1,720,983 research outputs found
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
Microwave-Assisted Protocol for Green Functionalization of Thiophenes With a Pd/β-Cyclodextrin Cross-Linked Nanocatalyst
Get PDFMicrowaves (MW) are often the most efficient, in terms of heat exchange and conversion rate, of all the energy sources used to promote chemical reactions thanks to fast volumetric dielectric heating, and metal-catalyzed synthetic reactions under heterogeneous conditions are an eloquent example. We herein report a MW-assisted green protocol for the C-H arylation of thiophenes with substituted aryl halides. This sustainable protocol carried out in γ-valerolactone (GVL) is catalyzed by Pd nanoparticles embedded in cross-linked β-cyclodextrin. In view of the excellent results achieved with activated substrates, the one-pot synthesis of a 4(3H)-quinazolinone derivative has been accomplished. A pressure-resistant MW reactor, equipped with multiple gas inlets, was used for sequential (i) C-H arylation, (ii) reduction, and (iii) carbonylation in the presence of the same catalyst, but under different gas atmospheres. The robust heterogeneous Pd catalyst showed limited metal leaching in GVL, making this an efficient MW-assisted process with high atom economy
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
From seaweeds to cosmeceutics: A multidisciplinar approach
Get PDFMacroalgae are widespread on the coasts of all the globe and lead to a negative ecological impact, requiring expensive remediations. Therefore, the valorization of invasive seaweed as a renewable source of bioactive products could represent a valid solution. In this context, three algal biomasses, belonging to brown, green, and red families (Sargassum muticum, Ulva lactuca, Solieria filiformis), collected in the venetian Laguna, were investigated as a source of active compounds for the formulation of cosmeceutics. Microwave (MW) and ultrasound (US) were applied to enhance the algae extraction by means of a hydroalcoholic solution. According to total phenolic content (TPC) evaluation, MW demonstrated the best performing outcomes, resulting in 19.77, 22.02, and 16.94 mgGAE/gExtr (30 min at 90◦C) for brown, green, and red algae, respectively. Antioxidant activity was tested as well, showing comparable trends (49.19, 26.24, and 3.02 mmolTrolox eq./gExtr for brown, green, and red algae, respectively). Due to natural algae predisposition to absorb contaminants, the metal content analysis helped to screen the applicability of these extracts, identifying Ulva lactuca as the most suitable source of antioxidants for cosmetic formulations. This MW extract was then adopted to formulate two different preparations, namely a gel and an emulsion. Thermal and mechanical tests confirmed the stability of each formulation, together with neutral organoleptic characteristics. Finally, the actives release was investigated by means of a tape stripping essay, showing an efficient controlled release for gel formulation, even after 7 h of test. The produced cosmeceutics merged non-conventional extraction technologies with formulation expertise, offering a valuable alternative to solve the macroalgae disposal issue
A smart use of biomass derivatives to template an: Ad hoc hierarchical SAPO-5 acid catalyst
No full textA smart design of hierarchical SAPO-5 acid catalyst using biomass derived monosaccharides as sustainable and low-cost mesoporogens has been developed. The hierarchical SAPO-5 was characterized by several physico-chemical techniques to elucidate structure-properties relationships and was tested as a catalyst in the MW-assisted glucose transformation in 5-HMF using γ-valerolactone (GVL) as green solvent. This journal i
Non-Phenolic Dicinnamamides from Pholiota spumosa: Isolation, Synthesis and Anti-Tumour Activity
No full textDispelling 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
Integrated biochemical and chemical processing of municipal bio-waste to obtain bio based products for multiple uses. The case of soil remediation
No full textIn line with the Green Supply Chain Management, Sustainable Supply Chain Management and Natural-Resource-Based Views (NRBV), the present study is as further step of a long range research program initiated in 2004. The project aims to demonstrate municipal bio-waste (MBW) as feedstock to produce bio based chemicals alternative to fossil sourced products. Previous work demonstrated MBW as source of polymeric biosurfactants (BPS) with multiple properties for use in chemical and agriculture sectors. The present paper reports now a new BPS feature, i.e. that BPS are efficient active principles for soil remediation. The study involves three BPS obtained by alkaline hydrolysis from different streams of an MBW treatment plant: the anaerobic digestate of food kitchen waste (FORSUD), the compost (CV) of gardening residues and the compost (CVDF) of a mix of gardening residues, digestate and sewage sludge. The BPS have 5 to over 750 kg/mol molecular weight, characterized by the presence of aliphatic C chains substituted by aromatic moieties and several different acid and basic functional groups. They were used at 0.1–100 g L−1 in aqueous solution to wash soil sampled from an Italian metal polluted site. Collected data statistical analysis was carried out by ANOVA. The recovered washing solutions were analyzed for Cu, Cr, Ni, Zn, Pb. The 50–100 g/L CVDF BPS solutions exhibited 98-81% extraction efficiency, compared to 70-60% for CV and FORSUD. Compared to conventional commercial extractants, CVDF BPS extraction efficiency ranked as CVDF = diethylene triamine pentaacetic acid > ethylene diamine tetraacetic acid > sodium dodecyl sulphate. A new two steps process was studied: (1) use of BPS solution for washing the polluted soil; (2) treating the recovered solution by acidification and membrane filtration to separate a pollutant concentrate from water for further use. Results indicate membrane filtration more efficient and/or sustainable. They confirm BPS as value added products upgrading MBW from societal cost to source of benefits
- …
