523 research outputs found

    Seismic and Energetic Interventions on a Typical South Italy Residential Building: Cost Analysis and Tax Detraction

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    Italian buildings are mainly represented by unreinforced masonry constructions, which were mostly built before 1970, often without respecting seismic design criteria. The main objective of Italian designers is, therefore, to retrofit these buildings in order to improve their safety under earthquake, as well as to preserve the memory of the ancient building art. In addition, the assessment of the building energetic efficiency is nowadays a very pressing need for designers and practitioners. Energetic efficiency represents the capacity to optimize the consumption of energy resources in order to reach prefixed requirements for the environment protection. This paper shows both seismic and energetic retrofitting interventions on a residential unreinforced masonry building typical of the constructive practice in the South Italy. Initially, the building characterization under geometrical and structural viewpoints is done. Subsequently, the seismic vulnerability verification is performed with unsatisfactory results, so requiring upgrading or retrofitting interventions. Moreover, with the aim to increase living comfort and energy efficiency, energetic upgrading interventions, aimed at decreasing the building transmittance, are proposed. Seismic and energetic interventions are then computed from the economic point of view in order to evaluate the financial contributions foreseen by the Italian 2018 Balance Law through the Sismabonus and Ecobonus tools, respectively. Finally, the study proposes a global performance index able to take into account contemporary the seismic, energetic and economic benefits deriving from retrofitting interventions applied on the inspected residential building

    Large scale seismic vulnerability and risk of masonry churches in seismic prone areas: two territorial case studies

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    In this paper, seismic vulnerability and risk assessment of two samples of churches, located in Teramo and Ischia island (Naples gulf), both affected by the most recent earthquakes that occurred in Italy, are presented. To this aim, we applied a simplified method particularly suitable for seismic evaluations at a territorial scale, providing a global resulting score to be compared among the cases analyzed. The data obtained allowed us to provide vulnerability maps and a seismic risk index for all the considered churches. In addition, the calculated indexes permit a preliminary health state evaluation of the inspected churches, for ranking the priorities and planning additional in-depth evaluations

    The influence of local mechanisms on large scale seismic vulnerability estimation of masonry building aggregates

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    The current paper deals with the seismic vulnerability evaluation of masonry constructions grouped in aggregates through an “ad hoc” quick vulnerability form based on new assessment parameters considering local collapse mechanisms. First, a parametric kinematic analysis on masonry walls with different height (h) / thickness (t) ratios has been developed with the purpose of identifying the collapse load multiplier for activation of the main four first-order failure mechanisms. Subsequently, a form initially conceived for building aggregates suffering second-mode collapse mechanisms, has been expanded on the basis of the achieved results. Tre proposed quick vulnerability technique has been applied to one case study within the territory of Arsita (Teramo, Italy) and, finally, it has been also validated by the comparison of results with those deriving from application of the well-known FaMIVE procedure

    Seismic vulnerability of different in geometry historic masonry towers

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    In the present paper, a simple predictive approach for the seismic vulnerability of existing masonry towers is proposed evaluating it on a series of “idealized” benchmark cases using different simplified approaches, namely the procedure proposed by the Italian code and pushover conducted with two commercial codes (UDEC and Tremuri). In UDEC the geometry is intentionally idealized into quadrilateral elements with different thickness, in order to properly reproduce the hollow square cross-section. The utilization of a 2D approach drasti-cally reduces the computational effort required in carrying out medium scale systematic com-putations. In Tremuri macro-elements are used, providing very fast predictions as well. Within such simplified frameworks, 16 different cases that can be encountered in practice are critically analyzed, changing two key parameters that proved to be important for the vulnerability determination, namely slenderness and transversal shear cross area. The simplifications introduced in the modelling phase allow for fast sensitivity analyses in the inelastic range and an estimation of the acceleration factor in that range of slenderness that is useful for practical purposes. Simplified formulas fairly representing the obtained seismic vulnerability are also reported and put at disposal to any practitioner interested in a prelimi-nary estimation of the behavior of the towers before doing any calculation. For validation purposes, the results obtained previously by one of the authors by means of refined full 3D Abaqus discretizations on 25 existing towers located in the Northern Italy are also reported. Good agreement between the predictions provided by the simplified method here proposed and previously presented reference data is obtained

