1,721,345 research outputs found
La importancia del desarrollo de la competencia comunicativa intercultural con alumnos marroquíes en el contexto de la enseñanza de ELE
No full textPaz Rodriguez, Jesus; director de proyecto: Muñoz Sanz, Carmen2021-2022Máster Universitario en Enseñanza de Español como Lengua ExtranjeraFacultad de Estudios Sociales y Lenguas Aplicada
Palaeomagnetism and magnetic fabric of the Roraima sandstone and basement rocks of the Santa Elena region, south eastern Venezuela
No full textA study of the palaeomagnetism and magnetic fabric of rocks from the Roraima Group and the Cuchivero Province of the Guayana shield of southeastern Venezuela has been carried out. A total of 232 samples (361 specimens) were collected from the Uairen, Cuquenan and Uaimapue sedimentary formations of the Roraima Group and 29 samples (38 specimens) from the Cuchivero Province. The characteristic magnetisations of each sample were analyzed by linear regression analysis of Zijderveld vector diagrams and/or vector average, using data obtained from incremental a.f. and thermal demagnetization. The eccentricity method of Engebretson and Beck (1978) has been applied to estimate, and aid interpretation of, the elongation direction of the palaeomagnetic data set for the Uairen formation. Rotations suggested by Bullard et al. (1965), and Onstott and Hargraves (1981) have been applied to the palaeomagnetic pole positions obtained from this study, in order to evaluate their possible significance in the context of published Precambrian continental reconstruction. Two components of the magnetization were generally isolated by incremental demagnetization in samples from the Cuchivero Province, the Uairen and the Uaimapue formations, while samples from the Cuquenan formation showed only a single component of magnetization. The more stable component from the Cichivero rocks yields a palaeomagnetic pole position which, when compared with the apparent polar wander curves of McElhinny and McWilliams (1977), and Graterol and Hailwood (1981), indicates that the magnetization was probably acquired during the Pretransamazonian orogenesis (2600-2100 m.y.). The less-stable component is believed to have been acquired during the low grade Nickorie metamorphic event (1300-1100 m.y.). The pole positions calculated from both the more-stable and less-stable components of the Uairen formation corresponds approximately with the 2000 m.y. point on the apparent polar wander path of Onstott and Hargraves (1981). This suggests that both components of magnetization may have been acquired at about this time. The single component of magnetization identified in samples from the Cuquenan formation suggests a possible age of magnetization of about 1900 m.y. The magnetic fabric results indicate a dominant east-southeasterly alignment in grain long axes in the sediments of the Uairen formation, which may be related to sediment transport in this direction. (D67494/86)</p
Development of antibacterial medical devices by coupling 3D printing and drug repurposing
Get PDFDevice-associated infections are a major healthcare challenge as they are responsible for high disease burden in critically ill patients. In this doctoral thesis project, we have developed drug-eluting antibacterial catheters to prevent catheter-related infections. Niclosamide (NIC), originally an antiparasitic drug with anti-staphylococcal activity, was incorporated into the polymeric matrix of thermoplastic polyurethane (TPU) via solvent casting, and catheters were fabricated using hot-melt extrusion technology. Similarly, based on Ink jet printing technology, polymeric inks containing niclosamide, were developed to coat polyethylene catheters. Both antibacterial approaches will release niclosamide in a controlled and sustained way, thus exerting its antimicrobial effect leading to the prevention device-associated infections. The mechanical and physicochemical properties of the devices ere studied. Moreover, the antibacterial efficacy of NIC-loaded catheters was validated with an in vivo biomaterial-associated infection model using a methicillin-susceptible and methicillin-resistant strain of S. aureus. The released NIC from the produced catheters reduced bacterial colonization of the catheter as well as of the surrounding tissue. In summary, the NIC-releasing catheters prevented implant colonization and reduced the bacterial colonization of peri-catheter tissue by methicillin sensitive as well as resistant S. aureus in a biomaterial-associated infection mouse model and has good prospects for preclinical development
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Modelación computacional de la turbulencia en la cavidad de un cauce mediante una geometría cuadrada
No full textLa presencia de zonas muertas en cauces receptores afecta significativamente a las características del transporte de masa en el mismo. En un río, las zonas muertas pueden aparecer como consecuencia de irregularidades geométricas en los taludes laterales o en el fondo; o incluso favorecer la formación de campos similares a los que se presentan en estructuras más complejas como los diques.
Cuando se analizan los procesos de dispersión, las citadas zonas muertas producen una diferencia entre las curvas de concentración medidas y analizadas mediante los modelos clásicos unidimensionales de la ecuación de la advección-difusión con plumas de dispersión con frentes de avance pronunciados y colas alargadas. En una zona muerta la velocidad media en la dirección principal del flujo es esencialmente nula y el mecanismo principal de transporte es la turbulencia transversal, la cual controla los procesos de intercambio de soluto con el flujo en el cauce principal. Por ello, el conocimiento del perfil de velocidades y los coeficientes de intercambio en la sección de interfaz entre la zona muerta y el cauce principal es indicativo de la capacidad de transporte a través de la entrada a la misma (Uijttewaal, 2005; Weitbrecht et al., 2008). En cauces con aguas poco profundas, las propiedades de este tipo de flujo combinado con estructuras eminientemente unidimensonales dan lugar a un grado importante de anisotropía en la turbulencia.
El objetivo de esta contribución es la presentación de los resultados de la comparación entre las capacidades de modelación de varios programas comerciales para análisis de los flujos alrededor y dentro de una geometría simplificada que represente el flujo en cauces receptores naturales en este tipo de zonas muertas. Para ello, se ha realizado una modelación computacional bidimensional simulando un régimen permanente de velocidad en un cauce principal con una cavidad cuadrada. Asimismo, los resultados de estas modelaciones se han comparado con las mediciones que para la misma geometría se presentan en la bibliografía propuesta por Muto et al. (2000).
Para representar la capacidad de intercambio a través de la interfaz de la zona muerta con el cauce, se evalúa el perfil de velocidades en el interior de la cavidad y en la línea de intercambio entre el flujo principal y la cavidad. Para ello se propone el uso de códigos comerciales: Multiphysics 3.5TM, Fluent 6.3TM y STAR CCM+ 3.06TM
Shaping the global: Theory and methods for exploring the production of globalization with educational media
No full textDispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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