Some contributions of MAGIC to the physics ofcosmic rays

Cosmic ray interactions can be investigated indirectly in γ ray astronomy, with the observation of spectral and morphological features of certain classes of sources. MAGIC is a stereoscopic system of two γ ray telescopes, located at La Palma (Canaries), with access to the energy window between 50 GeV and 30 TeV. Sources of high relevance for the study of very high energy hadronic interactions are active galactic nuclei, as blazars and radio galaxies. MAGIC has detectedabout fifty such extragalactic objects; we will present some where theemission is explained with accelerated hadrons in interaction with ambient photons. We will also mention cosmic ray acceleration in galaxy clusters. Other than that, hadron-hadron interactions are supposed to take place in some supernova remnants in interaction with surrounding molecular clouds; we will show some results, in connection with cosmic rays of galactic origin. Finally, about other possible components, wewill mention the measurement of the diffuse electron and positron spectrum. Trustingly, the close connection between particle physics and astrophysics will contribute in future years to many new interesting observations

A Wick rotation for EPRL spin foam models

We show that the Euclidean and Lorentzian EPRL vertex amplitudes of covariant Loop Quantum Gravity are related through a ``Wick rotation'' of the real Immirzi parameter to purely imaginary values. Our result follows from the simultaneous analytic continuation of the algebras, group elements and unitary irreducible representations of the gauge groups $Spin(4)$ and $SL(2,\mathbb{C})$, applied to the decomposition of the two models in terms of $SU(2)$ invariants and booster functions.Comment: 25 pages, 1 figur

Magnetic dipole induced guided vortex motion

We present evidence of magnetically controlled guided vortex motion in a hybrid superconductor/ferromagnet nanosystem consisting of an Al film on top of a square array of permalloy square rings. When the rings are magnetized with an in-plane external field H, an array of point-like dipoles with moments antiparallel to H, is formed. The resulting magnetic template generates a strongly anisotropic pinning potential landscape for vortices in the superconducting layer. Transport measurements show that this anisotropy is able to confine the flux motion along the high symmetry axes of the square lattice of dipoles. This guided vortex motion can be either re-routed by 90 degrees by simply changing the dipole orientation or even strongly suppressed by inducing a flux-closure magnetic state with very low stray fields in the rings.Comment: 5 pages, 3 figure

Commento di Giovanni Gozzini a Un’età contro la storia. Saggio sulla rivoluzione del XXI secolo

Giovanni Gozzini nel suo commento al saggio di Giuseppe Carlo Marino su globalizzazione e crisi del “pensare storico” inquadra i cambiamenti nelle dinamiche economiche e sociali dell’ultimo trentennio in un più ampio mutamento del rapporto fra l’uomo e la realtà globalizzata del nuovo secolo. Gli eventi storici ricordati e i cambiamenti avvenuti sono organicamente relazionati così con le recenti evoluzioni del paradigma dello sviluppo economico e del dibattito culturale dei nostri giorni.In his comment to Giuseppe Carlo Marino’s essay about the globalization and crisis of “historical thought”, Giovanni Gozzini sets the changes in the social and economic dynamics in the last thirty years as a large alteration of the relationship between man and globalized reality of the new century. The mentioned historical events are systematically related with the latest evolutions of the economic model and the nowadays cultural debate

A simple model for simulation of growth and development in grapevine (Vitis vinifera L.). 2. Model validation

A simple model for the simulation of growth and development of Sangiovese vines has been presented in a previous paper. In this paper the model is validated to examine whether the description of the physiological relationships in the model describe the growth of grapevine (cv. Sangiovese) realistically. Furthermore, the model was adapted and validated for the simulation of growth of another cultivar (cv. Cabernet Sauvignon). Comparisons of simulated and experimental data for both cultivars reveal that the model made good predictions of vine growth for the whole growing season

Analysis of the thermal comfort in cycling athletes

Abstract This research presents a detailed analysis of thermal comfort in road cycling athletes. The data have been collected during experimental road test in prevision of the UCI Road World Championship 2013 (Florence-Tuscany, Italy), considering the different technical situations and the different environmental conditions expected as the most probable for the race's period. The analysis presented in this work is based on the in-situ measurements of both environmental and physiological parameters (i.e.: air temperature, relative humidity, true wind velocity, apparent wind velocity, skin temperature, clothing temperature, heat transfer resistance of the clothing, internal heat production) made over different athletes in different race conditions. The recorded data have been used as input for the model "RayMan" [1] , [2] for the assessment of the thermal comfort using thermal indices such as Predicted Mean Vote (PMV) and Physiological Equivalent Temperature (PET). It should be noted that the apparent wind velocity, which is a fundamental parameter in this kind of analysis but often disregarded, is evaluated in relationship with the movement and the effort made by the cyclist. The results obtained by the comparison of the PET and PMV indices with the measured skin temperature confirm the importance of considering the variation of environmental parameters in both training and strategy assessment and provide a working method which is believed to be innovative for the applied sport research

A simple model for simulation of growth and development in grapevine (Vitis vinifera L.). 1. Model description

A simple simulation model for growth of grapevine (Vitis vinifera L. cv. Sangiovese) is presented which mainly bases on analytical results from field experiments with plants free of visible stress and diseases. In the model leaf area development is defined as a function of temperature, biomass accumulation as a function of intercepted radiation and fruit growth is calculated from a linear increase of the fruit biomass index with time. The assumptions are discussed and comparisons between simulated and measured results are shown