1,855 research outputs found

    The fantastic in Spain during the late- nineteenth and early-twentieth centuries

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    This thesis has as its primary objective the drawing together and subsequent theorisation of diverse texts which can be understood to be examples of Spanish fantastic literature. It demonstrates that from nineteenth-century Realism and Naturalism (exemplified in narratives by Pérez Galdós, Alarcón and Pardo Bazán), through turn-of-the-century modernismo (Valle-Inclán and Zamacois) to twentieth- century proto-existentialism (Unamuno), a significant number of texts were produced which, in spite of the obvious differences between them, refute the widely held idea that 'the fantastic' and Spanish literature share little common ground. The thesis is therefore one more step along the journey of establishing that Spanish fantastic literature is as important and integral to the whole swathe of Spanish cultural production as it is in many other European countries. The critical analyses of the narratives push at the boundaries of previous interpretative strategies both in terms of the fantastic and of the texts themselves. The exception to this interrogation and reinvigoration of earlier interpretations is to be found in the approach to the narratives by Zamacois, which have hitherto received very little critical attention. These detailed readings draw out the complexities and intriguing perspectives which the fantastic in Spain presents to the attentive reader. By means of these textual analyses, the thesis also explores some of the various possibilities presented by the fantastic itself, putting flesh on the theoretical bones of several different critical discourses. Ultimately, this thesis charts a dynamic and coherent corpus of material which represents the process of the psychologisation of the supernatural from Romanticism onwards. Each successive text more starkly expresses the unreal horrors of the fractured human mind, as well as the mutations of the body. As such, the evolutionary history of the fantastic in Spain is shown to be more gripping and relevant than has hitherto been understood to be the case

    Creation and evolution of magnetic helicity

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    Projecting a non-Abelian SU(2) vacuum gauge field - a pure gauge constructed from the group element U - onto a fixed (electromagnetic) direction in isospace gives rise to a nontrivial magnetic field, with nonvanishing magnetic helicity, which coincides with the winding number of U. Although the helicity is not conserved under Maxwell (vacuum) evolution, it retains one-half its initial value at infinite time.Comment: Clarifying remarks and references added; 12 pages, 1 figure using BoxedEPSF, REVTeX macros; submitted to Phys Rev D; email to [email protected]

    Gauge vortex dynamics at finite mass of bosonic fields

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    The simple derivation of the string equation of motion adopted in the nonrelativistic case is presented, paying the special attention to the effects of finite masses of bosonic fields of an Abelian Higgs model. The role of the finite mass effects in the evaluation of various topological characteristics of the closed strings is discussed. The rate of the dissipationless helicity change is calculated. It is demonstrated how the conservation of the sum of the twisting and writhing numbers of the string is recovered despite the changing helicity.Comment: considerably revised to include errata to journal versio

    ``Smoke Rings'' in Ferromagnets

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    It is shown that bulk ferromagnets support propagating non-linear modes that are analogous to the vortex rings, or ``smoke rings'', of fluid dynamics. These are circular loops of {\it magnetic} vorticity which travel at constant velocity parallel to their axis of symmetry. The topological structure of the continuum theory has important consequences for the properties of these magnetic vortex rings. One finds that there exists a sequence of magnetic vortex rings that are distinguished by a topological invariant (the Hopf invariant). We present analytical and numerical results for the energies, velocities and structures of propagating magnetic vortex rings in ferromagnetic materials.Comment: 4 pages, 3 eps-figures, revtex with epsf.tex and multicol.sty. To appear in Physical Review Letters. (Postscript problem fixed.

