Misuratore Digitale, Differenziale, Statistico per Spettrometro UV

Il lavoro di tesi, svolto presso la ditta Sistemi Digitali S.r.l. di Pisa, rientra nell'ambito del progetto SFAMEND, spettrometro per la misura delle ultratracce di metalli di transizione, concepito dalla stretta collaborazione con l'Istituto per i Processi Chimico-Fisici del CNR di Pisa. Inizialmente è stato svolto uno studio dello strumento per acquisire una profonda conoscenza delle varie sue parti, tramite la messa a punto e l'integrazione hardware-software di due dei circuiti elettronici del complesso sistema, ma anche per acquisire piena padronanza degli strumenti di laboratorio, quali l'oscilloscopio e il generatore di forme d'onda, e per apprendere le metodologie di progetto dell'azienda. La seconda fase del lavoro è consistita nella progettazione della scheda Acquisition Board, ultimo tassello mancante della sezione elettronica di SFAMEND. La scheda interfaccia un fotomoltiplicatore, ne condiziona il segnale con un circuito analogico a componenti discreti, effettua la conversione analogico-digitale a 16 bit - 5 Msps, ospita un dispositivo FPGA per la pre-eleborazione in tempo reale dei campioni e un microcontrollore che infine formatta e invia i dati su BUS seriali alla scheda di controllo dello strumento e gestisce guadagno e offset variabili della sezione analogica

On the propagation of a perturbation in an anharmonic system

We give a not trivial upper bound on the velocity of disturbances in an infinitely extended anharmonic system at thermal equilibrium. The proof is achieved by combining a control on the non equilibrium dynamics with an explicit use of the state invariance with respect to the time evolution.Comment: 14 page

Numerical studies to detect chaotic motion in the full planar averaged three-body problem

In this paper, the author deals with a well-known problem of Celestial Mechanics, namely the three-body problem. A numerical analysis has been done in order to prove existence of chaotic motions of the full-averaged problem in particular configurations. Full because all the three bodies have non-negligible masses and averaged because the Hamiltonian describing the system has been averaged with respect to a fast angle. A reduction of degrees of freedom and of the phase-space is performed in order to apply the notion of covering relations and symbolic dynamics

Chaotic coexistence of librational and rotational dynamics in the averaged planar three-body problem

Through an appropriate change of reference frame and rescalings of the variables and the parameters introduced, the Hamiltonian of the three-body problem is written as a perturbed Kepler problem. In this system, new Delaunay variables are defined and a suitable configuration of the phase space and the mass parameters is chosen. In such a system, wide regions of librational and rotational motions where orbits are regular and stable are found. Close to the separatrix of these regions, the existence of chaotic motions presenting a double rotational and librational dynamics is proved, numerically, through Poincare sections and the use of FLI

4D Phantom Project

4D Phantom project for the emulation of realistic internal organs movement in oncological patients during proton therapy irradiation. Project report of the "One dimention 4D Phantom prototype" accomplishment and validation, first step of the 4D Phantom realization. This report was published on June 2020 in the TIFPA-INFN 2019 Activity Report. This project was presented at the 106th Italian Physical Society Congress (SIF 2020) in the talk: "4DPhantom: An innovative device for oncological proton treatment uncertainties minimization" https://agenda.infn.it/event/23656/contributions/12064

On the spectral problem of the quantum KdV hierarchy

The spectral problem for the quantum dispersionless Korteweg-de Vries (KdV) hierarchy, aka the quantum Hopf hierarchy, is solved by Dubrovin. In this article, following Dubrovin, we study Buryak-Rossi's quantum KdV hierarchy. In particular, we prove a symmetry property and a non-degeneracy property for the quantum KdV Hamiltonians. On the basis of this we construct a complete set of common eigenvectors. The analysis underlying this spectral problem implies certain vanishing identities for combinations of characters of the symmetric group. We also comment on the geometry of the spectral curves of the quantum KdV hierarchy and we give a representation of the quantum dispersionless KdV Hamiltonians in terms of multiplication operators in the class algebra of the symmetric group.Comment: 21 page

Debate on work analysis for prevention / Débat sur l’analyse du travail pour la prévention / Dibattito sull’analisi del lavoro per la prevenzione

The Interdisciplinary Research Program “Organization and Well-Being” is aimed at identifying the relationships between the choices that structure the work processes, and the people’s health, defined in terms of physical, mental and social well-being. A method allowing to connect the analysis of organizational choices and the biomedical analysis of their consequences on the involved subjects has been the object of studies and discussions for three decades. This debate includes comments expressed from points of view concerning: ergonomics, work psychodynamics, work sociology, work psychology, ergology, linguistic activity. The way to conceive organization, action research, inter-disciplinarity and multi-disciplinarity, in the various approaches here represented, are the main object of discussion

Euler integral as a source of chaos in the three–body problem

In this paper we address, from a purely numerical point of view, the question, raised in Pinzari (2019), Pinzari (2020), and partly considered in Pinzari (2020), Di Ruzza et al. (2020), Chen and Pinzari (2021), whether a certain function, referred to as “Euler Integral”, is a quasi-integral along the trajectories of the three-body problem. Differently from our previous investigations, here we focus on the region of the “unperturbed separatrix”, which turns to be complicated by a collision singularity. Concretely, we reduce the Hamiltonian to two degrees of freedom and, after fixing some energy level, we discuss in detail the resulting three-dimensional phase space around an elliptic and an hyperbolic periodic orbit. After measuring the strength of variation of the Euler Integral (which are in fact small), we detect the existence of chaos closely to the unperturbed separatrix. The latter result is obtained through a careful use of the machinery of covering relations, developed in Gierzkiewicz and Zgliczyński (2019), Zgliczynski and Gidea (2004), Wilczak and Zgliczynski (2003)