388 research outputs found
In primum librum Regum expositionum libri VI
No full textThe paper traces the misunderstandings of the commentary on the first book of Regum attributed to Gregory the Great. The history of the editions is analyzed till the discovery of the only manuscript known of the work, Cava dei Tirreni, Biblioteca dell'Abbazia 9. The criteria of the last edition by Patrick Verbraken are discussed as he uncritically favored the manuscript on the constitutio textus. The problem of the authorship of the work is investigated: although recent studies date the commentary to the twelfth century and ascribe it to Peter of Venosa on the basis of the Chronicon Venusinum, it is possible that the author used texts authentically gregorian
Obsidio Jadrensis. Cronica Jadretina
No full textNel 1345 la città dalmata di Zara si ribellò al dominio veneziano estromettendone il presidio di guardia, ma si dovette arrendere nuovamente a Venezia dopo un assedio durato 16 mesi. Gli eventi sono conosciuti fin nei particolari perché oggetto di due diverse cronache, la Obsidio Jadrensis, composta da un anonimo, evidentemente fautore dell’aristocrazia zaratina e a essa appartenente, nonché testimone oculare dei fatti; la Cronica Jadretina, composta da un anonimo di parte avversa, un veneziano, deciso assertore dei valori morali e civili della Dominante. Il contributo esamina i due testi, esaminandone la tradizione (per entrambe limitata a pochissimi manoscritti) e il diverso carattere ideologico e stilistico
Fault Diagnosis for Aircraft System Models: An Introduction from Fault Detection to Fault Tolerance
No full textSafety in aircraft systems is a concern of rising importance, especially due to the sophisticated control devices exploited to improve the overall system performance, including both digital designs and complex hardware (input-output sensors, actuators, and components). Thus, control systems must include automatic supervision tasks to diagnose incipient malfunctions, as early as possible. This book focuses on the design of robust linear and nonlinear dynamic filters, obtained via model-based and analytical approaches for fault diagnosis and identification. The problem is treated in all its aspects covering: nonlinear modelling of aircraft systems; design of disturbance decoupled dynamic filters for residual generation; fault detection and estimation, fault tolerant control. Sample case studies are used to demonstrate the application of these techniques to high fidelity flight simulators. This book will be of interest to researchers in aircraft fault tolerant control, fault detection and diagnosis. Aircraft control engineers interested in applying the latest methods in fault detection and diagnosis will benefit from the simulation examples
Edoardo Grassia, Sabato Martelli Castaldi. Il generale partigiano
No full textQuando l’8 settembre del 1985 in una solenne cerimonia in Campidoglio venne conferita postuma al generale Sabato Martelli Castaldi la Medaglia d’oro al valore militare, pochi sapevano i retroscena e le vicissitudini di questo personaggio. Fu solo nell’anno 1996 quando lo storico e giornalista Mario Avagliano pubblicò un testo che, a distanza di più di cinquant’anni dalla sua morte, prese in considerazione quell’«esempio nobilissimo di completa e disinteressata dedizione alla causa della liber..
Vita Tibulli
No full textI codici fondamentali del corpus di elegie di Albio Tibullo recano in apertura un’anonima Vita del poeta che funge da accessus alla raccolta intera. Secondo alcuni si tratterebbe di un testo di origine medievale, privo di valore documentario; secondo altri, all’opposto, di una reliquia preziosa del De poetis di Svetonio. Il contributo esamina il carattere di tale biografia, ne considera le modalità di trasmissione, rileva i modi con i quali essa è stata progressivamente interpolata e accresciuta, senza tuttavia che ne venisse completamente oscurato o smarrito l’originario carattere
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Impact of Eisenia fetida earthworms and biochar on potentially toxic element mobility and health of a contaminated soil
No full textThis study aimed to evaluate the influence of Eisenia fetida (Savigny), added to an acidic soil contaminated with potentially toxic elements (PTEs; As, Sb, Cd, Pb, Zn) and amended with a softwood-derived biochar (2 and 5% w/w), on the mobility of PTEs and soil health (i.e. nutrient availability, enzyme activity and soil basal respiration). The PTEs bioaccumulation by E. fetida and the acute ecotoxicity effects of the amended soils were also evaluated. The interaction between earthworms and biochar led to a significant increase in soil pH, organic matter, dissolved organic carbon content, cation exchange capacity, and exchangeable Ca compared to the untreated soil. Moreover, the water-soluble and readily exchangeable PTE fraction decreased (with the exception of Sb) between 