298 research outputs found
Effects of plasticization of a soft silicone for dielectric elastomer actuation
No full textGalantini, Fabia, Federico Carpi, and Giuseppe Gallone. "Effects of plasticization of a soft silicone for dielectric elastomer actuation." Smart Materials and Structures 22.10 (2013): 104020.The final publication is available at IOP via http://dx.doi.org/10.1088/0964-1726/22/10/10402
Erratum: Lack of immunity against rubella among Italian young adults. [BMC Infect Dis., 17, (2017) (199)] Doi: 10.1186/s12879-017-2295-y
No full textAfter publication of this article [1], the authors noted that the given names and family names of all authors had been inverted, and are therefore incorrect in the original article. In the original article, the author names appear as the following: Gallone Maria Serena, Gallone Maria Filomena, Larocca Angela Maria Vittoria, Germinario Cinzia and Tafuri Silvio. However, this is incorrect, and the author names should appear as per the below: Maria Serena Gallone, Maria Filomena Gallone, Angela Maria Vittoria Larocca, Cinzia Germinario, Silvio Tafuri. The author names have been corrected in the author list and the citation for this Erratum
Il PRIMOATTORE. Giuseppe Ciro Galvani. Una vita tra arte, teatro e cinema
No full textCiro Galvani (Giuseppe Ciro Galvani, Castle San Pietro Terme 10 aprile 1867- 28 gennaio 1956)
Diplomatosi alla Regia Accademia di Belle Arti di Bologna, iniziò giovanissimo a collaborare con le più importanti riviste illustrate italiane e straniere in qualità di disegnatore e caricaturista. Contemporaneamente intraprese la carriera di attore drammatico. Recitò nelle compagnie di Emanuel Zacconi e di Eleonora Dusa. La sua collaborazione e la devozione alla Duse, al centro della sua vita artistica, lo portano a recitare nei più importanti teatri di tutto il mondo. Fanno parte della storia del teatro le sue interpretazioni nei drammi dannunziani Francesca da Rimini (1901, Ostasio), Più che l’amore (1906, Virginio Vesta), La Nave (1908, Vescovo Sergio), Fedra (1909 Messo e Aedo). Durante il primo conflitto mondiale organizza spettacoli per i soldati al fronte e gli invalidi negli ospedali, mentre all’estero tenne varie conferenze di propaganda in favore del Prestito Nazionale. Parallelamente iniziò anche l'attività cinematografica interpretando oltre una ventina di film tra il 1909 e il 1937; tra questi si ricordano "Salomé" di Ugo Falena (1090), "Kean. Genio e sregolatezza di Armando Brunero (1916), "Nemsis" di Carmine Gallone (1920), "La Nave" di Gabriellino d'Annunzio (1921, insieme a Ida Rubinstein), "La mirabile visione" di Luigi Caramba (1921) e Scipione l'Africano ancora di Carmine Gallone (1937)
Handheld-Impedance-Measurement System with seven-decade capability and potentiostatic function
No full textThis paper describes design and test of a new impedance-measurement system for nonlinear devices that exhibits a seven-decade range and works down to a frequency of 0.01 Hz. The system is specifically designed for electrochemical measurements, but the proposed architecture can be employed in many other fields where flexible signal generation and analysis are required. The system employs an unconventional signal generator based on two pulsewidth modulation (PWM) oscillators and an autocalibration system that allows uncertainties of less than 3% to be obtained over a range of 1 kΩ to 100 GΩ. A synchronous demodulation processing allows the noise superimposed to the low-amplitude input signals to be made negligibl
Functionalised carbon nanotubes loaded polyurethane dielectric elastomer for transduction.
No full textDielectric elastomers, thanks to their particular dielectric and mechanical properties, have recently been the focus of several works regarding electromechanical transduction. Silicones, polyurethanes and acrylic elastomers are, in fact, the main representatives of electronic polymers for transduction among the broad class of electro-active polymers. In order to be employed as materials for actuation, however, they have to show high dielectric constant, low elastic modulus and, possibly, restrained dielectric and mechanical losses, so to maintain high dielectric strengths and allow large deformations.
