Renormalisation scheme for vector fields on T2 with a diophantine frequency

We construct a rigorous renormalisation scheme for analytic vector fields on the 2-torus of Poincare type. We show that iterating this procedure there is convergence to a limit set with a ``Gauss map'' dynamics on it, related to the continued fraction expansion of the slope of the frequencies. This is valid for diophantine frequency vectors.Comment: final versio

Aspectos agronômicos, fitopatológicos e socioeconômicos da sigatoka-negra na cultura da bananeira no Estado do Amapá

Sigatoka-negra da bananeira no Amapá: um desafio à pesquisa científica; A cultura da bananeira; Aspectos do melhoramento genético da bananeira; Sigatoka-negra: aspectos fitopatológicos no Amapá; Características físico-químicas de frutos de bananeiras resistentes à sigatoka-negra; Sigatoka-negra: repercussões socioeconômicas no Estado do Amapá; Dinâmica no desempenho da capacidade produtiva da bananicultura amapaense.bitstream/item/84394/1/AP-2011-aspectos-agronomicos-fitopatologicos-bananeiras.pd

A note on Kerr/CFT and free fields

The near-horizon geometry of the extremal four-dimensional Kerr black hole and certain generalizations thereof has an SL(2,R) x U(1) isometry group. Excitations around this geometry can be controlled by imposing appropriate boundary conditions. For certain boundary conditions, the U(1) isometry is enhanced to a Virasoro algebra. Here, we propose a free-field construction of this Virasoro algebra.Comment: 10 pages, v2: comments and references adde

On the Effects of Residual Stresses Induced by Coated and Uncoated Cutting Tools with Finite Edge Radii in Turning Operations

This paper presents an analysis of residual stresses in turning of AISI 316L and AISI 1045 steels with coated and uncoated tools having finite edge radii. An analytical predictive model, and experimental techniques involving X-ray diffraction and IR thermal imaging were used. Machining with coated tools produce higher superficial residual stresses, larger tensile layer thickness and higher residual stresses below the machined surface when using large cutting edge radii at low feed rates. This effect is correlated with the increase in the amount of heat conducted into the workpiece, and the associated generation of high tensile residual stresses and severe work-hardening.http://www.sciencedirect.com/science/article/B8CXH-4P37B21-X/1/ade5f4d85d7cb77cb37cbb62ae400bb

Pintarolas, a tangible sketch application

This paper presents Pintarolas, a simple sketch application that uses tangible interfaces as Human-Computer lnteraction modality. Totally sensor-less and cable-less interfaces (ordinary boardmarkers with fiducial markers attached), provide the means to support basic sketching tasks, such as drawing lines and sketching 2D primitive shapes (circle, triangle and square). The system requires an ordinary video camera linked to a PC and uses AR Toolkit for the handling of the Tangible Interfaces. Open GL is used for the graphical output and the CALI library, normally used for Calligraphic user interfaces development, is adopted in our case for 2D primilive shape recognition. A simple usability test was developed to assess the feasibility of this novel user interface in simple sketching tasks, showing that the users found the concept interesting and the tangible interfaces easy to operate.info:eu-repo/semantics/publishedVersio