Impact of Vegetable Oil Type on the Rheological and Tribological Behavior of Montmorillonite-Based Oleogels

We formulated and characterized oleogels based on montmorillonite clay and vegetable oils that could serve as eco-friendly semi-solid lubricants. In particular, we studied the influence of the physical-chemical properties of olive, castor, soybean, linseed, and sunflower oils on the rheological, chemical, thermal, and tribological properties of the semi-solid lubricants. We prepared the oleogels via the highly intensive mixing of vegetable oils with clay at a concentration of 30 wt.%. The oleogels exhibited shear-thinning, thixotropy, structural recovery, and gel-like behavior commonly related to that of a three-dimensional network. The results were corroborated via XRD measurements showing the presence of intercalated nanoclay structures well-dispersed in the vegetable oil. Empirical correlations between the content of saturated (SFAs), unsaturated (UFAs), mono-unsaturated (MUFAs) and poly-unsaturated (PUFAs) fatty acids and the plateau modulus of the aerogels were found. From these experimental results, we can conclude that the fatty acid profile of the vegetable oils exerts an important influence on the rheological and tribological properties of resulting clay and vegetable oil oleogelsThis research was supported by FEDER European Programme and Junta de Andalucía, grant number PY20_00751. The authors acknowledge the X-ray Diffraction Service (Universidad de Huelva) for providing full access and assistance in X-ray Diffraction measurement

Conflicto y convivencia: profesores y alumnos en el proceso de enseñanza en un aula de secundaria

Esta investigación analiza las relaciones complejas entre un profesor de educación secundaria y sus alumnos en la clase de Ciencias sociales. Se examinan las posibilidades de una práctica docente más reflexiva como estrategia de superación del enfrentamiento entre la cultura de los estudiantes y la cultura escolar, representada por el profesor. A través de la experimentación de un proyecto curricular sobre el conflicto y la convivencia y utilizando una metodología cualitativa, se obtuvieron evidencias en relación con el progreso del desarrollo profesional del docente en tres dimensiones: la concepción de los contenidos escolares, la utilización de una metodología didáctica activa y la reformulación de la identidad profesional en función de un nuevo tipo de relaciones en el aula.This research analyzes the complex relations between a secondary school teacher and his students in a social science class. An examination is made of a more reflective teaching practice as a strategy to overcome confrontation between student culture and school culture, which is represented by the teacher. By experimenting with a curriculum project on conflict and interaction and using qualitative methodology, evidence was obtained in relation to the progress of teachers’ professional development in three dimensions: the conception of scholastic content, the use of active teaching methodology, and the reformulation of professional identity as a function of a new type of relationships in the classroo

Ciudadanía e identidad en el territorio. Una experiencia educativa en un barrio de Sevilla

Se expone un proceso de experimentación curricular en la enseñanza de las Ciencias Sociales con alumnado de 4º curso de la Educación Secundaria Obligatoria (16 años de edad) en un centro educativo de un barrio (Torreblanca) del extrarradio de Sevilla. Esta propuesta educativa trabaja sobre la historia de dicho barrio, formado por los familiares y descendientes de los presos políticos del franquismo condenados a trabajos forzados en la construcción del Canal del Bajo Guadalquivir. Con este trabajo se pretende recuperar la memoria histórica y contribuir a la construcción de una identidad positiva de barrio, que sirva de soporte para promover una ciudadanía emancipada y socialmente comprometida, frente a la idea de identidad dependiente, que daría lugar a una ciudadanía asistida. La experimentación se incluye en un proyecto de enseñanza de las Ciencias Sociales estructurado en torno a problemas sociales relevantes, tratados en distintas escalas y con diferentes niveles de profundidad. De esta forma, el conocimiento de la problemática del espacio vivido y la sensibilización y compromiso con los problemas próximos constituirían un punto de partida para abordar problemas sociales más globales y complejos.We describe a process of curricular experimentation in the teaching of the Social Sciences with 4th year students of Secondary Education (16 years old) in a school in a neighborhood (Torreblanca) on the outskirts of Seville. This educational proposal works on the history of this district, consisting of families and descendants of Franco's political prisoners sentenced to hard labor in the construction of the Lower Guadalquivir Canal. This work seeks to recover the historical memory and contribute to building a local positive identity that serves as support to promote an emancipated and socially committed citizenship, facing to the idea of dependent identity, which would lead to an assisted citizenship. Experimentation is included in a project of Social Sciences teaching structured around relevant social problems, treated at different scales and with different levels of depth. Thus the knowledge of the problems of living space and awareness and commitment with proximity problems would constitute a starting point to address more global and complex social problems

