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Transanal Endoscopic Microsurgery: Endoscopy Assisted Treatment of Colorectal Anastomotic Stenosis
Giancarlo D’Ambrosio,Antonietta Lamazza,Rossella Palma,Andrea Picchetto,Cristina Panetta,Antonello Trecca,Stefano Pontone,Emanuele Lezoche 대한대장항문학회 2020 Annals of Coloproctolgy Vol.36 No.4
Transanal endoscopic microsurgery (TEM) is a type of natural orifice transluminal endoscopic surgery, developed for rectal tumors and used also to treat other rectal diseases. Anastomotic complications after colorectal surgery, including stenosis, represent a challenging problem. We present the case of a 36-year-old woman with a diagnosis of Hirschsprung disease that was submitted to a modified Duhamel operation. A postoperative barium enema showed a complete stricture of the anastomosis that was impossible to resolve by flexible endoscopic approach. Then an intraoperative endoscopic approach to facilitate the localization of preanastomotic colon (proximal colon from the anastomosis) was performed by a small colotomy and the colonic recanalization was obtained by the creation of a neo-anastomosis by TEM, under fluoroscopic-endoscopic control. The patient underwent a control barium enema showing regular retrograde transit of contrast medium without evidence of stenosis. In our experience, transanal approach by TEM-colonoscopy assisted is safe and feasible and represents a model of combined minimally invasive technique.
Stefano d’Ambrosio,Alessandro Ferrari,Alessandro Mancarella,Antonio Mittica 한국자동차공학회 2020 International journal of automotive technology Vol.21 No.1
An experimental investigation has been carried out to highlight the effects of different injection strategies on the performance and emissions of a low compression ratio Euro 5 diesel engine operated with high EGR rates. Rate-shaped main injections, achieved with piezoelectric and solenoid injectors by means of boot and injection fusion, respectively, as well as optimized multiple injection patterns have been compared. The results of the comparisons, performed with reference to a state-of-the-art double pilot-Main (pM) strategy, are presented in terms of engine-out exhaust emissions, combustion noise (CN) and fuel consumption. Rate-shaped main injections, when included in delayed multiple injection patterns, have shown a minor influence on reducing NOx, while a slight deterioration in soot has been found. Both a double pilot and a boot injection schedule have been able to reduce CN at low loads. A higher reduction in CN has been obtained with an injection fusion event. Finally, DoE optimized triple and quadruple injection strategies have led to improved soot-NOx trade-offs, with respect to the pM calibration. In fact, splitting the injection helps to entrain air inside the fuel plumes, thus creating locally leaner mixture (less prone to forming soot) and allowing increasing the EGR rates (reducing NOx formation).
A hybrid numerical flux for supersonic flows with application to rocket nozzles
Ferrero, Andrea,D'Ambrosio, Domenic Techno-Press 2020 Advances in aircraft and spacecraft science Vol.7 No.5
The numerical simulation of shock waves in supersonic flows is challenging because of several instabilities which can affect the solution. Among them, the carbuncle phenomenon can introduce nonphysical perturbations in captured shock waves. In the present work, a hybrid numerical flux is proposed for the evaluation of the convective fluxes that avoids carbuncle and keeps high-accuracy on shocks and boundary layers. In particular, the proposed flux is a combination between an upwind approximate Riemann problem solver and the Local Lax-Friedrichs scheme. A simple strategy to mix the two fluxes is proposed and tested in the framework of a discontinuous Galerkin discretisation. The approach is investigated on the subsonic flow in a channel, on the supersonic flow around a cylinder, on the supersonic flow on a flat plate and on the flow in a overexpanded rocket nozzle.
