between pre-war Ireland and the world of the trenches, Bolger’s hero makes one aware how similar these realities are. Furthermore, as a classic case of shell shock, he demonstrates the role of haunting in the narrative of trauma, identity and memory. Last but not least, whilst enhancing the gothic dimension of the war, Frank’s perceptions, as well as his spectral discourse, not only contribute significantly to illuminating the enigma which he personified, but, by providing an insight into his search for himself, they convey the plight of truth seekers who grasp, yet never fully encompass the Irish experience of the war.

  1. Tensor ghosts in the inflationary cosmology

    International Nuclear Information System (INIS)

    Clunan, Tim; Sasaki, Misao

    2010-01-01

    Theories with curvature-squared terms in the action are known to contain ghost modes in general. However, if we regard curvature-squared terms as quantum corrections to the original theory, the emergence of ghosts may be simply due to the perturbative truncation of a full non-perturbative theory. If this is the case, there should be a way to live with ghosts. In this paper, we take the Euclidean path integral approach, in which ghost degrees of freedom can be, and are integrated out in the Euclideanized spacetime. We apply this procedure to Einstein gravity with a Weyl curvature-squared correction in the inflationary background. We find that the amplitude of tensor perturbations is modified by a term of O(α 2 H 2 ) where α 2 is a coupling constant in front of the Weyl-squared term and H is the Hubble parameter during inflation.

  2. High-quality compressive ghost imaging

    Science.gov (United States)

    Huang, Heyan; Zhou, Cheng; Tian, Tian; Liu, Dongqi; Song, Lijun

    2018-04-01

    We propose a high-quality compressive ghost imaging method based on projected Landweber regularization and guided filter, which effectively reduce the undersampling noise and improve the resolution. In our scheme, the original object is reconstructed by decomposing of regularization and denoising steps instead of solving a minimization problem in compressive reconstruction process. The simulation and experimental results show that our method can obtain high ghost imaging quality in terms of PSNR and visual observation.

  3. Ghost lines in Moessbauer relaxation spectra

    International Nuclear Information System (INIS)

    Price, D.C.

    1985-01-01

    The appearance in Moessbauer relaxation spectra of 'ghost' lines, which are narrow lines that do not correspond to transitions between real hyperfine energy levels of the resonant system, is examined. It is shown that in many cases of interest, the appearance of these 'ghost' lines can be interpreted in terms of the relaxational averaging of one or more of the static interactions of the ion. (orig.)

  4. Observability of complex ghosts and tachyons

    International Nuclear Information System (INIS)

    Yamamoto, Hiroshi

    1976-01-01

    The complex ghost introduced previously by the present author is studied from a standpoint whether its effects are observable by experiments or not. According to the theory of complex ghost the scattering cross section of two real particles shows some particular properties. It has a kind of resonance peak at a certain energy which does not conform to the Breit-Wigner formula. It has also a peak for a certain energy transfer, if there exist tachyons. The tachyon is a kind of ghost and is allowed to exist in the theory. Using these properties the complex ghosts are expected to be detected by experiments. The recently observed resonance psi(3.1) is supposed to be the complex ghost of photon, since they have the same quantum numbers. If it is assumed, some properties of the resonance known by experiments are explained naturally to a certain extent. Along the same line it is not unnatural to expect that the photon is also accompanied by a tachyon as a ghost. An experiment to detect the tachyon is proposed. If the angular distribution of elastic electron-positron or electron-electron scattering is observed at a suitably high energy, then a peak will be found in the domain -1< cos theta<1, where it is assumed that the exchanged photon accompanies a tachyon. (auth.)

  5. Infra-red ghost contribution to the gluon Green's functions

    International Nuclear Information System (INIS)

    Paccanoni, F.

    1985-01-01

    The Schwinger-Dyson equations for the ghost propagator and the ghost-ghost-gluon vertex function are studied in the Landau gauge. A confining infra-red singularity is assumed for the gluon propagator and a suitable approximation is devised for the solution of the integral equations. It is found that the bare values of the ghost propagator and coupling cannot be a consistent solution of either equation. It is determined a possible behaviour of the correction factor for the ghost propagator in the small-momentum limit and discussed the consistency of the approximation schemes for the gluon propagator that neglet Faddeev-Popov ghost

  6. Fast ghost imaging and ghost encryption based on the discrete cosine transform

    International Nuclear Information System (INIS)

    Tanha, Mehrdad; Ahmadi-Kandjani, Sohrab; Kheradmand, Reza

    2013-01-01

    We introduce the discrete cosine transform as an advanced compression tool for images in computational ghost imaging. A novel approach to fast imaging and encryption, the discrete cosine transform, promotes the security level of ghost images and reduces the image retrieval time. To discuss the advantages of this technique we compare experimental outcomes with simulated ones. (paper)

  7. Existence, uniqueness and cohomology of the classical BRST charge with ghosts of ghosts

    International Nuclear Information System (INIS)

    Fisch, J.; Stasheff, J.

    1989-01-01

    A complete canonical formulation of the BRST theory of systems with redundant gauge symmetries is presented. These systems include p-form gauge fields, the superparticle, and the superstring. We first define the Koszul-Tate differential and explicitly show how the introduction of the momenta conjugate to the ghosts of ghosts makes it acyclic. The global existence of the BRST generator is then demonstrated, and the BRST charge is proved to be unique up to canonical transformations in the extended phase space, which includes the ghosts. Finally, the BRST cohomology in classical mechanics is investigated and shown to be equal to the cohomology of the exterior derivative along the gauge orbits, as in the irreducible case. This is done by re-expressing the exterior algebra along the gauge orbits as a free differential algebra containing generators of higher degree, which are identified with the ghosts of ghosts. The quantum cohomology is not dealt with. (orig.)

  8. Neutron Ghost Imaging Technology Research on CARR Reactor

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Ghost imaging is also known as quantum imaging. Different from the classical imaging, the neutron ghost imaging is based on the quantum mechanics properties of light field and its intrinsic parallel characteristic, and developed by new optical

  9. Noncanonical quantization-on the coexistence of particles and ghosts

    International Nuclear Information System (INIS)

    Saller, H.

    1988-01-01

    Local interactions of quantized fields are sometimes parametrized with the aid of ghostlike degrees of freedom, e.g., in non-Abelian gauge theories. These ghosts do not necessarily lead to eigenstates of energy. Such a situation requires a discussion of the asymptotic boundary condition for the ghosts, leading to ghost propagation only for timelike distance. Coexisting particle and ghost degrees of freedom in one basic field operator allow the formulation of interactions for such a field without local ambiguities

  10. Are ghost surfaces quadratic-flux-minimizing?

    International Nuclear Information System (INIS)

    Hudson, S.R.; Dewar, R.L.

    2009-01-01

    Two candidates for 'almost-invariant' toroidal surfaces passing through magnetic islands, namely quadratic-flux-minimizing (QFMin) surfaces and ghost surfaces, use families of periodic pseudo-orbits (i.e. paths for which the action is not exactly extremal). QFMin pseudo-orbits, which are coordinate-dependent, are field lines obtained from a modified magnetic field, and ghost-surface pseudo-orbits are obtained by displacing closed field lines in the direction of steepest descent of magnetic action, ∫A.dl. A generalized Hamiltonian definition of ghost surfaces is given and specialized to the usual Lagrangian definition. A modified Hamilton's Principle is introduced that allows the use of Lagrangian integration for calculation of the QFMin pseudo-orbits. Numerical calculations show QFMin and Lagrangian ghost surfaces give very similar results for a chaotic magnetic field perturbed from an integrable case, and this is explained using a perturbative construction of an auxiliary poloidal angle for which QFMin and Lagrangian ghost surfaces are the same up to second order. While presented in the context of 3-dimensional magnetic field line systems, the concepts are applicable to defining almost-invariant tori in other 11/2 degree-of-freedom nonintegrable Lagrangian/Hamiltonian systems.

  11. Ghost hunting—an assessment of ghost particle detection and removal methods for tomographic-PIV

    International Nuclear Information System (INIS)

    Elsinga, G E; Tokgoz, S

    2014-01-01

    This paper discusses and compares several methods, which aim to remove spurious peaks, i.e. ghost particles, from the volume intensity reconstruction in tomographic-PIV. The assessment is based on numerical simulations of time-resolved tomographic-PIV experiments in linear shear flows. Within the reconstructed volumes, intensity peaks are detected and tracked over time. These peaks are associated with particles (either ghosts or actual particles) and are characterized by their peak intensity, size and track length. Peak intensity and track length are found to be effective in discriminating between most ghosts and the actual particles, although not all ghosts can be detected using only a single threshold. The size of the reconstructed particles does not reveal an important difference between ghosts and actual particles. The joint distribution of peak intensity and track length however does, under certain conditions, allow a complete separation of ghosts and actual particles. The ghosts can have either a high intensity or a long track length, but not both combined, like all the actual particles. Removing the detected ghosts from the reconstructed volume and performing additional MART iterations can decrease the particle position error at low to moderate seeding densities, but increases the position error, velocity error and tracking errors at higher densities. The observed trends in the joint distribution of peak intensity and track length are confirmed by results from a real experiment in laminar Taylor–Couette flow. This diagnostic plot allows an estimate of the number of ghosts that are indistinguishable from the actual particles. (paper)

  12. GHOST: global hepatitis outbreak and surveillance technology.

    Science.gov (United States)

    Longmire, Atkinson G; Sims, Seth; Rytsareva, Inna; Campo, David S; Skums, Pavel; Dimitrova, Zoya; Ramachandran, Sumathi; Medrzycki, Magdalena; Thai, Hong; Ganova-Raeva, Lilia; Lin, Yulin; Punkova, Lili T; Sue, Amanda; Mirabito, Massimo; Wang, Silver; Tracy, Robin; Bolet, Victor; Sukalac, Thom; Lynberg, Chris; Khudyakov, Yury

    2017-12-06

    Hepatitis C is a major public health problem in the United States and worldwide. Outbreaks of hepatitis C virus (HCV) infections associated with unsafe injection practices, drug diversion, and other exposures to blood are difficult to detect and investigate. Effective HCV outbreak investigation requires comprehensive surveillance and robust case investigation. We previously developed and validated a methodology for the rapid and cost-effective identification of HCV transmission clusters. Global Hepatitis Outbreak and Surveillance Technology (GHOST) is a cloud-based system enabling users, regardless of computational expertise, to analyze and visualize transmission clusters in an independent, accurate and reproducible way. We present and explore performance of several GHOST implemented algorithms using next-generation sequencing data experimentally obtained from hypervariable region 1 of genetically related and unrelated HCV strains. GHOST processes data from an entire MiSeq run in approximately 3 h. A panel of seven specimens was used for preparation of six repeats of MiSeq libraries. Testing sequence data from these libraries by GHOST showed a consistent transmission linkage detection, testifying to high reproducibility of the system. Lack of linkage among genetically unrelated HCV strains and constant detection of genetic linkage between HCV strains from known transmission pairs and from follow-up specimens at different levels of MiSeq-read sampling indicate high specificity and sensitivity of GHOST in accurate detection of HCV transmission. GHOST enables automatic extraction of timely and relevant public health information suitable for guiding effective intervention measures. It is designed as a virtual diagnostic system intended for use in molecular surveillance and outbreak investigations rather than in research. The system produces accurate and reproducible information on HCV transmission clusters for all users, irrespective of their level of bioinformatics

  13. Exorcising the Ostrogradsky ghost in coupled systems

    Energy Technology Data Exchange (ETDEWEB)

    Klein, Remko; Roest, Diederik [Van Swinderen Institute for Particle Physics and Gravity, University of Groningen, Nijenborgh 4, 9747 AG Groningen (Netherlands)

    2016-07-27

    The Ostrogradsky theorem implies that higher-derivative terms of a single mechanical variable are either trivial or lead to additional, ghost-like degrees of freedom. In this letter we systematically investigate how the introduction of additional variables can remedy this situation. Employing a Lagrangian analysis, we identify conditions on the Lagrangian to ensure the existence of primary and secondary constraints that together imply the absence of Ostrogradsky ghosts. We also show the implications of these conditions for the structure of the equations of motion as well as possible redefinitions of the variables. We discuss applications to analogous higher-derivative field theories such as multi-Galileons and beyond Horndeski.

  14. Exorcising the Ostrogradsky ghost in coupled systems

    International Nuclear Information System (INIS)

    Klein, Remko; Roest, Diederik

    2016-01-01

    The Ostrogradsky theorem implies that higher-derivative terms of a single mechanical variable are either trivial or lead to additional, ghost-like degrees of freedom. In this letter we systematically investigate how the introduction of additional variables can remedy this situation. Employing a Lagrangian analysis, we identify conditions on the Lagrangian to ensure the existence of primary and secondary constraints that together imply the absence of Ostrogradsky ghosts. We also show the implications of these conditions for the structure of the equations of motion as well as possible redefinitions of the variables. We discuss applications to analogous higher-derivative field theories such as multi-Galileons and beyond Horndeski.

  15. Ghost number anomaly in the Polyakov's light-cone gauge

    International Nuclear Information System (INIS)

    Suzuki, Hiroshi.

    1990-06-01

    The conformal (Weyl) anomaly of the ghost-anti-ghost system in the two-dimentional quantum gravity is calculated. A background covariant formalism allows us to treat the Polyakov's light-cone gauge in a systematic way. The anomaly gives a contribution to the central charge, -28, which agrees with the result of Kniznik, Polyakov and Zamolodchikov. The ghost number anomaly is also calculated, and the metric corrections to the naive ghost number current are given. It is suggested that a general scalar density in the light-cone gauge carries a screening ghost number. (author)

  16. Numerical Study of the Ghost-Ghost-Gluon Vertex on the Lattice

    International Nuclear Information System (INIS)

    Mihara, A.; Cucchieri, A.; Mendes, T.

    2004-01-01

    It is well known that, in Landau gauge, the renormalization function of the ghost-ghost-gluon vertex Z-tilde1 (p2) is finite and constant, at least to all orders of perturbation theory. On the other hand, a direct non-perturbative verification of this result using numerical simulations of lattice QCD is still missing. Here we present a preliminary numerical study of the ghost-ghost-gluon vertex and of its corresponding renormalization function using Monte Carlo simulations in SU(2) lattice Landau gauge. Data were obtained in 4 dimensions for lattice couplings β = 2.2, 2.3, 2.4 and lattice sides N = 4, 8, 16

  17. Numerical study of the ghost-ghost-gluon vertex on the lattice

    International Nuclear Information System (INIS)

    Mihara, A.; Cucchieri, A.; Mendes, T.

    2004-01-01

    It is well known that, in Landau gauge, the renormalization function of the ghost-ghost-gluon vertex Z∼ 1 1(p 2 ) is finite and constant, at least to all orders of perturbation theory. On the other hand, a direct non-perturbative verification of this result using numerical simulations of lattice QCD is still missing. Here we present a preliminary numerical study of the ghost-ghost-gluon vertex and of its corresponding renormalization function using Monte Carlo simulations in SU(2) lattice Landau gauge. Data were obtained in 4 dimensions for lattice couplings β= 2.2, 2.3, 2.4 and lattice sides N = 4, 8, 16. (author)

  18. 'Ghost of Mirach' Rears its Spooky Head

    Science.gov (United States)

    2008-01-01

    [figure removed for brevity, see original site] [figure removed for brevity, see original site] [figure removed for brevity, see original site] Visible/DSS Click on image for larger version Ultraviolet/GALEX Click on image for larger version Poster Version Click on image for larger version The 'Ghost of Mirach' galaxy is shown in visible light on the left, and in ultraviolet as seen by NASA's Galaxy Evolution Explorer on the right. The fields of view are identical in both pictures, with the Ghost of Mirach a galaxy called NGC 404 seen as the whitish spot in the center of the images. Mirach is a red giant star that looms large in visible light. Because NGC 404 is lost in the glare of this star, it was nicknamed the Ghost of Mirach. But when the galaxy is viewed in ultraviolet light, it comes to 'life,' revealing a never-before-seen ring. This ring, seen in blue in the picture on the right, contains new stars a surprise considering that the galaxy was previously thought to be, essentially, dead. The field of view spans 55,000 light years across. The Ghost of Mirach is located 11 million light-years from Earth. The star Mirach is very close in comparison it is only 200 light-years away and is visible with the naked eye. The visible data come from the Digitized Sky Survey of the Space Telescope Science Institute in Baltimore, Md.

  19. Optical encryption with selective computational ghost imaging

    International Nuclear Information System (INIS)

    Zafari, Mohammad; Kheradmand, Reza; Ahmadi-Kandjani, Sohrab

    2014-01-01

    Selective computational ghost imaging (SCGI) is a technique which enables the reconstruction of an N-pixel image from N measurements or less. In this paper we propose an optical encryption method based on SCGI and experimentally demonstrate that this method has much higher security under eavesdropping and unauthorized accesses compared with previous reported methods. (paper)

  20. Gribov's horizon and the ghost dressing function

    International Nuclear Information System (INIS)

    Boucaud, Ph.; Leroy, J. P.; Le Yaouanc, A.; Micheli, J.; Pene, O.; Rodriguez-Quintero, J.

    2009-01-01

    We study a relation recently derived by K. Kondo at zero momentum between the Zwanziger's horizon function, the ghost dressing function and Kugo's functions u and w. We agree with this result as far as bare quantities are considered. However, assuming the validity of the horizon gap equation, we argue that the solution w(0)=0 is not acceptable since it would lead to a vanishing renormalized ghost dressing function. On the contrary, when the cutoff goes to infinity, u(0)→∞, w(0)→-∞ such that u(0)+w(0)→-1. Furthermore w and u are not multiplicatively renormalizable. Relaxing the gap equation allows w(0)=0 with u(0)→-1. In both cases the bare ghost dressing function, F(0,Λ), goes logarithmically to infinity at infinite cutoff. We show that, although the lattice results provide bare results not so different from the F(0,Λ)=3 solution, this is an accident due to the fact that the lattice cutoffs lie in the range 1-3 GeV -1 . We show that the renormalized ghost dressing function should be finite and nonzero at zero momentum and can be reliably estimated on the lattice up to powers of the lattice spacing; from published data on a 80 4 lattice at β=5.7 we obtain F R (0,μ=1.5 GeV)≅2.2.

  1. Lucia's Ghosts: Sonic, Gothic, and Postmodern

    DEFF Research Database (Denmark)

    Fillerup, Jessie

    2016-01-01

    In this article, I use an intertextual interference – the spectral presence of Norma Desmond in a performance of Donizetti’s Lucia di Lammermoor – as a locus through which to explore the consequences of the ‘open’ text in theatrical spectatorship, criticism and historical study. Norma’s ghosting...

  2. The Color Antisymmetric Ghost Propagator and One-Loop Vertex Renormalization

    OpenAIRE

    Furui, Sadataka

    2007-01-01

    The color matrix elements of the ghost triangle diagram that appears in the triple gluon vertex and the ghost-ghost-gluon triangle diagram that appears in the ghost-gluon-ghost vertex are calculated. The ghost-ghost-gluon triangle contains a loop consisting of two color diagonal ghosts and one gluon and a loop consisting of two color antisymmetric ghosts and one gluon. Consequently, the pQCD argument in the infrared region based on the one particle irreducible diagram should be modified. Impl...

  3. The color antisymmetric ghost propagator and one-loop vertex renormalization

    International Nuclear Information System (INIS)

    Furui, Sadataka

    2008-01-01

    The color matrix elements of the ghost triangle diagram that appears in the triple gluon vertex and the ghost-ghost-gluon triangle diagram that appears in the ghost-gluon-ghost vertex are calculated. The ghost-ghost-gluon triangle contains a loop consisting of two color diagonal ghosts and one gluon and a loop consisting of two color antisymmetric ghosts and one gluon. Consequently, the pQCD argument in the infrared region based on the one particle irreducible diagram should be modified. Implications for the Kugo-Ojima color confinement and the QCD running coupling are discussed. (author)

  4. Biological amine transport in chromaffin ghosts. Coupling to the transmembrane proton and potential gradients.

    Science.gov (United States)

    Johnson, R G; Pfister, D; Carty, S E; Scarpa, A

    1979-11-10

    The effect of the transmembrane proton gradient (delta pH) and potential gradient (delta psi) upon the rate and extent of amine accumulation was investigated in chromaffin ghosts. The chromaffin ghosts were formed by hypo-osmotic lysis of isolated bovine chromaffin granules and extensive dialysis in order to remove intragranular binding components and dissipate the endogenous electrochemical gradients. Upon ATP addition to suspensions of chromaffin ghosts, a transmembrane proton gradient alone, a transmembrane gradient alone, or both, could be established, depending upon the compositions of the media in which the ghosts were formed and resuspended. When chloride was present in the medium, addition of ATP resulted in the generation of a transmembrane proton gradient, acidic inside of 1 pH unit (measured by [14C]methylamine distribution), and no transmembrane potential (measured by [14C]-thiocyanate distribution). When ATP was added to chromaffin ghosts suspended in a medium in which chloride was substituted by isethionate, a transmembrane potential, inside positive, of 45 mV and no transmembrane proton gradient, was measured. In each medium, the addition of agents known to affect proton or potential gradients, respectively, exerted a predictable mechanism of action. Accumulation of [14C]epinephrine or [14C]5-hydroxytryptamine was over 1 order of magnitude greater in the presence of the transmembrane proton gradient or the transmembrane potential than in the absence of any gradient and, moreover, was related to the magnitude of the proton or potential gradient in a dose-dependent manner. When ghosts were added to a medium containing chloride and isethionate, both a delta pH and delta psi could be generated upon addition of ATP. In this preparation, the maximal rate of amine accumulation was observed. The results indicate that amine accumulation into chromaffin ghosts can occur in the presence of either a transmembrane proton gradient, or a transmembrane potential

  5. THE REPRESENTATION OF THE GHOST ARCHETYPE IN THE CANTERVILLE GHOST BY OSCAR WILDE

    Directory of Open Access Journals (Sweden)

    Safaryan Agata Vladimirovna

    2015-03-01

    Full Text Available The article touches upon the actual interdisciplinary problems of modern cognitive linguistics, psychology, literary criticism and is related to the study of the archetypal representations of ethnicity and changes reflected in the linguistic consciousness. These changes are mainly influenced by the works of fiction and the role of writer's worldview in their formation. Guided by the thesis of universality of the archetypes, the author mentions that though the archetype represents the inherent characteristics of certain ethnic and cultural space, it retains the features which make an image recognizable at all times. By this fact the author explains the existence of beliefs in ghosts with different embodiments in all cultures. The awakening of the archetype is caused by certain historical events, i.e. the revival and further embodiment of the ghost archetype was the result of reversion to the cultural heritage during the Victorian England. The complex analysis of the means of speech representation that called up the realization of the ghost archetype in Oscar Wilde's short story The Canterville Ghost allowed to reveal that alongside with features that constitute the archetypal nature of ghosts in general, there appear the ones peculiar to the author's individual worldview, which either complement or change the existing notions about this being from another world.

  6. Infrared finite ghost propagator in the Feynman gauge

    International Nuclear Information System (INIS)

    Aguilar, A. C.; Papavassiliou, J.

    2008-01-01

    We demonstrate how to obtain from the Schwinger-Dyson equations of QCD an infrared finite ghost propagator in the Feynman gauge. The key ingredient in this construction is the longitudinal form factor of the nonperturbative gluon-ghost vertex, which, contrary to what happens in the Landau gauge, contributes nontrivially to the gap equation of the ghost. The detailed study of the corresponding vertex equation reveals that in the presence of a dynamical infrared cutoff this form factor remains finite in the limit of vanishing ghost momentum. This, in turn, allows the ghost self-energy to reach a finite value in the infrared, without having to assume any additional properties for the gluon-ghost vertex, such as the presence of massless poles. The implications of this result and possible future directions are briefly outlined

  7. Kinetic k-essence ghost dark energy model

    International Nuclear Information System (INIS)

    Rozas-Fernández, Alberto

    2012-01-01

    A ghost dark energy model has been recently put forward to explain the current accelerated expansion of the Universe. In this model, the energy density of ghost dark energy, which comes from the Veneziano ghost of QCD, is proportional to the Hubble parameter, ρ D =αH. Here α is a constant of order Λ QCD 3 where Λ QCD ∼100 MeV is the QCD mass scale. We consider a connection between ghost dark energy with/without interaction between the components of the dark sector and the kinetic k-essence field. It is shown that the cosmological evolution of the ghost dark energy dominated Universe can be completely described a kinetic k-essence scalar field. We reconstruct the kinetic k-essence function F(X) in a flat Friedmann-Robertson-Walker Universe according to the evolution of ghost dark energy density.

  8. Ghost problem of quantum field theories with higher derivatives

    International Nuclear Information System (INIS)

    Gavrielides, A.; Kuo, T.K.; Lee, S.Y.

    1976-01-01

    Second-order theories, i.e., theories described by Lagrangians quadratic in second derivatives of the fields, are carefully examined and their ghost problems are isolated and clearly exhibited. In particular, theories with gauge symmetry are shown to have precisely the same ghost problems as theories without gauge symmetry. It is also shown that massless theories of the same nature are the limit of massive theories containing ghost states

  9. BRST cohomology of the superstring at arbitrary ghost number

    International Nuclear Information System (INIS)

    Horowitz, G.T.; Myers, R.C.; Martin, S.P.

    1989-01-01

    We investigate the cohomology of the BRST operator of the NSR superstring. No restriction is placed on the ghost number of the states. It is shown that every cohomology class can be written as a picture changed version of one of the known cohomology classes at a fixed ghost number. A generalization of this result is also found for the cohomology in the large algebra of a new bosonization of the superconformal ghosts. (orig.)

  10. Building Shadow Detection from Ghost Imagery

    Science.gov (United States)

    Zhou, G.; Sha, J.; Yue, T.; Wang, Q.; Liu, X.; Huang, S.; Pan, Q.; Wei, J.

    2018-05-01

    Shadow is one of the basic features of remote sensing image, it expresses a lot of information of the object which is loss or interference, and the removal of shadow is always a difficult problem to remote sensing image processing. In this paper, it is mainly analyzes the characteristics and properties of shadows from the ghost image (traditional orthorectification). The DBM and the interior and exterior orientation elements of the image are used to calculate the zenith angle of sun. Then this paper combines the scope of the architectural shadows which has be determined by the zenith angle of sun with the region growing method to make the detection of architectural shadow areas. This method lays a solid foundation for the shadow of the repair from the ghost image later. It will greatly improve the accuracy of shadow detection from buildings and make it more conducive to solve the problem of urban large-scale aerial imagines.

  11. Ghost imaging based on Pearson correlation coefficients

    International Nuclear Information System (INIS)

    Yu Wen-Kai; Yao Xu-Ri; Liu Xue-Feng; Li Long-Zhen; Zhai Guang-Jie

    2015-01-01

    Correspondence imaging is a new modality of ghost imaging, which can retrieve a positive/negative image by simple conditional averaging of the reference frames that correspond to relatively large/small values of the total intensity measured at the bucket detector. Here we propose and experimentally demonstrate a more rigorous and general approach in which a ghost image is retrieved by calculating a Pearson correlation coefficient between the bucket detector intensity and the brightness at a given pixel of the reference frames, and at the next pixel, and so on. Furthermore, we theoretically provide a statistical interpretation of these two imaging phenomena, and explain how the error depends on the sample size and what kind of distribution the error obeys. According to our analysis, the image signal-to-noise ratio can be greatly improved and the sampling number reduced by means of our new method. (paper)

  12. BUILDING SHADOW DETECTION FROM GHOST IMAGERY

    Directory of Open Access Journals (Sweden)

    G. Zhou

    2018-05-01

    Full Text Available Shadow is one of the basic features of remote sensing image, it expresses a lot of information of the object which is loss or interference, and the removal of shadow is always a difficult problem to remote sensing image processing. In this paper, it is mainly analyzes the characteristics and properties of shadows from the ghost image (traditional orthorectification. The DBM and the interior and exterior orientation elements of the image are used to calculate the zenith angle of sun. Then this paper combines the scope of the architectural shadows which has be determined by the zenith angle of sun with the region growing method to make the detection of architectural shadow areas. This method lays a solid foundation for the shadow of the repair from the ghost image later. It will greatly improve the accuracy of shadow detection from buildings and make it more conducive to solve the problem of urban large-scale aerial imagines.

  13. Superrenormalizable quantum gravity with complex ghosts

    Directory of Open Access Journals (Sweden)

    Leonardo Modesto

    2016-04-01

    Full Text Available We suggest and briefly review a new sort of superrenormalizable models of higher derivative quantum gravity. The higher derivative terms in the action can be introduced in such a way that all the unphysical massive states have complex poles. According to the literature on Lee–Wick quantization, in this case the theory can be formulated as unitary, since all massive ghosts-like degrees of freedom are unstable. Keywords: Quantum gravity, Higher derivatives, Complex poles

  14. Honorary and ghost authorship in nursing publications.

    Science.gov (United States)

    Kennedy, Maureen Shawn; Barnsteiner, Jane; Daly, John

    2014-11-01

    The purposes of this study were to (a) assess the prevalence of articles with honorary authors and ghost authors in 10 leading peer-reviewed nursing journals between 2010 to 2012; (b) compare the results to prevalence reported by authors of articles published in high-impact medical journals; and (c) assess the experiences of editors in the International Academy of Nursing Editors with honorary and guest authorship. Corresponding authors of articles published in 10 nursing journals between 2010 and 2012 were invited to complete an online survey about the contributions of coauthors to see if the International Committee of Medical Journal Editors () criteria for authorship were met. Additionally, members of the International Academy of Nursing Editors were invited to complete an online survey about their experiences in identifying honorary or ghost authors in articles submitted for publication. The prevalence of articles published in 10 nursing journals with honorary authors was 42%, and the prevalence of ghost authorship was 27.6%. This is a greater prevalence than what has been reported among medical journals. Qualitative data yielded five themes: lack of awareness around the rules for authorship; acknowledged need for debate, discussion, and promotion of ethical practice; knowingly tolerating, and sometimes deliberately promoting, transgressions in practice; power relations and expectations; and avoiding scrutiny. Among the 60 respondents to the editor survey, 22 (36.7%) reported identifying honorary authors and 13 (21.7%) reported ghost authors among papers submitted to their publications. Inappropriate authorship is a significant problem among scholarly nursing publications. If nursing scholarship is to maintain integrity and be considered trustworthy, and if publications are to be a factor in professional advancement, editors, nursing leaders, and faculty need to disseminate and adhere to ethical authorship practices. © 2014 Sigma Theta Tau International.

  15. Lucia's Ghosts: Sonic, Gothic, and Postmodern

    DEFF Research Database (Denmark)

    Fillerup, Jessie

    2016-01-01

    In this article, I use an intertextual interference – the spectral presence of Norma Desmond in a performance of Donizetti’s Lucia di Lammermoor – as a locus through which to explore the consequences of the ‘open’ text in theatrical spectatorship, criticism and historical study. Norma’s ghosting...... the lens of Sunset Boulevard inverts chronological sequence, it acknowledges the temporal contradictions inherent in historical work and assigns productive meaning to nostalgic impulses that engage a reflective mode of thought....

  16. Ghost Imaging Using Orbital Angular Momentum

    Institute of Scientific and Technical Information of China (English)

    赵生妹; 丁建; 董小亮; 郑宝玉

    2011-01-01

    We present a novel encoding scheme in a ghost-imaging system using orbital angular momentum. In the signal arm, object spatial information is encoded as a phase matrix. For an N-grey-scale object, different phase matrices, varying from 0 to K with increment n/N, are used for different greyscales, and then they are modulated to a signal beam by a spatial light modulator. According to the conservation of the orbital angular momentum in the ghost imaging system, these changes will give different coincidence rates in measurement, and hence the object information can be extracted in the idler arm. By simulations and experiments, the results show that our scheme can improve the resolution of the image effectively. Compared with another encoding method using orbital angular momentum, our scheme has a better performance for both characters and the image object.%We present a novel encoding scheme in a ghost-imaging system using orbital angular momentum.In the signal arm,object spatial information is encoded as a phase matrix.For an N-grey-scale object,different phase matrices,varying from 0 to π with increment π/N,are used for different greyscales,and then they are modulated to a signal beam by a spatial light modulator.According to the conservation of the orbital angular momentum in the ghost imaging system,these changes will give different coincidence rates in measurement,and hence the object information can be extracted in the idler arm.By simulations and experiments,the results show that our scheme can improve the resolution of the image effectively.Compared with another encoding method using orbital angular momentum,our scheme has a better performance for both characters and the image object.

  17. Superconformal ghost correlators and picture changing

    International Nuclear Information System (INIS)

    Bonini, M.; Iengo, R.; Nunez, C.

    1988-12-01

    We compute the correlation functions for the system of superconformal ghosts β, γ(λ=3/2), including the corresponding spin fields, on arbitrary Riemann surfaces. Using fermionization, defined as a change of variables in the functional integration, we derive and generalize previous results obtained by bosonization. As an application we study the picture changing mechanism in the Ramond sector of the superstring. (author). 11 refs

  18. Superrenormalizable quantum gravity with complex ghosts

    Energy Technology Data Exchange (ETDEWEB)

    Modesto, Leonardo, E-mail: lmodesto@fudan.edu.cn [Department of Physics & Center for Field Theory and Particle Physics, Fudan University, 200433, Shanghai (China); Shapiro, Ilya L., E-mail: shapiro@fisica.ufjf.br [Departamento de Fisica – ICE, Universidade Federal de Juiz de Fora, 33036-900 Juiz de Fora, Minas Gerais (Brazil); Tomsk State Pedagogical University and Tomsk State University, 634041, Tomsk (Russian Federation)

    2016-04-10

    We suggest and briefly review a new sort of superrenormalizable models of higher derivative quantum gravity. The higher derivative terms in the action can be introduced in such a way that all the unphysical massive states have complex poles. According to the literature on Lee–Wick quantization, in this case the theory can be formulated as unitary, since all massive ghosts-like degrees of freedom are unstable.

  19. Vertex operators of ghost number three in Type IIB supergravity

    International Nuclear Information System (INIS)

    Mikhailov, Andrei

    2016-01-01

    We study the cohomology of the massless BRST complex of the Type IIB pure spinor superstring in flat space. In particular, we find that the cohomology at the ghost number three is nontrivial and transforms in the same representation of the supersymmetry algebra as the solutions of the linearized classical supergravity equations. Modulo some finite dimensional spaces, the ghost number three cohomology is the same as the ghost number two cohomology. We also comment on the difference between the naive and semi-relative cohomology, and the role of b-ghost.

  20. QCD ghost f(T)-gravity model

    Energy Technology Data Exchange (ETDEWEB)

    Karami, K.; Abdolmaleki, A.; Asadzadeh, S. [University of Kurdistan, Department of Physics, Sanandaj (Iran, Islamic Republic of); Safari, Z. [Research Institute for Astronomy and Astrophysics of Maragha (RIAAM), Maragha (Iran, Islamic Republic of)

    2013-09-15

    Within the framework of modified teleparallel gravity, we reconstruct a f(T) model corresponding to the QCD ghost dark energy scenario. For a spatially flat FRW universe containing only the pressureless matter, we obtain the time evolution of the torsion scalar T (or the Hubble parameter). Then, we calculate the effective torsion equation of state parameter of the QCD ghost f(T)-gravity model as well as the deceleration parameter of the universe. Furthermore, we fit the model parameters by using the latest observational data including SNeIa, CMB and BAO data. We also check the viability of our model using a cosmographic analysis approach. Moreover, we investigate the validity of the generalized second law (GSL) of gravitational thermodynamics for our model. Finally, we point out the growth rate of matter density perturbation. We conclude that in QCD ghost f(T)-gravity model, the universe begins a matter dominated phase and approaches a de Sitter regime at late times, as expected. Also this model is consistent with current data, passes the cosmographic test, satisfies the GSL and fits the data of the growth factor well as the {Lambda}CDM model. (orig.)

  1. Computational Ghost Imaging for Remote Sensing

    Science.gov (United States)

    Erkmen, Baris I.

    2012-01-01

    This work relates to the generic problem of remote active imaging; that is, a source illuminates a target of interest and a receiver collects the scattered light off the target to obtain an image. Conventional imaging systems consist of an imaging lens and a high-resolution detector array [e.g., a CCD (charge coupled device) array] to register the image. However, conventional imaging systems for remote sensing require high-quality optics and need to support large detector arrays and associated electronics. This results in suboptimal size, weight, and power consumption. Computational ghost imaging (CGI) is a computational alternative to this traditional imaging concept that has a very simple receiver structure. In CGI, the transmitter illuminates the target with a modulated light source. A single-pixel (bucket) detector collects the scattered light. Then, via computation (i.e., postprocessing), the receiver can reconstruct the image using the knowledge of the modulation that was projected onto the target by the transmitter. This way, one can construct a very simple receiver that, in principle, requires no lens to image a target. Ghost imaging is a transverse imaging modality that has been receiving much attention owing to a rich interconnection of novel physical characteristics and novel signal processing algorithms suitable for active computational imaging. The original ghost imaging experiments consisted of two correlated optical beams traversing distinct paths and impinging on two spatially-separated photodetectors: one beam interacts with the target and then illuminates on a single-pixel (bucket) detector that provides no spatial resolution, whereas the other beam traverses an independent path and impinges on a high-resolution camera without any interaction with the target. The term ghost imaging was coined soon after the initial experiments were reported, to emphasize the fact that by cross-correlating two photocurrents, one generates an image of the target. In

  2. Ghost Whisperer's Ghost in the Machine: An example of pop cultural representation of virtual worlds

    DEFF Research Database (Denmark)

    Reinhard, CarrieLynn D.

    2009-01-01

    Analysis of an episode of the CBS series "Ghost Whisperer" for how it depicts a) what is a virtual world and b) the tensions that are involved in discussing the uses and effects of a virtual world.  Discussion focuses on the overriding negative reception of virtual worlds in popular culture due...

  3. Visions of Inflation in World History: Ghost Story III

    Science.gov (United States)

    Niederjohn, M. Scott; Schug, Mark C.; Wood, William C.

    2013-01-01

    This article represents the third in a "ghost story" series by the same authors. Readers may recall that Mr. Bernanke was "visited" by the ghosts of Adam Smith and John Maynard Keynes in the March/April 2010 issue of "Social Education" as these two famous economists debated the economic recovery (see EJ878912). Mr.…

  4. High visibility temporal ghost imaging with classical light

    Science.gov (United States)

    Liu, Jianbin; Wang, Jingjing; Chen, Hui; Zheng, Huaibin; Liu, Yanyan; Zhou, Yu; Li, Fu-li; Xu, Zhuo

    2018-03-01

    High visibility temporal ghost imaging with classical light is possible when superbunching pseudothermal light is employed. In the numerical simulation, the visibility of temporal ghost imaging with pseudothermal light, equaling (4 . 7 ± 0 . 2)%, can be increased to (75 ± 8)% in the same scheme with superbunching pseudothermal light. The reasons for that the retrieved images are different for superbunching pseudothermal light with different values of degree of second-order coherence are discussed in detail. It is concluded that high visibility and high quality temporal ghost image can be obtained by collecting sufficient number of data points. The results are helpful to understand the difference between ghost imaging with classical light and entangled photon pairs. The superbunching pseudothermal light can be employed to improve the image quality in ghost imaging applications.

  5. Beam Dumping Ghost Signals in Electric Sweep Scanners

    International Nuclear Information System (INIS)

    Stockli, M.P.; Leitner, M.; Keller, R.; Moehs, D.P.; Welton, R.F.

    2005-01-01

    Over the last 20 years many labs started to use Allison scanners to measure low-energy ion beam emittances. We show that large trajectory angles produce ghost signals due to the impact of the beamlet on the electric deflection plates. The strength of the ghost signal is proportional to the amount of beam entering the scanner. Depending on the ions and their velocity, ghost signals can have the opposite polarity as the main beam signals or the same polarity. These ghost signals are easily overlooked because they partly overlap the real signals, they are mostly below the 1% level, and they are often hidden in the noise. However, they cause significant errors in emittance estimates because they are associated with large trajectory angles. The strength of ghost signals, and the associated errors, can be drastically reduced with a simple modification of the deflection plates

  6. Beam dumping ghost signals in electric sweep scanners

    International Nuclear Information System (INIS)

    Stockli, M.P.; SNS Project, Oak Ridge; Tennessee U.; Leitner, M.; LBL, Berkeley; Moehs, D.P.; Keller, R.; LBL, Berkeley; Welton, R.F.; SNS Project, Oak Ridge

    2004-01-01

    Over the last 20 years many labs started to use Allison scanners to measure loW--energy ion beam emittances. We show that large trajectory angles produce ghost signals due to the impact of the beamlet on the electric deflection plates. The strength of the ghost signal is proportional to the amount of beam entering the scanner. Depending on the ions and their velocity, ghost signals can have the opposite polarity as the main beam signals or the same polarity. These ghost signals are easily overlooked because they partly overlap the real signals, they are mostly below the 1% level, and they are often hidden in the noise. However, they cause significant errors in emittance estimates because they are associated with large trajectory angles. The strength of ghost signals, and the associated errors, can be drastically reduced with a simple modification of the deflection plates

  7. Accretion of a ghost condensate by black holes

    International Nuclear Information System (INIS)

    Frolov, Andrei V.

    2004-01-01

    The intent of this paper is to point out that the accretion of a ghost condensate by black holes could be extremely efficient. We analyze steady-state spherically symmetric flows of the ghost fluid in the gravitational field of a Schwarzschild black hole and calculate the accretion rate. Unlike minimally coupled scalar field or quintessence, the accretion rate is set not by the cosmological energy density of the field, but by the energy scale of the ghost condensate theory. If hydrodynamical flow is established, it could be as high as a tenth of a solar mass per second for 10 MeV scale ghost condensate accreting onto a stellar-sized black hole, which puts serious constraints on the parameters of the ghost condensate model

  8. Interacting ghost dark energy in Brans-Dicke theory

    International Nuclear Information System (INIS)

    Ebrahimi, Esmaeil; Sheykhi, Ahmad

    2011-01-01

    We investigate the QCD ghost model of dark energy in the framework of Brans-Dicke cosmology. First, we study the non-interacting ghost dark energy in a flat Brans-Dicke theory. In this case we obtain the equation of state and the deceleration parameters and a differential equation governing the evolution of ghost energy density. Interestingly enough, we find that the equation of state parameter of the non-interacting ghost dark energy can cross the phantom line (w D =-1) provided the parameters of the model are chosen suitably. Then, we generalize the study to the interacting ghost dark energy in both flat and non-flat Brans-Dicke framework and find out that the transition of w D to phantom regime can be more easily achieved for than when resort to the Einstein field equations is made.

  9. Low-momentum ghost dressing function and the gluon mass

    International Nuclear Information System (INIS)

    Boucaud, Ph.; Leroy, J. P.; Le Yaouanc, A.; Micheli, J.; Pene, O.; Gomez, M. E.; Rodriguez-Quintero, J.

    2010-01-01

    We study the low-momentum ghost propagator Dyson-Schwinger equation in the Landau gauge, assuming for the truncation a constant ghost-gluon vertex, as it is extensively done, and a simple model for a massive gluon propagator. Then, regular Dyson-Schwinger equation solutions (the zero-momentum ghost dressing function not diverging) appear to emerge, and we show the ghost propagator to be described by an asymptotic expression reliable up to the order O(q 2 ). That expression, depending on the gluon mass and the zero-momentum Taylor-scheme effective charge, is proven to fit pretty well some low-momentum ghost propagator data [I. L. Bogolubsky, E. M. Ilgenfritz, M. Muller-Preussker, and A. Sternbeck, Phys. Lett. B 676, 69 (2009); Proc. Sci., LAT2007 (2007) 290] from big-volume lattice simulations where the so-called ''simulated annealing algorithm'' is applied to fix the Landau gauge.

  10. Ghost imaging with third-order correlated thermal light

    International Nuclear Information System (INIS)

    Ou, L-H; Kuang, L-M

    2007-01-01

    In this paper, we propose a ghost imaging scheme with third-order correlated thermal light. We show that it is possible to produce the spatial information of an object at two different places in a nonlocal fashion by means of a third-order correlated imaging process with a third-order correlated thermal source and third-order correlation measurement. Concretely, we propose a protocol to create two ghost images at two different places from one object. This protocol involves two optical configurations. We derive the Gaussian thin lens equations and plot the geometrical optics of the ghost imaging processes for the two configurations. It is indicated that third-order correlated ghost imaging with thermal light exhibits richer correlated imaging effects than second-order correlated ghost imaging with thermal light

  11. The Ghostly Workings of Danish Accountability Policies

    DEFF Research Database (Denmark)

    Pors, Justine Grønbæk

    2016-01-01

    present an empirical study of a policy agenda of introducing an assessment culture and improving the management of the Danish public school. I explore how all the routines and habits deemed outdated and sought annihilated by a new policy paradigm continue to haunt head teachers as seething presence...... of lurking resistance towards the policy aims as well as insidious doubts. Thinking about the ghostly contributes to studies of education policy by locating the reality of power in the mundane everyday doings and experiences of educational practitioners and insisting on the very tangled way people sense...... and intuit the complexities of contemporary forms of power....

  12. Ghosted images: old lesbians on screen.

    Science.gov (United States)

    Krainitzki, Eva

    2015-01-01

    Screen images of old lesbians combine modes of representing female gender, lesbian sexuality, and old age, all of which contain layers of otherness within a hetero-patriarchal and youth-centered society. Analyzing a range of films, from independent to mainstream cinema, this article explores how the ghosted lesbian paradigm intersects with narratives of aging as decline in representations of lesbian characters who are over the age of sixty. The spectral matters of illness, death, mourning, and widowhood inevitably culminate in an unhappy ending. Removed from a lesbian community context, intergenerational continuity vanishes and the old lesbian emerges as the cultural other.

  13. Plato's ghost the modernist transformation of mathematics

    CERN Document Server

    Gray, Jeremy

    2008-01-01

    Plato's Ghost is the first book to examine the development of mathematics from 1880 to 1920 as a modernist transformation similar to those in art, literature, and music. Jeremy Gray traces the growth of mathematical modernism from its roots in problem solving and theory to its interactions with physics, philosophy, theology, psychology, and ideas about real and artificial languages. He shows how mathematics was popularized, and explains how mathematical modernism not only gave expression to the work of mathematicians and the professional image they sought to create for themselves, but how modernism also introduced deeper and ultimately unanswerable questions

  14. Energy-based ferromagnetic material model with magnetic anisotropy

    Energy Technology Data Exchange (ETDEWEB)

    Steentjes, Simon, E-mail: simon.steentjes@iem.rwth-aachen.de [Institute of Electrical Machines - RWTH Aachen University, Schinkelstr. 4, D-52056 Aachen (Germany); Henrotte, François, E-mail: francois.henrotte@uclouvain.be [Institute of Mechanics Materials and Civil Engineering - UCL, Av. G. Lemaître 4-6, B-1348 Louvain-la-Neuve (Belgium); Hameyer, Kay [Institute of Electrical Machines - RWTH Aachen University, Schinkelstr. 4, D-52056 Aachen (Germany)

    2017-03-01

    Non-oriented soft magnetic materials are commonly assumed to be magnetically isotropic. However, due to the rolling process a preferred direction exists along the rolling direction. This uniaxial magnetic anisotropy, and the related magnetostriction effect, are critical to the accurate calculation of iron losses and magnetic forces in rotating electrical machines. This paper proposes an extension of an isotropic energy-based vector hysteresis model to account for these two effects. - Highlights: • Energy-based vector hysteresis model with magnetic anisotropy. • Two-scale model to account for pinning field distribution. • Pinning force and reluctivity are extended to anisotropic case.

  15. A ghost fluid method for sharp interface simulations of compressible multiphase flows

    International Nuclear Information System (INIS)

    Majidi, Sahand; Afshari, Asghar

    2016-01-01

    A ghost fluid based computational tool is developed to study a wide range of compressible multiphase flows involving strong shocks and contact discontinuities while accounting for surface tension, viscous stresses and gravitational forces. The solver utilizes constrained reinitialization method to predict the interface configuration at each time step. Surface tension effect is handled via an exact interface Riemann problem solver. Interfacial viscous stresses are approximated by considering continuous velocity and viscous stress across the interface. To assess the performance of the solver several benchmark problems are considered: One-dimensional gas-water shock tube problem, shock-bubble interaction, air cavity collapse in water, underwater explosion, Rayleigh-Taylor Instability, and ellipsoidal drop oscillations. Results obtained from the numerical simulations indicate that the numerical methodology performs reasonably well in predicting flow features and exhibit a very good agreement with prior experimental and numerical observations. To further examine the accuracy of the developed ghost fluid solver, the obtained results are compared to those by a conventional diffuse interface solver. The comparison shows the capability of our ghost fluid method in reproducing the experimentally observed flow characteristics while revealing more details regarding topological changes of the interface.

  16. A ghost fluid method for sharp interface simulations of compressible multiphase flows

    Energy Technology Data Exchange (ETDEWEB)

    Majidi, Sahand; Afshari, Asghar [University of Tehran, Teheran (Iran, Islamic Republic of)

    2016-04-15

    A ghost fluid based computational tool is developed to study a wide range of compressible multiphase flows involving strong shocks and contact discontinuities while accounting for surface tension, viscous stresses and gravitational forces. The solver utilizes constrained reinitialization method to predict the interface configuration at each time step. Surface tension effect is handled via an exact interface Riemann problem solver. Interfacial viscous stresses are approximated by considering continuous velocity and viscous stress across the interface. To assess the performance of the solver several benchmark problems are considered: One-dimensional gas-water shock tube problem, shock-bubble interaction, air cavity collapse in water, underwater explosion, Rayleigh-Taylor Instability, and ellipsoidal drop oscillations. Results obtained from the numerical simulations indicate that the numerical methodology performs reasonably well in predicting flow features and exhibit a very good agreement with prior experimental and numerical observations. To further examine the accuracy of the developed ghost fluid solver, the obtained results are compared to those by a conventional diffuse interface solver. The comparison shows the capability of our ghost fluid method in reproducing the experimentally observed flow characteristics while revealing more details regarding topological changes of the interface.

  17. Ghost Remains After Black Hole Eruption

    Science.gov (United States)

    2009-05-01

    NASA's Chandra X-ray Observatory has found a cosmic "ghost" lurking around a distant supermassive black hole. This is the first detection of such a high-energy apparition, and scientists think it is evidence of a huge eruption produced by the black hole. This discovery presents astronomers with a valuable opportunity to observe phenomena that occurred when the Universe was very young. The X-ray ghost, so-called because a diffuse X-ray source has remained after other radiation from the outburst has died away, is in the Chandra Deep Field-North, one of the deepest X-ray images ever taken. The source, a.k.a. HDF 130, is over 10 billion light years away and existed at a time 3 billion years after the Big Bang, when galaxies and black holes were forming at a high rate. "We'd seen this fuzzy object a few years ago, but didn't realize until now that we were seeing a ghost", said Andy Fabian of the Cambridge University in the United Kingdom. "It's not out there to haunt us, rather it's telling us something - in this case what was happening in this galaxy billions of year ago." Fabian and colleagues think the X-ray glow from HDF 130 is evidence for a powerful outburst from its central black hole in the form of jets of energetic particles traveling at almost the speed of light. When the eruption was ongoing, it produced prodigious amounts of radio and X-radiation, but after several million years, the radio signal faded from view as the electrons radiated away their energy. HDF 130 Chandra X-ray Image of HDF 130 However, less energetic electrons can still produce X-rays by interacting with the pervasive sea of photons remaining from the Big Bang - the cosmic background radiation. Collisions between these electrons and the background photons can impart enough energy to the photons to boost them into the X-ray energy band. This process produces an extended X-ray source that lasts for another 30 million years or so. "This ghost tells us about the black hole's eruption long after

  18. Lensless ghost imaging through the strongly scattering medium

    International Nuclear Information System (INIS)

    Yang Zhe; Zhao Xueliang; Li Junlin; Zhao Lianjie; Qin Wei

    2016-01-01

    Lensless ghost imaging has attracted much interest in recent years due to its profound physics and potential applications. In this paper we report studies of the robust properties of the lensless ghost imaging system with a pseudo-thermal light source in a strongly scattering medium. The effects of the positions of the strong medium on the ghost imaging are investigated. In the lensless ghost imaging system, a pseudo-thermal light is split into two correlated beams by a beam splitter. One beam goes to a charge-coupled detector camera, labeled as CCD2. The other beam goes to an object and then is collected in another charge-coupled detector camera, labeled as CCD1, which serves as a bucket detector. When the strong medium, a pane of ground glass disk, is placed between the object and CCD1, the bucket detector, the quality of ghost imaging is barely affected and a good image could still be obtained. The quality of the ghost imaging can also be maintained, even when the ground glass is rotating, which is the strongest scattering medium so far. However, when the strongly scattering medium is present in the optical path from the light source to CCD2 or the object, the lensless ghost imaging system hardly retrieves the image of the object. A theoretical analysis in terms of the second-order correlation function is also provided. (paper)

  19. Ghost imaging with bucket detection and point detection

    Science.gov (United States)

    Zhang, De-Jian; Yin, Rao; Wang, Tong-Biao; Liao, Qing-Hua; Li, Hong-Guo; Liao, Qinghong; Liu, Jiang-Tao

    2018-04-01

    We experimentally investigate ghost imaging with bucket detection and point detection in which three types of illuminating sources are applied: (a) pseudo-thermal light source; (b) amplitude modulated true thermal light source; (c) amplitude modulated laser source. Experimental results show that the quality of ghost images reconstructed with true thermal light or laser beam is insensitive to the usage of bucket or point detector, however, the quality of ghost images reconstructed with pseudo-thermal light in bucket detector case is better than that in point detector case. Our theoretical analysis shows that the reason for this is due to the first order transverse coherence of the illuminating source.

  20. Vertex operator construction of superconformal ghosts and string field theory

    International Nuclear Information System (INIS)

    Ezawa, Z.F.; Nakamura, S.; Tezuka, A.

    1987-01-01

    Superconformal ghosts in string theories are characterized by the SU(1,1) Kac-Moody algebra with central charge -1/2. These ghost fields are constructed as the vertex operators realizing spinor representations of the Kac-Moody algebra. Representations of the canonical commutation relations of the superconformal ghosts are analyzed extensively. All irreducible representations are found to possess only the trivial inner product but for one exceptional case. Consequently, in superstring field theory it is necessary to consider reducible representations in general. Hilbert spaces with a non-trivial inner product are explicitly obtained upon which second quantization of superstring may be carried out. (orig.)

  1. Ghost neutrinos as test fields in curved space-time

    International Nuclear Information System (INIS)

    Audretsch, J.

    1976-01-01

    Without restricting to empty space-times, it is shown that ghost neutrinos (their energy-momentum tensor vanishes) can only be found in algebraically special space-times with a neutrino flux vector parallel to one of the principal null vectors of the conformal tensor. The optical properties are studied. There are no ghost neutrinos in the Kerr-Newman and in spherically symmetric space-times. The example of a non-vacuum gravitational pp-wave accompanied by a ghost neutrino pp-wave is discussed. (Auth.)

  2. Defocusing effects of lensless ghost imaging and ghost diffraction with partially coherent sources

    Science.gov (United States)

    Zhou, Shuang-Xi; Sheng, Wei; Bi, Yu-Bo; Luo, Chun-Ling

    2018-04-01

    The defocusing effect is inevitable and degrades the image quality in the conventional optical imaging process significantly due to the close confinement of the imaging lens. Based on classical optical coherent theory and linear algebra, we develop a unified formula to describe the defocusing effects of both lensless ghost imaging (LGI) and lensless ghost diffraction (LGD) systems with a partially coherent source. Numerical examples are given to illustrate the influence of defocusing length on the quality of LGI and LGD. We find that the defocusing effects of the test and reference paths in the LGI or LGD systems are entirely different, while the LGD system is more robust against defocusing than the LGI system. Specifically, we find that the imaging process for LGD systems can be viewed as pinhole imaging, which may find applications in ultra-short-wave band imaging without imaging lenses, e.g. x-ray diffraction and γ-ray imaging.

