3 resultados para Analysis of principal component

em AMS Tesi di Laurea - Alm@DL - Università di Bologna


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Damage tolerance analysis is a quite new methodology based on prescribed inspections. The load spectra used to derive results of these analysis strongly influence the final defined inspections programs that for this reason must be as much as possible representative of load acting on the considered structural component and at the same time, obtained reducing both cost and time. The principal purpose of our work is in improving the actual condition developing a complete numerical Damage Tolerance analysis, able to prescribe inspection programs on typical aircraft critical components, respecting DT regulations, starting from much more specific load spectrum then those actually used today. In particular, these more specific load spectrum to design against fatigue have been obtained through an appositively derived flight simulator developed in a Matlab/Simulink environment. This dynamic model has been designed so that it can be used to simulate typical missions performing manually (joystick inputs) or completely automatic (reference trajectory need to be provided) flights. Once these flights have been simulated, model’s outputs are used to generate load spectrum that are then processed to get information (peaks, valleys) to perform statistical and/or comparison consideration with other load spectrum. However, also much more useful information (loads amplitude) have been extracted from these generated load spectrum to perform the previously mentioned predictions (Rainflow counting method is applied for this purpose). The entire developed methodology works in a complete automatic way, so that, once some specified input parameters have been introduced and different typical flights have been simulated both, manually or automatically, it is able to relate the effects of these simulated flights with the reduction of residual strength of the considered component.

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Abstract (English) Cities nowadays face complex challenges to meet objectives regarding socio-economic development and quality of life. The concept of "smart city" is a response to these challenges. Although common practices are being developed all over the world, different priorities are defined and different architectures are followed. In this master thesis I focuses on the applied architecture of Riverside's case study, through a progression model that underline the main steps that moves the city from a situation of crisis, to be appointed "Intelligent Community" of the 2012 by Intelligent Community Forum. I discuss the problem of integration among the physical, institutional and digital dimension of smart cities and the "bridges" that connect these three spatialities. Riverside's progression model takes as a reference a comprehensive framework made unifying the keys component of the three most quoted framework in this field: a technology-oriented vision (strongly promoted by IBM [Dirks et al. 2009]), an approach-oriented one [Schaffers et al. 2011] that is sponsored by many initiatives within the European Commission, and a purely service-oriented one [Giffinger et al. 2007][Toppeta, 2010].

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Paramagnetic triple decker complexes of lanthanides are promising Single Molecule Magnets (SMMs), with many potential uses. Some of them show preferable relaxation behavior, which enables the recording of well resolved NMR spectra. These axially symmetric complexes are also strongly magnetically anisotropic, and this property can be described with the axial component of the magnetic susceptibility tensor, χa. For triple decker complexes with phthalocyanine based ligands, the Fermi˗contact contribution is small. Hence, together with the axial symmetry, the experimental chemical shifts in 1H and 13C NMR spectra can be modeled easily by considering pseudocontact and orbital shifts alone. This results in the determination of the χa value, which is also responsible for molecular alignment and consequently for the observation of residual dipolar couplings (RDCs). A detailed analysis of the experimental 1H-13C and 1H-1H couplings revealed that contributions from RDCs (positive and negative) and from dynamic frequency shifts (negative for all observed couplings) have to be considered. Whilst the pseudocontact shifts depend on the average positions of 1H and 13C nuclei relative to the lanthanide ions, the RDCs are related to the mobility of nuclei they correspond to. This phenomenon allows for the measurement of the internal mobility of the various groups in the SMMs.