Making digitalization effective: an exploration of the complementarity between digital technologies and organizational practices in the Italian Automotive Component Industry

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Metastable SUSY Breaking and Supergravity at Finite Temperature

We study how coupling to supergravity affects the phase structure of a system exhibiting dynamical supersymmetry breaking in a metastable vacuum. More precisely, we consider the Seiberg dual of SQCD coupled to supergravity at finite temperature. We show that the gravitational interactions decrease the critical temperature for the second order phase transition in the quark direction, that is also present in the global case. Furthermore, we find that, due to supergravity, a new second order phase transition occurs in the meson direction, whenever there is a nonvanishing constant term in the superpotential. Notably, this phase transition is a necessary condition for the fields to roll, as the system cools down, towards the metastable susy breaking vacuum, because of the supergravity-induced shift of the metastable minimum away from zero meson vevs. Finally, we comment on the phase structure of the KKLT model with uplifting sector given by the Seiberg dual of SQCD.Comment: 38 pages; Section 6 amended and expanded, references adde

Half-BPS Geometries and Thermodynamics of Free Fermions

Solutions of type IIB supergravity which preserve half of the supersymmetries have a dual description in terms of free fermions, as elucidated by the "bubbling AdS" construction of Lin, Lunin and Maldacena. In this paper we study the half-BPS geometry associated with a gas of free fermions in thermodynamic equilibrium obeying the Fermi-Dirac distribution. We consider both regimes of low and high temperature. In the former case, we present a detailed computation of the ADM mass of the supergravity solution and find agreement with the thermal energy of the fermions. The solution has a naked null singularity and, by general arguments, is expected to develop a finite area horizon once stringy corrections are included. By introducing a stretched horizon, we propose a way to match the entropy of the fermions with the entropy of the geometry in the low temperature regime. In the opposite limit of high temperature, the solution resembles a dilute gas of D3 branes. Also in this case the ADM mass of the geometry agrees with the thermal energy of the fermions.Comment: 37 pages, 2 figures, latex; v2: minor corrections, references adde

More supersymmetric Wilson loops

We present a large new family of Wilson loop operators in N=4 supersymmetric Yang-Mills theory. For an arbitrary curve on the three dimensional sphere one can add certain scalar couplings to the Wilson loop so it preserves at least two supercharges. Some previously known loops, notably the 1/2 BPS circle, belong to this class, but we point out many more special cases which were not known before and could provide further tests of the AdS/CFT correspondence.Comment: 9 pages, LaTe

Polymer Crystallization Waves

We prove the existence of travelling wave solutions for a polymer crystallization model. The mathematical problem governing the process consists in a system of two coupled first order PDE, the heat equation with a source term for the temperature and the isokinetic law, involving an order parameter $\psi \in$ [0, 1], whose extreme values correspond to pure phases

On the W&Y interpretation of high-energy Drell-Yan measurements

High-energy neutral and charged Drell--Yan differential cross-section measurements are powerful probes of quark-lepton contact interactions that produce growing-with-energy effects. This paper provides theoretical predictions of the new physics effects at the Next-to-Leading order in QCD and including one-loop EW corrections at the single-logarithm accuracy. The predictions are obtained from SM Monte Carlo simulations through analytic reweighting. This eliminates the need of performing a scan on the new physics parameter space, enabling the global exploration of all the relevant interactions. Furthermore, our strategy produces consistently showered events to be employed for a direct comparison of the new physics predictions with the data, or to validate the unfolding procedure than underlies the cross-section measurements. Two particularly relevant interactions, associated with the W and Y parameters of EW precision tests, are selected for illustration. Projections are presented for the sensitivity of the LHC and of the HL-LHC measurements. The impact on the sensitivity of several sources of uncertainties is quantified.Comment: 32 page, 10 figures, 3 tables; v2: several plots have been updated to fix a problem in the code, the overall discussion has been slightly improved, and few typos have been corrected; v3: typos corrected, preprint adde

Lezioni di Sistemi Dinamici

This work is based on the “Notes for the course of dynamic systems” written by Professor Riccardo Ricci in 2005 and subsequently reworked until the year of his death, which occurred in 2013. Starting from the latest version, the scholars have undertaken a review and expansion that led to this manual. The text is aimed at bachelor students of the courses in Mathematics, Physics and Engineering. Moreover, it presents the fundamental topics of Lagrangian mechanics and the dynamics of rigid bodies and variational principles, with a hint at Hamiltonian mechanics

