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Medellín, Colombia

Weber M.,Carrera 80 No 65 223 | Altenberger U.,Karl Liebknecht Str. 24 | Lopez-Martinez M.,Carretera Ensenada Tijuana No. 3918 | Tobon M.,Carrera 80 No 65 223 | And 3 more authors.
Geologica Acta | Year: 2011

The chemical composition of eclogites, found as boulders in a Tertiary conglomerate from the Guajira Peninsula, Colombia suggests that these rocks are mainly metamorphosed basaltic andesites. They are depleted in LILE elements compared to MORB, have a negative Nb-anomaly and flat to enriched REE patterns, suggesting that their protoliths evolved in a subduction related tectonic setting. They show island-arc affinities and are similar to primitive islandarc rocks described in the Caribbean. The geochemical characteristics are comparable to low-grade greenschists from the nearby Etpana Terrane, which are interpreted as part of a Cretaceous intra-oceanic arc. These data support evidence that the eclogites and the Etpana terrane rocks formed from the same volcano-sedimentary sequence. Part of this sequence was accreted onto the margin and another was incorporated into the subduction channel and metamorphosed at eclogite facies conditions. 40Ar-39Ar ages of 79.2±1.1Ma and 82.2±2.5Ma determined on white micas, separated from two eclogite samples, are interpreted to be related to the cooling of the main metamorphic event. The formation of a common volcano-sedimentary protolith and subsequent metamorphism of these units record the ongoing Late Cretaceous continental subduction of the South American margin within the Caribbean intra-oceanic arc subduction zone. This gave way to an arc-continent collision between the Caribbean and the South American plates, where this sequence was exhumed after the Campanian.

Gonzalez D.,Carrera 80 No 65 223 | Paja C.A.R.,Carrera 80 No 65 223 | Montes A.J.S.,Carrera 80 No 65 223 | Zuluaga E.I.A.,Carrera 80 No 65 223 | Carrejo C.E.,CNRS Laboratory of Analysis and Architectures of Systems
Revista Facultad de Ingenieria | Year: 2012

In grid-connected Photovoltaic (PV) applications, DC-links based on large electrolytic capacitors, which introduce reliability problems, are used to attenuate voltage oscillations caused by the sinusoidal power injection into the grid. This paper proposes the unified modeling of the complete PV system in grid-connected operation to design control strategies that mitigate the DC-link voltage oscillations as well as irradiance disturbances caused by environmental perturbations, it making feasible the use of non-electrolytic capacitors. The developed control strategies have been associated with a maximum power point tracking technique to maximize the power produced by the PV panel. Finally, the proposed solution has been validated by means of analytical expressions, simulations, and experimental results.

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