224 research outputs found
Strengths and obstacles for quality assurance in the European Higher Education Area: The Spanish case
Trabajo presentado a la International Conference on Engineering Education & Research celebrada del 23 al 28 Agosto de 2009 en Seul (Corea del Sur).Quality assurance and accreditation in higher education are a priority aim in the convergence process to the European Higher Education Area (EHEA). Although the majority of European universities are working
around these issues, there exist diverse tensions between the national legislation, accreditation and quality assurance, both in internal and external contexts. Spanish Higher Education Institutions must ensure the
fulfillment of the goals related to their different degree programs, in a context of continuous improvement. This paper presents the evolution, some examples and the more recent trends related to quality assurance and accreditation in Spain. It comments some instruments that have been developed by the National Agency for Quality Assessment and Accreditation of Spain (ANECA), like the guidelines developed in the AUDIT program whose purpose is to provide guidance in designing internal quality assurance systems.Peer reviewe
Effect of Reynolds number and lithium cation insertion on titanium anodization
This work studies the influence of using hydrodynamic conditions (Reynolds number, Re = 0 to Re = 600) during Ti anodization and Li+ intercalation on anatase TiO2 nanotubes. The synthesized photocatalysts were characterized by using Field Emission Scanning Electron Microscope (FE-SEM), Raman Confocal Laser Microscopy, Electrochemical Impedance Spectroscopy (EIS), Mott-Schottky analysis (M-S), photoelectrochemical hydrogen production and resistance to photocorrosion tests. The obtained results showed that the conductivity of the NTs increases with Li+ intercalation and Re. The latter is due to the fact that the hydrodynamic conditions eliminate part of the initiation layer formed over the tube-tops, which is related to an increase of the photocurrent in the photoelectrochemical water splitting. Besides, the photogenerated electron-hole pairs are facilitated by Li+ intercalation. Finally, this work confirms that there is a synergistic effect between Re and Li+ intercalation
El audiorae como estrategia para la visibilización de las comprensiones de los profesores de ciencias naturales
The purpose of the workshop is to recognize the AUDIORAE as a strategy to make students' comprehensions visible and as a means of evaluating the actions undertaken in the natural science classroom. The AUDIORAE involves in its production elements of information analysis through an academic summary of writings, and in its communication through a short audio recording that contains the central ideas and critical thinking.
In this workshop, correlated actions are developed, such as the "Generate, Classify, Connect and Elaborate" (GCCE) thinking routine, designed for the construction of conceptual maps that demonstrate mental models (Ritchhart, 2015) from the capacity for synthesis and the relationship of ideas; and the production of an audio whose purpose is to make visible the comprehensions of a text, video or classroom exercise, in addition to the metacognitive process that accompanies the whole exercise. Together the two actions have been called AUDIORAE, concept proposed from the product that is obtained, a short audio and the medium that involves in relation to the analytical summary of writings (RAE).El propósito del taller es reconocer el AUDIORAE como estrategia de visibilización de las comprensiones de los estudiantes y como medio de evaluación de las acciones emprendidas en el aula de ciencias naturales. El AUDIORAE involucra en su producción elementos de análisis de información a través de un resumen académico de escritos, y en su comunicación a través de una grabación corta en audio que contenga las ideas centrales y pensamiento crítico.
En este taller, se desarrollan acciones correlacionadas como la rutina de pensamiento “Generar, Clasificar, Conectar y Elaborar (GCCE)” pensada para la construcción de mapas conceptuales que evidencian modelos mentales (Ritchhart, 2015) desde la capacidad de síntesis y relación de ideas; y la producción de un audio cuyo fin es hacer visibles las comprensiones de un texto, video o ejercicio de aula, además del proceso metacognitivo que acompaña todo el ejercicio. En conjunto las dos acciones han sido denominadas AUDIORAE, concepto propuesto desde el producto que se obtiene, un audio de corta duración y el medio que involucra en relación con el resumen analítico de escritos (RAE)
Impacto de la pizarra luminosa en estudiantes de contaduría pública de estadística inferencial y fundamentos de matemáticas.
