Corona Influence on Lightning Induced Overvoltages in MOV Protected Multiconductor Power Lines

The effects of corona on amplitude and distortion of lightning overvoltages in three-phase MV lines is investigated. The line is protected by surgearresters whose characterstics can be planned taking into account real phenomena

Design and realization of a bidirectional full bridge converter with improved modulation strategies

In this paper a Full-Bridge Converter (FBC) for bidirectional power transfer is presented. The proposed FBC is an isolated DC-DC bidirectional converter, connected to a double voltage source—a voltage bus on one side and a Stack of Super-Capacitors (SOSC) on the other side. The control law aims at the regulation either of the bus current (when the load requires power) or of the SOSC current (when the stack requires a recharge). Analysis and design of the proposed FBC are discussed. A Phase Shift Modulation (PSM) scheme is proposed, along with an improved modulation variant for the efficiency optimization, through a proper reduction of the transformer power losses. The realized prototype, compliant with automotive applications, is presented and experimental results are highlighted. The target power level is 2 kW

Piezoelectric Rainfall Energy Harvester Performance by Advanced Arduino based Measuring System

This paper presents the performances of rainfall energy harvesting through the use of a piezoelectric transducer and an Arduino-based measuring system. Different studies agree on the possibility of generating electricity from rainfall, but to date, a study on measuring the quantity of energy produced during rainfall is still missing. The present study begins with results obtained from laboratory researchers using piezoelectric transducers and oscilloscopes, finalized to measure the energy produced from a single raindrop, and concludes with an ad hoc Arduino-based measuring system, aimed to measure the actual amount of electrical energy produced by a piezoelectric transducer that is exposed to rainfall of variable durations

Application of the Maximum Power Extrapolation Procedure for Human Exposure Assessment to 5G Millimeter Waves: Challenges and Possible Solutions

This paper describes an investigation on the application of the Maximum Power Extrapolation (MPE) technique on a fully operational Fixed Wireless Access (FWA) FR2-band 5G gNB. The data was acquired in [27.1-27.3] GHz band using a network scanner over nearly 10 minutes periods to allow a statistical analysis and an accurate estimation of the role of each contribution to the total uncertainty, including the fading affecting the 5G FR2 reference signal. The results show that the level of the electromagnetic field is well below the limits imposed by Italian legislation. However the goal of the paper is more fundamental, and shows an approach that can be used to identify the critical elements of the measurement set-up, suggesting where to concentrate efforts to improve the measurement procedure. In particular, the uncertainty budget highlights three contributions, (i.e. estimation of the traffic beam level, of the probe response and of the 5G FR2 reference signal) that deserve further investigations

Birth of an ocean in the Red Sea: Initial pangs

We obtained areal variations of crustal thickness, magnetic intensity, and degree of melting of the sub- axial upwelling mantle at Thetis and Nereus Deeps, the two northernmost axial segments of initial oceanic crustal accretion in the Red Sea, where Arabia is separating from Africa. The initial emplacement of oceanic crust occurred at South Thetis and Central Nereus roughly $2.2 and$2 Ma, respectively, and is taking place today in the northern Thetis and southern Nereus tips. Basaltic glasses major and trace element com- position suggests a rift-to-drift transition marked by magmatic activity with typical MORB signature, with no contamination by continental lithosphere, but with slight differences in mantle source composition and/or potential temperature between Thetis and Nereus. Eruption rate, spreading rate, magnetic intensity, crustal thickness and degree of mantle melting were highest at both Thetis and Nereus in the very initial phases of oceanic crust accretion, immediately after continental breakup, probably due to fast mantle upwelling enhanced by an initially strong horizontal thermal gradient. This is consistent with a rift model where the lower continental lithosphere has been replaced by upwelling asthenosphere before continental rupturing, implying depth-dependent extension due to decoupling between the upper and lower lithosphere with man- tle-lithosphere-necking breakup before crustal-necking breakup. Independent along-axis centers of upwell- ing form at the rifting stage just before oceanic crust accretion, with buoyancy-driven convection within a hot, low viscosity asthenosphere. Each initial axial cell taps a different asthenospheric source and serves as nucleus for axial propagation of oceanic accretion, resulting in linear segments of spreading

Identifying the 993-994 CE Miyake event in the oldest dated living tree in Europe

Combined dendrochronology and accelerator mass spectrometry radiocarbon (AMS 14C) dating analyses were used in order to date an old living tree named Italus, growing in the Pollino massif in Southern Italy. Wiggle match AMS 14C dating analysis was performed on a 320-yr-long floating chronology obtained by cross-dating four wood cores extracted from the exposed roots of the tree. Following this approach, an age for the tree of ≈1230 yr was estimated. This age makes Italus the oldest living tree in Europe. High-resolution 14C dating analyses performed on single rings extracted from the tree stem allowed us to identify the 993.994 CE large excursion in atmospheric 14C concentration (Miyake event) revealing for the first time its presence in the Mediterranean basin

Early versus delayed endoscopic treatment of acute pilonidal abscess: a propensity score-matched analysis

Background: According to the Italian Society of Colorectal Surgery guidelines, the most effective approach to the pilonidal abscess is adequate surgical drainage, concerning incision and drainage of the pilonidal cavity. Few recent studies have demonstrated that endoscopic approach could be a valid treatment option even in the case of acute pilonidal abscess. The aim of our study is to assess if video-assisted ablation of pilonidal sinus (VAAPS) could be an alternative to treat an acute pilonidal abscess and to evaluate if an immediate endoscopic approach to the pilonidal abscess is preferable to a delayed procedure after incision and drainage. Methods: All consecutive patients with an acute pilonidal abscess since 1 January 2014 to 31 December 2018 were enrolled in our propensity score-matched analysis and divided into two groups: the early VAAPS group and the delayed VAAPS group. Primary outcomes were recurrence rate at 1-year, 3-year, and 5-year follow-up. Secondary outcomes were time off, time to wound healing, incomplete wound healing, perioperative infection, patients’ satisfaction 1 month after the complete wound healing, and their health status before surgery and 6 months after complete wound healing. Results: After the propensity score matching, 82 patients were included in the final analysis (41 in each group). No differences were found in terms of recurrence in the two groups. Early endoscopic approach was associated with a better patients’ satisfaction (8.17 ± 1.2 vs 6.06 ± 1.48, p = 0.001) and a better postoperative health status (86.27 ± 6.54 vs 77.32 ± 5.85, p = 0.001). Conclusions: Our results encouraged to perform an immediate endoscopic approach to an acute pilonidal abscess