1,720,967 research outputs found
Re-thinking organic synthesis: Mechanochemistry as a greener approach
No full textThe increasing advances in mechanochemistry have opened new possibilities to develop organic processes in a more sustainable way. In this contribution, recent progress in this area has been described, going from laboratory scale protocols to industrial applications. Moreover, innovations in mechanochemical procedures and in-situ characterization analyses have been also discussed. Envisioning scale-up applications, several technologies such as twin-screw extrusion and high-throughput reaction platforms, able to combine continuous-flow mechanochemical and thermal conditions, have been investigated and developed. It is worth remarking that mechanochemistry is a highly promising approach with a lot of potentialities still to be unraveled
Graphene quantum dots by eco-friendly green synthesis for electrochemical sensing: Recent advances and future perspectives
No full textThe continuous decrease in the availability of fossil resources, along with an evident energy crisis, and the growing environmental impact due to their use, has pushed scientific research towards the development of innovative strategies and green routes for the use of renewable resources, not only in the field of energy production but also for the production of novel advanced materials and platform molecules for the modern chemical industry. A new class of promising carbon nanomaterials, especially graphene quantum dots (GQDs), due to their exceptional chemical-physical features, have been studied in many applications, such as biosensors, solar cells, electrochemical devices, optical sensors, and rechargeable batteries. Therefore, this review focuses on recent results in GQDs synthesis by green, easy, and low-cost synthetic processes from eco-friendly raw materials and biomass-waste. Significant advances in recent years on promising recent applications in the field of electrochemical sensors, have also been discussed. Finally, challenges and future perspectives with possible research directions in the topic are briefly summarized
Sustainable Carbon Dots from Cellulose Precursors for Environmental Sensing: Recent Trends and Outlook
No full textCarbon dots (CDs) have emerged as promising nanomaterials for optical sensing due to their outstanding photoluminescence, chemical stability, and biocompatibility. In recent years, the development of sustainable CDs derived from biomass—particularly cellulose—has attracted increasing interest as a green alternative to conventional synthetic routes. This review offers a comprehensive overview of recent advances in synthesis, functionalization, and application of cellulose-based carbon dots for environmental sensing. We examine key synthetic approaches—including hydrothermal, microwave-assisted, and pyrolytic methods—and discuss how the structure and origin of cellulose influence the physicochemical properties of the resulting CDs. The mechanisms underlying their sensing performance are analyzed in detail, with a focus on the detection of heavy metals, organic pollutants, and other environmental contaminants. Challenges related to reproducibility, scalability, and long-term stability are critically addressed. Finally, we outline future directions involving hybrid nanomaterials, real-time sensing platforms, and strategies aligned with circular economy principles. This review aims to serve as a valuable resource for researchers in the fields of sustainable nanomaterials, green chemistry, and environmental sensor development
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
Sustainable production of pharmaceutical, nutraceutical and bioactive compounds from biomass and waste
Full text linkThe aim of this tutorial review is to provide a general overview of processes, technologies and challenges in the production of pharmaceutical and bioactive compounds from food waste and lignocellulosic residues. Particular attention is given to benign-by-design processes instinctively devoted to environmental sustainability for the recovery of bioactive compounds from food waste as well as for the production of alcohols, acids, polyols, furans and aromatic compounds from lignocellulosic residues. At the same time, novel green synthetic routes for the production of active pharmaceutical ingredients and the development of novel bioactive compounds are discussed. Recent success industrial stories on the use of food waste and lignocellulosic residues for pharmaceutical and nutraceutical applications are also discussed. This journal i
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