Observation of a first ν<sub>τ</sub> candidate event in the OPERA experiment in the CNGS beam
Agafonova, N.,Aleksandrov, A.,Altinok, O.,Ambrosio, M.,Anokhina, A.,Aoki, S.,Ariga, A.,Ariga, T.,Autiero, D.,Badertscher, A.,Bagulya, A.,Bendhabi, A.,Bertolin, A.,Besnier, M.,Bick, D.,Boyarkin, V.,Boz North-Holland Pub. Co 2010 Physics letters: B Vol.691 No.3
The OPERA neutrino detector in the underground Gran Sasso Laboratory (LNGS) has been designed to perform the first detection of neutrino oscillations in direct appearance mode through the study of the ν<SUB>μ</SUB>->ν<SUB>τ</SUB> channel. The hybrid apparatus consists of an emulsion/lead target complemented by electronic detectors and it is placed in the high energy long-baseline CERN to LNGS beam (CNGS) 730 km away from the neutrino source. Runs with CNGS neutrinos were successfully carried out in 2008 and 2009. After a brief description of the beam, the experimental setup and the procedures used for the analysis of the neutrino events, we describe the topology and kinematics of a first candidate ν<SUB>τ</SUB> charged-current event satisfying the kinematical selection criteria. The background calculations and their cross-check are explained in detail and the significance of the event is assessed.
An evaluation of the exposure in nadir observation of the JEM-EUSO mission
Adams, J.H.,Ahmad, S.,Albert, J.N.,Allard, D.,Ambrosio, M.,Anchordoqui, L.,Anzalone, A.,Arai, Y.,Aramo, C.,Asano, K.,Ave, M.,Barrillon, P.,Batsch, T.,Bayer, J.,Belenguer, T.,Bellotti, R.,Berlind, A.A. North-Holland ; Elsevier Science Ltd 2013 Astroparticle physics Vol.44 No.-
We evaluate the exposure during nadir observations with JEM-EUSO, the Extreme Universe Space Observatory, on-board the Japanese Experiment Module of the International Space Station. Designed as a mission to explore the extreme energy Universe from space, JEM-EUSO will monitor the Earth's nighttime atmosphere to record the ultraviolet light from tracks generated by extensive air showers initiated by ultra-high energy cosmic rays. In the present work, we discuss the particularities of space-based observation and we compute the annual exposure in nadir observation. The results are based on studies of the expected trigger aperture and observational duty cycle, as well as, on the investigations of the effects of clouds and different types of background light. We show that the annual exposure is about one order of magnitude higher than those of the presently operating ground-based observatories.
Final Results of the OPERA Experiment on ντ Appearance in the CNGS Neutrino Beam
Agafonova, N.,Alexandrov, A.,Anokhina, A.,Aoki, S.,Ariga, A.,Ariga, T.,Bertolin, A.,Bozza, C.,Brugnera, R.,Buonaura, A.,Buontempo, S.,Chernyavskiy, M.,Chukanov, A.,Consiglio, L.,D’Ambrosio, N.,De Lell American Physical Society 2018 Physical review letters Vol.120 No.21
<P>The OPERA experiment was designed to study nu mu -> nu tau oscillations in the appearance mode in the CERN to Gran Sasso Neutrino beam (CNGS). In this Letter, we report the final analysis of the full data sample collected between 2008 and 2012, corresponding to 17.97 x 10(19) protons on target. Selection criteria looser than in previous analyses have produced ten nu(tau) candidate events, thus reducing the statistical uncertainty in the measurement of the oscillation parameters and of nu(tau) properties. A multivariate approach for event identification has been applied to the candidate events and the discovery of nu(tau) appearance is confirmed with an improved significance level of 6.1 sigma. |Delta m(32)(2)| has been measured, in appearance mode, with an accuracy of 20%. The measurement of the nu(tau) charged-current cross section, for the first ti me with a negligible contamination from p(z), and the first direct evidence for the nu(tau) lepton number are also reported.</P>
Final results of the search for νμ → νe oscillations with the OPERA detector in the CNGS beam
Agafonova, N.,Aleksandrov, A.,Anokhina, A.,Aoki, S.,Ariga, A.,Ariga, T.,Bertolin, A.,Bozza, C.,Brugnera, R.,Buonaura, A.,Buontempo, S.,Chernyavskiy, M.,Chukanov, A.,Consiglio, L.,D’Ambrosio, N.,De Lel Institute of Physics Pub 2018 The journal of high energy physics Vol.2018 No.6