Luigi G. Jacchia, un triestino a Bologna: dai cieli di Loiano all'epopea spaziale americana.

In questa tesi di laurea si vuole parlare della vita di Luigi Giuseppe Jacchia (1910-1996), un astronomo italo-americano del secolo scorso che all'inizio dell’era spaziale ha fornito un fondamentale contributo allo studio dell’alta atmosfera terrestre. Si vuole pertanto dare rilevanza ad un personaggio poco conosciuto in Italia, il quale ha raggiunto importanti traguardi a livello internazionale, divenendo anche Presidente della sezione atmosferica del COSPAR (il comitato internazionale per la ricerca spaziale) e della divisione atmosferica dell’Associazione Internazionale di Geomagnetismo e Aeronomia. Nato a Trieste, si trasferisce a Bologna per studiare all'università e trova lavoro all'Osservatorio Astronomico della città, dapprima come volontario e, dopo la laurea in Fisica, come assistente universitario. Si occupa principalmente di osservazioni meteorologiche e dello studio di stelle variabili. Costretto a lasciare l’Italia nel 1938 a causa delle leggi razziali (essendo ebreo), trova lavoro all'Università di Harvard, negli Stati Uniti, dove continua la sua attività con le stelle variabili. In seguito al lancio dello Sputnik I, riesce per primo a costruire un modello in grado di prevedere il moto orbitale dei satelliti artificiali. Ancora oggi i suoi modelli sono i più usati negli studi sull'alta atmosfera. Le informazioni iniziali sulla vita di Luigi, contenute soprattutto in necrologi e voci di generiche enciclopedie, erano alquanto limitate. Dopo numerose ricerche, specialmente su nuove fonti archivistiche e su fonti orali (preziosi colloqui con alcuni parenti) è stato possibile comporre un'immagine più completa della sua personalità, mettendo in evidenza il filo che lega i suoi primi studi a Bologna, la vicenda drammatica delle leggi razziali, la sua importante carriera di scienziato negli Stati Uniti, il paese al quale resterà legato fino alla scomparsa

A Hydrogenated amorphous silicon detector for Space Weather Applications

The characteristics of a hydrogenated amorphous silicon (a-Si:H) detector are presented here for monitoring in space solar flares and the evolution of large energetic proton events up to hundreds of MeV. The a-Si:H presents an excellent radiation hardness and finds application in harsh radiation environments for medical purposes, for particle beam characterization and in space weather science and applications. The critical flux detection threshold for solar X rays, soft gamma rays, electrons and protons is discussed in detail.Comment: 32 pages, 13 figures, submitted to Experimental Astronom

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

Outcomes from elective colorectal cancer surgery during the SARS-CoV-2 pandemic

This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic

An Improved Algorithm for On-Chip Clustering and Lossless Data Compression of HL-LHC Pixel Hits

A prototype chip, called RD53A, has been designed by the RD53 collaboration to face the very high hit and trigger rate requirements (up to 3 GHz/cm$^2$ and 1 MHz, respectively) of the High Luminosity LHC experiment upgrades. In this paper, an improved algorithm for data compression, capable of sustaining the very high data volume and proposed to be implemented in the periphery of the chip, is presented: it exploits Run Length Encoding (RLE) and Variable Length Coding (VLC) to compact chip pixel hit patterns. The compression and decompression algorithms are implemented with MATLAB, and the performance is calculated taking into account the RD53A data readout implementation and its chip simulation and verification framework (called VEPIX53). In all considered cases, the results show that the RLE and VLC combination achieves a data compression ratio between 1.57 and 1.62, resulting in a bitstream size reduction between 36.2% and 38.4% with respect to the rate of the current data transmission format

Nodi Urbani in: Architettura civile

Pubblicazione dei risultati del Workshop EXPO dopo expo, a cui hanno partecipato le scuole di dottorato di varie università italiane delle Facoltà di Architettura. La riflessione progettuale, sviluppata dalla lettura del tessuto edilizio e della maglia originaria fondiaria, di oriogine romana, per propone una ricucitura dell'apparente caos in un nuovo ordine urbano capace di porre al centro, di un tessuto duffuso proprio l'area marginale della fiera internazionale EXPO.In the scene of Milan hinterland, Expo area represents an opportunity for a strategy of territorial reorganization, that deals the issues of urban sprawl, excessive soil consumption and environmental discontinuity. From a common settlement strategy, that reinterprets the Cardo-Decumano system of Expo area, and a unique typological-constructive system, two proposals are presented: the first one is the idea of a concentrated citadel, that is built by addition around a central space; the second one is structured by the repetition of a “blade” that configures a passing linear system

Workshop “Expo dopo Expo

L’ipotesi di trasformazione dell’area Expo affronta il tema della grande dimensione e presuppone la considerazione di base che il problema della riutilizzazione delle aree nelle quali si è svolta la manifestazione non debba essere considerato di per sé, ma inserito in una più generale riflessione sul suo ruolo all’interno della periferia nord ovest di Milano

High-Performance Lead-Acid Batteries Enabled by Pb and PbO2 Nanostructured Electrodes: Effect of Operating Temperature

Lead-acid batteries are now widely used for energy storage, as result of an established and reliable technology. In the last decade, several studies have been carried out to improve the performance of this type of batteries, with the main objective to replace the conventional plates with innovative electrodes with improved stability, increased capacity and a larger active surface. Such studies ultimately aim to improve the kinetics of electrochemical conversion reactions at the electrode-solution interface and to guarantee a good electrical continuity during the repeated charge/discharge cycles. To achieve these objectives, our contribution focuses on the employment of nanostructured electrodes. In particular, we have obtained nanostructured electrodes in Pb and PbO2 through electrosynthesis in a template consisting of a nanoporous polycarbonate membrane. These electrodes are characterized by a wider active surface area, which allows for a better use of the active material, and for a consequent increased specific energy compared to traditional batteries. In this research, the performance of lead-acid batteries with nanostructured electrodes was studied at 10 C at temperatures of 25, −20 and 40 °C in order to evaluate the efficiency and the effect of temperature on electrode morphology. The batteries were assembled using both nanostructured electrodes and an AGM-type separator used in commercial batteries