AMS and IRM studies in the late-variscan Santa Eulália Plutonic Complex (Ossa-Morena Zone, Portugal)

The Santa Eulália Plutonic Complex (SEPC) is a calc-alkaline granitic body, with an area of 400 km2, and is located in the north of the Ossa Morena Zone of the Variscan Iberian sector, near the limit with the Central Iberian Zone. SEPC is considered late-Variscan because it cross-cuts the regional variscan structures. The host rocks are metamorphic formations from Upper Proterozoic to Lower Paleozoic. The SEPC has two main granitic facies with different compositions and textures. From the rim to the core, there is a medium-to coarse-grained pink granite (G0), which involves large elongated masses of mafic to intermediate rocks (M); and a central grey monzonitic granite (G1) which presents a dominant medium granular facies, and also a slight porphyritic texture close to G0. AMS and IRM studies were conducted to characterise these rocks, from 61 sampling sites: 29 in G0, 27 in G1 and 5 in M. The Km values range between 41.6 and 7343.7 x 10-6 SI in granitic rocks: G0, with Km > 10-3 SI (mean: 1357.4 x 10-6 SI) which supports the presence of magnetite, and G1 with Km< 10-4 SI (mean: 97.0 x 10-6 SI). In M, Km values are homogeneous with a mean of 620.9 x 10-6 SI. The magnetic anisotropy (P%) and the ellipsoid shape (T) were only determined in granites. The mean values of P% are 6.2% and 3.1% in G0 and G1, respectively. T shows the strongest oblate ellipsoids in central G1 (mean: 0.365) and slightly oblate in G0 (mean: 0.099). The magnetic foliations are subvertical ENE-WSW-striking in G0 and G1. Magnetic lineations are subvertical in G0 and moderately plunge to the SE in G1.The saturation IRM (SIRM) mean values are 9.345 A/m in G0, 0.027 A/m in G1 and 2.634 A/m in M. In G0 and M, the IRM acquisition curves show saturation between 0.3 and 0.4 T, followed by a small increase in increasing fields, suggesting that the main carrier of remanence is low magnetite or Ti-magnetite. In G1, the acquisition curves demonstrate paramagnetic and antiferromagnetic fractions, but a small magnetite fraction can also be present. SIRM/K have mean values of 7.119 kA/m, 0.298 kA/m and 3.425 kA/m for Go, G1 and M, respectively. The AMS and SIRM data support that G0 and G1 have a distinct magnetic behaviour. G0 is controlled by a ferrimagnetic fraction. G1, with Km< 10-4 SI, shows a paramagnetic behaviour due to ferromagnesian minerals, such as biotite and ilmenite. In M, Km is typical of gabbros and granodiorites and is due to the high contents of ferromagnesian minerals. The magnetic behaviours of G0 and G1 suggest different redox conditions in the magma genesis. Magnetic anisotropy is higher in G0 due to the presence of magnetite, but microscope observations also show signs of a post-magmatic deformation in G0. Although magnetic foliations are subvertical ENE-WSW-striking in both granites, magnetic lineations are different. The differences reflect distinct redox processes at magmatic sources and different emplacement mechanisms of M, G0 and G1

Two-scalar-field model for the interaction of dark energy and dark matter

In this paper, we study the effects of an interaction between dark matter and dark energy through a two scalar field model with a potential $V(\phi,\chi)=e^{-\lambda\phi}P(\phi,\chi)$, where $P(\phi,\chi)$ is a polynomial. We show that the cosmic expansion dynamics of the Universe is reproduced for a large range of the bare mass of the dark matter field and that there exist solutions with transient accelerated expansion. A modification in the exponential behavior of the potential is studied, with important physical implications, including the possibility of more realistic transient acceleration solutions.Comment: Version to match the one published in Physical Review D, 8 pages, 11 figure

A continuous-stress tetrahedron for finite strain problems

A finite-strain tetrahedron with continuous stresses is proposed and analyzed. The complete stress tensor is now a nodal tensor degree-of-freedom, in addition to displacement. Specifically, stress conjugate to the relative Green-Lagrange strain is used within the framework of the Hellinger-Reissner variational principle. This is an extension of the Dunham and Pister element to arbitrary constitutive laws and finite strain. To avoid the excessive continuity shortcoming, outer faces can have null stress vectors. The resulting formulation is related to the nonlocal approaches popularized as smoothed finite element formulations. In contrast with smoothed formulations, the interpolation and integration domain is retained. Sparsity is also identical to the classical mixed formulations. When compared with variational multiscale methods, there are no parameters. Very high accuracy is obtained for four-node tetrahedra with incompressibility and bending benchmarks being successfully solved. Although the ad-hoc factor is removed and performance is highly competitive, computational cost is high, as each tetrahedron has 36 degrees-of-freedom. Besides the inf-sup test, four benchmark examples are adopted, with exceptional results in bending and compression with finite strains

