Temperature dependent NIR emitting lanthanide-PMO/silica hybrid materials

Two materials - a mesoporous silica (MS) and a periodic mesoporous organosilica (PMO) functionalized with dipyridyl-pyridazine (dppz) units were grafted with near-infrared (NIR) emitting lanthanide (Nd3+, Er3+, Yb3+) complexes in an attempt to obtain hybrid NIR emitting materials. The parent materials: dppz-vSilica and dppz-ePMO were prepared by a hetero Diels-Alder reaction between 3,6-di(2-pyridyl)-1,2,4,5- tetrazine (dptz) and the double bonds of either ethenylene-bridged PMO (ePMO) or vinyl-silica (vSilica) and subsequent oxidation. The dppz-vSilica is reported here for the first time. The prepared lanthanide-PMO/silica hybrid materials were studied in depth for their luminescence properties at room temperature and chosen Nd3+ and Yb3+ samples also at low temperature (as low as 10 K). We show that both the dppz-vSilica and dppz-ePMO materials can be used as "platforms" for obtaining porous materials showing NIR luminescence. To obtain NIR emission these materials can be excited either in the UV or Vis region (into the pi -> pi* transitions of the ligands or directly into the f-f transitions of the Ln(3+) ions). More interestingly, when functionalized with Nd3+ or Yb3+ beta-diketonate complexes these materials showed interesting luminescence properties over a wide temperature range (10-360 K). The Yb3+ materials were investigated for their potential use as ratiometric temperature sensors

Designing advanced functional periodic mesoporous organosilicas for biomedical applications

Periodic mesoporous organosilicas (PMOs), reported for the first time in 1999, constitute a new branch of organic-inorganic hybrid materials with high-ordered structures, uniform pore size and homogenous distribution of organic bridges into a silica framework. Unlike conventional mesoporous silicas, these materials offer the possibility to adjust the surface (hydrophilicity/hydrophobicity) and physical properties (morphology, porosity) as well as their mechanical stability through the incorporation of different functional organic moieties in their pore walls. A broad variety of PMOs has been designed for their subsequent application in many fields. More recently, PMOs have attracted growing interest in emerging areas as biology and biomedicine. This review provides a comprehensive overview of the most recent breakthroughs achieved for PMOs in biological and biomedical applications

Analysis of investigation reports on occupational accidents.

The investigation of accidents is an occupational safety analytical tool aimed at discovering the causes of an accident. Conducting these investigations properly is essential to obtain useful information that helps avoid these accidents in the future. To prepare this study we analysed 567 investigations, conducted by OHS technical advisors, on occupational accidents occurring in Spain from 2009 to 2012 in industries such as construction, manufacturing, agriculture and services, in order to obtain information to improve the use of this technique. In this study we analyzed how accident investigation reports are made identifying main flaws and omissions. Accident investigations lack details as they often do not consider the variables in the ESAW (European Statistics on Accidents at Work) Project. Likewise, they lack depth in determining the causes associated to active faults, preferably to latent faults, and to the company management and organisation systems. Similarly, they do not comply with the standards recommended by experts. Finally, in the conclusions we recommend two priorities: having a harmonised European model to conduct occupational accident investigations, as well as being able to access databases that collect accident investigation reports of this kind

Thiol-functionalized ethylene periodic mesoporous organosilica as an efficient scavenger for palladium : confirming the homogeneous character of the Suzuki reaction

This work describes the synthesis of thiol-functionalized periodic mesoporous organosilicas (PMOs) prepared using the precursor 1-thiol-1,2-bis(triethoxysilyl)ethane, alone or mixed with 1,2-bis(triethoxysilyl)ethane. The thiol groups incorporated into the structure were found to be efficient for palladium binding. This has allowed these materials to be used as catalysts in the Suzuki cross-coupling reaction of bromobenzene and phenylboronic acid. Their performance has been compared to palladium-supported periodic mesoporous (organo)silicas and important differences have been observed between them. The use of different heterogeneity tests, such as hot filtration test and poisoning experiments, has provided a deep insight into the reaction mechanism and has confirmed that the reaction occurs in the homogeneous phase following a "release and catch" mechanism. Furthermore, the thiol-functionalized periodic mesoporous organosilica, synthesized using only 1-thiol-1,2-bis(triethoxysilyl)ethane as a precursor, has proven to be an efficient palladium scavenger

Using cerium oxides as catalysts for the abatement of trichloroethylene by plasma-catalysis route

In this study, the abatement of trichloroethylene was examined with a negative DC corona/glow discharge with CeO2 catalyst downstream. The abatement with the plasma alone system showed a poor COx selectivity. However, by combining the plasma source with CeO2 catalyst the COx selectivity was greatly improved, proving that this plasma-catalysis route shows great potential as air pollution control technology for low concentrated VOC air streams

Preparation of palladium-supported periodic mesoporous organosilicas and their use as catalysts in the Suzuki cross-coupling reaction

