198,584 research outputs found
Leopoldo II di Toscana, il mosaico di Vignale e un progetto di parco archeologico nella Maremma dell’800
No full textDuring the ongoing archaeological research at Vignale (near Piombino, Tuscany) a large and very interesting Late Antique floor mosaic was unearthed. Really, it would be more appropriate to speak of a rediscovering, since the mosaic was originally excavated by the Grand Duke of Tuscany Leopold II, in 1830-1831. A few years later, the mosaic and the surrounding building (believed to be a large Roman bath) were included into a sort of early archaeological park, maybe one of the first we know. Despite of this clear interest by Leopold II, the mosaic was apparently never seen by any scholar or traveller, since we don’t have any documentation, or even information, of it.
Nevertheless, it was probably visible until the first decade of the 20th century, when it was intentionally concealed under the floor of a rural barn, until the archaeological rediscovering in 2014
Autocostruire la professione dell'architetto
No full textIl contributo solleva una questione cruciale nel contesto dell’architettura: il crescente consumo di risorse e lo spreco nel settore delle costruzioni. Questo settore, responsabile di circa la metà delle risorse estratte e produttore di circa la metà di rifiuti speciali, ha un ruolo chiave nella transizione verso un’economia sostenibile. Il contributo esplora il concetto di economia circolare e il ruolo delle comunità e degli abitanti nella trasformazione del territorio attraverso un’analisi di casi pilota portati avanti dall’autore. I casi pilota descritti sono: Cyclhub: ciclofficina popolare autocostruita e mobile nata grazie a una campagna crowdfunding di successo; ResPubblica: intervento di placemaking temporaneo per dare visibilità a uno spazio urbano poco abitato della città di Varese; B///ella:
restyling, in autocostruzione e con l’utilizzo di materiali naturali, degli uffici della Casa della Carità a Varese; Casamatta: Circular Hub di Legambiente ai Mulini di Gurone, in cui volontari e studenti portano avanti un recupero edilizio principalmente con materiali di scarto; Re-sign: piattaforma digitale che innesca e promuove la circolarità del settore A&C. Attraverso la prospettiva dell’autocostruzione, del “learning by doing”, del riuso di materiali e della promozione di progetti dal basso, si esamina il ruolo potenziale dell’architetto come “civic professional”
Structural Reliability of Bridges Made with EAF Concretes
No full textThe development of sustainable concretes is becoming an emerging issue in civil construction sector. The use of Electric Arc Furnace (EAF) slag aggregates in the production of concretes is one way to fulfill sustainability goals. Past research demonstrated a significant increase of mechanical properties of EAF concretes when compared with ones made with natural aggregates (NA); however, at the same time, their use implies also an increase of self-weight loads. The present contribution aims to investigate the reliability of structural systems realized with EAF concretes, with special emphasis to bridge structures. Two different bridge types, considered as case-study examples, are designed considering ordinary concrete mixes, and subsequently, a reliability analysis is run for each EAF concrete class in order to investigate the variation of structural safety margins related to the use of the sustainable EAF concretes in replacement to the ordinary NA concrete mix
Nuove leggi di correlazione tra parametri di sintesi del moto sismico e osservazioni di intensità macrosismica attribuite con l'uso della scala macrosismica europea EMS-98
No full textLo studio della correlazione tra intensità macrosismiche osservate a seguito di evento sismico e le stime dei parametri di sintesi del moto sismico derivabili dai segnali accelerometrici registrati in corrispondenza delle stazioni accelerometriche risulta essere tuttora di rilevante interesse nell’ambito delle applicazioni di ingegneria sismica orientate all’analisi degli effetti alla scala territoriale di scenari sismici. A tal riguardo, differenti formulazioni sono state proposte nel corso degli scorsi decenni da vari autori internazionali, con l’obiettivo di cogliere la relazione funzionale tra i parametri di sintesi più comunemente utilizzati (ad esempio PGA, PGV, PGD) e le stime di intensità macrosismica attribuite con le diverse scale
macrosismiche esistenti (tra le varie, le scale MCS, MM, MSK). Una revisione dello stato dell’arte sui modelli proposti in letteratura scientifica negli ultimi 70 anni è stata presentata nello studio di Zanini et al., 2019. Tuttavia, emergono alcune criticità rilevanti dall’analisi dello stato dell’arte: in primis, la maggior parte delle relazioni non sono invertibili, ovvero sono state calibrate tramite classici procedimenti di regressione lineare e pertanto forniscono solo un’applicazione univoca (ovvero da intensità macrosismica a parametri di sintesi del moto sismico, le cosiddette IGMCE - Intensity to Ground Motion Conversion Equations, oppure da parametri di sintesi del moto sismico a intensità macrosismiche, le GMICE - Ground Motion to Intensity Conversion Equations). Oltre a tale aspetto, allo stato attuale non sono disponibili leggi di conversione in grado di trasformare parametri di sintesi del moto sismico in valori di intensità macrosismica in accordo alla più recente versione della Scala Macrosismica Europea EMS-98. Se da un lato, tale questione potrebbe essere superata facendo leva sul fatto che per livelli di intensità intermedi i gradi di intensità tra le principali scali macrosismiche sembrerebbero
