idUS. Depósito de Investigación Universidad de Sevilla
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Diego de Riaño, Diego Siloé y la arquitectura en la transición al Renacimiento
No full textEste volumen de autoría colectiva gira en torno a la producción arquitectónica de Diego de Riaño y Diego Siloé, dos grandes maestros del siglo XVI español, nacidos en el norte peninsular, cuyas obras quedaron diseminadas por los antiguos reinos de Sevilla y Granada, focos fundamentales de la transición al Renacimiento en la España del emperador Carlos V. En el contexto de la gran transformación experimentada por la arquitectura española en las primeras décadas del XVI, Riaño y Siloé encarnan dos modos muy diferentes de incorporar las novedades procedentes de Italia y de ofrecer respuestas a las nuevas circunstancias y exigencias. Además de las áreas fundamentales de influencia de estos dos maestros, se aborda también el estudio de la situación del resto de España y de las vecinas tierras de la Europa meridional, buscando otras experiencias constructivas que corrieron en paralelo, cuya actualización nos permite enriquecer el conocimiento de estos singulares procesos de transición
Particulate matter and potentially toxic element content in urban ornamental plant species to assess pollutants trapping capacity
No full textUrban environments are usually polluted by anthropogenic activities like traffic, a major source of potentially toxic elements (PTEs), and ornamental plant species may reduce contamination by trapping traffic-related air pollutants in their leaves. The purpose of this study was tested the trapping pollutant capacity of four species commonly used in green areas of Seville city (SW Spain) to better choose species in urban green planning. Composition of particulate matter (PM) obtained from foliar surfaces (sPM) and wax-included (wPM) was determined by EDX-SEM analysis in samples from different city locations. Concentration of different PTEs (Ba, Cd, Cr, Cu, Fe, Mn, Ni, Pb, V and Zn), by microwave induced-plasma optical emission spectroscopy (MP-AES) were also analyzed in unwashed leaves of one of the selected species (Citrus aurantium) since it is the most cultivated species in Seville. Results showed that Nerium oleander was the plant species which trapped best superficial total and coarse PM. This capacity was enhanced by the presence of a waxy-cuticle and by cuticle thickness but not by leaf hairs. The only species unable to trap fine particles was Bougainvillea glabra. The most representative sPM on leaf surfaces from all species was the largest fraction (59–75%), followed by coarse (25–37%) and fine fractions (2.2–4.4%). In the wax PM, 48% of coarse particles were found in Citrus aurantium. Particulate matter deposited on surface foliage in general did not vary seasonally, while the large fraction of wPM in summer was significantly higher than in winter. The seasonal differences also existed in the level of PTE (Cd, Fe, Ni and V) in leaves. This work indicates that the leaf traits should be taken intoaccount to evaluate the pollutants caption capacity, especially when planning of recreational green urban areas. Particulate matter composition was different according to the pollution sources and mostly contained Al, C, Ca, Fe, K, and Mg, but potentially toxic elements such as Si, As, Cr, Cu and Zn just accounted for 0.11–1.95% of the total elemental content
Cuaderno Cátedra RTVE-US. Conversaciones con Javier Gutiérrez, Redactor de internacional TVE
No full textEste volumen continúa la serie de Cuadernos de la Cátedra RTVE-US de Contenidos Culturales y Creatividad en el Sector Audiovisual y Digital, fruto de un convenio firmado entre Radio Televisión Española y la Universidad de Sevilla en junio de 2021. En octubre 2023 la Cátedra puso en funcionamiento un Seminario Permanente en el que profesores de distintas áreas de conocimiento conversan con profesionales del ente público para acercar su trabajo a los estudiantes de los títulos de Comunicación. En esta ocasión las encargadas de dirigir la actividad fueron las profesoras Carmen Espejo y María Lamuedra en el marco de un proyecto de innovación docente coordinado por Raquel Almodóvar; ambas conversaron con Javier Gutiérrez, redactor de internacional de TVE, con una amplia experiencia como corresponsal en diversos países, entre ellos Israel. El objetivo final de estos encuentros es lograr despertar el espíritu crítico de los alumnos y aproximarlos al contexto profesional al que se van a enfrentar a partir de temas de actualidad
Ciberactivismo y democracia en España. Un campo de mediación social emergente
No full textEl presente capítulo es fruto del trabajo realizado en torno a los proyectos “Ciberactivismo, Ciudadanía Digital y Nuevos Movimientos Urbanos” (CSO2016-78386-P, Programa Estatal de Fomento de la Investigación Científica y Técnica de Excelencia) y al Programa de Contratación de Personal Investigador Doctor (PAIDI 2020, Junta de Andalucía-FSE)
Assessment of mechanical variables best describing bone remodelling responses based on their correlation with bone density
