Perfil del trabajo que desempeñan los diplomados de la especialidad de ciencias por la Escuela Universitaria del Profesorado de E.G.B. de la Universidad de Alicante

This paper offers a general profile of the jobs of the graduates from the Escuela Universitaria del Profesorado de EGB de Alicante. The study has been done by means of a survey, that has examined the degree of adequacy between university training in science and the professional activity in primary education

A Sustainable Approach to Selective Hydrogenation of Unsaturated Esters and Aldehydes with Ruthenium Catalysts

The reduction of esters and aldehydes to alcohols is an important reaction in the chemical industry to produce a wide range of bulk and fine chemicals. Herein, the unexpected behavior of three state-of-the-art, commercially available Ru-catalysts for the hydrogenation of these feedstocks is reported. For ester and aldehydes containing a C=C bond, it was possible to carry out the selective hydrogenation of the ester or aldehyde functionality while keeping the C=C double-bond essentially untouched. Furthermore, it is demonstrated that these substrates can be reduced under very mild reaction conditions (as low as 40 °C and 5 bar of H2) and that anisole, a solvent with a high sustainability rank, is suitable for these catalytic hydrogenations

Función del área de gestión humana en el proceso de adaptación ante los cambios organizacionales derivados de la pandemia percibida por un grupo de trabajadores del sector minero en Colombia

Objetivo. Analizar la función del área de gestión humana en el proceso de adaptación ante los cambios organizacionales derivados de la pandemia del Covid-19 percibida por un grupo de trabajadores del sector minero en Colombia. Método. Se realizó un estudio cualitativo descriptivo de corte transversal; el diseño de la investigación fue un estudio de caso basado en entrevistas semiestructuradas a diez (10) empleados con mínimo dos (2) años de servicio. Resultado. Los datos obtenidos nos permitieron comprender la función de gestión humana en el proceso de adaptación de los empleados, su aporte fundamental para facilitar la implementación de estrategias, medidas y acciones orientadas a mitigar este impacto inesperado del Covid-19 en las empresas mineras en Colombia. Se demuestra que gestión humana como socio estratégico ayudó a el cumplimiento e implementación de las medidas corporativas en los empleados. Conclusión. Se evidenció que no solo los países no estaban preparados para esta pandemia, las organizaciones no fueron ajena a este impacto, y las empresas mineras quienes mantienen implementado un sistema de controles de seguridad para poder tener la dinámica operativa de sus procesos, si bien los empleados perciben que gestión humana fue importante en el proceso de adaptación, los empleados han notado la disminución del liderazgo de gestión humana una vez alcanzada la etapa de implementación, están manifestando sentirse solos en la parte final si se pudiese decir del proceso de adaptación ante los cambios organizacionales originados por la pandemia del Covid-19.Objective. Analyze the role of the human management area in the process of adaptation to the organizational changes derived from the Covid-19 pandemic perceived by a group of workers in the mining sector in Colombia. Method. A qualitative descriptive cross-sectional study was carried out; The research design was a case study based on semi-structured interviews with ten (10) employees with a minimum of two (2) years of service. Outcome. The data obtained allowed us to understand the human management function in the employee adaptation process, its fundamental contribution to facilitate the implementation of strategies, measures and actions aimed at mitigating this unexpected impact of Covid-19 in mining companies in Colombia. It is shown that human management as a strategic partner helped the compliance and implementation of corporate measures in employees. Conclusion. It was evidenced that not only the countries were not prepared for this pandemic, the organizations were not oblivious to this impact, and the mining companies who maintain a system of security controls in place in order to have the operational dynamics of their processes, although the employees They perceive that human management was important in the adaptation process, employees have noticed the decrease in human management leadership once the implementation stage has been reached, they are manifesting that they feel alone in the final part if it could be said of the adaptation process in the face of changes organizational problems caused by the Covid-19 pandemic

Sarcoma de Ewing extraóseo en cabeza y cuello: revisión de la literatura a propósito de un caso

