Reduction of EMI susceptibility in CMOS bandgap reference circuits

This paper presents a successful approach to increase the electromagnetic interference (EMI) immunity of CMOS bandgap reference circuits. Layout techniques along with some changes in the reference schematics lead to a robust electromagnetic immunity, preserving good overall performances. Measurement results confirm the low susceptibility of the proposed circuits. They exhibit only a few millivolts shift, for interfering signals of 1 Vpp in the frequency range of 1 MHz to 4 GHz, compared to the classical topologies that may reach more than 1 V. The circuits were fabricated in a 0.8-ttm standard CMOS technology

Design of a 7.5 kW Dual Active Bridge Converter in 650 V GaN Technology for Charging Applications

High-voltage GaN switches offer low conduction and commutation losses compared with their Si counterparts, enabling the development of high-efficiency switching-mode DC-DC converters with increased switching frequency, faster dynamics, and more compact dimensions. Nonetheless, the potential of GaN switches can be fully exploited only by means of accurate simulations, optimal switch driving, suitable converter topology, accurate component selection, PCB layout optimization, and fast digital converter control. This paper describes the detailed design, simulation, and implementation of an air-cooled, 7.5 kW, dual active bridge converter exploiting commercial 650 V GaN switches, a compact planar transformer, and low ESL/ESR metal film capacitors. The isolated bidirectional converter operates at a 200 kHz switching frequency, with an output voltage range of 200-500 V at nominal 400 V input voltage, and a maximum output current of 28 A, with a wide full-power ZVS region. The overall efficiency at full power is 98.2%. This converter was developed in particular for battery charging applications, when bidirectional power flow is required

Restauro: Conoscenza, Progetto, Cantiere, Gestione

La SIRA, società scientifica che riunisce anzitutto coloro che, nelle università italiane, lavorano nel campo restauro, con i propri studi, la ricerca e l’insegnamento, ha l’obiettivo statutario di promuovere “lo studio e la valorizzazione del patrimonio culturale in ambito scientifico, accademico, civile ed educativo”. I volumi raccolgono i contributi al II Convegno tenutorsi a Bologna a settembre 2018 cui ha partecipato un consistente numero di studiosi in vario modo impegnati nell’Università italiana. L’intenzione fondamentale era fare luce sul rapporto esistente – o possibile – tra i molti aspetti che influenzano il ‘concreto fare restauro’ e che, nel loro articolarsi, possono determinare il successo o l’insuccesso delle attività che connotano il suo sviluppo: conoscenza, programmazione e fattibilità economica, progetto, cantiere e successiva gestione dei beni coinvolti

DISCOVERING AND COMMUNICATING THE RATIONALIST ARCHITECTURE OF FORLÌ. AN INTEGRATED PROCESS

A partnership between the Department of Architecture of the University of Bologna and ATRIUM aimed at enhancing the knowledge and communication of the rationalist architecture, built in the city of Forlì during the Fascist regime. The importance of finding an interpretative key for this dissonant heritage, bearers of an “uncomfortable” memory but at the same time able to strongly characterize the architectural quality of cities, was a primary goal.The cooperation started with the development of a pilot project regarding three architectures considered iconic for this context but also able to foster more complex urban policies. The first deliverable of the programme was the search, record, and management of the archival materials related to the whole history of these buildings. The enormous amount of data acquired revealed the importance of working on a dual track, aimed at both the stakeholders involved in the management process of this heritage and those who experience it.For what concerns the “technical level” which is related to the knowledge field, the first challenge was to understand how to manage information boosting interoperability, guaranteeing easy access and above all making the research implementable. According to the “touristic level” instead, a further objective of the project was related to the communication of this heritage to a varied audience of visitors.</p

ENVIRONMENTAL MICROCLIMATE MANAGEMENT AND RISK IN THE UNESCO WORLD HERITAGE SITE OF VILLA BARBARO MASER (ITALY)

Indoor environment in heritage buildings can be cause of damage for architecture and artefacts which depend on several physical and chemical parameters: air temperature, relative humidity, volatile organic compounds, etc. How is it possible to evaluate their damage, or the risk of damages? How “aggressive” is indoor microclimate? The scientific literature proposes several different criteria for the evaluation of the risk of damages, especially in the field of museums, while there are few studies which take into consideration historic buildings. In this paper we propose an index – the Heritage indoor Microclimate Risk (HMR) – that allows to define the risk concerning the whole environment and not only the artefacts. Moreover, we propose its application to a real case study of a UNESCO Heritage World Site, obtained through indoor microclimate on-site monitoring and building simulation. The case study reported is Villa Barbaro, built in Maser (1554–1560) by the architect Andrea Palladio and registered in the UNESCO World Heritage Site list since 1996, as Palladian Villa of Veneto. The research is structured as follows: monitoring campaign of the microclimatic parameters; virtual modelling of Villa Barbaro and its validation (by comparing the simulated data and the monitored ones); construction of scenarios which can aid to guarantee the historic building’s conservation and the occupants’ comfort; definition of HMR. The innovative aspect of the proposed methodology is the use of a virtual building model of heritage buildings, to determine, through a single index, the degree of risk and the level of indoor microclimate aggression

Che fare di Forte Marghera?

Forte Marghera, un imponente complesso di fabbriche, terrapieni e canali con un'estensione di 44 ettari, posta proprio in prossimità dell'attacco alla terraferma del ponte della Libertà (il ponte che collega Venezia alal terraferma), recentemente passato dal demanio militare al demanio comunale, rappresenta allo stesso tempo una straordinaria opportunità per la conurbazione di Venezia-Mestre e un problema di non facile soluzione. Nello scritto, esito dell'attività svolta negli anni precedenti dal Laboratorio integrato di Conservazione presso l'Università IUAV di Venezia, viene posto la questione di un metodo con il quale affrontare le questioni di progettazione dell'articolato complesso, a partire dall'individuazione delle cosiddette "funzioni compatibili"