196,191 research outputs found
La montagna della Sibilla. Introduzione
No full textIl testo introduce il testo di M. Vaquero Piñeiro dedicato ad una profonda riflessione sulle caratteristiche del territorio dell'Appennino centrale e il suo sviluppo nel corso degli ultimi secoli, in cui queste terre sono state martoriate da terremoti, conseguenti crisi economiche e progressivo abbandono. Nell'Introduzione si rimarcano gli effetti devastanti del sisma, non solo sull'organizzazione economica, sulla struttura sociale, ma anche sulla psiche degli abitanti, sulla loro identità, segnando profondamente le comunità. Ma nello stesso tempo il sisma può essere capace di mostrare anche la fora di una comunità che resiste, adattandosi e modificando pratiche e saperi per costruire nuove forme di resilienza
Introduzione. Per una diversa prospettiva
No full textIl saggio contiene gli Atti del III Convegno di Armonie Composte tenutosi presso l'Abbazia di Praglia il convegno è dedicato alla martoriata realtà del Centro Italia colpita ancora una volta dal sisma. L'introduzione spiega le ragioni delle riflessioni maturate in quel consesso focalizzate non solo sulla natura del sisma, le sue conseguenze o sulle possibili politiche di messa in sicurezza dei territori e delle comunità, quanto ha voluto essere un'occasione per riaffermare la necessità di un’innovativa prospettiva multidisciplinare, intersettoriale che permetta di osservare, analizzare criticamente e comprendere gli effetti delle calamità naturali. Con la volontà di contribuire alla costruzione di una diversa consapevolezza con cui affrontare terremoti ed altri disastri (basati non solo su presupposti di contenuto tecnico-scientifico ma anche su azioni in grado di far leva sui fattori sociali e culturali, esplorando in modo ampio e completo gli impatti che i terremoti procurano
sull’ambiente costruito come sulla struttura sociale nel suo complesso, sulle comunità, sui gruppi sociali e familiari), i diversi contributi vogliono dare spunto ad una riflessione che possa condurre ad una diversa filosofia di intervento nelle terre colite dal sisma.
Il saggio in questione oltre a voler restituire il fil rouge che ha guidato la costruzione dell'iniziativa ed i contenuti dei diversi contributi raccolti, vuole soprattutto persuadere della validità di un diverso approccio all'emergenza e soprattutto indagare le modalità di costruzione non solo di una maggiore consapevolezza collettiva per la prevenzione, ma piuttosto la creazione di una particolare "resilienza" delle comunità locali perché il sisma non sia più causa di ulteriori forme di disgregazione sociale e sradicamento territoriale
Latch-up DC triggering and holding characteristics of n-well, twin-tub and epitaxial CMOS technologies
No full textThe dependence of the latch-up susceptibility on layout parameters is studied on four stripe structures made using different CMOS processes: a standard n-well, a twin-tub and twin-tub epitaxial technology. The correlation between triggering currents, well and substrate resistances and parasitic transistor gains is studied by means of emitter current triggering measurements and two-dimensional simulations using HFIELDS. Triggering currents higher than 250 mA are obtained on epitaxial structures with n+ guard-rings. Anomalies in triggering and holding electrical characteristics are caused by the three-dimensional distribution of the latch-up current, which is observed by IR microscopy. These anomalies can affect results of conventional latch-up testing method
Effects of Radio Frequency Interference in OPAMP Differential Input Stages
No full textThe paper deals with the problem of RFI induced output dc offset in operational amplifiers. In particular, it presents an extended analysis of the effect of the input differential stage nonlinearity in the generation of the output voltage offset. Differently from previously presented analyses, the proposed approach allows to take into account the effects of non purely square-law device models, e.g. including also velocity saturation effects. The paper also analyzes the common emitter differential input pair the analysis results can be easily extended to represent sub-threshold biased MOSFET differential stages. Based on the proposed analytical approach the paper discusses two very simple design provisions that mitigate the RFI effects. Design trade-offs related to these solutions are discussed. The proposed solutions are validated by simulations
Effects of RFI and Underground Currents on a Smart Power Bandgap Voltage Reference
No full textThe effects on a band gap voltage reference circuit of a radio frequency conducted disturbing signal superimposed to the supply voltage are evaluated. The variations of the dc output voltage are investigated for different frequency and amplitude of the interfering signal. A dedicated PCB for the measurements is developed paying attention to careful HF layout. Also, the impact of substrate currents on the IC’s behaviour is studied. The paper gives an analysis of the results obtained by measurements and simulation, focusing on the key macroscopic effects. A good agreement between simulations and measurements is found. At the end, a modified schematic based on simulation results is proposed to improve the immunity of the bandgap circuit
Effects of RFI and Underground Condition on PWM Current-Mode Integrated Circuits for SMPS
No full textThe effects of a radio frequency conducted disturbing signal are evaluated on several pin-to-pin compatible control integrated circuits (IC) for PWM current-mode switching power supplies. The tested ICs were selected between some common models available on the market. The variations of the primary functional parameters (inner voltage reference, switching frequency, etc.) are investigated in conditions of different frequency and amplitude for the interfering signal. A dedicated PCB for the measurements was developed paying particular attention to HF layout. Also, the impact of underground condition (voltage at one pin below ground reference) on ICs’ behaviour is analysed. The paper gives a comparative view of the results, focusing on the key macroscopic effects
Antibodies against Receptor Binding Domain of SARS-CoV-2 spike protein induced by BNT162b2 vaccine: results from a pragmatic, real-life study
No full textBackground: As part of the fight against SARS CoV2 infection, vaccination program for health workers at Giannina Gaslini pediatric hospital (IGG) in Genoa, Italy, started on December 2020. We evaluated the anti-Spike protein response in healthcare workers after a complete vaccination scheme of 2 doses spaced by 3 weeks. Methods: Immunoglobulin class G (IgG) against SARS-CoV-2 spike RBD were detected by means of a chemiluminescence immunoassay for quantitative IgG antibodies using Maglumi SARS-CoV-2-S-RBD IgG kit during the 3rd week after vaccination completion. Results: IgG anti SARS-CoV-2 spike protein were detected in 99.88% of 1765 healthcare workers 3 weeks after 2nd dose of BNT162b2. Higher median IgG values were observed in younger subjects (807 UA/mL in under 30 vs 429 UA/mL in over 60; p < 0.001) and those with previous COVID-19 (1284 vs 574 UA/mL; p < 0.001). Conclusion: BNT162b2 is effective in inducing anti SARS-CoV-2 antibodies even in real-life setting. The higher antibody title observed in workers with a previous documented SARS CoV2 infection confirms the possibility to carry out only one dose of BNT162b2 in a context of vaccines shortage
Susceptibility of Integrated Circuits to RFI: Analysis of PWM Current-Mode Controllers for SMPS
No full textThis paper deals with the analysis of the effects of radio frequency conducted interfering signals (RFI) on integrated circuits (ICs). After reviewing the basic results of the susceptibility analysis of operational amplifiers and smart power integrated circuits, the behavior of several pin-to-pin compatible control ICs for PWM current-mode switching power supplies (SMPS) has been tested in the presence of both continuous wave interfering signals (CW) as well as of pulsed noise signals (underground condition). The tested ICs were selected between some common models available on the market. The variations of the primary functional parameters (inner voltage reference, switching frequency, etc.) are evaluated in different test conditions. The paper gives a comparative view of the results, focusing on the key macroscopic effects
Susceptibility of Integrated circuits to RFI: analysis of PWM current-mode controllers for snips
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