1,720,956 research outputs found
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
Ammonium removal and recovery from municipal wastewater by ion exchange using a metakaolin K-based geopolymer
Full text linkAmong the available technologies for ammonium removal from wastewater, ion exchange represents one of the most promising ones in the perspective to recover ammonium and produce a fertilizing product. However, the vast majority of previous studies on ammonium ion exchange did not evaluate the process robustness under real operational conditions nor optimized the desorption step. In this paper, tests of ammonium removal and recovery were conducted on a metakaolin K-based geopolymer, compared with a high-performing Italian natural zeolite in K-form. Real municipal and saline wastewater was treated in a continuous flow pilot plant equipped with a 60-cm adsorption bed (bed volume 203 mL, sorbent mass 145-173 g, empty bed contact time 10 min). Geopolymer granules showed higher performances in terms of selectivity towards ammonium, operating capacity (8.5 mgN g-1 dry adsorbent at an inlet concentration of 40 mgN L-1), bed volumes of wastewater treated at the selected breakpoint (149). Geopolymer resulted to be a cost-effective adsorbent for wastewater treatment capable to adsorb cations by ion exchange, allowing a fractionated desorption procedure that led to recover ammonium in a solution composed mainly by NH4NO3 (37%wt) and KNO3 (56%wt), potentially usable as fertilizer. The geopolymer robustness was assessed after repeated adsorption/regeneration cycles showing that the geopolymer mechanical and morphological properties did not deteriorate. The results make the tested geopolymer a very promising material for the optimization and scale-up of the ammonium recovery process in a circular economy perspective
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
Development and validation of an adsorption process for phosphate removal and recovery from municipal wastewater based on hydrotalcite-related materials
Full text linkIn the current international context characterized by the tendency to stricter limits for P concentration in treated wastewater and a strong drive towards phosphate recovery, it is crucial to develop cost-effective technologies to remove and recover phosphate from municipal wastewater (MWW). In this study, an initial screening of the phosphate adsorption performances of 9 sorbents including several hydrotalcites led to the selection of calcined pyroaurite - an innovative material composed of mixed Mg/Fe oxides - as the best-performing one. The assessment of calcined pyroaurite by means of isotherms and continuous-flow adsorption/desorption tests conducted with actual MWW resulted in a high P sorption capacity (12 mgP g- 1 at the typical phosphate concentration in MWW), the capacity to treat 730 BVs at the 1 mgP L- 1 breakpoint imposed by the current EU legislation, and a 93 % phosphate recovery. Calcined pyroaurite resulted in satisfactory performances also in a test conducted with a saline MWW deriving from a hotspot of seawater intrusion, a rapidly increasing phenomenon as a result of climate change. Five consecutive adsorption/desorption cycles conducted in a 20-cm column at a 5-min empty bed contact time resulted stable in terms of P adsorption/recovery performances, specific surface area and chemical structure of calcined pyroaurite. In the perspective to apply phosphate recovery with calcined pyroaurite at full scale, the process scale-up to a 60-cm packed bed - close to the column heights of industrial applications- resulted in stable performances. Calcium phosphate, widely used to produce phosphate-based fertilizers, can be obtained from the desorbed product by precipitation with Ca(OH)2. 2 . These results point to calcined pyroaurite as a very promising material for phosphate removal and recovery from MWW and from other P-rich effluents in a circular economy perspective
Ammonium recovery from municipal wastewater by ion exchange: Development and application of a procedure for sorbent selection
No full textIon exchange represents one of the most promising processes for ammonium recovery from municipal waste-water (MWW). However, most previous studies on ammonium ion exchange did not optimize the process or evaluate its robustness under real operational conditions. This experimental study aimed at (i) developing a procedure for the selection of a sorbent for selective ammonium removal/recovery from MWW, (ii) validating the procedure by applying it to several sorbents, (iii) performing a preliminary optimization and robustness assessment of ammonium removal/recovery with the selected sorbent. The application of the procedure to natural and synthetic zeolites and a cation exchange resin confirmed that batch isotherm tests need to be integrated by continuous-flow tests. The selected sorbent, a natural mixture of Chabazite and Phillipsite, resulted in high performances in terms of cation exchange capacity (33 mgN gd(ry resin)(-1)), ammonium operating capacity (5.2 mgN g(dry resin)(-1)), ammonium recovery yield (78-91%) and selectivity towards ammonium. The process performances resulted stable during 7 adsorption/desorption cycles conducted with MWW treatment plant effluents in a 60-cm column. The switch to a highly saline effluent produced in a hotspot of seawater intrusion did not determine significant changes in performances. Contact time was reduced to 6 min without any decrease in performances. Potassium - well tolerated by crops - was selected as the regenerating agent, in the perspective to produce a desorbed product to be re-used as fertilizer. The study shows that Chabazite/Phillipsite has a high capacity to recover ammonium from MWW in a circular economy approach
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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