1,720,956 research outputs found
High-Performance Flexible Ultraviolet Photodetectors Based on Facilely Synthesized Ecofriendly ZnAl:LDH Nanosheets
No full textRecent studies have focused on the development of efficient, flexible, and highly sensitive ultraviolet photodetectors (UV PDs) with various wide band-gap materials. In the present study, the application of environmentally friendly zinc-aluminum layered double hydroxide (ZnAl-CO3:LDH) is demonstrated for a high-performance, flexible UV PD. The vertically oriented ZnAl:LDH nanosheets (ZnAl:LDH Ns) are facilely synthesized by dipping the sputtered 10 wt % aluminum-doped zinc oxide thin films in deionized water at room temperature. Without passivation, the UV PDs exhibit an exceptional light-to-dark current ratio of 104 and a responsivity of similar to 34.7 mA/W at a bias of 1 V. Moreover, the spectral responsivity and detectivity are enhanced to similar to 148.3 mA/W and 2.5 x 1012 Jones, respectively, by passivating the ZnAl:LDH Ns with polydimethylsiloxane (PDMS), thus making the device suitable for application in UV detectors. In addition, the ambient atmosphere effect on PD performance, which elucidates the clear understanding of the PD working mechanism, is also investigated. The passivation of the Ns by PDMS also helps to enhance the mechanical robustness and long-term stability of the PD. The methodology demonstrated herein highlights the potential of the ZnAl:LDH material in realizing the next generation of flexible
Harnessing Flexoelectric and Piezoelectric Effects for Self-Charging Power Systems
No full textStretchable mechanical energy harvesters are in high demand as sustainable power sources and self-powered systems for wearable electronics and biomedical devices. In this study, a stretchable flexoelectric-piezoelectric nanogenerator (FPENG) composed of a zinc-aluminum layered double hydroxide nanosheets-ZnO nanorods (ZnAl:LDH NSs-ZnO NRs) heterostructure is developed. The coupling of the flexoelectric effect of ZnAl:LDH NSs and the piezoelectric effect of ZnO NRs enhances the output performance of the FPENG. The FPENG generates an open-circuit voltage (V oc) of 41.5 V, a short-circuit current density (J sc) of 4.57 mu A/cm2, and a maximum power density of 68.2 mu W/cm2 with good mechanical durability, while the device under stretching at 60% strain generates a V oc of 1.85 V and J sc of 0.09 mu A/cm2. The energy generated from the FPENG is stored in a Li-ion battery, demonstrating a self-charging power unit. These findings present a simple method to develop FPENGs with enhanced performance by coupling flexoelectric and piezoelectric effects for wearable devices.
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Synergistic contribution of flexoelectricity and piezoelectricity towards a stretchable robust nanogenerator for wearable electronics
No full textThe fabrication of a high-performance piezoelectric nanogenerator (PENG) with high stretchability and durability is desirable for the next-generation of stretchable and wearable electronics. Herein, an eco-friendly and stretchable flexoelectricity-enhanced piezoelectric nanogenerator (F-PENG) based on zinc-aluminum layered double hydroxide nanosheets (ZnAl:LDH Ns)-ZnO heterostructure is demonstrated on stretchable polydimethylsiloxane (PDMS) substrates. The vertically-oriented eco-friendly ZnAl:LDH Ns are facilely synthesized by dipping the 10 wt% aluminum-doped zinc oxide (AZO) thin films in deionized (DI) water at room temperature. The enhanced output performance of the F-PENG is demonstrated under tapping, bending, and stretching modes, and is attributed to the synergistic flexoelectric and piezoelectric effects. The achieved maximum output power density of F-PENG under tapping is similar to 2.7 mu W/cm(2). The pressure-sensing capability of the F-PENG is demonstrated by the generated outputs under the three applied modes. In addition, the biomechanical energy harvesting capability of the F-PENG is demonstrated by subjecting it to various biomechanical motions. The FPENG exhibits an excellent mechanical durability in all three modes of operation. The present study not only paves the way towards the facile fabrication of stretchable and high-performance F-PENGs with combined flexoelectric and piezoelectric effects, but also validates a wide range of applications in the next generation of stretchable and wearable electronics.
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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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