Magnetism from intermetallics and perovskite oxides

This work has been presented by RJCV to obtain his PhD degree at Fluminense Federal University, in March of 2017. We focused on the synthesis of compounds and then on their magneto-strucutral characterization; mainly due to the interplay of these physical properties. We have prepared intermetallic alloys (including Heusler alloys) and perovskite oxides (manganites and cobaltites); in bulk and nanoparticles. A thorough analysis of the influence of the morphology and crystal structure on the magnetic properties of these compounds is addressed.Comment: This is a version of the Thesis presented by RJCV at Intituto de F\'isica at Universidade Federal Fluminense, Niter\'oi-RJ Brazil in march 2017, on supervision of Dr. Mario de Souza Reis Jr. ([email protected]

Branching Deregulation and Merger Optimality

The U.S. banking industry has been characterized by intense merger activity in the absence of economies of scale and scope. We claim that the loosening of geographic constraints on U.S. banks is responsible for this consolidation process, irrespective of value-maximizing motives. We demonstrate this by putting forward a theoretical model of banking competition and studying banks’ strategic responses to geographic deregulation. We show that even in the absence of economies of scale and scope, bank mergers represent an optimal response. Also, we show that the consolidation process is characterized by merger waves and that some equilibrium mergers are not profitable per se -they yield losses- but become profitable as the waves of mergers unfold.Banking Competition, Deregulation, Mergers

Whom to Merge with? A Tale of the Spanish Banking Deregulation Process

We put forward a simple spatial competition model to study banks’ strategic responses to the Spanish asymmetric geographic deregulation. We find that once geographic deregulation process finishes, inter-regional mergers between the savings banks are optimal. We claim that the public good nature of the merging activities together with the incentives provided by the deregulation process are the driving factors behind the equilibrium merger of the savings banks. It seems that the economic crisis will finally force regional politicians to allow inter-regional caja mergers, letting the consequences of the removal of geographic barriers in the 80’s come to a fruition with a delay of thirty years.Banking Competition, Deregulation, Mergers

Hydrogen vs. Battery in the long-term operation. A comparative between energy management strategies for hybrid renewable microgrids

The growth of the world’s energy demand over recent decades in relation to energy intensity and demography is clear. At the same time, the use of renewable energy sources is pursued to address decarbonization targets, but the stochasticity of renewable energy systems produces an increasing need for management systems to supply such energy volume while guaranteeing, at the same time, the security and reliability of the microgrids. Locally distributed energy storage systems (ESS) may provide the capacity to temporarily decouple production and demand. In this sense, the most implemented ESS in local energy districts are small–medium-scale electrochemical batteries. However, hydrogen systems are viable for storing larger energy quantities thanks to its intrinsic high mass-energy density. To match generation, demand and storage, energy management systems (EMSs) become crucial. This paper compares two strategies for an energy management system based on hydrogen-priority vs. battery-priority for the operation of a hybrid renewable microgrid. The overall performance of the two mentioned strategies is compared in the long-term operation via a set of evaluation parameters defined by the unmet load, storage efficiency, operating hours and cumulative energy. The results show that the hydrogen-priority strategy allows the microgrid to be led towards island operation because it saves a higher amount of energy, while the battery-priority strategy reduces the energy efficiency in the storage round trip. The main contribution of this work lies in the demonstration that conventional EMS for microgrids’ operation based on battery-priority strategy should turn into hydrogen-priority to keep the reliability and independence of the microgrid in the long-term operation

On Chaotic Behavior of ASH Attractors

The asymptotic sectional hyperbolicity is a weak notion of hyperbolicity that extends properly the sectional-hyperbolicity and includes the Rovella attractor as a archetypal example. The main feature of this definition is the existence of arbitrarily large hyperbolic times for points outside the stable manifolds of the singularities. In this paper we will prove that any attractor associated to a $C^1$ vector field $X$ on a three-dimensional manifold satisfying this kind of hyperbolicity is rescaling-expansive and presents sensitiveness respect to initial conditions.Comment: 20 pages, 1 figur

Niemann-Pick Type C Disease Reveals a Link between Lysosomal Cholesterol and PtdIns(4,5)P2 That Regulates Neuronal Excitability.

There is increasing evidence that the lysosome is involved in the pathogenesis of a variety of neurodegenerative disorders. Thus, mechanisms that link lysosome dysfunction to the disruption of neuronal homeostasis offer opportunities to understand the molecular underpinnings of neurodegeneration and potentially identify specific therapeutic targets. Here, using a monogenic neurodegenerative disorder, NPC1 disease, we demonstrate that reduced cholesterol efflux from lysosomes aberrantly modifies neuronal firing patterns. The molecular mechanism linking alterations in lysosomal cholesterol egress to intrinsic tuning of neuronal excitability is a transcriptionally mediated upregulation of the ABCA1 transporter, whose PtdIns(4,5)P2-floppase activity decreases plasma membrane PtdIns(4,5)P2. The consequence of reduced PtdIns(4,5)P2 is a parallel decrease in a key regulator of neuronal excitability, the voltage-gated KCNQ2/3 potassium channel, which leads to hyperexcitability in NPC1 disease neurons. Thus, cholesterol efflux from lysosomes regulates PtdIns(4,5)P2 to shape the electrical and functional identity of the plasma membrane of neurons in health and disease

GLOBAL MARKET, GLOBAL STRATEGIC REFLECTION? A STRATEGIC APPROACH METHODOLOGY

The aim of this study is to analyse the internationalization strategies of Portuguese wine companies, considering their context factors, reflection style and performance. It intends to develop a review of the literature in the scope of the theories and strategies of internationalisation, complemented by systematic research within the sector, as part of business strategies. It proposes applying the methodological reference Integrated Grid for Strategic Reflection - GIRE(i), adapted to a context of international business, which structures research into two levels: a preliminary one, generic characterisation of the companies; along with a central one analysing its strategic strand. The empirical study, based on primary data (survey to the sector entrepreneurs) and on secondary documentary data, by applying multivariate statistical techniques, allowed the identification of strategic thinking styles based on the growth of a rather diverse external presence. Drawn on the qualitative (contextual and transactional) analysis it suggests guidelines for strategic action