Search results for "Aircraft"
showing 10 items of 93 documents
Overview: On the transport and transformation of pollutants in the outflow of major population centres - Observational data from the EMeRGe European …
2022
Megacities and other major population centres (MPCs) worldwide are major sources of air pollution, both locally as well as downwind. The overall assessment and prediction of the impact of MPC pollution on tropospheric chemistry are challenging. The present work provides an overview of the highlights of a major new contribution to the understanding of this issue based on the data and analysis of the EMeRGe (Effect of Megacities on the transport and transformation of pollutants on the Regional to Global scales) international project. EMeRGe focuses on atmospheric chemistry, dynamics, and transport of local and regional pollution originating in MPCs. Airborne measurements, taking advantage of …
Aircraft noise and premature birth
1978
Abstract Certain physiological effects suggest that there may be a relationship between premature birth and noise exposure. Vasoconstriction in the peripheric blood vessel system is one effect. Others would be augmentation of the adrenocorticotrophic hormone and a higher vegetative excitability during pregnancy. Animal experiments have demonstrated negative effects but there is little literature available as yet on the specific relationship between exposure to aircraft noise and negative effects on pregnancies. A study of this relationship was undertaken in an area near the airport at Dusseldorf, Germany. While no significant negative effects could be demonstrated, a tendency toward an incr…
MR imaging of the lungs with hyperpolarized helium-3 gas transported by air.
2002
Hyperpolarized noble gas MRI shows promise in the functional imaging of the pulmonary air spaces. The production of hyperpolarized (HP) gas requires specialized laser optical pumping apparatus, which is not likely to be home built in the majority of clinical MRI radiology centres. There are two routes through which HP gas will be made available to hospitals for clinical use: either the apparatus will be installed locally at a considerable expense to the centre, or a central facility will produce the gas and then deliver it to remote MRI sites as and when required. In this study, the feasibility of transporting large quantities of HP gas for in vivo MR imaging from a remote production facili…
Exploratory analysis of safety data and their interrelation with flight trajectories and network metrics
2013
This paper presents an exploratory analysis of the correlation between different network metrics and safety events. The objective is to develop analysis methods and indicators that relate the network structure with safety events. In particular by using data gathered with an automatic tool developed by EUROCONTROL and a database of traffic data, we measured the correlations between the classical metrics of the airspace network, especially the network of navigation points, and the occurrence of Short Term Conflicts Alerts (STCA). The results obtained are not univocal; correlation between STCA occurrences and classical network metrics are present but the correlation coefficient is around 0.7. …
How do airlines preferences about engines influence the competition in the commercial aircraft industry: an empirical analysis
2011
This paper examines the competitive context in the commercial aircraft industry. In particular, the aim of the research here presented is to understand what are the main drivers influencing the choice of a specific engine manufacturer in an aircraft, and how such preferences influence the competition between Airbus and Boeing. In order to do that, we have collected data about the fleet composition of the top 25 airlines and we have located the main drivers influencing the engine configuration in: route specialization, business model and maintenance policy. Implications of such empirical findings in the competition among aircraft manufacturers are finally discussed.
Forensic investigation in aircraft accident with the aid of CT (MSCT), and Magnetic Resonance Imaging (MRI): our experience
2011
The autors report their experience in a case of air disaster in which a Tuninter airlines ATR 72 fallen down into the sea near Capo Gallo coast (Palermo, Italy) with 39 persons on board, resulting in six-teen victims. In the present contribute the authors argued the causes of the death and analysed patternes of injuries sustained by passengers involved in the fatal airplane accident using the conventional autopsy combined with postmortem Multi Slice Computed Tomography (MSCT) examination.
Neck and Shoulder Muscle Activation Among Experienced and Inexperienced Pilots in +Gz Exposure
2017
Background The aim of the present study was to compare differences in electromyography (EMG) activation of the neck and shoulder muscles between groups of inexperienced and experienced pilots during controlled +Gz exposure in a centrifuge. Methods The subjects were volunteer cadets (inexperienced group) and lieutenants (experienced group) undergoing their first centrifuge training. The first group did not have any high performance aircraft (HPA) experience, while the latter one had a 1-yr experience of intense flying of HPA. During the centrifuge run, EMG activity was recorded from the left and right shoulder, neck flexor, and neck extensor muscles. Results The pilots without HPA experience…
State Estimation of a Nonlinear Unmanned Aerial Vehicle Model using an Extended Kalman Filter
2008
An Extended Kalman Filter is designed in order to estimate both state variables and wind velocity vector at the same time for a non conventional unmanned aircraft. The proposed observer uses few measurements, obtained by means of either conventional simple air data sensors or a low cost GPS. To cope with the low rate of the GPS with respect to the other sensors, the EKF algorithm has been modified to allow for a dual rate measurement model. State propagation is obtained by means of an accurate six degrees of freedom nonlinear model of the aircraft dynamics. To obtain joint estimation of state and disturbance, wind velocity components are included in the set of the state variables. Both stoc…
Modelling strategic alliances in the wide-body long range aircraft market
2007
Abstract The wide-body long-range aircrafts market is characterized by increasing rivalry between Airbus and Boeing. One of the factors that drive their strategic behaviour is technological. We propose a technology indicator to identify conditions under which the aircraft companies have incentives to join a coalition. For this, we provide measurement of the side-payments necessary to sign a strategic alliance aimed at reducing technological barriers in the market. The results suggest that the existence of side-payments guarantees the stability of a strategic alliance if the gap in the technological level between the firms is high, or competition is through prices. For monopoly, a strategic …
A Hybrid Energy Storage Sizing for a Vertical Take-off and Landing Electric Aircraft
2021
The energy storage sizing procedure for an all-electric aircraft, characterised by vertical take-off and landing (VTOL), is presented in the paper. In order to define the energy consumption, the propulsion system model has been developed and simulated, referring to a specific configuration of VOLT obtained by the transformation of a very light twin-propeller aircraft named Tecnam P2012 T. Specifically, a flight mission-oriented to air city taxing has been considered. The simulation results highlight the presence of significant peak power during take-off and landing. At the aim of optimising the weight and the volume of the energy storage systems (ESSs), considered a critical issue in all-el…