Search results for "materiales"
showing 10 items of 204 documents
Prospección arqueológica en La Cova del Llop, Gandía (Valencia)
1976
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 …
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…
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…
Análisis de los Materiales Didácticos Digitales para la inclusión y diversidad en Educación Primaria
2021
Tomando como referencia la Declaración de Incheon para la Educación 2030 y su objetivo de una educación inclusiva, esta aportación se centra en examinar la visibilidad de la diversidad social en los recursos audiovisuales que ofrecen dos plataformas educativas: EduCaixa y Tiching. Taking as a reference the Incheon Declaration for Education 2030 and its objective of inclusive education, this contribution focuses on examining the visibility of social diversity in the audiovisual resources offered by two educational platforms: EduCaixa and Tiching. En esta presentación se analizan los productos destinados para la etapa de Educación Primaria como manera de entrar en el tema de la diversidad soc…
Controversies in the transition from paper and electronic textbooks to digital content
2018
Cabe pensar, dada la magnitud económica y cultural que representa el libro en nuestra sociedad, ya sea en soporte papel como electrónico, que los dos van a convivir largo tiempo. Los libros de texto, en consecuencia, correrán una suerte muy semejante. El cambio actual lo focalizamos en la transformación de los libros de texto en contenidos digitales con distintos formatos y vías de acceso. De este proceso estudiamos las controversias que suscitan estos cambios, en tanto que son reflejo del grado de asimilación por parte de la ciudadanía de las referidas innovaciones tecnológicas. Mediante estrategias etnográficas, nos acercamos a distintos agentes escolares para tratar de comprender inducti…
Proton Conducting Electrospun Sulfonated Polyether Ether Ketone-Graphene Oxide Composite Membranes
2017
[EN] A series of novel composite membranes, based on sulfonated poly(ether ketone) (SPEEK) with a graphene oxide (GO) layer, were prepared. One contained a GO layer sandwiched between the SPEEK-polyvinyl alcohol (PVA) matrix (SPEEK/PVA@GO), and another deposited thin layers of GO on the nanofibers of SPEEK-polyvinyl butyral (PVB), with both sandwiched in the phase matrix of SPEEK-PVA (SPEEK/PVA@GO-NF). Various nanofiber thicknesses were studied by varying the electrospinning time. The prepared composite membranes with different nanofiber thicknesses were characterized by scanning electron microscopy, water uptake, ionic exchange capacity, thermogravimetric analysis, mechanical properties an…