Analisi del moto proprio di tre radio galassie: 3C 454.3, 3C 345, 3C 446

I nuclei galattici attivi sono delle galassie caratterizzate da una grande luminosità, rappre-sentano circa il 10% delle galassie osservabili. Il fenomeno che crea questa particolare ca-ratteristica si forma nel loro nucleo, zona centrale dalle dimensioni relativamente piccole rispetto all’intero ammasso di stelle. Inoltre, presentano emissione fortemente non termica su una larga banda dello spettro elettromagnetico. Alcune di queste regioni emettono getti di materia che possono essere molto lunghi, trasportando energia verso strutture estese (radiogalassie). La tesi tratta: la morfologia e classificazione degli AGN (Active Galactic Nuclei), le diver-se possibilità di osservare tali oggetti a seconda della banda che si vuole utilizzare ed un accenno al modello unificato. Si dedica un capitolo alla descrizione degli effetti relativistici che caratterizzano i nuclei attivi e dei meccanismi alla base dell’emissione non termica. La parte finale è dedicata al lavoro sperimentale, in cui si prendono dati pubblici di diversi AGN e li si analizza attraverso software specifici di analisi dati, con lo scopo di delineare un moto proprio di tali oggetti cosmici e studiare la variabilità del loro flusso. In questa parte, oltre a presentare i nuclei attivi in esame descrivendo le loro caratteristiche e proprie-tà, si definisce il processo di analisi dati e la loro elaborazione. Nella conclusione vengono discussi i risultati dell’elaborazione con eventuali commenti e riflessioni sugli stessi

Analisi del moto proprio di tre radio galassie: 3C 454.3, 3C 345, 3C 446

I nuclei galattici attivi sono delle galassie caratterizzate da una grande luminosità, rappre-sentano circa il 10% delle galassie osservabili. Il fenomeno che crea questa particolare ca-ratteristica si forma nel loro nucleo, zona centrale dalle dimensioni relativamente piccole rispetto all’intero ammasso di stelle. Inoltre, presentano emissione fortemente non termica su una larga banda dello spettro elettromagnetico. Alcune di queste regioni emettono getti di materia che possono essere molto lunghi, trasportando energia verso strutture estese (radiogalassie). La tesi tratta: la morfologia e classificazione degli AGN (Active Galactic Nuclei), le diver-se possibilità di osservare tali oggetti a seconda della banda che si vuole utilizzare ed un accenno al modello unificato. Si dedica un capitolo alla descrizione degli effetti relativistici che caratterizzano i nuclei attivi e dei meccanismi alla base dell’emissione non termica. La parte finale è dedicata al lavoro sperimentale, in cui si prendono dati pubblici di diversi AGN e li si analizza attraverso software specifici di analisi dati, con lo scopo di delineare un moto proprio di tali oggetti cosmici e studiare la variabilità del loro flusso. In questa parte, oltre a presentare i nuclei attivi in esame descrivendo le loro caratteristiche e proprie-tà, si definisce il processo di analisi dati e la loro elaborazione. Nella conclusione vengono discussi i risultati dell’elaborazione con eventuali commenti e riflessioni sugli stessi

Fabrication by magnetron sputtering and characterization of electrodes based on CuIn0.7Ga0.3Se2 (CIGS)

This thesis work aims to produce and test multilayer electrodes for their use as photocathode in a PEC device. The electrode developed is based on CIGS, a I-III-VI2 semiconductor material composed of copper (Cu), indium (In), Gallium (Ga) and selenium (Se). It has a bandgap in the range of 1.0-2.4 eV and an absorption coefficient of about 105cm−1, which makes it a promising photocathode for PEC water splitting. The idea of our multilayer electrode is to deposit a thin layer of CdS on top of CIGS to form a solid-state p–n junction and lead to more efficient charge separation. In addition another thin layer of AZO (Aluminum doped zinc oxide) is deposit on top of CdS since it would form a better alignment between the AZO/CdS/CIGS interfaces, which would help to drive the charge transport further and minimize charge recombination. Finally, a TiO2 layer on top of the electrodes is used as protective layer during the H2 evolution. FTO (Fluorine doped tin oxide) and Molybdenum are used as back-contact. We used the technique of RF magnetron sputtering to deposit the thin layers of material. The structural characterization performed by XDR measurement confirm a polycrystalline chalcopyrite structural with a preferential orientation along the (112) direction for the CIGS. From linear fit of the Tauc plot, we get an energy gap of about 1.16 eV. In addition, from a four points measurements, we get a resistivity of 0.26 Ωcm. We performed an electrochemical characterization in cell of our electrodes. The results show that our samples have a good stability but produce a photocurrent of the order of μA, three orders of magnitude smaller than our targets. The EIS analysis confirm a significant depletion of the species in front of the electrode causing a lower conversion of the species and less current flows

Using ZOOM-events for Scientific Conferences: The ICHEP 2022 Experience

The organization of seminars and conferences was strongly influenced by the covid-19 pandemic. In the early period of the pandemic, many events were canceled or held completely online, using video conferencing tools such as ZOOM or MS Teams or Google Meet. Later, thanks to large-scale vaccination and immunization, it was possible to organize again large events in person. Nevertheless it was still necessary to provide online modalities for participants who could not participate in person, having in fact hybrid events with both remote and in person participation. However, in 2022, the global pandemic situation was patchy, with many countries still affected by travel restrictions, making it necessary to provide online modalities for participants who could not participate in-person, having in fact hybrid events with both remote and in-person participation. In this contribution we describe the experience with the ZOOM-Events platform, used for the ICHEP 2022 International Conference on High Energy Physics, held in Bologna in July 2022, with about 1100 participants in-person and 300 connected remotely. We describe in detail how the ZOOM-Events platform was configured for the management of the numerous parallel sessions and the granting of access to participants and how we dealt with the problems that emerged in the organizational phases

