262 research outputs found
Innovación digital en el aula de matemáticas: desarrollo de materiales docentes como apoyo en la enseñanza
La propuesta que se presenta forma parte de un proyecto de innovación docente, vinculado al servicio de producción e innovación digital de la Universidad de Salamanca, desarrollado en el curso 2015-16. En la asignatura de Matemáticas, cuyos contenidos tratan sobre Geometría y su didáctica, se generaron vídeos teórico prácticos, centrados en el recurso didáctico de la papiroflexia
Spatial Modulation of linear and quadratic susceptibilities in Lithium Niobate crystals by using femtosecond laser pulses
In this work we present the spatial control of the linear susceptibility (χ1) in Lithium Niobate crystals by means of infrared (800 nm) femtosecond interaction. Diffraction gratings have been performed on the surface (relief) and inside (phase) of these samples by femtosecond laser writing. Also we have performed a spatial control of the quadratic susceptibility (χ 2 ) by direct writing of a pattern of ferroelectric domains on the surface of z cut substrates by using the second harmonic femtosecond pulses (400 nm). Finally, efficient photonic devices for second harmonic generation via quasi phase matching could be obtained following the experimental procedure presented in this work
Revisiting the Hubble sequence in the SDSS DR7 spectroscopic sample: a publicly available bayesian automated classification
We present an automated morphological classification in 4 types
(E,S0,Sab,Scd) of ~700.000 galaxies from the SDSS DR7 spectroscopic sample
based on support vector machines. The main new property of the classification
is that we associate to each galaxy a probability of being in the four
morphological classes instead of assigning a single class. The classification
is therefore better adapted to nature where we expect a continuos transition
between different morphological types. The algorithm is trained with a visual
classification and then compared to several independent visual classifications
including the Galaxy Zoo first release catalog. We find a very good correlation
between the automated classification and classical visual ones. The compiled
catalog is intended for use in different applications and can be downloaded at
http://gepicom04.obspm.fr/sdss_morphology/Morphology_2010.html and soon from
the CasJobs database.Comment: A&A in press, english corrections from language editor adde
Diagnosis of stoneware pathology placed on bonded façade
Esta investigación analiza las causas del desprendimiento de un revestimiento de gres porcelánico colocado en fachada. En el momento de abordar este trabajo comprobamos que hay métodos normalizados para la determinación de las características de los adhesivos para las baldosas cerámicas y de las propias baldosas, pero en ambos casos, son métodos a aplicar durante el proceso de fabricación. No existen métodos normalizados para la determinación de las características de aplacados en servicio, cuestión que aborda este trabajo. Las técnicas de diagnosis empleadas han consistido en la comprobación de la capacidad de adherencia del adhesivo, la localización de juntas de movimiento, el análisis de las juntas de colocación y la detección de anclajes mecánicos ocultos.
Finalmente, los resultados obtenidos tras la aplicación de dicha metodología para el análisis de la patología han permitido establecer las causas que han originado los daños, proponiéndose como método de diagnosis del desprendimiento de un aplacado cerámico en servicio.This research examines the causes of the detachment of stoneware placed on façade cladding. In dealing with this work we see that there are standard methods for the determination of the characteristics of adhesives for ceramic tiles and own tiles, but in both cases, the methods are to be applied during the manufacturing process. There are no standard methods for the determination of the characteristics of facings in service, which deals with this work. Employed diagnosis techniques have consisted of checking the capacity of adhesion of adhesive, the location of movement joints, joints of positioning analysis and detection of hidden mechanical anchors.
Finally, the results obtained after the application of this methodology to the analysis of Pathology have allowed establishing the causes that have given rise to the damage; we propose a method of diagnosis of the evolution of a ceramic covering
Evaluating transdisciplinary science to open research-implementation spaces in European social-ecological systems
Researchers in multiple, related fields that address complex social and environmental challenges, have shown ongoing enthusiasm for applying transdisciplinary social-ecological systems (SES) research to promote sustainability. However, few studies have evaluated the effectiveness of SES approach, assessed its achievements, and identified challenges to its implementation toward knowledge production for environmental conservation.
