The granites of Galicia used as industrial rock

[Resumen] Se han estudiado todos los tipos de rocas graníticas de la Comunidad Autónoma de Galicia para su utilización como roca industrial: áridos y piedra natural. El mercado de los áridos y la industria de la Piedra Natural son dos subsectores mineros de primer orden, tanto en Galicia como en el resto de España, con producciones globales en granitoides de 10 Mt (millones de toneladas) y un valor anual cercano a los 31.000 Mpts (millones de pesetas) para Galicia. Los tipos litológicos beneficiados son: granitoides inhomogéneos, granitos de dos micas, granitos biot1ticos y ortogneises, cuyas diferencias petrológicas, texturales y mineralógicas van a condicionar su nivel de calidad en uno y otro mercado.[Abstract] We have studied aH the types of granitic rocks of the region of Galicia, for their use as an industrial rock in aggregates and natural stone. The aggregate market and the natural stone industry are very important mining subsection, as much in Galicia as in the rest of Spain, with general granite productions of 10 Mt (millions of tonnes) and 31.000 Mpts (miHions of pesetas) as the annual value in Galicia. The types of mining rocks are: inhomogeneous granite, two mica granite, biotite granite and granite gneiss, whose petrological, textural and mineralogical differences determine their quality level in both uses

Non-local quantum effects in plasmons of graphene superlattices

By using a non-local, quantum mechanical response function we study graphene plasmons in a one-dimensional superlattice (SL) potential $V_0 \cos G_0x$. The SL introduces a quantum energy scale $E_G \sim \hbar v_F G_0$ associated to electronic sub-band transitions. At energies lower than $E_G$, the plasmon dispersion is highly anisotropic; plasmons propagate perpendicularly to the SL axis, but become damped by electronic transitions along the SL direction. These results question the validity of semiclassical approximations for describing low energy plasmons in periodic structures. At higher energies, the dispersion becomes isotropic and Drude-like with effective Drude weights related to the average of the absolute value of the local chemical potential. Full quantum mechanical treatment of the kinetic energy thus introduces non-local effects that delocalize the plasmons in the SL, making the system behave as a meta-material even near singular points where the charge density vanishes.Comment: 22 pages, 14 figure

Anti-DNA antibodies and circulating immune complexes (C1q-IgG) in recurrent aphtous stomatitis

Anti-DNA antibodies and circulating immune complexes (C1q-IgG) in sera from 50 patients with minor aphtae at the moment of study and 50 healthy controls, were determined. The obtained results were correlated with chronological and clinical parameters of the disease. Our findings show a greater number of patients than controls with higher values of anti-DNA antibodies. The time from the last active stage of the disease conditioned the anti-DNA antibody levels (p< 0.001). However, no significant differences among the number of recurrences in a year or the number of lesions in a ulcerative stage and the anti-DNA antibody concentrations were observed.Cette étude a pour but de déterminer les anticorps anti-ADN et les complexes immuns circulants C1q-IgG dans le sérum de 50 patients qui présentaient des aphtes mineurs au moment de l’étude et chez 50 contrôles. Les résultats obtenus sont en rapport avec les paramètres cliniques et chronologiques de la maladie. Nous avons trouvé des niveaux plus élevés d’anticorps anti-ADN chez les patients avec des aphtes mineurs, en comparaison avec les contrôles. Il existait une corrélation entre ces niveaux d’anticorps anti-ADN et le temps écoulé depuis le dernier épisode de la maladie (p<0.001). Il n’existait cependant pas de différences significatives entre les concentrations anti-ADN ni en ce qui concerne le nombre de récidives ni le nombre de lésions durant l’épisode

Enhancing Transport Efficiency by Hybrid Routing Strategy

Traffic is essential for many dynamic processes on real networks, such as internet and urban traffic systems. The transport efficiency of the traffic system can be improved by taking full advantage of the resources in the system. In this paper, we propose a dual-strategy routing model for network traffic system, to realize the plenary utility of the whole network. The packets are delivered according to different "efficient routing strategies" [Yan, et al, Phys. Rev. E 73, 046108 (2006)]. We introduce the accumulate rate of packets, {\eta} to measure the performance of traffic system in the congested phase, and propose the so-called equivalent generation rate of packet to analyze the jamming processes. From analytical and numerical results, we find that, for suitable selection of strategies, the dual- strategy system performs better than the single-strategy system in a broad region of strategy mixing ratio. The analytical solution to the jamming processes is verified by estimating the number of jammed nodes, which coincides well with the result from simulation.Comment: 6 pages, 3 figure