    Measurement Of Quasiparticle Transport In Aluminum Films Using Tungsten Transition-Edge Sensors

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    We report new experimental studies to understand the physics of phonon sensors which utilize quasiparticle diffusion in thin aluminum films into tungsten transition-edge-sensors (TESs) operated at 35 mK. We show that basic TES physics and a simple physical model of the overlap region between the W and Al films in our devices enables us to accurately reproduce the experimentally observed pulse shapes from x-rays absorbed in the Al films. We further estimate quasiparticle loss in Al films using a simple diffusion equation approach.Comment: 5 pages, 6 figures, PRA

    Large Scale Structures a Gradient Lines: the case of the Trkal Flow

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    A specific asymptotic expansion at large Reynolds numbers (R)for the long wavelength perturbation of a non stationary anisotropic helical solution of the force less Navier-Stokes equations (Trkal solutions) is effectively constructed of the Beltrami type terms through multi scaling analysis. The asymptotic procedure is proved to be valid for one specific value of the scaling parameter,namely for the square root of the Reynolds number (R).As a result large scale structures arise as gradient lines of the energy determined by the initial conditions for two anisotropic Beltrami flows of the same helicity.The same intitial conditions determine the boundaries of the vortex-velocity tubes, containing both streamlines and vortex linesComment: 27 pages, 2 figure

    Thermal detection of single e-h pairs in a biased silicon crystal detector

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    We demonstrate that individual electron-hole pairs are resolved in a 1 cm2^2 by 4 mm thick silicon crystal (0.93 g) operated at \sim35 mK. One side of the detector is patterned with two quasiparticle-trap-assisted electro-thermal-feedback transition edge sensor (QET) arrays held near ground potential. The other side contains a bias grid with 20\% coverage. Bias potentials up to ±\pm 160 V were used in the work reported here. A fiber optic provides 650~nm (1.9 eV) photons that each produce an electron-hole (eh+e^{-} h^{+}) pair in the crystal near the grid. The energy of the drifting charges is measured with a phonon sensor noise σ\sigma \sim0.09 eh+e^{-} h^{+} pair. The observed charge quantization is nearly identical for h+h^+'s or ee^-'s transported across the crystal.Comment: 4 journal pages, 5 figure

    Resolving singular forces in cavity flow: Multiscale modeling from atoms to millimeters

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    A multiscale approach for fluid flow is developed that retains an atomistic description in key regions. The method is applied to a classic problem where all scales contribute: The force on a moving wall bounding a fluid-filled cavity. Continuum equations predict an infinite force due to stress singularities. Following the stress over more than six decades in length in systems with characteristic scales of millimeters and milliseconds allows us to resolve the singularities and determine the force for the first time. The speedup over pure atomistic calculations is more than fourteen orders of magnitude. We find a universal dependence on the macroscopic Reynolds number, and large atomistic effects that depend on wall velocity and interactions.Comment: 4 pages,3 figure

    Characterizing human vestibular sensory epithelia for experimental studies: new hair bundles on old tissue and implications for therapeutic interventions in ageing.

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    Balance disequilibrium is a significant contributor to falls in the elderly. The most common cause of balance dysfunction is loss of sensory cells from the vestibular sensory epithelia of the inner ear. However, inaccessibility of inner ear tissue in humans severely restricts possibilities for experimental manipulation to develop therapies to ameliorate this loss. We provide a structural and functional analysis of human vestibular sensory epithelia harvested at trans-labyrinthine surgery. We demonstrate the viability of the tissue and labeling with specific markers of hair cell function and of ion homeostasis in the epithelium. Samples obtained from the oldest patients revealed a significant loss of hair cells across the tissue surface, but we found immature hair bundles present in epithelia harvested from patients >60 years of age. These results suggest that the environment of the human vestibular sensory epithelium could be responsive to stimulation of developmental pathways to enhance hair cell regeneration, as has been demonstrated successfully in the vestibular organs of adult mice

    Intermittency in the Joint Cascade of Energy and Helicity

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    The statistics of the energy and helicity fluxes in isotropic turbulence are studied using high resolution direct numerical simulation. The scaling exponents of the energy flux agree with those of the transverse velocity structure functions through refined similarity hypothesis, consistent with Kraichnan's prediction \cite{Kr74}. The helicity flux is even more intermittent than the energy flux and its scaling exponents are closer to those of the passive scalar. Using Waleffe's helical decomposition, we demonstrate that the existence of positive mean helicity flux inhibits the energy transfer in the negative helical modes, a non-passive effect
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