Stable oxygen isotope and Mg/Ca data of Globigerinoides ruber white, water stable oxygen isotope data, SST and MAT records of sediment core GeoB6211-2

During Termination 1, millennial-scale weakening events of the Atlantic meridional overturning circulation (AMOC) supposedly produced major changes in sea surface temperatures (SSTs) of the western South Atlantic, and in mean air temperatures (MATs) over southeastern South America. It has been suggested, for instance, that the Brazil Current (BC) would strengthen (weaken) and the North Brazil Current (NBC) would weaken (strengthen) during slowdown (speed-up) events of the AMOC. This anti-phase pattern was claimed to be a necessary response to the decreased North Atlantic heat piracy during periods of weak AMOC. However, the thermal evolution of the western South Atlantic and the adjacent continent is so far largely unknown. Here we address this issue, presenting high-temporal-resolution SST and MAT records from the BC and southeastern South America, respectively. We identify a warming in the western South Atlantic during Heinrich Stadial 1 (HS1), which is followed first by a drop and then by increasing temperatures during the Bølling-Allerød, in phase with an existing SST record from the NBC. Additionally, a similar SST evolution is shown by a southernmost eastern South Atlantic record, suggesting a South Atlantic-wide pattern in SST evolution during most of Termination 1. Over southeastern South America, our MAT record shows a two-step increase during Termination 1, synchronous with atmospheric CO2 rise (i.e., during the second half of HS1 and during the Younger Dryas), and lagging abrupt SST changes by several thousand years. This delay corroborates the notion that the long duration of HS1 was fundamental in driving the Earth out of the last glacial.

Experiments with two Approaches for Tracking Drifting Concepts

This paper addresses the task of learning classifiers from streams of labelled data. In this case we can face the problem that the underlying concepts can change over time. The paper studies two mechanisms developed for dealing with changing concepts. Both are based on the time window idea. The first one forgets gradually, by assigning to the examples weight that gradually decreases over time. The second one uses a statistical test to detect changes in concept and then optimizes the size of the time window, aiming to maximise the classification accuracy on the new examples. Both methods are general in nature and can be used with any learning algorithm. The objectives of the conducted experiments were to compare the mechanisms and explore whether they can be combined to achieve a synergetic e ect. Results from experiments with three basic learning algorithms (kNN, ID3 and NBC) using four datasets are reported and discussed.

Investigative journalism in Mexico: between ideals and realities. The case of Morelia

The aim of this paper is to analyse the state of the investigative journalism in Mexico, especially the one that is practiced at the local level in the provinces. That is, this research is based upon a case study conducted in Morelia, the capital city of the state of Michoacán. The empirical evidence will show that there is an evident divergence regarding the practice of the investigative journalism: on the one hand, journalists are aware of what this concept involves and they consider that they practice it on a regular basis; but, on the other, the content analysis prove otherwise. In other words, the account of what is actually printed significantly differs from the news workers’ perceptions, because the former shows a poorly developed journalistic investigation practice.

Estructura formal, textual y oral del discurso público

Estructura formal, textual y oral del discurso públicoExisten tres competencias comunicativas muy valoradas en la sociedad de la información. Primero, la búsqueda, selección y gestión de grandes cantidades de información. Segundo, la redacción de textos claros, concisos y rigurosos. Y en tercer lugar, la exposición y defensa oral de esta información en un discurso público. Tradicionalmente, los estudios de periodismo han abordado estas competencias de forma independiente. Pero actualmente, instituciones y empresas de ámbitos diferentes demandan un perfil profesional capaz de aplicarlas ante cualquier tipo de información y con objetivos diversos. Se propone un modelo integral en tres niveles estructurales basado en teorías, conceptos y estudios específicos de periodismo, oratoria, retórica… o comunicación, en los últimos años. Este modelo puede contribuir a encauzar las investigaciones de académicos y representa una herramienta de entrenamiento para profesionales.

The Weapons of Mass Destruction and the Global Security Strategy of the EU

The proliferation of weapons of mass destruction (WMD), nuclear, biological and chemical (NBC) is one of the main security challenges facing the international community today. However the new Global Security Strategy of 2016 raises the question of non-proliferation of WMD only as an incidental matter, not addressing directly the threat, a fundamental threat in the regional and global security. This is a clear step backwards for the European common security.

'Don't stop': re-thinking the function of endings in narrative television

This thesis argues that the study of narrative television has been limited by an adherence to accepted and commonplace conceptions of endings as derived from literary theory, particularly a preoccupation with the terminus of the text as the ultimate site of cohesion, structure, and meaning. Such common conceptions of endings, this thesis argues, are largely incompatible with the realities of television’s production and reception, and as a result the study of endings in television needs to be re-thought to pay attention to the specificities of the medium. In this regard, this thesis proposes a model of intra-narrative endings, islands of cohesion, structure, and meaning located within television texts, as a possible solution to the problem of endings in television. These intra-narrative endings maintain the functionality of traditional endings, whilst also allowing for the specificities of television as a narrative medium. The first two chapters set out the theoretical groundwork, first by exploring the essential characteristics of narrative television (serialisation, fragmentation, duration, repetition, and accumulation), then by exploring the unique relationship between narrative television and the forces of contingency. These chapters also introduce the concept of intra-narrative endings as a possible solution to the problems of television’s narrative structure, and the medium’s relationship to contingency. Following on from this my three case studies examine forms of television which have either been traditionally defined as particularly resistant to closure (soap opera and the US sitcom) or which have received little analysis in terms of their narrative structure (sports coverage). Each of these case studies provides contextual material on these televisual forms, situating them in terms of their narrative structure, before moving on to analyse them in terms of my concept of intra-narrative endings. In the case of soap opera, the chapter focusses on the death of the long running character Pat Butcher in the British soap EastEnders (BBC, 1985-), while my chapter on the US sitcom focusses on the varying levels of closure that can be located within the US sitcom, using Friends (NBC, 1993-2004) as a particular example. Finally, my chapter on sports coverage analyses the BBC’s coverage of the 2012 London Olympics, and focusses on the narratives surrounding cyclists Chris Hoy and Victoria Pendleton. Each of these case studies identifies their chosen events as intra-narrative endings within larger, ongoing texts, and analyses the various ways in which they operate within those wider texts. This thesis is intended to make a contribution to the emerging field of endings studies within television by shifting the understanding of endings away from a dominant literary model which overwhelmingly focusses on the terminus of the text, to a more televisually specific model which pays attention to the particular contexts of the medium’s production and reception.

