Progettazione ed esecuzione di prova di collaudo su compressore centrifugo

Questo lavoro affronta il tema della progettazione e della realizzazione di un test meccanico ed un test termodinamico in condizioni di similitudine su un particolare compressore centrifugo, eseguito in accordo alle normative internazionali di settore (ASME PTC 10 e API 617). Lo scopo è quello di valutare le prestazioni del compressore in oggetto, quindi verificare la loro conformità alle suddette norme di riferimento e ai dati concordati in sede di contrattazione con il cliente. Inoltre è affrontata l’analisi di un fenomeno manifestatosi durante alcune prove termodinamiche di diversi compressori, che può avere un’influenza negativa sulla qualità dei risultati acquisiti; si tratta dell’oscillazione della portata del gas di processo in un punto stabile di lavoro. Tramite l’elaborazione di dati sperimentali acquisiti nel corso degli ultimi anni, si è individuata la causa di tale fenomeno nel dimensionamento della tubazione di aspirazione. A tal proposito è stata studiata un’ottimizzazione della progettazione del circuito di prova, ovviamente nel fedele rispetto delle normative di riferimento

Concomitant training in robotic and laparoscopic liver resections of low-to-intermediate difficulty score: a retrospective analysis of the learning curve

Abstract In the setting of minimally invasive liver surgery (MILS), training in robotic liver resections (RLR) usually follows previous experience in laparoscopic liver resections (LLR). The aim of our study was to assess the learning curve of RLR in case of concomitant training with LLR. We analyzed consecutive RLRs and LLRs by a surgeon trained simultaneously in both techniques (Surg1); while a second surgeon trained only in LLRs was used as control (Surg2). A regression model was used to adjust for confounders and a Cumulative Sum (CUSUM) analysis was carried out to assess the learning phases according to operative time and difficulty of the procedures (IWATE score). Two-hundred-forty-five procedures were identified (RobSurg1, n = 75, LapSurg1, n = 102, LapSurg2, n = 68). Mean IWATE was 4.0, 4.3 and 5.8 (p < 0.001) in each group. The CUSUM analysis of the adjusted operative times estimated the learning phase in 40 cases (RobSurg1), 40 cases (LapSurg1), 48 cases (LapSurg2); for IWATE score it was 38 cases (RobSurg1), 33 cases (LapSurg1), 38 cases (LapSurg2) respectively. Our preliminary experience showed a similar learning curve of 40 cases for low and intermediate difficulty RLR and LLR. Concomitant training in both techniques was safe and may be a practical option for starting a MILS program

Robotic versus laparoscopic liver resections: propensity-matched comparison of two-center experience

BackgroundThe advantages of the robotic approach in minimally invasive liver surgery (MILS) are still debated. This study compares the short-term outcomes between laparoscopic (LLR) and robotic (RLR) liver resections in propensity score matched cohorts.MethodsData regarding minimally invasive liver resections in two liver surgery units were retrospectively reviewed. A propensity score matched analysis (1:1 ratio) identified two groups of patients with similar characteristics. Intra- and post-operative outcomes were then compared. The difficulty of MILS was based on the IWATE criteria.ResultsTwo hundred sixty-nine patients underwent MILS between January 2014 and December 2021 (LLR = 192; RLR = 77). Propensity score matching identified 148 cases (LLR = 74; RLR = 74) consisting of compensated cirrhotic patients (100%) underwent non-anatomic resection of IWATE 1-2 class (90.5%) for a solitary tumor &lt; 5 cm in diameter (93.2%). In such patients, RLRs had shorter operative time (227 vs. 250 min, p = 0.002), shorter Pringle's cumulative time (12 vs. 28 min, p &lt; 0.0001), and less blood loss (137 vs. 209 cc, p = 0.006) vs. LLRs. Conversion rate was nihil (both groups). In RLRs compared to LLRs, R0 rate (93 vs. 96%, p &gt; 0.71) and major morbidity (4.1 vs. 5.4%, p &gt; 0.999) were similar, without post-operative mortality. Hospital stay was shorter in the robotic group (6.2 vs. 6.6, p = 0.0001).ConclusionThis study supports the non-inferiority of RLR over LLR. In compensated cirrhotic patients underwent resection of low-to-intermediate difficulty for a solitary nodule &lt; 5 cm, RLR was faster, with less blood loss despite the shorter hilar clamping, and required shorter hospitalization compared to LLR

Design of an Antimatter Large Acceptance Detector In Orbit (ALADInO)

International audienceA new generation magnetic spectrometer in space will open the opportunity to investigate the frontiers in direct high-energy cosmic ray measurements and to precisely measure the amount of the rare antimatter component in cosmic rays beyond the reach of current missions. We propose the concept for an Antimatter Large Acceptance Detector In Orbit (ALADInO), designed to take over the legacy of direct measurements of cosmic rays in space performed by PAMELA and AMS-02. ALADInO features technological solutions conceived to overcome the current limitations of magnetic spectrometers in space with a layout that provides an acceptance larger than 10 m2 sr. A superconducting magnet coupled to precision tracking and time-of-flight systems can provide the required matter–antimatter separation capabilities and rigidity measurement resolution with a Maximum Detectable Rigidity better than 20 TV. The inner 3D-imaging deep calorimeter, designed to maximize the isotropic acceptance of particles, allows for the measurement of cosmic rays up to PeV energies with accurate energy resolution to precisely measure features in the cosmic ray spectra. The operations of ALADInO in the Sun–Earth L2 Lagrangian point for at least 5 years would enable unique revolutionary observations with groundbreaking discovery potentials in the field of astroparticle physics by precision measurements of electrons, positrons, and antiprotons up to 10 TeV and of nuclear cosmic rays up to PeV energies, and by the possible unambiguous detection and measurement of low-energy antideuteron and antihelium components in cosmic rays

Design and performance of the prototype Schwarzschild-Couder telescope camera

International audienceThe prototype Schwarzschild-Couder Telescope (pSCT) is a candidate for a medium-sized telescope in the Cherenkov Telescope Array. The pSCT is based on a dual-mirror optics design that reduces the plate scale and allows for the use of silicon photomultipliers as photodetectors. The prototype pSCT camera currently has only the central sector instrumented with 25 camera modules (1600 pixels), providing a 2.68-deg field of view (FoV). The camera electronics are based on custom TARGET (TeV array readout with GSa/s sampling and event trigger) application-specific integrated circuits. Field programmable gate arrays sample incoming signals at a gigasample per second. A single backplane provides camera-wide triggers. An upgrade of the pSCT camera that will fully populate the focal plane is in progress. This will increase the number of pixels to 11,328, the number of backplanes to 9, and the FoV to 8.04 deg. Here, we give a detailed description of the pSCT camera, including the basic concept, mechanical design, detectors, electronics, current status, and first light