1,845 research outputs found
The Professor-Tutor of Teaching "Prácticum" Like Professional User of Media
En este artículo presentamos un somero resumen de los resultados más interesantes
obtenidos en una tesis doctoral denominada “Uso de los medios en el Prácticum de
Magisterio”. Estos versan sobre la utilización que hacen de los medios y recursos los
profesores-tutores durante el periodo en el que el estudiante de magisterio esta
realizando las prácticas bajo su asesoría y supervisión.This article shows a brief resume about the more interesting results gotten in a doctoral
thesis titled: “The use of the technological and traditional resources during the teacher
training Practicum”. In this text, we analyse the data obtain about the use of this
resources by the tutor-teachers when they are tutoring student-teachers
Order in chaos: Structure of chaotic invariant sets of square-wave neuron models
Bursting phenomena and, in particular, square-wave or fold/hom bursting, are found in a wide variety of mathematical neuron models. These systems have different behavior regimes depending on the parameters, whether spiking, bursting, or chaotic. We study the topological structure of chaotic invariant sets present in square-wave bursting neuron models, first detailed using the Hindmarsh–Rose neuron model and later exemplary in the more realistic model of a leech heart neuron. We show that the unstable periodic orbits that form the skeleton of the chaotic invariant sets are deeply related to the spike-adding phenomena, typical from these models, and how there are specific symbolic sequences and a symbolic grammar that organize how and where the periodic orbits appear. Linking this information with the topological template analysis permits us to understand how the internal structure of the chaotic invariants is modified and how more symbolic sequences are allowed. Furthermore, the results allow us to conjecture that, for these systems, the limit template when the small parameter ¿, which controls the slow gating variable, tends to zero is the complete Smale topological template
Localización del equipamiento hotelero en Leicestershire. Implicaciones en su articulación territorial
Revaluation of underutilized lemon fruits of southeastern Spain as a potential source of bioactive compounds and to be used in creative cuisine
In the present research colour, weight, morphological parameters and total antioxidant activity (TAA) of the edible tissues of three underutilised cultivars of lemon fruits was quantified. In addition, other fruit quality properties, such as organics acids and sugars concentrations in the lemon juices were analysed. Also, the evaluation of organoleptic attributes, such as sweetness, aroma, firmness, lack of bitterness, overall impression and notable feature of fruits was performed by a sensory panel. Results show significant differences on the analysed parameters among lemon cultivars. The relative proportion of each fruit tissue was similar for the three cultivars. 'Fino' and 'Sanguino' lemons showed the highest TAA, while the most appreciated by consumers according to the sensory panel results was 'Sanguino' lemon which could be due to their original colour. These traditional cultivars of lemon fruits could be used as ingredients in creative cuisine due to their attractive properties providing also nutritional and antioxidant compounds
Symbolic dynamical unfolding of spike-adding bifurcations in chaotic neuron models
We characterize the systematic changes in the topological structure of chaotic attractors that occur as spike-adding and homoclinic bifurcations are encountered in the slow-fast dynamics of neuron models. This phenomenon is detailed in the simple Hindmarsh-Rose neuron model, where we show that the unstable periodic orbits appearing after each spike-adding bifurcation are associated with specific symbolic sequences in the canonical symbolic encoding of the dynamics of the system. This allows us to understand how these bifurcations modify the internal structure of the chaotic attractors
Effectiveness of hybrid powertrains to reduce the fuel consumption and NOx emissions of a Euro 6d-temp diesel engine under real-life driving conditions
[EN] Recent investigations demonstrated that the real-world driving conditions differ from those proposed in the homologation cycles. This provokes that the emissions levels in real-life conditions exceed the normative values, as shown in the recent scandal related to the NOx emissions from the passenger cars equipped with diesel engines. On the other hand, the upcoming emissions regulations will limit the CO2 emissions to very low levels, which demands a further optimization of the existing technology. One way to reduce the NOx and CO2 emissions is by electrifying the powertrain in a certain degree. The objective of this work is to evaluate the potential of implementing a parallel (P2) hybrid architecture in a compact car (class C) equipped with a diesel 1.6 Euro 6d-temp engine to reduce the emissions and fuel consumption in homologation and real-life driving cycles. This has been done using a OD numerical vehicle model and the experimental engine maps of fuel consumption and emissions measured at steady state conditions. After that, the transient conditions were simulated in homologation cycles and real-life driving cycles measured by the authors in Spain. The numerical model was validated against experimental tests carried out in an active engine test bench, evidencing differences below 4% under the worldwide harmonized light vehicles test cycle (WLTC). In the real-life cycles, the hybridization