1,721,095 research outputs found
Motion of water-immersed superparamagnetic microparticles on top of a topographically flat thin film substrate imprinted with engineered magnetic stripe domains of gradually increasing/decreasing stripe width and alternating head-to-head/tail-to-tail magnetization configuration
No full textThe controlled transport and fractionation of magnetic microparticles according to their structural and magnetic properties is of great importance for the realization of miniaturized Lab-on-a-chip devices, applicable, e.g., for medical point-of-care diagnostics. We designed a transport and pre-sorting system for superparamagnetic beads based on an engineered magnetic stray field landscape emerging from a magnetic stripe domain pattern inside an exchange-biased thin film system. The magnetic stripe domains were imprinted into the system via ion bombardment induced magnetic patterning. The pattern consists of stripe domains with gradually increasing and decreasing stripe width, periodically repeated across the whole substrate. Directed motion of superparamagnetic beads above the substrate inside a quiescent liquid (water) is induced by applying weak external magnetic field pulses, superposing the static magnetic stray field landscape. The beads are forced to perform a jumping motion with increasing/decreasing jump length owing to the arrangement of the underlying domain pattern. Our data shows a simultaneous fractionation of all particles into mobile and immobile units according to their magnetophoretic mobilities. The motion velocity of the particles is thereby a function of jump length (stripe domain width) and the magnitude of the external field pulses. Superparamagnetic beads of significantly different sizes can be spatially separated using a short sequence of constant field pulses.
Videos of the particle motion were recorded using high-speed cameras attached to an optical microscope. The water-dispersed particles were placed on top of the magnetically patterned substrate inside a microfluidic chamber and motion was initiated by applying periodically repeated magnetic field pulses (pulse lengths in the ms-range; pulse magnitudes in the mT-range) using orthogonally arranged Helmholtz coils. The videos were analyzed qualitatively and quantitatively (particle velocity) using a custom Python code.51485852443350169936137929236139616
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
Anwendung kryogener Kalorimeter für hoch aufgelöste Präzisions-Röntgenspektroskopie
Full text linkIm Rahmen dieser Arbeit wurde die in den letzten Jahren stetig weiterentwickelte Technologie der metallischen magnetischen Mikrokalorimeter für den Einsatz als Hochpräzisionsspektrometer in der Atomphysik vorbereitet. Diese Detektoren vereinen aufgrund ihres einzigartigen Funktionsprinzips Vorteile verschiedener konventioneller energiedispersiver Photonennachweistechnologien. Sie verbinden die breite spektrale Akzeptanz von Halbleiterdetektoren mit der hohen Auflösung von Kristallspektrometern und stellen damit ein ideales Werkzeug für die Vermessung atomphysikalischer Interaktion mit einem breiten Bereich von Photonenenergien dar. Um das volle Potential der Detektoren ausnutzen zu können, wird jedoch der Übergang von einer für die konventionellen Verfahren etablierten analogen auf eine digitale Signalanalyse benötigt. Daher wurde im Verlauf der Arbeit ein leistungsfähiges und umfangreiches Softwarepaket entwickelt, um die Daten mehrerer durchgeführter Experimente auswerten zu können. Zum einen wurden Röntgenübergänge von Barium und Eisen an der S-EBIT-I beobachtet und identifiziert. Zum anderen wurden am internen Gasjet-Target des ESR-Speicherrings der GSI sowohl die 1s-Lamb-Verschiebung von Xe53+ als auch die 2s-Lamb-Verschiebung von Xe89+ erfolgreich mit Mikrokalorimeterdetektoren vermessen. Es konnten sowohl auf technischer Ebene als auch konzeptionell für den Betrieb und das Messprozedere signifikante Verbesserungen erzielt werden, sodass metallische magnetische Mikrokalorimeter für zukünftige Hochpräszisionsexperimente der Atomphysik bereitstehen
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
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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