Measurement of the muon-induced neutron flux at LNGS with the LVD experiment

In this thesis we describe in detail the Monte Carlo simulation (LVDG4) built to interpret the experimental data collected by LVD and to measure the muon-induced neutron yield in iron and liquid scintillator. A full Monte Carlo simulation, based on the Geant4 (v 9.3) toolkit, has been developed and validation tests have been performed. We used the LVDG4 to determine the active vetoing and the shielding power of LVD. The idea was to evaluate the feasibility to host a dark matter detector in the most internal part, called Core Facility (LVD-CF). The first conclusion is that LVD is a good moderator, but the iron supporting structure produce a great number of neutrons near the core. The second conclusions is that if LVD is used as an active veto for muons, the neutron flux in the LVD-CF is reduced by a factor 50, of the same order of magnitude of the neutron flux in the deepest laboratory of the world, Sudbury. Finally, the muon-induced neutron yield has been measured. In liquid scintillator we found $(3.2 \pm 0.2) \times 10^{-4}$ n/g/cm$^2$, in agreement with previous measurements performed at different depths and with the general trend predicted by theoretical calculations and Monte Carlo simulations. Moreover we present the first measurement, in our knowledge, of the neutron yield in iron: $(1.9 \pm 0.1) \times 10^{-3}$ n/g/cm$^2$. That measurement provides an important check for the MC of neutron production in heavy materials that are often used as shield in low background experiments.

Studies of the atmospheric muon flux with the ANTARES detector

The thesis main topic is the determination of the vertical component of the atmospheric muon flux as a function of the sea depth at the ANTARES site. ANTARES is a Cherenkov neutrino telescope placed at 2500m depth in the Mediterranean Sea at 40 km from the southern cost of France. In order to retrieve back the physical flux from the experimental data a deconvolution algorithm has been perform which takes into consideration the trigger inefficiensies and the reconstruction errors on the zenith angle. The obtained results are in good agreement with other ANTARES indipendent analysis.

Trasporto di materia in membrane polimeriche e nanocomposite per la separazione di gas

Membrane-based separation processes are acquiring, in the last years, an increasing importance because of their intrinsic energetic and environmental sustainability: some types of polymeric materials, showing adequate perm-selectivity features, appear rather suitable for these applications, because of their relatively low cost and easy processability. In this work have been studied two different types of polymeric membranes, in view of possible applications to the gas separation processes, i.e. Mixed Matrix Membranes (MMMs) and high free volume glassy polymers. Since the early 90’s, it has been understood that the performances of polymeric materials in the field of gas separations show an upper bound in terms of permeability and selectivity: in particular, an increase of permeability is often accompanied by a decrease of selectivity and vice-versa, while several inorganic materials, like zeolites or silica derivates, can overcome this limitation. As a consequence, it has been developed the idea of dispersing inorganic particles in polymeric matrices, in order to obtain membranes with improved perm-selectivity features. In particular, dispersing fumed silica nanoparticles in high free volume glassy polymers improves in all the cases gases and vapours permeability, while the selectivity may either increase or decrease, depending upon material and gas mixture: that effect is due to the capacity of nanoparticles to disrupt the local chain packing, increasing the dimensions of excess free volume elements trapped in the polymer matrix. In this work different kinds of MMMs were fabricated using amorphous Teflon® AF or PTMSP and fumed silica: in all the cases, a considerable increase of solubility, diffusivity and permeability of gases and vapours (n-alkanes, CO2, methanol) was observed, while the selectivity shows a non-monotonous trend with filler fraction. Moreover, the classical models for composites are not able to capture the increase of transport properties due to the silica addition, so it has been necessary to develop and validate an appropriate thermodynamic model that allows to predict correctly the mass transport features of MMMs. In this work, another material, called poly-trimethylsilyl-norbornene (PTMSN) was examined: it is a new generation high free volume glassy polymer that, like PTMSP, shows unusual high permeability and selectivity levels to the more condensable vapours. These two polymer differ each other because PTMSN shows a more pronounced chemical stability, due to its structure double-bond free. For this polymer, a set of Lattice Fluid parameters was estimated, making possible a comparison between experimental and theoretical solubility isotherms for hydrocarbons and alcoholic vapours: the successfully modelling task, based on application of NELF model, offers a reliable alternative to direct sorption measurement, which is extremely time-consuming due to the relevant relaxation phenomena showed by each sorption step. For this material also dilation experiments were performed, in order to quantify its dimensional stability in presence of large size, swelling vapours.

