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Large ignimbrites are the product of high-temperature pyroclastic density currents (PDCs) spreading over vast regions and representing one of the most devastating natural catastrophes in human history. We present a detailed examination of the ignimbrite sequence, emplaced from 10 to 80 km from the source area, of the Campanian Ignimbrite (CI) eruption, a caldera-forming Plinian event, occurred 39 ka ago, whose PDC spread over a huge area from Campi Flegrei (Italy). The CI sequence comprises seven lithofacies based upon the different sedimentary structures: 1) massive tuff or lapilli tuff; 2) diffuse-stratified tuff; 3) fines-poor lithic lapilli tuff; 4) pumice-rich lapilli tuff; 5) lenses of pumice lapilli; 6) cross-stratified tuff; 7) accretionary lapilli-bearing. Three main vertical facies association have been identified: a) fines-poor lithic lapilli to diffuse stratified or massive or inverse graded; b) cross-stratified or diffuse stratified to massive or normal- to inverse-graded; c) massive to inverse graded. These vertical variations define a dominant trend during which the concentration into the boundary layer was progressively increasing, at a fixed point, and records the increasing importance of fluid-escape condition with time. Distribution of lithofacies in the different units shows a remarkable lack of lateral variation at regional scale. This suggests an overall uniform behavior of the PDC. A temporal evolution, from traction- to granular- or fluid-escape- dominated mechanisms, records unsteadiness conditions and contrast with persistent lateral facies reflecting an overall uniform behavior of the current. Stratigraphical and chemical evidences indicate the presence of a bypass zone around the caldera.

Made available in DSpace on 2018-08-01T23:59:28Z (GMT). No. of bitstreams: 1 tese_11519_Cynthia de Barros Lima Scarpati.pdf: 129721361 bytes, checksum: 5fea7f64d9edd50a24732835b9606bdc (MD5) Previous issue date: 2017-08-08 A energia solar fotovoltaica constitui uma via fundamental para o desenvolvimento sustentável e diversificação da matriz elétrica nacional. Com o aumento nos preços dos combustíveis fósseis aliado às crescentes preocupações ambientais, a energia essa fonte surge como alternativa de energia limpa, principalmente após a formulação e implantação do Novo Modelo do Setor Elétrico Brasileiro, que estabeleceu mecanismos para aumentar a competitividade das fontes alternativas de energia frente às fontes convencionais. O Brasil é privilegiado por ser um país localizado na região intertropical, possuindo elevados níveis de insolação para o aproveitamento de energia solar durante todo o ano. Os sistemas de energia elétrica, tradicionalmente, são compostos por grandes produtores que fornecem a energia para diferentes clientes através de redes de transmissão e distribuição, sendo este modelo de transmissão conhecido como centralizado. Atualmente, a tendência é a introdução da descentralização na geração de energia elétrica, através da geração distribuída de energia. Sob essa perspectiva, este trabalho buscou apresentar as principais políticas de incentivo fiscal, regulatórias e de financiamento público para a energia solar fotovoltaica em sistemas conectados à rede elétrica no Brasil, ressaltando os aspectos econômicos e perspectivas futuras para a geração fotovoltaica centralizada e distribuída no país. Palavras-chave: Energia Solar Fotovoltaica; Políticas de Incentivo; Geração Fotovoltaica Distribuída; Leilões de Energia.

The Italian volcano, Vesuvius, erupted explosively in AD 79. Sanidine from pumice collected at Casti Amanti in Pompeii and Villa Poppea in Oplontis yielded a weighted-mean 40Ar/39Ar age of 1925±66 years in 2004 (1ó uncertainty) from incremental-heating experiments of eight aliquants of sanidine. This is the calendar age of the eruption. Our results together with the work of Renne et al. (1997) and Renne and Min (1998) demonstrate the validity of the 40Ar/39Ar method to reconstruct the recent eruptive history of young, active volcanoes.

