Archivio istituzionale della Ricerca - Università degli Studi di Parma
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Performance Analysis of a Custom DC-DC Buck Converter for Smart Plug Applications in Nanogrids
No full textTo improve power management systems in micro- and nanogrid applications, it is crucial to thoroughly evaluate the efficiency, output ripple, and operating frequency of DC-DC converters. This paper presents a detailed investigation of these critical parameters for custom laboratory-built DC-DC buck converters with Gallium Nitride (GaN) transistors. The study analyses and compares measurements to assess the converter's performance under varying load conditions. Efficiency is examined by varying input voltages and load levels to unveil the converter's operational boundaries. The investigation extends to the characterization of the output ripple. Furthermore, the impact of working frequency on both characteristics and design requirements is explored, providing insights into optimal frequency selection. A comparative analysis with industry-standard benchmarks underscores the converter's strengths and areas for improvement. This study not only contributes to the advancement of DC-DC converter design methodologies but also provides practical insights for enhancing power management efficiency in Smart Plug applications within micro- and nanogrid environments
Effect of the surface morphology of 3D printed titanium substrates on the mode I fracture toughness of metal-metal and metal-composite bonded joints
No full textParts manufactured with Laser Powder Bed Fusion (LPBF) are drawing interest in the adhesive joints research because of their high surface roughness, which is usually associated with good adhesion. This work aims to assess the adhesion strength of the inherent surface morphology of LPBF manufactured titanium. Double Cantilever Beam (DCB) tests were carried out to determine the mode I fracture toughness of joints comprising as-printed titanium (Ti6Al4V) adherends, namely titanium-titanium secondary bonded and titaniumCarbon Fibre Reinforced Polymer (CFRP) co-bonded joints. The effect of high-temperature oxidation on the fracture toughness was also evaluated by testing a batch of joints in which the titanium underwent a postprinting thermal treatment. The as-printed specimens were compared to the same type of joints but with sandblasted titanium adherends to evaluate the effect of this surface pre-treatment on the value of fracture toughness. The results indicate that non-oxidised titanium joints with untreated adherends had an average of 11% higher fracture toughness than their sandblasted counterparts. On the other hand, sandblasting proved beneficial for oxidised joints, increasing the fracture toughness by 64% on average over the untreated samples
The Chiral 5,6-Cyclohexane-fused Uracil Ring-System: a Molecular Platform with Promising Activity against SARS-CoV-2
No full textThe recurrent global exposure to highly challenging viral epidemics, and the still limited spectrum of effective pharmacological options step on the accelerator towards the development of new antiviral medicines. In this work we explored the anti-SARS-CoV-2 potential of a recently launched chiral ring system based on the uracil scaffold fused to carbocycle rings. The asymmetric synthesis of two generations of chiral uracil-based compounds (overall 31 different products), and their in vitro cytotoxicity and antiviral screening against wildtype SARS-CoV-2 in U87.ACE cells allowed us to identify seven non-cytotoxic enantioenriched derivatives exhibiting in vitro EC50 in the 6-37 microM range. Among these compounds, bicyclic uracil 10 showed the best antiviral potency against SARS-CoV-2 (EC50 20A.EU2 = 7.41 microM and EC50 Omicron = 19.4 microM), combined with a favourable selectivity index. Additionally, it exhibited single-digit micromolar inhibition of the isolated SARS-CoV-2 RNA-dependent RNA polymerase (IC50 = 2.1 microM). Starting from a reported cryo-EM structure of RdRp, docking and molecular dynamics simulations were performed to rationalize possible binding modes of the active compounds. Interestingly, no inhibition of viral replication in cells was observed against a wide
spectrum of human viruses, while some derivatives, and especially hit compound 10, exhibited specific low micromolar antiviral effect against beta-coronavirus OC43. Collectively, these data indicate that this novel uracil based ring system represent a valid starting point for further development of a new class of RdRp inhibitors to treat SARS-CoV-2 and, potentially, other beta-coronavirus infections
A Wearable Microphone Array Helmet for Automotive Applications
No full textFeatured Application: Development of immersive infotainment and ANC systems in the automotive industry with Ambisonics audio. Growing interest in microphone array technology has been observed in the automotive industry and in this work, specifically, for Active Noise Control (ANC) systems. However, the human presence always limits the usage of microphone arrays in driving conditions at the driver’s seat. This is often the most important position of the car cabin; a wearable microphone array is particularly interesting. In this paper, a wearable helmet microphone array is presented featuring 32 microphones arranged over the surface of a helmet, which also integrates a specially designed Analog-to-Digital (A/D) converter, delivering digital signals over the Automotive Audio Bus (A2B). Digital signals are collected using a control unit located in the passenger compartment. The control unit can either deliver digital signals to a personal computer or analog signals to an external acquisition system, by means of Digital-to-Analog (D/A) converters. A prototype was built and acoustically characterized to calculate the beamforming filter matrix required to convert the recordings (pressure signals) into Ambisonics signals (a spatial audio format). The proposed solution was compared to the reference spherical microphone array of the last decade, demonstrating better performance in sound source localization at low frequencies, where ANC systems are mostly effective
Ecologie degli ambienti urbani: sfide applicative/Ecologies of Urban Environments: Challenges in Applying Anthropology
No full textPR050 verso il Piano Urbanistico Generale di Parma. Obiettivi e strategie
No full textIl PUG di PARMA prende spunto dalle principali sfide del ventunesimo secolo e ci porta ad immaginare la città del futuro: una città fatta di relazioni e socialmente inclusiva, una città produttiva ma anche una città verde e sostenibile. Una città in cui lo spazio pubblico è al centro della vita di chi la vive e frequenta.
