1,236 research outputs found

    On the Non-Lorentz Invariance of M.W. Evans O(3)-Symmetry Law

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    Correcting a former proof of M.W. Evans it is shown that his O(3) hypothesis is not Lorentz invariant and hence no law of Physics.Comment: 5 page

    Outcome expectancy: A key factor to understanding childhood exposure to nature and children's pro-environmental behavior

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    Introduction Human behavior is largely responsible for the environmental issues we face today (Cook et al., 2013), requiring a deeper understanding of the substance and etiology of pro-environmental behaviors (Gifford, 2011; Otto, Kaiser, & Arnold, 2014; Schultz & Kaiser, 2012). Pro-environmental behavior refers to actions that contribute to the sustainability of nature (Schultz & Kaiser, 2012). Given that children will be the ones grappling with future environmental challenges, and that most environmental education programs are organized for youngsters, a better understanding of the factors and processes leading children to behave in a more environmentally responsible manner is relevant both for scientific and practical reasons. One of the most widely documented correlates of pro-environmental behavior is childhood experiences in natural environments (Chawla & Derr, 2012; Cheng & Monroe, 2012; Evans, Otto, & Kaiser, 2018). Several ideas have been offered to explain why experiences in nature at an early age could play a formative role in children's pro-environmental behaviors..

    Parametric Rietveld refinement

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    In this paper the method of parametric Rietveld refinement is described, in which an ensemble of diffraction data collected as a function of time, temperature, pressure or any other variable are fitted to a single evolving structural model. Parametric refinement offers a number of potential benefits over independent or sequential analysis. It can lead to higher precision of refined parameters, offers the possibility of applying physically realistic models during data analysis, allows the refinement of `non-crystallographic' quantities such as temperature or rate constants directly from diffraction data, and can help avoid false minima

    Inflammatory and immune system correlates of rape

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    The purpose of this study was to evaluate the feasibility of measuring stress hormones and immunity following rape. The long-term goal is to evaluate the predictive value of stress-immune-inflammatory responses to later health outcomes. Fifteen women reporting rape were compared with 16 control participants. Serum stress hormones, proinflammatory cytokines, acute phase proteins, functional assays, and lymphocyte subsets were measured in blood samples. Women reporting rape had higher cytotoxic cells, lower B lymphocyte counts, higher proinflammatory biomarkers, and decreased lymphocyte proliferation compared to the control group. This finding suggests that rape produces activation of the innate immunity and suppression of some aspects of adaptive immunity. If these immune changes persist, they may contribute to the pathophysiology of long-term health sequelae by provoking chronic inflammation and decreased cellular immunocompetence

    Transformation elastodynamics and active exterior acoustic cloaking

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    This chapter consists of three parts. In the first part we recall the elastodynamic equations under coordinate transformations. The idea is to use coordinate transformations to manipulate waves propagating in an elastic material. Then we study the effect of transformations on a mass-spring network model. The transformed networks can be realized with "torque springs", which are introduced here and are springs with a force proportional to the displacement in a direction other than the direction of the spring terminals. Possible homogenizations of the transformed networks are presented, with potential applications to cloaking. In the second and third parts we present cloaking methods that are based on cancelling an incident field using active devices which are exterior to the cloaked region and that do not generate significant fields far away from the devices. In the second part, the exterior cloaking problem for the Laplace equation is reformulated as the problem of polynomial approximation of analytic functions. An explicit solution is given that allows to cloak larger objects at a fixed distance from the cloaking device, compared to previous explicit solutions. In the third part we consider the active exterior cloaking problem for the Helmholtz equation in 3D. Our method uses the Green's formula and an addition theorem for spherical outgoing waves to design devices that mimic the effect of the single and double layer potentials in Green's formula.Comment: Submitted as a chapter for the volume "Acoustic metamaterials: Negative refraction, imaging, lensing and cloaking", Craster and Guenneau ed., Springe

    Deflection of coronal rays by remote CMEs: shock wave or magnetic pressure?

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    We analyze five events of the interaction of coronal mass ejections (CMEs) with the remote coronal rays located up to 90^\circ away from the CME as observed by the SOHO/LASCO C2 coronagraph. Using sequences of SOHO/LASCO C2 images, we estimate the kink propagation in the coronal rays during their interaction with the corresponding CMEs ranging from 180 to 920 km/s within the interval of radial distances form 3 R. to 6 R. . We conclude that all studied events do not correspond to the expected pattern of shock wave propagation in the corona. Coronal ray deflection can be interpreted as the influence of the magnetic field of a moving flux rope related to a CME. The motion of a large-scale flux rope away from the Sun creates changes in the structure of surrounding field lines, which are similar to the kink propagation along coronal rays. The retardation of the potential should be taken into account since the flux rope moves at high speed comparable with the Alfven speed.Comment: Accepted for Publication in Solar Physic

    Flowing with Eight Supersymmetries in M-Theory and F-theory

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    We consider holographic RG flow solutions with eight supersymmetries and study the geometry transverse to the brane. For both M2-branes and for D3-branes in F-theory this leads to an eight-manifold with only a four-form flux. In both settings there is a natural four-dimensional hyper-Kahler slice that appears on the Coulomb branch. In the IIB theory this hyper-Kahler manifold encodes the Seiberg-Witten coupling over the Coulomb branch of a U(1) probe theory. We focus primarily upon a new flow solution in M-theory. This solution is first obtained using gauged supergravity and then lifted to eleven dimensions. In this new solution, the brane probes have an Eguchi-Hanson moduli space with the M2-branes spread over the non-trivial 2-sphere. It is also shown that the new solution is valid for a class of orbifold theories. We discuss how the hyper-Kahler structure on the slice extends to some form of G-structure in the eight-manifold, and describe how this can be computed.Comment: 29 pages, 1 figure, harvma

    An assessment of Evans' unified field theory I

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    Evans developed a classical unified field theory of gravitation and electromagnetism on the background of a spacetime obeying a Riemann-Cartan geometry. This geometry can be characterized by an orthonormal coframe theta and a (metric compatible) Lorentz connection Gamma. These two potentials yield the field strengths torsion T and curvature R. Evans tried to infuse electromagnetic properties into this geometrical framework by putting the coframe theta to be proportional to four extended electromagnetic potentials A; these are assumed to encompass the conventional Maxwellian potential in a suitable limit. The viable Einstein-Cartan(-Sciama-Kibble) theory of gravity was adopted by Evans to describe the gravitational sector of his theory. Including also the results of an accompanying paper by Obukhov and the author, we show that Evans' ansatz for electromagnetism is untenable beyond repair both from a geometrical as well as from a physical point of view. As a consequence, his unified theory is obsolete.Comment: 39 pages of latex, modified because of referee report, mistakes and typos removed, partly reformulated, taken care of M.W.Evans' rebutta

    Debye screening and Meissner effect in a two-flavor color superconductor

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    I compute the gluon self-energy in a color superconductor with two flavors of massless quarks, where condensation of Cooper pairs breaks SU(3)_c to SU(2)_c. At zero temperature, there is neither Debye screening nor a Meissner effect for the three gluons of the unbroken SU(2)_c subgroup. The remaining five gluons attain an electric as well as a magnetic mass. For temperatures approaching the critical temperature for the onset of color superconductivity, or for gluon momenta much larger than the color-superconducting gap, the self-energy assumes the form given by the standard hard-dense loop approximation. The gluon self-energy determines the coefficient of the kinetic term in the effective low-energy theory for the condensate fields.Comment: 29 pages, RevTe
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