28 research outputs found
ExoMars 2016 Schiaparelli Module Trajectory and Atmospheric Profiles Reconstruction: Analysis of the On-board Inertial and Radar Measurements
On 19th October 2016 Schiaparelli module of the ExoMars 2016 mission flew through the Mars atmosphere. After successful entry and descent under parachute, the module failed the last part of the descent and crashed on the Mars surface. Nevertheless the data transmitted in real time by Schiaparelli during the entry and descent, together with the entry state vector as initial condition, have been used to reconstruct both the trajectory and the profiles of atmospheric density, pressure and temperature along the traversed path.
The available data-set is only a small sub-set of the whole data acquired by Schiaparelli, with a limited data rate (8 kbps) and a large gap during the entry because of the plasma blackout on the communications.
This paper presents the work done by the AMELIA (Atmospheric Mars Entry and Landing Investigations and Analysis) team in the exploitation of the available inertial and radar data. First a reference trajectory is derived by direct integration of the inertial measurements and a strategy to overcome the entry data gap is proposed. First-order covariance analysis is used to estimate the uncertainties on all the derived parameters. Then a refined trajectory is computed incorporating the measurements provided by the on-board radar altimeter.
The derived trajectory is consistent with the events reported in the telemetry and also with the impact point identified on the high-resolution images of the landing site.
Finally, atmospheric profiles are computed tacking into account the aerodynamic properties of the module. Derived profiles result in good agreement with both atmospheric models and available remote sensing observations
Restructuring surgical training after COVID-19 pandemic: A nationwide survey on the Italian scenario on behalf of the Italian polyspecialistic young surgeons society (SPIGC)
Introduction: The COVID-19 pandemic has led to the disruption of surgical training. Lack of communication, guidelines for managing clinical activity as well as concerns for safety in the workplace appeared to be relevant issues. This study aims to investigate how surgical training has been reorganized in Italy, almost 2 years after the outbreak of COVID-19 pandemic. Materials and methods: A 16-item-electronic anonymous questionnaire was designed through SurveyMonkey© web application. This survey was composed of different sections concerning demographic characteristics and impacts of the second COVID-19 pandemic wave on surgical and research/didactic activities. Changes applied in the training programme and activities carried out were also investigated. The survey was carried out in the period between June and October 2021. Results: Four hundred and thirty responses were collected, and 399 were considered eligible to be included in the study analysis. Three hundred and thirty-five respondents continued working in Surgical Units, with a significant reduction (less than one surgical session per week) of surgical sessions in 49.6% of them. With concern to didactic and research activities, 140 residents maintained their usual activity, while 116 reported a reduction. A sub-group analysis on resident moved to COVID-19 departments showed a reduction of research activities in 35% of them. During the period considered in this survey, the surgical training program was not substantially modified for most of participants (74.6%). Conclusion: Our survey demonstrated that surgical residency programs haven't improved 2 years after the beginning of the pandemic. Further improvements are needed to guarantee completeness of surgical training, even in emergency conditions
Double-stapling technique for transhiatal distal esophageal resection: Feasibility test in a cadaver model.
OBJECTIVES:
To assess the feasibility of a new surgical technique for the resection of the distal third of the esophagus and/or cardias for neoplasm.
METHODS:
This surgical technique consists of two steps: For this purpose we built a stainless steel support bar for the anvil that is thinner than the freespace of a standard linear suturing stapler (TATM). The support bar holds up a push rod that can be adapted to the hooking-unhooking of the anvil.
RESULTS:
We performed our new technique on five cadavers. We did not encounter any difficulty during the procedures. We tested the anastomosis with hydropneumatic assessment without recording any leaks. The esophago-enteric anastomosis was then opened without finding any mechanical defects related to the procedure.
CONCLUSION:
It can often be very difficult to fashion a safe hand-sewn pouch or a purse string around the anvil of an EEATM during the resection of the distal third of the esophagus or the cardias by a trans-hiatal approach. Moreover, there is no standardized procedure to minimize anastomotic leak. To avoid these mechanical problems we designed this innovative procedure, which is considered to be reproducible without significant training