Search results for "Ultima"
showing 10 items of 396 documents
Effect of ferulic acid and α-tocopherol antioxidants on properties of sodium caseinate edible films
2011
Edible films, based on sodium caseinate containing three different concentrations of ferulic acid or alpha-tocopherol (20, 40 and 60 mg/g sodium caseinate), were obtained in order to evaluate the effect of these compounds on properties of the caseinate matrices. Special emphasis was placed on their effect on the films' oxygen barrier properties, which are decisive in the prevention of the oxidation of foods containing lipids. Films were characterized as to their tensile, optical and surface properties as well as their barrier properties to water vapor, oxygen and aroma compounds (n-hexanal and n-hexanol). Ferulic acid was more efficient at reducing oxygen and n-hexanal permeability than alp…
Halloysite nanotubes filled with MgO for paper reinforcement and deacidification
2021
Abstract A novel material for the deacidification and protection of paper has been designed by using MgO filled halloysite nanotubes (Hal). The ability of MgO loaded nanotubes to control the acidic conditions was evaluated by pH measurements in aqueous solvent. Afterwards, paper was impregnated into hydroxypropyl cellulose dispersions containing the consolidating material. A simulation of strong acidic conditions allowed us to evaluate the deacidification effect of the composite material on the samples. In particular, the paper reaches a pH of 7.7 after 1 h exposition to HNO3 vapours when MgO-Hal nanoparticles are added to the impregnation mixture at a concentration of 10 wt% and it remains…
Altered neural responses to social fairness in bipolar disorder
2020
Highlights • Bipolar disorder is characterized by impaired processing of social fairness. • BD patients exhibit increased rejection of moderate unfairness in Ultimatum Game. • BD patients display decreased response to moderate unfairness in anterior insula. • BD patients deactivate posterior and middle insula in response to unfairness. • Trait impulsivity positively correlated with deactivations in posterior insula.
Numerical modelling of the tensile behaviour of BFRCM strips
2019
This paper aims at investigating the tensile behaviour of basalt fibres on cementitious matrix for the strengthening of masonry structures. The use of Basalt Fibre Reinforced Cementitious Matrix (BFRCM) is favourably considered by the scientific community because it represents a natural composite material with high compatibility with stone and masonry substrate. The study is developed through the generation of Finite Element (FE) models capable of reproducing the tensile behaviour of BFRCM strips with different number of layers of grid. For the scope, the micro-modelling approach is adopted assuming different levels of detail for the simulation of the interface constitutive behaviour. Fibre…
Glass-basalt/epoxy hybrid composites for marine applications
2011
Abstract The aim of this work is to evaluate the influence of uniaxial basalt fabric layers on the mechanical performances of a glass mat/epoxy composite used for marine applications. Polymer composites, reinforced by glass mat (GFRP), and hybrid ones, reinforced by glass mat and unidirectional basalt fabric, have been produced by vacuum bagging technique. Three points bending and tensile tests have been carried out in order to evaluate the effect of number and position of basalt layers on the mechanical properties of the investigated structures. The experimental tests have showed that the presence of two external layers of basalt involves the highest increase in mechanical properties of hy…
PLA graphene nanoplatelets nanocomposites: Physical properties and release kinetics of an antimicrobial agent
2017
Abstract Graphene nanoplatelets (GnP) as filler and ciprofloxacin (CFX) as biocide were incorporated via melt-compounding into poly(lactic acid) (PLA) to obtain biopolymer-based nanocomposites with antimicrobial properties. GnP were added with the aim of improving the mechanical properties of the antimicrobial system and tuning the drug release. The obtained systems were mechanically characterized in tensile mode by quasi-static and dynamic mechanical tests. Furthermore, rheological measurements were performed. The morphology of the samples was analyzed through scanning electron microscopy (SEM). Moreover, a mathematical model, i.e. power law model, was used to fit the release data in order…
Interfacial shear strength of flax fibers in thermoset resins evaluated via tensile tests of UD composites
2012
Abstract A method of interfacial shear strength evaluation, based on the length distribution of fibers pulled out from the tensile fracture surface of an oriented flax-reinforced composite, is applied to composites with vinyl ester and acrylated epoxidized soy oil resin matrices. Two approaches for characterizing the strength of fibers with modified Weibull distribution, fiber fragmentation tests and fiber tension tests, are compared in the analysis of pull-out data. Interfacial shear strength is found to increase by a few percent when loading rate is increased from 1.33% to 8%/min.
Effects of halloysite content on the thermo-mechanical performances of composite bioplastics
2020
Abstract The aim of this study is the design and preparation of Mater-Bi/halloysite nanocomposite materials that could be employed as bioplastics alternative to the petroleum derived products. The biocomposite materials at variable halloysite content (from 0 to 30 wt%) were prepared by using the solvent casting method. We investigated the mechanical behaviour and the thermal properties of the prepared nanocomposites in order to estimate their suitability as biocompatible packaging materials. The thermo-mechanical characteristics were correlated to the nanocomposites' morphologies, which were studied by Scanning Electron Microscopy (SEM). As a general result, the physico-chemical performance…
Effect of Water on the Mechanical Behaviour of Extruded Flat Bread
1997
Abstract The effect of water on the mechanical properties of extruded breads was studied, at room temperature. As the moisture content was increased from 6 to 9% moisture, the resistance to fracture (compression tests) or rupture (tensile tests) was improved. Above this moisture range, plasticisation by water was the dominant phenomenon. The brittle to ductile transition was observed to occur within a moisture content range from 9 to 13·7% (w/w). The influence of water on the crispness of extruded bread, evaluated with sensory evaluation, is also described.
Simplified technique for constitutive analysis of SFRC
2014
Steel fibre reinforced concrete (SFRC) has become widespread material in areas such as underground shotcrete structures and industrial floors. However, due to the absence of material models of SFRC reliable for numerical analysis, application fields of this material are still limited. Due to interaction of concrete with fibres, a cracked section is able to carry a significant portion of tensile stresses, called the residual stresses. In present practices, residual stresses used for strength, deflection and crack width analysis are quantified by means of standard tests. However, interpretation of these test results is based on approximation using empirically deduced relationships, adequacy o…