Diagnosticar el uso de la pizarra luminosa en cursos cuantitativos.El uso de recursos que inviten al estudiante a estar más comprometido con su proceso educativo puede incrementar su desempeño. El objetivo del estudio es encontrar el nivel de apreciación percibido en el uso de la pizarra luminosa en dos cursos cuantitativos y establecer las diferencias entre el sexo y la situación laboral de los estudiantes participantes. Se utilizó como instrumento una encuesta que diligenciaron los 97 participantes. Se encontró que el 82% de los estudiantes preferían los videos elaborados por el mismo profesor que orientaba la asignatura, el 82% prefirió verle la cara al profesor mientras escribe en el tablero. En las 3 dimensiones, comprensión, compromiso y satisfacción, se obtuvo 97%, 94% y 95% respectivamente en la categoría “Totalmente de acuerdo”. La apreciación total en relación con el sexo no presentó diferencias significativas, al igual que con la situación laboral
Should TiO2 nanostructures doped with Li+ be used as photoanodes for photoelectrochemical water splitting applications?
Different TiO2 nanostructures, nanotubes and nanosponges, were obtained by anodization of Ti under stagnant and hydrodynamic conditions. Samples were doped with Li+ before and after annealing at 450 °C during 1 h. The nanostructures were characterized by different microscopy techniques: Field Emission Scanning Electron Microscopy (FE-SEM) and Raman Confocal Laser Microscopy. Additionally, Incident Photon-to-electron Conversion Efficiency (IPCE), photoelectrochemical water splitting and stability measurements were also performed. According to the results, TiO2 nanostructures doped before annealing present the worst photocurrent response, even if compared with undoped samples. On the other hand, this study reveals that Li+-doped TiO2 nanostructures doped after annealing can be used as durable and stable photoanodes for photoelectrochemical water splitting applications
Forage Yield and Nutritive Value of 30 Cultivars of Maize for Silage in the Highland Valleys of Central Mexico
In Mexico, the selection of maize cultivars for forage has mainly been based on dry matter (DM) yields, not considering nutritional quality as an important evaluation parameter. The objective of this study was to assess forage yield and nutritive value of Highland and Subtropical maize cultivars for silage in the Highland Valleys of Central México
Synergistic effect between hydrodynamic conditions during Ti anodization and acidic treatment on the photoelectric properties of TiO2 nanotubes
In the present work, the combined influence of controlled hydrodynamic conditions during Ti anodization and the acidic treatment with HClO4 on the photoelectric properties of mixed anatase/rutile TiO2 nanotubes has been studied. Anodized samples were analyzed by means of Field Emission Scanning Electronic Microscopy (FE-SEM), Confocal Raman Microscopy, electrochemical measurements (electrochemical impedance spectroscopy and Mott-Schottky analysis) and photoelectrochemical measurements. It has been observed that the use of hydrodynamic conditions increases the surface area of nanotubes, while acidic treatment enhances their conductivity. Besides, there is a clear synergistic effect between the hydrodynamic conditions and the acidic treatment, which results in higher photocurrent densities for the treated nanotubes formed under hydrodynamic conditions.Authors would like to express their gratitude for the financial support to the Ministerio of Economia y Competitividad (Project CTQ2013-42494-R).Sánchez Tovar, R.; Fernández Domene, RM.; Martinez Sanchez, A.; Blasco Tamarit, ME.; García-Antón, J. (2015). Synergistic effect between hydrodynamic conditions during Ti anodization and acidic treatment on the photoelectric properties of TiO2 nanotubes. Journal of Catalysis. 330:434-441. https://doi.org/10.1016/j.jcat.2015.08.002S43444133
Unmanned aerial vehicles (UAVs) as a tool for hazard assessment: The 2021 eruption of Cumbre Vieja volcano, La Palma Island (Spain)
Monitoring for assessment of natural disasters, such as volcanic eruptions, presents a methodological challenge for the scientific community. Here, we present Unmanned Aerial Vehicles (UAVs) as a feasible, precise, rapid and safe tool for real time monitoring of the impacts of a volcanic event during the Cumbre Vieja eruption on La Palma Island, Spain (2021). UAV surveys with optical RGB (Red-Green-Blue), thermal and multispectral sensors, and a water sampling device, were carried out in different areas affected by the lava flow, including the upper volcanic edifice and the lava delta formed on the coastal fringe of the island. Our results have provided useful information for the monitoring of the advance of the lava flow and its environmental consequences during the volcanic emergency. Our data shows how La Palma island's growth, with