1,567 research outputs found

    A topological mechanism of discretization for the electric charge

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    We present a topological mechanism of discretization, which gives for the fundamental electric charge a value equal to the square root of the Planck constant times the velocity of light, which is about 3.3 times the electron charge. Its basis is the following recently proved property of the standard linear classical Maxwell equations: they can be obtained by change of variables from an underlying topological theory, using two complex scalar fields, the level curves of which coincide with the magnetic and the electric lines, respectively.Comment: 10 pages, LaTeX fil

    Phase behavior, kinetics and structural aspects of (semi-) clathrate hydrate systems

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    Resources and Services for Parents with Children with Disabilities

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    Resources and Services for Latino parents with children with disabilities. How to know children\u27s rights, what accommodation children with disabilities are in title to receive, agencies, and laws that parents need to know to advocate for the benefit of their children with disabilities

    On the mechanism of branching in negative ionization fronts

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    We explain a mechanism for branching of a planar negative front. Branching occurs as the result of a balance between the destabilizing effect of impact ionization and the stabilizing effect of electron diffusion on ionization fronts. The dispersion relation for transversal perturbation is obtained analytically and reads: s=k/[2(1+k)]Dk2s = |k|/[2 (1 + |k|)] - D |k|^2, where DD, which is assumed to be small, is the ratio between the electron diffusion coefficient and the intensity of the externally imposed electric field. We estimate the spacing λ\lambda between streamers in a planar discharge and deduce a scaling law λD1/3\lambda \sim D^{1/3}

    Ground temperatures, landforms and processes in an Atlantic mountain. Cantabrian Mountains (Northern Spain)

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    This research was supported by the Formación de Profesorado Universitario FPU13/05837 (Ministerio de Educación Cultura y Deporte) program, by the OAPN 053/2010 (Organismo Autónomo Parques Nacionales, MAGRAMA) project, by the I + D + I CGL2015-68144-R (Ministerio de Economia y Competitividad) project, by the Leverhulme Trust International Network Grant IN-2012-140 and the Royal Geographical Society Dudley Stamp Memorial Award.Peer reviewedPostprin

    Ionization fronts in negative corona discharges

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    In this paper we use a hydrodynamic minimal streamer model to study negative corona discharge. By reformulating the model in terms of a quantity called shielding factor, we deduce laws for the evolution in time of both the radius and the intensity of ionization fronts. We also compute the evolution of the front thickness under the conditions for which it diffuses due to the geometry of the problem and show its self-similar character.Comment: 4 pages, 4 figure

    Advanced titanium scaffolds obtained by directional freeze-drying: on the influence of processing conditions

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    Ministry of Science and Innovation of Spain under Grant No. MAT2010-20855Junta de Andalucía (Spain) / FEDER (EU), through the project Ref. P12-TEP-140

    Power laws and self-similar behavior in negative ionization fronts

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    We study anode-directed ionization fronts in curved geometries. When the magnetic effects can be neglected, an electric shielding factor determines the behavior of the electric field and the charged particle densities. From a minimal streamer model, a Burgers type equation which governs the dynamics of the electric shielding factor is obtained. A Lagrangian formulation is then derived to analyze the ionization fronts. Power laws for the velocity and the amplitude of streamer fronts are observed numerically and calculated analytically by using the shielding factor formulation. The phenomenon of geometrical diffusion is explained and clarified, and a universal self-similar asymptotic behavior is derived.Comment: 25 pages, 9 figure
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