    On the influence of the aggregate condition on the vibration period of masonry buildings: A case study in the district of Naples

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    The present paper deals with the seismic investigation of a masonry building aggregate within the city of Bacoli (district of Naples) through quick and mechanical analyses with the initial target of evaluating the vibration periods of the individual Structural Units (S.U.) constituting the compound. In conclusion the comparison in terms of seismic vulnerability indexes between S.U. included in the aggregate, distinguishing the position (head or intermediate) in the compound, and the same S.U. considered as isolated constructions has been done

    Specification of skeletal muscle differentiation by repressor element-1 silencing transcription factor (REST)-regulated Kv7.4 potassium channels

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    Changes in the expression of potassium (K(+)) channels is a pivotal event during skeletal muscle differentiation. In mouse C(2)C(12) cells, similarly to human skeletal muscle cells, myotube formation increased the expression of K(v)7.1, K(v)7.3, and K(v)7.4, the last showing the highest degree of regulation. In C(2)C(12) cells, K(v)7.4 silencing by RNA interference reduced the expression levels of differentiation markers (myogenin, myosin heavy chain, troponinT-1, and Pax3) and impaired myotube formation and multinucleation. In K(v)7.4-silenced cells, the differentiation-promoting effect of the K(v)7 activator N-(2-amino-4-(4-fluorobenzylamino)-phenyl)-carbamic acid ethyl ester (retigabine) was abrogated. Expression levels for the repressor element-1 silencing transcription factor (REST) declined during myotube formation. Transcript levels for K(v)7.4, as well as for myogenin, troponinT-1, and Pax3, were reduced by REST overexpression and enhanced upon REST suppression by RNA interference. Four regions containing potential REST-binding sites in the 5′ untranslated region and in the first intron of the K(v)7.4 gene were identified by bioinformatic analysis. Chromatin immunoprecipitation assays showed that REST binds to these regions, exhibiting a higher efficiency in myoblasts than in myotubes. These data suggest that K(v)7.4 plays a permissive role in skeletal muscle differentiation and highlight REST as a crucial transcriptional regulator for this K(+) channel subunit

    Protein Kinase C-α Regulates Insulin Action and Degradation by Interacting with Insulin Receptor Substrate-1 and 14-3-3ϵ

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    Protein kinase C (PKC)-alpha exerts a regulatory function on insulin action. We showed by overlay blot that PKC alpha directly binds a 180-kDa protein, corresponding to IRS-1, and a 30-kDa molecular species, identified as 14-3-3 epsilon. In intact NIH-3T3 cells overexpressing insulin receptors (3T3-hIR), insulin selectively increased PKC alpha coprecipitation with IRS-1, but not with IRS-2, and with 14-3-3 epsilon, but not with other 14-3-3 isoforms. Overexpression of 14-3-3 epsilon in 3T3-hIR cells significantly reduced IRS-1-bound PKC alpha activity, without altering IRS-1/PKC alpha co-precipitation. 14-3-3 epsilon overexpression also increased insulin-stimulated insulin receptor and IRS-1 tyrosine phosphorylation, followed by increased activation of Raf1, ERK1/2, and Akt/protein kinase B. Insulin-induced glycogen synthase activity and thymidine incorporation were also augmented. Consistently, selective depletion of 14-3-3 epsilon by antisense oligonucleotides caused a 3-fold increase of IRS-1-bound PKC alpha activity and a similarly sized reduction of insulin receptor and IRS-1 tyrosine phosphorylation and signaling. In turn, selective inhibition of PKC alpha expression by antisense oligonucleotides reverted the negative effect of 14-3-3 epsilon depletion on insulin signaling. Moreover, PKC alpha inhibition was accompanied by a > 2-fold decrease of insulin degradation. Similar results were also obtained by overexpressing 14-3-3 epsilon. Thus, in NIH-3T3 cells, insulin induces the formation of multimolecular complexes, including IRS-1, PKC alpha, and 14-3-3 epsilon. The presence of 14-3-3 epsilon in the complex is not necessary for IRS-1/PKC alpha interaction but modulates PKC alpha activity, thereby regulating insulin signaling and degradation
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