93 research outputs found

    Innovative Aircraft Aeroelastic Modelling and Control

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    The aeroelastic design of innovative aircraft wing configurations imposes the designer to deal with specific phenomena, which are not usually considered in classical aircraft definition. The design process itself, though, gives the designer several indications on how to maintain the safety standards imposed by regulations. The investigation of the basic aeroelastic principles for unconventional wings with high aspect ratios can be extremely interesting as, once introduced in a multidisciplinary design, they can be very effective in giving an early determination of the static and dynamic behaviour of the aircraft, leading to significant improvements in the configuration weight, cost, and overall performance. The paper shows some preliminary results as part of the main objectives of the In.A.Team group (Innovative Aircraft Theoretical-Experimental Aeroelastic Modelling) at Politecnico di Torino, Italy. The In.A.Team Project has the following main objectives: 1) to develop multidisciplinary analysis methods appropriate to unconventional aircrafts (highly flexible, "morphing" vehicles); 2) to develop the capability of illustrating and understanding the effects of uncertainties on the behaviour of an aeroelastic system; 3) to apply the innovative adaptive L1 control techniques to highly flexible wings, 4) to integrate theoretical analysis with commercial structural (FEM) and aerodynamic tools (CFD). 5) to design and manufacture an aeroelastic experimental-test-model. 6) to validate theoretical/numerical results by vibration and aeroelastic wind tunnel tests

    Practical considerations for the design of an aeroelastic energy harvester

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    Achieving the optimal balance between weight and energy consumption during flight mission remains a challenge for the design of very efficient high altitude long endurance aircrafts (HALE). These aircraft are intended to have flight missions that can range from 30 to 90 days. Composite materials are used to provide the structural integrity of the aircraft while minimizing its weight. Typically composites are used in long and slender structural elements of the HALE and are the main drivers of dynamic aeroelastic instabilities, even at low speed. This is due to the higher structural flexibility they introduce. Therefore, in order to respond to the demand of HALE aircrafts of having a wider amount of energy on board, without any substantial weight penalization, an experimental piezoelectric wing have been designed with the aim of exploiting aeroelastic instabilities or any other type of induced vibrations to generate electric energy directly on board. The numerical model of the piezoelectric wing, presented in this paper, is built starting from the assumptions of the 3D Euler-Bernoulli beam theory and of the strip theory for the aerodynamic loads. A preliminary sensitivity study was carried out, over the flutter solutions, for the identification of a suitable experimental prototype, to be used for modal and wind tunnel tests. The test campaign showed a good agreement between numerical and experiments results, highlighting, above all, the encouraging results in terms of energy harvesting and in terms of the exploitation potential of the piezoelectric design in the dynamic of structures

    ENFICA-FC: Design of transport aircraft powered by fuel cell & flight test of zero emission 2-seater aircraft powered by fuel cells fueled by hydrogen

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    Fuel cells could become the main power source for small general aviation aircraft or could replace APU and internal sub-systems on larger aircraft, to obtain all-electric or more-electric air vehicles. There are several potential advantages of using such a power source, that range from environmental and economic issues to performance and operability aspects. A preliminary design is reported. Also, the paper contains a description of testing activities related to experimental flights of an all-electric general aviation aircraft fueled by hydrogen. Great importance has been given to the testing phase of the prototype and examples of each testing stage are shown ranging from the single components to the final test flights. During the 6 experimental flights a rotation speed of 84 km/h was obtained in 184 m of taxi at power of 35 kW. Level flight was attained at 135 km/h and endurance of 39 min by mean of only a fuel cell power setting (speed world record for the FAI Sporting Code Category C - airplane

    Usefulness of Peptide C during the oral glucose tolerance test to evaluate insulin resistance in pediatric patients

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    La Diabetes Mellitus tipo 2 es un trastorno metabólico, poligénico y multifactorial en el que se dan dos hechos fundamentales: la insulinoresistencia (IR) y la disfunción de la célula ß pancreática. Comofactor pre-coz en la historia natural de la diabetes, hasta 10 años antes de observarse laprimera hiperglucemia en ayunas, se han descripto fallas del pico precoz de insulina pos-tprandiala los 30 minutos de administrada la sobrecar-ga. El péptido C se libera en cantidades equimolecula-res con la insulina, por lo que la medición del mismo es una representación fidedigna de la función de la célula ß pancreática. Los inmunoensayos para la determinación de insulina presentan alta variabilidad, tanto que se ha considerado controvertida su utilidad. El péptido C tiene menor variabilidad metodológica, haciendo más repro-ducible y simple la interpretación de los resultados. Objetivos: evaluar la reproducibilidad de las determi-naciones de insulina y péptido C en dos plataformas comerciales, y establecer la utilidad de la medición de péptido C durante la prueba de tolerancia oral a la glu-cosa (PTOG) como una herramienta sencilla y confiable para la valoración de insulinorresistencia en pacientes pediátricos

    Laparoscopic right hemicolectomy: a SICE (Società Italiana di Chirurgia Endoscopica e Nuove tecnologie) network prospective study on the approach to right colon lymphadenectomy in Italy: is there a standard?—CoDIG 2 (ColonDx Italian Group)

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    Background: Colon cancer is a disease with a worldwide spread. Surgery is the best option for the treatment of advanced colon cancer, but some aspects are still debated, such as the extent of lymphadenectomy. In Japanese guidelines, the gold standard was D3 dissection to remove the central lymph nodes (203, 213, and 223), but in 2009, Hoenberger et al. introduced the concept of complete mesocolic excision, in which surgical dissection follows the embryological planes to remove the mesentery entirely to prevent leakage of cancer cells and collect more lymph nodes. Our study describes how lymphadenectomy is currently performed in major Italian centers with an unclear indication on the type of lymphadenectomy that should be performed during right hemicolectomy (RH). Methods: CoDIG 2 is an observational multicenter national study that involves 76 Italian general surgery wards highly specialized in colorectal surgery. Each center was asked not to modify their usual surgical and clinical practices. The aim of the study was to assess the preference of Italian surgeons on the type of lymphadenectomy to perform during RH and the rise of any new trends or modifications in habits compared to the findings of the CoDIG 1 study conducted 4 years ago. Results: A total of 788 patients were enrolled. The most commonly used surgical technique was laparoscopic (82.1%) with intracorporeal (73.4%), side-to-side (98.7%), or isoperistaltic (96.0%) anastomosis. The lymph nodes at the origin of the vessels were harvested in an inferior number of cases (203, 213, and 223: 42.4%, 31.1%, and 20.3%, respectively). A comparison between CoDIG 1 and CoDIG 2 showed a stable trend in surgical techniques and complications, with an increase in the robotic approach (7.7% vs. 12.3%). Conclusions: This analysis shows how lymphadenectomy is performed in Italy to achieve oncological outcomes in RH, although the technique to achieve a higher lymph node count has not yet been standardized. Trial registration (ClinicalTrials.gov) ID: NCT05943951
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