1.2- and 3.0-fold in the presence of biochar and earthworms. Earthworms, biochar, and their combination, led to a reduction of phosphomonoesterase activity which in soils amended with biochar and earthworms decreased between 2.2- and 2.5-fold with respect to the untreated soil. On the other hand, biochar and earthworms also enhanced soil basal respiration and protease activity. Although the survival rate and the weight loss of E. fetida did not change significantly with the addition of 2% biochar, adding the highest biochar percentage (5%) resulted in a survival rate that was ~2-fold lower and a weight loss that was 2.5-fold higher than the other treatments. The PTE bioaccumulation factors for E. fetida, which were less than 1 for all elements (except Cd), followed the order Cd>As>Zn>Cu>Pb>Sb and were further decreased by biochar addition. Overall, these results highlight that E. fetida and biochar, especially at 2% rate, could be used for the restoration of soil functionality in PTE-polluted environments, reducing at the same time the environmental risks posed by PTEs, at least in the short time
Design of residual generators and adaptive filters for the FDI of aircraft model sensors
No full textThe main contribution of this paper is the description and application of a comprehensive set of
methodologies for fault detection and isolation (FDI) of aircraft sensors. In particular, a new nonlinear
geometric approach (NLGA) and an efficient linear polynomial method (PM) are presented and
compared, together with simulation results obtained from a commercial aircraft model. Adaptive filters
with disturbance decoupling for fault identification are designed via the developed NLGA-based
method. On the other hand, the FDI scheme based on linear PM exploits a disturbance decoupling
technique in connection with a linear dynamic filter design procedure. The FDI strategies are applied to
the aircraft simulator data in a flight condition characterised by tight–coupled longitudinal and lateral
dynamics. Moreover, in order to analyse robustness and reliability properties of the two FDI schemes,
extensive simulations are performed in the presence of turbulence, measurement noise and modelling
errors
PARSIMONIOUS MODEL FOR AIR-DATA READOUT FROM “ON-SKIN” PRESSURE MEASUREMENTS IN SUBSONIC FLOWS
No full textA model is introduced to compactly express the tie between pressure gradients on aircraft wings and the in-flow attitude angles and stream speed. The model is opti-mized for application in an instrumentation system inferring air-speed and angle of attack from a multi-point, redundant set of differential pressure measurements directly taken on the aircraft skin by strip-type sensors. It borrows from the analytical solutions for airfoils in subsonic flows, introducing a sufficient (yet parsimonious) parameterization enabling calibration on experimental data with good fitting for a wide range of airfoil types and sensor positionin
Le dediche di Giovanni Immonide
No full textThe flight from Rome of Formoso, bishop of Porto, on Easter night 876 and his subsequent conviction in the Roman synods are echoed in the dedication of the last two John the Deacon’s works, Vita Gregorii I papae and the rhythmic rewriting of the Cena Cypriani. The contribution reconstructs John Immonide’s figure, his role and his friendships within the cubiculum Lateranense, and analyzes the critical loci of the manuscript tradition of the dedication poem to Pope John VIII, prefacing the hagiographical text, and of the so called Epilogus and Suppositio closing the Cena. The sections analyzed show a tradition variously attested and not univocal, that is evidence of reworking and leads to suspect that the author has reviewed the dedications of his works when he was expelled from the Lateran, falled into disgrace with the pope, and he never reached a final version of them
Fault Diagnosis Strategies for a Simulated Nonlinear Aircraft Model
No full textIn this work, different procedures for sensor Fault Detection and Isolation (FDI)
applied to a simulated model of a commercial aircraft are presented. The main point of the
paper regards the design of two FDI schemes based on a linear Polynomial Method (PM) and
the NonLinear Geometric Approach (NLGA). The obtained results highlight a good trade–off
between solution complexity and achieved performances. The FDI schemes are applied to the
aircraft model, characterised by tight–coupled longitudinal and lateral dynamics. The properties
of the residual generators are experimentally investigated and verified by simulating a general
aircraft reference trajectory. The overall performance of the developed FDI schemes are analysed
in the presence of turbulence, measurement and model errors. Comparisons with other FDI
methods based on Neural Networks (NN) and Unknown Input Kalman Filter (UIKF) are finally
reported
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