of the powertrains improves the fuel consumption for all types of driving cycles (urban, combined and highway). The major benefits are obtained in urban driving cycles, with gains up to 50% in fuel consumption and CO2 emissions. In addition, the improvements in real-life conditions are higher than in the urban phase of the homologation cycles. On the contrary, combined real-life cycles (urban + rural + highway) show lower benefits than the homologation cycle. This is due to different energy management strategy that needs to be adapted to each driving situation. Lastly, it was found that, contrarily to the case of the homologation cycle, the NOx emissions are not reduced with the hybridization of the diesel powertrain in real-life conditions. Thus, to achieve 2021 CO2 target (95 g/km) and to reduce aftertreatment systems in diesel engines, other vehicles technologies need to be added to the full hybridization.The authors acknowledge FEDER and Spanish Ministerio de Economia y Competitividad for partially supporting this research through TRANCO project (TRA2017-87694-R). The authors also acknowledge the Universitat Politecnica de Valencia for partially supporting this research through Convocatoria de ayudas a Primeros Proyectos de Investigacion (PAID-06-18).Luján, JM.; García Martínez, A.; Monsalve-Serrano, J.; Martínez-Boggio, S. (2019). Effectiveness of hybrid powertrains to reduce the fuel consumption and NOx emissions of a Euro 6d-temp diesel engine under real-life driving conditions. Energy Conversion and Management. 199:1-18. https://doi.org/10.1016/j.enconman.2019.111987S11819
Variabilidad espacial de los efectos socioeconómicos de las explotaciones de esquí alpino en los municipios rurales del Pirineo aragonés
22 páginas, 9 figuras, 4 tablas.[ES] Desde mediados del siglo XX se han impulsado las estaciones de
esquí alpino en el Pirineo Aragonés, para incentivar las actividades turísticas y
generar nuevas vías de desarrollo socio-económico. Transcurridos más de 30 años
desde la construcción de las estaciones de esquí, cabe plantearse ¿en qué medida han
contribuido a un desarrollo homogéneo en el territorio o han contribuido a desequilibrios
espaciales? En este trabajo se estudian los efectos del turismo en la dinámica
de la población (evolución del censo, cambios en la estructura demográfica y distribución
de la población activa) y en el sector primario (evolución del número de explotaciones
y de los censos ganaderos). Los resultados obtenidos en este trabajo permiten
concluir que en el Pirineo Aragonés las estaciones de esquí afectan a un área
espacial bastante reducida. En los municipios incluidos en ella se observan resultados
positivos respecto a la evolución demográfica y negativos en el mantenimiento
del sector primario. En los municipios no afectados por las estaciones de esquí, los
resultados son totalmente diferentes, mostrando una evolución muy negativa de la
población y positiva de los censos ganaderos[EN] Tourist activities, especially those related to skiing, have been
promoted in the central Spanish Pyrenees since the 1950s. Using a 30-year dataset
extending back to before the development of most ski resorts in the Pyrenees, we
analysed the effects of ski resort development on the human population (change in
the number of inhabitants, demographic structure and structure of the working sector)
and the primary production activities of the area (number of farms and livestock).
Spatial differences that have occurred in the socioeconomic changes since ski
resort construction began are also analysed. Results show that the area influenced by
ski resorts is restricted to the municipalities nearest to them. These municipalities
show positive demographic changes and a negative evolution of primary activities.
The municipalities more distant from the ski resorts show the opposite pattern. The
advantages and problems of ski resort-based tourism in relation to the sustainable
development of the Pyrenees are discussed in depth.[FR] Depuis la moitié du XXème siècle des nombreuses stations de ski
alpin ont été créées dans les Pyrénées Aragonaises a fin de promouvoir les activités
touristiques et de favoriser le développement socio-économique dans la région. Trente
années sont passées depuis la construction des dernières stations de ski, et il faut se
demander dans quelle mesure elles ont contribué à un développement homogène dans
le territoire ou à des déséquilibres spatiaux. Dans ce travail on étudie les effets du
tourisme sur la dynamique de la population (évolution de la population, changements de la structure démographique et de la distribution de la population active)
ainsi que sur le secteur primaire (évolution du nombre d´exploitations et des effectifs
de l’élevage). Les résultats obtenus dans ce travail permettent de conclure que dans
les Pyrénées Aragonaises les stations de ski affectent des espaces assez réduits. On
observe, dans les communes des zones affectées, des résultats positifs concernant
l´évolution démographique, et négatifs quant au maintien du secteur primaire. Dans
les communes qui ne sont pas affectées par les stations de ski les résultats sont très
différents, avec une évolution très négative de la population et positive des effectifs
animaux.Este trabajo se ha realizado con la ayuda de los proyectos: GGL2005-
04863/CLI, CGL2005-04508/BOS, financiados por la CICYT y FEDER,
PIP098/2005 y PIP176/2005, financiados por el Gobierno de Aragón, y
“Programa de grupos de investigación” (BOA 48 de 20-04-2005), también
financiados por el Gobierno de Aragón.Peer reviewe
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