TUTELA DEI DIRITTI E TIME LIMITS: UNO STUDIO ALLA LUCE DELLA GIURISPRUDENZA EUROPEA

The purpose of this comparative law thesis is to investigate the measure and the modalities in which time limits to the exercise of a right influence its effectiveness. In particular the study focus on the evolutionary aspect of the right of the prescription (limitation of action using common law expression) and the incidence that national and European jurisprudence has on it. This analysis has shown that rules on time limits for bringing judicial claims are designed to ensure the proper administration of justice and compliance with both the principle of legal certainty and equity, especially in guarantying the right of access to a court. This aim should be achieved by a casuistic approach by Courts. Set the premises, the analysis look at recent reforms of the right of limitation of action and soft law instruments, to extrapolate general trends in Europe and highlight the inadequacy of the Italian discipline at last

Capillary breakup and electrospinning of PA6 solutions containing FeCl3: experimental findings and correlations

In several applications, ranging from electronic to chemical sensing, great interest has grown for the exploitation of conducting polymer nanofibers, whose processing is, however, not straightforward, due to polymer low solubility and presence of rigid backbones. An interesting method to overcome this issue consists in the electrospinning of a spinnable polymer to obtain a template for the successive in situ polymerization of the conducting polymer monomers. Considering PANI nanofibers, a suitable template can be electrospun from PA6 solutions in formic acid containing FeCl3. In this system, the ionic salt may perturb or prevent H-bonds formation between amide groups of PA6 backbones: this could modify solution viscoelasticity, and thus affect fibres morphology. The aim of the present work is to identify the effect of FeCl3 on the solution rheological behaviour and to correlate it to electrospun fibres morphology. To this aim, solutions at several salt content underwent electrospinning and were characterized both in shear, by rotational rheometry, and extension, by capillary breakup rheometry, while fibres morphology and crystallinity were evaluated through SEM and DSC. The rheological analysis enlightens that a critical FeCl3 content exists above which the viscous component of the viscoelastic response becomes predominant. At the same concentration, the SEM observations of the electrospun fibres show the formation of severely inhomogeneous structures. A correlation between these results is proposed through the adimensional analysis of competing viscoelastic stabilization and surface tension-driven instability phenomena. Besides the aforementioned effects, the FeCl3 content affects also fibre crystallinity, as above a critical concentration fibres turn out to be completely amorphous. Interestingly, this concentration coincides with the one at which a transition is observed in the rheological behaviour

Measurements of heavy ion beam losses from collimation

The collimation efficiency for Pb ion beams in the LHC is predicted to be lower than requirements. Nuclear fragmentation and electromagnetic dissociation in the primary collimators create fragments with a wide range of Z/A ratios, which are not intercepted by the secondary collimators but lost where the dispersion has grown sufficiently large. In this article we present measurements and simulations of loss patterns generated by a prototype LHC collimator in the CERN SPS. Measurements were performed at two different energies and angles of the collimator. We also compare with proton loss maps and find a qualitative difference between Pb ions and protons, with the maximum loss rate observed at different places in the ring. This behavior was predicted by simulations and provides a valuable benchmark of our understanding of ion beam losses caused by collimation.Comment: 12 pages, 20 figure

The "Multimat" experiment at CERN HiRadMat facility: advanced testing of novel materials and instrumentation for HL-LHC collimators

The increase of the stored beam energy in future particle accelerators, such as the HL-LHC and the FCC, calls for a radical upgrade in the design, materials and instrumentation of Beam Intercepting Devices (BID), such as collimators Following successful tests in 2015 that validated new composite materials and a novel jaw design conceived for the HL-LHC collimators, a new HiRadMat experiment, named “HRMT36-MultiMat”, is scheduled for autumn 2017. Its objective is to determine the behaviour under high intensity proton beams of a broad range of materials relevant for collimators and beam intercepting devices, thin-film coatings and advanced equipment. The test bench features 16 separate target stations, each hosting various specimens, allowing the exploration of complex phenomena such as dynamic strength, internal damping, nonlinearities due to anisotropic inelasticity and inhomogeneity, effects of energy deposition and radiation on coatings. This paper details the main technical solutions and engineering calculations for the design of the test bench and of the specimens, the candidate target materials and the instrumentation system

Analysis of phase patterns in photochromic polyurethanes by a holographic approach

Photochromic polyurethanes based on diarylethene units show a large reversible modulation of refractive index in the Vis-NIR spectral region. The change of refractive index in the material is easily induced by visible laser illumination, without any optical or chemical post-process. In this paper, patterns at the micron scale range have been written by a suitable direct laser writing machine and characterized at 1550 nm by means of a digital holographic approach. The refractive index profile has been retrieved, its dependence on the film thickness and writing speed was shown. The writing process has also been modelled by means of a kinetic model, showing theoretically the dependence of the pattern width and profile on the writing conditions. It is demonstrated that the photochromic films are suitable for developing a reconfigurable platform for complex phase patterns working in the NIR. © 2015 Optical Society of America

