Primi segnali di spontaneizzazione di Schinus molle L. (Anacardiaceae) in Sicilia.

Si riportano i primi casi di naturalizzazione di Schinus molle L. (Anacardiaceae) osservati in Sicilia

PLUMBAGO AURICULATA LAM. (Plumbaginaceae) IN SICILIA OCCIDENTALE: NUOVI DATI SULLA SUA DIFFUSIONE COME ESOTICA CASUALE

Plumbago auriculata Lam. (Plumbaginaceae) in western Sicily: new data on its spread as casual alien. In questa nota si fornisce un quadro aggiornato sui casi di naturalizzazione di Plumbago auriculata Lam. (Plumbaginaceae) nella Sicilia occidentale e sul suo status invasivo a livello nazionale ed internazionale. Questa xenofita viene segnalata per la prima volta in diverse aree delle province di Agrigento, Palermo e Trapani, dopo essere stata segnalata per la prima volta presso l'isola di Linosa, nell'arcipelago delle Pelagie

Energy-maximising model predictive control for a multi degree-of-freedom pendulum-based wave energy system

Renewable energy sources can be a solution for the recent pollution increasing scenario and the need for diversification of the energy market. Among such alternative sources,wave energy represents a viable solution, due to the its high power density and accessibility.Nonetheless, wave energy is still in phase of development, and a key stepping stone towards commercialisation is strongly linked to the availability of optimal control strategies for maximum energy harvesting. With its ability to handle system constraints and optimise power absorption directly, model predictive control (MPC) has gained popularity within the WEC community as a potential solution for the corresponding energy-maximising problem. In this study, an MPC strategy is developed for real-time control of the so-called PeWEC energy harvesting system,providing also a solution for the wave excitation estimation and forecasting problem, inherently required by the MPC controller to achieve optimal performance. Improved computational requirements are obtained via definition of a reduced control-oriented model, describing the dynamics of the system in a compact form. The performance of the proposed strategy is illustrated via a comprehensive numerical appraisal

Temperature dependence of thermal conductivity in 1D nonlinear lattices

We examine the temperature dependence of thermal conductivity of one dimensional nonlinear (anharmonic) lattices with and without on-site potential. It is found from computer simulation that the heat conductivity depends on temperature via the strength of nonlinearity. Based on this correlation, we make a conjecture in the effective phonon theory that the mean-free-path of the effective phonon is inversely proportional to the strength of nonlinearity. We demonstrate analytically and numerically that the temperature behavior of the heat conductivity $\kappa\propto1/T$ is not universal for 1D harmonic lattices with a small nonlinear perturbation. The computer simulations of temperature dependence of heat conductivity in general 1D nonlinear lattices are in good agreements with our theoretic predictions. Possible experimental test is discussed.Comment: 6 pages and 2 figures. Accepted for publication in Europhys. Let

Measuring the quality of teacher-child interaction in autistic disorder

The teacher-child relationship fulfils critical functions for the well being of the child, affecting emotive development, academic achievements, behavioral conducts and relationships with peers. The goal of the presented study is to compare the perceptions of the class teacher and of the support teacher concerning their relationship with subjects with autistic spectrum disorders (ASD; N=14; Mean age =90.07 months; SD=19.36) and with children of the control group (4 classmates per every subject of the experimental group, for a total of 56 pupils, Mean age = 80.36 months; SD=18.33). The perception by the teacher of the class, concerning the relationship with children with ASD, is characterized by higher levels of Conflict, and lower levels of Closeness, if compared with perceptions about the relationship with children of the control group (Conflict: t=-3.317; df= 14.931; p<0.01; Closeness: t= 5.638; df = 65; p < 0.001). The perception of the two teachers only correlates with regards to the Conflict dimension (r=0.769; p < 0.01). In reference to the child's adaptive skills only the social skills scale correlates with the Closeness. This is true in the perception of the support teacher (r=0.598; p<0.05). Finally, we take into account how the perception of the relationship relates with the socio-personal and professional data of the teachers and with the social features of the children