  3. Exorcising the ghost of the Sputnik crisis.

    Science.gov (United States)

    Kolberg, Espen Skarstein; Holt, Heidi Marie; Klevan, Ingvild

    2017-10-01

    Drug calculation is not immune to the undesirable impact of math anxiety and negative attitudes on test outcomes in nursing studies, and several studies indicate that math anxiety is present in the student population at such a degree that it is likely to interfere with these students' mathematical ability. Examining the educational system through the lens of history and adding a dash of cultural theory, a contributing cause to the math anxiety may be found in the Sputnik Crisis of the late 1950s, the ghostly remnants of which are still present in the stereotypes of mathematics promoted by mass media. In an effort to reshape the culturally conditioned attitudes which may be responsible for math anxiety, we suggest using elements from popular culture to diversify the perception and image of mathematics in drug calculation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Testing the ghost with the machine

    International Nuclear Information System (INIS)

    De Zubicaray, G.

    2002-01-01

    Since its introduction during the 1990s, functional magnetic resonance imaging (fMRI) has been used to investigate brain activity occurring during a bewildering variety of sensory, motor and cognitive tasks. That is, a machine is being used to test 'the ghost in the machine' - the human mind. The use of imaging techniques to investigate these issues has even led to the emergence of a new scientific field called cognitive neuroscience. Currently, there are only a few groups in Australia actively publishing fMRI studies in the international literature, and the majority of these laboratories are clustered on the east coast. My own research with fMRI has focused on areas such as language and memory, with a special interest in how we solve competitive processes in our thinking

  5. Computational ghost imaging using deep learning

    Science.gov (United States)

    Shimobaba, Tomoyoshi; Endo, Yutaka; Nishitsuji, Takashi; Takahashi, Takayuki; Nagahama, Yuki; Hasegawa, Satoki; Sano, Marie; Hirayama, Ryuji; Kakue, Takashi; Shiraki, Atsushi; Ito, Tomoyoshi

    2018-04-01

    Computational ghost imaging (CGI) is a single-pixel imaging technique that exploits the correlation between known random patterns and the measured intensity of light transmitted (or reflected) by an object. Although CGI can obtain two- or three-dimensional images with a single or a few bucket detectors, the quality of the reconstructed images is reduced by noise due to the reconstruction of images from random patterns. In this study, we improve the quality of CGI images using deep learning. A deep neural network is used to automatically learn the features of noise-contaminated CGI images. After training, the network is able to predict low-noise images from new noise-contaminated CGI images.

  6. Correspondence normalized ghost imaging on compressive sensing

    International Nuclear Information System (INIS)

    Zhao Sheng-Mei; Zhuang Peng

    2014-01-01

    Ghost imaging (GI) offers great potential with respect to conventional imaging techniques. It is an open problem in GI systems that a long acquisition time is be required for reconstructing images with good visibility and signal-to-noise ratios (SNRs). In this paper, we propose a new scheme to get good performance with a shorter construction time. We call it correspondence normalized ghost imaging based on compressive sensing (CCNGI). In the scheme, we enhance the signal-to-noise performance by normalizing the reference beam intensity to eliminate the noise caused by laser power fluctuations, and reduce the reconstruction time by using both compressive sensing (CS) and time-correspondence imaging (CI) techniques. It is shown that the qualities of the images have been improved and the reconstruction time has been reduced using CCNGI scheme. For the two-grayscale ''double-slit'' image, the mean square error (MSE) by GI and the normalized GI (NGI) schemes with the measurement number of 5000 are 0.237 and 0.164, respectively, and that is 0.021 by CCNGI scheme with 2500 measurements. For the eight-grayscale ''lena'' object, the peak signal-to-noise rates (PSNRs) are 10.506 and 13.098, respectively using GI and NGI schemes while the value turns to 16.198 using CCNGI scheme. The results also show that a high-fidelity GI reconstruction has been achieved using only 44% of the number of measurements corresponding to the Nyquist limit for the two-grayscale “double-slit'' object. The qualities of the reconstructed images using CCNGI are almost the same as those from GI via sparsity constraints (GISC) with a shorter reconstruction time. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  7. The Ghosts of Acetylcholine : structure-activity relationships of ...

    African Journals Online (AJOL)

    The Ghosts of Acetylcholine : structure-activity relationships of muscle relaxants : registrar communication. ... AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's ...

  8. Half-integer ghost states and simple BRST quantization

    International Nuclear Information System (INIS)

    Marnelius, R.

    1987-01-01

    Quantum mechanical BRST systems are considered. As is well known an odd number of ghost operators has a representation with respect to the ghost number operator consisting of states with half-integer ghost numbers. Here it is shown that an eigenstate representation of the ghost operators requires a particular mixed Grassmann character of the states. It is also shown that such states always may be avoided provided only one starts from a lagrangian where the fundamental constraints are generated by Lagrange multipliers. In the latter case there also exists an anti-BRST charge. Some relevant properties of the different BRST approaches are displayed. The existence of inequivalent physical representations is demonstrated. (orig.)

  9. The b ghost of the pure spinor formalism is nilpotent

    Energy Technology Data Exchange (ETDEWEB)

    Chandia, Osvaldo, E-mail: osvaldo.chandia@uai.c [Departamento de Ciencias, Facultad de Artes Liberales and Facultad de Ingenieria y Ciencias, Universidad Adolfo Ibanez, Santiago (Chile)

    2011-01-10

    The ghost for world-sheet reparametrization invariance is not a fundamental field in the pure spinor formalism. It is written as a combination of pure spinor variables which have conformal dimension two and such that it commutes with the BRST operator to give the world-sheet stress tensor. We show that the ghost variable defined in this way is nilpotent since the OPE of b with itself does not have singularities.

  10. Publication ethics and the ghost management of medical publication.

    Science.gov (United States)

    Sismondo, Sergio; Doucet, Mathieu

    2010-07-01

    It is by now no secret that some scientific articles are ghost authored - that is, written by someone other than the person whose name appears at the top of the article. Ghost authorship, however, is only one sort of ghosting. In this article, we present evidence that pharmaceutical companies engage in the ghost management of the scientific literature, by controlling or shaping several crucial steps in the research, writing, and publication of scientific articles. Ghost management allows the pharmaceutical industry to shape the literature in ways that serve its interests. This article aims to reinforce and expand publication ethics as an important area of concern for bioethics. Since ghost-managed research is primarily undertaken in the interests of marketing, large quantities of medical research violate not just publication norms but also research ethics. Much of this research involves human subjects, and yet is performed not primarily to increase knowledge for broad human benefit, but to disseminate results in the service of profits. Those who sponsor, manage, conduct, and publish such research therefore behave unethically, since they put patients at risk without justification. This leads us to a strong conclusion: if medical journals want to ensure that the research they publish is ethically sound, they should not publish articles that are commercially sponsored.

  11. Infrared Behavior of Gluon and Ghost Propagators in Landau Gauge QCD

    International Nuclear Information System (INIS)

    von Smekal, L.; Hauck, A.; Alkofer, R.

    1997-01-01

    A truncation scheme for the Dyson-Schwinger equations of Euclidean QCD in Landau gauge is presented. It implements the Slavnov-Taylor identities for the three-gluon and ghost-gluon vertices, whereas irreducible four-gluon couplings as well as the gluon-ghost and ghost-ghost scattering kernels are neglected. The infrared behavior of gluon and ghost propagators is obtained analytically: The gluon propagator vanishes for small momenta, whereas the ghost propagator diverges strongly. The numerical solutions are compared with recent lattice results. The running coupling approaches a fixed point, α c ≅9.5 , in the infrared. copyright 1997 The American Physical Society

  12. An Improved Ghost-cell Immersed Boundary Method for Compressible Inviscid Flow Simulations

    KAUST Repository

    Chi, Cheng

    2015-01-01

    This study presents an improved ghost-cell immersed boundary approach to represent a solid body in compressible flow simulations. In contrast to the commonly used approaches, in the present work ghost cells are mirrored through the boundary

  13. An improved ghost-cell immersed boundary method for compressible flow simulations

    KAUST Repository

    Chi, Cheng; Lee, Bok Jik; Im, Hong G.

    2016-01-01

    This study presents an improved ghost-cell immersed boundary approach to represent a solid body in compressible flow simulations. In contrast to the commonly used approaches, in the present work ghost cells are mirrored through the boundary

  14. Ghost suppression in image restoration filtering

    Science.gov (United States)

    Riemer, T. E.; Mcgillem, C. D.

    1975-01-01

    An optimum image restoration filter is described in which provision is made to constrain the spatial extent of the restoration function, the noise level of the filter output and the rate of falloff of the composite system point-spread away from the origin. Experimental results show that sidelobes on the composite system point-spread function produce ghosts in the restored image near discontinuities in intensity level. By redetermining the filter using a penalty function that is zero over the main lobe of the composite point-spread function of the optimum filter and nonzero where the point-spread function departs from a smoothly decaying function in the sidelobe region, a great reduction in sidelobe level is obtained. Almost no loss in resolving power of the composite system results from this procedure. By iteratively carrying out the same procedure even further reductions in sidelobe level are obtained. Examples of original and iterated restoration functions are shown along with their effects on a test image.

  15. Short term depression unmasks the ghost frequency.

    Directory of Open Access Journals (Sweden)

    Tjeerd V Olde Scheper

    Full Text Available Short Term Plasticity (STP has been shown to exist extensively in synapses throughout the brain. Its function is more or less clear in the sense that it alters the probability of synaptic transmission at short time scales. However, it is still unclear what effect STP has on the dynamics of neural networks. We show, using a novel dynamic STP model, that Short Term Depression (STD can affect the phase of frequency coded input such that small networks can perform temporal signal summation and determination with high accuracy. We show that this property of STD can readily solve the problem of the ghost frequency, the perceived pitch of a harmonic complex in absence of the base frequency. Additionally, we demonstrate that this property can explain dynamics in larger networks. By means of two models, one of chopper neurons in the Ventral Cochlear Nucleus and one of a cortical microcircuit with inhibitory Martinotti neurons, it is shown that the dynamics in these microcircuits can reliably be reproduced using STP. Our model of STP gives important insights into the potential roles of STP in self-regulation of cortical activity and long-range afferent input in neuronal microcircuits.

  16. Evidence of ghost suppression in gluon mass scale dynamics

    Science.gov (United States)

    Aguilar, A. C.; Binosi, D.; Figueiredo, C. T.; Papavassiliou, J.

    2018-03-01

    In this work we study the impact that the ghost sector of pure Yang-Mills theories may have on the generation of a dynamical gauge boson mass scale, which hinges on the appearance of massless poles in the fundamental vertices of the theory, and the subsequent realization of the well-known Schwinger mechanism. The process responsible for the formation of such structures is itself dynamical in nature, and is governed by a set of Bethe-Salpeter type of integral equations. While in previous studies the presence of massless poles was assumed to be exclusively associated with the background-gauge three-gluon vertex, in the present analysis we allow them to appear also in the corresponding ghost-gluon vertex. The full analysis of the resulting Bethe-Salpeter system reveals that the contribution of the poles associated with the ghost-gluon vertex are particularly suppressed, their sole discernible effect being a slight modification in the running of the gluon mass scale, for momenta larger than a few GeV. In addition, we examine the behavior of the (background-gauge) ghost-gluon vertex in the limit of vanishing ghost momentum, and derive the corresponding version of Taylor's theorem. These considerations, together with a suitable Ansatz, permit us the full reconstruction of the pole sector of the two vertices involved.

  17. CLONING HARDDISK MELALUI JARINGAN KOMPUTER DENGAN MENGGUNAKAN SOFTWARE GHOST

    Directory of Open Access Journals (Sweden)

    M Mufadhol

    2009-07-01

    Full Text Available Kloning adalah proses duplikat isi harddisk ke harddisk yang lain. Jadi isi kedua harddisk adalah sama persis. Kloning harddisk dilakukan untuk mempercepat proses instalasi perangkat lunak dengan spesifikasi hardware yang sama. Kloning harddisk melalui jaringan komputer dapat dilakukan dari harddisk master ke harddisk slave atau harddisk tujuan. Pada proses kloning harddisk melalui jaringan komputer hardis induk berada di komputer server saja sedangkan slave harddisk berada di komputer klien saja. Harddisk setiap komputer tidak perlu digandeng (diparalel. Dalam melakukan kloning harddisk melalui jaringan komputer diperlukan beberapa program aplikasi antara lain: Ghost Cast Server, Boot Wizard, LAN Boot Floppy Klien, Ghost Explore. Aplikasi yang sering digunakan untuk kloning adalah software Ghost yang dirilis oleh Symantect Coorporation.

  18. Ghost free dual vector theories in 2+1 dimensions

    International Nuclear Information System (INIS)

    Dalmazi, Denis

    2006-01-01

    We explore here the issue of duality versus spectrum equivalence in dual theories generated through the master action approach. Specifically we examine a generalized self-dual (GSD) model where a Maxwell term is added to the self-dual model. A gauge embedding procedure applied to the GSD model leads to a Maxwell-Chern-Simons (MCS) theory with higher derivatives. We show here that the latter contains a ghost mode contrary to the original GSD model. By figuring out the origin of the ghost we are able to suggest a new master action which interpolates between the local GSD model and a nonlocal MCS model. Those models share the same spectrum and are ghost free. Furthermore, there is a dual map between both theories at classical level which survives quantum correlation functions up to contact terms. The remarks made here may be relevant for other applications of the master action approach

  19. Modelling of classical ghost images obtained using scattered light

    International Nuclear Information System (INIS)

    Crosby, S; Castelletto, S; Aruldoss, C; Scholten, R E; Roberts, A

    2007-01-01

    The images obtained in ghost imaging with pseudo-thermal light sources are highly dependent on the spatial coherence properties of the incident light. Pseudo-thermal light is often created by reducing the coherence length of a coherent source by passing it through a turbid mixture of scattering spheres. We describe a model for simulating ghost images obtained with such partially coherent light, using a wave-transport model to calculate the influence of the scattering on initially coherent light. The model is able to predict important properties of the pseudo-thermal source, such as the coherence length and the amplitude of the residual unscattered component of the light which influence the resolution and visibility of the final ghost image. We show that the residual ballistic component introduces an additional background in the reconstructed image, and the spatial resolution obtainable depends on the size of the scattering spheres

  20. Ghost anomalous dimension in asymptotically safe quantum gravity

    International Nuclear Information System (INIS)

    Eichhorn, Astrid; Gies, Holger

    2010-01-01

    We compute the ghost anomalous dimension within the asymptotic-safety scenario for quantum gravity. For a class of covariant gauge fixings and using a functional renormalization group scheme, the anomalous dimension η c is negative, implying an improved UV behavior of ghost fluctuations. At the non-Gaussian UV fixed point, we observe a maximum value of η c ≅-0.78 for the Landau-deWitt gauge within the given scheme and truncation. Most importantly, the backreaction of the ghost flow onto the Einstein-Hilbert sector preserves the non-Gaussian fixed point with only mild modifications of the fixed-point values for the gravitational coupling and cosmological constant and the associated critical exponents; also their gauge dependence is slightly reduced. Our results provide further evidence for the asymptotic-safety scenario of quantum gravity.

  1. Ombud’s corner: Do you believe in ghosts?

    CERN Multimedia

    Sudeshna Datta-Cockerill

    2014-01-01

    “Ghosting” is the common term used to describe situations when a piece of work is done by somebody but credited to somebody else. Ghosting often occurs in creative fields, such as writing texts, music, developing graphic charters or translating. Let’s celebrate Halloween this year by acknowledging the contributions of all the CERN ghosts who work tirelessly behind the scenes in all areas of the Organization.   “Ghosting” is a recognised job with international professional associations, particularly in the field of text writing. The role requires strict anonymity, good reciprocal trust and understanding between the people involved, and the professional flexibility to be able to adapt to different situations and different styles of expression as needed. At CERN there are many ghosts: you can find them in the Translation and Minute-writing service, whose members also provide valuable editing and proof-reading skills; in the Communications group w...

  2. The Ghost Tradition: Helen Of Troy In The Elizabethan Era

    Directory of Open Access Journals (Sweden)

    RADUCANU ADRIANA

    2014-12-01

    Full Text Available Reputedly the most beautiful woman who has ever lived, Helen of Troy (or Sparta is less well known for her elusive, ghost-like dimension. Homer wrote that the greatest war of Western classical antiquity started because of Helen's adultery followed by her elopement to Troy. Other ancient writers and historians, among theme Aeschylus, Stesichorus, Hesiod, Pausanias, Aristophanes, Euripides and Gorgias of Leontini, challenged the Homeric version, in various ways and attempted to exonerate Helen either by focusing on her phantom/ ghost/ as the generic object of man's desire and scorn or by casting doubt on the mechanisms of the blaming process. This paper argues that the Elizabethans Christopher Marlowe and William Shakespeare adopted and adapted the anti-Homer version of the depiction of Helen, what I here call “the ancient Helen ghost tradition”; nevertheless, in so doing they further reinforced the character's demonic features and paradoxically achieved a return to the adulterous Homeric Helen.

  3. Non-perturbative power corrections to ghost and gluon propagators

    International Nuclear Information System (INIS)

    Boucaud, Philippe; Leroy, Jean-Pierre; Yaouanc, Alain Le; Lokhov, Alexey; Micheli, Jacques; Pene, Olivier; RodrIguez-Quintero, Jose; Roiesnel, Claude

    2006-01-01

    We study the dominant non-perturbative power corrections to the ghost and gluon propagators in Landau gauge pure Yang-Mills theory using OPE and lattice simulations. The leading order Wilson coefficients are proven to be the same for both propagators. The ratio of the ghost and gluon propagators is thus free from this dominant power correction. Indeed, a purely perturbative fit of this ratio gives smaller value ( ≅ 270MeV) of Λ M-barS-bar than the one obtained from the propagators separately( ≅ 320MeV). This argues in favour of significant non-perturbative ∼ 1/q 2 power corrections in the ghost and gluon propagators. We check the self-consistency of the method

  4. Modelling of classical ghost images obtained using scattered light

    Energy Technology Data Exchange (ETDEWEB)

    Crosby, S; Castelletto, S; Aruldoss, C; Scholten, R E; Roberts, A [School of Physics, University of Melbourne, Victoria, 3010 (Australia)

    2007-08-15

    The images obtained in ghost imaging with pseudo-thermal light sources are highly dependent on the spatial coherence properties of the incident light. Pseudo-thermal light is often created by reducing the coherence length of a coherent source by passing it through a turbid mixture of scattering spheres. We describe a model for simulating ghost images obtained with such partially coherent light, using a wave-transport model to calculate the influence of the scattering on initially coherent light. The model is able to predict important properties of the pseudo-thermal source, such as the coherence length and the amplitude of the residual unscattered component of the light which influence the resolution and visibility of the final ghost image. We show that the residual ballistic component introduces an additional background in the reconstructed image, and the spatial resolution obtainable depends on the size of the scattering spheres.

  5. Ghost-free, finite, fourth-order D = 3 gravity.

    Science.gov (United States)

    Deser, S

    2009-09-04

    Canonical analysis of a recently proposed linear + quadratic curvature gravity model in D = 3 establishes its pure, irreducibly fourth derivative, quadratic curvature limit as both ghost-free and power-counting UV finite, thereby maximally violating standard folklore. This limit is representative of a generic class whose kinetic terms are conformally invariant in any dimension, but it is unique in simultaneously avoiding the transverse-traceless graviton ghosts plaguing D > 3 quadratic actions as well as double pole propagators in its other variables. While the two-term model is also unitary, its additional mode's second-derivative nature forfeits finiteness.

  6. Ghost responses of the FitzHugh–Nagumo system induced by colored noise

    International Nuclear Information System (INIS)

    Bordet, M.; Morfu, S.; Marquié, P.

    2015-01-01

    We investigate both numerically and experimentally how the triggering of Ghost Stochastic Resonance is affected by colored noise in a FitzHugh–Nagumo circuit. It is experimentally shown that when the circuit is excited with a bichromatic signal, weak colored noise can induce a response with a main ghost frequency which is not present in the excitation. We analyze the occurrence of this ghost frequency versus the noise intensity and the correlation time of the colored noise. Numerical simulations and experiments confirm that for larger noise correlation time, submultiples of this ghost frequency dominate the system response while the previous expected ghost frequency is less observed

  7. Weyl and ghost number anomalies in the Polyakov's light-cone gauge

    International Nuclear Information System (INIS)

    Suzuki, H.

    1991-01-01

    In this paper the conformal (Weyl) anomaly of the ghost-anti-ghost system in the 2-dimensional quantum gravity is calculated. A background covariant formalism allows us to treat the Polyakov's light-cone gauge in a systematic way. The anomaly gives a contribution to the central charge, -28, which agrees with the result of Kniznik, Polyakov, and Zamolodchikov. The ghost number anomaly is also calculated, and the metric corrections to the naive ghost number current are given. It is suggested that a general scalar density in the light-cone gauge carries a screening ghost number

  8. Theoretical scheme of thermal-light many-ghost imaging by Nth-order intensity correlation

    International Nuclear Information System (INIS)

    Liu Yingchuan; Kuang Leman

    2011-01-01

    In this paper, we propose a theoretical scheme of many-ghost imaging in terms of Nth-order correlated thermal light. We obtain the Gaussian thin lens equations in the many-ghost imaging protocol. We show that it is possible to produce N-1 ghost images of an object at different places in a nonlocal fashion by means of a higher order correlated imaging process with an Nth-order correlated thermal source and correlation measurements. We investigate the visibility of the ghost images in the scheme and obtain the upper bounds of the visibility for the Nth-order correlated thermal-light ghost imaging. It is found that the visibility of the ghost images can be dramatically enhanced when the order of correlation becomes larger. It is pointed out that the many-ghost imaging phenomenon is an observable physical effect induced by higher order coherence or higher order correlations of optical fields.

  9. Harriot, Digges, and the Ghost in Hamlet.

    Science.gov (United States)

    Usher, P. D.

    1998-12-01

    The cosmic allegorical interpretation of Hamlet (BAAS 28, 1305, 1996; 29, 1262, 1997; Giornale di Astronomia 24:3, 27, 1998) may be regarded as a Galilean postulatum with testable consequences. It associates leading characters in the play with cosmologists from the time of Ptolemy (Claudius) to Tycho Brahe (Rosencrantz and Guildenstern) and Thomas Digges (Hamlet). Lines 3.3.8-23 describe how the concepts of geocentricism and the sphere of fixed stars shared by the Ptolemaic and Tychonic models are imperiled by the Infinite Universe of Digges. Hitherto baffling lines 5.2.100-125 list in short order at least 16 attributes of Thomas Harriot, including his short bibliography (``soul of great article'') which may explain why he receives mention only in passing. The Ghost is Thomas Digges' father Leonard, who is a ``mole'' in the ``cellarage.'' That Leonard may have gone underground following restoration of his lands is supported by the range of years (1559-1574) of his alleged death, and conspicuous absence of a gravesite. Circumstances of his disappearance have remained mysterious (N&Q 2:X, 162, 1860; 6:X, 368, 515, 1884; 8:V, 186, 1894.) I suggest that, having been saved from execution and restored to gentility, he continued to work, writing in the tradition of his confrere's father Thomas Wyatt, Sr. who pioneered the English sonnet. The first Dowden series of sonnets reflects his love for his only child. The history of the perspective glass explains lines in Sonnets 14 and 103 (``my blunt invention'') and in the I.M.S. encomium wherein he did ``rowle back the heavens'' with a ``cleere and equall surface'' that is ``reflecting ages past.'' A portrait of Tycho helps date Sonnet 16 to between 1581 and 1585. Sonnets 18 and 87 would date to 1583 and 1595. Allusions to old age are not surprising. I.M.'s words: ``Wee wondred (Shake-speare) that thou went'st so soone'' and ``An Actors Art, can dye, and liue to acte a second part'' are explained, as are sources for The

  10. Elimination of ghost markers during dual sensor-based infrared tracking of multiple individual reflective markers

    International Nuclear Information System (INIS)

    Stroian, G.; Falco, T.; Seuntjens, J.P.

    2004-01-01

    The accuracy of dose delivery in radiotherapy is affected by the uncertainty in tumor localization. Motion of internal anatomy due to physiological processes such as respiration may lead to significant displacements which compromise tumor coverage and generate irradiation of healthy tissue. Real-time tracking with infrared-based systems is often used for tracking thoracic motion in radiation therapy. We studied the origin of ghost markers ('crosstalk') which may appear during dual sensor-based infrared tracking of independent reflective markers. Ghost markers occur when two or more reflective markers are coplanar with each other and with the sensors of the two camera-based infrared tracking system. Analysis shows that sensors are not points but they have a finite extent and this extent determines for each marker a 'ghost volume'. If one reflective marker enters the ghost volume of another marker, ghost markers will be reported by the tracking system; if the reflective markers belong to a surface their 'ghost volume' is reduced to a 'ghost surface' (ghost zone). Appearance of ghost markers is predicted for markers taped on the torso of an anthropomorphic phantom. This study illustrates the dependence of the shape, extent, and location of the ghost zones on the shape of the anthropomorphic phantom, the angle of view of the tracking system, and the distance between the tracking system and the anthropomorphic phantom. It is concluded that the appearance of ghost markers can be avoided by positioning the markers outside the ghost zones of the other markers. However, if this is not possible and the initial marker configuration is ghost marker-free, ghost markers can be eliminated during real-time tracking by virtue of the fact that they appear in the coordinate data sequence only temporarily

  11. Suppressing Ghost Diffraction in E-Beam-Written Gratings

    Science.gov (United States)

    Wilson, Daniel; Backlund, Johan

    2009-01-01

    A modified scheme for electron-beam (E-beam) writing used in the fabrication of convex or concave diffraction gratings makes it possible to suppress the ghost diffraction heretofore exhibited by such gratings. Ghost diffraction is a spurious component of diffraction caused by a spurious component of grating periodicity as described below. The ghost diffraction orders appear between the main diffraction orders and are typically more intense than is the diffuse scattering from the grating. At such high intensity, ghost diffraction is the dominant source of degradation of grating performance. The pattern of a convex or concave grating is established by electron-beam writing in a resist material coating a substrate that has the desired convex or concave shape. Unfortunately, as a result of the characteristics of electrostatic deflectors used to control the electron beam, it is possible to expose only a small field - typically between 0.5 and 1.0 mm wide - at a given fixed position of the electron gun relative to the substrate. To make a grating larger than the field size, it is necessary to move the substrate to make it possible to write fields centered at different positions, so that the larger area is synthesized by "stitching" the exposed fields.

  12. Teen Girls' Resistance and the Disappearing Social in "Ghost World."

    Science.gov (United States)

    Giroux, Henry A.

    2002-01-01

    Examines "Ghost World," a Hollywood film about youth, friendship, alienation, and survival, critically investigating how popular representations of youth signal a particular crisis of the social through a discourse of privatization, which fails to locate youth and problems they face within the related geographies of the social and political. The…

  13. Ghost crabs on a treadmill: Oxygen Uptake and Haemocyanin ...

    African Journals Online (AJOL)

    Ghost crabs Ocypode ceratophthalmus were exercised on a specially constructed treadmill. At a running speed of 13,3 cm s-1, most crabs ran for 2 h before getting fatigued. At this speed the oxygen consumption rate (MO2) was measured in time intervals for a total of 52 min. For exercised crabs the MO2 values are about ...

  14. Cinematography in Motherhood: a Hong Kong film adaptation of Ghosts

    Directory of Open Access Journals (Sweden)

    Kwok-kan Tam

    2015-02-01

    Full Text Available This is a study of a Hong Kong Chinese film adaptation of Ghosts made in 1960. It deals with processes of cross-cultural and cross-media adaptation, and probes issues of how stage techniques are turned into cinematographic devices. Ibsen’s plays, except Ghosts, have been adapted numerous times for the Chinese stage and screen in Hong Kong and China. Unlike in China, the reception of Ibsen in Hong Kong is not meant for political purposes. In most Hong Kong adaptations, Ibsen is valued for the purpose of theatrical experimentation. Among the stage adaptations, A Doll’s House and The Master Builder are the most popular. However, there was a film adaptation of Ghosts in 1960, which has never been discussed in Ibsen scholarship. In this adaptation, Director Tso Kea borrowed the plot from Ghosts and made a perfect Chinese melodrama film highlighting the Chinese emotions and relations in a wealthy family that undergoes a crisis. In traditional Chinese drama, there is the lack of psychological rendering in characterization and characters act according to moral considerations. In Tso Kea’s film, the portrayal of the mother provides a new sense of characterization by combining Mrs Alving with the traditional Chinese mother figure. The borrowing from Ibsen makes it possible for the Chinese film to create a character with emotional and psychological complexities. Images from the film are selected as illustration in the article.

  15. Ghost fringe removal techniques using Lissajous data presentation.

    Science.gov (United States)

    Erskine, David J; Eggert, J H; Celliers, P M; Hicks, D G

    2016-03-01

    A VISAR (Velocity Interferometer System for Any Reflector) is a Doppler velocity interferometer which is an important optical diagnostic in shockwave experiments at the national laboratories, used to measure equation of state (EOS) of materials under extreme conditions. Unwanted reflection of laser light from target windows can produce an additional component to the VISAR fringe record that can distort and obscure the true velocity signal. Accurately removing this so-called ghost artifact component is essential for achieving high accuracy EOS measurements, especially when the true light signal is only weakly reflected from the shock front. Independent of the choice of algorithm for processing the raw data into a complex fringe signal, we have found it beneficial to plot this signal as a Lissajous and seek the proper center of this path, even under time varying intensity which can shift the perceived center. The ghost contribution is then solved by a simple translation in the complex plane that recenters the Lissajous path. For continuous velocity histories, we find that plotting the fringe magnitude vs nonfringing intensity and optimizing linearity is an invaluable tool for determining accurate ghost offsets. For discontinuous velocity histories, we have developed graphically inspired methods which relate the results of two VISARs having different velocity per fringe proportionalities or assumptions of constant fringe magnitude to find the ghost offset. The technique can also remove window reflection artifacts in generic interferometers, such as in the metrology of surfaces.

  16. AXAF-I ghost ray study: On orbit case

    Science.gov (United States)

    Gaetz, T. J.

    1993-01-01

    The problem of baffles for control of singly reflected (and nonreflected) ghost rays is considered. The theory of baffle design for Wolter Type I grazing incidence optics is reviewed, and a set of sample baffle parameters is obtained subject to the assumptions of nominal mirror figures and perfect manufacture and alignment of baffles. It is found that baffles forward of the optics (in the thermal precollimator) and between the mirror elements (at the CAP) are sufficient to allow the simultaneous ghost image and vignetting requirements to be satisfied for HRMA shells P1H1, P3H3, and P4H4. However, these baffles are not sufficient for the innermost shell P6H6; at best the requirements are slightly violated and there is no margin for tolerances. The addition of a baffle interior to the P6 space at an axial station about one third of the way forward from the aft end of the paraboloid will allow the ghost ray and vignetting requirements to be met. The minimum ghost ray angles and the vignetting angles are sensitive functions of the baffle positions and radii; tolerances of considerably better than 1 mm will be required. The sensitivities are coupled and correlated; further investigations should be undertaken in order to obtain baffle parameters which, combined with likely achievable tolerances, will minimize the risk of the vignetting/ghost ray requirements not being met. The lightweight carbon-epoxy composite used for thermal baffles has insufficient X-ray opacity to be a suitable material for construction of the controlling X-ray baffles; further study is needed to determine an appropriate material and to investigate its thermal and mechanical implications.

  17. Ghost imaging and ghost diffraction with pseudo-thermal light generated by means of a programmable SLM

    International Nuclear Information System (INIS)

    Capeluto, M G; Schmiegelow, C T; Francisco, D; Ledesma, S; Iemmi, C; Duisterwinkel, H

    2011-01-01

    Ghost imaging and ghost diffraction are techniques in which information about the object or about its diffraction pattern is extracted by measuring the correlation between a reference beam and a beam that passes through the object. Although first experiments were carried on by using entangled photons, it was demonstrated that this technique can be performed by splitting incoherent pseudo-thermal radiation such as that obtained with a laser passing through a moving diffuser. In this work we implemented the use of a programmable phase spatial light modulator (SLM) in order to replace the rotating ground glass. In this way the random phase distributions obtained from the moving diffuser can be emulated by displaying onto the SLM different realizations of a random function with uniform distribution. Based on the programmability of the modulator we have studied the influence of diverse parameters such as speckle size or phase distributions in the final image quality. We carry on the experiment for two different cases ghost imaging and far field ghost diffraction.

  18. Comparison of the signal-to-noise characteristics of quantum versus thermal ghost imaging

    International Nuclear Information System (INIS)

    O'Sullivan, Malcolm N.; Chan, Kam Wai Clifford; Boyd, Robert W.

    2010-01-01

    We present a theoretical comparison of the signal-to-noise characteristics of quantum versus thermal ghost imaging. We first calculate the signal-to-noise ratio of each process in terms of its controllable experimental conditions. We show that a key distinction is that a thermal ghost image always resides on top of a large background; the fluctuations in this background constitutes an intrinsic noise source for thermal ghost imaging. In contrast, there is a negligible intrinsic background to a quantum ghost image. However, for practical reasons involving achievable illumination levels, acquisition times for thermal ghost images are often much shorter than those for quantum ghost images. We provide quantitative predictions for the conditions under which each process provides superior performance. Our conclusion is that each process can provide useful functionality, although under complementary conditions.

  19. Masslessness of ghosts in equivariantly gauge-fixed Yang-Mills theories

    International Nuclear Information System (INIS)

    Golterman, Maarten; Zimmerman, Leah

    2005-01-01

    We show that the one-loop ghost self-energy in an equivariantly gauge-fixed Yang-Mills theory vanishes at zero momentum. A ghost mass is forbidden by equivariant BRST symmetry, and our calculation confirms this explicitly. The four-ghost self interaction which appears in the equivariantly gauge-fixed Yang-Mills theory is needed in order to obtain this result

  20. Long-distance thermal temporal ghost imaging over optical fibers

    Science.gov (United States)

    Yao, Xin; Zhang, Wei; Li, Hao; You, Lixing; Wang, Zhen; Huang, Yidong

    2018-02-01

    A thermal ghost imaging scheme between two distant parties is proposed and experimentally demonstrated over long-distance optical fibers. In the scheme, the weak thermal light is split into two paths. Photons in one path are spatially diffused according to their frequencies by a spatial dispersion component, then illuminate the object and record its spatial transmission information. Photons in the other path are temporally diffused by a temporal dispersion component. By the coincidence measurement between photons of two paths, the object can be imaged in a way of ghost imaging, based on the frequency correlation between photons in the two paths. In the experiment, the weak thermal light source is prepared by the spontaneous four-wave mixing in a silicon waveguide. The temporal dispersion is introduced by single mode fibers of 50 km, which also could be looked as a fiber link. Experimental results show that this scheme can be realized over long-distance optical fibers.

  1. Pseudo color ghost coding imaging with pseudo thermal light

    Science.gov (United States)

    Duan, De-yang; Xia, Yun-jie

    2018-04-01

    We present a new pseudo color imaging scheme named pseudo color ghost coding imaging based on ghost imaging but with multiwavelength source modulated by a spatial light modulator. Compared with conventional pseudo color imaging where there is no nondegenerate wavelength spatial correlations resulting in extra monochromatic images, the degenerate wavelength and nondegenerate wavelength spatial correlations between the idle beam and signal beam can be obtained simultaneously. This scheme can obtain more colorful image with higher quality than that in conventional pseudo color coding techniques. More importantly, a significant advantage of the scheme compared to the conventional pseudo color coding imaging techniques is the image with different colors can be obtained without changing the light source and spatial filter.

  2. Use of the Location Inverse Solution to Reduce Ghost Images

    Directory of Open Access Journals (Sweden)

    Yong-Zhong Hu

    2010-01-01

    Full Text Available Through-the-wall imaging (TWI is a difficult but important task for both law enforcement and military missions. Acquiring information on both the internal features of a structure and the location of people inside plays an important role in many fields such as antiterrorism, hostage search and rescue, and barricade situations. Up to now, a number of promising experimental systems have been developed to validate and evaluate diverse imaging methods, most of which are based on a linear antenna array to obtain an image of the objects. However, these methods typically use the backward projection (BP algorithm based on ellipse curves, which usually generates additional ghost images. In this paper, the algorithm using the location inverse solution (LIS to reduce the ghost images is proposed and simulated. The results of simulation show that this approach is feasible.

  3. On the state space of the dipole ghost

    International Nuclear Information System (INIS)

    Binegar, B.

    1984-01-01

    A particular representation of SO(4, 2) is identified with the state space of the free dipole ghost. This representation is then given an explicit realization as the solution space of a 4th-order wave equation on a spacetime locally isomorphic to Minkowski space. A discrete basis for this solution space is given, as well as an explicit expression for its SO(4, 2) invariant inner product. The connection between the modes of dipole field and those of the massless scalar field is clarified, and a recent conjecture concerning the restriction of the dipole representation to the Poincare subgroup is confirmed. A particular coordinate transformation then reveals the theory of the dipole ghost in Minkowski space. Finally, it is shown that the solution space of the dipole equation is not unitarizable in a Poincare invariant manner. (orig.)

  4. Phantom dark ghost in Einstein-Cartan gravity

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Yu-Chiao [National Taiwan University, Department of Physics, Taipei (China); National Taiwan University, LeCosPA, Taipei (China); Bouhmadi-Lopez, Mariam [University of the Basque Country UPV/EHU, Department of Theoretical Physics, P.O. Box 644, Bilbao (Spain); Basque Foundation for Science, IKERBASQUE, Bilbao (Spain); Chen, Pisin [National Taiwan University, Department of Physics, Taipei (China); National Taiwan University, LeCosPA, Taipei (China); National Taiwan University, Graduate Institute of Astrophysics, Taipei (China); SLAC National Accelerator Laboratory, Stanford University, Kavli Institute for Particle Astrophysics and Cosmology, Stanford, CA (United States)

    2017-05-15

    A class of dynamical dark energy models is constructed through an extended version of fermion fields corresponding to phantom dark ghost spinors, which are spin 1/2 with mass dimension 1. We find that if these spinors interact with torsion fields in a homogeneous and isotropic universe, then it does not imply any future dark energy singularity or any abrupt event, though the fermion has a negative kinetic energy. In fact, the equation of state of this dark energy model will asymptotically approach the value w = -1 from above without crossing the phantom divide and inducing therefore a de Sitter state. Consequently, we expect the model to be stable because no real phantom fields will be created. At late time, the torsion fields will vanish as the corresponding phantom dark ghost spinors dilute. As would be expected, intuitively, this result is unaffected by the presence of cold dark matter although the proof is not as straightforward as in general relativity. (orig.)

  5. Field theory of interacting open superstrings of fermionic ghost representation

    International Nuclear Information System (INIS)

    Aref'eva, I.Ya.; Medvedev, P.V.

    1987-01-01

    Field theory of interacting open superstring in fermionic ghost representation based on anticommuting and commuting ghosts corresponding respectively to world sheet bosonic x μ and fermionic φ μ coordinates is presented. The author have to revise once more the field theory of the free Ramond (R) string and starting from general algebraic point of view they obtain that the number of degrees of freedom in the R and NS (Neveu-Schwartz) sectors equalise themselves permitting to construct a supersymmetric operator. It is proposed to solve a specific equation guaranteeing superinvariance in order to find the R-R-NS and NS-R-R vertices in the term of the NS-NS-NS vertex

  6. Ghost imaging with paired x-ray photons

    Science.gov (United States)

    Schori, A.; Borodin, D.; Tamasaku, K.; Shwartz, S.

    2018-06-01

    We report the experimental observation of ghost imaging with paired x-ray photons, which are generated by parametric downconversion. We use the one-to-one relation between the photon energies and the emission angles and the anticorrelation between the k -vectors of the signal and the idler photons to reconstruct the images of slits with nominally zero background levels. Further extension of our procedure can be used for the observation of various quantum phenomena at x-ray wavelengths.

  7. Ghost circles in lattice Aubry-Mather theory

    Science.gov (United States)

    Mramor, Blaz; Rink, Bob

    Monotone lattice recurrence relations such as the Frenkel-Kontorova lattice, arise in Hamiltonian lattice mechanics, as models for ferromagnetism and as discretization of elliptic PDEs. Mathematically, they are a multi-dimensional counterpart of monotone twist maps. Such recurrence relations often admit a variational structure, so that the solutions x:Z→R are the stationary points of a formal action function W(x). Given any rotation vector ω∈R, classical Aubry-Mather theory establishes the existence of a large collection of solutions of ∇W(x)=0 of rotation vector ω. For irrational ω, this is the well-known Aubry-Mather set. It consists of global minimizers and it may have gaps. In this paper, we study the parabolic gradient flow {dx}/{dt}=-∇W(x) and we will prove that every Aubry-Mather set can be interpolated by a continuous gradient-flow invariant family, the so-called 'ghost circle'. The existence of these ghost circles is known in dimension d=1, for rational rotation vectors and Morse action functions. The main technical result of this paper is therefore a compactness theorem for lattice ghost circles, based on a parabolic Harnack inequality for the gradient flow. This implies the existence of lattice ghost circles of arbitrary rotation vectors and for arbitrary actions. As a consequence, we can give a simple proof of the fact that when an Aubry-Mather set has a gap, then this gap must be filled with minimizers, or contain a non-minimizing solution.

  8. Interacting viscous ghost tachyon, K-essence and dilaton scalar field models of dark energy

    International Nuclear Information System (INIS)

    Karami, K; Fahimi, K

    2013-01-01

    We study the correspondence between the interacting viscous ghost dark energy model with the tachyon, K-essence and dilaton scalar field models in the framework of Einstein gravity. We consider a spatially non-flat FRW universe filled with interacting viscous ghost dark energy and dark matter. We reconstruct both the dynamics and potential of these scalar field models according to the evolutionary behavior of the interacting viscous ghost dark energy model, which can describe the accelerated expansion of the universe. Our numerical results show that the interaction and viscosity have opposite effects on the evolutionary properties of the ghost scalar field models. (paper)

  9. Roles of the color antisymmetric ghost propagator in the Infrared QCD

    International Nuclear Information System (INIS)

    Furui, S.

    2009-01-01

    The results of Coulomb gauge and Landau gauge lattice QCD simulation do not agree completely with continuum theory. There are indications that the ghost propagator in the infrared region has strong fluctuation whose modulus is compatible with that of the color diagonal ghost propagator. After presenting lattice simulation of configurations produced with Kogut-Susskind fermion (MILC collaboration) and those with domain wall fermion (RBC/UKQCD collaboration), I investigate in triple gluon vertex and the ghost-gluon-ghost vertex how the square of the color antisymmetric ghost contributes. Then the effect of the vertex correction to the gluon propagator and the ghost propagator is investigated. Recent Dyson-Schwinger equation analysis suggests the ghost dressing function G(0) = finite and no infrared enhancement or a G = 0. But the ghost propagator renormalized by the loop containing a product of color antisymmetric ghost is expected to behave as [cc] r = - (G(q 2 ))/(q 2 ) with G(q 2 ) ∝ q -2aG with a G = 0.5, if the fixed point scenario is valid. I interpret the a G = 0 solution should contain a vertex correction. The infrared exponent of our lattice Landau gauge gluon propagator of the RBC/UKQCD is a D = - 0.5 and that of MILC is about - 0.7. A possible interpretation of the origin of the fluctuation is given. (author)

  10. Y-formalism and b ghost in the non-minimal pure spinor formalism of superstrings

    International Nuclear Information System (INIS)

    Oda, Ichiro; Tonin, Mario

    2007-01-01

    We present the Y-formalism for the non-minimal pure spinor quantization of superstrings. In the framework of this formalism we compute, at the quantum level, the explicit form of the compound operators involved in the construction of the b ghost, their normal-ordering contributions and the relevant relations among them. We use these results to construct the quantum-mechanical b ghost in the non-minimal pure spinor formalism. Moreover we show that this non-minimal b ghost is cohomologically equivalent to the non-covariant b ghost

  11. Analysis of ghost image in high power laser system using computer

    International Nuclear Information System (INIS)

    Zhang Qingquan; Liu Jinsong; Wang Kejia; Zhu Qihua; Zhao Runchang; Wang Fang

    2011-01-01

    Using a self-made software named CatchGhost the ghost points' position and energy in a coaxial optic systems were calculated accurately in a short time without omission. The software can carry out massive calculation in a short time, and pick out the harmful ghosts in system automatically. Because all the elements which are related to beams' energy,including the pinhole' effect, reflectivity,gain and loss,are counted, data of ghost points given by the software are exact and useful. (authors)

  12. Physicochemical characterization of artificial nanoerythrosomes derived from erythrocyte ghost membranes.

    Science.gov (United States)

    Deák, Róbert; Mihály, Judith; Szigyártó, Imola Cs; Wacha, András; Lelkes, Gábor; Bóta, Attila

    2015-11-01

    Colloidal stabile nanoerythrosomes with 200 nm average diameter were formed from hemoglobin-free erythrocyte ghost membrane via sonication and membrane extrusion. The incorporation of extra lipid (1,2-dipalmitoyl-sn-glycero-3-phosphocholine, DPPC), added to the sonicated ghosts, caused significant changes in the thermotropic character of the original membranes. As a result of the increased DPPC ratio the chain melting of the hydrated DPPC system and the characteristic small angle X-ray scattering (SAXS) of the lipid bilayers appeared. Significant morphological changes were followed by transmission electron microscopy combined with freeze fracture method (FF-TEM). After the ultrasonic treatment the large entities of erythrocyte ghosts transformed into nearly spherical nanoerythrosomes with diameters between 100 and 300 nm and at the same time a great number of 10-30 nm large membrane proteins or protein clusters were dispersed in the aqueous medium. The infrared spectroscopy (FT-IR) pointed out, that the sonication did not cause changes in the secondary structures of the membrane proteins under our preparation conditions. About fivefold of extra lipid--compared to the lipid content of the original membrane--caused homogeneous dispersion of nanoerythrosomes however the shape of the vesicles was not uniform. After the addition of about tenfold of DPPC, monoform and monodisperse nanoerythrosomes became typical. The outer surfaces of these roughly spherical objects were frequently polygonal, consisting of a net of pentagons and hexagons. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Annual air pollution caused by the Hungry Ghost Festival.

    Science.gov (United States)

    Khezri, B; Chan, Y Y; Tiong, L Y D; Webster, R D

    2015-09-01

    Burning of joss paper and incense is still a very common traditional custom in countries with a majority Chinese population. The Hungry Ghost Festival which is celebrated in the 7 month of the Chinese calendar is one of the events where joss paper and incense are burned as offerings. This study investigates the impact of the Ghost Month Festival (open burning event) on air quality by analysis of the chemical composition of particulate matter (PM) and rainwater samples collected during this event, compared with data collected throughout the year, as well as bottom ash samples from burning the original joss paper and incense. The results showed that the change in the chemical composition of the rainwater and PM2.5 (PM ≤ 2.5 μm) atmospheric samples could be correlated directly with burning events during this festival, with many elements increasing between 18% and 60% during August and September compared to the yearly mean concentrations. The order of percentage increase in elemental composition (in rain water and PM2.5) during the Hungry Ghost Festival is as follows: Zn > Ca > K > Mg > Fe > Al > Na ∼ Mn ∼ Ti ∼ V > Cu > As > Ni > Co > Cd > Cr > Pb. The chemical composition of the original source materials (joss paper and incense for combustion) and their associated bottom ash were analysed to explain the impact of burning on air quality.

  14. Tsunami and ghost stories in Thailand: exploring the psychology of ghosts and religious rituals within the context of Thai Buddhism.

    Science.gov (United States)

    Sorajjakool, Siroj

    2007-01-01

    The post-tsunami ghost phenomena in Thailand may be understood, in Jungian terms, as an expression of the autonomous complex of the collective psyche resulting from traumatic loss. Religious rituals, as in the context of Thai Buddhism, provide an alternative method of dealing with grief, and hence they affirm the place of religious practices in the overall psychological well-being of people from various cultural backgrounds.

  15. An accurate conservative level set/ghost fluid method for simulating turbulent atomization

    International Nuclear Information System (INIS)

    Desjardins, Olivier; Moureau, Vincent; Pitsch, Heinz

    2008-01-01

    This paper presents a novel methodology for simulating incompressible two-phase flows by combining an improved version of the conservative level set technique introduced in [E. Olsson, G. Kreiss, A conservative level set method for two phase flow, J. Comput. Phys. 210 (2005) 225-246] with a ghost fluid approach. By employing a hyperbolic tangent level set function that is transported and re-initialized using fully conservative numerical schemes, mass conservation issues that are known to affect level set methods are greatly reduced. In order to improve the accuracy of the conservative level set method, high order numerical schemes are used. The overall robustness of the numerical approach is increased by computing the interface normals from a signed distance function reconstructed from the hyperbolic tangent level set by a fast marching method. The convergence of the curvature calculation is ensured by using a least squares reconstruction. The ghost fluid technique provides a way of handling the interfacial forces and large density jumps associated with two-phase flows with good accuracy, while avoiding artificial spreading of the interface. Since the proposed approach relies on partial differential equations, its implementation is straightforward in all coordinate systems, and it benefits from high parallel efficiency. The robustness and efficiency of the approach is further improved by using implicit schemes for the interface transport and re-initialization equations, as well as for the momentum solver. The performance of the method is assessed through both classical level set transport tests and simple two-phase flow examples including topology changes. It is then applied to simulate turbulent atomization of a liquid Diesel jet at Re=3000. The conservation errors associated with the accurate conservative level set technique are shown to remain small even for this complex case

  16. 50 CFR 697.21 - Gear identification and marking, escape vent, maximum trap size, and ghost panel requirements.

    Science.gov (United States)

    2010-10-01

    ... vent, maximum trap size, and ghost panel requirements. 697.21 Section 697.21 Wildlife and Fisheries... identification and marking, escape vent, maximum trap size, and ghost panel requirements. (a) Gear identification... Administrator finds to be consistent with paragraph (c) of this section. (d) Ghost panel. (1) Lobster traps not...

  17. 76 FR 76812 - Requested Administrative Waiver of the Coastwise Trade Laws: Vessel BARBARY GHOST; Invitation for...

    Science.gov (United States)

    2011-12-08

    ... DEPARTMENT OF TRANSPORTATION Maritime Administration [Docket No. MARAD 2011 0148] Requested Administrative Waiver of the Coastwise Trade Laws: Vessel BARBARY GHOST; Invitation for Public Comments AGENCY... BARBARY GHOST is: Intended Commercial Use Of Vessel: ``Sightseeing tours in the San Francisco Bay for a...

  18. Hydraulic activities by ghost shrimp Neotrypaea californiensis induce oxic-anoxic oscillations in sediments

    Science.gov (United States)

    We applied porewater pressure sensing, time-lapse photography and planar optode imaging of oxygen to investigate hydraulic behaviors of the Thalassinidean ghost shrimp Neotrypaea californiensis and the associated dynamics of oxygen in and around their burrows. Ghost shrimp were h...

  19. The Ghost in the Touchscreen: Social Scaffolds Promote Learning by Toddlers

    Science.gov (United States)

    Zimmermann, Laura; Moser, Alecia; Lee, Herietta; Gerhardstein, Peter; Barr, Rachel

    2017-01-01

    This study examined the effect of a "ghost" demonstration on toddlers' imitation. In the "ghost" condition, virtual pieces moved to make a fish or boat puzzle. Fifty-two 2.5- and 3-year-olds were tested on a touchscreen (no transfer) or with 3D pieces (transfer); children tested with 3D pieces scored above a no demonstration…

  20. Harry Potter and the Ghost Teacher: Resurrecting the Lost Art of Lecturing

    Science.gov (United States)

    McDaniel, Kathryn N.

    2010-01-01

    A significant image of classroom lectures is the one presented in J. K. Rowling's "Harry Potter" series. At Harry's Hogwarts School of Witchcraft and Wizardry, the most torturous class is easily History of Magic, which is, incidentally, the only class in the school taught by a ghost. Being taught by a ghost could be quite exciting: not so in…

  1. Hunting The Ghost Gun: An Analysis Of The U.S. Army Infantry Rifle

    Science.gov (United States)

    2016-03-01

    NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA JOINT APPLIED PROJECT HUNTING THE GHOST GUN : AN ANALYSIS OF THE U.S. ARMY......LEFT BLANK iii Approved for public release; distribution is unlimited HUNTING THE GHOST GUN : AN ANALYSIS OF THE U.S. ARMY INFANTRY

  2. Simplified pure spinor b ghost in a curved heterotic superstring background

    Energy Technology Data Exchange (ETDEWEB)

    Berkovits, Nathan [ICTP South American Institute for Fundamental Research,Instituto de Física Teórica, UNESP - Universidade Estadual Paulista,Rua Dr. Bento T. Ferraz 271, 01140-070, São Paulo, SP (Brazil); Chandia, Osvaldo [Departamento de Ciencias, Facultad de Artes Liberales,Facultad de Ingeniería y Ciencias, Universidad Adolfo Ibáñez,Diagonal Las Torres 2640, Peñalolén, Santiago (Chile)

    2014-06-03

    Using the RNS-like fermionic vector variables introduced in arXiv:1305.0693, the pure spinor b ghost in a curved heterotic superstring background is easily constructed. This construction simplifies and completes the b ghost construction in a curved background of arXiv:1311.7012.

  3. 128 Gothicism/Ghost Stories in Nigerian Literature: Facts or Fiction ...

    African Journals Online (AJOL)

    Ike Odimegwu

    In The Castle of Otranto, a gigantic hand in armour, a ghost ling figure, a vast helmet ... literature, the “literary ghost stories are stories written by creative artists who .... nurses, lovers, civil servants, the palm wine tapers, widows, job applicants ...

  4. Image quality enhancement in low-light-level ghost imaging using modified compressive sensing method

    Science.gov (United States)

    Shi, Xiaohui; Huang, Xianwei; Nan, Suqin; Li, Hengxing; Bai, Yanfeng; Fu, Xiquan

    2018-04-01

    Detector noise has a significantly negative impact on ghost imaging at low light levels, especially for existing recovery algorithm. Based on the characteristics of the additive detector noise, a method named modified compressive sensing ghost imaging is proposed to reduce the background imposed by the randomly distributed detector noise at signal path. Experimental results show that, with an appropriate choice of threshold value, modified compressive sensing ghost imaging algorithm can dramatically enhance the contrast-to-noise ratio of the object reconstruction significantly compared with traditional ghost imaging and compressive sensing ghost imaging methods. The relationship between the contrast-to-noise ratio of the reconstruction image and the intensity ratio (namely, the average signal intensity to average noise intensity ratio) for the three reconstruction algorithms are also discussed. This noise suppression imaging technique will have great applications in remote-sensing and security areas.

  5. Lag and ghosting in a clinical flat-panel selenium digital mammography system

    International Nuclear Information System (INIS)

    Bloomquist, Aili K.; Yaffe, Martin J.; Mawdsley, Gordon E.; Hunter, David M.; Beideck, Daniel J.

    2006-01-01

    We present measurements of lag and ghosting in a FDA-approved digital mammography system that uses a dielectric/selenium based detector structure. Lag is the carryover of signal from a previous image, whereas ghosting is the reduction of sensitivity caused by previous exposure history of the detector. Data from six selenium units were acquired. For the type of selenium detector tested, and under typical clinical usage conditions, the lag was as high as 0.15% of source signal and the ghosting could be as high as 15%. The amount of lag and ghosting varied from unit to unit. Results were compared with data acquired on a phosphor-based full-field digital mammography system. Modifications in the technology of the selenium detectors appear to have resulted in a marked decrease in both lag and ghosting effects in more recent systems

  6. Evidence of marine debris usage by the ghost crab Ocypode quadrata (Fabricius, 1787).

    Science.gov (United States)

    Costa, Leonardo Lopes; Rangel, Danilo Freitas; Zalmon, Ilana Rosental

    2018-03-01

    Sandy beaches are sites of marine debris stranding, but the interaction of beach biota with waste is poorly studied. The objective of this study was to investigate whether the ghost crab Ocypode quadrata selects marine debris by types using a non-destructive method on sandy beaches of Southeastern Brazil. We found marine debris in 7% of 1696 surveyed burrows, and the ghost crabs selectivity was mainly by soft plastic (30%), straw (11%), rope (6%) and foam (4%). Burrows with marine debris showed higher occupation rate (~68%) compared to burrows without debris (~28%), indicating that these materials may increase the capacity of ghost crabs to memorize their burrows placement (homing). The percentage of marine debris was not always related to their amount in the drift line, but ghost crabs used more debris near urbanized areas. Future studies should test whether ghost crabs are using marine debris for feeding, homing or other mechanisms. Copyright © 2018 Elsevier Ltd. All rights reserved.

