Attività svolta nell’ambito delle verifiche di agibilità nella provincia de L’Aquila e considerazioni sulle registrazioni accelerometriche del 06/04/2009

Nel presente articolo si illustra l’attività svolta dagli Autori nell’ambito delle verifiche di agibilità. In N. 5 - 2009 13 particolare tra tutti gli edifici esaminati ne sono stati selezionati tre, uno per tipologia strutturale (c.a., c.a.p. e muratura), ritenuti più rappresentativi. Si fornisce poi un breve resoconto della situazione riscontrata a Castelnuovo, una delle Località maggiormente colpite. Vengono inoltre date delle indicazioni preliminari sulla risposta del costruito, in base a quanto osservato sul campo ed in base ad alcune valutazioni che è già possibile fare sulle registrazioni accelerometriche del 06/04/2009. L’evento sismico in oggetto è stato inquadrato nella storia sismica del territorio de L’Aquila e messo in relazione con i terremoti più significativi verificatisi in Italia negli ultimi decenni: Friuli 1976, Irpinia 1980, Umbria– Marche 1997, Molise 2002. Infine si è proceduto ad un confronto con l’azione sismica prevista dall’attuale Normativa (D.M. LL.PP. del 14/01/2008 [3] e relativa C.M. LL.PP. N. 617 del 02/02/2009 [4]), confronto dal quale non può prescindere una lettura critica del grado di danneggiamento prodotto sulle diverse tipologie strutturali

Out-of-plane capacity of cladding panel-to-structure connections in one-story R/C precast structures

AbstractThe interaction between cladding panels and the main structure is a crucial point to assess the seismic response, and above all the structural safety, of RC precast industrial building. In the past, connections were often designed to allow construction tolerances and to accommodate both thermal and wind-induced displacements. The lack of specific details to allow relative in-plane displacements between cladding panels and the main structure often led to the participation of cladding panels in the structure seismic-resistant system with consequent connection failures. In the last decades, a lot of experimental tests were performed to investigate the in-plane performance of panel connections, and some design recommendations have been developed accordingly. In the out-of-plane direction, the connections were often considered to be infinitely rigid and not to suffer any damage by the seismic load. This work deals with the out-of-plane response of panel-to-structure connections for vertical panels typical of industrial and commercial precast buildings. Both standard hammer-head strap and new devices, called SismoSafe, were investigated. Tests were performed in the Structures and Materials Testing Laboratory of the Department of Civil and Environmental Engineering of Florence, where a specific setup was designed to perform cyclic and monotonic tests on the connection devices. Standard connections showed a rather limited resistance, while the innovative connections exhibited a high out-of-plane resistance. Numerical analyses were also performed on a case study building to evaluate the distribution of the out-of-plane demand on the connections

A setup for soft proton irradiation of X-ray detectors for future astronomical space missions

Protons that are trapped in the Earth's magnetic field are one of the main threats to astronomical X-ray observatories. Soft protons, in the range from tens of keV up to a few MeV, impinging on silicon X-ray detectors can lead to a significant degradation of the detector performance. Especially in low earth orbits an enhancement of the soft proton flux has been found. A setup to irradiate detectors with soft protons has been constructed at the Van-de-Graaff accelerator of the Physikalisches Institut of the University of T\"ubingen. Key advantages are a high flux uniformity over a large area, to enable irradiations of large detectors, and a monitoring system for the applied fluence, the beam uniformity, and the spectrum, that allows testing of detector prototypes in early development phases, when readout electronics are not yet available. Two irradiation campaigns have been performed so far with this setup. The irradiated detectors are silicon drift detectors, designated for the use on-board the LOFT space mission. This paper gives a description of the experimental setup and the associated monitoring system.Comment: 20 pages, 10 figures, 4 table

The future direction of imaging in prostate cancer: MRI with or without contrast injection

Background: Multiparametric MRI (mpMRI) is the "state of the art" management tool for patients with prostate cancer (PCa) suspicion. The role of non-contrast MRI is investigated to move toward a more personalized, less invasive, and highly cost-effective PCa diagnostic workup. Objective: To perform a non-systematic review of the existing literature to highlight strength and flaws of performing non-contrast MRI, and to provide a critical overview of the international scientific production on the topic. Materials and methods: Online databases (Medline, PubMed, and Web of Science) were searched for original articles, systematic review and meta-analysis, and expert opinion papers. Results: Several investigations have shown comparable diagnostic accuracy of biparametric (bpMRI) and mpMRI for the detection of PCa. The advantage of abandoning contrast-enhanced sequences improves operational logistics, lowering costs, acquisition time, and side effects. The main limitations of bpMRI are that most studies which compared the non-contrast and contrast MRI come from centers with high expertise that might not be reproducible in the general community setting; besides, reduced protocols might be insufficient for estimation of the intra- and extra-prostatic extension and regional disease. The mentioned observations suggest that low quality mpMRI for the general population, might represent the main shortage to overcome. Discussion: Non-contrast MRI future trends are likely represented by PCa screening and the application of artificial intelligence (AI) tools. PCa screening is still a controversial topic and bpMRI, and has become one of the most promising diagnostic applications, as it is a more sensitive test for PCa early detection, compared to serum PSA level test. Also, AI applications and radiomic have been the object of several studies investigating PCa detection using bpMRI, showing encouraging results. Conclusion: Today, the accessibility to MRI for early detection of PCa is a priority. Results from prospective, multicenter, multireader and paired validation studies are needed to provided evidence supporting its role in the clinical practice