Sviluppo e sperimentazione di un elettrolita polimerico a membrana per PEMFCs (Polymer Electrolyte Membrane Fuel Cells)

Il presente lavoro si propone di realizzare un prototipo di membrana polimerica a conducibilità protonica con: 1)caratteristiche di trasporto (anche selettivo) adeguate alla tecnologia delle celle a combustibile; 2)conducibilità ionica simile o superiore a quella del Nafion®; 3)costi contenuti; Sono state impiegate le seguenti metodologie: a)metodi di preparazione di membrane per “evaporation-casting”; b)determinazione di conducibilità mediante spettroscopia ad impedenza elettrochimica; c)sperimentazione diretta in cella a combustibile; d)determinazione di permeabilità; e)analisi morfologica al S.E.M

Dynamic facilitation picture of a higher-order glass singularity

We show that facilitated spin mixtures with a tunable facilitation reproduce, on a Bethe lattice, the simplest higher-order singularity scenario predicted by the mode-coupling theory (MCT) of liquid-glass transition. Depending on the facilitation strength, they yield either a hybrid glass transition or a continuous one, with no underlying thermodynamic singularity. Similar results are obtained for facilitated spin models on a diluted Bethe lattice. The mechanism of dynamical arrest in these systems can be interpreted in terms of bootstrap and standard percolation and corresponds to a crossover from a compact to a fractal structure of the incipient spanning cluster of frozen spins. Theoretical and numerical simulation results are fully consistent with MCT predictions.Comment: 4 pages, 3 figures; minor change

Field trip to the Ischia resurgent caldera, a journey across an active volcano in the Gulf of Naples

Ischia is one of the most impressive examples of post-caldera resurgence in the world, with its almost 1,000 m of uplift in less than 30 ka. This three-days field trip will lead the participants through the geological and volcanological history of the island, illustrating the volcanic and related hazardous phenomena threatening about 50,000 inhabitants. Effusive and explosive eruptions, catastrophic earthquakes and huge debris-avalanches struck the island that, since Neolithic times, experienced a complex history of alternating human colonization and natural disasters. The field trip consists of three routes: 1) the circumnavigation of the island, aimed to outline its main volcanological, geomorphological and tectonic features and to observe the oldest volcanic rocks exposed, stimulating discussions about coastal evolution and the relationships between volcanism, volcano-tectonism and slope instability; 2) an onland excursion on peculiar aspects of the products related to Ischia more recent period of volcanic activity; 3) a route focusing on the Mt. Epomeo Green Tuff caldera forming eruptions (55-60 ka), encouraging a discussion on the dynamics of the intracalderic resurgence and the geomorphological evolution of the Mt. Epomeo slopes, with ongoing Mass Rock Creep (MRC) processes culminating in rockavalanche, debris-avalanche and lahar deposits

Imaging follow-up after liver transplantation

Liver transplantation (LT) represents the best treatment for end-stage chronic liver disease, acute liver failure and early stages of hepatocellular carcinoma. Radiologists should be aware of surgical techniques to distinguish a normal appearance from pathological findings. Imaging modalities, such as ultrasound, CT and MR, provide for rapid and reliable detection of vascular and biliary complications after LT. The role of imaging in the evaluation of rejection and primary graft dysfunction is less defined. This article illustrates the main surgical anastomoses during LT, the normal appearance and complications of the liver parenchyma and vascular and biliary structures.Liver transplantation (LT) represents the best treatment for end-stage chronic liver disease, acute liver failure and early stages of hepatocellular carcinoma. Radiologists should be aware of surgical techniques to distinguish a normal appearance from pathological findings. Imaging modalities, such as ultrasound, CT and MR, provide for rapid and reliable detection of vascular and biliary complications after LT. The role of imaging in the evaluation of rejection and primary graft dysfunction is less defined. This article illustrates the main surgical anastomoses during LT, the normal appearance and complications of the liver parenchyma and vascular and biliary structures

Accidental impacts on historical and architectural heritage in port areas: the case of Brindisi

Most port areas can produce impacts on the historical and architectural heritage, leading to rapid pathological effects and generating high risks in terms of damages and losses of historical, artistic, and cultural values. In effect, in addition to stationary actions (air pollution, waste, water discharge), port activities could generate exceptional impacts: the so-called “major accidents”, such as fires or explosions and chemical releases. The present contribution analyses and discusses a given case, the port of Brindisi, suggesting a methodology for the assessment of exceptional impacts in ports, in order to identify those potential accidents and their effects on the historical landscape. It points out that, as often occurs in ports, the most frequent major accidents are caused by activities involving hazardous materials. The methodology proposed for this given case aims to demonstrate that in the historical port areas, such as in the Mediterranean Sea, the development and management should be accompanied, or even oriented to the protection of the historical and cultural landscape.Postprint (author's final draft

A systematic analysis of the XMM-Newton background: III. Impact of the magnetospheric environment

A detailed characterization of the particle induced background is fundamental for many of the scientific objectives of the Athena X-ray telescope, thus an adequate knowledge of the background that will be encountered by Athena is desirable. Current X-ray telescopes have shown that the intensity of the particle induced background can be highly variable. Different regions of the magnetosphere can have very different environmental conditions, which can, in principle, differently affect the particle induced background detected by the instruments. We present results concerning the influence of the magnetospheric environment on the background detected by EPIC instrument onboard XMM-Newton through the estimate of the variation of the in-Field-of-View background excess along the XMM-Newton orbit. An important contribution to the XMM background, which may affect the Athena background as well, comes from soft proton flares. Along with the flaring component a low-intensity component is also present. We find that both show modest variations in the different magnetozones and that the soft proton component shows a strong trend with the distance from Earth.Comment: To appear in Experimental Astronomy. Presented at AHEAD Background Workshop, 28-30 November 2016. Rome, Ital

A Systematic Analysis of the XMM-Newton Background: I. Dataset and Extraction Procedures

XMM-Newton is the direct precursor of the future ESA ATHENA mission. A study of its particle-induced background provides therefore significant insight for the ATHENA mission design. We make use of about 12 years of data, products from the third XMM-Newton catalog as well as FP7 EXTraS project to avoid celestial sources contamination and to disentangle the different components of the XMM-Newton particle-induced background. Within the ESA R&D AREMBES collaboration, we built new analysis pipelines to study the different components of this background: this covers time behavior as well as spectral and spatial characteristics.Comment: To appear in Experimental Astronomy, presented at AHEAD Background Workshop, 28-30 November 2016, Rome, Italy. 12 pages, 6 figure