  7. Ghost sector of vacuum string field theory and the projection equation

    International Nuclear Information System (INIS)

    Potting, Robertus; Raeymaekers, Joris

    2002-01-01

    We study the ghost sector of vacuum string field theory where the BRST operator Q is given by the midpoint insertion proposed by Gaiotto, Rastelli, Sen and Zwiebach. We introduce a convenient basis of half-string modes in terms of which Q takes a particularly simple form. We show that there exists a field redefinition which reduces the ghost sector field equation to a pure projection equation for string fields satisfying the constraint that the ghost number is equally divided over the left- and right halves of the string. When this constraint is imposed, vacuum string field theory can be reformulated as a U(∞) cubic matrix model. Ghost sector solutions can be constructed from projection operators on half-string Hilbert space just as in the matter sector. We construct the ghost sector equivalent of various well-known matter sector projectors such as the sliver, butterfly and nothing states. (author)

  8. Energy based prediction models for building acoustics

    DEFF Research Database (Denmark)

    Brunskog, Jonas

    2012-01-01

    In order to reach robust and simplified yet accurate prediction models, energy based principle are commonly used in many fields of acoustics, especially in building acoustics. This includes simple energy flow models, the framework of statistical energy analysis (SEA) as well as more elaborated...... principles as, e.g., wave intensity analysis (WIA). The European standards for building acoustic predictions, the EN 12354 series, are based on energy flow and SEA principles. In the present paper, different energy based prediction models are discussed and critically reviewed. Special attention is placed...... on underlying basic assumptions, such as diffuse fields, high modal overlap, resonant field being dominant, etc., and the consequences of these in terms of limitations in the theory and in the practical use of the models....

  9. Kaehler-Dirac ghosts for self-dual fields

    International Nuclear Information System (INIS)

    Labastida, J.M.F.; Pernici, M.

    1988-01-01

    We present the generalization to spacetime dimension D=4n+2 of the Lorentz covariant quadratic lagrangian for pairs of (anti)self-dual fields previously obtained by the authors in D=2. In the process of BRST quantizing this lagrangian a first-order quadratic lagrangian for ghost (anti)self-dual fields is found which, after gauge fixing, can be written in terms of bispinors and it turns out to be a Kaehler-Dirac lagrangian. The coupling to gravity is straightforward and the gravitational anomaly due to (anti)self-dual fields is obtained directly from an action principle. (orig.)

  10. Robust reflective ghost imaging against different partially polarized thermal light

    Science.gov (United States)

    Li, Hong-Guo; Wang, Yan; Zhang, Rui-Xue; Zhang, De-Jian; Liu, Hong-Chao; Li, Zong-Guo; Xiong, Jun

    2018-03-01

    We theoretically study the influence of degree of polarization (DOP) of thermal light on the contrast-to-noise ratio (CNR) of the reflective ghost imaging (RGI), which is a novel and indirect imaging modality. An expression for the CNR of RGI with partially polarized thermal light is carefully derived, which suggests a weak dependence of CNR on the DOP, especially when the ratio of the object size to the speckle size of thermal light has a large value. Different from conventional imaging approaches, our work reveals that RGI is much more robust against the DOP of the light source, which thereby has advantages in practical applications, such as remote sensing.

  11. Recovery of compacted soils in Mojave Desert ghost towns.

    Science.gov (United States)

    Webb, R.H.; Steiger, J.W.; Wilshire, H.G.

    1986-01-01

    Residual compaction of soils was measured at seven sites in five Mojave Desert ghost towns. Soils in these Death Valley National Monument townsites were compacted by vehicles, animals, and human trampling, and the townsites had been completely abandoned and the buildings removed for 64 to 75 yr. Recovery times extrapolated using a linear recovery model ranged from 80 to 140 yr and averaged 100 yr. The recovery times were related to elevation, suggesting freeze-thaw loosening as an important factor in ameliorating soil compaction in the Mojave Desert. -from Authors

  12. Information Security Scheme Based on Computational Temporal Ghost Imaging.

    Science.gov (United States)

    Jiang, Shan; Wang, Yurong; Long, Tao; Meng, Xiangfeng; Yang, Xiulun; Shu, Rong; Sun, Baoqing

    2017-08-09

    An information security scheme based on computational temporal ghost imaging is proposed. A sequence of independent 2D random binary patterns are used as encryption key to multiply with the 1D data stream. The cipher text is obtained by summing the weighted encryption key. The decryption process can be realized by correlation measurement between the encrypted information and the encryption key. Due to the instinct high-level randomness of the key, the security of this method is greatly guaranteed. The feasibility of this method and robustness against both occlusion and additional noise attacks are discussed with simulation, respectively.

  13. Influence map baserad Ms. Pac-Man och Ghost Kontroller

    OpenAIRE

    Svensson, Johan

    2012-01-01

    This thesis will cover the use oftheinfluence map technique applied to the retro game Ms. Pac-Man. A game thatis easy to learn but hard to master. The Ms. Pac-Man controller is implemented with five main parameters that alters the behaviour of the controller while the Ghost controller have three parameters. The experimental results of the controllers is explored to using the alterations of the parameters to find its peak of performance. The conclusion from using the influence map for this gam...

  14. Ghost properties of algebraically extended theories of gravitation

    International Nuclear Information System (INIS)

    Kelly, P.F.; Mann, R.B.

    1986-01-01

    Recently a technique for extending general relativity called algebraic extension was shown to yield only five classes of gravitational theories (general relativity plus four extensions). The particle spectra of these theories are analysed and it is shown that only one of these extensions is ghost free. Two inequivalent theories are shown to result from this extension at the linearised level. One of these is the linearised version of Moffat's theory of gravitation; the other is a new theory which possesses an additional gauge invariance which has been associated with a closed string. (author)

  15. Ghosts of the City: A Spectrology of Cinematic Spaces

    Directory of Open Access Journals (Sweden)

    Petra Löffler

    2015-09-01

    Full Text Available This paper investigates how, in early cinema, in-between spaces were created that were receptive to scenes of haunting. Adopting Derrida’s notions of a hauntology and a spectrology it argues for a genuine productivity of cinematic space that is able to build ghostly environments without incorporating an actual specter. This productivity is described as ‘making appear’ and ‘making act’. Furthermore, the paper explains how, in the era of silent cinema, cinematic techniques were used to create scenes of haunting.

  16. Ghosts of the City: A Spectrology of Cinematic Spaces

    OpenAIRE

    Petra Löffler

    2015-01-01

    This paper investigates how, in early cinema, in-between spaces were created that were receptive to scenes of haunting. Adopting Derrida’s notions of a hauntology and a spectrology it argues for a genuine productivity of cinematic space that is able to build ghostly environments without incorporating an actual specter. This productivity is described as ‘making appear’ and ‘making act’. Furthermore, the paper explains how, in the era of silent cinema, cinematic techniques were used to create s...

  17. An algebraic approach to laying a ghost to rest

    International Nuclear Information System (INIS)

    Nucci, M C; Leach, P G L

    2010-01-01

    In the recent literature there has been a resurgence of interest in the fourth-order field-theoretic model of Pais-Uhlenbeck (1950 Phys. Rev. 79 145-65) which has not had a good reception over the past half a century due to the existence of ghosts in the properties of the quantum mechanical solution. Bender and Mannheim (2008 J. Phys. A: Math. Theor. 41 304018) were successful in persuading the corresponding quantum operator to 'give up the ghost'. Their success had the advantage of making the model of Pais-Uhlenbeck acceptable to the physics community and in the process added further credit to the cause of advancement of the use of PT symmetry. We present a case for the acceptance of the Pais-Uhlenbeck model in the context of Dirac's theory by providing an Hamiltonian that is not quantum mechanically haunted. The essential point is the manner in which a fourth-order equation is rendered into a system of second-order equations. We show by means of the method of reduction of order (Nucci M C 1996 J. Math. Phys. 37 1772-5) that it is possible to construct a Hamiltonian that gives rise to a satisfactory quantal description without having to abandon Dirac.

  18. Luisa's Ghosts: Haunted Legality and Collective Expressions of Pain.

    Science.gov (United States)

    Krauss, Amy

    2018-04-25

    Feminist health care providers have debated the efficacy of the decriminalization of abortion in Mexico City. Luisa, a counselor in a private clinic, suggested that while the law has expanded the visibility of, and access to safe abortion, it has also called forth "other ghosts." In this article, I take Luisa's critical perspective as a starting point for examining ongoing criminalization and moral stigma as forms of haunting that arise in the wake of the Mexico City abortion policy. Drawing on ethnographic research, I explore how Luisa's ghosts materialize in the embodied- affective relations between patients in new legal clinics. Women who attend public clinics negotiate moral stigma along with religious and familial pressures in the ways they suffer, as well as normalize abortion as a painful experience. Rather than approach pain as purely a sign of victimization, I suggest that its expression constitutes an effervescent collectivity between women in the clinic, making explicit, while at the same time dissipating, an intractable moral-affective knot that might otherwise be ignored.

  19. Chandra Finds Ghosts Of Eruption In Galaxy Cluster

    Science.gov (United States)

    2002-01-01

    "Ghostly" relics of an ancient eruption that tore through a cluster of galaxies were recently uncovered by NASA's Chandra X-ray Observatory. The discovery implies that galaxy clusters are the sites of enormously energetic and recurring explosions, and may provide an explanation why galaxy clusters behave like giant cosmic magnets. "Chandra's image revealed vast regions in the galaxy cluster Abell 2597 that contain almost no X-ray or radio emission. We call them ghost cavities," said Brian McNamara of Ohio University in Athens today during a press conference at the American Astronomical Society meeting in Washington. "They appear to be remnants of an old explosion where the radio emission has faded away over millions of years." The ghost cavities were likely created by extremely powerful explosions, due to material falling toward a black hole millions of times more massive than the Sun. As the matter swirled around the black hole, located in a galaxy near the center of the cluster, it generated enormous electromagnetic fields that expelled material from the vicinity of the black hole at high speeds. This explosive activity in Abell 2597 created jets of highly energetic particles that cleared out voids in the hot gas. Because they are lighter than the surrounding material, the cavities will eventually push their way to the edge of the cluster, just as air bubbles in water make their way to the surface. Researchers also found evidence that this explosion was not a one-time event. "We detected a small, bright radio source near the center of the cluster that indicates a new explosion has occurred recently," said team member Michael Wise of the Massachusetts Institute of Technology in Cambridge, "so the cycle of eruption is apparently continuing." Though dim, the ghost cavities are not completely empty. They contain a mixture of very hot gas, high-energy particles and magnetic fields -- otherwise the cavities would have collapsed under the pressure of the surrounding hot

  20. An Improved Ghost-cell Immersed Boundary Method for Compressible Inviscid Flow Simulations

    KAUST Repository

    Chi, Cheng

    2015-05-01

    This study presents an improved ghost-cell immersed boundary approach to represent a solid body in compressible flow simulations. In contrast to the commonly used approaches, in the present work ghost cells are mirrored through the boundary described using a level-set method to farther image points, incorporating a higher-order extra/interpolation scheme for the ghost cell values. In addition, a shock sensor is in- troduced to deal with image points near the discontinuities in the flow field. Adaptive mesh refinement (AMR) is used to improve the representation of the geometry efficiently. The improved ghost-cell method is validated against five test cases: (a) double Mach reflections on a ramp, (b) supersonic flows in a wind tunnel with a forward- facing step, (c) supersonic flows over a circular cylinder, (d) smooth Prandtl-Meyer expansion flows, and (e) steady shock-induced combustion over a wedge. It is demonstrated that the improved ghost-cell method can reach the accuracy of second order in L1 norm and higher than first order in L∞ norm. Direct comparisons against the cut-cell method demonstrate that the improved ghost-cell method is almost equally accurate with better efficiency for boundary representation in high-fidelity compressible flow simulations. Implementation of the improved ghost-cell method in reacting Euler flows further validates its general applicability for compressible flow simulations.

  1. Ghost reflections of Gaussian beams in anamorphic optical systems with an application to Michelson interferometer.

    Science.gov (United States)

    Abd El-Maksoud, Rania H

    2016-02-20

    In this paper, a methodology is developed to model and analyze the effect of undesired (ghost) reflections of Gaussian beams that are produced by anamorphic optical systems. The superposition of these beams with the nominal beam modulates the nominal power distribution at the recording plane. This modulation may cause contrast reduction, veiling parts of the nominal image, and/or the formation of spurious interference fringes. The developed methodology is based on synthesizing the beam optical paths into nominal and ghost optical beam paths. Similar to the nominal beam, we present the concept that each ghost beam is characterized by a beam size, wavefront radius of curvature, and Gouy phase in the paraxial regime. The nominal and ghost beams are sequentially traced through the system and formulas for estimating the electric field magnitude and phase of each ghost beam at the recording plane are presented. The effective electric field is the addition of the individual nominal and ghost electric fields. Formulas for estimating Gouy phase, the shape of the interference fringes, and the central interference order are introduced. As an application, the theory of the formation of the interference fringes by Michelson interferometer is presented. This theory takes into consideration the ghost reflections that are formed by the beam splitter. To illustrate the theory and to show its wide applicability, simulation examples that include a Mangin mirror, a Michelson interferometer, and a black box optical system are provided.

  2. Gravitational lensing and ghost images in the regular Bardeen no-horizon spacetimes

    International Nuclear Information System (INIS)

    Schee, Jan; Stuchlík, Zdeněk

    2015-01-01

    We study deflection of light rays and gravitational lensing in the regular Bardeen no-horizon spacetimes. Flatness of these spacetimes in the central region implies existence of interesting optical effects related to photons crossing the gravitational field of the no-horizon spacetimes with low impact parameters. These effects occur due to existence of a critical impact parameter giving maximal deflection of light rays in the Bardeen no-horizon spacetimes. We give the critical impact parameter in dependence on the specific charge of the spacetimes, and discuss 'ghost' direct and indirect images of Keplerian discs, generated by photons with low impact parameters. The ghost direct images can occur only for large inclination angles of distant observers, while ghost indirect images can occur also for small inclination angles. We determine the range of the frequency shift of photons generating the ghost images and determine distribution of the frequency shift across these images. We compare them to those of the standard direct images of the Keplerian discs. The difference of the ranges of the frequency shift on the ghost and direct images could serve as a quantitative measure of the Bardeen no-horizon spacetimes. The regions of the Keplerian discs giving the ghost images are determined in dependence on the specific charge of the no-horizon spacetimes. For comparison we construct direct and indirect (ordinary and ghost) images of Keplerian discs around Reissner-Nördström naked singularities demonstrating a clear qualitative difference to the ghost direct images in the regular Bardeen no-horizon spacetimes. The optical effects related to the low impact parameter photons thus give clear signature of the regular Bardeen no-horizon spacetimes, as no similar phenomena could occur in the black hole or naked singularity spacetimes. Similar direct ghost images have to occur in any regular no-horizon spacetimes having nearly flat central region

  3. Effects of the quark field on the ghost propagator of lattice Landau gauge QCD

    International Nuclear Information System (INIS)

    Furui, Sadataka; Nakajima, Hideo

    2006-01-01

    Infrared features of the ghost propagator of color-diagonal and color antisymmetric ghost propagator of quenched SU(2) and quenched SU(3) are compared with those of unquenched Kogut-Susskind fermion SU(3) lattice Landau gauge. We compare (i) the fluctuation of the ghost propagator (ii) the ghost condensate parameter v of the local composite operator (LCO) approach, and (iii) the Binder cumulant of color antisymmetric ghost propagator between quenched and unquenched configurations. The color-diagonal SU(3) ghost dressing function of unquenched configurations has weaker singularity than the quenched configurations. In both cases fluctuations become large in q c configuration samples is ∼0.002-0.04 GeV 2 while that of the SU(2) parallel tempering samples is consistent with 0. The Binder cumulant defined as U(q)=1-(1/3)( 4 >/( 2 >) 2 ), where φ-vector(q) is the color antisymmetric ghost propagator measured by the sample average of gauge fixed configurations via parallel tempering method, becomes ∼4/9 in all the momentum region. The Binder cumulant of the color antisymmetric ghost propagator of quenched SU(2) can be explained by the 3D Gaussian distribution, but that of the unquenched MILC c deviates slightly from that of the eight-dimensional Gaussian distribution. The stronger singularity and large fluctuation in the quenched configuration could be the cause of the deviation of the Kugo-Ojima confinement parameter c from 1, and the presence of ordering in the ghost propagator of unquenched configurations makes it closer to 1

  4. The BRST quantization and the no-ghost theorem for AdS3

    International Nuclear Information System (INIS)

    Asano, Masako; Natsuume, Makoto

    2003-01-01

    In our previous papers, we prove the no-ghost theorem without light-cone directions. We point out that our results are valid for more general backgrounds. In particular, we prove the no-ghost theorem for AdS 3 in the context of the BRST quantization (with the standard restriction on the spin). We compare our BRST proof with the OCQ proof and establish the BRST-OCQ equivalence for AdS 3 . The key in both approaches lies in the certain structure of the matter Hilbert space as a product of two Verma modules. We also present the no-ghost theorem in the most general form. (author)

  5. Theoretical study of ghost imaging with cold atomic waves under the condition of partial coherence

    International Nuclear Information System (INIS)

    Chen, Jun; Liu, Yun-Xian

    2014-01-01

    A matter wave ghost imaging mechanism is proposed and demonstrated theoretically. This mechanism is based on the Talbot-Lau effect. Periodic gratings of matter wave density, which appear as a result of interference of atoms diffracted by pulses of an optical standing wave, are utilized to produce the reference wave and the signal wave simultaneously for the ghost imaging. An advantage of this mechanism is that during the imaging process, the beam-splitter is not needed, which highly simplifies the experimental setup and makes the ghost imaging possible in the field of matter wave

  6. Ghost free massive gravity in the Stückelberg language

    International Nuclear Information System (INIS)

    Rham, Claudia de; Gabadadze, Gregory; Tolley, Andrew J.

    2012-01-01

    Massive gravity in 4 dimensions has been shown to be free of the Boulware-Deser (BD) ghost in the ADM language for a specific choice of mass terms. We show here how this is consistent with the Stückelberg language beyond the decoupling limit, and how the constraint required to remove the BD ghost arises in this framework non-perturbatively, without the use of field redefinitions. We emphasize a subtlety in obtaining this constraint, that has been overlooked in previous literature. In both the ADM and Stückelberg formalisms the vanishing of the determinant of a Hessian guarantees the absence of the BD ghost.

  7. Vacuum correlation functions for ghost superfields and multiloop amplitudes in the theory of closed superstrings

    International Nuclear Information System (INIS)

    Danilov, G.S.

    1995-01-01

    A new formalism for ghosts on complex (1 bar 1) supermanifolds of genus n > 1 is discussed in superstring theory. In this formalism, vacuum correlation functions for ghost superfields differ substantially from correlation functions discussed earlier. In particular, the new correlation functions do not have unphysical poles. Among other things, these correlation functions take into account contributions to partition functions from the phase space of modular forms and from zero modes of ghosts. The above correlation functions, obtained for all even spinor structures, can be used to evaluate partition functions from equations that are nothing but Ward identities. 21 refs

  8. Ghosts in the self-accelerating DGP branch with Gauss–Bonnet effect

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yen-Wei; Izumi, Keisuke; Bouhmadi-López, Mariam; Chen, Pisin

    2015-06-01

    The Dvali–Gabadadze–Porrati brane-world model provides a possible approach to address the late-time cosmic acceleration. However, it has subsequently been pointed out that a ghost instability will arise on the self-accelerating branch. Here, we carefully investigate whether this ghost problem could be possibly cured by introducing the Gauss–Bonnet term in the five-dimensional bulk action, a natural generalization to the Dvali–Gabadadze–Porrati model. Our analysis is carried out for a background where a de Sitter brane is embedded in an anti–de Sitter bulk. Our result shows that the ghost excitations cannot be avoided even in this modified model.

  9. Edge detection based on computational ghost imaging with structured illuminations

    Science.gov (United States)

    Yuan, Sheng; Xiang, Dong; Liu, Xuemei; Zhou, Xin; Bing, Pibin

    2018-03-01

    Edge detection is one of the most important tools to recognize the features of an object. In this paper, we propose an optical edge detection method based on computational ghost imaging (CGI) with structured illuminations which are generated by an interference system. The structured intensity patterns are designed to make the edge of an object be directly imaged from detected data in CGI. This edge detection method can extract the boundaries for both binary and grayscale objects in any direction at one time. We also numerically test the influence of distance deviations in the interference system on edge extraction, i.e., the tolerance of the optical edge detection system to distance deviation. Hopefully, it may provide a guideline for scholars to build an experimental system.

  10. Ghosting Politics: Speechwriters, Speechmakers and the (Recrafting of Identity

    Directory of Open Access Journals (Sweden)

    Michael Richardson

    2017-11-01

    Full Text Available Despite public awareness of their role, speechwriters occupy an anxiously liminal position within the political process. As the ongoing dispute between former Australian prime minister Paul Keating and Don Watson over the Redfern Speech suggests, the authorship and ownership of speeches can be a fraught proposition, no matter the professional codes. Crafting and re-crafting identity places speechwriter and speechmaker in a relation of intense intimacy, one in which neither party may be comfortable and from which both may well emerge changed. Having written speeches for Jack Layton, former leader of the New Democratic Party of Canada, I know just how complex, uncertain and productive that relation can be. This article conceives of identity as transindividual, formed in the intensity and flux of encounter, and weaves together the personal and the critical to examine politics’ speechwriting ghost.

  11. Ghost forest creation and the conversion of uplands to wetlands

    Science.gov (United States)

    Kirwan, M. L.; Schieder, N. W.; Reay, W.

    2017-12-01

    Global sea level rise rates began accelerating sharply in the late 19th century, with an approximate tripling in sea level rise rates in many regions of the world. Some portions of the coastal landscape, such as marshes and barrier islands, survive relative sea level rise by natural eco-geomorphic processes that allow them to build elevation vertically and migrate landward. In contrast, adjacent uplands typically occupied by forests and agricultural fields have limited ability to resist the impacts of sea level rise. This portion of the coastal landscape consists of mostly salt intolerant plants, receives little mineral sediment deposition, and rarely builds elevation through the accumulation of soil organic matter. Thus, ghost forests- dead trees surrounded by marshland- are a prominent feature of many low-relief coastal landscapes, and represent a striking visual indicator of upland to wetland conversion. Here, we report preliminary results of several efforts designed to quantify rates and drivers of upland to wetland conversion in the mid-Atlantic region of the United States. Drone based canopy monitoring and ground-based seedling experiments suggest that ghost forests are created by episodic, storm-driven adult tree mortality paired with continuous seedling mortality. Preliminary comparisons between sediment cores and historical photographs from 5 sites in Maryland, Virginia, and North Carolina suggest that modern coastal forest retreat is 2-10 times faster than late-Holocene retreat rates, and that rates have accelerated in most decades since the 1930's. Finally, historical T-Sheet maps suggest that approximately 100,000 acres (400 km2) of uplands have converted to wetlands in the Chesapeake region, and that about 1/3 of all present-day marsh was created by upland drowning since the late 19th Century. Together, these observations indicate rapid coastal transgression, where low-relief, terrestrial portions of the coastal landscape are perhaps more sensitive to

  12. Enhancing Tomo-PIV reconstruction quality by reducing ghost particles

    International Nuclear Information System (INIS)

    De Silva, C M; Baidya, R; Marusic, I

    2013-01-01

    A technique to enhance the reconstruction quality and consequently the accuracy of the velocity vector field obtained in Tomo-PIV experiments is presented here. The methodology involves detecting and eliminating spurious outliers in the reconstructed intensity field (ghost particles). A simulacrum matching-based reconstruction enhancement (SMRE) technique is proposed, which utilizes the characteristic shape and size of actual particles to remove ghost particles in the reconstructed intensity field. An assessment of SMRE is performed by a quantitative comparison of Tomo-PIV simulation results and DNS data, together with a comparison to Tomo-PIV experimental data measured in a turbulent channel flow at a matched Reynolds number (Re τ = 937) to the DNS study. For the simulation data, a comparative study is performed on the reconstruction quality based on an ideal reconstruction determined from known particle positions. The results suggest that a significant improvement in the reconstruction quality and flow statistics is achievable at typical seeding densities used in Tomo-PIV experiments. This improvement is further amplified at higher seeding densities, enabling the use of up to twice the typical seeding densities currently used in Tomo-PIV experiments. A reduction of spurious vectors present in the velocity field is also observed based on a median outlier detection criterion. The application of SMRE to Tomo-PIV experimental data shows an improvement in flow statistics, comparable to the improvement seen in simulations. Finally, due to the non-iterative nature of SMRE, the increase in processing time is marginal since only a single pass of the reconstruction algorithm is required. (paper)

  13. Elimination of ghost images in the response of PHASAR-demultiplexers

    NARCIS (Netherlands)

    Dam, van C.; Staring, A.A.M.; Jansen, E.J.; Binsma, J.J.M.; Dongen, van T.; Smit, M.K.; Verbeek, B.H.

    1997-01-01

    In this paper the occurrence of first-order modes in the performance of phased-array demultiplexers is investigated. It is found that they cause "ghost" images, which can be circumvented by optimising waveguide junctions

  14. "Haunting experiences: Ghosts in contemporary folklore," by Diane E. Goldstein et al.

    Directory of Open Access Journals (Sweden)

    Linda Levitt

    2010-03-01

    Full Text Available Diane E. Goldstein, Sylvia Ann Grider, and Jeannie Banks Thomas. Haunting experiences: Ghosts in contemporary folklore. Logan: Utah State University Press, 2007, paperback, $24.95 (272p ISBN 978-0-87421-636-3.

  15. Debris Likelihood, based on GhostNet, NASA Aqua MODIS, and GOES Imager, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Debris Likelihood Index (Estimated) is calculated from GhostNet, NASA Aqua MODIS Chl a and NOAA GOES Imager SST data. THIS IS AN EXPERIMENTAL PRODUCT: intended...

  16. Analysis of Generalized Ghost Dark Energy in LQC and Galileon Gravity

    International Nuclear Information System (INIS)

    Biswas, Mahasweta; Debnath, Ujjal

    2016-01-01

    A so-called ghost dark energy was recently proposed to explain the present acceleration of the universe. The energy density of ghost dark energy, which originates from Veneziano ghost of Quantum Chromodynamics (QCD), in a time dependent background, can be written in the form, ρ_D = (αH + βH"2) where H is the Hubble parameter. We investigate the generalized ghost dark energy (GGDE) model in the setup of loop quantum Cosmology (LQC) and Galileon Cosmology. We study the cosmological implications of the models. We also obtain the equation of state and the deceleration parameters and differential equations governing the evolution of this dark energy model for LQC and Galileon Cosmology. (paper)

  17. A review of ghost gear entanglement amongst marine mammals, reptiles and elasmobranchs.

    Science.gov (United States)

    Stelfox, Martin; Hudgins, Jillian; Sweet, Michael

    2016-10-15

    This review focuses on the effect that ghost gear entanglement has on marine megafauna, namely mammals, reptiles and elasmobranchs. A total of 76 publications and other sources of grey literature were assessed, and these highlighted that over 5400 individuals from 40 different species were recorded as entangled in, or associated with, ghost gear. Interestingly, there appeared to be a deficit of research in the Indian, Southern, and Arctic Oceans; and so, we recommend that future studies focus efforts on these areas. Furthermore, studies assessing the effects of ghost gear on elasmobranchs, manatees, and dugongs should also be prioritised, as these groups were underrepresented in the current literature. The development of regional databases, capable of recording entanglement incidences following a minimum global set of criteria, would be a logical next step in order to analyse the effect that ghost gear has on megafauna populations worldwide. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

  18. Metastatic ghost cell odontogenic carcinoma: description of a case and search for actionable targets

    Directory of Open Access Journals (Sweden)

    Maximilien J. Rappaport

    2015-09-01

    Full Text Available Ghost cell odontogenic carcinoma (GCOC is an exceedingly rare malignant tumor on the spectrum of already uncommon odontogenic or dentinogenic tumors. We describe here the case of metastatic GCOC in a patient with a history of recurrent dentinogenic ghost cell tumor of the mandible, now presenting with bilateral pleural effusions. We will discuss typical histopathologic and histochemical features of GCOC, along with results of genomic testing and their role in directing therapy.

  19. Spontaneous breaking of Lorentz symmetry by ghost condensation in perturbative quantum gravity

    Science.gov (United States)

    Faizal, Mir

    2011-10-01

    In this paper, we will study the spontaneous breakdown of the Lorentz symmetry by ghost condensation in perturbative quantum gravity. Our analysis will be done in the Curci-Ferrari gauge. We will also analyse the modification of the BRST and anti-BRST transformations by the formation of this ghost condensate. It will be shown that even though the modified BRST and anti-BRST transformations are not nilpotent, their nilpotency is restored on-shell.

  20. The hunters of humanity: creatures of horror in M. R. James's ghost stories

    OpenAIRE

    Oryshchuk, Nataliya

    2017-01-01

    In his ghost stories, M.R. James disclosed the most irrational and fearful aspects of archaic demonology still haunting the modern world. He turns humans into prey species, hunted and haunted by repulsive insect- and spider-like demons. This paper offers a closer look at the creatures of horror and the recurrent theme of the hunt in James's ghost stories, viewing them in the context of Victorian evolutionary theories as well as traditional medieval beliefs. James's protagonists, unimaginative...

  1. Systematics, phylogeny, and taphonomy of ghost shrimps (Decapoda): a perspective from the fossil record

    Science.gov (United States)

    Klompmaker, Adiël A.

    2016-01-01

    Ghost shrimps of Callianassidae and Ctenochelidae are soft-bodied, usually heterochelous decapods representing major bioturbators of muddy and sandy (sub)marine substrates. Ghost shrimps have a robust fossil record spanning from the Early Cretaceous (~ 133 Ma) to the Holocene and their remains are present in most assemblages of Cenozoic decapod crustaceans. Their taxonomic interpretation is in flux, mainly because the generic assignment is hindered by their insufficient preservation and disagreement in the biological classification. Furthermore, numerous taxa are incorrectly classified within the catch-all taxon Callianassa. To show the historical patterns in describing fossil ghost shrimps and to evaluate taphonomic aspects influencing the attribution of ghost shrimp remains to higher level taxa, a database of all fossil species treated at some time as belonging to the group has been compiled: 250 / 274 species are considered valid ghost shrimp taxa herein. More than half of these taxa (160 species, 58.4%) are known only from distal cheliped elements, i.e., dactylus and / or propodus, due to the more calcified cuticle locally. Rarely, ghost shrimps are preserved in situ in burrows or in direct association with them, and several previously unpublished occurrences are reported herein. For generic assignment, fossil material should be compared to living species because many of them have modern relatives. Heterochely, intraspecific variation, ontogenetic changes and sexual dimorphism are all factors that have to be taken into account when working with fossil ghost shrimps. Distal elements are usually more variable than proximal ones. Preliminary results suggest that the ghost shrimp clade emerged not before the Hauterivian (~ 133 Ma). The divergence of Ctenochelidae and Paracalliacinae is estimated to occur within the interval of Hauterivian to Albian (133–100 Ma). Callichirinae and Eucalliacinae likely diverged later during the Late Cretaceous (100–66 Ma

  2. Comparative studies on osmosis based encapsulation of sodium diclofenac in porcine and outdated human erythrocyte ghosts.

    Science.gov (United States)

    Bukara, Katarina; Drvenica, Ivana; Ilić, Vesna; Stančić, Ana; Mišić, Danijela; Vasić, Borislav; Gajić, Radoš; Vučetić, Dušan; Kiekens, Filip; Bugarski, Branko

    2016-12-20

    The objective of our study was to develop controlled drug delivery system based on erythrocyte ghosts for amphiphilic compound sodium diclofenac considering the differences between erythrocytes derived from two readily available materials - porcine slaughterhouse and outdated transfusion human blood. Starting erythrocytes, empty erythrocyte ghosts and diclofenac loaded ghosts were compared in terms of the encapsulation efficiency, drug releasing profiles, size distribution, surface charge, conductivity, surface roughness and morphology. The encapsulation of sodium diclofenac was performed by an osmosis based process - gradual hemolysis. During this process sodium diclofenac exerted mild and delayed antihemolytic effect and increased potassium efflux in porcine but not in outdated human erythrocytes. FTIR spectra revealed lack of any membrane lipid disorder and chemical reaction with sodium diclofenac in encapsulated ghosts. Outdated human erythrocyte ghosts with detected nanoscale damages and reduced ability to shrink had encapsulation efficiency of only 8%. On the other hand, porcine erythrocyte ghosts had encapsulation efficiency of 37% and relatively slow drug release rate. More preserved structure and functional properties of porcine erythrocytes related to their superior encapsulation and release performances, define them as more appropriate for the usage in sodium diclofenac encapsulation process. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Ghost imaging and its visibility with partially coherent elliptical Gaussian Schell-model beams

    International Nuclear Information System (INIS)

    Luo, Meilan; Zhu, Weiting; Zhao, Daomu

    2015-01-01

    The performances of the ghost image and the visibility with partially coherent elliptical Gaussian Schell-model beams have been studied. In that case we have derived the condition under which the goal ghost image is achievable. Furthermore, the visibility is assessed in terms of the parameters related to the source to find that the visibility reduces with the increase of the beam size, while it is a monotonic increasing function of the transverse coherence length. More specifically, it is found that the inequalities of the source sizes in x and y directions, as well as the transverse coherence lengths, play an important role in the ghost image and the visibility. - Highlights: • We studied the ghost image and visibility with partially coherent EGSM beams. • We derived the condition under which the goal ghost image is achievable. • The visibility is assessed in terms of the parameters related to the source. • The source sizes and coherence lengths play role in the ghost image and visibility.

  4. An improved ghost-cell immersed boundary method for compressible flow simulations

    KAUST Repository

    Chi, Cheng

    2016-05-20

    This study presents an improved ghost-cell immersed boundary approach to represent a solid body in compressible flow simulations. In contrast to the commonly used approaches, in the present work ghost cells are mirrored through the boundary described using a level-set method to farther image points, incorporating a higher-order extra/interpolation scheme for the ghost cell values. A sensor is introduced to deal with image points near the discontinuities in the flow field. Adaptive mesh refinement (AMR) is used to improve the representation of the geometry efficiently in the Cartesian grid system. The improved ghost-cell method is validated against four test cases: (a) double Mach reflections on a ramp, (b) smooth Prandtl-Meyer expansion flows, (c) supersonic flows in a wind tunnel with a forward-facing step, and (d) supersonic flows over a circular cylinder. It is demonstrated that the improved ghost-cell method can reach the accuracy of second order in L1 norm and higher than first order in L∞ norm. Direct comparisons against the cut-cell method demonstrate that the improved ghost-cell method is almost equally accurate with better efficiency for boundary representation in high-fidelity compressible flow simulations. Copyright © 2016 John Wiley & Sons, Ltd.

  5. Delayed transitions in non-linear replicator networks: About ghosts and hypercycles

    International Nuclear Information System (INIS)

    Sardanyes, Josep; Sole, Ricard V.

    2007-01-01

    In this paper we analyze delayed transition phenomena associated to extinction thresholds in a mean field model for hypercycles composed of three and four units, respectively. Hence, we extend a previous analysis carried out with the two-membered hypercycle [see Sardanyes J, Sole RV. Ghosts in the origins of life? Int J Bifurcation Chaos 2006;16(9), in press]. The models we analyze show that, after the tangent bifurcation, these hypercycles also leave a ghost in phase space. These ghosts, which actually conserve the dynamical properties of the coalesced coexistence fixed point, delay the flows before hypercycle extinction. In contrast with the two-component hypercycle, both ghosts show a plateau in the delay as φ → 0, thus displacing the power-law dependence to higher values of φ, in which the scaling law is now given by τ ∼ φ β , with β = -1/3 (where τ is the delay and φ = ε - ε c , the parametric distance above the extinction bifurcation point). These results suggest that the presence of the ghost is a general property of hypercycles. Such ghosts actually cause a memory effect which might increase hypercycle survival chances in fluctuating environments

  6. Geometrical theory of ghost and Higgs fields and SU(2/1)

    International Nuclear Information System (INIS)

    Ne'eman, Y.; Thierry-Mieg, J.

    1979-10-01

    That a Principal Fiber Bundle provides a precise geometrical representation of Yang-Mills gauge theories has been known since 1963 and used since 1975. This work presents an entirely new domain of applications. The Feynman-DeWitt-Fadeev-Popov ghost-fields required in the renormalization procedure are identified with geometrical objects in the Principal Bundle. This procedure directly yields the BRS equations guaranteeing unitarity and Slavnov-Taylor invariance of the quantum effective Lagrangian. Except for one ghost field and its variation, this entire symmetry thus corresponds to classical notions, in that it is geometrical, and completely independent of the gauge-fixing procedure, which determines the quantized Lagrangian. These results may be used to fix the signs associated with the various ghost loops of quantum supergravity. The result is based upon the identification of a geometrical Z(2) x Z(2) double-gradation of the generalized fields in supergravity: [physical/ghost] fields and [integer/half integer] spins. Then the case of a supergroup as an internal symmetry gauge is considered. Ghosts geometrically associated to odd generators may be identified with the Goldstone-Nambu Higgs-Kibble scalar fields of conventional models with spontaneous symmetry breakdown. As an example, the chiral SU(3)/sub L/ x SU(3)/sub R/ flavor symmetry is realized by gauging the supergroup Q(3).Lastly, the main results concerning asthenodynamics (Weak-EM Unification) as given by the ghost-gauge SU(2/1) supergroup are recalled. 1 table

  7. Vaginal rejuvenation using energy-based devices

    Directory of Open Access Journals (Sweden)

    Cheryl Karcher, MD

    2016-09-01

    Full Text Available Physiologic changes in a woman’s life, such as childbirth, weight fluctuations, and hormonal changes due to aging and menopause, may alter the laxity of the vaginal canal, damage the pelvic floor, and devitalize the mucosal tone of the vaginal wall. These events often lead to the development of genitourinary conditions such as stress urinary incontinence; vaginal atrophy; dryness; and physiologic distress affecting a woman’s quality of life, self-confidence, and sexuality. Various treatment modalities are currently available to manage these indications, varying from invasive vaginal surgery to more benign treatments like topical vaginal hormonal gels or hormone-replacement therapy. A new trend gaining momentum is the advent of energy-based devices for vaginal rejuvenation that apply thermal or nonthermal energy to the various layers of the vaginal tissue, stimulating collagen regeneration contracture of elastin fibers, neovascularization, and improved vaginal lubrication. This review aims to present the available technologies offering vaginal rejuvenation and the scientific evidence that underlines their safety and efficacy for this indication.

  8. The ghost of Afrikaner identity in Ancestral voices, Leap year and The long silence of Mario Salviati (Etienne van Heerden

    Directory of Open Access Journals (Sweden)

    Mariëtte van Graan

    2017-04-01

    Full Text Available Ghost characters are a characteristic of the novels of Etienne van Heerden, but little research has been done concerning the nature and function of these ghost characters. In this article I discuss Van Heerden’s use of ghost characters diachronically with reference to the novels Ancestral voices (1986, Leap year (1993 and The long silence of Mario Salviati (2000. In order to clarify the nature of these ghosts, I use the so-called science of the paranormal as a framework. The ghosts in the three novels will be classified accordingly, and then discussed within the context of the novels in which they appear. In this way, I shall show how the ghost characters in these novels can be read as a constantly changing embodiment of Afrikaner identity (a central theme in Van Heerden’s oeuvre. Van Heerden’s Afrikaner changes with the times: in Ancestral voices the ghost characters form a collective that represents a fragmented image of the stereotypical, archaic male Afrikaner identity; in Leap year a liminal character is written in a liminal time to embody a liminal Afrikaner identity; and in The long silence of Mario Salviati Van Heerden moves away from the exclusive Afrikaner identity to a broader South African identity by using ghost characters from very different backgrounds and origins. In conclusion I shall compare these identities and the historical contexts of these novels in order to show the function of Van Heerden’s ghost characters as constant rewritings of South African identities.

  9. The Ghosts of Justice and the Law of Historical Memory

    Directory of Open Access Journals (Sweden)

    Mónica López Lerma

    2011-04-01

    representational practices (words, images, expressions that seek to do justice to the victims, with unequal success. The novel’s recurring expressions (i.e., shadows, the repressed, eternal return, ghosts, and blindness stress the importance of coming to terms with the “ghosts of the past.” The law focuses instead on other words and images (i.e., foundation, reconciliation, concord, and closure that allude to the idea of historical progress, it will be argued, without proper acknowledgment of the injustices of the past. In doing so, the law becomes a commemorative site for the Spanish Transition, but not for the recovery of the victims’ memory. The law’s re-appropriation of the “spirit of the Transition” reveals Spain’s deep fear of confronting the ghosts of the past, a fear that can be perceived still today.

  10. Effects of ghost shrimp on zinc and cadmium in sediments from Tampa Bay, FL

    Science.gov (United States)

    Klerks, P.L.; Felder, D.L.; Strasser, K.; Swarzenski, P.W.

    2007-01-01

    This study investigated the effects that ghost shrimp have on the distribution of metals in sediment. We measured levels of HNO3-extractable zinc and cadmium in surface sediment, in ghost shrimp burrow walls and in sediment ejected by the ghost shrimp from their burrows, at five sandy intertidal sites in Tampa Bay. Ghost shrimp densities and their rate of sediment ejection were also quantified, as were sediment organic content and silt + clay content. Densities of ghost shrimp (Sergio trilobata and Lepidophthalmus louisianensis) averaged 33/m2 at our sites, and they ejected sediment at an average rate of 28 g/burrow/day. Levels of both Zn and Cd were significantly higher in burrow walls than in surface sediments. Sediment ejected by the shrimp from their burrows had elevated levels of Zn (relative to surface sediments) at one of the sites. Sediment organic content and silt + clay content were higher in burrow-wall sediments than in ejected sediment, which in turn tended to have values above those of surface sediments. Differences in levels of HNO3-extractable Zn and Cd among sediment types may be a consequence of these sediments differing in other physiochemical characteristics, though the differences in metal levels remained statistically significant for some sites after correcting for differences in organic content and silt + clay content. We conclude that the presence of ghost shrimp burrows contributes to spatial heterogeneity of sedimentary metal levels, while the ghost shrimp bioturbation results in a significant flux of metals to the sediment surface and is expected to decrease heterogeneity of metal levels in sedimentary depth profiles.

  11. GHOSTS I: A new faint very isolated dwarf galaxy at D = 12 ± 2 Mpc

    International Nuclear Information System (INIS)

    Monachesi, Antonela; Bell, Eric F.; Radburn-Smith, David J.; Dalcanton, Julianne J.; De Jong, Roelof S.; Streich, David; Vlajić, Marija; Bailin, Jeremy; Holwerda, Benne W.; Alyson Ford, H.; Zucker, Daniel B.

    2014-01-01

    We report the discovery of a new faint dwarf galaxy, GHOSTS I, using HST/ACS data from one of our GHOSTS (Galaxy Halos, Outer disks, Substructure, Thick disk, and Star clusters) fields. Its detected individual stars populate an approximately 1 mag range of its luminosity function (LF). Using synthetic color-magnitude diagrams (CMDs) to compare with the galaxy's CMD, we find that the colors and magnitudes of GHOSTS I's individual stars are most consistent with being young helium-burning and asymptotic giant branch stars at a distance of ∼12 ± 2 Mpc. Morphologically, GHOSTS I appears to be actively forming stars, so we tentatively classify it as a dwarf irregular (dIrr) galaxy, although future Hubble Space Telescope (HST) observations deep enough to resolve a larger magnitude range in its LF are required to make a more secure classification. GHOSTS I's absolute magnitude is M V ∼−9.85 −0.33 +0.40 , making it one of the least luminous dIrr galaxies known, and its metallicity is lower than [Fe/H] = –1.5 dex. The half-light radius of GHOSTS I is 226 ± 38 pc and its ellipticity is 0.47 ± 0.07, similar to Milky Way and M31 dwarf satellites at comparable luminosity. There are no luminous massive galaxies or galaxy clusters within ∼4 Mpc from GHOSTS I that could be considered as its host, making it a very isolated dwarf galaxy in the local universe.

  12. Identification of ghost artifact using texture analysis in pediatric spinal cord diffusion tensor images.

    Science.gov (United States)

    Alizadeh, Mahdi; Conklin, Chris J; Middleton, Devon M; Shah, Pallav; Saksena, Sona; Krisa, Laura; Finsterbusch, Jürgen; Faro, Scott H; Mulcahey, M J; Mohamed, Feroze B

    2018-04-01

    Ghost artifacts are a major contributor to degradation of spinal cord diffusion tensor images. A multi-stage post-processing pipeline was designed, implemented and validated to automatically remove ghost artifacts arising from reduced field of view diffusion tensor imaging (DTI) of the pediatric spinal cord. A total of 12 pediatric subjects including 7 healthy subjects (mean age=11.34years) with no evidence of spinal cord injury or pathology and 5 patients (mean age=10.96years) with cervical spinal cord injury were studied. Ghost/true cords, labeled as region of interests (ROIs), in non-diffusion weighted b0 images were segmented automatically using mathematical morphological processing. Initially, 21 texture features were extracted from each segmented ROI including 5 first-order features based on the histogram of the image (mean, variance, skewness, kurtosis and entropy) and 16s-order feature vector elements, incorporating four statistical measures (contrast, correlation, homogeneity and energy) calculated from co-occurrence matrices in directions of 0°, 45°, 90° and 135°. Next, ten features with a high value of mutual information (MI) relative to the pre-defined target class and within the features were selected as final features which were input to a trained classifier (adaptive neuro-fuzzy interface system) to separate the true cord from the ghost cord. The implemented pipeline was successfully able to separate the ghost artifacts from true cord structures. The results obtained from the classifier showed a sensitivity of 91%, specificity of 79%, and accuracy of 84% in separating the true cord from ghost artifacts. The results show that the proposed method is promising for the automatic detection of ghost cords present in DTI images of the spinal cord. This step is crucial towards development of accurate, automatic DTI spinal cord post processing pipelines. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Giant wormholes in ghost-free bigravity theory

    Energy Technology Data Exchange (ETDEWEB)

    Sushkov, Sergey V.; Volkov, Mikhail S., E-mail: sergey_sushkov@mail.ru, E-mail: volkov@lmpt.univ-tours.fr [Department of General Relativity and Gravitation, Institute of Physics, Kazan Federal University, Kremlevskaya street 18, 420008 Kazan (Russian Federation)

    2015-06-01

    We study Lorentzian wormholes in the ghost-free bigravity theory described by two metrics, g and f. Wormholes can exist if only the null energy condition is violated, which happens naturally in the bigravity theory since the graviton energy-momentum tensors do not apriori fulfill any energy conditions. As a result, the field equations admit solutions describing wormholes whose throat size is typically of the order of the inverse graviton mass. Hence, they are as large as the universe, so that in principle we might all live in a giant wormhole. The wormholes can be of two different types that we call W1 and W2. The W1 wormholes interpolate between the AdS spaces and have Killing horizons shielding the throat. The Fierz-Pauli graviton mass for these solutions becomes imaginary in the AdS zone, hence the gravitons behave as tachyons, but since the Breitenlohner-Freedman bound is fulfilled, there should be no tachyon instability. For the W2 wormholes the g-geometry is globally regular and in the far field zone it becomes the AdS up to subleading terms, its throat can be traversed by timelike geodesics, while the f-geometry has a completely different structure and is not geodesically complete. There is no evidence of tachyons for these solutions, although a detailed stability analysis remains an open issue. It is possible that the solutions may admit a holographic interpretation.

  14. Giant wormholes in ghost-free bigravity theory

    Energy Technology Data Exchange (ETDEWEB)

    Sushkov, Sergey V. [Department of General Relativity and Gravitation, Institute of Physics,Kazan Federal University, Kremlevskaya street 18, 420008 Kazan (Russian Federation); Volkov, Mikhail S. [Department of General Relativity and Gravitation, Institute of Physics,Kazan Federal University, Kremlevskaya street 18, 420008 Kazan (Russian Federation); Laboratoire de Mathématiques et Physique Théorique CNRS-UMR 7350, Université de Tours, Parc de Grandmont, 37200 Tours (France)

    2015-06-09

    We study Lorentzian wormholes in the ghost-free bigravity theory described by two metrics, g and f. Wormholes can exist if only the null energy condition is violated, which happens naturally in the bigravity theory since the graviton energy-momentum tensors do not apriori fulfill any energy conditions. As a result, the field equations admit solutions describing wormholes whose throat size is typically of the order of the inverse graviton mass. Hence, they are as large as the universe, so that in principle we might all live in a giant wormhole. The wormholes can be of two different types that we call W1 and W2. The W1 wormholes interpolate between the AdS spaces and have Killing horizons shielding the throat. The Fierz-Pauli graviton mass for these solutions becomes imaginary in the AdS zone, hence the gravitons behave as tachyons, but since the Breitenlohner-Freedman bound is fulfilled, there should be no tachyon instability. For the W2 wormholes the g-geometry is globally regular and in the far field zone it becomes the AdS up to subleading terms, its throat can be traversed by timelike geodesics, while the f-geometry has a completely different structure and is not geodesically complete. There is no evidence of tachyons for these solutions, although a detailed stability analysis remains an open issue. It is possible that the solutions may admit a holographic interpretation.

  15. Sponge-Like: A New Protocol for Preparing Bacterial Ghosts

    Directory of Open Access Journals (Sweden)

    Amro A. Amara

    2013-01-01

    Full Text Available Bacterial Ghosts (BGs received an increasing interest in the recent years for their promising medicinal and pharmaceutical applications. In this study, for the first time we introduce a new protocol for BGs production. E. coli BL21 (DE3 pLysS (Promega was used as a model to establish a general protocol for BGs preparation. The protocol is based on using active chemical compounds in concentrations less than the Minimum Inhibition Concentration (MIC. Those chemical compounds are SDS, NaOH, and H2O2. Plackett-Burman experimental design was used to map the best conditions for BGs production. Normal and electronic microscopes were used to evaluate the BGs quality (BGQ. Spectrophotometer was used to evaluate the amount of the released protein and DNA. Agarose gel electrophoresis was used to determine the existence of any residue of DNA after each BGs preparation. Viable cells, which existed after running this protocol, were subjected to lysis by inducing the lysozyme gene carried on pLysS plasmid. This protocol is able to produce BGs that can be used in different biotechnological applications.

  16. Characterization of Chemically-Induced Bacterial Ghosts (BGs Using Sodium Hydroxide-Induced Vibrio parahaemolyticus Ghosts (VPGs

    Directory of Open Access Journals (Sweden)

    Hyun Jung Park

    2016-11-01

    Full Text Available Acellular bacterial ghosts (BGs are empty non-living bacterial cell envelopes, commonly generated by controlled expression of the cloned lysis gene E of bacteriophage PhiX174. In this study, Vibrio parahaemolyticus ghosts (VPGs were generated by chemically-induced lysis and the method is based on minimum inhibitory concentration (MIC of sodium hydroxide (NaOH, acetic acid, boric acid, citric acid, maleic acid, hydrochloric acid, and sulfuric acid. The MIC values of the respective chemicals were 3.125, 6.25, <50.0, 25.0, 6.25, 1.56, and 0.781 mg/mL. Except for boric acid, the lysis efficiency reached more than 99.99% at 5 min after treatment of all chemicals. Among those chemicals, NaOH-induced VPGs appeared completely DNA-free, which was confirmed by quantitative real-time PCR. Besides, lipopolysaccharides (LPS extracted from the NaOH-induced VPGs showed no distinctive band on SDS-PAGE gel after silver staining. On the other hand, LPS extracted from wild-type bacterial cells, as well as the organic acids-induced VPGs showed triple major bands and LPS extracted from the inorganic acids-induced VPGs showed double bands. It suggests that some surface structures in LPS of the NaOH-induced VPGs may be lost, weakened, or modified by the MIC of NaOH. Nevertheless, Limulus amoebocyte lysate assay revealed that there is no significant difference in endotoxic activity between the NaOH-induced VPGs and wild-type bacterial cells. Macrophages exposed to the NaOH-induced VPGs at 0.5 × 106 CFU/mL showed cell viability of 97.9%, however, the MIC of NaOH did not reduce the cytotoxic effect of wild-type bacterial cells. Like Escherichia coli LPS, the NaOH-induced VPGs are an excellent activator of pro-inflammatory cytokines (IL-1β and iNOS, anti-inflammatory cytokine (IL-10, and dual activities (IL-6 in the stimulated macrophage cells. On the other hand, the induction of TNF-α mRNA was remarkable in the macrophages exposed with wild-type cells. Scanning

  17. Ghosts in high dimensional non-linear dynamical systems: The example of the hypercycle

    International Nuclear Information System (INIS)

    Sardanyes, Josep

    2009-01-01

    Ghost-induced delayed transitions are analyzed in high dimensional non-linear dynamical systems by means of the hypercycle model. The hypercycle is a network of catalytically-coupled self-replicating RNA-like macromolecules, and has been suggested to be involved in the transition from non-living to living matter in the context of earlier prebiotic evolution. It is demonstrated that, in the vicinity of the saddle-node bifurcation for symmetric hypercycles, the persistence time before extinction, T ε , tends to infinity as n→∞ (being n the number of units of the hypercycle), thus suggesting that the increase in the number of hypercycle units involves a longer resilient time before extinction because of the ghost. Furthermore, by means of numerical analysis the dynamics of three large hypercycle networks is also studied, focusing in their extinction dynamics associated to the ghosts. Such networks allow to explore the properties of the ghosts living in high dimensional phase space with n = 5, n = 10 and n = 15 dimensions. These hypercyclic networks, in agreement with other works, are shown to exhibit self-maintained oscillations governed by stable limit cycles. The bifurcation scenarios for these hypercycles are analyzed, as well as the effect of the phase space dimensionality in the delayed transition phenomena and in the scaling properties of the ghosts near bifurcation threshold

  18. Ghost cells in pilomatrixoma, craniopharyngioma, and calcifying cystic odontogenic tumor: histological, immunohistochemical, and ultrastructural study.

