375 research outputs found

    Gauge Consistent Wilson Renormalization Group I: Abelian Case

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    A version of the Wilson Renormalization Group Equation consistent with gauge symmetry is presented. A perturbative renormalizability proof is established. A wilsonian derivation of the Callan-Symanzik equation is given.Comment: Latex2e, 39 pages, 3 eps figures. Revised version to appear in Int. J. Mod. Phy

    Fluctuations of the Magnetization in Thin Films due to Conduction Electrons

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    A detailed analysis of damping and noise due to a {\it sd}-interaction in a thin ferromagnetic film sandwiched between two large normal metal layers is carried out. The magnetization is shown to obey in general a non-local equation of motion which differs from the the Gilbert equation and is extended to the non-adiabatic regime. To lowest order in the exchange interaction and in the limit where the Gilbert equation applies, we show that the damping term is enhanced due to interfacial effects but it also shows oscillations as a function of the film thickness. The noise calculation is however carried out to all orders in the exchange coupling constant. The ellipticity of the precession of the magnetization is taken into account. The damping is shown to have a Gilbert form only in the adiabatic limit while the relaxation time becomes strongly dependent on the geometry of the thin film. It is also shown that the induced noise characteristic of sd-exchange is inherently colored in character and depends on the symmetry of the Hamiltonian of the magnetization in the film. We show that the sd-noise can be represented in terms of an external stochastic field which is white only in the adiabatic regime. The temperature is also renormalized by the spin accumulation in the system. For large intra-atomic exchange interactions, the Gilbert-Brown equation is no longer valid

    Artificial neural networks for 3D cell shape recognition from confocal images

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    We present a dual-stage neural network architecture for analyzing fine shape details from microscopy recordings in 3D. The system, tested on red blood cells, uses training data from both healthy donors and patients with a congenital blood disease. Characteristic shape features are revealed from the spherical harmonics spectrum of each cell and are automatically processed to create a reproducible and unbiased shape recognition and classification for diagnostic and theragnostic use.Comment: 17 pages, 8 figure

    Plantio cruzado em cultivar de soja de tipo de crescimento determinado.

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    O objetivo desse trabalho foi avaliar a produtividade de grãos e o acamamento de plantas no cultivar de soja de tipo determinado BRS 295 RR, cultivada em diferentes arranjos espaciais de plantas, incluindo o plantio cruzado

    Efeito da adubação potássica no sabor de morangos.

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    O objetivo deste trabalho foi avaliar o efeito da adubação potássica sobre o sabor de morangos das cultivares Camino Real, Festival e Oso Grande

    Non-perturbative thermal flows and resummations

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    We construct a functional renormalisation group for thermal fluctuations. Thermal resummations are naturally built in, and the infrared problem of thermal fluctuations is well under control. The viability of the approach is exemplified for thermal scalar field theories. In gauge theories the present setting allows for the construction of a gauge-invariant thermal renormalisation group.Comment: 16 pages, eq (38) added to match published versio

    Plantio cruzado na cultura da soja em uma cultivar de tipo de crescimento indeterminado.

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    O objetivo desse trabalho foi avaliar a produtividade de grãos e o acamamento de plantas na cultivar de soja de hábito de crescimento indeterminado BRS 359 RR, em diferentes arranjos espaciais de plantas, constituídos por densidades de semeadura, espaçamentos entre fileiras e forma de plantio (cruzado e não cruzado)
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