Studio delle caratteristiche dei fotomoltiplicatori di grandi dimensioni per l'esperimento JUNO

L’esperimento JUNO (Jiangmen Underground Neutrino Observatory), attualmente in costruzione nella Cina meridionale, ha tra i propri obiettivi quello di determinare la gerarchia di massa dei neutrini. Il rivelatore è costituito da una sfera di scintillatore liquido di 36 metri di diametro ricoperta da 18000 fotomoltiplicatori ed immersa in una piscina instrumentata. Il modello di grandi dimensioni R12860 HQE della Hamamatsu Photonics è tra i fotomoltiplicatori candidati ad essere utilizzati nell’esperimento: lo scopo di questa tesi è studiare i segnali elettrici prodotti dal fotomoltiplicatore suddetto in condizioni di buio e in seguito a sollecitazione luminosa.ope

Broadband Dielectric Spectroscopy (BDS) investigation of molecular relaxations in durum wheat dough at low temperatures and their relationship with rheological properties

Broadband Dielectric Spectroscopy (BDS) was used to study the dielectric relaxation processes of semolina doughs. The dielectric properties were analyzed as a function of water content, and, additionally, the effects of NaCl presence and semolina characteristics were investigated. The dough was prepared using three different varieties of semolina. BDS measurements were conducted using a custom-made Rheo-dielectric tool composed of a Broadband Dielectric/Impedance Spectrometer connected to a strain-controlled rheometer. The temperature range investigated was from −135 °C to 25 °C, with a step of 5 °C, while the frequency range was 10$_{−1}$ – 10$_7$ Hz. Dielectric spectroscopy turned out to be a valuable technique for dough characterization. It is capable to distinguish the carbohydrates contribution and the different interactions between water and dough components. Moreover, this unique combination allows assessing correlations between rheological and dielectric properties, like the compliance of dough as a function of the relaxation processes and the influence of semolina components

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

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Studio delle caratteristiche dei fotomoltiplicatori di grandi dimensioni per l'esperimento JUNO

L’esperimento JUNO (Jiangmen Underground Neutrino Observatory), attualmente in costruzione nella Cina meridionale, ha tra i propri obiettivi quello di determinare la gerarchia di massa dei neutrini. Il rivelatore è costituito da una sfera di scintillatore liquido di 36 metri di diametro ricoperta da 18000 fotomoltiplicatori ed immersa in una piscina instrumentata. Il modello di grandi dimensioni R12860 HQE della Hamamatsu Photonics è tra i fotomoltiplicatori candidati ad essere utilizzati nell’esperimento: lo scopo di questa tesi è studiare i segnali elettrici prodotti dal fotomoltiplicatore suddetto in condizioni di buio e in seguito a sollecitazione luminosa

ENUBET: A monitored neutrino beam for high precision cross section measurements

International audienceThe main source of systematic uncertainty on neutrino cross section measurements at the GeV scale is represented by the poor knowledge of the initial flux. The goal of cutting down this uncertainty to 1% can be achieved through the monitoring of charged leptons produced in association with neutrinos, by properly instrumenting the decay region of a conventional narrow-band neutrino beam. Large angle muons and positrons from kaons are measured by a sampling calorimeter on the decay tunnel walls (tagger), while muon stations after the hadron dump can be used to monitor the neutrino component from pion decays. This instrumentation can provide a full control on both the muon and electron neutrino fluxes at all energies. Furthermore, the narrow momentum width (<10%) of the beam provides a O(10%) measurement of the neutrino energy on an event by event basis, thanks to its correlation with the radial position of the interaction at the neutrino detector. The ENUBET project has been funded by the ERC in 2016 to prove the feasibility of such a monitored neutrino beam and is cast in the framework of the CERN neutrino platform (NP06) and the Physics Beyond Colliders initiative. In our contribution, we summarize the ENUBET design, physics performance and opportunities for its implementation in a timescale comparable with next long baseline neutrino experiments

Lepton reconstruction in the ENUBET tagger

The ENUBET project aims at demonstrating the feasibility of a monitored neutrino beam in which the measurement of associated charged leptons in the instrumented decay region of a conventional beam is used to constrain the neutrino flux to unprecedented precision ($\mathcal{O}$(1\%)). Large angle muons and positrons from kaon decays are detected on the decay tunnel walls equipped with a sampling calorimeter with longitudinal, radial and azimuthal segmentation. After a brief description of the ENUBET beamline and of the detectors employed in the lepton tagger, the analysis chain for the event reconstruction, the background suppression and the identification of positrons and muons will be described

Detector R&D for the ENUBET instrumented decay region

The ENUBET/NP06 project aims at validating, both through simulation and detector prototyping, the possibility of a monitored neutrino beam through lepton tagging in an active decay tunnel. Such a technology would enable a control of the flux at the O(1%) level, offering the chance to measure neutrino cross-sections with unprecedented precision.The project has undergone various phases of R&D, whose milestones consisted in the construction of different calorimeters and the assessment of their performance. In this contribution the technical details and design solutions regarding the demonstrator, which is the final prototype currently under construction, and the lateral readout calorimeter, which is its precedessor, are discussed

Low energy radioactivity BG model in Super-Kamiokande detector from SK-IV data

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