Search results for " scienza"

PLLA-fibrin scaffolds for Vascular Tissue Engineering

2013

Thermal and rheological characterisation of a thermoset matrix for filament winding modelling

2004

Rheo-kinetic behaviour of an epoxy resin, coupled with an aliphatic polyamines hardener, used in fibre reinforced plastics, was analysed comparing experimental data to theoretical models. Then the modelling of technological filament winding process for thermoset matrix composites, developed through a numerical code realized with MATLAB, is reported. The model includes winding and curing phase decoupling the manufacturing process into sub-models. Four sub-models are used: fibre motion, thermal, kinetic and rheological model. Considerable differences are obtained in process condition, using several thermal treatments. The numerical modelling helps to detect the process conditions to optimise…

PLA based biocomposites reinforced with Posidonia oceanica leaves

2018

Abstract Biocomposites can valorize some natural products related to natural processes or crop and waste industries. In this work, leaves of Posidonia oceanica (PO), dominant sea grass in the Mediterranean Sea, were used to prepare PLA based biocomposites. Materials were prepared by melt mixing PLA with PO as filler. The morphology as well as the mechanical and thermal properties of PLA/PO composites were evaluated and related with the influence of the content and size of PO. Moreover, the experimental elastic moduli of the biocomposites was modelled employing the Halpin–Tsai (HT) model. Furthermore, in order to take into consideration the high porosity of PO leaves, the HT parameters relat…

Use of Biochar as Filler for Biocomposite Blown Films: Structure-Processing-Properties Relationships

2021

In this work, biocomposite blown films based on poly(butylene adipate-co-terephthalate) (PBAT) as biopolymeric matrix and biochar (BC) as filler were successfully fabricated. The materials were subjected to a film-blowing process after being compounded in a twin-screw extruder. The preliminary investigations conducted on melt-mixed PBAT/BC composites allowed PBAT/BC 5% and PBAT/BC 10% to be identified as the most appropriate formulations to be processed via film blowing. The blown films exhibited mechanical performances adequate for possible application as film for packaging, agricultural, and compost bags. The addition of BC led to an improvement of the elastic modulus, still maintaining h…

Federigo Enriques matematico e filosofo

2021

Federigo Enriques ha caratterizzato la cultura italiana, nella duplice connotazione scientifica e umanistica, tra la fine dell'Ottocento e la prima metà del Novecento. Enriques ha elaborato un modello culturale incentrato sul confronto scienza e filosofia.

Giustizia sociale e dignità umana. Da individui a persona, di M.C. Nussbaum

2007

Filosofia e scienza: per una prospettiva relazionale

2009

Attraverso l''analisi di alcune fondamentali posizioni filosofiche novecentesche (Croce, Wittgenstein, Husserl, Heidegger, Rorty, Popper) si mette in rilievo le insufficienti o addirittura scorrette caratterizzazioni del discorso filosofico e di quello scientifico di per sé, e dell''uno rispetto all''altro, ragionando sulle mdoalità e sugli scopi della razionalità scientifica e di quella filosofica, e mettendone in luce l''unica matrice umana nella sua ineludibile storicità e finitezza ma insieme nella sua peculiare capacità di progresso.

Performance-Based Engineering of Wind-Excited Structures: A General Methodology

2016

The current prescriptive design philosophy that relies simply on meeting requirements stipulated in standards is shifting towards a performance-based design (PBD) approach for achieving designs that rationally meet society’s need for a truly safe built environment. Extensive research has facilitated the successful adoption of PBD in earthquake engineering, but the same cannot be said for wind engineering. Therefore, the need exists to initiate a similar effort by defining a framework that fully embraces the concepts of PBD during the design of building systems to resist severe wind events. This paper illustrates the development of such a PBD framework. In particular, a method is proposed sp…

Finite element method on fractional visco-elastic frames

2016

Viscoelastic behavior is defined by fractional operators.Quasi static FEM analysis of frames with fractional constitutive law is performed.FEM solution is decoupled into a set of fractional Kelvin Voigt elements.Proposed approach could be easily integrated in existing FEM codes. In this study the Finite Element Method (FEM) on viscoelastic frames is presented. It is assumed that the Creep function of the constituent material is of power law type, as a consequence the local constitutive law is ruled by fractional operators. The Euler Bernoulli beam and the FEM for the frames are introduced. It is shown that the whole system is ruled by a set of coupled fractional differential equations. In q…

The effect of vertical ground movement on masonry walls simulated through an elastic–plastic interphase meso-model: a case study

2019

The present paper proposes an interphase model for the simulation of damage propagation in masonry walls in the framework of a mesoscopic approach. The model is thermodynamically consistent, with constitutive relations derived from a Helmholtz free potential energy. With respect to classic interface elements, the internal stress contribute is added to the contact stresses. It is considered that damage, in the form of loss of adhesion or cohesion, can potentially take place at each of the two blocks–mortar physical interfaces. Flow rules are obtained in the framework of the Theory of Plasticity, considering bilinear domains of ‘Coulomb with tension cut-off’ type. The model aims to be a first…