1,721,113 research outputs found
Determination of the elastic moduli and residual stresses of freestanding Au-TiW bilayer thin films by nanoindentation
Full text linkIn this paper, we present a detailed mechanical characterization of freestanding bilayer (Au-TiW) micro-cantilevers and double clamped beams, for applications as Radio Frequency (RF)-switches Micro-Electromechanical Systems (MEMS). The testing structures have been characterized by an optical profilometer and Scanning Electron Microscopy (SEM) equipped with Energy Dispersive X-ray Spectroscopy (EDS), in order to acquire information about their geometries, composition, and the gap between the substrate underneath. Then, the micro-beams are deflected by using a specifically designed nanoindentation procedure based dynamic stiffness measurement during bending in order to extract the elastic modulus and the residual stresses of both layers. Firstly, the classic beam theory has been implemented for bilayer cantilevers enabling the extraction of elastic moduli. Then, residual stresses are estimated by deflecting double clamped beams, while implementing new analytical models for a bilayer system. The obtained elastic moduli are consistent with the average ones obtained for a single layer micro-cantilever and with nanoindentation results for TiW and Au homogeneous films. The residual stresses are in agreement with the values obtained from the double slot Focused Ion Beam (FIB) and Digital Image Correlation (DIC) procedure, providing an alternative and portable way for the assessment of residual stresses on composite double clamped micro-beams
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
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
In situ SEM mechanical characterization of advanced metallic films: recent & future developments @ LSPM
No full textInternational audienc
Boosting mechanical properties of metallic thin films through advanced nanoengineered design strategies
No full textInternational audienceThe current trend toward miniaturization in devices components in key technologies such as microelectronics, energy production, sensors and wear protection requires the development of high-performance thin films with superior mechanical properties combining mutually excluding mechanical properties such as high yield strength and ductility. Achieving such performance, relies on leveraging microstructure-induced mechanical properties, requiring the precise control of film’s microstructure, atomic composition, grain size and thickness based on nanoengineering design concepts. Here, I will present recent results for several class of advanced thin film materials including nanostructured metallic glasses (ZrCu, ZrCuAl)[1, 2] high entropy alloys (CoCuCrFeNi) and nanolaminates (fully amorphous, amorphous/crystalline)[3, 4], highlighting how the control of the microstructure affect the and micro-scale mechanical behavior and enable ultimate mechanical properties.Among the main results, I will show the fabrication of fully amorphous Zr24Cu76/Zr61Cu39 nanolaminates by magnetron sputtering with controlled nanoscale periodicity (Λ, down to 5 nm), local chemistry and glass-glass interfaces [3]. I will show how the shear band instability can be mitigated when Λ ≤ 50 nm, reaching remarkably large elastic/plastic deformation (16%) and yield strength (~2GPa) by micro-pillar compression [3]. Then, I will present the potential of Pulsed Laser Deposition (PLD) as a novel technique to synthetize nanostructured cluster-assembled ZrCu and CoCuCrFeNi films, reaching ultimate yield strength (>3 GPa) and ductility (>6 %) for ZrCu. Finally, I will focus on the synthesis of crystal/glass ultrafine nanolaminates by PLD[4] in which ∼4 nm Al (crystalline) separate 6 and 9 nm-thick Zr50Cu50 metallic glass nanolayers, showing high yield strength (3.4 GPa) in combination with enhanced elastoplastic deformation (>6%, in compression), while managing to effectively block the percolation of shear bands even at >15% deformation[4].Overall, I will show how fine microstructural control in metallic thin films is an effective strategy to tailor their deformation behavior and boosting their mechanical properties with potential for industrial applications. [1] M. Ghidelli et al., Acta Mater. 213 (2021) 116955.[2] C. Poltronieri et al., Acta Mater. 258 (2023) 119226.[3] A. Brognara et al., Small Struct. (2024) 2400011.[4] F. Bignoli et al., ACS Appl. Mater. Inter. 16(27) (2024) 35686-35696
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