Search results for "Alder"
showing 10 items of 273 documents
"NO HAY VIRTUD SIN EXPERIENCIA": PRETENDIENTES INESPERADOS Y DAMAS AL ACECHO EN LA TRAGEDIA DEL SIGLO DE ORO // NÃO HÁ VIRTUDE SEM EXPERIÊNCIA: PRETE…
2016
RECEBIDO EM 31 AGO 2016 APROVADO EM 01 OUT 2016 A figura do antagonista e chave em qualquer conflito tragico, dado que representa a oposicao a ordem estabelecida, a personagem que consegue develar o lado obscuro do heroi. Um dos conflitos prediletos da tragedia espanhola do seculo XVII e aquele em que se enfrentam o amor e o honor , o passado e o presente, o dever e o desejo, e pode ser articulado por meio de uma estrutura tipificada: um casamento concertado cuja aparente harmonia ver-se-a irremissivelmente alterada pela chegada inesperada de um antigo pretendente da esposa que reclama direitos sentimentais e cuja atuacao comprometedora, unida aos erros da protagonista, levara o marido - in…
Recovery of time-dependent coefficients from boundary data for hyperbolic equations
2019
We study uniqueness of the recovery of a time-dependent magnetic vector-valued potential and an electric scalar-valued potential on a Riemannian manifold from the knowledge of the Dirichlet to Neumann map of a hyperbolic equation. The Cauchy data is observed on time-like parts of the space-time boundary and uniqueness is proved up to the natural gauge for the problem. The proof is based on Gaussian beams and inversion of the light ray transform on Lorentzian manifolds under the assumptions that the Lorentzian manifold is a product of a Riemannian manifold with a time interval and that the geodesic ray transform is invertible on the Riemannian manifold.
Contrasting Styles of Inter-Caldera Volcanism in a Peralkaline System: Case Studies from Pantelleria (Sicily Channel, Italy)
2022
The recent (<190 ka) volcanic history of Pantelleria is characterized by the eruption of nine peralkaline ignimbrites, ranging in composition from comenditic trachyte to comendite to pantellerite. The ~46 ka Green Tuff (GT) was the last of these ignimbrites, which was followed by many effusive and explosive low-volume eruptions of pantellerite from vents within the caldera moat and along the caldera rim. Although recent studies have shed additional light on the age, petrochemistry, and volcanology of the older ignimbrites, there is very little knowledge of magmatism that occurred between these older ignimbrites, primarily due to the very scarce exposures. In this paper, we present new fi…
Evidences of magma mixing in the "Daly gap" of the alkaline suites: a case study from the enclaves of Pantelleria (Italy)
2006
The island of Pantelleria consists of trachytes, pantellerites and minor mildly alkaline basalts. Rocks of intermediate composition (falling in the so-called ‘Daly Gap’) such as mugearites, benmoreites and mafic trachytes occur only in the form of enclaves in trachytes and pantellerites inside the main caldera of the island (Caldera ‘Cinque Denti’), which collapsed during the ‘Green Tuff ’ ignimbrite eruption at 50 ka. The enclaves include volcanic, subvolcanic and intrusive rock types. The enclaves in host trachyte contain traces of glass; devitrified glass occurs within enclaves in host pantellerites. Minerals in the enclaves show regular compositional variations with whole-rock silica co…
Gas Leakage From Shallow Ponding Magma and Trapdoor Faulting at Sierra Negra Volcano (Isabela Island, Galápagos)
2022
We report on new volcanic gas composition results acquired in October 2017 at Minas de Azufre, a persistent fumarolic field topping the resurgent Sierra Negra caldera, in the Galápagos archipelago. Our results indicate that the Minas de Azufre fumaroles are moderately hydrous (52–64 mol.% H2O) and rich in CO2 (35–46 mol.%), with total sulfur (ST) being 21–35 times less abundant than CO2. SO2, the most abundant S species, is released at an average rate of 19 ± 9 tons/day. Using a volatile saturation model that provides the composition of magmatic gases at equilibrium with western Galápagos basaltic melt (48 wt. % SiO2) in the 400–0.1 MPa pressure range, we infer that Minas de Azufre fumaroli…
