The impact of theoretical assumptions in the determination of the neutrino effective number from future CMB measurements

One of the major goals of future Cosmic Microwave Background measurements is the accurate determination of the effective number of neutrinos $N_{\rm eff}$. Reaching an experimental sensitivity of $\Delta N_{\rm eff} = 0.013$ could indeed falsify the presence of any non-standard relativistic particles at $95 \%$ c.l.. In this paper, we test how this future constraint can be affected by the removal of two common assumptions: a negligible running of the inflationary spectral index $n_{\rm run}$ and a precise determination of the neutron lifetime $\tau_n$. We first show that the constraints on $N_{\rm eff}$ could be significantly biased by the unaccounted presence of a running of the spectral index. Considering the Stage-IV experiment, a negative running of ${\rm d}n/{\rm d}\ln k= - 0.002$ could mimic a positive variation of $\Delta N_{\rm eff} = 0.03$. Moreover, given the current discrepancies between experimental measurements of the neutron lifetime $\tau_n$, we show that the assumption of a conservative error of $\Delta\tau_n \sim 10$s could bring to a systematic error of $\Delta N_{\rm eff} = 0.02$. Complementary cosmological constraints on the running of the spectral index and a solution to the neutron lifetime discrepancy are therefore needed for an accurate and reliable future CMB bound of $N_{\rm eff}$ at percent level.Comment: 7 pages, 3 figure

Dissipazione energetica in presenza di rampe in pietrame sommerse.

Il presente lavoro illustra i risultati di una serie di prove condotte nel Laboratorio di Idraulica del Dipartimento di Ingegneria Civile dell’Università di Pisa sulle rampe in pietrame annegate. I tests sono stati condotti su modelli di rampe in pietrame di diversa scabrezza per le quali sono state indagate 3 pendenze: 1V:4H, 1V:6H, 1V:8H. Si è analizzato il fenomeno relativo alla dissipazione di energia tra monte e valle del manufatto. Si sono quindi ricavate delle correlazioni matematiche tali da risultare utili in fase di progetto e si è infine effettuato un confronto delle relazioni trovate con quelle relative al caso di funzionamento classico delle rampe in pietrame che prevede un deflusso libero su tutta la lunghezza del manufatto

Limit condition for the intermunicipal emergency

The traditional urban planning issues, related to the design and city shape, today are faced with those derived from safety and risk. The Emergency Plan (EP) is the result of study about risk for each context, and it allows to identify potential emergency scenarios. The paper illustrates model of analysis of Intermunicipal Emergency Plan (I-EP) through Limit Condition for the Intermunicipal Emergency I-LCE), with the purpose of large-scale assessment and mitigation of the seismic risk. This is an approach that extends the methodological principles of Limit Condition for the Emergency (LCE) to the territory, we consider that the EP, in the same way as urban planning, is not a planning activity that can be concentrated only on urban area but must work on the “territory system”, especially for the effect control of natural phenomena such as seismic risk. This not only threatens a significant innovation for the LCE but also for its relationship whit the urban planning its design strategies aimed at reducing territorial fragilities. The proposed methodology is applied in the area of Sele, in the district of Salerno (Southern Italy), territory characterized by high levels of seismic and hydrogeological vulnerability. Through this case study we had the opportunity to discuss the potential of I-LCE and its additional recommended updates to increase its effectiveness and efficiency, in addition the necessary innovations of urban and territorial planning systems

Census-based typological usability fragility curves for Italian unreinforced masonry buildings

The main vulnerability models available in the literature aim to develop damage fragility curves to estimate the damage level suffered by a building after a seismic event. However, recent earthquakes have highlighted the great importance of predicting the usability of residential buildings, i.e. the condition of a building being habitable or occupiable after a seismic event. The building usability performance can be used as an indicator for allocating economic funding after a seismic event because recent researches have demonstrated a stronger correlation between repair costs and usability assessment rather than between repair costs and structural damage. Therefore, this work focused on the development of census-based fragility curves for the preventive forecast of the usability of Italian unreinforced-masonry buildings. The proposed usability model was calibrated based on the 2009 L'Aquila earthquake database, including almost 60,000 unreinforced-masonry buildings, and this database was increased by adding data from the Italian census to account for uninspected constructions. Six typological classes were defined considering two parameters available both in the post-earthquake and Italian census databases: construction timespan and state of repair. Additionally, it was highlighted in which cases the number of stories was also relevant. The usability fragility curves were defined as a function of peak ground acceleration for two building usability states: partially unusable and unusable. The results confirmed that older buildings are more vulnerable and clearly pointed out the crucial role of the state of repair as a parameter influencing the building usability