Three periodic mesoporous materials, i.e., two organosilicas with either ethylene or phenylene bridges and one silica, have been used as supports for Pd nanoparticles. All Pd-supported samples (1.0 wt%) were prepared by the incipient wetness method and subsequently reduced in an H2 stream at 200 °C. Both hydrogen chemisorption and temperature programmed reduction experiments revealed significant differences depending on the support. Pd2+ species were more reducible on the mesoporous organosilicas than on their silica counterpart. Also, remarkable differences on the particle morphology were observed by transmission electron microscopy. All Pd-supported samples were active in the Suzuki cross-coupling reaction between bromobenzene and phenylboronic acid

Assessment of Chainsaw Operators Training in Andalusia (Spain)

The chainsaw, as a work equipment, is considered one of the most dangerous in the field of occupational health and safety. The chainsaw is especially used in the forestry sector, although it is also used in other different sectors such as agriculture, construction or gardening. This study was carried out using an ad-hoc questionnaire as a research tool in order to assess the weaknesses in the training received by workers who use chainsaws in Andalusia, Spain, since it has never been addressed before. To achieve the objective set, the questionnaire was completed by 378 operators working with chainsaw and their responses were analysed. The results of this study show that there are obvious shortcomings related to work with chainsaws in very significant aspects for the occupational health and safety. Of special importance is the lack of training detected on rescue techniques and work at height, since these are aspects of special risk for workers’ health that could cause accidents with severe injuries. Also, a common denominator in all aspects studied was the lack of safety inspections and the state of the equipment to be used. These results evidence that there is a need to regulate chainsaw operator training

Análisis de la siniestralidad laboral en trabajadores por cuenta propia en España (2019-2020).

Tras la puesta en vigor del Real Decreto-ley 28/2018, de 28 de diciembre, se produjo un cambio inusual que afectaba a la contabilización de los accidentes laborales en lo trabajadores por cuenta propia en España, dado que debían cotizar la totalidad de contingencias cuando antes era voluntario. El presente estudio tiene como objetivo conocer el estado de la siniestralidad laboral de los trabajadores por cuenta propia tras la aparición de esta nueva legislación. Para alcanzar el objetivo planteado, se efectúa el análisis de 68.378 accidentes laborales en trabajadores autónomos obtenidos a partir de las Estadísticas de siniestralidad laboral del Ministerio de Trabajo y Economía Social del Gobierno de España entre los años 2019 y 2020. Se ha estudiado la evolución de los índices de incidencia de accidentes de trabajo ocurridos en jornada laboral divididos por sector, sección, comunidad autónoma, edad y género del accidentado. Los resultados obtenidos muestran que el sector de la construcción es el de mayor índice de siniestralidad. La Comunidad Foral de Navarra tiene el mayor índice de incidencia a pesar de no ser la comunidad con mayor número de accidentes laborales de autónomos, siendo los autónomos varones de 16 a 24 años los que tienen mayor tasa de siniestralidad laboral. Estos resultados plantean conclusiones relevantes para mejorar la actividad diaria del colectivo del trabajador autónomo tan importante y esencial para la economía española.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Medios nativos digitales en América Latina. Enfoques, retos y experiencias

El panorama de los medios de comunicación ha cambiado: de las grandes empresas editoras de periódicos, generalmente propiedad de grupos familiares, a los medios nativos digitales financiados por los propios periodistas o por oenegés gracias a los aportes ciudadanos o iniciativas de recaudación de fondos y suscriptores. Este texto dibuja un panorama general de lo que significan los medios digitales y revisa las experiencias de algunos medios de Ecuador, Colombia, Perú y Argentina. En el caso ecuatoriano, se analiza la cobertura de un hecho particular -las movilizaciones de octubre de 2019- por parte de tres medios: Wambra EC, La Periódica y el Centro de Medios Virtuales de la Carrera de Comunicación de la UPS

Development of a mobile application for the virtualization of science laboratories

