1,423 research outputs found
An Active Instance-based Machine Learning method for Stellar Population Studies
We have developed a method for fast and accurate stellar population
parameters determination in order to apply it to high resolution galaxy
spectra. The method is based on an optimization technique that combines active
learning with an instance-based machine learning algorithm. We tested the
method with the retrieval of the star-formation history and dust content in
"synthetic" galaxies with a wide range of S/N ratios. The "synthetic" galaxies
where constructed using two different grids of high resolution theoretical
population synthesis models. The results of our controlled experiment shows
that our method can estimate with good speed and accuracy the parameters of the
stellar populations that make up the galaxy even for very low S/N input. For a
spectrum with S/N=5 the typical average deviation between the input and fitted
spectrum is less than 10**{-5}. Additional improvements are achieved using
prior knowledge.Comment: 14 pages, 25 figures, accepted by Monthly Notice
Framing the Europeanization footprint : a follow-up of the EU renewable electricity directive and its impact in Spai
És àmpliament conegut que l'europeïtzació ha guanyat molt terreny en els estudis europeus. Des de finals de la dècada de 1990, ha gaudit d'una important expansió per tal d'avaluar l'eficàcia de les polítiques a escala europea en l'àmbit intern. En aquest procés la política energètica ha jugat un paper molt paradoxal, sent persistentment exclosos de l'agenda de recerca de la europeïtzació, encara que la seva creixent importància en l'elaboració de polítiques comunitàries. No obstant això, la realitat és que, tot i haver estat reconegut recentment com una àrea de la UE amb l'aplicació del Tractat de Lisboa, també ha estat influenciat, directament o indirectament, pels efectes de l'europeïtzació. Com a resultat d'això, la política energètica ha estat considerat com un "cas especial" de l'europeïtzació, portant fins al moment per a la construcció d'un sector caracteritzat la política energètica europea. En aquest context, el present treball pretén explicar l'europeïtzació de les polítiques energètiques nacionals en l'elaboració de l'actuació de la UE per mitjà de la seva competència ambiental. Més explícitament, aquesta investigació tracta de la naturalesa de la reglamentació comunitària en matèria d'energia renovable com un mecanisme d'europeïtzació amb especial èmfasi en el seu impacte a Espanya. Aquest treball sosté que (1) la lluita europea contra el canvi climàtic s'ha obert un camí per a la participació de la UE en matèria de política energètica, i que (2) encara que limitat aquest procés està produint alguns canvis en les polítiques energètiques nacionals. UniversitatIt is widely known that Europeanization has gained considerable ground in European studies. Since the late 1990's, it has enjoyed an important expansion in order to assess the effectiveness of the European-level policies at the domestic level. In this process energy policy has played a very paradoxical role, being persistently excluded from the Europeanization research agenda even though its growing importance in the EU policy-making. However, the reality is that, in spite of having being recently recognized as an EU area with the Lisbon Treaty enforcement, it has also been influenced, directly or indirectly, by Europeanization effects. As a result, energy policy has been considered as a "very special case" of Europeanization, leading so far to the construction of a sector-characterized European energy policy. In this context, this paper intends to explain the Europeanization of national energy policies by framing the EU performance by means of its environmental competence. More explicitly, this research deals with the nature of the Community regulation in the renewable electricity area as an Europeanization mechanism with a special focus on its impact in Spain. This paper argues that (1) the European fight against climate change has opened a path for EU participation in energy policy; and that (2) although limited this process is producing some changes in national energy polici
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Preparing for entry into the workforce: Educational attainment for CalWORKS students
This study concerns an evaluation of a community college support services program. The study participants included 58 female CalWORKS students. Data was gathered from a self-administered survey questionnaire designed specifically for this study to gather student\u27s level of satisfaction with program services. Practice, policy and research implications were discussed
Perspectives on the green construction of the new European Energy Policy
The EU has been one of the main actors involved in the construction process of an international climate change regime, adopting it as an identity sign in the international arena. This activism has reverted in the European political agenda and in the one of its Members States. Therefore, climate change has become a driver for the EU growing participation in energy policy and for its governance evolution. In this context, much attention has been paid to the climate and energy policies integration agreed after the 2007 spring European Council. Apparently, this decision meant a decisive step towards the incorporation of the environmental variable in the energy policy-making. Moreover, the Action Plan [2007-2009] "Energy Policy for Europe" outlined priority actions in a variety of energy-related areas, implying the new European Energy Policy commencement. Against this background, there is still much left to understand about its formulation and its further development. Rooted on the Environmental Policy Integration approach, this paper traces the increasing proximity between environment and energy policies in order to understand the green contribution to the European Energy Policy construction.La UE ha estat un dels principals actors involucrats en el procés de construcció d'un canvi climàtic internacional règim, adoptant-com un senyal d'identitat en l'àmbit internacional. Aquest activisme s'ha revertit en la política europea ordre del dia i en la dels seus estats membres. Per tant, el canvi climàtic s'ha convertit en un motor per al creixement de la UE participació en la política energètica i de la seva evolució govern. En aquest context, s'ha prestat molta atenció a la climàtic i les polítiques d'integració energètica acordat després de 2007 el Consell Europeu de primavera. Pel que sembla, aquesta decisió significar un pas decisiu cap a la incorporació de la variable ambiental en la política energètica de decisions. D'altra banda, el Pla d'Acció [2007-2009] "Política Energètica per a Europa", indica les accions prioritàries en una varietat d'àrees relacionades amb l'energia, el que implica el nou començament de la Política Europea de l'Energia. En aquest context, encara hi ha molt per entendre sobre la seva formulació i el seu desenvolupament posterior. Arrelat a la Integració de Polítiques Ambientals enfocament, aquest document descriu la creixent proximitat entre el medi ambient i les polítiques energètiques per tal de comprendre la contribució verda a la construcció de Política Energètica Europe
Hydrometallurgical recovery of critical metals from NMC 523 powders and its associated environmental impacts
The lithium-ion battery industry’s accelerated growth is raising interest in the recycling of valuable metals. Lithium, manganese, cobalt, and nickel can be recovered from the cathode powders using inorganic acids like hydrochloric acid (HCl), nitric acid (HNO3), and sulfuric acid (H2SO4) in the leaching process. The experiments were designed using a statistical tool to optimize the parameters involved in the leaching process such as temperature, leaching time, concentration of leaching agents, solid to liquid ratio, and %volume of H2O2 to yield the best results for lithium recovery (%), nickel recovery (%), cobalt recovery (%) and manganese recovery (%). This study provides optimized leaching parameters, a detailed environmental impact assessment to identify the best inorganic acid in each category as well as the component contribution for each inorganic acid in all the categories included in the life cycle assessment (LCA) study, and a comparison of co-additives using the optimal conditions of the best performing leaching agent. The optimal conditions for each acid were H2SO4: 1.97 M, 69.99ºC, 20 min, L/S:0.091, and 0.957 H2O2 conc. (v/v%), HCl: 1.611 M, 69.99ºC, 89.9 min, L/S:0.098, and 0.99 %H2O2 conc (v/v%), and HNO3: 0.62 M, 58.2ºC, 58.7 min, L/S:0.097 and 0.66 H2O2 conc. (v/v%). After analyzing the environmental performance for each acid, it was found that depending on the impact category, each acid has more emissions than the others. Overall, H2SO4 showed the best environmental and operational performance among all inorganic acids to recover critical materials from NMC 523 cathode powders
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