This study on terrestrial and marine successions increases the understanding of the Late-Holocene volcanological and stratigraphical evolution of the south-western part of Campi Flegrei caldera that has been previously reported quiescent during the last 10,000 years. Stratigraphic data derived from field studies of two major tuff vents located along the coastal zone, namely Porto Miseno and Capo Miseno, clearly indicate that the Porto Miseno tuff ring slightly predates the Capo Miseno tuff cone. 40Ar/39Ar step-heating experiments, carried out on fresh sanidine separates from pumice samples, yielded a plateau age of 5090 +/- 140 yr BP for Capo Miseno and 6490 +/- 510 yr BP for Porto Miseno vent, thus confirming field observations. The volcanoclastic input derived from this recent and intense eruptive activity played a major role in the inner-shelf stratigraphic evolution of the Porto Miseno Bay deposits that have been drilled up to 40 m depth off the crater rim. The cored succession is characterised by transgressive marine deposits (mostly volcanic sand) with two intercalated peat layers (t1 and t2), dated at 3560 +/- 40 yr BP and 7815 +/- 55 yr BP (14C), respectively, interbedded with a 1-5 m thick pumice layer (tephra C). Peat layers have been chronostratigraphically correlated with two widespread paleosols onland while petrochemical analyses allowed us to correlate tephra C with the Capo Miseno tuff cone deposits. The results presented in this study imply a Late-Holocene volcanic activity that is also well preserved in the marine record in this sector of the caldera where a new chronostratigraphic reconstruction of the eruptive events is required in order to better evaluate the hazard assessment of the area.

In ischaemic stroke, thrombolytic drugs speed the recanalisation of intracerebral arteries. The effects of aspirin are not known. A trial was conducted to determine whether, separately or together, streptokinase and aspirin have clinical benefits in acute ischaemic stroke similar to those in acute myocardial infarction. 622 patients with acute ischaemic stroke within 6 hours of symptom onset were randomised with a 2x2 factorial design to (i) a 1-hour intravenous infusion of 1 . 5 MU streptokinase, (ii) 300 mg/day buffered aspirin for 10 days, (iii) both active treatments, or (iv) neither. Early results raised a question whether the trial should be continued. Streptokinase (alone or with aspirin) was associated with an excess of 10-day case fatality (odds ratio 2 . 7; 95% confidence interval 1 . 7-4 . 3; 2p

Large calderas are among the Earth's major volcanic features. They are associated with large magma reservoirs and elevated geothermal gradients. Caldera-forming eruptions result from the withdrawal and collapse of the magma chambers and produce large-volume pyroclastic deposits and later-stage deformation related to post-caldera resurgence and volcanism. Unrest episodes are not always followed by an eruption; however, every eruption is preceded by unrest. The Campi Flegrei caldera (CFc), located along the eastern Tyrrhenian coastline in southern Italy, is close to the densely populated area of Naples. It is one of the most dangerous volcanoes on Earth and represents a key example of an active, resurgent caldera. It has been traditionally interpreted as a nested caldera formed by collapses during the 100–200 km3 Campanian Ignimbrite (CI) eruption at ∼39 ka and the 40 km3 eruption of the Neapolitan Yellow Tuff (NYT) at ∼15 ka. Recent studies have suggested that the CI may instead have been fed by a fissure eruption from the Campanian Plain, north of Campi Flegrei. A MagellanPlus workshop was held in Naples, Italy, on 25–28 February 2017 to explore the potential of the CFc as target for an amphibious drilling project within the International Ocean Discovery Program (IODP) and the International Continental Drilling Program (ICDP). It was agreed that Campi Flegrei is an ideal site to investigate the mechanisms of caldera formation and associated post-caldera dynamics and to analyze the still poorly understood interplay between hydrothermal and magmatic processes. A coordinated onshore–offshore drilling strategy has been developed to reconstruct the structure and evolution of Campi Flegrei and to investigate volcanic precursors by examining (a) the succession of volcanic and hydrothermal products and related processes, (b) the inner structure of the caldera resurgence, (c) the physical, chemical, and biological characteristics of the hydrothermal system and offshore sediments, and (d) the geological expression of the phreatic and hydromagmatic eruptions, hydrothermal degassing, sedimentary structures, and other records of these phenomena. The deployment of a multiparametric in situ monitoring system at depth will enable near-real-time tracking of changes in the magma reservoir and hydrothermal system., This research has been supported by the European Consortium for Ocean Research Drilling (ECORD) through the ECORD/ICDP MagellanPlus Workshop Series Programme (grant no. 2017.2376/4/AF).