Convivencia y disciplina en el espacio escolar : discursos y realidades

Los problemas de convivencia en los centros escolares suelen ser tratados como problemas de disciplina escolar, mediante el control de los comportamientos del alumnado. En ese sentido, se ha elaborado una gran cantidad de normas reguladoras y de proyectos para fomentar el ambiente de convivencia en los centros, pero los resultados educativos han sido escasos. Por otra parte, la educación para la paz y para la convivencia ha sido considerada también como un tema transversal que debía ser incorporado al currículum escolar, pero la estructura del currículum escolar, organizado en materias escolares tradicionales, ha dificultado dicha intención. En esta investigación presentamos como alternativa el tratamiento de la convivencia como contenido escolar en la enseñanza de las Ciencias Sociales, en una experimentación curricular llevada a cabo con alumnado de 4º curso de Educación Secundaria Obligatoria en un centro de Sevilla.Living together problems at schools are often treated as discipline problems, just by controlling the behavior of students. In that sense, a lot of regulatory rules and projects to promote the atmosphere of living together at schools have been drawn, but the educational results have been poor. Moreover, education for peace and for living together has also been considered as a crosscutting subject that should be incorporated into the school curriculum, but the structure of the school curriculum, organized in traditional school subjects, has hindered this intention. This research presents an alternative treatment of living together at school as a teaching content of Social Sciences with students of 4th year Secondary School at a school center in Seville

Eficacia del gasto en algunas políticas activas en el mercado laboral español

A partir de la cumbre de Luxemburgo, en noviembre de 1997, las políticas activas en el mercado de trabajo recibieron un notable impulso en la Unión Europea (UE). Los acuerdos adoptados supusieron la puesta en marcha del llamado ?proceso de Luxemburgo?, dirigido a coordinar políticas de empleo para resolver los problemas estructurales del mercado de trabajo en la UE. Dichas políticas se asientan en cuatro pilares básicos: la mejora en el acceso al mercado laboral, el estímulo del espíritu empresarial, el aumento de la capacidad de adaptación de empresas y trabajadores y el fomento de la igualdad de oportunidades. A pesar de las buenas intenciones, los cambios introducidos desde 1997 no han alterado significativamente el funcionamiento del mercado laboral. En lo que se refiere al acceso al mercado de trabajo, se ha recurrido esencialmente a programas de formación para los grupos de población con mayores dificultades, como son los jóvenes, trabajadores con escasa preparación y parados de larga duración. Las directrices europeas han planteado únicamente objetivos de carácter cuantitativo centrándose en la reactivación de políticas activas preexistentes, cuya eficacia frente al problema del paro es más que dudosa. Por otra parte, existe una gran heterogeneidad entre los países miembros de la UE, tanto en lo que respecta al funcionamiento de su mercado de trabajo como a las respuestas adoptadas por parte de sus gobiernos frente al paro. Así, mientras el impulso del ?proceso de Luxemburgo? ha sido aprovechado por algunos países para evaluar concienzudamente la efectividad de sus políticas de empleo, otros se han limitado a adecuar mecánicamente sus planteamientos a las nuevas directrices europeas. En el caso de España, el plan propuesto por el anterior Gobierno conservador parece haber optado por la segunda vía, preocupándose más por cumplir en las formas que por establecer una verdadera estrategia para el empleo a medio plazo. La mayor exposición a la competencia internacional, como resultado de la creciente globalización, intensificada por la ampliación de la UE hacia el Este, exige incrementar la eficiencia en la oferta de protección social. Ello hace imprescindible evaluar la eficacia de las diferentes políticas activas de empleo con objeto de identificar aquellas que son realmente efectivas. España se sitúa a la cola de la UE en lo que respecta al gasto per cápita en políticas de empleo. Ello es especialmente preocupante teniendo en cuenta que se trata de uno de los países con mayor tasa de paro. Si nos ceñimos al gasto en políticas activas de empleo, la situación es todavía peor. Uno de los aspectos que más llama la atención es la ausencia de una evaluación sistemática de las medidas adoptadas mediante una metodología estadística apropiada

Effects of ageing on the anterior segment of the eye structure and function

[Excerpt] The world will soon have more aged people than children and more people at extreme old age than ever before [1]. Improving quality of life as well as reducing severe disability due to age-related problems has become key for the health systems worldwide. The ageing of the world population has both structural and functional consequences for the human visual system; changes due to ageing occur in all the structures of the eye causing a variety of effects. Over the last few years, great advances in ophthalmic instrumentation allow the determination of ocular parameters to a level of detail without precedent. Such advances allowresearcherstodevelopspecificdevicesforvisualcorrection and rehabilitation and at the same time guide the clinicians in their decision making and selection of treatment options to convey with the increasing demand of highquality outcomes of the ageing population. This special issue aimed at creating a multidisciplinary forum of discussion on recent advances in the knowledge of the effects of ageing in the anterior segment of the human eye’s structure and function, and improvements on early detection, treatment, and prognosis of age-related ocular conditions of the anterior segment. As a result, a remarkable compilation of ten articles cover many of these very different aspects of ocular ageing. [...]info:eu-repo/semantics/publishedVersio

