Hurford Conditionals

Compare the following conditionals: 'If John is not in Paris, he is in France' versus 'If John is in France, he is not in Paris.' The second sounds entirely natural, whereas the first sounds quite strange. This contrast is puzzling, because these two conditionals have the same structure at a certain level of logical abstraction, namely 'If ¬p+, then p.' We argue that existing theories of informational oddness do not distinguish between these conditionals. We do not have an account of the divergence in judgments about the two, but we think this is a fascinating puzzle which we pose here in the hope others will be able to solve it

Cut-off Characterisation of Energy Spectra of Bright Fermi Sources: Current instrument limits and future possibilities

In this paper some of the brightest GeV sources observed by the Fermi-LAT were analysed, focusing on their spectral cut-off region. The sources chosen for this investigation were the brightest blazar flares of 3C~454.3 and 3C~279 and the Vela pulsar with a reanalysis with the latest Fermi-LAT software. For the study of the spectral cut-off we first explored the Vela pulsar spectrum, whose statistics in the time interval of the 3FGL catalog allowed strong constraints to be obtained on the parameters. We subsequently performed a new analysis of the flaring blazar SEDs. For these sources we obtained constraints on the cut-off parameters under the assumption that their underlying spectral distribution is described by a power-law with a stretched exponential cut-off. We then highlighted the significant potential improvements on such constraints by observations with next generation ground based Cherenkov telescopes, represented in our study by the Cherenkov Telescope Array (CTA). Adopting currently available simulations for this future observatory, we demonstrate the considerable improvement in cut-off constraints achievable by observations with this new instrument when compared with that achievable by satellite observations.Comment: total number of pages 24, including 6 pages of references. Accepted by Astroparticle Physic

Studio teorico-sperimentale sulla asportazione mediante laser di polimeri acrilici al fine della realizzazione di prototipi

SOMMARIO: Questo lavoro ha come oggetto l’analisi di una tecnica innovativa di asportazione di materiale su di un polimero con adeguate caratteristiche (il polimetilmetacrilato PMMA), attraverso un fascio laser a CO2, con lo scopo di realizzare cavità tridimensionali da utilizzare come stampi di colata per la produzione in serie di prototipi. Nella prima fase di questo studio, si esamina la tecnica della vaporizzazione laser della superficie del polimero fornendo un semplice modello in grado di prevedere la profondità e la larghezza delle tracce ottenute. In particolare viene esaminata l’influenza della sequenza di taglio, del numero di passate, della velocità di scansione e della potenza associata alla radiazione laser. Viene presentato, inoltre, un metodo pratico per variare il profilo delle tracce usando più scansioni sovrapposte. Nella seconda fase è stata realizzata l’asportazione selettiva di uno strato di materiale attraverso l’affiancamento di più tracce rettilinee e variando il parametro del passo di scansione. Nella terza parte di questo studio, sono stati esaminati gli effetti della vaporizzazione di strati successivi sulla rugosità della superficie e sulla profondità di asportazione. Si evidenzia che, con la tecnica sviluppata, la profondità di asportazione varia proporzionalmente con il numero degli strati mentre la rugosità tende ad assumere un valore costante (Rz(DIN)=[80-90]μm). Tutte le prove sono state ripetute due volte. Infine, utilizzando i risultati sperimentali, sono stati realizzati diversi prototipi colando resina siliconica all’interno delle complesse impronte, ricavate per vaporizzazione laser nel PMMA, che non sarebbero potute essere ottenute mediante tecniche convenzionali di asportazione di materiale. Theoretical and experimental analysis of a laser machining technique on acrylic polymers for prototypes fabrication Keywords: laser, vaporisation, polymethylmethacrilate, prototypes ABSTRACT: This work focuses on an innovative technique of complex CO2 laser machining in order to create, by vaporisation of a suitable polymeric material (polymethylmethacrilate PMMA), three-dimensional cavities to be used as molds for rapidly producing of prototypes. At the beginning the cutting process with the laser beam is analized through theoretical models for estimating the shape depth and width of micro-slots, obtained by vaporisation of the polymeric surface. In particular, the influence of the cutting sequence, the number of passes, the laser beam speed and the radiant flux are examinated. A method of changing the channel profile using multiple passes in the same position is also presented. In the second step of this work, microablated surfaces are generated using multiple overlapping grooves and varying the scan spacing parameter. In the third step the effects of machining layer by layer on surface roughness and removal depth are investigated; with the developed technique it’s proved that removal depth varies proportionally with number of layers machined while surface roughness tends to assume a costant value(Rz(DIN)=[80-90]μm). All tests have been repeated twice. Using all the acquired data, several prototypes have been finally carried out casting silicone resin into three-dimensional PMMA molds manufactured by the proposed technique and not obtainable by conventional removal processes

How the Migration Process drives the establishment of a Psychological Home: An Italian mixed methods study in the light of Community Psychology

The concept of "home" holds profound significance for individuals, yet its definition becomes complex amid changes in living environments, particularly for migrants. This doctoral project explores how migrants construct their psychological sense of home and its impact on well-being. Defense mechanisms, such as idealization or assimilation, play a pivotal role in shaping migrants' psychological sense of home, evolving over time. Despite recognizing the significance of home in migrants' lives, there is a research gap in understanding their psychological sense of home. The study adopts a community psychology approach to migration research, emphasizing relational aspects, contextual interactions, and intervention development. Italy's social scenario, marked by cultural pluralism, makes this approach particularly relevant. The thesis comprises five chapters, offering a theoretical framework, exploring the concept of home, presenting the research question, describing the Italian context, and detailing the methodology. The main studies include a literature review, qualitative interviews, and a quantitative study, each contributing to a comprehensive understanding of migrants' psychological sense of home. The final chapter integrates findings, elucidating the process of establishing a psychological home for migrants. It explores bridging gaps between individual and community-focused migration studies, highlights study limitations, suggests future research, and outlines practical implications. The study contributes valuable insights into the intricate relationship between migrants' psychological sense of home, well-being, and community interactions