1,720,976 research outputs found
3D printed electrolyte-supported solid oxide cells based on Ytterbium-doped scandia-stabilized zirconia
Full text linkSolid oxide cells (SOC) are an efficient and cost-effective energy conversion technology able to operate reversibly in fuel cell and electrolysis mode. Electrolyte-supported SOC have been recently fabricated employing 3D printing to generate unique geometries with never-explored capabilities. However, the use of the state-of-the-art electrolyte based on yttria-stabilized zirconia limits the current performance of such printed devices due to a limited oxide-ion conductivity. In the last years, alternative electrolytes such as scandia-stabilized zirconia (ScSZ) became more popular to increase the performance of electrolyte-supported cells. In this work, stereolithography 3D printing of Ytterbium-doped ScSZ was developed to fabricate SOC with planar and corrugated architectures. Symmetrical and full cells with about 250 μm- thick electrolytes were fabricated and electrochemically characterized using impedance spectroscopy and galvanostatic studies. Maximum power density of 500 mW cm−2 in fuel cell mode and an injected current of 1 A cm−2 at 1.3 V in electrolysis mode, both measured at 900 °C, were obtained demonstrating the feasibility of 3D printing for the fabrication of high-performance electrolyte-supported SOC. This, together with excellent stability proved for more than 350 h of operation, opens a new scenario for using complex-shaped SOC in real applications
Single-step fully 3D printed and co-sintered solid oxide fuel cells
No full textThe application of additive manufacturing technologies for the fabrication of functional ceramics has exhibited extraordinary potential for revolutionizing conventional manufacturing routes of electrochemical energy generators. The incorporation of 3D printing into the production strategy of Solid Oxide Cells (SOCs) allows their geometrical complexity to be increased through the hierarchical design of the systems, while simultaneously optimizing the ceramic manufacturing process, minimizing the upfront investment, and augmenting the manufacturing efficiency owing to the reduction in production steps. In this regard, the elaboration of multi-material 3D printing for the fabrication of entire SOC devices is required to achieve a fully automated production process. The current work presents and discusses the main technological and material challenges for the development of self-supported Solid Oxide Fuel Cells (SOFCs) fabricated in a single step by using hybrid multi-material 3D printing. The results on the fabrication of complete self-supported SOFCs are here presented with special attention to the most critical steps: the hybridization of stereolithography and robocasting 3D printing technologies and the co-sintering of a multilayered ceramic device. The electrochemical characterization of the printed and co-sintered cells validates the innovative approach, reaching a remarkable maximum power density above 250 mW cm−2 at 950 °C. This result, together with the developed hybrid technology, represents a step forward for further digitalization of the functional ceramic device manufacturing, more specifically, the SOC manufacturing process, leading to the fabrication of fully 3D printed monolithic SOFC stacks
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
Electrophoretic deposition of MnCo2O4 coating on solid oxide cell interconnects manufactured through powder metallurgy
Full text linkDeveloping cost-effective and durable interconnects for solid oxide cells is crucial to overcome currently existing barriers for the commercialization of this promising energy technology. A systematic microstructural and electrical characterization of MnCo2O4 spinel coatings processed by electrophoretic deposition on SUS 445 ferritic stainless steel, manufactured through powder metallurgy, is here reviewed and discussed for application in high temperature solid oxide cells stacks. The work presents a successful com- bination of the powder metallurgy processing of metallic interconnects with the electrophoretic deposition as a fast and versatile approach to coat complex interconnect shapes. Therefore, this study assesses the effect of the sintering route of coated steel on the final microstructure. Remarkable results in terms of electrical properties are here presented for EPD coated sample reduced at 1000 °C and re-oxidised at 800 °C in static air, obtaining an area specific resistance degradation rate of 1.2 mΩ cm2/kh together with an effective limitation of Cr outward diffusion despite the prolonged exposure in relevant conditions. This novel approach opens the door for a new class of complex-shaped interconnects with enhanced performance and durability and excellent scalability at a low cost
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
- …