    Science.gov (United States)

    Rumayor, Alicia; Carlos, Román; Kirsch, Hernán Molina; de Andrade, Bruno A Benevenuto; Romañach, Mario J; de Almeida, Oslei Paes

    2015-04-01

    Pilomatrixoma, craniopharyngioma, and calcifying cystic odontogenic tumor are the main entities presenting ghost cells as an important histological feature, in spite their quite different clinical presentation; it seems that they share a common pathway in the formation of these cells. The aim of this study is to examine and compare the characteristics of ghost and other cells that form these lesions. Forty-three cases including 21 pilomatrixomas, 14 craniopharyngiomas, and eight calcifying cystic odontogenic tumors were evaluated by immunohistochemistry for cytokeratins, CD138, β-catenin, D2-40, Glut-1, FAS, CD10 and also by scanning electron microscopy. The CKs, CD138, β-catenin, Glut-1, FAS, and CD10 were more often expressed by transitional cells of craniopharyngioma and calcifying cystic odontogenic tumor, compared with pilomatrixoma. Basaloid cells of pilomatrixoma showed strong positivity for CD138 and CD10. Differences on expression pattern were identified in transitional and basal cells, as ghost cells were negative for most antibodies used, except by low expression for cytokeratins. By scanning electron microscopy, the morphology of ghost cells were similar in their fibrillar cytoplasm, but their pattern varied from sheets in pilomatrixoma to small clusters in craniopharyngioma and calcifying cystic odontogenic tumor. Mechanisms involved in formation of ghost cells are unknown, but probably they follow different pathways as protein expression in the basal/transitional cells was not uniform in the three tumors studied. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. Ghost Spectroscopy with Classical Thermal Light Emitted by a Superluminescent Diode

    Science.gov (United States)

    Janassek, Patrick; Blumenstein, Sébastien; Elsäßer, Wolfgang

    2018-02-01

    We propose and realize the first classical ghost-imaging (GI) experiment in the frequency or wavelength domain, thus performing ghost spectroscopy using thermal light exhibiting photon bunching. The required wavelength correlations are provided by light emitted by spectrally broadband near-infrared amplified spontaneous emission of a semiconductor-based superluminescent diode. They are characterized by wavelength-resolved intensity cross-correlation measurements utilizing two-photon-absorption interferometry. Finally, a real-world spectroscopic application of this ghost spectroscopy with a classical light scheme is demonstrated in which an absorption band of trichloromethane (chloroform) at 1214 nm is reconstructed with a spectral resolution of 10 nm as a proof-of-principle experiment. This ghost-spectroscopy work fills the gap of a hitherto missing analogy between the spatial and the spectral domain in classical GI modalities, with the expectation of contributing towards a broader dissemination of correlated photon ghost modalities, hence paving the way towards more applications which exploit the favorable advantages.

  20. Correlation of the ghost and the quark in the lattice Landau gauge QCD

    International Nuclear Information System (INIS)

    Furui, Sadataka; Nakajima, Hideo

    2007-01-01

    Effects of the quark field on the ghost propagator of the lattice Landau gauge are investigated by using the unquenched SU(3) configurations produced by the MILC collaboration and compared with quenched gauge configurations of SU(2) first copy of the over relaxation gauge fixing, the parallel tempering (PT) gauge fixing and quenched SU(3) 56 4 configurations. We measure the color symmetric and the color antisymmetric ghost propagator and the Binder cumulant of the l 1 norm and the l 2 norm of color antisymmetric ghost propagators and investigate deviation from those of Gaussian distributions. In the first copy samples of quenched SU(2) we observe a large fluctuation in the Binder cumulant at the lowest momentum point. This fluctuation is reduced in the P T gauge fixed samples. The color anti-symmetric ghost propagator of quenched SU(3) configurations depends on the lattice size and is small as compared to the symmetric one in the large lattice of 56 4 . The Binder cumulant of the quenched SU(2) and the N f = 2 + 1 unquenched SU(3) are almost consistent with 3-d and 8-d Gaussian distribution, respectively. A comparison of the SU(3) unquenched configurations and quenched configurations indicates that the dynamical quarks have the effect of making color antisymmetric ghost propagator closer to the Gaussian distribution and the Kugo-Ojima color confinement parameter c closer to 1. (author)

  1. Najar or Bhut-Evil eye or ghost affliction: Gujarati views about illness causation.

    Science.gov (United States)

    Spiro, Alison M

    2005-04-01

    This paper examines the supernatural beliefs of najar (evil eye) and bhut (ghost) and their roles in illness causation in Gujarati families in Britain today. The data arose unexpectedly in an ethnography of child rearing patterns carried out in Harrow, North West London and a short period of observation in Ahmedabad, India. I used anthropological methods of participant observation and unstructured interviews, which were transcribed using pseudonyms. The study group involved 70 Hindu and Jain Gujarati households with children and the fieldwork was conducted over a period of four years. Many of the individuals studied had migrated from India to East Africa before coming to the UK in the 1970s, but maintain links with both countries through kinship ties, marriage and rituals. I set out to study the continuity of women's roles in the transmission of religious and moral values, the rituals of childhood, views about infant feeding, and parenting relationships within joint families. The beliefs of najar and bhut in poor, rural settings in India have been described, but these Gujarati beliefs in Britain have not been well documented. This study indicates that najar and bhut continue to be a concern of women in most Gujarati families in Britain today and across all socio-economic groups, not confined to those on the 'bread-line', as have been previously suggested. These beliefs align themselves with Hindu ideas of the soul and reincarnation: powerful forces residing outside the body. An understanding of these beliefs could be informative to health professionals working with Gujarati communities in the UK.

  2. How Do We Think about Death?--A Cultural Glance of Superstitious Ideas from Chinese and Western Ghost Festivals

    Science.gov (United States)

    Zhang, Wenli

    2009-01-01

    Superstitious ideas are always in people's life in spite of scientific and technological advancement. Hungry Ghost Festival in China, Halloween in some western countries and Day of the Dead in Mexico are three religious festivals which are observed every year. They reveal people's idea about ghosts and spirits after death. They also include…

  3. Schwinger-Dyson operator of Yang-Mills matrix models with ghosts and derivations of the graded shuffle algebra

    NARCIS (Netherlands)

    Krishnaswami, G.S.

    2008-01-01

    We consider large-N multi-matrix models whose action closely mimics that of Yang-Mills theory, including gauge-fixing and ghost terms. We show that the factorized Schwinger-Dyson loop equations, expressed in terms of the generating series of gluon and ghost correlations G( ), are quadratic equations

  4. Pedagogies of Hauntology in History Education: Learning to Live with the Ghosts of Disappeared Victims of War and Dictatorship

    Science.gov (United States)

    Zembylas, Michalinos

    2013-01-01

    Michalinos Zembylas examines how history education can be reconceived in terms of Jacques Derrida's notion of "hauntology," that is, as an ongoing conversation with the "ghost"--in the case of this essay, the ghosts of disappeared victims of war and dictatorship. Here, Zembylas uses hauntology as both metaphor and pedagogical methodology for…

  5. A Novel Probability Model for Suppressing Multipath Ghosts in GPR and TWI Imaging: A Numerical Study

    Directory of Open Access Journals (Sweden)

    Tan Yun-hua

    2015-10-01

    Full Text Available A novel concept for suppressing the problem of multipath ghosts in Ground Penetrating Radar (GPR and Through-Wall Imaging (TWI is presented. Ghosts (i.e., false targets mainly arise from the use of the Born or single-scattering approximations that lead to linearized imaging algorithms; however, these approximations neglect the effect of multiple scattering (or multipath between the electromagnetic wavefield and the object under investigation. In contrast to existing methods of suppressing multipath ghosts, the proposed method models for the first time the reflectivity of the probed objects as a probability function up to a normalized factor and introduces the concept of random subaperture by randomly picking up measurement locations from the entire aperture. Thus, the final radar image is a joint probability distribution that corresponds to radar images derived from multiple random subapertures. Finally, numerical experiments are used to demonstrate the performance of the proposed methodology in GPR and TWI imaging.

  6. Quantization of gauge theories with open algebra in the representation with the third ghost

    International Nuclear Information System (INIS)

    Batalin, I.A.; Kallosh, R.E.

    1983-01-01

    We suggest a modified representation of the general BRS construction, which gives in a closed form the quantization of gauge theories with open algebra. Instead of gauging the Lagrange multiplier in this representation, we have the third ghost πsup(α) which appears in the quantization procedure on equal footing with the Faddeev-Popov ghosts anti Csup(α), Csup(α). This new representation is especially convenient in the non-singular gauges of the form 1/2#betta#sub(α#betta#chi)sup(#betta#)sub(chi)sup(α), where both sub(chi)sup(α) and #betta#sub(α#betta#) may arbitrarily depend on quantum fields. In the closed algebra case, we recover the result of Nielsen, whereas for the theories with open algebra we find new ghost couplings of the form anti Csup(n)Csup(n)πsup(m), n = 1, ...; m = 0, 1, ..., n. (orig.)

  7. Hydrogen atom in a magnetic field: Ghost orbits, catastrophes, and uniform semiclassical approximations

    International Nuclear Information System (INIS)

    Main, J.; Wunner, G.

    1997-01-01

    Applying closed-orbit theory to the recurrence spectra of the hydrogen atom in a magnetic field, one can interpret most, but not all, structures semiclassically in terms of closed classical orbits. In particular, conventional closed-orbit theory fails near bifurcations of orbits where semiclassical amplitudes exhibit unphysical divergences. Here we analyze the role of ghost orbits living in complex phase space. The ghosts can explain resonance structures in the spectra of the hydrogen atom in a magnetic field at positions where no real orbits exist. For three different types of catastrophes, viz. fold, cusp, and butterfly catastrophes, we construct uniform semiclassical approximations and demonstrate that these solutions are completely determined by classical parameters of the real orbits and complex ghosts. copyright 1997 The American Physical Society

  8. A ghost-cell immersed boundary method for flow in complex geometry

    International Nuclear Information System (INIS)

    Tseng, Y.-H.; Ferziger, Joel H.

    2003-01-01

    An efficient ghost-cell immersed boundary method (GCIBM) for simulating turbulent flows in complex geometries is presented. A boundary condition is enforced through a ghost cell method. The reconstruction procedure allows systematic development of numerical schemes for treating the immersed boundary while preserving the overall second-order accuracy of the base solver. Both Dirichlet and Neumann boundary conditions can be treated. The current ghost cell treatment is both suitable for staggered and non-staggered Cartesian grids. The accuracy of the current method is validated using flow past a circular cylinder and large eddy simulation of turbulent flow over a wavy surface. Numerical results are compared with experimental data and boundary-fitted grid results. The method is further extended to an existing ocean model (MITGCM) to simulate geophysical flow over a three-dimensional bump. The method is easily implemented as evidenced by our use of several existing codes

  9. Adaptive compressive ghost imaging based on wavelet trees and sparse representation.

    Science.gov (United States)

    Yu, Wen-Kai; Li, Ming-Fei; Yao, Xu-Ri; Liu, Xue-Feng; Wu, Ling-An; Zhai, Guang-Jie

    2014-03-24

    Compressed sensing is a theory which can reconstruct an image almost perfectly with only a few measurements by finding its sparsest representation. However, the computation time consumed for large images may be a few hours or more. In this work, we both theoretically and experimentally demonstrate a method that combines the advantages of both adaptive computational ghost imaging and compressed sensing, which we call adaptive compressive ghost imaging, whereby both the reconstruction time and measurements required for any image size can be significantly reduced. The technique can be used to improve the performance of all computational ghost imaging protocols, especially when measuring ultra-weak or noisy signals, and can be extended to imaging applications at any wavelength.

  10. Are the dressed gluon and ghost propagators in the Landau gauge presently determined in the confinement regime of QCD?

    International Nuclear Information System (INIS)

    Pennington, M. R.; Wilson, D. J.

    2011-01-01

    The gluon and ghost propagators in Landau gauge QCD are investigated using the Schwinger-Dyson equation approach. Working in Euclidean spacetime, we solve for these propagators using a selection of vertex inputs, initially for the ghost equation alone and then for both propagators simultaneously. The results are shown to be highly sensitive to the choices of vertices. We favor the infrared finite ghost solution from studying the ghost equation alone where we argue for a specific unique solution. In order to solve this simultaneously with the gluon using a dressed-one-loop truncation, we find that a nontrivial full ghost-gluon vertex is required in the vanishing gluon momentum limit. The self-consistent solutions we obtain correspond to having a masslike term in the gluon propagator dressing, in agreement with similar studies supporting the long-held proposal of Cornwall.

  11. A simple approach for EPID dosimetric calibration to overcome the effect of image-lag and ghosting

    International Nuclear Information System (INIS)

    Alshanqity, Mukhtar; Duane, Simon; Nisbet, Andrew

    2012-01-01

    EPID dosimetry has known drawbacks. The main issue is that a measurable residual signal is observed after the end of irradiation for prolonged periods of time, thus making measurement difficult. We present a detailed analysis of EPID response and suggest a simple, yet accurate approach for calibration that avoids the complexity of incorporating ghosting and image-lag using the maximum integrated signal instead of the total integrated signal. This approach is linear with dose and independent of dose rate. - Highlights: ► Image-lag and ghosting effects dosimetric accuracy. ► Image-lag and ghosting result in the reduction of total integrated signal for low doses. ► Residual signal is the most significant result for the image-lag and ghosting effects. ► Image-lag and ghosting can result in under-dosing of up to 2.5%.

  12. Examining Perceived Distance and Personal Authenticity as Mediators of the Effects of Ghost-Tweeting on Parasocial Interaction.

    Science.gov (United States)

    Cohen, Elizabeth L; Tyler, William J

    2016-05-01

    A number of high-profile public figures hire ghost-tweeters to post to their social media accounts on their behalf, but no research has examined how this social media practice can affect followers' feelings of connection to the public figures. College students (n = 132) participated in an online experiment to examine the effect of ghost-tweeting practices on parasocial interaction (PSI) with social media figures. Tweet authorship (use of a ghost-tweeter or not) was manipulated. Ghost-tweeting resulted in reduced PSI. Perceptions of distance, but not personal authenticity mediated this effect. However, authenticity and distance did serially mediate the relationship between ghost-tweeting and PSI. These findings shed light on the process of PSI with celebrities and other media figures on social network sites.

  13. Formation of ghost images due to metal objects on the surface of the patient's face: A pictorial essay.

    Science.gov (United States)

    Ramos, Bárbara Couto; da Silva Izar, Bruna Raquel; Pereira, Jéssica Lourdes Costa; Souza, Priscilla Sena; Valerio, Claudia Scigliano; Tuji, Fabrício Mesquita; Manzi, Flávio Ricardo

    2016-03-01

    Panoramic radiographs are a relatively simple technique that is commonly used in all dental specialties. In panoramic radiographs, in addition to the formation of real images of metal objects, ghost images may also form, and these ghost images can hinder an accurate diagnosis and interfere with the accuracy of radiology reports. Dentists must understand the formation of these images in order to avoid making incorrect radiographic diagnoses. Therefore, the present study sought to present a study of the formation of panoramic radiograph ghost images caused by metal objects in the head and neck region of a dry skull, as well as to report a clinical case n order to warn dentists about ghost images and to raise awareness thereof. An understanding of the principles of the formation of ghost images in panoramic radiographs helps prevent incorrect diagnoses.

  14. Two-Photon Ghost Image and Interference-Diffraction

    Science.gov (United States)

    Shih, Y. H.; Sergienko, A. V.; Pittman, T. B.; Strekalov, D. V.; Klyshko, D. N.

    1996-01-01

    One of the most surprising consequences of quantum mechanics is entanglement of two or more distance particles. The two-particle entangled state was mathematically formulated by Schrodinger. Based on this unusual quantum behavior, EPR defined their 'physical reality' and then asked the question: 'Can Quantum-Mechanical Description of Physical Reality Be Considered Complete?' One may not appreciate EPR's criterion of physical reality and insist that 'no elementary quantum phenomenon is a phenomenon until it is a recorded phenomenon'. Optical spontaneous parametric down conversion (SPDC) is the most effective mechanism to generate an EPR type entangled two-photon state. In SPDC, an optical beam, called the pump, is incident on a birefringent crystal. The pump is intense enough so that nonlinear effects lead to the conversion of pump photons into pairs of photons, historically called signal and idler. Technically, the SPDC is said to be type-1 or type-2, depending on whether the signal and idler beams have parallel or orthogonal polarization. The SPDC conversion efficiency is typically on the order of 10(exp -9) to 10(exp -11), depending on the SPDC nonlinear material. The signal and idler intensities are extremely low, only single photon detection devices can register them. The quantum entanglement nature of SPDC has been demonstrated in EPR-Bohm experiments and Bell's inequality measurements. The following two experiments were recently performed in our laboratory, which are more closely related to the original 1935 EPR gedankenezperiment. The first experiment is a two-photon optical imaging type experiment, which has been named 'ghost image' by the physics community. The signal and idler beams of SPDC are sent in different directions, so that the detection of the signal and idler photons can be performed by two distant photon counting detectors. An aperture object (mask) is placed in front of the signal photon detector and illuminated by the signal beam through a

  15. Burning behavior in a poor-ventilation compartment fire - ghosting fire

    International Nuclear Information System (INIS)

    Sugawa, Osami; Kawagoe, Kunio; Oka, Yasushi

    1991-01-01

    We investigated compartment fire behavior under poor-ventilation conditions using a methyl alcohol pool fire as the source with a diameter of 30 cm set in a tight box of 2 m (W)x3 m(L)x0.6 m(H). The temperatures in the box and the fuel, gas concentrations of CO, CO 2 , and O 2 , and the fuel consumption rate were measured simultaneously. The burning fuel surface level was kept constant during the test by means of an automatic fuel supply system. It was found that the flame begun to detach from the fuel surface as the oxygen concentration decreased to about 16%, and the color changed to pale blue. The flame detached completely from the fuel and a 'ghosting flame' was observed just under the ceiling which showed a thin pale blue flame and looked line an aurora. The oxygen concentration measured in the ghosting period under the ceiling was 9-10 vol%, and CO 2 was 4.5 vol% so that the oxygen of such concentration acted as in inert gas. CO 2 gas concentration looked almost a single-layer with gradient in the upper half part in ghosting period. Temperatures in the same layer decreased after ghosting occurred with gradient. For poor-ventilated fires, air exchange rate as 1.6-2.4 times/hr was estimated in the test; the burning rate decreased finally to about 1/6 of the fuel controlled fire. It has been tacitly assumed that the flame (reaction zone) and pyrolyzing material area (fuel) exit in almost the same zone, but ghosting fire is not necessarily the case. Therefore, extinguishment of ghosting fire which may occur in an enclosure with fuel and energy rich but poor-ventilation such as a power plant will be extremely difficult. (orig.)

  16. Experimental Investigation of Quality of Lensless Ghost Imaging with Pseudo-Thermal Light

    International Nuclear Information System (INIS)

    Xia, Shen; Yan-Feng, Bai; Tao, Qin; Shen-Sheng, Han

    2008-01-01

    Factors influencing the quality of lensless ghost imaging are investigated. According to the experimental results, we find that the imaging quality is determined by the number of independent sub light sources on the imaging plane of the reference arm. A qualitative picture based on advanced wave optics is presented to explain the physics behind the experimental phenomena. The present results will be helpful to provide a basis for improving the quality of ghost imaging systems in future works. (fundamental areas of phenomenology(including applications))

  17. Influence of some DNA-alkylating drugs on thermal stability, acid and osmotic resistance of the membrane of whole human erythrocytes and their ghosts.

    Science.gov (United States)

    Ivanov, I T; Gadjeva, V

    2000-09-01

    Human erythrocytes and their resealed ghosts were alkylated under identical conditions using three groups of alkylating antitumor agents: mustards, triazenes and chloroethyl nitrosoureas. Osmotic fragility, acid resistance and thermal stability of membranes were changed only in alkylated ghosts in proportion to the concentration of the alkylating agent. All the alkylating agents decreased acid resistance in ghosts. The clinically used drugs sarcolysine, dacarbazine and lomustine all decreased osmotic fragility and thermal stability of ghost membranes depending on their lipophilicity. DM-COOH did not decrease osmotic fragility and thermal stability of ghost membranes, while NEM increased thermal stability of membranes. The preliminary but not subsequent treatment of ghosts with DM-COOH fully abolished the alkylation-induced thermal labilization of ghost membrane proteins while NEM had a partial effect only. The present study gives direct evidence that alkylating agents, having a high therapeutic activity against malignant growth, bind covalently to proteins of cellular membranes.

  18. Verification ghosts. The changing political environment of the IAEA

    International Nuclear Information System (INIS)

    Redden, K.J.

    2003-01-01

    Six years ago, Dr. Hans Blix wrote in the IAEA Bulletin of a 'general optimism about further arms control and verification.' At the time, world events warranted such a prognosis; the IAEA was riding a wave of momentum after its instrumental role in the roll-back of the South African nuclear weapons program and bringing Ukraine, Belarus, and Kazakhstan into the Nuclear Non Proliferation Treaty (NPT) as non-nuclear-weapon States. The NPT's indefinite extension was only two years old, and the most pressing challenges, while recognizable, were somewhat stagnant. Today, some tidings elicit similar optimism. The IAEA's increasing efforts to combat terrorism and the decision by Member States to depart from nearly 20 years of zero real growth budgetary policy are remarkable testaments to the Agency's adaptability and credibility in the face of new threats. And with the worldwide frenzy over terrorism and redoubled phobia of weapons of mass destruction (WMD), the Agency garners public attention now as never before. Emblematic of this recent upsurge in political attention, US President George W. Bush's annual State of the Union address in 2003 mentioned supporting the IAEA as a specific priority of his administration, the first mention of the Agency in that speech since President Eisenhower in 1961 lauded its creation under 'Atoms for Peace'. Such visibility portends a future with prospects for overcoming bureaucratic inertia and effecting significant changes to the Agency's benefit. But with that visibility has come an uncertainty about the IAEA's role in world affairs. Despite being able to resolve most benign problems more easily, the Agency must operate in an environment haunted by the non-proliferation analogue of Charles Dickens' triumvirate specters: the ghosts of verification challenges past, present and future -namely, the cessation of UN-mandated inspections in Iraq, the difficulties ensuring compliance in North Korea and Iran, and the need to maintain the IAEA

  19. Tsunami on Sanriku Coast in 1586: Orphan or Ghost Tsunami ?

    Science.gov (United States)

    Satake, K.

    2017-12-01

    , estimated that the legend existed around 1750. From the above research, the tsunami legend in Tokura is unlikely from the Peruvian earthquake. Hence the 1586 tsunami was not an orphan tsunami, but rather a ghost or fake tsunami. The legend simply mentioned about tsunami, but the tsunami heights were speculated as 1-2 m (Soloviev and Go) or 2 - 2.5 m (NOAA tsunami DB).

  20. Fourier-transform ghost imaging with pure far-field correlated thermal light

    International Nuclear Information System (INIS)

    Liu Honglin; Shen Xia; Han Shensheng; Zhu Daming

    2007-01-01

    Pure far-field correlated thermal light beams are created with phase grating, and Fourier-transform ghost imaging depending only on the far-field correlation is demonstrated experimentally. Theoretical analysis and the results of experimental investigation of this pure far-field correlated thermal light are presented. Applications which may be exploited with this imaging scheme are discussed

  1. Massive, massless and ghost modes of gravitational waves from higher-order gravity

    DEFF Research Database (Denmark)

    Bogdanos, Charalampos; Capozziello, Salvatore; De Laurentis, Mariafelicia

    We linearize the field equations for higher order theories that contain scalar invariants other than the Ricci scalar. We find that besides a massless spin-2 field (the standard graviton), the theory contains also spin-0 and spin-2 massive modes with the latter being, in general, ghost modes. Then...

  2. Ghosts, Meaning, and Faith: After-Death Communications in Bereavement Narratives

    Science.gov (United States)

    Kwilecki, Susan

    2011-01-01

    After-death communications (ADCs) are reported encounters with a deceased loved one, a contemporary type of ghost experience heralded as therapeutic in coping with bereavement. Pertinent literature generally illustrates the healing power of ADCs with brief, self-contained episodes. The functions of ADCs over the course of grief need exploration.…

  3. Perturbative Yang-Mills theory without Faddeev-Popov ghost fields

    Science.gov (United States)

    Huffel, Helmuth; Markovic, Danijel

    2018-05-01

    A modified Faddeev-Popov path integral density for the quantization of Yang-Mills theory in the Feynman gauge is discussed, where contributions of the Faddeev-Popov ghost fields are replaced by multi-point gauge field interactions. An explicit calculation to O (g2) shows the equivalence of the usual Faddeev-Popov scheme and its modified version.

  4. Strong population genetic structure and larval dispersal capability of the burrowing ghost shrimp (Neotrypaea californiensis)

    Science.gov (United States)

    The burrowing ghost shrimp, Neotrypaea californiensis, is a vital member of the estuarine benthic community. Dense populations of shrimp are found in the major estuaries of Washington and Oregon. Our study determines the genetic structure of shrimp populations in order to gain ...

  5. Observational artifacts of Nuclear Spectroscopic Telescope Array: Ghost rays and stray light

    DEFF Research Database (Denmark)

    Madsen, Kristin K.; Christensen, Finn Erland; Craig, William W.

    2017-01-01

    photons that do not undergo the focused double reflections in the optics, and we term these ghost rays. We present detailed analysis and characterization of these two components and discuss how they impact observations. Finally, we discuss how they could have been prevented and should be in future...

  6. "Walking with a Ghost": Arts-Based Research, Music Videos, and the Re-Performing Body

    Science.gov (United States)

    Taylor, Pamela G.; Wilder, Shannon O.; Helms, Kathryn R.

    2007-01-01

    In folk-rock duo Tegan and Sara's 2004 music video "Walking with a Ghost," two women face one another, mirrored images in black and white. One is dressed in black--grunge shirt, pants and boots, while the other stands barefoot in a simple white dress. The black-clad figure removes three red paper hearts from her twin's chest, leaving crimson…

  7. Phase-Sensitive Coherence and the Classical-Quantum Boundary in Ghost Imaging

    Science.gov (United States)

    Erkmen, Baris I.; Hardy, Nicholas D.; Venkatraman, Dheera; Wong, Franco N. C.; Shapiro, Jeffrey H.

    2011-01-01

    The theory of partial coherence has a long and storied history in classical statistical optics. the vast majority of this work addresses fields that are statistically stationary in time, hence their complex envelopes only have phase-insensitive correlations. The quantum optics of squeezed-state generation, however, depends on nonlinear interactions producing baseband field operators with phase-insensitive and phase-sensitive correlations. Utilizing quantum light to enhance imaging has been a topic of considerable current interest, much of it involving biphotons, i.e., streams of entangled-photon pairs. Biphotons have been employed for quantum versions of optical coherence tomography, ghost imaging, holography, and lithography. However, their seemingly quantum features have been mimicked with classical-sate light, questioning wherein lies the classical-quantum boundary. We have shown, for the case of Gaussian-state light, that this boundary is intimately connected to the theory of phase-sensitive partial coherence. Here we present that theory, contrasting it with the familiar case of phase-insensitive partial coherence, and use it to elucidate the classical-quantum boundary of ghost imaging. We show, both theoretically and experimentally, that classical phase-sensitive light produces ghost imaging most closely mimicking those obtained in biphotons, and we derived the spatial resolution, image contrast, and signal-to-noise ratio of a standoff-sensing ghost imager, taking into account target-induced speckle.

  8. Telling Ghost Stories with the Voice of an Ogre: Deleuze, Identity, and Disruptive Pedagogies

    Science.gov (United States)

    Beighton, Christian

    2017-01-01

    French philosopher Gilles Deleuze (1925-95) was something of a cult figure among his university students in the 1970s and 1980s, "telling ghost stories with the voice of an ogre" (Jaeglé, 2005:10). More recently, academic interest in the educational possibilities of his work has grown considerably in Anglophone countries. Perhaps texts…

  9. Wormhole solutions with a complex ghost scalar field and their instability

    Science.gov (United States)

    Dzhunushaliev, Vladimir; Folomeev, Vladimir; Kleihaus, Burkhard; Kunz, Jutta

    2018-01-01

    We study compact configurations with a nontrivial wormholelike spacetime topology supported by a complex ghost scalar field with a quartic self-interaction. For this case, we obtain regular asymptotically flat equilibrium solutions possessing reflection symmetry. We then show their instability with respect to linear radial perturbations.

  10. Ghost Hunting as a Means to Illustrate Scientific Methodology and Enhance Critical Thinking

    Science.gov (United States)

    Rockwell, Steven C.

    2012-01-01

    The increasing popularity of television shows featuring paranormal investigations has led to a renewed enthusiasm in ghost hunting activities, and belief in the paranormal in general. These shows typically feature a group of investigators who, while claiming to utilize proper scientifically correct methodologies, violate many core scientific…

  11. Spherical collapse of small masses in the ghost-free gravity

    International Nuclear Information System (INIS)

    Frolov, Valeri P.; Zelnikov, Andrei; Netto, Tibério de Paula

    2015-01-01

    We discuss some properties of recently proposed models of a ghost-free gravity. For this purpose we study solutions of linearized gravitational equations in the framework of such a theory. We mainly focus on the version of the ghost-free theory with the exponential modification exp (◻/μ 2 )◻ −1 of the free propagator. The following three problems are discussed: (i) gravitational field of a point mass; (ii) Penrose limit of a point source boosted to the speed of light; and (iii) spherical gravitational collapse of null fluid. For the first problem we demonstrate that it can be solved by using the method of heat kernels and obtain a solution in a spacetime with arbitrary number of dimensions. For the second problem we also find the corresponding gyraton-type solutions of the ghost-free gravitational equations for any number of dimensions. For the third problem we obtain solutions for the gravitational field for the collapse of both “thin" and “thick" spherical null shells. We demonstrate how the ghost-free modification of the gravitational equations regularize the solutions of the linearized Einstein equations and smooth out their singularities.

  12. William Wordsworth’s Danish Ghost and the Ballad that Never Was

    DEFF Research Database (Denmark)

    Jensen-Rix, Robert William

    2017-01-01

    been discussed. It is argued that the singing and harp-playing ghost is a trope for the poetic vigour that had dissipated under the demands for classical styles of poetry. More than any other piece in Lyrical Ballads, “A Fragment” points to the ancient Germanic origin of the new models for poetic...

  13. Spherical collapse of small masses in the ghost-free gravity

    Energy Technology Data Exchange (ETDEWEB)

    Frolov, Valeri P.; Zelnikov, Andrei [Theoretical Physics Institute, Department of Physics, University of Alberta,Edmonton, AB, T6G 2E1 (Canada); Netto, Tibério de Paula [Theoretical Physics Institute, Department of Physics, University of Alberta,Edmonton, AB, T6G 2E1 (Canada); Departamento de Fisica - ICE, Universidade Federal de Juiz de Fora,Campus da UFJF, CEP: 36036-900, Juiz de Fora, MG (Brazil)

    2015-06-17

    We discuss some properties of recently proposed models of a ghost-free gravity. For this purpose we study solutions of linearized gravitational equations in the framework of such a theory. We mainly focus on the version of the ghost-free theory with the exponential modification exp (◻/μ{sup 2})◻{sup −1} of the free propagator. The following three problems are discussed: (i) gravitational field of a point mass; (ii) Penrose limit of a point source boosted to the speed of light; and (iii) spherical gravitational collapse of null fluid. For the first problem we demonstrate that it can be solved by using the method of heat kernels and obtain a solution in a spacetime with arbitrary number of dimensions. For the second problem we also find the corresponding gyraton-type solutions of the ghost-free gravitational equations for any number of dimensions. For the third problem we obtain solutions for the gravitational field for the collapse of both “thin' and “thick' spherical null shells. We demonstrate how the ghost-free modification of the gravitational equations regularize the solutions of the linearized Einstein equations and smooth out their singularities.

  14. A spectre is haunting the cosmos: quantum stability of massive gravity with ghosts

    International Nuclear Information System (INIS)

    Könnig, Frank; Nersisyan, Henrik; Akrami, Yashar; Amendola, Luca; Zumalacárregui, Miguel

    2016-01-01

    Many theories of modified gravity with higher order derivatives are usually ignored because of serious problems that appear due to an additional ghost degree of freedom. Most dangerously, it causes an immediate decay of the vacuum. However, breaking Lorentz invariance can cure such abominable behavior. By analyzing a model that describes a massive graviton together with a remaining Boulware-Deser ghost mode we show that even ghostly theories of modified gravity can yield models that are viable at both classical and quantum levels and, therefore, they should not generally be ruled out. Furthermore, we identify the most dangerous quantum scattering process that has the main impact on the decay time and find differences to simple theories that only describe an ordinary scalar field and a ghost. Additionally, constraints on the parameters of the theory including some upper bounds on the Lorentz-breaking cutoff scale are presented. In particular, for a simple theory of massive gravity we find that a breaking of Lorentz invariance is allowed to happen even at scales above the Planck mass. Finally, we discuss the relevance to other theories of modified gravity.

  15. Ghost instabilities of cosmological models with vector fields nonminimally coupled to the curvature

    International Nuclear Information System (INIS)

    Himmetoglu, Burak; Peloso, Marco; Contaldi, Carlo R.

    2009-01-01

    We prove that many cosmological models characterized by vectors nonminimally coupled to the curvature (such as the Turner-Widrow mechanism for the production of magnetic fields during inflation, and models of vector inflation or vector curvaton) contain ghosts. The ghosts are associated with the longitudinal vector polarization present in these models and are found from studying the sign of the eigenvalues of the kinetic matrix for the physical perturbations. Ghosts introduce two main problems: (1) they make the theories ill defined at the quantum level in the high energy/subhorizon regime (and create serious problems for finding a well-behaved UV completion), and (2) they create an instability already at the linearized level. This happens because the eigenvalue corresponding to the ghost crosses zero during the cosmological evolution. At this point the linearized equations for the perturbations become singular (we show that this happens for all the models mentioned above). We explicitly solve the equations in the simplest cases of a vector without a vacuum expectation value in a Friedmann-Robertson-Walker geometry, and of a vector with a vacuum expectation value plus a cosmological constant, and we show that indeed the solutions of the linearized equations diverge when these equations become singular.

  16. The process of ghost-rock karstification and its role in the formation of cave systems

    Czech Academy of Sciences Publication Activity Database

    Dubois, C.; Quinif, Y.; Baele, J.-M.; Barriquand, L.; Bini, A.; Bruxelles, L.; Dandurand, G.; Havron, C.; Kaufmann, O.; Lans, B.; Maire, R.; Martin, J.; Rodet, J.; Rowberry, Matthew David; Tognini, P.; Vergari, A.

    2014-01-01

    Roč. 131, APR (2014), s. 116-148 ISSN 0012-8252 Institutional support: RVO:67985891 Keywords : chemical weathering * ghost-rock * karstification * limestone dissolution * speleogenesis Subject RIV: DE - Earth Magnetism, Geodesy, Geography Impact factor: 7.885, year: 2014 http://www.sciencedirect.com/science/article/pii/S0012825214000154

  17. Energy-Based Devices in Treatment of Acne Vulgaris.

    Science.gov (United States)

    Handler, Marc Z; Bloom, Bradley S; Goldberg, David J

    2016-05-01

    Acne vulgaris is a chronic dermatologic complaint with a multifactorial cause. Traditionally, antibiotics and retinoids have been used to manage the condition; patient compliance has been an ongoing issue. A variety of energy-based devices have been reported to be effective in the treatment of acne vulgaris. To review and summarize the current literature specific to treatment of acne vulgaris with energy-based devices. A review of the current literature of energy-based devices used for the treatment of acne vulgaris. Although limited randomized controlled trials for the treatment of acne have been performed, significant clinical improvement of acne vulgaris, especially of inflammatory lesions, has been demonstrated with a variety of energy-based devices. Newer approaches may lead to even better results.

  18. Energy-Based Acoustic Source Localization Methods: A Survey

    Directory of Open Access Journals (Sweden)

    Wei Meng

    2017-02-01

    Full Text Available Energy-based source localization is an important problem in wireless sensor networks (WSNs, which has been studied actively in the literature. Numerous localization algorithms, e.g., maximum likelihood estimation (MLE and nonlinear-least-squares (NLS methods, have been reported. In the literature, there are relevant review papers for localization in WSNs, e.g., for distance-based localization. However, not much work related to energy-based source localization is covered in the existing review papers. Energy-based methods are proposed and specially designed for a WSN due to its limited sensor capabilities. This paper aims to give a comprehensive review of these different algorithms for energy-based single and multiple source localization problems, their merits and demerits and to point out possible future research directions.

  19. Revisiting fifth forces in the Galileon model

    Energy Technology Data Exchange (ETDEWEB)

    Burrage, Clare [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Gruppe Theorie; Seery, David [Sussex Univ., Brighton (United Kingdom). Dept. of Physics and Astronomy

    2010-05-15

    A Galileon field is one which obeys a spacetime generalization of the non- relativistic Galilean invariance. Such a field may possess non-canonical kinetic terms, but ghost-free theories with a well-defined Cauchy problem exist, constructed using a finite number of relevant operators. The interactions of this scalar with matter are hidden by the Vainshtein effect, causing the Galileon to become weakly coupled near heavy sources. We revisit estimates of the fifth force mediated by a Galileon field, and show that the parameters of the model are less constrained by experiment than previously supposed. (orig.)

  20. Ghost-tree: creating hybrid-gene phylogenetic trees for diversity analyses.

    Science.gov (United States)

    Fouquier, Jennifer; Rideout, Jai Ram; Bolyen, Evan; Chase, John; Shiffer, Arron; McDonald, Daniel; Knight, Rob; Caporaso, J Gregory; Kelley, Scott T

    2016-02-24

    Fungi play critical roles in many ecosystems, cause serious diseases in plants and animals, and pose significant threats to human health and structural integrity problems in built environments. While most fungal diversity remains unknown, the development of PCR primers for the internal transcribed spacer (ITS) combined with next-generation sequencing has substantially improved our ability to profile fungal microbial diversity. Although the high sequence variability in the ITS region facilitates more accurate species identification, it also makes multiple sequence alignment and phylogenetic analysis unreliable across evolutionarily distant fungi because the sequences are hard to align accurately. To address this issue, we created ghost-tree, a bioinformatics tool that integrates sequence data from two genetic markers into a single phylogenetic tree that can be used for diversity analyses. Our approach starts with a "foundation" phylogeny based on one genetic marker whose sequences can be aligned across organisms spanning divergent taxonomic groups (e.g., fungal families). Then, "extension" phylogenies are built for more closely related organisms (e.g., fungal species or strains) using a second more rapidly evolving genetic marker. These smaller phylogenies are then grafted onto the foundation tree by mapping taxonomic names such that each corresponding foundation-tree tip would branch into its new "extension tree" child. We applied ghost-tree to graft fungal extension phylogenies derived from ITS sequences onto a foundation phylogeny derived from fungal 18S sequences. Our analysis of simulated and real fungal ITS data sets found that phylogenetic distances between fungal communities computed using ghost-tree phylogenies explained significantly more variance than non-phylogenetic distances. The phylogenetic metrics also improved our ability to distinguish small differences (effect sizes) between microbial communities, though results were similar to non

  1. New proposal for non-linear ghost-free massive F(R) gravity: Cosmic acceleration and Hamiltonian analysis

    International Nuclear Information System (INIS)

    Klusoň, Josef; Nojiri, Shin'ichi; Odintsov, Sergei D.

    2013-01-01

    We propose new version of massive F(R) gravity which is natural generalization of convenient massive ghost-free gravity. Its Hamiltonian formulation in scalar-tensor frame is developed. We show that such F(R) theory is ghost-free. The cosmological evolution of such theory is investigated. Despite the strong Bianchi identity constraint the possibility of cosmic acceleration (especially, in the presence of cold dark matter) is established. Ghost-free massive F(R,T) gravity is also proposed

  2. Two-loop ghost-antighost condensation for SU(2) Yang-Mills theories in the maximal abelian gauge

    International Nuclear Information System (INIS)

    Fazio, A.R.

    2004-01-01

    In the framework of the formalism of Cornwall et.al. for composite operators I study the ghost-antighost condensation in SU(2) Yang-Mills theories quantized in the Maximal Abelian Gauge and derive analytically a condensating effective potential at two ghost loops. I find that in this approximation the one-loop pairing ghost-antighost is not destroyed and no mass is generated if the ansatz for the propagator suggested by the tree level Hubbard-Stratonovich transformations is used

  3. Towards numerical simulations of supersonic liquid jets using ghost fluid method

    International Nuclear Information System (INIS)

    Majidi, Sahand; Afshari, Asghar

    2015-01-01

    Highlights: • A ghost fluid method based solver is developed for numerical simulation of compressible multiphase flows. • The performance of the numerical tool is validated via several benchmark problems. • Emergence of supersonic liquid jets in quiescent gaseous environment is simulated using ghost fluid method for the first time. • Bow-shock formation ahead of the liquid jet is clearly observed in the obtained numerical results. • Radiation of mach waves from the phase-interface witnessed experimentally is evidently captured in our numerical simulations. - Abstract: A computational tool based on the ghost fluid method (GFM) is developed to study supersonic liquid jets involving strong shocks and contact discontinuities with high density ratios. The solver utilizes constrained reinitialization method and is capable of switching between the exact and approximate Riemann solvers to increase the robustness. The numerical methodology is validated through several benchmark test problems; these include one-dimensional multiphase shock tube problem, shock–bubble interaction, air cavity collapse in water, and underwater-explosion. A comparison between our results and numerical and experimental observations indicate that the developed solver performs well investigating these problems. The code is then used to simulate the emergence of a supersonic liquid jet into a quiescent gaseous medium, which is the very first time to be studied by a ghost fluid method. The results of simulations are in good agreement with the experimental investigations. Also some of the famous flow characteristics, like the propagation of pressure-waves from the liquid jet interface and dependence of the Mach cone structure on the inlet Mach number, are reproduced numerically. The numerical simulations conducted here suggest that the ghost fluid method is an affordable and reliable scheme to study complicated interfacial evolutions in complex multiphase systems such as supersonic liquid

  4. A parallel implementation of the ghost-cell immersed boundary ...

    Indian Academy of Sciences (India)

    S Peter

    cylinder. Keywords. Taylor series; inverse distance weighting; Neumann boundary condition; ... Kim et al [4], for controlling the production of spurious force ..... continuously increases with a because of the Magnus effect. 7. Conclusions.

  5. “The ghost of the water’s power”: Emil Rathenau and his electrical networks in Chile and Spain

    Directory of Open Access Journals (Sweden)

    Marion Steiner

    2017-12-01

    Full Text Available In 1902, the founder of AEG in Berlin, Emil Rathenau, called water power a “ghost ... that has completed his tour around the world.” The vast majority of electrical systems his company had built at that time were based on the use of coal and, in Spain, its thermal power plants already supplied much of the cities. In Chile, on the contrary, according to contracts signed with the municipalities of Santiago and Valparaiso in 1898 and 1902, AEG was obliged to install hydroelectric systems. This article re-constructs the corresponding disputes between the company and the municipality on the use of hydraulic force in Santiago and contrasts them with the situation in Catalonia. Both cases are contextualized from a global perspective of geopolitical analysis that allows for also explaining the global network of actors involved and the strategies implemented by German electric companies and banks to conquer the world market, up to a little beyond the end of World War I.

  6. Reconstruction of Stress and Composition Profiles from X-ray Diffraction Experiments - How to Avoid Ghost Stresses?

    DEFF Research Database (Denmark)

    Christiansen, Thomas; Somers, Marcel A.J.

    2004-01-01

    On evaluating lattice strain-depth or stress-depth profiles with X-ray diffraction, the variation of the information depth while combining various tilt angles,psi, in combination with lattice spacing gradients leads to artefacts,so-called ghost or fictitious stresses. X-ray diffraction lattice...... method for the evaluation of stress/strain and composition profiles, while minimising the risk for ghost stresses....

  7. Formation of ghost images due to metal objects on the surface of the patient's face: A pictorial essay

    OpenAIRE

    Ramos, B?rbara Couto; da Silva Izar, Bruna Raquel; Pereira, J?ssica Lourdes Costa; Souza, Priscilla Sena; Valerio, Claudia Scigliano; Tuji, Fabr?cio Mesquita; Manzi, Fl?vio Ricardo

    2016-01-01

    Panoramic radiographs are a relatively simple technique that is commonly used in all dental specialties. In panoramic radiographs, in addition to the formation of real images of metal objects, ghost images may also form, and these ghost images can hinder an accurate diagnosis and interfere with the accuracy of radiology reports. Dentists must understand the formation of these images in order to avoid making incorrect radiographic diagnoses. Therefore, the present study sought to present a stu...

  8. Honorary and ghost authorship in high impact biomedical journals: a cross sectional survey.

    Science.gov (United States)

    Wislar, Joseph S; Flanagin, Annette; Fontanarosa, Phil B; Deangelis, Catherine D

    2011-10-25

    To assess the prevalence of honorary and ghost authors in six leading general medical journals in 2008 and compare this with the prevalence reported by authors of articles published in 1996. Cross sectional survey using a web based questionnaire. International survey of journal authors. Sample of corresponding authors of 896 research articles, review articles, and editorial/opinion articles published in six general medical journals with high impact factors in 2008: Annals of Internal Medicine, JAMA, Lancet, Nature Medicine, New England Journal of Medicine, and PLoS Medicine. Self reported compliance with International Committee of Medical Journal Editors (ICMJE) criteria for authorship for all authors on the selected articles. A total of 630/896 (70.3%) corresponding authors responded to the survey. The prevalence of articles with honorary authorship or ghost authorship, or both, was 21.0% (95% CI 18.0% to 24.3%), a decrease from 29.2% reported in 1996 (P = 0.004). Based on 545 responses on honorary authorship, 96 articles (17.6% (95% CI 14.6% to 21.0%)) had honorary authors (range by journal 12.2% to 29.3%), a non-significant change from 1996 (19.3%; P = 0.439). Based on 622 responses on ghost authorship, 49 articles (7.9% (6.0% to 10.3%)) had ghost authors (range by journal 2.1% to 11.0%), a significant decline from 1996 (11.5%; P = 0.023). The prevalence of honorary authorship was 25.0% in original research reports, 15.0% in reviews, and 11.2% in editorials, whereas the prevalence of ghost authorship was 11.9% in research articles, 6.0% in reviews, and 5.3% in editorials. Evidence of honorary and ghost authorship in 21% of articles published in major medical journals in 2008 suggests that increased efforts by scientific journals, individual authors, and academic institutions are essential to promote responsibility, accountability, and transparency in authorship, and to maintain integrity in scientific publication.

  9. Ghost marker detection and elimination in marker-based optical tracking systems for real-time tracking in stereotactic body radiotherapy

    International Nuclear Information System (INIS)

    Yan, Guanghua; Li, Jonathan; Huang, Yin; Mittauer, Kathryn; Lu, Bo; Liu, Chihray

    2014-01-01

    Purpose: To propose a simple model to explain the origin of ghost markers in marker-based optical tracking systems (OTS) and to develop retrospective strategies to detect and eliminate ghost markers. Methods: In marker-based OTS, ghost markers are virtual markers created due to the cross-talk between the two camera sensors, which can lead to system execution failure or inaccuracy in patient tracking. As a result, the users have to limit the number of markers and avoid certain marker configurations to reduce the chances of ghost markers. In this work, the authors propose retrospective strategies to detect and eliminate ghost markers. The two camera sensors were treated as mathematical points in space. The authors identified the coplanar within limit (CWL) condition as the necessary condition for ghost marker occurrence. A simple ghost marker detection method was proposed based on the model. Ghost marker elimination was achieved through pattern matching: a ghost marker-free reference set was matched with the optical marker set observed by the OTS; unmatched optical markers were eliminated as either ghost markers or misplaced markers. The pattern matching problem was formulated as a constraint satisfaction problem (using pairwise distances as constraints) and solved with an iterative backtracking algorithm. Wildcard markers were introduced to address missing or misplaced markers. An experiment was designed to measure the sensor positions and the limit for the CWL condition. The ghost marker detection and elimination algorithms were verified with samples collected from a five-marker jig and a nine-marker anthropomorphic phantom, rotated with the treatment couch from −60° to +60°. The accuracy of the pattern matching algorithm was further validated with marker patterns from 40 patients who underwent stereotactic body radiotherapy (SBRT). For this purpose, a synthetic optical marker pattern was created for each patient by introducing ghost markers, marker position

  10. Ghost marker detection and elimination in marker-based optical tracking systems for real-time tracking in stereotactic body radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Guanghua, E-mail: yan@ufl.edu; Li, Jonathan; Huang, Yin; Mittauer, Kathryn; Lu, Bo; Liu, Chihray [Department of Radiation Oncology, University of Florida, Gainesville, Florida 32610 (United States)

    2014-10-15

    Purpose: To propose a simple model to explain the origin of ghost markers in marker-based optical tracking systems (OTS) and to develop retrospective strategies to detect and eliminate ghost markers. Methods: In marker-based OTS, ghost markers are virtual markers created due to the cross-talk between the two camera sensors, which can lead to system execution failure or inaccuracy in patient tracking. As a result, the users have to limit the number of markers and avoid certain marker configurations to reduce the chances of ghost markers. In this work, the authors propose retrospective strategies to detect and eliminate ghost markers. The two camera sensors were treated as mathematical points in space. The authors identified the coplanar within limit (CWL) condition as the necessary condition for ghost marker occurrence. A simple ghost marker detection method was proposed based on the model. Ghost marker elimination was achieved through pattern matching: a ghost marker-free reference set was matched with the optical marker set observed by the OTS; unmatched optical markers were eliminated as either ghost markers or misplaced markers. The pattern matching problem was formulated as a constraint satisfaction problem (using pairwise distances as constraints) and solved with an iterative backtracking algorithm. Wildcard markers were introduced to address missing or misplaced markers. An experiment was designed to measure the sensor positions and the limit for the CWL condition. The ghost marker detection and elimination algorithms were verified with samples collected from a five-marker jig and a nine-marker anthropomorphic phantom, rotated with the treatment couch from −60° to +60°. The accuracy of the pattern matching algorithm was further validated with marker patterns from 40 patients who underwent stereotactic body radiotherapy (SBRT). For this purpose, a synthetic optical marker pattern was created for each patient by introducing ghost markers, marker position

  11. Some image artefacts in non-contact mode force microscopy

    International Nuclear Information System (INIS)

    Dinte, B.P.; Watson, G.S.; Dobson, J.F.; Myhra, S.

    1996-01-01

    Full text: Non-contact mode Atomic Force Microscopy (AFM), performed in air, of two-dimensional hexagonal close-packed (2DHCP) layers of 200 nm diameter polystyrene spheres yields images containing artefacts ('ghost spheres') at layer edges and vacancy sites. The origin of these artefacts is clearly not the simple convolution of the tip and sample geometries, but must be the interaction between them. A computer program was written to simulate the experimental contours, assuming that the only force between the tip and the sample is the van der Waals (dispersion) force, and that the contours traced by the AFM tip are those of constant force derivative. The energy was calculated by integrating R -6 over the volumes of the tip and the sample, with a (constant) arbitrary scaling factor. The experimental contours were reproduced by the simulations, except for the 'ghost' artefacts. The assumption that there is only a dispersion force is thus incorrect. The experiments were performed in air, so that all surfaces were coated by a layer of adsorbed moisture. It is proposed that meniscus forces may be the origin of the artefacts

  12. Comparison of ghosting effects for three commercial a-Si EPIDs

    International Nuclear Information System (INIS)

    McDermott, L. N.; Nijsten, S. M. J. J. G.; Sonke, J.-J.; Partridge, M.; Herk, M. van; Mijnheer, B. J.

    2006-01-01

    Many studies have reported dosimetric characteristics of amorphous silicon electronic portal imaging devices (EPIDs). Some studies ascribed a non-linear signal to gain ghosting and image lag. Other reports, however, state the effect is negligible. This study compares the signal-to-monitor unit (MU) ratio for three different brands of EPID systems. The signal was measured for a wide range of monitor units (5-1000), dose-rates, and beam energies. All EPIDs exhibited a relative under-response for beams of few MUs; giving 4 to 10% lower signal-to-MU ratios relative to that of 1000 MUs. This under-response is consistent with ghosting effects due to charge trapping

  13. On operators of the ghost number and conjugation in the BRST quantization formalism

    International Nuclear Information System (INIS)

    Azizov, T.Ya.; Khoruzhij, S.S.

    1989-01-01

    Detailed and rigorous study is made of operators of the ghost number Q c and ghost conjugation U c which are operators in Krein spaces arising in the BRST quantization formalism for constrained dynamical systems. A number of conditions are obtained which guarantee that Q c is well-defined and J-symmetric. It is shown that properties of Q c are related to the following geometrical problem: to find conditions under which a pair of lineals in the Krein space can be made neutral by the appropriate choice of J-metrics. The complete solution of this problem is given. Whole series of examples is constructed which demonstrate the connections between properties of Q c and geometry of its spectral subspaces

  14. Is the key of the ghost imaging mystery given by the electromagnetic crossing symmetric photon reactions?

    International Nuclear Information System (INIS)

    Rusu, L; Rusu, A

    2013-01-01

    In the ghost imaging system, the object and image are separately illuminated by a pair of correlated beams and the image is obtained through coincidence detection of the two beams. When the correlated beams are obtained by a spontaneous parametric down-conversion phenomenon, the image formation is attributed to either quantum entanglement or wave vector correlation. The physicist D B Ion has published a different point of view: the ghost imaging can be explained by electromagnetic crossing symmetric photon reactions. We report on an experimental setup to verify that a change of the object reflection coefficient modifies the idler single count rate. The obtained results are a confirmation proof and suggest the existence of a stimulated spontaneous parametric down-conversion effect. A possible application is mentioned. (paper)

  15. An Embedded Ghost-Fluid Method for Compressible Flow in Complex Geometry

    KAUST Repository

    Almarouf, Mohamad Abdulilah Alhusain Alali; Samtaney, Ravi

    2016-01-01

    We present an embedded ghost-fluid method for numerical solutions of the compressible Navier Stokes (CNS) equations in arbitrary complex domains. The PDE multidimensional extrapolation approach of Aslam [1] is used to reconstruct the solution in the ghost-fluid regions and impose boundary conditions at the fluid-solid interface. The CNS equations are numerically solved by the second order multidimensional upwind method of Colella [2] and Saltzman [3]. Block-structured adaptive mesh refinement implemented under the Chombo framework is utilized to reduce the computational cost while keeping high-resolution mesh around the embedded boundary and regions of high gradient solutions. Numerical examples with different Reynolds numbers for low and high Mach number flow will be presented. We compare our simulation results with other reported experimental and computational results. The significance and advantages of our implementation, which revolve around balancing between the solution accuracy and implementation difficulties, are briefly discussed as well. © 2016 Trans Tech Publications.

  16. Dark matter as a ghost free conformal extension of Einstein theory

    International Nuclear Information System (INIS)

    Barvinsky, A.O.

    2014-01-01

    We discuss ghost free models of the recently suggested mimetic dark matter theory. This theory is shown to be a conformal extension of Einstein general relativity. Dark matter originates from gauging out its local Weyl invariance as an extra degree of freedom which describes a potential flow of the pressureless perfect fluid. For a positive energy density of this fluid the theory is free of ghost instabilities, which gives strong preference to stable configurations with a positive scalar curvature and trace of the matter stress tensor. Instabilities caused by caustics of the geodesic flow, inherent in this model, serve as a motivation for an alternative conformal extension of Einstein theory, based on the generalized Proca vector field. A potential part of this field modifies the inflationary stage in cosmology, whereas its rotational part at the post inflationary epoch might simulate rotating flows of dark matter

  17. An Embedded Ghost-Fluid Method for Compressible Flow in Complex Geometry

    KAUST Repository

    Almarouf, Mohamad Abdulilah Alhusain Alali

    2016-06-03

    We present an embedded ghost-fluid method for numerical solutions of the compressible Navier Stokes (CNS) equations in arbitrary complex domains. The PDE multidimensional extrapolation approach of Aslam [1] is used to reconstruct the solution in the ghost-fluid regions and impose boundary conditions at the fluid-solid interface. The CNS equations are numerically solved by the second order multidimensional upwind method of Colella [2] and Saltzman [3]. Block-structured adaptive mesh refinement implemented under the Chombo framework is utilized to reduce the computational cost while keeping high-resolution mesh around the embedded boundary and regions of high gradient solutions. Numerical examples with different Reynolds numbers for low and high Mach number flow will be presented. We compare our simulation results with other reported experimental and computational results. The significance and advantages of our implementation, which revolve around balancing between the solution accuracy and implementation difficulties, are briefly discussed as well. © 2016 Trans Tech Publications.