Profili critici in materia di transnational group action

La presente tesi di dottorato ha ad oggetto l’analisi dei profili critici emersi nella prassi in relazione alle transnational damages group actions. All’interno di tale esteso ambito di ricerca, senza pretese di esaustività, si affronteranno determinati aspetti, tenendo in considerazione quanto accaduto negli ordinamenti che, sebbene in modo assai limitato, hanno già conosciuto tali problematiche. A seguito di una prima parte meramente introduttiva, nel secondo capitolo, si inquadreranno brevemente gli strumenti di tutela collettiva risarcitoria, indicando in che cosa consistano, a quali esigenze rispondano e quale origine abbiano; si indicheranno altresì i criteri distintivi e di classificazione che maggiormente possono rilevare nell’ottica di una cross border litigation. Nel terzo capitolo si analizzerà in termini essenziali la disciplina delle azioni collettive di alcuni Paesi, al fine di porre le basi necessarie per comprendere in quale contesto normativo si pongano le problematiche inerenti alle multi-jurisdictional collective redress actions. Nel quarto capitolo, si prenderà in considerazione la dimensione transnazionale delle azioni collettive, tenendo presenti le categorie e le regole affermatesi nel diritto internazionale privato e processuale e, soprattutto, quelle esistenti nell’ordinamento italiano e comunitario. Si individueranno poi gli obiettivi prioritari che si deve porre il giudice richiesto di giudicare sull’azione collettiva nella necessità di rendere una pronuncia o approvare una transazione che, da un lato, sia riconosciuta ed eseguita nei Paesi in cui dovrà essere riconosciuta ed eseguita e che, dall’altro lato, in ipotesi di opt out procedure, precluda ai soggetti che la pronuncia o la transazione dovrebbe vincolare successive azioni individuali e/o collettive in altri Paesi. Nel quinto capitolo, alla luce dei dati indicati nel terzo capitolo e delle considerazioni effettuate nel quarto capitolo, si analizzeranno alcuni dei profili critici posti dalla dimensione transnazionale delle azioni collettive; a tal fine, la trattazione verrà suddivisa in diversi punti che, pur essendo necessariamente connessi tra loro, nella loro individualità riescano ad evidenziare l’importanza e la centralità di determinate questioni. Peraltro, nell’intento di rispondere in modo adeguato alle problematiche analizzate, si indicheranno alcune delle soluzioni sperimentate dalla pratica giudiziaria o proposte dalla recente letteratura sul tema. Seguirà, infine, un ultimo capitolo contenente le osservazioni conclusive sugli esiti del lavoro.

Measurement of the atmospheric muon charge ratio with the OPERA detector

The atmospheric muon charge ratio, defined as the number of positive over negative charged muons, is an interesting quantity for the study of high energy hadronic interactions in atmosphere and the nature of the primary cosmic rays. The measurement of the charge ratio in the TeV muon energy range allows to study the hadronic interactions in kinematic regions not yet explored at accelerators. The OPERA experiment is a hybrid electronic detector/emulsion apparatus, located in the underground Gran Sasso Laboratory, at an average depth of 3800 meters water equivalent (m.w.e.). OPERA is the first large magnetized detector that can measure the muon charge ratio at the LNGS depth, with a wide acceptance for cosmic ray muons coming from above. In this thesis, the muon charge ratio is measured using the spectrometers of the OPERA detector in the highest energy region. The charge ratio was computed separately for single and for multiple muon events, in order to select different primary cosmic ray samples in energy and composition. The measurement as a function of the surface muon energy is used to infer parameters characterizing the particle production in atmosphere, that will be used to constrain Monte Carlo predictions. Finally, the experimental results are interpreted in terms of cosmic ray and particle physics models.

