Fluctuations in the Ensemble of Reaction Pathways

The dominant reaction pathway (DRP) is a rigorous framework to microscopically compute the most probable trajectories, in non-equilibrium transitions. In the low-temperature regime, such dominant pathways encode the information about the reaction mechanism and can be used to estimate non-equilibrium averages of arbitrary observables. On the other hand, at sufficiently high temperatures, the stochastic fluctuations around the dominant paths become important and have to be taken into account. In this work, we develop a technique to systematically include the effects of such stochastic fluctuations, to order k_B T. This method is used to compute the probability for a transition to take place through a specific reaction channel and to evaluate the reaction rate

Global Quantum Correlation in the Ising model

We study quantum correlations in an isotropic Ising ring under the effects of a transverse magnetic field. After characterizing the behavior of two-spin quantum correlations, we extend our analysis to global properties of the ring, using a figure of merit for quantum correlations that shows enough sensitivity to reveal the drastic changes in the properties of the system at criticality. This opens up the possibility to relate statistical properties of quantum many-body systems to suitably tailored measures of quantum correlations that capture features going far beyond standard quantum entanglement.Comment: Published in the International Journal of Quantum Information as part of the special issue devoted to "Quantum Correlations: entanglement and beyond

Noise Induced Phenomena in the Dynamics of Two Competing Species

Noise through its interaction with the nonlinearity of the living systems can give rise to counter-intuitive phenomena. In this paper we shortly review noise induced effects in different ecosystems, in which two populations compete for the same resources. We also present new results on spatial patterns of two populations, while modeling real distributions of anchovies and sardines. The transient dynamics of these ecosystems are analyzed through generalized Lotka-Volterra equations in the presence of multiplicative noise, which models the interaction between the species and the environment. We find noise induced phenomena such as quasi-deterministic oscillations, stochastic resonance, noise delayed extinction, and noise induced pattern formation. In addition, our theoretical results are validated with experimental findings. Specifically the results, obtained by a coupled map lattice model, well reproduce the spatial distributions of anchovies and sardines, observed in a marine ecosystem. Moreover, the experimental dynamical behavior of two competing bacterial populations in a meat product and the probability distribution at long times of one of them are well reproduced by a stochastic microbial predictive model.Comment: 23 pages, 8 figures; to be published in Math. Model. Nat. Phenom. (2016

The status of Orobanche crenata in Sicily and preliminary observations on Orobanche crenata susceptibility in Vicia faba

Since more than 10 years we are recording Orobanche crenata populations variations and testing traditional remedies to assess their applicability in a low impact agriculture that may be applied also in developing countries. Starting from the observation that often in C Sicily dense fields of Broadbean show lower Broomrape infestation, we did some preliminary observations on Orobanche crenata susceptibility in Vicia faba var. faba and Vicia faba var. equina with different agricultural techniques. First results show a higher resistance of the latter sowed at higher densities

A knowledge based architecture for the virtual restoration of ancient photos

Historical images are essential documents of the recent past. Nevertheless, time and bad preservation corrupt their physical supports. Digitization can be the solution to extend their \u201clives\u201d, and digital techniques can be used to recover lost information. This task is often difficult and time-consuming, if commercial restoration tools are used for the purpose. A new solution is proposed to help non-expert users in restoring their damaged photos. First, we defined a dual taxonomy for the defects in printed and digitized photos. We represented our restoration domain with an ontology and we created some rules to suggest actions to perform in case of some specific events. Classes and properties of the ontology are included into a knowledge base, that grows dynamically with its use. A prototypal tool and a web application version have been implemented as an interface to the database, and to support non-expert users in the restoration process

Upstream and downstream of recombinants biomolecules to health care industry

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characterization and manufacturing of a paraffin wax as fuel for hybrid rockets

The hybrid propulsion performed with paraffin waxes exhibits most attractive capabilities compared to solid or liquid engines, e.g., throttleability and re-ignition, alongside higher regression rates compared to the conventional hydroxyl terminated polybutadiene (HTPB) hybrid fuel. This is because the paraffin wax forms a thin and hydro-dynamically unstable liquid layer, and then enhances the regression rate with the entrainment of droplets from the liquid-gas interface. Nevertheless, some critical open points on the manufacturing of the paraffin fuel grains still persist, because the paraffin wax exhibits high shrinkage during the solidification phase, leading to the formation of cavities, cracks and internal rips, which may be detrimental to the mechanical properties and the structural integrity of the fuel grain. In this context, this paper deals with a wide calorimetric, thermo-mechanical and physical characterization of the paraffin wax selected to manufacture the hybrid rocket engines (HRE) fuel grain, in order to gain a thorough knowledge of the material necessary to avoid the formation of critical defects. Several manufacturing methods were investigated, and it was found that only laboratory scale processes, based on the use of a heated circular mould-piston apparatus, are able to avoid the formation of critical defects, with the application of both high temperature and pressure. Keywords: Paraffin wax, Hybrid rockets, Manufacturing, SASOL® 0907, Regression rat

Air transport and tourism flows to islands: A panel analysis for southern European countries

Air transport is an essential component of the tourism industry, and the number, frequency, and capacity of flight connections may influence the level of tourism demand, especially for island destinations. This paper evaluates the influence of air transport on tourism arrivals to selected islands in seven southern European Union countries to determine the nature of the relationship between tourist arrivals and air transport, specifically, whether air transport services generate tourism demand or merely enable touristic flows. The paper uses panel data and applies an econometric model with justifications for endogeneity and dynamic issues. Results show a moderate impact of transport infrastructures on generating additional tourist arrivals; however, the model shows that air transport is a prerequisite to developing tourism demand and is not the only determinant in increasing tourist arrivals. Tourist arrivals appear more a determinant than a consequence of changes in-flight connections