An experimental investigation on the accuracy of dynamically determined tensile force in tie-rods by applying the interferometric radar technique was performed. Tie-rods were used in historical masonry constructions for absorbing thrusts of arches and vaults, and the radar interferometry may represent a fast and easy non-destructive approach for the tensile force identification in the occasion of structural assessments. Laboratory dynamic tests on a cable under a known tensile force show that, provided that a suitable dynamic identification model is used, tensile force evaluations made stating from interferometric radar measurements were characterized by a very good accuracy (mean error in the tensile force estimation less than 2%), comparable with evaluations made starting from accelerometric measurements. In particular, the dynamic identification model considered is a modified version of a model proposed in the literature. The influence on the accuracy in the determination of the tensile force of some features of the experimental setup, like, e.g., the employ of corner reflectors, is discussed.

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Background: Many studies previously reported epidemiological data on mortality due to COVID-19 among health workers. All these studies included a partial sample of the population with a substantial selection bias. The present study evaluates the trend of mortality among physicians and dentists operating in an area considered to be at high risk during the COVID-19 pandemic. Methods: Data relating to all physicians and dentists registered in the province of Pavia (Italy), a sample consisting of 5454 doctors in 2020 was analyzed. The mortality rates obtained were compared with those related to the 5-year period preceding the pandemic and with those related to the general population. Results: In the area considered, a mortality rate of 0.83% (+69% compared to 2015–2019) was observed in the entire sample in 2020 and 0.43% (−11% compared to 2015–2019) in 2021; among physicians, there was a mortality rate of 0.76% (+53% compared to 2015-2019) in 2020 and 0.35% (−29% compared to 2015–2019) in 2021; for dentists, there was a mortality rate of 1.27% (+185% compared to 2015–2019) in 2020 and 1.01% (+127% compared to 2015–2019) in 2021. Conclusions: These data report the global impact of the SARS-CoV-2 pandemic on physicians and dentists in a high-risk territory. In 2020, a significant increase in the mortality rate compared to the previous 5 years was observed for both physicians and dentists; in 2021, a significant increase in the mortality rate was observed only for dentists. These data are also significant in evaluating the impact of vaccination on physicians and dentists and indicate that dentists were among the professions most at risk during the pandemic.

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Modal testing is one of the most effective experimental techniques for the structural health monitoring of masonry constructions, as it provides useful information for the calibration of structural models and for the assessment of structural damage. However, the application of modal testing to masonry constructions is sometimes hindered by the complexity of the conventional experimental set-up, which is generally based on contact sensors. In order to overcome this issue, several researchers are exploring the application of the ground-based radar interferometry, which is an increasingly popular measurement technique for remotely monitoring displacement and vibration of structures. Given the recently increasing number of articles on this subject, here we propose a mini review on the most significant works dealing with the application of ground-based radar interferometry for modal testing of masonry constructions. In particular, we show the current state of the art and highlight the main research gaps with the purpose of assessing the effectiveness of ground-based radar interferometry for the structural health monitoring of these constructions. Our mini review is primarily aimed at engineers and scientists who already know about modal testing and radar interferometry technique and are interested in the specific application to masonry constructions.

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Masonry constructions compose the majority of the Architectural Heritage worldwide, thus, their preservation is of great importance. Nevertheless, they usually show a great vulnerability to seismic and dynamic loads. Several reinforcement techniques can be used in order to improve their dynamic behaviour. The Textile Reinforced Mortar (TRM) material appears as very suitable, since it meets the requirements of compatibility and reversibility of the retrofitting. Moreover, it avoids some problems related to permeability. And strongly reduces adhesion and debonding issues. In this paper the effectiveness of the TRM reinforcement for dynamic loads for windowed brick masonry walls is evaluated through vibration testing and operational modal analysis. To this aim, two scaled brick masonry walls were built at the "Laboratorio de Grandes Estructuras" of the University of Alicante. Only one of them was reinforced with the TRM. Both were damaged with a cyclic in-plane lateral force for simulating damage due to seismic actions. Structural vibrations of the two walls were measured in the presence of a white noise excitation. Modal parameters were evaluated through Operational Modal Analysis (OMA) before and after the damage. Finally, changes in modal parameters due to damage were compared and investigated in both the unreinforced and reinforced cases. The results suggest that TRM reinforcement can be considered effective for improving the mechanical behaviour of a brick windowed masonry wall.

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