Electron identification and reconstruction with the OPERA ECC bricks and search for muon neutrino to electron neutrino oscillations

The procedure for event location in OPERA ECC has been optimazed for penetrating particles while is less efficient for electrons. For this reason new procedure has been defined in order to recover event with an electromagnetic shower in its final state not located with the standard one. The new procedure include the standard procedure during which several electromagnetic shower hint has been defined by means of the available data. In case the event is not located, the presence of an electromagnetic shower hint trigger a dedicated procedure. The old and new location procedure has been then simulated in order to obtain the standard location efficiency and the possible gain due to the new one for the events with electromagnetic shower. Finally a Data-MC comparison has been performed for the 2008 and 2009 runs for what concern the NC in order to validate the Monte Carlo. Then the expected electron neutrino interactions for the 2008 and 2009 runs has been evaluated and compared with the available data.

I limiti all'autonomia procedurale degli Stati membri dell'UE in materia risarcitoria

This work analyses the limits that the principle of State liability for damages suffered by individuals because of breach of EU law poses to the procedural autonomy of the Member States of the EU. The introductory part of this work is dedicated to the general character of the limitations EU law poses to the State’s competence in procedural matters. The first part of the research, instead, focuses on the specific limits that european law poses on the rules of procedure related to the legal regime of the right to compensation and its operating conditions; in particular, this first part explores respectively the “substantive” and “procedural” limits that EU law poses to the State’s autonomy to regulate actions for damages for breaches of EU law. The substantial limits concern the conditions of eligibility of liability and the constitutive conditions of the right to compensation; the procedural limits to the action for damages refer to the concrete organization and characteristics of the judicial action. The second part of the research is devoted to rules of procedure governing the relations between judicial remedies explicitly aimed at protecting the right to reparation and other remedies that may be relevant, both europeans and nationals. The first chapter of the second part of this work focuses on the rules governing the relations between the action for damages brought up at the national level and the remedies provided by european Treaties; finally, I explore the relations between the action for damages brought up at the national level and other remedies present in the same national juridical order. I reconstruct all the limits to the procedural autonomy of Member States concerning the right to compensation; consequently, I verify that those limits represent part of the system of internal procedures, able to guarantee the respect of european law.

Concessioni di servizio in ambito interportuale, portuale e demaniale marittimo ed esercizio delle relative attività: l'impatto della disciplina comunitaria in materia di libera prestazioni di servizi.

Come si evince dal titolo della tesi, la ricerca effettuata dal presente candidato nel corso del dottorato di ricerca ha avuto ad oggetto l’analisi delle competenze che, a diverso livello, comunitario, nazionale e regionale, sono attribuite agli enti in materia di rilascio di concessioni di servizi in abito interportuale, portuale e demaniale marittimo. L’attenzione, pertanto, ha dovuto innanzitutto essere rivolta ai compiti ed alle facoltà che, in forza del trattato che istituisce la Comunità Europea, sono attribuite alla Comunità stessa. Si è provveduto, pertanto, ad analizzare l’evoluzione della normativa per giungere all’attuale sistema giuridico. Gli aspetti della disciplina delle concessioni, oggetto di ricerca, hanno dovuto ripercorrere i vari procedimenti di infrazione comminati dalla Corte Europea, per i quali il sistema giuridico nazionale si è dovuto adattare con non poche difficoltà, soprattutto per la presenza di posizioni e prassi, negli anni, divenute consolidate.