  18. A unifying framework for ghost-free Lorentz-invariant Lagrangian field theories

    Science.gov (United States)

    Li, Wenliang

    2018-04-01

    We propose a framework for Lorentz-invariant Lagrangian field theories where Ostrogradsky's scalar ghosts could be absent. A key ingredient is the generalized Kronecker delta. The general Lagrangians are reformulated in the language of differential forms. The absence of higher order equations of motion for the scalar modes stems from the basic fact that every exact form is closed. The well-established Lagrangian theories for spin-0, spin-1, p-form, spin-2 fields have natural formulations in this framework. We also propose novel building blocks for Lagrangian field theories. Some of them are novel nonlinear derivative terms for spin-2 fields. It is nontrivial that Ostrogradsky's scalar ghosts are absent in these fully nonlinear theories.

  19. Gravity and magnetic investigations of the Ghost Dance and Solitario Canyon faults, Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Ponce, D.A.; Langenheim, V.E.

    1995-01-01

    Ground magnetic and gravity data collected along traverses across the Ghost Dance and Solitario Canyon faults on the eastern and western flanks, respectively, of Yucca Mountain in southwest Nevada are interpreted. These data were collected as part of an effort to evaluate faulting in the vicinity of a potential nuclear waste repository at Yucca Mountain. Gravity and magnetic data and models along traverses across the Ghost Dance and Solitario Canyon faults show prominent anomalies associated with known faults and reveal a number of possible concealed faults beneath the eastern flank of Yucca Mountain. The central part of the eastern flank of Yucca Mountain is characterized by several small amplitude anomalies that probably reflect small scale faulting

  20. Optical image encryption scheme with multiple light paths based on compressive ghost imaging

    Science.gov (United States)

    Zhu, Jinan; Yang, Xiulun; Meng, Xiangfeng; Wang, Yurong; Yin, Yongkai; Sun, Xiaowen; Dong, Guoyan

    2018-02-01

    An optical image encryption method with multiple light paths is proposed based on compressive ghost imaging. In the encryption process, M random phase-only masks (POMs) are generated by means of logistic map algorithm, and these masks are then uploaded to the spatial light modulator (SLM). The collimated laser light is divided into several beams by beam splitters as it passes through the SLM, and the light beams illuminate the secret images, which are converted into sparse images by discrete wavelet transform beforehand. Thus, the secret images are simultaneously encrypted into intensity vectors by ghost imaging. The distances between the SLM and secret images vary and can be used as the main keys with original POM and the logistic map algorithm coefficient in the decryption process. In the proposed method, the storage space can be significantly decreased and the security of the system can be improved. The feasibility, security and robustness of the method are further analysed through computer simulations.

  1. Effects of Low Anisotropy on Generalized Ghost Dark Energy in Galileon Gravity

    Science.gov (United States)

    Hossienkhani, H.; Fayaz, V.; Jafari, A.; Yousefi, H.

    2018-04-01

    The definition of the Galileon gravity form is extended to the Brans-Dicke theory. Given, the framework of the Galileon theory, the generalized ghost dark energy model in an anisotropic universe is investigated. We study the cosmological implications of this model. In particular, we obtain the equation of state and the deceleration parameters and a differential equation governing the evolution of this dark energy in Bianchi type I model. We also probe observational constraints by using the latest observational data on the generalized ghost dark energy models as the unification of dark matter and dark energy. In order to do so, we focus on observational determinations of the Hubble expansion rate (namely, the expansion history) H(z). As a result, we show the influence of the anisotropy (although low) on the evolution of the universe in the statefinder diagrams for Galileon gravity.

  2. Ghost-Free Massive $f(R)$ Theories Modelled as Effective Einstein Spaces and Cosmic Acceleration

    CERN Document Server

    Vacaru, Sergiu I

    2014-01-01

    We study how massive ghost-free gravity $f(R)$-modified theories, MGFTs, can be encoded into generic off-diagonal Einstein spaces. Using "auxiliary" connections completely defined by the metric fields and adapted to nonholonomic frames with associated to nonlinear connection structure, we decouple and integrate in certain general forms the field equations in MGFT. Imposing additional nonholonomic constraints, we can generate Levi--Civita, LC, configurations and mimic MGFT effects via off-diagonal interactions of effective Einstein and/or Einstein-Cartan gravity with nonholonomically induced torsion. The cosmological evolution of ghost-free off--diagonal Einstein spaces is investigated. Certain compatibility of MGFT cosmology to small off-diagonal deformations of $\\Lambda $CDM models is established. %

  3. The solar energy based global economy. A policy leading to the ecological era

    International Nuclear Information System (INIS)

    Scheer, H.

    1999-01-01

    Bound in its fossil energy and raw materials supply chains, the global economy is heading for a global ecological crisis and dramatically aggravating conflicts. Moreover, this exclusive dependence on fossil energy and materials resources forces a global concentration process increasingly undermining democratic and free market systems. But the will to survive is not the only reason to consider a new industrial revolution to be imperative. Such a sweeping change, from a fossil energy based regime to a system relying exclusively on renewable energy sources and raw materials, would open up unique opportunities for the evolution of a peaceful and democratic global economy fostering the development of superior technologies and sustainable regional economic systems. The author of the book elaborates the scenario permitting such a radical change, and explains the necessary basic approaches and appropriate policies relating to technology, the economy, ecology, and the social system. The ultimate goal is that the evolution of the solar energy based global economy will be accompanied by an intrinsic economic driving force eventually leading to an ecological era. (orig./CB) [de

  4. Human threats to sandy beaches: A meta-analysis of ghost crabs illustrates global anthropogenic impacts.

    Science.gov (United States)

    Schlacher, Thomas A.; Lucrezi, Serena; Connolly, Rod M.; Peterson, Charles H.; Gilby, Ben L.; Maslo, Brooke; Olds, Andrew D.; Walker, Simon J.; Leon, Javier X.; Huijbers, Chantal M.; Weston, Michael A.; Turra, Alexander; Hyndes, Glenn A.; Holt, Rebecca A.; Schoeman, David S.

    2016-02-01

    Beach and coastal dune systems are increasingly subjected to a broad range of anthropogenic pressures that on many shorelines require significant conservation and mitigation interventions. But these interventions require reliable data on the severity and frequency of adverse ecological impacts. Such evidence is often obtained by measuring the response of 'indicator species'. Ghost crabs are the largest invertebrates inhabiting tropical and subtropical sandy shores and are frequently used to assess human impacts on ocean beaches. Here we present the first global meta-analysis of these impacts, and analyse the design properties and metrics of studies using ghost-crabs in their assessment. This was complemented by a gap analysis to identify thematic areas of anthropogenic pressures on sandy beach ecosystems that are under-represented in the published literature. Our meta-analysis demonstrates a broad geographic reach, encompassing studies on shores of the Pacific, Indian, and Atlantic Oceans, as well as the South China Sea. It also reveals what are, arguably, two major limitations: i) the near-universal use of proxies (i.e. burrow counts to estimate abundance) at the cost of directly measuring biological traits and bio-markers in the organism itself; and ii) descriptive or correlative study designs that rarely extend beyond a simple 'compare and contrast approach', and hence fail to identify the mechanistic cause(s) of observed contrasts. Evidence for a historically narrow range of assessed pressures (i.e., chiefly urbanisation, vehicles, beach nourishment, and recreation) is juxtaposed with rich opportunities for the broader integration of ghost crabs as a model taxon in studies of disturbance and impact assessments on ocean beaches. Tangible advances will most likely occur where ghost crabs provide foci for experiments that test specific hypotheses associated with effects of chemical, light and acoustic pollution, as well as the consequences of climate change (e

  5. Ghost microscope imaging system from the perspective of coherent-mode representation

    Science.gov (United States)

    Shen, Qian; Bai, Yanfeng; Shi, Xiaohui; Nan, Suqin; Qu, Lijie; Li, Hengxing; Fu, Xiquan

    2018-03-01

    The coherent-mode representation theory of partially coherent fields is firstly used to analyze a two-arm ghost microscope imaging system. It is shown that imaging quality of the generated images depend crucially on the distribution of the decomposition coefficients of the object imaged when the light source is fixed. This theory is also suitable for demonstrating the effects from the distance the object is moved away from the original plane on imaging quality. Our results are verified theoretically and experimentally.

  6. Two-color ghost interference with photon pairs generated in hot atoms

    Directory of Open Access Journals (Sweden)

    Dong-Sheng Ding

    2012-09-01

    Full Text Available We report on an experimental observation of a two-photon ghost interference experiment. A distinguishing feature of our experiment is that the photons are generated via a non-degenerated spontaneous four-wave mixing process in a hot atomic ensemble; therefore the photon has narrow bandwidth. Besides, there is a large difference in frequency between two photons in a pair. Our works may be important to achieve more secure, large transmission capacity long-distance quantum communication.

  7. Gluon-ghost condensate of mass dimension 2 in the Curci-Ferrari gauge

    International Nuclear Information System (INIS)

    Dudal, D.; Verschelde, H.; Lemes, V.E.R.; Sarandy, M.S.; Sorella, S.P.; Picariello, M.

    2003-01-01

    The effective potential for an on-shell BRST invariant gluon-ghost condensate of mass dimension 2 in the Curci-Ferrari gauge in SU(N) Yang-Mills is analysed by combining the local composite operator technique with the algebraic renormalization. We pay attention to the gauge parameter independence of the vacuum energy obtained in the considered framework and discuss the Landau gauge as an interesting special case

  8. Objective lens simultaneously optimized for pupil ghosting, wavefront delivery and pupil imaging

    Science.gov (United States)

    Olczak, Eugene G (Inventor)

    2011-01-01

    An objective lens includes multiple optical elements disposed between a first end and a second end, each optical element oriented along an optical axis. Each optical surface of the multiple optical elements provides an angle of incidence to a marginal ray that is above a minimum threshold angle. This threshold angle minimizes pupil ghosts that may enter an interferometer. The objective lens also optimizes wavefront delivery and pupil imaging onto an optical surface under test.

  9. A specter of coexistence: Is centrifugal community organization haunted by the ghost of competition?

    Science.gov (United States)

    Wasserberg, Gideon; Kotler, B.P.; Morris, D.W.; Abramsky, Z.

    2006-01-01

    In a centrifugally organized community species prefer the same habitat (called "core") but differ in their secondary habitat preferences. The first model of centrifugal community organization (CCO) predicted that optimally foraging, symmetrically competing species would share use of the core habitat at all density combinations. But one might also assume that the competition in the core habitat is asymmetrical, that is, that one of the species (the dominant) has a behavioral advantage therein. In this study, we asked how should habitat use evolve in a centrifugally organized community if its species compete asymmetrically in the core habitat? To address this question we developed an "isoleg model". The model predicts that in a centrifugally organized community, asymmetric competition promotes the use of the core habitat exclusively by the dominant species at most points in the state space. The separation of the core habitat use by the species ("the ghost of competition past") may be either complete or partial ("partial ghost"), and behavior at the stable competitive equilibrium between the species could determine whether coexistence should occur at the "complete-" or the "partial ghost" regions. This version of CCO should be a common feature of competitive systems.

  10. Ghost image in enhanced self-heterodyne synthetic aperture imaging ladar

    Science.gov (United States)

    Zhang, Guo; Sun, Jianfeng; Zhou, Yu; Lu, Zhiyong; Li, Guangyuan; Xu, Mengmeng; Zhang, Bo; Lao, Chenzhe; He, Hongyu

    2018-03-01

    The enhanced self-heterodyne synthetic aperture imaging ladar (SAIL) self-heterodynes two polarization-orthogonal echo signals to eliminate the phase disturbance caused by atmospheric turbulence and mechanical trembling, uses heterodyne receiver instead of self-heterodyne receiver to improve signal-to-noise ratio. The principle and structure of the enhanced self-heterodyne SAIL are presented. The imaging process of enhanced self-heterodyne SAIL for distributed target is also analyzed. In enhanced self-heterodyne SAIL, the phases of two orthogonal-polarization beams are modulated by four cylindrical lenses in transmitter to improve resolutions in orthogonal direction and travel direction, which will generate ghost image. The generation process of ghost image in enhanced self-heterodyne SAIL is mathematically detailed, and a method of eliminating ghost image is also presented, which is significant for far-distance imaging. A number of experiments of enhanced self-heterodyne SAIL for distributed target are presented, these experimental results verify the theoretical analysis of enhanced self-heterodyne SAIL. The enhanced self-heterodyne SAIL has the capability to eliminate the influence from the atmospheric turbulence and mechanical trembling, has high advantage in detecting weak signals, and has promising application for far-distance ladar imaging.

  11. Error threshold ghosts in a simple hypercycle with error prone self-replication

    International Nuclear Information System (INIS)

    Sardanyes, Josep

    2008-01-01

    A delayed transition because of mutation processes is shown to happen in a simple hypercycle composed by two indistinguishable molecular species with error prone self-replication. The appearance of a ghost near the hypercycle error threshold causes a delay in the extinction and thus in the loss of information of the mutually catalytic replicators, in a kind of information memory. The extinction time, τ, scales near bifurcation threshold according to the universal square-root scaling law i.e. τ ∼ (Q hc - Q) -1/2 , typical of dynamical systems close to a saddle-node bifurcation. Here, Q hc represents the bifurcation point named hypercycle error threshold, involved in the change among the asymptotic stability phase and the so-called Random Replication State (RRS) of the hypercycle; and the parameter Q is the replication quality factor. The ghost involves a longer transient towards extinction once the saddle-node bifurcation has occurred, being extremely long near the bifurcation threshold. The role of this dynamical effect is expected to be relevant in fluctuating environments. Such a phenomenon should also be found in larger hypercycles when considering the hypercycle species in competition with their error tail. The implications of the ghost in the survival and evolution of error prone self-replicating molecules with hypercyclic organization are discussed

  12. Hunting for CDF multi-muon ''ghost'' events at collider and fixed-target experiments

    International Nuclear Information System (INIS)

    Bornhauser, Nicki; Drees, Manuel

    2011-01-01

    In 2008 the CDF collaboration discovered a large excess of events containing two or more muons, at least one of which seemed to have been produced outside the beam pipe. We investigate whether similar ''ghost'' events could (and should) have been seen in already completed experiments. The CDF di-muon data can be reproduced by a simple model where a relatively light X particle undergoes 4-body decay. This model predicts a large number of ghost events in Fermilab fixed-target experiments E772, E789 and E866, applying the cuts optimized for analyses of Drell-Yan events. A correct description of events with more than two muons requires a more complicated model, where two X particles are produced from a very broad resonance Y. This model can be tested in fixed-target experiments only if the cut on the angles, or rapidities, of the muons can be relaxed. Either way, the UA1 experiment at the CERN p anti p collider should have observed O(100) ghost events. (orig.)

  13. [3H]Ouabain binding and Na+, K+-ATPase in resealed human red cell ghosts

    International Nuclear Information System (INIS)

    Shoemaker, D.G.; Lauf, P.K.

    1983-01-01

    The interaction of the cardiac glycoside [ 3 H]ouabain with the Na+, K+ pump of resealed human erythrocyte ghosts was investigated. Binding of [ 3 H]ouabain to high intracellular Na+ ghosts was studied in high extracellular Na+ media, a condition determined to produce maximal ouabain binding rates. Simultaneous examination of both the number of ouabain molecules bound per ghost and the corresponding inhibition of the Na+, K+-ATPase revealed that one molecule of [ 3 H]ouabain inhibited one Na+, K+-ATPase complex. Intracellular magnesium or magnesium plus inorganic phosphate produced the lowest ouabain binding rate. Support of ouabain binding by adenosine diphosphate (ADP) was negligible, provided synthesis of adenosine triphosphate (ATP) through the residual adenylate kinase activity was prevented by the adenylate kinase inhibitor Ap5A. Uridine 5'-triphosphate (UTP) alone did not support ouabain binding after inhibition of the endogenous nucleoside diphosphokinase by trypan blue and depletion of residual ATP by the incorporation of hexokinase and glucose. ATP acting solely at the high-affinity binding site of the Na+, K+ pump (Km approximately 1 microM) promoted maximal [ 3 H]ouabain binding rates. Failure of 5'-adenylyl-beta-gamma-imidophosphate (AMP-PNP) to stimulate significantly the rate of ouabain binding suggests that phosphorylation of the pump was required to expose the ouabain receptor

  14. Gravity and magnetic data across the Ghost Dance Fault in WT-2 Wash, Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Oliver, H.W.; Sikora, R.F.

    1994-01-01

    Detailed gravity and ground magnetic data were obtained in September 1993 along a 4,650 ft-long profile across the Ghost Dance Fault system in WT-2 Wash. Gravity stations were established every 150 feet along the profile. Total-field magnetic measurements made initially every 50 ft along the profile, then remade every 20 ft through the fault zone. These new data are part of a geologic and geophysical study of the Ghost Dance Fault (GDF) which includes detailed geologic mapping, seismic reflection, and some drilling including geologic and geophysical logging. The Ghost Dance Fault is the only through-going fault that has been identified within the potential repository for high-level radioactive waste at Yucca Mountain, Nevada. Preliminary gravity results show a distinct decrease of 0.1 to 0.2 mGal over a 600-ft-wide zone to the east of and including the mapped fault. The gravity decrease probably marks a zone of brecciation. Another fault-offset located about 2,000 ft to the east of the GDF was detected by seismic reflection data and is also marked by a distinct gravity low. The ground magnetic data show a 200-ft-wide magnetic low of about 400 nT centered about 100 ft east of the Ghost Dance Fault. The magnetic low probably marks a zone of brecciation within the normally polarized Topopah Spring Tuff, the top of which is about 170 ft below the surface, and which is known from drilling to extend to a depth of about 1,700 ft. Three-component magnetometer logging in drill hole WT-2 located about 2,700 ft east of the Ghost Dance Fault shows that the Topopah Spring Tuff is strongly polarized magnetically in this area, so that fault brecciation of a vertical zone within the Tuff could provide an average negative magnetic contrast of the 4 Am -1 needed to produce the 400 nT low observed at the surface

  15. Energy based model for temperature dependent behavior of ferromagnetic materials

    International Nuclear Information System (INIS)

    Sah, Sanjay; Atulasimha, Jayasimha

    2017-01-01

    An energy based model for temperature dependent anhysteretic magnetization curves of ferromagnetic materials is proposed and benchmarked against experimental data. This is based on the calculation of macroscopic magnetic properties by performing an energy weighted average over all possible orientations of the magnetization vector. Most prior approaches that employ this method are unable to independently account for the effect of both inhomogeneity and temperature in performing the averaging necessary to model experimental data. Here we propose a way to account for both effects simultaneously and benchmark the model against experimental data from ~5 K to ~300 K for two different materials in both annealed (fewer inhomogeneities) and deformed (more inhomogeneities) samples. This demonstrates that this framework is well suited to simulate temperature dependent experimental magnetic behavior. - Highlights: • Energy based model for temperature dependent ferromagnetic behavior. • Simultaneously accounts for effect of temperature and inhomogeneities. • Benchmarked against experimental data from 5 K to 300 K.

  16. Living in the “Ghost City”: Media Discourses and the Negotiation of Home in Ordos, Inner Mongolia, China

    Directory of Open Access Journals (Sweden)

    Duo Yin

    2017-11-01

    Full Text Available Ordos is notoriously represented in media discourses as one of China’s principal “ghost cities”, with skyscrapers, apartment estates and grandiose squares largely unoccupied. The “ghost city” emerges from massive (overinvestment in the urban built environment. Aware that economic and financial sustainability are in question, we nonetheless choose to investigate this issue from the perspective of social sustainability, utilizing a theoretical framework informed by geographies of home. Relatively little analysis has thus far been applied to local residents’ everyday practice and agency in making place and home in allegedly “unhomely” ghost cities. This article first examines media discourses and representations of the “ghostly” aspect of the new town in Ordos. It then investigates the ways in which local residents practice and perform their place identity and sense of home in an alleged “ghost city”. Our empirical research in Kangbashi New Town demonstrates that the discourse of ghost cities is valid in so far as we take into account the local residents’ engagement in a process of home-making from below. This sense of place is created by connecting new and old homes, and constructing an emotionally delineated place identity. We argue that the issue of social sustainability in Ordos is multifaceted, and more nuanced than it has hitherto been represented in media reports.

  17. Subatomic forces

    International Nuclear Information System (INIS)

    Sutton, C.

    1989-01-01

    Inside the atom, particles interact through two forces which are never felt in the everyday world. But they may hold the key to the Universe. These ideas on subatomic forces are discussed with respect to the strong force, the electromagnetic force and the electroweak force. (author)

  18. Formation of ghost images due to meta objects on the surface of the patient's face: A pictorial essay

    International Nuclear Information System (INIS)

    Ramons, BarbaraCouto; Da Silva Izar, Bruna Raquel; Pereira, Jessica Lourdes Costa; Souza Priscilla Serna; Valerio, Cludia Scigliano; Manzi, Flavio Ricardo; Tuji, Fabricio Mesquita

    2016-01-01

    Panoramic radiographs are a relatively simple technique that is commonly used in all dental specialties. In panoramic radiographs, in addition to the formation of real images of metal objects, ghost images may also form, and these ghost images can hinder an accurate diagnosis and interfere with the accuracy of radiology reports. Dentists must understand the formation of these images in order to avoid making incorrect radiographic diagnoses. Therefore, the present study sought to present a study of the formation of panoramic radiograph ghost images caused by metal objects in the head and neck region of a dry skull, as well as to report a clinical case n order to warn dentists about ghost images and to raise awareness thereof. An understanding of the principles of the formation of ghost images in panoramic radiographs helps prevent incorrect diagnoses

  19. Formation of ghost images due to meta objects on the surface of the patient's face: A pictorial essay

    Energy Technology Data Exchange (ETDEWEB)

    Ramons, BarbaraCouto; Da Silva Izar, Bruna Raquel; Pereira, Jessica Lourdes Costa; Souza Priscilla Serna; Valerio, Cludia Scigliano; Manzi, Flavio Ricardo [Dept. of Oral Radiology, School of Dentistry, Pontifical Catholic University of Minas Gerais, Belo Horizonte (Brazil); Tuji, Fabricio Mesquita [Federal University of Pará, Belém do Pará (Brazil)

    2016-03-15

    Panoramic radiographs are a relatively simple technique that is commonly used in all dental specialties. In panoramic radiographs, in addition to the formation of real images of metal objects, ghost images may also form, and these ghost images can hinder an accurate diagnosis and interfere with the accuracy of radiology reports. Dentists must understand the formation of these images in order to avoid making incorrect radiographic diagnoses. Therefore, the present study sought to present a study of the formation of panoramic radiograph ghost images caused by metal objects in the head and neck region of a dry skull, as well as to report a clinical case n order to warn dentists about ghost images and to raise awareness thereof. An understanding of the principles of the formation of ghost images in panoramic radiographs helps prevent incorrect diagnoses.

  20. Comparative study of receiver-side ghost wavefield attenuation on different marine acquisition configurations

    Science.gov (United States)

    Zhang, Hao; Liu, Qiancheng; Li, Hongyuan; Zhang, Yi

    2018-04-01

    In marine seismic exploration, the ghost energies (down-going waves), which arise from the reflection at the surface, are often treated as unwanted signals for data processing. The ghost wave fields interfere with the desired primary signals, leads to frequency notches and attenuation of low frequencies, which in turn downgrade the resolution of the recorded seismic data. There are two main categories of methods to solve the ghost or the so-called notch problem: the non-conventional acquisition configuration-based technique and a deghosting algorithm-based solution. The variable-depth streamer (VDS) acquisition solution is one of the most representative methods in the first category, which has become a popular solution for marine seismic acquisition to obtain broad data bandwidth. However, this approach is not as economic as the conventional constant depth streamer (CDS) acquisition, due to the precise control of the towing streamer. In addition, there are large quantities of conventionally-towed legacy data stored in the data library. Applying receiver deghosting to the CDS data thus becomes a more economical method. In theory, both types of data after deghosting should have the same bandwidth and S/N ratio, but in reality they are different. In this paper, we conduct a comparative study and evaluation to apply receiver deghosting to a set of real 2D marine data including both types of acquisition (CDS and VDS) corresponding to the same geology. The deghosting algorithm we employed is a self-sustained, inversion-based approach operated in the τ-p domain. This evaluation can help us to understand two questions: whether the VDS acquisition has more broadband characteristics compared to conventional CDS acquisition after deghosting, and whether we can achieve the identical or similar data quality (e.g., S/N ratio) through the proper deghosting algorithm for both types of data. The comparative results are illustrated and discussed.

  1. A robust mass spectrometry method for rapid profiling of erythrocyte ghost membrane proteomes.

    Science.gov (United States)

    Fye, Haddy K S; Mrosso, Paul; Bruce, Lesley; Thézénas, Marie-Laëtitia; Davis, Simon; Fischer, Roman; Rwegasira, Gration L; Makani, Julie; Kessler, Benedikt M

    2018-01-01

    Red blood cell (RBC) physiology is directly linked to many human disorders associated with low tissue oxygen levels or anemia including chronic obstructive pulmonary disease, congenital heart disease, sleep apnea and sickle cell anemia. Parasites such as Plasmodium spp. and phylum Apicomplexa directly target RBCs, and surface molecules within the RBC membrane are critical for pathogen interactions. Proteomics of RBC membrane 'ghost' fractions has therefore been of considerable interest, but protocols described to date are either suboptimal or too extensive to be applicable to a larger set of clinical cohorts. Here, we describe an optimised erythrocyte isolation protocol from blood, tested for various storage conditions and explored using different fractionation conditions for isolating ghost RBC membranes. Liquid chromatography mass spectrometry (LC-MS) analysis on a Q-Exactive Orbitrap instrument was used to profile proteins isolated from the comparative conditions. Data analysis was run on the MASCOT and MaxQuant platforms to assess their scope and diversity. The results obtained demonstrate a robust method for membrane enrichment enabling consistent MS based characterisation of > 900 RBC membrane proteins in single LC-MS/MS analyses. Non-detergent based membrane solubilisation methods using the tissue and supernatant fractions of isolated ghost membranes are shown to offer effective haemoglobin removal as well as diverse recovery including erythrocyte membrane proteins of high and low abundance. The methods described in this manuscript propose a medium to high throughput framework for membrane proteome profiling by LC-MS of potential applicability to larger clinical cohorts in a variety of disease contexts.

  2. Study on the algorithm of computational ghost imaging based on discrete fourier transform measurement matrix

    Science.gov (United States)

    Zhang, Leihong; Liang, Dong; Li, Bei; Kang, Yi; Pan, Zilan; Zhang, Dawei; Gao, Xiumin; Ma, Xiuhua

    2016-07-01

    On the basis of analyzing the cosine light field with determined analytic expression and the pseudo-inverse method, the object is illuminated by a presetting light field with a determined discrete Fourier transform measurement matrix, and the object image is reconstructed by the pseudo-inverse method. The analytic expression of the algorithm of computational ghost imaging based on discrete Fourier transform measurement matrix is deduced theoretically, and compared with the algorithm of compressive computational ghost imaging based on random measurement matrix. The reconstruction process and the reconstruction error are analyzed. On this basis, the simulation is done to verify the theoretical analysis. When the sampling measurement number is similar to the number of object pixel, the rank of discrete Fourier transform matrix is the same as the one of the random measurement matrix, the PSNR of the reconstruction image of FGI algorithm and PGI algorithm are similar, the reconstruction error of the traditional CGI algorithm is lower than that of reconstruction image based on FGI algorithm and PGI algorithm. As the decreasing of the number of sampling measurement, the PSNR of reconstruction image based on FGI algorithm decreases slowly, and the PSNR of reconstruction image based on PGI algorithm and CGI algorithm decreases sharply. The reconstruction time of FGI algorithm is lower than that of other algorithms and is not affected by the number of sampling measurement. The FGI algorithm can effectively filter out the random white noise through a low-pass filter and realize the reconstruction denoising which has a higher denoising capability than that of the CGI algorithm. The FGI algorithm can improve the reconstruction accuracy and the reconstruction speed of computational ghost imaging.

  3. Prevalence of articles with honorary and ghost authors in three pharmacy journals.

    Science.gov (United States)

    Dotson, Bryan; Slaughter, Richard L

    2011-09-15

    The prevalence of honorary and ghost authors in articles published in 2009 in three peer-reviewed pharmacy journals was studied. A 20-question survey was e-mailed to corresponding authors of articles with two or more authors published in 2009 in the American Journal of Health-System Pharmacy, Annals of Pharmacotherapy, and Pharmacotherapy. The survey solicited the following information: demographic characteristics of the corresponding author, information about the published article, information to determine whether any of the authors did not meet the International Committee of Medical Journal Editors criteria for authorship, and information to determine if an individual contributed substantially to the research or writing of the article but was not listed as an author. Of the 491 corresponding authors to whom the survey was sent, 457 had a working e-mail address; 114 surveys were completed (24.9% response rate). Usable responses were provided by 112 authors. The prevalence of articles with honorary and ghost authors was 14.3% and 0.9%, respectively. Honorary authorship was more common in original research than review articles. Articles with honorary authors had longer bylines than articles without honorary authors (mean number of authors, 4.9 versus 3.7; p = 0.002). The proportion of articles with an honorary author was 1.9% for articles with fewer than 4 authors, 25% for articles with 4 or 5 authors, and 29.4% for articles with more than 5 authors (p = 0.001). A survey sent to the corresponding authors of articles published in 2009 in three peer-reviewed pharmacy journals revealed that a substantial percentage of articles demonstrated evidence of honorary or ghost authorship.

  4. Energy-Based Metrics for Arthroscopic Skills Assessment.

    Science.gov (United States)

    Poursartip, Behnaz; LeBel, Marie-Eve; McCracken, Laura C; Escoto, Abelardo; Patel, Rajni V; Naish, Michael D; Trejos, Ana Luisa

    2017-08-05

    Minimally invasive skills assessment methods are essential in developing efficient surgical simulators and implementing consistent skills evaluation. Although numerous methods have been investigated in the literature, there is still a need to further improve the accuracy of surgical skills assessment. Energy expenditure can be an indication of motor skills proficiency. The goals of this study are to develop objective metrics based on energy expenditure, normalize these metrics, and investigate classifying trainees using these metrics. To this end, different forms of energy consisting of mechanical energy and work were considered and their values were divided by the related value of an ideal performance to develop normalized metrics. These metrics were used as inputs for various machine learning algorithms including support vector machines (SVM) and neural networks (NNs) for classification. The accuracy of the combination of the normalized energy-based metrics with these classifiers was evaluated through a leave-one-subject-out cross-validation. The proposed method was validated using 26 subjects at two experience levels (novices and experts) in three arthroscopic tasks. The results showed that there are statistically significant differences between novices and experts for almost all of the normalized energy-based metrics. The accuracy of classification using SVM and NN methods was between 70% and 95% for the various tasks. The results show that the normalized energy-based metrics and their combination with SVM and NN classifiers are capable of providing accurate classification of trainees. The assessment method proposed in this study can enhance surgical training by providing appropriate feedback to trainees about their level of expertise and can be used in the evaluation of proficiency.

  5. Energy-Based Facial Rejuvenation: Advances in Diagnosis and Treatment.

    Science.gov (United States)

    Britt, Christopher J; Marcus, Benjamin

    2017-01-01

    The market for nonsurgical, energy-based facial rejuvenation techniques has increased exponentially since lasers were first used for skin rejuvenation in 1983. Advances in this area have led to a wide range of products that require the modern facial plastic surgeon to have a large repertoire of knowledge. To serve as a guide for current trends in the development of technology, applications, and outcomes of laser and laser-related technology over the past 5 years. We performed a review of PubMed from January 1, 2011, to March 1, 2016, and focused on randomized clinical trials, meta-analyses, systematic reviews, and clinical practice guidelines including case control, case studies and case reports when necessary, and included 14 articles we deemed landmark articles before 2011. Three broad categories of technology are leading non-energy-based rejuvenation technology: lasers, light therapy, and non-laser-based thermal tightening devices. Laser light therapy has continued to diversify with the use of ablative and nonablative resurfacing technologies, fractionated lasers, and their combined use. Light therapy has developed for use in combination with other technologies or stand alone. Finally, thermally based nonlaser skin-tightening devices, such as radiofrequency (RF) and intense focused ultrasonography (IFUS), are evolving technologies that have changed rapidly over the past 5 years. Improvements in safety and efficacy for energy-based treatment have expanded the patient base considering these therapies viable options. With a wide variety of options, the modern facial plastic surgeon can have a frank discussion with the patient regarding nonsurgical techniques that were never before available. Many of these patients can now derive benefit from treatments requiring significantly less downtime than before while the clinician can augment the treatment to maximize benefit to fit the patient's time schedule.

  6. Dentinoameloblastoma with ghost cells: A rare case report with emphasis on its biological behavior

    Directory of Open Access Journals (Sweden)

    Kiran Kumar

    2013-01-01

    Full Text Available Ameloblastomas are regarded as a homogeneous group of neoplasms with locally invasive character. They generally do not show induction of dental hard tissue formation except in few cases. Biological behavior and histogenesis of these tumors is still unexplored as there is lack of relevant studies and long follow-up of these patients. So, we aimed to report this rare case of dentinoameloblastoma with unique presence of ghost cells in middle-aged female involving maxilla with emphasis on its biological behavior. We conclude that although histogenesis of this tumor is not clear but biological potential is similar to conventional ameloblastoma requiring wider excision.

  7. Ghost Dancing the Grand Canyon. Southern Paiute Rock Art, Ceremony, and Cultural Landscapes.

    Science.gov (United States)

    Stoffle; Loendorf; Austin; Halmo; Bulletts

    2000-02-01

    Combining rock art studies with ethnohistory, contemporary ethnographic analysis, and the interpretations of people who share the cultural traditions being studied, this paper documents a rock art site in Kanab Creek Canyon that appears to have been the location of a Ghost Dance ceremony performed by Southern Paiute and perhaps Hualapai people in the late 1800s. Using the site as a point of departure, it focuses on the way in which synergistic associations among place, artifact, resources, events, and historic and contemporary Indian people contribute to the construction of a contextual cultural landscape.

  8. Gravity's ghost and big dog scientific discovery and social analysis in the twenty-first century

    CERN Document Server

    Collins, Harry

    2013-01-01

    Gravity's Ghost and Big Dog brings to life science's efforts to detect cosmic gravitational waves. These ripples in space-time are predicted by general relativity, and their discovery will not only demonstrate the truth of Einstein's theories but also transform astronomy. Although no gravitational wave has ever been directly detected, the previous five years have been an especially exciting period in the field. Here sociologist Harry Collins offers readers an unprecedented view of gravitational wave research and explains what it means for an analyst to do work of this kind.

  9. Irish nationalism and the uncanny: a reading of “The ghost of Roger Casement”

    OpenAIRE

    Bolfarine, Mariana; Universidade de São Paulo

    2015-01-01

    Of the several fictional works about the Irish revolutionary Roger David Casement, none has reached the notoriety of William Butler Yeats’s poem “The ghost of Roger Casement” (1936). Roger Casement is known for acting as British Consul in Africa and in Brazil, having reported atrocities committed against the natives in these regions by imperial rubber companies. The aftermath of having witnessed the effects of such atrocities eventually turned Casement against the British Empire for which he ...

  10. Energy Based Clutter Filtering for Vector Flow Imaging

    DEFF Research Database (Denmark)

    Villagómez Hoyos, Carlos Armando; Jensen, Jonas; Ewertsen, Caroline

    2017-01-01

    for obtaining vector flow measurements, since the spectra overlaps at high beam-to-flow angles. In this work a distinct approach is proposed, where the energy of the velocity spectrum is used to differentiate among the two signals. The energy based method is applied by limiting the amplitude of the velocity...... spectrum function to a predetermined threshold. The effect of the clutter filtering is evaluated on a plane wave (PW) scan sequence in combination with transverse oscillation (TO) and directional beamforming (DB) for velocity estimation. The performance of the filter is assessed by comparison...

  11. A renewable energy based hydrogen demonstration park in Turkey. HYDEPARK

    Energy Technology Data Exchange (ETDEWEB)

    Ilhan, Niluefer; Ersoez, Atilla [TUEBITAK Marmara Research Center Energy Institute, Gebze Kocaeli (Turkey); Cubukcu, Mete [Ege Univ., Bornova, Izmir (Turkey). Solar Energy Inst.

    2010-07-01

    The main goal of this national project is to research hydrogen technologies and renewable energy applications. Solar and wind energy are utilized to obtain hydrogen via electrolysis, which can either be used in the fuel cell or stored in cylinders for further use. The management of all project work packages was carried by TUeBITAK Marmara Research Center (MRC) Energy Institute (EI) with the support of the collaborators. The aim of this paper is to present the units of the renewable energy based hydrogen demonstration park, which is in the demonstration phase now and share the experimental results. (orig.)

  12. Multistage Force Amplification of Piezoelectric Stacks

    Science.gov (United States)

    Xu, Tian-Bing (Inventor); Siochi, Emilie J. (Inventor); Zuo, Lei (Inventor); Jiang, Xiaoning (Inventor); Kang, Jin Ho (Inventor)

    2015-01-01

    Embodiments of the disclosure include an apparatus and methods for using a piezoelectric device, that includes an outer flextensional casing, a first cell and a last cell serially coupled to each other and coupled to the outer flextensional casing such that each cell having a flextensional cell structure and each cell receives an input force and provides an output force that is amplified based on the input force. The apparatus further includes a piezoelectric stack coupled to each cell such that the piezoelectric stack of each cell provides piezoelectric energy based on the output force for each cell. Further, the last cell receives an input force that is the output force from the first cell and the last cell provides an output apparatus force In addition, the piezoelectric energy harvested is based on the output apparatus force. Moreover, the apparatus provides displacement based on the output apparatus force.

  13. Forming positive-negative images using conditioned partial measurements from reference arm in ghost imaging.

    Science.gov (United States)

    Wen, Jianming

    2012-09-01

    A recent thermal ghost imaging experiment implemented in Wu's group [Chin. Phys. Lett. 279, 074216 (2012)] showed that both positive and negative images can be constructed by applying a novel algorithm. This algorithm allows us to form the images with the use of partial measurements from the reference arm (even which never passes through the object), conditioned on the object arm. In this paper, we present a simple theory that explains the experimental observation and provides an in-depth understanding of conventional ghost imaging. In particular, we theoretically show that the visibility of formed images through such an algorithm is not bounded by the standard value 1/3. In fact, it can ideally grow up to unity (with reduced imaging quality). Thus, the algorithm described here not only offers an alternative way to decode spatial correlation of thermal light, but also mimics a "bandpass filter" to remove the constant background such that the visibility or imaging contrast is improved. We further show that conditioned on one still object present in the test arm, it is possible to construct the object's image by sampling the available reference data.

  14. Increased phorbol 12,13-dibutyrate (PDBu) receptor function associated with sickle red cell membrane ghosts

    International Nuclear Information System (INIS)

    Ramachandran, M.; Nair, C.N.; Abraham, E.C.

    1987-01-01

    The biological receptor for tumor-promoting phorbol esters has been identified as the Ca 2+ /phospholipid dependent enzyme, protein kinase C. In the red cell, this enzyme is mainly cytosolic but becomes translocated to the membrane if the cellular Ca 2+ is allowed to rise. Since cellular Ca 2+ in sickle red cells is high, it was reasoned that this enzyme may become more membrane-bound. In fact, the authors noticed a four-fold increase in the binding of 3 H-PDBu by membrane ghosts isolated from sickle red cells compared to normal red cells (pmoles PDBu bound/mg protein; normal = 0.3 vs sickle cell = 1.4). Attempts to assay the enzyme directly as phospholipid-activated 32 P incorporation into the acid-precipitable membrane proteins also indicated a two-fold increase in the radiolabelling of sickle cell membrane ghosts. Autophosphorylation of membrane proteins and analysis of the phosphorylation profile by SDS-PAGE and autoradiography revealed phosphorylation predominantly of bands 3, 4.1 and 4.9 which are known protein kinase C substrates for the red cell enzyme. The increased membrane-associated protein kinase C in sickle red cells may have a bearing on the altered membrane properties reported in this condition

  15. At the Table with Hungry Ghosts: Intimate Borderwork in Mexico City

    Directory of Open Access Journals (Sweden)

    Jean Duruz

    2011-09-01

    Full Text Available This article focuses on the project of sustaining cultural diversity within global cities’ intimate spaces. Specifically, it sketches the culinary histories of an Anglo-Australian woman (who, in 1968, settled permanently in Mexico and her male partner (who grew up in Mexico; his mother Mexican, his father Cantonese. Drawing on the tools of ‘borderwork’ (Hodge and O’Carroll, the argument positions culturally diverse landscapes of ‘Sydney’, ‘China’ and ‘Mexico City’ as distinct yet overlapping geographies. Meanwhile, analysis of curious moments in the couple’s intersecting histories contributes much fluidity to this cartography. In the process, a company of hungry ghosts appears at the dinner table – ghosts of diversity, diaspora and cosmopolitanism; nostalgia and memory; gender and ethnicity; home and belonging. The article concludes that even when borderwork is conducted amiably behind closed doors, it relies on contradictions for cultural sustenance. At the same time, its tensions resonate with possibilities for creative practice.

  16. The ghost of pandemics past: revisiting two centuries of influenza in Sweden.

    Science.gov (United States)

    Holmberg, Martin

    2017-09-01

    Previous influenza pandemics are usually invoked in pandemic preparedness planning without a thorough analysis of the events surrounding them, what has been called the 'configuration' of epidemics. Historic pandemics are instead used to contrast them to the novelty of the coming imagined plague or as fear of a ghost-like repetition of the past. This view of pandemics is guided by a biomedical framework that is ahistorical and reductionist. The meaning of 'pandemic' influenza is in fact highly ambiguous in its partitioning of pandemic and seasonal influenza. The past 200 years of influenza epidemics in Sweden are examined with a special focus on key social structures-households, schools, transportations and the military. These are shown to have influenced the progression of influenza pandemics. Prevailing beliefs around influenza pandemics have also profoundly influenced intervention strategies. Measuring long-term trends in pandemic severity is problematic because pandemics are non-linear events where the conditions surrounding them constantly change. However, in a linearised view, the Spanish flu can be seen to represent a historical turning point and the H1N1 2009 pandemic not as an outlier, but following a 100-year trend of decreasing severity. Integrating seasonal and pandemic influenza, and adopting an ecosocial stance can deepen our understanding and bring the ghost-like pandemic past to life. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  17. Fed-Batch Production of Bacterial Ghosts Using Dielectric Spectroscopy for Dynamic Process Control

    Directory of Open Access Journals (Sweden)

    Andrea Meitz

    2016-03-01

    Full Text Available The Bacterial Ghost (BG platform technology evolved from a microbiological expression system incorporating the ϕX174 lysis gene E. E-lysis generates empty but structurally intact cell envelopes (BGs from Gram-negative bacteria which have been suggested as candidate vaccines, immunotherapeutic agents or drug delivery vehicles. E-lysis is a highly dynamic and complex biological process that puts exceptional demands towards process understanding and control. The development of a both economic and robust fed-batch production process for BGs required a toolset capable of dealing with rapidly changing concentrations of viable biomass during the E-lysis phase. This challenge was addressed using a transfer function combining dielectric spectroscopy and soft-sensor based biomass estimation for monitoring the rapid decline of viable biomass during the E-lysis phase. The transfer function was implemented to a feed-controller, which followed the permittivity signal closely and was capable of maintaining a constant specific substrate uptake rate during lysis phase. With the described toolset, we were able to increase the yield of BG production processes by a factor of 8–10 when compared to currently used batch procedures reaching lysis efficiencies >98%. This provides elevated potentials for commercial application of the Bacterial Ghost platform technology.

  18. High performance optical encryption based on computational ghost imaging with QR code and compressive sensing technique

    Science.gov (United States)

    Zhao, Shengmei; Wang, Le; Liang, Wenqiang; Cheng, Weiwen; Gong, Longyan

    2015-10-01

    In this paper, we propose a high performance optical encryption (OE) scheme based on computational ghost imaging (GI) with QR code and compressive sensing (CS) technique, named QR-CGI-OE scheme. N random phase screens, generated by Alice, is a secret key and be shared with its authorized user, Bob. The information is first encoded by Alice with QR code, and the QR-coded image is then encrypted with the aid of computational ghost imaging optical system. Here, measurement results from the GI optical system's bucket detector are the encrypted information and be transmitted to Bob. With the key, Bob decrypts the encrypted information to obtain the QR-coded image with GI and CS techniques, and further recovers the information by QR decoding. The experimental and numerical simulated results show that the authorized users can recover completely the original image, whereas the eavesdroppers can not acquire any information about the image even the eavesdropping ratio (ER) is up to 60% at the given measurement times. For the proposed scheme, the number of bits sent from Alice to Bob are reduced considerably and the robustness is enhanced significantly. Meantime, the measurement times in GI system is reduced and the quality of the reconstructed QR-coded image is improved.

  19. Study of key technology of ghost imaging via compressive sensing for a phase object based on phase-shifting digital holography

    International Nuclear Information System (INIS)

    Leihong, Zhang; Dong, Liang; Bei, Li; Zilan, Pan; Dawei, Zhang; Xiuhua, Ma

    2015-01-01

    In this article, the algorithm of compressing sensing is used to improve the imaging resolution and realize ghost imaging via compressive sensing for a phase object based on the theoretical analysis of the lensless Fourier imaging of the algorithm of ghost imaging based on phase-shifting digital holography. The algorithm of ghost imaging via compressive sensing based on phase-shifting digital holography uses the bucket detector to measure the total light intensity of the interference and the four-step phase-shifting method is used to obtain the total light intensity of differential interference light. The experimental platform is built based on the software simulation, and the experimental results show that the algorithm of ghost imaging via compressive sensing based on phase-shifting digital holography can obtain the high-resolution phase distribution figure of the phase object. With the same sampling times, the phase clarity of the phase distribution figure obtained by the algorithm of ghost imaging via compressive sensing based on phase-shifting digital holography is higher than that obtained by the algorithm of ghost imaging based on phase-shift digital holography. In this article, this study further extends the application range of ghost imaging and obtains the phase distribution of the phase object. (letter)

  20. The Contribution of the Holy Ghost Congregation to the Educational Development of Nigeria: Historical and Contemporary Reflections

    Science.gov (United States)

    Amadi, Anthony

    2016-01-01

    This article is a historical narrative about the contribution the Holy Ghost Congregation made in the educational development of Nigeria. It is narrative because it highlights the events and the work of the early Spiritan missionaries that brought education and its benefits to Nigerians. It is pedagogic because it describes the methods these Holy…

  1. Radiation-induced structural changes in membrane proteins of human erythrocytes and ghosts and the relation to cellular morphology

    Energy Technology Data Exchange (ETDEWEB)

    Schuurhuis, G.J.; Hommes, J.; Vos, J.; Molenaar, I.; Konings, A.W.T. (Rijksuniversiteit Groningen (Netherlands))

    1984-02-01

    Isolated human erythrocytes and ghosts were irradiated with X-rays under different experimental conditions and the effect examined with regard to the structure of membrane proteins and morphology of whole cells and ghosts. From sodium dodecyl sulphate/polyacrylamide gel electrophoresis it is concluded that spectrin (band 1 and 2) is the most radiosensitive of the membrane proteins examined. X-irradiation of cells and ghosts induced covalent cross-linking of a small fraction of membrane proteins. In the protein aggregates thus formed spectrin was found to be the major component. Molecular disulphide (-SS-) bridges seemed to account for part of the cross-links observed. Some nondisulphide cross-links were found, especially when ghosts were irradiated. Significant amounts of spectrin aggregates were formed during post-irradiation incubation at 37/sup 0/C but not at 4/sup 0/C. In the intact cell a transformation in shape from discocyte to echinocyte accompanied the process of post-irradiation spectrin aggregation. The characteristics of both processes, such as their reversibility with adenosine, point to a metabolic involvement. It is shown that there is no causal relationship between the two phenomena observed. Possible causes of the post-irradiation effects and the parallelism with similar processes in non-irradiated metabolically depleted cells are discussed.

  2. Radiation-induced structural changes in membrane proteins of human erythrocytes and ghosts and the relation to cellular morphology

    International Nuclear Information System (INIS)

    Schuurhuis, G.J.; Hommes, J.; Vos, J.; Molenaar, I.; Konings, A.W.T.

    1984-01-01

    Isolated human erythrocytes and ghosts were irradiated with X-rays under different experimental conditions and the effect examined with regard to the structure of membrane proteins and morphology of whole cells and ghosts. From sodium dodecyl sulphate/polyacrylamide gel electrophoresis it is concluded that spectrin (band 1 and 2) is the most radiosensitive of the membrane proteins examined. X-irradiation of cells and ghosts induced covalent cross-linking of a small fraction of membrane proteins. In the protein aggregates thus formed spectrin was found to be the major component. Molecular disulphide (-SS-) bridges seemed to account for part of the cross-links observed. Some nondisulphide cross-links were found, especially when ghosts were irradiated. Significant amounts of spectrin aggregates were formed during post-irradiation incubation at 37 0 C but not at 4 0 C. In the intact cell a transformation in shape from discocyte to echinocyte accompanied the process of post-irradiation spectrin aggregation. The characteristics of both processes, such as their reversibility with adenosine, point to a metabolic involvement. It is shown that there is no causal relationship between the two phenomena observed. Possible causes of the post-irradiation effects and the parallelism with similar processes in non-irradiated metabolically depleted cells are discussed. (author)

  3. PLOTGEOMX: a program for display of a neutron target assembly by means of a GHOST plotting system

    International Nuclear Information System (INIS)

    Clarke, J.H.

    1978-02-01

    The program PLOTGEOM has been modified to work on the A.E.R.E., Harwell IBM 370-167 computer using the GHOST graphics package. The control data routine has been altered to permit free format input and the program has been compiled and stored using the extended-H FORTRAN optimising compiler. (author)

  4. Ontogenetic changes in biochemical composition during larval and early postlarval development of Lepidophthalmus louisianensis, a ghost shrimp with abbreviated development

    Science.gov (United States)

    Larvae of the ghost shrimp, Lepidophthalmus louisianensis, were mass-reared under laboratory conditions (28|C; 20o/ooS) from hatching to the decapodid (D) stage. Iatroscan lipid class analysis revealed that polar lipids (Zoea I: 77.4|1.7%; Zoea II: 77.5|2.1%; Decapodid: 80.0|1.7%...

  5. Mrs. Shipley’s Ghost: The Right to Travel and Terrorist Watchlists (by Jeffrey Kahn, University of Michigan Press, 2013

    Directory of Open Access Journals (Sweden)

    Susan Ginsburg

    2014-04-01

    Full Text Available Since 9/11, migration-related security measures, including a growing reliance on watch-lists, have limited the right to travel. Jeffrey Kahn’s book, Mrs. Shipley’s Ghost: The Right to Travel and Terrorist Watchlists, examines the legal and policy questions raised by prohibitions on travel by US citizens. 

  6. Enhanced anti-proliferative efficacy of epothilone B loaded with Escherichia coli Nissle 1917 bacterial ghosts on the HeLa cells by mitochondrial pathway of apoptosis.

    Science.gov (United States)

    Zhu, Wenxing; Hao, Lujiang; Liu, Xinli; Orlando, Borrás-Hidalgo; Zhang, Yuyu

    2018-03-20

    Epothilones constitute a new class of microtubule-stabilizing anti-cancer agents with promising preclinical and clinical activity. However, its systemic application still causes some toxic side effects. To reduce these undesired effects, advanced drug delivery systems based on cell targeting carriers are needed currently. In this study, the high quality bacterial ghosts of the probiotic Escherichia coli Nissle 1917 (EcN) were prepared in a large scale and retained fully intact surface structures for specific attachment to mammalian cells. The EcN ghosts could be efficiently loaded with the low hydrophilic drug Epothilone B (Epo B) and the maximal load efficiency was approximately 2.5% (w/w). Cytotoxicity assays revealed that Epo B-ghosts exhibited enhanced anti-proliferative properties on the HeLa cells. The Epo B associated with EcN ghosts was more cytotoxic at least 10 times than the free Epo B at the same concentrations. Apoptosis assays showed that both Epo B-ghosts and free Epo B induced time course-dependent apoptosis and necrosis in HeLa cells, respectively. While the former induced more apoptosis and necrosis than the latter. Furthermore, the cytochrome C release and the activation of caspase-3 were more remarkable after treatment with the Epo B-ghosts compared to the free Epo B, which implied that Epo B-ghosts might more effectively induce the apoptosis mediated by mitochondrial pathway in HeLa cells. Therefore, the higher anti-proliferative effects of the Epo B-ghosts on the HeLa cells were mediated by mitochondrial pathway of apoptosis. The EcN ghosts may provide a useful drug delivery carrier for drug candidates in cancer therapy.

  7. A Comparative Study on Evaluation Methods of Fluid Forces on Cartesian Grids

    Directory of Open Access Journals (Sweden)

    Taku Nonomura

    2017-01-01

    Full Text Available We investigate the accuracy and the computational efficiency of the numerical schemes for evaluating fluid forces in Cartesian grid systems. A comparison is made between two different types of schemes, namely, polygon-based methods and mesh-based methods, which differ in the discretization of the surface of the object. The present assessment is intended to investigate the effects of the Reynolds number, the object motion, and the complexity of the object surface. The results show that the mesh-based methods work as well as the polygon-based methods, even if the object surface is discretized in a staircase manner. In addition, the results also show that the accuracy of the mesh-based methods is strongly dependent on the evaluation of shear stresses, and thus they must be evaluated by using a reliable method, such as the ghost-cell or ghost-fluid method.

  8. Labor Force

    Science.gov (United States)

    Occupational Outlook Quarterly, 2012

    2012-01-01

    The labor force is the number of people ages 16 or older who are either working or looking for work. It does not include active-duty military personnel or the institutionalized population, such as prison inmates. Determining the size of the labor force is a way of determining how big the economy can get. The size of the labor force depends on two…

  9. Ghost Music

    DEFF Research Database (Denmark)

    2012-01-01

    Geolocative AR concert for Arts Festival of North Norway (Festspillene i Nord-Norge), Harstad, Norge. In cooperation with The Norwegian Academy of Music, Oslo.......Geolocative AR concert for Arts Festival of North Norway (Festspillene i Nord-Norge), Harstad, Norge. In cooperation with The Norwegian Academy of Music, Oslo....

  10. Pepper's Ghost

    Science.gov (United States)

    Greenslade, Thomas B., Jr.

    2011-01-01

    Without applications of physics such as counter-weighted sets and backdrops, inclined planes, stage lighting instruments, and other mechanisms for "deus ex machina," dramatic productions would revert to the words only--fine for Shakespeare and Becket, but not good for audiences who are accustomed to experiencing plays with the eye as well as the…

  11. Optical identity authentication technique based on compressive ghost imaging with QR code

    Science.gov (United States)

    Wenjie, Zhan; Leihong, Zhang; Xi, Zeng; Yi, Kang

    2018-04-01

    With the rapid development of computer technology, information security has attracted more and more attention. It is not only related to the information and property security of individuals and enterprises, but also to the security and social stability of a country. Identity authentication is the first line of defense in information security. In authentication systems, response time and security are the most important factors. An optical authentication technology based on compressive ghost imaging with QR codes is proposed in this paper. The scheme can be authenticated with a small number of samples. Therefore, the response time of the algorithm is short. At the same time, the algorithm can resist certain noise attacks, so it offers good security.

  12. Functional display of ice nucleation protein InaZ on the surface of bacterial ghosts.

    Science.gov (United States)

    Kassmannhuber, Johannes; Rauscher, Mascha; Schöner, Lea; Witte, Angela; Lubitz, Werner

    2017-09-03

    In a concept study the ability to induce heterogeneous ice formation by Bacterial Ghosts (BGs) from Escherichia coli carrying ice nucleation protein InaZ from Pseudomonas syringae in their outer membrane was investigated by a droplet-freezing assay of ultra-pure water. As determined by the median freezing temperature and cumulative ice nucleation spectra it could be demonstrated that both the living recombinant E. coli and their corresponding BGs functionally display InaZ on their surface. Under the production conditions chosen both samples belong to type II ice-nucleation particles inducing ice formation at a temperature range of between -5.6 °C and -6.7 °C, respectively. One advantage for the application of such BGs over their living recombinant mother bacteria is that they are non-living native cell envelopes retaining the biophysical properties of ice nucleation and do no longer represent genetically modified organisms (GMOs).

