Indoor radon survey in university buildings: a case study of Sapienza - University of Rome

The indoor radon concentration in underground workplaces pertaining to Sapienza – University of Rome have been monitored since the 90’s according to prescription of Italian Legislative Decree 230/95. In the last years, the recommendations contained in the Council Directive 2013/59/Euratom have shifted the focus to all indoor exposure situations by promoting actions to identify workplaces and dwellings with radon concentrations exceeding the reference level of 300 Bq/m3. In response to the upcoming transposition into national legislation, Sapienza has promoted the first Italian survey addressing workplaces in university buildings, regardless of the position with respect to the ground floor. The survey has interested more than three hundred workplaces, i.e. administration and professors’ offices, research and educational laboratories, conference rooms and classrooms, distributed in fifteen different buildings. Places monitored are strongly heterogeneous in terms of users’ habit, occupancy pattern and building characteristics. The influence of these parameters into seasonal variation have been addressed by organizing the survey in four quarters. The indoor radon concentration is measured by solid state nuclear track detectors, CR39. The aim of the paper is to present features, methods and intermediate results of the survey. The work, relying on the analysis of previous measurements interesting underground workplaces, focuses on methodology followed during all the preliminary and preparatory phases: active measurements by ionization chamber radon continuous monitor, radon progeny equilibrium factor estimations by radon daughters monitor, strategies for occupants’ awareness, positioning protocol and provisions to maximize representativity of results

Epistemic stance without epistemic modals: the case of the presumptive future

This paper deals with the non-temporal use of the future in Italian known as "epistemic" or "presumptive" (PF) in declaratives and interrogatives. We first distinguish PF from epistemic necessity and possibility, as well as from weak necessity modals, providing in the process the main empirical challenges PF raises. We then propose and justify a semantic account that treats PF as a special normality modal that involves a subjective likelihood component. Since in our account the prejacent (the proposition in the scope of the modal) is at issue, the use of PF triggers the implicature that the speaker is not in a position to appeal to what she knows in order to support her commitment to the prejacent. This, we claim, is the source of the intuition that PF is often used to offer a “guess” relative to the question under discussion (QUD)

Improving angle stability by switching shunt reactors in mixed overhead cable lines. An Italian 400 kV case study

Stringent environmental constraints make the construction of new transmission overhead lines more and more difficult. Alternatively, today it is possible to use cable lines for high (HV) and extra-high (EHV) voltage systems. The configuration of the so-called mixed lines can create some problems in the operation of the electrical system, both during steady-state and transient conditions. In particular, the system stability is one of the main concerns when analyzing the dynamic response of power systems. In this paper, the study of angular stability of a system containing a mixed line is presented: a specific control logic applied to the shunt reactors of the mixed line is proposed as improvement of the overall system stability. The proposed switching logic is first discussed from a theoretical point of view and validated with two different testing systems. Then, the existing overhead-cable lines connecting Sicily to the rest of continental Europe 400 kV power system are taken as case study for the application of the proposed switching strategy. Several simulations are performed in the power system analysis software NEPLAN360: the results show the fundamental role of the timing of the control actions applied on the shunt reactors in helping the system to keep the stability. The proposed control proves to be an effective support to the system subjected to critical contingencies, contributing decisively to avoid the angular separation between areas and therefore to preserve the stability of the system

Employability skills: Profiling data scientists in the digital labour market

In the current scenario, data scientists are expected to make sense of vast stores of big data, which are becoming increasingly complex and heterogeneous in nature. In the context of today's rapid technological development and its application in a growing array of fields, this role is evolving simultaneously. The present study provides an insight into the current expectations of employers seeking to hire individuals with this job title. It is argued that gaining a better understanding of data scientists’ employability criteria and the evolution of this professional role is crucial. The focus is placed on the desired prerequisites articulated through job advertisements, thus deriving relevant means for furthering theory and practice. It was achieved by harvesting relevant data from job advertisements published on US employment websites, which currently attract the US market's highest recruitment traffic. The key contribution of this study is to have identified means of systematically mapping skills, experience, and qualifications sought by employers for their data scientists, thus providing a data-driven pathway for employability and avoiding skills gaps and mismatches in a profession that is pivotal in the Industry 4.0

Isolated Paralysis of the Adductor Pollicis: A Case Report

We report a case of isolated paralysis of the right adductor pollicis in a 30-year-old woman. Electromyographic study showed involvement of the deep motor branch of the ulnar nerve. A ganglion and an anomalous muscle were both ruled out clinically and by MRI as a possible cause of the paralysis. At surgical exploration, we found a fibrous band joining the pisiform and the hook of the hamate bone that compressed the deep motor branch of the ulnar nerve. The fibrous band was excised, and a neurolysis of the motor branch of the ulnar nerve was performed. At followup, eight months later, the patient had fully recovered strength of the adductor muscle

An original control strategy of storage systems for the frequency stability of autonomous grids with renewable power generation

This work examines the operation of the autonomous power system of a geographical island assuming the integration of significant generation shares from renewable energy sources and the installation of the required storage systems. The frequency stability of the system is investigated considering different operating conditions, in terms of load demand and renewable power generation. The main focus of the work is an original control strategy specifically designed for power converters interfacing storage units to the grid. The proposed strategy is based on an extended frequency droop control, which selects specific droop settings depending on the operating mode—charge or discharge—of the storage unit. A simulation model of the whole electrical system is developed for dynamic analysis. The model also implements the possibility of including specific auxiliary frequency controls for synthetic inertia and primary reserve. The results of the simulation and analysis indicate that the proposed control strategy has a significant positive effect, making the storage units able to provide a fundamental and more effective support to the frequency stability of the system. The application of the proposed control strategy to storage units also reduces the need for a contribution to the frequency control from intermittent and variable sources, making the whole system more robust, stable and reliable

The Wide-Synchronization Control at Support of the Oscillatory Stability of Power Systems

The wide-synchronization control is a novel wide-area control involving inverter-based resources as actuators. The concept is based on the determination of a remote frequency signal, which can be used within the control systems of the converters participating in the control. In this paper, the concept of the wide-synchronization control is investigated as solution to effectively improve the oscillatory stability of the system. The results indicate that the proposed concept is capable to provide a decisive contribution in preserving the system stability, even under severe critical condition