1,721,152 research outputs found
Spin waves in configurational antiferromagnetic states: transitions to and from ferromagnetic states
No full textWe study collective spin waves in transversally magnetized chains of thin elliptical dots initially arranged into an antiferromagnetic (AF) configuration. The dispersion relations of the SW as well as the corresponding magnetization precession profiles (eigenvectors) are computed with the dynamical matrix method [1]. We report the peculiar features of AF optical and acoustical spin modes within the effective wavevector model [2], which has been adapted to the present geometry. We investigate the effects of the application of a transverse external field, leading
the system from a perfect AF configuration to the ferromagnetic (FM) state, at a specific transition field. We discuss the mode localization and symmetry, and in particular, we focus on the AF soft mode, its symmetry and its relationship with the instability leading to AF-to-FM transition. We discuss the importance and potential application of the SW propagative properties suddenly changed at the switching from AF to FM. Finally, we present the calculations of spin dynamics concerning a FM-to-AF transition in a chain of ellipses with different width: in this case, the different shape anisotropy of the two ellipses results in different switching fields and hence in a field interval where the AF state is spontaneously attained. We show how this AF field interval can also be tuned by an effective uniaxial anisotropy of one out of two ellipses: this is indicative of any other source of anisotropy (like inverse-magnetostriction, particularly promising for voltage driven magnetic transitions in multiferroics): in this way, we investigate the AF-to-FM transition spin dynamics by varying the effective anisotropy constant of the material. Finally, we show and comment on thepeculiar and remarkable change of slope of the mode dispersion across the AF-to-FM transition, with its implications in the field of magnon-spintronics devices.
References: [1] L. Giovannini, F. Montoncello, and F. Nizzoli, Phys. Rev. B 75, 024416 (2007).
[2] F. Montoncello, S. Tacchi, L. Giovannini, M. Madami, G. Gubbiotti, G. Carlotti, E. Sirotkin, E. Ahmad, F. Y. Ogrin, and V. V. Kruglyak, Appl. Phys. Lett. 102, 202411 (2013)
Fostering the Use of ICT in Pedagogical Practices in Science Education
No full textThe FICTUP project (Fostering the Use of ICT in Pedagogical Practices), funded with the support of the Lifelong Learning Programme of the European Union, aims to (1) create innovative training materials that suggest concrete pedagogical activities using ICT, accompanied by a close tutoring process, and (2) test the impact of the material and the tutoring on novice teachers' use of ICT in the classroom.
The innovative training material, developed collaboratively by both experienced and novice teachers to ensure its accessibility, focuses on specific classroom activities that use ICT. Each case includes a detailed description of the activity (PDF file) and three short, pedagogical videos (ca. 2-6 minutes each) that describe the transversal ICT skills brought into play during the activity. During the first year of the project, nine cases were implemented, some of which focused explicitly on the use of ICT in science education. This paper presents a number of different sample applications, such as “Device – measurement – evaluation: Use of ICT in physics (Hungary)”, “Exploring growth factors: Applying inquiry learning in biology (Finland)”, and “GeoGebra software: Mathematics teaching (France)”.
The increased use of ICT has led to the introduction of new pedagogical approaches, including Resource Based Learning (RBL) where varied learning needs are supported by a wide range of ICT assets. Science subjects in particular are extremely amenable to the advantages offered by RBL and the associated ICT assets. The implementation of technology-supported collaborative inquiry allows teachers to design the educational setting as an integrated whole that provides students with relevant technological tools, directs them to collaborate effectively, and promotes epistemologically high-level and creative ways of working with knowledge
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
La valutazione di ricerche pedagogiche con “metodi misti” da parte dei referee: tra criteri di qualità e aspetti problematici
No full textNell’ambito del dibattito sulla valutazione della ricerca, il contributo si sofferma sul vaglio critico dei referee relativo a quel particolare tipo di ricerca empirica pedagogica in cui vengono utilizzati, in forma integrata, approcci e/o metodi di tipo quantitativo e qualitativo (mixed method research o mixed method). Questo anche al fine di sottolineare i rischi e l’amplificarsi dei problemi nella valutazione esterna della produttività scientifica dei ricercatori, in relazione alle metodologie e procedure di indagine utilizzate nei confronti di prodotti di ricerca educativa di tipo empirico e valutativa.
Dopo una contestualizzazione politico-istituzionale dei processi di sviluppo della ricerca pedagogica, il contributo illustrata la rilevanza che all’interno di essa stanno assumendo le indagini con i “metodi misti”. Le implicazioni problematiche di questo fenomeno per la valutazione degli esiti della ricerca sono rese evidenti mediante la ricostruzione delle principali voci del dibattito circa l’integrazione tra quantitativo e qualitativo e i criteri di qualità delle ricerche con approccio metodologico misto. Sono infine presentate alcune considerazioni che, alla luce del rilevante ruolo che rivestiranno i “metodi misti”, intendono contribuire alla elaborazione di uno specifico sistema di criteri di qualità di cui sono prefigurate anche possibili ricadute sul sistema generale della ricerca pedagogica
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
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