14,764 research outputs found

    Hawking radiation for non asymptotically flat dilatonic black holes using gravitational anomaly

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    The dd-dimensional scalar field action may be reduced, in the background geometry of a black hole, to a 2-dimensional effective action. In the near horizon region, it appears a gravitational anomaly: the energy-momentum tensor of the scalar field is not conserved anymore. This anomaly is removed by introducing a term related to the Hawking temperature of the black hole. Even if the temperature term introduced is not covariant, a gauge transformation may restore the covariance. We apply this method to compute the temperature of the black hole of the dilatonic non asymptotically flat black holes. We compare the results with those obtained through other methods.Comment: Latex file, 22 pages. Some discussions enlarged. New references. Accepted for publication in the European Physical Journal

    A parity conserving dimer model with infinitely many absorbing states

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    We propose and study a model where, for the first time, two aspects are present: parity conservation and infinitely many absorbing states. Whereas steady-state simulations show that the static critical behaviour is not affected by the presence of multiple absorbing configurations, the influence of the initial state associated with the presence of slowly decaying memory effects is clearly displayed in time dependent simulations. We report results of a detailed investigation of the dependence of critical spreading exponents on the initial particle density.Comment: 4 pages, 3 figures.p

    Abrasion of flat rotating shapes

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    We report on the erosion of flat linoleum "pebbles" under steady rotation in a slurry of abrasive grit. To quantify shape as a function of time, we develop a general method in which the pebble is photographed from multiple angles with respect to the grid of pixels in a digital camera. This reduces digitization noise, and allows the local curvature of the contour to be computed with a controllable degree of uncertainty. Several shape descriptors are then employed to follow the evolution of different initial shapes toward a circle, where abrasion halts. The results are in good quantitative agreement with a simple model, where we propose that points along the contour move radially inward in proportion to the product of the radius and the derivative of radius with respect to angle

    Equation of state for hard square lattice gases

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    A simple equation of state for a lattice gas of hard squares of side length λ\lambda is presented. Comparing to the Monte Carlo simulations, the new equation of state is found to be quite accurate for the disordered fluid phase

    Analysis of X-ray spectra emitted from laser-produced plasmas of uranium

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    In this paper, we used the multiconfiguration Dirac-Fock method to generate theoretical X-ray spectra for Co-, Ni-, Cu-, Zn-, Ga-, Ge-, As-, Se-, Br-, Kr-, and Rb-like uranium ions. Using the distribution of these ions in a laser-produced plasma, for different plasma temperatures, we generate theoretical spectra, which are compared to experimental data

    Stress waves in transversely isotropic media: The homogeneous problem

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    The homogeneous problem of stress wave propagation in unbounded transversely isotropic media is analyzed. By adopting plane wave solutions, the conditions for the existence of the solution are established in terms of phase velocities and directions of particle displacements. Dispersion relations and group velocities are derived from the phase velocity expressions. The deviation angles (e.g., angles between the normals to the adopted plane waves and the actual directions of their propagation) are numerically determined for a specific fiber-glass epoxy composite. A graphical method is introduced for the construction of the wave surfaces using magnitudes of phase velocities and deviation angles. The results for the case of isotropic media are shown to be contained in the solutions for the transversely isotropic media

    The C-terminal extension of the beta 7 subunit and activator complexes stabilize nascent 20 S proteasomes and promote their maturation

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    The eukaryotic 20 S proteasome is formed by dimerization of two precursor complexes containing the maturation factor Ump1. beta 7/Pre4 is the only one of the 14 subunits forming the 20 S proteasome that is absent from these precursor complexes in Saccharomyces cerevisiae. Increased expression of Pre4 leads to a reduction in the level of precursor complex, indicating that Pre4 incorporation into these complexes is rate-limiting for their dimerization. When we purified these precursor complexes, we observed co-purification of Blm10, a large protein known to attach to the alpha ring surface of proteasomes. In contrast to single mutants lacking either Blm10 or the C-terminal extension of Pre4, a mutant lacking both grew extremely poorly, accumulated very high levels of precursor complexes, and was impaired in beta subunit maturation. The effect of blm10 Delta on proteasome biogenesis is modest, apparently because the 19 S regulatory particle is capable of substituting for Blm10, as long as precursor complex dimers are stabilized by the Pre4Cterminus. We found that a mutation (sen3/rpn2) affecting the Rpn2 subunit inhibits attachment of the 19 S activator to the 20 S particle or its precursors. Although the sen3 mutation alone had no apparent effect on precursor complex dimerization and active site maturation, the sen3 blm10 double mutant was impaired in these processes. Together these data demonstrate that Blm10 and the 19 S activator have a partially redundant function in stabilizing nascent 20 S proteasomes and in promoting their activation.info:eu-repo/semantics/publishedVersio

    Contributions to the ontology of aging, the sensitive indicators of rehabilitation nursing care, in terms of self-care, in people with respiratory disorders

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    With the increase in the average life expectancy, the appearance of chronic diseases and, in particular, in the respiratory forum and its disadvantages in the autonomy and self-care of patients, brought an important paradigm for health care and, in particular, rehabilitation nursing, with implications for the development of ontologies of aging. Thus, it is imperative to systematize them in scientifically measurable indicators to demonstrate the benefit that rehabilitation nursing brings to improve patients' quality of life, thus ensuring excellence. Each area of scientific health should contribute to the construction of aging ontology. Objective: to identify indicators sensitive to nursing care of rehabilitation, in terms of self-care, in relation to those with respiratory pathology, to be integrated into the ontology of aging. Methods: A systematic review of the literature was performed using the EBSCO (full-text MEDLINE, CINAHL, Full-Text Plus, British Nursing Index), using the PI [C] O method with 6 emergent articles. Results: A total of 20 indicators were identified, including: Ability to perform activities, increase physical and functional independence, symptom management, reduction of complications, increase in quality of life, which can be allocated as a proposal for classes of the aging ontology. Conclusion: Knowledge of indicators sensitive to nursing care recognition of the importance of rehabilitation nursing in increasing self-care and autonomy for people with respiratory pathology, and research in this area is fundamental for its effectiveness and efficiency, and its integration in the ontologies of aging is fundamental
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