Search results for " sand"

"Paroles de femmes pour la liberté : Georges Sand, Veuillez être leurs égales (avril 1848)"

2013

EXPERIMENTAL AND NUMERICAL EVALUATION OF THE MECHANICAL BEHAVIOUR OF GFRP SANDWICH PANELS

2007

This work deals with the analysis of the mechanical behaviour of a class of sandwich structures widely employed in marine constructions, constituted by fiber-glass laminate skins over PVC foam or polyester mat cores. In detail, a systematic experimental study and numerical simulations have shown that the theoretical prediction of the strength and the actual failure mechanism of these sandwich structures can be affected by significant errors, specially in the presence of prevalent shear loading. Moreover, because of the low shear stiffness and the elastic constants mismatch of the skins and core material, failure modes and strength are strongly influenced by eventual stresses orthogonal to t…

Inferential tools in penalized logistic regression for small and sparse data: A comparative study.

2016

This paper focuses on inferential tools in the logistic regression model fitted by the Firth penalized likelihood. In this context, the Likelihood Ratio statistic is often reported to be the preferred choice as compared to the ‘traditional’ Wald statistic. In this work, we consider and discuss a wider range of test statistics, including the robust Wald, the Score, and the recently proposed Gradient statistic. We compare all these asymptotically equivalent statistics in terms of interval estimation and hypothesis testing via simulation experiments and analyses of two real datasets. We find out that the Likelihood Ratio statistic does not appear the best inferential device in the Firth penal…

Spatial and temporal variation of community composition and species cover following dune restoration in the Devesa de Albufera (Valencia, Spain).

2015

Plant populations were reintroduced to the coastal dune bar of the Devesa de Albufera from 1988 to 2004; different coastline sections received different species composition and cover. With the aim to detect spatial and temporal variation of floristic diversity, we compared current species composition and cover across the length of the Devesa and across the dune bar with those imposed at the time of restoration. Non-metric multidimensional scaling (NMDS) detected significant differences both across the dune faces and across the coast sections. Differences across the dune faces reflect the sea-inland ecological gradient and resulted from a spatial rearrangement of plant populations: Calystegi…

Forming of aluminum foam sandwich panels: Numerical simulations and experimental tests

2006

Abstract The forming of the completed aluminium foam sandwich (AFS) panels would determine an improvement in the manufacturing of parts and panels. In this paper the authors have investigated the formability of AFS through experiments and numerical simulations. As far as the former are concerned, commercially prepared panels have been considered and bending and stamping processes have been taken into account. In addition, FEM analyses have been developed, utilizing a porous material model following the evolution of the material density throughout the forming processes.

First observations of oophagy in a wild population of the sand boa (Eryx jaculus)

2017

The sand boa Eryx jaculus (Linnaeus, 1758) is found in the southern Balkans, Middle East and North Africa (Sindaco et al., 2013). Only recently The presence of this species has been confirmed in Italy, in a small area of southern Sicily (Insacco et al., 2015). Knowledge of the sand boa in Sicily is limited with few data on geographical distribution, morphology, and habitat (Insacco et al., 2015; Faraone et al., 2017). Even at a global scale the biology of this species is little known due to its secretive habits (Tokar & Obst, 1993).

New techs, new threats: sfide e opportunità della rivoluzione blockchain

2021

Considering the current diffusion of blockchain technology in the most different fields, ranging from public governance to economics, from contractual applications to health, the contribution addresses the issue of the legal regulation of this new technology, precisely because of its vast applications. From the comparison between the European model and the American one, the approach of the European legislator ‒ despite the delay with which the institutions have addressed the issue, seems to show, as already happened in other areas, a more 'social oriented' perspective and based on a sort of 'democratization' of data compared to the American approach, more ‘business oriented’, where the scho…

Jauno tehnoloģiju pielietojums datu noliktavās

2015

Maģistra darbs „Jauno tehnoloģiju pielietojums datu noliktavās” balstās uz lielo datu analīzes realizācijas problēmu datu noliktavās. Darba mērķis ir izpētīt jaunās tehnoloģijas datu noliktavās un lielo datu apstrādes platformas piemērotību datu analīzes veikšanai praktiski realizējot iepriekš definētu lietojuma gadījumu. Rezultātā tika izpētītas lielo datu tehnoloģijas, kuras jau pielieto datu noliktavu risinājumos, un praktiski realizēts lietojuma gadījums datu analīzei izmantojot lielo datu apstrādes platformu Hortonworks, kā arī apzīmēts tālākais iespējamais datu noliktavu attīstības virziens lielo datu laikmetā.

Multiple Non-linear Reservoirs to Model Water Balance Components in Sandy Soils

2023

In the hydrologic literature, to model water flow in unsaturated soils, the Richards equation is usually applied, allowing the main components of the hydrologic cycle, as rainfall partitioning into surface runoff and infiltration, to be determined. The Richards equation is highly nonlinear, making very challenging to derive analytical solutions. Recently, for constant rainfall intensity, under the simplified hypothesis of gravity-driven infiltration, and by assuming a capacitance framework, a simplified solution of the Richards equation that considers the Brooks and Corey hydraulic conductivity function was suggested. By maintaining the assumption that the infiltration process is dominated …

Biodiversity, evolution and adaptation of fungi in exstreme environments

2013

Fungi play irreplaceable roles for ecosystem functioning. They may adopt different life styles, for example saprotrophs, symbionts or parasites: some species are cosmopolitan with a wide distribution and others, thanks to they ecological plasticity, may adapt to harsh environments precluded to most of life forms. In stressing conditions, their role is even more crucial for the recycling of organic matter or favouring nutrients uptake. When the conditions become really extreme and competion is low, fungi focus on extremotollerance and evolve peculiar competences to exploit natural or xenobiotic resources in the particular constraints imposed by the environment. This paper focuses on three di…