Coalescing binaries as possible standard candles

Gravitational waves detected from well-localized inspiraling binaries would allow to determine, directly and independently, both binary luminosity and redshift. In this case, such systems could behave as "standard candles" providing an excellent probe of cosmic distances up to $z <0.1$ and thus complementing other indicators of cosmological distance ladder.Comment: 6 pages, 5 figures. accepted in Astroparticle Physic

From viability to sustainability: the contribution of the viable systems approach (VSA)

The current dynamics of business systems require new ways of conceiving the role of single entities. On this basis, a complex of interactions between the company and the reference context must be activated to guarantee survival dynamics. From these considerations re-emerge the ideas of Peccei (2013) and King (2013) that recognise in the systemic thought the foundations for a sustainable society. The present study derives from these considerations, and aims at contributing to the advancement of the knowledge necessary to overcome the challenges in the sustainability field. The methodological approach, albeit heuristic, can be traced back to the positive scientific and constructivist method. The results of the study showed the prevalence of qualitative and subjective techniques, accompanied by the so-called inductive method, testifying to the intense interaction between the scholar and the object investigated. With regard to future research, it would be interesting to construct a flexible, scalable and extensible model to recover both a database and an ontology for the theoretical framework

The inadequacy of regulatory frameworks in time of crisis and in low-resource settings : personal protective equipment and COVID-19

COVID-19 pandemic is plaguing the world and representing the most significant stress test for many national healthcare systems and services, since their foundation. The supply-chain disruption and the unprecedented request for intensive care unit (ICU) beds have created in Europe conditions typical of low-resources settings. This generated a remarkable race to find solutions for the prevention, treatment and management of this disease which is involving a large amount of people. Every day, new Do-It-Yourself (DIY) solutions regarding personal protective equipment and medical devices populate social media feeds. Many companies (e.g., automotive or textile) are converting their traditional production to manufacture the most needed equipment (e.g., respirators, face shields, ventilators etc.). In this chaotic scenario, policy makers, international and national standards bodies, along with the World Health Organization (WHO) and scientific societies are making a joint effort to increase global awareness and knowledge about the importance of respecting the relevant requirements to guarantee appropriate quality and safety for patients and healthcare workers. Nonetheless, ordinary procedures for testing and certification are currently questioned and empowered with fast-track pathways in order to speed-up the deployment of new solutions for COVID-19. This paper shares critical reflections on the current regulatory framework for the certification of personal protective equipment. We hope that these reflections may help readers in navigating the framework of regulations, norms and international standards relevant for key personal protective equipment, sharing a subset of tests that should be deemed essential even in a period of crisis

Local- and global-scale seismic analyses of historical masonry compounds in San Pio delle Camere (L`Aquila, Italy)

Masonry building aggregates are large parts of the Italian building heritage often designed without respecting seismic criteria. The current seismic Italian code does not foresee a clear calculation method to predict their static nonlinear behaviour. For this reason, in this paper firstly, a simple methodology to forecast the seismic response of masonry aggregates in San Pio delle Camere (L’Aquila, Italy) has been set up starting from the provisions of the Italian Guidelines on Cultural Heritage. The implemented procedure has been calibrated on the results of two FEM structural analysis programs used to investigate three masonry building compounds. As a result, a design chart used to correctly predict the base shear of aggregate masonry units starting from code provisions has been set up. Later on, the large-scale seismic vulnerability and damage appraisal of the inspected historical centre has been done on the basis of a quick methodology, already implemented and experienced by the author in some historical centres of the Campania region. The analysis result was a numerical correlation between vulnerability index and mean damage grade of examined building compounds. In particular, a damage forecast under numerical way has been firstly estimated and then compared with the real one. The post-earthquake scenario has represented an ideal term of comparison for effectively testing the reliability of the employed technique, which should be further extended to other Italian historical centres

Theoretical and Numerical Seismic Analysis of Masonry Building Aggregates: Case Studies in San Pio Delle Camere (L’Aquila, Italy)

Masonry building aggregates are large parts of the Italian building heritage often designed without respecting seismic criteria. The current seismic Italian code does not foresee a clear calculation method to predict their static nonlinear behavior. For this reason, in this article a simple methodology to forecast the masonry aggregate seismic response has been set up. The implemented procedure has been calibrated on the results of two FEM structural analysis programs used to investigate three masonry building compounds. As a result, a design chart used to correctly predict the base shear of aggregate masonry units starting from code provisions has been set up

Modeling of pv module and dc/dc converter assembly for the analysis of induced transient response due to nearby lightning strike

Photovoltaic (PV) systems are subject to nearby lightning strikes that can contribute to extremely high induced overvoltage transients. Recently, the authors introduced a 3D semi-analytical method to study the electromagnetic transients caused by these strikes in a PV module. In the present paper we develop an improved model of the PV module that: (a) takes into account high-frequency effects by modelling capacitive and inductive couplings; (b) considers the electrical insulation characteristics of the module; (c) includes the connection to a DC/DC converter. The whole process involves three major steps, i.e., the magnetic-field computation, the evaluation of both common-mode-and differential-mode-induced voltages across the PV module, and the use of the calculated voltages as input to a lumped equivalent circuit of the PV module connected to the DC/DC converter. In such a framework, the influence of the PV operating condition on the resulting electrical stresses is assessed; moreover, the relevance or insignificance of some parameters, such as the module insulation or the frame material, is demonstrated. Finally, results show that the induced overvoltage are highly dependent both on the grounding of the conducting parts and on the external conditions such as lightning current waveforms and lightning channel (LC) geometry

Seismic damage assessment of school buildings after 2012 Emilia Romagna earthquake

In the paper the usability checks performed on precast RC gyms and masonry school buildings, located in the Municipalities of San Pietro in Casale (BO), Bomporto (MO) and Bondeno (FE) after the seismic events occurred on 2012 May 20th and 29th, are reported and discussed. First, the main features of surveyed buildings have been identified. Later on, on the basis of the detected damages, their seismic deficiencies have been recognized. Finally, the indication of some appropriate simple interventions for retrofitting studied buildings has been given