Well-posedness of the Kolmogorov two-equation model of turbulence in optimal Sobolev spaces

In this paper, we study the well-posedness of the Kolmogorov two-equation model of turbulence in a periodic domain Td, for space dimensions d = 2,3. We admit the average turbulent kinetic energy k to vanish in part of the domain, i.e. we consider the case k ≥ 0; in this situation, the parabolic structure of the equations becomes degenerate. For this system, we prove a local well-posedness result in Sobolev spaces Hs, for any s > 1+d/2. We expect this regularity to be optimal, due to the degeneracy of the system when k ≈ 0. We also prove a continuation criterion and provide a lower bound for the lifespan of the solutions. The proof of the results is based on Littlewood- Paley analysis and paradifferential calculus on the torus, together with a precise commutator decomposition of the non-linear terms involved in the computations

Boron concentration profiling by high angle annular dark field-scanning transmission electron microscopy in homoepitaxial delta-doped diamond layers

To develop further diamond related devices, the concentration and spatial location of dopants should be controlled down to the nanometer scale. Scanning transmission electron microscopy using the high angle annular dark field mode is shown to be sensitive to boron doping in diamond epilayers. An analytical procedure is described, whereby local boron concentrations above 1020 cm-3 were quantitatively derived down to nanometer resolution from the signal dependence on thickness and boron content. Experimental boron local doping profiles measured on diamond p-/p++/p- multilayers are compared to macroscopic profiles obtained by secondary ion mass spectrometry, avoiding reported artefacts.4 page

Utilización de Lecturas Graduadas de Inglés y Francés en BUP y COU

Se exponen sucintamente algunas experiencias en el uso de lecturas graduadas en las clases de inglés y francés, empezando por los criterios de selección, la elección, las distintas actividades dentro y fuera del aula para que el alumno desarrolle las\ud distintas habilidades lingüísticas y algunas sugerencias para la explotación.\ud Seguidamente, desde una perspectiva eminentemente práctica, utilizando\ud material auténtico, se procederá al desarrollo de un texto seleccionado para uno de los niveles de B.U.P. de inglés

Electric Switching of the Charge-Density-Wave and Normal Metallic Phases in Tantalum Disulfide Thin-Film Devices

We report on switching among three charge-density-wave phases - commensurate, nearly commensurate, incommensurate - and the high-temperature normal metallic phase in thin-film 1T-TaS2 devices induced by application of an in-plane electric field. The electric switching among all phases has been achieved over a wide temperature range, from 77 K to 400 K. The low-frequency electronic noise spectroscopy has been used as an effective tool for monitoring the transitions, particularly the switching from the incommensurate charge-density-wave phase to the normal metal phase. The noise spectral density exhibits sharp increases at the phase transition points, which correspond to the step-like changes in resistivity. Assignment of the phases is consistent with low-field resistivity measurements over the temperature range from 77 K to 600 K. Analysis of the experimental data and calculations of heat dissipation suggest that Joule heating plays a dominant role in the electric-field induced transitions in the tested 1T-TaS2 devices on Si/SiO2 substrates. The possibility of electrical switching among four different phases of 1T-TaS2 is a promising step toward nanoscale device applications. The results also demonstrate the potential of noise spectroscopy for investigating and identifying phase transitions in materials.Comment: 32 pages, 7 figure

¿Enfermera o paciente? La mujer del enfermo alcohólico

Se presentan los resultados de un estudio exploratorio que busca descubrir los daños psicológicos que el alcoholismo del marido pueda provocar en su mujer o compañera. Asimismo, el estudio busca la posible influencia del alcoholismo del marido en la aparición de determinados tipos de caracteres, actitudes y conductas en el cónyuge. Se pasó una encuesta y se administró el cuestionario de los Cinco Grandes (Big Five Questionnaire) para examinar la personalidad de 60 enfermos alcohólicos y sus esposas. De acuerdo con los resultados de nuestro estudio exploratorio, la mujer del enfermo alcohólico crónico tiene mayor riesgo de presentar inestabilidad emocional, ansiedad, sentimiento de culpa, indefensión aprendida, reacciones psicosomáticas (gastritis), desconfianza ante la novedad, distanciamiento emocional, dependencia, déficit de habilidades sociales y poco interés por las experiencias sociales nuevas. De confirmarse estos resultados, las intervenciones en apoyo a las personas que conviven con enfermos alcohólicos crónicos deberían prestar atención a todos estos aspectos.Here we summarize the outcomes of an exploratory study which was trying to discover the psychological damages that the alcoholism of the husband provokes in his wife or companion. Likewise, the study was searching the existence of possibly relations between the alcoholism of her husband, and certain types of characters, attitudes and conducts of the wife. Using the Big Five Questionnaire, and a questionnaire ad hoc, we analyzed the personality profile of 60 alcoholic people and his wives. According to the results, the women who lives with and alcoholic is in a bigger risk of emotional and psychosomatic diseases, anxiety, learned helpness, and social inhibition. Programs that aim to support people who live with alcoholics may pay attention to these risks

Shifts in Growth Responses to Climate and Exceeded Drought-Vulnerability Thresholds Characterize Dieback in Two Mediterranean Deciduous Oaks

Drought stress has induced dieback episodes affecting many forest types and tree species worldwide. However, there is scarce information regarding drought-triggered growth decline and canopy dieback in Mediterranean deciduous oaks. These species face summer drought but have to form new foliage every spring which can make them vulnerable to hotter and drier conditions during that season. Here, we investigated two stands dominated byQuercus frainettoTen. andQuercus canariensisWilld. and situated in southern Italy and Spain, respectively, showing drought-induced dieback since the 2000s. We analyzed how radial growth and its responses to climate differed between non-declining (ND) and declining (D) trees, showing different crown defoliation and coexisting in each stand by: (i) characterizing growth variability and its responsiveness to climate and drought through time, and (ii) simulating growth responses to soil moisture and temperature thresholds using the Vaganov-Shashkin VS-lite model. Our results show how growth responsiveness to climate and drought was higher in D trees for both oak species. Growth has become increasingly limited by warmer-drier climate and decreasing soil moisture availability since the 1990s. These conditions preceded growth drops in D trees indicating they were more vulnerable to warming and aridification trends. Extremely warm and dry conditions during the early growing season trigger dieback. Changes in the seasonal timing of water limitations caused contrasting effects on long-term growth trends of D trees after the 1980s inQ. frainettoand during the 1990s inQ. canariensis. Using growth models allows identifying early-warning signals of vulnerability, which can be compared with shifts in the growth responses to warmer and drier conditions. Our approach facilitates establishing drought-vulnerability thresholds by combining growth models with field records of dieback