1,720,959 research outputs found
DESIGN OF NEW PORPHYRIN/ FE-LOADED TIO2 COMPOSITES FOR THE EFFICIENT DEGRADATION OF 4-NITROPHENOL BY HETEROGENEOUS PHOTO FENTON PROCESSES
No full textEfficient removal of low-arsenic concentrations from drinking water by combined coagulation and adsorption processes
No full textCombined separation and purification processes are gaining considerable attention in the water engineering community as they have the potential to integrate several treatment stages in a single, space-efficient and multifunctional process able to act as a multi-barrier against a wide spectrum of recalcitrant pollutants. In this paper, the efficiency of a combined physico-chemical process, previously validated as a tertiary treatment for municipal wastewater reclamation and successfully tested at pilot scale for the removal of total phenols, chemical oxygen demand (COD) and Escherichia coli, was tested for the precipitation of low-arsenic (V) concentration (<100 μg/L) from drinking water.
The combined process, consisting of simultaneously dosing, in various proportions and according to a Latin square design-of-experiment scheme, aluminum polychloride (AP), zeolite (Z), powder activated carbon (PAC) and sodium hypochlorite (SH) into dechlorinated tap water spiked with arsenic (V), was assessed at laboratory scale in order to elucidate the mechanism of arsenic (V) removal as well as to identify the optimal mixing conditions using variable-speed jar-test experiments.
Results indicated that the combined process was very effective in removing low arsenic (V) concentration from drinking water in the range of 25–100 μg/L. Moreover, it was found that, among the tested variables, high-velocity gradient conditions led to an improved removal efficiency which reached 89% under optimized process conditions. Although all treating agents played a statistically significant role in terms of process performance, arsenic (V) co-precipitation by AP was found to be the dominating removal mechanism contributing up to an 85% at 1400 rpm, with Z and PAC co-operating for the remaining 5% and mostly functioning as enhancing agents for ballasted settling. Notably, the process investigated in this study was also found to be robust against variation in initial arsenic concentration, showing similar arsenic (V) removal efficiency (85.9%) when the initial arsenic (V) concentration was further reduced from 100 to 25 μg/L. In conclusion, it was demonstrated that the combined treatment process was able to efficiently and simultaneously remove not only organic micropollutants such as phenols, COD and E. coli (as demonstrated in previous studies) but also inorganic contamination by arsenic (V) from a typical drinking water matrix via co-precipitation on aluminum polychloride, a treating agent that is worldwide accessible and typically used in water treatment applications
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
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
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