ResumenIntroducciónEl sarcoma de Ewing extraesquelético (SEE) es un tumor maligno muy poco frecuente. La región de la cabeza y el cuello es una localización primaria inusual para este tipo de tumor.Material y métodosEl objetivo de esta revisión es identificar las principales localizaciones dentro de cabeza y cuello. Para ello se realizó una búsqueda en la base de datos MEDLINE. Se analizaron múltiples variables. Se realiza la revisión a propósito un caso clínico de un paciente con SEE en la mejilla.ResultadosDe un total de 31 pacientes, se reportan 18 casos en cabeza y 13 en cuello.ConclusionesEn nuestra revisión no pudimos determinar ninguna localización que sea de mayor frecuencia en esta región. Las pruebas de imagen son útiles para estadificar, y son necesarios estudios anatomopatológicos para confirmar el diagnóstico. El tratamiento intensivo es el de mayor eficacia.AbstractIntroductionExtraskeletal Ewing's sarcoma (EES) is a rare malignant neoplasm. It is a highly unusual finding in the head and neck region.Material and methodsThe aim of this review is to identify the main sites in the head and neck region, by searching in the MEDLINE database. A wide range of variables were analysed. This review was carried out due to a case report of a patient with EES of the cheek.ResultsOut of a total of 31 patients, there were 18 cases in the head and 13 in the neck.ConclusionsIn our review it was not possible to determine a more frequent head and neck location. The imaging studies are useful for staging, and the histology to confirm the diagnosis. An aggressive treatment has demonstrated to be more effective

Starch Modified With Chitosan and Reinforced With Feather Keratin Materials Produced by Extrusion Process: An Alternative to Starch Polymers

They also reached up to 3800% and 3150% in maximum strength, respectively, compared to the matrix. The lysozyme test showed relevant changes in the degradability rate, because the weight loss of the films at 3 weeks decreased from 53% for starch-chitosan matrix and up to 34% for composites with 5wt% of modified quill. The results corroborated that chicken feather materials can be useful for the development of a manufacturing process for starch composites, and the decomposition of starch-chitosan composites can be controlled depending on the content and type of keratin.Starch (potato), chitosan, and feather keratin are used for processing biodegradable films produced by extrusion. The morphology of the films is examined with a scanning electron microscope and showed the excellent dispersion of keratin. The dispersion is the result of compatibility between the polysaccharides and proteins, as well as the proper operation of the extrusion process. Water solubility of the starch-chitosan films decreased with an increase of keratin materials. The storage modulus increased up to 137% for the composites with unmodified ground quill, and by 192% for composites with modified ground quill. In a tensile test, the composites with unmodified and modified quill reached outstanding increments up to 8160 and 7250% in elastic modulus, respectively, compared to the matrixUniversidad Autonoma del Estado de Mexico Tecnologico Nacional de Mexico Universidad Nacional Autonoma de Mexico Universidad Autonoma de Cd. Juare

Bandgap widening in macroporous silicon photonic crystals by multiperiodic structures

Large bandgaps with low transmission in 3D macroporous silicon photonic crystals have been proved as an interesting technology for the development of optical filters and spectroscopic MIR gas sensors. The aim of this study is the investigation of different bandgap widening methods based on multiperiodic structures for 3D macroporous silicon photonic crystals. To do so, chirped modulations and structures with different periodicity groups have been modelled and theoretically analysed by means of 3D FDTD simulations. They have revealed that by using different decreasing periodicity groups, bandgaps with null transmission and widths as high as 1800 nm, 4 times the original single periodicity photonic crystal bandgap, can be obtained. Furthermore, it has been shown that a resonant cavity with a 20% transmission can be placed in a 1 µm wide bandgap. The results open a way to use this type of structures not only for gas sensing but also for other purposes such as wide stop-band filters, selective filters or broadband mirrors.Peer ReviewedPostprint (published version

Reinforced silica-carbon nanotube monolithic aerogels synthesised by rapid controlled gelation