Events with Isolated Charged Leptons and Large Missing Transverse Momentum at HERA

Striking events with isolated charged leptons, large missing transverse momentum and large transverse momentum of the hadronic final state were observed at the electron proton collider HERA in a data sample corresponding to a luminosity of about 130 pb-1. The H1 collaboration observed 11 events with isolated electrons or muons and with transverse momentum above 25 GeV. Only 3.4+-0.6 events were expected from Standard Model (SM) processes. Six of these events have a transverse momentum of greater than 40 GeV, while 1.3+-0.3 events were expected. The ZEUS collaboration observed good agreement with the SM. However, ZEUS found two events with a similar event topology, but tau leptons instead of electrons or muons in the final state. Only 0.2+-0.05 events were expected from SM processes. For various hypotheses the compatibility of the experimental results was investigated with respect to the SM and with respect to possible explanations beyond the SM. Prospects for the high-luminosity HERA-II data taking period are given

Simulating the development and progression of Chronic Kidney Disease and osteoporosis in people living with HIV

The "chronicization" of HIV infection brings about a growing necessity to attentively evaluate current and potential complications when prescribing the individual therapeutic regimen. Starting from this need, we developed two HIV-comorbidity simulators that, basing on the evidence available in medical literature and starting from the current clinical and demographic features of the individual patient, project and compare the risks of developing and worsening of nephropathy and osteopathy associated with possible ARV regimens. These simulators are embedded in a desktop, user-friendly software thought to be used by the treating physician during prescription discussion with his/her patients, in order to highlight expected clinical outcomes and healthcare resource consumption that may differ according to the therapeutic strategy selected. In this article we present the sources and methods used in developing the mathematical models, alongside a set of examples and the results of cohort-level validation runs

Search for squarks and gluinos with the ATLAS detector in final states with jets and missing transverse momentum using √s=8 TeV proton-proton collision data

A search for squarks and gluinos in final states containing high-p T jets, missing transverse momentum and no electrons or muons is presented. The data were recorded in 2012 by the ATLAS experiment in s√=8 TeV proton-proton collisions at the Large Hadron Collider, with a total integrated luminosity of 20.3 fb−1. Results are interpreted in a variety of simplified and specific supersymmetry-breaking models assuming that R-parity is conserved and that the lightest neutralino is the lightest supersymmetric particle. An exclusion limit at the 95% confidence level on the mass of the gluino is set at 1330 GeV for a simplified model incorporating only a gluino and the lightest neutralino. For a simplified model involving the strong production of first- and second-generation squarks, squark masses below 850 GeV (440 GeV) are excluded for a massless lightest neutralino, assuming mass degenerate (single light-flavour) squarks. In mSUGRA/CMSSM models with tan β = 30, A 0 = −2m 0 and μ > 0, squarks and gluinos of equal mass are excluded for masses below 1700 GeV. Additional limits are set for non-universal Higgs mass models with gaugino mediation and for simplified models involving the pair production of gluinos, each decaying to a top squark and a top quark, with the top squark decaying to a charm quark and a neutralino. These limits extend the region of supersymmetric parameter space excluded by previous searches with the ATLAS detector

Hunt for new phenomena using large jet multiplicities and missing transverse momentum with ATLAS in 4.7 fb−1 of s√=7TeV proton-proton collisions

Results are presented of a search for new particles decaying to large numbers of jets in association with missing transverse momentum, using 4.7 fb−1 of pp collision data at s√=7TeV collected by the ATLAS experiment at the Large Hadron Collider in 2011. The event selection requires missing transverse momentum, no isolated electrons or muons, and from ≥6 to ≥9 jets. No evidence is found for physics beyond the Standard Model. The results are interpreted in the context of a MSUGRA/CMSSM supersymmetric model, where, for large universal scalar mass m 0, gluino masses smaller than 840 GeV are excluded at the 95% confidence level, extending previously published limits. Within a simplified model containing only a gluino octet and a neutralino, gluino masses smaller than 870 GeV are similarly excluded for neutralino masses below 100 GeV

Measurement of the flavour composition of dijet events in pp collisions at root s=7 TeV with the ATLAS detector

This paper describes a measurement of the flavour composition of dijet events produced in pp collisions at √s=7 TeV using the ATLAS detector. The measurement uses the full 2010 data sample, corresponding to an integrated luminosity of 39 pb−1. Six possible combinations of light, charm and bottom jets are identified in the dijet events, where the jet flavour is defined by the presence of bottom, charm or solely light flavour hadrons in the jet. Kinematic variables, based on the properties of displaced decay vertices and optimised for jet flavour identification, are used in a multidimensional template fit to measure the fractions of these dijet flavour states as functions of the leading jet transverse momentum in the range 40 GeV to 500 GeV and jet rapidity |y|<2.1. The fit results agree with the predictions of leading- and next-to-leading-order calculations, with the exception of the dijet fraction composed of bottom and light flavour jets, which is underestimated by all models at large transverse jet momenta. The ability to identify jets containing two b-hadrons, originating from e.g. gluon splitting, is demonstrated. The difference between bottom jet production rates in leading and subleading jets is consistent with the next-to-leading-order predictions