202 research outputs found
In una "crémerie" di Rue de Rivoli: per un incipit di Longhi
No full textA partire dell’incipit del Carlo Braccesco, il presente saggio indaga alcuni degli intrecci attraverso i quali Roberto Longhi si è fatto memoria attiva in vari scrittori del Novecento. Scrittore e maestro di scrittori, Longhi ha agito sia attraverso tratti stilistici sia attraverso un “occhio” e un sentimento delle cose che ne hanno reso talmente indimenticabile la lezione da permettere di parlare di una “funzione Longhi” nel corso della seconda metà del secolo trascorso. Sintomatica la coincidenza, per esempio, a partire da differenti versioni – tra Mario Soldati, Giorgio Bassani, Giovanni Testori –, di aneddoti dalle risonanze “proustiane”. Da questo e da altri riscontri è possibile aggiungere un capitolo nuovo alla cospicua bibliografia che su Longhi si è addensata, e che ha notoriamente un punto di snodo nei celebrati scritti di Gianfranco Contini
Dephasing-Induced Mobility Edges in Quasicrystals
No full textMobility edges (ME), separating Anderson-localized states from extended states, are known to arise in the single-particle energy spectrum of certain one-dimensional lattices with aperiodic order. Dephasing and decoherence effects are widely acknowledged to spoil Anderson localization and to enhance transport, suggesting that ME and localization are unlikely to be observable in the presence of dephasing. Here it is shown that, contrary to such a wisdom, ME can be created by pure dephasing effects in quasicrystals in which all states are delocalized under coherent dynamics. Since the lifetimes of localized states induced by dephasing effects can be extremely long, rather counterintuitively decoherence can enhance localization of excitation in the lattice. The results are illustrated by considering photonic quantum walks in synthetic mesh lattices.The author acknowledges the Spanish State Research Agency, through the Severo Ochoa and Maria de Maeztu
Program for Centers and Units of Excellence in R&D (Grant No. MDM-2017-0711).Peer reviewe
Storie di chiese, storie di comunità. Progetti, cantieri, architetture
No full textL'architettura di ogni chiesa narra un intreccio particolare e unico di dibattiti ecclesiali e questioni tecniche, scelte individuali e committenze comunitarie, esigenze funzionali e istanze espressive, processi di lunga durata e decisioni repentine. Il volume indaga la storia dell'architettura dei complessi parrocchiali tra gli anni del concilio Vaticano II e l'inizio del nuovo Millennio, muovendo dall'analisi di trenta casi-studio, interpretati come testimoni della storia della Chiesa e come elementi caratterizzanti il paesaggio italiano del secondo Novecento. L'agire architettonico delle comunità cristiane viene raccontato come storia di responsabilità, personali e collettive, e come sequenza di continue modificazioni: le parrocchie sono cantieri mai conclusi, in cui si manifestano passioni mai sopite e aspirazioni mai pienamente raggiunte. L'architettura dei complessi ecclesiali è quindi analizzata come prodotto sociale, esito di articolati processi di ideazione, costruzione e trasformazione, terreno di confronto tra modelli ecclesiologici, disposizioni liturgiche, pratiche sociali e poetiche spaziali. L'edificio e la comunità si rispecchiano vicendevolmente, in ogni fase della loro storia, dalla genesi culturale e teologica del progetto, alle tante negoziazioni quotidiane di adeguamento, adattamento e aggiornamento che trasformano le chiese in architetture senza architetti. Ogni comunità è infatti l'interprete, il custode e il riformatore del proprio complesso parrocchiale, opera aperta in cui l'architettura si misura con le sfide poste dall'ospitalità liturgica e sociale cui è chiamata.Il volume presenta progetti di Anselmi & Associati, Franco Antonelli, Archicura,Lando Bartoli, Sandro Benedetti, Francesco Berarducci, Mario Botta, Guido Campodonico, Enrico Castiglioni, Cicoria-Cognigni-Crescenzi-D'Agostino-Del Re-Marchionni-Nimis , Marco Contini-Claudio Bernardi-Raffaele Ghillani, Justus Dahinden, Giuseppe Del Rio, Roberto Gabetti e Aimaro Isola / Isolarchitetti, Glauco Gresleri, Thomas Höller-Georg Klotzner, Enea Manfredini, Giovanni Michelucci, Nicola Pagliara, Sandro Pittini, Gio Ponti, Paolo Portoghesi-Vittorio Gigliotti, Ludovico Quaroni, Carlo Quintelli, Roberto Rosset-Pier Giorgio Trevisan, Aldo Loris Rossi-Donatella Mazzoleni, Costantino Ruggeri-Luigi Leoni, Antonio Tramontin, Transit Design, Giuseppe Varaldo-Giovanna Maria e Gian Pio Zuccotti-Maria Carla Lenti-Gianfranco Fasana. Postfazioni di Paolo Tomatis e Roberto Repole
Algebraic Localization–Delocalization Phase Transition in Moving Potential Wells on a Lattice
No full textThe localization and scattering properties of potential wells or barriers uniformly moving on a lattice are strongly dependent on the drift velocity, owing to a violation of the Galilean invariance of the discrete Schrödinger equation. Here a type of localization–delocalization phase transition of algebraic type is unraveled, which does not require any kind of disorder and arises when a power-law potential well drifts fast on a lattice. While for an algebraic exponent lower than the critical value dynamical delocalization is observed, for asymptotic localization, corresponding to asymptotic frozen dynamics, is instead realized. At the critical phase transition point an oscillatory dynamics is found, corresponding to Bloch oscillations. An experimentally accessible photonic platform for the observation of the predicted algebraic phase transition, based on light dynamics in synthetic mesh lattices, is suggested.The author acknowledges the Spanish State Research Agency, through the Severo Ochoa and Maria de Maeztu Program for Centers and Units of Excellence in R&D (Grant No. MDM-2017-0711).Peer reviewe
Neural-Network-Based Discrete-Time Variable Structure Control of Robotic Manipulators
