Dynamic identification of building structures: new strategies:Meccanica dei materiali e delle strutture

In this paper the evolution of a time domain dynamic identification technique based on a statistical moment approach is presented. This technique can be used in the case of structures under base random excitations in the linear state and in the non linear one. By applying Itoˆ stochastic calculus, special algebraic equations can be obtained depending on the statistical moments of the response of the system to be identified. Such equations can be used for the dynamic identification of the mechanical parameters and of the input. The above equations, differently from many techniques in the literature, show the possibility of obtaining the identification of the dissipation characteristics independently from the input. Through the paper the first formulation of this technique, applicable to non linear systems, based on the use of a restricted class of the potential models, is presented. Further a second formulation of the technique in object, applicable to each kind of linear systems and based on the use of a class of linear models, characterized by a mass proportional damping matrix, is described.

La pomice per il confezionamento di calcestruzzi leggeri strutturali:Meccanica dei materiali e delle strutture

Abstract. The possibility of using pumice aggregates for concrete in structural applications is discussed. In particular, the mix design of lightweight concrete for the manufacturing masonry units having proper strength, is discussed. Moreover, the design of the unit shape according to the technical code requirements and making it possible to arrange reinforcing steel bars is described. Reinforced bearing masonry walls, made with the concrete units in question, were manufactured and tests on the panels and on the designed units were carried out. For comparison, tests on concrete units and structural elements were carried out after the substitution of pumice aggregates with ordinary lightweight aggregates, proving that pumice can be considered an alternative to them. Sommario. L’uso della pomice come inerte per il confezionamento di calcestruzzo è poco diffuso sebbene essa sia stata usata già in antiche costruzioni come il Pantheon in Roma. In questo studio si affronta la possibilità di realizzare blocchi in calcestruzzo alleggerito con granuli di pomice. I blocchi, progettati e realizzati secondo le indicazioni normative correnti, sono stati usati per realizzare pannelli murari armati da sottoporre a carichi ciclici orizzontali. I risultati ottenuti, messi a confronto con quelli di pannelli realizzati con blocchi in cls alleggerito con argilla espansa, hanno mostrato la possibilità di utilizzare la pomice come validissima alternativa all’argilla espansa.

Experimental investigation on masonry panels manufactured with pumice lightweight concrete:Meccanica dei materiali e delle strutture

Abstract. The possibility of using pumice aggregates for concrete in structural applications is discussed. In particular, the mix design of lightweight concrete for the manufacturing masonry units having proper strength, is discussed. Moreover, the design of the unit shape according to the technical code requirements and making it possible to arrange reinforcing steel bars is described. Reinforced bearing masonry walls, made with the concrete units in question, were manufactured and tests on the panels and on the designed units were carried out. For comparison, tests on concrete units and structural elements were carried out after the substitution of pumice aggregates with ordinary lightweight aggregates, proving that pumice can be considered an alternative to them. Sommario. L’uso della pomice come inerte per il confezionamento di calcestruzzo è poco diffuso sebbene essa sia stata usata già in antiche costruzioni come il Pantheon in Roma. In questo studio si affronta la possibilità di realizzare blocchi in calcestruzzo alleggerito con granuli di pomice. I blocchi, progettati e realizzati secondo le indicazioni normative correnti, sono stati usati per realizzare pannelli murari armati da sottoporre a carichi ciclici orizzontali. I risultati ottenuti, messi a confronto con quelli di pannelli realizzati con blocchi in cls alleggerito con argilla espansa, hanno mostrato la possibilità di utilizzare la pomice come validissima alternativa all’argilla espansa.

'That Puissant City': John Milton's Roman Sojourns 1638-1639

John Milton’s sojourns in Rome (1638-9) are attested by his comments in Defensio Secunda, by the minutes of the English College, by Latin encomia which he received from Roman academicians, and, not least, by his Latin letter to Lucas Holstenius (19/29 March 1639), and several Latin poems which he composed in the course of his residency in the capital city: Ad Salsillum, and three Latin epigrams extolling the praises of the virtuosa soprano, Leonora Baroni. Read together, these texts serve to reveal much about Milton’s participation in, and reaction to, the ‘Puissant City’, (History of Britain, Bk 2).

