• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 349
  • 306
  • 71
  • 25
  • 22
  • 8
  • 4
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • Tagged with
  • 797
  • 181
  • 162
  • 140
  • 131
  • 127
  • 126
  • 122
  • 111
  • 108
  • 99
  • 98
  • 92
  • 91
  • 91
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
211

La città di Trento tra Tardo Antico e Alto Medio Evo: la genesi della città medievale e lo spazio del sacro. / The ancient city of Trento between the Late Antiquity and the Early Middle Ages: the birth of the medieval city and the space of the sacred.

Baroncioni, Andrea <1976> 04 July 2012 (has links)
Lo scavo della chiesa di Santa MAria Maggiore ha permesso di acquisire nuove importanti informazioni sulla storia della città di Trento, sulla città tardo antica e sul processo di cristianizzazione. Il primo impianto ecclesiastico, datato a dopo la metà del V d. C. secolo, sorge su un precedente impianto termale realizzato intorno al II secolo d. C. ed appare caratterizzato da un forte carattere monumentale. La chiesa, a tre navate, presentava un presbiterio rialzato decorato in una prima fase da un opus sectile poi sostituito nel VI secolo da un mosaico policromo. Sono state rinvenute inoltre, parti consistenti della decorazione architettonica di fine VIII secolo pertinente questo stesso impianto che non subirà importanti modifiche fino alla realizzazione del successivo edificio di culto medievale, meno esteso e dai caratteri decisamente meno monumentali, caratterizzato dalla presenza di un esteso campo cimiteriale rinvenuto a nord della chiesa. A questo impianto ne succede un terzo, probabilmente a due navate, e dalla ricca decorazione pittorica demolito in età tardo rinascimentale per la realizzazione della chiesa attuale. / The excavation of the church of Santa Maria Maggiore allowed us to gain important information on the history of the city of Trento during the Late Antiquity and the process of Christianization. The first church, of the second half of Vth century AD, stands on a previous thermal structure built around the IInd century AD and is characterized by a strong monumental character. The church, with three naves, presented a raised presbytery, decorated (during the first phase) with an opus sectile then replaced in the VIth century by a polychrome mosaic. Were also found major parts of the architectural decoration of late VIIIth century, belonging to this same system, which won't be significantly modified until the completion of the subsequent medieval religious building, much less extensive and with less monumental aspect, characterized by the presence of an extensive cemetery found at north of the church. The third structural phase, organized in two naves, had rich fresco decorations, and was demolished in the Late Renaissance to build the present church.
212

The bursting behavior of gas slugs: laboratory and analytical insights into Strombolian volcanic eruptions.

Del Bello, Elisabetta <1982> 16 March 2012 (has links)
The aim of this thesis is to study how explosive behavior and geophysical signals in a volcanic conduit are related to the development of overpressure in slug-driven eruptions. A first suite of laboratory experiments of gas slugs ascending in analogue conduits was performed. Slugs ascended into a range of analogue liquids and conduit diameters to allow proper scaling to the natural volcanoes. The geometrical variation of the slug in response to the explored variables was parameterised. Volume of gas slug and rheology of the liquid phase revealed the key parameters in controlling slug overpressure at bursting. Founded on these results, a theoretical model to calculate burst overpressure for slug-driven eruptions was developed. The dimensionless approach adopted allowed to apply the model to predict bursting pressure of slugs at Stromboli. Comparison of predicted values with measured data from Stromboli volcano showed that the model can explain the entire spectrum of observed eruptive styles at Stromboli – from low-energy puffing, through normal Strombolian eruptions, up to paroxysmal explosions – as manifestations of a single underlying physical process. Finally, another suite of laboratory experiments was performed to observe oscillatory pressure and forces variations generated during the expansion and bursting of gas slugs ascending in a conduit. Two end-member boundary conditions were imposed at the base of the pipe, simulating slug ascent in closed base (zero magma flux) and open base (constant flux) conduit. At the top of the pipe, a range of boundary conditions that are relevant at a volcanic vent were imposed, going from open to plugged vent. The results obtained illustrate that a change in boundary conditions in the conduit concur to affect the dynamic of slug expansion and burst: an upward flux at the base of the conduit attenuates the magnitude of the pressure transients, while a rheological stiffening in the top-most region of conduit changes dramatically the magnitude of the observed pressure transients, favoring a sudden, and more energetic pressure release into the overlying atmosphere. Finally, a discussion on the implication of changing boundary on the oscillatory processes generated at the volcanic scale is also given.
213

