1,170 research outputs found
Development of a tilt-rotor model for real-time flight simulation
No full textThe aim of this work is to describe the development of a tilt-rotor model for real-time flight
simulation based on the NASA XV-15 prototype aircraft, for the integration with the ReDSim
Research and Didactic Flight Simulator of the ZAV Center of Aviation, at ZHAW Zurich
University of Applied Science in Winterthur, Switzerland. A simulation model is developed
in Matlab/Simulink® based on available literature and several off-line tests are carried out for
both the helicopter and the airplane modes of the aircraft. Furthermore, the simulation model
is integrated with the ReDSim and several pilot tests are performed. Results are presented,
weaknesses of the model are evaluated and further developments are suggested. Present work
is the result of a Final Thesis submitted as partial fulfillment of requirements for the author’s
Master’s of Science in Aerospace Engineering
Mathematical modelling of tilt-rotor aircraft configurations. A comprehensive model for flight control system development and real-time piloted simulation.
Get PDFL'abstract è presente nell'allegato / the abstract is in the attachmen
A Methodology for Preliminary Performance Estimation of a Hybrid-Electric Tilt-Wing Aircraft for Emergency Medical Services
Get PDFThis paper aims to provide a simple methodology
to preliminary size a hybrid-electric propulsion system for
large scale piloted, optionally piloted or unmanned tilt-wing
aircraft. In this work, the author refers to three mission
profile representative of an Emergency Medical Service (EMS)
operation and estimate the performance of the aircraft along
the mission. Thus, based on some assumptions on battery
technology, architecture of the hybrid system and mission safety
requirements, a methodology for preliminary performance estimation
is described and results for a baseline architecture are
presented. Based on present and near future battery technology
(in terms of charge/discharge rates and energy density), the
present study shows how safety requirements can strongly
affect the overall size of the power-plant system and impact
the feasibility of hybrid-electric technology in aeronautical
applications
First record of Nipponocythere Ishizaki, 1971 and Swainocythere Ishizaki, 1981 (Ostracoda) in the Late Quaternary in the Mediterranean Basin
Get PDFThe presence of Nipponocythere Ishizaki, 1971 and Swainocythere Ishizaki, 1981 is reported for the first time in Late Quaternary sediments of the Mediterranean Basin (Isle of Ischia, Campania, Southern Italy). Swainocythere, previously reported from Recent sediments of the Tunisian shelf, was previously unknown in the fossil record while Nipponocythere has never been previously cited from the Mediterranean Bain. The study of the benthic foraminifers and ostracods assemblages associated to the cited genera allowed to define a paleobathymetry of 70-100 m. The new subspecies Nipponocythere drapalensis Bonaduce, Abate & Barra pithekoussaii is described and illustrated
Dilution robustness for mean field ferromagnets
No full textIn this work we compare two different random dilutions on a mean field ferromagnet: the first model is built on a Bernoulli diluted graph while the second lives on a Poisson diluted one. While it is known that the two models have, in the thermodynamic limit, the same free energy, we investigate the structural constraints that the two models must fulfill. We rigorously derive for each model the set of identities for the multi-overlap distribution, using different methods for the two dilutions: constraints in the former model are obtained by studying the consequences of the self-averaging of the internal energy density, while in the latter they are obtained by a stochastic stability technique. Finally we prove that the identities emerging in the two models are the same, showing robustness of the ferromagnetic properties of diluted graphs with respect to the details of dilution
Crustacea Ostracoda
Get PDFThe class Ostracoda is made up of small crustaceans, with a shell size generally ranging from 0.2 to 30 mm, living in a wide variety of aquatic environment, from deep-sea waters to the proximity of hydrothermal springs. A small number of species has been recorded in damp terrestrial environments. The majority of the taxa have a wholly benthic lifestyle, but ostracods are also well represented in the pelagic fauna.
Recent species presently described are about 8.000, and the number of living species is probably around 20.000. Ostracods have a low-Mg bivalve carapace showing a high preservation potential both in subrecent and in ancient sediments. Consequently many species have been described exclusively on the basis of the shell features and the known fossil species, approximately 25.000, largely surpass the Recent ones (Horne et al., 2002).
In the Italian seas both the living subclasses - Myodocopa and Podocopa - occur. Subclass Myodocopa includes the orders Myodocopida and Halocyprida; the subclass Podocopa comprises orders Platycopida and Podocopida, while Paleocopida, frequently recorded in Paleozoic sediments and represented by few living species, seem to lack in Mediterranean waters.
A critical reviewing of available literature data allowed to recognize as living in Italian waters 377 ostracod species, pertaining to 102 genera. It has to be noted that distribution data are quite heterogeneous among different areas. The Adriatic (zones 7-9) ostracofaunas, studied in a series of wide investigations by authors (Ascoli, 1964; Masoli, 1968, 1969; Bonaduce et al., 1974, 1976; Breman, 1975, 1976a, 1976b; Montenegro and Pugliese, 1996) are the best known of the Mediterranean. Beginning from the G.W. Müller's monograph on the ostracods of the Gulf of Naples (1894), a cornerstone of the modern ostracodology, several papers (Puri, 1963; Puri et al., 1964; 1969; Bonaduce, 1965; Bonaduce and Gervasio, 1966; Melis and Pugliese, 1985; McKenzie and Bonaduce, 1993; Arbulla et al., 2001, 2004; Bonaduce and McKenzie, 2004) considered different areas of the Tyrrhenian Sea (zones 2-3) describing a number of new species and furnishing their distribution and ecological preferences. Even if data regarding the remaining part of the Italian Seas are less complete some areas, especially the Gulf of Taranto, have been studied in detail (Puri et al., 1969; Bonaduce and Pugliese, 1979; Bonaduce et al., 1982b, 1983, 1985; Peypouquet and Nachite, 1984; Bonaduce and Mascellaro, 1985; Malz and Jellinek, 1994; Aiello et al. 2006).