We report the results of a qualitative, participatory evaluation of several SES projects across Europe using an evaluation methodology tailored to transdisciplinary projects. We conducted 66 stakeholder interviews at four designated Long-Term Socio-ecological Research (LTSER) platforms – Danube Delta and Braila Island (Romania); Cairngorms (Scotland); and Doñana (Spain). Using qualitative analysis, we synthesized data from interviews and then returned to the sites to present findings to stakeholders in focus group discussions in order to incorporate their feedback into conclusions.
We conclude that although particular scientists at each platform have taken on entrepreneurial roles to operationalize transdisciplinary science, a business-as-usual attitude tends to dominate institutions, limiting meaningful progress toward transdisciplinary objectives, including: integration of social science research, giving non-researcher stakeholders a more meaningful role in advancing relevant research, and improving knowledge exchange among different stakeholder groups, among other issues. While we found that all the components of transdisciplinary SES research exist at the sites, there is no overarching strategy to link long-term planning and funding, knowledge integration, and priority-setting with stakeholders to ensure the relevance of research for policy and practice. We conclude with reflections about implementing our evaluation methodology, and a call for periodic, participatory evaluation into the future
Application of the PCA to guided ultrasonic waves to evaluate tensile stress in a solid rod
Postprint (author's final draft
Ionized gas kinematics of galaxies in the CALIFA survey : I. Velocity fields, kinematic parameters of the dominant component, and presence of kinematically distinct gaseous systems
J.M.A. acknowledges support from the European Research Council Starting Grant (SEDmorph; P.I. V. Wild). Date of Acceptance: 01/08/2014Context. Ionized gas kinematics provide important clues to the dynamical structure of galaxies and hold constraints to the processes driving their evolution. Aims. The motivation of this work is to provide an overall characterization of the kinematic behavior of the ionized gas of the galaxies included in the Calar Alto Legacy Integral field Area (CALIFA), offering kinematic clues to potential users of the CALIFA survey for including kinematical criteria in their selection of targets for specific studies. From the first 200 galaxies observed by CALIFA survey in its two configurations, we present the two-dimensional kinematic view of the 177 galaxies satisfaying a gas content/detection threshold. Methods. After removing the stellar contribution, we used the cross-correlation technique to obtain the radial velocity of the dominant gaseous component for each spectrum in the CALIFA data cubes for different emission lines (namely, [O ii] λλ3726,3729, [O iii] λλ4959,5007, Hα+[N ii] λλ6548,6584, and [SII]λλ6716,6730). The main kinematic parameters measured on the plane of the sky were directly derived from the radial velocities with no assumptions on the internal prevailing motions. Evidence of the presence of several gaseous components with different kinematics were detected by using [O iii] λλ4959,5007 emission line profiles. Results. At the velocity resolution of CALIFA, most objects in the sample show regular velocity fields, although the ionized-gas kinematics are rarely consistent with simple coplanar circular motions. Thirty-five percent of the objects present evidence of a displacement between the photometric and kinematic centers larger than the original spaxel radii. Only 17% of the objects in the sample exhibit kinematic lopsidedness when comparing receding and approaching sides of the velocity fields, but most of them are interacting galaxies exhibiting nuclear activity (AGN or LINER). Early-type (E+S0) galaxies in the sample present clear photometric-kinematic misaligments. There is evidence of asymmetries in the emission line profiles in 117 out of the 177 analyzed galaxies, suggesting the presence of kinematically distinct gaseous components located at different distances from the optical nucleus. The kinematic decoupling between the dominant and secondary component/s suggested by the observed asymmetries in the profiles can be characterized by a limited set of parameters. Conclusions. This work constitutes the first determination of the ionized gas kinematics of the galaxies observed in the CALIFA survey. The derived velocity fields, the reported kinematic distortions/peculiarities and the identification of the presence of several gaseous components in different regions of the objects might be used as additional criteria for selecting galaxies for specific studies.Publisher PDFPeer reviewe
