Analisi e dimensionamento di un propulsore ad effetto Hall multicanale

Il presente lavoro riguarda l’analisi ed il dimensionamento di un propulsore ad effetto Hall a canali coassiali. Questo tipo di propulsori ancora non è stato realizzato, ma con l’aumentare delle potenze richieste a bordo dei satelliti questa soluzione potrebbe rivelarsi una buona alternativa ai cluster di propulsori a singolo canale, grazie ad una notevole riduzione degli ingombri e dei pesi. Il punto di partenza di questa tesi era una configurazione iniziale creata in modo tale da soddisfare i requisiti fondamentali riguardanti la forma del campo magnetico; procedendo iterativamente si sono in primo luogo analizzati i materiali a disposizione per la realizzazione del dispositivo, poi si è proceduto con un’analisi magnetica più precisa ed uno studio termico considerando quattro possibili configurazioni di funzionamento; si sono approfondite le suddette analisi considerando i reali contatti tra i componenti; quindi si sono effettuate alcune analisi multifisiche: termo-magnetica e termo-strutturale, per verificare il corretto funzionamento a temperatura di lavoro. Si è poi svolto uno studio gasdinamico per ottimizzare il flusso del gas dai condotti alle camere di accelerazione. Con le informazioni raccolte si è fissata la configurazione finale, intraprendendo la strada verso una fase sperimentale: all’analisi magnetica si è aggiunto uno studio sulle possibili attivazioni dei canali e sugli effetti di variazioni di corrente sulle singole bobine; all’analisi termica si sono accostati uno studio sul transitorio termico ed uno studio sulle temperature raggiunte a seguito di accensioni parziali del dispositivo. Infine, attraverso una attenta valutazione di tutti i risultati ottenuti, si sono tratte le opportune conclusioni. The present work regards analysis and sizing of a Hall Effect Thruster with coaxial channels. This class of thrusters has not been yet realized, but with powers increase on board of satellites, it could become a good alternative to clusters of single channel thrusters in minimizing weights and spaces. The starting point of this thesis is a preliminary configuration previously created to satisfy the shape of magnetic field basic requirements; advancing iteratively we have firstly analyzed available materials to build up this device, secondly we have proceeded with a more accurate magnetic analysis and a thermal analysis considering four possible working configurations; we have improved these results by considering real contacts between components’ surfaces; then we have done some multiphysic analysis, thermo-magnetic and thermo-structural, to verify the correct functioning at working temperatures. Then we have done a preliminary gasdinamic analysis to optimize gas flow from the ducts to the acceleration channels. With collected informations we fixed the final configuration, approaching the experimental phase: we added to the magnetic analysis a study about the possible activations of the channels and about the effects of any current variation; we added to the thermal analysis a study about the thermal transitory and a study about the temperatures reached in case of partial activation of this device. Finally considering all results found in this work, we arrived to the conclusions

Beta-Blocker Use in Older Hospitalized Patients Affected by Heart Failure and Chronic Obstructive Pulmonary Disease: An Italian Survey From the REPOSI Register

Beta (β)-blockers (BB) are useful in reducing morbidity and mortality in patients with heart failure (HF) and concomitant chronic obstructive pulmonary disease (COPD). Nevertheless, the use of BBs could induce bronchoconstriction due to β2-blockade. For this reason, both the ESC and GOLD guidelines strongly suggest the use of selective β1-BB in patients with HF and COPD. However, low adherence to guidelines was observed in multiple clinical settings. The aim of the study was to investigate the BBs use in older patients affected by HF and COPD, recorded in the REPOSI register. Of 942 patients affected by HF, 47.1% were treated with BBs. The use of BBs was significantly lower in patients with HF and COPD than in patients affected by HF alone, both at admission and at discharge (admission, 36.9% vs. 51.3%; discharge, 38.0% vs. 51.7%). In addition, no further BB users were found at discharge. The probability to being treated with a BB was significantly lower in patients with HF also affected by COPD (adj. OR, 95% CI: 0.50, 0.37-0.67), while the diagnosis of COPD was not associated with the choice of selective β1-BB (adj. OR, 95% CI: 1.33, 0.76-2.34). Despite clear recommendations by clinical guidelines, a significant underuse of BBs was also observed after hospital discharge. In COPD affected patients, physicians unreasonably reject BBs use, rather than choosing a β1-BB. The expected improvement of the BB prescriptions after hospitalization was not observed. A multidisciplinary approach among hospital physicians, general practitioners, and pharmacologists should be carried out for better drug management and adherence to guideline recommendations

The “Diabetes Comorbidome”: A Different Way for Health Professionals to Approach the Comorbidity Burden of Diabetes