  13. X-ray ‘ghost images’ could cut radiation doses

    Science.gov (United States)

    Chen, Sophia

    2018-03-01

    On its own, a single-pixel camera captures pictures that are pretty dull: squares that are completely black, completely white, or some shade of gray in between. All it does, after all, is detect brightness. Yet by connecting a single-pixel camera to a patterned light source, a team of physicists in China has made detailed x-ray images using a statistical technique called ghost imaging, first pioneered 20 years ago in infrared and visible light. Researchers in the field say future versions of this system could take clear x-ray photographs with cheap cameras—no need for lenses and multipixel detectors—and less cancer-causing radiation than conventional techniques.

  14. Gravitational field of static p -branes in linearized ghost-free gravity

    Science.gov (United States)

    Boos, Jens; Frolov, Valeri P.; Zelnikov, Andrei

    2018-04-01

    We study the gravitational field of static p -branes in D -dimensional Minkowski space in the framework of linearized ghost-free (GF) gravity. The concrete models of GF gravity we consider are parametrized by the nonlocal form factors exp (-□/μ2) and exp (□2/μ4) , where μ-1 is the scale of nonlocality. We show that the singular behavior of the gravitational field of p -branes in general relativity is cured by short-range modifications introduced by the nonlocalities, and we derive exact expressions of the regularized gravitational fields, whose geometry can be written as a warped metric. For large distances compared to the scale of nonlocality, μ r →∞ , our solutions approach those found in linearized general relativity.

  15. A benign property of the ghost mode in massive theory of gravitation

    Science.gov (United States)

    Chugreev, Yu. V.

    2018-01-01

    It was shown in the frameworks of massive gravitational theories having in linear approximation mass term {m^2}( {φ ^{α β }}{φ_{α β }} - 1/2{φ ^2}} ) in the lagrangian, that created some time ago spherically-symmetric static sources should possess inside their light cone not only Yukawa potential, but also nonstationary component. It leads to the long ( 1/ m) period of gravitational evaporation of such sources with the mass loss Ṁ m 2 M 2 The magnitude of the flux is c 4/ v 4 times ( c—speed of light, v—velocity of the source particles) bigger then negative gravitational radiation flux corresponding to the ghost scalar mode in the spectrum of such gravitational field, with stabilizing the source.

  16. The anomalous dimension of the gluon-ghost mass operator in Yang-Mills theory

    International Nuclear Information System (INIS)

    Dudal, D.; Verschelde, H.; Lemes, V.E.R.; Sarandy, M.S.; Sobreiro, R.; Sorella, S.P.; Picariello, M.; Gracey, J.A.

    2003-01-01

    The local composite gluon-ghost operator (((1)/(2))A aμ A μ a +αc-bar a c a ) is analysed in the framework of the algebraic renormalization in SU(N) Yang-Mills theories in the Landau, Curci-Ferrari and maximal abelian gauges. We show, to all orders of perturbation theory, that this operator is multiplicatively renormalizable. Furthermore, its anomalous dimension is not an independent parameter of the theory, being given by a general expression valid in all these gauges. We also verify the relations we obtain for the operator anomalous dimensions by explicit 3-loop calculations in the MS-bar scheme for the Curci-Ferrari gauge

  17. Modalities of representation and perception in Michael Ondaatje’s Anil’s Ghost

    Directory of Open Access Journals (Sweden)

    Sigrid Renaux

    2017-01-01

    Full Text Available http://dx.doi.org/10.5007/2175-8026.2017v70n1p113 This study analyses the way in which the interdependence of the representation and perception of reality is exemplified and questioned in Michael Ondaatje’s Anil’s Ghost (2000. As we enter this work of resistance literature by way of an omniscient narrator, we enter not just the geographical spaces and cultural history of Sri Lanka, but find ourselves taking part in the daily struggle of the people to survive, to identify and do justice to the many dead in this conflict between ethnic groups and the government. This fragmentation of the narrative structure – casting doubt on the conflicting relationships established between the characters’ present and the past, between western and eastern values in relation to the concept of truth, the search for lost identity and love – highlights still further the interchangeability of representation and perception of reality.

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

    Science.gov (United States)

    Yang, Dan

    2018-02-01

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

  19. Incorporating Quantitative Reasoning in Common Core Courses: Mathematics for The Ghost Map

    Directory of Open Access Journals (Sweden)

    John R. Jungck

    2012-01-01

    Full Text Available How can mathematics be integrated into multi-section interdisciplinary courses to enhance thematic understandings and shared common readings? As an example, four forms of quantitative reasoning are used to understand and critique one such common reading: Steven Berlin Johnson’s "The Ghost Map: The Story of London's Most Terrifying Epidemic - and How it Changed Science, Cities and the Modern World" (Riverhead Books, 2006. Geometry, statistics, modeling, and networks are featured in this essay as the means of depicting, understanding, elaborating, and critiquing the public health issues raised in Johnson’s book. Specific pedagogical examples and resources are included to illustrate applications and opportunities for generalization beyond this specific example. Quantitative reasoning provides a robust, yet often neglected, lens for doing literary and historical analyses in interdisciplinary education.

  20. Unusual square roots in the ghost-free theory of massive gravity

    Science.gov (United States)

    Golovnev, Alexey; Smirnov, Fedor

    2017-06-01

    A crucial building block of the ghost free massive gravity is the square root function of a matrix. This is a problematic entity from the viewpoint of existence and uniqueness properties. We accurately describe the freedom of choosing a square root of a (non-degenerate) matrix. It has discrete and (in special cases) continuous parts. When continuous freedom is present, the usual perturbation theory in terms of matrices can be critically ill defined for some choices of the square root. We consider the new formulation of massive and bimetric gravity which deals directly with eigenvalues (in disguise of elementary symmetric polynomials) instead of matrices. It allows for a meaningful discussion of perturbation theory in such cases, even though certain non-analytic features arise.

  1. A class of energy-based ensembles in Tsallis statistics

    International Nuclear Information System (INIS)

    Chandrashekar, R; Naina Mohammed, S S

    2011-01-01

    A comprehensive investigation is carried out on the class of energy-based ensembles. The eight ensembles are divided into two main classes. In the isothermal class of ensembles the individual members are at the same temperature. A unified framework is evolved to describe the four isothermal ensembles using the currently accepted third constraint formalism. The isothermal–isobaric, grand canonical and generalized ensembles are illustrated through a study of the classical nonrelativistic and extreme relativistic ideal gas models. An exact calculation is possible only in the case of the isothermal–isobaric ensemble. The study of the ideal gas models in the grand canonical and the generalized ensembles has been carried out using a perturbative procedure with the nonextensivity parameter (1 − q) as the expansion parameter. Though all the thermodynamic quantities have been computed up to a particular order in (1 − q) the procedure can be extended up to any arbitrary order in the expansion parameter. In the adiabatic class of ensembles the individual members of the ensemble have the same value of the heat function and a unified formulation to described all four ensembles is given. The nonrelativistic and the extreme relativistic ideal gases are studied in the isoenthalpic–isobaric ensemble, the adiabatic ensemble with number fluctuations and the adiabatic ensemble with number and particle fluctuations

  2. New Ghost-node method for linking different models with varied grid refinement

    International Nuclear Information System (INIS)

    Mehl, Steffen W.; Hill, Mary Catherine; James, Scott Carlton; Leake, Stanley A.; Zyvoloski, George A.; Dickinson, Jesse E.; Eddebbarh, Al A.

    2006-01-01

    A flexible, robust method for linking grids of locally refined models constructed with different numerical methods is needed to address a variety of hydrologic problems. This work outlines and tests a new ghost-node model-linking method for a refined 'child' model that is contained within a larger and coarser 'parent' model that is based on the iterative method of Mehl and Hill (2002, 2004). The method is applicable to steady-state solutions for ground-water flow. Tests are presented for a homogeneous two-dimensional system that has either matching grids (parent cells border an integer number of child cells; Figure 2a) or non-matching grids (parent cells border a non-integer number of child cells; Figure 2b). The coupled grids are simulated using the finite-difference and finite-element models MODFLOW and FEHM, respectively. The simulations require no alteration of the MODFLOW or FEHM models and are executed using a batch file on Windows operating systems. Results indicate that when the grids are matched spatially so that nodes and child cell boundaries are aligned, the new coupling technique has error nearly equal to that when coupling two MODFLOW models (Mehl and Hill, 2002). When the grids are non-matching, model accuracy is slightly increased over matching-grid cases. Overall, results indicate that the ghost-node technique is a viable means to accurately couple distinct models because the overall error is less than if only the regional model was used to simulate flow in the child model's domain

  3. Antioxidant effect of 4-nerolidylcatechol and α-tocopherol in erythrocyte ghost membranes and phospholipid bilayers

    Science.gov (United States)

    Fernandes, K.S.; Silva, A.H.M.; Mendanha, S.A.; Rezende, K.R.; Alonso, A.

    2013-01-01

    4-Nerolidylcatechol (4-NC) is found in Pothomorphe umbellata root extracts and is reported to have a topical protective effect against UVB radiation-induced skin damage, toxicity in melanoma cell lines, and antimalarial activity. We report a comparative study of the antioxidant activity of 4-NC and α-tocopherol against lipid peroxidation initiated by two free radical-generating systems: 2,2′-azobis(2-aminopropane) hydrochloride (AAPH) and FeSO4/H2O2, in red blood cell ghost membranes and in egg phosphatidylcholine (PC) vesicles. Lipid peroxidation was monitored by membrane fluidity changes assessed by electron paramagnetic resonance spectroscopy of a spin-labeled lipid and by the formation of thiobarbituric acid-reactive substances. When lipoperoxidation was initiated by the hydroxyl radical in erythrocyte ghost membranes, both 4-NC and α-tocopherol acted in a very efficient manner. However, lower activities were observed when lipoperoxidation was initiated by the peroxyl radical; and, in this case, the protective effect of α-tocopherol was lower than that of 4-NC. In egg PC vesicles, malondialdehyde formation indicated that 4-NC was effective against lipoperoxidation initiated by both AAPH and FeSO4/H2O2, whereas α-tocopherol was less efficient in protecting against lipoperoxidation by AAPH, and behaved as a pro-oxidant for FeSO4/H2O2. The DPPH (2,2-diphenyl-1-picrylhydrazyl) free-radical assay indicated that two free radicals were scavenged per 4-NC molecule, and one free radical was scavenged per α-tocopherol molecule. These data provide new insights into the antioxidant capacity of 4-NC, which may have therapeutic applications for formulations designed to protect the skin from sunlight irradiation. PMID:24068194

  4. New ghost-node method for linking different models with varied grid refinement

    Science.gov (United States)

    James, S.C.; Dickinson, J.E.; Mehl, S.W.; Hill, M.C.; Leake, S.A.; Zyvoloski, G.A.; Eddebbarh, A.-A.

    2006-01-01

    A flexible, robust method for linking grids of locally refined ground-water flow models constructed with different numerical methods is needed to address a variety of hydrologic problems. This work outlines and tests a new ghost-node model-linking method for a refined "child" model that is contained within a larger and coarser "parent" model that is based on the iterative method of Steffen W. Mehl and Mary C. Hill (2002, Advances in Water Res., 25, p. 497-511; 2004, Advances in Water Res., 27, p. 899-912). The method is applicable to steady-state solutions for ground-water flow. Tests are presented for a homogeneous two-dimensional system that has matching grids (parent cells border an integer number of child cells) or nonmatching grids. The coupled grids are simulated by using the finite-difference and finite-element models MODFLOW and FEHM, respectively. The simulations require no alteration of the MODFLOW or FEHM models and are executed using a batch file on Windows operating systems. Results indicate that when the grids are matched spatially so that nodes and child-cell boundaries are aligned, the new coupling technique has error nearly equal to that when coupling two MODFLOW models. When the grids are nonmatching, model accuracy is slightly increased compared to that for matching-grid cases. Overall, results indicate that the ghost-node technique is a viable means to couple distinct models because the overall head and flow errors relative to the analytical solution are less than if only the regional coarse-grid model was used to simulate flow in the child model's domain.

  5. Scalable Failure Masking for Stencil Computations using Ghost Region Expansion and Cell to Rank Remapping

    International Nuclear Information System (INIS)

    Gamell, Marc; Kolla, Hemanth; Mayo, Jackson; Heroux, Michael A.

    2017-01-01

    In order to achieve exascale systems, application resilience needs to be addressed. Some programming models, such as task-DAG (directed acyclic graphs) architectures, currently embed resilience features whereas traditional SPMD (single program, multiple data) and message-passing models do not. Since a large part of the community's code base follows the latter models, it is still required to take advantage of application characteristics to minimize the overheads of fault tolerance. To that end, this paper explores how recovering from hard process/node failures in a local manner is a natural approach for certain applications to obtain resilience at lower costs in faulty environments. In particular, this paper targets enabling online, semitransparent local recovery for stencil computations on current leadership-class systems as well as presents programming support and scalable runtime mechanisms. Also described and demonstrated in this paper is the effect of failure masking, which allows the effective reduction of impact on total time to solution due to multiple failures. Furthermore, we discuss, implement, and evaluate ghost region expansion and cell-to-rank remapping to increase the probability of failure masking. To conclude, this paper shows the integration of all aforementioned mechanisms with the S3D combustion simulation through an experimental demonstration (using the Titan system) of the ability to tolerate high failure rates (i.e., node failures every five seconds) with low overhead while sustaining performance at large scales. In addition, this demonstration also displays the failure masking probability increase resulting from the combination of both ghost region expansion and cell-to-rank remapping.

  6. Gluon and ghost propagator studies in lattice QCD at finite temperature

    International Nuclear Information System (INIS)

    Aouane, Rafik

    2013-01-01

    Gluon and ghost propagators in quantum chromodynamics (QCD) computed in the infrared momentum region play an important role to understand quark and gluon confinement. They are the subject of intensive research thanks to non-perturbative methods based on Dyson-Schwinger (DS) and functional renormalization group (FRG) equations. Moreover, their temperature behavior might also help to explore the chiral and deconfinement phase transition or crossover within QCD at non-zero temperature. Our prime tool is the lattice discretized QCD (LQCD) providing a unique ab-initio non-perturbative approach to deal with the computation of various observables of the hadronic world. We investigate the temperature dependence of Landau gauge gluon and ghost propagators in pure gluodynamics and in full QCD. Regarding the gluon propagator, we compute its longitudinal D L as well its transversal D T components. The aim is to provide a data set in terms of fitting formulae which can be used as input for DS (or FRG) equations. We deal with full (N f =2) LQCD with the twisted mass fermion discretization. We employ gauge field configurations provided by the tmfT collaboration for temperatures in the crossover region and for three fixed pion mass values in the range [300,500] MeV. Finally, within SU(3) pure gauge theory (at T=0) we compute the Landau gauge gluon propagator according to different gauge fixing criteria. Our goal is to understand the influence of gauge copies with minimal (non-trivial) eigenvalues of the Faddeev-Popov operator.

  7. Gluon and ghost propagator studies in lattice QCD at finite temperature

    Energy Technology Data Exchange (ETDEWEB)

    Aouane, Rafik

    2013-04-29

    Gluon and ghost propagators in quantum chromodynamics (QCD) computed in the infrared momentum region play an important role to understand quark and gluon confinement. They are the subject of intensive research thanks to non-perturbative methods based on Dyson-Schwinger (DS) and functional renormalization group (FRG) equations. Moreover, their temperature behavior might also help to explore the chiral and deconfinement phase transition or crossover within QCD at non-zero temperature. Our prime tool is the lattice discretized QCD (LQCD) providing a unique ab-initio non-perturbative approach to deal with the computation of various observables of the hadronic world. We investigate the temperature dependence of Landau gauge gluon and ghost propagators in pure gluodynamics and in full QCD. Regarding the gluon propagator, we compute its longitudinal D{sub L} as well its transversal D{sub T} components. The aim is to provide a data set in terms of fitting formulae which can be used as input for DS (or FRG) equations. We deal with full (N{sub f}=2) LQCD with the twisted mass fermion discretization. We employ gauge field configurations provided by the tmfT collaboration for temperatures in the crossover region and for three fixed pion mass values in the range [300,500] MeV. Finally, within SU(3) pure gauge theory (at T=0) we compute the Landau gauge gluon propagator according to different gauge fixing criteria. Our goal is to understand the influence of gauge copies with minimal (non-trivial) eigenvalues of the Faddeev-Popov operator.

  8. Antioxidant effect of 4-nerolidylcatechol and α-tocopherol in erythrocyte ghost membranes and phospholipid bilayers

    International Nuclear Information System (INIS)

    Fernandes, K.S.; Silva, A.H.M.; Mendanha, S.A.; Rezende, K.R.; Alonso, A.

    2013-01-01

    4-Nerolidylcatechol (4-NC) is found in Pothomorphe umbellata root extracts and is reported to have a topical protective effect against UVB radiation-induced skin damage, toxicity in melanoma cell lines, and antimalarial activity. We report a comparative study of the antioxidant activity of 4-NC and α-tocopherol against lipid peroxidation initiated by two free radical-generating systems: 2,2′-azobis(2-aminopropane) hydrochloride (AAPH) and FeSO 4 /H 2 O 2 , in red blood cell ghost membranes and in egg phosphatidylcholine (PC) vesicles. Lipid peroxidation was monitored by membrane fluidity changes assessed by electron paramagnetic resonance spectroscopy of a spin-labeled lipid and by the formation of thiobarbituric acid-reactive substances. When lipoperoxidation was initiated by the hydroxyl radical in erythrocyte ghost membranes, both 4-NC and α-tocopherol acted in a very efficient manner. However, lower activities were observed when lipoperoxidation was initiated by the peroxyl radical; and, in this case, the protective effect of α-tocopherol was lower than that of 4-NC. In egg PC vesicles, malondialdehyde formation indicated that 4-NC was effective against lipoperoxidation initiated by both AAPH and FeSO 4 /H 2 O 2 , whereas α-tocopherol was less efficient in protecting against lipoperoxidation by AAPH, and behaved as a pro-oxidant for FeSO 4 /H 2 O 2 . The DPPH (2,2-diphenyl-1-picrylhydrazyl) free-radical assay indicated that two free radicals were scavenged per 4-NC molecule, and one free radical was scavenged per α-tocopherol molecule. These data provide new insights into the antioxidant capacity of 4-NC, which may have therapeutic applications for formulations designed to protect the skin from sunlight irradiation

  9. Antioxidant effect of 4-nerolidylcatechol and α-tocopherol in erythrocyte ghost membranes and phospholipid bilayers

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, K. S.; Silva, A. H.M.; Mendanha, S. A. [Instituto de Física, Universidade Federal de Goiás, Goiânia, GO (Brazil); Rezende, K. R. [Laboratório de Biofarmácia e Farmacocinética de Substâncias Bioativas, Faculdade de Farmácia, Universidade Federal de Goiás, Goiânia, GO (Brazil); Alonso, A. [Instituto de Física, Universidade Federal de Goiás, Goiânia, GO (Brazil)

    2013-09-06

    4-Nerolidylcatechol (4-NC) is found in Pothomorphe umbellata root extracts and is reported to have a topical protective effect against UVB radiation-induced skin damage, toxicity in melanoma cell lines, and antimalarial activity. We report a comparative study of the antioxidant activity of 4-NC and α-tocopherol against lipid peroxidation initiated by two free radical-generating systems: 2,2′-azobis(2-aminopropane) hydrochloride (AAPH) and FeSO{sub 4}/H{sub 2}O{sub 2}, in red blood cell ghost membranes and in egg phosphatidylcholine (PC) vesicles. Lipid peroxidation was monitored by membrane fluidity changes assessed by electron paramagnetic resonance spectroscopy of a spin-labeled lipid and by the formation of thiobarbituric acid-reactive substances. When lipoperoxidation was initiated by the hydroxyl radical in erythrocyte ghost membranes, both 4-NC and α-tocopherol acted in a very efficient manner. However, lower activities were observed when lipoperoxidation was initiated by the peroxyl radical; and, in this case, the protective effect of α-tocopherol was lower than that of 4-NC. In egg PC vesicles, malondialdehyde formation indicated that 4-NC was effective against lipoperoxidation initiated by both AAPH and FeSO{sub 4}/H{sub 2}O{sub 2}, whereas α-tocopherol was less efficient in protecting against lipoperoxidation by AAPH, and behaved as a pro-oxidant for FeSO{sub 4}/H{sub 2}O{sub 2}. The DPPH (2,2-diphenyl-1-picrylhydrazyl) free-radical assay indicated that two free radicals were scavenged per 4-NC molecule, and one free radical was scavenged per α-tocopherol molecule. These data provide new insights into the antioxidant capacity of 4-NC, which may have therapeutic applications for formulations designed to protect the skin from sunlight irradiation.

  10. Ghosting effect in Siemens electronic portal imaging devices (EPIDs) for step and shoot IMRT dosimetry

    International Nuclear Information System (INIS)

    Deshpande, S.; Vial, P.; Goozee, G.; Holloway, L.

    2010-01-01

    Full text: To assess the ghosting effect of a Siemens EPID (Optivue 1000: while acquiring IMRT fluence with step and shoot delivery. Six sets of segmented fields with 1,2,3,5, J( and 20 monitor units (MU) per segment were designed. Each set consisted of ten segments of equal MU and field size (J 0 x 10 cm 2 ) Standard single fields (non-segmented) of the same total MU as the segmented fields were also created (10-200 MU). EPID images for these fields were acquired with multi-frame acquisition mode. The integrated EPID response was determined as the mean central 20 x 21 pixel readout multiplied by the number of frames. The same fields wen measured with an ionization chamber at a depth of dose maximum in, solid water phantom. The total signal measured from the segmented fields was compared to the corresponding non-segmented fields. The ratio of EPID response between segmented and non-segmented delivery indicates an under-response for segmented fields by 5, 4, 2.5 and 2% for 1,2,3, and 5 MU per segment exposures respectively compared to ionisation chamber response (se Fig. I). The ratio was within 2% for 5 MU per segment and above. Th error bar in Fig. I indicate the intra-segment response variation. The Siemens EPID exhibited significant ghosting effect and variation in response for small M U segments. EPID dosimetry ( IMRT fields with less than 5 MU per segment requires corrections t maintain dose calibration accuracy to within 2%. (author)

  11. The x-ray time of flight method for investigation of ghosting in amorphous selenium-based flat panel medical x-ray imagers

    International Nuclear Information System (INIS)

    Rau, A.W.; Bakueva, L.; Rowlands, J.A.

    2005-01-01

    Amorphous selenium (a-Se) based real-time flat-panel imagers (FPIs) are finding their way into the digital radiology department because they offer the practical advantages of digital x-ray imaging combined with an image quality that equals or outperforms that of conventional systems. The temporal imaging characteristics of FPIs can be affected by ghosting (i.e., radiation-induced changes of sensitivity) when the dose to the detector is high (e.g., portal imaging and mammography) or the images are acquired at a high frame rate (e.g., fluoroscopy). In this paper, the x-ray time-of-flight (TOF) method is introduced as a tool for the investigation of ghosting in a-Se photoconductor layers. The method consists of irradiating layers of a-Se with short x-ray pulses. From the current generated in the a-Se layer, ghosting is quantified and the ghosting parameters (charge carrier generation rate and carrier lifetimes and mobilities) are assessed. The x-ray TOF method is novel in that (1) x-ray sensitivity (S) and ghosting parameters can be measured simultaneously (2) the transport of both holes and electrons can be isolated, and (3) the method is applicable to the practical a-Se layer structure with blocking contacts used in FPIs. The x-ray TOF method was applied to an analysis of ghosting in a-Se photoconductor layers under portal imaging conditions, i.e., 1 mm thick a-Se layers, biased at 5 V/μm, were irradiated using a 6 MV LINAC x-ray beam to a total dose (ghosting dose) of 30 Gy. The initial sensitivity (S 0 ) of the a-Se layers was 63±2 nC cm -2 cGy -1 . It was found that S decreases to 30% of S 0 after a ghosting dose of 5 Gy and to 21% after 30 Gy at which point no further change in S occurs. At an x-ray intensity of 22 Gy/s (instantaneous dose rate during a LINAC x-ray pulse), the charge carrier generation rate was 1.25±0.1x10 22 ehp m -3 s -1 and, to a first approximation, independent of the ghosting dose. However, both hole and electron transport showed a

  12. Dispersion Forces

    CERN Document Server

    Buhmann, Stefan Yoshi

    2012-01-01

    In this book, a modern unified theory of dispersion forces on atoms and bodies is presented which covers a broad range of advanced aspects and scenarios. Macroscopic quantum electrodynamics is shown to provide a powerful framework for dispersion forces which allows for discussing general properties like their non-additivity and the relation between microscopic and macroscopic interactions. It is demonstrated how the general results can be used to obtain dispersion forces on atoms in the presence of bodies of various shapes and materials. Starting with a brief recapitulation of volume I, this volume II deals especially with bodies of irregular shapes, universal scaling laws, dynamical forces on excited atoms, enhanced forces in cavity quantum electrodynamics, non-equilibrium forces in thermal environments and quantum friction. The book gives both the specialist and those new to the field a thorough overview over recent results in the field. It provides a toolbox for studying dispersion forces in various contex...

  13. Like night and day: Reversals of thermal gradients across ghost crab burrows and their implications for thermal ecology

    Science.gov (United States)

    Watson, Gregory S.; Gregory, Emily A.; Johnstone, Charmaine; Berlino, Manuel; Green, David W.; Peterson, Nicola R.; Schoeman, David S.; Watson, Jolanta A.

    2018-04-01

    Ghost crabs, Ocypode cordimanus, inhabit relatively hostile environments subject to thermal fluctuations, including both diurnal and seasonal cycles. For many ectotherms, including ghost crabs, a major challenge is to remain cool during hot daytime temperatures. This can be achieved by adopting a fossorial lifestyle, taking advantage of thermal refuge afforded by burrows of sufficient depth. Another consideration, often overlooked, is the potential advantage associated with ready access to a thermal energy source (a "charging station") when surface temperatures are cooler. Being able to rapidly elevate body temperature during cool periods would enhance the crab's ability to maintain rate processes and carry out essential activities. We have measured ghost crab burrow temperature profiles at two times of the day with contrasting sun exposure (06:00 and 14:00), demonstrating how effective burrow depth (up to a maximum of 40 cm) provides thermal regulation below the surface of the sand (e.g., at dawn (06:00) and early afternoon (14:00) at a depth of 5 cm, temperatures (±SD) of 16.32 ± 0.96 °C and 25.04 ± 1.47 °C were recorded, respectively. Corresponding temperatures at a depth of 30 cm were 19.17 ± 0.59 °C and 19.78 ± 1.60 °C, respectively). This demonstrates that while temperature conditions at the surface vary dramatically from night to day, ghost crab burrows can maintain relatively constant temperatures at the burrow base throughout the diurnal cycle, at least during winter. As a consequence, the burrow heat signatures undergo a corresponding thermal gradient reversal between night and day, as revealed by infra-red photography. Complementing these field observations, we also determined heating and cooling times/constants for O. cordimanus in the laboratory (τ = 17.54 and 16.59 JK-1, respectively), and analysed chemical composition of their carapace (external (with β Chitin evident) and internal (predominance of α Chitin)), which is the primary thermal

  14. Multiple-image encryption via lifting wavelet transform and XOR operation based on compressive ghost imaging scheme

    Science.gov (United States)

    Li, Xianye; Meng, Xiangfeng; Yang, Xiulun; Wang, Yurong; Yin, Yongkai; Peng, Xiang; He, Wenqi; Dong, Guoyan; Chen, Hongyi

    2018-03-01

    A multiple-image encryption method via lifting wavelet transform (LWT) and XOR operation is proposed, which is based on a row scanning compressive ghost imaging scheme. In the encryption process, the scrambling operation is implemented for the sparse images transformed by LWT, then the XOR operation is performed on the scrambled images, and the resulting XOR images are compressed in the row scanning compressive ghost imaging, through which the ciphertext images can be detected by bucket detector arrays. During decryption, the participant who possesses his/her correct key-group, can successfully reconstruct the corresponding plaintext image by measurement key regeneration, compression algorithm reconstruction, XOR operation, sparse images recovery, and inverse LWT (iLWT). Theoretical analysis and numerical simulations validate the feasibility of the proposed method.

  15. Optical image transformation and encryption by phase-retrieval-based double random-phase encoding and compressive ghost imaging

    Science.gov (United States)

    Yuan, Sheng; Yang, Yangrui; Liu, Xuemei; Zhou, Xin; Wei, Zhenzhuo

    2018-01-01

    An optical image transformation and encryption scheme is proposed based on double random-phase encoding (DRPE) and compressive ghost imaging (CGI) techniques. In this scheme, a secret image is first transformed into a binary image with the phase-retrieval-based DRPE technique, and then encoded by a series of random amplitude patterns according to the ghost imaging (GI) principle. Compressive sensing, corrosion and expansion operations are implemented to retrieve the secret image in the decryption process. This encryption scheme takes the advantage of complementary capabilities offered by the phase-retrieval-based DRPE and GI-based encryption techniques. That is the phase-retrieval-based DRPE is used to overcome the blurring defect of the decrypted image in the GI-based encryption, and the CGI not only reduces the data amount of the ciphertext, but also enhances the security of DRPE. Computer simulation results are presented to verify the performance of the proposed encryption scheme.

  16. Wall-Current-Monitor based Ghost and Satellite Bunch Detection in the CERN PS and the LHC Accelerators

    CERN Document Server

    Steinhagen, R J; Belleman, J; Bohl, T; Damerau, H

    2012-01-01

    While most LHC detectors and instrumentation systems are optimised for a nominal bunch spacing of 25 ns, the LHC RF cavities themselves operate at the 10th harmonic of the maximum bunch frequency. Due to the beam production scheme and transfers in the injector chain, part of the nominally ‘empty’ RF buckets may contain particles, referred to as ghost or satellite bunches. These populations must be accurately quantified for high-precision experiments, luminosity calibration and control of parasitic particle encounters at the four LHC interaction points. This contribution summarises the wall-current-monitor based ghost and satellite bunch measurements in CERN’s PS and LHC accelerators. Instrumentation set-up, post-processing and achieved performance are discussed.

  17. The Ghost-Angel. On the spiritualitation of the angel and divinization of men in the islamic medieval mystic.

    Directory of Open Access Journals (Sweden)

    Rodrigo Kalmy Bolton

    2014-02-01

    Full Text Available This essay is the first part of an arqueology on governmentality in islam. Identifying the quran´s assimilation of angel Gabriel and the Holy Ghost I think that islamic medieval mystic develop an spiritualization of the angel where pneumatology and angelology seems to be the same, because the angel is not a simple server of God but a manager of man´s soul. In this way the Ghost-Angel would be consider as a dispositiv of soul´s salvation (the divinization of men and the condition of a government of itself. That´s why it challenge the formalization proposes by the islamic law (fiqh.

  18. Energy based optimization of viscous–friction dampers on cables

    International Nuclear Information System (INIS)

    Weber, F; Boston, C

    2010-01-01

    This investigation optimizes numerically a viscous–friction damper connected to a cable close to one cable anchor for fastest reduction of the total mechanical cable energy during a free vibration decay test. The optimization parameters are the viscous coefficient of the viscous part and the ratio between the friction force and displacement amplitude of the friction part of the transverse damper. Results demonstrate that an almost pure friction damper with negligibly small viscous damping generates fastest cable energy reduction over the entire decay. The ratio between the friction force and displacement amplitude of the optimal friction damper differs from that derived from the energy equivalent optimal viscous damper. The reason for this is that the nonlinearity of the friction damper causes energy spillover from the excited to higher modes of the order of 10%, i.e. cables with attached friction dampers vibrate at several frequencies. This explains why the energy equivalent approach does not yield the optimal friction damper. Analysis of the simulation data demonstrates that the optimally tuned friction damper dissipates the same energy per cycle as if each modal component of the cable were damped by its corresponding optimal linear viscous damper

  19. Energy-Based Analysis of Ultrasonically Assisted Turning

    Directory of Open Access Journals (Sweden)

    G.A. Volkov

    2011-01-01

    Full Text Available The process of ultrasonically-assisted turning (UAT is a superposition of vibration of a cutting tool on its standard movement in conventional turning (CT. The former technique has several advantages compared with the latter, one of the main being a significant decrease in the level of cutting forces. In this paper the effects observed in UAT are analysed employing ideas of dynamic fracture mechanics. The active stage of loading duration depends heavily on ultrasonic frequency and the cutting speed; he application of the fracture criterion based on the notion of incubation time makes it possible to calculate a dependence of this duration on its threshold amplitude. An estimation of energy, necessary to create a threshold pulse in the material, is made by solving the contact Hertz problem. The obtained time dependence of energy has a marked minimum. Thus, the existence of energy-efficient loading duration is demonstrated. This explains the decrease in the cutting force resulting from superimposed ultrasonic vibration. The obtained results are in agreement with experiments on ultrasonic assisted machining of aluminium and Inconel 718 alloy.

  20. Evaluation of high frequency ghost cavitation emissions for two different seismic air-gun arrays using numerical modelling

    Science.gov (United States)

    Khodabandeloo, Babak; Landrø, Martin

    2017-04-01

    Sound is deployed by marine mammals for variety of vital purposes such as finding food, communication, echolocation, etc. On the other hand human activities generate underwater noise. One major type of acoustic source is marine seismic acquisition which is carried out to image layers beneath the seabed exploiting reflected acoustic and elastic waves. Air-gun arrays are the most common and efficient marine seismic sources. Field measurements using broad band hydrophones have revealed that acoustic energies emitted by air-gun arrays contains frequencies from a few Hz up to tens of kHz. Frequencies below 200 Hz benefit seismic imaging and the rest is normally considered as wasted energy. On the other hand, the high frequency range (above 200 Hz) overlaps with hearing curves of many marine mammals and especially toothed whales and may have an impact on their behavior. A phenomenon called ghost cavitation is recently recognized to be responsible for a major part of these high frequencies (> 5 kHz). Acoustic pressure waves of individual air guns reflected from sea surface can cause the hydrostatic pressure to drop towards zero close to the source array. In these regions there is a high probability for water vapor cavity growth and subsequent collapse. We have simulated ghost cavitation cloud using numerical modelling and the results are validated by comparing with field measurements. The model is used to compare the amount of high frequency noise due to ghost cavitation for two different air gun arrays. Both of the arrays have three subarrays but the array distance for the one with 2730 in3 air volume is 6 meters and for the slightly bigger array (3250 in3 in air volume) the subarrays are separated by 8 meters. Simulation results indicate that the second array, despite larger subarray distance, generates stronger ghost cavitation signal.

  1. Determination of electric field threshold for electrofusion of erythrocyte ghosts. Comparison of pulse-first and contact-first protocols.

    OpenAIRE

    Wu, Y; Montes, J G; Sjodin, R A

    1992-01-01

    Rabbit erythrocyte ghosts were fused by means of electric pulses to determine the electrofusion thresholds for these membranes. Two protocols were used to investigate fusion events: contact-first, and pulse-first. Electrical capacitance discharge (CD) pulses were used to induce fusion. Plots of fusion yield vs peak field strength yielded curves that intersected the field strength axis at positive values (pseudothresholds) which depended on the protocol and decay half time of the pulses. It wa...

  2. Methods for reducing ghost rays on the Wolter-I focusing figures of the FOXSI rocket payload

    Science.gov (United States)

    Buitrago-Casas, Juan Camilo; Glesener, Lindsay; Christe, Steven; Ramsey, Brian; Elsner, Ronald; Courtade, Sasha; Vievering, Juliana; Subramania, Athiray; Krucker, Sam; Bale, Stuart

    2017-08-01

    In high energy solar astrophysics, imaging hard X-rays by direct focusing offers higher dynamic range and greater sensitivity compared to past techniques that used indirect imaging. The Focusing Optics X-ray Solar Imager (FOXSI) is a sounding rocket payload which uses seven sets of nested Wolter-I figured mirrors that, together with seven high-sensitive semiconductor detectors, observes the Sun in hard X-rays by direct focusing. The FOXSI rocket has successfully flown twice and is funded to fly a third time in summer 2018.The Wolter-I geometry consists of two consecutive mirrors, one paraboloid, and one hyperboloid, that reflect photons at grazing angles. Correctly focused X-rays reflect twice, once per mirror segment. For extended sources, like the Sun, off-axis photons at certain incident angles can reflect on only one mirror and still reach the focal plane, generating a pattern of single-bounce photons, or ‘ghost rays’ that can limit the sensitivity of the observation of focused X-rays. Understanding and cutting down the ghost rays on the FOXSI optics will maximize the instrument’s sensitivity of the solar faintest sources for future flights. We present an analysis of the FOXSI ghost rays based on ray-tracing simulations, as well as the effectiveness of different physical strategies to reduce them.

  3. Different forces

    CERN Multimedia

    1982-01-01

    The different forces, together with a pictorial analogy of how the exchange of particles works. The table lists the relative strength of the couplings, the quanta associated with the force fields and the bodies or phenomena in which they have a dominant role.

  4. Labor Force

    Science.gov (United States)

    Occupational Outlook Quarterly, 2010

    2010-01-01

    The labor force is the number of people aged 16 or older who are either working or looking for work. It does not include active-duty military personnel or institutionalized people, such as prison inmates. Quantifying this total supply of labor is a way of determining how big the economy can get. Labor force participation rates vary significantly…

  5. A review of solar energy based heat and power generation systems

    DEFF Research Database (Denmark)

    Modi, Anish; Bühler, Fabian; Andreasen, Jesper Graa

    2017-01-01

    The utilization of solar energy based technologies has attracted increased interest in recent times in order to satisfy the various energy demands of our society. This paper presents a thorough review of the open literature on solar energy based heat and power plants. In order to limit the scope ...

  6. Notch signaling and ghost cell fate in the calcifying cystig odontogenic tumor

    Directory of Open Access Journals (Sweden)

    Siar CH

    2011-11-01

    Full Text Available Abstract Notch signaling is an evolutionarily conserved mechanism that enables adjacent cells to adopt different fates. Ghost cells (GCs are anucleate cells with homogeneous pale eosinophilic cytoplasm and very pale to clear central areas (previous nucleus sites. Although GCs are present in a variety of odontogenic lesions notably the calcifying cystic odontogenic tumor (GCOT, their nature and process of formation remains elusive. The aim of this study was to investigate the role of Notch signaling in the cell fate specification of GCs in CCOT. Immunohistochemical staining for four Notch receptors (Notch1, Notch2, Notch3 and Notch4 and three ligands (Jagged1, Jagged2 and Delta1 was performed on archival tissues of five CCOT cases. Level of positivity was quantified as negative (0, mild (+, moderate (2+ and strong (3+. Results revealed that GCs demonstrated overexpression for Notch1 and Jagged1 suggesting that Notch1Jagged1 signaling might serve as the main transduction mechanism in cell fate decision for GCs in CCOT. Protein localizations were largely membranous and/or cytoplasmic. Mineralized GCs also stained positive implicating that the calcification process might be associated with upregulation of these molecules. The other Notch receptors and ligands were weak to absent in GCs and tumoral epithelium. Stromal endothelium and fibroblasts were stained variably positive.

  7. Ghost-gluon vertex in the presence of the Gribov horizon

    Science.gov (United States)

    Mintz, B. W.; Palhares, L. F.; Sorella, S. P.; Pereira, A. D.

    2018-02-01

    We consider Yang-Mills theories quantized in the Landau gauge in the presence of the Gribov horizon via the refined Gribov-Zwanziger (RGZ) framework. As the restriction of the gauge path integral to the Gribov region is taken into account, the resulting gauge field propagators display a nontrivial infrared behavior, being very close to the ones observed in lattice gauge field theory simulations. In this work, we explore a higher correlation function in the refined Gribov-Zwanziger theory: the ghost-gluon interaction vertex, at one-loop level. We show explicit compatibility with kinematical constraints, as required by the Ward identities of the theory, and obtain analytical expressions in the limit of vanishing gluon momentum. We find that the RGZ results are nontrivial in the infrared regime, being compatible with lattice Yang-Mills simulations in both SU(2) and SU(3), as well as with solutions from Schwinger-Dyson equations in different truncation schemes, Functional Renormalization Group analysis, and the renormalization group-improved Curci-Ferrari model.

  8. Spectacular Attractions: Museums, Audio-Visuals and the Ghosts of Memory

    Directory of Open Access Journals (Sweden)

    Mandelli Elisa

    2015-12-01

    Full Text Available In the last decades, moving images have become a common feature not only in art museums, but also in a wide range of institutions devoted to the conservation and transmission of memory. This paper focuses on the role of audio-visuals in the exhibition design of history and memory museums, arguing that they are privileged means to achieve the spectacular effects and the visitors’ emotional and “experiential” engagement that constitute the main objective of contemporary museums. I will discuss this topic through the concept of “cinematic attraction,” claiming that when embedded in displays, films and moving images often produce spectacular mises en scène with immersive effects, creating wonder and astonishment, and involving visitors on an emotional, visceral and physical level. Moreover, I will consider the diffusion of audio-visual witnesses of real or imaginary historical characters, presented in Phantasmagoria-like displays that simulate ghostly and uncanny apparitions, creating an ambiguous and often problematic coexistence of truth and illusion, subjectivity and objectivity, facts and imagination.

  9. Magnetic Au Nanoparticles on Archaeal S-Layer Ghosts as Templates

    Directory of Open Access Journals (Sweden)

    Sonja Selenska-Pobell

    2011-10-01

    Full Text Available Cell‐ghosts representing empty cells of the archaeon Sulfolobus acidocaldarius, consisting only of their highly ordered and unusually stable outermost proteinaceous surface layer (S‐layer, were used as templates for Au nanoparticles fabrication. The properties of these archaeal Au nanoparticles differ significantly from those produced earlier by us onto bacterial S‐layer sheets. The archaeal Au nanoparticles, with a size of about 2.5 nm, consist exclusively of metallic Au(0, while those produced on the bacterial S‐layer had a size of about 4 nm and represented a mixture of Au(0 and Au(III in the ratio of 40 to 60 %. The most impressive feature of the archaeal Au nanoparticles is that they are strongly paramagnetic, in contrast to the bacterial ones and also to bulk gold. SQUID magnetometry and XMCD measurements demonstrated that the archaeal Au nanoparticles possess a rather large magnetic moment of about 0.1 µB/atom. HR‐ TEM‐EDX analysis revealed that the archaeal Au nanoparticles are linked to the sulfur atoms of the thiol groups of the amino acid cysteine, characteristic only for archaeal S‐layers. This is the first study demonstrating the formation of such unusually strong magnetic Au nanoparticles on a non‐modified archaeal S‐layer.

  10. The ghost of herbivory past: slow defence relaxation in the chlorophyte Scenedesmus obliquus

    Directory of Open Access Journals (Sweden)

    Jacobus VIJVERBERG

    2009-08-01

    Full Text Available The freshwater chlorophyte Scenedesmus obliquus (Turpin Kützing produces colonies as an inducible defence against herbivores. We investigated the dynamics of Scenedesmus colony formation and disintegration in response to the density of the herbivorous rotifer Brachionus calyciflorus in large-scale mesocosms. Additional bioassays were performed to investigate Scenedesmus colony disintegration under different light regimes. In the mesocosm experiment, colony formation took place rapidly, but relaxation towards the initial size took relatively long (>10 d after cessation of herbivory. In the bioassays, in the absence of infochemicals, colonies disintegrated almost immediately in the dark (1-1.5 d, within 4 d under a photoperiod of 16:8 (L:D and between 8 and 12 days under full light. Colony disintegration times in the mesocosm experiment were substantially longer as compared to treatments with the same photoperiod (L:D 16:8 in the bioassays. So after a peak of herbivory, the 'ghost of herbivory past', i.e. the remaining infochemicals, may continue to induce colony formation, causing an additional lengthening of colony disintegration times and associated fitness costs (higher sedimentation loss rates. This indicates that costs of colony formation are not only important during the induction phase, but may be even more important during the relaxation phase. We compared these sedimentation costs to the costs of herbivory for differently sized Scenedesmus, and found a clear trade-off pattern for these costs.

  11. THE GHOSTS SURVEY. I. HUBBLE SPACE TELESCOPE ADVANCED CAMERA FOR SURVEYS DATA

    International Nuclear Information System (INIS)

    Radburn-Smith, D. J.; Dalcanton, J. J.; De Jong, R. S.; Streich, D.; Vlajic, M.; Seth, A. C.; Bailin, J.; Bell, E. F.; Brown, T. M.; Ferguson, H. C.; Goudfrooij, P.; Holfeltz, S.; Bullock, J. S.; Courteau, S.; Sick, J.; Holwerda, B. W.; Purcell, C.; Zucker, D. B.

    2011-01-01

    We present an overview of the GHOSTS survey, the largest study to date of the resolved stellar populations in the outskirts of disk galaxies. The sample consists of 14 disk galaxies within 17 Mpc, whose outer disks and halos are imaged with the Hubble Space Telescope Advanced Camera for Surveys (ACS). In the first paper of this series, we describe the sample, explore the benefits of using resolved stellar populations, and discuss our ACS F606W and F814W photometry. We use artificial star tests to assess completeness and use overlapping regions to estimate photometric uncertainties. The median depth of the survey at 50% completeness is 2.7 mag below the tip of the red giant branch (TRGB). We comprehensively explore and parameterize contamination from unresolved background galaxies and foreground stars using archival fields of high-redshift ACS observations. Left uncorrected, these would account for 10 0.65xF814W-19.0 detections per mag per arcsec 2 . We therefore identify several selection criteria that typically remove 95% of the contaminants. Even with these culls, background galaxies are a significant limitation to the surface brightness detection limit which, for this survey, is typically V ∼ 30 mag arcsec -2 . The resulting photometric catalogs are publicly available and contain some 3.1 million stars across 76 ACS fields, predominantly of low extinction. The uniform magnitudes of TRGB stars in these fields enable galaxy distance estimates with 2%-7% accuracy.

  12. Ghost Particle Velocimetry implementation in millimeters devices and comparison with μPIV

    Science.gov (United States)

    Riccomi, Marco; Alberini, Federico; Brunazzi, Elisabetta; Vigolo, Daniele

    2016-11-01

    Micro/milli-fluidic devices are becoming an important reference for several disciplines and are quickly increasing their applications in scientific, as well as industrial, environment. As a consequence, the development of techniques able to analyse these kinds of systems is required to allow their progress. Here we show the implementation of the Ghost Particle Velocimetry (GPV) for the flow velocity field investigation in milli-fluidic devices. This innovative technique has been recently introduced, and has been already proven to be useful in describing rapid phenomenon at a small scale. In this work, the GPV has been used to characterize the trapping of light suspended material in a branching junction. Experiments have been performed to identify the flow velocity field close to a millimeters scale T-junction, at different Reynolds numbers. Particularly interesting are the complex structures, such as vortices and recirculation zones, induced by the vortex breakdown phenomenon. The results obtained have been deeply validated and compared with the well-established μPIV, highlighting the differences in terms of qualitative and quantitative parameters. A performance comparison has been designed to underline the strengths and weaknesses of the two experimental techniques.

  13. Ghosts in the looking-glass of our minds”: i detective dell’occulto

    Directory of Open Access Journals (Sweden)

    Maurizio Ascari

    2012-11-01

    Full Text Available Although Sherlock Holmes has been considered as the prototype of the scientific detective, Doyle’s curiosity notoriously embraced paranormal phenomena such as spiritualism, clairvoyance and even the existence of fairies… Far from being atypical, this attitude is revealing of the tension between the natural and the supernatural that marked the decades straddling across the nineteenth and twentieth centuries, when the advancement of science was regarded by many as conducive to a better understanding of what had been previously consigned to superstition. Given this climate of syncretism, it does not come as a surprise that those years saw the development of a hybrid subgenre in which ‘psychic detectives’ investigate cases often involving supernatural agencies. This article discusses four collections of stories of psychic detection published at the turn of the century, together with their reception in the Golden Age period, finally hinting at the renewed popularity psychic detectives have recently attained thanks to tv series such as Medium (2005-11 and Ghost Whisperer (2005-10.

  14. Derivation of regularized Grad's moment system from kinetic equations: modes, ghosts and non-Markov fluxes

    Science.gov (United States)

    Karlin, Ilya

    2018-04-01

    Derivation of the dynamic correction to Grad's moment system from kinetic equations (regularized Grad's 13 moment system, or R13) is revisited. The R13 distribution function is found as a superposition of eight modes. Three primary modes, known from the previous derivation (Karlin et al. 1998 Phys. Rev. E 57, 1668-1672. (doi:10.1103/PhysRevE.57.1668)), are extended into the nonlinear parameter domain. Three essentially nonlinear modes are identified, and two ghost modes which do not contribute to the R13 fluxes are revealed. The eight-mode structure of the R13 distribution function implies partition of R13 fluxes into two types of contributions: dissipative fluxes (both linear and nonlinear) and nonlinear streamline convective fluxes. Physical interpretation of the latter non-dissipative and non-local in time effect is discussed. A non-perturbative R13-type solution is demonstrated for a simple Lorentz scattering kinetic model. The results of this study clarify the intrinsic structure of the R13 system. This article is part of the theme issue `Hilbert's sixth problem'.

  15. MEMOIRS OF A GIRLHOOD AMONG GHOSTS WRITTEN BY MAXINE HONG KINGSTON

    Directory of Open Access Journals (Sweden)

    Desy Khrisdiyanti

    2017-04-01

    Full Text Available Every generation brings their own voice, no matter how rigorous the elderly retain the cultural values of their ancestors. A novel written by Maxine Hong Kingston –a Chinese American descent- entitled The Woman Warrior: Memoirs of a Girlhood among Ghosts, portraits her struggle to get her own identity between her Chinese and her American identity. A descriptive library research was conducted to reveal the reasons that the Chinese American descents struggled to survive in between both lives. Interdisciplinary approaches are employed to analyze the data in order to obtain comprehensive analysis, among others: psychological, sociological, and literary approaches. Psychological approach is to expound the emotional perspectives of the character shifts. Sociological approach is applied to discuss the socialization process and its connection to the character shift. Likewise, literary approach is to uncover the structure of the work which was the result of Kingston‘s experience and reflection of the phenomena in her real life. The research concludes that the personality change of the Chinese American descents is due to their historical, social, economical, and educational experience. Furthermore, the descents tend to transform their traits closer to the white‘s, which have been their counterpart in the new land, than to their ancestries‘.

  16. Interferences, ghost images and other quantum correlations according to stochastic optics

    International Nuclear Information System (INIS)

    Fonseca da Silva, Luciano; Dechoum, Kaled

    2012-01-01

    There are an extensive variety of experiments in quantum optics that emphasize the non-local character of the coincidence measurements recorded by spatially separated photocounters. These are the cases of ghost image and other interference experiments based on correlated photons produced in, for instance, the process of parametric down-conversion or photon cascades. We propose to analyse some of these correlations in the light of stochastic optics, a local formalism based on classical electrodynamics with added background fluctuations that simulate the vacuum field of quantum electrodynamics, and raise the following question: can these experiments be used to distinguish between quantum entanglement and classical correlations? - Highlights: ► We analyse some quantum correlations in the light of stochastic optics. ► We study how vacuum fluctuations can rule quantum correlations. ► Many criteria cannot be considered a boundary between quantum and classical theories. ► Non-locality is a misused term in relation to many observed experiments.

  17. A Value Chain Analysis of ghost nets in the Arafura Sea: identifying trans-boundary stakeholders, intervention points and livelihood trade-offs.

    Science.gov (United States)

    Butler, J R A; Gunn, R; Berry, H L; Wagey, G A; Hardesty, B D; Wilcox, C

    2013-07-15

    Lost or discarded fishing nets are a significant component of marine debris which has trans-boundary impacts in large marine ecosystems. Such 'ghost nets' cause the by-catch of marine fauna and require retrieval from coastlines where they wash up. Identifying the causes of discarded nets and feasible intervention points requires analysis of a complex value chain and the stakeholders within it, yet no studies have attempted this. In this paper we combine Value Chain Analysis, commonly applied to understand value-adding for a commodity, with elements of Life Cycle Assessment and social network analysis to examine the drivers, stakeholders, economic, environmental and social costs and benefits in the life of a trawl net. We use the Arafura Sea as a case study, which is shared by Indonesia, Papua New Guinea and Australia, and is the focus of a Trans-boundary Diagnostic Assessment (TDA) within the Arafura-Timor Seas Ecosystem Action program (ATSEA). We follow a trawl net through four sub-systems: manufacture of webbing in South Korea, fishing and loss by an Indonesian vessel, retrieval as ghost net on the northern Australian coastline by Indigenous rangers, and disposal or re-cycling as 'GhostNet Art' by Indigenous artists. Primary stakeholders along the value chain incur economic and social benefits, and economic and environmental costs. There is an anomaly in the chain between Indonesian fishermen and Indigenous rangers, artists and communities due to the lack of market linkages between these primary stakeholders. The first 'nexus of influence' where reductions in net losses and environmental costs can be achieved is through interactions between GhostNets Australia, the World Wide Fund for Nature and the Australian Government, which can influence Indonesian fishery management institutions and fishing crews. The second nexus is via the international art market which by publicising GhostNet Art can raise awareness amongst fish consumers about the impacts of ghost nets

  18. Toll-like receptor variation in the bottlenecked population of the Seychelles warbler: computer simulations see the 'ghost of selection past' and quantify the 'drift debt'.

    Science.gov (United States)

    Gilroy, D L; Phillips, K P; Richardson, D S; van Oosterhout, C

    2017-07-01

    Balancing selection can maintain immunogenetic variation within host populations, but detecting its signal in a postbottlenecked population is challenging due to the potentially overriding effects of drift. Toll-like receptor genes (TLRs) play a fundamental role in vertebrate immune defence and are predicted to be under balancing selection. We previously characterized variation at TLR loci in the Seychelles warbler (Acrocephalus sechellensis), an endemic passerine that has undergone a historical bottleneck. Five of seven TLR loci were polymorphic, which is in sharp contrast to the low genomewide variation observed. However, standard population genetic statistical methods failed to detect a contemporary signature of selection at any TLR locus. We examined whether the observed TLR polymorphism could be explained by neutral evolution, simulating the population's demography in the software DIYABC. This showed that the posterior distributions of mutation rates had to be unrealistically high to explain the observed genetic variation. We then conducted simulations with an agent-based model using typical values for the mutation rate, which indicated that weak balancing selection has acted on the three TLR genes. The model was able to detect evidence of past selection elevating TLR polymorphism in the prebottleneck populations, but was unable to discern any effects of balancing selection in the contemporary population. Our results show drift is the overriding evolutionary force that has shaped TLR variation in the contemporary Seychelles warbler population, and the observed TLR polymorphisms might be merely the 'ghost of selection past'. Forecast models predict immunogenetic variation in this species will continue to be eroded in the absence of contemporary balancing selection. Such 'drift debt' occurs when a gene pool has not yet reached its new equilibrium level of polymorphism, and this loss could be an important threat to many recently bottlenecked populations. © 2017

  19. Nuclear forces

    International Nuclear Information System (INIS)

    Holinde, K.

    1990-01-01

    In this paper the present status of the meson theory of nuclear forces is reviewed. After some introductory remarks about the relevance of the meson exchange concept in the era of QCD and the empirical features of the NN interaction, the exciting history of nuclear forces is briefly outlined. In the main part, the author gives the basic physical ideas and sketch the derivation of the one-boson-exchange model of the nuclear force, in the Feynman approach. Secondly we describe, in a qualitative way, various necessary extensions, leading to the Bonn model of the N interaction. Finally, points to some interesting pen questions connected with the extended quark structure of the hadrons, which are topics of current research activity

  20. Combined study of the gluon and ghost condensates μ2> and abccbcc> in Euclidean SU(2) Yang-Mills theory in the Landau gauge

    International Nuclear Information System (INIS)

    Capri, M.A.L.; Lemes, V.E.R.; Sobreiro, R.F.; Sorella, S.P.; Dudal, D.; Verschelde, H.; Gracey, J.A.