Membrane Environment Enables Ultrafast Isomerization of Amphiphilic Azobenzene

G.M.P. and E.C. contributed equally to this work. G.M.P. acknowledges the financial support from Fondazione Cariplo, grant no. 2018-0979. The authors thank the financial support from the EU Horizon 2020 Research and Innovation Programme under Grant Agreement No. 643238 (SYNCHRONICS). The authors also thank Dr. Daniele Viola for helping with the analysis of the TA data.The non‐covalent affinity of photoresponsive molecules to biotargets represents an attractive tool for achieving effective cell photo‐stimulation. Here, an amphiphilic azobenzene that preferentially dwells within the plasma membrane is studied. In particular, its isomerization dynamics in different media is investigated. It is found that in molecular aggregates formed in water, the isomerization reaction is hindered, while radiative deactivation is favored. However, once protected by a lipid shell, the photochromic molecule reacquires its ultrafast photoisomerization capacity. This behavior is explained considering collective excited states that may form in aggregates, locking the conformational dynamics and redistributing the oscillator strength. By applying the pump probe technique in different media, an isomerization time in the order of 10 ps is identified and the deactivation in the aggregate in water is also characterized. Finally, it is demonstrated that the reversible modulation of membrane potential of HEK293 cells via illumination with visible light can be indeed related to the recovered trans→cis photoreaction in lipid membrane. These data fully account for the recently reported experiments in neurons, showing that the amphiphilic azobenzenes, once partitioned in the cell membrane, are effective light actuators for the modification of the electrical state of the membrane.Fondazione Cariplo. Grant Number: 2018‐0979EU Horizon 2020 Research and Innovation Programme. Grant Number: 64323

Preliminary Exploratory Study of Different Phase II Collimators

The LHC collimation system is installed and commissioned in different phases, following the natural evolution of the LHC performance. To improve cleaning efficiency towards the end of the low beta squeeze at 7TeV, and in stable physics conditions, it is foreseen to complement the 30 highly robust Phase I secondary collimators with low impedance Phase II collimators. At this stage, their design is not yet finalized. Possible options include metallic collimators, graphite jaws with a movable metallic foil, or collimators with metallic rotating jaws. As part of the evaluation of the different designs, the FLUKA Monte Carlo code is extensively used for calculating energy deposition and studying material damage and activation. This report outlines the simulation approach and defines the critical quantities involved

Ring closing reaction in diarylethene captured by femtosecond electron crystallography

The photoinduced ring-closing reaction in diarylethene, which serves as a model system for understanding reactive crossings through conical intersections, was directly observed with atomic resolution using femtosecond electron diffraction. Complementary ab initio calculations were also performed. Immediately following photoexcitation, subpicosecond structural changes associated with the formation of an open-ring excited-state intermediate were resolved. The key motion is the rotation of the thiophene rings, which significantly decreases the distance between the reactive carbon atoms prior to ring closing. Subsequently, on the few picosecond time scale, localized torsional motions of the carbon atoms lead to the formation of the closed-ring photoproduct. These direct observations of the molecular motions driving an organic chemical reaction were only made possible through the development of an ultrabright electron source to capture the atomic motions within the limited number of sampling frames and the low data acquisition rate dictated by the intrinsically poor thermal conductivity and limited photoreversibility of organic materials

Design, construction, and beam tests of a rotatable collimator prototype for high-intensity and high-energy hadron accelerators

A rotatable-jaw collimator design was conceived as a solution to recover from catastrophic beam impacts which would damage a collimator at the Large Hadron Collider (LHC) or its High-Luminosity upgrade (HL-LHC). One such rotatable collimator prototype was designed and built at SLAC and delivered to CERN for tests with LHC-type circulating beams in the Super Proton Synchrotron (SPS). This was followed by destructive tests at the dedicated High Radiation to Materials (HiRadMat) facility to validate the design and rotation functionality. An overview of the collimator design, together with results from tests without and with beam are presented

Heavy ion induced radiation effects in novel molybdenum-carbide graphite composite materials

Innovative molybdenum-carbide graphite (Mo-Gr) composites were specifically developed for high energy physics applications. These materials are showing a very promising combination of thermal, electrical, and mechanical properties for application in beam protection elements for high-power accelerators. To date very little is known about their structural and dimensional stability and about degradation of functional properties under irra- diation. Within the EU, FP7, EuCARD-2 project [1], an intense campaign for testing radiation hardness using different particle beams and energies is taking place at GSI Helmholtzzentrum as well as at Brookhaven National Laboratory (USA) and Kurchatov Institute ( Russia)