1,720,991 research outputs found
Nanotecnología : ¿evolución científico-tecnológica de pequeños riesgos?
Full text linkFil: Olmedo, Daniel G. Universidad de Buenos Aires. Facultad de Odontología; ArgentinaFil: Tasat, Deborah R. Universidad de Buenos Aires. Facultad de Odontología; ArgentinaFil: Cabrini, Rómulo L. Universidad de Buenos Aires. Facultad de Odontología; ArgentinaFil: Audebert, Fernando. Universidad de Buenos Aires. Facultad de Ingeniería; ArgentinaFil: Guglielmotti, María Beatriz. Universidad de Buenos Aires. Facultad de Odontología; ArgentinaLa nanotecnología es un campo de las ciencias aplicadas dedicado al control y manipulación de la materia a nivel de átomos y moléculas, en un rango comprendido entre uno y cien nanómetros. Permite la creación de materiales, dispositivos y sistemas mediante el control de la materia a esa escala. En el campo de la Odontología se han desarrollado bio-sensores altamente especializados, que permitirían la identificación de enfermedades en la saliva. En un futuro cercano será clave su uso en el diagnóstico de enfermedades de alto impacto como el cáncer de mama, ovario y páncreas, enfermedad de Alzheimer, SIDA, diabetes y osteoporosis
Yttria and Ceria Doped Zirconia Thin Films Grown by Pulsed Laser Deposition
Full text linkThe Yttria stabilized Zirconia (YSZ) is a standard electrolyte for solid oxide fuel cells (SOFCs), which are potential candidates for next generation portable and mobile power sources. YSZ electrolyte thin films having a cubic single phase allow reducing the SOFC operating temperature without diminishing the electrochemical power density. Films of 8 mol % Yttria stabilized Zirconia (8YSZ) and films with addition of 4 weight % Ceria (8YSZ + 4CeO2) were grown by pulsed laser deposition (PLD) technique using 8YSZ and 8YSZ + 4CeO2 targets and a Nd-YAG laser (355 nm). Films have been deposited on Soda-Calcia-Silica glass and Si(100) substrates at room temperature. The morphology and structural characteristics of the samples have been studied by means of X-ray diffraction and scanning electron microscopy. Films of a cubic-YSZ single phase with thickness in the range of 1-3 µm were grown on different substrates.Fil: Saporiti, F.. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Ingeniería Mecánica. Grupo de Materiales Avanzados; ArgentinaFil: Juarez, R. E.. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Ingeniería Mecánica. Grupo de Materiales Avanzados; ArgentinaFil: Audebert, Fernando Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería; Argentina. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Ingeniería Mecánica. Grupo de Materiales Avanzados; ArgentinaFil: Boudard, M.. Centre National de la Recherche Scientifique; Franci
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Variación del módulo de Young en función de la temperatura y tiempos de recocidos en vidrios metálicos de FeNiB
Full text linkLos vidrios metálicos se caracterizan por poseer altos valores de dureza y resistencia mecánica, con un módulo de Young entre un 20 % a un 50 % menor que el del correspondiente material cristalino. Tratamientos térmicos de recocidos en estos vidrios, conducen a reordenamientos atómicos en la estructura amorfa, llamados de relajación estructural, y a procesos de cristalización. Estos reordenamientos y transformaciones de fase producen en algunos casos fuertes cambios en las propiedades mecánicas. Sobre cintas de un vidrio metálico de Fe₄₄.₁Ni₃₈.₆B₁₇.₃ obtenidas con un equipo de Melt-Spinning, se realizaron tratamientos térmicos de recocido continuo e isotérmico y se efectuaron determinaciones del módulo de Young mediante la técnica de resonancia en flexión según modo libre-libre. Se observan las variaciones del módulo como consecuencia de la evolución estructural, en función de la temperatura y tiempos de recocidosFil: Moya, J.. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Física (UBA-FI). Grupo de Sólidos Amorfos. Buenos Aires. ArgentinaFil: Audebert, Fernando Enrique. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Física (UBA-FI). Grupo de Sólidos Amorfos. Buenos Aires. ArgentinaFil: Sirkin, Hugo Ricardo Mario. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Física (UBA-FI). Grupo de Sólidos Amorfos. Buenos Aires. Argentin
Variations on the Author
Full text link“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
Full text linkWe 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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
Extrusion Textures in Al, 6061 Alloy and 6061/SiCp Nanocomposites
Full text linkThe 6061 alloy matrix composites reinforced with 10wt% and 15wt% of SiC nanoparticles with an average diameter of ~500nm were hot extruded in strip shape from ball milled powders. The microstructures and textures of the hot extruded nanocomposites have been investigated by means of three dimensional orientation distribution functions and electron backscatter diffraction (EBSD) techniques. Pure Al and 6061 alloy extruded strips from atomised powders have been produced for comparison purposes. The results show that the non-deformable SiC particulates have a strong influence on the formation of extrusion textures in the matrix. Pure Al and 6061 alloy develop a typical β fibre texture after extrusion in strip shape. For 6061/SiCp nanocomposites, the intensities of major texture components decrease with increasing amount of SiC particles. The total intensities of Brass, Dillamore and S components have decreased by 19% for 6061/10wt%SiCp and 40% for 6061/15wt%SiCp composites when compared with the 6061 alloy. EBSD analysis on local grain orientations shows limited Al grain rotations in SiC rich zones, resulting in the decreased texture intensities.Fil: Jiang, X.. University of Oxford; Reino UnidoFil: Galano, Marina Lorena. University of Oxford; Reino Unido. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Audebert, Fernando Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long". Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnologías y Ciencias de la Ingeniería "Hilario Fernández Long"; Argentina. University of Oxford; Reino Unido. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Ingeniería Mecánica. Grupo de Materiales Avanzados; Argentin
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