1,723,665 research outputs found
Mean atomic weight of LL5 chondrites: Siena, Hautes Fagnes and NWA 7915
No full textMean atomic weights Amean of Siena (LL5, fall 1794), Hautes Fagnes (LL5, S1, W1, find 1965) and NWA 7915 (LL5, S2, W3, find 2010) ordinary chondrites have been determined using literature data on chemical composition of the meteorites and using relationship between mean atomic weight and Fe/Si atomic ratio (Szurgot 2015). It was shown that NWA 7915 Amean = 22.80 is close to mean atomic weight of LL chondrites (Amean = 23.00), and is close to mean atomic weight of LL chondrite falls (Amean = 22.90, Szurgot 2015). NWA 7915’s Fe/Si atomic ratio (0.529) leads to Amean = 23.28 which is close to the value determined by bulk composition. This means that NWA 7915 belongs to LL5 chondrites, as previously classified (Brawata et al. 2014). Mean atomic weight Amean of Hautes Fagnes determined by bulk composition is between 23.11 and 23.35. Lower Amean value is close to Amean of LL chondrites, but higher value is the same as Amean of intermediate L/LL chondrites (23.34 for L/LL, Szurgot 2016). Hautes Fagnes Fe/Si atomic ratio and Amean(Fe/Si) are identical with those for NWA 7915 (Fe/Si = 0.529, Amean = 23.28). Amean data indicate that Hautes Fagnes can belong to LL5 chondrites, as previously classified (Vandeginste et al. 2012) or can be one of L/LL chondrites. Mean atomic weight of Siena meteorite is much higher than expected for LL chondrite. Siena’s bulk composition gives Amean = 24.47, and Amean(Fe/Si) dependence gives Amean = 24.45 (Fe/Si = 0.7345). Using dependence between mean atomic weight and grain density (Szurgot 2015) leads to Amean = 23.24 (dgr = 3.46 g/cm3, Macke 2010), and using dependence between Amean and magnetic susceptibility (Szurgot 2016) gives Amean = 23.53±0.13 (logc = 4.65±0.09, Macke 2010). Bulk composition and Fe/Si ratio indicate that Siena has the same Amean as intermediate H/L chondrites, for which Amean = 24.3 (Szurgot 2016). Grain density indicates rather L/LL intermediate group for Siena, and magnetic susceptibility indicates intermediate L/LL or L chondrites (23.34 for L/LL, and 23.67 for L, Szurgot 2016). Mean atomic number Zmean, and Amean/Zmean ratio of the three meteorites have been also determined. Siena’s Zmean = 12.104, Hautes Fagnes Zmean = 11.445–11.562, and NWA 7915’s Zmean = 11.293. Amean/Zmean ratios are: 2.022 for Siena, 2.019–2.020 for Hautes Fagnes, and 2.019 for NWA 7915
[Midland Valley Railroad for Kansas, Oklahoma & Gulf Rwy., Engine Drawing Card, Sketch No. 7915]
No full textThis engine drawing card was created for Midland Valley Railroad Company, Class 14-48 1/4F. Section N-14 1/4 F. Sketch 7915. Copy Spec. C-9763
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
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
Cartografía geológica hiperespectral en Maktesh_Ramon (Israel) con el espectrometro aeroportado DAIS 7915
No full textEl espectróimetro DAIS 7915 registro datos sobre el valle de Maktesh Ramón (Israel) en una región mediterránea árida. Los afloramientos visibles en superficie son predominantemente carbonatos, lo que pone a prueba la capacidad cartográfica de un sensor en el visible, infrarrojo cercano y infrarrojo térmico como el DAIS 7915. EI infrarrojo térmico, sensible a la topografía, se ha utilizado como documento base en fotogeología convencional, y resalta la influencia de la textura de los materiales y la rugosidad de las superficies en la respuesta espectral. El análisis de componentes principales y las transformadas de fracciones de ruido mínimo orientaron los criterios a utilizar en la selección de litologías a cartografiar. El uso de espectros de campo en tratamientos cartográficos orientados al análisis de imágenes hiperespectrales ha puesto de manifiesto la importancia de los minerales de alteración por meteorización en la respuesta espectral de los afloramientos rocosos
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
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