Integrating new and traditional approaches for the estimate of slip-rates of active faults: examples from the Mw 6.3, 2009 L’Aquila earthquake area, Central Italy

Civico, Riccardo <1980> 28 March 2012 (has links)
This thesis is based on the integration of traditional and innovative approaches aimed at improving the normal faults seimogenic identification and characterization, focusing mainly on slip-rate estimate as a measure of the fault activity. The L’Aquila Mw 6.3 April 6, 2009 earthquake causative fault, namely the Paganica - San Demetrio fault system (PSDFS), was used as a test site. We developed a multidisciplinary and scale‐based strategy consisting of paleoseismological investigations, detailed geomorphological and geological field studies, as well as shallow geophysical imaging and an innovative application of physical properties measurements. We produced a detailed geomorphological and geological map of the PSDFS, defining its tectonic style, arrangement, kinematics, extent, geometry and internal complexities. The PSDFS is a 19 km-long tectonic structure, characterized by a complex structural setting and arranged in two main sectors: the Paganica sector to the NW, characterized by a narrow deformation zone, and the San Demetrio sector to SE, where the strain is accommodated by several tectonic structures, exhuming and dissecting a wide Quaternary basin, suggesting the occurrence of strain migration through time. The integration of all the fault displacement data and age constraints (radiocarbon dating, optically stimulated luminescence (OSL) and tephrochronology) helped in calculating an average Quaternary slip-rate representative for the PSDFS of 0.27 - 0.48 mm/yr. On the basis of its length (ca. 20 km) and slip per event (up to 0.8 m) we also estimated a max expected Magnitude of 6.3-6.8 for this fault. All these topics have a significant implication in terms of surface faulting hazard in the area and may contribute also to the understanding of the PSDFS seismic behavior and of the local seismic hazard.
214

"Sleeping Princess" (1921) e "Baiser de la Fée" (1928): lesina e punteruolo di Stravinskij sulle musiche di Čajkovskij. / "Sleeping Princess" (1921) and "Fairy’s Kiss" (1928): Stravinsky’s creative process on Tchaikovsky’s music.

Corazza, Elia Andrea <1979> 18 July 2012 (has links)
Igor Stravinskij (1882-1971) utilizzò di sovente fonti preesistenti come parte integrante del proprio artigianato compositivo. In questa tesi dottorale ho studiato il processo creativo di Stravinskij negli anni Venti sulle musiche di Pëtr Il'ič Čajkovskij (1840-1893). Nella prima parte della dissertazione ho indagato la Sleeping Princess (1921) e il successivo Mariage d’Aurore (1922-1929), entrambi allestiti dai Ballets russes di Sergej Djagilev (1872-1929). Dopo aver localizzato e contestualizzato le fonti manoscritte e i materiali d’uso, ho ricostruito le ri-orchestrazioni effettuate da Stravinskij della Danse russe (Coda del Pas de deux n. 28) e del Presto del Finale (n. 30), che erano a tutt’oggi inedite. La ricerca sulla Sleeping Princess si è rivelata fondamentale per la conseguente analisi del Baiser de la Fée (1928, Ballets de Mme Ida Rubinstein), balletto basato su pezzi pianistici e romanze per voce e pianoforte di Čajkovskij. Grazie allo studio dello Skizzenbuch VIII, della partitura pianistica manoscritta e di tutte le fonti rinvenute, ho gettato ulteriore luce sul processo compositivo di Stravinskij sulle fonti čajkovskiane. Ho rinvenuto nuove appropriazioni che finora non erano note. / The use of preexisting materials is a well-documented idiosyncrasy of the compositional craftsmanship of Igor Stravinsky (1882-1971). In this dissertation I studied Stravinsky’s creative process in his Neoclassic period in relation to the music of Pyotr Il’yich Tchaikovsky (1840-1893). In the first part of the thesis I investigated the Sleeping Princess (1921) and the consequent Mariage d’Aurore (1922-1929), both produced by Sergey Diaghilev’s Ballets Russes. Comparing piano reductions to manuscript sources, I located and edited Stravinsky’s missing orchestrations of Danse Russe (Coda of the Pas de deux n. 28) and his adaptation of the Presto in the Finale (n. 30). My research on the Sleeping Princess has been fundamental to the analysis of the Fairy’s Kiss (1928, Ballets de Mme Ida Rubinstein). This ballet was composed by Stravinsky and based on Tchaikovsky’s piano pieces and romances for voice and piano. The study of the Skizzenbuch VIII, of the manuscript piano score and of all relevant items allowed me to shed further light on Stravinsky’s creative process using Tchaikovsky sources. I discovered new appropriations that were still undocumented both in the Stravinsky’s autobiographical writings and in the musicological literature.
215

