375 research outputs found
Gauge Consistent Wilson Renormalization Group I: Abelian Case
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
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intra-atomic exchange interactions, the Gilbert-Brown equation is no longer
valid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
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.
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.
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
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.
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)
Evolução do Índice de Vegetação por Diferença Normalizada (NDVI) da soja em semeadura cruzada e não cruzada.
Redução do espaçamento entre fileiras na produtividade de duas cultivares de soja sob diferentes densidades de semeadura.
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