1,721,030 research outputs found
Biosorption of lead (II) on modified barks explained by the hard and soft acids and bases (HSAB) theory
No full textAstier, Cedric Chaleix, Vincent Faugeron, Celine Ropartz, David Krausz, Pierre Gloaguen, Vincent15NORTH CAROLINA STATE UNIV DEPT WOOD & PAPER SCI[Astier, Cedric; Chaleix, Vincent; Faugeron, Celine; Krausz, Pierre; Gloaguen, Vincent] Fac Sci & Tech, Lab Chim Subst Nat, EA1069, F-87060 Limoges, France. [Ropartz, David] INRA, Plate Forme BIBS, Biopolymeres Interact Assemblages UR1268, F-44300 Nantes, [email protected] audienceChemical modification of Douglas fir bark and its subsequent utilization in adsorption of Pb(II) from aqueous solutions was investigated. The polysaccharidic moiety of barks was functionalized by periodate oxidation and derivatized after reductive amination in the presence of aminated oligo-carrageenans. Pb(II) adsorption isotherms of derivatized barks were then determined and compared to the capabilities of crude barks using the Langmuir adsorption model in terms of affinity (b) and maximum binding capacity (q(max)). Compared to crude barks, the derivatization of barks by oligo-carrageenans resulted in significant enhancements of q(max) and b by up to x8 and x4, respectively. The results obtained from crude barks on chemically grafted carboxylic and sulfated barks are discussed and interpreted through the Hard and Soft Acids and Bases (HSAB) theory
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
Unraveling isomeric structures of oligosaccharides by VUVPD and VUVEPD experiments: Towards an unambiguous and complete sequencing of isomers
No full textStructural characterization of carbohydrates is of key importance to better understand the structure/property relationships of these molecules, as well as to tailor compounds with enhanced functionalities. Mass spectrometry, with its remarkable sensitivity, rapidity and high information content, is a forefront method for that purpose. However, classical tandem mass spectrometry based on low-energy collision-activated dissociation (LE-CAD) fails in many cases to achieve definitive structural assignments. In this work, we investigated Vacuum Ultra-violet (VUV) synchrotron radiation as activation process for tandem mass spectrometry in positive and negative ion mode. A very interesting setup is implemented on the DISCO beamline which couples the synchrotron radiation with an ion trap mass spectrometer and enables the tuning of the photons energy between 5 and 22 eV. This study is the first one reporting the use of photo-activated dissociation in the VUV for large oligosaccharides. The features of the fragmentation spectra are remarkable and bring straightforward and rich structural information. This led to the comprehensive identification of a large number of structures, including many isomers. This enabled to reach by far the most complete description of the products released from the enzymatic degradation of polysaccharides, bringing insights both on the structure of these polymers as well as on the enzyme specificity. In that context, we believe that the advances brought by VUV activation in tandem MS will meet a widespread interest in the field of structural chemistry of carbohydrates
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe 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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
- …
