1,721,046 research outputs found
Advancements in tailoring PEDOT: PSS properties for bioelectronic applications: A comprehensive review
Full text linkIn the field of bioelectronics, the demand for biocompatible, stable, and electroactive materials for functional biological interfaces, sensors, and stimulators, is drastically increasing. Conductive polymers (CPs) are synthetic materials, which are gaining increasing interest mainly due to their outstanding electrical, chemical, mechanical, and optical properties. Since its discovery in the late 1980s, the CP Poly(3,4-ethylenedioxythiophene):poly (styrene sulfonic acid) (PEDOT:PSS) has become extremely attractive, being considered as one of the most capable organic electrode materials for several bioelectronic applications in the field of tissue engineering and regenerative medicine. Main examples refer to thin, flexible films, electrodes, hydrogels, scaffolds, and biosensors. Within this context, the authors contend that PEDOT:PSS properties should be customized to encompass: i) biocompatibility, ii) conductivity, iii) stability in wet environment, iv) adhesion to the substrate, and, when necessary, v) (bio-)degradability. However, consolidating all these properties into a single functional solution is not always straightforward. Therefore, the objective of this review paper is to present various methods for acquiring and improving PEDOT:PSS properties, with the primary focus on ensuring its biocompatibility, and simultaneously addressing the other functional features. The last section highlights a collection of designated studies, with a particular emphasis on PEDOT:PSS/carbon filler composites due to their exceptional characteristics
Material extrusion additive manufacturing of zirconia: from filament characterisation to Weibull statistics
Full text linkPurpose: This study aims to investigate the performance of filament-based material extrusion additive manufacturing (MEX), combined with debinding and sintering, as a novel approach to manufacturing ceramic components. Design/methodology/approach: A commercial ZrO2 filament was selected and analysed by infra-red (IR) spectroscopy, rheology and thermo-gravimetry. The influence of the print parameters (layer thickness, flow rate multiplier, printing speed) and sintering cycle were investigated to define a suitable printing and sintering strategy. Biaxial flexure tests were applied on sintered discs realised with optimised printing strategies, and the results were analysed via Weibull statistics to evaluate the mechanical properties of printed components. The hardness and thermal conductivity of sintered components were also tested. Findings: Layer thickness and flow rate multiplier of the printing process were proved to have significant effect on the density of as-printed parts. Optimised samples display a sintered density >99% of the theoretical density, 20% linear sintering shrinkage, a characteristic flexural strength of 871 MPa with a Weibull modulus of 4.9, a Vickers hardness of 12.90 ± 0.3 GPa and a thermal conductivity of 3.62 W/mK. Gyroids were printed for demonstration purposes. Originality/value: To the best of the authors’ knowledge, this work is the first to apply biaxial flexure tests and Weibull statistics to additively manufactured MEX zirconia components, hence providing comparable results to other additive technologies. Moreover, fractography analysis builds the connection between printing defects and the fracture mechanism of bending. This study also provides guidelines for fabricating high-density zirconia components with MEX
Design and Development of a RFID Assisted Flexible Printed Temperature Threshold Indicator
No full textVaccines and cold food supply chains induce loss, costing millions of Euros due to heat exposure in logistics. Therefore, this study aims to create a smart, green, biodegradable temperature indicator label for smart packaging to indicate heat exposure. First, conductive (silver) interconnects and HF RFID antenna are printed using Aerosol Jet Printing (AJP) on fibre-based substrates. Next, a self-formulated polyaniline ink (non-conducting) is deposited with AJP. Using a temperature-dependent mechanism, an acid is used as a stimulus, which subsequently transforms the non-conducting polyaniline ink into conductive ink (visualised by turning the blue color of the ink into green). Finally, this reaction can be read out with an RFID reader. This proof of concept could in the future be laminated and tested as a TTI label on a card box for smart (e)-packaging
Design and Development of a RFID Assisted Flexible Printed Temperature Threshold Indicator
No full textVaccines and cold food supply chains induce loss, costing millions of Euros due to heat exposure in logistics. Therefore, this study aims to create a smart, green, biodegradable temperature indicator label for smart packaging to indicate heat exposure. First, conductive (silver) interconnects and HF RFID antenna are printed using Aerosol Jet Printing (AJP) on fibre-based substrates. Next, a self-formulated polyaniline ink (non-conducting) is deposited with AJP. Using a temperature-dependent mechanism, an acid is used as a stimulus, which subsequently transforms the non-conducting polyaniline ink into conductive ink (visualised by turning the blue color of the ink into green). Finally, this reaction can be read out with an RFID reader. This proof of concept could in the future be laminated and tested as a TTI label on a card box for smart (e)-packaging
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
Material Extrusion-Debinding-Sintering as an Emerging Additive Manufacturing Process Chain for Metal/Ceramic Parts Construction
No full textMaterial Extrusion of metal/ceramic-polymer filaments for the construction of, respectively, metal or ceramic parts, has raised great interest among the research community during the last five years. It usually comprises three main phases: printing, debinding and sintering. With respect to other metal/ceramic Additive Manufacturing (AM) technologies, the benefits are several: simplicity, enhanced safety during use, material and costs saving. The present essay aims to provide a comprehensive overview of the main advances and criticalities influencing the spreading and potential applications of this promising AM research field. More in detail, the following issues are addressed: (i) description of the specific technologies comprised within the metal/ceramic Material Extrusion process chain, (ii) processed materials, (iii) material properties (iv) shrinkage evaluation, (v) post-processing treatments, and (vi) geometric limitations
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
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