1,721,110 research outputs found
Privateering and piracy in the Spanish American Revolutions
Full text linkThis dataset contains information on prize actions between potential prize vessels and private maritime predators (privateers and pirates) during the Spanish American Revolutions. The database and seven tables inform the following book: McCarthy, Matthew. Privateering, piracy and British policy in Spanish America, 1810-1830. Woodbridge: Boydell Press, 2013. ISBN: 978184383861
Privateering and piracy in the Spanish American Revolutions
Full text linkThis dataset contains information on prize actions between potential prize vessels and private maritime predators (privateers and pirates) during the Spanish American Revolutions. The database and seven tables inform the following book: McCarthy, Matthew. Privateering, piracy and British policy in Spanish America, 1810-1830. Woodbridge: Boydell Press, 2013. ISBN: 978184383861
Investigation of an all solid state synchronously pumped optical parametric oscillator
No full textSIGLEAvailable from British Library Document Supply Centre- DSC:DX181467 / BLDSC - British Library Document Supply CentreGBUnited Kingdo
Dynamic friction and wear in a planar-contact encapsulated microball bearing using an integrated microturbine
No full textThe demonstration and characterization of a novel planar-contact encapsulated microball bearing using a radial in-flow microturbine are presented. Stable operation of the air-driven silicon microturbine is shown for over 1 000 000 revolutions at speeds, pressure drops, and flow rates of up to 10 000 r/min, 0.45 lbf/in2, and 3.5 slm, respectively. Incorporation of a gas thrust plenum using a novel packaging scheme has enabled comprehensive spin-down friction characterization of the encapsulated microball bearing. An empirical power-law model for dynamic friction has been developed for speeds of 250-5000 r/min and loads of 10-50 mN, corresponding to torques of 0.0625-2.5 muNldrm and friction torque constants of 2.25-5.25 x 10[superscript -4] muNldrm/ r/min. The onset and effect of wear and wear debris have been studied, showing negligible wear in the load bearing surfaces for the operating conditions considered.U.S. Army Research Laboratory (Grant CA#W911NF-05-2-0026
A Microfabricated Spiral-Groove Turbopump Supported on Microball Bearings
No full textThe development of a microfabricated turbopump that is capable of delivering liquid fuel with the flow rates and pressures required for portable power generation is reported. The device is composed of a spiral-groove viscous pump driven by a radial in-flow microturbine and supported using a newly developed encapsulated microball bearing. A planar-contact bearing raceway is employed using 285-??m -diameter 440C stainless steel microballs. A modification to the raceway geometry, as compared to previous designs, has enabled repeatable operation of the microturbine at speeds up to 87 000 r/min, showing negligible variations in performance for over 6 h and 3.8 million revolutions. Pumping has been demonstrated with water as the working fluid for flow rates of 10-80 mL/h and pressures rises of up to 8.2 kPa. This is the first application to incorporate an encapsulated microball bearing support mechanism, to achieve rotational speeds in excess of 50 000 r/min using a contact bearing, and to demonstrate reliable operation of more than 1 million revolutions.U.S. Army Research Laboratory. Sensors and Electronics Devices Directorate. (Cooperative Agreement W911NF0520026
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
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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