Sistemi di tipo pendolare ad attrito per l'isolamento alla base degli edifici

Nell’articolo viene presentata una sintesi dei risultati di una ricerca sperimentale e numerica svolta, in collaborazione fra le Università di Firenze e di Buffalo (New York), sul tema dell’isolamento alla base mediante sistemi pendolari ad attrito, di tipo “Single” (SFP), “Double” (DFP) e “Triple Friction Pendulum” (TFP). In particolare, lo studio ha avuto come obiettivo la stima delle caratteristiche meccaniche e delle effettive potenzialità della più recente fra tali tecnologie, rappresentata dalla soluzione TFP, verificate su base sperimentale e convalidate da un’ampia indagine numerica di confronto, condotta in riferimento a differenti modalità di combinazione dei sistemi SFP, DFP e TFP e dissipatori viscosi lineari e non

Identidad y auto-representación social en Hannah Arendt

El ser humano, para Arendt, se caracteriza por la acción y el discurso, a través de los cuales revela la unicidad de su identidad personal. Por la acción discursiva, el hombre se inserta en un mundo plural, que comparte con otros actores. Luego de recorrer conceptos centrales del pensamiento arendtiano (la novedad del acontecimiento, la libertad, la natalidad, la preexistencia del mundo), el artículo finalmente examina dos notas de la acción: su imprevisibilidad y su irreversibilidad. El remedio a ellas se encuentra, respectivamente, en la capacidad de perdonar y en la capacidad de hacer y mantener promesas. El carácter interpersonal del perdón y la promesa manifiestan que el ser humano es constitutivamente relacional y, a la vez, el valor de la singularidad

Advanced Seismic Retrofit of a Mixed R/C-Steel Structure

A study concerning the performance assessment and enhanced retrofit of public buildings originally designed without any anti-seismic provisions is presented herein. A representative structure belonging to this class was demonstratively examined, i.e., a school built in Italy in the early 1970s, before a coordinate national Seismic Standard was issued. The building is characterized by a mixed reinforced concrete (ground storey)-steel (first and second storey) frame skeleton. An extensive on-site experimental investigation was developed in the first step of the study, which helped identify the mechanical characteristics of the constituting materials, and re-draw the main structural details. Based on these data, and relevant updates of the finite element model of the structure, the seismic assessment analyses carried out in current conditions highlighted several performance deficiencies, in both the reinforced concrete and steel members. An advanced seismic retrofit hypothesis of the building was then designed, consisting of the installation of a set of dissipative braces incorporating fluid viscous dampers as protective devices. This solution makes it possible to attain an elastic structural response up to the maximum considered normative earthquake level, while at the same time causing more limited architectural intrusion and lower costs as compared to conventional rehabilitation strategies

Seismic Assessment and Retrofit Design of a School Building in Florence

The recent earthquakes occurred in Italy highlighted again the high vulnerability of structures built before the release of national Seismic Standards. This induced several local authorities to undertake extensive performance assessment campaigns of public buildings, among which mainly schools. A study carried out within one of these campaigns, concerning the evaluation of seismic vulnerability and the design of retrofit interventions in a school building in Florence, is presented herein. The structure was built at the beginning of 1970s, and is characterized by a ground storey with reinforced concrete frame skeleton, and a first and second storey with steel structure. An extensive on-site experimental investigation was developed at a first step of the study, which allowed identifying the mechanical characteristics of the constituting materials, and re-drawing the main structural details. Based on these data, a check of the seismic performance in current conditions was carried out, which highlighted several drawbacks, especially concerning the steel members. This prompted to propose a seismic retrofit hypothesis of the building, consisting in the installation of a set of dissipative braces incorporating fluid viscous dampers as protective devices. A synthesis of the assessment analyses in current conditions and the retrofit design, which allows attaining an elastic structural response up to the maximum considered earthquake level, is reported in the paper

Structural health monitoring of Artemio Franchi Stadium in Florence, Italy: measurement using interferometric radar

