1,721,019 research outputs found
Hybrid Inorganic‐Organic White Light Emitting Diodes
No full textThis chapter reviews the state of the art of materials, technologies, characterizations, process and challenges concerning hybrid white light‐emitting diodes (LEDs). Here, for a “hybrid LED” we mean a device based on a layer of organic phosphors (or a mix of inorganic and organic ones) pumped by a high‐energy inorganic LED. Light is emitted by a frequency down‐conversion (sometimes simply named color‐conversion) process. Benefits and weak spots of this technology are investigated with a special attention for the materials involved into the process of frequency down‐conversion, in order to envisage the future impact of the hybrid lighting technology among the well‐established inorganic ones
State-Of-The-Art Overview of CO2 Conversions
No full textDue to the environmental problems about climate change and global warming, carbon dioxide is transformed and valorized from an emission to a raw material of many chemical production processes. This contributes transforming the linear economy into a circular one, considering the principles of reduction, reuse, recovery, recycle. However, the potential carbon dioxide uptake is lower compared to the worldwide CO2 emissions, estimated of 37 Gt actually. In the literature, many utilization options are suggested and are evaluated according to the 3E performance criteria (engineering–economic–environmental), including nine key indicators. An economic estimation and an analysis about the market size of the main carbon dioxide-based products are here suggested. Moreover, with particular attention, in this work, different routes for carbon dioxide utilization are reviewed: chemicals, fuels, concrete building materials, horticulture and microalgae production as well as mineral carbonation, oil and methane recovery and some direct uses. Cycling, closed and open pathways can be realized. Carbon dioxide utilization pathways ensuring a promising development in the next years are suggested
Green organic synthesis in supercritical water
No full textWater under supercritical conditions displays unique characteristics because of which it has emerged as an interesting solvent in recent years. It is abundantly available in nature and does not affect the environment, making it a green solvent. Owing to its low cost, nontoxic, and nonflammable nature, it has a great prospective in various green organic synthesis. However, due to its corrosive nature and extreme conditions, it is not utilized to its full potential. This chapter highlights some important commercial applications of supercritical water such as the conversion of lignocellulosic biomass to solid and liquid fuel, waste destruction, organic synthesis, and powder metallurgy
Role of dual dopants in highly ordered crystalline polyaniline nanospheres: Electrode materials in supercapacitors
No full textA Simple and Reusable Polyaniline Catalyst for the Ring-opening Polymerization of Tetrahydrofuran
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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
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
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