An Emulator Toolbox to Approximate Radiative Transfer Models with Statistical Learning

Physically-based radiative transfer models (RTMs) help in understanding the processes occurring on the Earth’s surface and their interactions with vegetation and atmosphere. When it comes to studying vegetation properties, RTMs allows us to study light interception by plant canopies and are used in the retrieval of biophysical variables through model inversion. However, advanced RTMs can take a long computational time, which makes them unfeasible in many real applications. To overcome this problem, it has been proposed to substitute RTMs through so-called emulators. Emulators are statistical models that approximate the functioning of RTMs. Emulators are advantageous in real practice because of the computational efficiency and excellent accuracy and flexibility for extrapolation. We hereby present an “Emulator toolbox” that enables analysing multi-output machine learning regression algorithms (MO-MLRAs) on their ability to approximate an RTM. The toolbox is included in the free-access ARTMO’s MATLAB suite for parameter retrieval and model inversion and currently contains both linear and non-linear MO-MLRAs, namely partial least squares regression (PLSR), kernel ridge regression (KRR) and neural networks (NN). These MO-MLRAs have been evaluated on their precision and speed to approximate the soil vegetation atmosphere transfer model SCOPE (Soil Canopy Observation, Photochemistry and Energy balance). SCOPE generates, amongst others, sun-induced chlorophyll fluorescence as the output signal. KRR and NN were evaluated as capable of reconstructing fluorescence spectra with great precision. Relative errors fell below 0.5% when trained with 500 or more samples using cross-validation and principal component analysis to alleviate the underdetermination problem. Moreover, NN reconstructed fluorescence spectra about 50-times faster and KRR about 800-times faster than SCOPE. The Emulator toolbox is foreseen to open new opportunities in the use of advanced RTMs, in which both consistent physical assumptions and data-driven machine learning algorithms live together

Time dependence of breakdown in a global fiber-bundle model with continuous damage

A time-dependent global fiber-bundle model of fracture with continuous damage is formulated in terms of a set of coupled non-linear differential equations. A first integral of this set is analytically obtained. The time evolution of the system is studied by applying a discrete probabilistic method. Several results are discussed emphasizing their differences with the standard time-dependent model. The results obtained show that with this simple model a variety of experimental observations can be qualitatively reproduced.Comment: APS style, two columns, 4 figures. To appear in Phys. Rev.

Proliferative verrucous leukoplakia : a proposal for diagnostic criteria

Proliferative verrucous leukoplakia (PVL) is a rare form of oral leukoplakia, which was first described in 1985 by Hansen et al. Since then, various published case series have presented PVL as a disease with aggressive biological behaviour due to its high probability of recurrence and a high rate of malignant transformation, usually higher than 70%. PVL is a long-term progressive condition, which is observed more frequently in women and elderly patients over 60 years at the time of diagnosis. Eventually, PVL tends to become multifocal with a progressive deterioration of the lesions, making it more and more difficult to control. Tobacco use does not seem to have a significant influence on the appearance or progression of PVL. These lesions may occur both in smokers and nonsmokers. Nevertheless, at present, the aetiology of PVL remains unclear as well as its management and diagnosis, which is still retrospective, late and poorly defined, lacking consensus criteria. Therefore, the aim of this study is to propose a set of diagnostic criteria to allow for the early and objective identification of PVL cases, and thereby conduct an adequate management. The proposal includes five major criteria and four minor criteria, as well as specific combinations among them in order to establish a correct and objective diagnosis of proliferative verrucous leukoplakia

Robustness of Cooperation in the Evolutionary Prisoner's Dilemma on Complex Networks

Recent studies on the evolutionary dynamics of the Prisoner's Dilemma game in scale-free networks have demonstrated that the heterogeneity of the network interconnections enhances the evolutionary success of cooperation. In this paper we address the issue of how the characterization of the asymptotic states of the evolutionary dynamics depends on the initial concentration of cooperators. We find that the measure and the connectedness properties of the set of nodes where cooperation reaches fixation is largely independent of initial conditions, in contrast with the behavior of both the set of nodes where defection is fixed, and the fluctuating nodes. We also check for the robustness of these results when varying the degree heterogeneity along a one-parametric family of networks interpolating between the class of Erdos-Renyi graphs and the Barabasi-Albert networks.Comment: 18 pages, 6 figures, revised version accepted for publication in New Journal of Physics (2007