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Urban great tits (Parus major) sing with a higher minimum frequency than their forest conspecifics. Cultural processes may account at least in part for the song divergence in city birds as great tits learn their repertoire from conspecifics and switch to high pitch song types in presence of background noise. However, in small cities, this process of cultural divergence could be constrained because it is likely that these birds have a greater exchange of song types with the outside. We tested this prediction by recording great tit songs in a small city (Toledo, central Spain) and in a nearby forest. We found that background noise and the peak and the maximum frequency of songs were higher in the city but the minimum frequency did not differ. The pause length was also longer in forest birds. Seventy percent of the song types were shared between Toledo and the nearby forest. These results suggest that the small size of Toledo allows a homogenized cultural wealth, preventing the development of a high pitch song as observed in larger cities.

Structural features that enhance Li mobility in fast ion conductors with perovskite (Li3xLa2/3-xTiO3 series) and Nasicon structure (Li1+xTi2-xAlx (PO4)3 series) have been investigated. From the analysis of quadrupolar interactions, the local symmetry and exchange processes between structural sites occupied by lithium have been deduced to investigate local motions of lithium in conduction paths of analyzed compounds. The study of spin-lattice (T1) and spin-spin (T2) relaxation times made possible the analysis of the temperature dependence of Li residence times at structural sites. The comparison of these values with those deduced from conductivity (ac and dc-measurements) allowed the study of Li-motion mechanisms. The onset of long range motions requires the analysis of low frequency measurements (T2 relaxation and dc-conductivity). The non- Arrhenius behaviour, often observed in fast ion conductors, has been ascribed to order/disorder transitions. At increasing temperatures, Li motions become less correlated, producing the decrement of activation energy. In analyzed compounds, a direct measurement of diffusion coefficients has been obtained from NMR experiments performed with the pulse field gradient (PFG) technique. Finally, it is emphasized the importance of the vacancy percolation in conductivity processes.En esta presentación se analizan los rasgos estructurales que favorecen la movilidad de los iones litio en conductores con estructuras tipo perovskita (serie Li3xLa2/3-xTiO3 ) y Nasicon (serie Li1+xTi2-xAlx (PO4)3). El estudio de las interacciones cuadrupolares ha permitido deducir la simetría local y los procesos de intercambio entre sitios cristalinos ocupados por el litio. El estudio de la variación de los tiempos de relajación spin-red (T1) y spin-spin (T2) con la temperatura, ha permitido deducir los tiempos de residencia de los iones Li en los sitios estructurales. La comparación de estos valores con los deducidos a partir de las conductividades ac y dc, hace posible describir de un modo más preciso la dinámica de los iones. A temperaturas crecientes, los movimientos se vuelven menos correlacionados, produciéndose una disminución de la energía de activación. El análisis de los movimientos a larga distancia requiere medidas a baja frecuencia (medidas de T2 y conductividad-dc). Desviaciones de la conductividad del comportamiento Arrhenius, a menudo observadas en conductores iónicos rápidos, han sido adscritas a transiciones de orden-desorden en las que el movimiento de los iones se hace menos correlacionado. Una medida directa de los coeficientes de difusión ha sido obtenida con la técnica RMN de gradiente de campo pulsado (PFG). Finalmente se analiza la importancia de los fenómenos de percolación de vacantes en los procesos de conducción.

