Bifurcation Analysis of the Watt Governor System

This paper pursues the study carried out by the authors in {\it Stability and Hopf bifurcation in the Watt governor system} \cite{smb}, focusing on the codimension one Hopf bifurcations in the centrifugal Watt governor differential system, as presented in Pontryagin's book {\it Ordinary Differential Equations}, \cite{pon}. Here are studied the codimension two and three Hopf bifurcations and the pertinent Lyapunov stability coefficients and bifurcation diagrams, illustrating the number, types and positions of bifurcating small amplitude periodic orbits, are determined. As a consequence it is found a region in the space of parameters where an attracting periodic orbit coexists with an attracting equilibrium.Comment: 34 pages, 9 figure

A sociedade política joanina (1383 - 1433): Para uma visáo de conjunto.

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Diplomática e História do Direito, raízes da «nova» História política*

Las ciencias de incidencia histórica (y entre ellas la Diplomática) como áreas en las que la tradición de los saberes es fuerte (Mabillon, João Pedro Ribeiro o Agustín Millares Carló, por ejemplo, siguen siendo referencias…) y en donde el Derecho como “Ciencia de lo continuo”: dos familias intelectuales que en Portugal, en los últimos años, parecen especialmente abocadas al diálogo interdisciplinar.The sciences in which the history is called (and among them the Diplomacy) as areas in which the tradition of knowlegde is strong (Mabillon, João Pedro Ribeiro or Agustín Millares Carló, for example, still constitute a reference…) and where the Law, as the “Science of the Continuum”: two intellectual families called to the interdisciplinar dialogue in the Portuguese scientific scene of the last years

Rei e «estado real» nos textos legislativos da Idade Média portuguesa.

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Weak measurement og the composite Goo-Haenchen shift in the critical region

By using a weak measurement technique, we investigated the interplay between the angular and lateral Goos-Haenchen shift of a focused He-Ne laser beam for incidence near the critical angle. We verified that this interplay dramatically affects the composite Goos-Haenchen shift of the propagated beam. The experimental results confirm theoretical predictions that recently appeared in the literature.Comment: 10 pages, 3 figure