1,720,957 research outputs found
Estudio sedimentológico y paleoambiental del carbonífero en la Quebrada de Las Lajas, Sierra Chica de Zonda, Provincia de San Juan
No full textLas sedimentitas neopaleozoicas aflorantes en la quebradade Las Lajas, se hallan ubicadas en el flanco oriental de la Sierra Chica de Zonda. Este sector pertenece ala proviencia geológica de Precordillera Oriental. Esta secuencia que forma parte del Grupo Paganzo, yaceen discordancia, o en contacto por falla, sobre calizascambro-ordovícicas que forman el núcleo de la sierra. La recubren sedimentitas terciarias del Grupo Calchaquícon leve discordancia angular (14°). En general se presentacomo una estructura homoclinal con rumbo N 10° quese inclina al E entre 10° y 20°. En el presente trabajo se realizó un estudio litofaciala partir del cual se determina el modelo tectosedimentarioque dió lugar a la formación de estos depósitos. Lo anterior fué apoyado con un estudio petrográficode las areniscas, utilizando análisis cuali y cuantitatiVOS. A partir de estos datos se han inferido característicasdel área fuente de los materiales integrantes desdelos puntos de vista: roca madre, tectonismo y clima imperantes al tiempo de su gestación. Asimismo, teniendo en cuenta estas conclusiones y relacionándolas con observaciones en áreas vecinas, se verifica la presencia del Arco de Zonda como elemento positivo para el Carbonífero superior.Fil: Bercowski, Felisa. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina
Estudio sedimentológico y paleoambiental del carbonífero en la Quebrada de Las Lajas, Sierra Chica de Zonda, Provincia de San Juan
Get PDFLas sedimentitas neopaleozoicas aflorantes en la quebradade Las Lajas, se hallan ubicadas en el flanco oriental de la Sierra Chica de Zonda. Este sector pertenece ala proviencia geológica de Precordillera Oriental. Esta secuencia que forma parte del Grupo Paganzo, yaceen discordancia, o en contacto por falla, sobre calizascambro-ordovícicas que forman el núcleo de la sierra. La recubren sedimentitas terciarias del Grupo Calchaquícon leve discordancia angular (14°). En general se presentacomo una estructura homoclinal con rumbo N 10° quese inclina al E entre 10° y 20°. En el presente trabajo se realizó un estudio litofaciala partir del cual se determina el modelo tectosedimentarioque dió lugar a la formación de estos depósitos. Lo anterior fué apoyado con un estudio petrográficode las areniscas, utilizando análisis cuali y cuantitatiVOS. A partir de estos datos se han inferido característicasdel área fuente de los materiales integrantes desdelos puntos de vista: roca madre, tectonismo y clima imperantes al tiempo de su gestación. Asimismo, teniendo en cuenta estas conclusiones y relacionándolas con observaciones en áreas vecinas, se verifica la presencia del Arco de Zonda como elemento positivo para el Carbonífero superior.Fil: Bercowski, Felisa. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina
Upper Carboniferous retroarc volcanism with submarine and subaerial facies at the western Gondwana margin of Argentina
Get PDFDuring Late Carboniferous times a continental magmatic arc developed at the western margin of Gondwana in South America, as several marine sedimentary basins were formed at the same time in the retroarc region. North of 33°S, at Cordón Agua del Jagüel, Precordillera of Mendoza, Argentina, a volcanic sequence crops out which was emplaced in a submarine environment with some subaerial exposures, and it is intercalated in marine sediments of Agua del Jagüel Formation, which fills of one of these retroarc basins. This paper presents, for the first time, a facies analyses together with geochemical and isotopic data of this volcanic suite, suggesting its deposition in an ensialic retroarc marine basin. The volcanic succession comprises debris flows with either sedimentary or volcanic fragments, base surge, resedimented massive and laminated dacitic-andesitic hyaloclastite, pillow lava, basic hyaloclastite and dacitic-andesitic lavas and hyaloclastite facies. Its composition is bimodal, either basaltic or dacitic-andesitic. The geochemistry data indicate a subalkaline, low K calk-alkaline and metaluminous affinity. The geochemistry of the basalts points to an origin of the magmas from a depleted mantle source with some crustal contamination. Conversely, the geochemistry of the dacites-andesites shows an important participation of both crustal components and subduction related fluids. A different magmatic source for the basalts than for the dacites-andesites is also supported by Sr and Nd isotopic initial ratios and Nd model ages. The characteristics of this magmatic suite suggest its emplacement in an extensional setting probably associated with the presence of a steepened subduction zone at this latitude during Upper Carboniferous times.Fil: Koukharsky, Magdalena Maria L.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires; ArgentinaFil: Kleiman, L.. Comisión Nacional de Energía Atómica; ArgentinaFil: Etcheverría, M.. Secretaría de Industria y Minería. Servicio Geológico Minero Argentino; ArgentinaFil: Quenardelle, Sonia Monica. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires; ArgentinaFil: Bercowski, Felisa. No especifica
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
Dispelling 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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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