764 research outputs found
On the determinants of local tax rates: new evidence from Spain
This paper studies the determinants of local tax rates. For the two main local taxes in Spain - the property tax and the motor vehicle tax - we test the existence of tax mimicking, yardstick competition and political trends in a sample of 2,713 municipalities. Using different spatial models, the results support the hypothesis of tax mimicking, with coefficients over 0.40. We also show the relevance of political variables such as the ideology of the incumbents and political fragmentation. The fact that incumbents with weaker political support display stronger mimicking behaviour is interpreted as evidence in favour of yardstick competition. Finally, we find incumbents mimic neighbouring municipalities ruled by the same political party, confirming the political trends hypothesis.Local taxation, tax mimicking, yardstick competition, political trends
DOC 2017-03 International and Intercultural Leadership Certificate
Legislative Authority; Art. III. B. 1-7; DOC 2015-0
Effect of the axial jet on the optimal response in Batchelor vortex
En este pĂłster se estudia la respuesta Ăłptima del torbellino de Batchelor para distintos nĂşmeros de onda. Se demuestra que incluso teniendo la velocidad axial, un torbellino es capaz de tener grandes amplificaciones de energĂa.Universidad de MĂĄlaga. Campus de Excelencia Internacional AndalucĂa Tech
Wingtip vortex in a NACA0012 airfoil and its active control
ContribuciĂłn mediante sesiĂłn pĂłsterWe conduct experiments in a towing-tank to analyse the flow patterns of wingtip vortices in a NACA 0012 airfoil. In this experimental research, we provide PIV measurements and flow visualisations. Without active control, several parameters are given experimentally as function of the Reynolds number, so we compare these data with the theoretical models of Batchelor, and Moore and Saffman together with DNS. Secondly, we analyse the effect of a continuous injection in the spanwise direction. The continuous jet has a strong influence on the wing-tip vortex formation. We explore this effect at low chord based Reynolds number ranging from 7000 up to 20000. We change the aspect ratio of the injection, R, defined as the ratio of the velocities between the jet (Uj) and free-stream (U). For R=1, we find that the jet strongly affects the wingtip vortex formation with a sudden decrement of the axial vorticity and the azimuthal velocity. This technique is a challenge and a promising tool to reduce the intensity of the vortex core.Universidad de MĂĄlaga. Campus de Excelencia Internacional AndalucĂa Tech
Influence of Reynolds number on theoretical models for trailing vortices
We conduct direct numerical simulations for a NACA0012 airfoil at Reynolds numbers (Re) ranging from 300 to 7000 to determine the wake behavior behind this wing profile. We characterize the structure of the wing-tip vortex, finding a reasonable agreement with experimental results at Re=7000. In addition, we model the trailing vortex theoretically, thus obtaining the parameters for Batchelorâs and Moore and Saffmanâs models. We compare the results of the best fitting for the axial vorticity and the azimuthal velocity, finding only small discrepancies. The main contribution of this research work is to study the evolution of these theoretical parameters as function of the Reynolds number. We observe that the wake becomes unstable at Re â1200, in agreement with previous results. These instabilities in the wake behind the wing produce a change in the trend of theoretical parameters (keywords: vortex dynamics, trailing vortices, theoretical models).Universidad de MĂĄlaga. Campus de Excelencia Internacional AndalucĂa Tech
An evaluation of freshwater monitoring programs in ILTER nodes and mountain national parks: identifying key variables to monitor global change effects
Acknowledgements This study was funded by the European Commission, under the LIFE Nature and Biodiversity program, as part of the project LIFE-DIVAQUA (Proyecto LIFE18 NAT/ES/000121). We also like
to thank all the Spanish government agencies and research institutions who provided information, answered
the questionnaires and participated in the workshop âSynthesis of the monitoring programs of global change
in aquatic ecosystems SMNP: Autonomous Organism of National Parks, MAPAMA-Dir. Gral. Agua, Universidad
de Granada, Instituto Universitario de InvestigaciĂłn del Agua, (IdeA-UGR), Universidad PolitĂŠcnica