Study of bent monolithic active pixel sensors for the ALICE inner tracking system 3

The ALICE experiment at CERN has planned an upgrade of the Inner Tracking System (ITS), named ITS3, for the LHC Long Shutdown 3, in 2025. The cornerstone of the upgrade is a new CMOS pixel sensor built in 65 nm technology and in bent-cylindrical configuration, replacing the inner layers of the existing detector, the ITS2. The ITS3 will reach much better tracking and vertexing performance, thanks to the improved spatial resolution and the much reduced material budget with respect to the previous Inner Tracking System. The aim of this thesis is to report on the analysis of the data collected at beam tests on new ALPIDE chips (used for ITS2, based on Monolithic Active Pixel Sensor, MAPS) which have been bent in a cylindrical configuration as foreseen for the ITS3. This is the first bending proof of concept for a silicon detector. In particular, data from beam test taken in 2020 have been studied through a data analysis framework that I have personally written to accomplish this task; the complexity of the data analysis is driven by the fact that each ALPIDE chip has a total of 1024x512 pixel MAPS and by the bent geometry of the sensor. In this thesis, the promising performances obtained by studying the sensor total efficiency and spatial resolution in different experimental configurations will be presented and discussed

Suppressor of Cytokine Signaling-3 (SOCS-3) induces Proprotein Convertase Subtilisin Kexin Type 9 (PCSK9) expression in hepatic HepG2 cell line

The suppressor of cytokine signaling (SOCS) proteins are negative regulators of the JAK/STAT pathway activated by proinflammatory cytokines, including the tumor necrosis factor (TNF-\u3b1). SOCS3 is also implicated in hypertriglyceridemia associated to insulin resistance. Proprotein convertase subtilisin kexin type 9 (PCSK9) levels are frequently found to be positively correlated to insulin resistance and plasma very low density lipoprotein (VLDL) triglycerides concentrations. The present study aimed to investigate the possible role of TNF-\u3b1 and JAK/STAT pathway on de novo lipogenesis and PCSK9 expression in HepG2 cells. TNF-\u3b1 induced both SOCS3 and PCSK9 in a concentration-dependent manner. This effect was inhibited by transfection with siRNA anti-STAT3, suggesting the involvement of the JAK/STAT pathway. Retroviral overexpression of SOCS3 in HepG2 cells (HepG2SOCS3) strongly inhibited STAT3 phosphorylation and induced PCSK9 mRNA and protein, with no effect on its promoter activity and mRNA stability. Consistently, siRNA anti-SOCS3 reduced PCSK9 mRNA levels, whereas an opposite effect was observed with siRNA anti- STAT3. In addition, HepG2SOCS3 express higher mRNA levels of key enzymes involved in the de novo lipogenesis, such as fattyacid synthase, stearoyl-CoA desaturase (SCD)-1, and apoB. These responses were associated with a significant increase of SCD-1 protein, activation of sterol regulatory element-binding protein-1c (SREBP-1), accumulation of cellular triglycerides, and secretion of apoB. HepG2SOCS3 show lower phosphorylation levels of insulin receptor substrate 1 (IRS-1) Tyr896 and Akt Ser473 in response to insulin. Finally, insulin stimulation produced an additive effect with SOCS3 overexpression, further inducing PCSK9, SREBP-1, fatty acid synthase, and apoB mRNA. In conclusion, our data candidate PCSK9 as a gene involved in lipid metabolism regulated by proinflammatory cytokine TNF- in a SOCS3-dependent manner

From Chirps to Random-FM Excitations in Pulse Compression Ultrasound Systems

Pulse compression is often practiced in ultrasound Non Destructive Testing (NDT) systems using chirps. However, chirps are inadequate for setups where multiple probes need to operate concurrently in Multiple Input Multiple Output (MIMO) arrangements. Conversely, many coded excitation systems designed for MIMO miss some chirp advantages (constant envelope excitation, easiness of bandwidth control, etc.) and may not be easily implemented on hardware originally conceived for chirp excitations. Here, we propose a system based on random-FM excitations, capable of enabling MIMO with minimal changes with respect to a chirp-based setup. Following recent results, we show that random-FM excitations retain many advantages of chirps and provide the ability to frequency-shape the excitations matching the transducers features.Comment: 4 pages, 4 figures. Post-print from conference proceedings. Note that paper in conference proceedings at http://dx.doi.org/10.1109/ULTSYM.2012.0117 has some rendering issue