Plinian eruptions are powerful explosive volcanic events that impact large areas with cubic kilometers of magma emplaced as pyroclastic material accumulated in thick blankets around the volcanic vents. The violence of the emplacement mechanism (i.e., fallout or pyroclastic density currents, PDC) and the sudden burial of the landscape, make these types of eruptions extremely dangerous. Aiming to fully understand these phenomena, an accurate reconstruction of the physical behaviour and the historical record of a volcano is critical as starting point for the assessment of volcanic hazard. In this scenario an excellent case is the worldwide-known Plinian AD 79 Vesuvius eruption, which destroyed Roman towns with large effects preserved in different sites around the volcano. This study reports the results of a collaboration between the Archaeological Park of Pompeii and the University of Napoli Federico II to document the stratigraphic sequence and the type and extent of damage and victims buried under meters of pyroclastic material within the Pompeii and Stabiae archaeological sites. A systematic survey of well exposed outcrops along the recent excavations front allowed us to study in detail the facies variations of the different PDC stratigraphic units and how their distribution is affected even by urban structures. At Pompeii, the stratified ash PDC succession ranges in thickness from few tens of centimetres to two metres and shows considerable vertical and lateral variations in its sedimentological features. The layer associated with the most destructive impact on the Roman buildings shows down-current variation in thickness (0 to 330 cm) and texture. Where it is less than 30 cm thick, the deposit is fine-grained and thinly stratified, with few rounded pumice clasts scattered inside the matrix. Where it thickens, the lower part is rich in coarse pumice lapilli and locally shows well-developed stratifications, while the upper part shows an internal arrangement of alternating layers of fine and coarse ash, forming progressive bedforms. Upwards, the sequence is made up of a succession of plane-parallel ash layers with rare pumice lapilli clasts and diffuse accretionary lapilli. This ash sequence is interstratified with four well-sorted, thin lithic-rich layers that exhibit mantling structures of fall deposits. All PDC layers, except the lowermost, are dispersed across the entire Pompeii area, although some are locally missing as a result of the erosive action of the following PDC. At Stabiae, the ash PDC sequence is 83 cm thick. In few rooms of the Roman villa the ash deposits thicken up to 150 cm. Most of the ash layers identified at Pompeii are recognized also at Stabiae. In the upper part of the sequence a new PDC layer, never reported at Pompeii, is here documented for the first time. Damages are documented inside the more destructive ash layer and even in the upper ash layers, providing new insights about the risk assessment in distal areas.

Plinian eruptions are highly energetic events that release cubic kilometres of magma in the form of pyroclastic material (pumice, lithic clasts and ash). These products tend to accumulate near the vent with considerable thickness. The rapid burial of the territory around the eruptive centre makes these eruptions extremely dangerous. For this purpose, the renowned 79 AD Vesuvius eruption, which destroyed the ancient cities of Pompeii and Stabiae (where Pliny the Elder founds his death) located respectively 10 and 15 km from the vent, was studied in detailed. The recent excavations carried out in collaboration with the Archaeological Park of Pompeii, both in Pompeii and in the Stabian villas, have shown the complete sequence of products of the 79 AD eruption that destroyed and covered these Roman cities. The discovery of thick sequences of reworked material accumulated during previous excavations, testifies for the presence of underground tunnels dug for the Royal House of Bourbon. Fall products of the 79 AD eruptive sequence, accumulated during the main Plinian phase and the successive sustained column phases, were studied in detail to investigate their sedimentological characteristics and how these were influenced by anthropic structures. Results from field investigation show that in both archaeological sites, fall deposits consist of white and grey pumice lapilli in the lower part of the eruptive sequence (units A and B), and of thin, lithic-rich layers interstratified to ash products emplaced by pyroclastic currents, in the highest part of the pyroclastic deposit (units D, G1, G3, I). A new thin lithic-rich layer (X2) has been observed near the top of the sequence at Stabiae. The internal structure of the Plinian pumice lapilli deposit appears weakly stratified in open areas, while it is strongly stratified near steep roofs (e.g., impluvium areas), where the deposit thickens. The observed stratification is confirmed by a significant variation of sedimentological parameters with the stratigraphic height (e.g., median ranging from -3.5 to -0.1), possibly related to fluctuations in the eruptive parameters. Locally, rolling of pyroclastic clasts on sloped roofs produced a well-stratified deposit with laterally discontinuous layers and rounded clasts. Several roofing-tiles, either intact or in fragments, were recovered at various stratigraphic heights in the pumice lapilli deposit both at Pompeii and Stabiae. These tiles testify for the progressive collapse of the roofs under the increasing load of the falling lapilli clasts.