Comparison of Brans Promethee multicriteria decision method and Promethee modified by authors for the optimization of an erosion control integral plan in Chaco area in Salta province (Argentine)

Chaco area is situated in the Province of Salta at North West of Argentine. The desertification is a big problem. In order to mitigate the problem it is necessary to take into account not only pedologic criteria but the economical, environmental, cultural and sociological criteria. Six sub zones have been established following previous studies. Eight criteria and six alternatives have been introduced in the model. Following the results of the study carried out by a collaborative project between UPM and UCS financed by AECID (1) were established several initial matrix. Brans Promethee multicriteria decision method (MCDM) was applied and the authors modified that method introducing weights like in Electre metho

Sheep as an experimental model: individual housing allowing visual, auditory, olfactory and tactile contact is not an obstacle for studies involving hormonal interrelationships

Thirty-two ewes were used to determine whether individual housing, allowing contact with neighbours, induces a stress response. Ewes were housed in individual pens designed to allow the ewes to see, hear, smell and touch adjacent animals, and were distributed into four groups (n=8/group): ewes with subcutaneous implants containing melatonin and oestradiol (M+E), melatonin (M), oestradiol (E) and non-implanted control ewes (C). Heart rate, stress indicators (plasma cortisol, glucose, lactate and creatine kinase (CK) concentrations) and luteinizing hormone (LH) concentrations were measured hourly and compared with the resting values (before and after pen housing). Heart rate increased significantly during the introduction into the pen (P<0.001) in all groups, in comparison with the resting values. No significant differences between groups were observed for cortisol concentrations, with the exception of the M group, which showed the highest response (P<0.001) when ewes were introduced into the pens. Lactate, CK and glucose changes in comparison with the resting values were similar between groups. LH concentrations during pen housing decreased significantly in all groups in comparison with resting values. In conclusion, individual confinement of sheep allowing visual, auditory, olfactory and tactile contact with their neighbouring animals was not an obstacle for investigating particular hormonal interrelationships with multiple sampling procedures. However further investigations are required to determine if this conclusion applies to other hormone systems in sheep

Femto-LASIK after Deep Anterior Lamellar Keratoplasty to Correct Residual Astigmatism: A Long-Term Case Series Study

Purpose: To evaluate the long-term outcomes of femtosecond laser-assisted in situ keratomileusis (Femto-LASIK) to correct residual astigmatism after deep anterior lamellar keratoplasty (DALK). Methods: This retrospective case series study included 10 eyes that underwent Femto-LASIK after a DALK. The refractive error, uncorrected (UDVA) and corrected (CDVA) distance visual acuities, thinnest corneal thickness (TCT), and central corneal thickness (CCT) were registered. The postoperative follow-up ranged between 36 and 60 months. Results: All surgeries were uneventful, with no intra- or postoperative complications. The mean UDVA (Snellen scale) rose from 0.13 ± 0.05 to 0.47 ± 0.15 six months after Femto-LASIK (p < 0.001). All cases experienced a significant improvement in UDVA. None of the eyes lost lines of CDVA, and seven eyes (70%) improved the CDVA compared to preoperative values. The refractive cylinder changed from a preoperative value of −3.88 ± 1.00 D to −0.93 ± 0.39 six months after Femto-LASIK (p < 0.0001). In eight eyes (80%), the UDVA and refractive outcomes remained stable at postoperative follow-up visits. In contrast, one eye experienced a refractive regression over the follow-up. TCT and CCT were stable at the different postoperative follow-up visits. Conclusions: Our findings suggest that Femto-LASIK might safely and effectively corrects residual astigmatism after DALK. Despite these encouraging results, further long-term studies, including a larger number of cases, are required to confirm the safety of the procedure. The refractive stability in eyes with prior RK might be lower than for other DALK indications.Depto. de Optometría y VisiónFac. de Óptica y OptometríaTRUEpu

Educating for living in urban areas: an innovative approach for initial teacher training

Se describe una propuesta para la formación inicial de maestros centrada en la idea de ambientalización e integración del currículo. La ciudad como medio y como cultura en la que nos desenvolvemos nos ofrece múltiples oportunidades de aprendizajes funcionales. Al mismo tiempo nos permite recuperar la perspectiva de las finalidades educativas en cuanto nos pone en contacto con los problemas sociales y ambientales de nuestro mundo y con la necesidad de educar para una ciudadanía democrática y participativaIt describes a proposal for initial teacher training focused on the idea of greening and curriculum integration. The city as a medium and culture in which we live gives us multiple opportunities for learning functional. At the same time allows us to gain perspective of the educational aims as put us in contact with social and environmental problems of our world and the need to educate for democratic citizenship and participatio