Local dimension and finite time prediction in coupled map lattices

Forecasting, for obvious reasons, often become the most important goal to be achieved. For spatially extended systems (e.g. atmospheric system) where the local nonlinearities lead to the most unpredictable chaotic evolution, it is highly desirable to have a simple diagnostic tool to identify regions of predictable behaviour. In this paper, we discuss the use of the bred vector (BV) dimension, a recently introduced statistics, to identify the regimes where a finite time forecast is feasible. Using the tools from dynamical systems theory and Bayesian modelling, we show the finite time predictability in two-dimensional coupled map lattices in the regions of low BV dimension. © Indian Academy of Sciences.

Effect of lithium doping on the evolution of rheological and structural properties during gelation of siloxane-poly(oxypropylene) nanocomposites

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Super-Poincaré covariant two-loop superstring amplitudes

The super-Poincaré covariant formalism for the superstring is used to compute massless four-point two-loop amplitudes in ten-dimensional superspace. The computations are much simpler than in the RNS formalism and include both external bosons and fermions. © SISSA 2006.

Preparation of lanthanum doped Bi4Ti3O12 ceramics by the polymeric precursor method

Lanthanum-modified bismuth titanate, Bi4 - xLaxTi3O12 (BLT) ceramics, with x ranging from 0 to 0.75 were prepared by the polymeric precursor method. Orthorhombicity of the system is decreased with the increase of lanthanum content in the bismuth titanate (BIT) crystal lattice. No secondary phases were evident after lanthanum addition. Increasing lanthanum content causes a structural distortion in the bismuth titanate lattice. The shape of the grains is strongly influenced by the lanthanum added to the system. © 2005 Elsevier B.V. All rights reserved.

Identification of lattices from genus of compact surface

In this work we propose procedures for the identification of structure of group associate lattices from fundamental region F4g of regular tessellations {4g; 4g} in the Euclidian plane and hyperbolic plane, where g denote genus of compact surface. © 2006 SBrT.

Digestibilidade de uma dieta caseira e dois alimentos comerciais, econômico e super-prêmio, para cães

They were compared the coefficients of apparent digestibility (CAD) and the fecal quality of dogs fed a home-made diet and two dog foods, standard and super-premium. Six adult dogs were distributed in a double latin square desing (3 × 3), with three treatments and three periods, in a total of six replications per treatment. Tukey's test was used to compare the means. The home-made diet presented the highest CAD, not differing only of the CAD of acid ether extract of the super-premium food. The standard food was the lowest digestive, producting more feces. Fecal dry matter of dogs fed home-made diet was lower than in the standard and super-premium foods, which did not differ among then. Fecal score presented low variability among treatments, remaining in the considered ideal range. Home-made diet can be an alternative in the feeding of dogs.

Rapid determination of furosemide by combined spot test/diffuse reflectance spectroscopy to detect doping in sport

This paper describes the development and application of a simple, cheap, and clean method for the quantification of furosemide in urine samples from athletes, to detect doping, using a combined spot test/diffuse reflectance spectroscopy procedure. The method is based on the complexation reaction of furosemide (5-(aminosulfonyl)-4-chloro-2-((furanylmethyl)amino)benzoic acid, dissolved in ethanol, with FeCl3 and the surfactant dodecyltrimethylammonium bromide (DTAB) in aqueous solution, yielding a colored compound on the surface of a filter paper. The reagent concentrations were optimized using a chemometric experimental design. The reflectometric measurements of the complex formed were carried out at 477nm. The linear range obtained was 1.65-9.00×10-3molL-1 of furosemide (R=0.997), and the detection and quantification limits were 4.9×10-4 and 1.62×10-3molL-1, respectively. The proposed method was successfully applied in the analysis of furosemide in spiked urine, demonstrating that it is a reliable alternative method for the detection of furosemide doping in sport. © 2012 Elsevier B.V..

Dynamics of rotation of super-Earths

We numerically investigate the dynamics of rotation of several close-in terrestrial exoplanet candidates. In our model, the rotation of the planet is disturbed by the torque of the central star due to the asymmetric equilibrium figure of the planet. We model the shape of the planet by a Jeans spheroid. We use surfaces of section and spectral analysis to explore numerically the rotation phase space of the systems adopting different sets of parameters and initial conditions close to the main spin-orbit resonant states. One of the parameters, the orbital eccentricity, is critically discussed here within the domain of validity of orbital circularization timescales given by tidal models. We show that, depending on some parameters of the system like the radius and mass of the planet, eccentricity etc., the rotation can be strongly perturbed and a chaotic layer around the synchronous state may occupy a significant region of the phase space. 55 Cnc e is an example. © 2013 Springer Science+Business Media Dordrecht.

Effect of yttrium doping in barium zirconium titanate ceramics: A structural, impedance, modulus spectroscopy study

In the current article, we studied the effect of yttrium [Y3+] ions' substitution on the structure and electric behavior of barium zirconate titanate (BZT) ceramics with a general formula [Ba1-x Y 2x/3](Zr0.25Ti0.75)O3 (BYZT) with [x = 0, 0.025, 0.05] which were prepared by the solid-state reaction method. X-ray diffraction patterns indicate that these ceramics have a single phase with a perovskite-type cubic structure. Rietveld refinement data confirmed [BaO 12], [ZrO6], [TiO6], [YO6] clusters in the cubic lattice. The Y3+ ions' effects on the electric conductivity behavior of BZT ceramics as a function of temperature and frequency are described, which are based on impedance spectroscopy analyses. The complex impedance plots display a double semicircle which highlights the influences of grain and grain boundary on the ceramics. Impedance analyses showed that the resistance decreased with the increasing temperature and resulted in a negative temperature coefficient of the resistance property in all compositions. Modulus plots represent a non-Debye-type dielectric relaxation which is related to the grain and grain boundary as well as temperature-dependent electric relaxation phenomenon and an enhancement in the mobility barrier by Y3+ ions. Moreover, the electric conductivity increases with the replacement of Ba 2+ by Y3+ ions may be due to the rise in oxygen vacancies. © 2013 The Minerals, Metals & Materials Society and ASM International.

Simulação computacional de materiais com elétrons fortemente interagentes: DMRG aplicado a super-redes Hubbard com modulação de condução entre camadas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Desenvolvimento de métodos analíticos limpos para determinações forenses: chumbo em resíduos de disparo e furosemida em doping

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A descentralização do conceito de super-herói paladino e a crise de identidade pós-moderna

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

MHV tree amplitudes in super-Yang-Mills and in superstring theory

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Capacidade combinatória de linhagens S4 de milho super-doce (Zea mays L.), portadoras do gene shrunken-2

Pós-graduação em Agronomia (Agricultura) - FCA

Avaliação de híbridos simples braquíticos de milho super doce (Zea mays L.) portadores do gene shrunken-2 (sh2sh2) utilizando o esquema dialélico parcial

Pós-graduação em Agronomia (Agricultura) - FCA