The evolution of the Italian Research and Education Network

Consortium GARR is the organization that plans and operates the Italian Research and Education Network. GARR facilitates the financial and technological synergies that led to the creation of the GARR network and enables its evolution. In this paper we briefly recall the existing GARR-G network infrastructure and discuss the new generation project GARR-X

Financing marriage in early modern Italy: innovative dowry funds in Florence and Bologna

Dowering maidens was a common concern in Renaissance and Early Modern Italian cities. As urban society recognized in un-dowered young women a potential threat to its moral and social stability, what had been a pious private effort became the business of specialized agencies, with the establishment of dowry funds. This paper examines the development of marriage endowment systems from the Florentine Monte delle doti, which in the main underwrote the marriage arrangements of the elite, to the Bolognese Monte del matrimonio, which was tailored to give respectable lower income families an opportunity to assemble dowries for young girls by investing their own savings. Finally, it focuses on the broad diffusion of charitable dowry funds, which dispensed dotal bequests through careful selection and scrutiny of recipients. Helping fathers to dower their daughters, dowry funds acted as a powerful stabilizing force, shoring up the pillar of early modern Italian society, the family, where it was weakest, i.e. among the urban lower classes. At the same time they were innovative institutions, bridging kinship, charity and finance

The Effect of Modeling Simultaneous Events on Simulation Results

This thesis explores the method that governs the prioritizing process for simultaneous events in relation to simulation results for discrete-event simulations. Specifically, it contrasts typical discrete-event simulation (DES) execution algorithms with how events are selected and ordered by the discrete-event system specification (DEVS) formalism. The motivation for this research stems from a desire to understand how the selection of events affects simulation output (i.e., response). As a particular use case, we briefly investigate the processing of simultaneous events by the Advanced Framework for Simulation, Integration and Modeling (AFSIM), a military discrete-event combat modeling and simulation package. To facilitate the building of classic DEVS-based models, the python software package PythonPDEVS is used. Initial results indicate that the explicit modeling of how simultaneous events are selected as promoted by the DEVS formalism plays a significant role on simulation results

Cartesian Bicategories II

The notion of cartesian bicategory, introduced by Carboni and Walters for locally ordered bicategories, is extended to general bicategories. It is shown that a cartesian bicategory is a symmetric monoidal bicategory

A Reliability Study of Phased Array Ultrasonic Inspections Applied to Aluminothermic Welds in Rails

Nowadays, long welded railway rails are achieved by means of aluminothermic and flush-butt welding processes. Compared to bolted joints, welds proved to be effective in terms of reduced wheel damage, ride comfort and maintenance. However, even if the event is inexplicably not considered in relevant standards, surface cracks often initiate within the welded and the heat affected regions of the foot, leading to brittle failure. On the subject, a recent work developed a probabilistic methodology for determining day-by-day failure probability. However, apart from this structural integrity study and few others, a complete damage tolerance approach should also consider the capability of nondestructive inspections. The latter is recognized as an essential input to define maintenance inspection intervals. The present work is focused on the capability assessment of Phased Array ultrasonic inspection applied to aluminothermic-welded joints by means of Probability of Detection curves, as a result of experimental and Model Assisted data samples

Acoustic emission-based monitoring of fatigue damage in CFRP-CFRP adhesively bonded joints

Adhesively bonded joints are being increasingly applied in modern structures. However, manufacturing defects and particularly harsh operative conditions may cause local debonding and catastrophic failures. Structural health monitoring (SHM) and non-destructive testing (NDT) procedures are then needed to evaluate the in-service structural integrity of adhesively bonded joints. In this research, an adhesively bonded single-lap joint, both adherends of which are manufactured using a carbon fibre-reinforced polymer (CFRP) composite, is subjected to constant amplitude fatigue loading. During such a test, the integrity and damage condition of the joint is continuously monitored using acoustic emission (AE), while the test itself is periodically interrupted in order to apply micro-computed tomography (??CT) to the specimen, with the aim of investigating the real features of the developing fatigue damage. The results show that, after suitable elaboration and filtering by means of pattern recognition algorithms, acoustic emission-based monitoring allows for effective identification and characterisation of the development of fatigue damage in adhesively bonded joints

Effect of the experimental technique onto R dependence of ΔKth

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Crack Detection in Railway Axle Using Horizontal and Vertical Vibration Measurements

In this paper, numerical investigations are carried out to assess the possible use of vibration measurements to identify the presence of a fatigue crack in railway axles. A non-linear finite element model of a cracked axle, reproducing the crack breathing mechanism, is introduced. The solid model of the axle is built in the ABAQUS FEM software and a crack is introduced in it. Numerical simulations are presented for two different types of axle: hollow ones, as in passenger trains, and solid ones, as in freight trains. Simulation are carried out for different possible locations of the crack and different measuring points for the monitoring equipment. Results indicate that the presence of a crack in the shaft affects not only the vertical vibration signal, but also the horizontal (perpendicular to the axle axis) one, generating harmonic components of bending vibration at frequencies that are multiple integers of the frequency of revolution of the axle. Results revealed also that the horizontal vibration provides promising indicators of axle fault development because the effect of various sources of disturbance, namely wheel out-of-roundness, can be more easily dealt with

A preliminary study of multi-parameter POD curves for a guided waves based SHM approach to lightweight materials

In view of an extensive literature about guided waves propagation, interaction and numerical simulation in platelike structures made of metallic and composite materials, a lack of information is pointed out regarding their reliability in structural health monitoring approaches. Typically, because of uncertainties in the inspection process, the capability of nondestructive testing systems is expressed by means of suitable probability of detection curves. Based on Berens’ model, a linear relationship is established between probability of detection and flaw size. Although the uncertain factors differ from a nondestructive inspection technique and a structural health monitoring approach, the same mathematical framework can be assumed. Hence, the authors investigated the application of a recently developed non-destructive testing Multi-Parameter POD approach to a guided waves based SHM one: numerical simulations as well as experimental data from flawed plates were combined to bring about a “master” POD curve. Once established, it can be used to build the POD curves of the single key factors as flaw size, orientation, structural attenuation and so on

Photochemical Organocatalytic Regio- and Enantioselective Conjugate Addition of Allyl Groups to Enals

We report the first catalytic enantioselective conjugate addition of allyl groups to α,β-unsaturated aldehydes. The chemistry exploits the visible-light-excitation of chiral iminium ions to activate allyl silanes towards the formation of allylic radicals, which are then intercepted stereoselectively. The underlying radical mechanism of this process overcomes the poor regio- and chemoselectivity that traditionally affects the conjugate allylation of enals proceeding via polar pathways. We also demonstrate how this organocatalytic strategy could selectively install a valuable prenyl fragment at the β-carbon of enals