2,376 research outputs found

    Revenue Optimization for the Ocean Grazer Wave Energy Converter through Storage Utilization

    Get PDF
    Increased penetration of renewable energy generation motivates a change of paradigm in the way power systems are structured and operated, as advocated by the smart grid concept. Accordingly, in this paper we investigate the lossless storage capabilities of the Ocean Grazer wave energy converter (WEC), which could facilitate the aforementioned paradigm shift. This specific WEC exhibits both adaptability with respect to the incoming waves and significant lossless storage capabilities. We propose a model predictive control (MPC) strategy based on a lumped dynamical model in order to mitigate power imbalances in the power grid and maximize the revenue of the WEC. Furthermore, we illustrate that the proposed strategy exploits the WEC energy storage capabilities and we show the economic benefits it brings. Lastly, the proposed strategy is compared with a heuristic approach and a setting without storage

    Deep-water oyster cliffs at La Chapelle Bank (Celtic Margin)

    Get PDF
    The maiden voyage of Ghent University’s ROV GENESIS on-board R/V Belgica (13-20 June 2006) has succeeded in contributing to several objectives of the EU-projects HERMES and EURODOM, as well as of the ESF Euromargins project MoundForce. After several trials in the Bay of Douarnenez, GENESIS made its first deep-water survey dives off the Banc de la Chapelle, on the Celtic margin, down to 700 m. The French canyon system near the Banc de la Chapelle offered a perfect location for rigorous trials of GENESIS: reported cold-water coral finds, rugged topography and hydrodynamics in a setting linking the shelf seas to the deep marine realm. The area was first surveyed using R/V Belgica’s multibeam echosounder, imaging deep canyons and thalweg channels between prominent spurs where corals had been reported. High resolution seismic sparker lines provided a geological context and linked in to the existing seismostratigraphy.Two successful dives revealed a sandy-muddy seabed with curious bedforms and erosion exposing consolidated sedimentary sequences, often cut by vertical cliffs up to 10m high. At the base of the cliffs, fallen blocks provided settlement sites for sessile organisms whilst the cliffs and protruding banks revealed dense communities of unidentified giant ostreidae (probably Neopycnodonte sp) forming 3D assemblage with occasional cold-water coral colonies (Lophelia pertusa). Though deep-water ‘oyster banks’ of Neopyncodonte cochlear had already been reported in the Bay of Biscay by ..Le Danois (1948) based on dredges, these dramatic seascapes had remained largely hidden to the human eye up to now

    Phase transitions for PP-adic Potts model on the Cayley tree of order three

    Full text link
    In the present paper, we study a phase transition problem for the qq-state pp-adic Potts model over the Cayley tree of order three. We consider a more general notion of pp-adic Gibbs measure which depends on parameter \rho\in\bq_p. Such a measure is called {\it generalized pp-adic quasi Gibbs measure}. When ρ\rho equals to pp-adic exponent, then it coincides with the pp-adic Gibbs measure. When ρ=p\rho=p, then it coincides with pp-adic quasi Gibbs measure. Therefore, we investigate two regimes with respect to the value of ρp|\rho|_p. Namely, in the first regime, one takes ρ=expp(J)\rho=\exp_p(J) for some J\in\bq_p, in the second one ρp<1|\rho|_p<1. In each regime, we first find conditions for the existence of generalized pp-adic quasi Gibbs measures. Furthermore, in the first regime, we establish the existence of the phase transition under some conditions. In the second regime, when ˚p,qpp2|\r|_p,|q|_p\leq p^{-2} we prove the existence of a quasi phase transition. It turns out that if ˚p<q1p2<1|\r|_p<|q-1|_p^2<1 and \sqrt{-3}\in\bq_p, then one finds the existence of the strong phase transition.Comment: 27 page

    Groups of diffeomorphisms and geometric loops of manifolds over ultra-normed fields

    Full text link
    The article is devoted to the investigation of groups of diffeomorphisms and loops of manifolds over ultra-metric fields of zero and positive characteristics. Different types of topologies are considered on groups of loops and diffeomorphisms relative to which they are generalized Lie groups or topological groups. Among such topologies pairwise incomparable are found as well. Topological perfectness of the diffeomorphism group relative to certain topologies is studied. There are proved theorems about projective limit decompositions of these groups and their compactifications for compact manifolds. Moreover, an existence of one-parameter local subgroups of diffeomorphism groups is investigated.Comment: Some corrections excluding misprints in the article were mad
    corecore