Analytical and numerical seismic assessment of heritage masonry towers

Abstract: The new Italian building code, published in 2018 [MIT in NTC 2018: D.M. del Ministero delle Infrastrutture e dei trasporti del 17/01/2018. Aggiornamento delle Norme Tecniche per le Costruzioni (in Italian), 2018], explicitly refers to the Italian “Guidelines for the assessment and mitigation of the seismic risk of the cultural heritage” [PCM in DPCM 2011: Direttiva del Presidente del Consiglio dei Ministri per valutazione e riduzione del rischio sismico del patrimonio culturale con riferimento alle norme tecniche per le costruzioni, G.U. n. 47 (in Italian), 2011] as a reliable source of guidance that can be employed for the vulnerability assessment of heritage buildings under seismic loads. According to these guidelines, three evaluation levels are introduced to analyse and assess the seismic capacity of historic masonry structures, namely: (1) simplified global static analyses; (2) kinematic analyses based on local collapse mechanisms, (3) detailed global analyses. Because of the complexity and the large variety of existing masonry typologies, which makes it particularly problematic to adopt a unique procedure for all existing structures, the guidelines provide different simplified analysis approaches for different structural configurations, e.g. churches, palaces, towers. Among the existing typologies of masonry structures there considered, this work aims to deepen validity, effectiveness and scope of application of the Italian guidelines with respect to heritage masonry towers. The three evaluation levels proposed by the guidelines are here compared by discussing the seismic risk assessment of a representative masonry tower: the Cugnanesi tower located in San Gimignano (Italy). The results show that global failure modes due to local stress concentrations cannot be identified if only simplified static and kinematic analyses are performed. Detailed global analyses are in fact generally needed for a reliable prediction of the seismic performance of such structures

COVID-19 in the tonsillectomised population

Objective: Interactions between SARS-CoV-2 and pharyngeal associated lymphoid tissue are thought to influence the manifestations of COVID-19. We aimed to determine whether a previous history of tonsillectomy, as a surrogate indicator of a dysfunctional pharyngeal associated lymphoid tissue, could predict the presentation and course of COVID-19. Methods: Multicentric cross-sectional observational study involving seven hospitals in Northern and Central Italy. Data on the clinical course and signs and symptoms of the infection were collected from 779 adults who tested positive for SARS-CoV-2, and analysed in relation to previous tonsillectomy, together with demographic and anamnestic data. Results: Patients with previous tonsillectomy showed a greater risk of fever, temperature higher than 39°C, chills and malaise. No significant differences in hospital admissions were found. Conclusions: A previous history of tonsillectomy, as a surrogate indicator of immunological dysfunction of the pharyngeal associated lymphoid tissue, could predict a more intense systemic manifestation of COVID-19. These results could provide a simple clinical marker to discriminate suspected carriers and to delineate more precise prognostic models

Research data supporting "Fresh state stability of vertical layers of concrete".

Spreadsheet (.xlsx) containing research data supporting "Fresh state stability of vertical layers of concrete". The following data are provided: • Mix composition of the mortars used in the experiments. • Densities of the mix constituents. • Experimental measurements for the mixes under investigations: density, spread length, yield stress, difference in yield stresses, sum of the yield stresses, stability coefficient, ratio between lower and higher yield stress, and maximum horizontal displacement of the interface between the two vertical layers of concrete. • Relationship between sum of the yield stresses, difference in densities of the materials, and average horizontal displacement obtained for each test. • Maximum horizontal displacement d as a function of the stability coefficient. • Analytical bound solutions and experimentally measured relationship between sum of the yield stresses, difference in densities of the materials, and average horizontal displacement obtained for each test. • Analytical bound solutions and experimentally measured maximum horizontal displacement as a function of the stability coefficient

Research data supporting "Interface bond strength of lightweight low-cement functionally layered concrete elements".

The spreadsheet (.xlsx) contains research data supporting the paper "Interface bond strength of lightweight low-cement functionally layered concrete elements" by Giacomo Torelli and Janet M. Lees (2020) in Construction and Building Materials, v. 249, 20 July 2020, 118614. This includes the data associated with: • Table 1 - Mix compositions, design density and strength of the virtual materials A, B1 and B2. • Table 2 - Delay between the castings of the external layer and the core section, and treatment of the interface for each specimen. • Table 3 - Mix compositions for the external and internal layers. *Superplasticizer content expressed in terms of % of cement mass. • Table 4 - Densities of the mix constituents. • Table 5 - Batches used for six layered-elements. • Table 6 - Fresh and hardened state properties of the different batches. • Figure 2 -Potential cement and weight savings for a beam with height h for various values of thickness t of the external layer, assuming h/b=2. • Figure 15 - Relationship between tensile strength and pour delay for layered specimens cut from top horizontal cores (HT1 and HT2), bottom horizontal cores (HB1 and HB2) and vertical cores (V1 and V2), (b) Relationship between tensile strength, pour delay and failure mode for layered cylinders cut from horizontal cores. • Figure 16 - Average tensile strength and (b) average tensile strength normalised with respect to the tensile strength of the weaker of the two materials versus pour delay. • Figure 18 - Maximum thickness of the external layer at the bottom of the element as a function of the pour delay. • Figure 19 - Composite graph: i) average tensile strength of the layered elements normalised with respect to the tensile strength of the weaker of the two materials versus pour delay, and ii) Rate of evolution* of heat of Portland cement with a water/cement ratio of 0.4 [46]. *The first peak of 3200 J/s kg is off the diagra

Setting for La Finta Pazza

Set design by Giacomo Torelli for Francesco Sacrati's opera La finta pazza as performed at the theatre in the Petit-Bourbon in Paris in 164

Overcoming real time bond in high level simulation environments

Overcoming Real Time Bond in High Level Simulation Environment

Nanoparticle-Enhanced Laser Induced Breakdown Spectroscopy for the noninvasive analysis of transparent samples and gemstones

In this paper, Nanoparticle-Enhanced Laser Induced Breakdown Spectroscopy is applied to transparent samples and gemstones with the aim to overcome the laser induced damage on the sample. We propose to deposit a layer of AuNPs on the sample surface by drying a colloidal solution before ablating the sample with a 532 nm pulsed laser beam. This procedure ensures that the most significant fraction of the beam, being in resonance with the AuNP surface plasmon, is mainly absorbed by the NP layer, which in turn results the breakdown to be induced on NPs rather than on the sample itself. The fast explosion of the NPs and the plasma induction allow the ablation and the transfer in the plasma phase of the portion of sample surface where the NPs were placed. The employed AuNPs are prepared in milliQ water without the use of any chemical stabilizers by Pulsed Laser Ablation in Liquids (PLAL), in order to obtain a strict control of composition and impurities, and to limit possible spectral interferences (except from Au emission lines). Therefore with this technique it is possible to obtain, together with the emission signal of Au (coming from atomized NPs), the emission spectrum of the sample, by limiting or avoiding the direct interaction of the laser pulse with the sample itself. This approach is extremely useful for the elemental analysis by laser ablation of high refractive index samples, where the laser pulse on an untreated surface can otherwise penetrate inside the sample, generate breakdown events below the superficial layer, and consequently cause cracks and other damage. The results obtained with NELIBS on high refractive index samples like glasses, tourmaline, aquamarine and ruby are very promising, and demonstrate the potentiality of this approach for precious gemstones analysis