The \u201cArtemio Franchi\u201d Stadium in Florence, Italy, designed by Pier Luigi Nervi in 1929, was built from 1930 to 1932. The stadium has a reinforced concrete structure and it is composed by 24 stands, a 50-meter tower (\u201cMaratona\u201d tower) and a cantilever roof. In occasion of the World Cup in 1990 the stadium was renovated by adding seats at the ground level as retrofit. A study for seismic requalification is in progress and an interferometric radar has been used for monitoring the architectural complex. In particular, the radar monitored the \u201cMaratona\u201d tower and some of the stands. In this paper, the experimental results of this preliminary measurement campaign are reported. The interferometric radar is a remote sensor for monitoring large structures. When the structure under test is excited by external actions (i.e. wind, vehicular traffic, vibrodyne), the interferometric radar is able to detect the displacements of the structure and to measure its natural frequencies. The wind action was exploited to test the \u201cMaratona\u201d tower. The tower is a 30-meter tower located on a reinforced-concrete slab placed in the middle of the grandstand on the east-side of the Stadium, close to one of its well-known spiral stairs. Inside the tower an elevator is hosted. This measurement was performed both with an interferometric radar and a seismic accelerometer. The radar was installed close to an entrance of stadium, the seismic accelerometer was installed on the tower\u2019s attic. Natural frequencies were measured for these structures with both instruments, and the results were in good agreement. The stands are too rigid to be appreciably excited by wind or vehicular traffic, hence the measurements were performed during football matches. The supporters\u2019 movements were used as input action to measure the dynamic properties of stands. Unfortunately, this input was not enough wide to allow the measurement of the natural frequencies of all the stands. The experimental results of stands have been compared with a numerical model

???Pull-through??? Resection for Total and Subtotal Glossectomy Involving the Posterior Third of Tongue

The lower lip-splitting incision associated with different types of mandibulotomy, in order to obtain wide access to total or subtotal glossectomy, is described. In those cases, high rates of functional and aesthetic deficit and postoperative morbidity (more in cases of patients in which adjuvant radiotherapy has been performed) are described. We present our experience in the treatment of patients undergoing total or subtotal glossectomy and contemporary reconstruction with flaps, and without lip-splitting incision and mandibulotomy. Materials and Methods: Data about patients affected by malignant tumors requiring total or subtotal (posterior third of the tongue) resection that were treated at our department from January 2004 to December 2014 were retrospectively reviewed. Data evaluated included: T and N stage, resection margins, operation time, and post-operative complications, such as fistula and flap necrosis. Results: 41 patients were identified. In two cases microscopic infiltration of one margin was found (R1); in one case a close margin was identified. In 26 cases reconstruction was performed using free flaps, and in the remaining cases a pectoralis major flap was used. In three cases postoperative complications were observed. Discussion and conclusions: In theory, lip-splitting and mandible discontinuity could allow for increased access and tumor visualization, and could facilitate flap positioning. Nevertheless, in our experience, it is not necessary in the case of total or subtotal glossectomy

An Exploratory Study of Field Failures

Field failures, that is, failures caused by faults that escape the testing phase leading to failures in the field, are unavoidable. Improving verification and validation activities before deployment can identify and timely remove many but not all faults, and users may still experience a number of annoying problems while using their software systems. This paper investigates the nature of field failures, to understand to what extent further improving in-house verification and validation activities can reduce the number of failures in the field, and frames the need of new approaches that operate in the field. We report the results of the analysis of the bug reports of five applications belonging to three different ecosystems, propose a taxonomy of field failures, and discuss the reasons why failures belonging to the identified classes cannot be detected at design time but shall be addressed at runtime. We observe that many faults (70%) are intrinsically hard to detect at design-time

Intraconal tumor-like mass as first manifestation of IgG4-related disease

A great variety of tumors and tumor-like lesions can involve the orbit. Benign and malignant neoplasms, inflammatory diseases, vascular and congenital lesions take part of this heterogeneous group that creates many challenges for diagnosis, management, and treatment. Obviously, symptoms and clinical history are fundamental to establish a differential diagnosis, and imaging is mandatory to distinguish between lesions that have similar clinical presentations in most cases. With this report, the authors highlight the diagnostic difficulties and the importance to include not only tumors but also vascular inflammatory process into the differential diagnosis of this unilateral orbital lesion type

Facial Palsy: The Right Time for the Right Choice

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