ragionevolmente potersi considerare equivalenti (Musson et al., 2010), e altresì vero che è stato dimostrato in letteratura come per livelli di intensità maggiori possano verificarsi significative discrepanze tra le assegnazioni di intensità formulate utilizzando differenti scale. Pertanto, partendo da questo stato di fatto, il presente contributo illustra i risultati originali ottenuti dagli autori che hanno portato alla costruzione del primo database di coppie di valori di parametri di sintesi del moto sismico e intensità macrosismiche formulate con la scala EMS-98, ed alla successiva calibrazione di un set di leggi di conversione tramite l’uso di una procedura di regressione ortogonale, ottenendo in tal modo leggi di conversione completamente invertibili (ovvero contemporaneamente GMICE ed IGMCE)
Quasistatic delamination problem
No full textWe study delamination of two elastic bodies glued together by an adhesive that can undergo a unidirectional inelastic rate-independent process. The quasistatic delamination process is thus activated by time-dependent external loadings, realized through body forces and displacements prescribed on parts of the boundary. The novelty of this work consists of considering the glue as infinitesimally thin and ideally rigid in the sense that a crack in the glue cannot be seen before, speaking ``microscopically'', all macromolecular links of the adhesive are fully debonded. The concept of energetic solution is applied and existence of such solutions is proved by showing Gamma-convergence of a suitable approximation that, in addition, allows for a direct computer implementation, unlike the original problem
Groundwater contaminant source characterization through artificial neural networks
No full textWater plays a crucial role in human life and in all its activities. For this reason, all water resources and in particular groundwater should be managed in a sustainable way in order to satisfy current needs and without causing environmental consequences. Unfortunately, economies based on intensive agriculture and industrial production lead to unsustainable use of water, the effect of which also includes the contamination of aquifers. In this context, the identification of the location of the contaminant source with its release history has attracted great attention within the scientific community called upon to provide theoretical methods to limit the spread of the contaminant. To identify remediation strategies immediately is essential to have a tool that can provide accurate results in real time. With this aim, surrogate models can become the conceptual models of primary choice being able to study forward and inverse transport problem using a number of observations, which is not much greater than the unknown parameters to be calculated, reducing in this way the computational cost compared with other more complex models. Data-driven surrogate models lead to the field of Artificial Intelligence where neural networks, trained on a finite dataset, are able to estimate the desired output by means of a learning process emulating the behavior of the human brain.
In this work, a feedforward artificial neural network (FFWD-ANN) has been developed to analyze different cases as surrogate model. The investigated domain has been selected from a literature study (Ayvaz, 2010) and the training dataset has been randomly developed by means of the Latin Hypercube Sampling in order to reduce the number of forward simulations. Initially, the network has been trained to solve forward transport problem. In the proposed approach, the ANN well estimates the pollutant concentrations in 7 monitoring wells, at different times, by using as input data the release history at two contaminant sources with known locations. Then, the surrogate model has been trained to deal with inverse transport problem related to different application cases: 1. estimation of the release history at one contaminant source with known location; 2. simultaneous estimation of the release history and location of one contaminant source; 3. estimation of the release history at two contaminant sources with known location; 4. simultaneous estimation of the release history at two contaminant sources with known location and error on observations.
The results have been compared with literature data (Ayvaz, 2010; Jamshidi et al. 2020). Artificial Neural Network seems to be well suited to dealing with this type of forward and inverse problems, preserving the reliability of the results and reducing the computational burden of numerical models.
This research was developed under the scope of the InTheMED project. InTheMED is part of the PRIMA Program supported by the European Union's Horizon 2020 Research and Innovation Program under Grant Agreement No 1923.
Jamshidi, A., Samani, J.M.V., Samani, H.M.V., Zanini, A., Tanda, M.G., Mazaheri, M., 2020. Solving Inverse Problems of Unknown Contaminant Source in Groundwater-River Integrated Systems Using a Surrogate Transport Model Based Optimization. Water 12, 2415.
Ayvaz, M.T., 2010. A linked simulation–optimization model for solving the unknown groundwater pollution source identification problems. J. Contam. Hydrol. 117, 46–59
Una lezione di archeologia globale. Daniele Manacorda e il rinnovamento dellʼarcheologia italiana
No full textL'articolo è incentrato sulla ricostruzione del contributo che Daniele Manacorda ha dato al rinnovamento dell'archeologa italiana nell'ultimo decennio
From Finite to Linear Elastic Fracture Mechanics by Scaling
No full textIn the setting of finite elasticity we study the asymptotic behaviour of a crack that propagates quasi-statically in a brittle material. With a natural scaling of size and boundary conditions we prove that for large domains the evolution with finite elasticity converges to the evolution with linearized elasticity. In the proof the crucial step is the (locally uniform) convergence of the non-linear to the linear energy release rate, which follows from the combination of several ingredients: the -convergence of re-scaled energies, the strong convergence of minimizers, the Euler-Lagrange equation for non-linear elasticity and the volume integral representation of the energy releas
Attività di caratterizzazione del Sito F.N. in funzione dell'installazione della cella a carbonati fusi
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