http://hdl.handle.net/10174/973 Thu, 09 Apr 2026 19:55:53 GMT 2026-04-09T19:55:53Z http://hdl.handle.net/10174/11607 Title: “The Political History of Nineteenth-Century Portugal Authors: Baiôa, Manuel Abstract: The political history of nineteenth-century Portugal was, for a long time, a neglected subject. Under Salazar's New State it was passed over in favour of earlier periods from which that nationalist regime sought to draw inspiration; subsequent historians preferred to concentrate on social and economic developments to the detriment of the difficult evolution of Portuguese liberalism. This picture is changing, thanks to an awakening of interest in both contemporary topics and political history (although there is no consensus when it comes to defining political history). The aim of this article is to summarise these recent developments in Portuguese historiography for the benefit of an English-language audience. Wed, 01 Jan 2003 00:00:00 GMT http://hdl.handle.net/10174/11607 2003-01-01T00:00:00Z http://hdl.handle.net/10174/9450 Title: Time scaling internal state predictive control of a solar plant Authors: Silva, Rui Neves; Rato, Luis; Lemos, João Abstract: The control of a distributed collector solar field is addressed in this work, exploiting the plant's transport characteristic. The plant is modeled by a hyperbolic type partial differential equation (PDE) where the transport speed is the manipulated flow, i.e. the controller output. The model has an external distributed source, which is the solar radiation captured along the collector, approximated to depend only of time. From the solution of the PDE, a linear discrete state space model is obtained by using time-scaling and the redefinition of the control input. This method allows overcoming the dependency of the time constants with the operating point. A model-based predictive adaptive controller is derived with the internal temperature distribution estimated with a state observer. Experimental results at the solar power plant are presented, illustrating the advantages of the approach under consideration. Mon, 01 Dec 2003 00:00:00 GMT http://hdl.handle.net/10174/9450 2003-12-01T00:00:00Z