A structural and spectroscopic characterization of crystalline rods of Ce0.4Zr0.6O2 grown by the laser floating zone (LFZ) method is presented. A precursor rod of Ce0.4Zr0.6O2 composition was sintered at 1500 ºC in air atmosphere and then processed by the LFZ technique with a CO2 laser. The processed material was characterized by XRD, SEM and Raman spectroscopy. In the as-grown, dark-color processed rod, the Raman spectrum evolves radially from a t’-like one, corresponding to Ce0.37Zr0.63O2 composition, at the edge of the rod, to a very broad and weak, cubic-like one, at the center. The degree of cerium reduction and oxygen non-stoichiometry were determined through measurements of the electronic Raman spectrum of Ce3+. A strong Ce3+ signal was found at the core of the rod, indicating strong reduction, whereas no Ce3+ signal was detected at the edge. To restore oxygen and Ce4+ content a section of the fiber was reoxidized at 620 ºC for 24 h. A very homogeneous spectrum was found in the reoxidized sample, that was assigned to a t’-phase of composition Ce0.42Zr0.58O2.Presentamos una caracterización estructural y espectroscópica de fibras cristalinas de Ce0.4Zr0.6O2 crecidas mediante fusión zonal asistida por láser (LFZ). Una barra del material precursor, de composición Ce0.4Zr0.6O2, fue sinterizada a 1500 ºC en atmósfera de aire y después procesada por LFZ con un láser de CO2. El material procesado fue caracterizado por difracción de rayos X, microscopía electrónica de barrido y espectroscopía Raman. En la fibra recién procesada, de color gris oscuro, el espectro Raman varía radialmente desde un espectro de tipo t’, correspondiente a una composición Ce0.37Zr0.63O2, en el borde de la fibra, hasta un espectro muy ensanchado y débil, de aspecto cúbico, en el centro. El grado de reducción del cerio y la no estequiometría del oxígeno se determinaron a través de las medidas del Raman electrónico del Ce3+. La señal de Ce3+ era muy intensa en el centro de la fibra, lo que indica una fuerte reducción, mientras que no se detectó en el borde. Para restablecer el contenido de oxígeno y de Ce4+ una parte de la fibra fue reoxidada a 620 ºC durante 24 h. El espectro de la muestra reoxidada, de color amarillo pálido y muy homogénea, fue asignado a una fase t’ de composición Ce0.42Zr0.58O2.

A fully reliable and efficient adaptive control methodology has been long awaited in industry due to the time-varying nature of industrial plants. This paper demonstrates that this kind of adaptive solution is now available and simple to apply by presenting the first application of a methodology called Adaptive Predictive Expert (ADEX) Control in a petrochemical production unit. A description of the plant and the ADEX solution is followed by a comparative analysis of the results obtained with those of the existing conventional PID control. The objectives of the application involving the naphtha splitter at the Puertollano Refinery of Repsol were to establish the viability of ADEX in this environment, increase the quality of the naphtha products by achieving closer compliance with desired specification and maximizing the economic yield. To achieve these objectives it was necessary to enhance the stability of the naphtha splitter by improving control of the principal variables and eliminating a degree of interaction between them which was causing a resonance problem in the column. The application of the ADEX system confirm its viability, demonstrated a marked increase in column stability, significant improvements in levels of control and the elimination of the resonance problems.

