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RISS 인기검색어
- 검색키워드
- 저자 : D'Ottavio, Michele (검색결과 3 건)
- 무료
- 기관 내 무료
- 유료
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On the development of the Anuloid, a disk-shaped VTOL aircraft for urban areas
Petrolo, Marco,Carrera, Erasmo,D'Ottavio, Michele,de Visser, Coen,Patek, Zdenek,Janda, Zdenek Techno-Press 2014 Advances in aircraft and spacecraft science Vol.1 No.3
This paper deals with the early development of the Anuloid, an innovative disk-shaped VTOL aircraft. The Anuloid concept is based on the following three main features: the use of a ducted fan powered by a turboshaft for the lift production to take-off and fly; the Coanda effect that is developed through the circular internal duct and the bottom portion of the aircraft to provide further lift and control capabilities; the adoption of a system of ducted fixed and swiveling radial and circumferential vanes for the anti-torque mechanism and the flight control. The early studies have been focused on the CFD analysis of the Coanda effect and of the control vanes; the flyability analysis of the aircraft in terms of static performances and static and dynamic stability; the preliminary structural design of the aircraft. The results show that the Coanda effect is stable in most of the flight phases, vertical flight has satisfactory flyability qualities, whereas horizontal flight shows dynamic instability, requiring the development of an automatic control system.
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Further results on the development of a novel VTOL aircraft, the Anuloid. Part II: Flight mechanics
Petrolo, Marco,Carrera, Erasmo,Visser, Coen de,D'Ottavio, Michele,Polit, Olivier Techno-Press 2017 Advances in aircraft and spacecraft science Vol.4 No.4
This paper presents the main outcomes of the preliminary development of the Anuloid, an innovative disk-shaped VTOL aircraft. The Anuloid has three main features: lift is provided by a ducted fan powered by a turboshaft; control capabilities and anti-torque are due to a system of fixed and movable surfaces that are placed in the circular internal duct and the bottom portion of the aircraft; the Coanda effect is exploited to enable the control capabilities of such surfaces. In this paper, results from flight mechanics are presented. The vertical flight dynamics were found to be desirable. In contrast, the horizontal flight dynamics of the aircraft shows both dynamic instability, and more importantly, insufficient pitch and roll control authority. Some recommendations and guidelines are then given aimed at the alleviation of such problems.
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Quality Over Volume: Modeling Centralization of Gastric Cancer Resections in Italy
Lorenzon Laura,Biondi Alberto,Agnes Annamaria,Scrima Ottavio,Persiani Roberto,D’Ugo Domenico 대한위암학회 2022 Journal of gastric cancer Vol.22 No.1
Background: The correlation between hospital volume and postoperative outcomes has led to the centralization of complex procedures in several countries. However, the results reported in relation to gastric cancer (GC) are contradictory. This study aimed to analyze GC surgical volumes and 30-day postoperative mortality in Italy and to provide a simulation for modeling centralization of GC resections based on district case volumes. Methods: A national registry was used to identify all GC resections, record mortality rates, and track the national in-border GC resection health travel. Hospitals were grouped according to caseload. Centralization of all GC procedures performed within the same district was modeled. The outcome measures were a minimal volume of 25 GC resections/ year and the 30-day postoperative mortality. Results: In 2018, 5,873 GC resections were performed in 498 Italian hospitals (mean resections per hospital per year: 11.8); the postoperative mortality rate (5.51%) was tracked from 2016–2018. GC resection health travel ranged from 2% to 50.5%, with a significant (P<0.001) difference between northern and central/southern Italy. The mean mortality rate was 7.7% in hospitals performing one to 3 GC resections per year, compared with 4.7% in those with >17 GC resections/year (P≤0.01). Most Italian districts achieved 25 procedures/year after centralization; however, 66.3% of GC cases in southern Italy vs. 42.2% in central and 52.7% in the northern regions (P<0.001) required reallocation. Conclusion: Postoperative mortality after GC resection correlated with hospital volume. Despite health travel, most Italian districts can reach a high-volume threshold, but discrepancies in mortality rates are alarming.Trial RegistrationResearch Registry Identifierresearchregistry6869
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