Colombarone (PU). Scavo del Palatium e della Basilica di San Cristoforo ad Aquilam

Tassinari, Cristian <1975> 15 June 2007 (has links)
No description available.
216

Proof theory of quantified modal logics

Orlandelli, Eugenio <1981> 28 May 2014 (has links)
We introduce labelled sequent calculi for indexed modal logics. We prove that the structural rules of weakening and contraction are height-preserving admissible, that all rules are invertible, and that cut is admissible. Then we prove that each calculus introduced is sound and complete with respect to the appropriate class of transition frames.
217

Toward a Magnitude Scale for Low Frequency Seismicity The LP energy for Campi Flegrei caldera

Borgna, Irene <1982> 07 May 2014 (has links)
The energy released during a seismic crisis in volcanic areas is strictly related to the physical processes in the volcanic structure. In particular Long Period seismicity, that seems to be related to the oscillation of a fluid-filled crack (Chouet , 1996, Chouet, 2003, McNutt, 2005), can precedes or accompanies an eruption. The present doctoral thesis is focused on the study of the LP seismicity recorded in the Campi Flegrei volcano (Campania, Italy) during the October 2006 crisis. Campi Flegrei Caldera is an active caldera; the combination of an active magmatic system and a dense populated area make the Campi Flegrei a critical volcano. The source dynamic of LP seismicity is thought to be very different from the other kind of seismicity ( Tectonic or Volcano Tectonic): it’s characterized by a time sustained source and a low content in frequency. This features implies that the duration–magnitude, that is commonly used for VT events and sometimes for LPs as well, is unadapted for LP magnitude evaluation. The main goal of this doctoral work was to develop a method for the determination of the magnitude for the LP seismicity; it’s based on the comparison of the energy of VT event and LP event, linking the energy to the VT moment magnitude. So the magnitude of the LP event would be the moment magnitude of a VT event with the same energy of the LP. We applied this method to the LP data-set recorded at Campi Flegrei caldera in 2006, to an LP data-set of Colima volcano recorded in 2005 – 2006 and for an event recorded at Etna volcano. Experimenting this method to lots of waveforms recorded at different volcanoes we tested its easy applicability and consequently its usefulness in the routinely and in the quasi-real time work of a volcanological observatory.
218

Seismic tomographic full-waveform inversion for the Vrancea sinking lithosphere structure using the adjoint method.

Baron, Julie <1987> 07 May 2014 (has links)
The Vrancea region, at the south-eastern bend of the Carpathian Mountains in Romania, represents one of the most puzzling seismically active zones of Europe. Beside some shallow seismicity spread across the whole Romanian territory, Vrancea is the place of an intense seismicity with the presence of a cluster of intermediate-depth foci placed in a narrow nearly vertical volume. Although large-scale mantle seismic tomographic studies have revealed the presence of a narrow, almost vertical, high-velocity body in the upper mantle, the nature and the geodynamic of this deep intra-continental seismicity is still questioned. High-resolution seismic tomography could help to reveal more details in the subcrustal structure of Vrancea. Recent developments in computational seismology as well as the availability of parallel computing now allow to potentially retrieve more information out of seismic waveforms and to reach such high-resolution models. This study was aimed to evaluate the application of a full waveform inversion tomography at regional scale for the Vrancea lithosphere using data from the 1999 six months temporary local network CALIXTO. Starting from a detailed 3D Vp, Vs and density model, built on classical travel-time tomography together with gravity data, I evaluated the improvements obtained with the full waveform inversion approach. The latter proved to be highly problem dependent and highly computational expensive. The model retrieved after the first two iterations does not show large variations with respect to the initial model but remains in agreement with previous tomographic models. It presents a well-defined downgoing slab shape high velocity anomaly, composed of a N-S horizontal anomaly in the depths between 40 and 70km linked to a nearly vertical NE-SW anomaly from 70 to 180km.
219

Early Warning For Large Earthquakes: Observations, Models and Real-Time Data Analysis