Giudicato amministrativo e riedizione del potere pubblico

Il presente studio propone un’indagine circa i rapporti tra il giudicato amministrativo ed il successivo riesercizio del potere pubblico. Tratta, cioè, dell’individuazione dei confini entro i quali una amministrazione pubblica, successivamente al contenzioso, possa esercitare nuovamente il potere che l’ordinamento le conferisce. L’analisi si dipana su tre capitoli. Il primo è dedicato ad uno studio dogmatico e sistematico degli elementi centrali della trattazione, anche in una prospettiva di teoria generale: dapprima il giudicato, con un immancabile raffronto col processo civile, poi, la componente pubblicistica, con approfondimenti sul potere, sulla discrezionalità e sull’interesse legittimo. Il secondo capitolo vaglia, con taglio critico, le teorie che sono state prospettate, tanto in dottrina quanto in giurisprudenza, circa i problematici rapporti tra il giudicato e la rieffusione del potere pubblico. Infine, col terzo capitolo viene saggiata la sostenibilità pratica e le ricadute delle prospettate ricostruzioni teoriche, rispetto agli specifici profili dei rimedi esperibili a tutela dei soggetti interessati, delle sopravvenienze e della manutenzione della motivazione provvedimentale

Diagonal compression testing of masonry panels with irregular texture strengthened with inorganic composites

AbstractInorganic composites for enhancing the in-plane shear capacity of masonry walls with irregular texture were investigated on twenty-one panels under diagonal compression tests. Three specimens were used as control and twelve specimens were strengthened with two Fibre Reinforced Mortars (FRM-A and FRM-B), characterized by a different content of fibres embedded in the lime-based matrix. The remaining six specimens were strengthened with Fabric Reinforced Cementitious Mortars (FRCM), consisting in a GFRP grid embedded in a fibre reinforced matrix (the same used for FRM-A). The influence of single-side and double-side strengthening configurations on the capacity of strengthened panels was also investigated, to point out the reduction in strengthening effectiveness in case of single-sided applications. The results showed that all the inorganic composites adopted for the strengthening techniques provided a substantial increase of shear capacity. The grid in FRCM strengthened panels played an important role in both strength and deformation capacity at peak. The different fibres content (lower than 50% in weight) in FRM systems slightly affected the overall performance of panels. Finally, analytical predictions of experimental results were reported and discussed and a preliminary analytical model for estimating the FRM shear contribution was proposed, obtaining a good agreement with test results

Effect of buoyancy loads on the tsunami fragility of existing reinforced concrete frames including consideration of blow-out slabs

Currently available performance-based methodologies for assessing the fragility of structures subjected to tsunami neglect the effects of tsunami-induced vertical loads due to internal buoyancy. This paper adopts a generalized methodology for the performance assessment of structures that integrates the effects of buoyancy loads on interior slabs during a tsunami inundation. The methodology is applied in the fragility assessment of three case-study frames (low, mid and high-rise), representative of existing masonry-infilled reinforced concrete (RC) buildings typical of Mediterranean region. The paper shows the effect of modelling buoyancy loads on damage evolution and fragility curves associated with different structural damage mechanisms for existing RC frames with breakaway infill walls including consideration of blow-out slabs. The outcomes attest that buoyancy loads affect the damage assessment of buildings during a tsunami, especially in the case of mid and high-rise structures with blow-out slabs. The rate of occurrence of slabs uplift failure increases with the number of stories of the building, indicating the need to account for such damage mechanism when assessing the performance of structures. It is also found that buoyancy loads slightly affect the fragility curves associated to other structural damage mechanisms for existing RC buildings commonly monitored for fragility assessment

Assessing the effect of tsunami-induced vertical loads on RC frames

The increasing number of people, structures and economic activities being exposed to tsunami hazards makes it important to estimate the effects of this hazard on coastal developments. Tsunami onshore flow generates significant loading on buildings and infrastructure, which can lead to structural failure. Literature works recently proposed a non-linear static analysis method, called Variable Depth Pushover (VDPO), for assessing the performance of buildings under the lateral pressures induced by a tsunami onshore flow. This methodology was developed under the assumption that the building is watertight. However, in the case of buildings with breakaway cladding (e.g., masonry infills), the water flow passing through the building induces vertical loads on horizontal structural members, due to uplift and buoyancy pressures, that should be considered during the analysis. Thus, to address this phenomenon, in this paper a numerical investigation is performed considering a combination of tsunami-induced horizontal and vertical loads on a case-study reinforced concrete (RC) moment-resisting frame with breakaway infills, typical of Mediterranean construction. The building model is subjected to a VDPO analysis that applies different types and sizes of vertical loading on the horizontal elements of the building, as the tsunami inundation depth increases. From the results of this analysis, the effects of tsunamiinduced vertical load components on the case-study building in terms of damage propagation and failure mode are discussed, and the significance of considering vertical loading is proven