Inoltre, siamo oggi di fronte a sfide ambientali, climatiche, economiche e sociali urgenti ed obiettivi ambiziosi, che richiedono soluzioni progettuali altrettanto ambiziose per poter arrivare ad una città completamente decarbonizzata entro il 2050; un futuro che è
in realtà dietro l’angolo
A preliminary study on the effects of rainfall-related conditions on chromium increase in ultramafic-hosted springs: A possible climate change concern?
No full textThis study investigates the impact of intense rainfall on chromium concentrations in five springs discharging from ultramafic rocks in the Northern Apennines (Italy), which are used for drinking water supply through integration into the local water network. Total chromium concentration increased significantly in response to heavy rain, exceeding the WHO drinking water guideline value (up to 80 μg/L) in one spring and the forthcoming 2036 EU target of 25 μg/L in all the springs. This increase could be attributed to a synergistic combination of factors: i) the reduction of Cr(VI) to Cr(III) by natural organic matter (NOM) in soil and transport as NOM-Cr(III) colloids and/or during the oxidation of magnetite to ferrihydrite in the aquifer; ii) the abundance of detrital ultramafic material in the study area, which may store Cr(III)-bearing colloids too; iii) a triggering effect of first intense rainfall after a 20 dry consecutive days period (wet-dry cycle). Moreover, the persistence of a high Cr(III) concentration in the aquifer even a month after the intense rainfall event aligns with previous laboratory studies on NOM-Cr(III) colloidal stability, which showed that such colloids are highly stable and can persist in solution for at least 20 days
Urban Gothic and Anthropocenic Darkness in James Thomson (‘B.V’.)’s "The City of Dreadful Night"
No full textJames Thomson’s The City of Dreadful Night (1874) has been interpreted through multiple critical lenses. Scholars have variously examined it as a vision of psycho-geographic horror, an example of Urban Gothic, a pre-Modernist Waste Land, a Dantesque allegory of the human condition, a metaphor for London, and a reflection of the poet’s unconscious fears, insomniac nights, and existential despair. This essay offers a fresh perspective on this masterpiece, reconsidering these interpretations through the lens of contemporary debates on the Anthropocene and environmental anxieties. In this reading, Thomson’s nocturnal city becomes an eerily prescient image of a world ravaged by human greed, anthropocentric exploitation, and ecological indifference, while its inhabitants embody a stoic resistance to the moral failures of modern civilization. Ultimately, this chapter argues that Thomson’s vision remains strikingly relevant today, exposing the persistent disregard for environmental and social justice — both human and more-than-human. Yet, even within this overwhelming darkness, his work may offer a faint but significant glimmer of consolation
Europe and the Roman Curia: Conflicts of the Counter Reformation
No full textThe Roman Curia will be analyzed as an international agency capable of acting not so much as the head of a powerful machine, but as the place of confluence, listening and governing of local conflicts coming from the European multi-denominational space, and above all of managing structural conflicts within the Catholic Church.
The essay considers the period between the Peace of Augsburg in 1555 and the end of the Thirty Years' War (1648), with particular attention to the institutional diplomatic channels (nuncios and apostolic legates) and the international activity of the regular orders before and after the creation (1622) of the cardinal Congregation of Propaganda Fide