de Madrid, CISE-P.N. Sierra de Guadarrama, FundaciĂłn Biodiversidad, CEAB-CSIC, IGME, MNCN-CSIC,
Universidad de CĂłrdoba, Universidad de Barcelona and ICTA-UAB. We also like to thank the 28 European
Nation Parks who responded our query. The authors finally thank the support provided by Christoph Wohner
in the use of the DEIMS-SDR.Electronic supplementary material The online version contains supplementary material available at https://doi.org/10.1007/s10531-022-02466-x.Data Availability The datasets used to review the monitoring programs at the Global scale conducted in the
ILTER nodes that are included in Rivers (ILTER-Rivers) or Lakes (ILTER-Lakes) are available at the DEIMS
dataset registry (DEIMS-SDR) (for more details see: Wohner et al. 2019; https://deims.org/). The datasets
used to review the monitoring programs at the European scale conducted in the EMNP are available by
requesting them via email to the corresponding EMNP. The datasets used to review the monitoring programs
at the National scale conducted in the five SMNP are mostly included in this article and it supplementary
information file. In addition, meteorological data recorded by the Spanish Global Change Monitoring Network
in available at the Meteorological data download web application (https://www.miteco.gob.es/es/redparques-
nacionales/red-seguimiento/acceso-datos.aspx). Further and more detailed information is available
from the corresponding author on reasonable request.Funding This study was carried out with the financial support of the EU LIFE programme, as part of the project
LIFE-DIVAQUA (Proyecto LIFE18 NAT/ES/000121). The information showed in this publication only
reflects the point of view of the authors. The European Comission and CINEA cannot be held responsible for
any use which be made of the information contained here.
Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature.Identifying and quantifying global change impacts on biotic and abiotic components of ecosystems is critical to promote an effective adaptation that increases the success of conservation strategies. To achieve this goal, global and regional assessment efforts require certain degree of harmonization on local monitoring programs to establish relevant comparisons at different spatio-temporal scales. Otherwise, the lack of harmonization might hinder the detection and assessment on the effects of human impacts. In this work we have compiled information on freshwater monitoring programs located in areas of intensive research and conservation interest: International Long Term Ecological Research (ILTER) nodes and mountain National Parks. We aimed at evaluating the quality and robustness of these programs to assess the impact of global change, addressing from the worldwide to the European and Spanish national scale. Results highlighted that freshwater monitoring programs lack a common strategy to monitor these ecosystems. Even at the continental and national scales, contrasting strategies and level of detail have been historically applied. Water quality, habitat and biodiversity are more commonly monitored than community structure and ecosystem functioning. Monitoring efforts on the Spanish Mountain National parks indicated differences on the targeted aquatic ecosystems. Rivers and lakes received a higher attention, while mires were rarely considered. Our results provide evidence that greater efforts should be directed towards constructing a coordinated strategy to monitor freshwater ecosystems at national, continental, and global scales. This strategy should involve a shared backbone of biophysical and biogeochemical variables for each habitat type on agreed protocols that are implemented across regions and administrative borders. Achieving this will support a substantial advance on the ecological research to further delineate proper conservation strategies to face the challenges imposed by global change.European Commission
LIFE18 NAT/ES/00012
A comparison of modeling techniques to predict hydrological indices in ungauged rivers