Desde la inclusión de España en la Declaración de Bolonia, cuyo objetivo es reformar el sistema universitario a través del Espacio Europeo de Educación Superior (EEES), el alumno adquiere un papel de liderazgo en el proceso de enseñanza-aprendizaje. Con el fin de promover la autonomía entre los estudiantes en el proceso de capacitación, el uso de las Tecnologías de la Información y la Comunicación (TIC) es cada vez más común. Entre ellos, el e-learning con aplicaciones móviles tiene un gran potencial para fortalecer el proceso de aprendizaje, dado su uso popular entre los estudiantes universitarios. Esto se debe principalmente a que estas herramientas tienen una variedad de ventajas sobre los métodos tradicionales, como conferencias magistrales, entre los que cabe citar, entre otras, el que permiten la comunicación profesor-estudiante más allá de los espacios tradicionales, rompiendo las barreras o límites de espacio y tiempo, que favorecen la autonomía (autoaprendizaje) del estudiante o que permiten la presentación de la información en una gran variedad de formas y lenguajes. Además, son fácilmente conectables a las redes sociales, lo que hace que el proceso de aprendizaje sea más atractivo, más accesible y más cooperativo. Con el propósito de aumentar la motivación de los estudiantes, en este trabajo, se diseñó y desarrolló una aplicación móvil, en la que se han virtualizado tres laboratorios pertenecientes a la Facultad de Ciencias (Biología y Química) y la Escuela Politécnica Superior (Física de Ingeniería Mecánica) de la Universidad de Córdoba. En cada uno de los tres laboratorios, los estudiantes pueden acceder a información multimedia correspondiente a diversos materiales, equipos, videos, enlaces, laboratorios virtuales, así como una explicación de algunas sesiones prácticas. Para el desarrollo de diferentes escenarios, se han utilizado imágenes panorámicas de 360º, que se han realizado utilizando técnicas HDR (High Dynamic Range). La plataforma elegida para el desarrollo fue Android, debido al uso mayoritario de este sistema operativo en dispositivos móviles entre los estudiantes. Conviene destacar que este tipo de e-learning facilita a los estudiantes el acceso a materiales relacionados con las materias prácticas en estudio que son muy importantes en la enseñanza de las ciencias. Además, se familiarizan más con los términos técnicos de una manera interactiva, más entretenida y eficiente, mejorando el grado de motivación y la participación del estudiante en los temas en estudio. Esto conduce a una mayor asimilación de conocimientos y habilidades. Para verificar esto, para cada laboratorio, dividimos a los estudiantes en un grupo sin acceso a la aplicación (grupo de control) y otro (grupo de prueba) con acceso. Llevamos a cabo una serie de cuestionarios con los grupos de prueba usando la plataforma basada en juegos "Kahoot!" y Google Forms. Los cuestionarios intentaron aclarar el grado de aceptación de la herramienta, el impacto en el aprendizaje de los temas en estudio y la identificación de posibles áreas de mejora. En general, los estudiantes del grupo de prueba encontraron la herramienta muy interesante y les ayudó a mejorar sus puntuaciones en comparación con el grupo de control. No se aprecia una distinción clara entre los estudiantes de diferentes materias. Entre los aspectos a mejorar, se encuentra el contenido relativamente limitado de esta primera versión. Además, la evaluación se realizó con un único grupo control y un grupo de prueba en cada materia, lo que limita su potencial para extraer conclusiones definitivas. En el futuro, se realizarán más cargas y pruebas de contenido en diferentes cursos para evaluar los beneficios del aprendizaje de ciencias mediante esta aplicación.Since the inclusion of Spain in the Bologna Declaration, whose objective is to reform the university system through the European Higher Education Area (EHEA), the student acquires a leading role in the teaching-learning process. In order to promote autonomy among the students in the training process, the use of Information and Communication Technologies (ICT) is increasingly common. Among them, e-learning using mobile apps has a great potential to strengthen the learning process given its popular use among university students. This is mostly because these tools have assorted advantages over traditional methods, e.g. magisterial lectures, such as ubiquitous access, possibility to update and increase content, self-learning, etc. Moreover, they are easily linkable to social media, thus making the learning process more attractive, more easily accessible and more cooperative. For the purpose of increasing student motivation, in this work, a mobile application has been designed and developed, in which three laboratories, belonging to the faculties of Sciences (Biology and Chemistry) and Engineering, have been virtualized. In each of the three laboratories, the students can access to some multimedia information corresponding to various materials and equipment, videos, links, virtual laboratories as well as an explanation of some practical sessions. For the different scenarios development, 360º panoramic pictures have been used, which have been made using HDR (High Dynamic Range) techniques. The platform chosen for the development was Android, due to the majority use of this operating system on mobile devices among the students. It is good to notice that this type of e-learning facilitates students the accessibility to materials related to the practical subjects under study which are very important in science teaching. Furthermore, they become more familiar with technical terms in an interactive, more entertaining and efficient manner, improving the motivation degree and the student's involvement in the subjects under study. This leads to a greater assimilation of knowledge and skills. To verify this, for each laboratory, we divided the students in a group without access to the app (control group) and another one (testing group) with access. We conducted a series of questionnaires with the testing groups using the game-based platform “Kahoot!” and Google Forms. The questionnaires intended to enlighten the degree of acceptance of the tool, the impact on learning of the subjects under study and the identification of potential areas of improvement. Generally, the testing group students found the tool very interesting and helped them improving their scores compared to the control group. No clear distinction between students of different subjects was appreciated. A limited content in this first version was major drawback. Moreover, this evaluation has been conducted only with one control and one testing group of each subject, thus limiting its potential to extract definite conclusions. Further content upload and testing on different courses will be done in the future to evaluate the benefits of science learning using this app