    2006-01-01

    The ghost condensate abc c b c c > is considered together with the gluon condensate μ 2 > in SU(2) Euclidean Yang-Mills theories quantized in the Landau gauge. The vacuum polarization ceases to be transverse due to the nonvanishing condensate abc c b c c >. The gluon propagator itself remains transverse. By polarization effects, this ghost condensate induces then a splitting in the gluon mass parameter, which is dynamically generated through μ 2 >. The obtained effective masses are real when μ 2 > is included in the analysis. In the absence of μ 2 >, the already known result that the ghost condensate induces effective tachyonic masses is recovered. At the one-loop level, we find that the effective diagonal mass becomes smaller than the off-diagonal one. This might serve as an indication for some kind of Abelian dominance in the Landau gauge, similar to what happens in the maximal Abelian gauge

  1. Ghost poles in the nucleon propagator in the linear σ model approach and its role in πN low-energy theorems

    International Nuclear Information System (INIS)

    Da Rocha, C.A.; Wilets, L.

    1997-01-01

    Complex mass poles, or ghost poles, are present in the Hartree-Fock solution of the Schwinger-Dyson equation for the nucleon propagator in renormalizable models with Yukawa-type meson-nucleon couplings, as shown many years ago by Brown, Puff and Wilets (BPW). These ghosts violate basic theorems of quantum field theory and their origin is related to the ultraviolet behavior of the model interactions. Recently, Krein et.al, proved that the ghosts disappear when vertex corrections are included in a self-consistent way, softening the interaction sufficiently in the ultraviolet region. In previous studies of πN scattering using ''dressed'' nucleon propagator and bare vertices, did by Nutt and Wilets in the 70's (NW), it was found that if these poles are explicitly included, the value of the isospin-even amplitude A (+) is satisfied within 20% at threshold. The absence of a theoretical explanation for the ghosts and the lack of chiral symmetry in these previous studies led us to re-investigate the subject using the approach of the linear σ-model and study the interplay of low-energy theorems for πN scattering and ghost poles. For bare interaction vertices we find that ghosts are present in this model as well and that the A (+) value is badly described. As a first approach to remove these complex poles, we dress the vertices with phenomenological form factors and a reasonable agreement with experiment is achieved. In order to fix the two cutoff parameters, we use the A (+) value for the chiral limit (m π →0) and the experimental value of the isoscalar scattering length. Finally, we test our model by calculating the phase shifts for the S waves and we find a good agreement at threshold. (orig.)

  2. Growth, inter- and intraspecific variation, palaeobiogeography, taphonomy and systematics of the Cenozoic ghost shrimp Glypturus

    Science.gov (United States)

    Klompmaker, Adiël A.; Hyžný, Matúš; Portell, Roger W.; Kowalewski, Michał

    2015-01-01

    Studies in systematic palaeontology are greatly aided when numerous, well-preserved specimens are available so that quantitative methods can be used to substantiate qualitative observations. This is often not the case for fossil decapod crustaceans due to their relatively low preservation potential. Here, we examined primarily two large collections of the well-preserved ghost shrimp Glypturus from the Holo-Pleistocene of Panama and the late Miocene of Florida. Using descriptive, bivariate, multivariate and geometric morphometric methods, two new species are described based on appendage material: Glypturus panamacanalensis sp. nov. and G. sikesi sp. nov. New characters are identified, and size-related and intraspecific variation are assessed for these taxa and modern G. acanthochirus. Taxonomic placement of single specimens from other localities was confirmed by multivariate methods. Furthermore, Glypturus is revised, especially with regard to Western Atlantic species that inhabited both carbonate and siliciclastic environments. Callianassa anguillensis, C. latidigata, and Neocallichirus? quisquellanus are referred to as Glypturus sp. until more material is available to determine the validity of these species. Diversity within Glypturus may thus be underestimated, thereby also impacting the assessment of phylogenetic relationships. Minor propodi appear under-represented relative to major propodi, suggesting a taphonomic bias. Single specimens of interest include a specimen of G. panamacanalensis sp. nov. exhibiting a peculiar swelling in the fixed finger and another showing damage on the propodal upper margin, suggesting failed predation or antagonistic behaviour. Glypturus is first found in the Oligocene in the Western Atlantic and may have expanded its palaeobiogeographical range since the Miocene. The genus was still present on the Pacific side of the Isthmus of Panama in the Holo-Pleistocene, but is only known from the Western Atlantic today, suggesting a

  3. The Online Body Breaks Out? Asence, Ghosts, Cyborgs, Gender, Polarity and Politics

    Directory of Open Access Journals (Sweden)

    Jonathan Marshall

    2004-01-01

    Full Text Available Online bodies, or cyber-bodies, seem to be constantly involved in issues of boundaries. This paper explores some of those issues. A brief outline of some offline boundary anxieties is given, such as being overwhelmed by germs, work or the foreign. It is then argued that boundaries online are even more porous and unclear. The term 'asence' is introduced to point to an existential anxiety about the ambiguities of being suspended between presence and absence. It is shown that asence and the problems around the sustaining of mood, explain some aspects of online life including flame, netsex, and the intensity of mourning. A sense of online presence may only be able to arise through asencing of the offline body and its discomforts. Ethnographic examples come from the Mailing List Cybermind. The vagueness of the virtual body is compared with other common western constructions of virtual bodies such as ghosts, and it is suggested that such constructions still have strength despite widespread cynicism about mind (online and body (offline splits. Computers seem to have become a place for haunting and disembodiment, which produces confusions when it becomes time to act offline. Other useful metaphors may not be able to be used. Haraway's model of the Cyborg is often claimed to overcome these problems, collapsing borders between human and machine, human and animal, sentient and non-sentient, female and male. However it seems to fail in these tasks because the cyborg myth has its own directions independent of our intentions, and this myth is directed by the discourse of techno-capitalism. It may prove more useful to strategically exaggerate oppositions, or to explore their ambiguities, than to dampen them by theoretical hybridisation.

  4. Ghost-in-the-Machine reveals human social signals for human-robot interaction.

    Science.gov (United States)

    Loth, Sebastian; Jettka, Katharina; Giuliani, Manuel; de Ruiter, Jan P

    2015-01-01

    We used a new method called "Ghost-in-the-Machine" (GiM) to investigate social interactions with a robotic bartender taking orders for drinks and serving them. Using the GiM paradigm allowed us to identify how human participants recognize the intentions of customers on the basis of the output of the robotic recognizers. Specifically, we measured which recognizer modalities (e.g., speech, the distance to the bar) were relevant at different stages of the interaction. This provided insights into human social behavior necessary for the development of socially competent robots. When initiating the drink-order interaction, the most important recognizers were those based on computer vision. When drink orders were being placed, however, the most important information source was the speech recognition. Interestingly, the participants used only a subset of the available information, focussing only on a few relevant recognizers while ignoring others. This reduced the risk of acting on erroneous sensor data and enabled them to complete service interactions more swiftly than a robot using all available sensor data. We also investigated socially appropriate response strategies. In their responses, the participants preferred to use the same modality as the customer's requests, e.g., they tended to respond verbally to verbal requests. Also, they added redundancy to their responses, for instance by using echo questions. We argue that incorporating the social strategies discovered with the GiM paradigm in multimodal grammars of human-robot interactions improves the robustness and the ease-of-use of these interactions, and therefore provides a smoother user experience.

  5. Ghost-in-the-Machine reveals human social signals for human–robot interaction

    Science.gov (United States)

    Loth, Sebastian; Jettka, Katharina; Giuliani, Manuel; de Ruiter, Jan P.

    2015-01-01

    We used a new method called “Ghost-in-the-Machine” (GiM) to investigate social interactions with a robotic bartender taking orders for drinks and serving them. Using the GiM paradigm allowed us to identify how human participants recognize the intentions of customers on the basis of the output of the robotic recognizers. Specifically, we measured which recognizer modalities (e.g., speech, the distance to the bar) were relevant at different stages of the interaction. This provided insights into human social behavior necessary for the development of socially competent robots. When initiating the drink-order interaction, the most important recognizers were those based on computer vision. When drink orders were being placed, however, the most important information source was the speech recognition. Interestingly, the participants used only a subset of the available information, focussing only on a few relevant recognizers while ignoring others. This reduced the risk of acting on erroneous sensor data and enabled them to complete service interactions more swiftly than a robot using all available sensor data. We also investigated socially appropriate response strategies. In their responses, the participants preferred to use the same modality as the customer’s requests, e.g., they tended to respond verbally to verbal requests. Also, they added redundancy to their responses, for instance by using echo questions. We argue that incorporating the social strategies discovered with the GiM paradigm in multimodal grammars of human–robot interactions improves the robustness and the ease-of-use of these interactions, and therefore provides a smoother user experience. PMID:26582998

  6. A method to correct sampling ghosts in historic near-infrared Fourier transform spectrometer (FTS) measurements

    Science.gov (United States)

    Dohe, S.; Sherlock, V.; Hase, F.; Gisi, M.; Robinson, J.; Sepúlveda, E.; Schneider, M.; Blumenstock, T.

    2013-08-01

    The Total Carbon Column Observing Network (TCCON) has been established to provide ground-based remote sensing measurements of the column-averaged dry air mole fractions (DMF) of key greenhouse gases. To ensure network-wide consistency, biases between Fourier transform spectrometers at different sites have to be well controlled. Errors in interferogram sampling can introduce significant biases in retrievals. In this study we investigate a two-step scheme to correct these errors. In the first step the laser sampling error (LSE) is estimated by determining the sampling shift which minimises the magnitude of the signal intensity in selected, fully absorbed regions of the solar spectrum. The LSE is estimated for every day with measurements which meet certain selection criteria to derive the site-specific time series of the LSEs. In the second step, this sequence of LSEs is used to resample all the interferograms acquired at the site, and hence correct the sampling errors. Measurements acquired at the Izaña and Lauder TCCON sites are used to demonstrate the method. At both sites the sampling error histories show changes in LSE due to instrument interventions (e.g. realignment). Estimated LSEs are in good agreement with sampling errors inferred from the ratio of primary and ghost spectral signatures in optically bandpass-limited tungsten lamp spectra acquired at Lauder. The original time series of Xair and XCO2 (XY: column-averaged DMF of the target gas Y) at both sites show discrepancies of 0.2-0.5% due to changes in the LSE associated with instrument interventions or changes in the measurement sample rate. After resampling, discrepancies are reduced to 0.1% or less at Lauder and 0.2% at Izaña. In the latter case, coincident changes in interferometer alignment may also have contributed to the residual difference. In the future the proposed method will be used to correct historical spectra at all TCCON sites.

  7. A method to correct sampling ghosts in historic near-infrared Fourier transform spectrometer (FTS measurements

    Directory of Open Access Journals (Sweden)

    S. Dohe

    2013-08-01

    Full Text Available The Total Carbon Column Observing Network (TCCON has been established to provide ground-based remote sensing measurements of the column-averaged dry air mole fractions (DMF of key greenhouse gases. To ensure network-wide consistency, biases between Fourier transform spectrometers at different sites have to be well controlled. Errors in interferogram sampling can introduce significant biases in retrievals. In this study we investigate a two-step scheme to correct these errors. In the first step the laser sampling error (LSE is estimated by determining the sampling shift which minimises the magnitude of the signal intensity in selected, fully absorbed regions of the solar spectrum. The LSE is estimated for every day with measurements which meet certain selection criteria to derive the site-specific time series of the LSEs. In the second step, this sequence of LSEs is used to resample all the interferograms acquired at the site, and hence correct the sampling errors. Measurements acquired at the Izaña and Lauder TCCON sites are used to demonstrate the method. At both sites the sampling error histories show changes in LSE due to instrument interventions (e.g. realignment. Estimated LSEs are in good agreement with sampling errors inferred from the ratio of primary and ghost spectral signatures in optically bandpass-limited tungsten lamp spectra acquired at Lauder. The original time series of Xair and XCO2 (XY: column-averaged DMF of the target gas Y at both sites show discrepancies of 0.2–0.5% due to changes in the LSE associated with instrument interventions or changes in the measurement sample rate. After resampling, discrepancies are reduced to 0.1% or less at Lauder and 0.2% at Izaña. In the latter case, coincident changes in interferometer alignment may also have contributed to the residual difference. In the future the proposed method will be used to correct historical spectra at all TCCON sites.

  8. Tempo e percezione in The Body Artist di Don DeLillo e Ghost Trio di Samuel Beckett

    Directory of Open Access Journals (Sweden)

    Davide Barbuscia

    2013-03-01

    Full Text Available This essay provides a critical analysis of Don DeLillo’s novel The Body Artist and Samuel Beckett’s work for television Ghost Trio. In particular it analyses the representation of time and its perception in both these works, highlighting some shared aesthetic modalities such as their attempt to depict duration through a poetics of slow motion. The essay also foregrounds how both these works give narrative form to Merleau-Ponty’s understanding of ‘time as its perception’.

  9. Species profiles: Life histories and environmental requirements of coastal fishes and invertebrates (Pacific Northwest)--ghost and blue mud shrimp

    Science.gov (United States)

    Hornig, S.; Sterling, A.; Smith, Styles

    1989-01-01

    Geographic range: The ghost shrimp is found in intertidal areas along the west coast of North America from Mutiny Bay, Alaska, to the mouth of the Tijuana River, San Diego County, California; MacGinitie (1934) and Ricketts and Calvin (1968) reported finding specimens as far south as El Estuario de Punto Banda, Baja California Norte, Mexico. The blue mud shrimp is found from southeastern Alaska to San Quentin Bay (Bahia de San Quentin) in Baja California Norte. The general distribution of the two species in the Pacific Northwest is identical (Figure 3).

  10. Thermal and ghost reflection modeling for a 180-deg. field-of-view long-wave infrared lens

    Science.gov (United States)

    Shi, Weimin; Couture, Michael E.

    2001-03-01

    Optics 1, Inc. has successfully designed and developed a 180 degree(s) field of view long wave infrared lens for USAF/AFRL under SBIR phase I and II funded projects in support of the multi-national Programmable Integrated Ordinance Suite (PIOS) program. In this paper, a procedure is presented on how to evaluate image degradation caused by asymmetric aerodynamic dome heating. In addition, a thermal gradient model is proposed to evaluate degradation caused by axial temperature gradient throughout the entire PIOS lens. Finally, a ghost reflection analysis is demonstrated with non-sequential model.

  11. Ghost field realizations of the spinor $W_{2,s}$ strings based on the linear W(1,2,s) algebras

    OpenAIRE

    Liu, Yu-Xiao; Zhang, Li-Jie; Ren, Ji-Rong

    2005-01-01

    It has been shown that certain W algebras can be linearized by the inclusion of a spin-1 current. This Provides a way of obtaining new realizations of the W algebras. In this paper, we investigate the new ghost field realizations of the W(2,s)(s=3,4) algebras, making use of the fact that these two algebras can be linearized. We then construct the nilpotent BRST charges of the spinor non-critical W(2,s) strings with these new realizations.

  12. BURROW ARCHITECTURE OF RED GHOST CRAB OCYPODE MACROCERA (H. MILNE-EDWARDS, 1852) : A CASE STUDY IN INDIAN SUNDARBANS

    OpenAIRE

    Sourabh Kumar Dubey; Deep Chandan Chakraborty; Sudipta Chakraborty; Amalesh Choudhury

    2013-01-01

    A study on burrow architecture and burrow morphology of the red ghost crab (Ocypode macrocera) was carried out at the southern proximity of the Sagar island (21°37.973' N, to E 88° 04.195'), western sector of Indian Sundarbans that faces the regular tidal influences of Bay of Bengal. Ocypode macrocera constructs burrows that are highly species specific and used by single individual. Four types of burrow patterns were observed like ‘I’, ‘J’ ‘U’ and ‘semi-U’ type with different size...

  13. Ghost field realizations of the spinor W2,s strings based on the linear W1,2,s algebras

    International Nuclear Information System (INIS)

    Liu Yuxiao; Ren Jirong; Zhang Lijie

    2005-01-01

    It has been shown that certain W algebras can be linearized by the inclusion of a spin-1 current. This provides a way of obtaining new realizations of the W algebras. In this paper, we investigate the new ghost field realizations of the W 2,s (s=3,4) algebras, making use of the fact that these two algebras can be linearized. We then construct the nilpotent BRST charges of the spinor non-critical W 2,s strings with these new realizations. (author)

  14. BlastKOALA and GhostKOALA: KEGG Tools for Functional Characterization of Genome and Metagenome Sequences.

    Science.gov (United States)

    Kanehisa, Minoru; Sato, Yoko; Morishima, Kanae

    2016-02-22

    BlastKOALA and GhostKOALA are automatic annotation servers for genome and metagenome sequences, which perform KO (KEGG Orthology) assignments to characterize individual gene functions and reconstruct KEGG pathways, BRITE hierarchies and KEGG modules to infer high-level functions of the organism or the ecosystem. Both servers are made freely available at the KEGG Web site (http://www.kegg.jp/blastkoala/). In BlastKOALA, the KO assignment is performed by a modified version of the internally used KOALA algorithm after the BLAST search against a non-redundant dataset of pangenome sequences at the species, genus or family level, which is generated from the KEGG GENES database by retaining the KO content of each taxonomic category. In GhostKOALA, which utilizes more rapid GHOSTX for database search and is suitable for metagenome annotation, the pangenome dataset is supplemented with Cd-hit clusters including those for viral genes. The result files may be downloaded and manipulated for further KEGG Mapper analysis, such as comparative pathway analysis using multiple BlastKOALA results. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  15. The Ghost in the Machine: Fracking in the Earth's Complex Brittle Crust

    Science.gov (United States)

    Malin, P. E.

    2015-12-01

    This paper discusses in the impact of complex rock properties on practical applications like fracking and its associated seismic emissions. A variety of borehole measurements show that the complex physical properties of the upper crust cannot be characterized by averages on any scale. Instead they appear to follow 3 empirical rule: a power law distribution in physical scales, a lognormal distribution in populations, and a direct relation between changes in porosity and log(permeability). These rules can be directly related to the presence of fluid rich and seismically active fractures - from mineral grains to fault segments. (These are the "ghosts" referred to in the title.) In other physical systems, such behaviors arise on the boundaries of phase changes, and are studied as "critical state physics". In analogy to the 4 phases of water, crustal rocks progress upward from a un-fractured, ductile lower crust to nearly cohesionless surface alluvium. The crust in between is in an unstable transition. It is in this layer methods such as hydrofracking operate - be they in Oil and Gas, geothermal, or mining. As a result, nothing is predictable in these systems. Crustal models have conventionally been constructed assuming that in situ permeability and related properties are normally distributed. This approach is consistent with the use of short scale-length cores and logs to estimate properties. However, reservoir-scale flow data show that they are better fit to lognormal distributions. Such "long tail" distributions are observed for well productivity, ore vein grades, and induced seismic signals. Outcrop and well-log data show that many rock properties also show a power-law-type variation in scale lengths. In terms of Fourier power spectra, if peaks per km is k, then their power is proportional to 1/k. The source of this variation is related to pore-space connectivity, beginning with grain-fractures. We then show that a passive seismic method, Tomographic Fracture

  16. An A/r/tographic Inquiry of a Silenced First Nation Ancestry, Hauntology, G(hosts) and Art(works): An Exhibition Catalogue

    Science.gov (United States)

    Cloutier, Geneviève

    2016-01-01

    As a hauntological artist, I deconstruct my silenced First Nation Wolastoqiyik (Maliseet) ancestry and look towards the intergenerational narratives of my grandmother, mother, and I. Employing the methodology of a/r/tography, the intersection of autobiography and art-making, I utilize diverse art forms to find that g(hosts) reside amongst spaces…

  17. The weathered Carboniferous Limestone at Bullslaughter Bay, South Wales: the first example of ghost-rock recorded in the British Isles

    Czech Academy of Sciences Publication Activity Database

    Rowberry, Matthew David; Battiau-Queney, Y.; Walsh, P.; Blažejowski, B.; Bout-Roumazeilles, V.; Trentesaux, A.; Křížová, L.; Griffiths, H.

    2014-01-01

    Roč. 17, č. 1 (2014), s. 33-42 ISSN 1374-8505 Institutional research plan: CEZ:AV0Z30460519 Keywords : deep weathering * saprolite * ghost -rock * Gash Breccia Subject RIV: DE - Earth Magnetism, Geodesy, Geography Impact factor: 0.782, year: 2014 http://popups.ulg.ac.be/1374-8505/index.php?id=4353&file=1&pid=4150

  18. Australia Ama Ata Aidoo's Diagnose and Representation of the Dilemma of the African American Diaspora in Her Play "Dilemma of a Ghost"

    Science.gov (United States)

    Al-Khafaji, Ammar Shamil Kadhim

    2018-01-01

    The research investigates in details about the influence of cultural differences in Postcolonial Ghana as presented in Ama Ata Aidoo's "Dilemma of a Ghost". The play centers on the cross cultural marriage of young couple; Ato Yawson, a Ghanaian who recently completed his studies in the United States and returns home, and Eulali, his…

  19. Ghost microstructure evolution and identification in the coarse grain heat affected zone of 2.25Cr-1Mo-V-Ti steel using tint etching

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kyongwoon [Corporate R& D Institute, Doosan Heavy Industries & Construction,Gwigok-dong, Gyeongsangnam-do Seongsan-gu, Changwon-si 642-792 (Korea, Republic of); Lee, Seonghyeong; Na, Hyesung [School of Materials Science and Engineering, Pusan National University, San 30 Jangjeon-dong, Geumjeong-gu, Busan 609-735 (Korea, Republic of); Kang, Chungyun, E-mail: kangcy@pusan.ac.kr [School of Materials Science and Engineering, Pusan National University, San 30 Jangjeon-dong, Geumjeong-gu, Busan 609-735 (Korea, Republic of)

    2016-11-15

    Microstructural characteristics of the CGHAZ (coarse grained heat affected zone) made of the 2.25Cr-1Mo-V-Ti material for the thermal power plant boiler tube were discussed using the technique of tint etching. To conduct the micro structural characterization, the sample on which CGHAZ was produced by using a high temperature thermal cycle simulator, Gleeble 3500 equipment was used for comparative analyses using the existing Nital etching (ASTM E407-74) and the alkaline etching (ASTM E40785). The latter was used to observe a specific phase. For the microstructure on which the alkaline etching was experimented, the shape of a black strip (Ghost microstructure) in a few microns was observed, which was not observed from the Nital etching. It was found from the phase identifications based EPMA, EBSD and TEM experiments that the image of the black strip in a few microns represented the alpha phase in which C, Cr and Mo became segregated. In addition, it was verified that austenite and M{sub 23}C{sub 6} phase were present around the segregated zone. Based on such results, the mechanism by which the image of the black strip in a few microns was formed at the CGHAZ. In this study, we have investigated the mechanism of the appeared black strip in the CGHAZ. - Highlights: •Ghost microstructure was observed which was not observed from the nital etching. •Ghost microstructure has high concentrations of carbon and molybdenum than matrix. •Schematic illustration proposed of why Ghost microstructure was generated. •Ghost microstructure caused by partial dissolution of M{sub 23}C{sub 6} precipitation.

  20. SPH for impact force and ricochet behavior of water-entry bodies

    Science.gov (United States)

    Omidvar, Pourya; Farghadani, Omid; Nikeghbali, Pooyan

    The numerical modeling of fluid interaction with a bouncing body has many applications in scientific and engineering application. In this paper, the problem of water impact of a body on free-surface is investigated, where the fixed ghost boundary condition is added to the open source code SPHysics2D1 to rectify the oscillations in pressure distributions with the repulsive boundary condition. First, after introducing the methodology of SPH and the option of boundary conditions, the still water problem is simulated using two types of boundary conditions. It is shown that the fixed ghost boundary condition gives a better result for a hydrostatics pressure. Then, the dam-break problem, which is a bench mark test case in SPH, is simulated and compared with available data. In order to show the behavior of the hydrostatics forces on bodies, a fix/floating cylinder is placed on free surface looking carefully at the force and heaving profile. Finally, the impact of a body on free-surface is successfully simulated for different impact angles and velocities.

  1. Coriolis Force

    Science.gov (United States)

    Marciuc, Daly; Solschi, Viorel

    2017-04-01

    Understanding the Coriolis effect is essential for explaining the movement of air masses and ocean currents. The lesson we propose aims to familiarize students with the manifestation of the Coriolis effect. Students are guided to build, using the GeoGebra software, a simulation of the motion of a body, related to a rotating reference system. The mathematical expression of the Coriolis force is deduced, for particular cases, and the Foucault's pendulum is presented and explained. Students have the opportunity to deepen the subject, by developing materials related to topics such as: • Global Wind Pattern • Ocean Currents • Coriolis Effect in Long Range Shooting • Finding the latitude with a Foucault Pendulum

  2. Invisible force

    International Nuclear Information System (INIS)

    Panek, Richard

    2010-01-01

    Astronomers have compiled evidence that what we always thought of as the actual universe- all the planets, stars, galaxies and matter in space -represents a mere 4% of what's out there. The rest is dark: 23% is called dark matter, 73% dark energy. Scientists have ideas about what dark matter is, but hardly any understanding about dark energy. This has led to rethinking traditional physics and cosmology. Assuming the existence of dark matter and that the law of gravitation is universal, two teams of astrophysicists, from Lawrence Berkeley National Laboratory and the Australian National University, analysed the universe's growth and to their surprise both concluded that the universe expansion is not slowing but speeding up. If the dominant force of evolution isn't gravity what is it?

  3. Running coupling from gluon and ghost propagators in the Landau gauge: Yang-Mills theories with adjoint fermions

    Science.gov (United States)

    Bergner, Georg; Piemonte, Stefano

    2018-04-01

    Non-Abelian gauge theories with fermions transforming in the adjoint representation of the gauge group (AdjQCD) are a fundamental ingredient of many models that describe the physics beyond the Standard Model. Two relevant examples are N =1 supersymmetric Yang-Mills (SYM) theory and minimal walking technicolor, which are gauge theories coupled to one adjoint Majorana and two adjoint Dirac fermions, respectively. While confinement is a property of N =1 SYM, minimal walking technicolor is expected to be infrared conformal. We study the propagators of ghost and gluon fields in the Landau gauge to compute the running coupling in the MiniMom scheme. We analyze several different ensembles of lattice Monte Carlo simulations for the SU(2) adjoint QCD with Nf=1 /2 ,1 ,3 /2 , and 2 Dirac fermions. We show how the running of the coupling changes as the number of interacting fermions is increased towards the conformal window.

  4. Study of distributed fiber-optic laser-ultrasound generation based on ghost-mode of tilted fiber Bragg gratings

    Science.gov (United States)

    Tian, Jiajun; Zhang, Qi; Han, Ming

    2013-05-01

    Fiber-optic ultrasonic transducers are an important component of an active ultrasonic testing system for structural health monitoring. Fiber-optic transducers have several advantages such as small size, light weight, and immunity to electromagnetic interference that make them much more attractive than the current available piezoelectric transducers, especially as embedded and permanent transducers in active ultrasonic testing for structural health monitoring. In this paper, a distributed fiber-optic laser-ultrasound generation based on the ghost-mode of tilted fiber Bragg gratings is studied. The influences of the laser power and laser pulse duration on the laser-ultrasound generation are investigated. The results of this paper are helpful to understand the working principle of this laser-ultrasound method and improve the ultrasonic generation efficiency.

  5. A new ghost-node method for linking different models and initial investigations of heterogeneity and nonmatching grids

    Science.gov (United States)

    Dickinson, J.E.; James, S.C.; Mehl, S.; Hill, M.C.; Leake, S.A.; Zyvoloski, G.A.; Faunt, C.C.; Eddebbarh, A.-A.

    2007-01-01

    A flexible, robust method for linking parent (regional-scale) and child (local-scale) grids of locally refined models that use different numerical methods is developed based on a new, iterative ghost-node method. Tests are presented for two-dimensional and three-dimensional pumped systems that are homogeneous or that have simple heterogeneity. The parent and child grids are simulated using the block-centered finite-difference MODFLOW and control-volume finite-element FEHM models, respectively. The models are solved iteratively through head-dependent (child model) and specified-flow (parent model) boundary conditions. Boundary conditions for models with nonmatching grids or zones of different hydraulic conductivity are derived and tested against heads and flows from analytical or globally-refined models. Results indicate that for homogeneous two- and three-dimensional models with matched grids (integer number of child cells per parent cell), the new method is nearly as accurate as the coupling of two MODFLOW models using the shared-node method and, surprisingly, errors are slightly lower for nonmatching grids (noninteger number of child cells per parent cell). For heterogeneous three-dimensional systems, this paper compares two methods for each of the two sets of boundary conditions: external heads at head-dependent boundary conditions for the child model are calculated using bilinear interpolation or a Darcy-weighted interpolation; specified-flow boundary conditions for the parent model are calculated using model-grid or hydrogeologic-unit hydraulic conductivities. Results suggest that significantly more accurate heads and flows are produced when both Darcy-weighted interpolation and hydrogeologic-unit hydraulic conductivities are used, while the other methods produce larger errors at the boundary between the regional and local models. The tests suggest that, if posed correctly, the ghost-node method performs well. Additional testing is needed for highly

  6. Equilibrium thermodynamics of the partitioning of non-steroidal anti-inflammatory drugs into human erythrocyte ghost membranes

    International Nuclear Information System (INIS)

    Omran, Ahmed A.

    2013-01-01

    Graphical abstract: Bar diagram representing thermodynamic parameters obtained for the partitioning of NSAIDs into human erythrocyte ghost membranes at physiological pH; 7.4. Highlights: • Partition coefficients of NSAIDs into HEG membranes were determined. • Thermodynamic parameters were evaluated and successfully analyzed. • Partitioning of NSAIDs into HEG membranes was exothermic. • Partitioning of NSAIDs into HEG is spontaneous with negative free energy values. • Identical partitioning enthalpy–entropy driven compensation mechanism was shown. -- Abstract: In this work,second derivative spectrophotometry was applied for determining the partition coefficients (K p s) of four non-steroidal anti-inflammatory drugs (NSAIDs; flufenamic, meclofenamic, mefenamic and niflumic acids) into human erythrocyte ghost (HEG) membranes over a temperature range from (283.2 to 313.2) K. The proposed method allowed the evaluation and direct analyses of thermodynamic parameters; enthalpy (ΔH W→M ), Gibbs energy (ΔG W→M ) and entropy (ΔS W→M ) changes of the partitioning of NSAIDs into HEG membranes. The partitioning of NSAIDs between polar aqueous phase and non-polar lipid bilayer HEG membrane phase was exothermic with negative (ΔH W→M ) which compensated for the changes in (ΔS W→M ). The negative values of (ΔG W→M ) revealed that the partitioning of NSAIDs into HEG, owing to their transfer from polar aqueous phase and non-polar HEG phase is spontaneous. The enthalpy–entropy correlation analysis resulted in a good linearity that suggests an identical partitioning enthalpy–entropy driven compensation mechanism for the studied NSAIDs

  7. Chasing ghosts: allopolyploid origin of Oxyria sinensis (Polygonaceae) from its only diploid congener and an unknown ancestor.

    Science.gov (United States)

    Luo, Xin; Hu, Quanjun; Zhou, Pingping; Zhang, Dan; Wang, Qian; Abbott, Richard J; Liu, Jianquan

    2017-06-01

    Reconstructing the origin of a polyploid species is particularly challenging when an ancestor has become extinct. Under such circumstances, the extinct donor of a genome found in the polyploid may be treated as a 'ghost' species in that its prior existence is recognized through the presence of its genome in the polyploid. In this study, we aimed to determine the polyploid origin of Oxyria sinensis (2n = 40) for which only one congeneric species is known, that is diploid O. digyna (2n = 14). Genomic in situ hybridization (GISH), transcriptome, phylogenetic and demographic analyses, and ecological niche modelling were conducted for this purpose. GISH revealed that O. sinensis comprised 14 chromosomes from O. digyna and 26 chromosomes from an unknown ancestor. Transcriptome analysis indicated that following divergence from O. digyna, involving genome duplication around 12 million years ago (Ma), a second genome duplication occurred approximately 6 Ma to give rise to O. sinensis. Oxyria sinensis was shown to contain homologous gene sequences divergent from those present in O. digyna in addition to a set that clustered with those in O. digyna. Coalescent simulations indicated that O. sinensis expanded its distribution approximately 6-7 Ma, possibly following the second polyploidization event, whereas O. digyna expanded its range much later. It was also indicated that the distributions of both species contracted and re-expanded during the Pleistocene climatic oscillations. Ecological niche modelling similarly suggested that both species experienced changes in their distributional ranges in response to Quaternary climatic changes. The extinction of the unknown 'ghost' tetraploid species implicated in the origin of O. sinensis could have resulted from superior adaptation of O. sinensis to repeated climatic changes in the region where it now occurs. © 2017 John Wiley & Sons Ltd.

  8. The Prevalence of Honorary and Ghost Authorships in Iranian Bio-Medical Journals and Its Associated Factors

    Science.gov (United States)

    Mirzazadeh, A; Navadeh, S; Rokni, MB; Farhangniya, M

    2011-01-01

    Background: The purpose of this study was to detect the prevalence of ghost and honorary authors and its determinant factors in bio-medical journals of Iran. Methods: The study was done in 2009–10 in Tehran, Kerman, and Iran Medical Universities, Iran. We contacted the first or corresponding authors of the papers had published papers in the recent two issues of Iranian Journal of Public Health, Journal of Kerman University of Medical Sciences, and Tehran University Medical Journal. They explored the role of each coauthor and others who had done mouthing for the paper. Then, according to ICMJE criteria, we counted how many of them are real, honorary or ghost author. For the analysis, we utilized two databases. One included articles as the records and the other included authors as the records. Results: From 124 articles, with 536 authors, 301 (56.1%) were honorary authors. Each article had 4.35 authors on average, while 2.4 of them were honorary authors. The percentage of honorary author in basic science articles was about 6% more than the articles of clinical sciences. Moreover, 89% of articles had at least one honorary author. About 20% of all articles had more than three honorary authors. Besides, 25 (21.43%) authors confessed they had colleague(s) omitted from the authors list, while only one (0.81%) of them met the authorship criteria. The percentage of agreement between the corresponding and the remaining authors on the number of honorary of the authors was about 47.4% (Kappa= 0.27, P= 0.01). Conclusion: It seems that the present data might assist the authorities to make a decisive decision on amending the process of authorship in Iran. PMID:23113050

  9. Operations Charioteer, Musketeer, Touchstone, Cornerstone, Aqueduct, Sculpin and Julin. Tests Mill Yard, Diamond Beech, Mighty Oak, Middle Note Mission Ghost, Mission Cyber, Misty Echo, Disko Elm, Mineral Quarry, Distant Zenith, Diamond Fortune, and Hunters Trophy

    National Research Council Canada - National Science Library

    Schoengold, Carole

    1999-01-01

    ...; Tests MILL YARD, DIAMOND BEECH, MIGHTY OAK, MIDDLE NOTE, MISSION GHOST, MISSION CYBER, MISTY ECHO, DISKO ELM, MINERAL QUARRY, DISTANT ZENITH, DIAMOND FORTUNE, and HUNTERS TROPHY, 9 October 1985 to 18 September 1992...

  10. An Energy-Based State Observer for Dynamical Subsystems with Inaccessible State Variables

    NARCIS (Netherlands)

    Khalil, I.S.M.; Sabanovic, Asif; Misra, Sarthak

    2012-01-01

    This work presents an energy-based state estimation formalism for a class of dynamical systems with inaccessible/unknown outputs, and systems at which sensor utilization is impractical, or when measurements can not be taken. The power-conserving physical interconnections among most of the dynamical

  11. A unifying energy-based approach to stability of power grids with market dynamics

    NARCIS (Netherlands)

    Stegink, Tjerk; De Persis, Claudio; van der Schaft, Arjan

    2017-01-01

    In this paper a unifying energy-based approach is provided to the modeling and stability analysis of power systems coupled with market dynamics. We consider a standard model of the power network with a third-order model for the synchronous generators involving voltage dynamics. By applying the

  12. More on ghost condensation in Yang-Mills theory: BCS versus Overhauser effect and the breakdown of the Nakanishi-Ojima annex SL(2,R) symmetry

    International Nuclear Information System (INIS)

    Dudal, David; Verschelde, Henri; Lemes, Vitor E.R.; Sarandy, Marcelo S.; Sorella, Silvio P.; Picariello, Marco; Vicini, Alessandro; Gracey, John A.

    2003-01-01

    We analyze the ghost condensates abc c b c c >, abc c-bar b c-bar c > and abc c-barbc c > in Yang-Mills theory in the Curci-Ferrari gauge. By combining the local composite operator formalism with the algebraic renormalization technique, we are able to give a simultaneous discussion of abc c b c c >, abc c-bar b c-bar c > and abc c-bar b c c >, which can be seen as playing the role of the BCS, respectively Overhauser effect in ordinary superconductivity. The Curci-Ferrari gauge exhibits a global continuous symmetry generated by the Nakanishi-Ojima (NO) algebra. This algebra includes, next to the {(anti-)BRST} transformation, a SL(2,R) subalgebra. We discuss the dynamical symmetry breaking of the NO algebra through these ghost condensates. Particular attention is paid to the Landau gauge, a special case of the Curci-Ferrari gauge. (author)

  13. The Cosmic Christmas Ghost - Two Stunning Pictures of Young Stellar Clusters

    Science.gov (United States)

    2005-12-01

    Just like Charles Dickens' Christmas Carol takes us on a journey into past, present and future in the time of only one Christmas Eve, two of ESO' s telescopes captured various stages in the life of a star in a single image. ESO PR Photo 42a/05 shows the area surrounding the stellar cluster NGC 2467, located in the southern constellation of Puppis (" The Stern" ). With an age of a few million years at most, it is a very active stellar nursery, where new stars are born continuously from large clouds of dust and gas. The image, looking like a colourful cosmic ghost or a gigantic celestial Mandrill [1] , contains the open clusters Haffner 18 (centre) and Haffner 19 (middle right: it is located inside the smaller pink region - the lower eye of the Mandrill), as well as vast areas of ionised gas. The bright star at the centre of the largest pink region on the bottom of the image is HD 64315, a massive young star that is helping shaping the structure of the whole nebular region. ESO PR Photo 42a/05 was taken with the Wide-Field Imager camera at the 2.2m MPG/ESO telescope located at La Silla, in Chile. Another image of the central part of this area is shown as ESO PR Photo 42b/05. It was obtained with the FORS2 instrument at ESO' s Very Large Telescope on Cerro Paranal, also in Chile. ESO PR Photo 42b/05 zooms in on the open stellar cluster Haffner 18, perfectly illustrating three different stages of this process of star formation: In the centre of the picture, Haffner 18, a group of mature stars that have already dispersed their birth nebulae, represents the completed product or immediate past of the star formation process. Located at the bottom left of this cluster, a very young star, just come into existence and, still surrounded by its birth cocoon of gas, provides insight into the very present of star birth. Finally, the dust clouds towards the right corner of the image are active stellar nurseries that will produce more new stars in the future. Haffner 18 contains

  14. 12th Air Force > Home

    Science.gov (United States)

    Force AOR Travel Info News prevnext Slide show 76,410 pounds of food delivered to Haiti 12th Air Force the French Air Force, Colombian Air Force, Pakistan Air Force, Belgian Air Force, Brazilian Air Force

  15. Illusion and Disillusionment in the Name of the “Ghost”:A Study of Xu Xu’s “Ghost Love”

    OpenAIRE

    Qin, Chen

    2017-01-01

    As one of the most popular writers of the Republican period, Xu Xu (1908-1980) is famous for fiction characterized by a cosmopolitan atmosphere, exoticism, and fantastic encounters. Ghost Love, his first well-known work, presents the traditional narrative of “a man encountering a female ghost” and offers serious contemplation about the nature of reality from the perspective of psychology, philosophy, and politics. In examining the intertextualit...

  16. PERFORMANCE ANALYSIS OF DSR ROUTING PROTOCOL UNDER ENERGY BASED SELFISH ATTACK IN MOBILE AD HOC NETWORKS

    Directory of Open Access Journals (Sweden)

    T.V.P.Sundararajan

    2010-06-01

    Full Text Available Mobile Ad hoc Networks (MANETs rely on the cooperation of all participating nodes to provide the fundamental operations such as routing and data forwarding. However, due to the open structure and scarcely available battery-based energy, node misbehaviors may exist.[1]. One such routing misbehavior is that some selfish nodes will participate in the route discovery and maintenance processes but refuse to forward data packets. This paper pointed out Energy based selfish nodes (EBSN where these selfish nodes tend to use the network but do not cooperate, saving battery life for their own communications [2],[3]. We present a simulation study of the effects of Energy based selfish nodes (EBSN on DSR routing protocol and its impact over network performance in terms of throughput and delay of a mobile ad hoc network where a defined percentage of nodes were misbehaving.

  17. Full Waveform Inversion Using an Energy-Based Objective Function with Efficient Calculation of the Gradient

    KAUST Repository

    Choi, Yun Seok

    2017-05-26

    Full waveform inversion (FWI) using an energy-based objective function has the potential to provide long wavelength model information even without low frequency in the data. However, without the back-propagation method (adjoint-state method), its implementation is impractical for the model size of general seismic survey. We derive the gradient of the energy-based objective function using the back-propagation method to make its FWI feasible. We also raise the energy signal to the power of a small positive number to properly handle the energy signal imbalance as a function of offset. Examples demonstrate that the proposed FWI algorithm provides a convergent long wavelength structure model even without low-frequency information, which can be used as a good starting model for the subsequent conventional FWI.

  18. Sulfur and iron accumulation in three marine-archaeological shipwrecks in the Baltic Sea: The Ghost, the Crown and the Sword

    Science.gov (United States)

    Fors, Yvonne; Grudd, Håkan; Rindby, Anders; Jalilehvand, Farideh; Sandström, Magnus; Cato, Ingemar; Bornmalm, Lennart

    2014-02-01

    Sulfur and iron concentrations in wood from three 17th century shipwrecks in the Baltic Sea, the Ghost wreck, the Crown and the Sword, were obtained by X-ray fluorescence (XRF) scanning. In near anaerobic environments symbiotic microorganisms degrade waterlogged wood, reduce sulfate and promote accumulation of low-valent sulfur compounds, as previously found for the famous wrecks of the Vasa and Mary Rose. Sulfur K-edge X-ray absorption near-edge structure (XANES) analyses of Ghost wreck wood show that organic thiols and disulfides dominate, together with elemental sulfur probably generated by sulfur-oxidizing Beggiatoa bacteria. Iron sulfides were not detected, consistent with the relatively low iron concentration in the wood. In a museum climate with high atmospheric humidity oxidation processes, especially of iron sulfides formed in the presence of corroding iron, may induce post-conservation wood degradation. Subject to more general confirmation by further analyses no severe conservation concerns are expected for the Ghost wreck wood.

  19. Dynamical equations for a Regge theory with crossing symmetry and unitarity. II. The case of strong coupling, and elimination of ghost poles

    International Nuclear Information System (INIS)

    Johnson, P.W.; Warnock, R.L.

    1977-01-01

    Equations for the construction of a crossing-symmetric unitary Regge theory of meson-meson scattering are described. In the case of strong coupling, Regge trajectories are to be generated dynamically as zeros of the D function in a nonlinear N/D system. This paper is concerned mainly with writing the inputs to the N/D system in such a way that a convergent theory with exact crossing symmetry is defined. The scheme demands elimination of ghosts, i.e., bound-state poles at energies below threshold where trajectories pass through zero. A method for ghost elimination is proposed which entails an s-wave subtraction constant, and allows the physical s wave to be different from the l-analytic amplitude evaluated at l = 0. A dynamical model is suggested in which the subtraction constant alone generates the meson-meson interaction. An alternative ghost-elimination scheme proposed by Gell-Mann, in which only l-analytic amplitudes are involved, can be discussed in a formalism including channels with spin

  20. Techno-economic studies on hybrid energy based cooling system for milk preservation in isolated regions

    International Nuclear Information System (INIS)

    Edwin, M.; Joseph Sekhar, S.

    2014-01-01

    Highlights: • Performance studies on biomass and biogas based milk cooling systems in remote areas. • Economic analysis of milk cooling system operated with locally available renewable energy sources. • Payback period for replacing conventional milk cooling systems with renewable energy based cooling system. • Identification of the suitable combination of locally available renewable energy sources for milk cooling. • Hybrid energy based milk cooling system for regions that have rubber and paddy cultivation, in India. - Abstract: In developing countries like India, about 70% of the population is engaged in the production of milk, fruits and vegetables. Due to the lack of proper storage and transit facilities, the agricultural produce, in remote areas loses its value. This spoilage could be prevented at the local village level, by providing cooling units for short term preservation. In this paper, the possibility of a hybrid energy based thermally operated cold storage has been considered to meet the cooling needs of the villages in the southern parts of India, where biomass, biogas and gobar gas are available in abundance. A milk cooling system that uses various combinations of locally available renewable energy sources to operate an aqua ammonia vapour absorption cooling system has been analysed using the Matlab software. The impact of various combinations of renewable energy sources on the Coefficient of Performance (COP), Net Present Value (NPV) and payback period of the total cooling system has been studied. The analysis shows that the COP and payback period of the proposed hybrid renewable energy based milk cooling system are 0.16–0.23 and 4–6 years respectively

  1. Handbook of force transducers

    CERN Document Server

    Stefanescu, Dan Mihai

    2011-01-01

    Part I introduces the basic ""Principles and Methods of Force Measurement"" acording to a classification into a dozen of force transducers types: resistive, inductive, capacitive, piezoelectric, electromagnetic, electrodynamic, magnetoelastic, galvanomagnetic (Hall-effect), vibrating wires, (micro)resonators, acoustic and gyroscopic. Two special chapters refer to force balance techniques and to combined methods in force measurement. Part II discusses the ""(Strain Gauge) Force Transducers Components"", evolving from the classical force transducer to the digital / intelligent one, with the inco

  2. A Unitary and Renormalizable Theory of the Standard Model in Ghost-Free Light-Cone Gauge

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, Stanley J.

    2002-02-15

    Light-front (LF) quantization in light-cone (LC) gauge is used to construct a unitary and simultaneously renormalizable theory of the Standard Model. The framework derived earlier for QCD is extended to the Glashow, Weinberg, and Salam (GWS) model of electroweak interaction theory. The Lorentz condition is automatically satisfied in LF-quantized QCD in the LC gauge for the free massless gauge field. In the GWS model, with the spontaneous symmetry breaking present, we find that the 't Hooft condition accompanies the LC gauge condition corresponding to the massive vector boson. The two transverse polarization vectors for the massive vector boson may be chosen to be the same as found in QCD. The non-transverse and linearly independent third polarization vector is found to be parallel to the gauge direction. The corresponding sum over polarizations in the Standard model, indicated by K{sub {mu}{nu}}(k); has several simplifying properties similar to the polarization sum D{sub {mu}{nu}}(k) in QCD. The framework is ghost-free, and the interaction Hamiltonian of electroweak theory can be expressed in a form resembling that of covariant theory, except for few additional instantaneous interactions which can be treated systematically. The LF formulation also provides a transparent discussion of the Goldstone Boson (or Electroweak) Equivalence Theorem, as the illustrations show.

  3. ResearchGate is no longer reliable: leniency towards ghost journals may decrease its impact on the scientific community.

    Science.gov (United States)

    Memon, Aamir Raoof

    2016-12-01

    ResearchGate has been regarded as one of the most attractive academic social networking site for scientific community. It has been trying to improve user-centered interfaces to gain more attractiveness to scientists around the world. Display of journal related scietometric measures (such as impact factor, 5-year impact, cited half-life, eigenfactor) is an important feature in ResearchGate. Open access publishing has added more to increased visibility of research work and easy access to information related to research. Moreover, scientific community has been much interested in promoting their work and exhibiting its impact to others through reliable scientometric measures. However, with the growing market of publications and improvements in the field of research, this community has been victimized by the cybercrime in the form of ghost journals, fake publishers and magical impact measures. Particularly, ResearchGate more recently, has been lenient in its policies against this dark side of academic writing. Therefore, this communication aims to discuss concerns associated with leniency in ResearchGate policies and its impact of scientific community.

  4. Invariant gauge families inherent in Abelian-gauge field theory. [Scalar dipole ghost field, free-field equations

    Energy Technology Data Exchange (ETDEWEB)

    Yokoyama, Kan-ichi; Kubo, Reijiro

    1974-12-01

    The framework of the Nakanishi-Lautrup formalism should be enlarged by introducing a scalar dipole ghost field B(x), which is called gauge on field, together with its pair field. By taking free Lagrangian density, Free-field equations can be described. The vacuum is defined by using a neutral vector field U..mu..(x). The state-vector space is generated by the adjoining conjugates of U..mu..sup((+))(x), and auxiliary fields B(x), B/sub 1/(x) and B/sub 2/(x), which were introduced in the form of the Lagrangian density. The physical states can be defined by the supplementary conditions of the form B/sub 1/sup((+))(x) 1 phys>=B/sub 2/sup((+))(x) 1 phys>=0. It is seen that all the field equations and all the commutators are kept form-invariant, and that the gauge parameter ..cap alpha.. is transformed into ..cap alpha..' given by ..cap alpha..'=..cap alpha..+lambda, with epsilon unchanged. The Lagrangian density is specified only by the gauge invariant parameter epsilon. The gauge structure of theory has universal meaning over whole Abelian-gauge field. C-number gauge transformation and the gauge structure in the presence of interaction are also discussed.

  5. Multi-parameter flow cytometry as a process analytical technology (PAT) approach for the assessment of bacterial ghost production.

    Science.gov (United States)

    Langemann, Timo; Mayr, Ulrike Beate; Meitz, Andrea; Lubitz, Werner; Herwig, Christoph

    2016-01-01

    Flow cytometry (FCM) is a tool for the analysis of single-cell properties in a cell suspension. In this contribution, we present an improved FCM method for the assessment of E-lysis in Enterobacteriaceae. The result of the E-lysis process is empty bacterial envelopes-called bacterial ghosts (BGs)-that constitute potential products in the pharmaceutical field. BGs have reduced light scattering properties when compared with intact cells. In combination with viability information obtained from staining samples with the membrane potential-sensitive fluorescent dye bis-(1,3-dibutylarbituric acid) trimethine oxonol (DiBAC4(3)), the presented method allows to differentiate between populations of viable cells, dead cells, and BGs. Using a second fluorescent dye RH414 as a membrane marker, non-cellular background was excluded from the data which greatly improved the quality of the results. Using true volumetric absolute counting, the FCM data correlated well with cell count data obtained from colony-forming units (CFU) for viable populations. Applicability of the method to several Enterobacteriaceae (different Escherichia coli strains, Salmonella typhimurium, Shigella flexneri 2a) could be shown. The method was validated as a resilient process analytical technology (PAT) tool for the assessment of E-lysis and for particle counting during 20-l batch processes for the production of Escherichia coli Nissle 1917 BGs.

  6. Anomie and Isolation: The Wind-up Bird Chronicle, Ghost in the Shell, Serial Experiments Lain, and Japanese Consensus Society

    Directory of Open Access Journals (Sweden)

    Elmo Gonzaga

    2002-06-01

    Full Text Available The essay explores how the societal effects of Japan’s economic recession during the 1990s are reflected in several cultural texts from that period: Haruki Murakami’s novel The Wind-up Bird Chronicle, the animé film Ghost in the Shell and the animé series Serial Experiments Lain.Faced with sudden job uncertainty due to the recession, Japanese individuals accustomed to the ideology of progress of a society that values uniformity and conformity have fallen into listlessness and withdrawal. Accordingly, the protagonists of these texts all experience a crisis of embodied subjectivity, or shutaisei that is tied to a loss of community and history.They work to reconstitute their shutaisei by first uncovering their personal and collective history in the form of a coherent awareness of their past. Transcending their isolation, they likewise strive to develop bonds with others through reciprocal communication.Particularly because these texts are characterized by elements of the fantastic and narratives of metamorphosis, they can also be seen as allegories of subversion against Japanese consensus society and its ideology of progress.

  7. Combining extrapolation with ghost interaction correction in range-separated ensemble density functional theory for excited states

    Science.gov (United States)

    Alam, Md. Mehboob; Deur, Killian; Knecht, Stefan; Fromager, Emmanuel

    2017-11-01

    The extrapolation technique of Savin [J. Chem. Phys. 140, 18A509 (2014)], which was initially applied to range-separated ground-state-density-functional Hamiltonians, is adapted in this work to ghost-interaction-corrected (GIC) range-separated ensemble density-functional theory (eDFT) for excited states. While standard extrapolations rely on energies that decay as μ-2 in the large range-separation-parameter μ limit, we show analytically that (approximate) range-separated GIC ensemble energies converge more rapidly (as μ-3) towards their pure wavefunction theory values (μ → +∞ limit), thus requiring a different extrapolation correction. The purpose of such a correction is to further improve on the convergence and, consequently, to obtain more accurate excitation energies for a finite (and, in practice, relatively small) μ value. As a proof of concept, we apply the extrapolation method to He and small molecular systems (viz., H2, HeH+, and LiH), thus considering different types of excitations such as Rydberg, charge transfer, and double excitations. Potential energy profiles of the first three and four singlet Σ+ excitation energies in HeH+ and H2, respectively, are studied with a particular focus on avoided crossings for the latter. Finally, the extraction of individual state energies from the ensemble energy is discussed in the context of range-separated eDFT, as a perspective.

  8. BURROW ARCHITECTURE OF RED GHOST CRAB OCYPODE MACROCERA (H. MILNE-EDWARDS, 1852 : A CASE STUDY IN INDIAN SUNDARBANS

    Directory of Open Access Journals (Sweden)

    Sourabh Kumar Dubey

    2013-12-01

    Full Text Available A study on burrow architecture and burrow morphology of the red ghost crab (Ocypode macrocera was carried out at the southern proximity of the Sagar island (21°37.973' N, to E 88° 04.195', western sector of Indian Sundarbans that faces the regular tidal influences of Bay of Bengal. Ocypode macrocera constructs burrows that are highly species specific and used by single individual. Four types of burrow patterns were observed like ‘I’, ‘J’ ‘U’ and ‘semi-U’ type with different sizes as revealed by POP casting. Important physic-chemical parameters like air temperature, temperature and salinity of the water were significantly varied (P < 0.05 throughout seasons in the Ocypode zone. Burrow sand column temperature were also significantly varied from ambient air temperature thus exhibiting preference for cooler subterranean residential compartment. The digging behaviour of Ocypodes enhances oxygenation in the ground soil and facilitates decomposition of organic materials, nutrient recycling, entrapping the sediments and mangrove seedlings and helps the process of bioturbation. As per the preliminary observations it was suggested that burrow shape is directly related to tidal action and metabolic activities of the crab are strongly correlated with burrow microenvironment. They are adapted to the different sediment conditions, tidal fluctuations, varying salinity gradients, air and water temperatures and other environmental fluctuations.

  9. Shock wave-bubble interaction near soft and rigid boundaries during lithotripsy: numerical analysis by the improved ghost fluid method

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Kazumichi [Division of Mechanical and Space Engineering, Faculty of Engineering, Hokkaido University, Kita 13, Nishi 8, Kita-ku, Sapporo, Hokkaido 060-8628 (Japan); Kodama, Tetsuya [Department of Biomedical Engineering, Graduate School of Biomedical Engineering, Tohoku University, 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8575 (Japan); Takahira, Hiroyuki, E-mail: kobakazu@eng.hokudai.ac.jp [Department of Mechanical Engineering, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai 599-8531 (Japan)

    2011-10-07

    In the case of extracorporeal shock wave lithotripsy (ESWL), a shock wave-bubble interaction inevitably occurs near the focusing point of stones, resulting in stone fragmentation and subsequent tissue damage. Because shock wave-bubble interactions are high-speed phenomena occurring in tissue consisting of various media with different acoustic impedance values, numerical analysis is an effective method for elucidating the mechanism of these interactions. However, the mechanism has not been examined in detail because, at present, numerical simulations capable of incorporating the acoustic impedance of various tissues do not exist. Here, we show that the improved ghost fluid method (IGFM) can treat shock wave-bubble interactions in various media. Nonspherical bubble collapse near a rigid or soft tissue boundary (stone, liver, gelatin and fat) was analyzed. The reflection wave of an incident shock wave at a tissue boundary was the primary cause for the acceleration or deceleration of bubble collapse. The impulse that was obtained from the temporal evolution of pressure created by the bubble collapse increased the downward velocity of the boundary and caused subsequent boundary deformation. Results of this study showed that the IGFM is a useful method for analyzing the shock wave-bubble interaction near various tissues with different acoustic impedance.