Predicting the natural flow regime in ungauged rivers is an important challenge in water resource management and ecological research. We developed models to predict 16 hydrological indices in a river network covering the northern third of the Iberian Peninsula. Multiple Linear Regression (MLR), Generalized Additive Models (GAMs), Random Forest (RF) and Adaptive Neuro Fuzzy Inference System (ANFIS) were used and compared according to their prediction accuracy. The results showed that predictive performance varied greatly depending on the modeled hydrological attribute. The magnitude and frequency indices were predicted with excellent accuracy. In contrast, no technique was capable of developing precise models for hydrological indices of timing, duration and rate of change. This is mainly related to the lack of proper environmental databases on the scales on which these flow regime patterns are influenced. In addition, complex modeling techniques did not always outperform linear models and no single approach was optimal for all indices. ANFIS and GAMs provided the best results; however, other issues such as computational cost and the level of knowledge required to apply the method and interpret the results should be taken into account.This study was partly funded by the Spanish Ministry of Economy and Competitiveness as part of the HYDRA (Ref. BIA2015-71197) and RIVERLANDS (Ref. BIA2012-33572) projects
Evaluating Variable-Length Multiple-Option Lists in Chatbots and Mobile Search
In recent years, the proliferation of smart mobile devices has lead to the
gradual integration of search functionality within mobile platforms. This has
created an incentive to move away from the "ten blue links'' metaphor, as
mobile users are less likely to click on them, expecting to get the answer
directly from the snippets. In turn, this has revived the interest in Question
Answering. Then, along came chatbots, conversational systems, and messaging
platforms, where the user needs could be better served with the system asking
follow-up questions in order to better understand the user's intent. While
typically a user would expect a single response at any utterance, a system
could also return multiple options for the user to select from, based on
different system understandings of the user's intent. However, this possibility
should not be overused, as this practice could confuse and/or annoy the user.
How to produce good variable-length lists, given the conflicting objectives of
staying short while maximizing the likelihood of having a correct answer
included in the list, is an underexplored problem. It is also unclear how to
evaluate a system that tries to do that. Here we aim to bridge this gap. In
particular, we define some necessary and some optional properties that an
evaluation measure fit for this purpose should have. We further show that
existing evaluation measures from the IR tradition are not entirely suitable
for this setup, and we propose novel evaluation measures that address it
satisfactorily.Comment: 4 pages, in Proceeding of SIGIR 201
Equilibrium, kinetics and breakthrough curves of acetaminophen adsorption onto activated carbons from microwave-assisted FeCl3-activation of lignin
Activated carbons have been prepared by chemical activation of lignin with FeCl3 using microwave (MW) heating. The use of MW significantly reduced the activation time compared to conventional heating. Microwave power, impregnation ratio (R: mass ratio of FeCl3 to lignin precursor) and MW holding time have been studied as variables affecting the development of porous texture. The optimum conditions were found at 800 W, R = 5 and 30 min MW heating time. Under those conditions an essentially microporous activated carbon was obtained, with BET surface area higher than 1150 m2¡gâ1 and acidic surface, whose pH at the point of zero charge was 4.2. This activated carbon was tested for the adsorption of acetaminophen, as model emerging contaminant, from aqueous phase. The adsorption isotherms, obtained at 20, 40 and 60 °C, fitted well to RedlichâPeterson model. The maximum acetaminophen adsorption reached about 300 mg¡gâ1 at 60 °C. Values of 35.5 kJ¡molâ1 and 238.3 J¡molâ1¡Kâ1 were obtained for the enthalpy and entropy of adsorption, respectively. Those positive values are indicative of an endothermic process and increased randomness at the solid/solution interface upon adsorption. The adsorption kinetics was better described by pseudo-second order driving force model. Breakthrough curves were also obtained at different adsorption temperatures, flow rates and acetaminophen inlet concentrations. They fitted well to a logistic-type equation representative of the Bohart-Adams, Thomas and Yoon-Nelson models. Adsorbent regeneration with hot water (80 °C) revealed easy and complete desorption thus providing a promising view of the potential application of this activated carbonThe authors acknowledge the financial support from the State Research Agency (PID2019-106186RB-I00/AEI/10.13039/501100011033, Spain). M. Penas-GarzĂłn thanks Spanish MECD for FPU16/00576 gran
- âŚ