In this work, for the first time, a study on the effects of loading of an elastomeric polyurethane with covalent functionalized carbon nanotubes (FCNTs), is presented. The obtained composites have been dielectrically, mechanically and electromechanically characterized and the properties observed have been compared with those showed by composites containing the same fractions of pristine carbon nanotubes as filler. The values of actuation strains showed by some of the prepared systems drive to the conclusion that an effective increase in the electromechanical performance is possible by using FCNTs as filler and open the way for future investigations
Effects of Corona Treatment on Electrical and Mechanical Properties of a Porous Dielectric Elastomer
No full textThe main problem of dielectric elastomer (DE) actuators is today represented by the high driving electric fields (orders of 10-100 V/μm) necessary for their activation. Although several attempts have been made in order to increase strains by enhancing the dielectric constant (ε') of such matrices and keeping low elastic moduli (Y) to control the ε/Y ratio, currently several challenges have still to be faced. In this work, a new approach is presented to enhance the electrical properties of DE elastomers. Soft elastomeric polyurethane (PU) matrices with foam structure were electrically modified via Corona process. Such matrices showed electret-like properties, possibly due to the presence of macro-dipoles established both at the matrix/pore surfaces and inside the bulk. Morphological (SEM, Bet), dielectric and dynamic-mechanical (DMA) analyses were performed in order to characterize the material. Results showed that Corona charging may represent a new promising route to obtain dielectric elastomers with improved dielectric properties, although ways to promote charge trapping and retention are still do be found
Microwave induced devulcanization for poly(ethylene–propylene–diene) recycling
No full textThe production of high quantities of end-of-life rubbers is an environmental problem of growing importance. Because of their crosslinked nature, such rubbers cannot be easily reprocessed, and actually, they are mainly wasted or reused after a simple mechanical grinding. In this study, a microwave (MW)-induced thermal treatment at temperatures above 300 C was proposed to obtain partial devulcanization of a poly(ethylene–propylene–diene) (EPDM) rubber filled with carbon black. The use of MWs showed to be a very fast and simple technique, which allowed the production of a treated rubber with a relatively low degree of crosslinking, a slight revulcanization ability, and suitability for reuse in conjunction with virgin rubber. Preliminary mechanical characterization, performed on the revulcanized samples, indicated that the virgin and treated rubber were able to establish a good interface adhesion, which led to performances better than those of similar materials where the recycled part was made of ground untreated EPDM
Soil Remediation by Petroleum Products: Modeling and Experimental Investigation of Microwave Treatment
No full textThe microwave-generated steam treatment of contaminated soil is based on incrementing the temperature by microwave energy irradiation in the presence of a sufficient moisture amount. Therefore the previous knowledge of the temperature distribution in the irradiated soil is essential for the correct application of the treatment. In this work a mathematical model was developed to describe the heat and the mass transfer evolution in a soil-water system during the microwave remediation. The time-dependent model was based on mass and energy conservation equations and had the purpose to outline the temperature and humidity variations during the time and along the soil sample depth. As a preliminary drafting of the model the following assumptions were made: 1) no reactions in the soil, 2) no radial moisture and temperature gradients. A key role is played by the overall dielectric properties which drive the absorption of energy by the soil and, at the same time, are subjected to change with moisture content and temperature. Microwave heating was performed on
laboratory-scale experiments, measurement of temperature and residual moisture amount were carried out during the time and along the sample depth. The agreement between the experimental values and the numerical results was appreciable both for the temperature and the moisture amount. Further tests with linear hydrocarbons (noctane, n-decane, n-dodecane, etc...), mixture of them and kerosene confirmed the necessity of an optimum moisture content in the soil in order to achieve a costeffective use of microwaves for soil decontamination
Improving performance of electro-active polymers (EAPs) via Corona Charging
No full textThe main problem of dielectric elastomer (DE) actuators is today represented by the high driving electric fields (orders of 10‐100 V/μm) necessary for their activation. Although several attempts have been made in order to increase strains by enhancing the dielectric constant (ε) of such matrices and keeping low elastic moduli (Y) to control the ε/Y ratio, currently several challenges have still to be faced. In this work, a new approach is presented to enhance the electromechanical performance of DE actuators. Soft elastomeric polyurethane (PU) matrices with foam structure were electrically charged and poled via Corona process. Such matrices showed electret‐like properties, possibly due to the presence of macro‐dipoles induced both at the matrix/pore surfaces and inside the bulk. Morphological (SEM, Bet), dielectric and dynamic‐mechanical (DMA) tests were performed in order to characterize the material. Results showed that corona charging may represent a new promising route to obtain dielectric elastomers with improved dielectric properties
Perspectives for new dielectric elastomers with improved electromechanical actuation performance: composites versus blends
No full textThis work presents a comparison between composites and blends as two alternative approaches for the development of new dielectric elastomers offering superior electromechanical properties at lower driving electric fields. Silicone- and polyurethane- based dielectric elastomers were modified by either making particulate composites with high-permittivity ceramic fillers or by blending with different polymeric phases. Both previous and new data are considered. Experimental observations are compared and discussed to assess which one of the aforementioned approaches might be more generally preferable. Due to a consequent worsening of the mechanical properties, pure composite architectures yielded only limited results. While with the blend approach both an increase of the dielectric permittivity and an unexpected reduction of the tensile elastic modulus were observed, leading to an overall increase of the electromechanical response. The blending approach permits one to obtain a new dielectric elastomer with improved electromechanical properties by simply combining two low-dielectric-constant polymers. This is the first time such a type of result has been reported. This study indicates that formulating all-polymeric compounds may represent a very promising route for obtaining new dielectric elastomers with improved actuation performance
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