Ground states in complex bodies

A unified framework for analyzing the existence of ground states in wide classes of elastic complex bodies is presented here. The approach makes use of classical semicontinuity results, Sobolev mappinngs and Cartesian currents. Weak diffeomorphisms are used to represent macroscopic deformations. Sobolev maps and Cartesian currents describe the inner substructure of the material elements. Balance equations for irregular minimizers are derived. A contribution to the debate about the role of the balance of configurational actions follows. After describing a list of possible applications of the general results collected here, a concrete discussion of the existence of ground states in thermodynamically stable quasicrystals is presented at the end.Comment: 30 pages, in print on ESAIM-COC

Phase transitions between Reissner-Nordstrom and dilatonic black holes in 4D AdS spacetime

We study Einstein-Maxwell-dilaton gravity models in four-dimensional anti-de Sitter (AdS) spacetime which admit the Reissner-Nordstrom (RN) black hole solution. We show that below a critical temperature the AdS-RN solution becomes unstable against scalar perturbations and the gravitational system undergoes a phase transition. We show using numerical calculations that the new phase is a charged dilatonic black hole. Using the AdS/CFT correspondence we discuss the phase transition in the dual field theory both for non-vanishing temperatures and in the extremal limit. The extremal solution has a Lifshitz scaling symmetry. We discuss the optical conductivity in the new dual phase and find interesting behavior at low frequencies where it shows a "Drude peak". The resistivity varies with temperature in a non-monotonic way and displays a minimum at low temperatures which is reminiscent of the celebrated Kondo effect.Comment: 19 pages - v2: minor corrections and additional references -v3: Figs.5 changed and additional comments. Version accepted in JHE

Size and timescale of epidemics in the SIR framework

The most important features to assess the severity of an epidemic are its size and its timescale. We discuss these features in a systematic way in the context of SIR and SIR-type models. We investigate in detail how the size and timescale of the epidemic can be changed by acting on the parameters characterizing the model. Using these results and having as guideline the COVID-19 epidemic in Italy, we compare the efficiency of different containment strategies for contrasting an epidemic diffusion such as social distancing, lockdown, tracing, early detection and isolation.Comment: 16 pages in PhysRev format, 12 figures; some superposition with arXiv:2004.11633, in particular for the application par

A framework for probabilistic seismic risk assessment of NG distribution networks

Lifelines are essential infrastructures for human activities and the economic developm ent of a region. Lifelines vulnerability reduction is an actual question, particularly with reference to NaTech events, like earthquakes. In this regard, worldwide past seismic experiences revealed heavy damages to NG distribution networks. It is therefore essential to perform seismic risk assessment of NG buried pipelines systems with the aim to identify potential criticalities and avoid significant consequences. For such reasons, this work illustrates the proposal of a probabilistic framework for seismic risk assessment of NG lifelines. The proposed procedure is subsequently applied to a specific case study in Italy to highlight its feasibility

Modern technologies in Endodontics

AbstractAimIn Endodontics, a complete chemo-mechanical cleansing of the root canal system is essential to achieving success, which is gained through adequate tridimensional obturation of the endodontic space.Materials and methodsToday, thanks to modern technologies as Operative Microscope, ultrasonic tips, M-Wire Files, devices to activate irrigation and tridimensional obturation performed with thermo plasticized gutta-percha, satisfactory results can be obtained.ResultsThis study shows all the technologies that are available today to increase the chemo-mechanical cleansing and obturation of the entire and complicated endodontic system.ConclusionsThe positive results highlighted by these clinical cases demonstrate how the use of modern technologies are essential to avoid iatrogenic injury, and guarantee, on the other hand, safe and reproducible results

Bovine jugular vein as aortic enlargement patch in the Norwood procedure

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Modern technologies in Endodontics

Abstract Aim In Endodontics, a complete chemo-mechanical cleansing of the root canal system is essential to achieving success, which is gained through adequate tridimensional obturation of the endodontic space. Materials and methods Today, thanks to modern technologies as Operative Microscope, ultrasonic tips, M-Wire Files, devices to activate irrigation and tridimensional obturation performed with thermo plasticized gutta-percha, satisfactory results can be obtained. Results This study shows all the technologies that are available today to increase the chemo-mechanical cleansing and obturation of the entire and complicated endodontic system. Conclusions The positive results highlighted by these clinical cases demonstrate how the use of modern technologies are essential to avoid iatrogenic injury, and guarantee, on the other hand, safe and reproducible results