1,720,965 research outputs found
Removal of imidacloprid pesticide using nanoporous activated carbons produced via pyrolysis of peach stone agricultural wastes
No full textEco-friendly Biopolymer/Activated Charcoal Magnetic Nanocomposites with Enhanced Stability and Adsorption Properties for Water Treatment Applications
No full textFabrication of 3D lignosulfonate composited sponges impregnated by BiVO4/polyaniline/Ag ternary photocatalyst for synergistic adsorption-photodegradation of fluoroquinolones in water
No full textIn this work, a 3D lignosulfonate composited poly(vinyl formal) (PVF) sponge impregnated by BiVO4/polyaniline (PANI)/Ag ternary photocatalyst (PLS-BiVO4/PANI/Ag) was designed and fabricated. The synergistic adsorption-photodegradation of five fluoroquinolones (FQs) antibiotics onto PLS-BiVO4/PANI/Ag was investigated. Incorporating lignosulfonate as a carrier on PVF sponge improved its structural properties and enhanced its adsorption performance toward FQs. The BiVO4/PANI/Ag ternary photocatalyst was well-dispersed and tightly bound to the composited sponge, thus it efficiently degraded the adsorbed FQs through surface photodegradation. PLS-BiVO4/PANI/Ag achieved \u3e90% removal efficiency for all examined FQs within 2.0 h in a batch system, while it maintained a steady 80% removal efficiency for 30.0 h in a continuous dynamic treatment system. Photoelectric characterizations and ESR results showed that BiVO4/PANI/Ag was consistent with the type II heterostructure and effectively improved the utilization of visible light and the separation of photogenerated electron-hole pairs. The hole was the dominant active species in the degradation of FQs, while the main degradation pathways included defluorination, decarboxylation and destruction of piperazine ring. The prepared composited sponge is thus characterized by its high performance, convenient operation, eco-friendliness, and practicality in real water treatment systems since it undergoes self-purification and is easily recovered from water without mass loss
Efficient adsorption of chloroquine phosphate by a novel sodium alginate/tannic acid double-network hydrogel in a wide pH range
No full textRemoval of copper (II) ions by eco-friendly raw eggshells and nano-sized eggshells: a comparative study
No full textThis work evaluates the potential of using eggshells as biosorbents for the removal of copper (II) ions from aqueous solutions. Two types of eggshells were investigated; untreated raw eggshells (ES) and eggshells that were mechanically ball-milled into the nano-size (NES). TEM imaging confirmed the nano-size of NES which lies in the range of 12–14.8 nm, while BET analysis showed that both types of eggshells are mesoporous and that the surface area of NES is 1.6 times higher than its ES counterpart. FTIR spectra, XRD patterns, and SEM-EDX measurements indicated that there are no structural differences between ES and NES. Optimum adsorption took place at pH 5 and initial Cu (II) concentration of 20 mg/L for both ES and NES where removal efficiencies of 91.36% and 97.21% were achieved, respectively. Although both biosorbents exhibited comparable adsorption capacities, yet the rate of adsorption of Cu (II) onto NES was 17 times higher than its counterpart onto ES probably due to the larger surface area of NES. It could be hypothesized that the mechanism of interaction took place via electrostatic outer-sphere complexation between the positively-charged Cu ions and the negatively-charged ES or NES as zeta potential measurements indicated. Additionally, ES and NES were regenerated for four cycles. From this study, it can thus be deduced that both ES and NES could be potentially utilized as eco-friendly adsorbents for the removal of copper ions from contaminated water. However, NES provides an additional advantage over ES since it offers much rapid removal of Cu (II) while possessing the same adsorption capacity of ES
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
Novel approach for effective removal of methylene blue dye from water using fava bean peel waste
No full text© 2020, The Author(s). Fava bean peels, Vicia faba (FBP) are investigated as biosorbents for the removal of Methylene Blue (MB) dye from aqueous solutions through a novel and efficient sorption process utilizing ultrasonic-assisted (US) shaking. Ultrasonication remarkably enhanced sorption rate relative to conventional (CV) shaking, while maintaining the same sorption capacity. Ultrasonic sorption rate amounted to four times higher than its conventional counterpart at 3.6 mg/L initial dye concentration, 5 g/L adsorbent dose, and pH 5.8. Under the same adsorbent dose and pH conditions, percent removal ranged between 70–80% at the low dye concentration range (3.6–25 mg/L) and reached about 90% at 50 mg/L of the initial dye concentration. According to the Langmuir model, maximum sorption capacity was estimated to be 140 mg/g. A multiple linear regression statistical model revealed that adsorption was significantly affected by initial concentration, adsorbent dose and time. FBP could be successfully utilized as a low-cost biosorbent for the removal of MB from wastewater via US biosorption as an alternative to CV sorption. US biosorption yields the same sorption capacities as CV biosorption, but with significant reduction in operational times
- …