Studies concerning the taxonomy and ecology of a small number of taxa report the occurrence of many ostracod species in Italian waters, providing scattered but noteworthy data (Decima, 1964; Puri and Dickau, 1969; Sissingh, 1975; Athersuch, 1976, 1977, 1978a, 1978b, 1978c, 1978d, 1979a, 1979b, 1980a, 1980b, 1981, 1982; Minichelli et al., 1976; Pugliese et al., 1976; Bonaduce et al. 1976b, 1977, 1980; 1982a, 1998, 1999; Breman, 1978; Athersuch and Whittaker, 1982, 1987a, 1987b; Bonaduce and Danielopol, 1988; Danielopol and Bonaduce, 1990; Danielopol et al., 1995; Aiello and Barra, 2001a, Aiello et al., 2001; Mostafawi, 2002).
Furthermore, due to the high paleontological value of the ostracod shell, studies which afford primarily the study of fossil specimens, furnish distribution data on Recent species (Ruggieri, 1959, 1975, 1976; Bonaduce et al., 1986, Abate et al., 1993, 1994; Aiello et al., 1993, 1996a, 1996b, 1996c, 2000; Barra et al., 1996; Barra and Bonaduce, 1996, 2000; Aiello and Barra, 2001b; Aiello and Szczechura, 2001).
We have to underline that, although the relatively large amount of data, the knowledge of Italian ostracods is still incomplete. Detailed studies on Mediterranean areas such as the Aegean Sea (e.g. Barbeito-Gonzalez, 1971; Stambolidis, 1985) and North African waters (e.g. Yassini, 1979; Bonaduce et al. 1988; 1996; Lachenal, 1989) evidenced that many taxa are still undescribed or unrecorded in Italian waters. Considering the vicinity of these areas and (especially for the Greek waters) the similarity of ecological conditions, it can be expected that new investigations are needed to define exhaustively the distribution and taxonomy of the ostracods of the Italian seas
A methodology for multirotor aircraft power budget analysis
Get PDFThe primary purpose of this study is to analyse the performance of multirotor unmanned aircraft system platforms for passenger transport and compare them with an ordinary helicopter solution. This study aims to define a standard procedure for power budget analysis of unconventional vehicles recently proposed in the aerospace industry, providing guidelines on rotor sizing in terms of required power and the total number of rotors. The ultimate purpose of the proposed work is to describe a methodology for power estimation with regard to emerging electric vertical takeoff and landing (EVTOL) vehicles.
In the context of urban mobility, short-range passenger transport between critical hubs in cities is taken into account and innovative aircraft and traditional helicopters are compared according to a common mission profile. The power budget equations used in the helicopter literature are revisited to consider different multirotor configurations (up to 20 rotors) and evaluate the feasibility of innovative aerospace vehicle design.
The paper includes insights into the maximum number of rotors that ensure a significative, relative power reduction compared to helicopter platforms (the power-to-cruise over power-to-hover ratio appears to be improved). Based on this preliminary analysis, the results suggest the benefit of reducing the installed rotors to avoid excessive power loss in forward flight.
The proposed study provides guidelines for further design considerations and the future development of EVTOL multirotor aircraft.
This paper fulfils the identified need for a systematic approach on performance analysis for innovative vehicles involved in commercial applications
Glocal Detectives. Cultural Diversity In European Tv Crime Dramas
Get PDFTV screens across Europe are more and more filled with detectives, investigators, police(wo)men coming from abroad. After a long-lasting prominence of US figures, the last decades have offered an increasing visibility to characters coming from the UK, the Nordic regions of Scandinavia, the major continental markets as France, Germany, Spain and Italy, the Mediterranean regions, the Eastern and Central European countries, and so on. European crime narratives are complex objects: national, and global, and often glocal. Their popularity and circulation in European markets brings cultural diversity and puts audiences in touch with other not-so-far yet distinct cultures, while also – sometimes – laying ground for the development of a truly transnational, cross-European, shared popular culture. The special issue of Cinéma & Cie presents some results of the research carried out by Horizon 2020 project DETECt – Detecting Transcultural Identity in Contemporary Popular Crime Narratives, and includes a wide range of case histories, theoretical approaches, methodological frameworks
Notes on ferromagnetic diluted p-spin model
No full textIn this paper we develop the interpolating cavity field technique for the mean field ferromagnetic p-spin. The model we introduce is a natural extension of the diluted Curie-Weiss model to p > 2 spin interactions. Several properties of the free energy are analyzed and, in particular, we show that it recovers the expressions already known for p = 2 models and for p > 2 fully connected models. Further, as the model lacks criticality, we present extensive numerical simulations to evidence the presence of a first-order phase transition and deepen the behaviour at the transition line. Overall, a good agreement is obtained among analytical results, numerics and previous works. © 2011 Polish Scientific Publishers
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