  10. Shock wave-bubble interaction near soft and rigid boundaries during lithotripsy: numerical analysis by the improved ghost fluid method

    International Nuclear Information System (INIS)

    Kobayashi, Kazumichi; Kodama, Tetsuya; Takahira, Hiroyuki

    2011-01-01

    In the case of extracorporeal shock wave lithotripsy (ESWL), a shock wave-bubble interaction inevitably occurs near the focusing point of stones, resulting in stone fragmentation and subsequent tissue damage. Because shock wave-bubble interactions are high-speed phenomena occurring in tissue consisting of various media with different acoustic impedance values, numerical analysis is an effective method for elucidating the mechanism of these interactions. However, the mechanism has not been examined in detail because, at present, numerical simulations capable of incorporating the acoustic impedance of various tissues do not exist. Here, we show that the improved ghost fluid method (IGFM) can treat shock wave-bubble interactions in various media. Nonspherical bubble collapse near a rigid or soft tissue boundary (stone, liver, gelatin and fat) was analyzed. The reflection wave of an incident shock wave at a tissue boundary was the primary cause for the acceleration or deceleration of bubble collapse. The impulse that was obtained from the temporal evolution of pressure created by the bubble collapse increased the downward velocity of the boundary and caused subsequent boundary deformation. Results of this study showed that the IGFM is a useful method for analyzing the shock wave-bubble interaction near various tissues with different acoustic impedance.

  11. Shock wave-bubble interaction near soft and rigid boundaries during lithotripsy: numerical analysis by the improved ghost fluid method

    Science.gov (United States)

    Kobayashi, Kazumichi; Kodama, Tetsuya; Takahira, Hiroyuki

    2011-10-01

    In the case of extracorporeal shock wave lithotripsy (ESWL), a shock wave-bubble interaction inevitably occurs near the focusing point of stones, resulting in stone fragmentation and subsequent tissue damage. Because shock wave-bubble interactions are high-speed phenomena occurring in tissue consisting of various media with different acoustic impedance values, numerical analysis is an effective method for elucidating the mechanism of these interactions. However, the mechanism has not been examined in detail because, at present, numerical simulations capable of incorporating the acoustic impedance of various tissues do not exist. Here, we show that the improved ghost fluid method (IGFM) can treat shock wave-bubble interactions in various media. Nonspherical bubble collapse near a rigid or soft tissue boundary (stone, liver, gelatin and fat) was analyzed. The reflection wave of an incident shock wave at a tissue boundary was the primary cause for the acceleration or deceleration of bubble collapse. The impulse that was obtained from the temporal evolution of pressure created by the bubble collapse increased the downward velocity of the boundary and caused subsequent boundary deformation. Results of this study showed that the IGFM is a useful method for analyzing the shock wave-bubble interaction near various tissues with different acoustic impedance.

  12. A new model for commercially sustainable renewable energy-based rural electrification in Indonesia

    Energy Technology Data Exchange (ETDEWEB)

    Walt, Robb [Integrated Power Corporation-Indonesia, (United states)

    1995-12-31

    Rapidly increasing demands and requirements for access to electricity throughout the remote areas of Indonesia coupled with annual subsidies in excess of $500 million of dollars for rural electrification have forced the Government of Indonesia to search for alternatives to the conventional utility model for rural electrification. In 1992-1993 a study was conducted in collaboration with the Government of Indonesia`s Agency Application and Assessment of Technology (BPPT) and the national power utility, PLN to support the search for sustainable solutions for electrification of remote communities. This study produced a New commercial model for electrification of off-grid rural communities in Indonesia with utility quality electricity services. This new model is characterized by the use of new technologies for power generation, distribution, and sales of electricity. Key to the success of the new model are renewable energy-based hybrid power plants and the use of flexible, on-demand electricity dispensing meters. Estimated fees for electricity service are based on the current amounts now being paid by rural households for kerosene, candles and battery services at different income levels. The study showed that most rural households are willing and able to pay additional amounts for reliable, utility grade electricity for valuable services, such as better lighting, TV entertainment and for productive (economic) uses during daytime hours. A financial assessment was conducted for investments in hybrid power systems for off-grid communities with revenues generated on the basis of market fees, and collected through new technology for electricity purchase and prepayment on a commodity basis. The assessment demonstrates that this approach would provide superior electricity services on a full-time basis, with little or no subsidy required during the three- to five-year commercialization phase, and with profitability as an achievable goal in the full commercial phase. [Espanol

  13. A new model for commercially sustainable renewable energy-based rural electrification in Indonesia

    Energy Technology Data Exchange (ETDEWEB)

    Walt, Robb [Integrated Power Corporation-Indonesia, (United states)

    1996-12-31

    Rapidly increasing demands and requirements for access to electricity throughout the remote areas of Indonesia coupled with annual subsidies in excess of $500 million of dollars for rural electrification have forced the Government of Indonesia to search for alternatives to the conventional utility model for rural electrification. In 1992-1993 a study was conducted in collaboration with the Government of Indonesia`s Agency Application and Assessment of Technology (BPPT) and the national power utility, PLN to support the search for sustainable solutions for electrification of remote communities. This study produced a New commercial model for electrification of off-grid rural communities in Indonesia with utility quality electricity services. This new model is characterized by the use of new technologies for power generation, distribution, and sales of electricity. Key to the success of the new model are renewable energy-based hybrid power plants and the use of flexible, on-demand electricity dispensing meters. Estimated fees for electricity service are based on the current amounts now being paid by rural households for kerosene, candles and battery services at different income levels. The study showed that most rural households are willing and able to pay additional amounts for reliable, utility grade electricity for valuable services, such as better lighting, TV entertainment and for productive (economic) uses during daytime hours. A financial assessment was conducted for investments in hybrid power systems for off-grid communities with revenues generated on the basis of market fees, and collected through new technology for electricity purchase and prepayment on a commodity basis. The assessment demonstrates that this approach would provide superior electricity services on a full-time basis, with little or no subsidy required during the three- to five-year commercialization phase, and with profitability as an achievable goal in the full commercial phase. [Espanol

  14. Energy-Based Tetrahedron Sensor for High-Temperature, High-Pressure Environments

    Science.gov (United States)

    Gee, Kent L.; Sommerfeldt, Scott D.; Blotter, Jonathan D.

    2012-01-01

    An acoustic energy-based probe has been developed that incorporates multiple acoustic sensing elements in order to obtain the acoustic pressure and three-dimensional acoustic particle velocity. With these quantities, the user can obtain various energy-based quantities, including acoustic energy density, acoustic intensity, and acoustic impedance. In this specific development, the probe has been designed to operate in an environment characterized by high temperatures and high pressures as is found in the close vicinity of rocket plumes. Given these capabilities, the probe is designed to be used to investigate the acoustic conditions within the plume of a rocket engine or jet engine to facilitate greater understanding of the noise generation mechanisms in those plumes. The probe features sensors mounted inside a solid sphere. The associated electronics for the probe are contained within the sphere and the associated handle for the probe. More importantly, the design of the probe has desirable properties that reduce the bias errors associated with determining the acoustic pressure and velocity using finite sum and difference techniques. The diameter of the probe dictates the lower and upper operating frequencies for the probe, where accurate measurements can be acquired. The current probe design implements a sphere diameter of 1 in. (2.5 cm), which limits the upper operating frequency to about 4.5 kHz. The sensors are operational up to much higher frequencies, and could be used to acquire pressure data at higher frequencies, but the energy-based measurements are limited to that upper frequency. Larger or smaller spherical probes could be designed to go to lower or higher frequency range

  15. On the failure analysis of bondlines: Stress or energy based fracture criteria?

    DEFF Research Database (Denmark)

    Anyfantis, Konstantinos

    2014-01-01

    that characterizes a given bondline, both its cohesive strength and fracture toughness material parameters must be experimentally defined. Based on these properties, failure analysis of the bondline can be done either through stress- or energy-based criteria. The aim of this work is to investigate the effectiveness...... to classify the wide range of bondlines with respect to the failure theory that best describes the debonding process. Cohesive length scale effects are first demonstrated by modeling end notch flexure geometries and later by modeling double strap joint geometries within the framework of a wide numerical...

  16. Prediction of strain energy-based liquefaction resistance of sand-silt mixtures: An evolutionary approach

    Science.gov (United States)

    Baziar, Mohammad H.; Jafarian, Yaser; Shahnazari, Habib; Movahed, Vahid; Amin Tutunchian, Mohammad

    2011-11-01

    Liquefaction is a catastrophic type of ground failure, which usually occurs in loose saturated soil deposits under earthquake excitations. A new predictive model is presented in this study to estimate the amount of strain energy density, which is required for the liquefaction triggering of sand-silt mixtures. A wide-ranging database containing the results of cyclic tests on sand-silt mixtures was first gathered from previously published studies. Input variables of the model were chosen from the available understandings evolved from the previous studies on the strain energy-based liquefaction potential assessment. In order to avoid overtraining, two sets of validation data were employed and a particular monitoring was made on the behavior of the evolved models. Results of a comprehensive parametric study on the proposed model are in accord with the previously published experimental observations. Accordingly, the amount of strain energy required for liquefaction onset increases with increase in initial effective overburden pressure, relative density, and mean grain size. The effect of nonplastic fines on strain energy-based liquefaction resistance shows a more complicated behavior. Accordingly, liquefaction resistance increases with increase in fines up to about 10-15% and then starts to decline for a higher increase in fines content. Further verifications of the model were carried out using the valuable results of some downhole array data as well as centrifuge model tests. These verifications confirm that the proposed model, which was derived from laboratory data, can be successfully utilized under field conditions.

  17. Thermodynamic performance assessment of a novel environmentally-benign solar energy based integrated system

    International Nuclear Information System (INIS)

    Yuksel, Yunus Emre; Ozturk, Murat; Dincer, Ibrahim

    2016-01-01

    Highlights: • Development of a novel solar energy based system for multigenaration applications. • Evaluation of the exergy efficiency and destruction rate in each system component. • Investigation of the varying operating conditions on the system performance. • Evaluation of complete parametric studies and performance analysis of the system. - Abstract: In this paper, a novel solar energy based multigeneration system for producing electricity, hydrogen, hot water, heating and cooling is presented and analyzed thermodynamically for potential applications. The energy and exergy analyses are conducted for entire system and its sub-systems, which are a parabolic trough collector system, a double-stage organic Rankine cycle, a proton exchange membrane electrolyzer, a PEM fuel cycle and a quadruple effect absorption cooling system. The parametric studies are performed in order to indicate the impacts of some key indicators on the integrated system performance. These analyses are simulated by using the Engineering Equation Solver software. The results show that the increase in ambient temperature increases the exergetic coefficient performance of the Quadruple Effect Absorption Cooling System. In addition, the increase in solar intensity, temperature of absorber pipes inner surface and concentration of ammonia in working fluid mixture has the positive effect on produced electricity from the expanders and turbine, and hydrogen from the PEM electrolyzer. According to exergy analyses, the largest exergy destruction rates are obtained in the parabolic trough collector, PEM fuel cell and turbine. Therefore, any improvements in these components would lead to a better efficiency of the integrated system.

  18. Interfacial force measurements using atomic force microscopy

    NARCIS (Netherlands)

    Chu, L.

    2018-01-01

    Atomic Force Microscopy (AFM) can not only image the topography of surfaces at atomic resolution, but can also measure accurately the different interaction forces, like repulsive, adhesive and lateral existing between an AFM tip and the sample surface. Based on AFM, various extended techniques have

  19. Second order finite-difference ghost-point multigrid methods for elliptic problems with discontinuous coefficients on an arbitrary interface

    Science.gov (United States)

    Coco, Armando; Russo, Giovanni

    2018-05-01

    In this paper we propose a second-order accurate numerical method to solve elliptic problems with discontinuous coefficients (with general non-homogeneous jumps in the solution and its gradient) in 2D and 3D. The method consists of a finite-difference method on a Cartesian grid in which complex geometries (boundaries and interfaces) are embedded, and is second order accurate in the solution and the gradient itself. In order to avoid the drop in accuracy caused by the discontinuity of the coefficients across the interface, two numerical values are assigned on grid points that are close to the interface: a real value, that represents the numerical solution on that grid point, and a ghost value, that represents the numerical solution extrapolated from the other side of the interface, obtained by enforcing the assigned non-homogeneous jump conditions on the solution and its flux. The method is also extended to the case of matrix coefficient. The linear system arising from the discretization is solved by an efficient multigrid approach. Unlike the 1D case, grid points are not necessarily aligned with the normal derivative and therefore suitable stencils must be chosen to discretize interface conditions in order to achieve second order accuracy in the solution and its gradient. A proper treatment of the interface conditions will allow the multigrid to attain the optimal convergence factor, comparable with the one obtained by Local Fourier Analysis for rectangular domains. The method is robust enough to handle large jump in the coefficients: order of accuracy, monotonicity of the errors and good convergence factor are maintained by the scheme.

  20. Protection against Shiga-Toxigenic Escherichia coli by Non-Genetically Modified Organism Receptor Mimic Bacterial Ghosts.

    Science.gov (United States)

    Paton, Adrienne W; Chen, Austen Y; Wang, Hui; McAllister, Lauren J; Höggerl, Florian; Mayr, Ulrike Beate; Shewell, Lucy K; Jennings, Michael P; Morona, Renato; Lubitz, Werner; Paton, James C

    2015-09-01

    Shiga-toxigenic Escherichia coli (STEC) causes severe gastrointestinal infections in humans that may lead to life-threatening systemic sequelae, such as the hemolytic uremic syndrome (HUS). Rapid diagnosis of STEC infection early in the course of disease opens a window of opportunity for therapeutic intervention, for example, by administration of agents that neutralize Shiga toxin (Stx) in the gut lumen. We previously developed a recombinant bacterium that expresses a mimic of the Stx receptor globotriaosyl ceramide (Gb3) on its surface through modification of the lipopolysaccharide (A. W. Paton, R. Morona, and J. C. Paton, Nat Med 6:265-270, 2000, http://dx.doi.org/10.1038/73111). This construct was highly efficacious in vivo, protecting mice from otherwise fatal STEC disease, but the fact that it is a genetically modified organism (GMO) has been a barrier to clinical development. In the present study, we have overcome this issue by development of Gb3 receptor mimic bacterial ghosts (BGs) that are not classified as GMOs. Gb3-BGs neutralized Stx1 and Stx2 in vitro with high efficiency, whereas alternative Gb3-expressing non-GMO subbacterial particles (minicells and outer membrane blebs) were ineffective. Gb3-BGs were highly efficacious in a murine model of STEC disease. All mice (10/10) treated with Gb3-BGs survived challenge with a highly virulent O113:H21 STEC strain and showed no pathological signs of renal injury. In contrast, 6/10 mice treated with control BGs succumbed to STEC challenge, and survivors exhibited significant weight loss, neutrophilia, and histopathological evidence of renal damage. Thus, Gb3-BGs offer a non-GMO approach to treatment of STEC infection in humans, particularly in an outbreak setting. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  1. Ghost probiotics with a combined regimen: a novel therapeutic approach against the Zika virus, an emerging world threat.

    Science.gov (United States)

    Bajpai, Vivek K; Chandra, Vishal; Kim, Na-Hyung; Rai, Rajni; Kumar, Pradeep; Kim, Kangmin; Aeron, Abhinav; Kang, Sun Chul; Maheshwari, D K; Na, MinKyun; Rather, Irfan A; Park, Yong-Ha

    2018-05-01

    The Zika virus (ZIKV) used to be an obscure flavivirus closely related to dengue virus (DENV). Transmission of this epidemic pathogen occurs mainly via mosquitoes, but it is also capable of placental and sexual transmission. Although the characteristics of these viruses are well defined, infections are unpredictable in terms of disease severity, unusual clinical manifestations, unexpected methods of transmission, long-term persistence, and the development of new strains. Recently, ZIKV has gained huge medical attention following the large-scale epidemics around the world, and reported cases of congenital abnormalities associated with Zika virus infections which have created a public health emergency of international concern. Despite continuous research on ZIKV, no specific treatment or vaccine has been developed, excepting a preventive strategy for congenital ZIKV infection. Probiotics, known as GRAS, are bacteria that confer various health beneficial effects, and have been shown to be effective at curing a number of viral diseases by modulating the immune system. Furthermore, probiotic preparations consisting of dead cells and cellular metabolites, so-called "Ghost probiotics", can also act as biological response modifiers. Here, we review available information on the epidemiology, transmission, and clinical features of ZIKV, and on treatment and prevention strategies. In addition, we emphasize the use of probiotics and plant-based natural remedies and describe their action mechanisms, and the green technologies for microbial conversion, which could contribute to the development of novel therapies that may reduce the pathogenicity of ZIKV. Accordingly, we draw attention to new findings, unanswered questions, unresolved issues, and controversies regarding ZIKV.

  2. Multiple Authorship in Scientific Manuscripts: Ethical Challenges, Ghost and Guest/Gift Authorship, and the Cultural/Disciplinary Perspective.

    Science.gov (United States)

    Teixeira da Silva, Jaime A; Dobránszki, Judit

    2016-10-01

    Multiple authorship is the universal solution to multi-tasking in the sciences. Without a team, each with their own set of expertise, and each involved mostly in complementary ways, a research project will likely not advance quickly, or effectively. Consequently, there is a risk that research goals will not be met within a desired timeframe. Research teams that strictly scrutinize their modus operandi select and include a set of authors that have participated substantially in the physical undertaking of the research, in its planning, or who have contributed intellectually to the ideas or the development of the manuscript. Authorship is not an issue that is taken lightly, and save for dishonest authors, it is an issue that is decided collectively by the authors, usually in sync with codes of conduct established by their research institutes or national ministries of education. Science, technology and medicine (STM) publishers have, through independent, or sometimes coordinated efforts, also established their own sets of guidelines regarding what constitutes valid authorship. However, these are, for the greater part, merely guidelines. A previous and recent analysis of authorship definitions indicates that the definitions in place regarding authorship and its validity by many leading STM publishers is neither uniform, nor standard, despite several of them claiming to follow the guidelines as set forward by the International Committee of Medical Journal Editors or ICMJE. This disparity extends itself to ghost and guest authorship, two key authorship-related issues that are examined in this paper to assess the extent of discrepancies among the same set of STM publishers and what possible influence they might have on publishing ethics.

  3. El resurgir de viejos fantasmas: política asistencial y mundo del trabajo = The resurgence of old ghosts: social assistance policy and labor world

    Directory of Open Access Journals (Sweden)

    Ribero, Ximena Baráibar

    2015-01-01

    Full Text Available Since the end of the nineties, Latin America has widened and institutionalized its social assistance policies, mainly by the implementation of Conditional Cash Transfer Programs. In Uruguay, these programs have been implemented since 2005. One of the more debatable topics regarding these programs has been their impact on work and whether transfer programs would not incentive beneficiaries to work and promote their dependency with the State. This paper presents the Uruguayan case analyzing Conditional Cash Transfer Programs and the world of work stating there is no such impact of these programs on adult work. Rather, these concerns are old ghosts which have always been present in the social assistance arena

  4. Greenhouse Observations of the Stratosphere and Troposphere (GHOST): a novel shortwave infrared spectrometer developed for the Global Hawk unmanned aerial vehicle

    Science.gov (United States)

    Humpage, Neil; Boesch, Hartmut; Palmer, Paul; Parr-Burman, Phil; Vick, Andy; Bezawada, Naidu; Black, Martin; Born, Andy; Pearson, David; Strachan, Jonathan; Wells, Martyn

    2014-05-01

    The tropospheric distribution of greenhouse gases (GHGs) is dependent on surface flux variations, atmospheric chemistry and transport processes over a wide range of spatial and temporal scales. Errors in assumed atmospheric transport can adversely affect surface flux estimates inferred from surface, aircraft or satellite observations of greenhouse gas concentrations using inverse models. We present a novel, compact shortwave infrared spectrometer (GHOST) for installation on the NASA Global Hawk unmanned aerial vehicle to provide tropospheric column observations of CO2, CO, CH4, H2O and HDO over the ocean to address the need for large-scale, simultaneous, finely resolved measurements of key GHGs. These species cover a range of lifetimes and source processes, and measurements of their tropospheric columns will reflect the vertically integrated signal of their vertical and horizontal transport within the troposphere. The primary science objectives of GHOST are to: 1) provide observations which can be used to test atmospheric transport models; 2) validate satellite observations of GHG column observations over oceans, thus filling a critical gap in current validation capabilities; and 3) complement in-situ tropopause transition layer tracer observations from other instrumentation on board the Global Hawk to provide a link between upper and lower troposphere concentration measurements. The GHOST spectrometer system comprises a target acquisition module (TAM), a fibre slicer and feed system, and a multiple order spectrograph. The TAM design utilises a gimbal behind an optical dome, which is programmed to direct solar radiation reflected by the ocean surface into a fibre optic bundle. The fibre slicer and feed system then splits the light into the four spectral bands using order sorting filters. The fibres corresponding to each band are arranged with a small sideways offset to correctly centre each spectrum on the detector array. The spectrograph design is unique in that a

  5. Forces in general relativity

    International Nuclear Information System (INIS)

    Ridgely, Charles T

    2010-01-01

    Many textbooks dealing with general relativity do not demonstrate the derivation of forces in enough detail. The analyses presented herein demonstrate straightforward methods for computing forces by way of general relativity. Covariant divergence of the stress-energy-momentum tensor is used to derive a general expression of the force experienced by an observer in general coordinates. The general force is then applied to the local co-moving coordinate system of a uniformly accelerating observer, leading to an expression of the inertial force experienced by the observer. Next, applying the general force in Schwarzschild coordinates is shown to lead to familiar expressions of the gravitational force. As a more complex demonstration, the general force is applied to an observer in Boyer-Lindquist coordinates near a rotating, Kerr black hole. It is then shown that when the angular momentum of the black hole goes to zero, the force on the observer reduces to the force on an observer held stationary in Schwarzschild coordinates. As a final consideration, the force on an observer moving in rotating coordinates is derived. Expressing the force in terms of Christoffel symbols in rotating coordinates leads to familiar expressions of the centrifugal and Coriolis forces on the observer. It is envisioned that the techniques presented herein will be most useful to graduate level students, as well as those undergraduate students having experience with general relativity and tensor analysis.

  6. Proposed Empirical Entropy and Gibbs Energy Based on Observations of Scale Invariance in Open Nonequilibrium Systems.

    Science.gov (United States)

    Tuck, Adrian F

    2017-09-07

    There is no widely agreed definition of entropy, and consequently Gibbs energy, in open systems far from equilibrium. One recent approach has sought to formulate an entropy and Gibbs energy based on observed scale invariances in geophysical variables, particularly in atmospheric quantities, including the molecules constituting stratospheric chemistry. The Hamiltonian flux dynamics of energy in macroscopic open nonequilibrium systems maps to energy in equilibrium statistical thermodynamics, and corresponding equivalences of scale invariant variables with other relevant statistical mechanical variables such as entropy, Gibbs energy, and 1/(k Boltzmann T), are not just formally analogous but are also mappings. Three proof-of-concept representative examples from available adequate stratospheric chemistry observations-temperature, wind speed and ozone-are calculated, with the aim of applying these mappings and equivalences. Potential applications of the approach to scale invariant observations from the literature, involving scales from molecular through laboratory to astronomical, are considered. Theoretical support for the approach from the literature is discussed.

  7. Energy-based fatigue model for shape memory alloys including thermomechanical coupling

    Science.gov (United States)

    Zhang, Yahui; Zhu, Jihong; Moumni, Ziad; Van Herpen, Alain; Zhang, Weihong

    2016-03-01

    This paper is aimed at developing a low cycle fatigue criterion for pseudoelastic shape memory alloys to take into account thermomechanical coupling. To this end, fatigue tests are carried out at different loading rates under strain control at room temperature using NiTi wires. Temperature distribution on the specimen is measured using a high speed thermal camera. Specimens are tested to failure and fatigue lifetimes of specimens are measured. Test results show that the fatigue lifetime is greatly influenced by the loading rate: as the strain rate increases, the fatigue lifetime decreases. Furthermore, it is shown that the fatigue cracks initiate when the stored energy inside the material reaches a critical value. An energy-based fatigue criterion is thus proposed as a function of the irreversible hysteresis energy of the stabilized cycle and the loading rate. Fatigue life is calculated using the proposed model. The experimental and computational results compare well.

  8. Energy-based fatigue model for shape memory alloys including thermomechanical coupling

    International Nuclear Information System (INIS)

    Zhang, Yahui; Zhu, Jihong; Moumni, Ziad; Zhang, Weihong; Van Herpen, Alain

    2016-01-01

    This paper is aimed at developing a low cycle fatigue criterion for pseudoelastic shape memory alloys to take into account thermomechanical coupling. To this end, fatigue tests are carried out at different loading rates under strain control at room temperature using NiTi wires. Temperature distribution on the specimen is measured using a high speed thermal camera. Specimens are tested to failure and fatigue lifetimes of specimens are measured. Test results show that the fatigue lifetime is greatly influenced by the loading rate: as the strain rate increases, the fatigue lifetime decreases. Furthermore, it is shown that the fatigue cracks initiate when the stored energy inside the material reaches a critical value. An energy-based fatigue criterion is thus proposed as a function of the irreversible hysteresis energy of the stabilized cycle and the loading rate. Fatigue life is calculated using the proposed model. The experimental and computational results compare well. (paper)

  9. The calculation of surface free energy based on embedded atom method for solid nickel

    International Nuclear Information System (INIS)

    Luo Wenhua; Hu Wangyu; Su Kalin; Liu Fusheng

    2013-01-01

    Highlights: ► A new solution for accurate prediction of surface free energy based on embedded atom method was proposed. ► The temperature dependent anisotropic surface energy of solid nickel was obtained. ► In isotropic environment, the approach does not change most predictions of bulk material properties. - Abstract: Accurate prediction of surface free energy of crystalline metals is a challenging task. The theory calculations based on embedded atom method potentials often underestimate surface free energy of metals. With an analytical charge density correction to the argument of the embedding energy of embedded atom method, an approach to improve the prediction for surface free energy is presented. This approach is applied to calculate the temperature dependent anisotropic surface energy of bulk nickel and surface energies of nickel nanoparticles, and the obtained results are in good agreement with available experimental data.

  10. An Energy-Based Limit State Function for Estimation of Structural Reliability in Shock Environments

    Directory of Open Access Journals (Sweden)

    Michael A. Guthrie

    2013-01-01

    Full Text Available limit state function is developed for the estimation of structural reliability in shock environments. This limit state function uses peak modal strain energies to characterize environmental severity and modal strain energies at failure to characterize the structural capacity. The Hasofer-Lind reliability index is briefly reviewed and its computation for the energy-based limit state function is discussed. Applications to two degree of freedom mass-spring systems and to a simple finite element model are considered. For these examples, computation of the reliability index requires little effort beyond a modal analysis, but still accounts for relevant uncertainties in both the structure and environment. For both examples, the reliability index is observed to agree well with the results of Monte Carlo analysis. In situations where fast, qualitative comparison of several candidate designs is required, the reliability index based on the proposed limit state function provides an attractive metric which can be used to compare and control reliability.

  11. Renewable energy-based electricity for rural social and economic development in Ghana

    Energy Technology Data Exchange (ETDEWEB)

    Weingart, J.

    1997-12-01

    This paper describes a project whose goals include the establishment of a pilot renewable energy-based rural energy services enterprise to serve communities in the Mamprusi East District, focused on: economically productive activities; community services; household non-thermal energy. The program also seeks to establish the technical, economic, financial, institutional, and socio-cultural requirements for sustainability, to demonstrate bankability and financial sustainability, as a pre-investment prelude to commercial growth of such projects, and to establish technical, financial, and service performance standards for private sector rural energy service companies. This project is being implemented now because the government is undergoing structural reform, including privatization of the power sector, there is active foreign capital available for international development, and the government and people are committed to and able to pay for renewable energy services.

  12. Light and Energy Based Therapeutics for Genitourinary Syndrome of Menopause: Consensus and Controversies

    Science.gov (United States)

    Tadir, Yona; Gaspar, Adrian; Lev-Sagie, Ahinoam; Alexiades, Macrene; Alinsod, Red; Bader, Alex; Calligaro, Alberto; Elias, Jorge A.; Gambaciani, Marco; Gaviria, Jorge E.; Iglesia, Cheryl B.; Selih-Martinec, Ksenija; Mwesigwa, Patricia L.; Ogrinc, Urska B.; Salvatore, Stefano; Scollo, Paolo; Zerbinati, Nicola; Nelson, John Stuart

    2018-01-01

    Gynecologist and plastic surgeons pioneered the application of lasers in medicine and surgery almost 5 decades ago, initially used to treat cervical and vaginal pathologies. Ever since, energy-based devices have been deployed to treat pelvic pathologies and improve fertility. Recent technological developments triggered an unprecedented wave of publications, assessing the efficacy of fractional laser, and radiofrequency on the vaginal wall in reversing natural aging processes. Studies have shown that a certain degree of thermal energy deposited on the vaginal wall stimulates proliferation of the glycogen-enriched epithelium, neovascularization, and collagen formation in the lamina propria, and improves natural lubrication and control of urination. This review aimed to review such data and to guide future research. A unique assembly of experts from around the globe, compiled and edited this manuscript based on a thorough literature review and personal experience. Lasers Surg. Med. 49:137–159, 2017. PMID:28220946

  13. Detection of Human Impacts by an Adaptive Energy-Based Anisotropic Algorithm

    Directory of Open Access Journals (Sweden)

    Manuel Prado-Velasco

    2013-10-01

    Full Text Available Boosted by health consequences and the cost of falls in the elderly, this work develops and tests a novel algorithm and methodology to detect human impacts that will act as triggers of a two-layer fall monitor. The two main requirements demanded by socio-healthcare providers—unobtrusiveness and reliability—defined the objectives of the research. We have demonstrated that a very agile, adaptive, and energy-based anisotropic algorithm can provide 100% sensitivity and 78% specificity, in the task of detecting impacts under demanding laboratory conditions. The algorithm works together with an unsupervised real-time learning technique that addresses the adaptive capability, and this is also presented. The work demonstrates the robustness and reliability of our new algorithm, which will be the basis of a smart falling monitor. This is shown in this work to underline the relevance of the results.

  14. Malaysia and forced migration

    Directory of Open Access Journals (Sweden)

    Arzura Idris

    2012-06-01

    Full Text Available This paper analyzes the phenomenon of “forced migration” in Malaysia. It examines the nature of forced migration, the challenges faced by Malaysia, the policy responses and their impact on the country and upon the forced migrants. It considers forced migration as an event hosting multifaceted issues related and relevant to forced migrants and suggests that Malaysia has been preoccupied with the issue of forced migration movements. This is largely seen in various responses invoked from Malaysia due to “south-south forced migration movements.” These responses are, however, inadequate in terms of commitment to the international refugee regime. While Malaysia did respond to economic and migration challenges, the paper asserts that such efforts are futile if she ignores issues critical to forced migrants.

  15. Labor Force Participation Rate

    Data.gov (United States)

    City and County of Durham, North Carolina — This thematic map presents the labor force participation rate of working-age people in the United States in 2010. The 2010 Labor Force Participation Rate shows the...

  16. Three-nucleon forces

    International Nuclear Information System (INIS)

    Sauer, P.U.

    2014-01-01

    In this paper, the role of three-nucleon forces in ab initio calculations of nuclear systems is investigated. The difference between genuine and induced many-nucleon forces is emphasized. Induced forces arise in the process of solving the nuclear many-body problem as technical intermediaries toward calculationally converged results. Genuine forces make up the Hamiltonian. They represent the chosen underlying dynamics. The hierarchy of contributions arising from genuine two-, three- and many-nucleon forces is discussed. Signals for the need of the inclusion of genuine three-nucleon forces are studied in nuclear systems, technically best under control, especially in three-nucleon and four-nucleon systems. Genuine three-nucleon forces are important for details in the description of some observables. Their contributions to observables are small on the scale set by two-nucleon forces. (author)

  17. RSOI: Force Deployment Bottleneck

    National Research Council Canada - National Science Library

    D'Amato, Mark

    1998-01-01

    .... This runs counter to the popular belief that strategic lift is the limiting constraint. The study begins by highlighting the genesis of the military's current force projection strategy and the resulting importance of rapid force deployments...

  18. Acoustic force spectroscopy

    NARCIS (Netherlands)

    Sitters, G.; Kamsma, D.; Thalhammer, G.; Ritsch-Marte, M.; Peterman, E.J.G.; Wuite, G.J.L.

    2015-01-01

    Force spectroscopy has become an indispensable tool to unravel the structural and mechanochemical properties of biomolecules. Here we extend the force spectroscopy toolbox with an acoustic manipulation device that can exert forces from subpiconewtons to hundreds of piconewtons on thousands of

  19. Crossflow force transducer

    International Nuclear Information System (INIS)

    Mulcahy, T.M.

    1982-05-01

    A force transducer for measuring lift and drag coefficients for a circular cylinder in turbulent water flow is presented. In addition to describing the actual design and construction of the strain-gauged force- ring based transducer, requirements for obtained valid fluid force test data are discussed, and pertinent flow test experience is related

  20. Forces in General Relativity

    Science.gov (United States)

    Ridgely, Charles T.

    2010-01-01

    Many textbooks dealing with general relativity do not demonstrate the derivation of forces in enough detail. The analyses presented herein demonstrate straightforward methods for computing forces by way of general relativity. Covariant divergence of the stress-energy-momentum tensor is used to derive a general expression of the force experienced…

  1. Air Force Senior Leaders

    Science.gov (United States)

    Force TV Radio Week in Photos About Us Air Force Senior Leaders SECAF CSAF CMSAF Biographies Adjunct Professors Senior Mentor Biographies Fact Sheets Commander's Call Topics CCT Archive CSAF Reading List 2017 Media Sites Site Registration Contact Us Search AF.mil: Home > About Us > Air Force Senior Leaders

  2. Conjuring David Foster Wallace’s Ghost: Prosopopeia, Whitmanian Intimacy and the Queer Potential of Infinite Jest and The Pale King

    Directory of Open Access Journals (Sweden)

    Vincent Haddad

    2017-03-01

    Full Text Available This article analyzes the ways in which Wallace’s fiction stages homosocial intimacy between the (male author figure and (male reader through the conceptual metaphor of ghosts in both Infinite Jest and the unfinished novel 'The Pale King'. I specifically contrast Wallace’s use of prosopopeia, or inducing the reader to create the author’s face in moments of undecidability, with that of one of his under-explored influences, Walt Whitman. Whitman used the technique to stage an intimate, homosexual encounter in the future between himself and his imagined, posthumous readership. Through this contrast, the article demonstrates that Wallace’s narrative devices are particularly attuned to the production of the intimacies of male homosocial desire. I borrow my meaning of this term from Eve Sedgwick’s 'Between Men' (1985, in which she suggests that masculinity, by defining itself in opposition to male homosexuality, cannot acknowledge intimacy between heterosexual men as a manifestation of desire. Considering Wallace’s revisions of both the conceptual metaphor of ghosts as well as use of prosopopeia across both novels, the article argues that the homosocial intimacy staged between the masculinized author figure and his primarily, though not exclusively, white, heterosexual reading public is a fundamental effect of his aesthetic practice. However, the discontinuity between male homosocial desire and male homosexuality make this effect a too often unarticulated component of Wallace’s fiction and reception.

  3. Death, Innocence, and the Cyborg: Theorizing the Gynoid Double-Bind in Mamoru Oshii’s Ghost in the Shell II: Innocence

    Directory of Open Access Journals (Sweden)

    Tembo Kwasu D.

    2017-12-01

    Full Text Available In Donna Haraway’s “A Cyborg Manifesto” (1983, the author presents a discussion of the concept and praxis of the cyborg in emancipatory terms. Haraway presents the cyborg as a transgressive and latently mercurial figure that decouples and contravenes numerous exploitative ideological frameworks of repressive biopower that repress human being and reproduce the conditions of said repression. Using Mamoru Oshii’s Ghost in the Shell II: Innocence (2004 as a dialogic case study, this essay explores the manner in which the cyborg, particularly its figuration as female-gendered anthropic machine or gynoid in 20th- and 21st-century science fiction, simultaneously confirms and contradicts Haraway’s assessment of the concept of the cyborg. As to its methodology, this essay opens with a contextualizing excursus on the cyber-being in contemporary Western society and sociopolitics, with a view to offering a framework analysis of the figuration of the gynoid in Oshii’s Ghost in the Shell II: Innocence as a recent example of contemporary science fiction’s representation of the issues and debates inherent to the concept of the gynoid. Lastly, this essay performs a detailed close reading of Oshii’s text in relation to its exploration of themes of the conceptual emancipatory potential of the cyber-being and the paradoxically exploitative patriarchal power relations that re-inscribe said potential within what this essay refers to as ‘the gynoid double-bind.’

  4. Reduction of respiratory ghosting motion artifacts in conventional two-dimensional multi-slice Cartesian turbo spin-echo: which k-space filling order is the best?

    Science.gov (United States)

    Inoue, Yuuji; Yoneyama, Masami; Nakamura, Masanobu; Takemura, Atsushi

    2018-06-01

    The two-dimensional Cartesian turbo spin-echo (TSE) sequence is widely used in routine clinical studies, but it is sensitive to respiratory motion. We investigated the k-space orders in Cartesian TSE that can effectively reduce motion artifacts. The purpose of this study was to demonstrate the relationship between k-space order and degree of motion artifacts using a moving phantom. We compared the degree of motion artifacts between linear and asymmetric k-space orders. The actual spacing of ghost artifacts in the asymmetric order was doubled compared with that in the linear order in the free-breathing situation. The asymmetric order clearly showed less sensitivity to incomplete breath-hold at the latter half of the imaging period. Because of the actual number of partitions of the k-space and the temporal filling order, the asymmetric k-space order of Cartesian TSE was superior to the linear k-space order for reduction of ghosting motion artifacts.

  5. Environmental geophysics: Buildings E5485, E5487, and E5489 decommissioning - the open-quotes Ghost Townclose quotes complex, Aberdeen Proving Ground, Maryland

    International Nuclear Information System (INIS)

    McGinnis, L.D.; Thompson, M.D.; Miller, S.F.

    1994-06-01

    Buildings E5485, E5487, and E5489, referred to informally as the open-quotes Ghost Townclose quotes complex, are potentially contaminated sites in the Edgewood section of Aberdeen Proving Ground. Noninvasive geophysical surveys, including magnetics, EM-31, EM-61, and ground-penetrating radar, were conducted to assist a sampling and monitoring program prior to decommissioning and dismantling of the buildings. The buildings are located on a marginal wetland bordering the west branch of Canal Creek. The dominant geophysical signature in the open-quotes Ghost Town close quotes complex is a pattern of northeast-southwest and northwest-southeast anomalies that appear to be associated with a trench/pipe/sewer system, documented by the presence of a manhole. Combinations of anomalies suggest that line sources include nonmetallic and ferromagnetic materials in trenches. On the basis of anomaly associations, the sewer lines probably rest in a trench, back-filled with conductive, amphibolitic, crushed rock. Where the sewer lines connect manholes or junctions with other lines, ferromagnetic materials are present. Isolated, unidentified magnetic anomalies litter the area around Building E5487, particularly to the north. Three small magnetic sources are located east of Building E5487

  6. Review of A* (A Star Navigation Mesh Pathfinding as the Alternative of Artificial Intelligent for Ghosts Agent on the Pacman Game

    Directory of Open Access Journals (Sweden)

    Moh. Zikky

    2016-08-01

    Full Text Available Shortest pathfinding problem has become a populer issue in Game’s Artificial Intelligent (AI. This paper discussed the effective way to optimize the shortest pathfinding problem, namely Navigation Mesh (NavMesh. This method is very interesting because it has a large area of implementation, especially in games world. In this paper, NavMesh was implemented by using A* (A star algorithm and examined in Unity 3D game engine. A* was an effective algorithm in shortest pathfinding problem because its optimization was made with effective tracing using segmentation line. Pac-Man game was chosen as the example of the shortest pathfinding by using NavMesh in Unity 3D. A* algorithm was implemented on the enemies of Pac-Man (three ghosts,  which path was designed by using NavMesh concept. Thus, the movement of ghosts in catching Pac-Man was the result of this review of the effectiveness of this concept. In further research, this method could be implemented on several optimization programmes, such as Geographic Information System (GIS, robotics, and statistics.

  7. The Ghost-Image on Metropolitan Borders—In Terms of Phantom of the Opera and 19th-Century Metropolis Paris

    Directory of Open Access Journals (Sweden)

    Changnam Lee

    2013-12-01

    Full Text Available This paper reviews Gaston Leroux’s Phantom of the Opera in the context of the social and cultural changes of the metropolis Paris at the end of the 19th century. The Phantom of the Opera, a success in the literary world and widely proliferated in its musical and film renditions afterward, is considered and interpreted mainly in the literary and artistic tradition. In this paper, however, this work will be considered from an urban sociological perspective, especially from that of Walter Benjamin, who developed the theory of the urban culture, focusing on the dreaming collectives at the end of the 19th century. Leroux’s novel can be regarded as an exemplary social form of the collective dreams of the period expressed in arts, architectures, popular stories and films and other popular arts. Given the premise that the dream images in the novel, so-called kitsch, reflect the fears and desires of the bourgeois middle class that were pathologized in the figure of the ghost, this paper reveals the cultural, social and transnational implications of the Ghost-Image in relation to the rapidly changing borders of the 19th century metropolis.

  8. Nature of rate-limiting steps in a compartmentalized enzyme system. Quantitation of dopamine transport and hydroxylation rates in resealed chromaffin granule ghosts

    International Nuclear Information System (INIS)

    Ahn, N.G.; Klinman, J.P.

    1989-01-01

    Using isolated chromaffin granule ghosts from bovine adrenal medullae, we have studied the kinetics of dopamine beta-monooxygenase (D beta M) activity as it is linked to dopamine transport. Measurements of the initial rates of transport and of transport-linked norepinephrine formation suggested that enzyme activity may be partially rate-limiting in the coupled carrier/enzyme system. This was confirmed by (i) measurements of initial rates of norepinephrine formation using deuterated substrate, which gave isotope effects greater than 2.0, and (ii) kinetic measurements using ghosts pulsed with varying concentrations of labeled dopamine, which indicated substantial substrate accumulation in the vesicle interior as a function of time. Initial rates of product formation, when combined with approximations of internal substrate concentrations, allowed estimates of Kcat and Km for intravesicular D beta M. Activation by external reductant was apparent in both initial rate parameters and the measurements of transients. Under conditions of optimal D beta M activity, the enzyme rate parameters (kcat = 0.31 nmol/s.mg and Km = 2 mM) indicated partial rate limitation compared to dopamine transport (kcat = 0.38 nmol/s.mg and Km = 32 microM). Compartmental analysis of the time curves, performed using numerical nonlinear least squares methods, gave least squares estimates of rate constants for a simple carrier mechanism and kcat values for D beta M which were consistent with estimates from initial rates

  9. Quantum fictitious forces

    DEFF Research Database (Denmark)

    Bialynicki-Birula, I; Cirone, M.A.; Dahl, Jens Peder

    2002-01-01

    We present Heisenberg's equation of motion for the radial variable of a free non-relativistic particle in D dimensions. The resulting radial force consists of three contributions: (i) the quantum fictitious force which is either attractive or repulsive depending on the number of dimensions, (ii......) a singular quantum force located at the origin, and (iii) the centrifugal force associated with non-vanishing angular momentum. Moreover, we use Heisenberg's uncertainty relation to introduce a lower bound for the kinetic energy of an ensemble of neutral particles. This bound is quadratic in the number...... of atoms and can be traced back to the repulsive quantum fictitious potential. All three forces arise for a free particle: "Force without force"....

  10. TESTING GALAXY FORMATION MODELS WITH THE GHOSTS SURVEY: THE COLOR PROFILE OF M81's STELLAR HALO

    International Nuclear Information System (INIS)

    Monachesi, Antonela; Bell, Eric F.; Bailin, Jeremy; Radburn-Smith, David J.; Dalcanton, Julianne J.; Vlajić, Marija; De Jong, Roelof S.; Streich, David; Holwerda, Benne W.

    2013-01-01

    We study the properties of the stellar populations in M81's outermost part, which hereafter we will call the stellar halo, using Hubble Space Telescope (HST) Advanced Camera for Surveys observations of 19 fields from the GHOSTS survey. The observed fields probe the stellar halo out to a projected distance of ∼50 kpc from the galactic center. Each field was observed in both F606W and F814W filters. The 50% completeness levels of the color-magnitude diagrams (CMDs) are typically at 2 mag below the tip of the red giant branch (TRGB). Fields at distances closer than 15 kpc show evidence of disk-dominated populations whereas fields at larger distances are mostly populated by halo stars. The red giant branch (RGB) of the M81's halo CMDs is well matched with isochrones of ∼10 Gyr and metallicities [Fe/H] ∼ – 1.2 dex, suggesting that the dominant stellar population of M81's halo has a similar age and metallicity. The halo of M81 is characterized by a color distribution of width ∼0.4 mag and an approximately constant median value of (F606W – F814W) ∼1 mag measured using stars within the magnitude range 23.7 ∼ 15 kpc, we detect no color gradient in the stellar halo of M81. We place a limit of 0.03 ± 0.11 mag difference between the median color of RGB M81 halo stars at ∼15 and at 50 kpc, corresponding to a metallicity difference of 0.08 ± 0.35 dex over that radial range for an assumed constant age of 10 Gyr. We compare these results with model predictions for the colors of stellar halos formed purely via accretion of satellite galaxies. When we analyze the cosmologically motivated models in the same way as the HST data, we find that they predict no color gradient for the stellar halos, in good agreement with the observations.

  11. Energy-Based Design Criterion of Dissipative Bracing Systems for the Seismic Retrofit of Frame Structures

    Directory of Open Access Journals (Sweden)

    Gloria Terenzi

    2018-02-01

    Full Text Available Direct sizing criteria represent useful tools in the design of dissipative bracing systems for the advanced seismic protection of existing frame structures, especially when incorporated dampers feature a markedly non-linear behaviour. An energy-based procedure is proposed herein to this aim, focusing attention on systems including fluid viscous devices. The procedure starts by assuming prefixed reduction factors of the most critical response parameters in current conditions, which are evaluated by means of a conventional elastic finite element analysis. Simple formulas relating the reduction factors to the equivalent viscous damping ratio of the dampers, ξeq, are proposed. These formulas allow calculating the ξeq values that guarantee the achievement of the target factors. Finally, the energy dissipation capacity of the devices is deduced from ξeq, finalizing their sizing process. A detailed description of the procedure is presented in the article, by distinguishing the cases where the prevailing structural deficiencies are represented by poor strength of the constituting members, from the cases having excessive horizontal displacements. A demonstrative application to the retrofit design of a reinforced concrete gym building is then offered to explicate the steps of the sizing criterion in practice, as well as to evaluate the enhancement of the seismic response capacities generated by the installation of the dissipative system.

  12. From free energy to expected energy: Improving energy-based value function approximation in reinforcement learning.

    Science.gov (United States)

    Elfwing, Stefan; Uchibe, Eiji; Doya, Kenji

    2016-12-01

    Free-energy based reinforcement learning (FERL) was proposed for learning in high-dimensional state and action spaces. However, the FERL method does only really work well with binary, or close to binary, state input, where the number of active states is fewer than the number of non-active states. In the FERL method, the value function is approximated by the negative free energy of a restricted Boltzmann machine (RBM). In our earlier study, we demonstrated that the performance and the robustness of the FERL method can be improved by scaling the free energy by a constant that is related to the size of network. In this study, we propose that RBM function approximation can be further improved by approximating the value function by the negative expected energy (EERL), instead of the negative free energy, as well as being able to handle continuous state input. We validate our proposed method by demonstrating that EERL: (1) outperforms FERL, as well as standard neural network and linear function approximation, for three versions of a gridworld task with high-dimensional image state input; (2) achieves new state-of-the-art results in stochastic SZ-Tetris in both model-free and model-based learning settings; and (3) significantly outperforms FERL and standard neural network function approximation for a robot navigation task with raw and noisy RGB images as state input and a large number of actions. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  13. DC dynamic pull-in instability of a dielectric elastomer balloon: an energy-based approach

    Science.gov (United States)

    Sharma, Atul Kumar; Arora, Nitesh; Joglekar, M. M.

    2018-03-01

    This paper reports an energy-based method for the dynamic pull-in instability analysis of a spherical dielectric elastomer (DE) balloon subjected to a quasi-statically applied inflation pressure and a Heaviside step voltage across the balloon wall. The proposed technique relies on establishing the energy balance at the point of maximum stretch in an oscillation cycle, followed by the imposition of an instability condition for extracting the threshold parameters. The material models of the Ogden family are employed for describing the hyperelasticity of the balloon. The accuracy of the critical dynamic pull-in parameters is established by examining the saddle-node bifurcation in the transient response of the balloon obtained by integrating numerically the equation of motion, derived using the Euler-Lagrange equation. The parametric study brings out the effect of inflation pressure on the onset of the pull-in instability in the DE balloon. A quantitative comparison between the static and dynamic pull-in parameters at four different levels of the inflation pressure is presented. The results indicate that the dynamic pull-in instability gets triggered at electric fields that are lower than those corresponding to the static instability. The results of the present investigation can find potential use in the design and development of the balloon actuators subjected to transient loading. The method developed is versatile and can be used in the dynamic instability analysis of other conservative systems of interest.

  14. Energy-Based Wavelet De-Noising of Hydrologic Time Series

    Science.gov (United States)

    Sang, Yan-Fang; Liu, Changming; Wang, Zhonggen; Wen, Jun; Shang, Lunyu

    2014-01-01

    De-noising is a substantial issue in hydrologic time series analysis, but it is a difficult task due to the defect of methods. In this paper an energy-based wavelet de-noising method was proposed. It is to remove noise by comparing energy distribution of series with the background energy distribution, which is established from Monte-Carlo test. Differing from wavelet threshold de-noising (WTD) method with the basis of wavelet coefficient thresholding, the proposed method is based on energy distribution of series. It can distinguish noise from deterministic components in series, and uncertainty of de-noising result can be quantitatively estimated using proper confidence interval, but WTD method cannot do this. Analysis of both synthetic and observed series verified the comparable power of the proposed method and WTD, but de-noising process by the former is more easily operable. The results also indicate the influences of three key factors (wavelet choice, decomposition level choice and noise content) on wavelet de-noising. Wavelet should be carefully chosen when using the proposed method. The suitable decomposition level for wavelet de-noising should correspond to series' deterministic sub-signal which has the smallest temporal scale. If too much noise is included in a series, accurate de-noising result cannot be obtained by the proposed method or WTD, but the series would show pure random but not autocorrelation characters, so de-noising is no longer needed. PMID:25360533

  15. Energy-Based Adaptive Sliding Mode Speed Control for Switched Reluctance Motor Drive

    Directory of Open Access Journals (Sweden)

    M. M. Namazi Isfahani

    2012-03-01

    Full Text Available Torque ripple minimization of switched reluctance motor drives is a major subject based on these drives’ extensive use in the industry. In this paper, by using a well-known cascaded torque control structure and taking the machine physical structure characteristics into account, the proposed energy-based (passivity-based adaptive sliding algorithm derived from the view point of energy dissipation, control stability and algorithm robustness. First, a nonlinear dynamic model is developed and decomposed into separate slow and fast passive subsystems which are interconnected by negative feedbacks. Then, an outer loop speed control is employed by adaptive sliding controller to determine the appropriate torque command. Finally, to reduce torque ripple in switched reluctance motor a high-performance passivity-based current controller is proposed. It can overcome the inherent nonlinear characteristics of the system and make the whole system robust to uncertainties and bounded disturbances. The performance of the proposed controller algorithm has been demonstrated in simulation, and experimental using a 4KW, four-phase, 8/6 pole SRM DSP-based drive system.

  16. A low-cost approach to electronic excitation energies based on the driven similarity renormalization group

    Science.gov (United States)

    Li, Chenyang; Verma, Prakash; Hannon, Kevin P.; Evangelista, Francesco A.

    2017-08-01

    We propose an economical state-specific approach to evaluate electronic excitation energies based on the driven similarity renormalization group truncated to second order (DSRG-PT2). Starting from a closed-shell Hartree-Fock wave function, a model space is constructed that includes all single or single and double excitations within a given set of active orbitals. The resulting VCIS-DSRG-PT2 and VCISD-DSRG-PT2 methods are introduced and benchmarked on a set of 28 organic molecules [M. Schreiber et al., J. Chem. Phys. 128, 134110 (2008)]. Taking CC3 results as reference values, mean absolute deviations of 0.32 and 0.22 eV are observed for VCIS-DSRG-PT2 and VCISD-DSRG-PT2 excitation energies, respectively. Overall, VCIS-DSRG-PT2 yields results with accuracy comparable to those from time-dependent density functional theory using the B3LYP functional, while VCISD-DSRG-PT2 gives excitation energies comparable to those from equation-of-motion coupled cluster with singles and doubles.

  17. StringForce

    DEFF Research Database (Denmark)

    Barendregt, Wolmet; Börjesson, Peter; Eriksson, Eva

    2017-01-01

    In this paper, we present the forced collaborative interaction game StringForce. StringForce is developed for a special education context to support training of collaboration skills, using readily available technologies and avoiding the creation of a "mobile bubble". In order to play String......Force two or four physically collocated tablets are required. These tablets are connected to form one large shared game area. The game can only be played by collaborating. StringForce extends previous work, both technologically and regarding social-emotional training. We believe String......Force to be an interesting demo for the IDC community, as it intertwines several relevant research fields, such as mobile interaction and collaborative gaming in the special education context....

  18. Quantum anticentrifugal force

    International Nuclear Information System (INIS)

    Cirone, M.A.; Schleich, W.P.; Straub, F.; Rzazewski, K.; Wheeler, J.A.

    2002-01-01

    In a two-dimensional world, a free quantum particle of vanishing angular momentum experiences an attractive force. This force originates from a modification of the classical centrifugal force due to the wave nature of the particle. For positive energies the quantum anticentrifugal force manifests itself in a bunching of the nodes of the energy wave functions towards the origin. For negative energies this force is sufficient to create a bound state in a two-dimensional δ-function potential. In a counterintuitive way, the attractive force pushes the particle away from the location of the δ-function potential. As a consequence, the particle is localized in a band-shaped domain around the origin

  19. Relativistic Linear Restoring Force

    Science.gov (United States)

    Clark, D.; Franklin, J.; Mann, N.

    2012-01-01

    We consider two different forms for a relativistic version of a linear restoring force. The pair comes from taking Hooke's law to be the force appearing on the right-hand side of the relativistic expressions: d"p"/d"t" or d"p"/d["tau"]. Either formulation recovers Hooke's law in the non-relativistic limit. In addition to these two forces, we…

  20. Hydrostatic force sensor

    International Nuclear Information System (INIS)

    Evans, M.S.; Stoughton, R.S.; Kazerooni, H.

    1994-08-01

    This paper presents a theoretical and experimental investigation of a new kind of force sensor which detects forces by measuring an induced pressure change in a material of large Poisson's ratio. In this investigation we develop mathematical expressions for the sensor's sensitivity and bandwidth, and show that its sensitivity can be much larger and its bandwidth is usually smaller than those of existing strain-gage-type sensors. This force sensor is well-suited for measuring large but slowly varying forces. It can be installed in a space smaller than that required by existing sensors