325,135 research outputs found
Presentazione di Migrazioni al femminile
No full textLa previsione sull'andamento nei prossimi anni delle migrazioni verso l'Italia ci dicono che le caratteristiche principali dei migranti saranno la giovane età e la prevalenza della componente femminile. Spesso le storie personali delle protagoniste femminili delle migrazioni sono state occultate in una sostanziale invisibilità. Il numero monografico della rivista muove dall'intento di dar voce a queste protagoniste, di promuovere una più corretta e aggiornata conoscenza del fenomeno della migrazione femminile, dei risvolti economici dell'attività delle donne, dell'incontro scontro tra patrimoni culturali diversi di cui le donne sono portavoci e attive trasformatrici
A non-invasive capacitive sensor strip for aerodynamic pressure measurement
No full textThis paper presents a capacitive pressure sensor strip implemented in general purpose printed circuit board (PCB) technology based on a thin 3D structure composed of polyimide, woven glass reinforced epoxy resin (FR4) and metal layers. Multiphysics finite elements method (FEM) simulations have been performed over the proposed structure in order to develop a time-dependent electrical and mechanical model that can be easily used to tailor the characteristics to the application. The device targets a wide class of fluid dynamics applications, being non-invasive, comformable and smart for placement. The device simulations are herein validated by experimental wind tunnel measurements and compared with figures obtained on a wing profile by conventional electromechanical pressure transducers. This approach is one of the first example of fully embedding and electronically controlled fluid flow monitoring apparatus that could be used in replacement of state of the art mechanical systems
Creep modelling of 316H stainless steel over a wide range of stress
No full textInvestigation of material creep behaviour in the diffusion controlled creep regime is often unfeasible because of the long duration associated with low stress levels. On the other side, extrapolation from higher creep rates usually provides inaccurate results because of the sharp change in the data trend as a result of the change in the governing deformation mechanism from dislocation to diffusion type controlled creep. Similarly, extrapolation based on creep models, which have been formulated and validated mainly for dislocation type creep (such power law creep with the creep exponent ranging from 6 to 9), underestimates the actual creep rate significantly. Recently, Bonora and Esposito (2010) developed a mechanism-based model (BE model) capable to account for deformation and damage mechanism occurring in creep. In this work the BE model was applied to AISI 316H stainless steel for which considerable creep data in both dislocation and diffusion temperature/stress controlled regime were available. Using the same data set, the predictive capabilities of several models were compared
Modeling of multiaxial stress effects on the creep resistance of high chromium steel
No full textMaterials creep resistance is usually determined under uniaxial constant load condition while the state of stress in real components is multiaxial in general. How to correlate multiaxial creep behavior to uniaxial creep data is still an open issue. Most of the theories available in the literature are phenomenological in nature and limited to few classes of metals and stress triaxiality ranges. From the computational point of view, stress field relaxation depends on the creep model formulation. Therefore, it is necessary to use a refined creep model capable to reproduce the effective state of stress in the material. In the present work, a mechanism based creep model proposed by Bonora and Esposito [1] was used to predict creep life of P91 high chromium steel under multiaxial state of stress. This creep model is capable to reproduce all creep stages and was validated for different classes of metals and alloys. The performance of different reference stress definitions (i.e. the principal facet stress, skeletal stress and a new formulation) was investigated. Results were compared with available creep life data obtained on round notched samples at different temperatures
Europe and the Roman Curia: Conflicts of the Counter Reformation
No full textThe Roman Curia will be analyzed as an international agency capable of acting not so much as the head of a powerful machine, but as the place of confluence, listening and governing of local conflicts coming from the European multi-denominational space, and above all of managing structural conflicts within the Catholic Church.
The essay considers the period between the Peace of Augsburg in 1555 and the end of the Thirty Years' War (1648), with particular attention to the institutional diplomatic channels (nuncios and apostolic legates) and the international activity of the regular orders before and after the creation (1622) of the cardinal Congregation of Propaganda Fide
It’s all about the surface! Vibrational spectroscopy applied to the study of biomimetic surfaces in Tissue Engineering
No full textTissue Engineering is a multidisciplinary field aimed at the creation of biological substitutes that restore and maintain the biological function of a damaged tissue. The key of the success of these biomedical devices lies into surface interactions with living tissues, therefore a common strategy is to create biomimetic surfaces that helps cells to colonize the biomaterial, leading to tissue healing.
Vibrational spectroscopy, in particular Raman, apart from being mainly surface and non-destructive technique, is extremely sensitive to changes in structure and molecular interactions, thus its use in investigating biomimetic devices is increasing.
In particular, we have recently used vibrational spectroscopies to investigate different biomimetic materials and to test some of their proprieties:
- self-assembling peptides adsorbed on titanium surfaces for bone implants [1], analyzed before and after attack from free radicals (obtained by gamma-radiolysis and mimicking inflammation processes) [2], with the aim to evaluate their capability in resisting to oxidative stress;
- composite (ceramic-polymer, polymer-polymer) bioresorbable biomaterials [3, 4];
- hydroxyapatite nanomaterials functionalized with proteins to increase biocompatibility [5-7].
[1] M. Di Foggia, P. Taddei, A. Torreggiani, M. Dettin, A. Tinti, J. Raman Spectrosc. 42 (2011) 276-285.
[2] M. Di Foggia, A. Torreggiani, P. Taddei, M. Dettin, A. Tinti, J. Raman Spectrosc. 44 (2013) 1446-1450.
[3] V. Guarino, F. Causa, P. Taddei, M. Di Foggia, G. Ciapetti, D. Martini, C. Fagnano, N. Baldini, L. Ambrosio, Biomaterials 29 (2008) 3662-3670.
[4] V. Guarino, P. Taddei, M. Di Foggia, C. Fagnano, G. Ciapetti, L. Ambrosio, Tissue Eng. A 15 (2009) 3655-3668.
[5] M. Iafisco, B. Palazzo, G. Falini, M. Di Foggia, S. Bonora, S. Nicolis, L. Casella, N. Roveri, Langmuir 24 (2008) 4924-4930.
[6] M. Iafisco, M. Di Foggia, S. Bonora, M. Prat, N. Roveri, Dalton Trans. 40 (2011) 820-827.
[7] M. Iafisco, E. Varoni, M. Di Foggia, S. Pietronave, M. Fini, N. Roveri, L. Rimondini, M. Prat, Colloids Surf.s B 90 (2012) 1-7
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