Seismic strengthening of a theatre masonry building by using active FRP wires

Masonry buildings of the architectural heritage were often built with poor materials and according to irregular structural schemes. This occurrence is critical when forces due to earthquakes should be taken into account for the assessment of structural vulnerability. It is well known that seismic forces are able to activate failure mechanisms that constitute typical collapse schemes of masonry buildings during earthquakes, when masonry elements are not adequately connected. In the last years new materials were employed as strengthening systems for structural purposes, and composite materials are those that have found a large field of application in this context. A new technique for seismic strengthening is presented in the paper, with reference to a real application. The application will be presented with reference to a historical masonry building used as public theatre, in which four pre-tensioned Fiber Reinforced Polymer (FRP) wires were designed and applied as external strengthening ties. The paper illustrates a study of seismic vulnerability for a large building used as theatre, through linear and non linear kinematic analyses. The results of the analyses allowed to understand the possible failure mechanisms that needed to be inhibited. The use of FRP pre-tensioned wires, 40 meters long, shows itself to be an effective structural solution in terms of costs and speed of application in order to reduce the seismic vulnerability. The results of the analyses will be illustrated and discussed in the paper, also with reference to the experimental tests that were necessary for the characterization of the material properties. The results will show how the presence of the FRP system is able to prevent possible collapses of the slender walls that are present in the building. The differences between the results of linear and non linear analyses will also be shown and discusse

Ibridazione e molteplicità della cultura per la rigenerazione urbana. Evidenze empiriche da alcuni programmi italiani di finanziamento ministeriali e di fondazioni

Negli ultimi anni le politiche hanno favorito il ruolo di primo piano della cultura nella rigenerazione urbana in Italia, finanziando e sostenendo non solo istituzioni culturali e artistiche, ma anche fornendo nuove opportunità economiche a gruppi e associazioni di comunità emergenti. La ricerca sugli interventi urbani a base culturale ha tuttavia adottato per lo più un livello di analisi focalizzato su casi e singole esperienze, mancando la possibilità di cogliere tendenze generali utilizzabili nella costruzione di politiche. Il contributo si propone di far avanzare lo stato dell'arte del dibattito nazionale sui processi di rigenerazione a base culturale di lunga durata, offrendo una visione panoramica del fenomeno in Italia. La ricerca si basa sull'analisi di tre database di domande di progetto per programmi di finanziamento a livello nazionale sulla rigenerazione urbana guidata dalla cultura. Il contributo individua le tendenze e i caratteri comuni più salienti di queste iniziative: i) la dimensione spaziale (ubicazione e patrimonio immobiliare) ii) la costruzione di infrastrutture locali iii) l’ibridazione della cultura. Il contributo sostiene che la cultura non è né uniforme, né isolata nelle iniziative di rigenerazione urbana guidate dalla cultura: la cultura è presente in diverse forme e in diversi tipi di attività, dalla fruizione alla produzione; inoltre, è spesso ibridato con altri servizi, legati a previdenza locale o ad attività commerciali. La maggior parte delle esperienze adotta un approccio orientato alla trasformazione di un'intera area urbana, anche attraverso azioni spaziali e immateriali, tendendo a collaborare con le autorità pubbliche

Combined Punctual and Diffused Monitoring of Concrete Structures Based on Dielectric Measurements

This work presents a microwave reflectometry-based system for monitoring large concretestructures (during the curing process and also while the structure is in use), through the combineduse of punctual and diffused sensing elements. In particular, the adoption of punctual probes ona reference concrete specimen allows the development of an innovative and accurate calibrationprocedure, useful to obtain the value of the water content on a larger structure made of the samematerial. Additionally, a wire-like diffused sensing element can be permanently embedded inbuildings and used to monitor the structure along the entire length of the sensing element. Theadopted diffused sensing element can be used not only to detect dielectric variation during the curingprocess, but also throughout the service life of the structure. The combined use of punctual anddiffused sensing elements represents an important innovation from a procedural point of view, ableto provide detailed and quantitative information on the health status of the structure both duringand after construction

Residual Strength and Durability of Glass Fiber FRCM and CRM Systems Aged in Alkaline Environments

Fabric Reinforced Cementitious Matrix (FRCM) and Composite Reinforced Mortar (CRM) systems are used as Externally Bonded Reinforcements (EBR) in civil and historical construction. These materials are made by fibrous reinforcement, in forms of dry (FRCM) or cured (CRM) meshes embedded in a cementitious/hydraulic lime matrix. At present, this technology is considered very promising in the field of structural strengthening, retrofitting and repair existing structures. This is true especially in those cases of masonry and historical buildings, due to the specific criteria of conservation and compatibility with the substrate that need to be fulfilled. These materials, in fact, results more compatible with masonry substrate because of the inorganic matrix, instead of polymeric resin used for the well-known FRP systems (Fiber Reinforced Polymers). The recent use of these new materials in civil engineering needs appropriate and complete guidelines, that regard not only the design aspects but also the durability features. This paper presents the results of a large experimental program focused on the durability of FRCM and CRM systems and their single components, in different alkaline environments. For the whole experimental campaign, the samples have been immersed into three different alkaline solutions, for four exposure times (500, 1000, 2000 and 3000 hrs). In addition, in order to study the different accelerating effects due to temperature, three different temperatures were maintained during the ageing periods: 23°C, 40°C and 70°C. The results about the mechanical characterization of residual properties are discussed in order to highlight the influence of alkaline environments on the mechanical properties of single elements and the whole strengthening systems that were tested herein

Respiratory chain complex I, a main regulatory target of the cAMP/PKA pathway is defective in different human diseases.

In mammals, complex I (NADH-ubiquinone oxidoreductase) of the mitochondrial respiratory chain has 31 supernumerary subunits in addition to the 14 conserved from prokaryotes to humans. Multiplicity of structural protein components, as well as of biogenesis factors, makes complex I a sensible pace-maker of mitochondrial respiration. The work reviewed here shows that the cAMP/PKA pathway regulates the biogenesis, assembly and catalytic activity of complex I and mitochondrial oxygen superoxide production. The structural, functional and regulatory complexity of complex I, renders it particularly vulnerable to genetic and sporadic pathological factors. Complex I dysfunction has, indeed, been found, to be associated with several human diseases. Knowledge of the pathogenetic mechanisms of these diseases can help to develop new therapeutic strategies. (C) 2011 Federation of European Biochemical Societies. Published by Elsevier B. V. All rights reserved

Hepatitis B Surface Antigen Seropositive Men in Serodiscordant Couples: Effects on the Assisted Reproductive Outcomes

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