1,720,967 research outputs found
Ionic Liquids Can Significantly Improve Textile Dyeing: An Innovative Application Assuring Economic and Environmental Benefits
No full textOwing to economic reasons, the textile dyeing industry generally employs traditional and absolutely no-eco-friendly processes: very large quantities of water are indeed required together with a large number of added chemicals which represent dramatic environmental issues. In order to improve the sustainability of the process, we have investigated the dyeing of wool, polyester, and cotton with disperse Red 13 using ionic liquids as the sole additive. The results obtained in isothermal dyeing at 95 C show an outstanding effect of the ionic liquid 1-(2-hydroxyethyl)-3-methylimidazolium chloride. This ionic liquid assures efficient dyeing of polyester and wool in open vessels, in the absence of whichever auxiliary agent with total dyebath exhaustion, thus allowing in principle the recycling of the dye bath! The environmental benefits arising from the substitution of a number of usually employed auxiliary agents with only an ionic liquid are highlighted together with the economic ones. This article reports for the first time, to the best of our knowledge, dyeing processes for several kinds of fibers (cotton, wool, and polyester) employing exclusively three components: pure disperse dye, water, and an appropriate ionic liquid. (Figure Presented)
Redox Driven Intramolecular Anion Translocation Between a Metal Centre and a H bond Donating Compartment
No full textAbstract: Dicationic ligands incorporating
two 2,2’-bipyridine units and two
imidazolium moieties, [1]2+ and [2]2+,
form stable chelate complexes with
CuII and CuI in acetonitrile solution.
Each CuII complex binds two X ions
according to two stepwise equilibria,
the first involving the CuII centre and
the second involving the bis-imidazolium
compartment. CuI complexes are
able to host only one NO3 ion in the
bis-imidazolium cavity, while other
anions induce demetallation. Thus, in
the presence of one equivalent of
NO3, the CuII/CuI redox change
makes the anion translocate quickly
and reversibly from one binding site to
the other within the [CuII,I(1)]4+/3+
system, as demonstrated by cyclic voltammetry
and controlled-potential
electrolysis experiments
From pollen grains to functionalized microcapsules: a facile chemical route using ionic liquids
No full textPhysiological and biochemical impacts of graphene oxide in polychaetes: the case of Diopatra neapolitana
Get PDFGraphene Oxide (GO) is an important carbon Nanomaterial (NM) that has been used, although limited literature is available regarding the impacts induced in aquatic organisms by this pollutant and, in particular in invertebrate species. The polychaete Diopatra neapolitana has frequently been used to evaluate the effects of environmental disturbances in estuarine systems due to its ecological and socio-economic importance but to our knowledge no information is available on D. neapolitana physiological and biochemical alterations due to GO exposure. Thus, the present study aimed to assess the toxic effects of different concentrations of GO (0.01; 0.10 and 1.00mg/L) in D. neapolitana physiological (regenerative capacity) and biochemical (energy reserves, metabolic activity and oxidative stress related biomarkers) performance, after 28days of exposure. The results obtained revealed that the exposure to GO induced negative effects on the regenerative capacity of D. neapolitana, with organisms exposed to higher concentrations taking longer periods to completely regenerate and less regenerated segments. GO also seemed to alter energy-related responses, especially glycogen content, with higher values in polychaetes exposed to GO which may result from a decreased metabolism (measured by electron transport system activity), when exposed to GO. Furthermore, under GO contamination D. neapolitana presented cellular damage, despite higher activities of antioxidant and biotransformation enzymes in individuals exposed to GO
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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