Search results for "energía"
showing 10 items of 107 documents
Bounds on the tau and muon neutrino vector and axial vector charge radius
2002
A Majorana neutrino is characterized by just one flavor diagonal electromagnetic form factor: the anapole moment, that in the static limit corresponds to the axial vector charge radius . Experimental information on this quantity is scarce, especially in the case of the tau neutrino. We present a comprehensive analysis of the available data on the single photon production process $e^+ e^- -> \nu \bar\nu \gamma$ off Z-resonance, and we discuss the constraints that these measurements can set on for the tau neutrino. We also derive limits for the Dirac case, when the presence of a vector charge radius is allowed. Finally, we comment on additional experimental data on $\nu_\mu$ scattering from t…
Enseñanza de las ciencias : revista de investigación y experiencias didácticas
2021
Resumen. La conservación de la energía es uno de los conceptos más importantes de la física porque unifi ca todos los fenómenos. En este artículo presentamos algunos resultados de una investigación sobre el proceso de enseñanza-aprendizaje del concepto de energía y su conservación realizado en el nivel de la educación secundaria española. El análisis de los datos pone de manifiesto que la conservación de la energía se introduce en mecánica y termodinámica pero no en todos los campos de la física. Los resultados experimentales se han utilizado para desarrollar un nuevo enfoque de la enseñanza de la energía. Palabras clave. Energía, educación en física, actividades de enseñanza. Summary. The …
On the dynamics of eco-efficiency performance in the European Union
2016
This paper evaluates the evolution of environmental performance in the context of the European Union (EU), over the period 1993–2010. The context is particularly relevant, due to the traditionally high concerns of the EU about these issues, which has triggered off several initiatives and regulations on environmental protection. In this setting, we conduct a two-stage analysis which develops environmental performance indicators in the first stage for each pair country-year, and evaluates its evolution in the second. More specifically, in the first stage we estimate specific efficiencies for three air-pollutants (CO2e, SO2, NOx), along with an eco-efficiency indicator, for which we use the sl…
Brewer's spent grains as biofuels in combustion-based energy recovery processes: Evaluation of thermo-oxidative decomposition
2022
[EN] The high global generation of wastes and side streams from agri-food production has led to environmental impact and causes nature degradation due to their uncontrolled management. These wastes are profitable materials with significant economic value that could otherwise be exploited as new sources in the feed industry or the production of bioenergy. Among them, brewer¿s spent grain (BSG) is a solid by-product generated in the beerbrewing process that consists of the barley grain husks together with parts of the pericarp and seed coat layer. Although it is rich in fibres and proteins, its main use is currently limited to animal feed or simply deposition to landfills. This study pursues …
SINGLE FACTOR STOCHASTIC MODELS WITH SEASONALITY APPLIED TO UNDERLYING WEATHER DERIVATIVES VARIABLES
2003
This paper estimates single factor stochastic models describing daily air temperature behaviour. We modify classical financial models to reflect temperature seasonality and fit them to a time series representing temperatures in Spain. The estimated models are used in Montecarlo simulations to obtain heating and cooling degree-days, which are used as an underlying reference in weather derivatives. The final goal of this work is to obtain an insight into weather derivative valuation, and so making it easier to manage economic activity risks closely related to temperature (i.e. oil, gas and electricity prices and volumes). En este trabajo se estiman modelos estocásticos unifactoriales que desc…
El conocimiento experto y sus fronteras: el caso del compromiso sociotécnico en torno a la línea de muy alta tensión Francia-España
2011
Des de hace treinta años Francia y Espa ña intentan constr uir una nueva línea eléctrica de muy alta tensión entre los dos pa íses. Este proyecto, que ha sido rechazado por las poblaciones en todo su trazado, se encuentra ya en el punto de confluencia , entre Bai xàs y Figueres . Tras vari os años de lucha, los habitantes y las asociaciones han conseguido que el tendido sea subterráneo. Sin embargo, para algunos opositores al proyecto, esa solución no deja de ser una victoria a medias. Este art ículo se propone analizar las lógicas de movilización ciudadana y el pape l de los expert os en el desarrollo del conflicto, en el contexto energético francés –que intenta dar valor a la concertación…
Triblock SEBS/DVB crosslinked and sulfonated membranes: Fuel cell performance and conductivity
2021
[EN] A set of styrene-ethylene-butylene-styrene triblock copolymer (SEBS) membranes with 10 or 25 wt.% divinyl-benzene (DVB) as a crosslinking agent were prepared and validated. Physicochemical characterization revealed suitable hydrolytic and thermal stability of photo-crosslinked membranes containing 25%wt. DVB and post-sulfonated. These compositions were evaluated in H2/O2 single cells, and electrical and proton conductivities were furtherly assessed. The membranes with the milder post-sulfonation showed greater proton conductivity than those with excessive sulfonation. In terms of electrical conductivity, a universal power law was applied, and the values obtained were low enough for bei…
Development of Stripline Kickers for Low Emittance Rings: Application to the Beam Extraction Kicker for CLIC Damping Rings
2015
163 páginas. Tesis Doctoral del Departamento de Física Atómica, Molecular y Nuclear de la Universidad de Valencia y del Instituto de Física Corpuscular (IFIC).
New frontiers in sustainable energy production and storage
2015
Evidently, one of the most effective ways to reduce CO2 emissions consists in the deployment of renewable energies, with the advantage of securing and expanding the energy supplies of a given country. The main problem that arises is due to the intermittent temporary character of many renewable resources like solar and wind. For this reason, it has been recently concluded that in case of high integration of renewables into the distribution grid (more than about 30% of the electricity mix), the implementation of energy storage systems together with smart grids is necessary. Therefore, renewable energies for large scale power production in country would usually require the availability of a su…
Inverse Malthusianism and Recycling Economics: The Case of the Textile Industry
2020
The current use of natural resources in the textile industry leads us to introduce a new economic concept called inverse Malthusianism describing a context in which population grows linearly and resource consumption grows exponentially. Inverse Malthusianism implies an exponential increase in environmental impact that recycling may contribute to reduce. Our main goal is to extend the analysis of materials selection under the principle of equimarginality proposed by Jevons. As a first result, we show the particular circumstances under which policies excluding recycled supplies are never optimal. We also aim to overcome the difficulties of reducing environmental aspects to monetary units. To …