Colombelli, Simona <1986> 07 May 2014 (has links)
This thesis is a collection of works focused on the topic of Earthquake Early Warning, with a special attention to large magnitude events. The topic is addressed from different points of view and the structure of the thesis reflects the variety of the aspects which have been analyzed. The first part is dedicated to the giant, 2011 Tohoku-Oki earthquake. The main features of the rupture process are first discussed. The earthquake is then used as a case study to test the feasibility Early Warning methodologies for very large events. Limitations of the standard approaches for large events arise in this chapter. The difficulties are related to the real-time magnitude estimate from the first few seconds of recorded signal. An evolutionary strategy for the real-time magnitude estimate is proposed and applied to the single Tohoku-Oki earthquake. In the second part of the thesis a larger number of earthquakes is analyzed, including small, moderate and large events. Starting from the measurement of two Early Warning parameters, the behavior of small and large earthquakes in the initial portion of recorded signals is investigated. The aim is to understand whether small and large earthquakes can be distinguished from the initial stage of their rupture process. A physical model and a plausible interpretation to justify the observations are proposed. The third part of the thesis is focused on practical, real-time approaches for the rapid identification of the potentially damaged zone during a seismic event. Two different approaches for the rapid prediction of the damage area are proposed and tested. The first one is a threshold-based method which uses traditional seismic data. Then an innovative approach using continuous, GPS data is explored. Both strategies improve the prediction of large scale effects of strong earthquakes.
220

L'apprendistato e il debutto operistico di Sergej Rachmaninov / Sergej Rachmaninov's apprenticeship and operatic debut

Doti, Jacopo <1984> 23 June 2014 (has links)
All’ascolto dell’incompiuto Matrimonio di Musorgskij, Borodin aveva sentenziato lapidariamente: «une chose manquée». Uguale commento viene riservato tuttora alla produzione operistica di Sergej Rachmaninov. In questo caso però non ci troviamo di fronte a un teatro rivoluzionario che si trova costretto a fare un passo indietro rispetto ai principi programmatici di cui si vuol far portatore, bensì a un potenziale inespresso, a un profilo drammaturgico mai giunto a piena maturazione. L’evidente eterogeneità della produzione operistica lasciataci in eredità dal compositore non permette infatti di determinarne con chiarezza le ‘linee guida’ e ne rende problematica la collocazione nel contesto musicale a lui coevo. Scopo della presente dissertazione è indagare l’apprendistato e il debutto operistico del compositore russo attraverso l’analisi di materiale documentario, testi letterari, partiture nonché delle fonti critiche in lingua russa, difficilmente accessibili per lo studioso italiano. Il cuore dell’elaborato è un’analisi dettagliata di Aleko, un atto unico presentato nel 1892 dal compositore come prova finale al corso di ‘Libera composizione’ del Conservatorio di Mosca. L’opera viene considerata nel suo complesso come organismo drammatico-musicale autonomo (rapporto fonte/libretto, articolazione interna, sistema delle forme, costellazione dei personaggi, distribuzione delle voci, ecc.), ma inquadrata al contempo nel più ampio contesto del teatro musicale coevo (recezione critica sia da parte della pubblicistica coeva sia da parte della storiografia musicale). Viene fornita in appendice un’edizione del libretto con traduzione a fronte. Incorniciano l’analisi dell’opera un capitolo in cui si offre una rilettura estetica del ‘caso Rachmaninov’ e un aperçu sulla produzione operistica matura del compositore, alla luce delle riflessioni proposte nel corso della dissertazione. / «Une chose manqueé»: that’s what Borodin said, after hearing The Marriage, an unfinished opera by Mousorgsky. A similar comment may be expressed regarding Rachmaniov’s operatic legacy. Though, in this case we are facing a different kind of problem: the composer’s output is not an experimental cul-de-sac, but a tantalizing torso, which «one cannot contemplate without as sense of loss», as Richard Taruskin puts it. The present thesis aims at investigating Rachmaninov’s early operatic production through primary sources (literary texts, scores, letters, memoirs) and critical studies. The core of this dissertation is a thorough analysis of the one-act opera Aleko, presented by the composer as a graduating work at the Moscow Conservatory. The opera is analyzed in its poetic, dramatic, theatrical and morphological structures. Attention is paid also to the critical reception of the opera thorough an examination of contemporary reviews and recent secondary sources. A critical edition of the libretto with an Italian translation is supplied as well. The framework of the analysis consists in two different chapters: the first one is about Rachmaninov’s reception as a composer, the second one consists in an aperçu of the composer’s later operatic career.

Page generated in 0.0481 seconds