1,720,964 research outputs found
Phosphate and ammonium removal from wastewaters using natural-based innovative bentonites impacting on resource recovery and circular economy
No full textThe research objective of the study is the estimation of a novel low-cost composite material f-MB (Fe-modified bentonite) as a P and N adsorbent from wastewaters. The present study aimed at examining the phosphate and ammonium removal efficiency from different types of wastewater using f-MB, by conducting bench-scale batch experiments to investigate its equilibrium characteristics and kinetics. The SEM analysis revealed that the platelets of bentonite in f-MB do not form normal bentonite sheets, but they have been restructured in a more compact formation with a great porosity. Regarding the sorption efficiencies (Qm), the maximum phosphate sorption efficiencies (Qm) calculated using the Langmuir model were 24.54, 25.09, 26.13, 24.28, and 23.21 mg/g, respectively, for a pH range of 5 to 9. In addition, the maximum NH4+-N adsorption capacities (Qm) calculated from the Langmuir model were 131.8, 145.7, 168.5, 156.7, and 159.6 mg/g, respectively, for a pH range from 5 to 9. Another important finding of this study is that f-MB can recover P from treated wastewater impacting on resource recovery and circular economy (CE). The modified clay f-MB performed the phosphate and ammonium recovery rates of 80% and 78.5%, respectively. Finally, f-MB can slowly release the largest proportion of phosphate and ammonium ions for a long time, thus extending the application of the f-MB material as a slow-release fertilizer and soil improver
Application of novel composite materials as sediment capping agents: Column experiments and modelling
No full textThe research objective of the study is the estimation of PhoslockTM as a P&N-inactivation agent in the overlying water and sediment cores under oxic and anoxic conditions from a polluted pond. PhoslockTM was compared with ferrihydrite, unmodified bentonite (N-Bentonite), natural Zeolite (N-Zeolite), Alum and commercial Z2G1TM. Under oxic conditions, the maximum sorption capacities (qm) calculated from the Langmuir model were 14.1, 12.4, 11.2, 9.1 and 3.7 mg g–1 for ferrihydrite, PhoslockTM, alum, Z2G1, and natural bentonite, respectively. However, under anoxic conditions the maximum sorption capacities followed the order: PhoslockTM > alum > Z2G1>ferrihydrite > N-bent onite. Moreover, PhoslockTM as a P-inactivation agent resulted in about ~81% and ~82% reduction of the phosphate flux from oxic and anoxic sediments respectively. Also, the effect of dissolved organic matter (DOM) on phosphate sorption capacity (PAC) of PhoslockTM and Z2G1 was studied experimentally and theoretically, simulating natural eutrophic waters. At both P-sorption agents by increasing the concentration of DOM, the sorption capacity is declined. However, it is noteworthy that in the case of PhoslockTM application the PAC is retarded, whereas in the case of Z2G1 is sharp. Furthermore, the results unveiled that PhoslockTM restrained P release from the sediments, therefore a portion of P-mobile is reduced in sediments and undergone transformation to non-reactive species. Finally, in economic terms the research outcomes of this study were verified by literature, where we reported that the concentration of 20.53 mg mobile P kg–1 can be feasibly treated for $30.53 kg–1 of PhoslockTM applied
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
Novel composite materials as P-adsorption agents and their potential application as fertilizers
No full textThe main objective of this study is to review the role of phosphorus in fertilizers, emphasizing in phosphate rock which is the primary source for phosphate fertilizer, with reference to harmful heavy metals as a consequence of their use. Simultaneously, this study examined the use of P-Adsorption agents as a potential application in agriculture, as the adsorbed phosphorus can be used as fertilizer or enriching soil conditioners. Therefore, it is generated a sustainable cycle taking into account a renewable resource-based Phosphorus Adsorption Agent (P-AA) leading to environmental protection and conservation of natural resources. Finally, this study highlighted new aspects that support P bioavailability of Humic-metal-P (HMP) in soils, correlating with novel materials in water purification
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