This work introduces a new synthesis procedure for obtaining homogeneous silica hybrid aerogels with carbon nanotube contents up to 2.50 wt.%. The inclusion of nanotubes in the highly porous silica matrix was performed by a two-step sol–gel process, resulting in samples with densities below 80 mg/cm3. The structural analyses (N2 physisorption and SEM) revealed the hierarchical structure of the porous matrix formed by nanoparticles arranged in clusters of 100 and 300 nm in size, specific surface areas around 600 m2/g and porous volumes above 4.0 cm3/g. In addition, a relevant increase on the mechanical performance was found, and an increment of 50% for the compressive strength and 90% for the maximum deformation were measured by uniaxial compression. This reinforcement was possible thanks to the outstanding dispersion of the CNT within the silica matrix and the formation of Si–O–C bridges between nanotubes and silica matrix, as suggested by FTIR. Therefore, the original synthesis procedure introduced in this work allows the fabrication of highly porous hybrid materials loaded with carbon nanotubes homogeneously distributed in the space, which remain available for a variety of technological applications

Integrating plasmonic supercrystals in microfluidics for ultrasensitive, label-free, and selective surface-enhanced raman spectroscopy detection

Surface-enhanced Raman spectroscopy (SERS) microfluidic chips for label-free and ultrasensitive detection are fabricated by integrating a plasmonic supercrystal within microfluidic channels. This plasmonic platform allows the uniform infiltration of the analytes within the supercrystal, reaching the so-called hot spots. Moreover, state-of-the-art simulations performed using large-scale supercrystal models demonstrate that the excellent SERS response is due to the hierarchical nanoparticle organization, the interparticle separation (IPS), and the presence of supercrystal defects. Proof-of-concept experiments confirm the outstanding performance of the microfluidic chips for the ultradetection of (bio)molecules with no metal affinity. In fact, a limit of detection (LOD) as low as 10–19 M was reached for crystal violet. The SERS microfluidic chips show excellent sensitivity in the direct analysis of pyocyanin secreted by Pseudomonas aeruginosa grown in a liquid culture medium. Finally, the further integration of a silica-based column in the plasmonic microchip provides charge-selective SERS capabilities as demonstrated for a mixture of positively and negatively charged molecules.Agencia Estatal de Investigación | Ref. TEC2017-85376-C2-1-RAgencia Estatal de Investigación | Ref. TEC2017-85376-C2-2-RXunta de Galicia | Ref. GRC ED431C 2016−486 048Gobierno de Extremadura | Ref. IB18073Agencia Estatal de Investigación | Ref. IJCI-2016-2910

Demonstration of bare Laser reduced Graphene Oxide sensors for Ammonia and Ethanol

This work was mainly supported by TED2021-129949A-I00 funded by MCIN/AEI/10.13039/501100011033. It was also partially funded by the Andalusian regional projects supported through the Junta de Andalucía - Consejería de Universidad, Investigación e Innovación and FEDER funds: ProyExcel_00268, B-RNM-680-UGR20, P20_00265, P20_00633, as well as by the Spanish Ministry of Sciences and Innovation through the National Project PID2020-117344RB-I00, the Ramón y Cajal fellow RYC2019-027457-I and the María Zambrano fellow C21.I4.P1.In this work, gas sensors using laser-reduced graphene oxide (LrGO) as sensitive layer have been fabricated and studied. The laser-synthetized material were structurally and electrically characterized by means of Scanning Electron Microscopy (SEM), Raman spectroscopy, X-ray Photoelectron Spectroscopy (XPS) and the four-point contact method. The gas-sensing properties of the samples were studied by their exposition to 10 ppm to 100 ppm of ethanol and 25 ppm to 130 ppm of ammonia. The results show that the devices present an electrical response corresponding to a purely resistive behavior up to 100 kHz. It is also demonstrated that the resistivity of the sensing layer increases as the gas concentration increases; being of 0.0402 ± 0.001 [%/ppm] for the case of ammonia and 0.0140 ± 0.001 [%/ppm] for the case of ethanol. These results outperform existing sensors and establish a better balance in terms of simplicity, sensitivity, linearity and technology sustainability. In summary, this work especially shows the potential of LrGO for low-cost and low-energy gas sensors fabrication.MCIN/AEI/10.13039/501100011033: TED2021-129949A-I00Junta de AndalucíaFEDER funds: ProyExcel_00268, B-RNM-680-UGR20, P20_00265, P20_00633Spanish Ministry of Sciences and Innovation PID2020-117344RB-I00Ramón y Cajal fellow RYC2019-027457-IMaría Zambrano fellow C21.I4.P