The structures of microcline perthites collected from granitic pegmatites have been studied at different observation scales using optical microscopy (OM), X-ray diffraction (XRD), 27Al MASS-NMR spectroscopy, and electron microprobe (EMPA) with Na mappings. Pegmatite perthites are identified as complex systems. During the cooling process, K-rich feldspars display two separated genetic periods of recrystallization, each one with variable intensity along different samples. During the first period, in the mineral structure a progressive construction of macrostructural pseudo-periodic patterns is produced. These regular patterns emerge due to a combined mechanism of non-ergodic Si/Al local ordering and a global cooperative effect of the crystal structure. From the incoherent Na/K interfaces arise transformation fronts (avalanches) which can coalesce longitudinally and juxtapose transversally to self-assemble into irregular domains. Finally, they can evolve up to create regular twin-domains (Albite and Pericline laws) as the crystal unit of the macrostructural building. This selforganization process is activated when the system is open to water circulation acting as a catalyst of Al/Si ordering in the feldspar lattice linked with an external stimulation by shear tectonic stress. During the second period the structural patterns, previously created, are destroyed by (i) relaxation and deformation twinning mechanisms, (ii) coarsening of twin-domains produced by dissolution-precipitation due to aqueous fluids interactions at low temperature, (iii) reorientation of Periclinelaw twin-domains to the Albite-law orientation.Se han estudiado estructuras de feldespatos potásicos triclínicos (microclinas) intercrecidos con feldespatos sódicos en texturas pertíticas procedentes de pegmatitas graníticas a diferentes escalas de observación, mediante microscopía de luz transmitida (MLT), difracción de rayos-X (DRX), resonancia magnética nuclear de alta resolución del núcleo 27Al (RMN), y mapas químicos de contenido en Na por microsonda electrónica (ME). Las pertitas pegmatíticas son sistemas complejos en cuyos feldespatos potásicos se han identificado dos periodos genéticos independientes de recristalización durante el enfriamiento geológico. En el primer periodo, en la estructura mineral se produce la construcción gradual de patrones macroscópicos regulares pseudoperiódicos, como consecuencia del efecto combinado de un ordenamiento local no-ergódico en la distribución Si/Al y de un efecto cooperativo global de la estructura del cristal. Desde las interfases incoherentes con el feldespato sódico surgen frentes de transformación a modo de avalanchas que pueden coalescer longitudinalmente y yuxtaponerse transversalmente para auto-ensamblarse, y finalmente evolucionar hasta formar dominios-macla (leyes Albita y Periclina), como unidad cristalina de construcción de la macroestructura. Estos procesos de auto-organización se activan cuando el sistema está abierto a la circulación de moléculas de agua catalizadoras para el ordenamiento de la red, al tiempo que existe una estimulación externa por tensiones tectónicas de cizalla. Durante el segundo periodo se destruyen los patrones estructurales creados previamente, por: (i) maclados de relajación y deformación, (ii) engrosamientos de dominios por disolución-reprecipitación debidos a interacciones con fluidos acuosos a baja temperatura, (iii) reorientaciones de dominiosmacla según ley Periclina hacia orientaciones de ley Albita.

Eighty six microclines with perthitic texture from seven granitic pegmatites have been collected and studied by X-ray diffraction (XRD), X-ray fluorescence (XRF) and optical microscopy (OM). The statistical distribution of the structural state of the microclines shows a tendency to bimodality and also the coexistence of different triclinicities. Pegmatitic microclines are better described when considered as complex crystals and not as heterogeneous pseudomorphic assemblages after sanidine transformation, because the structural state is organized following structural patterns around the interfase with Na-feldspar veins in macroperthitic texture. This tendency to bimodality allows to distinguish among disordered and ordered microclines linked with static and dynamic genetic regimes of solid state evolution on cooling. The static regime produces limited reequilibration since a surface re-crystallization process of regions with high local Si/Al order occurs along boundaries. The ordering is located next to circulation surfaces because the catalyst aqueous fluids have mainly a channeled motion. The dynamic regime is adaptative and important volumes are re-equilibrated by bulk re-crystallization give rise to an ordered microcline. This behavior can be explained considering that a volumetric flow of catalyst water molecules promote global Si/Al ordering. A transitional regime can be distinguished by partial penetration of water through the structures.Se han muestreado y estudiado ochenta y seis microclinas con textura pertítica procedentes de siete pegmatitas graníticas por difracción de rayos-X (DRX), fluorescencia de rayos-X (FRX) y microscopía óptica de luz transmitida (MLT). La tendencia hacia la bimodalidad estructural y la coexistencia de multitud de estados estructurales se describe considerando las microclinas pegmatíticas no como pseudomorfos heterogéneos sino como cristales complejos. Según ésta descripción, los estados estructurales no están distribuidos al azar sino que están organizados según patrones estructurales en torno a las interfases con el feldespato sódico en venas macropertíticas. La tendencia a la bimodalidad en el estado estructural permite distinguir entre microclinas desordenadas y ordenadas, cuyo origen se puede correlacionar con una dualidad en su evolución al estado sólido según un régimen genético estático y otro dinámico durante el enfriamiento. El régimen estático produce un re-equilibrado limitado porque la recristalización de regiones con mayor orden Si/Al es superficial. El ordenamiento Si/Al está localizado en las proximidades de las superficies con circulación acanalada de fluidos acuosos catalizadores de las transformaciones estructurales. El régimen dinámico es adaptativo y el re-equilibrado es extenso operando por recristalización global. Este comportamiento se explica por el flujo volumétrico de las moléculas de agua catalizadoras del re-equilibrado. La penetración parcial del agua a través de la estructura produce un régimen transicional entre los dos anteriores.