(1) Background: The disease burden related to diabetes is increasing greatly, particularly in older subjects. A more comprehensive approach towards the assessment and management of diabetes’ comorbidities is necessary. The aim of this study was to implement our previous data identifying and representing the prevalence of the comorbidities, their association with mortality, and the strength of their relationship in hospitalized elderly patients with diabetes, developing, at the same time, a new graphic representation model of the comorbidome called “Diabetes Comorbidome”. (2) Methods: Data were collected from the RePoSi register. Comorbidities, socio-demographic data, severity and comorbidity indexes (Cumulative Illness rating Scale CIRS-SI and CIRS-CI), and functional status (Barthel Index), were recorded. Mortality rates were assessed in hospital and 3 and 12 months after discharge. (3) Results: Of the 4714 hospitalized elderly patients, 1378 had diabetes. The comorbidities distribution showed that arterial hypertension (57.1%), ischemic heart disease (31.4%), chronic renal failure (28.8%), atrial fibrillation (25.6%), and COPD (22.7%), were the more frequent in subjects with diabetes. The graphic comorbidome showed that the strongest predictors of death at in hospital and at the 3-month follow-up were dementia and cancer. At the 1-year follow-up, cancer was the first comorbidity independently associated with mortality. (4) Conclusions: The “Diabetes Comorbidome” represents the perfect instrument for determining the prevalence of comorbidities and the strength of their relationship with risk of death, as well as the need for an effective treatment for improving clinical outcomes

Antidiabetic Drug Prescription Pattern in Hospitalized Older Patients with Diabetes

Objective: To describe the prescription pattern of antidiabetic and cardiovascular drugs in a cohort of hospitalized older patients with diabetes. Methods: Patients with diabetes aged 65 years or older hospitalized in internal medicine and/or geriatric wards throughout Italy and enrolled in the REPOSI (REgistro POliterapuie SIMI—Società Italiana di Medicina Interna) registry from 2010 to 2019 and discharged alive were included. Results: Among 1703 patients with diabetes, 1433 (84.2%) were on treatment with at least one antidiabetic drug at hospital admission, mainly prescribed as monotherapy with insulin (28.3%) or metformin (19.2%). The proportion of treated patients decreased at discharge (N = 1309, 76.9%), with a significant reduction over time. Among those prescribed, the proportion of those with insulin alone increased over time (p = 0.0066), while the proportion of those prescribed sulfonylureas decreased (p < 0.0001). Among patients receiving antidiabetic therapy at discharge, 1063 (81.2%) were also prescribed cardiovascular drugs, mainly with an antihypertensive drug alone or in combination (N = 777, 73.1%). Conclusion: The management of older patients with diabetes in a hospital setting is often sub-optimal, as shown by the increasing trend in insulin at discharge, even if an overall improvement has been highlighted by the prevalent decrease in sulfonylureas prescription

Clinical features and outcomes of elderly hospitalised patients with chronic obstructive pulmonary disease, heart failure or both

Background and objective: Chronic obstructive pulmonary disease (COPD) and heart failure (HF) mutually increase the risk of being present in the same patient, especially if older. Whether or not this coexistence may be associated with a worse prognosis is debated. Therefore, employing data derived from the REPOSI register, we evaluated the clinical features and outcomes in a population of elderly patients admitted to internal medicine wards and having COPD, HF or COPD + HF. Methods: We measured socio-demographic and anthropometric characteristics, severity and prevalence of comorbidities, clinical and laboratory features during hospitalization, mood disorders, functional independence, drug prescriptions and discharge destination. The primary study outcome was the risk of death. Results: We considered 2,343 elderly hospitalized patients (median age 81 years), of whom 1,154 (49%) had COPD, 813 (35%) HF, and 376 (16%) COPD + HF. Patients with COPD + HF had different characteristics than those with COPD or HF, such as a higher prevalence of previous hospitalizations, comorbidities (especially chronic kidney disease), higher respiratory rate at admission and number of prescribed drugs. Patients with COPD + HF (hazard ratio HR 1.74, 95% confidence intervals CI 1.16-2.61) and patients with dementia (HR 1.75, 95% CI 1.06-2.90) had a higher risk of death at one year. The Kaplan-Meier curves showed a higher mortality risk in the group of patients with COPD + HF for all causes (p = 0.010), respiratory causes (p = 0.006), cardiovascular causes (p = 0.046) and respiratory plus cardiovascular causes (p = 0.009). Conclusion: In this real-life cohort of hospitalized elderly patients, the coexistence of COPD and HF significantly worsened prognosis at one year. This finding may help to better define the care needs of this population

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

Contribution à l’étude de «narso» : En Italie septentrionale – Sul nome di Narzole (Cuneo)

Serra Giandomenico. Contribution à l’étude de «narso» : En Italie septentrionale – Sul nome di Narzole (Cuneo). In: Revue Internationale d'Onomastique, 5e année N°1, mars 1953. pp. 10-12

Le date più antiche della penetrazione in Italia dei nomi degli eroi del ciclo brettone

Serra Giandomenico. Le date più antiche della penetrazione in Italia dei nomi degli eroi del ciclo brettone. In: Onomastica. Revue Internationale de Toponymie et d'Anthroponymie, 1e année N°3-4, Septembre-décembre 1947. Deuxième congrès international de toponymie et d'anthroponymie, Paris 15-19 juillet 1947. pp. 195-197

Alle origini del nome Modane

Serra Giandomenico. Alle origini del nome Modane. In: Revue Internationale d'Onomastique, 3e année N°2, juin 1951. pp. 83-90

A proposito delle voci francesi l’Habit e l’Habitarelle

Serra Giandomenico. A proposito delle voci francesi l’Habit e l’Habitarelle. In: Revue Internationale d'Onomastique, 8e année N°3, Septembre 1956. pp. 207-208