Search results for " Mecca"
showing 10 items of 1035 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…
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…
State of the Art on Degree Study Programs in Agricultural/Biosystems Engineering in EU
2021
The process of international harmonisation of the degree study programs in Agricultural/Biosystems Engineering (ABE) was started by Prof. Giuseppe Pellizzi during CIGR 1989 Conference and was continued by Prof. Pierluigi Febo in EU, within EurAgEng SIG RD12 - Education and Communication, and also within CIGR WG1 - Agricultural Engineering University Curricula Harmonization. Then, four thematic networks were effective: 1) USAEE-TN (University Studies of Agricultural Engineering in Europe - A Thematic Network), comprising 31 HEIs (Higher Education Institutions) from 27 countries, from 2002 to 2006; 2) Consortium POMSEBES (Policy Oriented Measures in Support of the Evolving Biosystems Engineer…
Notes on Elia Ovazza, professor of TMM in Palermo since the end of 19-th century
2013
In this lecture the figure of Elia Ovazza, professor of TMM in Palermo since the end of 19-th century, is presented with a valuable legacy as referring to his activity in teaching, research, design and technology transfer with short biographical notes
Thermoelastic stress analysis of a 2D stress field using a single detector infrared scanner and lock-in filtering
2009
A low resolution, low cost, fast infrared scanner is used to acquire the temperature change along a line on the surface of cyclically loaded samples. The temperature signal is sampled versus time by exploiting the raster scanning movement of the thermocamera single detector. The temperature data is then post-processed by a Fast Fourier Transform based lock- in algorithm implemented in MATLAB ® , in order to filter out the thermoelastic effect induced temperature change. A procedure is also implemented in order to extend the data sampling time by opportunely synchronising successively grabbed data frames. The effectiveness of such synchronisation procedure is first demonstrated by performing…
A New Procedure for the Evaluation of Non-Uniform Residual Stresses by the Hole Drilling Method Based on the Newton-Raphson Technique
2010
The hole drilling method is one of the most used semi-destructive techniques for the analysis of residual stresses in mechanical components. The non-uniform stresses are evaluated by solving an integral equation in which the strains relieved by drilling a hole are introduced. In this paper a new calculation procedure, based on the Newton-Raphson method for the determination of zeroes of functions, is presented. This technique allows the user to introduce complex and effective forms of stress functions for the solution of the problem. All the relationships needed for the evaluation of the stresses are obtained in explicit form, eliminating the need to use additional mathematical tools. The t…
A Multistep Methodology for the Evaluation of Human Resources Using the Evidence Theory
2013
New relations between professional and work’s organizations introduced by computer applications, special vessel case study
2019
At present time the project of a naval vehicle, where with the word project we refer to all the process of design and manufacturing, especially when the vehicle offers special formal and performance characteristics, involves a number of operators that has been increasing considerably in recent decades, and this increased complexity can be correlated with dimensional and typological growth of many categories of ships. Simultaneously we are witnessing a complete new project approach, where the possibility given by the computer contribution to represent processes and results becomes crucial. The paper aims to investigate the consequences of this progress in the organization of the project and …
INTERVISTA AL PROF. TIZIANO CARUSO, DURANTE LA PRIMA GIORNATA DIMOSTRATIVA DEL PROGETTO INNOLIVO
2013
INTERVISTA AL PROF. TIZIANO CARUSO, DURANTE LA PRIMA GIORNATA DIMOSTRATIVA DEL PROGETTO INNOLIVO