Search results for "materiales"
showing 10 items of 204 documents
Emotions and epistemology: a path for reconsideration in the 21st century
2017
The present paper explores the gap between sensations and emotions in the global capitalism. We held the thesis that there are diverse ways to systematise the theoretical orientations on which the studies on the body/emotion are based; a possible one, having in mind the Latin American context and without intent of exhaustiveness, is the following: a) a line of work connected to Foucault and his concepts of control, discipline, and technologies of the self; b) an approach connected to Bourdieu and his notions of habitus, body hexis, and social fields; c) a set of investigations in the field of biopolitics referring to Esposito and Agamben on the one hand, and to Negri and Hardt on the other;…
Desarrollo y caracterización de nuevos nanobiocomposites con propiedades mejoradas mediante varios métodos de procesado de interés en envasado de ali…
2015
El presente trabajo tiene como objetivo mejorar las propiedades de matrices biopoliméricas para su uso en aplicaciones de envasado de alimentos mediante el desarrollo de nanobiocompuestos utilizando diferentes metodologías de procesado o estrategias de incorporación de materiales nanoestructurados en el interior de las matrices biopoliméricas. Dos estrategias de incorporación fueron empleadas. La primera de ellas estaba basada en una pre-incorporación de los aditivos nanoestructurados, también llamados nanoaditivos, en oligómeros de ácido láctico mediante tecnologías de polimerización in situ (específicamente policondensación), dando lugar a masterbatches que, posteriormente, se mezclaban c…
Anomalous Slowdown of Polymer Detachment Dynamics on Carbon Nanotubes
2019
The "wrapping" of polymer chains on the surface of carbon nanotubes allows one to obtain multifunctional hybrid materials with unique properties for a wide range of applications in biomedicine, electronics, nanocomposites, biosensors, and solar cell technologies. We study by means of molecular dynamics simulations the force-assisted desorption kinetics of a polymer from the surface of a carbon nanotube. We find that, due to the geometric coupling between the adsorbing surface and the conformation of the macromolecule, the process of desorption slows down dramatically upon increasing the windings around the nanotube. This behavior can be rationalized in terms of an overdamped dynamics with a…
Las obras que nunca se acaban. El mantenimiento de los castillos en la Valencia Medieval: sus protagonistas y sus materiales
2003
A partir del estudio de los cuadernos de cuentas de distintas obras llevadas a cabo en los castillos valencianos a lo largo de los siglos XIV y XV, el objeto del presente artículo es analizar la organización de esas campañas de mantenimiento. De esta manera, se observa en primer lugar la mano de obra, desde los maestros al concurso de personal sin cualificar, en su mayoría jóvenes de la localidad y en algunos casos también mujeres; más tarde se estudian las áreas de abastecimiento de materiales y las estrategias para obtenerlos; y por último se hace un repaso a las obras emprendidas, que sin duda ayudará a comprender la forma y función de estas fortalezas, así como las debilidades de las té…
Gold Nanoparticle-Assisted Virus Formation by Means of the Delivery of an Oncolytic Adenovirus Genome
2020
[EN] Oncolytic adenoviruses are a therapeutic alternative to treat cancer based on their ability to replicate selectively in tumor cells. However, their use is limited mainly by the neutralizing antibody (Nab) immune response that prevents repeated dosing. An alternative to facilitate the DNA access to the tumor even in the presence of anti-viral Nabs could be gold nanoparticles able to transfer DNA molecules. However, the ability of these nanoparticles to carry large DNA molecules, such as an oncolytic adenovirus genome, has not been studied. In this work, gold nanoparticles were functionalized with different amounts of polyethylenimine to transfer in a safe and efficient manner a large on…
Estudios previos a la intervención en el patrimonio arquitectónico. El caso de la iglesia parroquial de San Pedro en la Pobla de Benifassà (Castellón)
2002
Cualquier tipo de intervención en el patrimonio arquitectónico requiere en primera instancia de un conocimiento del objeto de esta acción. Se debe abordar cuantos más aspectos y características del edificio para ajustarse correctamente con nuestra intervención a sus problemas reales. En su primera parte, el texto explica el funcionamiento general de los distintos capítulos de un estudio previo; en la segunda, se expone un caso real de estudio previo desarrollado por los autores del artículo; en la tercera parte, se da una explicación técnica sobre los análisis estratigráficos de las fábricas como una metodología para profundizar en el conocimiento de la historia de la arquitectura.
ZrTiO4 materials obtained by spark plasma reaction-sintering
2014
Zirconium titanate (ZrTiO4), have many attractive properties such as high resistivity, high dielectric constant, high permittivity at microwave frequencies and excellent temperature stability for microwave properties. Zirconium titanate dense materials are proposed for many structural applications, but fully reacted and completely dense pieces are difficult to obtain by conventional routes. In this work, fully dense zirconium titanate materials (∼98%) were obtained at lower temperatures (1300-1400 C) and short processing time by non-conventional technique; spark plasma-reaction sintering (SPRS). Homogeneous and stable starting powders mixture with the adequate composition was prepared from …
Order-Order Phase Transitions Induced by Supercritical Carbon Dioxide in Triblock Copolymer Thin Films
2019
We study the influence of supercritical carbon dioxide (scCO2) on the phase behavior of a cylinder-forming polystyrene-block-polybutadiene-b-polystyrenetriblock copolymer thin film. Solvent annealing with scCO2 can produce patterns with long-range order but these structures become unstable for thin films with small thicknesses. These results are in good agreement with self-consistent mean field calculations, which indicate that a drying transition occurs for thicknesses below the radius of gyration of the molecule.After decompression and solvent extraction, the initially swollen polymer nanostructure suffers a strong reduction in the average domain spacing, which has a deleterious effect on…
Cathodoluminescence and photoluminescence study of plastically deformed ZnTe bulk single crystals
2001
Samples of zinc telluride bulk single crystals, which were deformed in uniaxial compression, have been studied by photoluminescence (PL) and cathodoluminescence (CL). As a particular feature the deformed samples present a PL emission band peaked at 603 nm, whose intensity increases as the plastic deformation does. This band is related to the density of dislocations produced during the interaction of slip systems. This hypothesis is supported by CL images. which reveal the activation of the successive slip systems corresponding to different levels of deformation.
Photoluminescence Enhancement of CdSe Quantum Dots: A Case of Organogel–Nanoparticle Symbiosis
2012
Highly fluorescent organogels (QD-organogel), prepared by combining a pseudopeptidic macrocycle and different types of CdSe quantum dots (QDs), have been characterized using a battery of optical and microscopic techniques. The results indicate that the presence of the QDs not only does not disrupt the supramolecular organization of the internal fibrillar network of the organogel to a significant extent, but it also decreases the critical concentration of gelator needed to form stable and thermoreversible organogels. Regarding the photophysical properties of the QDs, different trends were observed depending on the presence of a ZnS inorganic shell around the CdSe core. Thus, while the core-s…