1,720,957 research outputs found
MORPHOLOGY AND PIEZORESISTIVITY OF LEAD-FREE (TMSO)3Sn3xBi2(1-x)I9 HALIDE PEROVSKITE THIN FILMS INFLUENCED BY BISMUTH
Full text linkThe development of lead-free perovskite thin films with adjustable optoelectronic properties is a
highly discussed topic in materials science. In this study, we present the bending strain sensitivity
of a lead-free hybrid organic-inorganic monodimensional iodide (TMSO)3Sn3xBi2(1-x)I9 (0 ≤ x ≤
1), with TMSO representing trimethylsulfoxonium. As previously observed in monodimensional
haloplumbates, the insertion of Bi3+ results in the formation of vacant cation sites, which in turn
leads to the adjustable shrinkage of the unit cell along the a lattice axis.[1-3] Thin films, prepared
by spin coating on flexible ITO/PET supports, are then employed to assess the bending strain
sensitivity as a function of composition. The films produced with low amount or without Bi3+
show similar or worse piezoresistive properties than the ITO control, whereas when Bi3+ is the
predominant metal ion, the corresponding piezoresistive features are enhanced (Fig. 1). An
optimal composition is found in 75 % Bi, where the bandgap can be lowered down to 1.96 eV,
and the gauge factor improves by increasing the bending strain, up to 110 at 0.6% strains.[4] The
films were analyzed by AFM to explain the observed features in terms of surface morphology.
The microstructural and electrical properties after deformation were explored by SEM and EIS.
This study represents an initial step in designing a lead-free halide perovskite with unique
piezoresistive properties for bending sensors requiring sensitivity to small and high bending
angles, applicable in soft robotics and wearable electronics
Bismuth drives the morphology and piezoresistivity of lead-free (TMSO)3Sn3xBi2(1−x)I9 halide perovskite thin films
Full text linkThe design of lead-free perovskite thin films with tunable optoelectronic properties is a hot topic in materials science, since it might enable the discovery of interesting properties outside the extensively explored field of photovoltaic solar cells. Herein, we report on the bending strain sensitivity of a lead-free hybrid organic–inorganic monodimensional iodide (TMSO)3Sn3xBi2(1−x)I9 (0 ≤ x ≤ 1) showing complete miscibility of Bi3+ and Sn2+, with TMSO being trimethylsulfoxonium. As previously shown in monodimensional haloplumbates, vacant cation sites are formed upon Bi3+ insertion, which in turn lead to the tunable shrinkage of the unit cell along the a axis. The effective substitution of Bi3+ and Sn2+ and their chemical state are investigated with EXAFS/XANES. Notably, Bi3+ also lowers the bandgap from 2.75 eV to 1.96 eV. Thin films prepared by spin coating on flexible ITO/PET supports are then used to assess the bending strain sensitivity as a function of composition, reaching an optimal value of the gauge factor (about 110 at 0.6% strain) at the highest Bi3+ concentration. The observed features are explained in terms of the surface morphology of the films as probed by AFM, highlighting the role of Bi3+. The effects on microstructural and electrical features after strain are further investigated by SEM and EIS, underpinning the key role of microcracks and delamination for triggering the observed responsivity to bending strain
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
"Um longo, interminável abraço de Alma": Mário de Sá-Carneiro, Fernando Pessoa and the letters.
No full textreservedQuesta tesi esplora il rapporto tra Mário de Sá-Carneiro e Fernando Pessoa, prestando particolare attenzione al massiccio utilizzo della comunicazione epistolare. L' approfondimento si concentra sulla lettere scritte da Mário de Sá-Carneiro a Fernando Pessoa, fondamentali per comprendere pienamente la figura dell'autore, i suoi rapporti umani e le sue relative fragilità. Per farlo,è stato utilizzato il libro "Em ouro e alma : correspondência com Fernando Pessoa" edito da Ricardo Vasconcelos e Jerónimo Pizarro. Le lettere sono imprescindibili per tracciare il legame che unisce i due artisti, inquadrare il contesto storico-letterario e le peculiarità di Mário de Sá-Carneiro. Successivamente, attraverso la selezione di alcune lettere, sono state approfondite le tematiche più ricorrenti del carteggio. Il lavoro di tesi si conclude con un confronto tra i due autori e sul ruolo assunto da Pessoa dopo la morte del giovane amico.This dissertation explores the relationship between Mário de Sá-Carneiro and Fernando Pessoa, paying particular attention to the massive use of epistolary communication. The 'in-depth study focuses on the letters written by Mário de Sá-Carneiro to Fernando Pessoa, which are fundamental to fully understanding the figure of the author, his human relationships and his relative frailties. To do so,the book “Em ouro e alma : correspondência com Fernando Pessoa” edited by Ricardo Vasconcelos and Jerónimo Pizarro was used. The letters are indispensable to trace the bond that unites the two artists, frame the historical-literary context and the peculiarities of Mário de Sá-Carneiro. Subsequently, through the selection of some of the letters, the most recurrent themes of the correspondence were explored. The thesis work concludes with a comparison between the two authors and on the role assumed by Pessoa after the young friend's death
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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