1,720,958 research outputs found

    When microplastics meet electroanalysis: future analytical trends for an emerging threat

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    Microplastics are a major modern challenge that must be addressed to protect the environment, particularly the marine environment. Microplastics, defined as particles ≤5 mm, are ubiquitous in the environment. Their small size for a relatively large surface area, high persistence and easy distribution in water, soil and air require the development of new analytical methods to monitor their presence. At present, the availability of analytical techniques that are easy to use, automated, inexpensive and based on new approaches to improve detection remains an open challenge. This review aims to outline the evolution and novelties of classical and advanced methods, in particular the recently reported electroanalytical detectors, methods and devices. Among all the studies reviewed here, we highlight the great advantages of electroanalytical tools over spectroscopic and thermal analysis, especially for the rapid and accurate detection of microplastics in the sub-micron range. Finally, the challenges faced in the development of automated analytical methods are discussed, highlighting recent trends in artificial intelligence (AI) in microplastics analysis

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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

    Sustainability from the start: biochar-based conductive inks enable the streamlined fabrication of green electroanalytical devices

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    The design of low-cost and disposable printed electrodes (PEs) has garnered significant attention from the scientific community in recent years. It is crucial to achieve industrial scalability by addressing the cost of conductive inks and ensuring their environmentally friendly disposal. The utilization of biochar, a carbon-rich material derived from the pyrolysis of biomass waste, represents a promising and sustainable alternative to conventional carbon sources. In this study, peanut shell biochar produced with a low-cost pyrolytic kiln reactor was incorporated into conductive inks. As far as we know, biochar-based ink was used to fully fabricate stencil-printed electrodes for the first time. Three different chemical treatments were employed to activate the biochar and enhance its properties. XPS analysis and electrochemical characterization studies showed that organic solvents improved the characteristics of the biochar when compared to acid or alkaline activation treatments. As a proof of concept, the electrodes were used to detect paracetamol as a model analyte for emerging environmental contaminants. An analytical greenness metric (AGREE) was used to infer how environmentally friendly the analytical procedure is, yielding an overall score of 0.72, which indicates a high degree of environmental sustainability. This study underscores the importance of implementing simple strategies to obtain cost-effective PE, thereby promoting green analytical methods using recycled materials such as bio-waste-derived biochar. This approach may reduce dependence on non-environmentally friendly materials for sensor fabrication and contribute to addressing industrial waste recycling challenges

    Variations on the Author

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    “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

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    We 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

    A smartphone label-free and automated thermo-analytical method based on image analysis to detect microplastics

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    Microplastics (MPs) are in some ways the expected product of man-made plastics that are considered as a pollutant ubiquitous in the environment. This is particularly notorious in continental waters, along coastlines, and especially in the North Pacific Gyre, sometimes called the Pacific Garbage Patch. Even now, there is growing concern that MPs can harm wildlife, enter the food chain, and end up in the human body. Therefore, the development of new, simpler and easily automated analytical systems is needed to assess the extent of MPs contamination in the environment. In this work, we present a low-cost analytical method capable of identifying, counting, and sizing MPs and differentiating them from non-plastic particles in less than 5 min after performing image-based analysis during a heating ramp between 25 and 220 °C. Using a smartphone and its camera and a dedicated algorithm, semi-crystalline and amorphous MPs such as polyethylene, polypropylene and polystyrene were efficiently identified by determining whether they melt or change size. The method was tested on spiked soil and sand samples as well as on real samples with successful results. A large number of particles can be analyzed simultaneously using an algorithm that eliminates the need for manual operations. The method is presented to be used as the first necessary step to investigate the level of threat (if any) of this new ubiquitous presence

    Dispelling the Myths Behind First-author Citation Counts

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    We 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

    Author Index

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    koamabayili/VECTRON-author-checklist: VECTRON author checklist

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    We 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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