The petrological features of scoria samples and enclosed holocrystalline xenoliths from the last ~1000 years of activity of the La Soufriere volcano of St. Vincent (Lesser Antilles) are described in detail here. The products of the investigated prehistoric eruptions (pre-1440, 1440, 1580 CE) are relatively homogeneous basaltic andesites (with a paragenesis consisting of plagioclase, clinopyroxene, orthopyroxene and opaques) commonly hosting gabbroic xenoliths. Scoria samples from the historical eruptions (1718–1812 and 1902–03 CE) are mostly similar to the former in terms of whole-rock composition, mineral chemistry and types of xenoliths, but include also a mafic-rich scoria type (plagioclase + clinopyroxene + olivine) in the products of the 1902–03 eruption that is less evolved in composition and encloses ol-gabbro and ultramafic xenoliths. Both scoria types were likely affected by crystal contamination and accumulation processes, as indicated by their moderately to strongly porphyritic textures and large compositional variation of the crystal populations. Recycling of xenocryst, protocryst and/or antecryst phases, however, did not significantly modify the original magma composition, as suggested by the overall consistency of whole-rock differentiation trends with petrography, mineral chemistry, xenolith types and glass compositions (within both inclusions and the groundmass) and experimental petrology observations, crystal fractionation therefore still appearing as the main evolutionary process. Most of the gabbro and ol-gabbro xenoliths have mineral compositions in line with that of the coexisting phenocrysts and textural features consistent with an intrusive origin, i.e., representing fully-crystallised melt aliquots. Conversely, ultramafic, troctolitic and noritic xenoliths (plus some ol-gabbro) are likely representing cumulitic assemblages, i.e., mineral phases removed from the magma by crystal fractionation. The typical association of An-rich plagioclase and relatively Fo-poor olivine of the troctolite (and ol-gabbro) cumulates is ascribed to crystallisation from a hydrous (H2O ~4.5–6 wt%) high-Al2O3 basalt/basaltic andesite magma crystallising at shallow depths (~0.2 GPa, i.e., at ~7 km). On the other hand, the ultramafic cumulitic xenoliths are thought to derive from a less hydrous basalt magma stalling at deeper levels (~0.4 GPa, ~13 km). The tapping of such magma could mark a major rejuvenation event, which is the process that likely triggered the 1902–03 eruption.

The paper focuses on the instances of direct speech in the anonymous chival- ric romance Curial and Guelfa. More specifically, it analyzes, on the one hand, the encomia of the young hero Curial pronounced by the characters in their speeches, and, on the other hand, the formal and structural characteristics of two types of direct speech: speech dealing with love themes, and speech addressed by a challenger to his rival in the context of duels. Furthermore, the study examines the occurrences of the term honor in direct speeches as an expression of the au- thor’s concept of chivalry.

Large ignimbrites are the product of devastating explosive eruptions that have repeatedly impacted climate and life on global scale. The assemblage of vertical and lateral lithofacies variations within an ignimbrite sheet, its internal architecture, may help to determine how the parental pyroclastic current evolves in time and space. The 39 ka Campanian Ignimbrite eruption, vented from Campi Flegrei caldera, laid down a thick ignimbrite over an area of thousands of km2. A detailed reconstruction of the vertical and lateral variation of the seven lithofacies recognised in the ignimbrite medial sequence constrains the behaviour of this event. The pyroclastic current flowed over a wide area around Campi Flegrei without depositing (bypass zone), and inundated a huge area during most of the paroxysmal, waxing phase, emplacing a mainly incipiently- to strongly- welded ignimbrite. Following this waxing phase, the leading edge of the current retreated back towards the source as the current waned, impacting a progressively smaller area and leaving an unconsolidated ash and lapilli deposit, later lithified. Our study illustrates how large pyroclastic currents can evolve in time and space and the importance of both internal (eruptive and transport mechanisms) and external (topography, surficial water and rain) factors in governing their behaviour.

