Search results for " Materiale"
showing 10 items of 139 documents
Effect of the dissolution time into an acid hydrolytic solvent to tailor electrospun nanofibrous polycaprolactone scaffolds
2017
[EN] The hydrolysis of the polycaprolactone (PCL) as a function of the dissolution time in a formic/acetic acid mixture was considered as a method for tailoring the morphology of nanofibrous PCL scaffolds. Hence the aim of this research was to establish a correlation between the dissolution time of the polymer in the acid solvent with the physicochemical properties of the electrospun nanofibrous scaffolds and their further service life behaviour. The physico-chemical properties of the scaffolds were assessed in terms of fibre morphology molar mass and thermal behaviour. A reduction of the molar mass and the lamellar thickness as well as an increase of the crystallinity degree were observed …
Influence of substrate and temperature on the biodegradation of polyester-based materials: Polylactide and poly(3-hydroxybutyrate-co-3-hydroxyhexanoa…
2020
[EN] The extended use of polymers from renewable resources such as aliphatic polyesters or polyhydroxyalkanoates boosted the necessity to understand their behaviour in an end-of-life scenario. Although they can be degraded in reasonable shorter times than traditional polymers, understanding the degradation mechanisms under dissimilar conditions will contribute to further developments in this field. This work aimed to study the effect of temperature and substrate in the degradation of polylactide (PLA) and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH) in a simulated laboratory scale to ascertain their contribution, separately or in combination. For this purpose, nine parallel degradat…
First-order and tricritical wetting transitions in the two-dimensional Ising model caused by interfacial pinning at a defect line
2014
We present a study of the critical behavior of the Blume-Capel model with three spin states (S=±1,0) confined between parallel walls separated by a distance L where competitive surface magnetic fields act. By properly choosing the crystal field (D), which regulates the density of nonmagnetic species (S=0), such that those impurities are excluded from the bulk (where D=) except in the middle of the sample [where DM(L/2)≠], we are able to control the presence of a defect line in the middle of the sample and study its influence on the interface between domains of different spin orientations. So essentially we study an Ising model with a defect line but, unlike previous work where defect lines …
Bild unserer irren Anwesenheit/auf der Oberfläche der Erde. L’immagine come storia naturale del presente nella poetica diW. G. Sebald
2017
The poem Nach der Natur by W. G. Sebald, real germinal place of its author’s subsequent literary production, is a salient moment of confrontation for today's philosophical gaze; our historical time and our own humanity are configured as “natural history” (Benjamin), in a compositional game in which the present time acquires the character of a timeless distance projecting it on the background of a mournful nature, entrusting to the roughness of the poetic material and to its conceptual weaving the task of an unprecedented presentification of some layers of reality of rare density.
Force-free state in a superconducting single crystal and angle-dependent vortex helical instability
2017
Superconducting 2H-NbSe2 single crystals show intrinsic low pinning values. Therefore, they are ideal materials with which to explore fundamental properties of vortices. (V, I) characteristics are the experimental data we have used to investigate the dissipation mechanisms in a rectangular shape 2H-NbSe2 single crystal. Particularly, we have studied dissipation behavior with magnetic fields applied in the plane of the crystal and parallel to the injected currents, i.e. in the force-free state where the vortex helical instability governs the vortex dynamics. In this regime, the data follow the elliptic critical state model and the voltage dissipation shows an exponential dependence.Moreover,…
Droplets pinned at chemically inhomogenous substrates: A simulation study of the two-dimensional Ising case
2016
As a simplified model of a liquid nanostripe adsorbed on a chemically structured substrate surface, a two-dimensional Ising system with two boundaries at which surface fields act is studied. At the upper boundary, the surface field is uniformly negative, while at the lower boundary (a distance L apart), the surface field is negative only outside a range of extension b, where a positive surface stabilizes a droplet of the phase with positive magnetization for temperatures T exceeding the critical temperature Tw of the wetting transition of this model. We investigate the local order parameter profiles across the droplet, both in the directions parallel and perpendicular to the substrate, vary…
Characterization of V-doped SnO2 nanoparticles at ambient and high pressures
2018
Nanoparticles of V-doped SnO2 with stoichiometry Sn1-xO2Vx (x = 0.05, 0.075, 0.125) have been synthesized by a co-precipitation method. Their structural, vibrational, and nuclear properties have been characterized by x-ray Diffraction, Transmission Electron Microscopy, Energy Dispersive x-ray Spectroscopy, Raman Spectroscopy, and Mössbauer Spectroscopy (with 119Sn probe) at ambient pressure. We also performed high-pressure synchrotron x-ray diffraction experiments. The structural behaviour was studied up to ∼10 GPa under quasi-hydrostatic conditions. It has been found that tin dioxide nanoparticles with V are more compressible than un-doped tin dioxide nanoparticles. Fil: Ferrari, S. Consej…
Il Patrimonio della città sostenibile nel Mediterraneo. Progetti sostenibili per il centro storico di Tunisi
2013
Questo contributo si concentra sull’analisi di nuove strategie di rigenerazione urbana che hanno come obiettivo primario la valorizzazione del Patrimonio della città sostenibile nel Mediterraneo. La nostra ipotesi vuole dimostrare che il Patrimonio è diventato il vettore mobilizzatore del cambiamento delle città mediterranee, coinvolgendo mestieri, abitanti e fruitori. Verranno esaminati due progetti realizzati nella città di Tunisi dall’Association de Sauvegarde de la Médina (ASM): l’intervento di valorizzazione di un percorso urbano che collega gli spazi pubblici e il patrimonio architettonico della Medina (2008), dalla Mosquée Zitouna alla Zaouina di Sidi Ibrahim Riahi; il piano di rivit…
Quantitative analysis of the obturation of oval-shaped canals using thermoplastic techniques
2023
The main aim of this study is to quantify the area filled by gutta-percha, the area filled by cement and the area of voids present in oval canals, treated by thermoplastic filling techniques in comparison with the lateral condensation technique and observe the adaptation of the gutta-percha to the anatomy of the oval root canals according to the obturation technique. 80 mandibular incisors were selected. The teeth were instrumented with Protaper Gold and divided into 4 groups of 20. Group 1 was filled with Thermafill; group 2 with GuttaCore; group 3 with continuous wave vertical condensation and group 4 with the lateral condensation technique. Two horizontal sections were cut at 5mm and 7m…
Efficacy of stem cells in bone rehabilitation in patients with alveolar bone atrophy: a systematic review
2023
Background: Biomedical engineering proposes the use of stem cells as a bone rehabilitation treatment in patients with alveolar bone defects. Many authors suggest that this innovative technique could represent the future of bone regeneration in dentistry. The present study systematically reviewed the efficacy of stem cells in bone regeneration in patients with alveolar bone atrophy. Material and methods: The study was developed following the criteria of the PRISMA guideline (2020). The literature review was conducted in Pubmed, Medline Complete, and Scopus. The search algorithms used the following key words: stem cells, bone regeneration, and alveolar ridge augmentation. To assess the risk o…