28,696 research outputs found
Socioeconomic effects of protected areas in Spain across spatial scales and protection levels
Impacts of the legal designation of protected areas (PAs) may have contrasting implications for different stakeholders, and at different spatial scales. In this study, we analysed the organisational perception on the socioeconomic effects of PA designation from all sectors of activity in Spain, accounting for PAs’ legal stringency. A semi-structured questionnaire was administered to 68 organisations at national, regional (Andalusia) and local scales (two municipalities in the Almeria province, Andalusia) through an online survey. Local stakeholders and the primary, secondary and tertiary sectors were most concerned about the social and economic impacts of PAs designation on their organisations. By contrast, organisations at the national or regional scales together with public institutions, the quaternary sector and other miscellaneous stakeholders perceived predominantly positive effects. Only national organisations perceived an increase in local social and economic effects from the designation of legally stringent PAs with regard to multiple-use PAs
Self-similar transmission properties of aperiodic Cantor potentials in gapped graphene
We investigate the transmission properties of quasiperiodic or aperiodic
structures based on graphene arranged according to the Cantor sequence. In
particular, we have found self-similar behaviour in the transmission spectra,
and most importantly, we have calculated the scalability of the spectra. To do
this, we implement and propose scaling rules for each one of the fundamental
parameters: generation number, height of the barriers and length of the system.
With this in mind we have been able to reproduce the reference transmission
spectrum, applying the appropriate scaling rule, by means of the scaled
transmission spectrum. These scaling rules are valid for both normal and
oblique incidence, and as far as we can see the basic ingredients to obtain
self-similar characteristics are: relativistic Dirac electrons, a self-similar
structure and the non-conservation of the pseudo-spin. This constitutes a
reduction of the number of conditions needed to observe self-similarity in
graphene-based structures, see D\'iaz-Guerrero et al. [D. S. D\'iaz-Guerrero,
L. M. Gaggero-Sager, I. Rodr\'iguez-Vargas, and G. G. Naumis,
arXiv:1503.03412v1, 2015]
Renormalization of spin-orbit coupling in quantum dots due to Zeeman interaction
We derive analitycally a partial diagonalization of the Hamiltonian
representing a quantum dot including spin-orbit interaction and Zeeman energy
on an equal footing. It is shown that the interplay between these two terms
results in a renormalization of the spin-orbit intensity. The relation between
this feature and experimental observations on conductance fluctuations is
discussed, finding a good agreement between the model predictions and the
experimental behavior.Comment: 4 pages, no figures. To appear in Phys. Rev. B (Brief Report) (2004
Heterogeneous Extractive Batch Distillation of Chloroform - Methanol – Water : Feasibility and Experiments
A novel heterogeneous extractive distillation process is considered for separating the azeotropic mixture chloroform – methanol in a batch rectifying column, including for the first time an experimental validation of the process. Heterogeneous heavy entrainer water is selected inducing an unstable ternary heteroazeotrope and a saddle binary heteroazeotrope with chloroform (ternary diagram class 2.1-2b). Unlike to well-known heterogeneous azeotropic distillation process and thanks to continuous water feeding at the column top, the saddle binary heteroazeotrope chloroform – water is obtained at the column top, condensed and further split into the liquid – liquid decanter where the chloroform-rich phase is drawn as distillate. First, feasibility analysis is carried out by using a simplified differential model in the extractive section for determining the proper range of the entrainer flowrate and the reflux ratio. The operating conditions and reflux policy are validated by rigorous simulation with ProSim Batch Column® where technical features of a bench scale distillation column have been described. Six reproducible experiments are run in the bench scale column matching the simulated operating conditions with two sequentially increasing reflux ratio values. Simulation and experiments agree well. With an average molar purity higher than 99%, more than 85% of recovery yield was obtained for chloroform and methanol
Interplay between Zeeman interaction and spin-orbit coupling in a two-dimensional semiconductor system
We analyse the interplay between Dresselhaus, Bychkov-Rashba, and Zeeman
interactions in a two-dimensional semiconductor quantum system under the action
of a magnetic field. When a vertical magnetic field is considered, we predict
that the interplay results in an effective cyclotron frequency that depends on
a spin-dependent contribution. For in-plane magnetic fields, we found that the
interplay induces an anisotropic effective gyromagnetic factor that depends on
the orientation of the applied field as well as on the orientation of the
electron momentum.Comment: 5 page
Automatic speech recognition with deep neural networks for impaired speech
The final publication is available at https://link.springer.com/chapter/10.1007%2F978-3-319-49169-1_10Automatic Speech Recognition has reached almost human performance in some controlled scenarios. However, recognition of impaired speech is a difficult task for two main reasons: data is (i) scarce and (ii) heterogeneous. In this work we train different architectures on a database of dysarthric speech. A comparison between architectures shows that, even with a small database, hybrid DNN-HMM models outperform classical GMM-HMM according to word error rate measures. A DNN is able to improve the recognition word error rate a 13% for subjects with dysarthria with respect to the best classical architecture. This improvement is higher than the one given by other deep neural networks such as CNNs, TDNNs and LSTMs. All the experiments have been done with the Kaldi toolkit for speech recognition for which we have adapted several recipes to deal with dysarthric speech and work on the TORGO database. These recipes are publicly available.Peer ReviewedPostprint (author's final draft
Materias primas y cadenas operativas en el yacimiento EpipaleolÃtico de El Roc del Migdia (Vilanova de Sau, Barcelona)
En esta comunicación se pretende dar a conocer los últimos resultados de la investigación que se está llevando a cabo en el yacimiento epipaleolÃtico del Roc del Migdia (Barcelona). Se ofrecen las dotaciones absolutas de los niveles excavados durante las últimas campañas, asà como un pequeño avance de los datos paleoecológicos. Se incide principalmente en el estudio del material lÃtico perteneciente a este yacimiento, el cual pone de manifiesto la importancia de la correlación entre la naturaleza de las materias primas y la tecnologÃa, que en este caso se traduce en la identificación de diferentes cadenas operativas según se trate de cada materia prima (cuarzo, caliza y sÃlex). Se define el concepto de cadena operativa como un proceso que abarca desde la captación de la materia prima hasta la utilización o deshecho de las piezas resultantes de su transformación.This communication presents the latest results of the research being carried out at the epipalaeolithic site of Roc del Migdia (Barcelona). Absolute dates are presented for the levels excavated during the last two seasons, as weli as a preliminary review of the palaeoenvironmental data. The main emphasis is on the study of the chipped-stone industry, demonstrating the importance of the correlation between the technology used and the nature of the raw material, which in this case means the identification of different cadenas operativas according to the raw material used (quartz, limestone or chert). The cadena operativa is defined as the entire process from the obtaining of the raw material to the using or discarding of the pieces resulting from its transformation
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