Data-based control synthesis and performance assessment for moored wave energy conversion systems: the PeWEC case

With a model-based control strategy, the effectiveness of the associated control action depends on the availability of a representative control-oriented model. In the case of floating offshore wave energy converters (WECs), the device response depends upon the interaction between mooring system, any mechanical parts, and the hydrodynamics of the floating body. This study proposes an approach to synthesise WEC controllers under the effect of mooring forces building a representative data-based linear model able to include any relevant dynamics. Moreover, the procedure is tested on the moored pendulum wave energy converter (PeWEC) by means of a high-fidelity mooring solver, OrcaFlex (OF). In particular, the control action is computed with and without knowledge of the mooring influence, in order to analyse and elucidate the effect of the station-keeping system on the harvested energy. The performance assessment of the device is achieved by evaluating device power on the resource scatter characterising Pantelleria, Italy. The results show the relevance of the mooring dynamics on the device response and final set of control parameters and, hence, a significant influence of the station-keeping system on control synthesis and extracted mechanical power

The effects of post-pasture woody plant colonization on soil and aboveground litter carbon and nitrogen along a bioclimatic transect.

We investigated the effects of woody plant colonization of abandoned pastures on soil and litter organic carbon (C) stocks and nitrogen (N) content along a bioclimatic transect in a semi-arid environment (Sicily, Italy). Soil samples were taken in three successional stages (grazed pasture, shrubland, forest) within each of three bioclimates (supramediterranean - \u201csupra\u201d, mesomediterranean - \u201cmeso\u201d, thermomediterranean - \u201cthermo\u201d). Organic C and N in litter and soil (0-10 cm and 10-30 cm depth) were determined, as well as soil bulk density. Especially at 0-10 cm depth, changes in C and N contents along successional stages differed among bioclimates. Soil organic carbon (SOC) stock decreased from pasture to shrubland and increased from shrubland to forest in \u201csupra\u201d, increased from pasture to shrubland and then remained stable in \u201cthermo\u201d, and was stable in \u201cmeso\u201d. Soil C/N ratio decreased with succession in \u201csupra\u201d, showed no significant trend in \u201cmeso\u201d, and increased with succession in \u201cthermo\u201d. Litter C stock increased with succession in \u201cmeso\u201d, increased from pasture to shrubland and decreased from shrubland to forest in \u201cthermo\u201d, and increased from pasture to shrubland and then remained stable in \u201csupra\u201d. Litter C/N ratio increased in \u201cthermo\u201d and \u201csupra\u201d from pasture to shrubland and from shrubland to forest, but did not change significantly with succession in \u201cmeso\u201d. The different trends in SOC among bioclimates may be caused by changes in the importance of litter input, litter decay rate and mineralization. Successional changes in \u201cmeso\u201d and \u201csupra\u201d appeared to be most affected by litter quality, while those in \u201cthermo\u201d appeared to be strongly influenced by limited litter decay due to low soil moisture and high temperature

The inhomogeneous mechanical behaviour of Ascending Thoracic Aortic Aneurism (ATAA)

Surgical management of ascending thoracic aortic aneurysms (aTAAs) relies on maximum diameter, growth rate, and presence of connective tissue disorders. The surgical decision however is often not considering that dissection and rupture do occur in patients who do not meet criteria for surgical repair [1,2]. In this study the authors aim to investigate the mechanical properties of aTAAs to be implemented in computational biomechanics models for a preclinical risk evaluation. Additionally, in some recent studies, some data about the biomechanical properties of the aTAAs have been reported [3], but without any relation to bicuspidal or tricuspidal aTAA. The aim of this study was to investigate aTAA mechanical properties using a biaxial system to compare the circumferential and axial stress-strain relations for bicuspidal and tricuspidal aTAAs