Search results for " SCIENZA"

Viscoelasticity: an electrical point of view

2014

Time dependent hereditary properties of complex materials are well described by power-laws with real order exponent. This experimental observation and analogous electrical experiments, yield a description of these properties by using fractional-order operators. In this paper, elasto-viscous and visco-elastic behaviors of fractional order hereditary materials are firstly described by using fractional mathematical operators, based on recent work of some of the authors. Then, electrical analogous models are introduced. Viscoelastic models have elastic and viscous components which can be obtained by combining springs and dashpots: these models can be equivalently viewed as electrical circuits, …

Ageing of isotactic polypropylene due to morphology evolution, experimental limitations of realtime density measurements with a gradient column

2006

Abstract Ageing in crystalline polymers is responsible for the deterioration of physical properties leading, for example, to a decrease in toughness and to dimensional changes that are to some extent responsible for warpage and scrap production in injection molding. Since, it depends on the mutual transformation of stable and metastable phases, being always related to changes in morphological organization, it is here preferred to call it ‘Morphological ageing’. Although, one would expect the ageing regime to be determined by the complex morphology with amorphous phases of different mobility and eventually multiple crystalline phases, transformed into each other at an associated transition, …

Spatial fragmentation of, and US support for, the main multilateral institutions of the western order

2017

The growth of China-led minilateral initiatives mostly of a regional character has challenged the main multilateral institutions of the Western order and, ultimately, US authority. Faced with a progressive delegitimation of the institutional architecture that it promoted after World War II, the US, under the Obama administration, has acted to defend the existing main multilateral institutions of the order (UN, IMF, WB and WTO), attributing them with a strategic role. More than being radical, though, the reforms enacted have been incremental and pragmatic, but always imperfect. More importantly, they have not altered US influence, which is exercised mostly through informal means. This, howev…

XFEM approach to nonlinear analysis of composite structures

2008

Pull-off adhesion of hybrid glass-steel adhesive joints in salt fog environment

2016

The aim of this paper was to evaluate the durability behaviour of glass/steel adhesive joints exposed to salt fog environmental conditions for ten weeks, according to ASTM B117 standard. To this scope, pull-off mechanical tests were carried out in order to evaluate the performances evolution and damage phenomena of the adhesive joints during the ageing exposition. Two different types of adhesives were compared (i.e. epoxy and polyurethane ones). Moreover, the effects of the glass surface condition and the presence of a basalt mat layer within the adhesive thickness were evaluated. The mechanical performances were related with the occurred failure mechanisms. Epoxy-based joints showed higher…

Aid for trade policy in developing and least developed countries: A GTAP simulation analysis

2011

Recent global initiatives on debt relief and development assistance call for increasing aid for trade to the poorest countries. We apply a multi-country computable general equilibrium model, to analyze if aid for trade offers the possibility that, instead of the developing and least developed countries’ being worse off—as so many were as the result of the last round of trade negotiations—they will actually be better off. Alternative aid for trade scenarios have been evaluated in terms of effectiveness and equity. Our findings show that aid for trade policies expand trade and alleviate inequalities. The developing and least developed countries will benefit mainly from aid for trade assistanc…

Alcune considerazioni sulla tecnica di rinforzo con angolari e piatti metallici di elementi compressi in calcestruzzo

2008

Filosofi e animali in Roma antica. Modelli di animalità e umanità in Lucrezio e Seneca

2009

Filosofi e animali in Roma antica. Modelli di animalità e umanità in Lucrezio e Seneca

2012

Nel dibattito della nostra epoca la presenza degli animali, e l'insieme dei problemi connessi alla relazione uomo-animale, sembrano sempre più acquisire un ruolo di primo piano. Ciò vale in egual misura per le scienze naturali e le discipline umanistiche, per la biologia evolutiva come per la filosofia morale. Soprattutto, appare sempre più consistente il peso degli interrogativi etici - bioetici - impliciti nelle questioni zooantropologiche. Questo volume intende riprendere in considerazione l'opera di due fra i più importanti pensatori della cultura romana, l'epicureo Lucrezio e lo stoico Seneca, al fine di ripercorrere attraverso sondaggi selettivi l'ampio dibattito sviluppatosi a Roma, …

Antimicrobial and antioxidant supramolecular ionic liquid gels from biopolymer mixtures

2023

In this work, we describe the preparation and characterization of supramolecular ionic liquid gels based on binary mixtures of biopolymers, comprising chitosan, chitin, cellulose and lignin. The gels were obtained in ionic liquids differing in the cation or the anion, with no need for a cross-linking agent or acid treatment. The materials obtained were characterized for the minimum gelation concentration, porosity, swelling and rheological properties, finding a prominent influence of the nature of the ionic liquid anion. Then, we investigated the ability of the gels to scavenge free radicals, finding that the gels exhibit a higher antioxidant ability than their individual components. Moreov…