The structure of a hydrothermal system from an integrated geochemical, geophysical, and geological approach: The Ischia Island case study
2011
The complexity of volcano-hosted hydrothermal systems is such that thorough characterization requires extensive and interdisciplinary work. We use here an integrated multidisciplinary approach, combining geological investigations with hydrogeochemical and soil degassing prospecting, and resistivity surveys, to provide a comprehensive characterization of the shallow structure of the southwestern Ischia's hydrothermal system. We show that the investigated area is characterized by a structural setting that, although very complex, can be schematized in three sectors, namely, the extra caldera sector (ECS), caldera floor sector (CFS), and resurgent caldera sector (RCS). This contrasted structura…
Alnus glutinosa Riparian Woodlands of Italy and Corsica: Phytosociological Classification and Floristic Diversity
2022
A comparative analysis of the riparian vegetation dominated by Alnus glutinosa in Italy and Tyrrhenian islands, based on literature data and unpublished relevés, is presented. A total of 456 phytosociological relevés were processed. For the definition of plant communities and alliances, hierarchical clustering was performed by using Bray-Curtis coefficient and Detrended Correspondence Analysis ordination methods. Identification of diagnostic species of the vegetation units was performed by means of the phi fidelity index. Quantum GIS software version 3.6 was used for the interpolation of the bioclimatic variables and A. glutinosa communities. Overall, a total of 18 A. glutinos…
Resurgent uplift at large calderas and relationship to caldera-forming faults and the magma reservoir: new insights from the Neapolitan Yellow Tuff c…
2021
&lt;p&gt;Resurgence uplift is the rising of the caldera floor, mainly due to pressure or volume changes in the magma reservoir. Identifying resurgence structures and understanding their relationship to the magmatic reservoir is challenging. We investigate the resurgence structures of the Neapolitan Yellow Tuff (NYT) caldera (Italy) by integrating bathymetric data, high-resolution seismic profiles and Differential Synthetic-Aperture Radar Interferometry data. Our results show that the resurgent area is manifested as 1) a central dome constituted by two main blocks bounded by NNE-SSW trending faults, 2) an apical graben developed on top of the most uplifted block, 3) a peripheral zone…
DEEP EUTECTIC SOLVENTS E LIQUIDI IONICI: SOLVENTI PER LO SVILUPPO DI PROCESSI ECO-COMPATIBILI
2020
L’obiettivo di questi tre anni di Dottorato è stato lo studio e l’utilizzo nuovi solventi di reazione in grado di sostituire i solventi organici classici. In particolare sono stati studiati i Deep Eutectic Solvent (DES) e le miscele di Liquidi Ionici (IL). I DES sono stati utilizzati come solventi per lo studio di reazioni organiche, usate per la formazione di nuovi legami C-C. Nello specifico sono state studiate la reazione di Diels-Alder, e diverse reazioni di coupling C-C catalizzate da Pd. In seguito, i DES sono stati utilizzati per la formazione di nuovi gel supramolecolari, chiamati eutectogel. Questi gel sono stati formati usando come gelator amminoacidi naturali, consentendo quindi …
MITO Y HERMENÉUTICA EN LAS COMEDIAS PALACIEGAS DE CALDERÓN
2014
Este trabajo pretende definir una «fábula» según la reelaboración mitológica de Calderón, hecha de estereotipos detectables con particular constancia en el repertorio mitológico del poeta: una especie de esquema supeditado a todas las variantes de los mitos en cuestión, y por lo tanto un mapa soportado por un personal planteamiento hermenéutico, coincidente con una poética de autor. A través de un reconocimiento del corpus completo de las comedias mitológicas calderonianas, hemos enucleado los «mitologemas» recurrentes. Por «mitologemas» se entienden en la semiótica textuallos topoi mitológicos —estereotipos de acción, situación, objetos, lugares, actantes— que se repiten con insistencia ta…