Search results for "ECC"
showing 10 items of 2939 documents
Automatic Landing System for Civil Unmanned Aerial System
2013
In spite of a number of potentially valuable civil UAS applications The International Regulations prohibit UAS from operating in the National Air Space. Maybe the primary reasons are safety concerns. In fact their ability to respond to emergent situations involving the loss of contact between the aircraft and the ground station poses a serious problem. Therefore, to an efficient safe insertion of UAS in the Civil Air Transport System one important element is their ability to perform automatic landing afterwards the failure. Moreover, the mathematical model of ground effect is usually neither included in the model of the aircraft during takeoff and landing nor in the design requirements of t…
Mathematical Model of Unmanned Aircraft In Ground Effect for Optimal Collision Avoidance
2011
The fundamental aim of the present paper is to model the aerodynamic characteristics of an Unmanned Aerial Vehicle(UAV) flying in ground effect. The second aim is to determine the relationship between the optimal avoidance maneuver and the control to execute it. In fact, this relationship is basilar to the development of a guidance scheme capable of approximating the optimal trajectory in real time. In the first part of this work ,a non-linear model is built in order to model the aerodynamic characteristics of an UAV flying In Ground Effect. To use a single model in the whole range of flying altitude, aerodynamic coefficients are modeled by means of hyperbolic equations. In particular, thes…
Prefazione a Messina, R., "La strage negata"
2016
"Il 19 ottobre del 1944 si consumò a Palermo uno degli eventi più drammatici dell'immediato dopoguerra: truppe dell'esercito italiano aprirono il fuoco su centinaia di cittadini che, al grido di 'pane, pasta e lavoro!', sfilavano per il centro della città in una pacifica protesta contro il carovita. 24 tra i manifestanti, e tra di loro bambini e ragazzi, rimasero uccisi; 156 furono feriti. [...] Ripercorrendo tutte le tappe dell'iter giudiziario dell'eccidio del 19 ottobre, e concentrandosi in particolare sull'analisi del processo svoltosi presso il tribunale militare di Taranto nel febbraio del 1947, Rino Messina ci dimostra come dietro il paravento della "tutela dell'ordine pubblico" si n…
Detección inmunohistoquímica de la proteína L1 de Virus Papiloma Humano (HPV) de alto riesgo en citologías y biopsias de cuello uterino
2005
Para confirmar la detección inmunohistoquímica de la proteína L1 de HPV de alto riesgo, tanto en citologías con anormalidades en células epiteliales como en biopsias con diagnóstico de carcinoma epidermoide cervical, se seleccionaron aleatoriamente: 11 citologías cervicales del año 2004 con interpretación citológica de anormalidades en células escamosas incluyendo: células escamosas atípicas y lesión intraepitelial escamosa de bajo y alto grado y 50 biopsias de cérvix con carcinoma epidermoide diagnosticados entre los años 1950 y 1980. Todas las muestras, tanto citológicas como histológicas fueron sometidas al procedimiento inmunohistoquímico para la detección de la proteína L1 de HPV de al…
The role of Bishop Conrad of Querfurt in the actions of Emperor Henry VI Hohenstaufen in Southern Italy. In the shadow of a great European policy (Ge…
2019
Conrad of Querfurt (ca. 1160–1202) was one of the most important and influential German bishops at the turn of the 12th and 13th centuries. He was associated with the Hohenstaufen dynasty. As a result, he became the bishop of Hildesheim (1194–1199), and then the bishop of Würzburg (1198–1202), as well as served two German kings from that family as chancellor (1194–1201). Conrad of Querfurt was a man of extremely broad political horizons and great ambitions. It was not a coincidence that the title of chancellor, along with the governorship of the Norman kingdom, was given to him by Henry VI. He took great care of his public image, which he proved by sponsoring the work of Peter of Eboli, tit…
Assessing the impact of COVID-19 on liver cancer management (CERO-19)
2021
[Background & Aims] The coronavirus disease 2019 (COVID-19) pandemic has posed unprecedented challenges to healthcare systems and it may have heavily impacted patients with liver cancer (LC). Herein, we evaluated whether the schedule of LC screening or procedures has been interrupted or delayed because of the COVID-19 pandemic.
Signature of the presence of a third body orbiting around XB 1916-053
2015
The ultra-compact dipping source \object{XB 1916-053} has an orbital period of close to 50 min and a companion star with a very low mass (less than 0.1 M$_{\odot}$). The orbital period derivative of the source was estimated to be $1.5(3) \times 10^{-11}$ s/s through analysing the delays associated with the dip arrival times obtained from observations spanning 25 years, from 1978 to 2002. The known orbital period derivative is extremely large and can be explained by invoking an extreme, non-conservative mass transfer rate that is not easily justifiable. We extended the analysed data from 1978 to 2014, by spanning 37 years, to verify whether a larger sample of data can be fitted with a quadra…
Reloading the Axion in a 3-3-1 setup
2020
We generalize the idea of the axion to an extended electroweak gauge symmetry setup. We propose a minimal axion extension of the Singer-Valle-Schechter (SVS) theory, in which the standard model fits in $\mathrm{SU(3)_L\otimes U(1)_X}$, the number of families results from anomaly cancellation, and the Peccei-Quinn (PQ) solution to the strong-CP problem is implemented. Neutrino masses arise from a type-I Dirac seesaw mechanism, suppressed by the ratio of SVS and PQ scales, suggesting the existence of new physics at a moderate SVS scale. Novel features include an enhanced axion coupling to photons when compared to the DFSZ axion, as well as flavour-changing axion couplings to quarks.
Mechanical properties of carbon nanotube fibres: St Venant’s principle at the limit and the role of imperfections
2015
Abstract Carbon nanotube (CNT) fibres, especially if perfect in terms of their purity and alignment, are extremely anisotropic. With their high axial strength but ready slippage between the CNTs, there is utmost difficulty in transferring uniformly any applied force. Finite element analysis is used to predict the stress distribution in CNT fibres loaded by grips attached to their surface, along with the resulting tensile stress–strain curves. This study demonstrates that, in accordance with St Venant’s principle, very considerable length-to-diameter ratios (∼103) are required before the stress becomes uniform across the fibre, even at low strains. It is proposed that lack of perfect orienta…
What is the meaning of ‘talent’ in the world of work?
2013
The ongoing confusion about the meaning of ‘talent’ within the world of work is hindering the establishment of widely accepted talent management theories and practices. The aim of this paper is to contribute to the literature on talent management by offering an indepth review of the talent concept within the specific context of the world of work, and proposing a framework for its conceptualization. We group different theoretical approaches to talent into ‘object’ (i.e., talent as natural ability; talent as mastery; talent as commitment; talent as fit) versus ‘subject’ approaches (i.e., talent as all people; talent as some people) and identify dynamics existing within and between them, as we…