The products of explosive activity of La Soufriere volcano on the island of St Vincent over the last 1000 years are described. Dates for the different eruptions were determined using information from contemporary accounts, fieldwork and radiocarbon dating. Scoria-flow type pyroclastic density currents (PDCs) dominate the products of both the historical eruptions (1979, 1902–03, 1718/1812 CE) and prehistoric eruptions (~1580 and 1440 CE) with subordinate fallout components associated with several eruptions. Radiocarbon dating shows that these six eruptions define a crude cyclicity with repose periods ranging between 77 and ~140 years and systematically decreasing in more recent times. Two prehistoric eruptions, in ~1440 and 1580 CE respectively, both produced magmatic lapilli fallout and PDCs, and were fed by slightly more evolved magmas than the historical eruptions. The eruptions in 1902 and 1812 CE had ash-rich, possible phreatomagmatic activity at their onset. The iconic 1902–03 CE eruption generated radial distributed PDCs, which were responsible for the deaths of ~1500 people. However, only small remnants of these deposits remain and the original distribution cannot be determined from the preserved geology, which has important implications for hazard studies. Petrochemical work has shown that magmas involved in the explosive eruptions were quite narrow in compositional range, mainly comprising basaltic andesites. The 1902–03 eruption involved a late stage basaltic component in March 1903. However, activity in the last 1000 years generated notably more homogeneous magmas with a narrower range than the older eruptive periods previously reported in the literature, suggesting a significant variation in the magmatic reservoir feeding system with time.

A huge excavation project is in progress at Pompeii since the last year, it will lead to the exhibition of an excavation front of 2.5 km. In this first year of daily excavations we have observed several complete stratigraphic sequences within the town of Pompeii, recorded the exact stratigraphic positions of new victims and investigated the damages suffered by the Roman buildings. The new stratigraphic survey of the pyroclastic deposits blanketing Pompeii ruins shows significant departures from the late reconstruction of the events that occurred, inside the town, during the two main phases (pumice fallout and pyroclastic density currents) of the AD 79 Vesuvius eruption. A systematic survey of all the (ephemerally) exposed pyroclastic sequences allowed us to study in detail the distribution and lateral facies variations of the different stratigraphic units. The basal lapilli fall deposit shows a remarkable thickness variation ranging from 0 to 4.5 metres. Pronounced lateral variations are observed in the upper stratified ash deposit, emplaced by several successive pyroclastic density currents. We investigated the main ‘killing’ horizon where hundreds of victims were found. This massive to stratified unit is strongly controlled by the local urban structures. The coarse, massive and pumice-rich lower part is valley ponding; while the finer, stratified upper part drapes the buildings showing well developed progressive dunes. The presence of wall fragments, of more than 300 kg, in the middle part of this unit confirms that the associated pyroclastic current was the most devastating event during the 79 AD eruption at Pompeii.

"The Italian cancer registries network has not been sufficiently developed in the Southern regions. General practitioners (GPs) are knowledgeable about the prevalence, incidence and mortality for different types of cancer in their patient populations. The aim of this pilot study was to verify the feasibility and reliability of the characterization of cancer populations using GP databases in order to evaluate the impact of cancer in the general population of Naples. The characteristics of the cases studied have been collected by interview or electronic health record and recorded on paper or magnetic supports, appropriately conforming to the current privacy law. Databases are centralized, stored and codified on electronic data-sheets and periodically elaborated by the 'Consorzio Nazionale delle Cooperative Mediche' and 'Federico II' University. The present study was initiated on September 15, 2004. The analysed geographical area included the suburbs of 'Stella' and 'San Carlo all'Arena', situated in the historical center of Naples and corresponding to Health Care District 29 of the local health service. The analysis included 16,927 men and women (age range, 6-97 years) from the outpatient offices of 12 GPs who agreed to participate in the study. Results showed that the analysed population represents 16.3% of the general population residing in the area under study. We identified 342 (2%) patients with cancer, 143 (0.8%) of whom were men and 199 (1.2%) women (M/F ratio of 0.7). Of the 342 patients, 10 (5 men and 5 women) had a double cancer; thus, a total of 352 malignancies was characterized. Cancer prevalence was 2,020/100,000 inhabitants. This estimate is lower compared to the national prevalence (2,683/100,000 inhabitants) but higher compared to that in other southern Italian areas. Results, stratified by International Classification of Disease, ninth revision (ICD-IX), based on factors including gender and age, demonstrated that breast cancer, urogenital tumours and colorectal cancer are the most frequently occurring types of cancer identified among the inhabitants of Naples. Cancer prevalence in the historical center of Naples is in concordance with national estimates and projections and National Cancer Registries may be easily and accurately supported by GP medical databases.. . "