No full textThis paper presents a neural-network-based discrete-time variable structure control for a planar robotic manipulator. Radial basis function neural networks are used to learn about uncertainties affecting the system. The analysis of the control stability is given and the controller is experimentally evaluated on the ERICC robot arm. The experiments show that the proposed controller produces good trajectory tracking performance and is robust in the presence of model inaccuracies
Sul ‘Prometeo incatenato’. Tragedia dello sguardo e anatomie del tempo: considerazioni di regia
No full textThe essay aims at showing the development of the critical thought about Prometheus Bound that underlied the staging of this tragedy at the Teatro Greco of Siracusa during the spring of 2012. The performance was directed by the author of these pages for the Istituto nazionale del dramma antico (premiere: Siracusa, 11th May). In the framework of a hermeneutic paradigm based on the ‘critically’ untimely nature of the classic, the staging of Prometheus here discussed wanted to inquire the role of sight in the orchestration of this tragedy, as well as to account for the way time is treated in the text. In the light of this approach, Prometheus looks like a cruel portrait of a world in a state of crisis, suspended between two disasters (one has just ended, the other is looming ominously on the horizon); from its remote distance, such a world gives us an image both lucid and alienated of our present.Il saggio si propone di restituire il percorso di riflessione critica intorno al Prometeo incatenato che nella primavera del 2012 ha sostanziato il processo di messa in scena della tragedia presso il teatro greco di Siracusa, curata dall’autore di queste pagine per conto dell’Istituto nazionale del dramma antico (debutto: Siracusa, 11 maggio). Entro un paradigma ermeneutico fondato sul principio dell’inattualità ‘critica’ del classico, l’allestimento del Prometeo di cui qui si riferisce punta a indagare il ruolo svolto dallo sguardo nell’orchestrazione della tragedia, così come a render ragione del trattamento cui la funzione tempo è sottoposta nell’opera. Sulla base di un simile approccio, il Prometeo appare così come un crudele ritratto di un mondo in crisi sospeso tra due catastrofi (l’una appena trascorsa, l’altra minacciosamente incombente all’orizzonte); un mondo che dalla sua remota distanza ci consegna un’immagine ad un tempo lucida e straniata del nostro presente.</p
Solidarity and Italian Labor Movement Culture: CGIL Intellectuals and Revision of the CGIL’s International Relations (1980–1982)
No full textThe contribution aims to highlight the influence of
the movement of Solidarność on the largest Italian trade union, the General
Confederation of Labor during the peak of the Polish crisis (1980–1982).
The author traces the ambivalences and contradictions of the debate that take
place in the trade union, through an extensive study of the interviews, articles,
internal reports and public speeches of intellectuals and main leaders. A clear
picture emerges of both capacities and limits of Italian trade unionism (as of
the whole Italian left) in understanding the real nature and depth of political
and economic crisis in the socialist world
Self-healing of non-Hermitian topological skin modes
No full textA unique feature of non-Hermitian (NH) systems is the NH skin effect, i.e. the edge localization of an extensive number of bulk-band eigenstates in a lattice with open or semi-infinite boundaries. Unlike extended Bloch waves in Hermitian systems, the skin modes are normalizable eigenstates of the Hamiltonian that originate from the intrinsic non-Hermitian point-gap topology of the Bloch band energy spectra. Here we unravel a fascinating property of NH skin modes, namely self-healing, i.e. the ability to self-reconstruct their shape after being scattered off by a space-time potential.The author acknowledges the Spanish State Research Agency, through the Severo Ochoa and Maria de Maeztu Program for Centers and Units of Excellence in R&D (Grant No. MDM-2017-0711).N
Genova, Savona, Acqui: Niccolò Longhi prima del suo trasferimento a Roma
No full textNiccolò Longhi (1523-1578 / 1579) is mainly known for his Roman activity as a sculptor and restorer of ancient statues, but when he moved to thi -fund 1543, he had an important , career behind him. During this period he mainly worked in Genoa, in the workshop of Gian Giacomo Della Porta. Of this activity, little is known but some new documents found in the State Archives of Genoa, Massa, Milan and Savona allow to clarify the main stages. Particularly significant is the addition to his catalogue of two works, that shed new light on his brilliant skills as a sculptor: a bust in the Cathedral of Savona and a Eucharistic Tabernacle in the Cathedral of Acqui; of the latter the author proposes a reconstruction since it was dismantled, and its pieces were reused inside and outside the sacred building. Thanks to stylistic comparisons and to the information traced in local sources, the author also reconstructs the original aspect of an altar that Niccolo Longhi seems to have carved for the Cathedral of Acqui. The newly discovered documents strengthen Longhi's links with the workshop of Della Porta, supporting the hypothesis that at the time of his sojourn in Genoa Longhi had the opportunity to work for illustrious patrons such as Antonio Doria. Furthermore, they add important information to the biography of the sculptor, documenting for the first time his activity before 1538. In light of this overall reconsideration of his entire career, it is also possible to identify in the church of San Martino in Viggiù, the artist's birthplace, near Varese, the altarpiece was donated by the artist, and that bears his portrait, and the nortrait of his wife
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