http://hdl.handle.net/10174/1130 Sat, 25 Apr 2026 14:49:07 GMT 2026-04-25T14:49:07Z http://hdl.handle.net/10174/41767 Title: Heat flow and thermal gradients in Portugal Authors: Duque, Maria Rosa; Mendes-Victor, Luís Alberto Abstract: In this paper we present the available heat flow data in Portugal.The number and location of the boreholes don't allow contouring of heat flow; so, we show the heat flow values and thermal gradients, making some considerations about the anomalous values. Fri, 01 Jan 1988 00:00:00 GMT http://hdl.handle.net/10174/41767 1988-01-01T00:00:00Z http://hdl.handle.net/10174/36445 Title: Anomalias magnéticas, alturas do geóide e variações de temperatura na plataforma do SW de Portugal Authors: Duque, Maria Rosa Abstract: Geoid height values obtained with models EGM 84, EGM96 and EGM 2008 for the region under study present significant changes, ocurring in relatively short time intervals, which can be interpreted as density changes associated with temperature variations in the region. In the present work, studies were made with data of the geomagnetic field (average hourly values) obtained at the Magnetic Observatory of Coimbra, San Fernando and Almeria, and it was concluded that anomalies detected on February 27 of 1969 can be interpreted as being obtained by suprposition of additional magnetic fields (in relation to days 25 and 26th), initially with mainly horizontal component and later with mainly vertical component. These additional fields may be associated with ion movements with mainly vertical direction followed by mainly horizontal direction. The variation in the direction of the geomagnetic field and the associated electric field lines could lead to reorientation of dipolar molecules and temperature increase in the region, whixh may have caused opening cracks and fractures already existing in the region, facilitating the entry of large amounts of water to deep zones, with relatively high speeds and temperatures. Wed, 31 May 2023 23:00:00 GMT http://hdl.handle.net/10174/36445 2023-05-31T23:00:00Z http://hdl.handle.net/10174/36444 Title: Density Variations, Thermodynamic Properties and Earthquakes in the Horseshoe Basin Authors: Duque, Maria Rosa Editors: Pereira, Mário Gonzalez; Oliveira, Rui; Navarro, Patrícia; Bugalho, Lourdes Abstract: This work considers the hypotesis of heating of materials and water in the region of Bank of Gorringe and Horseshoe Basin before the earthquake of February 28, 1969. For this purpose, data from the magnetic field obtained in Magnetic Observatories of the Iberian Peninsula were analysed, and anomalies were observed, including strong variations in magnetic declination. A simple model was used to obtain the effect of heating two different media (peridotite and gabbro) in physical contact, with different thermal and mechanical properties. The results include compression of peridotite by gabbro and shear stresses in the contact of the two materials Sun, 01 Jan 2023 00:00:00 GMT http://hdl.handle.net/10174/36444 2023-01-01T00:00:00Z http://hdl.handle.net/10174/35380 Title: Addressing the effect of hole design on the performance of perforated plates Authors: Miguel, A. F. Abstract: Perforated plates have been used in a variety of applications for many years. Shading panels [1], sound absorption [2], separators and filters [3], heat exchangers [4], and applications requiring homogeneous flows [5] are just a few examples. Homogeneous flows are critical for climatization of enclosures and cooling purposes such as gas turbine blades. This ensures that the fluid is distributed evenly, and in case of blades it protects the blade surface from hot gases. This study is devoted to understanding fluid flow in perforated plates. Their performance and dependability are critical factors that are object of study in order to build, develop, evaluate, and manage perforated plates to maximize their functionality. The hole geometry has a direct impact on the transport properties of these plates. Understanding how the geometry of holes affects fluid flow is thus critical for designing increasingly efficient systems. As a result, we investigate the effects of hole design on fluid flow using a Computational Flow Dynamics approach. Plates with round holes and plates with square holes with porosities ranging from 0.2 to 0.8 are investigated. The numerical investigation is carried out for Reynolds numbers ranging from 102 to 104. Among the outcomes are equations for loss factors for each design. Fri, 30 Jun 2023 23:00:00 GMT http://hdl.handle.net/10174/35380 2023-06-30T23:00:00Z