The present monograph presents fresh evidence of Milton's integration into the academic and cultural life of seventeenth-century Rome. It argues that his links with two Roman academies: the Accademia dei Fantastici and Accademia degli Umoristi constitute a sustained participation in an academic community paralleling that of his independently attested performance in Florentine academies (on which I have published extensively). It also investigates his links with Alessandro Cherubini, David Codner, Giovanni Batista Doni, and the Baroni circle hymned in three published anthologies.

Chapter 1: Milton and the Accademia dei Fantastici investigates the cultural climate surrounding Milton's Ad Salsillum by examining two of that academy's publications: the Poesie dei Signori Accademici Fantastici di Roma (Rome, 1637) and the Academia Tenuta da Fantastici a. 12 di Maggio 1655 (Rome, 1655), the latter celebrating the creation of Fabio Chigi as Pope Alexander VII on 5 April 1655. Read in a new light, Milton’s self-fashioning, it is argued, takes its place not only alongside Salzilli’s encomium in Milton's honour, and his Italian sonnets in the 1637 Poesie, but also in relation to other poems in that collection, and the academy's essentially Catholic eulogistic trend. The chapter also provides fresh evidence of Salzilli’s survival of the illness described in Milton’s poem by his epistolary correspondence with Tomaso Stigliani.

Chapter 2: Milton and the Vatican argues for links between Milton’s Latin letter to Holstenius and a range of Holstenius’ published works: his edition of the axioms of the later Pythagoreans gifted by him to Milton, and his published neo-Platonic works. This is achieved by mutual appropriation of Similitudes in a series of Miltonic similes, the anabasis/katabasis motifs in a reworking of the Platonic theory of the transmigration of souls, and allusion to etymological details highlighted in Holstenius’ published editions. The chapter also reveals Milton’s alertness to typographical procedures and, by association, to Holstenius’ recent role (1638) as Director of the press of the Biblioteca Vaticana.

Chapter 3: Milton and the Accademia degli Umoristi argues for Milton’s likely participation in this Roman academy, as suggested by his links with its members. His three Latin epigrams in praise of Leonora Baroni, the only female member of the Umoristi, have hitherto been studied in relation to the 1639 Applausi in her honour. In a new reading, Milton, it is suggested, invokes and interrogates Catholic doctrine before a Catholic audience only to view the whole through the lens of a neo-Platonic Hermeticism (by echoing the phraseology of the sixteenth-century Franciscan Hannibal Rosselli) that refreshingly transcends religious difference. Crucially, the hitherto neglected L’Idea della Veglia (Rome, 1640) includes further encomiastic verse, sonnets to, and by Leonora, and details of the conversazioni hosted by her family at the precise time of Milton’s Roman sojourns. Milton may well have been a participant. The chapter concludes in an assessment of his links with the youthful prodigy Alessandro Cherubini, and of his audience with Francesco Barberini.

Chapter 4: Milton at a Roman Opera analyses the potential impact of ‘Chi Soffre, Speri’, which he attended on 18/28 February 1639, mounted by Francesco Barberini to inaugurate the recently completed theatre of the Palazzo Barberini. A detailed analysis of the opera's libretto, music, and theatricality casts a backward glance to Milton's Comus, and a forward glance to Paradise Lost. It also assesses Milton’s musical interests at this time, as attested by his links with Doni, and his purchase of works by Monteverdi and others.

Chapter 5: Milton’s English Connections in Rome develops the work of Miller and Chaney by investigating Milton’s co-diners at the English College in Rome on 30 October 1638, and by analysing his links between David Codner (alias Matteo Selvaggio), and the family of Jane Savage, Marchioness of Winchester, lamented by Milton in 1631. It also assesses his potential relations with the Englishman Thomas Gawen, who ‘accidentally sometimes fell into the company of John Milton’ (Antony Wood).