Caracterización química, térmica y viscosa de oleínas ácidas de girasol alto oleico y orujo de oliva y estólidos derivados
This work deals with the chemical, thermal and viscous characterization of a variety of estolides, prepared from higholeic sunflower and olive pomace acid oils, using different acid-catalyzed synthesis protocols and reaction times. Estolides with weight-average molecular weights between 1.7 and 3.4 times higher than the original acid oils were obtained. The molecular weight of the estolides was higher when using the sulphuric acid-catalyzed method and a reaction time of 3-6 h. Estolides presented higher freezing temperatures than acid oils. In general, viscosity values are related to estolide molecular weight. Significant increments in viscosities were found in comparison with acid oils. Maximum viscosity values were obtained for estolides prepared using the sulphuric acidcatalyzed method. The largest viscosity increments in olive pomace acid oil-derived estolides were observed during the first 6 hours of reaction, due to an increase in the molecular weight; longer reaction times yielded adverse results. The temperature dependence of viscosity for all estolides studied is significantly larger than for the original acid oils.Este trabajo presenta la caracterización química, térmica y viscosa de estólidos preparados a partir de oleínas ácidas de girasol alto-oleico y de orujo de oliva, utilizando diferentes métodos catalizados por ácidos y diferentes tiempos de reacción. Se obtuvieron estólidos con pesos moleculares promedios en peso entre 1,7 y 3,4 veces más altos que las oleínas de origen. El peso molecular de los estólidos aumenta cuando se utiliza el método catalizado por ácido sulfúrico y un tiempo de reacción de 3-6 h. Los estólidos obtenidos presentan temperaturas de congelación más altas que las oleínas. En general, los valores de viscosidad están relacionados con el peso molecular del estólido. Se encontraron incrementos significativos de viscosidad en comparación con las oleínas. Los valores máximos de viscosidad se obtuvieron para los estólidos preparados con el método catalizado por ácido sulfúrico. En los estólidos derivados de oleína de orujo de oliva se observaron los mayores incrementos de viscosidad durante las 6 primeras horas de reacción, debido al mayor aumento en el peso molecular. Tiempos más largos de reacción dan lugar a resultados desfavorables. La dependencia de la viscosidad con la temperatura de todos los estólidos es más importante que en las oleínas de partida
Bar pattern speeds in CALIFA galaxies: I. Fast bars across the Hubble sequence
The bar pattern speed () is defined as the rotational
frequency of the bar, and it determines the bar dynamics. Several methods have
been proposed for measuring . The non-parametric method
proposed by Tremaine \& Weinberg (1984; TW) and based on stellar kinematics is
the most accurate. This method has been applied so far to 17 galaxies, most of
them SB0 and SBa types. We have applied the TW method to a new sample of 15
strong and bright barred galaxies, spanning a wide range of morphological types
from SB0 to SBbc. Combining our analysis with previous studies, we investigate
32 barred galaxies with their pattern speed measured by the TW method. The
resulting total sample of barred galaxies allows us to study the dependence of
on galaxy properties, such as the Hubble type. We measured
using the TW method on the stellar velocity maps provided by
the integral-field spectroscopy data from the CALIFA survey. Integral-field
data solve the problems that long-slit data present when applying the TW
method, resulting in the determination of more accurate . In
addition, we have also derived the ratio of the corotation radius to
the bar length of the galaxies. According to this parameter, bars can be
classified as fast ( \cal{R}\%\cal{R}$ and the galaxy morphological
type. Our results indicate that independent of the Hubble type, bars have been
formed and then evolve as fast rotators. This observational result will
constrain the scenarios of formation and evolution of bars proposed by
numerical simulations.Comment: 17 pages, 10 figures, accepted for publication in A&
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