Tools for dialect syntax: the case of CORDIAL-SIN (an annotated corpus of Portuguese dialects)

This paper addresses methodological issues of concern to the study of morphosyntactic variation. While the empirical basis of dialect syntax is still a matter of elaboration, the focus will be here on the role of dialect corpora as tools for the study of linguistic variation in this particular domain. The case of CORDIAL-SIN, an annotated corpus of Portuguese dialects, will be presented along with some initial advances in Portuguese dialect syntax. Two levels of tools for the study of linguistic variation will thus be addressed here: (i) corpora as general tools for dialect syntax; and (ii) tagging and syntactic annotation within a dialect corpus as tools that ease the way how variation in morphosyntax can be studied. Section 1 introduces methodological remarks concerning the empirical ground for dialect syntax; the CORDIAL-SIN is presented in section 2; section 3 briefly illustrates how this tool has enhanced the development of Portuguese dialect syntax.info:eu-repo/semantics/publishedVersio

The reflection of partnership context on implementation and process outcomes in cross-sector social partnerships : the case of a local red cross in Portugal

In this article the research question is the following: how partnership context inherent to target-group problems and organizational flexibility of origin institutions is reflected on the implementation and process outcomes of partnerships? We studied three interventions directed towards active ageing and employment promotion on the unemployed with low qualifications, which integrated non-profit institutions, local public institutions, SME and an enterprise association. The local Red Cross was the convener. Based on case study methodology we analyzed sixteen semi-directed interviews of partners’ representatives and the documentation of each intervention. The complex nature of the problems had implications on the implementation in terms of the diverse resources and partners involved, the collaborative and organizational levels of intervention, and in feed-backs based upon joint continuous evaluation of the actions directed towards target-groups. The flexibility of origin institutions had implications on the implementation in terms of the decision autonomy of the representatives, involvement of other members of the origin institutions in the intervention, financial and human resources limitations of partner-institution, and strategic SME integration of the social values of the non-profit institutions. The interventions which focused on feminine self-employment and active ageing co-created value due to the reformulation of goals and actions, increased partner skills for mutual benefit and increased interdependence awareness. The SME involved in the feminine self-employment intervention developed new organizational skills and social responsibility evaluation

Correlation of magnetic susceptibility with 18O data in magnetite- and ilmenite-type granites from Iberian massif

The relationship between oxygen isotopic values and magnetic susceptibility composition on 11 Variscan Portuguese granites has been investigated. Whole-rock oxygen-isotope (18O ) values for Vieira do Minho (VM), Vila Pouca de Aguiar (VPA), Chaves, Castelo Branco (CB), Manteigas and Serra da Estrela (SE) granitoids, were compilated from bibliography [1,2,3,4], and 18O for Santa Eulalia Plutonic Complex (SEPC) were obtained by laser fluorination at the Stable Isotopic Laboratory of Salamanca. Magnetic susceptibility (Km) values were obtained with a Kappabridge equipment from Toulouse University and Geology Centre, Porto University [2,5,6,7,8]. In this study is shown that there is a significant inverse correlation between Km and 18O. Magnetite-type granites (Manteigas granodiorite and SEPC external facies) have Km>10-3 SI and low 18O values ranging from 8.9 to 10.3 0/00 instead those of ilmenite-type (all the other granites) have Km 10-4 SI and are 18O enriched (9.3 to 13.5 0/00). The I-type granites (VM, VPA, Chaves, Manteigas and SEPC external facies) show lower average 18O (10.2 0/00) and higher Km values (100x10-6 SI) than the S-type granites (SE and CB) with 18O = 12.6 0/00 and Km = 65x10-6 SI. Figure 1: Semi-log plot of Km (in Si units) versus 18O. This work has been financially supported by PTDC/CTEGIX/ 099447/2008 (FCT-Portugal, COMPETE/FEDER). [1] Martins et al. (in prep.) [2] Martins et al. (2009) Lithos 111, 142-155. [3] Antunes et al. (2008) Lithos 103, 445-465. [4] Neiva et al. (2009) Lithos 111, 186-202. [5] Sant’Ovaia et al. (2010) JSG 32, 1450-1465. [6] Sant’Ovaia et al. (2000) TRSE, ES 91, 123-127. [7] Sant’Ovaia et al. (2008) 33rd IGC CD. [8] Sant’Ovaia et al. (2011) Min. Mag. 75, 3, 1795