No full textDensity distribution in bones can be estimated using bone remodelling models (BRM) and applying daily normal loads to assess the stress/strain state to which the bone is subjected. These models locally relate a certain mechanical stimulus, derived from the stress/strain state, directly to bone density or to its variation over time. The background of this idea is Frost’s Mechanostat Theory, which states that overloading states tend to increase bone density and disuse states tend to decrease it. Different variables have been proposed in the literature to measure the mechanical stimulus. Strain energy density (SED) and stresses have been commonly used as mechanical stimuli, but to date their use has not been justified with convincing arguments. In this paper we have selected several variables derived from stress and strain tensors and correlated them with the distribution of bone density in the femur of 13 elderly women to conclude which would be most appropriate for use as a mechanical stimulus in a BRM. We have performed this correlation analysis for six different activities: walking normally, fast walking, stair ascent, stair descent, rising from and sitting on a chair, and jumping in place. Musculoskeletal models were used to estimate joint reaction and muscle forces of each individual for each activity. These were applied to the corresponding finite element model of the femur to obtain stress and strain tensors at each point. The variables proposed as mechanical stimulus and derived from these tensors were correlated to the actual density obtained for each individual from CT-scans. Our results show that stress variables are the best correlated with density. In contrast, the correlations of SED are very weak, so it is not a good candidate for mechanical stimulus. Strains are also weakly correlated to density, but in this case because their distribution across the femur is rather uniform. This is in agreement with the Mechanostat Theory which states that bone reacts to load changes by changing its stiffness so to keep strains in a certain interval. Consequently, a plausible choice for a remodelling criterion could be keeping that strain uniformity
Novel test designs for assessing the shear fracture forming limit in thin-walled tubes
No full textThin-walled tubes are used for the manufacturing of essential components in several industries. Indeed, the characterization of their formability and failure is vital for tool design, product quality and safety. In the recent years, the number of procedures and test designs for characterizing tubes in forming has experienced a significant development. This progress has been achieved in combination with the use of digital image correlation techniques and finite element analysis, making use of different plastic anisotropy criteria. Nevertheless, most of those tests are aimed at the assessment of failure in mode I of fracture mechanics, being the analysis of fracture under in-plane shear, i.e. mode II of fracture mechanics, reduced to a very limited number of research works based in the adaptation of the corresponding sheet metal forming tests inducing shear. To this regard, this work presents two new procedures based on the specific thin-walled tube geometry for characterizing formability in-plane shear and failure in mode II of fracture mechanics, addressing the absence of specific experimental methods for evaluating the shear fracture forming limit (SFFL) for tubes. The results, based on a combined numerical modelling and experimental analysis of the proposed tests, show that the SFFL can be accurately evaluated by controlling a set of geometrical parameters in the specimens designed to generate shear in tubes by applying either tensile or compressive forces. These proposed tests provide a valuable tool for characterizing the SFFL of thin-walled tubes
Right of withdrawal in contracting with consumer and users
No full textLa extinción de las obligaciones por la mera voluntad sin causa es un remedio excepcional,
habilitándose en la contratación con consumidores como medida de contrapeso ante la desigualdad
existente entre las partes, si bien no es otorgada a todos ellos, al requerirse su reconocimiento normativo o
voluntario, pretendiéndose efectuar una visión general de esta figura, para lo cual se valorarán las
exigencias, tanto de la normativa general como de las particulares existentes para contratos específicos y
que inciden en la forma para su ejercicio, el plazo, el momento de eficacia y sus consecuencias.The extinguishment of obligations by mere Will without cause is an exceptional remedy, enabling
contracting with consumers as a counterweight measure to the existing inequality between the parties, as
this requires prior regularity recognition or its granting by the entrepreneur to the consumer. The aim of
this paper is to provide an general overview of the exercise of withdrawal in consumer contracts, to this
end, the general inserted in the general regulations protecting consumers and users will be assessed, as
well as the particulars existing in the regard for specific contracts both in that provision and in other special
laws and that have an impact on the manner in which it is to be excercised, the period for do it, the moment
of effectiveness and the consequences derived from it
Educators' perspective on YouTube use: an analysis of their digital competences according to the territory and educational stage
No full textThis study examines educators' self-perceived digital competences in using YouTube across urban and rural settings and educational stages. The research objectives were to: (1) assess teachers' digital competences in searching, communicating, and creating content on YouTube; (2) compare competences between urban and rural teachers; (3) analyze competences by educational stage; and (4) identify actions to improve digital skills. Using an ex post facto design, data were collected from 2,157 Spanish teachers during the 2022/2023 academic year. Results revealed a medium-high level of digital competence, with urban teachers outperforming rural counterparts. Competences increased with higher educational stages, except for rural VET. Content creation was the most challenging area for both groups. Significant correlations were found between digital competence and actions like video editing and publishing. These findings highlight the need for targeted training, particularly in rural areas, to enhance teachers' digital skills and optimize YouTube's educational potentia