Sinterização de matrizes cerâmicas à base de alumina reforçadas por carbetos a partir de precursores poliméricos

Ceramic composites produced with polymerics precursors have been studied for many years, due to the facility of obtaining a complex shape, at low temperature and reduces cost. The main objective of this work is to study the process of sintering of composites of ceramic base consisting of Al2O3 and silicates, reinforced for NbC, through the technique of processing AFCOP, as well as the influence of the addition of LZSA, ICZ and Al as materials infiltration in the physical and mechanical properties of the ceramic composite. Were produced ceramic matrix composites based SiCxOy e Al2O3 reinforced with NbC, by hidrosilylation reaction between D4Vi and D1107 mixtured with Al2O3 as inert filler, Nb and Al as reactive filler. The specimens produced were pyrolised at 1200, 1250 and 1400°C and infiltred with Al, ICZ and LZSA, respectively. Density, porosity, flexural mechanical strength and fracture surface by scanning electron microscopy were evaluated. The microstructure of the composites was investigated by X-ray diffraction to identify the presence of crystalline phases. The composites presented apparent porosity varying of 31 up to 49% and mechanical flexural strength of 14 up to 34 MPa. The infiltration process improviment of the densification and reduction of the porosity, as well as increased the values of mechanical flexural strength. The obtained phases had been identified as being Al3Nb, NbSi2, Nb5S3, Nb3Si and NbC. The samples that were submitted the infiltration process presented a layer next surface with reduced pores number in relation to the total volume

Study of the Electrochemical, Physical and Morphological Characteristics of Anode Catalysts for Perfluorosulfonic Acid (PFSA) Membrane Water Electrolysers

A number of supported and un-supported Oxygen Evolution Reaction (OER) iridium based electrocatalysts for Polymer Electrolyte Membrane Water Electrolysis (PEMWE) were synthesized using a polyol method. The electrocatalysts and the supports were characterized using a wide range of physical and electrochemical characterization methods. The effect of morphological characteristics of the OER electrocatalyst and the support on the OER activity was studied. The results of this thesis contribute to the existing research to reduce the cost of PEMWE by enhancing the utilization of precious metal for OER electrocatalysis. Iridium electrocatalysts supported on antimony tin oxide (Ir/ATO) were synthesized using the polyol method with two different heating techniques: conventional and microwave-irradiation. It was shown that the physical morphology and electrochemical properties of Ir/ATO synthesized with the two heating methods were comparable. However, the microwave irradiation method was extremely faster than the conventional heating method. Additionally, the effect of heat treatment (calcination temperature) on the morphology and OER activity of Ir/ATO synthesized electrocatalyst with the conventional polyol method. It was found that the iridium electrocatalyst synthesized with the polyol method, consisted of 1-5 nm particles, possessed an amorphous structure, and contained iridium with an average oxidation state of less than +4. Calcining the catalyst at temperatures more than 400 ºC and less than 700ºC: 1) increased the size of the iridium particles to 30 nm, 2) changed the structure of iridium particles from amorphous to crystalline, 3) increased the iridium oxidation state to +4 (IrO2), 4) reduced the electrochemically active surface area by approximately 50%, and 5) reduced the OER activity by approximately 25%; however, it had no significant effect on the physical and chemical morphology of the ATO support. Moreover, potential support metal carbides and oxides including: Tantalum Carbide (TaC), Niobium Oxide (Nb2O5), Niobium Carbide (NbC), Titanium Carbide (TiC), Tungsten Carbide (WC) and Antimony-doped Tin Oxide (ATO, Sb2O5-SnO2), were characterized, and used as support for the iridium OER electrocatalysts. TaC was found to be a promising support, and increasing its surface area by 4% improved the OER performance of the final supported catalyst by approximately 50%.

Análisis de las sanciones internacionales en el marco del tratado de no proliferación nuclear. Estudio de caso: energía atómica en Irán (2006-2015)

El presente trabajo de Grado tiene como propósito examinar la incidencia de las sancionesinternacionales en el marco del régimen de no proliferación nuclear en el caso de Irán durante el periodo 2006-2015, teniendo en cuenta factores históricos de años anteriores. Se analiza y explica cómo las sanciones internacionales pueden ser una medida persuasiva por violar ciertos artículos del Tratado de no Proliferación Nuclear. Finalmente identifica y analiza los tipos de sanciones económicas, financieras y comerciales que los Estados y el Consejo de Seguridad de las Naciones Unidas le han impuesto a Irán, así como la manera en que estas han incidido en la esfera política iraní y mundial.