A new method for the geometrical and optical characterization of non-uniform thin isotropic dielectric films deposited onto a transparent substrate, has been developed. The algorithm is based on using the two envelopes of the optical reflection spectrum taken at normal incidence. The method allows determining the average thickness and the refractive index of the films with accuracies better than 1 %. The formulation is not only valid in the case of wedge-shaped thin films, but also for films showing a significant surface roughness. In the latter, the amplitude of the surface roughness can be estimated. Amorphous As40S60 thin films have been deposited by spin coating onto glass substrates, from a solution of the bulk material in n-propylamine. Indications of the surface roughness in these films were found from total reflectance measurements (specular + diffuse), by using a integrating sphere, and also from mechanical measurements, by using a profilometer. The latter technique provided a value for the average surface roughness of 20 ± 4 nm, which is in excellent agreement with that optically determined value of 17.4 ± 0.4 nm.Se ha desarrollado un nuevo método para la caracterización geométrica y óptica de láminas dieléctricas isótropas con espesor variable, depositadas sobre un substrato transparente. Este método está basado en el uso de las dos envolventes de los espectros de reflexión, obtenidos en incidencia normal, y permite determinar el espesor medio y el índice de refracción de estas láminas, con precisiones mejores que el 1 %. La formulación contempla la posibilidad de ser aplicable, no sólo en el caso de láminas cuyo espesor varíe linealmente a lo largo del área cubierta por el haz luminoso de medida, sino en aquellas que presenten un rugosidad significativa en su superficie y, en tal caso, permite determinar la amplitud de la rugosidad promedio. Así, se han preparado láminas delgadas amorfas de composición química As40S60 mediante el centrifugado de una disolución de este compuesto calcogenuro en n-propilamina. La rugosidad superficial de estas láminas se ha puesto de manifiesto a partir de las medidas de la reflectancia total (especular + difusa), haciendo uso de una esfera integradora, así como a través de medidas mecánicas de espesores, usando un perfilómetro. Esta última técnica proporcionó un valor para la amplitud media de la rugosidad de 20 ± 4 nm. El acuerdo entre este valor y el calculado mediante el presente método de caracterización óptica, 17.4 ± 0.4 nm, es excelente.

Background: The importance of attitudes in learning is gaining relevance among researchers and teachers and yet little research has examined students' attitudes specifically in relation to geology. Purpose: The aim of this study was to examine students' attitudes towards geology and with respect to other sciences, as well as to determine the key factors that influence these attitudes. Sample: A sample of 1.641 students in their fourth year of secondary education from five autonomous communities in Spain participated in this study. Design and Methods: The research was conducted using a previously validated survey, specifically designed to answer the research questions of the study. Results: The findings revealed that participants generally demonstrate more negative attitudes towards geology than with respect to other sciences. Although they do not consider it a difficult subject, they find it boring and of little interest. Demographic factors, school type or gender do not explain these attitudes: academic aspects seem to be the key to reversing this situation. Conclusions: The findings of the present study provide some insights into the teaching of geology. For instance, geology programmes need to focus on topics in which students are interested in, and also on establishing connections between geological contents taught in the classroom and real life.