the formation of a new lava delta of 28 ha and a total volume of lava injected into the sea of 5,138,852 m3. Moreover, our Digital Elevation Model (DEM) simulated, with a 70 % accuracy, the probabilistic simulation of the possible path followed by the lava flow in the vicinity of the fissure from which the magma emanates. In addition, significant changes of seawater physical-chemical parameters were registered in coastal surface waters by the in situ seawater samples collected with the automatic water sampling device of our UAV. The first meters of the water column, due to the instant evaporation of the seawater in contact with the hot lava, produce an increase of temperature and salinity of up to 4–5 °C and up to 5 units, respectively.En prensa3,25
TiO2 Nanostructures for Photoelectrocatalytic Degradation of Acetaminophen
Advanced oxidation processes driven by renewable energy sources are gaining attention in degrading organic pollutants in waste waters in an efficient and sustainable way. The present work is focused on a study of TiO2 nanotubes as photocatalysts for photoelectrocatalytic (PEC) degradation of acetaminophen (AMP) at different pH (3, 7, and 9). In particular, different TiO2 photocatalysts were synthetized by stirring the electrode at different Reynolds numbers (Res) during electrochemical anodization. The morphology of the photocatalysts and their crystalline structure were evaluated by field emission scanning electron microscopy (FESEM) and Raman confocal laser microscopy (RCLM). These analyses revealed that anatase TiO2 nanotubes were obtained after anodization. In addition, photocurrent densities versus potential curves were performed in order to characterize the electrochemical properties of the photocatalysts. These results showed that increasing the Re during anodization led to an enhancement in the obtained photocurrents, since under hydrodynamic conditions part of the initiation layer formed over the tubes was removed. PEC degradation of acetaminophen was followed by ultraviolet-visible absorbance measurements and chemical oxygen demand tests. As drug mineralization was the most important issue, total organic carbon measurements were also carried out. The statistical significance analysis established that acetaminophen PEC degradation improved as hydrodynamic conditions linearly increased in the studied range (Re from 0 to 600). Additionally, acetaminophen conversion had a quadratic behavior with respect to the reaction pH, where the maximum conversion value was reached at pH 3. However, in this case, the diversity of the byproducts increased due to a different PEC degradation mechanism
Original Approach to Synthesize TiO2/ZnO Hybrid nanosponges used as photoanodes for photoelectrochemical applications
[EN] In the present work, TiO2/ZnO hybrid nanosponges have been synthesized for the first time. First, TiO2 nanosponges were obtained by anodization under hydrodynamic conditions in a glycerol/water/NH4F electrolyte. Next, in order to achieve the anatase phase of TiO2 and improve its photocatalytic behaviour, the samples were annealed at 450 degrees C for 1 h. Once the TiO2 nanosponges were synthesized, TiO2/ZnO hybrid nanosponges were obtained by electrodeposition of ZnO on TiO2 nanosponges using different temperatures, times, and concentrations of zinc nitrate (Zn(NO3)(2)). TiO2/ZnO hybrid nanosponges were used as photoanodes in photoelectrochemical water splitting tests. The results indicate that the photoelectrochemical response improves, in the studied range, by increasing the temperature and the Zn(NO3)(2) concentration during the electrodeposition process, obtaining an increase in the photoelectrochemical response of 141% for the TiO2/ZnO hybrid nanosponges electrodeposited at 75 degrees C with 10 mM Zn(NO3)(2) for 15 min. Furthermore, morphological, chemical, and structural characterization was performed by Field Emission Scanning Electron Microscopy (FE-SEM) with Energy Dispersive X-Ray spectroscopy (EDX), Raman Confocal Laser Spectroscopy, X-Ray Photoelectron Spectroscopy (XPS), and Grazing Incidence X-Ray Diffraction (GIXRD).The authors would like to express their gratitude for the financial support of the
¿Agencia Estatal de Investigación (PID2019-105844RB-I00/MCIN/AEI/10.13039/501100011033)¿,
for the co-finance by the European Social Fund, and for its help in the ¿Laser Raman Microscope
acquisition (UPOV08-3E-012) ¿. Pedro José Navarro Gázquez also thanks the Grant PEJ2018-003596-A-AR funded by MCIN/AEI/10.13039/501100011033 and by ¿ESF Investing in your future¿.Navarro-Gázquez, PJ.; Muñoz-Portero, M.; Blasco-Tamarit, E.; Sánchez-Tovar, R.; Fernández-Domene, RM.; Garcia-Anton, J. (2021). Original Approach to Synthesize TiO2/ZnO Hybrid nanosponges used as photoanodes for photoelectrochemical applications. Materials. 14(21):1-21. https://doi.org/10.3390/ma14216441S121142
- …